/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <errno.h> #include <limits.h> #include <sys/mount.h> #include <unistd.h> #include <fcntl.h> #include <sys/epoll.h> #include <sys/stat.h> #include <linux/auto_fs4.h> #include <linux/auto_dev-ioctl.h> #include "unit.h" #include "automount.h" #include "mount.h" #include "load-fragment.h" #include "load-dropin.h" #include "unit-name.h" #include "special.h" #include "label.h" #include "mkdir.h" #include "path-util.h" #include "dbus-automount.h" #include "bus-util.h" #include "bus-error.h" static const UnitActiveState state_translation_table[_AUTOMOUNT_STATE_MAX] = { [AUTOMOUNT_DEAD] = UNIT_INACTIVE, [AUTOMOUNT_WAITING] = UNIT_ACTIVE, [AUTOMOUNT_RUNNING] = UNIT_ACTIVE, [AUTOMOUNT_FAILED] = UNIT_FAILED }; static int open_dev_autofs(Manager *m); static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata); static void automount_init(Unit *u) { Automount *a = AUTOMOUNT(u); assert(u); assert(u->load_state == UNIT_STUB); a->pipe_fd = -1; a->directory_mode = 0755; UNIT(a)->ignore_on_isolate = true; } static void repeat_unmount(const char *path) { assert(path); for (;;) { /* If there are multiple mounts on a mount point, this * removes them all */ if (umount2(path, MNT_DETACH) >= 0) continue; if (errno != EINVAL) log_error("Failed to unmount: %m"); break; } } static void unmount_autofs(Automount *a) { assert(a); if (a->pipe_fd < 0) return; automount_send_ready(a, -EHOSTDOWN); a->pipe_event_source = sd_event_source_unref(a->pipe_event_source); a->pipe_fd = safe_close(a->pipe_fd); /* If we reload/reexecute things we keep the mount point * around */ if (a->where && (UNIT(a)->manager->exit_code != MANAGER_RELOAD && UNIT(a)->manager->exit_code != MANAGER_REEXECUTE)) repeat_unmount(a->where); } static void automount_done(Unit *u) { Automount *a = AUTOMOUNT(u); assert(a); unmount_autofs(a); free(a->where); a->where = NULL; set_free(a->tokens); a->tokens = NULL; } static int automount_add_mount_links(Automount *a) { _cleanup_free_ char *parent = NULL; int r; assert(a); r = path_get_parent(a->where, &parent); if (r < 0) return r; return unit_require_mounts_for(UNIT(a), parent); } static int automount_add_default_dependencies(Automount *a) { int r; assert(a); if (UNIT(a)->manager->running_as != SYSTEMD_SYSTEM) return 0; r = unit_add_two_dependencies_by_name(UNIT(a), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true); if (r < 0) return r; return 0; } static int automount_verify(Automount *a) { bool b; _cleanup_free_ char *e = NULL; assert(a); if (UNIT(a)->load_state != UNIT_LOADED) return 0; if (path_equal(a->where, "/")) { log_error_unit(UNIT(a)->id, "Cannot have an automount unit for the root directory. Refusing."); return -EINVAL; } e = unit_name_from_path(a->where, ".automount"); if (!e) return -ENOMEM; b = unit_has_name(UNIT(a), e); if (!b) { log_error_unit(UNIT(a)->id, "%s's Where setting doesn't match unit name. Refusing.", UNIT(a)->id); return -EINVAL; } return 0; } static int automount_load(Unit *u) { Automount *a = AUTOMOUNT(u); int r; assert(u); assert(u->load_state == UNIT_STUB); /* Load a .automount file */ r = unit_load_fragment_and_dropin_optional(u); if (r < 0) return r; if (u->load_state == UNIT_LOADED) { Unit *x; if (!a->where) { a->where = unit_name_to_path(u->id); if (!a->where) return -ENOMEM; } path_kill_slashes(a->where); r = unit_load_related_unit(u, ".mount", &x); if (r < 0) return r; r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, x, true); if (r < 0) return r; r = automount_add_mount_links(a); if (r < 0) return r; if (UNIT(a)->default_dependencies) { r = automount_add_default_dependencies(a); if (r < 0) return r; } } return automount_verify(a); } static void automount_set_state(Automount *a, AutomountState state) { AutomountState old_state; assert(a); old_state = a->state; a->state = state; if (state != AUTOMOUNT_WAITING && state != AUTOMOUNT_RUNNING) unmount_autofs(a); if (state != old_state) log_debug_unit(UNIT(a)->id, "%s changed %s -> %s", UNIT(a)->id, automount_state_to_string(old_state), automount_state_to_string(state)); unit_notify(UNIT(a), state_translation_table[old_state], state_translation_table[state], true); } static int automount_coldplug(Unit *u) { Automount *a = AUTOMOUNT(u); int r; assert(a); assert(a->state == AUTOMOUNT_DEAD); if (a->deserialized_state != a->state) { r = open_dev_autofs(u->manager); if (r < 0) return r; if (a->deserialized_state == AUTOMOUNT_WAITING || a->deserialized_state == AUTOMOUNT_RUNNING) { assert(a->pipe_fd >= 0); r = sd_event_add_io(u->manager->event, &a->pipe_event_source, a->pipe_fd, EPOLLIN, automount_dispatch_io, u); if (r < 0) return r; } automount_set_state(a, a->deserialized_state); } return 0; } static void automount_dump(Unit *u, FILE *f, const char *prefix) { Automount *a = AUTOMOUNT(u); assert(a); fprintf(f, "%sAutomount State: %s\n" "%sResult: %s\n" "%sWhere: %s\n" "%sDirectoryMode: %04o\n", prefix, automount_state_to_string(a->state), prefix, automount_result_to_string(a->result), prefix, a->where, prefix, a->directory_mode); } static void automount_enter_dead(Automount *a, AutomountResult f) { assert(a); if (f != AUTOMOUNT_SUCCESS) a->result = f; automount_set_state(a, a->result != AUTOMOUNT_SUCCESS ? AUTOMOUNT_FAILED : AUTOMOUNT_DEAD); } static int open_dev_autofs(Manager *m) { struct autofs_dev_ioctl param; assert(m); if (m->dev_autofs_fd >= 0) return m->dev_autofs_fd; label_fix("/dev/autofs", false, false); m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY); if (m->dev_autofs_fd < 0) { log_error("Failed to open /dev/autofs: %m"); return -errno; } init_autofs_dev_ioctl(¶m); if (ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, ¶m) < 0) { m->dev_autofs_fd = safe_close(m->dev_autofs_fd); return -errno; } log_debug("Autofs kernel version %i.%i", param.ver_major, param.ver_minor); return m->dev_autofs_fd; } static int open_ioctl_fd(int dev_autofs_fd, const char *where, dev_t devid) { struct autofs_dev_ioctl *param; size_t l; assert(dev_autofs_fd >= 0); assert(where); l = sizeof(struct autofs_dev_ioctl) + strlen(where) + 1; param = alloca(l); init_autofs_dev_ioctl(param); param->size = l; param->ioctlfd = -1; param->openmount.devid = devid; strcpy(param->path, where); if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_OPENMOUNT, param) < 0) return -errno; if (param->ioctlfd < 0) return -EIO; fd_cloexec(param->ioctlfd, true); return param->ioctlfd; } static int autofs_protocol(int dev_autofs_fd, int ioctl_fd) { uint32_t major, minor; struct autofs_dev_ioctl param; assert(dev_autofs_fd >= 0); assert(ioctl_fd >= 0); init_autofs_dev_ioctl(¶m); param.ioctlfd = ioctl_fd; if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOVER, ¶m) < 0) return -errno; major = param.protover.version; init_autofs_dev_ioctl(¶m); param.ioctlfd = ioctl_fd; if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOSUBVER, ¶m) < 0) return -errno; minor = param.protosubver.sub_version; log_debug("Autofs protocol version %i.