xref: /titanic_50/usr/src/cmd/ttymon/ttymon.c (revision 0e42dee69ed771bf604dd1789fca9d77b5bbe302)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 
33 #include <stdio_ext.h>
34 #include <stdlib.h>
35 #include <fcntl.h>
36 #include <errno.h>
37 #include <poll.h>
38 #include <string.h>
39 #include <signal.h>
40 #include <sys/types.h>
41 #include <sys/stat.h>
42 #include <sys/stropts.h>
43 #include <sys/resource.h>
44 #include <sys/termios.h>
45 #include <pwd.h>
46 #include <grp.h>
47 #include <unistd.h>
48 #include <ulimit.h>
49 
50 #include "sac.h"
51 #include "ttymon.h"
52 #include "tmstruct.h"
53 #include "tmextern.h"
54 
55 static	int	Initialized;
56 
57 extern	int	Retry;
58 extern	struct	pollfd	*Pollp;
59 static	void	initialize();
60 static	void	open_all();
61 static	int	set_poll();
62 static	int	check_spawnlimit();
63 static	int	mod_ttydefs();
64 
65 void	open_device();
66 void	set_softcar();
67 
68 extern	int	check_session();
69 extern	void	sigalarm();
70 extern	void	revokedevaccess(char *, uid_t, gid_t, mode_t);
71 /* can't include libdevinfo.h */
72 extern int di_devperm_logout(const char *);
73 
74 /*
75  * 	ttymon	- a port monitor under SAC
76  *		- monitor ports, set terminal modes, baud rate
77  *		  and line discipline for the port
78  *		- invoke service on port if connection request received
79  *		- Usage: ttymon
80  *			 ttymon -g [options]
81  *			 Valid options are
82  *			 -h
83  *			 -d device
84  *			 -l ttylabel
85  *			 -t timeout
86  *			 -m modules
87  *			 -p prompt
88  *
89  *		- ttymon without args is invoked by SAC
90  *		- ttymon -g is invoked by process that needs to
91  *		  have login service on the fly
92  */
93 
94 int
95 main(int argc, char *argv[])
96 {
97 	int	nfds;
98 	extern	char	*lastname();
99 
100 	/*
101 	 * Only the superuser should execute this command.
102 	 */
103 	if (getuid() != 0)
104 		return (1);	/*NOTREACHED*/
105 
106 	if ((argc > 1) || (strcmp(lastname(argv[0]), "getty") == 0)) {
107 		ttymon_express(argc, argv);
108 		return (1);	/*NOTREACHED*/
109 	}
110 	/* remember original signal mask and dispositions */
111 	(void) sigprocmask(SIG_SETMASK, NULL, &Origmask);
112 	(void) sigaction(SIGINT, &Sigint, NULL);
113 	(void) sigaction(SIGALRM, &Sigalrm, NULL);
114 	(void) sigaction(SIGPOLL, &Sigpoll, NULL);
115 	(void) sigaction(SIGCLD, &Sigcld, NULL);
116 	(void) sigaction(SIGTERM, &Sigterm, NULL);
117 #ifdef	DEBUG
118 	(void) sigaction(SIGUSR1, &Sigusr1, NULL);
119 	(void) sigaction(SIGUSR2, &Sigusr2, NULL);
120 #endif
121 	initialize();
122 
123 	for (;;) {
124 		nfds = set_poll(Pollp);
125 		if (!Reread_flag) {
126 			if (nfds > 0)
127 				do_poll(Pollp, nfds);
128 			else
129 				(void) pause();
130 		}
131 		/*
132 		 * READDB messages may arrive during poll or pause.
133 		 * So the flag needs to be checked again.
