xref: /freebsd/contrib/sendmail/src/udb.c (revision 4543ef516683042d46f3bd3bb8a4f3f746e00499)
1 /*
2  * Copyright (c) 1998-2003, 2006 Proofpoint, Inc. and its suppliers.
3  *	All rights reserved.
4  * Copyright (c) 1983, 1995-1997 Eric P. Allman.  All rights reserved.
5  * Copyright (c) 1988, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * By using this file, you agree to the terms and conditions set
9  * forth in the LICENSE file which can be found at the top level of
10  * the sendmail distribution.
11  *
12  */
13 
14 #include <sendmail.h>
15 #include "map.h"
16 
17 #if USERDB
18 SM_RCSID("@(#)$Id: udb.c,v 8.166 2013-11-22 20:51:57 ca Exp $ (with USERDB)")
19 #else
20 SM_RCSID("@(#)$Id: udb.c,v 8.166 2013-11-22 20:51:57 ca Exp $ (without USERDB)")
21 #endif
22 
23 #if USERDB
24 
25 #include <sm/sendmail.h>
26 # if NEWDB
27 #  include "sm/bdb.h"
28 # else /* NEWDB */
29 #  define DBT	struct _data_base_thang_
30 DBT
31 {
32 	void	*data;		/* pointer to data */
33 	size_t	size;		/* length of data */
34 };
35 # endif /* NEWDB */
36 
37 /*
38 **  UDB.C -- interface between sendmail and Berkeley User Data Base.
39 **
40 **	This depends on the 4.4BSD db package.
41 */
42 
43 struct udbent
44 {
45 	char	*udb_spec;		/* string version of spec */
46 	int	udb_type;		/* type of entry */
47 	pid_t	udb_pid;		/* PID of process which opened db */
48 	char	*udb_default;		/* default host for outgoing mail */
49 	union
50 	{
51 # if NETINET || NETINET6
52 		/* type UE_REMOTE -- do remote call for lookup */
53 		struct
54 		{
55 			SOCKADDR	_udb_addr;	/* address */
56 			int		_udb_timeout;	/* timeout */
57 		} udb_remote;
58 #  define udb_addr	udb_u.udb_remote._udb_addr
59 #  define udb_timeout	udb_u.udb_remote._udb_timeout
60 # endif /* NETINET || NETINET6 */
61 
62 		/* type UE_FORWARD -- forward message to remote */
63 		struct
64 		{
65 			char	*_udb_fwdhost;	/* name of forward host */
66 		} udb_forward;
67 # define udb_fwdhost	udb_u.udb_forward._udb_fwdhost
68 
69 # if NEWDB
70 		/* type UE_FETCH -- look up in local database */
71 		struct
72 		{
73 			char	*_udb_dbname;	/* pathname of database */
74 			DB	*_udb_dbp;	/* open database ptr */
75 		} udb_lookup;
76 #  define udb_dbname	udb_u.udb_lookup._udb_dbname
77 #  define udb_dbp	udb_u.udb_lookup._udb_dbp
78 # endif /* NEWDB */
79 	} udb_u;
80 };
81 
82 # define UDB_EOLIST	0	/* end of list */
83 # define UDB_SKIP	1	/* skip this entry */
84 # define UDB_REMOTE	2	/* look up in remote database */
85 # define UDB_DBFETCH	3	/* look up in local database */
86 # define UDB_FORWARD	4	/* forward to remote host */
87 # define UDB_HESIOD	5	/* look up via hesiod */
88 
89 # define MAXUDBENT	10	/* maximum number of UDB entries */
90 
91 struct udb_option
92 {
93 	char	*udbo_name;
94 	char	*udbo_val;
95 };
96 
97 # if HESIOD
98 static int	hes_udb_get __P((DBT *, DBT *));
99 # endif
100 static char	*udbmatch __P((char *, char *, SM_RPOOL_T *));
101 static int	_udbx_init __P((ENVELOPE *));
102 static int	_udb_parsespec __P((char *, struct udb_option [], int));
103 
104 /*
105 **  UDBEXPAND -- look up user in database and expand
106 **
107 **	Parameters:
108 **		a -- address to expand.
109 **		sendq -- pointer to head of sendq to put the expansions in.
110 **		aliaslevel -- the current alias nesting depth.
111 **		e -- the current envelope.
112 **
113 **	Returns:
114 **		EX_TEMPFAIL -- if something "odd" happened -- probably due
115 **			to accessing a file on an NFS server that is down.
116 **		EX_OK -- otherwise.
117 **
118 **	Side Effects:
119 **		Modifies sendq.
