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vacation.c revision 1.35
      1 /*	$NetBSD: vacation.c,v 1.35 2007/12/15 19:44:54 perry 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. 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 
     34 #ifndef lint
     35 __COPYRIGHT("@(#) Copyright (c) 1983, 1987, 1993\n\
     36 	The Regents of the University of California.  All rights reserved.\n");
     37 #endif /* not lint */
     38 
     39 #ifndef lint
     40 #if 0
     41 static char sccsid[] = "@(#)vacation.c	8.2 (Berkeley) 1/26/94";
     42 #endif
     43 __RCSID("$NetBSD: vacation.c,v 1.35 2007/12/15 19:44:54 perry Exp $");
     44 #endif /* not lint */
     45 
     46 /*
     47 **  Vacation
     48 **  Copyright (c) 1983  Eric P. Allman
     49 **  Berkeley, California
     50 */
     51 
     52 #include <sys/param.h>
     53 #include <sys/stat.h>
     54 
     55 #include <ctype.h>
     56 #include <db.h>
     57 #include <err.h>
     58 #include <errno.h>
     59 #include <fcntl.h>
     60 #include <paths.h>
     61 #include <pwd.h>
     62 #include <stdio.h>
     63 #include <stdlib.h>
     64 #include <string.h>
     65 #include <syslog.h>
     66 #include <time.h>
     67 #include <tzfile.h>
     68 #include <unistd.h>
     69 
     70 /*
     71  *  VACATION -- return a message to the sender when on vacation.
     72  *
     73  *	This program is invoked as a message receiver.  It returns a
     74  *	message specified by the user to whomever sent the mail, taking
     75  *	care not to return a message too often to prevent "I am on
     76  *	vacation" loops.
     77  */
     78 
     79 #define	MAXLINE	1024			/* max line from mail header */
     80 
     81 static const char *dbprefix = ".vacation";	/* dbm's database sans .db */
     82 static const char *msgfile = ".vacation.msg";	/* vacation message */
     83 
     84 typedef struct alias {
     85 	struct alias *next;
     86 	const char *name;
     87 } alias_t;
     88 static alias_t *names;
     89 
     90 static DB *db;
     91 static char from[MAXLINE];
     92 static char subject[MAXLINE];
     93 
     94 static int iflag = 0;		/* Initialize the database */
     95 
     96 static int tflag = 0;
     97 #define	APPARENTLY_TO		1
     98 #define	DELIVERED_TO		2
     99 
    100 static int fflag = 0;
    101 #define	FROM_FROM		1
    102 #define	RETURN_PATH_FROM	2
    103 #define	SENDER_FROM		4
    104 
    105 static int toanybody = 0;	/* Don't check if we appear in the to or cc */
    106 
    107 static int debug = 0;
    108 
    109 static void opendb(void);
    110 static int junkmail(const char *);
    111 static int nsearch(const char *, const char *);
    112 static int readheaders(void);
    113 static int recent(void);
    114 static void getfrom(char *);
    115 static void sendmessage(const char *);
    116 static void setinterval(time_t);
    117 static void setreply(void);
    118 static void usage(void) __dead;
    119 
    120 int
    121 main(int argc, char **argv)
    122 {
    123 	struct passwd *pw;
    124 	alias_t *cur;
    125 	long interval;
    126 	int ch, rv;
    127 	char *p;
    128 
    129 	setprogname(argv[0]);
    130 	opterr = 0;
    131 	interval = -1;
    132 	openlog(getprogname(), 0, LOG_USER);
    133 	while ((ch = getopt(argc, argv, "a:df:F:Iijm:r:s:t:T:")) != -1)
    134 		switch((char)ch) {
    135 		case 'a':			/* alias */
    136 			if (!(cur = (alias_t *)malloc((size_t)sizeof(alias_t))))
    137 				break;
    138 			cur->name = optarg;
    139 			cur->next = names;
    140 			names = cur;
    141 			break;
    142 		case 'd':
    143 			debug++;
    144 			break;
    145 		case 'F':
    146 			for (p = optarg; *p; p++)
    147 				switch (*p) {
    148 				case 'F':
    149 					fflag |= FROM_FROM;
    150 					break;
    151 				case 'R':
    152 					fflag |= RETURN_PATH_FROM;
