xref: /csrg-svn/usr.sbin/sendmail/src/alias.c (revision 22903)
122694Sdist /*
222694Sdist **  Sendmail
322694Sdist **  Copyright (c) 1983  Eric P. Allman
422694Sdist **  Berkeley, California
522694Sdist **
622694Sdist **  Copyright (c) 1983 Regents of the University of California.
722694Sdist **  All rights reserved.  The Berkeley software License Agreement
822694Sdist **  specifies the terms and conditions for redistribution.
922694Sdist */
1022694Sdist 
1122694Sdist #ifndef lint
12*22903Smiriam # ifdef DBM
13*22903Smiriam static char	SccsId[] = "@(#)alias.c	5.2 (Berkeley) 06/07/85	(with DBM)";
14*22903Smiriam # else DBM
15*22903Smiriam static char	SccsId[] = "@(#)alias.c	5.2 (Berkeley) 06/07/85	(without DBM)";
16*22903Smiriam # endif DBM
1722694Sdist #endif not lint
1822694Sdist 
19292Seric # include <pwd.h>
204212Seric # include <sys/types.h>
214212Seric # include <sys/stat.h>
228437Seric # include <signal.h>
2319784Seric # include <errno.h>
243309Seric # include "sendmail.h"
2519784Seric # ifdef FLOCK
2619784Seric # include <sys/file.h>
2719784Seric # endif FLOCK
28292Seric 
29402Seric 
30292Seric /*
31292Seric **  ALIAS -- Compute aliases.
32292Seric **
339368Seric **	Scans the alias file for an alias for the given address.
349368Seric **	If found, it arranges to deliver to the alias list instead.
359368Seric **	Uses libdbm database if -DDBM.
36292Seric **
37292Seric **	Parameters:
384097Seric **		a -- address to alias.
394999Seric **		sendq -- a pointer to the head of the send queue
404999Seric **			to put the aliases in.
41292Seric **
42292Seric **	Returns:
43292Seric **		none
44292Seric **
45292Seric **	Side Effects:
463185Seric **		Aliases found are expanded.
47292Seric **
48292Seric **	Notes:
49292Seric **		If NoAlias (the "-n" flag) is set, no aliasing is
50292Seric **			done.
51292Seric **
52292Seric **	Deficiencies:
53292Seric **		It should complain about names that are aliased to
54292Seric **			nothing.
55292Seric */
56292Seric 
57292Seric 
581503Smark #ifdef DBM
592966Seric typedef struct
602966Seric {
612966Seric 	char	*dptr;
624157Seric 	int	dsize;
634157Seric } DATUM;
644157Seric extern DATUM fetch();
651503Smark #endif DBM
66292Seric 
674999Seric alias(a, sendq)
684097Seric 	register ADDRESS *a;
694999Seric 	ADDRESS **sendq;
70292Seric {
714081Seric 	register char *p;
725701Seric 	extern char *aliaslookup();
73292Seric 
74292Seric 	if (NoAlias)
75292Seric 		return;
76292Seric # ifdef DEBUG
777671Seric 	if (tTd(27, 1))
784098Seric 		printf("alias(%s)\n", a->q_paddr);
79292Seric # endif
80292Seric 
814098Seric 	/* don't realias already aliased names */
824098Seric 	if (bitset(QDONTSEND, a->q_flags))
834098Seric 		return;
844098Seric 
856898Seric 	CurEnv->e_to = a->q_paddr;
864098Seric 
874314Seric 	/*
884314Seric 	**  Look up this name
894314Seric 	*/
904314Seric 
915701Seric 	p = aliaslookup(a->q_user);
924098Seric 	if (p == NULL)
934098Seric 		return;
94292Seric 
95292Seric 	/*
964098Seric 	**  Match on Alias.
974098Seric 	**	Deliver to the target list.
981515Seric 	*/
991515Seric 
1004098Seric # ifdef DEBUG
1017671Seric 	if (tTd(27, 1))
1024098Seric 		printf("%s (%s, %s) aliased to %s\n",
1034098Seric 		    a->q_paddr, a->q_host, a->q_user, p);
1044098Seric # endif
1057051Seric 	message(Arpa_Info, "aliased to %s", p);
1064098Seric 	AliasLevel++;
1079614Seric 	sendtolist(p, a, sendq);
1084098Seric 	AliasLevel--;
1094098Seric }
1104098Seric /*
1115701Seric **  ALIASLOOKUP -- look up a name in the alias file.
