xref: /netbsd-src/libexec/mail.local/mail.local.c (revision b519c70ad771d0a55b3c2277db6b97a05fa6465d)
1 /*	$NetBSD: mail.local.c,v 1.19 2001/12/20 20:10:35 soren 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT("@(#) Copyright (c) 1990, 1993, 1994\n\
39 	The Regents of the University of California.  All rights reserved.\n");
40 #if 0
41 static char sccsid[] = "@(#)mail.local.c	8.22 (Berkeley) 6/21/95";
42 #else
43 __RCSID("$NetBSD: mail.local.c,v 1.19 2001/12/20 20:10:35 soren Exp $");
44 #endif
45 #endif /* not lint */
46 
47 #include <sys/param.h>
48 #include <sys/stat.h>
49 #include <sys/socket.h>
50 
51 #include <netinet/in.h>
52 
53 #include <errno.h>
54 #include <fcntl.h>
55 #include <pwd.h>
56 #include <netdb.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <syslog.h>
61 #include <time.h>
62 #include <unistd.h>
63 
64 #include "pathnames.h"
65 
66 #define	FATAL		1
67 #define	NOTFATAL	0
68 
69 int	deliver __P((int, char *, int));
70 void	err __P((int, const char *, ...))
71      __attribute__((__format__(__printf__, 2, 3)));
72 void	notifybiff __P((char *));
73 int	store __P((const char *));
74 void	usage __P((void));
75 int	main __P((int, char **));
76 
77 int
78 main(argc, argv)
79 	int argc;
80 	char **argv;
81 {
82 	struct passwd *pw;
83 	int ch, fd, eval, lockfile = 0;
84 	uid_t uid;
85 	const char *from;
86 
87 	/* use a reasonable umask */
88 	(void) umask(0077);
89 
90 	openlog("mail.local", LOG_PERROR, LOG_MAIL);
91 
92 	from = NULL;
93 	while ((ch = getopt(argc, argv, "ldf:r:")) != -1)
94 		switch (ch) {
95 		case 'd':		/* backward compatible */
96 			break;
97 		case 'f':
98 		case 'r':		/* backward compatible */
99 			if (from)
100 				err(FATAL, "multiple -f options");
101 			from = optarg;
102 			break;
103 		case 'l':
104 			lockfile++;
105 			break;
106 		case '?':
107 		default:
108 			usage();
109 		}
110 	argc -= optind;
111 	argv += optind;
112 
113 	if (!*argv)
114 		usage();
115 
116 	/*
117 	 * If from not specified, use the name from getlogin() if the
118 	 * uid matches, otherwise, use the name from the password file
119 	 * corresponding to the uid.
120 	 */
121 	uid = getuid();
122 	if (!from && (!(from = getlogin()) ||
123 	    !(pw = getpwnam(from)) || pw->pw_uid != uid))
124 		from = (pw = getpwuid(uid)) ? pw->pw_name : "???";
125 
126 	fd = store(from);
127 	for (eval = 0; *argv; ++argv)
128 		eval |= deliver(fd, *argv, lockfile);
129 	exit (eval);
130 }
131 
132 int
133 store(from)
134 	const char *from;
135 {
136 	FILE *fp = NULL;	/* XXX gcc */
137 	time_t tval;
138 	int fd, eline;
139 	char *tn, line[2048];
140 
141 	tn = strdup(_PATH_LOCTMP);
142 	if ((fd = mkstemp(tn)) == -1 || !(fp = fdopen(fd, "w+")))
143 		err(FATAL, "unable to open temporary file");
144 	(void)unlink(tn);
145 	free(tn);
146 
147 	(void)time(&tval);
148 	(void)fprintf(fp, "From %s %s", from, ctime(&tval));
149 
150 	line[0] = '\0';
151 	for (eline = 1; fgets(line, sizeof(line), stdin);) {
152 		if (line[0] == '\n')
153 			eline = 1;
154 		else {
155 			if (eline && line[0] == 'F' && !memcmp(line, "From ", 5))
156 				(void)putc('>', fp);
157 			eline = 0;
158 		}
159 		(void)fprintf(fp, "%s", line);
160 		if (ferror(fp))
161 			break;
162 	}
163 
164 	/* If message not newline terminated, need an extra. */
165 	if (!index(line, '\n'))
166 		(void)putc('\n', fp);
167 	/* Output a newline; note, empty messages are allowed. */
168 	(void)putc('\n', fp);
169 
170 	(void)fflush(fp);
171 	if (ferror(fp))
172 		err(FATAL, "temporary file write error");
173 	return(fd);
174 }
175 
176 int
177 deliver(fd, name, lockfile)
178 	int fd;
179 	char *name;
180 	int lockfile;
181 {
182 	struct stat sb;
183 	struct passwd *pw;
184 	int created, mbfd, nr, nw, off, rval=0, lfd=-1;
185 	char biffmsg[100], buf[8*1024], path[MAXPATHLEN], lpath[MAXPATHLEN];
186 	off_t curoff;
187 
188 	/*
189 	 * Disallow delivery to unknown names -- special mailboxes can be
190 	 * handled in the sendmail aliases file.
