1ef9696c90
It does not affect either mss-sized connections (obviously) or connections controlled by Nagle (because there is only one small segment in flight). The idea is to record the fact that a small segment arrives on a connection, where one small segment has already been received and still not-ACKed. In this case ACK is forced after tcp_recvmsg() drains receive buffer. In other words, it is a "soft" each-2nd-segment ACK, which is enough to preserve ACK clock even when ABC is enabled. Signed-off-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
340 lines
11 KiB
C
340 lines
11 KiB
C
/*
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* NET Generic infrastructure for INET connection oriented protocols.
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*
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* Definitions for inet_connection_sock
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*
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* Authors: Many people, see the TCP sources
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*
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* From code originally in TCP
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _INET_CONNECTION_SOCK_H
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#define _INET_CONNECTION_SOCK_H
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#include <linux/compiler.h>
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#include <linux/string.h>
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#include <linux/timer.h>
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#include <net/inet_sock.h>
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#include <net/request_sock.h>
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#define INET_CSK_DEBUG 1
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/* Cancel timers, when they are not required. */
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#undef INET_CSK_CLEAR_TIMERS
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struct inet_bind_bucket;
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struct inet_hashinfo;
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struct tcp_congestion_ops;
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/*
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* Pointers to address related TCP functions
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* (i.e. things that depend on the address family)
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*/
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struct inet_connection_sock_af_ops {
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int (*queue_xmit)(struct sk_buff *skb, int ipfragok);
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void (*send_check)(struct sock *sk, int len,
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struct sk_buff *skb);
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int (*rebuild_header)(struct sock *sk);
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int (*conn_request)(struct sock *sk, struct sk_buff *skb);
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struct sock *(*syn_recv_sock)(struct sock *sk, struct sk_buff *skb,
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struct request_sock *req,
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struct dst_entry *dst);
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int (*remember_stamp)(struct sock *sk);
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__u16 net_header_len;
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int (*setsockopt)(struct sock *sk, int level, int optname,
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char __user *optval, int optlen);
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int (*getsockopt)(struct sock *sk, int level, int optname,
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char __user *optval, int __user *optlen);
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int (*compat_setsockopt)(struct sock *sk,
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int level, int optname,
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char __user *optval, int optlen);
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int (*compat_getsockopt)(struct sock *sk,
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int level, int optname,
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char __user *optval, int __user *optlen);
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void (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
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int sockaddr_len;
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};
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/** inet_connection_sock - INET connection oriented sock
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*
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* @icsk_accept_queue: FIFO of established children
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* @icsk_bind_hash: Bind node
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* @icsk_timeout: Timeout
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* @icsk_retransmit_timer: Resend (no ack)
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* @icsk_rto: Retransmit timeout
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* @icsk_pmtu_cookie Last pmtu seen by socket
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* @icsk_ca_ops Pluggable congestion control hook
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* @icsk_af_ops Operations which are AF_INET{4,6} specific
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* @icsk_ca_state: Congestion control state
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* @icsk_retransmits: Number of unrecovered [RTO] timeouts
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* @icsk_pending: Scheduled timer event
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* @icsk_backoff: Backoff
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* @icsk_syn_retries: Number of allowed SYN (or equivalent) retries
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* @icsk_probes_out: unanswered 0 window probes
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* @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options)
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* @icsk_ack: Delayed ACK control data
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* @icsk_mtup; MTU probing control data
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*/
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struct inet_connection_sock {
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/* inet_sock has to be the first member! */
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struct inet_sock icsk_inet;
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struct request_sock_queue icsk_accept_queue;
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struct inet_bind_bucket *icsk_bind_hash;
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unsigned long icsk_timeout;
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struct timer_list icsk_retransmit_timer;
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struct timer_list icsk_delack_timer;
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__u32 icsk_rto;
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__u32 icsk_pmtu_cookie;
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const struct tcp_congestion_ops *icsk_ca_ops;
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const struct inet_connection_sock_af_ops *icsk_af_ops;
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unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
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__u8 icsk_ca_state;
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__u8 icsk_retransmits;
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__u8 icsk_pending;
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__u8 icsk_backoff;
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__u8 icsk_syn_retries;
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__u8 icsk_probes_out;
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__u16 icsk_ext_hdr_len;
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struct {
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__u8 pending; /* ACK is pending */
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__u8 quick; /* Scheduled number of quick acks */
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__u8 pingpong; /* The session is interactive */
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__u8 blocked; /* Delayed ACK was blocked by socket lock */
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__u32 ato; /* Predicted tick of soft clock */
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unsigned long timeout; /* Currently scheduled timeout */
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__u32 lrcvtime; /* timestamp of last received data packet */
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__u16 last_seg_size; /* Size of last incoming segment */
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__u16 rcv_mss; /* MSS used for delayed ACK decisions */
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} icsk_ack;
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struct {
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int enabled;
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/* Range of MTUs to search */
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int search_high;
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int search_low;
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/* Information on the current probe. */
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int probe_size;
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} icsk_mtup;
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u32 icsk_ca_priv[16];
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#define ICSK_CA_PRIV_SIZE (16 * sizeof(u32))
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};
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#define ICSK_TIME_RETRANS 1 /* Retransmit timer */
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#define ICSK_TIME_DACK 2 /* Delayed ack timer */
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#define ICSK_TIME_PROBE0 3 /* Zero window probe timer */
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#define ICSK_TIME_KEEPOPEN 4 /* Keepalive timer */
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static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
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{
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return (struct inet_connection_sock *)sk;
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}
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static inline void *inet_csk_ca(const struct sock *sk)
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{
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return (void *)inet_csk(sk)->icsk_ca_priv;
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}
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extern struct sock *inet_csk_clone(struct sock *sk,
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const struct request_sock *req,
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const gfp_t priority);
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enum inet_csk_ack_state_t {
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ICSK_ACK_SCHED = 1,
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ICSK_ACK_TIMER = 2,
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ICSK_ACK_PUSHED = 4,
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ICSK_ACK_PUSHED2 = 8
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};
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extern void inet_csk_init_xmit_timers(struct sock *sk,
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void (*retransmit_handler)(unsigned long),
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void (*delack_handler)(unsigned long),
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void (*keepalive_handler)(unsigned long));
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extern void inet_csk_clear_xmit_timers(struct sock *sk);
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static inline void inet_csk_schedule_ack(struct sock *sk)
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{
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inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
