xref: /386bsd/usr/src/usr.sbin/sendmail/src/daemon.c (revision a2142627)
1 /*
2  * Copyright (c) 1983 Eric P. Allman
3  * Copyright (c) 1988, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *	This product includes software developed by the University of
17  *	California, Berkeley and its contributors.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <errno.h>
36 #include "sendmail.h"
37 
38 #ifndef lint
39 #ifdef DAEMON
40 static char sccsid[] = "@(#)daemon.c	8.48 (Berkeley) 4/18/94 (with daemon mode)";
41 #else
42 static char sccsid[] = "@(#)daemon.c	8.48 (Berkeley) 4/18/94 (without daemon mode)";
43 #endif
44 #endif /* not lint */
45 
46 #ifdef DAEMON
47 
48 # include <netdb.h>
49 # include <arpa/inet.h>
50 
51 #if NAMED_BIND
52 # include <arpa/nameser.h>
53 # include <resolv.h>
54 #endif
55 
56 /*
57 **  DAEMON.C -- routines to use when running as a daemon.
58 **
59 **	This entire file is highly dependent on the 4.2 BSD
60 **	interprocess communication primitives.  No attempt has
61 **	been made to make this file portable to Version 7,
62 **	Version 6, MPX files, etc.  If you should try such a
63 **	thing yourself, I recommend chucking the entire file
64 **	and starting from scratch.  Basic semantics are:
65 **
66 **	getrequests()
67 **		Opens a port and initiates a connection.
68 **		Returns in a child.  Must set InChannel and
69 **		OutChannel appropriately.
70 **	clrdaemon()
71 **		Close any open files associated with getting
72 **		the connection; this is used when running the queue,
73 **		etc., to avoid having extra file descriptors during
74 **		the queue run and to avoid confusing the network
75 **		code (if it cares).
76 **	makeconnection(host, port, outfile, infile, usesecureport)
77 **		Make a connection to the named host on the given
78 **		port.  Set *outfile and *infile to the files
79 **		appropriate for communication.  Returns zero on
80 **		success, else an exit status describing the
81 **		error.
82 **	host_map_lookup(map, hbuf, avp, pstat)
83 **		Convert the entry in hbuf into a canonical form.
84 */
85 /*
86 **  GETREQUESTS -- open mail IPC port and get requests.
87 **
88 **	Parameters:
89 **		none.
90 **
91 **	Returns:
92 **		none.
93 **
94 **	Side Effects:
95 **		Waits until some interesting activity occurs.  When
96 **		it does, a child is created to process it, and the
97 **		parent waits for completion.  Return from this
98 **		routine is always in the child.  The file pointers
99 **		"InChannel" and "OutChannel" should be set to point
100 **		to the communication channel.
101 */
102 
103 int		DaemonSocket	= -1;		/* fd describing socket */
104 SOCKADDR	DaemonAddr;			/* socket for incoming */
105 int		ListenQueueSize = 10;		/* size of listen queue */
106 int		TcpRcvBufferSize = 0;		/* size of TCP receive buffer */
107 int		TcpSndBufferSize = 0;		/* size of TCP send buffer */
108 
getrequests()109 getrequests()
110 {
111 	int t;
112 	bool refusingconnections = TRUE;
113 	FILE *pidf;
114 	int socksize;
115 #ifdef XDEBUG
116 	bool j_has_dot;
117 #endif
118 	extern void reapchild();
119 
120 	/*
121 	**  Set up the address for the mailer.
122 	*/
123 
124 	if (DaemonAddr.sin.sin_family == 0)
125 		DaemonAddr.sin.sin_family = AF_INET;
126 	if (DaemonAddr.sin.sin_addr.s_addr == 0)
127 		DaemonAddr.sin.sin_addr.s_addr = INADDR_ANY;
128 	if (DaemonAddr.sin.sin_port == 0)
129 	{
130 		register struct servent *sp;
131 
132 		sp = getservbyname("smtp", "tcp");
133 		if (sp == NULL)
134 		{
135 			syserr("554 service \"smtp\" unknown");
136 			DaemonAddr.sin.sin_port = htons(25);
137 		}
138 		else
139 			DaemonAddr.sin.sin_port = sp->s_port;
140 	}
141 
142 	/*
143 	**  Try to actually open the connection.
144 	*/
145 
146 	if (tTd(15, 1))
147 		printf("getrequests: port 0x%x\n", DaemonAddr.sin.sin_port);
148 
149 	/* get a socket for the SMTP connection */
150 	socksize = opendaemonsocket(TRUE);
151 
152 	(void) setsignal(SIGCHLD, reapchild);
153 
154 	/* write the pid to the log file for posterity */
155 	pidf = fopen(PidFile, "w");
156 	if (pidf != NULL)
157 	{
158 		extern char *CommandLineArgs;
159 
160 		/* write the process id on line 1 */
161 		fprintf(pidf, "%d\n", getpid());
162 
163 		/* line 2 contains all command line flags */
164 		fprintf(pidf, "%s\n", CommandLineArgs);
165 
166 		/* flush and close */
167 		fclose(pidf);
168 	}
169 
170 #ifdef XDEBUG
171 	{
172 		char jbuf[MAXHOSTNAMELEN];
173 
174 		expand("\201j", jbuf, &jbuf[sizeof jbuf - 1], CurEnv);
175 		j_has_dot = strchr(jbuf, '.') != NULL;
176 	}
177 #endif
178 
179 	if (tTd(15, 1))
180 		printf("getrequests: %d\n", DaemonSocket);
181 
182 	for (;;)
183 	{
184 		register int pid;
185 		auto int lotherend;
186 		extern bool refuseconnections();
187 
188 		/* see if we are rejecting connections */
189 		CurrentLA = getla();
190 		if (refuseconnections())
191 		{
192 			if (DaemonSocket >= 0)
193 			{
194 				/* close socket so peer will fail quickly */
195 				(void) close(DaemonSocket);
196 				DaemonSocket = -1;
197 			}
198 			refusingconnections = TRUE;
199 			setproctitle("rejecting connections: load average: %d",
200 				CurrentLA);
201 			sleep(15);
202 			continue;
203 		}
204 
205 		if (refusingconnections)
206 		{
207 			/* start listening again */
208 			(void) opendaemonsocket(FALSE);
209 			setproctitle("accepting connections");
210 			refusingconnections = FALSE;
211 		}
212 
213 #ifdef XDEBUG
214 		/* check for disaster */
215 		{
216 			register STAB *s;
217 			char jbuf[MAXHOSTNAMELEN];
218 
219 			expand("\201j", jbuf, &jbuf[sizeof jbuf - 1], CurEnv);
220 			if ((s = stab(jbuf, ST_CLASS, ST_FIND)) == NULL ||
221 			    !bitnset('w', s->s_class))
222 			{
223 				dumpstate("daemon lost $j");
224 				syslog(LOG_ALERT, "daemon process doesn't have $j in $=w; see syslog");
225 				abort();
226 			}
227 			else if (j_has_dot && strchr(jbuf, '.') == NULL)
228 			{
229 				dumpstate("daemon $j lost dot");
230 				syslog(LOG_ALERT, "daemon process $j lost dot; see syslog");
231 				abort();
232 			}
233 		}
234 #endif
235 
236 		/* wait for a connection */
237 		do
238 		{
239 			errno = 0;
240 			lotherend = socksize;
241 			t = accept(DaemonSocket,
242 			    (struct sockaddr *)&RealHostAddr, &lotherend);
243 		} while (t < 0 && errno == EINTR);
244 		if (t < 0)
245 		{
246 			syserr("getrequests: accept");
247 			sleep(5);
248 			continue;
249 		}
250 
251 		/*
252 		**  Create a subprocess to process the mail.
