diff options
| author | Patrick McHardy <kaber@trash.net> | 2008-03-20 15:15:53 +0100 |
|---|---|---|
| committer | Patrick McHardy <kaber@trash.net> | 2008-04-14 11:15:49 +0200 |
| commit | d63a650736f566a1f9e9434725d2089597c0d2cc (patch) | |
| tree | f0a3d5dbc9ced46f95582e4133b55bb70a1ae365 /net/ipv6 | |
| parent | 6185f870e293a0a3eae5c81eb0106480cf03dfde (diff) | |
[NETFILTER]: Add partial checksum validation helper
Move the UDP-Lite conntrack checksum validation to a generic helper
similar to nf_checksum() and make it fall back to nf_checksum()
in case the full packet is to be checksummed and hardware checksums
are available. This is to be used by DCCP conntrack, which also
needs to verify partial checksums.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/netfilter.c | 42 |
1 files changed, 35 insertions, 7 deletions
diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c index aed51bcc66b4..8c6c5e71f210 100644 --- a/net/ipv6/netfilter.c +++ b/net/ipv6/netfilter.c @@ -121,16 +121,44 @@ __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook, } return csum; } - EXPORT_SYMBOL(nf_ip6_checksum); +static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook, + unsigned int dataoff, unsigned int len, + u_int8_t protocol) +{ + struct ipv6hdr *ip6h = ipv6_hdr(skb); + __wsum hsum; + __sum16 csum = 0; + + switch (skb->ip_summed) { + case CHECKSUM_COMPLETE: + if (len == skb->len - dataoff) + return nf_ip6_checksum(skb, hook, dataoff, protocol); + /* fall through */ + case CHECKSUM_NONE: + hsum = skb_checksum(skb, 0, dataoff, 0); + skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr, + &ip6h->daddr, + skb->len - dataoff, + protocol, + csum_sub(0, hsum))); + skb->ip_summed = CHECKSUM_NONE; + csum = __skb_checksum_complete_head(skb, dataoff + len); + if (!csum) + skb->ip_summed = CHECKSUM_UNNECESSARY; + } + return csum; +}; + static const struct nf_afinfo nf_ip6_afinfo = { - .family = AF_INET6, - .checksum = nf_ip6_checksum, - .route = nf_ip6_route, - .saveroute = nf_ip6_saveroute, - .reroute = nf_ip6_reroute, - .route_key_size = sizeof(struct ip6_rt_info), + .family = AF_INET6, + .checksum = nf_ip6_checksum, + .checksum_partial = nf_ip6_checksum_partial, + .route = nf_ip6_route, + .saveroute = nf_ip6_saveroute, + .reroute = nf_ip6_reroute, + .route_key_size = sizeof(struct ip6_rt_info), }; int __init ipv6_netfilter_init(void) |