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authorChuck Lever <chuck.lever@oracle.com>2008-09-03 14:36:08 -0400
committerJ. Bruce Fields <bfields@citi.umich.edu>2008-09-29 18:13:39 -0400
commitede2fea099cf1dabe41e5b9563558bc7aee82248 (patch)
treeb007bc10b257a0615323c8dbc446aa3b9f0f1d67 /fs/lockd/host.c
parent781b61a6f4ff94cb8c14cf598b547f5d5c490969 (diff)
downloadlinux-ede2fea099cf1dabe41e5b9563558bc7aee82248.tar.bz2
lockd: Support AF_INET6 when hashing addresses in nlm_lookup_host
Adopt an approach similar to the RPC server's auth cache (from Aurelien Charbon and Brian Haley). Note nlm_lookup_host()'s existing IP address hash function has the same issue with correctness on little-endian systems as the original IPv4 auth cache hash function, so I've also updated it with a hash function similar to the new auth cache hash function. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Diffstat (limited to 'fs/lockd/host.c')
-rw-r--r--fs/lockd/host.c49
1 files changed, 43 insertions, 6 deletions
diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index dbf3fe620a0c..1f9d72a7a030 100644
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -22,7 +22,6 @@
#define NLMDBG_FACILITY NLMDBG_HOSTCACHE
#define NLM_HOST_NRHASH 32
-#define NLM_ADDRHASH(addr) (ntohl(addr) & (NLM_HOST_NRHASH-1))
#define NLM_HOST_REBIND (60 * HZ)
#define NLM_HOST_EXPIRE (300 * HZ)
#define NLM_HOST_COLLECT (120 * HZ)
@@ -40,6 +39,48 @@ static struct nsm_handle * nsm_find(const struct sockaddr_in *sin,
const char *hostname,
unsigned int hostname_len);
+/*
+ * Hash function must work well on big- and little-endian platforms
+ */
+static unsigned int __nlm_hash32(const __be32 n)
+{
+ unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
+ return hash ^ (hash >> 8);
+}
+
+static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
+{
+ const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
+ return __nlm_hash32(sin->sin_addr.s_addr);
+}
+
+static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
+{
+ const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
+ const struct in6_addr addr = sin6->sin6_addr;
+ return __nlm_hash32(addr.s6_addr32[0]) ^
+ __nlm_hash32(addr.s6_addr32[1]) ^
+ __nlm_hash32(addr.s6_addr32[2]) ^
+ __nlm_hash32(addr.s6_addr32[3]);
+}
+
+static unsigned int nlm_hash_address(const struct sockaddr *sap)
+{
+ unsigned int hash;
+
+ switch (sap->sa_family) {
+ case AF_INET:
+ hash = __nlm_hash_addr4(sap);
+ break;
+ case AF_INET6:
+ hash = __nlm_hash_addr6(sap);
+ break;
+ default:
+ hash = 0;
+ }
+ return hash & (NLM_HOST_NRHASH - 1);
+}
+
static void nlm_clear_port(struct sockaddr *sap)
{
switch (sap->sa_family) {
@@ -92,16 +133,12 @@ static struct nlm_host *nlm_lookup_host(int server,
struct hlist_node *pos;
struct nlm_host *host;
struct nsm_handle *nsm = NULL;
- int hash;
dprintk("lockd: nlm_lookup_host(proto=%d, vers=%u,"
" my role is %s, hostname=%.*s)\n",
proto, version, server ? "server" : "client",
hostname_len, hostname ? hostname : "<none>");
- hash = NLM_ADDRHASH(sin->sin_addr.s_addr);
-
- /* Lock hash table */
mutex_lock(&nlm_host_mutex);
if (time_after_eq(jiffies, next_gc))
@@ -114,7 +151,7 @@ static struct nlm_host *nlm_lookup_host(int server,
* different NLM rpc_clients into one single nlm_host object.
* This would allow us to have one nlm_host per address.
*/
- chain = &nlm_hosts[hash];
+ chain = &nlm_hosts[nlm_hash_address((struct sockaddr *)sin)];
hlist_for_each_entry(host, pos, chain, h_hash) {
if (!nlm_cmp_addr(nlm_addr(host), (struct sockaddr *)sin))
continue;