1 # include <stdio.h>
2 # include <pwd.h>
3 # include <signal.h>
4 # include "dlvrmail.h"
5 # ifdef LOG
6 # include <log.h>
7 # endif LOG
8 
9 static char SccsId[] = "@(#)deliver.c	1.10	10/27/80";
10 
11 /*
12 **  DELIVER -- Deliver a message to a particular address.
13 **
14 **	Algorithm:
15 **		Compute receiving network (i.e., mailer), host, & user.
16 **		If local, see if this is really a program name.
17 **		Build argument for the mailer.
18 **		Create pipe through edit fcn if appropriate.
19 **		Fork.
20 **			Child: call mailer
21 **		Parent: call editfcn if specified.
22 **		Wait for mailer to finish.
23 **		Interpret exit status.
24 **
25 **	Parameters:
26 **		to -- the address to deliver the message to.
27 **		editfcn -- if non-NULL, we want to call this function
28 **			to output the letter (instead of just out-
29 **			putting it raw).
30 **
31 **	Returns:
32 **		zero -- successfully delivered.
33 **		else -- some failure, see ExitStat for more info.
34 **
35 **	Side Effects:
36 **		The standard input is passed off to someone.
37 **
38 **	WARNING:
39 **		The standard input is shared amongst all children,
40 **		including the file pointer.  It is critical that the
41 **		parent waits for the child to finish before forking
42 **		another child.
43 **
44 **	Called By:
45 **		main
46 **		savemail
47 **
48 **	Files:
49 **		standard input -- must be opened to the message to
50 **			deliver.
51 */
52 
53 deliver(to, editfcn)
54 	addrq *to;
55 	int (*editfcn)();
56 {
57 	register struct mailer *m;
58 	char *host;
59 	char *user;
60 	extern struct passwd *getpwnam();
61 	char **pvp;
62 	extern char **buildargv();
63 	auto int st;
64 	register int i;
65 	register char *p;
66 	int pid;
67 	int pvect[2];
68 	extern FILE *fdopen();
69 	extern int errno;
70 	FILE *mfile;
71 	extern putheader();
72 	extern pipesig();
73 
74 	/*
75 	**  Compute receiving mailer, host, and to addreses.
76 	**	Do some initialization first.  To is the to address
77 	**	for error messages.
78 	*/
79 
80 	To = to->q_paddr;
81 	m = to->q_mailer;
82 	user = to->q_user;
83 	host = to->q_host;
84 	Errors = 0;
85 	errno = 0;
86 # ifdef DEBUG
87 	if (Debug)
88 		printf("deliver(%s [%d, `%s', `%s'])\n", To, m, host, user);
89 # endif DEBUG
90 
91 	/*
92 	**  Remove quote bits from user/host.
93 	*/
94 
95 	for (p = user; (*p++ &= 0177) != '\0'; )
96 		continue;
97 	if (host != NULL)
98 		for (p = host; (*p++ &= 0177) != '\0'; )
99 			continue;
100 
101 	/*
102 	**  Strip quote bits from names if the mailer wants it.
103 	*/
104 
105 	if (flagset(M_STRIPQ, m->m_flags))
106 	{
107 		stripquotes(user);
108 		stripquotes(host);
109 	}
110 
111 	/*
112 	**  See if this user name is "special".
113 	**	If the user is a program, diddle with the mailer spec.
114 	**	If the user name has a slash in it, assume that this
115 	**		is a file -- send it off without further ado.
116 	**		Note that this means that editfcn's will not
117 	**		be applied to the message.
118 	*/
119 
120 	if (m == &Mailer[0])
121 	{
122 		if (*user == '|')
123 		{
124 			user++;
125 			m = &Mailer[1];
126 		}
127 		else
128 		{
129 			if (index(user, '/') != NULL)
130 			{
131 				i = mailfile(user);
132 				giveresponse(i, TRUE, m);
133 				return (i);
134 			}
135 		}
136 	}
137 
138 	/*
139 	**  See if the user exists.
140 	**	Strictly, this is only needed to print a pretty
141 	**	error message.
142 	**
143 	**	>>>>>>>>>> This clause assumes that the local mailer
144 	**	>> NOTE >> cannot do any further aliasing; that
145 	**	>>>>>>>>>> function is subsumed by delivermail.
146 	*/
147 
148 	if (m == &Mailer[0])
149 	{
150 		if (getpwnam(user) == NULL)
151 		{
152 			giveresponse(EX_NOUSER, TRUE, m);
153 			return (EX_NOUSER);
154 		}
155 	}
156 
157 	/*
158 	**  If the mailer wants a From line, insert a new editfcn.
