1 files changed, 198 insertions, 100 deletions

diff --git a/drivers/net/usb/ipheth.c b/drivers/net/usb/ipheth.c
index 3d8a70d3ea9b..a19789b57190 100644
--- a/drivers/net/usb/ipheth.c
+++ b/drivers/net/usb/ipheth.c
@@ -52,26 +52,31 @@
 #include <linux/ethtool.h>
 #include <linux/usb.h>
 #include <linux/workqueue.h>
+#include <linux/usb/cdc.h>
 
 #define USB_VENDOR_APPLE        0x05ac
-#define USB_PRODUCT_IPHONE      0x1290
-#define USB_PRODUCT_IPHONE_3G   0x1292
-#define USB_PRODUCT_IPHONE_3GS  0x1294
-#define USB_PRODUCT_IPHONE_4	0x1297
-#define USB_PRODUCT_IPAD 0x129a
-#define USB_PRODUCT_IPAD_2	0x12a2
-#define USB_PRODUCT_IPAD_3	0x12a6
-#define USB_PRODUCT_IPAD_MINI    0x12ab
-#define USB_PRODUCT_IPHONE_4_VZW 0x129c
-#define USB_PRODUCT_IPHONE_4S	0x12a0
-#define USB_PRODUCT_IPHONE_5	0x12a8
 
 #define IPHETH_USBINTF_CLASS    255
 #define IPHETH_USBINTF_SUBCLASS 253
 #define IPHETH_USBINTF_PROTO    1
 
-#define IPHETH_BUF_SIZE         1516
 #define IPHETH_IP_ALIGN		2	/* padding at front of URB */
+/* On iOS devices, NCM headers in RX have a fixed size regardless of DPE count:
+ * - NTH16 (NCMH): 12 bytes, as per CDC NCM 1.0 spec
+ * - NDP16 (NCM0): 96 bytes, of which
+ *    - NDP16 fixed header: 8 bytes
+ *    - maximum of 22 DPEs (21 datagrams + trailer), 4 bytes each
+ */
+#define IPHETH_NDP16_MAX_DPE	22
+#define IPHETH_NDP16_HEADER_SIZE (sizeof(struct usb_cdc_ncm_ndp16) + \
+				  IPHETH_NDP16_MAX_DPE * \
+				  sizeof(struct usb_cdc_ncm_dpe16))
+#define IPHETH_NCM_HEADER_SIZE	(sizeof(struct usb_cdc_ncm_nth16) + \
+				 IPHETH_NDP16_HEADER_SIZE)
+#define IPHETH_TX_BUF_SIZE      ETH_FRAME_LEN
+#define IPHETH_RX_BUF_SIZE_LEGACY (IPHETH_IP_ALIGN + ETH_FRAME_LEN)
+#define IPHETH_RX_BUF_SIZE_NCM	65536
+
 #define IPHETH_TX_TIMEOUT       (5 * HZ)
 
 #define IPHETH_INTFNUM          2
@@ -82,56 +87,16 @@
 #define IPHETH_CTRL_TIMEOUT     (5 * HZ)
 
 #define IPHETH_CMD_GET_MACADDR   0x00
+#define IPHETH_CMD_ENABLE_NCM    0x04
 #define IPHETH_CMD_CARRIER_CHECK 0x45
 
 #define IPHETH_CARRIER_CHECK_TIMEOUT round_jiffies_relative(1 * HZ)
 #define IPHETH_CARRIER_ON       0x04
 
