1 files changed, 680 insertions, 0 deletions

diff --git a/drivers/usb/gadget/function/f_eem.c b/drivers/usb/gadget/function/f_eem.c
new file mode 100644
index 000000000..5d38f29bd
--- /dev/null
+++ b/drivers/usb/gadget/function/f_eem.c
@@ -0,0 +1,680 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * f_eem.c -- USB CDC Ethernet (EEM) link function driver
+ *
+ * Copyright (C) 2003-2005,2008 David Brownell
+ * Copyright (C) 2008 Nokia Corporation
+ * Copyright (C) 2009 EF Johnson Technologies
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/etherdevice.h>
+#include <linux/crc32.h>
+#include <linux/slab.h>
+
+#include "u_ether.h"
+#include "u_ether_configfs.h"
+#include "u_eem.h"
+
+#define EEM_HLEN 2
+
+/*
+ * This function is a "CDC Ethernet Emulation Model" (CDC EEM)
+ * Ethernet link.
+ */
+
+struct f_eem {
+	struct gether			port;
+	u8				ctrl_id;
+};
+
+struct in_context {
+	struct sk_buff	*skb;
+	struct usb_ep	*ep;
+};
+
+static inline struct f_eem *func_to_eem(struct usb_function *f)
+{
+	return container_of(f, struct f_eem, port.func);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* interface descriptor: */
+
+static struct usb_interface_descriptor eem_intf = {
+	.bLength =		sizeof eem_intf,
+	.bDescriptorType =	USB_DT_INTERFACE,
+
+	/* .bInterfaceNumber = DYNAMIC */
+	.bNumEndpoints =	2,
+	.bInterfaceClass =	USB_CLASS_COMM,
+	.bInterfaceSubClass =	USB_CDC_SUBCLASS_EEM,
+	.bInterfaceProtocol =	USB_CDC_PROTO_EEM,
+	/* .iInterface = DYNAMIC */
+};
+
+/* full speed support: */
+
+static struct usb_endpoint_descriptor eem_fs_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor eem_fs_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_descriptor_header *eem_fs_function[] = {
+	/* CDC EEM control descriptors */
+	(struct usb_descriptor_header *) &eem_intf,
+	(struct usb_descriptor_header *) &eem_fs_in_desc,
+	(struct usb_descriptor_header *) &eem_fs_out_desc,
+	NULL,
+};
+
+/* high speed support: */
+
+static struct usb_endpoint_descriptor eem_hs_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor eem_hs_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(512),
+};
+
+static struct usb_descriptor_header *eem_hs_function[] = {
+	/* CDC EEM control descriptors */
+	(struct usb_descriptor_header *) &eem_intf,
+	(struct usb_descriptor_header *) &eem_hs_in_desc,
+	(struct usb_descriptor_header *) &eem_hs_out_desc,
+	NULL,
+};
+
+/* super speed support: */
+
+static struct usb_endpoint_descriptor eem_ss_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+
+static struct usb_endpoint_descriptor eem_ss_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor eem_ss_bulk_comp_desc = {
+	.bLength =		sizeof eem_ss_bulk_comp_desc,
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+
+	/* the following 2 values can be tweaked if necessary */
+	/* .bMaxBurst =		0, */
+	/* .bmAttributes =	0, */
+};
+
+static struct usb_descriptor_header *eem_ss_function[] = {
+	/* CDC EEM control descriptors */
+	(struct usb_descriptor_header *) &eem_intf,
+	(struct usb_descriptor_header *) &eem_ss_in_desc,
+	(struct usb_descriptor_header *) &eem_ss_bulk_comp_desc,
+	(struct usb_descriptor_header *) &eem_ss_out_desc,
+	(struct usb_descriptor_header *) &eem_ss_bulk_comp_desc,
+	NULL,
+};
+
