xref: /openbsd-src/usr.sbin/ldpd/control.c (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /*	$OpenBSD: control.c,v 1.14 2014/07/11 16:43:33 krw 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 "ldpd.h"
30 #include "ldp.h"
31 #include "ldpe.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 control_fd;
42 
43 int
44 control_init(void)
45 {
46 	struct sockaddr_un	 sun;
47 	int			 fd;
48 	mode_t			 old_umask;
49 
50 	if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
51 		log_warn("control_init: socket");
52 		return (-1);
53 	}
54 
55 	bzero(&sun, sizeof(sun));
56 	sun.sun_family = AF_UNIX;
57 	strlcpy(sun.sun_path, LDPD_SOCKET, sizeof(sun.sun_path));
58 
59 	if (unlink(LDPD_SOCKET) == -1)
60 		if (errno != ENOENT) {
61 			log_warn("control_init: unlink %s", LDPD_SOCKET);
62 			close(fd);
63 			return (-1);
64 		}
65 
66 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
67 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
68 		log_warn("control_init: bind: %s", LDPD_SOCKET);
69 		close(fd);
70 		umask(old_umask);
71 		return (-1);
72 	}
73 	umask(old_umask);
74 
75 	if (chmod(LDPD_SOCKET, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) {
76 		log_warn("control_init: chmod");
77 		close(fd);
78 		(void)unlink(LDPD_SOCKET);
79 		return (-1);
80 	}
81 
82 	session_socket_blockmode(fd, BM_NONBLOCK);
83 	control_fd = fd;
84 
85 	return (0);
86 }
87 
88 int
89 control_listen(void)
90 {
91 
92 	if (listen(control_fd, CONTROL_BACKLOG) == -1) {
93 		log_warn("control_listen: listen");
94 		return (-1);
95 	}
96 
97 	return (accept_add(control_fd, control_accept, NULL));
98 }
99 
100 void
101 control_cleanup(void)
102 {
103 	unlink(LDPD_SOCKET);
104 }
105 
106 /* ARGSUSED */
107 void
108 control_accept(int listenfd, short event, void *bula)
109 {
110 	int			 connfd;
111 	socklen_t		 len;
112 	struct sockaddr_un	 sun;
113 	struct ctl_conn		*c;
114 
115 	len = sizeof(sun);
116 	if ((connfd = accept(listenfd, (struct sockaddr *)&sun, &len)) == -1) {
117 		/*
118 		 * Pause accept if we are out of file descriptors, or
119 		 * libevent will haunt us here too.
120 		 */
121 		if (errno == ENFILE || errno == EMFILE)
122 			accept_pause();
123 		else if (errno != EWOULDBLOCK && errno != EINTR &&
124 		    errno != ECONNABORTED)
125 			log_warn("control_accept: accept");
126 		return;
127 	}
128 
129 	session_socket_blockmode(connfd, BM_NONBLOCK);
130 
131 	if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) {
132 		log_warn("control_accept");
133 		close(connfd);
134 		return;
135 	}
136 
137 	imsg_init(&c->iev.ibuf, connfd);
138 	c->iev.handler = control_dispatch_imsg;
139 	c->iev.events = EV_READ;
140 	event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events,
141 	    c->iev.handler, &c->iev);
142 	event_add(&c->iev.ev, NULL);
143 
144 	TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
145 }
146 
147 struct ctl_conn *
148 control_connbyfd(int fd)
149 {
150 	struct ctl_conn	*c;
151 
152 	for (c = TAILQ_FIRST(&ctl_conns); c != NULL && c->iev.ibuf.fd != fd;
153 	    c = TAILQ_NEXT(c, entry))
154 		;	/* nothing */
155 
156 	return (c);
157 }
158 
159 struct ctl_conn *
160 control_connbypid(pid_t pid)
161 {
162 	struct ctl_conn	*c;
163 
164 	for (c = TAILQ_FIRST(&ctl_conns); c != NULL && c->iev.ibuf.pid != pid;
165 	    c = TAILQ_NEXT(c, entry))
166 		;	/* nothing */
167 
168 	return (c);
169 }
170 
171 void
172 control_close(int fd)
173 {
174 	struct ctl_conn	*c;
175 
176 	if ((c = control_connbyfd(fd)) == NULL) {
177 		log_warn("control_close: fd %d: not found", fd);
178 		return;
179 	}
