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[NETFILTER]: nf_nat: use HW checksumming when possible 

When mangling packets forwarded to a HW checksumming capable device,
offload recalculation of the checksum instead of doing it in software.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2007-04-12 22:15:50 -07:00 committed by David S. Miller
parent c15bf6e699
commit fe6092ea00
1 changed files with 37 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

49
net/ipv4/netfilter/nf_nat_helper.c
View File

@ -153,6 +153,7 @@ nf_nat_mangle_tcp_packet(struct sk_buff **pskb,
const char *rep_buffer,
unsigned int rep_len)
{
struct rtable *rt = (struct rtable *)(*pskb)->dst;
struct iphdr *iph;
struct tcphdr *tcph;
int oldlen, datalen;
@ -176,11 +177,22 @@ nf_nat_mangle_tcp_packet(struct sk_buff **pskb,
datalen = (*pskb)->len - iph->ihl*4;
if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) {
tcph->check = 0;
tcph->check = tcp_v4_check(datalen,
iph->saddr, iph->daddr,
csum_partial((char *)tcph,
datalen, 0));
if (!(rt->rt_flags & RTCF_LOCAL) &&
(*pskb)->dev->features & NETIF_F_ALL_CSUM) {
(*pskb)->ip_summed = CHECKSUM_PARTIAL;
(*pskb)->csum_start = skb_headroom(*pskb) +
skb_network_offset(*pskb) +
iph->ihl * 4;
(*pskb)->csum_offset = offsetof(struct tcphdr, check);
tcph->check = ~tcp_v4_check(datalen,
iph->saddr, iph->daddr, 0);
} else {
tcph->check = 0;
tcph->check = tcp_v4_check(datalen,
iph->saddr, iph->daddr,
csum_partial((char *)tcph,
datalen, 0));
}
} else
nf_proto_csum_replace2(&tcph->check, *pskb,
htons(oldlen), htons(datalen), 1);
@ -217,6 +229,7 @@ nf_nat_mangle_udp_packet(struct sk_buff **pskb,
const char *rep_buffer,
unsigned int rep_len)
{
struct rtable *rt = (struct rtable *)(*pskb)->dst;
struct iphdr *iph;
struct udphdr *udph;
int datalen, oldlen;
@ -251,13 +264,25 @@ nf_nat_mangle_udp_packet(struct sk_buff **pskb,
return 1;
if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) {
udph->check = 0;
udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
datalen, IPPROTO_UDP,
csum_partial((char *)udph,
datalen, 0));
if (!udph->check)
udph->check = CSUM_MANGLED_0;
if (!(rt->rt_flags & RTCF_LOCAL) &&
(*pskb)->dev->features & NETIF_F_ALL_CSUM) {
(*pskb)->ip_summed = CHECKSUM_PARTIAL;
(*pskb)->csum_start = skb_headroom(*pskb) +
skb_network_offset(*pskb) +
iph->ihl * 4;
(*pskb)->csum_offset = offsetof(struct udphdr, check);
udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
datalen, IPPROTO_UDP,
0);
} else {
udph->check = 0;
udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
datalen, IPPROTO_UDP,
csum_partial((char *)udph,
datalen, 0));
if (!udph->check)
udph->check = CSUM_MANGLED_0;
}
} else
nf_proto_csum_replace2(&udph->check, *pskb,
htons(oldlen), htons(datalen), 1);