xref: /netbsd-src/usr.sbin/inetd/inetd.c (revision f5d3fbbc6ff4a77159fb268d247bd94cb7d7e332)
1 /*	$NetBSD: inetd.c,v 1.38 1997/10/17 13:53:30 lukem Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1991, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT("@(#) Copyright (c) 1983, 1991, 1993, 1994\n\
39 	The Regents of the University of California.  All rights reserved.\n");
40 #if 0
41 static char sccsid[] = "@(#)inetd.c	8.4 (Berkeley) 4/13/94";
42 #else
43 __RCSID("$NetBSD: inetd.c,v 1.38 1997/10/17 13:53:30 lukem Exp $");
44 #endif
45 #endif /* not lint */
46 
47 /*
48  * Inetd - Internet super-server
49  *
50  * This program invokes all internet services as needed.  Connection-oriented
51  * services are invoked each time a connection is made, by creating a process.
52  * This process is passed the connection as file descriptor 0 and is expected
53  * to do a getpeername to find out the source host and port.
54  *
55  * Datagram oriented services are invoked when a datagram
56  * arrives; a process is created and passed a pending message
57  * on file descriptor 0.  Datagram servers may either connect
58  * to their peer, freeing up the original socket for inetd
59  * to receive further messages on, or ``take over the socket'',
60  * processing all arriving datagrams and, eventually, timing
61  * out.	 The first type of server is said to be ``multi-threaded'';
62  * the second type of server ``single-threaded''.
63  *
64  * Inetd uses a configuration file which is read at startup
65  * and, possibly, at some later time in response to a hangup signal.
66  * The configuration file is ``free format'' with fields given in the
67  * order shown below.  Continuation lines for an entry must being with
68  * a space or tab.  All fields must be present in each entry.
69  *
70  *	service name			must be in /etc/services or must
71  *					name a tcpmux service
72  *	socket type			stream/dgram/raw/rdm/seqpacket
73  *	protocol			must be in /etc/protocols
74  *	wait/nowait[.max]		single-threaded/multi-threaded, max #
75  *	user[.group]			user/group to run daemon as
76  *	server program			full path name
77  *	server program arguments	maximum of MAXARGS (20)
78  *
79  * For RPC services
80  *      service name/version            must be in /etc/rpc
81  *	socket type			stream/dgram/raw/rdm/seqpacket
82  *	protocol			must be in /etc/protocols
83  *	wait/nowait[.max]		single-threaded/multi-threaded
84  *	user[.group]			user to run daemon as
85  *	server program			full path name
86  *	server program arguments	maximum of MAXARGS (20)
87  *
88  * For non-RPC services, the "service name" can be of the form
89  * hostaddress:servicename, in which case the hostaddress is used
90  * as the host portion of the address to listen on.  If hostaddress
91  * consists of a single `*' character, INADDR_ANY is used.
92  *
93  * A line can also consist of just
94  *	hostaddress:
95  * where hostaddress is as in the preceding paragraph.  Such a line must
96  * have no further fields; the specified hostaddress is remembered and
97  * used for all further lines that have no hostaddress specified,
98  * until the next such line (or EOF).  (This is why * is provided to
99  * allow explicit specification of INADDR_ANY.)  A line
100  *	*:
101  * is implicitly in effect at the beginning of the file.
102  *
103  * The hostaddress specifier may (and often will) contain dots;
104  * the service name must not.
105  *
106  * For RPC services, host-address specifiers are accepted and will
107  * work to some extent; however, because of limitations in the
108  * portmapper interface, it will not work to try to give more than
109  * one line for any given RPC service, even if the host-address
110  * specifiers are different.
111  *
112  * TCP services without official port numbers are handled with the
113  * RFC1078-based tcpmux internal service. Tcpmux listens on port 1 for
114  * requests. When a connection is made from a foreign host, the service
115  * requested is passed to tcpmux, which looks it up in the servtab list
116  * and returns the proper entry for the service. Tcpmux returns a
117  * negative reply if the service doesn't exist, otherwise the invoked
118  * server is expected to return the positive reply if the service type in
119  * inetd.conf file has the prefix "tcpmux/". If the service type has the
120  * prefix "tcpmux/+", tcpmux will return the positive reply for the
121  * process; this is for compatibility with older server code, and also
122  * allows you to invoke programs that use stdin/stdout without putting any
123  * special server code in them. Services that use tcpmux are "nowait"
124  * because they do not have a well-known port and hence cannot listen
125  * for new requests.
126  *
127  * Comment lines are indicated by a `#' in column 1.
128  */
129 
130 /*
131  * Here's the scoop concerning the user.group feature:
132  *
133  * 1) set-group-option off.
134  *
135  * 	a) user = root:	NO setuid() or setgid() is done
136  *
137  * 	b) other:	setuid()
138  * 			setgid(primary group as found in passwd)
139  * 			initgroups(name, primary group)
140  *
141  * 2) set-group-option on.
142  *
143  * 	a) user = root:	NO setuid()
144  * 			setgid(specified group)
145  * 			NO initgroups()
146  *
147  * 	b) other:	setuid()
148  * 			setgid(specified group)
149  * 			initgroups(name, specified group)
150  *
151  */
152 
153 #include <sys/param.h>
154 #include <sys/stat.h>
155 #include <sys/ioctl.h>
156 #include <sys/socket.h>
157 #include <sys/un.h>
158 #include <sys/wait.h>
159 #include <sys/time.h>
160 #include <sys/resource.h>
161 
162 #ifndef RLIMIT_NOFILE
163 #define RLIMIT_NOFILE	RLIMIT_OFILE
164 #endif
165 
166 #define RPC
167 
168 #include <netinet/in.h>
169 #include <arpa/inet.h>
170 #ifdef RPC
171 #include <rpc/rpc.h>
172 #include <rpc/pmap_clnt.h>
173 #endif
174 
175 #include <errno.h>
176 #include <fcntl.h>
177 #include <grp.h>
178 #include <netdb.h>
179 #include <pwd.h>
180 #include <signal.h>
181 #include <stdio.h>
182 #include <stdlib.h>
183 #include <string.h>
184 #include <syslog.h>
185 #include <unistd.h>
186 
187 #include "pathnames.h"
188 
189 #ifdef LIBWRAP
190 # include <tcpd.h>
191 #ifndef LIBWRAP_ALLOW_FACILITY
192 # define LIBWRAP_ALLOW_FACILITY LOG_AUTH
193 #endif
194 #ifndef LIBWRAP_ALLOW_SEVERITY
195 # define LIBWRAP_ALLOW_SEVERITY LOG_INFO
196 #endif
197 #ifndef LIBWRAP_DENY_FACILITY
198 # define LIBWRAP_DENY_FACILITY LOG_AUTH
199 #endif
200 #ifndef LIBWRAP_DENY_SEVERITY
201 # define LIBWRAP_DENY_SEVERITY LOG_WARNING
202 #endif
203 int allow_severity = LIBWRAP_ALLOW_FACILITY|LIBWRAP_ALLOW_SEVERITY;
204 int deny_severity = LIBWRAP_DENY_FACILITY|LIBWRAP_DENY_SEVERITY;
205 #endif
206 
207 #define	TOOMANY		40		/* don't start more than TOOMANY */
208 #define	CNT_INTVL	60		/* servers in CNT_INTVL sec. */
209 #define	RETRYTIME	(60*10)		/* retry after bind or server fail */
210 
211 #define	SIGBLOCK	(sigmask(SIGCHLD)|sigmask(SIGHUP)|sigmask(SIGALRM))
212 
213 int	debug;
214 #ifdef LIBWRAP
215 int	lflag;
216 #endif
217 int	nsock, maxsock;
218 fd_set	allsock;
219 int	options;
220 int	timingout;
221 struct	servent *sp;
222 char	*curdom;
223 
224 #ifndef OPEN_MAX
225 #define OPEN_MAX	64
226 #endif
227 
228 /* Reserve some descriptors, 3 stdio + at least: 1 log, 1 conf. file */
229 #define FD_MARGIN	(8)
230 typeof(((struct rlimit *)0)->rlim_cur)	rlim_ofile_cur = OPEN_MAX;
231 
232 #ifdef RLIMIT_NOFILE
233 struct rlimit	rlim_ofile;
234 #endif
235 
236 struct	servtab {
237 	char	*se_hostaddr;		/* host address to listen on */
238 	char	*se_service;		/* name of service */
239 	int	se_socktype;		/* type of socket to use */
240 	int	se_family;		/* address family */
241 	char	*se_proto;		/* protocol used */
242 	int	se_rpcprog;		/* rpc program number */
243 	int	se_rpcversl;		/* rpc program lowest version */
244 	int	se_rpcversh;		/* rpc program highest version */
245 #define isrpcservice(sep)	((sep)->se_rpcversl != 0)
246 	short	se_wait;		/* single threaded server */
247 	short	se_checked;		/* looked at during merge */
248 	char	*se_user;		/* user name to run as */
249 	char	*se_group;		/* group name to run as */
250 	struct	biltin *se_bi;		/* if built-in, description */
251 	char	*se_server;		/* server program */
252 #define	MAXARGV 20
253 	char	*se_argv[MAXARGV+1];	/* program arguments */
254 	int	se_fd;			/* open descriptor */
255 	int	se_type;		/* type */
256 	union {
257 		struct	sockaddr se_un_ctrladdr;
258 		struct	sockaddr_in se_un_ctrladdr_in;
259 		struct	sockaddr_un se_un_ctrladdr_un;
260 	} se_un;			/* bound address */
261 #define se_ctrladdr	se_un.se_un_ctrladdr
262 #define se_ctrladdr_in	se_un.se_un_ctrladdr_in
263 #define se_ctrladdr_un	se_un.se_un_ctrladdr_un
264 	int	se_ctrladdr_size;
265 	int	se_max;			/* max # of instances of this service */
266 	int	se_count;		/* number started since se_time */
