/* $Id$ */ /*** This file is part of avahi. avahi is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. avahi 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with avahi; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. ***/ #ifdef HAVE_CONFIG_H #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_INOTIFY #ifdef HAVE_SYS_INOTIFY_H #include #else #include "inotify-nosys.h" #endif #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef ENABLE_CHROOT #include "chroot.h" #include "caps.h" #endif #include "setproctitle.h" #include "main.h" #include "simple-protocol.h" #include "static-services.h" #include "static-hosts.h" #include "ini-file-parser.h" #ifdef HAVE_DBUS #include "dbus-protocol.h" #endif AvahiServer *avahi_server = NULL; AvahiSimplePoll *simple_poll_api = NULL; static char *argv0 = NULL; int nss_support = 0; typedef enum { DAEMON_RUN, DAEMON_KILL, DAEMON_VERSION, DAEMON_HELP, DAEMON_RELOAD, DAEMON_CHECK } DaemonCommand; typedef struct { AvahiServerConfig server_config; DaemonCommand command; int daemonize; int use_syslog; char *config_file; #ifdef HAVE_DBUS int enable_dbus; int fail_on_missing_dbus; #endif int drop_root; int set_rlimits; #ifdef ENABLE_CHROOT int use_chroot; #endif int modify_proc_title; int disable_user_service_publishing; int publish_resolv_conf; char ** publish_dns_servers; int debug; int rlimit_as_set, rlimit_core_set, rlimit_data_set, rlimit_fsize_set, rlimit_nofile_set, rlimit_stack_set; rlim_t rlimit_as, rlimit_core, rlimit_data, rlimit_fsize, rlimit_nofile, rlimit_stack; #ifdef RLIMIT_NPROC int rlimit_nproc_set; rlim_t rlimit_nproc; #endif } DaemonConfig; #define RESOLV_CONF "/etc/resolv.conf" static AvahiSEntryGroup *dns_servers_entry_group = NULL; static AvahiSEntryGroup *resolv_conf_entry_group = NULL; static char **resolv_conf = NULL; static DaemonConfig config; static int has_prefix(const char *s, const char *prefix) { size_t l; l = strlen(prefix); return strlen(s) >= l && strncmp(s, prefix, l) == 0; } static int load_resolv_conf(void) { int ret = -1; FILE *f; int i = 0; avahi_strfreev(resolv_conf); resolv_conf = NULL; #ifdef ENABLE_CHROOT f = avahi_chroot_helper_get_file(RESOLV_CONF); #else f = fopen(RESOLV_CONF, "r"); #endif if (!f) { avahi_log_warn("Failed to open "RESOLV_CONF": %s", strerror(errno)); goto finish; } resolv_conf = avahi_new0(char*, AVAHI_WIDE_AREA_SERVERS_MAX+1); while (!feof(f) && i < AVAHI_WIDE_AREA_SERVERS_MAX) { char ln[128]; char *p; if (!(fgets(ln, sizeof(ln), f))) break; ln[strcspn(ln, "\r\n#")] = 0; p = ln + strspn(ln, "\t "); if (has_prefix(p, "nameserver")) { p += 10; p += strspn(p, "\t "); p[strcspn(p, "\t ")] = 0; resolv_conf[i++] = avahi_strdup(p); } } ret = 0; finish: if (ret != 0) { avahi_strfreev(resolv_conf); resolv_conf = NULL; } if (f) fclose(f); return ret; } static AvahiSEntryGroup* add_dns_servers(AvahiServer *s, AvahiSEntryGroup* g, char **l) { char **p; assert(s); assert(l); if (!g) g = avahi_s_entry_group_new(s, NULL, NULL); assert(avahi_s_entry_group_is_empty(g)); for (p = l; *p; p++) { AvahiAddress a; if (!avahi_address_parse(*p, AVAHI_PROTO_UNSPEC, &a)) avahi_log_warn("Failed to parse address '%s', ignoring.", *p); else if (avahi_server_add_dns_server_address(s, g, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, 0, NULL, AVAHI_DNS_SERVER_RESOLVE, &a, 53) < 0) { avahi_s_entry_group_free(g); avahi_log_error("Failed to add DNS server address: %s", avahi_strerror(avahi_server_errno(s))); return NULL; } } avahi_s_entry_group_commit(g); return g; } static void remove_dns_server_entry_groups(void) { if (resolv_conf_entry_group) avahi_s_entry_group_reset(resolv_conf_entry_group); if (dns_servers_entry_group) avahi_s_entry_group_reset(dns_servers_entry_group); } static void update_wide_area_servers(void) { AvahiAddress a[AVAHI_WIDE_AREA_SERVERS_MAX]; unsigned n = 0; char **p; if (!resolv_conf) { avahi_server_set_wide_area_servers(avahi_server, NULL, 0); return; } for (p = resolv_conf; *p && n < AVAHI_WIDE_AREA_SERVERS_MAX; p++) { if (!avahi_address_parse(*p, AVAHI_PROTO_UNSPEC, &a[n])) avahi_log_warn("Failed to parse address '%s', ignoring.", *p); else n++; } avahi_server_set_wide_area_servers(avahi_server, a, n); } static void server_callback(AvahiServer *s, AvahiServerState state, void *userdata) { DaemonConfig *c = userdata; assert(s); assert(c); /* This function is possibly called before the global variable * avahi_server has been set, therefore we do it explicitly */ avahi_server = s; #ifdef HAVE_DBUS if (c->enable_dbus && state != AVAHI_SERVER_INVALID && state != AVAHI_SERVER_FAILURE) dbus_protocol_server_state_changed(state); #endif switch (state) { case AVAHI_SERVER_RUNNING: avahi_log_info("Server startup complete. Host name is %s. Local service cookie is %u.", avahi_server_get_host_name_fqdn(s), avahi_server_get_local_service_cookie(s)); avahi_set_proc_title(argv0, "%s: running [%s]", argv0, avahi_server_get_host_name_fqdn(s)); static_service_add_to_server(); static_hosts_add_to_server(); remove_dns_server_entry_groups(); if (c->publish_resolv_conf && resolv_conf && resolv_conf[0]) resolv_conf_entry_group = add_dns_servers(s, resolv_conf_entry_group, resolv_conf); if (c->publish_dns_servers && c->publish_dns_servers[0]) dns_servers_entry_group = add_dns_servers(s, dns_servers_entry_group, c->publish_dns_servers); simple_protocol_restart_queries(); break; case AVAHI_SERVER_COLLISION: { char *n; avahi_set_proc_title(argv0, "%s: collision", argv0); static_service_remove_from_server(); static_hosts_remove_from_server(); remove_dns_server_entry_groups(); n = avahi_alternative_host_name(avahi_server_get_host_name(s)); avahi_log_warn("Host name conflict, retrying with <%s>", n); avahi_server_set_host_name(s, n); avahi_free(n); break; } case AVAHI_SERVER_FAILURE: avahi_log_error("Server error: %s", avahi_strerror(avahi_server_errno(s))); avahi_simple_poll_quit(simple_poll_api); break; case AVAHI_SERVER_REGISTERING: avahi_set_proc_title(argv0, "%s: registering [%s]", argv0, avahi_server_get_host_name_fqdn(s)); static_service_remove_from_server(); static_hosts_remove_from_server(); remove_dns_server_entry_groups(); break; case AVAHI_SERVER_INVALID: break; } } static void help(FILE *f) { fprintf(f, "%s [options]\n" " -h --help Show this help\n" " -D --daemonize Daemonize after startup (implies -s)\n" " -s --syslog Write log messages to syslog(3) instead of STDERR\n" " -k --kill Kill a running daemon\n" " -r --reload Request a running daemon to reload static services\n" " -c --check Return 0 if a daemon is already running\n" " -V --version Show version\n" " -f --file=FILE Load the specified configuration file instead of\n" " "AVAHI_CONFIG_FILE"\n" " --no-rlimits Don't enforce resource limits\n" " --no-drop-root Don't drop privileges\n" #ifdef ENABLE_CHROOT " --no-chroot Don't chroot()\n" #endif " --no-proc-title Don't modify process title\n" " --debug Increase verbosity\n", argv0); } static int parse_command_line(DaemonConfig *c, int argc, char *argv[]) { int o; enum { OPTION_NO_RLIMITS = 256, OPTION_NO_DROP_ROOT, #ifdef ENABLE_CHROOT OPTION_NO_CHROOT, #endif OPTION_NO_PROC_TITLE, OPTION_DEBUG }; static const struct option long_options[] = { { "help", no_argument, NULL, 'h' }, { "daemonize", no_argument, NULL, 'D' }, { "kill", no_argument, NULL, 'k' }, { "version", no_argument, NULL, 'V' }, { "file", required_argument, NULL, 