[PATCH bpf-next] selftests/bpf: Omit nodad flag when adding addresses to loopback

Setting IFA_F_NODAD flag for IPv6 addresses to add to loopback is
unnecessary. Duplicate Address Detection does not happen on loopback
device.

Also, passing 'nodad' flag to 'ip address' breaks libbpf CI, which runs in
an environment with BusyBox implementation of 'ip' command, that doesn't
understand this flag.

Fixes: 0ab5539f8584 ("selftests/bpf: Tests for BPF_SK_LOOKUP attach point")
Reported-by: Andrii Nakryiko <redacted>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
---
 tools/testing/selftests/bpf/prog_tests/sk_lookup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c
index 9bbd2b2b7630..379da6f10ee9 100644
--- a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c
+++ b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c

@@ -1290,8 +1290,8 @@ static void run_tests(struct test_sk_lookup *skel)
 static int switch_netns(void)
 {
 	static const char * const setup_script[] = {
-		"ip -6 addr add dev lo " EXT_IP6 "/128 nodad",
-		"ip -6 addr add dev lo " INT_IP6 "/128 nodad",
+		"ip -6 addr add dev lo " EXT_IP6 "/128",
+		"ip -6 addr add dev lo " INT_IP6 "/128",
 		"ip link set dev lo up",
 		NULL,
 	};

-- 
2.25.4

On Thu, Jul 30, 2020 at 5:53 AM Jakub Sitnicki [off-list ref] wrote:

Setting IFA_F_NODAD flag for IPv6 addresses to add to loopback is
unnecessary. Duplicate Address Detection does not happen on loopback
device.

Also, passing 'nodad' flag to 'ip address' breaks libbpf CI, which runs in
an environment with BusyBox implementation of 'ip' command, that doesn't
understand this flag.

Fixes: 0ab5539f8584 ("selftests/bpf: Tests for BPF_SK_LOOKUP attach point")
Reported-by: Andrii Nakryiko <redacted>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
---

This fixes the nodad issue, thanks for quick fix!

Tested-by: Andrii Nakryiko <redacted>
Acked-by: Andrii Nakryiko <redacted>


But now I see these, which seems like you have a separate fix for, right?

(network_helpers.c:112: errno: Cannot assign requested address) Failed
to connect to server
run_lookup_test:FAIL:connect_fd_to_fd unexpected result err -1 errno 99
#14 cgroup_skb_sk_lookup:FAIL

udp_recv_send:FAIL:recvmsg failed
(/data/users/andriin/linux/tools/testing/selftests/bpf/prog_tests/sk_lookup.c:339:
errno: Resource temporarily unavailable) failed to receive
#73/14 UDP IPv4 redir and reuseport with conns:FAIL

On 7/30/20 2:53 PM, Jakub Sitnicki wrote:

Setting IFA_F_NODAD flag for IPv6 addresses to add to loopback is
unnecessary. Duplicate Address Detection does not happen on loopback
device.

Also, passing 'nodad' flag to 'ip address' breaks libbpf CI, which runs in
an environment with BusyBox implementation of 'ip' command, that doesn't
understand this flag.

Fixes: 0ab5539f8584 ("selftests/bpf: Tests for BPF_SK_LOOKUP attach point")
Reported-by: Andrii Nakryiko <redacted>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>

Applied, thanks!