xref: /openbsd-src/usr.sbin/ospf6d/control.c (revision ff0e7be1ebbcc809ea8ad2b6dafe215824da9e46)
1 /*	$OpenBSD: control.c,v 1.31 2023/03/08 04:43:14 guenther 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 "ospf6d.h"
30 #include "ospf6.h"
31 #include "ospfe.h"
32 #include "log.h"
33 #include "control.h"
34 
35 TAILQ_HEAD(ctl_conns, ctl_conn)	ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns);
36 
37 #define	CONTROL_BACKLOG	5
38 
39 struct ctl_conn	*control_connbyfd(int);
40 struct ctl_conn	*control_connbypid(pid_t);
41 void		 control_close(int);
42 
43 struct {
44 	struct event	ev;
45 	struct event	evt;
46 	int		fd;
47 } control_state;
48 
49 int
50 control_check(char *path)
51 {
52 	struct sockaddr_un	 sun;
53 	int			 fd;
54 
55 	bzero(&sun, sizeof(sun));
56 	sun.sun_family = AF_UNIX;
57 	strlcpy(sun.sun_path, path, sizeof(sun.sun_path));
58 
59 	if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
60 		log_warn("control_check: socket check");
61 		return (-1);
62 	}
63 
64 	if (connect(fd, (struct sockaddr *)&sun, sizeof(sun)) == 0) {
65 		log_warnx("control_check: socket in use");
66 		close(fd);
67 		return (-1);
68 	}
69 
70 	close(fd);
71 
72 	return (0);
73 }
74 
75 int
76 control_init(char *path)
77 {
78 	struct sockaddr_un	 sun;
79 	int			 fd;
80 	mode_t			 old_umask;
81 
82 	if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
83 	    0)) == -1) {
84 		log_warn("control_init: socket");
85 		return (-1);
86 	}
87 
88 	bzero(&sun, sizeof(sun));
89 	sun.sun_family = AF_UNIX;
90 	strlcpy(sun.sun_path, path, sizeof(sun.sun_path));
91 
92 	if (unlink(path) == -1)
93 		if (errno != ENOENT) {
94 			log_warn("control_init: unlink %s", path);
95 			close(fd);
96 			return (-1);
97 		}
98 
99 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
100 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
101 		log_warn("control_init: bind: %s", path);
102 		close(fd);
103 		umask(old_umask);
104 		return (-1);
105 	}
106 	umask(old_umask);
107 
108 	if (chmod(path, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) {
109 		log_warn("control_init: chmod");
110 		close(fd);
111 		(void)unlink(path);
112 		return (-1);
113 	}
114 
115 	return (fd);
116 }
117 
118 int
119 control_listen(int fd)
120 {
121 	control_state.fd = fd;
122 
123 	if (listen(control_state.fd, CONTROL_BACKLOG) == -1) {
124 		log_warn("control_listen: listen");
125 		return (-1);
126 	}
127 
128 	event_set(&control_state.ev, control_state.fd, EV_READ,
129 	    control_accept, NULL);
130 	event_add(&control_state.ev, NULL);
131 	evtimer_set(&control_state.evt, control_accept, NULL);
132 
133 	return (0);
134 }
135 
136 void
137 control_cleanup(void)
138 {
139 	event_del(&control_state.ev);
140 	event_del(&control_state.evt);
141 }
142 
143 void
144 control_accept(int listenfd, short event, void *bula)
145 {
146 	int			 connfd;
147 	socklen_t		 len;
148 	struct sockaddr_un	 sun;
149 	struct ctl_conn		*c;
150 
151 	event_add(&control_state.ev, NULL);
152 	if ((event & EV_TIMEOUT))
153 		return;
154 
155 	len = sizeof(sun);
156 	if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len,
157 	    SOCK_CLOEXEC | SOCK_NONBLOCK)) == -1) {
158 		/*
159 		 * Pause accept if we are out of file descriptors, or
160 		 * libevent will haunt us here too.
