xref: /netbsd-src/usr.sbin/inetd/inetd.c (revision e9d867ef5010fbab8d48045c13025636f5cd7479)
1 /*
2  * Copyright (c) 1983,1991 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 char copyright[] =
36 "@(#) Copyright (c) 1983 Regents of the University of California.\n\
37  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 /*static char sccsid[] = "from: @(#)inetd.c	5.30 (Berkeley) 6/3/91";*/
42 static char rcsid[] = "$Id: inetd.c,v 1.3 1993/08/01 17:59:33 mycroft Exp $";
43 #endif /* not lint */
44 
45 /*
46  * Inetd - Internet super-server
47  *
48  * This program invokes all internet services as needed.
49  * connection-oriented services are invoked each time a
50  * connection is made, by creating a process.  This process
51  * is passed the connection as file descriptor 0 and is
52  * expected to do a getpeername to find out the source host
53  * 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
71  *	socket type			stream/dgram/raw/rdm/seqpacket
72  *	protocol			must be in /etc/protocols
73  *	wait/nowait			single-threaded/multi-threaded
74  *	user				user to run daemon as
75  *	server program			full path name
76  *	server program arguments	maximum of MAXARGS (20)
77  *
78  * For RPC services
79  *      service name/version            must be in /etc/rpc
80  *	socket type			stream/dgram/raw/rdm/seqpacket
81  *	protocol			must be in /etc/protocols
82  *	wait/nowait			single-threaded/multi-threaded
83  *	user				user to run daemon as
84  *	server program			full path name
85  *	server program arguments	maximum of MAXARGS (20)
86  *
87  * Comment lines are indicated by a `#' in column 1.
88  */
89 #include <sys/param.h>
90 #include <sys/stat.h>
91 #include <sys/ioctl.h>
92 #include <sys/socket.h>
93 #include <sys/file.h>
94 #include <sys/wait.h>
95 #include <sys/time.h>
96 #include <sys/resource.h>
97 
98 #include <netinet/in.h>
99 #include <arpa/inet.h>
100 
101 #include <errno.h>
102 #include <signal.h>
103 #include <netdb.h>
104 #include <syslog.h>
105 #include <pwd.h>
106 #include <stdio.h>
107 #include <string.h>
108 #include <rpc/rpc.h>
109 #include "pathnames.h"
110 
111 #define	TOOMANY		40		/* don't start more than TOOMANY */
112 #define	CNT_INTVL	60		/* servers in CNT_INTVL sec. */
113 #define	RETRYTIME	(60*10)		/* retry after bind or server fail */
114 
115 #define	SIGBLOCK	(sigmask(SIGCHLD)|sigmask(SIGHUP)|sigmask(SIGALRM))
116 
117 void	config(), reapchild(), retry(), unregisterrpc();
118 
119 int	debug = 0;
120 int	nsock, maxsock;
121 fd_set	allsock;
122 int	options;
123 int	timingout;
124 struct	servent *sp;
125 struct	rpcent *rpc;
126 
127 struct	servtab {
128 	char	*se_service;		/* name of service */
129 	int	se_socktype;		/* type of socket to use */
130 	char	*se_proto;		/* protocol used */
131 	short	se_wait;		/* single threaded server */
132 	short	se_checked;		/* looked at during merge */
133 	char	*se_user;		/* user name to run as */
134 	struct	biltin *se_bi;		/* if built-in, description */
135 	char	*se_server;		/* server program */
136 #define	MAXARGV 20
137 	char	*se_argv[MAXARGV+1];	/* program arguments */
138 	int	se_fd;			/* open descriptor */
139 	struct	sockaddr_in se_ctrladdr;/* bound address */
140 	int	se_rpc;			/* ==1 if this is an RPC service */
141         int	se_rpc_prog;		/* RPC program number */
142         u_int	se_rpc_lowvers;		/* RPC low version */
143         u_int	se_rpc_highvers;	/* RPC high version */
144 	int	se_count;		/* number started since se_time */
145 	struct	timeval se_time;	/* start of se_count */
146 	struct	servtab *se_next;
147 } *servtab;
148 
149 int echo_stream(), discard_stream(), machtime_stream();
150 int daytime_stream(), chargen_stream();
151 int echo_dg(), discard_dg(), machtime_dg(), daytime_dg(), chargen_dg();
152 
153 struct biltin {
154 	char	*bi_service;		/* internally provided service name */
155 	int	bi_socktype;		/* type of socket supported */
