/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include #include #include #include #include #include #include "alloc-util.h" #include "bpf-firewall.h" #include "bus-error.h" #include "bus-util.h" #include "chase-symlinks.h" #include "copy.h" #include "dbus-socket.h" #include "dbus-unit.h" #include "def.h" #include "errno-list.h" #include "exit-status.h" #include "fd-util.h" #include "format-util.h" #include "in-addr-util.h" #include "io-util.h" #include "ip-protocol-list.h" #include "label.h" #include "log.h" #include "mkdir-label.h" #include "parse-util.h" #include "path-util.h" #include "process-util.h" #include "selinux-util.h" #include "serialize.h" #include "service.h" #include "signal-util.h" #include "smack-util.h" #include "socket.h" #include "socket-netlink.h" #include "special.h" #include "string-table.h" #include "string-util.h" #include "strv.h" #include "unit-name.h" #include "unit.h" #include "user-util.h" struct SocketPeer { unsigned n_ref; Socket *socket; union sockaddr_union peer; socklen_t peer_salen; }; static const UnitActiveState state_translation_table[_SOCKET_STATE_MAX] = { [SOCKET_DEAD] = UNIT_INACTIVE, [SOCKET_START_PRE] = UNIT_ACTIVATING, [SOCKET_START_CHOWN] = UNIT_ACTIVATING, [SOCKET_START_POST] = UNIT_ACTIVATING, [SOCKET_LISTENING] = UNIT_ACTIVE, [SOCKET_RUNNING] = UNIT_ACTIVE, [SOCKET_STOP_PRE] = UNIT_DEACTIVATING, [SOCKET_STOP_PRE_SIGTERM] = UNIT_DEACTIVATING, [SOCKET_STOP_PRE_SIGKILL] = UNIT_DEACTIVATING, [SOCKET_STOP_POST] = UNIT_DEACTIVATING, [SOCKET_FINAL_SIGTERM] = UNIT_DEACTIVATING, [SOCKET_FINAL_SIGKILL] = UNIT_DEACTIVATING, [SOCKET_FAILED] = UNIT_FAILED, [SOCKET_CLEANING] = UNIT_MAINTENANCE, }; static int socket_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata); static int socket_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata); static void flush_ports(Socket *s); static void socket_init(Unit *u) { Socket *s = SOCKET(u); assert(u); assert(u->load_state == UNIT_STUB); s->backlog = SOMAXCONN; s->timeout_usec = u->manager->default_timeout_start_usec; s->directory_mode = 0755; s->socket_mode = 0666; s->max_connections = 64; s->priority = -1; s->ip_tos = -1; s->ip_ttl = -1; s->mark = -1; s->exec_context.std_output = u->manager->default_std_output; s->exec_context.std_error = u->manager->default_std_error; s->control_command_id = _SOCKET_EXEC_COMMAND_INVALID; s->trigger_limit.interval = USEC_INFINITY; s->trigger_limit.burst = UINT_MAX; } static void socket_unwatch_control_pid(Socket *s) { assert(s); if (s->control_pid <= 0) return; unit_unwatch_pid(UNIT(s), TAKE_PID(s->control_pid)); } static void socket_cleanup_fd_list(SocketPort *p) { assert(p); close_many(p->auxiliary_fds, p->n_auxiliary_fds); p->auxiliary_fds = mfree(p->auxiliary_fds); p->n_auxiliary_fds = 0; } void socket_free_ports(Socket *s) { SocketPort *p; assert(s); while ((p = s->ports)) { LIST_REMOVE(port, s->ports, p); sd_event_source_unref(p->event_source); socket_cleanup_fd_list(p); safe_close(p->fd); free(p->path); free(p); } } static void socket_done(Unit *u) { Socket *s = SOCKET(u); SocketPeer *p; assert(s); socket_free_ports(s); while ((p = set_steal_first(s->peers_by_address))) p->socket = NULL; s->peers_by_address = set_free(s->peers_by_address); s->exec_runtime = exec_runtime_unref(s->exec_runtime, false); exec_command_free_array(s->exec_command, _SOCKET_EXEC_COMMAND_MAX); s->control_command = NULL; dynamic_creds_unref(&s->dynamic_creds); socket_unwatch_control_pid(s); unit_ref_unset(&s->service); s->tcp_congestion = mfree(s->tcp_congestion); s->bind_to_device = mfree(s->bind_to_device); s->smack = mfree(s->smack); s->smack_ip_in = mfree(s->smack_ip_in); s->smack_ip_out = mfree(s->smack_ip_out); strv_free(s->symlinks); s->user = mfree(s->user); s->group = mfree(s->group); s->fdname = mfree(s->fdname); s->timer_event_source = sd_event_source_disable_unref(s->timer_event_source); } static int socket_arm_timer(Socket *s, usec_t usec) { int r; assert(s); if (s->timer_event_source) { r = sd_event_source_set_time(s->timer_event_source, usec); if (r < 0) return r; return sd_event_source_set_enabled(s->timer_event_source, SD_EVENT_ONESHOT); } if (usec == USEC_INFINITY) return 0; r = sd_event_add_time( UNIT(s)->manager->event, &s->timer_event_source, CLOCK_MONOTONIC, usec, 0, socket_dispatch_timer, s); if (r < 0) return r; (void) sd_event_source_set_description(s->timer_event_source, "socket-timer"); return 0; } static bool have_non_accept_socket(Socket *s) { assert(s); if (!s->accept) return true; LIST_FOREACH(port, p, s->ports) { if (p->type != SOCKET_SOCKET) return true; if (!socket_address_can_accept(&p->address)) return true; } return false; } static int socket_add_mount_dependencies(Socket *s) { int r; assert(s); LIST_FOREACH(port, p, s->ports) { const char *path = NULL; if (p->type == SOCKET_SOCKET) path = socket_address_get_path(&p->address); else if (IN_SET(p->type, SOCKET_FIFO, SOCKET_SPECIAL, SOCKET_USB_FUNCTION)) path = p->path; if (!path) continue; r = unit_require_mounts_for(UNIT(s), path, UNIT_DEPENDENCY_FILE); if (r < 0) return r; } return 0; } static int socket_add_device_dependencies(Socket *s) { char *t; assert(s); if (!s->bind_to_device || streq(s->bind_to_device, "lo")) return 0; t = strjoina("/sys/subsystem/net/devices/", s->bind_to_device); return unit_add_node_dependency(UNIT(s), t, UNIT_BINDS_TO, UNIT_DEPENDENCY_FILE); } static int socket_add_default_dependencies(Socket *s) { int r; assert(s); if (!UNIT(s)->default_dependencies) return 0; r = unit_add_dependency_by_name(UNIT(s), UNIT_BEFORE, SPECIAL_SOCKETS_TARGET, true, UNIT_DEPENDENCY_DEFAULT); if (r < 0) return r; if (MANAGER_IS_SYSTEM(UNIT(s)->manager)) { r = unit_add_two_dependencies_by_name(UNIT(s), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, true, UNIT_DEPENDENCY_DEFAULT); if (r < 0) return r; } return unit_add_two_dependencies_by_name(UNIT(s), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, true, UNIT_DEPENDENCY_DEFAULT); } _pure_ static bool socket_has_exec(Socket *s) { unsigned i; assert(s); for (i = 0; i < _SOCKET_EXEC_COMMAND_MAX; i++) if (s->exec_command[i]) return true; return false; } static int socket_add_extras(Socket *s) { Unit *u = UNIT(s); int r; assert(s); /* Pick defaults for the trigger limit, if nothing was explicitly configured. We pick a relatively high limit * in Accept=yes mode, and a lower limit for Accept=no. Reason: in Accept=yes mode we are invoking accept() * ourselves before the trigger limit can hit, thus incoming connections are taken off the socket queue quickly * and reliably. This is different for Accept=no, where the spawned service has to take the incoming traffic * off the queues, which it might not necessarily do. Moreover, while Accept=no services are supposed to * process whatever is queued in one go, and thus should normally never have to be started frequently. This is * different for Accept=yes where each connection is processed by a new service instance, and thus frequent * service starts are typical. */ if (s->trigger_limit.interval == USEC_INFINITY) s->trigger_limit.interval = 2 * USEC_PER_SEC; if (s->trigger_limit.burst == UINT_MAX) { if (s->accept) s->trigger_limit.burst = 200; else s->trigger_limit.burst = 20; } if (have_non_accept_socket(s)) { if (!UNIT_DEREF(s->service)) { Unit *x; r = unit_load_related_unit(u, ".service", &x); if (r < 0) return r; unit_ref_set(&s->service, u, x); } r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, UNIT_DEREF(s->service), true, UNIT_DEPENDENCY_IMPLICIT); if (r < 0) return r; } r = socket_add_mount_dependencies(s); if (r < 0) return r; r = socket_add_device_dependencies(s); if (r < 0) return r; r = unit_patch_contexts(u); if (r < 0) return r; if (socket_has_exec(s)) { r = unit_add_exec_dependencies(u, &s->exec_context); if (r < 0) return r; } r = unit_set_default_slice(u); if (r < 0) return r; r = socket_add_default_dependencies(s); if (r < 0) return r; return 0; } static const char *socket_find_symlink_target(Socket *s) { const char *found = NULL; LIST_FOREACH(port, p, s->ports) { const char *f = NULL; switch (p->type) { case SOCKET_FIFO: f = p->path; break; case SOCKET_SOCKET: f = socket_address_get_path(&p->address); break; default: break; } if (f) { if (found) return NULL; found = f; } } return found; } static int socket_verify(Socket *s) { assert(s); assert(UNIT(s)->load_state == UNIT_LOADED); if (!s->ports) return log_unit_error_errno(UNIT(s), SYNTHETIC_ERRNO(ENOEXEC), "Unit has no Listen setting (ListenStream=, ListenDatagram=, ListenFIFO=, ...). Refusing."); if (s->accept && have_non_accept_socket(s)) return log_unit_error_errno(UNIT(s), SYNTHETIC_ERRNO(ENOEXEC), "Unit configured for accepting sockets, but sockets are non-accepting. Refusing."); if (s->accept && s->max_connections <= 0) return log_unit_error_errno(UNIT(s), SYNTHETIC_ERRNO(ENOEXEC), "MaxConnection= setting too small. Refusing."); if (s->accept && UNIT_DEREF(s->service)) return log_unit_error_errno(UNIT(s), SYNTHETIC_ERRNO(ENOEXEC), "Explicit service configuration for accepting socket units not supported. Refusing."); if (s->exec_context.pam_name && s->kill_context.kill_mode != KILL_CONTROL_GROUP) return log_unit_error_errno(UNIT(s), SYNTHETIC_ERRNO(ENOEXEC), "Unit has PAM enabled. Kill mode must be set to 'control-group'. Refusing."); if (!strv_isempty(s->symlinks) && !socket_find_symlink_target(s)) return log_unit_error_errno(UNIT(s), SYNTHETIC_ERRNO(ENOEXEC), "Unit has symlinks set but none or more than one node in the file system. Refusing."); return 0; } static void peer_address_hash_func(const SocketPeer *s, struct siphash *state) { assert(s); if (s->peer.sa.sa_family == AF_INET) siphash24_compress(&s->peer.in.sin_addr, sizeof(s->peer.in.sin_addr), state); else if (s->peer.sa.sa_family == AF_INET6) siphash24_compress(&s->peer.in6.sin6_addr, sizeof(s->peer.in6.sin6_addr), state); else if (s->peer.sa.sa_family == AF_VSOCK) siphash24_compress(&s->peer.vm.svm_cid, sizeof(s->peer.vm.svm_cid), state); else