xref: /netbsd-src/libexec/mail.local/mail.local.c (revision b49cc1491953ef2348eff9c84520ffd0678a5c8d)
1 /*	$NetBSD: mail.local.c,v 1.25 2008/07/20 01:09:07 lukem Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990, 1993, 1994
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 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1990, 1993, 1994\
35  The Regents of the University of California.  All rights reserved.");
36 #if 0
37 static char sccsid[] = "@(#)mail.local.c	8.22 (Berkeley) 6/21/95";
38 #else
39 __RCSID("$NetBSD: mail.local.c,v 1.25 2008/07/20 01:09:07 lukem Exp $");
40 #endif
41 #endif /* not lint */
42 
43 #include <sys/param.h>
44 #include <sys/stat.h>
45 #include <sys/socket.h>
46 
47 #include <netinet/in.h>
48 
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <pwd.h>
52 #include <netdb.h>
53 #include <stdarg.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <syslog.h>
58 #include <time.h>
59 #include <unistd.h>
60 #include <sysexits.h>
61 
62 
63 #include "pathnames.h"
64 
65 int	deliver __P((int, char *, int));
66 void	logerr __P((int, const char *, ...))
67      __attribute__((__format__(__printf__, 2, 3)));
68 void	logwarn __P((const char *, ...))
69      __attribute__((__format__(__printf__, 1, 2)));
70 void	notifybiff __P((char *));
71 int	store __P((const char *));
72 void	usage __P((void));
73 int	main __P((int, char **));
74 
75 int
76 main(argc, argv)
77 	int argc;
78 	char **argv;
79 {
80 	struct passwd *pw;
81 	int ch, fd, eval, lockfile = 0;
82 	uid_t uid;
83 	const char *from;
84 
85 	/* use a reasonable umask */
86 	(void) umask(0077);
87 
88 	openlog("mail.local", LOG_PERROR, LOG_MAIL);
89 
90 	from = NULL;
91 	while ((ch = getopt(argc, argv, "ldf:r:")) != -1)
92 		switch (ch) {
93 		case 'd':		/* backward compatible */
94 			break;
95 		case 'f':
96 		case 'r':		/* backward compatible */
97 			if (from)
98 				logerr(EX_USAGE, "multiple -f options");
99 			from = optarg;
100 			break;
101 		case 'l':
102 			lockfile++;
103 			break;
104 		case '?':
105 		default:
106 			usage();
107 		}
108 	argc -= optind;
109 	argv += optind;
110 
111 	if (!*argv)
112 		usage();
113 
114 	/*
115 	 * If from not specified, use the name from getlogin() if the
116 	 * uid matches, otherwise, use the name from the password file
117 	 * corresponding to the uid.
118 	 */
119 	uid = getuid();
120 	if (!from && (!(from = getlogin()) ||
121 	    !(pw = getpwnam(from)) || pw->pw_uid != uid))
122 		from = (pw = getpwuid(uid)) ? pw->pw_name : "???";
123 
124 	fd = store(from);
125 	for (eval = EX_OK; *argv; ++argv) {
126 		int rval;
127 
128 		rval = deliver(fd, *argv, lockfile);
129 		if (eval == EX_OK && rval != EX_OK)
130 			eval = rval;
131 	}
132 	exit (eval);
133 }
134 
135 int
136 store(from)
137 	const char *from;
138 {
139 	FILE *fp = NULL;	/* XXX gcc */
140 	time_t tval;
141 	int fd, eline;
142 	char *tn, line[2048];
143 
144 	tn = strdup(_PATH_LOCTMP);
145 	if (!tn)
146 		logerr(EX_OSERR, "not enough core");
147 	if ((fd = mkstemp(tn)) == -1 || !(fp = fdopen(fd, "w+")))
148 		logerr(EX_OSERR, "unable to open temporary file");
149 	(void)unlink(tn);
150 	free(tn);
151 
152 	(void)time(&tval);
153 	(void)fprintf(fp, "From %s %s", from, ctime(&tval));
154 
155 	line[0] = '\0';
156 	for (eline = 1; fgets(line, sizeof(line), stdin);) {
157 		if (line[0] == '\n')
158 			eline = 1;
159 		else {
160 			if (eline && line[0] == 'F' && !memcmp(line, "From ", 5))
161 				(void)putc('>', fp);
162 			eline = 0;
163 		}
164 		(void)fprintf(fp, "%s", line);
165 		if (ferror(fp))
166 			break;
167 	}
168 
169 	/* If message not newline terminated, need an extra. */
170 	if (!index(line, '\n'))
171 		(void)putc('\n', fp);
172 	/* Output a newline; note, empty messages are allowed. */
173 	(void)putc('\n', fp);
174 
175 	(void)fflush(fp);
176 	if (ferror(fp))
177 		logerr(EX_OSERR, "temporary file write error");
178 	fd = dup(fd);
179 	(void)fclose(fp);
180 	return(fd);
181 }
182 
183 int
184 deliver(fd, name, lockfile)
185 	int fd;
186 	char *name;
187 	int lockfile;
188 {
189 	struct stat sb;
190 	struct passwd pwres, *pw;
191 	char pwbuf[1024];
192 	int created, mbfd, nr, nw, off, rval=EX_OK, lfd=-1;
193 	char biffmsg[100], buf[8*1024], path[MAXPATHLEN], lpath[MAXPATHLEN];
194 	off_t curoff;
195 
196 	/*
197 	 * Disallow delivery to unknown names -- special mailboxes can be
198 	 * handled in the sendmail aliases file.
