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vacation.c revision 1.6 
      1 /*	$NetBSD: vacation.c,v 1.6 1994/12/21 07:19:52 jtc Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1983, 1987, 1993
      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 #ifndef lint
     37 static char copyright[] =
     38 "@(#) Copyright (c) 1983, 1987, 1993\n\
     39 	The Regents of the University of California.  All rights reserved.\n";
     40 #endif /* not lint */
     41 
     42 #ifndef lint
     43 #if 0
     44 static char sccsid[] = "@(#)vacation.c	8.2 (Berkeley) 1/26/94";
     45 #endif
     46 static char rcsid[] = "$NetBSD: vacation.c,v 1.6 1994/12/21 07:19:52 jtc Exp $";
     47 #endif /* not lint */
     48 
     49 /*
     50 **  Vacation
     51 **  Copyright (c) 1983  Eric P. Allman
     52 **  Berkeley, California
     53 */
     54 
     55 #include <sys/param.h>
     56 #include <sys/stat.h>
     57 #include <fcntl.h>
     58 #include <pwd.h>
     59 #include <db.h>
     60 #include <time.h>
     61 #include <syslog.h>
     62 #include <tzfile.h>
     63 #include <errno.h>
     64 #include <unistd.h>
     65 #include <stdio.h>
     66 #include <ctype.h>
     67 #include <stdlib.h>
     68 #include <string.h>
     69 #include <paths.h>
     70 
     71 /*
     72  *  VACATION -- return a message to the sender when on vacation.
     73  *
     74  *	This program is invoked as a message receiver.  It returns a
     75  *	message specified by the user to whomever sent the mail, taking
     76  *	care not to return a message too often to prevent "I am on
     77  *	vacation" loops.
     78  */
     79 
     80 #define	MAXLINE	1024			/* max line from mail header */
     81 #define	VDB	".vacation.db"		/* dbm's database */
     82 #define	VMSG	".vacation.msg"		/* vacation message */
     83 
     84 typedef struct alias {
     85 	struct alias *next;
     86 	char *name;
     87 } ALIAS;
     88 ALIAS *names;
     89 
     90 DB *db;
     91 char from[MAXLINE];
     92 
     93 int junkmail __P((void));
     94 int nsearch __P((char *, char *));
     95 void readheaders __P((void));
     96 int recent __P((void));
     97 void sendmessage __P((char *));
     98 void setinterval __P((time_t));
     99 void setreply __P((void));
    100 void usage __P((void));
    101 
    102 int
    103 main(argc, argv)
    104 	int argc;
    105 	char **argv;
    106 {
    107 	extern int optind, opterr;
    108 	extern char *optarg;
    109 	struct passwd *pw;
    110 	ALIAS *cur;
    111 	time_t interval;
    112 	int ch, iflag;
    113 
    114 	opterr = iflag = 0;
    115 	interval = -1;
    116 	while ((ch = getopt(argc, argv, "a:Iir:")) != EOF)
    117 		switch((char)ch) {
    118 		case 'a':			/* alias */
    119 			if (!(cur = (ALIAS *)malloc((u_int)sizeof(ALIAS))))
    120 				break;
    121 			cur->name = optarg;
    122 			cur->next = names;
    123 			names = cur;
    124 			break;
    125 		case 'I':			/* backward compatible */
    126 		case 'i':			/* init the database */
    127 			iflag = 1;
    128 			break;
    129 		case 'r':
    130 			if (isdigit(*optarg)) {
    131 				interval = atol(optarg) * SECSPERDAY;
    132 				if (interval < 0)
    133 					usage();
    134 			}
    135 			else
    136 				interval = LONG_MAX;
    137 			break;
    138 		case '?':
    139 		default:
    140 			usage();
    141 		}
    142 	argc -= optind;
    143 	argv += optind;
    144 
    145 	if (argc != 1) {
    146 		if (!iflag)
    147 			usage();
    148 		if (!(pw = getpwuid(getuid()))) {
    149 			syslog(LOG_ERR,
    150 			    "vacation: no such user uid %u.\n", getuid());
    151 			exit(1);
    152 		}
    153 	}
    154 	else if (!(pw = getpwnam(*argv))) {
    155 		syslog(LOG_ERR, "vacation: no such user %s.\n", *argv);
    156 		exit(1);
    157 	}
    158 	if (chdir(pw->pw_dir)) {
    159 		syslog(LOG_NOTICE,
    160 		    "vacation: no such directory %s.\n", pw->pw_dir);
    161 		exit(1);
    162 	}
    163 
    164 	db = dbopen(VDB, O_CREAT|O_RDWR | (iflag ? O_TRUNC : 0),
