Adding upstream version 247.3.upstream/247.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 700 insertions, 0 deletions

diff --git a/src/core/scope.c b/src/core/scope.c
new file mode 100644
index 0000000..5448d44
--- /dev/null
+++ b/src/core/scope.c
@@ -0,0 +1,700 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "dbus-scope.h"
+#include "dbus-unit.h"
+#include "load-dropin.h"
+#include "log.h"
+#include "process-util.h"
+#include "scope.h"
+#include "serialize.h"
+#include "special.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "strv.h"
+#include "unit-name.h"
+#include "unit.h"
+
+static const UnitActiveState state_translation_table[_SCOPE_STATE_MAX] = {
+        [SCOPE_DEAD] = UNIT_INACTIVE,
+        [SCOPE_RUNNING] = UNIT_ACTIVE,
+        [SCOPE_ABANDONED] = UNIT_ACTIVE,
+        [SCOPE_STOP_SIGTERM] = UNIT_DEACTIVATING,
+        [SCOPE_STOP_SIGKILL] = UNIT_DEACTIVATING,
+        [SCOPE_FAILED] = UNIT_FAILED
+};
+
+static int scope_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata);
+
+static void scope_init(Unit *u) {
+        Scope *s = SCOPE(u);
+
+        assert(u);
+        assert(u->load_state == UNIT_STUB);
+
+        s->runtime_max_usec = USEC_INFINITY;
+        s->timeout_stop_usec = u->manager->default_timeout_stop_usec;
+        u->ignore_on_isolate = true;
+}
+
+static void scope_done(Unit *u) {
+        Scope *s = SCOPE(u);
+
+        assert(u);
+
+        s->controller = mfree(s->controller);
+        s->controller_track = sd_bus_track_unref(s->controller_track);
+
+        s->timer_event_source = sd_event_source_unref(s->timer_event_source);
+}
+
+static int scope_arm_timer(Scope *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,
+                        scope_dispatch_timer, s);
+        if (r < 0)
+                return r;
+
+        (void) sd_event_source_set_description(s->timer_event_source, "scope-timer");
+
+        return 0;
+}
+
+static void scope_set_state(Scope *s, ScopeState state) {
+        ScopeState 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, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
+                s->timer_event_source = sd_event_source_unref(s->timer_event_source);
+
+        if (IN_SET(state, SCOPE_DEAD, SCOPE_FAILED)) {
+                unit_unwatch_all_pids(UNIT(s));
+                unit_dequeue_rewatch_pids(UNIT(s));
+        }
+
+        if (state != old_state)
+                log_debug("%s changed %s -> %s", UNIT(s)->id, scope_state_to_string(old_state), scope_state_to_string(state));
+
+        unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], 0);
+}
+
+static int scope_add_default_dependencies(Scope *s) {
+        int r;
+
+        assert(s);
+
+        if (!UNIT(s)->default_dependencies)
+                return 0;
+
+        /* Make sure scopes are unloaded on shutdown */
+        r = unit_add_two_dependencies_by_name(
+                        UNIT(s),
+                        UNIT_BEFORE, UNIT_CONFLICTS,
+                        SPECIAL_SHUTDOWN_TARGET, true,
+                        UNIT_DEPENDENCY_DEFAULT);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+static int scope_verify(Scope *s) {
+        assert(s);
+        assert(UNIT(s)->load_state == UNIT_LOADED);
+
+        if (set_isempty(UNIT(s)->pids) &&
+            !MANAGER_IS_RELOADING(UNIT(s)->manager) &&
+            !unit_has_name(UNIT(s), SPECIAL_INIT_SCOPE)) {
+                log_unit_error(UNIT(s), "Scope has no PIDs. Refusing.");
+                return -ENOENT;
+        }
+
+        return 0;
+}
+
+static int scope_load_init_scope(Unit *u) {
+        assert(u);
+
+        if (!unit_has_name(u, SPECIAL_INIT_SCOPE))
+                return 0;
+
+        u->transient = true;
+        u->perpetual = true;
+
+        /* init.scope is a bit special, as it has to stick around forever. Because of its special semantics we
+         * synthesize it here, instead of relying on the unit file on disk. */
+
+        u->default_dependencies = false;
+
+        /* Prettify things, if we can. */
+        if (!u->description)
+                u->description = strdup("System and Service Manager");