156 	short	bi_fork;		/* 1 if should fork before call */
157 	short	bi_wait;		/* 1 if should wait for child */
158 	int	(*bi_fn)();		/* function which performs it */
159 } biltins[] = {
160 	/* Echo received data */
161 	"echo",		SOCK_STREAM,	1, 0,	echo_stream,
162 	"echo",		SOCK_DGRAM,	0, 0,	echo_dg,
163 
164 	/* Internet /dev/null */
165 	"discard",	SOCK_STREAM,	1, 0,	discard_stream,
166 	"discard",	SOCK_DGRAM,	0, 0,	discard_dg,
167 
168 	/* Return 32 bit time since 1970 */
169 	"time",		SOCK_STREAM,	0, 0,	machtime_stream,
170 	"time",		SOCK_DGRAM,	0, 0,	machtime_dg,
171 
172 	/* Return human-readable time */
173 	"daytime",	SOCK_STREAM,	0, 0,	daytime_stream,
174 	"daytime",	SOCK_DGRAM,	0, 0,	daytime_dg,
175 
176 	/* Familiar character generator */
177 	"chargen",	SOCK_STREAM,	1, 0,	chargen_stream,
178 	"chargen",	SOCK_DGRAM,	0, 0,	chargen_dg,
179 	0
180 };
181 
182 #define NUMINT	(sizeof(intab) / sizeof(struct inent))
183 char	*CONFIG = _PATH_INETDCONF;
184 char	**Argv;
185 char 	*LastArg;
186 
187 main(argc, argv, envp)
188 	int argc;
189 	char *argv[], *envp[];
190 {
191 	extern char *optarg;
192 	extern int optind;
193 	register struct servtab *sep;
194 	register struct passwd *pwd;
195 	register int tmpint;
196 	struct sigvec sv;
197 	int ch, pid, dofork;
198 	char buf[50];
199 
200 	Argv = argv;
201 	if (envp == 0 || *envp == 0)
202 		envp = argv;
203 	while (*envp)
204 		envp++;
205 	LastArg = envp[-1] + strlen(envp[-1]);
206 
207 	while ((ch = getopt(argc, argv, "d")) != EOF)
208 		switch(ch) {
209 		case 'd':
210 			debug = 1;
211 			options |= SO_DEBUG;
212 			break;
213 		case '?':
214 		default:
215 			fprintf(stderr, "usage: inetd [-d]");
216 			exit(1);
217 		}
218 	argc -= optind;
219 	argv += optind;
220 
221 	if (argc > 0)
222 		CONFIG = argv[0];
223 	if (debug == 0)
224 		daemon(0, 0);
225 	openlog("inetd", LOG_PID | LOG_NOWAIT, LOG_DAEMON);
226 	bzero((char *)&sv, sizeof(sv));
227 	sv.sv_mask = SIGBLOCK;
228 	sv.sv_handler = retry;
229 	sigvec(SIGALRM, &sv, (struct sigvec *)0);
230 	config();
231 	sv.sv_handler = config;
232 	sigvec(SIGHUP, &sv, (struct sigvec *)0);
233 	sv.sv_handler = reapchild;
234 	sigvec(SIGCHLD, &sv, (struct sigvec *)0);
235 
236 	{
237 		/* space for daemons to overwrite environment for ps */
238 #define	DUMMYSIZE	100
239 		char dummy[DUMMYSIZE];
240 
241 		(void)memset(dummy, 'x', sizeof(DUMMYSIZE) - 1);
242 		dummy[DUMMYSIZE - 1] = '\0';
243 		(void)setenv("inetd_dummy", dummy, 1);
244 	}
245 
246 	for (;;) {
247 	    int n, ctrl;
248 	    fd_set readable;
249 
250 	    if (nsock == 0) {
251 		(void) sigblock(SIGBLOCK);
252 		while (nsock == 0)
253 		    sigpause(0L);
254 		(void) sigsetmask(0L);
255 	    }
256 	    readable = allsock;
257 	    if ((n = select(maxsock + 1, &readable, (fd_set *)0,
258 		(fd_set *)0, (struct timeval *)0)) <= 0) {
259 		    if (n < 0 && errno != EINTR)
260 			syslog(LOG_WARNING, "select: %m\n");
261 		    sleep(1);
262 		    continue;
263 	    }
264 	    for (sep = servtab; n && sep; sep = sep->se_next)
265 	        if (sep->se_fd != -1 && FD_ISSET(sep->se_fd, &readable)) {
266 		    n--;
267 		    if (debug)
268 			    fprintf(stderr, "someone wants %s\n",
269 				sep->se_service);
270 		    if (sep->se_socktype == SOCK_STREAM) {
271 			    ctrl = accept(sep->se_fd, (struct sockaddr *)0,
272 				(int *)0);
273 			    if (debug)
274 				    fprintf(stderr, "accept, ctrl %d\n", ctrl);
275 			    if (ctrl < 0) {
276 				    if (errno == EINTR)
277 					    continue;
278 				    syslog(LOG_WARNING, "accept (for %s): %m",
279 					    sep->se_service);
280 				    continue;
281 			    }
282 		    } else
283 			    ctrl = sep->se_fd;
284 		    (void) sigblock(SIGBLOCK);
285 		    pid = 0;
286 		    dofork = (sep->se_bi == 0 || sep->se_bi->bi_fork);
287 		    if (dofork) {
288 			    if (sep->se_count++ == 0)
289 				(void)gettimeofday(&sep->se_time,
290 				    (struct timezone *)0);
291 			    else if (sep->se_count >= TOOMANY) {
292 				struct timeval now;
293 
294 				(void)gettimeofday(&now, (struct timezone *)0);
295 				if (now.tv_sec - sep->se_time.tv_sec >
296 				    CNT_INTVL) {
297 					sep->se_time = now;
298 					sep->se_count = 1;
299 				} else {
300 					syslog(LOG_ERR,
301 			"%s/%s server failing (looping), service terminated\n",
302 					    sep->se_service, sep->se_proto);
303 					FD_CLR(sep->se_fd, &allsock);
304 					(void) close(sep->se_fd);
305 					sep->se_fd = -1;
306 					sep->se_count = 0;
307 					nsock--;
308 					if (!timingout) {
309 						timingout = 1;
310 						alarm(RETRYTIME);
311 					}
312 				}
313 			    }
314 			    pid = fork();
315 		    }
316 		    if (pid < 0) {
317 			    syslog(LOG_ERR, "fork: %m");
318 			    if (sep->se_socktype == SOCK_STREAM)
319 				    close(ctrl);
320 			    sigsetmask(0L);
321 			    sleep(1);
322 			    continue;
323 		    }
324 		    if (pid && sep->se_wait) {
325 			    sep->se_wait = pid;
326 			    if (sep->se_fd >= 0) {
327 				FD_CLR(sep->se_fd, &allsock);
328 			        nsock--;
329 			    }
330 		    }
331 		    sigsetmask(0L);
332 		    if (pid == 0) {
333 			    if (debug && dofork)
334 				setsid();
335 			    if (dofork)
336 				for (tmpint = maxsock; --tmpint > 2; )
337 					if (tmpint != ctrl)
338 						close(tmpint);
339 			    if (sep->se_bi)
340 				(*sep->se_bi->bi_fn)(ctrl, sep);
341 			    else {
342 				if (debug)
343 					fprintf(stderr, "%d execl %s\n",
344 					    getpid(), sep->se_server);
345 				dup2(ctrl, 0);
346 				close(ctrl);
347 				dup2(0, 1);
348 				dup2(0, 2);
349 				if ((pwd = getpwnam(sep->se_user)) == NULL) {
350 					syslog(LOG_ERR,
351 					    "getpwnam: %s: No such user",
352 					    sep->se_user);
353 					if (sep->se_socktype != SOCK_STREAM)
354 						recv(0, buf, sizeof (buf), 0);
355 					_exit(1);
356 				}
357 				if (pwd->pw_uid) {
358 					(void) setgid((gid_t)pwd->pw_gid);
359 					initgroups(pwd->pw_name, pwd->pw_gid);
360 					(void) setuid((uid_t)pwd->pw_uid);
361 				}
362 				execv(sep->se_server, sep->se_argv);
363 				if (sep->se_socktype != SOCK_STREAM)
364 					recv(0, buf, sizeof (buf), 0);
365 				syslog(LOG_ERR, "execv %s: %m", sep->se_server);
366 				_exit(1);
367 			    }
368 		    }
369 		    if (sep->se_socktype == SOCK_STREAM)
370 			    close(ctrl);
371 		}
372 	}
373 }
374 
375 void
376 reapchild()
377 {
378 	int status;
379 	int pid;
380 	register struct servtab *sep;
381 
382 	for (;;) {
383 		pid = wait3(&status, WNOHANG, (struct rusage *)0);
384 		if (pid <= 0)
385 			break;
386 		if (debug)
387 			fprintf(stderr, "%d reaped\n", pid);
388 		for (sep = servtab; sep; sep = sep->se_next)
389 			if (sep->se_wait == pid) {
390 				if (status)
391 					syslog(LOG_WARNING,
392 					    "%s: exit status 0x%x",
393 					    sep->se_server, status);
394 				if (debug)
395 					fprintf(stderr, "restored %s, fd %d\n",
396 					    sep->se_service, sep->se_fd);
397 				FD_SET(sep->se_fd, &allsock);
398 				nsock++;
399 				sep->se_wait = 1;
400 			}
401 	}
402 }
403 
404 void
405 config()
406 {
407 	register struct servtab *sep, *cp, **sepp;
408 	struct servtab *getconfigent(), *enter();
409 	long omask;
410 
411 	if (!setconfig()) {
412 		syslog(LOG_ERR, "%s: %m", CONFIG);
413 		return;
414 	}
415 	for (sep = servtab; sep; sep = sep->se_next)
416 		sep->se_checked = 0;
417 	while (cp = getconfigent()) {
418 		for (sep = servtab; sep; sep = sep->se_next)
419 			if (strcmp(sep->se_service, cp->se_service) == 0 &&
420 			    strcmp(sep->se_proto, cp->se_proto) == 0)
421 				break;
422 		if (sep != 0) {
423 			int i;
424 
425 			omask = sigblock(SIGBLOCK);
426 			/*
427 			 * sep->se_wait may be holding the pid of a daemon
428 			 * that we're waiting for.  If so, don't overwrite
429 			 * it unless the config file explicitly says don't
430 			 * wait.
431 			 */
432 			if (cp->se_bi == 0 &&
433 			    (sep->se_wait == 1 || cp->se_wait == 0))
434 				sep->se_wait = cp->se_wait;
435 #define SWAP(a, b) { char *c = a; a = b; b = c; }
436 			if (cp->se_user)
437 				SWAP(sep->se_user, cp->se_user);
438 			if (cp->se_server)
439 				SWAP(sep->se_server, cp->se_server);
440 			for (i = 0; i < MAXARGV; i++)
441 				SWAP(sep->se_argv[i], cp->se_argv[i]);
442 			sigsetmask(omask);
443 			freeconfig(cp);
444 			if (debug)
445 				print_service("REDO", sep);
446 		} else {
447 			sep = enter(cp);
448 			if (debug)
449 				print_service("ADD ", sep);
450 		}
451 		sep->se_checked = 1;
452                 if (!sep->se_rpc) {
453                         sp = getservbyname(sep->se_service, sep->se_proto);
454                         if (sp == 0) {
455                                 syslog(LOG_ERR, "%s/%s: unknown service",
456                                        sep->se_service, sep->se_proto);
457                                 if (sep->se_fd != -1)
458                                         (void) close(sep->se_fd);
459                                 sep->se_fd = -1;
460                                 continue;
461                         }
462                         if (sp->s_port != sep->se_ctrladdr.sin_port) {
463                                 sep->se_ctrladdr.sin_port = sp->s_port;
464                                 if (sep->se_fd != -1)
465                                         (void) close(sep->se_fd);
466                                 sep->se_fd = -1;
467                         }
468 		}
469                 else {
470                         rpc = getrpcbyname(sep->se_service);
471                         if (rpc == 0) {
472                                 syslog(LOG_ERR, "%s/%s unknown RPC service.",
473                                        sep->se_service, sep->se_proto);
474                                 if (sep->se_fd != -1)
475                                         (void) close(sep->se_fd);
476                                 sep->se_fd = -1;
477                                 continue;
478                         }
479                         if (rpc->r_number != sep->se_rpc_prog) {
480                                 if (sep->se_rpc_prog)
481                                         unregisterrpc(sep);
482                                 sep->se_rpc_prog = rpc->r_number;
483                                 if (sep->se_fd != -1)
484                                         (void) close(sep->se_fd);
485                                 sep->se_fd = -1;
486                         }
487                 }
488 
489 		if (sep->se_fd == -1)
490 			setup(sep);
491 	}
492 	endconfig();
493 	/*
494 	 * Purge anything not looked at above.
495 	 */
496 	omask = sigblock(SIGBLOCK);
497 	sepp = &servtab;
498 	while (sep = *sepp) {
499 		if (sep->se_checked) {
500 			sepp = &sep->se_next;
501 			continue;
502 		}
503 		*sepp = sep->se_next;
504 		if (sep->se_fd != -1) {
505 			FD_CLR(sep->se_fd, &allsock);
506 			nsock--;
507 			(void) close(sep->se_fd);
508 		}
509 		if (debug)
510 			print_service("FREE", sep);
511                 if (sep->se_rpc && sep->se_rpc_prog > 0)
512                         unregisterrpc(sep);
513 		freeconfig(sep);
514 		free((char *)sep);
515 	}
516 	(void) sigsetmask(omask);
517 }
518 
519 void
520 unregisterrpc(sep)
521 	register struct servtab *sep;
522 {
523         int i;
524         struct servtab *sepp;
525 	long omask;
526 
527 	omask = sigblock(SIGBLOCK);
528         for (sepp = servtab; sepp; sepp = sepp->se_next) {
529                 if (sepp == sep)
530                         continue;
531 		if (sep->se_checked == 0 ||
532                     !sepp->se_rpc ||
533                     sep->se_rpc_prog != sepp->se_rpc_prog)
534 			continue;
535                 return;
536         }
537         if (debug)
538                 print_service("UNREG", sep);
539         for (i = sep->se_rpc_lowvers; i <= sep->se_rpc_highvers; i++)
540                 pmap_unset(sep->se_rpc_prog, i);
541         if (sep->se_fd != -1)
542                 (void) close(sep->se_fd);
543         sep->se_fd = -1;
544 	(void) sigsetmask(omask);
545 }
546 
547 void
548 retry()
549 {
550 	register struct servtab *sep;
551 
552 	timingout = 0;
553 	for (sep = servtab; sep; sep = sep->se_next)
554 		if (sep->se_fd == -1)
555 			setup(sep);
556 }
557 
558 setup(sep)
559 	register struct servtab *sep;
560 {
561 	int on = 1;
562 
563 	if ((sep->se_fd = socket(AF_INET, sep->se_socktype, 0)) < 0) {
564 		syslog(LOG_ERR, "%s/%s: socket: %m",
565 		    sep->se_service, sep->se_proto);
566 		return;
567 	}
568 #define	turnon(fd, opt) \
569 setsockopt(fd, SOL_SOCKET, opt, (char *)&on, sizeof (on))
570 	if (strcmp(sep->se_proto, "tcp") == 0 && (options & SO_DEBUG) &&
571 	    turnon(sep->se_fd, SO_DEBUG) < 0)
572 		syslog(LOG_ERR, "setsockopt (SO_DEBUG): %m");
573 	if (turnon(sep->se_fd, SO_REUSEADDR) < 0)
574 		syslog(LOG_ERR, "setsockopt (SO_REUSEADDR): %m");
575 #undef turnon
576 	if (bind(sep->se_fd, (struct sockaddr *)&sep->se_ctrladdr,
577 	    sizeof (sep->se_ctrladdr)) < 0) {
578 		syslog(LOG_ERR, "%s/%s: bind: %m",
579 		    sep->se_service, sep->se_proto);
580 		(void) close(sep->se_fd);
581 		sep->se_fd = -1;
582 		if (!timingout) {
583 			timingout = 1;
584 			alarm(RETRYTIME);
585 		}
586 		return;
587 	}
588         if (sep->se_rpc) {
589                 int i, len;
590                 if (getsockname(sep->se_fd, (struct sockaddr *)&sep->se_ctrladdr,
591                                 &len) < 0) {
592                         syslog(LOG_ERR, "%s/%s: getsockname: %m",
593                                sep->se_service, sep->se_proto);
594                         (void) close(sep->se_fd);
595                         sep->se_fd = -1;
596                         return;
597                 }
598                 if (debug)
599                         print_service("REG ", sep);
600                 for (i = sep->se_rpc_lowvers; i <= sep->se_rpc_highvers; i++) {
601                         pmap_unset(sep->se_rpc_prog, i);
602                         pmap_set(sep->se_rpc_prog, i,
603                                  (sep->se_socktype == SOCK_DGRAM)
604                                  ? IPPROTO_UDP : IPPROTO_TCP,
605                                  ntohs(sep->se_ctrladdr.sin_port));
606                 }
607 
608         }
609 	if (sep->se_socktype == SOCK_STREAM)
610 		listen(sep->se_fd, 10);
611 	FD_SET(sep->se_fd, &allsock);
612 	nsock++;
613 	if (sep->se_fd > maxsock)
614 		maxsock = sep->se_fd;
615 }
616 
617 struct servtab *
618 enter(cp)
619 	struct servtab *cp;
620 {
621 	register struct servtab *sep;
622 	long omask;
623 
624 	sep = (struct servtab *)malloc(sizeof (*sep));
625 	if (sep == (struct servtab *)0) {
626 		syslog(LOG_ERR, "Out of memory.");
627 		exit(-1);
628 	}
629 	*sep = *cp;
630 	sep->se_fd = -1;
631 	omask = sigblock(SIGBLOCK);
632 	sep->se_next = servtab;
633 	servtab = sep;
634 	sigsetmask(omask);
635 	return (sep);
636 }
637 
638 FILE	*fconfig = NULL;
639 struct	servtab serv;
640 char	line[256];
641 char	*skip(), *nextline();
642 
643 setconfig()
644 {
645 
646 	if (fconfig != NULL) {
647 		fseek(fconfig, 0L, L_SET);
648 		return (1);
649 	}
650 	fconfig = fopen(CONFIG, "r");
651 	return (fconfig != NULL);
652 }
653 
654 endconfig()
655 {
656 	if (fconfig) {
657 		(void) fclose(fconfig);
658 		fconfig = NULL;
659 	}
660 }
661 
662 struct servtab *
663 getconfigent()
664 {
665 	register struct servtab *sep = &serv;
666 	int argc;
667 	char *cp, *arg, *newstr();
668         char *versp;
669 
670 more:
671 	while ((cp = nextline(fconfig)) && *cp == '#')
672 		;
673 	if (cp == NULL)
674 		return ((struct servtab *)0);
675 	sep->se_service = newstr(skip(&cp));
676 	arg = skip(&cp);
677 	if (strcmp(arg, "stream") == 0)
678 		sep->se_socktype = SOCK_STREAM;
679 	else if (strcmp(arg, "dgram") == 0)
680 		sep->se_socktype = SOCK_DGRAM;
681 	else if (strcmp(arg, "rdm") == 0)
682 		sep->se_socktype = SOCK_RDM;
683 	else if (strcmp(arg, "seqpacket") == 0)
684 		sep->se_socktype = SOCK_SEQPACKET;
685 	else if (strcmp(arg, "raw") == 0)
686 		sep->se_socktype = SOCK_RAW;
687 	else
688 		sep->se_socktype = -1;
689 	sep->se_proto = newstr(skip(&cp));
690         sep->se_rpc = 0;
691         if (strncmp(sep->se_proto, "rpc/", 4) == 0) {
692                 sep->se_proto += 4;
693                 sep->se_rpc = 1;
694                 sep->se_rpc_prog = sep->se_rpc_lowvers = sep->se_rpc_lowvers = 0;
695                 sep->se_ctrladdr.sin_family = AF_INET;
696                 sep->se_ctrladdr.sin_port = 0;
697                 sep->se_ctrladdr.sin_addr.s_addr = htonl(INADDR_ANY);
698                 if (versp = rindex(sep->se_service, '/')) {
699                         *versp++ = '\0';
700                         switch (sscanf(versp, "%d-%d",
701                                        &sep->se_rpc_lowvers,
702                                        &sep->se_rpc_highvers)) {
703                         case 2:
704                                 break;
705                         case 1:
706                                 sep->se_rpc_highvers =
707                                         sep->se_rpc_lowvers;
708                                 break;
709                         default:
710                                 syslog(LOG_ERR, "bad RPC version specifier; %s\n", sep->se_service);
711                                 freeconfig(sep);
712                                 goto more;
713                         }
714                 }
715                 else {
716                         sep->se_rpc_lowvers =
717                                 sep->se_rpc_highvers = 1;
718                 }
719         }
720 	arg = skip(&cp);
721 	sep->se_wait = strcmp(arg, "wait") == 0;
722 	sep->se_user = newstr(skip(&cp));
723 	sep->se_server = newstr(skip(&cp));
724 	if (strcmp(sep->se_server, "internal") == 0) {
725 		register struct biltin *bi;
726 
727 		for (bi = biltins; bi->bi_service; bi++)
728 			if (bi->bi_socktype == sep->se_socktype &&
729 			    strcmp(bi->bi_service, sep->se_service) == 0)
730 				break;
731 		if (bi->bi_service == 0) {
732 			syslog(LOG_ERR, "internal service %s unknown\n",
733 				sep->se_service);
734 			goto more;
735 		}
736 		sep->se_bi = bi;
737 		sep->se_wait = bi->bi_wait;
738 	} else
739 		sep->se_bi = NULL;
740 	argc = 0;
741 	for (arg = skip(&cp); cp; arg = skip(&cp))
742 		if (argc < MAXARGV)
743 			sep->se_argv[argc++] = newstr(arg);
744 	while (argc <= MAXARGV)
745 		sep->se_argv[argc++] = NULL;
746 	return (sep);
747 }
748 
749 freeconfig(cp)
750 	register struct servtab *cp;
751 {
752 	int i;
753 
754 	if (cp->se_service)
755 		free(cp->se_service);
756 	if (cp->se_proto)
757 		free(cp->se_proto);
758 	if (cp->se_user)
759 		free(cp->se_user);
760 	if (cp->se_server)
761 		free(cp->se_server);
762 	for (i = 0; i < MAXARGV; i++)
763 		if (cp->se_argv[i])
764 			free(cp->se_argv[i]);
765 }
766 
767 char *
768 skip(cpp)
769 	char **cpp;
770 {
771 	register char *cp = *cpp;
772 	char *start;
773 
774 again:
775 	while (*cp == ' ' || *cp == '\t')
776 		cp++;
777 	if (*cp == '\0') {
778 		int c;
779 
780 		c = getc(fconfig);
781 		(void) ungetc(c, fconfig);
782 		if (c == ' ' || c == '\t')
783 			if (cp = nextline(fconfig))
784 				goto again;
785 		*cpp = (char *)0;
786 		return ((char *)0);
787 	}
788 	start = cp;
789 	while (*cp && *cp != ' ' && *cp != '\t')
790 		cp++;
791 	if (*cp != '\0')
