1/* -*- Mode: C; tab-width: 4 -*-
2 *
3 * Copyright (c) 2002-2018 Apple Inc. All rights reserved.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 *     http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16
17   NOTE:
18   If you're building an application that uses DNS Service Discovery
19   this is probably NOT the header file you're looking for.
20   In most cases you will want to use /usr/include/dns_sd.h instead.
21
22   This header file defines the lowest level raw interface to mDNSCore,
23   which is appropriate *only* on tiny embedded systems where everything
24   runs in a single address space and memory is extremely constrained.
25   All the APIs here are malloc-free, which means that the caller is
26   responsible for passing in a pointer to the relevant storage that
27   will be used in the execution of that call, and (when called with
28   correct parameters) all the calls are guaranteed to succeed. There
29   is never a case where a call can suffer intermittent failures because
30   the implementation calls malloc() and sometimes malloc() returns NULL
31   because memory is so limited that no more is available.
32   This is primarily for devices that need to have precisely known fixed
33   memory requirements, with absolutely no uncertainty or run-time variation,
34   but that certainty comes at a cost of more difficult programming.
35
36   For applications running on general-purpose desktop operating systems
37   (Mac OS, Linux, Solaris, Windows, etc.) the API you should use is
38   /usr/include/dns_sd.h, which defines the API by which multiple
39   independent client processes communicate their DNS Service Discovery
40   requests to a single "mdnsd" daemon running in the background.
41
42   Even on platforms that don't run multiple independent processes in
43   multiple independent address spaces, you can still use the preferred
44   dns_sd.h APIs by linking in "dnssd_clientshim.c", which implements
45   the standard "dns_sd.h" API calls, allocates any required storage
46   using malloc(), and then calls through to the low-level malloc-free
47   mDNSCore routines defined here. This has the benefit that even though
48   you're running on a small embedded system with a single address space,
49   you can still use the exact same client C code as you'd use on a
50   general-purpose desktop system.
51
52 */
53
54#ifndef __mDNSEmbeddedAPI_h
55#define __mDNSEmbeddedAPI_h
56
57#if defined(EFI32) || defined(EFI64) || defined(EFIX64)
58// EFI doesn't have stdarg.h unless it's building with GCC.
59#include "Tiano.h"
60#if !defined(__GNUC__)
61#define va_list         VA_LIST
62#define va_start(a, b)  VA_START(a, b)
63#define va_end(a)       VA_END(a)
64#define va_arg(a, b)    VA_ARG(a, b)
65#endif
66#else
67#include <stdarg.h>     // stdarg.h is required for for va_list support for the mDNS_vsnprintf declaration
68#endif
69
70#include "mDNSDebug.h"
71#if APPLE_OSX_mDNSResponder
72#include <uuid/uuid.h>
73#include <TargetConditionals.h>
74#endif
75
76#ifdef __cplusplus
77extern "C" {
78#endif
79
80// ***************************************************************************
81// Feature removal compile options & limited resource targets
82
83// The following compile options are responsible for removing certain features from mDNSCore to reduce the
84// memory footprint for use in embedded systems with limited resources.
85
86// UNICAST_DISABLED - disables unicast DNS functionality, including Wide Area Bonjour
87// ANONYMOUS_DISABLED - disables anonymous functionality
88// DNSSEC_DISABLED - disables DNSSEC functionality
89// SPC_DISABLED - disables Bonjour Sleep Proxy client
90// IDLESLEEPCONTROL_DISABLED - disables sleep control for Bonjour Sleep Proxy clients
91
92// In order to disable the above features pass the option to your compiler, e.g. -D UNICAST_DISABLED
93
94// Additionally, the LIMITED_RESOURCES_TARGET compile option will reduce the maximum DNS message sizes.
95
96#ifdef LIMITED_RESOURCES_TARGET
97// Don't support jumbo frames
98// 40 (IPv6 header) + 8 (UDP header) + 12 (DNS message header) + 1440 (DNS message body) = 1500 total
99#define AbsoluteMaxDNSMessageData   1440
100// StandardAuthRDSize is 264 (256+8), which is large enough to hold a maximum-sized SRV record (6 + 256 bytes)
101#define MaximumRDSize               264
102#endif
103
104#if !defined(MDNSRESPONDER_BTMM_SUPPORT)
105#define MDNSRESPONDER_BTMM_SUPPORT 0
106#endif
107
108// ***************************************************************************
109// Function scope indicators
110
111// If you see "mDNSlocal" before a function name in a C file, it means the function is not callable outside this file
112#ifndef mDNSlocal
113#define mDNSlocal static
114#endif
115// If you see "mDNSexport" before a symbol in a C file, it means the symbol is exported for use by clients
116// For every "mDNSexport" in a C file, there needs to be a corresponding "extern" declaration in some header file
117// (When a C file #includes a header file, the "extern" declarations tell the compiler:
118// "This symbol exists -- but not necessarily in this C file.")
119#ifndef mDNSexport
120#define mDNSexport
121#endif
122
123// Explanation: These local/export markers are a little habit of mine for signaling the programmers' intentions.
124// When "mDNSlocal" is just a synonym for "static", and "mDNSexport" is a complete no-op, you could be
125// forgiven for asking what purpose they serve. The idea is that if you see "mDNSexport" in front of a
126// function definition it means the programmer intended it to be exported and callable from other files
127// in the project. If you see "mDNSlocal" in front of a function definition it means the programmer
128// intended it to be private to that file. If you see neither in front of a function definition it
129// means the programmer forgot (so you should work out which it is supposed to be, and fix it).
130// Using "mDNSlocal" instead of "static" makes it easier to do a textual searches for one or the other.
131// For example you can do a search for "static" to find if any functions declare any local variables as "static"
132// (generally a bad idea unless it's also "const", because static storage usually risks being non-thread-safe)
133// without the results being cluttered with hundreds of matches for functions declared static.
134// - Stuart Cheshire
135
136// ***************************************************************************
137// Structure packing macro
138
139// If we're not using GNUC, it's not fatal.
140// Most compilers naturally pack the on-the-wire structures correctly anyway, so a plain "struct" is usually fine.
141// In the event that structures are not packed correctly, mDNS_Init() will detect this and report an error, so the
142// developer will know what's wrong, and can investigate what needs to be done on that compiler to provide proper packing.
143#ifndef packedstruct
144 #if ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9)))
145  #define packedstruct struct __attribute__((__packed__))
146  #define packedunion  union  __attribute__((__packed__))
147 #else
148  #define packedstruct struct
149  #define packedunion  union
150 #endif
151#endif
152
153// ***************************************************************************
154#if 0
155#pragma mark - DNS Resource Record class and type constants
156#endif
157
158typedef enum                            // From RFC 1035
159{
160    kDNSClass_IN               = 1,     // Internet
161    kDNSClass_CS               = 2,     // CSNET
162    kDNSClass_CH               = 3,     // CHAOS
163    kDNSClass_HS               = 4,     // Hesiod
164    kDNSClass_NONE             = 254,   // Used in DNS UPDATE [RFC 2136]
165
166    kDNSClass_Mask             = 0x7FFF, // Multicast DNS uses the bottom 15 bits to identify the record class...
167    kDNSClass_UniqueRRSet      = 0x8000, // ... and the top bit indicates that all other cached records are now invalid
168
169    kDNSQClass_ANY             = 255,   // Not a DNS class, but a DNS query class, meaning "all classes"
170    kDNSQClass_UnicastResponse = 0x8000 // Top bit set in a question means "unicast response acceptable"
171} DNS_ClassValues;
172
173typedef enum                // From RFC 1035
174{
175    kDNSType_A = 1,         //  1 Address
176    kDNSType_NS,            //  2 Name Server
177    kDNSType_MD,            //  3 Mail Destination
178    kDNSType_MF,            //  4 Mail Forwarder
179    kDNSType_CNAME,         //  5 Canonical Name
180    kDNSType_SOA,           //  6 Start of Authority
181    kDNSType_MB,            //  7 Mailbox
182    kDNSType_MG,            //  8 Mail Group
183    kDNSType_MR,            //  9 Mail Rename
184    kDNSType_NULL,          // 10 NULL RR
185    kDNSType_WKS,           // 11 Well-known-service
186    kDNSType_PTR,           // 12 Domain name pointer
187    kDNSType_HINFO,         // 13 Host information
188    kDNSType_MINFO,         // 14 Mailbox information
189    kDNSType_MX,            // 15 Mail Exchanger
190    kDNSType_TXT,           // 16 Arbitrary text string
191    kDNSType_RP,            // 17 Responsible person
192    kDNSType_AFSDB,         // 18 AFS cell database
193    kDNSType_X25,           // 19 X_25 calling address
194    kDNSType_ISDN,          // 20 ISDN calling address
195    kDNSType_RT,            // 21 Router
196    kDNSType_NSAP,          // 22 NSAP address
197    kDNSType_NSAP_PTR,      // 23 Reverse NSAP lookup (deprecated)
198    kDNSType_SIG,           // 24 Security signature
199    kDNSType_KEY,           // 25 Security key
200    kDNSType_PX,            // 26 X.400 mail mapping
201    kDNSType_GPOS,          // 27 Geographical position (withdrawn)
202    kDNSType_AAAA,          // 28 IPv6 Address
203    kDNSType_LOC,           // 29 Location Information
204    kDNSType_NXT,           // 30 Next domain (security)
205    kDNSType_EID,           // 31 Endpoint identifier
206    kDNSType_NIMLOC,        // 32 Nimrod Locator
207    kDNSType_SRV,           // 33 Service record
208    kDNSType_ATMA,          // 34 ATM Address
209    kDNSType_NAPTR,         // 35 Naming Authority PoinTeR
210    kDNSType_KX,            // 36 Key Exchange
211    kDNSType_CERT,          // 37 Certification record
212    kDNSType_A6,            // 38 IPv6 Address (deprecated)
213    kDNSType_DNAME,         // 39 Non-terminal DNAME (for IPv6)
214    kDNSType_SINK,          // 40 Kitchen sink (experimental)
215    kDNSType_OPT,           // 41 EDNS0 option (meta-RR)
216    kDNSType_APL,           // 42 Address Prefix List
217    kDNSType_DS,            // 43 Delegation Signer
218    kDNSType_SSHFP,         // 44 SSH Key Fingerprint
219    kDNSType_IPSECKEY,      // 45 IPSECKEY
220    kDNSType_RRSIG,         // 46 RRSIG
221    kDNSType_NSEC,          // 47 Denial of Existence
222    kDNSType_DNSKEY,        // 48 DNSKEY
223    kDNSType_DHCID,         // 49 DHCP Client Identifier
224    kDNSType_NSEC3,         // 50 Hashed Authenticated Denial of Existence
225    kDNSType_NSEC3PARAM,    // 51 Hashed Authenticated Denial of Existence
226
227    kDNSType_HIP = 55,      // 55 Host Identity Protocol
228
229    kDNSType_SPF = 99,      // 99 Sender Policy Framework for E-Mail
230    kDNSType_UINFO,         // 100 IANA-Reserved
231    kDNSType_UID,           // 101 IANA-Reserved
232    kDNSType_GID,           // 102 IANA-Reserved
233    kDNSType_UNSPEC,        // 103 IANA-Reserved
234
235    kDNSType_TKEY = 249,    // 249 Transaction key
236    kDNSType_TSIG,          // 250 Transaction signature
237    kDNSType_IXFR,          // 251 Incremental zone transfer
238    kDNSType_AXFR,          // 252 Transfer zone of authority
239    kDNSType_MAILB,         // 253 Transfer mailbox records
240    kDNSType_MAILA,         // 254 Transfer mail agent records
241    kDNSQType_ANY           // Not a DNS type, but a DNS query type, meaning "all types"
242} DNS_TypeValues;
243
244// ***************************************************************************
245#if 0
246#pragma mark -
247#pragma mark - Simple types
248#endif
249
250// mDNS defines its own names for these common types to simplify portability across
251// multiple platforms that may each have their own (different) names for these types.
252typedef unsigned char mDNSBool;
253typedef   signed char mDNSs8;
254typedef unsigned char mDNSu8;
255typedef   signed short mDNSs16;
256typedef unsigned short mDNSu16;
257
258// Source: http://www.unix.org/version2/whatsnew/lp64_wp.html
259// http://software.intel.com/sites/products/documentation/hpc/mkl/lin/MKL_UG_structure/Support_for_ILP64_Programming.htm
260// It can be safely assumed that int is 32bits on the platform
261#if defined(_ILP64) || defined(__ILP64__)
262typedef   signed int32 mDNSs32;
263typedef unsigned int32 mDNSu32;
264#else
265typedef   signed int mDNSs32;
266typedef unsigned int mDNSu32;
267#endif
268
269// To enforce useful type checking, we make mDNSInterfaceID be a pointer to a dummy struct
270// This way, mDNSInterfaceIDs can be assigned, and compared with each other, but not with other types
271// Declaring the type to be the typical generic "void *" would lack this type checking
272typedef struct mDNSInterfaceID_dummystruct { void *dummy; } *mDNSInterfaceID;
273
274// These types are for opaque two- and four-byte identifiers.
275// The "NotAnInteger" fields of the unions allow the value to be conveniently passed around in a
276// register for the sake of efficiency, and compared for equality or inequality, but don't forget --
277// just because it is in a register doesn't mean it is an integer. Operations like greater than,
278// less than, add, multiply, increment, decrement, etc., are undefined for opaque identifiers,
279// and if you make the mistake of trying to do those using the NotAnInteger field, then you'll
280// find you get code that doesn't work consistently on big-endian and little-endian machines.
281#if defined(_WIN32)
282 #pragma pack(push,2)
283#elif !defined(__GNUC__)
284 #pragma pack(1)
285#endif
286typedef       union { mDNSu8 b[ 2]; mDNSu16 NotAnInteger; } mDNSOpaque16;
287typedef       union { mDNSu8 b[ 4]; mDNSu32 NotAnInteger; } mDNSOpaque32;
288typedef packedunion { mDNSu8 b[ 6]; mDNSu16 w[3]; mDNSu32 l[1]; } mDNSOpaque48;
289typedef       union { mDNSu8 b[ 8]; mDNSu16 w[4]; mDNSu32 l[2]; } mDNSOpaque64;
290typedef       union { mDNSu8 b[16]; mDNSu16 w[8]; mDNSu32 l[4]; } mDNSOpaque128;
291#if defined(_WIN32)
292 #pragma pack(pop)
293#elif !defined(__GNUC__)
294 #pragma pack()
295#endif
296
297typedef mDNSOpaque16 mDNSIPPort;        // An IP port is a two-byte opaque identifier (not an integer)
298typedef mDNSOpaque32 mDNSv4Addr;        // An IP address is a four-byte opaque identifier (not an integer)
299typedef mDNSOpaque128 mDNSv6Addr;       // An IPv6 address is a 16-byte opaque identifier (not an integer)
300typedef mDNSOpaque48 mDNSEthAddr;       // An Ethernet address is a six-byte opaque identifier (not an integer)
301
302// Bit operations for opaque 64 bit quantity. Uses the 32 bit quantity(l[2]) to set and clear bits
303#define mDNSNBBY 8
304#define bit_set_opaque64(op64, index) (op64.l[((index))/(sizeof(mDNSu32) * mDNSNBBY)] |= (1 << ((index) % (sizeof(mDNSu32) * mDNSNBBY))))
305#define bit_clr_opaque64(op64, index) (op64.l[((index))/(sizeof(mDNSu32) * mDNSNBBY)] &= ~(1 << ((index) % (sizeof(mDNSu32) * mDNSNBBY))))
306#define bit_get_opaque64(op64, index) (op64.l[((index))/(sizeof(mDNSu32) * mDNSNBBY)] & (1 << ((index) % (sizeof(mDNSu32) * mDNSNBBY))))
307
308// Bit operations for opaque 128 bit quantity. Uses the 32 bit quantity(l[4]) to set and clear bits
309#define bit_set_opaque128(op128, index) (op128.l[((index))/(sizeof(mDNSu32) * mDNSNBBY)] |= (1 << ((index) % (sizeof(mDNSu32) * mDNSNBBY))))
310#define bit_clr_opaque128(op128, index) (op128.l[((index))/(sizeof(mDNSu32) * mDNSNBBY)] &= ~(1 << ((index) % (sizeof(mDNSu32) * mDNSNBBY))))
311#define bit_get_opaque128(op128, index) (op128.l[((index))/(sizeof(mDNSu32) * mDNSNBBY)] & (1 << ((index) % (sizeof(mDNSu32) * mDNSNBBY))))
312
313typedef enum
314{
315    mDNSAddrType_None    = 0,
316    mDNSAddrType_IPv4    = 4,
317    mDNSAddrType_IPv6    = 6,
318    mDNSAddrType_Unknown = ~0   // Special marker value used in known answer list recording
319} mDNSAddr_Type;
320
321typedef enum
322{
323    mDNSTransport_None = 0,
324    mDNSTransport_UDP  = 1,
325    mDNSTransport_TCP  = 2
326} mDNSTransport_Type;
327
328typedef struct
329{
330    mDNSs32 type;
331    union { mDNSv6Addr v6; mDNSv4Addr v4; } ip;
332} mDNSAddr;
333
334enum { mDNSfalse = 0, mDNStrue = 1 };
335
336#define mDNSNULL 0L
337
338enum
339{
340    mStatus_Waiting           = 1,
341    mStatus_NoError           = 0,
342
343    // mDNS return values are in the range FFFE FF00 (-65792) to FFFE FFFF (-65537)
344    // The top end of the range (FFFE FFFF) is used for error codes;
345    // the bottom end of the range (FFFE FF00) is used for non-error values;
346
347    // Error codes:
348    mStatus_UnknownErr                = -65537,     // First value: 0xFFFE FFFF
349    mStatus_NoSuchNameErr             = -65538,
350    mStatus_NoMemoryErr               = -65539,
351    mStatus_BadParamErr               = -65540,
352    mStatus_BadReferenceErr           = -65541,
353    mStatus_BadStateErr               = -65542,
354    mStatus_BadFlagsErr               = -65543,
355    mStatus_UnsupportedErr            = -65544,
356    mStatus_NotInitializedErr         = -65545,
357    mStatus_NoCache                   = -65546,
358    mStatus_AlreadyRegistered         = -65547,
359    mStatus_NameConflict              = -65548,
360    mStatus_Invalid                   = -65549,
361    mStatus_Firewall                  = -65550,
362    mStatus_Incompatible              = -65551,
363    mStatus_BadInterfaceErr           = -65552,
364    mStatus_Refused                   = -65553,
365    mStatus_NoSuchRecord              = -65554,
366    mStatus_NoAuth                    = -65555,
367    mStatus_NoSuchKey                 = -65556,
368    mStatus_NATTraversal              = -65557,
369    mStatus_DoubleNAT                 = -65558,
370    mStatus_BadTime                   = -65559,
371    mStatus_BadSig                    = -65560,     // while we define this per RFC 2845, BIND 9 returns Refused for bad/missing signatures
372    mStatus_BadKey                    = -65561,
373    mStatus_TransientErr              = -65562,     // transient failures, e.g. sending packets shortly after a network transition or wake from sleep
374    mStatus_ServiceNotRunning         = -65563,     // Background daemon not running
375    mStatus_NATPortMappingUnsupported = -65564,     // NAT doesn't support PCP, NAT-PMP or UPnP
376    mStatus_NATPortMappingDisabled    = -65565,     // NAT supports PCP, NAT-PMP or UPnP, but it's disabled by the administrator
377    mStatus_NoRouter                  = -65566,
378    mStatus_PollingMode               = -65567,
379    mStatus_Timeout                   = -65568,
380    mStatus_HostUnreachErr            = -65569,
381    // -65570 to -65786 currently unused; available for allocation
382
383    // tcp connection status
384    mStatus_ConnPending       = -65787,
385    mStatus_ConnFailed        = -65788,
386    mStatus_ConnEstablished   = -65789,
387
388    // Non-error values:
389    mStatus_GrowCache         = -65790,
390    mStatus_ConfigChanged     = -65791,
391    mStatus_MemFree           = -65792      // Last value: 0xFFFE FF00
392                                // mStatus_MemFree is the last legal mDNS error code, at the end of the range allocated for mDNS
393};
394
395typedef mDNSs32 mStatus;
396#define MaxIp 5 // Needs to be consistent with MaxInputIf in dns_services.h
397
398typedef enum { q_stop = 0, q_start } q_state;
399typedef enum { reg_stop = 0, reg_start } reg_state;
400
401// RFC 1034/1035 specify that a domain label consists of a length byte plus up to 63 characters
402#define MAX_DOMAIN_LABEL 63
403typedef struct { mDNSu8 c[ 64]; } domainlabel;      // One label: length byte and up to 63 characters
404
405// RFC 1034/1035/2181 specify that a domain name (length bytes and data bytes) may be up to 255 bytes long,
406// plus the terminating zero at the end makes 256 bytes total in the on-the-wire format.
407#define MAX_DOMAIN_NAME 256
408typedef struct { mDNSu8 c[256]; } domainname;       // Up to 256 bytes of length-prefixed domainlabels
409
410typedef struct { mDNSu8 c[256]; } UTF8str255;       // Null-terminated C string
411
412// The longest legal textual form of a DNS name is 1009 bytes, including the C-string terminating NULL at the end.
413// Explanation:
414// When a native domainname object is converted to printable textual form using ConvertDomainNameToCString(),
415// non-printing characters are represented in the conventional DNS way, as '\ddd', where ddd is a three-digit decimal number.
416// The longest legal domain name is 256 bytes, in the form of four labels as shown below:
417// Length byte, 63 data bytes, length byte, 63 data bytes, length byte, 63 data bytes, length byte, 62 data bytes, zero byte.
418// Each label is encoded textually as characters followed by a trailing dot.
419// If every character has to be represented as a four-byte escape sequence, then this makes the maximum textual form four labels
420// plus the C-string terminating NULL as shown below:
421// 63*4+1 + 63*4+1 + 63*4+1 + 62*4+1 + 1 = 1009.
422// Note that MAX_ESCAPED_DOMAIN_LABEL is not normally used: If you're only decoding a single label, escaping is usually not required.
423// It is for domain names, where dots are used as label separators, that proper escaping is vital.
424#define MAX_ESCAPED_DOMAIN_LABEL 254
425#define MAX_ESCAPED_DOMAIN_NAME 1009
426
427// MAX_REVERSE_MAPPING_NAME
428// For IPv4: "123.123.123.123.in-addr.arpa."  30 bytes including terminating NUL
429// For IPv6: "x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.x.ip6.arpa."  74 bytes including terminating NUL
430
431#define MAX_REVERSE_MAPPING_NAME_V4 30
432#define MAX_REVERSE_MAPPING_NAME_V6 74
433#define MAX_REVERSE_MAPPING_NAME    74
434
435// Most records have a TTL of 75 minutes, so that their 80% cache-renewal query occurs once per hour.
436// For records containing a hostname (in the name on the left, or in the rdata on the right),
437// like A, AAAA, reverse-mapping PTR, and SRV, we use a two-minute TTL by default, because we don't want
438// them to hang around for too long in the cache if the host in question crashes or otherwise goes away.
439
440#define kStandardTTL (3600UL * 100 / 80)
441#define kHostNameTTL 120UL
442
443// Some applications want to register their SRV records with a lower ttl so that in case the server
444// using a dynamic port number restarts, the clients will not have stale information for more than
445// 10 seconds
446
447#define kHostNameSmallTTL 10UL
448
449
450// Multicast DNS uses announcements (gratuitous responses) to update peer caches.
451// This means it is feasible to use relatively larger TTL values than we might otherwise
452// use, because we have a cache coherency protocol to keep the peer caches up to date.
453// With Unicast DNS, once an authoritative server gives a record with a certain TTL value to a client
454// or caching server, that client or caching server is entitled to hold onto the record until its TTL
455// expires, and has no obligation to contact the authoritative server again until that time arrives.
456// This means that whereas Multicast DNS can use announcements to pre-emptively update stale data
457// before it would otherwise have expired, standard Unicast DNS (not using LLQs) has no equivalent
458// mechanism, and TTL expiry is the *only* mechanism by which stale data gets deleted. Because of this,
459// we currently limit the TTL to ten seconds in such cases where no dynamic cache updating is possible.
