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 "sendmail.h"
10 
11 #ifndef lint
12 #ifdef SMTP
13 static char sccsid[] = "@(#)srvrsmtp.c	6.50 (Berkeley) 05/04/93 (with SMTP)";
14 #else
15 static char sccsid[] = "@(#)srvrsmtp.c	6.50 (Berkeley) 05/04/93 (without SMTP)";
16 #endif
17 #endif /* not lint */
18 
19 # include <errno.h>
20 # include <signal.h>
21 
22 # ifdef SMTP
23 
24 /*
25 **  SMTP -- run the SMTP protocol.
26 **
27 **	Parameters:
28 **		none.
29 **
30 **	Returns:
31 **		never.
32 **
33 **	Side Effects:
34 **		Reads commands from the input channel and processes
35 **			them.
36 */
37 
38 struct cmd
39 {
40 	char	*cmdname;	/* command name */
41 	int	cmdcode;	/* internal code, see below */
42 };
43 
44 /* values for cmdcode */
45 # define CMDERROR	0	/* bad command */
46 # define CMDMAIL	1	/* mail -- designate sender */
47 # define CMDRCPT	2	/* rcpt -- designate recipient */
48 # define CMDDATA	3	/* data -- send message text */
49 # define CMDRSET	4	/* rset -- reset state */
50 # define CMDVRFY	5	/* vrfy -- verify address */
51 # define CMDEXPN	6	/* expn -- expand address */
52 # define CMDNOOP	7	/* noop -- do nothing */
53 # define CMDQUIT	8	/* quit -- close connection and die */
54 # define CMDHELO	9	/* helo -- be polite */
55 # define CMDHELP	10	/* help -- give usage info */
56 # define CMDEHLO	11	/* ehlo -- extended helo (RFC 1425) */
57 /* non-standard commands */
58 # define CMDONEX	16	/* onex -- sending one transaction only */
59 # define CMDVERB	17	/* verb -- go into verbose mode */
60 /* debugging-only commands, only enabled if SMTPDEBUG is defined */
61 # define CMDDBGQSHOW	24	/* showq -- show send queue */
62 # define CMDDBGDEBUG	25	/* debug -- set debug mode */
63 
64 static struct cmd	CmdTab[] =
65 {
66 	"mail",		CMDMAIL,
67 	"rcpt",		CMDRCPT,
68 	"data",		CMDDATA,
69 	"rset",		CMDRSET,
70 	"vrfy",		CMDVRFY,
71 	"expn",		CMDEXPN,
72 	"help",		CMDHELP,
73 	"noop",		CMDNOOP,
74 	"quit",		CMDQUIT,
75 	"helo",		CMDHELO,
76 	"ehlo",		CMDEHLO,
77 	"verb",		CMDVERB,
78 	"onex",		CMDONEX,
79 	/*
80 	 * remaining commands are here only
81 	 * to trap and log attempts to use them
82 	 */
83 	"showq",	CMDDBGQSHOW,
84 	"debug",	CMDDBGDEBUG,
85 	NULL,		CMDERROR,
86 };
87 
88 bool	InChild = FALSE;		/* true if running in a subprocess */
89 bool	OneXact = FALSE;		/* one xaction only this run */
90 
91 #define EX_QUIT		22		/* special code for QUIT command */
92 
93 smtp(e)
94 	register ENVELOPE *e;
95 {
96 	register char *p;
97 	register struct cmd *c;
98 	char *cmd;
99 	static char *skipword();
100 	auto ADDRESS *vrfyqueue;
101 	ADDRESS *a;
102 	bool gotmail;			/* mail command received */
103 	bool gothello;			/* helo command received */
104 	bool vrfy;			/* set if this is a vrfy command */
105 	char *protocol;			/* sending protocol */
106 	char *sendinghost;		/* sending hostname */
107 	long msize;			/* approximate maximum message size */
108 	auto char *delimptr;
109 	char *id;
110 	char inp[MAXLINE];
111 	char cmdbuf[MAXLINE];
112 	extern char Version[];
113 	extern char *macvalue();
114 	extern ADDRESS *recipient();
