xref: /openbsd-src/usr.sbin/ospfd/control.c (revision 99fd087599a8791921855f21bd7e36130f39aadc)
1 /*	$OpenBSD: control.c,v 1.45 2018/08/29 08:43:16 remi Exp $ */
2 
3 /*
4  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/stat.h>
21 #include <sys/socket.h>
22 #include <sys/un.h>
23 #include <errno.h>
24 #include <fcntl.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <unistd.h>
28 
29 #include "ospfd.h"
30 #include "ospf.h"
31 #include "ospfe.h"
32 #include "log.h"
33 #include "control.h"
34 
35 #define	CONTROL_BACKLOG	5
36 
37 struct ctl_conn	*control_connbyfd(int);
38 struct ctl_conn	*control_connbypid(pid_t);
39 void		 control_close(int);
40 
41 int
42 control_check(char *path)
43 {
44 	struct sockaddr_un	 sun;
45 	int			 fd;
46 
47 	bzero(&sun, sizeof(sun));
48 	sun.sun_family = AF_UNIX;
49 	strlcpy(sun.sun_path, path, sizeof(sun.sun_path));
50 
51 	if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
52 		log_warn("control_check: socket check");
53 		return (-1);
54 	}
55 
56 	if (connect(fd, (struct sockaddr *)&sun, sizeof(sun)) == 0) {
57 		log_warnx("control_check: socket in use");
58 		close(fd);
59 		return (-1);
60 	}
61 
62 	close(fd);
63 
64 	return (0);
65 }
66 
67 int
68 control_init(char *path)
69 {
70 	struct sockaddr_un	 sun;
71 	int			 fd;
72 	mode_t			 old_umask;
73 
74 	if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
75 	    0)) == -1) {
76 		log_warn("control_init: socket");
77 		return (-1);
78 	}
79 
80 	bzero(&sun, sizeof(sun));
81 	sun.sun_family = AF_UNIX;
82 	strlcpy(sun.sun_path, path, sizeof(sun.sun_path));
83 
84 	if (unlink(path) == -1)
85 		if (errno != ENOENT) {
86 			log_warn("control_init: unlink %s", path);
87 			close(fd);
88 			return (-1);
89 		}
90 
91 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
92 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
93 		log_warn("control_init: bind: %s", path);
94 		close(fd);
95 		umask(old_umask);
96 		return (-1);
97 	}
98 	umask(old_umask);
99 
100 	if (chmod(path, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) {
101 		log_warn("control_init: chmod");
102 		close(fd);
103 		(void)unlink(path);
104 		return (-1);
105 	}
106 
107 	return (fd);
108 }
109 
110 int
111 control_listen(void)
112 {
113 
114 	if (listen(control_state.fd, CONTROL_BACKLOG) == -1) {
115 		log_warn("control_listen: listen");
116 		return (-1);
117 	}
118 
119 	event_set(&control_state.ev, control_state.fd, EV_READ,
120 	    control_accept, NULL);
121 	event_add(&control_state.ev, NULL);
122 	evtimer_set(&control_state.evt, control_accept, NULL);
123 
124 	return (0);
125 }
126 
127 void
128 control_cleanup(char *path)
129 {
130 	if (path == NULL)
131 		return;
132 	event_del(&control_state.ev);
133 	event_del(&control_state.evt);
134 	unlink(path);
135 }
136 
137 /* ARGSUSED */
138 void
139 control_accept(int listenfd, short event, void *bula)
140 {
141 	int			 connfd;
142 	socklen_t		 len;
143 	struct sockaddr_un	 sun;
144 	struct ctl_conn		*c;
145 
146 	event_add(&control_state.ev, NULL);
147 	if ((event & EV_TIMEOUT))
148 		return;
149 
150 	len = sizeof(sun);
151 	if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len,
152 	    SOCK_CLOEXEC | SOCK_NONBLOCK)) == -1) {
153 		/*
154 		 * Pause accept if we are out of file descriptors, or
155 		 * libevent will haunt us here too.
