xref: /netbsd-src/libexec/mail.local/mail.local.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: mail.local.c,v 1.23 2006/09/27 17:15:20 christos 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\n\
35 	The Regents of the University of California.  All rights reserved.\n");
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 1.23 2006/09/27 17:15:20 christos 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 
61 #include "pathnames.h"
62 
63 #define	FATAL		1
64 #define	NOTFATAL	0
65 
66 int	deliver __P((int, char *, int));
67 void	err __P((int, const char *, ...))
68      __attribute__((__format__(__printf__, 2, 3)));
69 void	notifybiff __P((char *));
70 int	store __P((const char *));
71 void	usage __P((void));
72 int	main __P((int, char **));
73 
74 int
75 main(argc, argv)
76 	int argc;
77 	char **argv;
78 {
79 	struct passwd *pw;
80 	int ch, fd, eval, lockfile = 0;
81 	uid_t uid;
82 	const char *from;
83 
84 	/* use a reasonable umask */
85 	(void) umask(0077);
86 
87 	openlog("mail.local", LOG_PERROR, LOG_MAIL);
88 
89 	from = NULL;
90 	while ((ch = getopt(argc, argv, "ldf:r:")) != -1)
91 		switch (ch) {
92 		case 'd':		/* backward compatible */
93 			break;
94 		case 'f':
95 		case 'r':		/* backward compatible */
96 			if (from)
97 				err(FATAL, "multiple -f options");
98 			from = optarg;
99 			break;
100 		case 'l':
101 			lockfile++;
102 			break;
103 		case '?':
104 		default:
105 			usage();
106 		}
107 	argc -= optind;
108 	argv += optind;
109 
110 	if (!*argv)
111 		usage();
112 
113 	/*
114 	 * If from not specified, use the name from getlogin() if the
115 	 * uid matches, otherwise, use the name from the password file
116 	 * corresponding to the uid.
117 	 */
118 	uid = getuid();
119 	if (!from && (!(from = getlogin()) ||
120 	    !(pw = getpwnam(from)) || pw->pw_uid != uid))
121 		from = (pw = getpwuid(uid)) ? pw->pw_name : "???";
122 
123 	fd = store(from);
124 	for (eval = 0; *argv; ++argv)
125 		eval |= deliver(fd, *argv, lockfile);
126 	exit (eval);
127 }
128 
129 int
130 store(from)
131 	const char *from;
132 {
133 	FILE *fp = NULL;	/* XXX gcc */
134 	time_t tval;
135 	int fd, eline;
136 	char *tn, line[2048];
137 
138 	tn = strdup(_PATH_LOCTMP);
139 	if (!tn)
140 		err(FATAL, "not enough core");
141 	if ((fd = mkstemp(tn)) == -1 || !(fp = fdopen(fd, "w+")))
142 		err(FATAL, "unable to open temporary file");
143 	(void)unlink(tn);
144 	free(tn);
145 
146 	(void)time(&tval);
147 	(void)fprintf(fp, "From %s %s", from, ctime(&tval));
148 
149 	line[0] = '\0';
150 	for (eline = 1; fgets(line, sizeof(line), stdin);) {
151 		if (line[0] == '\n')
152 			eline = 1;
153 		else {
154 			if (eline && line[0] == 'F' && !memcmp(line, "From ", 5))
155 				(void)putc('>', fp);
156 			eline = 0;
157 		}
158 		(void)fprintf(fp, "%s", line);
159 		if (ferror(fp))
160 			break;
161 	}
162 
163 	/* If message not newline terminated, need an extra. */
164 	if (!index(line, '\n'))
165 		(void)putc('\n', fp);
166 	/* Output a newline; note, empty messages are allowed. */
167 	(void)putc('\n', fp);
168 
169 	(void)fflush(fp);
170 	if (ferror(fp))
171 		err(FATAL, "temporary file write error");
172 	fd = dup(fd);
173 	(void)fclose(fp);
174 	return(fd);
175 }
176 
177 int
178 deliver(fd, name, lockfile)
179 	int fd;
180 	char *name;
181 	int lockfile;
182 {
183 	struct stat sb;
184 	struct passwd *pw;
185 	int created, mbfd, nr, nw, off, rval=0, lfd=-1;
186 	char biffmsg[100], buf[8*1024], path[MAXPATHLEN], lpath[MAXPATHLEN];
187 	off_t curoff;
188 
189 	/*
190 	 * Disallow delivery to unknown names -- special mailboxes can be
191 	 * handled in the sendmail aliases file.
