#define DEBUGP(format, args...)
#endif
-static u_int16_t
-cheat_check(u_int32_t oldvalinv, u_int32_t newval, u_int16_t oldcheck)
-{
- u_int32_t diffs[] = { oldvalinv, newval };
- return csum_fold(csum_partial((char *)diffs, sizeof(diffs),
- oldcheck^0xFFFF));
-}
-
static inline unsigned int
optlen(const u_int8_t *opt, unsigned int offset)
{
const struct net_device *out,
unsigned int hooknum,
const struct xt_target *target,
- const void *targinfo,
- void *userinfo)
+ const void *targinfo)
{
const struct ipt_tcpmss_info *tcpmssinfo = targinfo;
struct tcphdr *tcph;
if (!skb_make_writable(pskb, (*pskb)->len))
return NF_DROP;
- if ((*pskb)->ip_summed == CHECKSUM_HW &&
- skb_checksum_help(*pskb, out == NULL))
- return NF_DROP;
-
iph = (*pskb)->nh.iph;
tcplen = (*pskb)->len - iph->ihl*4;
opt[i+2] = (newmss & 0xff00) >> 8;
opt[i+3] = (newmss & 0x00ff);
- tcph->check = cheat_check(htons(oldmss)^0xFFFF,
- htons(newmss),
- tcph->check);
+ tcph->check = nf_proto_csum_update(*pskb,
+ htons(oldmss)^0xFFFF,
+ htons(newmss),
+ tcph->check, 0);
DEBUGP(KERN_INFO "ipt_tcpmss_target: %u.%u.%u.%u:%hu"
"->%u.%u.%u.%u:%hu changed TCP MSS option"
opt = (u_int8_t *)tcph + sizeof(struct tcphdr);
memmove(opt + TCPOLEN_MSS, opt, tcplen - sizeof(struct tcphdr));
- tcph->check = cheat_check(htons(tcplen) ^ 0xFFFF,
- htons(tcplen + TCPOLEN_MSS), tcph->check);
+ tcph->check = nf_proto_csum_update(*pskb,
+ htons(tcplen) ^ 0xFFFF,
+ htons(tcplen + TCPOLEN_MSS),
+ tcph->check, 1);
tcplen += TCPOLEN_MSS;
opt[0] = TCPOPT_MSS;
opt[2] = (newmss & 0xff00) >> 8;
opt[3] = (newmss & 0x00ff);
- tcph->check = cheat_check(~0, *((u_int32_t *)opt), tcph->check);
+ tcph->check = nf_proto_csum_update(*pskb, ~0, *((u_int32_t *)opt),
+ tcph->check, 0);
oldval = ((u_int16_t *)tcph)[6];
tcph->doff += TCPOLEN_MSS/4;
- tcph->check = cheat_check(oldval ^ 0xFFFF,
- ((u_int16_t *)tcph)[6], tcph->check);
+ tcph->check = nf_proto_csum_update(*pskb,
+ oldval ^ 0xFFFF,
+ ((u_int16_t *)tcph)[6],
+ tcph->check, 0);
newtotlen = htons(ntohs(iph->tot_len) + TCPOLEN_MSS);
- iph->check = cheat_check(iph->tot_len ^ 0xFFFF,
- newtotlen, iph->check);
+ iph->check = nf_csum_update(iph->tot_len ^ 0xFFFF,
+ newtotlen, iph->check);
iph->tot_len = newtotlen;
DEBUGP(KERN_INFO "ipt_tcpmss_target: %u.%u.%u.%u:%hu"