4 This file is part of avahi.
6 avahi is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as
8 published by the Free Software Foundation; either version 2.1 of the
9 License, or (at your option) any later version.
11 avahi is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
14 Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with avahi; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
28 #include <sys/socket.h>
29 #include <netpacket/packet.h>
30 #include <net/ethernet.h>
37 #include <sys/types.h>
38 #include <arpa/inet.h>
39 #include <sys/ioctl.h>
49 #include <avahi-common/malloc.h>
50 #include <avahi-common/timeval.h>
52 #include <avahi-daemon/setproctitle.h>
54 #include <libdaemon/dfork.h>
55 #include <libdaemon/dsignal.h>
56 #include <libdaemon/dlog.h>
57 #include <libdaemon/dpid.h>
58 #include <libdaemon/dexec.h>
64 #error "avahi-autoipd is only available on Linux for now"
67 /* An implementation of RFC 3927 */
69 /* Constants from the RFC */
74 #define ANNOUNCE_WAIT 2
75 #define ANNOUNCE_NUM 2
76 #define ANNOUNCE_INTERVAL 2
77 #define MAX_CONFLICTS 10
78 #define RATE_LIMIT_INTERVAL 60
79 #define DEFEND_INTERVAL 10
81 #define IPV4LL_NETWORK 0xA9FE0000L
82 #define IPV4LL_NETMASK 0xFFFF0000L
83 #define IPV4LL_HOSTMASK 0x0000FFFFL
85 #define ETHER_ADDRLEN 6
86 #define ARP_PACKET_SIZE (8+4+4+2*ETHER_ADDRLEN)
88 typedef enum ArpOperation {
93 typedef struct ArpPacketInfo {
94 ArpOperation operation;
96 uint32_t sender_ip_address, target_ip_address;
97 uint8_t sender_hw_address[ETHER_ADDRLEN], target_hw_address[ETHER_ADDRLEN];
100 static State state = STATE_START;
101 static int n_iteration = 0;
102 static int n_conflict = 0;
104 static char *interface_name = NULL;
105 static char *pid_file_name = NULL;
106 static uint32_t start_address = 0;
107 static char *argv0 = NULL;
108 static int daemonize = 0;
109 static int wait_for_address = 0;
110 static int use_syslog = 0;
111 static int debug = 0;
112 static int modify_proc_title = 1;
113 static int force_bind = 0;
115 static int no_chroot = 0;
117 static int no_drop_root = 0;
118 static int wrote_pid_file = 0;
127 } command = DAEMON_RUN;
129 typedef enum CalloutEvent {
137 static const char * const callout_event_table[CALLOUT_MAX] = {
138 [CALLOUT_BIND] = "BIND",
139 [CALLOUT_CONFLICT] = "CONFLICT",
140 [CALLOUT_UNBIND] = "UNBIND",
141 [CALLOUT_STOP] = "STOP"
144 typedef struct CalloutEventInfo {
150 #define RANDOM_DEVICE "/dev/urandom"
152 #define DEBUG(x) do {\
158 static void init_rand_seed(void) {
162 /* Try to initialize seed from /dev/urandom, to make it a little
163 * less predictable, and to make sure that multiple machines
164 * booted at the same time choose different random seeds. */
165 if ((fd = open(RANDOM_DEVICE, O_RDONLY)) >= 0) {
166 read(fd, &seed, sizeof(seed));
170 /* If the initialization failed by some reason, we add the time to the seed */
171 seed ^= (unsigned) time(NULL);
176 static uint32_t pick_addr(uint32_t old_addr) {
180 unsigned r = (unsigned) rand();
182 /* Reduce to 16 bits */
184 r = (r >> 16) ^ (r & 0xFFFF);
186 addr = htonl(IPV4LL_NETWORK | (uint32_t) r);
188 } while (addr == old_addr);
193 static void* packet_new(const ArpPacketInfo *info, size_t *packet_len) {
