1714 lines
46 KiB
C
1714 lines
46 KiB
C
/***
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This file is part of avahi.
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avahi is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation; either version 2.1 of the
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License, or (at your option) any later version.
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avahi is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
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Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with avahi; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
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USA.
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***/
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#include <sys/param.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/ioctl.h>
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#include <sys/socket.h>
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#include <sys/wait.h>
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#ifdef __FreeBSD__
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#include <sys/sysctl.h>
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#endif
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#ifdef __linux__
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#include <netpacket/packet.h>
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#endif
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#include <net/ethernet.h>
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#include <net/if.h>
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#ifdef __FreeBSD__
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#include <net/if_dl.h>
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#include <net/route.h>
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#endif
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#include <arpa/inet.h>
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#include <assert.h>
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#include <errno.h>
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#include <inttypes.h>
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#include <fcntl.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <signal.h>
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#include <string.h>
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#include <time.h>
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#include <getopt.h>
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|
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#include <grp.h>
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#include <poll.h>
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#include <pwd.h>
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#include <unistd.h>
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#ifndef __linux__
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#include <pcap.h>
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/* Old versions of PCAP defined it as D_IN */
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#ifndef PCAP_D_IN
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#define PCAP_D_IN D_IN
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#endif
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#endif
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#include "avahi-common/avahi-malloc.h"
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#include <avahi-common/timeval.h>
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#include <avahi-daemon/setproctitle.h>
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#include <libdaemon/dfork.h>
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#include <libdaemon/dsignal.h>
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#include <libdaemon/dlog.h>
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#include <libdaemon/dpid.h>
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#include <libdaemon/dexec.h>
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#include "main.h"
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#include "iface.h"
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/* An implementation of RFC 3927 */
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/* Constants from the RFC */
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#define PROBE_WAIT 1
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#define PROBE_NUM 3
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#define PROBE_MIN 1
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#define PROBE_MAX 2
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#define ANNOUNCE_WAIT 2
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#define ANNOUNCE_NUM 2
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#define ANNOUNCE_INTERVAL 2
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#define MAX_CONFLICTS 10
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#define RATE_LIMIT_INTERVAL 60
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#define DEFEND_INTERVAL 10
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#define IPV4LL_NETWORK 0xA9FE0000L
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#define IPV4LL_NETMASK 0xFFFF0000L
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#define IPV4LL_HOSTMASK 0x0000FFFFL
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#define IPV4LL_BROADCAST 0xA9FEFFFFL
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#define ETHER_ADDRLEN 6
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#define ETHER_HDR_SIZE (2+2*ETHER_ADDRLEN)
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#define ARP_PACKET_SIZE (8+4+4+2*ETHER_ADDRLEN)
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typedef enum ArpOperation {
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ARP_REQUEST = 1,
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ARP_RESPONSE = 2
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} ArpOperation;
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typedef struct ArpPacketInfo {
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ArpOperation operation;
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uint32_t sender_ip_address, target_ip_address;
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uint8_t sender_hw_address[ETHER_ADDRLEN], target_hw_address[ETHER_ADDRLEN];
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} ArpPacketInfo;
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typedef struct ArpPacket {
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uint8_t *ether_header;
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uint8_t *ether_payload;
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} ArpPacket;
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static State state = STATE_START;
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static int n_iteration = 0;
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static int n_conflict = 0;
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static char *interface_name = NULL;
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static char *pid_file_name = NULL;
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static uint32_t start_address = 0;
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static char *argv0 = NULL;
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static int daemonize = 0;
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static int wait_for_address = 0;
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static int use_syslog = 0;
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static int debug = 0;
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static int modify_proc_title = 1;
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static int force_bind = 0;
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#ifdef HAVE_CHROOT
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static int no_chroot = 0;
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#endif
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static int no_drop_root = 0;
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static int wrote_pid_file = 0;
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static char *action_script = NULL;
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static enum {
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DAEMON_RUN,
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DAEMON_KILL,
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DAEMON_REFRESH,
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DAEMON_VERSION,
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DAEMON_HELP,
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DAEMON_CHECK
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} command = DAEMON_RUN;
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typedef enum CalloutEvent {
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CALLOUT_BIND,
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CALLOUT_CONFLICT,
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CALLOUT_UNBIND,
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CALLOUT_STOP,
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CALLOUT_MAX
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} CalloutEvent;
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static const char * const callout_event_table[CALLOUT_MAX] = {
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[CALLOUT_BIND] = "BIND",
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[CALLOUT_CONFLICT] = "CONFLICT",
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[CALLOUT_UNBIND] = "UNBIND",
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[CALLOUT_STOP] = "STOP"
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};
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typedef struct CalloutEventInfo {
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CalloutEvent event;
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uint32_t address;
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int ifindex;
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} CalloutEventInfo;
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#define RANDOM_DEVICE "/dev/urandom"
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#define DEBUG(x) \
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do { \
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if (debug) { \
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x; \
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} \
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} while (0)
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static void init_rand_seed(void) {
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int fd;
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unsigned seed = 0;
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/* Try to initialize seed from /dev/urandom, to make it a little
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* less predictable, and to make sure that multiple machines
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* booted at the same time choose different random seeds. */
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if ((fd = open(RANDOM_DEVICE, O_RDONLY)) >= 0) {
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read(fd, &seed, sizeof(seed));
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close(fd);
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}
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/* If the initialization failed by some reason, we add the time to the seed */
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seed ^= (unsigned) time(NULL);
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srand(seed);
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}
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static uint32_t pick_addr(uint32_t old_addr) {
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uint32_t addr;
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do {
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unsigned r = (unsigned) rand();
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/* Reduce to 16 bits */
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while (r > 0xFFFF)
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r = (r >> 16) ^ (r & 0xFFFF);
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addr = htonl(IPV4LL_NETWORK | (uint32_t) r);
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} while (addr == old_addr || !is_ll_address(addr));
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return addr;
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}
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static int load_address(const char *fn, uint32_t *addr) {
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FILE *f;
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unsigned a, b, c, d;
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assert(fn);
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assert(addr);
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if (!(f = fopen(fn, "r"))) {
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if (errno == ENOENT) {
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*addr = 0;
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return 0;
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}
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daemon_log(LOG_ERR, "fopen() failed: %s", strerror(errno));
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goto fail;
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}
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if (fscanf(f, "%u.%u.%u.%u\n", &a, &b, &c, &d) != 4) {
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daemon_log(LOG_ERR, "Parse failure");
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goto fail;
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}
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fclose(f);
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*addr = htonl((a << 24) | (b << 16) | (c << 8) | d);
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return 0;
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fail:
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if (f)
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fclose(f);
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return -1;
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}
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static int save_address(const char *fn, uint32_t addr) {
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FILE *f;
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char buf[32];
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mode_t u;
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assert(fn);
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u = umask(0033);
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if (!(f = fopen(fn, "w"))) {
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daemon_log(LOG_ERR, "fopen() failed: %s", strerror(errno));
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goto fail;
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}
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umask(u);
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fprintf(f, "%s\n", inet_ntop(AF_INET, &addr, buf, sizeof (buf)));
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fclose(f);
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return 0;
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fail:
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if (f)
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fclose(f);
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umask(u);
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return -1;
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}
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/*
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* Allocate a buffer with two pointers in front, one of which is
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* guaranteed to point ETHER_HDR_SIZE bytes into it.
