1 /*
2  * Copyright (c) 2002-2019 Apple Inc. All rights reserved.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef __mDNSDebug_h
18 #define __mDNSDebug_h
19 
20 #include "mDNSFeatures.h"
21 
22 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
23 #include <os/log.h>
24 #endif
25 
26 // Set MDNS_DEBUGMSGS to 0 to optimize debugf() calls out of the compiled code
27 // Set MDNS_DEBUGMSGS to 1 to generate normal debugging messages
28 // Set MDNS_DEBUGMSGS to 2 to generate verbose debugging messages
29 // MDNS_DEBUGMSGS is normally set in the project options (or makefile) but can also be set here if desired
30 // (If you edit the file here to turn on MDNS_DEBUGMSGS while you're debugging some code, be careful
31 // not to accidentally check-in that change by mistake when you check in your other changes.)
32 
33 //#undef MDNS_DEBUGMSGS
34 //#define MDNS_DEBUGMSGS 2
35 
36 // Set MDNS_CHECK_PRINTF_STYLE_FUNCTIONS to 1 to enable extra GCC compiler warnings
37 // Note: You don't normally want to do this, because it generates a bunch of
38 // spurious warnings for the following custom extensions implemented by mDNS_vsnprintf:
39 //    warning: `#' flag used with `%s' printf format    (for %#s              -- pascal string format)
40 //    warning: repeated `#' flag in format              (for %##s             -- DNS name string format)
41 //    warning: double format, pointer arg (arg 2)       (for %.4a, %.16a, %#a -- IP address formats)
42 #define MDNS_CHECK_PRINTF_STYLE_FUNCTIONS 0
43 
44 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
45 typedef os_log_t mDNSLogCategory_t;
46 
47 typedef os_log_type_t mDNSLogLevel_t;
48 #define MDNS_LOG_FAULT      OS_LOG_TYPE_FAULT
49 #define MDNS_LOG_ERROR      OS_LOG_TYPE_ERROR
50 #define MDNS_LOG_WARNING    OS_LOG_TYPE_DEFAULT
51 #define MDNS_LOG_DEFAULT    OS_LOG_TYPE_DEFAULT
52 #define MDNS_LOG_INFO       OS_LOG_TYPE_DEFAULT
53 #define MDNS_LOG_DEBUG      OS_LOG_TYPE_DEBUG
54 #else
55 typedef const char * mDNSLogCategory_t;
56 typedef enum
57 {
58     MDNS_LOG_FAULT   = 1,
59     MDNS_LOG_ERROR   = 2,
60     MDNS_LOG_WARNING = 3,
61     MDNS_LOG_DEFAULT = 4,
62     MDNS_LOG_INFO    = 5,
63     MDNS_LOG_DEBUG   = 6
64 } mDNSLogLevel_t;
65 #endif
66 
67 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
68     extern os_log_t mDNSLogCategory_Default;
69     extern os_log_t mDNSLogCategory_mDNS;
70     extern os_log_t mDNSLogCategory_uDNS;
71     extern os_log_t mDNSLogCategory_SPS;
72     extern os_log_t mDNSLogCategory_XPC;
73     extern os_log_t mDNSLogCategory_Analytics;
74     extern os_log_t mDNSLogCategory_DNSSEC;
75 
76     #define MDNS_LOG_CATEGORY_DEFINITION(NAME)  mDNSLogCategory_ ## NAME
77 #else
78     #define MDNS_LOG_CATEGORY_DEFINITION(NAME)  # NAME
79 #endif
80 
81 #define MDNS_LOG_CATEGORY_DEFAULT   MDNS_LOG_CATEGORY_DEFINITION(Default)
82 #define MDNS_LOG_CATEGORY_MDNS      MDNS_LOG_CATEGORY_DEFINITION(mDNS)
83 #define MDNS_LOG_CATEGORY_UDNS      MDNS_LOG_CATEGORY_DEFINITION(uDNS)
84 #define MDNS_LOG_CATEGORY_SPS       MDNS_LOG_CATEGORY_DEFINITION(SPS)
85 #define MDNS_LOG_CATEGORY_XPC       MDNS_LOG_CATEGORY_DEFINITION(XPC)
86 #define MDNS_LOG_CATEGORY_ANALYTICS MDNS_LOG_CATEGORY_DEFINITION(Analytics)
87 #define MDNS_LOG_CATEGORY_DNSSEC    MDNS_LOG_CATEGORY_DEFINITION(DNSSEC)
88 
89 // Set this symbol to 1 to answer remote queries for our Address, and reverse mapping PTR
90 #define ANSWER_REMOTE_HOSTNAME_QUERIES 0
91 
92 // Set this symbol to 1 to do extra debug checks on malloc() and free()
93 // Set this symbol to 2 to write a log message for every malloc() and free()
94 // #define MDNS_MALLOC_DEBUGGING 1
95 
96 #if (MDNS_MALLOC_DEBUGGING > 0) && defined(WIN32)
97 #error "Malloc debugging does not yet work on Windows"
98 #endif
99 
100 //#define ForceAlerts 1
101 //#define LogTimeStamps 1
102 
103 // Developer-settings section ends here
104 
105 #if MDNS_CHECK_PRINTF_STYLE_FUNCTIONS
106 #define IS_A_PRINTF_STYLE_FUNCTION(F,A) __attribute__ ((format(printf,F,A)))
107 #else
108 #define IS_A_PRINTF_STYLE_FUNCTION(F,A)
109 #endif
110 
111 #ifdef __cplusplus
112 extern "C" {
113 #endif
114 
115 // Variable argument macro support. Use ANSI C99 __VA_ARGS__ where possible. Otherwise, use the next best thing.