460#define kStaticCacheTTL 10
461
462#define DefaultTTLforRRType(X) (((X) == kDNSType_A || (X) == kDNSType_AAAA || (X) == kDNSType_SRV) ? kHostNameTTL : kStandardTTL)
463#define mDNS_KeepaliveRecord(rr) ((rr)->rrtype == kDNSType_NULL && SameDomainLabel(SecondLabel((rr)->name)->c, (mDNSu8 *)"\x0A_keepalive"))
464
465// Number of times keepalives are sent if no ACK is received before waking up the system
466// this is analogous to net.inet.tcp.keepcnt
467#define kKeepaliveRetryCount    10
468// The frequency at which keepalives are retried if no ACK is received
469#define kKeepaliveRetryInterval 30
470
471typedef struct AuthRecord_struct AuthRecord;
472typedef struct ServiceRecordSet_struct ServiceRecordSet;
473typedef struct CacheRecord_struct CacheRecord;
474typedef struct CacheGroup_struct CacheGroup;
475typedef struct AuthGroup_struct AuthGroup;
476typedef struct DNSQuestion_struct DNSQuestion;
477typedef struct ZoneData_struct ZoneData;
478typedef struct mDNS_struct mDNS;
479typedef struct mDNS_PlatformSupport_struct mDNS_PlatformSupport;
480typedef struct NATTraversalInfo_struct NATTraversalInfo;
481typedef struct ResourceRecord_struct ResourceRecord;
482
483// Structure to abstract away the differences between TCP/SSL sockets, and one for UDP sockets
484// The actual definition of these structures appear in the appropriate platform support code
485typedef struct TCPSocket_struct TCPSocket;
486typedef struct UDPSocket_struct UDPSocket;
487
488// ***************************************************************************
489#if 0
490#pragma mark -
491#pragma mark - DNS Message structures
492#endif
493
494#define mDNS_numZones   numQuestions
495#define mDNS_numPrereqs numAnswers
496#define mDNS_numUpdates numAuthorities
497
498typedef struct
499{
500    mDNSOpaque16 id;
501    mDNSOpaque16 flags;
502    mDNSu16 numQuestions;
503    mDNSu16 numAnswers;
504    mDNSu16 numAuthorities;
505    mDNSu16 numAdditionals;
506} DNSMessageHeader;
507
508// We can send and receive packets up to 9000 bytes (Ethernet Jumbo Frame size, if that ever becomes widely used)
509// However, in the normal case we try to limit packets to 1500 bytes so that we don't get IP fragmentation on standard Ethernet
510// 40 (IPv6 header) + 8 (UDP header) + 12 (DNS message header) + 1440 (DNS message body) = 1500 total
511#ifndef AbsoluteMaxDNSMessageData
512#define AbsoluteMaxDNSMessageData 8940
513#endif
514#define NormalMaxDNSMessageData 1440
515typedef struct
516{
517    DNSMessageHeader h;                     // Note: Size 12 bytes
518    mDNSu8 data[AbsoluteMaxDNSMessageData]; // 40 (IPv6) + 8 (UDP) + 12 (DNS header) + 8940 (data) = 9000
519} DNSMessage;
520
521typedef struct tcpInfo_t
522{
523    mDNS             *m;
524    TCPSocket        *sock;
525    DNSMessage request;
526    int requestLen;
527    DNSQuestion      *question;   // For queries
528    AuthRecord       *rr;         // For record updates
529    mDNSAddr Addr;
530    mDNSIPPort Port;
531    mDNSIPPort SrcPort;
532    DNSMessage       *reply;
533    mDNSu16 replylen;
534    unsigned long nread;
535    int numReplies;
536} tcpInfo_t;
537
538// ***************************************************************************
539#if 0
540#pragma mark -
541#pragma mark - Other Packet Format Structures
542#endif
543
544typedef packedstruct
545{
546    mDNSEthAddr dst;
547    mDNSEthAddr src;
548    mDNSOpaque16 ethertype;
549} EthernetHeader;           // 14 bytes
550
551typedef packedstruct
552{
553    mDNSOpaque16 hrd;
554    mDNSOpaque16 pro;
555    mDNSu8 hln;
556    mDNSu8 pln;
557    mDNSOpaque16 op;
558    mDNSEthAddr sha;
559    mDNSv4Addr spa;
560    mDNSEthAddr tha;
561    mDNSv4Addr tpa;
562} ARP_EthIP;                // 28 bytes
563
564typedef packedstruct
565{
566    mDNSu8 vlen;
567    mDNSu8 tos;
568    mDNSOpaque16 totlen;
569    mDNSOpaque16 id;
570    mDNSOpaque16 flagsfrags;
571    mDNSu8 ttl;
572    mDNSu8 protocol;        // Payload type: 0x06 = TCP, 0x11 = UDP
573    mDNSu16 checksum;
574    mDNSv4Addr src;
575    mDNSv4Addr dst;
576} IPv4Header;               // 20 bytes
577
578typedef packedstruct
579{
580    mDNSu32 vcf;            // Version, Traffic Class, Flow Label
581    mDNSu16 len;            // Payload Length
582    mDNSu8 pro;             // Type of next header: 0x06 = TCP, 0x11 = UDP, 0x3A = ICMPv6
583    mDNSu8 ttl;             // Hop Limit
584    mDNSv6Addr src;
585    mDNSv6Addr dst;
586} IPv6Header;               // 40 bytes
587
588typedef packedstruct
589{
590    mDNSv6Addr src;
591    mDNSv6Addr dst;
592    mDNSOpaque32 len;
593    mDNSOpaque32 pro;
594} IPv6PseudoHeader;         // 40 bytes
595
596typedef union
597{
598    mDNSu8 bytes[20];
599    ARP_EthIP arp;
600    IPv4Header v4;
601    IPv6Header v6;
602} NetworkLayerPacket;
603
604typedef packedstruct
605{
606    mDNSIPPort src;
607    mDNSIPPort dst;
608    mDNSu32 seq;
609    mDNSu32 ack;
610    mDNSu8 offset;
611    mDNSu8 flags;
612    mDNSu16 window;
613    mDNSu16 checksum;
614    mDNSu16 urgent;
615} TCPHeader;                // 20 bytes; IP protocol type 0x06
616
617typedef struct
618{
619    mDNSInterfaceID IntfId;
620    mDNSu32 seq;
621    mDNSu32 ack;
622    mDNSu16 window;
623} mDNSTCPInfo;
624
625typedef packedstruct
626{
627    mDNSIPPort src;
628    mDNSIPPort dst;
629    mDNSu16 len;            // Length including UDP header (i.e. minimum value is 8 bytes)
630    mDNSu16 checksum;
631} UDPHeader;                // 8 bytes; IP protocol type 0x11
632
633typedef struct
634{
635    mDNSu8 type;            // 0x87 == Neighbor Solicitation, 0x88 == Neighbor Advertisement
636    mDNSu8 code;
637    mDNSu16 checksum;
638    mDNSu32 flags_res;      // R/S/O flags and reserved bits
639    mDNSv6Addr target;
640    // Typically 8 bytes of options are also present
641} IPv6NDP;                  // 24 bytes or more; IP protocol type 0x3A
642
643typedef struct
644{
645    mDNSAddr    ipaddr;
646    char        ethaddr[18];
647} IPAddressMACMapping;
648
649#define NDP_Sol 0x87
650#define NDP_Adv 0x88
651
652#define NDP_Router    0x80
653#define NDP_Solicited 0x40
654#define NDP_Override  0x20
655
656#define NDP_SrcLL 1
657#define NDP_TgtLL 2
658
659typedef union
660{
661    mDNSu8 bytes[20];
662    TCPHeader tcp;
663    UDPHeader udp;
664    IPv6NDP ndp;
665} TransportLayerPacket;
666
667typedef packedstruct
668{
669    mDNSOpaque64 InitiatorCookie;
670    mDNSOpaque64 ResponderCookie;
671    mDNSu8 NextPayload;
672    mDNSu8 Version;
673    mDNSu8 ExchangeType;
674    mDNSu8 Flags;
675    mDNSOpaque32 MessageID;
676    mDNSu32 Length;
677} IKEHeader;                // 28 bytes
678
679// ***************************************************************************
680#if 0
681#pragma mark -
682#pragma mark - Resource Record structures
683#endif
684
685// Authoritative Resource Records:
686// There are four basic types: Shared, Advisory, Unique, Known Unique
687
688// * Shared Resource Records do not have to be unique
689// -- Shared Resource Records are used for DNS-SD service PTRs
690// -- It is okay for several hosts to have RRs with the same name but different RDATA
691// -- We use a random delay on responses to reduce collisions when all the hosts respond to the same query
692// -- These RRs typically have moderately high TTLs (e.g. one hour)
693// -- These records are announced on startup and topology changes for the benefit of passive listeners
694// -- These records send a goodbye packet when deregistering
695//
696// * Advisory Resource Records are like Shared Resource Records, except they don't send a goodbye packet
697//
698// * Unique Resource Records should be unique among hosts within any given mDNS scope
699// -- The majority of Resource Records are of this type
700// -- If two entities on the network have RRs with the same name but different RDATA, this is a conflict
701// -- Responses may be sent immediately, because only one host should be responding to any particular query
702// -- These RRs typically have low TTLs (e.g. a few minutes)
703// -- On startup and after topology changes, a host issues queries to verify uniqueness
704
705// * Known Unique Resource Records are treated like Unique Resource Records, except that mDNS does
706// not have to verify their uniqueness because this is already known by other means (e.g. the RR name
707// is derived from the host's IP or Ethernet address, which is already known to be a unique identifier).
708
709// Summary of properties of different record types:
710// Probe?    Does this record type send probes before announcing?
711// Conflict? Does this record type react if we observe an apparent conflict?
712// Goodbye?  Does this record type send a goodbye packet on departure?
713//
714//               Probe? Conflict? Goodbye? Notes
715// Unregistered                            Should not appear in any list (sanity check value)
716// Shared         No      No       Yes     e.g. Service PTR record
717// Deregistering  No      No       Yes     Shared record about to announce its departure and leave the list
718// Advisory       No      No       No
719// Unique         Yes     Yes      No      Record intended to be unique -- will probe to verify
720// Verified       Yes     Yes      No      Record has completed probing, and is verified unique
721// KnownUnique    No      Yes      No      Record is assumed by other means to be unique
722
723// Valid lifecycle of a record:
724// Unregistered ->                   Shared      -> Deregistering -(goodbye)-> Unregistered
725// Unregistered ->                   Advisory                               -> Unregistered
726// Unregistered -> Unique -(probe)-> Verified                               -> Unregistered
727// Unregistered ->                   KnownUnique                            -> Unregistered
728
729// Each Authoritative kDNSRecordType has only one bit set. This makes it easy to quickly see if a record
730// is one of a particular set of types simply by performing the appropriate bitwise masking operation.
731
732// Cache Resource Records (received from the network):
733// There are four basic types: Answer, Unique Answer, Additional, Unique Additional
734// Bit 7 (the top bit) of kDNSRecordType is always set for Cache Resource Records; always clear for Authoritative Resource Records
735// Bit 6 (value 0x40) is set for answer records; clear for authority/additional records
736// Bit 5 (value 0x20) is set for records received with the kDNSClass_UniqueRRSet
737
738typedef enum
739{
740    kDNSRecordTypeUnregistered     = 0x00,  // Not currently in any list
741    kDNSRecordTypeDeregistering    = 0x01,  // Shared record about to announce its departure and leave the list
742
743    kDNSRecordTypeUnique           = 0x02,  // Will become a kDNSRecordTypeVerified when probing is complete
744
745    kDNSRecordTypeAdvisory         = 0x04,  // Like Shared, but no goodbye packet
746    kDNSRecordTypeShared           = 0x08,  // Shared means record name does not have to be unique -- use random delay on responses
747
748    kDNSRecordTypeVerified         = 0x10,  // Unique means mDNS should check that name is unique (and then send immediate responses)
749    kDNSRecordTypeKnownUnique      = 0x20,  // Known Unique means mDNS can assume name is unique without checking
750                                            // For Dynamic Update records, Known Unique means the record must already exist on the server.
751    kDNSRecordTypeUniqueMask       = (kDNSRecordTypeUnique | kDNSRecordTypeVerified | kDNSRecordTypeKnownUnique),
752    kDNSRecordTypeActiveSharedMask = (kDNSRecordTypeAdvisory         | kDNSRecordTypeShared),
753    kDNSRecordTypeActiveUniqueMask = (kDNSRecordTypeVerified         | kDNSRecordTypeKnownUnique),
754    kDNSRecordTypeActiveMask       = (kDNSRecordTypeActiveSharedMask | kDNSRecordTypeActiveUniqueMask),
755
756    kDNSRecordTypePacketAdd        = 0x80,  // Received in the Additional  Section of a DNS Response
757    kDNSRecordTypePacketAddUnique  = 0x90,  // Received in the Additional  Section of a DNS Response with kDNSClass_UniqueRRSet set
758    kDNSRecordTypePacketAuth       = 0xA0,  // Received in the Authorities Section of a DNS Response
759    kDNSRecordTypePacketAuthUnique = 0xB0,  // Received in the Authorities Section of a DNS Response with kDNSClass_UniqueRRSet set
760    kDNSRecordTypePacketAns        = 0xC0,  // Received in the Answer      Section of a DNS Response
761    kDNSRecordTypePacketAnsUnique  = 0xD0,  // Received in the Answer      Section of a DNS Response with kDNSClass_UniqueRRSet set
762
763    kDNSRecordTypePacketNegative   = 0xF0,  // Pseudo-RR generated to cache non-existence results like NXDomain
764
765    kDNSRecordTypePacketUniqueMask = 0x10   // True for PacketAddUnique, PacketAnsUnique, PacketAuthUnique, kDNSRecordTypePacketNegative
766} kDNSRecordTypes;
767
768typedef packedstruct { mDNSu16 priority; mDNSu16 weight; mDNSIPPort port; domainname target;   } rdataSRV;
769typedef packedstruct { mDNSu16 preference;                                domainname exchange; } rdataMX;
770typedef packedstruct { domainname mbox; domainname txt;                                        } rdataRP;
771typedef packedstruct { mDNSu16 preference; domainname map822; domainname mapx400;              } rdataPX;
772
773typedef packedstruct
774{
775    domainname mname;
776    domainname rname;
777    mDNSs32 serial;     // Modular counter; increases when zone changes
778    mDNSu32 refresh;    // Time in seconds that a slave waits after successful replication of the database before it attempts replication again
779    mDNSu32 retry;      // Time in seconds that a slave waits after an unsuccessful replication attempt before it attempts replication again
780    mDNSu32 expire;     // Time in seconds that a slave holds on to old data while replication attempts remain unsuccessful
781    mDNSu32 min;        // Nominally the minimum record TTL for this zone, in seconds; also used for negative caching.
782} rdataSOA;
783
784// http://www.iana.org/assignments/dns-sec-alg-numbers/dns-sec-alg-numbers.xhtml
785// Algorithm used for RRSIG, DS and DNS KEY
786#define CRYPTO_RSA_SHA1             0x05
787#define CRYPTO_DSA_NSEC3_SHA1       0x06
788#define CRYPTO_RSA_NSEC3_SHA1       0x07
789#define CRYPTO_RSA_SHA256           0x08
790#define CRYPTO_RSA_SHA512           0x0A
791
792#define CRYPTO_ALG_MAX              0x0B
793
794// alg - same as in RRSIG, DNS KEY or DS.
795// RFC 4034 defines SHA1
796// RFC 4509 defines SHA256
797// Note: NSEC3 also uses 1 for SHA1 and hence we will reuse for now till a new
798// value is assigned.
799//
800#define SHA1_DIGEST_TYPE        1
801#define SHA256_DIGEST_TYPE      2
802#define DIGEST_TYPE_MAX         3
803
804// We need support for base64 and base32 encoding for displaying KEY, NSEC3
805// To make this platform agnostic, we define two types which the platform
806// needs to support
807#define ENC_BASE32              1
808#define ENC_BASE64              2
809#define ENC_ALG_MAX             3
810
811#define DS_FIXED_SIZE           4
812typedef packedstruct
813{
814    mDNSu16 keyTag;
815    mDNSu8 alg;
816    mDNSu8 digestType;
817    mDNSu8  *digest;
818} rdataDS;
819
820typedef struct TrustAnchor
821{
822    struct TrustAnchor *next;
823    int digestLen;
824    mDNSu32 validFrom;
825    mDNSu32 validUntil;
826    domainname zone;
827    rdataDS rds;
828} TrustAnchor;
829
830//size of rdataRRSIG excluding signerName and signature (which are variable fields)
831#define RRSIG_FIXED_SIZE      18
832typedef struct
833{
834    mDNSu16 typeCovered;
835    mDNSu8 alg;
836    mDNSu8 labels;
837    mDNSu32 origTTL;
838    mDNSu32 sigExpireTime;
839    mDNSu32 sigInceptTime;
840    mDNSu16 keyTag;
841    mDNSu8  signerName[1]; // signerName is a dynamically-sized array
842    // mDNSu8 *signature
843} rdataRRSig;
844
845// RFC 4034: For DNS Key RR
846// flags - the valid value for DNSSEC is 256 (Zone signing key - ZSK) and 257 (Secure Entry Point) which also
847// includes the ZSK bit
848//
849#define DNSKEY_ZONE_SIGN_KEY        0x100
850#define DNSKEY_SECURE_ENTRY_POINT   0x101
851
852// proto - the only valid value for protocol is 3 (See RFC 4034)
853#define DNSKEY_VALID_PROTO_VALUE    0x003
854
855// alg - The only mandatory algorithm that we support is RSA/SHA-1
856// DNSSEC_RSA_SHA1_ALG
857
858#define DNSKEY_FIXED_SIZE          4
859typedef packedstruct
860{
861    mDNSu16 flags;
862    mDNSu8 proto;
863    mDNSu8 alg;
864    mDNSu8  *data;
865} rdataDNSKey;
866
867#define NSEC3_FIXED_SIZE          5
868#define NSEC3_FLAGS_OPTOUT        1
869#define NSEC3_MAX_ITERATIONS      2500
870typedef packedstruct
871{
872    mDNSu8 alg;
873    mDNSu8 flags;
874    mDNSu16 iterations;
875    mDNSu8 saltLength;
876    mDNSu8 *salt;
877    // hashLength, nxt, bitmap
878} rdataNSEC3;
879
880// In the multicast usage of NSEC3, we know the actual size of RData
881// 4 bytes : HashAlg, Flags,Iterations
882// 5 bytes : Salt Length 1 byte, Salt 4 bytes
883// 21 bytes : HashLength 1 byte, Hash 20 bytes
884// 34 bytes : Window number, Bitmap length, Type bit map to include the first 256 types
885#define MCAST_NSEC3_RDLENGTH (4 + 5 + 21 + 34)
886#define SHA1_HASH_LENGTH 20
887
888// Base32 encoding takes 5 bytes of the input and encodes as 8 bytes of output.
889// For example, SHA-1 hash of 20 bytes will be encoded as 20/5 * 8 = 32 base32
890// bytes. For a max domain name size of 255 bytes of base32 encoding : (255/8)*5
891// is the max hash length possible.
892#define NSEC3_MAX_HASH_LEN  155
893// In NSEC3, the names are hashed and stored in the first label and hence cannot exceed label
894// size.
895#define NSEC3_MAX_B32_LEN   MAX_DOMAIN_LABEL
896
897// We define it here instead of dnssec.h so that these values can be used
898// in files without bringing in all of dnssec.h unnecessarily.
899typedef enum
900{
901    DNSSEC_Secure = 1,      // Securely validated and has a chain up to the trust anchor
902    DNSSEC_Insecure,        // Cannot build a chain up to the trust anchor
903    DNSSEC_Indeterminate,   // Not used currently
904    DNSSEC_Bogus,           // failed to validate signatures
905    DNSSEC_NoResponse       // No DNSSEC records to start with
906} DNSSECStatus;
907
908#define DNSSECRecordType(rrtype) (((rrtype) == kDNSType_RRSIG) || ((rrtype) == kDNSType_NSEC) || ((rrtype) == kDNSType_DNSKEY) || ((rrtype) == kDNSType_DS) || \
909                                  ((rrtype) == kDNSType_NSEC3))
910
911typedef enum
912{
913    platform_OSX = 1,   // OSX Platform
914    platform_iOS,       // iOS Platform
915    platform_Atv,       // Atv Platform
916    platform_NonApple   // Non-Apple (Windows, POSIX) Platform
917} Platform_t;
918
919// EDNS Option Code registrations are recorded in the "DNS EDNS0 Options" section of
920// <http://www.iana.org/assignments/dns-parameters>
921
922#define kDNSOpt_LLQ   1
923#define kDNSOpt_Lease 2
924#define kDNSOpt_NSID  3
925#define kDNSOpt_Owner 4
926#define kDNSOpt_Trace 65001  // 65001-65534 Reserved for Local/Experimental Use
927
928typedef struct
929{
930    mDNSu16 vers;
931    mDNSu16 llqOp;
932    mDNSu16 err;        // Or UDP reply port, in setup request
933    // Note: In the in-memory form, there's typically a two-byte space here, so that the following 64-bit id is word-aligned
934    mDNSOpaque64 id;
935    mDNSu32 llqlease;
936} LLQOptData;
937
938typedef struct
939{
940    mDNSu8 vers;            // Version number of this Owner OPT record
941    mDNSs8 seq;             // Sleep/wake epoch
942    mDNSEthAddr HMAC;       // Host's primary identifier (e.g. MAC of on-board Ethernet)
943    mDNSEthAddr IMAC;       // Interface's MAC address (if different to primary MAC)
944    mDNSOpaque48 password;  // Optional password
945} OwnerOptData;
946
947typedef struct
948{
949    mDNSu8    platf;      // Running platform (see enum Platform_t)
950    mDNSu32   mDNSv;      // mDNSResponder Version (DNS_SD_H defined in dns_sd.h)
951} TracerOptData;
952
953// Note: rdataOPT format may be repeated an arbitrary number of times in a single resource record
954typedef struct
955{
956    mDNSu16 opt;
957    mDNSu16 optlen;
958    union { LLQOptData llq; mDNSu32 updatelease; OwnerOptData owner; TracerOptData tracer; } u;
959} rdataOPT;
960
961// Space needed to put OPT records into a packet:
962// Header         11  bytes (name 1, type 2, class 2, TTL 4, length 2)
963// LLQ   rdata    18  bytes (opt 2, len 2, vers 2, op 2, err 2, id 8, lease 4)
964// Lease rdata     8  bytes (opt 2, len 2, lease 4)
965// Owner rdata 12-24  bytes (opt 2, len 2, owner 8-20)
966// Trace rdata     9  bytes (opt 2, len 2, platf 1, mDNSv 4)
967
968
969#define DNSOpt_Header_Space                 11
970#define DNSOpt_LLQData_Space               (4 + 2 + 2 + 2 + 8 + 4)
971#define DNSOpt_LeaseData_Space             (4 + 4)
972#define DNSOpt_OwnerData_ID_Space          (4 + 2 + 6)
973#define DNSOpt_OwnerData_ID_Wake_Space     (4 + 2 + 6 + 6)
974#define DNSOpt_OwnerData_ID_Wake_PW4_Space (4 + 2 + 6 + 6 + 4)
975#define DNSOpt_OwnerData_ID_Wake_PW6_Space (4 + 2 + 6 + 6 + 6)
976#define DNSOpt_TraceData_Space             (4 + 1 + 4)
977
978#define ValidOwnerLength(X) (   (X) == DNSOpt_OwnerData_ID_Space          - 4 || \
979                                (X) == DNSOpt_OwnerData_ID_Wake_Space     - 4 || \
980                                (X) == DNSOpt_OwnerData_ID_Wake_PW4_Space - 4 || \
981                                (X) == DNSOpt_OwnerData_ID_Wake_PW6_Space - 4    )
982
983#define DNSOpt_Owner_Space(A,B) (mDNSSameEthAddress((A),(B)) ? DNSOpt_OwnerData_ID_Space : DNSOpt_OwnerData_ID_Wake_Space)
984
985#define DNSOpt_Data_Space(O) (                                  \
986        (O)->opt == kDNSOpt_LLQ   ? DNSOpt_LLQData_Space   :        \
987        (O)->opt == kDNSOpt_Lease ? DNSOpt_LeaseData_Space :        \
988        (O)->opt == kDNSOpt_Trace ? DNSOpt_TraceData_Space :        \
989        (O)->opt == kDNSOpt_Owner ? DNSOpt_Owner_Space(&(O)->u.owner.HMAC, &(O)->u.owner.IMAC) : 0x10000)
990
991// NSEC record is defined in RFC 4034.
992// 16 bit RRTYPE space is split into 256 windows and each window has 256 bits (32 bytes).
993// If we create a structure for NSEC, it's size would be:
994//
995//   256 bytes domainname 'nextname'
996// + 256 * 34 = 8704 bytes of bitmap data
997// = 8960 bytes total
998//
999// This would be a waste, as types about 256 are not very common. But it would be odd, if we receive
1000// a type above 256 (.US zone had TYPE65534 when this code was written) and not able to handle it.
1001// Hence, we handle any size by not fixing a strucure in place. The following is just a placeholder
1002// and never used anywhere.
1003//
1004#define NSEC_MCAST_WINDOW_SIZE 32
1005typedef struct
1006{
1007    domainname *next; //placeholders are uncommented because C89 in Windows requires that a struct has at least a member.
1008    char bitmap[32];
1009} rdataNSEC;
1010
1011// StandardAuthRDSize is 264 (256+8), which is large enough to hold a maximum-sized SRV record (6 + 256 bytes)
1012// MaximumRDSize is 8K the absolute maximum we support (at least for now)
1013#define StandardAuthRDSize 264
1014#ifndef MaximumRDSize
1015#define MaximumRDSize 8192
1016#endif
1017
1018// InlineCacheRDSize is 68
1019// Records received from the network with rdata this size or less have their rdata stored right in the CacheRecord object
1020// Records received from the network with rdata larger than this have additional storage allocated for the rdata
1021// A quick unscientific sample from a busy network at Apple with lots of machines revealed this:
1022// 1461 records in cache
1023// 292 were one-byte TXT records
1024// 136 were four-byte A records
1025// 184 were sixteen-byte AAAA records
1026// 780 were various PTR, TXT and SRV records from 12-64 bytes
1027// Only 69 records had rdata bigger than 64 bytes
1028// Note that since CacheRecord object and a CacheGroup object are allocated out of the same pool, it's sensible to
1029// have them both be the same size. Making one smaller without making the other smaller won't actually save any memory.
1030#define InlineCacheRDSize 68
1031
1032// The RDataBody union defines the common rdata types that fit into our 264-byte limit
1033typedef union
1034{
1035    mDNSu8 data[StandardAuthRDSize];
1036    mDNSv4Addr ipv4;        // For 'A' record
1037    domainname name;        // For PTR, NS, CNAME, DNAME
1038    UTF8str255 txt;
1039    rdataMX mx;
1040    mDNSv6Addr ipv6;        // For 'AAAA' record
1041    rdataSRV srv;
1042    rdataOPT opt[2];        // For EDNS0 OPT record; RDataBody may contain multiple variable-length rdataOPT objects packed together
1043} RDataBody;
1044
1045// The RDataBody2 union is the same as above, except it includes fields for the larger types like soa, rp, px
1046typedef union
1047{
1048    mDNSu8 data[StandardAuthRDSize];
1049    mDNSv4Addr ipv4;        // For 'A' record
1050    domainname name;        // For PTR, NS, CNAME, DNAME
1051    rdataSOA soa;           // This is large; not included in the normal RDataBody definition
1052    UTF8str255 txt;
1053    rdataMX mx;
1054    rdataRP rp;             // This is large; not included in the normal RDataBody definition
1055    rdataPX px;             // This is large; not included in the normal RDataBody definition
1056    mDNSv6Addr ipv6;        // For 'AAAA' record
1057    rdataSRV srv;
1058    rdataOPT opt[2];        // For EDNS0 OPT record; RDataBody may contain multiple variable-length rdataOPT objects packed together
1059    rdataDS ds;
1060    rdataDNSKey key;
1061    rdataRRSig rrsig;
1062} RDataBody2;
1063
1064typedef struct
1065{
1066    mDNSu16 MaxRDLength;    // Amount of storage allocated for rdata (usually sizeof(RDataBody))
1067    mDNSu16 padding;        // So that RDataBody is aligned on 32-bit boundary
1068    RDataBody u;
1069} RData;
1070
1071// sizeofRDataHeader should be 4 bytes
1072#define sizeofRDataHeader (sizeof(RData) - sizeof(RDataBody))
1073
1074// RData_small is a smaller version of the RData object, used for inline data storage embedded in a CacheRecord_struct
1075typedef struct
1076{
1077    mDNSu16 MaxRDLength;    // Storage allocated for data (may be greater than InlineCacheRDSize if additional storage follows this object)
1078    mDNSu16 padding;        // So that data is aligned on 32-bit boundary
1079    mDNSu8 data[InlineCacheRDSize];
1080} RData_small;
1081
1082// Note: Within an mDNSRecordCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Exit(), mDNS_Execute()
1083typedef void mDNSRecordCallback (mDNS *const m, AuthRecord *const rr, mStatus result);
1084
1085// Note:
1086// Restrictions: An mDNSRecordUpdateCallback may not make any mDNS API calls.
1087// The intent of this callback is to allow the client to free memory, if necessary.
1088// The internal data structures of the mDNS code may not be in a state where mDNS API calls may be made safely.