%i", major, minor); return 0; } static int autofs_set_timeout(int dev_autofs_fd, int ioctl_fd, time_t sec) { struct autofs_dev_ioctl param; assert(dev_autofs_fd >= 0); assert(ioctl_fd >= 0); init_autofs_dev_ioctl(¶m); param.ioctlfd = ioctl_fd; param.timeout.timeout = sec; if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_TIMEOUT, ¶m) < 0) return -errno; return 0; } static int autofs_send_ready(int dev_autofs_fd, int ioctl_fd, uint32_t token, int status) { struct autofs_dev_ioctl param; assert(dev_autofs_fd >= 0); assert(ioctl_fd >= 0); init_autofs_dev_ioctl(¶m); param.ioctlfd = ioctl_fd; if (status) { param.fail.token = token; param.fail.status = status; } else param.ready.token = token; if (ioctl(dev_autofs_fd, status ? AUTOFS_DEV_IOCTL_FAIL : AUTOFS_DEV_IOCTL_READY, ¶m) < 0) return -errno; return 0; } int automount_send_ready(Automount *a, int status) { _cleanup_close_ int ioctl_fd = -1; unsigned token; int r; assert(a); assert(status <= 0); if (set_isempty(a->tokens)) return 0; ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id); if (ioctl_fd < 0) return ioctl_fd; if (status) log_debug_unit(UNIT(a)->id, "Sending failure: %s", strerror(-status)); else log_debug_unit(UNIT(a)->id, "Sending success."); r = 0; /* Autofs thankfully does not hand out 0 as a token */ while ((token = PTR_TO_UINT(set_steal_first(a->tokens)))) { int k; /* Autofs fun fact II: * * if you pass a positive status code here, the kernel will * freeze! Yay! */ k = autofs_send_ready(UNIT(a)->manager->dev_autofs_fd, ioctl_fd, token, status); if (k < 0) r = k; } return r; } static void automount_enter_waiting(Automount *a) { _cleanup_close_ int ioctl_fd = -1; int p[2] = { -1, -1 }; char name[32], options[128]; bool mounted = false; int r, dev_autofs_fd; struct stat st; assert(a); assert(a->pipe_fd < 0); assert(a->where); if (a->tokens) set_clear(a->tokens); dev_autofs_fd = open_dev_autofs(UNIT(a)->manager); if (dev_autofs_fd < 0) { r = dev_autofs_fd; goto fail; } /* We knowingly ignore the results of this call */ mkdir_p_label(a->where, 0555); warn_if_dir_nonempty(a->meta.id, a->where); if (pipe2(p, O_NONBLOCK|O_CLOEXEC) < 0) { r = -errno; goto fail; } snprintf(options, sizeof(options), "fd=%i,pgrp=%u,minproto=5,maxproto=5,direct", p[1], (unsigned) getpgrp()); char_array_0(options); snprintf(name, sizeof(name), "systemd-%u", (unsigned) getpid()); char_array_0(name); if (mount(name, a->where, "autofs", 0, options) < 0) { r = -errno; goto fail; } mounted = true; p[1] = safe_close(p[1]); if (stat(a->where, &st) < 0) { r = -errno; goto fail; } ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev); if (ioctl_fd < 0) { r = ioctl_fd; goto fail; } r = autofs_protocol(dev_autofs_fd, ioctl_fd); if (r < 0) goto fail; r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, 300); if (r < 0) goto fail; /* Autofs fun fact: * * Unless we close the ioctl fd here, for some weird reason * the direct mount will not receive events from the * kernel. */ r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, p[0], EPOLLIN, automount_dispatch_io, a); if (r < 0) goto fail; a->pipe_fd = p[0]; a->dev_id = st.st_dev; automount_set_state(a, AUTOMOUNT_WAITING); return; fail: safe_close_pair(p); if (mounted) repeat_unmount(a->where); log_error_unit(UNIT(a)->id, "Failed to initialize automounter: %s", strerror(-r)); automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES); } static void automount_enter_runnning(Automount *a) { _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL; struct stat st; int r; assert(a); /* We don't take mount requests anymore if we are supposed to * shut down anyway */ if (unit_stop_pending(UNIT(a))) { log_debug_unit(UNIT(a)->id, "Suppressing