main.c revision 1.39 
1/*	$OpenBSD: main.c,v 1.39 2002/07/29 22:02:38 millert Exp $	*/
2
3/*
4 * main.c - Point-to-Point Protocol main module
5 *
6 * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in
17 *    the documentation and/or other materials provided with the
18 *    distribution.
19 *
20 * 3. The name "Carnegie Mellon University" must not be used to
21 *    endorse or promote products derived from this software without
22 *    prior written permission. For permission or any legal
23 *    details, please contact
24 *      Office of Technology Transfer
25 *      Carnegie Mellon University
26 *      5000 Forbes Avenue
27 *      Pittsburgh, PA  15213-3890
28 *      (412) 268-4387, fax: (412) 268-7395
29 *      tech-transfer@andrew.cmu.edu
30 *
31 * 4. Redistributions of any form whatsoever must retain the following
32 *    acknowledgment:
33 *    "This product includes software developed by Computing Services
34 *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
35 *
36 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
37 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
38 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
39 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
40 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
41 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
42 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
43 */
44
45#ifndef lint
46#if 0
47static char rcsid[] = "Id: main.c,v 1.49 1998/05/05 05:24:17 paulus Exp $";
48#else
49static char rcsid[] = "$OpenBSD: main.c,v 1.39 2002/07/29 22:02:38 millert Exp $";
50#endif
51#endif
52
53#include <stdio.h>
54#include <ctype.h>
55#include <stdlib.h>
56#include <string.h>
57#include <unistd.h>
58#include <signal.h>
59#include <errno.h>
60#include <fcntl.h>
61#include <syslog.h>
62#include <netdb.h>
63#include <utmp.h>
64#include <pwd.h>
65#include <sys/param.h>
66#include <sys/types.h>
67#include <sys/wait.h>
68#include <sys/time.h>
69#include <sys/resource.h>
70#include <sys/stat.h>
71#include <sys/socket.h>
72#include <net/if.h>
73
74#include "pppd.h"
75#include "magic.h"
76#include "fsm.h"
77#include "lcp.h"
78#include "ipcp.h"
79#include "upap.h"
80#include "chap.h"
81#include "ccp.h"
82#include "pathnames.h"
83#include "patchlevel.h"
84
85#ifdef CBCP_SUPPORT
86#include "cbcp.h"
87#endif
88
89#if defined(SUNOS4)
90extern char *strerror();
91#endif
92
93#ifdef IPX_CHANGE
94#include "ipxcp.h"
95#endif /* IPX_CHANGE */
96#ifdef AT_CHANGE
97#include "atcp.h"
98#endif
99
100/* interface vars */
101char ifname[IFNAMSIZ];		/* Interface name */
102int ifunit;			/* Interface unit number */
103
104char *progname;			/* Name of this program */
105char hostname[MAXHOSTNAMELEN];	/* Our hostname */
106static char pidfilename[MAXPATHLEN];	/* name of pid file */
107static char default_devnam[MAXPATHLEN];	/* name of default device */
108static pid_t pid;		/* Our pid */
109static uid_t uid;		/* Our real user-id */
110static int conn_running;	/* we have a [dis]connector running */
111static int crashed = 0;
112
113int ttyfd = -1;			/* Serial port file descriptor */
114mode_t tty_mode = -1;		/* Original access permissions to tty */
115int baud_rate;			/* Actual bits/second for serial device */
116int hungup;			/* terminal has been hung up */
117int privileged;			/* we're running as real uid root */
118int need_holdoff;		/* need holdoff period before restarting */
119int detached;			/* have detached from terminal */
120
121int phase;			/* where the link is at */
122int kill_link;
123int open_ccp_flag;
124
125char **script_env;		/* Env. variable values for scripts */
126int s_env_nalloc;		/* # words avail at script_env */
127
128u_char outpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for outgoing packet */
129u_char inpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for incoming packet */
130
131static int n_children;		/* # child processes still running */
132
133static int locked;		/* lock() has succeeded */
134
135char *no_ppp_msg = "Sorry - this system lacks PPP kernel support\n";
136
137/* Prototypes for procedures local to this file. */
138
139static void create_pidfile(void);
140static void cleanup(void);
141static void close_tty(void);
142static void get_input(void);
143static void calltimeout(void);
144static struct timeval *timeleft(struct timeval *);
145static void kill_my_pg(int);
146static void hup(int);
147static void term(int);
148static void chld(int);
149static void toggle_debug(int);
150static void open_ccp(int);
151static void bad_signal(int);
152static void holdoff_end(void *);
153static int device_script(char *, int, int);
154static void reap_kids(void);
155static void pr_log(void *, char *, ...);
156
157extern	char	*ttyname(int);
158extern	char	*getlogin(void);
159int main(int, char *[]);
160
161#ifdef ultrix
162#undef	O_NONBLOCK
163#define	O_NONBLOCK	O_NDELAY
164#endif
165
166#ifdef ULTRIX
167#define setlogmask(x)
168#endif
169
170/*
171 * PPP Data Link Layer "protocol" table.
172 * One entry per supported protocol.
173 * The last entry must be NULL.
174 */
175struct protent *protocols[] = {
176    &lcp_protent,
177    &pap_protent,
178    &chap_protent,
179#ifdef CBCP_SUPPORT
180    &cbcp_protent,
181#endif
182    &ipcp_protent,
183    &ccp_protent,
184#ifdef IPX_CHANGE
185    &ipxcp_protent,
186#endif
187#ifdef AT_CHANGE
188    &atcp_protent,
189#endif
190    NULL
191};
192
193int
194main(argc, argv)
195    int argc;
196    char *argv[];
197{
198    int i, fdflags;
199    struct sigaction sa;
200    char *p;
201    struct passwd *pw;
202    struct timeval timo;
203    sigset_t mask;
204    struct protent *protp;
205    struct stat statbuf;
206    char numbuf[16];
207
208    phase = PHASE_INITIALIZE;
209    p = ttyname(0);
210    if (p)
211	strcpy(devnam, p);
212    strcpy(default_devnam, devnam);
213
214    script_env = NULL;
215
216    /* Initialize syslog facilities */
217#ifdef ULTRIX
218    openlog("pppd", LOG_PID);
219#else
220    openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
221    setlogmask(LOG_UPTO(LOG_INFO));
222#endif
223
224    if (gethostname(hostname, sizeof hostname) < 0 ) {
225	option_error("Couldn't get hostname: %m");
226	die(1);
227    }
228
229    uid = getuid();
230    privileged = uid == 0;
231    sprintf(numbuf, "%u", uid);
232    script_setenv("UID", numbuf);
233
234    /*
235     * Initialize to the standard option set, then parse, in order,
236     * the system options file, the user's options file,
237     * the tty's options file, and the command line arguments.
