X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=avahi-daemon%2Fmain.c;h=99bf86036d5fd45449d295f73a5ea96ce81c5914;hb=0632e854728e8e64552ae08f90852d4a2658539e;hp=ec7611471ded7ddf883cd48a8027ad0f3eca5034;hpb=ad7b145ebe82c3a53632eaa6ec75b014d91a7bea;p=catta

diff --git a/avahi-daemon/main.c b/avahi-daemon/main.c
index ec76114..99bf860 100644
--- a/avahi-daemon/main.c
+++ b/avahi-daemon/main.c
@@ -29,6 +29,10 @@
 #include <errno.h>
 #include <string.h>
 #include <unistd.h>
+#include <grp.h>
+#include <pwd.h>
+#include <sys/stat.h>
+#include <stdio.h>
 
 #include <libdaemon/dfork.h>
 #include <libdaemon/dsignal.h>
@@ -50,7 +54,8 @@ typedef enum {
     DAEMON_KILL,
     DAEMON_VERSION,
     DAEMON_HELP,
-    DAEMON_RELOAD
+    DAEMON_RELOAD,
+    DAEMON_CHECK
 } DaemonCommand;
 
 typedef struct {
@@ -59,19 +64,143 @@ typedef struct {
     gboolean daemonize;
     gchar *config_file;
     gboolean enable_dbus;
+    gboolean drop_root;
+    gboolean publish_resolv_conf;
+    gchar ** publish_dns_servers;
 } DaemonConfig;
 
+#define RESOLV_CONF "/etc/resolv.conf"
+
+static AvahiEntryGroup *dns_servers_entry_group = NULL;
+static AvahiEntryGroup *resolv_conf_entry_group = NULL;
+
+static gchar **resolv_conf = NULL;
+
+static DaemonConfig config;
+
+#define MAX_NAME_SERVERS 10
+
+static gint load_resolv_conf(const DaemonConfig *c) {
+    gint ret = -1;
+    FILE *f;
+    gint i = 0;
+    
+    g_strfreev(resolv_conf);
+    resolv_conf = NULL;
+
+    if (!c->publish_resolv_conf)
+        return 0;
+
+    if (!(f = fopen(RESOLV_CONF, "r"))) {
+        avahi_log_warn("Failed to open "RESOLV_CONF".");
+        goto finish;
+    }
+
+    resolv_conf = g_new0(gchar*, MAX_NAME_SERVERS+1);
+
+    while (!feof(f) && i < MAX_NAME_SERVERS) {
+        char ln[128];
+        gchar *p;
+
+        if (!(fgets(ln, sizeof(ln), f)))
+            break;
+
+        ln[strcspn(ln, "\r\n#")] = 0;
+        p = ln + strspn(ln, "\t ");
+
+        if (g_str_has_prefix(p, "nameserver")) {
+            p += 10;
+            p += strspn(p, "\t ");
+            p[strcspn(p, "\t ")] = 0;
+            resolv_conf[i++] = strdup(p);
+        }
+    }
+
+    ret = 0;
+
+finish:
+
+    if (ret != 0) {
+        g_strfreev(resolv_conf);
+        resolv_conf = NULL;
+    }
+        
+    if (f)
+        fclose(f);
+
+    return ret;
+}
+
+static AvahiEntryGroup* add_dns_servers(AvahiServer *s, AvahiEntryGroup* g, gchar **l) {
+    gchar **p;
+
+    g_assert(s);
+    g_assert(l);
+
+    if (!g) 
+        g = avahi_entry_group_new(s, NULL, NULL);
+
+    g_assert(avahi_entry_group_is_empty(g));
+
+    for (p = l; *p; p++) {
+        AvahiAddress a;
+        
+        if (!avahi_address_parse(*p, AF_UNSPEC, &a))
+            avahi_log_warn("Failed to parse address '%s', ignoring.", *p);
+        else
+            if (avahi_server_add_dns_server_address(s, g, -1, AF_UNSPEC, NULL, AVAHI_DNS_SERVER_RESOLVE, &a, 53) < 0) {
+                avahi_entry_group_free(g);
+                avahi_log_error("Failed to add DNS server address: %s", avahi_strerror(avahi_server_errno(s)));
+                return NULL;
+            }
+    }
+
+    avahi_entry_group_commit(g);
+
+    return g;
+}
+
+static void remove_dns_server_entry_groups(void) {
+
+    if (resolv_conf_entry_group)
+        avahi_entry_group_reset(resolv_conf_entry_group);
+    
+    if (dns_servers_entry_group) 
+        avahi_entry_group_reset(dns_servers_entry_group);
+}
+
 static void server_callback(AvahiServer *s, AvahiServerState state, gpointer userdata) {
+    DaemonConfig *c = userdata;
+    
     g_assert(s);
+    g_assert(c);
+
+#ifdef ENABLE_DBUS
+    if (c->enable_dbus)
+        dbus_protocol_server_state_changed(state);
+#endif
 
