chiark / gitweb /
core: add bus API and systemctl commands for altering cgroup parameters during runtime
[elogind.git] / src / core / dbus-unit.c
index 83ee018ff3dd445484e68f2a7b2bb2f1e3b5614a..c7bf043764e898d96e25702ae7ea1dcf7124a8d6 100644 (file)
@@ -27,6 +27,9 @@
 #include "bus-errors.h"
 #include "dbus-common.h"
 #include "selinux-access.h"
+#include "cgroup-util.h"
+#include "strv.h"
+#include "path-util.h"
 
 const char bus_unit_interface[] _introspect_("Unit") = BUS_UNIT_INTERFACE;
 
@@ -235,7 +238,7 @@ static int bus_unit_append_can_isolate(DBusMessageIter *i, const char *property,
 static int bus_unit_append_job(DBusMessageIter *i, const char *property, void *data) {
         Unit *u = data;
         DBusMessageIter sub;
-        char *p;
+        _cleanup_free_ char *p = NULL;
 
         assert(i);
         assert(property);
@@ -246,14 +249,13 @@ static int bus_unit_append_job(DBusMessageIter *i, const char *property, void *d
 
         if (u->job) {
 
-                if (!(p = job_dbus_path(u->job)))
+                p = job_dbus_path(u->job);
+                if (!p)
                         return -ENOMEM;
 
                 if (!dbus_message_iter_append_basic(&sub, DBUS_TYPE_UINT32, &u->job->id) ||
-                    !dbus_message_iter_append_basic(&sub, DBUS_TYPE_OBJECT_PATH, &p)) {
-                        free(p);
+                    !dbus_message_iter_append_basic(&sub, DBUS_TYPE_OBJECT_PATH, &p))
                         return -ENOMEM;
-                }
         } else {
                 uint32_t id = 0;
 
@@ -261,18 +263,15 @@ static int bus_unit_append_job(DBusMessageIter *i, const char *property, void *d
                  * data. Since we need to fill in a valid path we
                  * simple point to ourselves. */
 
-                if (!(p = unit_dbus_path(u)))
+                p = unit_dbus_path(u);
+                if (!p)
                         return -ENOMEM;
 
                 if (!dbus_message_iter_append_basic(&sub, DBUS_TYPE_UINT32, &id) ||
-                    !dbus_message_iter_append_basic(&sub, DBUS_TYPE_OBJECT_PATH, &p)) {
-                        free(p);
+                    !dbus_message_iter_append_basic(&sub, DBUS_TYPE_OBJECT_PATH, &p))
                         return -ENOMEM;
-                }
         }
 
-        free(p);
-
         if (!dbus_message_iter_close_container(i, &sub))
                 return -ENOMEM;
 
@@ -289,8 +288,10 @@ static int bus_unit_append_default_cgroup(DBusMessageIter *i, const char *proper
         assert(property);
         assert(u);
 
-        if ((cgb = unit_get_default_cgroup(u))) {
-                if (!(t = cgroup_bonding_to_string(cgb)))
+        cgb = unit_get_default_cgroup(u);
+        if (cgb) {
+                t = cgroup_bonding_to_string(cgb);
+                if (!t)
                         return -ENOMEM;
         } else
                 t = (char*) "";
@@ -312,15 +313,14 @@ static int bus_unit_append_cgroups(DBusMessageIter *i, const char *property, voi
                 return -ENOMEM;
 
         LIST_FOREACH(by_unit, cgb, u->cgroup_bondings) {
-                char *t;
+                char _cleanup_free_ *t = NULL;
                 bool success;
 
-                if (!(t = cgroup_bonding_to_string(cgb)))
+                t = cgroup_bonding_to_string(cgb);
+                if (!t)
                         return -ENOMEM;
 
                 success = dbus_message_iter_append_basic(&sub, DBUS_TYPE_STRING, &t);
-                free(t);
-
                 if (!success)
                         return -ENOMEM;
         }
@@ -340,7 +340,7 @@ static int bus_unit_append_cgroup_attrs(DBusMessageIter *i, const char *property
                 return -ENOMEM;
 