 static const struct usb_device_id ipheth_table[] = {
-	{ USB_DEVICE_AND_INTERFACE_INFO(
-		USB_VENDOR_APPLE, USB_PRODUCT_IPHONE,
-		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
-		IPHETH_USBINTF_PROTO) },
-	{ USB_DEVICE_AND_INTERFACE_INFO(
-		USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_3G,
-		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
-		IPHETH_USBINTF_PROTO) },
-	{ USB_DEVICE_AND_INTERFACE_INFO(
-		USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_3GS,
-		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
-		IPHETH_USBINTF_PROTO) },
-	{ USB_DEVICE_AND_INTERFACE_INFO(
-		USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_4,
-		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
-		IPHETH_USBINTF_PROTO) },
-	{ USB_DEVICE_AND_INTERFACE_INFO(
-		USB_VENDOR_APPLE, USB_PRODUCT_IPAD,
-		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
-		IPHETH_USBINTF_PROTO) },
-	{ USB_DEVICE_AND_INTERFACE_INFO(
-		USB_VENDOR_APPLE, USB_PRODUCT_IPAD_2,
-		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
-		IPHETH_USBINTF_PROTO) },
-	{ USB_DEVICE_AND_INTERFACE_INFO(
-		USB_VENDOR_APPLE, USB_PRODUCT_IPAD_3,
-		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
-		IPHETH_USBINTF_PROTO) },
-	{ USB_DEVICE_AND_INTERFACE_INFO(
-		USB_VENDOR_APPLE, USB_PRODUCT_IPAD_MINI,
-		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
-		IPHETH_USBINTF_PROTO) },
-	{ USB_DEVICE_AND_INTERFACE_INFO(
-		USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_4_VZW,
-		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
-		IPHETH_USBINTF_PROTO) },
-	{ USB_DEVICE_AND_INTERFACE_INFO(
-		USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_4S,
-		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
-		IPHETH_USBINTF_PROTO) },
-	{ USB_DEVICE_AND_INTERFACE_INFO(
-		USB_VENDOR_APPLE, USB_PRODUCT_IPHONE_5,
-		IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
-		IPHETH_USBINTF_PROTO) },
+	{ USB_VENDOR_AND_INTERFACE_INFO(USB_VENDOR_APPLE, IPHETH_USBINTF_CLASS,
+					IPHETH_USBINTF_SUBCLASS,
+					IPHETH_USBINTF_PROTO) },
 	{ }
 };
 MODULE_DEVICE_TABLE(usb, ipheth_table);
@@ -149,6 +114,8 @@ struct ipheth_device {
 	u8 bulk_out;
 	struct delayed_work carrier_work;
 	bool confirmed_pairing;
+	int (*rcvbulk_callback)(struct urb *urb);
+	size_t rx_buf_len;
 };
 
 static int ipheth_rx_submit(struct ipheth_device *dev, gfp_t mem_flags);
@@ -168,12 +135,12 @@ static int ipheth_alloc_urbs(struct ipheth_device *iphone)
 	if (rx_urb == NULL)
 		goto free_tx_urb;
 
-	tx_buf = usb_alloc_coherent(iphone->udev, IPHETH_BUF_SIZE,
+	tx_buf = usb_alloc_coherent(iphone->udev, IPHETH_TX_BUF_SIZE,
 				    GFP_KERNEL, &tx_urb->transfer_dma);
 	if (tx_buf == NULL)
 		goto free_rx_urb;
 
-	rx_buf = usb_alloc_coherent(iphone->udev, IPHETH_BUF_SIZE,
+	rx_buf = usb_alloc_coherent(iphone->udev, iphone->rx_buf_len,
 				    GFP_KERNEL, &rx_urb->transfer_dma);
 	if (rx_buf == NULL)
 		goto free_tx_buf;
@@ -186,7 +153,7 @@ static int ipheth_alloc_urbs(struct ipheth_device *iphone)
 	return 0;
 
 free_tx_buf:
-	usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, tx_buf,
+	usb_free_coherent(iphone->udev, IPHETH_TX_BUF_SIZE, tx_buf,
 			  tx_urb->transfer_dma);
 free_rx_urb:
 	usb_free_urb(rx_urb);
@@ -198,9 +165,9 @@ error_nomem:
 
 static void ipheth_free_urbs(struct ipheth_device *iphone)
 {
-	usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, iphone->rx_buf,
+	usb_free_coherent(iphone->udev, iphone->rx_buf_len, iphone->rx_buf,
 			  iphone->rx_urb->transfer_dma);
-	usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, iphone->tx_buf,
+	usb_free_coherent(iphone->udev, IPHETH_TX_BUF_SIZE, iphone->tx_buf,
 			  iphone->tx_urb->transfer_dma);
 	usb_free_urb(iphone->rx_urb);
 	usb_free_urb(iphone->tx_urb);
@@ -212,15 +179,116 @@ static void ipheth_kill_urbs(struct ipheth_device *dev)
 	usb_kill_urb(dev->rx_urb);
 }
 
-static void ipheth_rcvbulk_callback(struct urb *urb)
+static int ipheth_consume_skb(char *buf, int len, struct ipheth_device *dev)
 {
-	struct ipheth_device *dev;
 	struct sk_buff *skb;
-	int status;
+
+	skb = dev_alloc_skb(len);
+	if (!skb) {
+		dev->net->stats.rx_dropped++;
+		return -ENOMEM;
+	}
+
+	skb_put_data(skb, buf, len);
+	skb->dev = dev->net;
+	skb->protocol = eth_type_trans(skb, dev->net);
+
+	dev->net->stats.rx_packets++;
+	dev->net->stats.rx_bytes += len;
+	netif_rx(skb);
+
+	return 0;
+}
+
+static int ipheth_rcvbulk_callback_legacy(struct urb *urb)
+{
+	struct ipheth_device *dev;
 	char *buf;
 	int len;
 
 	dev = urb->context;
+
+	if (urb->actual_length <= IPHETH_IP_ALIGN) {
+		dev->net->stats.rx_length_errors++;
+		return -EINVAL;
+	}
+	len = urb->actual_length - IPHETH_IP_ALIGN;
+	buf = urb->transfer_buffer + IPHETH_IP_ALIGN;
+
+	return ipheth_consume_skb(buf, len, dev);
+}
+
+/* In "NCM mode", the iOS device encapsulates RX (phone->computer) traffic
+ * in NCM Transfer Blocks (similarly to CDC NCM). However, unlike reverse
+ * tethering (handled by the `cdc_ncm` driver), regular tethering is not
+ * compliant with the CDC NCM spec, as the device is missing the necessary
+ * descriptors, and TX (computer->phone) traffic is not encapsulated
+ * at all. Thus `ipheth` implements a very limited subset of the spec with
+ * the sole purpose of parsing RX URBs.
+ */
+static int ipheth_rcvbulk_callback_ncm(struct urb *urb)
+{
+	struct usb_cdc_ncm_nth16 *ncmh;
+	struct usb_cdc_ncm_ndp16 *ncm0;
+	struct usb_cdc_ncm_dpe16 *dpe;
+	struct ipheth_device *dev;
+	u16 dg_idx, dg_len;
+	int retval = -EINVAL;
+	char *buf;
+
+	dev = urb->context;
+
+	if (urb->actual_length < IPHETH_NCM_HEADER_SIZE) {
+		dev->net->stats.rx_length_errors++;
+		return retval;
+	}
+
+	ncmh = urb->transfer_buffer;
+	if (ncmh->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN) ||
+	    /* On iOS, NDP16 directly follows NTH16 */
+	    ncmh->wNdpIndex != cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16)))
+		goto rx_error;
+
+	ncm0 = urb->transfer_buffer + sizeof(struct usb_cdc_ncm_nth16);
+	if (ncm0->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN))
+		goto rx_error;
+
+	dpe = ncm0->dpe16;
+	for (int dpe_i = 0; dpe_i < IPHETH_NDP16_MAX_DPE; ++dpe_i, ++dpe) {
+		dg_idx = le16_to_cpu(dpe->wDatagramIndex);
+		dg_len = le16_to_cpu(dpe->wDatagramLength);
+
+		/* Null DPE must be present after last datagram pointer entry
+		 * (3.3.1 USB CDC NCM spec v1.0)
+		 */
+		if (dg_idx == 0 && dg_len == 0)
+			return 0;
+
+		if (dg_idx < IPHETH_NCM_HEADER_SIZE ||
+		    dg_idx >= urb->actual_length ||
+		    dg_len > urb->actual_length - dg_idx) {
+			dev->net->stats.rx_length_errors++;
+			return retval;
+		}
+
+		buf = urb->transfer_buffer + dg_idx;
+
+		retval = ipheth_consume_skb(buf, dg_len, dev);
+		if (retval != 0)
+			return retval;
+	}
+
+rx_error:
+	dev->net->stats.rx_errors++;
+	return retval;
+}
+
+static void ipheth_rcvbulk_callback(struct urb *urb)
+{
+	struct ipheth_device *dev;
+	int retval, status;
+
+	dev = urb->context;
 	if (dev == NULL)
 		return;
 
@@ -239,29 +307,32 @@ static void ipheth_rcvbulk_callback(struct urb *urb)
 		return;
 	}
 
