xref: /openbsd-src/sbin/iked/control.c (revision 0e59d0d19ca6a10a17663d531bcea1b99c1bfe09)
1 /*	$OpenBSD: control.c,v 1.45 2024/11/21 13:35:20 claudio Exp $	*/
2 
3 /*
4  * Copyright (c) 2010-2013 Reyk Floeter <reyk@openbsd.org>
5  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include <sys/queue.h>
21 #include <sys/stat.h>
22 #include <sys/socket.h>
23 #include <sys/un.h>
24 #include <sys/tree.h>
25 
26 #include <errno.h>
27 #include <event.h>
28 #include <fcntl.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <unistd.h>
32 #include <signal.h>
33 
34 #include "iked.h"
35 
36 #define	CONTROL_BACKLOG	5
37 
38 struct ctl_connlist ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns);
39 uint32_t ctl_peerid;
40 
41 void
42 	 control_accept(int, short, void *);
43 struct ctl_conn
44 	*control_connbyfd(int);
45 void	 control_close(int, struct control_sock *);
46 void	 control_dispatch_imsg(int, short, void *);
47 void	 control_imsg_forward(struct imsg *);
48 void	 control_imsg_forward_peerid(struct imsg *);
49 void	 control_run(struct privsep *, struct privsep_proc *, void *);
50 int	 control_dispatch_ikev2(int, struct privsep_proc *, struct imsg *);
51 int	 control_dispatch_ca(int, struct privsep_proc *, struct imsg *);
52 
53 static struct privsep_proc procs[] = {
54 	{ "parent",	PROC_PARENT, NULL },
55 	{ "ikev2",	PROC_IKEV2, control_dispatch_ikev2 },
56 	{ "ca",		PROC_CERT, control_dispatch_ca },
57 };
58 
59 void
60 control(struct privsep *ps, struct privsep_proc *p)
61 {
62 	proc_run(ps, p, procs, nitems(procs), control_run, NULL);
63 }
64 
65 void
66 control_run(struct privsep *ps, struct privsep_proc *p, void *arg)
67 {
68 	/*
69 	 * pledge in the control process:
70 	 * stdio - for malloc and basic I/O including events.
71 	 * unix - for the control socket.
72 	 */
73 	if (pledge("stdio unix recvfd", NULL) == -1)
74 		fatal("pledge");
75 }
76 
77 int
78 control_init(struct privsep *ps, struct control_sock *cs)
79 {
80 	struct iked		*env = iked_env;
81 	struct sockaddr_un	 s_un;
82 	int			 fd;
83 	mode_t			 old_umask, mode;
84 
85 	if (cs->cs_name == NULL)
86 		return (0);
87 
88 	if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0)) == -1) {
89 		log_warn("%s: socket", __func__);
90 		return (-1);
91 	}
92 
93 	s_un.sun_family = AF_UNIX;
94 	if (strlcpy(s_un.sun_path, cs->cs_name,
95 	    sizeof(s_un.sun_path)) >= sizeof(s_un.sun_path)) {
96 		log_warn("%s: %s name too long", __func__, cs->cs_name);
97 		close(fd);
98 		return (-1);
99 	}
100 
101 	if (unlink(cs->cs_name) == -1)
102 		if (errno != ENOENT) {
103 			log_warn("%s: unlink %s", __func__, cs->cs_name);
104 			close(fd);
105 			return (-1);
106 		}
107 
108 	if (cs->cs_restricted) {
109 		old_umask = umask(S_IXUSR|S_IXGRP|S_IXOTH);
110 		mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH;
111 	} else {
112 		old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
113 		mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
114 	}
115 
116 	if (bind(fd, (struct sockaddr *)&s_un, sizeof(s_un)) == -1) {
117 		log_warn("%s: bind: %s", __func__, cs->cs_name);
118 		close(fd);
119 		(void)umask(old_umask);
120 		return (-1);
121 	}
122 	(void)umask(old_umask);
123 
124 	if (chmod(cs->cs_name, mode) == -1) {
125 		log_warn("%s: chmod", __func__);
126 		close(fd);
127 		(void)unlink(cs->cs_name);
128 		return (-1);
129 	}
130 
131 	cs->cs_fd = fd;
132 	cs->cs_env = env;
133 
134 	return (0);
135 }
136 
137 int
138 control_listen(struct control_sock *cs)
139 {
140 	if (cs->cs_name == NULL)
141 		return (0);
142 
143 	if (listen(cs->cs_fd, CONTROL_BACKLOG) == -1) {
144 		log_warn("%s: listen", __func__);
145 		return (-1);
146 	}
147 
148 	event_set(&cs->cs_ev, cs->cs_fd, EV_READ,
149 	    control_accept, cs);
150 	event_add(&cs->cs_ev, NULL);
151 	evtimer_set(&cs->cs_evt, control_accept, cs);
152 
153 	return (0);
154 }
155 
156 void
157 control_accept(int listenfd, short event, void *arg)
158 {
159 	struct control_sock	*cs = arg;
160 	int			 connfd;
161 	socklen_t		 len;
162 	struct sockaddr_un	 s_un;
163 	struct ctl_conn		*c;
164 	struct ctl_conn		*other;
165 
166 	event_add(&cs->cs_ev, NULL);
167 	if ((event & EV_TIMEOUT))
168 		return;
169 
170 	len = sizeof(s_un);
171 	if ((connfd = accept4(listenfd,
172 	    (struct sockaddr *)&s_un, &len, SOCK_NONBLOCK)) == -1) {
173 		/*
174 		 * Pause accept if we are out of file descriptors, or
175 		 * libevent will haunt us here too.
