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authorLennart Poettering <lennart@poettering.net>2013-12-02 23:30:19 +0100
committerLennart Poettering <lennart@poettering.net>2013-12-02 23:32:34 +0100
commite821075a23fdfa3ca7738fc30bb2d4c430fe10c0 (patch)
tree37f970d8139c7796dda5ef0a295ee121ceabf349 /src/core/busname.c
parentf9638db8de2f915a5c5f6e4b7292494168eb4141 (diff)
bus: add .busname unit type to implement kdbus-style bus activation
Diffstat (limited to 'src/core/busname.c')
-rw-r--r--src/core/busname.c600
1 files changed, 600 insertions, 0 deletions
diff --git a/src/core/busname.c b/src/core/busname.c
new file mode 100644
index 0000000000..c45265658c
--- /dev/null
+++ b/src/core/busname.c
@@ -0,0 +1,600 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2013 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 "special.h"
+#include "bus-kernel.h"
+#include "bus-internal.h"
+#include "bus-util.h"
+#include "service.h"
+#include "dbus-busname.h"
+#include "busname.h"
+
+static const UnitActiveState state_translation_table[_BUSNAME_STATE_MAX] = {
+ [BUSNAME_DEAD] = UNIT_INACTIVE,
+ [BUSNAME_LISTENING] = UNIT_ACTIVE,
+ [BUSNAME_RUNNING] = UNIT_ACTIVE,
+ [BUSNAME_FAILED] = UNIT_FAILED
+};
+
+static int busname_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata);
+
+static void busname_init(Unit *u) {
+ BusName *n = BUSNAME(u);
+
+ assert(u);
+ assert(u->load_state == UNIT_STUB);
+
+ n->starter_fd = -1;
+}
+
+static void busname_done(Unit *u) {
+ BusName *n = BUSNAME(u);
+
+ assert(u);
+
+ free(n->name);
+ n->name = NULL;
+
+ unit_ref_unset(&n->service);
+
+ n->event_source = sd_event_source_unref(n->event_source);
+
+ if (n->starter_fd >= 0) {
+ close_nointr_nofail(n->starter_fd);
+ n->starter_fd = -1;
+ }
+}
+
+static int busname_add_default_default_dependencies(BusName *n) {
+ int r;
+
+ assert(n);
+
+ r = unit_add_dependency_by_name(UNIT(n), UNIT_BEFORE, SPECIAL_BUSNAMES_TARGET, NULL, true);
+ if (r < 0)
+ return r;
+
+ if (UNIT(n)->manager->running_as == SYSTEMD_SYSTEM) {
+ r = unit_add_two_dependencies_by_name(UNIT(n), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true);
+ if (r < 0)
+ return r;
+ }
+
+ return unit_add_two_dependencies_by_name(UNIT(n), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true);
+}
+
+static int busname_add_extras(BusName *n) {
+ Unit *u = UNIT(n);
+ int r;
+
+ assert(n);
+
+ if (!n->name) {
+ n->name = unit_name_to_prefix(u->id);
+ if (!n->name)
+ return -ENOMEM;
+ }
+
+ if (!u->description) {
+ r = unit_set_description(u, n->name);
+ if (r < 0)
+ return r;
+ }
+
+ if (!UNIT_DEREF(n->service)) {
+ Unit *x;
+
+ r = unit_load_related_unit(u, ".service", &x);
+ if (r < 0)
+ return r;
+
+ unit_ref_set(&n->service, x);
+ }
+
+ r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, UNIT_DEREF(n->service), true);
+ if (r < 0)
+ return r;
+
+ if (u->default_dependencies) {
+ r = busname_add_default_default_dependencies(n);
+ if (r < 0)
+ return r;
+ }
+
+ return 0;
+}
+
+
+
+static int busname_verify(BusName *n) {
+ char *e;
+
+ assert(n);
+
+ if (UNIT(n)->load_state != UNIT_LOADED)
+ return 0;
+
+ if (!service_name_is_valid(n->name)) {
+ log_error_unit(UNIT(n)->id, "%s's Name= setting is not a valid service name Refusing.", UNIT(n)->id);
+ return -EINVAL;
+ }
+
+ e = strappenda(n->name, ".busname");
+ if (!unit_has_name(UNIT(n), e)) {
