3 files changed, 108 insertions, 18 deletions

diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c
index 673e362..32a7605 100644
--- a/drivers/net/usb/cdc_mbim.c
+++ b/drivers/net/usb/cdc_mbim.c
@@ -134,7 +134,7 @@ static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb
 		goto error;
 
 	if (skb) {
-		if (skb->len <= sizeof(ETH_HLEN))
+		if (skb->len <= ETH_HLEN)
 			goto error;
 
 		/* mapping VLANs to MBIM sessions:
diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index e2dd324..cba1d46 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -1925,7 +1925,6 @@ static void hso_std_serial_write_bulk_callback(struct urb *urb)
 {
 	struct hso_serial *serial = urb->context;
 	int status = urb->status;
-	struct tty_struct *tty;
 
 	/* sanity check */
 	if (!serial) {
@@ -1941,11 +1940,7 @@ static void hso_std_serial_write_bulk_callback(struct urb *urb)
 		return;
 	}
 	hso_put_activity(serial->parent);
-	tty = tty_port_tty_get(&serial->port);
-	if (tty) {
-		tty_wakeup(tty);
-		tty_kref_put(tty);
-	}
+	tty_port_tty_wakeup(&serial->port);
 	hso_kick_transmit(serial);
 
 	D1(" ");
@@ -2008,12 +2003,8 @@ static void ctrl_callback(struct urb *urb)
 		put_rxbuf_data_and_resubmit_ctrl_urb(serial);
 		spin_unlock(&serial->serial_lock);
 	} else {
-		struct tty_struct *tty = tty_port_tty_get(&serial->port);
 		hso_put_activity(serial->parent);
-		if (tty) {
-			tty_wakeup(tty);
-			tty_kref_put(tty);
-		}
+		tty_port_tty_wakeup(&serial->port);
 		/* response to a write command */
 		hso_kick_transmit(serial);
 	}
@@ -3133,18 +3124,13 @@ static void hso_serial_ref_free(struct kref *ref)
 static void hso_free_interface(struct usb_interface *interface)
 {
 	struct hso_serial *hso_dev;
-	struct tty_struct *tty;
 	int i;
 
 	for (i = 0; i < HSO_SERIAL_TTY_MINORS; i++) {
 		if (serial_table[i] &&
 		    (serial_table[i]->interface == interface)) {
 			hso_dev = dev2ser(serial_table[i]);
-			tty = tty_port_tty_get(&hso_dev->port);
-			if (tty) {
-				tty_hangup(tty);
-				tty_kref_put(tty);
-			}
+			tty_port_tty_hangup(&hso_dev->port, false);
 			mutex_lock(&hso_dev->parent->mutex);
 			hso_dev->parent->usb_gone = 1;
 			mutex_unlock(&hso_dev->parent->mutex);
diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index bdceb74..5a88e72 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/netdevice.h>
 #include <linux/ethtool.h>
+#include <linux/etherdevice.h>
 #include <linux/mii.h>
 #include <linux/usb.h>
 #include <linux/usb/cdc.h>
@@ -52,6 +53,96 @@ struct qmi_wwan_state {
 	struct usb_interface *data;
 };
 
