Interface datalink layer configuration tool for Linux

ifconfig.sh

#!/bin/sh

# Copyright 2015-2019 Rivoreo

# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:

# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE
# FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
# CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


# From net/if.h
IFF_UP=0x1
IFF_BROADCAST=0x2
IFF_DEBUG=0x4
IFF_LOOPBACK=0x8
IFF_POINTOPOINT=0x10
IFF_NOTRAILERS=0x20
IFF_RUNNING=0x40
IFF_NOARP=0x80
IFF_PROMISC=0x100
IFF_ALLMULTI=0x200
IFF_MASTER=0x400
IFF_SLAVE=0x800
IFF_MULTICAST=0x1000
IFF_PORTSEL=0x2000
IFF_AUTOMEDIA=0x4000
IFF_DYNAMIC=0x8000

# From net/arp.h
ARPHRD_NETROM=0
ARPHRD_ETHER=1
ARPHRD_AX25=3
ARPHRD_ARCNET=7
ARPHRD_DLCI=15
ARPHRD_ATM=19
ARPHRD_METRICOM=23
ARPHRD_EUI64=27
ARPHRD_INFINIBAND=32
ARPHRD_SLIP=256
ARPHRD_CSLIP=257
ARPHRD_SLIP6=258
ARPHRD_CSLIP6=259
ARPHRD_RSRVD=260
ARPHRD_ADAPT=264
ARPHRD_ROSE=270
ARPHRD_X25=271
ARPHRD_HWX25=272
ARPHRD_CAN=280
ARPHRD_PPP=512
ARPHRD_CISCO=513
ARPHRD_HDLC=$ARPHRD_CISCO
ARPHRD_LAPB=516
ARPHRD_DDCMP=517
ARPHRD_RAWHDLC=518
ARPHRD_TUNNEL=768
ARPHRD_TUNNEL6=769
ARPHRD_FRAD=770
ARPHRD_SKIP=771
ARPHRD_LOOPBACK=772
ARPHRD_LOCALTLK=773
ARPHRD_FDDI=774
ARPHRD_BIF=775
ARPHRD_SIT=776
ARPHRD_IPDDP=777
ARPHRD_IPGRE=778
ARPHRD_PIMREG=779
ARPHRD_HIPPI=780
ARPHRD_ASH=781
ARPHRD_ECONET=782
ARPHRD_IRDA=783
ARPHRD_FCPP=784
ARPHRD_FCAL=785
ARPHRD_FCPL=786
ARPHRD_FCFABRIC=787
ARPHRD_IEEE802_TR=800
ARPHRD_IEEE80211=801
ARPHRD_IEEE80211_PRISM=802
ARPHRD_IEEE80211_RADIOTAP=803
ARPHRD_IEEE802154=804
ARPHRD_IEEE802154_MONITOR=805
ARPHRD_PHONET=820
ARPHRD_PHONET_PIPE=821
ARPHRD_CAIF=822
ARPHRD_IP6GRE=823
ARPHRD_NETLINK=824
ARPHRD_6LOWPAN=825

flags_to_names() {
	if [ $# != 1 ]; then
		printf "flags_to_names: # (%s) != 1\\n" "$#" 1>&2
		exit 2
	fi
	local flags="$1"
	local names
	[ $((flags&IFF_UP)) != 0 ] && names="UP"
	[ $((flags&IFF_BROADCAST)) != 0 ] && names="$names,BROADCAST"
	[ $((flags&IFF_DEBUG)) != 0 ] && names="$names,DEBUG"
	[ $((flags&IFF_LOOPBACK)) != 0 ] && names="$names,LOOPBACK"
	[ $((flags&IFF_POINTOPOINT)) != 0 ] && names="$names,POINTOPOINT"
	[ $((flags&IFF_NOTRAILERS)) != 0 ] && names="$names,NOTRAILERS"
	[ $((flags&IFF_RUNNING)) != 0 ] && names="$names,RUNNING"
	[ $((flags&IFF_NOARP)) != 0 ] && names="$names,NOARP"
	[ $((flags&IFF_PROMISC)) != 0 ] && names="$names,PROMISC"
	[ $((flags&IFF_ALLMULTI)) != 0 ] && names="$names,ALLMULTI"
	[ $((flags&IFF_MASTER)) != 0 ] && names="$names,MASTER"
	[ $((flags&IFF_SLAVE)) != 0 ] && names="$names,SLAVE"
	[ $((flags&IFF_MULTICAST)) != 0 ] && names="$names,MULTICAST"
	[ $((flags&IFF_PORTSEL)) != 0 ] && names="$names,PORTSEL"
	[ $((flags&IFF_AUTOMEDIA)) != 0 ] && names="$names,AUTOMEDIA"
	[ $((flags&IFF_DYNAMIC)) != 0 ] && names="$names,DYNAMIC"
	printf %s\\n "${names#,}"
}

