X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=avahi-autoipd%2Fmain.c;h=60fc8aa01719cf7a971060d0984d8f57935e8e2e;hb=1d4f819072e901518309aff781f9f1e7272dca87;hp=82dba887a1bfda38ac88f8a9d7387f244703ee78;hpb=7bf6b7b95b7c3327000794a24e104242598a9f3f;p=catta diff --git a/avahi-autoipd/main.c b/avahi-autoipd/main.c index 82dba88..60fc8aa 100644 --- a/avahi-autoipd/main.c +++ b/avahi-autoipd/main.c @@ -43,6 +43,8 @@ #include #include #include +#include +#include #include #include @@ -79,6 +81,7 @@ #define IPV4LL_NETWORK 0xA9FE0000L #define IPV4LL_NETMASK 0xFFFF0000L #define IPV4LL_HOSTMASK 0x0000FFFFL +#define IPV4LL_BROADCAST 0xA9FEFFFFL #define ETHER_ADDRLEN 6 #define ARP_PACKET_SIZE (8+4+4+2*ETHER_ADDRLEN) @@ -109,6 +112,11 @@ static int use_syslog = 0; static int debug = 0; static int modify_proc_title = 1; static int force_bind = 0; +#ifdef HAVE_CHROOT +static int no_chroot = 0; +#endif +static int no_drop_root = 0; +static int wrote_pid_file = 0; static enum { DAEMON_RUN, @@ -178,11 +186,69 @@ static uint32_t pick_addr(uint32_t old_addr) { addr = htonl(IPV4LL_NETWORK | (uint32_t) r); - } while (addr == old_addr); + } while (addr == old_addr || !is_ll_address(addr)); return addr; } +static int load_address(const char *fn, uint32_t *addr) { + FILE *f; + unsigned a, b, c, d; + + assert(fn); + assert(addr); + + if (!(f = fopen(fn, "r"))) { + + if (errno == ENOENT) { + *addr = 0; + return 0; + } + + daemon_log(LOG_ERR, "fopen() failed: %s", strerror(errno)); + goto fail; + } + + if (fscanf(f, "%u.%u.%u.%u\n", &a, &b, &c, &d) != 4) { + daemon_log(LOG_ERR, "Parse failure"); + goto fail; + } + + fclose(f); + + *addr = htonl((a << 24) | (b << 16) | (c << 8) | d); + return 0; + +fail: + if (f) + fclose(f); + + return -1; +} + +static int save_address(const char *fn, uint32_t addr) { + FILE *f; + char buf[32]; + + assert(fn); + + if (!(f = fopen(fn, "w"))) { + daemon_log(LOG_ERR, "fopen() failed: %s", strerror(errno)); + goto fail; + } + + fprintf(f, "%s\n", inet_ntop(AF_INET, &addr, buf, sizeof (buf))); + fclose(f); + + return 0; + +fail: + if (f) + fclose(f); + + return -1; +} + static void* packet_new(const ArpPacketInfo *info, size_t *packet_len) { uint8_t *r; @@ -278,16 +344,14 @@ static void set_state(State st, int reset_counter, uint32_t address) { n_iteration = 0; } - if (modify_proc_title) { - if (state == STATE_SLEEPING) - avahi_set_proc_title(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))); - } + 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) { @@ -437,7 +501,10 @@ fail: } int is_ll_address(uint32_t addr) { - return (ntohl(addr) & IPV4LL_NETMASK) == IPV4LL_NETWORK; + return + (ntohl(addr) & IPV4LL_NETMASK) == IPV4LL_NETWORK && + ntohl(addr) != IPV4LL_NETWORK && + ntohl(addr) != IPV4LL_BROADCAST; } static struct timeval *elapse_time(struct timeval *tv, unsigned msec, unsigned jitter) { @@ -478,7 +545,7 @@ static FILE* fork_dispatcher(void) { setsid(); - avahi_set_proc_title(argv0, "%s(%s): callout dispatcher", argv0, interface_name); + avahi_set_proc_title(argv0, "%s: [%s] callout dispatcher", argv0, interface_name); close(fds[1]); @@ -527,6 +594,14 @@ static FILE* fork_dispatcher(void) { 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); } @@ -573,6 +648,126 @@ static int do_callout(FILE *f, CalloutEvent event, int iface, uint32_t addr) { return 0; } +#define set_env(key, value) putenv(avahi_strdup_printf("%s=%s", (key), (value))) + +static int drop_privs(void) { + struct passwd *pw; + struct group * gr; + int r; + mode_t u; + + /* Get user/group ID */ + + if (!no_drop_root) { + + if (!