/*
 *      Copyright (C) 2009 IBM Corp.
 *      This file is part of systemtap, and is free software.  You can
 *      redistribute it and/or modify it under the terms of the GNU General
 *      Public License (GPL); either version 2, or (at your option) any
 *      later version.
 *      
 *      Version 1.0     wilder@us.ibm.com     2009-07-06
 */

global DelayedACKs		/* LINUX_MIB_DELAYEDACKS */
global ListenOverflows		/* LINUX_MIB_LISTENOVERFLOWS */
global ListenDrops		/* LINUX_MIB_LISTENDROPS */
global TCPMemoryPressures	/* LINUX_MIB_TCPMEMORYPRESSURES */

/**
 * probe tcpmib.DelayedACKs - Count of delayed acks.
 * @sk: Pointer to the struct sock being acted on.
 * @op: Value to be added to the counter (Operation). 
 *
 * Counter Name: DelayedACKs
 * MIB: LINUX_MIB_DELAYEDACKS
 *
 */
global indelack_timer
probe linuxmib.DelayedACKs = _linuxmib.DelayedACKs.* {}

probe _linuxmib.DelayedACKs.A = kernel.function("tcp_send_ack")
{
	sk=$sk
	if ( !indelack_timer[sk] ) next
	op=1
	key = linuxmib_filter_key(sk,op);
	if ( key ) DelayedACKs[key] += op;
}

probe _linuxmib.DelayedACKs.B = kernel.function("tcp_delack_timer")
{
	sk=$data
	indelack_timer[sk]=1
}

probe _linuxmib.DelayedACKs.C = kernel.function("tcp_delack_timer").return
{
	sk=$data
	indelack_timer[sk]=0;
}

/**
 * probe tcpmib.ListenOverflows - Count of times a listen queue overflowed
 * @sk: Pointer to the struct sock being acted on.
 * @op: Value to be added to the counter (Operation). 
 *
 * Counter Name: ListenOverflows
 * MIB: LINUX_MIB_LISTENOVERFLOWS
 *
 */
probe linuxmib.ListenOverflows=kernel.function("tcp_v4_syn_recv_sock").return
{
	sk = $sk
	if ( $return ) next
	if ( $sk->sk_ack_backlog <= $sk->sk_max_ack_backlog ) next
	op = 1;
	key = linuxmib_filter_key(sk,op);
	if ( key ) ListenOverflows[key] += op;
}

/**
 * probe tcpmib.ListenDrops - Count of times conn request that were dropped.
 * @sk: Pointer to the struct sock being acted on.
 * @op: Value to be added to the counter (Operation). 
 *
 * Counter Name: ListenDrops
 * MIB: LINUX_MIB_LISTENDROPS
 *
 */
probe linuxmib.ListenDrops=kernel.function("tcp_v4_syn_recv_sock").return
{
	sk = $sk
	if ( $return ) next
	op = 1;
	key = linuxmib_filter_key(sk,op);
	if ( key ) ListenDrops[key] += op;
}

/**
 * probe tcpmib.TCPMemoryPressures - Count of times memory pressure was used.
 * @sk: Pointer to the struct sock being acted on.
 * @op: Value to be added to the counter (Operation). 
 *
 * Counter Name: TCPMemoryPressures
 * MIB: LINUX_MIB_TCPMEMORYPRESSURES
 *
 */
probe linuxmib.TCPMemoryPressures=kernel.function("tcp_enter_memory_pressure")
{
%( kernel_v >= "2.6.27" %?
	sk = $sk
%:
	sk = 0;
%)
	op = 1;
	if ( $tcp_memory_pressure ) next
	key = linuxmib_filter_key(sk,op);
        if ( key ) TCPMemoryPressures[key] += op;
}