792 		*cp++ = '\0';
793 	*cpp = cp;
794 	return (start);
795 }
796 
797 char *
798 nextline(fd)
799 	FILE *fd;
800 {
801 	char *cp;
802 
803 	if (fgets(line, sizeof (line), fd) == NULL)
804 		return ((char *)0);
805 	cp = index(line, '\n');
806 	if (cp)
807 		*cp = '\0';
808 	return (line);
809 }
810 
811 char *
812 newstr(cp)
813 	char *cp;
814 {
815 	if (cp = strdup(cp ? cp : ""))
816 		return(cp);
817 	syslog(LOG_ERR, "strdup: %m");
818 	exit(-1);
819 }
820 
821 setproctitle(a, s)
822 	char *a;
823 	int s;
824 {
825 	int size;
826 	register char *cp;
827 	struct sockaddr_in sin;
828 	char buf[80];
829 
830 	cp = Argv[0];
831 	size = sizeof(sin);
832 	if (getpeername(s, (struct sockaddr *)&sin, &size) == 0)
833 		(void) sprintf(buf, "-%s [%s]", a, inet_ntoa(sin.sin_addr));
834 	else
835 		(void) sprintf(buf, "-%s", a);
836 	strncpy(cp, buf, LastArg - cp);
837 	cp += strlen(cp);
838 	while (cp < LastArg)
839 		*cp++ = ' ';
840 }
841 
842 /*
843  * Internet services provided internally by inetd:
844  */
845 #define	BUFSIZE	8192
846 
847 /* ARGSUSED */
848 echo_stream(s, sep)		/* Echo service -- echo data back */
849 	int s;
850 	struct servtab *sep;
851 {
852 	char buffer[BUFSIZE];
853 	int i;
854 
855 	setproctitle(sep->se_service, s);
856 	while ((i = read(s, buffer, sizeof(buffer))) > 0 &&
857 	    write(s, buffer, i) > 0)
858 		;
859 	exit(0);
860 }
861 
862 /* ARGSUSED */
863 echo_dg(s, sep)			/* Echo service -- echo data back */
864 	int s;
865 	struct servtab *sep;
866 {
867 	char buffer[BUFSIZE];
868 	int i, size;
869 	struct sockaddr sa;
870 
871 	size = sizeof(sa);
872 	if ((i = recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size)) < 0)
873 		return;
874 	(void) sendto(s, buffer, i, 0, &sa, sizeof(sa));
875 }
876 
877 /* ARGSUSED */
878 discard_stream(s, sep)		/* Discard service -- ignore data */
879 	int s;
880 	struct servtab *sep;
881 {
882 	int ret;
883 	char buffer[BUFSIZE];
884 
885 	setproctitle(sep->se_service, s);
886 	while (1) {
887 		while ((ret = read(s, buffer, sizeof(buffer))) > 0)
888 			;
889 		if (ret == 0 || errno != EINTR)
890 			break;
891 	}
892 	exit(0);
893 }
894 
895 /* ARGSUSED */
896 discard_dg(s, sep)		/* Discard service -- ignore data */
897 	int s;
898 	struct servtab *sep;
899 {
900 	char buffer[BUFSIZE];
901 
902 	(void) read(s, buffer, sizeof(buffer));
903 }
904 
905 #include <ctype.h>
906 #define LINESIZ 72
907 char ring[128];
908 char *endring;
909 
910 initring()
911 {
912 	register int i;
913 
914 	endring = ring;
915 
916 	for (i = 0; i <= 128; ++i)
917 		if (isprint(i))
918 			*endring++ = i;
919 }
920 
921 /* ARGSUSED */
922 chargen_stream(s, sep)		/* Character generator */
923 	int s;
924 	struct servtab *sep;
925 {
926 	register char *rs;
927 	int len;
928 	char text[LINESIZ+2];
929 
930 	setproctitle(sep->se_service, s);
931 
932 	if (!endring) {
933 		initring();
934 		rs = ring;
935 	}
936 
937 	text[LINESIZ] = '\r';
938 	text[LINESIZ + 1] = '\n';
939 	for (rs = ring;;) {
940 		if ((len = endring - rs) >= LINESIZ)
941 			bcopy(rs, text, LINESIZ);
942 		else {
943 			bcopy(rs, text, len);
944 			bcopy(ring, text + len, LINESIZ - len);
945 		}
946 		if (++rs == endring)
947 			rs = ring;
948 		if (write(s, text, sizeof(text)) != sizeof(text))
949 			break;
950 	}
951 	exit(0);
952 }
953 
954 /* ARGSUSED */
955 chargen_dg(s, sep)		/* Character generator */
956 	int s;
957 	struct servtab *sep;
958 {
959 	struct sockaddr sa;
960 	static char *rs;
961 	int len, size;
962 	char text[LINESIZ+2];
963 
964 	if (endring == 0) {
965 		initring();
966 		rs = ring;
967 	}
968 
969 	size = sizeof(sa);
970 	if (recvfrom(s, text, sizeof(text), 0, &sa, &size) < 0)
971 		return;
972 
973 	if ((len = endring - rs) >= LINESIZ)
974 		bcopy(rs, text, LINESIZ);
975 	else {
976 		bcopy(rs, text, len);
977 		bcopy(ring, text + len, LINESIZ - len);
978 	}
979 	if (++rs == endring)
980 		rs = ring;
981 	text[LINESIZ] = '\r';
982 	text[LINESIZ + 1] = '\n';
983 	(void) sendto(s, text, sizeof(text), 0, &sa, sizeof(sa));
984 }
985 
986 /*
987  * Return a machine readable date and time, in the form of the
988  * number of seconds since midnight, Jan 1, 1900.  Since gettimeofday
989  * returns the number of seconds since midnight, Jan 1, 1970,
990  * we must add 2208988800 seconds to this figure to make up for
991  * some seventy years Bell Labs was asleep.
