xref: /openbsd/sbin/iked/control.c (revision 6f40fd34) 
1 /*	$OpenBSD: control.c,v 1.25 2017/01/17 22:10:55 krw 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 <net/if.h>
27 
28 #include <errno.h>
29 #include <event.h>
30 #include <fcntl.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <unistd.h>
34 #include <signal.h>
35 
36 #include "iked.h"
37 
38 #define	CONTROL_BACKLOG	5
39 
40 struct ctl_connlist ctl_conns;
41 
42 void
43 	 control_accept(int, short, void *);
44 struct ctl_conn
45 	*control_connbyfd(int);
46 void	 control_close(int, struct control_sock *);
47 void	 control_dispatch_imsg(int, short, void *);
48 void	 control_dispatch_parent(int, short, void *);
49 void	 control_imsg_forward(struct imsg *);
50 void	 control_run(struct privsep *, struct privsep_proc *, void *);
51 
52 static struct privsep_proc procs[] = {
53 	{ "parent",	PROC_PARENT, NULL }
54 };
55 
56 pid_t
57 control(struct privsep *ps, struct privsep_proc *p)
58 {
59 	return (proc_run(ps, p, procs, nitems(procs), control_run, NULL));
60 }
61 
62 void
63 control_run(struct privsep *ps, struct privsep_proc *p, void *arg)
64 {
65 	/*
66 	 * pledge in the control process:
67 	 * stdio - for malloc and basic I/O including events.
68 	 * cpath - for unlinking the control socket.
69 	 * unix - for the control socket.
70 	 */
71 	if (pledge("stdio cpath unix", NULL) == -1)
72 		fatal("pledge");
73 }
74 
75 int
76 control_init(struct privsep *ps, struct control_sock *cs)
77 {
78 	struct iked		*env = ps->ps_env;
79 	struct sockaddr_un	 sun;
80 	int			 fd;
81 	mode_t			 old_umask, mode;
82 
83 	if (cs->cs_name == NULL)
84 		return (0);
85 
86 	if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0)) == -1) {
87 		log_warn("%s: socket", __func__);
88 		return (-1);
89 	}
90 
91 	sun.sun_family = AF_UNIX;
92 	if (strlcpy(sun.sun_path, cs->cs_name,
93 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
94 		log_warn("%s: %s name too long", __func__, cs->cs_name);
95 		close(fd);
96 		return (-1);
97 	}
98 
99 	if (unlink(cs->cs_name) == -1)
100 		if (errno != ENOENT) {
101 			log_warn("%s: unlink %s", __func__, cs->cs_name);
102 			close(fd);
103 			return (-1);
104 		}
105 
106 	if (cs->cs_restricted) {
107 		old_umask = umask(S_IXUSR|S_IXGRP|S_IXOTH);
108 		mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH;
109 	} else {
110 		old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
111 		mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
112 	}
113 
114 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
115 		log_warn("%s: bind: %s", __func__, cs->cs_name);
116 		close(fd);
117 		(void)umask(old_umask);
118 		return (-1);
119 	}
120 	(void)umask(old_umask);
121 
122 	if (chmod(cs->cs_name, mode) == -1) {
123 		log_warn("%s: chmod", __func__);
124 		close(fd);
125 		(void)unlink(cs->cs_name);
126 		return (-1);
127 	}
128 
129 	cs->cs_fd = fd;
130 	cs->cs_env = env;
131 
132 	return (0);
133 }
134 
135 int
136 control_listen(struct control_sock *cs)
137 {
138 	if (cs->cs_name == NULL)
139 		return (0);
140 
141 	if (listen(cs->cs_fd, CONTROL_BACKLOG) == -1) {
142 		log_warn("%s: listen", __func__);
143 		return (-1);
144 	}
145 
146 	event_set(&cs->cs_ev, cs->cs_fd, EV_READ,
147 	    control_accept, cs);
148 	event_add(&cs->cs_ev, NULL);
149 	evtimer_set(&cs->cs_evt, control_accept, cs);
150 
151 	return (0);
152 }
153 
154 void
155 control_cleanup(struct control_sock *cs)
156 {
157 	if (cs->cs_name == NULL)
158 		return;
159 	event_del(&cs->cs_ev);
160 	event_del(&cs->cs_evt);
161 	(void)unlink(cs->cs_name);
162 }
163 
164 /* ARGSUSED */
165 void
166 control_accept(int listenfd, short event, void *arg)
167 {
168 	struct control_sock	*cs = arg;
169 	int			 connfd;
170 	socklen_t		 len;
171 	struct sockaddr_un	 sun;
172 	struct ctl_conn		*c;
173 
174 	event_add(&cs->cs_ev, NULL);
175 	if ((event & EV_TIMEOUT))
176 		return;
177 
178 	len = sizeof(sun);
179 	if ((connfd = accept4(listenfd,
180 	    (struct sockaddr *)&sun, &len, SOCK_NONBLOCK)) == -1) {
181 		/*
182 		 * Pause accept if we are out of file descriptors, or
183 		 * libevent will haunt us here too.
