sd-bus: add sd_bus_message.verify_destination_id and .destination_ptr

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

diff --git a/src/libsystemd/sd-bus/bus-kernel.c b/src/libsystemd/sd-bus/bus-kernel.c
index 153abee56f3bbfebd1235e3a334181d033a1a674..5e7bc122392ac8f7b1823a609b1f6e8443524095 100644 (file)
--- a/src/libsystemd/sd-bus/bus-kernel.c
+++ b/src/libsystemd/sd-bus/bus-kernel.c
@@ -204,6 +204,7 @@ static int bus_message_setup_bloom(sd_bus_message *m, struct kdbus_bloom_filter
 static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         struct bus_body_part *part;
         struct kdbus_item *d;
 static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         struct bus_body_part *part;
         struct kdbus_item *d;

+        const char *destination;

         bool well_known;
         uint64_t unique;
         size_t sz, dl;
         bool well_known;
         uint64_t unique;
         size_t sz, dl;


@@ -219,8 +220,10 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         if (m->kdbus)
                 return 0;
 
         if (m->kdbus)
                 return 0;
 

-        if (m->destination) {
-                r = bus_kernel_parse_unique_name(m->destination, &unique);
+        destination = m->destination ?: m->destination_ptr;
+
+        if (destination) {
+                r = bus_kernel_parse_unique_name(destination, &unique);

                 if (r < 0)
                         return r;
 
                 if (r < 0)
                         return r;
 


@@ -244,7 +247,7 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
 
         /* Add in well-known destination header */
         if (well_known) {
 
         /* Add in well-known destination header */
         if (well_known) {

-                dl = strlen(m->destination);
+                dl = strlen(destination);

                 sz += ALIGN8(offsetof(struct kdbus_item, str) + dl + 1);
         }
 
                 sz += ALIGN8(offsetof(struct kdbus_item, str) + dl + 1);
         }
 


@@ -264,9 +267,17 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         m->kdbus->flags =
                 ((m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) ? 0 : KDBUS_MSG_FLAGS_EXPECT_REPLY) |
                 ((m->header->flags & BUS_MESSAGE_NO_AUTO_START) ? KDBUS_MSG_FLAGS_NO_AUTO_START : 0);
         m->kdbus->flags =
                 ((m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) ? 0 : KDBUS_MSG_FLAGS_EXPECT_REPLY) |
                 ((m->header->flags & BUS_MESSAGE_NO_AUTO_START) ? KDBUS_MSG_FLAGS_NO_AUTO_START : 0);

-        m->kdbus->dst_id =
-                well_known ? 0 :
-                m->destination ? unique : KDBUS_DST_ID_BROADCAST;
+
+        if (well_known) {
+                /* verify_destination_id will usually be 0, which makes the kernel driver only look
+                 * at the provided well-known name. Otherwise, the kernel will make sure the provided
+                 * destination id matches the owner of the provided weel-known-name, and fail if they
+                 * differ. Currently, this is only needed for bus-proxyd. */
+                m->kdbus->dst_id = m->verify_destination_id;
+        } else {
+                m->kdbus->dst_id = destination ? unique : KDBUS_DST_ID_BROADCAST;
+        }
+

         m->kdbus->payload_type = KDBUS_PAYLOAD_DBUS;
         m->kdbus->cookie = (uint64_t) m->header->serial;
         m->kdbus->priority = m->priority;
         m->kdbus->payload_type = KDBUS_PAYLOAD_DBUS;
         m->kdbus->cookie = (uint64_t) m->header->serial;
         m->kdbus->priority = m->priority;


@@ -284,7 +295,7 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         d = m->kdbus->items;
 
         if (well_known)
         d = m->kdbus->items;
 
         if (well_known)

-                append_destination(&d, m->destination, dl);
+                append_destination(&d, destination, dl);

 
         append_payload_vec(&d, m->header, BUS_MESSAGE_BODY_BEGIN(m));
 
 
         append_payload_vec(&d, m->header, BUS_MESSAGE_BODY_BEGIN(m));
 


@@ -299,7 +310,7 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
                         continue;
                 }
 
                         continue;
                 }
 

-                if (part->memfd >= 0 && part->sealed && m->destination) {
+                if (part->memfd >= 0 && part->sealed && destination) {

                         /* Try to send a memfd, if the part is
                          * sealed and this is not a broadcast. Since we can only  */
 
                         /* Try to send a memfd, if the part is
                          * sealed and this is not a broadcast. Since we can only  */