134 		 */
135 		if (Reread_flag) {
136 			Reread_flag = FALSE;
137 			re_read();
138 		}
139 		while (Retry) {
140 			Retry = FALSE;
141 			open_all();
142 		}
143 	}
144 }
145 
146 static	void
147 initialize()
148 {
149 	struct	pmtab	*tp;
150 	register struct passwd *pwdp;
151 	register struct	group	*gp;
152 	struct	rlimit rlimit;
153 	extern	struct	rlimit	Rlimit;
154 	extern	 uid_t	Uucp_uid;
155 	extern	 gid_t	Tty_gid;
156 
157 #ifdef 	DEBUG
158 	extern	opendebug();
159 #endif
160 	Initialized = FALSE;
161 	/*
162 	 * get_environ() must be called first,
163 	 * otherwise we don't know where the log file is
164 	 */
165 	get_environ();
166 	openttymonlog();
167 	openpid();
168 	openpipes();
169 	setup_PCpipe();
170 
171 	log("PMTAG: %s", Tag);
172 	log("Starting state: %s",
173 	    (State == PM_ENABLED) ? "enabled" : "disabled");
174 
175 #ifdef 	DEBUG
176 	opendebug(FALSE);
177 	debug("***** ttymon in initialize *****");
178 	log("debug mode is \t on");
179 #endif
180 
181 	catch_signals();
182 
183 	/* register to receive SIGPOLL when data comes to pmpipe */
184 	if (ioctl(Pfd, I_SETSIG, S_INPUT) < 0)
185 		fatal("I_SETSIG on pmpipe failed: %s", strerror(errno));
186 
187 	sacpoll(); /* this is needed because there may be data already */
188 
189 	Maxfiles = (int)ulimit(4, 0L);	/* get max number of open files */
190 	if (Maxfiles < 0)
191 		fatal("ulimit(4,0L) failed: %s", strerror(errno));
192 
193 	if (getrlimit(RLIMIT_NOFILE, &Rlimit) == -1)
194 		fatal("getrlimit failed: %s", strerror(errno));
195 
196 	rlimit.rlim_cur = rlimit.rlim_max = Rlimit.rlim_max;
197 	if (setrlimit(RLIMIT_NOFILE, &rlimit) == -1)
198 		fatal("setrlimit failed: %s", strerror(errno));
199 
200 	(void) enable_extended_FILE_stdio(-1, -1);
201 
202 	Maxfiles = rlimit.rlim_cur;
203 	Maxfds = Maxfiles - FILE_RESERVED;
204 
205 	log("max open files = %d", Maxfiles);
206 	log("max ports ttymon can monitor = %d", Maxfds);
207 
208 	read_pmtab();
209 
210 	/*
211 	 * setup poll array
212 	 * 	- we allocate 10 extra pollfd so that
213 	 *	  we do not have to re-malloc when there is
214 	 *	  minor fluctuation in Nentries
215 	 */
216 	Npollfd = Nentries + 10;
217 	if (Npollfd > Maxfds)
218 		Npollfd = Maxfds;
219 	if ((Pollp = (struct pollfd *)
220 	    malloc((unsigned)(Npollfd * sizeof (struct pollfd))))
221 	    == (struct pollfd *)NULL)
222 		fatal("malloc for Pollp failed");
223 
224 	(void) mod_ttydefs();	/* just to initialize Mtime */
225 	if (check_version(TTYDEFS_VERS, TTYDEFS) != 0)
226 		fatal("check /etc/ttydefs version failed");
227 
228 	read_ttydefs(NULL, FALSE);
229 
230 	/* initialize global variables, Uucp_uid & Tty_gid */
231 	if ((pwdp = getpwnam(UUCP)) != NULL)
232 		Uucp_uid = pwdp->pw_uid;
233 	if ((gp = getgrnam(TTY)) == NULL)
234 		log("no group entry for <tty>, default is used");
235 	else
236 		Tty_gid = gp->gr_gid;
237 	endgrent();
238 	endpwent();
239 #ifdef	DEBUG