120 */
121 
122 static struct udbent	UdbEnts[MAXUDBENT + 1];
123 static bool		UdbInitialized = false;
124 
125 int
126 udbexpand(a, sendq, aliaslevel, e)
127 	register ADDRESS *a;
128 	ADDRESS **sendq;
129 	int aliaslevel;
130 	register ENVELOPE *e;
131 {
132 	int i;
133 	DBT key;
134 	DBT info;
135 	bool breakout;
136 	register struct udbent *up;
137 	int keylen;
138 	int naddrs;
139 	char *user;
140 	char keybuf[MAXUDBKEY];
141 
142 	memset(&key, '\0', sizeof(key));
143 	memset(&info, '\0', sizeof(info));
144 
145 	if (tTd(28, 1))
146 		sm_dprintf("udbexpand(%s)\n", a->q_paddr);
147 
148 	/* make certain we are supposed to send to this address */
149 	if (!QS_IS_SENDABLE(a->q_state))
150 		return EX_OK;
151 	e->e_to = a->q_paddr;
152 
153 	/* on first call, locate the database */
154 	if (!UdbInitialized)
155 	{
156 		if (_udbx_init(e) == EX_TEMPFAIL)
157 			return EX_TEMPFAIL;
158 	}
159 
160 	/* short circuit the process if no chance of a match */
161 	if (SM_IS_EMPTY(UdbSpec))
162 		return EX_OK;
163 
164 	/* extract user to do userdb matching on */
165 	user = a->q_user;
166 
167 	/* short circuit name begins with '\\' since it can't possibly match */
168 	/* (might want to treat this as unquoted instead) */
169 	if (user[0] == '\\')
170 		return EX_OK;
171 
172 	/* if name begins with a colon, it indicates our metadata */
173 	if (user[0] == ':')
174 		return EX_OK;
175 
176 	keylen = sm_strlcpyn(keybuf, sizeof(keybuf), 2, user, ":maildrop");
177 
178 	/* if name is too long, assume it won't match */
179 	if (keylen >= sizeof(keybuf))
180 		return EX_OK;
181 
182 	/* build actual database key */
183 
184 	breakout = false;
185 	for (up = UdbEnts; !breakout; up++)
186 	{
187 		int usersize;
188 # if NEWDB
189 		int userleft;
190 # endif
191 		char userbuf[MEMCHUNKSIZE];
192 # if HESIOD && HES_GETMAILHOST
193 		char pobuf[MAXNAME];	/* EAI:should be ok, no UTF8? */
194 # endif
195 # if defined(NEWDB) && DB_VERSION_MAJOR > 1
196 		DBC *dbc = NULL;
197 # endif
198 
199 		user = userbuf;
200 		userbuf[0] = '\0';
201 		usersize = sizeof(userbuf);
202 # if NEWDB
203 		userleft = sizeof(userbuf) - 1;
204 # endif
205 
206 		/*
207 		**  Select action based on entry type.
208 		**
209 		**	On dropping out of this switch, "class" should
210 		**	explain the type of the data, and "user" should
211 		**	contain the user information.
212 		*/
213 
214 		switch (up->udb_type)
215 		{
216 # if NEWDB
217 		  case UDB_DBFETCH:
218 			key.data = keybuf;
219 			key.size = keylen;
220 			if (tTd(28, 80))
221 				sm_dprintf("udbexpand: trying %s (%d) via db\n",
222 					keybuf, keylen);
223 #  if DB_VERSION_MAJOR < 2
224 			i = (*up->udb_dbp->seq)(up->udb_dbp, &key, &info, R_CURSOR);
225 #  else /* DB_VERSION_MAJOR < 2 */
226 			i = 0;
227 			if (dbc == NULL &&
228 #   if DB_VERSION_MAJOR > 2 || DB_VERSION_MINOR >= 6
229 			    (errno = (*up->udb_dbp->cursor)(up->udb_dbp,
230 							    NULL, &dbc, 0)) != 0)
231 #   else /* DB_VERSION_MAJOR > 2 || DB_VERSION_MINOR >= 6 */
232 			    (errno = (*up->udb_dbp->cursor)(up->udb_dbp,
233 							    NULL, &dbc)) != 0)
234 #   endif /* DB_VERSION_MAJOR > 2 || DB_VERSION_MINOR >= 6 */
235 				i = -1;
236 			if (i != 0 || dbc == NULL ||
237 			    (errno = dbc->c_get(dbc, &key,
238 						&info, DB_SET)) != 0)
239 				i = 1;
240 #  endif /* DB_VERSION_MAJOR < 2 */
241 			if (i > 0 || info.size <= 0)
242 			{
243 				if (tTd(28, 2))
244 					sm_dprintf("udbexpand: no match on %s (%d)\n",
245 						keybuf, keylen);
246 #  if DB_VERSION_MAJOR > 1
247 				if (dbc != NULL)
248 				{
249 					(void) dbc->c_close(dbc);
250 					dbc = NULL;
251 				}
252 #  endif /* DB_VERSION_MAJOR > 1 */
253 				break;
254 			}
255 			if (tTd(28, 80))
256 				sm_dprintf("udbexpand: match %.*s: %.*s\n",
257 					(int) key.size, (char *) key.data,
258 					(int) info.size, (char *) info.data);
259 
260 			a->q_flags &= ~QSELFREF;
261 			while (i == 0 && key.size == keylen &&
262 			       memcmp(key.data, keybuf, keylen) == 0)
263 			{
264 				char *p;
265 
266 				if (bitset(EF_VRFYONLY, e->e_flags))
267 				{
268 					a->q_state = QS_VERIFIED;
269 #  if DB_VERSION_MAJOR > 1
270 					if (dbc != NULL)
271 					{
272 						(void) dbc->c_close(dbc);
273 						dbc = NULL;
274 					}
275 #  endif /* DB_VERSION_MAJOR > 1 */
276 					return EX_OK;
277 				}
278 
279 				breakout = true;
280 				if (info.size >= userleft - 1)
281 				{
282 					char *nuser;
283 					int size = MEMCHUNKSIZE;
284 
285 					if (info.size > MEMCHUNKSIZE)
286 						size = info.size;
287 					nuser = sm_malloc_x(usersize + size);
288 
289 					memmove(nuser, user, usersize);
290 					if (user != userbuf)
291 						sm_free(user); /* XXX */
292 					user = nuser;
293 					usersize += size;
294 					userleft += size;
295 				}
296 				p = &user[strlen(user)];
297 				if (p != user)
298 				{
299 					*p++ = ',';
300 					userleft--;
301 				}
302 				memmove(p, info.data, info.size);
303 				p[info.size] = '\0';
304 				userleft -= info.size;
305 
306 				/* get the next record */
307 #  if DB_VERSION_MAJOR < 2
308 				i = (*up->udb_dbp->seq)(up->udb_dbp, &key, &info, R_NEXT);
309 #  else /* DB_VERSION_MAJOR < 2 */
310 				i = 0;
311 				if ((errno = dbc->c_get(dbc, &key,
312 							&info, DB_NEXT)) != 0)
313 					i = 1;
314 #  endif /* DB_VERSION_MAJOR < 2 */
315 			}
316 
317 #  if DB_VERSION_MAJOR > 1
318 			if (dbc != NULL)
319 			{
320 				(void) dbc->c_close(dbc);
321 				dbc = NULL;
322 			}
323 #  endif /* DB_VERSION_MAJOR > 1 */
324 
325 			/* if nothing ever matched, try next database */
326 			if (!breakout)
327 				break;
328 
329 			message("expanded to %s", user);
330 			if (LogLevel > 10)
331 				sm_syslog(LOG_INFO, e->e_id,
332 					  "expand %.100s => %s",
333 					  e->e_to,
334 					  shortenstring(user, MAXSHORTSTR));
335 			naddrs = sendtolist(user, a, sendq, aliaslevel + 1, e);
336 			if (naddrs > 0 && !bitset(QSELFREF, a->q_flags))
337 			{
338 				if (tTd(28, 5))
339 				{
340 					sm_dprintf("udbexpand: QS_EXPANDED ");
341 					printaddr(sm_debug_file(), a, false);
342 				}
343 				a->q_state = QS_EXPANDED;
344 			}
345 			if (i < 0)
346 			{
347 				syserr("udbexpand: db-get %.*s stat %d",
348 					(int) key.size, (char *) key.data, i);
349 				return EX_TEMPFAIL;
350 			}
351 
352 			/*
353 			**  If this address has a -request address, reflect
354 			**  it into the envelope.