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*/
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static ArpPacket* packet_new(size_t packet_len) {
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ArpPacket *p;
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uint8_t *b;
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assert(packet_len > 0);
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#ifdef __linux__
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b = avahi_new0(uint8_t, sizeof(struct ArpPacket) + packet_len);
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p = (ArpPacket*) b;
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p->ether_header = NULL;
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p->ether_payload = b + sizeof(struct ArpPacket);
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#else
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b = avahi_new0(uint8_t, sizeof(struct ArpPacket) + ETHER_HDR_SIZE + packet_len);
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p = (ArpPacket*) b;
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p->ether_header = b + sizeof(struct ArpPacket);
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p->ether_payload = b + sizeof(struct ArpPacket) + ETHER_HDR_SIZE;
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#endif
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return p;
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}
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static ArpPacket* packet_new_with_info(const ArpPacketInfo *info, size_t *packet_len) {
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ArpPacket *p = NULL;
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uint8_t *r;
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assert(info);
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assert(info->operation == ARP_REQUEST || info->operation == ARP_RESPONSE);
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assert(packet_len != NULL);
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*packet_len = ARP_PACKET_SIZE;
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p = packet_new(*packet_len);
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r = p->ether_payload;
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r[1] = 1; /* HTYPE */
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r[2] = 8; /* PTYPE */
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r[4] = ETHER_ADDRLEN; /* HLEN */
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r[5] = 4; /* PLEN */
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r[7] = (uint8_t) info->operation;
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memcpy(r+8, info->sender_hw_address, ETHER_ADDRLEN);
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memcpy(r+14, &info->sender_ip_address, 4);
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memcpy(r+18, info->target_hw_address, ETHER_ADDRLEN);
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memcpy(r+24, &info->target_ip_address, 4);
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return p;
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}
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static ArpPacket *packet_new_probe(uint32_t ip_address, const uint8_t*hw_address, size_t *packet_len) {
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ArpPacketInfo info;
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memset(&info, 0, sizeof(info));
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info.operation = ARP_REQUEST;
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memcpy(info.sender_hw_address, hw_address, ETHER_ADDRLEN);
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info.target_ip_address = ip_address;
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return packet_new_with_info(&info, packet_len);
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}
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static ArpPacket *packet_new_announcement(uint32_t ip_address, const uint8_t* hw_address, size_t *packet_len) {
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ArpPacketInfo info;
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memset(&info, 0, sizeof(info));
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info.operation = ARP_REQUEST;
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memcpy(info.sender_hw_address, hw_address, ETHER_ADDRLEN);
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info.target_ip_address = ip_address;
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info.sender_ip_address = ip_address;
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return packet_new_with_info(&info, packet_len);
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}
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static int packet_parse(const ArpPacket *packet, size_t packet_len, ArpPacketInfo *info) {
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const uint8_t *p;
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assert(packet);
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p = (uint8_t *)packet->ether_payload;
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assert(p);
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if (packet_len < ARP_PACKET_SIZE)
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return -1;
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|
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/* Check HTYPE and PTYPE */
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if (p[0] != 0 || p[1] != 1 || p[2] != 8 || p[3] != 0)
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return -1;
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|
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/* Check HLEN, PLEN, OPERATION */
