main.c revision 1.2
1/* 2 * main.c - Point-to-Point Protocol main module 3 * 4 * Copyright (c) 1989 Carnegie Mellon University. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms are permitted 8 * provided that the above copyright notice and this paragraph are 9 * duplicated in all such forms and that any documentation, 10 * advertising materials, and other materials related to such 11 * distribution and use acknowledge that the software was developed 12 * by Carnegie Mellon University. The name of the 13 * University may not be used to endorse or promote products derived 14 * from this software without specific prior written permission. 15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 17 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 18 */ 19 20#ifndef lint 21static char rcsid[] = "$Id: main.c,v 1.2 1995/12/28 14:05:06 hannken Exp $"; 22#endif 23 24#include <stdio.h> 25#include <stdlib.h> 26#include <string.h> 27#include <signal.h> 28#include <errno.h> 29#include <fcntl.h> 30#include <syslog.h> 31#include <netdb.h> 32#include <utmp.h> 33#include <pwd.h> 34#include <sys/param.h> 35#include <sys/types.h> 36#include <sys/wait.h> 37#include <sys/time.h> 38#include <sys/resource.h> 39#include <sys/stat.h> 40#include <sys/socket.h> 41#include <net/if.h> 42 43#include "pppd.h" 44#include "magic.h" 45#include "fsm.h" 46#include "lcp.h" 47#include "ipcp.h" 48#include "upap.h" 49#include "chap.h" 50#include "ccp.h" 51#include "pathnames.h" 52#include "patchlevel.h" 53 54/* 55 * If REQ_SYSOPTIONS is defined to 1, pppd will not run unless 56 * /etc/ppp/options exists. 57 */ 58#ifndef REQ_SYSOPTIONS 59#define REQ_SYSOPTIONS 1 60#endif 61 62/* interface vars */ 63char ifname[IFNAMSIZ]; /* Interface name */ 64int ifunit; /* Interface unit number */ 65 66char *progname; /* Name of this program */ 67char hostname[MAXNAMELEN]; /* Our hostname */ 68static char pidfilename[MAXPATHLEN]; /* name of pid file */ 69static char default_devnam[MAXPATHLEN]; /* name of default device */ 70static pid_t pid; /* Our pid */ 71static pid_t pgrpid; /* Process Group ID */ 72static uid_t uid; /* Our real user-id */ 73 74int fd = -1; /* Device file descriptor */ 75 76int phase; /* where the link is at */ 77int kill_link; 78int open_ccp_flag; 79 80static int initfdflags = -1; /* Initial file descriptor flags */ 81 82u_char outpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for outgoing packet */ 83static u_char inpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for incoming packet */ 84 85int hungup; /* terminal has been hung up */ 86static int n_children; /* # child processes still running */ 87 88int baud_rate; 89 90char *no_ppp_msg = "Sorry - this system lacks PPP kernel support\n"; 91 92/* prototypes */ 93static void hup __P((int)); 94static void term __P((int)); 95static void chld __P((int)); 96static void toggle_debug __P((int)); 97static void open_ccp __P((int)); 98static void bad_signal __P((int)); 99 100static void get_input __P((void)); 101void establish_ppp __P((void)); 102void calltimeout __P((void)); 103struct timeval *timeleft __P((struct timeval *)); 104void reap_kids __P((void)); 105void cleanup __P((int, caddr_t)); 106void close_fd __P((void)); 107void die __P((int)); 108void novm __P((char *)); 109 110void log_packet __P((u_char *, int, char *)); 111void format_packet __P((u_char *, int, 112 void (*) (void *, char *, ...), void *)); 113void pr_log __P((void *, char *, ...)); 114 115extern char *ttyname __P((int)); 116extern char *getlogin __P((void)); 117 118#ifdef ultrix 119#undef O_NONBLOCK 120#define O_NONBLOCK O_NDELAY 121#endif 122 123/* 124 * PPP Data Link Layer "protocol" table. 