[INET]: Move the TCP hashtable functions/structs to inet_hashtables.[ch]

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/inet_common.h

@@ -8,6 +8,11 @@ extern struct proto_ops		inet_dgram_ops;
  *	INET4 prototypes used by INET6
  */
 
+struct msghdr;
+struct sock;
+struct sockaddr;
+struct socket;
+
 extern void			inet_remove_sock(struct sock *sk1);
 extern void			inet_put_sock(unsigned short num, 
 					      struct sock *sk);

include/net/inet_hashtables.h

@@ -14,8 +14,107 @@
 #ifndef _INET_HASHTABLES_H
 #define _INET_HASHTABLES_H
 
+#include <linux/ip.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
 #include <linux/types.h>
 
+/* This is for all connections with a full identity, no wildcards.
+ * New scheme, half the table is for TIME_WAIT, the other half is
+ * for the rest.  I'll experiment with dynamic table growth later.
+ */
+struct inet_ehash_bucket {
+	rwlock_t	  lock;
+	struct hlist_head chain;
+} __attribute__((__aligned__(8)));
+
+/* There are a few simple rules, which allow for local port reuse by
+ * an application.  In essence:
+ *
+ *	1) Sockets bound to different interfaces may share a local port.
+ *	   Failing that, goto test 2.
+ *	2) If all sockets have sk->sk_reuse set, and none of them are in
+ *	   TCP_LISTEN state, the port may be shared.
+ *	   Failing that, goto test 3.
+ *	3) If all sockets are bound to a specific inet_sk(sk)->rcv_saddr local
+ *	   address, and none of them are the same, the port may be
+ *	   shared.
+ *	   Failing this, the port cannot be shared.
+ *
+ * The interesting point, is test #2.  This is what an FTP server does
+ * all day.  To optimize this case we use a specific flag bit defined
+ * below.  As we add sockets to a bind bucket list, we perform a
+ * check of: (newsk->sk_reuse && (newsk->sk_state != TCP_LISTEN))
+ * As long as all sockets added to a bind bucket pass this test,
+ * the flag bit will be set.
+ * The resulting situation is that tcp_v[46]_verify_bind() can just check
+ * for this flag bit, if it is set and the socket trying to bind has
+ * sk->sk_reuse set, we don't even have to walk the owners list at all,
+ * we return that it is ok to bind this socket to the requested local port.
+ *
+ * Sounds like a lot of work, but it is worth it.  In a more naive
+ * implementation (ie. current FreeBSD etc.) the entire list of ports
+ * must be walked for each data port opened by an ftp server.  Needless
+ * to say, this does not scale at all.  With a couple thousand FTP
+ * users logged onto your box, isn't it nice to know that new data
+ * ports are created in O(1) time?  I thought so. ;-)	-DaveM
+ */
+struct inet_bind_bucket {
+	unsigned short		port;
+	signed short		fastreuse;
+	struct hlist_node	node;
+	struct hlist_head	owners;
+};
+
+#define inet_bind_bucket_for_each(tb, node, head) \
+	hlist_for_each_entry(tb, node, head, node)
+
+struct inet_bind_hashbucket {
+	spinlock_t		lock;
+	struct hlist_head	chain;
+};
+
+/* This is for listening sockets, thus all sockets which possess wildcards. */
+#define INET_LHTABLE_SIZE	32	/* Yes, really, this is all you need. */
+
+struct inet_hashinfo {
+	/* This is for sockets with full identity only.  Sockets here will
+	 * always be without wildcards and will have the following invariant:
+	 *
+	 *          TCP_ESTABLISHED <= sk->sk_state < TCP_CLOSE
+	 *
+	 * First half of the table is for sockets not in TIME_WAIT, second half
+	 * is for TIME_WAIT sockets only.
+	 */
+	struct inet_ehash_bucket	*ehash;
+
+	/* Ok, let's try this, I give up, we do need a local binding
+	 * TCP hash as well as the others for fast bind/connect.
+	 */
+	struct inet_bind_hashbucket	*bhash;
+
+	int				bhash_size;
+	int				ehash_size;
+
+	/* All sockets in TCP_LISTEN state will be in here.  This is the only
+	 * table where wildcard'd TCP sockets can exist.  Hash function here
+	 * is just local port number.
+	 */
+	struct hlist_head		listening_hash[INET_LHTABLE_SIZE];
+
+	/* All the above members are written once at bootup and
+	 * never written again _or_ are predominantly read-access.
+	 *
+	 * Now align to a new cache line as all the following members
+	 * are often dirty.
+	 */
+	rwlock_t			lhash_lock ____cacheline_aligned;
+	atomic_t			lhash_users;
+	wait_queue_head_t		lhash_wait;
+	spinlock_t			portalloc_lock;
+};
+
 static inline int inet_ehashfn(const __u32 laddr, const __u16 lport,
 			       const __u32 faddr, const __u16 fport,
 			       const int ehash_size)
@@ -37,4 +136,27 @@ static inline int inet_sk_ehashfn(const struct sock *sk, const int ehash_size)
 	return inet_ehashfn(laddr, lport, faddr, fport, ehash_size);
 }
 
