inet_connection_sock.h revision ab1e0a13d70299e792fd0527cefd070c1405fa5b
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/string.h>
20#include <linux/timer.h>
21#include <linux/poll.h>
22
23#include <net/inet_sock.h>
24#include <net/request_sock.h>
25
26#define INET_CSK_DEBUG 1
27
28/* Cancel timers, when they are not required. */
29#undef INET_CSK_CLEAR_TIMERS
30
31struct inet_bind_bucket;
32struct tcp_congestion_ops;
33
34/*
35 * Pointers to address related TCP functions
36 * (i.e. things that depend on the address family)
37 */
38struct inet_connection_sock_af_ops {
39	int	    (*queue_xmit)(struct sk_buff *skb, int ipfragok);
40	void	    (*send_check)(struct sock *sk, int len,
41				  struct sk_buff *skb);
42	int	    (*rebuild_header)(struct sock *sk);
43	int	    (*conn_request)(struct sock *sk, struct sk_buff *skb);
44	struct sock *(*syn_recv_sock)(struct sock *sk, struct sk_buff *skb,
45				      struct request_sock *req,
46				      struct dst_entry *dst);
47	int	    (*remember_stamp)(struct sock *sk);
48	u16	    net_header_len;
49	u16	    sockaddr_len;
50	int	    (*setsockopt)(struct sock *sk, int level, int optname,
51				  char __user *optval, int optlen);
52	int	    (*getsockopt)(struct sock *sk, int level, int optname,
53				  char __user *optval, int __user *optlen);
54	int	    (*compat_setsockopt)(struct sock *sk,
55				int level, int optname,
56				char __user *optval, int optlen);
57	int	    (*compat_getsockopt)(struct sock *sk,
58				int level, int optname,
59				char __user *optval, int __user *optlen);
60	void	    (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
61	int	    (*bind_conflict)(const struct sock *sk,
62				     const struct inet_bind_bucket *tb);
63};
64
65/** inet_connection_sock - INET connection oriented sock
66 *
67 * @icsk_accept_queue:	   FIFO of established children
68 * @icsk_bind_hash:	   Bind node
69 * @icsk_timeout:	   Timeout
70 * @icsk_retransmit_timer: Resend (no ack)
71 * @icsk_rto:		   Retransmit timeout
72 * @icsk_pmtu_cookie	   Last pmtu seen by socket
73 * @icsk_ca_ops		   Pluggable congestion control hook
74 * @icsk_af_ops		   Operations which are AF_INET{4,6} specific
75 * @icsk_ca_state:	   Congestion control state
76 * @icsk_retransmits:	   Number of unrecovered [RTO] timeouts
77 * @icsk_pending:	   Scheduled timer event
78 * @icsk_backoff:	   Backoff
79 * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
80 * @icsk_probes_out:	   unanswered 0 window probes
81 * @icsk_ext_hdr_len:	   Network protocol overhead (IP/IPv6 options)
82 * @icsk_ack:		   Delayed ACK control data
83 * @icsk_mtup;		   MTU probing control data
84 */
85struct inet_connection_sock {
86	/* inet_sock has to be the first member! */
87	struct inet_sock	  icsk_inet;
88	struct request_sock_queue icsk_accept_queue;
89	struct inet_bind_bucket	  *icsk_bind_hash;
90	unsigned long		  icsk_timeout;
91 	struct timer_list	  icsk_retransmit_timer;
92 	struct timer_list	  icsk_delack_timer;
93	__u32			  icsk_rto;
94	__u32			  icsk_pmtu_cookie;
95	const struct tcp_congestion_ops *icsk_ca_ops;
96	const struct inet_connection_sock_af_ops *icsk_af_ops;
97	unsigned int		  (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
98	__u8			  icsk_ca_state;
99	__u8			  icsk_retransmits;
100	__u8			  icsk_pending;
101	__u8			  icsk_backoff;
102	__u8			  icsk_syn_retries;
103	__u8			  icsk_probes_out;
104	__u16			  icsk_ext_hdr_len;
105	struct {
106		__u8		  pending;	 /* ACK is pending			   */
107		__u8		  quick;	 /* Scheduled number of quick acks	   */
108		__u8		  pingpong;	 /* The session is interactive		   */
109		__u8		  blocked;	 /* Delayed ACK was blocked by socket lock */
110		__u32		  ato;		 /* Predicted tick of soft clock	   */
111		unsigned long	  timeout;	 /* Currently scheduled timeout		   */
112		__u32		  lrcvtime;	 /* timestamp of last received data packet */
113		__u16		  last_seg_size; /* Size of last incoming segment	   */
114		__u16		  rcv_mss;	 /* MSS used for delayed ACK decisions	   */
115	} icsk_ack;
116	struct {
117		int		  enabled;
118
119		/* Range of MTUs to search */
120		int		  search_high;
121		int		  search_low;
122
123		/* Information on the current probe. */
124		int		  probe_size;
125	} icsk_mtup;
126	u32			  icsk_ca_priv[16];
127#define ICSK_CA_PRIV_SIZE	(16 * sizeof(u32))
128};
129
130#define ICSK_TIME_RETRANS	1	/* Retransmit timer */
131#define ICSK_TIME_DACK		2	/* Delayed ack timer */
132#define ICSK_TIME_PROBE0	3	/* Zero window probe timer */
133#define ICSK_TIME_KEEPOPEN	4	/* Keepalive timer */
134
135static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
136{
137	return (struct inet_connection_sock *)sk;
138}
139
140static inline void *inet_csk_ca(const struct sock *sk)
141{
142	return (void *)inet_csk(sk)->icsk_ca_priv;
143}
144
145extern struct sock *inet_csk_clone(struct sock *sk,
146				   const struct request_sock *req,
147				   const gfp_t priority);
148
149enum inet_csk_ack_state_t {
150	ICSK_ACK_SCHED	= 1,
151	ICSK_ACK_TIMER  = 2,
152	ICSK_ACK_PUSHED = 4,
153	ICSK_ACK_PUSHED2 = 8
154};
155
156extern void inet_csk_init_xmit_timers(struct sock *sk,
157				      void (*retransmit_handler)(unsigned long),
158				      void (*delack_handler)(unsigned long),
159				      void (*keepalive_handler)(unsigned long));
160extern void inet_csk_clear_xmit_timers(struct sock *sk);
161
162static inline void inet_csk_schedule_ack(struct sock *sk)
163{
164	inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
165}
166
167static inline int inet_csk_ack_scheduled(const struct sock *sk)
168{
169	return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
170}
171
172static inline void inet_csk_delack_init(struct sock *sk)
173{
174	memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
175}
176
177extern void inet_csk_delete_keepalive_timer(struct sock *sk);
178extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
179
180#ifdef INET_CSK_DEBUG
181extern const char inet_csk_timer_bug_msg[];
182#endif
183
184static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
185{
186	struct inet_connection_sock *icsk = inet_csk(sk);
187
188	if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
189		icsk->icsk_pending = 0;
190#ifdef INET_CSK_CLEAR_TIMERS
191		sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
192#endif
193	} else if (what == ICSK_TIME_DACK) {
194		icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
195#ifdef INET_CSK_CLEAR_TIMERS
196		sk_stop_timer(sk, &icsk->icsk_delack_timer);
197#endif
198	}
199#ifdef INET_CSK_DEBUG
200	else {
201		pr_debug("%s", inet_csk_timer_bug_msg);
202	}
203#endif
204}
205
206/*
207 *	Reset the retransmission timer
208 */
209static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
210					     unsigned long when,
211					     const unsigned long max_when)
212{
213	struct inet_connection_sock *icsk = inet_csk(sk);
214
215	if (when > max_when) {
216#ifdef INET_CSK_DEBUG
217		pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
218			 sk, what, when, current_text_addr());
219#endif
220		when = max_when;
221	}
222
223	if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
224		icsk->icsk_pending = what;
225		icsk->icsk_timeout = jiffies + when;
226		sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
227	} else if (what == ICSK_TIME_DACK) {
228		icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
229		icsk->icsk_ack.timeout = jiffies + when;
230		sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
231	}
232#ifdef INET_CSK_DEBUG
233	else {
234		pr_debug("%s", inet_csk_timer_bug_msg);
235	}
236#endif
237}
238
239extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
240
241extern struct request_sock *inet_csk_search_req(const struct sock *sk,
242						struct request_sock ***prevp,
243						const __be16 rport,
244						const __be32 raddr,
245						const __be32 laddr);
246extern int inet_csk_bind_conflict(const struct sock *sk,
247				  const struct inet_bind_bucket *tb);
248extern int inet_csk_get_port(struct sock *sk, unsigned short snum);
249
250extern struct dst_entry* inet_csk_route_req(struct sock *sk,
251					    const struct request_sock *req);
252
253static inline void inet_csk_reqsk_queue_add(struct sock *sk,
254					    struct request_sock *req,
255					    struct sock *child)
256{
257	reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
258}
259
260extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
261					  struct request_sock *req,
262					  unsigned long timeout);
263
264static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
265						struct request_sock *req)
266{
267	if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
268		inet_csk_delete_keepalive_timer(sk);
269}
270
271static inline void inet_csk_reqsk_queue_added(struct sock *sk,
272					      const unsigned long timeout)
273{
274	if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
275		inet_csk_reset_keepalive_timer(sk, timeout);
276}
277
278static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
279{
280	return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
281}
282
283static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
284{
285	return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
286}
287
288static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
289{
290	return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
291}
292
293static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
294					       struct request_sock *req,
295					       struct request_sock **prev)
296{
297	reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
298}
299
300static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
301					     struct request_sock *req,
302					     struct request_sock **prev)
303{
304	inet_csk_reqsk_queue_unlink(sk, req, prev);
305	inet_csk_reqsk_queue_removed(sk, req);
306	reqsk_free(req);
307}
308
309extern void inet_csk_reqsk_queue_prune(struct sock *parent,
310				       const unsigned long interval,
311				       const unsigned long timeout,
312				       const unsigned long max_rto);
313
314extern void inet_csk_destroy_sock(struct sock *sk);
315
316/*
317 * LISTEN is a special case for poll..
318 */
319static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
320{
321	return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
322			(POLLIN | POLLRDNORM) : 0;
323}
324
325extern int  inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
326extern void inet_csk_listen_stop(struct sock *sk);
327
328extern void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
329
330extern int inet_csk_ctl_sock_create(struct socket **sock,
331				    unsigned short family,
332				    unsigned short type,
333				    unsigned char protocol);
334
335extern int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
336				      char __user *optval, int __user *optlen);
337extern int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
338				      char __user *optval, int optlen);
339#endif /* _INET_CONNECTION_SOCK_H */
340