From fb3cfe6e75b9d05c87265e85e67d7caf6e5b44a7 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 24 Jul 2014 16:50:30 +0200 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/ieee802154/reassembly.c | 12 ++++-------- net/ipv4/inet_fragment.c | 13 ++++++++++--- net/ipv4/ip_fragment.c | 2 +- net/ipv6/netfilter/nf_conntrack_reasm.c | 7 ++----- net/ipv6/reassembly.c | 8 ++------ 5 files changed, 19 insertions(+), 23 deletions(-) diff --git a/net/ieee802154/reassembly.c b/net/ieee802154/reassembly.c index a5588be1802..a707995fd4d 100644 --- a/net/ieee802154/reassembly.c +++ b/net/ieee802154/reassembly.c @@ -50,15 +50,11 @@ static unsigned int lowpan_hash_frag(__be16 tag, u16 d_size, const struct ieee802154_addr *saddr, const struct ieee802154_addr *daddr) { - u32 c; - net_get_random_once(&lowpan_frags.rnd, sizeof(lowpan_frags.rnd)); - c = jhash_3words(ieee802154_addr_hash(saddr), - ieee802154_addr_hash(daddr), - (__force u32)(tag + (d_size << 16)), - lowpan_frags.rnd); - - return c & (INETFRAGS_HASHSZ - 1); + return jhash_3words(ieee802154_addr_hash(saddr), + ieee802154_addr_hash(daddr), + (__force u32)(tag + (d_size << 16)), + lowpan_frags.rnd); } static unsigned int lowpan_hashfn(const struct inet_frag_queue *q) diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c index 3b01959bf4b..930d2387081 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 586e6aaf9e6..b769eb6c83c 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) diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index c2c3f2116bc..607e4a94ef4 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -147,12 +147,9 @@ static inline u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h) static unsigned int nf_hash_frag(__be32 id, const struct in6_addr *saddr, const struct in6_addr *daddr) { - u32 c; - net_get_random_once(&nf_frags.rnd, sizeof(nf_frags.rnd)); - c = jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr), - (__force u32)id, nf_frags.rnd); - return c & (INETFRAGS_HASHSZ - 1); + return jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr), + (__force u32)id, nf_frags.rnd); } diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index 0c6932cc08c..2b76549a101 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -85,13 +85,9 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, static unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr, const struct in6_addr *daddr) { - u32 c; - net_get_random_once(&ip6_frags.rnd, sizeof(ip6_frags.rnd)); - c = jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr), - (__force u32)id, ip6_frags.rnd); - - return c & (INETFRAGS_HASHSZ - 1); + return jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr), + (__force u32)id, ip6_frags.rnd); } static unsigned int ip6_hashfn(const struct inet_frag_queue *q) -- 2.41.0