253 		*/
254 
255 		if (tTd(15, 2))
256 			printf("getrequests: forking (fd = %d)\n", t);
257 
258 		pid = fork();
259 		if (pid < 0)
260 		{
261 			syserr("daemon: cannot fork");
262 			sleep(10);
263 			(void) close(t);
264 			continue;
265 		}
266 
267 		if (pid == 0)
268 		{
269 			char *p;
270 			extern char *hostnamebyanyaddr();
271 
272 			/*
273 			**  CHILD -- return to caller.
274 			**	Collect verified idea of sending host.
275 			**	Verify calling user id if possible here.
276 			*/
277 
278 			(void) setsignal(SIGCHLD, SIG_DFL);
279 			DisConnected = FALSE;
280 
281 			setproctitle("startup with %s",
282 				anynet_ntoa(&RealHostAddr));
283 
284 			/* determine host name */
285 			p = hostnamebyanyaddr(&RealHostAddr);
286 			RealHostName = newstr(p);
287 			setproctitle("startup with %s", p);
288 
289 #ifdef LOG
290 			if (LogLevel > 11)
291 			{
292 				/* log connection information */
293 				syslog(LOG_INFO, "connect from %s (%s)",
294 					RealHostName, anynet_ntoa(&RealHostAddr));
295 			}
296 #endif
297 
298 			(void) close(DaemonSocket);
299 			if ((InChannel = fdopen(t, "r")) == NULL ||
300 			    (t = dup(t)) < 0 ||
301 			    (OutChannel = fdopen(t, "w")) == NULL)
302 			{
303 				syserr("cannot open SMTP server channel, fd=%d", t);
304 				exit(0);
305 			}
306 
307 			/* should we check for illegal connection here? XXX */
308 #ifdef XLA
309 			if (!xla_host_ok(RealHostName))
310 			{
311 				message("421 Too many SMTP sessions for this host");
312 				exit(0);
313 			}
314 #endif
315 
316 			if (tTd(15, 2))
317 				printf("getreq: returning\n");
318 			return;
319 		}
320 
321 		/* close the port so that others will hang (for a while) */
322 		(void) close(t);
323 	}
324 	/*NOTREACHED*/
325 }
326 /*
327 **  OPENDAEMONSOCKET -- open the SMTP socket
328 **
329 **	Deals with setting all appropriate options.  DaemonAddr must
330 **	be set up in advance.
331 **
332 **	Parameters:
333 **		firsttime -- set if this is the initial open.
334 **
335 **	Returns:
336 **		Size in bytes of the daemon socket addr.
337 **
338 **	Side Effects:
339 **		Leaves DaemonSocket set to the open socket.
340 **		Exits if the socket cannot be created.
341 */
342 
343 #define MAXOPENTRIES	10	/* maximum number of tries to open connection */
344 
345 int
opendaemonsocket(firsttime)346 opendaemonsocket(firsttime)
347 	bool firsttime;
348 {
349 	int on = 1;
350 	int socksize;
351 	int ntries = 0;
352 	int saveerrno;
353 
354 	if (tTd(15, 2))
355 		printf("opendaemonsocket()\n");
356 
357 	do
358 	{
359 		if (ntries > 0)
360 			sleep(5);
361 		if (firsttime || DaemonSocket < 0)
362 		{
363 			DaemonSocket = socket(DaemonAddr.sa.sa_family, SOCK_STREAM, 0);
364 			if (DaemonSocket < 0)
365 			{
366 				/* probably another daemon already */
367 				saveerrno = errno;
368 				syserr("opendaemonsocket: can't create server SMTP socket");
369 			  severe:
370 # ifdef LOG
371 				if (LogLevel > 0)
372 					syslog(LOG_ALERT, "problem creating SMTP socket");
373 # endif /* LOG */
374 				DaemonSocket = -1;
375 				continue;
376 			}
377 
378 			/* turn on network debugging? */
379 			if (tTd(15, 101))
380 				(void) setsockopt(DaemonSocket, SOL_SOCKET,
381 						  SO_DEBUG, (char *)&on,
382 						  sizeof on);
383 
384 			(void) setsockopt(DaemonSocket, SOL_SOCKET,
385 					  SO_REUSEADDR, (char *)&on, sizeof on);
386 			(void) setsockopt(DaemonSocket, SOL_SOCKET,
387 					  SO_KEEPALIVE, (char *)&on, sizeof on);
388 
389 #ifdef SO_RCVBUF
390 			if (TcpRcvBufferSize > 0)
391 			{
392 				if (setsockopt(DaemonSocket, SOL_SOCKET,
393 					       SO_RCVBUF,
394 					       (char *) &TcpRcvBufferSize,
395 					       sizeof(TcpRcvBufferSize)) < 0)
396 					syserr("getrequests: setsockopt(SO_RCVBUF)");
397 			}
398 #endif
399 
400 			switch (DaemonAddr.sa.sa_family)
401 			{
402 # ifdef NETINET
403 			  case AF_INET:
404 				socksize = sizeof DaemonAddr.sin;
405 				break;
406 # endif
407 
408 # ifdef NETISO
409 			  case AF_ISO:
410 				socksize = sizeof DaemonAddr.siso;
411 				break;
412 # endif
413 
414 			  default:
415 				socksize = sizeof DaemonAddr;
416 				break;
417 			}
418 
419 			if (bind(DaemonSocket, &DaemonAddr.sa, socksize) < 0)
420 			{
421 				saveerrno = errno;
422 				syserr("getrequests: cannot bind");
423 				(void) close(DaemonSocket);
424 				goto severe;
425 			}
426 		}
427 		if (!firsttime && listen(DaemonSocket, ListenQueueSize) < 0)
428 		{
429 			saveerrno = errno;
430 			syserr("getrequests: cannot listen");
431 			(void) close(DaemonSocket);
432 			goto severe;
433 		}
434 		return socksize;
435 	} while (ntries++ < MAXOPENTRIES && transienterror(saveerrno));
436 	finis();
437 }
438 /*
439 **  CLRDAEMON -- reset the daemon connection
440 **
441 **	Parameters:
442 **		none.
