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struct_sock(9) [centos man page]

STRUCT 
SOCK(9) Linux Networking STRUCT SOCK(9) NAME
struct_sock - network layer representation of sockets SYNOPSIS
struct sock { struct sock_common __sk_common; #define sk_node __sk_common.skc_node #define sk_nulls_node __sk_common.skc_nulls_node #define sk_refcnt __sk_common.skc_refcnt #define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping #define sk_dontcopy_begin __sk_common.skc_dontcopy_begin #define sk_dontcopy_end __sk_common.skc_dontcopy_end #define sk_hash __sk_common.skc_hash #define sk_portpair __sk_common.skc_portpair #define sk_num __sk_common.skc_num #define sk_dport __sk_common.skc_dport #define sk_addrpair __sk_common.skc_addrpair #define sk_daddr __sk_common.skc_daddr #define sk_rcv_saddr __sk_common.skc_rcv_saddr #define sk_family __sk_common.skc_family #define sk_state __sk_common.skc_state #define sk_reuse __sk_common.skc_reuse #define sk_reuseport __sk_common.skc_reuseport #define sk_bound_dev_if __sk_common.skc_bound_dev_if #define sk_bind_node __sk_common.skc_bind_node #define sk_prot __sk_common.skc_prot #define sk_net __sk_common.skc_net #define sk_v6_daddr __sk_common.skc_v6_daddr #define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr socket_lock_t sk_lock; struct sk_buff_head sk_receive_queue; struct sk_backlog; #define sk_rmem_alloc sk_backlog.rmem_alloc int sk_forward_alloc; #ifdef CONFIG_RPS __u32 sk_rxhash; #endif #ifdef CONFIG_NET_RX_BUSY_POLL unsigned int sk_napi_id; unsigned int sk_ll_usec; #endif atomic_t sk_drops; int sk_rcvbuf; struct sk_filter __rcu * sk_filter; struct socket_wq __rcu * sk_wq; #ifdef CONFIG_NET_DMA struct sk_buff_head sk_async_wait_queue; #endif #ifdef CONFIG_XFRM struct xfrm_policy * sk_policy[2]; #endif unsigned long sk_flags; struct dst_entry * sk_rx_dst; struct dst_entry __rcu * sk_dst_cache; spinlock_t sk_dst_lock; atomic_t sk_wmem_alloc; atomic_t sk_omem_alloc; int sk_sndbuf; struct sk_buff_head sk_write_queue; unsigned int sk_shutdown:2; unsigned int sk_no_check:2; unsigned int sk_userlocks:4; unsigned int sk_protocol:8; unsigned int sk_type:16; int sk_wmem_queued; gfp_t sk_allocation; u32 sk_pacing_rate; netdev_features_t sk_route_caps; netdev_features_t sk_route_nocaps; int sk_gso_type; unsigned int sk_gso_max_size; u16 sk_gso_max_segs; int sk_rcvlowat; unsigned long sk_lingertime; 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; #if IS_ENABLED(CONFIG_NETPRIO_CGROUP) __u32 sk_cgrp_prioidx; #endif struct pid * sk_peer_pid; const struct cred * sk_peer_cred; long sk_rcvtimeo; long sk_sndtimeo; void * sk_protinfo; struct timer_list sk_timer; ktime_t sk_stamp; struct socket * sk_socket; void * sk_user_data; struct page_frag sk_frag; struct sk_buff * sk_send_head; __s32 sk_peek_off; int sk_write_pending; #ifdef CONFIG_SECURITY void * sk_security; #endif __u32 sk_mark; u32 sk_classid; struct cg_proto * sk_cgrp; 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_lock synchronizer sk_receive_queue incoming packets sk_backlog always used with the per-socket spinlock held sk_forward_alloc space allocated forward sk_rxhash flow hash received from netif layer sk_napi_id id of the last napi context to receive data for sk sk_ll_usec usecs to busypoll when there is no data sk_drops raw/udp drops counter sk_rcvbuf size of receive buffer in bytes sk_filter socket filtering instructions sk_wq sock wait queue and async head sk_async_wait_queue DMA copied packets sk_policy[2] flow policy sk_flags SO_LINGER (l_onoff), SO_BROADCAST, SO_KEEPALIVE, SO_OOBINLINE settings, SO_TIMESTAMPING settings sk_rx_dst receive input route used by early tcp demux sk_dst_cache destination cache sk_dst_lock destination cache lock sk_wmem_alloc transmit queue bytes committed sk_omem_alloc "o" is "option" or "other" sk_sndbuf size of send buffer in bytes sk_write_queue Packet sending queue sk_shutdown mask of SEND_SHUTDOWN and/or RCV_SHUTDOWN sk_no_check SO_NO_CHECK setting, whether 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_wmem_queued persistent queue size sk_allocation allocation mode sk_pacing_rate Pacing rate (if supported by transport/packet scheduler) sk_route_caps route capabilities (e.g. NETIF_F_TSO) sk_route_nocaps forbidden route capabilities (e.g NETIF_F_GSO_MASK) sk_gso_type GSO type (e.g. SKB_GSO_TCPV4) sk_gso_max_size Maximum GSO segment size to build sk_gso_max_segs Maximum number of GSO segments sk_rcvlowat SO_RCVLOWAT setting sk_lingertime SO_LINGER l_linger setting 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_cgrp_prioidx socket group's priority map index sk_peer_pid struct pid for this socket's peer sk_peer_cred SO_PEERCRED setting sk_rcvtimeo SO_RCVTIMEO setting sk_sndtimeo SO_SNDTIMEO setting 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_frag cached page frag sk_send_head front of stuff to transmit sk_peek_off current peek_offset value sk_write_pending a write to stream socket waits to start sk_security used by security modules sk_mark generic packet mark sk_classid this socket's cgroup classid sk_cgrp this socket's cgroup-specific proto data 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 COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 STRUCT SOCK(9)

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