linux/include/net/inet_timewait_sock.h
Eric Dumazet 3e5cbbb1fb tcp: remove volatile qualifier on tw_substate
Using a volatile qualifier for a specific struct field is unusual.

Use instead READ_ONCE()/WRITE_ONCE() where necessary.

tcp_timewait_state_process() can change tw_substate while other
threads are reading this field.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://patch.msgid.link/20240827015250.3509197-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-28 17:08:16 -07:00

125 lines
3.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* 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
*/
#ifndef _INET_TIMEWAIT_SOCK_
#define _INET_TIMEWAIT_SOCK_
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include <net/inet_sock.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <net/timewait_sock.h>
#include <linux/atomic.h>
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_reuseport __tw_common.skc_reuseport
#define tw_ipv6only __tw_common.skc_ipv6only
#define tw_bound_dev_if __tw_common.skc_bound_dev_if
#define tw_node __tw_common.skc_nulls_node
#define tw_bind_node __tw_common.skc_bind_node
#define tw_refcnt __tw_common.skc_refcnt
#define tw_hash __tw_common.skc_hash
#define tw_prot __tw_common.skc_prot
#define tw_net __tw_common.skc_net
#define tw_daddr __tw_common.skc_daddr
#define tw_v6_daddr __tw_common.skc_v6_daddr
#define tw_rcv_saddr __tw_common.skc_rcv_saddr
#define tw_v6_rcv_saddr __tw_common.skc_v6_rcv_saddr
#define tw_dport __tw_common.skc_dport
#define tw_num __tw_common.skc_num
#define tw_cookie __tw_common.skc_cookie
#define tw_dr __tw_common.skc_tw_dr
__u32 tw_mark;
unsigned char tw_substate;
unsigned char tw_rcv_wscale;
/* Socket demultiplex comparisons on incoming packets. */
/* these three are in inet_sock */
__be16 tw_sport;
/* And these are ours. */
unsigned int tw_transparent : 1,
tw_flowlabel : 20,
tw_usec_ts : 1,
tw_pad : 2, /* 2 bits hole */
tw_tos : 8;
u32 tw_txhash;
u32 tw_priority;
struct timer_list tw_timer;
struct inet_bind_bucket *tw_tb;
struct inet_bind2_bucket *tw_tb2;
};
#define tw_tclass tw_tos
static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
{
return (struct inet_timewait_sock *)sk;
}
void inet_twsk_free(struct inet_timewait_sock *tw);
void inet_twsk_put(struct inet_timewait_sock *tw);
void inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
struct inet_hashinfo *hashinfo);
struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
struct inet_timewait_death_row *dr,
const int state);
void inet_twsk_hashdance_schedule(struct inet_timewait_sock *tw,
struct sock *sk,
struct inet_hashinfo *hashinfo,
int timeo);
void __inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo,
bool rearm);
static inline void inet_twsk_reschedule(struct inet_timewait_sock *tw, int timeo)
{
__inet_twsk_schedule(tw, timeo, true);
}
void inet_twsk_deschedule_put(struct inet_timewait_sock *tw);
void inet_twsk_purge(struct inet_hashinfo *hashinfo);
static inline
struct net *twsk_net(const struct inet_timewait_sock *twsk)
{
return read_pnet(&twsk->tw_net);
}
static inline
void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net)
{
write_pnet(&twsk->tw_net, net);
}
#endif /* _INET_TIMEWAIT_SOCK_ */