355 			*/
356 
357 			memset(&key, '\0', sizeof(key));
358 			memset(&info, '\0', sizeof(info));
359 			(void) sm_strlcpyn(keybuf, sizeof(keybuf), 2, a->q_user,
360 					   ":mailsender");
361 			keylen = strlen(keybuf);
362 			key.data = keybuf;
363 			key.size = keylen;
364 
365 #  if DB_VERSION_MAJOR < 2
366 			i = (*up->udb_dbp->get)(up->udb_dbp, &key, &info, 0);
367 #  else
368 			i = errno = (*up->udb_dbp->get)(up->udb_dbp, NULL,
369 							&key, &info, 0);
370 #  endif
371 			if (i != 0 || info.size <= 0)
372 				break;
373 			a->q_owner = sm_rpool_malloc_x(e->e_rpool,
374 						       info.size + 1);
375 			memmove(a->q_owner, info.data, info.size);
376 			a->q_owner[info.size] = '\0';
377 
378 			/* announce delivery; NORECEIPT bit set later */
379 			if (e->e_xfp != NULL)
380 			{
381 				(void) sm_io_fprintf(e->e_xfp, SM_TIME_DEFAULT,
382 						     "Message delivered to mailing list %s\n",
383 						     a->q_paddr);
384 			}
385 			e->e_flags |= EF_SENDRECEIPT;
386 			a->q_flags |= QDELIVERED|QEXPANDED;
387 			break;
388 # endif /* NEWDB */
389 
390 # if HESIOD
391 		  case UDB_HESIOD:
392 			key.data = keybuf;
393 			key.size = keylen;
394 			if (tTd(28, 80))
395 				sm_dprintf("udbexpand: trying %s (%d) via hesiod\n",
396 					keybuf, keylen);
397 			/* look up the key via hesiod */
398 			i = hes_udb_get(&key, &info);
399 			if (i < 0)
400 			{
401 				syserr("udbexpand: hesiod-get %.*s stat %d",
402 					(int) key.size, (char *) key.data, i);
403 				return EX_TEMPFAIL;
404 			}
405 			else if (i > 0 || info.size <= 0)
406 			{
407 #  if HES_GETMAILHOST
408 				struct hes_postoffice *hp;
409 #  endif
410 
411 				if (tTd(28, 2))
412 					sm_dprintf("udbexpand: no match on %s (%d)\n",
413 						(char *) keybuf, (int) keylen);
414 #  if HES_GETMAILHOST
415 				if (tTd(28, 8))
416 					sm_dprintf("  ... trying hes_getmailhost(%s)\n",
417 						a->q_user);
418 				hp = hes_getmailhost(a->q_user);
419 				if (hp == NULL)
420 				{
421 					if (hes_error() == HES_ER_NET)
422 					{
423 						syserr("udbexpand: hesiod-getmail %s stat %d",
424 							a->q_user, hes_error());
425 						return EX_TEMPFAIL;
426 					}
427 					if (tTd(28, 2))
428 						sm_dprintf("hes_getmailhost(%s): %d\n",
429 							a->q_user, hes_error());
430 					break;
431 				}
432 				if (strlen(hp->po_name) + strlen(hp->po_host) >
433 				    sizeof(pobuf) - 2)
434 				{
435 					if (tTd(28, 2))
436 						sm_dprintf("hes_getmailhost(%s): expansion too long: %.30s@%.30s\n",
437 							a->q_user,
438 							hp->po_name,
439 							hp->po_host);
440 					break;
441 				}
442 				info.data = pobuf;
443 				(void) sm_snprintf(pobuf, sizeof(pobuf),
444 					"%s@%s", hp->po_name, hp->po_host);
445 				info.size = strlen(info.data);
446 #  else /* HES_GETMAILHOST */
447 				break;
448 #  endif /* HES_GETMAILHOST */
449 			}
450 			if (tTd(28, 80))
451 				sm_dprintf("udbexpand: match %.*s: %.*s\n",
452 					(int) key.size, (char *) key.data,
453 					(int) info.size, (char *) info.data);
454 			a->q_flags &= ~QSELFREF;
455 
456 			if (bitset(EF_VRFYONLY, e->e_flags))
457 			{
458 				a->q_state = QS_VERIFIED;
459 				return EX_OK;
460 			}
461 
462 			breakout = true;
463 			if (info.size >= usersize)
464 				user = sm_malloc_x(info.size + 1);
465 			memmove(user, info.data, info.size);
466 			user[info.size] = '\0';
467 
468 			message("hesioded to %s", user);
469 			if (LogLevel > 10)
470 				sm_syslog(LOG_INFO, e->e_id,
471 					  "hesiod %.100s => %s",
472 					  e->e_to,
473 					  shortenstring(user, MAXSHORTSTR));
474 			naddrs = sendtolist(user, a, sendq, aliaslevel + 1, e);
475 
476 			if (naddrs > 0 && !bitset(QSELFREF, a->q_flags))
477 			{
478 				if (tTd(28, 5))
479 				{
480 					sm_dprintf("udbexpand: QS_EXPANDED ");
481 					printaddr(sm_debug_file(), a, false);
482 				}
483 				a->q_state = QS_EXPANDED;
484 			}
485 
486 			/*
487 			**  If this address has a -request address, reflect
488 			**  it into the envelope.