238     */
239    for (i = 0; (protp = protocols[i]) != NULL; ++i)
240	(*protp->init)(0);
241
242    progname = *argv;
243
244    if (!options_from_file(_PATH_SYSOPTIONS, !privileged, 0, 1)
245	|| !options_from_user())
246	exit(1);
247    scan_args(argc-1, argv+1);	/* look for tty name on command line */
248    if (!options_for_tty()
249	|| !parse_args(argc-1, argv+1))
250	exit(1);
251
252    /*
253     * Check that we are running as root.
254     */
255    if (geteuid() != 0) {
256	option_error("must be root to run %s, since it is not setuid-root",
257		     argv[0]);
258	die(1);
259    }
260
261    if (!ppp_available()) {
262	option_error(no_ppp_msg);
263	exit(1);
264    }
265
266    /*
267     * Check that the options given are valid and consistent.
268     */
269    sys_check_options();
270    auth_check_options();
271    for (i = 0; (protp = protocols[i]) != NULL; ++i)
272	if (protp->check_options != NULL)
273	    (*protp->check_options)();
274    if (demand && connector == 0) {
275	option_error("connect script required for demand-dialling\n");
276	exit(1);
277    }
278
279    script_setenv("DEVICE", devnam);
280    sprintf(numbuf, "%d", baud_rate);
281    script_setenv("SPEED", numbuf);
282
283    /*
284     * If the user has specified the default device name explicitly,
285     * pretend they hadn't.
286     */
287    if (!default_device && strcmp(devnam, default_devnam) == 0)
288	default_device = 1;
289    if (default_device)
290	nodetach = 1;
291
292    /*
293     * Initialize system-dependent stuff and magic number package.
294     */
295    sys_init();
296    magic_init();
297    if (debug)
298	setlogmask(LOG_UPTO(LOG_DEBUG));
299
300    /*
301     * Detach ourselves from the terminal, if required,
302     * and identify who is running us.
303     */
304    if (nodetach == 0)
305	detach();
306    pid = getpid();
307    p = getlogin();
308    if (p == NULL) {
309	pw = getpwuid(uid);
310	if (pw != NULL && pw->pw_name != NULL)
311	    p = pw->pw_name;
312	else
313	    p = "(unknown)";
314    }
315    syslog(LOG_NOTICE, "pppd %s.%d%s started by %s, uid %u",
316	   VERSION, PATCHLEVEL, IMPLEMENTATION, p, uid);
317
318    /*
319     * Compute mask of all interesting signals and install signal handlers
320     * for each.  Only one signal handler may be active at a time.  Therefore,
321     * all other signals should be masked when any handler is executing.
322     */
323    sigemptyset(&mask);
324    sigaddset(&mask, SIGHUP);
325    sigaddset(&mask, SIGINT);
326    sigaddset(&mask, SIGTERM);
327    sigaddset(&mask, SIGCHLD);
328
329#define SIGNAL(s, handler)	{ \
330	sa.sa_handler = handler; \
331	if (sigaction(s, &sa, NULL) < 0) { \
332	    syslog(LOG_ERR, "Couldn't establish signal handler (%d): %m", s); \
333	    die(1); \
334	} \
335    }
336
337    sa.sa_mask = mask;
338    sa.sa_flags = 0;
339    SIGNAL(SIGHUP, hup);		/* Hangup */
340    SIGNAL(SIGINT, term);		/* Interrupt */
341    SIGNAL(SIGTERM, term);		/* Terminate */
342    SIGNAL(SIGCHLD, chld);
343
344    SIGNAL(SIGUSR1, toggle_debug);	/* Toggle debug flag */
345    SIGNAL(SIGUSR2, open_ccp);		/* Reopen CCP */
346
347    /*
348     * Install a handler for other signals which would otherwise
349     * cause pppd to exit without cleaning up.
350     */
351    SIGNAL(SIGABRT, bad_signal);
352    SIGNAL(SIGALRM, bad_signal);
353    SIGNAL(SIGFPE, bad_signal);
354    SIGNAL(SIGILL, bad_signal);
355    SIGNAL(SIGPIPE, bad_signal);
356    SIGNAL(SIGQUIT, bad_signal);
357#if SIGSEGV_CHECK
358    SIGNAL(SIGSEGV, bad_signal);
359#endif
360#ifdef SIGBUS
361    SIGNAL(SIGBUS, bad_signal);
362#endif
363#ifdef SIGEMT
364    SIGNAL(SIGEMT, bad_signal);
365#endif
366#ifdef SIGPOLL
367    SIGNAL(SIGPOLL, bad_signal);
368#endif
369#ifdef SIGPROF
370    SIGNAL(SIGPROF, bad_signal);
371#endif
372#ifdef SIGSYS
373    SIGNAL(SIGSYS, bad_signal);
374#endif
375#ifdef SIGTRAP
376    SIGNAL(SIGTRAP, bad_signal);
377#endif
378#ifdef SIGVTALRM
379    SIGNAL(SIGVTALRM, bad_signal);
380#endif
381#ifdef SIGXCPU
382    SIGNAL(SIGXCPU, bad_signal);
383#endif
384#ifdef SIGXFSZ
385    SIGNAL(SIGXFSZ, bad_signal);
386#endif
387
388    /*
389     * Apparently we can get a SIGPIPE when we call syslog, if
390     * syslogd has died and been restarted.  Ignoring it seems
391     * be sufficient.
392     */
393    signal(SIGPIPE, SIG_IGN);
394
395    /*
396     * If we're doing dial-on-demand, set up the interface now.
397     */
398    if (demand) {
399	/*
400	 * Open the loopback channel and set it up to be the ppp interface.
401	 */
402	open_ppp_loopback();
403
404	syslog(LOG_INFO, "Using interface ppp%d", ifunit);
405	(void) sprintf(ifname, "ppp%d", ifunit);
406	script_setenv("IFNAME", ifname);
407
408	create_pidfile();	/* write pid to file */
409
410	/*
411	 * Configure the interface and mark it up, etc.