198 assert(info->operation == ARP_REQUEST || info->operation == ARP_RESPONSE);
200 *packet_len = ARP_PACKET_SIZE;
201 r = avahi_new0(uint8_t, *packet_len);
203 r[1] = 1; /* HTYPE */
204 r[2] = 8; /* PTYPE */
205 r[4] = ETHER_ADDRLEN; /* HLEN */
207 r[7] = (uint8_t) info->operation;
209 memcpy(r+8, info->sender_hw_address, ETHER_ADDRLEN);
210 memcpy(r+14, &info->sender_ip_address, 4);
211 memcpy(r+18, info->target_hw_address, ETHER_ADDRLEN);
212 memcpy(r+24, &info->target_ip_address, 4);
217 static void *packet_new_probe(uint32_t ip_address, const uint8_t*hw_address, size_t *packet_len) {
220 memset(&info, 0, sizeof(info));
221 info.operation = ARP_REQUEST;
222 memcpy(info.sender_hw_address, hw_address, ETHER_ADDRLEN);
223 info.target_ip_address = ip_address;
225 return packet_new(&info, packet_len);
228 static void *packet_new_announcement(uint32_t ip_address, const uint8_t* hw_address, size_t *packet_len) {
231 memset(&info, 0, sizeof(info));
232 info.operation = ARP_REQUEST;
233 memcpy(info.sender_hw_address, hw_address, ETHER_ADDRLEN);
234 info.target_ip_address = ip_address;
235 info.sender_ip_address = ip_address;
237 return packet_new(&info, packet_len);
240 static int packet_parse(const void *data, size_t packet_len, ArpPacketInfo *info) {
241 const uint8_t *p = data;
245 if (packet_len < ARP_PACKET_SIZE)
248 /* Check HTYPE and PTYPE */
249 if (p[0] != 0 || p[1] != 1 || p[2] != 8 || p[3] != 0)
252 /* Check HLEN, PLEN, OPERATION */
253 if (p[4] != ETHER_ADDRLEN || p[5] != 4 || p[6] != 0 || (p[7] != 1 && p[7] != 2))
256 info->operation = p[7];
257 memcpy(info->sender_hw_address, p+8, ETHER_ADDRLEN);
258 memcpy(&info->sender_ip_address, p+14, 4);
259 memcpy(info->target_hw_address, p+18, ETHER_ADDRLEN);
260 memcpy(&info->target_ip_address, p+24, 4);
265 static void set_state(State st, int reset_counter, uint32_t address) {
266 static const char* const state_table[] = {
267 [STATE_START] = "START",
268 [STATE_WAITING_PROBE] = "WAITING_PROBE",
269 [STATE_PROBING] = "PROBING",
270 [STATE_WAITING_ANNOUNCE] = "WAITING_ANNOUNCE",
271 [STATE_ANNOUNCING] = "ANNOUNCING",
272 [STATE_RUNNING] = "RUNNING",
273 [STATE_SLEEPING] = "SLEEPING"
277 assert(st < STATE_MAX);
279 if (st == state && !reset_counter) {
281 DEBUG(daemon_log(LOG_DEBUG, "State iteration %s-%i", state_table[state], n_iteration));
283 DEBUG(daemon_log(LOG_DEBUG, "State transition %s-%i -> %s-0", state_table[state], n_iteration, state_table[st]));
288 if (state == STATE_SLEEPING)
289 avahi_set_proc_title(argv0, "%s: [%s] sleeping", argv0, interface_name);
290 else if (state == STATE_ANNOUNCING)
291 avahi_set_proc_title(argv0, "%s: [%s] announcing %s", argv0, interface_name, inet_ntop(AF_INET, &address, buf, sizeof(buf)));
292 else if (state == STATE_RUNNING)
293 avahi_set_proc_title(argv0, "%s: [%s] bound %s", argv0, interface_name, inet_ntop(AF_INET, &address, buf, sizeof(buf)));
295 avahi_set_proc_title(argv0, "%s: [%s] probing %s", argv0, interface_name, inet_ntop(AF_INET, &address, buf, sizeof(buf)));
298 static int interface_up(int iface) {
302 if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
303 daemon_log(LOG_ERR, "socket() failed: %s", strerror(errno));