         LIST_FOREACH(by_unit, a, u->cgroup_attributes) {
-                char *v = NULL;
+                char _cleanup_free_ *v = NULL;
                 bool success;
 
                 if (a->map_callback)
@@ -352,9 +352,6 @@ static int bus_unit_append_cgroup_attrs(DBusMessageIter *i, const char *property
                         dbus_message_iter_append_basic(&sub2, DBUS_TYPE_STRING, &a->name) &&
                         dbus_message_iter_append_basic(&sub2, DBUS_TYPE_STRING, v ? &v : &a->value) &&
                         dbus_message_iter_close_container(&sub, &sub2);
-
-                free(v);
-
                 if (!success)
                         return -ENOMEM;
         }
@@ -474,6 +471,69 @@ static DBusHandlerResult bus_unit_message_dispatch(Unit *u, DBusConnection *conn
                 if (!reply)
                         goto oom;
 
+        } else if (streq_ptr(dbus_message_get_member(message), "SetControlGroups")) {
+                DBusMessageIter iter;
+
+                SELINUX_UNIT_ACCESS_CHECK(u, connection, message, "start");
+
+                if (!dbus_message_iter_init(message, &iter))
+                        goto oom;
+
+                r = bus_unit_cgroup_set(u, &iter);
+                if (r < 0)
+                        return bus_send_error_reply(connection, message, NULL, r);
+
+                reply = dbus_message_new_method_return(message);
+                if (!reply)
+                        goto oom;
+
+        } else if (streq_ptr(dbus_message_get_member(message), "UnsetControlGroups")) {
+                DBusMessageIter iter;
+
+                SELINUX_UNIT_ACCESS_CHECK(u, connection, message, "stop");
+
+                if (!dbus_message_iter_init(message, &iter))
+                        goto oom;
+
+                r = bus_unit_cgroup_set(u, &iter);
+                if (r < 0)
+                        return bus_send_error_reply(connection, message, NULL, r);
+
+                reply = dbus_message_new_method_return(message);
+                if (!reply)
+                        goto oom;
+        } else if (streq_ptr(dbus_message_get_member(message), "SetControlGroupAttributes")) {
+                DBusMessageIter iter;
+
+                SELINUX_UNIT_ACCESS_CHECK(u, connection, message, "start");
+
+                if (!dbus_message_iter_init(message, &iter))
+                        goto oom;
+
+                r = bus_unit_cgroup_attribute_set(u, &iter);
+                if (r < 0)
+                        return bus_send_error_reply(connection, message, NULL, r);
+
+                reply = dbus_message_new_method_return(message);
+                if (!reply)
+                        goto oom;
+
+        } else if (streq_ptr(dbus_message_get_member(message), "UnsetControlGroupAttributes")) {
+                DBusMessageIter iter;
+
+                SELINUX_UNIT_ACCESS_CHECK(u, connection, message, "stop");
+
+                if (!dbus_message_iter_init(message, &iter))
+                        goto oom;
+
+                r = bus_unit_cgroup_attribute_unset(u, &iter);
+                if (r < 0)
+                        return bus_send_error_reply(connection, message, NULL, r);
+
+                reply = dbus_message_new_method_return(message);
+                if (!reply)
+                        goto oom;
+
         } else if (UNIT_VTABLE(u)->bus_message_handler)
                 return UNIT_VTABLE(u)->bus_message_handler(u, connection, message);
         else
@@ -619,8 +679,8 @@ const DBusObjectPathVTable bus_unit_vtable = {
 };
 
 void bus_unit_send_change_signal(Unit *u) {
-        char *p = NULL;
-        DBusMessage *m = NULL;
+        _cleanup_free_ char *p = NULL;
+        _cleanup_dbus_message_unref_ DBusMessage *m = NULL;
 
         assert(u);
 
