samples/bpf/xdp2skb_meta.sh

   1 #!/bin/bash
   2 #
   3 # SPDX-License-Identifier: GPL-2.0
   4 # Copyright (c) 2018 Jesper Dangaard Brouer, Red Hat Inc.
   5 #
   6 # Bash-shell example on using iproute2 tools 'tc' and 'ip' to load
   7 # eBPF programs, both for XDP and clsbpf.  Shell script function
   8 # wrappers and even long options parsing is illustrated, for ease of
   9 # use.
  10 #
  11 # Related to sample/bpf/xdp2skb_meta_kern.c, which contains BPF-progs
  12 # that need to collaborate between XDP and TC hooks.  Thus, it is
  13 # convenient that the same tool load both programs that need to work
  14 # together.
  15 #
  16 BPF_FILE=xdp2skb_meta_kern.o
  17 DIR=$(dirname $0)
  18
  19 [ -z "$TC" ] && TC=tc
  20 [ -z "$IP" ] && IP=ip
  21
  22 function usage() {
  23     echo ""
  24     echo "Usage: $0 [-vfh] --dev ethX"
  25     echo "  -d | --dev     :             Network device (required)"
  26     echo "  --flush        :             Cleanup flush TC and XDP progs"
  27     echo "  --list         : (\$LIST)     List TC and XDP progs"
  28     echo "  -v | --verbose : (\$VERBOSE)  Verbose"
  29     echo "  --dry-run      : (\$DRYRUN)   Dry-run only (echo commands)"
  30     echo ""
  31 }
  32
  33 ## -- General shell logging cmds --
  34 function err() {
  35     local exitcode=$1
  36     shift
  37     echo "ERROR: $@" >&2
  38     exit $exitcode
  39 }
  40
  41 function info() {
  42     if [[ -n "$VERBOSE" ]]; then
  43         echo "# $@"
  44     fi
  45 }
  46
  47 ## -- Helper function calls --
  48
  49 # Wrapper call for TC and IP
  50 # - Will display the offending command on failure
  51 function _call_cmd() {
  52     local cmd="$1"
  53     local allow_fail="$2"
  54     shift 2
  55     if [[ -n "$VERBOSE" ]]; then
  56         echo "$cmd $@"
  57     fi
  58     if [[ -n "$DRYRUN" ]]; then
  59         return
  60     fi
  61     $cmd "$@"
  62     local status=$?
  63     if (( $status != 0 )); then
  64         if [[ "$allow_fail" == "" ]]; then
  65             err 2 "Exec error($status) occurred cmd: \"$cmd $@\""
  66         fi
  67     fi
  68 }
  69 function call_tc() {
  70     _call_cmd "$TC" "" "$@"
  71 }
  72 function call_tc_allow_fail() {
  73     _call_cmd "$TC" "allow_fail" "$@"
  74 }
  75 function call_ip() {
  76     _call_cmd "$IP" "" "$@"
  77 }
  78
  79 ##  --- Parse command line arguments / parameters ---
  80 # Using external program "getopt" to get --long-options
  81 OPTIONS=$(getopt -o vfhd: \
  82     --long verbose,flush,help,list,dev:,dry-run -- "$@")
  83 if (( $? != 0 )); then
  84     err 4 "Error calling getopt"
  85 fi
  86 eval set -- "$OPTIONS"
  87
  88 unset DEV
  89 unset FLUSH
  90 while true; do
  91     case "$1" in
  92         -d | --dev ) # device
  93             DEV=$2
  94             info "Device set to: DEV=$DEV" >&2
  95             shift 2
  96             ;;
  97         -v | --verbose)
  98             VERBOSE=yes
  99             # info "Verbose mode: VERBOSE=$VERBOSE" >&2
 100             shift
 101             ;;
 102         --dry-run )
 103             DRYRUN=yes
 104             VERBOSE=yes
 105             info "Dry-run mode: enable VERBOSE and don't call TC+IP" >&2
 106             shift
 107             ;;
 108         -f | --flush )
 109             FLUSH=yes
 110             shift
 111             ;;
 112         --list )
 113             LIST=yes
 114             shift
 115             ;;
 116         -- )
 117             shift
 118             break
 119             ;;
 120         -h | --help )
 121             usage;
 122             exit 0
 123             ;;
 124         * )
 125             shift
 126             break
 127             ;;
 128     esac
 129 done
 130
 131 FILE="$DIR/$BPF_FILE"
 132 if [[ ! -e $FILE ]]; then
 133     err 3 "Missing BPF object file ($FILE)"
 134 fi
 135
 136 if [[ -z $DEV ]]; then
 137     usage
 138     err 2 "Please specify network device -- required option --dev"
 139 fi
 140
 141 ## -- Function calls --
 142
 143 function list_tc()
 144 {
 145     local device="$1"
 146     shift
 147     info "Listing current TC ingress rules"
 148     call_tc filter show dev $device ingress
 149 }
 150
 151 function list_xdp()
 152 {
 153     local device="$1"
 154     shift
 155     info "Listing current XDP device($device) setting"
 156     call_ip link show dev $device | grep --color=auto xdp
 157 }
 158
 159 function flush_tc()
 160 {
 161     local device="$1"
 162     shift
 163     info "Flush TC on device: $device"
 164     call_tc_allow_fail filter del dev $device ingress
 165     call_tc_allow_fail qdisc del dev $device clsact
 166 }
 167
 168 function flush_xdp()
 169 {
 170     local device="$1"
 171     shift
 172     info "Flush XDP on device: $device"
 173     call_ip link set dev $device xdp off
 174 }
 175
 176 function attach_tc_mark()
 177 {
 178     local device="$1"
 179     local file="$2"
 180     local prog="tc_mark"
 181     shift 2
 182
 183     # Re-attach clsact to clear/flush existing role
 184     call_tc_allow_fail qdisc del dev $device clsact 2> /dev/null
 185     call_tc            qdisc add dev $device clsact
 186
 187     # Attach BPF prog
 188     call_tc filter add dev $device ingress \
 189             prio 1 handle 1 bpf da obj $file sec $prog
 190 }
 191
 192 function attach_xdp_mark()
 193 {
 194     local device="$1"
 195     local file="$2"
 196     local prog="xdp_mark"
 197     shift 2
 198
 199     # Remove XDP prog in-case it's already loaded
 200     # TODO: Need ip-link option to override/replace existing XDP prog
 201     flush_xdp $device
 202
 203     # Attach XDP/BPF prog
 204     call_ip link set dev $device xdp obj $file sec $prog
 205 }
 206
 207 if [[ -n $FLUSH ]]; then
 208     flush_tc  $DEV
 209     flush_xdp $DEV
 210     exit 0
 211 fi
 212
 213 if [[ -n $LIST ]]; then
 214     list_tc  $DEV
 215     list_xdp $DEV
 216     exit 0
 217 fi
 218
 219 attach_tc_mark  $DEV $FILE
 220 attach_xdp_mark $DEV $FILE