443 **
444 **	Returns:
445 **		none.
446 **
447 **	Side Effects:
448 **		releases any resources used by the passive daemon.
449 */
450 
clrdaemon()451 clrdaemon()
452 {
453 	if (DaemonSocket >= 0)
454 		(void) close(DaemonSocket);
455 	DaemonSocket = -1;
456 }
457 /*
458 **  SETDAEMONOPTIONS -- set options for running the daemon
459 **
460 **	Parameters:
461 **		p -- the options line.
462 **
463 **	Returns:
464 **		none.
465 */
466 
setdaemonoptions(p)467 setdaemonoptions(p)
468 	register char *p;
469 {
470 	if (DaemonAddr.sa.sa_family == AF_UNSPEC)
471 		DaemonAddr.sa.sa_family = AF_INET;
472 
473 	while (p != NULL)
474 	{
475 		register char *f;
476 		register char *v;
477 
478 		while (isascii(*p) && isspace(*p))
479 			p++;
480 		if (*p == '\0')
481 			break;
482 		f = p;
483 		p = strchr(p, ',');
484 		if (p != NULL)
485 			*p++ = '\0';
486 		v = strchr(f, '=');
487 		if (v == NULL)
488 			continue;
489 		while (isascii(*++v) && isspace(*v))
490 			continue;
491 
492 		switch (*f)
493 		{
494 		  case 'F':		/* address family */
495 			if (isascii(*v) && isdigit(*v))
496 				DaemonAddr.sa.sa_family = atoi(v);
497 #ifdef NETINET
498 			else if (strcasecmp(v, "inet") == 0)
499 				DaemonAddr.sa.sa_family = AF_INET;
500 #endif
501 #ifdef NETISO
502 			else if (strcasecmp(v, "iso") == 0)
503 				DaemonAddr.sa.sa_family = AF_ISO;
504 #endif
505 #ifdef NETNS
506 			else if (strcasecmp(v, "ns") == 0)
507 				DaemonAddr.sa.sa_family = AF_NS;
508 #endif
509 #ifdef NETX25
510 			else if (strcasecmp(v, "x.25") == 0)
511 				DaemonAddr.sa.sa_family = AF_CCITT;
512 #endif
513 			else
514 				syserr("554 Unknown address family %s in Family=option", v);
515 			break;
516 
517 		  case 'A':		/* address */
518 			switch (DaemonAddr.sa.sa_family)
519 			{
520 #ifdef NETINET
521 			  case AF_INET:
522 				if (isascii(*v) && isdigit(*v))
523 					DaemonAddr.sin.sin_addr.s_addr = inet_network(v);
524 				else
525 				{
526 					register struct netent *np;
527 
528 					np = getnetbyname(v);
529 					if (np == NULL)
530 						syserr("554 network \"%s\" unknown", v);
531 					else
532 						DaemonAddr.sin.sin_addr.s_addr = np->n_net;
533 				}
534 				break;
535 #endif
536 
537 			  default:
538 				syserr("554 Address= option unsupported for family %d",
539 					DaemonAddr.sa.sa_family);
540 				break;
541 			}
542 			break;
543 
544 		  case 'P':		/* port */
545 			switch (DaemonAddr.sa.sa_family)
546 			{
547 				short port;
548 
549 #ifdef NETINET
550 			  case AF_INET:
551 				if (isascii(*v) && isdigit(*v))
552 					DaemonAddr.sin.sin_port = htons(atoi(v));
553 				else
554 				{
555 					register struct servent *sp;
556 
557 					sp = getservbyname(v, "tcp");
558 					if (sp == NULL)
559 						syserr("554 service \"%s\" unknown", v);
560 					else
561 						DaemonAddr.sin.sin_port = sp->s_port;
562 				}
563 				break;
564 #endif
565 
566 #ifdef NETISO
567 			  case AF_ISO:
568 				/* assume two byte transport selector */
569 				if (isascii(*v) && isdigit(*v))
570 					port = htons(atoi(v));
571 				else
572 				{
573 					register struct servent *sp;
574 
575 					sp = getservbyname(v, "tcp");
576 					if (sp == NULL)
577 						syserr("554 service \"%s\" unknown", v);
578 					else
579 						port = sp->s_port;
580 				}
581 				bcopy((char *) &port, TSEL(&DaemonAddr.siso), 2);
582 				break;
583 #endif
584 
585 			  default:
586 				syserr("554 Port= option unsupported for family %d",
587 					DaemonAddr.sa.sa_family);
588 				break;
589 			}
590 			break;
591 
592 		  case 'L':		/* listen queue size */
593 			ListenQueueSize = atoi(v);
594 			break;
595 
596 		  case 'S':		/* send buffer size */
597 			TcpSndBufferSize = atoi(v);
598 			break;
599 
600 		  case 'R':		/* receive buffer size */
601 			TcpRcvBufferSize = atoi(v);
602 			break;
603 		}
604 	}
605 }
606 /*
607 **  MAKECONNECTION -- make a connection to an SMTP socket on another machine.