115 	extern ENVELOPE BlankEnvelope;
116 	extern ENVELOPE *newenvelope();
117 	extern char *anynet_ntoa();
118 
119 	if (fileno(OutChannel) != fileno(stdout))
120 	{
121 		/* arrange for debugging output to go to remote host */
122 		(void) dup2(fileno(OutChannel), fileno(stdout));
123 	}
124 	settime(e);
125 	CurHostName = RealHostName;
126 	setproctitle("srvrsmtp %s startup", CurHostName);
127 	expand("\201e", inp, &inp[sizeof inp], e);
128 	message("220 %s", inp);
129 	protocol = NULL;
130 	sendinghost = macvalue('s', e);
131 	gothello = FALSE;
132 	gotmail = FALSE;
133 	for (;;)
134 	{
135 		/* arrange for backout */
136 		if (setjmp(TopFrame) > 0 && InChild)
137 		{
138 			QuickAbort = FALSE;
139 			SuprErrs = TRUE;
140 			finis();
141 		}
142 		QuickAbort = FALSE;
143 		HoldErrs = FALSE;
144 		LogUsrErrs = FALSE;
145 		e->e_flags &= ~EF_VRFYONLY;
146 
147 		/* setup for the read */
148 		e->e_to = NULL;
149 		Errors = 0;
150 		(void) fflush(stdout);
151 
152 		/* read the input line */
153 		SmtpPhase = "srvrsmtp cmd read";
154 		setproctitle("srvrsmtp %s cmd read", CurHostName);
155 		p = sfgets(inp, sizeof inp, InChannel, TimeOuts.to_nextcommand);
156 
157 		/* handle errors */
158 		if (p == NULL)
159 		{
160 			/* end of file, just die */
161 			message("421 %s Lost input channel from %s",
162 				MyHostName, CurHostName);
163 #ifdef LOG
164 			if (LogLevel > 1)
165 				syslog(LOG_NOTICE, "lost input channel from %s",
166 					CurHostName);
167 #endif
168 			if (InChild)
169 				ExitStat = EX_QUIT;
170 			finis();
171 		}
172 
173 		/* clean up end of line */
174 		fixcrlf(inp, TRUE);
175 
176 		/* echo command to transcript */
177 		if (e->e_xfp != NULL)
178 			fprintf(e->e_xfp, "<<< %s\n", inp);
179 
180 		if (e->e_id == NULL)
181 			setproctitle("%s: %s", CurHostName, inp);
182 		else
183 			setproctitle("%s %s: %s", e->e_id, CurHostName, inp);
184 
185 		/* break off command */
186 		for (p = inp; isascii(*p) && isspace(*p); p++)
187 			continue;
188 		cmd = cmdbuf;
189 		while (*p != '\0' &&
190 		       !(isascii(*p) && isspace(*p)) &&
191 		       cmd < &cmdbuf[sizeof cmdbuf - 2])
192 			*cmd++ = *p++;
193 		*cmd = '\0';
194 
195 		/* throw away leading whitespace */
196 		while (isascii(*p) && isspace(*p))
197 			p++;
198 
199 		/* decode command */
200 		for (c = CmdTab; c->cmdname != NULL; c++)
201 		{
202 			if (!strcasecmp(c->cmdname, cmdbuf))
203 				break;
204 		}
205 
206 		/* reset errors */
207 		errno = 0;
208 
209 		/* process command */
210 		switch (c->cmdcode)
211 		{
212 		  case CMDHELO:		/* hello -- introduce yourself */
213 		  case CMDEHLO:		/* extended hello */
214 			if (c->cmdcode == CMDEHLO)
215 			{
216 				protocol = "ESMTP";
217 				SmtpPhase = "EHLO";
218 			}
219 			else
220 			{
221 				protocol = "SMTP";
222 				SmtpPhase = "HELO";
223 			}
224 			sendinghost = newstr(p);
225 			if (strcasecmp(p, RealHostName) != 0)
226 			{
227 				auth_warning(e, "Host %s claimed to be %s",
228 					RealHostName, p);
229 			}
230 			p = macvalue('_', e);
231 			if (p == NULL)
