xref: /netbsd-src/libexec/mail.local/mail.local.c (revision ae9172d6cd9432a6a1a56760d86b32c57a66c39c)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 char copyright[] =
36 "@(#) Copyright (c) 1990 The Regents of the University of California.\n\
37  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 /*static char sccsid[] = "from: @(#)mail.local.c	5.6 (Berkeley) 6/19/91";*/
42 static char rcsid[] = "$Id: mail.local.c,v 1.8 1994/08/05 23:41:15 jtc Exp $";
43 #endif /* not lint */
44 
45 #include <sys/param.h>
46 #include <sys/stat.h>
47 #include <sys/socket.h>
48 #include <netinet/in.h>
49 #include <syslog.h>
50 #include <fcntl.h>
51 #include <netdb.h>
52 #include <pwd.h>
53 #include <time.h>
54 #include <unistd.h>
55 #include <errno.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include "pathnames.h"
60 
61 #define	FATAL		1
62 #define	NOTFATAL	0
63 
64 int	deliver __P((int, char *, int));
65 void	err __P((int, const char *, ...));
66 void	notifybiff __P((char *));
67 int	store __P((char *));
68 void	usage __P((void));
69 
70 main(argc, argv)
71 	int argc;
72 	char **argv;
73 {
74 	extern int optind;
75 	extern char *optarg;
76 	struct passwd *pw;
77 	int ch, fd, eval, lockfile=0;
78 	uid_t uid;
79 	char *from;
80 
81 	openlog("mail.local", LOG_PERROR, LOG_MAIL);
82 
83 	from = NULL;
84 	while ((ch = getopt(argc, argv, "ldf:r:")) != EOF)
85 		switch(ch) {
86 		case 'd':		/* backward compatible */
87 			break;
88 		case 'f':
89 		case 'r':		/* backward compatible */
90 			if (from)
91 			    err(FATAL, "multiple -f options");
92 			from = optarg;
93 			break;
94 		case 'l':
95 			lockfile++;
96 			break;
97 		case '?':
98 		default:
99 			usage();
100 		}
101 	argc -= optind;
102 	argv += optind;
103 
104 	if (!*argv)
105 		usage();
106 
107 	/*
108 	 * If from not specified, use the name from getlogin() if the
109 	 * uid matches, otherwise, use the name from the password file
110 	 * corresponding to the uid.
111 	 */
112 	uid = getuid();
113 	if (!from && (!(from = getlogin()) ||
114 	    !(pw = getpwnam(from)) || pw->pw_uid != uid))
115 		from = (pw = getpwuid(uid)) ? pw->pw_name : "???";
116 
117 	fd = store(from);
118 	for (eval = 0; *argv; ++argv)
119 		eval |= deliver(fd, *argv, lockfile);
120 	exit(eval);
121 }
122 
123 store(from)
124 	char *from;
125 {
126 	FILE *fp;
127 	time_t tval;
128 	int fd, eline;
129 	char *tn, line[2048];
130 
131 	tn = strdup(_PATH_LOCTMP);
132 	if ((fd = mkstemp(tn)) == -1 || !(fp = fdopen(fd, "w+")))
133 		err(FATAL, "unable to open temporary file");
134 	(void)unlink(tn);
135 	free(tn);
136 
137 	(void)time(&tval);
138 	(void)fprintf(fp, "From %s %s", from, ctime(&tval));
139 
140 	line[0] = '\0';
141 	for (eline = 1; fgets(line, sizeof(line), stdin);) {
142 		if (line[0] == '\n')
143 			eline = 1;
144 		else {
145 			if (eline && line[0] == 'F' && !bcmp(line, "From ", 5))
146 				(void)putc('>', fp);
147 			eline = 0;
148 		}
149 		(void)fprintf(fp, "%s", line);
150 		if (ferror(fp))
151 			break;
152 	}
153 
154 	/* If message not newline terminated, need an extra. */
155 	if (!index(line, '\n'))
156 		(void)putc('\n', fp);
157 	/* Output a newline; note, empty messages are allowed. */
158 	(void)putc('\n', fp);
159 
160 	(void)fflush(fp);
161 	if (ferror(fp))
162 		err(FATAL, "temporary file write error");
163 	return(fd);
164 }
165 
166 deliver(fd, name, lockfile)
167 	int fd;
168 	char *name;
169 	int lockfile;
170 {
171 	struct stat sb;
172 	struct passwd *pw;
173 	int created, mbfd, nr, nw, off, rval=0, lfd=-1;
174 	char biffmsg[100], buf[8*1024], path[MAXPATHLEN], lpath[MAXPATHLEN];
175 	off_t curoff;
176 
177 	/*
178 	 * Disallow delivery to unknown names -- special mailboxes can be
179 	 * handled in the sendmail aliases file.
