[bpf-next,v9,2/4] selftests/bpf: Use random netns name for mptcp

Commit Message

Geliang Tang Aug. 3, 2023, 1:41 p.m. UTC

Use rand() to generate a random netns name instead of using the fixed
name "mptcp_ns" for every test.

By doing that, we can re-launch the test even if there was an issue
removing the previous netns or if by accident, a netns with this generic
name already existed on the system.

Note that using a different name each will also help adding more
subtests in future commits.

Signed-off-by: Geliang Tang <[e-mail]>
Reviewed-by: Matthieu Baerts <[e-mail]>
---
 tools/testing/selftests/bpf/prog_tests/mptcp.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Yonghong Song Aug. 3, 2023, 11:20 p.m. UTC | #1

On 8/3/23 6:41 AM, Geliang Tang wrote:
> Use rand() to generate a random netns name instead of using the fixed
> name "mptcp_ns" for every test.
> 
> By doing that, we can re-launch the test even if there was an issue
> removing the previous netns or if by accident, a netns with this generic
> name already existed on the system.
> 
> Note that using a different name each will also help adding more
> subtests in future commits.
> 
> Signed-off-by: Geliang Tang <[e-mail]>
> Reviewed-by: Matthieu Baerts <[e-mail]>

Acked-by: Yonghong Song <[e-mail]>

Patch

diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
index cd0c42fff7c0..4ccca3d39a8f 100644
--- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -7,7 +7,7 @@ 
 #include "network_helpers.h"
 #include "mptcp_sock.skel.h"
 
-#define NS_TEST "mptcp_ns"
+char NS_TEST[32];
 
 #ifndef TCP_CA_NAME_MAX
 #define TCP_CA_NAME_MAX	16
@@ -147,6 +147,8 @@  static void test_base(void)
 	if (!ASSERT_GE(cgroup_fd, 0, "test__join_cgroup"))
 		return;
 
+	srand(time(NULL));
+	snprintf(NS_TEST, sizeof(NS_TEST), "mptcp_ns_%d", rand());
 	SYS(fail, "ip netns add %s", NS_TEST);
 	SYS(fail, "ip -net %s link set dev lo up", NS_TEST);