X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=avahi-autoipd%2Fmain.c;h=72ee904e740ca375fac212c6be663027c4a0af50;hb=f479f120fbb067bb1d8259047a9406bf564b31f0;hp=617a54727f6a422debe44801e50140fb3d81376d;hpb=25ae811f3393baed4930f30278a7595dd8122dfb;p=catta diff --git a/avahi-autoipd/main.c b/avahi-autoipd/main.c index 617a547..72ee904 100644 --- a/avahi-autoipd/main.c +++ b/avahi-autoipd/main.c @@ -43,6 +43,8 @@ #include #include #include +#include +#include #include #include @@ -79,6 +81,7 @@ #define IPV4LL_NETWORK 0xA9FE0000L #define IPV4LL_NETMASK 0xFFFF0000L #define IPV4LL_HOSTMASK 0x0000FFFFL +#define IPV4LL_BROADCAST 0xA9FEFFFFL #define ETHER_ADDRLEN 6 #define ARP_PACKET_SIZE (8+4+4+2*ETHER_ADDRLEN) @@ -108,6 +111,12 @@ static int wait_for_address = 0; static int use_syslog = 0; static int debug = 0; static int modify_proc_title = 1; +static int force_bind = 0; +#ifdef HAVE_CHROOT +static int no_chroot = 0; +#endif +static int no_drop_root = 0; +static int wrote_pid_file = 0; static enum { DAEMON_RUN, @@ -126,6 +135,19 @@ typedef enum CalloutEvent { CALLOUT_MAX } CalloutEvent; +static const char * const callout_event_table[CALLOUT_MAX] = { + [CALLOUT_BIND] = "BIND", + [CALLOUT_CONFLICT] = "CONFLICT", + [CALLOUT_UNBIND] = "UNBIND", + [CALLOUT_STOP] = "STOP" +}; + +typedef struct CalloutEventInfo { + CalloutEvent event; + uint32_t address; + int ifindex; +} CalloutEventInfo; + #define RANDOM_DEVICE "/dev/urandom" #define DEBUG(x) do {\ @@ -164,11 +186,69 @@ static uint32_t pick_addr(uint32_t old_addr) { addr = htonl(IPV4LL_NETWORK | (uint32_t) r); - } while (addr == old_addr); + } while (addr == old_addr || !is_ll_address(addr)); return addr; } +static int load_address(const char *fn, uint32_t *addr) { + FILE *f; + unsigned a, b, c, d; + + assert(fn); + assert(addr); + + if (!(f = fopen(fn, "r"))) { + + if (errno == ENOENT) { + *addr = 0; + return 0; + } + + daemon_log(LOG_ERR, "fopen() failed: %s", strerror(errno)); + goto fail; + } + + if (fscanf(f, "%u.%u.%u.%u\n", &a, &b, &c, &d) != 4) { + daemon_log(LOG_ERR, "Parse failure"); + goto fail; + } + + fclose(f); + + *addr = htonl((a << 24) | (b << 16) | (c << 8) | d); + return 0; + +fail: + if (f) + fclose(f); + + return -1; +} + +static int save_address(const char *fn, uint32_t addr) { + FILE *f; + char buf[32]; + + assert(fn); + + if (!(f = fopen(fn, "w"))) { + daemon_log(LOG_ERR, "fopen() failed: %s", strerror(errno)); + goto fail; + } + + fprintf(f, "%s\n", inet_ntop(AF_INET, &addr, buf, sizeof (buf))); + fclose(f); + + return 0; + +fail: + if (f) + fclose(f); + + return -1; +} + static void* packet_new(const ArpPacketInfo *info, size_t *packet_len) { uint8_t *r; @@ -242,7 +322,7 @@ static int packet_parse(const void *data, size_t packet_len, ArpPacketInfo *info } static void set_state(State st, int reset_counter, uint32_t address) { - const char* const state_table[] = { + static const char* const state_table[] = { [STATE_START] = "START", [STATE_WAITING_PROBE] = "WAITING_PROBE", [STATE_PROBING] = "PROBING", @@ -264,16 +344,14 @@ static void set_state(State st, int reset_counter, uint32_t address) { n_iteration = 0; } - if (modify_proc_title) { - if (state == STATE_SLEEPING) - avahi_set_proc_title("%s: sleeping", argv0); - else if (state == STATE_ANNOUNCING) - avahi_set_proc_title("%s: announcing %s", argv0, inet_ntop(AF_INET, &address, buf, sizeof(buf))); - else if (state == STATE_RUNNING) - avahi_set_proc_title("%s: bound %s", argv0, inet_ntop(AF_INET, &address, buf, sizeof(buf))); - else - avahi_set_proc_title("%s: probing %s", argv0, inet_ntop(AF_INET, &address, buf, sizeof(buf))); - } + if (state == STATE_SLEEPING) + avahi_set_proc_title(argv0, "%s: [%s] sleeping", argv0, interface_name); + else if (state == STATE_ANNOUNCING) + avahi_set_proc_title(argv0, "%s: [%s] announcing %s", argv0, interface_name, inet_ntop(AF_INET, &address, buf, sizeof(buf))); + else if (state == STATE_RUNNING) + avahi_set_proc_title(argv0, "%s: [%s] bound %s", argv0, interface_name, inet_ntop(AF_INET, &address, buf, sizeof(buf))); + else + avahi_set_proc_title(argv0, "%s: [%s] probing %s", argv0, interface_name, inet_ntop(AF_INET, &address, buf, sizeof(buf))); } static int interface_up(int iface) { @@ -314,23 +392,6 @@ fail: return -1; } -static int do_callout(CalloutEvent event, int iface, uint32_t addr) { - char buf[64], ifname[IFNAMSIZ]; - const char * const event_table[CALLOUT_MAX] = { - [CALLOUT_BIND] = "BIND", - [CALLOUT_CONFLICT] = "CONFLICT", - [CALLOUT_UNBIND] = "UNBIND", - [CALLOUT_STOP] = "STOP" - }; - - daemon_log(LOG_INFO, "Callout %s, address %s on interface %s", - event_table[event], - inet_ntop(AF_INET, &addr, buf, sizeof(buf)), - if_indextoname(iface, ifname)); - - return 0; -} - static int open_socket(int iface, uint8_t *hw_address) { int fd = -1; struct sockaddr_ll sa; @@ -440,7 +501,10 @@ fail: } int is_ll_address(uint32_t addr) { - return (ntohl(addr) & IPV4LL_NETMASK) == IPV4LL_NETWORK; + return + (ntohl(addr) & IPV4LL_NETMASK) == IPV4LL_NETWORK && + ntohl(addr) != IPV4LL_NETWORK && + ntohl(addr) != IPV4LL_BROADCAST; } static struct timeval *elapse_time(struct timeval *tv, unsigned msec, unsigned jitter) { @@ -457,6 +521,253 @@ static struct timeval *elapse_time(struct timeval *tv, unsigned msec, unsigned j return tv; } +static FILE* fork_dispatcher(void) { + FILE *ret; + int fds[2]; + pid_t pid; + + if (pipe(fds) < 0) { + daemon_log(LOG_ERR, "pipe() failed: %s", strerror(errno)); + goto fail; + } + + if ((pid = fork()) < 0) + goto fail; + else if (pid == 0) { + FILE *f = NULL; + int r = 1; + + /* Please note that the signal pipe is not closed at this + * point, signals will thus be dispatched in the main + * process. */ + + daemon_retval_done(); + + setsid(); + + avahi_set_proc_title(argv0, "%s: [%s] callout dispatcher", argv0, interface_name); + + close(fds[1]); + + if (!(f = fdopen(fds[0], "r"))) { + daemon_log(LOG_ERR, "fdopen() failed: %s", strerror(errno)); + goto dispatcher_fail; + } + + for (;;) { + CalloutEventInfo info; + char name[IFNAMSIZ], buf[64]; + int k; + + if (fread(&info, sizeof(info), 1, f) != 1) { + if (feof(f)) + break; + + daemon_log(LOG_ERR, "fread() failed: %s", strerror(errno)); + goto dispatcher_fail; + } + + assert(info.event <= CALLOUT_MAX); + + if (!if_indextoname(info.ifindex, name)) { + daemon_log(LOG_ERR, "if_indextoname() failed: %s", strerror(errno)); + continue; + } + + if (daemon_exec("/", &k, + AVAHI_IPCONF_SCRIPT, AVAHI_IPCONF_SCRIPT, + callout_event_table[info.event], + name, + inet_ntop(AF_INET, &info.address, buf, sizeof(buf)), NULL) < 0) { + + daemon_log(LOG_ERR, "Failed to run script: %s", strerror(errno)); + continue; + } + + if (k != 0) + daemon_log(LOG_WARNING, "Script execution failed with return value %i", k); + } + + r = 0; + + dispatcher_fail: + + if (f) + fclose(f); + +#ifdef HAVE_CHROOT + /* If the main process is trapped inside a chroot() we have to + * remove the PID file for it */ + + if (!no_chroot && wrote_pid_file) + daemon_pid_file_remove(); +#endif + + _exit(r); + } + + /* parent */ + + close(fds[0]); + fds[0] = -1; + + if (!