selftests_bpf: add L2 encap to test_tc_tunnel

Update test_tc_tunnel to verify adding inner L2 header
encapsulation (an MPLS label or ethernet header) works.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Alan Maguire 2019-04-09 15:06:43 +01:00 committed by Daniel Borkmann
parent 1db04c300a
commit 3ec61df82b
3 changed files with 279 additions and 61 deletions

View file

@ -29,3 +29,7 @@ CONFIG_NET_FOU=m
CONFIG_NET_FOU_IP_TUNNELS=y
CONFIG_IPV6_FOU=m
CONFIG_IPV6_FOU_TUNNEL=m
CONFIG_MPLS=y
CONFIG_NET_MPLS_GSO=m
CONFIG_MPLS_ROUTING=m
CONFIG_MPLS_IPTUNNEL=m

View file

@ -11,6 +11,7 @@
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/mpls.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/pkt_cls.h>
@ -22,7 +23,14 @@
static const int cfg_port = 8000;
static const int cfg_udp_src = 20000;
static const int cfg_udp_dst = 5555;
#define UDP_PORT 5555
#define MPLS_OVER_UDP_PORT 6635
#define ETH_OVER_UDP_PORT 7777
/* 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);
struct gre_hdr {
__be16 flags;
@ -37,11 +45,13 @@ union l4hdr {
struct v4hdr {
struct iphdr ip;
union l4hdr l4hdr;
__u8 pad[16]; /* enough space for L2 header */
} __attribute__((packed));
struct v6hdr {
struct ipv6hdr ip;
union l4hdr l4hdr;
__u8 pad[16]; /* enough space for L2 header */
} __attribute__((packed));
static __always_inline void set_ipv4_csum(struct iphdr *iph)
@ -59,13 +69,15 @@ static __always_inline void set_ipv4_csum(struct iphdr *iph)
iph->check = ~((csum & 0xffff) + (csum >> 16));
}
static __always_inline int encap_ipv4(struct __sk_buff *skb, __u8 encap_proto)
static __always_inline int encap_ipv4(struct __sk_buff *skb, __u8 encap_proto,
__u16 l2_proto)
{
__u16 udp_dst = UDP_PORT;
struct iphdr iph_inner;
struct v4hdr h_outer;
struct tcphdr tcph;
int olen, l2_len;
__u64 flags;
int olen;
if (bpf_skb_load_bytes(skb, ETH_HLEN, &iph_inner,
sizeof(iph_inner)) < 0)
@ -83,23 +95,38 @@ static __always_inline int encap_ipv4(struct __sk_buff *skb, __u8 encap_proto)
return TC_ACT_OK;
olen = sizeof(h_outer.ip);
l2_len = 0;
flags = BPF_F_ADJ_ROOM_FIXED_GSO | BPF_F_ADJ_ROOM_ENCAP_L3_IPV4;
switch (l2_proto) {
case ETH_P_MPLS_UC:
l2_len = sizeof(mpls_label);
udp_dst = MPLS_OVER_UDP_PORT;
break;
case ETH_P_TEB:
l2_len = ETH_HLEN;
udp_dst = ETH_OVER_UDP_PORT;
break;
}
flags |= BPF_F_ADJ_ROOM_ENCAP_L2(l2_len);
switch (encap_proto) {
case IPPROTO_GRE:
flags |= BPF_F_ADJ_ROOM_ENCAP_L4_GRE;
olen += sizeof(h_outer.l4hdr.gre);
h_outer.l4hdr.gre.protocol = bpf_htons(ETH_P_IP);
h_outer.l4hdr.gre.protocol = bpf_htons(l2_proto);
h_outer.l4hdr.gre.flags = 0;
break;
case IPPROTO_UDP:
flags |= BPF_F_ADJ_ROOM_ENCAP_L4_UDP;
olen += sizeof(h_outer.l4hdr.udp);
h_outer.l4hdr.udp.source = __bpf_constant_htons(cfg_udp_src);
h_outer.l4hdr.udp.dest = __bpf_constant_htons(cfg_udp_dst);
h_outer.l4hdr.udp.dest = bpf_htons(udp_dst);
h_outer.l4hdr.udp.check = 0;
h_outer.l4hdr.udp.len = bpf_htons(bpf_ntohs(iph_inner.tot_len) +
sizeof(h_outer.l4hdr.udp));
sizeof(h_outer.l4hdr.udp) +
l2_len);
break;
case IPPROTO_IPIP:
break;
@ -107,6 +134,19 @@ static __always_inline int encap_ipv4(struct __sk_buff *skb, __u8 encap_proto)
return TC_ACT_OK;
}