automount request on %s since unit stop is scheduled.", UNIT(a)->id); automount_send_ready(a, -EHOSTDOWN); return; } mkdir_p_label(a->where, a->directory_mode); /* Before we do anything, let's see if somebody is playing games with us? */ if (lstat(a->where, &st) < 0) { log_warning_unit(UNIT(a)->id, "%s failed to stat automount point: %m", UNIT(a)->id); goto fail; } if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id) log_info_unit(UNIT(a)->id, "%s's automount point already active?", UNIT(a)->id); else { r = manager_add_job(UNIT(a)->manager, JOB_START, UNIT_TRIGGER(UNIT(a)), JOB_REPLACE, true, &error, NULL); if (r < 0) { log_warning_unit(UNIT(a)->id, "%s failed to queue mount startup job: %s", UNIT(a)->id, bus_error_message(&error, r)); goto fail; } } automount_set_state(a, AUTOMOUNT_RUNNING); return; fail: automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES); } static int automount_start(Unit *u) { Automount *a = AUTOMOUNT(u); assert(a); assert(a->state == AUTOMOUNT_DEAD || a->state == AUTOMOUNT_FAILED); if (path_is_mount_point(a->where, false)) { log_error_unit(u->id, "Path %s is already a mount point, refusing start for %s", a->where, u->id); return -EEXIST; } if (UNIT_TRIGGER(u)->load_state != UNIT_LOADED) return -ENOENT; a->result = AUTOMOUNT_SUCCESS; automount_enter_waiting(a); return 0; } static int automount_stop(Unit *u) { Automount *a = AUTOMOUNT(u); assert(a); assert(a->state == AUTOMOUNT_WAITING || a->state == AUTOMOUNT_RUNNING); automount_enter_dead(a, AUTOMOUNT_SUCCESS); return 0; } static int automount_serialize(Unit *u, FILE *f, FDSet *fds) { Automount *a = AUTOMOUNT(u); void *p; Iterator i; assert(a); assert(f); assert(fds); unit_serialize_item(u, f, "state", automount_state_to_string(a->state)); unit_serialize_item(u, f, "result", automount_result_to_string(a->result)); unit_serialize_item_format(u, f, "dev-id", "%u", (unsigned) a->dev_id); SET_FOREACH(p, a->tokens, i) unit_serialize_item_format(u, f, "token", "%u", PTR_TO_UINT(p)); if (a->pipe_fd >= 0) { int copy; copy = fdset_put_dup(fds, a->pipe_fd); if (copy < 0) return copy; unit_serialize_item_format(u, f, "pipe-fd", "%i", copy); } return 0; } static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) { Automount *a = AUTOMOUNT(u); int r; assert(a); assert(fds); if (streq(key, "state")) { AutomountState state; state = automount_state_from_string(value); if (state < 0) log_debug_unit(u->id, "Failed to parse state value %s", value); else a->deserialized_state = state; } else if (streq(key, "result")) { AutomountResult f; f = automount_result_from_string(value); if (f < 0) log_debug_unit(u->id, "Failed to parse result value %s", value); else if (f != AUTOMOUNT_SUCCESS) a->result = f; } else if (streq(key, "dev-id")) { unsigned d; if (safe_atou(value, &d) < 0) log_debug_unit(u->id, "Failed to parse dev-id value %s", value); else a->dev_id = (unsigned) d; } else if (streq(key, "token")) { unsigned token; if (safe_atou(value, &token) < 0) log_debug_unit(u->id, "Failed to parse token value %s", value); else { if (!a->tokens) if (!