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[INET]: Generalise tcp_tw_bucket, aka TIME_WAIT sockets

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This paves the way to generalise the rest of the sock ID lookup
routines and saves some bytes in TCPv4 TIME_WAIT sockets on distro
kernels (where IPv6 is always built as a module):

[root@qemu ~]# grep tw_sock /proc/slabinfo
tw_sock_TCPv6  0  0  128  31  1
tw_sock_TCP    0  0   96  41  1
[root@qemu ~]#

Now if a protocol wants to use the TIME_WAIT generic infrastructure it
only has to set the sk_prot->twsk_obj_size field with the size of its
inet_timewait_sock derived sock and proto_register will create
sk_prot->twsk_slab, for now its only for INET sockets, but we can
introduce timewait_sock later if some non INET transport protocolo
wants to use this stuff.

Next changesets will take advantage of this new infrastructure to
generalise even more TCP code.

[acme@toy net-2.6.14]$ grep built-in /tmp/before.size /tmp/after.size
/tmp/before.size: 188646   11764    5068  205478   322a6 net/ipv4/built-in.o
/tmp/after.size:  188144   11764    5068  204976   320b0 net/ipv4/built-in.o
[acme@toy net-2.6.14]$

Tested with both IPv4 & IPv6 (::1 (localhost) & ::ffff:172.20.0.1
(qemu host)).

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 20:09:30 -07:00
committed by David S. Miller
parent 33b6223190
commit 8feaf0c0a5
13 changed files with 484 additions and 391 deletions
Download Patch File Download Diff File Expand all files Collapse all files

142
include/net/inet_timewait_sock.h Normal file
View File

@ -0,0 +1,142 @@
/*
* 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.
*
* Definitions for a generic INET TIMEWAIT sock
*
* From code originally in net/tcp.h
*
* 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.
*/
#ifndef _INET_TIMEWAIT_SOCK_
#define _INET_TIMEWAIT_SOCK_
#include <linux/config.h>
#include <linux/list.h>
#include <linux/types.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <asm/atomic.h>
#if (BITS_PER_LONG == 64)
#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 8
#else
#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 4
#endif
struct inet_bind_bucket;
/*
* This is a TIME_WAIT sock. It works around the memory consumption
* problems of sockets in such a state on heavily loaded servers, but
* without violating the protocol specification.
*/
struct inet_timewait_sock {
/*
* Now struct sock also uses sock_common, so please just
* don't add nothing before this first member (__tw_common) --acme
*/
struct sock_common __tw_common;
#define tw_family __tw_common.skc_family
#define tw_state __tw_common.skc_state
#define tw_reuse __tw_common.skc_reuse
#define tw_bound_dev_if __tw_common.skc_bound_dev_if
#define tw_node __tw_common.skc_node
#define tw_bind_node __tw_common.skc_bind_node
#define tw_refcnt __tw_common.skc_refcnt
#define tw_prot __tw_common.skc_prot
volatile unsigned char tw_substate;
/* 3 bits hole, try to pack */
unsigned char tw_rcv_wscale;
/* Socket demultiplex comparisons on incoming packets. */
/* these five are in inet_sock */
__u16 tw_sport;
__u32 tw_daddr __attribute__((aligned(INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES)));
__u32 tw_rcv_saddr;
__u16 tw_dport;
__u16 tw_num;
/* And these are ours. */
__u8 tw_ipv6only:1;
/* 31 bits hole, try to pack */
int tw_hashent;
int tw_timeout;
unsigned long tw_ttd;
struct inet_bind_bucket *tw_tb;
struct hlist_node tw_death_node;
};
static inline void inet_twsk_add_node(struct inet_timewait_sock *tw,
struct hlist_head *list)
{
hlist_add_head(&tw->tw_node, list);
}
static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
struct hlist_head *list)
{
hlist_add_head(&tw->tw_bind_node, list);
}
static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw)
{
return tw->tw_death_node.pprev != NULL;
}
static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw)
{
tw->tw_death_node.pprev = NULL;
}
static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
{
__hlist_del(&tw->tw_death_node);
inet_twsk_dead_node_init(tw);
}
static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
{
if (inet_twsk_dead_hashed(tw)) {
__inet_twsk_del_dead_node(tw);
return 1;
}
return 0;
}
#define inet_twsk_for_each(tw, node, head) \
hlist_for_each_entry(tw, node, head, tw_node)
#define inet_twsk_for_each_inmate(tw, node, jail) \
hlist_for_each_entry(tw, node, jail, tw_death_node)
#define inet_twsk_for_each_inmate_safe(tw, node, safe, jail) \
hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node)
static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
{
return (struct inet_timewait_sock *)sk;
}
static inline u32 inet_rcv_saddr(const struct sock *sk)
{
return likely(sk->sk_state != TCP_TIME_WAIT) ?
inet_sk(sk)->rcv_saddr : inet_twsk(sk)->tw_rcv_saddr;
}
static inline void inet_twsk_put(struct inet_timewait_sock *tw)
{
if (atomic_dec_and_test(&tw->tw_refcnt)) {
#ifdef SOCK_REFCNT_DEBUG
printk(KERN_DEBUG "%s timewait_sock %p released\n",
tw->tw_prot->name, tw);
#endif
kmem_cache_free(tw->tw_prot->twsk_slab, tw);
}
}
#endif /* _INET_TIMEWAIT_SOCK_ */