xref: /original-bsd/usr.sbin/sendmail/src/daemon.c (revision d250c449)
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 <errno.h>
10 #include <signal.h>
11 #include "sendmail.h"
12 
13 #ifndef lint
14 #ifdef DAEMON
15 static char sccsid[] = "@(#)daemon.c	6.45 (Berkeley) 05/07/93 (with daemon mode)";
16 #else
17 static char sccsid[] = "@(#)daemon.c	6.45 (Berkeley) 05/07/93 (without daemon mode)";
18 #endif
19 #endif /* not lint */
20 
21 #ifdef DAEMON
22 
23 # include <netdb.h>
24 # include <sys/wait.h>
25 # include <sys/time.h>
26 
27 #ifdef NAMED_BIND
28 # include <arpa/nameser.h>
29 # include <resolv.h>
30 #endif
31 
32 /*
33 **  DAEMON.C -- routines to use when running as a daemon.
34 **
35 **	This entire file is highly dependent on the 4.2 BSD
36 **	interprocess communication primitives.  No attempt has
37 **	been made to make this file portable to Version 7,
38 **	Version 6, MPX files, etc.  If you should try such a
39 **	thing yourself, I recommend chucking the entire file
40 **	and starting from scratch.  Basic semantics are:
41 **
42 **	getrequests()
43 **		Opens a port and initiates a connection.
44 **		Returns in a child.  Must set InChannel and
45 **		OutChannel appropriately.
46 **	clrdaemon()
47 **		Close any open files associated with getting
48 **		the connection; this is used when running the queue,
49 **		etc., to avoid having extra file descriptors during
50 **		the queue run and to avoid confusing the network
51 **		code (if it cares).
52 **	makeconnection(host, port, outfile, infile, usesecureport)
53 **		Make a connection to the named host on the given
54 **		port.  Set *outfile and *infile to the files
55 **		appropriate for communication.  Returns zero on
56 **		success, else an exit status describing the
57 **		error.
58 **	maphostname(map, hbuf, hbufsiz, avp)
59 **		Convert the entry in hbuf into a canonical form.
60 */
61 
62 extern char	*anynet_ntoa();
63 /*
64 **  GETREQUESTS -- open mail IPC port and get requests.
65 **
66 **	Parameters:
67 **		none.
68 **
69 **	Returns:
70 **		none.
71 **
72 **	Side Effects:
73 **		Waits until some interesting activity occurs.  When
74 **		it does, a child is created to process it, and the
75 **		parent waits for completion.  Return from this
76 **		routine is always in the child.  The file pointers
77 **		"InChannel" and "OutChannel" should be set to point
78 **		to the communication channel.
79 */
80 
81 int		DaemonSocket	= -1;		/* fd describing socket */
82 SOCKADDR	DaemonAddr;			/* socket for incoming */
83 int		ListenQueueSize = 10;		/* size of listen queue */
84 
85 getrequests()
86 {
87 	int t;
88 	register struct servent *sp;
89 	int on = 1;
90 	bool refusingconnections = TRUE;
91 	FILE *pidf;
92 	extern void reapchild();
93 
94 	/*
95 	**  Set up the address for the mailer.
96 	*/
97 
98 	if (DaemonAddr.sin.sin_family == 0)
99 		DaemonAddr.sin.sin_family = AF_INET;
100 	if (DaemonAddr.sin.sin_addr.s_addr == 0)
101 		DaemonAddr.sin.sin_addr.s_addr = INADDR_ANY;
102 	if (DaemonAddr.sin.sin_port == 0)
103 	{
104 		sp = getservbyname("smtp", "tcp");
105 		if (sp == NULL)
106 		{
107 			syserr("554 service \"smtp\" unknown");
108 			goto severe;
109 		}
110 		DaemonAddr.sin.sin_port = sp->s_port;
111 	}
112 
113 	/*
114 	**  Try to actually open the connection.
