xref: /original-bsd/usr.sbin/sendmail/src/daemon.c (revision 95ecee29)
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  * %sccs.include.redist.c%
7  */
8 
9 #include <errno.h>
10 #include "sendmail.h"
11 
12 #ifndef lint
13 #ifdef DAEMON
14 static char sccsid[] = "@(#)daemon.c	8.26 (Berkeley) 11/25/93 (with daemon mode)";
15 #else
16 static char sccsid[] = "@(#)daemon.c	8.26 (Berkeley) 11/25/93 (without daemon mode)";
17 #endif
18 #endif /* not lint */
19 
20 #ifdef DAEMON
21 
22 # include <netdb.h>
23 # include <sys/time.h>
24 # include <arpa/inet.h>
25 
26 #ifdef NAMED_BIND
27 # include <arpa/nameser.h>
28 # include <resolv.h>
29 #endif
30 
31 /*
32 **  DAEMON.C -- routines to use when running as a daemon.
33 **
34 **	This entire file is highly dependent on the 4.2 BSD
35 **	interprocess communication primitives.  No attempt has
36 **	been made to make this file portable to Version 7,
37 **	Version 6, MPX files, etc.  If you should try such a
38 **	thing yourself, I recommend chucking the entire file
39 **	and starting from scratch.  Basic semantics are:
40 **
41 **	getrequests()
42 **		Opens a port and initiates a connection.
43 **		Returns in a child.  Must set InChannel and
44 **		OutChannel appropriately.
45 **	clrdaemon()
46 **		Close any open files associated with getting
47 **		the connection; this is used when running the queue,
48 **		etc., to avoid having extra file descriptors during
49 **		the queue run and to avoid confusing the network
50 **		code (if it cares).
51 **	makeconnection(host, port, outfile, infile, usesecureport)
52 **		Make a connection to the named host on the given
53 **		port.  Set *outfile and *infile to the files
54 **		appropriate for communication.  Returns zero on
55 **		success, else an exit status describing the
56 **		error.
57 **	host_map_lookup(map, hbuf, avp, pstat)
58 **		Convert the entry in hbuf into a canonical form.
59 */
60 /*
61 **  GETREQUESTS -- open mail IPC port and get requests.
62 **
63 **	Parameters:
64 **		none.
65 **
66 **	Returns:
67 **		none.
68 **
69 **	Side Effects:
70 **		Waits until some interesting activity occurs.  When
71 **		it does, a child is created to process it, and the
72 **		parent waits for completion.  Return from this
73 **		routine is always in the child.  The file pointers
74 **		"InChannel" and "OutChannel" should be set to point
75 **		to the communication channel.
76 */
77 
78 int		DaemonSocket	= -1;		/* fd describing socket */
79 SOCKADDR	DaemonAddr;			/* socket for incoming */
80 int		ListenQueueSize = 10;		/* size of listen queue */
81 int		TcpRcvBufferSize = 0;		/* size of TCP receive buffer */
82 int		TcpSndBufferSize = 0;		/* size of TCP send buffer */
83 
84 getrequests()
85 {
86 	int t;
87 	register struct servent *sp;
88 	int on = 1;
89 	bool refusingconnections = TRUE;
90 	FILE *pidf;
91 	int socksize;
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 #ifdef SO_RCVBUF
142 	if (TcpRcvBufferSize > 0)
143 	{
144 		if (setsockopt(DaemonSocket, SOL_SOCKET, SO_RCVBUF,
145 			       (char *) &TcpRcvBufferSize,
146 			       sizeof(TcpRcvBufferSize)) < 0)
147 			syserr("getrequests: setsockopt(SO_RCVBUF)");
148 	}
149 #endif
150 
151 	switch (DaemonAddr.sa.sa_family)
152 	{
153 # ifdef NETINET
154 	  case AF_INET:
155 		socksize = sizeof DaemonAddr.sin;
156 		break;
157 # endif
158 
159 # ifdef NETISO
160 	  case AF_ISO:
161 		socksize = sizeof DaemonAddr.siso;
162 		break;
163 # endif
164 
165 	  default:
166 		socksize = sizeof DaemonAddr;
167 		break;
168 	}
169 
170 	if (bind(DaemonSocket, &DaemonAddr.sa, socksize) < 0)
171 	{
172 		syserr("getrequests: cannot bind");
173 		(void) close(DaemonSocket);
174 		goto severe;
175 	}
176 
177 	(void) setsignal(SIGCHLD, reapchild);
178 
179 	/* write the pid to the log file for posterity */
180 	pidf = fopen(PidFile, "w");
181 	if (pidf != NULL)
182 	{
183 		extern char *CommandLineArgs;
184 
185 		/* write the process id on line 1 */
186 		fprintf(pidf, "%d\n", getpid());
187 
188 		/* line 2 contains all command line flags */
189 		fprintf(pidf, "%s\n", CommandLineArgs);
190 
191 		/* flush and close */
192 		fclose(pidf);
193 	}
194 
195 
196 	if (tTd(15, 1))
197 		printf("getrequests: %d\n", DaemonSocket);
198 
199 	for (;;)
200 	{
201 		register int pid;
202 		auto int lotherend;
203 		extern bool refuseconnections();
204 
205 		/* see if we are rejecting connections */
206 		CurrentLA = getla();
207 		if (refuseconnections())
208 		{
209 			if (!refusingconnections)
210 			{
211 				/* don't queue so peer will fail quickly */
212 				(void) listen(DaemonSocket, 0);
213 				refusingconnections = TRUE;
214 			}
215 			setproctitle("rejecting connections: load average: %d",
216 				CurrentLA);
217 			sleep(5);
218 			continue;
219 		}
220 
221 		if (refusingconnections)
222 		{
223 			/* start listening again */
224 			if (listen(DaemonSocket, ListenQueueSize) < 0)
225 			{
226 				syserr("getrequests: cannot listen");
227 				(void) close(DaemonSocket);
228 				goto severe;
229 			}
230 			setproctitle("accepting connections");
231 			refusingconnections = FALSE;
232 		}
233 
234 		/* wait for a connection */
235 		do
236 		{
237 			errno = 0;
238 			lotherend = socksize;
239 			t = accept(DaemonSocket,
240 			    (struct sockaddr *)&RealHostAddr, &lotherend);
241 		} while (t < 0 && errno == EINTR);
242 		if (t < 0)
243 		{
244 			syserr("getrequests: accept");
245 			sleep(5);
246 			continue;
247 		}
248 
249 		/*
250 		**  Create a subprocess to process the mail.
