diff options
Diffstat (limited to 'net/ipv4/netfilter/ipt_TCPMSS.c')
| -rw-r--r-- | net/ipv4/netfilter/ipt_TCPMSS.c | 39 |
1 files changed, 16 insertions, 23 deletions
diff --git a/net/ipv4/netfilter/ipt_TCPMSS.c b/net/ipv4/netfilter/ipt_TCPMSS.c index c998dc0fcd159..0fce85e055071 100644 --- a/net/ipv4/netfilter/ipt_TCPMSS.c +++ b/net/ipv4/netfilter/ipt_TCPMSS.c @@ -27,14 +27,6 @@ MODULE_DESCRIPTION("iptables TCP MSS modification module"); #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) { @@ -62,11 +54,6 @@ ipt_tcpmss_target(struct sk_buff **pskb, if (!skb_make_writable(pskb, (*pskb)->len)) return NF_DROP; - if (((*pskb)->ip_summed == CHECKSUM_PARTIAL || - (*pskb)->ip_summed == CHECKSUM_COMPLETE) && - skb_checksum_help(*pskb)) - return NF_DROP; - iph = (*pskb)->nh.iph; tcplen = (*pskb)->len - iph->ihl*4; @@ -120,9 +107,10 @@ ipt_tcpmss_target(struct sk_buff **pskb, 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" @@ -162,8 +150,10 @@ ipt_tcpmss_target(struct sk_buff **pskb, 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; @@ -171,16 +161,19 @@ ipt_tcpmss_target(struct sk_buff **pskb, 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" |