307 memset(&ifreq, 0, sizeof(ifreq));
308 if (!if_indextoname(iface, ifreq.ifr_name)) {
309 daemon_log(LOG_ERR, "if_indextoname() failed: %s", strerror(errno));
313 if (ioctl(fd, SIOCGIFFLAGS, &ifreq) < 0) {
314 daemon_log(LOG_ERR, "SIOCGIFFLAGS failed: %s", strerror(errno));
318 ifreq.ifr_flags |= IFF_UP;
320 if (ioctl(fd, SIOCSIFFLAGS, &ifreq) < 0) {
321 daemon_log(LOG_ERR, "SIOCSIFFLAGS failed: %s", strerror(errno));
336 static int open_socket(int iface, uint8_t *hw_address) {
338 struct sockaddr_ll sa;
341 if (interface_up(iface) < 0)
344 if ((fd = socket(PF_PACKET, SOCK_DGRAM, 0)) < 0) {
345 daemon_log(LOG_ERR, "socket() failed: %s", strerror(errno));
349 memset(&sa, 0, sizeof(sa));
350 sa.sll_family = AF_PACKET;
351 sa.sll_protocol = htons(ETH_P_ARP);
352 sa.sll_ifindex = iface;
354 if (bind(fd, (struct sockaddr*) &sa, sizeof(sa)) < 0) {
355 daemon_log(LOG_ERR, "bind() failed: %s", strerror(errno));
360 if (getsockname(fd, (struct sockaddr*) &sa, &sa_len) < 0) {
361 daemon_log(LOG_ERR, "getsockname() failed: %s", strerror(errno));
365 if (sa.sll_halen != ETHER_ADDRLEN) {
366 daemon_log(LOG_ERR, "getsockname() returned invalid hardware address.");
370 memcpy(hw_address, sa.sll_addr, ETHER_ADDRLEN);
381 static int send_packet(int fd, int iface, void *packet, size_t packet_len) {
382 struct sockaddr_ll sa;
386 assert(packet_len > 0);
388 memset(&sa, 0, sizeof(sa));
389 sa.sll_family = AF_PACKET;
390 sa.sll_protocol = htons(ETH_P_ARP);
391 sa.sll_ifindex = iface;
392 sa.sll_halen = ETHER_ADDRLEN;
393 memset(sa.sll_addr, 0xFF, ETHER_ADDRLEN);
395 if (sendto(fd, packet, packet_len, 0, (struct sockaddr*) &sa, sizeof(sa)) < 0) {
396 daemon_log(LOG_ERR, "sendto() failed: %s", strerror(errno));
403 static int recv_packet(int fd, void **packet, size_t *packet_len) {
405 struct sockaddr_ll sa;
415 if (ioctl(fd, FIONREAD, &s) < 0) {
416 daemon_log(LOG_ERR, "FIONREAD failed: %s", strerror(errno));
423 *packet = avahi_new(uint8_t, s);
426 if ((r = recvfrom(fd, *packet, s, 0, (struct sockaddr*) &sa, &sa_len)) < 0) {
427 daemon_log(LOG_ERR, "recvfrom() failed: %s", strerror(errno));
431 *packet_len = (size_t) r;
444 int is_ll_address(uint32_t addr) {
445 return (ntohl(addr) & IPV4LL_NETMASK) == IPV4LL_NETWORK;
448 static struct timeval *elapse_time(struct timeval *tv, unsigned msec, unsigned jitter) {
451 gettimeofday(tv, NULL);
454 avahi_timeval_add(tv, (AvahiUsec) msec*1000);
457 avahi_timeval_add(tv, (AvahiUsec) (jitter*1000.0*rand()/(RAND_MAX+1.0)));
462 static FILE* fork_dispatcher(void) {
468 daemon_log(LOG_ERR, "pipe() failed: %s", strerror(errno));
472 if ((pid = fork()) < 0)
478 /* Please note that the signal pipe is not closed at this
479 * point, signals will thus be dispatched in the main
482 daemon_retval_done();
486 avahi_set_proc_title(argv0, "%s: [%s] callout dispatcher", argv0, interface_name);
490 if (!(f = fdopen(fds[0], "r"))) {
491 daemon_log(LOG_ERR, "fdopen() failed: %s", strerror(errno));
492 goto dispatcher_fail;
496 CalloutEventInfo info;
497 char name[IFNAMSIZ], buf[64];
500 if (fread(&info, sizeof(info), 1, f) != 1) {
504 daemon_log(LOG_ERR, "fread() failed: %s", strerror(errno));
505 goto dispatcher_fail;
508 assert(info.event <= CALLOUT_MAX);