232 				p = RealHostName;
233 
234 			/* send ext. message -- old systems must ignore */
235 			message("250-%s Hello %s, pleased to meet you",
236 				MyHostName, p);
237 			if (!bitset(PRIV_NOEXPN, PrivacyFlags))
238 				message("250-EXPN");
239 			if (MaxMessageSize > 0)
240 				message("250-SIZE %ld", MaxMessageSize);
241 			else
242 				message("250-SIZE");
243 			message("250 HELP");
244 			gothello = TRUE;
245 			break;
246 
247 		  case CMDMAIL:		/* mail -- designate sender */
248 			SmtpPhase = "MAIL";
249 
250 			/* check for validity of this command */
251 			if (!gothello)
252 			{
253 				/* set sending host to our known value */
254 				if (sendinghost == NULL)
255 					sendinghost = RealHostName;
256 
257 				if (bitset(PRIV_NEEDMAILHELO, PrivacyFlags))
258 				{
259 					message("503 Polite people say HELO first");
260 					break;
261 				}
262 				else
263 				{
264 					auth_warning(e,
265 						"Host %s didn't use HELO protocol",
266 						RealHostName);
267 				}
268 			}
269 			if (gotmail)
270 			{
271 				message("503 Sender already specified");
272 				break;
273 			}
274 			if (InChild)
275 			{
276 				errno = 0;
277 				syserr("503 Nested MAIL command: MAIL %s", p);
278 				finis();
279 			}
280 
281 			/* fork a subprocess to process this command */
282 			if (runinchild("SMTP-MAIL", e) > 0)
283 				break;
284 			if (protocol == NULL)
285 				protocol = "SMTP";
286 			define('r', protocol, e);
287 			define('s', sendinghost, e);
288 			initsys(e);
289 			setproctitle("%s %s: %s", e->e_id, CurHostName, inp);
290 
291 			/* child -- go do the processing */
292 			p = skipword(p, "from");
293 			if (p == NULL)
294 				break;
295 			if (setjmp(TopFrame) > 0)
296 			{
297 				/* this failed -- undo work */
298 				if (InChild)
299 				{
300 					QuickAbort = FALSE;
301 					SuprErrs = TRUE;
302 					finis();
303 				}
304 				break;
305 			}
306 			QuickAbort = TRUE;
307 
308 			/* must parse sender first */
309 			delimptr = NULL;
310 			setsender(p, e, &delimptr, FALSE);
311 			p = delimptr;
312 			if (p != NULL && *p != '\0')
313 				*p++ = '\0';
314 
315 			/* now parse ESMTP arguments */
316 			msize = 0;
317 			for (; p != NULL && *p != '\0'; p++)
318 			{
319 				char *kp;
320 				char *vp;
321 
322 				/* locate the beginning of the keyword */
323 				while (isascii(*p) && isspace(*p))
324 					p++;
325 				if (*p == '\0')
326 					break;
327 				kp = p;
328 
329 				/* skip to the value portion */
330 				while (isascii(*p) && isalnum(*p) || *p == '-')
331 					p++;
332 				if (*p == '=')
333 				{
334 					*p++ = '\0';
335 					vp = p;
336 
337 					/* skip to the end of the value */
338 					while (*p != '\0' && *p != ' ' &&
339 					       !(isascii(*p) && iscntrl(*p)) &&
340 					       *p != '=')
341 						p++;
342 				}
343 
344 				if (*p != '\0')
345 					*p++ = '\0';
346 
347 				if (tTd(19, 1))
348 					printf("MAIL: got arg %s=%s\n", kp,
349 						vp == NULL ? "<null>" : vp);
350 
351 				if (strcasecmp(kp, "size") == 0)
352 				{
353 					if (vp == NULL)
354 					{
355 						usrerr("501 SIZE requires a value");
