--- /dev/null
+/*
+ * 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
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#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;
+};
+
+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;
+ int value = -EOPNOTSUPP;
+ 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 value;
+}
+
+
+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) {
+
+ if (eem->port.in_ep->driver_data) {
+ 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->driver_data)
+ 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->driver_data = cdev; /* claim */
+
+ ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_out_desc);
+ if (!ep)
+ goto fail;
+ eem->port.out_ep = ep;
+ ep->driver_data = cdev; /* claim */
+
+ status = -ENOMEM;
+
+ /* 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);
+ 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:
+ if (eem->port.out_ep)
+ eem->port.out_ep->driver_data = NULL;
+ if (eem->port.in_ep)
+ eem->port.in_ep->driver_data = NULL;
+
+ 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 sk_buff *skb = (struct sk_buff *)req->context;
+
+ dev_kfree_skb_any(skb);
+}
+
+/*
+ * 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 padlen = 0;
+ u16 len = skb->len;
+
+ int headroom = skb_headroom(skb);
+ int 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 = cdev->req;
+ 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));
+ skb_copy_bits(skb2, 0, req->buf, skb2->len);
+ req->length = skb2->len;
+ req->complete = eem_cmd_complete;
+ req->zero = 1;
+ req->context = skb2;
+ 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");
+ continue;
+ }
+ skb_trim(skb2, len - ETH_FCS_LEN);
+
+ skb3 = skb_copy_expand(skb2,
+ NET_IP_ALIGN,
+ 0,
+ GFP_ATOMIC);
+ if (unlikely(!skb3)) {
+ DBG(cdev, "unable to realign EEM packet\n");
+ dev_kfree_skb_any(skb2);
+ continue;
+ }
+ 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[] = {
+ &f_eem_opts_dev_addr.attr,
+ &f_eem_opts_host_addr.attr,
+ &f_eem_opts_qmult.attr,
+ &f_eem_opts_ifname.attr,
+ NULL,
+};
+
+static 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");
Code Review / kvmfornfv.git / blobdiff