184 		 */
185 		if (errno == ENFILE || errno == EMFILE) {
186 			struct timeval evtpause = { 1, 0 };
187 
188 			event_del(&cs->cs_ev);
189 			evtimer_add(&cs->cs_evt, &evtpause);
190 		} else if (errno != EWOULDBLOCK && errno != EINTR &&
191 		    errno != ECONNABORTED)
192 			log_warn("%s: accept", __func__);
193 		return;
194 	}
195 
196 	if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) {
197 		log_warn("%s", __func__);
198 		close(connfd);
199 		return;
200 	}
201 
202 	imsg_init(&c->iev.ibuf, connfd);
203 	c->iev.handler = control_dispatch_imsg;
204 	c->iev.events = EV_READ;
205 	c->iev.data = cs;
206 	event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events,
207 	    c->iev.handler, c->iev.data);
208 	event_add(&c->iev.ev, NULL);
209 
210 	TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
211 }
212 
213 struct ctl_conn *
214 control_connbyfd(int fd)
215 {
216 	struct ctl_conn	*c;
217 
218 	TAILQ_FOREACH(c, &ctl_conns, entry) {
219 		if (c->iev.ibuf.fd == fd)
220 			break;
221 	}
222 
223 	return (c);
224 }
225 
226 void
227 control_close(int fd, struct control_sock *cs)
228 {
229 	struct ctl_conn	*c;
230 
231 	if ((c = control_connbyfd(fd)) == NULL) {
232 		log_warn("%s: fd %d: not found", __func__, fd);
233 		return;
234 	}
235 
236 	msgbuf_clear(&c->iev.ibuf.w);
237 	TAILQ_REMOVE(&ctl_conns, c, entry);
238 
239 	event_del(&c->iev.ev);
240 	close(c->iev.ibuf.fd);
241 
242 	/* Some file descriptors are available again. */
243 	if (evtimer_pending(&cs->cs_evt, NULL)) {
244 		evtimer_del(&cs->cs_evt);
245 		event_add(&cs->cs_ev, NULL);
246 	}
247 
248 	free(c);
249 }
250 
251 /* ARGSUSED */
252 void
253 control_dispatch_imsg(int fd, short event, void *arg)
254 {
255 	struct control_sock	*cs = arg;
256 	struct iked		*env = cs->cs_env;
257 	struct ctl_conn		*c;
258 	struct imsg		 imsg;
259 	int			 n, v;
260 
261 	if ((c = control_connbyfd(fd)) == NULL) {
262 		log_warn("%s: fd %d: not found", __func__, fd);
263 		return;
264 	}
265 
266 	if (event & EV_READ) {
267 		if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) ||
268 		    n == 0) {
269 			control_close(fd, cs);
270 			return;
271 		}
272 	}
273 	if (event & EV_WRITE) {
274 		if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) {
275 			control_close(fd, cs);
276 			return;
277 		}
278 	}
279 
280 	for (;;) {
281 		if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) {
282 			control_close(fd, cs);
283 			return;
284 		}
285 
286 		if (n == 0)
287 			break;
288 
289 		control_imsg_forward(&imsg);
290 
291 		switch (imsg.hdr.type) {
292 		case IMSG_CTL_NOTIFY:
293 			if (c->flags & CTL_CONN_NOTIFY) {
294 				log_debug("%s: "
295 				    "client requested notify more than once",
296 				    __func__);
297 				imsg_compose_event(&c->iev, IMSG_CTL_FAIL,
298 				    0, 0, -1, NULL, 0);
299 				break;
300 			}
301 			c->flags |= CTL_CONN_NOTIFY;
302 			break;
303 		case IMSG_CTL_VERBOSE:
304 			IMSG_SIZE_CHECK(&imsg, &v);
305 
306 			memcpy(&v, imsg.data, sizeof(v));
307 			log_setverbose(v);
308 
309 			proc_forward_imsg(&env->sc_ps, &imsg, PROC_PARENT, -1);
310 			break;
311 		case IMSG_CTL_RELOAD:
312 		case IMSG_CTL_RESET:
313 		case IMSG_CTL_COUPLE:
314 		case IMSG_CTL_DECOUPLE:
315 		case IMSG_CTL_ACTIVE:
316 		case IMSG_CTL_PASSIVE:
317 			proc_forward_imsg(&env->sc_ps, &imsg, PROC_PARENT, -1);
318 			break;
319 		default:
320 			log_debug("%s: error handling imsg %d",
321 			    __func__, imsg.hdr.type);
322 			break;
323 		}
324 		imsg_free(&imsg);
325 	}
326 
327 	imsg_event_add(&c->iev);
328 }
329 
330 void
331 control_imsg_forward(struct imsg *imsg)
332 {
333 	struct ctl_conn *c;
334 
335 	TAILQ_FOREACH(c, &ctl_conns, entry)
336 		if (c->flags & CTL_CONN_NOTIFY)
337 			imsg_compose_event(&c->iev, imsg->hdr.type,
338 			    0, imsg->hdr.pid, -1, imsg->data,
339 			    imsg->hdr.len - IMSG_HEADER_SIZE);
340 }
341