xref: /freebsd/usr.sbin/rtadvd/control.c (revision cd0d51baaa4509a1db83251a601d34404d20c990)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (C) 2011 Hiroki Sato <hrs@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
23  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
25  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
26  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  *
30  */
31 
32 #include <sys/queue.h>
33 #include <sys/types.h>
34 #include <sys/socket.h>
35 #include <sys/stat.h>
36 #include <sys/un.h>
37 #include <sys/uio.h>
38 #include <net/if.h>
39 #include <net/if_dl.h>
40 #include <netinet/in.h>
41 #include <netinet/icmp6.h>
42 #include <fcntl.h>
43 #include <errno.h>
44 #include <netdb.h>
45 #include <unistd.h>
46 #include <poll.h>
47 #include <signal.h>
48 #include <string.h>
49 #include <stdarg.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <syslog.h>
53 
54 #include "rtadvd.h"
55 #include "if.h"
56 #include "pathnames.h"
57 #include "control.h"
58 
59 #define	CM_RECV_TIMEOUT	30
60 
61 int
62 cm_recv(int fd, char *buf)
63 {
64 	ssize_t n;
65 	struct ctrl_msg_hdr	*cm;
66 	char *msg;
67 	struct pollfd pfds[1];
68 	int i;
69 
70 	syslog(LOG_DEBUG, "<%s> enter, fd=%d", __func__, fd);
71 
72 	memset(buf, 0, CM_MSG_MAXLEN);
73 	cm = (struct ctrl_msg_hdr *)buf;
74 	msg = (char *)buf + sizeof(*cm);
75 
76 	pfds[0].fd = fd;
77 	pfds[0].events = POLLIN;
78 
79 	for (;;) {
80 		i = poll(pfds, sizeof(pfds)/sizeof(pfds[0]),
81 		    CM_RECV_TIMEOUT);
82 
83 		if (i == 0)
84 			continue;
85 
86 		if (i < 0) {
87 			syslog(LOG_ERR, "<%s> poll error: %s",
88 			    __func__, strerror(errno));
89 			continue;
90 		}
91 
92 		if (pfds[0].revents & POLLIN) {
93 			n = read(fd, cm, sizeof(*cm));
94 			if (n < 0 && errno == EAGAIN) {
95 				syslog(LOG_DEBUG,
96 				    "<%s> waiting...", __func__);
97 				continue;
98 			}
99 			break;
100 		}
101 	}
102 
103 	if (n != (ssize_t)sizeof(*cm)) {
104 		syslog(LOG_WARNING,
105 		    "<%s> received a too small message.", __func__);
106 		goto cm_recv_err;
107 	}
108 	if (cm->cm_len > CM_MSG_MAXLEN) {
109 		syslog(LOG_WARNING,
110 		    "<%s> received a too large message.", __func__);
111 		goto cm_recv_err;
112 	}
113 	if (cm->cm_version != CM_VERSION) {
114 		syslog(LOG_WARNING,
115 		    "<%s> version mismatch", __func__);
116 		goto cm_recv_err;
117 	}
118 	if (cm->cm_type >= CM_TYPE_MAX) {
119 		syslog(LOG_WARNING,
120 		    "<%s> invalid msg type.", __func__);
121 		goto cm_recv_err;
122 	}
123 
124 	syslog(LOG_DEBUG,
125 	    "<%s> ctrl msg received: type=%d", __func__,
126 	    cm->cm_type);
127 
128 	if (cm->cm_len > sizeof(*cm)) {
129 		size_t msglen = cm->cm_len - sizeof(*cm);
130 
131 		syslog(LOG_DEBUG,
132 		    "<%s> ctrl msg has payload (len=%zu)", __func__,
133 		    msglen);
134 
135 		for (;;) {
136 			i = poll(pfds, sizeof(pfds)/sizeof(pfds[0]),
137 			    CM_RECV_TIMEOUT);
138 
139 			if (i == 0)