412	 */
413	demand_conf();
414    }
415
416    for (;;) {
417
418	need_holdoff = 1;
419
420	if (demand) {
421	    /*
422	     * Don't do anything until we see some activity.
423	     */
424	    phase = PHASE_DORMANT;
425	    kill_link = 0;
426	    demand_unblock();
427	    for (;;) {
428		wait_loop_output(timeleft(&timo));
429		calltimeout();
430		if (kill_link) {
431		    if (!persist)
432			die(0);
433		    kill_link = 0;
434		}
435		if (get_loop_output())
436		    break;
437		reap_kids();
438	    }
439
440	    /*
441	     * Now we want to bring up the link.
442	     */
443	    demand_drop();
444	    syslog(LOG_INFO, "Starting link");
445	}
446
447	/*
448	 * Lock the device if we've been asked to.
449	 */
450	if (lockflag && !default_device) {
451	    if (lock(devnam) < 0)
452		goto fail;
453	    locked = 1;
454	}
455
456	/*
457	 * Open the serial device and set it up to be the ppp interface.
458	 * First we open it in non-blocking mode so we can set the
459	 * various termios flags appropriately.  If we aren't dialling
460	 * out and we want to use the modem lines, we reopen it later
461	 * in order to wait for the carrier detect signal from the modem.
462	 */
463	while ((ttyfd = open(devnam, O_NONBLOCK | O_RDWR, 0)) < 0) {
464	    if (errno != EINTR)
465		syslog(LOG_ERR, "Failed to open %s: %m", devnam);
466	    if (!persist || errno != EINTR)
467		goto fail;
468	}
469	if ((fdflags = fcntl(ttyfd, F_GETFL)) == -1
470	    || fcntl(ttyfd, F_SETFL, fdflags & ~O_NONBLOCK) < 0)
471	    syslog(LOG_WARNING,
472		   "Couldn't reset non-blocking mode on device: %m");
473
474	hungup = 0;
475	kill_link = 0;
476
477	/*
478	 * Do the equivalent of `mesg n' to stop broadcast messages.
479	 */
480	if (fstat(ttyfd, &statbuf) < 0
481	    || fchmod(ttyfd, statbuf.st_mode & ~(S_IWGRP | S_IWOTH)) < 0) {
482	    syslog(LOG_WARNING,
483		   "Couldn't restrict write permissions to %s: %m", devnam);
484	} else
485	    tty_mode = statbuf.st_mode;
486
487	/* run connection script */
488	if (connector && connector[0]) {
489	    MAINDEBUG((LOG_INFO, "Connecting with <%s>", connector));
490
491	    /*
492	     * Set line speed, flow control, etc.
493	     * On most systems we set CLOCAL for now so that we can talk
494	     * to the modem before carrier comes up.  But this has the
495	     * side effect that we might miss it if CD drops before we
496	     * get to clear CLOCAL below.  On systems where we can talk
497	     * successfully to the modem with CLOCAL clear and CD down,
498	     * we can clear CLOCAL at this point.
499	     */
500	    set_up_tty(ttyfd, (modem_chat == 0));
501
502	    /* drop dtr to hang up in case modem is off hook */
503	    if (!default_device && modem) {
504		setdtr(ttyfd, FALSE);
505		sleep(1);
506		setdtr(ttyfd, TRUE);
507	    }
508
509	    if (device_script(connector, ttyfd, ttyfd) < 0) {
510		syslog(LOG_ERR, "Connect script failed");
511		setdtr(ttyfd, FALSE);
512		goto fail;
513	    }
514
515	    syslog(LOG_INFO, "Serial connection established.");
516	    sleep(1);		/* give it time to set up its terminal */
517	}
518
519	set_up_tty(ttyfd, 0);
520
521	/* reopen tty if necessary to wait for carrier */
522	if (connector == NULL && modem) {
523	    while ((i = open(devnam, O_RDWR)) < 0) {
524		if (errno != EINTR)
525		    syslog(LOG_ERR, "Failed to reopen %s: %m", devnam);
526		if (!persist || errno != EINTR || hungup || kill_link)
527		    goto fail;
528	    }
529	    close(i);
530	}
531
532	/* run welcome script, if any */
533	if (welcomer && welcomer[0]) {
534	    if (device_script(welcomer, ttyfd, ttyfd) < 0)
535		syslog(LOG_WARNING, "Welcome script failed");
536	}
537
538	/* set up the serial device as a ppp interface */
539	establish_ppp(ttyfd);
540
541	if (!demand) {
542
543	    syslog(LOG_INFO, "Using interface ppp%d", ifunit);
544	    (void) sprintf(ifname, "ppp%d", ifunit);
545	    script_setenv("IFNAME", ifname);
546
547	    create_pidfile();	/* write pid to file */
548	}
549
550	/*
551	 * Start opening the connection and wait for
552	 * incoming events (reply, timeout, etc.).
553	 */
554	syslog(LOG_NOTICE, "Connect: %s <--> %s", ifname, devnam);
555	lcp_lowerup(0);
556	lcp_open(0);		/* Start protocol */
557	for (phase = PHASE_ESTABLISH; phase != PHASE_DEAD; ) {
558	    wait_input(timeleft(&timo));
559	    calltimeout();
560	    get_input();
561	    if (kill_link) {
562		lcp_close(0, "User request");
563		kill_link = 0;
564	    }
565	    if (open_ccp_flag) {
566		if (phase == PHASE_NETWORK) {
567		    ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */
568		    (*ccp_protent.open)(0);
569		}
570		open_ccp_flag = 0;
571	    }
572	    reap_kids();	/* Don't leave dead kids lying around */
573	}
574
575	/*
576	 * If we may want to bring the link up again, transfer
577	 * the ppp unit back to the loopback.  Set the
578	 * real serial device back to its normal mode of operation.
579	 */
580	clean_check();
581	if (demand)
582	    restore_loop();
583	disestablish_ppp(ttyfd);
584
585	/*
586	 * Run disconnector script, if requested.
587	 * XXX we may not be able to do this if the line has hung up!
