xref: /illumos-gate/usr/src/cmd/cmd-inet/usr.bin/pppd/main.c (revision d1aea6f139360e9e7f1504facb24f8521047b15c)
1 /*
2  * main.c - Point-to-Point Protocol main module
3  *
4  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
5  * Use is subject to license terms.
6  *
7  * Permission to use, copy, modify, and distribute this software and its
8  * documentation is hereby granted, provided that the above copyright
9  * notice appears in all copies.
10  *
11  * SUN MAKES NO REPRESENTATION OR WARRANTIES ABOUT THE SUITABILITY OF
12  * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
13  * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
14  * PARTICULAR PURPOSE, OR NON-INFRINGEMENT.  SUN SHALL NOT BE LIABLE FOR
15  * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
16  * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES
17  *
18  * Copyright (c) 1989 Carnegie Mellon University.
19  * All rights reserved.
20  *
21  * Redistribution and use in source and binary forms are permitted
22  * provided that the above copyright notice and this paragraph are
23  * duplicated in all such forms and that any documentation,
24  * advertising materials, and other materials related to such
25  * distribution and use acknowledge that the software was developed
26  * by Carnegie Mellon University.  The name of the
27  * University may not be used to endorse or promote products derived
28  * from this software without specific prior written permission.
29  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
30  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
31  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
32  */
33 /*
34  * Copyright (c) 2016 by Delphix. All rights reserved.
35  */
36 
37 #define RCSID	"$Id: main.c,v 1.97 2000/04/24 02:54:16 masputra Exp $"
38 
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43 #include <signal.h>
44 #include <errno.h>
45 #include <fcntl.h>
46 #include <syslog.h>
47 #include <netdb.h>
48 #include <pwd.h>
49 #include <setjmp.h>
50 #include <sys/param.h>
51 #include <sys/types.h>
52 #include <sys/wait.h>
53 #include <sys/time.h>
54 #include <sys/resource.h>
55 #include <sys/stat.h>
56 #include <sys/socket.h>
57 #include <netinet/in.h>
58 #include <arpa/inet.h>
59 
60 #include "pppd.h"
61 #include "magic.h"
62 #include "fsm.h"
63 #include "lcp.h"
64 #include "ipcp.h"
65 #ifdef INET6
66 #include "ipv6cp.h"
67 #endif
68 #include "upap.h"
69 #include "chap.h"
70 #include "ccp.h"
71 #include "pathnames.h"
72 #include "patchlevel.h"
73 
74 #ifdef HAVE_MULTILINK
75 #include "tdb.h"
76 #endif
77 
78 #ifdef CBCP_SUPPORT
79 #include "cbcp.h"
80 #endif
81 
82 #ifdef IPX_CHANGE
83 #include "ipxcp.h"
84 #endif /* IPX_CHANGE */
85 #ifdef AT_CHANGE
86 #include "atcp.h"
87 #endif
88 
89 #if !defined(lint) && !defined(_lint)
90 static const char rcsid[] = RCSID;
91 #endif
92 
93 /* interface vars */
94 char ifname[32];		/* Interface name */
95 int ifunit = -1;		/* Interface unit number */
96 
97 char *progname;			/* Name of this program */
98 char hostname[MAXHOSTNAMELEN+1]; /* Our hostname */
99 static char pidfilename[MAXPATHLEN]; /* name of pid file */
100 static char linkpidfile[MAXPATHLEN]; /* name of linkname pid file */
101 char ppp_devnam[MAXPATHLEN];	/* name of PPP tty (maybe ttypx) */
102 static uid_t uid;		/* Our real user-id */
103 static int conn_running;	/* we have a [dis]connector running */
104 
105 int ttyfd;			/* Serial port file descriptor */
106 mode_t tty_mode = (mode_t)-1;	/* Original access permissions to tty */
107 int baud_rate;			/* Actual bits/second for serial device */
108 bool hungup;			/* terminal has been hung up */
109 bool privileged;		/* we're running as real uid root */
110 bool need_holdoff;		/* need holdoff period before restarting */
111 bool detached;			/* have detached from terminal */
112 struct stat devstat;		/* result of stat() on devnam */
113 bool prepass = 0;		/* doing prepass to find device name */
114 int devnam_fixed;		/* set while in options.ttyxx file */
115 volatile int status;		/* exit status for pppd */
116 int unsuccess;			/* # unsuccessful connection attempts */
117 int do_callback;		/* != 0 if we should do callback next */
118 int doing_callback;		/* != 0 if we are doing callback */
119 char *callback_script;		/* script for doing callback */
120 #ifdef HAVE_MULTILINK
121 TDB_CONTEXT *pppdb;		/* database for storing status etc. */
122 char db_key[32];
123 #endif
124 
125 /*
126  * For plug-in usage:
127  *
128  *	holdoff_hook - Can be used to change the demand-dial hold-off
129  *		time dynamically.  This is normally set by the
130  *		"holdoff" option, and is 30 seconds by default.
131  *
132  *	new_phase_hook - This is called for each change in the PPP
133  *		phase (per RFC 1661).  This can be used to log
134  *		progress.
135  *
136  *	check_options_hook - This is called before doing sys_init()
137  *		and allows the plugin to verify the selected options.
138  *
139  *	updown_script_hook - This is called with the proposed
140  *		command-line arguments for any of the
141  *		/etc/ppp/{ip,ipv6,ipx,auth}-{up,down} scripts before
142  *		fork/exec.  It can be used to add or change arguments.
143  *
144  *	device_pipe_hook - If this is set, then an extra fd (3) is
145  *		passed to the connect/disconnect script.  This extra
146  *		fd is the write side of a pipe, and the read side is
147  *		passed to this routine.  This can be used to pass
148  *		arbitrary data from the script back to pppd.
149  */
150 int (*holdoff_hook) __P((void)) = NULL;
151 int (*new_phase_hook) __P((int new, int old)) = NULL;
152 int (*check_options_hook) __P((uid_t uid)) = NULL;
153 int (*updown_script_hook) __P((const char ***argsp)) = NULL;
154 void (*device_pipe_hook) __P((int pipefd)) = NULL;
155 
156 static int fd_ppp = -1;		/* fd for talking PPP */
157 static int fd_loop;		/* fd for getting demand-dial packets */
158 static int pty_master;		/* fd for master side of pty */
159 int pty_slave = -1;		/* fd for slave side of pty */
160 static int real_ttyfd;		/* fd for actual serial port (not pty) */
161 
162 int phase;			/* where the link is at */
163 int kill_link;
164 int open_ccp_flag;
165 
166 static int waiting;		/* for input from peer or timer expiration */
167 static sigjmp_buf sigjmp;
168 
169 char **script_env;		/* Env. variable values for scripts */
170 int s_env_nalloc;		/* # words avail at script_env */
171 
172 u_char outpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for outgoing packet */
173 u_char inpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for incoming packet */
174 u_char nak_buffer[PPP_MRU];	/* where we construct a nak packet */
175 
176 static int n_children;		/* # child processes still running */
177 static bool got_sigchld;	/* set if we have received a SIGCHLD */
178 static sigset_t main_sigmask;	/* signals blocked while dispatching */
179 
180 static bool locked;		/* lock() has succeeded */
181 static bool privopen;		/* don't lock, open device as root */
182 
183 char *no_ppp_msg = "Sorry - this system lacks PPP kernel support\n";
184 
185 GIDSET_TYPE groups[NGROUPS_MAX];/* groups the user is in */
186 int ngroups;			/* How many groups valid in groups */
187 
188 static struct timeval start_time; /* Time when link was started. */
189 
190 struct pppd_stats link_stats;
191 int link_connect_time;
192 bool link_stats_valid;
193 
194 static pid_t charshunt_pid;	/* Process ID for charshunt */
195 
196 extern option_t general_options[];
197 extern option_t auth_options[];
198 
199 /*
200  * We maintain a list of child process pids and
201  * functions to call when they exit.
202  */
203 struct subprocess {
204     pid_t	pid;
205     char	*prog;
206     void	(*done) __P((void *, int));
207     void	*arg;
208     struct subprocess *next;
209 };
210 
211 static struct subprocess *children;
212 
213 /* Prototypes for procedures local to this file. */
214 
215 static void setup_signals __P((void));
216 static void create_pidfile __P((void));
217 static void create_linkpidfile __P((void));
218 static void cleanup __P((void));
219 static void close_tty __P((void));
220 static void get_input __P((void));
221 static void calltimeout __P((void));
222 static struct timeval *timeleft __P((struct timeval *));
223 static void kill_my_pg __P((int));
224 static void hup __P((int));
225 static void term __P((int));
226 static void chld __P((int));
227 static void toggle_debug __P((int));
228 static void open_ccp __P((int));
229 static void bad_signal __P((int));
230 static void holdoff_end __P((void *));
231 static int device_script __P((char *, int, int, int, char *));
232 static int reap_kids __P((int waitfor));
233 static void record_child __P((pid_t, char *, void (*) (void *, int), void *));
234 static int open_socket __P((char *));
235 static int start_charshunt __P((int, int));
236 static void charshunt_done __P((void *, int));
237 static void charshunt __P((int, int, char *));
238 static int record_write __P((FILE *, int code, u_char *buf, int nb,
239     struct timeval *));
240 static void final_reap __P((void));
241 
242 #ifdef HAVE_MULTILINK
243 static void update_db_entry __P((void));
244 static void add_db_key __P((const char *));
245 static void delete_db_key __P((const char *));
246 static void cleanup_db __P((void));
247 #endif
248 
249 int main __P((int, char *[]));
250 
251 #ifdef ultrix
252 #undef	O_NONBLOCK
253 #define	O_NONBLOCK	O_NDELAY
254 #endif
255 
256 #ifdef ULTRIX
257 #define setlogmask(x)	0
258 #endif
259 
260 /* Backward compatibility for Linux */
261 #ifndef RECMARK_TIMESTART
262 #define	RECMARK_STARTSEND	1
263 #define	RECMARK_STARTRECV	2
264 #define	RECMARK_ENDSEND		3
265 #define	RECMARK_ENDRECV		4
266 #define	RECMARK_TIMEDELTA32	5
267 #define	RECMARK_TIMEDELTA8	6
268 #define	RECMARK_TIMESTART	7
269 #endif
270 
271 /*
272  * PPP Data Link Layer "protocol" table.
273  * One entry per supported protocol.
274  * The last entry must be NULL.
275  */
276 struct protent *protocols[] = {
277     &lcp_protent,
278     &pap_protent,
279     &chap_protent,
280 #ifdef CBCP_SUPPORT
281     &cbcp_protent,
282 #endif
283     &ipcp_protent,
284 #ifdef INET6
285     &ipv6cp_protent,
286 #endif
287     &ccp_protent,
288 #ifdef IPX_CHANGE
289     &ipxcp_protent,
290 #endif
291 #ifdef AT_CHANGE
292     &atcp_protent,
293 #endif
294     NULL
295 };
296 
297 int
298 main(argc, argv)
299     int argc;
300     char *argv[];
301 {
302     int i, fdflags, t;
303     char *p, *connector;
304     struct passwd *pw;
305     struct timeval timo;
306     struct protent *protp;
307     struct stat statbuf;
308     char numbuf[16];
309 
310     ifname[0] = '\0';
311     new_phase(PHASE_INITIALIZE);
312 
313     /*
314      * Ensure that fds 0, 1, 2 are open, to /dev/null if nowhere else.
315      * This way we can close 0, 1, 2 in detach() without clobbering
316      * a fd that we are using.
317      */
318     if ((i = open(_PATH_DEVNULL, O_RDWR)) >= 0) {
319 	while (0 <= i && i <= 2)
320 	    i = dup(i);
321 	if (i >= 0)
322 	    (void) close(i);
323     }
324 
325     script_env = NULL;
326 
327     /* Initialize syslog facilities */
328     reopen_log();
329 
330     if (gethostname(hostname, MAXHOSTNAMELEN+1) < 0 ) {
331 	option_error("Couldn't get hostname: %m");
332 	exit(1);
333     }
334     hostname[MAXHOSTNAMELEN] = '\0';
335 
336     /* make sure we don't create world or group writable files. */
337     (void) umask(umask(0777) | 022);
338 
339     uid = getuid();
340     privileged = (uid == 0);
341     (void) slprintf(numbuf, sizeof(numbuf), "%d", uid);
342     script_setenv("ORIG_UID", numbuf, 0);
343 
344     ngroups = getgroups(NGROUPS_MAX, groups);
345 
346     /*
347      * Initialize magic number generator now so that protocols may
348      * use magic numbers in initialization.
349      */
350     magic_init();
351 
352     progname = *argv;
353     prepass = 0;
354     /*
355      * Initialize to the standard option set, then parse, in order, the
356      * system options file, the user's options file, the tty's options file,
357      * and the command line arguments.  At last, install the options declared
358      * by each protocol into the extra_option list.
359      */
360     for (i = 0; (protp = protocols[i]) != NULL; ++i) {
361         (*protp->init)(0);
362 	if (protp->options != NULL) {
363 	    add_options(protp->options);
364 	}
365     }
366 
367     /*
368      * Install "generic" options into the extra_options list.
369      */
370     add_options(auth_options);
371     add_options(general_options);
372 
373     /* Install any system-specific options (or remove unusable ones) */
374     sys_options();
375 
376     if (!options_from_file(_PATH_SYSOPTIONS, !privileged, 0, 1)
377 	|| !options_from_user())
378 	exit(EXIT_OPTION_ERROR);
379 
380     /* scan command line and options files to find device name */
381     prepass = 1;
382     (void) parse_args(argc-1, argv+1);
383     prepass = 0;
384 
385     /*
386      * Work out the device name, if it hasn't already been specified.
