path: root/include/net/sock.h

/*
 * 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 the AF_INET socket handler.
 *
 * Version:	@(#)sock.h	1.0.4	05/13/93
 *
 * Authors:	Ross Biro, <bir7@leland.Stanford.Edu>
 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *		Corey Minyard <wf-rch!minyard@relay.EU.net>
 *		Florian La Roche <flla@stud.uni-sb.de>
 *
 * Fixes:
 *		Alan Cox	:	Volatiles in skbuff pointers. See
 *					skbuff comments. May be overdone,
 *					better to prove they can be removed
 *					than the reverse.
 *		Alan Cox	:	Added a zapped field for tcp to note
 *					a socket is reset and must stay shut up
 *		Alan Cox	:	New fields for options
 *	Pauline Middelink	:	identd support
 *		Alan Cox	:	Eliminate low level recv/recvfrom
 *		David S. Miller	:	New socket lookup architecture.
 *              Steve Whitehouse:       Default routines for sock_ops
 *              Arnaldo C. Melo :	removed net_pinfo, tp_pinfo and made
 *              			protinfo be just a void pointer, as the
 *              			protocol specific parts were moved to
 *              			respective headers and ipv4/v6, etc now
 *              			use private slabcaches for its socks
 *              Pedro Hortas	:	New flags field for socket options
 *
 *
 *		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 _SOCK_H
#define _SOCK_H

#include <linux/config.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/cache.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>	/* struct sk_buff */
#include <linux/security.h>

#include <linux/filter.h>

#include <asm/atomic.h>
#include <net/dst.h>
#include <net/checksum.h>

/*
 * This structure really needs to be cleaned up.
 * Most of it is for TCP, and not used by any of
 * the other protocols.
 */

/* Define this to get the SOCK_DBG debugging facility. */
#define SOCK_DEBUGGING
#ifdef SOCK_DEBUGGING
#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
					printk(KERN_DEBUG msg); } while (0)
#else
#define SOCK_DEBUG(sk, msg...) do { } while (0)
#endif

/* This is the per-socket lock.  The spinlock provides a synchronization
 * between user contexts and software interrupt processing, whereas the
 * mini-semaphore synchronizes multiple users amongst themselves.
 */
struct sock_iocb;
typedef struct {
	spinlock_t		slock;
	struct sock_iocb	*owner;
	wait_queue_head_t	wq;
} socket_lock_t;

#define sock_lock_init(__sk) \
do {	spin_lock_init(&((__sk)->sk_lock.slock)); \
	(__sk)->sk_lock.owner = NULL; \
	init_waitqueue_head(&((__sk)->sk_lock.wq)); \
} while(0)

struct sock;

/**
  *	struct sock_common - minimal network layer representation of sockets
  *	@skc_family - network address family
  *	@skc_state - Connection state
  *	@skc_reuse - %SO_REUSEADDR setting
  *	@skc_bound_dev_if - bound device index if != 0
  *	@skc_node - main hash linkage for various protocol lookup tables
  *	@skc_bind_node - bind hash linkage for various protocol lookup tables
  *	@skc_refcnt - reference count
  *
  *	This is the minimal network layer representation of sockets, the header
  *	for struct sock and struct tcp_tw_bucket.
  */
struct sock_common {
	unsigned short		skc_family;
	volatile unsigned char	skc_state;
	unsigned char		skc_reuse;
	int			skc_bound_dev_if;
	struct hlist_node	skc_node;
	struct hlist_node	skc_bind_node;
	atomic_t		skc_refcnt;
};

/**
  *	struct sock - network layer representation of sockets
  *	@__sk_common - shared layout with tcp_tw_bucket
  *	@sk_shutdown - mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
  *	@sk_userlocks - %SO_SNDBUF and %SO_RCVBUF settings
  *	@sk_lock -	synchronizer
  *	@sk_rcvbuf - size of receive buffer in bytes
  *	@sk_sleep - sock wait queue
  *	@sk_dst_cache - destination cache
  *	@sk_dst_lock - destination cache lock
  *	@sk_policy - flow policy
  *	@sk_rmem_alloc - receive queue bytes committed
  *	@sk_receive_queue - incoming packets
  *	@sk_wmem_alloc - transmit queue bytes committed
  *	@sk_write_queue - Packet sending queue
  *	@sk_omem_alloc - "o" is "option" or "other"
  *	@sk_wmem_queued - persistent queue size
  *	@sk_forward_alloc - space allocated forward
  *	@sk_allocation - allocation mode
  *	@sk_sndbuf - size of send buffer in bytes
  *	@sk_flags - %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, %SO_OOBINLINE settings
  *	@sk_no_check - %SO_NO_CHECK setting, wether or not checkup packets
  *	@sk_route_caps - route capabilities (e.g. %NETIF_F_TSO)
  *	@sk_lingertime - %SO_LINGER l_linger setting
  *	@sk_hashent - hash entry in several tables (e.g. tcp_ehash)
  *	@sk_backlog - always used with the per-socket spinlock held
  *	@sk_callback_lock - used with the callbacks in the end of this struct
  *	@sk_error_queue - rarely used
  *	@sk_prot - protocol handlers inside a network family
  *	@sk_err - last error
  *	@sk_err_soft - errors that don't cause failure but are the cause of a persistent failure not just 'timed out'
  *	@sk_ack_backlog - current listen backlog
  *	@sk_max_ack_backlog - listen backlog set in listen()
  *	@sk_priority - %SO_PRIORITY setting
  *	@sk_type - socket type (%SOCK_STREAM, etc)
  *	@sk_protocol - which protocol this socket belongs in this network family
  *	@sk_peercred - %SO_PEERCRED setting
  *	@sk_rcvlowat - %SO_RCVLOWAT setting
  *	@sk_rcvtimeo - %SO_RCVTIMEO setting
  *	@sk_sndtimeo - %SO_SNDTIMEO setting
  *	@sk_filter - socket filtering instructions
  *	@sk_protinfo - private area, net family specific, when not using slab
  *	@sk_timer - sock cleanup timer
  *	@sk_stamp - time stamp of last packet received
  *	@sk_socket - Identd and reporting IO signals
  *	@sk_user_data - RPC layer private data
  *	@sk_sndmsg_page - cached page for sendmsg
  *	@sk_sndmsg_off - cached offset for sendmsg
  *	@sk_send_head - front of stuff to transmit
  *	@sk_write_pending