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-rw-r--r--avahi-dnsconfd/main.c608
1 files changed, 608 insertions, 0 deletions
diff --git a/avahi-dnsconfd/main.c b/avahi-dnsconfd/main.c
new file mode 100644
index 0000000..918beeb
--- /dev/null
+++ b/avahi-dnsconfd/main.c
@@ -0,0 +1,608 @@
+/* $Id$ */
+
+/***
+ 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 <config.h>
+#endif
+
+#include <sys/un.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <net/if.h>
+#include <signal.h>
+#include <sys/wait.h>
+#include <getopt.h>
+
+#include <glib.h>
+
+#include <avahi-common/util.h>
+#include <avahi-core/llist.h>
+
+#include <libdaemon/dfork.h>
+#include <libdaemon/dsignal.h>
+#include <libdaemon/dlog.h>
+#include <libdaemon/dpid.h>
+#include <libdaemon/dexec.h>
+
+#define BROWSE_DNS_SERVERS "BROWSE-DNS-SERVERS\n"
+
+static enum {
+ ACKWAIT,
+ BROWSING
+} state = ACKWAIT;
+
+static gboolean quit = FALSE;
+
+static enum {
+ DAEMON_RUN,
+ DAEMON_KILL,
+ DAEMON_RELOAD,
+ DAEMON_VERSION,
+ DAEMON_HELP
+} command = DAEMON_RUN;
+
+static gboolean daemonize = FALSE;
+
+typedef struct DNSServerInfo DNSServerInfo;
+
+struct DNSServerInfo {
+ gint interface;
+ guchar protocol;
+ gchar *address;
+ AVAHI_LLIST_FIELDS(DNSServerInfo, servers);
+};
+
+static AVAHI_LLIST_HEAD(DNSServerInfo, servers);
+
+static void server_info_free(DNSServerInfo *i) {
+ g_assert(i);
+
+ g_free(i->address);
+
+ AVAHI_LLIST_REMOVE(DNSServerInfo, servers, servers, i);
+ g_free(i);
+}
+
+static DNSServerInfo* get_server_info(gint interface, guchar protocol, const gchar *address) {
+ DNSServerInfo *i;
+ g_assert(address);
+
+ for (i = servers; i; i = i->servers_next)
+ if (i->interface == interface &&
+ i->protocol == protocol &&
+ strcmp(i->address, address) == 0)
+ return i;
+
+ return NULL;
+}
+
+static DNSServerInfo* new_server_info(gint interface, guchar protocol, const gchar *address) {
+ DNSServerInfo *i;
+
+ g_assert(address);
+
+ i = g_new(DNSServerInfo, 1);
+ i->interface = interface;
+ i->protocol = protocol;
+ i->address = g_strdup(address);
+
+ AVAHI_LLIST_PREPEND(DNSServerInfo, servers, servers, i);
+
+ return i;
+}
+
+static int open_socket(void) {
+ int fd = -1;
+ struct sockaddr_un sa;
+
+ if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
+ daemon_log(LOG_ERR, "socket(): %s", strerror(errno));
+ goto fail;
+ }
+
+ if (avahi_set_cloexec(fd) < 0) {
+ daemon_log(LOG_ERR, "fcntl(): %s", strerror(errno));
+ goto fail;
+ }
+
+ memset(&sa, 0, sizeof(sa));
+ sa.sun_family = AF_UNIX;
+ strncpy(sa.sun_path, AVAHI_SOCKET, sizeof(sa.sun_path)-1);
+ sa.sun_path[sizeof(sa.sun_path)-1] = 0;
+
+ if (connect(fd, (struct sockaddr*) &sa, sizeof(sa)) < 0) {
+ daemon_log(LOG_ERR, "connect(): %s", strerror(errno));
+ goto fail;
+ }
+
+ return fd;
+
+fail:
+ if (fd >= 0)
+ close(fd);
+
+ return -1;
+}
+
+static ssize_t loop_write(int fd, const void*data, size_t size) {
+
+ ssize_t ret = 0;
+ g_assert(fd >= 0 && data && size);
+
+ while (size > 0) {
+ ssize_t r;
+
