vserver 1.9.5.x5

[linux-2.6.git] / net / ipv4 / netfilter / ipt_ECN.c

diff --git a/net/ipv4/netfilter/ipt_ECN.c b/net/ipv4/netfilter/ipt_ECN.c
index 341e845..ada9911 100644 (file)
--- a/net/ipv4/netfilter/ipt_ECN.c
+++ b/net/ipv4/netfilter/ipt_ECN.c
@@ -50,37 +50,43 @@ set_ect_ip(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
 
 /* Return 0 if there was an error. */
 static inline int
-set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
+set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo, int inward)
 {
-       struct tcphdr tcph;
+       struct tcphdr _tcph, *tcph;
        u_int16_t diffs[2];
 
        /* Not enought header? */
-       if (skb_copy_bits(*pskb, (*pskb)->nh.iph->ihl*4, &tcph, sizeof(tcph))
-           < 0)
+       tcph = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl*4,
+                                 sizeof(_tcph), &_tcph);
+       if (!tcph)
                return 0;
 
-       diffs[0] = ((u_int16_t *)&tcph)[6];
-       if (einfo->operation & IPT_ECN_OP_SET_ECE)
-               tcph.ece = einfo->proto.tcp.ece;
+       if (!(einfo->operation & IPT_ECN_OP_SET_ECE
+             || tcph->ece == einfo->proto.tcp.ece)
+           && (!(einfo->operation & IPT_ECN_OP_SET_CWR
+                 || tcph->cwr == einfo->proto.tcp.cwr)))
+               return 1;
+
+       if (!skb_ip_make_writable(pskb, (*pskb)->nh.iph->ihl*4+sizeof(*tcph)))
+               return 0;
+       tcph = (void *)(*pskb)->nh.iph + (*pskb)->nh.iph->ihl*4;
 
+       diffs[0] = ((u_int16_t *)tcph)[6];
+       if (einfo->operation & IPT_ECN_OP_SET_ECE)
+               tcph->ece = einfo->proto.tcp.ece;
        if (einfo->operation & IPT_ECN_OP_SET_CWR)
-               tcph.cwr = einfo->proto.tcp.cwr;
-       diffs[1] = ((u_int16_t *)&tcph)[6];
-
-       /* Only mangle if it's changed. */
-       if (diffs[0] != diffs[1]) {
-               diffs[0] = diffs[0] ^ 0xFFFF;
-               if (!skb_ip_make_writable(pskb,
-                                         (*pskb)->nh.iph->ihl*4+sizeof(tcph)))
+               tcph->cwr = einfo->proto.tcp.cwr;
+       diffs[1] = ((u_int16_t *)tcph)[6];
+       diffs[0] = diffs[0] ^ 0xFFFF;
+
+       if ((*pskb)->ip_summed != CHECKSUM_HW)
+               tcph->check = csum_fold(csum_partial((char *)diffs,
+                                                    sizeof(diffs),
+                                                    tcph->check^0xFFFF));
+       else
+               if (skb_checksum_help(*pskb, inward))
                        return 0;
-               tcph.check = csum_fold(csum_partial((char *)diffs,
-                                                   sizeof(diffs),
-                                                   tcph.check^0xFFFF));
-               memcpy((*pskb)->data + (*pskb)->nh.iph->ihl*4,
-                      &tcph, sizeof(tcph));
-               (*pskb)->nfcache |= NFC_ALTERED;
-       }
+       (*pskb)->nfcache |= NFC_ALTERED;
        return 1;
 }
 
@@ -100,7 +106,7 @@ target(struct sk_buff **pskb,
 
        if (einfo->operation & (IPT_ECN_OP_SET_ECE | IPT_ECN_OP_SET_CWR)
            && (*pskb)->nh.iph->protocol == IPPROTO_TCP)
-               if (!set_ect_tcp(pskb, einfo))
+               if (!set_ect_tcp(pskb, einfo, (out == NULL)))
                        return NF_DROP;
 
        return IPT_CONTINUE;
@@ -139,7 +145,7 @@ checkentry(const char *tablename,
        }
 
        if ((einfo->operation & (IPT_ECN_OP_SET_ECE|IPT_ECN_OP_SET_CWR))
-           && e->ip.proto != IPPROTO_TCP) {
+           && (e->ip.proto != IPPROTO_TCP || (e->ip.invflags & IPT_INV_PROTO))) {
                printk(KERN_WARNING "ECN: cannot use TCP operations on a "
                       "non-tcp rule\n");
                return 0;