BFD: Add option to accept zero checksum for IPv6 UDP packets

Some vendors do not fill the checksum for IPv6 UDP packets.
For interoperability with such implementations one can set
UDP_NO_CHECK6_RX socket option on Linux.

Thanks to Ville O for the suggestion.

Minor changes by committer.

1 files changed, 9 insertions, 0 deletions

diff --git a/sysdep/linux/sysio.h b/sysdep/linux/sysio.h
index f13eda7c..5e71b535 100644
--- a/sysdep/linux/sysio.h
+++ b/sysdep/linux/sysio.h
@@ -285,3 +285,12 @@ sk_set_freebind(sock *s)
 
   return 0;
 }
+
+static inline int
+sk_set_udp6_no_csum_rx(sock *s)
+{
+  int y = 1;
+
+  if (setsockopt(s->fd, SOL_UDP, UDP_NO_CHECK6_RX, &y, sizeof(y)) < 0)
+    ERR("UDP_NO_CHECK6_RX");
+}