1 /*
2 * Copyright (c) 1983, 1991, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
4 *
5 * %sccs.include.redist.c%
6 */
7
8 #ifndef lint
9 static char copyright[] =
10 "@(#) Copyright (c) 1983, 1991, 1993, 1994\n\
11 The Regents of the University of California. All rights reserved.\n";
12 #endif /* not lint */
13
14 #ifndef lint
15 static char sccsid[] = "@(#)inetd.c 8.4 (Berkeley) 04/13/94";
16 #endif /* not lint */
17
18 /*
19 * Inetd - Internet super-server
20 *
21 * This program invokes all internet services as needed. Connection-oriented
22 * services are invoked each time a connection is made, by creating a process.
23 * This process is passed the connection as file descriptor 0 and is expected
24 * to do a getpeername to find out the source host and port.
25 *
26 * Datagram oriented services are invoked when a datagram
27 * arrives; a process is created and passed a pending message
28 * on file descriptor 0. Datagram servers may either connect
29 * to their peer, freeing up the original socket for inetd
30 * to receive further messages on, or ``take over the socket'',
31 * processing all arriving datagrams and, eventually, timing
32 * out. The first type of server is said to be ``multi-threaded'';
33 * the second type of server ``single-threaded''.
34 *
35 * Inetd uses a configuration file which is read at startup
36 * and, possibly, at some later time in response to a hangup signal.
37 * The configuration file is ``free format'' with fields given in the
38 * order shown below. Continuation lines for an entry must being with
39 * a space or tab. All fields must be present in each entry.
40 *
41 * service name must be in /etc/services or must
42 * name a tcpmux service
43 * socket type stream/dgram/raw/rdm/seqpacket
44 * protocol must be in /etc/protocols
45 * wait/nowait single-threaded/multi-threaded
46 * user user to run daemon as
47 * server program full path name
48 * server program arguments maximum of MAXARGS (20)
49 *
50 * TCP services without official port numbers are handled with the
51 * RFC1078-based tcpmux internal service. Tcpmux listens on port 1 for
52 * requests. When a connection is made from a foreign host, the service
53 * requested is passed to tcpmux, which looks it up in the servtab list
54 * and returns the proper entry for the service. Tcpmux returns a
55 * negative reply if the service doesn't exist, otherwise the invoked
56 * server is expected to return the positive reply if the service type in
57 * inetd.conf file has the prefix "tcpmux/". If the service type has the
58 * prefix "tcpmux/+", tcpmux will return the positive reply for the
59 * process; this is for compatibility with older server code, and also
60 * allows you to invoke programs that use stdin/stdout without putting any
61 * special server code in them. Services that use tcpmux are "nowait"
62 * because they do not have a well-known port and hence cannot listen
63 * for new requests.
64 *
65 * Comment lines are indicated by a `#' in column 1.
66 */
67 #include <sys/param.h>
68 #include <sys/stat.h>
69 #include <sys/ioctl.h>
70 #include <sys/socket.h>
71 #include <sys/wait.h>
72 #include <sys/time.h>
73 #include <sys/resource.h>
74
75 #include <netinet/in.h>
76 #include <arpa/inet.h>
77
78 #include <errno.h>
79 #include <fcntl.h>
80 #include <netdb.h>
81 #include <pwd.h>
82 #include <signal.h>
83 #include <stdio.h>
84 #include <stdlib.h>
85 #include <string.h>
86 #include <syslog.h>
87 #include <unistd.h>
88
89 #include "pathnames.h"
90
91 #define TOOMANY 40 /* don't start more than TOOMANY */
92 #define CNT_INTVL 60 /* servers in CNT_INTVL sec. */
93 #define RETRYTIME (60*10) /* retry after bind or server fail */
94
95 #define SIGBLOCK (sigmask(SIGCHLD)|sigmask(SIGHUP)|sigmask(SIGALRM))
96
97
98 int debug = 0;
99 int nsock, maxsock;
100 fd_set allsock;
101 int options;
102 int timingout;
103 int toomany = TOOMANY;
104 struct servent *sp;
105
106 struct servtab {
107 char *se_service; /* name of service */
108 int se_socktype; /* type of socket to use */
109 char *se_proto; /* protocol used */
110 short se_wait; /* single threaded server */
111 short se_checked; /* looked at during merge */
112 char *se_user; /* user name to run as */
113 struct biltin *se_bi; /* if built-in, description */
114 char *se_server; /* server program */
115 #define MAXARGV 20
116 char *se_argv[MAXARGV+1]; /* program arguments */
117 int se_fd; /* open descriptor */
118 int se_type; /* type */
119 struct sockaddr_in se_ctrladdr;/* bound address */
120 int se_count; /* number started since se_time */
121 struct timeval se_time; /* start of se_count */
122 struct servtab *se_next;
123 } *servtab;
124
125 #define NORM_TYPE 0
126 #define MUX_TYPE 1
127 #define MUXPLUS_TYPE 2
128 #define ISMUX(sep) (((sep)->se_type == MUX_TYPE) || \
129 ((sep)->se_type == MUXPLUS_TYPE))
130 #define ISMUXPLUS(sep) ((sep)->se_type == MUXPLUS_TYPE)
131
132
133 void chargen_dg __P((int, struct servtab *));