267 	struct	timeval se_time;	/* start of se_count */
268 #ifdef MULOG
269 	int	se_log;
270 #define MULOG_RFC931	0x40000000
271 #endif
272 	struct	servtab *se_next;
273 } *servtab;
274 
275 #define NORM_TYPE	0
276 #define MUX_TYPE	1
277 #define MUXPLUS_TYPE	2
278 #define ISMUX(sep)	(((sep)->se_type == MUX_TYPE) || \
279 			 ((sep)->se_type == MUXPLUS_TYPE))
280 #define ISMUXPLUS(sep)	((sep)->se_type == MUXPLUS_TYPE)
281 
282 
283 void		chargen_dg __P((int, struct servtab *));
284 void		chargen_stream __P((int, struct servtab *));
285 void		close_sep __P((struct servtab *));
286 void		config __P((int));
287 void		daytime_dg __P((int, struct servtab *));
288 void		daytime_stream __P((int, struct servtab *));
289 void		discard_dg __P((int, struct servtab *));
290 void		discard_stream __P((int, struct servtab *));
291 void		echo_dg __P((int, struct servtab *));
292 void		echo_stream __P((int, struct servtab *));
293 void		endconfig __P((void));
294 struct servtab *enter __P((struct servtab *));
295 void		freeconfig __P((struct servtab *));
296 struct servtab *getconfigent __P((void));
297 void		goaway __P((int));
298 void		machtime_dg __P((int, struct servtab *));
299 void		machtime_stream __P((int, struct servtab *));
300 char	       *newstr __P((char *));
301 char	       *nextline __P((FILE *));
302 void		print_service __P((char *, struct servtab *));
303 void		reapchild __P((int));
304 void		retry __P((int));
305 void		run_service __P((int, struct servtab *));
306 int		setconfig __P((void));
307 void		setup __P((struct servtab *));
308 char	       *sskip __P((char **));
309 char	       *skip __P((char **));
310 void		tcpmux __P((int, struct servtab *));
311 void		usage __P((void));
312 void		logpid __P((void));
313 void		register_rpc __P((struct servtab *sep));
314 void		unregister_rpc __P((struct servtab *sep));
315 void		bump_nofile __P((void));
316 void		inetd_setproctitle __P((char *, int));
317 void		initring __P((void));
318 long		machtime __P((void));
319 static int	getline __P((int, char *, int));
320 int		main __P((int, char *[], char *[]));
321 
322 struct biltin {
323 	char	*bi_service;		/* internally provided service name */
324 	int	bi_socktype;		/* type of socket supported */
325 	short	bi_fork;		/* 1 if should fork before call */
326 	short	bi_wait;		/* 1 if should wait for child */
327 	void	(*bi_fn) __P((int, struct servtab *));
328 					/* function which performs it */
329 } biltins[] = {
330 	/* Echo received data */
331 	{ "echo",	SOCK_STREAM,	1, 0,	echo_stream },
332 	{ "echo",	SOCK_DGRAM,	0, 0,	echo_dg },
333 
334 	/* Internet /dev/null */
335 	{ "discard",	SOCK_STREAM,	1, 0,	discard_stream },
336 	{ "discard",	SOCK_DGRAM,	0, 0,	discard_dg },
337 
338 	/* Return 32 bit time since 1970 */
339 	{ "time",	SOCK_STREAM,	0, 0,	machtime_stream },
340 	{ "time",	SOCK_DGRAM,	0, 0,	machtime_dg },
341 
342 	/* Return human-readable time */
343 	{ "daytime",	SOCK_STREAM,	0, 0,	daytime_stream },
344 	{ "daytime",	SOCK_DGRAM,	0, 0,	daytime_dg },
345 
346 	/* Familiar character generator */
347 	{ "chargen",	SOCK_STREAM,	1, 0,	chargen_stream },
348 	{ "chargen",	SOCK_DGRAM,	0, 0,	chargen_dg },
349 
350 	{ "tcpmux",	SOCK_STREAM,	1, 0,	tcpmux },
351 
352 	{ NULL }
353 };
354 
355 #define NUMINT	(sizeof(intab) / sizeof(struct inent))
356 char	*CONFIG = _PATH_INETDCONF;
357 char	**Argv;
358 char 	*LastArg;
359 extern char	*__progname;
360 
361 #ifdef sun
362 /*
363  * Sun's RPC library caches the result of `dtablesize()'
364  * This is incompatible with our "bumping" of file descriptors "on demand"
365  */
366 int
367 _rpc_dtablesize()
368 {
369 	return rlim_ofile_cur;
370 }
371 #endif
372 
373 int
374 main(argc, argv, envp)
375 	int argc;
376 	char *argv[], *envp[];
377 {
378 	struct servtab *sep, *nsep;
379 	struct sigvec sv;
380 	int ch, dofork;
381 	pid_t pid;
382 
383 	Argv = argv;
384 	if (envp == 0 || *envp == 0)
385 		envp = argv;
386 	while (*envp)
387 		envp++;
388 	LastArg = envp[-1] + strlen(envp[-1]);
389 
390 	while ((ch = getopt(argc, argv,
391 #ifdef LIBWRAP
392 					"dl"
393 #else
394 					"d"
395 #endif
396 					   )) != -1)
397 		switch(ch) {
398 		case 'd':
399 			debug = 1;
400 			options |= SO_DEBUG;
401 			break;
402 #ifdef LIBWRAP
403 		case 'l':
404 			lflag = 1;
405 			break;
406 #endif
407 		case '?':
408 		default:
409 			usage();
410 		}
411 	argc -= optind;
412 	argv += optind;
413 
414 	if (argc > 0)
415 		CONFIG = argv[0];
416 
417 	if (debug == 0)
418 		daemon(0, 0);
419 	openlog(__progname, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
420 	logpid();
421 
422 #ifdef RLIMIT_NOFILE
423 	if (getrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0) {
424 		syslog(LOG_ERR, "getrlimit: %m");
425 	} else {
426 		rlim_ofile_cur = rlim_ofile.rlim_cur;
427 		if (rlim_ofile_cur == RLIM_INFINITY)	/* ! */
428 			rlim_ofile_cur = OPEN_MAX;
429 	}
430 #endif
431 
432 	memset(&sv, 0, sizeof(sv));
433 	sv.sv_mask = SIGBLOCK;
434 	sv.sv_handler = retry;
435 	sigvec(SIGALRM, &sv, (struct sigvec *)0);
436 	config(SIGHUP);
437 	sv.sv_handler = config;
438 	sigvec(SIGHUP, &sv, (struct sigvec *)0);
439 	sv.sv_handler = reapchild;
440 	sigvec(SIGCHLD, &sv, (struct sigvec *)0);
441 	sv.sv_handler = goaway;
442 	sigvec(SIGTERM, &sv, (struct sigvec *)0);
443 	sv.sv_handler = goaway;
444 	sigvec(SIGINT, &sv, (struct sigvec *)0);
445 
446 	{
447 		/* space for daemons to overwrite environment for ps */
448 #define	DUMMYSIZE	100
449 		char dummy[DUMMYSIZE];
450 
451 		(void)memset(dummy, 'x', DUMMYSIZE - 1);
452 		dummy[DUMMYSIZE - 1] = '\0';
453 
454 		(void)setenv("inetd_dummy", dummy, 1);
455 	}
456 
457 	for (;;) {
458 	    int n, ctrl;
459 	    fd_set readable;
460 
461 	    if (nsock == 0) {
462 		(void) sigblock(SIGBLOCK);
463 		while (nsock == 0)
464 		    sigpause(0L);
465 		(void) sigsetmask(0L);
466 	    }
467 	    readable = allsock;
468 	    if ((n = select(maxsock + 1, &readable, (fd_set *)0,
469 		(fd_set *)0, (struct timeval *)0)) <= 0) {
470 		    if (n == -1 && errno != EINTR) {
471 			syslog(LOG_WARNING, "select: %m");
472 			sleep(1);
473 		    }
474 		    continue;
475 	    }
476 	    for (sep = servtab; n && sep; sep = nsep) {
477 	    nsep = sep->se_next;
478 	    if (sep->se_fd != -1 && FD_ISSET(sep->se_fd, &readable)) {
479 		n--;
480 		if (debug)
481 			fprintf(stderr, "someone wants %s\n", sep->se_service);
482 		if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) {
483 			/* XXX here do the libwrap check-before-accept */
484 			ctrl = accept(sep->se_fd, (struct sockaddr *)0,
485 			    (int *)0);
486 			if (debug)
487 				fprintf(stderr, "accept, ctrl %d\n", ctrl);
488 			if (ctrl < 0) {
489 				if (errno != EINTR)
490 					syslog(LOG_WARNING,
491 					    "accept (for %s): %m",
492 					    sep->se_service);
493 				continue;
494 			}
495 		} else
496 			ctrl = sep->se_fd;
497 		(void) sigblock(SIGBLOCK);
498 		pid = 0;
499 #ifdef LIBWRAP_INTERNAL
500 		dofork = 1;
501 #else
502 		dofork = (sep->se_bi == 0 || sep->se_bi->bi_fork);
503 #endif
504 		if (dofork) {
505 			if (sep->se_count++ == 0)
506 			    (void)gettimeofday(&sep->se_time,
507 			        (struct timezone *)0);
508 			else if (sep->se_count >= sep->se_max) {
509 				struct timeval now;
510 
511 				(void)gettimeofday(&now, (struct timezone *)0);
512 				if (now.tv_sec - sep->se_time.tv_sec >
513 				    CNT_INTVL) {
514 					sep->se_time = now;
515 					sep->se_count = 1;
516 				} else {
517 					syslog(LOG_ERR,
518 			"%s/%s server failing (looping), service terminated\n",
519 					    sep->se_service, sep->se_proto);
520 					close_sep(sep);
521 					sigsetmask(0L);
522 					if (!timingout) {
523 						timingout = 1;
524 						alarm(RETRYTIME);
525 					}
526 					continue;
527 				}
528 			}
529 			pid = fork();
530 			if (pid < 0) {
531 				syslog(LOG_ERR, "fork: %m");
532 				if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
533 					close(ctrl);
534 				sigsetmask(0L);
535 				sleep(1);
536 				continue;
537 			}
538 			if (pid != 0 && sep->se_wait) {
539 				sep->se_wait = pid;
540 				FD_CLR(sep->se_fd, &allsock);
541 				nsock--;
542 			}
543 			if (pid == 0 && debug)
544 				setsid();
545 		}
546 		sigsetmask(0L);
547 		if (pid == 0) {
548 			run_service(ctrl, sep);
549 			if (dofork)
550 				exit(0);
551 		}
552 		if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
553 			close(ctrl);
554 	    }
555 	    }
556 	}
557 }
558 
559 void
560 run_service(ctrl, sep)
561 	int ctrl;
562 	struct servtab *sep;
563 {
564 	struct passwd *pwd;
565 	struct group *grp = NULL;	/* XXX gcc */
566 #ifdef LIBWRAP
567 	struct request_info req;
568 	int denied;
569 	char buf[7], *service = NULL;	/* XXX gcc */
570 #endif
571 
572 #ifdef LIBWRAP
573 #ifndef LIBWRAP_INTERNAL
574 	if (sep->se_bi == 0)
575 #endif
576 	if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) {
577 		request_init(&req, RQ_DAEMON, sep->se_argv[0] ?
578 		    sep->se_argv[0] : sep->se_service, RQ_FILE, ctrl, NULL);
579 		fromhost(&req);
580 		denied = !hosts_access(&req);
581 		if (denied || lflag) {
582 			sp = getservbyport(sep->se_ctrladdr_in.sin_port,
583 			    sep->se_proto);
584 			if (sp == NULL) {
585 				(void)snprintf(buf, sizeof buf, "%d",
586 				    ntohs(sep->se_ctrladdr_in.sin_port));
587 				service = buf;
588 			} else
589 				service = sp->s_name;
590 		}
591 		if (denied) {
592 			syslog(deny_severity,
593 			    "refused connection from %.500s, service %s (%s)",
594 			    eval_client(&req), service, sep->se_proto);
595 			goto reject;
596 		}
597 		if (lflag) {
598 			syslog(allow_severity,
599 			    "connection from %.500s, service %s (%s)",
600 			    eval_client(&req), service, sep->se_proto);
601 		}
602 	}
603 #endif /* LIBWRAP */
604 
605 	if (sep->se_bi) {
606 		(*sep->se_bi->bi_fn)(ctrl, sep);
607 	} else {
608 		if ((pwd = getpwnam(sep->se_user)) == NULL) {
609 			syslog(LOG_ERR, "%s/%s: %s: No such user",
610 			    sep->se_service, sep->se_proto, sep->se_user);
611 			goto reject;
612 		}
613 		if (sep->se_group &&
614 		    (grp = getgrnam(sep->se_group)) == NULL) {
615 			syslog(LOG_ERR, "%s/%s: %s: No such group",
616 			    sep->se_service, sep->se_proto, sep->se_group);
617 			goto reject;
618 		}
619 		if (pwd->pw_uid) {
620 			if (sep->se_group)
621 				pwd->pw_gid = grp->gr_gid;
622 			if (setgid(pwd->pw_gid) < 0) {
623 				syslog(LOG_ERR,
624 				 "%s/%s: can't set gid %d: %m", sep->se_service,
625 				    sep->se_proto, pwd->pw_gid);
626 				goto reject;
627 			}
628 			(void) initgroups(pwd->pw_name,
629 			    pwd->pw_gid);
630 			if (setuid(pwd->pw_uid) < 0) {
631 				syslog(LOG_ERR,
632 				 "%s/%s: can't set uid %d: %m", sep->se_service,
633 				    sep->se_proto, pwd->pw_uid);
634 				goto reject;
635 			}
636 		} else if (sep->se_group) {
637 			(void) setgid((gid_t)grp->gr_gid);
638 		}
639 		if (debug)
640 			fprintf(stderr, "%d execl %s\n",
641 			    getpid(), sep->se_server);
642 #ifdef MULOG
643 		if (sep->se_log)
644 			dolog(sep, ctrl);
645 #endif
646 		/* Set our control descriptor to not close-on-exec... */
647 		if (fcntl(ctrl, F_SETFD, 0) < 0)
648 			syslog(LOG_ERR, "fcntl (F_SETFD, 0): %m");
649 		/* ...and dup it to stdin, stdout, and stderr. */
650 		if (ctrl != 0) {
651 			dup2(ctrl, 0);
652 			close(ctrl);
653 			ctrl = 0;
654 		}
655 		dup2(0, 1);
656 		dup2(0, 2);
657 #ifdef RLIMIT_NOFILE
658 		if (rlim_ofile.rlim_cur != rlim_ofile_cur &&
659 		    setrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0)
660 			syslog(LOG_ERR, "setrlimit: %m");
661 #endif
662 		execv(sep->se_server, sep->se_argv);
663 		syslog(LOG_ERR, "cannot execute %s: %m", sep->se_server);
664 	reject:
665 		if (sep->se_socktype != SOCK_STREAM)
666 			recv(ctrl, buf, sizeof (buf), 0);
667 		_exit(1);
668 	}
669 }
670 
671 void
672 reapchild(signo)
673 	int signo;
674 {
675 	int status;
676 	pid_t pid;
677 	struct servtab *sep;
678 
679 	for (;;) {
680 		pid = wait3(&status, WNOHANG, (struct rusage *)0);
681 		if (pid <= 0)
682 			break;
683 		if (debug)
684 			fprintf(stderr, "%d reaped, status %#x\n",
685 			    pid, status);
686 		for (sep = servtab; sep; sep = sep->se_next)
687 			if (sep->se_wait == pid) {
688 				if (WIFEXITED(status) && WEXITSTATUS(status))
689 					syslog(LOG_WARNING,
690 					    "%s: exit status 0x%x",
691 					    sep->se_server, WEXITSTATUS(status));
692 				else if (WIFSIGNALED(status))
693 					syslog(LOG_WARNING,
694 					    "%s: exit signal 0x%x",
695 					    sep->se_server, WTERMSIG(status));
696 				sep->se_wait = 1;
697 				FD_SET(sep->se_fd, &allsock);
698 				nsock++;
699 				if (debug)
700 					fprintf(stderr, "restored %s, fd %d\n",
701 					    sep->se_service, sep->se_fd);
702 			}
703 	}
704 }
705 
706 void
707 config(signo)
708 	int signo;
709 {
710 	struct servtab *sep, *cp, **sepp;
711 	long omask;
712 	int n;
713 
714 	if (!setconfig()) {
715 		syslog(LOG_ERR, "%s: %m", CONFIG);
716 		return;
717 	}
718 	for (sep = servtab; sep; sep = sep->se_next)
719 		sep->se_checked = 0;
720 	while ((cp = getconfigent())) {
721 		for (sep = servtab; sep; sep = sep->se_next)
722 			if (strcmp(sep->se_service, cp->se_service) == 0 &&
723 			    strcmp(sep->se_hostaddr, cp->se_hostaddr) == 0 &&
724 			    strcmp(sep->se_proto, cp->se_proto) == 0 &&
725 			    ISMUX(sep) == ISMUX(cp))
726 				break;
727 		if (sep != 0) {
728 			int i;
729 
730 #define SWAP(type, a, b) {type c=(type)a; (type)a=(type)b; (type)b=(type)c;}
731 
732 			omask = sigblock(SIGBLOCK);
733 			/*
734 			 * sep->se_wait may be holding the pid of a daemon
735 			 * that we're waiting for.  If so, don't overwrite
736 			 * it unless the config file explicitly says don't
737 			 * wait.
738 			 */
739 			if (cp->se_bi == 0 &&
740 			    (sep->se_wait == 1 || cp->se_wait == 0))
741 				sep->se_wait = cp->se_wait;
742 			SWAP(char *, sep->se_user, cp->se_user);
743 			SWAP(char *, sep->se_group, cp->se_group);
744 			SWAP(char *, sep->se_server, cp->se_server);
745 			for (i = 0; i < MAXARGV; i++)
746 				SWAP(char *, sep->se_argv[i], cp->se_argv[i]);
747 			SWAP(int, cp->se_type, sep->se_type);
748 			SWAP(int, cp->se_max, sep->se_max);
749 #undef SWAP
750 			if (isrpcservice(sep))
751 				unregister_rpc(sep);
752 			sep->se_rpcversl = cp->se_rpcversl;
753 			sep->se_rpcversh = cp->se_rpcversh;
754 			sigsetmask(omask);
755 			freeconfig(cp);
756 			if (debug)
757 				print_service("REDO", sep);
758 		} else {
759 			sep = enter(cp);
760 			if (debug)
761 				print_service("ADD ", sep);
762 		}
763 		sep->se_checked = 1;
764 
765 		switch (sep->se_family) {
766 		case AF_UNIX:
767 			if (sep->se_fd != -1)
768 				break;
769 			n = strlen(sep->se_service);
770 			if (n > sizeof(sep->se_ctrladdr_un.sun_path)) {
771 				syslog(LOG_ERR, "%s: address too long",
772 				    sep->se_service);
773 				sep->se_checked = 0;
774 				continue;
775 			}
776 			(void)unlink(sep->se_service);
777 			strncpy(sep->se_ctrladdr_un.sun_path,
778 			    sep->se_service, n);
779 			sep->se_ctrladdr_un.sun_family = AF_UNIX;
780 			sep->se_ctrladdr_size = n +
781 			    sizeof(sep->se_ctrladdr_un) -
782 			    sizeof(sep->se_ctrladdr_un.sun_path);
783 			if (!ISMUX(sep))
784 				setup(sep);
785 			break;
786 		case AF_INET:
787 			sep->se_ctrladdr_in.sin_family = AF_INET;
788 			if (!strcmp(sep->se_hostaddr,"*"))
789 				sep->se_ctrladdr_in.sin_addr.s_addr =
790 				    INADDR_ANY;
791 			else if (!inet_aton(sep->se_hostaddr,
792 			    &sep->se_ctrladdr_in.sin_addr)) {
793 				/* Do we really want to support hostname lookups here? */
794 				struct hostent *hp;
795 				hp = gethostbyname(sep->se_hostaddr);
796 				if (hp == 0) {
797 					syslog(LOG_ERR, "%s: unknown host",
798 					    sep->se_hostaddr);
799 					sep->se_checked = 0;
800 					continue;
801 				} else if (hp->h_addrtype != AF_INET) {
802 					syslog(LOG_ERR,
803 				       "%s: address isn't an Internet address",
804 					    sep->se_hostaddr);
805 					sep->se_checked = 0;
806 					continue;
807 				} else if (hp->h_length != sizeof(struct in_addr)) {
808 					syslog(LOG_ERR,
809 		       "%s: address size wrong (under DNS corruption attack?)",
810 					    sep->se_hostaddr);
811 					sep->se_checked = 0;
812 					continue;
813 				} else {
814 					memcpy(&sep->se_ctrladdr_in.sin_addr,
815 					    hp->h_addr_list[0],
816 					    sizeof(struct in_addr));
817 				}
818 			}
819 			if (ISMUX(sep)) {
820 				sep->se_fd = -1;
821 				continue;
822 			}
823 			sep->se_ctrladdr_size = sizeof(sep->se_ctrladdr_in);
824 			if (isrpcservice(sep)) {
825 				struct rpcent *rp;
826 
827 				sep->se_rpcprog = atoi(sep->se_service);
828 				if (sep->se_rpcprog == 0) {
829 					rp = getrpcbyname(sep->se_service);
830 					if (rp == 0) {
831 						syslog(LOG_ERR,
832 						    "%s/%s: unknown service",
833 						    sep->se_service,
834 						    sep->se_proto);
835 						sep->se_checked = 0;
836 						continue;
837 					}
838 					sep->se_rpcprog = rp->r_number;
839 				}
840 				if (sep->se_fd == -1 && !ISMUX(sep))
841 					setup(sep);
842 				if (sep->se_fd != -1)
843 					register_rpc(sep);
844 			} else {
845 				u_short port = htons(atoi(sep->se_service));
846 
847 				if (!port) {
848 					sp = getservbyname(sep->se_service,
849 					    sep->se_proto);
850 					if (sp == 0) {
851 						syslog(LOG_ERR,
852 						    "%s/%s: unknown service",
853 						    sep->se_service,
854 						    sep->se_proto);
855 						sep->se_checked = 0;
856 						continue;
857 					}
858 					port = sp->s_port;
859 				}
860 				if (port != sep->se_ctrladdr_in.sin_port) {
861 					sep->se_ctrladdr_in.sin_port = port;
862 					if (sep->se_fd >= 0)
863 						close_sep(sep);
864 				}
865 				if (sep->se_fd == -1 && !ISMUX(sep))
866 					setup(sep);
867 			}
868 		}
869 	}
870 	endconfig();
871 	/*
872 	 * Purge anything not looked at above.
873 	 */
874 	omask = sigblock(SIGBLOCK);
875 	sepp = &servtab;
876 	while ((sep = *sepp)) {
877 		if (sep->se_checked) {
878 			sepp = &sep->se_next;
879 			continue;
880 		}
881 		*sepp = sep->se_next;
882 		if (sep->se_fd >= 0)
883 			close_sep(sep);
884 		if (isrpcservice(sep))
885 			unregister_rpc(sep);
886 		if (sep->se_family == AF_UNIX)
887 			(void)unlink(sep->se_service);
888 		if (debug)
889 			print_service("FREE", sep);
890 		freeconfig(sep);
891 		free((char *)sep);
892 	}
893 	(void) sigsetmask(omask);
894 }
895 
896 void
897 retry(signo)
898 	int signo;
899 {
900 	struct servtab *sep;
901 
902 	timingout = 0;
903 	for (sep = servtab; sep; sep = sep->se_next) {
904 		if (sep->se_fd == -1 && !ISMUX(sep)) {
905 			switch (sep->se_family) {
906 			case AF_UNIX:
907 			case AF_INET:
908 				setup(sep);
909 				if (sep->se_fd != -1 && isrpcservice(sep))
910 					register_rpc(sep);
911 				break;
912 			}
913 		}
914 	}
915 }
916 
917 void
918 goaway(signo)
919 	int signo;
920 {
921 	struct servtab *sep;
922 
923 	for (sep = servtab; sep; sep = sep->se_next) {
924 		if (sep->se_fd == -1)
925 			continue;
926 
927 		switch (sep->se_family) {
928 		case AF_UNIX:
929 			(void)unlink(sep->se_service);
930 			break;
931 		case AF_INET:
932 			if (sep->se_wait == 1 && isrpcservice(sep))
933 				unregister_rpc(sep);
934 			break;
935 		}
936 		(void)close(sep->se_fd);
937 	}
938 	(void)unlink(_PATH_INETDPID);
939 	exit(0);
940 }
941 
942 void
943 setup(sep)
944 	struct servtab *sep;
945 {
946 	int on = 1;
947 
948 	if ((sep->se_fd = socket(sep->se_family, sep->se_socktype, 0)) < 0) {
949 		if (debug)
950 			fprintf(stderr, "socket failed on %s/%s: %s\n",
951 			    sep->se_service, sep->se_proto, strerror(errno));
952 		syslog(LOG_ERR, "%s/%s: socket: %m",
953 		    sep->se_service, sep->se_proto);
954 		return;
955 	}
956 	/* Set all listening sockets to close-on-exec. */
957 	if (fcntl(sep->se_fd, F_SETFD, FD_CLOEXEC) < 0)
958 		syslog(LOG_ERR, "fcntl (F_SETFD, FD_CLOEXEC): %m");
959 #define	turnon(fd, opt) \
960 setsockopt(fd, SOL_SOCKET, opt, (char *)&on, sizeof (on))
961 	if (strcmp(sep->se_proto, "tcp") == 0 && (options & SO_DEBUG) &&
962 	    turnon(sep->se_fd, SO_DEBUG) < 0)
963 		syslog(LOG_ERR, "setsockopt (SO_DEBUG): %m");
964 	if (turnon(sep->se_fd, SO_REUSEADDR) < 0)
965 		syslog(LOG_ERR, "setsockopt (SO_REUSEADDR): %m");
966 #undef turnon
967 	if (bind(sep->se_fd, &sep->se_ctrladdr, sep->se_ctrladdr_size) < 0) {
968 		if (debug)
969 			fprintf(stderr, "bind failed on %s/%s: %s\n",
970 			    sep->se_service, sep->se_proto, strerror(errno));
971 		syslog(LOG_ERR, "%s/%s: bind: %m",
972 		    sep->se_service, sep->se_proto);
973 		(void) close(sep->se_fd);
974 		sep->se_fd = -1;
975 		if (!timingout) {
976 			timingout = 1;
977 			alarm(RETRYTIME);
978 		}
979 		return;
980 	}
981 	if (sep->se_socktype == SOCK_STREAM)
982 		listen(sep->se_fd, 10);
983 
984 	FD_SET(sep->se_fd, &allsock);
985 	nsock++;
986 	if (sep->se_fd > maxsock) {
987 		maxsock = sep->se_fd;
988 		if (maxsock > rlim_ofile_cur - FD_MARGIN)
989 			bump_nofile();
990 	}
991 	if (debug)
992 		fprintf(stderr, "registered %s on %d\n",
993 		    sep->se_server, sep->se_fd);
994 }
995 
996 /*
997  * Finish with a service and its socket.
