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mail.local.c revision 1.12 
      1 /*	$NetBSD: mail.local.c,v 1.12 1997/10/07 13:13:41 mrg 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 1.12 1997/10/07 13:13:41 mrg 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 void	notifybiff __P((char *));
     72 int	store __P((char *));
     73 void	usage __P((void));
     74 int	main __P((int, char **));
     75 
     76 int
     77 main(argc, argv)
     78 	int argc;
     79 	char **argv;
     80 {
     81 	struct passwd *pw;
     82 	int ch, fd, eval, lockfile = 0;
     83 	uid_t uid;
     84 	char *from;
     85 
     86 	/* use a reasonable umask */
     87 	(void) umask(0077);
     88 
     89 	openlog("mail.local", LOG_PERROR, LOG_MAIL);
     90 
     91 	from = NULL;
     92 	while ((ch = getopt(argc, argv, "ldf:r:")) != EOF)
     93 		switch(ch) {
     94 		case 'd':		/* backward compatible */
     95 			break;
     96 		case 'f':
     97 		case 'r':		/* backward compatible */
     98 			if (from)
     99 				err(FATAL, "multiple -f options");
    100 			from = optarg;
    101 			break;
    102 		case 'l':
    103 			lockfile++;
    104 			break;
    105 		case '?':
    106 		default:
    107 			usage();
    108 		}
    109 	argc -= optind;
    110 	argv += optind;
    111 
    112 	if (!*argv)
    113 		usage();
    114 
    115 	/*
    116 	 * If from not specified, use the name from getlogin() if the
    117 	 * uid matches, otherwise, use the name from the password file
    118 	 * corresponding to the uid.
    119 	 */
    120 	uid = getuid();
    121 	if (!from && (!(from = getlogin()) ||
    122 	    !(pw = getpwnam(from)) || pw->pw_uid != uid))
    123 		from = (pw = getpwuid(uid)) ? pw->pw_name : "???";
    124 
    125 	fd = store(from);
    126 	for (eval = 0; *argv; ++argv)
    127 		eval |= deliver(fd, *argv, lockfile);
    128 	exit (eval);
    129 }
    130 
    131 int
    132 store(from)
    133 	char *from;
    134 {
    135 	FILE *fp = NULL;	/* XXX gcc */
    136 	time_t tval;
    137 	int fd, eline;
    138 	char *tn, line[2048];
    139 
    140 	tn = strdup(_PATH_LOCTMP);
    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' && !bcmp(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 	return(fd);
    173 }
    174 
    175 int
    176 deliver(fd, name, lockfile)
    177 	int fd;
    178 	char *name;
    179 	int lockfile;
    180 {
    181 	struct stat sb;
    182 	struct passwd *pw;
    183 	int created, mbfd, nr, nw, off, rval=0, lfd=-1;
    184 	char biffmsg[100], buf[8*1024], path[MAXPATHLEN], lpath[MAXPATHLEN];
    185 	off_t curoff;
    186 
    187 	/*
    188 	 * Disallow delivery to unknown names -- special mailboxes can be
    189 	 * handled in the sendmail aliases file.
