1 files changed, 412 insertions, 0 deletions
diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c
new file mode 100644
index 000000000000..42f51c71ec1f
--- /dev/null
+++ b/drivers/net/usb/cdc_mbim.c
@@ -0,0 +1,412 @@
+/*
+ * Copyright (c) 2012  Smith Micro Software, Inc.
+ * Copyright (c) 2012  Bjørn Mork <bjorn@mork.no>
+ *
+ * This driver is based on and reuse most of cdc_ncm, which is
+ * Copyright (C) ST-Ericsson 2010-2012
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/ethtool.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/mii.h>
+#include <linux/usb.h>
+#include <linux/usb/cdc.h>
+#include <linux/usb/usbnet.h>
+#include <linux/usb/cdc-wdm.h>
+#include <linux/usb/cdc_ncm.h>
+
+/* driver specific data - must match cdc_ncm usage */
+struct cdc_mbim_state {
+	struct cdc_ncm_ctx *ctx;
+	atomic_t pmcount;
+	struct usb_driver *subdriver;
+	struct usb_interface *control;
+	struct usb_interface *data;
+};
+
+/* using a counter to merge subdriver requests with our own into a combined state */
+static int cdc_mbim_manage_power(struct usbnet *dev, int on)
+{
+	struct cdc_mbim_state *info = (void *)&dev->data;
+	int rv = 0;
+
+	dev_dbg(&dev->intf->dev, "%s() pmcount=%d, on=%d\n", __func__, atomic_read(&info->pmcount), on);
+
+	if ((on && atomic_add_return(1, &info->pmcount) == 1) || (!on && atomic_dec_and_test(&info->pmcount))) {
+		/* need autopm_get/put here to ensure the usbcore sees the new value */
+		rv = usb_autopm_get_interface(dev->intf);
+		if (rv < 0)
+			goto err;
+		dev->intf->needs_remote_wakeup = on;
+		usb_autopm_put_interface(dev->intf);
+	}
+err:
+	return rv;
+}
+
+static int cdc_mbim_wdm_manage_power(struct usb_interface *intf, int status)
+{
+	struct usbnet *dev = usb_get_intfdata(intf);
+
+	/* can be called while disconnecting */
+	if (!dev)
+		return 0;
+
+	return cdc_mbim_manage_power(dev, status);
+}
+
+
+static int cdc_mbim_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+	struct cdc_ncm_ctx *ctx;
+	struct usb_driver *subdriver = ERR_PTR(-ENODEV);
+	int ret = -ENODEV;
+	u8 data_altsetting = CDC_NCM_DATA_ALTSETTING_NCM;
+	struct cdc_mbim_state *info = (void *)&dev->data;
+
+	/* see if interface supports MBIM alternate setting */
+	if (intf->num_altsetting == 2) {
+		if (!cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
+			usb_set_interface(dev->udev,
+					  intf->cur_altsetting->desc.bInterfaceNumber,
+					  CDC_NCM_COMM_ALTSETTING_MBIM);
+		data_altsetting = CDC_NCM_DATA_ALTSETTING_MBIM;
+	}
+
+	/* Probably NCM, defer for cdc_ncm_bind */
+	if (!cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
+		goto err;
+
+	ret = cdc_ncm_bind_common(dev, intf, data_altsetting);
+	if (ret)
+		goto err;
+
+	ctx = info->ctx;
+
+	/* The MBIM descriptor and the status endpoint are required */
+	if (ctx->mbim_desc && dev->status)
+		subdriver = usb_cdc_wdm_register(ctx->control,
+						 &dev->status->desc,
+						 le16_to_cpu(ctx->mbim_desc->wMaxControlMessage),
+						 cdc_mbim_wdm_manage_power);
+	if (IS_ERR(subdriver)) {
+		ret = PTR_ERR(subdriver);
+		cdc_ncm_unbind(dev, intf);
+		goto err;
+	}
+
+	/* can't let usbnet use the interrupt endpoint */
+	dev->status = NULL;
+	info->subdriver = subdriver;
+
+	/* MBIM cannot do ARP */
+	dev->net->flags |= IFF_NOARP;
+
+	/* no need to put the VLAN tci in the packet headers */
+	dev->net->features |= NETIF_F_HW_VLAN_TX;
+err:
+	return ret;
+}
+
+static void cdc_mbim_unbind(struct usbnet *dev, struct usb_interface *intf)
