xref: /original-bsd/usr.sbin/sendmail/src/alias.c (revision a1c2194a)
1 /*
2  * Copyright (c) 1983 Eric P. Allman
3  * Copyright (c) 1988 Regents of the University of California.
4  * All rights reserved.
5  *
6  * %sccs.include.redist.c%
7  */
8 
9 # include <sys/types.h>
10 # include <sys/stat.h>
11 # include <signal.h>
12 # include <errno.h>
13 # include "sendmail.h"
14 # include <sys/file.h>
15 # include <pwd.h>
16 
17 # ifdef NEWDB
18 # include <db.h>
19 # endif
20 
21 #ifndef lint
22 #ifdef DBM
23 static char sccsid[] = "@(#)alias.c	5.25 (Berkeley) 07/26/91 (with DBM)";
24 #else
25 #ifdef NEWDB
26 static char sccsid[] = "@(#)alias.c	5.25 (Berkeley) 07/26/91 (with NEWDB)";
27 #else
28 static char sccsid[] = "@(#)alias.c	5.25 (Berkeley) 07/26/91 (without DBM)";
29 #endif
30 #endif
31 #endif /* not lint */
32 
33 # ifdef DBM
34 # ifdef NEWDB
35   ERROR ERROR ERROR: must choose one of DBM or NEWDB compilation flags
36 # endif
37 # endif
38 
39 /*
40 **  ALIAS -- Compute aliases.
41 **
42 **	Scans the alias file for an alias for the given address.
43 **	If found, it arranges to deliver to the alias list instead.
44 **	Uses libdbm database if -DDBM.
45 **
46 **	Parameters:
47 **		a -- address to alias.
48 **		sendq -- a pointer to the head of the send queue
49 **			to put the aliases in.
50 **
51 **	Returns:
52 **		none
53 **
54 **	Side Effects:
55 **		Aliases found are expanded.
56 **
57 **	Notes:
58 **		If NoAlias (the "-n" flag) is set, no aliasing is
59 **			done.
60 **
61 **	Deficiencies:
62 **		It should complain about names that are aliased to
63 **			nothing.
64 */
65 
66 
67 #ifdef DBM
68 typedef struct
69 {
70 	char	*data;
71 	int	size;
72 } DBT;
73 extern DBT fetch();
74 #endif /* DBM */
75 
76 #ifdef NEWDB
77 static DB	*AliasDBptr;
78 #endif
79 
80 alias(a, sendq)
81 	register ADDRESS *a;
82 	ADDRESS **sendq;
83 {
84 	register char *p;
85 	extern char *aliaslookup();
86 
87 	if (tTd(27, 1))
88 		printf("alias(%s)\n", a->q_paddr);
89 
90 	/* don't realias already aliased names */
91 	if (bitset(QDONTSEND, a->q_flags))
92 		return;
93 
94 	CurEnv->e_to = a->q_paddr;
95 
96 	/*
97 	**  Look up this name
98 	*/
99 
100 	if (NoAlias)
101 		p = NULL;
102 	else
103 		p = aliaslookup(a->q_user);
104 	if (p == NULL)
105 		return;
106 
107 	/*
108 	**  Match on Alias.
109 	**	Deliver to the target list.
110 	*/
111 
112 	if (tTd(27, 1))
113 		printf("%s (%s, %s) aliased to %s\n",
114 		    a->q_paddr, a->q_host, a->q_user, p);
115 	message(Arpa_Info, "aliased to %s", p);
116 	AliasLevel++;
117 	sendtolist(p, a, sendq);
118 	AliasLevel--;
119 }
120 /*
121 **  ALIASLOOKUP -- look up a name in the alias file.
122 **
123 **	Parameters:
124 **		name -- the name to look up.
125 **
126 **	Returns:
127 **		the value of name.
128 **		NULL if unknown.
129 **
130 **	Side Effects:
131 **		none.
132 **
133 **	Warnings:
134 **		The return value will be trashed across calls.