159 	*/
160 
161 	if (flagset(M_HDR, m->m_flags) && editfcn == NULL)
162 		editfcn = putheader;
163 
164 	/*
165 	**  Call the mailer.
166 	**	The argument vector gets built, pipes through 'editfcn'
167 	**	are created as necessary, and we fork & exec as
168 	**	appropriate.  In the parent, we call 'editfcn'.
169 	*/
170 
171 	pvp = buildargv(m->m_argv, m->m_flags, host, user, From.q_paddr);
172 	if (pvp == NULL)
173 	{
174 		usrerr("name too long");
175 		return (-1);
176 	}
177 	rewind(stdin);
178 
179 	/* create a pipe if we will need one */
180 	if (editfcn != NULL && pipe(pvect) < 0)
181 	{
182 		syserr("pipe");
183 		return (-1);
184 	}
185 # ifdef VFORK
186 	pid = vfork();
187 # else
188 	pid = fork();
189 # endif
190 	if (pid < 0)
191 	{
192 		syserr("Cannot fork");
193 		if (editfcn != NULL)
194 		{
195 			close(pvect[0]);
196 			close(pvect[1]);
197 		}
198 		return (-1);
199 	}
200 	else if (pid == 0)
201 	{
202 		/* child -- set up input & exec mailer */
203 		/* make diagnostic output be standard output */
204 		close(2);
205 		dup(1);
206 		signal(SIGINT, SIG_IGN);
207 		if (editfcn != NULL)
208 		{
209 			close(0);
210 			if (dup(pvect[0]) < 0)
211 			{
212 				syserr("Cannot dup to zero!");
213 				_exit(EX_OSERR);
214 			}
215 			close(pvect[0]);
216 			close(pvect[1]);
217 		}
218 		if (!flagset(M_RESTR, m->m_flags))
219 			setuid(getuid());
220 # ifdef LOG
221 		initlog(NULL, 0, LOG_CLOSE);
222 # endif LOG
223 # ifndef VFORK
224 		/*
225 		 * We have to be careful with vfork - we can't mung up the
226 		 * memory but we don't want the mailer to inherit any extra
227 		 * open files.  Chances are the mailer won't
228 		 * care about an extra file, but then again you never know.
229 		 * Actually, we would like to close(fileno(pwf)), but it's
230 		 * declared static so we can't.  But if we fclose(pwf), which
231 		 * is what endpwent does, it closes it in the parent too and
232 		 * the next getpwnam will be slower.  If you have a weird mailer
233 		 * that chokes on the extra file you should do the endpwent().
234 		 */
235 		endpwent();
236 # endif
237 		execv(m->m_mailer, pvp);
238 		/* syserr fails because log is closed */
239 		/* syserr("Cannot exec %s", m->m_mailer); */
240 		_exit(EX_UNAVAILABLE);
241 	}
242 
243 	/* arrange to write out header message if error */
244 	if (editfcn != NULL)
245 	{
246 		close(pvect[0]);
247 		signal(SIGPIPE, pipesig);
248 		mfile = fdopen(pvect[1], "w");
249 		(*editfcn)(mfile);
250 		fclose(mfile);
251 	}
252 
253 	/*
254 	**  Wait for child to die and report status.
255 	**	We should never get fatal errors (e.g., segmentation
256 	**	violation), so we report those specially.  For other
257 	**	errors, we choose a status message (into statmsg),
258 	**	and if it represents an error, we print it.
259 	*/
260 
261 	while ((i = wait(&st)) > 0 && i != pid)
262 		continue;
263 	if (i < 0)
264 	{
265 		syserr("wait");
266 		return (-1);
267 	}
268 	if ((st & 0377) != 0)
269 	{
270 		syserr("%s: stat %o", pvp[0], st);
271 		ExitStat = EX_UNAVAILABLE;
272 		return (-1);
273 	}
274 	i = (st >> 8) & 0377;
275 	giveresponse(i, FALSE, m);
276 	return (i);
277 }
278 /*
279 **  GIVERESPONSE -- Interpret an error response from a mailer
280 **
281 **	Parameters:
282 **		stat -- the status code from the mailer (high byte
283 **			only; core dumps must have been taken care of
284 **			already).
285 **		force -- if set, force an error message output, even
286 **			if the mailer seems to like to print its own
287 **			messages.
