bus: add APIs to easily query string and strv properties

3 files changed, 81 insertions, 2 deletions

diff --git a/src/libsystemd-bus/bus-convenience.c b/src/libsystemd-bus/bus-convenience.c
index 0ccc259ea..4dc65b971 100644
--- a/src/libsystemd-bus/bus-convenience.c
+++ b/src/libsystemd-bus/bus-convenience.c
@@ -305,6 +305,81 @@ _public_ int sd_bus_get_property_trivial(
         return 0;
 }
 
+_public_ int sd_bus_get_property_string(
+                sd_bus *bus,
+                const char *destination,
+                const char *path,
+                const char *interface,
+                const char *member,
+                sd_bus_error *error,
+                char **ret) {
+
+        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        const char *s;
+        char *n;
+        int r;
+
+        assert_return(bus, -EINVAL);
+        assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL);
+        assert_return(member_name_is_valid(member), -EINVAL);
+        assert_return(ret, -EINVAL);
+        assert_return(BUS_IS_OPEN(bus->state), -ENOTCONN);
+        assert_return(!bus_pid_changed(bus), -ECHILD);
+
+        r = sd_bus_call_method(bus, destination, path, "org.freedesktop.DBus.Properties", "Get", error, &reply, "ss", strempty(interface), member);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_enter_container(reply, 'v', "s");
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_read_basic(reply, 's', &s);
+        if (r < 0)
+                return r;
+
+        n = strdup(s);
+        if (!n)
+                return -ENOMEM;
+
+        *ret = n;
+        return 0;
+}
+
+_public_ int sd_bus_get_property_strv(
+                sd_bus *bus,
+                const char *destination,
+                const char *path,
+                const char *interface,
+                const char *member,
+                sd_bus_error *error,
+                char ***ret) {
+
+        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        int r;
+
+        assert_return(bus, -EINVAL);
+        assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL);
+        assert_return(member_name_is_valid(member), -EINVAL);
+        assert_return(ret, -EINVAL);
+        assert_return(BUS_IS_OPEN(bus->state), -ENOTCONN);
+        assert_return(!bus_pid_changed(bus), -ECHILD);
+
+        r = sd_bus_call_method(bus, destination, path, "org.freedesktop.DBus.Properties", "Get", error, &reply, "ss", strempty(interface), member);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_enter_container(reply, 'v', NULL);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_read_strv(reply, ret);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
 _public_ int sd_bus_set_property(
                 sd_bus *bus,
                 const char *destination,
diff --git a/src/libsystemd-bus/libsystemd-bus.sym b/src/libsystemd-bus/libsystemd-bus.sym
index 5eecfa1cf..4924cf165 100644
--- a/src/libsystemd-bus/libsystemd-bus.sym
+++ b/src/libsystemd-bus/libsystemd-bus.sym
@@ -142,6 +142,8 @@ global:
         sd_bus_call_method;
         sd_bus_get_property;
         sd_bus_get_property_trivial;
+        sd_bus_get_property_string;
+        sd_bus_get_property_strv;
         sd_bus_set_property;
         sd_bus_reply_method_return;
         sd_bus_reply_method_error;
diff --git a/src/systemd/sd-bus.h b/src/systemd/sd-bus.h
index e6264074e..f843c778c 100644
--- a/src/systemd/sd-bus.h
+++ b/src/systemd/sd-bus.h
@@ -197,7 +197,7 @@ int sd_bus_message_copy(sd_bus_message *m, sd_bus_message *source, int all);
 int sd_bus_message_read(sd_bus_message *m, const char *types, ...);
 int sd_bus_message_read_basic(sd_bus_message *m, char type, void *p);
 int sd_bus_message_read_array(sd_bus_message *m, char type, const void **ptr, size_t *size);
-int sd_bus_message_read_strv(sd_bus_message *m, char ***l);
+int sd_bus_message_read_strv(sd_bus_message *m, char ***l); /* free the result! */
 int sd_bus_message_skip(sd_bus_message *m, const char *types);
 int sd_bus_message_enter_container(sd_bus_message *m, char type, const char *contents);
 int sd_bus_message_exit_container(sd_bus_message *m);
@@ -211,6 +211,8 @@ int sd_bus_message_rewind(sd_bus_message *m, int complete);
 int sd_bus_call_method(sd_bus *bus, const char *destination, const char *path, const char *interface, const char *member, sd_bus_error *error, sd_bus_message **reply, const char *types, ...);
 int sd_bus_get_property(sd_bus *bus, const char *destination, const char *path, const char *interface, const char *member, sd_bus_error *error, sd_bus_message **reply, const char *type);
 int sd_bus_get_property_trivial(sd_bus *bus, const char *destination, const char *path, const char *interface, const char *member, sd_bus_error *error, char type, void *ptr);
+int sd_bus_get_property_string(sd_bus *bus, const char *destination, const char *path, const char *interface, const char *member, sd_bus_error *error, char **ret); /* free the result! */
+int sd_bus_get_property_strv(sd_bus *bus, const char *destination, const char *path, const char *interface, const char *member, sd_bus_error *error, char ***ret); /* free the result! */
 int sd_bus_set_property(sd_bus *bus, const char *destination, const char *path, const char *interface, const char *member, sd_bus_error *error, const char *type, ...);
 int sd_bus_reply_method_return(sd_bus *bus, sd_bus_message *call, const char *types, ...);
 int sd_bus_reply_method_error(sd_bus *bus, sd_bus_message *call, const sd_bus_error *e);
@@ -234,7 +236,7 @@ int sd_bus_get_unique_name(sd_bus *bus, const char **unique);
 int sd_bus_request_name(sd_bus *bus, const char *name, int flags);
 int sd_bus_release_name(sd_bus *bus, const char *name);
 int sd_bus_list_names(sd_bus *bus, char ***l);
-int sd_bus_get_owner(sd_bus *bus, const char *name, char **owner);
+int sd_bus_get_owner(sd_bus *bus, const char *name, char **owner); /* free the result! */
 int sd_bus_get_owner_uid(sd_bus *bus, const char *name, uid_t *uid);
 int sd_bus_get_owner_pid(sd_bus *bus, const char *name, pid_t *pid);
 int sd_bus_get_owner_machine_id(sd_bus *bus, const char *name, sd_id128_t *machine);