@@ -637,7 +697,8 @@ void bus_unit_send_change_signal(Unit *u) {
                 return;
         }
 
-        if (!(p = unit_dbus_path(u)))
+        p = unit_dbus_path(u);
+        if (!p)
                 goto oom;
 
         if (u->sent_dbus_new_signal) {
@@ -648,9 +709,10 @@ void bus_unit_send_change_signal(Unit *u) {
 
                 if (UNIT_VTABLE(u)->bus_invalidating_properties) {
 
-                        if (!(m = bus_properties_changed_new(p,
-                                                             UNIT_VTABLE(u)->bus_interface,
-                                                             UNIT_VTABLE(u)->bus_invalidating_properties)))
+                        m = bus_properties_changed_new(p,
+                                                       UNIT_VTABLE(u)->bus_interface,
+                                                       UNIT_VTABLE(u)->bus_invalidating_properties);
+                        if (!m)
                                 goto oom;
 
                         if (bus_broadcast(u->manager, m) < 0)
@@ -659,13 +721,18 @@ void bus_unit_send_change_signal(Unit *u) {
                         dbus_message_unref(m);
                 }
 
-                if (!(m = bus_properties_changed_new(p, "org.freedesktop.systemd1.Unit", INVALIDATING_PROPERTIES)))
+                m = bus_properties_changed_new(p, "org.freedesktop.systemd1.Unit",
+                                               INVALIDATING_PROPERTIES);
+                if (!m)
                         goto oom;
 
         } else {
                 /* Send a new signal */
 
-                if (!(m = dbus_message_new_signal("/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", "UnitNew")))
+                m = dbus_message_new_signal("/org/freedesktop/systemd1",
+                                            "org.freedesktop.systemd1.Manager",
+                                            "UnitNew");
+                if (!m)
                         goto oom;
 
                 if (!dbus_message_append_args(m,
@@ -678,25 +745,17 @@ void bus_unit_send_change_signal(Unit *u) {
         if (bus_broadcast(u->manager, m) < 0)
                 goto oom;
 
-        free(p);
-        dbus_message_unref(m);
-
         u->sent_dbus_new_signal = true;
 
         return;
 
 oom:
-        free(p);
-
-        if (m)
-                dbus_message_unref(m);
-
-        log_error("Failed to allocate unit change/new signal.");
+        log_oom();
 }
 
 void bus_unit_send_removed_signal(Unit *u) {
-        char *p = NULL;
-        DBusMessage *m = NULL;
+        _cleanup_free_ char *p = NULL;
+        _cleanup_dbus_message_unref_ DBusMessage *m = NULL;
 
         assert(u);
 
@@ -709,10 +768,14 @@ void bus_unit_send_removed_signal(Unit *u) {
         if (!u->id)
                 return;
 
-        if (!(p = unit_dbus_path(u)))
+        p = unit_dbus_path(u);
+        if (!p)
                 goto oom;
 
-        if (!(m = dbus_message_new_signal("/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", "UnitRemoved")))
+        m = dbus_message_new_signal("/org/freedesktop/systemd1",
+                                    "org.freedesktop.systemd1.Manager",
+                                    "UnitRemoved");
+        if (!m)
                 goto oom;
 
         if (!dbus_message_append_args(m,
@@ -724,18 +787,10 @@ void bus_unit_send_removed_signal(Unit *u) {
         if (bus_broadcast(u->manager, m) < 0)
                 goto oom;
 
-        free(p);
-        dbus_message_unref(m);
-
         return;
 
 oom:
-        free(p);
-
-        if (m)
-                dbus_message_unref(m);
-
-        log_error("Failed to allocate unit remove signal.");
+        log_oom();
 }
 