608 **
609 **	Parameters:
610 **		host -- the name of the host.
611 **		port -- the port number to connect to.
612 **		mci -- a pointer to the mail connection information
613 **			structure to be filled in.
614 **		usesecureport -- if set, use a low numbered (reserved)
615 **			port to provide some rudimentary authentication.
616 **
617 **	Returns:
618 **		An exit code telling whether the connection could be
619 **			made and if not why not.
620 **
621 **	Side Effects:
622 **		none.
623 */
624 
625 SOCKADDR	CurHostAddr;		/* address of current host */
626 
627 int
makeconnection(host,port,mci,usesecureport)628 makeconnection(host, port, mci, usesecureport)
629 	char *host;
630 	u_short port;
631 	register MCI *mci;
632 	bool usesecureport;
633 {
634 	register int i, s;
635 	register struct hostent *hp = (struct hostent *)NULL;
636 	SOCKADDR addr;
637 	int sav_errno;
638 	int addrlen;
639 #if NAMED_BIND
640 	extern int h_errno;
641 #endif
642 
643 	/*
644 	**  Set up the address for the mailer.
645 	**	Accept "[a.b.c.d]" syntax for host name.
646 	*/
647 
648 #if NAMED_BIND
649 	h_errno = 0;
650 #endif
651 	errno = 0;
652 	bzero(&CurHostAddr, sizeof CurHostAddr);
653 	SmtpPhase = mci->mci_phase = "initial connection";
654 	CurHostName = host;
655 
656 	if (host[0] == '[')
657 	{
658 		long hid;
659 		register char *p = strchr(host, ']');
660 
661 		if (p != NULL)
662 		{
663 			*p = '\0';
664 #ifdef NETINET
665 			hid = inet_addr(&host[1]);
666 			if (hid == -1)
667 #endif
668 			{
669 				/* try it as a host name (avoid MX lookup) */
670 				hp = gethostbyname(&host[1]);
671 				if (hp == NULL && p[-1] == '.')
672 				{
673 					p[-1] = '\0';
674 					hp = gethostbyname(&host[1]);
675 					p[-1] = '.';
676 				}
677 				*p = ']';
678 				goto gothostent;
679 			}
680 			*p = ']';
681 		}
682 		if (p == NULL)
683 		{
684 			usrerr("553 Invalid numeric domain spec \"%s\"", host);
685 			return (EX_NOHOST);
686 		}
687 #ifdef NETINET
688 		addr.sin.sin_family = AF_INET;		/*XXX*/
689 		addr.sin.sin_addr.s_addr = hid;
690 #endif
691 	}
692 	else
693 	{
694 		register char *p = &host[strlen(host) - 1];
695 
696 		hp = gethostbyname(host);
697 		if (hp == NULL && *p == '.')
698 		{
699 			*p = '\0';
700 			hp = gethostbyname(host);
701 			*p = '.';
702 		}
703 gothostent:
704 		if (hp == NULL)
705 		{
706 #if NAMED_BIND
707 			if (errno == ETIMEDOUT || h_errno == TRY_AGAIN)
708 				return (EX_TEMPFAIL);
709 
710 			/* if name server is specified, assume temp fail */
711 			if (errno == ECONNREFUSED && UseNameServer)
712 				return (EX_TEMPFAIL);
713 #endif
714 			return (EX_NOHOST);
715 		}
716 		addr.sa.sa_family = hp->h_addrtype;
717 		switch (hp->h_addrtype)
718 		{
719 #ifdef NETINET
720 		  case AF_INET:
721 			bcopy(hp->h_addr,
722 				&addr.sin.sin_addr,
723 				sizeof addr.sin.sin_addr);
724 			break;
725 #endif
726 
727 		  default:
728 			bcopy(hp->h_addr,
729 				addr.sa.sa_data,
730 				hp->h_length);
731 			break;
732 		}
733 		i = 1;
734 	}
735 
736 	/*
737 	**  Determine the port number.
738 	*/
739 
740 	if (port != 0)
741 		port = htons(port);
742 	else
743 	{
744 		register struct servent *sp = getservbyname("smtp", "tcp");
745 
746 		if (sp == NULL)
747 		{
748 			syserr("554 makeconnection: service \"smtp\" unknown");
749 			port = htons(25);
750 		}
751 		else
752 			port = sp->s_port;
753 	}
754 
755 	switch (addr.sa.sa_family)
756 	{
757 #ifdef NETINET
758 	  case AF_INET:
759 		addr.sin.sin_port = port;
760 		addrlen = sizeof (struct sockaddr_in);
761 		break;
762 #endif
763 
764 #ifdef NETISO
765 	  case AF_ISO:
766 		/* assume two byte transport selector */
767 		bcopy((char *) &port, TSEL((struct sockaddr_iso *) &addr), 2);
768 		addrlen = sizeof (struct sockaddr_iso);
769 		break;
770 #endif
771 
772 	  default:
773 		syserr("Can't connect to address family %d", addr.sa.sa_family);
774 		return (EX_NOHOST);
775 	}
776 
777 	/*
778 	**  Try to actually open the connection.