161 		 */
162 		if (errno == ENFILE || errno == EMFILE) {
163 			struct timeval evtpause = { 1, 0 };
164 
165 			event_del(&control_state.ev);
166 			evtimer_add(&control_state.evt, &evtpause);
167 		} else if (errno != EWOULDBLOCK && errno != EINTR &&
168 		    errno != ECONNABORTED)
169 			log_warn("control_accept: accept");
170 		return;
171 	}
172 
173 	if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) {
174 		log_warn("control_accept");
175 		close(connfd);
176 		return;
177 	}
178 
179 	imsg_init(&c->iev.ibuf, connfd);
180 	c->iev.handler = control_dispatch_imsg;
181 	c->iev.events = EV_READ;
182 	event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events,
183 	    c->iev.handler, &c->iev);
184 	event_add(&c->iev.ev, NULL);
185 
186 	TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
187 }
188 
189 struct ctl_conn *
190 control_connbyfd(int fd)
191 {
192 	struct ctl_conn	*c;
193 
194 	TAILQ_FOREACH(c, &ctl_conns, entry) {
195 		if (c->iev.ibuf.fd == fd)
196 			break;
197 	}
198 
199 	return (c);
200 }
201 
202 struct ctl_conn *
203 control_connbypid(pid_t pid)
204 {
205 	struct ctl_conn	*c;
206 
207 	TAILQ_FOREACH(c, &ctl_conns, entry) {
208 		if (c->iev.ibuf.pid == pid)
209 			break;
210 	}
211 
212 	return (c);
213 }
214 
215 void
216 control_close(int fd)
217 {
218 	struct ctl_conn	*c;
219 
220 	if ((c = control_connbyfd(fd)) == NULL) {
221 		log_warn("control_close: fd %d: not found", fd);
222 		return;
223 	}
224 
225 	msgbuf_clear(&c->iev.ibuf.w);
226 	TAILQ_REMOVE(&ctl_conns, c, entry);
227 
228 	event_del(&c->iev.ev);
229 	close(c->iev.ibuf.fd);
230 
231 	/* Some file descriptors are available again. */
232 	if (evtimer_pending(&control_state.evt, NULL)) {
233 		evtimer_del(&control_state.evt);
234 		event_add(&control_state.ev, NULL);
235 	}
236 
237 	free(c);
238 }
239 
240 void
241 control_dispatch_imsg(int fd, short event, void *bula)
242 {
243 	struct ctl_conn	*c;
244 	struct imsg	 imsg;
245 	ssize_t		 n;
246 	unsigned int	 ifidx;
247 	int		 verbose;
248 
249 	if ((c = control_connbyfd(fd)) == NULL) {
250 		log_warn("control_dispatch_imsg: fd %d: not found", fd);
251 		return;
252 	}
253 
254 	if (event & EV_READ) {
255 		if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) ||
256 		    n == 0) {
257 			control_close(fd);
258 			return;
259 		}
260 	}
261 	if (event & EV_WRITE) {
262 		if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) {
263 			control_close(fd);
264 			return;
265 		}
266 	}
267 
268 	for (;;) {
269 		if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) {
270 			control_close(fd);
271 			return;
272 		}
273 
274 		if (n == 0)
275 			break;
276 
277 		switch (imsg.hdr.type) {
278 		case IMSG_CTL_FIB_COUPLE:
279 		case IMSG_CTL_FIB_DECOUPLE:
280 			ospfe_fib_update(imsg.hdr.type);
281 			/* FALLTHROUGH */
282 		case IMSG_CTL_RELOAD:
283 			c->iev.ibuf.pid = imsg.hdr.pid;
284 			ospfe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0);
285 			break;
286 		case IMSG_CTL_KROUTE:
287 		case IMSG_CTL_KROUTE_ADDR:
288 			c->iev.ibuf.pid = imsg.hdr.pid;
289 			ospfe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid,
290 			    imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
291 			break;
292 		case IMSG_CTL_SHOW_INTERFACE:
293 			if (imsg.hdr.len == IMSG_HEADER_SIZE +
294 			    sizeof(ifidx)) {
295 				memcpy(&ifidx, imsg.data, sizeof(ifidx));
296 				ospfe_iface_ctl(c, ifidx);
297 				imsg_compose_event(&c->iev, IMSG_CTL_END, 0,
298 				    0, -1, NULL, 0);
299 			}
300 			break;
301 		case IMSG_CTL_SHOW_DATABASE:
302 		case IMSG_CTL_SHOW_DB_EXT:
303 		case IMSG_CTL_SHOW_DB_LINK:
304 		case IMSG_CTL_SHOW_DB_NET:
305 		case IMSG_CTL_SHOW_DB_RTR:
306 		case IMSG_CTL_SHOW_DB_INTRA:
307 		case IMSG_CTL_SHOW_DB_SELF:
308 		case IMSG_CTL_SHOW_DB_SUM:
309 		case IMSG_CTL_SHOW_DB_ASBR:
310 		case IMSG_CTL_SHOW_RIB:
311 		case IMSG_CTL_SHOW_SUM:
312 			c->iev.ibuf.pid = imsg.hdr.pid;
313 			ospfe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid,
314 			    imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
315 			break;
316 		case IMSG_CTL_SHOW_NBR:
317 			ospfe_nbr_ctl(c);
318 			break;
319 		case IMSG_CTL_LOG_VERBOSE:
320 			if (imsg.hdr.len != IMSG_HEADER_SIZE +
321 			    sizeof(verbose))
322 				break;
323 
324 			/* forward to other processes */
325 			ospfe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid,
326 			    imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
327 			ospfe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid,
328 			    imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
329 
330 			memcpy(&verbose, imsg.data, sizeof(verbose));
331 			log_setverbose(verbose);
332 			break;
333 		default:
334 			log_debug("control_dispatch_imsg: "
335 			    "error handling imsg %d", imsg.hdr.type);
336 			break;
337 		}
338 		imsg_free(&imsg);
339 	}
340 
341 	imsg_event_add(&c->iev);
342 }
343 
344 int
345 control_imsg_relay(struct imsg *imsg)
346 {
347 	struct ctl_conn	*c;
348 
349 	if ((c = control_connbypid(imsg->hdr.pid)) == NULL)
350 		return (0);
351 
352 	return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid,
353 	    -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE));
354 }
355