510 if (!if_indextoname(info.ifindex, name)) {
511 daemon_log(LOG_ERR, "if_indextoname() failed: %s", strerror(errno));
515 if (daemon_exec("/", &k,
516 AVAHI_IPCONF_SCRIPT, AVAHI_IPCONF_SCRIPT,
517 callout_event_table[info.event],
519 inet_ntop(AF_INET, &info.address, buf, sizeof(buf)), NULL) < 0) {
521 daemon_log(LOG_ERR, "Failed to run script: %s", strerror(errno));
526 daemon_log(LOG_WARNING, "Script execution failed with return value %i", k);
537 /* If the main process is trapped inside a chroot() we have to
538 * remove the PID file for it */
540 if (!no_chroot && wrote_pid_file)
541 daemon_pid_file_remove();
552 if (!(ret = fdopen(fds[1], "w"))) {
553 daemon_log(LOG_ERR, "fdopen() failed: %s", strerror(errno));
568 static int do_callout(FILE *f, CalloutEvent event, int iface, uint32_t addr) {
569 CalloutEventInfo info;
570 char buf[64], ifname[IFNAMSIZ];
572 daemon_log(LOG_INFO, "Callout %s, address %s on interface %s",
573 callout_event_table[event],
574 inet_ntop(AF_INET, &addr, buf, sizeof(buf)),
575 if_indextoname(iface, ifname));
578 info.ifindex = iface;
581 if (fwrite(&info, sizeof(info), 1, f) != 1 || fflush(f) != 0) {
582 daemon_log(LOG_ERR, "Failed to write callout event: %s", strerror(errno));
589 #define set_env(key, value) putenv(avahi_strdup_printf("%s=%s", (key), (value)))
591 static int drop_privs(void) {
597 /* Get user/group ID */
601 if (!(pw = getpwnam(AVAHI_AUTOIPD_USER))) {
602 daemon_log(LOG_ERR, "Failed to find user '"AVAHI_AUTOIPD_USER"'.");
606 if (!(gr = getgrnam(AVAHI_AUTOIPD_GROUP))) {
607 daemon_log(LOG_ERR, "Failed to find group '"AVAHI_AUTOIPD_GROUP"'.");
611 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);
614 /* Create directory */
616 r = mkdir(AVAHI_IPDATA_DIR, 0755);
619 if (r < 0 && errno != EEXIST) {
620 daemon_log(LOG_ERR, "mkdir(\""AVAHI_IPDATA_DIR"\"): %s", strerror(errno));
624 /* Convey working directory */
629 chown(AVAHI_IPDATA_DIR, pw->pw_uid, gr->gr_gid);
631 if (stat(AVAHI_IPDATA_DIR, &st) < 0) {
632 daemon_log(LOG_ERR, "stat(): %s\n", strerror(errno));
636 if (!S_ISDIR(st.st_mode) || st.st_uid != pw->pw_uid || st.st_gid != gr->gr_gid) {
637 daemon_log(LOG_ERR, "Failed to create runtime directory "AVAHI_IPDATA_DIR".");
645 if (chroot(AVAHI_IPDATA_DIR) < 0) {
646 daemon_log(LOG_ERR, "Failed to chroot(): %s", strerror(errno));
650 daemon_log(LOG_INFO, "Successfully called chroot().");
653 /* Since we are now trapped inside a chroot we cannot remove
654 * the pid file anymore, the helper process will do that for us. */
662 if (initgroups(AVAHI_AUTOIPD_USER, gr->gr_gid) != 0) {
663 daemon_log(LOG_ERR, "Failed to change group list: %s", strerror(errno));
667 #if defined(HAVE_SETRESGID)
668 r = setresgid(gr->gr_gid, gr->gr_gid, gr->gr_gid);
669 #elif defined(HAVE_SETEGID)
670 if ((r = setgid(gr->gr_gid)) >= 0)
671 r = setegid(gr->gr_gid);
672 #elif defined(HAVE_SETREGID)
673 r = setregid(gr->gr_gid, gr->gr_gid);
675 #error "No API to drop priviliges"
679 daemon_log(LOG_ERR, "Failed to change GID: %s", strerror(errno));
683 #if defined(HAVE_SETRESUID)
684 r = setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid);
685 #elif defined(HAVE_SETEUID)
686 if ((r = setuid(pw->pw_uid)) >= 0)
