main.c revision 1.41 
1/*	$OpenBSD: main.c,v 1.41 2003/04/14 03:14:59 deraadt 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 1.41 2003/04/14 03:14:59 deraadt 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	strlcpy(devnam, p, MAXPATHLEN);
212    strlcpy(default_devnam, devnam, sizeof default_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    snprintf(numbuf, sizeof 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    snprintf(numbuf, sizeof 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) snprintf(ifname, sizeof 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) snprintf(ifname, sizeof 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) snprintf(pidfilename, sizeof pidfilename,
665	"%s%s.pid", _PATH_VARRUN, ifname);
666    if ((pidfile = fopen(pidfilename, "w")) != NULL) {
667	fprintf(pidfile, "%ld\n", (long)pid);
668	(void) fclose(pidfile);
669    } else {
670	syslog(LOG_ERR, "Failed to create pid file %s: %m", pidfilename);
671	pidfilename[0] = 0;
672    }
673}
674
675/*
676 * holdoff_end - called via a timeout when the holdoff period ends.
677 */
678static void
679holdoff_end(arg)
680    void *arg;
681{
682    phase = PHASE_DORMANT;
683}
684
685/*
686 * get_input - called when incoming data is available.
687 */
688static void
689get_input()
690{
691    int len, i;
692    u_char *p;
693    u_short protocol;
694    struct protent *protp;
695
696    p = inpacket_buf;	/* point to beginning of packet buffer */
697
698    len = read_packet(inpacket_buf);
699    if (len < 0)
700	return;
701
702    if (len == 0) {
703	syslog(LOG_NOTICE, "Modem hangup");
704	hungup = 1;
705	lcp_lowerdown(0);	/* serial link is no longer available */
706	link_terminated(0);
707	return;
708    }
709
710    if (debug /*&& (debugflags & DBG_INPACKET)*/)
711	log_packet(p, len, "rcvd ", LOG_DEBUG);
712
713    if (len < PPP_HDRLEN) {
714	MAINDEBUG((LOG_INFO, "io(): Received short packet."));
715	return;
716    }
717
718    p += 2;				/* Skip address and control */
719    GETSHORT(protocol, p);
720    len -= PPP_HDRLEN;
721
722    /*
723     * Toss all non-LCP packets unless LCP is OPEN.
724     */
725    if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) {
726	MAINDEBUG((LOG_INFO,
727		   "get_input: Received non-LCP packet when LCP not open."));
728	return;
729    }
730
731    /*
732     * Until we get past the authentication phase, toss all packets
733     * except LCP, LQR and authentication packets.
734     */
735    if (phase <= PHASE_AUTHENTICATE
736	&& !(protocol == PPP_LCP || protocol == PPP_LQR
737	|| protocol == PPP_PAP || protocol == PPP_CHAP)) {
738	MAINDEBUG((LOG_INFO, "get_input: discarding proto 0x%x in phase %d",
739		   protocol, phase));
740	return;
741    }
742
743    /*
744     * Upcall the proper protocol input routine.
745     */
746    for (i = 0; (protp = protocols[i]) != NULL; ++i) {
747	if (protp->protocol == protocol && protp->enabled_flag) {
748	    (*protp->input)(0, p, len);
749	    return;
750	}
751	if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
752	    && protp->datainput != NULL) {
753	    (*protp->datainput)(0, p, len);
754	    return;
755	}
756    }
757
758    if (debug)
759    	syslog(LOG_WARNING, "Unsupported protocol (0x%x) received", protocol);
760    lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
761}
762
763
764/*
765 * quit - Clean up state and exit (with an error indication).
766 */
767void
768quit()
769{
770    die(1);
771}
772
773/*
774 * die - like quit, except we can specify an exit status.