1089typedef void mDNSRecordUpdateCallback (mDNS *const m, AuthRecord *const rr, RData *OldRData, mDNSu16 OldRDLen);
1090
1091// ***************************************************************************
1092#if 0
1093#pragma mark -
1094#pragma mark - NAT Traversal structures and constants
1095#endif
1096
1097#define NATMAP_MAX_RETRY_INTERVAL    ((mDNSPlatformOneSecond * 60) * 15)    // Max retry interval is 15 minutes
1098#define NATMAP_MIN_RETRY_INTERVAL     (mDNSPlatformOneSecond * 2)           // Min retry interval is 2 seconds
1099#define NATMAP_INIT_RETRY             (mDNSPlatformOneSecond / 4)           // start at 250ms w/ exponential decay
1100#define NATMAP_DEFAULT_LEASE          (60 * 60 * 2)                         // 2 hour lease life in seconds
1101#define NATMAP_VERS 0
1102
1103typedef enum
1104{
1105    NATOp_AddrRequest    = 0,
1106    NATOp_MapUDP         = 1,
1107    NATOp_MapTCP         = 2,
1108
1109    NATOp_AddrResponse   = 0x80 | 0,
1110    NATOp_MapUDPResponse = 0x80 | 1,
1111    NATOp_MapTCPResponse = 0x80 | 2,
1112} NATOp_t;
1113
1114enum
1115{
1116    NATErr_None    = 0,
1117    NATErr_Vers    = 1,
1118    NATErr_Refused = 2,
1119    NATErr_NetFail = 3,
1120    NATErr_Res     = 4,
1121    NATErr_Opcode  = 5
1122};
1123
1124typedef mDNSu16 NATErr_t;
1125
1126typedef packedstruct
1127{
1128    mDNSu8 vers;
1129    mDNSu8 opcode;
1130} NATAddrRequest;
1131
1132typedef packedstruct
1133{
1134    mDNSu8 vers;
1135    mDNSu8 opcode;
1136    mDNSu16 err;
1137    mDNSu32 upseconds;          // Time since last NAT engine reboot, in seconds
1138    mDNSv4Addr ExtAddr;
1139} NATAddrReply;
1140
1141typedef packedstruct
1142{
1143    mDNSu8 vers;
1144    mDNSu8 opcode;
1145    mDNSOpaque16 unused;
1146    mDNSIPPort intport;
1147    mDNSIPPort extport;
1148    mDNSu32 NATReq_lease;
1149} NATPortMapRequest;
1150
1151typedef packedstruct
1152{
1153    mDNSu8 vers;
1154    mDNSu8 opcode;
1155    mDNSu16 err;
1156    mDNSu32 upseconds;          // Time since last NAT engine reboot, in seconds
1157    mDNSIPPort intport;
1158    mDNSIPPort extport;
1159    mDNSu32 NATRep_lease;
1160} NATPortMapReply;
1161
1162// PCP Support for IPv4 mappings
1163
1164#define PCP_VERS 0x02
1165#define PCP_WAITSECS_AFTER_EPOCH_INVALID 5
1166
1167typedef enum
1168{
1169    PCPOp_Announce = 0,
1170    PCPOp_Map      = 1
1171} PCPOp_t;
1172
1173typedef enum
1174{
1175    PCPProto_All = 0,
1176    PCPProto_TCP = 6,
1177    PCPProto_UDP = 17
1178} PCPProto_t;
1179
1180typedef enum
1181{
1182    PCPResult_Success         = 0,
1183    PCPResult_UnsuppVersion   = 1,
1184    PCPResult_NotAuthorized   = 2,
1185    PCPResult_MalformedReq    = 3,
1186    PCPResult_UnsuppOpcode    = 4,
1187    PCPResult_UnsuppOption    = 5,
1188    PCPResult_MalformedOption = 6,
1189    PCPResult_NetworkFailure  = 7,
1190    PCPResult_NoResources     = 8,
1191    PCPResult_UnsuppProtocol  = 9,
1192    PCPResult_UserExQuota     = 10,
1193    PCPResult_CantProvideExt  = 11,
1194    PCPResult_AddrMismatch    = 12,
1195    PCPResult_ExcesRemotePeer = 13
1196} PCPResult_t;
1197
1198typedef struct
1199{
1200    mDNSu8       version;
1201    mDNSu8       opCode;
1202    mDNSOpaque16 reserved;
1203    mDNSu32      lifetime;
1204    mDNSv6Addr   clientAddr;
1205    mDNSu32      nonce[3];
1206    mDNSu8       protocol;
1207    mDNSu8       reservedMapOp[3];
1208    mDNSIPPort   intPort;
1209    mDNSIPPort   extPort;
1210    mDNSv6Addr   extAddress;
1211} PCPMapRequest;
1212
1213typedef struct
1214{
1215    mDNSu8     version;
1216    mDNSu8     opCode;
1217    mDNSu8     reserved;
1218    mDNSu8     result;
1219    mDNSu32    lifetime;
1220    mDNSu32    epoch;
1221    mDNSu32    clientAddrParts[3];
1222    mDNSu32    nonce[3];
1223    mDNSu8     protocol;
1224    mDNSu8     reservedMapOp[3];
1225    mDNSIPPort intPort;
1226    mDNSIPPort extPort;
1227    mDNSv6Addr extAddress;
1228} PCPMapReply;
1229
1230// LNT Support
1231
1232typedef enum
1233{
1234    LNTDiscoveryOp      = 1,
1235    LNTExternalAddrOp   = 2,
1236    LNTPortMapOp        = 3,
1237    LNTPortMapDeleteOp  = 4
1238} LNTOp_t;
1239
1240#define LNT_MAXBUFSIZE 8192
1241typedef struct tcpLNTInfo_struct tcpLNTInfo;
1242struct tcpLNTInfo_struct
1243{
1244    tcpLNTInfo       *next;
1245    mDNS             *m;
1246    NATTraversalInfo *parentNATInfo;    // pointer back to the parent NATTraversalInfo
1247    TCPSocket        *sock;
1248    LNTOp_t op;                         // operation performed using this connection
1249    mDNSAddr Address;                   // router address
1250    mDNSIPPort Port;                    // router port
1251    mDNSu8           *Request;          // xml request to router
1252    int requestLen;
1253    mDNSu8           *Reply;            // xml reply from router
1254    int replyLen;
1255    unsigned long nread;                // number of bytes read so far
1256    int retries;                        // number of times we've tried to do this port mapping
1257};
1258
1259typedef void (*NATTraversalClientCallback)(mDNS *m, NATTraversalInfo *n);
1260
1261// if m->timenow <  ExpiryTime then we have an active mapping, and we'll renew halfway to expiry
1262// if m->timenow >= ExpiryTime then our mapping has expired, and we're trying to create one
1263
1264typedef enum
1265{
1266    NATTProtocolNone    = 0,
1267    NATTProtocolNATPMP  = 1,
1268    NATTProtocolUPNPIGD = 2,
1269    NATTProtocolPCP     = 3,
1270} NATTProtocol;
1271
1272struct NATTraversalInfo_struct
1273{
1274    // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
1275    NATTraversalInfo           *next;
1276
1277    mDNSs32 ExpiryTime;                             // Time this mapping expires, or zero if no mapping
1278    mDNSs32 retryInterval;                          // Current interval, between last packet we sent and the next one
1279    mDNSs32 retryPortMap;                           // If Protocol is nonzero, time to send our next mapping packet
1280    mStatus NewResult;                              // New error code; will be copied to Result just prior to invoking callback
1281    NATTProtocol lastSuccessfulProtocol;            // To send correct deletion request & update non-PCP external address operations
1282    mDNSBool sentNATPMP;                            // Whether we just sent a NAT-PMP packet, so we won't send another if
1283                                                    //    we receive another NAT-PMP "Unsupported Version" packet
1284
1285#ifdef _LEGACY_NAT_TRAVERSAL_
1286    tcpLNTInfo tcpInfo;                             // Legacy NAT traversal (UPnP) TCP connection
1287#endif
1288
1289    // Result fields: When the callback is invoked these fields contain the answers the client is looking for
1290    // When the callback is invoked ExternalPort is *usually* set to be the same the same as RequestedPort, except:
1291    // (a) When we're behind a NAT gateway with port mapping disabled, ExternalPort is reported as zero to
1292    //     indicate that we don't currently have a working mapping (but RequestedPort retains the external port
1293    //     we'd like to get, the next time we meet an accomodating NAT gateway willing to give us one).
1294    // (b) When we have a routable non-RFC1918 address, we don't *need* a port mapping, so ExternalPort
1295    //     is reported as the same as our InternalPort, since that is effectively our externally-visible port too.
1296    //     Again, RequestedPort retains the external port we'd like to get the next time we find ourself behind a NAT gateway.
1297    // To improve stability of port mappings, RequestedPort is updated any time we get a successful
1298    // mapping response from the PCP, NAT-PMP or UPnP gateway. For example, if we ask for port 80, and
1299    // get assigned port 81, then thereafter we'll contine asking for port 81.
1300    mDNSInterfaceID InterfaceID;
1301    mDNSv4Addr ExternalAddress;                     // Initially set to onesIPv4Addr, until first callback
1302    mDNSv4Addr NewAddress;                          // May be updated with actual value assigned by gateway
1303    mDNSIPPort ExternalPort;
1304    mDNSu32 Lifetime;
1305    mStatus Result;
1306
1307    // Client API fields: The client must set up these fields *before* making any NAT traversal API calls
1308    mDNSu8 Protocol;                                // NATOp_MapUDP or NATOp_MapTCP, or zero if just requesting the external IP address
1309    mDNSIPPort IntPort;                             // Client's internal port number (doesn't change)
1310    mDNSIPPort RequestedPort;                       // Requested external port; may be updated with actual value assigned by gateway
1311    mDNSu32 NATLease;                               // Requested lifetime in seconds (doesn't change)
1312    NATTraversalClientCallback clientCallback;
1313    void                       *clientContext;
1314};
1315
1316// ***************************************************************************
1317#if 0
1318#pragma mark -
1319#pragma mark - DNSServer & McastResolver structures and constants
1320#endif
1321
1322enum
1323{
1324    DNSServer_FlagDelete      = 0x1,
1325    DNSServer_FlagNew         = 0x2,
1326#if APPLE_OSX_mDNSResponder
1327    DNSServer_FlagUnreachable = 0x4,
1328#endif
1329};
1330
1331enum
1332{
1333    McastResolver_FlagDelete = 1,
1334    McastResolver_FlagNew    = 2
1335};
1336
1337typedef struct McastResolver
1338{
1339    struct McastResolver *next;
1340    mDNSInterfaceID interface;
1341    mDNSu32 flags;              // Set when we're planning to delete this from the list
1342    domainname domain;
1343    mDNSu32 timeout;            // timeout value for questions
1344} McastResolver;
1345
1346enum {
1347    Mortality_Mortal      = 0,          // This cache record can expire and get purged
1348    Mortality_Immortal    = 1,          // Allow this record to remain in the cache indefinitely
1349    Mortality_Ghost       = 2           // An immortal record that has expired and can linger in the cache
1350};
1351typedef mDNSu8 MortalityState;
1352
1353// scoped values for DNSServer matching
1354enum
1355{
1356    kScopeNone         = 0,        // DNS server used by unscoped questions
1357    kScopeInterfaceID  = 1,        // Scoped DNS server used only by scoped questions
1358    kScopeServiceID    = 2,         // Service specific DNS server used only by questions
1359                                   // have a matching serviceID
1360    kScopesMaxCount    = 3         // Max count for scopes enum
1361};
1362
1363// Note: DNSSECAware is set if we are able to get a valid response to
1364// a DNSSEC question. In some cases it is possible that the proxy
1365// strips the EDNS0 option and we just get a plain response with no
1366// signatures. But we still mark DNSSECAware in that case. As DNSSECAware
1367// is only used to determine whether DNSSEC_VALIDATION_SECURE_OPTIONAL
1368// should be turned off or not, it is sufficient that we are getting
1369// responses back.
1370typedef struct DNSServer
1371{
1372    struct DNSServer *next;
1373    mDNSInterfaceID interface;  // DNS requests should be sent on this interface
1374    mDNSs32 serviceID;
1375    mDNSAddr addr;
1376    mDNSIPPort port;
1377    mDNSu32 flags;              // Set when we're planning to delete this from the list
1378    domainname domain;          // name->server matching for "split dns"
1379    mDNSs32 penaltyTime;        // amount of time this server is penalized
1380    mDNSu32 scoped;             // See the scoped enum above
1381    mDNSu32 timeout;            // timeout value for questions
1382    mDNSu16 resGroupID;         // ID of the resolver group that contains this DNSServer
1383    mDNSu8 retransDO;           // Total Retransmissions for queries sent with DO option
1384    mDNSBool cellIntf;          // Resolver from Cellular Interface?
1385    mDNSBool req_A;             // If set, send v4 query (DNSConfig allows A queries)
1386    mDNSBool req_AAAA;          // If set, send v6 query (DNSConfig allows AAAA queries)
1387    mDNSBool req_DO;            // If set, okay to send DNSSEC queries (EDNS DO bit is supported)
1388    mDNSBool DNSSECAware;       // Set if we are able to receive a response to a request sent with DO option.
1389    mDNSBool isExpensive;       // True if the interface to this server is expensive.
1390    mDNSBool isCLAT46;          // True if the interface to this server is CLAT46.
1391} DNSServer;
1392
1393typedef struct
1394{
1395    mDNSu8 *AnonData;
1396    int AnonDataLen;
1397    mDNSu32 salt;
1398    ResourceRecord *nsec3RR;
1399    mDNSInterfaceID SendNow;     // The interface ID that this record should be sent on
1400} AnonymousInfo;
1401
1402struct ResourceRecord_struct
1403{
1404    mDNSu8 RecordType;                  // See kDNSRecordTypes enum.
1405    MortalityState mortality;           // Mortality of this resource record (See MortalityState enum)
1406    mDNSu16 rrtype;                     // See DNS_TypeValues enum.
1407    mDNSu16 rrclass;                    // See DNS_ClassValues enum.
1408    mDNSu32 rroriginalttl;              // In seconds
1409    mDNSu16 rdlength;                   // Size of the raw rdata, in bytes, in the on-the-wire format
1410                                        // (In-memory storage may be larger, for structures containing 'holes', like SOA)
1411    mDNSu16 rdestimate;                 // Upper bound on on-the-wire size of rdata after name compression
1412    mDNSu32 namehash;                   // Name-based (i.e. case-insensitive) hash of name
1413    mDNSu32 rdatahash;                  // For rdata containing domain name (e.g. PTR, SRV, CNAME etc.), case-insensitive name hash
1414                                        // else, for all other rdata, 32-bit hash of the raw rdata
1415                                        // Note: This requirement is important. Various routines like AddAdditionalsToResponseList(),
1416                                        // ReconfirmAntecedents(), etc., use rdatahash as a pre-flight check to see
1417                                        // whether it's worth doing a full SameDomainName() call. If the rdatahash
1418                                        // is not a correct case-insensitive name hash, they'll get false negatives.
1419    // Grouping pointers together at the end of the structure improves the memory layout efficiency
1420    mDNSInterfaceID InterfaceID;        // Set if this RR is specific to one interface
1421                                        // For records received off the wire, InterfaceID is *always* set to the receiving interface
1422                                        // For our authoritative records, InterfaceID is usually zero, except for those few records
1423                                        // that are interface-specific (e.g. address records, especially linklocal addresses)
1424    const domainname *name;
1425    RData           *rdata;             // Pointer to storage for this rdata
1426    DNSServer       *rDNSServer;        // Unicast DNS server authoritative for this entry; null for multicast
1427    AnonymousInfo   *AnonInfo;          // Anonymous Information
1428};
1429
1430
1431// Unless otherwise noted, states may apply to either independent record registrations or service registrations
1432typedef enum
1433{
1434    regState_Zero              = 0,
1435    regState_Pending           = 1,     // update sent, reply not received
1436    regState_Registered        = 2,     // update sent, reply received
1437    regState_DeregPending      = 3,     // dereg sent, reply not received
1438    regState_Unregistered      = 4,     // not in any list
1439    regState_Refresh           = 5,     // outstanding refresh (or target change) message
1440    regState_NATMap            = 6,     // establishing NAT port mapping
1441    regState_UpdatePending     = 7,     // update in flight as result of mDNS_Update call
1442    regState_NoTarget          = 8,     // SRV Record registration pending registration of hostname
1443    regState_NATError          = 9     // unable to complete NAT traversal
1444} regState_t;
1445
1446enum
1447{
1448    Target_Manual = 0,
1449    Target_AutoHost = 1,
1450    Target_AutoHostAndNATMAP = 2
1451};
1452
1453typedef enum
1454{
1455    mergeState_Zero = 0,
1456    mergeState_DontMerge = 1  // Set on fatal error conditions to disable merging
1457} mergeState_t;
1458
1459#define AUTH_GROUP_NAME_SIZE    128
1460struct AuthGroup_struct             // Header object for a list of AuthRecords with the same name
1461{
1462    AuthGroup      *next;               // Next AuthGroup object in this hash table bucket
1463    mDNSu32 namehash;                   // Name-based (i.e. case insensitive) hash of name
1464    AuthRecord     *members;            // List of CacheRecords with this same name
1465    AuthRecord    **rrauth_tail;        // Tail end of that list
1466    domainname     *name;               // Common name for all AuthRecords in this list
1467    AuthRecord     *NewLocalOnlyRecords;
1468    mDNSu8 namestorage[AUTH_GROUP_NAME_SIZE];
1469};
1470
1471#ifndef AUTH_HASH_SLOTS
1472#define AUTH_HASH_SLOTS 499
1473#endif
1474#define FORALL_AUTHRECORDS(SLOT,AG,AR)                              \
1475    for ((SLOT) = 0; (SLOT) < AUTH_HASH_SLOTS; (SLOT)++)                                                                     \
1476        for ((AG)=m->rrauth.rrauth_hash[(SLOT)]; (AG); (AG)=(AG)->next)                                                                         \
1477            for ((AR) = (AG)->members; (AR); (AR)=(AR)->next)
1478
1479typedef union AuthEntity_union AuthEntity;
1480union AuthEntity_union { AuthEntity *next; AuthGroup ag; };
1481typedef struct {
1482    mDNSu32 rrauth_size;                // Total number of available auth entries
1483    mDNSu32 rrauth_totalused;           // Number of auth entries currently occupied
1484    mDNSu32 rrauth_report;
1485    mDNSu8 rrauth_lock;                 // For debugging: Set at times when these lists may not be modified
1486    AuthEntity *rrauth_free;
1487    AuthGroup *rrauth_hash[AUTH_HASH_SLOTS];
1488}AuthHash;
1489
1490// AuthRecordAny includes mDNSInterface_Any and interface specific auth records.
1491typedef enum
1492{
1493    AuthRecordAny,              // registered for *Any, NOT including P2P interfaces
1494    AuthRecordAnyIncludeP2P,    // registered for *Any, including P2P interfaces
1495    AuthRecordAnyIncludeAWDL,   // registered for *Any, including AWDL interface
1496    AuthRecordAnyIncludeAWDLandP2P, // registered for *Any, including AWDL and P2P interfaces
1497    AuthRecordLocalOnly,
1498    AuthRecordP2P               // discovered over D2D/P2P framework
1499} AuthRecType;
1500
1501typedef enum
1502{
1503    AuthFlagsWakeOnly = 0x1     // WakeOnly service
1504} AuthRecordFlags;
1505
1506struct AuthRecord_struct
1507{
1508    // For examples of how to set up this structure for use in mDNS_Register(),
1509    // see mDNS_AdvertiseInterface() or mDNS_RegisterService().
1510    // Basically, resrec and persistent metadata need to be set up before calling mDNS_Register().
1511    // mDNS_SetupResourceRecord() is avaliable as a helper routine to set up most fields to sensible default values for you
1512
1513    AuthRecord     *next;               // Next in list; first element of structure for efficiency reasons
1514    // Field Group 1: Common ResourceRecord fields
1515    ResourceRecord resrec;              // 36 bytes when compiling for 32-bit; 48 when compiling for 64-bit (now 44/64)
1516
1517    // Field Group 2: Persistent metadata for Authoritative Records
1518    AuthRecord     *Additional1;        // Recommended additional record to include in response (e.g. SRV for PTR record)
1519    AuthRecord     *Additional2;        // Another additional (e.g. TXT for PTR record)
1520    AuthRecord     *DependentOn;        // This record depends on another for its uniqueness checking
1521    AuthRecord     *RRSet;              // This unique record is part of an RRSet
1522    mDNSRecordCallback *RecordCallback; // Callback function to call for state changes, and to free memory asynchronously on deregistration
1523    void           *RecordContext;      // Context parameter for the callback function
1524    mDNSu8 AutoTarget;                  // Set if the target of this record (PTR, CNAME, SRV, etc.) is our host name
1525    mDNSu8 AllowRemoteQuery;            // Set if we allow hosts not on the local link to query this record
1526    mDNSu8 ForceMCast;                  // Set by client to advertise solely via multicast, even for apparently unicast names
1527    mDNSu8 AuthFlags;
1528
1529    OwnerOptData WakeUp;                // WakeUp.HMAC.l[0] nonzero indicates that this is a Sleep Proxy record
1530    mDNSAddr AddressProxy;              // For reverse-mapping Sleep Proxy PTR records, address in question
1531    mDNSs32 TimeRcvd;                   // In platform time units
1532    mDNSs32 TimeExpire;                 // In platform time units
1533    AuthRecType ARType;                 // LocalOnly, P2P or Normal ?
1534    mDNSs32 KATimeExpire;               // In platform time units: time to send keepalive packet for the proxy record
1535
1536    // Field Group 3: Transient state for Authoritative Records
1537    mDNSu8 Acknowledged;                // Set if we've given the success callback to the client
1538    mDNSu8 ProbeRestartCount;           // Number of times we have restarted probing
1539    mDNSu8 ProbeCount;                  // Number of probes remaining before this record is valid (kDNSRecordTypeUnique)
1540    mDNSu8 AnnounceCount;               // Number of announcements remaining (kDNSRecordTypeShared)
1541    mDNSu8 RequireGoodbye;              // Set if this RR has been announced on the wire and will require a goodbye packet
1542    mDNSu8 AnsweredLocalQ;              // Set if this AuthRecord has been delivered to any local question (LocalOnly or mDNSInterface_Any)
1543    mDNSu8 IncludeInProbe;              // Set if this RR is being put into a probe right now
1544    mDNSu8 ImmedUnicast;                // Set if we may send our response directly via unicast to the requester
1545    mDNSInterfaceID SendNSECNow;        // Set if we need to generate associated NSEC data for this rrname
1546    mDNSInterfaceID ImmedAnswer;        // Someone on this interface issued a query we need to answer (all-ones for all interfaces)
1547#if MDNS_LOG_ANSWER_SUPPRESSION_TIMES
1548    mDNSs32 ImmedAnswerMarkTime;
1549#endif
1550    mDNSInterfaceID ImmedAdditional;    // Hint that we might want to also send this record, just to be helpful
1551    mDNSInterfaceID SendRNow;           // The interface this query is being sent on right now
1552    mDNSv4Addr v4Requester;             // Recent v4 query for this record, or all-ones if more than one recent query
1553    mDNSv6Addr v6Requester;             // Recent v6 query for this record, or all-ones if more than one recent query
1554    AuthRecord     *NextResponse;       // Link to the next element in the chain of responses to generate
1555    const mDNSu8   *NR_AnswerTo;        // Set if this record was selected by virtue of being a direct answer to a question
1556    AuthRecord     *NR_AdditionalTo;    // Set if this record was selected by virtue of being additional to another
1557    mDNSs32 ThisAPInterval;             // In platform time units: Current interval for announce/probe
1558    mDNSs32 LastAPTime;                 // In platform time units: Last time we sent announcement/probe
1559    mDNSs32 LastMCTime;                 // Last time we multicast this record (used to guard against packet-storm attacks)
1560    mDNSInterfaceID LastMCInterface;    // Interface this record was multicast on at the time LastMCTime was recorded
1561    RData          *NewRData;           // Set if we are updating this record with new rdata
1562    mDNSu16 newrdlength;                // ... and the length of the new RData
1563    mDNSRecordUpdateCallback *UpdateCallback;
1564    mDNSu32 UpdateCredits;              // Token-bucket rate limiting of excessive updates
1565    mDNSs32 NextUpdateCredit;           // Time next token is added to bucket
1566    mDNSs32 UpdateBlocked;              // Set if update delaying is in effect
1567
1568    // Field Group 4: Transient uDNS state for Authoritative Records
1569    regState_t state;           // Maybe combine this with resrec.RecordType state? Right now it's ambiguous and confusing.
1570                                // e.g. rr->resrec.RecordType can be kDNSRecordTypeUnregistered,
1571                                // and rr->state can be regState_Unregistered
1572                                // What if we find one of those statements is true and the other false? What does that mean?
1573    mDNSBool uselease;          // dynamic update contains (should contain) lease option
1574    mDNSs32 expire;             // In platform time units: expiration of lease (-1 for static)
1575    mDNSBool Private;           // If zone is private, DNS updates may have to be encrypted to prevent eavesdropping
1576    mDNSOpaque16 updateid;      // Identifier to match update request and response -- also used when transferring records to Sleep Proxy
1577    mDNSOpaque64 updateIntID;   // Interface IDs (one bit per interface index)to which updates have been sent
1578    const domainname *zone;     // the zone that is updated
1579    ZoneData  *nta;
1580    struct tcpInfo_t *tcp;
1581    NATTraversalInfo NATinfo;
1582    mDNSBool SRVChanged;       // temporarily deregistered service because its SRV target or port changed
1583    mergeState_t mState;       // Unicast Record Registrations merge state
1584    mDNSu8 refreshCount;        // Number of refreshes to the server
1585    mStatus updateError;        // Record update resulted in Error ?
1586
1587    // uDNS_UpdateRecord support fields
1588    // Do we really need all these in *addition* to NewRData and newrdlength above?
1589    void *UpdateContext;    // Context parameter for the update callback function
1590    mDNSu16 OrigRDLen;      // previously registered, being deleted
1591    mDNSu16 InFlightRDLen;  // currently being registered
1592    mDNSu16 QueuedRDLen;    // pending operation (re-transmitting if necessary) THEN register the queued update
1593    RData *OrigRData;
1594    RData *InFlightRData;
1595    RData *QueuedRData;
1596
1597    // Field Group 5: Large data objects go at the end
1598    domainname namestorage;
1599    RData rdatastorage;                 // Normally the storage is right here, except for oversized records
1600    // rdatastorage MUST be the last thing in the structure -- when using oversized AuthRecords, extra bytes
1601    // are appended after the end of the AuthRecord, logically augmenting the size of the rdatastorage
1602    // DO NOT ADD ANY MORE FIELDS HERE
1603};
1604
1605// IsLocalDomain alone is not sufficient to determine that a record is mDNS or uDNS. By default domain names within
1606// the "local" pseudo-TLD (and within the IPv4 and IPv6 link-local reverse mapping domains) are automatically treated
1607// as mDNS records, but it is also possible to force any record (even those not within one of the inherently local
1608// domains) to be handled as an mDNS record by setting the ForceMCast flag, or by setting a non-zero InterfaceID.
1609// For example, the reverse-mapping PTR record created in AdvertiseInterface sets the ForceMCast flag, since it points to
1610// a dot-local hostname, and therefore it would make no sense to register this record with a wide-area Unicast DNS server.
1611// The same applies to Sleep Proxy records, which we will answer for when queried via mDNS, but we never want to try
1612// to register them with a wide-area Unicast DNS server -- and we probably don't have the required credentials anyway.
1613// Currently we have no concept of a wide-area uDNS record scoped to a particular interface, so if the InterfaceID is
1614// nonzero we treat this the same as ForceMCast.
1615// Note: Question_uDNS(Q) is used in *only* one place -- on entry to mDNS_StartQuery_internal, to decide whether to set TargetQID.
1616// Everywhere else in the code, the determination of whether a question is unicast is made by checking to see if TargetQID is nonzero.
1617#define AuthRecord_uDNS(R) ((R)->resrec.InterfaceID == mDNSInterface_Any && !(R)->ForceMCast && !IsLocalDomain((R)->resrec.name))
1618#define Question_uDNS(Q)   ((Q)->InterfaceID == mDNSInterface_Unicast || (Q)->ProxyQuestion || \
1619                            ((Q)->InterfaceID != mDNSInterface_LocalOnly && (Q)->InterfaceID != mDNSInterface_P2P && (Q)->InterfaceID != mDNSInterface_BLE && !(Q)->ForceMCast && !IsLocalDomain(&(Q)->qname)))
1620
1621// AuthRecordLocalOnly records are registered using mDNSInterface_LocalOnly and
1622// AuthRecordP2P records are created by D2DServiceFound events.  Both record types are kept on the same list.