687 r = seteuid(pw->pw_uid);
688 #elif defined(HAVE_SETREUID)
689 r = setreuid(pw->pw_uid, pw->pw_uid);
691 #error "No API to drop priviliges"
695 daemon_log(LOG_ERR, "Failed to change UID: %s", strerror(errno));
699 set_env("USER", pw->pw_name);
700 set_env("LOGNAME", pw->pw_name);
701 set_env("HOME", pw->pw_dir);
703 daemon_log(LOG_ERR, "Successfully dropped root privileges.");
709 static int loop(int iface, uint32_t addr) {
717 int fd = -1, ret = -1;
718 struct timeval next_wakeup;
719 int next_wakeup_valid = 0;
721 void *in_packet = NULL;
722 size_t in_packet_len;
723 void *out_packet = NULL;
724 size_t out_packet_len;
725 uint8_t hw_address[ETHER_ADDRLEN];
726 struct pollfd pollfds[FD_MAX];
728 Event event = EVENT_NULL;
729 int retval_sent = !daemonize;
731 FILE *dispatcher = NULL;
733 daemon_signal_init(SIGINT, SIGTERM, SIGCHLD, SIGHUP,0);
735 if (!(dispatcher = fork_dispatcher()))
738 if ((fd = open_socket(iface, hw_address)) < 0)
741 if ((iface_fd = iface_init(iface)) < 0)
744 if (drop_privs() < 0)
749 else if (iface_get_initial_state(&st) < 0)
752 if (addr && !is_ll_address(addr)) {
753 daemon_log(LOG_WARNING, "Requested address %s is not from IPv4LL range 169.254/16, ignoring.", inet_ntop(AF_INET, &addr, buf, sizeof(buf)));
761 for (i = 0; i < ETHER_ADDRLEN; i++)
762 a += hw_address[i]*i;
764 addr = htonl(IPV4LL_NETWORK | (uint32_t) a);
767 set_state(st, 1, addr);
769 daemon_log(LOG_INFO, "Starting with address %s", inet_ntop(AF_INET, &addr, buf, sizeof(buf)));
771 if (state == STATE_SLEEPING)
772 daemon_log(LOG_INFO, "Routable address already assigned, sleeping.");
774 if (!retval_sent && (!wait_for_address || state == STATE_SLEEPING)) {
775 daemon_retval_send(0);
779 memset(pollfds, 0, sizeof(pollfds));
780 pollfds[FD_ARP].fd = fd;
781 pollfds[FD_ARP].events = POLLIN;
782 pollfds[FD_IFACE].fd = iface_fd;
783 pollfds[FD_IFACE].events = POLLIN;
784 pollfds[FD_SIGNAL].fd = daemon_signal_fd();
785 pollfds[FD_SIGNAL].events = POLLIN;
791 if (state == STATE_START) {
793 /* First, wait a random time */
794 set_state(STATE_WAITING_PROBE, 1, addr);
796 elapse_time(&next_wakeup, 0, PROBE_WAIT*1000);
797 next_wakeup_valid = 1;
799 } else if ((state == STATE_WAITING_PROBE && event == EVENT_TIMEOUT) ||
800 (state == STATE_PROBING && event == EVENT_TIMEOUT && n_iteration < PROBE_NUM-2)) {
803 out_packet = packet_new_probe(addr, hw_address, &out_packet_len);
804 set_state(STATE_PROBING, 0, addr);
806 elapse_time(&next_wakeup, PROBE_MIN*1000, (PROBE_MAX-PROBE_MIN)*1000);
807 next_wakeup_valid = 1;
809 } else if (state == STATE_PROBING && event == EVENT_TIMEOUT && n_iteration >= PROBE_NUM-2) {
811 /* Send the last probe */
812 out_packet = packet_new_probe(addr, hw_address, &out_packet_len);
813 set_state(STATE_WAITING_ANNOUNCE, 1, addr);
815 elapse_time(&next_wakeup, ANNOUNCE_WAIT*1000, 0);
816 next_wakeup_valid = 1;
818 } else if ((state == STATE_WAITING_ANNOUNCE && event == EVENT_TIMEOUT) ||
819 (state == STATE_ANNOUNCING && event == EVENT_TIMEOUT && n_iteration < ANNOUNCE_NUM-1)) {
821 /* Send announcement packet */
822 out_packet = packet_new_announcement(addr, hw_address, &out_packet_len);
823 set_state(STATE_ANNOUNCING, 0, addr);
