diff options
Diffstat (limited to 'src/libcore/dbus.c')
| -rw-r--r-- | src/libcore/dbus.c | 1258 |
1 files changed, 1258 insertions, 0 deletions
diff --git a/src/libcore/dbus.c b/src/libcore/dbus.c new file mode 100644 index 0000000000..413489373f --- /dev/null +++ b/src/libcore/dbus.c @@ -0,0 +1,1258 @@ +/*** + 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 <sys/epoll.h> +#include <unistd.h> + +#include "sd-bus.h" + +#include "alloc-util.h" +#include "bus-common-errors.h" +#include "bus-error.h" +#include "bus-internal.h" +#include "bus-util.h" +#include "dbus-cgroup.h" +#include "dbus-execute.h" +#include "dbus-job.h" +#include "dbus-kill.h" +#include "dbus-manager.h" +#include "dbus-unit.h" +#include "dbus.h" +#include "fd-util.h" +#include "log.h" +#include "missing.h" +#include "mkdir.h" +#include "selinux-access.h" +#include "special.h" +#include "string-util.h" +#include "strv.h" +#include "strxcpyx.h" +#include "user-util.h" + +#define CONNECTIONS_MAX 4096 + +static void destroy_bus(Manager *m, sd_bus **bus); + +int bus_send_queued_message(Manager *m) { + int r; + + assert(m); + + if (!m->queued_message) + return 0; + + /* If we cannot get rid of this message we won't dispatch any + * D-Bus messages, so that we won't end up wanting to queue + * another message. */ + + r = sd_bus_send(NULL, m->queued_message, NULL); + if (r < 0) + log_warning_errno(r, "Failed to send queued message: %m"); + + m->queued_message = sd_bus_message_unref(m->queued_message); + + return 0; +} + +static int signal_agent_released(sd_bus_message *message, void *userdata, sd_bus_error *error) { + _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL; + const char *cgroup, *me; + Manager *m = userdata; + uid_t sender_uid; + sd_bus *bus; + int r; + + assert(message); + assert(m); + + /* ignore recursive events sent by us on the system/user bus */ + bus = sd_bus_message_get_bus(message); + if (!sd_bus_is_server(bus)) { + r = sd_bus_get_unique_name(bus, &me); + if (r < 0) + return r; + + if (streq_ptr(sd_bus_message_get_sender(message), me)) + return 0; + } + + /* only accept org.freedesktop.systemd1.Agent from UID=0 */ + r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_EUID, &creds); + if (r < 0) + return r; + + r = sd_bus_creds_get_euid(creds, &sender_uid); + if (r < 0 || sender_uid != 0) + return 0; + + /* parse 'cgroup-empty' notification */ + r = sd_bus_message_read(message, "s", &cgroup); + if (r < 0) { + bus_log_parse_error(r); + return 0; + } + + manager_notify_cgroup_empty(m, cgroup); + + /* if running as system-instance, forward under our name */ + if (m->running_as == MANAGER_SYSTEM && m->system_bus) { + r = sd_bus_message_rewind(message, 1); + if (r >= 0) + r = sd_bus_send(m->system_bus, message, NULL); + if (r < 0) + log_warning_errno(r, "Failed to forward Released message: %m"); + } + + return 0; +} + +static int signal_disconnected(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Manager *m = userdata; + sd_bus *bus; + + assert(message); + assert(m); + assert_se(bus = sd_bus_message_get_bus(message)); + + if (bus == m->api_bus) + destroy_bus(m, &m->api_bus); + if (bus == m->system_bus) + destroy_bus(m, &m->system_bus); + if (set_remove(m->private_buses, bus)) { + log_debug("Got disconnect on private connection."); + destroy_bus(m, &bus); + } + + return 0; +} + +static int signal_activation_request(sd_bus_message *message, void *userdata, sd_bus_error *ret_error) { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; + Manager *m = userdata; + const char *name; + Unit *u; + int r; + + assert(message); + assert(m); + + r = sd_bus_message_read(message, "s", &name); + if (r < 0) { + bus_log_parse_error(r); + return 0; + } + + if (manager_unit_inactive_or_pending(m, SPECIAL_DBUS_SERVICE) || + manager_unit_inactive_or_pending(m, SPECIAL_DBUS_SOCKET)) { + r = sd_bus_error_setf(&error, BUS_ERROR_SHUTTING_DOWN, "Refusing activation, D-Bus is shutting down."); + goto failed; + } + + r = manager_load_unit(m, name, NULL, &error, &u); + if (r < 0) + goto failed; + + if (u->refuse_manual_start) { + r = sd_bus_error_setf(&error, BUS_ERROR_ONLY_BY_DEPENDENCY, "Operation refused, %s may be requested by dependency only.", u->id); + goto failed; + } + + r = manager_add_job(m, JOB_START, u, JOB_REPLACE, &error, NULL); + if (r < 0) + goto failed; + + /* Successfully queued, that's it for us */ + return 0; + +failed: + if (!sd_bus_error_is_set(&error)) + sd_bus_error_set_errno(&error, r); + + log_debug("D-Bus activation failed for %s: %s", name, bus_error_message(&error, r)); + + r = sd_bus_message_new_signal(sd_bus_message_get_bus(message), &reply, "/org/freedesktop/systemd1", "org.freedesktop.systemd1.Activator", "ActivationFailure"); + if (r < 0) { + bus_log_create_error(r); + return 0; + } + + r = sd_bus_message_append(reply, "sss", name, error.name, error.message); + if (r < 0) { + bus_log_create_error(r); + return 0; + } + + r = sd_bus_send_to(NULL, reply, "org.freedesktop.DBus", NULL); + if (r < 0) + return log_error_errno(r, "Failed to respond with to bus activation request: %m"); + + return 0; +} + +#ifdef HAVE_SELINUX +static int mac_selinux_filter(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Manager *m = userdata; + const char *verb, *path; + Unit *u = NULL; + Job *j; + int r; + + assert(message); + + /* Our own method calls are all protected individually with + * selinux checks, but the built-in interfaces need to be + * protected too. */ + + if (sd_bus_message_is_method_call(message, "org.freedesktop.DBus.Properties", "Set")) + verb = "reload"; + else if (sd_bus_message_is_method_call(message, "org.freedesktop.DBus.Introspectable", NULL) || + sd_bus_message_is_method_call(message, "org.freedesktop.DBus.Properties", NULL) || + sd_bus_message_is_method_call(message, "org.freedesktop.DBus.ObjectManager", NULL) || + sd_bus_message_is_method_call(message, "org.freedesktop.DBus.Peer", NULL)) + verb = "status"; + else + return 0; + + path = sd_bus_message_get_path(message); + + if (object_path_startswith("/org/freedesktop/systemd1", path)) { + + r = mac_selinux_access_check(message, verb, error); + if (r < 0) + return r; + + return 0; + } + + if (streq_ptr(path, "/org/freedesktop/systemd1/unit/self")) { + _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL; + pid_t pid; + + r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_PID, &creds); + if (r < 0) + return 0; + + r = sd_bus_creds_get_pid(creds, &pid); + if (r < 0) + return 0; + + u = manager_get_unit_by_pid(m, pid); + } else { + r = manager_get_job_from_dbus_path(m, path, &j); + if (r >= 0) + u = j->unit; + else + manager_load_unit_from_dbus_path(m, path, NULL, &u); + } + + if (!u) + return 0; + + r = mac_selinux_unit_access_check(u, message, verb, error); + if (r < 0) + return r; + + return 0; +} +#endif + +static int bus_job_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) { + Manager *m = userdata; + Job *j; + int r; + + assert(bus); + assert(path); + assert(interface); + assert(found); + assert(m); + + r = manager_get_job_from_dbus_path(m, path, &j); + if (r < 0) + return 0; + + *found = j; + return 1; +} + +static int find_unit(Manager *m, sd_bus *bus, const char *path, Unit **unit, sd_bus_error *error) { + Unit *u; + int r; + + assert(m); + assert(bus); + assert(path); + + if (streq_ptr(path, "/org/freedesktop/systemd1/unit/self")) { + _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL; + sd_bus_message *message; + pid_t pid; + + message = sd_bus_get_current_message(bus); + if (!message) + return 0; + + r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_PID, &creds); + if (r < 0) + return r; + + r = sd_bus_creds_get_pid(creds, &pid); + if (r < 0) + return r; + + u = manager_get_unit_by_pid(m, pid); + } else { + r = manager_load_unit_from_dbus_path(m, path, error, &u); + if (r < 0) + return 0; + } + + if (!u) + return 0; + + *unit = u; + return 1; +} + +static int bus_unit_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) { + Manager *m = userdata; + + assert(bus); + assert(path); + assert(interface); + assert(found); + assert(m); + + return find_unit(m, bus, path, (Unit**) found, error); +} + +static int bus_unit_interface_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) { + Manager *m = userdata; + Unit *u; + int r; + + assert(bus); + assert(path); + assert(interface); + assert(found); + assert(m); + + r = find_unit(m, bus, path, &u, error); + if (r <= 0) + return r; + + if (!streq_ptr(interface, unit_dbus_interface_from_type(u->type))) + return 0; + + *found = u; + return 1; +} + +static int bus_unit_cgroup_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) { + Manager *m = userdata; + Unit *u; + int r; + + assert(bus); + assert(path); + assert(interface); + assert(found); + assert(m); + + r = find_unit(m, bus, path, &u, error); + if (r <= 0) + return r; + + if (!streq_ptr(interface, unit_dbus_interface_from_type(u->type))) + return 0; + + if (!UNIT_HAS_CGROUP_CONTEXT(u)) + return 0; + + *found = u; + return 1; +} + +static int bus_cgroup_context_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) { + Manager *m = userdata; + CGroupContext *c; + Unit *u; + int r; + + assert(bus); + assert(path); + assert(interface); + assert(found); + assert(m); + + r = find_unit(m, bus, path, &u, error); + if (r <= 0) + return r; + + if (!streq_ptr(interface, unit_dbus_interface_from_type(u->type))) + return 0; + + c = unit_get_cgroup_context(u); + if (!c) + return 0; + + *found = c; + return 1; +} + +static int bus_exec_context_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) { + Manager *m = userdata; + ExecContext *c; + Unit *u; + int r; + + assert(bus); + assert(path); + assert(interface); + assert(found); + assert(m); + + r = find_unit(m, bus, path, &u, error); + if (r <= 0) + return r; + + if (!streq_ptr(interface, unit_dbus_interface_from_type(u->type))) + return 0; + + c = unit_get_exec_context(u); + if (!c) + return 0; + + *found = c; + return 1; +} + +static int bus_kill_context_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) { + Manager *m = userdata; + KillContext *c; + Unit *u; + int r; + + assert(bus); + assert(path); + assert(interface); + assert(found); + assert(m); + + r = find_unit(m, bus, path, &u, error); + if (r <= 0) + return r; + + if (!streq_ptr(interface, unit_dbus_interface_from_type(u->type))) + return 0; + + c = unit_get_kill_context(u); + if (!c) + return 0; + + *found = c; + return 1; +} + +static int bus_job_enumerate(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) { + _cleanup_free_ char **l = NULL; + Manager *m = userdata; + unsigned k = 0; + Iterator i; + Job *j; + + l = new0(char*, hashmap_size(m->jobs)+1); + if (!l) + return -ENOMEM; + + HASHMAP_FOREACH(j, m->jobs, i) { + l[k] = job_dbus_path(j); + if (!l[k]) + return -ENOMEM; + + k++; + } + + assert(hashmap_size(m->jobs) == k); + + *nodes = l; + l = NULL; + + return k; +} + +static int bus_unit_enumerate(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) { + _cleanup_free_ char **l = NULL; + Manager *m = userdata; + unsigned k = 0; + Iterator i; + Unit *u; + + l = new0(char*, hashmap_size(m->units)+1); + if (!l) + return -ENOMEM; + + HASHMAP_FOREACH(u, m->units, i) { + l[k] = unit_dbus_path(u); + if (!l[k]) + return -ENOMEM; + + k++; + } + + *nodes = l; + l = NULL; + + return k; +} + +static int bus_setup_api_vtables(Manager *m, sd_bus *bus) { + UnitType t; + int r; + + assert(m); + assert(bus); + +#ifdef HAVE_SELINUX + r = sd_bus_add_filter(bus, NULL, mac_selinux_filter, m); + if (r < 0) + return log_error_errno(r, "Failed to add SELinux access filter: %m"); +#endif + + r = sd_bus_add_object_vtable(bus, NULL, "/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", bus_manager_vtable, m); + if (r < 0) + return log_error_errno(r, "Failed to register Manager vtable: %m"); + + r = sd_bus_add_fallback_vtable(bus, NULL, "/org/freedesktop/systemd1/job", "org.freedesktop.systemd1.Job", bus_job_vtable, bus_job_find, m); + if (r < 0) + return log_error_errno(r, "Failed to register Job vtable: %m"); + + r = sd_bus_add_node_enumerator(bus, NULL, "/org/freedesktop/systemd1/job", bus_job_enumerate, m); + if (r < 0) + return log_error_errno(r, "Failed to add job enumerator: %m"); + + r = sd_bus_add_fallback_vtable(bus, NULL, "/org/freedesktop/systemd1/unit", "org.freedesktop.systemd1.Unit", bus_unit_vtable, bus_unit_find, m); + if (r < 0) + return log_error_errno(r, "Failed to register Unit vtable: %m"); + + r = sd_bus_add_node_enumerator(bus, NULL, "/org/freedesktop/systemd1/unit", bus_unit_enumerate, m); + if (r < 0) + return log_error_errno(r, "Failed to add job enumerator: %m"); + + for (t = 0; t < _UNIT_TYPE_MAX; t++) { + const char *interface; + + assert_se(interface = unit_dbus_interface_from_type(t)); + + r = sd_bus_add_fallback_vtable(bus, NULL, "/org/freedesktop/systemd1/unit", interface, unit_vtable[t]->bus_vtable, bus_unit_interface_find, m); + if (r < 0) + return log_error_errno(r, "Failed to register type specific vtable for %s: %m", interface); + + if (unit_vtable[t]->cgroup_context_offset > 0) { + r = sd_bus_add_fallback_vtable(bus, NULL, "/org/freedesktop/systemd1/unit", interface, bus_unit_cgroup_vtable, bus_unit_cgroup_find, m); + if (r < 0) + return log_error_errno(r, "Failed to register control group unit vtable for %s: %m", interface); + + r = sd_bus_add_fallback_vtable(bus, NULL, "/org/freedesktop/systemd1/unit", interface, bus_cgroup_vtable, bus_cgroup_context_find, m); + if (r < 0) + return log_error_errno(r, "Failed to register control group vtable for %s: %m", interface); + } + + if (unit_vtable[t]->exec_context_offset > 0) { + r = sd_bus_add_fallback_vtable(bus, NULL, "/org/freedesktop/systemd1/unit", interface, bus_exec_vtable, bus_exec_context_find, m); + if (r < 0) + return log_error_errno(r, "Failed to register execute vtable for %s: %m", interface); + } + + if (unit_vtable[t]->kill_context_offset > 0) { + r = sd_bus_add_fallback_vtable(bus, NULL, "/org/freedesktop/systemd1/unit", interface, bus_kill_vtable, bus_kill_context_find, m); + if (r < 0) + return log_error_errno(r, "Failed to register kill vtable for %s: %m", interface); + } + } + + return 0; +} + +static int bus_setup_disconnected_match(Manager *m, sd_bus *bus) { + int r; + + assert(m); + assert(bus); + + r = sd_bus_add_match( + bus, + NULL, + "sender='org.freedesktop.DBus.Local'," + "type='signal'," + "path='/org/freedesktop/DBus/Local'," + "interface='org.freedesktop.DBus.Local'," + "member='Disconnected'", + signal_disconnected, m); + + if (r < 0) + return log_error_errno(r, "Failed to register match for Disconnected message: %m"); + + return 0; +} + +static int bus_on_connection(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; + _cleanup_close_ int nfd = -1; + Manager *m = userdata; + sd_id128_t id; + int r; + + assert(s); + assert(m); + + nfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC); + if (nfd < 0) { + log_warning_errno(errno, "Failed to accept private connection, ignoring: %m"); + return 0; + } + + if (set_size(m->private_buses) >= CONNECTIONS_MAX) { + log_warning("Too many concurrent connections, refusing"); + return 0; + } + + r = set_ensure_allocated(&m->private_buses, NULL); + if (r < 0) { + log_oom(); + return 0; + } + + r = sd_bus_new(&bus); + if (r < 