bpf: Fix tcp_clamp_kern.c sample program

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

Fixes: 390ee7e29f ("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>
This commit is contained in:
Lawrence Brakmo 2017-11-10 22:19:55 -08:00 committed by David S. Miller
parent e1853319fc
commit 03e982eed4

View file

@ -41,8 +41,10 @@ int bpf_clamp(struct bpf_sock_ops *skops)
/* For testing purposes, only execute rest of BPF program
* if neither port numberis 55601
*/
if (bpf_ntohl(skops->remote_port) != 55601 && skops->local_port != 55601)
return -1;
if (bpf_ntohl(skops->remote_port) != 55601 && skops->local_port != 55601) {
skops->reply = -1;
return 0;
}
op = (int) skops->op;
@ -66,9 +68,9 @@ int bpf_clamp(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:
rv = bpf_setsockopt(skops, SOL_TCP,
@ -80,12 +82,12 @@ int bpf_clamp(struct bpf_sock_ops *skops)
rv = bpf_setsockopt(skops, SOL_TCP,
TCP_BPF_SNDCWND_CLAMP,
&clamp, sizeof(clamp));
rv = rv*100 + 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_SNDBUF, &bufsize,
sizeof(bufsize));
rv += bpf_setsockopt(skops, SOL_SOCKET,
SO_RCVBUF, &bufsize,
sizeof(bufsize));
break;
default:
rv = -1;