X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;ds=sidebyside;f=net%2Fipv4%2Fnetfilter%2Fipt_ECN.c;h=120109cd294db678e9e47014075d9e69fe8cc1ae;hb=c7b5ebbddf7bcd3651947760f423e3783bbe6573;hp=8ca402564f5e0b662b76ce708a1f31f25d572c29;hpb=a2c21200f1c81b08cb55e417b68150bba439b646;p=linux-2.6.git

diff --git a/net/ipv4/netfilter/ipt_ECN.c b/net/ipv4/netfilter/ipt_ECN.c
index 8ca402564..120109cd2 100644
--- a/net/ipv4/netfilter/ipt_ECN.c
+++ b/net/ipv4/netfilter/ipt_ECN.c
@@ -52,34 +52,39 @@ 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;
+	struct tcphdr _tcph, *th;
 	u_int16_t diffs[2];
 
 	/* Not enought header? */
-	if (skb_copy_bits(*pskb, (*pskb)->nh.iph->ihl*4, &tcph, sizeof(tcph))
-	    < 0)
+	th = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl*4,
+				sizeof(_tcph), &_tcph);
+	if (th == NULL)
 		return 0;
 
-	diffs[0] = ((u_int16_t *)&tcph)[6];
+	diffs[0] = ((u_int16_t *)th)[6];
 	if (einfo->operation & IPT_ECN_OP_SET_ECE)
-		tcph.ece = einfo->proto.tcp.ece;
+		th->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];
+		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)))
+					  (*pskb)->nh.iph->ihl*4+sizeof(_tcph)))
 			return 0;
+
+		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));
+			_tcph.check = csum_fold(csum_partial((char *)diffs,
+							     sizeof(diffs),
+							     _tcph.check^0xFFFF));
 		memcpy((*pskb)->data + (*pskb)->nh.iph->ihl*4,
-		       &tcph, sizeof(tcph));
+		       &_tcph, sizeof(_tcph));
 		if ((*pskb)->ip_summed == CHECKSUM_HW)
 			if (skb_checksum_help(pskb, inward))
 				return 0;