[IPV6]: Need to use pskb_trim_rcsum().

Fix pskb_trim usage in ipv6. Only the udp one is really
a bug, other places are just doing equivalent code.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/exthdrs.c

@@ -459,11 +459,10 @@ static int ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
 		IP6_INC_STATS_BH(IPSTATS_MIB_INTRUNCATEDPKTS);
 		goto drop;
 	}
-	if (pkt_len + sizeof(struct ipv6hdr) < skb->len) {
-		__pskb_trim(skb, pkt_len + sizeof(struct ipv6hdr));
-		if (skb->ip_summed == CHECKSUM_HW)
-			skb->ip_summed = CHECKSUM_NONE;
-	}
+
+	if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
+		goto drop;
+
 	return 1;
 
 drop:

net/ipv6/reassembly.c

@@ -479,12 +479,9 @@ static void ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
 	/* Point into the IP datagram 'data' part. */
 	if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
 		goto err;
-	if (end-offset < skb->len) {
-		if (pskb_trim(skb, end - offset))
-			goto err;
-		if (skb->ip_summed != CHECKSUM_UNNECESSARY)
-			skb->ip_summed = CHECKSUM_NONE;
-	}
+	
+	if (pskb_trim_rcsum(skb, end - offset))
+		goto err;
 
 	/* Find out which fragments are in front and at the back of us
 	 * in the chain of fragments so far.  We must know where to put

net/ipv6/udp.c

@@ -483,7 +483,7 @@ static int udpv6_rcv(struct sk_buff **pskb, unsigned int *nhoffp)
 	}
 
 	if (ulen < skb->len) {
-		if (__pskb_trim(skb, ulen))
+		if (pskb_trim_rcsum(skb, ulen))
 			goto discard;
 		saddr = &skb->nh.ipv6h->saddr;
 		daddr = &skb->nh.ipv6h->daddr;