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#!/bin/bash
# Copyright 2021 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
[ -n "${network_init-}" ] && return
mac_to_bytes() {
local -n bytes="$1"
local str="$2"
# Verify that the MAC is Valid
[[ "$str" =~ ^[[:xdigit:]]{1,2}(:[[:xdigit:]]{1,2}){5}$ ]] || return
# Split the mac into hex bytes
local oldifs="$IFS"
IFS=:
local byte
for byte in $str; do
bytes+=(0x$byte)
done
IFS="$oldifs"
}
mac_to_eui48() {
local mac_bytes=()
mac_to_bytes mac_bytes "$1" || return
# Return the EUI-64 bytes in the IPv6 format
printf '%02x%02x:%02x%02x:%02x%02x\n' "${mac_bytes[@]}"
}
mac_to_eui64() {
local mac_bytes=()
mac_to_bytes mac_bytes "$1" || return
# Using EUI-64 conversion rules, create the suffix bytes from MAC bytes
# Invert bit-0 of the first byte, and insert 0xfffe in the middle.
local suffix_bytes=(
$((mac_bytes[0] ^ 1))
${mac_bytes[@]:1:2}
$((0xff)) $((0xfe))
${mac_bytes[@]:3:3}
)
# Return the EUI-64 bytes in the IPv6 format
printf '%02x%02x:%02x%02x:%02x%02x:%02x%02x\n' "${suffix_bytes[@]}"
}
ip_to_bytes() {
local -n bytes_out="$1"
local str="$2"
local bytes=()
local oldifs="$IFS"
# Heuristic for V4 / V6, validity will be checked as it is parsed
if [[ "$str" == *.* ]]; then
# Ensure we don't start or end with IFS
[ "${str:0:1}" != '.' ] || return 1
[ "${str: -1}" != '.' ] || return 1
local v
# Split IPv4 address into octets
IFS=.
for v in $str; do
# IPv4 digits are always decimal numbers
if ! [[ "$v" =~ ^[0-9]+$ ]]; then
IFS="$oldifs"
return 1
fi
# Each octet is a single byte, make sure the number isn't larger
if (( v > 0xff )); then
IFS="$oldifs"
return 1
fi
bytes+=($v)
done
# IPv4 addresses must have all 4 bytes present
if (( "${#bytes[@]}" != 4 )); then
IFS="$oldifs"
return 1
fi
else
# Ensure we bound the padding in an outer byte for
# IFS splitting to work correctly
[ "${str:0:2}" = '::' ] && str="0$str"
[ "${str: -2}" = '::' ] && str="${str}0"
# Ensure we don't start or end with IFS
[ "${str:0:1}" != ':' ] || return 1
[ "${str: -1}" != ':' ] || return 1
# Stores the bytes that come before ::, if it exists
local bytesBeforePad=()
local v
# Split the Address into hextets
IFS=:
for v in $str; do
# Handle ::, which translates to an empty string
if [ -z "$v" ]; then
# Only allow a single :: sequence in an address
if (( "${#bytesBeforePad[@]}" > 0 )); then
IFS="$oldifs"
return 1
fi
# Store the already parsed upper bytes separately
# This allows us to calculate and insert padding
bytesBeforePad=("${bytes[@]}")
bytes=()
continue
fi
# IPv6 digits are always hex
if ! [[ "$v" =~ ^[[:xdigit:]]+$ ]]; then
IFS="$oldifs"
return 1
fi
# Ensure the number is no larger than a hextet
v="0x$v"
if (( v > 0xffff )); then
IFS="$oldifs"
return 1
fi
# Split the hextet into 2 bytes
bytes+=($(( v >> 8 )))
bytes+=($(( v & 0xff )))
done
# If we have ::, add padding
if (( "${#bytesBeforePad[@]}" > 0 )); then
# Fill the middle bytes with padding and store in `bytes`
while (( "${#bytes[@]}" + "${#bytesBeforePad[@]}" < 16 )); do
bytesBeforePad+=(0)
done
bytes=("${bytesBeforePad[@]}" "${bytes[@]}")
fi
# IPv6 addresses must have all 16 bytes present
if (( "${#bytes[@]}" != 16 )); then
IFS="$oldifs"
return 1
fi
fi
IFS="$oldifs"
bytes_out=("${bytes[@]}")
}
ipv6_pfx_concat() {
local pfx="$1"
local sfx="$2"
# Validate the prefix
if ! [[ "$pfx" =~ ^(([0-9a-fA-F]{1,4}:)+):/([0-9]+)$ ]]; then
echo "Invalid IPv6 prefix: $pfx" >&2
return 1
fi
local addr="${BASH_REMATCH[1]}"
local cidr="${BASH_REMATCH[3]}"
# Ensure prefix doesn't have too many bytes
local nos="${addr//:/}"
if (( ${#addr} - ${#nos} > (cidr+7)/16 )); then
echo "Too many prefix bytes: $pfx" >&2
return 1
fi
# Validate the suffix
if ! [[ "$sfx" =~ ^[0-9a-fA-F]{1,4}(:[0-9a-fA-F]{1,4})*$ ]]; then
echo "Invalid IPv6 suffix: $sfx" >&2
return 1
fi
# Ensure suffix doesn't have too many bytes
local nos="${sfx//:/}"
if (( ${#sfx} - ${#nos} >= (128-cidr)/16 )); then
echo "Too many suffix bytes: $sfx" >&2
return 1
fi
local comb="$addr:$sfx"
local nos="${comb//:/}"
if (( ${#comb} - ${#nos} == 8 )); then
comb="$addr$sfx"
fi
echo "$comb/$cidr"
}
ipv6_pfx_to_cidr() {
[[ "$1" =~ ^[0-9a-fA-F:]+/([0-9]+)$ ]] || return
echo "${BASH_REMATCH[1]}"
}
network_init=1
return 0 2>/dev/null
echo "network is a library, not executed directly" >&2
exit 1
|
