selftests/bpf: Add netkit test for pkt_type

Add a test case to assert that the skb->pkt_type which was set from the BPF
program is retained from the netkit xmit side to the peer's device at tcx
ingress location.

  # ./vmtest.sh -- ./test_progs -t netkit
  [...]
  ./test_progs -t netkit
  [    1.140780] bpf_testmod: loading out-of-tree module taints kernel.
  [    1.141127] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
  [    1.284601] tsc: Refined TSC clocksource calibration: 3408.006 MHz
  [    1.286672] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x311fd9b189d, max_idle_ns: 440795225691 ns
  [    1.290384] clocksource: Switched to clocksource tsc
  #345     tc_netkit_basic:OK
  #346     tc_netkit_device:OK
  #347     tc_netkit_multi_links:OK
  #348     tc_netkit_multi_opts:OK
  #349     tc_netkit_neigh_links:OK
  #350     tc_netkit_pkt_type:OK
  Summary: 6/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20240524163619.26001-4-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Daniel Borkmann 2024-05-24 18:36:19 +02:00 committed by Alexei Starovoitov
parent 998ffeb273
commit 95348e463e
2 changed files with 118 additions and 1 deletions

View File

@ -99,6 +99,16 @@ static int create_netkit(int mode, int policy, int peer_policy, int *ifindex,
return err;
}
static void move_netkit(void)
{
ASSERT_OK(system("ip link set " netkit_peer " netns foo"),
"move peer");
ASSERT_OK(system("ip netns exec foo ip link set dev "
netkit_peer " up"), "up peer");
ASSERT_OK(system("ip netns exec foo ip addr add dev "
netkit_peer " 10.0.0.2/24"), "addr peer");
}
static void destroy_netkit(void)
{
ASSERT_OK(system("ip link del dev " netkit_name), "del primary");
@ -695,3 +705,77 @@ void serial_test_tc_netkit_neigh_links(void)
serial_test_tc_netkit_neigh_links_target(NETKIT_L2, BPF_NETKIT_PRIMARY);
serial_test_tc_netkit_neigh_links_target(NETKIT_L3, BPF_NETKIT_PRIMARY);
}
static void serial_test_tc_netkit_pkt_type_mode(int mode)
{
LIBBPF_OPTS(bpf_netkit_opts, optl_nk);
LIBBPF_OPTS(bpf_tcx_opts, optl_tcx);
int err, ifindex, ifindex2;
struct test_tc_link *skel;
struct bpf_link *link;
err = create_netkit(mode, NETKIT_PASS, NETKIT_PASS,
&ifindex, true);
if (err)
return;
ifindex2 = if_nametoindex(netkit_peer);
ASSERT_NEQ(ifindex, ifindex2, "ifindex_1_2");
skel = test_tc_link__open();
if (!ASSERT_OK_PTR(skel, "skel_open"))
goto cleanup;
ASSERT_EQ(bpf_program__set_expected_attach_type(skel->progs.tc1,
BPF_NETKIT_PRIMARY), 0, "tc1_attach_type");
ASSERT_EQ(bpf_program__set_expected_attach_type(skel->progs.tc7,
BPF_TCX_INGRESS), 0, "tc7_attach_type");
err = test_tc_link__load(skel);
if (!ASSERT_OK(err, "skel_load"))
goto cleanup;
assert_mprog_count_ifindex(ifindex, BPF_NETKIT_PRIMARY, 0);
assert_mprog_count_ifindex(ifindex2, BPF_TCX_INGRESS, 0);
link = bpf_program__attach_netkit(skel->progs.tc1, ifindex, &optl_nk);
if (!ASSERT_OK_PTR(link, "link_attach"))
goto cleanup;
skel->links.tc1 = link;
assert_mprog_count_ifindex(ifindex, BPF_NETKIT_PRIMARY, 1);
assert_mprog_count_ifindex(ifindex2, BPF_TCX_INGRESS, 0);
link = bpf_program__attach_tcx(skel->progs.tc7, ifindex2, &optl_tcx);
if (!ASSERT_OK_PTR(link, "link_attach"))
goto cleanup;
skel->links.tc7 = link;
assert_mprog_count_ifindex(ifindex, BPF_NETKIT_PRIMARY, 1);
assert_mprog_count_ifindex(ifindex2, BPF_TCX_INGRESS, 1);
move_netkit();
tc_skel_reset_all_seen(skel);
skel->bss->set_type = true;
ASSERT_EQ(send_icmp(), 0, "icmp_pkt");
ASSERT_EQ(skel->bss->seen_tc1, true, "seen_tc1");
ASSERT_EQ(skel->bss->seen_tc7, true, "seen_tc7");
ASSERT_EQ(skel->bss->seen_host, true, "seen_host");
ASSERT_EQ(skel->bss->seen_mcast, true, "seen_mcast");
cleanup:
test_tc_link__destroy(skel);
assert_mprog_count_ifindex(ifindex, BPF_NETKIT_PRIMARY, 0);
destroy_netkit();
}
void serial_test_tc_netkit_pkt_type(void)
{
serial_test_tc_netkit_pkt_type_mode(NETKIT_L2);
serial_test_tc_netkit_pkt_type_mode(NETKIT_L3);
}

View File

@ -4,7 +4,8 @@
#include <linux/bpf.h>
#include <linux/if_ether.h>
#include <linux/stddef.h>
#include <linux/if_packet.h>
#include <bpf/bpf_endian.h>
#include <bpf/bpf_helpers.h>
@ -16,7 +17,13 @@ bool seen_tc3;
bool seen_tc4;
bool seen_tc5;
bool seen_tc6;
bool seen_tc7;
bool set_type;
bool seen_eth;
bool seen_host;
bool seen_mcast;
SEC("tc/ingress")
int tc1(struct __sk_buff *skb)
@ -28,8 +35,16 @@ int tc1(struct __sk_buff *skb)
if (bpf_skb_load_bytes(skb, 0, &eth, sizeof(eth)))
goto out;
seen_eth = eth.h_proto == bpf_htons(ETH_P_IP);
seen_host = skb->pkt_type == PACKET_HOST;
if (seen_host && set_type) {
eth.h_dest[0] = 4;
if (bpf_skb_store_bytes(skb, 0, &eth, sizeof(eth), 0))
goto fail;
bpf_skb_change_type(skb, PACKET_MULTICAST);
}
out:
seen_tc1 = true;
fail:
return TCX_NEXT;
}
@ -67,3 +82,21 @@ int tc6(struct __sk_buff *skb)
seen_tc6 = true;
return TCX_PASS;
}
SEC("tc/ingress")
int tc7(struct __sk_buff *skb)
{
struct ethhdr eth = {};
if (skb->protocol != __bpf_constant_htons(ETH_P_IP))
goto out;
if (bpf_skb_load_bytes(skb, 0, &eth, sizeof(eth)))
goto out;
if (eth.h_dest[0] == 4 && set_type) {
seen_mcast = skb->pkt_type == PACKET_MULTICAST;
bpf_skb_change_type(skb, PACKET_HOST);
}
out:
seen_tc7 = true;
return TCX_PASS;
}