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Commit 6afb1e28 authored by William Tu's avatar William Tu Committed by David S. Miller
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samples/bpf: Add tunnel set/get tests.



The patch creates sample code exercising bpf_skb_{set,get}_tunnel_key,
and bpf_skb_{set,get}_tunnel_opt for GRE, VXLAN, and GENEVE.  A native
tunnel device is created in a namespace to interact with a lwtunnel
device out of the namespace, with metadata enabled.  The bpf_skb_set_*
program is attached to tc egress and bpf_skb_get_* is attached to egress
qdisc.  A ping between two tunnels is used to verify correctness and
the result of bpf_skb_get_* printed by bpf_trace_printk.

Signed-off-by: default avatarWilliam Tu <u9012063@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c0b558e5
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+1 −0
Original line number Diff line number Diff line
@@ -67,6 +67,7 @@ always += tracex6_kern.o
always += test_probe_write_user_kern.o
always += trace_output_kern.o
always += tcbpf1_kern.o
always += tcbpf2_kern.o
always += lathist_kern.o
always += offwaketime_kern.o
always += spintest_kern.o
+8 −0
Original line number Diff line number Diff line
@@ -47,6 +47,14 @@ static int (*bpf_probe_write_user)(void *dst, void *src, int size) =
	(void *) BPF_FUNC_probe_write_user;
static int (*bpf_current_task_under_cgroup)(void *map, int index) =
	(void *) BPF_FUNC_current_task_under_cgroup;
static int (*bpf_skb_get_tunnel_key)(void *ctx, void *key, int size, int flags) =
	(void *) BPF_FUNC_skb_get_tunnel_key;
static int (*bpf_skb_set_tunnel_key)(void *ctx, void *key, int size, int flags) =
	(void *) BPF_FUNC_skb_set_tunnel_key;
static int (*bpf_skb_get_tunnel_opt)(void *ctx, void *md, int size) =
	(void *) BPF_FUNC_skb_get_tunnel_opt;
static int (*bpf_skb_set_tunnel_opt)(void *ctx, void *md, int size) =
	(void *) BPF_FUNC_skb_set_tunnel_opt;

/* llvm builtin functions that eBPF C program may use to
 * emit BPF_LD_ABS and BPF_LD_IND instructions
+191 −0
Original line number Diff line number Diff line
/* Copyright (c) 2016 VMware
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 */
#include <uapi/linux/bpf.h>
#include <uapi/linux/if_ether.h>
#include <uapi/linux/if_packet.h>
#include <uapi/linux/ip.h>
#include <uapi/linux/in.h>
#include <uapi/linux/tcp.h>
#include <uapi/linux/filter.h>
#include <uapi/linux/pkt_cls.h>
#include "bpf_helpers.h"

#define ERROR(ret) do {\
		char fmt[] = "ERROR line:%d ret:%d\n";\
		bpf_trace_printk(fmt, sizeof(fmt), __LINE__, ret); \
	} while(0)

struct geneve_opt {
	__be16	opt_class;
	u8	type;
	u8	length:5;
	u8	r3:1;
	u8	r2:1;
	u8	r1:1;
	u8	opt_data[8]; /* hard-coded to 8 byte */
};

struct vxlan_metadata {
	u32     gbp;
};

SEC("gre_set_tunnel")
int _gre_set_tunnel(struct __sk_buff *skb)
{
	int ret;
	struct bpf_tunnel_key key;

	__builtin_memset(&key, 0x0, sizeof(key));
	key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
	key.tunnel_id = 2;
	key.tunnel_tos = 0;
	key.tunnel_ttl = 64;

	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key), BPF_F_ZERO_CSUM_TX);
	if (ret < 0) {
		ERROR(ret);
		return TC_ACT_SHOT;
	}

	return TC_ACT_OK;
}

SEC("gre_get_tunnel")
int _gre_get_tunnel(struct __sk_buff *skb)
{
	int ret;
	struct bpf_tunnel_key key;
	char fmt[] = "key %d remote ip 0x%x\n";

	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
	if (ret < 0) {
		ERROR(ret);
		return TC_ACT_SHOT;
	}

	bpf_trace_printk(fmt, sizeof(fmt), key.tunnel_id, key.remote_ipv4);
	return TC_ACT_OK;
}

