Adds test to check that bpf_skb_change_head can be used
in combination with bpf_redirect_peer to redirect a packet
from L3 device to veth.
Fixes: a426d97e970d ("bpf: Set mac_len in bpf_skb_change_head")
Signed-off-by: Jussi Maki <joamaki@xxxxxxxxx>
---
tools/testing/selftests/bpf/.gitignore | 1 +
tools/testing/selftests/bpf/Makefile | 2 +-
.../selftests/bpf/progs/test_tc_peer.c | 24 ++++
.../testing/selftests/bpf/test_tc_peer_user.c | 127 ++++++++++++++++++
.../testing/selftests/bpf/test_tc_redirect.sh | 95 ++++++++++---
5 files changed, 233 insertions(+), 16 deletions(-)
create mode 100644 tools/testing/selftests/bpf/test_tc_peer_user.c
diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
index 4866f6a21901..49f3f050be4d 100644
--- a/tools/testing/selftests/bpf/.gitignore
+++ b/tools/testing/selftests/bpf/.gitignore
@@ -27,6 +27,7 @@ test_tcpnotify_user
test_libbpf
test_tcp_check_syncookie_user
test_sysctl
+test_tc_peer_user
xdping
test_cpp
*.skel.h
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 283e5ad8385e..0e05fefe2333 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -84,7 +84,7 @@ TEST_PROGS_EXTENDED := with_addr.sh \
TEST_GEN_PROGS_EXTENDED = test_sock_addr test_skb_cgroup_id_user \
flow_dissector_load test_flow_dissector test_tcp_check_syncookie_user \
test_lirc_mode2_user xdping test_cpp runqslower bench bpf_testmod.ko \
- xdpxceiver
+ xdpxceiver test_tc_peer_user
TEST_CUSTOM_PROGS = $(OUTPUT)/urandom_read
diff --git a/tools/testing/selftests/bpf/progs/test_tc_peer.c b/tools/testing/selftests/bpf/progs/test_tc_peer.c
index fc84a7685aa2..49f0eefd58e7 100644
--- a/tools/testing/selftests/bpf/progs/test_tc_peer.c
+++ b/tools/testing/selftests/bpf/progs/test_tc_peer.c
@@ -5,8 +5,11 @@
#include <linux/bpf.h>
#include <linux/stddef.h>
#include <linux/pkt_cls.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
enum {
dev_src,
@@ -42,4 +45,25 @@ SEC("src_ingress") int tc_src(struct __sk_buff *skb)
return bpf_redirect_peer(get_dev_ifindex(dev_dst), 0);
}
+SEC("src_ingress_l3") int tc_src_l3(struct __sk_buff *skb)
+{
+ __u16 proto = skb->protocol;
+
+ if (bpf_skb_change_head(skb, ETH_HLEN, 0) != 0)
+ return TC_ACT_SHOT;
+
+ __u8 src_mac[] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55};
+ if (bpf_skb_store_bytes(skb, 0, &src_mac, ETH_ALEN, 0) != 0)
+ return TC_ACT_SHOT;
+
+ __u8 dst_mac[] = {0x00, 0x22, 0x33, 0x44, 0x55, 0x66};
+ if (bpf_skb_store_bytes(skb, ETH_ALEN, &dst_mac, ETH_ALEN, 0) != 0)
+ return TC_ACT_SHOT;
+
+ if (bpf_skb_store_bytes(skb, ETH_ALEN + ETH_ALEN, &proto, sizeof(__u16), 0) != 0)
+ return TC_ACT_SHOT;
+
+ return bpf_redirect_peer(get_dev_ifindex(dev_dst), 0);
+}
+
char __license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/test_tc_peer_user.c b/tools/testing/selftests/bpf/test_tc_peer_user.c
new file mode 100644
index 000000000000..bdecf2bd1cc1
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_tc_peer_user.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Networking across two network namespaces based on TUN/TAP.
+ * Like veth, but slow and L3. Used for testing BPF redirect_peer
+ * from L3 to L2 veth device.