588	 */
589	if (disconnector && !hungup) {
590	    set_up_tty(ttyfd, 1);
591	    if (device_script(disconnector, ttyfd, ttyfd) < 0) {
592		syslog(LOG_WARNING, "disconnect script failed");
593	    } else {
594		syslog(LOG_INFO, "Serial link disconnected.");
595	    }
596	}
597
598    fail:
599	if (ttyfd >= 0)
600	    close_tty();
601	if (locked) {
602	    unlock();
603	    locked = 0;
604	}
605
606	if (!demand) {
607	    if (pidfilename[0] != 0
608		&& unlink(pidfilename) < 0 && errno != ENOENT)
609		syslog(LOG_WARNING, "unable to delete pid file: %m");
610	    pidfilename[0] = 0;
611	}
612
613	if (!persist)
614	    die(1);
615
616	if (holdoff > 0 && need_holdoff) {
617	    phase = PHASE_HOLDOFF;
618	    TIMEOUT(holdoff_end, NULL, holdoff);
619	    do {
620		wait_time(timeleft(&timo));
621		calltimeout();
622		if (kill_link) {
623		    if (!persist)
624			die(0);
625		    kill_link = 0;
626		    phase = PHASE_DORMANT; /* allow signal to end holdoff */
627		}
628		reap_kids();
629	    } while (phase == PHASE_HOLDOFF);
630	}
631    }
632
633    die(0);
634    return 0;
635}
636
637/*
638 * detach - detach us from the controlling terminal.
639 */
640void
641detach()
642{
643    if (detached)
644	return;
645    if (daemon(0, 0) < 0) {
646	perror("Couldn't detach from controlling terminal");
647	die(1);
648    }
649    detached = 1;
650    pid = getpid();
651    /* update pid file if it has been written already */
652    if (pidfilename[0])
653	create_pidfile();
654}
655
656/*
657 * Create a file containing our process ID.
658 */
659static void
660create_pidfile()
661{
662    FILE *pidfile;
663
664    (void) sprintf(pidfilename, "%s%s.pid", _PATH_VARRUN, ifname);
665    if ((pidfile = fopen(pidfilename, "w")) != NULL) {
666	fprintf(pidfile, "%ld\n", (long)pid);
667	(void) fclose(pidfile);
668    } else {
669	syslog(LOG_ERR, "Failed to create pid file %s: %m", pidfilename);
670	pidfilename[0] = 0;
671    }
672}
673
674/*
675 * holdoff_end - called via a timeout when the holdoff period ends.
676 */
677static void
678holdoff_end(arg)
679    void *arg;
680{
681    phase = PHASE_DORMANT;
682}
683
684/*
685 * get_input - called when incoming data is available.
686 */
687static void
688get_input()
689{
690    int len, i;
691    u_char *p;
692    u_short protocol;
693    struct protent *protp;
694
695    p = inpacket_buf;	/* point to beginning of packet buffer */
696
697    len = read_packet(inpacket_buf);
698    if (len < 0)
699	return;
700
701    if (len == 0) {
702	syslog(LOG_NOTICE, "Modem hangup");
703	hungup = 1;
704	lcp_lowerdown(0);	/* serial link is no longer available */
705	link_terminated(0);
706	return;
707    }
708
709    if (debug /*&& (debugflags & DBG_INPACKET)*/)
710	log_packet(p, len, "rcvd ", LOG_DEBUG);
711
712    if (len < PPP_HDRLEN) {
713	MAINDEBUG((LOG_INFO, "io(): Received short packet."));
714	return;
715    }
716
717    p += 2;				/* Skip address and control */
718    GETSHORT(protocol, p);
719    len -= PPP_HDRLEN;
720
721    /*
722     * Toss all non-LCP packets unless LCP is OPEN.
723     */
724    if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) {
725	MAINDEBUG((LOG_INFO,
726		   "get_input: Received non-LCP packet when LCP not open."));
727	return;
728    }
729
730    /*
731     * Until we get past the authentication phase, toss all packets
732     * except LCP, LQR and authentication packets.
733     */
734    if (phase <= PHASE_AUTHENTICATE
735	&& !(protocol == PPP_LCP || protocol == PPP_LQR
736	|| protocol == PPP_PAP || protocol == PPP_CHAP)) {
737	MAINDEBUG((LOG_INFO, "get_input: discarding proto 0x%x in phase %d",
738		   protocol, phase));
739	return;
740    }
741
742    /*
743     * Upcall the proper protocol input routine.
744     */
745    for (i = 0; (protp = protocols[i]) != NULL; ++i) {
746	if (protp->protocol == protocol && protp->enabled_flag) {
747	    (*protp->input)(0, p, len);
748	    return;
749	}
750	if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
751	    && protp->datainput != NULL) {
752	    (*protp->datainput)(0, p, len);
753	    return;
754	}
755    }
756
757    if (debug)
758    	syslog(LOG_WARNING, "Unsupported protocol (0x%x) received", protocol);
759    lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
760}
761
762
763/*
764 * quit - Clean up state and exit (with an error indication).
765 */
766void
767quit()
768{
769    die(1);
770}
771
772/*
773 * die - like quit, except we can specify an exit status.
774 */
775void
776die(status)
777    int status;
778{
779    struct syslog_data sdata = SYSLOG_DATA_INIT;
780
781    cleanup();
782    syslog_r(LOG_INFO, &sdata, "Exit.");
783    _exit(status);
784}
785
786/*
787 * cleanup - restore anything which needs to be restored before we exit
788 */
789/* ARGSUSED */
790static void
791cleanup()
792{
793    sys_cleanup();
794
795    if (ttyfd >= 0)
796	close_tty();
797
798    if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT)
799	syslog(LOG_WARNING, "unable to delete pid file: %m");
800    pidfilename[0] = 0;
801
802    if (locked)
803	unlock();
804}
805
806/*
807 * close_tty - restore the terminal device and close it.
808 */
809static void
810close_tty()
811{
812    disestablish_ppp(ttyfd);
813
814    /* drop dtr to hang up */
815    if (modem) {
816	setdtr(ttyfd, FALSE);
817	/*
818	 * This sleep is in case the serial port has CLOCAL set by default,
819	 * and consequently will reassert DTR when we close the device.
820	 */
821	sleep(1);
822    }
823
824    restore_tty(ttyfd);
825
826    if (tty_mode != (mode_t) -1)
827	fchmod(ttyfd, tty_mode);
828
829    close(ttyfd);
830    ttyfd = -1;
831}
832
833
834struct	callout {
835    struct timeval	c_time;		/* time at which to call routine */
836    void		*c_arg;		/* argument to routine */
837    void		(*c_func)(void *); /* routine */
838    struct		callout *c_next;
839};
840
841static struct callout *callout = NULL;	/* Callout list */
842static struct timeval timenow;		/* Current time */
843
844/*
845 * timeout - Schedule a timeout.