SEC("vxlan_set_tunnel")
int _vxlan_set_tunnel(struct __sk_buff *skb)
{
	int ret;
	struct bpf_tunnel_key key;
	struct vxlan_metadata md;

	__builtin_memset(&key, 0x0, sizeof(key));
	key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
	key.tunnel_id = 2;
	key.tunnel_tos = 0;
	key.tunnel_ttl = 64;

	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key), BPF_F_ZERO_CSUM_TX);
	if (ret < 0) {
		ERROR(ret);
		return TC_ACT_SHOT;
	}

	md.gbp = 0x800FF; /* Set VXLAN Group Policy extension */
	ret = bpf_skb_set_tunnel_opt(skb, &md, sizeof(md));
	if (ret < 0) {
		ERROR(ret);
		return TC_ACT_SHOT;
	}

	return TC_ACT_OK;
}

SEC("vxlan_get_tunnel")
int _vxlan_get_tunnel(struct __sk_buff *skb)
{
	int ret;
	struct bpf_tunnel_key key;
	struct vxlan_metadata md;
	char fmt[] = "key %d remote ip 0x%x vxlan gbp 0x%x\n";

	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
	if (ret < 0) {
		ERROR(ret);
		return TC_ACT_SHOT;
	}

	ret = bpf_skb_get_tunnel_opt(skb, &md, sizeof(md));
	if (ret < 0) {
		ERROR(ret);
		return TC_ACT_SHOT;
	}

	bpf_trace_printk(fmt, sizeof(fmt),
			key.tunnel_id, key.remote_ipv4, md.gbp);

	return TC_ACT_OK;
}

SEC("geneve_set_tunnel")
int _geneve_set_tunnel(struct __sk_buff *skb)
{
	int ret, ret2;
	struct bpf_tunnel_key key;
	struct geneve_opt gopt;

	__builtin_memset(&key, 0x0, sizeof(key));
	key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
	key.tunnel_id = 2;
	key.tunnel_tos = 0;
	key.tunnel_ttl = 64;

	__builtin_memset(&gopt, 0x0, sizeof(gopt));
	gopt.opt_class = 0x102; /* Open Virtual Networking (OVN) */
	gopt.type = 0x08;
	gopt.r1 = 1;
	gopt.r2 = 0;
	gopt.r3 = 1;
	gopt.length = 2; /* 4-byte multiple */
	*(int *) &gopt.opt_data = 0xdeadbeef;

	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key), BPF_F_ZERO_CSUM_TX);
	if (ret < 0) {
		ERROR(ret);
		return TC_ACT_SHOT;
	}

	ret = bpf_skb_set_tunnel_opt(skb, &gopt, sizeof(gopt));
	if (ret < 0) {
		ERROR(ret);
		return TC_ACT_SHOT;
	}

	return TC_ACT_OK;
}

SEC("geneve_get_tunnel")
int _geneve_get_tunnel(struct __sk_buff *skb)
{
	int ret;
	struct bpf_tunnel_key key;
	struct geneve_opt gopt;
	char fmt[] = "key %d remote ip 0x%x geneve class 0x%x\n";

	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
	if (ret < 0) {
		ERROR(ret);
		return TC_ACT_SHOT;
	}

	ret = bpf_skb_get_tunnel_opt(skb, &gopt, sizeof(gopt));
	if (ret < 0) {
		ERROR(ret);
		return TC_ACT_SHOT;
	}

	bpf_trace_printk(fmt, sizeof(fmt),
			key.tunnel_id, key.remote_ipv4, gopt.opt_class);
	return TC_ACT_OK;
}

char _license[] SEC("license") = "GPL";
+127 −0
Original line number Diff line number Diff line
#!/bin/bash
# In Namespace 0 (at_ns0) using native tunnel
# Overlay IP: 10.1.1.100
# local 192.16.1.100 remote 192.16.1.200
# veth0 IP: 172.16.1.100, tunnel dev <type>00