134 void chargen_stream __P((int, struct servtab *));
135 void close_sep __P((struct servtab *));
136 void config __P((int));
137 void daytime_dg __P((int, struct servtab *));
138 void daytime_stream __P((int, struct servtab *));
139 void discard_dg __P((int, struct servtab *));
140 void discard_stream __P((int, struct servtab *));
141 void echo_dg __P((int, struct servtab *));
142 void echo_stream __P((int, struct servtab *));
143 void endconfig __P((void));
144 struct servtab *enter __P((struct servtab *));
145 void freeconfig __P((struct servtab *));
146 struct servtab *getconfigent __P((void));
147 void machtime_dg __P((int, struct servtab *));
148 void machtime_stream __P((int, struct servtab *));
149 char *newstr __P((char *));
150 char *nextline __P((FILE *));
151 void print_service __P((char *, struct servtab *));
152 void reapchild __P((int));
153 void retry __P((int));
154 int setconfig __P((void));
155 void setup __P((struct servtab *));
156 char *sskip __P((char **));
157 char *skip __P((char **));
158 struct servtab *tcpmux __P((int));
159
160 struct biltin {
161 char *bi_service; /* internally provided service name */
162 int bi_socktype; /* type of socket supported */
163 short bi_fork; /* 1 if should fork before call */
164 short bi_wait; /* 1 if should wait for child */
165 void (*bi_fn)(); /* function which performs it */
166 } biltins[] = {
167 /* Echo received data */
168 { "echo", SOCK_STREAM, 1, 0, echo_stream },
169 { "echo", SOCK_DGRAM, 0, 0, echo_dg },
170
171 /* Internet /dev/null */
172 { "discard", SOCK_STREAM, 1, 0, discard_stream },
173 { "discard", SOCK_DGRAM, 0, 0, discard_dg },
174
175 /* Return 32 bit time since 1970 */
176 { "time", SOCK_STREAM, 0, 0, machtime_stream },
177 { "time", SOCK_DGRAM, 0, 0, machtime_dg },
178
179 /* Return human-readable time */
180 { "daytime", SOCK_STREAM, 0, 0, daytime_stream },
181 { "daytime", SOCK_DGRAM, 0, 0, daytime_dg },
182
183 /* Familiar character generator */
184 { "chargen", SOCK_STREAM, 1, 0, chargen_stream },
185 { "chargen", SOCK_DGRAM, 0, 0, chargen_dg },
186
187 { "tcpmux", SOCK_STREAM, 1, 0, (void (*)())tcpmux },
188
189 { NULL }
190 };
191
192 #define NUMINT (sizeof(intab) / sizeof(struct inent))
193 char *CONFIG = _PATH_INETDCONF;
194 char **Argv;
195 char *LastArg;
196
197 int
main(argc,argv,envp)198 main(argc, argv, envp)
199 int argc;
200 char *argv[], *envp[];
201 {
202 struct servtab *sep;
203 struct passwd *pwd;
204 struct sigvec sv;
205 int tmpint, ch, dofork;
206 pid_t pid;
207 char buf[50];
208
209 Argv = argv;
210 if (envp == 0 || *envp == 0)
211 envp = argv;
212 while (*envp)
213 envp++;
214 LastArg = envp[-1] + strlen(envp[-1]);
215
216 openlog("inetd", LOG_PID | LOG_NOWAIT, LOG_DAEMON);
217
218 while ((ch = getopt(argc, argv, "dR:")) != EOF)
219 switch(ch) {
220 case 'd':
221 debug = 1;
222 options |= SO_DEBUG;
223 break;
224 case 'R': { /* invocation rate */
225 char *p;
226
227 tmpint = strtol(optarg, &p, 0);
228 if (tmpint < 1 || *p)
229 syslog(LOG_ERR,
230 "-R %s: bad value for service invocation rate",
231 optarg);
232 else
233 toomany = tmpint;
234 break;
235 }
236 case '?':
237 default:
238 syslog(LOG_ERR,
239 "usage: inetd [-d] [-R rate] [conf-file]");
240 exit(1);
241 }
242 argc -= optind;
243 argv += optind;
244
245 if (argc > 0)
246 CONFIG = argv[0];
247 if (debug == 0) {
248 daemon(0, 0);
249 }
250 memset(&sv, 0, sizeof(sv));
251 sv.sv_mask = SIGBLOCK;
252 sv.sv_handler = retry;
253 sigvec(SIGALRM, &sv, (struct sigvec *)0);
254 config(SIGHUP);
255 sv.sv_handler = config;
256 sigvec(SIGHUP, &sv, (struct sigvec *)0);
257 sv.sv_handler = reapchild;
258 sigvec(SIGCHLD, &sv, (struct sigvec *)0);
259
260 {
261 /* space for daemons to overwrite environment for ps */
262 #define DUMMYSIZE 100
263 char dummy[DUMMYSIZE];
264
265 (void)memset(dummy, 'x', sizeof(DUMMYSIZE) - 1);
266 dummy[DUMMYSIZE - 1] = '\0';
267 (void)setenv("inetd_dummy", dummy, 1);
268 }
269
270 for (;;) {
271 int n, ctrl;
272 fd_set readable;
273
274 if (nsock == 0) {
275 (void) sigblock(SIGBLOCK);
276 while (nsock == 0)
277 sigpause(0L);
278 (void) sigsetmask(0L);
279 }
280 readable = allsock;
281 if ((n = select(maxsock + 1, &readable, (fd_set *)0,
282 (fd_set *)0, (struct timeval *)0)) <= 0) {
283 if (n < 0 && errno != EINTR)
284 syslog(LOG_WARNING, "select: %m");
285 sleep(1);
286 continue;
287 }
288 for (sep = servtab; n && sep; sep = sep->se_next)
289 if (sep->se_fd != -1 && FD_ISSET(sep->se_fd, &readable)) {
290 n--;
291 if (debug)
292 fprintf(stderr, "someone wants %s\n",
293 sep->se_service);
294 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) {
295 ctrl = accept(sep->se_fd, (struct sockaddr *)0,
296 (int *)0);
297 if (debug)
298 fprintf(stderr, "accept, ctrl %d\n", ctrl);
299 if (ctrl < 0) {
300 if (errno != EINTR)
301 syslog(LOG_WARNING,
302 "accept (for %s): %m",
303 sep->se_service);
304 continue;
305 }
306 /*
307 * Call tcpmux to find the real service to exec.
