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	6.54 (Berkeley) 05/21/93 (with SMTP)";
14 #else
15 static char sccsid[] = "@(#)srvrsmtp.c	6.54 (Berkeley) 05/21/93 (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 	int nrcpts;			/* number of RCPT commands */
111 	char inp[MAXLINE];
112 	char cmdbuf[MAXLINE];
113 	extern char Version[];
114 	extern char *macvalue();
115 	extern ADDRESS *recipient();
116 	extern ENVELOPE BlankEnvelope;
117 	extern ENVELOPE *newenvelope();
118 	extern char *anynet_ntoa();
119 
120 	if (fileno(OutChannel) != fileno(stdout))
121 	{
122 		/* arrange for debugging output to go to remote host */
123 		(void) dup2(fileno(OutChannel), fileno(stdout));
124 	}
125 	settime(e);
126 	CurHostName = RealHostName;
127 	setproctitle("srvrsmtp %s startup", CurHostName);
128 	expand("\201e", inp, &inp[sizeof inp], e);
129 	message("220-%s", inp);
130 	message("220 ESMTP spoken here");
131 	protocol = NULL;
132 	sendinghost = macvalue('s', e);
133 	gothello = FALSE;
134 	gotmail = FALSE;
135 	for (;;)
136 	{
137 		/* arrange for backout */
138 		if (setjmp(TopFrame) > 0 && InChild)
139 		{
140 			QuickAbort = FALSE;
141 			SuprErrs = TRUE;
142 			finis();
143 		}
144 		QuickAbort = FALSE;
145 		HoldErrs = FALSE;
146 		LogUsrErrs = FALSE;
147 		e->e_flags &= ~EF_VRFYONLY;
148 
149 		/* setup for the read */
150 		e->e_to = NULL;
151 		Errors = 0;
152 		(void) fflush(stdout);
153 
154 		/* read the input line */
155 		SmtpPhase = "srvrsmtp cmd read";
156 		setproctitle("srvrsmtp %s cmd read", CurHostName);
157 		p = sfgets(inp, sizeof inp, InChannel, TimeOuts.to_nextcommand);
158 
159 		/* handle errors */
160 		if (p == NULL)
161 		{
162 			/* end of file, just die */
163 			message("421 %s Lost input channel from %s",
164 				MyHostName, CurHostName);
165 #ifdef LOG
166 			if (LogLevel > 1)
167 				syslog(LOG_NOTICE, "lost input channel from %s",
168 					CurHostName);
169 #endif
170 			if (InChild)
171 				ExitStat = EX_QUIT;
172 			finis();
173 		}
174 
175 		/* clean up end of line */
176 		fixcrlf(inp, TRUE);
177 
178 		/* echo command to transcript */
179 		if (e->e_xfp != NULL)
180 			fprintf(e->e_xfp, "<<< %s\n", inp);
181 
182 		if (e->e_id == NULL)
183 			setproctitle("%s: %s", CurHostName, inp);
184 		else
185 			setproctitle("%s %s: %s", e->e_id, CurHostName, inp);
186 
187 		/* break off command */
188 		for (p = inp; isascii(*p) && isspace(*p); p++)
189 			continue;
190 		cmd = cmdbuf;
191 		while (*p != '\0' &&
192 		       !(isascii(*p) && isspace(*p)) &&
193 		       cmd < &cmdbuf[sizeof cmdbuf - 2])
194 			*cmd++ = *p++;
195 		*cmd = '\0';
196 
197 		/* throw away leading whitespace */
198 		while (isascii(*p) && isspace(*p))
199 			p++;
200 
201 		/* decode command */
202 		for (c = CmdTab; c->cmdname != NULL; c++)
203 		{
204 			if (!strcasecmp(c->cmdname, cmdbuf))
205 				break;
206 		}
207 
208 		/* reset errors */
209 		errno = 0;
210 
211 		/* process command */
212 		switch (c->cmdcode)
213 		{
214 		  case CMDHELO:		/* hello -- introduce yourself */
215 		  case CMDEHLO:		/* extended hello */
216 			if (c->cmdcode == CMDEHLO)
217 			{
218 				protocol = "ESMTP";
219 				SmtpPhase = "EHLO";
220 			}
221 			else
222 			{
223 				protocol = "SMTP";
224 				SmtpPhase = "HELO";
