forked from Minki/linux
selftests: bpf: tc-bpf flow shaping with EDT
Add a small test that shows how to shape a TCP flow in tc-bpf with EDT and ECN. Signed-off-by: Peter Oskolkov <posk@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Peter Oskolkov
Alexei Starovoitov
parent
315a202987
commit
7df5e3db8f
@ -53,7 +53,8 @@ TEST_PROGS := test_kmod.sh \
|
||||
test_xdp_vlan.sh \
|
||||
test_lwt_ip_encap.sh \
|
||||
test_tcp_check_syncookie.sh \
|
||||
test_tc_tunnel.sh
|
||||
test_tc_tunnel.sh \
|
||||
test_tc_edt.sh
|
||||
|
||||
TEST_PROGS_EXTENDED := with_addr.sh \
|
||||
with_tunnels.sh \
|
||||
|
||||
109
tools/testing/selftests/bpf/progs/test_tc_edt.c
Normal file
109
tools/testing/selftests/bpf/progs/test_tc_edt.c
Normal file
@ -0,0 +1,109 @@
|
||||
// SPDX-License-Identifier: GPL-2.0
|
||||
#include <stdint.h>
|
||||
#include <linux/bpf.h>
|
||||
#include <linux/if_ether.h>
|
||||
#include <linux/in.h>
|
||||
#include <linux/ip.h>
|
||||
#include <linux/pkt_cls.h>
|
||||
#include <linux/tcp.h>
|
||||
#include "bpf_helpers.h"
|
||||
#include "bpf_endian.h"
|
||||
|
||||
/* the maximum delay we are willing to add (drop packets beyond that) */
|
||||
#define TIME_HORIZON_NS (2000 * 1000 * 1000)
|
||||
#define NS_PER_SEC 1000000000
|
||||
#define ECN_HORIZON_NS 5000000
|
||||
#define THROTTLE_RATE_BPS (5 * 1000 * 1000)
|
||||
|
||||
/* flow_key => last_tstamp timestamp used */
|
||||
struct bpf_map_def SEC("maps") flow_map = {
|
||||
.type = BPF_MAP_TYPE_HASH,
|
||||
.key_size = sizeof(uint32_t),
|
||||
.value_size = sizeof(uint64_t),
|
||||
.max_entries = 1,
|
||||
};
|
||||
|
||||
static inline int throttle_flow(struct __sk_buff *skb)
|
||||
{
|
||||
int key = 0;
|
||||
uint64_t *last_tstamp = bpf_map_lookup_elem(&flow_map, &key);
|
||||
uint64_t delay_ns = ((uint64_t)skb->len) * NS_PER_SEC /
|
||||
THROTTLE_RATE_BPS;
|
||||
uint64_t now = bpf_ktime_get_ns();
|
||||
uint64_t tstamp, next_tstamp = 0;
|
||||
|
||||
if (last_tstamp)
|
||||
next_tstamp = *last_tstamp + delay_ns;
|
||||
|
||||
tstamp = skb->tstamp;
|
||||
if (tstamp < now)
|
||||
tstamp = now;
|
||||
|
||||
/* should we throttle? */
|
||||
if (next_tstamp <= tstamp) {
|
||||
if (bpf_map_update_elem(&flow_map, &key, &tstamp, BPF_ANY))
|
||||
return TC_ACT_SHOT;
|
||||
return TC_ACT_OK;
|
||||
}
|
||||
|
||||
/* do not queue past the time horizon */
|
||||
if (next_tstamp - now >= TIME_HORIZON_NS)
|
||||
return TC_ACT_SHOT;
|
||||
|
||||
/* set ecn bit, if needed */
|
||||
if (next_tstamp - now >= ECN_HORIZON_NS)
|
||||
bpf_skb_ecn_set_ce(skb);
|
||||
|
||||
if (bpf_map_update_elem(&flow_map, &key, &next_tstamp, BPF_EXIST))
|
||||
return TC_ACT_SHOT;
|
||||
skb->tstamp = next_tstamp;
|
||||
|
||||
return TC_ACT_OK;
|
||||
}
|
||||
|
||||
static inline int handle_tcp(struct __sk_buff *skb, struct tcphdr *tcp)
|
||||
{
|
||||
void *data_end = (void *)(long)skb->data_end;
|
||||
|
||||
/* drop malformed packets */
|
||||
if ((void *)(tcp + 1) > data_end)
|
||||
return TC_ACT_SHOT;
|
||||
|
||||
if (tcp->dest == bpf_htons(9000))
|
||||
return throttle_flow(skb);
|
||||
|
||||
return TC_ACT_OK;
|
||||
}
|
||||
|
||||
static inline int handle_ipv4(struct __sk_buff *skb)
|
||||
{
|
||||
void *data_end = (void *)(long)skb->data_end;
|
||||
void *data = (void *)(long)skb->data;
|
||||
struct iphdr *iph;
|
||||
uint32_t ihl;
|
||||
|
||||
/* drop malformed packets */
|
||||
if (data + sizeof(struct ethhdr) > data_end)
|
||||
return TC_ACT_SHOT;
|
||||
iph = (struct iphdr *)(data + sizeof(struct ethhdr));
|
||||
if ((void *)(iph + 1) > data_end)
|
||||
return TC_ACT_SHOT;
|
||||
ihl = iph->ihl * 4;
|
||||
if (((void *)iph) + ihl > data_end)
|
||||
return TC_ACT_SHOT;
|
||||
|
||||
if (iph->protocol == IPPROTO_TCP)
|
||||
return handle_tcp(skb, (struct tcphdr *)(((void *)iph) + ihl));
|
||||
|
||||
return TC_ACT_OK;
|
||||
}
|
||||
|
||||
SEC("cls_test") int tc_prog(struct __sk_buff *skb)
|
||||
{
|
||||
if (skb->protocol == bpf_htons(ETH_P_IP))
|
||||
return handle_ipv4(skb);
|
||||
|
||||
return TC_ACT_OK;
|
||||
}
|
||||
|
||||
char __license[] SEC("license") = "GPL";