-	if (urb->actual_length <= IPHETH_IP_ALIGN) {
-		dev->net->stats.rx_length_errors++;
-		return;
-	}
-	len = urb->actual_length - IPHETH_IP_ALIGN;
-	buf = urb->transfer_buffer + IPHETH_IP_ALIGN;
-
-	skb = dev_alloc_skb(len);
-	if (!skb) {
-		dev_err(&dev->intf->dev, "%s: dev_alloc_skb: -ENOMEM\n",
-			__func__);
-		dev->net->stats.rx_dropped++;
-		return;
+	/* iPhone may periodically send URBs with no payload
+	 * on the "bulk in" endpoint. It is safe to ignore them.
+	 */
+	if (urb->actual_length == 0)
+		goto rx_submit;
+
+	/* RX URBs starting with 0x00 0x01 do not encapsulate Ethernet frames,
+	 * but rather are control frames. Their purpose is not documented, and
+	 * they don't affect driver functionality, okay to drop them.
+	 * There is usually just one 4-byte control frame as the very first
+	 * URB received from the bulk IN endpoint.
+	 */
+	if (unlikely
+		(urb->actual_length == 4 &&
+		 ((char *)urb->transfer_buffer)[0] == 0 &&
+		 ((char *)urb->transfer_buffer)[1] == 1))
+		goto rx_submit;
+
+	retval = dev->rcvbulk_callback(urb);
+	if (retval != 0) {
+		dev_err(&dev->intf->dev, "%s: callback retval: %d\n",
+			__func__, retval);
 	}
 
-	skb_put_data(skb, buf, len);
-	skb->dev = dev->net;
-	skb->protocol = eth_type_trans(skb, dev->net);
-
-	dev->net->stats.rx_packets++;
-	dev->net->stats.rx_bytes += len;
+rx_submit:
 	dev->confirmed_pairing = true;
-	netif_rx(skb);
 	ipheth_rx_submit(dev, GFP_ATOMIC);
 }
 
@@ -293,8 +364,6 @@ static int ipheth_carrier_set(struct ipheth_device *dev)
 	struct usb_device *udev;
 	int retval;
 
-	if (!dev)
-		return 0;
 	if (!dev->confirmed_pairing)
 		return 0;
 
@@ -307,13 +376,14 @@ static int ipheth_carrier_set(struct ipheth_device *dev)
 			0x02, /* index */
 			dev->ctrl_buf, IPHETH_CTRL_BUF_SIZE,
 			IPHETH_CTRL_TIMEOUT);
-	if (retval < 0) {
+	if (retval <= 0) {
 		dev_err(&dev->intf->dev, "%s: usb_control_msg: %d\n",
 			__func__, retval);
 		return retval;
 	}
 
-	if (dev->ctrl_buf[0] == IPHETH_CARRIER_ON) {
+	if ((retval == 1 && dev->ctrl_buf[0] == IPHETH_CARRIER_ON) ||
+	    (retval >= 2 && dev->ctrl_buf[1] == IPHETH_CARRIER_ON)) {
 		netif_carrier_on(dev->net);
 		if (dev->tx_urb->status != -EINPROGRESS)
 			netif_wake_queue(dev->net);
@@ -357,13 +427,34 @@ static int ipheth_get_macaddr(struct ipheth_device *dev)
 			__func__, retval);
 		retval = -EINVAL;
 	} else {
-		memcpy(net->dev_addr, dev->ctrl_buf, ETH_ALEN);
+		eth_hw_addr_set(net, dev->ctrl_buf);
 		retval = 0;
 	}
 
 	return retval;
 }
 
+static int ipheth_enable_ncm(struct ipheth_device *dev)
+{
+	struct usb_device *udev = dev->udev;
+	int retval;
+
+	retval = usb_control_msg(udev,
+				 usb_sndctrlpipe(udev, IPHETH_CTRL_ENDP),
+				 IPHETH_CMD_ENABLE_NCM, /* request */
+				 0x41, /* request type */
+				 0x00, /* value */
+				 0x02, /* index */
+				 NULL,
+				 0,
+				 IPHETH_CTRL_TIMEOUT);
+
+	dev_info(&dev->intf->dev, "%s: usb_control_msg: %d\n",
+		 __func__, retval);
+
+	return retval;
+}
+
 static int ipheth_rx_submit(struct ipheth_device *dev, gfp_t mem_flags)
 {
 	struct usb_device *udev = dev->udev;
@@ -371,7 +462,7 @@ static int ipheth_rx_submit(struct ipheth_device *dev, gfp_t mem_flags)
 
 	usb_fill_bulk_urb(dev->rx_urb, udev,
 			  usb_rcvbulkpipe(udev, dev->bulk_in),
-			  dev->rx_buf, IPHETH_BUF_SIZE,
+			  dev->rx_buf, dev->rx_buf_len,
 			  ipheth_rcvbulk_callback,
 			  dev);
 	dev->rx_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
@@ -407,19 +498,19 @@ static int ipheth_close(struct net_device *net)
 {
 	struct ipheth_device *dev = netdev_priv(net);
 
