neigh: Factor out ___neigh_lookup_noref
While looking at the mpls code I found myself writing yet another
version of neigh_lookup_noref. We currently have __ipv4_lookup_noref
and __ipv6_lookup_noref.
So to make my work a little easier and to make it a smidge easier to
verify/maintain the mpls code in the future I stopped and wrote
___neigh_lookup_noref. Then I rewote __ipv4_lookup_noref and
__ipv6_lookup_noref in terms of this new function. I tested my new
version by verifying that the same code is generated in
ip_finish_output2 and ip6_finish_output2 where these functions are
inlined.
To get to ___neigh_lookup_noref I added a new neighbour cache table
function key_eq. So that the static size of the key would be
available.
I also added __neigh_lookup_noref for people who want to to lookup
a neighbour table entry quickly but don't know which neibhgour table
they are going to look up.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 0f48ea3..fe3c6eac 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -397,25 +397,15 @@
struct net_device *dev)
{
struct neighbour *n;
- int key_len = tbl->key_len;
- u32 hash_val;
- struct neigh_hash_table *nht;
NEIGH_CACHE_STAT_INC(tbl, lookups);
rcu_read_lock_bh();
- nht = rcu_dereference_bh(tbl->nht);
- hash_val = tbl->hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
-
- for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
- n != NULL;
- n = rcu_dereference_bh(n->next)) {
- if (dev == n->dev && !memcmp(n->primary_key, pkey, key_len)) {
- if (!atomic_inc_not_zero(&n->refcnt))
- n = NULL;
- NEIGH_CACHE_STAT_INC(tbl, hits);
- break;
- }
+ n = __neigh_lookup_noref(tbl, pkey, dev);
+ if (n) {
+ if (!atomic_inc_not_zero(&n->refcnt))
+ n = NULL;
+ NEIGH_CACHE_STAT_INC(tbl, hits);
}
rcu_read_unlock_bh();
diff --git a/net/decnet/dn_neigh.c b/net/decnet/dn_neigh.c
index f123c6c..ee7d1ce 100644
--- a/net/decnet/dn_neigh.c
+++ b/net/decnet/dn_neigh.c
@@ -93,12 +93,18 @@
return jhash_2words(*(__u16 *)pkey, 0, hash_rnd[0]);
}
+static bool dn_key_eq(const struct neighbour *neigh, const void *pkey)
+{
+ return neigh_key_eq16(neigh, pkey);
+}
+
struct neigh_table dn_neigh_table = {
.family = PF_DECnet,
.entry_size = NEIGH_ENTRY_SIZE(sizeof(struct dn_neigh)),
.key_len = sizeof(__le16),
.protocol = cpu_to_be16(ETH_P_DNA_RT),
.hash = dn_neigh_hash,
+ .key_eq = dn_key_eq,
.constructor = dn_neigh_construct,
.id = "dn_neigh_cache",
.parms ={
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 6b8aad6a..5f5c674 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -122,6 +122,7 @@
* Interface to generic neighbour cache.
*/
static u32 arp_hash(const void *pkey, const struct net_device *dev, __u32 *hash_rnd);
+static bool arp_key_eq(const struct neighbour *n, const void *pkey);
static int arp_constructor(struct neighbour *neigh);
static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb);
static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb);
@@ -154,6 +155,7 @@
.key_len = 4,
.protocol = cpu_to_be16(ETH_P_IP),
.hash = arp_hash,
+ .key_eq = arp_key_eq,
.constructor = arp_constructor,
.proxy_redo = parp_redo,
.id = "arp_cache",
@@ -209,7 +211,12 @@
const struct net_device *dev,
__u32 *hash_rnd)
{
- return arp_hashfn(*(u32 *)pkey, dev, *hash_rnd);
+ return arp_hashfn(pkey, dev, hash_rnd);
+}
+
+static bool arp_key_eq(const struct neighbour *neigh, const void *pkey)
+{
+ return neigh_key_eq32(neigh, pkey);
}
static int arp_constructor(struct neighbour *neigh)
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index e363bbc..247ad7c 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -84,6 +84,7 @@
static u32 ndisc_hash(const void *pkey,
const struct net_device *dev,
__u32 *hash_rnd);
+static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
static int ndisc_constructor(struct neighbour *neigh);
static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
@@ -119,6 +120,7 @@
.key_len = sizeof(struct in6_addr),
.protocol = cpu_to_be16(ETH_P_IPV6),
.hash = ndisc_hash,
+ .key_eq = ndisc_key_eq,
.constructor = ndisc_constructor,
.pconstructor = pndisc_constructor,
.pdestructor = pndisc_destructor,
@@ -295,6 +297,11 @@
return ndisc_hashfn(pkey, dev, hash_rnd);
}
+static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
+{
+ return neigh_key_eq128(n, pkey);
+}
+
static int ndisc_constructor(struct neighbour *neigh)
{
struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;