selftests_bpf: extend test_tc_tunnel for UDP encap

commit 868d523535 ("bpf: add bpf_skb_adjust_room encap flags")
introduced support to bpf_skb_adjust_room for GSO-friendly GRE
and UDP encapsulation and later introduced associated test_tc_tunnel
tests.  Here those tests are extended to cover UDP encapsulation also.

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 15:06:40 +01:00 committed by Daniel Borkmann
parent c695865c5c
commit 166b5a7f2c
3 changed files with 145 additions and 50 deletions

View File

@ -25,3 +25,7 @@ CONFIG_XDP_SOCKETS=y
CONFIG_FTRACE_SYSCALLS=y
CONFIG_IPV6_TUNNEL=y
CONFIG_IPV6_GRE=y
CONFIG_NET_FOU=m
CONFIG_NET_FOU_IP_TUNNELS=y
CONFIG_IPV6_FOU=m
CONFIG_IPV6_FOU_TUNNEL=m

View File

@ -12,6 +12,7 @@
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/pkt_cls.h>
#include <linux/types.h>
@ -20,16 +21,27 @@
static const int cfg_port = 8000;
struct grev4hdr {
struct iphdr ip;
static const int cfg_udp_src = 20000;
static const int cfg_udp_dst = 5555;
struct gre_hdr {
__be16 flags;
__be16 protocol;
} __attribute__((packed));
struct grev6hdr {
union l4hdr {
struct udphdr udp;
struct gre_hdr gre;
};
struct v4hdr {
struct iphdr ip;
union l4hdr l4hdr;
} __attribute__((packed));
struct v6hdr {
struct ipv6hdr ip;
__be16 flags;
__be16 protocol;
union l4hdr l4hdr;
} __attribute__((packed));
static __always_inline void set_ipv4_csum(struct iphdr *iph)
@ -47,10 +59,10 @@ 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, bool with_gre)
static __always_inline int encap_ipv4(struct __sk_buff *skb, __u8 encap_proto)
{
struct grev4hdr h_outer;
struct iphdr iph_inner;
struct v4hdr h_outer;
struct tcphdr tcph;
__u64 flags;
int olen;
@ -70,12 +82,29 @@ 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;
olen = sizeof(h_outer.ip);
flags = BPF_F_ADJ_ROOM_FIXED_GSO | BPF_F_ADJ_ROOM_ENCAP_L3_IPV4;
if (with_gre) {
switch (encap_proto) {
case IPPROTO_GRE:
flags |= BPF_F_ADJ_ROOM_ENCAP_L4_GRE;
olen = sizeof(h_outer);
} else {
olen = sizeof(h_outer.ip);
olen += sizeof(h_outer.l4hdr.gre);
h_outer.l4hdr.gre.protocol = bpf_htons(ETH_P_IP);
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.check = 0;
h_outer.l4hdr.udp.len = bpf_htons(bpf_ntohs(iph_inner.tot_len) +
sizeof(h_outer.l4hdr.udp));
break;
case IPPROTO_IPIP:
break;
default:
return TC_ACT_OK;
}
/* add room between mac and network header */
@ -85,16 +114,10 @@ static __always_inline int encap_ipv4(struct __sk_buff *skb, bool with_gre)
/* prepare new outer network header */
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;
}
bpf_ntohs(h_outer.ip.tot_len));
h_outer.ip.protocol = encap_proto;
set_ipv4_csum((void *)&h_outer.ip);
set_ipv4_csum(&h_outer.ip);
/* store new outer network header */
if (bpf_skb_store_bytes(skb, ETH_HLEN, &h_outer, olen,
@ -104,11 +127,12 @@ static __always_inline int encap_ipv4(struct __sk_buff *skb, bool with_gre)
return TC_ACT_OK;
}
static __always_inline int encap_ipv6(struct __sk_buff *skb, bool with_gre)
static __always_inline int encap_ipv6(struct __sk_buff *skb, __u8 encap_proto)
{
struct ipv6hdr iph_inner;
struct grev6hdr h_outer;
struct v6hdr h_outer;
struct tcphdr tcph;
__u16 tot_len;
__u64 flags;
int olen;
@ -124,14 +148,31 @@ 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 | BPF_F_ADJ_ROOM_ENCAP_L3_IPV6;
if (with_gre) {
flags |= BPF_F_ADJ_ROOM_ENCAP_L4_GRE;
olen = sizeof(h_outer);
} else {
olen = sizeof(h_outer.ip);
}
olen = sizeof(h_outer.ip);
flags = BPF_F_ADJ_ROOM_FIXED_GSO | BPF_F_ADJ_ROOM_ENCAP_L3_IPV6;
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.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);
tot_len = bpf_ntohs(iph_inner.payload_len) + sizeof(iph_inner) +
sizeof(h_outer.l4hdr.udp);
h_outer.l4hdr.udp.check = 0;
h_outer.l4hdr.udp.len = bpf_htons(tot_len);
break;
case IPPROTO_IPV6:
break;
default:
return TC_ACT_OK;
}
/* add room between mac and network header */
if (bpf_skb_adjust_room(skb, olen, BPF_ADJ_ROOM_MAC, flags))
@ -141,13 +182,8 @@ static __always_inline int encap_ipv6(struct __sk_buff *skb, bool with_gre)
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;
}
h_outer.ip.nexthdr = encap_proto;
/* store new outer network header */
if (bpf_skb_store_bytes(skb, ETH_HLEN, &h_outer, olen,
@ -161,7 +197,7 @@ SEC("encap_ipip")
int __encap_ipip(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IP))
return encap_ipv4(skb, false);
return encap_ipv4(skb, IPPROTO_IPIP);
else
return TC_ACT_OK;
}
@ -170,7 +206,16 @@ SEC("encap_gre")
int __encap_gre(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IP))
return encap_ipv4(skb, true);
return encap_ipv4(skb, IPPROTO_GRE);
else
return TC_ACT_OK;
}
SEC("encap_udp")
int __encap_udp(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IP))
return encap_ipv4(skb, IPPROTO_UDP);
else
return TC_ACT_OK;
}
@ -179,7 +224,7 @@ SEC("encap_ip6tnl")
int __encap_ip6tnl(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6))
return encap_ipv6(skb, false);
return encap_ipv6(skb, IPPROTO_IPV6);
else
return TC_ACT_OK;
}
@ -188,23 +233,34 @@ SEC("encap_ip6gre")
int __encap_ip6gre(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6))
return encap_ipv6(skb, true);
return encap_ipv6(skb, IPPROTO_GRE);
else
return TC_ACT_OK;
}
SEC("encap_ip6udp")
int __encap_ip6udp(struct __sk_buff *skb)
{
if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6))
return encap_ipv6(skb, IPPROTO_UDP);
else
return TC_ACT_OK;
}
static int decap_internal(struct __sk_buff *skb, int off, int len, char proto)
{
char buf[sizeof(struct grev6hdr)];
int olen;
char buf[sizeof(struct v6hdr)];
int olen = len;
switch (proto) {
case IPPROTO_IPIP:
case IPPROTO_IPV6:
olen = len;
break;
case IPPROTO_GRE:
olen = len + 4 /* gre hdr */;
olen += sizeof(struct gre_hdr);
break;
case IPPROTO_UDP:
olen += sizeof(struct udphdr);
break;
default:
return TC_ACT_OK;