0) { + log_warning_errno(r, "Failed to allocate new private connection bus: %m"); + return 0; + } + + r = sd_bus_set_fd(bus, nfd, nfd); + if (r < 0) { + log_warning_errno(r, "Failed to set fd on new connection bus: %m"); + return 0; + } + + nfd = -1; + + r = bus_check_peercred(bus); + if (r < 0) { + log_warning_errno(r, "Incoming private connection from unprivileged client, refusing: %m"); + return 0; + } + + assert_se(sd_id128_randomize(&id) >= 0); + + r = sd_bus_set_server(bus, 1, id); + if (r < 0) { + log_warning_errno(r, "Failed to enable server support for new connection bus: %m"); + return 0; + } + + r = sd_bus_negotiate_creds(bus, 1, + SD_BUS_CREDS_PID|SD_BUS_CREDS_UID| + SD_BUS_CREDS_EUID|SD_BUS_CREDS_EFFECTIVE_CAPS| + SD_BUS_CREDS_SELINUX_CONTEXT); + if (r < 0) { + log_warning_errno(r, "Failed to enable credentials for new connection: %m"); + return 0; + } + + r = sd_bus_start(bus); + if (r < 0) { + log_warning_errno(r, "Failed to start new connection bus: %m"); + return 0; + } + + r = sd_bus_attach_event(bus, m->event, SD_EVENT_PRIORITY_NORMAL); + if (r < 0) { + log_warning_errno(r, "Failed to attach new connection bus to event loop: %m"); + return 0; + } + + if (m->running_as == MANAGER_SYSTEM) { + /* When we run as system instance we get the Released + * signal via a direct connection */ + + r = sd_bus_add_match( + bus, + NULL, + "type='signal'," + "interface='org.freedesktop.systemd1.Agent'," + "member='Released'," + "path='/org/freedesktop/systemd1/agent'", + signal_agent_released, m); + + if (r < 0) { + log_warning_errno(r, "Failed to register Released match on new connection bus: %m"); + return 0; + } + } + + r = bus_setup_disconnected_match(m, bus); + if (r < 0) + return 0; + + r = bus_setup_api_vtables(m, bus); + if (r < 0) { + log_warning_errno(r, "Failed to set up API vtables on new connection bus: %m"); + return 0; + } + + r = set_put(m->private_buses, bus); + if (r < 0) { + log_warning_errno(r, "Failed to add new connection bus to set: %m"); + return 0; + } + + bus = NULL; + + log_debug("Accepted new private connection."); + + return 0; +} + +int manager_sync_bus_names(Manager *m, sd_bus *bus) { + _cleanup_strv_free_ char **names = NULL; + const char *name; + Iterator i; + Unit *u; + int r; + + assert(m); + assert(bus); + + r = sd_bus_list_names(bus, &names, NULL); + if (r < 0) + return log_error_errno(r, "Failed to get initial list of names: %m"); + + /* We have to synchronize the current bus names with the + * list of active services. To do this, walk the list of + * all units with bus names. */ + HASHMAP_FOREACH_KEY(u, name, m->watch_bus, i) { + Service *s = SERVICE(u); + + assert(s); + + if (!streq_ptr(s->bus_name, name)) { + log_unit_warning(u, "Bus name has changed from %s → %s, ignoring.", s->bus_name, name); + continue; + } + + /* Check if a service's bus name is in the list of currently + * active names */ + if (strv_contains(names, name)) { + _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL; + const char *unique; + + /* If it is, determine its current owner */ + r = sd_bus_get_name_creds(bus, name, SD_BUS_CREDS_UNIQUE_NAME, &creds); + if (r < 0) { + log_error_errno(r, "Failed to get bus name owner %s: %m", name); + continue; + } + + r = sd_bus_creds_get_unique_name(creds, &unique); + if (r < 0) { + log_error_errno(r, "Failed to get unique name for %s: %m", name); + continue; + } + + /* Now, let's compare that to the previous bus owner, and + * if it's still the same, all is fine, so just don't + * bother the service. Otherwise, the name has apparently + * changed, so synthesize a name owner changed signal. */ + + if (!streq_ptr(unique, s->bus_name_owner)) + UNIT_VTABLE(u)->bus_name_owner_change(u, name, s->bus_name_owner, unique); + } else { + /* So, the name we're watching is not on the bus. + * This either means