775 */
776void
777die(status)
778    int status;
779{
780    struct syslog_data sdata = SYSLOG_DATA_INIT;
781
782    cleanup();
783    syslog_r(LOG_INFO, &sdata, "Exit.");
784    _exit(status);
785}
786
787/*
788 * cleanup - restore anything which needs to be restored before we exit
789 */
790/* ARGSUSED */
791static void
792cleanup()
793{
794    sys_cleanup();
795
796    if (ttyfd >= 0)
797	close_tty();
798
799    if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT)
800	syslog(LOG_WARNING, "unable to delete pid file: %m");
801    pidfilename[0] = 0;
802
803    if (locked)
804	unlock();
805}
806
807/*
808 * close_tty - restore the terminal device and close it.
809 */
810static void
811close_tty()
812{
813    disestablish_ppp(ttyfd);
814
815    /* drop dtr to hang up */
816    if (modem) {
817	setdtr(ttyfd, FALSE);
818	/*
819	 * This sleep is in case the serial port has CLOCAL set by default,
820	 * and consequently will reassert DTR when we close the device.
821	 */
822	sleep(1);
823    }
824
825    restore_tty(ttyfd);
826
827    if (tty_mode != (mode_t) -1)
828	fchmod(ttyfd, tty_mode);
829
830    close(ttyfd);
831    ttyfd = -1;
832}
833
834
835struct	callout {
836    struct timeval	c_time;		/* time at which to call routine */
837    void		*c_arg;		/* argument to routine */
838    void		(*c_func)(void *); /* routine */
839    struct		callout *c_next;
840};
841
842static struct callout *callout = NULL;	/* Callout list */
843static struct timeval timenow;		/* Current time */
844
845/*
846 * timeout - Schedule a timeout.
847 *
848 * Note that this timeout takes the number of seconds, NOT hz (as in
849 * the kernel).
850 */
851void
852timeout(func, arg, time)
853    void (*func)(void *);
854    void *arg;
855    int time;
856{
857    struct callout *newp, *p, **pp;
858
859    MAINDEBUG((LOG_DEBUG, "Timeout %lx:%lx in %d seconds.",
860	       (long) func, (long) arg, time));
861
862    /*
863     * Allocate timeout.
864     */
865    if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL) {
866	syslog(LOG_ERR, "Out of memory in timeout()!");
867	die(1);
868    }
869    newp->c_arg = arg;
870    newp->c_func = func;
871    gettimeofday(&timenow, NULL);
872    newp->c_time.tv_sec = timenow.tv_sec + time;
873    newp->c_time.tv_usec = timenow.tv_usec;
874
875    /*
876     * Find correct place and link it in.
877     */
878    for (pp = &callout; (p = *pp); pp = &p->c_next)
879	if (newp->c_time.tv_sec < p->c_time.tv_sec
880	    || (newp->c_time.tv_sec == p->c_time.tv_sec
881		&& newp->c_time.tv_usec < p->c_time.tv_sec))
882	    break;
883    newp->c_next = p;
884    *pp = newp;
885}
886
887
888/*
889 * untimeout - Unschedule a timeout.
890 */
891void
892untimeout(func, arg)
893    void (*func)(void *);
894    void *arg;
895{
896    struct callout **copp, *freep;
897
898    MAINDEBUG((LOG_DEBUG, "Untimeout %lx:%lx.", (long) func, (long) arg));
899
900    /*
901     * Find first matching timeout and remove it from the list.
902     */
903    for (copp = &callout; (freep = *copp); copp = &freep->c_next)
904	if (freep->c_func == func && freep->c_arg == arg) {
905	    *copp = freep->c_next;
906	    (void) free((char *) freep);
907	    break;
908	}
909}
910
911
912/*
913 * calltimeout - Call any timeout routines which are now due.