116 
117 #if (defined(__GNUC__))
118     #if ((__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 2)))
119         #define MDNS_C99_VA_ARGS        1
120         #define MDNS_GNU_VA_ARGS        0
121     #else
122         #define MDNS_C99_VA_ARGS        0
123         #define MDNS_GNU_VA_ARGS        1
124     #endif
125     #define MDNS_HAS_VA_ARG_MACROS      1
126 #elif (_MSC_VER >= 1400) // Visual Studio 2005 and later
127     #define MDNS_C99_VA_ARGS            1
128     #define MDNS_GNU_VA_ARGS            0
129     #define MDNS_HAS_VA_ARG_MACROS      1
130 #elif (defined(__MWERKS__))
131     #define MDNS_C99_VA_ARGS            1
132     #define MDNS_GNU_VA_ARGS            0
133     #define MDNS_HAS_VA_ARG_MACROS      1
134 #else
135     #define MDNS_C99_VA_ARGS            1
136     #define MDNS_GNU_VA_ARGS            0
137     #define MDNS_HAS_VA_ARG_MACROS      1
138 #endif
139 
140 #if (MDNS_HAS_VA_ARG_MACROS)
141     #if (MDNS_C99_VA_ARGS)
142         #define MDNS_LOG_DEFINITION(LEVEL, ...) \
143             do { if (mDNS_LoggingEnabled) LogMsgWithLevel(MDNS_LOG_CATEGORY_DEFAULT, LEVEL, __VA_ARGS__); } while (0)
144 
145         #define debug_noop(...)   do {} while(0)
146         #define LogMsg(...)       LogMsgWithLevel(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, __VA_ARGS__)
147         #define LogOperation(...) MDNS_LOG_DEFINITION(MDNS_LOG_INFO,  __VA_ARGS__)
148         #define LogSPS(...)       MDNS_LOG_DEFINITION(MDNS_LOG_INFO,  __VA_ARGS__)
149         #define LogInfo(...)      MDNS_LOG_DEFINITION(MDNS_LOG_INFO,  __VA_ARGS__)
150         #define LogDebug(...)     MDNS_LOG_DEFINITION(MDNS_LOG_DEBUG, __VA_ARGS__)
151     #elif (MDNS_GNU_VA_ARGS)
152         #define MDNS_LOG_DEFINITION(LEVEL, ARGS...) \
153             do { if (mDNS_LoggingEnabled) LogMsgWithLevel(MDNS_LOG_CATEGORY_DEFAULT, LEVEL, ARGS); } while (0)
154 
155         #define debug_noop(ARGS...)   do {} while (0)
156         #define LogMsg(ARGS... )      LogMsgWithLevel(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_DEFAULT, ARGS)
157         #define LogOperation(ARGS...) MDNS_LOG_DEFINITION(MDNS_LOG_INFO,  ARGS)
158         #define LogSPS(ARGS...)       MDNS_LOG_DEFINITION(MDNS_LOG_INFO,  ARGS)
159         #define LogInfo(ARGS...)      MDNS_LOG_DEFINITION(MDNS_LOG_INFO,  ARGS)
160         #define LogDebug(ARGS...)     MDNS_LOG_DEFINITION(MDNS_LOG_DEBUG, ARGS)
161     #else
162         #error "Unknown variadic macros"
163     #endif
164 #else
165 // If your platform does not support variadic macros, you need to define the following variadic functions.
