linux 2.6.16.38 w/ vs2.0.3-rc1
[linux-2.6.git] / net / ipv4 / netfilter / ipt_ECN.c
index f659ec3..7064454 100644 (file)
@@ -31,7 +31,7 @@ set_ect_ip(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
            != (einfo->ip_ect & IPT_ECN_IP_MASK)) {
                u_int16_t diffs[2];
 
-               if (!skb_ip_make_writable(pskb, sizeof(struct iphdr)))
+               if (!skb_make_writable(pskb, sizeof(struct iphdr)))
                        return 0;
 
                diffs[0] = htons((*pskb)->nh.iph->tos) ^ 0xFFFF;
@@ -43,7 +43,6 @@ set_ect_ip(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
                                                 sizeof(diffs),
                                                 (*pskb)->nh.iph->check
                                                 ^0xFFFF));
-               (*pskb)->nfcache |= NFC_ALTERED;
        } 
        return 1;
 }
@@ -52,44 +51,41 @@ set_ect_ip(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
 static inline int
 set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo, int inward)
 {
-       struct tcphdr _tcph, *th;
+       struct tcphdr _tcph, *tcph;
        u_int16_t diffs[2];
 
        /* Not enought header? */
-       th = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl*4,
-                               sizeof(_tcph), &_tcph);
-       if (th == NULL)
+       tcph = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl*4,
+                                 sizeof(_tcph), &_tcph);
+       if (!tcph)
                return 0;
 
-       diffs[0] = ((u_int16_t *)th)[6];
-       if (einfo->operation & IPT_ECN_OP_SET_ECE)
-               th->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 (einfo->operation & IPT_ECN_OP_SET_CWR)
-               th->cwr = einfo->proto.tcp.cwr;
-       diffs[1] = ((u_int16_t *)&th)[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)))
-                       return 0;
+       if (!skb_make_writable(pskb, (*pskb)->nh.iph->ihl*4+sizeof(*tcph)))
+               return 0;
+       tcph = (void *)(*pskb)->nh.iph + (*pskb)->nh.iph->ihl*4;
 
-               if (th != &_tcph)
-                       memcpy(&_tcph, th, sizeof(_tcph));
-
-               if ((*pskb)->ip_summed != CHECKSUM_HW)
-                       _tcph.check = csum_fold(csum_partial((char *)diffs,
-                                                            sizeof(diffs),
-                                                            _tcph.check^0xFFFF));
-               memcpy((*pskb)->data + (*pskb)->nh.iph->ihl*4,
-                      &_tcph, sizeof(_tcph));
-               if ((*pskb)->ip_summed == CHECKSUM_HW)
-                       if (skb_checksum_help(*pskb, inward))
-                               return 0;
-               (*pskb)->nfcache |= NFC_ALTERED;
-       }
+       if ((*pskb)->ip_summed == CHECKSUM_HW &&
+           skb_checksum_help(*pskb, inward))
+               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_CWR)
+               tcph->cwr = einfo->proto.tcp.cwr;
+       diffs[1] = ((u_int16_t *)tcph)[6];
+       diffs[0] = diffs[0] ^ 0xFFFF;
+
+       if ((*pskb)->ip_summed != CHECKSUM_UNNECESSARY)
+               tcph->check = csum_fold(csum_partial((char *)diffs,
+                                                    sizeof(diffs),
+                                                    tcph->check^0xFFFF));
        return 1;
 }
 
@@ -117,12 +113,13 @@ target(struct sk_buff **pskb,
 
 static int
 checkentry(const char *tablename,
-          const struct ipt_entry *e,
+          const void *e_void,
            void *targinfo,
            unsigned int targinfosize,
            unsigned int hook_mask)
 {
        const struct ipt_ECN_info *einfo = (struct ipt_ECN_info *)targinfo;
+       const struct ipt_entry *e = e_void;
 
        if (targinfosize != IPT_ALIGN(sizeof(struct ipt_ECN_info))) {
                printk(KERN_WARNING "ECN: targinfosize %u != %Zu\n",
@@ -148,7 +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;