225 			}
226 			sendinghost = newstr(p);
227 			if (strcasecmp(p, RealHostName) != 0)
228 			{
229 				auth_warning(e, "Host %s claimed to be %s",
230 					RealHostName, p);
231 			}
232 			p = macvalue('_', e);
233 			if (p == NULL)
234 				p = RealHostName;
235 
236 			/* send ext. message -- old systems must ignore */
237 			message("250%c%s Hello %s, pleased to meet you",
238 				c->cmdcode == CMDEHLO ? '-' : ' ',
239 				MyHostName, p);
240 			gothello = TRUE;
241 			if (c->cmdcode != CMDEHLO)
242 				break;
243 			if (!bitset(PRIV_NOEXPN, PrivacyFlags))
244 				message("250-EXPN");
245 			if (MaxMessageSize > 0)
246 				message("250-SIZE %ld", MaxMessageSize);
247 			else
248 				message("250-SIZE");
249 			message("250 HELP");
250 			break;
251 
252 		  case CMDMAIL:		/* mail -- designate sender */
253 			SmtpPhase = "MAIL";
254 
255 			/* check for validity of this command */
256 			if (!gothello)
257 			{
258 				/* set sending host to our known value */
259 				if (sendinghost == NULL)
260 					sendinghost = RealHostName;
261 
262 				if (bitset(PRIV_NEEDMAILHELO, PrivacyFlags))
263 				{
264 					message("503 Polite people say HELO first");
265 					break;
266 				}
267 				else
268 				{
269 					auth_warning(e,
270 						"Host %s didn't use HELO protocol",
271 						RealHostName);
272 				}
273 			}
274 			if (gotmail)
275 			{
276 				message("503 Sender already specified");
277 				break;
278 			}
279 			if (InChild)
280 			{
281 				errno = 0;
282 				syserr("503 Nested MAIL command: MAIL %s", p);
283 				finis();
284 			}
285 
286 			/* fork a subprocess to process this command */
287 			if (runinchild("SMTP-MAIL", e) > 0)
288 				break;
289 			if (protocol == NULL)
290 				protocol = "SMTP";
291 			define('r', protocol, e);
292 			define('s', sendinghost, e);
293 			initsys(e);
294 			nrcpts = 0;
295 			setproctitle("%s %s: %s", e->e_id, CurHostName, inp);
296 
297 			/* child -- go do the processing */
298 			p = skipword(p, "from");
299 			if (p == NULL)
300 				break;
301 			if (setjmp(TopFrame) > 0)
302 			{
303 				/* this failed -- undo work */
304 				if (InChild)
305 				{
306 					QuickAbort = FALSE;
307 					SuprErrs = TRUE;
308 					finis();
309 				}
310 				break;
311 			}
312 			QuickAbort = TRUE;
313 
314 			/* must parse sender first */
315 			delimptr = NULL;
316 			setsender(p, e, &delimptr, FALSE);
317 			p = delimptr;
318 			if (p != NULL && *p != '\0')
319 				*p++ = '\0';
320 
321 			/* now parse ESMTP arguments */
322 			msize = 0;
323 			for (; p != NULL && *p != '\0'; p++)
324 			{
325 				char *kp;
326 				char *vp;
327 
328 				/* locate the beginning of the keyword */
329 				while (isascii(*p) && isspace(*p))
330 					p++;
331 				if (*p == '\0')
332 					break;
333 				kp = p;
334 
335 				/* skip to the value portion */
336 				while (isascii(*p) && isalnum(*p) || *p == '-')
337 					p++;
338 				if (*p == '=')
339 				{
340 					*p++ = '\0';
341 					vp = p;
342 
343 					/* skip to the end of the value */
344 					while (*p != '\0' && *p != ' ' &&
345 					       !(isascii(*p) && iscntrl(*p)) &&
346 					       *p != '=')
347 						p++;
348 				}
349 
350 				if (*p != '\0')
351 					*p++ = '\0';
352 
353 				if (tTd(19, 1))
354 					printf("MAIL: got arg %s=%s\n", kp,
