bus: remarshal messages when necessary before sending

3 files changed, 119 insertions, 11 deletions

diff --git a/src/libsystemd-bus/bus-message.c b/src/libsystemd-bus/bus-message.c
index 3f70f6f30e..1a461e62e0 100644
--- a/src/libsystemd-bus/bus-message.c
+++ b/src/libsystemd-bus/bus-message.c
@@ -35,6 +35,7 @@
 #include "bus-type.h"
 #include "bus-signature.h"
 #include "bus-gvariant.h"
+#include "bus-util.h"
 
 static int message_append_basic(sd_bus_message *m, char type, const void *p, const void **stored);
 
@@ -5407,3 +5408,87 @@ _public_ sd_bus *sd_bus_message_get_bus(sd_bus_message *m) {
 
         return m->bus;
 }
+
+int bus_message_remarshal(sd_bus *bus, sd_bus_message **m) {
+        _cleanup_bus_message_unref_ sd_bus_message *n = NULL;
+        usec_t timeout;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(*m);
+
+        switch ((*m)->header->type) {
+
+        case SD_BUS_MESSAGE_SIGNAL:
+                r = sd_bus_message_new_signal(bus, (*m)->path, (*m)->interface, (*m)->member, &n);
+                if (r < 0)
+                        return r;
+
+                break;
+
+        case SD_BUS_MESSAGE_METHOD_CALL:
+                r = sd_bus_message_new_method_call(bus, (*m)->destination, (*m)->path, (*m)->interface, (*m)->member, &n);
+                if (r < 0)
+                        return r;
+
+                break;
+
+        case SD_BUS_MESSAGE_METHOD_RETURN:
+        case SD_BUS_MESSAGE_METHOD_ERROR:
+
+                n = message_new(bus, (*m)->header->type);
+                if (!n)
+                        return -ENOMEM;
+
+                n->reply_serial = (*m)->reply_serial;
+                r = message_append_field_uint32(n, BUS_MESSAGE_HEADER_REPLY_SERIAL, n->reply_serial);
+                if (r < 0)
+                        return r;
+
+                if ((*m)->header->type == SD_BUS_MESSAGE_METHOD_ERROR && (*m)->error.name) {
+                        r = message_append_field_string(n, BUS_MESSAGE_HEADER_ERROR_NAME, SD_BUS_TYPE_STRING, (*m)->error.name, &n->error.message);
+                        if (r < 0)
+                                return r;
+
+                        n->error._need_free = -1;
+                }
+
+                break;
+
+        default:
+                return -EINVAL;
+        }
+
+        if ((*m)->destination && !n->destination) {
+                r = message_append_field_string(n, BUS_MESSAGE_HEADER_DESTINATION, SD_BUS_TYPE_STRING, (*m)->destination, &n->destination);
+                if (r < 0)
+                        return r;
+        }
+
+        if ((*m)->sender && !n->sender) {
+                r = message_append_field_string(n, BUS_MESSAGE_HEADER_SENDER, SD_BUS_TYPE_STRING, (*m)->sender, &n->sender);
+                if (r < 0)
+                        return r;
+        }
+
+        n->header->flags |= (*m)->header->flags & (BUS_MESSAGE_NO_REPLY_EXPECTED|BUS_MESSAGE_NO_AUTO_START);
+
+        r = sd_bus_message_copy(n, *m, true);
+        if (r < 0)
+                return r;
+
+        timeout = (*m)->timeout;
+        if (timeout == 0 && !((*m)->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED))
+                timeout = BUS_DEFAULT_TIMEOUT;
+
+        r = bus_message_seal(n, (*m)->header->serial, timeout);
+        if (r < 0)
+                return r;
+
+        sd_bus_message_unref(*m);
+        *m = n;
+        n = NULL;
+
+        return 0;
+}
diff --git a/src/libsystemd-bus/bus-message.h b/src/libsystemd-bus/bus-message.h
index 9ef92cf289..a9d42c345a 100644
--- a/src/libsystemd-bus/bus-message.h
+++ b/src/libsystemd-bus/bus-message.h
@@ -231,3 +231,5 @@ void bus_body_part_unmap(struct bus_body_part *part);
 int bus_message_to_errno(sd_bus_message *m);
 
 int bus_message_new_synthetic_error(sd_bus *bus, uint64_t serial, const sd_bus_error *e, sd_bus_message **m);
+
+int bus_message_remarshal(sd_bus *bus, sd_bus_message **m);
diff --git a/src/libsystemd-bus/sd-bus.c b/src/libsystemd-bus/sd-bus.c
index 76a27ec3c7..338ce0619d 100644
--- a/src/libsystemd-bus/sd-bus.c
+++ b/src/libsystemd-bus/sd-bus.c
@@ -1319,14 +1319,6 @@ static int bus_seal_message(sd_bus *b, sd_bus_message *m, usec_t timeout) {
         assert(b);
         assert(m);
 
