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 #ifndef lint
10 static char sccsid[] = "@(#)recipient.c	5.33 (Berkeley) 07/12/92";
11 #endif /* not lint */
12 
13 # include <sys/types.h>
14 # include <sys/stat.h>
15 # include <sys/file.h>
16 # include <pwd.h>
17 # include "sendmail.h"
18 
19 /*
20 **  SENDTOLIST -- Designate a send list.
21 **
22 **	The parameter is a comma-separated list of people to send to.
23 **	This routine arranges to send to all of them.
24 **
25 **	Parameters:
26 **		list -- the send list.
27 **		ctladdr -- the address template for the person to
28 **			send to -- effective uid/gid are important.
29 **			This is typically the alias that caused this
30 **			expansion.
31 **		sendq -- a pointer to the head of a queue to put
32 **			these people into.
33 **
34 **	Returns:
35 **		none
36 **
37 **	Side Effects:
38 **		none.
39 */
40 
41 # define MAXRCRSN	10
42 
43 sendtolist(list, ctladdr, sendq, e)
44 	char *list;
45 	ADDRESS *ctladdr;
46 	ADDRESS **sendq;
47 	register ENVELOPE *e;
48 {
49 	register char *p;
50 	register ADDRESS *al;	/* list of addresses to send to */
51 	bool firstone;		/* set on first address sent */
52 	bool selfref;		/* set if this list includes ctladdr */
53 	char delimiter;		/* the address delimiter */
54 
55 	if (tTd(25, 1))
56 	{
57 		printf("sendto: %s\n   ctladdr=", list);
58 		printaddr(ctladdr, FALSE);
59 	}
60 
61 	/* heuristic to determine old versus new style addresses */
62 	if (ctladdr == NULL &&
63 	    (index(list, ',') != NULL || index(list, ';') != NULL ||
64 	     index(list, '<') != NULL || index(list, '(') != NULL))
65 		e->e_flags &= ~EF_OLDSTYLE;
66 	delimiter = ' ';
67 	if (!bitset(EF_OLDSTYLE, e->e_flags) || ctladdr != NULL)
68 		delimiter = ',';
69 
70 	firstone = TRUE;
71 	selfref = FALSE;
72 	al = NULL;
73 
74 	for (p = list; *p != '\0'; )
75 	{
76 		register ADDRESS *a;
77 		extern char *DelimChar;		/* defined in prescan */
78 
79 		/* parse the address */
80 		while (isspace(*p) || *p == ',')
81 			p++;
82 		a = parseaddr(p, (ADDRESS *) NULL, 1, delimiter, e);
83 		p = DelimChar;
84 		if (a == NULL)
85 			continue;
86 		a->q_next = al;
87 		a->q_alias = ctladdr;
88 
89 		/* see if this should be marked as a primary address */
90 		if (ctladdr == NULL ||
91 		    (firstone && *p == '\0' && bitset(QPRIMARY, ctladdr->q_flags)))
92 			a->q_flags |= QPRIMARY;
93 
94 		/* put on send queue or suppress self-reference */
95 		if (ctladdr != NULL && sameaddr(ctladdr, a))
96 			selfref = TRUE;
97 		else
98 			al = a;
99 		firstone = FALSE;
100 	}
101 
102 	/* if this alias doesn't include itself, delete ctladdr */
103 	if (!selfref && ctladdr != NULL)
104 		ctladdr->q_flags |= QDONTSEND;
105 
106 	/* arrange to send to everyone on the local send list */
107 	while (al != NULL)
108 	{
109 		register ADDRESS *a = al;
110 		extern ADDRESS *recipient();
111 
112 		al = a->q_next;
113 		a = recipient(a, sendq, e);
114 
115 		/* arrange to inherit full name */
116 		if (a->q_fullname == NULL && ctladdr != NULL)
117 			a->q_fullname = ctladdr->q_fullname;
118 	}
119 
120 	e->e_to = NULL;
121 }
122 /*
123 **  RECIPIENT -- Designate a message recipient
124 **
125 **	Saves the named person for future mailing.
126 **
127 **	Parameters:
128 **		a -- the (preparsed) address header for the recipient.
129 **		sendq -- a pointer to the head of a queue to put the
130 **			recipient in.  Duplicate supression is done
131 **			in this queue.
132 **
133 **	Returns:
134 **		The actual address in the queue.  This will be "a" if
135 **		the address is not a duplicate, else the original address.
136 **
137 **	Side Effects:
138 **		none.