387      */
388     using_pty = notty || ptycommand != NULL || pty_socket != NULL;
389     if (!using_pty && default_device && !direct_tty) {
390 	char *p;
391 
392 	if (!isatty(0) || (p = ttyname(0)) == NULL) {
393 	    option_error("no device specified and stdin is not a tty");
394 	    exit(EXIT_OPTION_ERROR);
395 	}
396 	(void) strlcpy(devnam, p, sizeof(devnam));
397 	if (stat(devnam, &devstat) < 0)
398 	    fatal("Couldn't stat default device %s: %m", devnam);
399     }
400 
401     /*
402      * Parse the tty options file and the command line.
403      * The per-tty options file should not change
404      * ptycommand, pty_socket, notty or devnam.
405      */
406     devnam_fixed = 1;
407     if (!using_pty && !direct_tty) {
408 	if (!options_for_tty())
409 	    exit(EXIT_OPTION_ERROR);
410     }
411 
412     devnam_fixed = 0;
413     if (!parse_args(argc-1, argv+1))
414 	exit(EXIT_OPTION_ERROR);
415 
416     /*
417      * Check that we are running as root.
418      */
419     if (geteuid() != 0) {
420 	option_error("must be root to run %s, since it is not setuid-root",
421 		     argv[0]);
422 	exit(EXIT_NOT_ROOT);
423     }
424 
425     if (!ppp_available()) {
426 	option_error(no_ppp_msg);
427 	exit(EXIT_NO_KERNEL_SUPPORT);
428     }
429 
430     /*
431      * Check that the options given are valid and consistent.
432      */
433     if (!sys_check_options())
434 	exit(EXIT_OPTION_ERROR);
435     auth_check_options();
436 #ifdef HAVE_MULTILINK
437     mp_check_options();
438 #endif
439     for (i = 0; (protp = protocols[i]) != NULL; ++i)
440 	if (protp->enabled_flag && protp->check_options != NULL)
441 	    (*protp->check_options)();
442     if (demand && (connect_script == NULL)) {
443 	option_error("connect script is required for demand-dialling\n");
444 	exit(EXIT_OPTION_ERROR);
445     }
446     if (updetach && (nodetach || demand)) {
447 	option_error("updetach cannot be used with %s",
448 	    nodetach ? "nodetach" : "demand");
449 	exit(EXIT_OPTION_ERROR);
450     }
451     /* default holdoff to 0 if no connect script has been given */
452     if ((connect_script == NULL) && !holdoff_specified)
453 	holdoff = 0;
454 
455     if (using_pty || direct_tty) {
456 	if (!default_device) {
457 	    option_error("%s option precludes specifying device name",
458 			 notty? "notty": "pty");
459 	    exit(EXIT_OPTION_ERROR);
460 	}
461 	if (ptycommand != NULL && (notty || direct_tty)) {
462 	    option_error("pty option is incompatible with notty option");
463 	    exit(EXIT_OPTION_ERROR);
464 	}
465 	if (pty_socket != NULL && (ptycommand != NULL || notty ||
466 	    direct_tty)) {
467 	    option_error("socket option is incompatible with pty and notty");
468 	    exit(EXIT_OPTION_ERROR);
469 	}
470 	default_device = notty || direct_tty;
471 	lockflag = 0;
472 	modem = 0;
473 	if (default_device && log_to_fd <= 1)
474 	    log_to_fd = -1;
475     } else {
476 	/*
477 	 * If the user has specified a device which is the same as
478 	 * the one on stdin, pretend they didn't specify any.
479 	 * If the device is already open read/write on stdin,
480 	 * we assume we don't need to lock it, and we can open it as root.
481 	 */
482 	if (fstat(0, &statbuf) >= 0 && S_ISCHR(statbuf.st_mode)
483 	    && statbuf.st_rdev == devstat.st_rdev) {
484 	    default_device = 1;
485 	    fdflags = fcntl(0, F_GETFL);
486 	    if (fdflags != -1 && (fdflags & O_ACCMODE) == O_RDWR)
487 		privopen = 1;
488 	}
489     }
490     if (default_device)
491 	nodetach = 1;
492 
493     /*
494      * Don't send log messages to the serial port, it tends to
495      * confuse the peer. :-)
496      */
497     if (log_to_fd >= 0 && fstat(log_to_fd, &statbuf) >= 0
498 	&& S_ISCHR(statbuf.st_mode) && statbuf.st_rdev == devstat.st_rdev)
499 	log_to_fd = -1;
500     early_log = 0;
501 
502     if (debug)
503 	(void) setlogmask(LOG_UPTO(LOG_DEBUG));
504 
505     /*
506      * Initialize system-dependent stuff.
507      */
508     if (check_options_hook != NULL &&
509 	(*check_options_hook)(uid) == -1) {
510 	exit(EXIT_OPTION_ERROR);
511     }
512     sys_init(!devnam_info.priv && !privopen);
513 
514 #ifdef HAVE_MULTILINK
515     pppdb = tdb_open(_PATH_PPPDB, 0, 0, O_RDWR|O_CREAT, 0644);
516     if (pppdb != NULL) {
517 	(void) slprintf(db_key, sizeof(db_key), "pppd%d", getpid());
518 	update_db_entry();
519     } else {
520 	warn("Warning: couldn't open ppp database %s", _PATH_PPPDB);
521 	if (multilink) {
522 	    warn("Warning: disabling multilink");
523 	    multilink = 0;
524 	}
525     }
526 #endif
527 
528     /*
529      * Detach ourselves from the terminal, if required, and identify
530      * who is running us.  Printing to stderr stops here unless
531      * nodetach or updetach is set.
532      */
533     if (!nodetach && !updetach)
534 	detach();
535     p = getlogin();
536     if (p == NULL) {
537 	pw = getpwuid(uid);
538 	if (pw != NULL && pw->pw_name != NULL)
539 	    p = pw->pw_name;
540 	else
541 	    p = "(unknown)";
542     }
543     syslog(LOG_NOTICE, "pppd %s.%d%s started by %s, uid %d",
544 	   VERSION, PATCHLEVEL, IMPLEMENTATION, p, uid);
545     script_setenv("PPPLOGNAME", p, 0);
546 
547     if (devnam[0] != '\0')
548 	script_setenv("DEVICE", devnam, 1);
549     (void) slprintf(numbuf, sizeof(numbuf), "%d", getpid());
550     script_setenv("PPPD_PID", numbuf, 1);
551 
552     setup_signals();
553 
554     waiting = 0;
555 
556     create_linkpidfile();
557 
558     /*
559      * If we're doing dial-on-demand, set up the interface now.
560      */
561     if (demand) {
562 	/*
563 	 * Open the loopback channel and set it up to be the ppp interface.
564 	 */
565 #ifdef HAVE_MULTILINK
566 	(void) tdb_writelock(pppdb);
567 #endif
568 	set_ifunit(1);
569 	fd_loop = open_ppp_loopback();
570 #ifdef HAVE_MULTILINK
571 	(void) tdb_writeunlock(pppdb);
572 #endif
573 
574 	/*
575 	 * Configure the interface and mark it up, etc.
576 	 */
577 	demand_conf();
578     }
579 
580     new_phase(PHASE_INITIALIZED);
581     do_callback = 0;
582     for (;;) {
583 
584 	need_holdoff = 1;
585 	ttyfd = -1;
586 	real_ttyfd = -1;
587 	status = EXIT_OK;
588 	++unsuccess;
589 	doing_callback = do_callback;
590 	do_callback = 0;
591 
592 	if (demand && !doing_callback) {
593 	    /*
594 	     * Don't do anything until we see some activity.
595 	     */
596 	    kill_link = 0;
597 	    new_phase(PHASE_DORMANT);
598 	    demand_unblock();
599 	    add_fd(fd_loop);
600 	    for (;;) {
601 		if (sigsetjmp(sigjmp, 1) == 0) {
602 		    (void) sigprocmask(SIG_BLOCK, &main_sigmask, NULL);
603 		    if (kill_link || got_sigchld) {
604 			(void) sigprocmask(SIG_UNBLOCK, &main_sigmask, NULL);
605 		    } else {
606 			waiting = 1;
607 			(void) sigprocmask(SIG_UNBLOCK, &main_sigmask, NULL);
608 			wait_input(timeleft(&timo));
609 		    }
610 		}
611 		waiting = 0;
612 		calltimeout();
613 		if (kill_link) {
614 		    if (!persist)
615 			break;
616 		    kill_link = 0;
617 		}
618 		if (get_loop_output())
619 		    break;
620 		if (got_sigchld)
621 		    (void) reap_kids(0);
622 	    }
623 	    remove_fd(fd_loop);
624 	    if (kill_link && !persist)
625 		break;
626 
627 	    /*
628 	     * Now we want to bring up the link.
629 	     */
630 	    demand_block();
631 	    info("Starting link");
632 	}
633 
634 	new_phase(doing_callback ? PHASE_CALLINGBACK : PHASE_SERIALCONN);
635 
636 	/*
637 	 * Get a pty master/slave pair if the pty, notty, socket,
638 	 * or record options were specified.
639 	 */
640 	(void) strlcpy(ppp_devnam, devnam, sizeof(ppp_devnam));
641 	pty_master = -1;
642 	pty_slave = -1;
643 	if (using_pty || record_file != NULL) {
644 	    if (!get_pty(&pty_master, &pty_slave, ppp_devnam, uid)) {
645 		error("Couldn't allocate pseudo-tty");
646 		status = EXIT_FATAL_ERROR;
647 		goto fail;
648 	    }
649 	    set_up_tty(pty_slave, 1);
650 	}
651 
652 	/*
653 	 * Lock the device if we've been asked to.
654 	 */
655 	status = EXIT_LOCK_FAILED;
656 	if (lockflag && !privopen && !direct_tty) {
657 	    if (lock(devnam) < 0)
658 		goto fail;
659 	    locked = 1;
660 	}
661 
662 	/*
663 	 * Open the serial device and set it up to be the ppp interface.
664 	 * First we open it in non-blocking mode so we can set the
665 	 * various termios flags appropriately.  If we aren't dialling
666 	 * out and we want to use the modem lines, we reopen it later
667 	 * in order to wait for the carrier detect signal from the modem.
668 	 */
669 	hungup = 0;
670 	kill_link = 0;
671 	connector = doing_callback? callback_script: connect_script;
672 	if (direct_tty) {
673 	    ttyfd = 0;
674 	} else if (devnam[0] != '\0') {
675 	    for (;;) {
676 		/* If the user specified the device name, become the
677 		   user before opening it. */
678 		int err;
679 		if (!devnam_info.priv && !privopen)
680 		    (void) seteuid(uid);
681 		if ((ttyfd = sys_extra_fd()) < 0)
682 		    ttyfd = open(devnam, O_NONBLOCK | O_RDWR);
683 		err = errno;
684 		if (!devnam_info.priv && !privopen)
685 		    (void) seteuid(0);
686 		if (ttyfd >= 0)
687 		    break;
688 		errno = err;
689 		if (err != EINTR) {
690 		    error("Failed to open %s: %m", devnam);
691 		    status = EXIT_OPEN_FAILED;
692 		}
693 		if (!persist || err != EINTR)
694 		    goto fail;
695 	    }
696 	    if ((fdflags = fcntl(ttyfd, F_GETFL)) == -1
697 		|| fcntl(ttyfd, F_SETFL, fdflags & ~O_NONBLOCK) < 0)
698 		warn("Couldn't reset non-blocking mode on device: %m");
699 
700 	    /*
701 	     * Do the equivalent of `mesg n' to stop broadcast messages.
702 	     */
703 	    if (fstat(ttyfd, &statbuf) < 0
704 		|| fchmod(ttyfd, statbuf.st_mode & ~(S_IWGRP | S_IWOTH)) < 0) {
705 		warn("Couldn't restrict write permissions to %s: %m", devnam);
706 	    } else
707 		tty_mode = statbuf.st_mode;
708 
709 	    /*
710 	     * Set line speed, flow control, etc.
711 	     * If we have a non-null connection or initializer script,
712 	     * on most systems we set CLOCAL for now so that we can talk
713 	     * to the modem before carrier comes up.  But this has the
714 	     * side effect that we might miss it if CD drops before we
715 	     * get to clear CLOCAL below.  On systems where we can talk
716 	     * successfully to the modem with CLOCAL clear and CD down,
717 	     * we could clear CLOCAL at this point.
718 	     */
719 	    set_up_tty(ttyfd, ((connector != NULL && connector[0] != '\0')
720 			       || initializer != NULL));
721 	    real_ttyfd = ttyfd;
722 	}
723 
724 	/*
725 	 * If the pty, socket, notty and/or record option was specified,
726 	 * start up the character shunt now.