assert_not_reached(); } static int peer_address_compare_func(const SocketPeer *x, const SocketPeer *y) { int r; r = CMP(x->peer.sa.sa_family, y->peer.sa.sa_family); if (r != 0) return r; switch (x->peer.sa.sa_family) { case AF_INET: return memcmp(&x->peer.in.sin_addr, &y->peer.in.sin_addr, sizeof(x->peer.in.sin_addr)); case AF_INET6: return memcmp(&x->peer.in6.sin6_addr, &y->peer.in6.sin6_addr, sizeof(x->peer.in6.sin6_addr)); case AF_VSOCK: return CMP(x->peer.vm.svm_cid, y->peer.vm.svm_cid); } assert_not_reached(); } DEFINE_PRIVATE_HASH_OPS(peer_address_hash_ops, SocketPeer, peer_address_hash_func, peer_address_compare_func); static int socket_load(Unit *u) { Socket *s = SOCKET(u); int r; assert(u); assert(u->load_state == UNIT_STUB); r = unit_load_fragment_and_dropin(u, true); if (r < 0) return r; if (u->load_state != UNIT_LOADED) return 0; /* This is a new unit? Then let's add in some extras */ r = socket_add_extras(s); if (r < 0) return r; return socket_verify(s); } static SocketPeer *socket_peer_new(void) { SocketPeer *p; p = new(SocketPeer, 1); if (!p) return NULL; *p = (SocketPeer) { .n_ref = 1, }; return p; } static SocketPeer *socket_peer_free(SocketPeer *p) { assert(p); if (p->socket) set_remove(p->socket->peers_by_address, p); return mfree(p); } DEFINE_TRIVIAL_REF_UNREF_FUNC(SocketPeer, socket_peer, socket_peer_free); int socket_acquire_peer(Socket *s, int fd, SocketPeer **p) { _cleanup_(socket_peer_unrefp) SocketPeer *remote = NULL; SocketPeer sa = { .peer_salen = sizeof(union sockaddr_union), }, *i; int r; assert(fd >= 0); assert(s); if (getpeername(fd, &sa.peer.sa, &sa.peer_salen) < 0) return log_unit_error_errno(UNIT(s), errno, "getpeername failed: %m"); if (!IN_SET(sa.peer.sa.sa_family, AF_INET, AF_INET6, AF_VSOCK)) { *p = NULL; return 0; } r = set_ensure_allocated(&s->peers_by_address, &peer_address_hash_ops); if (r < 0) return r; i = set_get(s->peers_by_address, &sa); if (i) { *p = socket_peer_ref(i); return 1; } remote = socket_peer_new(); if (!remote) return log_oom(); remote->peer = sa.peer; remote->peer_salen = sa.peer_salen; r = set_put(s->peers_by_address, remote); if (r < 0) return r; remote->socket = s; *p = TAKE_PTR(remote); return 1; } _const_ static const char* listen_lookup(int family, int type) { if (family == AF_NETLINK) return "ListenNetlink"; if (type == SOCK_STREAM) return "ListenStream"; else if (type == SOCK_DGRAM) return "ListenDatagram"; else if (type == SOCK_SEQPACKET) return "ListenSequentialPacket"; assert_not_reached(); return NULL; } static void socket_dump(Unit *u, FILE *f, const char *prefix) { Socket *s = SOCKET(u); const char *prefix2, *str; assert(s); assert(f); prefix = strempty(prefix); prefix2 = strjoina(prefix, "\t"); fprintf(f, "%sSocket State: %s\n" "%sResult: %s\n" "%sClean Result: %s\n" "%sBindIPv6Only: %s\n" "%sBacklog: %u\n" "%sSocketMode: %04o\n" "%sDirectoryMode: %04o\n" "%sKeepAlive: %s\n" "%sNoDelay: %s\n" "%sFreeBind: %s\n" "%sTransparent: %s\n" "%sBroadcast: %s\n" "%sPassCredentials: %s\n" "%sPassSecurity: %s\n" "%sPassPacketInfo: %s\n" "%sTCPCongestion: %s\n" "%sRemoveOnStop: %s\n" "%sWritable: %s\n" "%sFileDescriptorName: %s\n" "%sSELinuxContextFromNet: %s\n", prefix, socket_state_to_string(s->state), prefix, socket_result_to_string(s->result), prefix, socket_result_to_string(s->clean_result), prefix, socket_address_bind_ipv6_only_to_string(s->bind_ipv6_only), prefix, s->backlog, prefix, s->socket_mode, prefix, s->directory_mode, prefix, yes_no(s->keep_alive), prefix, yes_no(s->no_delay), prefix, yes_no(s->free_bind), prefix, yes_no(s->transparent), prefix, yes_no(s->broadcast), prefix, yes_no(s->pass_cred), prefix, yes_no(s->pass_sec), prefix, yes_no(s->pass_pktinfo), prefix, strna(s->tcp_congestion), prefix, yes_no(s->remove_on_stop), prefix, yes_no(s->writable), prefix, socket_fdname(s), prefix, yes_no(s->selinux_context_from_net)); if (s->timestamping != SOCKET_TIMESTAMPING_OFF) fprintf(f, "%sTimestamping: %s\n", prefix, socket_timestamping_to_string(s->timestamping)); if (s->control_pid > 0) fprintf(f, "%sControl PID: "PID_FMT"\n", prefix, s->control_pid); if (s->bind_to_device) fprintf(f, "%sBindToDevice: %s\n", prefix, s->bind_to_device); if (s->accept) fprintf(f, "%sAccepted: %u\n" "%sNConnections: %u\n" "%sMaxConnections: %u\n" "%sMaxConnectionsPerSource: %u\n", prefix, s->n_accepted, prefix, s->n_connections, prefix, s->max_connections, prefix, s->max_connections_per_source); else fprintf(f, "%sFlushPending: %s\n", prefix, yes_no(s->flush_pending)); if (s->priority >= 0) fprintf(f, "%sPriority: %i\n", prefix, s->priority); if (s->receive_buffer > 0) fprintf(f, "%sReceiveBuffer: %zu\n", prefix, s->receive_buffer); if (s->send_buffer > 0) fprintf(f, "%sSendBuffer: %zu\n", prefix, s->send_buffer); if (s->ip_tos >= 0) fprintf(f, "%sIPTOS: %i\n", prefix, s->ip_tos); if (s->ip_ttl >= 0) fprintf(f, "%sIPTTL: %i\n", prefix, s->ip_ttl); if (s->pipe_size > 0) fprintf(f, "%sPipeSize: %zu\n", prefix, s->pipe_size); if (s->mark >= 0) fprintf(f, "%sMark: %i\n", prefix, s->mark); if (s->mq_maxmsg > 0) fprintf(f, "%sMessageQueueMaxMessages: %li\n", prefix, s->mq_maxmsg); if (s->mq_msgsize > 0) fprintf(f, "%sMessageQueueMessageSize: %li\n", prefix, s->mq_msgsize); if (s->reuse_port) fprintf(f, "%sReusePort: %s\n", prefix, yes_no(s->reuse_port)); if (s->smack) fprintf(f, "%sSmackLabel: %s\n", prefix, s->smack); if (s->smack_ip_in) fprintf(f, "%sSmackLabelIPIn: %s\n", prefix, s->smack_ip_in); if (s->smack_ip_out) fprintf(f, "%sSmackLabelIPOut: %s\n", prefix, s->smack_ip_out); if (!isempty(s->user) || !isempty(s->group)) fprintf(f, "%sSocketUser: %s\n" "%sSocketGroup: %s\n", prefix, strna(s->user), prefix, strna(s->group)); if (s->keep_alive_time > 0) fprintf(f, "%sKeepAliveTimeSec: %s\n", prefix, FORMAT_TIMESPAN(s->keep_alive_time, USEC_PER_SEC)); if (s->keep_alive_interval > 0) fprintf(f, "%sKeepAliveIntervalSec: %s\n", prefix, FORMAT_TIMESPAN(s->keep_alive_interval, USEC_PER_SEC)); if (s->keep_alive_cnt > 0) fprintf(f, "%sKeepAliveProbes: %u\n", prefix, s->keep_alive_cnt); if (s->defer_accept > 0) fprintf(f, "%sDeferAcceptSec: %s\n", prefix, FORMAT_TIMESPAN(s->defer_accept, USEC_PER_SEC)); LIST_FOREACH(port, p, s->ports) { switch (p->type) { case SOCKET_SOCKET: { _cleanup_free_ char *k = NULL; const char *t; int r; r = socket_address_print(&p->address, &k); if (r < 0) t = strerror_safe(r); else t = k; fprintf(f, "%s%s: %s\n", prefix, listen_lookup(socket_address_family(&p->address), p->address.type), t); break; } case SOCKET_SPECIAL: fprintf(f, "%sListenSpecial: %s\n", prefix, p->path); break; case SOCKET_USB_FUNCTION: fprintf(f, "%sListenUSBFunction: %s\n", prefix, p->path); break; case SOCKET_MQUEUE: fprintf(f, "%sListenMessageQueue: %s\n", prefix, p->path); break; default: fprintf(f, "%sListenFIFO: %s\n", prefix, p->path); } } fprintf(f, "%sTriggerLimitIntervalSec: %s\n" "%sTriggerLimitBurst: %u\n", prefix, FORMAT_TIMESPAN(s->trigger_limit.interval, USEC_PER_SEC), prefix, s->trigger_limit.burst); str = ip_protocol_to_name(s->socket_protocol); if (str) fprintf(f, "%sSocketProtocol: %s\n", prefix, str); if (!strv_isempty(s->symlinks)) { fprintf(f, "%sSymlinks:", prefix); STRV_FOREACH(q, s->symlinks) fprintf(f, " %s", *q); fprintf(f, "\n"); } fprintf(f, "%sTimeoutSec: %s\n", prefix, FORMAT_TIMESPAN(s->timeout_usec, USEC_PER_SEC)); exec_context_dump(&s->exec_context, f, prefix); kill_context_dump(&s->kill_context, f, prefix); for (SocketExecCommand c = 0; c < _SOCKET_EXEC_COMMAND_MAX; c++) { if (!s->exec_command[c]) continue; fprintf(f, "%s-> %s:\n", prefix, socket_exec_command_to_string(c)); exec_command_dump_list(s->exec_command[c], f, prefix2); } cgroup_context_dump(UNIT(s), f, prefix); } static int instance_from_socket(int fd, unsigned nr, char **instance) { socklen_t l; char *r; union sockaddr_union local, remote; assert(fd >= 0); assert(instance); l = sizeof(local); if (getsockname(fd, &local.sa, &l) < 0) return -errno; l = sizeof(remote); if (getpeername(fd, &remote.sa, &l) < 0) return -errno; switch (local.sa.sa_family) { case AF_INET: { uint32_t a = be32toh(local.in.sin_addr.s_addr), b = be32toh(remote.in.sin_addr.s_addr); if (asprintf(&r, "%u-%u.%u.%u.%u:%u-%u.%u.%u.%u:%u", nr, a >> 24, (a >> 16) & 0xFF, (a >> 8) & 0xFF, a & 0xFF, be16toh(local.in.sin_port), b >> 24, (b >> 16) & 0xFF, (b >> 8) & 0xFF, b & 0xFF, be16toh(remote.in.sin_port)) < 0) return -ENOMEM; break; } case AF_INET6: { static const unsigned char ipv4_prefix[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF }; if (memcmp(&local.in6.sin6_addr, ipv4_prefix, sizeof(ipv4_prefix)) == 0 && memcmp(&remote.in6.sin6_addr, ipv4_prefix, sizeof(ipv4_prefix)) == 0) { const uint8_t *a = local.in6.sin6_addr.s6_addr+12, *b = remote.in6.sin6_addr.s6_addr+12; if (asprintf(&r, "%u-%u.%u.%u.%u:%u-%u.%u.%u.