914 */
915static void
916calltimeout()
917{
918    struct callout *p;
919
920    while (callout != NULL) {
921	p = callout;
922
923	if (gettimeofday(&timenow, NULL) < 0) {
924	    syslog(LOG_ERR, "Failed to get time of day: %m");
925	    die(1);
926	}
927	if (!(p->c_time.tv_sec < timenow.tv_sec
928	      || (p->c_time.tv_sec == timenow.tv_sec
929		  && p->c_time.tv_usec <= timenow.tv_usec)))
930	    break;		/* no, it's not time yet */
931
932	callout = p->c_next;
933	(*p->c_func)(p->c_arg);
934
935	free((char *) p);
936    }
937}
938
939
940/*
941 * timeleft - return the length of time until the next timeout is due.
942 */
943static struct timeval *
944timeleft(tvp)
945    struct timeval *tvp;
946{
947    if (callout == NULL)
948	return NULL;
949
950    gettimeofday(&timenow, NULL);
951    tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
952    tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
953    if (tvp->tv_usec < 0) {
954	tvp->tv_usec += 1000000;
955	tvp->tv_sec -= 1;
956    }
957    if (tvp->tv_sec < 0)
958	tvp->tv_sec = tvp->tv_usec = 0;
959
960    return tvp;
961}
962
963
964/*
965 * kill_my_pg - send a signal to our process group, and ignore it ourselves.
966 */
967static void
968kill_my_pg(sig)
969    int sig;
970{
971    struct sigaction act, oldact;
972
973    act.sa_handler = SIG_IGN;
974    act.sa_flags = 0;
975    kill(0, sig);
976    sigaction(sig, &act, &oldact);
977    sigaction(sig, &oldact, NULL);
978}
979
980
981/*
982 * hup - Catch SIGHUP signal.
983 *
984 * Indicates that the physical layer has been disconnected.
985 * We don't rely on this indication; if the user has sent this
986 * signal, we just take the link down.
987 */
988static void
989hup(sig)
990    int sig;
991{
992    int save_errno = errno;
993    struct syslog_data sdata = SYSLOG_DATA_INIT;
994
995    if (crashed)
996	_exit(127);
997    syslog_r(LOG_INFO, &sdata, "Hangup (SIGHUP)");
998    kill_link = 1;
999    if (conn_running)
1000	/* Send the signal to the [dis]connector process(es) also */
1001	kill_my_pg(sig);
1002    errno = save_errno;
1003}
1004
1005
1006/*
1007 * term - Catch SIGTERM signal and SIGINT signal (^C/del).
1008 *
1009 * Indicates that we should initiate a graceful disconnect and exit.
1010 */
1011/*ARGSUSED*/
1012static void
1013term(sig)
1014    int sig;
1015{
1016    int save_errno = errno;
1017    struct syslog_data sdata = SYSLOG_DATA_INIT;
1018
1019    if (crashed)
1020	_exit(127);
1021    syslog_r(LOG_INFO, &sdata, "Terminating on signal %d.", sig);
1022    persist = 0;		/* don't try to restart */
1023    kill_link = 1;
1024    if (conn_running)
1025	/* Send the signal to the [dis]connector process(es) also */
1026	kill_my_pg(sig);
1027    errno = save_errno;
1028}
1029
1030
1031/*
1032 * chld - Catch SIGCHLD signal.
1033 * Calls reap_kids to get status for any dead kids.
1034 */
1035static void
1036chld(sig)
1037    int sig;
1038{
1039    int save_errno = errno;
1040
1041    reap_kids();		/* XXX somewhat unsafe */
1042    errno = save_errno;
1043}
1044
1045
1046/*
1047 * toggle_debug - Catch SIGUSR1 signal.
1048 *
1049 * Toggle debug flag.
1050 */
1051/*ARGSUSED*/
1052static void
1053toggle_debug(sig)
1054    int sig;
1055{
1056    debug = !debug;
1057    if (debug) {
1058	setlogmask(LOG_UPTO(LOG_DEBUG));	/* XXX safe, but wrong */
1059    } else {
1060	setlogmask(LOG_UPTO(LOG_WARNING));	/* XXX safe, but wrong */
1061    }
1062}
1063
1064
1065/*
1066 * open_ccp - Catch SIGUSR2 signal.
