InterfaceUtils.sh

#!/usr/bin/env bash

#if [ "$InterfaceUtilsVersion" ]; then return 0; fi
#readonly InterfaceUtilsVersion="1.0"

# The methods used in this script are taken from airmon-ng.
# This is all thanks for the airmon-ng authors, thanks guys.
InterfaceUtilsOutputDevice="/dev/stdout"

if [ -d /sys/bus/usb ] # && hash lsusb;
  then InterfaceUSBBus=1
fi

if [ -d /sys/bus/pci -o -d /sys/bus/pci_express -o -d /proc/bus/pci ] # && hash lspci;
	then InterfacePCIBus=1
fi

# Checks if the interface belongs to a physical device.
function interface_is_real() {
  test -d /sys/class/net/$1/device
  return $?
}

# Checks if the interface belongs to a wireless device.
function interface_is_wireless() {
  grep -qs "DEVTYPE=wlan" /sys/class/net/$1/uevent
  return $?
}

# Returns an array of absolutely all interfaces.
# Notice: That includes interfaces such as the loopback interface.
function interface_list_all() {
  InterfaceListAll=(/sys/class/net/*)
  InterfaceListAll=("${InterfaceListAll[@]//\/sys\/class\/net\//}")
}

# Returns an array of interfaces pertaining to a wireless device.
function interface_list_wireless() {
  InterfaceListWireless=()
  interface_list_all
  local __interface_list_wireless__candidate
  for __interface_list_wireless__candidate in "${InterfaceListAll[@]}"; do
    if interface_is_wireless $__interface_list_wireless__candidate; then InterfaceListWireless+=("$__interface_list_wireless__candidate")
    fi
  done
}

function interface_driver() {
  InterfaceDriver=$(basename $(readlink /sys/class/net/$1/device/driver))
}

function interface_physical() {
  if [ ! "$1" ]; then return 1; fi

  unset InterfacePhysical

  local -r interface_physical_path="/sys/class/net/$1/phy80211"

  if [ -d "$interface_physical_path" ]; then
    if [ -r "$interface_physical_path/name" ]; then InterfacePhysical="$(cat "$interface_physical_path/name")"
    fi
    if [ ! "${InterfacePhysical// /}" ]; then InterfacePhysical="$(ls -l "$interface_physical_path" | sed 's/^.*\/\([a-zA-Z0-9_-]*\)$/\1/')"
    fi
  fi

  if [ ! "$InterfacePhysical" ]; then return 2; fi
}

function interface_hardware() {
  if [ ! "$1" ]; then return 1; fi

  local __interface_hardware__device="/sys/class/net/$1/device"
  local __interface_hardware__hwinfo="$__interface_hardware__device/modalias"

  InterfaceHardwareBus="$(cut -d ":" -f 1 "$__interface_hardware__hwinfo" 2>$InterfaceUtilsOutputDevice)"

  case "$InterfaceHardwareBus" in
  "usb") # Wanted to replace the line below with awk, but i'll probably just add complexity & issues (mawk vs gawk).
    InterfaceHardwareID="$(cut -d ":" -f 2 $__interface_hardware__hwinfo | cut -b 1-10 | sed 's/^.//;s/p/:/')"
    ;;
  "pci" | "pcmcia" | "sdio")
    InterfaceHardwareID="$(cat "$__interface_hardware__device/vendor" 2>$InterfaceUtilsOutputDevice):$(cat "$__interface_hardware__device/device" 2>$InterfaceUtilsOutputDevice)"
    ;;
  default) # The following will only work for USB devices.
    InterfaceHardwareID="$(cat "$__interface_hardware__device/idVendor" 2>$InterfaceUtilsOutputDevice):$(cat "$__interface_hardware__device/idProduct" 2>$InterfaceUtilsOutputDevice)"
    InterfaceHardwareBus="usb"
    ;; # This will be reset below if InterfaceHardwareID is invalid.
  esac

  # Check for invalid InterfaceHardwareID (starts or ends with :) .. not a happy face, still won't quote it.
  if echo "$InterfaceHardwareID" | grep -Eq "^:|:$"; then
    unset InterfaceHardwareID
    unset InterfaceHardwareBus
    return 2
  else
    # Remove any extraneous hex markers.
    InterfaceHardwareID=${InterfaceHardwareID//0x/}
  fi
}

function interface_chipset() {
  # Clear previous values to avoid stale chipset info when detection fails.
  InterfaceChipset=""
  InterfaceHardwareBus=""
  InterfaceHardwareID=""

  if [ ! "$1" ]; then return 1; fi

  if ! interface_hardware "$1"; then
    InterfaceChipset="Unknown device chipset"
    return 2
  fi

  case "$InterfaceHardwareBus" in
  "usb")
    if [ ! "$InterfaceUSBBus" ]; then return 3; fi
    InterfaceChipset="$(lsusb -d "$InterfaceHardwareID" | head -n1 - | cut -f3- -d ":" | sed 's/^....//;s/ Network Connection//g;s/ Wireless Adapter//g;s/^ //')"
    ;;
  "pci" | "pcmcia")
    if [ ! "$InterfacePCIBus" ]; then return 4; fi
    InterfaceChipset="$(lspci -d $InterfaceHardwareID | cut -f3- -d ":" | sed 's/Wireless LAN Controller //g;s/ Network Connection//g;s/ Wireless Adapter//;s/^ //')"
    ;;
  "sdio")
    if [[ "${InterfaceHardwareID,,}" == "02d0"* ]]; then InterfaceChipset=$(printf "Broadcom %d" 0x${InterfaceHardwareID:5})
    else InterfaceChipset="Unknown chipset for SDIO device."
    fi
    ;;
  default)
    InterfaceChipset="Unknown device chipset & device bus."
    ;;
  esac