998  */
999 void
1000 close_sep(sep)
1001 	struct servtab *sep;
1002 {
1003 	if (sep->se_fd >= 0) {
1004 		nsock--;
1005 		FD_CLR(sep->se_fd, &allsock);
1006 		(void) close(sep->se_fd);
1007 		sep->se_fd = -1;
1008 	}
1009 	sep->se_count = 0;
1010 	/*
1011 	 * Don't keep the pid of this running deamon: when reapchild()
1012 	 * reaps this pid, it would erroneously increment nsock.
1013 	 */
1014 	if (sep->se_wait > 1)
1015 		sep->se_wait = 1;
1016 }
1017 
1018 void
1019 register_rpc(sep)
1020 	struct servtab *sep;
1021 {
1022 #ifdef RPC
1023 	int n;
1024 	struct sockaddr_in sin;
1025 	struct protoent *pp;
1026 
1027 	if ((pp = getprotobyname(sep->se_proto+4)) == NULL) {
1028 		syslog(LOG_ERR, "%s: getproto: %m",
1029 		    sep->se_proto);
1030 		return;
1031 	}
1032 	n = sizeof sin;
1033 	if (getsockname(sep->se_fd, (struct sockaddr *)&sin, &n) < 0) {
1034 		syslog(LOG_ERR, "%s/%s: getsockname: %m",
1035 		    sep->se_service, sep->se_proto);
1036 		return;
1037 	}
1038 
1039 	for (n = sep->se_rpcversl; n <= sep->se_rpcversh; n++) {
1040 		if (debug)
1041 			fprintf(stderr, "pmap_set: %u %u %u %u\n",
1042 			    sep->se_rpcprog, n, pp->p_proto,
1043 			    ntohs(sin.sin_port));
1044 		(void)pmap_unset(sep->se_rpcprog, n);
1045 		if (!pmap_set(sep->se_rpcprog, n, pp->p_proto, ntohs(sin.sin_port)))
1046 			syslog(LOG_ERR, "pmap_set: %u %u %u %u: %m",
1047 			    sep->se_rpcprog, n, pp->p_proto,
1048 			    ntohs(sin.sin_port));
1049 	}
1050 #endif /* RPC */
1051 }
1052 
1053 void
1054 unregister_rpc(sep)
1055 	struct servtab *sep;
1056 {
1057 #ifdef RPC
1058 	int n;
1059 
1060 	for (n = sep->se_rpcversl; n <= sep->se_rpcversh; n++) {
1061 		if (debug)
1062 			fprintf(stderr, "pmap_unset(%u, %u)\n",
1063 			    sep->se_rpcprog, n);
1064 		if (!pmap_unset(sep->se_rpcprog, n))
1065 			syslog(LOG_ERR, "pmap_unset(%u, %u)\n",
1066 			    sep->se_rpcprog, n);
1067 	}
1068 #endif /* RPC */
1069 }
1070 
1071 
1072 struct servtab *
1073 enter(cp)
1074 	struct servtab *cp;
1075 {
1076 	struct servtab *sep;
1077 	long omask;
1078 
1079 	sep = (struct servtab *)malloc(sizeof (*sep));
1080 	if (sep == (struct servtab *)0) {
1081 		syslog(LOG_ERR, "Out of memory.");
1082 		exit(-1);
1083 	}
1084 	*sep = *cp;
1085 	sep->se_fd = -1;
1086 	sep->se_rpcprog = -1;
1087 	omask = sigblock(SIGBLOCK);
1088 	sep->se_next = servtab;
1089 	servtab = sep;
1090 	sigsetmask(omask);
1091 	return (sep);
1092 }
1093 
1094 FILE	*fconfig = NULL;
1095 struct	servtab serv;
1096 char	line[LINE_MAX];
1097 char    *defhost;
1098 
1099 int
1100 setconfig()
1101 {
1102 	if (defhost) free(defhost);
1103 	defhost = newstr("*");
1104 	if (fconfig != NULL) {
1105 		fseek(fconfig, 0L, SEEK_SET);
1106 		return (1);
1107 	}
1108 	fconfig = fopen(CONFIG, "r");
1109 	return (fconfig != NULL);
1110 }
1111 
1112 void
1113 endconfig()
1114 {
1115 	if (fconfig) {
1116 		(void) fclose(fconfig);
1117 		fconfig = NULL;
1118 	}
1119 	if (defhost) {
1120 		free(defhost);
1121 		defhost = 0;
1122 	}
1123 }
1124 
1125 struct servtab *
1126 getconfigent()
1127 {
1128 	struct servtab *sep = &serv;
1129 	int argc;
1130 	char *cp, *arg;
1131 	static char TCPMUX_TOKEN[] = "tcpmux/";
1132 #define MUX_LEN		(sizeof(TCPMUX_TOKEN)-1)
1133 	char *hostdelim;
1134 
1135 more:
1136 #ifdef MULOG
1137 	while ((cp = nextline(fconfig)) && (*cp == '#' || *cp == '\0')) {
1138 		/* Avoid use of `skip' if there is a danger of it looking
1139 		 * at continuation lines.
1140 		 */
1141 		do {
1142 			cp++;
1143 		} while (*cp == ' ' || *cp == '\t');
1144 		if (*cp == '\0')
1145 			continue;
1146 		if ((arg = skip(&cp)) == NULL)
1147 			continue;
1148 		if (strcmp(arg, "DOMAIN"))
1149 			continue;
1150 		if (curdom)
1151 			free(curdom);
1152 		curdom = NULL;
1153 		while (*cp == ' ' || *cp == '\t')
1154 			cp++;
1155 		if (*cp == '\0')
1156 			continue;
1157 		arg = cp;
1158 		while (*cp && *cp != ' ' && *cp != '\t')
1159 			cp++;
1160 		if (*cp != '\0')
1161 			*cp++ = '\0';
1162 		curdom = newstr(arg);
1163 	}
1164 #else
1165 	while ((cp = nextline(fconfig)) && (*cp == '#' || *cp == '\0'))
1166 		;
1167 #endif
1168 	if (cp == NULL)
1169 		return ((struct servtab *)0);
1170 	/*
1171 	 * clear the static buffer, since some fields (se_ctrladdr,
1172 	 * for example) don't get initialized here.
1173 	 */
1174 	memset((caddr_t)sep, 0, sizeof *sep);
1175 	arg = skip(&cp);
1176 	if (cp == NULL) {
1177 		/* got an empty line containing just blanks/tabs. */
1178 		goto more;
1179 	}
1180 	/* Check for a host name. */
1181 	hostdelim = strrchr(arg, ':');
1182 	if (hostdelim) {
1183 		*hostdelim = '\0';
1184 		sep->se_hostaddr = newstr(arg);
1185 		arg = hostdelim + 1;
1186 		/*
1187 		 * If the line is of the form `host:', then just change the
1188 		 * default host for the following lines.
1189 		 */
1190 		if (*arg == '\0') {
1191 			arg = skip(&cp);
1192 			if (cp == NULL) {
1193 				free(defhost);
1194 				defhost = sep->se_hostaddr;
1195 				goto more;
1196 			}
1197 		}
1198 	} else
1199 		sep->se_hostaddr = newstr(defhost);
1200 	if (strncmp(arg, TCPMUX_TOKEN, MUX_LEN) == 0) {
1201 		char *c = arg + MUX_LEN;
1202 		if (*c == '+') {
1203 			sep->se_type = MUXPLUS_TYPE;
1204 			c++;
1205 		} else
1206 			sep->se_type = MUX_TYPE;
1207 		sep->se_service = newstr(c);
1208 	} else {
1209 		sep->se_service = newstr(arg);
1210 		sep->se_type = NORM_TYPE;
1211 	}
1212 
1213 	arg = sskip(&cp);
1214 	if (strcmp(arg, "stream") == 0)
1215 		sep->se_socktype = SOCK_STREAM;
1216 	else if (strcmp(arg, "dgram") == 0)
1217 		sep->se_socktype = SOCK_DGRAM;
1218 	else if (strcmp(arg, "rdm") == 0)
1219 		sep->se_socktype = SOCK_RDM;
1220 	else if (strcmp(arg, "seqpacket") == 0)
1221 		sep->se_socktype = SOCK_SEQPACKET;
1222 	else if (strcmp(arg, "raw") == 0)
1223 		sep->se_socktype = SOCK_RAW;
1224 	else
1225 		sep->se_socktype = -1;
1226 
1227 	sep->se_proto = newstr(sskip(&cp));
1228 	if (strcmp(sep->se_proto, "unix") == 0) {
1229 		sep->se_family = AF_UNIX;
1230 	} else {
1231 		sep->se_family = AF_INET;
1232 		if (strncmp(sep->se_proto, "rpc/", 4) == 0) {
1233 #ifdef RPC
1234 			char *cp, *ccp;
1235 			cp = strchr(sep->se_service, '/');
1236 			if (cp == 0) {
1237 				syslog(LOG_ERR, "%s: no rpc version",
1238 				    sep->se_service);
1239 				goto more;
1240 			}
1241 			*cp++ = '\0';
1242 			sep->se_rpcversl = sep->se_rpcversh =
1243 			    strtol(cp, &ccp, 0);
1244 			if (ccp == cp) {
1245 		badafterall:
1246 				syslog(LOG_ERR, "%s/%s: bad rpc version",
1247 				    sep->se_service, cp);
1248 				goto more;
1249 			}
1250 			if (*ccp == '-') {
1251 				cp = ccp + 1;
1252 				sep->se_rpcversh = strtol(cp, &ccp, 0);
1253 				if (ccp == cp)
1254 					goto badafterall;
1255 			}
1256 #else
1257 			syslog(LOG_ERR, "%s: rpc services not suported",
1258 			    sep->se_service);
1259 			goto more;
1260 #endif /* RPC */
1261 		}
1262 	}
1263 	arg = sskip(&cp);
1264 	{
1265 		char *cp;
1266 		cp = strchr(arg, '.');
1267 		if (cp) {
1268 			*cp++ = '\0';
1269 			sep->se_max = atoi(cp);
1270 		} else
1271 			sep->se_max = TOOMANY;
1272 	}
1273 	sep->se_wait = strcmp(arg, "wait") == 0;
1274 	if (ISMUX(sep)) {
1275 		/*
1276 		 * Silently enforce "nowait" for TCPMUX services since
1277 		 * they don't have an assigned port to listen on.