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if (p[4] != ETHER_ADDRLEN || p[5] != 4 || p[6] != 0 || (p[7] != 1 && p[7] != 2))
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return -1;
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info->operation = p[7];
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memcpy(info->sender_hw_address, p+8, ETHER_ADDRLEN);
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memcpy(&info->sender_ip_address, p+14, 4);
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memcpy(info->target_hw_address, p+18, ETHER_ADDRLEN);
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memcpy(&info->target_ip_address, p+24, 4);
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return 0;
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}
|
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|
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static void set_state(State st, int reset_counter, uint32_t address) {
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static const char* const state_table[] = {
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[STATE_START] = "START",
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[STATE_WAITING_PROBE] = "WAITING_PROBE",
|
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[STATE_PROBING] = "PROBING",
|
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[STATE_WAITING_ANNOUNCE] = "WAITING_ANNOUNCE",
|
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[STATE_ANNOUNCING] = "ANNOUNCING",
|
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[STATE_RUNNING] = "RUNNING",
|
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[STATE_SLEEPING] = "SLEEPING"
|
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};
|
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char buf[64];
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|
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assert(st < STATE_MAX);
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|
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if (st == state && !reset_counter) {
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n_iteration++;
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DEBUG(daemon_log(LOG_DEBUG, "State iteration %s-%i", state_table[state], n_iteration));
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} else {
|
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DEBUG(daemon_log(LOG_DEBUG, "State transition %s-%i -> %s-0", state_table[state], n_iteration, state_table[st]));
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state = st;
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n_iteration = 0;
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}
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|
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if (state == STATE_SLEEPING)
|
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avahi_set_proc_title(argv0, "%s: [%s] sleeping", argv0, interface_name);
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else if (state == STATE_ANNOUNCING)
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avahi_set_proc_title(argv0, "%s: [%s] announcing %s", argv0, interface_name, inet_ntop(AF_INET, &address, buf, sizeof(buf)));
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else if (state == STATE_RUNNING)
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avahi_set_proc_title(argv0, "%s: [%s] bound %s", argv0, interface_name, inet_ntop(AF_INET, &address, buf, sizeof(buf)));
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else
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avahi_set_proc_title(argv0, "%s: [%s] probing %s", argv0, interface_name, inet_ntop(AF_INET, &address, buf, sizeof(buf)));
|
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}
|
|
|
|
static int interface_up(int iface) {
|
|
int fd = -1;
|
|
struct ifreq ifreq;
|
|
|
|
if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
|
|
daemon_log(LOG_ERR, "socket() failed: %s", strerror(errno));
|
|
goto fail;
|
|
}
|
|
|
|
memset(&ifreq, 0, sizeof(ifreq));
|
|
if (!if_indextoname(iface, ifreq.ifr_name)) {
|
|
daemon_log(LOG_ERR, "if_indextoname() failed: %s", strerror(errno));
|
|
goto fail;
|
|
}
|
|
|
|
if (ioctl(fd, SIOCGIFFLAGS, &ifreq) < 0) {
|
|
daemon_log(LOG_ERR, "SIOCGIFFLAGS failed: %s", strerror(errno));
|
|
goto fail;
|
|
}
|
|
|
|
ifreq.ifr_flags |= IFF_UP;
|
|
|
|
if (ioctl(fd, SIOCSIFFLAGS, &ifreq) < 0) {
|
|
daemon_log(LOG_ERR, "SIOCSIFFLAGS failed: %s", strerror(errno));
|
|
goto fail;
|
|
}
|
|
|
|
close(fd);
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
if (fd >= 0)
|
|
close(fd);
|
|
|
|
return -1;
|
|
}
|
|
|
|
#ifdef __linux__
|
|
|
|
/* Linux 'packet socket' specific implementation */
|
|
|
|
static int open_socket(int iface, uint8_t *hw_address) {
|
|
int fd = -1;
|
|
struct sockaddr_ll sa;
|
|
socklen_t sa_len;
|
|
|
|
if (interface_up(iface) < 0)
|
|
goto fail;
|
|
|
|
if ((fd = socket(PF_PACKET, SOCK_DGRAM, 0)) < 0) {
|
|
daemon_log(LOG_ERR, "socket() failed: %s", strerror(errno));
|
|
goto fail;
|
|
}
|
|
|
|
memset(&sa, 0, sizeof(sa));
|
|
sa.sll_family = AF_PACKET;
|
|
sa.sll_protocol = htons(ETH_P_ARP);
|
|
sa.sll_ifindex = iface;
|
|
|
|
if (bind(fd, (struct sockaddr*) &sa, sizeof(sa)) < 0) {
|
|
daemon_log(LOG_ERR, "bind() failed: %s", strerror(errno));
|
|
goto fail;
|
|
}
|
|
|
|
sa_len = sizeof(sa);
|
|
if (getsockname(fd, (struct sockaddr*) &sa, &sa_len) < 0) {
|
|
daemon_log(LOG_ERR, "getsockname() failed: %s", strerror(errno));
|
|
goto fail;
|
|
}
|
|
|
|
if (sa.sll_halen != ETHER_ADDRLEN) {
|
|
daemon_log(LOG_ERR, "getsockname() returned invalid hardware address.");
|
|
goto fail;
|
|
}
|
|
|
|
memcpy(hw_address, sa.sll_addr, ETHER_ADDRLEN);
|
|
|
|
return fd;
|
|
|
|
fail:
|
|
if (fd >= 0)
