X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=avahi-autoipd%2Fmain.c;h=a1bddb2542ecff976e09260d04de93d3cd6d75ed;hb=7a5b2f69af7d36d6cd4153142f125fa011784e03;hp=4c3b0ebe5adeb7dd1c1da8026ce3a564a651eb16;hpb=9ce608107192e885eb8de93290f7faf0bf9176a2;p=catta diff --git a/avahi-autoipd/main.c b/avahi-autoipd/main.c index 4c3b0eb..a1bddb2 100644 --- a/avahi-autoipd/main.c +++ b/avahi-autoipd/main.c @@ -1,54 +1,75 @@ -/* $Id$ */ - /*** - This file is part of avahi. - - avahi is free software; you can redistribute it and/or modify it - under the terms of the GNU Lesser General Public License as - published by the Free Software Foundation; either version 2.1 of the - License, or (at your option) any later version. - - avahi is distributed in the hope that it will be useful, but WITHOUT - ANY WARRANTY; without even the implied warranty of MERCHANTABILITY - or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General - Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with avahi; if not, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 - USA. + This file is part of avahi. + + avahi is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + avahi is distributed in the hope that it will be useful, but WITHOUT + ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General + Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with avahi; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 + USA. ***/ #ifdef HAVE_CONFIG_H #include #endif -#include -#include +#include +#include +#include +#include #include +#include +#ifdef __FreeBSD__ +#include +#endif + +#ifdef __linux__ #include +#endif #include -#include -#include +#include +#ifdef __FreeBSD__ +#include +#include +#endif +#include + #include #include -#include #include -#include -#include -#include -#include -#include +#include +#include #include -#include #include -#include -#include +#include +#include +#include + #include +#include +#include +#include + +#ifndef __linux__ +#include + +/* Old versions of PCAP defined it as D_IN */ +#ifndef PCAP_D_IN +#define PCAP_D_IN D_IN +#endif + +#endif #include #include - #include #include @@ -60,10 +81,6 @@ #include "main.h" #include "iface.h" -#ifndef __linux__ -#error "avahi-autoipd is only available on Linux for now" -#endif - /* An implementation of RFC 3927 */ /* Constants from the RFC */ @@ -81,8 +98,10 @@ #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 { @@ -97,6 +116,11 @@ typedef struct ArpPacketInfo { 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; @@ -116,6 +140,7 @@ 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, @@ -149,11 +174,12 @@ typedef struct CalloutEventInfo { #define RANDOM_DEVICE "/dev/urandom" -#define DEBUG(x) do {\ -if (debug) { \ - x; \ -} \ -} while (0) +#define DEBUG(x) \ + do { \ + if (debug) { \ + x; \ + } \ + } while (0) static void init_rand_seed(void) { int fd; @@ -182,24 +208,115 @@ static uint32_t pick_addr(uint32_t old_addr) { /* Reduce to 16 bits */ while (r > 0xFFFF) r = (r >> 16) ^ (r & 0xFFFF); - + addr = htonl(IPV4LL_NETWORK | (uint32_t) r); - } while (addr == old_addr); + } while (addr == old_addr || !is_ll_address(addr)); return addr; } -static void* packet_new(const ArpPacketInfo *info, size_t *packet_len) { +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(packet_len); assert(info->operation == ARP_REQUEST || info->operation == ARP_RESPONSE); + assert(packet_len != NULL); *packet_len = ARP_PACKET_SIZE; - r = avahi_new0(uint8_t, *packet_len); - + p = packet_new(*packet_len); + r = p->ether_payload; + r[1] = 1; /* HTYPE */ r[2] = 8; /* PTYPE */ r[4] = ETHER_ADDRLEN; /* HLEN */ @@ -211,21 +328,21 @@ static void* packet_new(const ArpPacketInfo *info, size_t *packet_len) { memcpy(r+18, info->target_hw_address, ETHER_ADDRLEN); memcpy(r+24, &info->target_ip_address, 4); - return r; + return p; } -static void *packet_new_probe(uint32_t ip_address, const uint8_t*hw_address, size_t *packet_len) { +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(&info, packet_len); + return packet_new_with_info(&info, packet_len); } -static void *packet_new_announcement(uint32_t ip_address, const uint8_t* hw_address, size_t *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)); @@ -234,13 +351,15 @@ static void *packet_new_announcement(uint32_t ip_address, const uint8_t* hw_addr info.target_ip_address = ip_address; info.sender_ip_address = ip_address; - return