1067 *
1068 * Try to (re)negotiate compression.
1069 */
1070/*ARGSUSED*/
1071static void
1072open_ccp(sig)
1073    int sig;
1074{
1075    open_ccp_flag = 1;
1076}
1077
1078
1079/*
1080 * bad_signal - We've caught a fatal signal.  Clean up state and exit.
1081 */
1082static void
1083bad_signal(sig)
1084    int sig;
1085{
1086    struct syslog_data sdata = SYSLOG_DATA_INIT;
1087
1088    if (crashed)
1089	_exit(127);
1090    crashed = 1;
1091    syslog_r(LOG_ERR, &sdata, "Fatal signal %d", sig);
1092    if (conn_running)
1093	kill_my_pg(SIGTERM);
1094    die(1);					/* XXX unsafe! */
1095}
1096
1097
1098/*
1099 * device_script - run a program to connect or disconnect the
1100 * serial device.
1101 */
1102static int
1103device_script(program, in, out)
1104    char *program;
1105    int in, out;
1106{
1107    pid_t pid;
1108    int status;
1109    int errfd;
1110
1111    conn_running = 1;
1112    pid = fork();
1113
1114    if (pid < 0) {
1115	conn_running = 0;
1116	syslog(LOG_ERR, "Failed to create child process: %m");
1117	die(1);
1118    }
1119
1120    if (pid == 0) {
1121	sys_close();
1122	closelog();
1123	if (in == out) {
1124	    if (in != 0) {
1125		dup2(in, 0);
1126		close(in);
1127	    }
1128	    dup2(0, 1);
1129	} else {
1130	    if (out == 0)
1131		out = dup(out);
1132	    if (in != 0) {
1133		dup2(in, 0);
1134		close(in);
1135	    }
1136	    if (out != 1) {
1137		dup2(out, 1);
1138		close(out);
1139	    }
1140	}
1141	if (nodetach == 0) {
1142	    close(2);
1143	    errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0600);
1144	    if (errfd >= 0 && errfd != 2) {
1145		dup2(errfd, 2);
1146		close(errfd);
1147	    }
1148	}
1149	/* revoke privs */
1150	seteuid(getuid());
1151	setuid(getuid());
1152	setegid(getgid());
1153	setgid(getgid());
1154	execl("/bin/sh", "sh", "-c", program, (char *)0);
1155	syslog(LOG_ERR, "could not exec /bin/sh: %m");
1156	_exit(99);
1157	/* NOTREACHED */
1158    }
1159
1160    while (waitpid(pid, &status, 0) < 0) {
1161	if (errno == EINTR)
1162	    continue;
1163	syslog(LOG_ERR, "error waiting for (dis)connection process: %m");
1164	die(1);
1165    }
1166    conn_running = 0;
1167
1168    return (status == 0 ? 0 : -1);
1169}
1170
1171
1172/*
1173 * run-program - execute a program with given arguments,
1174 * but don't wait for it.
1175 * If the program can't be executed, logs an error unless
1176 * must_exist is 0 and the program file doesn't exist.
