xref: /netbsd-src/libexec/mail.local/mail.local.c (revision cda4f8f6ee55684e8d311b86c99ea59191e6b74f)
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[] = "@(#)mail.local.c	5.6 (Berkeley) 6/19/91";
42 #endif /* not lint */
43 
44 #include <sys/param.h>
45 #include <sys/stat.h>
46 #include <sys/socket.h>
47 #include <netinet/in.h>
48 #include <syslog.h>
49 #include <fcntl.h>
50 #include <netdb.h>
51 #include <pwd.h>
52 #include <time.h>
53 #include <unistd.h>
54 #include <errno.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include "pathnames.h"
59 
60 #define	FATAL		1
61 #define	NOTFATAL	0
62 
63 int	deliver __P((int, char *, int));
64 void	err __P((int, const char *, ...));
65 void	notifybiff __P((char *));
66 int	store __P((char *));
67 void	usage __P((void));
68 
69 main(argc, argv)
70 	int argc;
71 	char **argv;
72 {
73 	extern int optind;
74 	extern char *optarg;
75 	struct passwd *pw;
76 	int ch, fd, eval, lockfile=0;
77 	uid_t uid;
78 	char *from;
79 
80 	openlog("mail.local", LOG_PERROR, LOG_MAIL);
81 
82 	from = NULL;
83 	while ((ch = getopt(argc, argv, "df:r:")) != EOF)
84 		switch(ch) {
85 		case 'd':		/* backward compatible */
86 			break;
87 		case 'f':
88 		case 'r':		/* backward compatible */
89 			if (from)
90 			    err(FATAL, "multiple -f options");
91 			from = optarg;
92 			break;
93 		case 'l':
94 			lockfile++;
95 			break;
96 		case '?':
97 		default:
98 			usage();
99 		}
100 	argc -= optind;
101 	argv += optind;
102 
103 	if (!*argv)
104 		usage();
105 
106 	/*
107 	 * If from not specified, use the name from getlogin() if the
108 	 * uid matches, otherwise, use the name from the password file
109 	 * corresponding to the uid.
110 	 */
111 	uid = getuid();
112 	if (!from && (!(from = getlogin()) ||
113 	    !(pw = getpwnam(from)) || pw->pw_uid != uid))
114 		from = (pw = getpwuid(uid)) ? pw->pw_name : "???";
115 
116 	fd = store(from);
117 	for (eval = 0; *argv; ++argv)
118 		eval |= deliver(fd, *argv, lockfile);
119 	exit(eval);
120 }
121 
122 store(from)
123 	char *from;
124 {
125 	FILE *fp;
126 	time_t tval;
127 	int fd, eline;
128 	char *tn, line[2048];
129 
130 	tn = strdup(_PATH_LOCTMP);
131 	if ((fd = mkstemp(tn)) == -1 || !(fp = fdopen(fd, "w+")))
132 		err(FATAL, "unable to open temporary file");
133 	(void)unlink(tn);
134 	free(tn);
135 
136 	(void)time(&tval);
137 	(void)fprintf(fp, "From %s %s", from, ctime(&tval));
138 
139 	line[0] = '\0';
140 	for (eline = 1; fgets(line, sizeof(line), stdin);) {
141 		if (line[0] == '\n')
142 			eline = 1;
143 		else {
144 			if (eline && line[0] == 'F' && !bcmp(line, "From ", 5))
145 				(void)putc('>', fp);
146 			eline = 0;
147 		}
148 		(void)fprintf(fp, "%s", line);
149 		if (ferror(fp))
150 			break;
151 	}
152 
153 	/* If message not newline terminated, need an extra. */
154 	if (!index(line, '\n'))
155 		(void)putc('\n', fp);
156 	/* Output a newline; note, empty messages are allowed. */
157 	(void)putc('\n', fp);
158 
159 	(void)fflush(fp);
160 	if (ferror(fp))
161 		err(FATAL, "temporary file write error");
162 	return(fd);
163 }
164 
165 deliver(fd, name, lockfile)
166 	int fd;
167 	char *name;
168 	int lockfile;
169 {
170 	struct stat sb;
171 	struct passwd *pw;
172 	int created, mbfd, nr, nw, off, rval, lfd=-1;
173 	char biffmsg[100], buf[8*1024], path[MAXPATHLEN], lpath[MAXPATHLEN];
174 	off_t curoff, lseek();
175 
176 	/*
177 	 * Disallow delivery to unknown names -- special mailboxes can be
178 	 * handled in the sendmail aliases file.