(pw = getpwnam(AVAHI_AUTOIPD_USER))) { + daemon_log(LOG_ERR, "Failed to find user '"AVAHI_AUTOIPD_USER"'."); + return -1; + } + + if (!(gr = getgrnam(AVAHI_AUTOIPD_GROUP))) { + daemon_log(LOG_ERR, "Failed to find group '"AVAHI_AUTOIPD_GROUP"'."); + return -1; + } + + daemon_log(LOG_INFO, "Found user '"AVAHI_AUTOIPD_USER"' (UID %lu) and group '"AVAHI_AUTOIPD_GROUP"' (GID %lu).", (unsigned long) pw->pw_uid, (unsigned long) gr->gr_gid); + } + + /* Create directory */ + u = umask(0000); + r = mkdir(AVAHI_IPDATA_DIR, 0755); + umask(u); + + if (r < 0 && errno != EEXIST) { + daemon_log(LOG_ERR, "mkdir(\""AVAHI_IPDATA_DIR"\"): %s", strerror(errno)); + return -1; + } + + /* Convey working directory */ + + if (!no_drop_root) { + struct stat st; + + chown(AVAHI_IPDATA_DIR, pw->pw_uid, gr->gr_gid); + + if (stat(AVAHI_IPDATA_DIR, &st) < 0) { + daemon_log(LOG_ERR, "stat(): %s\n", strerror(errno)); + return -1; + } + + if (!S_ISDIR(st.st_mode) || st.st_uid != pw->pw_uid || st.st_gid != gr->gr_gid) { + daemon_log(LOG_ERR, "Failed to create runtime directory "AVAHI_IPDATA_DIR"."); + return -1; + } + } + +#ifdef HAVE_CHROOT + + if (!no_chroot) { + if (chroot(AVAHI_IPDATA_DIR) < 0) { + daemon_log(LOG_ERR, "Failed to chroot(): %s", strerror(errno)); + return -1; + } + + daemon_log(LOG_INFO, "Successfully called chroot()."); + chdir("/"); + + /* Since we are now trapped inside a chroot we cannot remove + * the pid file anymore, the helper process will do that for us. */ + wrote_pid_file = 0; + } + +#endif + + if (!no_drop_root) { + + if (initgroups(AVAHI_AUTOIPD_USER, gr->gr_gid) != 0) { + daemon_log(LOG_ERR, "Failed to change group list: %s", strerror(errno)); + return -1; + } + +#if defined(HAVE_SETRESGID) + r = setresgid(gr->gr_gid, gr->gr_gid, gr->gr_gid); +#elif defined(HAVE_SETEGID) + if ((r = setgid(gr->gr_gid)) >= 0) + r = setegid(gr->gr_gid); +#elif defined(HAVE_SETREGID) + r = setregid(gr->gr_gid, gr->gr_gid); +#else +#error "No API to drop priviliges" +#endif + + if (r < 0) { + daemon_log(LOG_ERR, "Failed to change GID: %s", strerror(errno)); + return -1; + } + +#if defined(HAVE_SETRESUID) + r = setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid); +#elif defined(HAVE_SETEUID) + if ((r = setuid(pw->pw_uid)) >= 0) + r = seteuid(pw->pw_uid); +#elif defined(HAVE_SETREUID) + r = setreuid(pw->pw_uid, pw->pw_uid); +#else +#error "No API to drop priviliges" +#endif + + if (r < 0) { + daemon_log(LOG_ERR, "Failed to change UID: %s", strerror(errno)); + return -1; + } + + set_env("USER", pw->pw_name); + set_env("LOGNAME", pw->pw_name); + set_env("HOME", pw->pw_dir); + + daemon_log(LOG_ERR, "Successfully dropped root privileges."); + } + + return 0; +} + static int loop(int iface, uint32_t addr) { enum { FD_ARP, @@ -596,6 +791,8 @@ static int loop(int iface, uint32_t addr) { int retval_sent = !daemonize; State st; FILE *dispatcher = NULL; + char *address_fn = NULL; + const char *p; daemon_signal_init(SIGINT, SIGTERM, SIGCHLD, SIGHUP,0); @@ -608,14 +805,30 @@ static int loop(int iface, uint32_t