180 
181 	msgbuf_clear(&c->iev.ibuf.w);
182 	TAILQ_REMOVE(&ctl_conns, c, entry);
183 
184 	event_del(&c->iev.ev);
185 	close(c->iev.ibuf.fd);
186 	free(c);
187 	accept_unpause();
188 }
189 
190 /* ARGSUSED */
191 void
192 control_dispatch_imsg(int fd, short event, void *bula)
193 {
194 	struct ctl_conn	*c;
195 	struct imsg	 imsg;
196 	int		 n;
197 	unsigned int	 ifidx;
198 	int		 verbose;
199 
200 	if ((c = control_connbyfd(fd)) == NULL) {
201 		log_warn("control_dispatch_imsg: fd %d: not found", fd);
202 		return;
203 	}
204 
205 	if (event & EV_READ) {
206 		if ((n = imsg_read(&c->iev.ibuf)) == -1 || n == 0) {
207 			control_close(fd);
208 			return;
209 		}
210 	}
211 	if (event & EV_WRITE) {
212 		if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) {
213 			control_close(fd);
214 			return;
215 		}
216 	}
217 
218 	for (;;) {
219 		if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) {
220 			control_close(fd);
221 			return;
222 		}
223 
224 		if (n == 0)
225 			break;
226 
227 		switch (imsg.hdr.type) {
228 		case IMSG_CTL_FIB_COUPLE:
229 		case IMSG_CTL_FIB_DECOUPLE:
230 		case IMSG_CTL_RELOAD:
231 			c->iev.ibuf.pid = imsg.hdr.pid;
232 			ldpe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0);
233 			break;
234 		case IMSG_CTL_KROUTE:
235 		case IMSG_CTL_KROUTE_ADDR:
236 		case IMSG_CTL_IFINFO:
237 			c->iev.ibuf.pid = imsg.hdr.pid;
238 			ldpe_imsg_compose_parent(imsg.hdr.type,
239 			    imsg.hdr.pid, imsg.data,
240 			    imsg.hdr.len - IMSG_HEADER_SIZE);
241 			break;
242 		case IMSG_CTL_SHOW_INTERFACE:
243 			if (imsg.hdr.len == IMSG_HEADER_SIZE +
244 			    sizeof(ifidx)) {
245 				memcpy(&ifidx, imsg.data, sizeof(ifidx));
246 				ldpe_iface_ctl(c, ifidx);
247 				imsg_compose_event(&c->iev, IMSG_CTL_END, 0,
248 				    0, -1, NULL, 0);
249 			}
250 			break;
251 		case IMSG_CTL_SHOW_DISCOVERY:
252 			ldpe_adj_ctl(c);
253 			break;
254 		case IMSG_CTL_SHOW_LIB:
255 			c->iev.ibuf.pid = imsg.hdr.pid;
256 			ldpe_imsg_compose_lde(imsg.hdr.type, 0, imsg.hdr.pid,
257 			    imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
258 			break;
259 		case IMSG_CTL_SHOW_NBR:
260 			ldpe_nbr_ctl(c);
261 			break;
262 		case IMSG_CTL_LOG_VERBOSE:
263 			if (imsg.hdr.len != IMSG_HEADER_SIZE +
264 			    sizeof(verbose))
265 				break;
266 
267 			/* forward to other processes */
268 			ldpe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid,
269 			    imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
270 			ldpe_imsg_compose_lde(imsg.hdr.type, 0, imsg.hdr.pid,
271 			    imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
272 
273 			memcpy(&verbose, imsg.data, sizeof(verbose));
274 			log_verbose(verbose);
275 			break;
276 		default:
277 			log_debug("control_dispatch_imsg: "
278 			    "error handling imsg %d", imsg.hdr.type);
279 			break;
280 		}
281 		imsg_free(&imsg);
282 	}
283 
284 	imsg_event_add(&c->iev);
285 }
286 
287 int
288 control_imsg_relay(struct imsg *imsg)
289 {
290 	struct ctl_conn	*c;
291 
292 	if ((c = control_connbypid(imsg->hdr.pid)) == NULL)
293 		return (0);
294 
295 	return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid,
296 	    -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE));
297 }
298 
299 void
300 session_socket_blockmode(int fd, enum blockmodes bm)
301 {
302 	int	flags;
303 
304 	if ((flags = fcntl(fd, F_GETFL, 0)) == -1)
305 		fatal("fcntl F_GETFL");
306 
307 	if (bm == BM_NONBLOCK)
308 		flags |= O_NONBLOCK;
309 	else
310 		flags &= ~O_NONBLOCK;
311 
312 	if ((flags = fcntl(fd, F_SETFL, flags)) == -1)
313 		fatal("fcntl F_SETFL");
314 }
315