125 * One entry per supported protocol. 126 */ 127static struct protent { 128 u_short protocol; 129 void (*init)(); 130 void (*input)(); 131 void (*protrej)(); 132 int (*printpkt)(); 133 void (*datainput)(); 134 char *name; 135} prottbl[] = { 136 { PPP_LCP, lcp_init, lcp_input, lcp_protrej, 137 lcp_printpkt, NULL, "LCP" }, 138 { PPP_IPCP, ipcp_init, ipcp_input, ipcp_protrej, 139 ipcp_printpkt, NULL, "IPCP" }, 140 { PPP_PAP, upap_init, upap_input, upap_protrej, 141 upap_printpkt, NULL, "PAP" }, 142 { PPP_CHAP, ChapInit, ChapInput, ChapProtocolReject, 143 ChapPrintPkt, NULL, "CHAP" }, 144 { PPP_CCP, ccp_init, ccp_input, ccp_protrej, 145 ccp_printpkt, ccp_datainput, "CCP" }, 146}; 147 148#define N_PROTO (sizeof(prottbl) / sizeof(prottbl[0])) 149 150main(argc, argv) 151 int argc; 152 char *argv[]; 153{ 154 int i, nonblock; 155 struct sigaction sa; 156 struct cmd *cmdp; 157 FILE *pidfile; 158 char *p; 159 struct passwd *pw; 160 struct timeval timo; 161 sigset_t mask; 162 163 p = ttyname(0); 164 if (p) 165 strcpy(devnam, p); 166 strcpy(default_devnam, devnam); 167 168 if (gethostname(hostname, MAXNAMELEN) < 0 ) { 169 perror("couldn't get hostname"); 170 die(1); 171 } 172 hostname[MAXNAMELEN-1] = 0; 173 174 uid = getuid(); 175 176 if (!ppp_available()) { 177 fprintf(stderr, no_ppp_msg); 178 exit(1); 179 } 180 181 /* 182 * Initialize to the standard option set, then parse, in order, 183 * the system options file, the user's options file, and the command 184 * line arguments. 185 */ 186 for (i = 0; i < N_PROTO; i++) 187 (*prottbl[i].init)(0); 188 189 progname = *argv; 190 191 if (!options_from_file(_PATH_SYSOPTIONS, REQ_SYSOPTIONS, 0) || 192 !options_from_user() || 193 !parse_args(argc-1, argv+1) || 194 !options_for_tty()) 195 die(1); 196 check_auth_options(); 197 setipdefault(); 198 199 /* 200 * If the user has specified the default device name explicitly, 201 * pretend they hadn't. 202 */ 203 if (!default_device && strcmp(devnam, default_devnam) == 0) 204 default_device = 1; 205 206 /* 207 * Initialize system-dependent stuff and magic number package. 208 */ 209 sys_init(); 210 magic_init(); 211 212 /* 213 * Detach ourselves from the terminal, if required, 214 * and identify who is running us. 215 */ 216 if (!default_device && !nodetach && daemon(0, 0) < 0) { 217 perror("Couldn't detach from controlling terminal"); 218 exit(1); 219 } 220 pid = getpid(); 221 p = getlogin(); 222 if (p == NULL) { 223 pw = getpwuid(uid); 224 if (pw != NULL && pw->pw_name != NULL) 225 p = pw->pw_name; 226 else 227 p = "(unknown)"; 228 } 229 syslog(LOG_NOTICE, "pppd %s.%d started by %s, uid %d", 230 VERSION, PATCHLEVEL, p, uid); 231 232 /* 233 * Compute mask of all interesting signals and install signal handlers 234 * for each. Only one signal handler may be active at a time. Therefore, 235 * all other signals should be masked when any handler is executing. 