(ret = fdopen(fds[1], "w"))) { + daemon_log(LOG_ERR, "fdopen() failed: %s", strerror(errno)); + goto fail; + } + + return ret; + +fail: + if (fds[0] >= 0) + close(fds[0]); + if (fds[1] >= 0) + close(fds[1]); + + return NULL; +} + +static int do_callout(FILE *f, CalloutEvent event, int iface, uint32_t addr) { + CalloutEventInfo info; + char buf[64], ifname[IFNAMSIZ]; + + daemon_log(LOG_INFO, "Callout %s, address %s on interface %s", + callout_event_table[event], + inet_ntop(AF_INET, &addr, buf, sizeof(buf)), + if_indextoname(iface, ifname)); + + info.event = event; + info.ifindex = iface; + info.address = addr; + + if (fwrite(&info, sizeof(info), 1, f) != 1 || fflush(f) != 0) { + daemon_log(LOG_ERR, "Failed to write callout event: %s", strerror(errno)); + return -1; + } + + return 0; +} + +#define set_env(key, value) putenv(avahi_strdup_printf("%s=%s", (key), (value))) + +static int drop_privs(void) { + struct passwd *pw; + struct group * gr; + int r; + mode_t u; + + /* Get user/group ID */ + + if (!no_drop_root) { + + if (!(pw = getpwnam(AVAHI_AUTOIPD_USER))) { + daemon_log(LOG_ERR, "Failed to find user '"AVAHI_AUTOIPD_USER"'."); + return -1; + } + + if (!(gr = getgrnam(AVAHI_AUTOIPD_GROUP))) { + daemon_log(LOG_ERR, "Failed to find group '"AVAHI_AUTOIPD_GROUP"'."); + return -1; + } + + daemon_log(LOG_INFO, "Found user '"AVAHI_AUTOIPD_USER"' (UID %lu) and group '"AVAHI_AUTOIPD_GROUP"' (GID %lu).", (unsigned long) pw->pw_uid, (unsigned long) gr->gr_gid); + } + + /* Create directory */ + u = umask(0000); + r = mkdir(AVAHI_IPDATA_DIR, 0755); + umask(u); + + if (r < 0 && errno != EEXIST) { + daemon_log(LOG_ERR, "mkdir(\""AVAHI_IPDATA_DIR"\"): %s", strerror(errno)); + return -1; + } + + /* Convey working directory */ + + if (!no_drop_root) { + struct stat st; + + chown(AVAHI_IPDATA_DIR, pw->pw_uid, gr->gr_gid); + + if (stat(AVAHI_IPDATA_DIR, &st) < 0) { + daemon_log(LOG_ERR, "stat(): %s\n", strerror(errno)); + return -1; + } + + if (!S_ISDIR(st.st_mode) || st.st_uid != pw->pw_uid || st.st_gid != gr->gr_gid) { + daemon_log(LOG_ERR, "Failed to create runtime directory "AVAHI_IPDATA_DIR"."); + return -1; + } + } + +#ifdef HAVE_CHROOT + + if (!no_chroot) { + if (chroot(AVAHI_IPDATA_DIR) < 0) { + daemon_log(LOG_ERR, "Failed to chroot(): %s", strerror(errno)); + return -1; + } + + daemon_log(LOG_INFO, "Successfully called chroot()."); + chdir("/"); + + /* Since we are now trapped inside a chroot we cannot remove + * the pid file anymore, the helper process will do that for us. */ + wrote_pid_file = 0; + } + +#endif + + if (!no_drop_root) { + + if (initgroups(AVAHI_AUTOIPD_USER, gr->gr_gid) != 0) { + daemon_log(LOG_ERR, "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) { + daemon_log(LOG_ERR, "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) { + daemon_log(LOG_ERR, "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); + + daemon_log(LOG_ERR, "Successfully dropped root privileges."); + } + + return 0; +} + static int loop(int iface, uint32_t addr) { enum { FD_ARP, @@ -479,18 +790,45 @@ static int loop(int iface, uint32_t addr) { Event event = EVENT_NULL; int retval_sent = !daemonize; State st; + FILE *dispatcher = NULL; + char *address_fn = NULL; + const char *p; daemon_signal_init(SIGINT, SIGTERM, SIGCHLD, SIGHUP,0); + if (!