     if (state == AVAHI_SERVER_RUNNING) {
         avahi_log_info("Server startup complete.  Host name is <%s>", avahi_server_get_host_name_fqdn(s));
         static_service_add_to_server();
+
+        remove_dns_server_entry_groups();
+
+        if (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();
+        
     } else if (state == AVAHI_SERVER_COLLISION) {
         gchar *n;
 
         static_service_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);
@@ -86,14 +215,15 @@ static void help(FILE *f, const gchar *argv0) {
             "    -D --daemonize   Daemonize after startup\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",
             argv0);
 }
 
-static gint parse_command_line(DaemonConfig *config, int argc, char *argv[]) {
-    gint c;
+static gint parse_command_line(DaemonConfig *c, int argc, char *argv[]) {
+    gint o;
     
     static const struct option const long_options[] = {
         { "help",      no_argument,       NULL, 'h' },
@@ -102,35 +232,39 @@ static gint parse_command_line(DaemonConfig *config, int argc, char *argv[]) {
         { "version",   no_argument,       NULL, 'V' },
         { "file",      required_argument, NULL, 'f' },
         { "reload",    no_argument,       NULL, 'r' },
+        { "check",     no_argument,       NULL, 'c' },
     };
 
-    g_assert(config);
+    g_assert(c);
 
     opterr = 0;
-    while ((c = getopt_long(argc, argv, "hDkVf:r", long_options, NULL)) >= 0) {
+    while ((o = getopt_long(argc, argv, "hDkVf:rc", long_options, NULL)) >= 0) {
 
-        switch(c) {
+        switch(o) {
             case 'h':
-                config->command = DAEMON_HELP;
+                c->command = DAEMON_HELP;
                 break;
             case 'D':
-                config->daemonize = TRUE;
+                c->daemonize = TRUE;
                 break;
             case 'k':
-                config->command = DAEMON_KILL;
+                c->command = DAEMON_KILL;
                 break;
             case 'V':
-                config->command = DAEMON_VERSION;
+                c->command = DAEMON_VERSION;
                 break;
             case 'f':
-                g_free(config->config_file);
-                config->config_file = g_strdup(optarg);
+                g_free(c->config_file);
+                c->config_file = g_strdup(optarg);
                 break;
             case 'r':
-                config->command = DAEMON_RELOAD;
+                c->command = DAEMON_RELOAD;
+                break;
+            case 'c':
+                c->command = DAEMON_CHECK;
                 break;
             default:
-                fprintf(stderr, "Invalid command line argument: %c\n", c);
+                fprintf(stderr, "Invalid command line argument: %c\n", o);
                 return -1;
         }
     }
@@ -149,17 +283,18 @@ static gboolean is_yes(const gchar *s) {
     return *s == 'y' || *s == 'Y';
 }
 
-static gint load_config_file(DaemonConfig *config) {
+static gint load_config_file(DaemonConfig *c) {
     int r = -1;
     GKeyFile *f = NULL;
     GError *err = NULL;
     gchar **groups = NULL, **g, **keys = NULL, *v = NULL;
 
-    g_assert(config);
+    g_assert(c);
     
     f = g_key_file_new();
+    g_key_file_set_list_separator(f, ',');
     