packet_new(&info, packet_len); + return packet_new_with_info(&info, packet_len); } -static int packet_parse(const void *data, size_t packet_len, ArpPacketInfo *info) { - const uint8_t *p = data; - - assert(data); +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; @@ -252,7 +371,7 @@ static int packet_parse(const void *data, size_t packet_len, ArpPacketInfo *info /* 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); @@ -267,13 +386,13 @@ static void set_state(State st, int reset_counter, uint32_t address) { [STATE_START] = "START", [STATE_WAITING_PROBE] = "WAITING_PROBE", [STATE_PROBING] = "PROBING", - [STATE_WAITING_ANNOUNCE] = "WAITING_ANNOUNCE", + [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) { @@ -285,7 +404,7 @@ static void set_state(State st, int reset_counter, uint32_t address) { n_iteration = 0; } - if (state == STATE_SLEEPING) + 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))); @@ -309,7 +428,7 @@ static int interface_up(int iface) { 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; @@ -325,14 +444,18 @@ static int interface_up(int iface) { 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; @@ -340,7 +463,7 @@ static int open_socket(int iface, uint8_t *hw_address) { 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; @@ -350,18 +473,18 @@ static int open_socket(int iface, uint8_t *hw_address) { 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; @@ -370,7 +493,7 @@ static int open_socket(int iface, uint8_t *hw_address) { memcpy(hw_address, sa.sll_addr, ETHER_ADDRLEN); return fd; - + fail: if (fd >= 0) close(fd); @@ -378,9 +501,9 @@ fail: return -1; } -static int send_packet(int fd, int iface, void *packet, size_t packet_len) { +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); @@ -392,7 +515,7 @@ static int send_packet(int fd, int iface, void *packet, size_t packet_len) { sa.sll_halen = ETHER_ADDRLEN; memset(sa.sll_addr, 0xFF, ETHER_ADDRLEN); - if (sendto(fd, packet, packet_len, 0, (struct sockaddr*) &sa, sizeof(sa)) < 0) { + 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; } @@ -400,12 +523,12 @@ static int send_packet(int fd, int iface, void *packet, size_t packet_len) { return 0; } -static int recv_packet(int fd, void **packet, size_t *packet_len) { +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); @@ -420,18 +543,18 @@ static int recv_packet(int fd, void **packet, size_t *packet_len) { if (s <= 0) s = 4096; - *packet = avahi_new(uint8_t, s); + *packet = packet_new(s); sa_len = sizeof(sa); - if ((r = recvfrom(fd, *packet, s, 0, (struct sockaddr*) &sa, &sa_len)) < 0) { + 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); @@ -440,9 +563,226 @@ fail: 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; + 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) { @@ -455,7 +795,7 @@ static struct timeval *elapse_time(struct timeval *tv, unsigned msec, unsigned j if (jitter) avahi_timeval_add(tv, (AvahiUsec) (jitter*1000.0*rand()/(RAND_MAX+1.0))); - + return tv; } @@ -472,7 +812,7 @@ static FILE* fork_dispatcher(void) { if ((pid = fork()) < 0) goto fail; else if (pid == 0) { - FILE *f = NULL; + FILE *f = NULL; int r = 1; /* Please note that the signal pipe is not closed at this @@ -480,8 +820,6 @@ static FILE* fork_dispatcher(void) { * process. */ daemon_retval_done(); - - setsid(); avahi_set_proc_title(argv0, "%s: [%s] callout dispatcher", argv0, interface_name); @@ -491,7 +829,7 @@ static FILE* fork_dispatcher(void) { daemon_log(LOG_ERR, "fdopen() failed: %s", strerror(errno)); goto dispatcher_fail; } - + for (;;) { CalloutEventInfo info; char name[IFNAMSIZ], buf[64]; @@ -511,13 +849,13 @@ static FILE* fork_dispatcher(void) { daemon_log(LOG_ERR, "if_indextoname() failed: %s", strerror(errno)); continue; } - + if (daemon_exec("/", &k, - AVAHI_IPCONF_SCRIPT, AVAHI_IPCONF_SCRIPT, + 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; } @@ -536,11 +874,11 @@ static FILE* fork_dispatcher(void) { #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); } @@ -553,7 +891,7 @@ static FILE* fork_dispatcher(void) { daemon_log(LOG_ERR, "fdopen() failed: %s", strerror(errno)); goto fail; } - + return ret; fail: @@ -582,7 +920,7 @@ static int do_callout(FILE *f, CalloutEvent event, int iface, uint32_t addr) { daemon_log(LOG_ERR, "Failed to write callout event: %s", strerror(errno)); return -1; } - + return 0; } @@ -594,20 +932,23 @@ static int drop_privs(void) { 