308 */
309 if (sep->se_bi &&
310 sep->se_bi->bi_fn == (void (*)()) tcpmux) {
311 sep = tcpmux(ctrl);
312 if (sep == NULL) {
313 close(ctrl);
314 continue;
315 }
316 }
317 } else
318 ctrl = sep->se_fd;
319 (void) sigblock(SIGBLOCK);
320 pid = 0;
321 dofork = (sep->se_bi == 0 || sep->se_bi->bi_fork);
322 if (dofork) {
323 if (sep->se_count++ == 0)
324 (void)gettimeofday(&sep->se_time,
325 (struct timezone *)0);
326 else if (sep->se_count >= toomany) {
327 struct timeval now;
328
329 (void)gettimeofday(&now, (struct timezone *)0);
330 if (now.tv_sec - sep->se_time.tv_sec >
331 CNT_INTVL) {
332 sep->se_time = now;
333 sep->se_count = 1;
334 } else {
335 syslog(LOG_ERR,
336 "%s/%s server failing (looping), service terminated",
337 sep->se_service, sep->se_proto);
338 close_sep(sep);
339 sigsetmask(0L);
340 if (!timingout) {
341 timingout = 1;
342 alarm(RETRYTIME);
343 }
344 continue;
345 }
346 }
347 pid = fork();
348 }
349 if (pid < 0) {
350 syslog(LOG_ERR, "fork: %m");
351 if (!sep->se_wait &&
352 sep->se_socktype == SOCK_STREAM)
353 close(ctrl);
354 sigsetmask(0L);
355 sleep(1);
356 continue;
357 }
358 if (pid && sep->se_wait) {
359 sep->se_wait = pid;
360 if (sep->se_fd >= 0) {
361 FD_CLR(sep->se_fd, &allsock);
362 nsock--;
363 }
364 }
365 sigsetmask(0L);
366 if (pid == 0) {
367 if (debug && dofork)
368 setsid();
369 if (dofork) {
370 if (debug)
371 fprintf(stderr, "+ Closing from %d\n",
372 maxsock);
373 for (tmpint = maxsock; tmpint > 2; tmpint--)
374 if (tmpint != ctrl)
375 close(tmpint);
376 }
377 if (sep->se_bi)
378 (*sep->se_bi->bi_fn)(ctrl, sep);
379 else {
380 if (debug)
381 fprintf(stderr, "%d execl %s\n",
382 getpid(), sep->se_server);
383 dup2(ctrl, 0);
384 close(ctrl);
385 dup2(0, 1);
386 dup2(0, 2);
387 if ((pwd = getpwnam(sep->se_user)) == NULL) {
388 syslog(LOG_ERR,
389 "%s/%s: %s: No such user",
390 sep->se_service, sep->se_proto,
391 sep->se_user);
392 if (sep->se_socktype != SOCK_STREAM)
393 recv(0, buf, sizeof (buf), 0);
394 _exit(1);
395 }
396 if (pwd->pw_uid) {
397 if (setgid(pwd->pw_gid) < 0) {
398 syslog(LOG_ERR,
399 "%s: can't set gid %d: %m",
400 sep->se_service, pwd->pw_gid);
401 _exit(1);
402 }
403 (void) initgroups(pwd->pw_name,
404 pwd->pw_gid);
405 if (setuid(pwd->pw_uid) < 0) {
406 syslog(LOG_ERR,
407 "%s: can't set uid %d: %m",
408 sep->se_service, pwd->pw_uid);
409 _exit(1);
410 }
411 }
412 execv(sep->se_server, sep->se_argv);
413 if (sep->se_socktype != SOCK_STREAM)
414 recv(0, buf, sizeof (buf), 0);
415 syslog(LOG_ERR,
416 "cannot execute %s: %m", sep->se_server);
417 _exit(1);
418 }
419 }
420 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
421 close(ctrl);
422 }
423 }
424 }
425
426 void
reapchild(signo)427 reapchild(signo)