846 *
847 * Note that this timeout takes the number of seconds, NOT hz (as in
848 * the kernel).
849 */
850void
851timeout(func, arg, time)
852    void (*func)(void *);
853    void *arg;
854    int time;
855{
856    struct callout *newp, *p, **pp;
857
858    MAINDEBUG((LOG_DEBUG, "Timeout %lx:%lx in %d seconds.",
859	       (long) func, (long) arg, time));
860
861    /*
862     * Allocate timeout.
863     */
864    if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL) {
865	syslog(LOG_ERR, "Out of memory in timeout()!");
866	die(1);
867    }
868    newp->c_arg = arg;
869    newp->c_func = func;
870    gettimeofday(&timenow, NULL);
871    newp->c_time.tv_sec = timenow.tv_sec + time;
872    newp->c_time.tv_usec = timenow.tv_usec;
873
874    /*
875     * Find correct place and link it in.
876     */
877    for (pp = &callout; (p = *pp); pp = &p->c_next)
878	if (newp->c_time.tv_sec < p->c_time.tv_sec
879	    || (newp->c_time.tv_sec == p->c_time.tv_sec
880		&& newp->c_time.tv_usec < p->c_time.tv_sec))
881	    break;
882    newp->c_next = p;
883    *pp = newp;
884}
885
886
887/*
888 * untimeout - Unschedule a timeout.
889 */
890void
891untimeout(func, arg)
892    void (*func)(void *);
893    void *arg;
894{
895    struct callout **copp, *freep;
896
897    MAINDEBUG((LOG_DEBUG, "Untimeout %lx:%lx.", (long) func, (long) arg));
898
899    /*
900     * Find first matching timeout and remove it from the list.
901     */
902    for (copp = &callout; (freep = *copp); copp = &freep->c_next)
903	if (freep->c_func == func && freep->c_arg == arg) {
904	    *copp = freep->c_next;
905	    (void) free((char *) freep);
906	    break;
907	}
908}
909
910
911/*
912 * calltimeout - Call any timeout routines which are now due.
913 */
914static void
915calltimeout()
916{
917    struct callout *p;
918
919    while (callout != NULL) {
920	p = callout;
921
922	if (gettimeofday(&timenow, NULL) < 0) {
923	    syslog(LOG_ERR, "Failed to get time of day: %m");
924	    die(1);
925	}
926	if (!(p->c_time.tv_sec < timenow.tv_sec
927	      || (p->c_time.tv_sec == timenow.tv_sec
928		  && p->c_time.tv_usec <= timenow.tv_usec)))
929	    break;		/* no, it's not time yet */
930
931	callout = p->c_next;
932	(*p->c_func)(p->c_arg);
933
934	free((char *) p);
935    }
936}
937
938
939/*
940 * timeleft - return the length of time until the next timeout is due.
941 */
942static struct timeval *
943timeleft(tvp)
944    struct timeval *tvp;
945{
946    if (callout == NULL)
947	return NULL;
948
949    gettimeofday(&timenow, NULL);
950    tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
951    tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
952    if (tvp->tv_usec < 0) {
953	tvp->tv_usec += 1000000;
954	tvp->tv_sec -= 1;
955    }
956    if (tvp->tv_sec < 0)
957	tvp->tv_sec = tvp->tv_usec = 0;
958
959    return tvp;
960}
961
962
963/*
964 * kill_my_pg - send a signal to our process group, and ignore it ourselves.
965 */
966static void
967kill_my_pg(sig)
968    int sig;
969{
970    struct sigaction act, oldact;
971
972    act.sa_handler = SIG_IGN;
973    act.sa_flags = 0;
974    kill(0, sig);
975    sigaction(sig, &act, &oldact);
976    sigaction(sig, &oldact, NULL);
977}
978
979
980/*
981 * hup - Catch SIGHUP signal.
982 *
983 * Indicates that the physical layer has been disconnected.
984 * We don't rely on this indication; if the user has sent this
985 * signal, we just take the link down.
986 */
987static void
988hup(sig)
989    int sig;
990{
991    int save_errno = errno;
992    struct syslog_data sdata = SYSLOG_DATA_INIT;
993
994    if (crashed)
995	_exit(127);
996    syslog_r(LOG_INFO, &sdata, "Hangup (SIGHUP)");
997    kill_link = 1;
998    if (conn_running)
999	/* Send the signal to the [dis]connector process(es) also */
1000	kill_my_pg(sig);
1001    errno = save_errno;
1002}
1003
1004
1005/*
1006 * term - Catch SIGTERM signal and SIGINT signal (^C/del).
1007 *
1008 * Indicates that we should initiate a graceful disconnect and exit.
1009 */
1010/*ARGSUSED*/
1011static void
1012term(sig)
1013    int sig;
1014{
1015    int save_errno = errno;
1016    struct syslog_data sdata = SYSLOG_DATA_INIT;
1017
1018    if (crashed)
1019	_exit(127);
1020    syslog_r(LOG_INFO, &sdata, "Terminating on signal %d.", sig);
1021    persist = 0;		/* don't try to restart */
1022    kill_link = 1;
1023    if (conn_running)
1024	/* Send the signal to the [dis]connector process(es) also */
1025	kill_my_pg(sig);
1026    errno = save_errno;
1027}
1028
1029
1030/*
1031 * chld - Catch SIGCHLD signal.
1032 * Calls reap_kids to get status for any dead kids.
1033 */
1034static void
1035chld(sig)
1036    int sig;
1037{
1038    int save_errno = errno;
1039
1040    reap_kids();		/* XXX somewhat unsafe */
1041    errno = save_errno;
1042}
1043
1044
1045/*
1046 * toggle_debug - Catch SIGUSR1 signal.
1047 *
1048 * Toggle debug flag.
1049 */
1050/*ARGSUSED*/
1051static void
1052toggle_debug(sig)
1053    int sig;
1054{
1055    debug = !debug;
1056    if (debug) {
1057	setlogmask(LOG_UPTO(LOG_DEBUG));	/* XXX safe, but wrong */
1058    } else {
1059	setlogmask(LOG_UPTO(LOG_WARNING));	/* XXX safe, but wrong */
1060    }
1061}
1062
1063
1064/*
1065 * open_ccp - Catch SIGUSR2 signal.
1066 *
1067 * Try to (re)negotiate compression.