139 */
140 
141 extern ADDRESS *getctladdr();
142 extern char	*RcptLogFile;
143 
144 ADDRESS *
145 recipient(a, sendq, e)
146 	register ADDRESS *a;
147 	register ADDRESS **sendq;
148 	register ENVELOPE *e;
149 {
150 	register ADDRESS *q;
151 	ADDRESS **pq;
152 	register struct mailer *m;
153 	register char *p;
154 	bool quoted = FALSE;		/* set if the addr has a quote bit */
155 	int findusercount = 0;
156 	char buf[MAXNAME];		/* unquoted image of the user name */
157 	extern bool safefile();
158 
159 	e->e_to = a->q_paddr;
160 	m = a->q_mailer;
161 	errno = 0;
162 	if (tTd(26, 1))
163 	{
164 		printf("\nrecipient: ");
165 		printaddr(a, FALSE);
166 	}
167 
168 	/* break aliasing loops */
169 	if (AliasLevel > MAXRCRSN)
170 	{
171 		usrerr("aliasing/forwarding loop broken");
172 		return (a);
173 	}
174 
175 	/*
176 	**  Finish setting up address structure.
177 	*/
178 
179 	/* set the queue timeout */
180 	a->q_timeout = TimeOut;
181 
182 	/* map user & host to lower case if requested on non-aliases */
183 	if (a->q_alias == NULL)
184 		loweraddr(a);
185 
186 	/* get unquoted user for file, program or user.name check */
187 	(void) strcpy(buf, a->q_user);
188 	for (p = buf; *p != '\0' && !quoted; p++)
189 	{
190 		if (*p == '\\')
191 			quoted = TRUE;
192 	}
193 	stripquotes(buf);
194 
195 	/* do sickly crude mapping for program mailing, etc. */
196 	if (m == LocalMailer && buf[0] == '|')
197 	{
198 		a->q_mailer = m = ProgMailer;
199 		a->q_user++;
200 		if (a->q_alias == NULL && !ForceMail)
201 		{
202 			a->q_flags |= QDONTSEND|QBADADDR;
203 			usrerr("Cannot mail directly to programs");
204 		}
205 	}
206 
207 	/*
208 	**  Look up this person in the recipient list.
209 	**	If they are there already, return, otherwise continue.
210 	**	If the list is empty, just add it.  Notice the cute
211 	**	hack to make from addresses suppress things correctly:
212 	**	the QDONTSEND bit will be set in the send list.
213 	**	[Please note: the emphasis is on "hack."]
214 	*/
215 
216 	for (pq = sendq; (q = *pq) != NULL; pq = &q->q_next)
217 	{
218 		if (!ForceMail && sameaddr(q, a))
219 		{
220 			if (tTd(26, 1))
221 			{
222 				printf("%s in sendq: ", a->q_paddr);
223 				printaddr(q, FALSE);
224 			}
225 			if (!bitset(QDONTSEND, a->q_flags))
226 				message(Arpa_Info, "duplicate suppressed");
227 			if (!bitset(QPRIMARY, q->q_flags))
228 				q->q_flags |= a->q_flags;
229 			return (q);
230 		}
231 	}
232 
233 	/* add address on list */
234 	*pq = a;
235 	a->q_next = NULL;
236 	e->e_nrcpts++;
237 
238 	if (a->q_alias == NULL && RcptLogFile != NULL &&
239 	    !bitset(QDONTSEND, a->q_flags))
240 	{
241 		static int RcptLogFd = -1;
242 
243 		/*
244 		**  Log the incoming recipient name before aliasing,
245 		**  expanding, forwarding, rewriting, and all that jazz.
246 		**  We'll use this to track down out-of-date aliases,
247 		**  host names, and so forth.
248 		*/
249 
250 		if (RcptLogFd < 0)
251 		{
252 			/* try to open the log file */
253 			RcptLogFd = open(RcptLogFile, O_WRONLY|O_APPEND|O_CREAT, 0666);
254 			if (RcptLogFd >= 0)
255 				(void) fcntl(RcptLogFd, F_SETFD, 1);
256 		}
257 		if (RcptLogFd >= 0)
258 		{
259 			int l = strlen(a->q_paddr);
260 
261 			a->q_paddr[l] = '\n';
262 			if (write(RcptLogFd, a->q_paddr, l + 1) < 0)
263 			{
264 				(void) close(RcptLogFd);
265 				RcptLogFd = -1;
266 			}
267 			a->q_paddr[l] = '\0';
268 		}
269 	}
270 
271 	/*
272 	**  Alias the name and handle :include: specs.