191 	 */
192 	if (!(pw = getpwnam(name))) {
193 		err(NOTFATAL, "unknown name: %s", name);
194 		return(1);
195 	}
196 
197 	(void)snprintf(path, sizeof path, "%s/%s", _PATH_MAILDIR, name);
198 
199 	if (lockfile) {
200 		(void)snprintf(lpath, sizeof lpath, "%s/%s.lock",
201 		    _PATH_MAILDIR, name);
202 
203 		if((lfd = open(lpath, O_CREAT|O_WRONLY|O_EXCL,
204 		    S_IRUSR|S_IWUSR)) < 0) {
205 			err(NOTFATAL, "%s: %s", lpath, strerror(errno));
206 			return(1);
207 		}
208 	}
209 
210 	if (!(created = lstat(path, &sb)) &&
211 	    (sb.st_nlink != 1 || S_ISLNK(sb.st_mode))) {
212 		err(NOTFATAL, "%s: linked file", path);
213 		return(1);
214 	}
215 	if ((mbfd = open(path, O_APPEND|O_WRONLY|O_EXLOCK,
216 	    S_IRUSR|S_IWUSR)) < 0) {
217 		if ((mbfd = open(path, O_APPEND|O_CREAT|O_WRONLY|O_EXLOCK,
218 		    S_IRUSR|S_IWUSR)) < 0) {
219 			err(NOTFATAL, "%s: %s", path, strerror(errno));
220 			return(1);
221 		}
222 	}
223 
224 	curoff = lseek(mbfd, 0, SEEK_END);
225 	(void)snprintf(biffmsg, sizeof biffmsg, "%s@%lld\n", name,
226 	    (long long)curoff);
227 	if (lseek(fd, 0, SEEK_SET) == (off_t)-1) {
228 		err(FATAL, "temporary file: %s", strerror(errno));
229 		rval = 1;
230 		goto bad;
231 	}
232 
233 	while ((nr = read(fd, buf, sizeof(buf))) > 0)
234 		for (off = 0; off < nr;  off += nw)
235 			if ((nw = write(mbfd, buf + off, nr - off)) < 0) {
236 				err(NOTFATAL, "%s: %s", path, strerror(errno));
237 				goto trunc;
238 			}
239 	if (nr < 0) {
240 		err(FATAL, "temporary file: %s", strerror(errno));
241 trunc:		(void)ftruncate(mbfd, curoff);
242 		rval = 1;
243 	}
244 
245 	/*
246 	 * Set the owner and group.  Historically, binmail repeated this at
247 	 * each mail delivery.  We no longer do this, assuming that if the
248 	 * ownership or permissions were changed there was a reason for doing
249 	 * so.
250 	 */
251 bad:
252 	if (lockfile) {
253 		if (lfd >= 0) {
254 			unlink(lpath);
255 			close(lfd);
256 		}
257 	}
258 	if (created)
259 		(void)fchown(mbfd, pw->pw_uid, pw->pw_gid);
260 
261 	(void)fsync(mbfd);		/* Don't wait for update. */
262 	(void)close(mbfd);		/* Implicit unlock. */
263 
264 	if (!rval)
265 		notifybiff(biffmsg);
266 	return(rval);
267 }
268 
269 void
270 notifybiff(msg)
271 	char *msg;
272 {
273 	static struct sockaddr_in addr;
274 	static int f = -1;
275 	struct hostent *hp;
276 	struct servent *sp;
277 	int len;
278 
279 	if (!addr.sin_family) {
280 		/* Be silent if biff service not available. */
281 		if (!(sp = getservbyname("biff", "udp")))
282 			return;
283 		if (!(hp = gethostbyname("localhost"))) {
284 			err(NOTFATAL, "localhost: %s", strerror(errno));
285 			return;
286 		}
287 		addr.sin_len = sizeof(struct sockaddr_in);
288 		addr.sin_family = hp->h_addrtype;
289 		addr.sin_port = sp->s_port;
290 		memcpy(&addr.sin_addr, hp->h_addr, hp->h_length);
291 	}
292 	if (f < 0 && (f = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
293 		err(NOTFATAL, "socket: %s", strerror(errno));
294 		return;
295 	}
296 	len = strlen(msg) + 1;
297 	if (sendto(f, msg, len, 0, (struct sockaddr *)&addr, sizeof(addr))
298 	    != len)
299 		err(NOTFATAL, "sendto biff: %s", strerror(errno));
300 }
301 
302 void
303 usage()
304 {
305 	err(FATAL, "usage: mail.local [-l] [-f from] user ...");
306 }
307 
308 #if __STDC__
309 #include <stdarg.h>
310 #else
311 #include <varargs.h>
312 #endif
313 
314 void
315 #if __STDC__
316 err(int isfatal, const char *fmt, ...)
317 #else
318 err(isfatal, fmt)
319 	int isfatal;
320 	char *fmt;
321 	va_dcl
322 #endif
323 {
324 	va_list ap;
325 #if __STDC__
326 	va_start(ap, fmt);
327 #else
328 	va_start(ap);
329 #endif
330 	vsyslog(LOG_ERR, fmt, ap);
331 	va_end(ap);
332 	if (isfatal)
333 		exit(1);
334 }
335