135 */
136 
137 char *
138 aliaslookup(name)
139 	char *name;
140 {
141 # if defined(NEWDB) || defined(DBM)
142 	DBT rhs, lhs;
143 	int s;
144 
145 	/* create a key for fetch */
146 	lhs.data = name;
147 	lhs.size = strlen(name) + 1;
148 # ifdef NEWDB
149 	s = AliasDBptr->get(AliasDBptr, &lhs, &rhs, 0);
150 	if (s != 0)
151 		return (NULL);
152 # else
153 	rhs = fetch(lhs);
154 # endif
155 	return (rhs.data);
156 # else DBM
157 	register STAB *s;
158 
159 	s = stab(name, ST_ALIAS, ST_FIND);
160 	if (s == NULL)
161 		return (NULL);
162 	return (s->s_alias);
163 # endif DBM
164 }
165 /*
166 **  INITALIASES -- initialize for aliasing
167 **
168 **	Very different depending on whether we are running DBM or not.
169 **
170 **	Parameters:
171 **		aliasfile -- location of aliases.
172 **		init -- if set and if DBM, initialize the DBM files.
173 **
174 **	Returns:
175 **		none.
176 **
177 **	Side Effects:
178 **		initializes aliases:
179 **		if DBM:  opens the database.
180 **		if ~DBM: reads the aliases into the symbol table.
181 */
182 
183 # define DBMMODE	0644
184 
185 initaliases(aliasfile, init)
186 	char *aliasfile;
187 	bool init;
188 {
189 #if defined(DBM) || defined(NEWDB)
190 	int atcnt;
191 	time_t modtime;
192 	bool automatic = FALSE;
193 	char buf[MAXNAME];
194 #endif
195 	struct stat stb;
196 	static bool initialized = FALSE;
197 	static int readaliases();
198 
199 	if (initialized)
200 		return;
201 	initialized = TRUE;
202 
203 	if (aliasfile == NULL || stat(aliasfile, &stb) < 0)
204 	{
205 		if (aliasfile != NULL && init)
206 			syserr("Cannot open %s", aliasfile);
207 		NoAlias = TRUE;
208 		errno = 0;
209 		return;
210 	}
211 
212 # if defined(DBM) || defined(NEWDB)
213 	/*
214 	**  Check to see that the alias file is complete.
215 	**	If not, we will assume that someone died, and it is up
216 	**	to us to rebuild it.
217 	*/
218 
219 	if (!init)
220 	{
221 # ifdef NEWDB
222 		(void) strcpy(buf, aliasfile);
223 		(void) strcat(buf, ".db");
224 		AliasDBptr = hash_open(buf, O_RDONLY, DBMMODE, NULL);
225 		if (AliasDBptr == NULL)
226 		{
227 			syserr("initaliases: cannot open %s", buf);
228 			NoAlias = TRUE;
229 			return;
230 		}
231 # else
232 		dbminit(aliasfile);
233 # endif
234 	}
235 	atcnt = SafeAlias * 2;
236 	if (atcnt > 0)
237 	{
238 		while (!init && atcnt-- >= 0 && aliaslookup("@") == NULL)
239 		{
240 			/*
241 			**  Reinitialize alias file in case the new
242 			**  one is mv'ed in instead of cp'ed in.
243 			**
244 			**	Only works with new DBM -- old one will
245 			**	just consume file descriptors forever.
246 			**	If you have a dbmclose() it can be
247 			**	added before the sleep(30).
248 			*/
249 
250 # ifdef NEWDB
251 			AliasDBptr->close(AliasDBptr);
252 # endif
253 
254 			sleep(30);
255 # ifdef NEWDB
256 			(void) strcpy(buf, aliasfile);
257 			(void) strcat(buf, ".db");
258 			AliasDBptr = hash_open(buf, O_RDONLY, DBMMODE, NULL);
259 			if (AliasDBptr == NULL)
260 			{
261 				syserr("initaliases: cannot open %s", buf);
262 				NoAlias = TRUE;
263 				return;
264 			}
265 # else
266 # ifdef NDBM
267 			dbminit(aliasfile);
268 # endif
269 # endif
270 		}
271 	}
272 	else
273 		atcnt = 1;
274 
275 	/*
276 	**  See if the DBM version of the file is out of date with
277 	**  the text version.  If so, go into 'init' mode automatically.
