| /*** |
| This file is part of avahi. |
| |
| avahi is free software; you can redistribute it and/or modify it |
| under the terms of the GNU Lesser General Public License as |
| published by the Free Software Foundation; either version 2.1 of the |
| License, or (at your option) any later version. |
| |
| avahi is distributed in the hope that it will be useful, but WITHOUT |
| ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General |
| Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with avahi; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 |
| USA. |
| ***/ |
| |
| #ifdef HAVE_CONFIG_H |
| #include <config.h> |
| #endif |
| |
| #include <sys/param.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <sys/ioctl.h> |
| #include <sys/socket.h> |
| #include <sys/wait.h> |
| #ifdef __FreeBSD__ |
| #include <sys/sysctl.h> |
| #endif |
| |
| #ifdef __linux__ |
| #include <netpacket/packet.h> |
| #endif |
| #include <net/ethernet.h> |
| #include <net/if.h> |
| #ifdef __FreeBSD__ |
| #include <net/if_dl.h> |
| #include <net/route.h> |
| #endif |
| #include <arpa/inet.h> |
| |
| #include <assert.h> |
| #include <errno.h> |
| #include <inttypes.h> |
| #include <fcntl.h> |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <signal.h> |
| #include <string.h> |
| #include <time.h> |
| #include <getopt.h> |
| |
| #include <grp.h> |
| #include <poll.h> |
| #include <pwd.h> |
| #include <unistd.h> |
| |
| #ifndef __linux__ |
| #include <pcap.h> |
| |
| /* Old versions of PCAP defined it as D_IN */ |
| #ifndef PCAP_D_IN |
| #define PCAP_D_IN D_IN |
| #endif |
| |
| #endif |
| |
| #include <avahi-common/malloc.h> |
| #include <avahi-common/timeval.h> |
| #include <avahi-daemon/setproctitle.h> |
| |
| #include <libdaemon/dfork.h> |
| #include <libdaemon/dsignal.h> |
| #include <libdaemon/dlog.h> |
| #include <libdaemon/dpid.h> |
| #include <libdaemon/dexec.h> |
| |
| #include "main.h" |
| #include "iface.h" |
| |
| /* An implementation of RFC 3927 */ |
| |
| /* Constants from the RFC */ |
| #define PROBE_WAIT 1 |
| #define PROBE_NUM 3 |
| #define PROBE_MIN 1 |
| #define PROBE_MAX 2 |
| #define ANNOUNCE_WAIT 2 |
| #define ANNOUNCE_NUM 2 |
| #define ANNOUNCE_INTERVAL 2 |
| #define MAX_CONFLICTS 10 |
| #define RATE_LIMIT_INTERVAL 60 |
| #define DEFEND_INTERVAL 10 |
| |
| #define IPV4LL_NETWORK 0xA9FE0000L |
| #define IPV4LL_NETMASK 0xFFFF0000L |
| #define IPV4LL_HOSTMASK 0x0000FFFFL |
| #define IPV4LL_BROADCAST 0xA9FEFFFFL |
| |
| #define ETHER_ADDRLEN 6 |
| #define ETHER_HDR_SIZE (2+2*ETHER_ADDRLEN) |
| #define ARP_PACKET_SIZE (8+4+4+2*ETHER_ADDRLEN) |
| |
| typedef enum ArpOperation { |
| ARP_REQUEST = 1, |
| ARP_RESPONSE = 2 |
| } ArpOperation; |
| |
| typedef struct ArpPacketInfo { |
| ArpOperation operation; |
| |
| uint32_t sender_ip_address, target_ip_address; |
| uint8_t sender_hw_address[ETHER_ADDRLEN], target_hw_address[ETHER_ADDRLEN]; |
| } ArpPacketInfo; |
| |
| typedef struct ArpPacket { |
| uint8_t *ether_header; |
| uint8_t *ether_payload; |