+ log_error_unit(UNIT(n)->id, "%s's Name= setting doesn't match unit name. Refusing.", UNIT(n)->id);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int busname_load(Unit *u) {
+ BusName *n = BUSNAME(u);
+ int r;
+
+ assert(u);
+ assert(u->load_state == UNIT_STUB);
+
+ r = unit_load_fragment_and_dropin(u);
+ if (r < 0)
+ return r;
+
+ if (u->load_state == UNIT_LOADED) {
+ /* This is a new unit? Then let's add in some extras */
+ r = busname_add_extras(n);
+ if (r < 0)
+ return r;
+ }
+
+ return busname_verify(n);
+}
+
+static void busname_dump(Unit *u, FILE *f, const char *prefix) {
+ BusName *n = BUSNAME(u);
+
+ assert(n);
+ assert(f);
+
+ fprintf(f,
+ "%sBus Name State: %s\n"
+ "%sResult: %s\n"
+ "%sName: %s\n",
+ prefix, busname_state_to_string(n->state),
+ prefix, busname_result_to_string(n->result),
+ prefix, n->name);
+}
+
+static void busname_unwatch_fd(BusName *n) {
+ int r;
+
+ assert(n);
+
+ if (n->event_source) {
+ r = sd_event_source_set_enabled(n->event_source, SD_EVENT_OFF);
+ if (r < 0)
+ log_debug_unit(UNIT(n)->id, "Failed to disable event source.");
+ }
+}
+
+static void busname_close_fd(BusName *n) {
+ assert(n);
+
+ if (n->starter_fd <= 0)
+ return;
+
+ close_nointr_nofail(n->starter_fd);
+ n->starter_fd = -1;
+}
+
+static int busname_watch_fd(BusName *n) {
+ int r;
+
+ assert(n);
+
+ if (n->starter_fd < 0)
+ return 0;
+
+ if (n->event_source)
+ r = sd_event_source_set_enabled(n->event_source, SD_EVENT_ON);
+ else
+ r = sd_event_add_io(UNIT(n)->manager->event, n->starter_fd, EPOLLIN, busname_dispatch_io, n, &n->event_source);
+ if (r < 0) {
+ log_warning_unit(UNIT(n)->id, "Failed to watch starter fd: %s", strerror(-r));
+ busname_unwatch_fd(n);
+ return r;
+ }
+
+ return 0;
+}
+
+static int busname_open_fd(BusName *n) {
+ assert(n);
+
+ if (n->starter_fd >= 0)
+ return 0;
+
+ n->starter_fd = bus_kernel_create_starter(UNIT(n)->manager->running_as == SYSTEMD_SYSTEM ? "system" : "user", n->name);
+ if (n->starter_fd < 0) {
+ log_warning_unit(UNIT(n)->id, "Failed to create starter fd: %s", strerror(-n->starter_fd));
+ return n->starter_fd;
+ }
+
+ return 0;
+}
+
+static void busname_set_state(BusName *n, BusNameState state) {
+ BusNameState old_state;
+ assert(n);
+
+ old_state = n->state;
+ n->state = state;
+
+ if (state != BUSNAME_LISTENING)
+ busname_unwatch_fd(n);
+
+ if (!IN_SET(state, BUSNAME_LISTENING, BUSNAME_RUNNING))
+ busname_close_fd(n);
+
+ if (state != old_state)
+ log_debug_unit(UNIT(n)->id, "%s changed %s -> %s",
+ UNIT(n)->id, busname_state_to_string(old_state), busname_state_to_string(state));
+
+ unit_notify(UNIT(n), state_translation_table[old_state], state_translation_table[state], true);
+}
+
+static int busname_coldplug(Unit *u) {
+ BusName *n = BUSNAME(u);
+ int r;
+
+ assert(n);
+ assert(n->state == BUSNAME_DEAD);
+
+ if (n->deserialized_state == n->state)
+ return 0;
+
+ if (IN_SET(n->deserialized_state, BUSNAME_LISTENING, BUSNAME_RUNNING)) {
+ r = busname_open_fd(n);
+ if (r < 0)
+ return r;
+ }
+
+ if (n->deserialized_state == BUSNAME_LISTENING) {
+ r = busname_watch_fd(n);
+ if (r < 0)
+ return r;
+ }
+
+ busname_set_state(n, n->deserialized_state);
+ return 0;
+}
+
+static void busname_enter_dead(BusName *n, BusNameResult f) {
+ assert(n);
+
+ if (f != BUSNAME_SUCCESS)
+ n->result = f;
+
+ busname_set_state(n, n->result != BUSNAME_SUCCESS ? BUSNAME_FAILED : BUSNAME_DEAD);
+}
+
+static void busname_enter_listening(BusName *n) {
+ int r;
+
+ assert(n);
+
+ r = busname_open_fd(n);
+ if (r < 0) {
