init.sh/lib/net.sh

#!/bin/bash
# ------------------------------------------------------------------------------
# Network functions
# This file is part of the init.sh project
# Copyright (c) 2019-2024 Geoffray Levasseur <fatalerrors@geoffray-levasseur.org>
# ------------------------------------------------------------------------------
# This file is distributed under 3-clause BSD license.
# The complete license agreement can be obtained at:
# https://opensource.org/licenses/BSD-3-Clause
# ------------------------------------------------------------------------------

# Network interfaces list
export IF_LIST=''

# IPv4 vars:
export DEF_IP4=''
export DEF_CIDR4=''
export DEF_NETMASK4=''
export DEF_ROUTE4=''

# IPv6 vars
export DEF_IP6=''
export DEF_CIDR6=''
export DEF_ROUTE6=''

# ------------------------------------------------------------------------------
# Set system proxy vars
set_system_proxy()
{
    # Declare proxy system vars if needed and if not already declared
    if [[ -n $PROXY_SRV && -n $PROXY_SRV_PORT && -z $NO_PROXY ]]; then
	export http_proxy=${http_proxy:-"http://$PROXY_SRV:$PROXY_SRV_PORT/"}
	export https_proxy=${https_proxy:-"http://$PROXY_SRV:$PROXY_SRV_PORT/"}
    fi
}
export -f set_system_proxy
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Convert a netmask to a CIDR notation (IPv4)
mask2cidr4()
{
    # Assumes there's no "255." after a non-255 byte in the mask
    local x=${1##*255.}
    set -- 0^^^128^192^224^240^248^252^254^ $(( (${#1} - ${#x})*2 )) ${x%%.*}
    x=${1%%$3*}
    echo $(( $2 + (${#x}/4) ))
}
export -f mask2cidr4
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Convert a CIDR notation to a netmask (IPv4)
cidr2mask4()
{
    # Number of args to shift, 255..255, first non-255 byte, zeroes
    set -- $(( 5 - ($1 / 8) )) 255 255 255 255 $(( (255 << (8 - ($1 % 8))) & 255 )) 0 0 0
    [[ $1 -gt 1 ]] && shift $1 || shift
    echo ${1-0}.${2-0}.${3-0}.${4-0}
}
export -f cidr2mask4
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Determine if parameter is a valid IPv4 address
isipv4 ()
{
    # Set up local variables
    local  ip=$1

    # Start with a regex format test
    if [[ $ip =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
	local old_ifs=$IFS
	IFS="."
	ip=($ip)
	IFS=$old_ifs
	if [[ ${ip[0]} -le 255 && ${ip[1]} -le 255 \
	    && ${ip[2]} -le 255 && ${ip[3]} -le 255 ]]; then
	    return 0
	fi
    fi
    return 1
}
export -f isipv4
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Determine if parameter is a valid IPv4 address
isipv6 ()
{
    local ip="$1"
    local regex='^([0-9a-fA-F]{0,4}:){1,7}[0-9a-fA-F]{0,4}$'
    if [[ $ip =~ $regex ]]; then
	return 0
    fi
    return 1
}
export -f isipv6
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Extract network information
get_network_info()
{
    # Get info on v4 net first
    export DEF_ROUTE4=$(ip route | awk '/default/ { print $3 }')
    export DEF_IF4=$(ip route | awk '/default/ { print $5 }')
    export DEF_IP4=$(ip -o route get 1.1.1.1 | cut -d " " -f 7)
    export DEF_CIDR4=$(ip addr show | grep -w inet | grep -v 127.0.0.1 | \
	awk '{ print $2}' | cut -d "/" -f 2)
    export DEF_NETMASK4=$(cidr2mask4 $DEF_CIDR4)
    export IP4_LIST=$(ip addr show | grep -w inet | grep -v 127.0.0.1 | \
	awk '{ print $2}' | cut -d "/" -f 1)

    # Now get v6 net infos
    export DEF_ROUTE6=$(ip -6 route | awk '/default/ { print $3 }')
    export DEF_IF6=$(ip -6 route | awk '/default/ { print $5 }')
    export DEF_IP6=$(ip -6 -o route get 2001:503:ba3e::2:30 | cut -d " " -f 11)
    export DEF_CIDR6=$(ip addr show | grep -w inet6 | grep -v ::1 | \
	awk 'FNR==1 { print $2}' | cut -d "/" -f 2)
    export IP6_LIST=$(ip addr show | grep -w inet6 | grep -v ::1 | \
	awk '{ print $2}' | cut -d "/" -f 1)

    for iface in $(ip -o -4 addr list | awk '{print $2}' | tr '\n' ' '); do
	export IF_LIST=$(trim "$IF_LIST $iface")
	ipaddr=$(ip -o -4 addr list $iface | awk '{print $4}' | cut -d/ -f1)
	export IP4_LIST
    done
    for iface in $(ip -o -6 addr list | awk '{print $2}' | tr '\n' ' '); do
	if [[ ! $(echo $IF_LIST | grep $iface) ]]; then
	    export IF_LIST=$(trim "$IF_LIST $iface")
	fi
	ipaddr=$(ip -o -6 addr list $iface | awk '{print $4}' | cut -d/ -f1)
	export IP4_LIST
    done
}
export -f get_network_info
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Check availability of different aspect of the network
check_network()
{
    case $1 in
	"print")
	    if [[ -n $DEF_IP4 ]]; then
		prnt I "Your default (routed) address is: $DEF_IP4/$DEF_CIDR4 ($DEF_NETMASK4) on $DEF_IF4"
		prnt I "Your default IPv4 route is: $DEF_ROUTE4"
	    fi
	    if [[ -n $DEF_IP6 ]]; then
		prnt I "Your default (routed) IPv6 address is: $DEF_IP6/$DEF_CIDR6 on $DEF_IF6"
		prnt I "Your default IPv6 route is: $DEF_ROUTE6"
	    fi
	    prnt I "Here is the full list of detected v4 addresses:"
	    echo -e "         +------------+-------------------------------------------+"
	    echo -e "         |  Interface | IP Address                                |"
	    echo -e "         +------------+-------------------------------------------+"
	    for iface in $IF_LIST; do
		ipaddr=$(ip -o -4 addr list $iface | awk '{print $4}')
		for addr in $ipaddr; do
		    printf "         |%11s | %-42s|\n" $iface $addr
		done
		ipaddr=$(ip -o -6 addr list $iface | awk '{print $4}')
		for addr in $ipaddr; do
		    printf "         |%11s | %-42s|\n" $iface $addr
		done
	    done
	    echo "         +------------+-------------------------------------------+"
	;;
	"lan")
	    return 0
	;;
	"ternet")
	    return 0
	;;
    esac
}
export -f check_network
# ------------------------------------------------------------------------------

# EOF