428 int signo;
429 {
430 int status;
431 pid_t pid;
432 struct servtab *sep;
433
434 for (;;) {
435 pid = wait3(&status, WNOHANG, (struct rusage *)0);
436 if (pid <= 0)
437 break;
438 if (debug)
439 fprintf(stderr, "%d reaped, status %#x\n",
440 pid, status);
441 for (sep = servtab; sep; sep = sep->se_next)
442 if (sep->se_wait == pid) {
443 if (status)
444 syslog(LOG_WARNING,
445 "%s: exit status 0x%x",
446 sep->se_server, status);
447 if (debug)
448 fprintf(stderr, "restored %s, fd %d\n",
449 sep->se_service, sep->se_fd);
450 FD_SET(sep->se_fd, &allsock);
451 nsock++;
452 sep->se_wait = 1;
453 }
454 }
455 }
456
457 void
config(signo)458 config(signo)
459 int signo;
460 {
461 struct servtab *sep, *cp, **sepp;
462 struct passwd *pwd;
463 long omask;
464
465 if (!setconfig()) {
466 syslog(LOG_ERR, "%s: %m", CONFIG);
467 return;
468 }
469 for (sep = servtab; sep; sep = sep->se_next)
470 sep->se_checked = 0;
471 while (cp = getconfigent()) {
472 if ((pwd = getpwnam(cp->se_user)) == NULL) {
473 syslog(LOG_ERR,
474 "%s/%s: No such user '%s', service ignored",
475 cp->se_service, cp->se_proto, cp->se_user);
476 continue;
477 }
478 for (sep = servtab; sep; sep = sep->se_next)
479 if (strcmp(sep->se_service, cp->se_service) == 0 &&
480 strcmp(sep->se_proto, cp->se_proto) == 0)
481 break;
482 if (sep != 0) {
483 int i;
484
485 omask = sigblock(SIGBLOCK);
486 /*
487 * sep->se_wait may be holding the pid of a daemon
488 * that we're waiting for. If so, don't overwrite
489 * it unless the config file explicitly says don't
490 * wait.
491 */
492 if (cp->se_bi == 0 &&
493 (sep->se_wait == 1 || cp->se_wait == 0))
494 sep->se_wait = cp->se_wait;
495 #define SWAP(a, b) { char *c = a; a = b; b = c; }
496 if (cp->se_user)
497 SWAP(sep->se_user, cp->se_user);
498 if (cp->se_server)
499 SWAP(sep->se_server, cp->se_server);
500 for (i = 0; i < MAXARGV; i++)
501 SWAP(sep->se_argv[i], cp->se_argv[i]);
502 sigsetmask(omask);
503 freeconfig(cp);
504 if (debug)
505 print_service("REDO", sep);
506 } else {
507 sep = enter(cp);
508 if (debug)
509 print_service("ADD ", sep);
510 }
511 sep->se_checked = 1;
512 if (ISMUX(sep)) {
513 sep->se_fd = -1;
514 continue;
515 }
516 sp = getservbyname(sep->se_service, sep->se_proto);
517 if (sp == 0) {
518 syslog(LOG_ERR, "%s/%s: unknown service",
519 sep->se_service, sep->se_proto);
520 sep->se_checked = 0;
521 continue;
522 }
523 if (sp->s_port != sep->se_ctrladdr.sin_port) {
524 sep->se_ctrladdr.sin_family = AF_INET;
525 sep->se_ctrladdr.sin_port = sp->s_port;
526 if (sep->se_fd >= 0)
527 close_sep(sep);
528 }
529 if (sep->se_fd == -1)
530 setup(sep);
531 }
532 endconfig();
533 /*
534 * Purge anything not looked at above.
