Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 94f16813 authored by Willem de Bruijn's avatar Willem de Bruijn Committed by Alexei Starovoitov
Browse files

selftests/bpf: convert bpf tunnel test to BPF_F_ADJ_ROOM_FIXED_GSO 



Lower route MTU to ensure packets fit in device MTU after encap, then
skip the gso_size changes.

Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 005edd16

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

+8 −3
Original line number Diff line number Diff line
@@ -52,6 +52,7 @@ static __always_inline int encap_ipv4(struct __sk_buff *skb, bool with_gre) 
	struct grev4hdr h_outer;

	struct iphdr iph_inner;

	struct tcphdr tcph;

	__u64 flags;

	int olen;



	if (bpf_skb_load_bytes(skb, ETH_HLEN, &iph_inner,
@@ -69,10 +70,11 @@ static __always_inline int encap_ipv4(struct __sk_buff *skb, bool with_gre) 
	if (tcph.dest != __bpf_constant_htons(cfg_port))

		return TC_ACT_OK;



	flags = BPF_F_ADJ_ROOM_FIXED_GSO;

	olen = with_gre ? sizeof(h_outer) : sizeof(h_outer.ip);



	/* add room between mac and network header */

	if (bpf_skb_adjust_room(skb, olen, BPF_ADJ_ROOM_MAC, 0))

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

		return TC_ACT_SHOT;



	/* prepare new outer network header */
@@ -102,6 +104,7 @@ static __always_inline int encap_ipv6(struct __sk_buff *skb, bool with_gre) 
	struct ipv6hdr iph_inner;

	struct grev6hdr h_outer;

	struct tcphdr tcph;

	__u64 flags;

	int olen;



	if (bpf_skb_load_bytes(skb, ETH_HLEN, &iph_inner,
@@ -116,10 +119,11 @@ static __always_inline int encap_ipv6(struct __sk_buff *skb, bool with_gre) 
	if (tcph.dest != __bpf_constant_htons(cfg_port))

		return TC_ACT_OK;



	flags = BPF_F_ADJ_ROOM_FIXED_GSO;

	olen = with_gre ? sizeof(h_outer) : sizeof(h_outer.ip);



	/* add room between mac and network header */

	if (bpf_skb_adjust_room(skb, olen, BPF_ADJ_ROOM_MAC, 0))

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

		return TC_ACT_SHOT;



	/* prepare new outer network header */
@@ -195,7 +199,8 @@ 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, 0))

	if (bpf_skb_adjust_room(skb, -olen, BPF_ADJ_ROOM_MAC,

				BPF_F_ADJ_ROOM_FIXED_GSO))

		return TC_ACT_SHOT;



	return TC_ACT_OK;

tools/testing/selftests/bpf/test_tc_tunnel.sh

+6 −0
Original line number Diff line number Diff line
@@ -35,6 +35,12 @@ setup() { 
	ip -netns "${ns1}" -6 addr add "${ns1_v6}/64" dev veth1 nodad

	ip -netns "${ns2}" -6 addr add "${ns2_v6}/64" dev veth2 nodad



	# clamp route to reserve room for tunnel headers

	ip -netns "${ns1}" -4 route flush table main

	ip -netns "${ns1}" -6 route flush table main

	ip -netns "${ns1}" -4 route add "${ns2_v4}" mtu 1476 dev veth1

	ip -netns "${ns1}" -6 route add "${ns2_v6}" mtu 1456 dev veth1



	sleep 1



	dd if=/dev/urandom of="${infile}" bs="${datalen}" count=1 status=none