1623#define RRLocalOnly(rr) ((rr)->ARType == AuthRecordLocalOnly || (rr)->ARType == AuthRecordP2P)
1624
1625// All other auth records, not including those defined as RRLocalOnly().
1626#define RRAny(rr) ((rr)->ARType == AuthRecordAny || (rr)->ARType == AuthRecordAnyIncludeP2P || (rr)->ARType == AuthRecordAnyIncludeAWDL || (rr)->ARType == AuthRecordAnyIncludeAWDLandP2P)
1627
1628// Question (A or AAAA) that is suppressed currently because IPv4 or IPv6 address
1629// is not available locally for A or AAAA question respectively. Also, if the
1630// query is disallowed for the "pid" that we are sending on behalf of, suppress it.
1631#define QuerySuppressed(Q) (((Q)->SuppressUnusable && (Q)->SuppressQuery) || ((Q)->DisallowPID))
1632
1633#define PrivateQuery(Q) ((Q)->AuthInfo && (Q)->AuthInfo->AutoTunnel)
1634
1635// Normally we always lookup the cache and /etc/hosts before sending the query on the wire. For single label
1636// queries (A and AAAA) that are unqualified (indicated by AppendSearchDomains), we want to append search
1637// domains before we try them as such
1638#define ApplySearchDomainsFirst(q) ((q)->AppendSearchDomains && (CountLabels(&((q)->qname))) == 1)
1639
1640// Wrapper struct for Auth Records for higher-level code that cannot use the AuthRecord's ->next pointer field
1641typedef struct ARListElem
1642{
1643    struct ARListElem *next;
1644    AuthRecord ar;          // Note: Must be last element of structure, to accomodate oversized AuthRecords
1645} ARListElem;
1646
1647struct CacheRecord_struct
1648{
1649    CacheRecord    *next;               // Next in list; first element of structure for efficiency reasons
1650    ResourceRecord resrec;              // 36 bytes when compiling for 32-bit; 48 when compiling for 64-bit (now 44/64)
1651
1652    // Transient state for Cache Records
1653    CacheRecord    *NextInKAList;       // Link to the next element in the chain of known answers to send
1654    mDNSs32 TimeRcvd;                   // In platform time units
1655    mDNSs32 DelayDelivery;              // Set if we want to defer delivery of this answer to local clients
1656    mDNSs32 NextRequiredQuery;          // In platform time units
1657    // Extra four bytes here (on 64bit)
1658    DNSQuestion    *CRActiveQuestion;   // Points to an active question referencing this answer. Can never point to a NewQuestion.
1659    mDNSs32 LastUnansweredTime;         // In platform time units; last time we incremented UnansweredQueries
1660    mDNSu8  UnansweredQueries;          // Number of times we've issued a query for this record without getting an answer
1661    mDNSu8  CRDNSSECQuestion;           // Set to 1 if this was created in response to a DNSSEC question
1662    mDNSOpaque16 responseFlags;         // Second 16 bit in the DNS response
1663    CacheRecord    *NextInCFList;       // Set if this is in the list of records we just received with the cache flush bit set
1664    CacheRecord    *nsec;               // NSEC records needed for non-existence proofs
1665    CacheRecord    *soa;                // SOA record to return for proxy questions
1666
1667    mDNSAddr sourceAddress;             // node from which we received this record
1668    // Size to here is 76 bytes when compiling 32-bit; 104 bytes when compiling 64-bit (now 160 bytes for 64-bit)
1669    RData_small smallrdatastorage;      // Storage for small records is right here (4 bytes header + 68 bytes data = 72 bytes)
1670};
1671
1672// Should match the CacheGroup_struct members, except namestorage[].  Only used to calculate
1673// the size of the namestorage array in CacheGroup_struct so that sizeof(CacheGroup) == sizeof(CacheRecord)
1674struct CacheGroup_base
1675{
1676    CacheGroup     *next;
1677    mDNSu32         namehash;
1678    CacheRecord    *members;
1679    CacheRecord   **rrcache_tail;
1680    domainname     *name;
1681};
1682
1683struct CacheGroup_struct                // Header object for a list of CacheRecords with the same name
1684{
1685    CacheGroup     *next;               // Next CacheGroup object in this hash table bucket
1686    mDNSu32         namehash;           // Name-based (i.e. case insensitive) hash of name
1687    CacheRecord    *members;            // List of CacheRecords with this same name
1688    CacheRecord   **rrcache_tail;       // Tail end of that list
1689    domainname     *name;               // Common name for all CacheRecords in this list
1690    mDNSu8 namestorage[sizeof(CacheRecord) - sizeof(struct CacheGroup_base)];  // match sizeof(CacheRecord)
1691};
1692
1693// Storage sufficient to hold either a CacheGroup header or a CacheRecord
1694// -- for best efficiency (to avoid wasted unused storage) they should be the same size
1695typedef union CacheEntity_union CacheEntity;
1696union CacheEntity_union { CacheEntity *next; CacheGroup cg; CacheRecord cr; };
1697
1698typedef struct
1699{
1700    CacheRecord r;
1701    mDNSu8 _extradata[MaximumRDSize-InlineCacheRDSize];     // Glue on the necessary number of extra bytes
1702    domainname namestorage;                                 // Needs to go *after* the extra rdata bytes
1703} LargeCacheRecord;
1704
1705typedef struct HostnameInfo
1706{
1707    struct HostnameInfo *next;
1708    NATTraversalInfo natinfo;
1709    domainname fqdn;
1710    AuthRecord arv4;                          // registered IPv4 address record
1711    AuthRecord arv6;                          // registered IPv6 address record
1712    mDNSRecordCallback *StatusCallback;       // callback to deliver success or error code to client layer
1713    const void *StatusContext;                // Client Context
1714} HostnameInfo;
1715
1716typedef struct ExtraResourceRecord_struct ExtraResourceRecord;
1717struct ExtraResourceRecord_struct
1718{
1719    ExtraResourceRecord *next;
1720    mDNSu32 ClientID;  // Opaque ID field to be used by client to map an AddRecord call to a set of Extra records
1721    AuthRecord r;
1722    // Note: Add any additional fields *before* the AuthRecord in this structure, not at the end.
1723    // In some cases clients can allocate larger chunks of memory and set r->rdata->MaxRDLength to indicate
1724    // that this extra memory is available, which would result in any fields after the AuthRecord getting smashed
1725};
1726
1727// Note: Within an mDNSServiceCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Exit(), mDNS_Execute()
1728typedef void mDNSServiceCallback (mDNS *const m, ServiceRecordSet *const sr, mStatus result);
1729
1730// A ServiceRecordSet has no special meaning to the core code of the Multicast DNS protocol engine;
1731// it is just a convenience structure to group together the records that make up a standard service
1732// registration so that they can be allocted and deallocted together as a single memory object.
1733// It contains its own ServiceCallback+ServiceContext to report aggregate results up to the next layer of software above.
1734// It also contains:
1735//  * the basic PTR/SRV/TXT triplet used to represent any DNS-SD service
1736//  * the "_services" PTR record for service enumeration
1737//  * the optional list of SubType PTR records
1738//  * the optional list of additional records attached to the service set (e.g. iChat pictures)
1739
1740struct ServiceRecordSet_struct
1741{
1742    // These internal state fields are used internally by mDNSCore; the client layer needn't be concerned with them.
1743    // No fields need to be set up by the client prior to calling mDNS_RegisterService();
1744    // all required data is passed as parameters to that function.
1745    mDNSServiceCallback *ServiceCallback;
1746    void                *ServiceContext;
1747    mDNSBool Conflict;              // Set if this record set was forcibly deregistered because of a conflict
1748
1749    ExtraResourceRecord *Extras;    // Optional list of extra AuthRecords attached to this service registration
1750    mDNSu32 NumSubTypes;
1751    AuthRecord          *SubTypes;
1752    const mDNSu8        *AnonData;
1753    mDNSu32             flags;      // saved for subsequent calls to mDNS_RegisterService() if records
1754                                    // need to be re-registered.
1755    AuthRecord RR_ADV;              // e.g. _services._dns-sd._udp.local. PTR _printer._tcp.local.
1756    AuthRecord RR_PTR;              // e.g. _printer._tcp.local.        PTR Name._printer._tcp.local.
1757    AuthRecord RR_SRV;              // e.g. Name._printer._tcp.local.   SRV 0 0 port target
1758    AuthRecord RR_TXT;              // e.g. Name._printer._tcp.local.   TXT PrintQueueName
1759    // Don't add any fields after AuthRecord RR_TXT.
1760    // This is where the implicit extra space goes if we allocate a ServiceRecordSet containing an oversized RR_TXT record
1761};
1762
1763// ***************************************************************************
1764#if 0
1765#pragma mark -
1766#pragma mark - Question structures
1767#endif
1768
1769// We record the last eight instances of each duplicate query
1770// This gives us v4/v6 on each of Ethernet, AirPort and Firewire, and two free slots "for future expansion"
1771// If the host has more active interfaces that this it is not fatal -- duplicate question suppression will degrade gracefully.
1772// Since we will still remember the last eight, the busiest interfaces will still get the effective duplicate question suppression.
1773#define DupSuppressInfoSize 8
1774
1775typedef struct
1776{
1777    mDNSs32 Time;
1778    mDNSInterfaceID InterfaceID;
1779    mDNSs32 Type;                           // v4 or v6?
1780} DupSuppressInfo;
1781
1782typedef enum
1783{
1784    LLQ_InitialRequest    = 1,
1785    LLQ_SecondaryRequest  = 2,
1786    LLQ_Established       = 3,
1787    LLQ_Poll              = 4
1788} LLQ_State;
1789
1790// LLQ constants
1791#define kLLQ_Vers      1
1792#define kLLQ_DefLease  7200 // 2 hours
1793#define kLLQ_MAX_TRIES 3    // retry an operation 3 times max
1794#define kLLQ_INIT_RESEND 2 // resend an un-ack'd packet after 2 seconds, then double for each additional
1795// LLQ Operation Codes
1796#define kLLQOp_Setup     1
1797#define kLLQOp_Refresh   2
1798#define kLLQOp_Event     3
1799
1800// LLQ Errror Codes
1801enum
1802{
1803    LLQErr_NoError    = 0,
1804    LLQErr_ServFull   = 1,
1805    LLQErr_Static     = 2,
1806    LLQErr_FormErr    = 3,
1807    LLQErr_NoSuchLLQ  = 4,
1808    LLQErr_BadVers    = 5,
1809    LLQErr_UnknownErr = 6
1810};
1811
1812enum { NoAnswer_Normal = 0, NoAnswer_Suspended = 1, NoAnswer_Fail = 2 };
1813
1814// DNS Push Notification
1815typedef enum
1816{
1817    DNSPUSH_NOERROR  = 0,
1818    DNSPUSH_FORMERR  = 1,
1819    DNSPUSH_SERVFAIL = 2,
1820    DNSPUSH_NOTIMP   = 4,
1821    DNSPUSH_REFUSED  = 5
1822} DNSPUSH_ErrorCode;
1823
1824typedef enum {
1825    DNSPUSH_INIT         = 1,
1826    DNSPUSH_NOSERVER     = 2,
1827    DNSPUSH_SERVERFOUND  = 3,
1828    DNSPUSH_ESTABLISHED  = 4
1829} DNSPush_State;
1830
1831enum {
1832    AllowExpired_None = 0,                  // Don't allow expired answers or mark answers immortal (behave normally)
1833    AllowExpired_MakeAnswersImmortal = 1,   // Any answers to this question get marked as immortal
1834    AllowExpired_AllowExpiredAnswers = 2    // Allow already expired answers from the cache
1835};
1836typedef mDNSu8 AllowExpiredState;
1837
1838#define HMAC_LEN    64
1839#define HMAC_IPAD   0x36
1840#define HMAC_OPAD   0x5c
1841#define MD5_LEN     16
1842
1843#define AutoTunnelUnregistered(X) (                                               \
1844        (X)->AutoTunnelHostRecord.resrec.RecordType == kDNSRecordTypeUnregistered && \
1845        (X)->AutoTunnelTarget.resrec.RecordType == kDNSRecordTypeUnregistered && \
1846        (X)->AutoTunnelDeviceInfo.resrec.RecordType == kDNSRecordTypeUnregistered && \
1847        (X)->AutoTunnelService.resrec.RecordType == kDNSRecordTypeUnregistered && \
1848        (X)->AutoTunnel6Record.resrec.RecordType == kDNSRecordTypeUnregistered )
1849
1850// Internal data structure to maintain authentication information
1851typedef struct DomainAuthInfo
1852{
1853    struct DomainAuthInfo *next;
1854    mDNSs32 deltime;                        // If we're planning to delete this DomainAuthInfo, the time we want it deleted
1855    mDNSBool   AutoTunnel;                  // Whether this is AutoTunnel
1856    AuthRecord AutoTunnelHostRecord;        // User-visible hostname; used as SRV target for AutoTunnel services
1857    AuthRecord AutoTunnelTarget;            // Opaque hostname of tunnel endpoint; used as SRV target for AutoTunnelService record
1858    AuthRecord AutoTunnelDeviceInfo;        // Device info of tunnel endpoint
1859    AuthRecord AutoTunnelService;           // Service record (possibly NAT-Mapped) of IKE daemon implementing tunnel endpoint
1860    AuthRecord AutoTunnel6Record;           // AutoTunnel AAAA Record obtained from awacsd
1861    mDNSBool AutoTunnelServiceStarted;         // Whether a service has been registered in this domain
1862    mDNSv6Addr AutoTunnelInnerAddress;
1863    domainname domain;
1864    domainname keyname;
1865    domainname hostname;
1866    mDNSIPPort port;
1867    char b64keydata[32];
1868    mDNSu8 keydata_ipad[HMAC_LEN];              // padded key for inner hash rounds
1869    mDNSu8 keydata_opad[HMAC_LEN];              // padded key for outer hash rounds
1870} DomainAuthInfo;
1871
1872// Note: Within an mDNSQuestionCallback mDNS all API calls are legal except mDNS_Init(), mDNS_Exit(), mDNS_Execute()
1873// Note: Any value other than QC_rmv i.e., any non-zero value will result in kDNSServiceFlagsAdd to the application
1874// layer. These values are used within mDNSResponder and not sent across to the application. QC_addnocache is for
1875// delivering a response without adding to the cache. QC_forceresponse is superset of QC_addnocache where in
1876// addition to not entering in the cache, it also forces the negative response through.
1877typedef enum { QC_rmv = 0, QC_add, QC_addnocache, QC_forceresponse, QC_dnssec , QC_nodnssec, QC_suppressed } QC_result;
1878typedef void mDNSQuestionCallback (mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord);
1879typedef void AsyncDispatchFunc(mDNS *const m, void *context);
1880typedef void DNSSECAuthInfoFreeCallback(mDNS *const m, void *context);
1881extern void mDNSPlatformDispatchAsync(mDNS *const m, void *context, AsyncDispatchFunc func);
1882
1883#define NextQSendTime(Q)  ((Q)->LastQTime + (Q)->ThisQInterval)
1884#define ActiveQuestion(Q) ((Q)->ThisQInterval > 0 && !(Q)->DuplicateOf)
1885#define TimeToSendThisQuestion(Q,time) (ActiveQuestion(Q) && (time) - NextQSendTime(Q) >= 0)
1886
1887// q->ValidationStatus is either DNSSECValNotRequired or DNSSECValRequired and then moves onto DNSSECValInProgress.
1888// When Validation is done, we mark all "DNSSECValInProgress" questions "DNSSECValDone". If we are answering
1889// questions from /etc/hosts, then we go straight to DNSSECValDone from the initial state.
1890typedef enum { DNSSECValNotRequired = 0, DNSSECValRequired, DNSSECValInProgress, DNSSECValDone } DNSSECValState;
1891
1892// ValidationRequired can be set to the following values:
1893//
1894// SECURE validation is set to determine whether something is secure or bogus
1895// INSECURE validation is set internally by dnssec code to indicate that it is currently proving something
1896// is insecure
1897#define DNSSEC_VALIDATION_NONE              0x00
1898#define DNSSEC_VALIDATION_SECURE            0x01
1899#define DNSSEC_VALIDATION_SECURE_OPTIONAL   0x02
1900#define DNSSEC_VALIDATION_INSECURE          0x03
1901
1902// For both ValidationRequired and ValidatingResponse question, we validate DNSSEC responses.
1903// For ProxyQuestion with DNSSECOK, we just receive the DNSSEC records to pass them along without
1904// validation and if the CD bit is not set, we also validate.
1905#define DNSSECQuestion(q) ((q)->ValidationRequired || (q)->ValidatingResponse || ((q)->ProxyQuestion && (q)->ProxyDNSSECOK))
1906
1907// ValidatingQuestion is used when we need to know whether we are validating the DNSSEC responses for a question
1908#define ValidatingQuestion(q) ((q)->ValidationRequired || (q)->ValidatingResponse)
1909
1910#define DNSSECOptionalQuestion(q) ((q)->ValidationRequired == DNSSEC_VALIDATION_SECURE_OPTIONAL)
1911
1912// Given the resource record and the question, should we follow the CNAME ?
1913#define FollowCNAME(q, rr, AddRecord)   (AddRecord && (q)->qtype != kDNSType_CNAME && \
1914                                         (rr)->RecordType != kDNSRecordTypePacketNegative && \
1915                                         (rr)->rrtype == kDNSType_CNAME)
1916
1917// RFC 4122 defines it to be 16 bytes
1918#define UUID_SIZE       16
1919
1920#define AWD_METRICS (USE_AWD && TARGET_OS_IOS)
1921
1922#if AWD_METRICS
1923
1924enum
1925{
1926    ExpiredAnswer_None = 0,                  // No expired answers used
1927    ExpiredAnswer_Allowed = 1,               // An expired answer is allowed by this request
1928    ExpiredAnswer_AnsweredWithExpired = 2,   // Question was answered with an expired answer
1929    ExpiredAnswer_ExpiredAnswerChanged = 3,  // Expired answer changed on refresh
1930
1931    ExpiredAnswer_EnumCount
1932};
1933typedef mDNSu8 ExpiredAnswerMetric;
1934
1935typedef struct
1936{
1937    domainname *        originalQName;          // Name of original A/AAAA record if this question is for a CNAME record.
1938    mDNSu32             querySendCount;         // Number of queries that have been sent to DNS servers so far.
1939    mDNSs32             firstQueryTime;         // The time when the first query was sent to a DNS server.
1940    mDNSBool            answered;               // Has this question been answered?
1941    ExpiredAnswerMetric expiredAnswerState;     // Expired answer state (see ExpiredAnswerMetric above)
1942
1943}   uDNSMetrics;
1944#endif
1945
1946// DNS64 code is only for iOS, which is currently the only Apple OS that supports DNS proxy network extensions.
1947#define USE_DNS64 (HAVE_DNS64 && TARGET_OS_IOS)
1948
1949#if USE_DNS64
1950#include "DNS64State.h"
1951#endif
1952
1953#if TARGET_OS_EMBEDDED
1954extern mDNSu32 curr_num_regservices; // tracks the current number of services registered
1955extern mDNSu32 max_num_regservices;  // tracks the max number of simultaneous services registered by the device
1956#endif
1957
1958struct DNSQuestion_struct
1959{
1960    // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
1961    DNSQuestion          *next;
1962    mDNSu32 qnamehash;
1963    mDNSs32 DelayAnswering;                 // Set if we want to defer answering this question until the cache settles
1964    mDNSs32 LastQTime;                      // Last scheduled transmission of this Q on *all* applicable interfaces
1965    mDNSs32 ThisQInterval;                  // LastQTime + ThisQInterval is the next scheduled transmission of this Q
1966                                            // ThisQInterval > 0 for an active question;
1967                                            // ThisQInterval = 0 for a suspended question that's still in the list
1968                                            // ThisQInterval = -1 for a cancelled question (should not still be in list)
1969    mDNSs32 ExpectUnicastResp;              // Set when we send a query with the kDNSQClass_UnicastResponse bit set
1970    mDNSs32 LastAnswerPktNum;               // The sequence number of the last response packet containing an answer to this Q
1971    mDNSu32 RecentAnswerPkts;               // Number of answers since the last time we sent this query
1972    mDNSu32 CurrentAnswers;                 // Number of records currently in the cache that answer this question
1973    mDNSu32 BrowseThreshold;                // If we have received at least this number of answers,
1974                                            // set the next question interval to MaxQuestionInterval
1975    mDNSu32 LargeAnswers;                   // Number of answers with rdata > 1024 bytes
1976    mDNSu32 UniqueAnswers;                  // Number of answers received with kDNSClass_UniqueRRSet bit set
1977    mDNSInterfaceID FlappingInterface1;     // Set when an interface goes away, to flag if remove events are delivered for this Q
1978    mDNSInterfaceID FlappingInterface2;     // Set when an interface goes away, to flag if remove events are delivered for this Q
1979    DomainAuthInfo       *AuthInfo;         // Non-NULL if query is currently being done using Private DNS
1980    DNSQuestion          *DuplicateOf;
1981    DNSQuestion          *NextInDQList;
1982    AnonymousInfo        *AnonInfo;         // Anonymous Information
1983    DupSuppressInfo DupSuppress[DupSuppressInfoSize];
1984    mDNSInterfaceID SendQNow;               // The interface this query is being sent on right now
1985    mDNSBool SendOnAll;                     // Set if we're sending this question on all active interfaces
1986    mDNSBool CachedAnswerNeedsUpdate;       // See SendQueries().  Set if we're sending this question
1987                                            // because a cached answer needs to be refreshed.
1988    mDNSu32 RequestUnicast;                 // Non-zero if we want to send query with kDNSQClass_UnicastResponse bit set
1989    mDNSs32 LastQTxTime;                    // Last time this Q was sent on one (but not necessarily all) interfaces
1990    mDNSu32 CNAMEReferrals;                 // Count of how many CNAME redirections we've done
1991    mDNSBool SuppressQuery;                 // This query should be suppressed and not sent on the wire
1992    mDNSu8 LOAddressAnswers;                // Number of answers from the local only auth records that are
1993                                            // answering A, AAAA, CNAME, or PTR (/etc/hosts)
1994    mDNSu8 WakeOnResolveCount;              // Number of wakes that should be sent on resolve
1995    mDNSs32 StopTime;                       // Time this question should be stopped by giving them a negative answer
1996
1997    // DNSSEC fields
1998    DNSSECValState ValidationState;            // Current state of the Validation process
1999    DNSSECStatus ValidationStatus;             // Validation status for "ValidationRequired" questions (dnssec)
2000    mDNSu8 ValidatingResponse;                 // Question trying to validate a response (dnssec) on behalf of
2001                                               // ValidationRequired question
2002    void *DNSSECAuthInfo;
2003    DNSSECAuthInfoFreeCallback *DAIFreeCallback;
2004
2005    // Wide Area fields. These are used internally by the uDNS core (Unicast)
2006    UDPSocket            *LocalSocket;
2007
2008    // |-> DNS Configuration related fields used in uDNS (Subset of Wide Area/Unicast fields)
2009    DNSServer            *qDNSServer;       // Caching server for this query (in the absence of an SRV saying otherwise)
2010    mDNSOpaque128 validDNSServers;          // Valid DNSServers for this question
2011    mDNSu16 noServerResponse;               // At least one server did not respond.
2012    mDNSu16 triedAllServersOnce;            // Tried all DNS servers once
2013    mDNSu8 unansweredQueries;               // The number of unanswered queries to this server
2014    AllowExpiredState allowExpired;         // Allow expired answers state (see enum AllowExpired_None, etc. above)
2015
2016    ZoneData             *nta;              // Used for getting zone data for private or LLQ query
2017    mDNSAddr servAddr;                      // Address and port learned from _dns-llq, _dns-llq-tls or _dns-query-tls SRV query
2018    mDNSIPPort servPort;
2019    struct tcpInfo_t *tcp;
2020    mDNSIPPort tcpSrcPort;                  // Local Port TCP packet received on;need this as tcp struct is disposed
2021                                            // by tcpCallback before calling into mDNSCoreReceive
2022    mDNSu8 NoAnswer;                        // Set if we want to suppress answers until tunnel setup has completed
2023    mDNSu8 Restart;                         // This question should be restarted soon
2024
2025    // LLQ-specific fields. These fields are only meaningful when LongLived flag is set
2026    LLQ_State state;
2027    mDNSu32 ReqLease;                       // seconds (relative)
2028    mDNSs32 expire;                         // ticks (absolute)
2029    mDNSs16 ntries;                         // for UDP: the number of packets sent for this LLQ state
2030                                            // for TCP: there is some ambiguity in the use of this variable, but in general, it is
2031                                            //          the number of TCP/TLS connection attempts for this LLQ state, or
2032                                            //          the number of packets sent for this TCP/TLS connection
2033
2034    // DNS Push Notification fields. These fields are only meaningful when LongLived flag is set
2035    DNSPush_State dnsPushState;             // The state of the DNS push notification negotiation
2036    mDNSAddr      dnsPushServerAddr;        // Address of the system acting as the DNS Push Server
2037    mDNSIPPort    dnsPushServerPort;        // Port on which the DNS Push Server is being advertised.
2038
2039    mDNSOpaque64 id;
2040
2041    // DNS Proxy fields
2042    mDNSOpaque16 responseFlags;             // Temporary place holder for the error we get back from the DNS server
2043                                            // till we populate in the cache
2044    mDNSBool     DisallowPID;               // Is the query allowed for the "PID" that we are sending on behalf of ?
2045    mDNSs32      ServiceID;                 // Service identifier to match against the DNS server
2046
2047    // Client API fields: The client must set up these fields *before* calling mDNS_StartQuery()
2048    mDNSInterfaceID InterfaceID;            // Non-zero if you want to issue queries only on a single specific IP interface
2049    mDNSu32  flags;                         // flags from original DNSService*() API request.
2050    mDNSAddr Target;                        // Non-zero if you want to direct queries to a specific unicast target address
2051    mDNSIPPort TargetPort;                  // Must be set if Target is set
2052    mDNSOpaque16 TargetQID;                 // Must be set if Target is set
2053    domainname qname;
2054    domainname firstExpiredQname;           // first expired qname in request chain
2055    mDNSu16 qtype;
2056    mDNSu16 qclass;
2057    mDNSBool LongLived;                     // Set by client for calls to mDNS_StartQuery to indicate LLQs to unicast layer.
2058    mDNSBool ExpectUnique;                  // Set by client if it's expecting unique RR(s) for this question, not shared RRs
2059    mDNSBool ForceMCast;                    // Set by client to force mDNS query, even for apparently uDNS names
2060    mDNSBool ReturnIntermed;                // Set by client to request callbacks for intermediate CNAME/NXDOMAIN results
2061    mDNSBool SuppressUnusable;              // Set by client to suppress unusable queries to be sent on the wire
2062    mDNSu8 RetryWithSearchDomains;          // Retry with search domains if there is no entry in the cache or AuthRecords
2063    mDNSu8 TimeoutQuestion;                 // Timeout this question if there is no reply in configured time
2064    mDNSu8 WakeOnResolve;                   // Send wakeup on resolve
2065    mDNSu8 UseBackgroundTrafficClass;       // Set by client to use background traffic class for request
2066    mDNSs8 SearchListIndex;                 // Index into SearchList; Used by the client layer but not touched by core
2067    mDNSs8 AppendSearchDomains;             // Search domains can be appended for this query
2068    mDNSs8 AppendLocalSearchDomains;        // Search domains ending in .local can be appended for this query
2069    mDNSu8 ValidationRequired;              // Requires DNSSEC validation.