|
|
close(fd);
|
|
|
|
return -1;
|
|
}
|
|
|
|
static int send_packet(int fd, int iface, ArpPacket *packet, size_t packet_len) {
|
|
struct sockaddr_ll sa;
|
|
|
|
assert(fd >= 0);
|
|
assert(packet);
|
|
assert(packet_len > 0);
|
|
|
|
memset(&sa, 0, sizeof(sa));
|
|
sa.sll_family = AF_PACKET;
|
|
sa.sll_protocol = htons(ETH_P_ARP);
|
|
sa.sll_ifindex = iface;
|
|
sa.sll_halen = ETHER_ADDRLEN;
|
|
memset(sa.sll_addr, 0xFF, ETHER_ADDRLEN);
|
|
|
|
if (sendto(fd, packet->ether_payload, packet_len, 0, (struct sockaddr*) &sa, sizeof(sa)) < 0) {
|
|
daemon_log(LOG_ERR, "sendto() failed: %s", strerror(errno));
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int recv_packet(int fd, ArpPacket **packet, size_t *packet_len) {
|
|
int s;
|
|
struct sockaddr_ll sa;
|
|
socklen_t sa_len;
|
|
ssize_t r;
|
|
|
|
assert(fd >= 0);
|
|
assert(packet);
|
|
assert(packet_len);
|
|
|
|
*packet = NULL;
|
|
|
|
if (ioctl(fd, FIONREAD, &s) < 0) {
|
|
daemon_log(LOG_ERR, "FIONREAD failed: %s", strerror(errno));
|
|
goto fail;
|
|
}
|
|
|
|
if (s <= 0)
|
|
s = 4096;
|
|
|
|
*packet = packet_new(s);
|
|
|
|
sa_len = sizeof(sa);
|
|
if ((r = recvfrom(fd, (*packet)->ether_payload, s, 0, (struct sockaddr*) &sa, &sa_len)) < 0) {
|
|
daemon_log(LOG_ERR, "recvfrom() failed: %s", strerror(errno));
|
|
goto fail;
|
|
}
|
|
|
|
*packet_len = (size_t) r;
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
if (*packet) {
|
|
avahi_free(*packet);
|
|
*packet = NULL;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
static void close_socket(int fd) {
|
|
close(fd);
|
|
}
|
|
|
|
#else /* !__linux__ */
|
|
/* PCAP-based implementation */
|
|
|
|
static pcap_t *__pp;
|
|
static char __pcap_errbuf[PCAP_ERRBUF_SIZE];
|
|
static uint8_t __lladdr[ETHER_ADDRLEN];
|
|
|
|
#ifndef elementsof
|
|
#define elementsof(array) (sizeof(array)/sizeof(array[0]))
|
|
#endif
|
|
|
|
static int __get_ether_addr(int ifindex, u_char *lladdr) {
|
|
int mib[6];
|
|
char *buf;
|
|
struct if_msghdr *ifm;
|
|
char *lim;
|
|
char *next;
|
|
struct sockaddr_dl *sdl;
|
|
size_t len;
|
|
|
|
mib[0] = CTL_NET;
|
|
mib[1] = PF_ROUTE;
|
|
mib[2] = 0;
|
|
mib[3] = 0;
|
|
mib[4] = NET_RT_IFLIST;
|
|
mib[5] = ifindex;
|
|
|
|
if (sysctl(mib, elementsof(mib), NULL, &len, NULL, 0) != 0) {
|
|
daemon_log(LOG_ERR, "sysctl(NET_RT_IFLIST): %s",
|
|
strerror(errno));
|
|
return -1;
|
|
}
|
|
|
|
buf = avahi_malloc(len);
|
|
if (sysctl(mib, elementsof(mib), buf, &len, NULL, 0) != 0) {
|
|
daemon_log(LOG_ERR, "sysctl(NET_RT_IFLIST): %s",
|
|
strerror(errno));
|
|
free(buf);
|
|
return -1;
|
|
}
|
|
|
|
lim = buf + len;
|
|
for (next = buf; next < lim; next += ifm->ifm_msglen) {
|
|
ifm = (struct if_msghdr *)next;
|
|
if (ifm->ifm_type == RTM_IFINFO) {
|
|
sdl = (struct sockaddr_dl *)(ifm + 1);
|
|
memcpy(lladdr, LLADDR(sdl), ETHER_ADDRLEN);
|
|
}
|
|
}
|
|
avahi_free(buf);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define PCAP_TIMEOUT 500 /* 0.5s */
|
|
|
|
static int open_socket(int iface, uint8_t *hw_address) {
|
|
struct bpf_program bpf;
|
|
char *filter;
|
|
char ifname[IFNAMSIZ];
|
|
pcap_t *pp;
|
|
int err;
|
|
int fd;
|
|
|
|
assert(__pp == NULL);
|
|
|
|
if (interface_up(iface) < 0)
|
|
return -1;
|
|
|
|
if (__get_ether_addr(iface, __lladdr) == -1)
|
|
return -1;
|
|
|
|
if (if_indextoname(iface, ifname) == NULL)
|
|
return -1;
|
|
|
|
/*
|
|
* Using a timeout for BPF is fairly portable across BSDs. On most
|
|
* modern versions, using the timeout/nonblock/poll method results in
|
|
* fairly sane behavior, with the timeout only coming into play during
|
|
* the next_ex() call itself (so, for us, that's only when there's
|
|
* data). On older versions, it may result in a PCAP_TIMEOUT busy-wait
|
|
* on some versions, though, as the poll() may terminate at the
|
|
* PCAP_TIMEOUT instead of the poll() timeout.
|
|
*/
|
|
pp = pcap_open_live(ifname, 1500, 0, PCAP_TIMEOUT, __pcap_errbuf);
|
|
if (pp == NULL) {
|
|
return (-1);
|
|
}
|
|
err = pcap_set_datalink(pp, DLT_EN10MB);
|
|
if (err == -1) {
|
|
daemon_log(LOG_ERR, "pcap_set_datalink: %s", pcap_geterr(pp));
|
|
pcap_close(pp);
|
|
return (-1);
|
|
}
|
|
err = pcap_setdirection(pp, PCAP_D_IN);
|
|
if (err == -1) {
|
|
daemon_log(LOG_ERR, "pcap_setdirection: %s", pcap_geterr(pp));
|
|
pcap_close(pp);
|
|
return (-1);
|
|
}
|
|
|
|
fd = pcap_get_selectable_fd(pp);
|
|
if (fd == -1) {
|
|
pcap_close(pp);
|
|
return (-1);
|
|
}
|
|
|
|
/*
|
|
* Using setnonblock is a portability stop-gap. Using the timeout in
|
|
* combination with setnonblock will ensure on most BSDs that the
|
|
* next_ex call returns in a timely fashion.
|
|
*/
|
|
err = pcap_setnonblock(pp, 1, __pcap_errbuf);
|
|
if (err == -1) {
|
|
pcap_close(pp);
|
|
return (-1);
|
|
}
|
|
|
|
filter = avahi_strdup_printf("arp and (ether dst ff:ff:ff:ff:ff:ff or "
|
|
"%02x:%02x:%02x:%02x:%02x:%02x)",
|
|
__lladdr[0], __lladdr[1],
|
|
__lladdr[2], __lladdr[3],
|
|
__lladdr[4], __lladdr[5]);
|
|
DEBUG(daemon_log(LOG_DEBUG, "Using pcap filter '%s'", filter));
|
|
|
|
err = pcap_compile(pp, &bpf, filter, 1, 0);
|
|
avahi_free(filter);
|
|
if (err == -1) {
|
|
daemon_log(LOG_ERR, "pcap_compile: %s", pcap_geterr(pp));
|
|
pcap_close(pp);
|
|
return (-1);
|
|
}
|
|
err = pcap_setfilter(pp, &bpf);
|
|
if (err == -1) {
|
|
daemon_log(LOG_ERR, "pcap_setfilter: %s", pcap_geterr(pp));
|
|
pcap_close(pp);
|
|
return (-1);
|
|
}
|
|
pcap_freecode(&bpf);
|
|
|
|
/* Stash pcap-specific context away. */
|
|
memcpy(hw_address, __lladdr, ETHER_ADDRLEN);
|
|
__pp = pp;
|
|
|
|
return (fd);
|
|
}
|
|
|
|
static void close_socket(int fd AVAHI_GCC_UNUSED) {
|
|
assert(__pp != NULL);
|
|
pcap_close(__pp);
|
|
__pp = NULL;
|
|
}
|
|
|
|
/*
|
|
* We trick avahi into allocating sizeof(packet) + sizeof(ether_header),
|
|
* and prepend the required ethernet header information before sending.