    190 	 */
    191 	if (!(pw = getpwnam(name))) {
    192 		err(NOTFATAL, "unknown name: %s", name);
    193 		return(1);
    194 	}
    195 
    196 	(void)snprintf(path, sizeof path, "%s/%s", _PATH_MAILDIR, name);
    197 
    198 	if (lockfile) {
    199 		(void)snprintf(lpath, sizeof lpath, "%s/%s.lock",
    200 		    _PATH_MAILDIR, name);
    201 
    202 		if((lfd = open(lpath, O_CREAT|O_WRONLY|O_EXCL,
    203 		    S_IRUSR|S_IWUSR)) < 0) {
    204 			err(NOTFATAL, "%s: %s", lpath, strerror(errno));
    205 			return(1);
    206 		}
    207 	}
    208 
    209 	if (!(created = lstat(path, &sb)) &&
    210 	    (sb.st_nlink != 1 || S_ISLNK(sb.st_mode))) {
    211 		err(NOTFATAL, "%s: linked file", path);
    212 		return(1);
    213 	}
    214 	if ((mbfd = open(path, O_APPEND|O_WRONLY|O_EXLOCK,
    215 	    S_IRUSR|S_IWUSR)) < 0) {
    216 		if ((mbfd = open(path, O_APPEND|O_CREAT|O_WRONLY|O_EXLOCK,
    217 		    S_IRUSR|S_IWUSR)) < 0) {
    218 			err(NOTFATAL, "%s: %s", path, strerror(errno));
    219 			return(1);
    220 		}
    221 	}
    222 
    223 	curoff = lseek(mbfd, 0, SEEK_END);
    224 	(void)snprintf(biffmsg, sizeof biffmsg, "%s@%qd\n", name,
    225 	    (long long)curoff);
    226 	if (lseek(fd, 0, SEEK_SET) == (off_t)-1) {
    227 		err(FATAL, "temporary file: %s", strerror(errno));
    228 		rval = 1;
    229 		goto bad;
    230 	}
    231 
    232 	while ((nr = read(fd, buf, sizeof(buf))) > 0)
    233 		for (off = 0; off < nr;  off += nw)
    234 			if ((nw = write(mbfd, buf + off, nr - off)) < 0) {
    235 				err(NOTFATAL, "%s: %s", path, strerror(errno));
    236 				goto trunc;
    237 			}
    238 	if (nr < 0) {
    239 		err(FATAL, "temporary file: %s", strerror(errno));
    240 trunc:		(void)ftruncate(mbfd, curoff);
    241 		rval = 1;
    242 	}
    243 
    244 	/*
    245 	 * Set the owner and group.  Historically, binmail repeated this at
    246 	 * each mail delivery.  We no longer do this, assuming that if the
    247 	 * ownership or permissions were changed there was a reason for doing
    248 	 * so.
    249 	 */
    250 bad:
    251 	if (lockfile) {
    252 		if (lfd >= 0) {
    253 			unlink(lpath);
    254 			close(lfd);
    255 		}
    256 	}
    257 	if (created)
    258 		(void)fchown(mbfd, pw->pw_uid, pw->pw_gid);
    259 
    260 	(void)fsync(mbfd);		/* Don't wait for update. */
    261 	(void)close(mbfd);		/* Implicit unlock. */
    262 
    263 	if (!rval)
    264 		notifybiff(biffmsg);
    265 	return(rval);
    266 }
    267 
    268 void
    269 notifybiff(msg)
    270 	char *msg;
    271 {
    272 	static struct sockaddr_in addr;
    273 	static int f = -1;
    274 	struct hostent *hp;
    275 	struct servent *sp;
    276 	int len;
    277 
    278 	if (!addr.sin_family) {
    279 		/* Be silent if biff service not available. */
    280 		if (!(sp = getservbyname("biff", "udp")))
    281 			return;
    282 		if (!(hp = gethostbyname("localhost"))) {
    283 			err(NOTFATAL, "localhost: %s", strerror(errno));
    284 			return;
    285 		}
    286 		addr.sin_len = sizeof(struct sockaddr_in);
    287 		addr.sin_family = hp->h_addrtype;
    288 		addr.sin_port = sp->s_port;
    289 		bcopy(hp->h_addr, &addr.sin_addr, hp->h_length);
    290 	}
    291 	if (f < 0 && (f = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
    292 		err(NOTFATAL, "socket: %s", strerror(errno));
    293 		return;
    294 	}
    295 	len = strlen(msg) + 1;
    296 	if (sendto(f, msg, len, 0, (struct sockaddr *)&addr, sizeof(addr))
    297 	    != len)
    298 		err(NOTFATAL, "sendto biff: %s", strerror(errno));
    299 }
    300 
    301 void
    302 usage()
    303 {
    304 	err(FATAL, "usage: mail.local [-f from] user ...");
    305 }
    306 
    307 #if __STDC__
    308 #include <stdarg.h>
    309 #else
    310 #include <varargs.h>
    311 #endif
    312 
    313 void
    314 #if __STDC__
    315 err(int isfatal, const char *fmt, ...)
    316 #else
    317 err(isfatal, fmt)
    318 	int isfatal;
    319 	char *fmt;
    320 	va_dcl
    321 #endif
    322 {
    323 	va_list ap;
    324 #if __STDC__
    325 	va_start(ap, fmt);
    326 #else
    327 	va_start(ap);
    328 #endif
    329 	vsyslog(LOG_ERR, fmt, ap);
    330 	va_end(ap);
    331 	if (isfatal)
    332 		exit(1);
    333 }
    334