355 						vp == NULL ? "<null>" : vp);
356 
357 				if (strcasecmp(kp, "size") == 0)
358 				{
359 					if (vp == NULL)
360 					{
361 						usrerr("501 SIZE requires a value");
362 						/* NOTREACHED */
363 					}
364 					msize = atol(vp);
365 				}
366 				else if (strcasecmp(kp, "body") == 0)
367 				{
368 					if (vp == NULL)
369 					{
370 						usrerr("501 BODY requires a value");
371 						/* NOTREACHED */
372 					}
373 # ifdef MIME
374 					if (strcasecmp(vp, "8bitmime") == 0)
375 					{
376 						e->e_bodytype = "8BITMIME";
377 						SevenBit = FALSE;
378 					}
379 					else if (strcasecmp(vp, "7bit") == 0)
380 					{
381 						e->e_bodytype = "7BIT";
382 						SevenBit = TRUE;
383 					}
384 					else
385 					{
386 						usrerr("501 Unknown BODY type %s",
387 							vp);
388 					}
389 # endif
390 				}
391 				else
392 				{
393 					usrerr("501 %s parameter unrecognized", kp);
394 					/* NOTREACHED */
395 				}
396 			}
397 
398 			if (MaxMessageSize > 0 && msize > MaxMessageSize)
399 			{
400 				usrerr("552 Message size exceeds fixed maximum message size (%ld)",
401 					MaxMessageSize);
402 				/* NOTREACHED */
403 			}
404 
405 			if (!enoughspace(msize))
406 			{
407 				message("452 Insufficient disk space; try again later");
408 				break;
409 			}
410 			message("250 Sender ok");
411 			gotmail = TRUE;
412 			break;
413 
414 		  case CMDRCPT:		/* rcpt -- designate recipient */
415 			if (!gotmail)
416 			{
417 				usrerr("503 Need MAIL before RCPT");
418 				break;
419 			}
420 			SmtpPhase = "RCPT";
421 			if (setjmp(TopFrame) > 0)
422 			{
423 				e->e_flags &= ~EF_FATALERRS;
424 				break;
425 			}
426 			QuickAbort = TRUE;
427 			LogUsrErrs = TRUE;
428 
429 			if (e->e_sendmode != SM_DELIVER)
430 				e->e_flags |= EF_VRFYONLY;
431 
432 			p = skipword(p, "to");
433 			if (p == NULL)
434 				break;
435 			a = parseaddr(p, (ADDRESS *) NULL, 1, ' ', NULL, e);
436 			if (a == NULL)
437 				break;
438 			a->q_flags |= QPRIMARY;
439 			a = recipient(a, &e->e_sendqueue, e);
440 			if (Errors != 0)
441 				break;
442 
443 			/* no errors during parsing, but might be a duplicate */
444 			e->e_to = p;
445 			if (!bitset(QBADADDR, a->q_flags))
446 			{
447 				message("250 Recipient ok");
448 				nrcpts++;
449 			}
450 			else
451 			{
452 				/* punt -- should keep message in ADDRESS.... */
453 				message("550 Addressee unknown");
454 			}
455 			e->e_to = NULL;
456 			break;
457 
458 		  case CMDDATA:		/* data -- text of mail */
459 			SmtpPhase = "DATA";
460 			if (!gotmail)
461 			{
462 				message("503 Need MAIL command");
463 				break;
464 			}
465 			else if (e->e_nrcpts <= 0)
466 			{
467 				message("503 Need RCPT (recipient)");
468 				break;
469 			}
470 
471 			/* check to see if we need to re-expand aliases */
472 			for (a = e->e_sendqueue; a != NULL; a = a->q_next)
473 			{
474 				if (bitset(QVERIFIED, a->q_flags))
475 					break;
476 			}
477 
478 			/* collect the text of the message */
479 			SmtpPhase = "collect";
480 			collect(TRUE, a != NULL, e);
481 			e->e_flags &= ~EF_FATALERRS;
482 			if (Errors != 0)
483 				goto abortmessage;
484 
485 			/*
486 			**  Arrange to send to everyone.
487 			**	If sending to multiple people, mail back
488 			**		errors rather than reporting directly.
