blob: fa6a87246a7b85d3358b6ec66e6029445fe3b066 [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0-or-later */
* NET Generic infrastructure for INET connection oriented protocols.
* Definitions for inet_connection_sock
* Authors: Many people, see the TCP sources
* From code originally in TCP
#include <linux/compiler.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/poll.h>
#include <linux/kernel.h>
#include <linux/sockptr.h>
#include <net/inet_sock.h>
#include <net/request_sock.h>
/* Cancel timers, when they are not required. */
struct inet_bind_bucket;
struct tcp_congestion_ops;
* Pointers to address related TCP functions
* (i.e. things that depend on the address family)
struct inet_connection_sock_af_ops {
int (*queue_xmit)(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
void (*send_check)(struct sock *sk, struct sk_buff *skb);
int (*rebuild_header)(struct sock *sk);
void (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb);
int (*conn_request)(struct sock *sk, struct sk_buff *skb);
struct sock *(*syn_recv_sock)(const struct sock *sk, struct sk_buff *skb,
struct request_sock *req,
struct dst_entry *dst,
struct request_sock *req_unhash,
bool *own_req);
u16 net_header_len;
u16 net_frag_header_len;
u16 sockaddr_len;
int (*setsockopt)(struct sock *sk, int level, int optname,
sockptr_t optval, unsigned int optlen);
int (*getsockopt)(struct sock *sk, int level, int optname,
char __user *optval, int __user *optlen);
void (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
void (*mtu_reduced)(struct sock *sk);
/** inet_connection_sock - INET connection oriented sock
* @icsk_accept_queue: FIFO of established children
* @icsk_bind_hash: Bind node
* @icsk_timeout: Timeout
* @icsk_retransmit_timer: Resend (no ack)
* @icsk_rto: Retransmit timeout
* @icsk_pmtu_cookie Last pmtu seen by socket
* @icsk_ca_ops Pluggable congestion control hook
* @icsk_af_ops Operations which are AF_INET{4,6} specific
* @icsk_ulp_ops Pluggable ULP control hook
* @icsk_ulp_data ULP private data
* @icsk_clean_acked Clean acked data hook
* @icsk_listen_portaddr_node hash to the portaddr listener hashtable
* @icsk_ca_state: Congestion control state
* @icsk_retransmits: Number of unrecovered [RTO] timeouts
* @icsk_pending: Scheduled timer event
* @icsk_backoff: Backoff
* @icsk_syn_retries: Number of allowed SYN (or equivalent) retries
* @icsk_probes_out: unanswered 0 window probes
* @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options)
* @icsk_ack: Delayed ACK control data
* @icsk_mtup; MTU probing control data
* @icsk_probes_tstamp: Probe timestamp (cleared by non-zero window ack)
* @icsk_user_timeout: TCP_USER_TIMEOUT value
struct inet_connection_sock {
/* inet_sock has to be the first member! */
struct inet_sock icsk_inet;
struct request_sock_queue icsk_accept_queue;
struct inet_bind_bucket *icsk_bind_hash;
unsigned long icsk_timeout;
struct timer_list icsk_retransmit_timer;
struct timer_list icsk_delack_timer;
__u32 icsk_rto;
__u32 icsk_rto_min;
__u32 icsk_delack_max;
__u32 icsk_pmtu_cookie;
const struct tcp_congestion_ops *icsk_ca_ops;
const struct inet_connection_sock_af_ops *icsk_af_ops;
const struct tcp_ulp_ops *icsk_ulp_ops;
void __rcu *icsk_ulp_data;
void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq);
struct hlist_node icsk_listen_portaddr_node;
unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
__u8 icsk_ca_state:5,
__u8 icsk_retransmits;
__u8 icsk_pending;
__u8 icsk_backoff;
__u8 icsk_syn_retries;
__u8 icsk_probes_out;
__u16 icsk_ext_hdr_len;
struct {
__u8 pending; /* ACK is pending */
__u8 quick; /* Scheduled number of quick acks */
__u8 pingpong; /* The session is interactive */
__u8 retry; /* Number of attempts */
__u32 ato; /* Predicted tick of soft clock */
unsigned long timeout; /* Currently scheduled timeout */
__u32 lrcvtime; /* timestamp of last received data packet */
__u16 last_seg_size; /* Size of last incoming segment */
__u16 rcv_mss; /* MSS used for delayed ACK decisions */
} icsk_ack;
struct {
/* Range of MTUs to search */
int search_high;
int search_low;
/* Information on the current probe. */
u32 probe_size:31,
/* Is the MTUP feature enabled for this connection? */
u32 probe_timestamp;
} icsk_mtup;
u32 icsk_probes_tstamp;
u32 icsk_user_timeout;
u64 icsk_ca_priv[104 / sizeof(u64)];
#define ICSK_CA_PRIV_SIZE sizeof_field(struct inet_connection_sock, icsk_ca_priv)
#define ICSK_TIME_RETRANS 1 /* Retransmit timer */
#define ICSK_TIME_DACK 2 /* Delayed ack timer */
#define ICSK_TIME_PROBE0 3 /* Zero window probe timer */
#define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */
#define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */
static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
return (struct inet_connection_sock *)sk;
static inline void *inet_csk_ca(const struct sock *sk)
return (void *)inet_csk(sk)->icsk_ca_priv;
struct sock *inet_csk_clone_lock(const struct sock *sk,
const struct request_sock *req,
const gfp_t priority);
enum inet_csk_ack_state_t {
ICSK_ACK_NOW = 16 /* Send the next ACK immediately (once) */
void inet_csk_init_xmit_timers(struct sock *sk,
void (*retransmit_handler)(struct timer_list *),
void (*delack_handler)(struct timer_list *),
void (*keepalive_handler)(struct timer_list *));
void inet_csk_clear_xmit_timers(struct sock *sk);
static inline void inet_csk_schedule_ack(struct sock *sk)
inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
static inline int inet_csk_ack_scheduled(const struct sock *sk)
return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
static inline void inet_csk_delack_init(struct sock *sk)
memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
void inet_csk_delete_keepalive_timer(struct sock *sk);
void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
struct inet_connection_sock *icsk = inet_csk(sk);
if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
icsk->icsk_pending = 0;
sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
} else if (what == ICSK_TIME_DACK) {
icsk->icsk_ack.pending = 0;
icsk->icsk_ack.retry = 0;
sk_stop_timer(sk, &icsk->icsk_delack_timer);
} else {
pr_debug("inet_csk BUG: unknown timer value\n");
* Reset the retransmission timer
static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
unsigned long when,
const unsigned long max_when)
struct inet_connection_sock *icsk = inet_csk(sk);
if (when > max_when) {
pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
sk, what, when, (void *)_THIS_IP_);
when = max_when;
if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
icsk->icsk_pending = what;
icsk->icsk_timeout = jiffies + when;
sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
} else if (what == ICSK_TIME_DACK) {
icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
icsk->icsk_ack.timeout = jiffies + when;
sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
} else {
pr_debug("inet_csk BUG: unknown timer value\n");
static inline unsigned long
inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
unsigned long max_when)
u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
return (unsigned long)min_t(u64, when, max_when);
struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern);
int inet_csk_get_port(struct sock *sk, unsigned short snum);
struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4,
const struct request_sock *req);
struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
struct sock *newsk,
const struct request_sock *req);
struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
struct request_sock *req,
struct sock *child);
void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
unsigned long timeout);
struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
struct request_sock *req,
bool own_req);
static inline void inet_csk_reqsk_queue_added(struct sock *sk)
static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog;
bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);
static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk)
/* The below has to be done to allow calling inet_csk_destroy_sock */
sock_set_flag(sk, SOCK_DEAD);
void inet_csk_destroy_sock(struct sock *sk);
void inet_csk_prepare_forced_close(struct sock *sk);
* LISTEN is a special case for poll..
static inline __poll_t inet_csk_listen_poll(const struct sock *sk)
return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
int inet_csk_listen_start(struct sock *sk, int backlog);
void inet_csk_listen_stop(struct sock *sk);
void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
/* update the fast reuse flag when adding a socket */
void inet_csk_update_fastreuse(struct inet_bind_bucket *tb,
struct sock *sk);
struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
static inline void inet_csk_enter_pingpong_mode(struct sock *sk)
inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH;
static inline void inet_csk_exit_pingpong_mode(struct sock *sk)
inet_csk(sk)->icsk_ack.pingpong = 0;
static inline bool inet_csk_in_pingpong_mode(struct sock *sk)
return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH;
static inline void inet_csk_inc_pingpong_cnt(struct sock *sk)
struct inet_connection_sock *icsk = inet_csk(sk);
if (icsk->icsk_ack.pingpong < U8_MAX)
static inline bool inet_csk_has_ulp(struct sock *sk)
return inet_sk(sk)->is_icsk && !!inet_csk(sk)->icsk_ulp_ops;