+ log_warning_unit(UNIT(n)->id, "%s failed to listen on bus names: %s", UNIT(n)->id, strerror(-r));
+ goto fail;
+ }
+
+ r = busname_watch_fd(n);
+ if (r < 0) {
+ log_warning_unit(UNIT(n)->id, "%s failed to watch names: %s", UNIT(n)->id, strerror(-r));
+ goto fail;
+ }
+
+ busname_set_state(n, BUSNAME_LISTENING);
+ return;
+
+fail:
+ busname_enter_dead(n, BUSNAME_FAILURE_RESOURCES);
+}
+
+static void busname_enter_running(BusName *n) {
+ _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+ bool pending = false;
+ Unit *other;
+ Iterator i;
+ int r;
+
+ assert(n);
+
+ /* We don't take conenctions anymore if we are supposed to
+ * shut down anyway */
+
+ if (unit_stop_pending(UNIT(n))) {
+ log_debug_unit(UNIT(n)->id, "Suppressing activation request on %s since unit stop is scheduled.", UNIT(n)->id);
+ return;
+ }
+
+ /* If there's already a start pending don't bother to do
+ * anything */
+ SET_FOREACH(other, UNIT(n)->dependencies[UNIT_TRIGGERS], i)
+ if (unit_active_or_pending(other)) {
+ pending = true;
+ break;
+ }
+
+ if (!pending) {
+ r = manager_add_job(UNIT(n)->manager, JOB_START, UNIT_DEREF(n->service), JOB_REPLACE, true, &error, NULL);
+ if (r < 0)
+ goto fail;
+ }
+
+ busname_set_state(n, BUSNAME_RUNNING);
+ return;
+
+fail:
+ log_warning_unit(UNIT(n)->id, "%s failed to queue service startup job: %s", UNIT(n)->id, bus_error_message(&error, r));
+ busname_enter_dead(n, BUSNAME_FAILURE_RESOURCES);
+}
+
+static int busname_start(Unit *u) {
+ BusName *n = BUSNAME(u);
+
+ assert(n);
+
+ if (UNIT_ISSET(n->service)) {
+ Service *service;
+
+ service = SERVICE(UNIT_DEREF(n->service));
+
+ if (UNIT(service)->load_state != UNIT_LOADED) {
+ log_error_unit(u->id, "Bus service %s not loaded, refusing.", UNIT(service)->id);
+ return -ENOENT;
+ }
+ }
+
+ assert(IN_SET(n->state, BUSNAME_DEAD, BUSNAME_FAILED));
+
+ n->result = BUSNAME_SUCCESS;
+ busname_enter_listening(n);
+
+ return 0;
+}
+
+static int busname_stop(Unit *u) {
+ BusName *n = BUSNAME(u);
+
+ assert(n);
+ assert(n->state == BUSNAME_LISTENING || n->state == BUSNAME_RUNNING);
+
+ busname_enter_dead(n, BUSNAME_SUCCESS);
+ return 0;
+}
+
+static int busname_serialize(Unit *u, FILE *f, FDSet *fds) {
+ BusName *n = BUSNAME(u);
+
+ assert(n);
+ assert(f);
+ assert(fds);
+
+ unit_serialize_item(u, f, "state", busname_state_to_string(n->state));
+ unit_serialize_item(u, f, "result", busname_result_to_string(n->result));
+
+ if (n->starter_fd >= 0) {
+ int copy;
+
+ copy = fdset_put_dup(fds, n->starter_fd);
+ if (copy < 0)
+ return copy;
+
+ unit_serialize_item_format(u, f, "starter-fd", "%i", copy);
+ }
+
+ return 0;
+}
+
+static int busname_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
+ BusName *n = BUSNAME(u);
+
+ assert(n);
+ assert(key);
+ assert(value);
+
+ if (streq(key, "state")) {
+ BusNameState state;
+
+ state = busname_state_from_string(value);
+ if (state < 0)
+ log_debug_unit(u->id, "Failed to parse state value %s", value);
+ else
+ n->deserialized_state = state;
+
+ } else if (streq(key, "result")) {
+ BusNameResult f;
+
+ f = busname_result_from_string(value);
+ if (f < 0)
+ log_debug_unit(u->id, "Failed to parse result value %s", value);
+ else if (f != BUSNAME_SUCCESS)
+ n->result = f;
+
+ } else if (streq(key, "starter-fd")) {
+ int fd;
+
+ if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))
+ log_debug_unit(u->id, "Failed to parse starter fd value %s", value);
+ else {
+ if (n->starter_fd >= 0)
+ close_nointr_nofail(n->starter_fd);