140 				continue;
141 
142 			if (i < 0) {
143 				syslog(LOG_ERR, "<%s> poll error: %s",
144 				    __func__, strerror(errno));
145 				continue;
146 			}
147 
148 			if (pfds[0].revents & POLLIN) {
149 				n = read(fd, msg, msglen);
150 				if (n < 0 && errno == EAGAIN) {
151 					syslog(LOG_DEBUG,
152 					    "<%s> waiting...", __func__);
153 					continue;
154 				}
155 			}
156 			break;
157 		}
158 		if (n != (ssize_t)msglen) {
159 			syslog(LOG_WARNING,
160 			    "<%s> payload size mismatch.", __func__);
161 			goto cm_recv_err;
162 		}
163 		buf[CM_MSG_MAXLEN - 1] = '\0';
164 	}
165 
166 	return (0);
167 
168 cm_recv_err:
169 	close(fd);
170 	return (-1);
171 }
172 
173 int
174 cm_send(int fd, char *buf)
175 {
176 	struct iovec iov[2];
177 	int iovcnt;
178 	ssize_t len;
179 	ssize_t iov_len_total;
180 	struct ctrl_msg_hdr *cm;
181 	char *msg;
182 
183 	cm = (struct ctrl_msg_hdr *)buf;
184 	msg = (char *)buf + sizeof(*cm);
185 
186 	iovcnt = 1;
187 	iov[0].iov_base = cm;
188 	iov[0].iov_len = sizeof(*cm);
189 	iov_len_total = iov[0].iov_len;
190 	if (cm->cm_len > sizeof(*cm)) {
191 		iovcnt++;
192 		iov[1].iov_base = msg;
193 		iov[1].iov_len = cm->cm_len - iov[0].iov_len;
194 		iov_len_total += iov[1].iov_len;
195 	}
196 
197 	syslog(LOG_DEBUG,
198 	    "<%s> ctrl msg send: type=%d, count=%d, total_len=%zd", __func__,
199 	    cm->cm_type, iovcnt, iov_len_total);
200 
201 	len = writev(fd, iov, iovcnt);
202 	syslog(LOG_DEBUG,
203 	    "<%s> ctrl msg send: length=%zd", __func__, len);
204 
205 	if (len == -1) {
206 		syslog(LOG_DEBUG,
207 		    "<%s> write failed: (%d)%s", __func__, errno,
208 		    strerror(errno));
209 		close(fd);
210 		return (-1);
211 	}
212 
213 	syslog(LOG_DEBUG,
214 	    "<%s> write length = %zd (actual)", __func__, len);
215 	syslog(LOG_DEBUG,
216 	    "<%s> write length = %zd (expected)", __func__, iov_len_total);
217 
218 	if (len != iov_len_total) {
219 		close(fd);
220 		return (-1);
221 	}
222 
223 	return (0);
224 }
225 
226 int
227 csock_accept(struct sockinfo *s)
228 {
229 	struct sockaddr_un	sun;
230 	int	flags;
231 	int	fd;
232 
233 	sun.sun_len = sizeof(sun);
234 	if ((fd = accept(s->si_fd, (struct sockaddr *)&sun,
235 		    (socklen_t *)&sun.sun_len)) == -1) {
236 		if (errno != EWOULDBLOCK && errno != EINTR)
237 			syslog(LOG_WARNING, "<%s> accept ", __func__);
238 		syslog(LOG_WARNING, "<%s> Xaccept: %s", __func__, strerror(errno));
239 		return (-1);
240 	}
241 	if ((flags = fcntl(fd, F_GETFL, 0)) == -1) {
242 		syslog(LOG_WARNING, "<%s> fcntl F_GETFL", __func__);
243 		close(s->si_fd);
244 		return (-1);
245 	}
246 	if ((flags = fcntl(fd, F_SETFL, flags | O_NONBLOCK)) == -1) {
247 		syslog(LOG_WARNING, "<%s> fcntl F_SETFL", __func__);
248 		return (-1);
249 	}
250 	syslog(LOG_DEBUG, "<%s> accept connfd=%d, listenfd=%d", __func__,
251 	    fd, s->si_fd);
252 
253 	return (fd);
254 }
255 
256 int
257 csock_close(struct sockinfo *s)
258 {