 DBusHandlerResult bus_unit_queue_job(
@@ -780,7 +835,8 @@ DBusHandlerResult bus_unit_queue_job(
         if ((type == JOB_START && u->refuse_manual_start) ||
             (type == JOB_STOP && u->refuse_manual_stop) ||
             ((type == JOB_RESTART || type == JOB_TRY_RESTART) && (u->refuse_manual_start || u->refuse_manual_stop))) {
-                dbus_set_error(&error, BUS_ERROR_ONLY_BY_DEPENDENCY, "Operation refused, unit %s may be requested by dependency only.", u->id);
+                dbus_set_error(&error, BUS_ERROR_ONLY_BY_DEPENDENCY,
+                               "Operation refused, unit %s may be requested by dependency only.", u->id);
                 return bus_send_error_reply(connection, message, &error, -EPERM);
         }
 
@@ -819,6 +875,180 @@ oom:
         return DBUS_HANDLER_RESULT_NEED_MEMORY;
 }
 
+int bus_unit_cgroup_set(Unit *u, DBusMessageIter *iter) {
+        int r;
+        _cleanup_strv_free_ char **a = NULL;
+        char **name;
+
+        assert(u);
+        assert(iter);
+
+        if (!unit_get_exec_context(u))
+                return -EINVAL;
+
+        r = bus_parse_strv_iter(iter, &a);
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH(name, a) {
+                _cleanup_free_ char *controller = NULL, *old_path = NULL, *new_path = NULL;
+                CGroupBonding *b;
+
+                r = cg_split_spec(*name, &controller, &new_path);
+                if (r < 0)
+                        return r;
+
+                b = cgroup_bonding_find_list(u->cgroup_bondings, controller);
+                if (b) {
+                        old_path = strdup(b->path);
+                        if (!old_path)
+                                return -ENOMEM;
+                }
+
+                r = unit_add_cgroup_from_text(u, *name, true, &b);
+                if (r < 0)
+                        return r;
+
+                if (r > 0) {
+                        /* Try to move things to the new place, and clean up the old place */
+                        cgroup_bonding_realize(b);
+                        cgroup_bonding_migrate(b, u->cgroup_bondings);
+
+                        if (old_path)
+                                cg_trim(controller, old_path, true);
+                }
+        }
+
+        return 0;
+}
+
+int bus_unit_cgroup_unset(Unit *u, DBusMessageIter *iter) {
+        _cleanup_strv_free_ char **a = NULL;
+        char **name;
+        int r;
+
+        assert(u);
+        assert(iter);
+
+        if (!unit_get_exec_context(u))
+                return -EINVAL;
+
+        r = bus_parse_strv_iter(iter, &a);
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH(name, a) {
+                _cleanup_free_ char *controller = NULL, *path = NULL, *target = NULL;
+                CGroupBonding *b;
+
+                r = cg_split_spec(*name, &controller, &path);
+                if (r < 0)
+                        return r;
+
+                b = cgroup_bonding_find_list(u->cgroup_bondings, controller);
+                if (!b)
+                        continue;
+
+                if (path && !path_equal(path, b->path))
+                        continue;
+
+                if (b->essential)
+                        return -EINVAL;
+
+                /* Try to migrate the old group away */
+                if (cg_get_by_pid(controller, 0, &target) >= 0)
+                        cgroup_bonding_migrate_to(u->cgroup_bondings, target, false);
+
+                cgroup_bonding_free(b, true);
+        }
+
+        return 0;
+}
+
+int bus_unit_cgroup_attribute_set(Unit *u, DBusMessageIter *iter) {
+        DBusMessageIter sub, sub2;
+        int r;
+
+        assert(u);
+        assert(iter);
+
+        if (!unit_get_exec_context(u))
+                return -EINVAL;
+
+        if (dbus_message_iter_get_arg_type(iter) != DBUS_TYPE_ARRAY ||
+            dbus_message_iter_get_element_type(iter) != DBUS_TYPE_STRUCT)
+            return -EINVAL;
+
+        dbus_message_iter_recurse(iter, &sub);
+