+ */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/if.h>
+#include <linux/if_tun.h>
+#include <linux/limits.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+int tun_alloc(char *name) {
+ struct ifreq ifr;
+ int fd, err;
+ char cmd[512];
+
+ if ((fd = open("/dev/net/tun", O_RDWR)) < 0)
+ return -1;
+
+ memset(&ifr, 0, sizeof(ifr));
+
+ ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
+ if (*name)
+ strncpy(ifr.ifr_name, name, IFNAMSIZ);
+
+ if ((err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0) {
+ close(fd);
+ return err;
+ }
+
+ snprintf(cmd, sizeof(cmd), "ip link set dev %s up", name);
+ system(cmd);
+
+ return fd;
+}
+
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+
+enum {
+ SRC_TO_TARGET = 0,
+ TARGET_TO_SRC = 1,
+};
+
+void setns_by_name(char *name) {
+ int nsfd;
+ char nspath[PATH_MAX];
+
+ snprintf(nspath, sizeof(nspath), "%s/%s", "/var/run/netns", name);
+ nsfd = open(nspath, O_RDONLY | O_CLOEXEC);
+ if (nsfd < 0) {
+ fprintf(stderr, "failed to open net namespace %s: %s\n", name, strerror(errno));
+ exit(1);
+ }
+ setns(nsfd, CLONE_NEWNET);
+ close(nsfd);
+}
+
+int main(int argc, char **argv) {
+ char *src_ns, *src_tun, *target_ns, *target_tun;
+ int srcfd, targetfd;
+
+ if (argc != 5) {
+ fprintf(stderr, "usage: %s <source namespace> <source tun device name> <target namespace> <target tun device name>\n", argv[0]);
+ return 1;
+ }
+
+ src_ns = argv[1];
+ src_tun = argv[2];
+ target_ns = argv[3];
+ target_tun = argv[4];
+
+ setns_by_name(src_ns);
+ srcfd = tun_alloc(src_tun);
+ if (srcfd < 0) {
+ fprintf(stderr, "failed to allocate tun device\n");
+ return 1;
+ }
+
+ setns_by_name(target_ns);
+ targetfd = tun_alloc(target_tun);
+ if (srcfd < 0) {
+ fprintf(stderr, "failed to allocate tun device\n");
+ return 1;
+ }
+
+ fd_set rfds, wfds;
+ FD_ZERO(&rfds);
+ FD_ZERO(&wfds);
+
+ for (;;) {
+ char buf[4096];
+ int direction, nread, nwrite;
+ FD_SET(srcfd, &rfds);
+ FD_SET(targetfd, &rfds);
+
+ if (select(1 + MAX(srcfd, targetfd), &rfds, NULL, NULL, NULL) < 0) {
+ fprintf(stderr, "select failed: %s\n", strerror(errno));
+ return 1;
+ }
+
+ direction = FD_ISSET(srcfd, &rfds) ? SRC_TO_TARGET : TARGET_TO_SRC;
+
+ nread = read(direction == SRC_TO_TARGET ? srcfd : targetfd, buf, sizeof(buf));
+ if (nread < 0) {
+ fprintf(stderr, "read failed: %s\n", strerror(errno));
+ return 1;
+ }
+
+ nwrite = write(direction == SRC_TO_TARGET ? targetfd : srcfd, buf, nread);
+ if (nwrite != nread) {
+ fprintf(stderr, "write failed: %s\n", strerror(errno));
+ return 1;
+ }
+ }
+}
diff --git a/tools/testing/selftests/bpf/test_tc_redirect.sh b/tools/testing/selftests/bpf/test_tc_redirect.sh
index 8868aa1ca902..469e1dc13f03 100755
--- a/tools/testing/selftests/bpf/test_tc_redirect.sh
+++ b/tools/testing/selftests/bpf/test_tc_redirect.sh
@@ -50,15 +50,32 @@ readonly IP4_DST="172.16.2.100"
readonly IP6_SRC="::1:dead:beef:cafe"
readonly IP6_DST="::2:dead:beef:cafe"
+readonly IP4_TUN_SRC="172.17.1.100"
+readonly IP4_TUN_FWD="172.17.1.200"
+
+readonly IP6_TUN_SRC="1::dead:beef:0"
+readonly IP6_TUN_FWD="1::dead:beef:1"
+
readonly IP4_SLL="169.254.0.1"
readonly IP4_DLL="169.254.0.2"
readonly IP4_NET="169.254.0.0"
+readonly MAC_DST_FWD="00:11:22:33:44:55"
+readonly MAC_DST="00:22:33:44:55:66"
+
+TEST_TC_PEER_USER_PID=""
+NC4_PID=""
+NC6_PID=""
+
netns_cleanup()
{
ip netns del ${NS_SRC}
ip netns del ${NS_FWD}
ip netns del ${NS_DST}
+