1177 */
1178int
1179run_program(prog, args, must_exist)
1180    char *prog;
1181    char **args;
1182    int must_exist;
1183{
1184    pid_t pid;
1185
1186    pid = fork();
1187    if (pid == -1) {
1188	syslog(LOG_ERR, "Failed to create child process for %s: %m", prog);
1189	return -1;
1190    }
1191    if (pid == 0) {
1192	int new_fd;
1193
1194	/* Leave the current location */
1195	(void) setsid();    /* No controlling tty. */
1196	(void) umask (S_IRWXG|S_IRWXO);
1197	(void) chdir ("/"); /* no current directory. */
1198	setuid(geteuid());
1199	setgid(getegid());
1200
1201	/* Ensure that nothing of our device environment is inherited. */
1202	sys_close();
1203	closelog();
1204	close (0);
1205	close (1);
1206	close (2);
1207	close (ttyfd);  /* tty interface to the ppp device */
1208
1209	/* Don't pass handles to the PPP device, even by accident. */
1210	new_fd = open (_PATH_DEVNULL, O_RDWR);
1211	if (new_fd >= 0) {
1212	    if (new_fd != 0) {
1213		dup2  (new_fd, 0); /* stdin <- /dev/null */
1214		close (new_fd);
1215	    }
1216	    dup2 (0, 1); /* stdout -> /dev/null */
1217	    dup2 (0, 2); /* stderr -> /dev/null */
1218	}
1219
1220#ifdef BSD
1221	/* Force the priority back to zero if pppd is running higher. */
1222	if (setpriority (PRIO_PROCESS, 0, 0) < 0)
1223	    syslog (LOG_WARNING, "can't reset priority to 0: %m");
1224#endif
1225
1226	/* SysV recommends a second fork at this point. */
1227
1228	/* run the program; give it a null environment */
1229	execve(prog, args, script_env);
1230	if (must_exist || errno != ENOENT)
1231	    syslog(LOG_WARNING, "Can't execute %s: %m", prog);
1232	_exit(1);
1233    }
1234    MAINDEBUG((LOG_DEBUG, "Script %s started; pid = %ld", prog, (long)pid));
1235    ++n_children;
1236    return 0;
1237}
1238
1239
1240/*
1241 * reap_kids - get status from any dead child processes,
1242 * and log a message for abnormal terminations.
1243 */
1244static void
1245reap_kids()
1246{
1247    int status;
1248    pid_t pid;
1249
1250    if (n_children == 0)
1251	return;
1252    if ((pid = waitpid(-1, &status, WNOHANG)) == -1) {
1253	if (errno != ECHILD)
1254	    syslog(LOG_ERR, "Error waiting for child process: %m");
1255	return;
1256    }
1257    if (pid > 0) {
1258	--n_children;
1259	if (WIFSIGNALED(status)) {
1260	    syslog(LOG_WARNING, "Child process %ld terminated with signal %d",
1261		   (long)pid, WTERMSIG(status));
1262	}
1263    }
1264}
1265
1266
1267/*
1268 * log_packet - format a packet and log it.
1269 */
1270
1271char line[256];			/* line to be logged accumulated here */
1272char *linep;
1273
1274void
1275log_packet(p, len, prefix, level)
1276    u_char *p;
1277    int len;
1278    char *prefix;
1279    int level;
1280{
1281    strlcpy(line, prefix, sizeof line);
1282    linep = line + strlen(line);
1283    format_packet(p, len, pr_log, NULL);
1284    if (linep != line)
1285	syslog(level, "%s", line);
1286}
1287
1288/*
1289 * format_packet - make a readable representation of a packet,
1290 * calling `printer(arg, format, ...)' to output it.
1291 */
1292void
1293format_packet(p, len, printer, arg)
1294    u_char *p;
1295    int len;
1296    void (*printer)(void *, char *, ...);
1297    void *arg;
1298{
1299    int i, n;
1300    u_short proto;
1301    u_char x;
1302    struct protent *protp;
1303
1304    if (len >= PPP_HDRLEN && p[0] == PPP_ALLSTATIONS && p[1] == PPP_UI) {
1305	p += 2;
1306	GETSHORT(proto, p);
1307	len -= PPP_HDRLEN;
1308	for (i = 0; (protp = protocols[i]) != NULL; ++i)
1309	    if (proto == protp->protocol)
1310		break;
1311	if (protp != NULL) {
1312	    printer(arg, "[%s", protp->name);
1313	    n = (*protp->printpkt)(p, len, printer, arg);
1314	    printer(arg, "]");
1315	    p += n;
1316	    len -= n;
1317	} else {
1318	    printer(arg, "[proto=0x%x]", proto);
1319	}
1320    }
1321
1322    for (; len > 0; --len) {
1323	GETCHAR(x, p);
1324	printer(arg, " %.2x", x);
1325    }
1326}
1327
1328static void
1329pr_log(void *arg, char *fmt, ...)