251 		*/
252 
253 		if (tTd(15, 2))
254 			printf("getrequests: forking (fd = %d)\n", t);
255 
256 		pid = fork();
257 		if (pid < 0)
258 		{
259 			syserr("daemon: cannot fork");
260 			sleep(10);
261 			(void) close(t);
262 			continue;
263 		}
264 
265 		if (pid == 0)
266 		{
267 			char *p;
268 			extern char *hostnamebyanyaddr();
269 
270 			/*
271 			**  CHILD -- return to caller.
272 			**	Collect verified idea of sending host.
273 			**	Verify calling user id if possible here.
274 			*/
275 
276 			(void) setsignal(SIGCHLD, SIG_DFL);
277 			OpMode = MD_SMTP;
278 
279 			/* determine host name */
280 			p = hostnamebyanyaddr(&RealHostAddr);
281 			RealHostName = newstr(p);
282 
283 #ifdef LOG
284 			if (LogLevel > 11)
285 			{
286 				/* log connection information */
287 				syslog(LOG_INFO, "connect from %s (%s)",
288 					RealHostName, anynet_ntoa(&RealHostAddr));
289 			}
290 #endif
291 
292 			(void) close(DaemonSocket);
293 			if ((InChannel = fdopen(t, "r")) == NULL ||
294 			    (t = dup(t)) < 0 ||
295 			    (OutChannel = fdopen(t, "w")) == NULL)
296 			{
297 				syserr("cannot open SMTP server channel, fd=%d", t);
298 				exit(0);
299 			}
300 
301 			/* should we check for illegal connection here? XXX */
302 #ifdef XLA
303 			if (!xla_host_ok(RealHostName))
304 			{
305 				message("421 Too many SMTP sessions for this host");
306 				exit(0);
307 			}
308 #endif
309 
310 			if (tTd(15, 2))
311 				printf("getreq: returning\n");
312 			return;
313 		}
314 
315 		/* close the port so that others will hang (for a while) */
316 		(void) close(t);
317 	}
318 	/*NOTREACHED*/
319 }
320 /*
321 **  CLRDAEMON -- reset the daemon connection
322 **
323 **	Parameters:
324 **		none.
325 **
326 **	Returns:
327 **		none.
328 **
329 **	Side Effects:
330 **		releases any resources used by the passive daemon.
331 */
332 
333 clrdaemon()
334 {
335 	if (DaemonSocket >= 0)
336 		(void) close(DaemonSocket);
337 	DaemonSocket = -1;
338 }
339 /*
340 **  SETDAEMONOPTIONS -- set options for running the daemon
341 **
342 **	Parameters:
343 **		p -- the options line.
344 **
345 **	Returns:
346 **		none.