489 			**	In any case, don't mail back errors for
490 			**		anything that has happened up to
491 			**		now (the other end will do this).
492 			**	Truncate our transcript -- the mail has gotten
493 			**		to us successfully, and if we have
494 			**		to mail this back, it will be easier
495 			**		on the reader.
496 			**	Then send to everyone.
497 			**	Finally give a reply code.  If an error has
498 			**		already been given, don't mail a
499 			**		message back.
500 			**	We goose error returns by clearing error bit.
501 			*/
502 
503 			SmtpPhase = "delivery";
504 			if (nrcpts != 1 && a == NULL)
505 			{
506 				HoldErrs = TRUE;
507 				e->e_errormode = EM_MAIL;
508 			}
509 			e->e_xfp = freopen(queuename(e, 'x'), "w", e->e_xfp);
510 			id = e->e_id;
511 
512 			/* send to all recipients */
513 			sendall(e, a == NULL ? SM_DEFAULT : SM_QUEUE);
514 			e->e_to = NULL;
515 
516 			/* save statistics */
517 			markstats(e, (ADDRESS *) NULL);
518 
519 			/* issue success if appropriate and reset */
520 			if (Errors == 0 || HoldErrs)
521 				message("250 %s Message accepted for delivery", id);
522 
523 			if (bitset(EF_FATALERRS, e->e_flags) && !HoldErrs)
524 			{
525 				/* avoid sending back an extra message */
526 				e->e_flags &= ~EF_FATALERRS;
527 				e->e_flags |= EF_CLRQUEUE;
528 			}
529 			else
530 			{
531 				/* from now on, we have to operate silently */
532 				HoldErrs = TRUE;
533 				e->e_errormode = EM_MAIL;
534 
535 				/* if we just queued, poke it */
536 				if (a != NULL && e->e_sendmode != SM_QUEUE)
537 				{
538 					unlockqueue(e);
539 					dowork(id, TRUE, TRUE, e);
540 					e->e_id = NULL;
541 				}
542 			}
543 
544   abortmessage:
545 			/* if in a child, pop back to our parent */
546 			if (InChild)
547 				finis();
548 
549 			/* clean up a bit */
550 			gotmail = FALSE;
551 			dropenvelope(e);
552 			CurEnv = e = newenvelope(e, CurEnv);
553 			e->e_flags = BlankEnvelope.e_flags;
554 			break;
555 
556 		  case CMDRSET:		/* rset -- reset state */
557 			message("250 Reset state");
558 			if (InChild)
559 				finis();
560 
561 			/* clean up a bit */
562 			gotmail = FALSE;
563 			dropenvelope(e);
564 			CurEnv = e = newenvelope(e, CurEnv);
565 			break;
566 
567 		  case CMDVRFY:		/* vrfy -- verify address */
568 		  case CMDEXPN:		/* expn -- expand address */
569 			vrfy = c->cmdcode == CMDVRFY;
570 			if (bitset(vrfy ? PRIV_NOVRFY : PRIV_NOEXPN,
571 						PrivacyFlags))
572 			{
573 				if (vrfy)
574 					message("252 Who's to say?");
575 				else
576 					message("502 That's none of your business");
577 				break;
578 			}
579 			else if (!gothello &&
580 				 bitset(vrfy ? PRIV_NEEDVRFYHELO : PRIV_NEEDEXPNHELO,
581 						PrivacyFlags))
582 			{
583 				message("503 I demand that you introduce yourself first");
584 				break;
585 			}
586 			if (runinchild(vrfy ? "SMTP-VRFY" : "SMTP-EXPN", e) > 0)
587 				break;
588 #ifdef LOG
589 			if (LogLevel > 5)
590 				syslog(LOG_INFO, "%s: %s", CurHostName, inp);
591 #endif
592 			vrfyqueue = NULL;
593 			QuickAbort = TRUE;
594 			if (vrfy)
595 				e->e_flags |= EF_VRFYONLY;
596 			(void) sendtolist(p, (ADDRESS *) NULL, &vrfyqueue, e);
597 			if (Errors != 0)
598 			{
599 				if (InChild)
600 					finis();
601 				break;
602 			}
603 			while (vrfyqueue != NULL)
604 			{
605 				register ADDRESS *a = vrfyqueue->q_next;
