#!/bin/sh
# SPDX-FileCopyrightText: 2024 Splunk, Inc.
# SPDX-License-Identifier: Apache-2.0

# shellcheck disable=SC1091
. "$(dirname "$0")"/common.sh

CMD='netstat -s'
HEADER='  IPdropped   TCPrexmits   TCPreorder   TCPpktRecv   TCPpktSent   UDPpktLost   UDPunkPort   UDPpktRecv   UDPpktSent'
HEADERIZE="BEGIN {print \"$HEADER\"}"
PRINTF='END {printf " %10d   %10d   %10d   %10d   %10d   %10d   %10d   %10d   %10d\n", IPdropped, TCPrexmits, TCPreorder, TCPpktRecv, TCPpktSent, UDPpktLost, UDPunkPort, UDPpktRecv, UDPpktSent}'

OS_FILE=/etc/os-release

if [ "$KERNEL" = "Linux" ] ; then
	if echo "$OS_ID" | grep -qi suse; then
		# shellcheck disable=SC2016
		CMD='nstat -az'
		# shellcheck disable=SC2016
		TCPreorder=0
		FIGURE_SECTION='/^IpOutDiscards/ {IPdropped=$2} /^TcpInSegs/ {TCPpktRecv=$2} /^TcpOutSegs/ {TCPpktSent=$2} /^TcpRetransSegs/ {TCPrexmits=$2} /^UdpInDatagrams/ {UDPpktRecv=$2} /^UdpNoPorts/ {UDPunkPort=$2} /^UdpInErrors/ {UDPpktLost=$2} /^UdpOutDatagrams/ {UDPpktSent=$2} /^.*Reorder/ {TCPreorder+=$2}'
	else
		# shellcheck disable=SC2016
		FIGURE_SECTION='/^Ip:$/ {inIP=1;inTCP=0;inUDP=0} /^Tcp(Ext)?:$/ {inIP=0;inTCP=1;inUDP=0} /^Udp:$/ {inIP=0;inTCP=0;inUDP=1} {if (NF==1 && $1 !~ /^Ip:$|^Udp:$|^Tcp(Ext)?:$/) inIP=inTCP=inUDP=0}'
		# shellcheck disable=SC2016
		SECTION_IP='inIP && /outgoing packets dropped/ {IPdropped=$1}'
		# shellcheck disable=SC2016
		SECTION_TCP='inTCP && /segments retransmited/ {TCPrexmits=$1} inTCP && /Detected reordering/ {TCPreorder=$3} inTCP && /[0-9] segments received$/ {TCPpktRecv=$1} inTCP && /segments send out/ {TCPpktSent=$1}'
		# shellcheck disable=SC2016
		SECTION_UDP='inUDP && /packets received/ {UDPpktRecv=$1} inUDP && /packets sent/ {UDPpktSent=$1} inUDP && /packet receive errors/ {UDPpktLost=$1} inUDP && /packets to unknown port received/ {UDPunkPort=$1}'
	fi
elif [ "$KERNEL" = "SunOS" ] ; then
	# shellcheck disable=SC2016
	COMMON='{gsub("=", "", $0)}'
	# shellcheck disable=SC2016
	SECTION_IP='/ipOutDiscards/ {IPdropped+=$2} /ipOutNoRoutes/ {IPdropped+=$4} /ipv6OutNoRoutes/ {IPdropped+=$2} /ipv6OutDiscards/ {IPdropped+=$4}'
	# shellcheck disable=SC2016
	SECTION_TCP='/tcpRetransSegs/ {TCPrexmits=$2} /tcpInUnorderSegs/ {TCPreorder=$2} /tcpInSegs/ {TCPpktRecv=$2} /tcpOutSegs/ {TCPpktSent=$4}'
	# shellcheck disable=SC2016
	SECTION_UDP='/udpOutErrors/ {UDPpktLost=$4} /udpInErrors/ {UDPunkPort=$5} /udpInDatagrams/ {UDPpktRecv=$3} /udpOutDatagrams/ {UDPpktSent=$2}'
elif [ "$KERNEL" = "AIX" ] ; then
	# shellcheck disable=SC2016
	FIGURE_SECTION='/^ip:$/ {inIP=1;inTCP=0;inUDP=0} /^tcp:$/ {inIP=0;inTCP=1;inUDP=0} /^udp:$/ {inIP=0;inTCP=0;inUDP=1} {if (NF==1 && $1 !~ /^ip:$|^udp:$|^tcp:$/) inIP=inTCP=inUDP=0}'
	# shellcheck disable=SC2016
	SECTION_IP='inIP && /output packets? (dropped|discarded)/ {IPdropped+=$1}'
	# shellcheck disable=SC2016
	SECTION_TCP='inTCP && /data packet.* bytes\) retransmitted$/ {TCPrexmits=$1} inTCP && /out-of-order packets?/ {TCPreorder=$1} inTCP && /packets? received$/ {TCPpktRecv=$1} inTCP && /packets? sent/ {TCPpktSent=$1}'
	# shellcheck disable=SC2016