259 	close(s->si_fd);
260 	unlink(s->si_name);
261 	syslog(LOG_DEBUG, "<%s> remove %s", __func__, s->si_name);
262 	return (0);
263 }
264 
265 int
266 csock_listen(struct sockinfo *s)
267 {
268 	if (s->si_fd == -1) {
269 		syslog(LOG_ERR, "<%s> listen failed", __func__);
270 		return (-1);
271 	}
272 	if (listen(s->si_fd, SOCK_BACKLOG) == -1) {
273 		syslog(LOG_ERR, "<%s> listen failed", __func__);
274 		return (-1);
275 	}
276 
277 	return (0);
278 }
279 
280 int
281 csock_open(struct sockinfo *s, mode_t mode)
282 {
283 	int flags;
284 	struct sockaddr_un	sun;
285 	mode_t	old_umask;
286 
287 	if (s == NULL) {
288 		syslog(LOG_ERR, "<%s> internal error.", __func__);
289 		exit(1);
290 	}
291 	if (s->si_name == NULL)
292 		s->si_name = _PATH_CTRL_SOCK;
293 
294 	if ((s->si_fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) {
295 		syslog(LOG_ERR,
296 		    "<%s> cannot open control socket", __func__);
297 		return (-1);
298 	}
299 	memset(&sun, 0, sizeof(sun));
300 	sun.sun_family = AF_UNIX;
301 	sun.sun_len = sizeof(sun);
302 	strlcpy(sun.sun_path, s->si_name, sizeof(sun.sun_path));
303 
304 	if (unlink(s->si_name) == -1)
305 		if (errno != ENOENT) {
306 			syslog(LOG_ERR,
307 			    "<%s> unlink %s", __func__, s->si_name);
308 			close(s->si_fd);
309 			return (-1);
310 		}
311 	old_umask = umask(S_IXUSR|S_IXGRP|S_IXOTH);
312 	if (bind(s->si_fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
313 		syslog(LOG_ERR,
314 		    "<%s> bind failed: %s", __func__, s->si_name);
315 		close(s->si_fd);
316 		umask(old_umask);
317 		return (-1);
318 	}
319 	umask(old_umask);
320 	if (chmod(s->si_name, mode) == -1) {
321 		syslog(LOG_ERR,
322 		    "<%s> chmod failed: %s", __func__, s->si_name);
323 		goto csock_open_err;
324 	}
325 	if ((flags = fcntl(s->si_fd, F_GETFL, 0)) == -1) {
326 		syslog(LOG_ERR,
327 		    "<%s> fcntl F_GETFL failed: %s", __func__, s->si_name);
328 		goto csock_open_err;
329 	}
330 	if ((flags = fcntl(s->si_fd, F_SETFL, flags | O_NONBLOCK)) == -1) {
331 		syslog(LOG_ERR,
332 		    "<%s> fcntl F_SETFL failed: %s", __func__, s->si_name);
333 		goto csock_open_err;
334 	}
335 
336 	return (s->si_fd);
337 
338 csock_open_err:
339 	close(s->si_fd);
340 	unlink(s->si_name);
341 	return (-1);
342 }
343 
344 struct ctrl_msg_pl *
345 cm_bin2pl(char *str, struct ctrl_msg_pl *cp)
346 {
347 	size_t len;
348 	size_t *lenp;
349 	char *p;
350 
351 	memset(cp, 0, sizeof(*cp));
352 
353 	p = str;
354 
355 	lenp = (size_t *)p;
356 	len = *lenp++;
357 	p = (char *)lenp;
358 	syslog(LOG_DEBUG, "<%s> len(ifname) = %zu", __func__, len);
359 	if (len > 0) {
360 		cp->cp_ifname = malloc(len + 1);
361 		if (cp->cp_ifname == NULL) {
362 			syslog(LOG_ERR, "<%s> malloc", __func__);
363 			exit(1);
364 		}
365 		memcpy(cp->cp_ifname, p, len);
366 		cp->cp_ifname[len] = '\0';
367 		p += len;
368 	}
369 
370 	lenp = (size_t *)p;
371 	len = *lenp++;
372 	p = (char *)lenp;
