[PATCH bpf-next 1/5] selftests/bpf: sockmap_redir: Simplify try_recv()

[Michal Luczaj]

try_recv() was meant to support both @expect_success cases, but all the
callers use @expect_success=false anyway. Drop the unused logic and fold in
MSG_DONTWAIT. Adapt callers.

Subtle change here: recv() return value of 0 will also be considered (an
unexpected) success.

Signed-off-by: Michal Luczaj <m...@rbox.co>
---
 .../selftests/bpf/prog_tests/sockmap_redir.c       | 25 +++++++++-------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_redir.c 
b/tools/testing/selftests/bpf/prog_tests/sockmap_redir.c
index 
9c461d93113db20de65ac353f92dfdbe32ffbd3b..c1bf1076e8152b7d83c3e07e2dce746b5a39cf7e
 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_redir.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_redir.c
@@ -144,17 +144,14 @@ static void get_redir_params(struct redir_spec *redir,
                *redirect_flags = 0;
 }
 
-static void try_recv(const char *prefix, int fd, int flags, bool 
expect_success)
+static void fail_recv(const char *prefix, int fd, int more_flags)
 {
        ssize_t n;
        char buf;
 
-       errno = 0;
-       n = recv(fd, &buf, 1, flags);
-       if (n < 0 && expect_success)
-               FAIL_ERRNO("%s: unexpected failure: retval=%zd", prefix, n);
-       if (!n && !expect_success)
-               FAIL("%s: expected failure: retval=%zd", prefix, n);
+       n = recv(fd, &buf, 1, MSG_DONTWAIT | more_flags);
+       if (n >= 0)
+               FAIL("%s: unexpected success: retval=%zd", prefix, n);
 }
 
 static void handle_unsupported(int sd_send, int sd_peer, int sd_in, int sd_out,
@@ -188,13 +185,13 @@ static void handle_unsupported(int sd_send, int sd_peer, 
int sd_in, int sd_out,
        }
 
        /* Ensure queues are empty */
-       try_recv("bpf.recv(sd_send)", sd_send, MSG_DONTWAIT, false);
+       fail_recv("bpf.recv(sd_send)", sd_send, 0);
        if (sd_in != sd_send)
-               try_recv("bpf.recv(sd_in)", sd_in, MSG_DONTWAIT, false);
+               fail_recv("bpf.recv(sd_in)", sd_in, 0);
 
-       try_recv("bpf.recv(sd_out)", sd_out, MSG_DONTWAIT, false);
+       fail_recv("bpf.recv(sd_out)", sd_out, 0);
        if (sd_recv != sd_out)
-               try_recv("bpf.recv(sd_recv)", sd_recv, MSG_DONTWAIT, false);
+               fail_recv("bpf.recv(sd_recv)", sd_recv, 0);
 }
 
 static void test_send_redir_recv(int sd_send, int send_flags, int sd_peer,
@@ -257,15 +254,13 @@ static void test_send_redir_recv(int sd_send, int 
send_flags, int sd_peer,
 
        if (send_flags & MSG_OOB) {
                /* Fail reading OOB while in sockmap */
-               try_recv("bpf.recv(sd_out, MSG_OOB)", sd_out,
-                        MSG_OOB | MSG_DONTWAIT, false);
+               fail_recv("bpf.recv(sd_out, MSG_OOB)", sd_out, MSG_OOB);
 
                /* Remove sd_out from sockmap */
                xbpf_map_delete_elem(maps->out, &u32(0));
 
                /* Check that OOB was dropped on redirect */
-               try_recv("recv(sd_out, MSG_OOB)", sd_out,
-                        MSG_OOB | MSG_DONTWAIT, false);
+               fail_recv("recv(sd_out, MSG_OOB)", sd_out, MSG_OOB);
 
                goto del_in;
        }

-- 
2.50.1