linux/samples/bpf/xdp2skb_meta.sh

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#!/bin/bash
#
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2018 Jesper Dangaard Brouer, Red Hat Inc.
#
# Bash-shell example on using iproute2 tools 'tc' and 'ip' to load
# eBPF programs, both for XDP and clsbpf. Shell script function
# wrappers and even long options parsing is illustrated, for ease of
# use.
#
# Related to sample/bpf/xdp2skb_meta_kern.c, which contains BPF-progs
# that need to collaborate between XDP and TC hooks. Thus, it is
# convenient that the same tool load both programs that need to work
# together.
#
BPF_FILE=xdp2skb_meta_kern.o
DIR=$(dirname $0)
export TC=/usr/sbin/tc
export IP=/usr/sbin/ip
function usage() {
echo ""
echo "Usage: $0 [-vfh] --dev ethX"
echo " -d | --dev : Network device (required)"
echo " --flush : Cleanup flush TC and XDP progs"
echo " --list : (\$LIST) List TC and XDP progs"
echo " -v | --verbose : (\$VERBOSE) Verbose"
echo " --dry-run : (\$DRYRUN) Dry-run only (echo commands)"
echo ""
}
## -- General shell logging cmds --
function err() {
local exitcode=$1
shift
echo "ERROR: $@" >&2
exit $exitcode
}
function info() {
if [[ -n "$VERBOSE" ]]; then
echo "# $@"
fi
}
## -- Helper function calls --
# Wrapper call for TC and IP
# - Will display the offending command on failure
function _call_cmd() {
local cmd="$1"
local allow_fail="$2"
shift 2
if [[ -n "$VERBOSE" ]]; then
echo "$(basename $cmd) $@"
fi
if [[ -n "$DRYRUN" ]]; then
return
fi
$cmd "$@"
local status=$?
if (( $status != 0 )); then
if [[ "$allow_fail" == "" ]]; then
err 2 "Exec error($status) occurred cmd: \"$cmd $@\""
fi
fi
}
function call_tc() {
_call_cmd "$TC" "" "$@"
}
function call_tc_allow_fail() {
_call_cmd "$TC" "allow_fail" "$@"
}
function call_ip() {
_call_cmd "$IP" "" "$@"
}
## --- Parse command line arguments / parameters ---
# Using external program "getopt" to get --long-options
OPTIONS=$(getopt -o vfhd: \
--long verbose,flush,help,list,dev:,dry-run -- "$@")
if (( $? != 0 )); then
err 4 "Error calling getopt"
fi
eval set -- "$OPTIONS"
unset DEV
unset FLUSH
while true; do
case "$1" in
-d | --dev ) # device
DEV=$2
info "Device set to: DEV=$DEV" >&2
shift 2
;;
-v | --verbose)
VERBOSE=yes
# info "Verbose mode: VERBOSE=$VERBOSE" >&2
shift
;;
--dry-run )
DRYRUN=yes
VERBOSE=yes
info "Dry-run mode: enable VERBOSE and don't call TC+IP" >&2
shift
;;
-f | --flush )
FLUSH=yes
shift
;;
--list )
LIST=yes
shift
;;
-- )
shift
break
;;
-h | --help )
usage;
exit 0
;;
* )
shift
break
;;
esac
done
FILE="$DIR/$BPF_FILE"
if [[ ! -e $FILE ]]; then
err 3 "Missing BPF object file ($FILE)"
fi
if [[ -z $DEV ]]; then
usage
err 2 "Please specify network device -- required option --dev"
fi
## -- Function calls --
function list_tc()
{
local device="$1"
shift
info "Listing current TC ingress rules"
call_tc filter show dev $device ingress
}
function list_xdp()
{
local device="$1"
shift
info "Listing current XDP device($device) setting"
call_ip link show dev $device | grep --color=auto xdp
}
function flush_tc()
{
local device="$1"
shift
info "Flush TC on device: $device"
call_tc_allow_fail filter del dev $device ingress
call_tc_allow_fail qdisc del dev $device clsact
}
function flush_xdp()
{
local device="$1"
shift
info "Flush XDP on device: $device"
call_ip link set dev $device xdp off
}
function attach_tc_mark()
{
local device="$1"
local file="$2"
local prog="tc_mark"
shift 2
# Re-attach clsact to clear/flush existing role
call_tc_allow_fail qdisc del dev $device clsact 2> /dev/null
call_tc qdisc add dev $device clsact
# Attach BPF prog
call_tc filter add dev $device ingress \
prio 1 handle 1 bpf da obj $file sec $prog
}
function attach_xdp_mark()
{
local device="$1"
local file="$2"
local prog="xdp_mark"
shift 2
# Remove XDP prog in-case it's already loaded
# TODO: Need ip-link option to override/replace existing XDP prog
flush_xdp $device
# Attach XDP/BPF prog
call_ip link set dev $device xdp obj $file sec $prog
}
if [[ -n $FLUSH ]]; then
flush_tc $DEV
flush_xdp $DEV
exit 0
fi
if [[ -n $LIST ]]; then
list_tc $DEV
list_xdp $DEV
exit 0
fi
attach_tc_mark $DEV $FILE
attach_xdp_mark $DEV $FILE