  # Ensure we never leak a previous value on unexpected paths.
  if [ -z "$InterfaceChipset" ]; then InterfaceChipset="Unknown device chipset"; fi
}

function interface_bands() {
	if [ ! "$1" ]; then return 1; fi
	InterfaceBands=""
	interface_physical "$1"
	if [ ! "$InterfacePhysical" ]; then return 2; fi
	local __interface_bands__iw
	__interface_bands__iw=$(command -v iw 2>/dev/null || echo /usr/sbin/iw)
	if [ ! -x "$__interface_bands__iw" ]; then return 3; fi
	local __interface_bands__info
	__interface_bands__info=$("$__interface_bands__iw" phy "$InterfacePhysical" info 2>/dev/null)
	if [ ! "$__interface_bands__info" ]; then return 4; fi
	local __interface_bands__list=""
	if echo "$__interface_bands__info" | grep -qE "24[0-9][0-9][.0-9]* MHz"; then __interface_bands__list="2.4GHz"; fi
	if echo "$__interface_bands__info" | grep -qE "5[0-9]{3}[.0-9]* MHz"; then
		[ "$__interface_bands__list" ] && __interface_bands__list="$__interface_bands__list/" || true
		__interface_bands__list="${__interface_bands__list}5GHz"
	fi
	if echo "$__interface_bands__info" | grep -qE "6[0-9]{3}[.0-9]* MHz"; then
		[ "$__interface_bands__list" ] && __interface_bands__list="$__interface_bands__list/" || true
		__interface_bands__list="${__interface_bands__list}6GHz"
	fi
	InterfaceBands="${__interface_bands__list:-unknown}"
}

# Returns the bus type of a wireless interface (usb, pci, or unknown).
# Result is stored in InterfaceBus.
function interface_bus() {
	if [ ! "$1" ]; then return 1; fi
	InterfaceBus=""
	local __device_path
	__device_path=$(readlink -f "/sys/class/net/$1/device" 2>/dev/null)
	if [ ! "$__device_path" ] || [ ! -d "$__device_path" ]; then
		InterfaceBus="unknown"
		return 2
	fi
	local __uevent="$__device_path/uevent"
	if [ -f "$__uevent" ]; then
		if grep -q "^MODALIAS=usb:" "$__uevent" 2>/dev/null; then
			InterfaceBus="usb"; return 0
		elif grep -q "^MODALIAS=pci:" "$__uevent" 2>/dev/null; then
			InterfaceBus="pci"; return 0
		elif grep -q "^MODALIAS=sdio:" "$__uevent" 2>/dev/null; then
			InterfaceBus="sdio"; return 0
		fi
	fi
	# Fallback: check the resolved device path for bus indicators.
	if echo "$__device_path" | grep -q "/usb[0-9]*/"; then
		InterfaceBus="usb"; return 0
	fi
	InterfaceBus="unknown"
}

function interface_state() {
  if [ ! "$1" ]; then return 1; fi
  local __interface_state__stateFile="/sys/class/net/$1/operstate"

  if [ ! -f "$__interface_state__stateFile" ]; then return 2; fi
  InterfaceState=$(cat "$__interface_state__stateFile")
}

function interface_set_state() {
  if [ "${#@}" -ne 2 ]; then return 1; fi
  # TODO: Add alternatives to 'ip' in case of failure.
  ip link set "$1" "$2"
  return $?
}

function interface_set_mode() {
  if [ "${#@}" -ne 2 ]; then return 1; fi
  if ! interface_set_state "$1" "down"; then return 2; fi
  if ! iw dev "$1" set type "$2" &> $InterfaceUtilsOutputDevice; then
    if ! iwconfig "$1" mode "$2" &> $InterfaceUtilsOutputDevice
      then return 3
    fi
  fi
  if ! interface_set_state "$1" "up"; then return 4; fi
}

function interface_reidentify() {
  if [ ${#@} -ne 2 ]; then return 1; fi

  local -r __interface_reidentify__oldIdentifier=$1
  local -r __interface_reidentify__newIdentifier=$2

  if [[ $__interface_reidentify__newIdentifier == *" "* ]]
    then return 2
  fi

  # Check if interface already has the desired name
  if [ "$__interface_reidentify__oldIdentifier" = "$__interface_reidentify__newIdentifier" ]; then
    return 0
  fi

  if ! interface_set_state $__interface_reidentify__oldIdentifier down
    then return 3
  fi

  # TODO: Add alternatives to 'ip' in case of failure.
  ip link set $__interface_reidentify__oldIdentifier name $__interface_reidentify__newIdentifier 2>/dev/null
  local result=$?
  
  # If rename failed because name already exists, check if it's our interface
  if [ $result -ne 0 ]; then
    if ip link show "$__interface_reidentify__newIdentifier" &>/dev/null; then
      # Name exists - if old interface is gone, assume it was already renamed
      if ! ip link show "$__interface_reidentify__oldIdentifier" &>/dev/null; then
        return 0
      fi
    fi
  fi
  
  return $result
}

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