240 	debug("Uucp_uid = %ld, Tty_gid = %ld", Uucp_uid, Tty_gid);
241 #endif
242 
243 	log("Initialization Completed");
244 
245 	/* open the devices ttymon monitors */
246 	Retry = TRUE;
247 	while (Retry) {
248 		Retry = FALSE;
249 		for (tp = PMtab; tp; tp = tp->p_next) {
250 			if ((tp->p_status > 0) && (tp->p_fd == 0) &&
251 			    (tp->p_pid == 0) && !(tp->p_ttyflags & I_FLAG) &&
252 			    (!((State == PM_DISABLED) &&
253 			    ((tp->p_dmsg == NULL)||(*(tp->p_dmsg) == '\0'))))) {
254 				open_device(tp);
255 				if (tp->p_fd > 0)
256 					got_carrier(tp);
257 			}
258 		}
259 	}
260 	Initialized = TRUE;
261 }
262 
263 /*
264  *	open_all - open devices in pmtab if the entry is
265  *	         - valid, fd = 0, and pid = 0
266  */
267 static void
268 open_all()
269 {
270 	struct	pmtab	*tp;
271 	int	check_modtime;
272 	static	void	free_defs();
273 	sigset_t cset;
274 	sigset_t tset;
275 
276 #ifdef	DEBUG
277 	debug("in open_all");
278 #endif
279 	check_modtime = TRUE;
280 
281 	for (tp = PMtab; tp; tp = tp->p_next) {
282 		if ((tp->p_status > 0) && (tp->p_fd == 0) &&
283 		    (tp->p_pid == 0) &&
284 		    !(tp->p_ttyflags & I_FLAG) && (!((State == PM_DISABLED) &&
285 		    ((tp->p_dmsg == NULL)||(*(tp->p_dmsg) == '\0'))))) {
286 			/*
287 			 * if we have not check modification time and
288 			 * /etc/ttydefs was modified, need to re-read it
289 			 */
290 			if (check_modtime && mod_ttydefs()) {
291 				check_modtime = FALSE;
292 				(void) sigprocmask(SIG_SETMASK, NULL, &cset);
293 				tset = cset;
294 				(void) sigaddset(&tset, SIGCLD);
295 				(void) sigprocmask(SIG_SETMASK, &tset, NULL);
296 				free_defs();
297 #ifdef	DEBUG
298 				debug("/etc/ttydefs is modified, re-read it");
299 #endif
300 				read_ttydefs(NULL, FALSE);
301 				(void) sigprocmask(SIG_SETMASK, &cset, NULL);
302 			}
303 			open_device(tp);
304 			if (tp->p_fd > 0)
305 				got_carrier(tp);
306 		} else if (((tp->p_status == LOCKED) ||
307 		    (tp->p_status == SESSION) ||
308 		    (tp->p_status == UNACCESS)) &&
309 		    (tp->p_fd > 0) &&
310 		    (!((State == PM_DISABLED) &&
311 		    ((tp->p_dmsg == NULL)||(*(tp->p_dmsg) == '\0'))))) {
312 			if (check_modtime && mod_ttydefs()) {
313 				check_modtime = FALSE;
314 				(void) sigprocmask(SIG_SETMASK, NULL, &cset);
315 				tset = cset;
316 				(void) sigaddset(&tset, SIGCLD);
317 				(void) sigprocmask(SIG_SETMASK, &tset, NULL);
318 				free_defs();
319 #ifdef	DEBUG
320 				debug("/etc/ttydefs is modified, re-read it");
321 #endif
322 				read_ttydefs(NULL, FALSE);
323 				(void) sigprocmask(SIG_SETMASK, &cset, NULL);
324 			}
325 			tp->p_status = VALID;
326 			open_device(tp);
327 			if (tp->p_fd > 0)
328 				got_carrier(tp);
329 		}
330 	}
331 }
332 
333 void
334 set_softcar(pmptr)
335 struct	pmtab	*pmptr;
336 {
337 
338 	int fd, val = 0;
339 
340 #ifdef	DEBUG
341 	debug("in set_softcar");
342 #endif
343 	/*
344 	 * If soft carrier is not set one way or
345 	 * the other, leave it alone.