1125701Seric **
1135701Seric **	Parameters:
1145701Seric **		name -- the name to look up.
1155701Seric **
1165701Seric **	Returns:
1175701Seric **		the value of name.
1185701Seric **		NULL if unknown.
1195701Seric **
1205701Seric **	Side Effects:
1215701Seric **		none.
1225701Seric **
1235701Seric **	Warnings:
1245701Seric **		The return value will be trashed across calls.
1255701Seric */
1265701Seric 
1275701Seric char *
1285701Seric aliaslookup(name)
1295701Seric 	char *name;
1305701Seric {
1315701Seric # ifdef DBM
1325701Seric 	DATUM rhs, lhs;
1335701Seric 
1345701Seric 	/* create a key for fetch */
1355701Seric 	lhs.dptr = name;
1365701Seric 	lhs.dsize = strlen(name) + 1;
1375701Seric 	rhs = fetch(lhs);
1385701Seric 	return (rhs.dptr);
1395701Seric # else DBM
1405701Seric 	register STAB *s;
1415701Seric 
1425701Seric 	s = stab(name, ST_ALIAS, ST_FIND);
1435701Seric 	if (s == NULL)
1445701Seric 		return (NULL);
1455701Seric 	return (s->s_alias);
1465701Seric # endif DBM
1475701Seric }
1485701Seric /*
1494098Seric **  INITALIASES -- initialize for aliasing
1504098Seric **
1514098Seric **	Very different depending on whether we are running DBM or not.
1524098Seric **
1534098Seric **	Parameters:
1544098Seric **		aliasfile -- location of aliases.
1554157Seric **		init -- if set and if DBM, initialize the DBM files.
1564098Seric **
1574098Seric **	Returns:
1584098Seric **		none.
1594098Seric **
1604098Seric **	Side Effects:
1614098Seric **		initializes aliases:
1624098Seric **		if DBM:  opens the database.
1634098Seric **		if ~DBM: reads the aliases into the symbol table.
1644098Seric */
1654098Seric 
1664157Seric # define DBMMODE	0666
1674157Seric 
1684157Seric initaliases(aliasfile, init)
1694098Seric 	char *aliasfile;
1704157Seric 	bool init;
1714098Seric {
1729368Seric #ifdef DBM
1738437Seric 	int atcnt;
1744322Seric 	char buf[MAXNAME];
1754322Seric 	time_t modtime;
1769368Seric #endif DBM
1779368Seric 	struct stat stb;
1784322Seric 
17917984Seric 	if (aliasfile == NULL || stat(aliasfile, &stb) < 0)
1808437Seric 	{
1818437Seric 		NoAlias = TRUE;
18211937Seric 		errno = 0;
1838437Seric 		return;
1848437Seric 	}
1858437Seric 
1868928Seric # ifdef DBM
1874322Seric 	/*
1888437Seric 	**  Check to see that the alias file is complete.
1898437Seric 	**	If not, we will assume that someone died, and it is up
1908437Seric 	**	to us to rebuild it.
1918437Seric 	*/
1928437Seric 
1938437Seric 	dbminit(aliasfile);
19417471Seric 	atcnt = SafeAlias * 2;
19517471Seric 	if (atcnt > 0)
19617471Seric 	{
19717471Seric 		while (!init && atcnt-- >= 0 && aliaslookup("@") == NULL)
19817471Seric 			sleep(30);
19917471Seric 	}
20017471Seric 	else
20117471Seric 		atcnt = 1;
2028437Seric 
2038437Seric 	/*
2044322Seric 	**  See if the DBM version of the file is out of date with
2054322Seric 	**  the text version.  If so, go into 'init' mode automatically.
2064322Seric 	**	This only happens if our effective userid owns the DBM
2074325Seric 	**	version or if the mode of the database is 666 -- this
2084322Seric 	**	is an attempt to avoid protection problems.  Note the
2094322Seric 	**	unpalatable hack to see if the stat succeeded.