278 	**	This only happens if our effective userid owns the DBM.
279 	**	Note the unpalatable hack to see if the stat succeeded.
280 	*/
281 
282 	modtime = stb.st_mtime;
283 	(void) strcpy(buf, aliasfile);
284 # ifdef NEWDB
285 	(void) strcat(buf, ".db");
286 # else
287 	(void) strcat(buf, ".pag");
288 # endif
289 	stb.st_ino = 0;
290 	if (!init && (stat(buf, &stb) < 0 || stb.st_mtime < modtime || atcnt < 0))
291 	{
292 		errno = 0;
293 		if (AutoRebuild && stb.st_ino != 0 && stb.st_uid == geteuid())
294 		{
295 			init = TRUE;
296 			automatic = TRUE;
297 			message(Arpa_Info, "rebuilding alias database");
298 #ifdef LOG
299 			if (LogLevel >= 7)
300 				syslog(LOG_INFO, "rebuilding alias database");
301 #endif LOG
302 		}
303 		else
304 		{
305 #ifdef LOG
306 			if (LogLevel >= 7)
307 				syslog(LOG_INFO, "alias database out of date");
308 #endif LOG
309 			message(Arpa_Info, "Warning: alias database out of date");
310 		}
311 	}
312 
313 
314 	/*
315 	**  If necessary, load the DBM file.
316 	**	If running without DBM, load the symbol table.
317 	*/
318 
319 	if (init)
320 	{
321 #ifdef LOG
322 		if (LogLevel >= 6)
323 		{
324 			extern char *username();
325 
326 			syslog(LOG_NOTICE, "alias database %srebuilt by %s",
327 				automatic ? "auto" : "", username());
328 		}
329 #endif LOG
330 		readaliases(aliasfile, TRUE);
331 	}
332 # else DBM
333 	readaliases(aliasfile, init);
334 # endif DBM
335 }
336 /*
337 **  READALIASES -- read and process the alias file.
338 **
339 **	This routine implements the part of initaliases that occurs
340 **	when we are not going to use the DBM stuff.
341 **
342 **	Parameters:
343 **		aliasfile -- the pathname of the alias file master.
344 **		init -- if set, initialize the DBM stuff.
345 **
346 **	Returns:
347 **		none.
348 **
349 **	Side Effects:
350 **		Reads aliasfile into the symbol table.
351 **		Optionally, builds the .dir & .pag files.
352 */
353 
354 static
355 readaliases(aliasfile, init)
356 	char *aliasfile;
357 	bool init;
358 {
359 	register char *p;
360 	char *rhs;
361 	bool skipping;
362 	int naliases, bytes, longest;
363 	FILE *af;
364 	void (*oldsigint)();
365 	ADDRESS al, bl;
366 	register STAB *s;
367 # ifdef NEWDB
368 	DB *dbp;
369 # endif
370 	char line[BUFSIZ];
371 
372 	if ((af = fopen(aliasfile, "r")) == NULL)
373 	{
374 		if (tTd(27, 1))
375 			printf("Can't open %s\n", aliasfile);
376 		errno = 0;
377 		NoAlias++;
378 		return;
379 	}
380 
381 # if defined(DBM) || defined(NEWDB)
382 	/* see if someone else is rebuilding the alias file already */
383 	if (flock(fileno(af), LOCK_EX | LOCK_NB) < 0 && errno == EWOULDBLOCK)
384 	{
385 		/* yes, they are -- wait until done and then return */
386 		message(Arpa_Info, "Alias file is already being rebuilt");
387 		if (OpMode != MD_INITALIAS)
388 		{
389 			/* wait for other rebuild to complete */
390 			(void) flock(fileno(af), LOCK_EX);
391 		}
392 		(void) fclose(af);
393 		errno = 0;
394 		return;
395 	}
396 # endif DBM
397 
398 	/*
399 	**  If initializing, create the new DBM files.