606 				char *code;
607 
608 				while (a != NULL && bitset(QDONTSEND|QBADADDR, a->q_flags))
609 					a = a->q_next;
610 
611 				if (!bitset(QDONTSEND|QBADADDR, vrfyqueue->q_flags))
612 					printvrfyaddr(vrfyqueue, a == NULL);
613 				else if (a == NULL)
614 					message("554 Self destructive alias loop");
615 				vrfyqueue = a;
616 			}
617 			if (InChild)
618 				finis();
619 			break;
620 
621 		  case CMDHELP:		/* help -- give user info */
622 			help(p);
623 			break;
624 
625 		  case CMDNOOP:		/* noop -- do nothing */
626 			message("200 OK");
627 			break;
628 
629 		  case CMDQUIT:		/* quit -- leave mail */
630 			message("221 %s closing connection", MyHostName);
631 			if (InChild)
632 				ExitStat = EX_QUIT;
633 			finis();
634 
635 		  case CMDVERB:		/* set verbose mode */
636 			if (bitset(PRIV_NOEXPN, PrivacyFlags))
637 			{
638 				/* this would give out the same info */
639 				message("502 Verbose unavailable");
640 				break;
641 			}
642 			Verbose = TRUE;
643 			e->e_sendmode = SM_DELIVER;
644 			message("250 Verbose mode");
645 			break;
646 
647 		  case CMDONEX:		/* doing one transaction only */
648 			OneXact = TRUE;
649 			message("250 Only one transaction");
650 			break;
651 
652 # ifdef SMTPDEBUG
653 		  case CMDDBGQSHOW:	/* show queues */
654 			printf("Send Queue=");
655 			printaddr(e->e_sendqueue, TRUE);
656 			break;
657 
658 		  case CMDDBGDEBUG:	/* set debug mode */
659 			tTsetup(tTdvect, sizeof tTdvect, "0-99.1");
660 			tTflag(p);
661 			message("200 Debug set");
662 			break;
663 
664 # else /* not SMTPDEBUG */
665 
666 		  case CMDDBGQSHOW:	/* show queues */
667 		  case CMDDBGDEBUG:	/* set debug mode */
668 # ifdef LOG
669 			if (LogLevel > 0)
670 				syslog(LOG_NOTICE,
671 				    "\"%s\" command from %s (%s)",
672 				    c->cmdname, RealHostName,
673 				    anynet_ntoa(&RealHostAddr));
674 # endif
675 			/* FALL THROUGH */
676 # endif /* SMTPDEBUG */
677 
678 		  case CMDERROR:	/* unknown command */
679 			message("500 Command unrecognized");
680 			break;
681 
682 		  default:
683 			errno = 0;
684 			syserr("500 smtp: unknown code %d", c->cmdcode);
685 			break;
686 		}
687 	}
688 }
689 /*
690 **  SKIPWORD -- skip a fixed word.
691 **
692 **	Parameters:
693 **		p -- place to start looking.
694 **		w -- word to skip.
695 **
696 **	Returns:
697 **		p following w.
698 **		NULL on error.
699 **
700 **	Side Effects:
701 **		clobbers the p data area.
702 */
703 
704 static char *
705 skipword(p, w)
706 	register char *p;
707 	char *w;
708 {
709 	register char *q;
710 
711 	/* find beginning of word */
712 	while (isascii(*p) && isspace(*p))
713 		p++;
714 	q = p;
715 
716 	/* find end of word */
717 	while (*p != '\0' && *p != ':' && !(isascii(*p) && isspace(*p)))
718 		p++;
719 	while (isascii(*p) && isspace(*p))
720 		*p++ = '\0';
721 	if (*p != ':')
722 	{
723 	  syntax:
724 		message("501 Syntax error");
725 		Errors++;
726 		return (NULL);
727 	}
728 	*p++ = '\0';
729 	while (isascii(*p) && isspace(*p))
730 		p++;
731 
732 	/* see if the input word matches desired word */
733 	if (strcasecmp(q, w))
734 		goto syntax;
735 
736 	return (p);
737 }
738 /*
739 **  PRINTVRFYADDR -- print an entry in the verify queue
740 **
741 **	Parameters:
742 **		a -- the address to print
743 **		last -- set if this is the last one.