    153 					break;
    154 				case 'S':
    155 					fflag |= SENDER_FROM;
    156 					break;
    157 				default:
    158 					errx(1, "Unknown -f option `%c'", *p);
    159 				}
    160 			break;
    161 		case 'f':
    162 			dbprefix = optarg;
    163 			break;
    164 		case 'I':			/* backward compatible */
    165 		case 'i':			/* init the database */
    166 			iflag = 1;
    167 			break;
    168 		case 'j':
    169 			toanybody = 1;
    170 			break;
    171 		case 'm':
    172 			msgfile = optarg;
    173 			break;
    174 		case 'r':
    175 		case 't':	/* Solaris compatibility */
    176 			if (!isdigit((unsigned char)*optarg)) {
    177 				interval = LONG_MAX;
    178 				break;
    179 			}
    180 			if (*optarg == '\0')
    181 				goto bad;
    182 			interval = strtol(optarg, &p, 0);
    183 			if (errno == ERANGE &&
    184 			    (interval == LONG_MAX || interval == LONG_MIN))
    185 				err(1, "Bad interval `%s'", optarg);
    186 			switch (*p) {
    187 			case 's':
    188 				break;
    189 			case 'm':
    190 				interval *= SECSPERMIN;
    191 				break;
    192 			case 'h':
    193 				interval *= SECSPERHOUR;
    194 				break;
    195 			case 'd':
    196 			case '\0':
    197 				interval *= SECSPERDAY;
    198 				break;
    199 			case 'w':
    200 				interval *= DAYSPERWEEK * SECSPERDAY;
    201 				break;
    202 			default:
    203 			bad:
    204 				errx(1, "Invalid interval `%s'", optarg);
    205 			}
    206 			if (interval < 0 || (*p && p[1]))
    207 				goto bad;
    208 			break;
    209 		case 's':
    210 			(void)strlcpy(from, optarg, sizeof(from));
    211 			break;
    212 		case 'T':
    213 			for (p = optarg; *p; p++)
    214 				switch (*p) {
    215 				case 'A':
    216 					tflag |= APPARENTLY_TO;
    217 					break;
    218 				case 'D':
    219 					tflag |= DELIVERED_TO;
    220 					break;
    221 				default:
    222 					errx(1, "Unknown -t option `%c'", *p);
    223 				}
    224 			break;
    225 		case '?':
    226 		default:
    227 			usage();
    228 		}
    229 	argc -= optind;
    230 	argv += optind;
    231 
    232 	if (argc != 1) {
    233 		if (!iflag)
    234 			usage();
    235 		if (!(pw = getpwuid(getuid()))) {
    236 			syslog(LOG_ERR, "%s: no such user uid %u.",
    237 			    getprogname(), getuid());
    238 			exit(1);
    239 		}
    240 	}
    241 	else if (!(pw = getpwnam(*argv))) {
    242 		syslog(LOG_ERR, "%s: no such user %s.",
    243 		    getprogname(), *argv);
    244 		exit(1);
    245 	}
    246 	if (chdir(pw->pw_dir) == -1 &&
    247 	    (dbprefix[0] != '/' || msgfile[0] != '/')) {
    248 		syslog(LOG_ERR, "%s: no such directory %s.",
    249 		    getprogname(), pw->pw_dir);
    250 		exit(1);
    251 	}
    252 
    253 	opendb();
    254 
    255 	if (interval != -1)
    256 		setinterval((time_t)interval);
    257 
    258 	if (iflag) {
    259 		(void)(db->close)(db);
    260 		exit(0);
    261 	}
    262 
    263 	if (!(cur = malloc((size_t)sizeof(alias_t)))) {
    264 		syslog(LOG_ERR, "%s: %m", getprogname());
    265 		(void)(db->close)(db);
    266 		exit(1);
    267 	}
    268 	cur->name = pw->pw_name;
    269 	cur->next = names;
    270 	names = cur;
    271 
    272 	if ((rv = readheaders()) != -1) {
    273 		(void)(db->close)(db);
    274 		exit(rv);
    275 	}
    276 
    277 	if (!recent()) {
    278 		setreply();
    279 		(void)(db->close)(db);
    280 		sendmessage(pw->pw_name);
    281 	}
    282 	else
    283 		(void)(db->close)(db);
    284 	exit(0);
    285 	/* NOTREACHED */
    286 }
    287 
    288 static void
    289 opendb(void)
    290 {
    291 	char path[MAXPATHLEN];
    292 
    293 	(void)snprintf(path, sizeof(path), "%s.db", dbprefix);
    294 	db = dbopen(path, O_CREAT|O_RDWR | (iflag ? O_TRUNC : 0),
    295 	    S_IRUSR|S_IWUSR, DB_HASH, NULL);