+extern struct inet_bind_bucket *
+		    inet_bind_bucket_create(kmem_cache_t *cachep,
+					    struct inet_bind_hashbucket *head,
+					    const unsigned short snum);
+extern void inet_bind_bucket_destroy(kmem_cache_t *cachep,
+				     struct inet_bind_bucket *tb);
+
+static inline int inet_bhashfn(const __u16 lport, const int bhash_size)
+{
+	return lport & (bhash_size - 1);
+}
+
+/* These can have wildcards, don't try too hard. */
+static inline int inet_lhashfn(const unsigned short num)
+{
+	return num & (INET_LHTABLE_SIZE - 1);
+}
+
+static inline int inet_sk_listen_hashfn(const struct sock *sk)
+{
+	return inet_lhashfn(inet_sk(sk)->num);
+}
+
 #endif /* _INET_HASHTABLES_H */

include/net/tcp.h

@@ -30,6 +30,7 @@
 #include <linux/slab.h>
 #include <linux/cache.h>
 #include <linux/percpu.h>
+#include <net/inet_hashtables.h>
 #include <net/checksum.h>
 #include <net/request_sock.h>
 #include <net/sock.h>
@@ -40,101 +41,6 @@
 #endif
 #include <linux/seq_file.h>
 
-/* This is for all connections with a full identity, no wildcards.
- * New scheme, half the table is for TIME_WAIT, the other half is
- * for the rest.  I'll experiment with dynamic table growth later.
- */
-struct inet_ehash_bucket {
-	rwlock_t	  lock;
-	struct hlist_head chain;
-} __attribute__((__aligned__(8)));
-
-/* This is for listening sockets, thus all sockets which possess wildcards. */
-#define INET_LHTABLE_SIZE	32	/* Yes, really, this is all you need. */
-
-/* There are a few simple rules, which allow for local port reuse by
- * an application.  In essence:
- *
- *	1) Sockets bound to different interfaces may share a local port.
- *	   Failing that, goto test 2.
- *	2) If all sockets have sk->sk_reuse set, and none of them are in
- *	   TCP_LISTEN state, the port may be shared.
- *	   Failing that, goto test 3.
- *	3) If all sockets are bound to a specific inet_sk(sk)->rcv_saddr local
- *	   address, and none of them are the same, the port may be
- *	   shared.
- *	   Failing this, the port cannot be shared.
- *
- * The interesting point, is test #2.  This is what an FTP server does
- * all day.  To optimize this case we use a specific flag bit defined
- * below.  As we add sockets to a bind bucket list, we perform a
- * check of: (newsk->sk_reuse && (newsk->sk_state != TCP_LISTEN))
- * As long as all sockets added to a bind bucket pass this test,
- * the flag bit will be set.
- * The resulting situation is that tcp_v[46]_verify_bind() can just check
- * for this flag bit, if it is set and the socket trying to bind has
- * sk->sk_reuse set, we don't even have to walk the owners list at all,
- * we return that it is ok to bind this socket to the requested local port.
- *
- * Sounds like a lot of work, but it is worth it.  In a more naive
- * implementation (ie. current FreeBSD etc.) the entire list of ports
