From 9f9f4f6ea2405edc642d322c19f6f13e31920046 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Fri, 24 Jun 2005 01:00:13 +0000 Subject: * update todo list * add avvahi-dnsconfd * implement AvahiDNSServerBrowser * Update special browse/register RRs to match current RFC * add support to avahi-daemon to publish name server information * add support to avahi-daemon to publish /etc/resolv.conf DNS server information * add new simple protocol command: "BROWSE-DNS-SERVERS" * cleanup final configure message git-svn-id: file:///home/lennart/svn/public/avahi/trunk@143 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe --- avahi-dnsconfd/Makefile.am | 51 ++++ avahi-dnsconfd/dnsconf.action | 62 +++++ avahi-dnsconfd/main.c | 608 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 721 insertions(+) create mode 100644 avahi-dnsconfd/Makefile.am create mode 100755 avahi-dnsconfd/dnsconf.action create mode 100644 avahi-dnsconfd/main.c (limited to 'avahi-dnsconfd') diff --git a/avahi-dnsconfd/Makefile.am b/avahi-dnsconfd/Makefile.am new file mode 100644 index 0000000..8a0787a --- /dev/null +++ b/avahi-dnsconfd/Makefile.am @@ -0,0 +1,51 @@ +# $Id$ +# +# 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 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 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. + +pkgsysconfdir=$(sysconfdir)/avahi + +AM_CFLAGS= \ + -I$(top_srcdir) \ + -D_GNU_SOURCE \ + -DAVAHI_DNSCONF_SCRIPT=\"$(pkgsysconfdir)/dnsconf.action\" \ + -DAVAHI_SOCKET=\"$(localstatedir)/run/avahi/socket\" \ + -DAVAHI_RUNTIME_DIR=\"$(localstatedir)/run\" + +# GLIB 2.0 +AM_CFLAGS+=$(GLIB20_CFLAGS) +AM_LDADD=$(GLIB20_LIBS) + +# libdaemon +AM_CFLAGS+=$(LIBDAEMON_CFLAGS) +AM_LDADD+=$(LIBDAEMON_LIBS) + +# This cool debug trap works on i386/gcc only +AM_CFLAGS+='-DDEBUG_TRAP=__asm__("int $$3")' + +bin_PROGRAMS = \ + avahi-dnsconfd + +avahi_dnsconfd_SOURCES = \ + main.c main.h + +avahi_dnsconfd_CFLAGS = $(AM_CFLAGS) +avahi_dnsconfd_LDADD = $(AM_LDADD) ../avahi-common/libavahi-common.la + +pkgsysconf_DATA=dnsconf.action + +EXTRA_DIST=dnsconf.action diff --git a/avahi-dnsconfd/dnsconf.action b/avahi-dnsconfd/dnsconf.action new file mode 100755 index 0000000..9337a6d --- /dev/null +++ b/avahi-dnsconfd/dnsconf.action @@ -0,0 +1,62 @@ +#!/bin/sh + +# $Id$ +# +# 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 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 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. + +set -e + +test "x$AVAHI_INTERFACE" != "x" + +# Command line arguments: +# $1 "+" if a new DNS server was found, "-" if one was removed +# $2 DNS Server address +# $3 interface index where this server was found on +# $4 protocol number where this server was found on + +# Available environment variables: +# +# $AVAHI_INTERFACE The interface name where this DNS server was found on +# $AVAHI_INTERFACE_DNS_SERVERS A whitespace seperated list of DNS servers on $AVAHI_INTERFACE +# $AVAHI_DNS_SERVERS The complete list of all DNS servers found on all interfaces + +if [ -x /sbin/resolvconf ] ; then + + # We have Debian's resolvconf tool + + if [ "x$AVAHI_INTERFACE_DNS_SERVERS" = "x" ] ; then + /sbin/resolvconf -d "$AVAHI_INTERFACE.avahi" + else + for n in $AVAHI_INTERFACE_DNS_SERVERS ; do + echo "nameserver $n" + done | /sbin/resolvconf -a "$AVAHI_INTERFACE.avahi" + fi +else + + # No resolvconf tool available + + if [ "x$AVAHI_DNS_SERVERS" = "x" ] ; then + test -f /etc/resolv.conf.avahi && mv /etc/resolv.conf.avahi /etc/resolv.conf + else + test -f /etc/resolv.conf.avahi || mv /etc/resolv.conf /etc/resolv.conf.avahi + + for n in $AVAHI_DNS_SERVERS ; do + echo "nameserver $n" + done > /etc/resolv.conf + fi +fi 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 +#endif + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include +#include + +#include +#include +#include +#include +#include + +#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; +} -- cgit