2070    mDNSu8 ProxyQuestion;                   // Proxy Question
2071    mDNSu8 ProxyDNSSECOK;                   // Proxy Question with EDNS0 DNSSEC OK bit set
2072    mDNSs32 pid;                            // Process ID of the client that is requesting the question
2073    mDNSu8  uuid[UUID_SIZE];                // Unique ID of the client that is requesting the question (valid only if pid is zero)
2074    mDNSu32 euid;                           // Effective User Id of the client that is requesting the question
2075    domainname           *qnameOrig;        // Copy of the original question name if it is not fully qualified
2076    mDNSQuestionCallback *QuestionCallback;
2077    void                 *QuestionContext;
2078#if AWD_METRICS
2079    uDNSMetrics metrics;                    // Data used for collecting unicast DNS query metrics.
2080#endif
2081#if USE_DNS64
2082    DNS64 dns64;                            // DNS64 state for performing IPv6 address synthesis on networks with NAT64.
2083#endif
2084};
2085
2086typedef enum { ZoneServiceUpdate, ZoneServiceQuery, ZoneServiceLLQ, ZoneServiceDNSPush } ZoneService;
2087
2088typedef void ZoneDataCallback (mDNS *const m, mStatus err, const ZoneData *result);
2089
2090struct ZoneData_struct
2091{
2092    domainname ChildName;               // Name for which we're trying to find the responsible server
2093    ZoneService ZoneService;            // Which service we're seeking for this zone (update, query, or LLQ)
2094    domainname       *CurrentSOA;       // Points to somewhere within ChildName
2095    domainname ZoneName;                // Discovered result: Left-hand-side of SOA record
2096    mDNSu16 ZoneClass;                  // Discovered result: DNS Class from SOA record
2097    domainname Host;                    // Discovered result: Target host from SRV record
2098    mDNSIPPort Port;                    // Discovered result: Update port, query port, or LLQ port from SRV record
2099    mDNSAddr Addr;                      // Discovered result: Address of Target host from SRV record
2100    mDNSBool ZonePrivate;               // Discovered result: Does zone require encrypted queries?
2101    ZoneDataCallback *ZoneDataCallback; // Caller-specified function to be called upon completion
2102    void             *ZoneDataContext;
2103    DNSQuestion question;               // Storage for any active question
2104};
2105
2106extern ZoneData *StartGetZoneData(mDNS *const m, const domainname *const name, const ZoneService target, ZoneDataCallback callback, void *callbackInfo);
2107extern void CancelGetZoneData(mDNS *const m, ZoneData *nta);
2108extern mDNSBool IsGetZoneDataQuestion(DNSQuestion *q);
2109
2110typedef struct DNameListElem
2111{
2112    struct DNameListElem *next;
2113    mDNSu32 uid;
2114    domainname name;
2115} DNameListElem;
2116
2117#if APPLE_OSX_mDNSResponder
2118// Different states that we go through locating the peer
2119#define TC_STATE_AAAA_PEER          0x000000001     /* Peer's BTMM IPv6 address */
2120#define TC_STATE_AAAA_PEER_RELAY    0x000000002     /* Peer's IPv6 Relay address */
2121#define TC_STATE_SRV_PEER           0x000000003     /* Peer's SRV Record corresponding to IPv4 address */
2122#define TC_STATE_ADDR_PEER          0x000000004     /* Peer's IPv4 address */
2123
2124typedef struct ClientTunnel
2125{
2126    struct ClientTunnel *next;
2127    domainname dstname;
2128    mDNSBool MarkedForDeletion;
2129    mDNSv6Addr loc_inner;
2130    mDNSv4Addr loc_outer;
2131    mDNSv6Addr loc_outer6;
2132    mDNSv6Addr rmt_inner;
2133    mDNSv4Addr rmt_outer;
2134    mDNSv6Addr rmt_outer6;
2135    mDNSIPPort rmt_outer_port;
2136    mDNSu16 tc_state;
2137    DNSQuestion q;
2138} ClientTunnel;
2139#endif
2140
2141// ***************************************************************************
2142#if 0
2143#pragma mark -
2144#pragma mark - NetworkInterfaceInfo_struct
2145#endif
2146
2147typedef struct NetworkInterfaceInfo_struct NetworkInterfaceInfo;
2148
2149// A NetworkInterfaceInfo_struct serves two purposes:
2150// 1. It holds the address, PTR and HINFO records to advertise a given IP address on a given physical interface
2151// 2. It tells mDNSCore which physical interfaces are available; each physical interface has its own unique InterfaceID.
2152//    Since there may be multiple IP addresses on a single physical interface,
2153//    there may be multiple NetworkInterfaceInfo_structs with the same InterfaceID.
2154//    In this case, to avoid sending the same packet n times, when there's more than one
2155//    struct with the same InterfaceID, mDNSCore picks one member of the set to be the
2156//    active representative of the set; all others have the 'InterfaceActive' flag unset.
2157
2158struct NetworkInterfaceInfo_struct
2159{
2160    // Internal state fields. These are used internally by mDNSCore; the client layer needn't be concerned with them.
2161    NetworkInterfaceInfo *next;
2162
2163    mDNSu8 InterfaceActive;             // Set if interface is sending & receiving packets (see comment above)
2164    mDNSu8 IPv4Available;               // If InterfaceActive, set if v4 available on this InterfaceID
2165    mDNSu8 IPv6Available;               // If InterfaceActive, set if v6 available on this InterfaceID
2166
2167    DNSQuestion NetWakeBrowse;
2168    DNSQuestion NetWakeResolve[3];      // For fault-tolerance, we try up to three Sleep Proxies
2169    mDNSAddr SPSAddr[3];
2170    mDNSIPPort SPSPort[3];
2171    mDNSs32 NextSPSAttempt;             // -1 if we're not currently attempting to register with any Sleep Proxy
2172    mDNSs32 NextSPSAttemptTime;
2173
2174    // Standard AuthRecords that every Responder host should have (one per active IP address)
2175    AuthRecord RR_A;                    // 'A' or 'AAAA' (address) record for our ".local" name
2176    AuthRecord RR_PTR;                  // PTR (reverse lookup) record
2177    AuthRecord RR_HINFO;
2178
2179    // Client API fields: The client must set up these fields *before* calling mDNS_RegisterInterface()
2180    mDNSInterfaceID InterfaceID;        // Identifies physical interface; MUST NOT be 0, -1, or -2
2181    mDNSAddr ip;                        // The IPv4 or IPv6 address to advertise
2182    mDNSAddr mask;
2183    mDNSEthAddr MAC;
2184    char ifname[64];                    // Windows uses a GUID string for the interface name, which doesn't fit in 16 bytes
2185    mDNSu8 Advertise;                   // False if you are only searching on this interface
2186    mDNSu8 McastTxRx;                   // Send/Receive multicast on this { InterfaceID, address family } ?
2187    mDNSu8 NetWake;                     // Set if Wake-On-Magic-Packet is enabled on this interface
2188    mDNSu8 Loopback;                    // Set if this is the loopback interface
2189    mDNSu8 IgnoreIPv4LL;                // Set if IPv4 Link-Local addresses have to be ignored.
2190    mDNSu8 SendGoodbyes;                // Send goodbyes on this interface while sleeping
2191    mDNSBool DirectLink;                // a direct link, indicating we can skip the probe for
2192                                        // address records
2193    mDNSBool SupportsUnicastMDNSResponse;  // Indicates that the interface supports unicast responses
2194                                        // to Bonjour queries.  Generally true for an interface.
2195};
2196
2197#define SLE_DELETE                      0x00000001
2198#define SLE_WAB_BROWSE_QUERY_STARTED    0x00000002
2199#define SLE_WAB_LBROWSE_QUERY_STARTED   0x00000004
2200#define SLE_WAB_REG_QUERY_STARTED       0x00000008
2201
2202typedef struct SearchListElem
2203{
2204    struct SearchListElem *next;
2205    domainname domain;
2206    int flag;
2207    mDNSInterfaceID InterfaceID;
2208    DNSQuestion BrowseQ;
2209    DNSQuestion DefBrowseQ;
2210    DNSQuestion AutomaticBrowseQ;
2211    DNSQuestion RegisterQ;
2212    DNSQuestion DefRegisterQ;
2213    int numCfAnswers;
2214    ARListElem *AuthRecs;
2215} SearchListElem;
2216
2217// For domain enumeration and automatic browsing
2218// This is the user's DNS search list.
2219// In each of these domains we search for our special pointer records (lb._dns-sd._udp.<domain>, etc.)
2220// to discover recommended domains for domain enumeration (browse, default browse, registration,
2221// default registration) and possibly one or more recommended automatic browsing domains.
2222extern SearchListElem *SearchList;      // This really ought to be part of mDNS_struct -- SC
2223
2224// ***************************************************************************
2225#if 0
2226#pragma mark -
2227#pragma mark - Main mDNS object, used to hold all the mDNS state
2228#endif
2229
2230typedef void mDNSCallback (mDNS *const m, mStatus result);
2231
2232#ifndef CACHE_HASH_SLOTS
2233#define CACHE_HASH_SLOTS 499
2234#endif
2235
2236enum
2237{
2238    SleepState_Awake = 0,
2239    SleepState_Transferring = 1,
2240    SleepState_Sleeping = 2
2241};
2242
2243typedef enum
2244{
2245    kStatsActionIncrement,
2246    kStatsActionDecrement,
2247    kStatsActionClear,
2248    kStatsActionSet
2249} DNSSECStatsAction;
2250
2251typedef enum
2252{
2253    kStatsTypeMemoryUsage,
2254    kStatsTypeLatency,
2255    kStatsTypeExtraPackets,
2256    kStatsTypeStatus,
2257    kStatsTypeProbe,
2258    kStatsTypeMsgSize
2259} DNSSECStatsType;
2260
2261typedef struct
2262{
2263    mDNSu32 TotalMemUsed;
2264    mDNSu32 Latency0;           // 0 to 4 ms
2265    mDNSu32 Latency5;           // 5 to  9 ms
2266    mDNSu32 Latency10;          // 10 to 19 ms
2267    mDNSu32 Latency20;          // 20 to 49 ms
2268    mDNSu32 Latency50;          // 50 to 99 ms
2269    mDNSu32 Latency100;         // >= 100 ms
2270    mDNSu32 ExtraPackets0;      // 0 to 2 packets
2271    mDNSu32 ExtraPackets3;      // 3 to 6 packets
2272    mDNSu32 ExtraPackets7;      // 7 to 9 packets
2273    mDNSu32 ExtraPackets10;     // >= 10 packets
2274    mDNSu32 SecureStatus;
2275    mDNSu32 InsecureStatus;
2276    mDNSu32 IndeterminateStatus;
2277    mDNSu32 BogusStatus;
2278    mDNSu32 NoResponseStatus;
2279    mDNSu32 NumProbesSent;      // Number of probes sent
2280    mDNSu32 MsgSize0;           // DNSSEC message size <= 1024
2281    mDNSu32 MsgSize1;           // DNSSEC message size <= 2048
2282    mDNSu32 MsgSize2;           // DNSSEC message size > 2048
2283} DNSSECStatistics;
2284
2285typedef struct
2286{
2287    mDNSu32 NameConflicts;                  // Normal Name conflicts
2288    mDNSu32 KnownUniqueNameConflicts;       // Name Conflicts for KnownUnique Records
2289    mDNSu32 DupQuerySuppressions;           // Duplicate query suppressions
2290    mDNSu32 KnownAnswerSuppressions;        // Known Answer suppressions
2291    mDNSu32 KnownAnswerMultiplePkts;        // Known Answer in queries spannign multiple packets
2292    mDNSu32 PoofCacheDeletions;             // Number of times the cache was deleted due to POOF
2293    mDNSu32 UnicastBitInQueries;            // Queries with QU bit set
2294    mDNSu32 NormalQueries;                  // Queries with QU bit not set
2295    mDNSu32 MatchingAnswersForQueries;      // Queries for which we had a response
2296    mDNSu32 UnicastResponses;               // Unicast responses to queries
2297    mDNSu32 MulticastResponses;             // Multicast responses to queries
2298    mDNSu32 UnicastDemotedToMulticast;      // Number of times unicast demoted to multicast
2299    mDNSu32 Sleeps;                         // Total sleeps
2300    mDNSu32 Wakes;                          // Total wakes
2301    mDNSu32 InterfaceUp;                    // Total Interface UP events
2302    mDNSu32 InterfaceUpFlap;                // Total Interface UP events with flaps
2303    mDNSu32 InterfaceDown;                  // Total Interface Down events
2304    mDNSu32 InterfaceDownFlap;              // Total Interface Down events with flaps
2305    mDNSu32 CacheRefreshQueries;            // Number of queries that we sent for refreshing cache
2306    mDNSu32 CacheRefreshed;                 // Number of times the cache was refreshed due to a response
2307    mDNSu32 WakeOnResolves;                 // Number of times we did a wake on resolve
2308} mDNSStatistics;
2309
2310extern void LogMDNSStatistics(mDNS *const m);
2311
2312typedef struct mDNS_DNSPushNotificationServer DNSPushNotificationServer;
2313typedef struct mDNS_DNSPushNotificationZone   DNSPushNotificationZone;
2314
2315struct mDNS_DNSPushNotificationServer
2316{
2317    mDNSAddr   serverAddr;        // Server Address
2318    tcpInfo_t *connection;        // TCP Connection pointer
2319    mDNSu32    numberOfQuestions; // Number of questions for this server
2320    DNSPushNotificationServer *next;
2321} ;
2322
2323struct mDNS_DNSPushNotificationZone
2324{
2325    domainname zoneName;
2326    DNSPushNotificationServer *servers; // DNS Push Notification Servers for this zone
2327    mDNSu32 numberOfQuestions;          // Number of questions for this zone
2328    DNSPushNotificationZone *next;
2329} ;
2330
2331
2332// Time constant (~= 260 hours ~= 10 days and 21 hours) used to set
2333// various time values to a point well into the future.
2334#define FutureTime   0x38000000
2335
2336struct mDNS_struct
2337{
2338    // Internal state fields. These hold the main internal state of mDNSCore;
2339    // the client layer needn't be concerned with them.
2340    // No fields need to be set up by the client prior to calling mDNS_Init();
2341    // all required data is passed as parameters to that function.
2342
2343    mDNS_PlatformSupport *p;            // Pointer to platform-specific data of indeterminite size
2344    mDNSs32 NetworkChanged;
2345    mDNSBool CanReceiveUnicastOn5353;
2346    mDNSBool AdvertiseLocalAddresses;
2347    mDNSBool DivertMulticastAdvertisements; // from interfaces that do not advertise local addresses to local-only
2348    mStatus mDNSPlatformStatus;
2349    mDNSIPPort UnicastPort4;
2350    mDNSIPPort UnicastPort6;
2351    mDNSEthAddr PrimaryMAC;             // Used as unique host ID
2352    mDNSCallback *MainCallback;
2353    void         *MainContext;
2354
2355    // For debugging: To catch and report locking failures
2356    mDNSu32 mDNS_busy;                  // Incremented between mDNS_Lock/mDNS_Unlock section
2357    mDNSu32 mDNS_reentrancy;            // Incremented when calling a client callback
2358    mDNSu8 lock_rrcache;                // For debugging: Set at times when these lists may not be modified
2359    mDNSu8 lock_Questions;
2360    mDNSu8 lock_Records;
2361#ifndef MaxMsg
2362    #define MaxMsg 512
2363#endif
2364    char MsgBuffer[MaxMsg];             // Temp storage used while building error log messages
2365
2366    // Task Scheduling variables
2367    mDNSs32 timenow_adjust;             // Correction applied if we ever discover time went backwards
2368    mDNSs32 timenow;                    // The time that this particular activation of the mDNS code started
2369    mDNSs32 timenow_last;               // The time the last time we ran
2370    mDNSs32 NextScheduledEvent;         // Derived from values below
2371    mDNSs32 ShutdownTime;               // Set when we're shutting down; allows us to skip some unnecessary steps
2372    mDNSs32 SuppressSending;            // Don't send local-link mDNS packets during this time
2373    mDNSs32 NextCacheCheck;             // Next time to refresh cache record before it expires
2374    mDNSs32 NextScheduledQuery;         // Next time to send query in its exponential backoff sequence
2375    mDNSs32 NextScheduledProbe;         // Next time to probe for new authoritative record
2376    mDNSs32 NextScheduledResponse;      // Next time to send authoritative record(s) in responses
2377    mDNSs32 NextScheduledNATOp;         // Next time to send NAT-traversal packets
2378    mDNSs32 NextScheduledSPS;           // Next time to purge expiring Sleep Proxy records
2379    mDNSs32 NextScheduledKA;            // Next time to send Keepalive packets (SPS)
2380#if BONJOUR_ON_DEMAND
2381    mDNSs32 NextBonjourDisableTime;     // Next time to leave multicast group if Bonjour on Demand is enabled
2382    mDNSu8 BonjourEnabled;              // Non zero if Bonjour is currently enabled by the Bonjour on Demand logic
2383#endif // BONJOUR_ON_DEMAND
2384    mDNSs32 DelayConflictProcessing;    // To prevent spurious confilcts due to stale packets on the wire/air.
2385    mDNSs32 RandomQueryDelay;           // For de-synchronization of query packets on the wire
2386    mDNSu32 RandomReconfirmDelay;       // For de-synchronization of reconfirmation queries on the wire
2387    mDNSs32 PktNum;                     // Unique sequence number assigned to each received packet
2388    mDNSs32 MPktNum;                    // Unique sequence number assigned to each received Multicast packet
2389    mDNSu8 LocalRemoveEvents;           // Set if we may need to deliver remove events for local-only questions and/or local-only records
2390    mDNSu8 SleepState;                  // Set if we're sleeping
2391    mDNSu8 SleepSeqNum;                 // "Epoch number" of our current period of wakefulness
2392    mDNSu8 SystemWakeOnLANEnabled;      // Set if we want to register with a Sleep Proxy before going to sleep
2393    mDNSu8 SentSleepProxyRegistration;  // Set if we registered (or tried to register) with a Sleep Proxy
2394    mDNSu8 SystemSleepOnlyIfWakeOnLAN;  // Set if we may only sleep if we managed to register with a Sleep Proxy
2395    mDNSs32 AnnounceOwner;              // After waking from sleep, include OWNER option in packets until this time
2396    mDNSs32 DelaySleep;                 // To inhibit re-sleeping too quickly right after wake
2397    mDNSs32 SleepLimit;                 // Time window to allow deregistrations, etc.,
2398                                        // during which underying platform layer should inhibit system sleep
2399    mDNSs32 TimeSlept;                  // Time we went to sleep.
2400
2401    mDNSs32 UnicastPacketsSent;         // Number of unicast packets sent.
2402    mDNSs32 MulticastPacketsSent;       // Number of multicast packets sent.
2403    mDNSs32 RemoteSubnet;               // Multicast packets received from outside our subnet.
2404
2405    mDNSs32 NextScheduledSPRetry;       // Time next sleep proxy registration action is required.
2406                                        // Only valid if SleepLimit is nonzero and DelaySleep is zero.
2407
2408    mDNSs32 NextScheduledStopTime;      // Next time to stop a question
2409
2410    mDNSs32 NextBLEServiceTime;         // Next time to call the BLE discovery management layer.  Non zero when active.
2411
2412    // These fields only required for mDNS Searcher...
2413    DNSQuestion *Questions;             // List of all registered questions, active and inactive
2414    DNSQuestion *NewQuestions;          // Fresh questions not yet answered from cache
2415    DNSQuestion *CurrentQuestion;       // Next question about to be examined in AnswerLocalQuestions()
2416    DNSQuestion *LocalOnlyQuestions;    // Questions with InterfaceID set to mDNSInterface_LocalOnly or mDNSInterface_P2P
2417    DNSQuestion *NewLocalOnlyQuestions; // Fresh local-only or P2P questions not yet answered
2418    DNSQuestion *RestartQuestion;       // Questions that are being restarted (stop followed by start)
2419    DNSQuestion *ValidationQuestion;    // Questions that are being validated (dnssec)
2420    mDNSu32 rrcache_size;               // Total number of available cache entries
2421    mDNSu32 rrcache_totalused;          // Number of cache entries currently occupied
2422    mDNSu32 rrcache_totalused_unicast;  // Number of cache entries currently occupied by unicast
2423    mDNSu32 rrcache_active;             // Number of cache entries currently occupied by records that answer active questions
2424    mDNSu32 rrcache_report;
2425    CacheEntity *rrcache_free;
2426    CacheGroup *rrcache_hash[CACHE_HASH_SLOTS];
2427    mDNSs32 rrcache_nextcheck[CACHE_HASH_SLOTS];
2428
2429    AuthHash rrauth;
2430
2431    // Fields below only required for mDNS Responder...
2432    domainlabel nicelabel;              // Rich text label encoded using canonically precomposed UTF-8
2433    domainlabel hostlabel;              // Conforms to RFC 1034 "letter-digit-hyphen" ARPANET host name rules
2434    domainname MulticastHostname;       // Fully Qualified "dot-local" Host Name, e.g. "Foo.local."
2435    UTF8str255 HIHardware;
2436    UTF8str255 HISoftware;
2437    AuthRecord DeviceInfo;
2438    AuthRecord *ResourceRecords;
2439    AuthRecord *DuplicateRecords;       // Records currently 'on hold' because they are duplicates of existing records
2440    AuthRecord *NewLocalRecords;        // Fresh AuthRecords (public) not yet delivered to our local-only questions
2441    AuthRecord *CurrentRecord;          // Next AuthRecord about to be examined
2442    mDNSBool NewLocalOnlyRecords;       // Fresh AuthRecords (local only) not yet delivered to our local questions
2443    NetworkInterfaceInfo *HostInterfaces;
2444    mDNSs32 ProbeFailTime;
2445    mDNSu32 NumFailedProbes;
2446    mDNSs32 SuppressProbes;
2447    Platform_t mDNS_plat;               // Why is this here in the ���only required for mDNS Responder��� section? -- SC
2448
2449    // Unicast-specific data
2450    mDNSs32 NextuDNSEvent;                  // uDNS next event
2451    mDNSs32 NextSRVUpdate;                  // Time to perform delayed update
2452
2453    DNSServer        *DNSServers;           // list of DNS servers
2454    McastResolver    *McastResolvers;       // list of Mcast Resolvers
2455
2456    mDNSAddr Router;
2457    mDNSAddr AdvertisedV4;                  // IPv4 address pointed to by hostname
2458    mDNSAddr AdvertisedV6;                  // IPv6 address pointed to by hostname
2459
2460    DomainAuthInfo   *AuthInfoList;         // list of domains requiring authentication for updates
2461
2462    DNSQuestion ReverseMap;                 // Reverse-map query to find static hostname for service target
2463    DNSQuestion AutomaticBrowseDomainQ;
2464    domainname StaticHostname;              // Current answer to reverse-map query
2465    domainname FQDN;
2466    HostnameInfo     *Hostnames;            // List of registered hostnames + hostname metadata
2467    NATTraversalInfo AutoTunnelNAT;         // Shared between all AutoTunnel DomainAuthInfo structs
2468    mDNSv6Addr AutoTunnelRelayAddr;
2469
2470    mDNSu32 WABBrowseQueriesCount;          // Number of WAB Browse domain enumeration queries (b, db) callers
2471    mDNSu32 WABLBrowseQueriesCount;         // Number of legacy WAB Browse domain enumeration queries (lb) callers
2472    mDNSu32 WABRegQueriesCount;             // Number of WAB Registration domain enumeration queries (r, dr) callers
2473    mDNSu8 SearchDomainsHash[MD5_LEN];
2474
2475    // NAT-Traversal fields
2476    NATTraversalInfo LLQNAT;                    // Single shared NAT Traversal to receive inbound LLQ notifications
2477    NATTraversalInfo *NATTraversals;
2478    NATTraversalInfo *CurrentNATTraversal;
2479    mDNSs32 retryIntervalGetAddr;               // delta between time sent and retry for NAT-PMP & UPnP/IGD external address request
2480    mDNSs32 retryGetAddr;                       // absolute time when we retry for NAT-PMP & UPnP/IGD external address request
2481    mDNSv4Addr ExtAddress;                      // the external address discovered via NAT-PMP or UPnP/IGD
2482    mDNSu32 PCPNonce[3];                        // the nonce if using PCP
2483
2484    UDPSocket        *NATMcastRecvskt;          // For receiving PCP & NAT-PMP announcement multicasts from router on port 5350
2485    mDNSu32 LastNATupseconds;                   // NAT engine uptime in seconds, from most recent NAT packet
2486    mDNSs32 LastNATReplyLocalTime;              // Local time in ticks when most recent NAT packet was received
2487    mDNSu16 LastNATMapResultCode;               // Most recent error code for mappings
2488
2489    tcpLNTInfo tcpAddrInfo;                     // legacy NAT traversal TCP connection info for external address
2490    tcpLNTInfo tcpDeviceInfo;                   // legacy NAT traversal TCP connection info for device info
2491    tcpLNTInfo       *tcpInfoUnmapList;         // list of pending unmap requests
2492    mDNSInterfaceID UPnPInterfaceID;
2493    UDPSocket        *SSDPSocket;               // For SSDP request/response
2494    mDNSBool SSDPWANPPPConnection;              // whether we should send the SSDP query for WANIPConnection or WANPPPConnection
2495    mDNSIPPort UPnPRouterPort;                  // port we send discovery messages to
2496    mDNSIPPort UPnPSOAPPort;                    // port we send SOAP messages to
2497    char             *UPnPRouterURL;            // router's URL string
2498    mDNSBool UPnPWANPPPConnection;              // whether we're using WANIPConnection or WANPPPConnection
2499    char             *UPnPSOAPURL;              // router's SOAP control URL string
2500    char             *UPnPRouterAddressString;  // holds both the router's address and port
2501    char             *UPnPSOAPAddressString;    // holds both address and port for SOAP messages
2502
2503    // DNS Push Notification fields
2504    DNSPushNotificationServer *DNSPushServers;  // DNS Push Notification Servers
2505    DNSPushNotificationZone   *DNSPushZones;
2506
2507    // Sleep Proxy client fields
2508    AuthRecord *SPSRRSet;                       // To help the client keep track of the records registered with the sleep proxy
2509
2510    // Sleep Proxy Server fields
2511    mDNSu8 SPSType;                             // 0 = off, 10-99 encodes desirability metric
2512    mDNSu8 SPSPortability;                      // 10-99
2513    mDNSu8 SPSMarginalPower;                    // 10-99
2514    mDNSu8 SPSTotalPower;                       // 10-99
2515    mDNSu8 SPSFeatureFlags;                     // Features supported. Currently 1 = TCP KeepAlive supported.