|
||||
99
tools/testing/selftests/bpf/test_tc_edt.sh
Executable file
99
tools/testing/selftests/bpf/test_tc_edt.sh
Executable file
@ -0,0 +1,99 @@
|
||||
#!/bin/bash
|
||||
# SPDX-License-Identifier: GPL-2.0
|
||||
#
|
||||
# This test installs a TC bpf program that throttles a TCP flow
|
||||
# with dst port = 9000 down to 5MBps. Then it measures actual
|
||||
# throughput of the flow.
|
||||
|
||||
if [[ $EUID -ne 0 ]]; then
|
||||
echo "This script must be run as root"
|
||||
echo "FAIL"
|
||||
exit 1
|
||||
fi
|
||||
|
||||
# check that nc, dd, and timeout are present
|
||||
command -v nc >/dev/null 2>&1 || \
|
||||
{ echo >&2 "nc is not available"; exit 1; }
|
||||
command -v dd >/dev/null 2>&1 || \
|
||||
{ echo >&2 "nc is not available"; exit 1; }
|
||||
command -v timeout >/dev/null 2>&1 || \
|
||||
{ echo >&2 "timeout is not available"; exit 1; }
|
||||
|
||||
readonly NS_SRC="ns-src-$(mktemp -u XXXXXX)"
|
||||
readonly NS_DST="ns-dst-$(mktemp -u XXXXXX)"
|
||||
|
||||
readonly IP_SRC="172.16.1.100"
|
||||
readonly IP_DST="172.16.2.100"
|
||||
|
||||
cleanup()
|
||||
{
|
||||
ip netns del ${NS_SRC}
|
||||
ip netns del ${NS_DST}
|
||||
}
|
||||
|
||||
trap cleanup EXIT
|
||||
|
||||
set -e # exit on error
|
||||
|
||||
ip netns add "${NS_SRC}"
|
||||
ip netns add "${NS_DST}"
|
||||
ip link add veth_src type veth peer name veth_dst
|
||||
ip link set veth_src netns ${NS_SRC}
|
||||
ip link set veth_dst netns ${NS_DST}
|
||||
|
||||
ip -netns ${NS_SRC} addr add ${IP_SRC}/24 dev veth_src
|
||||
ip -netns ${NS_DST} addr add ${IP_DST}/24 dev veth_dst
|
||||
|
||||
ip -netns ${NS_SRC} link set dev veth_src up
|
||||
ip -netns ${NS_DST} link set dev veth_dst up
|
||||
|
||||
ip -netns ${NS_SRC} route add ${IP_DST}/32 dev veth_src
|
||||
ip -netns ${NS_DST} route add ${IP_SRC}/32 dev veth_dst
|
||||
|
||||
# set up TC on TX
|
||||
ip netns exec ${NS_SRC} tc qdisc add dev veth_src root fq
|
||||
ip netns exec ${NS_SRC} tc qdisc add dev veth_src clsact
|
||||
ip netns exec ${NS_SRC} tc filter add dev veth_src egress \
|
||||
bpf da obj test_tc_edt.o sec cls_test
|
||||
|
||||
|
||||
# start the listener
|
||||
ip netns exec ${NS_DST} bash -c \
|
||||
"nc -4 -l -s ${IP_DST} -p 9000 >/dev/null &"
|
||||
declare -i NC_PID=$!
|
||||
sleep 1
|
||||
|
||||
declare -ir TIMEOUT=20
|
||||
declare -ir EXPECTED_BPS=5000000
|
||||
|
||||
# run the load, capture RX bytes on DST
|
||||
declare -ir RX_BYTES_START=$( ip netns exec ${NS_DST} \
|
||||
cat /sys/class/net/veth_dst/statistics/rx_bytes )
|
||||
|
||||
set +e
|
||||
ip netns exec ${NS_SRC} bash -c "timeout ${TIMEOUT} dd if=/dev/zero \
|
||||
bs=1000 count=1000000 > /dev/tcp/${IP_DST}/9000 2>/dev/null"
|
||||
set -e
|
||||
|
||||
declare -ir RX_BYTES_END=$( ip netns exec ${NS_DST} \
|
||||
cat /sys/class/net/veth_dst/statistics/rx_bytes )
|
||||
|
||||
declare -ir ACTUAL_BPS=$(( ($RX_BYTES_END - $RX_BYTES_START) / $TIMEOUT ))
|
||||
|
||||
echo $TIMEOUT $ACTUAL_BPS $EXPECTED_BPS | \
|
||||
awk '{printf "elapsed: %d sec; bps difference: %.2f%%\n",
|
||||
$1, ($2-$3)*100.0/$3}'
|
||||
|
||||
# Pass the test if the actual bps is within 1% of the expected bps.
|
||||
# The difference is usually about 0.1% on a 20-sec test, and ==> zero
|
||||
# the longer the test runs.
|
||||
declare -ir RES=$( echo $ACTUAL_BPS $EXPECTED_BPS | \
|
||||
awk 'function abs(x){return ((x < 0.0) ? -x : x)}
|
||||
{if (abs(($1-$2)*100.0/$2) > 1.0) { print "1" }
|
||||
else { print "0"} }' )
|
||||
if [ "${RES}" == "0" ] ; then
|
||||
echo "PASS"
|
||||
else
|
||||
echo "FAIL"
|
||||
exit 1
|
||||
fi
|
||||
Loading…
Reference in New Issue
Block a user