Re: [PATCH v2 bpf-next 4/6] selftests/bpf: Add IPv4 and IPv6 sockaddr test cases

[Martin KaFai Lau]

On 4/12/24 9:52 AM, Jordan Rife wrote:
This patch lays the groundwork for testing IPv4 and IPv6 sockaddr hooks
and their interaction with both socket syscalls and kernel functions
(e.g. kernel_connect, kernel_bind, etc.) and moves the test cases from
the old-style bpf/test_sock_addr.c self test into the sock_addr
prog_test.

Thanks for moving the existing sock_addr test to the test_progs.

+static int ping_once(int ipv, const char *addr)
+{
+       const char *ping_cmd_prefix = "ping -";
+
+       if (!SYS_NOFAIL("type ping%d >/dev/null 2>&1", ipv))
+               ping_cmd_prefix = "ping";
+
+       return SYS_NOFAIL("%s%d -q -c 1 -W 1 %s >/dev/null 2>&1",
+                         ping_cmd_prefix, ipv, addr);
+}
+
+static int setup_test_env(void)
+{
+       SYS(err, "ip link add dev %s1 type veth peer name %s2", TEST_IF_PREFIX,
+           TEST_IF_PREFIX);

I would like to take this chance to simplify the setup.

Does it need a veth pair? The %s2 interface is not used.

Can it be done in lo alone?

Also, all this setup (and test) has to be done in a new netns. Anything blocking 
the kfunc in patch 2 using the current task netns instead of the init_net?


+       SYS(err, "ip link set %s1 up", TEST_IF_PREFIX);
+       SYS(err, "ip link set %s2 up", TEST_IF_PREFIX);
+       SYS(err, "ip -4 addr add %s/8 dev %s1", TEST_IPV4, TEST_IF_PREFIX);
+       SYS(err, "ip -6 addr add %s/128 dev %s1", TEST_IPV6, TEST_IF_PREFIX);

Add nodad to the "ip -6 addr add...". just in case it may add unnecessary delay.

+
+       int i;
+
+       for (i = 0; i < 5; i++) {
+               if (!ping_once(4, TEST_IPV4) && !ping_once(6, TEST_IPV6))

This interface/address ping should not be needed. Other tests under prog_tests/ 
don't need this interface/address ping also.

+                       return 0;
+       }
+
+       ASSERT_FAIL("Timed out waiting for test IP to become available.");
+err:
+       return -1;
+}
+
+static void cleanup_test_env(void)
+{
+       SYS_NOFAIL("ip link del %s1 2>/dev/null", TEST_IF_PREFIX);
+       SYS_NOFAIL("ip link del %s2 2>/dev/null", TEST_IF_PREFIX);

Using lo will make this easier. Regardless, the link should go away with the 
netns.

+}
+
  void test_sock_addr(void)
  {
        int cgroup_fd = -1;
        void *skel;
  
+	if (!ASSERT_OK(setup_test_env(), "setup_test_env"))

This will probably have to be called after the test__join_cgroup() if it also 
creates a new netns.

pw-bot: cr

+               goto cleanup;
+
        cgroup_fd = test__join_cgroup("/sock_addr");
        if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup"))
                goto cleanup;
@@ -609,4 +755,5 @@ void test_sock_addr(void)
  cleanup:
        if (cgroup_fd >= 0)
                close(cgroup_fd);
+       cleanup_test_env();
  }