'f' }, { "reload", no_argument, NULL, 'r' }, { "check", no_argument, NULL, 'c' }, { "syslog", no_argument, NULL, 's' }, { "no-rlimits", no_argument, NULL, OPTION_NO_RLIMITS }, { "no-drop-root", no_argument, NULL, OPTION_NO_DROP_ROOT }, #ifdef ENABLE_CHROOT { "no-chroot", no_argument, NULL, OPTION_NO_CHROOT }, #endif { "no-proc-title", no_argument, NULL, OPTION_NO_PROC_TITLE }, { "debug", no_argument, NULL, OPTION_DEBUG }, { NULL, 0, NULL, 0 } }; assert(c); while ((o = getopt_long(argc, argv, "hDkVf:rcs", long_options, NULL)) >= 0) { switch(o) { case 's': c->use_syslog = 1; break; case 'h': c->command = DAEMON_HELP; break; case 'D': c->daemonize = 1; break; case 'k': c->command = DAEMON_KILL; break; case 'V': c->command = DAEMON_VERSION; break; case 'f': avahi_free(c->config_file); c->config_file = avahi_strdup(optarg); break; case 'r': c->command = DAEMON_RELOAD; break; case 'c': c->command = DAEMON_CHECK; break; case OPTION_NO_RLIMITS: c->set_rlimits = 0; break; case OPTION_NO_DROP_ROOT: c->drop_root = 0; break; #ifdef ENABLE_CHROOT case OPTION_NO_CHROOT: c->use_chroot = 0; break; #endif case OPTION_NO_PROC_TITLE: c->modify_proc_title = 0; break; case OPTION_DEBUG: c->debug = 1; break; default: return -1; } } if (optind < argc) { fprintf(stderr, "Too many arguments\n"); return -1; } return 0; } static int is_yes(const char *s) { assert(s); return *s == 'y' || *s == 'Y' || *s == '1' || *s == 't' || *s == 'T'; } static int load_config_file(DaemonConfig *c) { int r = -1; AvahiIniFile *f; AvahiIniFileGroup *g; assert(c); if (!(f = avahi_ini_file_load(c->config_file ? c->config_file : AVAHI_CONFIG_FILE))) goto finish; for (g = f->groups; g; g = g->groups_next) { if (strcasecmp(g->name, "server") == 0) { AvahiIniFilePair *p; for (p = g->pairs; p; p = p->pairs_next) { if (strcasecmp(p->key, "host-name") == 0) { avahi_free(c->server_config.host_name); c->server_config.host_name = avahi_strdup(p->value); } else if (strcasecmp(p->key, "domain-name") == 0) { avahi_free(c->server_config.domain_name); c->server_config.domain_name = avahi_strdup(p->value); } else if (strcasecmp(p->key, "browse-domains") == 0) { char **e, **t; e = avahi_split_csv(p->value); for (t = e; *t; t++) { char cleaned[AVAHI_DOMAIN_NAME_MAX]; if (!avahi_normalize_name(*t, cleaned, sizeof(cleaned))) { avahi_log_error("Invalid domain name \"%s\" for key \"%s\" in group \"%s\"\n", *t, p->key, g->name); avahi_strfreev(e); goto finish; } c->server_config.browse_domains = avahi_string_list_add(c->server_config.browse_domains, cleaned); } avahi_strfreev(e); } else if (strcasecmp(p->key, "use-ipv4") == 0) c->server_config.use_ipv4 = is_yes(p->value); else if (strcasecmp(p->key, "use-ipv6") == 0) c->server_config.use_ipv6 = is_yes(p->value); else if (strcasecmp(p->key, "check-response-ttl") == 0) c->server_config.check_response_ttl = is_yes(p->value); else if (strcasecmp(p->key, "allow-point-to-point") == 0) c->server_config.allow_point_to_point = is_yes(p->value); else if (strcasecmp(p->key, "use-iff-running") == 0) c->server_config.use_iff_running = is_yes(p->value); else if (strcasecmp(p->key, "disallow-other-stacks") == 0) c->server_config.disallow_other_stacks = is_yes(p->value); #ifdef HAVE_DBUS else if (strcasecmp(p->key, "enable-dbus") == 0) { if (*(p->value) == 'w' || *(p->value) == 'W') { c->fail_on_missing_dbus = 0; c->enable_dbus = 1; } else if (*(p->value) == 'y' || *(p->value) == 'Y') { c->fail_on_missing_dbus = 1; c->enable_dbus = 1; } else { c->enable_dbus = 0; } } #endif else { avahi_log_error("Invalid configuration key \"%s\" in group \"%s\"\n", p->key, g->name); goto finish; } } } else if (strcasecmp(g->name, "publish") == 