535 */
536 omask = sigblock(SIGBLOCK);
537 sepp = &servtab;
538 while (sep = *sepp) {
539 if (sep->se_checked) {
540 sepp = &sep->se_next;
541 continue;
542 }
543 *sepp = sep->se_next;
544 if (sep->se_fd >= 0)
545 close_sep(sep);
546 if (debug)
547 print_service("FREE", sep);
548 freeconfig(sep);
549 free((char *)sep);
550 }
551 (void) sigsetmask(omask);
552 }
553
554 void
retry(signo)555 retry(signo)
556 int signo;
557 {
558 struct servtab *sep;
559
560 timingout = 0;
561 for (sep = servtab; sep; sep = sep->se_next)
562 if (sep->se_fd == -1)
563 setup(sep);
564 }
565
566 void
setup(sep)567 setup(sep)
568 struct servtab *sep;
569 {
570 int on = 1;
571
572 if ((sep->se_fd = socket(AF_INET, sep->se_socktype, 0)) < 0) {
573 if (debug)
574 fprintf(stderr, "socket failed on %s/%s: %s\n",
575 sep->se_service, sep->se_proto,
576 strerror(errno));
577 syslog(LOG_ERR, "%s/%s: socket: %m",
578 sep->se_service, sep->se_proto);
579 return;
580 }
581 #define turnon(fd, opt) \
582 setsockopt(fd, SOL_SOCKET, opt, (char *)&on, sizeof (on))
583 if (strcmp(sep->se_proto, "tcp") == 0 && (options & SO_DEBUG) &&
584 turnon(sep->se_fd, SO_DEBUG) < 0)
585 syslog(LOG_ERR, "setsockopt (SO_DEBUG): %m");
586 if (turnon(sep->se_fd, SO_REUSEADDR) < 0)
587 syslog(LOG_ERR, "setsockopt (SO_REUSEADDR): %m");
588 #undef turnon
589 if (bind(sep->se_fd, (struct sockaddr *)&sep->se_ctrladdr,
590 sizeof (sep->se_ctrladdr)) < 0) {
591 if (debug)
592 fprintf(stderr, "bind failed on %s/%s: %s\n",
593 sep->se_service, sep->se_proto,
594 strerror(errno));
595 syslog(LOG_ERR, "%s/%s: bind: %m",
596 sep->se_service, sep->se_proto);
597 (void) close(sep->se_fd);
598 sep->se_fd = -1;
599 if (!timingout) {
600 timingout = 1;
601 alarm(RETRYTIME);
602 }
603 return;
604 }
605 if (sep->se_socktype == SOCK_STREAM)
606 listen(sep->se_fd, 10);
607 FD_SET(sep->se_fd, &allsock);
608 nsock++;
609 if (sep->se_fd > maxsock)
610 maxsock = sep->se_fd;
611 if (debug) {
612 fprintf(stderr, "registered %s on %d\n",
613 sep->se_server, sep->se_fd);
614 }
615 }
616
617 /*
618 * Finish with a service and its socket.
619 */
620 void
close_sep(sep)621 close_sep(sep)
622 struct servtab *sep;
623 {
624 if (sep->se_fd >= 0) {
625 nsock--;
626 FD_CLR(sep->se_fd, &allsock);
627 (void) close(sep->se_fd);
628 sep->se_fd = -1;
629 }
630 sep->se_count = 0;
631 /*
632 * Don't keep the pid of this running deamon: when reapchild()
633 * reaps this pid, it would erroneously increment nsock.
634 */
635 if (sep->se_wait > 1)
636 sep->se_wait = 1;
637 }
638
639 struct servtab *
enter(cp)640 enter(cp)
641 struct servtab *cp;
642 {
643 struct servtab *sep;
644 long omask;
645
646 sep = (struct servtab *)malloc(sizeof (*sep));
647 if (sep == (struct servtab *)0) {
648 syslog(LOG_ERR, "Out of memory.");
649 exit(-1);
650 }
651 *sep = *cp;
652 sep->se_fd = -1;
653 omask = sigblock(SIGBLOCK);
654 sep->se_next = servtab;
655 servtab = sep;
656 sigsetmask(omask);
657 return (sep);
658 }
659
660 FILE *fconfig = NULL;
661 struct servtab serv;
662 char line[LINE_MAX];
663
664 int
setconfig()665 setconfig()
666 {
667
668 if (fconfig != NULL) {
669 fseek(fconfig, 0L, SEEK_SET);
670 return (1);
671 }
672 fconfig = fopen(CONFIG, "r");
673 return (fconfig != NULL);
674 }
675
676 void
endconfig()677 endconfig()
678 {
679 if (fconfig) {
680 (void) fclose(fconfig);
681 fconfig = NULL;
682 }
683 }
684
685 struct servtab *
getconfigent()686 getconfigent()
687 {
688 struct servtab *sep = &serv;
689 int argc;
690 char *cp, *arg;
691 static char TCPMUX_TOKEN[] = "tcpmux/";
692 #define MUX_LEN (sizeof(TCPMUX_TOKEN)-1)
693
694 more:
695 while ((cp = nextline(fconfig)) && (*cp == '#' || *cp == '\0'))
696 ;
697 if (cp == NULL)
698 return ((struct servtab *)0);
699 /*
700 * clear the static buffer, since some fields (se_ctrladdr,
701 * for example) don't get initialized here.
702 */
703 memset((caddr_t)sep, 0, sizeof *sep);
704 arg = skip(&cp);
705 if (cp == NULL) {
706 /* got an empty line containing just blanks/tabs. */
707 goto more;
708 }
709 if (strncmp(arg, TCPMUX_TOKEN, MUX_LEN) == 0) {
710 char *c = arg + MUX_LEN;
711 if (*c == '+') {
712 sep->se_type = MUXPLUS_TYPE;
713 c++;
714 } else
715 sep->se_type = MUX_TYPE;
716 sep->se_service = newstr(c);
717 } else {
718 sep->se_service = newstr(arg);
719 sep->se_type = NORM_TYPE;
720 }
721 arg = sskip(&cp);
722 if (strcmp(arg, "stream") == 0)
723 sep->se_socktype = SOCK_STREAM;
724 else if (strcmp(arg, "dgram") == 0)
725 sep->se_socktype = SOCK_DGRAM;
726 else if (strcmp(arg, "rdm") == 0)
727 sep->se_socktype = SOCK_RDM;
728 else if (strcmp(arg, "seqpacket") == 0)
729 sep->se_socktype = SOCK_SEQPACKET;
730 else if (strcmp(arg, "raw") == 0)
731 sep->se_socktype = SOCK_RAW;
732 else
733 sep->se_socktype = -1;
734 sep->se_proto = newstr(sskip(&cp));
735 arg = sskip(&cp);
736 sep->se_wait = strcmp(arg, "wait") == 0;
737 if (ISMUX(sep)) {
738 /*
739 * Silently enforce "nowait" for TCPMUX services since
740 * they don't have an assigned port to listen on.