115 	*/
116 
117 	if (tTd(15, 1))
118 		printf("getrequests: port 0x%x\n", DaemonAddr.sin.sin_port);
119 
120 	/* get a socket for the SMTP connection */
121 	DaemonSocket = socket(DaemonAddr.sa.sa_family, SOCK_STREAM, 0);
122 	if (DaemonSocket < 0)
123 	{
124 		/* probably another daemon already */
125 		syserr("getrequests: can't create socket");
126 	  severe:
127 # ifdef LOG
128 		if (LogLevel > 0)
129 			syslog(LOG_ALERT, "problem creating SMTP socket");
130 # endif /* LOG */
131 		finis();
132 	}
133 
134 	/* turn on network debugging? */
135 	if (tTd(15, 101))
136 		(void) setsockopt(DaemonSocket, SOL_SOCKET, SO_DEBUG, (char *)&on, sizeof on);
137 
138 	(void) setsockopt(DaemonSocket, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof on);
139 	(void) setsockopt(DaemonSocket, SOL_SOCKET, SO_KEEPALIVE, (char *)&on, sizeof on);
140 
141 	switch (DaemonAddr.sa.sa_family)
142 	{
143 # ifdef NETINET
144 	  case AF_INET:
145 		t = sizeof DaemonAddr.sin;
146 		break;
147 # endif
148 
149 # ifdef NETISO
150 	  case AF_ISO:
151 		t = sizeof DaemonAddr.siso;
152 		break;
153 # endif
154 
155 	  default:
156 		t = sizeof DaemonAddr;
157 		break;
158 	}
159 
160 	if (bind(DaemonSocket, &DaemonAddr.sa, t) < 0)
161 	{
162 		syserr("getrequests: cannot bind");
163 		(void) close(DaemonSocket);
164 		goto severe;
165 	}
166 
167 	(void) signal(SIGCHLD, reapchild);
168 
169 	/* write the pid to the log file for posterity */
170 	pidf = fopen(PidFile, "w");
171 	if (pidf != NULL)
172 	{
173 		fprintf(pidf, "%d\n", getpid());
174 		fclose(pidf);
175 	}
176 
177 
178 	if (tTd(15, 1))
179 		printf("getrequests: %d\n", DaemonSocket);
180 
181 	for (;;)
182 	{
183 		register int pid;
184 		auto int lotherend;
185 		extern bool refuseconnections();
186 
187 		/* see if we are rejecting connections */
188 		CurrentLA = getla();
189 		if (refuseconnections())
190 		{
191 			if (!refusingconnections)
192 			{
193 				/* don't queue so peer will fail quickly */
194 				(void) listen(DaemonSocket, 0);
195 				refusingconnections = TRUE;
196 			}
197 			setproctitle("rejecting connections: load average: %d",
198 				CurrentLA);
199 			sleep(5);
200 			continue;
201 		}
202 
203 		if (refusingconnections)
204 		{
205 			/* start listening again */
206 			if (listen(DaemonSocket, ListenQueueSize) < 0)
207 			{
208 				syserr("getrequests: cannot listen");
209 				(void) close(DaemonSocket);
210 				goto severe;
211 			}
212 			setproctitle("accepting connections");
213 			refusingconnections = FALSE;
214 		}
215 
216 		/* wait for a connection */
217 		do
218 		{
219 			errno = 0;
220 			lotherend = sizeof RealHostAddr;
221 			t = accept(DaemonSocket,
222 			    (struct sockaddr *)&RealHostAddr, &lotherend);
223 		} while (t < 0 && errno == EINTR);
224 		if (t < 0)
225 		{
226 			syserr("getrequests: accept");
227 			sleep(5);
228 			continue;
229 		}
230 
231 		/*
232 		**  Create a subprocess to process the mail.
233 		*/
234 
235 		if (tTd(15, 2))
236 			printf("getrequests: forking (fd = %d)\n", t);
237 
238 		pid = fork();
239 		if (pid < 0)
240 		{
241 			syserr("daemon: cannot fork");
242 			sleep(10);
243 			(void) close(t);
244 			continue;
245 		}
246 
247 		if (pid == 0)
248 		{
249 			extern char *hostnamebyanyaddr();
250 
251 			/*
252 			**  CHILD -- return to caller.
253 			**	Collect verified idea of sending host.
254 			**	Verify calling user id if possible here.
255 			*/
256 
257 			(void) signal(SIGCHLD, SIG_DFL);
258 			OpMode = MD_SMTP;
259 
260 			/* determine host name */
261 			RealHostName = newstr(hostnamebyanyaddr(&RealHostAddr));
262 
263 #ifdef LOG
264 			if (LogLevel > 10)
265 			{
266 				/* log connection information */
267 				syslog(LOG_INFO, "connect from %s (%s)",
268 					RealHostName, anynet_ntoa(&RealHostAddr));
269 			}
270 #endif
271 
272 			(void) close(DaemonSocket);
273 			InChannel = fdopen(t, "r");
274 			OutChannel = fdopen(dup(t), "w");
275 
276 			/* should we check for illegal connection here? XXX */
277 #ifdef XLA
278 			if (!xla_host_ok(RealHostName))
279 			{
280 				message("421 Too many SMTP sessions for this host");
281 				exit(0);
282 			}
283 #endif
284 
285 			if (tTd(15, 2))
286 				printf("getreq: returning\n");
287 			return;
288 		}
289 
290 		/* close the port so that others will hang (for a while) */
291 		(void) close(t);
292 	}
293 	/*NOTREACHED*/
294 }
295 /*
296 **  CLRDAEMON -- reset the daemon connection
297 **
298 **	Parameters:
299 **		none.
300 **
301 **	Returns:
302 **		none.
303 **
304 **	Side Effects:
305 **		releases any resources used by the passive daemon.
306 */
307 
308 clrdaemon()
309 {
310 	if (DaemonSocket >= 0)
311 		(void) close(DaemonSocket);
312 	DaemonSocket = -1;
313 }
314 /*
315 **  SETDAEMONOPTIONS -- set options for running the daemon
316 **
317 **	Parameters:
318 **		p -- the options line.
319 **
320 **	Returns:
321 **		none.
