xref: /freebsd/usr.bin/logger/logger.c (revision 43a5ec4eb41567cc92586503212743d89686d78f)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  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  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 static const char copyright[] =
34 "@(#) Copyright (c) 1983, 1993\n\
35 	The Regents of the University of California.  All rights reserved.\n";
36 #endif /* not lint */
37 
38 #if 0
39 #ifndef lint
40 static char sccsid[] = "@(#)logger.c	8.1 (Berkeley) 6/6/93";
41 #endif /* not lint */
42 #endif
43 
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46 
47 #include <sys/capsicum.h>
48 #include <sys/param.h>
49 #include <sys/socket.h>
50 #include <netinet/in.h>
51 
52 #include <capsicum_helpers.h>
53 #include <ctype.h>
54 #include <err.h>
55 #include <netdb.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <time.h>
60 #include <unistd.h>
61 
62 #include <libcasper.h>
63 #include <casper/cap_syslog.h>
64 
65 #define	SYSLOG_NAMES
66 #include <syslog.h>
67 
68 #define	sstosa(ss)	((struct sockaddr *)(void *)ss)
69 
70 struct socks {
71 	int sk_sock;
72 	int sk_addrlen;
73 	struct sockaddr_storage sk_addr;
74 };
75 
76 static int	decode(char *, const CODE *);
77 static int	pencode(char *);
78 static ssize_t	socksetup(const char *, const char *, const char *,
79 		    struct socks **);
80 static void	logmessage(int, const char *, const char *, const char *,
81 		    struct socks *, ssize_t, const char *);
82 static void	usage(void);
83 
84 static cap_channel_t *capsyslog;
85 #ifdef INET6
86 static int family = PF_UNSPEC;	/* protocol family (IPv4, IPv6 or both) */
87 #else
88 static int family = PF_INET;	/* protocol family (IPv4 only) */
89 #endif
90 static int send_to_all = 0;	/* send message to all IPv4/IPv6 addresses */
91 
92 /*
93  * logger -- read and log utility
94  *
95  *	Reads from an input and arranges to write the result on the system
96  *	log.
97  */
98 int
99 main(int argc, char *argv[])
100 {
101 	cap_channel_t *capcas;
102 	struct socks *socks;
103 	ssize_t nsock;
104 	time_t now;
105 	int ch, logflags, pri;
106 	char *tag, *host, buf[1024], *timestamp, tbuf[26],
107 	    *hostname, hbuf[MAXHOSTNAMELEN], *pristr;
108 	const char *svcname, *src;
109 
110 	tag = NULL;
111 	host = NULL;
112 	hostname = NULL;
113 	svcname = "syslog";
114 	src = NULL;
115 	socks = NULL;
116 	pri = LOG_USER | LOG_NOTICE;
117 	pristr = NULL;
118 	logflags = 0;
119 	unsetenv("TZ");
120 	while ((ch = getopt(argc, argv, "46Af:H:h:iP:p:S:st:")) != -1)
121 		switch((char)ch) {
122 		case '4':
123 			family = PF_INET;
124 			break;
125 #ifdef INET6
126 		case '6':
127 			family = PF_INET6;
128 			break;
129 #endif
130 		case 'A':
131 			send_to_all++;
132 			break;
133 		case 'f':		/* file to log */
134 			if (freopen(optarg, "r", stdin) == NULL)
135 				err(1, "%s", optarg);
136 			setvbuf(stdin, 0, _IONBF, 0);
137 			break;
138 		case 'H':		/* hostname to set in message header */
139 			hostname = optarg;
140 			break;
141 		case 'h':		/* hostname to deliver to */
142 			host = optarg;
143 			break;
144 		case 'i':		/* log process id also */
145 			logflags |= LOG_PID;
146 			break;
147 		case 'P':		/* service name or port number */
148 			svcname = optarg;
149 			break;
150 		case 'p':		/* priority */