2104322Seric 	*/
2114322Seric 
2124322Seric 	modtime = stb.st_mtime;
2134322Seric 	(void) strcpy(buf, aliasfile);
2144322Seric 	(void) strcat(buf, ".pag");
2154322Seric 	stb.st_ino = 0;
21619039Seric 	if (!init && (stat(buf, &stb) < 0 || stb.st_mtime < modtime || atcnt < 0))
2174322Seric 	{
21811937Seric 		errno = 0;
2199150Seric 		if (AutoRebuild && stb.st_ino != 0 &&
2209368Seric 		    ((stb.st_mode & 0777) == 0666 || stb.st_uid == geteuid()))
2214322Seric 		{
2224322Seric 			init = TRUE;
2237051Seric 			message(Arpa_Info, "rebuilding alias database");
2244322Seric 		}
2254322Seric 		else
2264322Seric 		{
22719039Seric #ifdef LOG
22819039Seric 			syslog(LOG_INFO, "alias database out of date");
22919039Seric #endif LOG
2304322Seric 			message(Arpa_Info, "Warning: alias database out of date");
2314322Seric 		}
2324322Seric 	}
2334322Seric 
2344322Seric 
2354322Seric 	/*
2368437Seric 	**  If necessary, load the DBM file.
2374322Seric 	**	If running without DBM, load the symbol table.
2384322Seric 	*/
2394322Seric 
2404157Seric 	if (init)
2418437Seric 	{
2424157Seric 		readaliases(aliasfile, TRUE);
2438437Seric 	}
2444098Seric # else DBM
2454157Seric 	readaliases(aliasfile, init);
2464157Seric # endif DBM
2474157Seric }
2484157Seric /*
2494157Seric **  READALIASES -- read and process the alias file.
2504157Seric **
2514157Seric **	This routine implements the part of initaliases that occurs
2524157Seric **	when we are not going to use the DBM stuff.
2534157Seric **
2544157Seric **	Parameters:
2554157Seric **		aliasfile -- the pathname of the alias file master.
2564157Seric **		init -- if set, initialize the DBM stuff.
2574157Seric **
2584157Seric **	Returns:
2594157Seric **		none.
2604157Seric **
2614157Seric **	Side Effects:
2624157Seric **		Reads aliasfile into the symbol table.
2634157Seric **		Optionally, builds the .dir & .pag files.
2644157Seric */
2654157Seric 
2664157Seric static
2674157Seric readaliases(aliasfile, init)
2684157Seric 	char *aliasfile;
2694157Seric 	bool init;
2704157Seric {
2714098Seric 	register char *p;
2724098Seric 	char *p2;
2734098Seric 	char *rhs;
2744098Seric 	bool skipping;
2759368Seric 	int naliases, bytes, longest;
2769368Seric 	FILE *af;
27719784Seric 	int (*oldsigint)();
2784098Seric 	ADDRESS al, bl;
2794106Seric 	register STAB *s;
2809368Seric 	char line[BUFSIZ];
2814098Seric 
2824098Seric 	if ((af = fopen(aliasfile, "r")) == NULL)
2831515Seric 	{
2844098Seric # ifdef DEBUG
2857671Seric 		if (tTd(27, 1))
2864106Seric 			printf("Can't open %s\n", aliasfile);
2874098Seric # endif
2884098Seric 		errno = 0;
2894098Seric 		NoAlias++;
2904098Seric 		return;
2914098Seric 	}
2924314Seric 
29319784Seric # ifdef DBM
29419784Seric # ifdef FLOCK
29519784Seric 	/* see if someone else is rebuilding the alias file already */
29619784Seric 	if (flock(fileno(af), LOCK_EX | LOCK_NB) < 0 && errno == EWOULDBLOCK)
29719784Seric 	{
29819784Seric 		/* yes, they are -- wait until done and then return */
29919784Seric 		message(Arpa_Info, "Alias file is already being rebuilt");
30019784Seric 		if (OpMode != MD_INITALIAS)
30119784Seric 		{
30219784Seric 			/* wait for other rebuild to complete */
30319784Seric 			(void) flock(fileno(af), LOCK_EX);
30419784Seric 		}
30519784Seric 		fclose(af);
30619784Seric 		errno = 0;
30719784Seric 		return;
30819784Seric 	}
30919784Seric # endif FLOCK
31019784Seric # endif DBM
31119784Seric 
3124314Seric 	/*
31319784Seric 	**  If initializing, create the new DBM files.
