Re: [PATCH net-next 1/6] bpf: Fix tcp_synrto_kern.c sample program

[Daniel Borkmann]

On 11/10/2017 09:42 PM, Lawrence Brakmo wrote:

The program was returning -1 in some cases which is not allowed
by the verifier any longer.

Fixes: 8550f328f45d ("bpf: Support for per connection SYN/SYN-ACK RTOs")

Hmm, for most of the series (if not all), I think Fixes tag is:
390ee7e29fc8 ("bpf: enforce return code for cgroup-bpf programs"),
which is the one that started enforcing via check_return_code()
in range [0, 1].

Btw, your subject from cover letter got somehow messed up a bit:

'[PATCH net-next 0/6] bpf: Fix bugs in sock_ops samples In-Reply-To:'

Signed-off-by: Lawrence Brakmo <bra...@fb.com>
---
  samples/bpf/tcp_synrto_kern.c | 6 ++++--
  1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/samples/bpf/tcp_synrto_kern.c b/samples/bpf/tcp_synrto_kern.c
index 3c3fc83..232bb24 100644
--- a/samples/bpf/tcp_synrto_kern.c
+++ b/samples/bpf/tcp_synrto_kern.c
@@ -38,8 +38,10 @@ int bpf_synrto(struct bpf_sock_ops *skops)
         * if neither port numberis 55601
         */
        if (bpf_ntohl(skops->remote_port) != 55601 &&
-           skops->local_port != 55601)
-               return -1;
+           skops->local_port != 55601) {
+               skops->reply = -1;
+               return 1;
+       }

op = (int) skops->op;