273 	*/
274 
275   trylocaluser:
276 	if (m == LocalMailer && !bitset(QDONTSEND, a->q_flags))
277 	{
278 		if (strncmp(a->q_user, ":include:", 9) == 0)
279 		{
280 			a->q_flags |= QDONTSEND;
281 			if (a->q_alias == NULL && !ForceMail)
282 			{
283 				a->q_flags |= QBADADDR;
284 				usrerr("Cannot mail directly to :include:s");
285 			}
286 			else
287 			{
288 				message(Arpa_Info, "including file %s", &a->q_user[9]);
289 				include(&a->q_user[9], FALSE, a, sendq, e);
290 			}
291 		}
292 		else
293 		{
294 			/* try aliasing */
295 			alias(a, sendq, e);
296 
297 # ifdef USERDB
298 			/* if not aliased, look it up in the user database */
299 			if (!bitset(QDONTSEND|QNOTREMOTE, a->q_flags))
300 			{
301 				extern int udbexpand();
302 
303 				if (udbexpand(a, sendq, e) == EX_TEMPFAIL)
304 				{
305 					a->q_flags |= QQUEUEUP;
306 					if (e->e_message == NULL)
307 						e->e_message = newstr("Deferred: user database error");
308 # ifdef LOG
309 					if (LogLevel > 3)
310 						syslog(LOG_INFO, "%s: deferred: udbexpand",
311 							e->e_id);
312 # endif
313 					message(Arpa_Info, "queued (user database error)");
314 					return (a);
315 				}
316 			}
317 # endif
318 		}
319 	}
320 
321 	/*
322 	**  If the user is local and still being sent, verify that
323 	**  the address is good.  If it is, try to forward.
324 	**  If the address is already good, we have a forwarding
325 	**  loop.  This can be broken by just sending directly to
326 	**  the user (which is probably correct anyway).
327 	*/
328 
329 	if (bitset(QDONTSEND, a->q_flags) || m != LocalMailer)
330 		return (a);
331 
332 	/* see if this is to a file */
333 	if (buf[0] == '/')
334 	{
335 		struct stat stb;
336 		extern bool writable();
337 
338 		p = rindex(buf, '/');
339 		/* check if writable or creatable */
340 		if (a->q_alias == NULL && !QueueRun && !ForceMail)
341 		{
342 			a->q_flags |= QDONTSEND|QBADADDR;
343 			usrerr("Cannot mail directly to files");
344 		}
345 		else if ((stat(buf, &stb) >= 0) ? (!writable(&stb)) :
346 		    (*p = '\0', !safefile(buf, getruid(), S_IWRITE|S_IEXEC)))
347 		{
348 			a->q_flags |= QBADADDR;
349 			giveresponse(EX_CANTCREAT, m, e);
350 		}
351 		return (a);
352 	}
353 
354 	/*
355 	**  If we have a level two config file, then pass the name through
356 	**  Ruleset 5 before sending it off.  Ruleset 5 has the right
357 	**  to send rewrite it to another mailer.  This gives us a hook
358 	**  after local aliasing has been done.
359 	*/
360 
361 	if (tTd(29, 5))
362 	{
363 		printf("recipient: testing local?  cl=%d, rr5=%x\n\t",
364 			ConfigLevel, RewriteRules[5]);
365 		printaddr(a, FALSE);
366 	}
367 	if (!bitset(QNOTREMOTE, a->q_flags) && ConfigLevel >= 2 &&
368 	    RewriteRules[5] != NULL)
369 	{
370 		maplocaluser(a, sendq, e);
371 	}
372 
373 	/*
374 	**  If it didn't get rewritten to another mailer, go ahead
375 	**  and deliver it.
376 	*/
377 
378 	if (!bitset(QDONTSEND, a->q_flags))
379 	{
380 		register struct passwd *pw;
381 		extern struct passwd *finduser();
382 
383 		/* warning -- finduser may trash buf */
384 		pw = finduser(buf);
385 		if (pw == NULL)
386 		{
387 			a->q_flags |= QBADADDR;
388 			giveresponse(EX_NOUSER, m, e);
389 		}
390 		else
391 		{
392 			char nbuf[MAXNAME];
393 
394 			if (strcmp(a->q_user, pw->pw_name) != 0)
395 			{
396 				/* name was a fuzzy match */
397 				a->q_user = newstr(pw->pw_name);
398 				if (findusercount++ > 3)
399 				{
400 					usrerr("aliasing/forwarding loop for %s broken",
401 						pw->pw_name);
402 					return (a);
403 				}
404 
405 				/* see if it aliases */
406 				(void) strcpy(buf, pw->pw_name);
407 				goto trylocaluser;
408 			}
409 			a->q_home = newstr(pw->pw_dir);
410 			a->q_uid = pw->pw_uid;
411 			a->q_gid = pw->pw_gid;
412 			a->q_flags |= QGOODUID;
413 			buildfname(pw->pw_gecos, pw->pw_name, nbuf);
414 			if (nbuf[0] != '\0')
415 				a->q_fullname = newstr(nbuf);
416 			if (!quoted)
417 				forward(a, sendq, e);
418 		}
419 	}
420 	return (a);
421 }
422 /*
423 **  FINDUSER -- find the password entry for a user.