741 */
742 sep->se_wait = 0;
743
744 if (strcmp(sep->se_proto, "tcp")) {
745 syslog(LOG_ERR,
746 "%s: bad protocol for tcpmux service %s",
747 CONFIG, sep->se_service);
748 goto more;
749 }
750 if (sep->se_socktype != SOCK_STREAM) {
751 syslog(LOG_ERR,
752 "%s: bad socket type for tcpmux service %s",
753 CONFIG, sep->se_service);
754 goto more;
755 }
756 }
757 sep->se_user = newstr(sskip(&cp));
758 sep->se_server = newstr(sskip(&cp));
759 if (strcmp(sep->se_server, "internal") == 0) {
760 struct biltin *bi;
761
762 for (bi = biltins; bi->bi_service; bi++)
763 if (bi->bi_socktype == sep->se_socktype &&
764 strcmp(bi->bi_service, sep->se_service) == 0)
765 break;
766 if (bi->bi_service == 0) {
767 syslog(LOG_ERR, "internal service %s unknown",
768 sep->se_service);
769 goto more;
770 }
771 sep->se_bi = bi;
772 sep->se_wait = bi->bi_wait;
773 } else
774 sep->se_bi = NULL;
775 argc = 0;
776 for (arg = skip(&cp); cp; arg = skip(&cp))
777 if (argc < MAXARGV)
778 sep->se_argv[argc++] = newstr(arg);
779 while (argc <= MAXARGV)
780 sep->se_argv[argc++] = NULL;
781 return (sep);
782 }
783
784 void
freeconfig(cp)785 freeconfig(cp)
786 struct servtab *cp;
787 {
788 int i;
789
790 if (cp->se_service)
791 free(cp->se_service);
792 if (cp->se_proto)
793 free(cp->se_proto);
794 if (cp->se_user)
795 free(cp->se_user);
796 if (cp->se_server)
797 free(cp->se_server);
798 for (i = 0; i < MAXARGV; i++)
799 if (cp->se_argv[i])
800 free(cp->se_argv[i]);
801 }
802
803
804 /*
805 * Safe skip - if skip returns null, log a syntax error in the
806 * configuration file and exit.
807 */
808 char *
sskip(cpp)809 sskip(cpp)
810 char **cpp;
811 {
812 char *cp;
813
814 cp = skip(cpp);
815 if (cp == NULL) {
816 syslog(LOG_ERR, "%s: syntax error", CONFIG);
817 exit(-1);
818 }
819 return (cp);
820 }
821
822 char *
skip(cpp)823 skip(cpp)
824 char **cpp;
825 {
826 char *cp = *cpp;
827 char *start;
828
829 again:
830 while (*cp == ' ' || *cp == '\t')
831 cp++;
832 if (*cp == '\0') {
833 int c;
834
835 c = getc(fconfig);
836 (void) ungetc(c, fconfig);
837 if (c == ' ' || c == '\t')
838 if (cp = nextline(fconfig))
839 goto again;
840 *cpp = (char *)0;
841 return ((char *)0);
842 }
843 start = cp;
844 while (*cp && *cp != ' ' && *cp != '\t')
845 cp++;
846 if (*cp != '\0')
847 *cp++ = '\0';
848 *cpp = cp;
849 return (start);
850 }
851
852 char *
nextline(fd)853 nextline(fd)
854 FILE *fd;
855 {
856 char *cp;
857
858 if (fgets(line, sizeof (line), fd) == NULL)
859 return ((char *)0);
860 cp = strchr(line, '\n');
861 if (cp)
862 *cp = '\0';
863 return (line);
864 }
865
866 char *
newstr(cp)867 newstr(cp)
868 char *cp;
869 {
870 if (cp = strdup(cp ? cp : ""))
871 return (cp);
872 syslog(LOG_ERR, "strdup: %m");
873 exit(-1);
874 }
875
876 void
setproctitle(a,s)877 setproctitle(a, s)
878 char *a;
879 int s;
880 {
881 int size;
882 char *cp;
883 struct sockaddr_in sin;
884 char buf[80];
885
886 cp = Argv[0];
887 size = sizeof(sin);
888 if (getpeername(s, (struct sockaddr *)&sin, &size) == 0)
889 (void) sprintf(buf, "-%s [%s]", a, inet_ntoa(sin.sin_addr));
890 else
891 (void) sprintf(buf, "-%s", a);
892 strncpy(cp, buf, LastArg - cp);
893 cp += strlen(cp);
894 while (cp < LastArg)
895 *cp++ = ' ';
896 }
897
898 /*
899 * Internet services provided internally by inetd:
900 */
901 #define BUFSIZE 8192
902
903 /* ARGSUSED */
904 void