400 	*/
401 
402 	if (init)
403 	{
404 		oldsigint = signal(SIGINT, SIG_IGN);
405 # ifdef DBM
406 		(void) strcpy(line, aliasfile);
407 		(void) strcat(line, ".dir");
408 		if (close(creat(line, DBMMODE)) < 0)
409 		{
410 			syserr("cannot make %s", line);
411 			(void) signal(SIGINT, oldsigint);
412 			return;
413 		}
414 		(void) strcpy(line, aliasfile);
415 		(void) strcat(line, ".pag");
416 		if (close(creat(line, DBMMODE)) < 0)
417 		{
418 			syserr("cannot make %s", line);
419 			(void) signal(SIGINT, oldsigint);
420 			return;
421 		}
422 		dbminit(aliasfile);
423 # endif
424 # ifdef NEWDB
425 		(void) strcpy(line, aliasfile);
426 		(void) strcat(line, ".db");
427 		dbp = hash_open(line, O_RDWR|O_CREAT|O_TRUNC, DBMMODE, NULL);
428 		if (dbp == NULL)
429 		{
430 			syserr("readaliases: cannot create %s", line);
431 			(void) signal(SIGINT, oldsigint);
432 			return;
433 		}
434 # endif
435 	}
436 
437 	/*
438 	**  Read and interpret lines
439 	*/
440 
441 	FileName = aliasfile;
442 	LineNumber = 0;
443 	naliases = bytes = longest = 0;
444 	skipping = FALSE;
445 	while (fgets(line, sizeof (line), af) != NULL)
446 	{
447 		int lhssize, rhssize;
448 
449 		LineNumber++;
450 		p = index(line, '\n');
451 		if (p != NULL)
452 			*p = '\0';
453 		switch (line[0])
454 		{
455 		  case '#':
456 		  case '\0':
457 			skipping = FALSE;
458 			continue;
459 
460 		  case ' ':
461 		  case '\t':
462 			if (!skipping)
463 				syserr("Non-continuation line starts with space");
464 			skipping = TRUE;
465 			continue;
466 		}
467 		skipping = FALSE;
468 
469 		/*
470 		**  Process the LHS
471 		**	Find the final colon, and parse the address.
472 		**	It should resolve to a local name -- this will
473 		**	be checked later (we want to optionally do
474 		**	parsing of the RHS first to maximize error
475 		**	detection).
476 		*/
477 
478 		for (p = line; *p != '\0' && *p != ':' && *p != '\n'; p++)
479 			continue;
480 		if (*p++ != ':')
481 		{
482 			syserr("missing colon");
483 			continue;
484 		}
485 		if (parseaddr(line, &al, 1, ':') == NULL)
486 		{
487 			syserr("illegal alias name");
488 			continue;
489 		}
490 		loweraddr(&al);
491 
492 		/*
493 		**  Process the RHS.
494 		**	'al' is the internal form of the LHS address.
495 		**	'p' points to the text of the RHS.
