From a81cd86c8d93236ffccfbee44b5818ba21523463 Mon Sep 17 00:00:00 2001 From: "Michael I. Bushnell" Date: Wed, 12 Jul 1995 15:42:50 +0000 Subject: entered into RCS --- pfinet/linux-inet/timer.c | 264 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 264 insertions(+) create mode 100644 pfinet/linux-inet/timer.c (limited to 'pfinet/linux-inet/timer.c') diff --git a/pfinet/linux-inet/timer.c b/pfinet/linux-inet/timer.c new file mode 100644 index 00000000..4fbbc74b --- /dev/null +++ b/pfinet/linux-inet/timer.c @@ -0,0 +1,264 @@ +/* + * 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: @(#)timer.c 1.0.7 05/25/93 + * + * Authors: Ross Biro, + * Fred N. van Kempen, + * Corey Minyard + * Fred Baumgarten, + * Florian La Roche, + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "ip.h" +#include "protocol.h" +#include "tcp.h" +#include +#include "sock.h" +#include "arp.h" + +void delete_timer (struct sock *t) +{ + unsigned long flags; + + save_flags (flags); + cli(); + + t->timeout = 0; + del_timer (&t->timer); + + restore_flags (flags); +} + +void reset_timer (struct sock *t, int timeout, unsigned long len) +{ + 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 = 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 + */ + + cli(); + if (sk->inuse || in_bh) + { + sk->timer.expires = 10; + add_timer(&sk->timer); + sti(); + return; + } + + sk->inuse = 1; + sti(); + + /* 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 (! sk->dead || sk->state != TCP_CLOSE) + { + printk ("non dead socket in time_done\n"); + release_sock (sk); + 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. + */ + if(sk->wmem_alloc!=0 || sk->rmem_alloc!=0) + { + sk->wmem_alloc++; /* So it DOESN'T go away */ + destroy_sock (sk); + sk->wmem_alloc--; /* Might now have hit 0 - fall through and do it again if so */ + sk->inuse = 0; /* This will be ok, the destroy won't totally work */ + } + if(sk->wmem_alloc==0 && sk->rmem_alloc==0) + destroy_sock(sk); /* Socket gone, DON'T update sk->inuse! */ + break; + case TIME_CLOSE: + /* We've waited long enough, close the socket. */ + sk->state = TCP_CLOSE; + delete_timer (sk); + /* Kill the ARP entry in case the hardware has changed. */ + arp_destroy (sk->daddr, 0); + if (!sk->dead) + sk->state_change(sk); + sk->shutdown = SHUTDOWN_MASK; + reset_timer (sk, TIME_DESTROY, TCP_DONE_TIME); + release_sock (sk); + break; +#if 0 + case TIME_PROBE0: + tcp_send_probe0(sk); + release_sock (sk); + break; + case TIME_WRITE: /* try to retransmit. */ + /* It could be we got here because we needed to send an ack. + * So we need to check for that. + */ + { + struct sk_buff *skb; + unsigned long flags; + + save_flags(flags); + cli(); + skb = sk->send_head; + if (!skb) + { + restore_flags(flags); + } + else + { + if (jiffies < skb->when + sk->rto) + { + reset_timer (sk, TIME_WRITE, skb->when + sk->rto - jiffies); + restore_flags(flags); + release_sock (sk); + break; + } + restore_flags(flags); + /* printk("timer: seq %d retrans %d out %d cong %d\n", sk->send_head->h.seq, + sk->retransmits, sk->packets_out, sk->cong_window); */ + sk->prot->retransmit (sk, 0); + if ((sk->state == TCP_ESTABLISHED && sk->retransmits && !(sk->retransmits & 7)) + || (sk->state != TCP_ESTABLISHED && sk->retransmits > TCP_RETR1)) + { + arp_destroy (sk->daddr, 0); + ip_route_check (sk->daddr); + } + if (sk->state != TCP_ESTABLISHED && sk->retransmits > TCP_RETR2) + { + sk->err = ETIMEDOUT; + if (sk->state == TCP_FIN_WAIT1 || sk->state == TCP_FIN_WAIT2 || sk->state == TCP_CLOSING) + { + sk->state = TCP_TIME_WAIT; + reset_timer (sk, TIME_CLOSE, TCP_TIMEWAIT_LEN); + } + else + { + sk->prot->close (sk, 1); + break; + } + } + } + release_sock (sk); + break; + } + case TIME_KEEPOPEN: + /* + * this reset_timer() call is a hack, this is not + * how KEEPOPEN is supposed to work. + */ + reset_timer (sk, TIME_KEEPOPEN, TCP_TIMEOUT_LEN); + + /* Send something to keep the connection open. */ + if (sk->prot->write_wakeup) + sk->prot->write_wakeup (sk); + sk->retransmits++; + if (sk->shutdown == SHUTDOWN_MASK) + { + sk->prot->close (sk, 1); + sk->state = TCP_CLOSE; + } + if ((sk->state == TCP_ESTABLISHED && sk->retransmits && !(sk->retransmits & 7)) + || (sk->state != TCP_ESTABLISHED && sk->retransmits > TCP_RETR1)) + { + arp_destroy (sk->daddr, 0); + ip_route_check (sk->daddr); + release_sock (sk); + break; + } + if (sk->state != TCP_ESTABLISHED && sk->retransmits > TCP_RETR2) + { + arp_destroy (sk->daddr, 0); + sk->err = ETIMEDOUT; + if (sk->state == TCP_FIN_WAIT1 || sk->state == TCP_FIN_WAIT2) + { + sk->state = TCP_TIME_WAIT; + if (!sk->dead) + sk->state_change(sk); + release_sock (sk); + } + else + { + sk->prot->close (sk, 1); + } + break; + } + release_sock (sk); + break; +#endif + default: + printk ("net_timer: timer expired - reason %d is unknown\n", why); + release_sock (sk); + break; + } +} + -- cgit v1.2.3