Merge remote-tracking branch 'lsk/v3.10/topic/gator' into linux-linaro-lsk

[firefly-linux-kernel-4.4.55.git] / drivers / net / usb / cdc_mbim.c

diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c
index 25ba7eca9a13bdaa7950627111b2eab88a292447..7cabe4583904ccacb4a803b1ebd509027468a136 100644 (file)
--- a/drivers/net/usb/cdc_mbim.c
+++ b/drivers/net/usb/cdc_mbim.c
@@ -120,6 +120,16 @@ static void cdc_mbim_unbind(struct usbnet *dev, struct usb_interface *intf)
        cdc_ncm_unbind(dev, intf);
 }
 
+/* verify that the ethernet protocol is IPv4 or IPv6 */
+static bool is_ip_proto(__be16 proto)
+{
+       switch (proto) {
+       case htons(ETH_P_IP):
+       case htons(ETH_P_IPV6):
+               return true;
+       }
+       return false;
+}
 
 static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 {
@@ -128,6 +138,7 @@ static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb
        struct cdc_ncm_ctx *ctx = info->ctx;
        __le32 sign = cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN);
        u16 tci = 0;
+       bool is_ip;
        u8 *c;
 
        if (!ctx)
@@ -137,25 +148,32 @@ static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb
                if (skb->len <= ETH_HLEN)
                        goto error;
 
+               /* Some applications using e.g. packet sockets will
+                * bypass the VLAN acceleration and create tagged
+                * ethernet frames directly.  We primarily look for
+                * the accelerated out-of-band tag, but fall back if
+                * required
+                */
+               skb_reset_mac_header(skb);
+               if (vlan_get_tag(skb, &tci) < 0 && skb->len > VLAN_ETH_HLEN &&
+                   __vlan_get_tag(skb, &tci) == 0) {
+                       is_ip = is_ip_proto(vlan_eth_hdr(skb)->h_vlan_encapsulated_proto);
+                       skb_pull(skb, VLAN_ETH_HLEN);
+               } else {
+                       is_ip = is_ip_proto(eth_hdr(skb)->h_proto);
+                       skb_pull(skb, ETH_HLEN);
+               }
+
                /* mapping VLANs to MBIM sessions:
                 *   no tag     => IPS session <0>
                 *   1 - 255    => IPS session <vlanid>
                 *   256 - 511  => DSS session <vlanid - 256>
                 *   512 - 4095 => unsupported, drop
                 */
-               vlan_get_tag(skb, &tci);
-
                switch (tci & 0x0f00) {
                case 0x0000: /* VLAN ID 0 - 255 */
-                       /* verify that datagram is IPv4 or IPv6 */
-                       skb_reset_mac_header(skb);
-                       switch (eth_hdr(skb)->h_proto) {
-                       case htons(ETH_P_IP):
-                       case htons(ETH_P_IPV6):
-                               break;
-                       default:
+                       if (!is_ip)
                                goto error;
-                       }
                        c = (u8 *)&sign;
                        c[3] = tci;
                        break;
@@ -169,7 +187,6 @@ static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb
                                  "unsupported tci=0x%04x\n", tci);
                        goto error;
                }
-               skb_pull(skb, ETH_HLEN);
        }
 
        spin_lock_bh(&ctx->mtx);