236 */ 237 sigemptyset(&mask); 238 sigaddset(&mask, SIGHUP); 239 sigaddset(&mask, SIGINT); 240 sigaddset(&mask, SIGTERM); 241 sigaddset(&mask, SIGCHLD); 242 243#define SIGNAL(s, handler) { \ 244 sa.sa_handler = handler; \ 245 if (sigaction(s, &sa, NULL) < 0) { \ 246 syslog(LOG_ERR, "Couldn't establish signal handler (%d): %m", s); \ 247 die(1); \ 248 } \ 249 } 250 251 sa.sa_mask = mask; 252 sa.sa_flags = 0; 253 SIGNAL(SIGHUP, hup); /* Hangup */ 254 SIGNAL(SIGINT, term); /* Interrupt */ 255 SIGNAL(SIGTERM, term); /* Terminate */ 256 SIGNAL(SIGCHLD, chld); 257 258 SIGNAL(SIGUSR1, toggle_debug); /* Toggle debug flag */ 259 SIGNAL(SIGUSR2, open_ccp); /* Reopen CCP */ 260 261 /* 262 * Install a handler for other signals which would otherwise 263 * cause pppd to exit without cleaning up. 264 */ 265 SIGNAL(SIGABRT, bad_signal); 266 SIGNAL(SIGALRM, bad_signal); 267 SIGNAL(SIGFPE, bad_signal); 268 SIGNAL(SIGILL, bad_signal); 269 SIGNAL(SIGPIPE, bad_signal); 270 SIGNAL(SIGQUIT, bad_signal); 271 SIGNAL(SIGSEGV, bad_signal); 272#ifdef SIGBUS 273 SIGNAL(SIGBUS, bad_signal); 274#endif 275#ifdef SIGEMT 276 SIGNAL(SIGEMT, bad_signal); 277#endif 278#ifdef SIGPOLL 279 SIGNAL(SIGPOLL, bad_signal); 280#endif 281#ifdef SIGPROF 282 SIGNAL(SIGPROF, bad_signal); 283#endif 284#ifdef SIGSYS 285 SIGNAL(SIGSYS, bad_signal); 286#endif 287#ifdef SIGTRAP 288 SIGNAL(SIGTRAP, bad_signal); 289#endif 290#ifdef SIGVTALRM 291 SIGNAL(SIGVTALRM, bad_signal); 292#endif 293#ifdef SIGXCPU 294 SIGNAL(SIGXCPU, bad_signal); 295#endif 296#ifdef SIGXFSZ 297 SIGNAL(SIGXFSZ, bad_signal); 298#endif 299 300 /* 301 * Lock the device if we've been asked to. 302 */ 303 if (lockflag && !default_device) 304 if (lock(devnam) < 0) 305 die(1); 306 307 do { 308 309 /* 310 * Open the serial device and set it up to be the ppp interface. 311 * If we're dialling out, or we don't want to use the modem lines, 312 * we open it in non-blocking mode, but then we need to clear 313 * the non-blocking I/O bit. 314 */ 315 nonblock = (connector || !modem)? O_NONBLOCK: 0; 316 if ((fd = open(devnam, nonblock | O_RDWR, 0)) < 0) { 317 syslog(LOG_ERR, "Failed to open %s: %m", devnam); 318 die(1); 319 } 320 if ((initfdflags = fcntl(fd, F_GETFL)) == -1) { 321 syslog(LOG_ERR, "Couldn't get device fd flags: %m"); 322 die(1); 323 } 324 if (nonblock) { 325 initfdflags &= ~O_NONBLOCK; 326 fcntl(fd, F_SETFL, initfdflags); 327 } 328 hungup = 0; 329 kill_link = 0; 330 331 /* run connection script */ 332 if (connector && connector[0]) { 333 MAINDEBUG((LOG_INFO, "Connecting with <%s>", connector)); 334 335 /* set line speed, flow control, etc.; set CLOCAL for now */ 336 set_up_tty(fd, 1); 337 338 /* drop dtr to hang up in case modem is off hook */ 339 if (!default_device && modem) { 340 setdtr(fd, FALSE); 341 sleep(1); 342 setdtr(fd, TRUE); 343 } 344 345 if (device_script(connector, fd, fd) < 0) { 346 syslog(LOG_ERR, "Connect script failed"); 347 setdtr(fd, FALSE); 348 die(1); 349 } 350 351 syslog(LOG_INFO, "Serial connection established."); 352 sleep(1); /* give it time to set up its terminal */ 353 } 354 355 /* set line speed, flow control, etc.; clear CLOCAL if modem option */ 356 set_up_tty(fd, 0); 357 358 /* set up