+        while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
+                const char *name, *value;
+                CGroupAttribute *a;
+
+                assert_se(dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_STRUCT);
+
+                dbus_message_iter_recurse(&sub, &sub2);
+
+                if (bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &name, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &value, false) < 0)
+                        return -EINVAL;
+
+                dbus_message_iter_next(&sub);
+
+                r = unit_add_cgroup_attribute(u, NULL, name, value, NULL, &a);
+                if (r < 0)
+                        return r;
+
+                if (r > 0) {
+                        CGroupBonding *b;
+
+                        b = cgroup_bonding_find_list(u->cgroup_bondings, a->controller);
+                        if (!b) {
+                                /* Doesn't exist yet? Then let's add it */
+                                r = unit_add_cgroup_from_text(u, a->controller, false, &b);
+                                if (r < 0)
+                                        return r;
+
+                                if (r > 0) {
+                                        cgroup_bonding_realize(b);
+                                        cgroup_bonding_migrate(b, u->cgroup_bondings);
+                                }
+                        }
+
+                        /* Make it count */
+                        cgroup_attribute_apply(a, u->cgroup_bondings);
+                }
+        }
+
+        return 0;
+}
+
+int bus_unit_cgroup_attribute_unset(Unit *u, DBusMessageIter *iter) {
+        _cleanup_strv_free_ char **l = NULL;
+        char **name;
+        int r;
+
+        assert(u);
+        assert(iter);
+
+        if (!unit_get_exec_context(u))
+                return -EINVAL;
+
+        r = bus_parse_strv_iter(iter, &l);
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH(name, l) {
+                CGroupAttribute *a;
+
+                a = cgroup_attribute_find_list(u->cgroup_attributes, NULL, *name);
+                if (a)
+                        cgroup_attribute_free(a);
+        }
+
+        return 0;
+}
+
 const BusProperty bus_unit_properties[] = {
         { "Id",                   bus_property_append_string,         "s", offsetof(Unit, id),                                         true },
         { "Names",                bus_unit_append_names,             "as", 0 },
@@ -874,9 +1104,6 @@ const BusProperty bus_unit_properties[] = {
         { "OnFailureIsolate",     bus_property_append_bool,           "b", offsetof(Unit, on_failure_isolate)                 },
         { "IgnoreOnIsolate",      bus_property_append_bool,           "b", offsetof(Unit, ignore_on_isolate)                  },
         { "IgnoreOnSnapshot",     bus_property_append_bool,           "b", offsetof(Unit, ignore_on_snapshot)                 },
-        { "DefaultControlGroup",  bus_unit_append_default_cgroup,     "s", 0 },
-        { "ControlGroup",         bus_unit_append_cgroups,           "as", 0 },
-        { "ControlGroupAttributes", bus_unit_append_cgroup_attrs,"a(sss)", 0 },
         { "NeedDaemonReload",     bus_unit_append_need_daemon_reload, "b", 0 },
         { "JobTimeoutUSec",       bus_property_append_usec,           "t", offsetof(Unit, job_timeout)                        },
         { "ConditionTimestamp",   bus_property_append_usec,           "t", offsetof(Unit, condition_timestamp.realtime)       },
@@ -885,3 +1112,10 @@ const BusProperty bus_unit_properties[] = {
         { "LoadError",            bus_unit_append_load_error,      "(ss)", 0 },
         { NULL, }
 };
+
+const BusProperty bus_unit_cgroup_properties[] = {
+        { "DefaultControlGroup",    bus_unit_append_default_cgroup,     "s", 0 },
+        { "ControlGroups",          bus_unit_append_cgroups,           "as", 0 },
+        { "ControlGroupAttributes", bus_unit_append_cgroup_attrs,  "a(sss)", 0 },
+        { NULL, }
+};