347 */
348 
349 setdaemonoptions(p)
350 	register char *p;
351 {
352 	if (DaemonAddr.sa.sa_family == AF_UNSPEC)
353 		DaemonAddr.sa.sa_family = AF_INET;
354 
355 	while (p != NULL)
356 	{
357 		register char *f;
358 		register char *v;
359 
360 		while (isascii(*p) && isspace(*p))
361 			p++;
362 		if (*p == '\0')
363 			break;
364 		f = p;
365 		p = strchr(p, ',');
366 		if (p != NULL)
367 			*p++ = '\0';
368 		v = strchr(f, '=');
369 		if (v == NULL)
370 			continue;
371 		while (isascii(*++v) && isspace(*v))
372 			continue;
373 
374 		switch (*f)
375 		{
376 		  case 'F':		/* address family */
377 			if (isascii(*v) && isdigit(*v))
378 				DaemonAddr.sa.sa_family = atoi(v);
379 #ifdef NETINET
380 			else if (strcasecmp(v, "inet") == 0)
381 				DaemonAddr.sa.sa_family = AF_INET;
382 #endif
383 #ifdef NETISO
384 			else if (strcasecmp(v, "iso") == 0)
385 				DaemonAddr.sa.sa_family = AF_ISO;
386 #endif
387 #ifdef NETNS
388 			else if (strcasecmp(v, "ns") == 0)
389 				DaemonAddr.sa.sa_family = AF_NS;
390 #endif
391 #ifdef NETX25
392 			else if (strcasecmp(v, "x.25") == 0)
393 				DaemonAddr.sa.sa_family = AF_CCITT;
394 #endif
395 			else
396 				syserr("554 Unknown address family %s in Family=option", v);
397 			break;
398 
399 		  case 'A':		/* address */
400 			switch (DaemonAddr.sa.sa_family)
401 			{
402 #ifdef NETINET
403 			  case AF_INET:
404 				if (isascii(*v) && isdigit(*v))
405 					DaemonAddr.sin.sin_addr.s_addr = inet_network(v);
406 				else
407 				{
408 					register struct netent *np;
409 
410 					np = getnetbyname(v);
411 					if (np == NULL)
412 						syserr("554 network \"%s\" unknown", v);
413 					else
414 						DaemonAddr.sin.sin_addr.s_addr = np->n_net;
415 				}
416 				break;
417 #endif
418 
419 			  default:
420 				syserr("554 Address= option unsupported for family %d",
421 					DaemonAddr.sa.sa_family);
422 				break;
423 			}
424 			break;
425 
426 		  case 'P':		/* port */
427 			switch (DaemonAddr.sa.sa_family)
428 			{
429 				short port;
430 
431 #ifdef NETINET
432 			  case AF_INET:
433 				if (isascii(*v) && isdigit(*v))
434 					DaemonAddr.sin.sin_port = htons(atoi(v));
435 				else
436 				{
437 					register struct servent *sp;
438 
439 					sp = getservbyname(v, "tcp");
440 					if (sp == NULL)
441 						syserr("554 service \"%s\" unknown", v);
442 					else
443 						DaemonAddr.sin.sin_port = sp->s_port;
444 				}
445 				break;
446 #endif
447 
448 #ifdef NETISO
449 			  case AF_ISO:
450 				/* assume two byte transport selector */
451 				if (isascii(*v) && isdigit(*v))
452 					port = htons(atoi(v));
453 				else
454 				{
455 					register struct servent *sp;
456 
457 					sp = getservbyname(v, "tcp");
458 					if (sp == NULL)
459 						syserr("554 service \"%s\" unknown", v);
460 					else
461 						port = sp->s_port;
462 				}
463 				bcopy((char *) &port, TSEL(&DaemonAddr.siso), 2);
464 				break;
465 #endif
466 
467 			  default:
468 				syserr("554 Port= option unsupported for family %d",
469 					DaemonAddr.sa.sa_family);
470 				break;
471 			}
472 			break;
473 
474 		  case 'L':		/* listen queue size */
475 			ListenQueueSize = atoi(v);
476 			break;
477 
478 		  case 'S':		/* send buffer size */
479 			TcpSndBufferSize = atoi(v);
480 			break;
481 
482 		  case 'R':		/* receive buffer size */
483 			TcpRcvBufferSize = atoi(v);
484 			break;
485 		}
486 	}
487 }
488 /*
489 **  MAKECONNECTION -- make a connection to an SMTP socket on another machine.
490 **
491 **	Parameters:
492 **		host -- the name of the host.
493 **		port -- the port number to connect to.
494 **		mci -- a pointer to the mail connection information
495 **			structure to be filled in.
496 **		usesecureport -- if set, use a low numbered (reserved)
497 **			port to provide some rudimentary authentication.
498 **
499 **	Returns:
500 **		An exit code telling whether the connection could be
501 **			made and if not why not.
502 **
503 **	Side Effects:
504 **		none.
505 */
506 
507 SOCKADDR	CurHostAddr;		/* address of current host */
508 
509 int
510 makeconnection(host, port, mci, usesecureport)
511 	char *host;
512 	u_short port;
513 	register MCI *mci;
514 	bool usesecureport;
515 {
516 	register int i, s;
517 	register struct hostent *hp = (struct hostent *)NULL;
518 	SOCKADDR addr;
519 	int sav_errno;
520 	int addrlen;
521 #ifdef NAMED_BIND
522 	extern int h_errno;
523 #endif
524 
525 	/*
526 	**  Set up the address for the mailer.
527 	**	Accept "[a.b.c.d]" syntax for host name.