|
|
*/
|
|
static int send_packet(int fd AVAHI_GCC_UNUSED, int iface AVAHI_GCC_UNUSED, ArpPacket *packet, size_t packet_len) {
|
|
struct ether_header *eh;
|
|
|
|
assert(__pp != NULL);
|
|
assert(packet != NULL);
|
|
|
|
eh = (struct ether_header *)packet->ether_header;
|
|
memset(eh->ether_dhost, 0xFF, ETHER_ADDRLEN);
|
|
memcpy(eh->ether_shost, __lladdr, ETHER_ADDRLEN);
|
|
eh->ether_type = htons(0x0806);
|
|
|
|
return (pcap_inject(__pp, (void *)eh, packet_len + sizeof(*eh)));
|
|
}
|
|
|
|
static int recv_packet(int fd AVAHI_GCC_UNUSED, ArpPacket **packet, size_t *packet_len) {
|
|
struct pcap_pkthdr *ph;
|
|
u_char *pd;
|
|
ArpPacket *ap;
|
|
int err;
|
|
int retval;
|
|
|
|
assert(__pp != NULL);
|
|
assert(packet != NULL);
|
|
assert(packet_len != NULL);
|
|
|
|
*packet = NULL;
|
|
*packet_len = 0;
|
|
retval = -1;
|
|
|
|
err = pcap_next_ex(__pp, &ph, (const u_char **)&pd);
|
|
if (err == 1 && ph->caplen <= ph->len) {
|
|
ap = packet_new(ph->caplen);
|
|
memcpy(ap->ether_header, pd, ph->caplen);
|
|
*packet = ap;
|
|
*packet_len = (ph->caplen - sizeof(struct ether_header));
|
|
retval = 0;
|
|
} else if (err >= 0) {
|
|
/*
|
|
* err == 1: Just drop bogus packets (>1500 for an arp packet!?)
|
|
* on the floor.
|
|
*
|
|
* err == 0: We might have had traffic on the pcap fd that
|
|
* didn't match the filter, in which case we'll get 0 packets.
|
|
*/
|
|
retval = 0;
|
|
} else
|
|
daemon_log(LOG_ERR, "pcap_next_ex(%d): %s",
|
|
err, pcap_geterr(__pp));
|
|
|
|
return (retval);
|
|
}
|
|
#endif /* __linux__ */
|
|
|
|
int is_ll_address(uint32_t addr) {
|
|
return
|
|
((ntohl(addr) & IPV4LL_NETMASK) == IPV4LL_NETWORK) &&
|
|
((ntohl(addr) & 0x0000FF00) != 0x0000) &&
|
|
((ntohl(addr) & 0x0000FF00) != 0xFF00);
|
|
}
|
|
|
|
static struct timeval *elapse_time(struct timeval *tv, unsigned msec, unsigned jitter) {
|
|
assert(tv);
|
|
|
|
gettimeofday(tv, NULL);
|
|
|
|
if (msec)
|
|
avahi_timeval_add(tv, (AvahiUsec) msec*1000);
|
|
|
|
if (jitter)
|
|
avahi_timeval_add(tv, (AvahiUsec) (jitter*1000.0*rand()/(RAND_MAX+1.0)));
|
|
|
|
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();
|
|
|
|
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,
|
|
action_script, action_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;
|
|
|
|
pw = NULL;
|
|
gr = NULL;
|
|
|
|
/* 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 privileges"
|
|
#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 privileges"
|
|
#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_INFO, "Successfully dropped root privileges.");
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int loop(int iface, uint32_t addr) {
|
|
enum {
|
|
FD_ARP,
|
|
FD_IFACE,
|
|
FD_SIGNAL,
|
|
FD_MAX
|
|
};
|
|
|
|
int fd = -1, ret = -1;
|
|
struct timeval next_wakeup;
|
|
int next_wakeup_valid = 0;
|
|
char buf[64];
|
|
ArpPacket *in_packet = NULL;
|
|
size_t in_packet_len = 0;
|
|
ArpPacket *out_packet = NULL;
|
|
size_t out_packet_len;
|
|
uint8_t hw_address[ETHER_ADDRLEN];
|
|
struct pollfd pollfds[FD_MAX];
|
|
int iface_fd = -1;
|
|
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 (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 or a reserved address, ignoring.", inet_ntop(AF_INET, &addr, buf, sizeof(buf)));
|
|
addr = 0;
|
|
}
|
|
|
|
if (!addr) {
|
|
int i;
|
|
uint32_t a = 1;
|
|
|
|
for (i = 0; i < ETHER_ADDRLEN; i++)
|
|
a += hw_address[i]*i;
|
|
|
|
a = (a % 0xFE00) + 0x0100;
|
|
|
|
addr = htonl(IPV4LL_NETWORK | (uint32_t) a);
|
|
}
|
|
|
|
assert(is_ll_address(addr));
|
|
|
|
set_state(st, 1, addr);
|
|
|
|
daemon_log(LOG_INFO, "Starting with address %s", inet_ntop(AF_INET, &addr, buf, sizeof(buf)));
|
|
|
|
if (state == STATE_SLEEPING)
|
|
daemon_log(LOG_INFO, "Routable address already assigned, sleeping.");
|
|
|
|
if (!retval_sent && (!wait_for_address || state == STATE_SLEEPING)) {
|
|
daemon_retval_send(0);
|
|
retval_sent = 1;
|
|
}
|
|
|
|
memset(pollfds, 0, sizeof(pollfds));
|
|
pollfds[FD_ARP].fd = fd;
|
|
pollfds[FD_ARP].events = POLLIN;
|
|
pollfds[FD_IFACE].fd = iface_fd;
|
|
pollfds[FD_IFACE].events = POLLIN;
|
|