373 	syslog(LOG_DEBUG, "<%s> len(key) = %zu", __func__, len);
374 	if (len > 0) {
375 		cp->cp_key = malloc(len + 1);
376 		if (cp->cp_key == NULL) {
377 			syslog(LOG_ERR, "<%s> malloc", __func__);
378 			exit(1);
379 		}
380 		memcpy(cp->cp_key, p, len);
381 		cp->cp_key[len] = '\0';
382 		p += len;
383 	}
384 
385 	lenp = (size_t *)p;
386 	len = *lenp++;
387 	p = (char *)lenp;
388 	syslog(LOG_DEBUG, "<%s> len(val) = %zu", __func__, len);
389 	if (len > 0) {
390 		cp->cp_val = malloc(len + 1);
391 		if (cp->cp_val == NULL) {
392 			syslog(LOG_ERR, "<%s> malloc", __func__);
393 			exit(1);
394 		}
395 		memcpy(cp->cp_val, p, len);
396 		cp->cp_val[len] = '\0';
397 		cp->cp_val_len = len;
398 	} else
399 		cp->cp_val_len = 0;
400 
401 	return (cp);
402 }
403 
404 size_t
405 cm_pl2bin(char *str, struct ctrl_msg_pl *cp)
406 {
407 	size_t len;
408 	size_t *lenp;
409 	char *p;
410 	struct ctrl_msg_hdr *cm;
411 
412 	len = sizeof(size_t);
413 	if (cp->cp_ifname != NULL)
414 		len += strlen(cp->cp_ifname);
415 	len += sizeof(size_t);
416 	if (cp->cp_key != NULL)
417 		len += strlen(cp->cp_key);
418 	len += sizeof(size_t);
419 	if (cp->cp_val != NULL && cp->cp_val_len > 0)
420 		len += cp->cp_val_len;
421 
422 	if (len > CM_MSG_MAXLEN - sizeof(*cm)) {
423 		syslog(LOG_DEBUG, "<%s> msg too long (len=%zu)",
424 		    __func__, len);
425 		return (0);
426 	}
427 	syslog(LOG_DEBUG, "<%s> msglen=%zu", __func__, len);
428 	memset(str, 0, len);
429 	p = str;
430 	lenp = (size_t *)p;
431 
432 	if (cp->cp_ifname != NULL) {
433 		*lenp++ = strlen(cp->cp_ifname);
434 		p = (char *)lenp;
435 		memcpy(p, cp->cp_ifname, strlen(cp->cp_ifname));
436 		p += strlen(cp->cp_ifname);
437 	} else {
438 		*lenp++ = '\0';
439 		p = (char *)lenp;
440 	}
441 
442 	lenp = (size_t *)p;
443 	if (cp->cp_key != NULL) {
444 		*lenp++ = strlen(cp->cp_key);
445 		p = (char *)lenp;
446 		memcpy(p, cp->cp_key, strlen(cp->cp_key));
447 		p += strlen(cp->cp_key);
448 	} else {
449 		*lenp++ = '\0';
450 		p = (char *)lenp;
451 	}
452 
453 	lenp = (size_t *)p;
454 	if (cp->cp_val != NULL && cp->cp_val_len > 0) {
455 		*lenp++ = cp->cp_val_len;
456 		p = (char *)lenp;
457 		memcpy(p, cp->cp_val, cp->cp_val_len);
458 		p += cp->cp_val_len;
459 	} else {
460 		*lenp++ = '\0';
461 		p = (char *)lenp;
462 	}
463 
464 	return (len);
465 }
466 
467 size_t
468 cm_str2bin(char *bin, void *str, size_t len)
469 {
470 	struct ctrl_msg_hdr *cm;
471 
472 	syslog(LOG_DEBUG, "<%s> enter", __func__);
473 
474 	if (len > CM_MSG_MAXLEN - sizeof(*cm)) {
475 		syslog(LOG_DEBUG, "<%s> msg too long (len=%zu)",
476 		    __func__, len);
477 		return (0);
478 	}
479 	syslog(LOG_DEBUG, "<%s> msglen=%zu", __func__, len);
480 	memcpy(bin, (char *)str, len);
481 
482 	return (len);
483 }
484 
485 void *
486 cm_bin2str(char *bin, void *str, size_t len)
487 {
488 
489 	syslog(LOG_DEBUG, "<%s> enter", __func__);
490 
491 	memcpy((char *)str, bin, len);
492 
493 	return (str);
494 }
495