825 elapse_time(&next_wakeup, ANNOUNCE_INTERVAL*1000, 0);
826 next_wakeup_valid = 1;
828 if (n_iteration == 0) {
829 if (do_callout(dispatcher, CALLOUT_BIND, iface, addr) < 0)
835 daemon_retval_send(0);
840 } else if ((state == STATE_ANNOUNCING && event == EVENT_TIMEOUT && n_iteration >= ANNOUNCE_NUM-1)) {
842 daemon_log(LOG_INFO, "Successfully claimed IP address %s", inet_ntop(AF_INET, &addr, buf, sizeof(buf)));
843 set_state(STATE_RUNNING, 0, addr);
845 next_wakeup_valid = 0;
847 } else if (event == EVENT_PACKET) {
852 if (packet_parse(in_packet, in_packet_len, &info) < 0)
853 daemon_log(LOG_WARNING, "Failed to parse incoming ARP packet.");
857 if (info.sender_ip_address == addr) {
858 /* Normal conflict */
860 daemon_log(LOG_INFO, "Recieved conflicting normal ARP packet.");
861 } else if (state == STATE_WAITING_PROBE || state == STATE_PROBING || state == STATE_WAITING_ANNOUNCE) {
863 conflict = info.target_ip_address == addr && memcmp(hw_address, info.sender_hw_address, ETHER_ADDRLEN);
864 daemon_log(LOG_INFO, "Recieved conflicting probe ARP packet.");
869 if (state == STATE_RUNNING || state == STATE_ANNOUNCING)
870 if (do_callout(dispatcher, CALLOUT_CONFLICT, iface, addr) < 0)
873 /* Pick a new address */
874 addr = pick_addr(addr);
876 daemon_log(LOG_INFO, "Trying address %s", inet_ntop(AF_INET, &addr, buf, sizeof(buf)));
880 set_state(STATE_WAITING_PROBE, 1, addr);
882 if (n_conflict >= MAX_CONFLICTS) {
883 daemon_log(LOG_WARNING, "Got too many conflicts, rate limiting new probes.");
884 elapse_time(&next_wakeup, RATE_LIMIT_INTERVAL*1000, PROBE_WAIT*1000);
886 elapse_time(&next_wakeup, 0, PROBE_WAIT*1000);
888 next_wakeup_valid = 1;
890 DEBUG(daemon_log(LOG_DEBUG, "Ignoring irrelevant ARP packet."));
893 } else if (event == EVENT_ROUTABLE_ADDR_CONFIGURED) {
895 daemon_log(LOG_INFO, "A routable address has been configured.");
897 if (state == STATE_RUNNING || state == STATE_ANNOUNCING)
898 if (do_callout(dispatcher, CALLOUT_UNBIND, iface, addr) < 0)
902 daemon_retval_send(0);
906 set_state(STATE_SLEEPING, 1, addr);
907 next_wakeup_valid = 0;
909 } else if (event == EVENT_ROUTABLE_ADDR_UNCONFIGURED && state == STATE_SLEEPING && !force_bind) {
911 daemon_log(LOG_INFO, "No longer a routable address configured, restarting probe process.");
913 set_state(STATE_WAITING_PROBE, 1, addr);
915 elapse_time(&next_wakeup, 0, PROBE_WAIT*1000);
916 next_wakeup_valid = 1;
918 } else if (event == EVENT_REFRESH_REQUEST && state == STATE_RUNNING && !force_bind) {
920 /* The user requested a reannouncing of the address by a SIGHUP */
921 daemon_log(LOG_INFO, "Reannouncing address.");
923 /* Send announcement packet */
924 out_packet = packet_new_announcement(addr, hw_address, &out_packet_len);
925 set_state(STATE_ANNOUNCING, 1, addr);
927 elapse_time(&next_wakeup, ANNOUNCE_INTERVAL*1000, 0);
928 next_wakeup_valid = 1;
932 DEBUG(daemon_log(LOG_DEBUG, "sending..."));
934 if (send_packet(fd, iface, out_packet, out_packet_len) < 0)
937 avahi_free(out_packet);
942 avahi_free(in_packet);
949 if (next_wakeup_valid) {
950 usec = avahi_age(&next_wakeup);
951 timeout = usec < 0 ? (int) (-usec/1000) : 0;
954 DEBUG(daemon_log(LOG_DEBUG, "sleeping %ims", timeout));