346 	 */
347 	if (*pmptr->p_softcar == '\0')
348 		return;
349 
350 	if (*pmptr->p_softcar == 'y')
351 		val = 1;
352 
353 	if ((fd = open(pmptr->p_device, O_RDONLY|O_NONBLOCK|O_NOCTTY)) < 0) {
354 		log("open (%s) failed: %s", pmptr->p_device, strerror(errno));
355 		return;
356 	}
357 
358 	if (ioctl(fd, TIOCSSOFTCAR, &val) < 0)
359 		log("set soft-carrier (%s) failed: %s", pmptr->p_device,
360 		    strerror(errno));
361 
362 	close(fd);
363 }
364 
365 
366 /*
367  *	open_device(pmptr)	- open the device
368  *				- check device lock
369  *				- change owner of device
370  *				- push line disciplines
371  *				- set termio
372  */
373 
374 void
375 open_device(pmptr)
376 struct	pmtab	*pmptr;
377 {
378 	int	fd, tmpfd;
379 	struct	sigaction	sigact;
380 
381 #ifdef	DEBUG
382 	debug("in open_device");
383 #endif
384 
385 	if (pmptr->p_status == GETTY) {
386 		revokedevaccess(pmptr->p_device, 0, 0, 0);
387 
388 		if ((fd = open(pmptr->p_device, O_RDWR)) == -1)
389 			fatal("open (%s) failed: %s", pmptr->p_device,
390 			    strerror(errno));
391 
392 	} else {
393 		if (check_spawnlimit(pmptr) == -1) {
394 			pmptr->p_status = NOTVALID;
395 			log("service <%s> is respawning too rapidly",
396 			    pmptr->p_tag);
397 			return;
398 		}
399 		if (pmptr->p_fd > 0) { /* file already open */
400 			fd = pmptr->p_fd;
401 			pmptr->p_fd = 0;
402 		} else if ((fd = open(pmptr->p_device, O_RDWR|O_NONBLOCK))
403 		    == -1) {
404 			log("open (%s) failed: %s", pmptr->p_device,
405 			    strerror(errno));
406 			if ((errno ==  ENODEV) || (errno == EBUSY)) {
407 				pmptr->p_status = UNACCESS;
408 				Nlocked++;
409 				if (Nlocked == 1) {
410 				    sigact.sa_flags = 0;
411 				    sigact.sa_handler = sigalarm;
412 				    (void) sigemptyset(&sigact.sa_mask);
413 				    (void) sigaction(SIGALRM, &sigact, NULL);
414 				    (void) alarm(ALARMTIME);
415 				}
416 			} else
417 				Retry = TRUE;
418 			return;
419 		}
420 		/* set close-on-exec flag */
421 		if (fcntl(fd, F_SETFD, 1) == -1)
422 			fatal("F_SETFD fcntl failed: %s", strerror(errno));
423 
424 		if (tm_checklock(fd) != 0) {
425 			pmptr->p_status = LOCKED;
426 			(void) close(fd);
427 			Nlocked++;
428 			if (Nlocked == 1) {
429 				sigact.sa_flags = 0;
430 				sigact.sa_handler = sigalarm;
431 				(void) sigemptyset(&sigact.sa_mask);
432 				(void) sigaction(SIGALRM, &sigact, NULL);
433 				(void) alarm(ALARMTIME);
434 			}
435 			return;
436 		}
437 		if (check_session(fd) != 0) {
438 			if ((Initialized) && (pmptr->p_inservice != SESSION)) {
439 				log("Warning -- active session exists on <%s>",
440 				    pmptr->p_device);
441 			} else {
442 				/*
443 				 * this may happen if a service is running
444 				 * and ttymon dies and is restarted,
445 				 * or another process is running on the
446 				 * port.