199 	 */
200 	if ((getpwnam_r(name, &pwres, pwbuf, sizeof(pwbuf), &pw)) != 0) {
201 		logwarn("unable to find user %s: %s", name, strerror(errno));
202 		return(EX_TEMPFAIL);
203 	}
204 	if (pw == NULL) {
205 		logwarn("unknown name: %s", name);
206 		return(EX_NOUSER);
207 	}
208 
209 	(void)snprintf(path, sizeof path, "%s/%s", _PATH_MAILDIR, name);
210 
211 	if (lockfile) {
212 		(void)snprintf(lpath, sizeof lpath, "%s/%s.lock",
213 		    _PATH_MAILDIR, name);
214 
215 		if((lfd = open(lpath, O_CREAT|O_WRONLY|O_EXCL,
216 		    S_IRUSR|S_IWUSR)) < 0) {
217 			logwarn("%s: %s", lpath, strerror(errno));
218 			return(EX_OSERR);
219 		}
220 	}
221 
222 	if (!(created = lstat(path, &sb)) &&
223 	    (sb.st_nlink != 1 || S_ISLNK(sb.st_mode))) {
224 		logwarn("%s: linked file", path);
225 		return(EX_OSERR);
226 	}
227 
228 	if ((mbfd = open(path, O_APPEND|O_WRONLY|O_EXLOCK,
229 	    S_IRUSR|S_IWUSR)) < 0) {
230 		if ((mbfd = open(path, O_APPEND|O_CREAT|O_WRONLY|O_EXLOCK,
231 		    S_IRUSR|S_IWUSR)) < 0) {
232 			logwarn("%s: %s", path, strerror(errno));
233 			return(EX_OSERR);
234 		}
235 	}
236 
237 	curoff = lseek(mbfd, 0, SEEK_END);
238 	(void)snprintf(biffmsg, sizeof biffmsg, "%s@%lld\n", name,
239 	    (long long)curoff);
240 	if (lseek(fd, 0, SEEK_SET) == (off_t)-1) {
241 		logwarn("temporary file: %s", strerror(errno));
242 		rval = EX_OSERR;
243 		goto bad;
244 	}
245 
246 	while ((nr = read(fd, buf, sizeof(buf))) > 0)
247 		for (off = 0; off < nr;  off += nw)
248 			if ((nw = write(mbfd, buf + off, nr - off)) < 0) {
249 				logwarn("%s: %s", path, strerror(errno));
250 				goto trunc;
251 			}
252 	if (nr < 0) {
253 		logwarn("temporary file: %s", strerror(errno));
254 trunc:		(void)ftruncate(mbfd, curoff);
255 		rval = EX_OSERR;
256 	}
257 
258 	/*
259 	 * Set the owner and group.  Historically, binmail repeated this at
260 	 * each mail delivery.  We no longer do this, assuming that if the
261 	 * ownership or permissions were changed there was a reason for doing
262 	 * so.
263 	 */
264 bad:
265 	if (lockfile) {
266 		if (lfd >= 0) {
267 			unlink(lpath);
268 			close(lfd);
269 		}
270 	}
271 	if (created)
272 		(void)fchown(mbfd, pw->pw_uid, pw->pw_gid);
273 
274 	(void)fsync(mbfd);		/* Don't wait for update. */
275 	(void)close(mbfd);		/* Implicit unlock. */
276 
277 	if (rval == EX_OK)
278 		notifybiff(biffmsg);
279 
280 	return rval;
281 }
282 
283 void
284 notifybiff(msg)
285 	char *msg;
286 {
287 	static struct sockaddr_in addr;
288 	static int f = -1;
289 	struct hostent *hp;
290 	struct servent *sp;
291 	int len;
292 
293 	if (!addr.sin_family) {
294 		/* Be silent if biff service not available. */
295 		if (!(sp = getservbyname("biff", "udp")))
296 			return;
297 		if (!(hp = gethostbyname("localhost"))) {
298 			logwarn("localhost: %s", strerror(errno));
299 			return;
300 		}
301 		addr.sin_len = sizeof(struct sockaddr_in);
302 		addr.sin_family = hp->h_addrtype;
303 		addr.sin_port = sp->s_port;
304 		memcpy(&addr.sin_addr, hp->h_addr, hp->h_length);
305 	}
306 	if (f < 0 && (f = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
307 		logwarn("socket: %s", strerror(errno));
308 		return;
309 	}
310 	len = strlen(msg) + 1;
311 	if (sendto(f, msg, len, 0, (struct sockaddr *)&addr, sizeof(addr))
312 	    != len)
313 		logwarn("sendto biff: %s", strerror(errno));
314 }
315 
316 void
317 usage()
318 {
319 	logerr(EX_USAGE, "usage: mail.local [-l] [-f from] user ...");
320 }
321 
322 void
323 logerr(int status, const char *fmt, ...)
324 {
325 	va_list ap;
326 
327 	va_start(ap, fmt);
328 	vsyslog(LOG_ERR, fmt, ap);
329 	va_end(ap);
330 
331 	exit(status);
332 	/* NOTREACHED */
333 	return;
334 }
335 
336 void
337 logwarn(const char *fmt, ...)
338 {
339 	va_list ap;
340 
341 	va_start(ap, fmt);
342 	vsyslog(LOG_ERR, fmt, ap);
343 	va_end(ap);
344 	return;
345 }
346