core: add unit_dbus_interface_from_type() to unit-name.h

Let's add a way to get the type-specific D-Bus interface of a unit from
either its type or name to src/basic/unit-name.[ch]. That way we can
share it with the client side, where it is useful in tools like cgls or
machinectl.

Also ports over machinectl to make use of this.

19 files changed, 61 insertions, 35 deletions

diff --git a/src/basic/unit-name.c b/src/basic/unit-name.c
index fa530da456..8742ee757f 100644
--- a/src/basic/unit-name.c
+++ b/src/basic/unit-name.c
@@ -586,6 +586,42 @@ int unit_name_from_dbus_path(const char *path, char **name) {
         return 0;
 }
 
+const char* unit_dbus_interface_from_type(UnitType t) {
+
+        static const char *const table[_UNIT_TYPE_MAX] = {
+                [UNIT_SERVICE] = "org.freedesktop.systemd1.Service",
+                [UNIT_SOCKET] = "org.freedesktop.systemd1.Socket",
+                [UNIT_BUSNAME] = "org.freedesktop.systemd1.BusName",
+                [UNIT_TARGET] = "org.freedesktop.systemd1.Target",
+                [UNIT_SNAPSHOT] = "org.freedesktop.systemd1.Snapshot",
+                [UNIT_DEVICE] = "org.freedesktop.systemd1.Device",
+                [UNIT_MOUNT] = "org.freedesktop.systemd1.Mount",
+                [UNIT_AUTOMOUNT] = "org.freedesktop.systemd1.Automount",
+                [UNIT_SWAP] = "org.freedesktop.systemd1.Swap",
+                [UNIT_TIMER] = "org.freedesktop.systemd1.Timer",
+                [UNIT_PATH] = "org.freedesktop.systemd1.Path",
+                [UNIT_SLICE] = "org.freedesktop.systemd1.Slice",
+                [UNIT_SCOPE] = "org.freedesktop.systemd1.Scope",
+        };
+
+        if (t < 0)
+                return NULL;
+        if (t >= _UNIT_TYPE_MAX)
+                return NULL;
+
+        return table[t];
+}
+
+const char *unit_dbus_interface_from_name(const char *name) {
+        UnitType t;
+
+        t = unit_name_to_type(name);
+        if (t < 0)
+                return NULL;
+
+        return unit_dbus_interface_from_type(t);
+}
+
 static char *do_escape_mangle(const char *f, UnitNameMangle allow_globs, char *t) {
         const char *valid_chars;
 
@@ -787,7 +823,7 @@ static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
         [UNIT_TIMER] = "timer",
         [UNIT_PATH] = "path",
         [UNIT_SLICE] = "slice",
-        [UNIT_SCOPE] = "scope"
+        [UNIT_SCOPE] = "scope",
 };
 
 DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
diff --git a/src/basic/unit-name.h b/src/basic/unit-name.h
index b2043d0870..28b3a555f3 100644
--- a/src/basic/unit-name.h
+++ b/src/basic/unit-name.h
@@ -152,6 +152,9 @@ int unit_name_to_path(const char *name, char **ret);
 char *unit_dbus_path_from_name(const char *name);
 int unit_name_from_dbus_path(const char *path, char **name);
 
+const char* unit_dbus_interface_from_type(UnitType t);
+const char *unit_dbus_interface_from_name(const char *name);
+
 typedef enum UnitNameMangle {
         UNIT_NAME_NOGLOB,
         UNIT_NAME_GLOB,
diff --git a/src/core/automount.c b/src/core/automount.c
index 4af381b4b6..b8171ddad7 100644
--- a/src/core/automount.c
+++ b/src/core/automount.c
@@ -1075,7 +1075,6 @@ const UnitVTable automount_vtable = {
 
         .reset_failed = automount_reset_failed,
 
-        .bus_interface = "org.freedesktop.systemd1.Automount",
         .bus_vtable = bus_automount_vtable,
 
         .shutdown = automount_shutdown,
diff --git a/src/core/busname.c b/src/core/busname.c
index 9530a87311..d3c1282239 100644
--- a/src/core/busname.c
+++ b/src/core/busname.c
@@ -1058,7 +1058,6 @@ const UnitVTable busname_vtable = {
 
         .supported = busname_supported,
 
-        .bus_interface = "org.freedesktop.systemd1.BusName",
         .bus_vtable = bus_busname_vtable,
 
         .status_message_formats = {
diff --git a/src/core/dbus-unit.c b/src/core/dbus-unit.c
index 0a9effda71..42bb653cc1 100644
--- a/src/core/dbus-unit.c
+++ b/src/core/dbus-unit.c
@@ -783,7 +783,7 @@ static int send_changed_signal(sd_bus *bus, void *userdata) {
 
         r = sd_bus_emit_properties_changed_strv(
                         bus, p,
-                        UNIT_VTABLE(u)->bus_interface,
+                        unit_dbus_interface_from_type(u->type),
                         NULL);
         if (r < 0)
                 return r;
diff --git a/src/core/dbus.c b/src/core/dbus.c
index 44bf5cab28..d091aa5419 100644
--- a/src/core/dbus.c
+++ b/src/core/dbus.c
@@ -356,7 +356,7 @@ static int bus_unit_interface_find(sd_bus *bus, const char *path, const char *in
         if (r <= 0)
                 return r;
 