322 */
323 
324 setdaemonoptions(p)
325 	register char *p;
326 {
327 	if (DaemonAddr.sa.sa_family == AF_UNSPEC)
328 		DaemonAddr.sa.sa_family = AF_INET;
329 
330 	while (p != NULL)
331 	{
332 		register char *f;
333 		register char *v;
334 
335 		while (isascii(*p) && isspace(*p))
336 			p++;
337 		if (*p == '\0')
338 			break;
339 		f = p;
340 		p = strchr(p, ',');
341 		if (p != NULL)
342 			*p++ = '\0';
343 		v = strchr(f, '=');
344 		if (v == NULL)
345 			continue;
346 		while (isascii(*++v) && isspace(*v))
347 			continue;
348 
349 		switch (*f)
350 		{
351 		  case 'F':		/* address family */
352 			if (isascii(*v) && isdigit(*v))
353 				DaemonAddr.sa.sa_family = atoi(v);
354 #ifdef NETINET
355 			else if (strcasecmp(v, "inet") == 0)
356 				DaemonAddr.sa.sa_family = AF_INET;
357 #endif
358 #ifdef NETISO
359 			else if (strcasecmp(v, "iso") == 0)
360 				DaemonAddr.sa.sa_family = AF_ISO;
361 #endif
362 #ifdef NETNS
363 			else if (strcasecmp(v, "ns") == 0)
364 				DaemonAddr.sa.sa_family = AF_NS;
365 #endif
366 #ifdef NETX25
367 			else if (strcasecmp(v, "x.25") == 0)
368 				DaemonAddr.sa.sa_family = AF_CCITT;
369 #endif
370 			else
371 				syserr("554 Unknown address family %s in Family=option", v);
372 			break;
373 
374 		  case 'A':		/* address */
375 			switch (DaemonAddr.sa.sa_family)
376 			{
377 #ifdef NETINET
378 			  case AF_INET:
379 				if (isascii(*v) && isdigit(*v))
380 					DaemonAddr.sin.sin_addr.s_addr = inet_network(v);
381 				else
382 				{
383 					register struct netent *np;
384 
385 					np = getnetbyname(v);
386 					if (np == NULL)
387 						syserr("554 network \"%s\" unknown", v);
388 					else
389 						DaemonAddr.sin.sin_addr.s_addr = np->n_net;
390 				}
391 				break;
392 #endif
393 
394 			  default:
395 				syserr("554 Address= option unsupported for family %d",
396 					DaemonAddr.sa.sa_family);
397 				break;
398 			}
399 			break;
400 
401 		  case 'P':		/* port */
402 			switch (DaemonAddr.sa.sa_family)
403 			{
404 				short port;
405 
406 #ifdef NETINET
407 			  case AF_INET:
408 				if (isascii(*v) && isdigit(*v))
409 					DaemonAddr.sin.sin_port = atoi(v);
410 				else
411 				{
412 					register struct servent *sp;
413 
414 					sp = getservbyname(v, "tcp");
415 					if (sp == NULL)
416 						syserr("554 service \"%s\" unknown", v);
417 					else
418 						DaemonAddr.sin.sin_port = sp->s_port;
419 				}
420 				break;
421 #endif
422 
423 #ifdef NETISO
424 			  case AF_ISO:
425 				/* assume two byte transport selector */
426 				if (isascii(*v) && isdigit(*v))
427 					port = atoi(v);
428 				else
429 				{
430 					register struct servent *sp;
431 
432 					sp = getservbyname(v, "tcp");
433 					if (sp == NULL)
434 						syserr("554 service \"%s\" unknown", v);
435 					else
436 						port = sp->s_port;
437 				}
438 				bcopy((char *) &port, TSEL(&DaemonAddr.siso), 2);
439 				break;
440 #endif
441 
442 			  default:
443 				syserr("554 Port= option unsupported for family %d",
444 					DaemonAddr.sa.sa_family);
445 				break;
446 			}
447 			break;
448 
449 		  case 'L':		/* listen queue size */
450 			ListenQueueSize = atoi(v);
451 			break;
452 		}
453 	}
454 }
455 /*
456 **  MAKECONNECTION -- make a connection to an SMTP socket on another machine.
457 **
458 **	Parameters:
459 **		host -- the name of the host.
460 **		port -- the port number to connect to.
461 **		mci -- a pointer to the mail connection information
462 **			structure to be filled in.
463 **		usesecureport -- if set, use a low numbered (reserved)
464 **			port to provide some rudimentary authentication.
465 **
466 **	Returns:
467 **		An exit code telling whether the connection could be
468 **			made and if not why not.
469 **
470 **	Side Effects:
471 **		none.
472 */
473 
474 SOCKADDR	CurHostAddr;		/* address of current host */
475 
476 int
477 makeconnection(host, port, mci, usesecureport)
478 	char *host;
479 	u_short port;
480 	register MCI *mci;
481 	bool usesecureport;
482 {
483 	register int i, s;
484 	register struct hostent *hp = (struct hostent *)NULL;
485 	SOCKADDR addr;
486 	int sav_errno;
487 	int addrlen;
488 #ifdef NAMED_BIND
489 	extern int h_errno;
490 #endif
491 
492 	/*
493 	**  Set up the address for the mailer.
494 	**	Accept "[a.b.c.d]" syntax for host name.
