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Commit 7255fade authored by Willem de Bruijn's avatar Willem de Bruijn Committed by Alexei Starovoitov
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selftests/bpf: extend bpf tunnel test with gre 

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: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent ef81bd05
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Showing with 123 additions and 46 deletions
tools/testing/selftests/bpf/progs/test_tc_tunnel.c
View file @ 7255fade
......@@ -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")
......
tools/testing/selftests/bpf/test_tc_tunnel.sh
View file @ 7255fade
......@@ -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
......
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