528 	*/
529 
530 #ifdef NAMED_BIND
531 	h_errno = 0;
532 #endif
533 	errno = 0;
534 	bzero(&CurHostAddr, sizeof CurHostAddr);
535 	SmtpPhase = mci->mci_phase = "initial connection";
536 	CurHostName = host;
537 
538 	if (host[0] == '[')
539 	{
540 		long hid;
541 		register char *p = strchr(host, ']');
542 
543 		if (p != NULL)
544 		{
545 			*p = '\0';
546 #ifdef NETINET
547 			hid = inet_addr(&host[1]);
548 			if (hid == -1)
549 #endif
550 			{
551 				/* try it as a host name (avoid MX lookup) */
552 				hp = gethostbyname(&host[1]);
553 				*p = ']';
554 				goto gothostent;
555 			}
556 			*p = ']';
557 		}
558 		if (p == NULL)
559 		{
560 			usrerr("553 Invalid numeric domain spec \"%s\"", host);
561 			return (EX_NOHOST);
562 		}
563 #ifdef NETINET
564 		addr.sin.sin_family = AF_INET;		/*XXX*/
565 		addr.sin.sin_addr.s_addr = hid;
566 #endif
567 	}
568 	else
569 	{
570 		hp = gethostbyname(host);
571 gothostent:
572 		if (hp == NULL)
573 		{
574 #ifdef NAMED_BIND
575 			if (errno == ETIMEDOUT || h_errno == TRY_AGAIN)
576 				return (EX_TEMPFAIL);
577 
578 			/* if name server is specified, assume temp fail */
579 			if (errno == ECONNREFUSED && UseNameServer)
580 				return (EX_TEMPFAIL);
581 #endif
582 			return (EX_NOHOST);
583 		}
584 		addr.sa.sa_family = hp->h_addrtype;
585 		switch (hp->h_addrtype)
586 		{
587 #ifdef NETINET
588 		  case AF_INET:
589 			bcopy(hp->h_addr,
590 				&addr.sin.sin_addr,
591 				sizeof addr.sin.sin_addr);
592 			break;
593 #endif
594 
595 		  default:
596 			bcopy(hp->h_addr,
597 				addr.sa.sa_data,
598 				hp->h_length);
599 			break;
600 		}
601 		i = 1;
602 	}
603 
604 	/*
605 	**  Determine the port number.
606 	*/
607 
608 	if (port != 0)
609 		port = htons(port);
610 	else
611 	{
612 		register struct servent *sp = getservbyname("smtp", "tcp");
613 
614 		if (sp == NULL)
615 		{
616 			syserr("554 makeconnection: service \"smtp\" unknown");
617 			return (EX_OSERR);
618 		}
619 		port = sp->s_port;
620 	}
621 
622 	switch (addr.sa.sa_family)
623 	{
624 #ifdef NETINET
625 	  case AF_INET:
626 		addr.sin.sin_port = port;
627 		addrlen = sizeof (struct sockaddr_in);
628 		break;
629 #endif
630 
631 #ifdef NETISO
632 	  case AF_ISO:
633 		/* assume two byte transport selector */
634 		bcopy((char *) &port, TSEL((struct sockaddr_iso *) &addr), 2);
635 		addrlen = sizeof (struct sockaddr_iso);
636 		break;
637 #endif
638 
639 	  default:
640 		syserr("Can't connect to address family %d", addr.sa.sa_family);
641 		return (EX_NOHOST);
642 	}
643 
644 	/*
645 	**  Try to actually open the connection.
646 	*/
647 
648 #ifdef XLA
649 	/* if too many connections, don't bother trying */
650 	if (!xla_noqueue_ok(host))
651 		return EX_TEMPFAIL;
652 #endif
653 
654 	for (;;)
655 	{
656 		if (tTd(16, 1))
657 			printf("makeconnection (%s [%s])\n",
658 				host, anynet_ntoa(&addr));
659 
660 		/* save for logging */
661 		CurHostAddr = addr;
662 
663 		if (usesecureport)
664 		{
665 			int rport = IPPORT_RESERVED - 1;
666 
667 			s = rresvport(&rport);
668 		}
669 		else
670 		{
671 			s = socket(AF_INET, SOCK_STREAM, 0);
672 		}
673 		if (s < 0)
674 		{
675 			sav_errno = errno;
676 			syserr("makeconnection: no socket");
677 			goto failure;
678 		}
679 
680 #ifdef SO_SNDBUF
681 		if (TcpSndBufferSize > 0)
682 		{
683 			if (setsockopt(s, SOL_SOCKET, SO_SNDBUF,
684 				       (char *) &TcpSndBufferSize,
685 				       sizeof(TcpSndBufferSize)) < 0)
686 				syserr("makeconnection: setsockopt(SO_SNDBUF)");
687 		}
688 #endif
689 
690 		if (tTd(16, 1))
691 			printf("makeconnection: fd=%d\n", s);
692 
693 		/* turn on network debugging? */
694 		if (tTd(16, 101))
695 		{
696 			int on = 1;
697 			(void) setsockopt(DaemonSocket, SOL_SOCKET, SO_DEBUG,
698 					  (char *)&on, sizeof on);
699 		}
700 		if (CurEnv->e_xfp != NULL)
701 			(void) fflush(CurEnv->e_xfp);		/* for debugging */
702 		errno = 0;					/* for debugging */
703 		if (connect(s, (struct sockaddr *) &addr, addrlen) >= 0)
704 			break;
705 
706 		/* couldn't connect.... figure out why */
707 		sav_errno = errno;
708 		(void) close(s);
709 		if (hp && hp->h_addr_list[i])
710 		{
711 			if (tTd(16, 1))
712 				printf("Connect failed (%s); trying new address....\n",
713 					errstring(sav_errno));
714 			switch (addr.sa.sa_family)
715 			{
716 #ifdef NETINET
717 			  case AF_INET:
718 				bcopy(hp->h_addr_list[i++],
719 				      &addr.sin.sin_addr,
720 				      sizeof addr.sin.sin_addr);
721 				break;
722 #endif
723 
724 			  default:
725 				bcopy(hp->h_addr_list[i++],
726 					addr.sa.sa_data,
727 					hp->h_length);
728 				break;
729 			}
730 			continue;
731 		}
732 
733 		/* failure, decide if temporary or not */
734 	failure:
735 #ifdef XLA
736 		xla_host_end(host);
737 #endif
738 		if (transienterror(sav_errno))
739 			return EX_TEMPFAIL;
740 		else
741 		{
742 			message("%s", errstring(sav_errno));
743 			return (EX_UNAVAILABLE);
744 		}
745 	}
746 
747 	/* connection ok, put it into canonical form */
748 	if ((mci->mci_out = fdopen(s, "w")) == NULL ||
749 	    (s = dup(s)) < 0 ||
750 	    (mci->mci_in = fdopen(s, "r")) == NULL)
751 	{
752 		syserr("cannot open SMTP client channel, fd=%d", s);
753 		return EX_TEMPFAIL;
754 	}
755 
756 	return (EX_OK);
757 }
758 /*
759 **  MYHOSTNAME -- return the name of this host.