/* add L2 encap (if specified) */
switch (l2_proto) {
case ETH_P_MPLS_UC:
*((__u32 *)((__u8 *)&h_outer + olen)) = mpls_label;
break;
case ETH_P_TEB:
if (bpf_skb_load_bytes(skb, 0, (__u8 *)&h_outer + olen,
ETH_HLEN))
return TC_ACT_SHOT;
break;
}
olen += l2_len;
/* add room between mac and network header */
if (bpf_skb_adjust_room(skb, olen, BPF_ADJ_ROOM_MAC, flags))
return TC_ACT_SHOT;
@ -127,14 +167,16 @@ static __always_inline int encap_ipv4(struct __sk_buff *skb, __u8 encap_proto)
return TC_ACT_OK;
}
static __always_inline int encap_ipv6(struct __sk_buff *skb, __u8 encap_proto)
static __always_inline int encap_ipv6(struct __sk_buff *skb, __u8 encap_proto,
__u16 l2_proto)
{
__u16 udp_dst = UDP_PORT;
struct ipv6hdr iph_inner;
struct v6hdr h_outer;
struct tcphdr tcph;
int olen, l2_len;
__u16 tot_len;
__u64 flags;
int olen;
if (bpf_skb_load_bytes(skb, ETH_HLEN, &iph_inner,
sizeof(iph_inner)) < 0)
@ -149,20 +191,34 @@ static __always_inline int encap_ipv6(struct __sk_buff *skb, __u8 encap_proto)
return TC_ACT_OK;
olen = sizeof(h_outer.ip);
l2_len = 0;
flags = BPF_F_ADJ_ROOM_FIXED_GSO | BPF_F_ADJ_ROOM_ENCAP_L3_IPV6;
switch (l2_proto) {
case ETH_P_MPLS_UC:
l2_len = sizeof(mpls_label);
udp_dst = MPLS_OVER_UDP_PORT;
break;
case ETH_P_TEB:
l2_len = ETH_HLEN;
udp_dst = ETH_OVER_UDP_PORT;
break;
}
flags |= BPF_F_ADJ_ROOM_ENCAP_L2(l2_len);
switch (encap_proto) {
case IPPROTO_GRE:
flags |= BPF_F_ADJ_ROOM_ENCAP_L4_GRE;
olen += sizeof(h_outer.l4hdr.gre);
h_outer.l4hdr.gre.protocol = bpf_htons(ETH_P_IPV6);
h_outer.l4hdr.gre.protocol = bpf_htons(l2_proto);
h_outer.l4hdr.gre.flags = 0;
break;
case IPPROTO_UDP:
flags |= BPF_F_ADJ_ROOM_ENCAP_L4_UDP;
olen += sizeof(h_outer.l4hdr.udp);
h_outer.l4hdr.udp.source = __bpf_constant_htons(cfg_udp_src);
h_outer.l4hdr.udp.dest = __bpf_constant_htons(cfg_udp_dst);
h_outer.l4hdr.udp.dest = bpf_htons(udp_dst);
tot_len = bpf_ntohs(iph_inner.payload_len) + sizeof(iph_inner) +
sizeof(h_outer.l4hdr.udp);
h_outer.l4hdr.udp.check = 0;
@ -174,6 +230,19 @@ static __always_inline int encap_ipv6(struct __sk_buff *skb, __u8 encap_proto)
return TC_ACT_OK;
}
/* add L2 encap (if specified) */
switch (l2_proto) {
case ETH_P_MPLS_UC:
*((__u32 *)((__u8 *)&h_outer + olen)) = mpls_label;
break;
case ETH_P_TEB:
if (bpf_skb_load_bytes(skb, 0, (__u8 *)&h_outer + olen,
ETH_HLEN))
return TC_ACT_SHOT;
break;
}
olen += l2_len;
/* add room between mac and network header */
if (bpf_skb_adjust_room(skb, olen, BPF_ADJ_ROOM_MAC, flags))
return TC_ACT_SHOT;
@ -193,56 +262,128 @@ static __always_inline int encap_ipv6(struct __sk_buff *skb, __u8 encap_proto)
return TC_ACT_OK;
}
SEC("encap_ipip")
int __encap_ipip(struct __sk_buff *skb)
SEC("encap_ipip_none")
int __encap_ipip_none(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IP))
return encap_ipv4(skb, IPPROTO_IPIP);
return encap_ipv4(skb, IPPROTO_IPIP, ETH_P_IP);
else
return TC_ACT_OK;
}
SEC("encap_gre")
int __encap_gre(struct __sk_buff *skb)
SEC("encap_gre_none")
int __encap_gre_none(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IP))
return encap_ipv4(skb, IPPROTO_GRE);
return encap_ipv4(skb, IPPROTO_GRE, ETH_P_IP);
else
return TC_ACT_OK;
}
SEC("encap_udp")