495 	*/
496 
497 #ifdef NAMED_BIND
498 	h_errno = 0;
499 #endif
500 	errno = 0;
501 	bzero(&CurHostAddr, sizeof CurHostAddr);
502 	CurHostName = host;
503 
504 	if (host[0] == '[')
505 	{
506 		long hid;
507 		register char *p = strchr(host, ']');
508 
509 		if (p != NULL)
510 		{
511 			*p = '\0';
512 			hid = inet_addr(&host[1]);
513 			if (hid == -1)
514 			{
515 				/* try it as a host name (avoid MX lookup) */
516 				hp = gethostbyname(&host[1]);
517 				*p = ']';
518 				goto gothostent;
519 			}
520 			*p = ']';
521 		}
522 		if (p == NULL)
523 		{
524 			usrerr("553 Invalid numeric domain spec \"%s\"", host);
525 			return (EX_NOHOST);
526 		}
527 		addr.sin.sin_family = AF_INET;
528 		addr.sin.sin_addr.s_addr = hid;
529 	}
530 	else
531 	{
532 		hp = gethostbyname(host);
533 gothostent:
534 		if (hp == NULL)
535 		{
536 #ifdef NAMED_BIND
537 			if (errno == ETIMEDOUT || h_errno == TRY_AGAIN)
538 				return (EX_TEMPFAIL);
539 
540 			/* if name server is specified, assume temp fail */
541 			if (errno == ECONNREFUSED && UseNameServer)
542 				return (EX_TEMPFAIL);
543 #endif
544 			return (EX_NOHOST);
545 		}
546 		addr.sa.sa_family = hp->h_addrtype;
547 		switch (hp->h_addrtype)
548 		{
549 #ifdef NETINET
550 		  case AF_INET:
551 			bcopy(hp->h_addr,
552 				&addr.sin.sin_addr,
553 				hp->h_length);
554 			break;
555 #endif
556 
557 		  default:
558 			bcopy(hp->h_addr,
559 				addr.sa.sa_data,
560 				hp->h_length);
561 			break;
562 		}
563 		i = 1;
564 	}
565 
566 	/*
567 	**  Determine the port number.
568 	*/
569 
570 	if (port != 0)
571 		port = htons(port);
572 	else
573 	{
574 		register struct servent *sp = getservbyname("smtp", "tcp");
575 
576 		if (sp == NULL)
577 		{
578 			syserr("554 makeconnection: service \"smtp\" unknown");
579 			return (EX_OSERR);
580 		}
581 		port = sp->s_port;
582 	}
583 
584 	switch (addr.sa.sa_family)
585 	{
586 	  case AF_INET:
587 		addr.sin.sin_port = port;
588 		addrlen = sizeof (struct sockaddr_in);
589 		break;
590 
591 #ifdef NETISO
592 	  case AF_ISO:
593 		/* assume two byte transport selector */
594 		bcopy((char *) &port, TSEL((struct sockaddr_iso *) &addr), 2);
595 		addrlen = sizeof (struct sockaddr_iso);
596 		break;
597 #endif
598 
599 	  default:
600 		syserr("Can't connect to address family %d", addr.sa.sa_family);
601 		return (EX_NOHOST);
602 	}
603 
604 	/*
605 	**  Try to actually open the connection.
606 	*/
607 
608 #ifdef XLA
609 	/* if too many connections, don't bother trying */
610 	if (!xla_noqueue_ok(host))
611 		return EX_TEMPFAIL;
612 #endif
613 
614 	for (;;)
615 	{
616 		if (tTd(16, 1))
617 			printf("makeconnection (%s [%s])\n",
618 				host, anynet_ntoa(&addr));
619 
620 		/* save for logging */
621 		CurHostAddr = addr;
622 
623 		if (usesecureport)
624 		{
625 			int rport = IPPORT_RESERVED - 1;
626 
627 			s = rresvport(&rport);
628 		}
629 		else
630 		{
631 			s = socket(AF_INET, SOCK_STREAM, 0);
632 		}
633 		if (s < 0)
634 		{
635 			sav_errno = errno;
636 			syserr("makeconnection: no socket");
637 			goto failure;
638 		}
639 
640 		if (tTd(16, 1))
641 			printf("makeconnection: fd=%d\n", s);
642 
643 		/* turn on network debugging? */
644 		if (tTd(16, 101))
645 		{
646 			int on = 1;
647 			(void) setsockopt(DaemonSocket, SOL_SOCKET, SO_DEBUG,
648 					  (char *)&on, sizeof on);
649 		}
650 		if (CurEnv->e_xfp != NULL)
651 			(void) fflush(CurEnv->e_xfp);		/* for debugging */
652 		errno = 0;					/* for debugging */
653 		if (connect(s, (struct sockaddr *) &addr, addrlen) >= 0)
654 			break;
655 
656 		/* couldn't connect.... figure out why */
657 		sav_errno = errno;
658 		(void) close(s);
659 		if (hp && hp->h_addr_list[i])
660 		{
661 			extern char *errstring();
662 
663 			if (tTd(16, 1))
664 				printf("Connect failed (%s); trying new address....\n",
665 					errstring(sav_errno));
666 			switch (addr.sa.sa_family)
667 			{
668 #ifdef NETINET
669 			  case AF_INET:
670 				bcopy(hp->h_addr_list[i++],
671 				      &addr.sin.sin_addr,
672 				      hp->h_length);
673 				break;
674 #endif
675 
676 			  default:
677 				bcopy(hp->h_addr_list[i++],
678 					addr.sa.sa_data,
679 					hp->h_length);
680 				break;
681 			}
682 			continue;
683 		}
684 
685 		/* failure, decide if temporary or not */
686 	failure:
687 #ifdef XLA
688 		xla_host_end(host);
689 #endif
690 		if (transienterror(sav_errno))
691 			return EX_TEMPFAIL;
692 		else
693 		{
694 			extern char *errstring();
695 
696 			message("%s", errstring(sav_errno));
697 			return (EX_UNAVAILABLE);
698 		}
699 	}
700 
701 	/* connection ok, put it into canonical form */
702 	mci->mci_out = fdopen(s, "w");
703 	mci->mci_in = fdopen(dup(s), "r");
704 
705 	return (EX_OK);
706 }
707 /*
708 **  MYHOSTNAME -- return the name of this host.