760 **
761 **	Parameters:
762 **		hostbuf -- a place to return the name of this host.
763 **		size -- the size of hostbuf.
764 **
765 **	Returns:
766 **		A list of aliases for this host.
767 **
768 **	Side Effects:
769 **		Adds numeric codes to $=w.
770 */
771 
772 char **
773 myhostname(hostbuf, size)
774 	char hostbuf[];
775 	int size;
776 {
777 	register struct hostent *hp;
778 	extern struct hostent *gethostbyname();
779 
780 	if (gethostname(hostbuf, size) < 0)
781 	{
782 		(void) strcpy(hostbuf, "localhost");
783 	}
784 	hp = gethostbyname(hostbuf);
785 	if (hp != NULL)
786 	{
787 		(void) strncpy(hostbuf, hp->h_name, size - 1);
788 		hostbuf[size - 1] = '\0';
789 
790 		if (hp->h_addrtype == AF_INET && hp->h_length == 4)
791 		{
792 			register int i;
793 
794 			for (i = 0; hp->h_addr_list[i] != NULL; i++)
795 			{
796 				char ipbuf[100];
797 
798 				sprintf(ipbuf, "[%s]",
799 					inet_ntoa(*((struct in_addr *) hp->h_addr_list[i])));
800 				setclass('w', ipbuf);
801 			}
802 		}
803 
804 		return (hp->h_aliases);
805 	}
806 	else
807 		return (NULL);
808 }
809 /*
810 **  GETAUTHINFO -- get the real host name asociated with a file descriptor
811 **
812 **	Uses RFC1413 protocol to try to get info from the other end.
813 **
814 **	Parameters:
815 **		fd -- the descriptor
816 **
817 **	Returns:
818 **		The user@host information associated with this descriptor.
819 **
820 **	Side Effects:
821 **		Sets RealHostName to the name of the host at the other end.
822 */
823 
824 #if IDENTPROTO
825 
826 static jmp_buf	CtxAuthTimeout;
827 
828 static
829 authtimeout()
830 {
831 	longjmp(CtxAuthTimeout, 1);
832 }
833 
834 #endif
835 
836 char *
837 getauthinfo(fd)
838 	int fd;
839 {
840 	SOCKADDR fa;
841 	int falen;
842 	register char *p;
843 #if IDENTPROTO
844 	SOCKADDR la;
845 	int lalen;
846 	register struct servent *sp;
847 	int s;
848 	int i;
849 	EVENT *ev;
850 #endif
851 	static char hbuf[MAXNAME * 2 + 2];
852 	extern char *hostnamebyanyaddr();
853 	extern char RealUserName[];			/* main.c */
854 
855 	falen = sizeof fa;
856 	if (getpeername(fd, &fa.sa, &falen) < 0 || falen <= 0 ||
857 	    fa.sa.sa_family == 0)
858 	{
859 		RealHostName = "localhost";
860 		(void) sprintf(hbuf, "%s@localhost", RealUserName);
861 		if (tTd(9, 1))
862 			printf("getauthinfo: %s\n", hbuf);
863 		return hbuf;
864 	}
865 
866 	p = hostnamebyanyaddr(&fa);
867 	RealHostName = newstr(p);
868 	RealHostAddr = fa;
869 
870 #if IDENTPROTO
871 	lalen = sizeof la;
872 	if (fa.sa.sa_family != AF_INET ||
873 	    getsockname(fd, &la.sa, &lalen) < 0 || lalen <= 0 ||
874 	    la.sa.sa_family != AF_INET)
875 	{
876 		/* no ident info */
877 		goto noident;
878 	}
879 
880 	/* create ident query */
881 	(void) sprintf(hbuf, "%d,%d\r\n",
882 		ntohs(fa.sin.sin_port), ntohs(la.sin.sin_port));
883 
884 	/* create local address */
885 	la.sin.sin_port = 0;
886 
887 	/* create foreign address */
888 	sp = getservbyname("auth", "tcp");
889 	if (sp != NULL)
890 		fa.sin.sin_port = sp->s_port;
891 	else
892 		fa.sin.sin_port = htons(113);
893 
894 	s = -1;
895 	if (setjmp(CtxAuthTimeout) != 0)
896 	{
897 		if (s >= 0)
898 			(void) close(s);
899 		goto noident;
900 	}
901 
902 	/* put a timeout around the whole thing */
903 	ev = setevent(TimeOuts.to_ident, authtimeout, 0);
904 
905 	/* connect to foreign IDENT server using same address as SMTP socket */
906 	s = socket(AF_INET, SOCK_STREAM, 0);
907 	if (s < 0)
908 	{
909 		clrevent(ev);
910 		goto noident;
911 	}
912 	if (bind(s, &la.sa, sizeof la.sin) < 0 ||
913 	    connect(s, &fa.sa, sizeof fa.sin) < 0)
914 	{
915 closeident:
916 		(void) close(s);
917 		clrevent(ev);
