util: add function mtu_is_valid

[people/stevee/network.git] / src / functions / functions.util

#!/bin/bash
###############################################################################
#                                                                             #
# IPFire.org - A linux based firewall                                         #
# Copyright (C) 2010  Michael Tremer & Christian Schmidt                      #
#                                                                             #
# This program is free software: you can redistribute it and/or modify        #
# it under the terms of the GNU General Public License as published by        #
# the Free Software Foundation, either version 3 of the License, or           #
# (at your option) any later version.                                         #
#                                                                             #
# This program is distributed in the hope that it will be useful,             #
# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
# GNU General Public License for more details.                                #
#                                                                             #
# You should have received a copy of the GNU General Public License           #
# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
#                                                                             #
###############################################################################

# A simple print statement
print() {
	local fmt=${1}; shift

	printf -- "${fmt}\n" "$@"
}

# The args() function takes a number of arguments like
#   var1="abc d" var2="abc" var3="abcd e"
# and splits them into several arguments, devided by newline
args() {
	echo "$@" | xargs printf "%s\n"
}

unquote() {
	local var="$@"

	if [ "${var:0:1}" = "\"" ]; then
		var=${var:1}
	fi

	local last=$(( ${#var} - 1 ))
	if [ ${last} -ge 0 ] && [ "${var:${last}:1}" = "\"" ]; then
		var=${var:0:${last}}
	fi

	print "${var}"
}

quote() {
	print "\"%s\"" "$@"
}

strip() {
	local value="$@"

	# remove leading whitespace characters
	value="${value#"${value%%[![:space:]]*}"}"

	# remove trailing whitespace characters
	value="${value%"${value##*[![:space:]]}"}"

	print "${value}"
}

# Print a pretty error message
error() {
	echo -e " ${CLR_RED_B}ERROR${CLR_RESET}  : $@" >&2
}

error_log() {
	log ERROR "$@"
}

# Print a pretty warn message
warning() {
	echo -e " ${CLR_YELLOW_B}WARNING${CLR_RESET}: $@" >&2
}

warning_log() {
	log WARNING "$@"
}

# The next three functions are kept for backwards
# compatibility. The need to be dropped at some time.
listsort() {
	list_sort $@
}

listmatch() {
	list_match $@
}

listlength() {
	list_length $@
}

# Speedup function to avoid a call of the basename binary
basename() {
	echo "${1##*/}"
}

format() {
	local key=${1}
	assert isset key

	local format=${2}
	assert isset format

	shift 2

	printf -v "${key}" "${format}" "$@"
}

format_time() {
	local s=${1}
	local ret m

	local units="s m h"

	local unit
	for unit in ${units}; do
		m=$(( ${s} % 60 ))
		s=$(( ${s} / 60 ))

		if [ ${m} -gt 0 ]; then
			ret="${m}${unit} ${ret}"
		fi
	done

	# Remove whitespace
	echo ${ret}
}

parse_time() {
	local ret=0

	local arg
	for arg in $@; do
		local unit

		case "${arg}" in
			*h|*m|*s)
				# Store unit
				unit="${arg: -1}"

				# Remove unit
				arg="${arg:0:-1}"
				;;
		esac

		if ! isinteger arg; then
			return ${EXIT_ERROR}
		fi

		# Convert hours and minutes into seconds
		case "${unit}" in
			h)
				arg=$(( ${arg} * 3600 ))
				;;
			m)
				arg=$(( ${arg} * 60 ))
				;;
		esac

		# Add up everything
		ret=$(( ${ret} + ${arg} ))
	done

	print "${ret}"
}

assign() {
	local key=${1}
	assert isset key
	shift

	format "${key}" "%s" "$@"
}

fread() {
	local file=${1}
	assert isset file

	[ -r "${file}" ] || return ${EXIT_ERROR}

	print "$(<${file})"
}

fwrite() {
	local file=${1}
	assert isset file
	shift

	if [ ! -w "${file}" ]; then
		log ERROR "${file}: No such file"
		return ${EXIT_ERROR}
	fi

	print "%s" "$@" >> ${file} 2>/dev/null
}

make_parent_dir() {
	local path="${1}"

	local dirname="$(dirname "${path}")"
	mkdir -p "${dirname}"
}

enabled() {
	local param=${1}

	list_match "${!param}" yes on true 1
}

mac_generate() {
	local b="$(random 12)"

	# Remove multicast bit
	# and set address is software assigned
	local first_byte=$(( 0x${b:0:2} & 0xfe ))
	first_byte=$(( ${first_byte} | 0x02 ))

	local output
	printf -v output "%02x" "${first_byte}"

	output="${output}:${b:2:2}:${b:4:2}:${b:6:2}:${b:8:2}:${b:10:2}"