it simply hasn't appeared yet, + * or it was lost during the daemon reload. + * Check if the service has a stored name owner, + * and synthesize a name loss signal in this case. */ + + if (s->bus_name_owner) + UNIT_VTABLE(u)->bus_name_owner_change(u, name, s->bus_name_owner, NULL); + } + } + + return 0; +} + +static int bus_setup_api(Manager *m, sd_bus *bus) { + Iterator i; + char *name; + Unit *u; + int r; + + assert(m); + assert(bus); + + /* Let's make sure we have enough credential bits so that we can make security and selinux decisions */ + r = sd_bus_negotiate_creds(bus, 1, + SD_BUS_CREDS_PID|SD_BUS_CREDS_UID| + SD_BUS_CREDS_EUID|SD_BUS_CREDS_EFFECTIVE_CAPS| + SD_BUS_CREDS_SELINUX_CONTEXT); + if (r < 0) + log_warning_errno(r, "Failed to enable credential passing, ignoring: %m"); + + r = bus_setup_api_vtables(m, bus); + if (r < 0) + return r; + + HASHMAP_FOREACH_KEY(u, name, m->watch_bus, i) { + r = unit_install_bus_match(u, bus, name); + if (r < 0) + log_error_errno(r, "Failed to subscribe to NameOwnerChanged signal for '%s': %m", name); + } + + r = sd_bus_add_match( + bus, + NULL, + "type='signal'," + "sender='org.freedesktop.DBus'," + "path='/org/freedesktop/DBus'," + "interface='org.freedesktop.systemd1.Activator'," + "member='ActivationRequest'", + signal_activation_request, m); + if (r < 0) + log_warning_errno(r, "Failed to subscribe to activation signal: %m"); + + /* Allow replacing of our name, to ease implementation of + * reexecution, where we keep the old connection open until + * after the new connection is set up and the name installed + * to allow clients to synchronously wait for reexecution to + * finish */ + r = sd_bus_request_name(bus,"org.freedesktop.systemd1", SD_BUS_NAME_REPLACE_EXISTING|SD_BUS_NAME_ALLOW_REPLACEMENT); + if (r < 0) + return log_error_errno(r, "Failed to register name: %m"); + + r = manager_sync_bus_names(m, bus); + if (r < 0) + return r; + + log_debug("Successfully connected to API bus."); + return 0; +} + +static int bus_init_api(Manager *m) { + _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; + int r; + + if (m->api_bus) + return 0; + + /* The API and system bus is the same if we are running in system mode */ + if (m->running_as == MANAGER_SYSTEM && m->system_bus) + bus = sd_bus_ref(m->system_bus); + else { + if (m->running_as == MANAGER_SYSTEM) + r = sd_bus_open_system(&bus); + else + r = sd_bus_open_user(&bus); + + if (r < 0) { + log_debug("Failed to connect to API bus, retrying later..."); + return 0; + } + + r = sd_bus_attach_event(bus, m->event, SD_EVENT_PRIORITY_NORMAL); + if (r < 0) { + log_error_errno(r, "Failed to attach API bus to event loop: %m"); + return 0; + } + + r = bus_setup_disconnected_match(m, bus); + if (r < 0) + return 0; + } + + r = bus_setup_api(m, bus); + if (r < 0) { + log_error_errno(r, "Failed to set up API bus: %m"); + return 0; + } + + m->api_bus = bus; + bus = NULL; + + return 0; +} + +static int bus_setup_system(Manager *m, sd_bus *bus) { + int r; + + assert(m); + assert(bus); + + /* On kdbus or if we are a user instance we get the Released message via the system bus */ + if (m->running_as == MANAGER_USER || m->kdbus_fd >= 0) { + r = sd_bus_add_match( + bus, + NULL, + "type='signal'," + "interface='org.freedesktop.systemd1.Agent'," + "member='Released'," + "path='/org/freedesktop/systemd1/agent'", + signal_agent_released, m); + if (r < 0) + log_warning_errno(r, "Failed to register Released match on system bus: %m"); + } + + log_debug("Successfully connected to system bus."); + return 0; +} + +static int bus_init_system(Manager *m) { + _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; + int r; + + if (m->system_bus) + return 0; + + /* The API and system bus is the same if we are running in system mode */ + if (m->running_as == MANAGER_SYSTEM && m->api_bus) { + m->system_bus = sd_bus_ref(m->api_bus); + return 0; + } + + r = sd_bus_open_system(&bus); + if (r < 0) { + log_debug("Failed to connect to system bus, retrying later..."); + return 0; + } + + r = bus_setup_disconnected_match(m, bus); + if (r < 0) + return 0; + + r = sd_bus_attach_event(bus, m->event, SD_EVENT_PRIORITY_NORMAL); + if (r < 0) { + log_error_errno(r, "Failed to attach system bus to event loop: %m"); + return 0; + } + + r = bus_setup_system(m, bus); + if (r < 0) { + log_error_errno(r, "Failed to set up system bus: %m"); + return 0; + } + + m->system_bus = bus; + bus = NULL; + + return 0; +} + +static int bus_init_private(Manager *m) { + _cleanup_close_ int fd = -1; + union sockaddr_union sa = { + .un.sun_family = AF_UNIX + }; + sd_event_source *s; + socklen_t salen; + int r; + + assert(m); + + if (m->private_listen_fd >= 0) + return 0; + + /* We don't need the private socket if we have kdbus */ + if (m->kdbus_fd >= 0) + return 0; + + if (m->running_as == MANAGER_SYSTEM) { + + /* We want the private bus only when running as init */ + if (getpid() != 1) + return 0; + + strcpy(sa.un.sun_path, "/run/systemd/private"); + salen = offsetof(union sockaddr_union, un.sun_path) + strlen("/run/systemd/private"); + } else { + size_t left = sizeof(sa.un.sun_path); + char *p = sa.un.sun_path; + const char *e; + + e = secure_getenv("XDG_RUNTIME_DIR"); + if (!e) { + log_error("Failed to determine XDG_RUNTIME_DIR"); + return -EHOSTDOWN; + } + + left = strpcpy(&p, left, e); + left = strpcpy(&p, left, "/systemd/private"); + + salen = sizeof(sa.un) - left; + } + + (void) mkdir_parents_label(sa.un.sun_path, 0755); + (void) unlink(sa.un.sun_path); + + fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (fd < 0) + return log_error_errno(errno, "Failed to allocate private socket: %m"); + + r = bind(fd, &sa.sa, salen); + if (r < 0) + return log_error_errno(errno, "Failed to bind private socket: %m"); + + r = listen(fd, SOMAXCONN); + if (r < 0) + return log_error_errno(errno, "Failed to make private socket listening: %m"); + + r = sd_event_add_io(m->event, &s, fd, EPOLLIN, bus_on_connection, m); + if (r < 0) + return log_error_errno(r, "Failed to allocate event source: %m"); + + (void) sd_event_source_set_description(s, "bus-connection"); + + m->private_listen_fd = fd; + m->private_listen_event_source = s; + fd = -1; + + log_debug("Successfully created private D-Bus server."); + + return 0; +} + +int bus_init(Manager *m, bool try_bus_connect) { + int r; + + if (try_bus_connect) { + r = bus_init_system(m); + if (r < 0) + return r; + + r = bus_init_api(m); + if (r < 0) + return r; + } + + r = bus_init_private(m); + if (r < 0) + return r; + + return 0; +} + +static void destroy_bus(Manager *m, sd_bus **bus) { + Iterator i; + Job *j; + + assert(m); + assert(bus); + + if (!*bus) + return; + + /* Get rid of tracked clients on this bus */ + if (m->subscribed && sd_bus_track_get_bus(m->subscribed) == *bus) + m->subscribed = sd_bus_track_unref(m->subscribed); + + HASHMAP_FOREACH(j, m->jobs, i) + if (j->clients && sd_bus_track_get_bus(j->clients) == *bus) + j->clients = sd_bus_track_unref(j->clients); + + /* Get rid of queued message on this bus */ + if (m->queued_message && sd_bus_message_get_bus(m->queued_message) == *bus) + m->queued_message = sd_bus_message_unref(m->queued_message); + + /* Possibly flush unwritten data, but only if we are + * unprivileged, since we don't want to sync here */ + if (m->running_as != MANAGER_SYSTEM) + sd_bus_flush(*bus); + + /* And destroy the object */ + sd_bus_close(*bus); + *bus = sd_bus_unref(*bus); +} + +void bus_done(Manager *m) { + sd_bus *b; + + assert(m); + + if (m->api_bus) + destroy_bus(m, &m->api_bus); + if (m->system_bus) + destroy_bus(m, &m->system_bus); + while ((b = set_steal_first(m->private_buses))) + destroy_bus(m, &b); + + m->private_buses = set_free(m->private_buses); + + m->subscribed = sd_bus_track_unref(m->subscribed); + m->deserialized_subscribed = strv_free(m->deserialized_subscribed); + + if (m->private_listen_event_source) + m->private_listen_event_source = sd_event_source_unref(m->private_listen_event_source); + + m->private_listen_fd = safe_close(m->private_listen_fd); + + bus_verify_polkit_async_registry_free(m->polkit_registry); +} + +int bus_fdset_add_all(Manager *m, FDSet *fds) { + Iterator i; + sd_bus *b; + int fd; + + assert(m); + assert(fds); + + /* When we are about to reexecute we add all D-Bus fds to the + * set to pass over to the newly executed systemd. They won't + * be used there however, except thatt they are closed at the + * very end of deserialization, those making it possible for + * clients to synchronously wait for systemd to reexec by + * simply waiting for disconnection */ + + if (m->api_bus) { + fd = sd_bus_get_fd(m->api_bus); + if (fd >= 0) { + fd = fdset_put_dup(fds, fd); + if (fd < 0) + return fd; + } + } + + SET_FOREACH(b, m->private_buses, i) { + fd = sd_bus_get_fd(b); + if (fd >= 0) { + fd = fdset_put_dup(fds, fd); + if (fd < 0) + return fd; + } + } + + /* We don't offer any APIs on the system bus (well, unless it + * is the same as the API bus) hence we don't bother with it + * here */ + + return 0; +} + +int bus_foreach_bus( + Manager *m, + sd_bus_track *subscribed2, + int (*send_message)(sd_bus *bus, void *userdata), + void *userdata) { + + Iterator i; + sd_bus *b; + int r, ret = 0; + + /* Send to all direct buses, unconditionally */ + SET_FOREACH(b, m->private_buses, i) { + r = send_message(b, userdata); + if (r < 0) + ret = r; + } + + /* Send to API bus, but only if somebody is subscribed */ + if (sd_bus_track_count(m->subscribed) > 0 || + sd_bus_track_count(subscribed2) > 0) { + r = send_message(m->api_bus, userdata); + if (r < 0) + ret = r; + } + + return ret; +} + +void bus_track_serialize(sd_bus_track *t, FILE *f) { + const char *n; + + assert(f); + + for (n = sd_bus_track_first(t); n; n = sd_bus_track_next(t)) + fprintf(f, "subscribed=%s\n", n); +} + +int bus_track_deserialize_item(char ***l, const char *line) { + const char *e; + int r; + + assert(l); + assert(line); + + e = startswith(line, "subscribed="); + if (!e) + return 0; + + r = strv_extend(l, e); + if (r < 0) + return r; + + return 1; +} + +int bus_track_coldplug(Manager *m, sd_bus_track **t, char ***l) { + int r = 0; + + assert(m); + assert(t); + assert(l); + + if (!strv_isempty(*l) && m->api_bus) { + char **i; + + if (!*t) { + r = sd_bus_track_new(m->api_bus, t, NULL, NULL); + if (r < 0) + return r; + } + + r = 0; + STRV_FOREACH(i, *l) { + int k; + + k = sd_bus_track_add_name(*t, *i); + if (k < 0) + r = k; + } + } + + *l = strv_free(*l); + + return r; +} + +int bus_verify_manage_units_async(Manager *m, sd_bus_message *call, sd_bus_error *error) { + return bus_verify_polkit_async(call, CAP_SYS_ADMIN, "org.freedesktop.systemd1.manage-units", NULL, false, UID_INVALID, &m->polkit_registry, error); +} + +int bus_verify_manage_unit_files_async(Manager *m, sd_bus_message *call, sd_bus_error *error) { + return bus_verify_polkit_async(call, CAP_SYS_ADMIN, "org.freedesktop.systemd1.manage-unit-files", NULL, false, UID_INVALID, &m->polkit_registry, error); +} + +int bus_verify_reload_daemon_async(Manager *m, sd_bus_message *call, sd_bus_error *error) { + return bus_verify_polkit_async(call, CAP_SYS_ADMIN, "org.freedesktop.systemd1.reload-daemon", NULL, false, UID_INVALID, &m->polkit_registry, error); +} + +int bus_verify_set_environment_async(Manager *m, sd_bus_message *call, sd_bus_error *error) { + return bus_verify_polkit_async(call, CAP_SYS_ADMIN, "org.freedesktop.systemd1.set-environment", NULL, false, UID_INVALID, &m->polkit_registry, error); +} |