+/* string descriptors: */
+
+static struct usb_string eem_string_defs[] = {
+	[0].s = "CDC Ethernet Emulation Model (EEM)",
+	{  } /* end of list */
+};
+
+static struct usb_gadget_strings eem_string_table = {
+	.language =		0x0409,	/* en-us */
+	.strings =		eem_string_defs,
+};
+
+static struct usb_gadget_strings *eem_strings[] = {
+	&eem_string_table,
+	NULL,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int eem_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
+{
+	struct usb_composite_dev *cdev = f->config->cdev;
+	u16			w_index = le16_to_cpu(ctrl->wIndex);
+	u16			w_value = le16_to_cpu(ctrl->wValue);
+	u16			w_length = le16_to_cpu(ctrl->wLength);
+
+	DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
+		ctrl->bRequestType, ctrl->bRequest,
+		w_value, w_index, w_length);
+
+	/* device either stalls (value < 0) or reports success */
+	return -EOPNOTSUPP;
+}
+
+
+static int eem_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
+{
+	struct f_eem		*eem = func_to_eem(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+	struct net_device	*net;
+
+	/* we know alt == 0, so this is an activation or a reset */
+	if (alt != 0)
+		goto fail;
+
+	if (intf == eem->ctrl_id) {
+		DBG(cdev, "reset eem\n");
+		gether_disconnect(&eem->port);
+
+		if (!eem->port.in_ep->desc || !eem->port.out_ep->desc) {
+			DBG(cdev, "init eem\n");
+			if (config_ep_by_speed(cdev->gadget, f,
+					       eem->port.in_ep) ||
+			    config_ep_by_speed(cdev->gadget, f,
+					       eem->port.out_ep)) {
+				eem->port.in_ep->desc = NULL;
+				eem->port.out_ep->desc = NULL;
+				goto fail;
+			}
+		}
+
+		/* zlps should not occur because zero-length EEM packets
+		 * will be inserted in those cases where they would occur
+		 */
+		eem->port.is_zlp_ok = 1;
+		eem->port.cdc_filter = DEFAULT_FILTER;
+		DBG(cdev, "activate eem\n");
+		net = gether_connect(&eem->port);
+		if (IS_ERR(net))
+			return PTR_ERR(net);
+	} else
+		goto fail;
+
+	return 0;
+fail:
+	return -EINVAL;
+}
+
+static void eem_disable(struct usb_function *f)
+{
+	struct f_eem		*eem = func_to_eem(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+
+	DBG(cdev, "eem deactivated\n");
+
+	if (eem->port.in_ep->enabled)
+		gether_disconnect(&eem->port);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* EEM function driver setup/binding */
+
+static int eem_bind(struct usb_configuration *c, struct usb_function *f)
+{
+	struct usb_composite_dev *cdev = c->cdev;
+	struct f_eem		*eem = func_to_eem(f);
+	struct usb_string	*us;
+	int			status;
+	struct usb_ep		*ep;
+
+	struct f_eem_opts	*eem_opts;
+
+	eem_opts = container_of(f->fi, struct f_eem_opts, func_inst);
+	/*
+	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
+	 * configurations are bound in sequence with list_for_each_entry,
+	 * in each configuration its functions are bound in sequence
+	 * with list_for_each_entry, so we assume no race condition
+	 * with regard to eem_opts->bound access
+	 */
+	if (!eem_opts->bound) {
+		mutex_lock(&eem_opts->lock);
+		gether_set_gadget(eem_opts->net, cdev->gadget);
+		status = gether_register_netdev(eem_opts->net);
+		mutex_unlock(&eem_opts->lock);
+		if (status)
+			return status;
+		eem_opts->bound = true;
+	}
+
+	us = usb_gstrings_attach(cdev, eem_strings,