	# Check if output is valid
	assert mac_is_valid "${output}"

	echo "${output}"
}

mac_format() {
	local mac=${1}
	assert isset mac

	# Remove all colons and make the rest lowercase.
	mac=${mac//:/}
	mac=${mac,,}

	local output
	if [ "${#mac}" = "12" ]; then
		# Add colons (:) to mac address
		output=${mac:0:2}
		local i
		for i in 2 4 6 8 10; do
			output="${output}:${mac:${i}:2}"
		done
	else
		output=${mac}
	fi

	assert mac_is_valid ${output}

	print "${output}"
}

mac_is_valid() {
	local mac=${1}

	[[ ${mac} =~ ^([0-9a-f]{2}\:){5}[0-9a-f]{2}$ ]]
}

uuid() {
	echo $(</proc/sys/kernel/random/uuid)
}

rand() {
	local uuid="$(uuid)"
	echo "${uuid//-/}"
}

random() {
	local length="${1:-8}"

	local random
	while [ ${#random} -lt ${length} ]; do
		random="${random}$(rand)"
	done

	echo "${random:0:${length}}"
}

isset() {
	local var=${1}

	[ -n "${!var}" ]
}

isoneof() {
	local var=${!1}
	shift

	list_match "${var}" "$@"
}

isbool() {
	local var=${1}

	isoneof ${var} 0 1 no yes on off
}

isinteger() {
	local var=${!1}

	[[ ${var} =~ ^[0-9]+$ ]]
}

ismac() {
	local mac=${!1}

	mac_is_valid ${mac}
}

isipaddress() {
	local addr=${!1}

	ip_is_valid ${addr}
}

mtu_is_valid() {
	local proto=${1}
	local mtu=${2}

	case ${proto} in
		ipv4)
			[ ${mtu} -ge 576 ] && [ ${mtu} -le 9000 ]
			;;
		ipv6)
			[ ${mtu} -ge 1280 ] && [ ${mtu} -le 9000 ]
			;;
		*)
			error "${proto} is not a valid proto"
			return ${EXIT_ERROR}
			;;
	esac
}

backtrace() {
	local start=1

	echo # Empty line
	error_log "Backtrace (most recent call in first line):"

	local i source
	for i in $(seq ${start} ${#BASH_SOURCE[*]}); do
		[ -z "${FUNCNAME[${i}]}" ] && continue

		# Print called binary with arguments.
		if [ "${FUNCNAME[${i}]}" == "main" ]; then
			local args="$(list_reverse ${BASH_ARGV[*]})"
			printf -v source "%20s" "$0"
			error_log "  ${source} ${args}"
			continue
		fi

		source=${BASH_SOURCE[$(( ${i} + 1 ))]}
		error_log "  $(printf "%20s" "'${FUNCNAME[${i}]}'") called from ${source:-<shell>}:${BASH_LINENO[${i}]}"
	done
}

assert() {
	local assertion="$@"

	if ! ${assertion}; then
		error_log "Assertion '${assertion}' failed."
		backtrace
		exit ${EXIT_ERROR_ASSERT}
	fi

	return ${EXIT_OK}
}

# This function checks, if the given argument is an assert error
# exit code. If this is the case, the script will halt immediately.
assert_check_retval() {
	local ret=${1}

	if [ ${ret} -eq ${EXIT_ERROR_ASSERT} ]; then
		exit ${EXIT_ERROR_ASSERT}
	fi

	return ${ret}
}

# This function executes the given command and inverses the return code
not() {
	local command="$@"

	${command} && return ${EXIT_FALSE} || return ${EXIT_TRUE}
}

exec_cmd() {
	local cmd=$@

	log DEBUG "Running command: ${cmd}"

	DEBUG=${DEBUG} \
	LOG_DISABLE_STDOUT="${LOG_DISABLE_STDOUT}" \
	LOG_FACILITY="${LOG_FACILITY}" \
		${SHELL} ${cmd}
	local ret=$?

	#log DEBUG "Returned with code '${ret}'"

	if [ ${ret} -eq ${EXIT_ERROR_ASSERT} ]; then
		error_log "Stopping parent process due to assertion error in child process: ${cmd}"
		exit ${EXIT_ERROR_ASSERT}
	fi

	return ${ret}
}

cmd() {
	local cmd=$@

	log DEBUG "Running command: ${cmd}"

	${cmd}
	local ret=$?

	log DEBUG "Returned with code '${ret}'"

	return ${ret}
}

cmd_quiet() {
	cmd $@ &>/dev/null
}

cmd_exec() {
	local cmd=$@

	log DEBUG "Exec'ing command: ${cmd}"

	exec ${cmd}

	log ERROR "Could not exec-ute: ${cmd}"
	exit ${EXIT_ERROR}
}

cmd_not_implemented() {
	assert false "not implemented"
}

# Runs a command in a clean environment so that no confidential information
# is leaked to any untrusted commands.
cmd_clean_environment() {
	local cmd=$@

	log DEBUG "Running command in a clean environment: ${cmd}"
	env -i -- ${cmd}
	local ret=${?}

	log DEBUG "Returned with code '${ret}'"
	return ${ret}
}

# Executes the given command in background
cmd_background() {
	cmd_quiet $@ &
}

# Prints the PID of the process that was started last
cmd_background_get_pid() {
	print "${!}"
}

cmd_background_result() {
	local pids=$@

	wait ${pids}
}

# Increase security of the read command
read() {
	builtin read -r $@
}

seq() {
	if [ $# -eq 2 ]; then
		eval echo {${1}..${2}}
	elif [ $# -eq 3 ]; then
		eval echo {${1}..${3}..${2}}
	fi
}

range() {
	eval echo {0..$(( ${1} - 1 ))}
}

count() {
	local i=0

	while read; do
		((i++))
	done

	echo ${i}
}

which() {
	type -P $@
}

# Prints the number of seconds since epoch.
timestamp() {
	date -u "+%s"
}

beautify_time() {
	local value=${1}

	local unit
	local limit
	for unit in s m h d w; do
		case "${unit}" in
			s|m|h)
				limit=60
				;;
			d)
				limit=24
				;;
			w)
				limit=7
				;;
		esac