the serial device as a ppp interface */ 359 establish_ppp(); 360 361 syslog(LOG_INFO, "Using interface ppp%d", ifunit); 362 (void) sprintf(ifname, "ppp%d", ifunit); 363 364 /* write pid to file */ 365 (void) sprintf(pidfilename, "%s%s.pid", _PATH_VARRUN, ifname); 366 if ((pidfile = fopen(pidfilename, "w")) != NULL) { 367 fprintf(pidfile, "%d\n", pid); 368 (void) fclose(pidfile); 369 } else { 370 syslog(LOG_ERR, "Failed to create pid file %s: %m", pidfilename); 371 pidfilename[0] = 0; 372 } 373 374 /* 375 * Set device for non-blocking reads. 376 */ 377 if (fcntl(fd, F_SETFL, initfdflags | O_NONBLOCK) == -1) { 378 syslog(LOG_ERR, "Couldn't set device to non-blocking mode: %m"); 379 die(1); 380 } 381 382 /* 383 * Block all signals, start opening the connection, and wait for 384 * incoming events (reply, timeout, etc.). 385 */ 386 syslog(LOG_NOTICE, "Connect: %s <--> %s", ifname, devnam); 387 lcp_lowerup(0); 388 lcp_open(0); /* Start protocol */ 389 for (phase = PHASE_ESTABLISH; phase != PHASE_DEAD; ) { 390 wait_input(timeleft(&timo)); 391 calltimeout(); 392 get_input(); 393 if (kill_link) { 394 lcp_close(0); 395 kill_link = 0; 396 } 397 if (open_ccp_flag) { 398 if (phase == PHASE_NETWORK) { 399 ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */ 400 ccp_open(0); 401 } 402 open_ccp_flag = 0; 403 } 404 reap_kids(); /* Don't leave dead kids lying around */ 405 } 406 407 /* 408 * Run disconnector script, if requested. 409 * First we need to reset non-blocking mode. 410 * XXX we may not be able to do this if the line has hung up! 411 */ 412 if (initfdflags != -1 && fcntl(fd, F_SETFL, initfdflags) >= 0) 413 initfdflags = -1; 414 disestablish_ppp(); 415 if (disconnector) { 416 set_up_tty(fd, 1); 417 if (device_script(disconnector, fd, fd) < 0) { 418 syslog(LOG_WARNING, "disconnect script failed"); 419 } else { 420 syslog(LOG_INFO, "Serial link disconnected."); 421 } 422 } 423 424 close_fd(); 425 if (unlink(pidfilename) < 0 && errno != ENOENT) 426 syslog(LOG_WARNING, "unable to delete pid file: %m"); 427 pidfilename[0] = 0; 428 429 } while (persist); 430 431 die(0); 432} 433 434 435/* 436 * get_input - called when incoming data is available. 437 */ 438static void 439get_input() 440{ 441 int len, i; 442 u_char *p; 443 u_short protocol; 444 445 p = inpacket_buf; /* point to beginning of packet buffer */ 446 447 len = read_packet(inpacket_buf); 448 if (len < 0) 449 return; 450 451 if (len == 0) { 452 syslog(LOG_NOTICE, "Modem hangup"); 453 hungup = 1; 454 lcp_lowerdown(0); /* serial link is no longer available */ 455 phase = PHASE_DEAD; 456 return; 457 } 458 459 if (debug /*&& (debugflags & DBG_INPACKET)*/) 460 log_packet(p, len, "rcvd "); 461 462 if (len < PPP_HDRLEN) { 463 MAINDEBUG((LOG_INFO, "io(): Received short packet.")); 464 return; 465 } 466 467 p += 2; /* Skip address and control */ 468 GETSHORT(protocol, p); 469 len -= PPP_HDRLEN; 470 471 /* 472 * Toss all non-LCP packets unless LCP is OPEN. 473 */ 474 if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) { 475 MAINDEBUG((LOG_INFO, 476 "io(): Received non-LCP packet when LCP not open.")); 477 return; 478 } 479 480 /* 481 * Upcall the proper protocol input routine. 