151 			pristr = optarg;
152 			break;
153 		case 's':		/* log to standard error */
154 			logflags |= LOG_PERROR;
155 			break;
156 		case 'S':		/* source address */
157 			src = optarg;
158 			break;
159 		case 't':		/* tag */
160 			tag = optarg;
161 			break;
162 		case '?':
163 		default:
164 			usage();
165 		}
166 	argc -= optind;
167 	argv += optind;
168 
169 	if (host) {
170 		nsock = socksetup(src, host, svcname, &socks);
171 		if (nsock <= 0)
172 			errx(1, "socket");
173 	} else {
174 		if (src)
175 			errx(1, "-h option is missing.");
176 		nsock = 0;
177 	}
178 
179 	capcas = cap_init();
180 	if (capcas == NULL)
181 		err(1, "Unable to contact Casper");
182 	caph_cache_catpages();
183 	caph_cache_tzdata();
184 	if (nsock == 0) {
185 		if (caph_enter() < 0)
186 			err(1, "Unable to enter capability mode");
187 	}
188 	capsyslog = cap_service_open(capcas, "system.syslog");
189 	if (capsyslog == NULL)
190 		err(1, "Unable to open system.syslog service");
191 	cap_close(capcas);
192 
193 	if (pristr != NULL)
194 		pri = pencode(pristr);
195 	if (tag == NULL)
196 		tag = getlogin();
197 	/* setup for logging */
198 	if (host == NULL)
199 		cap_openlog(capsyslog, tag, logflags, 0);
200 
201 	(void )time(&now);
202 	(void )ctime_r(&now, tbuf);
203 	tbuf[19] = '\0';
204 	timestamp = tbuf + 4;
205 
206 	if (hostname == NULL) {
207 		hostname = hbuf;
208 		(void )gethostname(hbuf, MAXHOSTNAMELEN);
209 		*strchrnul(hostname, '.') = '\0';
210 	}
211 
212 	/* log input line if appropriate */
213 	if (argc > 0) {
214 		char *p, *endp;
215 		size_t len;
216 
217 		for (p = buf, endp = buf + sizeof(buf) - 2; *argv;) {
218 			len = strlen(*argv);
219 			if (p + len > endp && p > buf) {
220 				logmessage(pri, timestamp, hostname, tag,
221 				    socks, nsock, buf);
222 				p = buf;
223 			}
224 			if (len > sizeof(buf) - 1)
225 				logmessage(pri, timestamp, hostname, tag,
226 				    socks, nsock, *argv++);
227 			else {
228 				if (p != buf)
229 					*p++ = ' ';
230 				bcopy(*argv++, p, len);
231 				*(p += len) = '\0';
232 			}
233 		}
234 		if (p != buf)
235 			logmessage(pri, timestamp, hostname, tag, socks, nsock,
236 			    buf);
237 	} else
238 		while (fgets(buf, sizeof(buf), stdin) != NULL)
239 			logmessage(pri, timestamp, hostname, tag, socks, nsock,
240 			    buf);
241 	exit(0);
242 }
243 
244 static ssize_t
245 socksetup(const char *src, const char *dst, const char *svcname,
246 	struct socks **socks)
247 {
248 	struct addrinfo hints, *res, *res0;
249 	struct sockaddr_storage *ss_src[AF_MAX];
250 	struct socks *sk;
251 	ssize_t nsock = 0;
252 	int error, maxs;
253 
254 	memset(&ss_src[0], 0, sizeof(ss_src));
255 	if (src) {
256 		char *p, *p0, *hs, *hbuf, *sbuf;
257 
258 		hbuf = sbuf = NULL;
259 		p0 = p = strdup(src);
260 		if (p0 == NULL)
261 			err(1, "strdup failed");
262 		hs = p0;	/* point to search ":" */
263 #ifdef INET6
264 		/* -S option supports IPv6 addr in "[2001:db8::1]:service". */
265 		if (*p0 == '[') {
266 			p = strchr(p0, ']');
267 			if (p == NULL)
268 				errx(1, "\"]\" not found in src addr");
269 			*p = '\0';
270 			/* hs points just after ']' (':' or '\0'). */
271 			hs = p + 1;
272 			/*
273 			 * p points just after '[' while it points hs
274 			 * in the case of [].