1278 		 */
1279 		sep->se_wait = 0;
1280 
1281 		if (strcmp(sep->se_proto, "tcp")) {
1282 			syslog(LOG_ERR,
1283 			    "%s: bad protocol for tcpmux service %s",
1284 			    CONFIG, sep->se_service);
1285 			goto more;
1286 		}
1287 		if (sep->se_socktype != SOCK_STREAM) {
1288 			syslog(LOG_ERR,
1289 			    "%s: bad socket type for tcpmux service %s",
1290 			    CONFIG, sep->se_service);
1291 			goto more;
1292 		}
1293 	}
1294 	sep->se_user = newstr(sskip(&cp));
1295 	if ((sep->se_group = strchr(sep->se_user, '.')))
1296 		*sep->se_group++ = '\0';
1297 	sep->se_server = newstr(sskip(&cp));
1298 	if (strcmp(sep->se_server, "internal") == 0) {
1299 		struct biltin *bi;
1300 
1301 		for (bi = biltins; bi->bi_service; bi++)
1302 			if (bi->bi_socktype == sep->se_socktype &&
1303 			    strcmp(bi->bi_service, sep->se_service) == 0)
1304 				break;
1305 		if (bi->bi_service == 0) {
1306 			syslog(LOG_ERR, "internal service %s unknown",
1307 			    sep->se_service);
1308 			goto more;
1309 		}
1310 		sep->se_bi = bi;
1311 		sep->se_wait = bi->bi_wait;
1312 	} else
1313 		sep->se_bi = NULL;
1314 	argc = 0;
1315 	for (arg = skip(&cp); cp; arg = skip(&cp)) {
1316 #if MULOG
1317 		char *colon;
1318 
1319 		if (argc == 0 && (colon = strrchr(arg, ':'))) {
1320 			while (arg < colon) {
1321 				int	x;
1322 				char	*ccp;
1323 
1324 				switch (*arg++) {
1325 				case 'l':
1326 					x = 1;
1327 					if (isdigit(*arg)) {
1328 						x = strtol(arg, &ccp, 0);
1329 						if (ccp == arg)
1330 							break;
1331 						arg = ccp;
1332 					}
1333 					sep->se_log &= ~MULOG_RFC931;
1334 					sep->se_log |= x;
1335 					break;
1336 				case 'a':
1337 					sep->se_log |= MULOG_RFC931;
1338 					break;
1339 				default:
1340 					break;
1341 				}
1342 			}
1343 			arg = colon + 1;
1344 		}
1345 #endif
1346 		if (argc < MAXARGV)
1347 			sep->se_argv[argc++] = newstr(arg);
1348 	}
1349 	while (argc <= MAXARGV)
1350 		sep->se_argv[argc++] = NULL;
1351 	return (sep);
1352 }
1353 
1354 void
1355 freeconfig(cp)
1356 	struct servtab *cp;
1357 {
1358 	int i;
1359 
1360 	if (cp->se_hostaddr)
1361 		free(cp->se_hostaddr);
1362 	if (cp->se_service)
1363 		free(cp->se_service);
1364 	if (cp->se_proto)
1365 		free(cp->se_proto);
1366 	if (cp->se_user)
1367 		free(cp->se_user);
1368 	/* Note: se_group is part of the newstr'ed se_user */
1369 	if (cp->se_server)
1370 		free(cp->se_server);
1371 	for (i = 0; i < MAXARGV; i++)
1372 		if (cp->se_argv[i])
1373 			free(cp->se_argv[i]);
1374 }
1375 
1376 
1377 /*
1378  * Safe skip - if skip returns null, log a syntax error in the
1379  * configuration file and exit.
1380  */
1381 char *
1382 sskip(cpp)
1383 	char **cpp;
1384 {
1385 	char *cp;
1386 
1387 	cp = skip(cpp);
1388 	if (cp == NULL) {
1389 		syslog(LOG_ERR, "%s: syntax error", CONFIG);
1390 		exit(-1);
1391 	}
1392 	return (cp);
1393 }
1394 
1395 char *
1396 skip(cpp)
1397 	char **cpp;
1398 {
1399 	char *cp = *cpp;
1400 	char *start;
1401 
1402 	if (*cpp == NULL)
1403 		return ((char *)0);
1404 
1405 again:
1406 	while (*cp == ' ' || *cp == '\t')
1407 		cp++;
1408 	if (*cp == '\0') {
1409 		int c;
1410 
1411 		c = getc(fconfig);
1412 		(void) ungetc(c, fconfig);
1413 		if (c == ' ' || c == '\t')
1414 			if ((cp = nextline(fconfig)))
1415 				goto again;
1416 		*cpp = (char *)0;
1417 		return ((char *)0);
1418 	}
1419 	start = cp;
1420 	while (*cp && *cp != ' ' && *cp != '\t')
1421 		cp++;
1422 	if (*cp != '\0')
1423 		*cp++ = '\0';
1424 	*cpp = cp;
1425 	return (start);
1426 }
1427 
1428 char *
1429 nextline(fd)
1430 	FILE *fd;
1431 {
1432 	char *cp;
1433 
1434 	if (fgets(line, sizeof (line), fd) == NULL)
1435 		return ((char *)0);
1436 	cp = strchr(line, '\n');
1437 	if (cp)
1438 		*cp = '\0';
1439 	return (line);
1440 }
1441 
1442 char *
1443 newstr(cp)
1444 	char *cp;
1445 {
1446 	if ((cp = strdup(cp ? cp : "")))
1447 		return (cp);
1448 	syslog(LOG_ERR, "strdup: %m");
1449 	exit(-1);
1450 }
1451 
1452 void
1453 inetd_setproctitle(a, s)
1454 	char *a;
1455 	int s;
1456 {
1457 	int size;
1458 	char *cp;
1459 	struct sockaddr_in sin;
1460 	char buf[80];
1461 
1462 	cp = Argv[0];
1463 	size = sizeof(sin);
1464 	if (getpeername(s, (struct sockaddr *)&sin, &size) == 0)
1465 		(void)snprintf(buf, sizeof buf, "-%s [%s]", a,
1466 		    inet_ntoa(sin.sin_addr));
1467 	else
1468 		(void)snprintf(buf, sizeof buf, "-%s", a);
1469 	strncpy(cp, buf, LastArg - cp);
1470 	cp += strlen(cp);
1471 	while (cp < LastArg)
1472 		*cp++ = ' ';
1473 }
1474 
1475 void
1476 logpid()
1477 {
1478 	FILE *fp;
1479 
1480 	if ((fp = fopen(_PATH_INETDPID, "w")) != NULL) {
1481 		fprintf(fp, "%u\n", getpid());
1482 		(void)fclose(fp);
1483 	}
1484 }
1485 
1486 void
1487 bump_nofile()
1488 {
1489 #ifdef RLIMIT_NOFILE
1490 
1491 #define FD_CHUNK	32
1492 
1493 	struct rlimit rl;
1494 
1495 	if (getrlimit(RLIMIT_NOFILE, &rl) < 0) {
1496 		syslog(LOG_ERR, "getrlimit: %m");
1497 		return;
1498 	}
1499 	rl.rlim_cur = MIN(rl.rlim_max, rl.rlim_cur + FD_CHUNK);
1500 	if (rl.rlim_cur <= rlim_ofile_cur) {
1501 		syslog(LOG_ERR,
1502 		    "bump_nofile: cannot extend file limit, max = %d",
1503 		    (int)rl.rlim_cur);
1504 		return;
1505 	}
1506 
1507 	if (setrlimit(RLIMIT_NOFILE, &rl) < 0) {
1508 		syslog(LOG_ERR, "setrlimit: %m");
1509 		return;
1510 	}
1511 
1512 	rlim_ofile_cur = rl.rlim_cur;
1513 	return;
1514 
1515 #else
1516 	syslog(LOG_ERR, "bump_nofile: cannot extend file limit");
1517 	return;
1518 #endif
1519 }
1520 
1521 /*
1522  * Internet services provided internally by inetd:
1523  */
1524 #define	BUFSIZE	4096
1525 
1526 /* ARGSUSED */
1527 void
1528 echo_stream(s, sep)		/* Echo service -- echo data back */
1529 	int s;
1530 	struct servtab *sep;
1531 {
1532 	char buffer[BUFSIZE];
1533 	int i;
1534 
1535 	inetd_setproctitle(sep->se_service, s);
1536 	while ((i = read(s, buffer, sizeof(buffer))) > 0 &&
1537 	    write(s, buffer, i) > 0)
1538 		;
1539 }
1540 
1541 /* ARGSUSED */
1542 void
1543 echo_dg(s, sep)			/* Echo service -- echo data back */
1544 	int s;
1545 	struct servtab *sep;
1546 {
1547 	char buffer[BUFSIZE];
1548 	int i, size;
1549 	struct sockaddr sa;
1550 
1551 	size = sizeof(sa);
1552 	if ((i = recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size)) < 0)
1553 		return;
1554 	(void) sendto(s, buffer, i, 0, &sa, sizeof(sa));
1555 }
1556 
1557 /* ARGSUSED */
1558 void
1559 discard_stream(s, sep)		/* Discard service -- ignore data */
1560 	int s;
1561 	struct servtab *sep;
1562 {
1563 	char buffer[BUFSIZE];
1564 
1565 	inetd_setproctitle(sep->se_service, s);
1566 	while ((errno = 0, read(s, buffer, sizeof(buffer)) > 0) ||
1567 			errno == EINTR)
1568 		;
1569 }
1570 
1571 /* ARGSUSED */
