xref: /openbmc/linux/samples/bpf/xdp2skb_meta.sh (revision f220d3eb) 
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#
16BPF_FILE=xdp2skb_meta_kern.o
17DIR=$(dirname $0)
18
19[ -z "$TC" ] && TC=tc
20[ -z "$IP" ] && IP=ip
21
22function 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 --
34function err() {
35    local exitcode=$1
36    shift
37    echo "ERROR: $@" >&2
38    exit $exitcode
39}
40
41function info() {
42    if [[ -n "$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
51function _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 $@\""
66	fi
67    fi
68}
69function call_tc() {
70    _call_cmd "$TC" "" "$@"
71}
72function call_tc_allow_fail() {
73    _call_cmd "$TC" "allow_fail" "$@"
74}
75function call_ip() {
76    _call_cmd "$IP" "" "$@"
77}
78
79##  --- Parse command line arguments / parameters ---
80# Using external program "getopt" to get --long-options
81OPTIONS=$(getopt -o vfhd: \
82    --long verbose,flush,help,list,dev:,dry-run -- "$@")
83if (( $? != 0 )); then
84    err 4 "Error calling getopt"
85fi
86eval set -- "$OPTIONS"
87
88unset DEV
89unset FLUSH
90while 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=$VERBOSE" >&2
100	    shift
101	    ;;
102	--dry-run )
103	    DRYRUN=yes
104	    VERBOSE=yes
105	    info "Dry-run mode: enable VERBOSE and don't call TC+IP" >&2
106	    shift
107            ;;
108	-f | --flush )
109	    FLUSH=yes
110	    shift
111	    ;;
112	--list )
113	    LIST=yes
114	    shift
115	    ;;
116	-- )
117	    shift
118	    break
119	    ;;
120	-h | --help )
121	    usage;
122	    exit 0
123	    ;;
124	* )
125	    shift
126	    break
127	    ;;
128    esac
129done
130
131FILE="$DIR/$BPF_FILE"
132if [[ ! -e $FILE ]]; then
133    err 3 "Missing BPF object file ($FILE)"
134fi
135
136if [[ -z $DEV ]]; then
137    usage
138    err 2 "Please specify network device -- required option --dev"
139fi
140
141## -- Function calls --
142
143function 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
151function 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
159function 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
168function 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
176function 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
192function 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
207if [[ -n $FLUSH ]]; then
208    flush_tc  $DEV
209    flush_xdp $DEV
210    exit 0
211fi
212
213if [[ -n $LIST ]]; then
214    list_tc  $DEV
215    list_xdp $DEV
216    exit 0
217fi
218
219attach_tc_mark  $DEV $FILE
220attach_xdp_mark $DEV $FILE
221