+				 ARRAY_SIZE(eem_string_defs));
+	if (IS_ERR(us))
+		return PTR_ERR(us);
+	eem_intf.iInterface = us[0].id;
+
+	/* allocate instance-specific interface IDs */
+	status = usb_interface_id(c, f);
+	if (status < 0)
+		goto fail;
+	eem->ctrl_id = status;
+	eem_intf.bInterfaceNumber = status;
+
+	status = -ENODEV;
+
+	/* allocate instance-specific endpoints */
+	ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_in_desc);
+	if (!ep)
+		goto fail;
+	eem->port.in_ep = ep;
+
+	ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_out_desc);
+	if (!ep)
+		goto fail;
+	eem->port.out_ep = ep;
+
+	/* support all relevant hardware speeds... we expect that when
+	 * hardware is dual speed, all bulk-capable endpoints work at
+	 * both speeds
+	 */
+	eem_hs_in_desc.bEndpointAddress = eem_fs_in_desc.bEndpointAddress;
+	eem_hs_out_desc.bEndpointAddress = eem_fs_out_desc.bEndpointAddress;
+
+	eem_ss_in_desc.bEndpointAddress = eem_fs_in_desc.bEndpointAddress;
+	eem_ss_out_desc.bEndpointAddress = eem_fs_out_desc.bEndpointAddress;
+
+	status = usb_assign_descriptors(f, eem_fs_function, eem_hs_function,
+			eem_ss_function, eem_ss_function);
+	if (status)
+		goto fail;
+
+	DBG(cdev, "CDC Ethernet (EEM): %s speed IN/%s OUT/%s\n",
+			gadget_is_superspeed(c->cdev->gadget) ? "super" :
+			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
+			eem->port.in_ep->name, eem->port.out_ep->name);
+	return 0;
+
+fail:
+	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
+
+	return status;
+}
+
+static void eem_cmd_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct in_context *ctx = req->context;
+
+	dev_kfree_skb_any(ctx->skb);
+	kfree(req->buf);
+	usb_ep_free_request(ctx->ep, req);
+	kfree(ctx);
+}
+
+/*
+ * Add the EEM header and ethernet checksum.
+ * We currently do not attempt to put multiple ethernet frames
+ * into a single USB transfer
+ */
+static struct sk_buff *eem_wrap(struct gether *port, struct sk_buff *skb)
+{
+	struct sk_buff	*skb2 = NULL;
+	struct usb_ep	*in = port->in_ep;
+	int		headroom, tailroom, padlen = 0;
+	u16		len;
+
+	if (!skb)
+		return NULL;
+
+	len = skb->len;
+	headroom = skb_headroom(skb);
+	tailroom = skb_tailroom(skb);
+
+	/* When (len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) is 0,
+	 * stick two bytes of zero-length EEM packet on the end.
+	 */
+	if (((len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) == 0)
+		padlen += 2;
+
+	if ((tailroom >= (ETH_FCS_LEN + padlen)) &&
+			(headroom >= EEM_HLEN) && !skb_cloned(skb))
+		goto done;
+
+	skb2 = skb_copy_expand(skb, EEM_HLEN, ETH_FCS_LEN + padlen, GFP_ATOMIC);
+	dev_kfree_skb_any(skb);
+	skb = skb2;
+	if (!skb)
+		return skb;
+
+done:
+	/* use the "no CRC" option */
+	put_unaligned_be32(0xdeadbeef, skb_put(skb, 4));
+
+	/* EEM packet header format:
+	 * b0..13:	length of ethernet frame
+	 * b14:		bmCRC (0 == sentinel CRC)
+	 * b15:		bmType (0 == data)
+	 */
+	len = skb->len;
+	put_unaligned_le16(len & 0x3FFF, skb_push(skb, 2));
+
+	/* add a zero-length EEM packet, if needed */
+	if (padlen)
+		put_unaligned_le16(0, skb_put(skb, 2));
+
+	return skb;
+}
+
+/*
+ * Remove the EEM header.  Note that there can be many EEM packets in a single
+ * USB transfer, so we need to break them out and handle them independently.