    296 
    297 	if (!db) {
    298 		syslog(LOG_ERR, "%s: %s: %m", getprogname(), path);
    299 		exit(1);
    300 	}
    301 }
    302 
    303 /*
    304  * readheaders --
    305  *	read mail headers
    306  */
    307 static int
    308 readheaders(void)
    309 {
    310 	alias_t *cur;
    311 	char *p;
    312 	int tome, cont;
    313 	char buf[MAXLINE];
    314 
    315 	cont = tome = 0;
    316 #define COMPARE(a, b)		strncmp(a, b, sizeof(b) - 1)
    317 #define CASECOMPARE(a, b)	strncasecmp(a, b, sizeof(b) - 1)
    318 	while (fgets(buf, sizeof(buf), stdin) && *buf != '\n')
    319 		switch(*buf) {
    320 		case 'F':		/* "From " or "From:" */
    321 			cont = 0;
    322 			if (COMPARE(buf, "From ") == 0)
    323 				getfrom(buf + sizeof("From ") - 1);
    324 			if ((fflag & FROM_FROM) != 0 &&
    325 			    COMPARE(buf, "From:") == 0)
    326 				getfrom(buf + sizeof("From:") - 1);
    327 			break;
    328 		case 'P':		/* "Precedence:" */
    329 			cont = 0;
    330 			if (CASECOMPARE(buf, "Precedence") != 0 ||
    331 			    (buf[10] != ':' && buf[10] != ' ' &&
    332 			    buf[10] != '\t'))
    333 				break;
    334 			if ((p = strchr(buf, ':')) == NULL)
    335 				break;
    336 			while (*++p && isspace((unsigned char)*p))
    337 				continue;
    338 			if (!*p)
    339 				break;
    340 			if (CASECOMPARE(p, "junk") == 0 ||
    341 			    CASECOMPARE(p, "bulk") == 0||
    342 			    CASECOMPARE(p, "list") == 0)
    343 				exit(0);
    344 			break;
    345 		case 'C':		/* "Cc:" */
    346 			if (COMPARE(buf, "Cc:"))
    347 				break;
    348 			cont = 1;
    349 			goto findme;
    350 		case 'T':		/* "To:" */
    351 			if (COMPARE(buf, "To:"))
    352 				break;
    353 			cont = 1;
    354 			goto findme;
    355 		case 'A':		/* "Apparently-To:" */
    356 			if ((tflag & APPARENTLY_TO) == 0 ||
    357 			    COMPARE(buf, "Apparently-To:") != 0)
    358 				break;
    359 			cont = 1;
    360 			goto findme;
    361 		case 'D':		/* "Delivered-To:" */
    362 			if ((tflag & DELIVERED_TO) == 0 ||
    363 			    COMPARE(buf, "Delivered-To:") != 0)
    364 				break;
    365 			cont = 1;
    366 			goto findme;
    367 		case 'R':		/* "Return-Path:" */
    368 			cont = 0;
    369 			if ((fflag & RETURN_PATH_FROM) != 0 &&
    370 			    COMPARE(buf, "Return-Path:") == 0)
    371 				getfrom(buf + sizeof("Return-Path:") - 1);
    372 			break;
    373 		case 'S':		/* "Sender:" */
    374 			cont = 0;
    375 			if (COMPARE(buf, "Subject:") == 0) {
    376 				/* trim leading blanks */
    377 				char *s = NULL;
    378 				for (p = buf + sizeof("Subject:") - 1; *p; p++)
    379 					if (s == NULL &&
    380 					    !isspace((unsigned char)*p))
    381 						s = p;
    382 				/* trim trailing blanks */
    383 				if (s) {
    384 					for (--p; p != s; p--)
    385 						if (!isspace((unsigned char)*p))
    386 							break;
    387 					*++p = '\0';
    388 				}
    389 				if (s) {
    390 					(void)strlcpy(subject, s, sizeof(subject));
    391 				} else {
    392 					subject[0] = '\0';
    393 				}
    394 			}
    395 			if ((fflag & SENDER_FROM) != 0 &&
    396 			    COMPARE(buf, "Sender:") == 0)
    397 				getfrom(buf + sizeof("Sender:") - 1);
    398 			break;
    399 		default:
    400 			if (!isspace((unsigned char)*buf) || !cont || tome) {
    401 				cont = 0;
    402 				break;
    403 			}
    404 findme:			for (cur = names; !tome && cur; cur = cur->next)
    405 				tome += nsearch(cur->name, buf);
    406 		}
    407 	if (!toanybody && !tome)
    408 		return 0;
    409 	if (!*from) {
    410 		syslog(LOG_ERR, "%s: no initial \"From\" line.",
    411 			getprogname());
    412 		return 1;
    413 	}
    414 	return -1;
    415 }
    416 
    417 /*
    418  * nsearch --
    419  *	do a nice, slow, search of a string for a substring.