pollfds[FD_SIGNAL].fd = daemon_signal_fd();
|
|
pollfds[FD_SIGNAL].events = POLLIN;
|
|
|
|
for (;;) {
|
|
int r, timeout;
|
|
AvahiUsec usec;
|
|
|
|
if (state == STATE_START) {
|
|
|
|
/* First, wait a random time */
|
|
set_state(STATE_WAITING_PROBE, 1, addr);
|
|
|
|
elapse_time(&next_wakeup, 0, PROBE_WAIT*1000);
|
|
next_wakeup_valid = 1;
|
|
|
|
} else if ((state == STATE_WAITING_PROBE && event == EVENT_TIMEOUT) ||
|
|
(state == STATE_PROBING && event == EVENT_TIMEOUT && n_iteration < PROBE_NUM-2)) {
|
|
|
|
/* Send a probe */
|
|
out_packet = packet_new_probe(addr, hw_address, &out_packet_len);
|
|
set_state(STATE_PROBING, 0, addr);
|
|
|
|
elapse_time(&next_wakeup, PROBE_MIN*1000, (PROBE_MAX-PROBE_MIN)*1000);
|
|
next_wakeup_valid = 1;
|
|
|
|
} else if (state == STATE_PROBING && event == EVENT_TIMEOUT && n_iteration >= PROBE_NUM-2) {
|
|
|
|
/* Send the last probe */
|
|
out_packet = packet_new_probe(addr, hw_address, &out_packet_len);
|
|
set_state(STATE_WAITING_ANNOUNCE, 1, addr);
|
|
|
|
elapse_time(&next_wakeup, ANNOUNCE_WAIT*1000, 0);
|
|
next_wakeup_valid = 1;
|
|
|
|
} else if ((state == STATE_WAITING_ANNOUNCE && event == EVENT_TIMEOUT) ||
|
|
(state == STATE_ANNOUNCING && event == EVENT_TIMEOUT && n_iteration < ANNOUNCE_NUM-1)) {
|
|
|
|
/* Send announcement packet */
|
|
out_packet = packet_new_announcement(addr, hw_address, &out_packet_len);
|
|
set_state(STATE_ANNOUNCING, 0, addr);
|
|
|
|
elapse_time(&next_wakeup, ANNOUNCE_INTERVAL*1000, 0);
|
|
next_wakeup_valid = 1;
|
|
|
|
if (n_iteration == 0) {
|
|
if (do_callout(dispatcher, CALLOUT_BIND, iface, addr) < 0)
|
|
goto fail;
|
|
|
|
n_conflict = 0;
|
|
}
|
|
|
|
} else if ((state == STATE_ANNOUNCING && event == EVENT_TIMEOUT && n_iteration >= ANNOUNCE_NUM-1)) {
|
|
|
|
daemon_log(LOG_INFO, "Successfully claimed IP address %s", inet_ntop(AF_INET, &addr, buf, sizeof(buf)));
|
|
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;
|
|
|
|
assert(in_packet);
|
|
|
|
if (packet_parse(in_packet, in_packet_len, &info) < 0)
|
|
daemon_log(LOG_WARNING, "Failed to parse incoming ARP packet.");
|
|
else {
|
|
int conflict = 0;
|
|
|
|
if (info.sender_ip_address == addr) {
|
|
|
|
if (memcmp(hw_address, info.sender_hw_address, ETHER_ADDRLEN)) {
|
|
/* Normal conflict */
|
|
conflict = 1;
|
|
daemon_log(LOG_INFO, "Received conflicting normal ARP packet.");
|
|
} else
|
|
daemon_log(LOG_DEBUG, "Received ARP packet back on source interface. Ignoring.");
|
|
|
|
} else if (state == STATE_WAITING_PROBE || state == STATE_PROBING || state == STATE_WAITING_ANNOUNCE) {
|
|
/* Probe conflict */
|
|
conflict = info.target_ip_address == addr && memcmp(hw_address, info.sender_hw_address, ETHER_ADDRLEN);
|
|
|
|
if (conflict)
|
|
daemon_log(LOG_INFO, "Received conflicting probe ARP packet.");
|
|
}
|
|
|
|
if (conflict) {
|
|
|
|
if (state == STATE_RUNNING || state == STATE_ANNOUNCING)
|
|
if (do_callout(dispatcher, CALLOUT_CONFLICT, iface, addr) < 0)
|
|
goto fail;
|
|
|
|
/* Pick a new address */
|
|
addr = pick_addr(addr);
|
|
|
|
daemon_log(LOG_INFO, "Trying address %s", inet_ntop(AF_INET, &addr, buf, sizeof(buf)));
|
|
|
|
n_conflict++;
|
|
|
|
set_state(STATE_WAITING_PROBE, 1, addr);
|
|
|
|
if (n_conflict >= MAX_CONFLICTS) {
|
|
daemon_log(LOG_WARNING, "Got too many conflicts, rate limiting new probes.");
|
|
elapse_time(&next_wakeup, RATE_LIMIT_INTERVAL*1000, PROBE_WAIT*1000);
|
|
} else
|
|
elapse_time(&next_wakeup, 0, PROBE_WAIT*1000);
|
|
|
|
next_wakeup_valid = 1;
|
|
} else
|
|
DEBUG(daemon_log(LOG_DEBUG, "Ignoring irrelevant ARP packet."));
|
|
}
|
|
|
|
} else if (event == EVENT_ROUTABLE_ADDR_CONFIGURED && !force_bind) {
|
|
|
|
daemon_log(LOG_INFO, "A routable address has been configured.");
|
|
|
|
if (state == STATE_RUNNING || state == STATE_ANNOUNCING)
|
|
if (do_callout(dispatcher, CALLOUT_UNBIND, iface, addr) < 0)
|
|
goto fail;
|
|
|
|
if (!retval_sent) {
|
|
daemon_retval_send(0);
|
|
retval_sent = 1;
|
|
}
|
|
|
|
set_state(STATE_SLEEPING, 1, addr);
|
|
next_wakeup_valid = 0;
|
|
|
|
} 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.");
