Commit 6afb1e28 authored by William Tu's avatar William Tu Committed by David S. Miller
Browse files

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

samples/bpf/Makefile

+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

samples/bpf/bpf_helpers.h

+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

samples/bpf/tcbpf2_kern.c

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/* 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";

samples/bpf/test_tunnel_bpf.sh

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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"

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