356 						/* NOTREACHED */
357 					}
358 					msize = atol(vp);
359 				}
360 				else if (strcasecmp(kp, "body") == 0)
361 				{
362 					if (vp == NULL)
363 					{
364 						usrerr("501 BODY requires a value");
365 						/* NOTREACHED */
366 					}
367 # ifdef MIME
368 					if (strcasecmp(vp, "8bitmime") == 0)
369 					{
370 						e->e_bodytype = "8BITMIME";
371 						SevenBit = FALSE;
372 					}
373 					else if (strcasecmp(vp, "7bit") == 0)
374 					{
375 						e->e_bodytype = "7BIT";
376 						SevenBit = TRUE;
377 					}
378 					else
379 					{
380 						usrerr("501 Unknown BODY type %s",
381 							vp);
382 					}
383 # endif
384 				}
385 				else
386 				{
387 					usrerr("501 %s parameter unrecognized", kp);
388 					/* NOTREACHED */
389 				}
390 			}
391 
392 			if (MaxMessageSize > 0 && msize > MaxMessageSize)
393 			{
394 				usrerr("552 Message size exceeds fixed maximum message size (%ld)",
395 					MaxMessageSize);
396 				/* NOTREACHED */
397 			}
398 
399 			if (!enoughspace(msize))
400 			{
401 				message("452 Insufficient disk space; try again later");
402 				break;
403 			}
404 			message("250 Sender ok");
405 			gotmail = TRUE;
406 			break;
407 
408 		  case CMDRCPT:		/* rcpt -- designate recipient */
409 			if (!gotmail)
410 			{
411 				usrerr("503 Need MAIL before RCPT");
412 				break;
413 			}
414 			SmtpPhase = "RCPT";
415 			if (setjmp(TopFrame) > 0)
416 			{
417 				e->e_flags &= ~EF_FATALERRS;
418 				break;
419 			}
420 			QuickAbort = TRUE;
421 			LogUsrErrs = TRUE;
422 
423 			if (e->e_sendmode != SM_DELIVER)
424 				e->e_flags |= EF_VRFYONLY;
425 
426 			p = skipword(p, "to");
427 			if (p == NULL)
428 				break;
429 			a = parseaddr(p, (ADDRESS *) NULL, 1, ' ', NULL, e);
430 			if (a == NULL)
431 				break;
432 			a->q_flags |= QPRIMARY;
433 			a = recipient(a, &e->e_sendqueue, e);
434 			if (Errors != 0)
435 				break;
436 
437 			/* no errors during parsing, but might be a duplicate */
438 			e->e_to = p;
439 			if (!bitset(QBADADDR, a->q_flags))
440 				message("250 Recipient ok");
441 			else
442 			{
443 				/* punt -- should keep message in ADDRESS.... */
444 				message("550 Addressee unknown");
445 			}
446 			e->e_to = NULL;
447 			break;
448 
449 		  case CMDDATA:		/* data -- text of mail */
450 			SmtpPhase = "DATA";
451 			if (!gotmail)
452 			{
453 				message("503 Need MAIL command");
454 				break;
455 			}
456 			else if (e->e_nrcpts <= 0)
457 			{
458 				message("503 Need RCPT (recipient)");
459 				break;
460 			}
461 
462 			/* check to see if we need to re-expand aliases */
463 			for (a = e->e_sendqueue; a != NULL; a = a->q_next)
464 			{
465 				if (bitset(QVERIFIED, a->q_flags))
466 					break;
467 			}
468 
469 			/* collect the text of the message */
470 			SmtpPhase = "collect";
471 			collect(TRUE, a != NULL, e);
472 			e->e_flags &= ~EF_FATALERRS;
473 			if (Errors != 0)
474 				break;
475 
476 			/*
477 			**  Arrange to send to everyone.
478 			**	If sending to multiple people, mail back
479 			**		errors rather than reporting directly.