| } ArpPacket; |
| |
| static State state = STATE_START; |
| static int n_iteration = 0; |
| static int n_conflict = 0; |
| |
| static char *interface_name = NULL; |
| static char *pid_file_name = NULL; |
| static uint32_t start_address = 0; |
| static char *argv0 = NULL; |
| static int daemonize = 0; |
| 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 char *action_script = NULL; |
| |
| static enum { |
| DAEMON_RUN, |
| DAEMON_KILL, |
| DAEMON_REFRESH, |
| DAEMON_VERSION, |
| DAEMON_HELP, |
| DAEMON_CHECK |
| } command = DAEMON_RUN; |
| |
| typedef enum CalloutEvent { |
| CALLOUT_BIND, |
| CALLOUT_CONFLICT, |
| CALLOUT_UNBIND, |
| CALLOUT_STOP, |
| 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 { \ |
| if (debug) { \ |
| x; \ |
| } \ |
| } while (0) |
| |
| static void init_rand_seed(void) { |
| int fd; |
| unsigned seed = 0; |
| |
| /* Try to initialize seed from /dev/urandom, to make it a little |
| * less predictable, and to make sure that multiple machines |
| * booted at the same time choose different random seeds. */ |
| if ((fd = open(RANDOM_DEVICE, O_RDONLY)) >= 0) { |
| read(fd, &seed, sizeof(seed)); |
| close(fd); |
| } |
| |
| /* If the initialization failed by some reason, we add the time to the seed */ |
| seed ^= (unsigned) time(NULL); |
| |
| srand(seed); |
| } |
| |
| static uint32_t pick_addr(uint32_t old_addr) { |
| uint32_t addr; |
| |
| do { |
| unsigned r = (unsigned) rand(); |
| |
| /* Reduce to 16 bits */ |
| while (r > 0xFFFF) |
| r = (r >> 16) ^ (r & 0xFFFF); |
| |
| addr = htonl(IPV4LL_NETWORK | (uint32_t) r); |
| |
| } 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]; |
| mode_t u; |
| |
| assert(fn); |
| |
| u = umask(0033); |
| if (!(f = fopen(fn, "w"))) { |
| daemon_log(LOG_ERR, "fopen() failed: %s", strerror(errno)); |
| goto fail; |
| } |
| umask(u); |
| |
| fprintf(f, "%s\n", inet_ntop(AF_INET, &addr, buf, sizeof (buf))); |
| fclose(f); |
| |
| return 0; |
| |
| fail: |
| if (f) |
| fclose(f); |
| |
| umask(u); |
| |
| return -1; |
| } |
| |
| /* |
| * Allocate a buffer with two pointers in front, one of which is |
| * guaranteed to point ETHER_HDR_SIZE bytes into it. |
| */ |
| static ArpPacket* packet_new(size_t packet_len) { |
| ArpPacket *p; |
| uint8_t *b; |
| |
| assert(packet_len > 0); |
| |
| #ifdef __linux__ |
| b = avahi_new0(uint8_t, sizeof(struct ArpPacket) + packet_len); |
| p = (ArpPacket*) b; |
| p->ether_header = NULL; |
| p->ether_payload = b + sizeof(struct ArpPacket); |
| |
| #else |
| b = avahi_new0(uint8_t, sizeof(struct ArpPacket) + ETHER_HDR_SIZE + packet_len); |
| p = (ArpPacket*) b; |
| p->ether_header = b + sizeof(struct ArpPacket); |
| p->ether_payload = b + sizeof(struct ArpPacket) + ETHER_HDR_SIZE; |
| #endif |
| |
| return p; |
| } |
| |
| static ArpPacket* packet_new_with_info(const ArpPacketInfo *info, size_t *packet_len) { |
| ArpPacket *p = NULL; |
| uint8_t *r; |
| |
| assert(info); |
| assert(info->operation == ARP_REQUEST || info->operation == ARP_RESPONSE); |