+ */
+static int eem_unwrap(struct gether *port,
+			struct sk_buff *skb,
+			struct sk_buff_head *list)
+{
+	struct usb_composite_dev	*cdev = port->func.config->cdev;
+	int				status = 0;
+
+	do {
+		struct sk_buff	*skb2;
+		u16		header;
+		u16		len = 0;
+
+		if (skb->len < EEM_HLEN) {
+			status = -EINVAL;
+			DBG(cdev, "invalid EEM header\n");
+			goto error;
+		}
+
+		/* remove the EEM header */
+		header = get_unaligned_le16(skb->data);
+		skb_pull(skb, EEM_HLEN);
+
+		/* EEM packet header format:
+		 * b0..14:	EEM type dependent (data or command)
+		 * b15:		bmType (0 == data, 1 == command)
+		 */
+		if (header & BIT(15)) {
+			struct usb_request	*req;
+			struct in_context	*ctx;
+			struct usb_ep		*ep;
+			u16			bmEEMCmd;
+
+			/* EEM command packet format:
+			 * b0..10:	bmEEMCmdParam
+			 * b11..13:	bmEEMCmd
+			 * b14:		reserved (must be zero)
+			 * b15:		bmType (1 == command)
+			 */
+			if (header & BIT(14))
+				continue;
+
+			bmEEMCmd = (header >> 11) & 0x7;
+			switch (bmEEMCmd) {
+			case 0: /* echo */
+				len = header & 0x7FF;
+				if (skb->len < len) {
+					status = -EOVERFLOW;
+					goto error;
+				}
+
+				skb2 = skb_clone(skb, GFP_ATOMIC);
+				if (unlikely(!skb2)) {
+					DBG(cdev, "EEM echo response error\n");
+					goto next;
+				}
+				skb_trim(skb2, len);
+				put_unaligned_le16(BIT(15) | BIT(11) | len,
+							skb_push(skb2, 2));
+
+				ep = port->in_ep;
+				req = usb_ep_alloc_request(ep, GFP_ATOMIC);
+				if (!req) {
+					dev_kfree_skb_any(skb2);
+					goto next;
+				}
+
+				req->buf = kmalloc(skb2->len, GFP_KERNEL);
+				if (!req->buf) {
+					usb_ep_free_request(ep, req);
+					dev_kfree_skb_any(skb2);
+					goto next;
+				}
+
+				ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
+				if (!ctx) {
+					kfree(req->buf);
+					usb_ep_free_request(ep, req);
+					dev_kfree_skb_any(skb2);
+					goto next;
+				}
+				ctx->skb = skb2;
+				ctx->ep = ep;
+
+				skb_copy_bits(skb2, 0, req->buf, skb2->len);
+				req->length = skb2->len;
+				req->complete = eem_cmd_complete;
+				req->zero = 1;
+				req->context = ctx;
+				if (usb_ep_queue(port->in_ep, req, GFP_ATOMIC))
+					DBG(cdev, "echo response queue fail\n");
+				break;
+
+			case 1:  /* echo response */
+			case 2:  /* suspend hint */
+			case 3:  /* response hint */
+			case 4:  /* response complete hint */
+			case 5:  /* tickle */
+			default: /* reserved */
+				continue;
+			}
+		} else {
+			u32		crc, crc2;
+			struct sk_buff	*skb3;
+
+			/* check for zero-length EEM packet */
+			if (header == 0)
+				continue;
+
+			/* EEM data packet format:
+			 * b0..13:	length of ethernet frame
+			 * b14:		bmCRC (0 == sentinel, 1 == calculated)
+			 * b15:		bmType (0 == data)
+			 */
+			len = header & 0x3FFF;
+			if ((skb->len < len)
+					|| (len < (ETH_HLEN + ETH_FCS_LEN))) {
+				status = -EINVAL;
+				goto error;
+			}
+
+			/* validate CRC */
+			if (header & BIT(14)) {
+				crc = get_unaligned_le32(skb->data + len
+							- ETH_FCS_LEN);
+				crc2 = ~crc32_le(~0,
+						skb->data, len - ETH_FCS_LEN);
+			} else {
+				crc = get_unaligned_be32(skb->data + len
+							- ETH_FCS_LEN);
+				crc2 = 0xdeadbeef;
+			}
+			if (crc != crc2) {
+				DBG(cdev, "invalid EEM CRC\n");
+				goto next;
+			}
+
+			skb2 = skb_clone(skb, GFP_ATOMIC);
+			if (unlikely(!skb2)) {
+				DBG(cdev, "unable to unframe EEM packet\n");
+				goto next;
+			}
+			skb_trim(skb2, len - ETH_FCS_LEN);
+
