inet_connection_sock.h revision d8971fcb702e24d1e22c77fd1772f182ffee87e3 
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;
30struct tcp_congestion_ops;
31
32/** inet_connection_sock - INET connection oriented sock
33 *
34 * @icsk_accept_queue:	   FIFO of established children
35 * @icsk_bind_hash:	   Bind node
36 * @icsk_timeout:	   Timeout
37 * @icsk_retransmit_timer: Resend (no ack)
38 * @icsk_rto:		   Retransmit timeout
39 * @icsk_ca_ops		   Pluggable congestion control hook
40 * @icsk_ca_state:	   Congestion control state
41 * @icsk_retransmits:	   Number of unrecovered [RTO] timeouts
42 * @icsk_pending:	   Scheduled timer event
43 * @icsk_backoff:	   Backoff
44 * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
45 * @icsk_probes_out:	   unanswered 0 window probes
46 * @icsk_ack:		   Delayed ACK control data
47 */
48struct inet_connection_sock {
49	/* inet_sock has to be the first member! */
50	struct inet_sock	  icsk_inet;
51	struct request_sock_queue icsk_accept_queue;
52	struct inet_bind_bucket	  *icsk_bind_hash;
53	unsigned long		  icsk_timeout;
54 	struct timer_list	  icsk_retransmit_timer;
55 	struct timer_list	  icsk_delack_timer;
56	__u32			  icsk_rto;
57	struct tcp_congestion_ops *icsk_ca_ops;
58	__u8			  icsk_ca_state;
59	__u8			  icsk_retransmits;
60	__u8			  icsk_pending;
61	__u8			  icsk_backoff;
62	__u8			  icsk_syn_retries;
63	__u8			  icsk_probes_out;
64	/* 2 BYTES HOLE, TRY TO PACK! */
65	struct {
66		__u8		  pending;	 /* ACK is pending			   */
67		__u8		  quick;	 /* Scheduled number of quick acks	   */
68		__u8		  pingpong;	 /* The session is interactive		   */
69		__u8		  blocked;	 /* Delayed ACK was blocked by socket lock */
70		__u32		  ato;		 /* Predicted tick of soft clock	   */
71		unsigned long	  timeout;	 /* Currently scheduled timeout		   */
72		__u32		  lrcvtime;	 /* timestamp of last received data packet */
73		__u16		  last_seg_size; /* Size of last incoming segment	   */
74		__u16		  rcv_mss;	 /* MSS used for delayed ACK decisions	   */
75	} icsk_ack;
76	u32			  icsk_ca_priv[16];
77#define ICSK_CA_PRIV_SIZE	(16 * sizeof(u32))
78};
79
80#define ICSK_TIME_RETRANS	1	/* Retransmit timer */
81#define ICSK_TIME_DACK		2	/* Delayed ack timer */
82#define ICSK_TIME_PROBE0	3	/* Zero window probe timer */
83#define ICSK_TIME_KEEPOPEN	4	/* Keepalive timer */
84
85static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
86{
87	return (struct inet_connection_sock *)sk;
88}
89
90static inline void *inet_csk_ca(const struct sock *sk)
91{
92	return (void *)inet_csk(sk)->icsk_ca_priv;
93}
94
95extern struct sock *inet_csk_clone(struct sock *sk,
96				   const struct request_sock *req,
97				   const unsigned int __nocast priority);
98
99enum inet_csk_ack_state_t {
100	ICSK_ACK_SCHED	= 1,
101	ICSK_ACK_TIMER  = 2,
102	ICSK_ACK_PUSHED = 4
103};
104
105extern void inet_csk_init_xmit_timers(struct sock *sk,
106				      void (*retransmit_handler)(unsigned long),
107				      void (*delack_handler)(unsigned long),
108				      void (*keepalive_handler)(unsigned long));
109extern void inet_csk_clear_xmit_timers(struct sock *sk);
110
111static inline void inet_csk_schedule_ack(struct sock *sk)
112{
113	inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
114}
115
116static inline int inet_csk_ack_scheduled(const struct sock *sk)
117{
118	return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
119}
120
121static inline void inet_csk_delack_init(struct sock *sk)
122{
123	memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
124}
125
126extern void inet_csk_delete_keepalive_timer(struct sock *sk);
127extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
128
129#ifdef INET_CSK_DEBUG
130extern const char inet_csk_timer_bug_msg[];
131#endif
132
133static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
134{
135	struct inet_connection_sock *icsk = inet_csk(sk);
136
137	if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
138		icsk->icsk_pending = 0;
139#ifdef INET_CSK_CLEAR_TIMERS
140		sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
141#endif
142	} else if (what == ICSK_TIME_DACK) {