-	cancel_delayed_work_sync(&dev->carrier_work);
 	netif_stop_queue(net);
+	cancel_delayed_work_sync(&dev->carrier_work);
 	return 0;
 }
 
-static int ipheth_tx(struct sk_buff *skb, struct net_device *net)
+static netdev_tx_t ipheth_tx(struct sk_buff *skb, struct net_device *net)
 {
 	struct ipheth_device *dev = netdev_priv(net);
 	struct usb_device *udev = dev->udev;
 	int retval;
 
 	/* Paranoid */
-	if (skb->len > IPHETH_BUF_SIZE) {
+	if (skb->len > IPHETH_TX_BUF_SIZE) {
 		WARN(1, "%s: skb too large: %d bytes\n", __func__, skb->len);
 		dev->net->stats.tx_dropped++;
 		dev_kfree_skb_any(skb);
@@ -427,33 +518,32 @@ static int ipheth_tx(struct sk_buff *skb, struct net_device *net)
 	}
 
 	memcpy(dev->tx_buf, skb->data, skb->len);
-	if (skb->len < IPHETH_BUF_SIZE)
-		memset(dev->tx_buf + skb->len, 0, IPHETH_BUF_SIZE - skb->len);
 
 	usb_fill_bulk_urb(dev->tx_urb, udev,
 			  usb_sndbulkpipe(udev, dev->bulk_out),
-			  dev->tx_buf, IPHETH_BUF_SIZE,
+			  dev->tx_buf, skb->len,
 			  ipheth_sndbulk_callback,
 			  dev);
 	dev->tx_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 
+	netif_stop_queue(net);
 	retval = usb_submit_urb(dev->tx_urb, GFP_ATOMIC);
 	if (retval) {
 		dev_err(&dev->intf->dev, "%s: usb_submit_urb: %d\n",
 			__func__, retval);
 		dev->net->stats.tx_errors++;
 		dev_kfree_skb_any(skb);
+		netif_wake_queue(net);
 	} else {
 		dev->net->stats.tx_packets++;
 		dev->net->stats.tx_bytes += skb->len;
 		dev_consume_skb_any(skb);
-		netif_stop_queue(net);
 	}
 
 	return NETDEV_TX_OK;
 }
 
-static void ipheth_tx_timeout(struct net_device *net)
+static void ipheth_tx_timeout(struct net_device *net, unsigned int txqueue)
 {
 	struct ipheth_device *dev = netdev_priv(net);
 
@@ -496,13 +586,15 @@ static int ipheth_probe(struct usb_interface *intf,
 
 	netdev->netdev_ops = &ipheth_netdev_ops;
 	netdev->watchdog_timeo = IPHETH_TX_TIMEOUT;
-	strcpy(netdev->name, "eth%d");
+	strscpy(netdev->name, "eth%d", sizeof(netdev->name));
 
 	dev = netdev_priv(netdev);
 	dev->udev = udev;
 	dev->net = netdev;
 	dev->intf = intf;
 	dev->confirmed_pairing = false;
+	dev->rx_buf_len = IPHETH_RX_BUF_SIZE_LEGACY;
+	dev->rcvbulk_callback = ipheth_rcvbulk_callback_legacy;
 	/* Set up endpoints */
 	hintf = usb_altnum_to_altsetting(intf, IPHETH_ALT_INTFNUM);
 	if (hintf == NULL) {
@@ -534,6 +626,12 @@ static int ipheth_probe(struct usb_interface *intf,
 	if (retval)
 		goto err_get_macaddr;
 
+	retval = ipheth_enable_ncm(dev);
+	if (!retval) {
+		dev->rx_buf_len = IPHETH_RX_BUF_SIZE_NCM;
+		dev->rcvbulk_callback = ipheth_rcvbulk_callback_ncm;
+	}
+
 	INIT_DELAYED_WORK(&dev->carrier_work, ipheth_carrier_check_work);
 
 	retval = ipheth_alloc_urbs(dev);
@@ -563,8 +661,8 @@ err_register_netdev:
 	ipheth_free_urbs(dev);
 err_alloc_urbs:
 err_get_macaddr:
-err_alloc_ctrl_buf:
 	kfree(dev->ctrl_buf);
+err_alloc_ctrl_buf:
 err_endpoints:
 	free_netdev(netdev);
 	return retval;