bpf: Fix tcp_bufs_kern.c sample program

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

Fixes: 390ee7e29fc8 ("bpf: enforce return code for cgroup-bpf programs")
Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/samples/bpf/tcp_bufs_kern.c b/samples/bpf/tcp_bufs_kern.c
index ee83bbabd17c4f1622c1f3efc66fb03443e53b1c..0566b7fa38a108bf4f7f98ece2d51c3397195b74 100644 (file)
--- a/samples/bpf/tcp_bufs_kern.c
+++ b/samples/bpf/tcp_bufs_kern.c
@@ -41,8 +41,10 @@ int bpf_bufs(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;
 
@@ -61,8 +63,8 @@ int bpf_bufs(struct bpf_sock_ops *skops)
                /* Set sndbuf and rcvbuf of active connections */
                rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
                                    sizeof(bufsize));
-               rv = rv*100 + bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
-                                            &bufsize, sizeof(bufsize));
+               rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
+                                    &bufsize, sizeof(bufsize));
                break;
        case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
                /* Nothing to do */
@@ -71,8 +73,8 @@ int bpf_bufs(struct bpf_sock_ops *skops)
                /* Set sndbuf and rcvbuf of passive connections */
                rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
                                    sizeof(bufsize));
-               rv = rv*100 + bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
-                                            &bufsize, sizeof(bufsize));
+               rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
+                                    &bufsize, sizeof(bufsize));
                break;
        default:
                rv = -1;