+{
+	struct cdc_mbim_state *info = (void *)&dev->data;
+	struct cdc_ncm_ctx *ctx = info->ctx;
+
+	/* disconnect subdriver from control interface */
+	if (info->subdriver && info->subdriver->disconnect)
+		info->subdriver->disconnect(ctx->control);
+	info->subdriver = NULL;
+
+	/* let NCM unbind clean up both control and data interface */
+	cdc_ncm_unbind(dev, intf);
+}
+
+
+static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
+{
+	struct sk_buff *skb_out;
+	struct cdc_mbim_state *info = (void *)&dev->data;
+	struct cdc_ncm_ctx *ctx = info->ctx;
+	__le32 sign = cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN);
+	u16 tci = 0;
+	u8 *c;
+
+	if (!ctx)
+		goto error;
+
+	if (skb) {
+		if (skb->len <= sizeof(ETH_HLEN))
+			goto error;
+
+		/* 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:
+				goto error;
+			}
+			c = (u8 *)&sign;
+			c[3] = tci;
+			break;
+		case 0x0100: /* VLAN ID 256 - 511 */
+			sign = cpu_to_le32(USB_CDC_MBIM_NDP16_DSS_SIGN);
+			c = (u8 *)&sign;
+			c[3] = tci;
+			break;
+		default:
+			netif_err(dev, tx_err, dev->net,
+				  "unsupported tci=0x%04x\n", tci);
+			goto error;
+		}
+		skb_pull(skb, ETH_HLEN);
+	}
+
+	spin_lock_bh(&ctx->mtx);
+	skb_out = cdc_ncm_fill_tx_frame(ctx, skb, sign);
+	spin_unlock_bh(&ctx->mtx);
+	return skb_out;
+
+error:
+	if (skb)
+		dev_kfree_skb_any(skb);
+
+	return NULL;
+}
+
+static struct sk_buff *cdc_mbim_process_dgram(struct usbnet *dev, u8 *buf, size_t len, u16 tci)
+{
+	__be16 proto = htons(ETH_P_802_3);
+	struct sk_buff *skb = NULL;
+
+	if (tci < 256) { /* IPS session? */
+		if (len < sizeof(struct iphdr))
+			goto err;
+
+		switch (*buf & 0xf0) {
+		case 0x40:
+			proto = htons(ETH_P_IP);
+			break;
+		case 0x60:
+			proto = htons(ETH_P_IPV6);
+			break;
+		default:
+			goto err;
+		}
+	}
+
+	skb = netdev_alloc_skb_ip_align(dev->net,  len + ETH_HLEN);
+	if (!skb)
+		goto err;
+
+	/* add an ethernet header */
+	skb_put(skb, ETH_HLEN);
+	skb_reset_mac_header(skb);
+	eth_hdr(skb)->h_proto = proto;
+	memset(eth_hdr(skb)->h_source, 0, ETH_ALEN);
+	memcpy(eth_hdr(skb)->h_dest, dev->net->dev_addr, ETH_ALEN);
+
+	/* add datagram */
+	memcpy(skb_put(skb, len), buf, len);
+
+	/* map MBIM session to VLAN */
+	if (tci)
+		vlan_put_tag(skb, tci);
+err:
+	return skb;
+}
+
+static int cdc_mbim_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
+{
+	struct sk_buff *skb;
+	struct cdc_mbim_state *info = (void *)&dev->data;
+	struct cdc_ncm_ctx *ctx = info->ctx;
+	int len;
+	int nframes;
+	int x;
+	int offset;
+	struct usb_cdc_ncm_ndp16 *ndp16;
+	struct usb_cdc_ncm_dpe16 *dpe16;
+	int ndpoffset;
+	int loopcount = 50; /* arbitrary max preventing infinite loop */
+	u8 *c;
+	u16 tci;
+
+	ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
+	if (ndpoffset < 0)
+		goto error;
+
+next_ndp:
+	nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
+	if (nframes < 0)
+		goto error;
+
+	ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
+
+	switch (ndp16->dwSignature & cpu_to_le32(0x00ffffff)) {
+	case cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN):
+		c = (u8 *)&ndp16->dwSignature;
+		tci = c[3];
+		break;
+	case cpu_to_le32(USB_CDC_MBIM_NDP16_DSS_SIGN):
+		c = (u8 *)&ndp16->dwSignature;
+		tci = c[3] + 256;
+		break;
+	default:
+		netif_dbg(dev, rx_err, dev->net,
+			  "unsupported NDP signature <0x%08x>\n",
+			  le32_to_cpu(ndp16->dwSignature));
+		goto err_ndp;
+
+	}
+
+	dpe16 = ndp16->dpe16;
+	for (x = 0; x < nframes; x++, dpe16++) {