727 	 */
728 	status = EXIT_PTYCMD_FAILED;
729 	if (ptycommand != NULL) {
730 	    if (record_file != NULL) {
731 		int ipipe[2], opipe[2], ok;
732 
733 		if (pipe(ipipe) < 0 || pipe(opipe) < 0)
734 		    fatal("Couldn't create pipes for record option: %m");
735 		dbglog("starting charshunt for pty option");
736 		ok = device_script(ptycommand, opipe[0], ipipe[1], 1,
737 		    "record") == 0 && start_charshunt(ipipe[0], opipe[1]);
738 		(void) close(ipipe[0]);
739 		(void) close(ipipe[1]);
740 		(void) close(opipe[0]);
741 		(void) close(opipe[1]);
742 		if (!ok)
743 		    goto fail;
744 	    } else {
745 		if (device_script(ptycommand, pty_master, pty_master, 1,
746 		    "pty") < 0)
747 		    goto fail;
748 		ttyfd = pty_slave;
749 		(void) close(pty_master);
750 		pty_master = -1;
751 	    }
752 	} else if (pty_socket != NULL) {
753 	    int fd = open_socket(pty_socket);
754 	    if (fd < 0)
755 		goto fail;
756 	    dbglog("starting charshunt for socket option");
757 	    if (!start_charshunt(fd, fd))
758 		goto fail;
759 	} else if (notty) {
760 	    dbglog("starting charshunt for notty option");
761 	    if (!start_charshunt(0, 1))
762 		goto fail;
763 	} else if (record_file != NULL) {
764 	    dbglog("starting charshunt for record option");
765 	    if (!start_charshunt(ttyfd, ttyfd))
766 		goto fail;
767 	}
768 
769 	/* run connection script */
770 	if (((connector != NULL) && (connector[0] != '\0')) || initializer) {
771 	    if (real_ttyfd != -1) {
772 		/* XXX do this if doing_callback == CALLBACK_DIALIN? */
773 		if (!default_device && modem && !direct_tty) {
774 		    setdtr(real_ttyfd, 0);	/* in case modem is off hook */
775 		    (void) sleep(1);
776 		    setdtr(real_ttyfd, 1);
777 		}
778 	    }
779 
780 	    if ((initializer != NULL) && (initializer[0] != '\0')) {
781 		if (device_script(initializer, ttyfd, ttyfd, 0, "init") < 0) {
782 		    error("Initializer script failed");
783 		    status = EXIT_INIT_FAILED;
784 		    goto fail;
785 		}
786 		if (kill_link)
787 		    goto disconnect;
788 
789 		info("Serial port initialized.");
790 	    }
791 
792 	    if ((connector != NULL) && (connector[0] != '\0')) {
793 		if (device_script(connector, ttyfd, ttyfd, 0, "connect") < 0) {
794 		    error("Connect script failed");
795 		    status = EXIT_CONNECT_FAILED;
796 		    goto fail;
797 		}
798 		if (kill_link)
799 		    goto disconnect;
800 
801 		info("Serial connection established.");
802 	    }
803 
804 	    /*
805 	     * Clear CLOCAL if modem option -- we now have carrier
806 	     * established, and we should respect loss of carrier.
807 	     */
808 	    if (real_ttyfd != -1)
809 		set_up_tty(real_ttyfd, 0);
810 
811 	    if (doing_callback == CALLBACK_DIALIN)
812 		connector = NULL;
813 	}
814 
815 	/* reopen tty if necessary to wait for carrier */
816 	if (connector == NULL && modem && devnam[0] != '\0' && !direct_tty) {
817 	    for (;;) {
818 		if ((i = open(devnam, O_RDWR)) >= 0)
819 		    break;
820 		if (errno != EINTR) {
821 		    error("Failed to reopen %s: %m", devnam);
822 		    status = EXIT_OPEN_FAILED;
823 		}
824 		if (!persist || errno != EINTR || hungup || kill_link)
825 		    goto fail;
826 	    }
827 	    (void) close(i);
828 	}
829 
830 	(void) slprintf(numbuf, sizeof(numbuf), "%d", baud_rate);
831 	script_setenv("SPEED", numbuf, 0);
832 
833 	/* run welcome script, if any */
834 	if ((welcomer != NULL) && (welcomer[0] != '\0')) {
835 	    if (device_script(welcomer, ttyfd, ttyfd, 0, "welcome") < 0)
836 		warn("Welcome script failed");
837 	}
838 
839 	/* set up the serial device as a ppp interface */
840 #ifdef HAVE_MULTILINK
841 	(void) tdb_writelock(pppdb);
842 #endif
843 	fd_ppp = establish_ppp(ttyfd);
844 	if (fd_ppp < 0) {
845 #ifdef HAVE_MULTILINK
846 	    (void) tdb_writeunlock(pppdb);
847 #endif
848 	    status = EXIT_FATAL_ERROR;
849 	    goto disconnect;
850 	}
851 
852 	if (!demand && ifunit >= 0)
853 	    set_ifunit(1);
854 #ifdef HAVE_MULTILINK
855 	(void) tdb_writeunlock(pppdb);
856 #endif
857 
858 	/*
859 	 * Start opening the connection and wait for
860 	 * incoming events (reply, timeout, etc.).
861 	 */
862 	notice("Connect: %s <--> %s", ifname, ppp_devnam);
863 	(void) gettimeofday(&start_time, NULL);
864 	link_stats_valid = 0;
865 	script_unsetenv("CONNECT_TIME");
866 	script_unsetenv("BYTES_SENT");
867 	script_unsetenv("BYTES_RCVD");
868 	lcp_lowerup(0);
869 
870 	/* Mostly for accounting purposes */
871 	new_phase(PHASE_CONNECTED);
872 
873 	/*
874 	 * If we are initiating this connection, wait for a short
875 	 * time for something from the peer.  This can avoid bouncing
876 	 * our packets off its tty before it has set up the tty.
877 	 */
878 	add_fd(fd_ppp);
879 	if (connect_delay != 0 && (connector != NULL || ptycommand != NULL)) {
880 	    struct timeval t;
881 	    t.tv_sec = connect_delay / 1000;
882 	    t.tv_usec = connect_delay % 1000;
883 	    wait_input(&t);
884 	}
885 
886 	lcp_open(0);		/* Start protocol */
887 	open_ccp_flag = 0;
888 	status = EXIT_NEGOTIATION_FAILED;
889 	new_phase(PHASE_ESTABLISH);
890 	while (phase != PHASE_DEAD) {
891 	    if (sigsetjmp(sigjmp, 1) == 0) {
892 		(void) sigprocmask(SIG_BLOCK, &main_sigmask, NULL);
893 		if (kill_link || open_ccp_flag || got_sigchld) {
894 		    (void) sigprocmask(SIG_UNBLOCK, &main_sigmask, NULL);
895 		} else {
896 		    waiting = 1;
897 		    (void) sigprocmask(SIG_UNBLOCK, &main_sigmask, NULL);
898 		    wait_input(timeleft(&timo));
899 		}
900 	    }
901 	    waiting = 0;
902 	    calltimeout();
903 	    get_input();
904 	    if (kill_link) {
905 		lcp_close(0, "User request");
906 		kill_link = 0;
907 	    }
908 	    if (open_ccp_flag) {
909 		if (phase == PHASE_NETWORK || phase == PHASE_RUNNING) {
910 		    /* Uncloak ourselves. */
911 		    ccp_fsm[0].flags &= ~OPT_SILENT;
912 		    (*ccp_protent.open)(0);
913 		}
914 		open_ccp_flag = 0;
915 	    }
916 	    if (got_sigchld)
917 		(void) reap_kids(0);	/* Don't leave dead kids lying around */
918 	}
919 
920 	/*
921 	 * Print connect time and statistics.
922 	 */
923 	if (link_stats_valid) {
924 	    int t = (link_connect_time + 5) / 6;    /* 1/10ths of minutes */
925 	    info("Connect time %d.%d minutes.", t/10, t%10);
926 	    info("Sent %" PPP_COUNTER_F " bytes (%" PPP_COUNTER_F
927 		" packets), received %" PPP_COUNTER_F " bytes (%" PPP_COUNTER_F
928 		" packets).",
929 		 link_stats.bytes_out, link_stats.pkts_out,
930 		 link_stats.bytes_in, link_stats.pkts_in);
931 	}
932 
933 	/*
934 	 * Delete pid file before disestablishing ppp.  Otherwise it
935 	 * can happen that another pppd gets the same unit and then
936 	 * we delete its pid file.
937 	 */
938 	if (!demand) {
939 	    if (pidfilename[0] != '\0'
940 		&& unlink(pidfilename) < 0 && errno != ENOENT)
941 		warn("unable to delete pid file %s: %m", pidfilename);
942 	    pidfilename[0] = '\0';
943 	}
944 
945 	/*
946 	 * If we may want to bring the link up again, transfer
947 	 * the ppp unit back to the loopback.  Set the
948 	 * real serial device back to its normal mode of operation.
949 	 */
950 	remove_fd(fd_ppp);
951 	clean_check();
952 	if (demand)
953 	    restore_loop();
954 	disestablish_ppp(ttyfd);
955 	fd_ppp = -1;
956 	if (!hungup)
957 	    lcp_lowerdown(0);
958 	if (!demand)
959 	    script_unsetenv("IFNAME");
960 
961 	/*
962 	 * Run disconnector script, if requested.
963 	 * XXX we may not be able to do this if the line has hung up!
964 	 */
965     disconnect:
966 	if ((disconnect_script != NULL) && (disconnect_script[0] != '\0') &&
967 	    !hungup) {
968 	    new_phase(PHASE_DISCONNECT);
969 	    if (real_ttyfd >= 0)
970 		set_up_tty(real_ttyfd, 1);
971 	    if (device_script(disconnect_script, ttyfd, ttyfd, 0,
972 		"disconnect") < 0) {
973 		warn("disconnect script failed");
974 	    } else {
975 		info("Serial link disconnected.");
976 	    }
977 	}
978 
979     fail:
980 	if (pty_master >= 0)
981 	    (void) close(pty_master);
982 	if (pty_slave >= 0) {
983 	    (void) close(pty_slave);
984 	    pty_slave = -1;
985 	}
986 	if (real_ttyfd >= 0)
987 	    close_tty();
988 	if (locked) {
989 	    locked = 0;
990 	    unlock();
991 	}
992 
993 	if (!demand) {
994 	    if (pidfilename[0] != '\0'
995 		&& unlink(pidfilename) < 0 && errno != ENOENT)
996 		warn("unable to delete pid file %s: %m", pidfilename);
997 	    pidfilename[0] = '\0';
998 	}
999 
1000 	if (!persist || (maxfail > 0 && unsuccess >= maxfail))
1001 	    break;
1002 
1003 	kill_link = 0;
1004 	if (demand)
1005 	    demand_discard();
1006 	t = need_holdoff? holdoff: 0;
1007 	if (holdoff_hook != NULL)
1008 	    t = (*holdoff_hook)();
1009 	if (t > 0) {
1010 	    new_phase(PHASE_HOLDOFF);
1011 	    TIMEOUT(holdoff_end, NULL, t);
1012 	    do {
1013 		if (sigsetjmp(sigjmp, 1) == 0) {
1014 		    (void) sigprocmask(SIG_BLOCK, &main_sigmask, NULL);
1015 		    if (kill_link || got_sigchld) {
1016 			(void) sigprocmask(SIG_UNBLOCK, &main_sigmask, NULL);
1017 		    } else {
1018 			waiting = 1;
1019 			(void) sigprocmask(SIG_UNBLOCK, &main_sigmask, NULL);
1020 			wait_input(timeleft(&timo));
1021 		    }
1022 		}
1023 		waiting = 0;
1024 		calltimeout();
1025 		if (kill_link) {
1026 		    kill_link = 0;
1027 		    new_phase(PHASE_DORMANT); /* allow signal to end holdoff */
1028 		}
1029 		if (got_sigchld)
1030 		    (void) reap_kids(0);
1031 	    } while (phase == PHASE_HOLDOFF);
1032 	    if (!persist)
1033 		break;
1034 	}
1035     }
1036 
1037     /* Wait for scripts to finish */
1038     final_reap();
1039 
1040     die(status);
1041     return (0);
1042 }
1043 
1044 /*
1045  * setup_signals - initialize signal handling.
1046  */
1047 static void
1048 setup_signals()
1049 {
1050     struct sigaction sa;
1051 
1052     /*
1053      * Compute mask of all interesting signals and install signal handlers
1054      * for each.  Only one signal handler may be active at a time.  Therefore,
1055      * all other signals should be masked when any handler is executing.
1056      */
1057     (void) sigemptyset(&main_sigmask);
1058     (void) sigaddset(&main_sigmask, SIGHUP);
1059     (void) sigaddset(&main_sigmask, SIGINT);
1060     (void) sigaddset(&main_sigmask, SIGTERM);
1061     (void) sigaddset(&main_sigmask, SIGCHLD);
1062     (void) sigaddset(&main_sigmask, SIGUSR2);
1063 
1064 #define SIGNAL(s, handler)	if (1) { \
1065 	sa.sa_handler = handler; \
1066 	if (sigaction(s, &sa, NULL) < 0) \
1067 	    fatal("Couldn't establish signal handler (%d): %m", s); \
1068     } else ((void)0)
1069 
1070     sa.sa_mask = main_sigmask;
1071     sa.sa_flags = 0;
1072 /*CONSTANTCONDITION*/ SIGNAL(SIGHUP, hup);		/* Hangup */
1073 /*CONSTANTCONDITION*/ SIGNAL(SIGINT, term);		/* Interrupt */
1074 /*CONSTANTCONDITION*/ SIGNAL(SIGTERM, term);		/* Terminate */
1075 /*CONSTANTCONDITION*/ SIGNAL(SIGCHLD, chld);
1076 
1077 /*CONSTANTCONDITION*/ SIGNAL(SIGUSR1, toggle_debug);	/* Toggle debug flag */
1078 /*CONSTANTCONDITION*/ SIGNAL(SIGUSR2, open_ccp);	/* Reopen CCP */
1079 
1080     /*
1081      * Install a handler for other signals which would otherwise
1082      * cause pppd to exit without cleaning up.