%u:%u", nr, a[0], a[1], a[2], a[3], be16toh(local.in6.sin6_port), b[0], b[1], b[2], b[3], be16toh(remote.in6.sin6_port)) < 0) return -ENOMEM; } else { char a[INET6_ADDRSTRLEN], b[INET6_ADDRSTRLEN]; if (asprintf(&r, "%u-%s:%u-%s:%u", nr, inet_ntop(AF_INET6, &local.in6.sin6_addr, a, sizeof(a)), be16toh(local.in6.sin6_port), inet_ntop(AF_INET6, &remote.in6.sin6_addr, b, sizeof(b)), be16toh(remote.in6.sin6_port)) < 0) return -ENOMEM; } break; } case AF_UNIX: { struct ucred ucred; int k; k = getpeercred(fd, &ucred); if (k >= 0) { if (asprintf(&r, "%u-"PID_FMT"-"UID_FMT, nr, ucred.pid, ucred.uid) < 0) return -ENOMEM; } else if (k == -ENODATA) { /* This handles the case where somebody is * connecting from another pid/uid namespace * (e.g. from outside of our container). */ if (asprintf(&r, "%u-unknown", nr) < 0) return -ENOMEM; } else return k; break; } case AF_VSOCK: if (asprintf(&r, "%u-%u:%u-%u:%u", nr, local.vm.svm_cid, local.vm.svm_port, remote.vm.svm_cid, remote.vm.svm_port) < 0) return -ENOMEM; break; default: assert_not_reached(); } *instance = r; return 0; } static void socket_close_fds(Socket *s) { assert(s); LIST_FOREACH(port, p, s->ports) { bool was_open; was_open = p->fd >= 0; p->event_source = sd_event_source_disable_unref(p->event_source); p->fd = safe_close(p->fd); socket_cleanup_fd_list(p); /* One little note: we should normally not delete any sockets in the file system here! After all some * other process we spawned might still have a reference of this fd and wants to continue to use * it. Therefore we normally delete sockets in the file system before we create a new one, not after we * stopped using one! That all said, if the user explicitly requested this, we'll delete them here * anyway, but only then. */ if (!was_open || !s->remove_on_stop) continue; switch (p->type) { case SOCKET_FIFO: (void) unlink(p->path); break; case SOCKET_MQUEUE: (void) mq_unlink(p->path); break; case SOCKET_SOCKET: (void) socket_address_unlink(&p->address); break; default: break; } } if (s->remove_on_stop) STRV_FOREACH(i, s->symlinks) (void) unlink(*i); /* Note that we don't return NULL here, since s has not been freed. */ } static void socket_apply_socket_options(Socket *s, SocketPort *p, int fd) { int r; assert(s); assert(p); assert(fd >= 0); if (s->keep_alive) { r = setsockopt_int(fd, SOL_SOCKET, SO_KEEPALIVE, true); if (r < 0) log_unit_warning_errno(UNIT(s), r, "SO_KEEPALIVE failed: %m"); } if (s->keep_alive_time > 0) { r = setsockopt_int(fd, SOL_TCP, TCP_KEEPIDLE, s->keep_alive_time / USEC_PER_SEC); if (r < 0) log_unit_warning_errno(UNIT(s), r, "TCP_KEEPIDLE failed: %m"); } if (s->keep_alive_interval > 0) { r = setsockopt_int(fd, SOL_TCP, TCP_KEEPINTVL, s->keep_alive_interval / USEC_PER_SEC); if (r < 0) log_unit_warning_errno(UNIT(s), r, "TCP_KEEPINTVL failed: %m"); } if (s->keep_alive_cnt > 0) { r = setsockopt_int(fd, SOL_TCP, TCP_KEEPCNT, s->keep_alive_cnt); if (r < 0) log_unit_warning_errno(UNIT(s), r, "TCP_KEEPCNT failed: %m"); } if (s->defer_accept > 0) { r = setsockopt_int(fd, SOL_TCP, TCP_DEFER_ACCEPT, s->defer_accept / USEC_PER_SEC); if (r < 0) log_unit_warning_errno(UNIT(s), r, "TCP_DEFER_ACCEPT failed: %m"); } if (s->no_delay) { if (s->socket_protocol == IPPROTO_SCTP) { r = setsockopt_int(fd, SOL_SCTP, SCTP_NODELAY, true); if (r < 0) log_unit_warning_errno(UNIT(s), r, "SCTP_NODELAY failed: %m"); } else { r = setsockopt_int(fd, SOL_TCP, TCP_NODELAY, true); if (r < 0) log_unit_warning_errno(UNIT(s), r, "TCP_NODELAY failed: %m"); } } if (s->broadcast) { r = setsockopt_int(fd, SOL_SOCKET, SO_BROADCAST, true); if (r < 0) log_unit_warning_errno(UNIT(s), r, "SO_BROADCAST failed: %m"); } if (s->pass_cred) { r = setsockopt_int(fd, SOL_SOCKET, SO_PASSCRED, true); if (r < 0) log_unit_warning_errno(UNIT(s), r, "SO_PASSCRED failed: %m"); } if (s->pass_sec) { r = setsockopt_int(fd, SOL_SOCKET, SO_PASSSEC, true); if (r < 0) log_unit_warning_errno(UNIT(s), r, "SO_PASSSEC failed: %m"); } if (s->pass_pktinfo) { r = socket_set_recvpktinfo(fd, socket_address_family(&p->address), true); if (r < 0) log_unit_warning_errno(UNIT(s), r, "Failed to enable packet info socket option: %m"); } if (s->timestamping != SOCKET_TIMESTAMPING_OFF) { r = setsockopt_int(fd, SOL_SOCKET, s->timestamping == SOCKET_TIMESTAMPING_NS ? SO_TIMESTAMPNS : SO_TIMESTAMP, true); if (r < 0) log_unit_warning_errno(UNIT(s), r, "Failed to enable timestamping socket option, ignoring: %m"); } if (s->priority >= 0) { r = setsockopt_int(fd, SOL_SOCKET, SO_PRIORITY, s->priority); if (r < 0) log_unit_warning_errno(UNIT(s), r, "SO_PRIORITY failed: %m"); } if (s->receive_buffer > 0) { r = fd_set_rcvbuf(fd, s->receive_buffer, false); if (r < 0) log_unit_full_errno(UNIT(s), ERRNO_IS_PRIVILEGE(r) ? LOG_DEBUG : LOG_WARNING, r, "SO_RCVBUF/SO_RCVBUFFORCE failed: %m"); } if (s->send_buffer > 0) { r = fd_set_sndbuf(fd, s->send_buffer, false); if (r < 0) log_unit_full_errno(UNIT(s), ERRNO_IS_PRIVILEGE(r) ? LOG_DEBUG : LOG_WARNING, r, "SO_SNDBUF/SO_SNDBUFFORCE failed: %m"); } if (s->mark >= 0) { r = setsockopt_int(fd, SOL_SOCKET, SO_MARK, s->mark); if (r < 0) log_unit_warning_errno(UNIT(s), r, "SO_MARK failed: %m"); } if (s->ip_tos >= 0) { r = setsockopt_int(fd, IPPROTO_IP, IP_TOS, s->ip_tos); if (r < 0) log_unit_warning_errno(UNIT(s), r, "IP_TOS failed: %m"); } if (s->ip_ttl >= 0) { r = socket_set_ttl(fd, socket_address_family(&p->address), s->ip_ttl); if (r < 0) log_unit_warning_errno(UNIT(s), r, "IP_TTL/IPV6_UNICAST_HOPS failed: %m"); } if (s->tcp_congestion) if (setsockopt(fd, SOL_TCP, TCP_CONGESTION, s->tcp_congestion, strlen(s->tcp_congestion)+1) < 0) log_unit_warning_errno(UNIT(s), errno, "TCP_CONGESTION failed: %m"); if (s->smack_ip_in) { r = mac_smack_apply_fd(fd, SMACK_ATTR_IPIN, s->smack_ip_in); if (r < 0) log_unit_error_errno(UNIT(s), r, "mac_smack_apply_ip_in_fd: %m"); } if (s->smack_ip_out) { r = mac_smack_apply_fd(fd, SMACK_ATTR_IPOUT, s->smack_ip_out); if (r < 0) log_unit_error_errno(UNIT(s), r, "mac_smack_apply_ip_out_fd: %m"); } } static void socket_apply_fifo_options(Socket *s, int fd) { int r; assert(s); assert(fd >= 0); if (s->pipe_size > 0) if (fcntl(fd, F_SETPIPE_SZ, s->pipe_size) < 0) log_unit_warning_errno(UNIT(s), errno, "Setting pipe size failed, ignoring: %m"); if (s->smack) { r = mac_smack_apply_fd(fd, SMACK_ATTR_ACCESS, s->smack); if (r < 0) log_unit_error_errno(UNIT(s), r, "SMACK relabelling failed, ignoring: %m"); } } static int fifo_address_create( const char *path, mode_t directory_mode, mode_t socket_mode) { _cleanup_close_ int fd = -1; mode_t old_mask; struct stat st; int r; assert(path); (void) mkdir_parents_label(path, directory_mode); r = mac_selinux_create_file_prepare(path, S_IFIFO); if (r < 0) return r; /* Enforce the right access mode for the fifo */ old_mask = umask(~socket_mode); /* Include the original umask in our mask */ (void) umask(~socket_mode | old_mask); r = mkfifo(path, socket_mode); (void) umask(old_mask); if (r < 0 && errno != EEXIST) { r = -errno; goto fail; } fd = open(path, O_RDWR | O_CLOEXEC | O_NOCTTY | O_NONBLOCK | O_NOFOLLOW); if (fd < 0) { r = -errno; goto fail; } mac_selinux_create_file_clear(); if (fstat(fd, &st) < 0) { r = -errno; goto fail; } if (!S_ISFIFO(st.st_mode) || (st.st_mode & 0777) != (socket_mode & ~old_mask) || st.st_uid != getuid() || st.st_gid != getgid()) { r = -EEXIST; goto fail; } return TAKE_FD(fd); fail: mac_selinux_create_file_clear(); return r; } static int special_address_create(const char *path, bool writable) { _cleanup_close_ int fd = -1; struct stat st; assert(path); fd = open(path, (writable ? O_RDWR : O_RDONLY)|O_CLOEXEC|O_NOCTTY|O_NONBLOCK|O_NOFOLLOW); if (fd < 0) return -errno; if (fstat(fd, &st) < 0) return -errno; /* Check whether this is a /proc, /sys or /dev file or char device */ if (!S_ISREG(st.st_mode) && !S_ISCHR(st.st_mode)) return -EEXIST; return TAKE_FD(fd); } static int usbffs_address_create(const char *path) { _cleanup_close_ int fd = -1; struct stat st; assert(path); fd = open(path, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK|O_NOFOLLOW); if (fd < 0) return -errno; if (fstat(fd, &st) < 0) return -errno; /* Check whether this is a regular file (ffs endpoint) */ if (!S_ISREG(st.st_mode)) return -EEXIST; return TAKE_FD(fd); } static int mq_address_create( const char *path, mode_t mq_mode, long maxmsg, long msgsize) { _cleanup_close_ int fd = -1; struct stat st; mode_t old_mask; struct mq_attr _attr, *attr = NULL; assert(path); if (maxmsg > 0 && msgsize > 0) { _attr = (struct mq_attr) { .mq_flags = O_NONBLOCK, .mq_maxmsg = maxmsg, .mq_msgsize = msgsize, }; attr = &_attr; } /* Enforce the right access mode for the mq */ old_mask = umask(~mq_mode); /* Include the original umask in our mask */ (void) umask(~mq_mode | old_mask); fd = mq_open(path, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_CREAT, mq_mode, attr); (void) umask(old_mask); if (fd < 0) return -errno; if (fstat(fd, &st) < 0) return -errno; if ((st.st_mode & 0777) != (mq_mode & ~old_mask) || st.st_uid != getuid() || st.st_gid != getgid()) return -EEXIST; return TAKE_FD(fd); } static int socket_symlink(Socket *s) { const char *p; int r; assert(s); p = socket_find_symlink_target(s); if (!p) return 0; STRV_FOREACH(i, s->symlinks) { (void) mkdir_parents_label(*i, s->directory_mode); r = symlink_idempotent(p, *i, false); if (r == -EEXIST && s->remove_on_stop) { /* If there's already something where we want to create the symlink, and the destructive * RemoveOnStop= mode is set, then we might as well try to remove what already exists and try * again. */ if (unlink(*i) >= 0) r = symlink_idempotent(p, *i, false); } if (r < 0) log_unit_warning_errno(UNIT(s), r, "Failed to create symlink %s → %s, ignoring: %m", p, *i); } return 0; } static int usbffs_write_descs(int fd, Service *s) { int r; if (!s->usb_function_descriptors || !s->usb_function_strings) return -EINVAL; r = copy_file_fd(s->usb_function_descriptors, fd, 0); if (r < 0) return r; return copy_file_fd(s->usb_function_strings, fd, 0); } static int usbffs_select_ep(const struct dirent *d) { return d->d_name[0] != '.' && !streq(d->d_name, "ep0"); } static int usbffs_dispatch_eps(SocketPort *p) { _cleanup_free_ struct dirent **ent = NULL; size_t n, k; int r; r = scandir(p->path, &ent, usbffs_select_ep, alphasort); if (r < 0) return -errno; n = (size_t) r; p->auxiliary_fds = new(int, n); if (!p->auxiliary_fds) { r = -ENOMEM; goto clear; } p->n_auxiliary_fds = n; k = 0; for (size_t i = 0; i < n; ++i) { _cleanup_free_ char *ep = NULL; ep = path_make_absolute(ent[i]->d_name, p->path); if (!ep) { r = -ENOMEM; goto fail; } path_simplify(ep); r = usbffs_address_create(ep); if (r < 0) goto fail; p->auxiliary_fds[k++] = r; } r = 0; goto clear; fail: close_many(p->auxiliary_fds, k); p->auxiliary_fds = mfree(p->auxiliary_fds); p->n_auxiliary_fds = 0; clear: for (size_t i = 0; i < n; ++i) free(ent[i]); return r; } int socket_load_service_unit(Socket *s, int cfd, Unit **ret) { /* Figure out what the unit that will be used to handle the connections on the socket looks like. * * If cfd < 0, then we don't have a