482 */ 483 for (i = 0; i < sizeof (prottbl) / sizeof (struct protent); i++) { 484 if (prottbl[i].protocol == protocol) { 485 (*prottbl[i].input)(0, p, len); 486 return; 487 } 488 if (protocol == (prottbl[i].protocol & ~0x8000) 489 && prottbl[i].datainput != NULL) { 490 (*prottbl[i].datainput)(0, p, len); 491 return; 492 } 493 } 494 495 if (debug) 496 syslog(LOG_WARNING, "Unknown protocol (0x%x) received", protocol); 497 lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN); 498} 499 500 501/* 502 * demuxprotrej - Demultiplex a Protocol-Reject. 503 */ 504void 505demuxprotrej(unit, protocol) 506 int unit; 507 u_short protocol; 508{ 509 int i; 510 511 /* 512 * Upcall the proper Protocol-Reject routine. 513 */ 514 for (i = 0; i < sizeof (prottbl) / sizeof (struct protent); i++) 515 if (prottbl[i].protocol == protocol) { 516 (*prottbl[i].protrej)(unit); 517 return; 518 } 519 520 syslog(LOG_WARNING, 521 "demuxprotrej: Unrecognized Protocol-Reject for protocol 0x%x", 522 protocol); 523} 524 525 526/* 527 * bad_signal - We've caught a fatal signal. Clean up state and exit. 528 */ 529static void 530bad_signal(sig) 531 int sig; 532{ 533 syslog(LOG_ERR, "Fatal signal %d", sig); 534 die(1); 535} 536 537/* 538 * quit - Clean up state and exit (with an error indication). 539 */ 540void 541quit() 542{ 543 die(1); 544} 545 546/* 547 * die - like quit, except we can specify an exit status. 548 */ 549void 550die(status) 551 int status; 552{ 553 cleanup(0, NULL); 554 syslog(LOG_INFO, "Exit."); 555 exit(status); 556} 557 558/* 559 * cleanup - restore anything which needs to be restored before we exit 560 */ 561/* ARGSUSED */ 562void 563cleanup(status, arg) 564 int status; 565 caddr_t arg; 566{ 567 if (fd >= 0) 568 close_fd(); 569 570 if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT) 571 syslog(LOG_WARNING, "unable to delete pid file: %m"); 572 pidfilename[0] = 0; 573 574 if (lockflag && !default_device) 575 unlock(); 576} 577 578/* 579 * close_fd - restore the terminal device and close it. 580 */ 581void 582close_fd() 583{ 584 disestablish_ppp(); 585 sleep(1); 586 587 /* drop dtr to hang up */ 588 if (modem) { 589 setdtr(fd, FALSE); 590 sleep(1); 591 } 592 593 if (initfdflags != -1 && fcntl(fd, F_SETFL, initfdflags) < 0) 594 syslog(LOG_WARNING, "Couldn't restore device fd flags: %m"); 595 initfdflags = -1; 596 597 restore_tty(); 598 599 close(fd); 600 fd = -1; 601} 602 603 604struct callout { 605 struct timeval c_time; /* time at which to call routine */ 606 caddr_t c_arg; /* argument to routine */ 607 void (*c_func)(); /* routine */ 608 struct callout *c_next; 609}; 610 611static struct callout *callout = NULL; /* Callout list */ 612static struct timeval timenow; /* Current time */ 613 614/* 615 * timeout - Schedule a timeout. 616 * 617 * Note that this timeout takes the number of seconds, NOT hz (as in 618 * the kernel). 619 */ 620void 621timeout(func, arg, time) 622 void (*func)(); 623 caddr_t arg; 624 int time; 625{ 626 struct callout *newp, *p, **pp; 627 628 MAINDEBUG((LOG_DEBUG, "Timeout %lx:%lx in %d seconds.", 629 (long) func, (long) arg, time)); 630 631 /* 632 * Allocate timeout. 