1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 /*
26  * Copyright (c) 2013, 2015 by Delphix. All rights reserved.
27  * Copyright 2019 OmniOS Community Edition (OmniOSce) Association.
28  */
29 
30 #ifndef	_DHCPAGENT_IPC_H
31 #define	_DHCPAGENT_IPC_H
32 
33 #include <sys/socket.h>
34 #include <net/if.h>		/* LIFNAMSIZ */
35 #include <stddef.h>
36 #include <sys/types.h>
37 #include <sys/time.h>
38 #include <netinet/dhcp.h>
39 #include <dhcp_impl.h>
40 
41 /*
42  * dhcpagent_ipc.[ch] comprise the interface used to perform
43  * interprocess communication with the agent.  see dhcpagent_ipc.c for
44  * documentation on how to use the exported functions.
45  */
46 
47 #ifdef	__cplusplus
48 extern "C" {
49 #endif
50 
51 #define	DHCP_AGENT_PATH		"/sbin/dhcpagent"
52 #define	DHCP_IPC_LISTEN_BACKLOG	30
53 #define	IPPORT_DHCPAGENT	4999
54 #define	DHCP_IPC_MAX_WAIT	15	/* max seconds to wait to start agent */
55 
56 /*
57  * return values which should be used by programs which talk to the
58  * agent (for uniformity).
59  */
60 
61 #define	DHCP_EXIT_SUCCESS	0
62 #define	DHCP_EXIT_FAILURE	2
63 #define	DHCP_EXIT_BADARGS	3
64 #define	DHCP_EXIT_TIMEOUT	4
65 #define	DHCP_EXIT_SYSTEM	6
66 
67 /*
68  * opaque types for requests and replies.  users of this api do not
69  * need to understand their contents.
70  */
71 
72 typedef struct dhcp_ipc_request dhcp_ipc_request_t;
73 typedef struct dhcp_ipc_reply   dhcp_ipc_reply_t;
74 
75 /* payloads that can be passed in a request or reply */
76 
77 typedef enum {
78 	DHCP_TYPE_OPTION,
79 	DHCP_TYPE_STATUS,
80 	DHCP_TYPE_OPTNUM,
81 	DHCP_TYPE_NONE
82 } dhcp_data_type_t;
83 
84 /*
85  * requests that can be sent to the agent
86  *
87  * code in dhcpagent relies on the numeric values of these
88  * requests -- but there's no sane reason to change them anyway.
89  *
90  * If any commands are changed, added, or removed, see the ipc_typestr[]
91  * array in dhcpagent_ipc.c.
92  */
93 
94 typedef enum {
95 	DHCP_DROP,	DHCP_EXTEND,  DHCP_PING,    DHCP_RELEASE,
96 	DHCP_START,	DHCP_STATUS,  DHCP_INFORM,  DHCP_GET_TAG,
97 	DHCP_NIPC,	/* number of supported requests */
98 	DHCP_PRIMARY = 0x100,
99 	DHCP_V6 = 0x200
100 } dhcp_ipc_type_t;
101 
102 /* structure passed with the DHCP_GET_TAG request */
103 
104 typedef struct {
105 	uint_t		category;
106 	uint_t		code;
107 	uint_t		size;
108 } dhcp_optnum_t;
109 
110 #define	DHCP_IPC_CMD(type)	((type) & 0x00ff)
111 #define	DHCP_IPC_FLAGS(type)	((type) & 0xff00)
112 
113 /* special timeout values for dhcp_ipc_make_request() */
114 
115 #define	DHCP_IPC_WAIT_FOREVER	(-1)
116 #define	DHCP_IPC_WAIT_DEFAULT	(-2)
117 
118 /*
119  * errors that can be returned from the provided functions.