|
|
|
|
set_state(STATE_WAITING_PROBE, 1, addr);
|
|
|
|
elapse_time(&next_wakeup, 0, PROBE_WAIT*1000);
|
|
next_wakeup_valid = 1;
|
|
|
|
} else if (event == EVENT_REFRESH_REQUEST && state == STATE_RUNNING) {
|
|
|
|
/* The user requested a reannouncing of the address by a SIGHUP */
|
|
daemon_log(LOG_INFO, "Reannouncing address.");
|
|
|
|
/* Send announcement packet */
|
|
out_packet = packet_new_announcement(addr, hw_address, &out_packet_len);
|
|
set_state(STATE_ANNOUNCING, 1, addr);
|
|
|
|
elapse_time(&next_wakeup, ANNOUNCE_INTERVAL*1000, 0);
|
|
next_wakeup_valid = 1;
|
|
}
|
|
|
|
if (out_packet) {
|
|
DEBUG(daemon_log(LOG_DEBUG, "sending..."));
|
|
|
|
if (send_packet(fd, iface, out_packet, out_packet_len) < 0)
|
|
goto fail;
|
|
|
|
avahi_free(out_packet);
|
|
out_packet = NULL;
|
|
}
|
|
|
|
if (in_packet) {
|
|
avahi_free(in_packet);
|
|
in_packet = NULL;
|
|
}
|
|
|
|
event = EVENT_NULL;
|
|
timeout = -1;
|
|
|
|
if (next_wakeup_valid) {
|
|
usec = avahi_age(&next_wakeup);
|
|
timeout = usec < 0 ? (int) (-usec/1000) : 0;
|
|
}
|
|
|
|
DEBUG(daemon_log(LOG_DEBUG, "sleeping %ims", timeout));
|
|
|
|
while ((r = poll(pollfds, FD_MAX, timeout)) < 0 && errno == EINTR)
|
|
;
|
|
|
|
if (r < 0) {
|
|
daemon_log(LOG_ERR, "poll() failed: %s", strerror(r));
|
|
goto fail;
|
|
} else if (r == 0) {
|
|
event = EVENT_TIMEOUT;
|
|
next_wakeup_valid = 0;
|
|
} else {
|
|
|
|
|
|
if (pollfds[FD_ARP].revents) {
|
|
|
|
if (pollfds[FD_ARP].revents == POLLERR) {
|
|
/* The interface is probably down, let's recreate our socket */
|
|
|
|
close_socket(fd);
|
|
|
|
if ((fd = open_socket(iface, hw_address)) < 0)
|
|
goto fail;
|
|
|
|
pollfds[FD_ARP].fd = fd;
|
|
|
|
} else {
|
|
|
|
assert(pollfds[FD_ARP].revents == POLLIN);
|
|
|
|
if (recv_packet(fd, &in_packet, &in_packet_len) < 0)
|
|
goto fail;
|
|
|
|
if (in_packet)
|
|
event = EVENT_PACKET;
|
|
}
|
|
}
|
|
|
|
if (event == EVENT_NULL &&
|
|
pollfds[FD_IFACE].revents) {
|
|
|
|
assert(pollfds[FD_IFACE].revents == POLLIN);
|
|
|
|
if (iface_process(&event) < 0)
|
|
goto fail;
|
|
}
|
|
|
|
if (event == EVENT_NULL &&
|
|
pollfds[FD_SIGNAL].revents) {
|
|
|
|
int sig;
|
|
assert(pollfds[FD_SIGNAL].revents == POLLIN);
|
|
|
|
if ((sig = daemon_signal_next()) <= 0) {
|
|
daemon_log(LOG_ERR, "daemon_signal_next() failed");
|
|
goto fail;
|
|
}
|
|
|
|
switch(sig) {
|
|
case SIGINT:
|
|
case SIGTERM:
|
|
daemon_log(LOG_INFO, "Got %s, quitting.", sig == SIGINT ? "SIGINT" : "SIGTERM");
|
|
ret = 0;
|
|
goto fail;
|
|
|
|
case SIGCHLD:
|
|
waitpid(-1, NULL, WNOHANG);
|
|
break;
|
|
|
|
case SIGHUP:
|
|
event = EVENT_REFRESH_REQUEST;
|
|
break;
|
|
}
|
|
|
|
}
|
|
}
|
|
}
|
|
|
|
ret = 0;
|
|
|
|
fail:
|
|
|
|
if (state == STATE_RUNNING || state == STATE_ANNOUNCING)
|
|
do_callout(dispatcher, CALLOUT_STOP, iface, addr);
|
|
|
|
avahi_free(out_packet);
|
|
avahi_free(in_packet);
|
|
|
|
if (fd >= 0)
|
|
close_socket(fd);
|
|
|
|
if (iface_fd >= 0)
|
|
iface_done();
|
|
|
|
if (daemonize && !retval_sent)
|
|
daemon_retval_send(ret);
|
|
|
|
if (dispatcher)
|
|
fclose(dispatcher);
|
|
|
|
if (address_fn)
|
|
avahi_free(address_fn);
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
static void help(FILE *f, const char *a0) {
|
|
fprintf(f,
|
|
"%s [options] INTERFACE\n"
|
|
" -h --help Show this help\n"
|
|
" -D --daemonize Daemonize after startup\n"
|
|
" -s --syslog Write log messages to syslog(3) instead of STDERR\n"
|
|
" -k --kill Kill a running daemon\n"
|
|
" -r --refresh Request a running daemon refresh its 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\n"
|
|
" 169.254.0.0/16\n"
|
|
" -t --script=script Action script to run (defaults to\n"
|
|
" "AVAHI_IPCONF_SCRIPT")\n"
|
|
" -w --wait Wait until an address has been acquired before\n"
|
|
" daemonizing\n"
|
|
" --force-bind Assign an IPv4LL address even if a 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);
|
|
}
|
|
|
|
static int parse_command_line(int argc, char *argv[]) {
|
|
int c;
|
|
|
|
enum {
|
|
OPTION_NO_PROC_TITLE = 256,
|
|
OPTION_FORCE_BIND,
|
|
OPTION_DEBUG,
|
|
OPTION_NO_DROP_ROOT,
|
