bus: parse uid/gid/pid/tid meta data from kdbus messages

[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 b53c5eddcbb2ad49546589030f84446febbdeb8a..83379d1430408f6807f53a90edb28b5a38174a61 100644 (file)
--- 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;
 }
 
@@ -220,6 +224,7 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
         _cleanup_free_ int *fds = NULL;
         struct bus_header *h = NULL;
         size_t total, n_bytes = 0, idx = 0;
+        struct kdbus_creds *creds = NULL;
         int r;
 
         assert(bus);
@@ -258,7 +263,9 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
                         fds = f;
                         memcpy(fds + n_fds, d->fds, j);
                         n_fds += j;
-                }
+
+                } else if (d->type == KDBUS_MSG_SRC_CREDS)
+                        creds = &d->creds;
         }
 
         if (!h)
@@ -282,14 +289,14 @@ 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;
                 }
@@ -297,6 +304,14 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k, sd_bus_mess
                 idx += l;
         }
 
+        if (creds) {
+                m->uid = creds->uid;
+                m->gid = creds->gid;
+                m->pid = creds->pid;
+                m->tid = creds->tid;
+                m->uid_valid = m->gid_valid = true;
+        }
+
         r = bus_message_parse_fields(m);
         if (r < 0) {
                 sd_bus_message_unref(m);
@@ -339,7 +354,7 @@ 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;
@@ -378,7 +393,7 @@ int bus_kernel_create(const char *name, char **s) {
         if (!p)
                 return -ENOMEM;
 
-        if (ioctl(fd, KDBUS_CMD_BUS_MAKE, &fname) < 0) {
+        if (ioctl(fd, KDBUS_CMD_BUS_MAKE, fname) < 0) {
                 close_nointr_nofail(fd);
                 free(p);
                 return -errno;