480 			**	In any case, don't mail back errors for
481 			**		anything that has happened up to
482 			**		now (the other end will do this).
483 			**	Truncate our transcript -- the mail has gotten
484 			**		to us successfully, and if we have
485 			**		to mail this back, it will be easier
486 			**		on the reader.
487 			**	Then send to everyone.
488 			**	Finally give a reply code.  If an error has
489 			**		already been given, don't mail a
490 			**		message back.
491 			**	We goose error returns by clearing error bit.
492 			*/
493 
494 			SmtpPhase = "delivery";
495 			if (e->e_nrcpts != 1)
496 			{
497 				HoldErrs = TRUE;
498 				e->e_errormode = EM_MAIL;
499 			}
500 			e->e_xfp = freopen(queuename(e, 'x'), "w", e->e_xfp);
501 			id = e->e_id;
502 
503 			/* send to all recipients */
504 			sendall(e, a == NULL ? SM_DEFAULT : SM_QUEUE);
505 			e->e_to = NULL;
506 
507 			/* save statistics */
508 			markstats(e, (ADDRESS *) NULL);
509 
510 			/* issue success if appropriate and reset */
511 			if (Errors == 0 || HoldErrs)
512 				message("250 %s Message accepted for delivery", id);
513 			if (bitset(EF_FATALERRS, e->e_flags))
514 			{
515 				/* avoid sending back an extra message */
516 				e->e_flags &= ~EF_FATALERRS;
517 			}
518 			else
519 			{
520 				/* if we just queued, poke it */
521 				if (a != NULL && e->e_sendmode != SM_QUEUE)
522 				{
523 					unlockqueue(e);
524 					dowork(id, TRUE, TRUE, e);
525 					e->e_id = NULL;
526 				}
527 			}
528 
529 			/* if in a child, pop back to our parent */
530 			if (InChild)
531 				finis();
532 
533 			/* clean up a bit */
534 			gotmail = FALSE;
535 			dropenvelope(e);
536 			CurEnv = e = newenvelope(e, CurEnv);
537 			e->e_flags = BlankEnvelope.e_flags;
538 			break;
539 
540 		  case CMDRSET:		/* rset -- reset state */
541 			message("250 Reset state");
542 			if (InChild)
543 				finis();
544 
545 			/* clean up a bit */
546 			gotmail = FALSE;
547 			dropenvelope(e);
548 			CurEnv = e = newenvelope(e, CurEnv);
549 			break;
550 
551 		  case CMDVRFY:		/* vrfy -- verify address */
552 		  case CMDEXPN:		/* expn -- expand address */
553 			vrfy = c->cmdcode == CMDVRFY;
554 			if (bitset(vrfy ? PRIV_NOVRFY : PRIV_NOEXPN,
555 						PrivacyFlags))
556 			{
557 				if (vrfy)
558 					message("252 Who's to say?");
559 				else
560 					message("502 That's none of your business");
561 				break;
562 			}
563 			else if (!gothello &&
564 				 bitset(vrfy ? PRIV_NEEDVRFYHELO : PRIV_NEEDEXPNHELO,
565 						PrivacyFlags))
566 			{
567 				message("503 I demand that you introduce yourself first");
568 				break;
569 			}
570 			if (runinchild(vrfy ? "SMTP-VRFY" : "SMTP-EXPN", e) > 0)
571 				break;
572 #ifdef LOG
573 			if (LogLevel > 5)
574 				syslog(LOG_INFO, "%s: %s", CurHostName, inp);
575 #endif
576 			vrfyqueue = NULL;
577 			QuickAbort = TRUE;
578 			if (vrfy)
579 				e->e_flags |= EF_VRFYONLY;
580 			(void) sendtolist(p, (ADDRESS *) NULL, &vrfyqueue, e);
581 			if (Errors != 0)
582 			{
583 				if (InChild)
584 					finis();
585 				break;
586 			}
587 			while (vrfyqueue != NULL)
588 			{
589 				register ADDRESS *a = vrfyqueue->q_next;
