bus: synthesize local error reply when we cannot deliver a message to kdbus because...

[elogind.git] / src / libsystemd-bus / bus-kernel.c

diff --git a/src/libsystemd-bus/bus-kernel.c b/src/libsystemd-bus/bus-kernel.c
index 54e85c94439f2fbec5415e797aa4f8db574b9b0d..69143434b3cf9729f085a25f699552a328d678d0 100644 (file)
--- a/src/libsystemd-bus/bus-kernel.c
+++ b/src/libsystemd-bus/bus-kernel.c
@@ -356,6 +356,8 @@ int bus_kernel_take_fd(sd_bus *b) {
         if (asprintf(&b->unique_name, ":1.%llu", (unsigned long long) hello.id) < 0)
                 return -ENOMEM;
 
+        b->unique_id = hello.id;
+
         b->is_kernel = true;
         b->bus_client = true;
         b->can_fds = !!(hello.conn_flags & KDBUS_HELLO_ACCEPT_FD);
@@ -363,11 +365,7 @@ int bus_kernel_take_fd(sd_bus *b) {
         /* the kernel told us the UUID of the underlying bus */
         memcpy(b->server_id.bytes, hello.id128, sizeof(b->server_id.bytes));
 
-        r = bus_start_running(b);
-        if (r < 0)
-                return r;
-
-        return 1;
+        return bus_start_running(b);
 }
 
 int bus_kernel_connect(sd_bus *b) {
@@ -395,13 +393,60 @@ int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m) {
         assert(m);
         assert(bus->state == BUS_RUNNING);
 
+        /* If we can't deliver, we want room for the error message */
+        r = bus_rqueue_make_room(bus);
+        if (r < 0)
+                return r;
+
         r = bus_message_setup_kmsg(bus, m);
         if (r < 0)
                 return r;
 
         r = ioctl(bus->output_fd, KDBUS_CMD_MSG_SEND, m->kdbus);
-        if (r < 0)
-                return errno == EAGAIN ? 0 : -errno;
+        if (r < 0) {
+                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+                sd_bus_message *reply;
+
+                if (errno == EAGAIN || errno == EINTR)
+                        return 0;
+                else if (errno == ENXIO || errno == ESRCH) {
+
+                        /* ENXIO: unique name not known
+                         * ESRCH: well-known name not known */
+
+                        if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
+                                sd_bus_error_setf(&error, SD_BUS_ERROR_SERVICE_UNKNOWN, "Destination %s not known", m->destination);
+                        else
+                                return 0;
+
+                } else if (errno == EADDRNOTAVAIL) {
+
+                        /* EADDRNOTAVAIL: activation is possible, but turned off in request flags */
+
+                        if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
+                                sd_bus_error_setf(&error, SD_BUS_ERROR_SERVICE_UNKNOWN, "Activation of %s not requested", m->destination);
+                        else
+                                return 0;
+                } else
+                        return -errno;
+
+                r = bus_message_new_synthetic_error(
+                                bus,
+                                BUS_MESSAGE_SERIAL(m),
+                                &error,
+                                &reply);
+
+                if (r < 0)
+                        return r;
+
+                r = bus_seal_synthetic_message(bus, reply);
+                if (r < 0)
+                        return r;
+
+                bus->rqueue[bus->rqueue_size++] = reply;
+
+                return 0;
+        }
 
         return 1;
 }
@@ -446,15 +491,13 @@ static int push_name_owner_changed(sd_bus *bus, const char *name, const char *ol
 
         m->sender = "org.freedesktop.DBus";
 
-        r = bus_seal_message(bus, m);
-        if (r < 0)
-                return r;
-
-        r = bus_rqueue_push(bus, m);
+        r = bus_seal_synthetic_message(bus, m);
         if (r < 0)
                 return r;
 
+        bus->rqueue[bus->rqueue_size++] = m;
         m = NULL;
+
         return 1;
 }
 
@@ -516,15 +559,13 @@ static int translate_reply(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *
 
         m->sender = "org.freedesktop.DBus";
 
-        r = bus_seal_message(bus, m);
-        if (r < 0)
-                return r;
-
-        r = bus_rqueue_push(bus, m);
+        r = bus_seal_synthetic_message(bus, m);
         if (r < 0)
                 return r;
 
+        bus->rqueue[bus->rqueue_size++] = m;
         m = NULL;
+
         return 1;
 }
 
@@ -561,7 +602,7 @@ static int bus_kernel_translate_message(sd_bus *bus, struct kdbus_msg *k) {
                 return 0;
         }
 
-        return translate[found->type](bus, k, d);
+        return translate[found->type - _KDBUS_ITEM_KERNEL_BASE](bus, k, found);
 }
 
 int kdbus_translate_attach_flags(uint64_t mask, uint64_t *kdbus_mask) {
@@ -827,12 +868,9 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) {
         m->kdbus = k;
         m->release_kdbus = true;
         m->free_fds = true;
-
         fds = NULL;
 
-        r = bus_rqueue_push(bus, m);
-        if (r < 0)
-                goto fail;
+        bus->rqueue[bus->rqueue_size++] = m;
 
         return 1;
 
@@ -859,12 +897,7 @@ int bus_kernel_read_message(sd_bus *bus) {
 
         assert(bus);
 
-        /* Kernel messages might result in 2 new queued messages in
-         * the worst case (NameOwnerChange and LostName for the same
-         * well-known name, for example). Let's make room in
-         * advance. */
-
-        r = bus_rqueue_make_room(bus, 2);
+        r = bus_rqueue_make_room(bus);
         if (r < 0)
                 return r;