166 // See mDNSShared/mDNSDebug.c for sample implementation
167     #define debug_noop 1 ? (void)0 : (void)
168     #define LogMsg LogMsg_
169     #define LogOperation (mDNS_LoggingEnabled == 0) ? ((void)0) : LogOperation_
170     #define LogSPS       (mDNS_LoggingEnabled == 0) ? ((void)0) : LogSPS_
171     #define LogInfo      (mDNS_LoggingEnabled == 0) ? ((void)0) : LogInfo_
172     #define LogDebug     (mDNS_LoggingEnabled == 0) ? ((void)0) : LogDebug_
173 extern void LogMsg_(const char *format, ...)       IS_A_PRINTF_STYLE_FUNCTION(1,2);
174 extern void LogOperation_(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2);
175 extern void LogSPS_(const char *format, ...)       IS_A_PRINTF_STYLE_FUNCTION(1,2);
176 extern void LogInfo_(const char *format, ...)      IS_A_PRINTF_STYLE_FUNCTION(1,2);
177 extern void LogDebug_(const char *format, ...)     IS_A_PRINTF_STYLE_FUNCTION(1,2);
178 #endif
179 
180 
181 #if MDNS_DEBUGMSGS
182 #define debugf debugf_
183 extern void debugf_(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2);
184 #else
185 #define debugf debug_noop
186 #endif
187 
188 #if MDNS_DEBUGMSGS > 1
189 #define verbosedebugf verbosedebugf_
190 extern void verbosedebugf_(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2);
191 #else
192 #define verbosedebugf debug_noop
193 #endif
194 
195 extern int mDNS_LoggingEnabled;
196 extern int mDNS_PacketLoggingEnabled;
197 extern int mDNS_McastLoggingEnabled;
198 extern int mDNS_McastTracingEnabled;
199 extern int mDNS_DebugMode;          // If non-zero, LogMsg() writes to stderr instead of syslog
200 extern const char ProgramName[];
201 
202 extern void LogMsgWithLevel(mDNSLogCategory_t category, mDNSLogLevel_t level, const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(3,4);
203 // LogMsgNoIdent needs to be fixed so that it logs without the ident prefix like it used to
204 // (or completely overhauled to use the new "log to a separate file" facility)
205 #define LogMsgNoIdent LogMsg
206 
207 #if APPLE_OSX_mDNSResponder
208 extern void LogFatalError(const char *format, ...);
209 #else
210 #define LogFatalError LogMsg
211 #endif
212 
213 #if MDNS_MALLOC_DEBUGGING >= 1
214 extern void *mallocL(const char *msg, mDNSu32 size);
215 extern void *callocL(const char *msg, mDNSu32 size);
216 extern void freeL(const char *msg, void *x);
217 #if APPLE_OSX_mDNSResponder
218 extern void LogMemCorruption(const char *format, ...);
219 #else
220 #define LogMemCorruption LogMsg
221 #endif
222 #else
223 #define mallocL(MSG, SIZE) malloc(SIZE)
224 #define callocL(MSG, SIZE) calloc(1, SIZE)
225 #define freeL(MSG, PTR) free(PTR)
226 #endif
227 
228 #ifdef __cplusplus
229 }
230 #endif
231 
232 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
233 /** @brief Write a log message to system's log storage(memory or disk).
234  *
235  *  On Apple platform, os_log() will be called to log a message.
236  *
237  *  @param CATEGORY         A custom log object previously created by the os_log_create function, and such an object is
238  *                          used to specify "subsystem" and "category". For mDNSResponder, the subsystem should always
239  *                          be set to "com.apple.mDNSResponder"; and the category is used for categorization and
240  *                          filtering of related log messages within the subsystem’s settings. We have 4 categories that
241  *                          are pre-defined: MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_CATEGORY_MDNS, MDNS_LOG_CATEGORY_UDNS,
242  *                          MDNS_LOG_CATEGORY_SPS. If these categories are not enough, use os_log_create to create more.
243  *
244  *  @param LEVEL            The log level that determines the importance of the message. The levels are, in order of
245  *                          decreasing importance:
246  *                              MDNS_LOG_FAULT      Fault-level messages are intended for capturing system-level errors
247  *                                                  that are critical to the system. They are always saved in the data store.
248  *                              MDNS_LOG_ERROR      Error-level messages are intended for reporting process-level errors
249  *                                                  that are unexpected and incorrect during the normal operation. They
250  *                                                  are always saved in the data store.
251  *                              MDNS_LOG_WARNING    Warning-level messages are intended for capturing unexpected and
252  *                                                  possible incorrect behavior that might be used later to root cause
253  *                                                  an error or fault. They are are initially stored in memory buffers
254  *                                                  and then moved to a data store.