View File

@ -15,6 +15,9 @@ readonly ns2_v4=192.168.1.2
readonly ns1_v6=fd::1
readonly ns2_v6=fd::2
# Must match port used by bpf program
readonly udpport=5555
readonly infile="$(mktemp)"
readonly outfile="$(mktemp)"
@ -38,8 +41,8 @@ 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 1476 dev veth1
ip -netns "${ns1}" -6 route add "${ns2_v6}" mtu 1456 dev veth1
ip -netns "${ns1}" -4 route add "${ns2_v4}" mtu 1472 dev veth1
ip -netns "${ns1}" -6 route add "${ns2_v6}" mtu 1452 dev veth1
sleep 1
@ -103,6 +106,18 @@ if [[ "$#" -eq "0" ]]; then
echo "ip6 gre gso"
$0 ipv6 ip6gre 2000
echo "ip udp"
$0 ipv4 udp 100
echo "ip6 udp"
$0 ipv6 ip6udp 100
echo "ip udp gso"
$0 ipv4 udp 2000
echo "ip6 udp gso"
$0 ipv6 ip6udp 2000
echo "OK. All tests passed"
exit 0
fi
@ -117,12 +132,20 @@ case "$1" in
"ipv4")
readonly addr1="${ns1_v4}"
readonly addr2="${ns2_v4}"
readonly netcat_opt=-4
readonly ipproto=4
readonly netcat_opt=-${ipproto}
readonly foumod=fou
readonly foutype=ipip
readonly fouproto=4
;;
"ipv6")
readonly addr1="${ns1_v6}"
readonly addr2="${ns2_v6}"
readonly netcat_opt=-6
readonly ipproto=6
readonly netcat_opt=-${ipproto}
readonly foumod=fou6
readonly foutype=ip6tnl
readonly fouproto="41 -6"
;;
*)
echo "unknown arg: $1"
@ -155,11 +178,23 @@ echo "test bpf encap without decap (expect failure)"
server_listen
! client_connect
if [[ "$tuntype" =~ "udp" ]]; then
# Set up fou tunnel.
ttype="${foutype}"
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 ${fouproto}
else
ttype=$tuntype
targs=""
fi
# serverside, insert decap module
# server is still running
# client can connect again
ip netns exec "${ns2}" ip link add dev testtun0 type "${tuntype}" \
remote "${addr1}" local "${addr2}"
ip netns exec "${ns2}" ip link add name testtun0 type "${ttype}" \
remote "${addr1}" local "${addr2}" $targs
# 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