590 				char *code;
591 
592 				while (a != NULL && bitset(QDONTSEND|QBADADDR, a->q_flags))
593 					a = a->q_next;
594 
595 				if (!bitset(QDONTSEND|QBADADDR, vrfyqueue->q_flags))
596 					printvrfyaddr(vrfyqueue, a == NULL);
597 				else if (a == NULL)
598 					message("554 Self destructive alias loop");
599 				vrfyqueue = a;
600 			}
601 			if (InChild)
602 				finis();
603 			break;
604 
605 		  case CMDHELP:		/* help -- give user info */
606 			help(p);
607 			break;
608 
609 		  case CMDNOOP:		/* noop -- do nothing */
610 			message("200 OK");
611 			break;
612 
613 		  case CMDQUIT:		/* quit -- leave mail */
614 			message("221 %s closing connection", MyHostName);
615 			if (InChild)
616 				ExitStat = EX_QUIT;
617 			finis();
618 
619 		  case CMDVERB:		/* set verbose mode */
620 			Verbose = TRUE;
621 			e->e_sendmode = SM_DELIVER;
622 			message("200 Verbose mode");
623 			break;
624 
625 		  case CMDONEX:		/* doing one transaction only */
626 			OneXact = TRUE;
627 			message("200 Only one transaction");
628 			break;
629 
630 # ifdef SMTPDEBUG
631 		  case CMDDBGQSHOW:	/* show queues */
632 			printf("Send Queue=");
633 			printaddr(e->e_sendqueue, TRUE);
634 			break;
635 
636 		  case CMDDBGDEBUG:	/* set debug mode */
637 			tTsetup(tTdvect, sizeof tTdvect, "0-99.1");
638 			tTflag(p);
639 			message("200 Debug set");
640 			break;
641 
642 # else /* not SMTPDEBUG */
643 
644 		  case CMDDBGQSHOW:	/* show queues */
645 		  case CMDDBGDEBUG:	/* set debug mode */
646 # ifdef LOG
647 			if (LogLevel > 0)
648 				syslog(LOG_NOTICE,
649 				    "\"%s\" command from %s (%s)",
650 				    c->cmdname, RealHostName,
651 				    anynet_ntoa(&RealHostAddr));
652 # endif
653 			/* FALL THROUGH */
654 # endif /* SMTPDEBUG */
655 
656 		  case CMDERROR:	/* unknown command */
657 			message("500 Command unrecognized");
658 			break;
659 
660 		  default:
661 			errno = 0;
662 			syserr("500 smtp: unknown code %d", c->cmdcode);
663 			break;
664 		}
665 	}
666 }
667 /*
668 **  SKIPWORD -- skip a fixed word.
669 **
670 **	Parameters:
671 **		p -- place to start looking.
672 **		w -- word to skip.
673 **
674 **	Returns:
675 **		p following w.
676 **		NULL on error.
677 **
678 **	Side Effects:
679 **		clobbers the p data area.
680 */
681 
682 static char *
683 skipword(p, w)
684 	register char *p;
685 	char *w;
686 {
687 	register char *q;
688 
689 	/* find beginning of word */
690 	while (isascii(*p) && isspace(*p))
691 		p++;
692 	q = p;
693 
694 	/* find end of word */
695 	while (*p != '\0' && *p != ':' && !(isascii(*p) && isspace(*p)))
696 		p++;
697 	while (isascii(*p) && isspace(*p))
698 		*p++ = '\0';
699 	if (*p != ':')
700 	{
701 	  syntax:
702 		message("501 Syntax error");
703 		Errors++;
704 		return (NULL);
705 	}
706 	*p++ = '\0';
707 	while (isascii(*p) && isspace(*p))
708 		p++;
709 
710 	/* see if the input word matches desired word */
711 	if (strcasecmp(q, w))
712 		goto syntax;
713 
714 	return (p);
715 }
716 /*
717 **  PRINTVRFYADDR -- print an entry in the verify queue
718 **
719 **	Parameters:
720 **		a -- the address to print
721 **		last -- set if this is the last one.
