sd-bus: when we get ENOTTY on the HELLO ioctl assume incompatible API version

As perparation for future incompatible kdbus kernel API changes.

1 files changed, 5 insertions, 2 deletions

diff --git a/src/core/bus-policy.c b/src/core/bus-policy.c
index 064eee1c8a..a6a8fcd4d3 100644
--- a/src/core/bus-policy.c
+++ b/src/core/bus-policy.c
@@ -150,8 +150,11 @@ int bus_kernel_make_starter(
         hello->attach_flags_send = _KDBUS_ATTACH_ANY;
         hello->attach_flags_recv = _KDBUS_ATTACH_ANY;
 
-        if (ioctl(fd, KDBUS_CMD_HELLO, hello) < 0)
+        if (ioctl(fd, KDBUS_CMD_HELLO, hello) < 0) {
+                if (errno == ENOTTY) /* Major API change */
+                        return -ESOCKTNOSUPPORT;
                 return -errno;
+        }
 
         /* not interested in any output values */
         cmd_free.offset = hello->offset;
@@ -160,7 +163,7 @@ int bus_kernel_make_starter(
         /* The higher 32bit of the bus_flags fields are considered
          * 'incompatible flags'. Refuse them all for now. */
         if (hello->bus_flags > 0xFFFFFFFFULL)
-                return -EOPNOTSUPP;
+                return -ESOCKTNOSUPPORT;
 
         return fd;
 }