779 	*/
780 
781 #ifdef XLA
782 	/* if too many connections, don't bother trying */
783 	if (!xla_noqueue_ok(host))
784 		return EX_TEMPFAIL;
785 #endif
786 
787 	for (;;)
788 	{
789 		if (tTd(16, 1))
790 			printf("makeconnection (%s [%s])\n",
791 				host, anynet_ntoa(&addr));
792 
793 		/* save for logging */
794 		CurHostAddr = addr;
795 
796 		if (usesecureport)
797 		{
798 			int rport = IPPORT_RESERVED - 1;
799 
800 			s = rresvport(&rport);
801 		}
802 		else
803 		{
804 			s = socket(AF_INET, SOCK_STREAM, 0);
805 		}
806 		if (s < 0)
807 		{
808 			sav_errno = errno;
809 			syserr("makeconnection: no socket");
810 			goto failure;
811 		}
812 
813 #ifdef SO_SNDBUF
814 		if (TcpSndBufferSize > 0)
815 		{
816 			if (setsockopt(s, SOL_SOCKET, SO_SNDBUF,
817 				       (char *) &TcpSndBufferSize,
818 				       sizeof(TcpSndBufferSize)) < 0)
819 				syserr("makeconnection: setsockopt(SO_SNDBUF)");
820 		}
821 #endif
822 
823 		if (tTd(16, 1))
824 			printf("makeconnection: fd=%d\n", s);
825 
826 		/* turn on network debugging? */
827 		if (tTd(16, 101))
828 		{
829 			int on = 1;
830 			(void) setsockopt(s, SOL_SOCKET, SO_DEBUG,
831 					  (char *)&on, sizeof on);
832 		}
833 		if (CurEnv->e_xfp != NULL)
834 			(void) fflush(CurEnv->e_xfp);		/* for debugging */
835 		errno = 0;					/* for debugging */
836 		if (connect(s, (struct sockaddr *) &addr, addrlen) >= 0)
837 			break;
838 
839 		/* couldn't connect.... figure out why */
840 		sav_errno = errno;
841 		(void) close(s);
842 		if (hp && hp->h_addr_list[i])
843 		{
844 			if (tTd(16, 1))
845 				printf("Connect failed (%s); trying new address....\n",
846 					errstring(sav_errno));
847 			switch (addr.sa.sa_family)
848 			{
849 #ifdef NETINET
850 			  case AF_INET:
851 				bcopy(hp->h_addr_list[i++],
852 				      &addr.sin.sin_addr,
853 				      sizeof addr.sin.sin_addr);
854 				break;
855 #endif
856 
857 			  default:
858 				bcopy(hp->h_addr_list[i++],
859 					addr.sa.sa_data,
860 					hp->h_length);
861 				break;
862 			}
863 			continue;
864 		}
865 
866 		/* failure, decide if temporary or not */
867 	failure:
868 #ifdef XLA
869 		xla_host_end(host);
870 #endif
871 		if (transienterror(sav_errno))
872 			return EX_TEMPFAIL;
873 		else
874 		{
875 			message("%s", errstring(sav_errno));
876 			return (EX_UNAVAILABLE);
877 		}
878 	}
879 
880 	/* connection ok, put it into canonical form */
881 	if ((mci->mci_out = fdopen(s, "w")) == NULL ||
882 	    (s = dup(s)) < 0 ||
883 	    (mci->mci_in = fdopen(s, "r")) == NULL)
884 	{
885 		syserr("cannot open SMTP client channel, fd=%d", s);
886 		return EX_TEMPFAIL;
887 	}
888 
889 	return (EX_OK);
890 }
891 /*
892 **  MYHOSTNAME -- return the name of this host.
893 **
894 **	Parameters:
895 **		hostbuf -- a place to return the name of this host.
896 **		size -- the size of hostbuf.
897 **
898 **	Returns:
899 **		A list of aliases for this host.
900 **
901 **	Side Effects:
902 **		Adds numeric codes to $=w.
903 */
904 
905 char **
myhostname(hostbuf,size)906 myhostname(hostbuf, size)
907 	char hostbuf[];
908 	int size;
909 {
910 	register struct hostent *hp;
911 	extern struct hostent *gethostbyname();
912 
913 	if (gethostname(hostbuf, size) < 0)
914 	{
915 		(void) strcpy(hostbuf, "localhost");
916 	}
917 	hp = gethostbyname(hostbuf);
918 	if (hp == NULL)
919 	{
920 		syserr("!My host name (%s) does not seem to exist!", hostbuf);
921 	}
922 	(void) strncpy(hostbuf, hp->h_name, size - 1);
923 	hostbuf[size - 1] = '\0';
924 
925 #if NAMED_BIND
926 	/* if still no dot, try DNS directly (i.e., avoid NIS problems) */
927 	if (strchr(hostbuf, '.') == NULL)
928 	{
929 		extern bool getcanonname();
930 		extern int h_errno;
931 
932 		/* try twice in case name server not yet started up */
933 		if (!getcanonname(hostbuf, size, TRUE) &&
934 		    UseNameServer &&
935 		    (h_errno != TRY_AGAIN ||
936 		     (sleep(30), !getcanonname(hostbuf, size, TRUE))))
937 		{
938 			errno = h_errno + E_DNSBASE;
939 			syserr("!My host name (%s) not known to DNS",
940 				hostbuf);
941 		}
942 	}
943 #endif
944 
945 	if (hp->h_addrtype == AF_INET && hp->h_length == 4)
946 	{
947 		register int i;
948 
949 		for (i = 0; hp->h_addr_list[i] != NULL; i++)
950 		{
951 			char ipbuf[100];
952 
953 			sprintf(ipbuf, "[%s]",
954 				inet_ntoa(*((struct in_addr *) hp->h_addr_list[i])));
955 			setclass('w', ipbuf);
956 		}
957 	}
958 
959 	return (hp->h_aliases);
960 }
961 /*
962 **  GETAUTHINFO -- get the real host name asociated with a file descriptor
963 **
964 **	Uses RFC1413 protocol to try to get info from the other end.
965 **
966 **	Parameters:
967 **		fd -- the descriptor
968 **
969 **	Returns:
970 **		The user@host information associated with this descriptor.