1572 void
1573 discard_dg(s, sep)		/* Discard service -- ignore data */
1574 	int s;
1575 	struct servtab *sep;
1576 {
1577 	char buffer[BUFSIZE];
1578 
1579 	(void) read(s, buffer, sizeof(buffer));
1580 }
1581 
1582 #include <ctype.h>
1583 #define LINESIZ 72
1584 char ring[128];
1585 char *endring;
1586 
1587 void
1588 initring()
1589 {
1590 	int i;
1591 
1592 	endring = ring;
1593 
1594 	for (i = 0; i <= 128; ++i)
1595 		if (isprint(i))
1596 			*endring++ = i;
1597 }
1598 
1599 /* ARGSUSED */
1600 void
1601 chargen_stream(s, sep)		/* Character generator */
1602 	int s;
1603 	struct servtab *sep;
1604 {
1605 	int len;
1606 	char *rs, text[LINESIZ+2];
1607 
1608 	inetd_setproctitle(sep->se_service, s);
1609 
1610 	if (!endring) {
1611 		initring();
1612 		rs = ring;
1613 	}
1614 
1615 	text[LINESIZ] = '\r';
1616 	text[LINESIZ + 1] = '\n';
1617 	for (rs = ring;;) {
1618 		if ((len = endring - rs) >= LINESIZ)
1619 			memmove(text, rs, LINESIZ);
1620 		else {
1621 			memmove(text, rs, len);
1622 			memmove(text + len, ring, LINESIZ - len);
1623 		}
1624 		if (++rs == endring)
1625 			rs = ring;
1626 		if (write(s, text, sizeof(text)) != sizeof(text))
1627 			break;
1628 	}
1629 }
1630 
1631 /* ARGSUSED */
1632 void
1633 chargen_dg(s, sep)		/* Character generator */
1634 	int s;
1635 	struct servtab *sep;
1636 {
1637 	struct sockaddr sa;
1638 	static char *rs;
1639 	int len, size;
1640 	char text[LINESIZ+2];
1641 
1642 	if (endring == 0) {
1643 		initring();
1644 		rs = ring;
1645 	}
1646 
1647 	size = sizeof(sa);
1648 	if (recvfrom(s, text, sizeof(text), 0, &sa, &size) < 0)
1649 		return;
1650 
1651 	if ((len = endring - rs) >= LINESIZ)
1652 		memmove(text, rs, LINESIZ);
1653 	else {
1654 		memmove(text, rs, len);
1655 		memmove(text + len, ring, LINESIZ - len);
1656 	}
1657 	if (++rs == endring)
1658 		rs = ring;
1659 	text[LINESIZ] = '\r';
1660 	text[LINESIZ + 1] = '\n';
1661 	(void) sendto(s, text, sizeof(text), 0, &sa, sizeof(sa));
1662 }
1663 
1664 /*
1665  * Return a machine readable date and time, in the form of the
1666  * number of seconds since midnight, Jan 1, 1900.  Since gettimeofday
1667  * returns the number of seconds since midnight, Jan 1, 1970,
1668  * we must add 2208988800 seconds to this figure to make up for
1669  * some seventy years Bell Labs was asleep.
1670  */
1671 
1672 long
1673 machtime()
1674 {
1675 	struct timeval tv;
1676 
1677 	if (gettimeofday(&tv, (struct timezone *)0) < 0) {
1678 		if (debug)
1679 			fprintf(stderr, "Unable to get time of day\n");
1680 		return (0L);
1681 	}
1682 #define	OFFSET ((u_long)25567 * 24*60*60)
1683 	return (htonl((long)(tv.tv_sec + OFFSET)));
1684 #undef OFFSET
1685 }
1686 
1687 /* ARGSUSED */
1688 void
1689 machtime_stream(s, sep)
1690 	int s;
1691 	struct servtab *sep;
1692 {
1693 	long result;
1694 
1695 	result = machtime();
1696 	(void) write(s, (char *) &result, sizeof(result));
1697 }
1698 
1699 /* ARGSUSED */
1700 void
1701 machtime_dg(s, sep)
1702 	int s;
1703 	struct servtab *sep;
1704 {
1705 	long result;
1706 	struct sockaddr sa;
1707 	int size;
1708 
1709 	size = sizeof(sa);
1710 	if (recvfrom(s, (char *)&result, sizeof(result), 0, &sa, &size) < 0)
1711 		return;
1712 	result = machtime();
1713 	(void) sendto(s, (char *) &result, sizeof(result), 0, &sa, sizeof(sa));
1714 }
1715 
1716 /* ARGSUSED */
1717 void
1718 daytime_stream(s, sep)		/* Return human-readable time of day */
1719 	int s;
1720 	struct servtab *sep;
1721 {
1722 	char buffer[256];
1723 	time_t clock;
1724 	int len;
1725 
1726 	clock = time((time_t *) 0);
1727 
1728 	len = snprintf(buffer, sizeof buffer, "%.24s\r\n", ctime(&clock));
1729 	(void) write(s, buffer, len);
1730 }
1731 
1732 /* ARGSUSED */
1733 void
1734 daytime_dg(s, sep)		/* Return human-readable time of day */
1735 	int s;
1736 	struct servtab *sep;
1737 {
1738 	char buffer[256];
1739 	time_t clock;
1740 	struct sockaddr sa;
1741 	int size, len;
1742 
1743 	clock = time((time_t *) 0);
1744 
1745 	size = sizeof(sa);
1746 	if (recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size) < 0)
1747 		return;
1748 	len = snprintf(buffer, sizeof buffer, "%.24s\r\n", ctime(&clock));
1749 	(void) sendto(s, buffer, len, 0, &sa, sizeof(sa));
1750 }
1751 
1752 /*
1753  * print_service:
1754  *	Dump relevant information to stderr
1755  */
1756 void
1757 print_service(action, sep)
1758 	char *action;
1759 	struct servtab *sep;
1760 {
1761 	if (isrpcservice(sep))
1762 		fprintf(stderr,
1763 		    "%s: %s rpcprog=%d, rpcvers = %d/%d, proto=%s, wait.max=%d.%d, user.group=%s.%s builtin=%lx server=%s\n",
1764 		    action, sep->se_service,
1765 		    sep->se_rpcprog, sep->se_rpcversh, sep->se_rpcversl, sep->se_proto,
1766 		    sep->se_wait, sep->se_max, sep->se_user, sep->se_group,
1767 		    (long)sep->se_bi, sep->se_server);
1768 	else
1769 		fprintf(stderr,
1770 		    "%s: %s proto=%s, wait.max=%d.%d, user.group=%s.%s builtin=%lx server=%s\n",
1771 		    action, sep->se_service, sep->se_proto,
1772 		    sep->se_wait, sep->se_max, sep->se_user, sep->se_group,
1773 		    (long)sep->se_bi, sep->se_server);
1774 }
1775 
1776 void
1777 usage()
1778 {
1779 
1780 #ifdef LIBWRAP
1781 	(void)fprintf(stderr, "usage: %s [-dl] [conf]\n", __progname);
1782 #else
1783 	(void)fprintf(stderr, "usage: %s [-d] [conf]\n", __progname);
1784 #endif
1785 	exit(1);
1786 }
1787 
1788 
1789 /*
1790  *  Based on TCPMUX.C by Mark K. Lottor November 1988
1791  *  sri-nic::ps:<mkl>tcpmux.c
1792  */
1793 
1794 static int		/* # of characters upto \r,\n or \0 */
1795 getline(fd, buf, len)
1796 	int fd;
1797 	char *buf;
1798 	int len;
1799 {
1800 	int count = 0, n;
1801 
1802 	do {
1803 		n = read(fd, buf, len-count);
1804 		if (n == 0)
1805 			return (count);
1806 		if (n < 0)
1807 			return (-1);
1808 		while (--n >= 0) {
1809 			if (*buf == '\r' || *buf == '\n' || *buf == '\0')
1810 				return (count);
1811 			count++;
1812 			buf++;
1813 		}
1814 	} while (count < len);
1815 	return (count);
1816 }
1817 
1818 #define MAX_SERV_LEN	(256+2)		/* 2 bytes for \r\n */
1819 
1820 #define strwrite(fd, buf)	(void) write(fd, buf, sizeof(buf)-1)
1821 
1822 void
1823 tcpmux(ctrl, sep)
1824 	int ctrl;
1825 	struct servtab *sep;
1826 {
1827 	char service[MAX_SERV_LEN+1];
1828 	int len;
1829 
1830 	/* Get requested service name */
1831 	if ((len = getline(ctrl, service, MAX_SERV_LEN)) < 0) {
1832 		strwrite(ctrl, "-Error reading service name\r\n");
1833 		goto reject;
1834 	}
1835 	service[len] = '\0';
1836 
1837 	if (debug)
1838 		fprintf(stderr, "tcpmux: someone wants %s\n", service);
1839 
1840 	/*
1841 	 * Help is a required command, and lists available services,
1842 	 * one per line.