255  *                              MDNS_LOG_DEFAULT    Default-level messages are intended for reporting things that might
256  *                                                  result a failure. They are are initially stored in memory buffers
257  *                                                  and then moved to a data store.
258  *                              MDNS_LOG_INFO       Info-level messages are intended for capturing information that may
259  *                                                  be helpful, but isn’t essential, for troubleshooting errors. They
260  *                                                  are initially stored in memory buffers, but will only be moved into
261  *                                                  data store when faults and, optionally, errors occur.
262  *                              MDNS_LOG_DEBUG      Debug-level messages are intended for information that may be useful
263  *                                                  during development or while troubleshooting a specific problem, Debug
264  *                                                  logging should not be used in shipping software. They are only
265  *                                                  captured in memory when debug logging is enabled through a
266  *                                                  configuration change.
267  *
268  *  @param FORMAT           A constant string or format string that produces a human-readable log message. The format
269  *                          string follows the IEEE printf specification, besides the following customized format specifiers:
270  *                              %{mdnsresponder:domain_name}.*P     the pointer to a DNS lable sequence
271  *                              %{mdnsresponder:ip_addr}.20P        the pointer to a mDNSAddr variable
272  *                              %{network:in_addr}.4P               the pointer to a mDNSv4Addr variable
273  *                              %{network:in6_addr}.16P             the pointer to a mDNSv6Addr variable
274  *                              %{mdnsresponder:mac_addr}.6P        the pointer to a 6-byte-length MAC address
275  *
276  *  @param ...              The parameter list that will be formated by the format string. Note that if the customized
277  *                          format specifiers are used and the data length is not specified in the format string, the
278  *                          size should be listed before the pointer to the data, for example:
279  *                              "%{mdnsresponder:domain_name}.*P", (name ? (int)DomainNameLength((const domainname *)name) : 0), <the pointer to a DNS label sequence>
280  *
281  */
282     #define LogRedact(CATEGORY, LEVEL, FORMAT, ...) os_log_with_type(CATEGORY, LEVEL, FORMAT, ## __VA_ARGS__)
283 #else
284     #if (MDNS_HAS_VA_ARG_MACROS)
285         #if (MDNS_C99_VA_ARGS)
286             #define LogRedact(CATEGORY, LEVEL, ...) \
287                 do { if (mDNS_LoggingEnabled) LogMsgWithLevel(CATEGORY, LEVEL, __VA_ARGS__); } while (0)
288         #elif (MDNS_GNU_VA_ARGS)
289             #define LogRedact(CATEGORY, LEVEL, ARGS...) \
290                 do { if (mDNS_LoggingEnabled) LogMsgWithLevel(CATEGORY, LEVEL, ARGS); } while (0)
291         #else
292             #error "Unknown variadic macros"
293         #endif
294     #else
295         #define LogRedact      (mDNS_LoggingEnabled == 0) ? ((void)0) : LogRedact_
296         extern void LogRedact_(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2);
297     #endif
298 #endif // MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
299 
300 // The followings are the customized log specifier defined in os_log. For compatibility, we have to define it when it is
301 // not on the Apple platform, for example, the Posix platform. The keyword "public" or "private" is used to control whether
302 // the content would be redacted when the redaction is turned on: "public" means the content will always be printed;
303 // "private" means the content will be printed as <mask.hash: '<The hashed string from binary data>'> if the redaction is turned on,
304 // only when the redaction is turned off, the content will be printed as what it should be. Note that the hash performed
305 // to the data is a salted hashing transformation, and the salt is generated randomly on a per-process basis, meaning
306 // that hashes cannot be correlated across processes or devices.