addr) { if ((iface_fd = iface_init(iface)) < 0) goto fail; -/* if (drop_privs() < 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, ignoring.", inet_ntop(AF_INET, &addr, buf, sizeof(buf))); addr = 0; @@ -697,11 +910,6 @@ static int loop(int iface, uint32_t addr) { goto fail; n_conflict = 0; - - if (!retval_sent) { - daemon_retval_send(0); - retval_sent = 1; - } } } else if ((state == STATE_ANNOUNCING && event == EVENT_TIMEOUT && n_iteration >= ANNOUNCE_NUM-1)) { @@ -710,7 +918,14 @@ static int loop(int iface, uint32_t addr) { set_state(STATE_RUNNING, 0, addr); next_wakeup_valid = 0; + + save_address(address_fn, addr); + if (!retval_sent) { + daemon_retval_send(0); + retval_sent = 1; + } + } else if (event == EVENT_PACKET) { ArpPacketInfo info; @@ -728,7 +943,9 @@ static int loop(int iface, uint32_t addr) { } 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, "Recieved conflicting probe ARP packet."); } if (conflict) { @@ -917,6 +1134,9 @@ fail: if (dispatcher) fclose(dispatcher); + + if (address_fn) + avahi_free(address_fn); return ret; } @@ -936,9 +1156,13 @@ static void help(FILE *f, const char *a0) { " 169.254.0.0/16\n" " -w --wait Wait until an address has been acquired before\n" " daemonizing\n" - " --no-proc-title Don't modify process title\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 + " --no-chroot Don't chroot()\n" +#endif + " --no-proc-title Don't modify process title\n" " --debug Increase verbosity\n", a0); } @@ -949,7 +1173,11 @@ static int parse_command_line(int argc, char *argv[]) { enum { OPTION_NO_PROC_TITLE = 256, OPTION_FORCE_BIND, - OPTION_DEBUG + OPTION_DEBUG, + OPTION_NO_DROP_ROOT, +#ifdef HAVE_CHROOT + OPTION_NO_CHROOT +#endif }; static const struct option long_options[] = { @@ -962,8 +1190,12 @@ static int parse_command_line(int argc, char *argv[]) { { "version", no_argument, NULL, 'V' }, { "start", required_argument, NULL, 'S' }, { "wait", no_argument, NULL, 'w' }, - { "no-proc-title", no_argument, NULL, OPTION_NO_PROC_TITLE }, { "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 } }; @@ -1016,8 +1248,18 @@ static int parse_command_line(int argc, char *argv[]) { force_bind = 1; break; + case OPTION_NO_DROP_ROOT: + no_drop_root = 1; + break; + +#ifdef HAVE_CHROOT + case OPTION_NO_CHROOT: + no_chroot = 1; + break; +#endif + default: - fprintf(stderr, "Invalid command line argument: %c\n", c); + fprintf(stderr, "Invalid command line argument: %s\n", argv[optind-1]); return -1; } } @@ -1049,25 +1291,23 @@ static const char* pid_file_proc(void) { int main(int argc, char*argv[]) { int r = 1; - int wrote_pid_file = 0; char *log_ident = NULL; - avahi_init_proc_title(argc, argv); - signal(SIGPIPE, SIG_IGN); if ((argv0 = strrchr(argv[0], '/'))) - argv0++; + argv0 = avahi_strdup(argv0 + 1); else - argv0 = argv[0]; - - argv0 = avahi_strdup(argv0); + 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); @@ -1128,7 +1368,7 @@ int main(int argc, char*argv[]) { } else wrote_pid_file = 1; - avahi_set_proc_title(argv0, "%s(%s): starting up", argv0, interface_name); + avahi_set_proc_title(argv0, "%s: [%s] starting up", argv0, interface_name); if (loop(ifindex, start_address) < 0) goto finish; @@ -1175,11 +1415,3 @@ finish: return r; } - -/* TODO: - -- chroot/drop privs/caps -- store last used address -- man page - -*/