connection yet. In case of Accept=yes sockets, use a fake * instance name. */ if (UNIT_ISSET(s->service)) { *ret = UNIT_DEREF(s->service); return 0; } if (!s->accept) return -ENODATA; /* Build the instance name and load the unit */ _cleanup_free_ char *prefix = NULL, *instance = NULL, *name = NULL; int r; r = unit_name_to_prefix(UNIT(s)->id, &prefix); if (r < 0) return r; if (cfd >= 0) { r = instance_from_socket(cfd, s->n_accepted, &instance); if (ERRNO_IS_DISCONNECT(r)) /* ENOTCONN is legitimate if TCP RST was received. Other socket families might return * different errors. This connection is over, but the socket unit lives on. */ return log_unit_debug_errno(UNIT(s), r, "Got %s on incoming socket, assuming aborted connection attempt, ignoring.", errno_to_name(r)); if (r < 0) return r; } /* For accepting sockets, we don't know how the instance will be called until we get a connection and * can figure out what the peer name is. So let's use "internal" as the instance to make it clear * that this is not an actual peer name. We use "unknown" when we cannot figure out the peer. */ r = unit_name_build(prefix, instance ?: "internal", ".service", &name); if (r < 0) return r; return manager_load_unit(UNIT(s)->manager, name, NULL, NULL, ret); } static int socket_determine_selinux_label(Socket *s, char **ret) { int r; assert(s); assert(ret); if (s->selinux_context_from_net) { /* If this is requested, get the label from the network label */ r = mac_selinux_get_our_label(ret); if (r == -EOPNOTSUPP) goto no_label; } else { /* Otherwise, get it from the executable we are about to start. */ Unit *service; ExecCommand *c; _cleanup_free_ char *path = NULL; r = socket_load_service_unit(s, -1, &service); if (r == -ENODATA) goto no_label; if (r < 0) return r; c = SERVICE(service)->exec_command[SERVICE_EXEC_START]; if (!c) goto no_label; r = chase_symlinks(c->path, SERVICE(service)->exec_context.root_directory, CHASE_PREFIX_ROOT, &path, NULL); if (r < 0) goto no_label; r = mac_selinux_get_create_label_from_exe(path, ret); if (IN_SET(r, -EPERM, -EOPNOTSUPP)) goto no_label; } return r; no_label: *ret = NULL; return 0; } static int socket_address_listen_do( Socket *s, const SocketAddress *address, const char *label) { assert(s); assert(address); return socket_address_listen( address, SOCK_CLOEXEC|SOCK_NONBLOCK, s->backlog, s->bind_ipv6_only, s->bind_to_device, s->reuse_port, s->free_bind, s->transparent, s->directory_mode, s->socket_mode, label); } #define log_address_error_errno(u, address, error, fmt) \ ({ \ _cleanup_free_ char *_t = NULL; \ \ (void) socket_address_print(address, &_t); \ log_unit_error_errno(u, error, fmt, strna(_t)); \ }) static int fork_needed(const SocketAddress *address, const ExecContext *context) { int r; assert(address); assert(context); /* Check if we need to do the cgroup or netns stuff. If not we can do things much simpler. */ if (IN_SET(address->sockaddr.sa.sa_family, AF_INET, AF_INET6)) { r = bpf_firewall_supported(); if (r < 0) return r; if (r != BPF_FIREWALL_UNSUPPORTED) /* If BPF firewalling isn't supported anyway — there's no point in this forking complexity */ return true; } return context->private_network || context->network_namespace_path; } static int socket_address_listen_in_cgroup( Socket *s, const SocketAddress *address, const char *label) { _cleanup_close_pair_ int pair[2] = { -1, -1 }; int fd, r; pid_t pid; assert(s); assert(address); /* This is a wrapper around socket_address_listen(), that forks off a helper process inside the * socket's cgroup and network namespace in which the socket is actually created. This way we ensure * the socket is actually properly attached to the unit's cgroup for the purpose of BPF filtering and * such. */ r = fork_needed(address, &s->exec_context); if (r < 0) return r; if (r == 0) { /* Shortcut things... */ fd = socket_address_listen_do(s, address, label); if (fd < 0) return log_address_error_errno(UNIT(s), address, fd, "Failed to create listening socket (%s): %m"); return fd; } r = unit_setup_exec_runtime(UNIT(s)); if (r < 0) return log_unit_error_errno(UNIT(s), r, "Failed acquire runtime: %m"); if (s->exec_context.network_namespace_path && s->exec_runtime && s->exec_runtime->netns_storage_socket[0] >= 0) { r = open_shareable_ns_path(s->exec_runtime->netns_storage_socket, s->exec_context.network_namespace_path, CLONE_NEWNET); if (r < 0) return log_unit_error_errno(UNIT(s), r, "Failed to open network namespace path %s: %m", s->exec_context.network_namespace_path); } if (s->exec_context.ipc_namespace_path && s->exec_runtime && s->exec_runtime->ipcns_storage_socket[0] >= 0) { r = open_shareable_ns_path(s->exec_runtime->ipcns_storage_socket, s->exec_context.ipc_namespace_path, CLONE_NEWIPC); if (r < 0) return log_unit_error_errno(UNIT(s), r, "Failed to open IPC namespace path %s: %m", s->exec_context.ipc_namespace_path); } if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, pair) < 0) return log_unit_error_errno(UNIT(s), errno, "Failed to create communication channel: %m"); r = unit_fork_helper_process(UNIT(s), "(sd-listen)", &pid); if (r < 0) return log_unit_error_errno(UNIT(s), r, "Failed to fork off listener stub process: %m"); if (r == 0) { /* Child */ pair[0] = safe_close(pair[0]); if ((s->exec_context.private_network || s->exec_context.network_namespace_path) && s->exec_runtime && s->exec_runtime->netns_storage_socket[0] >= 0) { if (ns_type_supported(NAMESPACE_NET)) { r = setup_shareable_ns(s->exec_runtime->netns_storage_socket, CLONE_NEWNET); if (r < 0) { log_unit_error_errno(UNIT(s), r, "Failed to join network namespace: %m"); _exit(EXIT_NETWORK); } } else if (s->exec_context.network_namespace_path) { log_unit_error(UNIT(s), "Network namespace path configured but network namespaces not supported."); _exit(EXIT_NETWORK); } else log_unit_warning(UNIT(s), "PrivateNetwork=yes is configured, but the kernel does not support network namespaces, ignoring."); } fd = socket_address_listen_do(s, address, label); if (fd < 0) { log_address_error_errno(UNIT(s), address, fd, "Failed to create listening socket (%s): %m"); _exit(EXIT_FAILURE); } r = send_one_fd(pair[1], fd, 0); if (r < 0) { log_address_error_errno(UNIT(s), address, r, "Failed to send listening socket (%s) to parent: %m"); _exit(EXIT_FAILURE); } _exit(EXIT_SUCCESS); } pair[1] = safe_close(pair[1]); fd = receive_one_fd(pair[0], 0); /* We synchronously wait for the helper, as it shouldn't be slow */ r = wait_for_terminate_and_check("(sd-listen)", pid, WAIT_LOG_ABNORMAL); if (r < 0) { safe_close(fd); return r; } if (fd < 0) return log_address_error_errno(UNIT(s), address, fd, "Failed to receive listening socket (%s): %m"); return fd; } DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(Socket *, socket_close_fds, NULL); static int socket_open_fds(Socket *orig_s) { _cleanup_(socket_close_fdsp) Socket *s = orig_s; _cleanup_(mac_selinux_freep) char *label = NULL; bool know_label = false; int r; assert(s); LIST_FOREACH(port, p, s->ports) { if (p->fd >= 0) continue; switch (p->type) { case SOCKET_SOCKET: if (!know_label) { /* Figure out the label, if we don't it know yet. We do it once for the first * socket where we need this and remember it for the rest. */ r = socket_determine_selinux_label(s, &label); if (r < 0) return log_unit_error_errno(UNIT(s), r, "Failed to determine SELinux label: %m"); know_label = true; } /* Apply the socket protocol */ switch (p->address.type) { case SOCK_STREAM: case SOCK_SEQPACKET: if (s->socket_protocol == IPPROTO_SCTP) p->address.protocol = s->socket_protocol; break; case SOCK_DGRAM: if (s->socket_protocol == IPPROTO_UDPLITE) p->address.protocol = s->socket_protocol; break; } p->fd = socket_address_listen_in_cgroup(s, &p->address, label); if (p->fd < 0) return p->fd; socket_apply_socket_options(s, p, p->fd); socket_symlink(s); break; case SOCKET_SPECIAL: p->fd = special_address_create(p->path, s->writable); if (p->fd < 0) return log_unit_error_errno(UNIT(s), p->fd, "Failed to open special file %s: %m", p->path); break; case SOCKET_FIFO: p->fd = fifo_address_create( p->path, s->directory_mode, s->socket_mode); if (p->fd < 0) return log_unit_error_errno(UNIT(s), p->fd, "Failed to open FIFO %s: %m", p->path); socket_apply_fifo_options(s, p->fd); socket_symlink(s); break; case SOCKET_MQUEUE: p->fd = mq_address_create( p->path, s->socket_mode, s->mq_maxmsg, s->mq_msgsize); if (p->fd < 0) return log_unit_error_errno(UNIT(s), p->fd, "Failed to open message queue %s: %m", p->path); break; case SOCKET_USB_FUNCTION: { _cleanup_free_ char *ep = NULL; ep = path_make_absolute("ep0", p->path); if (!ep) return -ENOMEM; p->fd = usbffs_address_create(ep); if (p->fd < 0) return p->fd; r = usbffs_write_descs(p->fd, SERVICE(UNIT_DEREF(s->service))); if (r < 0) return r; r = usbffs_dispatch_eps(p); if (r < 0) return r; break; } default: assert_not_reached(); } } s = NULL; return 0; } static void socket_unwatch_fds(Socket *s) { int r; assert(s); LIST_FOREACH(port, p, s->ports) { if (p->fd < 0) continue; if (!p->event_source) continue; r = sd_event_source_set_enabled(p->event_source, SD_EVENT_OFF); if (r < 0) log_unit_debug_errno(UNIT(s), r, "Failed to disable event source: %m"); } } static int socket_watch_fds(Socket *s) { int r; assert(s); LIST_FOREACH(port, p, s->ports) { if (p->fd < 0) continue; if (p->event_source) { r = sd_event_source_set_enabled(p->event_source, SD_EVENT_ON); if (r < 0) goto fail; } else { r = sd_event_add_io(UNIT(s)->manager->event, &p->event_source, p->fd, EPOLLIN, socket_dispatch_io, p); if (r < 0) goto fail; (void) sd_event_source_set_description(p->event_source, "socket-port-io"); } } return 0; fail: log_unit_warning_errno(UNIT(s), r, "Failed to watch listening fds: %m"); socket_unwatch_fds(s); return r; } enum { SOCKET_OPEN_NONE, SOCKET_OPEN_SOME, SOCKET_OPEN_ALL, }; static int socket_check_open(Socket *s) { bool have_open = false, have_closed = false; assert(s); LIST_FOREACH(port, p, s->ports) { if (p->fd < 