971 */
972 
973 #if IDENTPROTO
974 
975 static jmp_buf	CtxAuthTimeout;
976 
977 static
authtimeout()978 authtimeout()
979 {
980 	longjmp(CtxAuthTimeout, 1);
981 }
982 
983 #endif
984 
985 char *
getauthinfo(fd)986 getauthinfo(fd)
987 	int fd;
988 {
989 	int falen;
990 	register char *p;
991 #if IDENTPROTO
992 	SOCKADDR la;
993 	int lalen;
994 	register struct servent *sp;
995 	int s;
996 	int i;
997 	EVENT *ev;
998 #endif
999 	static char hbuf[MAXNAME * 2 + 2];
1000 	extern char *hostnamebyanyaddr();
1001 	extern char RealUserName[];			/* main.c */
1002 
1003 	falen = sizeof RealHostAddr;
1004 	if (getpeername(fd, &RealHostAddr.sa, &falen) < 0 || falen <= 0 ||
1005 	    RealHostAddr.sa.sa_family == 0)
1006 	{
1007 		(void) sprintf(hbuf, "%s@localhost", RealUserName);
1008 		if (tTd(9, 1))
1009 			printf("getauthinfo: %s\n", hbuf);
1010 		return hbuf;
1011 	}
1012 
1013 	if (RealHostName == NULL)
1014 	{
1015 		/* translate that to a host name */
1016 		RealHostName = newstr(hostnamebyanyaddr(&RealHostAddr));
1017 	}
1018 
1019 #if IDENTPROTO
1020 	if (TimeOuts.to_ident == 0)
1021 		goto noident;
1022 
1023 	lalen = sizeof la;
1024 	if (RealHostAddr.sa.sa_family != AF_INET ||
1025 	    getsockname(fd, &la.sa, &lalen) < 0 || lalen <= 0 ||
1026 	    la.sa.sa_family != AF_INET)
1027 	{
1028 		/* no ident info */
1029 		goto noident;
1030 	}
1031 
1032 	/* create ident query */
1033 	(void) sprintf(hbuf, "%d,%d\r\n",
1034 		ntohs(RealHostAddr.sin.sin_port), ntohs(la.sin.sin_port));
1035 
1036 	/* create local address */
1037 	la.sin.sin_port = 0;
1038 
1039 	/* create foreign address */
1040 	sp = getservbyname("auth", "tcp");
1041 	if (sp != NULL)
1042 		RealHostAddr.sin.sin_port = sp->s_port;
1043 	else
1044 		RealHostAddr.sin.sin_port = htons(113);
1045 
1046 	s = -1;
1047 	if (setjmp(CtxAuthTimeout) != 0)
1048 	{
1049 		if (s >= 0)
1050 			(void) close(s);
1051 		goto noident;
1052 	}
1053 
1054 	/* put a timeout around the whole thing */
1055 	ev = setevent(TimeOuts.to_ident, authtimeout, 0);
1056 
1057 	/* connect to foreign IDENT server using same address as SMTP socket */
1058 	s = socket(AF_INET, SOCK_STREAM, 0);
1059 	if (s < 0)
1060 	{
1061 		clrevent(ev);
1062 		goto noident;
1063 	}
1064 	if (bind(s, &la.sa, sizeof la.sin) < 0 ||
1065 	    connect(s, &RealHostAddr.sa, sizeof RealHostAddr.sin) < 0)
1066 	{
1067 		goto closeident;
1068 	}
1069 
1070 	if (tTd(9, 10))
1071 		printf("getauthinfo: sent %s", hbuf);
1072 
1073 	/* send query */
1074 	if (write(s, hbuf, strlen(hbuf)) < 0)
1075 		goto closeident;
1076 
1077 	/* get result */
1078 	i = read(s, hbuf, sizeof hbuf);
1079 	(void) close(s);
1080 	clrevent(ev);
1081 	if (i <= 0)
1082 		goto noident;
1083 	if (hbuf[--i] == '\n' && hbuf[--i] == '\r')
1084 		i--;
1085 	hbuf[++i] = '\0';
1086 
1087 	if (tTd(9, 3))
1088 		printf("getauthinfo:  got %s\n", hbuf);
1089 
1090 	/* parse result */
1091 	p = strchr(hbuf, ':');
1092 	if (p == NULL)
1093 	{
1094 		/* malformed response */
1095 		goto noident;
1096 	}
1097 	while (isascii(*++p) && isspace(*p))
1098 		continue;
1099 	if (strncasecmp(p, "userid", 6) != 0)
1100 	{
1101 		/* presumably an error string */
1102 		goto noident;
1103 	}
1104 	p += 6;
1105 	while (isascii(*p) && isspace(*p))
1106 		p++;
1107 	if (*p++ != ':')
1108 	{
1109 		/* either useridxx or malformed response */
1110 		goto noident;
1111 	}
1112 
1113 	/* p now points to the OSTYPE field */
1114 	p = strchr(p, ':');
1115 	if (p == NULL)
1116 	{
1117 		/* malformed response */
1118 		goto noident;
1119 	}
1120 
1121 	/* 1413 says don't do this -- but it's broken otherwise */
1122 	while (isascii(*++p) && isspace(*p))
1123 		continue;
1124 
1125 	/* p now points to the authenticated name */
1126 	(void) sprintf(hbuf, "%s@%s",
1127 		p, RealHostName == NULL ? "localhost" : RealHostName);
1128 	goto finish;
1129 
1130 closeident:
1131 	(void) close(s);
1132 	clrevent(ev);
1133 
1134 #endif /* IDENTPROTO */
1135 
1136 noident:
1137 	if (RealHostName == NULL)
1138 	{
1139 		if (tTd(9, 1))
1140 			printf("getauthinfo: NULL\n");
1141 		return NULL;
1142 	}
1143 	(void) strcpy(hbuf, RealHostName);
1144 
1145 finish:
1146 	if (RealHostName != NULL && RealHostName[0] != '[')
1147 	{
1148 		p = &hbuf[strlen(hbuf)];
1149 		(void) sprintf(p, " [%s]", anynet_ntoa(&RealHostAddr));
1150 	}
1151 	if (tTd(9, 1))
1152 		printf("getauthinfo: %s\n", hbuf);
1153 	return hbuf;
1154 }
1155 /*
1156 **  HOST_MAP_LOOKUP -- turn a hostname into canonical form
1157 **
1158 **	Parameters:
1159 **		map -- a pointer to this map (unused).
1160 **		name -- the (presumably unqualified) hostname.
1161 **		av -- unused -- for compatibility with other mapping
1162 **			functions.
1163 **		statp -- an exit status (out parameter) -- set to
1164 **			EX_TEMPFAIL if the name server is unavailable.
1165 **
1166 **	Returns:
1167 **		The mapping, if found.
1168 **		NULL if no mapping found.
1169 **
1170 **	Side Effects:
1171 **		Looks up the host specified in hbuf.  If it is not
1172 **		the canonical name for that host, return the canonical
1173 **		name.
1174 */
1175 
1176 char *
host_map_lookup(map,name,av,statp)1177 host_map_lookup(map, name, av, statp)
1178 	MAP *map;
1179 	char *name;
1180 	char **av;
1181 	int *statp;
1182 {
1183 	register struct hostent *hp;
1184 	u_long in_addr;
1185 	char *cp;
1186 	int i;
1187 	register STAB *s;
1188 	char hbuf[MAXNAME];
1189 	extern struct hostent *gethostbyaddr();
1190 #if NAMED_BIND
1191 	extern int h_errno;
1192 #endif
1193 
1194 	/*
1195 	**  See if we have already looked up this name.  If so, just
1196 	**  return it.
