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Message-Id: <20190320144944.147862-6-willemdebruijn.kernel@gmail.com>
Date: Wed, 20 Mar 2019 10:49:36 -0400
From: Willem de Bruijn <willemdebruijn.kernel@...il.com>
To: netdev@...r.kernel.org
Cc: ast@...nel.org, daniel@...earbox.net, sdf@...gle.com,
posk@...gle.com, Willem de Bruijn <willemb@...gle.com>
Subject: [PATCH bpf-next 05/13] selftests/bpf: extend bpf tunnel test with gre
From: Willem de Bruijn <willemb@...gle.com>
GRE is a commonly used protocol. Add GRE cases for both IPv4 and IPv6.
It also inserts different sized headers, which can expose some
unexpected edge cases.
Signed-off-by: Willem de Bruijn <willemb@...gle.com>
---
.../selftests/bpf/progs/test_tc_tunnel.c | 148 +++++++++++++-----
tools/testing/selftests/bpf/test_tc_tunnel.sh | 21 ++-
2 files changed, 123 insertions(+), 46 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/test_tc_tunnel.c b/tools/testing/selftests/bpf/progs/test_tc_tunnel.c
index 591f540ce513d..900c5653105fe 100644
--- a/tools/testing/selftests/bpf/progs/test_tc_tunnel.c
+++ b/tools/testing/selftests/bpf/progs/test_tc_tunnel.c
@@ -2,6 +2,9 @@
/* In-place tunneling */
+#include <stdbool.h>
+#include <string.h>
+
#include <linux/stddef.h>
#include <linux/bpf.h>
#include <linux/if_ether.h>
@@ -17,6 +20,18 @@
static const int cfg_port = 8000;
+struct grev4hdr {
+ struct iphdr ip;
+ __be16 flags;
+ __be16 protocol;
+} __attribute__((packed));
+
+struct grev6hdr {
+ struct ipv6hdr ip;
+ __be16 flags;
+ __be16 protocol;
+} __attribute__((packed));
+
static __always_inline void set_ipv4_csum(struct iphdr *iph)
{
__u16 *iph16 = (__u16 *)iph;
@@ -32,10 +47,12 @@ static __always_inline void set_ipv4_csum(struct iphdr *iph)
iph->check = ~((csum & 0xffff) + (csum >> 16));
}
-static int encap_ipv4(struct __sk_buff *skb)
+static __always_inline int encap_ipv4(struct __sk_buff *skb, bool with_gre)
{
- struct iphdr iph_outer, iph_inner;
+ struct grev4hdr h_outer;
+ struct iphdr iph_inner;
struct tcphdr tcph;
+ int olen;
if (bpf_skb_load_bytes(skb, ETH_HLEN, &iph_inner,
sizeof(iph_inner)) < 0)
@@ -52,24 +69,33 @@ static int encap_ipv4(struct __sk_buff *skb)
if (tcph.dest != __bpf_constant_htons(cfg_port))
return TC_ACT_OK;
+ olen = with_gre ? sizeof(h_outer) : sizeof(h_outer.ip);
+
/* add room between mac and network header */
- if (bpf_skb_adjust_room(skb, sizeof(iph_outer), BPF_ADJ_ROOM_NET, 0))
+ if (bpf_skb_adjust_room(skb, olen, BPF_ADJ_ROOM_NET, 0))
return TC_ACT_SHOT;
/* prepare new outer network header */
- iph_outer = iph_inner;
- iph_outer.protocol = IPPROTO_IPIP;
- iph_outer.tot_len = bpf_htons(sizeof(iph_outer) +
- bpf_htons(iph_outer.tot_len));
- set_ipv4_csum(&iph_outer);
+ h_outer.ip = iph_inner;
+ h_outer.ip.tot_len = bpf_htons(olen +
+ bpf_htons(h_outer.ip.tot_len));
+ if (with_gre) {
+ h_outer.ip.protocol = IPPROTO_GRE;
+ h_outer.protocol = bpf_htons(ETH_P_IP);
+ h_outer.flags = 0;
+ } else {
+ h_outer.ip.protocol = IPPROTO_IPIP;
+ }
+
+ set_ipv4_csum((void *)&h_outer.ip);
/* store new outer network header */