956 while ((r = poll(pollfds, FD_MAX, timeout)) < 0 && errno == EINTR)
960 daemon_log(LOG_ERR, "poll() failed: %s", strerror(r));
963 event = EVENT_TIMEOUT;
964 next_wakeup_valid = 0;
968 if (pollfds[FD_ARP].revents) {
970 if (pollfds[FD_ARP].revents == POLLERR) {
971 /* The interface is probably down, let's recreate our socket */
975 if ((fd = open_socket(iface, hw_address)) < 0)
978 pollfds[FD_ARP].fd = fd;
982 assert(pollfds[FD_ARP].revents == POLLIN);
984 if (recv_packet(fd, &in_packet, &in_packet_len) < 0)
988 event = EVENT_PACKET;
992 if (event == EVENT_NULL &&
993 pollfds[FD_IFACE].revents) {
995 assert(pollfds[FD_IFACE].revents == POLLIN);
997 if (iface_process(&event) < 0)
1001 if (event == EVENT_NULL &&
1002 pollfds[FD_SIGNAL].revents) {
1005 assert(pollfds[FD_SIGNAL].revents == POLLIN);
1007 if ((sig = daemon_signal_next()) <= 0) {
1008 daemon_log(LOG_ERR, "daemon_signal_next() failed");
1015 daemon_log(LOG_INFO, "Got %s, quitting.", sig == SIGINT ? "SIGINT" : "SIGTERM");
1020 waitpid(-1, NULL, WNOHANG);
1024 event = EVENT_REFRESH_REQUEST;
1036 if (state == STATE_RUNNING || state == STATE_ANNOUNCING)
1037 do_callout(dispatcher, CALLOUT_STOP, iface, addr);
1039 avahi_free(out_packet);
1040 avahi_free(in_packet);
1048 if (daemonize && !retval_sent)
1049 daemon_retval_send(ret);
1058 static void help(FILE *f, const char *a0) {
1060 "%s [options] INTERFACE\n"
1061 " -h --help Show this help\n"
1062 " -D --daemonize Daemonize after startup\n"
1063 " -s --syslog Write log messages to syslog(3) instead of STDERR\n"
1064 " -k --kill Kill a running daemon\n"
1065 " -r --refresh Request a running daemon to refresh it's IP address\n"
1066 " -c --check Return 0 if a daemon is already running\n"
1067 " -V --version Show version\n"
1068 " -S --start=ADDRESS Start with this address from the IPv4LL range\n"
1070 " -w --wait Wait until an address has been acquired before\n"
1072 " --force-bind Assign an IPv4LL address even if routable address\n"
1073 " is already assigned\n"
1074 " --no-drop-root Don't drop privileges\n"
1076 " --no-chroot Don't chroot()\n"
1078 " --no-proc-title Don't modify process title\n"
1079 " --debug Increase verbosity\n",
1083 static int parse_command_line(int argc, char *argv[]) {
1087 OPTION_NO_PROC_TITLE = 256,
1090 OPTION_NO_DROP_ROOT,
1096 static const struct option long_options[] = {
1097 { "help", no_argument, NULL, 'h' },
1098 { "daemonize", no_argument, NULL, 'D' },
1099 { "syslog", no_argument, NULL, 's' },
1100 { "kill", no_argument, NULL, 'k' },
1101 { "refresh", no_argument, NULL, 'r' },
1102 { "check", no_argument, NULL, 'c' },
1103 { "version", no_argument, NULL, 'V' },
1104 { "start", required_argument, NULL, 'S' },
1105 { "wait", no_argument, NULL, 'w' },
1106 { "force-bind", no_argument, NULL, OPTION_FORCE_BIND },
1107 { "no-drop-root", no_argument, NULL, OPTION_NO_DROP_ROOT },
1109 { "no-chroot", no_argument, NULL, OPTION_NO_CHROOT },
1111 { "no-proc-title", no_argument, NULL, OPTION_NO_PROC_TITLE },
1112 { "debug", no_argument, NULL, OPTION_DEBUG },
1113 { NULL, 0, NULL, 0 }
1117 while ((c = getopt_long(argc, argv, "hDskrcVS:w", long_options, NULL)) >= 0) {
1124 command = DAEMON_HELP;
1130 command = DAEMON_KILL;