2516    mDNSu8 SPSState;                            // 0 = off, 1 = running, 2 = shutting down, 3 = suspended during sleep
2517    mDNSInterfaceID SPSProxyListChanged;
2518    UDPSocket        *SPSSocket;
2519#ifndef SPC_DISABLED
2520    ServiceRecordSet SPSRecords;
2521#endif
2522    mDNSQuestionCallback *SPSBrowseCallback;    // So the platform layer can do something useful with SPS browse results
2523    int ProxyRecords;                           // Total number of records we're holding as proxy
2524    #define           MAX_PROXY_RECORDS 10000   /* DOS protection: 400 machines at 25 records each */
2525
2526#if APPLE_OSX_mDNSResponder
2527    ClientTunnel     *TunnelClients;
2528    void            *WCF;
2529#endif
2530    // DNS Proxy fields
2531    mDNSu32 dp_ipintf[MaxIp];                   // input interface index list from the DNS Proxy Client
2532    mDNSu32 dp_opintf;                          // output interface index from the DNS Proxy Client
2533
2534    TrustAnchor     *TrustAnchors;
2535    int             notifyToken;
2536    int             uds_listener_skt;           // Listening socket for incoming UDS clients. This should not be here -- it's private to uds_daemon.c and nothing to do with mDNSCore -- SC
2537    mDNSu32         AutoTargetServices;         // # of services that have AutoTarget set
2538
2539#if BONJOUR_ON_DEMAND
2540    // Counters used in Bonjour on Demand logic.
2541    mDNSu32         NumAllInterfaceRecords;     // Right now we count *all* multicast records here. Later we may want to change to count interface-specific records separately. (This count includes records on the DuplicateRecords list too.)
2542    mDNSu32         NumAllInterfaceQuestions;   // Right now we count *all* multicast questions here. Later we may want to change to count interface-specific questions separately.
2543#endif // BONJOUR_ON_DEMAND
2544
2545    DNSSECStatistics DNSSECStats;
2546    mDNSStatistics   mDNSStats;
2547
2548    // Fixed storage, to avoid creating large objects on the stack
2549    // The imsg is declared as a union with a pointer type to enforce CPU-appropriate alignment
2550    union { DNSMessage m; void *p; } imsg;  // Incoming message received from wire
2551    DNSMessage omsg;                        // Outgoing message we're building
2552    LargeCacheRecord rec;                   // Resource Record extracted from received message
2553};
2554
2555#define FORALL_CACHERECORDS(SLOT,CG,CR)                           \
2556    for ((SLOT) = 0; (SLOT) < CACHE_HASH_SLOTS; (SLOT)++)         \
2557        for ((CG)=m->rrcache_hash[(SLOT)]; (CG); (CG)=(CG)->next) \
2558            for ((CR) = (CG)->members; (CR); (CR)=(CR)->next)
2559
2560// ***************************************************************************
2561#if 0
2562#pragma mark -
2563#pragma mark - Useful Static Constants
2564#endif
2565
2566extern const mDNSInterfaceID mDNSInterface_Any;             // Zero
2567extern const mDNSInterfaceID mDNSInterface_LocalOnly;       // Special value
2568extern const mDNSInterfaceID mDNSInterface_Unicast;         // Special value
2569extern const mDNSInterfaceID mDNSInterfaceMark;             // Special value
2570extern const mDNSInterfaceID mDNSInterface_P2P;             // Special value
2571extern const mDNSInterfaceID uDNSInterfaceMark;             // Special value
2572extern const mDNSInterfaceID mDNSInterface_BLE;             // Special value
2573
2574#define LocalOnlyOrP2PInterface(INTERFACE)  ((INTERFACE == mDNSInterface_LocalOnly) || (INTERFACE == mDNSInterface_P2P) || (INTERFACE == mDNSInterface_BLE))
2575
2576extern const mDNSIPPort DiscardPort;
2577extern const mDNSIPPort SSHPort;
2578extern const mDNSIPPort UnicastDNSPort;
2579extern const mDNSIPPort SSDPPort;
2580extern const mDNSIPPort IPSECPort;
2581extern const mDNSIPPort NSIPCPort;
2582extern const mDNSIPPort NATPMPAnnouncementPort;
2583extern const mDNSIPPort NATPMPPort;
2584extern const mDNSIPPort DNSEXTPort;
2585extern const mDNSIPPort MulticastDNSPort;
2586extern const mDNSIPPort LoopbackIPCPort;
2587extern const mDNSIPPort PrivateDNSPort;
2588
2589extern const OwnerOptData zeroOwner;
2590
2591extern const mDNSIPPort zeroIPPort;
2592extern const mDNSv4Addr zerov4Addr;
2593extern const mDNSv6Addr zerov6Addr;
2594extern const mDNSEthAddr zeroEthAddr;
2595extern const mDNSv4Addr onesIPv4Addr;
2596extern const mDNSv6Addr onesIPv6Addr;
2597extern const mDNSEthAddr onesEthAddr;
2598extern const mDNSAddr zeroAddr;
2599
2600extern const mDNSv4Addr AllDNSAdminGroup;
2601extern const mDNSv4Addr AllHosts_v4;
2602extern const mDNSv6Addr AllHosts_v6;
2603extern const mDNSv6Addr NDP_prefix;
2604extern const mDNSEthAddr AllHosts_v6_Eth;
2605extern const mDNSAddr AllDNSLinkGroup_v4;
2606extern const mDNSAddr AllDNSLinkGroup_v6;
2607
2608extern const mDNSOpaque16 zeroID;
2609extern const mDNSOpaque16 onesID;
2610extern const mDNSOpaque16 QueryFlags;
2611extern const mDNSOpaque16 uQueryFlags;
2612extern const mDNSOpaque16 DNSSecQFlags;
2613extern const mDNSOpaque16 ResponseFlags;
2614extern const mDNSOpaque16 UpdateReqFlags;
2615extern const mDNSOpaque16 UpdateRespFlags;
2616extern const mDNSOpaque16 SubscribeFlags;
2617extern const mDNSOpaque16 UnSubscribeFlags;
2618
2619extern const mDNSOpaque64 zeroOpaque64;
2620extern const mDNSOpaque128 zeroOpaque128;
2621
2622extern mDNSBool StrictUnicastOrdering;
2623extern mDNSu8 NumUnicastDNSServers;
2624#if APPLE_OSX_mDNSResponder
2625extern mDNSu8 NumUnreachableDNSServers;
2626#endif
2627
2628#define localdomain           (*(const domainname *)"\x5" "local")
2629#define DeviceInfoName        (*(const domainname *)"\xC" "_device-info" "\x4" "_tcp")
2630#define LocalDeviceInfoName   (*(const domainname *)"\xC" "_device-info" "\x4" "_tcp" "\x5" "local")
2631#define SleepProxyServiceType (*(const domainname *)"\xC" "_sleep-proxy" "\x4" "_udp")
2632
2633// ***************************************************************************
2634#if 0
2635#pragma mark -
2636#pragma mark - Inline functions
2637#endif
2638
2639#if (defined(_MSC_VER))
2640    #define mDNSinline static __inline
2641#elif ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9)))
2642    #define mDNSinline static inline
2643#else
2644    #define mDNSinline static inline
2645#endif
2646
2647// If we're not doing inline functions, then this header needs to have the extern declarations
2648#if !defined(mDNSinline)
2649extern mDNSs32      NonZeroTime(mDNSs32 t);
2650extern mDNSu16      mDNSVal16(mDNSOpaque16 x);
2651extern mDNSOpaque16 mDNSOpaque16fromIntVal(mDNSu16 v);
2652#endif
2653
2654// If we're compiling the particular C file that instantiates our inlines, then we
2655// define "mDNSinline" (to empty string) so that we generate code in the following section
2656#if (!defined(mDNSinline) && mDNS_InstantiateInlines)
2657#define mDNSinline
2658#endif
2659
2660#ifdef mDNSinline
2661
2662mDNSinline mDNSs32 NonZeroTime(mDNSs32 t) { if (t) return(t);else return(1);}
2663
2664mDNSinline mDNSu16 mDNSVal16(mDNSOpaque16 x) { return((mDNSu16)((mDNSu16)x.b[0] <<  8 | (mDNSu16)x.b[1])); }
2665
2666mDNSinline mDNSOpaque16 mDNSOpaque16fromIntVal(mDNSu16 v)
2667{
2668    mDNSOpaque16 x;
2669    x.b[0] = (mDNSu8)(v >> 8);
2670    x.b[1] = (mDNSu8)(v & 0xFF);
2671    return(x);
2672}
2673
2674#endif
2675
2676// ***************************************************************************
2677#if 0
2678#pragma mark -
2679#pragma mark - Main Client Functions
2680#endif
2681
2682// Every client should call mDNS_Init, passing in storage for the mDNS object and the mDNS_PlatformSupport object.
2683//
2684// Clients that are only advertising services should use mDNS_Init_NoCache and mDNS_Init_ZeroCacheSize.
2685// Clients that plan to perform queries (mDNS_StartQuery, mDNS_StartBrowse, etc.)
2686// need to provide storage for the resource record cache, or the query calls will return 'mStatus_NoCache'.
2687// The rrcachestorage parameter is the address of memory for the resource record cache, and
2688// the rrcachesize parameter is the number of entries in the CacheRecord array passed in.
2689// (i.e. the size of the cache memory needs to be sizeof(CacheRecord) * rrcachesize).
2690// OS X 10.3 Panther uses an initial cache size of 64 entries, and then mDNSCore sends an
2691// mStatus_GrowCache message if it needs more.
2692//
2693// Most clients should use mDNS_Init_AdvertiseLocalAddresses. This causes mDNSCore to automatically
2694// create the correct address records for all the hosts interfaces. If you plan to advertise
2695// services being offered by the local machine, this is almost always what you want.
2696// There are two cases where you might use mDNS_Init_DontAdvertiseLocalAddresses:
2697// 1. A client-only device, that browses for services but doesn't advertise any of its own.
2698// 2. A proxy-registration service, that advertises services being offered by other machines, and takes
2699//    the appropriate steps to manually create the correct address records for those other machines.
2700// In principle, a proxy-like registration service could manually create address records for its own machine too,
2701// but this would be pointless extra effort when using mDNS_Init_AdvertiseLocalAddresses does that for you.
2702//
2703// Note that a client-only device that wishes to prohibit multicast advertisements (e.g. from
2704// higher-layer API calls) must also set DivertMulticastAdvertisements in the mDNS structure and
2705// advertise local address(es) on a loopback interface.
2706//
2707// When mDNS has finished setting up the client's callback is called
2708// A client can also spin and poll the mDNSPlatformStatus field to see when it changes from mStatus_Waiting to mStatus_NoError
2709//
2710// Call mDNS_StartExit to tidy up before exiting
2711// Because exiting may be an asynchronous process (e.g. if unicast records need to be deregistered)
2712// client layer may choose to wait until mDNS_ExitNow() returns true before calling mDNS_FinalExit().
2713//
2714// Call mDNS_Register with a completed AuthRecord object to register a resource record
2715// If the resource record type is kDNSRecordTypeUnique (or kDNSknownunique) then if a conflicting resource record is discovered,
2716// the resource record's mDNSRecordCallback will be called with error code mStatus_NameConflict. The callback should deregister
2717// the record, and may then try registering the record again after picking a new name (e.g. by automatically appending a number).
2718// Following deregistration, the RecordCallback will be called with result mStatus_MemFree to signal that it is safe to deallocate
2719// the record's storage (memory must be freed asynchronously to allow for goodbye packets and dynamic update deregistration).
2720//
2721// Call mDNS_StartQuery to initiate a query. mDNS will proceed to issue Multicast DNS query packets, and any time a response
2722// is received containing a record which matches the question, the DNSQuestion's mDNSAnswerCallback function will be called
2723// Call mDNS_StopQuery when no more answers are required
2724//
2725// Care should be taken on multi-threaded or interrupt-driven environments.
2726// The main mDNS routines call mDNSPlatformLock() on entry and mDNSPlatformUnlock() on exit;
2727// each platform layer needs to implement these appropriately for its respective platform.
2728// For example, if the support code on a particular platform implements timer callbacks at interrupt time, then
2729// mDNSPlatformLock/Unlock need to disable interrupts or do similar concurrency control to ensure that the mDNS
2730// code is not entered by an interrupt-time timer callback while in the middle of processing a client call.
2731
2732extern mStatus mDNS_Init      (mDNS *const m, mDNS_PlatformSupport *const p,
2733                               CacheEntity *rrcachestorage, mDNSu32 rrcachesize,
2734                               mDNSBool AdvertiseLocalAddresses,
2735                               mDNSCallback *Callback, void *Context);
2736// See notes above on use of NoCache/ZeroCacheSize
2737#define mDNS_Init_NoCache                     mDNSNULL
2738#define mDNS_Init_ZeroCacheSize               0
2739// See notes above on use of Advertise/DontAdvertiseLocalAddresses
2740#define mDNS_Init_AdvertiseLocalAddresses     mDNStrue
2741#define mDNS_Init_DontAdvertiseLocalAddresses mDNSfalse
2742#define mDNS_Init_NoInitCallback              mDNSNULL
2743#define mDNS_Init_NoInitCallbackContext       mDNSNULL
2744
2745extern void    mDNS_ConfigChanged(mDNS *const m);
2746extern void    mDNS_GrowCache (mDNS *const m, CacheEntity *storage, mDNSu32 numrecords);
2747extern void    mDNS_StartExit (mDNS *const m);
2748extern void    mDNS_FinalExit (mDNS *const m);
2749#define mDNS_Close(m) do { mDNS_StartExit(m); mDNS_FinalExit(m); } while(0)
2750#define mDNS_ExitNow(m, now) ((now) - (m)->ShutdownTime >= 0 || (!(m)->ResourceRecords))
2751
2752extern mDNSs32 mDNS_Execute   (mDNS *const m);
2753
2754extern mStatus mDNS_Register  (mDNS *const m, AuthRecord *const rr);
2755extern mStatus mDNS_Update    (mDNS *const m, AuthRecord *const rr, mDNSu32 newttl,
2756                               const mDNSu16 newrdlength, RData *const newrdata, mDNSRecordUpdateCallback *Callback);
2757extern mStatus mDNS_Deregister(mDNS *const m, AuthRecord *const rr);
2758
2759extern mStatus mDNS_StartQuery(mDNS *const m, DNSQuestion *const question);
2760extern mStatus mDNS_StopQuery (mDNS *const m, DNSQuestion *const question);
2761extern mStatus mDNS_StopQueryWithRemoves(mDNS *const m, DNSQuestion *const question);
2762extern mStatus mDNS_Reconfirm (mDNS *const m, CacheRecord *const cacherr);
2763extern mStatus mDNS_Reconfirm_internal(mDNS *const m, CacheRecord *const rr, mDNSu32 interval);
2764extern mStatus mDNS_ReconfirmByValue(mDNS *const m, ResourceRecord *const rr);
2765extern void    mDNS_PurgeCacheResourceRecord(mDNS *const m, CacheRecord *rr);
2766extern mDNSs32 mDNS_TimeNow(const mDNS *const m);
2767
2768extern mStatus mDNS_StartNATOperation(mDNS *const m, NATTraversalInfo *traversal);
2769extern mStatus mDNS_StopNATOperation(mDNS *const m, NATTraversalInfo *traversal);
2770extern mStatus mDNS_StopNATOperation_internal(mDNS *m, NATTraversalInfo *traversal);
2771
2772extern DomainAuthInfo *GetAuthInfoForName(mDNS *m, const domainname *const name);
2773
2774extern void    mDNS_UpdateAllowSleep(mDNS *const m);
2775
2776// ***************************************************************************
2777#if 0
2778#pragma mark -
2779#pragma mark - Platform support functions that are accessible to the client layer too
2780#endif
2781
2782extern mDNSs32 mDNSPlatformOneSecond;
2783
2784// ***************************************************************************
2785#if 0
2786#pragma mark -
2787#pragma mark - General utility and helper functions
2788#endif
2789
2790// mDNS_Dereg_normal is used for most calls to mDNS_Deregister_internal
2791// mDNS_Dereg_rapid is used to send one goodbye instead of three, when we want the memory available for reuse sooner
2792// mDNS_Dereg_conflict is used to indicate that this record is being forcibly deregistered because of a conflict
2793// mDNS_Dereg_repeat is used when cleaning up, for records that may have already been forcibly deregistered
2794typedef enum { mDNS_Dereg_normal, mDNS_Dereg_rapid, mDNS_Dereg_conflict, mDNS_Dereg_repeat } mDNS_Dereg_type;
2795
2796// mDNS_RegisterService is a single call to register the set of resource records associated with a given named service.
2797//
2798//
2799// mDNS_AddRecordToService adds an additional record to a Service Record Set.  This record may be deregistered
2800// via mDNS_RemoveRecordFromService, or by deregistering the service.  mDNS_RemoveRecordFromService is passed a
2801// callback to free the memory associated with the extra RR when it is safe to do so.  The ExtraResourceRecord
2802// object can be found in the record's context pointer.
2803
2804// mDNS_GetBrowseDomains is a special case of the mDNS_StartQuery call, where the resulting answers
2805// are a list of PTR records indicating (in the rdata) domains that are recommended for browsing.
2806// After getting the list of domains to browse, call mDNS_StopQuery to end the search.
2807// mDNS_GetDefaultBrowseDomain returns the name of the domain that should be highlighted by default.
2808//
2809// mDNS_GetRegistrationDomains and mDNS_GetDefaultRegistrationDomain are the equivalent calls to get the list
2810// of one or more domains that should be offered to the user as choices for where they may register their service,
2811// and the default domain in which to register in the case where the user has made no selection.
2812
2813extern void    mDNS_SetupResourceRecord(AuthRecord *rr, RData *RDataStorage, mDNSInterfaceID InterfaceID,
2814                                        mDNSu16 rrtype, mDNSu32 ttl, mDNSu8 RecordType, AuthRecType artype, mDNSRecordCallback Callback, void *Context);
2815
2816extern mDNSu32 deriveD2DFlagsFromAuthRecType(AuthRecType authRecType);
2817extern mStatus mDNS_RegisterService  (mDNS *const m, ServiceRecordSet *sr,
2818                                      const domainlabel *const name, const domainname *const type, const domainname *const domain,
2819                                      const domainname *const host, mDNSIPPort port, RData *txtrdata, const mDNSu8 txtinfo[], mDNSu16 txtlen,
2820                                      AuthRecord *SubTypes, mDNSu32 NumSubTypes,
2821                                      mDNSInterfaceID InterfaceID, mDNSServiceCallback Callback, void *Context, mDNSu32 flags);
2822extern mStatus mDNS_AddRecordToService(mDNS *const m, ServiceRecordSet *sr, ExtraResourceRecord *extra, RData *rdata, mDNSu32 ttl,  mDNSu32 flags);
2823extern mStatus mDNS_RemoveRecordFromService(mDNS *const m, ServiceRecordSet *sr, ExtraResourceRecord *extra, mDNSRecordCallback MemFreeCallback, void *Context);
2824extern mStatus mDNS_RenameAndReregisterService(mDNS *const m, ServiceRecordSet *const sr, const domainlabel *newname);
2825extern mStatus mDNS_DeregisterService_drt(mDNS *const m, ServiceRecordSet *sr, mDNS_Dereg_type drt);
2826#define mDNS_DeregisterService(M,S) mDNS_DeregisterService_drt((M), (S), mDNS_Dereg_normal)
2827
2828extern mStatus mDNS_RegisterNoSuchService(mDNS *const m, AuthRecord *const rr,
2829                                          const domainlabel *const name, const domainname *const type, const domainname *const domain,
2830                                          const domainname *const host,
2831                                          const mDNSInterfaceID InterfaceID, mDNSRecordCallback Callback, void *Context, mDNSu32 flags);
2832#define        mDNS_DeregisterNoSuchService mDNS_Deregister
2833
2834extern void mDNS_SetupQuestion(DNSQuestion *const q, const mDNSInterfaceID InterfaceID, const domainname *const name,
2835                               const mDNSu16 qtype, mDNSQuestionCallback *const callback, void *const context);
2836
2837extern mStatus mDNS_StartBrowse(mDNS *const m, DNSQuestion *const question,
2838                                const domainname *const srv, const domainname *const domain, const mDNSu8 *anondata,
2839                                const mDNSInterfaceID InterfaceID, mDNSu32 flags,
2840                                mDNSBool ForceMCast, mDNSBool useBackgroundTrafficClass,
2841                                mDNSQuestionCallback *Callback, void *Context);
2842#define        mDNS_StopBrowse mDNS_StopQuery
2843
2844
2845typedef enum
2846{
2847    mDNS_DomainTypeBrowse              = 0,
2848    mDNS_DomainTypeBrowseDefault       = 1,
2849    mDNS_DomainTypeBrowseAutomatic     = 2,
2850    mDNS_DomainTypeRegistration        = 3,
2851    mDNS_DomainTypeRegistrationDefault = 4,
2852
2853    mDNS_DomainTypeMax = 4
2854} mDNS_DomainType;
2855
2856extern const char *const mDNS_DomainTypeNames[];
2857
2858extern mStatus mDNS_GetDomains(mDNS *const m, DNSQuestion *const question, mDNS_DomainType DomainType, const domainname *dom,
2859                               const mDNSInterfaceID InterfaceID, mDNSQuestionCallback *Callback, void *Context);
2860#define        mDNS_StopGetDomains mDNS_StopQuery
2861extern mStatus mDNS_AdvertiseDomains(mDNS *const m, AuthRecord *rr, mDNS_DomainType DomainType, const mDNSInterfaceID InterfaceID, char *domname);
2862#define        mDNS_StopAdvertiseDomains mDNS_Deregister
2863
2864extern mDNSOpaque16 mDNS_NewMessageID(mDNS *const m);
2865extern mDNSBool mDNS_AddressIsLocalSubnet(mDNS *const m, const mDNSInterfaceID InterfaceID, const mDNSAddr *addr);
2866
2867extern DNSServer *GetServerForQuestion(mDNS *m, DNSQuestion *question);
2868extern mDNSu32 SetValidDNSServers(mDNS *m, DNSQuestion *question);
2869
2870// ***************************************************************************
2871#if 0
2872#pragma mark -
2873#pragma mark - DNS name utility functions
2874#endif
2875
2876// In order to expose the full capabilities of the DNS protocol (which allows any arbitrary eight-bit values
2877// in domain name labels, including unlikely characters like ascii nulls and even dots) all the mDNS APIs
2878// work with DNS's native length-prefixed strings. For convenience in C, the following utility functions
2879// are provided for converting between C's null-terminated strings and DNS's length-prefixed strings.
2880
2881// Assignment
2882// A simple C structure assignment of a domainname can cause a protection fault by accessing unmapped memory,
2883// because that object is defined to be 256 bytes long, but not all domainname objects are truly the full size.
2884// This macro uses mDNSPlatformMemCopy() to make sure it only touches the actual bytes that are valid.
2885#define AssignDomainName(DST, SRC) do { mDNSu16 len__ = DomainNameLength((SRC)); \
2886    if (len__ <= MAX_DOMAIN_NAME) mDNSPlatformMemCopy((DST)->c, (SRC)->c, len__); else (DST)->c[0] = 0; } while(0)
2887
2888// Comparison functions
2889#define SameDomainLabelCS(A,B) ((A)[0] == (B)[0] && mDNSPlatformMemSame((A)+1, (B)+1, (A)[0]))
2890extern mDNSBool SameDomainLabel(const mDNSu8 *a, const mDNSu8 *b);
2891extern mDNSBool SameDomainName(const domainname *const d1, const domainname *const d2);
2892extern mDNSBool SameDomainNameCS(const domainname *const d1, const domainname *const d2);
2893typedef mDNSBool DomainNameComparisonFn (const domainname *const d1, const domainname *const d2);
2894extern mDNSBool IsLocalDomain(const domainname *d);     // returns true for domains that by default should be looked up using link-local multicast
2895
2896#define StripFirstLabel(X) ((const domainname *)& (X)->c[(X)->c[0] ? 1 + (X)->c[0] : 0])
2897
2898#define FirstLabel(X)  ((const domainlabel *)(X))
2899#define SecondLabel(X) ((const domainlabel *)StripFirstLabel(X))
2900#define ThirdLabel(X)  ((const domainlabel *)StripFirstLabel(StripFirstLabel(X)))
2901
2902extern const mDNSu8 *LastLabel(const domainname *d);
2903
2904// Get total length of domain name, in native DNS format, including terminal root label
2905//   (e.g. length of "com." is 5 (length byte, three data bytes, final zero)
2906extern mDNSu16  DomainNameLengthLimit(const domainname *const name, const mDNSu8 *limit);
2907#define DomainNameLength(name) DomainNameLengthLimit((name), (name)->c + MAX_DOMAIN_NAME)
2908
2909// Append functions to append one or more labels to an existing native format domain name:
2910//   AppendLiteralLabelString adds a single label from a literal C string, with no escape character interpretation.
2911//   AppendDNSNameString      adds zero or more labels from a C string using conventional DNS dots-and-escaping interpretation
2912//   AppendDomainLabel        adds a single label from a native format domainlabel
2913//   AppendDomainName         adds zero or more labels from a native format domainname
2914extern mDNSu8  *AppendLiteralLabelString(domainname *const name, const char *cstr);
2915extern mDNSu8  *AppendDNSNameString     (domainname *const name, const char *cstr);
2916extern mDNSu8  *AppendDomainLabel       (domainname *const name, const domainlabel *const label);
2917extern mDNSu8  *AppendDomainName        (domainname *const name, const domainname *const append);
2918
2919// Convert from null-terminated string to native DNS format:
2920//   The DomainLabel form makes a single label from a literal C string, with no escape character interpretation.
2921//   The DomainName form makes native format domain name from a C string using conventional DNS interpretation:
2922//     dots separate labels, and within each label, '\.' represents a literal dot, '\\' represents a literal
2923//     backslash and backslash with three decimal digits (e.g. \000) represents an arbitrary byte value.
2924extern mDNSBool MakeDomainLabelFromLiteralString(domainlabel *const label, const char *cstr);
2925extern mDNSu8  *MakeDomainNameFromDNSNameString (domainname  *const name,  const char *cstr);
2926
2927// Convert native format domainlabel or domainname back to C string format
2928// IMPORTANT:
2929// When using ConvertDomainLabelToCString, the target buffer must be MAX_ESCAPED_DOMAIN_LABEL (254) bytes long
2930// to guarantee there will be no buffer overrun. It is only safe to use a buffer shorter than this in rare cases
2931// where the label is known to be constrained somehow (for example, if the label is known to be either "_tcp" or "_udp").
2932// Similarly, when using ConvertDomainNameToCString, the target buffer must be MAX_ESCAPED_DOMAIN_NAME (1009) bytes long.
2933// See definitions of MAX_ESCAPED_DOMAIN_LABEL and MAX_ESCAPED_DOMAIN_NAME for more detailed explanation.
2934extern char    *ConvertDomainLabelToCString_withescape(const domainlabel *const name, char *cstr, char esc);
2935#define         ConvertDomainLabelToCString_unescaped(D,C) ConvertDomainLabelToCString_withescape((D), (C), 0)
2936#define         ConvertDomainLabelToCString(D,C)           ConvertDomainLabelToCString_withescape((D), (C), '\\')
2937extern char    *ConvertDomainNameToCString_withescape(const domainname *const name, char *cstr, char esc);
2938#define         ConvertDomainNameToCString_unescaped(D,C) ConvertDomainNameToCString_withescape((D), (C), 0)
2939#define         ConvertDomainNameToCString(D,C)           ConvertDomainNameToCString_withescape((D), (C), '\\')
2940
2941extern void     ConvertUTF8PstringToRFC1034HostLabel(const mDNSu8 UTF8Name[], domainlabel *const hostlabel);
2942
2943#define ValidTransportProtocol(X) ( (X)[0] == 4 && (X)[1] == '_' && \
2944                                    ((((X)[2] | 0x20) == 'u' && ((X)[3] | 0x20) == 'd') || (((X)[2] | 0x20) == 't' && ((X)[3] | 0x20) == 'c')) && \
2945                                    ((X)[4] | 0x20) == 'p')
2946
2947extern mDNSu8  *ConstructServiceName(domainname *const fqdn, const domainlabel *name, const domainname *type, const domainname *const domain);
2948extern mDNSBool DeconstructServiceName(const domainname *const fqdn, domainlabel *const name, domainname *const type, domainname *const domain);
2949
2950// Note: Some old functions have been replaced by more sensibly-named versions.