+/* default ethernet address used by the modem */
+static const u8 default_modem_addr[ETH_ALEN] = {0x02, 0x50, 0xf3};
+
+/* Make up an ethernet header if the packet doesn't have one.
+ *
+ * A firmware bug common among several devices cause them to send raw
+ * IP packets under some circumstances.  There is no way for the
+ * driver/host to know when this will happen.  And even when the bug
+ * hits, some packets will still arrive with an intact header.
+ *
+ * The supported devices are only capably of sending IPv4, IPv6 and
+ * ARP packets on a point-to-point link. Any packet with an ethernet
+ * header will have either our address or a broadcast/multicast
+ * address as destination.  ARP packets will always have a header.
+ *
+ * This means that this function will reliably add the appropriate
+ * header iff necessary, provided our hardware address does not start
+ * with 4 or 6.
+ *
+ * Another common firmware bug results in all packets being addressed
+ * to 00:a0:c6:00:00:00 despite the host address being different.
+ * This function will also fixup such packets.
+ */
+static int qmi_wwan_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
+{
+	__be16 proto;
+
+	/* usbnet rx_complete guarantees that skb->len is at least
+	 * hard_header_len, so we can inspect the dest address without
+	 * checking skb->len
+	 */
+	switch (skb->data[0] & 0xf0) {
+	case 0x40:
+		proto = htons(ETH_P_IP);
+		break;
+	case 0x60:
+		proto = htons(ETH_P_IPV6);
+		break;
+	case 0x00:
+		if (is_multicast_ether_addr(skb->data))
+			return 1;
+		/* possibly bogus destination - rewrite just in case */
+		skb_reset_mac_header(skb);
+		goto fix_dest;
+	default:
+		/* pass along other packets without modifications */
+		return 1;
+	}
+	if (skb_headroom(skb) < ETH_HLEN)
+		return 0;
+	skb_push(skb, ETH_HLEN);
+	skb_reset_mac_header(skb);
+	eth_hdr(skb)->h_proto = proto;
+	memset(eth_hdr(skb)->h_source, 0, ETH_ALEN);
+fix_dest:
+	memcpy(eth_hdr(skb)->h_dest, dev->net->dev_addr, ETH_ALEN);
+	return 1;
+}
+
+/* very simplistic detection of IPv4 or IPv6 headers */
+static bool possibly_iphdr(const char *data)
+{
+	return (data[0] & 0xd0) == 0x40;
+}
+
+/* disallow addresses which may be confused with IP headers */
+static int qmi_wwan_mac_addr(struct net_device *dev, void *p)
+{
+	int ret;
+	struct sockaddr *addr = p;
+
+	ret = eth_prepare_mac_addr_change(dev, p);
+	if (ret < 0)
+		return ret;
+	if (possibly_iphdr(addr->sa_data))
+		return -EADDRNOTAVAIL;
+	eth_commit_mac_addr_change(dev, p);
+	return 0;
+}
+
+static const struct net_device_ops qmi_wwan_netdev_ops = {
+	.ndo_open		= usbnet_open,
+	.ndo_stop		= usbnet_stop,
+	.ndo_start_xmit		= usbnet_start_xmit,
+	.ndo_tx_timeout		= usbnet_tx_timeout,
+	.ndo_change_mtu		= usbnet_change_mtu,
+	.ndo_set_mac_address	= qmi_wwan_mac_addr,
+	.ndo_validate_addr	= eth_validate_addr,
+};
+
 /* using a counter to merge subdriver requests with our own into a combined state */
 static int qmi_wwan_manage_power(struct usbnet *dev, int on)
 {
@@ -229,6 +320,18 @@ next_desc:
 		usb_driver_release_interface(driver, info->data);
 	}
 
+	/* Never use the same address on both ends of the link, even
+	 * if the buggy firmware told us to.
+	 */
+	if (!compare_ether_addr(dev->net->dev_addr, default_modem_addr))
+		eth_hw_addr_random(dev->net);
+
+	/* make MAC addr easily distinguishable from an IP header */
+	if (possibly_iphdr(dev->net->dev_addr)) {
+		dev->net->dev_addr[0] |= 0x02;	/* set local assignment bit */
+		dev->net->dev_addr[0] &= 0xbf;	/* clear "IP" bit */
+	}
+	dev->net->netdev_ops = &qmi_wwan_netdev_ops;
 err:
 	return status;
 }
@@ -312,6 +415,7 @@ static const struct driver_info	qmi_wwan_info = {
 	.bind		= qmi_wwan_bind,
 	.unbind		= qmi_wwan_unbind,
 	.manage_power	= qmi_wwan_manage_power,
+	.rx_fixup       = qmi_wwan_rx_fixup,
 };
 
 #define HUAWEI_VENDOR_ID	0x12D1