275 			 */
276 			p = ((p0 + 1) == (hs - 1)) ? hs : p0 + 1;
277 		}
278 #endif
279 		if (*p != '\0') {
280 			/* (p == hs) means ":514" or "[]:514". */
281 			hbuf = (p == hs && *p == ':') ? NULL : p;
282 			p = strchr(hs, ':');
283 			if (p != NULL) {
284 				*p = '\0';
285 				sbuf = (*(p + 1) != '\0') ? p + 1 : NULL;
286 			}
287 		}
288 		hints = (struct addrinfo){
289 			.ai_family = family,
290 			.ai_socktype = SOCK_DGRAM,
291 			.ai_flags = AI_PASSIVE
292 		};
293 		error = getaddrinfo(hbuf, sbuf, &hints, &res0);
294 		if (error)
295 			errx(1, "%s: %s", gai_strerror(error), src);
296 		for (res = res0; res; res = res->ai_next) {
297 			switch (res->ai_family) {
298 			case AF_INET:
299 #ifdef INET6
300 			case AF_INET6:
301 #endif
302 				if (ss_src[res->ai_family] != NULL)
303 					continue;
304 				ss_src[res->ai_family] =
305 				    malloc(sizeof(struct sockaddr_storage));
306 				if (ss_src[res->ai_family] == NULL)
307 					err(1, "malloc failed");
308 				memcpy(ss_src[res->ai_family], res->ai_addr,
309 				    res->ai_addrlen);
310 			}
311 		}
312 		freeaddrinfo(res0);
313 		free(p0);
314 	}
315 
316 	/* resolve hostname */
317 	hints = (struct addrinfo){
318 		.ai_family = family,
319 		.ai_socktype = SOCK_DGRAM
320 	};
321 	error = getaddrinfo(dst, svcname, &hints, &res0);
322 	if (error == EAI_SERVICE) {
323 		warnx("%s/udp: unknown service", svcname);
324 		error = getaddrinfo(dst, "514", &hints, &res0);
325 	}
326 	if (error)
327 		errx(1, "%s: %s", gai_strerror(error), dst);
328 	/* count max number of sockets we may open */
329 	maxs = 0;
330 	for (res = res0; res; res = res->ai_next)
331 		maxs++;
332 	sk = calloc(maxs, sizeof(*sk));
333 	if (sk == NULL)
334 		errx(1, "couldn't allocate memory for sockets");
335 	for (res = res0; res; res = res->ai_next) {
336 		int s;
337 
338 		s = socket(res->ai_family, res->ai_socktype,
339 		    res->ai_protocol);
340 		if (s < 0)
341 			continue;
342 		if (src && ss_src[res->ai_family] == NULL)
343 			errx(1, "address family mismatch");
344 
345 		if (ss_src[res->ai_family]) {
346 			error = bind(s, sstosa(ss_src[res->ai_family]),
347 				    ss_src[res->ai_family]->ss_len);
348 			if (error < 0)
349 				err(1, "bind");
350 		}
351 		sk[nsock] = (struct socks){
352 			.sk_addrlen = res->ai_addrlen,
353 			.sk_sock = s
354 		};
355 		memcpy(&sk[nsock].sk_addr, res->ai_addr, res->ai_addrlen);
356 		nsock++;
357 	}
358 	freeaddrinfo(res0);
359 
360 	*socks = sk;
361 	return (nsock);
362 }
363 
364 /*
365  *  Send the message to syslog, either on the local host, or on a remote host
366  */
367 static void
368 logmessage(int pri, const char *timestamp, const char *hostname,
369     const char *tag, struct socks *sk, ssize_t nsock, const char *buf)
370 {
371 	char *line;
372 	int len, i, lsent;
373 
374 	if (nsock == 0) {
375 		cap_syslog(capsyslog, pri, "%s", buf);
376 		return;
377 	}
378 	if ((len = asprintf(&line, "<%d>%s %s %s: %s", pri, timestamp,
379 	    hostname, tag, buf)) == -1)
380 		errx(1, "asprintf");
381 
382 	lsent = -1;
383 	for (i = 0; i < nsock; i++) {
384 		lsent = sendto(sk[i].sk_sock, line, len, 0,
385 			       sstosa(&sk[i].sk_addr), sk[i].sk_addrlen);
386 		if (lsent == len && !send_to_all)
387 			break;
388 	}
389 	if (lsent != len) {
390 		if (lsent == -1)
391 			warn("sendto");
392 		else
393 			warnx("sendto: short send - %d bytes", lsent);
394 	}
395 
396 	free(line);
397 }
398 
399 /*
400  *  Decode a symbolic name to a numeric value
401  */
402 static int
403 pencode(char *s)
404 {
405 	char *save;
406 	int fac, lev;
407 
408 	for (save = s; *s && *s != '.'; ++s);
409 	if (*s) {
410 		*s = '\0';
411 		fac = decode(save, facilitynames);
412 		if (fac < 0)
413 			errx(1, "unknown facility name: %s", save);
414 		*s++ = '.';
415 	}
416 	else {
417 		fac = 0;
418 		s = save;
419 	}
420 	lev = decode(s, prioritynames);
421 	if (lev < 0)
422 		errx(1, "unknown priority name: %s", save);
423 	return ((lev & LOG_PRIMASK) | (fac & LOG_FACMASK));
424 }
425 
426 static int
427 decode(char *name, const CODE *codetab)
428 {
429 	const CODE *c;
430 
431 	if (isdigit(*name))
432 		return (atoi(name));
433 
434 	for (c = codetab; c->c_name; c++)
435 		if (!strcasecmp(name, c->c_name))
436 			return (c->c_val);
437 
438 	return (-1);
439 }
440 
441 static void
442 usage(void)
443 {
444 	(void)fprintf(stderr, "usage: %s\n",
445 	    "logger [-46Ais] [-f file] [-h host] [-P port] [-p pri] [-t tag]\n"
446 	    "              [-S addr:port] [message ...]"
447 	    );
448 	exit(1);
449 }
450