744 **
745 **	Returns:
746 **		none.
747 **
748 **	Side Effects:
749 **		Prints the appropriate 250 codes.
750 */
751 
752 printvrfyaddr(a, last)
753 	register ADDRESS *a;
754 	bool last;
755 {
756 	char fmtbuf[20];
757 
758 	strcpy(fmtbuf, "250");
759 	fmtbuf[3] = last ? ' ' : '-';
760 
761 	if (a->q_fullname == NULL)
762 	{
763 		if (strchr(a->q_user, '@') == NULL)
764 			strcpy(&fmtbuf[4], "<%s@%s>");
765 		else
766 			strcpy(&fmtbuf[4], "<%s>");
767 		message(fmtbuf, a->q_user, MyHostName);
768 	}
769 	else
770 	{
771 		if (strchr(a->q_user, '@') == NULL)
772 			strcpy(&fmtbuf[4], "%s <%s@%s>");
773 		else
774 			strcpy(&fmtbuf[4], "%s <%s>");
775 		message(fmtbuf, a->q_fullname, a->q_user, MyHostName);
776 	}
777 }
778 /*
779 **  HELP -- implement the HELP command.
780 **
781 **	Parameters:
782 **		topic -- the topic we want help for.
783 **
784 **	Returns:
785 **		none.
786 **
787 **	Side Effects:
788 **		outputs the help file to message output.
789 */
790 
791 help(topic)
792 	char *topic;
793 {
794 	register FILE *hf;
795 	int len;
796 	char buf[MAXLINE];
797 	bool noinfo;
798 
799 	if (HelpFile == NULL || (hf = fopen(HelpFile, "r")) == NULL)
800 	{
801 		/* no help */
802 		errno = 0;
803 		message("502 HELP not implemented");
804 		return;
805 	}
806 
807 	if (topic == NULL || *topic == '\0')
808 		topic = "smtp";
809 	else
810 		makelower(topic);
811 
812 	len = strlen(topic);
813 	noinfo = TRUE;
814 
815 	while (fgets(buf, sizeof buf, hf) != NULL)
816 	{
817 		if (strncmp(buf, topic, len) == 0)
818 		{
819 			register char *p;
820 
821 			p = strchr(buf, '\t');
822 			if (p == NULL)
823 				p = buf;
824 			else
825 				p++;
826 			fixcrlf(p, TRUE);
827 			message("214-%s", p);
828 			noinfo = FALSE;
829 		}
830 	}
831 
832 	if (noinfo)
833 		message("504 HELP topic unknown");
834 	else
835 		message("214 End of HELP info");
836 	(void) fclose(hf);
837 }
838 /*
839 **  RUNINCHILD -- return twice -- once in the child, then in the parent again
840 **
841 **	Parameters:
842 **		label -- a string used in error messages
843 **
844 **	Returns:
845 **		zero in the child
846 **		one in the parent
847 **
848 **	Side Effects:
849 **		none.
850 */
851 
852 runinchild(label, e)
853 	char *label;
854 	register ENVELOPE *e;
855 {
856 	int childpid;
857 
858 	if (!OneXact)
859 	{
860 		childpid = dofork();
861 		if (childpid < 0)
862 		{
863 			syserr("%s: cannot fork", label);
864 			return (1);
865 		}
866 		if (childpid > 0)
867 		{
868 			auto int st;
869 
870 			/* parent -- wait for child to complete */
871 			setproctitle("srvrsmtp %s child wait", CurHostName);
872 			st = waitfor(childpid);
873 			if (st == -1)
874 				syserr("%s: lost child", label);
875 
876 			/* if we exited on a QUIT command, complete the process */
877 			if (st == (EX_QUIT << 8))
878 				finis();
879 
880 			return (1);
881 		}
882 		else
883 		{
884 			/* child */
885 			InChild = TRUE;
886 			QuickAbort = FALSE;
887 			clearenvelope(e, FALSE);
888 		}
889 	}
890 
891 	/* open alias database */
892 	initaliases(FALSE, e);
893 
894 	return (0);
895 }
896 
897 # endif /* SMTP */
898