992  */
993 
994 long
995 machtime()
996 {
997 	struct timeval tv;
998 
999 	if (gettimeofday(&tv, (struct timezone *)0) < 0) {
1000 		fprintf(stderr, "Unable to get time of day\n");
1001 		return (0L);
1002 	}
1003 	return (htonl((long)tv.tv_sec + 2208988800));
1004 }
1005 
1006 /* ARGSUSED */
1007 machtime_stream(s, sep)
1008 	int s;
1009 	struct servtab *sep;
1010 {
1011 	long result;
1012 
1013 	result = machtime();
1014 	(void) write(s, (char *) &result, sizeof(result));
1015 }
1016 
1017 /* ARGSUSED */
1018 machtime_dg(s, sep)
1019 	int s;
1020 	struct servtab *sep;
1021 {
1022 	long result;
1023 	struct sockaddr sa;
1024 	int size;
1025 
1026 	size = sizeof(sa);
1027 	if (recvfrom(s, (char *)&result, sizeof(result), 0, &sa, &size) < 0)
1028 		return;
1029 	result = machtime();
1030 	(void) sendto(s, (char *) &result, sizeof(result), 0, &sa, sizeof(sa));
1031 }
1032 
1033 /* ARGSUSED */
1034 daytime_stream(s, sep)		/* Return human-readable time of day */
1035 	int s;
1036 	struct servtab *sep;
1037 {
1038 	char buffer[256];
1039 	time_t time(), clock;
1040 	char *ctime();
1041 
1042 	clock = time((time_t *) 0);
1043 
1044 	(void) sprintf(buffer, "%.24s\r\n", ctime(&clock));
1045 	(void) write(s, buffer, strlen(buffer));
1046 }
1047 
1048 /* ARGSUSED */
1049 daytime_dg(s, sep)		/* Return human-readable time of day */
1050 	int s;
1051 	struct servtab *sep;
1052 {
1053 	char buffer[256];
1054 	time_t time(), clock;
1055 	struct sockaddr sa;
1056 	int size;
1057 	char *ctime();
1058 
1059 	clock = time((time_t *) 0);
1060 
1061 	size = sizeof(sa);
1062 	if (recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size) < 0)
1063 		return;
1064 	(void) sprintf(buffer, "%.24s\r\n", ctime(&clock));
1065 	(void) sendto(s, buffer, strlen(buffer), 0, &sa, sizeof(sa));
1066 }
1067 
1068 /*
1069  * print_service:
1070  *	Dump relevant information to stderr
1071  */
1072 print_service(action, sep)
1073 	char *action;
1074 	struct servtab *sep;
1075 {
1076         if (sep->se_rpc)
1077                 fprintf(stderr,
1078                         "%s: %s rpcnum=%d, rpcvers=%d/%d, wait=%d, user=%s builtin=%x server=%s\n",
1079                         action, sep->se_service,
1080                         sep->se_rpc_prog, sep->se_rpc_lowvers, sep->se_rpc_highvers,
1081                         sep->se_wait, sep->se_user, (int)sep->se_bi, sep->se_server);
1082         else
1083                 fprintf(stderr,
1084                         "%s: %s proto=%s, wait=%d, user=%s builtin=%x server=%s\n",
1085                         action, sep->se_service, sep->se_proto,
1086                         sep->se_wait, sep->se_user, (int)sep->se_bi, sep->se_server);
1087 }
1088