-    if (!g_key_file_load_from_file(f, config->config_file ? config->config_file : AVAHI_CONFIG_FILE, G_KEY_FILE_NONE, &err)) {
+    if (!g_key_file_load_from_file(f, c->config_file ? c->config_file : AVAHI_CONFIG_FILE, G_KEY_FILE_NONE, &err)) {
         fprintf(stderr, "Unable to read config file: %s\n", err->message);
         goto finish;
     }
@@ -177,23 +312,25 @@ static gint load_config_file(DaemonConfig *config) {
                 v = g_key_file_get_value(f, *g, *k, NULL);
                 
                 if (g_strcasecmp(*k, "host-name") == 0) {
-                    g_free(config->server_config.host_name);
-                    config->server_config.host_name = v;
+                    g_free(c->server_config.host_name);
+                    c->server_config.host_name = v;
                     v = NULL;
                 } else if (g_strcasecmp(*k, "domain-name") == 0) {
-                    g_free(config->server_config.domain_name);
-                    config->server_config.domain_name = v;
+                    g_free(c->server_config.domain_name);
+                    c->server_config.domain_name = v;
                     v = NULL;
                 } else if (g_strcasecmp(*k, "use-ipv4") == 0)
-                    config->server_config.use_ipv4 = is_yes(v);
+                    c->server_config.use_ipv4 = is_yes(v);
                 else if (g_strcasecmp(*k, "use-ipv6") == 0)
-                    config->server_config.use_ipv6 = is_yes(v);
+                    c->server_config.use_ipv6 = is_yes(v);
                 else if (g_strcasecmp(*k, "check-response-ttl") == 0)
-                    config->server_config.check_response_ttl = is_yes(v);
+                    c->server_config.check_response_ttl = is_yes(v);
                 else if (g_strcasecmp(*k, "use-iff-running") == 0)
-                    config->server_config.use_iff_running = is_yes(v);
+                    c->server_config.use_iff_running = is_yes(v);
                 else if (g_strcasecmp(*k, "enable-dbus") == 0)
-                    config->enable_dbus = is_yes(v);
+                    c->enable_dbus = is_yes(v);
+                else if (g_strcasecmp(*k, "drop-root") == 0)
+                    c->drop_root = is_yes(v);
                 else {
                     fprintf(stderr, "Invalid configuration key \"%s\" in group \"%s\"\n", *k, *g);
                     goto finish;
@@ -216,14 +353,19 @@ static gint load_config_file(DaemonConfig *config) {
                 v = g_key_file_get_string(f, *g, *k, NULL);
                 
                 if (g_strcasecmp(*k, "publish-addresses") == 0)
-                    config->server_config.publish_addresses = is_yes(v);
+                    c->server_config.publish_addresses = is_yes(v);
                 else if (g_strcasecmp(*k, "publish-hinfo") == 0)
-                    config->server_config.publish_hinfo = is_yes(v);
+                    c->server_config.publish_hinfo = is_yes(v);
                 else if (g_strcasecmp(*k, "publish-workstation") == 0)
-                    config->server_config.publish_workstation = is_yes(v);
+                    c->server_config.publish_workstation = is_yes(v);
                 else if (g_strcasecmp(*k, "publish-domain") == 0)
-                    config->server_config.publish_domain = is_yes(v);
-                else {
+                    c->server_config.publish_domain = is_yes(v);
+                else if (g_strcasecmp(*k, "publish-resolv-conf-dns-servers") == 0)
+                    c->publish_resolv_conf = is_yes(v);
+                else if (g_strcasecmp(*k, "publish-dns-servers") == 0) {
+                    g_strfreev(c->publish_dns_servers);
+                    c->publish_dns_servers = g_key_file_get_string_list(f, *g, *k, NULL, NULL);
+                } else {
                     fprintf(stderr, "Invalid configuration key \"%s\" in group \"%s\"\n", *k, *g);
                     goto finish;
                 }
@@ -245,9 +387,9 @@ static gint load_config_file(DaemonConfig *config) {
                 v = g_key_file_get_string(f, *g, *k, NULL);
                 