+ [ -n "$TEST_TC_PEER_USER_PID" ] && kill ${TEST_TC_PEER_USER_PID} || true
+ [ -n "${NC4_PID}" ] && kill ${NC4_PID} || true
+ [ -n "${NC6_PID}" ] && kill ${NC6_PID} || true
}
netns_setup()
@@ -70,6 +87,9 @@ netns_setup()
ip link add veth_src type veth peer name veth_src_fwd
ip link add veth_dst type veth peer name veth_dst_fwd
+ ip link set veth_dst_fwd address ${MAC_DST_FWD}
+ ip link set veth_dst address ${MAC_DST}
+
ip link set veth_src netns ${NS_SRC}
ip link set veth_src_fwd netns ${NS_FWD}
@@ -117,14 +137,20 @@ netns_setup()
ip -netns ${NS_SRC} neigh add ${IP6_DST} dev veth_src lladdr $fmac_src
ip -netns ${NS_DST} neigh add ${IP6_SRC} dev veth_dst lladdr $fmac_dst
+
+ ip -netns ${NS_DST} neigh add ${IP4_TUN_SRC} dev veth_dst lladdr $fmac_dst
+ ip -netns ${NS_DST} neigh add ${IP6_TUN_SRC} dev veth_dst lladdr $fmac_dst
+ ip -netns ${NS_DST} neigh add ${IP6_TUN_FWD} dev veth_dst lladdr $fmac_dst
}
netns_test_connectivity()
{
set +e
- ip netns exec ${NS_DST} bash -c "nc -4 -l -p 9004 &"
- ip netns exec ${NS_DST} bash -c "nc -6 -l -p 9006 &"
+ ip netns exec ${NS_DST} nc -4 -l -p 9004 &
+ NC4_PID=$!
+ ip netns exec ${NS_DST} nc -6 -l -p 9006 &
+ NC6_PID=$!
TEST="TCPv4 connectivity test"
ip netns exec ${NS_SRC} bash -c "timeout ${TIMEOUT} dd if=/dev/zero bs=1000 count=100 > /dev/tcp/${IP4_DST}/9004"
@@ -170,14 +196,52 @@ netns_setup_bpf()
{
local obj=$1
local use_forwarding=${2:-0}
+ local use_tuntap=${3:-0}
+
+ if [ "$use_tuntap" -eq "1" ]; then
+ # Set up tuntap based tunnel between src and fwd namespaces.
+ ./test_tc_peer_user ${NS_SRC} tun_src ${NS_FWD} tun_fwd &
+ TEST_TC_PEER_USER_PID=$!
+
+ while ! ip -netns ${NS_SRC} link show tun_src; do echo "Waiting for tun_src to appear..."; sleep 0.5; done
+ while ! ip -netns ${NS_FWD} link show tun_fwd; do echo "Waiting for tun_fwd to appoar..."; sleep 0.5; done
+
+ ip -netns ${NS_SRC} addr add dev tun_src ${IP4_TUN_SRC}/24
+ ip -netns ${NS_FWD} addr add dev tun_fwd ${IP4_TUN_FWD}/24
- ip netns exec ${NS_FWD} tc qdisc add dev veth_src_fwd clsact
- ip netns exec ${NS_FWD} tc filter add dev veth_src_fwd ingress bpf da obj $obj sec src_ingress
- ip netns exec ${NS_FWD} tc filter add dev veth_src_fwd egress bpf da obj $obj sec chk_egress
+ ip -netns ${NS_SRC} addr add dev tun_src ${IP6_TUN_SRC}/64 nodad
+ ip -netns ${NS_FWD} addr add dev tun_fwd ${IP6_TUN_FWD}/64 nodad
- ip netns exec ${NS_FWD} tc qdisc add dev veth_dst_fwd clsact
- ip netns exec ${NS_FWD} tc filter add dev veth_dst_fwd ingress bpf da obj $obj sec dst_ingress
- ip netns exec ${NS_FWD} tc filter add dev veth_dst_fwd egress bpf da obj $obj sec chk_egress
+ ip -netns ${NS_SRC} route del ${IP4_DST}/32 dev veth_src scope global
+ ip -netns ${NS_SRC} route add ${IP4_DST}/32 via ${IP4_TUN_FWD} dev tun_src scope global
+ ip -netns ${NS_DST} route add ${IP4_TUN_SRC}/32 dev veth_dst scope global
+
+ ip -netns ${NS_SRC} route del ${IP6_DST}/128 dev veth_src scope global
+ ip -netns ${NS_SRC} route add ${IP6_DST}/128 via ${IP6_TUN_FWD} dev tun_src scope global
+ ip -netns ${NS_DST} route add ${IP6_TUN_SRC}/128 dev veth_dst scope global
+ ip -netns ${NS_DST} route add ${IP6_TUN_FWD}/128 dev veth_dst scope global
+
+ ip netns exec ${NS_FWD} tc qdisc add dev tun_fwd clsact
+ ip netns exec ${NS_FWD} tc filter add dev tun_fwd ingress bpf da obj $obj sec src_ingress_l3
+
+ # Enable forwarding back towards src, but not for packets coming from the tunnel.