918 		goto noident;
919 	}
920 
921 	if (tTd(9, 10))
922 		printf("getauthinfo: sent %s", hbuf);
923 
924 	/* send query */
925 	if (write(s, hbuf, strlen(hbuf)) < 0)
926 		goto closeident;
927 
928 	/* get result */
929 	i = read(s, hbuf, sizeof hbuf);
930 	(void) close(s);
931 	clrevent(ev);
932 	if (i <= 0)
933 		goto noident;
934 	if (hbuf[--i] == '\n' && hbuf[--i] == '\r')
935 		i--;
936 	hbuf[++i] = '\0';
937 
938 	if (tTd(9, 3))
939 		printf("getauthinfo:  got %s\n", hbuf);
940 
941 	/* parse result */
942 	p = strchr(hbuf, ':');
943 	if (p == NULL)
944 	{
945 		/* malformed response */
946 		goto noident;
947 	}
948 	while (isascii(*++p) && isspace(*p))
949 		continue;
950 	if (strncasecmp(p, "userid", 6) != 0)
951 	{
952 		/* presumably an error string */
953 		goto noident;
954 	}
955 	p += 6;
956 	while (isascii(*p) && isspace(*p))
957 		p++;
958 	if (*p++ != ':')
959 	{
960 		/* either useridxx or malformed response */
961 		goto noident;
962 	}
963 
964 	/* p now points to the OSTYPE field */
965 	p = strchr(p, ':');
966 	if (p == NULL)
967 	{
968 		/* malformed response */
969 		goto noident;
970 	}
971 
972 	/* 1413 says don't do this -- but it's broken otherwise */
973 	while (isascii(*++p) && isspace(*p))
974 		continue;
975 
976 	/* p now points to the authenticated name */
977 	(void) sprintf(hbuf, "%s@%s", p, RealHostName);
978 	goto finish;
979 
980 #endif /* IDENTPROTO */
981 
982 noident:
983 	(void) strcpy(hbuf, RealHostName);
984 
985 finish:
986 	if (RealHostName[0] != '[')
987 	{
988 		p = &hbuf[strlen(hbuf)];
989 		(void) sprintf(p, " [%s]", anynet_ntoa(&RealHostAddr));
990 	}
991 	if (tTd(9, 1))
992 		printf("getauthinfo: %s\n", hbuf);
993 	return hbuf;
994 }
995 /*
996 **  HOST_MAP_LOOKUP -- turn a hostname into canonical form
997 **
998 **	Parameters:
999 **		map -- a pointer to this map (unused).
1000 **		name -- the (presumably unqualified) hostname.
1001 **		av -- unused -- for compatibility with other mapping
1002 **			functions.
1003 **		statp -- an exit status (out parameter) -- set to
1004 **			EX_TEMPFAIL if the name server is unavailable.
1005 **
1006 **	Returns:
1007 **		The mapping, if found.
1008 **		NULL if no mapping found.
1009 **
1010 **	Side Effects:
1011 **		Looks up the host specified in hbuf.  If it is not
1012 **		the canonical name for that host, return the canonical
1013 **		name.
1014 */
1015 
1016 char *
1017 host_map_lookup(map, name, av, statp)
1018 	MAP *map;
1019 	char *name;
1020 	char **av;
1021 	int *statp;
1022 {
1023 	register struct hostent *hp;
1024 	u_long in_addr;
1025 	char *cp;
1026 	int i;
1027 	register STAB *s;
1028 	char *timeoutmsg = "Recipient domain nameserver timed out";
1029 	char hbuf[MAXNAME];
1030 	extern struct hostent *gethostbyaddr();
1031 	extern int h_errno;
1032 
1033 	/*
1034 	**  See if we have already looked up this name.  If so, just
1035 	**  return it.
1036 	*/
1037 
1038 	s = stab(name, ST_NAMECANON, ST_ENTER);
1039 	if (bitset(NCF_VALID, s->s_namecanon.nc_flags))
1040 	{
1041 		if (tTd(9, 1))
1042 			printf("host_map_lookup(%s) => CACHE %s\n",
1043 				name, s->s_namecanon.nc_cname);
1044 		errno = s->s_namecanon.nc_errno;
1045 		h_errno = s->s_namecanon.nc_herrno;
1046 		*statp = s->s_namecanon.nc_stat;
1047 		if (CurEnv->e_message == NULL && *statp == EX_TEMPFAIL)
1048 			CurEnv->e_message = newstr(timeoutmsg);
1049 		return s->s_namecanon.nc_cname;
1050 	}
1051 
1052 	/*
1053 	**  If first character is a bracket, then it is an address
1054 	**  lookup.  Address is copied into a temporary buffer to
1055 	**  strip the brackets and to preserve name if address is
1056 	**  unknown.