- * must be walked for each data port opened by an ftp server.  Needless
- * to say, this does not scale at all.  With a couple thousand FTP
- * users logged onto your box, isn't it nice to know that new data
- * ports are created in O(1) time?  I thought so. ;-)	-DaveM
- */
-struct inet_bind_bucket {
-	unsigned short		port;
-	signed short		fastreuse;
-	struct hlist_node	node;
-	struct hlist_head	owners;
-};
-
-#define inet_bind_bucket_for_each(tb, node, head) \
-	hlist_for_each_entry(tb, node, head, node)
-
-struct inet_bind_hashbucket {
-	spinlock_t		lock;
-	struct hlist_head	chain;
-};
-
-struct inet_hashinfo {
-	/* This is for sockets with full identity only.  Sockets here will
-	 * always be without wildcards and will have the following invariant:
-	 *
-	 *          TCP_ESTABLISHED <= sk->sk_state < TCP_CLOSE
-	 *
-	 * First half of the table is for sockets not in TIME_WAIT, second half
-	 * is for TIME_WAIT sockets only.
-	 */
-	struct inet_ehash_bucket	*ehash;
-
-	/* Ok, let's try this, I give up, we do need a local binding
-	 * TCP hash as well as the others for fast bind/connect.
-	 */
-	struct inet_bind_hashbucket	*bhash;
-
-	int				bhash_size;
-	int				ehash_size;
-
-	/* All sockets in TCP_LISTEN state will be in here.  This is the only
-	 * table where wildcard'd TCP sockets can exist.  Hash function here
-	 * is just local port number.
-	 */
-	struct hlist_head		listening_hash[INET_LHTABLE_SIZE];
-
-	/* All the above members are written once at bootup and
-	 * never written again _or_ are predominantly read-access.
-	 *
-	 * Now align to a new cache line as all the following members
-	 * are often dirty.
-	 */
-	rwlock_t			lhash_lock ____cacheline_aligned;
-	atomic_t			lhash_users;
-	wait_queue_head_t		lhash_wait;
-	spinlock_t			portalloc_lock;
-};
-
 extern struct inet_hashinfo	tcp_hashinfo;
 #define tcp_ehash		(tcp_hashinfo.ehash)
 #define tcp_bhash		(tcp_hashinfo.bhash)
@@ -147,19 +53,8 @@ extern struct inet_hashinfo	tcp_hashinfo;
 #define tcp_portalloc_lock	(tcp_hashinfo.portalloc_lock)
 
 extern kmem_cache_t *tcp_bucket_cachep;
-extern struct inet_bind_bucket *
-	    inet_bind_bucket_create(kmem_cache_t *cachep,
-				    struct inet_bind_hashbucket *head,
-				    const unsigned short snum);
-extern void inet_bind_bucket_destroy(kmem_cache_t *cachep,
-				     struct inet_bind_bucket *tb);
-extern int tcp_port_rover;
 
-/* These are AF independent. */
-static inline int inet_bhashfn(const __u16 lport, const int bhash_size)
-{
-	return lport & (bhash_size - 1);
-}
+extern int tcp_port_rover;
 
 extern void tcp_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
 			  unsigned short snum);
@@ -359,17 +254,6 @@ extern void tcp_tw_deschedule(struct tcp_tw_bucket *tw);
 	 ipv6_addr_equal(&inet6_sk(__sk)->rcv_saddr, (__daddr))	&& \
 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
 