307 
308 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
309     #define PUB_S "%{public}s"
310     #define PRI_S "%{private, mask.hash}s"
311 #else
312     #define PUB_S "%s"
313     #define PRI_S PUB_S
314 #endif
315 
316 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
317     #define PUB_DM_NAME "%{public, mdnsresponder:domain_name}.*P"
318     #define PRI_DM_NAME "%{private, mask.hash, mdnsresponder:domain_name}.*P"
319     // When DM_NAME_PARAM is used, the file where the function is defined must include DNSEmbeddedAPI.h
320     #define DM_NAME_PARAM(name) ((name) ? ((int)DomainNameLength((name))) : 0), (name)
321 #else
322     #define PUB_DM_NAME "%##s"
323     #define PRI_DM_NAME PUB_DM_NAME
324     #define DM_NAME_PARAM(name) (name)
325 #endif
326 
327 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
328     #define PUB_IP_ADDR "%{public, mdnsresponder:ip_addr}.20P"
329     #define PRI_IP_ADDR "%{private, mask.hash, mdnsresponder:ip_addr}.20P"
330 
331     #define PUB_IPv4_ADDR "%{public, network:in_addr}.4P"
332     #define PRI_IPv4_ADDR "%{private, mask.hash, network:in_addr}.4P"
333 
334     #define PUB_IPv6_ADDR "%{public, network:in6_addr}.16P"
335     #define PRI_IPv6_ADDR "%{private, mask.hash, network:in6_addr}.16P"
336 #else
337     #define PUB_IP_ADDR "%#a"
338     #define PRI_IP_ADDR PUB_IP_ADDR
339 
340     #define PUB_IPv4_ADDR "%.4a"
341     #define PRI_IPv4_ADDR PUB_IPv4_ADDR
342 
343     #define PUB_IPv6_ADDR "%.16a"
344     #define PRI_IPv6_ADDR PUB_IPv6_ADDR
345 #endif
346 
347 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
348     #define PUB_MAC_ADDR "%{public, mdnsresponder:mac_addr}.6P"
349     #define PRI_MAC_ADDR "%{private, mask.hash, mdnsresponder:mac_addr}.6P"
350 #else
351     #define PUB_MAC_ADDR "%.6a"
352     #define PRI_MAC_ADDR PUB_MAC_ADDR
353 #endif
354 
355 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
356     #define PUB_DNSKEY "%{public, mdns:rd.dnskey}.*P"
357     #define PRI_DNSKEY "%{private, mask.hash, mdns:rd.dnskey}.*P"
358     #define DNSKEY_PARAM(rdata, rdata_length) (rdata_length), (rdata)
359 #else
360     #define PUB_DNSKEY "%p"
361     #define PRI_DNSKEY PUB_DNSKEY
362     #define DNSKEY_PARAM(rdata, rdata_length) (rdata)
363 #endif
364 
365 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
366     #define PUB_DS "%{public, mdns:rd.ds}.*P"
367     #define PRI_DS "%{private, mask.hash, mdns:rd.ds}.*P"
368     #define DS_PARAM(rdata, rdata_length) (rdata_length), (rdata)
369 #else
370     #define PUB_DS "%p"
371     #define PRI_DS PUB_DS
372     #define DS_PARAM(rdata, rdata_length) (rdata)
373 #endif
374 
375 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
376     #define PUB_NSEC "%{public, mdns:rd.nsec}.*P"
377     #define PRI_NSEC "%{private, mask.hash, mdns:rd.nsec}.*P"
378     #define NSEC_PARAM(rdata, rdata_length) (rdata_length), (rdata)
379 #else
380     #define PUB_NSEC "%p"
381     #define PRI_NSEC PUB_NSEC
382     #define NSEC_PARAM(rdata, rdata_length) (rdata)
383 #endif
384 
385 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
386     #define PUB_NSEC3 "%{public, mdns:rd.nsec3}.*P"
387     #define PRI_NSEC3 "%{private, mask.hash, mdns:rd.nsec3}.*P"
388     #define NSEC3_PARAM(rdata, rdata_length) (rdata_length), (rdata)
389 #else
390     #define PUB_NSEC3 "%p"
391     #define PRI_NSEC3 PUB_NSEC3
392     #define NSEC3_PARAM(rdata, rdata_length) (rdata)
393 #endif
394 
395 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
396     #define PUB_RRSIG "%{public, mdns:rd.rrsig}.*P"
397     #define PRI_RRSIG "%{private, mask.hash, mdns:rd.rrsig}.*P"
398     #define RRSIG_PARAM(rdata, rdata_length) (rdata_length), (rdata)
399 #else
400     #define PUB_RRSIG "%p"
401     #define PRI_RRSIG PUB_RRSIG
402     #define RRSIG_PARAM(rdata, rdata_length) (rdata)
403 #endif
404 
405 #if MDNSRESPONDER_SUPPORTS(APPLE, OS_LOG)
406     #define PUB_SVCB "%{public, mdns:rd.svcb}.*P"
407     #define PRI_SVCB "%{private, mask.hash, mdns:rd.svcb}.*P"
408     #define SVCB_PARAM(rdata, rdata_length) (rdata_length), (rdata)
409 #else
410     #define PUB_SVCB "%p"
411     #define PRI_SVCB PUB_SVCB
412     #define SVCB_PARAM(rdata, rdata_length) (rdata)
413 #endif
414 
415 extern void LogToFD(int fd, const char *format, ...);
416 
417 #endif // __mDNSDebug_h
418