int __encap_udp(struct __sk_buff *skb)
SEC("encap_gre_mpls")
int __encap_gre_mpls(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IP))
return encap_ipv4(skb, IPPROTO_UDP);
return encap_ipv4(skb, IPPROTO_GRE, ETH_P_MPLS_UC);
else
return TC_ACT_OK;
}
SEC("encap_ip6tnl")
int __encap_ip6tnl(struct __sk_buff *skb)
SEC("encap_gre_eth")
int __encap_gre_eth(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6))
return encap_ipv6(skb, IPPROTO_IPV6);
if (skb->protocol == __bpf_constant_htons(ETH_P_IP))
return encap_ipv4(skb, IPPROTO_GRE, ETH_P_TEB);
else
return TC_ACT_OK;
}
SEC("encap_ip6gre")
int __encap_ip6gre(struct __sk_buff *skb)
SEC("encap_udp_none")
int __encap_udp_none(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6))
return encap_ipv6(skb, IPPROTO_GRE);
if (skb->protocol == __bpf_constant_htons(ETH_P_IP))
return encap_ipv4(skb, IPPROTO_UDP, ETH_P_IP);
else
return TC_ACT_OK;
}
SEC("encap_ip6udp")
int __encap_ip6udp(struct __sk_buff *skb)
SEC("encap_udp_mpls")
int __encap_udp_mpls(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IP))
return encap_ipv4(skb, IPPROTO_UDP, ETH_P_MPLS_UC);
else
return TC_ACT_OK;
}
SEC("encap_udp_eth")
int __encap_udp_eth(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IP))
return encap_ipv4(skb, IPPROTO_UDP, ETH_P_TEB);
else
return TC_ACT_OK;
}
SEC("encap_ip6tnl_none")
int __encap_ip6tnl_none(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6))
return encap_ipv6(skb, IPPROTO_UDP);
return encap_ipv6(skb, IPPROTO_IPV6, ETH_P_IPV6);
else
return TC_ACT_OK;
}
SEC("encap_ip6gre_none")
int __encap_ip6gre_none(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6))
return encap_ipv6(skb, IPPROTO_GRE, ETH_P_IPV6);
else
return TC_ACT_OK;
}
SEC("encap_ip6gre_mpls")
int __encap_ip6gre_mpls(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6))
return encap_ipv6(skb, IPPROTO_GRE, ETH_P_MPLS_UC);
else
return TC_ACT_OK;
}
SEC("encap_ip6gre_eth")
int __encap_ip6gre_eth(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6))
return encap_ipv6(skb, IPPROTO_GRE, ETH_P_TEB);
else
return TC_ACT_OK;
}
SEC("encap_ip6udp_none")
int __encap_ip6udp_none(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6))
return encap_ipv6(skb, IPPROTO_UDP, ETH_P_IPV6);
else
return TC_ACT_OK;
}
SEC("encap_ip6udp_mpls")
int __encap_ip6udp_mpls(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6))
return encap_ipv6(skb, IPPROTO_UDP, ETH_P_MPLS_UC);
else
return TC_ACT_OK;
}
SEC("encap_ip6udp_eth")
int __encap_ip6udp_eth(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6))
return encap_ipv6(skb, IPPROTO_UDP, ETH_P_TEB);
else
return TC_ACT_OK;
}
@ -250,6 +391,8 @@ int __encap_ip6udp(struct __sk_buff *skb)
static int decap_internal(struct __sk_buff *skb, int off, int len, char proto)
{
char buf[sizeof(struct v6hdr)];
struct gre_hdr greh;
struct udphdr udph;
int olen = len;
switch (proto) {
@ -258,9 +401,29 @@ static int decap_internal(struct __sk_buff *skb, int off, int len, char proto)
break;
case IPPROTO_GRE:
olen += sizeof(struct gre_hdr);
if (bpf_skb_load_bytes(skb, off + len, &greh, sizeof(greh)) < 0)
return TC_ACT_OK;
switch (bpf_ntohs(greh.protocol)) {
case ETH_P_MPLS_UC:
olen += sizeof(mpls_label);
break;
case ETH_P_TEB:
olen += ETH_HLEN;
break;
}
break;
case IPPROTO_UDP:
olen += sizeof(struct udphdr);
if (bpf_skb_load_bytes(skb, off + len, &udph, sizeof(udph)) < 0)
return TC_ACT_OK;
switch (bpf_ntohs(udph.dest)) {
case MPLS_OVER_UDP_PORT:
olen += sizeof(mpls_label);
break;
case ETH_OVER_UDP_PORT:
olen += ETH_HLEN;
break;
}
break;
default:
return TC_ACT_OK;

View file

@ -17,6 +17,9 @@ readonly ns2_v6=fd::2
# Must match port used by bpf program
readonly udpport=5555
# MPLSoverUDP
readonly mplsudpport=6635
readonly mplsproto=137
readonly infile="$(mktemp)"
readonly outfile="$(mktemp)"
@ -41,8 +44,8 @@ setup() {
# 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 1472 dev veth1
ip -netns "${ns1}" -6 route add "${ns2_v6}" mtu 1452 dev veth1
ip -netns "${ns1}" -4 route add "${ns2_v4}" mtu 1458 dev veth1
ip -netns "${ns1}" -6 route add "${ns2_v6}" mtu 1438 dev veth1
sleep 1
@ -89,42 +92,44 @@ set -e
# no arguments: automated test, run all
if [[ "$#" -eq "0" ]]; then
echo "ipip"
$0 ipv4 ipip 100
$0 ipv4 ipip none 100
echo "ip6ip6"
$0 ipv6 ip6tnl 100
$0 ipv6 ip6tnl none 100
echo "ip gre"
$0 ipv4 gre 100
for mac in none mpls eth ; do
echo "ip gre $mac"
$0 ipv4 gre $mac 100
echo "ip6 gre"
$0 ipv6 ip6gre 100
echo "ip6 gre $mac"
$0 ipv6 ip6gre $mac 100
echo "ip gre gso"
$0 ipv4 gre 2000
echo "ip gre $mac gso"
$0 ipv4 gre $mac 2000
echo "ip6 gre gso"
$0 ipv6 ip6gre 2000
echo "ip6 gre $mac gso"
$0 ipv6 ip6gre $mac 2000
echo "ip udp"
$0 ipv4 udp 100
echo "ip udp $mac"
$0 ipv4 udp $mac 100
echo "ip6 udp"
$0 ipv6 ip6udp 100
echo "ip6 udp $mac"
$0 ipv6 ip6udp $mac 100
echo "ip udp gso"
$0 ipv4 udp 2000
echo "ip udp $mac gso"
$0 ipv4 udp $mac 2000
echo "ip6 udp gso"
$0 ipv6 ip6udp 2000
echo "ip6 udp $mac gso"
$0 ipv6 ip6udp $mac 2000
done
echo "OK. All tests passed"
exit 0
fi
if [[ "$#" -ne "3" ]]; then
if [[ "$#" -ne "4" ]]; then
echo "Usage: $0"
echo " or: $0 <ipv4|ipv6> <tuntype> <data_len>"
echo " or: $0 <ipv4|ipv6> <tuntype> <none|mpls|eth> <data_len>"
exit 1
fi
@ -137,6 +142,8 @@ case "$1" in
readonly foumod=fou
readonly foutype=ipip
readonly fouproto=4
readonly fouproto_mpls=${mplsproto}
readonly gretaptype=gretap
;;
"ipv6")
readonly addr1="${ns1_v6}"
@ -146,6 +153,8 @@ case "$1" in
readonly foumod=fou6
readonly foutype=ip6tnl
readonly fouproto="41 -6"
readonly fouproto_mpls="${mplsproto} -6"
readonly gretaptype=ip6gretap
;;
*)
echo "unknown arg: $1"
@ -154,9 +163,10 @@ case "$1" in
esac
readonly tuntype=$2
readonly datalen=$3
readonly mac=$3
readonly datalen=$4
echo "encap ${addr1} to ${addr2}, type ${tuntype}, len ${datalen}"
echo "encap ${addr1} to ${addr2}, type ${tuntype}, mac ${mac} len ${datalen}"
trap cleanup EXIT
@ -173,7 +183,7 @@ verify_data
ip netns exec "${ns1}" tc qdisc add dev veth1 clsact
ip netns exec "${ns1}" tc filter add dev veth1 egress \
bpf direct-action object-file ./test_tc_tunnel.o \
section "encap_${tuntype}"
section "encap_${tuntype}_${mac}"
echo "test bpf encap without decap (expect failure)"
server_listen
! client_connect
@ -184,7 +194,18 @@ if [[ "$tuntype" =~ "udp" ]]; then
targs="encap fou encap-sport auto encap-dport $udpport"