0) { AvahiIniFilePair *p; for (p = g->pairs; p; p = p->pairs_next) { if (strcasecmp(p->key, "publish-addresses") == 0) c->server_config.publish_addresses = is_yes(p->value); else if (strcasecmp(p->key, "publish-hinfo") == 0) c->server_config.publish_hinfo = is_yes(p->value); else if (strcasecmp(p->key, "publish-workstation") == 0) c->server_config.publish_workstation = is_yes(p->value); else if (strcasecmp(p->key, "publish-domain") == 0) c->server_config.publish_domain = is_yes(p->value); else if (strcasecmp(p->key, "publish-resolv-conf-dns-servers") == 0) c->publish_resolv_conf = is_yes(p->value); else if (strcasecmp(p->key, "disable-publishing") == 0) c->server_config.disable_publishing = is_yes(p->value); else if (strcasecmp(p->key, "disable-user-service-publishing") == 0) c->disable_user_service_publishing = is_yes(p->value); else if (strcasecmp(p->key, "add-service-cookie") == 0) c->server_config.add_service_cookie = is_yes(p->value); else if (strcasecmp(p->key, "publish-dns-servers") == 0) { avahi_strfreev(c->publish_dns_servers); c->publish_dns_servers = avahi_split_csv(p->value); } else if (strcasecmp(p->key, "publish-a-on-ipv6") == 0) c->server_config.publish_a_on_ipv6 = is_yes(p->value); else if (strcasecmp(p->key, "publish-aaaa-on-ipv4") == 0) c->server_config.publish_aaaa_on_ipv4 = is_yes(p->value); else { avahi_log_error("Invalid configuration key \"%s\" in group \"%s\"\n", p->key, g->name); goto finish; } } } else if (strcasecmp(g->name, "wide-area") == 0) { AvahiIniFilePair *p; for (p = g->pairs; p; p = p->pairs_next) { if (strcasecmp(p->key, "enable-wide-area") == 0) c->server_config.enable_wide_area = is_yes(p->value); else { avahi_log_error("Invalid configuration key \"%s\" in group \"%s\"\n", p->key, g->name); goto finish; } } } else if (strcasecmp(g->name, "reflector") == 0) { AvahiIniFilePair *p; for (p = g->pairs; p; p = p->pairs_next) { if (strcasecmp(p->key, "enable-reflector") == 0) c->server_config.enable_reflector = is_yes(p->value); else if (strcasecmp(p->key, "reflect-ipv") == 0) c->server_config.reflect_ipv = is_yes(p->value); else { avahi_log_error("Invalid configuration key \"%s\" in group \"%s\"\n", p->key, g->name); goto finish; } } } else if (strcasecmp(g->name, "rlimits") == 0) { AvahiIniFilePair *p; for (p = g->pairs; p; p = p->pairs_next) { if (strcasecmp(p->key, "rlimit-as") == 0) { c->rlimit_as_set = 1; c->rlimit_as = atoi(p->value); } else if (strcasecmp(p->key, "rlimit-core") == 0) { c->rlimit_core_set = 1; c->rlimit_core = atoi(p->value); } else if (strcasecmp(p->key, "rlimit-data") == 0) { c->rlimit_data_set = 1; c->rlimit_data = atoi(p->value); } else if (strcasecmp(p->key, "rlimit-fsize") == 0) { c->rlimit_fsize_set = 1; c->rlimit_fsize = atoi(p->value); } else if (strcasecmp(p->key, "rlimit-nofile") == 0) { c->rlimit_nofile_set = 1; c->rlimit_nofile = atoi(p->value); } else if (strcasecmp(p->key, "rlimit-stack") == 0) { c->rlimit_stack_set = 1; c->rlimit_stack = atoi(p->value); } else if (strcasecmp(p->key, "rlimit-nproc") == 0) { #ifdef RLIMIT_NPROC c->rlimit_nproc_set = 1; c->rlimit_nproc = atoi(p->value); #else avahi_log_error("Ignoring configuration key \"%s\" in group \"%s\"\n", p->key, g->name); #endif } else { avahi_log_error("Invalid configuration key \"%s\" in group \"%s\"\n", p->key, g->name); goto finish; } } } else { avahi_log_error("Invalid configuration file group \"%s\".