709 **
710 **	Parameters:
711 **		hostbuf -- a place to return the name of this host.
712 **		size -- the size of hostbuf.
713 **
714 **	Returns:
715 **		A list of aliases for this host.
716 **
717 **	Side Effects:
718 **		Sets the MyIpAddrs buffer to a list of my IP addresses.
719 */
720 
721 struct in_addr	MyIpAddrs[MAXIPADDR + 1];
722 
723 char **
724 myhostname(hostbuf, size)
725 	char hostbuf[];
726 	int size;
727 {
728 	register struct hostent *hp;
729 	extern struct hostent *gethostbyname();
730 
731 	if (gethostname(hostbuf, size) < 0)
732 	{
733 		(void) strcpy(hostbuf, "localhost");
734 	}
735 	hp = gethostbyname(hostbuf);
736 	if (hp != NULL)
737 	{
738 		(void) strncpy(hostbuf, hp->h_name, size - 1);
739 		hostbuf[size - 1] = '\0';
740 
741 		if (hp->h_addrtype == AF_INET && hp->h_length == 4)
742 		{
743 			register int i;
744 
745 			for (i = 0; i < MAXIPADDR; i++)
746 			{
747 				if (hp->h_addr_list[i] == NULL)
748 					break;
749 				MyIpAddrs[i].s_addr = *(u_long *) hp->h_addr_list[i];
750 			}
751 			MyIpAddrs[i].s_addr = 0;
752 		}
753 
754 		return (hp->h_aliases);
755 	}
756 	else
757 		return (NULL);
758 }
759 /*
760 **  GETAUTHINFO -- get the real host name asociated with a file descriptor
761 **
762 **	Uses RFC1413 protocol to try to get info from the other end.
763 **
764 **	Parameters:
765 **		fd -- the descriptor
766 **
767 **	Returns:
768 **		The user@host information associated with this descriptor.
769 **
770 **	Side Effects:
771 **		Sets RealHostName to the name of the host at the other end.
772 */
773 
774 #ifdef IDENTPROTO
775 
776 static jmp_buf	CtxAuthTimeout;
777 
778 static
779 authtimeout()
780 {
781 	longjmp(CtxAuthTimeout, 1);
782 }
783 
784 #endif
785 
786 char *
787 getauthinfo(fd)
788 	int fd;
789 {
790 	SOCKADDR fa;
791 	int falen;
792 	register char *p;
793 #ifdef IDENTPROTO
794 	SOCKADDR la;
795 	int lalen;
796 	register struct servent *sp;
797 	int s;
798 	int i;
799 	EVENT *ev;
800 #endif
801 	static char hbuf[MAXNAME * 2 + 2];
802 	extern char *hostnamebyanyaddr();
803 	extern char RealUserName[];			/* main.c */
804 
805 	falen = sizeof fa;
806 	if (getpeername(fd, &fa.sa, &falen) < 0 || falen <= 0)
807 	{
808 		RealHostName = "localhost";
809 		(void) sprintf(hbuf, "%s@localhost", RealUserName);
810 		if (tTd(9, 1))
811 			printf("getauthinfo: %s\n", hbuf);
812 		return hbuf;
813 	}
814 
815 	RealHostName = newstr(hostnamebyanyaddr(&fa));
816 	RealHostAddr = fa;
817 
818 #ifdef IDENTPROTO
819 	lalen = sizeof la;
820 	if (fa.sa.sa_family != AF_INET ||
821 	    getsockname(fd, &la.sa, &lalen) < 0 || lalen <= 0 ||
822 	    la.sa.sa_family != AF_INET)
823 	{
824 		/* no ident info */
825 		goto noident;
826 	}
827 
828 	/* create ident query */
829 	(void) sprintf(hbuf, "%d,%d\r\n", fa.sin.sin_port, la.sin.sin_port);
830 
831 	/* create local address */
832 	bzero(&la, sizeof la);
833 
834 	/* create foreign address */
835 	sp = getservbyname("auth", "tcp");
836 	if (sp != NULL)
837 		fa.sin.sin_port = sp->s_port;
838 	else
839 		fa.sin.sin_port = htons(113);
840 
841 	s = -1;
842 	if (setjmp(CtxAuthTimeout) != 0)
843 	{
844 		if (s >= 0)
845 			(void) close(s);
846 		goto noident;
847 	}
848 
849 	/* put a timeout around the whole thing */
850 	ev = setevent((time_t) 30, authtimeout, 0);
851 
852 	/* connect to foreign IDENT server */
853 	s = socket(AF_INET, SOCK_STREAM, 0);
854 	if (s < 0)
855 	{
856 		clrevent(ev);
857 		goto noident;
858 	}