1083      */
1084 /*CONSTANTCONDITION*/ SIGNAL(SIGALRM, bad_signal);
1085 /*CONSTANTCONDITION*/ SIGNAL(SIGQUIT, bad_signal);
1086 
1087 /* Do not hook any of these signals on Solaris; allow core dump instead */
1088 #ifndef SOL2
1089 /*CONSTANTCONDITION*/ SIGNAL(SIGABRT, bad_signal);
1090 /*CONSTANTCONDITION*/ SIGNAL(SIGFPE, bad_signal);
1091 /*CONSTANTCONDITION*/ SIGNAL(SIGILL, bad_signal);
1092 #ifndef DEBUG
1093 /*CONSTANTCONDITION*/ SIGNAL(SIGSEGV, bad_signal);
1094 #endif
1095 #ifdef SIGBUS
1096 /*CONSTANTCONDITION*/ SIGNAL(SIGBUS, bad_signal);
1097 #endif
1098 #ifdef SIGEMT
1099 /*CONSTANTCONDITION*/ SIGNAL(SIGEMT, bad_signal);
1100 #endif
1101 #ifdef SIGPOLL
1102 /*CONSTANTCONDITION*/ SIGNAL(SIGPOLL, bad_signal);
1103 #endif
1104 #ifdef SIGPROF
1105 /*CONSTANTCONDITION*/ SIGNAL(SIGPROF, bad_signal);
1106 #endif
1107 #ifdef SIGSYS
1108 /*CONSTANTCONDITION*/ SIGNAL(SIGSYS, bad_signal);
1109 #endif
1110 #ifdef SIGTRAP
1111 /*CONSTANTCONDITION*/ SIGNAL(SIGTRAP, bad_signal);
1112 #endif
1113 #ifdef SIGVTALRM
1114 /*CONSTANTCONDITION*/ SIGNAL(SIGVTALRM, bad_signal);
1115 #endif
1116 #ifdef SIGXCPU
1117 /*CONSTANTCONDITION*/ SIGNAL(SIGXCPU, bad_signal);
1118 #endif
1119 #ifdef SIGXFSZ
1120 /*CONSTANTCONDITION*/ SIGNAL(SIGXFSZ, bad_signal);
1121 #endif
1122 #endif
1123 
1124     /*
1125      * Apparently we can get a SIGPIPE when we call syslog, if
1126      * syslogd has died and been restarted.  Ignoring it seems
1127      * be sufficient.
1128      */
1129     (void) signal(SIGPIPE, SIG_IGN);
1130 }
1131 
1132 /*
1133  * set_ifunit - do things we need to do once we know which ppp
1134  * unit we are using.
1135  */
1136 void
1137 set_ifunit(iskey)
1138     int iskey;
1139 {
1140     sys_ifname();
1141     info("Using interface %s", ifname);
1142     script_setenv("IFNAME", ifname, iskey);
1143     if (iskey) {
1144 	create_pidfile();	/* write pid to file */
1145 	create_linkpidfile();
1146     }
1147 }
1148 
1149 /*
1150  * detach - detach us from the controlling terminal.
1151  */
1152 void
1153 detach()
1154 {
1155     pid_t pid;
1156     char numbuf[16];
1157 
1158     if (detached)
1159 	return;
1160     if ((pid = fork()) == (pid_t)-1) {
1161 	error("Couldn't detach (fork failed: %m)");
1162 	die(1);			/* or just return? */
1163     }
1164     if (pid != (pid_t)0) {
1165 	/* parent */
1166 	if (locked)
1167 	    (void) relock(pid);
1168 	exit(0);		/* parent dies */
1169     }
1170     (void) setsid();
1171 	/*
1172 	 * Fork again to relinquish session leadership. This is needed
1173 	 * to prevent the daemon from acquiring controlling terminal.
1174 	 */
1175     if ((pid = fork()) == (pid_t)-1) {
1176 	error("Couldn't detach (second fork failed: %m)");
1177 	die(1);			/* or just return? */
1178     }
1179     if (pid != (pid_t)0) {
1180 	/* parent */
1181 	if (locked)
1182 	    (void) relock(pid);
1183 	exit(0);		/* parent dies */
1184     }
1185     (void) chdir("/");
1186     (void) close(0);
1187     (void) close(1);
1188     (void) close(2);
1189     detached = 1;
1190     if (!log_to_file && !log_to_specific_fd)
1191 	log_to_fd = -1;
1192     /* update pid files if they have been written already */
1193     if (pidfilename[0] != '\0')
1194 	create_pidfile();
1195     if (linkpidfile[0] != '\0')
1196 	create_linkpidfile();
1197     (void) slprintf(numbuf, sizeof(numbuf), "%d", getpid());
1198     script_setenv("PPPD_PID", numbuf, 1);
1199 }
1200 
1201 /*
1202  * reopen_log - (re)open our connection to syslog.
1203  */
1204 void
1205 reopen_log()
1206 {
1207 #ifdef ULTRIX
1208     openlog("pppd", LOG_PID);
1209 #else
1210     openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
1211     (void) setlogmask(LOG_UPTO(LOG_INFO));
1212 #endif
1213 }
1214 
1215 /*
1216  * Create a file containing our process ID.
1217  */
1218 static void
1219 create_pidfile()
1220 {
1221     FILE *pidfile;
1222 
1223     (void) slprintf(pidfilename, sizeof(pidfilename), "%s%s.pid",
1224 	     _PATH_VARRUN, ifname);
1225     if ((pidfile = fopen(pidfilename, "w")) != NULL) {
1226 	(void) fprintf(pidfile, "%u\n", (unsigned)getpid());
1227 	(void) fclose(pidfile);
1228     } else {
1229 	error("Failed to create pid file %s: %m", pidfilename);
1230 	pidfilename[0] = '\0';
1231     }
1232 }
1233 
1234 static void
1235 create_linkpidfile()
1236 {
1237     FILE *pidfile;
1238 
1239     if (linkname[0] == '\0')
1240 	return;
1241     script_setenv("LINKNAME", linkname, 1);
1242     (void) slprintf(linkpidfile, sizeof(linkpidfile), "%sppp-%s.pid",
1243 	     _PATH_VARRUN, linkname);
1244     if ((pidfile = fopen(linkpidfile, "w")) != NULL) {
1245 	(void) fprintf(pidfile, "%u\n", (unsigned)getpid());
1246 	if (ifname[0] != '\0')
1247 	    (void) fprintf(pidfile, "%s\n", ifname);
1248 	(void) fclose(pidfile);
1249     } else {
1250 	error("Failed to create pid file %s: %m", linkpidfile);
1251 	linkpidfile[0] = '\0';
1252     }
1253 }
1254 
1255 /*
1256  * holdoff_end - called via a timeout when the holdoff period ends.
1257  */
1258 /*ARGSUSED*/
1259 static void
1260 holdoff_end(arg)
1261     void *arg;
1262 {
1263     new_phase(PHASE_DORMANT);
1264 }
1265 
1266 /* List of protocol names, to make our messages a little more informative. */
1267 struct protocol_list {
1268     u_short	proto;
1269     const char	*name;
1270 } protocol_list[] = {
1271     { 0x21,	"IP" },
1272     { 0x23,	"OSI Network Layer" },
1273     { 0x25,	"Xerox NS IDP" },
1274     { 0x27,	"DECnet Phase IV" },
1275     { 0x29,	"Appletalk" },
1276     { 0x2b,	"Novell IPX" },
1277     { 0x2d,	"VJ compressed TCP/IP" },
1278     { 0x2f,	"VJ uncompressed TCP/IP" },
1279     { 0x31,	"Bridging PDU" },
1280     { 0x33,	"Stream Protocol ST-II" },
1281     { 0x35,	"Banyan Vines" },
1282     { 0x37,	"Old VJ compressed TCP/IP" },
1283     { 0x39,	"AppleTalk EDDP" },
1284     { 0x3b,	"AppleTalk SmartBuffered" },
1285     { 0x3d,	"Multilink" },
1286     { 0x3f,	"NetBIOS Frame" },
1287     { 0x41,	"Cisco LAN Extension" },
1288     { 0x43,	"Ascom Timeplex" },
1289     { 0x45,	"Fujitsu Link Backup and Load Balancing (LBLB)" },
1290     { 0x47,	"DCA Remote Lan" },
1291     { 0x49,	"Serial Data Transport Protocol (PPP-SDTP)" },
1292     { 0x4b,	"SNA over 802.2" },
1293     { 0x4d,	"SNA" },
1294     { 0x4f,	"IP6 Header Compression" },
1295     { 0x51,	"KNX Bridging" },
1296     { 0x53,	"Encrypted" },
1297     { 0x55,	"per-link encrypted" },
1298     { 0x57,	"IPv6" },
1299     { 0x59,	"PPP Muxing" },
1300     { 0x6f,	"Stampede Bridging" },
1301     { 0x73,	"MP+" },
1302     { 0xc1,	"STMF" },
1303     { 0xfb,	"per-link compressed" },
1304     { 0xfd,	"compressed datagram" },
1305     { 0x0201,	"802.1d Hello Packets" },
1306     { 0x0203,	"IBM Source Routing BPDU" },
1307     { 0x0205,	"DEC LANBridge100 Spanning Tree" },
1308     { 0x0207,	"Cisco Discovery Protocol" },
1309     { 0x0231,	"Luxcom" },
1310     { 0x0233,	"Sigma Network Systems" },
1311     { 0x0235,	"Apple Client Server Protocol" },
1312     { 0x0281,	"MPLS Unicast" },
1313     { 0x0283,	"MPLS Multicast" },
1314     { 0x0285,	"IEEE p1284.4" },
1315     { 0x0287,	"ETSI TETRA TNP1" },
1316     { 0x4021,	"Stacker LZS" },
1317     { 0x8021,	"Internet Protocol Control Protocol" },
1318     { 0x8023,	"OSI Network Layer Control Protocol" },
1319     { 0x8025,	"Xerox NS IDP Control Protocol" },
1320     { 0x8027,	"DECnet Phase IV Control Protocol" },
1321     { 0x8029,	"Appletalk Control Protocol" },
1322     { 0x802b,	"Novell IPX Control Protocol" },
1323     { 0x8031,	"Bridging Control Protocol" },
1324     { 0x8033,	"Stream Protocol Control Protocol" },
1325     { 0x8035,	"Banyan Vines Control Protocol" },
1326     { 0x803f,	"NetBIOS Frames Control Protocol" },
1327     { 0x8041,	"Cisco LAN Extension Control Protocol" },
1328     { 0x8043,	"Ascom Timeplex Control Protocol" },
1329     { 0x8045,	"Fujitsu LBLB Control Protocol" },
1330     { 0x8047,	"DCA Remote Lan Network Control Protocol (RLNCP)" },
1331     { 0x8049,	"Serial Data Control Protocol (PPP-SDCP)" },
1332     { 0x804b,	"SNA over 802.2 Control Protocol" },
1333     { 0x804d,	"SNA Control Protocol" },
1334     { 0x8051,	"KNX Bridging Control Protocol" },
1335     { 0x8053,	"Encryption Control Protocol" },
1336     { 0x8055,	"Per-link Encryption Control Protocol" },
1337     { 0x8057,	"IPv6 Control Protocol" },
1338     { 0x806f,	"Stampede Bridging Control Protocol" },
1339     { 0x80c1,	"STMF Control Protocol" },
1340     { 0x80fb,	"Per-link Compression Control Protocol" },
1341     { 0x80fd,	"Compression Control Protocol" },
1342     { 0x8207,	"Cisco Discovery Control Protocol" },
1343     { 0x8235,	"Apple Client Server Control Protocol" },
1344     { 0x8281,	"MPLS Control Protocol" },
1345     { 0x8287,	"ETSI TETRA TNP1 Control Protocol" },
1346     { 0xc021,	"Link Control Protocol" },
1347     { 0xc023,	"Password Authentication Protocol" },
1348     { 0xc025,	"Link Quality Report" },
1349     { 0xc027,	"Shiva Password Authentication Protocol" },
1350     { 0xc029,	"CallBack Control Protocol (CBCP)" },
1351     { 0xc02b,	"Bandwidth Allocation Control Protocol" },
1352     { 0xc02d,	"BAP" },
1353     { 0xc081,	"Container Control Protocol" },
1354     { 0xc223,	"Challenge Handshake Authentication Protocol" },
1355     { 0xc227,	"Extensible Authentication Protocol" },
1356     { 0xc281,	"Funk Proprietary Authentication Protocol" },
1357     { 0,	NULL },
1358 };
1359 
1360 /*
1361  * protocol_name - find a name for a PPP protocol.
1362  */
1363 const char *
1364 protocol_name(proto)
1365     int proto;
1366 {
1367     struct protocol_list *lp;
1368 
1369     for (lp = protocol_list; lp->proto != 0; ++lp)
1370 	if (proto == lp->proto)
1371 	    return (lp->name);
1372     return (NULL);
1373 }
1374 
1375 static const char *phase_names[] = { PHASE__NAMES };
1376 
1377 const char *
1378 phase_name(pval)
1379     int pval;
1380 {
1381     static char buf[32];
1382 
1383     if (pval < 0 || pval >= Dim(phase_names)) {
1384 	(void) slprintf(buf, sizeof (buf), "unknown %d", pval);
1385 	return ((const char *)buf);
1386     }
1387     return (phase_names[pval]);
1388 }
1389 
1390 /*
1391  * get_input - called when incoming data is available.