    165 	    S_IRUSR|S_IWUSR, DB_HASH, NULL);
    166 	if (!db) {
    167 		syslog(LOG_NOTICE, "vacation: %s: %s\n", VDB, strerror(errno));
    168 		exit(1);
    169 	}
    170 
    171 	if (interval != -1)
    172 		setinterval(interval);
    173 
    174 	if (iflag) {
    175 		(void)(db->close)(db);
    176 		exit(0);
    177 	}
    178 
    179 	if (!(cur = malloc((u_int)sizeof(ALIAS))))
    180 		exit(1);
    181 	cur->name = pw->pw_name;
    182 	cur->next = names;
    183 	names = cur;
    184 
    185 	readheaders();
    186 	if (!recent()) {
    187 		setreply();
    188 		(void)(db->close)(db);
    189 		sendmessage(pw->pw_name);
    190 	}
    191 	else
    192 		(void)(db->close)(db);
    193 	exit(0);
    194 	/* NOTREACHED */
    195 }
    196 
    197 /*
    198  * readheaders --
    199  *	read mail headers
    200  */
    201 void
    202 readheaders()
    203 {
    204 	register ALIAS *cur;
    205 	register char *p;
    206 	int tome, cont;
    207 	char buf[MAXLINE];
    208 
    209 	cont = tome = 0;
    210 	while (fgets(buf, sizeof(buf), stdin) && *buf != '\n')
    211 		switch(*buf) {
    212 		case 'F':		/* "From " */
    213 			cont = 0;
    214 			if (!strncmp(buf, "From ", 5)) {
    215 				for (p = buf + 5; *p && *p != ' '; ++p);
    216 				*p = '\0';
    217 				(void)strcpy(from, buf + 5);
    218 				if (p = index(from, '\n'))
    219 					*p = '\0';
    220 				if (junkmail())
    221 					exit(0);
    222 			}
    223 			break;
    224 		case 'P':		/* "Precedence:" */
    225 			cont = 0;
    226 			if (strncasecmp(buf, "Precedence", 10) ||
    227 			    buf[10] != ':' && buf[10] != ' ' && buf[10] != '\t')
    228 				break;
    229 			if (!(p = index(buf, ':')))
    230 				break;
    231 			while (*++p && isspace(*p));
    232 			if (!*p)
    233 				break;
    234 			if (!strncasecmp(p, "junk", 4) ||
    235 			    !strncasecmp(p, "bulk", 4) ||
    236 			    !strncasecmp(p, "list", 4))
    237 				exit(0);
    238 			break;
    239 		case 'C':		/* "Cc:" */
    240 			if (strncmp(buf, "Cc:", 3))
    241 				break;
    242 			cont = 1;
    243 			goto findme;
    244 		case 'T':		/* "To:" */
    245 			if (strncmp(buf, "To:", 3))
    246 				break;
    247 			cont = 1;
    248 			goto findme;
    249 		default:
    250 			if (!isspace(*buf) || !cont || tome) {
    251 				cont = 0;
    252 				break;
    253 			}
    254 findme:			for (cur = names; !tome && cur; cur = cur->next)
    255 				tome += nsearch(cur->name, buf);
    256 		}
    257 	if (!tome)
    258 		exit(0);
    259 	if (!*from) {
    260 		syslog(LOG_NOTICE, "vacation: no initial \"From\" line.\n");
    261 		exit(1);
    262 	}
    263 }
    264 
    265 /*
    266  * nsearch --
    267  *	do a nice, slow, search of a string for a substring.
    268  */
    269 int
    270 nsearch(name, str)
    271 	register char *name, *str;
    272 {
    273 	register int len;
    274 
    275 	for (len = strlen(name); *str; ++str)
    276 		if (*str == *name && !strncasecmp(name, str, len))
    277 			return(1);
    278 	return(0);
    279 }
    280 
    281 /*
    282  * junkmail --
    283  *	read the header and return if automagic/junk/bulk/list mail
    284  */
    285 int
    286 junkmail()
    287 {
    288 	static struct ignore {
    289 		char	*name;
    290 		int	len;
    291 	} ignore[] = {
    292 		"-request", 8,		"postmaster", 10,	"uucp", 4,
    293 		"mailer-daemon", 13,	"mailer", 6,		"-relay", 6,
    294 		NULL, NULL,
    295 	};
    296 	register struct ignore *cur;
    297 	register int len;
    298 	register char *p;
    299 
    300 	/*
    301 	 * This is mildly amusing, and I'm not positive it's right; trying
    302 	 * to find the "real" name of the sender, assuming that addresses
    303 	 * will be some variant of:
    304 	 *
    305 	 * From site!site!SENDER%site.domain%site.domain (at) site.domain
    306 	 */
    307 	if (!(p = index(from, '%')))
    308 		if (!(p = index(from, '@'))) {
    309 			if (p = rindex(from, '!'))