424 **
425 **	This looks a lot like getpwnam, except that it may want to
426 **	do some fancier pattern matching in /etc/passwd.
427 **
428 **	This routine contains most of the time of many sendmail runs.
429 **	It deserves to be optimized.
430 **
431 **	Parameters:
432 **		name -- the name to match against.
433 **
434 **	Returns:
435 **		A pointer to a pw struct.
436 **		NULL if name is unknown or ambiguous.
437 **
438 **	Side Effects:
439 **		may modify name.
440 */
441 
442 struct passwd *
443 finduser(name)
444 	char *name;
445 {
446 	register struct passwd *pw;
447 	register char *p;
448 	extern struct passwd *getpwent();
449 	extern struct passwd *getpwnam();
450 
451 	/* map upper => lower case */
452 	for (p = name; *p != '\0'; p++)
453 	{
454 		if (isascii(*p) && isupper(*p))
455 			*p = tolower(*p);
456 	}
457 
458 	/* look up this login name using fast path */
459 	if ((pw = getpwnam(name)) != NULL)
460 		return (pw);
461 
462 #ifdef MATCHGECOS
463 	/* see if fuzzy matching allowed */
464 	if (!MatchGecos)
465 		return NULL;
466 
467 	/* search for a matching full name instead */
468 	for (p = name; *p != '\0'; p++)
469 	{
470 		if (*p == (SpaceSub & 0177) || *p == '_')
471 			*p = ' ';
472 	}
473 	(void) setpwent();
474 	while ((pw = getpwent()) != NULL)
475 	{
476 		char buf[MAXNAME];
477 
478 		buildfname(pw->pw_gecos, pw->pw_name, buf);
479 		if (index(buf, ' ') != NULL && !strcasecmp(buf, name))
480 		{
481 			message(Arpa_Info, "sending to login name %s", pw->pw_name);
482 			return (pw);
483 		}
484 	}
485 #endif
486 	return (NULL);
487 }
488 /*
489 **  WRITABLE -- predicate returning if the file is writable.
490 **
491 **	This routine must duplicate the algorithm in sys/fio.c.
492 **	Unfortunately, we cannot use the access call since we
493 **	won't necessarily be the real uid when we try to
494 **	actually open the file.
495 **
496 **	Notice that ANY file with ANY execute bit is automatically
497 **	not writable.  This is also enforced by mailfile.
498 **
499 **	Parameters:
500 **		s -- pointer to a stat struct for the file.
501 **
502 **	Returns:
503 **		TRUE -- if we will be able to write this file.
504 **		FALSE -- if we cannot write this file.
505 **
506 **	Side Effects:
507 **		none.
508 */
509 
510 bool
511 writable(s)
512 	register struct stat *s;
513 {
514 	int euid, egid;
515 	int bits;
516 
517 	if (bitset(0111, s->st_mode))
518 		return (FALSE);
519 	euid = getruid();
520 	egid = getrgid();
521 	if (geteuid() == 0)
522 	{
523 		if (bitset(S_ISUID, s->st_mode))
524 			euid = s->st_uid;
525 		if (bitset(S_ISGID, s->st_mode))
526 			egid = s->st_gid;
527 	}
528 
529 	if (euid == 0)
530 		return (TRUE);
531 	bits = S_IWRITE;
532 	if (euid != s->st_uid)
533 	{
534 		bits >>= 3;
535 		if (egid != s->st_gid)
536 			bits >>= 3;
537 	}
538 	return ((s->st_mode & bits) != 0);
539 }
540 /*
541 **  INCLUDE -- handle :include: specification.
542 **
543 **	Parameters:
544 **		fname -- filename to include.
545 **		forwarding -- if TRUE, we are reading a .forward file.
546 **			if FALSE, it's a :include: file.
547 **		ctladdr -- address template to use to fill in these
548 **			addresses -- effective user/group id are
549 **			the important things.
550 **		sendq -- a pointer to the head of the send queue
551 **			to put these addresses in.
552 **
553 **	Returns:
554 **		none.
555 **
556 **	Side Effects:
557 **		reads the :include: file and sends to everyone
558 **		listed in that file.
