/* 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 */#ifndef _INET_CONNECTION_SOCK_H#define _INET_CONNECTION_SOCK_H #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. */#undef INET_CSK_CLEAR_TIMERS struct inet_bind_bucket;struct inet_bind2_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);	u16	    net_header_len;	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,				      void (*opt_child_init)(struct sock *newsk,							     const struct sock *sk));	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	    (*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_bind2_hash:	   Bind node in the bhash2 table * @icsk_delack_timer:     Delayed ACK timer * @icsk_keepalive_timer:  Keepalive timer * @mptcp_tout_timer: mptcp timer * @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_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;	struct inet_bind2_bucket  *icsk_bind2_hash;	struct timer_list	  icsk_delack_timer;	union {		struct timer_list icsk_keepalive_timer;		struct timer_list mptcp_tout_timer;	};	__u32			  icsk_rto;	__u32                     icsk_rto_min;	u32			  icsk_rto_max;	__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;	unsigned int		  (*icsk_sync_mss)(struct sock *sk, u32 pmtu);	__u8			  icsk_ca_state:5,				  icsk_ca_initialized:1,				  icsk_ca_setsockopt:1,				  icsk_ca_dst_locked:1;	__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			   */		#define ATO_BITS 8		__u32		  ato:ATO_BITS,	 /* Predicted tick of soft clock	   */				  lrcv_flowlabel:20, /* last received ipv6 flowlabel	   */				  dst_quick_ack:1, /* cache dst RTAX_QUICKACK		   */				  unused:3;		__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? */				  enabled:1; 		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 */ #define inet_csk(ptr) container_of_const(ptr, struct inet_connection_sock, icsk_inet.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_SCHED	= 1,	ICSK_ACK_TIMER  = 2,	ICSK_ACK_PUSHED = 4,	ICSK_ACK_PUSHED2 = 8,	ICSK_ACK_NOW = 16,	/* Send the next ACK immediately (once) */	ICSK_ACK_NOMEM = 32,}; 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);void inet_csk_clear_xmit_timers_sync(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));} static inline unsigned long tcp_timeout_expires(const struct sock *sk){	return READ_ONCE(sk->tcp_retransmit_timer.expires);} static inline unsigned longicsk_delack_timeout(const struct inet_connection_sock *icsk){	return READ_ONCE(icsk->icsk_delack_timer.expires);} 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) {		smp_store_release(&icsk->icsk_pending, 0);#ifdef INET_CSK_CLEAR_TIMERS		sk_stop_timer(sk, &sk->tcp_retransmit_timer);#endif	} else if (what == ICSK_TIME_DACK) {		smp_store_release(&icsk->icsk_ack.pending, 0);		icsk->icsk_ack.retry = 0;#ifdef INET_CSK_CLEAR_TIMERS		sk_stop_timer(sk, &icsk->icsk_delack_timer);#endif	} 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;	} 	when += jiffies;	if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||	    what == ICSK_TIME_LOSS_PROBE || what == ICSK_TIME_REO_TIMEOUT) {		smp_store_release(&icsk->icsk_pending, what);		sk_reset_timer(sk, &sk->tcp_retransmit_timer, when);	} else if (what == ICSK_TIME_DACK) {		smp_store_release(&icsk->icsk_ack.pending,				  icsk->icsk_ack.pending | ICSK_ACK_TIMER);		sk_reset_timer(sk, &icsk->icsk_delack_timer, when);	} else {		pr_debug("inet_csk BUG: unknown timer value\n");	}} static inline unsigned longinet_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, struct proto_accept_arg *arg); 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);bool inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req);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){	reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);} 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) > READ_ONCE(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); void inet_csk_destroy_sock(struct sock *sk);void inet_csk_prepare_for_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) ?			(EPOLLIN | EPOLLRDNORM) : 0;} int inet_csk_listen_start(struct sock *sk);void inet_csk_listen_stop(struct sock *sk); /* update the fast reuse flag when adding a socket */void inet_csk_update_fastreuse(const struct sock *sk,			       struct inet_bind_bucket *tb,			       struct inet_bind2_bucket *tb2); 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 =		READ_ONCE(sock_net(sk)->ipv4.sysctl_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 >=	       READ_ONCE(sock_net(sk)->ipv4.sysctl_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)		icsk->icsk_ack.pingpong++;} static inline bool inet_csk_has_ulp(const struct sock *sk){	return inet_test_bit(IS_ICSK, sk) && !!inet_csk(sk)->icsk_ulp_ops;} static inline void inet_init_csk_locks(struct sock *sk){	struct inet_connection_sock *icsk = inet_csk(sk); 	spin_lock_init(&icsk->icsk_accept_queue.rskq_lock);	spin_lock_init(&icsk->icsk_accept_queue.fastopenq.lock);} #endif /* _INET_CONNECTION_SOCK_H */