1197 	*/
1198 
1199 	s = stab(name, ST_NAMECANON, ST_ENTER);
1200 	if (bitset(NCF_VALID, s->s_namecanon.nc_flags))
1201 	{
1202 		if (tTd(9, 1))
1203 			printf("host_map_lookup(%s) => CACHE %s\n",
1204 				name, s->s_namecanon.nc_cname);
1205 		errno = s->s_namecanon.nc_errno;
1206 #if NAMED_BIND
1207 		h_errno = s->s_namecanon.nc_herrno;
1208 #endif
1209 		*statp = s->s_namecanon.nc_stat;
1210 		if (CurEnv->e_message == NULL && *statp == EX_TEMPFAIL)
1211 		{
1212 			sprintf(hbuf, "%s: Name server timeout",
1213 				shortenstring(name, 33));
1214 			CurEnv->e_message = newstr(hbuf);
1215 		}
1216 		return s->s_namecanon.nc_cname;
1217 	}
1218 
1219 	/*
1220 	**  If first character is a bracket, then it is an address
1221 	**  lookup.  Address is copied into a temporary buffer to
1222 	**  strip the brackets and to preserve name if address is
1223 	**  unknown.
1224 	*/
1225 
1226 	if (*name != '[')
1227 	{
1228 		extern bool getcanonname();
1229 
1230 		if (tTd(9, 1))
1231 			printf("host_map_lookup(%s) => ", name);
1232 		s->s_namecanon.nc_flags |= NCF_VALID;		/* will be soon */
1233 		(void) strcpy(hbuf, name);
1234 		if (getcanonname(hbuf, sizeof hbuf - 1, TRUE))
1235 		{
1236 			if (tTd(9, 1))
1237 				printf("%s\n", hbuf);
1238 			cp = map_rewrite(map, hbuf, strlen(hbuf), av);
1239 			s->s_namecanon.nc_cname = newstr(cp);
1240 			return cp;
1241 		}
1242 		else
1243 		{
1244 			register struct hostent *hp;
1245 
1246 			s->s_namecanon.nc_errno = errno;
1247 #if NAMED_BIND
1248 			s->s_namecanon.nc_herrno = h_errno;
1249 			if (tTd(9, 1))
1250 				printf("FAIL (%d)\n", h_errno);
1251 			switch (h_errno)
1252 			{
1253 			  case TRY_AGAIN:
1254 				if (UseNameServer)
1255 				{
1256 					sprintf(hbuf, "%s: Name server timeout",
1257 						shortenstring(name, 33));
1258 					message("%s", hbuf);
1259 					if (CurEnv->e_message == NULL)
1260 						CurEnv->e_message = newstr(hbuf);
1261 				}
1262 				*statp = EX_TEMPFAIL;
1263 				break;
1264 
1265 			  case HOST_NOT_FOUND:
1266 				*statp = EX_NOHOST;
1267 				break;
1268 
1269 			  case NO_RECOVERY:
1270 				*statp = EX_SOFTWARE;
1271 				break;
1272 
1273 			  default:
1274 				*statp = EX_UNAVAILABLE;
1275 				break;
1276 			}
1277 #else
1278 			if (tTd(9, 1))
1279 				printf("FAIL\n");
1280 			*statp = EX_NOHOST;
1281 #endif
1282 			s->s_namecanon.nc_stat = *statp;
1283 			if (*statp != EX_TEMPFAIL || UseNameServer)
1284 				return NULL;
1285 
1286 			/*
1287 			**  Try to look it up in /etc/hosts
1288 			*/
1289 
1290 			hp = gethostbyname(name);
1291 			if (hp == NULL)
1292 			{
1293 				/* no dice there either */
1294 				s->s_namecanon.nc_stat = *statp = EX_NOHOST;
1295 				return NULL;
1296 			}
1297 
1298 			s->s_namecanon.nc_stat = *statp = EX_OK;
1299 			cp = map_rewrite(map, hp->h_name, strlen(hp->h_name), av);
1300 			s->s_namecanon.nc_cname = newstr(cp);
1301 			return cp;
1302 		}
1303 	}
1304 	if ((cp = strchr(name, ']')) == NULL)
1305 		return (NULL);
1306 	*cp = '\0';
1307 	in_addr = inet_addr(&name[1]);
1308 
1309 	/* nope -- ask the name server */
1310 	hp = gethostbyaddr((char *)&in_addr, sizeof(struct in_addr), AF_INET);
1311 	s->s_namecanon.nc_errno = errno;
1312 #if NAMED_BIND
1313 	s->s_namecanon.nc_herrno = h_errno;
1314 #endif
1315 	s->s_namecanon.nc_flags |= NCF_VALID;		/* will be soon */
1316 	if (hp == NULL)
1317 	{
1318 		s->s_namecanon.nc_stat = *statp = EX_NOHOST;
1319 		return (NULL);
1320 	}
1321 
1322 	/* found a match -- copy out */
1323 	cp = map_rewrite(map, hp->h_name, strlen(hp->h_name), av);
1324 	s->s_namecanon.nc_stat = *statp = EX_OK;
1325 	s->s_namecanon.nc_cname = newstr(cp);
1326 	return cp;
1327 }
1328 /*
1329 **  ANYNET_NTOA -- convert a network address to printable form.
1330 **
1331 **	Parameters:
1332 **		sap -- a pointer to a sockaddr structure.
1333 **
1334 **	Returns:
1335 **		A printable version of that sockaddr.