+ ip netns exec ${NS_FWD} sysctl -w net.ipv4.ip_forward=1
+ ip netns exec ${NS_FWD} sysctl -w net.ipv6.conf.all.forwarding=1
+ ip netns exec ${NS_FWD} sysctl -w net.ipv4.conf.veth_dst_fwd.forwarding=1
+ ip netns exec ${NS_FWD} sysctl -w net.ipv4.conf.veth_src_fwd.forwarding=0
+ ip netns exec ${NS_FWD} sysctl -w net.ipv4.conf.tun_fwd.forwarding=0
+ ip netns exec ${NS_FWD} sysctl -w net.ipv6.conf.veth_src_fwd.forwarding=0
+ ip netns exec ${NS_FWD} sysctl -w net.ipv6.conf.veth_dst_fwd.forwarding=1
+ ip netns exec ${NS_FWD} sysctl -w net.ipv6.conf.tun_fwd.forwarding=0
+ else
+ ip netns exec ${NS_FWD} tc qdisc add dev veth_src_fwd clsact
+ ip netns exec ${NS_FWD} tc filter add dev veth_src_fwd ingress bpf da obj $obj sec src_ingress
+ ip netns exec ${NS_FWD} tc filter add dev veth_src_fwd egress bpf da obj $obj sec chk_egress
+
+ ip netns exec ${NS_FWD} tc qdisc add dev veth_dst_fwd clsact
+ ip netns exec ${NS_FWD} tc filter add dev veth_dst_fwd ingress bpf da obj $obj sec dst_ingress
+ ip netns exec ${NS_FWD} tc filter add dev veth_dst_fwd egress bpf da obj $obj sec chk_egress
+ fi
if [ "$use_forwarding" -eq "1" ]; then
# bpf_fib_lookup() checks if forwarding is enabled
@@ -190,13 +254,10 @@ netns_setup_bpf()
veth_src=$(ip netns exec ${NS_FWD} cat /sys/class/net/veth_src_fwd/ifindex)
veth_dst=$(ip netns exec ${NS_FWD} cat /sys/class/net/veth_dst_fwd/ifindex)
- progs=$(ip netns exec ${NS_FWD} bpftool net --json | jq -r '.[] | .tc | map(.id) | .[]')
- for prog in $progs; do
- map=$(bpftool prog show id $prog --json | jq -r '.map_ids | .? | .[]')
- if [ ! -z "$map" ]; then
- bpftool map update id $map key hex $(hex_mem_str 0) value hex $(hex_mem_str $veth_src)
- bpftool map update id $map key hex $(hex_mem_str 1) value hex $(hex_mem_str $veth_dst)
- fi
+ maps=$(bpftool map list --json | jq -r '.[] | select(.name == "ifindex_map") | .id')
+ for map in $maps; do
+ bpftool map update id $map key hex $(hex_mem_str 0) value hex $(hex_mem_str $veth_src)
+ bpftool map update id $map key hex $(hex_mem_str 1) value hex $(hex_mem_str $veth_dst)
done
}
@@ -214,3 +275,7 @@ netns_cleanup
netns_setup
netns_setup_bpf test_tc_peer.o
netns_test_connectivity
+netns_cleanup
+netns_setup
+netns_setup_bpf test_tc_peer.o 0 1
+netns_test_connectivity
--
2.30.2