1068 */
1069/*ARGSUSED*/
1070static void
1071open_ccp(sig)
1072    int sig;
1073{
1074    open_ccp_flag = 1;
1075}
1076
1077
1078/*
1079 * bad_signal - We've caught a fatal signal.  Clean up state and exit.
1080 */
1081static void
1082bad_signal(sig)
1083    int sig;
1084{
1085    struct syslog_data sdata = SYSLOG_DATA_INIT;
1086
1087    if (crashed)
1088	_exit(127);
1089    crashed = 1;
1090    syslog_r(LOG_ERR, &sdata, "Fatal signal %d", sig);
1091    if (conn_running)
1092	kill_my_pg(SIGTERM);
1093    die(1);					/* XXX unsafe! */
1094}
1095
1096
1097/*
1098 * device_script - run a program to connect or disconnect the
1099 * serial device.
1100 */
1101static int
1102device_script(program, in, out)
1103    char *program;
1104    int in, out;
1105{
1106    pid_t pid;
1107    int status;
1108    int errfd;
1109
1110    conn_running = 1;
1111    pid = fork();
1112
1113    if (pid < 0) {
1114	conn_running = 0;
1115	syslog(LOG_ERR, "Failed to create child process: %m");
1116	die(1);
1117    }
1118
1119    if (pid == 0) {
1120	sys_close();
1121	closelog();
1122	if (in == out) {
1123	    if (in != 0) {
1124		dup2(in, 0);
1125		close(in);
1126	    }
1127	    dup2(0, 1);
1128	} else {
1129	    if (out == 0)
1130		out = dup(out);
1131	    if (in != 0) {
1132		dup2(in, 0);
1133		close(in);
1134	    }
1135	    if (out != 1) {
1136		dup2(out, 1);
1137		close(out);
1138	    }
1139	}
1140	if (nodetach == 0) {
1141	    close(2);
1142	    errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0600);
1143	    if (errfd >= 0 && errfd != 2) {
1144		dup2(errfd, 2);
1145		close(errfd);
1146	    }
1147	}
1148	/* revoke privs */
1149	seteuid(getuid());
1150	setuid(getuid());
1151	setegid(getgid());
1152	setgid(getgid());
1153	execl("/bin/sh", "sh", "-c", program, (char *)0);
1154	syslog(LOG_ERR, "could not exec /bin/sh: %m");
1155	_exit(99);
1156	/* NOTREACHED */
1157    }
1158
1159    while (waitpid(pid, &status, 0) < 0) {
1160	if (errno == EINTR)
1161	    continue;
1162	syslog(LOG_ERR, "error waiting for (dis)connection process: %m");
1163	die(1);
1164    }
1165    conn_running = 0;
1166
1167    return (status == 0 ? 0 : -1);
1168}
1169
1170
1171/*
1172 * run-program - execute a program with given arguments,
1173 * but don't wait for it.
1174 * If the program can't be executed, logs an error unless
1175 * must_exist is 0 and the program file doesn't exist.
1176 */
1177int
1178run_program(prog, args, must_exist)
1179    char *prog;
1180    char **args;
1181    int must_exist;
1182{
1183    pid_t pid;
1184
1185    pid = fork();
1186    if (pid == -1) {
1187	syslog(LOG_ERR, "Failed to create child process for %s: %m", prog);
1188	return -1;
1189    }
1190    if (pid == 0) {
1191	int new_fd;
1192
1193	/* Leave the current location */
1194	(void) setsid();    /* No controlling tty. */
1195	(void) umask (S_IRWXG|S_IRWXO);
1196	(void) chdir ("/"); /* no current directory. */
1197	setuid(geteuid());
1198	setgid(getegid());
1199
1200	/* Ensure that nothing of our device environment is inherited. */
1201	sys_close();
1202	closelog();
1203	close (0);
1204	close (1);
1205	close (2);
1206	close (ttyfd);  /* tty interface to the ppp device */
1207
1208	/* Don't pass handles to the PPP device, even by accident. */
1209	new_fd = open (_PATH_DEVNULL, O_RDWR);
1210	if (new_fd >= 0) {
1211	    if (new_fd != 0) {
1212		dup2  (new_fd, 0); /* stdin <- /dev/null */
1213		close (new_fd);
1214	    }
1215	    dup2 (0, 1); /* stdout -> /dev/null */
1216	    dup2 (0, 2); /* stderr -> /dev/null */
1217	}
1218
1219#ifdef BSD
1220	/* Force the priority back to zero if pppd is running higher. */
1221	if (setpriority (PRIO_PROCESS, 0, 0) < 0)
1222	    syslog (LOG_WARNING, "can't reset priority to 0: %m");
1223#endif
1224
1225	/* SysV recommends a second fork at this point. */
1226
1227	/* run the program; give it a null environment */
1228	execve(prog, args, script_env);
1229	if (must_exist || errno != ENOENT)
1230	    syslog(LOG_WARNING, "Can't execute %s: %m", prog);
1231	_exit(1);
1232    }
1233    MAINDEBUG((LOG_DEBUG, "Script %s started; pid = %ld", prog, (long)pid));
1234    ++n_children;
1235    return 0;
1236}
1237
1238
1239/*
1240 * reap_kids - get status from any dead child processes,
1241 * and log a message for abnormal terminations.
1242 */
1243static void
1244reap_kids()
1245{
1246    int status;
1247    pid_t pid;
1248
1249    if (n_children == 0)
1250	return;
1251    if ((pid = waitpid(-1, &status, WNOHANG)) == -1) {
1252	if (errno != ECHILD)
1253	    syslog(LOG_ERR, "Error waiting for child process: %m");
1254	return;
1255    }
1256    if (pid > 0) {
1257	--n_children;
1258	if (WIFSIGNALED(status)) {
1259	    syslog(LOG_WARNING, "Child process %ld terminated with signal %d",
1260		   (long)pid, WTERMSIG(status));
1261	}
1262    }
1263}
1264
1265
1266/*
1267 * log_packet - format a packet and log it.
1268 */
1269
1270char line[256];			/* line to be logged accumulated here */
1271char *linep;
1272
1273void
1274log_packet(p, len, prefix, level)
1275    u_char *p;
1276    int len;
1277    char *prefix;
1278    int level;
1279{
1280    strcpy(line, prefix);
1281    linep = line + strlen(line);
1282    format_packet(p, len, pr_log, NULL);
1283    if (linep != line)
1284	syslog(level, "%s", line);
1285}
1286
1287/*
1288 * format_packet - make a readable representation of a packet,
1289 * calling `printer(arg, format, ...)' to output it.