559 */
560 
561 static jmp_buf	CtxIncludeTimeout;
562 
563 include(fname, forwarding, ctladdr, sendq, e)
564 	char *fname;
565 	bool forwarding;
566 	ADDRESS *ctladdr;
567 	ADDRESS **sendq;
568 	ENVELOPE *e;
569 {
570 	register FILE *fp;
571 	char *oldto = e->e_to;
572 	char *oldfilename = FileName;
573 	int oldlinenumber = LineNumber;
574 	register EVENT *ev = NULL;
575 	char buf[MAXLINE];
576 	static int includetimeout();
577 
578 	/*
579 	**  If home directory is remote mounted but server is down,
580 	**  this can hang or give errors; use a timeout to avoid this
581 	*/
582 
583 	if (setjmp(CtxIncludeTimeout) != 0)
584 	{
585 		ctladdr->q_flags |= QQUEUEUP|QDONTSEND;
586 		errno = 0;
587 		usrerr("451 open timeout on %s", fname);
588 		return;
589 	}
590 	ev = setevent((time_t) 60, includetimeout, 0);
591 
592 	/* if forwarding, the input file must be marked safe */
593 	if (forwarding && !safefile(fname, ctladdr->q_uid, S_IREAD))
594 	{
595 		/* don't use this .forward file */
596 		clrevent(ev);
597 		return;
598 	}
599 
600 	fp = fopen(fname, "r");
601 	if (fp == NULL)
602 	{
603 		usrerr("Cannot open %s", fname);
604 		return;
605 	}
606 
607 	if (getctladdr(ctladdr) == NULL)
608 	{
609 		struct stat st;
610 
611 		if (fstat(fileno(fp), &st) < 0)
612 			syserr("Cannot fstat %s!", fname);
613 		ctladdr->q_uid = st.st_uid;
614 		ctladdr->q_gid = st.st_gid;
615 		ctladdr->q_flags |= QGOODUID;
616 	}
617 
618 	clrevent(ev);
619 
620 	/* read the file -- each line is a comma-separated list. */
621 	FileName = fname;
622 	LineNumber = 0;
623 	while (fgets(buf, sizeof buf, fp) != NULL)
624 	{
625 		register char *p = index(buf, '\n');
626 
627 		LineNumber++;
628 		if (p != NULL)
629 			*p = '\0';
630 		if (buf[0] == '\0' || buf[0] == '#')
631 			continue;
632 		e->e_to = oldto;
633 		message(Arpa_Info, "%s to %s",
634 			forwarding ? "forwarding" : "sending", buf);
635 		AliasLevel++;
636 		sendtolist(buf, ctladdr, sendq, e);
637 		AliasLevel--;
638 	}
639 
640 	(void) fclose(fp);
641 	FileName = oldfilename;
642 	LineNumber = oldlinenumber;
643 }
644 
645 static
646 includetimeout()
647 {
648 	longjmp(CtxIncludeTimeout, 1);
649 }
650 /*
651 **  SENDTOARGV -- send to an argument vector.
652 **
653 **	Parameters:
654 **		argv -- argument vector to send to.
655 **
656 **	Returns:
657 **		none.
658 **
659 **	Side Effects:
660 **		puts all addresses on the argument vector onto the
661 **			send queue.
662 */
663 
664 sendtoargv(argv, e)
665 	register char **argv;
666 	register ENVELOPE *e;
667 {
668 	register char *p;
669 
670 	while ((p = *argv++) != NULL)
671 	{
672 		if (argv[0] != NULL && argv[1] != NULL && !strcasecmp(argv[0], "at"))
673 		{
674 			char nbuf[MAXNAME];
675 
676 			if (strlen(p) + strlen(argv[1]) + 2 > sizeof nbuf)
677 				usrerr("address overflow");
678 			else
679 			{
680 				(void) strcpy(nbuf, p);
681 				(void) strcat(nbuf, "@");
682 				(void) strcat(nbuf, argv[1]);
683 				p = newstr(nbuf);
684 				argv += 2;
685 			}
686 		}
687 		sendtolist(p, (ADDRESS *) NULL, &e->e_sendqueue, e);
688 	}
689 }
690 /*
691 **  GETCTLADDR -- get controlling address from an address header.
692 **
693 **	If none, get one corresponding to the effective userid.
694 **
695 **	Parameters:
696 **		a -- the address to find the controller of.
697 **
698 **	Returns:
699 **		the controlling address.
700 **
701 **	Side Effects:
702 **		none.
703 */
704 
705 ADDRESS *
706 getctladdr(a)
707 	register ADDRESS *a;
708 {
709 	while (a != NULL && !bitset(QGOODUID, a->q_flags))
710 		a = a->q_alias;
711 	return (a);
712 }
713