echo_stream(s,sep)905 echo_stream(s, sep) /* Echo service -- echo data back */
906 int s;
907 struct servtab *sep;
908 {
909 char buffer[BUFSIZE];
910 int i;
911
912 setproctitle(sep->se_service, s);
913 while ((i = read(s, buffer, sizeof(buffer))) > 0 &&
914 write(s, buffer, i) > 0)
915 ;
916 exit(0);
917 }
918
919 /* ARGSUSED */
920 void
echo_dg(s,sep)921 echo_dg(s, sep) /* Echo service -- echo data back */
922 int s;
923 struct servtab *sep;
924 {
925 char buffer[BUFSIZE];
926 int i, size;
927 struct sockaddr sa;
928
929 size = sizeof(sa);
930 if ((i = recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size)) < 0)
931 return;
932 (void) sendto(s, buffer, i, 0, &sa, sizeof(sa));
933 }
934
935 /* ARGSUSED */
936 void
discard_stream(s,sep)937 discard_stream(s, sep) /* Discard service -- ignore data */
938 int s;
939 struct servtab *sep;
940 {
941 int ret;
942 char buffer[BUFSIZE];
943
944 setproctitle(sep->se_service, s);
945 while (1) {
946 while ((ret = read(s, buffer, sizeof(buffer))) > 0)
947 ;
948 if (ret == 0 || errno != EINTR)
949 break;
950 }
951 exit(0);
952 }
953
954 /* ARGSUSED */
955 void
discard_dg(s,sep)956 discard_dg(s, sep) /* Discard service -- ignore data */
957 int s;
958 struct servtab *sep;
959 {
960 char buffer[BUFSIZE];
961
962 (void) read(s, buffer, sizeof(buffer));
963 }
964
965 #include <ctype.h>
966 #define LINESIZ 72
967 char ring[128];
968 char *endring;
969
970 void
initring()971 initring()
972 {
973 int i;
974
975 endring = ring;
976
977 for (i = 0; i <= 128; ++i)
978 if (isprint(i))
979 *endring++ = i;
980 }
981
982 /* ARGSUSED */
983 void
chargen_stream(s,sep)984 chargen_stream(s, sep) /* Character generator */
985 int s;
986 struct servtab *sep;
987 {
988 int len;
989 char *rs, text[LINESIZ+2];
990
991 setproctitle(sep->se_service, s);
992
993 if (!endring) {
994 initring();
995 rs = ring;
996 }
997
998 text[LINESIZ] = '\r';
999 text[LINESIZ + 1] = '\n';
1000 for (rs = ring;;) {
1001 if ((len = endring - rs) >= LINESIZ)
1002 memmove(text, rs, LINESIZ);
1003 else {
1004 memmove(text, rs, len);
1005 memmove(text + len, ring, LINESIZ - len);
1006 }
1007 if (++rs == endring)
1008 rs = ring;
1009 if (write(s, text, sizeof(text)) != sizeof(text))
1010 break;
1011 }
1012 exit(0);
1013 }
1014
1015 /* ARGSUSED */
1016 void
chargen_dg(s,sep)1017 chargen_dg(s, sep) /* Character generator */
1018 int s;
1019 struct servtab *sep;
1020 {
1021 struct sockaddr sa;
1022 static char *rs;
1023 int len, size;
1024 char text[LINESIZ+2];
1025
1026 if (endring == 0) {
1027 initring();
1028 rs = ring;
1029 }
1030
1031 size = sizeof(sa);
1032 if (recvfrom(s, text, sizeof(text), 0, &sa, &size) < 0)
1033 return;
1034
1035 if ((len = endring - rs) >= LINESIZ)
1036 memmove(text, rs, LINESIZ);
1037 else {
1038 memmove(text, rs, len);
1039 memmove(text + len, ring, LINESIZ - len);
1040 }
1041 if (++rs == endring)
1042 rs = ring;
1043 text[LINESIZ] = '\r';
1044 text[LINESIZ + 1] = '\n';
1045 (void) sendto(s, text, sizeof(text), 0, &sa, sizeof(sa));
1046 }
1047
1048 /*
1049 * Return a machine readable date and time, in the form of the
1050 * number of seconds since midnight, Jan 1, 1900. Since gettimeofday
1051 * returns the number of seconds since midnight, Jan 1, 1970,
1052 * we must add 2208988800 seconds to this figure to make up for
1053 * some seventy years Bell Labs was asleep.
