zebra: check at startup if the kernel supports MPLS

Replace all HAVE_MPLS #ifdef's by a run-time check if MPLS is supported
by the kernel or not. This way we don't need to create multiple packages
for each OS distribution.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

1 files changed, 13 insertions, 1 deletions

diff --git a/zebra/zebra_mpls_netlink.c b/zebra/zebra_mpls_netlink.c
index 4011b90eea..1f894b33c6 100644
--- a/zebra/zebra_mpls_netlink.c
+++ b/zebra/zebra_mpls_netlink.c
@@ -77,4 +77,16 @@ kernel_del_lsp (zebra_lsp_t *lsp)
   return 0;
 }
 
-void mpls_kernel_init (void) {};
+int
+mpls_kernel_init (void)
+{
+  struct stat st;
+
+  /*
+   * Check if the MPLS module is loaded in the kernel.
+   */
+  if (stat ("/proc/sys/net/mpls", &st) != 0)
+    return -1;
+
+  return 0;
+};