192 	 */
193 	if (!(pw = getpwnam(name))) {
194 		err(NOTFATAL, "unknown name: %s", name);
195 		return(1);
196 	}
197 
198 	(void)snprintf(path, sizeof path, "%s/%s", _PATH_MAILDIR, name);
199 
200 	if (lockfile) {
201 		(void)snprintf(lpath, sizeof lpath, "%s/%s.lock",
202 		    _PATH_MAILDIR, name);
203 
204 		if((lfd = open(lpath, O_CREAT|O_WRONLY|O_EXCL,
205 		    S_IRUSR|S_IWUSR)) < 0) {
206 			err(NOTFATAL, "%s: %s", lpath, strerror(errno));
207 			return(1);
208 		}
209 	}
210 
211 	if (!(created = lstat(path, &sb)) &&
212 	    (sb.st_nlink != 1 || S_ISLNK(sb.st_mode))) {
213 		err(NOTFATAL, "%s: linked file", path);
214 		return(1);
215 	}
216 	if ((mbfd = open(path, O_APPEND|O_WRONLY|O_EXLOCK,
217 	    S_IRUSR|S_IWUSR)) < 0) {
218 		if ((mbfd = open(path, O_APPEND|O_CREAT|O_WRONLY|O_EXLOCK,
219 		    S_IRUSR|S_IWUSR)) < 0) {
220 			err(NOTFATAL, "%s: %s", path, strerror(errno));
221 			return(1);
222 		}
223 	}
224 
225 	curoff = lseek(mbfd, 0, SEEK_END);
226 	(void)snprintf(biffmsg, sizeof biffmsg, "%s@%lld\n", name,
227 	    (long long)curoff);
228 	if (lseek(fd, 0, SEEK_SET) == (off_t)-1) {
229 		err(FATAL, "temporary file: %s", strerror(errno));
230 		rval = 1;
231 		goto bad;
232 	}
233 
234 	while ((nr = read(fd, buf, sizeof(buf))) > 0)
235 		for (off = 0; off < nr;  off += nw)
236 			if ((nw = write(mbfd, buf + off, nr - off)) < 0) {
237 				err(NOTFATAL, "%s: %s", path, strerror(errno));
238 				goto trunc;
239 			}
240 	if (nr < 0) {
241 		err(FATAL, "temporary file: %s", strerror(errno));
242 trunc:		(void)ftruncate(mbfd, curoff);
243 		rval = 1;
244 	}
245 
246 	/*
247 	 * Set the owner and group.  Historically, binmail repeated this at
248 	 * each mail delivery.  We no longer do this, assuming that if the
249 	 * ownership or permissions were changed there was a reason for doing
250 	 * so.
251 	 */
252 bad:
253 	if (lockfile) {
254 		if (lfd >= 0) {
255 			unlink(lpath);
256 			close(lfd);
257 		}
258 	}
259 	if (created)
260 		(void)fchown(mbfd, pw->pw_uid, pw->pw_gid);
261 
262 	(void)fsync(mbfd);		/* Don't wait for update. */
263 	(void)close(mbfd);		/* Implicit unlock. */
264 
265 	if (!rval)
266 		notifybiff(biffmsg);
267 	return(rval);
268 }
269 
270 void
271 notifybiff(msg)
272 	char *msg;
273 {
274 	static struct sockaddr_in addr;
275 	static int f = -1;
276 	struct hostent *hp;
277 	struct servent *sp;
278 	int len;
279 
280 	if (!addr.sin_family) {
281 		/* Be silent if biff service not available. */
282 		if (!(sp = getservbyname("biff", "udp")))
283 			return;
284 		if (!(hp = gethostbyname("localhost"))) {
285 			err(NOTFATAL, "localhost: %s", strerror(errno));
286 			return;
287 		}
288 		addr.sin_len = sizeof(struct sockaddr_in);
289 		addr.sin_family = hp->h_addrtype;
290 		addr.sin_port = sp->s_port;
291 		memcpy(&addr.sin_addr, hp->h_addr, hp->h_length);
292 	}
293 	if (f < 0 && (f = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
294 		err(NOTFATAL, "socket: %s", strerror(errno));
295 		return;
296 	}
297 	len = strlen(msg) + 1;
298 	if (sendto(f, msg, len, 0, (struct sockaddr *)&addr, sizeof(addr))
299 	    != len)
300 		err(NOTFATAL, "sendto biff: %s", strerror(errno));
301 }
302 
303 void
304 usage()
305 {
306 	err(FATAL, "usage: mail.local [-l] [-f from] user ...");
307 }
308 
309 void
310 err(int isfatal, const char *fmt, ...)
311 {
312 	va_list ap;
313 
314 	va_start(ap, fmt);
315 	vsyslog(LOG_ERR, fmt, ap);
316 	va_end(ap);
317 	if (isfatal)
318 		exit(1);
319 }
320