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/ipv4 | |
| 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/ipv4')
| -rw-r--r-- | net/ipv4/netfilter.c | 37 |
1 files changed, 30 insertions, 7 deletions
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c index 9a904c6c0dc..f8edacdf991 100644 --- a/net/ipv4/netfilter.c +++ b/net/ipv4/netfilter.c @@ -182,21 +182,44 @@ __sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook, } return csum; } - EXPORT_SYMBOL(nf_ip_checksum); +static __sum16 nf_ip_checksum_partial(struct sk_buff *skb, unsigned int hook, + unsigned int dataoff, unsigned int len, + u_int8_t protocol) +{ + const struct iphdr *iph = ip_hdr(skb); + __sum16 csum = 0; + + switch (skb->ip_summed) { + case CHECKSUM_COMPLETE: + if (len == skb->len - dataoff) + return nf_ip_checksum(skb, hook, dataoff, protocol); + /* fall through */ + case CHECKSUM_NONE: + skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, protocol, + skb->len - dataoff, 0); + skb->ip_summed = CHECKSUM_NONE; + csum = __skb_checksum_complete_head(skb, dataoff + len); + if (!csum) + skb->ip_summed = CHECKSUM_UNNECESSARY; + } + return csum; +} + static int nf_ip_route(struct dst_entry **dst, struct flowi *fl) { return ip_route_output_key(&init_net, (struct rtable **)dst, fl); } static const struct nf_afinfo nf_ip_afinfo = { - .family = AF_INET, - .checksum = nf_ip_checksum, - .route = nf_ip_route, - .saveroute = nf_ip_saveroute, - .reroute = nf_ip_reroute, - .route_key_size = sizeof(struct ip_rt_info), + .family = AF_INET, + .checksum = nf_ip_checksum, + .checksum_partial = nf_ip_checksum_partial, + .route = nf_ip_route, + .saveroute = nf_ip_saveroute, + .reroute = nf_ip_reroute, + .route_key_size = sizeof(struct ip_rt_info), }; static int ipv4_netfilter_init(void) |