[PATCH net-next v5 3/5] net: hdlc_fr: Do skb_reset_mac_header for skbs received on normal PVC devices

[Xie He]

When an skb is received on a normal (non-Ethernet-emulating) PVC device,
call skb_reset_mac_header before we pass it to upper layers.

This is because normal PVC devices don't have header_ops, so any header we
have would not be visible to upper layer code when sending, so the header
shouldn't be visible to upper layer code when receiving, either.

Cc: Willem de Bruijn <willemdebruijn.ker...@gmail.com>
Cc: Krzysztof Halasa <k...@pm.waw.pl>
Acked-by: Willem de Bruijn <will...@google.com>
Signed-off-by: Xie He <xie.he.0...@gmail.com>
---
 drivers/net/wan/hdlc_fr.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wan/hdlc_fr.c b/drivers/net/wan/hdlc_fr.c
index 71ee9b60d91b..eb83116aa9df 100644
--- a/drivers/net/wan/hdlc_fr.c
+++ b/drivers/net/wan/hdlc_fr.c
@@ -935,6 +935,7 @@ static int fr_rx(struct sk_buff *skb)
                skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
                skb->dev = pvc->main;
                skb->protocol = htons(ETH_P_IP);
+               skb_reset_mac_header(skb);
 
        } else if (data[3] == NLPID_IPV6) {
                if (!pvc->main)
@@ -942,6 +943,7 @@ static int fr_rx(struct sk_buff *skb)
                skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
                skb->dev = pvc->main;
                skb->protocol = htons(ETH_P_IPV6);
+               skb_reset_mac_header(skb);
 
        } else if (skb->len > 10 && data[3] == FR_PAD &&
                   data[4] == NLPID_SNAP && data[5] == FR_PAD) {
@@ -958,6 +960,7 @@ static int fr_rx(struct sk_buff *skb)
                                goto rx_drop;
                        skb->dev = pvc->main;
                        skb->protocol = htons(pid);
+                       skb_reset_mac_header(skb);
                        break;
 
                case 0x80C20007: /* bridged Ethernet frame */
-- 
2.27.0