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 sock *sk, struct sk_buff *skb, struct flowi *fl);
40	void	    (*send_check)(struct sock *sk, struct sk_buff *skb);
41	int	    (*rebuild_header)(struct sock *sk);
42	void	    (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb);
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	u16	    net_header_len;
48	u16	    net_frag_header_len;
49	u16	    sockaddr_len;
50	int	    (*setsockopt)(struct sock *sk, int level, int optname,
51				  char __user *optval, unsigned int optlen);
52	int	    (*getsockopt)(struct sock *sk, int level, int optname,
53				  char __user *optval, int __user *optlen);
54#ifdef CONFIG_COMPAT
55	int	    (*compat_setsockopt)(struct sock *sk,
56				int level, int optname,
57				char __user *optval, unsigned int optlen);
58	int	    (*compat_getsockopt)(struct sock *sk,
59				int level, int optname,
60				char __user *optval, int __user *optlen);
61#endif
62	void	    (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
63	int	    (*bind_conflict)(const struct sock *sk,
64				     const struct inet_bind_bucket *tb, bool relax);
65	void	    (*mtu_reduced)(struct sock *sk);
66};
67
68/** inet_connection_sock - INET connection oriented sock
69 *
70 * @icsk_accept_queue:	   FIFO of established children
71 * @icsk_bind_hash:	   Bind node
72 * @icsk_timeout:	   Timeout
73 * @icsk_retransmit_timer: Resend (no ack)
74 * @icsk_rto:		   Retransmit timeout
75 * @icsk_pmtu_cookie	   Last pmtu seen by socket
76 * @icsk_ca_ops		   Pluggable congestion control hook
77 * @icsk_af_ops		   Operations which are AF_INET{4,6} specific
78 * @icsk_ca_state:	   Congestion control state
79 * @icsk_retransmits:	   Number of unrecovered [RTO] timeouts
80 * @icsk_pending:	   Scheduled timer event
81 * @icsk_backoff:	   Backoff
82 * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
83 * @icsk_probes_out:	   unanswered 0 window probes
84 * @icsk_ext_hdr_len:	   Network protocol overhead (IP/IPv6 options)
85 * @icsk_ack:		   Delayed ACK control data
86 * @icsk_mtup;		   MTU probing control data
87 */
88struct inet_connection_sock {
89	/* inet_sock has to be the first member! */
90	struct inet_sock	  icsk_inet;
91	struct request_sock_queue icsk_accept_queue;
92	struct inet_bind_bucket	  *icsk_bind_hash;
93	unsigned long		  icsk_timeout;
94 	struct timer_list	  icsk_retransmit_timer;
95 	struct timer_list	  icsk_delack_timer;
96	__u32			  icsk_rto;
97	__u32			  icsk_pmtu_cookie;
98	const struct tcp_congestion_ops *icsk_ca_ops;
99	const struct inet_connection_sock_af_ops *icsk_af_ops;
100	unsigned int		  (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
101	__u8			  icsk_ca_state:6,
102				  icsk_ca_setsockopt:1,
103				  icsk_ca_dst_locked:1;
104	__u8			  icsk_retransmits;
105	__u8			  icsk_pending;
106	__u8			  icsk_backoff;
107	__u8			  icsk_syn_retries;
108	__u8			  icsk_probes_out;
109	__u16			  icsk_ext_hdr_len;
110	struct {
111		__u8		  pending;	 /* ACK is pending			   */
112		__u8		  quick;	 /* Scheduled number of quick acks	   */
113		__u8		  pingpong;	 /* The session is interactive		   */
114		__u8		  blocked;	 /* Delayed ACK was blocked by socket lock */
115		__u32		  ato;		 /* Predicted tick of soft clock	   */
116		unsigned long	  timeout;	 /* Currently scheduled timeout		   */
117		__u32		  lrcvtime;	 /* timestamp of last received data packet */
118		__u16		  last_seg_size; /* Size of last incoming segment	   */
119		__u16		  rcv_mss;	 /* MSS used for delayed ACK decisions	   */
120	} icsk_ack;
121	struct {
122		int		  enabled;
123
124		/* Range of MTUs to search */
125		int		  search_high;
126		int		  search_low;
127
128		/* Information on the current probe. */
129		int		  probe_size;
130
131		u32		  probe_timestamp;
132	} icsk_mtup;
133	u32			  icsk_user_timeout;
134
135	u64			  icsk_ca_priv[64 / sizeof(u64)];
136#define ICSK_CA_PRIV_SIZE      (8 * sizeof(u64))
137};
138
139#define ICSK_TIME_RETRANS	1	/* Retransmit timer */
140#define ICSK_TIME_DACK		2	/* Delayed ack timer */
141#define ICSK_TIME_PROBE0	3	/* Zero window probe timer */
142#define ICSK_TIME_EARLY_RETRANS 4	/* Early retransmit timer */
143#define ICSK_TIME_LOSS_PROBE	5	/* Tail loss probe timer */
144
145static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
146{
147	return (struct inet_connection_sock *)sk;
148}
149
150static inline void *inet_csk_ca(const struct sock *sk)
151{
152	return (void *)inet_csk(sk)->icsk_ca_priv;
153}
154
155struct sock *inet_csk_clone_lock(const struct sock *sk,
156				 const struct request_sock *req,
157				 const gfp_t priority);
158
159enum inet_csk_ack_state_t {
160	ICSK_ACK_SCHED	= 1,
161	ICSK_ACK_TIMER  = 2,
162	ICSK_ACK_PUSHED = 4,
163	ICSK_ACK_PUSHED2 = 8
164};
165
166void inet_csk_init_xmit_timers(struct sock *sk,
167			       void (*retransmit_handler)(unsigned long),
168			       void (*delack_handler)(unsigned long),
169			       void (*keepalive_handler)(unsigned long));
170void inet_csk_clear_xmit_timers(struct sock *sk);
171
172static inline void inet_csk_schedule_ack(struct sock *sk)
173{
174	inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
175}
176
177static inline int inet_csk_ack_scheduled(const struct sock *sk)
178{
179	return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
180}
181
182static inline void inet_csk_delack_init(struct sock *sk)
183{
184	memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
185}
186
187void inet_csk_delete_keepalive_timer(struct sock *sk);
188void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
189
190#ifdef INET_CSK_DEBUG
191extern const char inet_csk_timer_bug_msg[];
192#endif
193
194static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
195{
196	struct inet_connection_sock *icsk = inet_csk(sk);
197
198	if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
199		icsk->icsk_pending = 0;
200#ifdef INET_CSK_CLEAR_TIMERS
201		sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
202#endif
203	} else if (what == ICSK_TIME_DACK) {
204		icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
205#ifdef INET_CSK_CLEAR_TIMERS
206		sk_stop_timer(sk, &icsk->icsk_delack_timer);
207#endif
208	}
209#ifdef INET_CSK_DEBUG
210	else {
211		pr_debug("%s", inet_csk_timer_bug_msg);
212	}
213#endif
214}
215
216/*
217 *	Reset the retransmission timer
218 */
219static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
220					     unsigned long when,
221					     const unsigned long max_when)
222{
223	struct inet_connection_sock *icsk = inet_csk(sk);
224
225	if (when > max_when) {
226#ifdef INET_CSK_DEBUG
227		pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
228			 sk, what, when, current_text_addr());
229#endif
230		when = max_when;
231	}
232
233	if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
234	    what == ICSK_TIME_EARLY_RETRANS || what ==  ICSK_TIME_LOSS_PROBE) {
235		icsk->icsk_pending = what;
236		icsk->icsk_timeout = jiffies + when;
237		sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
238	} else if (what == ICSK_TIME_DACK) {
239		icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
240		icsk->icsk_ack.timeout = jiffies + when;
241		sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
242	}
243#ifdef INET_CSK_DEBUG
244	else {
245		pr_debug("%s", inet_csk_timer_bug_msg);
246	}
247#endif
248}
249
250static inline unsigned long
251inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
252		     unsigned long max_when)
253{
254        u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
255
256        return (unsigned long)min_t(u64, when, max_when);
257}
258
259struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
260
261struct request_sock *inet_csk_search_req(struct sock *sk,
262					 const __be16 rport,
263					 const __be32 raddr,
264					 const __be32 laddr);
265int inet_csk_bind_conflict(const struct sock *sk,
266			   const struct inet_bind_bucket *tb, bool relax);
267int inet_csk_get_port(struct sock *sk, unsigned short snum);
268
269struct dst_entry *inet_csk_route_req(struct sock *sk, struct flowi4 *fl4,
270				     const struct request_sock *req);
271struct dst_entry *inet_csk_route_child_sock(struct sock *sk, struct sock *newsk,
272					    const struct request_sock *req);
273
274static inline void inet_csk_reqsk_queue_add(struct sock *sk,
275					    struct request_sock *req,
276					    struct sock *child)
277{
278	reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
279}
280
281void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
282				   unsigned long timeout);
283
284static inline void inet_csk_reqsk_queue_added(struct sock *sk,
285					      const unsigned long timeout)
286{
287	reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
288}
289
290static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
291{
292	return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
293}
294
295static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
296{
297	return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
298}
299
300static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
301{
302	return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
303}
304
305void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
306
307void inet_csk_destroy_sock(struct sock *sk);
308void inet_csk_prepare_forced_close(struct sock *sk);
309
310/*
311 * LISTEN is a special case for poll..
312 */
313static inline unsigned int inet_csk_listen_poll(const struct sock *sk)
314{
315	return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
316			(POLLIN | POLLRDNORM) : 0;
317}
318
319int inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
320void inet_csk_listen_stop(struct sock *sk);
321
322void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
323
324int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
325			       char __user *optval, int __user *optlen);
326int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
327			       char __user *optval, unsigned int optlen);
328
329struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
330#endif /* _INET_CONNECTION_SOCK_H */
331