X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Flibsystemd%2Fsd-bus%2Fbus-convenience.c;h=ae0f4fa217777cca1450ff60b37b1d70adbd80a7;hp=c5b9cd4caaf812252ad85542d65b90e3e4ef0494;hb=75e52a16f9ef476f1d18ec6d9c84e00149b80d03;hpb=a3d59cd1b0a2738d06893948492113f2c35be0af

diff --git a/src/libsystemd/sd-bus/bus-convenience.c b/src/libsystemd/sd-bus/bus-convenience.c
index c5b9cd4ca..ae0f4fa21 100644
--- a/src/libsystemd/sd-bus/bus-convenience.c
+++ b/src/libsystemd/sd-bus/bus-convenience.c
@@ -465,10 +465,68 @@ _public_ int sd_bus_query_sender_creds(sd_bus_message *call, uint64_t mask, sd_b
                  * to get it from the sender or peer */
 
                 if (call->sender)
-                        return sd_bus_get_owner(call->bus, call->sender, mask, creds);
+                        return sd_bus_get_name_creds(call->bus, call->sender, mask, creds);
                 else
-                        return sd_bus_get_peer_creds(call->bus, mask, creds);
+                        return sd_bus_get_owner_creds(call->bus, mask, creds);
         }
 
         return bus_creds_extend_by_pid(c, mask, creds);
 }
+
+_public_ int sd_bus_query_sender_privilege(sd_bus_message *call, int capability) {
+        _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+        uid_t our_uid;
+        bool know_caps = false;
+        int r;
+
+        assert_return(call, -EINVAL);
+        assert_return(call->sealed, -EPERM);
+        assert_return(call->bus, -EINVAL);
+        assert_return(!bus_pid_changed(call->bus), -ECHILD);
+
+        if (!BUS_IS_OPEN(call->bus->state))
+                return -ENOTCONN;
+
+        if (capability >= 0) {
+                r = sd_bus_query_sender_creds(call, SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID|SD_BUS_CREDS_EFFECTIVE_CAPS, &creds);
+                if (r < 0)
+                        return r;
+
+                /* Note that not even on kdbus we might have the caps
+                 * field, due to faked identities, or namespace
+                 * translation issues. */
+                r = sd_bus_creds_has_effective_cap(creds, capability);
+                if (r > 0)
+                        return 1;
+                if (r == 0)
+                        know_caps = true;
+        } else {
+                r = sd_bus_query_sender_creds(call, SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID, &creds);
+                if (r < 0)
+                        return r;
+        }
+
+        /* Now, check the UID, but only if the capability check wasn't
+         * sufficient */
+        our_uid = getuid();
+        if (our_uid != 0 || !know_caps || capability < 0) {
+                uid_t sender_uid;
+
+                /* Try to use the EUID, if we have it. */
+                r = sd_bus_creds_get_euid(creds, &sender_uid);
+                if (r < 0)
+                        r = sd_bus_creds_get_uid(creds, &sender_uid);
+
+                if (r >= 0) {
+                        /* Sender has same UID as us, then let's grant access */
+                        if (sender_uid == our_uid)
+                                return 1;
+
+                        /* Sender is root, we are not root. */
+                        if (our_uid != 0 && sender_uid == 0)
+                                return 1;
+                }
+        }
+
+        return 0;
+}