- if (bpf_skb_store_bytes(skb, ETH_HLEN, &iph_outer, sizeof(iph_outer),
+ if (bpf_skb_store_bytes(skb, ETH_HLEN, &h_outer, olen,
BPF_F_INVALIDATE_HASH) < 0)
return TC_ACT_SHOT;
/* bpf_skb_adjust_room has moved header to start of room: restore */
- if (bpf_skb_store_bytes(skb, ETH_HLEN + sizeof(iph_outer),
+ if (bpf_skb_store_bytes(skb, ETH_HLEN + olen,
&iph_inner, sizeof(iph_inner),
BPF_F_INVALIDATE_HASH) < 0)
return TC_ACT_SHOT;
@@ -77,10 +103,12 @@ static int encap_ipv4(struct __sk_buff *skb)
return TC_ACT_OK;
}
-static int encap_ipv6(struct __sk_buff *skb)
+static __always_inline int encap_ipv6(struct __sk_buff *skb, bool with_gre)
{
- struct ipv6hdr iph_outer, iph_inner;
+ struct ipv6hdr iph_inner;
+ struct grev6hdr h_outer;
struct tcphdr tcph;
+ int olen;
if (bpf_skb_load_bytes(skb, ETH_HLEN, &iph_inner,
sizeof(iph_inner)) < 0)
@@ -94,23 +122,31 @@ static int encap_ipv6(struct __sk_buff *skb)
if (tcph.dest != __bpf_constant_htons(cfg_port))
return TC_ACT_OK;
+ olen = with_gre ? sizeof(h_outer) : sizeof(h_outer.ip);
+
/* add room between mac and network header */
- if (bpf_skb_adjust_room(skb, sizeof(iph_outer), BPF_ADJ_ROOM_NET, 0))
+ if (bpf_skb_adjust_room(skb, olen, BPF_ADJ_ROOM_NET, 0))
return TC_ACT_SHOT;
/* prepare new outer network header */
- iph_outer = iph_inner;
- iph_outer.nexthdr = IPPROTO_IPV6;
- iph_outer.payload_len = bpf_htons(sizeof(iph_outer) +
- bpf_ntohs(iph_outer.payload_len));
+ h_outer.ip = iph_inner;
+ h_outer.ip.payload_len = bpf_htons(olen +
+ bpf_ntohs(h_outer.ip.payload_len));
+ if (with_gre) {
+ h_outer.ip.nexthdr = IPPROTO_GRE;
+ h_outer.protocol = bpf_htons(ETH_P_IPV6);
+ h_outer.flags = 0;
+ } else {
+ h_outer.ip.nexthdr = IPPROTO_IPV6;
+ }
/* store new outer network header */
- if (bpf_skb_store_bytes(skb, ETH_HLEN, &iph_outer, sizeof(iph_outer),
+ if (bpf_skb_store_bytes(skb, ETH_HLEN, &h_outer, olen,
BPF_F_INVALIDATE_HASH) < 0)
return TC_ACT_SHOT;
/* bpf_skb_adjust_room has moved header to start of room: restore */
- if (bpf_skb_store_bytes(skb, ETH_HLEN + sizeof(iph_outer),
+ if (bpf_skb_store_bytes(skb, ETH_HLEN + olen,
&iph_inner, sizeof(iph_inner),
BPF_F_INVALIDATE_HASH) < 0)
return TC_ACT_SHOT;
@@ -118,28 +154,63 @@ static int encap_ipv6(struct __sk_buff *skb)
return TC_ACT_OK;
}
-SEC("encap")
-int encap_f(struct __sk_buff *skb)
+SEC("encap_ipip")
+int __encap_ipip(struct __sk_buff *skb)
{
- switch (skb->protocol) {
- case __bpf_constant_htons(ETH_P_IP):
- return encap_ipv4(skb);
- case __bpf_constant_htons(ETH_P_IPV6):
- return encap_ipv6(skb);
- default:
- /* does not match, ignore */
+ if (skb->protocol == __bpf_constant_htons(ETH_P_IP))
+ return encap_ipv4(skb, false);
+ else
return TC_ACT_OK;
- }
}
-static int decap_internal(struct __sk_buff *skb, int off, int len)
+SEC("encap_gre")
+int __encap_gre(struct __sk_buff *skb)
{
- char buf[sizeof(struct ipv6hdr)];
+ if (skb->protocol == __bpf_constant_htons(ETH_P_IP))
+ return encap_ipv4(skb, true);
+ else
+ return TC_ACT_OK;
+}
- if (bpf_skb_load_bytes(skb, off + len, &buf, len) < 0)
+SEC("encap_ip6tnl")
+int __encap_ip6tnl(struct __sk_buff *skb)
+{
