| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Tue, 03 Mar 2015 17:10:44 -0600
From: ebiederm@...ssion.com (Eric W. Biederman)
To: David Miller <davem@...emloft.net>
Cc: netdev@...r.kernel.org
Subject: [PATCH net-next 1/2] 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@...ssion.com>
---
include/net/arp.h | 19 ++++--------------
include/net/ndisc.h | 19 +-----------------
include/net/neighbour.h | 52 +++++++++++++++++++++++++++++++++++++++++++++++++
net/core/neighbour.c | 20 +++++--------------
net/decnet/dn_neigh.c | 6 ++++++
net/ipv4/arp.c | 9 ++++++++-
net/ipv6/ndisc.c | 7 +++++++
7 files changed, 83 insertions(+), 49 deletions(-)
diff --git a/include/net/arp.h b/include/net/arp.h
index 21ee1860abbc..5e0f891d476c 100644
--- a/include/net/arp.h
+++ b/include/net/arp.h
@@ -9,28 +9,17 @@
extern struct neigh_table arp_tbl;
-static inline u32 arp_hashfn(u32 key, const struct net_device *dev, u32 hash_rnd)
+static inline u32 arp_hashfn(const void *pkey, const struct net_device *dev, u32 *hash_rnd)
{
+ u32 key = *(const u32 *)pkey;
u32 val = key ^ hash32_ptr(dev);
- return val * hash_rnd;
+ return val * hash_rnd[0];
}
static inline struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key)
{
- struct neigh_hash_table *nht = rcu_dereference_bh(arp_tbl.nht);
- struct neighbour *n;
- u32 hash_val;
-
- hash_val = arp_hashfn(key, dev, nht->hash_rnd[0]) >> (32 - nht->hash_shift);
- for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
- n != NULL;
- n = rcu_dereference_bh(n->next)) {
- if (n->dev == dev && *(u32 *)n->primary_key == key)
- return n;
- }
-
- return NULL;
+ return ___neigh_lookup_noref(&arp_tbl, neigh_key_eq32, arp_hashfn, &key, dev);
}
static inline struct neighbour *__ipv4_neigh_lookup(struct net_device *dev, u32 key)
diff --git a/include/net/ndisc.h b/include/net/ndisc.h
index 6bbda34d5e59..b3a7751251b4 100644
--- a/include/net/ndisc.h
+++ b/include/net/ndisc.h
@@ -156,24 +156,7 @@ static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, _
static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey)
{
- struct neigh_hash_table *nht;
- const u32 *p32 = pkey;
- struct neighbour *n;
- u32 hash_val;
-
- nht = rcu_dereference_bh(nd_tbl.nht);
- hash_val = ndisc_hashfn(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)) {
- u32 *n32 = (u32 *) n->primary_key;
- if (n->dev == dev &&
- ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) |
- (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0)
- return n;
- }
-
- return NULL;
+ return ___neigh_lookup_noref(&nd_tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev);
}
static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey)
diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 9f912e4d4232..14e3f017966b 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -197,6 +197,7 @@ struct neigh_table {
__u32 (*hash)(const void *pkey,
const struct net_device *dev,
__u32 *hash_rnd);
+ bool (*key_eq)(const struct neighbour *, const void *pkey);
int (*constructor)(struct neighbour *);
int (*pconstructor)(struct pneigh_entry *);
void (*pdestructor)(struct pneigh_entry *);
@@ -247,6 +248,57 @@ static inline void *neighbour_priv(const struct neighbour *n)
#define NEIGH_UPDATE_F_ISROUTER 0x40000000
#define NEIGH_UPDATE_F_ADMIN 0x80000000
+
+static inline bool neigh_key_eq16(const struct neighbour *n, const void *pkey)
+{
+ return *(const u16 *)n->primary_key == *(const u16 *)pkey;
+}
+
+static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey)
+{
+ return *(const u32 *)n->primary_key == *(const u32 *)pkey;
+}
+
+static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey)
+{
+ const u32 *n32 = (const u32 *)n->primary_key;
+ const u32 *p32 = pkey;
+
+ return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) |
+ (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0;
+}
+
+static inline struct neighbour *___neigh_lookup_noref(
+ struct neigh_table *tbl,
+ bool (*key_eq)(const struct neighbour *n, const void *pkey),
+ __u32 (*hash)(const void *pkey,
+ const struct net_device *dev,
+ __u32 *hash_rnd),
+ const void *pkey,
+ struct net_device *dev)
+{
+ struct neigh_hash_table *nht = rcu_dereference_bh(tbl->nht);
+ struct neighbour *n;
+ u32 hash_val;
+
+ hash_val = 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 (n->dev == dev && key_eq(n, pkey))
+ return n;
+ }
+
+ return NULL;
+}
+
+static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl,
+ const void *pkey,
+ struct net_device *dev)
+{
+ return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev);
+}
+
void neigh_table_init(int index, struct neigh_table *tbl);
int neigh_table_clear(int index, struct neigh_table *tbl);
struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 0f48ea3affed..fe3c6eac5805 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -397,25 +397,15 @@ struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,
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 f123c6c6748c..ee7d1cef0027 100644
--- a/net/decnet/dn_neigh.c
+++ b/net/decnet/dn_neigh.c
@@ -93,12 +93,18 @@ static u32 dn_neigh_hash(const void *pkey,
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 6b8aad6a0d7d..5f5c674e130a 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 @@ struct neigh_table arp_tbl = {
.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 @@ static u32 arp_hash(const void *pkey,
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 e363bbc2420d..247ad7c298f7 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -84,6 +84,7 @@ do { \
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 @@ struct neigh_table nd_tbl = {
.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 @@ static u32 ndisc_hash(const void *pkey,
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;
--
2.2.1
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists