From 94f16813e1b297d31f8fe6217cd9be19e080f998 Mon Sep 17 00:00:00 2001
From: Willem de Bruijn <willemb@google.com>
Date: Fri, 22 Mar 2019 14:32:59 -0400
Subject: [PATCH] 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: Willem de Bruijn <willemb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
tools/testing/selftests/bpf/progs/test_tc_tunnel.c | 11 ++++++++---
tools/testing/selftests/bpf/test_tc_tunnel.sh | 6 ++++++
2 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/test_tc_tunnel.c b/tools/testing/selftests/bpf/progs/test_tc_tunnel.c
index f6a16fd23dbd5..3b79dffb81037 100644
--- a/tools/testing/selftests/bpf/progs/test_tc_tunnel.c
+++ b/tools/testing/selftests/bpf/progs/test_tc_tunnel.c
@@ -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;
diff --git a/tools/testing/selftests/bpf/test_tc_tunnel.sh b/tools/testing/selftests/bpf/test_tc_tunnel.sh
index 9e18754f23547..cda5317790d24 100755
--- a/tools/testing/selftests/bpf/test_tc_tunnel.sh
+++ b/tools/testing/selftests/bpf/test_tc_tunnel.sh
@@ -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
--
2.30.2