1057 	*/
1058 
1059 	if (*name != '[')
1060 	{
1061 		extern bool getcanonname();
1062 
1063 		if (tTd(9, 1))
1064 			printf("host_map_lookup(%s) => ", name);
1065 		s->s_namecanon.nc_flags |= NCF_VALID;		/* will be soon */
1066 		(void) strcpy(hbuf, name);
1067 		if (getcanonname(hbuf, sizeof hbuf - 1, TRUE))
1068 		{
1069 			if (tTd(9, 1))
1070 				printf("%s\n", hbuf);
1071 			cp = map_rewrite(map, hbuf, strlen(hbuf), av);
1072 			s->s_namecanon.nc_cname = newstr(cp);
1073 			return cp;
1074 		}
1075 		else
1076 		{
1077 			register struct hostent *hp;
1078 
1079 			if (tTd(9, 1))
1080 				printf("FAIL (%d)\n", h_errno);
1081 			s->s_namecanon.nc_errno = errno;
1082 			s->s_namecanon.nc_herrno = h_errno;
1083 			switch (h_errno)
1084 			{
1085 			  case TRY_AGAIN:
1086 				if (UseNameServer)
1087 				{
1088 					message(timeoutmsg);
1089 					if (CurEnv->e_message == NULL)
1090 						CurEnv->e_message = newstr(timeoutmsg);
1091 				}
1092 				*statp = EX_TEMPFAIL;
1093 				break;
1094 
1095 			  case HOST_NOT_FOUND:
1096 				*statp = EX_NOHOST;
1097 				break;
1098 
1099 			  case NO_RECOVERY:
1100 				*statp = EX_SOFTWARE;
1101 				break;
1102 
1103 			  default:
1104 				*statp = EX_UNAVAILABLE;
1105 				break;
1106 			}
1107 			s->s_namecanon.nc_stat = *statp;
1108 			if (*statp != EX_TEMPFAIL || UseNameServer)
1109 				return NULL;
1110 
1111 			/*
1112 			**  Try to look it up in /etc/hosts
1113 			*/
1114 
1115 			hp = gethostbyname(name);
1116 			if (hp == NULL)
1117 			{
1118 				/* no dice there either */
1119 				s->s_namecanon.nc_stat = *statp = EX_NOHOST;
1120 				return NULL;
1121 			}
1122 
1123 			s->s_namecanon.nc_stat = *statp = EX_OK;
1124 			cp = map_rewrite(map, hp->h_name, strlen(hp->h_name), av);
1125 			s->s_namecanon.nc_cname = newstr(cp);
1126 			return cp;
1127 		}
1128 	}
1129 	if ((cp = strchr(name, ']')) == NULL)
1130 		return (NULL);
1131 	*cp = '\0';
1132 	in_addr = inet_addr(&name[1]);
1133 
1134 	/* nope -- ask the name server */
1135 	hp = gethostbyaddr((char *)&in_addr, sizeof(struct in_addr), AF_INET);
1136 	s->s_namecanon.nc_errno = errno;
1137 	s->s_namecanon.nc_herrno = h_errno;
1138 	s->s_namecanon.nc_flags |= NCF_VALID;		/* will be soon */
1139 	if (hp == NULL)
1140 	{
1141 		s->s_namecanon.nc_stat = *statp = EX_NOHOST;
1142 		return (NULL);
1143 	}
1144 
1145 	/* found a match -- copy out */
1146 	cp = map_rewrite(map, hp->h_name, strlen(hp->h_name), av);
1147 	s->s_namecanon.nc_stat = *statp = EX_OK;
1148 	s->s_namecanon.nc_cname = newstr(cp);
1149 	return cp;
1150 }
1151 /*
1152 **  ANYNET_NTOA -- convert a network address to printable form.
1153 **
1154 **	Parameters:
1155 **		sap -- a pointer to a sockaddr structure.
1156 **
1157 **	Returns:
1158 **		A printable version of that sockaddr.
1159 */
1160 
1161 char *
1162 anynet_ntoa(sap)
1163 	register SOCKADDR *sap;
1164 {
1165 	register char *bp;
1166 	register char *ap;
1167 	int l;
1168 	static char buf[100];
1169 
1170 	/* check for null/zero family */
1171 	if (sap == NULL)
1172 		return "NULLADDR";
1173 	if (sap->sa.sa_family == 0)
1174 		return "0";
1175 
1176 	switch (sap->sa.sa_family)
1177 	{
1178 #ifdef MAYBENEXTRELEASE		/*** UNTESTED *** UNTESTED *** UNTESTED ***/
1179 #ifdef NETUNIX
1180 	  case AF_UNIX:
1181 	  	if (sap->sunix.sun_path[0] != '\0')
1182 	  		sprintf(buf, "[UNIX: %.64s]", sap->sunix.sun_path);
1183 	  	else
1184 	  		sprintf(buf, "[UNIX: localhost]");
1185 		return buf;
1186 #endif
1187 #endif
1188 
1189 #ifdef NETINET
1190 	  case AF_INET:
1191 		return inet_ntoa(((struct sockaddr_in *) sap)->sin_addr);
1192 #endif
1193 
1194 	  default:
1195 	  	/* this case is only to ensure syntactic correctness */
1196 	  	break;
1197 	}
1198 
1199 	/* unknown family -- just dump bytes */
1200 	(void) sprintf(buf, "Family %d: ", sap->sa.sa_family);
1201 	bp = &buf[strlen(buf)];
1202 	ap = sap->sa.sa_data;
1203 	for (l = sizeof sap->sa.sa_data; --l >= 0; )
1204 	{
1205 		(void) sprintf(bp, "%02x:", *ap++ & 0377);
1206 		bp += 3;
1207 	}
1208 	*--bp = '\0';
1209 	return buf;
1210 }
1211 /*
1212 **  HOSTNAMEBYANYADDR -- return name of host based on address
1213 **
1214 **	Parameters:
1215 **		sap -- SOCKADDR pointer
1216 **
1217 **	Returns:
1218 **		text representation of host name.