489 			*/
490 
491 			(void) sm_strlcpyn(keybuf, sizeof(keybuf), 2, a->q_user,
492 					   ":mailsender");
493 			keylen = strlen(keybuf);
494 			key.data = keybuf;
495 			key.size = keylen;
496 			i = hes_udb_get(&key, &info);
497 			if (i != 0 || info.size <= 0)
498 				break;
499 			a->q_owner = sm_rpool_malloc_x(e->e_rpool,
500 						       info.size + 1);
501 			memmove(a->q_owner, info.data, info.size);
502 			a->q_owner[info.size] = '\0';
503 			break;
504 # endif /* HESIOD */
505 
506 		  case UDB_REMOTE:
507 			/* not yet implemented */
508 			break;
509 
510 		  case UDB_FORWARD:
511 			if (bitset(EF_VRFYONLY, e->e_flags))
512 			{
513 				a->q_state = QS_VERIFIED;
514 				return EX_OK;
515 			}
516 			i = strlen(up->udb_fwdhost) + strlen(a->q_user) + 1;
517 			if (i >= usersize)
518 			{
519 				usersize = i + 1;
520 				user = sm_malloc_x(usersize);
521 			}
522 			(void) sm_strlcpyn(user, usersize, 3,
523 					a->q_user, "@", up->udb_fwdhost);
524 			message("expanded to %s", user);
525 			a->q_flags &= ~QSELFREF;
526 			naddrs = sendtolist(user, a, sendq, aliaslevel + 1, e);
527 			if (naddrs > 0 && !bitset(QSELFREF, a->q_flags))
528 			{
529 				if (tTd(28, 5))
530 				{
531 					sm_dprintf("udbexpand: QS_EXPANDED ");
532 					printaddr(sm_debug_file(), a, false);
533 				}
534 				a->q_state = QS_EXPANDED;
535 			}
536 			breakout = true;
537 			break;
538 
539 		  case UDB_EOLIST:
540 			breakout = true;
541 			break;
542 
543 		  default:
544 			/* unknown entry type */
545 			break;
546 		}
547 		/* XXX if an exception occurs, there is a storage leak */
548 		if (user != userbuf)
549 			sm_free(user); /* XXX */
550 	}
551 	return EX_OK;
552 }
553 /*
554 **  UDBSENDER -- return canonical external name of sender, given local name
555 **
556 **	Parameters:
557 **		sender -- the name of the sender on the local machine.
558 **		rpool -- resource pool from which to allocate result
559 **
560 **	Returns:
561 **		The external name for this sender, if derivable from the
562 **			database.  Storage allocated from rpool.
563 **		NULL -- if nothing is changed from the database.
564 **
565 **	Side Effects:
566 **		none.
567 */
568 
569 char *
570 udbsender(sender, rpool)
571 	char *sender;
572 	SM_RPOOL_T *rpool;
573 {
574 	return udbmatch(sender, "mailname", rpool);
575 }
576 /*
577 **  UDBMATCH -- match user in field, return result of lookup.
578 **
579 **	Parameters:
580 **		user -- the name of the user.
581 **		field -- the field to look up.
582 **		rpool -- resource pool from which to allocate result
583 **
584 **	Returns:
585 **		The external name for this sender, if derivable from the
586 **			database.  Storage allocated from rpool.
587 **		NULL -- if nothing is changed from the database.
588 **
589 **	Side Effects:
590 **		none.
591 */
592 
593 static char *
594 udbmatch(user, field, rpool)
595 	char *user;
596 	char *field;
597 	SM_RPOOL_T *rpool;
598 {
599 	register struct udbent *up;
600 # if NEWDB || HESIOD
601 	register char *p;
602 	int keylen;
603 	DBT key, info;
604 # endif
605 	int i;
606 	char keybuf[MAXUDBKEY];
607 
608 	if (tTd(28, 1))
609 		sm_dprintf("udbmatch(%s, %s)\n", user, field);
610 
611 	if (!UdbInitialized)
612 	{
613 		if (_udbx_init(CurEnv) == EX_TEMPFAIL)
614 			return NULL;
615 	}
616 
617 	/* short circuit if no spec */
618 	if (SM_IS_EMPTY(UdbSpec))
619 		return NULL;
620 
621 	/* short circuit name begins with '\\' since it can't possibly match */
622 	if (user[0] == '\\')
623 		return NULL;
624 
625 	/* long names can never match and are a pain to deal with */
626 	i = strlen(field);
627 	if (i < sizeof("maildrop"))
628 		i = sizeof("maildrop");
629 	if ((strlen(user) + i) > sizeof(keybuf) - 4)
630 		return NULL;
631 
632 	/* names beginning with colons indicate metadata */
633 	if (user[0] == ':')
634 		return NULL;
635 
636 	/* build database key */
637 	(void) sm_strlcpyn(keybuf, sizeof(keybuf), 3, user, ":", field);
638 # if NEWDB || HESIOD
639 	keylen = strlen(keybuf);
640 # endif
641 
642 	for (up = UdbEnts; up->udb_type != UDB_EOLIST; up++)
643 	{
644 		/*
645 		**  Select action based on entry type.
