bus: make kdbus work so that we can exchange real messages

We have ignition, we have tremendous fire!

4 files changed, 24 insertions, 6 deletions

diff --git a/src/libsystemd-bus/bus-kernel.c b/src/libsystemd-bus/bus-kernel.c
index b83dfcbc27..712b697b0a 100644
--- a/src/libsystemd-bus/bus-kernel.c
+++ b/src/libsystemd-bus/bus-kernel.c
@@ -83,7 +83,9 @@ static int bus_message_setup_kmsg(sd_bus_message *m) {
 
         assert(m);
         assert(m->sealed);
-        assert(!m->kdbus);
+
+        if (m->kdbus)
+                return 0;
 
         if (m->destination) {
                 r = parse_unique_name(m->destination, &unique);
@@ -140,9 +142,11 @@ static int bus_message_setup_kmsg(sd_bus_message *m) {
         if (m->body)
                 append_payload_vec(&d, m->body, m->header->body_size);
 
-        m->kdbus->size = (uint8_t*) m - (uint8_t*) m->kdbus;
+        m->kdbus->size = (uint8_t*) d - (uint8_t*) m->kdbus;
         assert(m->kdbus->size <= sz);
 
+        m->free_kdbus = true;
+
         return 0;
 }
 
@@ -282,14 +286,14 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
                         continue;
 
                 l = d->size - offsetof(struct kdbus_msg_data, data);
-
                 if (idx == sizeof(struct bus_header) &&
                     l == BUS_MESSAGE_FIELDS_SIZE(m))
                         m->fields = d->data;
                 else if (idx == sizeof(struct bus_header) + ALIGN8(BUS_MESSAGE_FIELDS_SIZE(m)) &&
                          l == BUS_MESSAGE_BODY_SIZE(m))
                         m->body = d->data;
-                else {
+                else if (!(idx == 0 && l == sizeof(struct bus_header)) &&
+                         !(idx == sizeof(struct bus_header) + BUS_MESSAGE_FIELDS_SIZE(m))) {
                         sd_bus_message_unref(m);
                         return -EBADMSG;
                 }
@@ -339,7 +343,7 @@ int bus_kernel_read_message(sd_bus *bus, sd_bus_message **m) {
                 if (errno == EAGAIN)
                         return 0;
 
-                if (errno != EMSGSIZE)
+                if (errno != ENOBUFS)
                         return -errno;
 
                 sz *= 2;
diff --git a/src/libsystemd-bus/sd-bus.c b/src/libsystemd-bus/sd-bus.c
index 29487cbd31..2424ee1446 100644
--- a/src/libsystemd-bus/sd-bus.c
+++ b/src/libsystemd-bus/sd-bus.c
@@ -55,6 +55,7 @@ static void bus_free(sd_bus *b) {
         free(b->unique_name);
         free(b->auth_buffer);
         free(b->address);
+        free(b->kernel);
 
         free(b->exec_path);
         strv_free(b->exec_argv);
diff --git a/src/libsystemd-bus/test-bus-kernel.c b/src/libsystemd-bus/test-bus-kernel.c
index 2241e65adf..4c599788fe 100644
--- a/src/libsystemd-bus/test-bus-kernel.c
+++ b/src/libsystemd-bus/test-bus-kernel.c
@@ -29,7 +29,8 @@
 int main(int argc, char *argv[]) {
         _cleanup_close_ int bus_ref = -1;
         _cleanup_free_ char *bus_name = NULL, *address = NULL;
-        const char *ua = NULL, *ub = NULL;
+        _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
+        const char *ua = NULL, *ub = NULL, *the_string = NULL;
         sd_bus *a, *b;
         int r;
 
@@ -67,6 +68,17 @@ int main(int argc, char *argv[]) {
 
         printf("unique b: %s\n", ub);
 
+        r = sd_bus_emit_signal(a, "/foo", "waldo.com", "Piep", "s", "I am a string");
+        assert_se(r >= 0);
+
+        r = sd_bus_process(b, &m);
+        assert_se(r > 0);
+        assert_se(m);
+
+        r = sd_bus_message_read(m, "s", &the_string);
+        assert_se(r >= 0);
+        assert_se(streq(the_string, "I am a string"));
+
         sd_bus_unref(a);
         sd_bus_unref(b);
 
diff --git a/src/systemd/sd-bus.h b/src/systemd/sd-bus.h
index 5dcc5014cf..748d76b02b 100644
--- a/src/systemd/sd-bus.h
+++ b/src/systemd/sd-bus.h
@@ -33,6 +33,7 @@ extern "C" {
 #endif
 
 /* TODO:
+ * - instead of adding in padding iovec when sending simply extend header buffer
  * - add page donation logic
  * - api for appending/reading fixed arrays
  * - merge busctl into systemctl or so?