1330{
1331    int n;
1332    va_list pvar;
1333    char buf[256];
1334
1335    va_start(pvar, fmt);
1336
1337    n = vfmtmsg(buf, sizeof(buf), fmt, pvar);
1338    va_end(pvar);
1339
1340    if (linep + n + 1 > line + sizeof(line)) {
1341	syslog(LOG_DEBUG, "%s", line);
1342	linep = line;
1343    }
1344    strlcpy(linep, buf, line + sizeof line - linep);
1345    linep += n;
1346}
1347
1348/*
1349 * print_string - print a readable representation of a string using
1350 * printer.
1351 */
1352void
1353print_string(p, len, printer, arg)
1354    char *p;
1355    int len;
1356    void (*printer)(void *, char *, ...);
1357    void *arg;
1358{
1359    int c;
1360
1361    printer(arg, "\"");
1362    for (; len > 0; --len) {
1363	c = *p++;
1364	if (' ' <= c && c <= '~') {
1365	    if (c == '\\' || c == '"')
1366		printer(arg, "\\");
1367	    printer(arg, "%c", c);
1368	} else {
1369	    switch (c) {
1370	    case '\n':
1371		printer(arg, "\\n");
1372		break;
1373	    case '\r':
1374		printer(arg, "\\r");
1375		break;
1376	    case '\t':
1377		printer(arg, "\\t");
1378		break;
1379	    default:
1380		printer(arg, "\\%.3o", c);
1381	    }
1382	}
1383    }
1384    printer(arg, "\"");
1385}
1386
1387/*
1388 * novm - log an error message saying we ran out of memory, and die.
1389 */
1390void
1391novm(msg)
1392    char *msg;
1393{
1394    syslog(LOG_ERR, "Virtual memory exhausted allocating %s", msg);
1395    die(1);
1396}
1397
1398/*
1399 * fmtmsg - format a message into a buffer.  Like sprintf except we
1400 * also specify the length of the output buffer, and we handle
1401 * %r (recursive format), %m (error message) and %I (IP address) formats.
1402 * Doesn't do floating-point formats.
1403 * Returns the number of chars put into buf.
1404 */
1405int
1406fmtmsg(char *buf, int buflen, char *fmt, ...)
1407{
1408    va_list args;
1409    int n;
1410
1411    va_start(args, fmt);
1412    n = vfmtmsg(buf, buflen, fmt, args);
1413    va_end(args);
1414    return n;
1415}
1416
1417/*
1418 * vfmtmsg - like fmtmsg, takes a va_list instead of a list of args.