\n", g->name); goto finish; } } r = 0; finish: if (f) avahi_ini_file_free(f); return r; } static void log_function(AvahiLogLevel level, const char *txt) { static const int log_level_map[] = { LOG_ERR, LOG_WARNING, LOG_NOTICE, LOG_INFO, LOG_DEBUG }; assert(level < AVAHI_LOG_LEVEL_MAX); assert(txt); if (!config.debug && level == AVAHI_LOG_DEBUG) return; daemon_log(log_level_map[level], "%s", txt); } static void dump(const char *text, AVAHI_GCC_UNUSED void* userdata) { avahi_log_info("%s", text); } #ifdef HAVE_INOTIFY static int inotify_fd = -1; static void add_inotify_watches(void) { int c = 0; /* We ignore the return values, because one or more of these files * might not exist and we're OK with that. In addition we never * want to remove these watches, hence we keep their ids? */ #ifdef ENABLE_CHROOT c = config.use_chroot; #endif inotify_add_watch(inotify_fd, c ? "/services" : AVAHI_SERVICE_DIR, IN_CLOSE_WRITE|IN_DELETE|IN_DELETE_SELF|IN_MOVED_FROM|IN_MOVED_TO|IN_MOVE_SELF|IN_ONLYDIR); inotify_add_watch(inotify_fd, c ? "/" : AVAHI_CONFIG_DIR, IN_CLOSE_WRITE|IN_DELETE|IN_DELETE_SELF|IN_MOVED_FROM|IN_MOVED_TO|IN_MOVE_SELF|IN_ONLYDIR); } #endif static void reload_config(void) { #ifdef HAVE_INOTIFY /* Refresh in case the config dirs have been removed */ add_inotify_watches(); #endif #ifdef ENABLE_CHROOT static_service_load(config.use_chroot); static_hosts_load(config.use_chroot); #else static_service_load(0); static_hosts_load(0); #endif static_service_add_to_server(); static_hosts_add_to_server(); if (resolv_conf_entry_group) avahi_s_entry_group_reset(resolv_conf_entry_group); load_resolv_conf(); update_wide_area_servers(); if (config.publish_resolv_conf && resolv_conf && resolv_conf[0]) resolv_conf_entry_group = add_dns_servers(avahi_server, resolv_conf_entry_group, resolv_conf); } #ifdef HAVE_INOTIFY static void inotify_callback(AvahiWatch *watch, int fd, AVAHI_GCC_UNUSED AvahiWatchEvent event, AVAHI_GCC_UNUSED void *userdata) { char* buffer; int n = 0; assert(fd == inotify_fd); assert(watch); ioctl(inotify_fd, FIONREAD, &n); if (n <= 0) n = 128; buffer = avahi_malloc(n); if (read(inotify_fd, buffer, n) < 0 ) { avahi_free(buffer); avahi_log_error("Failed to read inotify event: %s", avahi_strerror(errno)); return; } avahi_free(buffer); avahi_log_info("Files changed, reloading."); reload_config(); } #endif static void signal_callback(AvahiWatch *watch, AVAHI_GCC_UNUSED int fd, AVAHI_GCC_UNUSED AvahiWatchEvent event, AVAHI_GCC_UNUSED void *userdata) { int sig; const AvahiPoll *poll_api; assert(watch); assert(simple_poll_api); poll_api = avahi_simple_poll_get(simple_poll_api); if ((sig = daemon_signal_next()) <= 0) { avahi_log_error("daemon_signal_next() failed"); poll_api->watch_free(watch); return; } switch (sig) { case SIGINT: case SIGQUIT: case SIGTERM: avahi_log_info( "Got %s, quitting.", sig == SIGINT ? "SIGINT" : (sig == SIGQUIT ? "SIGQUIT" : "SIGTERM")); avahi_simple_poll_quit(simple_poll_api); break; case SIGHUP: avahi_log_info("Got SIGHUP, reloading."); reload_config(); break; case SIGUSR1: avahi_log_info("Got SIGUSR1, dumping record data."); avahi_server_dump(avahi_server, dump, NULL); break; default: avahi_log_warn("Got spurious signal, ignoring."); break; } } /* Imported from ../avahi-client/nss-check.c */ int avahi_nss_support(void); static int run_server(DaemonConfig *c) { int r = -1; int error; const AvahiPoll *poll_api = NULL; AvahiWatch *sig_watch = NULL; int retval_is_sent = 0; #ifdef HAVE_INOTIFY AvahiWatch *inotify_watch = NULL; #endif assert(c); if (!(nss_support = avahi_nss_support())) avahi_log_warn("WARNING: No NSS support for mDNS detected, consider installing nss-mdns!"); if (!(simple_poll_api = avahi_simple_poll_new())) { avahi_log_error("Failed to create main loop object."); goto finish; } poll_api = avahi_simple_poll_get(simple_poll_api); if (daemon_signal_init(SIGINT, SIGQUIT, SIGHUP, SIGTERM, SIGUSR1, 0) < 0) { avahi_log_error("Could not register signal handlers (%s).", strerror(errno)); goto finish; } if (!