859 	if (connect(s, &fa.sa, sizeof fa.sin) < 0)
860 	{
861 closeident:
862 		(void) close(s);
863 		clrevent(ev);
864 		goto noident;
865 	}
866 
867 	if (tTd(9, 10))
868 		printf("getauthinfo: sent %s", hbuf);
869 
870 	/* send query */
871 	if (write(s, hbuf, strlen(hbuf)) < 0)
872 		goto closeident;
873 
874 	/* get result */
875 	i = read(s, hbuf, sizeof hbuf);
876 	(void) close(s);
877 	clrevent(ev);
878 	if (i <= 0)
879 		goto noident;
880 	if (hbuf[--i] == '\n' && hbuf[--i] == '\r')
881 		i--;
882 	hbuf[++i] = '\0';
883 
884 	if (tTd(9, 3))
885 		printf("getauthinfo:  got %s\n", hbuf);
886 
887 	/* parse result */
888 	p = strchr(hbuf, ':');
889 	if (p == NULL)
890 	{
891 		/* malformed response */
892 		goto noident;
893 	}
894 	while (isascii(*++p) && isspace(*p))
895 		continue;
896 	if (strncasecmp(p, "userid", 6) != 0)
897 	{
898 		/* presumably an error string */
899 		goto noident;
900 	}
901 	p += 6;
902 	while (isascii(*p) && isspace(*p))
903 		p++;
904 	if (*p++ != ':')
905 	{
906 		/* either useridxx or malformed response */
907 		goto noident;
908 	}
909 
910 	/* p now points to the OSTYPE field */
911 	p = strchr(p, ':');
912 	if (p == NULL)
913 	{
914 		/* malformed response */
915 		goto noident;
916 	}
917 
918 	/* 1413 says don't do this -- but it's broken otherwise */
919 	while (isascii(*++p) && isspace(*p))
920 		continue;
921 
922 	/* p now points to the authenticated name */
923 	(void) sprintf(hbuf, "%s@%s", p, RealHostName);
924 	goto finish;
925 
926 #endif /* IDENTPROTO */
927 
928 noident:
929 	(void) strcpy(hbuf, RealHostName);
930 
931 finish:
932 	if (RealHostName[0] != '[')
933 	{
934 		p = &hbuf[strlen(hbuf)];
935 		(void) sprintf(p, " [%s]", anynet_ntoa(&RealHostAddr));
936 	}
937 	if (tTd(9, 1))
938 		printf("getauthinfo: %s\n", hbuf);
939 	return hbuf;
940 }
941 /*
942 **  MAPHOSTNAME -- turn a hostname into canonical form
943 **
944 **	Parameters:
945 **		map -- a pointer to this map (unused).
946 **		hbuf -- a buffer containing a hostname.
947 **		hbsize -- the size of hbuf.
948 **		avp -- unused -- for compatibility with other mapping
949 **			functions.
950 **		statp -- an exit status (out parameter) -- set to
951 **			EX_TEMPFAIL if the name server is unavailable.
952 **
953 **	Returns:
954 **		The mapping, if found.
955 **		NULL if no mapping found.
956 **
957 **	Side Effects:
958 **		Looks up the host specified in hbuf.  If it is not
959 **		the canonical name for that host, return the canonical
960 **		name.
961 */
962 
963 char *
964 maphostname(map, hbuf, hbsize, avp, statp)
965 	MAP *map;
966 	char *hbuf;
967 	int hbsize;
968 	char **avp;
969 	int *statp;
970 {
971 	register struct hostent *hp;
972 	u_long in_addr;
973 	char *cp;
974 	int i;
975 	register STAB *s;
976 	extern struct hostent *gethostbyaddr();
977 	extern int h_errno;
978 
979 	/* allow room for null */
980 	hbsize--;
981 
982 	/*
983 	**  See if we have already looked up this name.  If so, just
984 	**  return it.
985 	*/
986 
987 	s = stab(hbuf, ST_NAMECANON, ST_ENTER);
988 	if (bitset(NCF_VALID, s->s_namecanon.nc_flags))
989 	{
990 		errno = s->s_namecanon.nc_errno;
991 		h_errno = s->s_namecanon.nc_herrno;
992 		*statp = s->s_namecanon.nc_stat;
993 		return s->s_namecanon.nc_cname;
994 	}
995 
996 	/*
997 	**  If first character is a bracket, then it is an address
998 	**  lookup.  Address is copied into a temporary buffer to
999 	**  strip the brackets and to preserve hbuf if address is
1000 	**  unknown.