+        if (!u->documentation)
+                (void) strv_extend(&u->documentation, "man:systemd(1)");
+
+        return 1;
+}
+
+static int scope_add_extras(Scope *s) {
+        int r;
+
+        r = unit_patch_contexts(UNIT(s));
+        if (r < 0)
+                return r;
+
+        r = unit_set_default_slice(UNIT(s));
+        if (r < 0)
+                return r;
+
+        return scope_add_default_dependencies(s);
+}
+
+static int scope_load(Unit *u) {
+        Scope *s = SCOPE(u);
+        int r;
+
+        assert(s);
+        assert(u->load_state == UNIT_STUB);
+
+        if (!u->transient && !MANAGER_IS_RELOADING(u->manager))
+                /* Refuse to load non-transient scope units, but allow them while reloading. */
+                return -ENOENT;
+
+        r = scope_load_init_scope(u);
+        if (r < 0)
+                return r;
+
+        r = unit_load_fragment_and_dropin(u, false);
+        if (r < 0)
+                return r;
+
+        if (u->load_state != UNIT_LOADED)
+                return 0;
+
+        r = scope_add_extras(s);
+        if (r < 0)
+                return r;
+
+        return scope_verify(s);
+}
+
+static usec_t scope_coldplug_timeout(Scope *s) {
+        assert(s);
+
+        switch (s->deserialized_state) {
+
+        case SCOPE_RUNNING:
+                return usec_add(UNIT(s)->active_enter_timestamp.monotonic, s->runtime_max_usec);
+
+        case SCOPE_STOP_SIGKILL:
+        case SCOPE_STOP_SIGTERM:
+                return usec_add(UNIT(s)->state_change_timestamp.monotonic, s->timeout_stop_usec);
+
+        default:
+                return USEC_INFINITY;
+        }
+}
+
+static int scope_coldplug(Unit *u) {
+        Scope *s = SCOPE(u);
+        int r;
+
+        assert(s);
+        assert(s->state == SCOPE_DEAD);
+
+        if (s->deserialized_state == s->state)
+                return 0;
+
+        r = scope_arm_timer(s, scope_coldplug_timeout(s));
+        if (r < 0)
+                return r;
+
+        if (!IN_SET(s->deserialized_state, SCOPE_DEAD, SCOPE_FAILED)) {
+                if (u->pids) {
+                        void *pidp;
+
+                        SET_FOREACH(pidp, u->pids) {
+                                r = unit_watch_pid(u, PTR_TO_PID(pidp), false);
+                                if (r < 0 && r != -EEXIST)
+                                        return r;
+                        }
+                } else
+                        (void) unit_enqueue_rewatch_pids(u);
+        }
+
+        bus_scope_track_controller(s);
+
+        scope_set_state(s, s->deserialized_state);
+        return 0;
+}
+
+static void scope_dump(Unit *u, FILE *f, const char *prefix) {
+        Scope *s = SCOPE(u);
+        char buf_runtime[FORMAT_TIMESPAN_MAX];
+
+        assert(s);
+        assert(f);
+
+        fprintf(f,
+                "%sScope State: %s\n"
+                "%sResult: %s\n"
+                "%sRuntimeMaxSec: %s\n",
+                prefix, scope_state_to_string(s->state),
+                prefix, scope_result_to_string(s->result),
+                prefix, format_timespan(buf_runtime, sizeof(buf_runtime), s->runtime_max_usec, USEC_PER_SEC));
+
+        cgroup_context_dump(UNIT(s), f, prefix);
+        kill_context_dump(&s->kill_context, f, prefix);
+}
+
+static void scope_enter_dead(Scope *s, ScopeResult f) {
+        assert(s);
+
+        if (s->result == SCOPE_SUCCESS)
+                s->result = f;
+
+        unit_log_result(UNIT(s), s->result == SCOPE_SUCCESS, scope_result_to_string(s->result));
+        scope_set_state(s, s->result != SCOPE_SUCCESS ? SCOPE_FAILED : SCOPE_DEAD);
+}
+
+static void scope_enter_signal(Scope *s, ScopeState state, ScopeResult f) {
+        bool skip_signal = false;
+        int r;
+
+        assert(s);
+
+        if (s->result == SCOPE_SUCCESS)
+                s->result = f;
+
+        /* Before sending any signal, make sure we track all members of this cgroup */
+        (void) unit_watch_all_pids(UNIT(s));
+
+        /* Also, enqueue a job that we recheck all our PIDs a bit later, given that it's likely some processes have
