/* Serval Distributed Numbering Architecture (DNA) Copyright (C) 2010 Paul Gardner-Stephen This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include #include #include #include #include #include #include "serval.h" #include "conf.h" #include "strbuf.h" #include "strbuf_helpers.h" #define PIDFILE_NAME "servald.pid" #define STOPFILE_NAME "servald.stop" #define EXEC_NARGS 20 char *exec_args[EXEC_NARGS + 1]; int exec_argc = 0; int serverMode=0; int servalShutdown = 0; static int server_getpid = 0; void signal_handler(int signal); void crash_handler(int signal); int getKeyring(char *s); /** Return the PID of the currently running server process, return 0 if there is none. */ int server_pid() { const char *instancepath = serval_instancepath(); struct stat st; if (stat(instancepath, &st) == -1) { WHY_perror("stat"); return WHYF("Instance path '%s' non existant or not accessable" " (Set SERVALINSTANCE_PATH to specify an alternate location)", instancepath ); } if ((st.st_mode & S_IFMT) != S_IFDIR) return WHYF("Instance path '%s' is not a directory", instancepath); char filename[1024]; if (!FORM_SERVAL_INSTANCE_PATH(filename, PIDFILE_NAME)) return -1; FILE *f = NULL; if ((f = fopen(filename, "r"))) { char buf[20]; fgets(buf, sizeof buf, f); fclose(f); int pid = atoi(buf); if (pid > 0 && kill(pid, 0) != -1) return pid; INFOF("Unlinking stale pidfile %s", filename); unlink(filename); } return 0; } void server_save_argv(int argc, const char *const *argv) { /* Save our argv[] to use for relaunching */ for (exec_argc = 0; exec_argc < argc && exec_argc < EXEC_NARGS; ++exec_argc) exec_args[exec_argc] = strdup(argv[exec_argc]); exec_args[exec_argc] = NULL; } int server(char *backing_file) { /* For testing, it can be very helpful to delay the start of the server process, for example to check that the start/stop logic is robust. */ const char *delay = getenv("SERVALD_SERVER_START_DELAY"); if (delay) sleep_ms(atoi(delay)); serverMode = 1; /* Catch crash signals so that we can log a backtrace before expiring. */ struct sigaction sig; sig.sa_handler = crash_handler; sigemptyset(&sig.sa_mask); // Don't block any signals during handler sig.sa_flags = SA_NODEFER | SA_RESETHAND; // So the signal handler can kill the process by re-sending the same signal to itself sigaction(SIGSEGV, &sig, NULL); sigaction(SIGFPE, &sig, NULL); sigaction(SIGILL, &sig, NULL); sigaction(SIGBUS, &sig, NULL); sigaction(SIGABRT, &sig, NULL); /* Catch SIGHUP etc so that we can respond to requests to do things, eg, shut down. */ sig.sa_handler = signal_handler; sigemptyset(&sig.sa_mask); // Block the same signals during handler sigaddset(&sig.sa_mask, SIGHUP); sigaddset(&sig.sa_mask, SIGINT); sigaddset(&sig.sa_mask, SIGQUIT); sig.sa_flags = 0; sigaction(SIGHUP, &sig, NULL); sigaction(SIGINT, &sig, NULL); sigaction(SIGQUIT, &sig, NULL); /* Record PID to advertise that the server is now running */ char filename[1024]; if (!FORM_SERVAL_INSTANCE_PATH(filename, PIDFILE_NAME)) return -1; FILE *f=fopen(filename,"w"); if (!f) { WHY_perror("fopen"); WHYF("Could not write to PID file %s", filename); return -1; } server_getpid = getpid(); fprintf(f,"%d\n", server_getpid); fclose(f); overlayServerMode(); return 0; } /* Called periodically by the server process in its main loop. */ void server_shutdown_check(struct sched_ent *alarm) { if (servalShutdown) { INFO("Shutdown flag set -- terminating with cleanup"); serverCleanUp(); exit(0); } if (server_check_stopfile() == 1) { INFO("Shutdown file exists -- terminating with cleanup"); serverCleanUp(); exit(0); } /* If this server has been supplanted with another or Serval has been uninstalled, then its PID file will change or be unaccessible. In this case, shut down without all the cleanup. Perform this check at most once per second. */ static time_ms_t server_pid_time_ms = 0; time_ms_t now = gettime_ms(); if (server_pid_time_ms == 0 || now - server_pid_time_ms > 1000) { server_pid_time_ms = now; if (server_pid() != server_getpid) { WARNF("Server pid file no longer contains pid=%d -- shutting down without cleanup", server_getpid); exit(1); } } if (alarm){ alarm->alarm = now + 1000; alarm->deadline = alarm->alarm + 5000; schedule(alarm); } } int server_create_stopfile() { char stopfile[1024]; if (!FORM_SERVAL_INSTANCE_PATH(stopfile, STOPFILE_NAME)) return -1; FILE *f; if ((f = fopen(stopfile, "w")) == NULL) { WHY_perror("fopen"); return WHYF("Could not create stopfile '%s'", stopfile); } fclose(f); return 0; } int server_remove_stopfile() { char stopfile[1024]; if (!FORM_SERVAL_INSTANCE_PATH(stopfile, STOPFILE_NAME)) return -1; if (unlink(stopfile) == -1) { if (errno == ENOENT) return 0; WHY_perror("unlink"); return WHYF("Could not unlink stopfile '%s'", stopfile); } return 1; } int server_check_stopfile() { char stopfile[1024]; if (!FORM_SERVAL_INSTANCE_PATH(stopfile, STOPFILE_NAME)) return -1; int r = access(stopfile, F_OK); if (r == 0) return 1; if (r == -1 && errno == ENOENT) return 0; WHY_perror("access"); WHYF("Cannot access stopfile '%s'", stopfile); return -1; } void serverCleanUp() { /* Try to remove shutdown and PID files and exit */ server_remove_stopfile(); char filename[1024]; if (FORM_SERVAL_INSTANCE_PATH(filename, PIDFILE_NAME)) unlink(filename); if (FORM_SERVAL_INSTANCE_PATH(filename, "mdp.socket")) { unlink(filename); } dna_helper_shutdown(); } static void signame(char *buf, size_t len, int signal) { const char *desc = ""; switch(signal) { #ifdef SIGHUP case SIGHUP: desc = "HUP"; break; #endif #ifdef SIGINT case SIGINT: desc = "INT"; break; #endif #ifdef SIGQUIT case SIGQUIT: desc = "QUIT"; break; #endif #ifdef SIGILL case SIGILL: desc = "ILL (not reset when caught)"; break; #endif #ifdef SIGTRAP case SIGTRAP: desc = "TRAP (not reset when caught)"; break; #endif #ifdef SIGABRT case SIGABRT: desc = "ABRT"; break; #endif #ifdef SIGPOLL case SIGPOLL: desc = "POLL ([XSR] generated, not supported)"; break; #endif #ifdef SIGEMT case SIGEMT: desc = "EMT"; break; #endif #ifdef SIGFPE case SIGFPE: desc = "FPE"; break; #endif #ifdef SIGKILL case SIGKILL: desc = "KILL (cannot be caught or ignored)"; break; #endif #ifdef SIGBUS case SIGBUS: desc = "BUS"; break; #endif #ifdef SIGSEGV case SIGSEGV: desc = "SEGV"; break; #endif #ifdef SIGSYS case SIGSYS: desc = "SYS"; break; #endif #ifdef SIGPIPE case SIGPIPE: desc = "PIPE"; break; #endif #ifdef SIGALRM case SIGALRM: desc = "ALRM"; break; #endif #ifdef SIGTERM case SIGTERM: desc = "TERM"; break; #endif #ifdef SIGURG case SIGURG: desc = "URG"; break; #endif #ifdef SIGSTOP case SIGSTOP: desc = "STOP"; break; #endif #ifdef SIGTSTP case SIGTSTP: desc = "TSTP"; break; #endif #ifdef SIGCONT case SIGCONT: desc = "CONT"; break; #endif #ifdef SIGCHLD case SIGCHLD: desc = "CHLD"; break; #endif #ifdef SIGTTIN case SIGTTIN: desc = "TTIN"; break; #endif #ifdef SIGTTOU case SIGTTOU: desc = "TTOU"; break; #endif #ifdef SIGIO #if SIGIO != SIGPOLL case SIGIO: desc = "IO"; break; #endif #endif #ifdef SIGXCPU case SIGXCPU: desc = "XCPU"; break; #endif #ifdef SIGXFSZ case SIGXFSZ: desc = "XFSZ"; break; #endif #ifdef SIGVTALRM case SIGVTALRM: desc = "VTALRM"; break; #endif #ifdef SIGPROF case SIGPROF: desc = "PROF"; break; #endif #ifdef SIGWINCH case SIGWINCH: desc = "WINCH"; break; #endif #ifdef SIGINFO case SIGINFO: desc = "INFO"; break; #endif #ifdef SIGUSR1 case SIGUSR1: desc = "USR1"; break; #endif #ifdef SIGUSR2 case SIGUSR2: desc = "USR2"; break; #endif } snprintf(buf, len, "SIG%s (%d) %s", desc, signal, strsignal(signal)); buf[len - 1] = '\0'; } void signal_handler(int signal) { char buf[80]; signame(buf, sizeof(buf), signal); INFOF("Caught %s", buf); switch (signal) { case SIGHUP: case SIGINT: /* Terminate the server process. The shutting down should be done from the main-line code rather than here, so we first try to tell the mainline code to do so. If, however, this is not the first time we have been asked to shut down, then we will do it here. */ server_shutdown_check(NULL); WHY("Asking Serval process to shutdown cleanly"); servalShutdown = 1; return; } serverCleanUp(); exit(0); } void crash_handler(int signal) { char buf[80]; signame(buf, sizeof(buf), signal); WHYF("Caught %s", buf); dump_stack(); BACKTRACE; if (config.server.respawn_on_crash) { int i; for(i=0;i-1) close(overlay_interfaces[i].alarm.poll.fd); char execpath[160]; if (get_self_executable_path(execpath, sizeof execpath) != -1) { strbuf b = strbuf_alloca(1024); for (i = 0; i < exec_argc; ++i) strbuf_append_shell_quotemeta(strbuf_puts(b, i ? " " : ""), exec_args[i]); INFOF("Respawning %s as %s", execpath, strbuf_str(b)); execv(execpath, exec_args); /* Quit if the exec() fails */ WHY_perror("execv"); } else { WHY("Cannot respawn"); } } // Now die of the same signal, so that our exit status reflects the cause. INFOF("Re-sending signal %d to self", signal); kill(getpid(), signal); // If that didn't work, then die normally. INFOF("exit(%d)", -signal); exit(-signal); } int getKeyring(char *backing_file) { if (!backing_file) { exit(WHY("Keyring requires a backing file")); } else { if (keyring) exit(WHY("Keyring being opened twice")); keyring=keyring_open(backing_file); /* unlock all entries with blank pins */ keyring_enter_pins(keyring,""); } keyring_seed(keyring); return 0; }