[PATCH 08/25] net: core: add function for incremental IPv6 pseudo header checksum updates
From: pablo@netfilter.org
Date: 2012-09-03 23:55:44
Also in:
netfilter-devel
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Patrick McHardy <redacted> Add inet_proto_csum_replace16 for incrementally updating IPv6 pseudo header checksums for IPv6 NAT. Signed-off-by: Patrick McHardy <redacted> Acked-by: David S. Miller <davem@davemloft.net> --- include/net/checksum.h | 3 +++ net/core/utils.c | 20 ++++++++++++++++++++ 2 files changed, 23 insertions(+)
diff --git a/include/net/checksum.h b/include/net/checksum.h
index ba55d8b..600d1d7 100644
--- a/include/net/checksum.h
+++ b/include/net/checksum.h@@ -109,6 +109,9 @@ static inline void csum_replace2(__sum16 *sum, __be16 from, __be16 to) struct sk_buff; extern void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb, __be32 from, __be32 to, int pseudohdr); +extern void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb, + const __be32 *from, const __be32 *to, + int pseudohdr); static inline void inet_proto_csum_replace2(__sum16 *sum, struct sk_buff *skb, __be16 from, __be16 to,
diff --git a/net/core/utils.c b/net/core/utils.c
index 39895a6..f5613d5 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;
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1.7.10.4