1392  */
1393 static void
1394 get_input()
1395 {
1396     int len, i;
1397     u_char *p;
1398     u_short protocol;
1399     struct protent *protp;
1400     const char *pname;
1401 
1402     p = inpacket_buf;	/* point to beginning of packet buffer */
1403 
1404     len = read_packet(inpacket_buf);
1405     if (len < 0)
1406 	return;
1407 
1408     if (len == 0) {
1409 	notice("Modem hangup");
1410 	hungup = 1;
1411 	status = EXIT_HANGUP;
1412 	lcp_lowerdown(0);	/* serial link is no longer available */
1413 	link_terminated(0);
1414 	return;
1415     }
1416 
1417     if (debug /*&& (debugflags & DBG_INPACKET)*/)
1418 	dbglog("rcvd %P", p, len);
1419 
1420     if (len < PPP_HDRLEN) {
1421 	dbglog("Discarded short packet (%d < %d)", len, PPP_HDRLEN);
1422 	return;
1423     }
1424 
1425     p += 2;				/* Skip address and control */
1426     GETSHORT(protocol, p);
1427     len -= PPP_HDRLEN;
1428 
1429     pname = debug ? NULL : protocol_name(protocol);
1430 
1431     /*
1432      * Toss all non-LCP packets unless LCP is in Opened state and
1433      * discard non-authentication protocols if we're not yet
1434      * authenticated.
1435      */
1436     if ((protocol != PPP_LCP &&
1437 	(phase < PHASE_AUTHENTICATE || phase > PHASE_RUNNING)) ||
1438 	(phase <= PHASE_AUTHENTICATE &&
1439 	    !(protocol == PPP_LCP || protocol == PPP_LQR ||
1440 		protocol == PPP_PAP || protocol == PPP_CHAP))) {
1441 	    if (pname == NULL)
1442 		    dbglog("Discarded proto 0x%x in %s phase",
1443 			protocol, phase_name(phase));
1444 	    else
1445 		    dbglog("Discarded %s (0x%x) in %s phase",
1446 			pname, protocol, phase_name(phase));
1447 	return;
1448     }
1449 
1450     /*
1451      * Upcall the proper protocol input routine.
1452      */
1453     for (i = 0; (protp = protocols[i]) != NULL; ++i) {
1454 	if (protp->protocol == protocol && protp->enabled_flag) {
1455 	    (*protp->input)(0, p, len);
1456 	    return;
1457 	}
1458         if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
1459 	    && protp->datainput != NULL) {
1460 	    (*protp->datainput)(0, p, len);
1461 	    return;
1462 	}
1463     }
1464 
1465     if (debug) {
1466 	if (pname != NULL)
1467 	    warn("Unsupported protocol '%s' (0x%x) received", pname, protocol);
1468 	else
1469 	    warn("Unsupported protocol 0x%x received", protocol);
1470     }
1471     lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
1472 }
1473 
1474 /*
1475  * new_phase - signal the start of a new phase of pppd's operation.
1476  */
1477 void
1478 new_phase(p)
1479     int p;
1480 {
1481     if (new_phase_hook != NULL)
1482 	(*new_phase_hook)(p, phase);
1483     phase = p;
1484 }
1485 
1486 /*
1487  * die - clean up state and exit with the specified status.
1488  */
1489 void
1490 die(status)
1491     int status;
1492 {
1493     cleanup();
1494     if (phase != PHASE_EXIT) {
1495 	syslog(LOG_INFO, "Exit.");
1496 	new_phase(PHASE_EXIT);
1497     }
1498     exit(status);
1499 }
1500 
1501 /*
1502  * cleanup - restore anything which needs to be restored before we exit
1503  */
1504 static void
1505 cleanup()
1506 {
1507     sys_cleanup();  /* XXX: Need to check if this is okay after close_tty */
1508 
1509     if (fd_ppp >= 0) {
1510 	fd_ppp = -1;
1511 	disestablish_ppp(ttyfd);
1512     }
1513     if (real_ttyfd >= 0)
1514 	close_tty();
1515 
1516     if (pidfilename[0] != '\0' && unlink(pidfilename) < 0 && errno != ENOENT)
1517 	warn("unable to delete pid file %s: %m", pidfilename);
1518     pidfilename[0] = '\0';
1519     if (linkpidfile[0] != '\0' && unlink(linkpidfile) < 0 && errno != ENOENT)
1520 	warn("unable to delete pid file %s: %m", linkpidfile);
1521     linkpidfile[0] = '\0';
1522 
1523     if (locked) {
1524 	locked = 0;
1525 	unlock();
1526     }
1527 
1528 #ifdef HAVE_MULTILINK
1529     if (pppdb != NULL) {
1530 	cleanup_db();
1531 	pppdb = NULL;
1532     }
1533 #endif
1534 }
1535 
1536 /*
1537  * close_tty - restore the terminal device and close it.
1538  */
1539 static void
1540 close_tty()
1541 {
1542     int fd = real_ttyfd;
1543 
1544     real_ttyfd = -1;
1545 
1546     /* drop dtr to hang up */
1547     if (!default_device && modem) {
1548 	setdtr(fd, 0);
1549 	/*
1550 	 * This sleep is in case the serial port has CLOCAL set by default,
1551 	 * and consequently will reassert DTR when we close the device.
1552 	 */
1553 	(void) sleep(1);
1554     }
1555 
1556     restore_tty(fd);
1557 
1558     if (tty_mode != (mode_t) -1) {
1559 	if (fchmod(fd, tty_mode) != 0) {
1560 	    /* XXX if devnam is a symlink, this will change the link */
1561 	    if (chmod(devnam, tty_mode) != 0) {
1562 		error("Unable to chmod file %s: %m", devnam);
1563 	    }
1564 	}
1565     }
1566 
1567     (void) close(fd);
1568 }
1569 
1570 /*
1571  * update_link_stats - get stats at link termination.
1572  */
1573 void
1574 update_link_stats(u)
1575     int u;
1576 {
1577     struct timeval now;
1578     char numbuf[32];
1579 
1580     if (gettimeofday(&now, NULL) >= 0) {
1581 	link_connect_time = now.tv_sec - start_time.tv_sec;
1582 	(void) slprintf(numbuf, sizeof(numbuf), "%d", link_connect_time);
1583 	script_setenv("CONNECT_TIME", numbuf, 0);
1584     } else {
1585 	link_connect_time = 0;
1586     }
1587 
1588     if (get_ppp_stats(u, &link_stats)) {
1589 	(void) slprintf(numbuf, sizeof(numbuf), "%" PPP_COUNTER_F,
1590 	    link_stats.bytes_out);
1591 	script_setenv("BYTES_SENT", numbuf, 0);
1592 	(void) slprintf(numbuf, sizeof(numbuf), "%" PPP_COUNTER_F,
1593 	    link_stats.bytes_in);
1594 	script_setenv("BYTES_RCVD", numbuf, 0);
1595 	(void) slprintf(numbuf, sizeof(numbuf), "%" PPP_COUNTER_F,
1596 	    link_stats.pkts_in);
1597 	script_setenv("PKTS_RCVD", numbuf, 0);
1598 	(void) slprintf(numbuf, sizeof(numbuf), "%" PPP_COUNTER_F,
1599 	    link_stats.pkts_out);
1600 	script_setenv("PKTS_SENT", numbuf, 0);
1601 	link_stats_valid = 1;
1602     }
1603 }
1604 
1605 
1606 struct	callout {
1607     struct timeval	c_time;		/* time at which to call routine */
1608     void		*c_arg;		/* argument to routine */
1609     void		(*c_func) __P((void *)); /* routine */
1610     struct		callout *c_next;
1611 };
1612 
1613 static struct callout *callout = NULL;	/* Callout list */
1614 static struct timeval timenow;		/* Current time */
1615 
1616 /*
1617  * timeout - Schedule a timeout.
1618  *
1619  * Note that this timeout takes the number of seconds, NOT hz (as in
1620  * the kernel).
1621  */
1622 void
1623 timeout(func, arg, time)
1624     void (*func) __P((void *));
1625     void *arg;
1626     int time;
1627 {
1628     struct callout *newp, *p, **pp;
1629 
1630     MAINDEBUG(("Timeout %p:%p in %d seconds.", func, arg, time));
1631 
1632     /*
1633      * Allocate timeout.
1634      */
1635     if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL)
1636 	novm("callout structure for timeout.");
1637     newp->c_arg = arg;
1638     newp->c_func = func;
1639     (void) gettimeofday(&timenow, NULL);
1640     newp->c_time.tv_sec = timenow.tv_sec + time;
1641     newp->c_time.tv_usec = timenow.tv_usec;
1642 
1643     /*
1644      * Find correct place and link it in.
1645      */
1646     for (pp = &callout; (p = *pp) != NULL; pp = &p->c_next)
1647 	if (newp->c_time.tv_sec < p->c_time.tv_sec
1648 	    || (newp->c_time.tv_sec == p->c_time.tv_sec
1649 		&& newp->c_time.tv_usec < p->c_time.tv_usec))
1650 	    break;
1651     newp->c_next = p;
1652     *pp = newp;
1653 }
1654 
1655 
1656 /*
1657  * untimeout - Unschedule a timeout.
1658  */
1659 void
1660 untimeout(func, arg)
1661     void (*func) __P((void *));
1662     void *arg;
1663 {
1664     struct callout **copp, *freep;
1665 
1666     MAINDEBUG(("Untimeout %p:%p.", func, arg));
1667 
1668     /*
1669      * Find first matching timeout and remove it from the list.
1670      */
1671     for (copp = &callout; (freep = *copp) != NULL; copp = &freep->c_next)
1672 	if (freep->c_func == func && freep->c_arg == arg) {
1673 	    *copp = freep->c_next;
1674 	    free((char *) freep);
1675 	    break;
1676 	}
1677 }
1678 
1679 
1680 /*
1681  * calltimeout - Call any timeout routines which are now due.
1682  */
1683 static void
1684 calltimeout()
1685 {
1686     struct callout *p;
1687 
1688     while (callout != NULL) {
1689 	p = callout;
1690 
1691 	if (gettimeofday(&timenow, NULL) < 0)
1692 	    fatal("Failed to get time of day: %m");
1693 	if (!(p->c_time.tv_sec < timenow.tv_sec
1694 	      || (p->c_time.tv_sec == timenow.tv_sec
1695 		  && p->c_time.tv_usec <= timenow.tv_usec)))
1696 	    break;		/* no, it's not time yet */
1697 
1698 	callout = p->c_next;
1699 	(*p->c_func)(p->c_arg);
1700 
1701 	free((char *) p);
1702     }
1703 }
1704 
1705 
1706 /*
1707  * timeleft - return the length of time until the next timeout is due.
1708  */
1709 static struct timeval *
1710 timeleft(tvp)
1711     struct timeval *tvp;
1712 {
1713     if (callout == NULL)
1714 	return (NULL);
1715 
1716     (void) gettimeofday(&timenow, NULL);
1717     tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
1718     tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
1719     if (tvp->tv_usec < 0) {
1720 	tvp->tv_usec += 1000000;
1721 	tvp->tv_sec -= 1;
1722     }
1723     if (tvp->tv_sec < 0)
1724 	tvp->tv_sec = tvp->tv_usec = 0;
1725 
1726     return (tvp);
1727 }
1728 
1729 
1730 /*
1731  * kill_my_pg - send a signal to our process group, and ignore it ourselves.
1732  */
1733 static void
1734 kill_my_pg(sig)
1735     int sig;
1736 {
1737     struct sigaction act, oldact;
1738     sigset_t mask;
1739 
1740     BZERO(&act, sizeof (act));
1741     act.sa_handler = SIG_IGN;
1742     (void) sigemptyset(&mask);
1743     (void) sigaddset(&mask, sig);
1744     /*
1745      * Ignore signal 'sig' temporarily, before finally re-activating the
1746      * original handler.  We need to do it in the following sequence, since
1747      * otherwise the signal handler for 'sig' will be called forever.
1748      */
1749     if (sigaction(sig, &act, &oldact) < 0) {
1750 	fatal("kill_my_pg: couldn't establish signal handler (%d): %m", sig);
1751     }
1752     (void) sigprocmask(SIG_UNBLOCK, &mask, NULL);
1753     /*
1754      * Send signal 'sig' to all processes whose process group ID is equal
1755      * to the process group ID of the sender.
1756      */
1757     (void) kill(0, sig);
1758     if (sigaction(sig, &oldact, NULL) < 0) {
1759 	fatal("kill_my_pg: couldn't establish signal handler (%d): %m", sig);
1760     }
1761 }
1762 
1763 
1764 /*
1765  * hup - Catch SIGHUP signal.
1766  *
1767  * Indicates that the physical layer has been disconnected.
1768  * We don't rely on this indication; if the user has sent this
1769  * signal, we just take the link down.
1770  */
1771 static void
1772 hup(sig)
1773     int sig;
1774 {
1775     info("Hangup (SIGHUP)");
1776     kill_link = 1;
1777     if (status != EXIT_HANGUP)
1778 	status = EXIT_USER_REQUEST;
1779     if (conn_running > 0)
1780 	/* Send the signal to the [dis]connector process(es) also */
1781 	kill_my_pg(sig);
1782     if (charshunt_pid)
1783 	(void) kill(charshunt_pid, sig);
1784     if (waiting)
1785 	siglongjmp(sigjmp, 1);
1786 }
1787 
1788 
1789 /*
1790  * term - Catch SIGTERM signal and SIGINT signal (^C/del).
