1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
|
/*
* NET Generic infrastructure for INET connection oriented protocols.
*
* Definitions for inet_connection_sock
*
* Authors: Many people, see the TCP sources
*
* From code originally in TCP
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _INET_CONNECTION_SOCK_H
#define _INET_CONNECTION_SOCK_H
#include <linux/ip.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <net/request_sock.h>
#define INET_CSK_DEBUG 1
/* Cancel timers, when they are not required. */
#undef INET_CSK_CLEAR_TIMERS
struct inet_bind_bucket;
struct inet_hashinfo;
/** inet_connection_sock - INET connection oriented sock
*
* @icsk_accept_queue: FIFO of established children
* @icsk_bind_hash: Bind node
* @icsk_timeout: Timeout
* @icsk_retransmit_timer: Resend (no ack)
* @icsk_rto: Retransmit timeout
* @icsk_retransmits: Number of unrecovered [RTO] timeouts
* @icsk_pending: Scheduled timer event
* @icsk_backoff: Backoff
* @icsk_syn_retries: Number of allowed SYN (or equivalent) retries
* @icsk_ack: Delayed ACK control data
*/
struct inet_connection_sock {
/* inet_sock has to be the first member! */
struct inet_sock icsk_inet;
struct request_sock_queue icsk_accept_queue;
struct inet_bind_bucket *icsk_bind_hash;
unsigned long icsk_timeout;
struct timer_list icsk_retransmit_timer;
struct timer_list icsk_delack_timer;
__u32 icsk_rto;
__u8 icsk_retransmits;
__u8 icsk_pending;
__u8 icsk_backoff;
__u8 icsk_syn_retries;
struct {
__u8 pending; /* ACK is pending */
__u8 quick; /* Scheduled number of quick acks */
__u8 pingpong; /* The session is interactive */
__u8 blocked; /* Delayed ACK was blocked by socket lock */
__u32 ato; /* Predicted tick of soft clock */
unsigned long timeout; /* Currently scheduled timeout */
__u32 lrcvtime; /* timestamp of last received data packet */
__u16 last_seg_size; /* Size of last incoming segment */
__u16 rcv_mss; /* MSS used for delayed ACK decisions */
} icsk_ack;
};
#define ICSK_TIME_RETRANS 1 /* Retransmit timer */
#define ICSK_TIME_DACK 2 /* Delayed ack timer */
#define ICSK_TIME_PROBE0 3 /* Zero window probe timer */
#define ICSK_TIME_KEEPOPEN 4 /* Keepalive timer */
static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
{
return (struct inet_connection_sock *)sk;
}
extern struct sock *inet_csk_clone(struct sock *sk,
const struct request_sock *req,
const unsigned int __nocast priority);
enum inet_csk_ack_state_t {
ICSK_ACK_SCHED = 1,
ICSK_ACK_TIMER = 2,
ICSK_ACK_PUSHED = 4
};
extern void inet_csk_init_xmit_timers(struct sock *sk,
void (*retransmit_handler)(unsigned long),
void (*delack_handler)(unsigned long),
void (*keepalive_handler)(unsigned long));
extern void inet_csk_clear_xmit_timers(struct sock *sk);
static inline void inet_csk_schedule_ack(struct sock *sk)
{
inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
}
static inline int inet_csk_ack_scheduled(const struct sock *sk)
{
return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
}
static inline void inet_csk_delack_init(struct sock *sk)
{
memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
}
extern void inet_csk_delete_keepalive_timer(struct sock *sk);
extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
#ifdef INET_CSK_DEBUG
extern const char inet_csk_timer_bug_msg[];
#endif
static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
{
struct inet_connection_sock *icsk = inet_csk(sk);
if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
icsk->icsk_pending = 0;
#ifdef INET_CSK_CLEAR_TIMERS
sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
#endif
} else if (what == ICSK_TIME_DACK) {
icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
#ifdef INET_CSK_CLEAR_TIMERS
sk_stop_timer(sk, &icsk->icsk_delack_timer);
#endif
}
#ifdef INET_CSK_DEBUG
else {
pr_debug(inet_csk_timer_bug_msg);
}
#endif
}
/*
* Reset the retransmission timer
*/
static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
unsigned long when,
const unsigned long max_when)
{
struct inet_connection_sock *icsk = inet_csk(sk);
if (when > max_when) {
#ifdef INET_CSK_DEBUG
pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
sk, what, when, current_text_addr());
#endif
when = max_when;
}
if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
icsk->icsk_pending = what;
icsk->icsk_timeout = jiffies + when;
sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
} else if (what == ICSK_TIME_DACK) {
icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
icsk->icsk_ack.timeout = jiffies + when;
sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
}
#ifdef INET_CSK_DEBUG
else {
pr_debug(inet_csk_timer_bug_msg);
}
#endif
}
extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err);
extern struct request_sock *inet_csk_search_req(const struct sock *sk,
struct request_sock ***prevp,
const __u16 rport,
const __u32 raddr,
const __u32 laddr);
extern int inet_csk_get_port(struct inet_hashinfo *hashinfo,
struct sock *sk, unsigned short snum);
extern struct dst_entry* inet_csk_route_req(struct sock *sk,
const struct request_sock *req);
static inline void inet_csk_reqsk_queue_add(struct sock *sk,
struct request_sock *req,
struct sock *child)
{
reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
}
extern void inet_csk_reqsk_queue_hash_add(struct sock *sk,
struct request_sock *req,
const unsigned timeout);
static inline void inet_csk_reqsk_queue_removed(struct sock *sk,
struct request_sock *req)
{
if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0)
inet_csk_delete_keepalive_timer(sk);
}
static inline void inet_csk_reqsk_queue_added(struct sock *sk,
const unsigned long timeout)
{
if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0)
inet_csk_reset_keepalive_timer(sk, timeout);
}
static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
{
return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
}
static inline int inet_csk_reqsk_queue_young(const struct sock *sk)
{
return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue);
}
static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
{
return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue);
}
static inline void inet_csk_reqsk_queue_unlink(struct sock *sk,
struct request_sock *req,
struct request_sock **prev)
{
reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev);
}
static inline void inet_csk_reqsk_queue_drop(struct sock *sk,
struct request_sock *req,
struct request_sock **prev)
{
inet_csk_reqsk_queue_unlink(sk, req, prev);
inet_csk_reqsk_queue_removed(sk, req);
reqsk_free(req);
}
extern void inet_csk_reqsk_queue_prune(struct sock *parent,
const unsigned long interval,
const unsigned long timeout,
const unsigned long max_rto);
extern void inet_csk_destroy_sock(struct sock *sk);
extern int inet_csk_listen_start(struct sock *sk, const int nr_table_entries);
extern void inet_csk_listen_stop(struct sock *sk);
#endif /* _INET_CONNECTION_SOCK_H */
|