-/* These can have wildcards, don't try too hard. */
-static inline int inet_lhashfn(const unsigned short num)
-{
-	return num & (INET_LHTABLE_SIZE - 1);
-}
-
-static inline int inet_sk_listen_hashfn(const struct sock *sk)
-{
-	return inet_lhashfn(inet_sk(sk)->num);
-}
-
 #define MAX_TCP_HEADER	(128 + MAX_HEADER)
 
 /* 

net/ipv4/Makefile

@@ -4,7 +4,7 @@
 
 obj-y     := route.o inetpeer.o protocol.o \
 	     ip_input.o ip_fragment.o ip_forward.o ip_options.o \
-	     ip_output.o ip_sockglue.o \
+	     ip_output.o ip_sockglue.o inet_hashtables.o \
 	     tcp.o tcp_input.o tcp_output.o tcp_timer.o tcp_ipv4.o \
 	     tcp_minisocks.o tcp_cong.o \
 	     datagram.o raw.o udp.o arp.o icmp.o devinet.o af_inet.o igmp.o \

net/ipv4/inet_hashtables.c

+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Generic INET transport hashtables
+ *
+ * Authors:	Lotsa people, from code originally in tcp
+ *
+ *	This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/slab.h>
+
+#include <net/inet_hashtables.h>
+
+/*
+ * Allocate and initialize a new local port bind bucket.
+ * The bindhash mutex for snum's hash chain must be held here.
+ */
+struct inet_bind_bucket *inet_bind_bucket_create(kmem_cache_t *cachep,
+						 struct inet_bind_hashbucket *head,
+						 const unsigned short snum)
+{
+	struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, SLAB_ATOMIC);
+
+	if (tb != NULL) {
+		tb->port      = snum;
+		tb->fastreuse = 0;
+		INIT_HLIST_HEAD(&tb->owners);
+		hlist_add_head(&tb->node, &head->chain);
+	}
+	return tb;
+}
+
+EXPORT_SYMBOL(inet_bind_bucket_create);
+
+/*
+ * Caller must hold hashbucket lock for this tb with local BH disabled
+ */
+void inet_bind_bucket_destroy(kmem_cache_t *cachep, struct inet_bind_bucket *tb)
+{
+	if (hlist_empty(&tb->owners)) {
+		__hlist_del(&tb->node);
+		kmem_cache_free(cachep, tb);
+	}
+}

net/ipv4/tcp_ipv4.c

@@ -104,32 +104,6 @@ struct inet_hashinfo __cacheline_aligned tcp_hashinfo = {
 int sysctl_local_port_range[2] = { 1024, 4999 };
 int tcp_port_rover = 1024 - 1;
 
-/* Allocate and initialize a new local port bind bucket.
- * The bindhash mutex for snum's hash chain must be held here.
- */
-struct inet_bind_bucket *inet_bind_bucket_create(kmem_cache_t *cachep,
-						 struct inet_bind_hashbucket *head,
-						 const unsigned short snum)
-{
-	struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, SLAB_ATOMIC);
-	if (tb) {
-		tb->port = snum;
-		tb->fastreuse = 0;
-		INIT_HLIST_HEAD(&tb->owners);
-		hlist_add_head(&tb->node, &head->chain);
-	}
-	return tb;
-}
-
-/* Caller must hold hashbucket lock for this tb with local BH disabled */
-void inet_bind_bucket_destroy(kmem_cache_t *cachep, struct inet_bind_bucket *tb)
-{
-	if (hlist_empty(&tb->owners)) {
-		__hlist_del(&tb->node);
-		kmem_cache_free(cachep, tb);
-	}
-}
-
 /* Caller must disable local BH processing. */
 static __inline__ void __tcp_inherit_port(struct sock *sk, struct sock *child)
 {