722 **
723 **	Returns:
724 **		none.
725 **
726 **	Side Effects:
727 **		Prints the appropriate 250 codes.
728 */
729 
730 printvrfyaddr(a, last)
731 	register ADDRESS *a;
732 	bool last;
733 {
734 	char fmtbuf[20];
735 
736 	strcpy(fmtbuf, "250");
737 	fmtbuf[3] = last ? ' ' : '-';
738 
739 	if (strchr(a->q_paddr, '<') != NULL)
740 		strcpy(&fmtbuf[4], "%s");
741 	else if (a->q_fullname == NULL)
742 		strcpy(&fmtbuf[4], "<%s>");
743 	else
744 	{
745 		strcpy(&fmtbuf[4], "%s <%s>");
746 		message(fmtbuf, a->q_fullname, a->q_paddr);
747 		return;
748 	}
749 	message(fmtbuf, a->q_paddr);
750 }
751 /*
752 **  HELP -- implement the HELP command.
753 **
754 **	Parameters:
755 **		topic -- the topic we want help for.
756 **
757 **	Returns:
758 **		none.
759 **
760 **	Side Effects:
761 **		outputs the help file to message output.
762 */
763 
764 help(topic)
765 	char *topic;
766 {
767 	register FILE *hf;
768 	int len;
769 	char buf[MAXLINE];
770 	bool noinfo;
771 
772 	if (HelpFile == NULL || (hf = fopen(HelpFile, "r")) == NULL)
773 	{
774 		/* no help */
775 		errno = 0;
776 		message("502 HELP not implemented");
777 		return;
778 	}
779 
780 	if (topic == NULL || *topic == '\0')
781 		topic = "smtp";
782 	else
783 		makelower(topic);
784 
785 	len = strlen(topic);
786 	noinfo = TRUE;
787 
788 	while (fgets(buf, sizeof buf, hf) != NULL)
789 	{
790 		if (strncmp(buf, topic, len) == 0)
791 		{
792 			register char *p;
793 
794 			p = strchr(buf, '\t');
795 			if (p == NULL)
796 				p = buf;
797 			else
798 				p++;
799 			fixcrlf(p, TRUE);
800 			message("214-%s", p);
801 			noinfo = FALSE;
802 		}
803 	}
804 
805 	if (noinfo)
806 		message("504 HELP topic unknown");
807 	else
808 		message("214 End of HELP info");
809 	(void) fclose(hf);
810 }
811 /*
812 **  RUNINCHILD -- return twice -- once in the child, then in the parent again
813 **
814 **	Parameters:
815 **		label -- a string used in error messages
816 **
817 **	Returns:
818 **		zero in the child
819 **		one in the parent
820 **
821 **	Side Effects:
822 **		none.
823 */
824 
825 runinchild(label, e)
826 	char *label;
827 	register ENVELOPE *e;
828 {
829 	int childpid;
830 
831 	if (!OneXact)
832 	{
833 		childpid = dofork();
834 		if (childpid < 0)
835 		{
836 			syserr("%s: cannot fork", label);
837 			return (1);
838 		}
839 		if (childpid > 0)
840 		{
841 			auto int st;
842 
843 			/* parent -- wait for child to complete */
844 			setproctitle("srvrsmtp %s child wait", CurHostName);
845 			st = waitfor(childpid);
846 			if (st == -1)
847 				syserr("%s: lost child", label);
848 
849 			/* if we exited on a QUIT command, complete the process */
850 			if (st == (EX_QUIT << 8))
851 				finis();
852 
853 			return (1);
854 		}
855 		else
856 		{
857 			/* child */
858 			InChild = TRUE;
859 			QuickAbort = FALSE;
860 			clearenvelope(e, FALSE);
861 		}
862 	}
863 
864 	/* open alias database */
865 	initaliases(FALSE, e);
866 
867 	return (0);
868 }
869 
870 # endif /* SMTP */
871