meta-google: network-sh: Add library
Provides a utility for working with network type data. Right now this is
just for MAC address parsing and conversion to EUI{48,64}.
Change-Id: I49946d8147f1c7b10cfe3a9e55b20fc30c083eda
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/meta-google/recipes-google/networking/network-sh/lib.sh b/meta-google/recipes-google/networking/network-sh/lib.sh
new file mode 100644
index 0000000..f37f719
--- /dev/null
+++ b/meta-google/recipes-google/networking/network-sh/lib.sh
@@ -0,0 +1,106 @@
+#!/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[@]}"
+}
+
+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