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

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Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Arnaldo Carvalho de Melo 2005-08-09 20:00:51 -07:00 committed by David S. Miller
parent 0f7ff9274e
commit 77d8bf9c62
6 changed files with 181 additions and 145 deletions
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5
include/net/inet_common.h
View file

@ -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);

122
include/net/inet_hashtables.h
View file

@ -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 */

120
include/net/tcp.h
View file

@ -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)
/*

2
net/ipv4/Makefile
View file

@ -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 \

51
net/ipv4/inet_hashtables.c Normal file
View file

@ -0,0 +1,51 @@
/*
* 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);
}
}

26
net/ipv4/tcp_ipv4.c
View file

@ -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)
{