+ struct sigaction sa;
+ sigset_t mask;
+
+ /*
+ * Compute mask of all interesting signals and install signal handlers
+ * for each. Only one signal handler may be active at a time. Therefore,
+ * all other signals should be masked when any handler is executing.
+ */
+ sigemptyset(&mask);
+ sigaddset(&mask, SIGHUP);
+ sigaddset(&mask, SIGINT);
+ sigaddset(&mask, SIGTERM);
+ sigaddset(&mask, SIGCHLD);
+ sigaddset(&mask, SIGUSR2);
+
+#define SIGNAL(s, handler) do { \
+ sa.sa_handler = handler; \
+ if (sigaction(s, &sa, NULL) < 0) \
+ fatal("Couldn't establish signal handler (%d): %m", s); \
+ } while (0)
+
+ sa.sa_mask = mask;
+ sa.sa_flags = 0;
+ SIGNAL(SIGHUP, hup); /* Hangup */
+ SIGNAL(SIGINT, term); /* Interrupt */
+ SIGNAL(SIGTERM, term); /* Terminate */
+ SIGNAL(SIGCHLD, chld);
+
+ SIGNAL(SIGUSR1, toggle_debug); /* Toggle debug flag */
+ SIGNAL(SIGUSR2, open_ccp); /* Reopen CCP */
+
+ /*
+ * Install a handler for other signals which would otherwise
+ * cause pppd to exit without cleaning up.
+ */
+ SIGNAL(SIGABRT, bad_signal);
+ SIGNAL(SIGALRM, bad_signal);
+ SIGNAL(SIGFPE, bad_signal);
+ SIGNAL(SIGILL, bad_signal);
+ SIGNAL(SIGPIPE, bad_signal);
+ SIGNAL(SIGQUIT, bad_signal);
+ SIGNAL(SIGSEGV, bad_signal);
+#ifdef SIGBUS
+ SIGNAL(SIGBUS, bad_signal);
+#endif
+#ifdef SIGEMT
+ SIGNAL(SIGEMT, bad_signal);
+#endif
+#ifdef SIGPOLL
+ SIGNAL(SIGPOLL, bad_signal);
+#endif
+#ifdef SIGPROF
+ SIGNAL(SIGPROF, bad_signal);
+#endif
+#ifdef SIGSYS
+ SIGNAL(SIGSYS, bad_signal);
+#endif
+#ifdef SIGTRAP
+ SIGNAL(SIGTRAP, bad_signal);
+#endif
+#ifdef SIGVTALRM
+ SIGNAL(SIGVTALRM, bad_signal);
+#endif
+#ifdef SIGXCPU
+ SIGNAL(SIGXCPU, bad_signal);
+#endif
+#ifdef SIGXFSZ
+ SIGNAL(SIGXFSZ, bad_signal);
+#endif
+
+ /*
+ * Apparently we can get a SIGPIPE when we call syslog, if
+ * syslogd has died and been restarted. Ignoring it seems
+ * be sufficient.
+ */
+ signal(SIGPIPE, SIG_IGN);
+}
+
+/*
+ * set_ifunit - do things we need to do once we know which ppp
+ * unit we are using.
+ */
+void
+set_ifunit(iskey)
+ int iskey;
+{
+ info("Using interface %s%d", PPP_DRV_NAME, ifunit);
+ slprintf(ifname, sizeof(ifname), "%s%d", PPP_DRV_NAME, ifunit);
+ script_setenv("IFNAME", ifname, iskey);
+ if (iskey) {
+ create_pidfile(); /* write pid to file */
+ create_linkpidfile();
+ }
+}
+
+/*
+ * detach - detach us from the controlling terminal.
+ */
+void
+detach()
+{
+ int pid;
+ char numbuf[16];
+
+ if (detached)
+ return;
+ if ((pid = fork()) < 0) {
+ error("Couldn't detach (fork failed: %m)");
+ die(1); /* or just return? */
+ }
+ if (pid != 0) {
+ /* parent */
+ notify(pidchange, pid);
+ exit(0); /* parent dies */
+ }
+ setsid();
+ chdir("/");
+ close(0);
+ close(1);
+ close(2);
+ detached = 1;
+ if (!log_to_file && !log_to_specific_fd)
+ log_to_fd = -1;
+ /* update pid files if they have been written already */
+ if (pidfilename[0])
+ create_pidfile();
+ if (linkpidfile[0])
+ create_linkpidfile();
+ slprintf(numbuf, sizeof(numbuf), "%d", getpid());
+ script_setenv("PPPD_PID", numbuf, 1);
+}
+
+/*
+ * reopen_log - (re)open our connection to syslog.
+ */
+void
+reopen_log()
+{
+#ifdef ULTRIX
+ openlog("pppd", LOG_PID);
+#else
+ openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
+ setlogmask(LOG_UPTO(LOG_INFO));
+#endif
+}
+
+/*
+ * Create a file containing our process ID.