+ if ((r = write(fd, data, size)) < 0)
+ return r;
+
+ if (r == 0)
+ break;
+
+ ret += r;
+ data = (guint8*) data + r;
+ size -= r;
+ }
+
+ return ret;
+}
+
+static gchar *concat_dns_servers(gint interface) {
+ DNSServerInfo *i;
+ gchar *r = NULL;
+
+ for (i = servers; i; i = i->servers_next)
+ if (i->interface == interface || interface <= 0) {
+ gchar *t;
+
+ if (!r)
+ t = g_strdup(i->address);
+ else
+ t = g_strdup_printf("%s %s", r, i->address);
+
+ g_free(r);
+ r = t;
+ }
+
+ return r;
+}
+
+static gchar *getifname(gint interface, gchar *name, guint len) {
+ int fd = -1;
+ gchar *ret = NULL;
+ struct ifreq ifr;
+
+ g_assert(interface >= 0);
+
+ if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
+ daemon_log(LOG_ERR, "socket(): %s", strerror(errno));
+ goto finish;
+ }
+
+ memset(&ifr, 0, sizeof(ifr));
+ ifr.ifr_ifindex = interface;
+
+ if (ioctl(fd, SIOCGIFNAME, &ifr) < 0) {
+ daemon_log(LOG_ERR, "SIOCGIFNAME: %s\n", strerror(errno));
+ goto finish;
+ }
+
+ strncpy(name, ifr.ifr_name, len-1);
+ name[len-1] = 0;
+ ret = name;
+
+finish:
+ if (fd >= 0)
+ close(fd);
+
+ return ret;
+ }
+
+static void run_script(gboolean new, gint interface, guchar protocol, const gchar *address) {
+ gchar *p;
+ g_assert(interface > 0);
+ gint ret;
+ gchar ia[16], pa[16];
+ gchar name[IFNAMSIZ+1];
+
+ if (!getifname(interface, name, sizeof(name)))
+ return;
+
+ p = concat_dns_servers(interface);
+ g_setenv("AVAHI_INTERFACE_DNS_SERVERS", p ? p : "", TRUE);
+ g_free(p);
+
+ p = concat_dns_servers(-1);
+ g_setenv("AVAHI_DNS_SERVERS", p ? p : "", TRUE);
+ g_free(p);
+
+ g_setenv("AVAHI_INTERFACE", name, TRUE);
+
+ snprintf(ia, sizeof(ia), "%i", interface);
+ snprintf(pa, sizeof(pa), "%u", protocol);
+
+ if (daemon_exec("/", &ret, AVAHI_DNSCONF_SCRIPT, AVAHI_DNSCONF_SCRIPT, new ? "+" : "-", address, ia, pa, NULL) < 0)
+ daemon_log(LOG_WARNING, "Failed to run script");
+ else if (ret != 0)
+ daemon_log(LOG_WARNING, "Script returned with non-zero exit code %i", ret);
+}
+
+static gint new_line(const gchar *l) {
+ g_assert(l);
+
+ if (state == ACKWAIT) {
+ if (*l != '+') {
+ daemon_log(LOG_ERR, "Avahi command failed: %s", l);
+ return -1;
+ }
+
+ daemon_log(LOG_INFO, "Successfully connected to Avahi daemon.");
+ state = BROWSING;
+ } else {
+ gint interface;
+ guint protocol;
+ guint port;
+ gchar a[64];
+
+ g_assert(state == BROWSING);
+
+ if (*l != '<' && *l != '>') {
+ daemon_log(LOG_ERR, "Avahi sent us an invalid browsing line: %s", l);
+ return -1;
+ }
+
+ if (sscanf(l+1, "%i %u %64s %u", &interface, &protocol, a, &port) != 4) {
+ daemon_log(LOG_ERR, "Failed to parse browsing line: %s", l);
+ return -1;
+ }
+
+ if (*l == '>') {
+ if (port != 53)
+ daemon_log(LOG_WARNING, "DNS server with port address != 53 found, ignoring");
+ else {
+ daemon_log(LOG_INFO, "New DNS Server %s (interface: %i.%u)", a, interface, protocol);
+ new_server_info(interface, (guchar) protocol, a);
+ run_script(TRUE, interface, (guchar) protocol, a);
+ }
+ } else {
+ DNSServerInfo *i;