288 **		m -- the mailer descriptor for this mailer.
289 **
290 **	Returns:
291 **		none.
292 **
293 **	Side Effects:
294 **		Errors may be incremented.
295 **		ExitStat may be set.
296 **
297 **	Called By:
298 **		deliver
299 */
300 
301 giveresponse(stat, force, m)
302 	int stat;
303 	int force;
304 	register struct mailer *m;
305 {
306 	register char *statmsg;
307 	extern char *SysExMsg[];
308 	register int i;
309 	extern int N_SysEx;
310 
311 	i = stat - EX__BASE;
312 	if (i < 0 || i > N_SysEx)
313 		statmsg = NULL;
314 	else
315 		statmsg = SysExMsg[i];
316 	if (stat == 0)
317 		statmsg = "ok";
318 	else
319 	{
320 		Errors++;
321 		if (statmsg == NULL && m->m_badstat != 0)
322 		{
323 			stat = m->m_badstat;
324 			i = stat - EX__BASE;
325 # ifdef DEBUG
326 			if (i < 0 || i >= N_SysEx)
327 				syserr("Bad m_badstat %d", stat);
328 			else
329 # endif DEBUG
330 			statmsg = SysExMsg[i];
331 		}
332 		if (statmsg == NULL)
333 			usrerr("unknown mailer response %d", stat);
334 		else if (force || !flagset(M_QUIET, m->m_flags))
335 			usrerr("%s", statmsg);
336 	}
337 
338 	/*
339 	**  Final cleanup.
340 	**	Log a record of the transaction.  Compute the new
341 	**	ExitStat -- if we already had an error, stick with
342 	**	that.
343 	*/
344 
345 # ifdef LOG
346 	if (statmsg == NULL)
347 		logmsg(LOG_INFO, "%s->%s: error %d", From.q_paddr, To, stat);
348 	else
349 		logmsg(LOG_INFO, "%s->%s: %s", From.q_paddr, To, statmsg);
350 # endif LOG
351 	setstat(stat);
352 	return (stat);
353 }
354 /*
355 **  PUTHEADER -- insert the From header into some mail
356 **
357 **	For mailers such as 'msgs' that want the header inserted
358 **	into the mail, this edit filter inserts the From line and
359 **	then passes the rest of the message through.
360 **
361 **	Parameters:
362 **		fp -- the file pointer for the output.
363 **
364 **	Returns:
365 **		none
366 **
367 **	Side Effects:
368 **		Puts a "From" line in UNIX format, and then
369 **			outputs the rest of the message.
370 **
371 **	Called By:
372 **		deliver
373 */
374 
375 putheader(fp)
376 	register FILE *fp;
377 {
378 	char buf[MAXLINE + 1];
379 	long tim;
380 	extern char *ctime();
381 
382 	time(&tim);
383 	fprintf(fp, "From %s %s", From.q_paddr, ctime(&tim));
384 	while (fgets(buf, sizeof buf, stdin) != NULL && !ferror(fp))
385 		fputs(buf, fp);
386 	if (ferror(fp))
387 	{
388 		syserr("putheader: write error");
389 		setstat(EX_IOERR);
390 	}
391 }
392 /*
393 **  PIPESIG -- Handle broken pipe signals
394 **
395 **	This just logs an error.
396 **
397 **	Parameters:
398 **		none
399 **
400 **	Returns:
401 **		none
402 **
403 **	Side Effects:
404 **		logs an error message.
405 */
406 
407 pipesig()
408 {
409 	syserr("Broken pipe");
410 	signal(SIGPIPE, SIG_IGN);
411 }
412 /*
413 **  SENDTO -- Designate a send list.
414 **
415 **	The parameter is a comma-separated list of people to send to.
416 **	This routine arranges to send to all of them.
417 **
418 **	Parameters:
419 **		list -- the send list.
420 **		copyf -- the copy flag; passed to parse.
421 **
422 **	Returns:
423 **		none
424 **
425 **	Side Effects:
426 **		none.
