Commit 7105f76f authored by Ziyang Xuan's avatar Ziyang Xuan Committed by Martin KaFai Lau
Browse files

selftests/bpf: add ipip6 and ip6ip decap to test_tc_tunnel 



Add ipip6 and ip6ip decap testcases. Verify that bpf_skb_adjust_room()
correctly decapsulate ipip6 and ip6ip tunnel packets.

Signed-off-by: default avatarZiyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: default avatarWillem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/dfd2d8cfdf9111bd129170d4345296f53bee6a67.1673574419.git.william.xuanziyang@huawei.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent d219df60

tools/testing/selftests/bpf/progs/test_tc_tunnel.c

+89 −2
Original line number Diff line number Diff line
@@ -38,6 +38,10 @@ static const int cfg_udp_src = 20000; 
#define	VXLAN_FLAGS     0x8

#define	VXLAN_VNI       1



#ifndef NEXTHDR_DEST

#define NEXTHDR_DEST	60

#endif



/* MPLS label 1000 with S bit (last label) set and ttl of 255. */

static const __u32 mpls_label = __bpf_constant_htonl(1000 << 12 |

						     MPLS_LS_S_MASK | 0xff);
@@ -363,6 +367,61 @@ static __always_inline int __encap_ipv6(struct __sk_buff *skb, __u8 encap_proto, 
	return TC_ACT_OK;

}



static int encap_ipv6_ipip6(struct __sk_buff *skb)

{

	struct iphdr iph_inner;

	struct v6hdr h_outer;

	struct tcphdr tcph;

	struct ethhdr eth;

	__u64 flags;

	int olen;



	if (bpf_skb_load_bytes(skb, ETH_HLEN, &iph_inner,

			       sizeof(iph_inner)) < 0)

		return TC_ACT_OK;



	/* filter only packets we want */

	if (bpf_skb_load_bytes(skb, ETH_HLEN + (iph_inner.ihl << 2),

			       &tcph, sizeof(tcph)) < 0)

		return TC_ACT_OK;



	if (tcph.dest != __bpf_constant_htons(cfg_port))

		return TC_ACT_OK;



	olen = sizeof(h_outer.ip);



	flags = BPF_F_ADJ_ROOM_FIXED_GSO | BPF_F_ADJ_ROOM_ENCAP_L3_IPV6;



	/* add room between mac and network header */

	if (bpf_skb_adjust_room(skb, olen, BPF_ADJ_ROOM_MAC, flags))

		return TC_ACT_SHOT;



	/* prepare new outer network header */

	memset(&h_outer.ip, 0, sizeof(h_outer.ip));

	h_outer.ip.version = 6;

	h_outer.ip.hop_limit = iph_inner.ttl;

	h_outer.ip.saddr.s6_addr[1] = 0xfd;

	h_outer.ip.saddr.s6_addr[15] = 1;

	h_outer.ip.daddr.s6_addr[1] = 0xfd;

	h_outer.ip.daddr.s6_addr[15] = 2;

	h_outer.ip.payload_len = iph_inner.tot_len;

	h_outer.ip.nexthdr = IPPROTO_IPIP;



	/* store new outer network header */

	if (bpf_skb_store_bytes(skb, ETH_HLEN, &h_outer, olen,

				BPF_F_INVALIDATE_HASH) < 0)

		return TC_ACT_SHOT;



	/* update eth->h_proto */

	if (bpf_skb_load_bytes(skb, 0, &eth, sizeof(eth)) < 0)

		return TC_ACT_SHOT;

	eth.h_proto = bpf_htons(ETH_P_IPV6);

	if (bpf_skb_store_bytes(skb, 0, &eth, sizeof(eth), 0) < 0)

		return TC_ACT_SHOT;



	return TC_ACT_OK;

}



static __always_inline int encap_ipv6(struct __sk_buff *skb, __u8 encap_proto,

				      __u16 l2_proto)

{
@@ -461,6 +520,15 @@ int __encap_ip6tnl_none(struct __sk_buff *skb) 
		return TC_ACT_OK;