633 */ 634 if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL) { 635 syslog(LOG_ERR, "Out of memory in timeout()!"); 636 die(1); 637 } 638 newp->c_arg = arg; 639 newp->c_func = func; 640 gettimeofday(&timenow, NULL); 641 newp->c_time.tv_sec = timenow.tv_sec + time; 642 newp->c_time.tv_usec = timenow.tv_usec; 643 644 /* 645 * Find correct place and link it in. 646 */ 647 for (pp = &callout; (p = *pp); pp = &p->c_next) 648 if (newp->c_time.tv_sec < p->c_time.tv_sec 649 || (newp->c_time.tv_sec == p->c_time.tv_sec 650 && newp->c_time.tv_usec < p->c_time.tv_sec)) 651 break; 652 newp->c_next = p; 653 *pp = newp; 654} 655 656 657/* 658 * untimeout - Unschedule a timeout. 659 */ 660void 661untimeout(func, arg) 662 void (*func)(); 663 caddr_t arg; 664{ 665 struct itimerval itv; 666 struct callout **copp, *freep; 667 int reschedule = 0; 668 669 MAINDEBUG((LOG_DEBUG, "Untimeout %lx:%lx.", (long) func, (long) arg)); 670 671 /* 672 * Find first matching timeout and remove it from the list. 673 */ 674 for (copp = &callout; (freep = *copp); copp = &freep->c_next) 675 if (freep->c_func == func && freep->c_arg == arg) { 676 *copp = freep->c_next; 677 (void) free((char *) freep); 678 break; 679 } 680} 681 682 683/* 684 * calltimeout - Call any timeout routines which are now due. 685 */ 686void 687calltimeout() 688{ 689 struct callout *p; 690 691 while (callout != NULL) { 692 p = callout; 693 694 if (gettimeofday(&timenow, NULL) < 0) { 695 syslog(LOG_ERR, "Failed to get time of day: %m"); 696 die(1); 697 } 698 if (!(p->c_time.tv_sec < timenow.tv_sec 699 || (p->c_time.tv_sec == timenow.tv_sec 700 && p->c_time.tv_usec <= timenow.tv_usec))) 701 break; /* no, it's not time yet */ 702 703 callout = p->c_next; 704 (*p->c_func)(p->c_arg); 705 706 free((char *) p); 707 } 708} 709 710 711/* 712 * timeleft - return the length of time until the next timeout is due. 713 */ 714struct timeval * 715timeleft(tvp) 716 struct timeval *tvp; 717{ 718 if (callout == NULL) 719 return NULL; 720 721 gettimeofday(&timenow, NULL); 722 tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec; 723 tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec; 724 if (tvp->tv_usec < 0) { 725 tvp->tv_usec += 1000000; 726 tvp->tv_sec -= 1; 727 } 728 if (tvp->tv_sec < 0) 729 tvp->tv_sec = tvp->tv_usec = 0; 730 731 return tvp; 732} 733 734 735/* 736 * hup - Catch SIGHUP signal. 737 * 738 * Indicates that the physical layer has been disconnected. 739 * We don't rely on this indication; if the user has sent this 740 * signal, we just take the link down. 741 */ 742static void 743hup(sig) 744 int sig; 745{ 746 syslog(LOG_INFO, "Hangup (SIGHUP)"); 747 kill_link = 1; 748} 749 750 751/* 752 * term - Catch SIGTERM signal and SIGINT signal (^C/del). 753 * 754 * Indicates that we should initiate a graceful disconnect and exit. 755 */ 756/*ARGSUSED*/ 757static void 758term(sig) 759 int sig; 760{ 761 syslog(LOG_INFO, "Terminating on signal %d.", sig); 762 persist = 0; /* don't try to restart */ 763 kill_link = 1; 764} 765 766 767/* 768 * chld - Catch SIGCHLD signal. 769 * Calls reap_kids to get status for any dead kids. 770 */ 771static void 772chld(sig) 773 int sig; 774{ 775 reap_kids(); 776} 777 778 779/* 780 * toggle_debug - Catch SIGUSR1 signal. 781 * 782 * Toggle debug flag. 783 */ 784/*ARGSUSED*/ 785static void 786toggle_debug(sig) 787 int sig; 788{ 789 debug = !debug; 790 note_debug_level(); 791} 792 793 794/* 795 * open_ccp - Catch SIGUSR2 signal. 