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); } @@ -615,24 +956,24 @@ static int drop_privs(void) { 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; @@ -654,7 +995,7 @@ static int drop_privs(void) { * the pid file anymore, the helper process will do that for us. */ wrote_pid_file = 0; } - + #endif if (!no_drop_root) { @@ -663,7 +1004,7 @@ static int drop_privs(void) { 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) @@ -672,14 +1013,14 @@ static int drop_privs(void) { #elif defined(HAVE_SETREGID) r = setregid(gr->gr_gid, gr->gr_gid); #else -#error "No API to drop priviliges" +#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) @@ -688,9 +1029,9 @@ static int drop_privs(void) { #elif defined(HAVE_SETREUID) r = setreuid(pw->pw_uid, pw->pw_uid); #else -#error "No API to drop priviliges" +#error "No API to drop privileges" #endif - + if (r < 0) { daemon_log(LOG_ERR, "Failed to change UID: %s", strerror(errno)); return -1; @@ -699,10 +1040,10 @@ static int drop_privs(void) { set_env("USER", pw->pw_name); set_env("LOGNAME", pw->pw_name); set_env("HOME", pw->pw_dir); - - daemon_log(LOG_ERR, "Successfully dropped root privileges."); + + daemon_log(LOG_INFO, "Successfully dropped root privileges."); } - + return 0; } @@ -711,26 +1052,28 @@ static int loop(int iface, uint32_t addr) { FD_ARP, FD_IFACE, FD_SIGNAL, - FD_MAX, + FD_MAX }; int fd = -1, ret = -1; struct timeval next_wakeup; int next_wakeup_valid = 0; char buf[64]; - void *in_packet = NULL; - size_t in_packet_len; - void *out_packet = NULL; + 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; + 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); + daemon_signal_init(SIGINT, SIGTERM, SIGCHLD, SIGHUP, 0); if (!(dispatcher = fork_dispatcher())) goto fail; @@ -749,8 +1092,24 @@ static int loop(int iface, uint32_t addr) { else if (iface_get_initial_state(&st) < 0) goto fail; +#ifdef HAVE_CHROOT + if (!no_chroot) + p = ""; + else +#endif + p = AVAHI_IPDATA_DIR; + + address_fn = avahi_strdup_printf( + "%s/%02x:%02x:%02x:%02x:%02x:%02x", p, + hw_address[0], hw_address[1], + hw_address[2], hw_address[3], + hw_address[4], hw_address[5]); + + if (!addr) + load_address(address_fn, &addr); + if (addr && !is_ll_address(addr)) { - daemon_log(LOG_WARNING, "Requested address %s is not from IPv4LL range 169.254/16, ignoring.", inet_ntop(AF_INET, &addr, buf, sizeof(buf))); + 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; } @@ -761,11 +1120,15 @@ static int loop(int iface, uint32_t addr) { 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) @@ -783,7 +1146,7 @@ static int loop(int iface, uint32_t addr) { pollfds[FD_IFACE].events = POLLIN; pollfds[FD_SIGNAL].fd = daemon_signal_fd(); pollfds[FD_SIGNAL].events = POLLIN; - + for (;;) { int r, timeout; AvahiUsec usec; @@ -805,7 +1168,7 @@ static int loop(int iface, uint32_t 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 */ @@ -814,7 +1177,7 @@ static int loop(int iface, uint32_t 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)) { @@ -824,17 +1187,12 @@ static int loop(int iface, uint32_t 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; - if (!retval_sent) { - daemon_retval_send(0); - retval_sent = 1; - } + n_conflict = 0; } } else if ((state == STATE_ANNOUNCING && event == EVENT_TIMEOUT && n_iteration >= ANNOUNCE_NUM-1)) { @@ -843,33 +1201,47 @@ static int loop(int iface, uint32_t addr) { set_state(STATE_RUNNING, 0, addr); next_wakeup_valid = 0; - + + save_address(address_fn, addr); + + if (!retval_sent) { + daemon_retval_send(0); + retval_sent = 1; + } + } else if (event == EVENT_PACKET) { ArpPacketInfo info; 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) { - /* Normal conflict */ - conflict = 1; - daemon_log(LOG_INFO, "Recieved conflicting normal ARP packet."); + + 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); - daemon_log(LOG_INFO, "Recieved conflicting probe ARP packet."); + + 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); @@ -878,7 +1250,7 @@ static int loop(int iface, uint32_t addr) { 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); @@ -889,8 +1261,8 @@ static int loop(int iface, uint32_t addr) { } else DEBUG(daemon_log(LOG_DEBUG, "Ignoring irrelevant ARP packet.")); } - - } else if (event == EVENT_ROUTABLE_ADDR_CONFIGURED) { + + } else if (event == EVENT_ROUTABLE_ADDR_CONFIGURED && !force_bind) { daemon_log(LOG_INFO, "A routable address has been configured."); @@ -902,10 +1274,10 @@ static int loop(int iface, uint32_t addr) { 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."); @@ -915,11 +1287,11 @@ static int loop(int iface, uint32_t addr) { elapse_time(&next_wakeup, 0, PROBE_WAIT*1000); next_wakeup_valid = 1; - } else if (event == EVENT_REFRESH_REQUEST && state == STATE_RUNNING && !force_bind) { + } 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); @@ -927,13 +1299,13 @@ static int loop(int iface, uint32_t 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; } @@ -945,14 +1317,14 @@ static int loop(int iface, uint32_t addr) { 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) ; @@ -963,27 +1335,27 @@ static int loop(int iface, uint32_t addr) { 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(fd); + + 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; } @@ -991,7 +1363,7 @@ static int loop(int iface, uint32_t addr) { if (event == EVENT_NULL && pollfds[FD_IFACE].revents) { - + assert(pollfds[FD_IFACE].revents == POLLIN); if (iface_process(&event) < 0) @@ -1019,18 +1391,18 @@ static int loop(int iface, uint32_t addr) { case SIGCHLD: waitpid(-1, NULL, WNOHANG); break; - + case SIGHUP: event = EVENT_REFRESH_REQUEST; break; } - + } } } ret = 0; - + fail: if (state == STATE_RUNNING || state == STATE_ANNOUNCING) @@ -1038,9 +1410,9 @@ fail: avahi_free(out_packet); avahi_free(in_packet); - + if (fd >= 0) - close(fd); + close_socket(fd); if (iface_fd >= 0) iface_done(); @@ -1050,7 +1422,10 @@ fail: if (dispatcher) fclose(dispatcher); - + + if (address_fn) + avahi_free(address_fn); + return ret; } @@ -1062,19 +1437,21 @@ static void help(FILE *f, const char *a0) { " -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 to refresh it's IP address\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 routable address\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 +#ifdef HAVE_CHROOT " --no-chroot Don't chroot()\n" -#endif +#endif " --no-proc-title Don't modify process title\n" " --debug Increase verbosity\n", a0); @@ -1082,7 +1459,7 @@ static void help(FILE *f, const char *a0) { static int parse_command_line(int argc, char *argv[]) { int c; - + enum { OPTION_NO_PROC_TITLE = 256, OPTION_FORCE_BIND, @@ -1090,9 +1467,9 @@ static int parse_command_line(int argc, char *argv[]) { OPTION_NO_DROP_ROOT, #ifdef HAVE_CHROOT OPTION_NO_CHROOT -#endif +#endif }; - + static const struct option long_options[] = { { "help", no_argument, NULL, 'h' }, { "daemonize", no_argument, NULL, 'D' }, @@ -1102,19 +1479,19 @@ static int parse_command_line(int argc, char *argv[]) { { "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 +#ifdef HAVE_CHROOT { "no-chroot", no_argument, NULL, OPTION_NO_CHROOT }, -#endif +#endif { "no-proc-title", no_argument, NULL, OPTION_NO_PROC_TITLE }, { "debug", no_argument, NULL, OPTION_DEBUG }, { NULL, 0, NULL, 0 } }; - opterr = 0; - while ((c = getopt_long(argc, argv, "hDskrcVS:w", long_options, NULL)) >= 0) { + while ((c = getopt_long(argc, argv, "hDskrcVS:t:w", long_options, NULL)) >= 0) { switch(c) { case 's': @@ -1139,16 +1516,20 @@ static int parse_command_line(int argc, char *argv[]) { 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; @@ -1172,7 +1553,6 @@ static int parse_command_line(int argc, char *argv[]) { #endif default: - fprintf(stderr, "Invalid command line argument: %c\n", c); return -1; } } @@ -1194,7 +1574,10 @@ static int parse_command_line(int argc, char *argv[]) { fprintf(stderr, "Too many arguments\n"); return -1; } - + + if (!action_script) + action_script = avahi_strdup(AVAHI_IPCONF_SCRIPT); + return 0; } @@ -1207,14 +1590,14 @@ int main(int argc, char*argv[]) { 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; @@ -1230,7 +1613,7 @@ int main(int argc, char*argv[]) { 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; @@ -1248,7 +1631,7 @@ int main(int argc, char*argv[]) { if (daemonize) { daemon_retval_init(); - + if ((pid = daemon_fork()) < 0) goto finish; else if (pid != 0) { @@ -1282,25 +1665,25 @@ int main(int argc, char*argv[]) { 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) { @@ -1317,7 +1700,7 @@ finish: if (daemonize) daemon_retval_done(); - + if (wrote_pid_file) daemon_pid_file_remove(); @@ -1325,13 +1708,7 @@ finish: avahi_free(pid_file_name); avahi_free(argv0); avahi_free(interface_name); + avahi_free(action_script); return r; } - -/* TODO: - -- store last used address -- man page - -*/