1419 */
1420#define OUTCHAR(c)	(buflen > 0? (--buflen, *buf++ = (c)): 0)
1421
1422int
1423vfmtmsg(buf, buflen, fmt, args)
1424    char *buf;
1425    int buflen;
1426    char *fmt;
1427    va_list args;
1428{
1429    int c, i, n;
1430    int width, prec, fillch;
1431    int base, len, neg, quoted;
1432    unsigned long val = 0;
1433    char *str, *f, *buf0;
1434    unsigned char *p;
1435    char num[32];
1436    time_t t;
1437    static char hexchars[] = "0123456789abcdef";
1438
1439    buf0 = buf;
1440    --buflen;
1441    while (buflen > 0) {
1442	for (f = fmt; *f != '%' && *f != 0; ++f)
1443	    ;
1444	if (f > fmt) {
1445	    len = f - fmt;
1446	    if (len > buflen)
1447		len = buflen;
1448	    memcpy(buf, fmt, len);
1449	    buf += len;
1450	    buflen -= len;
1451	    fmt = f;
1452	}
1453	if (*fmt == 0)
1454	    break;
1455	c = *++fmt;
1456	width = prec = 0;
1457	fillch = ' ';
1458	if (c == '0') {
1459	    fillch = '0';
1460	    c = *++fmt;
1461	}
1462	if (c == '*') {
1463	    width = va_arg(args, int);
1464	    c = *++fmt;
1465	} else {
1466	    while (isdigit(c)) {
1467		width = width * 10 + c - '0';
1468		c = *++fmt;
1469	    }
1470	}
1471	if (c == '.') {
1472	    c = *++fmt;
1473	    if (c == '*') {
1474		prec = va_arg(args, int);
1475		c = *++fmt;
1476	    } else {
1477		while (isdigit(c)) {
1478		    prec = prec * 10 + c - '0';
1479		    c = *++fmt;
1480		}
1481	    }
1482	}
1483	str = 0;
1484	base = 0;
1485	neg = 0;
1486	++fmt;
1487	switch (c) {
1488	case 'd':
1489	    i = va_arg(args, int);
1490	    if (i < 0) {
1491		neg = 1;
1492		val = -i;
1493	    } else
1494		val = i;
1495	    base = 10;
1496	    break;
1497	case 'o':
1498	    val = va_arg(args, unsigned int);
1499	    base = 8;
1500	    break;
1501	case 'x':
1502	    val = va_arg(args, unsigned int);
1503	    base = 16;
1504	    break;
1505	case 'p':
1506	    val = (unsigned long) va_arg(args, void *);
1507	    base = 16;
1508	    neg = 2;
1509	    break;
1510	case 's':
1511	    str = va_arg(args, char *);
1512	    break;
1513	case 'c':
1514	    num[0] = va_arg(args, int);
1515	    num[1] = 0;
1516	    str = num;
1517	    break;
1518	case 'm':
1519	    str = strerror(errno);
1520	    break;
1521	case 'I':
1522	    str = ip_ntoa(va_arg(args, u_int32_t));
1523	    break;
1524	case 'r':
1525	    f = va_arg(args, char *);
1526#ifndef __powerpc__
1527	    n = vfmtmsg(buf, buflen + 1, f, va_arg(args, va_list));
1528#else
1529	    /* On the powerpc, a va_list is an array of 1 structure */
1530	    n = vfmtmsg(buf, buflen + 1, f, va_arg(args, void *));
1531#endif
1532	    buf += n;
1533	    buflen -= n;
1534	    continue;
1535	case 't':
1536	    time(&t);
1537	    str = ctime(&t);
1538	    str += 4;		/* chop off the day name */
1539	    str[15] = 0;	/* chop off year and newline */
1540	    break;
1541	case 'v':		/* "visible" string */
1542	case 'q':		/* quoted string */
1543	    quoted = c == 'q';
1544	    p = va_arg(args, unsigned char *);
1545	    if (fillch == '0' && prec > 0) {
1546		n = prec;
1547	    } else {
1548		n = strlen((char *)p);
1549		if (prec > 0 && prec < n)
1550		    n = prec;
1551	    }
1552	    while (n > 0 && buflen > 0) {
1553		c = *p++;
1554		--n;
1555		if (!quoted && c >= 0x80) {
1556		    OUTCHAR('M');
1557		    OUTCHAR('-');
1558		    c -= 0x80;
1559		}
1560		if (quoted && (c == '"' || c == '\\'))
1561		    OUTCHAR('\\');
1562		if (c < 0x20 || (0x7f <= c && c < 0xa0)) {