(dispatcher = fork_dispatcher())) + goto fail; + if ((fd = open_socket(iface, hw_address)) < 0) goto fail; if ((iface_fd = iface_init(iface)) < 0) goto fail; - if (iface_get_initial_state(&st) < 0) + if (drop_privs() < 0) goto fail; + if (force_bind) + st = STATE_START; + else if (iface_get_initial_state(&st) < 0) + goto fail; + +#ifdef HAVE_CHROOT + if (!no_chroot) + p = ""; + else +#endif + p = AVAHI_IPDATA_DIR; + + address_fn = avahi_strdup_printf( + "%s/%02x:%02x:%02x:%02x:%02x:%02x", p, + hw_address[0], hw_address[1], + hw_address[2], hw_address[3], + hw_address[4], hw_address[5]); + + if (!addr) + load_address(address_fn, &addr); + if (addr && !is_ll_address(addr)) { daemon_log(LOG_WARNING, "Requested address %s is not from IPv4LL range 169.254/16, ignoring.", inet_ntop(AF_INET, &addr, buf, sizeof(buf))); addr = 0; @@ -568,13 +906,10 @@ static int loop(int iface, uint32_t addr) { next_wakeup_valid = 1; if (n_iteration == 0) { - do_callout(CALLOUT_BIND, iface, addr); + if (do_callout(dispatcher, CALLOUT_BIND, iface, addr) < 0) + goto fail; + n_conflict = 0; - - if (!retval_sent) { - daemon_retval_send(0); - retval_sent = 1; - } } } else if ((state == STATE_ANNOUNCING && event == EVENT_TIMEOUT && n_iteration >= ANNOUNCE_NUM-1)) { @@ -583,7 +918,14 @@ static int loop(int iface, uint32_t addr) { set_state(STATE_RUNNING, 0, addr); next_wakeup_valid = 0; + + save_address(address_fn, addr); + if (!retval_sent) { + daemon_retval_send(0); + retval_sent = 1; + } + } else if (event == EVENT_PACKET) { ArpPacketInfo info; @@ -607,7 +949,8 @@ static int loop(int iface, uint32_t addr) { if (conflict) { if (state == STATE_RUNNING || state == STATE_ANNOUNCING) - do_callout(CALLOUT_CONFLICT, iface, addr); + if (do_callout(dispatcher, CALLOUT_CONFLICT, iface, addr) < 0) + goto fail; /* Pick a new address */ addr = pick_addr(addr); @@ -634,7 +977,8 @@ static int loop(int iface, uint32_t addr) { daemon_log(LOG_INFO, "A routable address has been configured."); if (state == STATE_RUNNING || state == STATE_ANNOUNCING) - do_callout(CALLOUT_UNBIND, iface, addr); + if (do_callout(dispatcher, CALLOUT_UNBIND, iface, addr) < 0) + goto fail; if (!retval_sent) { daemon_retval_send(0); @@ -644,7 +988,7 @@ static int loop(int iface, uint32_t addr) { set_state(STATE_SLEEPING, 1, addr); next_wakeup_valid = 0; - } else if (event == EVENT_ROUTABLE_ADDR_UNCONFIGURED && state == STATE_SLEEPING) { + } else if (event == EVENT_ROUTABLE_ADDR_UNCONFIGURED && state == STATE_SLEEPING && !force_bind) { daemon_log(LOG_INFO, "No longer a routable address configured, restarting probe process."); @@ -653,7 +997,7 @@ static int loop(int iface, uint32_t addr) { elapse_time(&next_wakeup, 0, PROBE_WAIT*1000); next_wakeup_valid = 1; - } else if (event == EVENT_REFRESH_REQUEST && state == STATE_RUNNING) { + } else if (event == EVENT_REFRESH_REQUEST && state == STATE_RUNNING && !force_bind) { /* The user requested a reannouncing of the address by a SIGHUP */ daemon_log(LOG_INFO, "Reannouncing address."); @@ -772,7 +1116,7 @@ static int loop(int iface, uint32_t addr) { fail: if (state == STATE_RUNNING || state == STATE_ANNOUNCING) - do_callout(CALLOUT_STOP, iface, addr); + do_callout(dispatcher, CALLOUT_STOP, iface, addr); avahi_free(out_packet); avahi_free(in_packet); @@ -785,6 +1129,12 @@ fail: if (daemonize && !retval_sent) daemon_retval_send(ret); + + if (dispatcher) + fclose(dispatcher); + + if (address_fn) + avahi_free(address_fn); return ret; } @@ -800,8 +1150,16 @@ static void help(FILE *f, const char *a0) { " -r --refresh Request a running daemon to refresh it's IP address\n" " -c --check Return 