inet_connection_sock.h revision af05dc9394feb193d221bc9d4c6db768facb4b40
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/compiler.h>
19#include <linux/ip.h>
20#include <linux/string.h>
21#include <linux/timer.h>
22#include <net/request_sock.h>
23
24#define INET_CSK_DEBUG 1
25
26/* Cancel timers, when they are not required. */
27#undef INET_CSK_CLEAR_TIMERS
28
29struct inet_bind_bucket;
30struct inet_hashinfo;
31struct tcp_congestion_ops;
32
33/*
34 * Pointers to address related TCP functions
35 * (i.e. things that depend on the address family)
36 */
37struct inet_connection_sock_af_ops {
38	int	    (*queue_xmit)(struct sk_buff *skb, int ipfragok);
39	void	    (*send_check)(struct sock *sk, int len,
40				  struct sk_buff *skb);
41	int	    (*rebuild_header)(struct sock *sk);
42	int	    (*conn_request)(struct sock *sk, struct sk_buff *skb);
43	struct sock *(*syn_recv_sock)(struct sock *sk, struct sk_buff *skb,
44				      struct request_sock *req,
45				      struct dst_entry *dst);
46	int	    (*remember_stamp)(struct sock *sk);
47	__u16	    net_header_len;
48	int	    (*setsockopt)(struct sock *sk, int level, int optname,
49				  char __user *optval, int optlen);
50	int	    (*getsockopt)(struct sock *sk, int level, int optname,
51				  char __user *optval, int __user *optlen);
52	void	    (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
53	int sockaddr_len;
54};
55
56/** inet_connection_sock - INET connection oriented sock
57 *
58 * @icsk_accept_queue:	   FIFO of established children
59 * @icsk_bind_hash:	   Bind node
60 * @icsk_timeout:	   Timeout
61 * @icsk_retransmit_timer: Resend (no ack)
62 * @icsk_rto:		   Retransmit timeout
63 * @icsk_ca_ops		   Pluggable congestion control hook
64 * @icsk_af_ops		   Operations which are AF_INET{4,6} specific
65 * @icsk_ca_state:	   Congestion control state
66 * @icsk_retransmits:	   Number of unrecovered [RTO] timeouts
67 * @icsk_pending:	   Scheduled timer event
68 * @icsk_backoff:	   Backoff
69 * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
70 * @icsk_probes_out:	   unanswered 0 window probes
71 * @icsk_ack:		   Delayed ACK control data
72 */
73struct inet_connection_sock {
74	/* inet_sock has to be the first member! */
75	struct inet_sock	  icsk_inet;
76	struct request_sock_queue icsk_accept_queue;
77	struct inet_bind_bucket	  *icsk_bind_hash;
78	unsigned long		  icsk_timeout;
79 	struct timer_list	  icsk_retransmit_timer;
80 	struct timer_list	  icsk_delack_timer;
81	__u32			  icsk_rto;
82	struct tcp_congestion_ops *icsk_ca_ops;
83	struct inet_connection_sock_af_ops *icsk_af_ops;
84	__u8			  icsk_ca_state;
85	__u8			  icsk_retransmits;
86	__u8			  icsk_pending;
87	__u8			  icsk_backoff;
88	__u8			  icsk_syn_retries;
89	__u8			  icsk_probes_out;
90	/* 2 BYTES HOLE, TRY TO PACK! */
91	struct {
92		__u8		  pending;	 /* ACK is pending			   */
93		__u8		  quick;	 /* Scheduled number of quick acks	   */
94		__u8		  pingpong;	 /* The session is interactive		   */
95		__u8		  blocked;	 /* Delayed ACK was blocked by socket lock */
96		__u32		  ato;		 /* Predicted tick of soft clock	   */
97		unsigned long	  timeout;	 /* Currently scheduled timeout		   */
98		__u32		  lrcvtime;	 /* timestamp of last received data packet */
99		__u16		  last_seg_size; /* Size of last incoming segment	   */
100		__u16		  rcv_mss;	 /* MSS used for delayed ACK decisions	   */
101	} icsk_ack;
102	u32			  icsk_ca_priv[16];
103#define ICSK_CA_PRIV_SIZE	(16 * sizeof(u32))
104};
105
106#define ICSK_TIME_RETRANS	1	/* Retransmit timer */
107#define ICSK_TIME_DACK		2	/* Delayed ack timer */
108#define ICSK_TIME_PROBE0	3	/* Zero window probe timer */
109#define ICSK_TIME_KEEPOPEN	4	/* Keepalive timer */
110
111static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
112{
113	return (struct inet_connection_sock *)sk;
114}
115
116static inline void *inet_csk_ca(const struct sock *sk)
117{
118	return (void *)inet_csk(sk)->icsk_ca_priv;
119}
120
121extern struct sock *inet_csk_clone(struct sock *sk,
122				   const struct request_sock *req,
123				   const gfp_t priority);
124
125enum inet_csk_ack_state_t {
126	ICSK_ACK_SCHED	= 1,
127	ICSK_ACK_TIMER  = 2,
128	ICSK_ACK_PUSHED = 4
129};
130
131extern void inet_csk_init_xmit_timers(struct sock *sk,
132				      void (*retransmit_handler)(unsigned long),
133				      void (*delack_handler)(unsigned long),
134				      void (*keepalive_handler)(unsigned long));
135extern void inet_csk_clear_xmit_timers(struct sock *sk);
136
137static inline void inet_csk_schedule_ack(struct sock *sk)
138{
139	inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
140}
141
142static inline int inet_csk_ack_scheduled(const struct sock *sk)
143{
144	return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
145}
146
147static inline void inet_csk_delack_init(struct sock *sk)
148{
149	memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
150}
151
152extern void inet_csk_delete_keepalive_timer(struct sock *sk);
153extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
154
155#ifdef INET_CSK_DEBUG
156extern const char inet_csk_timer_bug_msg[];
157#endif
158
159static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
160{
161	struct inet_connection_sock *icsk = inet_csk(sk);
162
163	if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
164		icsk->icsk_pending = 0;
165#ifdef INET_CSK_CLEAR_TIMERS
166		sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
167#endif
168	} else if (what == ICSK_TIME_DACK) {
169		icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
170#ifdef INET_CSK_CLEAR_TIMERS
171		sk_stop_timer(sk, &icsk->icsk_delack_timer);
172#endif
173	}
174#ifdef INET_CSK_DEBUG
175	else {
176		pr_debug("%s", inet_csk_timer_bug_msg);
177	}
178#endif
179}
180
181/*
182 *	Reset the retransmission timer
183 */
184static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
185					     unsigned long when,
186					     const unsigned long max_when)
187{
188	struct inet_connection_sock *icsk = inet_csk(sk);
189
190	if (when > max_when) {
191#ifdef INET_CSK_DEBUG
192		pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
193			 sk, what, when, current_text_addr());
194#endif
195		when = max_when;
196	}
197
198	if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
199		icsk->icsk_pending = what;
200		icsk->icsk_timeout = jiffies + when;
201		sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
202	} else if (what == ICSK_TIME_DACK) {
203		icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
204		icsk->icsk_ack.timeout = jiffies + when;
205		sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
206	}
207#ifdef INET_CSK_DEBUG
208	else {
209		pr_debug("%s", inet_csk_timer_bug_msg);
210	}
211#endif
212}
213
214extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
215
216extern struct request_sock *inet_csk_search_req(const struct sock *sk,
217						struct request_sock ***prevp,
218						const __u16 rport,
219						const __u32 raddr,
220						const __u32 laddr);
221extern int inet_csk_bind_conflict(const struct sock *sk,
222				  const struct inet_bind_bucket *tb);
223extern int inet_csk_get_port(struct inet_hashinfo *hashinfo,
224			     struct sock *sk, unsigned short snum,
225			     int (*bind_conflict)(const struct sock *sk,
226						  const struct inet_bind_bucket *tb));
227
228extern struct dst_entry* inet_csk_route_req(struct sock *sk,
229					    const struct request_sock *req);
230
231static inline void inet_csk_reqsk_queue_add(struct sock *sk,
232					    struct request_sock *req,
233					    struct sock *child)
234{
235	reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
236}
237
238extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
239					  struct request_sock *req,
240					  unsigned long timeout);
241
242static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
243						struct request_sock *req)
244{
245	if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
246		inet_csk_delete_keepalive_timer(sk);
247}
248
249static inline void inet_csk_reqsk_queue_added(struct sock *sk,
250					      const unsigned long timeout)
251{
252	if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
253		inet_csk_reset_keepalive_timer(sk, timeout);
254}
255
256static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
257{
258	return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
259}
260
261static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
262{
263	return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
264}
265
266static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
267{
268	return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
269}
270
271static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
272					       struct request_sock *req,
273					       struct request_sock **prev)
274{
275	reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
276}
277
278static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
279					     struct request_sock *req,
280					     struct request_sock **prev)
281{
282	inet_csk_reqsk_queue_unlink(sk, req, prev);
283	inet_csk_reqsk_queue_removed(sk, req);
284	reqsk_free(req);
285}
286
287extern void inet_csk_reqsk_queue_prune(struct sock *parent,
288				       const unsigned long interval,
289				       const unsigned long timeout,
290				       const unsigned long max_rto);
291
292extern void inet_csk_destroy_sock(struct sock *sk);
293
294/*
295 * LISTEN is a special case for poll..
296 */
297static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
298{
299	return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
300			(POLLIN | POLLRDNORM) : 0;
301}
302
303extern int  inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
304extern void inet_csk_listen_stop(struct sock *sk);
305
306extern void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
307
308#endif /* _INET_CONNECTION_SOCK_H */
309