1001 	*/
1002 
1003 	if (*hbuf != '[')
1004 	{
1005 		extern bool getcanonname();
1006 
1007 		if (tTd(9, 1))
1008 			printf("maphostname(%s, %d) => ", hbuf, hbsize);
1009 		s->s_namecanon.nc_flags |= NCF_VALID;		/* will be soon */
1010 		if (getcanonname(hbuf, hbsize))
1011 		{
1012 			if (tTd(9, 1))
1013 				printf("%s\n", hbuf);
1014 			s->s_namecanon.nc_cname = newstr(hbuf);
1015 			return hbuf;
1016 		}
1017 		else
1018 		{
1019 			register struct hostent *hp;
1020 
1021 			if (tTd(9, 1))
1022 				printf("FAIL (%d)\n", h_errno);
1023 			s->s_namecanon.nc_errno = errno;
1024 			s->s_namecanon.nc_herrno = h_errno;
1025 			switch (h_errno)
1026 			{
1027 			  case TRY_AGAIN:
1028 				if (UseNameServer)
1029 				{
1030 					char *msg = "Recipient domain nameserver timed out";
1031 
1032 					message(msg);
1033 					if (CurEnv->e_message == NULL)
1034 						CurEnv->e_message = msg;
1035 				}
1036 				*statp = EX_TEMPFAIL;
1037 				break;
1038 
1039 			  case HOST_NOT_FOUND:
1040 				*statp = EX_NOHOST;
1041 				break;
1042 
1043 			  case NO_RECOVERY:
1044 				*statp = EX_SOFTWARE;
1045 				break;
1046 
1047 			  default:
1048 				*statp = EX_UNAVAILABLE;
1049 				break;
1050 			}
1051 			s->s_namecanon.nc_stat = *statp;
1052 			if (*statp != EX_TEMPFAIL || UseNameServer)
1053 				return NULL;
1054 
1055 			/*
1056 			**  Try to look it up in /etc/hosts
1057 			*/
1058 
1059 			hp = gethostbyname(hbuf);
1060 			if (hp == NULL)
1061 			{
1062 				/* no dice there either */
1063 				s->s_namecanon.nc_stat = *statp = EX_NOHOST;
1064 				return NULL;
1065 			}
1066 
1067 			s->s_namecanon.nc_stat = *statp = EX_OK;
1068 			s->s_namecanon.nc_cname = newstr(hp->h_name);
1069 			return hp->h_name;
1070 		}
1071 	}
1072 	if ((cp = strchr(hbuf, ']')) == NULL)
1073 		return (NULL);
1074 	*cp = '\0';
1075 	in_addr = inet_addr(&hbuf[1]);
1076 
1077 	/* check to see if this is one of our addresses */
1078 	for (i = 0; MyIpAddrs[i].s_addr != 0; i++)
1079 	{
1080 		if (MyIpAddrs[i].s_addr == in_addr)
1081 		{
1082 			strncpy(hbuf, MyHostName, hbsize);
1083 			hbuf[hbsize] = '\0';
1084 			return hbuf;
1085 		}
1086 	}
1087 
1088 	/* nope -- ask the name server */
1089 	hp = gethostbyaddr((char *)&in_addr, sizeof(struct in_addr), AF_INET);
1090 	s->s_namecanon.nc_errno = errno;
1091 	s->s_namecanon.nc_herrno = h_errno;
1092 	s->s_namecanon.nc_flags |= NCF_VALID;		/* will be soon */
1093 	if (hp == NULL)
1094 	{
1095 		s->s_namecanon.nc_stat = *statp = EX_NOHOST;
1096 		return (NULL);
1097 	}
1098 
1099 	/* found a match -- copy out */
1100 	s->s_namecanon.nc_cname = newstr(hp->h_name);
1101 	if (strlen(hp->h_name) > hbsize)
1102 		hp->h_name[hbsize] = '\0';
1103 	(void) strcpy(hbuf, hp->h_name);
1104 	s->s_namecanon.nc_stat = *statp = EX_OK;
1105 	return hbuf;
1106 }
1107 /*
1108 **  ANYNET_NTOA -- convert a network address to printable form.
1109 **
1110 **	Parameters:
1111 **		sap -- a pointer to a sockaddr structure.
1112 **
1113 **	Returns:
1114 **		A printable version of that sockaddr.
1115 */
1116 
1117 char *
1118 anynet_ntoa(sap)
1119 	register SOCKADDR *sap;
1120 {
1121 	register char *bp;
1122 	register char *ap;
1123 	int l;
1124 	static char buf[80];
1125 
1126 	/* check for null/zero family */
1127 	if (sap == NULL)
1128 		return "NULLADDR";
1129 	if (sap->sa.sa_family == 0)
1130 		return "0";
1131 
1132 #ifdef NETINET
1133 	if (sap->sa.sa_family == AF_INET)
1134 	{
1135 		extern char *inet_ntoa();
1136 
1137 		return inet_ntoa(((struct sockaddr_in *) sap)->sin_addr);
1138 	}
1139 #endif
1140 
1141 	/* unknown family -- just dump bytes */
1142 	(void) sprintf(buf, "Family %d: ", sap->sa.sa_family);
1143 	bp = &buf[strlen(buf)];
1144 	ap = sap->sa.sa_data;
1145 	for (l = sizeof sap->sa.sa_data; --l >= 0; )
1146 	{
1147 		(void) sprintf(bp, "%02x:", *ap++ & 0377);
1148 		bp += 3;
1149 	}
1150 	*--bp = '\0';
1151 	return buf;
1152 }
1153 /*
1154 **  HOSTNAMEBYANYADDR -- return name of host based on address
1155 **
1156 **	Parameters:
1157 **		sap -- SOCKADDR pointer
1158 **
1159 **	Returns:
1160 **		text representation of host name.
