1 files changed, 24 insertions, 21 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index b8d49a0d99a0..aefd41ffadc2 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -159,37 +159,37 @@ int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	struct in6_addr *first_hop = &fl6->daddr;
 	struct dst_entry *dst = skb_dst(skb);
+	unsigned int head_room;
 	struct ipv6hdr *hdr;
 	u8  proto = fl6->flowi6_proto;
 	int seg_len = skb->len;
 	int hlimit = -1;
 	u32 mtu;
 
-	if (opt) {
-		unsigned int head_room;
+	head_room = sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
+	if (opt)
+		head_room += opt->opt_nflen + opt->opt_flen;
 
-		/* First: exthdrs may take lots of space (~8K for now)
-		   MAX_HEADER is not enough.
-		 */
-		head_room = opt->opt_nflen + opt->opt_flen;
-		seg_len += head_room;
-		head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
-
-		if (skb_headroom(skb) < head_room) {
-			struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
-			if (skb2 == NULL) {
-				IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
-					      IPSTATS_MIB_OUTDISCARDS);
-				kfree_skb(skb);
-				return -ENOBUFS;
-			}
-			if (skb->sk)
-				skb_set_owner_w(skb2, skb->sk);
-			consume_skb(skb);
-			skb = skb2;
+	if (unlikely(skb_headroom(skb) < head_room)) {
+		struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
+		if (!skb2) {
+			IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+				      IPSTATS_MIB_OUTDISCARDS);
+			kfree_skb(skb);
+			return -ENOBUFS;
 		}
+		if (skb->sk)
+			skb_set_owner_w(skb2, skb->sk);
+		consume_skb(skb);
+		skb = skb2;
+	}
+
+	if (opt) {
+		seg_len += opt->opt_nflen + opt->opt_flen;
+
 		if (opt->opt_flen)
 			ipv6_push_frag_opts(skb, opt, &proto);
+
 		if (opt->opt_nflen)
 			ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
 	}
@@ -546,12 +546,15 @@ static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
 static void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt)
 {
 	static u32 ip6_idents_hashrnd __read_mostly;
+	static u32 ip6_idents_hashrnd_extra __read_mostly;
 	u32 hash, id;
 
 	net_get_random_once(&ip6_idents_hashrnd, sizeof(ip6_idents_hashrnd));
+	net_get_random_once(&ip6_idents_hashrnd_extra, sizeof(ip6_idents_hashrnd_extra));
 
 	hash = __ipv6_addr_jhash(&rt->rt6i_dst.addr, ip6_idents_hashrnd);
 	hash = __ipv6_addr_jhash(&rt->rt6i_src.addr, hash);
+	hash = jhash_1word(hash, ip6_idents_hashrnd_extra);
 
 	id = ip_idents_reserve(hash, 1);
 	fhdr->identification = htonl(id);