427 **
428 **	Called By:
429 **		main
430 **		alias
431 */
432 
433 sendto(list, copyf)
434 	char *list;
435 	int copyf;
436 {
437 	register char *p;
438 	register char *q;
439 	register char c;
440 	addrq *a;
441 	extern addrq *parse();
442 	bool more;
443 
444 	/* more keeps track of what the previous delimiter was */
445 	more = TRUE;
446 	for (p = list; more; )
447 	{
448 		/* find the end of this address */
449 		q = p;
450 		while ((c = *p++) != '\0' && c != ',' && c != '\n')
451 			continue;
452 		more = c != '\0';
453 		*--p = '\0';
454 		if (more)
455 			p++;
456 
457 		/* parse the address */
458 		if ((a = parse(q, (addrq *) NULL, copyf)) == NULL)
459 			continue;
460 
461 		/* arrange to send to this person */
462 		recipient(a, &SendQ);
463 	}
464 	To = NULL;
465 }
466 /*
467 **  RECIPIENT -- Designate a message recipient
468 **
469 **	Saves the named person for future mailing.
470 **
471 **	Designates a person as a recipient.  This routine
472 **	does the initial parsing, and checks to see if
473 **	this person has already received the mail.
474 **	It also supresses local network names and turns them into
475 **	local names.
476 **
477 **	Parameters:
478 **		a -- the (preparsed) address header for the recipient.
479 **		targetq -- the queue to add the name to.
480 **
481 **	Returns:
482 **		none.
483 **
484 **	Side Effects:
485 **		none.
486 **
487 **	Called By:
488 **		sendto
489 **		main
490 */
491 
492 recipient(a, targetq)
493 	register addrq *a;
494 	addrq *targetq;
495 {
496 	register addrq *q;
497 	register struct mailer *m;
498 	register char **pvp;
499 	extern char *xalloc();
500 	extern bool forward();
501 	extern int errno;
502 	extern bool sameaddr();
503 
504 	To = a->q_paddr;
505 	m = a->q_mailer;
506 	errno = 0;
507 # ifdef DEBUG
508 	if (Debug)
509 		printf("recipient(%s)\n", To);
510 # endif DEBUG
511 
512 	/*
513 	**  Look up this person in the recipient list.  If they
514 	**  are there already, return, otherwise continue.
515 	*/
516 
517 	if (!ForceMail)
518 	{
519 		for (q = &SendQ; (q = nxtinq(q)) != NULL; )
520 			if (sameaddr(q, a, FALSE))
521 			{
522 # ifdef DEBUG
523 				if (Debug)
524 					printf("(%s in SendQ)\n", a->q_paddr);
525 # endif DEBUG
526 				return;
527 			}
528 		for (q = &AliasQ; (q = nxtinq(q)) != NULL; )
529 			if (sameaddr(q, a, FALSE))
530 			{
531 # ifdef DEBUG
532 				if (Debug)
533 					printf("(%s in AliasQ)\n", a->q_paddr);
534 # endif DEBUG
535 				return;
536 			}
537 	}
538 
539 	/*
540 	**  See if the user wants hir mail forwarded.
541 	**	`Forward' must do the forwarding recursively.
542 	*/
543 
544 	if (m == &Mailer[0] && !NoAlias && targetq == &SendQ && forward(a))
545 		return;
546 
547 	/*
548 	**  Put the user onto the target queue.
549 	*/
550 
551 	if (targetq != NULL)
552 	{
553 		putonq(a, targetq);
554 	}
555 
556 	return;
557 }
558 /*
559 **  BUILDARGV -- Build an argument vector for a mail server.
560 **
561 **	Using a template defined in config.c, an argv is built.
562 **	The format of the template is already a vector.  The
563 **	items of this vector are copied, unless a dollar sign
564 **	is encountered.  In this case, the next character
565 **	specifies something else to copy in.  These can be
566 **		$f	The from address.
567 **		$h	The host.
568 **		$u	The user.
569 **		$c	The hop count.
570 **	The vector is built in a local buffer.  A pointer to
571 **	the static argv is returned.
572 **
573 **	Parameters:
574 **		tmplt -- a template for an argument vector.
575 **		flags -- the flags for this server.
576 **		host -- the host name to send to.
577 **		user -- the user name to send to.
578 **		from -- the person this mail is from.
579 **
580 **	Returns:
581 **		A pointer to an argv.
582 **
583 **	Side Effects:
584 **		none
585 **
586 **	WARNING:
587 **		Since the argv is staticly allocated, any subsequent
588 **		calls will clobber the old argv.
589 **
590 **	Called By:
591 **		deliver
592 */
593 
594 char **
595 buildargv(tmplt, flags, host, user, from)
596 	char **tmplt;
597 	int flags;
598 	char *host;
599 	char *user;
600 	char *from;
601 {
602 	register char *p;
603 	register char *q;
604 	static char *pv[MAXPV+1];
605 	char **pvp;
606 	char **mvp;
607 	static char buf[512];
608 	register char *bp;
609 	char pbuf[30];
610 
611 	/*
612 	**  Do initial argv setup.
