bus: implement basic name registration with kdbus

src/libsystemd-bus/bus-control.c

@@ -54,26 +54,46 @@ int sd_bus_request_name(sd_bus *bus, const char *name, int flags) {
                 return -EINVAL;
         if (!name)
                 return -EINVAL;
+        if (!bus->bus_client)
+                return -EINVAL;
 
-        r = sd_bus_call_method(
-                        bus,
-                        "org.freedesktop.DBus",
-                        "/",
-                        "org.freedesktop.DBus",
-                        "RequestName",
-                        NULL,
-                        &reply,
-                        "su",
-                        name,
-                        flags);
-        if (r < 0)
-                return r;
-
-        r = sd_bus_message_read(reply, "u", &ret);
-        if (r < 0)
-                return r;
-
-        return ret;
+        if (bus->is_kernel) {
+                struct kdbus_cmd_name *n;
+                size_t l;
+
+                l = strlen(name);
+                n = alloca(offsetof(struct kdbus_cmd_name, name) + l + 1);
+                n->size = offsetof(struct kdbus_cmd_name, name) + l + 1;
+                n->flags = flags;
+                n->id = 0;
+                memcpy(n->name, name, l+1);
+
+                r = ioctl(bus->input_fd, KDBUS_CMD_NAME_ACQUIRE, n);
+                if (r < 0)
+                        return -errno;
+
+                return n->flags;
+        } else {
+                r = sd_bus_call_method(
+                                bus,
+                                "org.freedesktop.DBus",
+                                "/",
+                                "org.freedesktop.DBus",
+                                "RequestName",
+                                NULL,
+                                &reply,
+                                "su",
+                                name,
+                                flags);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_read(reply, "u", &ret);
+                if (r < 0)
+                        return r;
+
+                return ret;
+        }
 }
 
 int sd_bus_release_name(sd_bus *bus, const char *name) {
@@ -85,23 +105,43 @@ int sd_bus_release_name(sd_bus *bus, const char *name) {
                 return -EINVAL;
         if (!name)
                 return -EINVAL;
+        if (!bus->bus_client)
+                return -EINVAL;
 
-        r = sd_bus_call_method(
-                        bus,
-                        "org.freedesktop.DBus",
-                        "/",
-                        "org.freedesktop.DBus",
-                        "ReleaseName",
-                        NULL,
-                        &reply,
-                        "s",
-                        name);
-        if (r < 0)
-                return r;
-
-        r = sd_bus_message_read(reply, "u", &ret);
-        if (r < 0)
-                return r;
+        if (bus->is_kernel) {
+                struct kdbus_cmd_name *n;
+                size_t l;
+
+                l = strlen(name);
+                n = alloca(offsetof(struct kdbus_cmd_name, name) + l + 1);
+                n->size = offsetof(struct kdbus_cmd_name, name) + l + 1;
+                n->flags = 0;
+                n->id = 0;
+                memcpy(n->name, name, l+1);
+
+                r = ioctl(bus->input_fd, KDBUS_CMD_NAME_RELEASE, n);
+                if (r < 0)
+                        return -errno;
+
+                return n->flags;
+        } else {
+                r = sd_bus_call_method(
+                                bus,
+                                "org.freedesktop.DBus",
+                                "/",
+                                "org.freedesktop.DBus",
+                                "ReleaseName",
+                                NULL,
+                                &reply,
+                                "s",
+                                name);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_read(reply, "u", &ret);
+                if (r < 0)
+                        return r;
+        }
 
         return ret;
 }

src/libsystemd-bus/bus-kernel.c

@@ -158,6 +158,9 @@ int bus_kernel_take_fd(sd_bus *b) {
 
         assert(b);
 
+        if (b->is_server)
+                return -EINVAL;
+
         r = ioctl(b->input_fd, KDBUS_CMD_HELLO, &hello);
         if (r < 0)
                 return -errno;
@@ -166,6 +169,7 @@ int bus_kernel_take_fd(sd_bus *b) {
                 return -ENOMEM;
 
         b->is_kernel = true;
+        b->bus_client = true;
 
         r = bus_start_running(b);
         if (r < 0)
@@ -180,6 +184,9 @@ int bus_kernel_connect(sd_bus *b) {
         assert(b->output_fd < 0);
         assert(b->kernel);
 
+        if (b->is_server)
+                return -EINVAL;
+
         b->input_fd = open(b->kernel, O_RDWR|O_NOCTTY|O_CLOEXEC);
         if (b->input_fd < 0)
                 return -errno;
@@ -339,7 +346,7 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
 
 int bus_kernel_read_message(sd_bus *bus, sd_bus_message **m) {
         struct kdbus_msg *k;
-        size_t sz = 128;
+        size_t sz = 1024;
         int r;
 
         assert(bus);

src/libsystemd-bus/sd-bus.c

@@ -280,7 +280,7 @@ static int bus_send_hello(sd_bus *bus) {
 int bus_start_running(sd_bus *bus) {
         assert(bus);
 
-        if (bus->bus_client) {
+        if (bus->bus_client && !bus->is_kernel) {
                 bus->state = BUS_HELLO;
                 return 1;
         }

src/libsystemd-bus/test-bus-kernel.c

@@ -85,6 +85,15 @@ int main(int argc, char *argv[]) {
         assert_se(r >= 0);
         assert_se(streq(the_string, "I am a string"));
 
+        r = sd_bus_request_name(a, "net.0pointer.foobar", 0);
+        assert_se(r >= 0);
+
+        r = sd_bus_release_name(a, "net.0pointer.foobar");
+        assert_se(r >= 0);
+
+        r = sd_bus_release_name(a, "net.0pointer.foobar");
+        assert_se(r < 0);
+
         sd_bus_unref(a);
         sd_bus_unref(b);