646 		*/
647 
648 		switch (up->udb_type)
649 		{
650 # if NEWDB
651 		  case UDB_DBFETCH:
652 			memset(&key, '\0', sizeof(key));
653 			memset(&info, '\0', sizeof(info));
654 			key.data = keybuf;
655 			key.size = keylen;
656 #  if DB_VERSION_MAJOR < 2
657 			i = (*up->udb_dbp->get)(up->udb_dbp, &key, &info, 0);
658 #  else
659 			i = errno = (*up->udb_dbp->get)(up->udb_dbp, NULL,
660 							&key, &info, 0);
661 #  endif
662 			if (i != 0 || info.size <= 0)
663 			{
664 				if (tTd(28, 2))
665 					sm_dprintf("udbmatch: no match on %s (%d) via db\n",
666 						keybuf, keylen);
667 				continue;
668 			}
669 
670 			p = sm_rpool_malloc_x(rpool, info.size + 1);
671 			memmove(p, info.data, info.size);
672 			p[info.size] = '\0';
673 			if (tTd(28, 1))
674 				sm_dprintf("udbmatch ==> %s\n", p);
675 			return p;
676 # endif /* NEWDB */
677 
678 # if HESIOD
679 		  case UDB_HESIOD:
680 			key.data = keybuf;
681 			key.size = keylen;
682 			i = hes_udb_get(&key, &info);
683 			if (i != 0 || info.size <= 0)
684 			{
685 				if (tTd(28, 2))
686 					sm_dprintf("udbmatch: no match on %s (%d) via hesiod\n",
687 						keybuf, keylen);
688 				continue;
689 			}
690 
691 			p = sm_rpool_malloc_x(rpool, info.size + 1);
692 			memmove(p, info.data, info.size);
693 			p[info.size] = '\0';
694 			if (tTd(28, 1))
695 				sm_dprintf("udbmatch ==> %s\n", p);
696 			return p;
697 # endif /* HESIOD */
698 		}
699 	}
700 
701 	if (strcmp(field, "mailname") != 0)
702 		return NULL;
703 
704 	/*
705 	**  Nothing yet.  Search again for a default case.  But only
706 	**  use it if we also have a forward (:maildrop) pointer already
707 	**  in the database.
708 	*/
709 
710 	/* build database key */
711 	(void) sm_strlcpyn(keybuf, sizeof(keybuf), 2, user, ":maildrop");
712 # if NEWDB || HESIOD
713 	keylen = strlen(keybuf);
714 # endif
715 
716 	for (up = UdbEnts; up->udb_type != UDB_EOLIST; up++)
717 	{
718 		switch (up->udb_type)
719 		{
720 # if NEWDB
721 		  case UDB_DBFETCH:
722 			/* get the default case for this database */
723 			if (up->udb_default == NULL)
724 			{
725 				memset(&key, '\0', sizeof(key));
726 				memset(&info, '\0', sizeof(info));
727 				key.data = ":default:mailname";
728 				key.size = strlen(key.data);
729 #  if DB_VERSION_MAJOR < 2
730 				i = (*up->udb_dbp->get)(up->udb_dbp,
731 							&key, &info, 0);
732 #  else /* DB_VERSION_MAJOR < 2 */
733 				i = errno = (*up->udb_dbp->get)(up->udb_dbp,
734 								NULL, &key,
735 								&info, 0);
736 #  endif /* DB_VERSION_MAJOR < 2 */
737 				if (i != 0 || info.size <= 0)
738 				{
739 					/* no default case */
740 					up->udb_default = "";
741 					continue;
742 				}
743 
744 				/* save the default case */
745 				up->udb_default = sm_pmalloc_x(info.size + 1);
746 				memmove(up->udb_default, info.data, info.size);
747 				up->udb_default[info.size] = '\0';
748 			}
749 			else if (up->udb_default[0] == '\0')
750 				continue;
751 
752 			/* we have a default case -- verify user:maildrop */
753 			memset(&key, '\0', sizeof(key));
754 			memset(&info, '\0', sizeof(info));
755 			key.data = keybuf;
756 			key.size = keylen;
757 #  if DB_VERSION_MAJOR < 2
758 			i = (*up->udb_dbp->get)(up->udb_dbp, &key, &info, 0);
759 #  else
760 			i = errno = (*up->udb_dbp->get)(up->udb_dbp, NULL,
761 							&key, &info, 0);
762 #  endif
763 			if (i != 0 || info.size <= 0)
764 			{
765 				/* nope -- no aliasing for this user */
766 				continue;
767 			}
768 
769 			/* they exist -- build the actual address */
770 			i = strlen(user) + strlen(up->udb_default) + 2;
771 			p = sm_rpool_malloc_x(rpool, i);
772 			(void) sm_strlcpyn(p, i, 3, user, "@", up->udb_default);
773 			if (tTd(28, 1))
774 				sm_dprintf("udbmatch ==> %s\n", p);
775 			return p;
776 # endif /* NEWDB */
777 
778 # if HESIOD
779 		  case UDB_HESIOD:
780 			/* get the default case for this database */
781 			if (up->udb_default == NULL)
782 			{
783 				key.data = ":default:mailname";
784 				key.size = strlen(key.data);
785 				i = hes_udb_get(&key, &info);
786 
787 				if (i != 0 || info.size <= 0)
788 				{
789 					/* no default case */
790 					up->udb_default = "";
791 					continue;
792 				}
793 
794 				/* save the default case */
795 				up->udb_default = sm_pmalloc_x(info.size + 1);
796 				memmove(up->udb_default, info.data, info.size);
797 				up->udb_default[info.size] = '\0';
798 			}
799 			else if (up->udb_default[0] == '\0')
800 				continue;
801 
802 			/* we have a default case -- verify user:maildrop */
803 			key.data = keybuf;
804 			key.size = keylen;
805 			i = hes_udb_get(&key, &info);
806 			if (i != 0 || info.size <= 0)
807 			{
808 				/* nope -- no aliasing for this user */
809 				continue;
810 			}
811 
812 			/* they exist -- build the actual address */
813 			i = strlen(user) + strlen(up->udb_default) + 2;
814 			p = sm_rpool_malloc_x(rpool, i);
815 			(void) sm_strlcpyn(p, i, 3, user, "@", up->udb_default);
816 			if (tTd(28, 1))
817 				sm_dprintf("udbmatch ==> %s\n", p);
818 			return p;
819 			break;
820 # endif /* HESIOD */
821 		}
822 	}
823 
824 	/* still nothing....  too bad */
825 	return NULL;
826 }
827 /*
828 **  UDB_MAP_LOOKUP -- look up arbitrary entry in user database map
829 **
830 **	Parameters:
831 **		map -- the map being queried.