+ n->starter_fd = fdset_remove(fds, fd);
+ }
+ } else
+ log_debug_unit(u->id, "Unknown serialization key '%s'", key);
+
+ return 0;
+}
+
+_pure_ static UnitActiveState busname_active_state(Unit *u) {
+ assert(u);
+
+ return state_translation_table[BUSNAME(u)->state];
+}
+
+_pure_ static const char *busname_sub_state_to_string(Unit *u) {
+ assert(u);
+
+ return busname_state_to_string(BUSNAME(u)->state);
+}
+
+static int busname_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
+ BusName *n = userdata;
+
+ assert(n);
+ assert(fd >= 0);
+
+ if (n->state != BUSNAME_LISTENING)
+ return 0;
+
+ log_debug_unit(UNIT(n)->id, "Activation request on %s", UNIT(n)->id);
+
+ if (revents != EPOLLIN) {
+ log_error_unit(UNIT(n)->id, "%s: Got unexpected poll event (0x%x) on starter fd.",
+ UNIT(n)->id, revents);
+ goto fail;
+ }
+
+ busname_enter_running(n);
+ return 0;
+fail:
+
+ busname_enter_dead(n, BUSNAME_FAILURE_RESOURCES);
+ return 0;
+}
+
+static void busname_reset_failed(Unit *u) {
+ BusName *n = BUSNAME(u);
+
+ assert(n);
+
+ if (n->state == BUSNAME_FAILED)
+ busname_set_state(n, BUSNAME_DEAD);
+
+ n->result = BUSNAME_SUCCESS;
+}
+
+static void busname_trigger_notify(Unit *u, Unit *other) {
+ BusName *n = BUSNAME(u);
+ Service *s;
+
+ assert(n);
+ assert(other);
+
+ if (!IN_SET(n->state, BUSNAME_RUNNING, BUSNAME_LISTENING))
+ return;
+
+ if (other->load_state != UNIT_LOADED || other->type != UNIT_SERVICE)
+ return;
+
+ s = SERVICE(other);
+
+ if (s->state == SERVICE_FAILED) {
+ if (s->result == SERVICE_FAILURE_START_LIMIT)
+ busname_enter_dead(n, BUSNAME_FAILURE_SERVICE_FAILED_PERMANENT);
+ else
+ busname_enter_listening(n);
+ }
+
+ if (IN_SET(n->state,
+ SERVICE_DEAD,
+ SERVICE_STOP, SERVICE_STOP_SIGTERM, SERVICE_STOP_SIGKILL,
+ SERVICE_STOP_POST, SERVICE_FINAL_SIGTERM, SERVICE_FINAL_SIGKILL,
+ SERVICE_AUTO_RESTART))
+ busname_enter_listening(n);
+}
+
+static const char* const busname_state_table[_BUSNAME_STATE_MAX] = {
+ [BUSNAME_DEAD] = "dead",
+ [BUSNAME_LISTENING] = "listening",
+ [BUSNAME_RUNNING] = "running",
+ [BUSNAME_FAILED] = "failed"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(busname_state, BusNameState);
+
+static const char* const busname_result_table[_BUSNAME_RESULT_MAX] = {
+ [BUSNAME_SUCCESS] = "success",
+ [BUSNAME_FAILURE_RESOURCES] = "resources",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(busname_result, BusNameResult);
+
+const UnitVTable busname_vtable = {
+ .object_size = sizeof(BusName),
+
+ .sections =
+ "Unit\0"
+ "BusName\0"
+ "Install\0",
+ .private_section = "BusName",
+
+ .init = busname_init,
+ .done = busname_done,
+ .load = busname_load,
+
+ .coldplug = busname_coldplug,
+
+ .dump = busname_dump,
+
+ .start = busname_start,
+ .stop = busname_stop,
+
+ .serialize = busname_serialize,
+ .deserialize_item = busname_deserialize_item,
+
+ .active_state = busname_active_state,
+ .sub_state_to_string = busname_sub_state_to_string,
+
+ .trigger_notify = busname_trigger_notify,
+
+ .reset_failed = busname_reset_failed,
+
+ .bus_interface = "org.freedesktop.systemd1.BusName",
+ .bus_vtable = bus_busname_vtable,
+ .bus_changing_properties = bus_busname_changing_properties,
+
+ .status_message_formats = {
+ .finished_start_job = {
+ [JOB_DONE] = "Listening on %s.",
+ [JOB_FAILED] = "Failed to listen on %s.",
+ [JOB_DEPENDENCY] = "Dependency failed for %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.",
+ },
+ },
+};