|
#ifdef HAVE_CHROOT
|
|
OPTION_NO_CHROOT
|
|
#endif
|
|
};
|
|
|
|
static const struct option long_options[] = {
|
|
{ "help", no_argument, NULL, 'h' },
|
|
{ "daemonize", no_argument, NULL, 'D' },
|
|
{ "syslog", no_argument, NULL, 's' },
|
|
{ "kill", no_argument, NULL, 'k' },
|
|
{ "refresh", no_argument, NULL, 'r' },
|
|
{ "check", no_argument, NULL, 'c' },
|
|
{ "version", no_argument, NULL, 'V' },
|
|
{ "start", required_argument, NULL, 'S' },
|
|
{ "script", required_argument, NULL, 't' },
|
|
{ "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 }
|
|
};
|
|
|
|
while ((c = getopt_long(argc, argv, "hDskrcVS:t:w", long_options, NULL)) >= 0) {
|
|
|
|
switch(c) {
|
|
case 's':
|
|
use_syslog = 1;
|
|
break;
|
|
case 'h':
|
|
command = DAEMON_HELP;
|
|
break;
|
|
case 'D':
|
|
daemonize = 1;
|
|
break;
|
|
case 'k':
|
|
command = DAEMON_KILL;
|
|
break;
|
|
case 'V':
|
|
command = DAEMON_VERSION;
|
|
break;
|
|
case 'r':
|
|
command = DAEMON_REFRESH;
|
|
break;
|
|
case 'c':
|
|
command = DAEMON_CHECK;
|
|
break;
|
|
case 'S':
|
|
|
|
if ((start_address = inet_addr(optarg)) == (uint32_t) -1) {
|
|
fprintf(stderr, "Failed to parse IP address '%s'.", optarg);
|
|
return -1;
|
|
}
|
|
break;
|
|
case 't':
|
|
avahi_free(action_script);
|
|
action_script = avahi_strdup(optarg);
|
|
break;
|
|
case 'w':
|
|
wait_for_address = 1;
|
|
break;
|
|
|
|
case OPTION_NO_PROC_TITLE:
|
|
modify_proc_title = 0;
|
|
break;
|
|
|
|
case OPTION_DEBUG:
|
|
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:
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
if (command == DAEMON_RUN ||
|
|
command == DAEMON_KILL ||
|
|
command == DAEMON_REFRESH ||
|
|
command == DAEMON_CHECK) {
|
|
|
|
if (optind >= argc) {
|
|
fprintf(stderr, "Missing interface name.\n");
|
|
return -1;
|
|
}
|
|
|
|
interface_name = avahi_strdup(argv[optind++]);
|
|
}
|
|
|
|
if (optind != argc) {
|
|
fprintf(stderr, "Too many arguments\n");
|
|
return -1;
|
|
}
|
|
|
|
if (!action_script)
|
|
action_script = avahi_strdup(AVAHI_IPCONF_SCRIPT);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const char* pid_file_proc(void) {
|
|
return pid_file_name;
|
|
}
|
|
|
|
int main(int argc, char*argv[]) {
|
|
int r = 1;
|
|
char *log_ident = NULL;
|
|
|
|
signal(SIGPIPE, SIG_IGN);
|
|
|
|
if ((argv0 = strrchr(argv[0], '/')))
|
|
argv0 = avahi_strdup(argv0 + 1);
|
|
else
|
|
argv0 = avahi_strdup(argv[0]);
|
|
|
|
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) {
|
|
pid_t pid;
|
|
int ifindex;
|
|
|
|
init_rand_seed();
|
|
|
|
if ((ifindex = if_nametoindex(interface_name)) <= 0) {
|
|
daemon_log(LOG_ERR, "Failed to get index for interface name '%s': %s", interface_name, strerror(errno));
|
|
goto finish;
|
|
}
|
|
|
|
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 receive return value from daemon process.");
|
|
goto finish;
|
|
}
|
|
|
|
r = ret;
|
|
goto finish;
|
|
}
|
|
|
|
/* Child */
|
|
}
|
|
|
|
if (use_syslog || daemonize)
|
|
daemon_log_use = DAEMON_LOG_SYSLOG;
|
|
|
|
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 = 1;
|
|
|
|
avahi_set_proc_title(argv0, "%s: [%s] starting up", argv0, interface_name);
|
|
|
|
if (loop(ifindex, start_address) < 0)
|
|
goto finish;
|
|
|
|
r = 0;
|
|
} else if (command == DAEMON_HELP) {
|
|
help(stdout, argv0);
|
|
|
|
r = 0;
|
|
} else if (command == DAEMON_VERSION) {
|
|
printf("%s "PACKAGE_VERSION"\n", argv0);
|
|
|
|
r = 0;
|
|
} 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;
|
|
}
|
|
|
|
r = 0;
|
|
} else if (command == DAEMON_REFRESH) {
|
|
if (daemon_pid_file_kill(SIGHUP) < 0) {
|
|
daemon_log(LOG_WARNING, "Failed to kill daemon: %s", strerror(errno));
|
|
goto finish;
|
|
}
|
|
|
|
r = 0;
|
|
} else if (command == DAEMON_CHECK)
|
|
r = (daemon_pid_file_is_running() >= 0) ? 0 : 1;
|
|
|
|
|
|
finish:
|
|
|
|
if (daemonize)
|
|
daemon_retval_done();
|
|
|
|
if (wrote_pid_file)
|
|
daemon_pid_file_remove();
|
|
|
|
avahi_free(log_ident);
|
|
avahi_free(pid_file_name);
|
|
avahi_free(argv0);
|
|
avahi_free(interface_name);
|
|
avahi_free(action_script);
|
|
|
|
return r;
|
|
}
|