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}
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static inline int inet_csk_ack_scheduled(const struct sock *sk)
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{
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return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
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}
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static inline void inet_csk_delack_init(struct sock *sk)
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{
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memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
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}
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extern void inet_csk_delete_keepalive_timer(struct sock *sk);
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extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
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#ifdef INET_CSK_DEBUG
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extern const char inet_csk_timer_bug_msg[];
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#endif
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static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
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{
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struct inet_connection_sock *icsk = inet_csk(sk);
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if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
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icsk->icsk_pending = 0;
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#ifdef INET_CSK_CLEAR_TIMERS
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sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
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#endif
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} else if (what == ICSK_TIME_DACK) {
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icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
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#ifdef INET_CSK_CLEAR_TIMERS
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sk_stop_timer(sk, &icsk->icsk_delack_timer);
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#endif
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}
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#ifdef INET_CSK_DEBUG
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else {
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pr_debug("%s", inet_csk_timer_bug_msg);
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}
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#endif
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}
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/*
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* Reset the retransmission timer
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*/
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static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
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unsigned long when,
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const unsigned long max_when)
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{
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struct inet_connection_sock *icsk = inet_csk(sk);
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if (when > max_when) {
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#ifdef INET_CSK_DEBUG
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pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
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sk, what, when, current_text_addr());
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#endif
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when = max_when;
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}
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if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
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icsk->icsk_pending = what;
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icsk->icsk_timeout = jiffies + when;
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sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
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} else if (what == ICSK_TIME_DACK) {
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icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
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icsk->icsk_ack.timeout = jiffies + when;
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sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
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}
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#ifdef INET_CSK_DEBUG
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else {
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pr_debug("%s", inet_csk_timer_bug_msg);
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}
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#endif
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}
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extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
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extern struct request_sock *inet_csk_search_req(const struct sock *sk,
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struct request_sock ***prevp,
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const __u16 rport,
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const __u32 raddr,
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const __u32 laddr);
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extern int inet_csk_bind_conflict(const struct sock *sk,
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const struct inet_bind_bucket *tb);
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extern int inet_csk_get_port(struct inet_hashinfo *hashinfo,
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struct sock *sk, unsigned short snum,
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int (*bind_conflict)(const struct sock *sk,
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const struct inet_bind_bucket *tb));
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extern struct dst_entry* inet_csk_route_req(struct sock *sk,
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const struct request_sock *req);
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static inline void inet_csk_reqsk_queue_add(struct sock *sk,
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struct request_sock *req,
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struct sock *child)
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{
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reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
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}
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extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
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struct request_sock *req,
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unsigned long timeout);
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static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
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struct request_sock *req)
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{
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if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
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inet_csk_delete_keepalive_timer(sk);
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}
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static inline void inet_csk_reqsk_queue_added(struct sock *sk,
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const unsigned long timeout)
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{
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if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
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inet_csk_reset_keepalive_timer(sk, timeout);
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}
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static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
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{
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return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
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}
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static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
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{
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return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
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}
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static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
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{
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return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
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}
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static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
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struct request_sock *req,
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struct request_sock **prev)
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{
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reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
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}
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static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
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struct request_sock *req,
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struct request_sock **prev)
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{
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inet_csk_reqsk_queue_unlink(sk, req, prev);
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inet_csk_reqsk_queue_removed(sk, req);
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reqsk_free(req);
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}
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extern void inet_csk_reqsk_queue_prune(struct sock *parent,
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const unsigned long interval,
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const unsigned long timeout,
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const unsigned long max_rto);
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extern void inet_csk_destroy_sock(struct sock *sk);
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/*
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* LISTEN is a special case for poll..
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*/
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static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
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{
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return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
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(POLLIN | POLLRDNORM) : 0;
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}
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extern int inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
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extern void inet_csk_listen_stop(struct sock *sk);
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extern void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
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extern int inet_csk_ctl_sock_create(struct socket **sock,
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unsigned short family,
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unsigned short type,
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unsigned char protocol);
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extern int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
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char __user *optval, int __user *optlen);
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extern int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
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char __user *optval, int optlen);
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#endif /* _INET_CONNECTION_SOCK_H */
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