diff options
| author | Patrick McHardy <kaber@trash.net> | 2006-04-06 14:18:43 -0700 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2006-04-09 22:25:41 -0700 |
| commit | 422c346fad806e2abaeffac686860ebc98dfe33e (patch) | |
| tree | dd554d11e80ad33afef4b438ec4c2d8943ad37f4 /net | |
| parent | bce8032ef3cc58170ab3550e9e271dba7b4c4764 (diff) | |
| download | lwn-422c346fad806e2abaeffac686860ebc98dfe33e.tar.gz lwn-422c346fad806e2abaeffac686860ebc98dfe33e.zip | |
[NETFILTER]: Add address family specific checksum helpers
Add checksum operation which takes care of verifying the checksum and
dealing with HW checksum errors and avoids multiple checksum
operations by setting ip_summed to CHECKSUM_UNNECESSARY after
successful verification.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/netfilter.c | 33 | ||||
| -rw-r--r-- | net/ipv6/netfilter.c | 34 |
2 files changed, 67 insertions, 0 deletions
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c index b25339c11ea0..6a9e34b794bc 100644 --- a/net/ipv4/netfilter.c +++ b/net/ipv4/netfilter.c @@ -161,8 +161,41 @@ static int nf_ip_reroute(struct sk_buff **pskb, const struct nf_info *info) return 0; } +unsigned int nf_ip_checksum(struct sk_buff *skb, unsigned int hook, + unsigned int dataoff, u_int8_t protocol) +{ + struct iphdr *iph = skb->nh.iph; + unsigned int csum = 0; + + switch (skb->ip_summed) { + case CHECKSUM_HW: + if (hook != NF_IP_PRE_ROUTING && hook != NF_IP_LOCAL_IN) + break; + if ((protocol == 0 && !(u16)csum_fold(skb->csum)) || + !csum_tcpudp_magic(iph->saddr, iph->daddr, + skb->len - dataoff, protocol, + skb->csum)) { + skb->ip_summed = CHECKSUM_UNNECESSARY; + break; + } + /* fall through */ + case CHECKSUM_NONE: + if (protocol == 0) + skb->csum = 0; + else + skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, + skb->len - dataoff, + protocol, 0); + csum = __skb_checksum_complete(skb); + } + return csum; +} + +EXPORT_SYMBOL(nf_ip_checksum); + static struct nf_afinfo nf_ip_afinfo = { .family = AF_INET, + .checksum = nf_ip_checksum, .saveroute = nf_ip_saveroute, .reroute = nf_ip_reroute, .route_key_size = sizeof(struct ip_rt_info), diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c index f514a0113b9f..3e9ecfaf67e2 100644 --- a/net/ipv6/netfilter.c +++ b/net/ipv6/netfilter.c @@ -79,8 +79,42 @@ static int nf_ip6_reroute(struct sk_buff **pskb, const struct nf_info *info) return 0; } +unsigned int nf_ip6_checksum(struct sk_buff *skb, unsigned int hook, + unsigned int dataoff, u_int8_t protocol) +{ + struct ipv6hdr *ip6h = skb->nh.ipv6h; + unsigned int csum = 0; + + switch (skb->ip_summed) { + case CHECKSUM_HW: + if (hook != NF_IP6_PRE_ROUTING && hook != NF_IP6_LOCAL_IN) + break; + if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, + skb->len - dataoff, protocol, + csum_sub(skb->csum, + skb_checksum(skb, 0, + dataoff, 0)))) { + skb->ip_summed = CHECKSUM_UNNECESSARY; + break; + } + /* fall through */ + case CHECKSUM_NONE: + skb->csum = ~csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, + skb->len - dataoff, + protocol, + csum_sub(0, + skb_checksum(skb, 0, + dataoff, 0))); + csum = __skb_checksum_complete(skb); + } + return csum; +} + +EXPORT_SYMBOL(nf_ip6_checksum); + static struct nf_afinfo nf_ip6_afinfo = { .family = AF_INET6, + .checksum = nf_ip6_checksum, .saveroute = nf_ip6_saveroute, .reroute = nf_ip6_reroute, .route_key_size = sizeof(struct ip6_rt_info), |