(sig_watch = poll_api->watch_new(poll_api, daemon_signal_fd(), AVAHI_WATCH_IN, signal_callback, simple_poll_api))) { avahi_log_error( "Failed to create signal watcher"); goto finish; } if (simple_protocol_setup(poll_api) < 0) goto finish; #ifdef HAVE_DBUS if (c->enable_dbus) { if (dbus_protocol_setup(poll_api, config.disable_user_service_publishing, !c->fail_on_missing_dbus #ifdef ENABLE_CHROOT && !config.use_chroot #endif ) < 0) { avahi_log_warn("WARNING: Failed to contact D-Bus daemon."); if (c->fail_on_missing_dbus) goto finish; } } #endif #ifdef ENABLE_CHROOT if (config.drop_root && config.use_chroot) { if (chroot(AVAHI_CONFIG_DIR) < 0) { avahi_log_error("Failed to chroot(): %s", strerror(errno)); goto finish; } avahi_log_info("Successfully called chroot()."); chdir("/"); if (avahi_caps_drop_all() < 0) { avahi_log_error("Failed to drop capabilities."); goto finish; } avahi_log_info("Successfully dropped remaining capabilities."); } #endif #ifdef HAVE_INOTIFY if ((inotify_fd = inotify_init()) < 0) avahi_log_warn( "Failed to initialize inotify: %s", strerror(errno)); else { add_inotify_watches(); if (!(inotify_watch = poll_api->watch_new(poll_api, inotify_fd, AVAHI_WATCH_IN, inotify_callback, NULL))) { avahi_log_error( "Failed to create inotify watcher"); goto finish; } } #endif load_resolv_conf(); #ifdef ENABLE_CHROOT static_service_load(config.use_chroot); static_hosts_load(config.use_chroot); #else static_service_load(0); static_hosts_load(0); #endif if (!(avahi_server = avahi_server_new(poll_api, &c->server_config, server_callback, c, &error))) { avahi_log_error("Failed to create server: %s", avahi_strerror(error)); goto finish; } update_wide_area_servers(); if (c->daemonize) { daemon_retval_send(0); retval_is_sent = 1; } for (;;) { if ((r = avahi_simple_poll_iterate(simple_poll_api, -1)) < 0) { /* We handle signals through an FD, so let's continue */ if (errno == EINTR) continue; avahi_log_error("poll(): %s", strerror(errno)); goto finish; } else if (r > 0) /* Quit */ break; } finish: static_service_remove_from_server(); static_service_free_all(); static_hosts_remove_from_server(); static_hosts_free_all(); remove_dns_server_entry_groups(); simple_protocol_shutdown(); #ifdef HAVE_DBUS if (c->enable_dbus) dbus_protocol_shutdown(); #endif if (avahi_server) { avahi_server_free(avahi_server); avahi_server = NULL; } daemon_signal_done(); if (sig_watch) poll_api->watch_free(sig_watch); #ifdef HAVE_INOTIFY if (inotify_watch) poll_api->watch_free(inotify_watch); if (inotify_fd >= 0) close(inotify_fd); #endif if (simple_poll_api) { avahi_simple_poll_free(simple_poll_api); simple_poll_api = NULL; } if (!retval_is_sent && c->daemonize) daemon_retval_send(1); return r; } #define set_env(key, value) putenv(avahi_strdup_printf("%s=%s", (key), (value))) static int drop_root(void) { struct passwd *pw; struct group * gr; int r; if (!(pw = getpwnam(AVAHI_USER))) { avahi_log_error( "Failed to find user '"AVAHI_USER"'."); return -1; } if (!(gr = getgrnam(AVAHI_GROUP))) { avahi_log_error( "Failed to find group '"AVAHI_GROUP"'."); return -1; } avahi_log_info("Found user '"AVAHI_USER"' (UID %lu) and group '"AVAHI_GROUP"' (GID %lu).", (unsigned long) pw->pw_uid, (unsigned long) gr->gr_gid); if (initgroups(AVAHI_USER, gr->gr_gid) != 0) { avahi_log_error("Failed to change group list: %s", strerror(errno)); return -1; } #if defined(HAVE_SETRESGID) r = setresgid(gr->gr_gid, gr->gr_gid, gr->gr_gid); #elif defined(HAVE_SETEGID) if ((r = setgid(gr->gr_gid)) >= 0) r = setegid(gr->gr_gid); #elif defined(HAVE_SETREGID) r = setregid(gr->gr_gid, gr->gr_gid); #else #error "No API to drop priviliges" #endif if (r < 0) { avahi_log_error("Failed to change GID: %s", strerror(errno)); return -1; } #if defined(HAVE_SETRESUID) r = setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid); #elif defined(HAVE_SETEUID) if ((r = setuid(pw->pw_uid)) >= 0) r = seteuid(pw->pw_uid); #elif defined(HAVE_SETREUID) r = setreuid(pw->pw_uid, pw->pw_uid); #else #error "No API to drop priviliges" #endif if (r < 0) { avahi_log_error("Failed to change UID: %s", strerror(errno)); return -1; } set_env("USER", pw->pw_name); set_env("LOGNAME", pw->pw_name); set_env("HOME", pw->pw_dir); avahi_log_info("Successfully dropped root privileges."); return 0; } static const char* pid_file_proc(void) { return AVAHI_DAEMON_RUNTIME_DIR"/pid"; } static int make_runtime_dir(void) { int r = -1; mode_t u; int reset_umask = 0; struct passwd *pw; struct group * gr; struct stat st; if (!(pw = getpwnam(AVAHI_USER))) { avahi_log_error( "Failed to find user '"AVAHI_USER"'."); goto fail; } if (!(gr = getgrnam(AVAHI_GROUP))) { avahi_log_error( "Failed to find group '"AVAHI_GROUP"'."); goto fail; } u = umask(0000); reset_umask = 1; if (mkdir(AVAHI_DAEMON_RUNTIME_DIR, 0755) < 0 && errno != EEXIST) { avahi_log_error("mkdir(\""AVAHI_DAEMON_RUNTIME_DIR"\"): %s", strerror(errno)); goto fail; } chown(AVAHI_DAEMON_RUNTIME_DIR, pw->pw_uid, gr->gr_gid); if (stat(AVAHI_DAEMON_RUNTIME_DIR, &st) < 0) { avahi_log_error("stat(): %s\n", strerror(errno)); goto fail; } if (!S_ISDIR(st.st_mode) || st.st_uid != pw->pw_uid || st.st_gid != gr->gr_gid) { avahi_log_error("Failed to create runtime directory "AVAHI_DAEMON_RUNTIME_DIR"."); goto fail; } r = 0; fail: if (reset_umask) umask(u); return r; } static void set_one_rlimit(int resource, rlim_t limit, const char *name) { struct rlimit rl; rl.rlim_cur = rl.rlim_max = limit; if (setrlimit(resource, &rl) < 0) avahi_log_warn("setrlimit(%s, {%u, %u}) failed: %s", name, (unsigned) limit, (unsigned) limit, strerror(errno)); } static void enforce_rlimits(void) { #ifdef RLIMIT_AS if (config.rlimit_as_set) set_one_rlimit(RLIMIT_AS, config.rlimit_as, "RLIMIT_AS"); #endif if (config.rlimit_core_set) set_one_rlimit(RLIMIT_CORE, config.rlimit_core, "RLIMIT_CORE"); if (config.rlimit_data_set) set_one_rlimit(RLIMIT_DATA, config.rlimit_data, "RLIMIT_DATA"); if (config.rlimit_fsize_set) set_one_rlimit(RLIMIT_FSIZE, config.rlimit_fsize, "RLIMIT_FSIZE"); if (config.rlimit_nofile_set) set_one_rlimit(RLIMIT_NOFILE, config.rlimit_nofile, "RLIMIT_NOFILE"); if (config.rlimit_stack_set) set_one_rlimit(RLIMIT_STACK, config.rlimit_stack, "RLIMIT_STACK"); #ifdef RLIMIT_NPROC if (config.rlimit_nproc_set) set_one_rlimit(RLIMIT_NPROC, config.rlimit_nproc, "RLIMIT_NPROC"); #endif /* the sysctl() call from iface-pfroute.c needs locked memory on FreeBSD */ #if defined(RLIMIT_MEMLOCK) && !defined(__FreeBSD__) /* We don't need locked memory */ set_one_rlimit(RLIMIT_MEMLOCK, 0, "RLIMIT_MEMLOCK"); #endif } #define RANDOM_DEVICE "/dev/urandom" static void init_rand_seed(void) { int fd; unsigned seed = 0; /* Try to initialize seed from /dev/urandom, to make it a little * less predictable, and to make sure that multiple machines * booted at the same time choose different random seeds. */ if ((fd = open(RANDOM_DEVICE, O_RDONLY)) >= 0) { read(fd, &seed, sizeof(seed)); close(fd); } /* If the initialization failed by some reason, we add the time to the seed*/ seed ^= (unsigned) time(NULL); srand(seed); } int main(int argc, char *argv[]) { int r = 255; int wrote_pid_file = 0; avahi_set_log_function(log_function); init_rand_seed(); avahi_server_config_init(&config.server_config); config.command = DAEMON_RUN; config.daemonize = 