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/*
* 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 1.7 1997/09/17 18:50:26 freitag 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)
{
unsigned long flags;
save_flags (flags);
cli();
t->timeout = 0;
del_timer (&t->timer);
restore_flags (flags);
}
void net_reset_timer (struct sock *t, int timeout, unsigned long len)
{
net_delete_timer (t);
t->timeout = timeout;
#if 1
/* FIXME: ??? */
if ((int) len < 0) /* prevent close to infinite timers. THEY _DO_ */
len = 3; /* happen (negative values ?) - don't ask me why ! -FB */
#endif
t->timer.expires = jiffies+len;
add_timer (&t->timer);
}
/*
* 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 (sk->sock_readers)
{
sk->timer.expires = jiffies+HZ;
add_timer(&sk->timer);
sti();
return;
}
/* Always see if we need to send an ack. */
if (sk->ack_backlog && !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. */
sk->state = TCP_CLOSE;
net_delete_timer (sk);
if (!sk->dead)
sk->state_change(sk);
sk->shutdown = SHUTDOWN_MASK;
net_reset_timer (sk, TIME_DONE, TCP_DONE_TIME);
break;
default:
printk (KERN_DEBUG "net_timer: timer expired - reason %d is unknown\n", why);
break;
}
}
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