0) have_closed = true; else have_open = true; if (have_open && have_closed) return SOCKET_OPEN_SOME; } if (have_open) return SOCKET_OPEN_ALL; return SOCKET_OPEN_NONE; } static void socket_set_state(Socket *s, SocketState state) { SocketState old_state; assert(s); if (s->state != state) bus_unit_send_pending_change_signal(UNIT(s), false); old_state = s->state; s->state = state; if (!IN_SET(state, SOCKET_START_PRE, SOCKET_START_CHOWN, SOCKET_START_POST, SOCKET_STOP_PRE, SOCKET_STOP_PRE_SIGTERM, SOCKET_STOP_PRE_SIGKILL, SOCKET_STOP_POST, SOCKET_FINAL_SIGTERM, SOCKET_FINAL_SIGKILL, SOCKET_CLEANING)) { s->timer_event_source = sd_event_source_disable_unref(s->timer_event_source); socket_unwatch_control_pid(s); s->control_command = NULL; s->control_command_id = _SOCKET_EXEC_COMMAND_INVALID; } if (state != SOCKET_LISTENING) socket_unwatch_fds(s); if (!IN_SET(state, SOCKET_START_CHOWN, SOCKET_START_POST, SOCKET_LISTENING, SOCKET_RUNNING, SOCKET_STOP_PRE, SOCKET_STOP_PRE_SIGTERM, SOCKET_STOP_PRE_SIGKILL, SOCKET_CLEANING)) socket_close_fds(s); if (state != old_state) log_unit_debug(UNIT(s), "Changed %s -> %s", socket_state_to_string(old_state), socket_state_to_string(state)); unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], 0); } static int socket_coldplug(Unit *u) { Socket *s = SOCKET(u); int r; assert(s); assert(s->state == SOCKET_DEAD); if (s->deserialized_state == s->state) return 0; if (s->control_pid > 0 && pid_is_unwaited(s->control_pid) && IN_SET(s->deserialized_state, SOCKET_START_PRE, SOCKET_START_CHOWN, SOCKET_START_POST, SOCKET_STOP_PRE, SOCKET_STOP_PRE_SIGTERM, SOCKET_STOP_PRE_SIGKILL, SOCKET_STOP_POST, SOCKET_FINAL_SIGTERM, SOCKET_FINAL_SIGKILL, SOCKET_CLEANING)) { r = unit_watch_pid(UNIT(s), s->control_pid, false); if (r < 0) return r; r = socket_arm_timer(s, usec_add(u->state_change_timestamp.monotonic, s->timeout_usec)); if (r < 0) return r; } if (IN_SET(s->deserialized_state, SOCKET_START_CHOWN, SOCKET_START_POST, SOCKET_LISTENING, SOCKET_RUNNING)) { /* Originally, we used to simply reopen all sockets here that we didn't have file descriptors * for. However, this is problematic, as we won't traverse through the SOCKET_START_CHOWN state for * them, and thus the UID/GID wouldn't be right. Hence, instead simply check if we have all fds open, * and if there's a mismatch, warn loudly. */ r = socket_check_open(s); if (r == SOCKET_OPEN_NONE) log_unit_warning(UNIT(s), "Socket unit configuration has changed while unit has been running, " "no open socket file descriptor left. " "The socket unit is not functional until restarted."); else if (r == SOCKET_OPEN_SOME) log_unit_warning(UNIT(s), "Socket unit configuration has changed while unit has been running, " "and some socket file descriptors have not been opened yet. " "The socket unit is not fully functional until restarted."); } if (s->deserialized_state == SOCKET_LISTENING) { r = socket_watch_fds(s); if (r < 0) return r; } if (!IN_SET(s->deserialized_state, SOCKET_DEAD, SOCKET_FAILED, SOCKET_CLEANING)) { (void) unit_setup_dynamic_creds(u); (void) unit_setup_exec_runtime(u); } socket_set_state(s, s->deserialized_state); return 0; } static int socket_spawn(Socket *s, ExecCommand *c, pid_t *_pid) { _cleanup_(exec_params_clear) ExecParameters exec_params = { .flags = EXEC_APPLY_SANDBOXING|EXEC_APPLY_CHROOT|EXEC_APPLY_TTY_STDIN, .stdin_fd = -1, .stdout_fd = -1, .stderr_fd = -1, .exec_fd = -1, }; pid_t pid; int r; assert(s); assert(c); assert(_pid); r = unit_prepare_exec(UNIT(s)); if (r < 0) return r; r = socket_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_usec)); if (r < 0) return r; r = unit_set_exec_params(UNIT(s), &exec_params); if (r < 0) return r; r = exec_spawn(UNIT(s), c, &s->exec_context, &exec_params, s->exec_runtime, &s->dynamic_creds, &pid); if (r < 0) return r; r = unit_watch_pid(UNIT(s), pid, true); if (r < 0) return r; *_pid = pid; return 0; } static int socket_chown(Socket *s, pid_t *_pid) { pid_t pid; int r; r = socket_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_usec)); if (r < 0) goto fail; /* We have to resolve the user names out-of-process, hence * let's fork here. It's messy, but well, what can we do? */ r = unit_fork_helper_process(UNIT(s), "(sd-chown)", &pid); if (r < 0) return r; if (r == 0) { uid_t uid = UID_INVALID; gid_t gid = GID_INVALID; /* Child */ if (!isempty(s->user)) { const char *user = s->user; r = get_user_creds(&user, &uid, &gid, NULL, NULL, 0); if (r < 0) { log_unit_error_errno(UNIT(s), r, "Failed to resolve user %s: %m", user); _exit(EXIT_USER); } } if (!isempty(s->group)) { const char *group = s->group; r = get_group_creds(&group, &gid, 0); if (r < 0) { log_unit_error_errno(UNIT(s), r, "Failed to resolve group %s: %m", group); _exit(EXIT_GROUP); } } LIST_FOREACH(port, p, s->ports) { const char *path = NULL; if (p->type == SOCKET_SOCKET) path = socket_address_get_path(&p->address); else if (p->type == SOCKET_FIFO) path = p->path; if (!path) continue; if (chown(path, uid, gid) < 0) { log_unit_error_errno(UNIT(s), errno, "Failed to chown(): %m"); _exit(EXIT_CHOWN); } } _exit(EXIT_SUCCESS); } r = unit_watch_pid(UNIT(s), pid, true); if (r < 0) goto fail; *_pid = pid; return 0; fail: s->timer_event_source = sd_event_source_disable_unref(s->timer_event_source); return r; } static void socket_enter_dead(Socket *s, SocketResult f) { assert(s); if (s->result == SOCKET_SUCCESS) s->result = f; if (s->result == SOCKET_SUCCESS) unit_log_success(UNIT(s)); else unit_log_failure(UNIT(s), socket_result_to_string(s->result)); unit_warn_leftover_processes(UNIT(s), unit_log_leftover_process_stop); socket_set_state(s, s->result != SOCKET_SUCCESS ? SOCKET_FAILED : SOCKET_DEAD); s->exec_runtime = exec_runtime_unref(s->exec_runtime, true); unit_destroy_runtime_data(UNIT(s), &s->exec_context); unit_unref_uid_gid(UNIT(s), true); dynamic_creds_destroy(&s->dynamic_creds); } static void socket_enter_signal(Socket *s, SocketState state, SocketResult f); static void socket_enter_stop_post(Socket *s, SocketResult f) { int r; assert(s); if (s->result == SOCKET_SUCCESS) s->result = f; socket_unwatch_control_pid(s); s->control_command_id = SOCKET_EXEC_STOP_POST; s->control_command = s->exec_command[SOCKET_EXEC_STOP_POST]; if (s->control_command) { r = socket_spawn(s, s->control_command, &s->control_pid); if (r < 0) goto fail; socket_set_state(s, SOCKET_STOP_POST); } else socket_enter_signal(s, SOCKET_FINAL_SIGTERM, SOCKET_SUCCESS); return; fail: log_unit_warning_errno(UNIT(s), r, "Failed to run 'stop-post' task: %m"); socket_enter_signal(s, SOCKET_FINAL_SIGTERM, SOCKET_FAILURE_RESOURCES); } static int state_to_kill_operation(Socket *s, SocketState state) { if (state == SOCKET_STOP_PRE_SIGTERM && unit_has_job_type(UNIT(s), JOB_RESTART)) return KILL_RESTART; if (state == SOCKET_FINAL_SIGTERM) return KILL_TERMINATE; return KILL_KILL; } static void socket_enter_signal(Socket *s, SocketState state, SocketResult f) { int r; assert(s); if (s->result == SOCKET_SUCCESS) s->result = f; r = unit_kill_context( UNIT(s), &s->kill_context, state_to_kill_operation(s, state), -1, s->control_pid, false); if (r < 0) goto fail; if (r > 0) { r = socket_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_usec)); if (r < 0) goto fail; socket_set_state(s, state); } else if (state == SOCKET_STOP_PRE_SIGTERM) socket_enter_signal(s, SOCKET_STOP_PRE_SIGKILL, SOCKET_SUCCESS); else if (state == SOCKET_STOP_PRE_SIGKILL) socket_enter_stop_post(s, SOCKET_SUCCESS); else if (state == SOCKET_FINAL_SIGTERM) socket_enter_signal(s, SOCKET_FINAL_SIGKILL, SOCKET_SUCCESS); else socket_enter_dead(s, SOCKET_SUCCESS); return; fail: log_unit_warning_errno(UNIT(s), r, "Failed to kill processes: %m"); if (IN_SET(state, SOCKET_STOP_PRE_SIGTERM, SOCKET_STOP_PRE_SIGKILL)) socket_enter_stop_post(s, SOCKET_FAILURE_RESOURCES); else socket_enter_dead(s, SOCKET_FAILURE_RESOURCES); } static void socket_enter_stop_pre(Socket *s, SocketResult f) { int r; assert(s); if (s->result == SOCKET_SUCCESS) s->result = f; socket_unwatch_control_pid(s); s->control_command_id = SOCKET_EXEC_STOP_PRE; s->control_command = s->exec_command[SOCKET_EXEC_STOP_PRE]; if (s->control_command) { r = socket_spawn(s, s->control_command, &s->control_pid); if (r < 0) goto fail; socket_set_state(s, SOCKET_STOP_PRE); } else socket_enter_stop_post(s, SOCKET_SUCCESS); return; fail: log_unit_warning_errno(UNIT(s), r, "Failed to run 'stop-pre' task: %m"); socket_enter_stop_post(s, SOCKET_FAILURE_RESOURCES); } static void socket_enter_listening(Socket *s) { int r; assert(s); if (!s->accept && s->flush_pending) { log_unit_debug(UNIT(s), "Flushing socket before listening."); flush_ports(s); } r = socket_watch_fds(s); if (r < 0) { log_unit_warning_errno(UNIT(s), r, "Failed to watch sockets: %m"); goto fail; } socket_set_state(s, SOCKET_LISTENING); return; fail: socket_enter_stop_pre(s, SOCKET_FAILURE_RESOURCES); } static void socket_enter_start_post(Socket *s) { int r; assert(s); socket_unwatch_control_pid(s); s->control_command_id = SOCKET_EXEC_START_POST; s->control_command = s->exec_command[SOCKET_EXEC_START_POST]; if (s->control_command) { r = socket_spawn(s, s->control_command, &s->control_pid); if (r < 0) { log_unit_warning_errno(UNIT(s), r, "Failed to run 'start-post' task: %m"); goto fail; } socket_set_state(s, SOCKET_START_POST); } else socket_enter_listening(s); return; fail: socket_enter_stop_pre(s, SOCKET_FAILURE_RESOURCES); } static void socket_enter_start_chown(Socket *s) { int r; assert(s); r = socket_open_fds(s); if (r < 0) { log_unit_warning_errno(UNIT(s), r, "Failed to listen on sockets: %m"); goto fail; } if (!isempty(s->user) || !isempty(s->group)) { socket_unwatch_control_pid(s); s->control_command_id = SOCKET_EXEC_START_CHOWN; s->control_command = NULL; r = socket_chown(s, &s->control_pid); if (r < 0) { log_unit_warning_errno(UNIT(s), r, "Failed to fork 'start-chown' task: %m"); goto fail; } socket_set_state(s, SOCKET_START_CHOWN); } else