+ */
+static void
+create_pidfile()
+{
+ FILE *pidfile;
+
+ slprintf(pidfilename, sizeof(pidfilename), "%s%s.pid",
+ _PATH_VARRUN, ifname);
+ if ((pidfile = fopen(pidfilename, "w")) != NULL) {
+ fprintf(pidfile, "%d\n", getpid());
+ (void) fclose(pidfile);
+ } else {
+ error("Failed to create pid file %s: %m", pidfilename);
+ pidfilename[0] = 0;
+ }
+}
+
+static void
+create_linkpidfile()
+{
+ FILE *pidfile;
+
+ if (linkname[0] == 0)
+ return;
+ script_setenv("LINKNAME", linkname, 1);
+ slprintf(linkpidfile, sizeof(linkpidfile), "%sppp-%s.pid",
+ _PATH_VARRUN, linkname);
+ if ((pidfile = fopen(linkpidfile, "w")) != NULL) {
+ fprintf(pidfile, "%d\n", getpid());
+ if (ifname[0])
+ fprintf(pidfile, "%s\n", ifname);
+ (void) fclose(pidfile);
+ } else {
+ error("Failed to create pid file %s: %m", linkpidfile);
+ linkpidfile[0] = 0;
+ }
+}
+
+/*
+ * holdoff_end - called via a timeout when the holdoff period ends.
+ */
+static void
+holdoff_end(arg)
+ void *arg;
+{
+ new_phase(PHASE_DORMANT);
+}
+
+/* List of protocol names, to make our messages a little more informative. */
+struct protocol_list {
+ u_short proto;
+ const char *name;
+} protocol_list[] = {
+ { 0x21, "IP" },
+ { 0x23, "OSI Network Layer" },
+ { 0x25, "Xerox NS IDP" },
+ { 0x27, "DECnet Phase IV" },
+ { 0x29, "Appletalk" },
+ { 0x2b, "Novell IPX" },
+ { 0x2d, "VJ compressed TCP/IP" },
+ { 0x2f, "VJ uncompressed TCP/IP" },
+ { 0x31, "Bridging PDU" },
+ { 0x33, "Stream Protocol ST-II" },
+ { 0x35, "Banyan Vines" },
+ { 0x39, "AppleTalk EDDP" },
+ { 0x3b, "AppleTalk SmartBuffered" },
+ { 0x3d, "Multi-Link" },
+ { 0x3f, "NETBIOS Framing" },
+ { 0x41, "Cisco Systems" },
+ { 0x43, "Ascom Timeplex" },
+ { 0x45, "Fujitsu Link Backup and Load Balancing (LBLB)" },
+ { 0x47, "DCA Remote Lan" },
+ { 0x49, "Serial Data Transport Protocol (PPP-SDTP)" },
+ { 0x4b, "SNA over 802.2" },
+ { 0x4d, "SNA" },
+ { 0x4f, "IP6 Header Compression" },
+ { 0x6f, "Stampede Bridging" },
+ { 0xfb, "single-link compression" },
+ { 0xfd, "1st choice compression" },
+ { 0x0201, "802.1d Hello Packets" },
+ { 0x0203, "IBM Source Routing BPDU" },
+ { 0x0205, "DEC LANBridge100 Spanning Tree" },
+ { 0x0231, "Luxcom" },
+ { 0x0233, "Sigma Network Systems" },
+ { 0x8021, "Internet Protocol Control Protocol" },
+ { 0x8023, "OSI Network Layer Control Protocol" },
+ { 0x8025, "Xerox NS IDP Control Protocol" },
+ { 0x8027, "DECnet Phase IV Control Protocol" },
+ { 0x8029, "Appletalk Control Protocol" },
+ { 0x802b, "Novell IPX Control Protocol" },
+ { 0x8031, "Bridging NCP" },
+ { 0x8033, "Stream Protocol Control Protocol" },
+ { 0x8035, "Banyan Vines Control Protocol" },
+ { 0x803d, "Multi-Link Control Protocol" },
+ { 0x803f, "NETBIOS Framing Control Protocol" },
+ { 0x8041, "Cisco Systems Control Protocol" },
+ { 0x8043, "Ascom Timeplex" },
+ { 0x8045, "Fujitsu LBLB Control Protocol" },
+ { 0x8047, "DCA Remote Lan Network Control Protocol (RLNCP)" },
+ { 0x8049, "Serial Data Control Protocol (PPP-SDCP)" },
+ { 0x804b, "SNA over 802.2 Control Protocol" },
+ { 0x804d, "SNA Control Protocol" },
+ { 0x804f, "IP6 Header Compression Control Protocol" },
+ { 0x006f, "Stampede Bridging Control Protocol" },
+ { 0x80fb, "Single Link Compression Control Protocol" },
+ { 0x80fd, "Compression Control Protocol" },
+ { 0xc021, "Link Control Protocol" },
+ { 0xc023, "Password Authentication Protocol" },
+ { 0xc025, "Link Quality Report" },
+ { 0xc027, "Shiva Password Authentication Protocol" },
+ { 0xc029, "CallBack Control Protocol (CBCP)" },
+ { 0xc081, "Container Control Protocol" },
+ { 0xc223, "Challenge Handshake Authentication Protocol" },
+ { 0xc281, "Proprietary Authentication Protocol" },
+ { 0, NULL },
+};
+
+/*
+ * protocol_name - find a name for a PPP protocol.
+ */
+const char *
+protocol_name(proto)
+ int proto;
+{
+ struct protocol_list *lp;
+
+ for (lp = protocol_list; lp->proto != 0; ++lp)
+ if (proto == lp->proto)
+ return lp->name;
+ return NULL;
+}