1290 */
1291void
1292format_packet(p, len, printer, arg)
1293    u_char *p;
1294    int len;
1295    void (*printer)(void *, char *, ...);
1296    void *arg;
1297{
1298    int i, n;
1299    u_short proto;
1300    u_char x;
1301    struct protent *protp;
1302
1303    if (len >= PPP_HDRLEN && p[0] == PPP_ALLSTATIONS && p[1] == PPP_UI) {
1304	p += 2;
1305	GETSHORT(proto, p);
1306	len -= PPP_HDRLEN;
1307	for (i = 0; (protp = protocols[i]) != NULL; ++i)
1308	    if (proto == protp->protocol)
1309		break;
1310	if (protp != NULL) {
1311	    printer(arg, "[%s", protp->name);
1312	    n = (*protp->printpkt)(p, len, printer, arg);
1313	    printer(arg, "]");
1314	    p += n;
1315	    len -= n;
1316	} else {
1317	    printer(arg, "[proto=0x%x]", proto);
1318	}
1319    }
1320
1321    for (; len > 0; --len) {
1322	GETCHAR(x, p);
1323	printer(arg, " %.2x", x);
1324    }
1325}
1326
1327static void
1328pr_log(void *arg, char *fmt, ...)
1329{
1330    int n;
1331    va_list pvar;
1332    char buf[256];
1333
1334    va_start(pvar, fmt);
1335
1336    n = vfmtmsg(buf, sizeof(buf), fmt, pvar);
1337    va_end(pvar);
1338
1339    if (linep + n + 1 > line + sizeof(line)) {
1340	syslog(LOG_DEBUG, "%s", line);
1341	linep = line;
1342    }
1343    strcpy(linep, buf);
1344    linep += n;
1345}
1346
1347/*
1348 * print_string - print a readable representation of a string using
1349 * printer.
1350 */
1351void
1352print_string(p, len, printer, arg)
1353    char *p;
1354    int len;
1355    void (*printer)(void *, char *, ...);
1356    void *arg;
1357{
1358    int c;
1359
1360    printer(arg, "\"");
1361    for (; len > 0; --len) {
1362	c = *p++;
1363	if (' ' <= c && c <= '~') {
1364	    if (c == '\\' || c == '"')
1365		printer(arg, "\\");
1366	    printer(arg, "%c", c);
1367	} else {
1368	    switch (c) {
1369	    case '\n':
1370		printer(arg, "\\n");
1371		break;
1372	    case '\r':
1373		printer(arg, "\\r");
1374		break;
1375	    case '\t':
1376		printer(arg, "\\t");
1377		break;
1378	    default:
1379		printer(arg, "\\%.3o", c);
1380	    }
1381	}
1382    }
1383    printer(arg, "\"");
1384}
1385
1386/*
1387 * novm - log an error message saying we ran out of memory, and die.
1388 */
1389void
1390novm(msg)
1391    char *msg;
1392{
1393    syslog(LOG_ERR, "Virtual memory exhausted allocating %s", msg);
1394    die(1);
1395}
1396
1397/*
1398 * fmtmsg - format a message into a buffer.  Like sprintf except we
1399 * also specify the length of the output buffer, and we handle
1400 * %r (recursive format), %m (error message) and %I (IP address) formats.
1401 * Doesn't do floating-point formats.
1402 * Returns the number of chars put into buf.
1403 */
1404int
1405fmtmsg(char *buf, int buflen, char *fmt, ...)
1406{
1407    va_list args;
1408    int n;
1409
1410    va_start(args, fmt);
1411    n = vfmtmsg(buf, buflen, fmt, args);
1412    va_end(args);
1413    return n;
1414}
1415
1416/*
1417 * vfmtmsg - like fmtmsg, takes a va_list instead of a list of args.
1418 */
1419#define OUTCHAR(c)	(buflen > 0? (--buflen, *buf++ = (c)): 0)
1420
1421int
1422vfmtmsg(buf, buflen, fmt, args)
1423    char *buf;
1424    int buflen;
1425    char *fmt;
1426    va_list args;
1427{
1428    int c, i, n;
1429    int width, prec, fillch;
1430    int base, len, neg, quoted;
1431    unsigned long val = 0;
1432    char *str, *f, *buf0;
1433    unsigned char *p;
1434    char num[32];
1435    time_t t;
1436    static char hexchars[] = "0123456789abcdef";
1437
1438    buf0 = buf;
1439    --buflen;
1440    while (buflen > 0) {
1441	for (f = fmt; *f != '%' && *f != 0; ++f)
1442	    ;
1443	if (f > fmt) {
1444	    len = f - fmt;
1445	    if (len > buflen)
1446		len = buflen;
1447	    memcpy(buf, fmt, len);
1448	    buf += len;
1449	    buflen -= len;
1450	    fmt = f;
1451	}
1452	if (*fmt == 0)
1453	    break;
1454	c = *++fmt;
1455	width = prec = 0;
1456	fillch = ' ';
1457	if (c == '0') {
1458	    fillch = '0';
1459	    c = *++fmt;
1460	}
1461	if (c == '*') {
1462	    width = va_arg(args, int);
1463	    c = *++fmt;
1464	} else {
1465	    while (isdigit(c)) {
1466		width = width * 10 + c - '0';
1467		c = *++fmt;
1468	    }
1469	}
1470	if (c == '.') {
1471	    c = *++fmt;
1472	    if (c == '*') {
1473		prec = va_arg(args, int);
1474		c = *++fmt;
1475	    } else {
1476		while (isdigit(c)) {
1477		    prec = prec * 10 + c - '0';
1478		    c = *++fmt;
1479		}
1480	    }
1481	}
1482	str = 0;
1483	base = 0;
1484	neg = 0;
1485	++fmt;
1486	switch (c) {
1487	case 'd':
1488	    i = va_arg(args, int);
1489	    if (i < 0) {
1490		neg = 1;
1491		val = -i;
1492	    } else
1493		val = i;
1494	    base = 10;
1495	    break;
1496	case 'o':
1497	    val = va_arg(args, unsigned int);
1498	    base = 8;
1499	    break;
1500	case 'x':
1501	    val = va_arg(args, unsigned int);
1502	    base = 16;
1503	    break;
1504	case 'p':
1505	    val = (unsigned long) va_arg(args, void *);
1506	    base = 16;
1507	    neg = 2;
1508	    break;
1509	case 's':