+ if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6))
+ return encap_ipv6(skb, false);
+ else
+ return TC_ACT_OK;
+}
+
+SEC("encap_ip6gre")
+int __encap_ip6gre(struct __sk_buff *skb)
+{
+ if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6))
+ return encap_ipv6(skb, true);
+ else
return TC_ACT_OK;
+}
- if (bpf_skb_adjust_room(skb, -len, BPF_ADJ_ROOM_NET, 0))
+static int decap_internal(struct __sk_buff *skb, int off, int len, char proto)
+{
+ char buf[sizeof(struct grev6hdr)];
+ int olen;
+
+ switch (proto) {
+ case IPPROTO_IPIP:
+ case IPPROTO_IPV6:
+ olen = len;
+ break;
+ case IPPROTO_GRE:
+ olen = len + 4 /* gre hdr */;
+ break;
+ default:
+ return TC_ACT_OK;
+ }
+
+ if (bpf_skb_load_bytes(skb, off + olen, &buf, olen) < 0)
+ return TC_ACT_OK;
+
+ if (bpf_skb_adjust_room(skb, -olen, BPF_ADJ_ROOM_NET, 0))
return TC_ACT_SHOT;
/* bpf_skb_adjust_room has moved outer over inner header: restore */
@@ -157,10 +228,11 @@ static int decap_ipv4(struct __sk_buff *skb)
sizeof(iph_outer)) < 0)
return TC_ACT_OK;
- if (iph_outer.ihl != 5 || iph_outer.protocol != IPPROTO_IPIP)
+ if (iph_outer.ihl != 5)
return TC_ACT_OK;
- return decap_internal(skb, ETH_HLEN, sizeof(iph_outer));
+ return decap_internal(skb, ETH_HLEN, sizeof(iph_outer),
+ iph_outer.protocol);
}
static int decap_ipv6(struct __sk_buff *skb)
@@ -171,10 +243,8 @@ static int decap_ipv6(struct __sk_buff *skb)
sizeof(iph_outer)) < 0)
return TC_ACT_OK;
- if (iph_outer.nexthdr != IPPROTO_IPV6)
- return TC_ACT_OK;
-
- return decap_internal(skb, ETH_HLEN, sizeof(iph_outer));
+ return decap_internal(skb, ETH_HLEN, sizeof(iph_outer),
+ iph_outer.nexthdr);
}
SEC("decap")
diff --git a/tools/testing/selftests/bpf/test_tc_tunnel.sh b/tools/testing/selftests/bpf/test_tc_tunnel.sh
index 7b1758f3006b0..c78922048610b 100755
--- a/tools/testing/selftests/bpf/test_tc_tunnel.sh
+++ b/tools/testing/selftests/bpf/test_tc_tunnel.sh
@@ -54,30 +54,36 @@ set -e
# no arguments: automated test, run all
if [[ "$#" -eq "0" ]]; then
echo "ipip"
- $0 ipv4
+ $0 ipv4 ipip
echo "ip6ip6"
- $0 ipv6
+ $0 ipv6 ip6tnl
+
+ echo "ip gre"
+ $0 ipv4 gre
+
+ echo "ip6 gre"
+ $0 ipv6 ip6gre
echo "OK. All tests passed"
exit 0
fi
-if [[ "$#" -ne "1" ]]; then
+if [[ "$#" -ne "2" ]]; then
echo "Usage: $0"
- echo " or: $0 <ipv4|ipv6>"
+ echo " or: $0 <ipv4|ipv6> <tuntype>"
exit 1
fi
case "$1" in
"ipv4")
- readonly tuntype=ipip
+ readonly tuntype=$2
readonly addr1="${ns1_v4}"
readonly addr2="${ns2_v4}"
readonly netcat_opt=-4
;;
"ipv6")
- readonly tuntype=ip6tnl
+ readonly tuntype=$2
readonly addr1="${ns1_v6}"
readonly addr2="${ns2_v6}"
readonly netcat_opt=-6
@@ -103,7 +109,8 @@ client_connect
# client can no longer connect
ip netns exec "${ns1}" tc qdisc add dev veth1 clsact
ip netns exec "${ns1}" tc filter add dev veth1 egress \
- bpf direct-action object-file ./test_tc_tunnel.o section encap
+ bpf direct-action object-file ./test_tc_tunnel.o \
+ section "encap_${tuntype}"
echo "test bpf encap without decap (expect failure)"
server_listen
! client_connect
--
2.21.0.225.g810b269d1ac-goog
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