From 2cf545e835aae92173ef0b1f4af385e9c40f21e8 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Sun, 26 Aug 2012 19:14:10 +0200 Subject: net: core: add function for incremental IPv6 pseudo header checksum updates Add inet_proto_csum_replace16 for incrementally updating IPv6 pseudo header checksums for IPv6 NAT. Signed-off-by: Patrick McHardy Acked-by: David S. Miller --- net/core/utils.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'net/core') diff --git a/net/core/utils.c b/net/core/utils.c index 39895a65e54a..f5613d569c23 100644 --- a/net/core/utils.c +++ b/net/core/utils.c @@ -294,6 +294,26 @@ void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb, } EXPORT_SYMBOL(inet_proto_csum_replace4); +void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb, + const __be32 *from, const __be32 *to, + int pseudohdr) +{ + __be32 diff[] = { + ~from[0], ~from[1], ~from[2], ~from[3], + to[0], to[1], to[2], to[3], + }; + if (skb->ip_summed != CHECKSUM_PARTIAL) { + *sum = csum_fold(csum_partial(diff, sizeof(diff), + ~csum_unfold(*sum))); + if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr) + skb->csum = ~csum_partial(diff, sizeof(diff), + ~skb->csum); + } else if (pseudohdr) + *sum = ~csum_fold(csum_partial(diff, sizeof(diff), + csum_unfold(*sum))); +} +EXPORT_SYMBOL(inet_proto_csum_replace16); + int mac_pton(const char *s, u8 *mac) { int i; -- cgit v1.2.3