		[ ${value} -lt ${limit} ] && break

		value=$(( ${value} / ${limit} ))
	done

	echo "${value}${unit}"
}

beautify_bytes() {
	local value=${1}

	local unit
	local limit=1024
	for unit in B k M G T; do
		[ ${value} -lt ${limit} ] && break
		value=$(( ${value} / ${limit} ))
	done

	echo "${value}${unit}"
}

module_load() {
	local module=${1}

	if ! grep -q "^${module}" /proc/modules; then
		log DEBUG "Loading module '${module}'."
		modprobe ${module}
	fi
}

binary_exists() {
	local binary=${1}

	if [ -n "$(type -p ${binary})" ]; then
		return ${EXIT_OK}
	fi

	return ${EXIT_ERROR}
}

function_exists() {
	local function="${1}"

	if [ "$(type -t "${function}")" = "function" ]; then
		return ${EXIT_TRUE}
	fi

	return ${EXIT_FALSE}
}

process_kill() {
	local process=${1}

	if ! isinteger process; then
		process=$(pidof ${process})
	fi

	local pid
	local sig
	for pid in ${process}; do
		for sig in 15 9; do
			[ -d "/proc/${pid}" ] || break

			kill -${sig} ${pid}
			sleep 1
		done
	done
}

dec() {
	local hex=${1}

	if [ "${hex:0:2}" != "0x" ]; then
		hex="0x${hex}"
	fi

	printf "%d\n" "${hex}"
}

chr() {
	local char="${1}"

	[ ${char} -lt 256 ] || return ${EXIT_ERROR}

	printf "\\$(( ${char} / 64 * 100 + ${char} % 64 / 8 * 10 + ${char} % 8 ))\n"
}

ord() {
	LC_CTYPE="C" printf "%d\n" "'${1}"
}

hex() {
	printf "%X\n" "${1}"
}

network_is_running() {
	# Check, if the network service is running.
	service_is_active network
}

contains_spaces() {
	local var="$@"

	# Eliminate spaces.
	local var2=${var// /}

	if [ ${#var} -ne ${#var2} ]; then
		return ${EXIT_TRUE}
	fi

	return ${EXIT_FALSE}
}

string_split() {
	local string="$@"

	local pos=0
	while [ ${pos} -lt ${#string} ]; do
		print "${string:${pos}:1}"
		pos=$(( ${pos} + 1 ))
	done

	return ${EXIT_OK}
}

string_reverse() {
	local string="$@"

	local output
	local pos=0
	while [ ${pos} -lt ${#string} ]; do
		output="${string:${pos}:1}${output}"
		pos=$(( ${pos} + 1 ))
	done

	print "${output}"
	return ${EXIT_OK}
}

dec2bin() {
	local number="${1}"

	local output

	local i div
	for i in 7 6 5 4 3 2 1; do
		div=$(( 2 ** ${i} ))

		if [ $(( ${number} / ${div} )) -eq 1 ]; then
			output="${output}1"
		else
			output="${output}0"
		fi
		number="$(( ${number} % ${div} ))"
	done

	if [ $(( ${number} % 2 )) -eq 1 ]; then
		output="${output}1"
	else
		output="${output}0"
	fi

	print "${output}"
}

bin2dec() {
	local string="${1}"
	local number=0

	local pos=0 char
	while [ ${pos} -lt ${#string} ]; do
		char="${string:${pos}:1}"
		pos=$(( ${pos} + 1 ))

		number=$(( ${number} << 1 ))

		case "${char}" in
			0) ;;
			1)
				number=$(( ${number} + 1 ))
				;;
			*)
				assert false "Invalid character: ${char}"
				;;
		esac
	done

	print "${number}"
	return ${EXIT_OK}
}

char2bin() {
	local dec="$(ord "${1}")"

	dec2bin "${dec}"
}

bin2char() {
	local dec="$(bin2dec "$@")"

	chr "${dec}"
}

bin2hex() {
	local dec="$(bin2dec "$@")"

	dec2hex "${dec}"
}

hex2bin() {
	local dec="$(hex2dec "$@")"

	dec2bin "${dec}"
}

hex2dec() {
	local hex="${1}"

	# Prepend 0x if necessary.
	[ "${hex:0:2}" = "0x" ] || hex="0x${hex}"

	printf "%d\n" "${hex}"
}

dec2hex() {
	printf "%02x\n" "${1}"
}