613 	**	Insert the mailer name.  Notice that $x expansion is
614 	**	NOT done on the mailer name.  Then, if the mailer has
615 	**	a picky -f flag, we insert it as appropriate.  This
616 	**	code does not check for 'pv' overflow; this places a
617 	**	manifest lower limit of 4 for MAXPV.
618 	*/
619 
620 	pvp = pv;
621 	bp = buf;
622 
623 	*pvp++ = tmplt[0];
624 
625 	/* insert -f or -r flag as appropriate */
626 	if (flagset(M_FOPT|M_ROPT, flags) && FromFlag)
627 	{
628 		if (flagset(M_FOPT, flags))
629 			*pvp++ = "-f";
630 		else
631 			*pvp++ = "-r";
632 		*pvp++ = From.q_paddr;
633 	}
634 
635 	/*
636 	**  Build the rest of argv.
637 	**	For each prototype parameter, the prototype is
638 	**	scanned character at a time.  If a dollar-sign is
639 	**	found, 'q' is set to the appropriate expansion,
640 	**	otherwise it is null.  Then either the string
641 	**	pointed to by q, or the original character, is
642 	**	interpolated into the buffer.  Buffer overflow is
643 	**	checked.
644 	*/
645 
646 	for (mvp = tmplt; (p = *++mvp) != NULL; )
647 	{
648 		if (pvp >= &pv[MAXPV])
649 		{
650 			syserr("Too many parameters to %s", pv[0]);
651 			return (NULL);
652 		}
653 		*pvp++ = bp;
654 		for (; *p != '\0'; p++)
655 		{
656 			/* q will be the interpolated quantity */
657 			q = NULL;
658 			if (*p == '$')
659 			{
660 				switch (*++p)
661 				{
662 				  case 'f':	/* from person */
663 					q = from;
664 					break;
665 
666 				  case 'u':	/* user */
667 					q = user;
668 					break;
669 
670 				  case 'h':	/* host */
671 					q = host;
672 					break;
673 
674 				  case 'c':	/* hop count */
675 					sprintf(pbuf, "%d", HopCount);
676 					q = pbuf;
677 					break;
678 				}
679 			}
680 
681 			/*
682 			**  Interpolate q or output one character
683 			**	Strip quote bits as we proceed.....
684 			*/
685 
686 			if (q != NULL)
687 			{
688 				while (bp < &buf[sizeof buf - 1] && (*bp++ = *q++) != '\0')
689 					continue;
690 				bp--;
691 			}
692 			else if (bp < &buf[sizeof buf - 1])
693 				*bp++ = *p;
694 		}
695 		*bp++ = '\0';
696 		if (bp >= &buf[sizeof buf - 1])
697 			return (NULL);
698 	}
699 	*pvp = NULL;
700 
701 # ifdef DEBUG
702 	if (Debug)
703 	{
704 		printf("Interpolated argv is:\n");
705 		for (mvp = pv; *mvp != NULL; mvp++)
706 			printf("\t%s\n", *mvp);
707 	}
708 # endif DEBUG
709 
710 	return (pv);
711 }
712 /*
713 **  MAILFILE -- Send a message to a file.
714 **
715 **	Parameters:
716 **		filename -- the name of the file to send to.
717 **
718 **	Returns:
719 **		The exit code associated with the operation.
720 **
721 **	Side Effects:
722 **		none.
723 **
724 **	Called By:
725 **		deliver
726 */
727 
728 mailfile(filename)
729 	char *filename;
730 {
731 	char buf[MAXLINE];
732 	register FILE *f;
733 	auto long tim;
734 	extern char *ctime();
735 
736 	f = fopen(filename, "a");
737 	if (f == NULL)
738 		return (EX_CANTCREAT);
739 
740 	/* output the timestamp */
741 	time(&tim);
742 	fprintf(f, "From %s %s", From.q_paddr, ctime(&tim));
743 	rewind(stdin);
744 	while (fgets(buf, sizeof buf, stdin) != NULL)
745 	{
746 		fputs(buf, f);
747 		if (ferror(f))
748 		{
749 			fclose(f);
750 			return (EX_IOERR);
751 		}
752 	}
753 	fputs("\n", f);
754 	fclose(f);
755 	return (EX_OK);
756 }
757