-        if (!streq_ptr(interface, UNIT_VTABLE(u)->bus_interface))
+        if (!streq_ptr(interface, unit_dbus_interface_from_type(u->type)))
                 return 0;
 
         *found = u;
@@ -378,7 +378,7 @@ static int bus_unit_cgroup_find(sd_bus *bus, const char *path, const char *inter
         if (r <= 0)
                 return r;
 
-        if (!streq_ptr(interface, UNIT_VTABLE(u)->bus_interface))
+        if (!streq_ptr(interface, unit_dbus_interface_from_type(u->type)))
                 return 0;
 
         if (!unit_get_cgroup_context(u))
@@ -404,7 +404,7 @@ static int bus_cgroup_context_find(sd_bus *bus, const char *path, const char *in
         if (r <= 0)
                 return r;
 
-        if (!streq_ptr(interface, UNIT_VTABLE(u)->bus_interface))
+        if (!streq_ptr(interface, unit_dbus_interface_from_type(u->type)))
                 return 0;
 
         c = unit_get_cgroup_context(u);
@@ -431,7 +431,7 @@ static int bus_exec_context_find(sd_bus *bus, const char *path, const char *inte
         if (r <= 0)
                 return r;
 
-        if (!streq_ptr(interface, UNIT_VTABLE(u)->bus_interface))
+        if (!streq_ptr(interface, unit_dbus_interface_from_type(u->type)))
                 return 0;
 
         c = unit_get_exec_context(u);
@@ -458,7 +458,7 @@ static int bus_kill_context_find(sd_bus *bus, const char *path, const char *inte
         if (r <= 0)
                 return r;
 
-        if (!streq_ptr(interface, UNIT_VTABLE(u)->bus_interface))
+        if (!streq_ptr(interface, unit_dbus_interface_from_type(u->type)))
                 return 0;
 
         c = unit_get_kill_context(u);
@@ -555,30 +555,34 @@ static int bus_setup_api_vtables(Manager *m, sd_bus *bus) {
                 return log_error_errno(r, "Failed to add job enumerator: %m");
 
         for (t = 0; t < _UNIT_TYPE_MAX; t++) {
-                r = sd_bus_add_fallback_vtable(bus, NULL, "/org/freedesktop/systemd1/unit", unit_vtable[t]->bus_interface, unit_vtable[t]->bus_vtable, bus_unit_interface_find, m);
+                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", unit_vtable[t]->bus_interface);
+                        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", unit_vtable[t]->bus_interface, bus_unit_cgroup_vtable, bus_unit_cgroup_find, m);
+                        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", unit_vtable[t]->bus_interface);
+                                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", unit_vtable[t]->bus_interface, bus_cgroup_vtable, bus_cgroup_context_find, m);
+                        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", unit_vtable[t]->bus_interface);
+                                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", unit_vtable[t]->bus_interface, bus_exec_vtable, bus_exec_context_find, m);
+                        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", unit_vtable[t]->bus_interface);
+                                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", unit_vtable[t]->bus_interface, bus_kill_vtable, bus_kill_context_find, m);
+                        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", unit_vtable[t]->bus_interface);
+                                return log_error_errno(r, "Failed to register kill vtable for %s: %m", interface);
                 }
         }
 
diff --git a/src/core/device.c b/src/core/device.c
index e7efcf0f0a..3f574b1832 100644
--- a/src/core/device.c
+++ b/src/core/device.c
@@ -849,7 +849,6 @@ const UnitVTable device_vtable = {
         .active_state = device_active_state,
         .sub_state_to_string = device_sub_state_to_string,
 
-        .bus_interface = "org.freedesktop.systemd1.Device",
         .bus_vtable = bus_device_vtable,
 
         .following = device_following,
diff --git a/src/core/mount.c b/src/core/mount.c
index c0d1cdfbd4..7e19e66a51 100644
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -1871,7 +1871,6 @@ const UnitVTable mount_vtable = {
 
         .reset_failed = mount_reset_failed,
 
-        .bus_interface = "org.freedesktop.systemd1.Mount",
         .bus_vtable = bus_mount_vtable,
         .bus_set_property = bus_mount_set_property,
         .bus_commit_properties = bus_mount_commit_properties,
diff --git a/src/core/path.c b/src/core/path.c
index 20995d920c..e9111d0612 100644
--- a/src/core/path.c
+++ b/src/core/path.c
@@ -770,6 +770,5 @@ const UnitVTable path_vtable = {
 
         .reset_failed = path_reset_failed,
 
-        .bus_interface = "org.freedesktop.systemd1.Path",
         .bus_vtable = bus_path_vtable
 };
diff --git a/src/core/scope.c b/src/core/scope.c
index ab1769b46b..bf89936153 100644
--- a/src/core/scope.c
+++ b/src/core/scope.c
@@ -561,7 +561,6 @@ const UnitVTable scope_vtable = {
 