(a->tokens = set_new(NULL))) return -ENOMEM; r = set_put(a->tokens, UINT_TO_PTR(token)); if (r < 0) return r; } } else if (streq(key, "pipe-fd")) { int fd; if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd)) log_debug_unit(u->id, "Failed to parse pipe-fd value %s", value); else { safe_close(a->pipe_fd); a->pipe_fd = fdset_remove(fds, fd); } } else log_debug_unit(u->id, "Unknown serialization key '%s'", key); return 0; } static UnitActiveState automount_active_state(Unit *u) { assert(u); return state_translation_table[AUTOMOUNT(u)->state]; } static const char *automount_sub_state_to_string(Unit *u) { assert(u); return automount_state_to_string(AUTOMOUNT(u)->state); } static bool automount_check_gc(Unit *u) { assert(u); if (!UNIT_TRIGGER(u)) return false; return UNIT_VTABLE(UNIT_TRIGGER(u))->check_gc(UNIT_TRIGGER(u)); } static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) { union autofs_v5_packet_union packet; Automount *a = AUTOMOUNT(userdata); ssize_t l; int r; assert(a); assert(fd == a->pipe_fd); if (events != EPOLLIN) { log_error_unit(UNIT(a)->id, "Got invalid poll event on pipe."); goto fail; } l = loop_read(a->pipe_fd, &packet, sizeof(packet), true); if (l != sizeof(packet)) { log_error_unit(UNIT(a)->id, "Invalid read from pipe: %s", l < 0 ? strerror(-l) : "short read"); goto fail; } switch (packet.hdr.type) { case autofs_ptype_missing_direct: if (packet.v5_packet.pid > 0) { _cleanup_free_ char *p = NULL; get_process_comm(packet.v5_packet.pid, &p); log_info_unit(UNIT(a)->id, "Got automount request for %s, triggered by "PID_FMT" (%s)", a->where, packet.v5_packet.pid, strna(p)); } else log_debug_unit(UNIT(a)->id, "Got direct mount request on %s", a->where); r = set_ensure_allocated(&a->tokens, NULL); if (r < 0) { log_error_unit(UNIT(a)->id, "Failed to allocate token set."); goto fail; } r = set_put(a->tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token)); if (r < 0) { log_error_unit(UNIT(a)->id, "Failed to remember token: %s", strerror(-r)); goto fail; } automount_enter_runnning(a); break; default: log_error_unit(UNIT(a)->id, "Received unknown automount request %i", packet.hdr.type); break; } return 0; fail: automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES); return 0; } static void automount_shutdown(Manager *m) { assert(m); m->dev_autofs_fd = safe_close(m->dev_autofs_fd); } static void automount_reset_failed(Unit *u) { Automount *a = AUTOMOUNT(u); assert(a); if (a->state == AUTOMOUNT_FAILED) automount_set_state(a, AUTOMOUNT_DEAD); a->result = AUTOMOUNT_SUCCESS; } static const char* const automount_state_table[_AUTOMOUNT_STATE_MAX] = { [AUTOMOUNT_DEAD] = "dead", [AUTOMOUNT_WAITING] = "waiting", [AUTOMOUNT_RUNNING] = "running", [AUTOMOUNT_FAILED] = "failed" }; DEFINE_STRING_TABLE_LOOKUP(automount_state, AutomountState); static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = { [AUTOMOUNT_SUCCESS] = "success", [AUTOMOUNT_FAILURE_RESOURCES] = "resources" }; DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult); const UnitVTable automount_vtable = { .object_size = sizeof(Automount), .sections = "Unit\0" "Automount\0" "Install\0", .no_alias = true, .no_instances = true, .init = automount_init, .load = automount_load, .done = automount_done, .coldplug = automount_coldplug, .dump = automount_dump, .start = automount_start, .stop = automount_stop, .serialize = automount_serialize, .deserialize_item = automount_deserialize_item, .active_state = automount_active_state, .sub_state_to_string = automount_sub_state_to_string, .check_gc = automount_check_gc, .reset_failed = automount_reset_failed, .bus_interface = "org.freedesktop.systemd1.Automount", .bus_vtable = bus_automount_vtable, .shutdown = automount_shutdown, .status_message_formats = { .finished_start_job = { [JOB_DONE] = "Set up automount %s.", [JOB_FAILED] = "Failed to set up automount %s.", [JOB_DEPENDENCY] = "Dependency failed for %s.", }, .finished_stop_job = { [JOB_DONE] = "Unset automount %s.", [JOB_FAILED] = "Failed to unset automount %s.", }, }, };