0 if a daemon is already running\n" " -V --version Show version\n" - " -S --start=ADDRESS Start with this address from the IPv4LL range 169.254.0.0/16\n" - " -w --wait Wait until an address has been acquired before daemonizing\n" + " -S --start=ADDRESS Start with this address from the IPv4LL range\n" + " 169.254.0.0/16\n" + " -w --wait Wait until an address has been acquired before\n" + " daemonizing\n" + " --force-bind Assign an IPv4LL address even if routable address\n" + " is already assigned\n" + " --no-drop-root Don't drop privileges\n" +#ifdef HAVE_CHROOT + " --no-chroot Don't chroot()\n" +#endif " --no-proc-title Don't modify process title\n" " --debug Increase verbosity\n", a0); @@ -812,7 +1170,12 @@ static int parse_command_line(int argc, char *argv[]) { enum { OPTION_NO_PROC_TITLE = 256, - OPTION_DEBUG + OPTION_FORCE_BIND, + OPTION_DEBUG, + OPTION_NO_DROP_ROOT, +#ifdef HAVE_CHROOT + OPTION_NO_CHROOT +#endif }; static const struct option long_options[] = { @@ -825,13 +1188,18 @@ static int parse_command_line(int argc, char *argv[]) { { "version", no_argument, NULL, 'V' }, { "start", required_argument, NULL, 'S' }, { "wait", no_argument, NULL, 'w' }, + { "force-bind", no_argument, NULL, OPTION_FORCE_BIND }, + { "no-drop-root", no_argument, NULL, OPTION_NO_DROP_ROOT }, +#ifdef HAVE_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 } }; opterr = 0; - while ((c = getopt_long(argc, argv, "hDkVrcS:", long_options, NULL)) >= 0) { + while ((c = getopt_long(argc, argv, "hDskrcVS:w", long_options, NULL)) >= 0) { switch(c) { case 's': @@ -874,6 +1242,20 @@ static int parse_command_line(int argc, char *argv[]) { debug = 1; break; + case OPTION_FORCE_BIND: + force_bind = 1; + break; + + case OPTION_NO_DROP_ROOT: + no_drop_root = 1; + break; + +#ifdef HAVE_CHROOT + case OPTION_NO_CHROOT: + no_chroot = 1; + break; +#endif + default: fprintf(stderr, "Invalid command line argument: %c\n", c); return -1; @@ -890,7 +1272,7 @@ static int parse_command_line(int argc, char *argv[]) { return -1; } - interface_name = argv[optind++]; + interface_name = avahi_strdup(argv[optind++]); } if (optind != argc) { @@ -907,21 +1289,25 @@ static const char* pid_file_proc(void) { int main(int argc, char*argv[]) { int r = 1; - int wrote_pid_file = 0; - - avahi_init_proc_title(argc, argv); + char *log_ident = NULL; + signal(SIGPIPE, SIG_IGN); + if ((argv0 = strrchr(argv[0], '/'))) - argv0++; + argv0 = avahi_strdup(argv0 + 1); else - argv0 = argv[0]; + argv0 = avahi_strdup(argv[0]); - daemon_pid_file_ident = daemon_log_ident = argv0; - daemon_pid_file_proc = pid_file_proc; + daemon_log_ident = argv0; if (parse_command_line(argc, argv) < 0) goto finish; + if (modify_proc_title) + avahi_init_proc_title(argc, argv); + + daemon_log_ident = log_ident = avahi_strdup_printf("%s(%s)", argv0, interface_name); + daemon_pid_file_proc = pid_file_proc; pid_file_name = avahi_strdup_printf(AVAHI_RUNTIME_DIR"/avahi-autoipd.%s.pid", interface_name); if (command == DAEMON_RUN) { @@ -980,6 +1366,8 @@ int main(int argc, char*argv[]) { } else wrote_pid_file = 1; + avahi_set_proc_title(argv0, "%s: [%s] starting up", argv0, interface_name); + if (loop(ifindex, start_address) < 0) goto finish; @@ -1018,14 +1406,10 @@ finish: if (wrote_pid_file) daemon_pid_file_remove(); + avahi_free(log_ident); + avahi_free(pid_file_name); + avahi_free(argv0); + avahi_free(interface_name); + return r; } - -/* TODO: - -- chroot/drop privs/caps -- user script -- store last used address -- man page - -*/