socket_enter_start_post(s); return; fail: socket_enter_stop_pre(s, SOCKET_FAILURE_RESOURCES); } static void socket_enter_start_pre(Socket *s) { int r; assert(s); socket_unwatch_control_pid(s); unit_warn_leftover_processes(UNIT(s), unit_log_leftover_process_start); s->control_command_id = SOCKET_EXEC_START_PRE; s->control_command = s->exec_command[SOCKET_EXEC_START_PRE]; if (s->control_command) { r = socket_spawn(s, s->control_command, &s->control_pid); if (r < 0) { log_unit_warning_errno(UNIT(s), r, "Failed to run 'start-pre' task: %m"); goto fail; } socket_set_state(s, SOCKET_START_PRE); } else socket_enter_start_chown(s); return; fail: socket_enter_dead(s, SOCKET_FAILURE_RESOURCES); } static void flush_ports(Socket *s) { assert(s); /* Flush all incoming traffic, regardless if actual bytes or new connections, so that this socket isn't busy * anymore */ LIST_FOREACH(port, p, s->ports) { if (p->fd < 0) continue; (void) flush_accept(p->fd); (void) flush_fd(p->fd); } } static void socket_enter_running(Socket *s, int cfd_in) { /* Note that this call takes possession of the connection fd passed. It either has to assign it * somewhere or close it. */ _cleanup_close_ int cfd = cfd_in; _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; int r; assert(s); /* We don't take connections anymore if we are supposed to shut down anyway */ if (unit_stop_pending(UNIT(s))) { log_unit_debug(UNIT(s), "Suppressing connection request since unit stop is scheduled."); if (cfd >= 0) goto refuse; flush_ports(s); return; } if (!ratelimit_below(&s->trigger_limit)) { log_unit_warning(UNIT(s), "Trigger limit hit, refusing further activation."); socket_enter_stop_pre(s, SOCKET_FAILURE_TRIGGER_LIMIT_HIT); goto refuse; } if (cfd < 0) { bool pending = false; Unit *other; /* If there's already a start pending don't bother to do anything */ UNIT_FOREACH_DEPENDENCY(other, UNIT(s), UNIT_ATOM_TRIGGERS) if (unit_active_or_pending(other)) { pending = true; break; } if (!pending) { if (!UNIT_ISSET(s->service)) { r = log_unit_error_errno(UNIT(s), SYNTHETIC_ERRNO(ENOENT), "Service to activate vanished, refusing activation."); goto fail; } r = manager_add_job(UNIT(s)->manager, JOB_START, UNIT_DEREF(s->service), JOB_REPLACE, NULL, &error, NULL); if (r < 0) goto fail; } socket_set_state(s, SOCKET_RUNNING); } else { _cleanup_(socket_peer_unrefp) SocketPeer *p = NULL; Unit *service; if (s->n_connections >= s->max_connections) { log_unit_warning(UNIT(s), "Too many incoming connections (%u), dropping connection.", s->n_connections); goto refuse; } if (s->max_connections_per_source > 0) { r = socket_acquire_peer(s, cfd, &p); if (ERRNO_IS_DISCONNECT(r)) return; if (r < 0) /* We didn't have enough resources to acquire peer information, let's fail. */ goto fail; if (r > 0 && p->n_ref > s->max_connections_per_source) { _cleanup_free_ char *t = NULL; (void) sockaddr_pretty(&p->peer.sa, p->peer_salen, true, false, &t); log_unit_warning(UNIT(s), "Too many incoming connections (%u) from source %s, dropping connection.", p->n_ref, strnull(t)); goto refuse; } } r = socket_load_service_unit(s, cfd, &service); if (ERRNO_IS_DISCONNECT(r)) return; if (r < 0) goto fail; r = unit_add_two_dependencies(UNIT(s), UNIT_BEFORE, UNIT_TRIGGERS, service, false, UNIT_DEPENDENCY_IMPLICIT); if (r < 0) goto fail; s->n_accepted++; r = service_set_socket_fd(SERVICE(service), cfd, s, p, s->selinux_context_from_net); if (ERRNO_IS_DISCONNECT(r)) return; if (r < 0) goto fail; TAKE_FD(cfd); /* We passed ownership of the fd to the service now. Forget it here. */ s->n_connections++; r = manager_add_job(UNIT(s)->manager, JOB_START, service, JOB_REPLACE, NULL, &error, NULL); if (r < 0) { /* We failed to activate the new service, but it still exists. Let's make sure the * service closes and forgets the connection fd again, immediately. */ service_close_socket_fd(SERVICE(service)); goto fail; } /* Notify clients about changed counters */ unit_add_to_dbus_queue(UNIT(s)); } TAKE_FD(cfd); return; refuse: s->n_refused++; return; fail: if (ERRNO_IS_RESOURCE(r)) log_unit_warning(UNIT(s), "Failed to queue service startup job: %s", bus_error_message(&error, r)); else log_unit_warning(UNIT(s), "Failed to queue service startup job (Maybe the service file is missing or not a %s unit?): %s", cfd >= 0 ? "template" : "non-template", bus_error_message(&error, r)); socket_enter_stop_pre(s, SOCKET_FAILURE_RESOURCES); } static void socket_run_next(Socket *s) { int r; assert(s); assert(s->control_command); assert(s->control_command->command_next); socket_unwatch_control_pid(s); s->control_command = s->control_command->command_next; r = socket_spawn(s, s->control_command, &s->control_pid); if (r < 0) goto fail; return; fail: log_unit_warning_errno(UNIT(s), r, "Failed to run next task: %m"); if (s->state == SOCKET_START_POST) socket_enter_stop_pre(s, SOCKET_FAILURE_RESOURCES); else if (s->state == SOCKET_STOP_POST) socket_enter_dead(s, SOCKET_FAILURE_RESOURCES); else socket_enter_signal(s, SOCKET_FINAL_SIGTERM, SOCKET_FAILURE_RESOURCES); } static int socket_start(Unit *u) { Socket *s = SOCKET(u); int r; assert(s); /* We cannot fulfill this request right now, try again later * please! */ if (IN_SET(s->state, SOCKET_STOP_PRE, SOCKET_STOP_PRE_SIGKILL, SOCKET_STOP_PRE_SIGTERM, SOCKET_STOP_POST, SOCKET_FINAL_SIGTERM, SOCKET_FINAL_SIGKILL, SOCKET_CLEANING)) return -EAGAIN; /* Already on it! */ if (IN_SET(s->state, SOCKET_START_PRE, SOCKET_START_CHOWN, SOCKET_START_POST)) return 0; /* Cannot run this without the service being around */ if (UNIT_ISSET(s->service)) { Service *service; service = SERVICE(UNIT_DEREF(s->service)); if (UNIT(service)->load_state != UNIT_LOADED) return log_unit_error_errno(u, SYNTHETIC_ERRNO(ENOENT), "Socket service %s not loaded, refusing.", UNIT(service)->id); /* If the service is already active we cannot start the * socket */ if (!IN_SET(service->state, SERVICE_DEAD, SERVICE_FAILED, SERVICE_AUTO_RESTART)) return log_unit_error_errno(u, SYNTHETIC_ERRNO(EBUSY), "Socket service %s already active, refusing.", UNIT(service)->id); } assert(IN_SET(s->state, SOCKET_DEAD, SOCKET_FAILED)); r = unit_acquire_invocation_id(u); if (r < 0) return r; s->result = SOCKET_SUCCESS; exec_command_reset_status_list_array(s->exec_command, _SOCKET_EXEC_COMMAND_MAX); u->reset_accounting = true; socket_enter_start_pre(s); return 1; } static int socket_stop(Unit *u) { Socket *s = SOCKET(u); assert(s); /* Already on it */ if (IN_SET(s->state, SOCKET_STOP_PRE, SOCKET_STOP_PRE_SIGTERM, SOCKET_STOP_PRE_SIGKILL, SOCKET_STOP_POST, SOCKET_FINAL_SIGTERM, SOCKET_FINAL_SIGKILL)) return 0; /* If there's already something running we go directly into * kill mode. */ if (IN_SET(s->state, SOCKET_START_PRE, SOCKET_START_CHOWN, SOCKET_START_POST)) { socket_enter_signal(s, SOCKET_STOP_PRE_SIGTERM, SOCKET_SUCCESS); return -EAGAIN; } /* If we are currently cleaning, then abort it, brutally. */ if (s->state == SOCKET_CLEANING) { socket_enter_signal(s, SOCKET_FINAL_SIGKILL, SOCKET_SUCCESS); return 0; } assert(IN_SET(s->state, SOCKET_LISTENING, SOCKET_RUNNING)); socket_enter_stop_pre(s, SOCKET_SUCCESS); return 1; } static int socket_serialize(Unit *u, FILE *f, FDSet *fds) { Socket *s = SOCKET(u); int r; assert(u); assert(f); assert(fds); (void) serialize_item(f, "state", socket_state_to_string(s->state)); (void) serialize_item(f, "result", socket_result_to_string(s->result)); (void) serialize_item_format(f, "n-accepted", "%u", s->n_accepted); (void) serialize_item_format(f, "n-refused", "%u", s->n_refused); if (s->control_pid > 0) (void) serialize_item_format(f, "control-pid", PID_FMT, s->control_pid); if (s->control_command_id >= 0) (void) serialize_item(f, "control-command", socket_exec_command_to_string(s->control_command_id)); LIST_FOREACH(port, p, s->ports) { int copy; if (p->fd < 0) continue; copy = fdset_put_dup(fds, p->fd); if (copy < 0) return log_unit_warning_errno(u, copy, "Failed to serialize socket fd: %m"); if (p->type == SOCKET_SOCKET) { _cleanup_free_ char *t = NULL; r = socket_address_print(&p->address, &t); if (r < 0) return log_unit_error_errno(u, r, "Failed to format socket address: %m"); if (socket_address_family(&p->address) == AF_NETLINK) (void) serialize_item_format(f, "netlink", "%i %s", copy, t); else (void) serialize_item_format(f, "socket", "%i %i %s", copy, p->address.type, t); } else if (p->type == SOCKET_SPECIAL) (void) serialize_item_format(f, "special", "%i %s", copy, p->path); else if (p->type == SOCKET_MQUEUE) (void) serialize_item_format(f, "mqueue", "%i %s", copy, p->path); else if (p->type == SOCKET_USB_FUNCTION) (void) serialize_item_format(f, "ffs", "%i %s", copy, p->path); else { assert(p->type == SOCKET_FIFO); (void) serialize_item_format(f, "fifo", "%i %s", copy, p->path); } } return 0; } static int socket_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) { Socket *s = SOCKET(u); assert(u); assert(key); assert(value); if (streq(key, "state")) { SocketState state; state = socket_state_from_string(value); if (state < 0) log_unit_debug(u, "Failed to parse state value: %s", value); else s->deserialized_state = state; } else if (streq(key, "result")) { SocketResult f; f = socket_result_from_string(value); if (f < 0) log_unit_debug(u, "Failed to parse result value: %s", value); else if (f != SOCKET_SUCCESS) s->result = f; } else if (streq(key, "n-accepted")) { unsigned k; if (safe_atou(value, &k) < 0) log_unit_debug(u, "Failed to parse n-accepted value: %s", value); else s->n_accepted += k; } else if (streq(key, "n-refused")) { unsigned k; if (safe_atou(value, &k) < 0) log_unit_debug(u, "Failed to parse n-refused value: %s", value); else s->n_refused += k; } else if (streq(key, "control-pid")) { pid_t pid; if (parse_pid(value, &pid) < 0) log_unit_debug(u, "Failed to parse control-pid value: %s", value); else s->control_pid = pid; } else if (streq(key, "control-command")) { SocketExecCommand id; id = socket_exec_command_from_string(value); if (id < 