796 * 797 * Try to (re)negotiate compression. 798 */ 799/*ARGSUSED*/ 800static void 801open_ccp(sig) 802 int sig; 803{ 804 open_ccp_flag = 1; 805} 806 807 808/* 809 * device_script - run a program to connect or disconnect the 810 * serial device. 811 */ 812int 813device_script(program, in, out) 814 char *program; 815 int in, out; 816{ 817 int pid; 818 int status; 819 int errfd; 820 821 pid = fork(); 822 823 if (pid < 0) { 824 syslog(LOG_ERR, "Failed to create child process: %m"); 825 die(1); 826 } 827 828 if (pid == 0) { 829 dup2(in, 0); 830 dup2(out, 1); 831 errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0644); 832 if (errfd >= 0) 833 dup2(errfd, 2); 834 setuid(getuid()); 835 setgid(getgid()); 836 execl("/bin/sh", "sh", "-c", program, (char *)0); 837 syslog(LOG_ERR, "could not exec /bin/sh: %m"); 838 _exit(99); 839 /* NOTREACHED */ 840 } 841 842 while (waitpid(pid, &status, 0) < 0) { 843 if (errno == EINTR) 844 continue; 845 syslog(LOG_ERR, "error waiting for (dis)connection process: %m"); 846 die(1); 847 } 848 849 return (status == 0 ? 0 : -1); 850} 851 852 853/* 854 * run-program - execute a program with given arguments, 855 * but don't wait for it. 856 * If the program can't be executed, logs an error unless 857 * must_exist is 0 and the program file doesn't exist. 858 */ 859int 860run_program(prog, args, must_exist) 861 char *prog; 862 char **args; 863 int must_exist; 864{ 865 int pid; 866 char *nullenv[1]; 867 868 pid = fork(); 869 if (pid == -1) { 870 syslog(LOG_ERR, "Failed to create child process for %s: %m", prog); 871 return -1; 872 } 873 if (pid == 0) { 874 int new_fd; 875 876 /* Leave the current location */ 877 (void) setsid(); /* No controlling tty. */ 878 (void) umask (S_IRWXG|S_IRWXO); 879 (void) chdir ("/"); /* no current directory. */ 880 setuid(geteuid()); 881 setgid(getegid()); 882 883 /* Ensure that nothing of our device environment is inherited. */ 884 close (0); 885 close (1); 886 close (2); 887 close (fd); /* tty interface to the ppp device */ 888 /* XXX should call sysdep cleanup procedure here */ 889 890 /* Don't pass handles to the PPP device, even by accident. */ 891 new_fd = open (_PATH_DEVNULL, O_RDWR); 892 if (new_fd >= 0) { 893 if (new_fd != 0) { 894 dup2 (new_fd, 0); /* stdin <- /dev/null */ 895 close (new_fd); 896 } 897 dup2 (0, 1); /* stdout -> /dev/null */ 898 dup2 (0, 2); /* stderr -> /dev/null */ 899 } 900 901#ifdef BSD 902 /* Force the priority back to zero if pppd is running higher. */ 903 if (setpriority (PRIO_PROCESS, 0, 0) < 0) 904 syslog (LOG_WARNING, "can't reset priority to 0: %m"); 905#endif 906 907 /* SysV recommends a second fork at this point. */ 908 909 /* run the program; give it a null environment */ 910 nullenv[0] = NULL; 911 execve(prog, args, nullenv); 912 if (must_exist || errno != ENOENT) 913 syslog(LOG_WARNING, "Can't execute %s: %m", prog); 914 _exit(-1); 915 } 916 MAINDEBUG((LOG_DEBUG, "Script %s started; pid = %d", prog, pid)); 917 ++n_children; 918 return 0; 919} 920 921 922/* 923 * reap_kids - get status from any dead child processes, 924 * and log a message for abnormal terminations. 