selftests/bpf: Update bpf_clone_redirect expected return code

Commit 151e887d8ff9 ("veth: Fixing transmit return status for dropped
packets") started propagating proper NET_XMIT_DROP error to the caller
which means it's now possible to get positive error code when calling
bpf_clone_redirect() in this particular test. Update the test to reflect
that.

Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230911194731.286342-2-sdf@google.com

diff --git a/tools/testing/selftests/bpf/prog_tests/empty_skb.c b/tools/testing/selftests/bpf/prog_tests/empty_skb.c
index 3b77d8a..261228e 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/empty_skb.c
+++ b/tools/testing/selftests/bpf/prog_tests/empty_skb.c
@@ -24,6 +24,7 @@ void test_empty_skb(void)
                int *ifindex;
                int err;
                int ret;
+               int lwt_egress_ret; /* expected retval at lwt/egress */
                bool success_on_tc;
        } tests[] = {
                /* Empty packets are always rejected. */
@@ -57,6 +58,7 @@ void test_empty_skb(void)
                        .data_size_in = sizeof(eth_hlen),
                        .ifindex = &veth_ifindex,
                        .ret = -ERANGE,
+                       .lwt_egress_ret = -ERANGE,
                        .success_on_tc = true,
                },
                {
@@ -70,6 +72,7 @@ void test_empty_skb(void)
                        .data_size_in = sizeof(eth_hlen),
                        .ifindex = &ipip_ifindex,
                        .ret = -ERANGE,
+                       .lwt_egress_ret = -ERANGE,
                },
 
                /* ETH_HLEN+1-sized packet should be redirected. */
@@ -79,6 +82,7 @@ void test_empty_skb(void)
                        .data_in = eth_hlen_pp,
                        .data_size_in = sizeof(eth_hlen_pp),
                        .ifindex = &veth_ifindex,
+                       .lwt_egress_ret = 1, /* veth_xmit NET_XMIT_DROP */
                },
                {
                        .msg = "ipip ETH_HLEN+1 packet ingress",
@@ -108,8 +112,12 @@ void test_empty_skb(void)
 
        for (i = 0; i < ARRAY_SIZE(tests); i++) {
                bpf_object__for_each_program(prog, bpf_obj->obj) {
-                       char buf[128];
+                       bool at_egress = strstr(bpf_program__name(prog), "egress") != NULL;
                        bool at_tc = !strncmp(bpf_program__section_name(prog), "tc", 2);
+                       int expected_ret;
+                       char buf[128];
+
+                       expected_ret = at_egress && !at_tc ? tests[i].lwt_egress_ret : tests[i].ret;
 
                        tattr.data_in = tests[i].data_in;
                        tattr.data_size_in = tests[i].data_size_in;
@@ -128,7 +136,7 @@ void test_empty_skb(void)
                        if (at_tc && tests[i].success_on_tc)
                                ASSERT_GE(bpf_obj->bss->ret, 0, buf);
                        else
-                               ASSERT_EQ(bpf_obj->bss->ret, tests[i].ret, buf);
+                               ASSERT_EQ(bpf_obj->bss->ret, expected_ret, buf);
                }
        }