On Thu, Aug 5, 2021 at 9:10 AM Jussi Maki [off-list ref] wrote:

Add a test suite to test XDP bonding implementation
over a pair of veth devices.

Signed-off-by: Jussi Maki <redacted>
---
 .../selftests/bpf/prog_tests/xdp_bonding.c    | 520 ++++++++++++++++++
 1 file changed, 520 insertions(+)

I don't pretend to understand what's going on in this selftests, but
it looks good from the generic selftest standpoint. One and half small
issues below, please double-check (and probably fix the fd close
issue).

Acked-by: Andrii Nakryiko <andrii@kernel.org>


[...]

+
+/* Test the broadcast redirection using xdp_redirect_map_multi_prog and adding
+ * all the interfaces to it and checking that broadcasting won't send the packet
+ * to neither the ingress bond device (bond2) or its slave (veth2_1).
+ */
+static void test_xdp_bonding_redirect_multi(struct skeletons *skeletons)
+{
+       static const char * const ifaces[] = {"bond2", "veth2_1", "veth2_2"};
+       int veth1_1_rx, veth1_2_rx;
+       int err;
+
+       if (bonding_setup(skeletons, BOND_MODE_ROUNDROBIN, BOND_XMIT_POLICY_LAYER23,
+                         BOND_ONE_NO_ATTACH))
+               goto out;
+
+
+       if (!ASSERT_OK(setns_by_name("ns_dst"), "could not set netns to ns_dst"))
+               goto out;
+
+       /* populate the devmap with the relevant interfaces */
+       for (int i = 0; i < ARRAY_SIZE(ifaces); i++) {
+               int ifindex = if_nametoindex(ifaces[i]);
+               int map_fd = bpf_map__fd(skeletons->xdp_redirect_multi_kern->maps.map_all);
+
+               if (!ASSERT_GT(ifindex, 0, "could not get interface index"))
+                       goto out;
+
+               err = bpf_map_update_elem(map_fd, &ifindex, &ifindex, 0);
+               if (!ASSERT_OK(err, "add interface to map_all"))
+                       goto out;
+       }
+
+       if (xdp_attach(skeletons,
+                      skeletons->xdp_redirect_multi_kern->progs.xdp_redirect_map_multi_prog,
+                      "bond2"))
+               goto out;
+
+       restore_root_netns();

the "goto out" below might call restore_root_netns() again, is that ok?

+
+       if (send_udp_packets(BOND_MODE_ROUNDROBIN))
+               goto out;
+
+       veth1_1_rx = get_rx_packets("veth1_1");
+       veth1_2_rx = get_rx_packets("veth1_2");
+
+       ASSERT_EQ(veth1_1_rx, 0, "expected no packets on veth1_1");
+       ASSERT_GE(veth1_2_rx, NPACKETS, "expected packets on veth1_2");
+
+out:
+       restore_root_netns();
+       bonding_cleanup(skeletons);
+}
+

[...]

+
+void test_xdp_bonding(void)
+{
+       libbpf_print_fn_t old_print_fn;
+       struct skeletons skeletons = {};
+       int i;
+
+       old_print_fn = libbpf_set_print(libbpf_debug_print);
+
+       root_netns_fd = open("/proc/self/ns/net", O_RDONLY);
+       if (!ASSERT_GE(root_netns_fd, 0, "open /proc/self/ns/net"))
+               goto out;
+
+       skeletons.xdp_dummy = xdp_dummy__open_and_load();
+       if (!ASSERT_OK_PTR(skeletons.xdp_dummy, "xdp_dummy__open_and_load"))
+               goto out;
+
+       skeletons.xdp_tx = xdp_tx__open_and_load();
+       if (!ASSERT_OK_PTR(skeletons.xdp_tx, "xdp_tx__open_and_load"))
+               goto out;
+
+       skeletons.xdp_redirect_multi_kern = xdp_redirect_multi_kern__open_and_load();
+       if (!ASSERT_OK_PTR(skeletons.xdp_redirect_multi_kern,
+                          "xdp_redirect_multi_kern__open_and_load"))
+               goto out;
+
+       if (!test__start_subtest("xdp_bonding_attach"))
+               test_xdp_bonding_attach(&skeletons);
+
+       for (i = 0; i < ARRAY_SIZE(bond_test_cases); i++) {
+               struct bond_test_case *test_case = &bond_test_cases[i];
+
+               if (!test__start_subtest(test_case->name))
+                       test_xdp_bonding_with_mode(
+                               &skeletons,
+                               test_case->mode,
+                               test_case->xmit_policy);
+       }
+
+       if (!test__start_subtest("xdp_bonding_redirect_multi"))
+               test_xdp_bonding_redirect_multi(&skeletons);
+
+out:
+       xdp_dummy__destroy(skeletons.xdp_dummy);
+       xdp_tx__destroy(skeletons.xdp_tx);
+       xdp_redirect_multi_kern__destroy(skeletons.xdp_redirect_multi_kern);
+
+       libbpf_set_print(old_print_fn);
+       if (root_netns_fd)

technically, fd could be 0, so for fds we have if (fd >= 0)
everywhere. Also, if open() above fails, root_netns_fd will be -1 and
you'll still attempt to close it.

+               close(root_netns_fd);
+}
--
2.17.1