+		offset = le16_to_cpu(dpe16->wDatagramIndex);
+		len = le16_to_cpu(dpe16->wDatagramLength);
+
+		/*
+		 * CDC NCM ch. 3.7
+		 * All entries after first NULL entry are to be ignored
+		 */
+		if ((offset == 0) || (len == 0)) {
+			if (!x)
+				goto err_ndp; /* empty NTB */
+			break;
+		}
+
+		/* sanity checking */
+		if (((offset + len) > skb_in->len) || (len > ctx->rx_max)) {
+			netif_dbg(dev, rx_err, dev->net,
+				  "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
+				  x, offset, len, skb_in);
+			if (!x)
+				goto err_ndp;
+			break;
+		} else {
+			skb = cdc_mbim_process_dgram(dev, skb_in->data + offset, len, tci);
+			if (!skb)
+				goto error;
+			usbnet_skb_return(dev, skb);
+		}
+	}
+err_ndp:
+	/* are there more NDPs to process? */
+	ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
+	if (ndpoffset && loopcount--)
+		goto next_ndp;
+
+	return 1;
+error:
+	return 0;
+}
+
+static int cdc_mbim_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	int ret = 0;
+	struct usbnet *dev = usb_get_intfdata(intf);
+	struct cdc_mbim_state *info = (void *)&dev->data;
+	struct cdc_ncm_ctx *ctx = info->ctx;
+
+	if (ctx == NULL) {
+		ret = -1;
+		goto error;
+	}
+
+	ret = usbnet_suspend(intf, message);
+	if (ret < 0)
+		goto error;
+
+	if (intf == ctx->control && info->subdriver && info->subdriver->suspend)
+		ret = info->subdriver->suspend(intf, message);
+	if (ret < 0)
+		usbnet_resume(intf);
+
+error:
+	return ret;
+}
+
+static int cdc_mbim_resume(struct usb_interface *intf)
+{
+	int  ret = 0;
+	struct usbnet *dev = usb_get_intfdata(intf);
+	struct cdc_mbim_state *info = (void *)&dev->data;
+	struct cdc_ncm_ctx *ctx = info->ctx;
+	bool callsub = (intf == ctx->control && info->subdriver && info->subdriver->resume);
+
+	if (callsub)
+		ret = info->subdriver->resume(intf);
+	if (ret < 0)
+		goto err;
+	ret = usbnet_resume(intf);
+	if (ret < 0 && callsub && info->subdriver->suspend)
+		info->subdriver->suspend(intf, PMSG_SUSPEND);
+err:
+	return ret;
+}
+
+static const struct driver_info cdc_mbim_info = {
+	.description = "CDC MBIM",
+	.flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN,
+	.bind = cdc_mbim_bind,
+	.unbind = cdc_mbim_unbind,
+	.manage_power = cdc_mbim_manage_power,
+	.rx_fixup = cdc_mbim_rx_fixup,
+	.tx_fixup = cdc_mbim_tx_fixup,
+};
+
+static const struct usb_device_id mbim_devs[] = {
+	/* This duplicate NCM entry is intentional. MBIM devices can
+	 * be disguised as NCM by default, and this is necessary to
+	 * allow us to bind the correct driver_info to such devices.
+	 *
+	 * bind() will sort out this for us, selecting the correct
+	 * entry and reject the other
+	 */
+	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
+	  .driver_info = (unsigned long)&cdc_mbim_info,
+	},
+	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
+	  .driver_info = (unsigned long)&cdc_mbim_info,
+	},
+	{
+	},
+};
+MODULE_DEVICE_TABLE(usb, mbim_devs);
+
+static struct usb_driver cdc_mbim_driver = {
+	.name = "cdc_mbim",
+	.id_table = mbim_devs,
+	.probe = usbnet_probe,
+	.disconnect = usbnet_disconnect,
+	.suspend = cdc_mbim_suspend,
+	.resume = cdc_mbim_resume,
+	.reset_resume =	cdc_mbim_resume,
+	.supports_autosuspend = 1,
+	.disable_hub_initiated_lpm = 1,
+};
+module_usb_driver(cdc_mbim_driver);
+
+MODULE_AUTHOR("Greg Suarez <gsuarez@smithmicro.com>");
+MODULE_AUTHOR("Bjørn Mork <bjorn@mork.no>");
+MODULE_DESCRIPTION("USB CDC MBIM host driver");
+MODULE_LICENSE("GPL");