1791  *
1792  * Indicates that we should initiate a graceful disconnect and exit.
1793  */
1794 /*ARGSUSED*/
1795 static void
1796 term(sig)
1797     int sig;
1798 {
1799     info("Terminating on signal %d.", sig);
1800     persist = 0;		/* don't try to restart */
1801     kill_link = 1;
1802     status = EXIT_USER_REQUEST;
1803     if (conn_running > 0)
1804 	/* Send the signal to the [dis]connector process(es) also */
1805 	kill_my_pg(sig);
1806     if (charshunt_pid)
1807 	(void) kill(charshunt_pid, sig);
1808     if (waiting)
1809 	siglongjmp(sigjmp, 1);
1810 }
1811 
1812 
1813 /*
1814  * chld - Catch SIGCHLD signal.
1815  * Sets a flag so we will call reap_kids in the mainline.
1816  */
1817 /*ARGSUSED*/
1818 static void
1819 chld(sig)
1820     int sig;
1821 {
1822     got_sigchld = 1;
1823     if (waiting)
1824 	siglongjmp(sigjmp, 1);
1825 }
1826 
1827 /*
1828  * toggle_debug - Catch SIGUSR1 signal.
1829  *
1830  * Toggle debug flag.
1831  */
1832 /*ARGSUSED*/
1833 static void
1834 toggle_debug(sig)
1835     int sig;
1836 {
1837     if (debug) {
1838 	print_ncpstate(0, NULL);
1839 	dbglog("debug logging disabled");
1840 	(void) setlogmask(LOG_UPTO(LOG_WARNING));
1841 	debug = 0;
1842     } else {
1843 	(void) setlogmask(LOG_UPTO(LOG_DEBUG));
1844 	dbglog("debug logging enabled");
1845 	print_ncpstate(0, NULL);
1846 	debug = 1;
1847     }
1848 }
1849 
1850 
1851 /*
1852  * open_ccp - Catch SIGUSR2 signal.
1853  *
1854  * Try to (re)negotiate compression.
1855  */
1856 /*ARGSUSED*/
1857 static void
1858 open_ccp(sig)
1859     int sig;
1860 {
1861     open_ccp_flag = 1;
1862     if (waiting)
1863 	siglongjmp(sigjmp, 1);
1864 }
1865 
1866 
1867 /*
1868  * bad_signal - We've caught a fatal signal.  Clean up state and exit.
1869  */
1870 static void
1871 bad_signal(sig)
1872     int sig;
1873 {
1874     static int crashed = 0;
1875 
1876     if (crashed)
1877 	_exit(127);
1878     crashed = 1;
1879     error("Fatal signal %d", sig);
1880     if (conn_running > 0)
1881 	kill_my_pg(SIGTERM);
1882     if (charshunt_pid)
1883 	(void) kill(charshunt_pid, SIGTERM);
1884     die(127);
1885 }
1886 
1887 
1888 /*
1889  * device_script - run a program to talk to the serial device
1890  * (e.g. to run the connector or disconnector script).
1891  */
1892 static int
1893 device_script(program, in, out, dont_wait, optname)
1894     char *program;
1895     int in, out;
1896     int dont_wait;
1897     char *optname;
1898 {
1899     pid_t pid;
1900     int status = -1;
1901     int errfd;
1902     int envpipe[2];
1903 
1904     envpipe[0] = envpipe[1] = -1;
1905     if (!dont_wait && device_pipe_hook != NULL && pipe(envpipe) == -1) {
1906 	error("Cannot create pipe for child: %m");
1907 	return (-1);
1908     }
1909 
1910     ++conn_running;
1911     pid = fork();
1912 
1913     if (pid == (pid_t)-1) {
1914 	--conn_running;
1915 	error("Failed to create child process: %m");
1916 	return (-1);
1917     }
1918 
1919     if (pid == (pid_t)0) {
1920 	sys_close();
1921 	closelog();
1922 	if (envpipe[0] >= 0) {
1923 	    if (envpipe[1] <= 2)
1924 		envpipe[1] = dup(envpipe[1]);
1925 	    (void) close(envpipe[0]);
1926 	}
1927 	if (in == 2) {
1928 	    /* aargh!!! */
1929 	    int newin = dup(in);
1930 	    if (in == out)
1931 		out = newin;
1932 	    in = newin;
1933 	} else if (out == 2) {
1934 	    out = dup(out);
1935 	}
1936 	if (log_to_fd >= 0) {
1937 	    if (log_to_fd != 2) {
1938 		if (dup2(log_to_fd, 2) < 0)
1939 		    error("dup2(log_to_fd, STDERR) failed: %m");
1940 	    }
1941 	} else {
1942 	    (void) close(2);
1943 	    errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0600);
1944 	    if (errfd >= 0 && errfd != 2) {
1945 		if (dup2(errfd, 2) < 0)
1946 		    error("dup2(errfd, STDERR) failed: %m");
1947 		(void) close(errfd);
1948 	    }
1949 	}
1950 	if (in != 0) {
1951 	    if (out == 0)
1952 		out = dup(out);
1953 	    if (dup2(in, 0) < 0)
1954 		error("dup2(in, STDIN) failed: %m");
1955 	}
1956 	if (out != 1) {
1957 	    if (dup2(out, 1) < 0)
1958 		error("dup2(out, STDOUT) failed: %m");
1959 	}
1960 	if (envpipe[0] >= 0 && dup2(envpipe[1], 3) < 0)
1961 	    error("dup2(pipe, pipeout) failed: %m");
1962 	if (real_ttyfd > 2)
1963 	    (void) close(real_ttyfd);
1964 	if (pty_master > 2)
1965 	    (void) close(pty_master);
1966 	if (pty_slave > 2) {
1967 	    (void) close(pty_slave);
1968 	    pty_slave = -1;
1969 	}
1970 	(void) setuid(uid);
1971 	if (getuid() != uid) {
1972 	    error("setuid failed");
1973 	    exit(1);
1974 	}
1975 	(void) setgid(getgid());
1976 	if (script_env != NULL) {
1977 	    while (*script_env != NULL) {
1978 		if (putenv(*script_env) == -1)
1979 		    warn("unable to set %s for %s: %m", *script_env, program);
1980 		script_env++;
1981 	    }
1982 	}
1983 	(void) execl("/bin/sh", "sh", "-c", program, (char *)0);
1984 	error("could not exec /bin/sh: %m");
1985 	exit(99);
1986 	/* NOTREACHED */
1987     }
1988 
1989     if (debug)
1990 	dbglog("%s option: '%s' started (pid %d)", optname, program, pid);
1991     if (dont_wait) {
1992 	record_child(pid, program, NULL, NULL);
1993 	status = 0;
1994     } else {
1995 	if (envpipe[0] >= 0) {
1996 	    (void) close(envpipe[1]);
1997 	    (*device_pipe_hook)(envpipe[0]);
1998 	}
1999 	while (waitpid(pid, &status, 0) < 0) {
2000 	    if (errno == EINTR)
2001 		continue;
2002 	    fatal("error waiting for (dis)connection process: %m");
2003 	}
2004 	if (envpipe[0] >= 0)
2005 	    (void) close(envpipe[0]);
2006 	--conn_running;
2007     }
2008 
2009     return (status == 0 ? 0 : -1);
2010 }
2011 
2012 
2013 /*
2014  * run-program - execute a program with given arguments,
2015  * but don't wait for it.
2016  * If the program can't be executed, logs an error unless
2017  * must_exist is 0 and the program file doesn't exist.
2018  * Returns -1 if it couldn't fork, 0 if the file doesn't exist
2019  * or isn't an executable plain file, or the process ID of the child.
2020  * If done != NULL, (*done)(arg, int) will be called later (within
2021  * reap_kids) if this routine returns value > 0.
2022  */
2023 pid_t
2024 run_program(prog, args, must_exist, done, arg)
2025     char *prog;
2026     char **args;
2027     int must_exist;
2028     void (*done) __P((void *arg, int status));
2029     void *arg;
2030 {
2031     pid_t pid;
2032     struct stat sbuf;
2033     int retv;
2034 
2035     /*
2036      * First check if the file exists and is executable.
2037      * We don't use access() because that would use the
2038      * real user-id, which might not be root, and the script
2039      * might be accessible only to root.
2040      */
2041     errno = EINVAL;
2042     if (stat(prog, &sbuf) < 0 || !S_ISREG(sbuf.st_mode)
2043 	|| (sbuf.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0) {
2044 	if (must_exist || errno != ENOENT)
2045 	    warn("Can't execute %s: %m", prog);
2046 	return (0);
2047     }
2048 
2049     if (updown_script_hook != NULL) {
2050 	retv = (*updown_script_hook)((const char ***)&args);
2051 	if (retv == -1) {
2052 	    return (-1);
2053 	}
2054     }
2055 
2056     pid = fork();
2057     if (pid == (pid_t)-1) {
2058 	error("Failed to create child process for %s: %m", prog);
2059 	return (-1);
2060     }
2061     if (pid == (pid_t)0) {
2062 	int new_fd;
2063 
2064 	/* Leave the current location */
2065 	(void) setsid();	/* No controlling tty. */
2066 	(void) umask (S_IRWXG|S_IRWXO);
2067 	(void) chdir ("/");	/* no current directory. */
2068 	(void) setuid(0);	/* set real UID = root */
2069 	(void) setgid(getegid());
2070 
2071 	/* Ensure that nothing of our device environment is inherited. */
2072 	sys_close();
2073 	closelog();
2074 	(void) close(0);
2075 	(void) close(1);
2076 	(void) close(2);
2077 	(void) close(ttyfd);  /* tty interface to the ppp device */
2078 	if (real_ttyfd >= 0)
2079 	    (void) close(real_ttyfd);
2080 
2081         /* Don't pass handles to the PPP device, even by accident. */
2082 	new_fd = open (_PATH_DEVNULL, O_RDWR);
2083 	if (new_fd >= 0) {
2084 	    if (new_fd != 0) {
2085 	        if (dup2(new_fd, 0) < 0) /* stdin <- /dev/null */
2086 		    error("dup2(/dev/null, STDIN) failed: %m");
2087 		(void) close(new_fd);
2088 	    }
2089 	    if (dup2(0, 1) < 0) /* stdout -> /dev/null */
2090 		error("dup2(/dev/null, STDOUT) failed: %m");
2091 	    if (dup2(0, 2) < 0) /* stderr -> /dev/null */
2092 		error("dup2(/dev/null, STDERR) failed: %m");
2093 	}
2094 
2095 #ifdef BSD
2096 	/* Force the priority back to zero if pppd is running higher. */
2097 	if (setpriority (PRIO_PROCESS, 0, 0) < 0)
2098 	    warn("can't reset priority to 0: %m");
2099 #endif
2100 
2101 	/* SysV recommends a second fork at this point. */
2102 
2103 	/* run the program */
2104 	(void) execve(prog, args, script_env);
2105 	if (must_exist || errno != ENOENT) {
2106 	    /* have to reopen the log, there's nowhere else
2107 	       for the message to go. */
2108 	    reopen_log();
2109 	    syslog(LOG_ERR, "Can't execute %s: %m", prog);
2110 	    closelog();
2111 	}
2112 	_exit(-1);
2113     }
2114 
2115     if (debug)
2116 	dbglog("Script %s started (pid %d)", prog, pid);
2117     record_child(pid, prog, done, arg);
2118 
2119     return (pid);
2120 }
2121 
2122 
2123 /*
2124  * record_child - add a child process to the list for reap_kids
2125  * to use.
2126  */
2127 static void
2128 record_child(pid, prog, done, arg)
2129     pid_t pid;
2130     char *prog;
2131     void (*done) __P((void *, int));
2132     void *arg;
2133 {
2134     struct subprocess *chp;
2135 
2136     ++n_children;
2137 
2138     chp = (struct subprocess *) malloc(sizeof(struct subprocess));
2139     if (chp == NULL) {
2140 	warn("losing track of %s process", prog);
2141     } else {
2142 	chp->pid = pid;
2143 	chp->prog = prog;
2144 	chp->done = done;
2145 	chp->arg = arg;
2146 	chp->next = children;
2147 	children = chp;
2148     }
2149 }
2150 
2151 
2152 /*
2153  * reap_kids - get status from any dead child processes,
2154  * and log a message for abnormal terminations.
2155  */
2156 static int
2157 reap_kids(waitfor)
2158     int waitfor;
2159 {
2160     pid_t pid;
2161     int status, i;
2162     struct subprocess *chp, **prevp;
2163 
2164     got_sigchld = 0;
2165     if (n_children == 0)
2166 	return (0);
2167 
2168     /*CONSTANTCONDITION*/
2169     while (1) {
2170 	pid = waitpid(-1, &status, (waitfor ? 0 : WNOHANG));
2171 	if (pid == 0) {
2172 	    break;	/* return 0 */
2173 	} else if (pid == -1) {
2174 	    if (errno == EINTR)
2175 		continue;
2176 	    if (errno != ECHILD)
2177 		error("Error waiting for child process: %m");
2178 	    return (-1);
2179 	} else {
2180 	    for (prevp = &children; (chp = *prevp) != NULL;
2181 		prevp = &chp->next) {
2182 		if (chp->pid == pid) {
2183 		    --n_children;
2184 		    *prevp = chp->next;
2185 		    break;
2186 		}
2187 	    }
2188 	    if (WIFSIGNALED(status) || WIFSTOPPED(status)) {
2189 		i = WIFSIGNALED(status) ? WTERMSIG(status) : WSTOPSIG(status);
2190 		warn("Child process %s (pid %d) %s with signal %d (%s)",
2191 		    (chp != NULL ? chp->prog : "??"), pid,
2192 		    (WIFSIGNALED(status) ? "terminated" : "stopped"),
2193 		    i, signal_name(i));
2194 	    } else if (debug) {
2195 		dbglog("Child process %s finished (pid %d), status = %d",
2196 		       (chp != NULL ? chp->prog: "??"), pid,
2197 		    WEXITSTATUS(status));
2198 	    }
2199 	    if ((chp != NULL) && (chp->done != NULL))
2200 		(*chp->done)(chp->arg, status);
2201 	    if (chp != NULL)
2202 		free(chp);
2203 	}
2204     }
2205     return (0);
2206 }
2207 
2208 /*
2209  * infanticide - timeout while waiting for child process.