447 				 */
448 				pmptr->p_status = SESSION;
449 				pmptr->p_inservice = 0;
450 				(void) close(fd);
451 				Nlocked++;
452 				if (Nlocked == 1) {
453 					sigact.sa_flags = 0;
454 					sigact.sa_handler = sigalarm;
455 					(void) sigemptyset(&sigact.sa_mask);
456 					(void) sigaction(SIGALRM, &sigact,
457 					    NULL);
458 					(void) alarm(ALARMTIME);
459 				}
460 				return;
461 			}
462 		}
463 		pmptr->p_inservice = 0;
464 	}
465 
466 	if (pmptr->p_ttyflags & H_FLAG) {
467 		/* drop DTR */
468 		(void) hang_up_line(fd);
469 		/*
470 		 * After hang_up_line, the stream is in STRHUP state.
471 		 * We need to do another open to reinitialize streams
472 		 * then we can close one fd
473 		 */
474 		if ((tmpfd = open(pmptr->p_device, O_RDWR|O_NONBLOCK)) == -1) {
475 			log("open (%s) failed: %s", pmptr->p_device,
476 			    strerror(errno));
477 			Retry = TRUE;
478 			(void) close(fd);
479 			return;
480 		}
481 		(void) close(tmpfd);
482 	}
483 
484 #ifdef DEBUG
485 	debug("open_device (%s), fd = %d", pmptr->p_device, fd);
486 #endif
487 
488 	/* Change ownership of the tty line to root/uucp and */
489 	/* set protections to only allow root/uucp to read the line. */
490 
491 	if (pmptr->p_ttyflags & (B_FLAG|C_FLAG))
492 		(void) fchown(fd, Uucp_uid, Tty_gid);
493 	else
494 		(void) fchown(fd, ROOTUID, Tty_gid);
495 	(void) fchmod(fd, 0620);
496 
497 	if ((pmptr->p_modules != NULL)&&(*(pmptr->p_modules) != '\0')) {
498 		if (push_linedisc(fd, pmptr->p_modules, pmptr->p_device)
499 		    == -1) {
500 			Retry = TRUE;
501 			(void) close(fd);
502 			return;
503 		}
504 	}
505 
506 	if (initial_termio(fd, pmptr) == -1)  {
507 		Retry = TRUE;
508 		(void) close(fd);
509 		return;
510 	}
511 
512 	di_devperm_logout((const char *)pmptr->p_device);
513 	pmptr->p_fd = fd;
514 }
515 
516 /*
517  *	set_poll(fdp)	- put all fd's in a pollfd array
518  *			- set poll event to POLLIN and POLLMSG
519  *			- return number of fd to be polled
520  */
521 
522 static	int
523 set_poll(fdp)
524 struct pollfd *fdp;
525 {
526 	struct	pmtab	*tp;
527 	int 	nfd = 0;
528 
529 	for (tp = PMtab; tp; tp = tp->p_next) {
530 		if (tp->p_fd > 0)  {
531 			fdp->fd = tp->p_fd;
532 			fdp->events = POLLIN;
533 			fdp++;
534 			nfd++;
535 		}
536 	}
537 	return (nfd);
538 }
539 
540 /*
541  *	check_spawnlimit	- return 0 if spawnlimit is not reached
542  *				- otherwise return -1
543  */
544 static	int
545 check_spawnlimit(pmptr)
546 struct	pmtab	*pmptr;
547 {
548 	time_t	now;
549 
550 	(void) time(&now);
551 	if (pmptr->p_time == 0L)
552 		pmptr->p_time = now;
553 	if (pmptr->p_respawn >= SPAWN_LIMIT) {
554 		if ((now - pmptr->p_time) < SPAWN_INTERVAL) {
555 			pmptr->p_time = now;
556 			pmptr->p_respawn = 0;
557 			return (-1);
558 		}
559 		pmptr->p_time = now;
560 		pmptr->p_respawn = 0;
561 	}
562 	pmptr->p_respawn++;
563 	return (0);
564 }
565 
566 /*
567  * mod_ttydefs	- to check if /etc/ttydefs has been modified