    420  */
    421 static int
    422 nsearch(const char *name, const char *str)
    423 {
    424 	size_t len;
    425 
    426 	for (len = strlen(name); *str; ++str)
    427 		if (!strncasecmp(name, str, len))
    428 			return(1);
    429 	return(0);
    430 }
    431 
    432 /*
    433  * getfrom --
    434  *	return the first string in the buffer, stripping leading and trailing
    435  *	blanks and <>.
    436  */
    437 void
    438 getfrom(char *buf)
    439 {
    440 	char *s, *p;
    441 
    442 	if ((s = strchr(buf, '<')) != NULL)
    443 		s++;
    444 	else
    445 		s = buf;
    446 
    447 	for (; *s && isspace((unsigned char)*s); s++)
    448 		continue;
    449 	for (p = s; *p && !isspace((unsigned char)*p); p++)
    450 		continue;
    451 
    452 	if (*--p == '>')
    453 		*p = '\0';
    454 	else
    455 		*++p = '\0';
    456 
    457 	if (junkmail(s))
    458 		exit(0);
    459 
    460 	if (!*from)
    461 		(void)strlcpy(from, s, sizeof(from));
    462 }
    463 
    464 /*
    465  * junkmail --
    466  *	read the header and return if automagic/junk/bulk/list mail
    467  */
    468 static int
    469 junkmail(const char *addr)
    470 {
    471 	static struct ignore {
    472 		const char *name;
    473 		size_t	len;
    474 	} ignore[] = {
    475 #define INIT(a) { a, sizeof(a) - 1 }
    476 		INIT("-request"),
    477 		INIT("postmaster"),
    478 		INIT("uucp"),
    479 		INIT("mailer-daemon"),
    480 		INIT("mailer"),
    481 		INIT("-relay"),
    482 		{NULL, 0 }
    483 	};
    484 	struct ignore *cur;
    485 	size_t len;
    486 	const char *p;
    487 
    488 	/*
    489 	 * This is mildly amusing, and I'm not positive it's right; trying
    490 	 * to find the "real" name of the sender, assuming that addresses
    491 	 * will be some variant of:
    492 	 *
    493 	 * From site!site!SENDER%site.domain%site.domain (at) site.domain
    494 	 */
    495 	if (!(p = strchr(addr, '%')))
    496 		if (!(p = strchr(addr, '@'))) {
    497 			if ((p = strrchr(addr, '!')) != NULL)
    498 				++p;
    499 			else
    500 				p = addr;
    501 			for (; *p; ++p)
    502 				continue;
    503 		}
    504 	len = p - addr;
    505 	for (cur = ignore; cur->name; ++cur)
    506 		if (len >= cur->len &&
    507 		    !strncasecmp(cur->name, p - cur->len, cur->len))
    508 			return(1);
    509 	return(0);
    510 }
    511 
    512 #define	VIT	"__VACATION__INTERVAL__TIMER__"
    513 
    514 /*
    515  * recent --
    516  *	find out if user has gotten a vacation message recently.