                 if (g_strcasecmp(*k, "enable-reflector") == 0)
-                    config->server_config.enable_reflector = is_yes(v);
+                    c->server_config.enable_reflector = is_yes(v);
                 else if (g_strcasecmp(*k, "reflect-ipv") == 0)
-                    config->server_config.reflect_ipv = is_yes(v);
+                    c->server_config.reflect_ipv = is_yes(v);
                 else {
                     fprintf(stderr, "Invalid configuration key \"%s\" in group \"%s\"\n", *k, *g);
                     goto finish;
@@ -299,9 +441,16 @@ static void log_function(AvahiLogLevel level, const gchar *txt) {
     daemon_log(log_level_map[level], "%s", txt);
 }
 
+static void dump(const gchar *text, gpointer userdata) {
+    avahi_log_info("%s", text);
+}
+
 static gboolean signal_callback(GIOChannel *source, GIOCondition condition, gpointer data) {
     gint sig;
+    GMainLoop *loop = data;
+    
     g_assert(source);
+    g_assert(loop);
 
     if ((sig = daemon_signal_next()) <= 0) {
         avahi_log_error("daemon_signal_next() failed");
@@ -316,13 +465,27 @@ static gboolean signal_callback(GIOChannel *source, GIOCondition condition, gpoi
                 "Got %s, quitting.",
                 sig == SIGINT ? "SIGINT" :
                 (sig == SIGQUIT ? "SIGQUIT" : "SIGTERM"));
-            g_main_loop_quit((GMainLoop*) data);
+            g_main_loop_quit(loop);
             break;
 
         case SIGHUP:
             avahi_log_info("Got SIGHUP, reloading.");
             static_service_load();
             static_service_add_to_server();
+
+            if (resolv_conf_entry_group)
+                avahi_entry_group_reset(resolv_conf_entry_group);
+
+            load_resolv_conf(&config);
+            
+            if (resolv_conf && resolv_conf[0])
+                resolv_conf_entry_group = add_dns_servers(avahi_server, resolv_conf_entry_group, resolv_conf);
+
+            break;
+
+        case SIGUSR1:
+            avahi_log_info("Got SIGUSR1, dumping record data.");
+            avahi_server_dump(avahi_server, dump, NULL);
             break;
 
         default:
@@ -333,17 +496,18 @@ static gboolean signal_callback(GIOChannel *source, GIOCondition condition, gpoi
     return TRUE;
 }
 
-static gint run_server(DaemonConfig *config) {
+static gint run_server(DaemonConfig *c) {
     GMainLoop *loop = NULL;
     gint r = -1;
     GIOChannel *io = NULL;
     guint watch_id = (guint) -1;
+    gint error;
 
-    g_assert(config);
+    g_assert(c);
     
     loop = g_main_loop_new(NULL, FALSE);
 
-    if (daemon_signal_init(SIGINT, SIGQUIT, SIGHUP, SIGTERM, 0) < 0) {
+    if (daemon_signal_init(SIGINT, SIGQUIT, SIGHUP, SIGTERM, SIGUSR1, 0) < 0) {
         avahi_log_error("Could not register signal handlers (%s).", strerror(errno));
         goto finish;
     }
@@ -360,17 +524,21 @@ static gint run_server(DaemonConfig *config) {
         goto finish;
     
 #ifdef ENABLE_DBUS
-    if (config->enable_dbus)
+    if (c->enable_dbus)
         if (dbus_protocol_setup(loop) < 0)
             goto finish;
 #endif
     
-    if (!(avahi_server = avahi_server_new(NULL, &config->server_config, server_callback, NULL)))
+    if (!(avahi_server = avahi_server_new(NULL, &c->server_config, server_callback, c, &error))) {
+        avahi_log_error("Failed to create server: %s", avahi_strerror(error));
         goto finish;
+    }
+
+    load_resolv_conf(c);
     
     static_service_load();
 
-    if (config->daemonize) {
+    if (c->daemonize) {
         daemon_retval_send(0);
         r = 0;
     }
@@ -381,14 +549,16 @@ finish:
     
     static_service_remove_from_server();
     static_service_free_all();
+    remove_dns_server_entry_groups();
     
     simple_protocol_shutdown();
 