179 	 */
180 	if (!(pw = getpwnam(name))) {
181 		err(NOTFATAL, "unknown name: %s", name);
182 		return(1);
183 	}
184 
185 	(void)sprintf(path, "%s/%s", _PATH_MAILDIR, name);
186 
187 	if(lockfile) {
188 		(void)sprintf(lpath, "%s/%s.lock", _PATH_MAILDIR, name);
189 
190 		if((lfd = open(lpath, O_CREAT|O_WRONLY|O_EXCL,
191 		    S_IRUSR|S_IWUSR)) < 0) {
192 			err(NOTFATAL, "%s: %s", lpath, strerror(errno));
193 			return(1);
194 		}
195 	}
196 
197 	if (!(created = lstat(path, &sb)) &&
198 	    (sb.st_nlink != 1 || S_ISLNK(sb.st_mode))) {
199 		err(NOTFATAL, "%s: linked file", path);
200 		return(1);
201 	}
202 	if((mbfd = open(path, O_APPEND|O_WRONLY|O_EXLOCK,
203 	    S_IRUSR|S_IWUSR)) < 0) {
204 		if ((mbfd = open(path, O_APPEND|O_CREAT|O_WRONLY|O_EXLOCK,
205 		    S_IRUSR|S_IWUSR)) < 0) {
206 		err(NOTFATAL, "%s: %s", path, strerror(errno));
207 		return(1);
208 	}
209 	}
210 
211 	curoff = lseek(mbfd, 0L, SEEK_END);
212 	(void)sprintf(biffmsg, "%s@%ld\n", name, curoff);
213 	if (lseek(fd, 0L, SEEK_SET) == (off_t)-1) {
214 		err(FATAL, "temporary file: %s", strerror(errno));
215 		rval = 1;
216 		goto bad;
217 	}
218 
219 	while ((nr = read(fd, buf, sizeof(buf))) > 0)
220 		for (off = 0; off < nr;  off += nw)
221 			if ((nw = write(mbfd, buf + off, nr - off)) < 0) {
222 				err(NOTFATAL, "%s: %s", path, strerror(errno));
223 				goto trunc;
224 			}
225 	if (nr < 0) {
226 		err(FATAL, "temporary file: %s", strerror(errno));
227 trunc:		(void)ftruncate(mbfd, curoff);
228 		rval = 1;
229 	}
230 
231 	/*
232 	 * Set the owner and group.  Historically, binmail repeated this at
233 	 * each mail delivery.  We no longer do this, assuming that if the
234 	 * ownership or permissions were changed there was a reason for doing
235 	 * so.
236 	 */
237 bad:
238 	if(lockfile) {
239 		if(lfd >= 0) {
240 			unlink(lpath);
241 			close(lfd);
242 		}
243 	}
244 	if (created)
245 		(void)fchown(mbfd, pw->pw_uid, pw->pw_gid);
246 
247 	(void)fsync(mbfd);		/* Don't wait for update. */
248 	(void)close(mbfd);		/* Implicit unlock. */
249 
250 	if (!rval)
251 		notifybiff(biffmsg);
252 	return(rval);
253 }
254 
255 void
256 notifybiff(msg)
257 	char *msg;
258 {
259 	static struct sockaddr_in addr;
260 	static int f = -1;
261 	struct hostent *hp;
262 	struct servent *sp;
263 	int len;
264 
265 	if (!addr.sin_family) {
266 		/* Be silent if biff service not available. */
267 		if (!(sp = getservbyname("biff", "udp")))
268 			return;
269 		if (!(hp = gethostbyname("localhost"))) {
270 			err(NOTFATAL, "localhost: %s", strerror(errno));
271 			return;
272 		}
273 		addr.sin_family = hp->h_addrtype;
274 		bcopy(hp->h_addr, &addr.sin_addr, hp->h_length);
275 		addr.sin_port = sp->s_port;
276 	}
277 	if (f < 0 && (f = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
278 		err(NOTFATAL, "socket: %s", strerror(errno));
279 		return;
280 	}
281 	len = strlen(msg) + 1;
282 	if (sendto(f, msg, len, 0, (struct sockaddr *)&addr, sizeof(addr))
283 	    != len)
284 		err(NOTFATAL, "sendto biff: %s", strerror(errno));
285 }
286 
287 void
288 usage()
289 {
290 	err(FATAL, "usage: mail.local [-f from] user ...");
291 }
292 
293 #if __STDC__
294 #include <stdarg.h>
295 #else
296 #include <varargs.h>
297 #endif
298 
299 void
300 #if __STDC__
301 err(int isfatal, const char *fmt, ...)
302 #else
303 err(isfatal, fmt)
304 	int isfatal;
305 	char *fmt;
306 	va_dcl
307 #endif
308 {
309 	va_list ap;
310 #if __STDC__
311 	va_start(ap, fmt);
312 #else
313 	va_start(ap);
314 #endif
315 	vsyslog(LOG_ERR, fmt, ap);
316 	va_end(ap);
317 	if (isfatal)
318 		exit(1);
319 }
320