diff options
Diffstat (limited to 'usr.sbin/mrouted/main.c')
| -rw-r--r-- | usr.sbin/mrouted/main.c | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/usr.sbin/mrouted/main.c b/usr.sbin/mrouted/main.c new file mode 100644 index 000000000000..75809dc478e3 --- /dev/null +++ b/usr.sbin/mrouted/main.c @@ -0,0 +1,322 @@ +/* + * The mrouted program is covered by the license in the accompanying file + * named "LICENSE". Use of the mrouted program represents acceptance of + * the terms and conditions listed in that file. + * + * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of + * Leland Stanford Junior University. + * + * + * $Id: main.c,v 1.1.1.1 1994/05/17 20:59:33 jkh Exp $ + */ + +/* + * Written by Steve Deering, Stanford University, February 1989. + * + * (An earlier version of DVMRP was implemented by David Waitzman of + * BBN STC by extending Berkeley's routed program. Some of Waitzman's + * extensions have been incorporated into mrouted, but none of the + * original routed code has been adopted.) + */ + + +#include "defs.h" + +extern char *configfilename; + +static char pidfilename[] = "/etc/mrouted.pid"; +static char dumpfilename[] = "/usr/tmp/mrouted.dump"; + +static int debug = 0; + + +/* + * Forward declarations. + */ +static void timer(); +static void hup(); +static void dump(); +static void fdump(); + + +main(argc, argv) + int argc; + char *argv[]; +{ + register int recvlen; + register int omask; + int dummy; + FILE *fp; + extern uid_t geteuid(); + + setlinebuf(stderr); + + if (geteuid() != 0) { + fprintf(stderr, "mrouted: must be root\n"); + exit(1); + } + + argv++, argc--; + while (argc > 0 && *argv[0] == '-') { + if (strcmp(*argv, "-d") == 0) { + if (argc > 1 && isdigit(*(argv + 1)[0])) { + argv++, argc--; + debug = atoi(*argv); + } else + debug = DEFAULT_DEBUG; + } else if (strcmp(*argv, "-c") == 0) { + if (argc > 1) { + argv++, argc--; + configfilename = *argv; + } else + goto usage; + } else + goto usage; + argv++, argc--; + } + + if (argc > 0) { +usage: fprintf(stderr, "usage: mrouted [-c configfile] [-d [debug_level]]\n"); + exit(1); + } + + if (debug == 0) { + /* + * Detach from the terminal + */ + int t; + + if (fork()) exit(0); + (void)close(0); + (void)close(1); + (void)close(2); + (void)open("/", 0); + (void)dup2(0, 1); + (void)dup2(0, 2); + t = open("/dev/tty", 2); + if (t >= 0) { + (void)ioctl(t, TIOCNOTTY, (char *)0); + (void)close(t); + } + } + else fprintf(stderr, "debug level %u\n", debug); + +#ifdef LOG_DAEMON + (void)openlog("mrouted", LOG_PID, LOG_DAEMON); + (void)setlogmask(LOG_UPTO(LOG_NOTICE)); +#else + (void)openlog("mrouted", LOG_PID); +#endif + log(LOG_NOTICE, 0, "mrouted version %d.%d", + PROTOCOL_VERSION, MROUTED_VERSION); + + fp = fopen(pidfilename, "w"); + if (fp != NULL) { + fprintf(fp, "%d\n", getpid()); + (void) fclose(fp); + } + + srandom(gethostid()); + + init_igmp(); + k_init_dvmrp(); /* enable DVMRP routing in kernel */ + init_routes(); + init_vifs(); + + if (debug >= 2) dump(); + + (void)signal(SIGALRM, timer); + (void)signal(SIGHUP, hup); + (void)signal(SIGTERM, hup); + (void)signal(SIGINT, hup); + (void)signal(SIGUSR1, fdump); + if (debug != 0) + (void)signal(SIGQUIT, dump); + + (void)alarm(TIMER_INTERVAL); /* schedule first timer interrupt */ + + /* + * Main receive loop. + */ + dummy = 0; + for(;;) { + recvlen = recvfrom(igmp_socket, recv_buf, sizeof(recv_buf), + 0, NULL, &dummy); + if (recvlen < 0) { + if (errno != EINTR) log(LOG_ERR, errno, "recvfrom"); + continue; + } + omask = sigblock(sigmask(SIGALRM)); + accept_igmp(recvlen); + (void)sigsetmask(omask); + } +} + + +/* + * The 'virtual_time' variable is initialized to a value that will cause the + * first invocation of timer() to send a probe or route report to all vifs + * and send group membership queries to all subnets for which this router is + * querier. This first invocation occurs approximately TIMER_INTERVAL seconds + * after the router starts up. Note that probes for neighbors and queries + * for group memberships are also sent at start-up