1510	    str = va_arg(args, char *);
1511	    break;
1512	case 'c':
1513	    num[0] = va_arg(args, int);
1514	    num[1] = 0;
1515	    str = num;
1516	    break;
1517	case 'm':
1518	    str = strerror(errno);
1519	    break;
1520	case 'I':
1521	    str = ip_ntoa(va_arg(args, u_int32_t));
1522	    break;
1523	case 'r':
1524	    f = va_arg(args, char *);
1525#ifndef __powerpc__
1526	    n = vfmtmsg(buf, buflen + 1, f, va_arg(args, va_list));
1527#else
1528	    /* On the powerpc, a va_list is an array of 1 structure */
1529	    n = vfmtmsg(buf, buflen + 1, f, va_arg(args, void *));
1530#endif
1531	    buf += n;
1532	    buflen -= n;
1533	    continue;
1534	case 't':
1535	    time(&t);
1536	    str = ctime(&t);
1537	    str += 4;		/* chop off the day name */
1538	    str[15] = 0;	/* chop off year and newline */
1539	    break;
1540	case 'v':		/* "visible" string */
1541	case 'q':		/* quoted string */
1542	    quoted = c == 'q';
1543	    p = va_arg(args, unsigned char *);
1544	    if (fillch == '0' && prec > 0) {
1545		n = prec;
1546	    } else {
1547		n = strlen((char *)p);
1548		if (prec > 0 && prec < n)
1549		    n = prec;
1550	    }
1551	    while (n > 0 && buflen > 0) {
1552		c = *p++;
1553		--n;
1554		if (!quoted && c >= 0x80) {
1555		    OUTCHAR('M');
1556		    OUTCHAR('-');
1557		    c -= 0x80;
1558		}
1559		if (quoted && (c == '"' || c == '\\'))
1560		    OUTCHAR('\\');
1561		if (c < 0x20 || (0x7f <= c && c < 0xa0)) {
1562		    if (quoted) {
1563			OUTCHAR('\\');
1564			switch (c) {
1565			case '\t':	OUTCHAR('t');	break;
1566			case '\n':	OUTCHAR('n');	break;
1567			case '\b':	OUTCHAR('b');	break;
1568			case '\f':	OUTCHAR('f');	break;
1569			default:
1570			    OUTCHAR('x');
1571			    OUTCHAR(hexchars[c >> 4]);
1572			    OUTCHAR(hexchars[c & 0xf]);
1573			}
1574		    } else {
1575			if (c == '\t')
1576			    OUTCHAR(c);
1577			else {
1578			    OUTCHAR('^');
1579			    OUTCHAR(c ^ 0x40);
1580			}
1581		    }
1582		} else
1583		    OUTCHAR(c);
1584	    }
1585	    continue;
1586	default:
1587	    *buf++ = '%';
1588	    if (c != '%')
1589		--fmt;		/* so %z outputs %z etc. */
1590	    --buflen;
1591	    continue;
1592	}
1593	if (base != 0) {
1594	    str = num + sizeof(num);
1595	    *--str = 0;
1596	    while (str > num + neg) {
1597		*--str = hexchars[val % base];
1598		val = val / base;
1599		if (--prec <= 0 && val == 0)
1600		    break;
1601	    }
1602	    switch (neg) {
1603	    case 1:
1604		*--str = '-';
1605		break;
1606	    case 2:
1607		*--str = 'x';
1608		*--str = '0';
1609		break;
1610	    }
1611	    len = num + sizeof(num) - 1 - str;
1612	} else {
1613	    len = strlen(str);
1614	    if (prec > 0 && len > prec)
1615		len = prec;
1616	}
1617	if (width > 0) {
1618	    if (width > buflen)
1619		width = buflen;
1620	    if ((n = width - len) > 0) {
1621		buflen -= n;
1622		for (; n > 0; --n)
1623		    *buf++ = fillch;
1624	    }
1625	}
1626	if (len > buflen)
1627	    len = buflen;
1628	memcpy(buf, str, len);
1629	buf += len;
1630	buflen -= len;
1631    }
1632    *buf = 0;
1633    return buf - buf0;
1634}
1635
1636/*
1637 * script_setenv - set an environment variable value to be used
1638 * for scripts that we run (e.g. ip-up, auth-up, etc.)
1639 */
1640void
1641script_setenv(var, value)
1642    char *var, *value;
1643{
1644    int vl = strlen(var);
1645    int i;
1646    char *p, *newstring;
1647
1648    newstring = (char *) malloc(vl + strlen(value) + 2);
1649    if (newstring == 0)
1650	novm("script_setenv");
1651    strcpy(newstring, var);
1652    newstring[vl] = '=';
1653    strcpy(newstring+vl+1, value);
1654
1655    /* check if this variable is already set */
1656    if (script_env != 0) {
1657	for (i = 0; (p = script_env[i]) != 0; ++i) {
1658	    if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
1659		free(p);
1660		script_env[i] = newstring;
1661		return;
1662	    }
1663	}
1664    } else {
1665	i = 0;
1666	script_env = (char **) malloc(16 * sizeof(char *));
1667	if (script_env == 0)
1668	    novm("script_setenv");
1669	s_env_nalloc = 16;
1670    }
1671
1672    /* reallocate script_env with more space if needed */
1673    if (i + 1 >= s_env_nalloc) {
1674	int new_n = i + 17;
1675	char **newenv = (char **) realloc((void *)script_env,
1676					  new_n * sizeof(char *));
1677	if (newenv == 0)
1678	    novm("script_setenv");
1679	script_env = newenv;
1680	s_env_nalloc = new_n;
1681    }
1682
1683    script_env[i] = newstring;
1684    script_env[i+1] = 0;
1685}
1686
1687/*
1688 * script_unsetenv - remove a variable from the environment
1689 * for scripts.
1690 */
1691void
1692script_unsetenv(var)
1693    char *var;
1694{
1695    int vl = strlen(var);
1696    int i;
1697    char *p;
1698
1699    if (script_env == 0)
1700	return;
1701    for (i = 0; (p = script_env[i]) != 0; ++i) {
1702	if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
1703	    free(p);
1704	    while ((script_env[i] = script_env[i+1]) != 0)
1705		++i;
1706	    break;
1707	}
1708    }
1709}
1710