[PATCH 3.16 145/157] Revert "inet: update the IP ID generation algorithm to higher standards."

[Ben Hutchings]

3.16.72-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Ben Hutchings <ben@xxxxxxxxxxxxxxx>

This reverts commit 8b197d3ce585d6777197e0633d71e5af7d98cb35, which
was a stable-specific improvement to IP ID selection.  I will apply
the upstream changes instead.

Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -487,15 +487,13 @@ EXPORT_SYMBOL(ip_idents_reserve);
 void __ip_select_ident(struct iphdr *iph, int segs)
 {
 	static u32 ip_idents_hashrnd __read_mostly;
-	static u32 ip_idents_hashrnd_extra __read_mostly;
 	u32 hash, id;
 
 	net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
-	net_get_random_once(&ip_idents_hashrnd_extra, sizeof(ip_idents_hashrnd_extra));
 
 	hash = jhash_3words((__force u32)iph->daddr,
 			    (__force u32)iph->saddr,
-			    iph->protocol ^ ip_idents_hashrnd_extra,
+			    iph->protocol,
 			    ip_idents_hashrnd);
 	id = ip_idents_reserve(hash, segs);
 	iph->id = htons(id);
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -541,15 +541,12 @@ static void ip6_copy_metadata(struct sk_
 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);