2951// You can uncomment the hash-defines below if you don't want to have to change your source code right away.
2952// When updating your code, note that (unlike the old versions) *all* the new routines take the target object
2953// as their first parameter.
2954//#define ConvertCStringToDomainName(SRC,DST)  MakeDomainNameFromDNSNameString((DST),(SRC))
2955//#define ConvertCStringToDomainLabel(SRC,DST) MakeDomainLabelFromLiteralString((DST),(SRC))
2956//#define AppendStringLabelToName(DST,SRC)     AppendLiteralLabelString((DST),(SRC))
2957//#define AppendStringNameToName(DST,SRC)      AppendDNSNameString((DST),(SRC))
2958//#define AppendDomainLabelToName(DST,SRC)     AppendDomainLabel((DST),(SRC))
2959//#define AppendDomainNameToName(DST,SRC)      AppendDomainName((DST),(SRC))
2960
2961// ***************************************************************************
2962#if 0
2963#pragma mark -
2964#pragma mark - Other utility functions and macros
2965#endif
2966
2967// mDNS_vsnprintf/snprintf return the number of characters written, excluding the final terminating null.
2968// The output is always null-terminated: for example, if the output turns out to be exactly buflen long,
2969// then the output will be truncated by one character to allow space for the terminating null.
2970// Unlike standard C vsnprintf/snprintf, they return the number of characters *actually* written,
2971// not the number of characters that *would* have been printed were buflen unlimited.
2972extern mDNSu32 mDNS_vsnprintf(char *sbuffer, mDNSu32 buflen, const char *fmt, va_list arg) IS_A_PRINTF_STYLE_FUNCTION(3,0);
2973extern mDNSu32 mDNS_snprintf(char *sbuffer, mDNSu32 buflen, const char *fmt, ...) IS_A_PRINTF_STYLE_FUNCTION(3,4);
2974extern mDNSu32 NumCacheRecordsForInterfaceID(const mDNS *const m, mDNSInterfaceID id);
2975extern char *DNSTypeName(mDNSu16 rrtype);
2976extern char *GetRRDisplayString_rdb(const ResourceRecord *const rr, const RDataBody *const rd1, char *const buffer);
2977#define RRDisplayString(m, rr) GetRRDisplayString_rdb(rr, &(rr)->rdata->u, (m)->MsgBuffer)
2978#define ARDisplayString(m, rr) GetRRDisplayString_rdb(&(rr)->resrec, &(rr)->resrec.rdata->u, (m)->MsgBuffer)
2979#define CRDisplayString(m, rr) GetRRDisplayString_rdb(&(rr)->resrec, &(rr)->resrec.rdata->u, (m)->MsgBuffer)
2980#define MortalityDisplayString(M) (M == Mortality_Mortal ? "mortal" : (M == Mortality_Immortal ? "immortal" : "ghost"))
2981extern mDNSBool mDNSSameAddress(const mDNSAddr *ip1, const mDNSAddr *ip2);
2982extern void IncrementLabelSuffix(domainlabel *name, mDNSBool RichText);
2983extern mDNSBool mDNSv4AddrIsRFC1918(const mDNSv4Addr * const addr);  // returns true for RFC1918 private addresses
2984#define mDNSAddrIsRFC1918(X) ((X)->type == mDNSAddrType_IPv4 && mDNSv4AddrIsRFC1918(&(X)->ip.v4))
2985
2986// For PCP
2987extern void mDNSAddrMapIPv4toIPv6(mDNSv4Addr* in, mDNSv6Addr* out);
2988extern mDNSBool mDNSAddrIPv4FromMappedIPv6(mDNSv6Addr *in, mDNSv4Addr *out);
2989
2990#define mDNSSameIPPort(A,B)      ((A).NotAnInteger == (B).NotAnInteger)
2991#define mDNSSameOpaque16(A,B)    ((A).NotAnInteger == (B).NotAnInteger)
2992#define mDNSSameOpaque32(A,B)    ((A).NotAnInteger == (B).NotAnInteger)
2993#define mDNSSameOpaque64(A,B)    ((A)->l[0] == (B)->l[0] && (A)->l[1] == (B)->l[1])
2994
2995#define mDNSSameIPv4Address(A,B) ((A).NotAnInteger == (B).NotAnInteger)
2996#define mDNSSameIPv6Address(A,B) ((A).l[0] == (B).l[0] && (A).l[1] == (B).l[1] && (A).l[2] == (B).l[2] && (A).l[3] == (B).l[3])
2997#define mDNSSameIPv6NetworkPart(A,B) ((A).l[0] == (B).l[0] && (A).l[1] == (B).l[1])
2998#define mDNSSameEthAddress(A,B)  ((A)->w[0] == (B)->w[0] && (A)->w[1] == (B)->w[1] && (A)->w[2] == (B)->w[2])
2999
3000#define mDNSIPPortIsZero(A)      ((A).NotAnInteger                            == 0)
3001#define mDNSOpaque16IsZero(A)    ((A).NotAnInteger                            == 0)
3002#define mDNSOpaque64IsZero(A)    (((A)->l[0] | (A)->l[1]                    ) == 0)
3003#define mDNSOpaque128IsZero(A)   (((A)->l[0] | (A)->l[1] | (A)->l[2] | (A)->l[3]) == 0)
3004#define mDNSIPv4AddressIsZero(A) ((A).NotAnInteger                            == 0)
3005#define mDNSIPv6AddressIsZero(A) (((A).l[0] | (A).l[1] | (A).l[2] | (A).l[3]) == 0)
3006#define mDNSEthAddressIsZero(A)  (((A).w[0] | (A).w[1] | (A).w[2]           ) == 0)
3007
3008#define mDNSIPv4AddressIsOnes(A) ((A).NotAnInteger == 0xFFFFFFFF)
3009#define mDNSIPv6AddressIsOnes(A) (((A).l[0] & (A).l[1] & (A).l[2] & (A).l[3]) == 0xFFFFFFFF)
3010
3011#define mDNSAddressIsAllDNSLinkGroup(X) (                                                            \
3012        ((X)->type == mDNSAddrType_IPv4 && mDNSSameIPv4Address((X)->ip.v4, AllDNSLinkGroup_v4.ip.v4)) || \
3013        ((X)->type == mDNSAddrType_IPv6 && mDNSSameIPv6Address((X)->ip.v6, AllDNSLinkGroup_v6.ip.v6))    )
3014
3015#define mDNSAddressIsZero(X) (                                                \
3016        ((X)->type == mDNSAddrType_IPv4 && mDNSIPv4AddressIsZero((X)->ip.v4))  || \
3017        ((X)->type == mDNSAddrType_IPv6 && mDNSIPv6AddressIsZero((X)->ip.v6))     )
3018
3019#define mDNSAddressIsValidNonZero(X) (                                        \
3020        ((X)->type == mDNSAddrType_IPv4 && !mDNSIPv4AddressIsZero((X)->ip.v4)) || \
3021        ((X)->type == mDNSAddrType_IPv6 && !mDNSIPv6AddressIsZero((X)->ip.v6))    )
3022
3023#define mDNSAddressIsOnes(X) (                                                \
3024        ((X)->type == mDNSAddrType_IPv4 && mDNSIPv4AddressIsOnes((X)->ip.v4))  || \
3025        ((X)->type == mDNSAddrType_IPv6 && mDNSIPv6AddressIsOnes((X)->ip.v6))     )
3026
3027#define mDNSAddressIsValid(X) (                                                                                             \
3028        ((X)->type == mDNSAddrType_IPv4) ? !(mDNSIPv4AddressIsZero((X)->ip.v4) || mDNSIPv4AddressIsOnes((X)->ip.v4)) :          \
3029        ((X)->type == mDNSAddrType_IPv6) ? !(mDNSIPv6AddressIsZero((X)->ip.v6) || mDNSIPv6AddressIsOnes((X)->ip.v6)) : mDNSfalse)
3030
3031#define mDNSv4AddressIsLinkLocal(X) ((X)->b[0] ==  169 &&  (X)->b[1]         ==  254)
3032#define mDNSv6AddressIsLinkLocal(X) ((X)->b[0] == 0xFE && ((X)->b[1] & 0xC0) == 0x80)
3033
3034#define mDNSAddressIsLinkLocal(X)  (                                                    \
3035        ((X)->type == mDNSAddrType_IPv4) ? mDNSv4AddressIsLinkLocal(&(X)->ip.v4) :          \
3036        ((X)->type == mDNSAddrType_IPv6) ? mDNSv6AddressIsLinkLocal(&(X)->ip.v6) : mDNSfalse)
3037
3038
3039// ***************************************************************************
3040#if 0
3041#pragma mark -
3042#pragma mark - Authentication Support
3043#endif
3044
3045// Unicast DNS and Dynamic Update specific Client Calls
3046//
3047// mDNS_SetSecretForDomain tells the core to authenticate (via TSIG with an HMAC_MD5 hash of the shared secret)
3048// when dynamically updating a given zone (and its subdomains).  The key used in authentication must be in
3049// domain name format.  The shared secret must be a null-terminated base64 encoded string.  A minimum size of
3050// 16 bytes (128 bits) is recommended for an MD5 hash as per RFC 2485.
3051// Calling this routine multiple times for a zone replaces previously entered values.  Call with a NULL key
3052// to disable authentication for the zone.  A non-NULL autoTunnelPrefix means this is an AutoTunnel domain,
3053// and the value is prepended to the IPSec identifier (used for key lookup)
3054
3055extern mStatus mDNS_SetSecretForDomain(mDNS *m, DomainAuthInfo *info,
3056                                       const domainname *domain, const domainname *keyname, const char *b64keydata, const domainname *hostname, mDNSIPPort *port, mDNSBool autoTunnel);
3057
3058extern void RecreateNATMappings(mDNS *const m, const mDNSu32 waitTicks);
3059
3060// Hostname/Unicast Interface Configuration
3061
3062// All hostnames advertised point to one IPv4 address and/or one IPv6 address, set via SetPrimaryInterfaceInfo.  Invoking this routine
3063// updates all existing hostnames to point to the new address.
3064
3065// A hostname is added via AddDynDNSHostName, which points to the primary interface's v4 and/or v6 addresss
3066
3067// The status callback is invoked to convey success or failure codes - the callback should not modify the AuthRecord or free memory.
3068// Added hostnames may be removed (deregistered) via mDNS_RemoveDynDNSHostName.
3069
3070// Host domains added prior to specification of the primary interface address and computer name will be deferred until
3071// these values are initialized.
3072
3073// DNS servers used to resolve unicast queries are specified by mDNS_AddDNSServer.
3074// For "split" DNS configurations, in which queries for different domains are sent to different servers (e.g. VPN and external),
3075// a domain may be associated with a DNS server.  For standard configurations, specify the root label (".") or NULL.
3076
3077extern void mDNS_AddDynDNSHostName(mDNS *m, const domainname *fqdn, mDNSRecordCallback *StatusCallback, const void *StatusContext);
3078extern void mDNS_RemoveDynDNSHostName(mDNS *m, const domainname *fqdn);
3079extern void mDNS_SetPrimaryInterfaceInfo(mDNS *m, const mDNSAddr *v4addr,  const mDNSAddr *v6addr, const mDNSAddr *router);
3080extern DNSServer *mDNS_AddDNSServer(mDNS *const m, const domainname *d, const mDNSInterfaceID interface, mDNSs32 serviceID, const mDNSAddr *addr,
3081                                    const mDNSIPPort port, mDNSu32 scoped, mDNSu32 timeout, mDNSBool cellIntf, mDNSBool isExpensive, mDNSBool isCLAT46,
3082                                    mDNSu16 resGroupID, mDNSBool reqA, mDNSBool reqAAAA, mDNSBool reqDO);
3083extern void PenalizeDNSServer(mDNS *const m, DNSQuestion *q, mDNSOpaque16 responseFlags);
3084extern void mDNS_AddSearchDomain(const domainname *const domain, mDNSInterfaceID InterfaceID);
3085
3086extern McastResolver *mDNS_AddMcastResolver(mDNS *const m, const domainname *d, const mDNSInterfaceID interface, mDNSu32 timeout);
3087
3088// We use ((void *)0) here instead of mDNSNULL to avoid compile warnings on gcc 4.2
3089#define mDNS_AddSearchDomain_CString(X, I) \
3090    do { domainname d__; if (((X) != (void*)0) && MakeDomainNameFromDNSNameString(&d__, (X)) && d__.c[0]) mDNS_AddSearchDomain(&d__, I);} while(0)
3091
3092// Routines called by the core, exported by DNSDigest.c
3093
3094// Convert an arbitrary base64 encoded key key into an HMAC key (stored in AuthInfo struct)
3095extern mDNSs32 DNSDigest_ConstructHMACKeyfromBase64(DomainAuthInfo *info, const char *b64key);
3096
3097// sign a DNS message.  The message must be complete, with all values in network byte order.  end points to the end
3098// of the message, and is modified by this routine.  numAdditionals is a pointer to the number of additional
3099// records in HOST byte order, which is incremented upon successful completion of this routine.  The function returns
3100// the new end pointer on success, and NULL on failure.
3101extern void DNSDigest_SignMessage(DNSMessage *msg, mDNSu8 **end, DomainAuthInfo *info, mDNSu16 tcode);
3102
3103#define SwapDNSHeaderBytes(M) do { \
3104    (M)->h.numQuestions   = (mDNSu16)((mDNSu8 *)&(M)->h.numQuestions  )[0] << 8 | ((mDNSu8 *)&(M)->h.numQuestions  )[1]; \
3105    (M)->h.numAnswers     = (mDNSu16)((mDNSu8 *)&(M)->h.numAnswers    )[0] << 8 | ((mDNSu8 *)&(M)->h.numAnswers    )[1]; \
3106    (M)->h.numAuthorities = (mDNSu16)((mDNSu8 *)&(M)->h.numAuthorities)[0] << 8 | ((mDNSu8 *)&(M)->h.numAuthorities)[1]; \
3107    (M)->h.numAdditionals = (mDNSu16)((mDNSu8 *)&(M)->h.numAdditionals)[0] << 8 | ((mDNSu8 *)&(M)->h.numAdditionals)[1]; \
3108} while (0)
3109
3110#define DNSDigest_SignMessageHostByteOrder(M,E,INFO) \
3111    do { SwapDNSHeaderBytes(M); DNSDigest_SignMessage((M), (E), (INFO), 0); SwapDNSHeaderBytes(M); } while (0)
3112
3113// verify a DNS message.  The message must be complete, with all values in network byte order.  end points to the
3114// end of the record.  tsig is a pointer to the resource record that contains the TSIG OPT record.  info is
3115// the matching key to use for verifying the message.  This function expects that the additionals member
3116// of the DNS message header has already had one subtracted from it.
3117extern mDNSBool DNSDigest_VerifyMessage(DNSMessage *msg, mDNSu8 *end, LargeCacheRecord *tsig, DomainAuthInfo *info, mDNSu16 *rcode, mDNSu16 *tcode);
3118
3119// ***************************************************************************
3120#if 0
3121#pragma mark -
3122#pragma mark - PlatformSupport interface
3123#endif
3124
3125// This section defines the interface to the Platform Support layer.
3126// Normal client code should not use any of types defined here, or directly call any of the functions defined here.
3127// The definitions are placed here because sometimes clients do use these calls indirectly, via other supported client operations.
3128// For example, AssignDomainName is a macro defined using mDNSPlatformMemCopy()
3129
3130// Every platform support module must provide the following functions.
3131// mDNSPlatformInit() typically opens a communication endpoint, and starts listening for mDNS packets.
3132// When Setup is complete, the platform support layer calls mDNSCoreInitComplete().
3133// mDNSPlatformSendUDP() sends one UDP packet
3134// When a packet is received, the PlatformSupport code calls mDNSCoreReceive()
3135// mDNSPlatformClose() tidies up on exit
3136//
3137// Note: mDNSPlatformMemAllocate/mDNSPlatformMemFree are only required for handling oversized resource records and unicast DNS.
3138// If your target platform has a well-defined specialized application, and you know that all the records it uses
3139// are InlineCacheRDSize or less, then you can just make a simple mDNSPlatformMemAllocate() stub that always returns
3140// NULL. InlineCacheRDSize is a compile-time constant, which is set by default to 68. If you need to handle records
3141// a little larger than this and you don't want to have to implement run-time allocation and freeing, then you
3142// can raise the value of this constant to a suitable value (at the expense of increased memory usage).
3143//
3144// USE CAUTION WHEN CALLING mDNSPlatformRawTime: The m->timenow_adjust correction factor needs to be added
3145// Generally speaking:
3146// Code that's protected by the main mDNS lock should just use the m->timenow value
3147// Code outside the main mDNS lock should use mDNS_TimeNow(m) to get properly adjusted time
3148// In certain cases there may be reasons why it's necessary to get the time without taking the lock first
3149// (e.g. inside the routines that are doing the locking and unlocking, where a call to get the lock would result in a
3150// recursive loop); in these cases use mDNS_TimeNow_NoLock(m) to get mDNSPlatformRawTime with the proper correction factor added.
3151//
3152// mDNSPlatformUTC returns the time, in seconds, since Jan 1st 1970 UTC and is required for generating TSIG records
3153
3154extern mStatus  mDNSPlatformInit        (mDNS *const m);
3155extern void     mDNSPlatformClose       (mDNS *const m);
3156extern mStatus  mDNSPlatformSendUDP(const mDNS *const m, const void *const msg, const mDNSu8 *const end,
3157                                    mDNSInterfaceID InterfaceID, UDPSocket *src, const mDNSAddr *dst,
3158                                    mDNSIPPort dstport, mDNSBool useBackgroundTrafficClass);
3159
3160extern void     mDNSPlatformLock        (const mDNS *const m);
3161extern void     mDNSPlatformUnlock      (const mDNS *const m);
3162
3163extern void     mDNSPlatformStrCopy     (      void *dst, const void *src);
3164extern mDNSu32  mDNSPlatformStrLCopy    (      void *dst, const void *src, mDNSu32 len);
3165extern mDNSu32  mDNSPlatformStrLen      (                 const void *src);
3166extern void     mDNSPlatformMemCopy     (      void *dst, const void *src, mDNSu32 len);
3167extern mDNSBool mDNSPlatformMemSame     (const void *dst, const void *src, mDNSu32 len);
3168extern int      mDNSPlatformMemCmp      (const void *dst, const void *src, mDNSu32 len);
3169extern void     mDNSPlatformMemZero     (      void *dst,                  mDNSu32 len);
3170extern void mDNSPlatformQsort       (void *base, int nel, int width, int (*compar)(const void *, const void *));
3171#if APPLE_OSX_mDNSResponder && MACOSX_MDNS_MALLOC_DEBUGGING
3172#define         mDNSPlatformMemAllocate(X) mallocL(# X, X)
3173#else
3174extern void *   mDNSPlatformMemAllocate (mDNSu32 len);
3175#endif
3176extern void     mDNSPlatformMemFree     (void *mem);
3177
3178// If the platform doesn't have a strong PRNG, we define a naive multiply-and-add based on a seed
3179// from the platform layer.  Long-term, we should embed an arc4 implementation, but the strength
3180// will still depend on the randomness of the seed.
3181#if !defined(_PLATFORM_HAS_STRONG_PRNG_) && (_BUILDING_XCODE_PROJECT_ || defined(_WIN32))
3182#define _PLATFORM_HAS_STRONG_PRNG_ 1
3183#endif
3184#if _PLATFORM_HAS_STRONG_PRNG_
3185extern mDNSu32  mDNSPlatformRandomNumber(void);
3186#else
3187extern mDNSu32  mDNSPlatformRandomSeed  (void);
3188#endif // _PLATFORM_HAS_STRONG_PRNG_
3189
3190extern mStatus  mDNSPlatformTimeInit    (void);
3191extern mDNSs32  mDNSPlatformRawTime     (void);
3192extern mDNSs32  mDNSPlatformUTC         (void);
3193#define mDNS_TimeNow_NoLock(m) (mDNSPlatformRawTime() + (m)->timenow_adjust)
3194
3195#if MDNS_DEBUGMSGS
3196extern void mDNSPlatformWriteDebugMsg(const char *msg);
3197#endif
3198extern void mDNSPlatformWriteLogMsg(const char *ident, const char *msg, mDNSLogLevel_t loglevel);
3199
3200// Platform support modules should provide the following functions to map between opaque interface IDs
3201// and interface indexes in order to support the DNS-SD API. If your target platform does not support
3202// multiple interfaces and/or does not support the DNS-SD API, these functions can be empty.
3203extern mDNSInterfaceID mDNSPlatformInterfaceIDfromInterfaceIndex(mDNS *const m, mDNSu32 ifindex);
3204extern mDNSu32 mDNSPlatformInterfaceIndexfromInterfaceID(mDNS *const m, mDNSInterfaceID id, mDNSBool suppressNetworkChange);
3205
3206// Every platform support module must provide the following functions if it is to support unicast DNS
3207// and Dynamic Update.
3208// All TCP socket operations implemented by the platform layer MUST NOT BLOCK.
3209// mDNSPlatformTCPConnect initiates a TCP connection with a peer, adding the socket descriptor to the
3210// main event loop.  The return value indicates whether the connection succeeded, failed, or is pending
3211// (i.e. the call would block.)  On return, the descriptor parameter is set to point to the connected socket.
3212// The TCPConnectionCallback is subsequently invoked when the connection
3213// completes (in which case the ConnectionEstablished parameter is true), or data is available for
3214// reading on the socket (indicated by the ConnectionEstablished parameter being false.)  If the connection
3215// asynchronously fails, the TCPConnectionCallback should be invoked as usual, with the error being
3216// returned in subsequent calls to PlatformReadTCP or PlatformWriteTCP.  (This allows for platforms
3217// with limited asynchronous error detection capabilities.)  PlatformReadTCP and PlatformWriteTCP must
3218// return the number of bytes read/written, 0 if the call would block, and -1 if an error.  PlatformReadTCP
3219// should set the closed argument if the socket has been closed.
3220// PlatformTCPCloseConnection must close the connection to the peer and remove the descriptor from the
3221// event loop.  CloseConnectin may be called at any time, including in a ConnectionCallback.
3222
3223typedef enum
3224{
3225    kTCPSocketFlags_Zero   = 0,
3226    kTCPSocketFlags_UseTLS = (1 << 0)
3227} TCPSocketFlags;
3228
3229typedef void (*TCPConnectionCallback)(TCPSocket *sock, void *context, mDNSBool ConnectionEstablished, mStatus err);
3230extern TCPSocket *mDNSPlatformTCPSocket(TCPSocketFlags flags, mDNSIPPort *port, mDNSBool useBackgroundTrafficClass); // creates a TCP socket
3231extern TCPSocket *mDNSPlatformTCPAccept(TCPSocketFlags flags, int sd);
3232extern int        mDNSPlatformTCPGetFD(TCPSocket *sock);
3233extern mStatus    mDNSPlatformTCPConnect(TCPSocket *sock, const mDNSAddr *dst, mDNSOpaque16 dstport, domainname *hostname,
3234                                         mDNSInterfaceID InterfaceID, TCPConnectionCallback callback, void *context);
3235extern void       mDNSPlatformTCPCloseConnection(TCPSocket *sock);
3236extern long       mDNSPlatformReadTCP(TCPSocket *sock, void *buf, unsigned long buflen, mDNSBool *closed);
3237extern long       mDNSPlatformWriteTCP(TCPSocket *sock, const char *msg, unsigned long len);
3238extern UDPSocket *mDNSPlatformUDPSocket(const mDNSIPPort requestedport);
3239extern mDNSu16    mDNSPlatformGetUDPPort(UDPSocket *sock);
3240extern void       mDNSPlatformUDPClose(UDPSocket *sock);
3241extern mDNSBool   mDNSPlatformUDPSocketEncounteredEOF(const UDPSocket *sock);
3242extern void       mDNSPlatformReceiveBPF_fd(int fd);
3243extern void       mDNSPlatformUpdateProxyList(const mDNSInterfaceID InterfaceID);
3244extern void       mDNSPlatformSendRawPacket(const void *const msg, const mDNSu8 *const end, mDNSInterfaceID InterfaceID);
3245extern void       mDNSPlatformSetLocalAddressCacheEntry(const mDNSAddr *const tpa, const mDNSEthAddr *const tha, mDNSInterfaceID InterfaceID);
3246extern void       mDNSPlatformSourceAddrForDest(mDNSAddr *const src, const mDNSAddr *const dst);
3247extern void       mDNSPlatformSendKeepalive(mDNSAddr *sadd, mDNSAddr *dadd, mDNSIPPort *lport, mDNSIPPort *rport, mDNSu32 seq, mDNSu32 ack, mDNSu16 win);
3248extern mStatus    mDNSPlatformRetrieveTCPInfo(mDNSAddr *laddr, mDNSIPPort *lport, mDNSAddr *raddr,  mDNSIPPort *rport, mDNSTCPInfo *mti);
3249extern mStatus    mDNSPlatformGetRemoteMacAddr(mDNSAddr *raddr);
3250extern mStatus    mDNSPlatformStoreSPSMACAddr(mDNSAddr *spsaddr, char *ifname);
3251extern mStatus    mDNSPlatformClearSPSData(void);
3252extern mStatus    mDNSPlatformStoreOwnerOptRecord(char *ifname, DNSMessage *msg, int length);
3253
3254// mDNSPlatformTLSSetupCerts/mDNSPlatformTLSTearDownCerts used by dnsextd
3255extern mStatus    mDNSPlatformTLSSetupCerts(void);
3256extern void       mDNSPlatformTLSTearDownCerts(void);
3257
3258// Platforms that support unicast browsing and dynamic update registration for clients who do not specify a domain
3259// in browse/registration calls must implement these routines to get the "default" browse/registration list.
3260
3261extern mDNSBool   mDNSPlatformSetDNSConfig(mDNSBool setservers, mDNSBool setsearch, domainname *const fqdn, DNameListElem **RegDomains,
3262                        DNameListElem **BrowseDomains, mDNSBool ackConfig);
3263extern mStatus    mDNSPlatformGetPrimaryInterface(mDNSAddr *v4, mDNSAddr *v6, mDNSAddr *router);
3264extern void       mDNSPlatformDynDNSHostNameStatusChanged(const domainname *const dname, const mStatus status);
3265
3266extern void       mDNSPlatformSetAllowSleep(mDNSBool allowSleep, const char *reason);
3267extern void       mDNSPlatformPreventSleep(mDNSu32 timeout, const char *reason);
3268extern void       mDNSPlatformSendWakeupPacket(mDNSInterfaceID InterfaceID, char *EthAddr, char *IPAddr, int iteration);
3269
3270extern mDNSBool   mDNSPlatformInterfaceIsD2D(mDNSInterfaceID InterfaceID);
3271extern mDNSBool   mDNSPlatformInterfaceIsAWDL(const NetworkInterfaceInfo *intf);
3272extern mDNSBool   mDNSPlatformValidRecordForQuestion(const ResourceRecord *const rr, const DNSQuestion *const q);
3273extern mDNSBool   mDNSPlatformValidRecordForInterface(const AuthRecord *rr, mDNSInterfaceID InterfaceID);
3274extern mDNSBool   mDNSPlatformValidQuestionForInterface(DNSQuestion *q, const NetworkInterfaceInfo *intf);
3275
3276extern void mDNSPlatformFormatTime(unsigned long t, mDNSu8 *buf, int bufsize);
3277
3278#ifdef _LEGACY_NAT_TRAVERSAL_
3279// Support for legacy NAT traversal protocols, implemented by the platform layer and callable by the core.