type_to_name() {
	if [ $# != 1 ]; then
		printf "type_to_name: # (%s) != 1\\n" "$#" 1>&2
		exit 2
	fi
	case "$1" in
		$ARPHRD_NETROM)
			echo netrom
			;;
		$ARPHRD_ETHER)
			echo ether
			;;
		$ARPHRD_AX25)
			echo ax25
			;;
		$ARPHRD_ARCNET)
			echo arcnet
			;;
		$ARPHRD_DLCI)
			echo dlci
			;;
		$ARPHRD_EUI64)
			echo eui64
			;;
		$ARPHRD_INFINIBAND)
			echo infiniband
			;;
		$ARPHRD_SLIP)
			echo slip
			;;
		$ARPHRD_CSLIP)
			echo cslip
			;;
		$ARPHRD_SLIP6)
			echo slip6
			;;
		$ARPHRD_CSLIP6)
			echo cslip6
			;;
		$ARPHRD_ROSE)
			echo rose
			;;
		$ARPHRD_X25)
			echo x25
			;;
		$ARPHRD_PPP)
			echo ppp
			;;
		$ARPHRD_HDLC)
			echo hdlc
			;;
		$ARPHRD_LAPB)
			echo lapb
			;;
		$ARPHRD_TUNNEL)
			echo tunnel
			;;
		$ARPHRD_FRAD)
			echo frad
			;;
		$ARPHRD_LOOPBACK)
			echo loop
			;;
		$ARPHRD_FDDI)
			echo fddi
			;;
		$ARPHRD_SIT)
			echo sit
			;;
		$ARPHRD_HIPPI)
			echo hippi
			;;
		$ARPHRD_ECONET)
			echo ec
			;;
		$ARPHRD_IRDA)
			echo irda
			;;
		$ARPHRD_IEEE802_TR)
			echo tr
			;;
		*)
			echo unknown
			;;
	esac
}

human_readable() {
	if [ $# != 3 ]; then
		printf "human_readable: # (%s) != 3\\n" "$#" 1>&2
		exit 2
	fi
	local n=${1}0
	local unit=$2
	local suffix=$3
	while [ $n -ge 10240 ]; do
		case "$unit" in
			"")
				unit=Ki
				;;
			Ki)
				unit=Mi
				;;
			Mi)
				unit=Gi
				;;
			Gi)
				unit=Ti
				;;
			Ti)
				unit=Pi
				;;
			Pi)
				break
				;;
			*)
				printf "human_readable: unknown unit '%s'\\n" "$unit" 1>&2
				exit 2
				;;
		esac
		n=$((n/1024))
	done
	i=${n%?}
	[ -n "$unit" ] && n=${i}.${n#$i} || n=$i
	printf "%s %s%s\\n" "$n" "$unit" "$suffix"
}

print_config() {
	local d flags mtu index type address txqueuelen packets bytes speed duplex
	if [ $# != 1 ]; then
		printf "print_config: # (%s) != 1\\n" "$#" 1>&2
		exit 2
	fi
	d="/sys/class/net/$1"
	if [ ! -d "$d" ]; then
		printf "ifconfig: interface %s doesn't exist\\n" "$1" 1>&2
		return 1
	fi
	flags="`cat $d/flags`" || flags=0
	mtu="`cat $d/mtu`" || mtu=0
	printf "%s: flags=%s<%s> mtu %s" "$1" "$flags" "`flags_to_names $flags`" "$mtu"
	index="`cat $d/ifindex`" && printf " index %s" "$index"
	type="`cat $d/type`"
	address="`cat $d/address`"
	txqueuelen="`cat $d/tx_queue_len`"
	printf "\\n	%s %s txqueuelen %s\\n" "`type_to_name $type`" "$address" "$txqueuelen"
	for i in rx tx; do
		dm="`printf %s $i | sed y/rtx/RTX/`"
		if packets="`cat $d/statistics/${i}_packets`" && bytes="`cat $d/statistics/${i}_bytes`"; then
			printf "	%s packets %s bytes %s (%s)\\n" "$dm" "$packets" "$bytes" "`human_readable $bytes '' B`"
		fi
		if errors="`cat $d/statistics/${i}_errors`" && dropped="`cat $d/statistics/${i}_dropped`" && overruns="`cat $d/statistics/${i}_fifo_errors`"; then
			printf "	%s errors %s dropped %s overruns %s\\n" "$dm" "$errors" "$dropped" "$overruns"
		fi
	done
	#case "$type" in
	#	1)
	#		if speed="`cat $d/speed`" && duplex="`cat $d/duplex`"; then
	#		fi
	#		;;
	#esac
}