568  *		- return TRUE if file modified
569  *		- otherwise, return FALSE
570  */
571 static	int
572 mod_ttydefs()
573 {
574 	struct	stat	statbuf;
575 	extern	long	Mtime;
576 	if (stat(TTYDEFS, &statbuf) == -1) {
577 		/* if stat failed, don't bother reread ttydefs */
578 		return (FALSE);
579 	}
580 	if ((long)statbuf.st_mtime != Mtime) {
581 		Mtime = (long)statbuf.st_mtime;
582 		return (TRUE);
583 	}
584 	return (FALSE);
585 }
586 
587 /*
588  *	free_defs - free the Gdef table
589  */
590 static	void
591 free_defs()
592 {
593 	int	i;
594 	struct	Gdef	*tp;
595 	tp = &Gdef[0];
596 	for (i = 0; i < Ndefs; i++, tp++) {
597 		free(tp->g_id);
598 		free(tp->g_iflags);
599 		free(tp->g_fflags);
600 		free(tp->g_nextid);
601 		tp->g_id = NULL;
602 		tp->g_iflags = NULL;
603 		tp->g_fflags = NULL;
604 		tp->g_nextid = NULL;
605 	}
606 	Ndefs = 0;
607 }
608 
609 /*
610  * struct Gdef *get_speed(ttylabel)
611  *	- search "/etc/ttydefs" for speed and term. specification
612  *	  using "ttylabel". If "ttylabel" is NULL, default
613  *	  to DEFAULT
614  * arg:	  ttylabel - label/id of speed settings.
615  */
616 
617 struct Gdef *
618 get_speed(char *ttylabel)
619 {
620 	register struct Gdef *sp;
621 	extern   struct Gdef DEFAULT;
622 
623 	if ((ttylabel != NULL) && (*ttylabel != '\0')) {
624 		if ((sp = find_def(ttylabel)) == NULL) {
625 			log("unable to find <%s> in \"%s\"", ttylabel, TTYDEFS);
626 			sp = &DEFAULT; /* use default */
627 		}
628 	} else sp = &DEFAULT; /* use default */
629 	return (sp);
630 }
631 
632 /*
633  * setup_PCpipe()	- setup the pipe between Parent and Children
634  *			- the pipe is used for a tmchild to send its
635  *			  pid to inform ttymon that it is about to
636  *			  invoke service
637  *			- the pipe also serves as a mean for tmchild
638  *			  to detect failure of ttymon
639  */
640 void
641 setup_PCpipe()
642 {
643 	int	flag = 0;
644 
645 	if (pipe(PCpipe) == -1)
646 		fatal("pipe() failed: %s", strerror(errno));
647 
648 	/* set close-on-exec flag */
649 	if (fcntl(PCpipe[0], F_SETFD, 1) == -1)
650 		fatal("F_SETFD fcntl failed: %s", strerror(errno));
651 
652 	if (fcntl(PCpipe[1], F_SETFD, 1) == -1)
653 		fatal("F_SETFD fcntl failed: %s", strerror(errno));
654 
655 	/* set O_NONBLOCK flag */
656 	if (fcntl(PCpipe[0], F_GETFL, flag) == -1)
657 		fatal("F_GETFL failed: %s", strerror(errno));
658 
659 	flag |= O_NONBLOCK;
660 	if (fcntl(PCpipe[0], F_SETFL, flag) == -1)
661 		fatal("F_SETFL failed: %s", strerror(errno));
662 
663 	/* set message discard mode */
664 	if (ioctl(PCpipe[0], I_SRDOPT, RMSGD) == -1)
665 		fatal("I_SRDOPT RMSGD failed: %s", strerror(errno));
666 
667 	/* register to receive SIGPOLL when data come */
668 	if (ioctl(PCpipe[0], I_SETSIG, S_INPUT) == -1)
669 		fatal("I_SETSIG S_INPUT failed: %s", strerror(errno));
670 
671 #ifdef 	DEBUG
672 	log("PCpipe[0]\t = %d", PCpipe[0]);
673 	log("PCpipe[1]\t = %d", PCpipe[1]);
674 #endif
675 }
676