1336 */
1337 
1338 char *
anynet_ntoa(sap)1339 anynet_ntoa(sap)
1340 	register SOCKADDR *sap;
1341 {
1342 	register char *bp;
1343 	register char *ap;
1344 	int l;
1345 	static char buf[100];
1346 
1347 	/* check for null/zero family */
1348 	if (sap == NULL)
1349 		return "NULLADDR";
1350 	if (sap->sa.sa_family == 0)
1351 		return "0";
1352 
1353 	switch (sap->sa.sa_family)
1354 	{
1355 #ifdef MAYBENEXTRELEASE		/*** UNTESTED *** UNTESTED *** UNTESTED ***/
1356 #ifdef NETUNIX
1357 	  case AF_UNIX:
1358 	  	if (sap->sunix.sun_path[0] != '\0')
1359 	  		sprintf(buf, "[UNIX: %.64s]", sap->sunix.sun_path);
1360 	  	else
1361 	  		sprintf(buf, "[UNIX: localhost]");
1362 		return buf;
1363 #endif
1364 #endif
1365 
1366 #ifdef NETINET
1367 	  case AF_INET:
1368 		return inet_ntoa(((struct sockaddr_in *) sap)->sin_addr);
1369 #endif
1370 
1371 	  default:
1372 	  	/* this case is only to ensure syntactic correctness */
1373 	  	break;
1374 	}
1375 
1376 	/* unknown family -- just dump bytes */
1377 	(void) sprintf(buf, "Family %d: ", sap->sa.sa_family);
1378 	bp = &buf[strlen(buf)];
1379 	ap = sap->sa.sa_data;
1380 	for (l = sizeof sap->sa.sa_data; --l >= 0; )
1381 	{
1382 		(void) sprintf(bp, "%02x:", *ap++ & 0377);
1383 		bp += 3;
1384 	}
1385 	*--bp = '\0';
1386 	return buf;
1387 }
1388 /*
1389 **  HOSTNAMEBYANYADDR -- return name of host based on address
1390 **
1391 **	Parameters:
1392 **		sap -- SOCKADDR pointer
1393 **
1394 **	Returns:
1395 **		text representation of host name.
1396 **
1397 **	Side Effects:
1398 **		none.
1399 */
1400 
1401 char *
hostnamebyanyaddr(sap)1402 hostnamebyanyaddr(sap)
1403 	register SOCKADDR *sap;
1404 {
1405 	register struct hostent *hp;
1406 	int saveretry;
1407 
1408 #if NAMED_BIND
1409 	/* shorten name server timeout to avoid higher level timeouts */
1410 	saveretry = _res.retry;
1411 	_res.retry = 3;
1412 #endif /* NAMED_BIND */
1413 
1414 	switch (sap->sa.sa_family)
1415 	{
1416 #ifdef NETINET
1417 	  case AF_INET:
1418 		hp = gethostbyaddr((char *) &sap->sin.sin_addr,
1419 			sizeof sap->sin.sin_addr,
1420 			AF_INET);
1421 		break;
1422 #endif
1423 
1424 #ifdef NETISO
1425 	  case AF_ISO:
1426 		hp = gethostbyaddr((char *) &sap->siso.siso_addr,
1427 			sizeof sap->siso.siso_addr,
1428 			AF_ISO);
1429 		break;
1430 #endif
1431 
1432 #ifdef MAYBENEXTRELEASE		/*** UNTESTED *** UNTESTED *** UNTESTED ***/
1433 	  case AF_UNIX:
1434 		hp = NULL;
1435 		break;
1436 #endif
1437 
1438 	  default:
1439 		hp = gethostbyaddr(sap->sa.sa_data,
1440 			   sizeof sap->sa.sa_data,
1441 			   sap->sa.sa_family);
1442 		break;
1443 	}
1444 
1445 #if NAMED_BIND
1446 	_res.retry = saveretry;
1447 #endif /* NAMED_BIND */
1448 
1449 	if (hp != NULL)
1450 		return hp->h_name;
1451 	else
1452 	{
1453 		/* produce a dotted quad */
1454 		static char buf[512];
1455 
1456 		(void) sprintf(buf, "[%s]", anynet_ntoa(sap));
1457 		return buf;
1458 	}
1459 }
1460 
1461 # else /* DAEMON */
1462 /* code for systems without sophisticated networking */
1463 
1464 /*
1465 **  MYHOSTNAME -- stub version for case of no daemon code.
1466 **
1467 **	Can't convert to upper case here because might be a UUCP name.
1468 **
1469 **	Mark, you can change this to be anything you want......
1470 */
1471 
1472 char **
myhostname(hostbuf,size)1473 myhostname(hostbuf, size)
1474 	char hostbuf[];
1475 	int size;
1476 {
1477 	register FILE *f;
1478 
1479 	hostbuf[0] = '\0';
1480 	f = fopen("/usr/include/whoami", "r");
1481 	if (f != NULL)
1482 	{
1483 		(void) fgets(hostbuf, size, f);
1484 		fixcrlf(hostbuf, TRUE);
1485 		(void) fclose(f);
1486 	}
1487 	return (NULL);
1488 }
1489 /*
1490 **  GETAUTHINFO -- get the real host name asociated with a file descriptor
1491 **
1492 **	Parameters:
1493 **		fd -- the descriptor
1494 **
1495 **	Returns:
1496 **		The host name associated with this descriptor, if it can
1497 **			be determined.
1498 **		NULL otherwise.
1499 **
1500 **	Side Effects:
1501 **		none
1502 */
1503 
1504 char *
getauthinfo(fd)1505 getauthinfo(fd)
1506 	int fd;
1507 {
1508 	return NULL;
1509 }
1510 /*
1511 **  MAPHOSTNAME -- turn a hostname into canonical form
1512 **
1513 **	Parameters:
1514 **		map -- a pointer to the database map.
1515 **		name -- a buffer containing a hostname.
1516 **		avp -- a pointer to a (cf file defined) argument vector.
1517 **		statp -- an exit status (out parameter).
1518 **
1519 **	Returns:
1520 **		mapped host name
1521 **		FALSE otherwise.
1522 **
1523 **	Side Effects:
1524 **		Looks up the host specified in name.  If it is not
1525 **		the canonical name for that host, replace it with
1526 **		the canonical name.  If the name is unknown, or it
1527 **		is already the canonical name, leave it unchanged.
1528 */
1529 
1530 /*ARGSUSED*/
1531 char *
host_map_lookup(map,name,avp,statp)1532 host_map_lookup(map, name, avp, statp)
1533 	MAP *map;
1534 	char *name;
1535 	char **avp;
1536 	char *statp;
1537 {
1538 	register struct hostent *hp;
1539 
1540 	hp = gethostbyname(name);
1541 	if (hp != NULL)
1542 		return hp->h_name;
1543 	*statp = EX_NOHOST;
1544 	return NULL;
1545 }
1546 
1547 #endif /* DAEMON */
1548