         .notify_cgroup_empty = scope_notify_cgroup_empty_event,
 
-        .bus_interface = "org.freedesktop.systemd1.Scope",
         .bus_vtable = bus_scope_vtable,
         .bus_set_property = bus_scope_set_property,
         .bus_commit_properties = bus_scope_commit_properties,
diff --git a/src/core/service.c b/src/core/service.c
index b790ec98be..097e7c710c 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -3214,7 +3214,6 @@ const UnitVTable service_vtable = {
 
         .bus_name_owner_change = service_bus_name_owner_change,
 
-        .bus_interface = "org.freedesktop.systemd1.Service",
         .bus_vtable = bus_service_vtable,
         .bus_set_property = bus_service_set_property,
         .bus_commit_properties = bus_service_commit_properties,
diff --git a/src/core/slice.c b/src/core/slice.c
index 064eb5d933..7442d23391 100644
--- a/src/core/slice.c
+++ b/src/core/slice.c
@@ -289,7 +289,6 @@ const UnitVTable slice_vtable = {
         .active_state = slice_active_state,
         .sub_state_to_string = slice_sub_state_to_string,
 
-        .bus_interface = "org.freedesktop.systemd1.Slice",
         .bus_vtable = bus_slice_vtable,
         .bus_set_property = bus_slice_set_property,
         .bus_commit_properties = bus_slice_commit_properties,
diff --git a/src/core/snapshot.c b/src/core/snapshot.c
index 9518e21f36..336ff20f84 100644
--- a/src/core/snapshot.c
+++ b/src/core/snapshot.c
@@ -302,6 +302,5 @@ const UnitVTable snapshot_vtable = {
         .active_state = snapshot_active_state,
         .sub_state_to_string = snapshot_sub_state_to_string,
 
-        .bus_interface = "org.freedesktop.systemd1.Snapshot",
         .bus_vtable = bus_snapshot_vtable
 };
diff --git a/src/core/socket.c b/src/core/socket.c
index a387057473..08efc3754c 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -2709,7 +2709,6 @@ const UnitVTable socket_vtable = {
 
         .reset_failed = socket_reset_failed,
 
-        .bus_interface = "org.freedesktop.systemd1.Socket",
         .bus_vtable = bus_socket_vtable,
         .bus_set_property = bus_socket_set_property,
         .bus_commit_properties = bus_socket_commit_properties,
diff --git a/src/core/swap.c b/src/core/swap.c
index 0bc3827ff0..349fd6f7b9 100644
--- a/src/core/swap.c
+++ b/src/core/swap.c
@@ -1485,7 +1485,6 @@ const UnitVTable swap_vtable = {
 
         .reset_failed = swap_reset_failed,
 
-        .bus_interface = "org.freedesktop.systemd1.Swap",
         .bus_vtable = bus_swap_vtable,
         .bus_set_property = bus_swap_set_property,
         .bus_commit_properties = bus_swap_commit_properties,
diff --git a/src/core/target.c b/src/core/target.c
index b492a7c4c7..f714cb31c2 100644
--- a/src/core/target.c
+++ b/src/core/target.c
@@ -221,7 +221,6 @@ const UnitVTable target_vtable = {
         .active_state = target_active_state,
         .sub_state_to_string = target_sub_state_to_string,
 
-        .bus_interface = "org.freedesktop.systemd1.Target",
         .bus_vtable = bus_target_vtable,
 
         .status_message_formats = {
diff --git a/src/core/timer.c b/src/core/timer.c
index 89758c6b19..eb6567bbfa 100644
--- a/src/core/timer.c
+++ b/src/core/timer.c
@@ -772,7 +772,6 @@ const UnitVTable timer_vtable = {
         .reset_failed = timer_reset_failed,
         .time_change = timer_time_change,
 
-        .bus_interface = "org.freedesktop.systemd1.Timer",
         .bus_vtable = bus_timer_vtable,
         .bus_set_property = bus_timer_set_property,
 
diff --git a/src/core/unit.h b/src/core/unit.h
index 9df5a7e6fb..f53b7f6da1 100644
--- a/src/core/unit.h
+++ b/src/core/unit.h
@@ -404,9 +404,6 @@ struct UnitVTable {
          * of this type will immediately fail. */
         bool (*supported)(void);
 
-        /* The interface name */
-        const char *bus_interface;
-
         /* The bus vtable */
         const sd_bus_vtable *bus_vtable;
 
diff --git a/src/machine/machinectl.c b/src/machine/machinectl.c
index 926035d185..8bd0ed756b 100644
--- a/src/machine/machinectl.c
+++ b/src/machine/machinectl.c
@@ -361,8 +361,7 @@ static int show_unit_cgroup(sd_bus *bus, const char *unit, pid_t leader) {
                         bus,
                         "org.freedesktop.systemd1",
                         path,
-                        endswith(unit, ".scope") ? "org.freedesktop.systemd1.Scope" :
-                        endswith(unit, ".slice") ? "org.freedesktop.systemd1.Slice" : "org.freedesktop.systemd1.Service",
+                        unit_dbus_interface_from_name(unit),
                         "ControlGroup",
                         &error,
                         &reply,