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[NETFILTER]: replace open coded checksum updates

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Replace open coded checksum update by nf_csum_update calls and clean up
the surrounding code a bit.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2006-08-22 00:33:09 -07:00 committed by David S. Miller
parent 1158ba27be
commit da878c8e5a
3 changed files with 20 additions and 33 deletions
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22
net/ipv4/netfilter/ipt_ECN.c
View file

@ -27,22 +27,18 @@ MODULE_DESCRIPTION("iptables ECN modification module");
static inline int
set_ect_ip(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
{
if (((*pskb)->nh.iph->tos & IPT_ECN_IP_MASK)
!= (einfo->ip_ect & IPT_ECN_IP_MASK)) {
u_int16_t diffs[2];
struct iphdr *iph = (*pskb)->nh.iph;
u_int16_t oldtos;
if ((iph->tos & IPT_ECN_IP_MASK) != (einfo->ip_ect & IPT_ECN_IP_MASK)) {
if (!skb_make_writable(pskb, sizeof(struct iphdr)))
return 0;
diffs[0] = htons((*pskb)->nh.iph->tos) ^ 0xFFFF;
(*pskb)->nh.iph->tos &= ~IPT_ECN_IP_MASK;
(*pskb)->nh.iph->tos |= (einfo->ip_ect & IPT_ECN_IP_MASK);
diffs[1] = htons((*pskb)->nh.iph->tos);
(*pskb)->nh.iph->check
= csum_fold(csum_partial((char *)diffs,
sizeof(diffs),
(*pskb)->nh.iph->check
^0xFFFF));
iph = (*pskb)->nh.iph;
oldtos = iph->tos;
iph->tos &= ~IPT_ECN_IP_MASK;
iph->tos |= (einfo->ip_ect & IPT_ECN_IP_MASK);
iph->check = nf_csum_update(oldtos ^ 0xFFFF, iph->tos,
iph->check);
}
return 1;
}

22
net/ipv4/netfilter/ipt_TOS.c
View file

@ -30,23 +30,17 @@ target(struct sk_buff **pskb,
void *userinfo)
{
const struct ipt_tos_target_info *tosinfo = targinfo;
struct iphdr *iph = (*pskb)->nh.iph;
u_int16_t oldtos;
if (((*pskb)->nh.iph->tos & IPTOS_TOS_MASK) != tosinfo->tos) {
u_int16_t diffs[2];
if ((iph->tos & IPTOS_TOS_MASK) != tosinfo->tos) {
if (!skb_make_writable(pskb, sizeof(struct iphdr)))
return NF_DROP;
diffs[0] = htons((*pskb)->nh.iph->tos) ^ 0xFFFF;
(*pskb)->nh.iph->tos
= ((*pskb)->nh.iph->tos & IPTOS_PREC_MASK)
| tosinfo->tos;
diffs[1] = htons((*pskb)->nh.iph->tos);
(*pskb)->nh.iph->check
= csum_fold(csum_partial((char *)diffs,
sizeof(diffs),
(*pskb)->nh.iph->check
^0xFFFF));
iph = (*pskb)->nh.iph;
oldtos = iph->tos;
iph->tos = (iph->tos & IPTOS_PREC_MASK) | tosinfo->tos;
iph->check = nf_csum_update(oldtos ^ 0xFFFF, iph->tos,
iph->check);
}
return IPT_CONTINUE;
}

9
net/ipv4/netfilter/ipt_TTL.c
View file

@ -27,7 +27,6 @@ ipt_ttl_target(struct sk_buff **pskb,
{
struct iphdr *iph;
const struct ipt_TTL_info *info = targinfo;
u_int16_t diffs[2];
int new_ttl;
if (!skb_make_writable(pskb, (*pskb)->len))
@ -55,12 +54,10 @@ ipt_ttl_target(struct sk_buff **pskb,
}
if (new_ttl != iph->ttl) {
diffs[0] = htons(((unsigned)iph->ttl) << 8) ^ 0xFFFF;
iph->check = nf_csum_update((iph->ttl << 8) ^ 0xFFFF,
new_ttl << 8,
iph->check);
iph->ttl = new_ttl;
diffs[1] = htons(((unsigned)iph->ttl) << 8);
iph->check = csum_fold(csum_partial((char *)diffs,
sizeof(diffs),
iph->check^0xFFFF));
}
return IPT_CONTINUE;