net: Remove unused skb_shared_info member

ip6_frag_id was only used by UFO, which has been removed.
ipv6_proxy_select_ident() only existed to set ip6_frag_id and has no
in-tree callers.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/skbuff.h

@@ -500,7 +500,6 @@ struct skb_shared_info {
 	struct skb_shared_hwtstamps hwtstamps;
 	unsigned int	gso_type;
 	u32		tskey;
-	__be32          ip6_frag_id;
 
 	/*
 	 * Warning : all fields before dataref are cleared in __alloc_skb()

include/net/ipv6.h

@@ -767,7 +767,6 @@ static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_add
 __be32 ipv6_select_ident(struct net *net,
 			 const struct in6_addr *daddr,
 			 const struct in6_addr *saddr);
-void ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
 
 int ip6_dst_hoplimit(struct dst_entry *dst);
 

net/ipv6/output_core.c

@@ -31,37 +31,6 @@ static u32 __ipv6_select_ident(struct net *net, u32 hashrnd,
 	return id;
 }
 
-/* This function exists only for tap drivers that must support broken
- * clients requesting UFO without specifying an IPv6 fragment ID.
- *
- * This is similar to ipv6_select_ident() but we use an independent hash
- * seed to limit information leakage.
- *
- * The network header must be set before calling this.
- */
-void ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb)
-{
-	static u32 ip6_proxy_idents_hashrnd __read_mostly;
-	struct in6_addr buf[2];
-	struct in6_addr *addrs;
-	u32 id;
-
-	addrs = skb_header_pointer(skb,
-				   skb_network_offset(skb) +
-				   offsetof(struct ipv6hdr, saddr),
-				   sizeof(buf), buf);
-	if (!addrs)
-		return;
-
-	net_get_random_once(&ip6_proxy_idents_hashrnd,
-			    sizeof(ip6_proxy_idents_hashrnd));
-
-	id = __ipv6_select_ident(net, ip6_proxy_idents_hashrnd,
-				 &addrs[1], &addrs[0]);
-	skb_shinfo(skb)->ip6_frag_id = htonl(id);
-}
-EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
-
 __be32 ipv6_select_ident(struct net *net,
 			 const struct in6_addr *daddr,
 			 const struct in6_addr *saddr)