    310 				++p;
    311 			else
    312 				p = from;
    313 			for (; *p; ++p);
    314 		}
    315 	len = p - from;
    316 	for (cur = ignore; cur->name; ++cur)
    317 		if (len >= cur->len &&
    318 		    !strncasecmp(cur->name, p - cur->len, cur->len))
    319 			return(1);
    320 	return(0);
    321 }
    322 
    323 #define	VIT	"__VACATION__INTERVAL__TIMER__"
    324 
    325 /*
    326  * recent --
    327  *	find out if user has gotten a vacation message recently.
    328  *	use bcopy for machines with alignment restrictions
    329  */
    330 int
    331 recent()
    332 {
    333 	DBT key, data;
    334 	time_t then, next;
    335 
    336 	/* get interval time */
    337 	key.data = VIT;
    338 	key.size = sizeof(VIT);
    339 	if ((db->get)(db, &key, &data, 0))
    340 		next = SECSPERDAY * DAYSPERWEEK;
    341 	else
    342 		bcopy(data.data, &next, sizeof(next));
    343 
    344 	/* get record for this address */
    345 	key.data = from;
    346 	key.size = strlen(from);
    347 	if (!(db->get)(db, &key, &data, 0)) {
    348 		bcopy(data.data, &then, sizeof(then));
    349 		if (next == LONG_MAX || then + next > time(NULL))
    350 			return(1);
    351 	}
    352 	return(0);
    353 }
    354 
    355 /*
    356  * setinterval --
    357  *	store the reply interval
    358  */
    359 void
    360 setinterval(interval)
    361 	time_t interval;
    362 {
    363 	DBT key, data;
    364 
    365 	key.data = VIT;
    366 	key.size = sizeof(VIT);
    367 	data.data = &interval;
    368 	data.size = sizeof(interval);
    369 	(void)(db->put)(db, &key, &data, 0);
    370 }
    371 
    372 /*
    373  * setreply --
    374  *	store that this user knows about the vacation.
    375  */
    376 void
    377 setreply()
    378 {
    379 	DBT key, data;
    380 	time_t now;
    381 
    382 	key.data = from;
    383 	key.size = strlen(from);
    384 	(void)time(&now);
    385 	data.data = &now;
    386 	data.size = sizeof(now);
    387 	(void)(db->put)(db, &key, &data, 0);
    388 }
    389 
    390 /*
    391  * sendmessage --
    392  *	exec sendmail to send the vacation file to sender
    393  */
    394 void
    395 sendmessage(myname)
    396 	char *myname;
    397 {
    398 	FILE *mfp, *sfp;
    399 	int i;
    400 	int pvect[2];
    401 	char buf[MAXLINE];
    402 
    403 	mfp = fopen(VMSG, "r");
    404 	if (mfp == NULL) {
    405 		syslog(LOG_NOTICE, "vacation: no ~%s/%s file.\n", myname, VMSG);
    406 		exit(1);
    407 	}
    408 	if (pipe(pvect) < 0) {
    409 		syslog(LOG_ERR, "vacation: pipe: %s", strerror(errno));
    410 		exit(1);
    411 	}
    412 	i = vfork();
    413 	if (i < 0) {
    414 		syslog(LOG_ERR, "vacation: fork: %s", strerror(errno));
    415 		exit(1);
    416 	}
    417 	if (i == 0) {
    418 		dup2(pvect[0], 0);
    419 		close(pvect[0]);
    420 		close(pvect[1]);
    421 		fclose(mfp);
    422 		execl(_PATH_SENDMAIL, "sendmail", "-f", myname, from, NULL);
    423 		syslog(LOG_ERR, "vacation: can't exec %s: %s",
    424 			_PATH_SENDMAIL, strerror(errno));
    425 		exit(1);
    426 	}
    427 	close(pvect[0]);
    428 	sfp = fdopen(pvect[1], "w");
    429 	fprintf(sfp, "To: %s\n", from);
    430 	while (fgets(buf, sizeof buf, mfp))
    431 		fputs(buf, sfp);
    432 	fclose(mfp);
    433 	fclose(sfp);
    434 }
    435 
    436 void
    437 usage()
    438 {
    439 	syslog(LOG_NOTICE, "uid %u: usage: vacation [-i] [-a alias] login\n",
    440 	    getuid());
    441 	exit(1);
    442 }
    443