1161 **
1162 **	Side Effects:
1163 **		none.
1164 */
1165 
1166 char *
1167 hostnamebyanyaddr(sap)
1168 	register SOCKADDR *sap;
1169 {
1170 	register struct hostent *hp;
1171 
1172 #ifdef NAMED_BIND
1173 	int saveretry;
1174 
1175 	/* shorten name server timeout to avoid higher level timeouts */
1176 	saveretry = _res.retry;
1177 	_res.retry = 3;
1178 #endif /* NAMED_BIND */
1179 
1180 	switch (sap->sa.sa_family)
1181 	{
1182 #ifdef NETINET
1183 	  case AF_INET:
1184 		hp = gethostbyaddr((char *) &sap->sin.sin_addr,
1185 			sizeof sap->sin.sin_addr,
1186 			AF_INET);
1187 		break;
1188 #endif
1189 
1190 #ifdef NETISO
1191 	  case AF_ISO:
1192 		hp = gethostbyaddr((char *) &sap->siso.siso_addr,
1193 			sizeof sap->siso.siso_addr,
1194 			AF_ISO);
1195 		break;
1196 #endif
1197 
1198 	  default:
1199 		hp = gethostbyaddr(sap->sa.sa_data,
1200 			   sizeof sap->sa.sa_data,
1201 			   sap->sa.sa_family);
1202 		break;
1203 	}
1204 
1205 #ifdef NAMED_BIND
1206 	_res.retry = saveretry;
1207 #endif /* NAMED_BIND */
1208 
1209 	if (hp != NULL)
1210 		return hp->h_name;
1211 	else
1212 	{
1213 		/* produce a dotted quad */
1214 		static char buf[512];
1215 
1216 		(void) sprintf(buf, "[%s]", anynet_ntoa(sap));
1217 		return buf;
1218 	}
1219 }
1220 
1221 # else /* DAEMON */
1222 /* code for systems without sophisticated networking */
1223 
1224 /*
1225 **  MYHOSTNAME -- stub version for case of no daemon code.
1226 **
1227 **	Can't convert to upper case here because might be a UUCP name.
1228 **
1229 **	Mark, you can change this to be anything you want......
1230 */
1231 
1232 char **
1233 myhostname(hostbuf, size)
1234 	char hostbuf[];
1235 	int size;
1236 {
1237 	register FILE *f;
1238 
1239 	hostbuf[0] = '\0';
1240 	f = fopen("/usr/include/whoami", "r");
1241 	if (f != NULL)
1242 	{
1243 		(void) fgets(hostbuf, size, f);
1244 		fixcrlf(hostbuf, TRUE);
1245 		(void) fclose(f);
1246 	}
1247 	return (NULL);
1248 }
1249 /*
1250 **  GETAUTHINFO -- get the real host name asociated with a file descriptor
1251 **
1252 **	Parameters:
1253 **		fd -- the descriptor
1254 **
1255 **	Returns:
1256 **		The host name associated with this descriptor, if it can
1257 **			be determined.
1258 **		NULL otherwise.
1259 **
1260 **	Side Effects:
1261 **		none
1262 */
1263 
1264 char *
1265 getauthinfo(fd)
1266 	int fd;
1267 {
1268 	return NULL;
1269 }
1270 /*
1271 **  MAPHOSTNAME -- turn a hostname into canonical form
1272 **
1273 **	Parameters:
1274 **		map -- a pointer to the database map.
1275 **		hbuf -- a buffer containing a hostname.
1276 **		hbsize -- size of hbuf.
1277 **		avp -- a pointer to a (cf file defined) argument vector.
1278 **		statp -- an exit status (out parameter).
1279 **
1280 **	Returns:
1281 **		mapped host name
1282 **		FALSE otherwise.
1283 **
1284 **	Side Effects:
1285 **		Looks up the host specified in hbuf.  If it is not
1286 **		the canonical name for that host, replace it with
1287 **		the canonical name.  If the name is unknown, or it
1288 **		is already the canonical name, leave it unchanged.
1289 */
1290 
1291 /*ARGSUSED*/
1292 char *
1293 maphostname(map, hbuf, hbsize, avp, statp)
1294 	MAP *map;
1295 	char *hbuf;
1296 	int hbsize;
1297 	char **avp;
1298 	char *statp;
1299 {
1300 	register struct hostent *hp;
1301 
1302 	hp = gethostbyname(hbuf);
1303 	if (hp != NULL)
1304 		return hp->h_name;
1305 	*statp = EX_NOHOST;
1306 	return NULL;
1307 }
1308 
1309 #endif /* DAEMON */
1310