inet: switch IP ID generator to siphash

[GitHub/MotorolaMobilityLLC/kernel-slsi.git] / net / ipv4 / route.c

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index a1bf87711bfaa077584dd98c30eed88f45d24417..699b63f04d1eaf8fdb4d5eeecf8932dd45e02acf 100644 (file)
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -517,15 +517,17 @@ EXPORT_SYMBOL(ip_idents_reserve);
 
 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
 {
-       static u32 ip_idents_hashrnd __read_mostly;
        u32 hash, id;
 
-       net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
+       /* Note the following code is not safe, but this is okay. */
+       if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key)))
+               get_random_bytes(&net->ipv4.ip_id_key,
+                                sizeof(net->ipv4.ip_id_key));
 
-       hash = jhash_3words((__force u32)iph->daddr,
+       hash = siphash_3u32((__force u32)iph->daddr,
                            (__force u32)iph->saddr,
-                           iph->protocol ^ net_hash_mix(net),
-                           ip_idents_hashrnd);
+                           iph->protocol,
+                           &net->ipv4.ip_id_key);
        id = ip_idents_reserve(hash, segs);
        iph->id = htons(id);
 }