From mboxrd@z Thu Jan 1 00:00:00 1970 From: kaber@trash.net Subject: [PATCH 11/17] net: core: add function for incremental IPv6 pseudo header checksum updates Date: Mon, 21 Nov 2011 06:46:03 +0100 Message-ID: <1321854369-3432-12-git-send-email-kaber@trash.net> References: <1321854369-3432-1-git-send-email-kaber@trash.net> Cc: netdev@vger.kernel.org, kaber@trash.net, ulrich.weber@sophos.com To: netfilter-devel@vger.kernel.org Return-path: In-Reply-To: <1321854369-3432-1-git-send-email-kaber@trash.net> Sender: netdev-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org From: Patrick McHardy Add inet_proto_csum_replace16 for incrementally updating IPv6 pseudo header checksums for IPv6 NAT. Signed-off-by: Patrick McHardy --- include/net/checksum.h | 3 +++ net/core/utils.c | 20 ++++++++++++++++++++ 2 files changed, 23 insertions(+), 0 deletions(-) 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 386e263..b09a73a 100644 --- a/net/core/utils.c +++ b/net/core/utils.c @@ -298,6 +298,26 @@ 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; -- 1.7.1