1843 	 */
1844 	if (!strcasecmp(service, "help")) {
1845 		strwrite(ctrl, "+Available services:\r\n");
1846 		strwrite(ctrl, "help\r\n");
1847 		for (sep = servtab; sep; sep = sep->se_next) {
1848 			if (!ISMUX(sep))
1849 				continue;
1850 			(void)write(ctrl, sep->se_service,
1851 			    strlen(sep->se_service));
1852 			strwrite(ctrl, "\r\n");
1853 		}
1854 		goto reject;
1855 	}
1856 
1857 	/* Try matching a service in inetd.conf with the request */
1858 	for (sep = servtab; sep; sep = sep->se_next) {
1859 		if (!ISMUX(sep))
1860 			continue;
1861 		if (!strcasecmp(service, sep->se_service)) {
1862 			if (ISMUXPLUS(sep))
1863 				strwrite(ctrl, "+Go\r\n");
1864 			run_service(ctrl, sep);
1865 			return;
1866 		}
1867 	}
1868 	strwrite(ctrl, "-Service not available\r\n");
1869 reject:
1870 	_exit(1);
1871 }
1872 
1873 
1874 #ifdef MULOG
1875 dolog(sep, ctrl)
1876 	struct servtab *sep;
1877 	int		ctrl;
1878 {
1879 	struct sockaddr		sa;
1880 	struct sockaddr_in	*sin = (struct sockaddr_in *)&sa;
1881 	int			len = sizeof(sa);
1882 	struct hostent		*hp;
1883 	char			*host, *dp, buf[BUFSIZ], *rfc931_name();
1884 	int			connected = 1;
1885 
1886 	if (sep->se_family != AF_INET)
1887 		return;
1888 
1889 	if (getpeername(ctrl, &sa, &len) < 0) {
1890 		if (errno != ENOTCONN) {
1891 			syslog(LOG_ERR, "getpeername: %m");
1892 			return;
1893 		}
1894 		if (recvfrom(ctrl, buf, sizeof(buf), MSG_PEEK, &sa, &len) < 0) {
1895 			syslog(LOG_ERR, "recvfrom: %m");
1896 			return;
1897 		}
1898 		connected = 0;
1899 	}
1900 	if (sa.sa_family != AF_INET) {
1901 		syslog(LOG_ERR, "unexpected address family %u", sa.sa_family);
1902 		return;
1903 	}
1904 
1905 	hp = gethostbyaddr((char *) &sin->sin_addr.s_addr,
1906 				sizeof (sin->sin_addr.s_addr), AF_INET);
1907 
1908 	host = hp?hp->h_name:inet_ntoa(sin->sin_addr);
1909 
1910 	switch (sep->se_log & ~MULOG_RFC931) {
1911 	case 0:
1912 		return;
1913 	case 1:
1914 		if (curdom == NULL || *curdom == '\0')
1915 			break;
1916 		dp = host + strlen(host) - strlen(curdom);
1917 		if (dp < host)
1918 			break;
1919 		if (debug)
1920 			fprintf(stderr, "check \"%s\" against curdom \"%s\"\n",
1921 			    host, curdom);
1922 		if (strcasecmp(dp, curdom) == 0)
1923 			return;
1924 		break;
1925 	case 2:
1926 	default:
1927 		break;
1928 	}
1929 
1930 	openlog("", LOG_NOWAIT, MULOG);
1931 
1932 	if (connected && (sep->se_log & MULOG_RFC931))
1933 		syslog(LOG_INFO, "%s@%s wants %s",
1934 		    rfc931_name(sin, ctrl), host, sep->se_service);
1935 	else
1936 		syslog(LOG_INFO, "%s wants %s",
1937 		    host, sep->se_service);
1938 }
1939 
1940 /*
1941  * From tcp_log by
1942  *  Wietse Venema, Eindhoven University of Technology, The Netherlands.
1943  */
1944 #if 0
1945 static char sccsid[] = "@(#) rfc931.c 1.3 92/08/31 22:54:46";
1946 #endif
1947 
1948 #include <setjmp.h>
1949 
1950 #define	RFC931_PORT	113		/* Semi-well-known port */
1951 #define	TIMEOUT		4
1952 #define	TIMEOUT2	10
1953 
1954 static jmp_buf timebuf;
1955 
1956 /* timeout - handle timeouts */
1957 
1958 static void timeout(sig)
1959 int     sig;
1960 {
1961 	longjmp(timebuf, sig);
1962 }
1963 
1964 /* rfc931_name - return remote user name */
1965 
1966 char *
1967 rfc931_name(there, ctrl)
1968 struct sockaddr_in *there;		/* remote link information */
1969 int	ctrl;
1970 {
1971 	struct sockaddr_in here;	/* local link information */
1972 	struct sockaddr_in sin;		/* for talking to RFC931 daemon */
1973 	int		length;
1974 	int		s;
1975 	unsigned	remote;
1976 	unsigned	local;
1977 	static char	user[256];		/* XXX */
1978 	char		buf[256];
1979 	char		*cp;
1980 	char		*result = "USER_UNKNOWN";
1981 	int		len;
1982 
1983 	/* Find out local port number of our stdin. */
1984 
1985 	length = sizeof(here);
1986 	if (getsockname(ctrl, (struct sockaddr *) &here, &length) == -1) {
1987 		syslog(LOG_ERR, "getsockname: %m");
1988 		return (result);
1989 	}
1990 	/* Set up timer so we won't get stuck. */
1991 
1992 	if ((s = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
1993 		syslog(LOG_ERR, "socket: %m");
1994 		return (result);
1995 	}
1996 
1997 	sin = here;
1998 	sin.sin_port = htons(0);
1999 	if (bind(s, (struct sockaddr *) &sin, sizeof(sin)) == -1) {
2000 		syslog(LOG_ERR, "bind: %m");
2001 		return (result);
2002 	}
2003 
2004 	signal(SIGALRM, timeout);
2005 	if (setjmp(timebuf)) {
2006 		close(s);			/* not: fclose(fp) */
2007 		return (result);
2008 	}
2009 	alarm(TIMEOUT);
2010 
2011 	/* Connect to the RFC931 daemon. */
2012 
2013 	sin = *there;
2014 	sin.sin_port = htons(RFC931_PORT);
2015 	if (connect(s, (struct sockaddr *) &sin, sizeof(sin)) == -1) {
2016 		close(s);
2017 		alarm(0);
2018 		return (result);
2019 	}
2020 
2021 	/* Query the RFC 931 server. Would 13-byte writes ever be broken up? */
2022 	(void)snprintf(buf, sizeof buf, "%u,%u\r\n", ntohs(there->sin_port),
2023 	    ntohs(here.sin_port));
2024 
2025 
2026 	for (len = 0, cp = buf; len < strlen(buf); ) {
2027 		int	n;
2028 
2029 		if ((n = write(s, cp, strlen(buf) - len)) == -1) {
2030 			close(s);
2031 			alarm(0);
2032 			return (result);
2033 		}
2034 		cp += n;
2035 		len += n;
2036 	}
2037 
2038 	/* Read response */
2039 	for (cp = buf; cp < buf + sizeof(buf) - 1; ) {
2040 		char	c;
2041 		if (read(s, &c, 1) != 1) {
2042 			close(s);
2043 			alarm(0);
2044 			return (result);
2045 		}
2046 		if (c == '\n')
2047 			break;
2048 		*cp++ = c;
2049 	}
2050 	*cp = '\0';
2051 
2052 	if (sscanf(buf, "%u , %u : USERID :%*[^:]:%255s", &remote, &local, user) == 3
2053 		&& ntohs(there->sin_port) == remote
2054 		&& ntohs(here.sin_port) == local) {
2055 
2056 		/* Strip trailing carriage return. */
2057 		if (cp = strchr(user, '\r'))
2058 			*cp = 0;
2059 		result = user;
2060 	}
2061 
2062 	alarm(0);
2063 	close(s);
2064 	return (result);
2065 }
2066 #endif
2067