1133 command = DAEMON_VERSION;
1136 command = DAEMON_REFRESH;
1139 command = DAEMON_CHECK;
1143 if ((start_address = inet_addr(optarg)) == (uint32_t) -1) {
1144 fprintf(stderr, "Failed to parse IP address '%s'.", optarg);
1149 wait_for_address = 1;
1152 case OPTION_NO_PROC_TITLE:
1153 modify_proc_title = 0;
1160 case OPTION_FORCE_BIND:
1164 case OPTION_NO_DROP_ROOT:
1169 case OPTION_NO_CHROOT:
1175 fprintf(stderr, "Invalid command line argument: %c\n", c);
1180 if (command == DAEMON_RUN ||
1181 command == DAEMON_KILL ||
1182 command == DAEMON_REFRESH ||
1183 command == DAEMON_CHECK) {
1185 if (optind >= argc) {
1186 fprintf(stderr, "Missing interface name.\n");
1190 interface_name = avahi_strdup(argv[optind++]);
1193 if (optind != argc) {
1194 fprintf(stderr, "Too many arguments\n");
1201 static const char* pid_file_proc(void) {
1202 return pid_file_name;
1205 int main(int argc, char*argv[]) {
1207 char *log_ident = NULL;
1209 signal(SIGPIPE, SIG_IGN);
1211 if ((argv0 = strrchr(argv[0], '/')))
1212 argv0 = avahi_strdup(argv0 + 1);
1214 argv0 = avahi_strdup(argv[0]);
1216 daemon_log_ident = argv0;
1218 if (parse_command_line(argc, argv) < 0)
1221 if (modify_proc_title)
1222 avahi_init_proc_title(argc, argv);
1224 daemon_log_ident = log_ident = avahi_strdup_printf("%s(%s)", argv0, interface_name);
1225 daemon_pid_file_proc = pid_file_proc;
1226 pid_file_name = avahi_strdup_printf(AVAHI_RUNTIME_DIR"/avahi-autoipd.%s.pid", interface_name);
1228 if (command == DAEMON_RUN) {
1234 if ((ifindex = if_nametoindex(interface_name)) <= 0) {
1235 daemon_log(LOG_ERR, "Failed to get index for interface name '%s': %s", interface_name, strerror(errno));
1239 if (getuid() != 0) {
1240 daemon_log(LOG_ERR, "This program is intended to be run as root.");
1244 if ((pid = daemon_pid_file_is_running()) >= 0) {
1245 daemon_log(LOG_ERR, "Daemon already running on PID %u", pid);
1250 daemon_retval_init();
1252 if ((pid = daemon_fork()) < 0)
1254 else if (pid != 0) {
1258 if ((ret = daemon_retval_wait(20)) < 0) {
1259 daemon_log(LOG_ERR, "Could not receive return value from daemon process.");
1270 if (use_syslog || daemonize)
1271 daemon_log_use = DAEMON_LOG_SYSLOG;
1275 if (daemon_pid_file_create() < 0) {
1276 daemon_log(LOG_ERR, "Failed to create PID file: %s", strerror(errno));
1279 daemon_retval_send(1);
1284 avahi_set_proc_title(argv0, "%s: [%s] starting up", argv0, interface_name);
1286 if (loop(ifindex, start_address) < 0)
1290 } else if (command == DAEMON_HELP) {
1291 help(stdout, argv0);
1294 } else if (command == DAEMON_VERSION) {
1295 printf("%s "PACKAGE_VERSION"\n", argv0);
1298 } else if (command == DAEMON_KILL) {
1299 if (daemon_pid_file_kill_wait(SIGTERM, 5) < 0) {
1300 daemon_log(LOG_WARNING, "Failed to kill daemon: %s", strerror(errno));
1305 } else if (command == DAEMON_REFRESH) {
1306 if (daemon_pid_file_kill(SIGHUP) < 0) {
1307 daemon_log(LOG_WARNING, "Failed to kill daemon: %s", strerror(errno));
1312 } else if (command == DAEMON_CHECK)
1313 r = (daemon_pid_file_is_running() >= 0) ? 0 : 1;
1319 daemon_retval_done();
1322 daemon_pid_file_remove();
1324 avahi_free(log_ident);
1325 avahi_free(pid_file_name);
1327 avahi_free(interface_name);
1334 - store last used address