832 **		name -- the name to look up.
833 **		av -- arguments to the map lookup.
834 **		statp -- to get any error status.
835 **
836 **	Returns:
837 **		NULL if name not found in map.
838 **		The rewritten name otherwise.
839 */
840 
841 /* ARGSUSED3 */
842 char *
843 udb_map_lookup(map, name, av, statp)
844 	MAP *map;
845 	char *name;
846 	char **av;
847 	int *statp;
848 {
849 	char *val;
850 	char *key;
851 	char *SM_NONVOLATILE result = NULL;
852 	char keybuf[MAXNAME + 1];	/* EAI:ok */
853 
854 	if (tTd(28, 20) || tTd(38, 20))
855 		sm_dprintf("udb_map_lookup(%s, %s)\n", map->map_mname, name);
856 
857 	if (bitset(MF_NOFOLDCASE, map->map_mflags))
858 		key = name;
859 	else
860 	{
861 		int keysize = strlen(name);
862 
863 		if (keysize > sizeof(keybuf) - 1)
864 			keysize = sizeof(keybuf) - 1;
865 		memmove(keybuf, name, keysize);
866 		keybuf[keysize] = '\0';
867 		makelower_buf(keybuf, keybuf, sizeof(keybuf));
868 		key = keybuf;
869 	}
870 	val = udbmatch(key, map->map_file, NULL);
871 	if (val == NULL)
872 		return NULL;
873 	SM_TRY
874 		if (bitset(MF_MATCHONLY, map->map_mflags))
875 			result = map_rewrite(map, name, strlen(name), NULL);
876 		else
877 			result = map_rewrite(map, val, strlen(val), av);
878 	SM_FINALLY
879 		sm_free(val);
880 	SM_END_TRY
881 	if (key != name && key != keybuf)
882 		SM_FREE(key);
883 	return result;
884 }
885 /*
886 **  _UDBX_INIT -- parse the UDB specification, opening any valid entries.
887 **
888 **	Parameters:
889 **		e -- the current envelope.
890 **
891 **	Returns:
892 **		EX_TEMPFAIL -- if it appeared it couldn't get hold of a
893 **			database due to a host being down or some similar
894 **			(recoverable) situation.
895 **		EX_OK -- otherwise.
896 **
897 **	Side Effects:
898 **		Fills in the UdbEnts structure from UdbSpec.
899 */
900 
901 # define MAXUDBOPTS	27
902 
903 static int
904 _udbx_init(e)
905 	ENVELOPE *e;
906 {
907 	int ents = 0;
908 	register char *p;
909 	register struct udbent *up;
910 
911 	if (UdbInitialized)
912 		return EX_OK;
913 
914 # ifdef UDB_DEFAULT_SPEC
915 	if (UdbSpec == NULL)
916 		UdbSpec = UDB_DEFAULT_SPEC;
917 # endif
918 
919 	p = UdbSpec;
920 	up = UdbEnts;
921 	while (p != NULL)
922 	{
923 		char *spec;
924 # if NEWDB
925 		int l;
926 # endif
927 		struct udb_option opts[MAXUDBOPTS + 1];
928 
929 		while (*p == ' ' || *p == '\t' || *p == ',')
930 			p++;
931 		if (*p == '\0')
932 			break;
933 		spec = p;
934 		p = strchr(p, ',');
935 		if (p != NULL)
936 			*p++ = '\0';
937 
938 		if (ents >= MAXUDBENT)
939 		{
940 			syserr("Maximum number of UDB entries exceeded");
941 			break;
942 		}
943 
944 		/* extract options */
945 		(void) _udb_parsespec(spec, opts, MAXUDBOPTS);
946 
947 		/*
948 		**  Decode database specification.
949 		**
950 		**	In the sendmail tradition, the leading character
951 		**	defines the semantics of the rest of the entry.
952 		**
953 		**	@hostname --	forward email to the indicated host.
954 		**			This should be the last in the list,
955 		**			since it always matches the input.
956 		**	/dbname	 --	search the named database on the local
957 		**			host using the Berkeley db package.
958 		**	Hesiod --	search the named database with BIND
959 		**			using the MIT Hesiod package.