925 */ 926void 927reap_kids() 928{ 929 int pid, status; 930 931 if (n_children == 0) 932 return; 933 if ((pid = waitpid(-1, &status, WNOHANG)) == -1) { 934 if (errno != ECHILD) 935 syslog(LOG_ERR, "Error waiting for child process: %m"); 936 return; 937 } 938 if (pid > 0) { 939 --n_children; 940 if (WIFSIGNALED(status)) { 941 syslog(LOG_WARNING, "Child process %d terminated with signal %d", 942 pid, WTERMSIG(status)); 943 } 944 } 945} 946 947 948/* 949 * log_packet - format a packet and log it. 950 */ 951 952char line[256]; /* line to be logged accumulated here */ 953char *linep; 954 955void 956log_packet(p, len, prefix) 957 u_char *p; 958 int len; 959 char *prefix; 960{ 961 strcpy(line, prefix); 962 linep = line + strlen(line); 963 format_packet(p, len, pr_log, NULL); 964 if (linep != line) 965 syslog(LOG_DEBUG, "%s", line); 966} 967 968/* 969 * format_packet - make a readable representation of a packet, 970 * calling `printer(arg, format, ...)' to output it. 971 */ 972void 973format_packet(p, len, printer, arg) 974 u_char *p; 975 int len; 976 void (*printer) __P((void *, char *, ...)); 977 void *arg; 978{ 979 int i, n; 980 u_short proto; 981 u_char x; 982 983 if (len >= PPP_HDRLEN && p[0] == PPP_ALLSTATIONS && p[1] == PPP_UI) { 984 p += 2; 985 GETSHORT(proto, p); 986 len -= PPP_HDRLEN; 987 for (i = 0; i < N_PROTO; ++i) 988 if (proto == prottbl[i].protocol) 989 break; 990 if (i < N_PROTO) { 991 printer(arg, "[%s", prottbl[i].name); 992 n = (*prottbl[i].printpkt)(p, len, printer, arg); 993 printer(arg, "]"); 994 p += n; 995 len -= n; 996 } else { 997 printer(arg, "[proto=0x%x]", proto); 998 } 999 } 1000 1001 for (; len > 0; --len) { 1002 GETCHAR(x, p); 1003 printer(arg, " %.2x", x); 1004 } 1005} 1006 1007#ifdef __STDC__ 1008#include <stdarg.h> 1009 1010void 1011pr_log(void *arg, char *fmt, ...) 1012{ 1013 int n; 1014 va_list pvar; 1015 char buf[256]; 1016 1017 va_start(pvar, fmt); 1018 vsprintf(buf, fmt, pvar); 1019 va_end(pvar); 1020 1021 n = strlen(buf); 1022 if (linep + n + 1 > line + sizeof(line)) { 1023 syslog(LOG_DEBUG, "%s", line); 1024 linep = line; 1025 } 1026 strcpy(linep, buf); 1027 linep += n; 1028} 1029 1030#else /* __STDC__ */ 1031#include <varargs.h> 1032 1033void 1034pr_log(arg, fmt, va_alist) 1035void *arg; 1036char *fmt; 1037va_dcl 1038{ 1039 int n; 1040 va_list pvar; 1041 char buf[256]; 1042 1043 va_start(pvar); 1044 vsprintf(buf, fmt, pvar); 1045 va_end(pvar); 1046 1047 n = strlen(buf); 1048 if (linep + n + 1 > line + sizeof(line)) { 1049 syslog(LOG_DEBUG, "%s", line); 1050 linep = line; 1051 } 1052 strcpy(linep, buf); 1053 linep += n; 1054} 1055#endif 1056 1057/* 1058 * print_string - print a readable representation of a string using 1059 * printer. 1060 */ 1061void 1062print_string(p, len, printer, arg) 1063 char *p; 1064 int len; 1065 void (*printer) __P((void *, char *, ...)); 1066 void *arg; 1067{ 1068 int c; 1069 1070 printer(arg, "\""); 1071 for (; len > 0; --len) { 1072 c = *p++; 1073 if (' ' <= c && c <= '~') 1074 printer(arg, "%c", c); 1075 else 1076 printer(arg, "\\%.3o", c); 1077 } 1078 printer(arg, "\""); 1079} 1080 1081/* 1082 * novm - log an error message saying we ran out of memory, and die. 1083 */ 1084void 1085novm(msg) 1086 char *msg; 1087{ 1088 syslog(LOG_ERR, "Virtual memory exhausted allocating %s\n", msg); 1089 die(1); 1090} 1091