udp: Generic functions to set checksum

Added udp_set_csum and udp6_set_csum functions to set UDP checksums
in packets. These are for simple UDP packets such as those that might
be created in UDP tunnels.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/net/udp.h b/include/net/udp.h
index 5eb86874bcd6..2ecfc6e15609 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -147,6 +147,15 @@ static inline __wsum udp_csum(struct sk_buff *skb)
         return csum;
 }
 
+static inline __sum16 udp_v4_check(int len, __be32 saddr,
+                                   __be32 daddr, __wsum base)
+{
+        return csum_tcpudp_magic(saddr, daddr, len, IPPROTO_UDP, base);
+}
+
+void udp_set_csum(bool nocheck, struct sk_buff *skb,
+                  __be32 saddr, __be32 daddr, int len);
+
 /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
 static inline void udp_lib_hash(struct sock *sk)
 {