0) log_unit_debug(u, "Failed to parse exec-command value: %s", value); else { s->control_command_id = id; s->control_command = s->exec_command[id]; } } else if (streq(key, "fifo")) { int fd, skip = 0; if (sscanf(value, "%i %n", &fd, &skip) < 1 || fd < 0 || !fdset_contains(fds, fd)) log_unit_debug(u, "Failed to parse fifo value: %s", value); else { bool found = false; LIST_FOREACH(port, p, s->ports) if (p->fd < 0 && p->type == SOCKET_FIFO && path_equal_or_files_same(p->path, value+skip, 0)) { p->fd = fdset_remove(fds, fd); found = true; break; } if (!found) log_unit_debug(u, "No matching fifo socket found: %s", value+skip); } } else if (streq(key, "special")) { int fd, skip = 0; if (sscanf(value, "%i %n", &fd, &skip) < 1 || fd < 0 || !fdset_contains(fds, fd)) log_unit_debug(u, "Failed to parse special value: %s", value); else { bool found = false; LIST_FOREACH(port, p, s->ports) if (p->fd < 0 && p->type == SOCKET_SPECIAL && path_equal_or_files_same(p->path, value+skip, 0)) { p->fd = fdset_remove(fds, fd); found = true; break; } if (!found) log_unit_debug(u, "No matching special socket found: %s", value+skip); } } else if (streq(key, "mqueue")) { int fd, skip = 0; if (sscanf(value, "%i %n", &fd, &skip) < 1 || fd < 0 || !fdset_contains(fds, fd)) log_unit_debug(u, "Failed to parse mqueue value: %s", value); else { bool found = false; LIST_FOREACH(port, p, s->ports) if (p->fd < 0 && p->type == SOCKET_MQUEUE && streq(p->path, value+skip)) { p->fd = fdset_remove(fds, fd); found = true; break; } if (!found) log_unit_debug(u, "No matching mqueue socket found: %s", value+skip); } } else if (streq(key, "socket")) { int fd, type, skip = 0; if (sscanf(value, "%i %i %n", &fd, &type, &skip) < 2 || fd < 0 || type < 0 || !fdset_contains(fds, fd)) log_unit_debug(u, "Failed to parse socket value: %s", value); else { bool found = false; LIST_FOREACH(port, p, s->ports) if (p->fd < 0 && socket_address_is(&p->address, value+skip, type)) { p->fd = fdset_remove(fds, fd); found = true; break; } if (!found) log_unit_debug(u, "No matching %s socket found: %s", socket_address_type_to_string(type), value+skip); } } else if (streq(key, "netlink")) { int fd, skip = 0; if (sscanf(value, "%i %n", &fd, &skip) < 1 || fd < 0 || !fdset_contains(fds, fd)) log_unit_debug(u, "Failed to parse socket value: %s", value); else { bool found = false; LIST_FOREACH(port, p, s->ports) if (p->fd < 0 && socket_address_is_netlink(&p->address, value+skip)) { p->fd = fdset_remove(fds, fd); found = true; break; } if (!found) log_unit_debug(u, "No matching netlink socket found: %s", value+skip); } } else if (streq(key, "ffs")) { int fd, skip = 0; if (sscanf(value, "%i %n", &fd, &skip) < 1 || fd < 0 || !fdset_contains(fds, fd)) log_unit_debug(u, "Failed to parse ffs value: %s", value); else { bool found = false; LIST_FOREACH(port, p, s->ports) if (p->fd < 0 && p->type == SOCKET_USB_FUNCTION && path_equal_or_files_same(p->path, value+skip, 0)) { p->fd = fdset_remove(fds, fd); found = true; break; } if (!found) log_unit_debug(u, "No matching ffs socket found: %s", value+skip); } } else log_unit_debug(UNIT(s), "Unknown serialization key: %s", key); return 0; } static void socket_distribute_fds(Unit *u, FDSet *fds) { Socket *s = SOCKET(u); assert(u); LIST_FOREACH(port, p, s->ports) { int fd; if (p->type != SOCKET_SOCKET) continue; if (p->fd >= 0) continue; FDSET_FOREACH(fd, fds) { if (socket_address_matches_fd(&p->address, fd)) { p->fd = fdset_remove(fds, fd); s->deserialized_state = SOCKET_LISTENING; break; } } } } _pure_ static UnitActiveState socket_active_state(Unit *u) { assert(u); return state_translation_table[SOCKET(u)->state]; } _pure_ static const char *socket_sub_state_to_string(Unit *u) { assert(u); return socket_state_to_string(SOCKET(u)->state); } const char* socket_port_type_to_string(SocketPort *p) { assert(p); switch (p->type) { case SOCKET_SOCKET: switch (p->address.type) { case SOCK_STREAM: return "Stream"; case SOCK_DGRAM: return "Datagram"; case SOCK_SEQPACKET: return "SequentialPacket"; case SOCK_RAW: if (socket_address_family(&p->address) == AF_NETLINK) return "Netlink"; _fallthrough_; default: return NULL; } case SOCKET_SPECIAL: return "Special"; case SOCKET_MQUEUE: return "MessageQueue"; case SOCKET_FIFO: return "FIFO"; case SOCKET_USB_FUNCTION: return "USBFunction"; default: return NULL; } } SocketType socket_port_type_from_string(const char *s) { assert(s); if (STR_IN_SET(s, "Stream", "Datagram", "SequentialPacket", "Netlink")) return SOCKET_SOCKET; else if (streq(s, "Special")) return SOCKET_SPECIAL; else if (streq(s, "MessageQueue")) return SOCKET_MQUEUE; else if (streq(s, "FIFO")) return SOCKET_FIFO; else if (streq(s, "USBFunction")) return SOCKET_USB_FUNCTION; else return _SOCKET_TYPE_INVALID; } _pure_ static bool socket_may_gc(Unit *u) { Socket *s = SOCKET(u); assert(u); return s->n_connections == 0; } static int socket_accept_do(Socket *s, int fd) { int cfd; assert(s); assert(fd >= 0); cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC); if (cfd < 0) /* Convert transient network errors into clean and well-defined EAGAIN */ return ERRNO_IS_ACCEPT_AGAIN(errno) ? -EAGAIN : -errno; return cfd; } static int socket_accept_in_cgroup(Socket *s, SocketPort *p, int fd) { _cleanup_close_pair_ int pair[2] = { -1, -1 }; int cfd, r; pid_t pid; assert(s); assert(p); assert(fd >= 0); /* Similar to socket_address_listen_in_cgroup(), but for accept() rather than socket(): make sure that any * connection socket is also properly associated with the cgroup. */ if (!IN_SET(p->address.sockaddr.sa.sa_family, AF_INET, AF_INET6)) goto shortcut; r = bpf_firewall_supported(); if (r < 0) return r; if (r == BPF_FIREWALL_UNSUPPORTED) goto shortcut; if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, pair) < 0) return log_unit_error_errno(UNIT(s), errno, "Failed to create communication channel: %m"); r = unit_fork_helper_process(UNIT(s), "(sd-accept)", &pid); if (r < 0) return log_unit_error_errno(UNIT(s), r, "Failed to fork off accept stub process: %m"); if (r == 0) { /* Child */ pair[0] = safe_close(pair[0]); cfd = socket_accept_do(s, fd); if (cfd == -EAGAIN) /* spurious accept() */ _exit(EXIT_SUCCESS); if (cfd < 0) { log_unit_error_errno(UNIT(s), cfd, "Failed to accept connection socket: %m"); _exit(EXIT_FAILURE); } r = send_one_fd(pair[1], cfd, 0); if (r < 0) { log_unit_error_errno(UNIT(s), r, "Failed to send connection socket to parent: %m"); _exit(EXIT_FAILURE); } _exit(EXIT_SUCCESS); } pair[1] = safe_close(pair[1]); cfd = receive_one_fd(pair[0], 0); /* We synchronously wait for the helper, as it shouldn't be slow */ r = wait_for_terminate_and_check("(sd-accept)", pid, WAIT_LOG_ABNORMAL); if (r < 0) { safe_close(cfd); return r; } /* If we received no fd, we got EIO here. If this happens with a process exit code of EXIT_SUCCESS * this is a spurious accept(), let's convert that back to EAGAIN here. */ if (cfd == -EIO) return -EAGAIN; if (cfd < 0) return log_unit_error_errno(UNIT(s), cfd, "Failed to receive connection socket: %m"); return cfd; shortcut: cfd = socket_accept_do(s, fd); if (cfd == -EAGAIN) /* spurious accept(), skip it silently */ return -EAGAIN; if (cfd < 0) return log_unit_error_errno(UNIT(s), cfd, "Failed to accept connection socket: %m"); return cfd; } static int socket_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) { SocketPort *p = userdata; int cfd = -1; assert(p); assert(fd >= 0); if (p->socket->state != SOCKET_LISTENING) return 0; log_unit_debug(UNIT(p->socket), "Incoming traffic"); if (revents != EPOLLIN) { if (revents & EPOLLHUP) log_unit_error(UNIT(p->socket), "Got POLLHUP on a listening socket. The service probably invoked shutdown() on it, and should better not do that."); else log_unit_error(UNIT(p->socket), "Got unexpected poll event (0x%x) on socket.", revents); goto fail; } if (p->socket->accept && p->type == SOCKET_SOCKET && socket_address_can_accept(&p->address)) { cfd = socket_accept_in_cgroup(p->socket, p, fd); if (cfd == -EAGAIN) /* Spurious accept() */ return 0; if (cfd < 0) goto fail; socket_apply_socket_options(p->socket, p, cfd); } socket_enter_running(p->socket, cfd); return 0; fail: socket_enter_stop_pre(p->socket, SOCKET_FAILURE_RESOURCES); return 0; } static void socket_sigchld_event(Unit *u, pid_t pid, int code, int status) { Socket *s = SOCKET(u); SocketResult f; assert(s); assert(pid >= 0); if (pid != s->control_pid) return; s->control_pid = 0; if (is_clean_exit(code, status, EXIT_CLEAN_COMMAND, NULL)) f = SOCKET_SUCCESS; else if (code == CLD_EXITED) f = SOCKET_FAILURE_EXIT_CODE; else if (code == CLD_KILLED) f = SOCKET_FAILURE_SIGNAL; else if (code == CLD_DUMPED) f = SOCKET_FAILURE_CORE_DUMP; else assert_not_reached(); if (s->control_command) { exec_status_exit(&s->control_command->exec_status, &s->exec_context, pid, code, status); if (s->control_command->flags & EXEC_COMMAND_IGNORE_FAILURE) f = SOCKET_SUCCESS; } unit_log_process_exit( u, "Control process", socket_exec_command_to_string(s->control_command_id), f == SOCKET_SUCCESS, code, status); if (s->result == SOCKET_SUCCESS) s->result = f; if (s->control_command && s->control_command->command_next && f == SOCKET_SUCCESS) { log_unit_debug(u, "Running next command for state %s", socket_state_to_string(s->state)); socket_run_next(s); } else { s->control_command = NULL; s->control_command_id = _SOCKET_EXEC_COMMAND_INVALID; /* No further commands for this step, so let's figure * out what to do next */ log_unit_debug(u, "Got final SIGCHLD for state %s", socket_state_to_string(s->state)); switch (s->state) { case SOCKET_START_PRE: if (f == SOCKET_SUCCESS) socket_enter_start_chown(s); else socket_enter_signal(s, SOCKET_FINAL_SIGTERM, f); break; case SOCKET_START_CHOWN: if (f == SOCKET_SUCCESS) socket_enter_start_post(s); else socket_enter_stop_pre(s, f); break; case SOCKET_START_POST: if (f == SOCKET_SUCCESS) socket_enter_listening(s); else socket_enter_stop_pre(s, f); break; case SOCKET_STOP_PRE: case