inet_connection_sock.h revision 9f1d2604c71498579609b1532fedc5a89276bb00 
1/*
2 * NET		Generic infrastructure for INET connection oriented protocols.
3 *
4 *		Definitions for inet_connection_sock
5 *
6 * Authors:	Many people, see the TCP sources
7 *
8 * 		From code originally in TCP
9 *
10 *		This program is free software; you can redistribute it and/or
11 *		modify it under the terms of the GNU General Public License
12 *		as published by the Free Software Foundation; either version
13 *		2 of the License, or (at your option) any later version.
14 */
15#ifndef _INET_CONNECTION_SOCK_H
16#define _INET_CONNECTION_SOCK_H
17
18#include <linux/ip.h>
19#include <linux/string.h>
20#include <linux/timer.h>
21#include <net/request_sock.h>
22
23#define INET_CSK_DEBUG 1
24
25/* Cancel timers, when they are not required. */
26#undef INET_CSK_CLEAR_TIMERS
27
28struct inet_bind_bucket;
29struct inet_hashinfo;
30
31/** inet_connection_sock - INET connection oriented sock
32 *
33 * @icsk_accept_queue:	   FIFO of established children
34 * @icsk_bind_hash:	   Bind node
35 * @icsk_timeout:	   Timeout
36 * @icsk_retransmit_timer: Resend (no ack)
37 * @icsk_rto:		   Retransmit timeout
38 * @icsk_retransmits:	   Number of unrecovered [RTO] timeouts
39 * @icsk_pending:	   Scheduled timer event
40 * @icsk_backoff:	   Backoff
41 * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
42 * @icsk_ack:		   Delayed ACK control data
43 */
44struct inet_connection_sock {
45	/* inet_sock has to be the first member! */
46	struct inet_sock	  icsk_inet;
47	struct request_sock_queue icsk_accept_queue;
48	struct inet_bind_bucket	  *icsk_bind_hash;
49	unsigned long		  icsk_timeout;
50 	struct timer_list	  icsk_retransmit_timer;
51 	struct timer_list	  icsk_delack_timer;
52	__u32			  icsk_rto;
53	__u8			  icsk_retransmits;
54	__u8			  icsk_pending;
55	__u8			  icsk_backoff;
56	__u8			  icsk_syn_retries;
57	struct {
58		__u8		  pending;	 /* ACK is pending			   */
59		__u8		  quick;	 /* Scheduled number of quick acks	   */
60		__u8		  pingpong;	 /* The session is interactive		   */
61		__u8		  blocked;	 /* Delayed ACK was blocked by socket lock */
62		__u32		  ato;		 /* Predicted tick of soft clock	   */
63		unsigned long	  timeout;	 /* Currently scheduled timeout		   */
64		__u32		  lrcvtime;	 /* timestamp of last received data packet */
65		__u16		  last_seg_size; /* Size of last incoming segment	   */
66		__u16		  rcv_mss;	 /* MSS used for delayed ACK decisions	   */
67	} icsk_ack;
68};
69
70#define ICSK_TIME_RETRANS	1	/* Retransmit timer */
71#define ICSK_TIME_DACK		2	/* Delayed ack timer */
72#define ICSK_TIME_PROBE0	3	/* Zero window probe timer */
73#define ICSK_TIME_KEEPOPEN	4	/* Keepalive timer */
74
75static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
76{
77	return (struct inet_connection_sock *)sk;
78}
79
80extern struct sock *inet_csk_clone(struct sock *sk,
81				   const struct request_sock *req,
82				   const unsigned int __nocast priority);
83
84enum inet_csk_ack_state_t {
85	ICSK_ACK_SCHED	= 1,
86	ICSK_ACK_TIMER  = 2,
87	ICSK_ACK_PUSHED = 4
88};
89
90extern void inet_csk_init_xmit_timers(struct sock *sk,
91				      void (*retransmit_handler)(unsigned long),
92				      void (*delack_handler)(unsigned long),
93				      void (*keepalive_handler)(unsigned long));
94extern void inet_csk_clear_xmit_timers(struct sock *sk);
95
96static inline void inet_csk_schedule_ack(struct sock *sk)
97{
98	inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
99}
100
101static inline int inet_csk_ack_scheduled(const struct sock *sk)
102{
103	return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
104}
105
106static inline void inet_csk_delack_init(struct sock *sk)
107{
108	memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
109}
110
111extern void inet_csk_delete_keepalive_timer(struct sock *sk);
112extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
113
114#ifdef INET_CSK_DEBUG
115extern const char inet_csk_timer_bug_msg[];
116#endif
117
118static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
119{
120	struct inet_connection_sock *icsk = inet_csk(sk);
121
122	if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
123		icsk->icsk_pending = 0;
124#ifdef INET_CSK_CLEAR_TIMERS
125		sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
126#endif
127	} else if (what == ICSK_TIME_DACK) {
128		icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
129#ifdef INET_CSK_CLEAR_TIMERS
130		sk_stop_timer(sk, &icsk->icsk_delack_timer);
131#endif
132	}
133#ifdef INET_CSK_DEBUG
134	else {
135		pr_debug(inet_csk_timer_bug_msg);
136	}
137#endif
138}
139
140/*
141 *	Reset the retransmission timer
142 */
143static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
144					     unsigned long when,
145					     const unsigned long max_when)
146{
147	struct inet_connection_sock *icsk = inet_csk(sk);
148
149	if (when > max_when) {
150#ifdef INET_CSK_DEBUG
151		pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
152			 sk, what, when, current_text_addr());
153#endif
154		when = max_when;
155	}
156
157	if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
158		icsk->icsk_pending = what;
159		icsk->icsk_timeout = jiffies + when;
160		sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
161	} else if (what == ICSK_TIME_DACK) {
162		icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
163		icsk->icsk_ack.timeout = jiffies + when;
164		sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
165	}
166#ifdef INET_CSK_DEBUG
167	else {
168		pr_debug(inet_csk_timer_bug_msg);
169	}
170#endif
171}
172
173extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
174
175extern struct request_sock *inet_csk_search_req(const struct sock *sk,
176						struct request_sock ***prevp,
177						const __u16 rport,
178						const __u32 raddr,
179						const __u32 laddr);
180extern int inet_csk_get_port(struct inet_hashinfo *hashinfo,
181			     struct sock *sk, unsigned short snum);
182
183extern struct dst_entry* inet_csk_route_req(struct sock *sk,
184					    const struct request_sock *req);
185
186static inline void inet_csk_reqsk_queue_add(struct sock *sk,
187					    struct request_sock *req,
188					    struct sock *child)
189{
190	reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
191}
192
193extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
194					  struct request_sock *req,
195					  const unsigned timeout);
196
197static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
198						struct request_sock *req)
199{
200	if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
201		inet_csk_delete_keepalive_timer(sk);
202}
203
204static inline void inet_csk_reqsk_queue_added(struct sock *sk,
205					      const unsigned long timeout)
206{
207	if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
208		inet_csk_reset_keepalive_timer(sk, timeout);
209}
210
211static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
212{
213	return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
214}
215
216static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
217{
218	return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
219}
220
221static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
222{
223	return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
224}
225
226static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
227					       struct request_sock *req,
228					       struct request_sock **prev)
229{
230	reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
231}
232
233static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
234					     struct request_sock *req,
235					     struct request_sock **prev)
236{
237	inet_csk_reqsk_queue_unlink(sk, req, prev);
238	inet_csk_reqsk_queue_removed(sk, req);
239	reqsk_free(req);
240}
241
242#endif /* _INET_CONNECTION_SOCK_H */
243