# fou may be a module; allow this to fail.
modprobe "${foumod}" ||true
ip netns exec "${ns2}" ip fou add port 5555 ipproto ${fouproto}
if [[ "$mac" == "mpls" ]]; then
dport=${mplsudpport}
dproto=${fouproto_mpls}
tmode="mode any ttl 255"
else
dport=${udpport}
dproto=${fouproto}
fi
ip netns exec "${ns2}" ip fou add port $dport ipproto ${dproto}
targs="encap fou encap-sport auto encap-dport $dport"
elif [[ "$tuntype" =~ "gre" && "$mac" == "eth" ]]; then
ttype=$gretaptype
else
ttype=$tuntype
targs=""
@ -194,7 +215,31 @@ fi
# server is still running
# client can connect again
ip netns exec "${ns2}" ip link add name testtun0 type "${ttype}" \
remote "${addr1}" local "${addr2}" $targs
${tmode} remote "${addr1}" local "${addr2}" $targs
expect_tun_fail=0
if [[ "$tuntype" == "ip6udp" && "$mac" == "mpls" ]]; then
# No support for MPLS IPv6 fou tunnel; expect failure.
expect_tun_fail=1
elif [[ "$tuntype" =~ "udp" && "$mac" == "eth" ]]; then
# No support for TEB fou tunnel; expect failure.
expect_tun_fail=1
elif [[ "$tuntype" =~ "gre" && "$mac" == "eth" ]]; then
# Share ethernet address between tunnel/veth2 so L2 decap works.
ethaddr=$(ip netns exec "${ns2}" ip link show veth2 | \
awk '/ether/ { print $2 }')
ip netns exec "${ns2}" ip link set testtun0 address $ethaddr
elif [[ "$mac" == "mpls" ]]; then
modprobe mpls_iptunnel ||true
modprobe mpls_gso ||true
ip netns exec "${ns2}" sysctl -qw net.mpls.platform_labels=65536
ip netns exec "${ns2}" ip -f mpls route add 1000 dev lo
ip netns exec "${ns2}" ip link set lo up
ip netns exec "${ns2}" sysctl -qw net.mpls.conf.testtun0.input=1
ip netns exec "${ns2}" sysctl -qw net.ipv4.conf.lo.rp_filter=0
fi
# Because packets are decapped by the tunnel they arrive on testtun0 from
# the IP stack perspective. Ensure reverse path filtering is disabled
# otherwise we drop the TCP SYN as arriving on testtun0 instead of the
@ -204,16 +249,22 @@ ip netns exec "${ns2}" sysctl -qw net.ipv4.conf.all.rp_filter=0
# selected as the max of the "all" and device-specific values.
ip netns exec "${ns2}" sysctl -qw net.ipv4.conf.testtun0.rp_filter=0
ip netns exec "${ns2}" ip link set dev testtun0 up
echo "test bpf encap with tunnel device decap"
client_connect
verify_data
if [[ "$expect_tun_fail" == 1 ]]; then
# This tunnel mode is not supported, so we expect failure.
echo "test bpf encap with tunnel device decap (expect failure)"
! client_connect
else
echo "test bpf encap with tunnel device decap"
client_connect
verify_data
server_listen
fi
# serverside, use BPF for decap
ip netns exec "${ns2}" ip link del dev testtun0
ip netns exec "${ns2}" tc qdisc add dev veth2 clsact
ip netns exec "${ns2}" tc filter add dev veth2 ingress \
bpf direct-action object-file ./test_tc_tunnel.o section decap
server_listen
echo "test bpf encap with bpf decap"
client_connect
verify_data