SOCKET_STOP_PRE_SIGTERM: case SOCKET_STOP_PRE_SIGKILL: socket_enter_stop_post(s, f); break; case SOCKET_STOP_POST: case SOCKET_FINAL_SIGTERM: case SOCKET_FINAL_SIGKILL: socket_enter_dead(s, f); break; case SOCKET_CLEANING: if (s->clean_result == SOCKET_SUCCESS) s->clean_result = f; socket_enter_dead(s, SOCKET_SUCCESS); break; default: assert_not_reached(); } } /* Notify clients about changed exit status */ unit_add_to_dbus_queue(u); } static int socket_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) { Socket *s = SOCKET(userdata); assert(s); assert(s->timer_event_source == source); switch (s->state) { case SOCKET_START_PRE: log_unit_warning(UNIT(s), "Starting timed out. Terminating."); socket_enter_signal(s, SOCKET_FINAL_SIGTERM, SOCKET_FAILURE_TIMEOUT); break; case SOCKET_START_CHOWN: case SOCKET_START_POST: log_unit_warning(UNIT(s), "Starting timed out. Stopping."); socket_enter_stop_pre(s, SOCKET_FAILURE_TIMEOUT); break; case SOCKET_STOP_PRE: log_unit_warning(UNIT(s), "Stopping timed out. Terminating."); socket_enter_signal(s, SOCKET_STOP_PRE_SIGTERM, SOCKET_FAILURE_TIMEOUT); break; case SOCKET_STOP_PRE_SIGTERM: if (s->kill_context.send_sigkill) { log_unit_warning(UNIT(s), "Stopping timed out. Killing."); socket_enter_signal(s, SOCKET_STOP_PRE_SIGKILL, SOCKET_FAILURE_TIMEOUT); } else { log_unit_warning(UNIT(s), "Stopping timed out. Skipping SIGKILL. Ignoring."); socket_enter_stop_post(s, SOCKET_FAILURE_TIMEOUT); } break; case SOCKET_STOP_PRE_SIGKILL: log_unit_warning(UNIT(s), "Processes still around after SIGKILL. Ignoring."); socket_enter_stop_post(s, SOCKET_FAILURE_TIMEOUT); break; case SOCKET_STOP_POST: log_unit_warning(UNIT(s), "Stopping timed out (2). Terminating."); socket_enter_signal(s, SOCKET_FINAL_SIGTERM, SOCKET_FAILURE_TIMEOUT); break; case SOCKET_FINAL_SIGTERM: if (s->kill_context.send_sigkill) { log_unit_warning(UNIT(s), "Stopping timed out (2). Killing."); socket_enter_signal(s, SOCKET_FINAL_SIGKILL, SOCKET_FAILURE_TIMEOUT); } else { log_unit_warning(UNIT(s), "Stopping timed out (2). Skipping SIGKILL. Ignoring."); socket_enter_dead(s, SOCKET_FAILURE_TIMEOUT); } break; case SOCKET_FINAL_SIGKILL: log_unit_warning(UNIT(s), "Still around after SIGKILL (2). Entering failed mode."); socket_enter_dead(s, SOCKET_FAILURE_TIMEOUT); break; case SOCKET_CLEANING: log_unit_warning(UNIT(s), "Cleaning timed out. killing."); if (s->clean_result == SOCKET_SUCCESS) s->clean_result = SOCKET_FAILURE_TIMEOUT; socket_enter_signal(s, SOCKET_FINAL_SIGKILL, 0); break; default: assert_not_reached(); } return 0; } int socket_collect_fds(Socket *s, int **fds) { size_t k = 0, n = 0; int *rfds; assert(s); assert(fds); /* Called from the service code for requesting our fds */ LIST_FOREACH(port, p, s->ports) { if (p->fd >= 0) n++; n += p->n_auxiliary_fds; } if (n <= 0) { *fds = NULL; return 0; } rfds = new(int, n); if (!rfds) return -ENOMEM; LIST_FOREACH(port, p, s->ports) { if (p->fd >= 0) rfds[k++] = p->fd; for (size_t i = 0; i < p->n_auxiliary_fds; ++i) rfds[k++] = p->auxiliary_fds[i]; } assert(k == n); *fds = rfds; return (int) n; } static void socket_reset_failed(Unit *u) { Socket *s = SOCKET(u); assert(s); if (s->state == SOCKET_FAILED) socket_set_state(s, SOCKET_DEAD); s->result = SOCKET_SUCCESS; s->clean_result = SOCKET_SUCCESS; } void socket_connection_unref(Socket *s) { assert(s); /* The service is dead. Yay! * * This is strictly for one-instance-per-connection * services. */ assert(s->n_connections > 0); s->n_connections--; log_unit_debug(UNIT(s), "One connection closed, %u left.", s->n_connections); } static void socket_trigger_notify(Unit *u, Unit *other) { Socket *s = SOCKET(u); assert(u); assert(other); /* Filter out invocations with bogus state */ assert(UNIT_IS_LOAD_COMPLETE(other->load_state)); assert(other->type == UNIT_SERVICE); /* Don't propagate state changes from the service if we are already down */ if (!IN_SET(s->state, SOCKET_RUNNING, SOCKET_LISTENING)) return; /* We don't care for the service state if we are in Accept=yes mode */ if (s->accept) return; /* Propagate start limit hit state */ if (other->start_limit_hit) { socket_enter_stop_pre(s, SOCKET_FAILURE_SERVICE_START_LIMIT_HIT); return; } /* Don't propagate anything if there's still a job queued */ if (other->job) return; if (IN_SET(SERVICE(other)->state, SERVICE_DEAD, SERVICE_FAILED, SERVICE_FINAL_SIGTERM, SERVICE_FINAL_SIGKILL, SERVICE_AUTO_RESTART)) socket_enter_listening(s); if (SERVICE(other)->state == SERVICE_RUNNING) socket_set_state(s, SOCKET_RUNNING); } static int socket_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) { return unit_kill_common(u, who, signo, -1, SOCKET(u)->control_pid, error); } static int socket_get_timeout(Unit *u, usec_t *timeout) { Socket *s = SOCKET(u); usec_t t; int r; if (!s->timer_event_source) return 0; r = sd_event_source_get_time(s->timer_event_source, &t); if (r < 0) return r; if (t == USEC_INFINITY) return 0; *timeout = t; return 1; } char *socket_fdname(Socket *s) { assert(s); /* Returns the name to use for $LISTEN_NAMES. If the user * didn't specify anything specifically, use the socket unit's * name as fallback. */ return s->fdname ?: UNIT(s)->id; } static int socket_control_pid(Unit *u) { Socket *s = SOCKET(u); assert(s); return s->control_pid; } static int socket_clean(Unit *u, ExecCleanMask mask) { _cleanup_strv_free_ char **l = NULL; Socket *s = SOCKET(u); int r; assert(s); assert(mask != 0); if (s->state != SOCKET_DEAD) return -EBUSY; r = exec_context_get_clean_directories(&s->exec_context, u->manager->prefix, mask, &l); if (r < 0) return r; if (strv_isempty(l)) return -EUNATCH; socket_unwatch_control_pid(s); s->clean_result = SOCKET_SUCCESS; s->control_command = NULL; s->control_command_id = _SOCKET_EXEC_COMMAND_INVALID; r = socket_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->exec_context.timeout_clean_usec)); if (r < 0) goto fail; r = unit_fork_and_watch_rm_rf(u, l, &s->control_pid); if (r < 0) goto fail; socket_set_state(s, SOCKET_CLEANING); return 0; fail: log_unit_warning_errno(u, r, "Failed to initiate cleaning: %m"); s->clean_result = SOCKET_FAILURE_RESOURCES; s->timer_event_source = sd_event_source_disable_unref(s->timer_event_source); return r; } static int socket_can_clean(Unit *u, ExecCleanMask *ret) { Socket *s = SOCKET(u); assert(s); return exec_context_get_clean_mask(&s->exec_context, ret); } static int socket_can_start(Unit *u) { Socket *s = SOCKET(u); int r; assert(s); r = unit_test_start_limit(u); if (r < 0) { socket_enter_dead(s, SOCKET_FAILURE_START_LIMIT_HIT); return r; } return 1; } static const char* const socket_exec_command_table[_SOCKET_EXEC_COMMAND_MAX] = { [SOCKET_EXEC_START_PRE] = "ExecStartPre", [SOCKET_EXEC_START_CHOWN] = "ExecStartChown", [SOCKET_EXEC_START_POST] = "ExecStartPost", [SOCKET_EXEC_STOP_PRE] = "ExecStopPre", [SOCKET_EXEC_STOP_POST] = "ExecStopPost" }; DEFINE_STRING_TABLE_LOOKUP(socket_exec_command, SocketExecCommand); static const char* const socket_result_table[_SOCKET_RESULT_MAX] = { [SOCKET_SUCCESS] = "success", [SOCKET_FAILURE_RESOURCES] = "resources", [SOCKET_FAILURE_TIMEOUT] = "timeout", [SOCKET_FAILURE_EXIT_CODE] = "exit-code", [SOCKET_FAILURE_SIGNAL] = "signal", [SOCKET_FAILURE_CORE_DUMP] = "core-dump", [SOCKET_FAILURE_START_LIMIT_HIT] = "start-limit-hit", [SOCKET_FAILURE_TRIGGER_LIMIT_HIT] = "trigger-limit-hit", [SOCKET_FAILURE_SERVICE_START_LIMIT_HIT] = "service-start-limit-hit" }; DEFINE_STRING_TABLE_LOOKUP(socket_result, SocketResult); static const char* const socket_timestamping_table[_SOCKET_TIMESTAMPING_MAX] = { [SOCKET_TIMESTAMPING_OFF] = "off", [SOCKET_TIMESTAMPING_US] = "us", [SOCKET_TIMESTAMPING_NS] = "ns", }; DEFINE_STRING_TABLE_LOOKUP(socket_timestamping, SocketTimestamping); SocketTimestamping socket_timestamping_from_string_harder(const char *p) { SocketTimestamping t; int r; if (!p) return _SOCKET_TIMESTAMPING_INVALID; t = socket_timestamping_from_string(p); if (t >= 0) return t; /* Let's alternatively support the various other aliases parse_time() accepts for ns and µs here, * too. */ if (streq(p, "nsec")) return SOCKET_TIMESTAMPING_NS; if (STR_IN_SET(p, "usec", "µs")) return SOCKET_TIMESTAMPING_US; r = parse_boolean(p); if (r < 0) return _SOCKET_TIMESTAMPING_INVALID; return r ? SOCKET_TIMESTAMPING_NS : SOCKET_TIMESTAMPING_OFF; /* If boolean yes, default to ns accuracy */ } const UnitVTable socket_vtable = { .object_size = sizeof(Socket), .exec_context_offset = offsetof(Socket, exec_context), .cgroup_context_offset = offsetof(Socket, cgroup_context), .kill_context_offset = offsetof(Socket, kill_context), .exec_runtime_offset = offsetof(Socket, exec_runtime), .dynamic_creds_offset = offsetof(Socket, dynamic_creds), .sections = "Unit\0" "Socket\0" "Install\0", .private_section = "Socket", .can_transient = true, .can_trigger = true, .can_fail = true, .init = socket_init, .done = socket_done, .load = socket_load, .coldplug = socket_coldplug, .dump = socket_dump, .start = socket_start, .stop = socket_stop, .kill = socket_kill, .clean = socket_clean, .can_clean = socket_can_clean, .get_timeout = socket_get_timeout, .serialize = socket_serialize, .deserialize_item = socket_deserialize_item, .distribute_fds = socket_distribute_fds, .active_state = socket_active_state, .sub_state_to_string = socket_sub_state_to_string, .will_restart = unit_will_restart_default, .may_gc = socket_may_gc, .sigchld_event = socket_sigchld_event, .trigger_notify = socket_trigger_notify, .reset_failed = socket_reset_failed, .control_pid = socket_control_pid, .bus_set_property = bus_socket_set_property, .bus_commit_properties = bus_socket_commit_properties, .status_message_formats = { .finished_start_job = { [JOB_DONE] = "Listening on %s.", [JOB_FAILED] = "Failed to listen on %s.", [JOB_TIMEOUT] = "Timed out starting %s.", }, .finished_stop_job = { [JOB_DONE] = "Closed %s.", [JOB_FAILED] = "Failed stopping %s.", [JOB_TIMEOUT] = "Timed out stopping %s.", }, }, .can_start = socket_can_start, };