960 		*/
961 
962 		switch (*spec)
963 		{
964 		  case '@':	/* forward to remote host */
965 			up->udb_type = UDB_FORWARD;
966 			up->udb_pid = CurrentPid;
967 			up->udb_fwdhost = spec + 1;
968 			ents++;
969 			up++;
970 			break;
971 
972 # if HESIOD
973 		  case 'h':	/* use hesiod */
974 		  case 'H':
975 			if (!SM_STRCASEEQ(spec, "hesiod"))
976 				goto badspec;
977 			up->udb_type = UDB_HESIOD;
978 			up->udb_pid = CurrentPid;
979 			ents++;
980 			up++;
981 			break;
982 # endif /* HESIOD */
983 
984 # if NEWDB
985 		  case '/':	/* look up remote name */
986 			l = strlen(spec);
987 			if (l > 3 && strcmp(&spec[l - 3], ".db") == 0)
988 			{
989 				up->udb_dbname = spec;
990 			}
991 			else
992 			{
993 				up->udb_dbname = sm_pmalloc_x(l + 4);
994 				(void) sm_strlcpyn(up->udb_dbname, l + 4, 2,
995 						   spec, ".db");
996 			}
997 			errno = 0;
998 #  if DB_VERSION_MAJOR < 2
999 			up->udb_dbp = dbopen(up->udb_dbname, O_RDONLY,
1000 					     0644, DB_BTREE, NULL);
1001 #  else /* DB_VERSION_MAJOR < 2 */
1002 			{
1003 				int flags = DB_RDONLY;
1004 #   if DB_VERSION_MAJOR > 2
1005 				int ret;
1006 #   endif /* DB_VERSION_MAJOR > 2 */
1007 
1008 				SM_DB_FLAG_ADD(flags);
1009 				up->udb_dbp = NULL;
1010 #   if DB_VERSION_MAJOR > 2
1011 				ret = db_create(&up->udb_dbp, NULL, 0);
1012 				if (ret != 0)
1013 				{
1014 					(void) up->udb_dbp->close(up->udb_dbp,
1015 								  0);
1016 					up->udb_dbp = NULL;
1017 				}
1018 				else
1019 				{
1020 					ret = up->udb_dbp->open(up->udb_dbp,
1021 								DBTXN
1022 								up->udb_dbname,
1023 								NULL,
1024 								DB_BTREE,
1025 								flags,
1026 								0644);
1027 					if (ret != 0)
1028 					{
1029 #    ifdef DB_OLD_VERSION
1030 						if (ret == DB_OLD_VERSION)
1031 							ret = EINVAL;
1032 #    endif
1033 						(void) up->udb_dbp->close(up->udb_dbp, 0);
1034 						up->udb_dbp = NULL;
1035 					}
1036 				}
1037 				errno = ret;
1038 #   else /* DB_VERSION_MAJOR > 2 */
1039 				errno = db_open(up->udb_dbname, DB_BTREE,
1040 						flags, 0644, NULL,
1041 						NULL, &up->udb_dbp);
1042 #   endif /* DB_VERSION_MAJOR > 2 */
1043 			}
1044 #  endif /* DB_VERSION_MAJOR < 2 */
1045 			if (up->udb_dbp == NULL)
1046 			{
1047 				if (tTd(28, 1))
1048 				{
1049 					int save_errno = errno;
1050 
1051 #  if DB_VERSION_MAJOR < 2
1052 					sm_dprintf("dbopen(%s): %s\n",
1053 #  else /* DB_VERSION_MAJOR < 2 */
1054 					sm_dprintf("db_open(%s): %s\n",
1055 #  endif /* DB_VERSION_MAJOR < 2 */
1056 						up->udb_dbname,
1057 						sm_errstring(errno));
1058 					errno = save_errno;
1059 				}
1060 				if (errno != ENOENT && errno != EACCES)
1061 				{
1062 					if (LogLevel > 2)
1063 						sm_syslog(LOG_ERR, e->e_id,
1064 #  if DB_VERSION_MAJOR < 2
1065 							  "dbopen(%s): %s",
1066 #  else /* DB_VERSION_MAJOR < 2 */
1067 							  "db_open(%s): %s",
1068 #  endif /* DB_VERSION_MAJOR < 2 */
1069 							  up->udb_dbname,
1070 							  sm_errstring(errno));
1071 					up->udb_type = UDB_EOLIST;
1072 					if (up->udb_dbname != spec)
1073 						sm_free(up->udb_dbname); /* XXX */
1074 					goto tempfail;
1075 				}
1076 				if (up->udb_dbname != spec)
1077 					sm_free(up->udb_dbname); /* XXX */
1078 				break;
1079 			}
1080 			if (tTd(28, 1))
1081 			{
1082 #  if DB_VERSION_MAJOR < 2
1083 				sm_dprintf("_udbx_init: dbopen(%s)\n",
1084 #  else /* DB_VERSION_MAJOR < 2 */
1085 				sm_dprintf("_udbx_init: db_open(%s)\n",
1086 #  endif /* DB_VERSION_MAJOR < 2 */
1087 					up->udb_dbname);
1088 			}
1089 			up->udb_type = UDB_DBFETCH;
1090 			up->udb_pid = CurrentPid;
1091 			ents++;
1092 			up++;
1093 			break;
1094 # endif /* NEWDB */
1095 
1096 		  default:
1097 # if HESIOD
1098 badspec:
1099 # endif
1100 			syserr("Unknown UDB spec %s", spec);
1101 			break;
1102 		}
1103 	}
1104 	up->udb_type = UDB_EOLIST;
1105 
1106 	if (tTd(28, 4))
1107 	{
1108 		for (up = UdbEnts; up->udb_type != UDB_EOLIST; up++)
1109 		{
1110 			switch (up->udb_type)
1111 			{
1112 			  case UDB_REMOTE:
1113 				sm_dprintf("REMOTE: addr %s, timeo %d\n",
1114 					   anynet_ntoa((SOCKADDR *) &up->udb_addr),
1115 					   up->udb_timeout);
1116 				break;
1117 
1118 			  case UDB_DBFETCH:
1119 # if NEWDB
1120 				sm_dprintf("FETCH: file %s\n", up->udb_dbname);
1121 # else
1122 				sm_dprintf("FETCH\n");
1123 # endif
1124 				break;
1125 
1126 			  case UDB_FORWARD:
1127 				sm_dprintf("FORWARD: host %s\n",