-        if (b->message_version != 0 &&
-            m->header->version != b->message_version)
-                return -EPERM;
-
-        if (b->message_endian != 0 &&
-            m->header->endian != b->message_endian)
-                return -EPERM;
-
         if (m->sealed) {
                 /* If we copy the same message to multiple
                  * destinations, avoid using the same serial
@@ -1341,6 +1333,18 @@ static int bus_seal_message(sd_bus *b, sd_bus_message *m, usec_t timeout) {
         return bus_message_seal(m, ++b->serial, timeout);
 }
 
+static int bus_remarshal_message(sd_bus *b, sd_bus_message **m) {
+        assert(b);
+
+        /* Do packet version and endianess already match? */
+        if ((b->message_version == 0 || b->message_version == (*m)->header->version) &&
+            (b->message_endian == 0 || b->message_endian == (*m)->header->endian))
+                return 0;
+
+        /* No? Then remarshal! */
+        return bus_message_remarshal(b, m);
+}
+
 int bus_seal_synthetic_message(sd_bus *b, sd_bus_message *m) {
         assert(b);
         assert(m);
@@ -1452,7 +1456,8 @@ static int dispatch_rqueue(sd_bus *bus, sd_bus_message **m) {
         }
 }
 
-_public_ int sd_bus_send(sd_bus *bus, sd_bus_message *m, uint64_t *serial) {
+_public_ int sd_bus_send(sd_bus *bus, sd_bus_message *_m, uint64_t *serial) {
+        _cleanup_bus_message_unref_ sd_bus_message *m = sd_bus_message_ref(_m);
         int r;
 
         assert_return(bus, -EINVAL);
@@ -1477,6 +1482,12 @@ _public_ int sd_bus_send(sd_bus *bus, sd_bus_message *m, uint64_t *serial) {
         if (r < 0)
                 return r;
 
+        /* Remarshall if we have to. This will possible unref the
+         * message and place a replacement in m */
+        r = bus_remarshal_message(bus, &m);
+        if (r < 0)
+                return r;
+
         /* If this is a reply and no reply was requested, then let's
          * suppress this, if we can */
         if (m->dont_send && !serial)
@@ -1567,12 +1578,13 @@ static int timeout_compare(const void *a, const void *b) {
 
 _public_ int sd_bus_call_async(
                 sd_bus *bus,
-                sd_bus_message *m,
+                sd_bus_message *_m,
                 sd_bus_message_handler_t callback,
                 void *userdata,
                 uint64_t usec,
                 uint64_t *serial) {
 
+        _cleanup_bus_message_unref_ sd_bus_message *m = sd_bus_message_ref(_m);
         struct reply_callback *c;
         int r;
 
@@ -1596,6 +1608,10 @@ _public_ int sd_bus_call_async(
         if (r < 0)
                 return r;
 
+        r = bus_remarshal_message(bus, &m);
+        if (r < 0)
+                return r;
+
         c = new0(struct reply_callback, 1);
         if (!c)
                 return -ENOMEM;
@@ -1674,11 +1690,12 @@ int bus_ensure_running(sd_bus *bus) {
 
 _public_ int sd_bus_call(
                 sd_bus *bus,
-                sd_bus_message *m,
+                sd_bus_message *_m,
                 uint64_t usec,
                 sd_bus_error *error,
                 sd_bus_message **reply) {
 
+        _cleanup_bus_message_unref_ sd_bus_message *m = sd_bus_message_ref(_m);
         usec_t timeout;
         uint64_t serial;
         unsigned i;
@@ -1702,6 +1719,10 @@ _public_ int sd_bus_call(
         if (r < 0)
                 return r;
 
+        r = bus_remarshal_message(bus, &m);
+        if (r < 0)
+                return r;
+
         r = sd_bus_send(bus, m, &serial);
         if (r < 0)
                 return r;