0; config.config_file = NULL; #ifdef HAVE_DBUS config.enable_dbus = 1; config.fail_on_missing_dbus = 1; #endif config.drop_root = 1; config.set_rlimits = 1; #ifdef ENABLE_CHROOT config.use_chroot = 1; #endif config.modify_proc_title = 1; config.disable_user_service_publishing = 0; config.publish_dns_servers = NULL; config.publish_resolv_conf = 0; config.use_syslog = 0; config.debug = 0; config.rlimit_as_set = 0; config.rlimit_core_set = 0; config.rlimit_data_set = 0; config.rlimit_fsize_set = 0; config.rlimit_nofile_set = 0; config.rlimit_stack_set = 0; #ifdef RLIMIT_NPROC config.rlimit_nproc_set = 0; #endif if ((argv0 = strrchr(argv[0], '/'))) argv0 = avahi_strdup(argv0 + 1); else argv0 = avahi_strdup(argv[0]); daemon_pid_file_ident = (const char *) argv0; daemon_log_ident = (char*) argv0; daemon_pid_file_proc = pid_file_proc; if (parse_command_line(&config, argc, argv) < 0) goto finish; if (config.modify_proc_title) avahi_init_proc_title(argc, argv); #ifdef ENABLE_CHROOT config.use_chroot = config.use_chroot && config.drop_root; #endif if (config.command == DAEMON_HELP) { help(stdout); r = 0; } else if (config.command == DAEMON_VERSION) { printf("%s "PACKAGE_VERSION"\n", argv0); r = 0; } else if (config.command == DAEMON_KILL) { if (daemon_pid_file_kill_wait(SIGTERM, 5) < 0) { avahi_log_warn("Failed to kill daemon: %s", strerror(errno)); goto finish; } r = 0; } else if (config.command == DAEMON_RELOAD) { if (daemon_pid_file_kill(SIGHUP) < 0) { avahi_log_warn("Failed to kill daemon: %s", strerror(errno)); goto finish; } r = 0; } else if (config.command == DAEMON_CHECK) r = (daemon_pid_file_is_running() >= 0) ? 0 : 1; else if (config.command == DAEMON_RUN) { pid_t pid; if (getuid() != 0 && config.drop_root) { avahi_log_error("This program is intended to be run as root."); goto finish; } if ((pid = daemon_pid_file_is_running()) >= 0) { avahi_log_error("Daemon already running on PID %u", pid); goto finish; } if (load_config_file(&config) < 0) goto finish; if (config.daemonize) { daemon_retval_init(); if ((pid = daemon_fork()) < 0) goto finish; else if (pid != 0) { int ret; /** Parent **/ if ((ret = daemon_retval_wait(20)) < 0) { avahi_log_error("Could not receive return value from daemon process."); goto finish; } r = ret; goto finish; } /* Child */ } if (config.use_syslog || config.daemonize) daemon_log_use = DAEMON_LOG_SYSLOG; if (make_runtime_dir() < 0) goto finish; if (config.drop_root) { #ifdef ENABLE_CHROOT if (config.use_chroot) if (avahi_caps_reduce() < 0) goto finish; #endif if (drop_root() < 0) goto finish; #ifdef ENABLE_CHROOT if (config.use_chroot) if (avahi_caps_reduce2() < 0) goto finish; #endif } if (daemon_pid_file_create() < 0) { avahi_log_error("Failed to create PID file: %s", strerror(errno)); if (config.daemonize) daemon_retval_send(1); goto finish; } else wrote_pid_file = 1; if (config.set_rlimits) enforce_rlimits(); chdir("/"); #ifdef ENABLE_CHROOT if (config.drop_root && config.use_chroot) if (avahi_chroot_helper_start(argv0) < 0) { avahi_log_error("failed to start chroot() helper daemon."); goto finish; } #endif avahi_log_info("%s "PACKAGE_VERSION" starting up.", argv0); avahi_set_proc_title(argv0, "%s: starting up", argv0); if (run_server(&config) == 0) r = 0; } finish: if (config.daemonize) daemon_retval_done(); avahi_server_config_free(&config.server_config); avahi_free(config.config_file); avahi_strfreev(config.publish_dns_servers); avahi_strfreev(resolv_conf); if (wrote_pid_file) { #ifdef ENABLE_CHROOT avahi_chroot_helper_unlink(pid_file_proc()); #else daemon_pid_file_remove(); #endif } #ifdef ENABLE_CHROOT avahi_chroot_helper_shutdown(); #endif avahi_free(argv0); return r; }