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#!/bin/bash
set -eu
# Copyright: 2018 1&1 IONOS Cloud GmbH
# Authors: Daniel Swarbrick <daniel.swarbrick@cloud.ionos.com>
# Benjamin Drung <benjamin.drung@cloud.ionos.com>
#
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
CONFIGFS_PATH=/sys/kernel/config
NETCONSOLE_PATH=$CONFIGFS_PATH/netconsole
is_ip_address() {
local address="$1"
local returncode=1
# Check for IPv4 or IPv6 address
if [[ "$address" =~ ^([0-9]{1,3}\.){3}[0-9]{1,3}|([0-9a-fA-F]{0,4}:){1,7}[0-9a-fA-F]{0,4}$ ]]; then
returncode=0
fi
return "$returncode"
}
ip_to_mac() {
local address="$1"
local from_interface="$2"
mac=$(ip -o neigh show to "$address" dev "$from_interface" | grep -oE "lladdr [^ ]*" | cut -d ' ' -f 2)
if test -z "$mac"; then
# Run arping to determine the MAC address for the given IP address
if arping -V 2>/dev/null | grep -q iputils; then
# iputils' arping
mac=$(arping -c 1 -f -I "$from_interface" "$address" | sed -n 's/^.* reply from [^ ]* \[\(.*\)\].*$/\1/p' | head -n 1)
mac="${mac,,}"
else
# Assume Thomas Habet's arping
mac=$(arping -c 1 -i "$from_interface" -r "$address" | head -n 1)
fi
fi
echo "$mac"
}
if test "$#" -eq 0; then
echo "${0##*/}: No target specified. Doing nothing." >&2
exit 0
fi
if [ ! -d $CONFIGFS_PATH ]; then
echo "${0##*/}: Kernel config directory $CONFIGFS_PATH not present." >&2
echo "${0##*/}: Loading kernel module 'configfs'..." >&2
modprobe configfs
if command -v udevadm >/dev/null 2>&1; then
udevadm settle
fi
fi
if ! mount | grep -qw "$CONFIGFS_PATH"; then
echo "${0##*/}: configfs not mounted to '$CONFIGFS_PATH'; mounting configfs..." >&2
mount -t configfs configfs $CONFIGFS_PATH
fi
if [ ! -d $NETCONSOLE_PATH ]; then
if modprobe -n --first-time netconsole >/dev/null 2>&1; then
echo "${0##*/}: Loading kernel module 'netconsole'..." >&2
modprobe netconsole
else
echo "${0##*/}: Error: netconsole dynamic config directory '$NETCONSOLE_PATH' not present." >&2
exit 1
fi
fi
for option in "$@"; do
if [[ "$option" =~ ^((\+)?([0-9]+)?@)?(.+)$ ]]; then
if test "${BASH_REMATCH[2]}" = "+"; then
extended=1
else
extended=0
fi
remote_port=${BASH_REMATCH[3]}
target=${BASH_REMATCH[4]}
else
echo "${0##*/}: Failed to parse option '$option'. Expected format: [[+][target-port]@]target-host" >&2
continue
fi
target_path=$NETCONSOLE_PATH/$target
if is_ip_address "$target"; then
to_ip="$target"
else
to_ip=$(LANG=C getent hosts -- "$target" | grep -oE "^([0-9a-fA-F.:]+)" || true)
fi
if test -z "$to_ip"; then
echo "${0##*/}: Skipped host '$target'. No IP found for it." >&2
continue
fi
route=$(ip -o route get "$to_ip")
from_interface=$(echo "$route" | grep -oE "dev [^ ]*" | cut -d ' ' -f 2)
from_ip=$(echo "$route" | grep -oE "src [^ ]*" | cut -d ' ' -f 2)
to_gateway=$(echo "$route" | grep -oE "via [^ ]*" | cut -d ' ' -f 2)
if test -z "$to_gateway"; then
# If there is no "via" in the output of the ip route lookup, then the packets will
# be sent directory to the target (without any additional hops)
to_gateway=$to_ip
fi
to_mac=$(ip_to_mac "$to_gateway" "$from_interface")
if test -z "$to_mac"; then
echo "${0##*/}: $target: Cannot resolve MAC address of $to_gateway." >&2
exit 1
fi
mkdir -p "$target_path"
declare -A changes=( [dev_name]="$from_interface" [local_ip]="$from_ip"
[remote_ip]="$to_ip" [remote_mac]="$to_mac" [extended]="$extended" )
if test -n "$remote_port"; then
changes[remote_port]="$remote_port"
fi
for config in "${!changes[@]}"; do
if test "$(cat "$target_path/$config")" = "${changes[$config]}"; then
# Setting already in the correct state
unset "changes[$config]"
fi
done
enabled=$(cat "$target_path/enabled")
if test "${#changes[@]}" -eq 0 && test "$enabled" -eq 1; then
echo "${0##*/}: $target already configured correctly." >&2
else
echo "${0##*/}: $target: Configure sending logs to $to_ip via MAC $to_mac from $from_ip on interface '$from_interface'." >&2
if test "$enabled" -ne 0; then
echo 0 > "$target_path/enabled"
fi
for config in "${!changes[@]}"; do
echo "${changes[$config]}" > "$target_path/$config"
done
echo 1 > "$target_path/enabled"
fi
done
# shellcheck disable=SC2034
read -r console_log_level default_log_level minimum_log_level maximum_log_level < /proc/sys/kernel/printk
log_level=$(( console_log_level > minimum_log_level ? console_log_level - 1 : console_log_level ))
echo "<${log_level}>${0##*/}: Test log message to verify netconsole configuration." > /dev/kmsg
|