496 		*/
497 
498 		rhs = p;
499 		for (;;)
500 		{
501 			register char c;
502 
503 			if (init && CheckAliases)
504 			{
505 				/* do parsing & compression of addresses */
506 				while (*p != '\0')
507 				{
508 					extern char *DelimChar;
509 
510 					while (isspace(*p) || *p == ',')
511 						p++;
512 					if (*p == '\0')
513 						break;
514 					if (parseaddr(p, &bl, -1, ',') == NULL)
515 						usrerr("%s... bad address", p);
516 					p = DelimChar;
517 				}
518 			}
519 			else
520 			{
521 				p = &p[strlen(p)];
522 				if (p[-1] == '\n')
523 					*--p = '\0';
524 			}
525 
526 			/* see if there should be a continuation line */
527 			c = fgetc(af);
528 			if (!feof(af))
529 				(void) ungetc(c, af);
530 			if (c != ' ' && c != '\t')
531 				break;
532 
533 			/* read continuation line */
534 			if (fgets(p, sizeof line - (p - line), af) == NULL)
535 				break;
536 			LineNumber++;
537 		}
538 		if (al.q_mailer != LocalMailer)
539 		{
540 			syserr("cannot alias non-local names");
541 			continue;
542 		}
543 
544 		/*
545 		**  Insert alias into symbol table or DBM file
546 		*/
547 
548 		lhssize = strlen(al.q_user) + 1;
549 		rhssize = strlen(rhs) + 1;
550 
551 # if defined(DBM) || defined(NEWDB)
552 		if (init)
553 		{
554 			DBT key, content;
555 
556 			key.size = lhssize;
557 			key.data = al.q_user;
558 			content.size = rhssize;
559 			content.data = rhs;
560 # ifdef DBM
561 			store(key, content);
562 # else
563 			if (dbp->put(dbp, &key, &content, R_PUT) != 0)
564 				syserr("readaliases: db put (%s)", al.q_user);
565 # endif
566 		}
567 		else
568 # endif DBM
569 		{
570 			s = stab(al.q_user, ST_ALIAS, ST_ENTER);
571 			s->s_alias = newstr(rhs);
572 		}
573 
574 		/* statistics */
575 		naliases++;
576 		bytes += lhssize + rhssize;
577 		if (rhssize > longest)
578 			longest = rhssize;
579 	}
580 
581 # if defined(DBM) || defined(NEWDB)
582 	if (init)
583 	{
584 		/* add the distinquished alias "@" */
585 		DBT key;
586 
587 		key.size = 2;
588 		key.data = "@";
589 # ifdef NEWDB
590 		if (dbp->sync(dbp) != 0 ||
591 		    dbp->put(dbp, &key, &key, R_PUT) != 0 ||
592 		    dbp->close(dbp) != 0)
593 			syserr("readaliases: db close failure");
594 # else
595 		store(key, key);
596 # endif
597 
598 		/* restore the old signal */
599 		(void) signal(SIGINT, oldsigint);
600 	}
601 # endif DBM
602 
603 	/* closing the alias file drops the lock */
604 	(void) fclose(af);
605 	CurEnv->e_to = NULL;
606 	FileName = NULL;
607 	message(Arpa_Info, "%d aliases, longest %d bytes, %d bytes total",
608 			naliases, longest, bytes);
609 # ifdef LOG
610 	if (LogLevel >= 8)
611 		syslog(LOG_INFO, "%d aliases, longest %d bytes, %d bytes total",
612 			naliases, longest, bytes);
613 # endif LOG
614 }
615 /*
616 **  FORWARD -- Try to forward mail
617 **
618 **	This is similar but not identical to aliasing.
619 **
620 **	Parameters:
621 **		user -- the name of the user who's mail we would like
622 **			to forward to.  It must have been verified --
623 **			i.e., the q_home field must have been filled
624 **			in.
625 **		sendq -- a pointer to the head of the send queue to
626 **			put this user's aliases in.
627 **
628 **	Returns:
629 **		none.
630 **
631 **	Side Effects:
632 **		New names are added to send queues.
633 */
634 
635 forward(user, sendq)
636 	ADDRESS *user;
637 	ADDRESS **sendq;
638 {
639 	char buf[60];
640 	extern bool safefile();
641 
642 	if (tTd(27, 1))
643 		printf("forward(%s)\n", user->q_paddr);
644 
645 	if (user->q_mailer != LocalMailer || bitset(QBADADDR, user->q_flags))
646 		return;
647 	if (user->q_home == NULL)
648 		syserr("forward: no home");
649 
650 	/* good address -- look for .forward file in home */
651 	define('z', user->q_home, CurEnv);
652 	expand("\001z/.forward", buf, &buf[sizeof buf - 1], CurEnv);
653 	if (!safefile(buf, user->q_uid, S_IREAD))
654 		return;
655 
656 	/* we do have an address to forward to -- do it */
657 	include(buf, "forwarding", user, sendq);
658 }
659