31419784Seric 	*/
31519784Seric 
31619784Seric 	if (init)
31719784Seric 	{
31819784Seric 		oldsigint = signal(SIGINT, SIG_IGN);
31919784Seric 		(void) strcpy(line, aliasfile);
32019784Seric 		(void) strcat(line, ".dir");
32119784Seric 		if (close(creat(line, DBMMODE)) < 0)
32219784Seric 		{
32319784Seric 			syserr("cannot make %s", line);
32419784Seric 			(void) signal(SIGINT, oldsigint);
32519784Seric 			return;
32619784Seric 		}
32719784Seric 		(void) strcpy(line, aliasfile);
32819784Seric 		(void) strcat(line, ".pag");
32919784Seric 		if (close(creat(line, DBMMODE)) < 0)
33019784Seric 		{
33119784Seric 			syserr("cannot make %s", line);
33219784Seric 			(void) signal(SIGINT, oldsigint);
33319784Seric 			return;
33419784Seric 		}
33519784Seric 	}
33619784Seric 
33719784Seric 	/*
3384314Seric 	**  Read and interpret lines
3394314Seric 	*/
3404314Seric 
3419368Seric 	FileName = aliasfile;
3429368Seric 	LineNumber = 0;
3434322Seric 	naliases = bytes = longest = 0;
3444098Seric 	skipping = FALSE;
3454098Seric 	while (fgets(line, sizeof (line), af) != NULL)
3464098Seric 	{
3474322Seric 		int lhssize, rhssize;
3484322Seric 
3499368Seric 		LineNumber++;
3504098Seric 		switch (line[0])
3514098Seric 		{
3524098Seric 		  case '#':
3534098Seric 		  case '\n':
3544098Seric 		  case '\0':
3554098Seric 			skipping = FALSE;
3564098Seric 			continue;
3574065Seric 
3584098Seric 		  case ' ':
3594098Seric 		  case '\t':
3604098Seric 			if (!skipping)
3619368Seric 				syserr("Non-continuation line starts with space");
3624098Seric 			skipping = TRUE;
3634097Seric 			continue;
3644098Seric 		}
3654098Seric 		skipping = FALSE;
3661874Seric 
3674314Seric 		/*
3684314Seric 		**  Process the LHS
3694314Seric 		**	Find the final colon, and parse the address.
37016898Seric 		**	It should resolve to a local name -- this will
37116898Seric 		**	be checked later (we want to optionally do
37216898Seric 		**	parsing of the RHS first to maximize error
37316898Seric 		**	detection).
3744314Seric 		*/
3754314Seric 
3764098Seric 		for (p = line; *p != '\0' && *p != ':' && *p != '\n'; p++)
3774097Seric 			continue;
37816898Seric 		if (*p++ != ':')
3794098Seric 		{
3809368Seric 			syserr("missing colon");
3814097Seric 			continue;
3824098Seric 		}
38316898Seric 		if (parseaddr(line, &al, 1, ':') == NULL)
3844098Seric 		{
38516898Seric 			syserr("illegal alias name");
38616898Seric 			continue;
3874098Seric 		}
38816898Seric 		loweraddr(&al);
3894314Seric 
3904314Seric 		/*
3914314Seric 		**  Process the RHS.
3924314Seric 		**	'al' is the internal form of the LHS address.
3934314Seric 		**	'p' points to the text of the RHS.
3944314Seric 		*/
3954314Seric 
3964098Seric 		rhs = p;
3974098Seric 		for (;;)
3984098Seric 		{
3994098Seric 			register char c;
4001515Seric 
4014157Seric 			if (init)
4024098Seric 			{
4034157Seric 				/* do parsing & compression of addresses */
4044098Seric 				c = *p;
4054157Seric 				while (c != '\0')
4064098Seric 				{
4074157Seric 					p2 = p;
4084157Seric 					while (*p != '\n' && *p != ',' && *p != '\0')
4094157Seric 						p++;
4104157Seric 					c = *p;
4114322Seric 					if (c == '\n')
4124322Seric 						c = '\0';
41317199Seric 					*p = '\0';
41417199Seric 					if (*p2 != '\0')
41517199Seric 						(void) parseaddr(p2, &bl, -1, ',');
41617199Seric 					if (c != '\0')
41717199Seric 						*p++ = c;
4184098Seric 				}
4194098Seric 			}
4204157Seric 			else
42115769Seric 			{
42216898Seric 				p = &p[strlen(p)];
42316898Seric 				if (p[-1] == '\n')
42416898Seric 					*--p = '\0';
42515769Seric 			}
4261515Seric 
4274098Seric 			/* see if there should be a continuation line */
4284106Seric 			c = fgetc(af);
4294106Seric 			if (!feof(af))
4304314Seric 				(void) ungetc(c, af);
4314106Seric 			if (c != ' ' && c != '\t')