1219 **
1220 **	Side Effects:
1221 **		none.
1222 */
1223 
1224 char *
1225 hostnamebyanyaddr(sap)
1226 	register SOCKADDR *sap;
1227 {
1228 	register struct hostent *hp;
1229 	int saveretry;
1230 
1231 #ifdef NAMED_BIND
1232 	/* shorten name server timeout to avoid higher level timeouts */
1233 	saveretry = _res.retry;
1234 	_res.retry = 3;
1235 #endif /* NAMED_BIND */
1236 
1237 	switch (sap->sa.sa_family)
1238 	{
1239 #ifdef NETINET
1240 	  case AF_INET:
1241 		hp = gethostbyaddr((char *) &sap->sin.sin_addr,
1242 			sizeof sap->sin.sin_addr,
1243 			AF_INET);
1244 		break;
1245 #endif
1246 
1247 #ifdef NETISO
1248 	  case AF_ISO:
1249 		hp = gethostbyaddr((char *) &sap->siso.siso_addr,
1250 			sizeof sap->siso.siso_addr,
1251 			AF_ISO);
1252 		break;
1253 #endif
1254 
1255 #ifdef MAYBENEXTRELEASE		/*** UNTESTED *** UNTESTED *** UNTESTED ***/
1256 	  case AF_UNIX:
1257 		hp = NULL;
1258 		break;
1259 #endif
1260 
1261 	  default:
1262 		hp = gethostbyaddr(sap->sa.sa_data,
1263 			   sizeof sap->sa.sa_data,
1264 			   sap->sa.sa_family);
1265 		break;
1266 	}
1267 
1268 #ifdef NAMED_BIND
1269 	_res.retry = saveretry;
1270 #endif /* NAMED_BIND */
1271 
1272 	if (hp != NULL)
1273 		return hp->h_name;
1274 	else
1275 	{
1276 		/* produce a dotted quad */
1277 		static char buf[512];
1278 
1279 		(void) sprintf(buf, "[%s]", anynet_ntoa(sap));
1280 		return buf;
1281 	}
1282 }
1283 
1284 # else /* DAEMON */
1285 /* code for systems without sophisticated networking */
1286 
1287 /*
1288 **  MYHOSTNAME -- stub version for case of no daemon code.
1289 **
1290 **	Can't convert to upper case here because might be a UUCP name.
1291 **
1292 **	Mark, you can change this to be anything you want......
1293 */
1294 
1295 char **
1296 myhostname(hostbuf, size)
1297 	char hostbuf[];
1298 	int size;
1299 {
1300 	register FILE *f;
1301 
1302 	hostbuf[0] = '\0';
1303 	f = fopen("/usr/include/whoami", "r");
1304 	if (f != NULL)
1305 	{
1306 		(void) fgets(hostbuf, size, f);
1307 		fixcrlf(hostbuf, TRUE);
1308 		(void) fclose(f);
1309 	}
1310 	return (NULL);
1311 }
1312 /*
1313 **  GETAUTHINFO -- get the real host name asociated with a file descriptor
1314 **
1315 **	Parameters:
1316 **		fd -- the descriptor
1317 **
1318 **	Returns:
1319 **		The host name associated with this descriptor, if it can
1320 **			be determined.
1321 **		NULL otherwise.
1322 **
1323 **	Side Effects:
1324 **		none
1325 */
1326 
1327 char *
1328 getauthinfo(fd)
1329 	int fd;
1330 {
1331 	return NULL;
1332 }
1333 /*
1334 **  MAPHOSTNAME -- turn a hostname into canonical form
1335 **
1336 **	Parameters:
1337 **		map -- a pointer to the database map.
1338 **		name -- a buffer containing a hostname.
1339 **		avp -- a pointer to a (cf file defined) argument vector.
1340 **		statp -- an exit status (out parameter).
1341 **
1342 **	Returns:
1343 **		mapped host name
1344 **		FALSE otherwise.
1345 **
1346 **	Side Effects:
1347 **		Looks up the host specified in name.  If it is not
1348 **		the canonical name for that host, replace it with
1349 **		the canonical name.  If the name is unknown, or it
1350 **		is already the canonical name, leave it unchanged.
1351 */
1352 
1353 /*ARGSUSED*/
1354 char *
1355 host_map_lookup(map, name, avp, statp)
1356 	MAP *map;
1357 	char *name;
1358 	char **avp;
1359 	char *statp;
1360 {
1361 	register struct hostent *hp;
1362 
1363 	hp = gethostbyname(name);
1364 	if (hp != NULL)
1365 		return hp->h_name;
1366 	*statp = EX_NOHOST;
1367 	return NULL;
1368 }
1369 
1370 #endif /* DAEMON */
1371