time, as part of initial- + * ization. This repetition after a short interval is desirable for quickly + * building up topology and membership information in the presence of possible + * packet loss. + * + * 'virtual_time' advances at a rate that is only a crude approximation of + * real time, because it does not take into account any time spent processing, + * and because the timer intervals are sometimes shrunk by a random amount to + * avoid unwanted synchronization with other routers. + */ + +static u_long virtual_time = 0; + + +/* + * Timer routine. Performs periodic neighbor probing, route reporting, and + * group querying duties, and drives various timers in routing entries and + * virtual interface data structures. + */ +static void timer() +{ + int next_interval; + + age_routes(); /* Advance the timers in the route entries */ + age_vifs(); /* Advance the timers for neighbors and groups */ + + if (virtual_time % GROUP_QUERY_INTERVAL == 0) { + /* + * Time to query the local group memberships on all subnets + * for which this router is the elected querier. + */ + query_groups(); + } + + if (virtual_time % NEIGHBOR_PROBE_INTERVAL == 0) { + /* + * Time to send a probe on all vifs from which no neighbors have + * been heard. Also, check if any inoperative interfaces have now + * come up. (If they have, they will also be probed as part of + * their initialization.) + */ + probe_for_neighbors(); + + if (vifs_down) + check_vif_state(); + } + + delay_change_reports = FALSE; + next_interval = TIMER_INTERVAL; + + if (virtual_time % ROUTE_REPORT_INTERVAL == 0) { + /* + * Time for the periodic report of all routes to all neighbors. + */ + report_to_all_neighbors(ALL_ROUTES); + + /* + * Schedule the next timer interrupt for a random time between + * 1 and TIMER_INTERVAL seconds from now. This randomization is + * intended to counteract the undesirable synchronizing tendency + * of periodic transmissions from multiple sources. + */ + next_interval = (random() % TIMER_INTERVAL) + 1; + } + else if (routes_changed) { + /* + * Some routes have changed since the last timer interrupt, but + * have not been reported yet. Report the changed routes to all + * neighbors. + */ + report_to_all_neighbors(CHANGED_ROUTES); + } + + /* + * Advance virtual time and schedule the next timer interrupt. + */ + virtual_time += TIMER_INTERVAL; + (void)alarm(next_interval); +} + + +/* + * On hangup signal, let everyone know we're going away. + */ +static void hup() +{ + log(LOG_INFO, 0, "hup"); + expire_all_routes(); + report_to_all_neighbors(ALL_ROUTES); + exit(1); +} + + +/* + * Dump internal data structures to stderr. + */ +static void dump() +{ + dump_vifs(stderr); + dump_routes(stderr); +} + + +/* + * Dump internal data structures to a file. + */ +static void fdump() +{ + FILE *fp; + + fp = fopen(dumpfilename, "w"); + if (fp != NULL) { + dump_vifs(fp); + dump_routes(fp); + (void) fclose(fp); + } +} + + +/* + * Log errors and other messages to the system log daemon and to stderr, + * according to the severity of the message and the current debug level. + * For errors of severity LOG_ERR or worse, terminate the program. + */ +void log(severity, syserr, format, a, b, c, d, e) + int severity, syserr; + char *format; + int a, b, c, d, e; +{ + char fmt[100]; + + switch (debug) { + case 0: break; + case 1: if (severity > LOG_NOTICE) break; + case 2: if (severity > LOG_INFO ) break; + default: + fmt[0] = '\0'; + if (severity == LOG_WARNING) strcat(fmt, "warning - "); + strncat(fmt, format, 80); + fprintf(stderr, fmt, a, b, c, d, e); + if (syserr == 0) + fprintf(stderr, "\n"); + else if(syserr < sys_nerr) + fprintf(stderr, ": %s\n", sys_errlist[syserr]); + else + fprintf(stderr, ": errno %d\n", syserr); + } + + if (severity <= LOG_NOTICE) { + fmt[0] = '\0'; + if (severity == LOG_WARNING) strcat(fmt, "warning - "); + strncat(fmt, format, 80); + if (syserr != 0) { + strcat(fmt, ": %m"); + errno = syserr; + } + syslog(severity, fmt, a, b, c, d, e); + + if (severity <= LOG_ERR) exit(-1); + } +} |