| assert(packet_len != NULL); |
| |
| *packet_len = ARP_PACKET_SIZE; |
| p = packet_new(*packet_len); |
| r = p->ether_payload; |
| |
| r[1] = 1; /* HTYPE */ |
| r[2] = 8; /* PTYPE */ |
| r[4] = ETHER_ADDRLEN; /* HLEN */ |
| r[5] = 4; /* PLEN */ |
| r[7] = (uint8_t) info->operation; |
| |
| memcpy(r+8, info->sender_hw_address, ETHER_ADDRLEN); |
| memcpy(r+14, &info->sender_ip_address, 4); |
| memcpy(r+18, info->target_hw_address, ETHER_ADDRLEN); |
| memcpy(r+24, &info->target_ip_address, 4); |
| |
| return p; |
| } |
| |
| static ArpPacket *packet_new_probe(uint32_t ip_address, const uint8_t*hw_address, size_t *packet_len) { |
| ArpPacketInfo info; |
| |
| memset(&info, 0, sizeof(info)); |
| info.operation = ARP_REQUEST; |
| memcpy(info.sender_hw_address, hw_address, ETHER_ADDRLEN); |
| info.target_ip_address = ip_address; |
| |
| return packet_new_with_info(&info, packet_len); |
| } |
| |
| static ArpPacket *packet_new_announcement(uint32_t ip_address, const uint8_t* hw_address, size_t *packet_len) { |
| ArpPacketInfo info; |
| |
| memset(&info, 0, sizeof(info)); |
| info.operation = ARP_REQUEST; |
| memcpy(info.sender_hw_address, hw_address, ETHER_ADDRLEN); |
| info.target_ip_address = ip_address; |
| info.sender_ip_address = ip_address; |
| |
| return packet_new_with_info(&info, packet_len); |
| } |
| |
| static int packet_parse(const ArpPacket *packet, size_t packet_len, ArpPacketInfo *info) { |
| const uint8_t *p; |
| |
| assert(packet); |
| p = (uint8_t *)packet->ether_payload; |
| assert(p); |
| |
| if (packet_len < ARP_PACKET_SIZE) |
| return -1; |
| |
| /* Check HTYPE and PTYPE */ |
| if (p[0] != 0 || p[1] != 1 || p[2] != 8 || p[3] != 0) |
| return -1; |
| |
| /* Check HLEN, PLEN, OPERATION */ |
| if (p[4] != ETHER_ADDRLEN || p[5] != 4 || p[6] != 0 || (p[7] != 1 && p[7] != 2)) |
| return -1; |
| |
| info->operation = p[7]; |
| memcpy(info->sender_hw_address, p+8, ETHER_ADDRLEN); |
| memcpy(&info->sender_ip_address, p+14, 4); |
| memcpy(info->target_hw_address, p+18, ETHER_ADDRLEN); |
| memcpy(&info->target_ip_address, p+24, 4); |
| |
| return 0; |
| } |
| |
| static void set_state(State st, int reset_counter, uint32_t address) { |
| static const char* const state_table[] = { |
| [STATE_START] = "START", |
| [STATE_WAITING_PROBE] = "WAITING_PROBE", |
| [STATE_PROBING] = "PROBING", |
| [STATE_WAITING_ANNOUNCE] = "WAITING_ANNOUNCE", |
| [STATE_ANNOUNCING] = "ANNOUNCING", |
| [STATE_RUNNING] = "RUNNING", |
| [STATE_SLEEPING] = "SLEEPING" |
| }; |
| char buf[64]; |
| |
| assert(st < STATE_MAX); |
| |
| if (st == state && !reset_counter) { |
| n_iteration++; |
| DEBUG(daemon_log(LOG_DEBUG, "State iteration %s-%i", state_table[state], n_iteration)); |
| } else { |
| DEBUG(daemon_log(LOG_DEBUG, "State transition %s-%i -> %s-0", state_table[state], n_iteration, state_table[st])); |
| state = st; |
| n_iteration = 0; |
| } |
| |
| 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) { |
| 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; |
| } |