180 	 */
181 	if (!(pw = getpwnam(name))) {
182 		err(NOTFATAL, "unknown name: %s", name);
183 		return(1);
184 	}
185 
186 	(void)sprintf(path, "%s/%s", _PATH_MAILDIR, name);
187 
188 	if(lockfile) {
189 		(void)sprintf(lpath, "%s/%s.lock", _PATH_MAILDIR, name);
190 
191 		if((lfd = open(lpath, O_CREAT|O_WRONLY|O_EXCL,
192 		    S_IRUSR|S_IWUSR)) < 0) {
193 			err(NOTFATAL, "%s: %s", lpath, strerror(errno));
194 			return(1);
195 		}
196 	}
197 
198 	if (!(created = lstat(path, &sb)) &&
199 	    (sb.st_nlink != 1 || S_ISLNK(sb.st_mode))) {
200 		err(NOTFATAL, "%s: linked file", path);
201 		return(1);
202 	}
203 	if((mbfd = open(path, O_APPEND|O_WRONLY|O_EXLOCK,
204 	    S_IRUSR|S_IWUSR)) < 0) {
205 		if ((mbfd = open(path, O_APPEND|O_CREAT|O_WRONLY|O_EXLOCK,
206 		    S_IRUSR|S_IWUSR)) < 0) {
207 		err(NOTFATAL, "%s: %s", path, strerror(errno));
208 		return(1);
209 	}
210 	}
211 
212 	curoff = lseek(mbfd, 0, SEEK_END);
213 	(void)sprintf(biffmsg, "%s@%qd\n", name, curoff);
214 	if (lseek(fd, 0, SEEK_SET) == (off_t)-1) {
215 		err(FATAL, "temporary file: %s", strerror(errno));
216 		rval = 1;
217 		goto bad;
218 	}
219 
220 	while ((nr = read(fd, buf, sizeof(buf))) > 0)
221 		for (off = 0; off < nr;  off += nw)
222 			if ((nw = write(mbfd, buf + off, nr - off)) < 0) {
223 				err(NOTFATAL, "%s: %s", path, strerror(errno));
224 				goto trunc;
225 			}
226 	if (nr < 0) {
227 		err(FATAL, "temporary file: %s", strerror(errno));
228 trunc:		(void)ftruncate(mbfd, curoff);
229 		rval = 1;
230 	}
231 
232 	/*
233 	 * Set the owner and group.  Historically, binmail repeated this at
234 	 * each mail delivery.  We no longer do this, assuming that if the
235 	 * ownership or permissions were changed there was a reason for doing
236 	 * so.
237 	 */
238 bad:
239 	if(lockfile) {
240 		if(lfd >= 0) {
241 			unlink(lpath);
242 			close(lfd);
243 		}
244 	}
245 	if (created)
246 		(void)fchown(mbfd, pw->pw_uid, pw->pw_gid);
247 
248 	(void)fsync(mbfd);		/* Don't wait for update. */
249 	(void)close(mbfd);		/* Implicit unlock. */
250 
251 	if (!rval)
252 		notifybiff(biffmsg);
253 	return(rval);
254 }
255 
256 void
257 notifybiff(msg)
258 	char *msg;
259 {
260 	static struct sockaddr_in addr;
261 	static int f = -1;
262 	struct hostent *hp;
263 	struct servent *sp;
264 	int len;
265 
266 	if (!addr.sin_family) {
267 		/* Be silent if biff service not available. */
268 		if (!(sp = getservbyname("biff", "udp")))
269 			return;
270 		if (!(hp = gethostbyname("localhost"))) {
271 			err(NOTFATAL, "localhost: %s", strerror(errno));
272 			return;
273 		}
274 		addr.sin_family = hp->h_addrtype;
275 		bcopy(hp->h_addr, &addr.sin_addr, hp->h_length);
276 		addr.sin_port = sp->s_port;
277 	}
278 	if (f < 0 && (f = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
279 		err(NOTFATAL, "socket: %s", strerror(errno));
280 		return;
281 	}
282 	len = strlen(msg) + 1;
283 	if (sendto(f, msg, len, 0, (struct sockaddr *)&addr, sizeof(addr))
284 	    != len)
285 		err(NOTFATAL, "sendto biff: %s", strerror(errno));
286 }
287 
288 void
289 usage()
290 {
291 	err(FATAL, "usage: mail.local [-f from] user ...");
292 }
293 
294 #if __STDC__
295 #include <stdarg.h>
296 #else
297 #include <varargs.h>
298 #endif
299 
300 void
301 #if __STDC__
302 err(int isfatal, const char *fmt, ...)
303 #else
304 err(isfatal, fmt)
305 	int isfatal;
306 	char *fmt;
307 	va_dcl
308 #endif
309 {
310 	va_list ap;
311 #if __STDC__
312 	va_start(ap, fmt);
313 #else
314 	va_start(ap);
315 #endif
316 	vsyslog(LOG_ERR, fmt, ap);
317 	va_end(ap);
318 	if (isfatal)
319 		exit(1);
320 }
321