+         * died now */
+        (void) unit_enqueue_rewatch_pids(UNIT(s));
+
+        /* If we have a controller set let's ask the controller nicely to terminate the scope, instead of us going
+         * directly into SIGTERM berserk mode */
+        if (state == SCOPE_STOP_SIGTERM)
+                skip_signal = bus_scope_send_request_stop(s) > 0;
+
+        if (skip_signal)
+                r = 1; /* wait */
+        else {
+                r = unit_kill_context(
+                                UNIT(s),
+                                &s->kill_context,
+                                state != SCOPE_STOP_SIGTERM ? KILL_KILL :
+                                s->was_abandoned            ? KILL_TERMINATE_AND_LOG :
+                                                              KILL_TERMINATE,
+                                -1, -1, false);
+                if (r < 0)
+                        goto fail;
+        }
+
+        if (r > 0) {
+                r = scope_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_stop_usec));
+                if (r < 0)
+                        goto fail;
+
+                scope_set_state(s, state);
+        } else if (state == SCOPE_STOP_SIGTERM)
+                scope_enter_signal(s, SCOPE_STOP_SIGKILL, SCOPE_SUCCESS);
+        else
+                scope_enter_dead(s, SCOPE_SUCCESS);
+
+        return;
+
+fail:
+        log_unit_warning_errno(UNIT(s), r, "Failed to kill processes: %m");
+
+        scope_enter_dead(s, SCOPE_FAILURE_RESOURCES);
+}
+
+static int scope_start(Unit *u) {
+        Scope *s = SCOPE(u);
+        int r;
+
+        assert(s);
+
+        if (unit_has_name(u, SPECIAL_INIT_SCOPE))
+                return -EPERM;
+
+        if (s->state == SCOPE_FAILED)
+                return -EPERM;
+
+        /* We can't fulfill this right now, please try again later */
+        if (IN_SET(s->state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
+                return -EAGAIN;
+
+        assert(s->state == SCOPE_DEAD);
+
+        if (!u->transient && !MANAGER_IS_RELOADING(u->manager))
+                return -ENOENT;
+
+        (void) bus_scope_track_controller(s);
+
+        r = unit_acquire_invocation_id(u);
+        if (r < 0)
+                return r;
+
+        (void) unit_realize_cgroup(u);
+        (void) unit_reset_accounting(u);
+
+        unit_export_state_files(u);
+
+        r = unit_attach_pids_to_cgroup(u, u->pids, NULL);
+        if (r < 0) {
+                log_unit_warning_errno(u, r, "Failed to add PIDs to scope's control group: %m");
+                scope_enter_dead(s, SCOPE_FAILURE_RESOURCES);
+                return r;
+        }
+
+        s->result = SCOPE_SUCCESS;
+
+        scope_set_state(s, SCOPE_RUNNING);
+
+        /* Set the maximum runtime timeout. */
+        scope_arm_timer(s, usec_add(UNIT(s)->active_enter_timestamp.monotonic, s->runtime_max_usec));
+
+        /* On unified we use proper notifications hence we can unwatch the PIDs
+         * we just attached to the scope. This can also be done on legacy as
+         * we're going to update the list of the processes we watch with the
+         * PIDs currently in the scope anyway. */
+        unit_unwatch_all_pids(u);
+
+        /* Start watching the PIDs currently in the scope (legacy hierarchy only) */
+        (void) unit_enqueue_rewatch_pids(u);
+        return 1;
+}
+
+static int scope_stop(Unit *u) {
+        Scope *s = SCOPE(u);
+
+        assert(s);
+
+        if (IN_SET(s->state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
+                return 0;
+
+        assert(IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED));
+
+        scope_enter_signal(s, SCOPE_STOP_SIGTERM, SCOPE_SUCCESS);
+        return 1;
+}
+
+static void scope_reset_failed(Unit *u) {
+        Scope *s = SCOPE(u);
+
+        assert(s);
+
+        if (s->state == SCOPE_FAILED)
+                scope_set_state(s, SCOPE_DEAD);
+
+        s->result = SCOPE_SUCCESS;
+}
+
+static int scope_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) {