# Out of Namespace using BPF set/get on lwtunnel
# Overlay IP: 10.1.1.200
# local 172.16.1.200 remote 172.16.1.100
# veth1 IP: 172.16.1.200, tunnel dev <type>11

set -e

function config_device {
	ip netns add at_ns0
	ip link add veth0 type veth peer name veth1
	ip link set veth0 netns at_ns0
	ip netns exec at_ns0 ip addr add 172.16.1.100/24 dev veth0
	ip netns exec at_ns0 ip link set dev veth0 up
	ip link set dev veth1 up
	ip addr add dev veth1 172.16.1.200/24
}

function add_gre_tunnel {
	# in namespace
	ip netns exec at_ns0 \
		ip link add dev $DEV_NS type $TYPE key 2 local 172.16.1.100 remote 172.16.1.200
	ip netns exec at_ns0 ip link set dev $DEV_NS up
	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24

	# out of namespace
	ip link add dev $DEV type $TYPE key 2 external
	ip link set dev $DEV up
	ip addr add dev $DEV 10.1.1.200/24
}

function add_vxlan_tunnel {
	# Set static ARP entry here because iptables set-mark works
	# on L3 packet, as a result not applying to ARP packets,
	# causing errors at get_tunnel_{key/opt}.

	# in namespace
	ip netns exec at_ns0 \
		ip link add dev $DEV_NS type $TYPE id 2 dstport 4789 gbp remote 172.16.1.200
	ip netns exec at_ns0 ip link set dev $DEV_NS address 52:54:00:d9:01:00 up
	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
	ip netns exec at_ns0 arp -s 10.1.1.200 52:54:00:d9:02:00
	ip netns exec at_ns0 iptables -A OUTPUT -j MARK --set-mark 0x800FF

	# out of namespace
	ip link add dev $DEV type $TYPE external gbp dstport 4789
	ip link set dev $DEV address 52:54:00:d9:02:00 up
	ip addr add dev $DEV 10.1.1.200/24
	arp -s 10.1.1.100 52:54:00:d9:01:00
}

function add_geneve_tunnel {
	# in namespace
	ip netns exec at_ns0 \
		ip link add dev $DEV_NS type $TYPE id 2 dstport 6081 remote 172.16.1.200
	ip netns exec at_ns0 ip link set dev $DEV_NS up
	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24

	# out of namespace
	ip link add dev $DEV type $TYPE dstport 6081 external
	ip link set dev $DEV up
	ip addr add dev $DEV 10.1.1.200/24
}

function attach_bpf {
	DEV=$1
	SET_TUNNEL=$2
	GET_TUNNEL=$3
	tc qdisc add dev $DEV clsact
	tc filter add dev $DEV egress bpf da obj tcbpf2_kern.o sec $SET_TUNNEL
	tc filter add dev $DEV ingress bpf da obj tcbpf2_kern.o sec $GET_TUNNEL
}

function test_gre {
	TYPE=gretap
	DEV_NS=gretap00
	DEV=gretap11
	config_device
	add_gre_tunnel
	attach_bpf $DEV gre_set_tunnel gre_get_tunnel
	ping -c 1 10.1.1.100
	ip netns exec at_ns0 ping -c 1 10.1.1.200
}

function test_vxlan {
	TYPE=vxlan
	DEV_NS=vxlan00
	DEV=vxlan11
	config_device
	add_vxlan_tunnel
	attach_bpf $DEV vxlan_set_tunnel vxlan_get_tunnel
	ping -c 1 10.1.1.100
	ip netns exec at_ns0 ping -c 1 10.1.1.200
}

function test_geneve {
	TYPE=geneve
	DEV_NS=geneve00
	DEV=geneve11
	config_device
	add_geneve_tunnel
	attach_bpf $DEV geneve_set_tunnel geneve_get_tunnel
	ping -c 1 10.1.1.100
	ip netns exec at_ns0 ping -c 1 10.1.1.200
}

function cleanup {
	ip netns delete at_ns0
	ip link del veth1
	ip link del $DEV
}

echo "Testing GRE tunnel..."
test_gre
cleanup
echo "Testing VXLAN tunnel..."
test_vxlan
cleanup
echo "Testing GENEVE tunnel..."
test_geneve
cleanup
echo "Success"