120  * note: keep in sync with dhcp_ipc_strerror()
121  */
122 
123 enum {
124 	/* System call errors must be kept contiguous */
125 	DHCP_IPC_SUCCESS,	DHCP_IPC_E_SOCKET,	DHCP_IPC_E_FCNTL,
126 	DHCP_IPC_E_READ,	DHCP_IPC_E_ACCEPT,	DHCP_IPC_E_CLOSE,
127 	DHCP_IPC_E_BIND,	DHCP_IPC_E_LISTEN,	DHCP_IPC_E_MEMORY,
128 	DHCP_IPC_E_CONNECT,	DHCP_IPC_E_WRITEV,	DHCP_IPC_E_POLL,
129 
130 	/* All others follow */
131 	DHCP_IPC_E_TIMEOUT,	DHCP_IPC_E_SRVFAILED,	DHCP_IPC_E_EOF,
132 	DHCP_IPC_E_INVIF,	DHCP_IPC_E_INT,		DHCP_IPC_E_PERM,
133 	DHCP_IPC_E_OUTSTATE,	DHCP_IPC_E_PEND,	DHCP_IPC_E_BOOTP,
134 	DHCP_IPC_E_CMD_UNKNOWN, DHCP_IPC_E_UNKIF,	DHCP_IPC_E_PROTO,
135 	DHCP_IPC_E_FAILEDIF,	DHCP_IPC_E_NOPRIMARY,	DHCP_IPC_E_DOWNIF,
136 	DHCP_IPC_E_NOIPIF,	DHCP_IPC_E_NOVALUE,	DHCP_IPC_E_RUNNING
137 };
138 
139 /*
140  * low-level public dhcpagent ipc functions -- these are for use by
141  * programs that need to communicate with the dhcpagent.  these will
142  * remain relatively stable.
143  */
144 
145 extern const char	*dhcp_ipc_strerror(int);
146 extern dhcp_ipc_request_t *dhcp_ipc_alloc_request(dhcp_ipc_type_t, const char *,
147 			    const void *, uint32_t, dhcp_data_type_t);
148 extern void		*dhcp_ipc_get_data(dhcp_ipc_reply_t *, size_t *,
149 			    dhcp_data_type_t *);
150 extern int		dhcp_ipc_make_request(dhcp_ipc_request_t *,
151 			    dhcp_ipc_reply_t **, int32_t);
152 extern const char	*dhcp_ipc_type_to_string(dhcp_ipc_type_t);
153 
154 /*
155  * high-level public dhcpagent ipc functions
156  */
157 
158 extern int		dhcp_ipc_getinfo(dhcp_optnum_t *, DHCP_OPT **, int32_t);
159 
160 /*
161  * private dhcpagent ipc "server side" functions -- these are only for
162  * use by dhcpagent(8) and are subject to change.
163  */
164 
165 extern int		dhcp_ipc_init(int *);
166 extern int		dhcp_ipc_accept(int, int *, int *);
167 extern int		dhcp_ipc_recv_request(int, dhcp_ipc_request_t **, int);
168 extern dhcp_ipc_reply_t	*dhcp_ipc_alloc_reply(dhcp_ipc_request_t *, int,
169 			    const void *, uint32_t, dhcp_data_type_t);
170 extern int		dhcp_ipc_send_reply(int, dhcp_ipc_reply_t *);
171 extern int		dhcp_ipc_close(int);
172 
173 /*
174  * values for if_state in the dhcp_status_t
175  *
176  * code in this library and dhcpagent rely on the numeric values of these
177  * requests -- but there's no sane reason to change them anyway.
178  */
179 
180 typedef enum {
181 	INIT,				/* nothing done yet */
182 	SELECTING,			/* sent DISCOVER, waiting for OFFERs */
183 	REQUESTING,			/* sent REQUEST, waiting for ACK/NAK */
184 	PRE_BOUND,			/* have ACK, setting up interface */
185 	BOUND,				/* have a valid lease */
186 	RENEWING,			/* have lease, but trying to renew */
187 	REBINDING,			/* have lease, but trying to rebind */
188 	INFORMATION,			/* sent INFORM, received ACK */
189 	INIT_REBOOT,			/* attempt to use cached ACK/Reply */
190 	ADOPTING,			/* attempting to adopt */
191 	INFORM_SENT,			/* sent INFORM, awaiting ACK */
192 	DECLINING,			/* sent v6 Decline, awaiting Reply */
193 	RELEASING,			/* sent v6 Release, awaiting Reply */
194 	DHCP_NSTATES			/* total number of states */
195 } DHCPSTATE;
196 
197 /* values for if_dflags in the dhcp_status_t */
198 
199 #define	DHCP_IF_PRIMARY		0x0100	/* interface is primary interface */
200 #define	DHCP_IF_BUSY		0x0200	/* asynchronous command pending */
201 #define	DHCP_IF_BOOTP		0x0400	/* interface is using bootp */
202 #define	DHCP_IF_REMOVED		0x0800	/* interface is going away */
203 #define	DHCP_IF_FAILED		0x1000	/* interface configuration problem */
204 #define	DHCP_IF_V6		0x2000	/* DHCPv6 interface */
205 
206 /*
207  * structure passed with the DHCP_STATUS replies
208  *
209  * when parsing a dhcp_status_t, `version' should always be checked
210  * if there is a need to access any fields which were not defined in
211  * version 1 of this structure.
212  *
213  * as new fields are added to the dhcp_status_t, they should be
214  * appended to the structure and the version number incremented.
215  */
216 
217 typedef struct dhcp_status {
218 	uint8_t		version;	/* version of this structure */
219 
220 	char		if_name[LIFNAMSIZ];
221 	DHCPSTATE	if_state;	/* state of interface; see above */
222 
223 	/*
224 	 * We use int64_t here so that the structure is the same in both
225 	 * 32 and 64-bit, since it is passed via IPC.
226 	 * Once everything that uses this is 64-bit, these could be changed
227 	 * to time_t.
228 	 */
229 	int64_t		if_began;	/* time lease began (absolute) */
230 	int64_t		if_t1;		/* renewing time (absolute) */
231 	int64_t		if_t2;		/* rebinding time (absolute) */
232 	int64_t		if_lease;	/* lease expiration time (absolute) */
233 
234 	uint16_t	if_dflags;	/* DHCP flags on this if; see above */
235 
236 	/*
237 	 * these three fields are initially zero, and get incremented
238 	 * as if_state goes from INIT -> BOUND (or INIT ->
239 	 * INFORMATION).  if and when the interface moves to the
240 	 * RENEWING state, these fields are reset, so they always
241 	 * either indicate the number of packets sent, received, and
242 	 * declined while obtaining the current lease (if BOUND), or
243 	 * the number of packets sent, received, and declined while
244 	 * attempting to obtain a future lease (if any other state).
245 	 */
246 
247 	uint32_t	if_sent;
248 	uint32_t	if_recv;
249 	uint32_t	if_bad_offers;
250 } dhcp_status_t;
251 
252 #define	DHCP_STATUS_VER		1	/* current version of dhcp_status_t */
253 #define	DHCP_STATUS_VER1_SIZE	(offsetof(dhcp_status_t, if_bad_offers) + \
254 				    sizeof (uint32_t))
255 
256 /*
257  * the remainder of this file contains implementation-specific
258  * artifacts which may change. note that a `dhcp_ipc_request_t' and a
259  * `dhcp_ipc_reply_t' are incomplete types as far as consumers of this
260  * api are concerned.  use these details at your own risk.
261  */
262 
263 typedef hrtime_t dhcp_ipc_id_t;
264 
265 /*
266  * note: the first 4 fields of the dhcp_ipc_request_t and dhcp_ipc_reply_t
267  *	 are intentionally identical; code in dhcpagent_ipc.c counts on it!
268  *
269  * we pack these structs to ensure that their lengths will be identical between
270  * 32-bit and 64-bit executables.
271  */
272 
273 #pragma pack(4)
274 
275 struct	dhcp_ipc_request {
276 	dhcp_ipc_type_t  message_type;	/* type of request */
277 	dhcp_ipc_id_t	 ipc_id;	/* per-socket unique request id */
278 	dhcp_data_type_t data_type;	/* type of payload */
279 	uint32_t	 data_length;	/* size of actual data in the buffer */
280 	char		 ifname[LIFNAMSIZ];
281 	int32_t		 timeout;	/* timeout in seconds */
282 	uchar_t		 buffer[1];	/* dynamically extended */
283 };
284 
285 struct	dhcp_ipc_reply {
286 	dhcp_ipc_type_t	 message_type;	/* same message type as request */
287 	dhcp_ipc_id_t	 ipc_id;	/* same id as request */
288 	dhcp_data_type_t data_type;	/* type of payload */
289 	uint32_t	 data_length;	/* size of actual data in the buffer */
290 	uint32_t	 return_code;	/* did the request succeed? */
291 	uchar_t		 buffer[1];	/* dynamically extended */
292 };
293 
294 #pragma pack()
295 
296 #define	DHCP_IPC_REPLY_SIZE	offsetof(dhcp_ipc_reply_t, buffer)
297 #define	DHCP_IPC_REQUEST_SIZE	offsetof(dhcp_ipc_request_t, buffer)
298 
299 #define	DHCP_IPC_DEFAULT_WAIT	120	/* seconds */
300 
301 #ifdef	__cplusplus
302 }
303 #endif
304 
305 #endif	/* _DHCPAGENT_IPC_H */
306