net: bpf: Allow TC programs to call BPF_FUNC_skb_change_head

commit 36bf5c22422a518f0e95318ad0e8f6e167947cab upstream.

This allows TC eBPF programs to modify and forward (redirect) packets
from interfaces without ethernet headers (for example cellular)
to interfaces with (for example ethernet/wifi).

The lack of this appears to simply be an oversight.

Tested:
  in active use in Android R on 4.14+ devices for ipv6
  cellular to wifi tethering offload.

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/core/filter.c b/net/core/filter.c
index 72bf78032f4586b49adc96f7aab4e447262cf2bb..e81f7772161a928859051f29871fc331dfab9b1c 100644 (file)
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6196,6 +6196,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
                return &bpf_skb_adjust_room_proto;
        case BPF_FUNC_skb_change_tail:
                return &bpf_skb_change_tail_proto;
+       case BPF_FUNC_skb_change_head:
+               return &bpf_skb_change_head_proto;
        case BPF_FUNC_skb_get_tunnel_key:
                return &bpf_skb_get_tunnel_key_proto;
        case BPF_FUNC_skb_set_tunnel_key: