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
|
/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* TIMER - implementation of software timers for IP.
*
* Version: $Id: timer.c,v 1.15 1999/02/22 13:54:29 davem Exp $
*
* Authors: Ross Biro, <bir7@leland.Stanford.Edu>
* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
* Corey Minyard <wf-rch!minyard@relay.EU.net>
* Fred Baumgarten, <dc6iq@insu1.etec.uni-karlsruhe.de>
* Florian La Roche, <flla@stud.uni-sb.de>
*
* Fixes:
* Alan Cox : To avoid destroying a wait queue as we use it
* we defer destruction until the destroy timer goes
* off.
* Alan Cox : Destroy socket doesn't write a status value to the
* socket buffer _AFTER_ freeing it! Also sock ensures
* the socket will get removed BEFORE this is called
* otherwise if the timer TIME_DESTROY occurs inside
* of inet_bh() with this socket being handled it goes
* BOOM! Have to stop timer going off if net_bh is
* active or the destroy causes crashes.
* Alan Cox : Cleaned up unused code.
*
* 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.
*/
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <asm/system.h>
#include <linux/interrupt.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/tcp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/arp.h>
void net_delete_timer (struct sock *t)
{
if(t->timer.prev)
del_timer (&t->timer);
t->timeout = 0;
}
void net_reset_timer (struct sock *t, int timeout, unsigned long len)
{
t->timeout = timeout;
mod_timer(&t->timer, jiffies+len);
}
/* Now we will only be called whenever we need to do
* something, but we must be sure to process all of the
* sockets that need it.
*/
void net_timer (unsigned long data)
{
struct sock *sk = (struct sock*)data;
int why = sk->timeout;
/* Only process if socket is not in use. */
if (atomic_read(&sk->sock_readers)) {
/* Try again later. */
mod_timer(&sk->timer, jiffies+HZ/20);
return;
}
/* Always see if we need to send an ack. */
if (sk->tp_pinfo.af_tcp.delayed_acks && !sk->zapped) {
sk->prot->read_wakeup (sk);
if (!sk->dead)
sk->data_ready(sk,0);
}
/* Now we need to figure out why the socket was on the timer. */
switch (why) {
case TIME_DONE:
/* If the socket hasn't been closed off, re-try a bit later. */
if (!sk->dead) {
net_reset_timer(sk, TIME_DONE, TCP_DONE_TIME);
break;
}
if (sk->state != TCP_CLOSE) {
printk (KERN_DEBUG "non CLOSE socket in time_done\n");
break;
}
destroy_sock (sk);
break;
case TIME_DESTROY:
/* We've waited for a while for all the memory associated with
* the socket to be freed.
*/
destroy_sock(sk);
break;
case TIME_CLOSE:
/* We've waited long enough, close the socket. */
tcp_set_state(sk, TCP_CLOSE);
sk->shutdown = SHUTDOWN_MASK;
if (!sk->dead)
sk->state_change(sk);
net_reset_timer (sk, TIME_DONE, TCP_DONE_TIME);
break;
default:
/* I want to see these... */
printk ("net_timer: timer expired - reason %d is unknown\n", why);
break;
}
}
|