print_config_all() {
	for d in /sys/class/net/*; do
		[ -d "$d" ] || continue
		print_config "${d#/sys/class/net/}"
	done
}

print_usage() {
	printf "Usage: %s { -a | <interface> [<options>] }\\n" "$1" 1>&2
}

set_flags() {
	local flags
	if [ $# != 3 ]; then
		printf "set_flags: # (%s) != 3\\n" "$#" 1>&2
		exit 2
	fi
	flags="`cat \"/sys/class/net/$1/flags\"`" || return 1
	if [ $((flags&$2)) = 0 ]; then
		[ $3 = 0 ] && return 0
		echo $((flags|$2)) > "/sys/class/net/$1/flags"
	else
		[ $3 = 1 ] && return 0
		echo $((flags&(~$2))) > "/sys/class/net/$1/flags"
	fi
}

set_mtu() {
	if [ $# != 2 ]; then
		printf "set_mtu: # (%s) != 2\\n" "$#" 1>&2
		exit 2
	fi
	printf %s\\n "$2" > "/sys/class/net/$1/mtu"
}

set_txqueuelen() {
	if [ $# != 2 ]; then
		printf "set_txqueuelen: # (%s) != 2\\n" "$#" 1>&2
		exit 2
	fi
	printf %s\\n "$2" > "/sys/class/net/$1/tx_queue_len"
}

end_of_options=
if [ "$1" = -- ]; then
	end_of_options=1
	shift
fi
if [ $# -lt 1 ]; then
	print_usage "$0"
	exit 255
fi

if [ -z "$end_of_options" ]; then case "$1" in
	-a)
		print_config_all
		exit 0
		;;
	-h)
		print_usage
		exit 0
		;;
	-*)
		printf "ifconfig: Invalid option '%s'\\n" "$1" 1>&2
		exit 255
		;;
esac fi

if [ $# = 1 ]; then
	print_config "$1"
	exit
fi

interface="$1"
shift
set -e
while [ $# -gt 0 ]; do
	case "$1" in
		up)
			set_flags "$interface" $IFF_UP 1
			;;
		down)
			set_flags "$interface" $IFF_UP 0
			;;
		mtu)
			if [ $# -lt 2 ]; then
				echo "ifconfig: 'mtu' needs an argument" 1>&2
				return 255
			fi
			set_mtu "$interface" "$2"
			shift
			;;
		txqueuelen)
			if [ $# -lt 2 ]; then
				echo "ifconfig: 'txqueuelen' needs an argument" 1>&2
				return 255
			fi
			set_txqueuelen "$interface" "$2"
			shift
			;;
		arp)
			set_flags "$interface" $IFF_ARP 1
			;;
		noarp|-arp)
			set_flags "$interface" $IFF_ARP 0
			;;
		promisc)
			set_flags "$interface" $IFF_PROMISC 1
			;;
		nopromisc|-promisc)
			set_flags "$interface" $IFF_PROMISC 0
			;;
		allmulti)
			set_flags "$interface" $IFF_ALLMULTI 1
			;;
		noallmulti|-allmulti)
			set_flags "$interface" $IFF_ALLMULTI 0
			;;
		multicast)
			set_flags "$interface" $IFF_MULTICAST 1
			;;
		dynamic)
			set_flags "$interface" $IFF_DYNAMIC 1
			;;
		nodynamic|-dynamic)
			set_flags "$interface" $IFF_DYNAMIC 0
			;;
		*)
			printf "ifconfig: unknown option '%s'\n" "$1" 1>&2
			exit 255
	esac
	shift
done