	SECTION_UDP='inUDP && /datagrams? received$/ {UDPpktRecv=$1} inUDP && /datagrams? output$/ {UDPpktSent=$1} inUDP && /dropped due to full socket buffers$/ {UDPpktLost=$1} inUDP && /dropped due to no socket$/ {UDPunkPort=$1}'
elif [ "$KERNEL" = "Darwin" ] ; then
	# shellcheck disable=SC2016
	FIGURE_SECTION='/^ip:$/ {inIP=1;inTCP=0;inUDP=0} /^tcp:$/ {inIP=0;inTCP=1;inUDP=0} /^udp:$/ {inIP=0;inTCP=0;inUDP=1} {if (NF==1 && $1 !~ /^ip:$|^udp:$|^tcp:$/) inIP=inTCP=inUDP=0}'
	# shellcheck disable=SC2016
	SECTION_IP='inIP && /output packets? (dropped|discarded)/ {IPdropped+=$1}'
	# shellcheck disable=SC2016
	SECTION_TCP='inTCP && /data packets? .* retransmitted/ {TCPrexmits=$1} inTCP && /out-of-order packets?/ {TCPreorder=$1} inTCP && /packets? received$/ {TCPpktRecv=$1} inTCP && /packets? sent/ {TCPpktSent=$1}'
	# shellcheck disable=SC2016
	SECTION_UDP='inUDP && /datagrams? received$/ {UDPpktRecv=$1} inUDP && /datagrams? output$/ {UDPpktSent=$1} inUDP && /dropped due to full socket buffers$/ {UDPpktLost=$1} inUDP && /dropped due to no socket$/ {UDPunkPort=$1}'
elif [ "$KERNEL" = "HP-UX" ] ; then
	# shellcheck disable=SC2016
    FIGURE_SECTION='/^ip:$/ {inIP=1;inTCP=0;inUDP=0} /^tcp(Ext)?:$/ {inIP=0;inTCP=1;inUDP=0} /^udp:$/ {inIP=0;inTCP=0;inUDP=1} {if (NF==1 && $1 !~ /^ip:$|^udp:$|^tcp(Ext)?:$/) inIP=inTCP=inUDP=0}'
	# shellcheck disable=SC2016
    SECTION_IP='inIP && /fragments dropped/ {IPdropped=$1}'
	# shellcheck disable=SC2016
    SECTION_TCP='inTCP && /retransmited$/ {TCPrexmits=$1} inTCP && /out of order/ {TCPreorder=$1} inTCP && /[0-9] packets received$/ {TCPpktRecv=$1} inTCP && /[0-9] packets sent$/ {TCPpktSent=$1}'
	# shellcheck disable=SC2016
    SECTION_UDP='inUDP && /packets received/ {UDPpktRecv=$1} inUDP && /packets sent/ {UDPpktSent=$1} inUDP && /packet receive errors/ {UDPpktLost=$1} inUDP && /packets to unknown port received/ {UDPunkPort=$1}'
 elif [ "$KERNEL" = "FreeBSD" ] ; then
 	# shellcheck disable=SC2016
	FIGURE_SECTION='/^ip:$/ {inIP=1;inTCP=0;inUDP=0} /^tcp:$/ {inIP=0;inTCP=1;inUDP=0} /^udp:$/ {inIP=0;inTCP=0;inUDP=1} {if (NF==1 && $1 !~ /^ip:$|^udp:$|^tcp:$/) inIP=inTCP=inUDP=0}'
	# shellcheck disable=SC2016
	SECTION_IP='inIP && /output packets? (dropped|discarded)/ {IPdropped+=$1}'
	# shellcheck disable=SC2016
	SECTION_TCP='inTCP && /data packet.* bytes\) retransmitted$/ {TCPrexmits=$1} inTCP && /out-of-order packets?/ {TCPreorder=$1} inTCP && /packets? received$/ {TCPpktRecv=$1} inTCP && /packets? sent/ {TCPpktSent=$1}'
	# shellcheck disable=SC2016
	SECTION_UDP='inUDP && /datagrams? received$/ {UDPpktRecv=$1} inUDP && /datagrams? output$/ {UDPpktSent=$1} inUDP && /dropped due to full socket buffers$/ {UDPpktLost=$1} inUDP && /dropped due to no socket$/ {UDPunkPort=$1}'
fi

assertHaveCommand "$CMD"
$CMD | tee "$TEE_DEST" | $AWK "$HEADERIZE $FIGURE_SECTION $COMMON $SECTION_IP $SECTION_TCP $SECTION_UDP $PRINTF"  header="$HEADER"
echo "Cmd = [$CMD];  | $AWK '$HEADERIZE $FIGURE_SECTION $COMMON $SECTION_IP $SECTION_TCP $SECTION_UDP $PRINTF' header=\"$HEADER\"" >> "$TEE_DEST"