    517  *	use memmove for machines with alignment restrictions
    518  */
    519 static int
    520 recent(void)
    521 {
    522 	DBT key, data;
    523 	time_t then, next;
    524 
    525 	/* get interval time */
    526 	key.data = (void *)(intptr_t)VIT;
    527 	key.size = sizeof(VIT);
    528 	if ((db->get)(db, &key, &data, 0))
    529 		next = SECSPERDAY * DAYSPERWEEK;
    530 	else
    531 		(void)memmove(&next, data.data, sizeof(next));
    532 
    533 	/* get record for this address */
    534 	key.data = from;
    535 	key.size = strlen(from);
    536 	if (!(db->get)(db, &key, &data, 0)) {
    537 		(void)memmove(&then, data.data, sizeof(then));
    538 		if (next == (time_t)LONG_MAX ||			/* XXX */
    539 		    then + next > time(NULL))
    540 			return(1);
    541 	}
    542 	return(0);
    543 }
    544 
    545 /*
    546  * setinterval --
    547  *	store the reply interval
    548  */
    549 static void
    550 setinterval(time_t interval)
    551 {
    552 	DBT key, data;
    553 
    554 	key.data = (void *)(intptr_t)VIT;
    555 	key.size = sizeof(VIT);
    556 	data.data = &interval;
    557 	data.size = sizeof(interval);
    558 	(void)(db->put)(db, &key, &data, 0);
    559 }
    560 
    561 /*
    562  * setreply --
    563  *	store that this user knows about the vacation.
    564  */
    565 static void
    566 setreply(void)
    567 {
    568 	DBT key, data;
    569 	time_t now;
    570 
    571 	key.data = from;
    572 	key.size = strlen(from);
    573 	(void)time(&now);
    574 	data.data = &now;
    575 	data.size = sizeof(now);
    576 	(void)(db->put)(db, &key, &data, 0);
    577 }
    578 
    579 /*
    580  * sendmessage --
    581  *	exec sendmail to send the vacation file to sender
    582  */
    583 static void
    584 sendmessage(const char *myname)
    585 {
    586 	FILE *mfp, *sfp;
    587 	int i;
    588 	int pvect[2];
    589 	char buf[MAXLINE];
    590 
    591 	mfp = fopen(msgfile, "r");
    592 	if (mfp == NULL) {
    593 		syslog(LOG_ERR, "%s: no `%s' file for `%s'.", getprogname(),
    594 		    myname, msgfile);
    595 		exit(1);
    596 	}
    597 
    598 	if (debug) {
    599 		sfp = stdout;
    600 	} else {
    601 		if (pipe(pvect) < 0) {
    602 			syslog(LOG_ERR, "%s: pipe: %m", getprogname());
    603 			exit(1);
    604 		}
    605 		i = vfork();
    606 		if (i < 0) {
    607 			syslog(LOG_ERR, "%s: fork: %m", getprogname());
    608 			exit(1);
    609 		}
    610 		if (i == 0) {
    611 			(void)dup2(pvect[0], 0);
    612 			(void)close(pvect[0]);
    613 			(void)close(pvect[1]);
    614 			(void)close(fileno(mfp));
    615 			(void)execl(_PATH_SENDMAIL, "sendmail", "-f", myname,
    616 			    "--", from, NULL);
    617 			syslog(LOG_ERR, "%s: can't exec %s: %m",
    618 			    getprogname(), _PATH_SENDMAIL);
    619 			_exit(1);
    620 		}
    621 		(void)close(pvect[0]);
    622 		sfp = fdopen(pvect[1], "w");
    623 		if (sfp == NULL) {
    624 			syslog(LOG_ERR, "%s: can't fdopen %d: %m",
    625 			    getprogname(), pvect[1]);
    626 			_exit(1);
    627 		}
    628 	}
    629 	(void)fprintf(sfp, "To: %s\n", from);
    630 	(void)fputs("Auto-Submitted: auto-replied\n", sfp);
    631 	while (fgets(buf, sizeof buf, mfp) != NULL) {
    632 		char *p;
    633 		if ((p = strstr(buf, "$SUBJECT")) != NULL) {
    634 			*p = '\0';
    635 			(void)fputs(buf, sfp);
    636 			(void)fputs(subject, sfp);
    637 			p += sizeof("$SUBJECT") - 1;
    638 			(void)fputs(p, sfp);
    639 		} else
    640 		    (void)fputs(buf, sfp);
    641 	}
    642 	(void)fclose(mfp);
    643 	if (sfp != stdout)
    644 		(void)fclose(sfp);
    645 }
    646 
    647 static void
    648 usage(void)
    649 {
    650 
    651 	syslog(LOG_ERR, "uid %u: Usage: %s [-dIij] [-a alias] [-f database_file] [-F F|R|S] [-m message_file] [-s sender] [-t interval] [-T A|D]"
    652 	    " login", getuid(), getprogname());
    653 	exit(1);
    654 }
    655