Merge pull request #14424 from poettering/watch-bus-name-rework

[thirdparty/systemd.git] / src / core / unit.c

diff --git a/src/core/unit.c b/src/core/unit.c
index b6b03ac4f4c2f365fd6dcac4ec21587d5915a7c4..0c03b363dbcdb08e08f542c49a4edebbffce1dad 100644 (file)
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -3201,24 +3201,21 @@ int unit_load_related_unit(Unit *u, const char *type, Unit **_found) {
 }
 
 static int signal_name_owner_changed(sd_bus_message *message, void *userdata, sd_bus_error *error) {
-        const char *name, *old_owner, *new_owner;
+        const char *new_owner;
         Unit *u = userdata;
         int r;
 
         assert(message);
         assert(u);
 
-        r = sd_bus_message_read(message, "sss", &name, &old_owner, &new_owner);
+        r = sd_bus_message_read(message, "sss", NULL, NULL, &new_owner);
         if (r < 0) {
                 bus_log_parse_error(r);
                 return 0;
         }
 
-        old_owner = empty_to_null(old_owner);
-        new_owner = empty_to_null(new_owner);
-
         if (UNIT_VTABLE(u)->bus_name_owner_change)
-                UNIT_VTABLE(u)->bus_name_owner_change(u, old_owner, new_owner);
+                UNIT_VTABLE(u)->bus_name_owner_change(u, empty_to_null(new_owner));
 
         return 0;
 }
@@ -3234,42 +3231,35 @@ static int get_name_owner_handler(sd_bus_message *message, void *userdata, sd_bu
 
         u->get_name_owner_slot = sd_bus_slot_unref(u->get_name_owner_slot);
 
-        if (sd_bus_error_is_set(error)) {
-                log_error("Failed to get name owner from bus: %s", error->message);
-                return 0;
-        }
-
         e = sd_bus_message_get_error(message);
-        if (sd_bus_error_has_name(e, "org.freedesktop.DBus.Error.NameHasNoOwner"))
-                return 0;
-
         if (e) {
-                log_error("Unexpected error response from GetNameOwner: %s", e->message);
-                return 0;
-        }
+                if (!sd_bus_error_has_name(e, "org.freedesktop.DBus.Error.NameHasNoOwner"))
+                        log_unit_error(u, "Unexpected error response from GetNameOwner(): %s", e->message);
 
-        r = sd_bus_message_read(message, "s", &new_owner);
-        if (r < 0) {
-                bus_log_parse_error(r);
-                return 0;
-        }
+                new_owner = NULL;
+        } else {
+                r = sd_bus_message_read(message, "s", &new_owner);
+                if (r < 0)
+                        return bus_log_parse_error(r);
 
-        new_owner = empty_to_null(new_owner);
+                assert(!isempty(new_owner));
+        }
 
         if (UNIT_VTABLE(u)->bus_name_owner_change)
-                UNIT_VTABLE(u)->bus_name_owner_change(u, NULL, new_owner);
+                UNIT_VTABLE(u)->bus_name_owner_change(u, new_owner);
 
         return 0;
 }
 
 int unit_install_bus_match(Unit *u, sd_bus *bus, const char *name) {
         const char *match;
+        int r;
 
         assert(u);
         assert(bus);
         assert(name);
 
-        if (u->match_bus_slot)
+        if (u->match_bus_slot || u->get_name_owner_slot)
                 return -EBUSY;
 
         match = strjoina("type='signal',"
@@ -3279,19 +3269,27 @@ int unit_install_bus_match(Unit *u, sd_bus *bus, const char *name) {
                          "member='NameOwnerChanged',"
                          "arg0='", name, "'");
 
-        int r = sd_bus_add_match_async(bus, &u->match_bus_slot, match, signal_name_owner_changed, NULL, u);
+        r = sd_bus_add_match_async(bus, &u->match_bus_slot, match, signal_name_owner_changed, NULL, u);
         if (r < 0)
                 return r;
 
-        return sd_bus_call_method_async(bus,
-                                        &u->get_name_owner_slot,
-                                        "org.freedesktop.DBus",
-                                        "/org/freedesktop/DBus",
-                                        "org.freedesktop.DBus",
-                                        "GetNameOwner",
-                                        get_name_owner_handler,
-                                        u,
-                                        "s", name);
+        r = sd_bus_call_method_async(
+                        bus,
+                        &u->get_name_owner_slot,
+                        "org.freedesktop.DBus",
+                        "/org/freedesktop/DBus",
+                        "org.freedesktop.DBus",
+                        "GetNameOwner",
+                        get_name_owner_handler,
+                        u,
+                        "s", name);
+        if (r < 0) {
+                u->match_bus_slot = sd_bus_slot_unref(u->match_bus_slot);
+                return r;
+        }
+
+        log_unit_debug(u, "Watching D-Bus name '%s'.", name);
+        return 0;
 }
 
 int unit_watch_bus_name(Unit *u, const char *name) {
@@ -3314,6 +3312,7 @@ int unit_watch_bus_name(Unit *u, const char *name) {
         r = hashmap_put(u->manager->watch_bus, name, u);
         if (r < 0) {
                 u->match_bus_slot = sd_bus_slot_unref(u->match_bus_slot);
+                u->get_name_owner_slot = sd_bus_slot_unref(u->get_name_owner_slot);
                 return log_warning_errno(r, "Failed to put bus name to hashmap: %m");
         }