2210  */
2211 /*ARGSUSED*/
2212 static void
2213 infanticide(sig)
2214     int sig;
2215 {
2216     struct subprocess *chp;
2217     static int runcount = 0;
2218 
2219     if (runcount < 2) {
2220 	for (chp = children; chp != NULL; chp = chp->next)
2221 	    (void) kill(chp->pid, runcount == 0 ? SIGTERM : SIGKILL);
2222     } else {
2223 	kill_my_pg(SIGTERM);
2224 	/* Quit and hope for the best. */
2225 	n_children = 0;
2226     }
2227     runcount++;
2228 }
2229 
2230 /*
2231  * Perform final wait before exiting.
2232  */
2233 static void
2234 final_reap()
2235 {
2236     struct sigaction sa;
2237     struct subprocess *chp;
2238 
2239     if (n_children > 0 && debug) {
2240 	dbglog("Waiting for %d child processes...", n_children);
2241 	for (chp = children; chp != NULL; chp = chp->next)
2242 	    dbglog("  pid %d: %s", chp->pid, chp->prog);
2243     }
2244     BZERO(&sa, sizeof (sa));
2245 /*CONSTANTCONDITION*/ SIGNAL(SIGALRM, infanticide);
2246     while (n_children > 0) {
2247 	(void) alarm(7);
2248 	if (reap_kids(1) < 0)
2249 	    break;
2250     }
2251     (void) alarm(0);
2252 }
2253 
2254 /*
2255  * novm - log an error message saying we ran out of memory, and die.
2256  */
2257 void
2258 novm(msg)
2259     char *msg;
2260 {
2261     fatal("Virtual memory exhausted allocating %s\n", msg);
2262 }
2263 
2264 /*
2265  * script_setenv - set an environment variable value to be used
2266  * for scripts that we run (e.g. ip-up, auth-up, etc.)
2267  */
2268 void
2269 script_setenv(var, value, iskey)
2270     const char *var;
2271     const char *value;
2272     int iskey;
2273 {
2274     size_t varl = strlen(var);
2275     size_t vl = varl + strlen(value) + 2;
2276     int i;
2277     char *p, *newstring;
2278 
2279     /*
2280      * XXX: Can we assert that a tdb write lock is held here ?  It appears that
2281      *	    Linux's use of tdb is not safe.
2282      */
2283     newstring = (char *) malloc(vl+1);
2284     if (newstring == NULL) {
2285 	novm("script environment string");
2286 	return;
2287     }
2288     *newstring++ = iskey;
2289     (void) slprintf(newstring, vl, "%s=%s", var, value);
2290 
2291     /* check if this variable is already set */
2292     if (script_env != NULL) {
2293 	for (i = 0; (p = script_env[i]) != NULL; ++i) {
2294 	    if (strncmp(p, var, varl) == 0 && p[varl] == '=') {
2295 #ifdef HAVE_MULTILINK
2296 		if (p[-1] != '\0' && pppdb != NULL)
2297 		    delete_db_key(p);
2298 #endif
2299 		free(p-1);
2300 		script_env[i] = newstring;
2301 #ifdef HAVE_MULTILINK
2302 		if (iskey && pppdb != NULL)
2303 		    add_db_key(newstring);
2304 		update_db_entry();
2305 #endif
2306 		return;
2307 	    }
2308 	}
2309     } else {
2310 	/* no space allocated for script env. ptrs. yet */
2311 	i = 0;
2312 	script_env = (char **) malloc(16 * sizeof(char *));
2313 	if (script_env == NULL) {
2314 	    novm("script environment variable.");
2315 	    return;
2316 	}
2317 	s_env_nalloc = 16;
2318     }
2319 
2320     /* reallocate script_env with more space if needed */
2321     if (i + 1 >= s_env_nalloc) {
2322 	int new_n = i + 17;
2323 	char **newenv = (char **) realloc((void *)script_env,
2324 					  new_n * sizeof(char *));
2325 	if (newenv == NULL) {
2326 	    novm("expanded script environment variable.");
2327 	    return;
2328 	}
2329 	script_env = newenv;
2330 	s_env_nalloc = new_n;
2331     }
2332 
2333     script_env[i] = newstring;
2334     script_env[i+1] = NULL;
2335 
2336 #ifdef HAVE_MULTILINK
2337     if (pppdb != NULL) {
2338 	if (iskey)
2339 	    add_db_key(newstring);
2340 	update_db_entry();
2341     }
2342 #endif
2343 }
2344 
2345 /*
2346  * script_unsetenv - remove a variable from the environment
2347  * for scripts.
2348  */
2349 void
2350 script_unsetenv(var)
2351     const char *var;
2352 {
2353     int vl = strlen(var);
2354     int i;
2355     char *p;
2356 
2357     /*
2358      * XXX: Can we assert that a tdb write lock is held here ?  It appears that
2359      *	    Linux's use of tdb is not safe.
2360      */
2361     if (script_env == NULL)
2362 	return;
2363     for (i = 0; (p = script_env[i]) != NULL; ++i) {
2364 	if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
2365 #ifdef HAVE_MULTILINK
2366 	    if (p[-1] != '\0' && pppdb != NULL)
2367 		delete_db_key(p);
2368 #endif
2369 	    free(p-1);
2370 	    while ((script_env[i] = script_env[i+1]) != NULL)
2371 		++i;
2372 	    break;
2373 	}
2374     }
2375 #ifdef HAVE_MULTILINK
2376     if ((pppdb != NULL) && (p != NULL))
2377 	update_db_entry();
2378 #endif
2379 }
2380 
2381 /*
2382  * script_getenv - find a variable in the script environment.
2383  */
2384 const char *
2385 script_getenv(var)
2386     const char *var;
2387 {
2388     int vl = strlen(var);
2389     int i;
2390     char *p;
2391 
2392     if (script_env == NULL)
2393 	return (NULL);
2394     for (i = 0; (p = script_env[i]) != NULL; ++i) {
2395 	if (strncmp(p, var, vl) == 0 && p[vl] == '=')
2396 	    return ((const char *)p+vl+1);
2397     }
2398     return (NULL);
2399 }
2400 
2401 #ifdef HAVE_MULTILINK
2402 /*
2403  * update_db_entry - update our entry in the database.
2404  */
2405 static void
2406 update_db_entry()
2407 {
2408     TDB_DATA key, dbuf;
2409     int vlen, i;
2410     char *p, *q, *vbuf;
2411 
2412     if (script_env == NULL)
2413 	return;
2414     /*
2415      * vlen needs to be initialized as 1, or otherwise, the last string
2416      * is truncated by slprintf.
2417      */
2418     vlen = 1;
2419     for (i = 0; (p = script_env[i]) != NULL; ++i)
2420 	vlen += strlen(p) + 1;
2421     vbuf = malloc(vlen);
2422     if (vbuf == NULL)
2423 	novm("database entry");
2424     q = vbuf;
2425     for (i = 0; (p = script_env[i]) != NULL; ++i)
2426 	q += slprintf(q, vbuf + vlen - q, "%s;", p);
2427 
2428     key.dptr = db_key;
2429     key.dsize = strlen(db_key);
2430     dbuf.dptr = vbuf;
2431     dbuf.dsize = vlen;
2432     if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
2433 	error("tdb_store failed: %s", tdb_error(pppdb));
2434 }
2435 
2436 /*
2437  * add_db_key - add a key that we can use to look up our database entry.
2438  */
2439 static void
2440 add_db_key(str)
2441     const char *str;
2442 {
2443     TDB_DATA key, dbuf;
2444 
2445     key.dptr = (char *) str;
2446     key.dsize = strlen(str);
2447     dbuf.dptr = db_key;
2448     dbuf.dsize = strlen(db_key);
2449     if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
2450 	error("tdb_store key failed: %s", tdb_error(pppdb));
2451 }
2452 
2453 /*
2454  * delete_db_key - delete a key for looking up our database entry.
2455  */
2456 static void
2457 delete_db_key(str)
2458     const char *str;
2459 {
2460     TDB_DATA key;
2461 
2462     key.dptr = (char *) str;
2463     key.dsize = strlen(str);
2464     (void) tdb_delete(pppdb, key);
2465 }
2466 
2467 /*
2468  * cleanup_db - delete all the entries we put in the database.
2469  */
2470 static void
2471 cleanup_db()
2472 {
2473     TDB_DATA key;
2474     int i;
2475     char *p;
2476 
2477     key.dptr = db_key;
2478     key.dsize = strlen(db_key);
2479     (void) tdb_delete(pppdb, key);
2480     for (i = 0; (p = script_env[i]) != NULL; ++i)
2481 	if (p[-1] != '\0')
2482 	    delete_db_key(p);
2483 }
2484 #endif /* HAVE_MULTILINK */
2485 
2486 /*
2487  * open_socket - establish a stream socket connection to the nominated
2488  * host and port.
2489  * XXX: Need IPv6 support for those systems that support it (use getaddrinfo),
2490  *	but requires portability changes.
2491  */
2492 static int
2493 open_socket(dest)
2494     char *dest;
2495 {
2496     char *sep, *endp = NULL;
2497     int sock;
2498     int port = -1;
2499     u_int32_t host;
2500     struct hostent *hent = NULL;
2501     struct sockaddr_in sad;
2502     struct servent *se;
2503 
2504     /* parse host:port and resolve host to an IP address */
2505     sep = strchr(dest, ':');
2506     if (sep != NULL) {
2507 	se = getservbyname((const char *)sep+1, "tcp");
2508 	if (se != NULL) {
2509 	    port = ntohs(se->s_port);
2510 	} else {
2511 	    port = strtol(sep+1, &endp, 10);
2512 	    if (endp == sep+1 || *endp != '\0') {
2513 		error("Can't parse host:port for socket destination");
2514 		return (-1);
2515 	    }
2516 	}
2517     }
2518     if (port < 0 || port > 65535 || sep == dest) {
2519 	error("Can't parse host:port for socket destination");
2520 	return (-1);
2521     }
2522     *sep = '\0';
2523     host = inet_addr(dest);
2524     if (host == (u_int32_t) -1) {
2525 	hent = gethostbyname(dest);
2526 	if (hent == NULL) {
2527 	    error("%s: unknown host in socket option", dest);
2528 	    *sep = ':';
2529 	    return (-1);
2530 	}
2531 	BCOPY(hent->h_addr_list[0], &host, sizeof(host));
2532 	hent->h_addr_list++;
2533     }
2534     *sep = ':';
2535 
2536     for (;;) {
2537 	/* get a socket and connect it to the other end */
2538 	sock = socket(PF_INET, SOCK_STREAM, 0);
2539 	if (sock < 0) {
2540 	    error("Can't create socket: %m");
2541 	    return (-1);
2542 	}
2543 	BZERO(&sad, sizeof(sad));
2544 	sad.sin_family = AF_INET;
2545 	sad.sin_port = htons(port);
2546 	sad.sin_addr.s_addr = host;
2547 	if (connect(sock, (struct sockaddr *)&sad, sizeof(sad)) >= 0) {
2548 	    break;  /* return sock file descriptor */
2549 	}
2550 	if ((hent != NULL) && (hent->h_addr_list != NULL)) {
2551 	    BCOPY(hent->h_addr_list[0], &host, sizeof(host));
2552 	    hent->h_addr_list++;
2553 	    (void) close(sock);
2554 	    continue;
2555 	}
2556 	error("Can't connect to %s: %m", dest);
2557 	(void) close(sock);
2558 	return (-1);
2559     }
2560     return (sock);
2561 }
2562 
2563 /*
2564  * print_ncpstate - prints out current NCP state.
2565  *
2566  * We're normally called from SIGUSR1 here, but this is safe because
2567  * these signals are blocked unless we're idle waiting for events.
2568  * There's no need to otherwise lock the data structures referenced.
2569  */
2570 void
2571 print_ncpstate(unit, strptr)
2572     int unit;
2573     FILE *strptr;
2574 {
2575     struct protent *protp;
2576     int i;
2577 
2578     (void) flprintf(strptr, "In %s phase\n", phase_name(phase));
2579     for (i = 0; (protp = protocols[i]) != NULL; ++i) {
2580 	if (protp->print_stat != NULL)
2581 	    (*protp->print_stat)(unit, strptr);
2582     }
2583     sys_print_state(strptr);
2584 }
2585 
2586 /*
2587  * start_charshunt - create a child process to run the character shunt.