156 		 */
157 		if (errno == ENFILE || errno == EMFILE) {
158 			struct timeval evtpause = { 1, 0 };
159 
160 			event_del(&control_state.ev);
161 			evtimer_add(&control_state.evt, &evtpause);
162 		} else if (errno != EWOULDBLOCK && errno != EINTR &&
163 		    errno != ECONNABORTED)
164 			log_warn("control_accept: accept");
165 		return;
166 	}
167 
168 	if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) {
169 		log_warn("control_accept");
170 		close(connfd);
171 		return;
172 	}
173 
174 	imsg_init(&c->iev.ibuf, connfd);
175 	c->iev.handler = control_dispatch_imsg;
176 	c->iev.events = EV_READ;
177 	event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events,
178 	    c->iev.handler, &c->iev);
179 	event_add(&c->iev.ev, NULL);
180 
181 	TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
182 }
183 
184 struct ctl_conn *
185 control_connbyfd(int fd)
186 {
187 	struct ctl_conn	*c;
188 
189 	TAILQ_FOREACH(c, &ctl_conns, entry) {
190 		if (c->iev.ibuf.fd == fd)
191 			break;
192 	}
193 
194 	return (c);
195 }
196 
197 struct ctl_conn *
198 control_connbypid(pid_t pid)
199 {
200 	struct ctl_conn	*c;
201 
202 	TAILQ_FOREACH(c, &ctl_conns, entry) {
203 		if (c->iev.ibuf.pid == pid)
204 			break;
205 	}
206 
207 	return (c);
208 }
209 
210 void
211 control_close(int fd)
212 {
213 	struct ctl_conn	*c;
214 
215 	if ((c = control_connbyfd(fd)) == NULL) {
216 		log_warn("control_close: fd %d: not found", fd);
217 		return;
218 	}
219 
220 	msgbuf_clear(&c->iev.ibuf.w);
221 	TAILQ_REMOVE(&ctl_conns, c, entry);
222 
223 	event_del(&c->iev.ev);
224 	close(c->iev.ibuf.fd);
225 
226 	/* Some file descriptors are available again. */
227 	if (evtimer_pending(&control_state.evt, NULL)) {
228 		evtimer_del(&control_state.evt);
229 		event_add(&control_state.ev, NULL);
230 	}
231 
232 	free(c);
233 }
234 
235 /* ARGSUSED */
236 void
237 control_dispatch_imsg(int fd, short event, void *bula)
238 {
239 	struct ctl_conn	*c;
240 	struct imsg	 imsg;
241 	ssize_t		 n;
242 	unsigned int	 ifidx;
243 	int		 verbose;
244 
245 	if ((c = control_connbyfd(fd)) == NULL) {
246 		log_warn("control_dispatch_imsg: fd %d: not found", fd);
247 		return;
248 	}
249 
250 	if (event & EV_READ) {
251 		if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) ||
252 		    n == 0) {
253 			control_close(fd);
254 			return;
255 		}
256 	}
257 	if (event & EV_WRITE) {
258 		if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) {
259 			control_close(fd);
260 			return;
261 		}
262 	}
263 
264 	for (;;) {
265 		if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) {
266 			control_close(fd);
267 			return;
268 		}
269 
270 		if (n == 0)
271 			break;
272 
273 		switch (imsg.hdr.type) {
274 		case IMSG_CTL_FIB_COUPLE:
275 		case IMSG_CTL_FIB_DECOUPLE:
276 			ospfe_fib_update(imsg.hdr.type);
277 			/* FALLTHROUGH */
278 		case IMSG_CTL_FIB_RELOAD:
279 		case IMSG_CTL_RELOAD:
280 			c->iev.ibuf.pid = imsg.hdr.pid;
281 			ospfe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0);
282 			break;
283 		case IMSG_CTL_KROUTE:
284 		case IMSG_CTL_KROUTE_ADDR:
285 		case IMSG_CTL_IFINFO:
286 			c->iev.ibuf.pid = imsg.hdr.pid;
287 			ospfe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid,
288 			    imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
289 			break;
290 		case IMSG_CTL_SHOW_INTERFACE:
291 			if (imsg.hdr.len == IMSG_HEADER_SIZE +
292 			    sizeof(ifidx)) {
293 				memcpy(&ifidx, imsg.data, sizeof(ifidx));
294 				ospfe_iface_ctl(c, ifidx);
295 				imsg_compose_event(&c->iev, IMSG_CTL_END, 0,
296 				    0, -1, NULL, 0);
297 			}
298 			break;
299 		case IMSG_CTL_SHOW_DATABASE:
300 		case IMSG_CTL_SHOW_DB_EXT:
301 		case IMSG_CTL_SHOW_DB_NET:
302 		case IMSG_CTL_SHOW_DB_RTR:
303 		case IMSG_CTL_SHOW_DB_SELF:
304 		case IMSG_CTL_SHOW_DB_SUM:
305 		case IMSG_CTL_SHOW_DB_ASBR:
306 		case IMSG_CTL_SHOW_DB_OPAQ:
307 		case IMSG_CTL_SHOW_RIB:
308 		case IMSG_CTL_SHOW_SUM:
309 			c->iev.ibuf.pid = imsg.hdr.pid;
310 			ospfe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid,
311 			    imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
312 			break;
313 		case IMSG_CTL_SHOW_NBR:
314 			ospfe_nbr_ctl(c);
315 			break;
316 		case IMSG_CTL_LOG_VERBOSE:
317 			if (imsg.hdr.len != IMSG_HEADER_SIZE +
318 			    sizeof(verbose))
319 				break;
320 
321 			/* forward to other processes */
322 			ospfe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid,
323 			    imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
324 			ospfe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid,
325 			    imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
326 
327 			memcpy(&verbose, imsg.data, sizeof(verbose));
328 			log_setverbose(verbose);
329 			break;
330 		default:
331 			log_debug("control_dispatch_imsg: "
332 			    "error handling imsg %d", imsg.hdr.type);
333 			break;
334 		}
335 		imsg_free(&imsg);
336 	}
337 
338 	imsg_event_add(&c->iev);
339 }
340 
341 int
342 control_imsg_relay(struct imsg *imsg)
343 {
344 	struct ctl_conn	*c;
345 
346 	if ((c = control_connbypid(imsg->hdr.pid)) == NULL)
347 		return (0);
348 
349 	return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid,
350 	    -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE));
351 }
352