1054 */
1055
1056 long
machtime()1057 machtime()
1058 {
1059 struct timeval tv;
1060
1061 if (gettimeofday(&tv, (struct timezone *)0) < 0) {
1062 if (debug)
1063 fprintf(stderr, "Unable to get time of day\n");
1064 return (0L);
1065 }
1066 #define OFFSET ((u_long)25567 * 24*60*60)
1067 return (htonl((long)(tv.tv_sec + OFFSET)));
1068 #undef OFFSET
1069 }
1070
1071 /* ARGSUSED */
1072 void
machtime_stream(s,sep)1073 machtime_stream(s, sep)
1074 int s;
1075 struct servtab *sep;
1076 {
1077 long result;
1078
1079 result = machtime();
1080 (void) write(s, (char *) &result, sizeof(result));
1081 }
1082
1083 /* ARGSUSED */
1084 void
machtime_dg(s,sep)1085 machtime_dg(s, sep)
1086 int s;
1087 struct servtab *sep;
1088 {
1089 long result;
1090 struct sockaddr sa;
1091 int size;
1092
1093 size = sizeof(sa);
1094 if (recvfrom(s, (char *)&result, sizeof(result), 0, &sa, &size) < 0)
1095 return;
1096 result = machtime();
1097 (void) sendto(s, (char *) &result, sizeof(result), 0, &sa, sizeof(sa));
1098 }
1099
1100 /* ARGSUSED */
1101 void
daytime_stream(s,sep)1102 daytime_stream(s, sep) /* Return human-readable time of day */
1103 int s;
1104 struct servtab *sep;
1105 {
1106 char buffer[256];
1107 time_t clock;
1108
1109 clock = time((time_t *) 0);
1110
1111 (void) sprintf(buffer, "%.24s\r\n", ctime(&clock));
1112 (void) write(s, buffer, strlen(buffer));
1113 }
1114
1115 /* ARGSUSED */
1116 void
daytime_dg(s,sep)1117 daytime_dg(s, sep) /* Return human-readable time of day */
1118 int s;
1119 struct servtab *sep;
1120 {
1121 char buffer[256];
1122 time_t clock;
1123 struct sockaddr sa;
1124 int size;
1125
1126 clock = time((time_t *) 0);
1127
1128 size = sizeof(sa);
1129 if (recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size) < 0)
1130 return;
1131 (void) sprintf(buffer, "%.24s\r\n", ctime(&clock));
1132 (void) sendto(s, buffer, strlen(buffer), 0, &sa, sizeof(sa));
1133 }
1134
1135 /*
1136 * print_service:
1137 * Dump relevant information to stderr
1138 */
1139 void
print_service(action,sep)1140 print_service(action, sep)
1141 char *action;
1142 struct servtab *sep;
1143 {
1144 fprintf(stderr,
1145 "%s: %s proto=%s, wait=%d, user=%s builtin=%x server=%s\n",
1146 action, sep->se_service, sep->se_proto,
1147 sep->se_wait, sep->se_user, (int)sep->se_bi, sep->se_server);
1148 }
1149
1150 /*
1151 * Based on TCPMUX.C by Mark K. Lottor November 1988
1152 * sri-nic::ps:<mkl>tcpmux.c
1153 */
1154
1155
1156 static int /* # of characters upto \r,\n or \0 */
getline(fd,buf,len)1157 getline(fd, buf, len)
1158 int fd;
1159 char *buf;
1160 int len;
1161 {
1162 int count = 0, n;
1163
1164 do {
1165 n = read(fd, buf, len-count);
1166 if (n == 0)
1167 return (count);
1168 if (n < 0)
1169 return (-1);
1170 while (--n >= 0) {
1171 if (*buf == '\r' || *buf == '\n' || *buf == '\0')
1172 return (count);
1173 count++;
1174 buf++;
1175 }
1176 } while (count < len);
1177 return (count);
1178 }
1179
1180 #define MAX_SERV_LEN (256+2) /* 2 bytes for \r\n */
1181
1182 #define strwrite(fd, buf) (void) write(fd, buf, sizeof(buf)-1)
1183
1184 struct servtab *
tcpmux(s)1185 tcpmux(s)
1186 int s;
1187 {
1188 struct servtab *sep;
1189 char service[MAX_SERV_LEN+1];
1190 int len;
1191
1192 /* Get requested service name */
1193 if ((len = getline(s, service, MAX_SERV_LEN)) < 0) {
1194 strwrite(s, "-Error reading service name\r\n");
1195 return (NULL);
1196 }
1197 service[len] = '\0';
1198
1199 if (debug)
1200 fprintf(stderr, "tcpmux: someone wants %s\n", service);
1201
1202 /*
1203 * Help is a required command, and lists available services,
1204 * one per line.
1205 */
1206 if (!strcasecmp(service, "help")) {
1207 for (sep = servtab; sep; sep = sep->se_next) {
1208 if (!ISMUX(sep))
1209 continue;
1210 (void)write(s,sep->se_service,strlen(sep->se_service));
1211 strwrite(s, "\r\n");
1212 }
1213 return (NULL);
1214 }
1215
1216 /* Try matching a service in inetd.conf with the request */
1217 for (sep = servtab; sep; sep = sep->se_next) {
1218 if (!ISMUX(sep))
1219 continue;
1220 if (!strcasecmp(service, sep->se_service)) {
1221 if (ISMUXPLUS(sep)) {
1222 strwrite(s, "+Go\r\n");
1223 }
1224 return (sep);
1225 }
1226 }
1227 strwrite(s, "-Service not available\r\n");
1228 return (NULL);
1229 }
1230