2588  */
2589 static int
2590 start_charshunt(ifd, ofd)
2591     int ifd, ofd;
2592 {
2593     pid_t cpid;
2594 
2595     cpid = fork();
2596     if (cpid == (pid_t)-1) {
2597 	error("Can't fork process for character shunt: %m");
2598 	return (0);
2599     }
2600     if (cpid == (pid_t)0) {
2601 	/* child */
2602 	(void) close(pty_slave);
2603 	pty_slave = -1;
2604 	(void) setgid(getgid());
2605 	(void) setuid(uid);
2606 	if (getuid() != uid)
2607 	    fatal("setuid failed");
2608 	if (!nodetach)
2609 	    log_to_fd = -1;
2610 	charshunt(ifd, ofd, record_file);
2611 	exit(0);
2612     }
2613     charshunt_pid = cpid;
2614     (void) close(pty_master);
2615     pty_master = -1;
2616     ttyfd = pty_slave;
2617     record_child(cpid, "pppd (charshunt)", charshunt_done, NULL);
2618     return (1);
2619 }
2620 
2621 /*ARGSUSED*/
2622 static void
2623 charshunt_done(arg, status)
2624     void *arg;
2625     int status;
2626 {
2627     charshunt_pid = (pid_t)0;
2628 }
2629 
2630 static void
2631 reportme(int signo)
2632 {
2633     dbglog("charshunt taking signal %d", signo);
2634     exit(1);
2635 }
2636 
2637 /*
2638  * charshunt - the character shunt, which passes characters between
2639  * the pty master side and the serial port (or stdin/stdout).
2640  * This runs as the user (not as root).
2641  * (We assume ofd >= ifd which is true the way this gets called. :-).
2642  */
2643 static void
2644 charshunt(ifd, ofd, record_file)
2645     int ifd, ofd;
2646     char *record_file;
2647 {
2648     int n, nfds;
2649     fd_set ready, writey;
2650     u_char *ibufp, *obufp;
2651     int nibuf, nobuf;
2652     int flags;
2653     struct timeval lasttime;
2654     FILE *recordf = NULL;
2655     int ilevel, olevel, max_level;
2656     struct timeval levelt, tout, *top;
2657 
2658     /*
2659      * Reset signal handlers.
2660      */
2661     (void) signal(SIGHUP, SIG_IGN);		/* Hangup */
2662     (void) signal(SIGINT, reportme);		/* Interrupt */
2663     (void) signal(SIGTERM, reportme);		/* Terminate */
2664     (void) signal(SIGCHLD, reportme);
2665     (void) signal(SIGUSR1, reportme);
2666     (void) signal(SIGUSR2, reportme);
2667     (void) signal(SIGABRT, reportme);
2668     (void) signal(SIGALRM, reportme);
2669     (void) signal(SIGFPE, reportme);
2670     (void) signal(SIGILL, reportme);
2671     (void) signal(SIGPIPE, reportme);
2672     (void) signal(SIGQUIT, reportme);
2673 #ifndef DEBUG
2674     (void) signal(SIGSEGV, reportme);
2675 #endif
2676 #ifdef SIGBUS
2677     (void) signal(SIGBUS, reportme);
2678 #endif
2679 #ifdef SIGEMT
2680     (void) signal(SIGEMT, reportme);
2681 #endif
2682 #ifdef SIGPOLL
2683     (void) signal(SIGPOLL, reportme);
2684 #endif
2685 #ifdef SIGPROF
2686     (void) signal(SIGPROF, reportme);
2687 #endif
2688 #ifdef SIGSYS
2689     (void) signal(SIGSYS, reportme);
2690 #endif
2691 #ifdef SIGTRAP
2692     (void) signal(SIGTRAP, reportme);
2693 #endif
2694 #ifdef SIGVTALRM
2695     (void) signal(SIGVTALRM, reportme);
2696 #endif
2697 #ifdef SIGXCPU
2698     (void) signal(SIGXCPU, reportme);
2699 #endif
2700 #ifdef SIGXFSZ
2701     (void) signal(SIGXFSZ, reportme);
2702 #endif
2703 
2704     /*
2705      * Open the record file if required.
2706      */
2707     if (record_file != NULL) {
2708 	recordf = fopen(record_file, "a");
2709 	if (recordf == NULL)
2710 	    error("Couldn't create record file %s: %m", record_file);
2711     }
2712 
2713     /* set all the fds to non-blocking mode */
2714     flags = fcntl(pty_master, F_GETFL);
2715     if (flags == -1
2716 	|| fcntl(pty_master, F_SETFL, flags | O_NONBLOCK) == -1)
2717 	warn("couldn't set pty master to nonblock: %m");
2718     flags = fcntl(ifd, F_GETFL);
2719     if (flags == -1
2720 	|| fcntl(ifd, F_SETFL, flags | O_NONBLOCK) == -1)
2721 	warn("couldn't set %s to nonblock: %m", (ifd==0? "stdin": "tty"));
2722     if (ofd != ifd) {
2723 	flags = fcntl(ofd, F_GETFL);
2724 	if (flags == -1
2725 	    || fcntl(ofd, F_SETFL, flags | O_NONBLOCK) == -1)
2726 	    warn("couldn't set stdout to nonblock: %m");
2727     }
2728 
2729     nibuf = nobuf = 0;
2730     ibufp = obufp = NULL;
2731 
2732     ilevel = olevel = 0;
2733     (void) gettimeofday(&levelt, NULL);
2734     if (max_data_rate) {
2735 	max_level = max_data_rate / 10;
2736 	if (max_level < MAXLEVELMINSIZE)
2737 	    max_level = MAXLEVELMINSIZE;
2738     } else
2739 	max_level = sizeof(inpacket_buf) + 1;
2740 
2741     nfds = (ofd > pty_master? ofd: pty_master) + 1;
2742     if (recordf != NULL) {
2743 	(void) gettimeofday(&lasttime, NULL);
2744 	(void) putc(RECMARK_TIMESTART, recordf);	/* put start marker */
2745 	(void) putc(lasttime.tv_sec >> 24, recordf);
2746 	(void) putc(lasttime.tv_sec >> 16, recordf);
2747 	(void) putc(lasttime.tv_sec >> 8, recordf);
2748 	(void) putc(lasttime.tv_sec, recordf);
2749 	lasttime.tv_usec = 0;
2750     }
2751 
2752     while (nibuf != 0 || nobuf != 0 || ofd >= 0 || pty_master >= 0) {
2753 	top = 0;
2754 	tout.tv_sec = 0;
2755 	tout.tv_usec = 10000;
2756 	FD_ZERO(&ready);
2757 	FD_ZERO(&writey);
2758 	if (nibuf != 0) {
2759 	    if (ilevel >= max_level)
2760 		top = &tout;
2761 	    else if (pty_master >= 0)
2762 		FD_SET(pty_master, &writey);
2763 	} else if (ifd >= 0)
2764 	    FD_SET(ifd, &ready);
2765 	if (nobuf != 0) {
2766 	    if (olevel >= max_level)
2767 		top = &tout;
2768 	    else if (ofd >= 0)
2769 		FD_SET(ofd, &writey);
2770 	} else {
2771 	    /* Don't read from pty if it's gone or it has closed. */
2772 	    if (pty_master >= 0 && ofd >= 0)
2773 		FD_SET(pty_master, &ready);
2774 	}
2775 	if (select(nfds, &ready, &writey, NULL, top) < 0) {
2776 	    if (errno != EINTR)
2777 		fatal("select");
2778 	    continue;
2779 	}
2780 	if (max_data_rate) {
2781 	    double dt;
2782 	    int nbt;
2783 	    struct timeval now;
2784 
2785 	    (void) gettimeofday(&now, NULL);
2786 	    dt = (now.tv_sec - levelt.tv_sec
2787 		  + (now.tv_usec - levelt.tv_usec) / 1e6);
2788 	    nbt = (int)(dt * max_data_rate);
2789 	    ilevel = (nbt < 0 || nbt > ilevel)? 0: ilevel - nbt;
2790 	    olevel = (nbt < 0 || nbt > olevel)? 0: olevel - nbt;
2791 	    levelt = now;
2792 	} else
2793 	    ilevel = olevel = 0;
2794 	if (FD_ISSET(ifd, &ready)) {
2795 	    ibufp = inpacket_buf;
2796 	    nibuf = read(ifd, ibufp, sizeof(inpacket_buf));
2797 	    if (nibuf < 0 && errno == EIO)
2798 		nibuf = 0;
2799 	    if (nibuf < 0 || pty_master == -1) {
2800 		if (errno != EINTR && errno != EAGAIN) {
2801 		    error("Error reading standard input: %m");
2802 		    break;
2803 		}
2804 		nibuf = 0;
2805 	    } else if (nibuf == 0) {
2806 		/* end of file from stdin */
2807 		(void) close(pty_master);
2808 		pty_master = -1;
2809 		(void) close(ifd);
2810 		ifd = -1;
2811 		if (recordf)
2812 		    if (!record_write(recordf, RECMARK_ENDRECV, NULL, 0,
2813 			&lasttime))
2814 			recordf = NULL;
2815 	    } else {
2816 		FD_SET(pty_master, &writey);
2817 		if (recordf)
2818 		    if (!record_write(recordf, RECMARK_STARTRECV, ibufp, nibuf,
2819 			&lasttime))
2820 			recordf = NULL;
2821 	    }
2822 	}
2823 	if (ofd >= 0 && pty_master >= 0 && FD_ISSET(pty_master, &ready)) {
2824 	    obufp = outpacket_buf;
2825 	    nobuf = read(pty_master, obufp, sizeof(outpacket_buf));
2826 	    if (nobuf < 0 && errno == EIO)
2827 		nobuf = 0;
2828 	    if (nobuf < 0 || ofd == -1) {
2829 		if (!(errno == EINTR || errno == EAGAIN)) {
2830 		    error("Error reading pseudo-tty master: %m");
2831 		    break;
2832 		}
2833 		nobuf = 0;
2834 	    } else if (nobuf == 0) {
2835 		/* end of file from the pty - slave side has closed */
2836 		nibuf = 0;
2837 		(void) close(ofd);
2838 		ofd = -1;
2839 		if (recordf)
2840 		    if (!record_write(recordf, RECMARK_ENDSEND, NULL, 0,
2841 			&lasttime))
2842 			recordf = NULL;
2843 	    } else {
2844 		FD_SET(ofd, &writey);
2845 		if (recordf)
2846 		    if (!record_write(recordf, RECMARK_STARTSEND, obufp, nobuf,
2847 			&lasttime))
2848 			recordf = NULL;
2849 	    }
2850 	}
2851 	if (ofd == -1)
2852 	    nobuf = 0;
2853 	else if (FD_ISSET(ofd, &writey)) {
2854 	    n = nobuf;
2855 	    if (olevel + n > max_level)
2856 		n = max_level - olevel;
2857 	    n = write(ofd, obufp, n);
2858 	    if (n < 0) {
2859 		if (errno == EIO) {
2860 		    (void) close(ofd);
2861 		    ofd = -1;
2862 		    nobuf = 0;
2863 		} else if (errno != EAGAIN && errno != EINTR) {
2864 		    error("Error writing standard output: %m");
2865 		    break;
2866 		}
2867 	    } else {
2868 		obufp += n;
2869 		nobuf -= n;
2870 		olevel += n;
2871 	    }
2872 	}
2873 	if (pty_master == -1)
2874 	    nibuf = 0;
2875 	else if (FD_ISSET(pty_master, &writey)) {
2876 	    n = nibuf;
2877 	    if (ilevel + n > max_level)
2878 		n = max_level - ilevel;
2879 	    n = write(pty_master, ibufp, n);
2880 	    if (n < 0) {
2881 		if (errno == EAGAIN || errno == EINTR)
2882 		    continue;
2883 		if (errno != EIO) {
2884 		    error("Error writing pseudo-tty master: %m");
2885 		    break;
2886 		}
2887 		(void) close(pty_master);
2888 		pty_master = -1;
2889 		nibuf = 0;
2890 	    } else {
2891 		ibufp += n;
2892 		nibuf -= n;
2893 		ilevel += n;
2894 	    }
2895 	}
2896     }
2897     exit(0);
2898 }
2899 
2900 static int
2901 record_write(f, code, buf, nb, tp)
2902     FILE *f;
2903     int code;
2904     u_char *buf;
2905     int nb;
2906     struct timeval *tp;
2907 {
2908     struct timeval now;
2909     int diff;
2910 
2911     (void) gettimeofday(&now, NULL);
2912     now.tv_usec /= 100000;	/* actually 1/10 s, not usec now */
2913     diff = (now.tv_sec - tp->tv_sec) * 10 + (now.tv_usec - tp->tv_usec);
2914     if (diff > 0) {
2915 	if (diff > 255) {
2916 	    (void) putc(RECMARK_TIMEDELTA32, f);
2917 	    (void) putc(diff >> 24, f);
2918 	    (void) putc(diff >> 16, f);
2919 	    (void) putc(diff >> 8, f);
2920 	    (void) putc(diff, f);
2921 	} else {
2922 	    (void) putc(RECMARK_TIMEDELTA8, f);
2923 	    (void) putc(diff, f);
2924 	}
2925 	*tp = now;
2926     }
2927     (void) putc(code, f);
2928     if (buf != NULL) {
2929 	(void) putc(nb >> 8, f);
2930 	(void) putc(nb, f);
2931 	(void) fwrite(buf, nb, 1, f);
2932     }
2933     (void) fflush(f);
2934     if (ferror(f)) {
2935 	error("Error writing record file: %m");
2936 	return (0);
2937     }
2938     return (1);
2939 }
2940