netdev - [PATCH net-next v2 1/6] bpf: Fix tcp_synrto

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Date:   Fri, 10 Nov 2017 22:19:50 -0800
From:   Lawrence Brakmo <brakmo@...com>
To:     netdev <netdev@...r.kernel.org>
CC:     Alexei Starovoitov <ast@...com>,
        Daniel Borkmann <daniel@...earbox.net>
Subject: [PATCH net-next v2 1/6] bpf: Fix tcp_synrto_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@...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;
 
-- 
2.9.5