+			skb3 = skb_copy_expand(skb2,
+						NET_IP_ALIGN,
+						0,
+						GFP_ATOMIC);
+			if (unlikely(!skb3)) {
+				dev_kfree_skb_any(skb2);
+				goto next;
+			}
+			dev_kfree_skb_any(skb2);
+			skb_queue_tail(list, skb3);
+		}
+next:
+		skb_pull(skb, len);
+	} while (skb->len);
+
+error:
+	dev_kfree_skb_any(skb);
+	return status;
+}
+
+static inline struct f_eem_opts *to_f_eem_opts(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct f_eem_opts,
+			    func_inst.group);
+}
+
+/* f_eem_item_ops */
+USB_ETHERNET_CONFIGFS_ITEM(eem);
+
+/* f_eem_opts_dev_addr */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(eem);
+
+/* f_eem_opts_host_addr */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(eem);
+
+/* f_eem_opts_qmult */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(eem);
+
+/* f_eem_opts_ifname */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(eem);
+
+static struct configfs_attribute *eem_attrs[] = {
+	&eem_opts_attr_dev_addr,
+	&eem_opts_attr_host_addr,
+	&eem_opts_attr_qmult,
+	&eem_opts_attr_ifname,
+	NULL,
+};
+
+static const struct config_item_type eem_func_type = {
+	.ct_item_ops	= &eem_item_ops,
+	.ct_attrs	= eem_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+static void eem_free_inst(struct usb_function_instance *f)
+{
+	struct f_eem_opts *opts;
+
+	opts = container_of(f, struct f_eem_opts, func_inst);
+	if (opts->bound)
+		gether_cleanup(netdev_priv(opts->net));
+	else
+		free_netdev(opts->net);
+	kfree(opts);
+}
+
+static struct usb_function_instance *eem_alloc_inst(void)
+{
+	struct f_eem_opts *opts;
+
+	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+	if (!opts)
+		return ERR_PTR(-ENOMEM);
+	mutex_init(&opts->lock);
+	opts->func_inst.free_func_inst = eem_free_inst;
+	opts->net = gether_setup_default();
+	if (IS_ERR(opts->net)) {
+		struct net_device *net = opts->net;
+		kfree(opts);
+		return ERR_CAST(net);
+	}
+
+	config_group_init_type_name(&opts->func_inst.group, "", &eem_func_type);
+
+	return &opts->func_inst;
+}
+
+static void eem_free(struct usb_function *f)
+{
+	struct f_eem *eem;
+	struct f_eem_opts *opts;
+
+	eem = func_to_eem(f);
+	opts = container_of(f->fi, struct f_eem_opts, func_inst);
+	kfree(eem);
+	mutex_lock(&opts->lock);
+	opts->refcnt--;
+	mutex_unlock(&opts->lock);
+}
+
+static void eem_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+	DBG(c->cdev, "eem unbind\n");
+
+	usb_free_all_descriptors(f);
+}
+
+static struct usb_function *eem_alloc(struct usb_function_instance *fi)
+{
+	struct f_eem	*eem;
+	struct f_eem_opts *opts;
+
+	/* allocate and initialize one new instance */
+	eem = kzalloc(sizeof(*eem), GFP_KERNEL);
+	if (!eem)
+		return ERR_PTR(-ENOMEM);
+
+	opts = container_of(fi, struct f_eem_opts, func_inst);
+	mutex_lock(&opts->lock);
+	opts->refcnt++;
+
+	eem->port.ioport = netdev_priv(opts->net);
+	mutex_unlock(&opts->lock);
+	eem->port.cdc_filter = DEFAULT_FILTER;
+
+	eem->port.func.name = "cdc_eem";
+	/* descriptors are per-instance copies */
+	eem->port.func.bind = eem_bind;
+	eem->port.func.unbind = eem_unbind;
+	eem->port.func.set_alt = eem_set_alt;
+	eem->port.func.setup = eem_setup;
+	eem->port.func.disable = eem_disable;
+	eem->port.func.free_func = eem_free;
+	eem->port.wrap = eem_wrap;
+	eem->port.unwrap = eem_unwrap;
+	eem->port.header_len = EEM_HLEN;
+
+	return &eem->port.func;
+}
+
+DECLARE_USB_FUNCTION_INIT(eem, eem_alloc_inst, eem_alloc);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Brownell");