176 		 */
177 		if (errno == ENFILE || errno == EMFILE) {
178 			struct timeval evtpause = { 1, 0 };
179 
180 			event_del(&cs->cs_ev);
181 			evtimer_add(&cs->cs_evt, &evtpause);
182 		} else if (errno != EWOULDBLOCK && errno != EINTR &&
183 		    errno != ECONNABORTED)
184 			log_warn("%s: accept", __func__);
185 		return;
186 	}
187 
188 	if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) {
189 		log_warn("%s", __func__);
190 		close(connfd);
191 		return;
192 	}
193 
194 	if (imsgbuf_init(&c->iev.ibuf, connfd) == -1) {
195 		log_warn("%s", __func__);
196 		close(connfd);
197 		free(c);
198 		return;
199 	}
200 	c->iev.handler = control_dispatch_imsg;
201 	c->iev.events = EV_READ;
202 	c->iev.data = cs;
203 	event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events,
204 	    c->iev.handler, c->iev.data);
205 	event_add(&c->iev.ev, NULL);
206 
207 	/* O(n^2), but n is small */
208 	c->peerid = ctl_peerid++;
209 	TAILQ_FOREACH(other, &ctl_conns, entry)
210 		if (c->peerid == other->peerid)
211 			c->peerid = ctl_peerid++;
212 
213 	TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
214 }
215 
216 struct ctl_conn *
217 control_connbyfd(int fd)
218 {
219 	struct ctl_conn	*c;
220 
221 	TAILQ_FOREACH(c, &ctl_conns, entry) {
222 		if (c->iev.ibuf.fd == fd)
223 			break;
224 	}
225 
226 	return (c);
227 }
228 
229 void
230 control_close(int fd, struct control_sock *cs)
231 {
232 	struct ctl_conn	*c;
233 
234 	if ((c = control_connbyfd(fd)) == NULL) {
235 		log_warn("%s: fd %d: not found", __func__, fd);
236 		return;
237 	}
238 
239 	imsgbuf_clear(&c->iev.ibuf);
240 	TAILQ_REMOVE(&ctl_conns, c, entry);
241 
242 	event_del(&c->iev.ev);
243 	close(c->iev.ibuf.fd);
244 
245 	/* Some file descriptors are available again. */
246 	if (evtimer_pending(&cs->cs_evt, NULL)) {
247 		evtimer_del(&cs->cs_evt);
248 		event_add(&cs->cs_ev, NULL);
249 	}
250 
251 	free(c);
252 }
253 
254 void
255 control_dispatch_imsg(int fd, short event, void *arg)
256 {
257 	struct control_sock	*cs = arg;
258 	struct iked		*env = cs->cs_env;
259 	struct ctl_conn		*c;
260 	struct imsg		 imsg;
261 	int			 n, v;
262 
263 	if ((c = control_connbyfd(fd)) == NULL) {
264 		log_warn("%s: fd %d: not found", __func__, fd);
265 		return;
266 	}
267 
268 	if (event & EV_READ) {
269 		if (imsgbuf_read(&c->iev.ibuf) != 1) {
270 			control_close(fd, cs);
271 			return;
272 		}
273 	}
274 	if (event & EV_WRITE) {
275 		if (imsgbuf_write(&c->iev.ibuf) == -1) {
276 			control_close(fd, cs);
277 			return;
278 		}
279 	}
280 
281 	for (;;) {
282 		if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) {
283 			control_close(fd, cs);
284 			return;
285 		}
286 
287 		if (n == 0)
288 			break;
289 
290 		control_imsg_forward(&imsg);