143		icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
144#ifdef INET_CSK_CLEAR_TIMERS
145		sk_stop_timer(sk, &icsk->icsk_delack_timer);
146#endif
147	}
148#ifdef INET_CSK_DEBUG
149	else {
150		pr_debug("%s", inet_csk_timer_bug_msg);
151	}
152#endif
153}
154
155/*
156 *	Reset the retransmission timer
157 */
158static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
159					     unsigned long when,
160					     const unsigned long max_when)
161{
162	struct inet_connection_sock *icsk = inet_csk(sk);
163
164	if (when > max_when) {
165#ifdef INET_CSK_DEBUG
166		pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
167			 sk, what, when, current_text_addr());
168#endif
169		when = max_when;
170	}
171
172	if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
173		icsk->icsk_pending = what;
174		icsk->icsk_timeout = jiffies + when;
175		sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
176	} else if (what == ICSK_TIME_DACK) {
177		icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
178		icsk->icsk_ack.timeout = jiffies + when;
179		sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
180	}
181#ifdef INET_CSK_DEBUG
182	else {
183		pr_debug("%s", inet_csk_timer_bug_msg);
184	}
185#endif
186}
187
188extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
189
190extern struct request_sock *inet_csk_search_req(const struct sock *sk,
191						struct request_sock ***prevp,
192						const __u16 rport,
193						const __u32 raddr,
194						const __u32 laddr);
195extern int inet_csk_get_port(struct inet_hashinfo *hashinfo,
196			     struct sock *sk, unsigned short snum);
197
198extern struct dst_entry* inet_csk_route_req(struct sock *sk,
199					    const struct request_sock *req);
200
201static inline void inet_csk_reqsk_queue_add(struct sock *sk,
202					    struct request_sock *req,
203					    struct sock *child)
204{
205	reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
206}
207
208extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
209					  struct request_sock *req,
210					  const unsigned timeout);
211
212static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
213						struct request_sock *req)
214{
215	if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
216		inet_csk_delete_keepalive_timer(sk);
217}
218
219static inline void inet_csk_reqsk_queue_added(struct sock *sk,
220					      const unsigned long timeout)
221{
222	if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
223		inet_csk_reset_keepalive_timer(sk, timeout);
224}
225
226static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
227{
228	return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
229}
230
231static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
232{
233	return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
234}
235
236static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
237{
238	return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
239}
240
241static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
242					       struct request_sock *req,
243					       struct request_sock **prev)
244{
245	reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
246}
247
248static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
249					     struct request_sock *req,
250					     struct request_sock **prev)
251{
252	inet_csk_reqsk_queue_unlink(sk, req, prev);
253	inet_csk_reqsk_queue_removed(sk, req);
254	reqsk_free(req);
255}
256
257extern void inet_csk_reqsk_queue_prune(struct sock *parent,
258				       const unsigned long interval,
259				       const unsigned long timeout,
260				       const unsigned long max_rto);
261
262extern void inet_csk_destroy_sock(struct sock *sk);
263
264/*
265 * LISTEN is a special case for poll..
266 */
267static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
268{
269	return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
270			(POLLIN | POLLRDNORM) : 0;
271}
272
273extern int  inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
274extern void inet_csk_listen_stop(struct sock *sk);
275
276#endif /* _INET_CONNECTION_SOCK_H */
277