STRUCT SOCK(9)

NAME
struct sock - network layer representation of sockets

SYNOPSIS
struct sock {
  struct sock_common __sk_common;
#define sk_family		__sk_common.skc_family
#define sk_state		__sk_common.skc_state
#define sk_reuse		__sk_common.skc_reuse
#define sk_bound_dev_if		__sk_common.skc_bound_dev_if
#define sk_node			__sk_common.skc_node
#define sk_bind_node		__sk_common.skc_bind_node
#define sk_refcnt		__sk_common.skc_refcnt
#define sk_hash			__sk_common.skc_hash
#define sk_prot			__sk_common.skc_prot
  unsigned char sk_shutdown:2;
  unsigned char sk_no_check:2;
  unsigned char sk_userlocks:4;
  unsigned char sk_protocol;
  unsigned short sk_type;
  int sk_rcvbuf;
  socket_lock_t sk_lock;
  wait_queue_head_t * sk_sleep;
  struct dst_entry * sk_dst_cache;
  struct xfrm_policy * sk_policy[2];
  rwlock_t sk_dst_lock;
  atomic_t sk_rmem_alloc;
  atomic_t sk_wmem_alloc;
  atomic_t sk_omem_alloc;
  struct sk_buff_head sk_receive_queue;
  struct sk_buff_head sk_write_queue;
  int sk_wmem_queued;
  int sk_forward_alloc;
  gfp_t sk_allocation;
  int sk_sndbuf;
  int sk_route_caps;
  unsigned long sk_flags;
  unsigned long sk_lingertime;
  struct sk_backlog;
  struct sk_buff_head sk_error_queue;
  struct proto * sk_prot_creator;
  rwlock_t sk_callback_lock;
  int sk_err;
  int sk_err_soft;
  unsigned short sk_ack_backlog;
  unsigned short sk_max_ack_backlog;
  __u32 sk_priority;
  struct ucred sk_peercred;
  int sk_rcvlowat;
  long sk_rcvtimeo;
  long sk_sndtimeo;
  struct sk_filter * sk_filter;
  void * sk_protinfo;
  struct timer_list sk_timer;
  struct timeval sk_stamp;
  struct socket * sk_socket;
  void * sk_user_data;
  struct page * sk_sndmsg_page;
  struct sk_buff * sk_send_head;
  __u32 sk_sndmsg_off;
  int sk_write_pending;
  void * sk_security;
  void (* sk_state_change) (struct sock *sk);
  void (* sk_data_ready) (struct sock *sk, int bytes);
  void (* sk_write_space) (struct sock *sk);
  void (* sk_error_report) (struct sock *sk);
  int (* sk_backlog_rcv) (struct sock *sk,struct sk_buff *skb);
  void (* sk_destruct) (struct sock *sk);
};

MEMBERS

__sk_common
    shared layout with inet_timewait_sock

sk_shutdown
    mask of SEND_SHUTDOWN and/or RCV_SHUTDOWN

sk_no_check
     SO_NO_CHECK setting, wether or not checkup packets

sk_userlocks
     SO_SNDBUF and SO_RCVBUF settings

sk_protocol
    which protocol this socket belongs in this network family

sk_type
    socket type (SOCK_STREAM, etc)

sk_rcvbuf
    size of receive buffer in bytes

sk_lock
    synchronizer

sk_sleep
    sock wait queue

sk_dst_cache
    destination cache

sk_policy[2]
    flow policy

sk_dst_lock
    destination cache lock

sk_rmem_alloc
    receive queue bytes committed

sk_wmem_alloc
    transmit queue bytes committed

sk_omem_alloc
     ``o'' is ``option'' or ``other''

sk_receive_queue
    incoming packets

sk_write_queue
    Packet sending queue

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_route_caps
    route capabilities (e.g. NETIF_F_TSO)

sk_flags
     SO_LINGER (l_onoff), SO_BROADCAST, SO_KEEPALIVE, SO_OOBINLINE settings

sk_lingertime
     SO_LINGER l_linger setting

sk_backlog
    always used with the per-socket spinlock held

sk_error_queue
    rarely used

sk_prot_creator
    sk_prot of original sock creator (see ipv6_setsockopt, IPV6_ADDRFORM for instance)

sk_callback_lock
    used with the callbacks in the end of this struct

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_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_send_head
    front of stuff to transmit

sk_sndmsg_off
    cached offset for sendmsg

sk_write_pending
    a write to stream socket waits to start

sk_security
    used by security modules

sk_state_change
    callback to indicate change in the state of the sock

sk_data_ready
    callback to indicate there is data to be processed

sk_write_space
    callback to indicate there is bf sending space available

sk_error_report
    callback to indicate errors (e.g. MSG_ERRQUEUE)

sk_backlog_rcv
    callback to process the backlog

sk_destruct
    called at sock freeing time, i.e. when all refcnt == 0