inet: frag: remove hash size assumptions from callers

hide actual hash size from individual users: The _find
function will now fold the given hash value into the required range.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 11 insertions, 4 deletions

diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index 3b01959bf4bb..930d23870811 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -46,6 +46,12 @@ const u8 ip_frag_ecn_table[16] = {
 };
 EXPORT_SYMBOL(ip_frag_ecn_table);
 
+static unsigned int
+inet_frag_hashfn(const struct inet_frags *f, const struct inet_frag_queue *q)
+{
+        return f->hashfn(q) & (INETFRAGS_HASHSZ - 1);
+}
+
 static void inet_frag_secret_rebuild(unsigned long dummy)
 {
         struct inet_frags *f = (struct inet_frags *)dummy;
@@ -63,7 +69,7 @@ static void inet_frag_secret_rebuild(unsigned long dummy)
 
                 hb = &f->hash[i];
                 hlist_for_each_entry_safe(q, n, &hb->chain, list) {
-                        unsigned int hval = f->hashfn(q);
+                        unsigned int hval = inet_frag_hashfn(f, q);
 
                         if (hval != i) {
                                 struct inet_frag_bucket *hb_dest;
@@ -133,7 +139,7 @@ static inline void fq_unlink(struct inet_frag_queue *fq, struct inet_frags *f)
         unsigned int hash;
 
         read_lock(&f->lock);
-        hash = f->hashfn(fq);
+        hash = inet_frag_hashfn(f, fq);
         hb = &f->hash[hash];
 
         spin_lock(&hb->chain_lock);
@@ -252,7 +258,7 @@ static struct inet_frag_queue *inet_frag_intern(struct netns_frags *nf,
          * the rnd seed, so we need to re-calculate the hash
          * chain. Fortunatelly the qp_in can be used to get one.
          */
-        hash = f->hashfn(qp_in);
+        hash = inet_frag_hashfn(f, qp_in);
         hb = &f->hash[hash];
         spin_lock(&hb->chain_lock);
 
@@ -326,6 +332,7 @@ struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
         struct inet_frag_queue *q;
         int depth = 0;
 
+        hash &= (INETFRAGS_HASHSZ - 1);
         hb = &f->hash[hash];
 
         spin_lock(&hb->chain_lock);
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 586e6aaf9e6e..b769eb6c83c0 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -109,7 +109,7 @@ static unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot)
         net_get_random_once(&ip4_frags.rnd, sizeof(ip4_frags.rnd));
         return jhash_3words((__force u32)id << 16 | prot,
                             (__force u32)saddr, (__force u32)daddr,
-                            ip4_frags.rnd) & (INETFRAGS_HASHSZ - 1);
+                            ip4_frags.rnd);
 }
 
 static unsigned int ip4_hashfn(const struct inet_frag_queue *q)