}



SEC("encap_ipip6_none")

int __encap_ipip6_none(struct __sk_buff *skb)

{

	if (skb->protocol == __bpf_constant_htons(ETH_P_IP))

		return encap_ipv6_ipip6(skb);

	else

		return TC_ACT_OK;

}



SEC("encap_ip6gre_none")

int __encap_ip6gre_none(struct __sk_buff *skb)

{
@@ -528,13 +596,33 @@ int __encap_ip6vxlan_eth(struct __sk_buff *skb) 


static int decap_internal(struct __sk_buff *skb, int off, int len, char proto)

{

	__u64 flags = BPF_F_ADJ_ROOM_FIXED_GSO;

	struct ipv6_opt_hdr ip6_opt_hdr;

	struct gre_hdr greh;

	struct udphdr udph;

	int olen = len;



	switch (proto) {

	case IPPROTO_IPIP:

		flags |= BPF_F_ADJ_ROOM_DECAP_L3_IPV4;

		break;

	case IPPROTO_IPV6:

		flags |= BPF_F_ADJ_ROOM_DECAP_L3_IPV6;

		break;

	case NEXTHDR_DEST:

		if (bpf_skb_load_bytes(skb, off + len, &ip6_opt_hdr,

				       sizeof(ip6_opt_hdr)) < 0)

			return TC_ACT_OK;

		switch (ip6_opt_hdr.nexthdr) {

		case IPPROTO_IPIP:

			flags |= BPF_F_ADJ_ROOM_DECAP_L3_IPV4;

			break;

		case IPPROTO_IPV6:

			flags |= BPF_F_ADJ_ROOM_DECAP_L3_IPV6;

			break;

		default:

			return TC_ACT_OK;

		}

		break;

	case IPPROTO_GRE:

		olen += sizeof(struct gre_hdr);
@@ -569,8 +657,7 @@ static int decap_internal(struct __sk_buff *skb, int off, int len, char proto) 
		return TC_ACT_OK;

	}



	if (bpf_skb_adjust_room(skb, -olen, BPF_ADJ_ROOM_MAC,

				BPF_F_ADJ_ROOM_FIXED_GSO))

	if (bpf_skb_adjust_room(skb, -olen, BPF_ADJ_ROOM_MAC, flags))

		return TC_ACT_SHOT;



	return TC_ACT_OK;

tools/testing/selftests/bpf/test_tc_tunnel.sh

+9 −6
Original line number Diff line number Diff line
@@ -100,6 +100,9 @@ if [[ "$#" -eq "0" ]]; then 
	echo "ipip"

	$0 ipv4 ipip none 100



	echo "ipip6"

	$0 ipv4 ipip6 none 100



	echo "ip6ip6"

	$0 ipv6 ip6tnl none 100
@@ -224,6 +227,9 @@ elif [[ "$tuntype" =~ "gre" && "$mac" == "eth" ]]; then 
elif [[ "$tuntype" =~ "vxlan" && "$mac" == "eth" ]]; then

	ttype="vxlan"

	targs="id 1 dstport 8472 udp6zerocsumrx"

elif [[ "$tuntype" == "ipip6" ]]; then

	ttype="ip6tnl"

	targs=""

else

	ttype=$tuntype

	targs=""
@@ -233,6 +239,9 @@ fi 
if [[ "${tuntype}" == "sit" ]]; then

	link_addr1="${ns1_v4}"

	link_addr2="${ns2_v4}"

elif [[ "${tuntype}" == "ipip6" ]]; then

	link_addr1="${ns1_v6}"

	link_addr2="${ns2_v6}"

else

	link_addr1="${addr1}"

	link_addr2="${addr2}"
@@ -287,12 +296,6 @@ else 
	server_listen

fi



# bpf_skb_net_shrink does not take tunnel flags yet, cannot update L3.

if [[ "${tuntype}" == "sit" ]]; then

	echo OK

	exit 0

fi



# serverside, use BPF for decap

ip netns exec "${ns2}" ip link del dev testtun0

ip netns exec "${ns2}" tc qdisc add dev veth2 clsact