+        return unit_kill_common(u, who, signo, -1, -1, error);
+}
+
+static int scope_get_timeout(Unit *u, usec_t *timeout) {
+        Scope *s = SCOPE(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;
+}
+
+static int scope_serialize(Unit *u, FILE *f, FDSet *fds) {
+        Scope *s = SCOPE(u);
+        void *pidp;
+
+        assert(s);
+        assert(f);
+        assert(fds);
+
+        (void) serialize_item(f, "state", scope_state_to_string(s->state));
+        (void) serialize_bool(f, "was-abandoned", s->was_abandoned);
+
+        if (s->controller)
+                (void) serialize_item(f, "controller", s->controller);
+
+        SET_FOREACH(pidp, u->pids)
+                serialize_item_format(f, "pids", PID_FMT, PTR_TO_PID(pidp));
+
+        return 0;
+}
+
+static int scope_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
+        Scope *s = SCOPE(u);
+        int r;
+
+        assert(u);
+        assert(key);
+        assert(value);
+        assert(fds);
+
+        if (streq(key, "state")) {
+                ScopeState state;
+
+                state = scope_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, "was-abandoned")) {
+                int k;
+
+                k = parse_boolean(value);
+                if (k < 0)
+                        log_unit_debug(u, "Failed to parse boolean value: %s", value);
+                else
+                        s->was_abandoned = k;
+        } else if (streq(key, "controller")) {
+
+                r = free_and_strdup(&s->controller, value);
+                if (r < 0)
+                        return log_oom();
+
+        } else if (streq(key, "pids")) {
+                pid_t pid;
+
+                if (parse_pid(value, &pid) < 0)
+                        log_unit_debug(u, "Failed to parse pids value: %s", value);
+                else {
+                        r = set_ensure_allocated(&u->pids, NULL);
+                        if (r < 0)
+                                return r;
+
+                        r = set_put(u->pids, PID_TO_PTR(pid));
+                        if (r < 0)
+                                return r;
+                }
+        } else
+                log_unit_debug(u, "Unknown serialization key: %s", key);
+
+        return 0;
+}
+
+static void scope_notify_cgroup_empty_event(Unit *u) {
+        Scope *s = SCOPE(u);
+        assert(u);
+
+        log_unit_debug(u, "cgroup is empty");
+
+        if (IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
+                scope_enter_dead(s, SCOPE_SUCCESS);
+
+        /* If the cgroup empty notification comes when the unit is not active, we must have failed to clean
+         * up the cgroup earlier and should do it now. */
+        if (IN_SET(s->state, SCOPE_DEAD, SCOPE_FAILED))
+                unit_prune_cgroup(u);
+}
+
+static void scope_sigchld_event(Unit *u, pid_t pid, int code, int status) {
+        assert(u);
+
+        /* If we get a SIGCHLD event for one of the processes we were interested in, then we look for others to
+         * watch, under the assumption that we'll sooner or later get a SIGCHLD for them, as the original
+         * process we watched was probably the parent of them, and they are hence now our children. */
+
+        (void) unit_enqueue_rewatch_pids(u);
+}
+
+static int scope_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) {
+        Scope *s = SCOPE(userdata);
+
+        assert(s);
+        assert(s->timer_event_source == source);
+
+        switch (s->state) {
+
+        case SCOPE_RUNNING:
+                log_unit_warning(UNIT(s), "Scope reached runtime time limit. Stopping.");
+                scope_enter_signal(s, SCOPE_STOP_SIGTERM, SCOPE_FAILURE_TIMEOUT);
+                break;
+
+        case SCOPE_STOP_SIGTERM:
+                if (s->kill_context.send_sigkill) {
+                        log_unit_warning(UNIT(s), "Stopping timed out. Killing.");
+                        scope_enter_signal(s, SCOPE_STOP_SIGKILL, SCOPE_FAILURE_TIMEOUT);
+                } else {
+                        log_unit_warning(UNIT(s), "Stopping timed out. Skipping SIGKILL.");