1563		    if (quoted) {
1564			OUTCHAR('\\');
1565			switch (c) {
1566			case '\t':	OUTCHAR('t');	break;
1567			case '\n':	OUTCHAR('n');	break;
1568			case '\b':	OUTCHAR('b');	break;
1569			case '\f':	OUTCHAR('f');	break;
1570			default:
1571			    OUTCHAR('x');
1572			    OUTCHAR(hexchars[c >> 4]);
1573			    OUTCHAR(hexchars[c & 0xf]);
1574			}
1575		    } else {
1576			if (c == '\t')
1577			    OUTCHAR(c);
1578			else {
1579			    OUTCHAR('^');
1580			    OUTCHAR(c ^ 0x40);
1581			}
1582		    }
1583		} else
1584		    OUTCHAR(c);
1585	    }
1586	    continue;
1587	default:
1588	    *buf++ = '%';
1589	    if (c != '%')
1590		--fmt;		/* so %z outputs %z etc. */
1591	    --buflen;
1592	    continue;
1593	}
1594	if (base != 0) {
1595	    str = num + sizeof(num);
1596	    *--str = 0;
1597	    while (str > num + neg) {
1598		*--str = hexchars[val % base];
1599		val = val / base;
1600		if (--prec <= 0 && val == 0)
1601		    break;
1602	    }
1603	    switch (neg) {
1604	    case 1:
1605		*--str = '-';
1606		break;
1607	    case 2:
1608		*--str = 'x';
1609		*--str = '0';
1610		break;
1611	    }
1612	    len = num + sizeof(num) - 1 - str;
1613	} else {
1614	    len = strlen(str);
1615	    if (prec > 0 && len > prec)
1616		len = prec;
1617	}
1618	if (width > 0) {
1619	    if (width > buflen)
1620		width = buflen;
1621	    if ((n = width - len) > 0) {
1622		buflen -= n;
1623		for (; n > 0; --n)
1624		    *buf++ = fillch;
1625	    }
1626	}
1627	if (len > buflen)
1628	    len = buflen;
1629	memcpy(buf, str, len);
1630	buf += len;
1631	buflen -= len;
1632    }
1633    *buf = 0;
1634    return buf - buf0;
1635}
1636
1637/*
1638 * script_setenv - set an environment variable value to be used
1639 * for scripts that we run (e.g. ip-up, auth-up, etc.)
1640 */
1641void
1642script_setenv(var, value)
1643    char *var, *value;
1644{
1645    int vl = strlen(var);
1646    int i;
1647    char *p, *newstring;
1648
1649    if (asprintf(&newstring, "%s=%s", var, value) == -1)
1650	novm("script_setenv");
1651
1652    /* check if this variable is already set */
1653    if (script_env != 0) {
1654	for (i = 0; (p = script_env[i]) != 0; ++i) {
1655	    if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
1656		free(p);
1657		script_env[i] = newstring;
1658		return;
1659	    }
1660	}
1661    } else {
1662	i = 0;
1663	script_env = (char **) malloc(16 * sizeof(char *));
1664	if (script_env == 0)
1665	    novm("script_setenv");
1666	s_env_nalloc = 16;
1667    }
1668
1669    /* reallocate script_env with more space if needed */
1670    if (i + 1 >= s_env_nalloc) {
1671	int new_n = i + 17;
1672	char **newenv = (char **) realloc((void *)script_env,
1673					  new_n * sizeof(char *));
1674	if (newenv == 0)
1675	    novm("script_setenv");
1676	script_env = newenv;
1677	s_env_nalloc = new_n;
1678    }
1679
1680    script_env[i] = newstring;
1681    script_env[i+1] = 0;
1682}
1683
1684/*
1685 * script_unsetenv - remove a variable from the environment
1686 * for scripts.
1687 */
1688void
1689script_unsetenv(var)
1690    char *var;
1691{
1692    int vl = strlen(var);
1693    int i;
1694    char *p;
1695
1696    if (script_env == 0)
1697	return;
1698    for (i = 0; (p = script_env[i]) != 0; ++i) {
1699	if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
1700	    free(p);
1701	    while ((script_env[i] = script_env[i+1]) != 0)
1702		++i;
1703	    break;
1704	}
1705    }
1706}
1707