1128 					up->udb_fwdhost);
1129 				break;
1130 
1131 			  case UDB_HESIOD:
1132 				sm_dprintf("HESIOD\n");
1133 				break;
1134 
1135 			  default:
1136 				sm_dprintf("UNKNOWN\n");
1137 				break;
1138 			}
1139 		}
1140 	}
1141 
1142 	UdbInitialized = true;
1143 	errno = 0;
1144 	return EX_OK;
1145 
1146 	/*
1147 	**  On temporary failure, back out anything we've already done
1148 	*/
1149 
1150 # if NEWDB
1151   tempfail:
1152 	for (up = UdbEnts; up->udb_type != UDB_EOLIST; up++)
1153 	{
1154 		if (up->udb_type == UDB_DBFETCH)
1155 		{
1156 #  if DB_VERSION_MAJOR < 2
1157 			(*up->udb_dbp->close)(up->udb_dbp);
1158 #  else
1159 			errno = (*up->udb_dbp->close)(up->udb_dbp, 0);
1160 #  endif
1161 			if (tTd(28, 1))
1162 				sm_dprintf("_udbx_init: db->close(%s)\n",
1163 					up->udb_dbname);
1164 		}
1165 	}
1166 # endif /* NEWDB */
1167 	return EX_TEMPFAIL;
1168 }
1169 
1170 static int
1171 _udb_parsespec(udbspec, opt, maxopts)
1172 	char *udbspec;
1173 	struct udb_option opt[];
1174 	int maxopts;
1175 {
1176 	register char *spec;
1177 	register char *spec_end;
1178 	register int optnum;
1179 
1180 	spec_end = strchr(udbspec, ':');
1181 	for (optnum = 0; optnum < maxopts && (spec = spec_end) != NULL; optnum++)
1182 	{
1183 		register char *p;
1184 
1185 		while (SM_ISSPACE(*spec))
1186 			spec++;
1187 		spec_end = strchr(spec, ':');
1188 		if (spec_end != NULL)
1189 			*spec_end++ = '\0';
1190 
1191 		opt[optnum].udbo_name = spec;
1192 		opt[optnum].udbo_val = NULL;
1193 		p = strchr(spec, '=');
1194 		if (p != NULL)
1195 			opt[optnum].udbo_val = ++p;
1196 	}
1197 	return optnum;
1198 }
1199 /*
1200 **  _UDBX_CLOSE -- close all file based UDB entries.
1201 **
1202 **	Parameters:
1203 **		none
1204 **
1205 **	Returns:
1206 **		none
1207 */
1208 void
1209 _udbx_close()
1210 {
1211 	struct udbent *up;
1212 
1213 	if (!UdbInitialized)
1214 		return;
1215 
1216 	for (up = UdbEnts; up->udb_type != UDB_EOLIST; up++)
1217 	{
1218 		if (up->udb_pid != CurrentPid)
1219 			continue;
1220 
1221 # if NEWDB
1222 		if (up->udb_type == UDB_DBFETCH)
1223 		{
1224 #  if DB_VERSION_MAJOR < 2
1225 			(*up->udb_dbp->close)(up->udb_dbp);
1226 #  else
1227 			errno = (*up->udb_dbp->close)(up->udb_dbp, 0);
1228 #  endif
1229 		}
1230 		if (tTd(28, 1))
1231 			sm_dprintf("_udbx_close: db->close(%s)\n",
1232 				up->udb_dbname);
1233 # endif /* NEWDB */
1234 	}
1235 }
1236 
1237 # if HESIOD
1238 
1239 static int
1240 hes_udb_get(key, info)
1241 	DBT *key;
1242 	DBT *info;
1243 {
1244 	char *name, *type;
1245 	char **hp;
1246 	char kbuf[MAXUDBKEY + 1];
1247 
1248 	if (sm_strlcpy(kbuf, key->data, sizeof(kbuf)) >= sizeof(kbuf))
1249 		return 0;
1250 	name = kbuf;
1251 	type = strrchr(name, ':');
1252 	if (type == NULL)
1253 		return 1;
1254 	*type++ = '\0';
1255 	if (strchr(name, '@') != NULL)
1256 		return 1;
1257 
1258 	if (tTd(28, 1))
1259 		sm_dprintf("hes_udb_get(%s, %s)\n", name, type);
1260 
1261 	/* make the hesiod query */
1262 #  ifdef HESIOD_INIT
1263 	if (HesiodContext == NULL && hesiod_init(&HesiodContext) != 0)
1264 		return -1;
1265 	hp = hesiod_resolve(HesiodContext, name, type);
1266 #  else
1267 	hp = hes_resolve(name, type);
1268 #  endif
1269 	*--type = ':';
1270 #  ifdef HESIOD_INIT
1271 	if (hp == NULL)
1272 		return 1;
1273 	if (*hp == NULL)
1274 	{
1275 		hesiod_free_list(HesiodContext, hp);
1276 		if (errno == ECONNREFUSED || errno == EMSGSIZE)
1277 			return -1;
1278 		return 1;
1279 	}
1280 #  else /* HESIOD_INIT */
1281 	if (SM_IS_EMPTY(hp))
1282 	{
1283 		/* network problem or timeout */
1284 		if (hes_error() == HES_ER_NET)
1285 			return -1;
1286 
1287 		return 1;
1288 	}
1289 #  endif /* HESIOD_INIT */
1290 	else
1291 	{
1292 		/*
1293 		**  If there are multiple matches, just return the
1294 		**  first one.
1295 		**
1296 		**  XXX These should really be returned; for example,
1297 		**  XXX it is legal for :maildrop to be multi-valued.
1298 		*/
1299 
1300 		info->data = hp[0];
1301 		info->size = (size_t) strlen(info->data);
1302 	}
1303 
1304 	if (tTd(28, 80))
1305 		sm_dprintf("hes_udb_get => %s\n", *hp);
1306 
1307 	return 0;
1308 }
1309 # endif /* HESIOD */
1310 
1311 #else /* USERDB */
1312 
1313 int
1314 udbexpand(a, sendq, aliaslevel, e)
1315 	ADDRESS *a;
1316 	ADDRESS **sendq;
1317 	int aliaslevel;
1318 	ENVELOPE *e;
1319 {
1320 	return EX_OK;
1321 }
1322 
1323 #endif /* USERDB */
1324