+
+ if (port == 53)
+ if ((i = get_server_info(interface, (guchar) protocol, a))) {
+ daemon_log(LOG_INFO, "DNS Server %s removed (interface: %i.%u)", a, interface, protocol);
+ server_info_free(i);
+ run_script(FALSE, interface, (guchar) protocol, a);
+ }
+ }
+
+ }
+
+ return 0;
+}
+
+static gint do_connect(void) {
+ gint fd = -1;
+
+ if ((fd = open_socket()) < 0)
+ goto fail;
+
+ if (loop_write(fd, BROWSE_DNS_SERVERS, sizeof(BROWSE_DNS_SERVERS)-1) < 0) {
+ daemon_log(LOG_ERR, "write(): %s", strerror(errno));
+ goto fail;
+ }
+
+ state = ACKWAIT;
+ return fd;
+
+fail:
+ if (fd >= 0)
+ close(fd);
+
+ return -1;
+}
+
+static void free_dns_server_info_list(void) {
+ while (servers) {
+ gint interface = servers->interface;
+ guchar protocol = servers->protocol;
+ gchar *address = g_strdup(servers->address);
+ server_info_free(servers);
+
+ run_script(FALSE, interface, protocol, address);
+ g_free(address);
+ }
+}
+
+static void help(FILE *f, const gchar *argv0) {
+ fprintf(f,
+ "%s [options]\n"
+ " -h --help Show this help\n"
+ " -D --daemonize Daemonize after startup\n"
+ " -k --kill Kill a running daemon\n"
+ " -r --reload Request a running daemon to reload static services\n"
+ " -V --version Show version\n",
+ argv0);
+}
+
+static gint parse_command_line(int argc, char *argv[]) {
+ gint c;
+
+ static const struct option const long_options[] = {
+ { "help", no_argument, NULL, 'h' },
+ { "daemonize", no_argument, NULL, 'D' },
+ { "kill", no_argument, NULL, 'k' },
+ { "version", no_argument, NULL, 'V' },
+ { "reload", no_argument, NULL, 'r' },
+ };
+
+ opterr = 0;
+ while ((c = getopt_long(argc, argv, "hDkVr", long_options, NULL)) >= 0) {
+
+ switch(c) {
+ case 'h':
+ command = DAEMON_HELP;
+ break;
+ case 'D':
+ daemonize = TRUE;
+ break;
+ case 'k':
+ command = DAEMON_KILL;
+ break;
+ case 'V':
+ command = DAEMON_VERSION;
+ break;
+ case 'r':
+ command = DAEMON_RELOAD;
+ break;
+ default:
+ fprintf(stderr, "Invalid command line argument: %c\n", c);
+ return -1;
+ }
+ }
+
+ if (optind < argc) {
+ fprintf(stderr, "Too many arguments\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+static int run_daemon(void) {
+ gint fd = -1, ret = -1;
+ gchar buf[1024];
+ size_t buflen = 0;
+
+ AVAHI_LLIST_HEAD_INIT(DNSServerInfo, servers);
+
+ daemon_signal_init(SIGINT, SIGTERM, SIGCHLD, SIGHUP, 0);
+
+ if ((fd = do_connect()) < 0)
+ goto finish;
+
+ if (daemonize)
+ daemon_retval_send(0);
+
+ while (!quit) {
+ fd_set rfds, wfds;
+
+ FD_ZERO(&rfds);
+ FD_ZERO(&wfds);
+
+ FD_SET(fd, &rfds);
+ FD_SET(daemon_signal_fd(), &rfds);
+
+ for (;;) {
+ if (select(fd+1, &rfds, NULL, NULL, NULL) < 0) {
+ if (errno == EINTR)
+ continue;
+
+ daemon_log(LOG_ERR, "select(): %s", strerror(errno));
+ goto finish;
+ }
+
+ break;
+ }
+
+ if (FD_ISSET(daemon_signal_fd(), &rfds)) {
+
+ int sig;
+
+ if ((sig = daemon_signal_next()) <= 0) {
+ daemon_log(LOG_ERR, "daemon_signal_next() failed");
+ goto finish;
+ }
+
+ switch(sig) {
+ case SIGINT:
+ case SIGTERM:
+ daemon_log(LOG_INFO, "Got %s, quitting.", sig == SIGINT ? "SIGINT" : "SIGTERM");
+ ret = 0;
+ goto finish;
+
+ case SIGCHLD:
+ waitpid(-1, NULL, WNOHANG);
+ break;
+
+ case SIGHUP:
+ daemon_log(LOG_INFO, "Rrefreshing DNS Server list");
+
+ close(fd);
+ free_dns_server_info_list();
+
+ if ((fd = do_connect()) < 0)
+ goto finish;
+
+ break;
+ }
+
+ } else if (FD_ISSET(fd, &rfds)) {
+ ssize_t r;
+ gchar *n;
+
+ if ((r = read(fd, buf, sizeof(buf) - buflen - 1)) <= 0) {
+ daemon_log(LOG_ERR, "read(): %s", r < 0 ? strerror(errno) : "EOF");
+ goto finish;
+ }
+
+ buflen += r;
+ g_assert(buflen <= sizeof(buf)-1);
+
+ while ((n = memchr(buf, '\n', buflen))) {
+ *(n++) = 0;
+
+ if (new_line(buf) < 0)
+ goto finish;
+
+ buflen -= (n - buf);
+ memmove(buf, n, buflen);
+ }
+
+ if (buflen >= sizeof(buf)-1) {
+ /* The incoming line is horribly long */
+ buf[sizeof(buf)-1] = 0;
+
+ if (new_line(buf) < 0)
+ goto finish;
+
+ buflen = 0;
+ }
+ }
+ }
+
+ ret = 0;
+
+finish:
+
+ free_dns_server_info_list();
+
+ if (fd >= 0)
+ close(fd);
+
+ daemon_signal_done();
+
+ return ret;
+}
+
+static const char* pid_file_proc(void) {
+ return AVAHI_RUNTIME_DIR"/avahi-dnsconfd.pid";
+}
+
+gint main(gint argc, gchar *argv[]) {
+ gchar *argv0;
+ gint r = 1;
+ gboolean wrote_pid_file = FALSE;
+
+ if ((argv0 = strrchr(argv[0], '/')))
+ argv0++;
+ else
+ argv0 = argv[0];
+
+ daemon_pid_file_ident = daemon_log_ident = argv0;
+ daemon_pid_file_proc = pid_file_proc;
+
+ if (parse_command_line(argc, argv) < 0)
+ goto finish;
+
+ if (command == DAEMON_RUN) {
+ pid_t pid;
+
+ if (getuid() != 0) {
+ daemon_log(LOG_ERR, "This program is intended to be run as root.");
+ goto finish;
+ }
+
+ if ((pid = daemon_pid_file_is_running()) >= 0) {
+ daemon_log(LOG_ERR, "Daemon already running on PID %u", pid);
+ goto finish;
+ }
+
+ if (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) {
+ daemon_log(LOG_ERR, "Could not recieve return value from daemon process.");
+ goto finish;
+ }
+
+ r = ret;
+ goto finish;
+ }
+
+ /* Child */
+ }
+
+ chdir("/");
+
+ if (daemon_pid_file_create() < 0) {
+ daemon_log(LOG_ERR, "Failed to create PID file: %s", strerror(errno));
+
+ if (daemonize)
+ daemon_retval_send(1);
+ goto finish;
+ } else
+ wrote_pid_file = TRUE;
+
+ if (run_daemon() < 0)
+ goto finish;
+
+ } else if (command == DAEMON_HELP) {
+ help(stdout, argv0);
+
+ } else if (command == DAEMON_VERSION) {
+ printf("%s "PACKAGE_VERSION"\n", argv0);
+
+ } else if (command == DAEMON_KILL) {
+ if (daemon_pid_file_kill_wait(SIGTERM, 5) < 0) {
+ daemon_log(LOG_WARNING, "Failed to kill daemon: %s", strerror(errno));
+ goto finish;
+ }
+
+ } else if (command == DAEMON_RELOAD) {
+ if (daemon_pid_file_kill(SIGHUP) < 0) {
+ daemon_log(LOG_WARNING, "Failed to kill daemon: %s", strerror(errno));
+ goto finish;
+ }
+ }
+
+ r = 0;
+
+finish:
+
+ if (daemonize)
+ daemon_retval_done();
+
+ if (wrote_pid_file)
+ daemon_pid_file_remove();
+
+ return r;
+}
generated by cgit (git 2.34.1) at 2024-05-09 00:05:24 +0000