+                        scope_enter_dead(s, SCOPE_FAILURE_TIMEOUT);
+                }
+
+                break;
+
+        case SCOPE_STOP_SIGKILL:
+                log_unit_warning(UNIT(s), "Still around after SIGKILL. Ignoring.");
+                scope_enter_dead(s, SCOPE_FAILURE_TIMEOUT);
+                break;
+
+        default:
+                assert_not_reached("Timeout at wrong time.");
+        }
+
+        return 0;
+}
+
+int scope_abandon(Scope *s) {
+        assert(s);
+
+        if (unit_has_name(UNIT(s), SPECIAL_INIT_SCOPE))
+                return -EPERM;
+
+        if (!IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED))
+                return -ESTALE;
+
+        s->was_abandoned = true;
+
+        s->controller = mfree(s->controller);
+        s->controller_track = sd_bus_track_unref(s->controller_track);
+
+        scope_set_state(s, SCOPE_ABANDONED);
+
+        /* The client is no longer watching the remaining processes, so let's step in here, under the assumption that
+         * the remaining processes will be sooner or later reassigned to us as parent. */
+        (void) unit_enqueue_rewatch_pids(UNIT(s));
+
+        return 0;
+}
+
+_pure_ static UnitActiveState scope_active_state(Unit *u) {
+        assert(u);
+
+        return state_translation_table[SCOPE(u)->state];
+}
+
+_pure_ static const char *scope_sub_state_to_string(Unit *u) {
+        assert(u);
+
+        return scope_state_to_string(SCOPE(u)->state);
+}
+
+static void scope_enumerate_perpetual(Manager *m) {
+        Unit *u;
+        int r;
+
+        assert(m);
+
+        /* Let's unconditionally add the "init.scope" special unit
+         * that encapsulates PID 1. Note that PID 1 already is in the
+         * cgroup for this, we hence just need to allocate the object
+         * for it and that's it. */
+
+        u = manager_get_unit(m, SPECIAL_INIT_SCOPE);
+        if (!u) {
+                r = unit_new_for_name(m, sizeof(Scope), SPECIAL_INIT_SCOPE, &u);
+                if (r < 0)  {
+                        log_error_errno(r, "Failed to allocate the special " SPECIAL_INIT_SCOPE " unit: %m");
+                        return;
+                }
+        }
+
+        u->transient = true;
+        u->perpetual = true;
+        SCOPE(u)->deserialized_state = SCOPE_RUNNING;
+
+        unit_add_to_load_queue(u);
+        unit_add_to_dbus_queue(u);
+}
+
+static const char* const scope_result_table[_SCOPE_RESULT_MAX] = {
+        [SCOPE_SUCCESS] = "success",
+        [SCOPE_FAILURE_RESOURCES] = "resources",
+        [SCOPE_FAILURE_TIMEOUT] = "timeout",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(scope_result, ScopeResult);
+
+const UnitVTable scope_vtable = {
+        .object_size = sizeof(Scope),
+        .cgroup_context_offset = offsetof(Scope, cgroup_context),
+        .kill_context_offset = offsetof(Scope, kill_context),
+
+        .sections =
+                "Unit\0"
+                "Scope\0"
+                "Install\0",
+        .private_section = "Scope",
+
+        .can_transient = true,
+        .can_delegate = true,
+        .can_fail = true,
+        .once_only = true,
+        .can_set_managed_oom = true,
+
+        .init = scope_init,
+        .load = scope_load,
+        .done = scope_done,
+
+        .coldplug = scope_coldplug,
+
+        .dump = scope_dump,
+
+        .start = scope_start,
+        .stop = scope_stop,
+
+        .kill = scope_kill,
+
+        .freeze = unit_freeze_vtable_common,
+        .thaw = unit_thaw_vtable_common,
+
+        .get_timeout = scope_get_timeout,
+
+        .serialize = scope_serialize,
+        .deserialize_item = scope_deserialize_item,
+
+        .active_state = scope_active_state,
+        .sub_state_to_string = scope_sub_state_to_string,
+
+        .sigchld_event = scope_sigchld_event,
+
+        .reset_failed = scope_reset_failed,
+
+        .notify_cgroup_empty = scope_notify_cgroup_empty_event,
+
+        .bus_set_property = bus_scope_set_property,
+        .bus_commit_properties = bus_scope_commit_properties,
+
+        .enumerate_perpetual = scope_enumerate_perpetual,
+};