4324098Seric 				break;
4334098Seric 
4344098Seric 			/* read continuation line */
4354098Seric 			if (fgets(p, sizeof line - (p - line), af) == NULL)
4364098Seric 				break;
4379368Seric 			LineNumber++;
4384098Seric 		}
43916898Seric 		if (al.q_mailer != LocalMailer)
44016898Seric 		{
44116898Seric 			syserr("cannot alias non-local names");
44216898Seric 			continue;
44316898Seric 		}
4444314Seric 
4454314Seric 		/*
4464314Seric 		**  Insert alias into symbol table or DBM file
4474314Seric 		*/
4484314Seric 
44916898Seric 		lhssize = strlen(al.q_user) + 1;
4504322Seric 		rhssize = strlen(rhs) + 1;
4514322Seric 
4524157Seric # ifdef DBM
4534157Seric 		if (init)
4544157Seric 		{
4554157Seric 			DATUM key, content;
4564157Seric 
4574322Seric 			key.dsize = lhssize;
4584157Seric 			key.dptr = al.q_user;
4594322Seric 			content.dsize = rhssize;
4604157Seric 			content.dptr = rhs;
4614157Seric 			store(key, content);
4624157Seric 		}
4634157Seric 		else
4644157Seric # endif DBM
4654157Seric 		{
4664157Seric 			s = stab(al.q_user, ST_ALIAS, ST_ENTER);
4674157Seric 			s->s_alias = newstr(rhs);
4684157Seric 		}
4694322Seric 
4704322Seric 		/* statistics */
4714322Seric 		naliases++;
4724322Seric 		bytes += lhssize + rhssize;
4734322Seric 		if (rhssize > longest)
4744322Seric 			longest = rhssize;
4751515Seric 	}
47619784Seric 
47719784Seric # ifdef DBM
47819784Seric 	if (init)
47919784Seric 	{
48019784Seric 		/* add the distinquished alias "@" */
48119784Seric 		DATUM key;
48219784Seric 
48319784Seric 		key.dsize = 2;
48419784Seric 		key.dptr = "@";
48519784Seric 		store(key, key);
48619784Seric 
48719784Seric 		/* restore the old signal */
48819784Seric 		(void) signal(SIGINT, oldsigint);
48919784Seric 	}
49019784Seric # endif DBM
49119784Seric 
49219784Seric 	/* closing the alias file drops the lock */
4934098Seric 	(void) fclose(af);
4946898Seric 	CurEnv->e_to = NULL;
4959368Seric 	FileName = NULL;
4967051Seric 	message(Arpa_Info, "%d aliases, longest %d bytes, %d bytes total",
4974322Seric 			naliases, longest, bytes);
498292Seric }
499292Seric /*
500292Seric **  FORWARD -- Try to forward mail
501292Seric **
502292Seric **	This is similar but not identical to aliasing.
503292Seric **
504292Seric **	Parameters:
5054314Seric **		user -- the name of the user who's mail we would like
5064314Seric **			to forward to.  It must have been verified --
5074314Seric **			i.e., the q_home field must have been filled
5084314Seric **			in.
5094999Seric **		sendq -- a pointer to the head of the send queue to
5104999Seric **			put this user's aliases in.
511292Seric **
512292Seric **	Returns:
5134098Seric **		none.
514292Seric **
515292Seric **	Side Effects:
5163185Seric **		New names are added to send queues.
517292Seric */
518292Seric 
5194999Seric forward(user, sendq)
5202966Seric 	ADDRESS *user;
5214999Seric 	ADDRESS **sendq;
522292Seric {
5234078Seric 	char buf[60];
5244536Seric 	extern bool safefile();
5254069Seric 
5264098Seric # ifdef DEBUG
5277671Seric 	if (tTd(27, 1))
5284098Seric 		printf("forward(%s)\n", user->q_paddr);
5294098Seric # endif DEBUG
5304098Seric 
5314594Seric 	if (user->q_mailer != LocalMailer || bitset(QBADADDR, user->q_flags))
5324098Seric 		return;
5334314Seric # ifdef DEBUG
5344314Seric 	if (user->q_home == NULL)
5354314Seric 		syserr("forward: no home");
5364314Seric # endif DEBUG
5374069Seric 
5384069Seric 	/* good address -- look for .forward file in home */
5399368Seric 	define('z', user->q_home, CurEnv);
54016154Seric 	expand("\001z/.forward", buf, &buf[sizeof buf - 1], CurEnv);
5414536Seric 	if (!safefile(buf, user->q_uid, S_IREAD))
5424098Seric 		return;
5434069Seric 
5444069Seric 	/* we do have an address to forward to -- do it */
5454999Seric 	include(buf, "forwarding", user, sendq);
546292Seric }
547