linux/net/ipv4/inet_timewait_sock.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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 TIME_WAIT sockets functions
 *
 *		From code orinally in TCP
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <net/inet_hashtables.h>
#include <net/inet_timewait_sock.h>
#include <net/ip.h>


/**
 *	inet_twsk_bind_unhash - unhash a timewait socket from bind hash
 *	@tw: timewait socket
 *	@hashinfo: hashinfo pointer
 *
 *	unhash a timewait socket from bind hash, if hashed.
 *	bind hash lock must be held by caller.
 *	Returns 1 if caller should call inet_twsk_put() after lock release.
 */
void inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
			  struct inet_hashinfo *hashinfo)
{ … }

/* Must be called with locally disabled BHs. */
static void inet_twsk_kill(struct inet_timewait_sock *tw)
{ … }

void inet_twsk_free(struct inet_timewait_sock *tw)
{ … }

void inet_twsk_put(struct inet_timewait_sock *tw)
{ … }
EXPORT_SYMBOL_GPL(…);

static void inet_twsk_add_node_rcu(struct inet_timewait_sock *tw,
				   struct hlist_nulls_head *list)
{ … }

static void inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo)
{ … }

/*
 * Enter the time wait state.
 * Essentially we whip up a timewait bucket, copy the relevant info into it
 * from the SK, and mess with hash chains and list linkage.
 *
 * The caller must not access @tw anymore after this function returns.
 */
void inet_twsk_hashdance_schedule(struct inet_timewait_sock *tw,
				  struct sock *sk,
				  struct inet_hashinfo *hashinfo,
				  int timeo)
{ … }
EXPORT_SYMBOL_GPL(…);

static void tw_timer_handler(struct timer_list *t)
{ … }

struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
					   struct inet_timewait_death_row *dr,
					   const int state)
{ … }
EXPORT_SYMBOL_GPL(…);

/* These are always called from BH context.  See callers in
 * tcp_input.c to verify this.
 */

/* This is for handling early-kills of TIME_WAIT sockets.
 * Warning : consume reference.
 * Caller should not access tw anymore.
 */
void inet_twsk_deschedule_put(struct inet_timewait_sock *tw)
{ … }
EXPORT_SYMBOL(…);

void __inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo, bool rearm)
{ … }
EXPORT_SYMBOL_GPL(…);

/* Remove all non full sockets (TIME_WAIT and NEW_SYN_RECV) for dead netns */
void inet_twsk_purge(struct inet_hashinfo *hashinfo)
{ … }
EXPORT_SYMBOL_GPL(…);