291 
292 		/* record peerid of connection for reply */
293 		imsg.hdr.peerid = c->peerid;
294 
295 		switch (imsg.hdr.type) {
296 		case IMSG_CTL_NOTIFY:
297 			if (c->flags & CTL_CONN_NOTIFY) {
298 				log_debug("%s: "
299 				    "client requested notify more than once",
300 				    __func__);
301 				imsg_compose_event(&c->iev, IMSG_CTL_FAIL,
302 				    0, 0, -1, NULL, 0);
303 				break;
304 			}
305 			c->flags |= CTL_CONN_NOTIFY;
306 			break;
307 		case IMSG_CTL_VERBOSE:
308 			IMSG_SIZE_CHECK(&imsg, &v);
309 
310 			memcpy(&v, imsg.data, sizeof(v));
311 			log_setverbose(v);
312 
313 			proc_forward_imsg(&env->sc_ps, &imsg, PROC_PARENT, -1);
314 			break;
315 		case IMSG_CTL_RELOAD:
316 		case IMSG_CTL_RESET:
317 		case IMSG_CTL_COUPLE:
318 		case IMSG_CTL_DECOUPLE:
319 		case IMSG_CTL_ACTIVE:
320 		case IMSG_CTL_PASSIVE:
321 			proc_forward_imsg(&env->sc_ps, &imsg, PROC_PARENT, -1);
322 			break;
323 		case IMSG_CTL_RESET_ID:
324 			proc_forward_imsg(&env->sc_ps, &imsg, PROC_IKEV2, -1);
325 			break;
326 		case IMSG_CTL_SHOW_SA:
327 		case IMSG_CTL_SHOW_STATS:
328 			proc_forward_imsg(&env->sc_ps, &imsg, PROC_IKEV2, -1);
329 			break;
330 		case IMSG_CTL_SHOW_CERTSTORE:
331 			proc_forward_imsg(&env->sc_ps, &imsg, PROC_CERT, -1);
332 			break;
333 		default:
334 			log_debug("%s: error handling imsg %d",
335 			    __func__, imsg.hdr.type);
336 			break;
337 		}
338 		imsg_free(&imsg);
339 	}
340 
341 	imsg_event_add(&c->iev);
342 }
343 
344 void
345 control_imsg_forward(struct imsg *imsg)
346 {
347 	struct ctl_conn *c;
348 
349 	TAILQ_FOREACH(c, &ctl_conns, entry)
350 		if (c->flags & CTL_CONN_NOTIFY)
351 			imsg_compose_event(&c->iev, imsg->hdr.type,
352 			    0, imsg->hdr.pid, -1, imsg->data,
353 			    imsg->hdr.len - IMSG_HEADER_SIZE);
354 }
355 
356 void
357 control_imsg_forward_peerid(struct imsg *imsg)
358 {
359 	struct ctl_conn *c;
360 
361 	TAILQ_FOREACH(c, &ctl_conns, entry)
362 		if (c->peerid == imsg->hdr.peerid)
363 			imsg_compose_event(&c->iev, imsg->hdr.type,
364 			    0, imsg->hdr.pid, -1, imsg->data,
365 			    imsg->hdr.len - IMSG_HEADER_SIZE);
366 }
367 
368 int
369 control_dispatch_ikev2(int fd, struct privsep_proc *p, struct imsg *imsg)
370 {
371 	switch (imsg->hdr.type) {
372 	case IMSG_CTL_SHOW_SA:
373 	case IMSG_CTL_SHOW_STATS:
374 		control_imsg_forward_peerid(imsg);
375 		return (0);
376 	default:
377 		break;
378 	}
379 
380 	return (-1);
381 }
382 
383 int
384 control_dispatch_ca(int fd, struct privsep_proc *p, struct imsg *imsg)
385 {
386 	switch (imsg->hdr.type) {
387 	case IMSG_CTL_SHOW_CERTSTORE:
388 		control_imsg_forward_peerid(imsg);
389 		return (0);
390 	default:
391 		break;
392 	}
393 
394 	return (-1);
395 }
396