 #ifdef ENABLE_DBUS
-    if (config->enable_dbus)
+    if (c->enable_dbus)
         dbus_protocol_shutdown();
 #endif
 
+
     if (avahi_server)
         avahi_server_free(avahi_server);
 
@@ -404,15 +574,124 @@ finish:
     if (loop)
         g_main_loop_unref(loop);
 
-    if (r != 0 && config->daemonize)
+    if (r != 0 && c->daemonize)
         daemon_retval_send(1);
     
     return r;
 }
 
+static gint drop_root(void) {
+    struct passwd *pw;
+    struct group * gr;
+    gint 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_SETREGID)
+    r = setregid(gr->gr_gid, gr->gr_gid);
+#else
+    if ((r = setgid(gr->gr_gid)) >= 0)
+        r = setegid(gr->gr_gid);
+#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_SETREUID)
+    r = setreuid(pw->pw_uid, pw->pw_uid);
+#else
+    if ((r = setuid(pw->pw_uid)) >= 0)
+        r = seteuid(pw->pw_uid);
+#endif
+
+    if (r < 0) {
+        avahi_log_error("Failed to change UID: %s", strerror(errno));
+        return -1;
+    }
+
+    g_setenv("USER", pw->pw_name, 1);
+    g_setenv("LOGNAME", pw->pw_name, 1);
+    g_setenv("HOME", pw->pw_dir, 1);
+    
+    avahi_log_info("Successfully dropped root privileges.");
+
+    return 0;
+}
+
+static const char* pid_file_proc(void) {
+    return AVAHI_DAEMON_RUNTIME_DIR"/pid";
+}
+
+static gint make_runtime_dir(void) {
+    gint r = -1;
+    mode_t u;
+    gboolean reset_umask = FALSE;
+    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 = TRUE;
+    
+    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;
+
+}
+
 int main(int argc, char *argv[]) {
     gint r = 255;
-    DaemonConfig config;
     const gchar *argv0;
     gboolean wrote_pid_file = FALSE;
 
@@ -423,13 +702,18 @@ int main(int argc, char *argv[]) {
     config.daemonize = FALSE;
     config.config_file = NULL;
     config.enable_dbus = TRUE;
+    config.drop_root = TRUE;
+    config.publish_dns_servers = NULL;
+    config.publish_resolv_conf = FALSE;
 
     if ((argv0 = strrchr(argv[0], '/')))
         argv0++;
     else
         argv0 = argv[0];
 
-    daemon_pid_file_ident = daemon_log_ident = (char *) argv0;
+    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;
@@ -439,7 +723,7 @@ int main(int argc, char *argv[]) {
         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));
@@ -447,7 +731,7 @@ int main(int argc, char *argv[]) {
         }
 
         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));
@@ -456,7 +740,9 @@ int main(int argc, char *argv[]) {
 
         r = 0;
         
-    } else if (config.command == DAEMON_RUN) {
+    } 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) {
@@ -473,7 +759,6 @@ int main(int argc, char *argv[]) {
             goto finish;
         
         if (config.daemonize) {
-
             daemon_retval_init();
             
             if ((pid = daemon_fork()) < 0)
@@ -494,6 +779,19 @@ int main(int argc, char *argv[]) {
             /* Child */
         }
 
+
+        printf("%s "PACKAGE_VERSION" starting up.\n", argv0);
+        
+        chdir("/");
+
+        if (make_runtime_dir() < 0)
+            goto finish;
+
+        if (config.drop_root) {
+            if (drop_root() < 0)
+                goto finish;
+        }
+
         if (daemon_pid_file_create() < 0) {
             avahi_log_error("Failed to create PID file: %s", strerror(errno));
 
@@ -514,6 +812,8 @@ finish:
 
     avahi_server_config_free(&config.server_config);
     g_free(config.config_file);
+    g_strfreev(config.publish_dns_servers);
+    g_strfreev(resolv_conf);
 
     if (wrote_pid_file)
         daemon_pid_file_remove();