3280extern void     LNT_SendDiscoveryMsg(mDNS *m);
3281extern void     LNT_ConfigureRouterInfo(mDNS *m, const mDNSInterfaceID InterfaceID, const mDNSu8 *const data, const mDNSu16 len);
3282extern mStatus  LNT_GetExternalAddress(mDNS *m);
3283extern mStatus  LNT_MapPort(mDNS *m, NATTraversalInfo *const n);
3284extern mStatus  LNT_UnmapPort(mDNS *m, NATTraversalInfo *const n);
3285extern void     LNT_ClearState(mDNS *const m);
3286#endif // _LEGACY_NAT_TRAVERSAL_
3287
3288// The core mDNS code provides these functions, for the platform support code to call at appropriate times
3289//
3290// mDNS_SetFQDN() is called once on startup (typically from mDNSPlatformInit())
3291// and then again on each subsequent change of the host name.
3292//
3293// mDNS_RegisterInterface() is used by the platform support layer to inform mDNSCore of what
3294// physical and/or logical interfaces are available for sending and receiving packets.
3295// Typically it is called on startup for each available interface, but register/deregister may be
3296// called again later, on multiple occasions, to inform the core of interface configuration changes.
3297// If set->Advertise is set non-zero, then mDNS_RegisterInterface() also registers the standard
3298// resource records that should be associated with every publicised IP address/interface:
3299// -- Name-to-address records (A/AAAA)
3300// -- Address-to-name records (PTR)
3301// -- Host information (HINFO)
3302// IMPORTANT: The specified mDNSInterfaceID MUST NOT be 0, -1, or -2; these values have special meaning
3303// mDNS_RegisterInterface does not result in the registration of global hostnames via dynamic update -
3304// see mDNS_SetPrimaryInterfaceInfo, mDNS_AddDynDNSHostName, etc. for this purpose.
3305// Note that the set may be deallocated immediately after it is deregistered via mDNS_DeegisterInterface.
3306//
3307// mDNS_RegisterDNS() is used by the platform support layer to provide the core with the addresses of
3308// available domain name servers for unicast queries/updates.  RegisterDNS() should be called once for
3309// each name server, typically at startup, or when a new name server becomes available.  DeregiterDNS()
3310// must be called whenever a registered name server becomes unavailable.  DeregisterDNSList deregisters
3311// all registered servers.  mDNS_DNSRegistered() returns true if one or more servers are registered in the core.
3312//
3313// mDNSCoreInitComplete() is called when the platform support layer is finished.
3314// Typically this is at the end of mDNSPlatformInit(), but may be later
3315// (on platforms like OT that allow asynchronous initialization of the networking stack).
3316//
3317// mDNSCoreReceive() is called when a UDP packet is received
3318//
3319// mDNSCoreMachineSleep() is called when the machine sleeps or wakes
3320// (This refers to heavyweight laptop-style sleep/wake that disables network access,
3321// not lightweight second-by-second CPU power management modes.)
3322
3323extern void     mDNS_SetFQDN(mDNS *const m);
3324extern void     mDNS_ActivateNetWake_internal  (mDNS *const m, NetworkInterfaceInfo *set);
3325extern void     mDNS_DeactivateNetWake_internal(mDNS *const m, NetworkInterfaceInfo *set);
3326
3327// Attributes that controls the Bonjour operation initiation and response speed for an interface.
3328typedef enum
3329{
3330    FastActivation,     // For p2p* and DirectLink type interfaces
3331    NormalActivation,   // For standard interface timing
3332    SlowActivation      // For flapping interfaces
3333} InterfaceActivationSpeed;
3334
3335extern mStatus  mDNS_RegisterInterface  (mDNS *const m, NetworkInterfaceInfo *set, InterfaceActivationSpeed probeDelay);
3336extern void     mDNS_DeregisterInterface(mDNS *const m, NetworkInterfaceInfo *set, InterfaceActivationSpeed probeDelay);
3337extern void     mDNSCoreInitComplete(mDNS *const m, mStatus result);
3338extern void     mDNSCoreReceive(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end,
3339                                const mDNSAddr *const srcaddr, const mDNSIPPort srcport,
3340                                const mDNSAddr *dstaddr, const mDNSIPPort dstport, const mDNSInterfaceID InterfaceID);
3341extern void     mDNSCoreRestartQueries(mDNS *const m);
3342extern void     mDNSCoreRestartQuestion(mDNS *const m, DNSQuestion *q);
3343extern void     mDNSCoreRestartRegistration(mDNS *const m, AuthRecord  *rr, int announceCount);
3344typedef void (*FlushCache)(mDNS *const m);
3345typedef void (*CallbackBeforeStartQuery)(mDNS *const m, void *context);
3346extern void     mDNSCoreRestartAddressQueries(mDNS *const m, mDNSBool SearchDomainsChanged, FlushCache flushCacheRecords,
3347                                              CallbackBeforeStartQuery beforeQueryStart, void *context);
3348extern mDNSBool mDNSCoreHaveAdvertisedMulticastServices(mDNS *const m);
3349extern void     mDNSCoreMachineSleep(mDNS *const m, mDNSBool wake);
3350extern mDNSBool mDNSCoreReadyForSleep(mDNS *m, mDNSs32 now);
3351extern mDNSs32  mDNSCoreIntervalToNextWake(mDNS *const m, mDNSs32 now);
3352
3353extern void     mDNSCoreReceiveRawPacket  (mDNS *const m, const mDNSu8 *const p, const mDNSu8 *const end, const mDNSInterfaceID InterfaceID);
3354
3355extern mDNSBool mDNSAddrIsDNSMulticast(const mDNSAddr *ip);
3356
3357extern CacheRecord *CreateNewCacheEntry(mDNS *const m, const mDNSu32 slot, CacheGroup *cg, mDNSs32 delay, mDNSBool Add, const mDNSAddr *sourceAddress);
3358extern CacheGroup *CacheGroupForName(const mDNS *const m, const mDNSu32 namehash, const domainname *const name);
3359extern void ReleaseCacheRecord(mDNS *const m, CacheRecord *r);
3360extern void ScheduleNextCacheCheckTime(mDNS *const m, const mDNSu32 slot, const mDNSs32 event);
3361extern void SetNextCacheCheckTimeForRecord(mDNS *const m, CacheRecord *const rr);
3362extern void GrantCacheExtensions(mDNS *const m, DNSQuestion *q, mDNSu32 lease);
3363extern void MakeNegativeCacheRecord(mDNS *const m, CacheRecord *const cr,
3364                                    const domainname *const name, const mDNSu32 namehash, const mDNSu16 rrtype, const mDNSu16 rrclass, mDNSu32 ttl_seconds,
3365                                    mDNSInterfaceID InterfaceID, DNSServer *dnsserver);
3366extern void CompleteDeregistration(mDNS *const m, AuthRecord *rr);
3367extern void AnswerCurrentQuestionWithResourceRecord(mDNS *const m, CacheRecord *const rr, const QC_result AddRecord);
3368extern void AnswerQuestionByFollowingCNAME(mDNS *const m, DNSQuestion *q, ResourceRecord *rr);
3369extern char *InterfaceNameForID(mDNS *const m, const mDNSInterfaceID InterfaceID);
3370extern void DNSServerChangeForQuestion(mDNS *const m, DNSQuestion *q, DNSServer *newServer);
3371extern void ActivateUnicastRegistration(mDNS *const m, AuthRecord *const rr);
3372extern void CheckSuppressUnusableQuestions(mDNS *const m);
3373extern void RetrySearchDomainQuestions(mDNS *const m);
3374extern mDNSBool DomainEnumQuery(const domainname *qname);
3375extern mStatus UpdateKeepaliveRData(mDNS *const m, AuthRecord *rr, NetworkInterfaceInfo *const intf, mDNSBool updateMac, char *ethAddr);
3376extern void  UpdateKeepaliveRMACAsync(mDNS *const m, void *context);
3377extern void UpdateRMAC(mDNS *const m, void *context);
3378
3379// Used only in logging to restrict the number of /etc/hosts entries printed
3380extern void FreeEtcHosts(mDNS *const m, AuthRecord *const rr, mStatus result);
3381// exported for using the hash for /etc/hosts AuthRecords
3382extern AuthGroup *AuthGroupForName(AuthHash *r, const mDNSu32 namehash, const domainname *const name);
3383extern AuthGroup *AuthGroupForRecord(AuthHash *r, const ResourceRecord *const rr);
3384extern AuthGroup *InsertAuthRecord(mDNS *const m, AuthHash *r, AuthRecord *rr);
3385extern AuthGroup *RemoveAuthRecord(mDNS *const m, AuthHash *r, AuthRecord *rr);
3386extern mDNSBool mDNS_CheckForCacheRecord(mDNS *const m, DNSQuestion *q, mDNSu16 qtype);
3387
3388// For now this AutoTunnel stuff is specific to Mac OS X.
3389// In the future, if there's demand, we may see if we can abstract it out cleanly into the platform layer
3390#if APPLE_OSX_mDNSResponder
3391extern void AutoTunnelCallback(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord);
3392extern void AddNewClientTunnel(DNSQuestion *const q);
3393extern void StartServerTunnel(DomainAuthInfo *const info);
3394extern void UpdateAutoTunnelDomainStatuses(const mDNS *const m);
3395extern void RemoveAutoTunnel6Record(mDNS *const m);
3396extern mDNSBool RecordReadyForSleep(AuthRecord *rr);
3397// For now this LocalSleepProxy stuff is specific to Mac OS X.
3398// In the future, if there's demand, we may see if we can abstract it out cleanly into the platform layer
3399extern mStatus ActivateLocalProxy(NetworkInterfaceInfo *const intf, mDNSBool offloadKeepAlivesOnly, mDNSBool *keepaliveOnly);
3400extern void mDNSPlatformUpdateDNSStatus(DNSQuestion *q);
3401extern void mDNSPlatformTriggerDNSRetry(DNSQuestion *v4q, DNSQuestion *v6q);
3402extern void mDNSPlatformLogToFile(int log_level, const char *buffer);
3403extern mDNSBool SupportsInNICProxy(NetworkInterfaceInfo *const intf);
3404extern mStatus SymptomReporterDNSServerReachable(mDNS *const m, const mDNSAddr *addr);
3405extern mStatus SymptomReporterDNSServerUnreachable(DNSServer *s);
3406#endif
3407
3408typedef void ProxyCallback (void *socket, DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr,
3409    const mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSIPPort dstport, const mDNSInterfaceID InterfaceID, void *context);
3410extern void mDNSPlatformInitDNSProxySkts(ProxyCallback *UDPCallback, ProxyCallback *TCPCallback);
3411extern void mDNSPlatformCloseDNSProxySkts(mDNS *const m);
3412extern void mDNSPlatformDisposeProxyContext(void *context);
3413extern mDNSu8 *DNSProxySetAttributes(DNSQuestion *q, DNSMessageHeader *h, DNSMessage *msg, mDNSu8 *start, mDNSu8 *limit);
3414
3415#if APPLE_OSX_mDNSResponder
3416extern void mDNSPlatformGetDNSRoutePolicy(DNSQuestion *q, mDNSBool *isBlocked);
3417#endif
3418extern void mDNSPlatformSetSocktOpt(void *sock, mDNSTransport_Type transType, mDNSAddr_Type addrType, const DNSQuestion *q);
3419extern mDNSs32 mDNSPlatformGetPID(void);
3420extern mDNSBool mDNSValidKeepAliveRecord(AuthRecord *rr);
3421extern mDNSBool CacheRecordRmvEventsForQuestion(mDNS *const m, DNSQuestion *q);
3422
3423// ***************************************************************************
3424#if 0
3425#pragma mark -
3426#pragma mark - Sleep Proxy
3427#endif
3428
3429// Sleep Proxy Server Property Encoding
3430//
3431// Sleep Proxy Servers are advertised using a structured service name, consisting of four
3432// metrics followed by a human-readable name. The metrics assist clients in deciding which
3433// Sleep Proxy Server(s) to use when multiple are available on the network. Each metric
3434// is a two-digit decimal number in the range 10-99. Lower metrics are generally better.
3435//
3436//   AA-BB-CC-DD.FF Name
3437//
3438// Metrics:
3439//
3440// AA = Intent
3441// BB = Portability
3442// CC = Marginal Power
3443// DD = Total Power
3444// FF = Features Supported (Currently TCP Keepalive only)
3445//
3446//
3447// ** Intent Metric **
3448//
3449// 20 = Dedicated Sleep Proxy Server -- a device, permanently powered on,
3450//      installed for the express purpose of providing Sleep Proxy Service.
3451//
3452// 30 = Primary Network Infrastructure Hardware -- a router, DHCP server, NAT gateway,
3453//      or similar permanently installed device which is permanently powered on.
3454//      This is hardware designed for the express purpose of being network
3455//      infrastructure, and for most home users is typically a single point
3456//      of failure for the local network -- e.g. most home users only have
3457//      a single NAT gateway / DHCP server. Even though in principle the
3458//      hardware might technically be capable of running different software,
3459//      a typical user is unlikely to do that. e.g. AirPort base station.
3460//
3461// 40 = Primary Network Infrastructure Software -- a general-purpose computer
3462//      (e.g. Mac, Windows, Linux, etc.) which is currently running DHCP server
3463//      or NAT gateway software, but the user could choose to turn that off
3464//      fairly easily. e.g. iMac running Internet Sharing
3465//
3466// 50 = Secondary Network Infrastructure Hardware -- like primary infrastructure
3467//      hardware, except not a single point of failure for the entire local network.
3468//      For example, an AirPort base station in bridge mode. This may have clients
3469//      associated with it, and if it goes away those clients will be inconvenienced,
3470//      but unlike the NAT gateway / DHCP server, the entire local network is not
3471//      dependent on it.
3472//
3473// 60 = Secondary Network Infrastructure Software -- like 50, but in a general-
3474//      purpose CPU.
3475//
3476// 70 = Incidentally Available Hardware -- a device which has no power switch
3477//      and is generally left powered on all the time. Even though it is not a
3478//      part of what we conventionally consider network infrastructure (router,
3479//      DHCP, NAT, DNS, etc.), and the rest of the network can operate fine
3480//      without it, since it's available and unlikely to be turned off, it is a
3481//      reasonable candidate for providing Sleep Proxy Service e.g. Apple TV,
3482//      or an AirPort base station in client mode, associated with an existing
3483//      wireless network (e.g. AirPort Express connected to a music system, or
3484//      being used to share a USB printer).
3485//
3486// 80 = Incidentally Available Software -- a general-purpose computer which
3487//      happens at this time to be set to "never sleep", and as such could be
3488//      useful as a Sleep Proxy Server, but has not been intentionally provided
3489//      for this purpose. Of all the Intent Metric categories this is the
3490//      one most likely to be shut down or put to sleep without warning.
3491//      However, if nothing else is availalable, it may be better than nothing.
3492//      e.g. Office computer in the workplace which has been set to "never sleep"
3493//
3494//
3495// ** Portability Metric **
3496//
3497// Inversely related to mass of device, on the basis that, all other things
3498// being equal, heavier devices are less likely to be moved than lighter devices.
3499// E.g. A MacBook running Internet Sharing is probably more likely to be
3500// put to sleep and taken away than a Mac Pro running Internet Sharing.
3501// The Portability Metric is a logarithmic decibel scale, computed by taking the
3502// (approximate) mass of the device in milligrammes, taking the base 10 logarithm
3503// of that, multiplying by 10, and subtracting the result from 100:
3504//
3505//   Portability Metric = 100 - (log10(mg) * 10)
3506//
3507// The Portability Metric is not necessarily computed literally from the actual
3508// mass of the device; the intent is just that lower numbers indicate more
3509// permanent devices, and higher numbers indicate devices more likely to be
3510// removed from the network, e.g., in order of increasing portability:
3511//
3512// Mac Pro < iMac < Laptop < iPhone
3513//
3514// Example values:
3515//
3516// 10 = 1 metric tonne
3517// 40 = 1kg
3518// 70 = 1g
3519// 90 = 10mg
3520//
3521//
3522// ** Marginal Power and Total Power Metrics **
3523//
3524// The Marginal Power Metric is the power difference between sleeping and staying awake
3525// to be a Sleep Proxy Server.
3526//
3527// The Total Power Metric is the total power consumption when being Sleep Proxy Server.
3528//
3529// The Power Metrics use a logarithmic decibel scale, computed as ten times the
3530// base 10 logarithm of the (approximate) power in microwatts:
3531//
3532//   Power Metric = log10(uW) * 10
3533//
3534// Higher values indicate higher power consumption. Example values:
3535//
3536// 10 =  10 uW
3537// 20 = 100 uW
3538// 30 =   1 mW
3539// 60 =   1 W
3540// 90 =   1 kW
3541
3542typedef enum
3543{
3544    mDNSSleepProxyMetric_Dedicated          = 20,
3545    mDNSSleepProxyMetric_PrimaryHardware    = 30,
3546    mDNSSleepProxyMetric_PrimarySoftware    = 40,
3547    mDNSSleepProxyMetric_SecondaryHardware  = 50,
3548    mDNSSleepProxyMetric_SecondarySoftware  = 60,
3549    mDNSSleepProxyMetric_IncidentalHardware = 70,
3550    mDNSSleepProxyMetric_IncidentalSoftware = 80
3551} mDNSSleepProxyMetric;
3552
3553typedef enum
3554{
3555    mDNS_NoWake        = 0, // System does not support Wake on LAN
3556    mDNS_WakeOnAC      = 1, // System supports Wake on LAN when connected to AC power only
3557    mDNS_WakeOnBattery = 2  // System supports Wake on LAN on battery
3558} mDNSWakeForNetworkAccess;
3559
3560extern void mDNSCoreBeSleepProxyServer_internal(mDNS *const m, mDNSu8 sps, mDNSu8 port, mDNSu8 marginalpower, mDNSu8 totpower, mDNSu8 features);
3561#define mDNSCoreBeSleepProxyServer(M,S,P,MP,TP,F)                       \
3562    do { mDNS_Lock(m); mDNSCoreBeSleepProxyServer_internal((M),(S),(P),(MP),(TP),(F)); mDNS_Unlock(m); } while(0)
3563
3564extern void FindSPSInCache(mDNS *const m, const DNSQuestion *const q, const CacheRecord *sps[3]);
3565#define PrototypeSPSName(X) ((X)[0] >= 11 && (X)[3] == '-' && (X)[ 4] == '9' && (X)[ 5] == '9' && \
3566                             (X)[6] == '-' && (X)[ 7] == '9' && (X)[ 8] == '9' && \
3567                             (X)[9] == '-' && (X)[10] == '9' && (X)[11] == '9'    )
3568#define ValidSPSName(X) ((X)[0] >= 5 && mDNSIsDigit((X)[1]) && mDNSIsDigit((X)[2]) && mDNSIsDigit((X)[4]) && mDNSIsDigit((X)[5]))
3569#define SPSMetric(X) (!ValidSPSName(X) || PrototypeSPSName(X) ? 1000000 : \
3570                      ((X)[1]-'0') * 100000 + ((X)[2]-'0') * 10000 + ((X)[4]-'0') * 1000 + ((X)[5]-'0') * 100 + ((X)[7]-'0') * 10 + ((X)[8]-'0'))
3571#define LocalSPSMetric(X) ( (X)->SPSType * 10000 + (X)->SPSPortability * 100 + (X)->SPSMarginalPower)
3572#define SPSFeatures(X) ((X)[0] >= 13 && (X)[12] =='.' ? ((X)[13]-'0') : 0 )
3573
3574#define MD5_DIGEST_LENGTH   16          /* digest length in bytes */
3575#define MD5_BLOCK_BYTES     64          /* block size in bytes */
3576#define MD5_BLOCK_LONG       (MD5_BLOCK_BYTES / sizeof(mDNSu32))
3577
3578typedef struct MD5state_st
3579{
3580    mDNSu32 A,B,C,D;
3581    mDNSu32 Nl,Nh;
3582    mDNSu32 data[MD5_BLOCK_LONG];
3583    int num;
3584} MD5_CTX;
3585
3586extern int MD5_Init(MD5_CTX *c);
3587extern int MD5_Update(MD5_CTX *c, const void *data, unsigned long len);
3588extern int MD5_Final(unsigned char *md, MD5_CTX *c);
3589
3590// ***************************************************************************
3591#if 0
3592#pragma mark -
3593#pragma mark - Compile-Time assertion checks
3594#endif
3595
3596// Some C compiler cleverness. We can make the compiler check certain things for
3597// us, and report compile-time errors if anything is wrong. The usual way to do
3598// this would be to use a run-time "if" statement, but then you don't find out
3599// what's wrong until you run the software. This way, if the assertion condition
3600// is false, the array size is negative, and the complier complains immediately.
3601
3602struct CompileTimeAssertionChecks_mDNS
3603{
3604    // Check that the compiler generated our on-the-wire packet format structure definitions
3605    // properly packed, without adding padding bytes to align fields on 32-bit or 64-bit boundaries.
3606    char assert0[(sizeof(rdataSRV)         == 262                          ) ? 1 : -1];
3607    char assert1[(sizeof(DNSMessageHeader) ==  12                          ) ? 1 : -1];
3608    char assert2[(sizeof(DNSMessage)       ==  12+AbsoluteMaxDNSMessageData) ? 1 : -1];
3609    char assert3[(sizeof(mDNSs8)           ==   1                          ) ? 1 : -1];
3610    char assert4[(sizeof(mDNSu8)           ==   1                          ) ? 1 : -1];
3611    char assert5[(sizeof(mDNSs16)          ==   2                          ) ? 1 : -1];
3612    char assert6[(sizeof(mDNSu16)          ==   2                          ) ? 1 : -1];
3613    char assert7[(sizeof(mDNSs32)          ==   4                          ) ? 1 : -1];
3614    char assert8[(sizeof(mDNSu32)          ==   4                          ) ? 1 : -1];
3615    char assert9[(sizeof(mDNSOpaque16)     ==   2                          ) ? 1 : -1];
3616    char assertA[(sizeof(mDNSOpaque32)     ==   4                          ) ? 1 : -1];
3617    char assertB[(sizeof(mDNSOpaque128)    ==  16                          ) ? 1 : -1];
3618    char assertC[(sizeof(CacheRecord  )    ==  sizeof(CacheGroup)          ) ? 1 : -1];
3619    char assertD[(sizeof(int)              >=  4                           ) ? 1 : -1];
3620    char assertE[(StandardAuthRDSize       >=  256                         ) ? 1 : -1];
3621    char assertF[(sizeof(EthernetHeader)   ==   14                         ) ? 1 : -1];
3622    char assertG[(sizeof(ARP_EthIP     )   ==   28                         ) ? 1 : -1];
3623    char assertH[(sizeof(IPv4Header    )   ==   20                         ) ? 1 : -1];
3624    char assertI[(sizeof(IPv6Header    )   ==   40                         ) ? 1 : -1];
3625    char assertJ[(sizeof(IPv6NDP       )   ==   24                         ) ? 1 : -1];
3626    char assertK[(sizeof(UDPHeader     )   ==    8                         ) ? 1 : -1];
3627    char assertL[(sizeof(IKEHeader     )   ==   28                         ) ? 1 : -1];
3628    char assertM[(sizeof(TCPHeader     )   ==   20                         ) ? 1 : -1];
3629	char assertN[(sizeof(rdataOPT)		   ==   24                         ) ? 1 : -1];
3630	char assertO[(sizeof(rdataRRSig)	   ==   20                         ) ? 1 : -1];
3631	char assertP[(sizeof(PCPMapRequest)    ==   60                         ) ? 1 : -1];
3632	char assertQ[(sizeof(PCPMapReply)      ==   60                         ) ? 1 : -1];
3633
3634
3635    // Check our structures are reasonable sizes. Including overly-large buffers, or embedding
3636    // other overly-large structures instead of having a pointer to them, can inadvertently
3637    // cause structure sizes (and therefore memory usage) to balloon unreasonably.
3638    char sizecheck_RDataBody           [(sizeof(RDataBody)            ==   264) ? 1 : -1];
3639    char sizecheck_ResourceRecord      [(sizeof(ResourceRecord)       <=    72) ? 1 : -1];
3640    char sizecheck_AuthRecord          [(sizeof(AuthRecord)           <=  1208) ? 1 : -1];
3641    char sizecheck_CacheRecord         [(sizeof(CacheRecord)          <=   232) ? 1 : -1];
3642    char sizecheck_CacheGroup          [(sizeof(CacheGroup)           <=   232) ? 1 : -1];
3643    char sizecheck_DNSQuestion         [(sizeof(DNSQuestion)          <=  1168) ? 1 : -1];
3644
3645    char sizecheck_ZoneData            [(sizeof(ZoneData)             <=  2000) ? 1 : -1];
3646    char sizecheck_NATTraversalInfo    [(sizeof(NATTraversalInfo)     <=   200) ? 1 : -1];
3647    char sizecheck_HostnameInfo        [(sizeof(HostnameInfo)         <=  3050) ? 1 : -1];
3648    char sizecheck_DNSServer           [(sizeof(DNSServer)            <=   330) ? 1 : -1];
3649    char sizecheck_NetworkInterfaceInfo[(sizeof(NetworkInterfaceInfo) <=  8400) ? 1 : -1];
3650    char sizecheck_ServiceRecordSet    [(sizeof(ServiceRecordSet)     <=  5540) ? 1 : -1];
3651    char sizecheck_DomainAuthInfo      [(sizeof(DomainAuthInfo)       <=  7888) ? 1 : -1];
3652#if APPLE_OSX_mDNSResponder
3653    char sizecheck_ClientTunnel        [(sizeof(ClientTunnel)         <=  1512) ? 1 : -1];
3654#endif
3655};
3656
3657// Routine to initialize device-info TXT record contents
3658mDNSu32 initializeDeviceInfoTXT(mDNS *m, mDNSu8 *ptr);
3659
3660#if APPLE_OSX_mDNSResponder
3661extern void D2D_start_advertising_interface(NetworkInterfaceInfo *interface);
3662extern void D2D_stop_advertising_interface(NetworkInterfaceInfo *interface);
3663extern void D2D_start_advertising_record(AuthRecord *ar);
3664extern void D2D_stop_advertising_record(AuthRecord *ar);
3665#else
3666#define D2D_start_advertising_interface(X)
3667#define D2D_stop_advertising_interface(X)
3668#define D2D_start_advertising_record(X)
3669#define D2D_stop_advertising_record(X)
3670#endif
3671
3672// ***************************************************************************
3673
3674#ifdef __cplusplus
3675}
3676#endif
3677
3678#endif
3679