| /* |
| * 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. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/device.h> |
| #include <linux/etherdevice.h> |
| #include <linux/crc32.h> |
| #include <linux/slab.h> |
| |
| #include "u_ether.h" |
| |
| #define EEM_HLEN 2 |
| |
| /* |
| * This function is a "CDC Ethernet Emulation Model" (CDC EEM) |
| * Ethernet link. |
| */ |
| |
| struct eem_ep_descs { |
| struct usb_endpoint_descriptor *in; |
| struct usb_endpoint_descriptor *out; |
| }; |
| |
| struct f_eem { |
| struct gether port; |
| u8 ctrl_id; |
| |
| struct eem_ep_descs fs; |
| struct eem_ep_descs hs; |
| }; |
| |
| 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 __initdata = { |
| .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 __initdata = { |
| .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 __initdata = { |
| .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[] __initdata = { |
| /* 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 __initdata = { |
| .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 __initdata = { |
| .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[] __initdata = { |
| /* 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, |
| }; |
| |
| /* 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) { |
| DBG(cdev, "init eem\n"); |
| eem->port.in = ep_choose(cdev->gadget, |
| eem->hs.in, eem->fs.in); |
| eem->port.out = ep_choose(cdev->gadget, |
| eem->hs.out, eem->fs.out); |
| } |
| |
| /* 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 __init |
| 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); |
| int status; |
| struct usb_ep *ep; |
| |
| /* 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; |
| |
| /* copy descriptors, and track endpoint copies */ |
| f->descriptors = usb_copy_descriptors(eem_fs_function); |
| if (!f->descriptors) |
| goto fail; |
| |
| eem->fs.in = usb_find_endpoint(eem_fs_function, |
| f->descriptors, &eem_fs_in_desc); |
| eem->fs.out = usb_find_endpoint(eem_fs_function, |
| f->descriptors, &eem_fs_out_desc); |
| |
| /* support all relevant hardware speeds... we expect that when |
| * hardware is dual speed, all bulk-capable endpoints work at |
| * both speeds |
| */ |
| if (gadget_is_dualspeed(c->cdev->gadget)) { |
| eem_hs_in_desc.bEndpointAddress = |
| eem_fs_in_desc.bEndpointAddress; |
| eem_hs_out_desc.bEndpointAddress = |
| eem_fs_out_desc.bEndpointAddress; |
| |
| /* copy descriptors, and track endpoint copies */ |
| f->hs_descriptors = usb_copy_descriptors(eem_hs_function); |
| if (!f->hs_descriptors) |
| goto fail; |
| |
| eem->hs.in = usb_find_endpoint(eem_hs_function, |
| f->hs_descriptors, &eem_hs_in_desc); |
| eem->hs.out = usb_find_endpoint(eem_hs_function, |
| f->hs_descriptors, &eem_hs_out_desc); |
| } |
| |
| DBG(cdev, "CDC Ethernet (EEM): %s speed IN/%s OUT/%s\n", |
| gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full", |
| eem->port.in_ep->name, eem->port.out_ep->name); |
| return 0; |
| |
| fail: |
| if (f->descriptors) |
| usb_free_descriptors(f->descriptors); |
| |
| /* we might as well release our claims on endpoints */ |
| if (eem->port.out) |
| eem->port.out_ep->driver_data = NULL; |
| if (eem->port.in) |
| eem->port.in_ep->driver_data = NULL; |
| |
| ERROR(cdev, "%s: can't bind, err %d\n", f->name, status); |
| |
| return status; |
| } |
| |
| static void |
| eem_unbind(struct usb_configuration *c, struct usb_function *f) |
| { |
| struct f_eem *eem = func_to_eem(f); |
| |
| DBG(c->cdev, "eem unbind\n"); |
| |
| if (gadget_is_dualspeed(c->cdev->gadget)) |
| usb_free_descriptors(f->hs_descriptors); |
| usb_free_descriptors(f->descriptors); |
| kfree(eem); |
| } |
| |
| 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; |
| |
| if (!skb_cloned(skb)) { |
| 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)) |
| 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; |
| } |
| |
| /** |
| * eem_bind_config - add CDC Ethernet (EEM) network link to a configuration |
| * @c: the configuration to support the network link |
| * Context: single threaded during gadget setup |
| * |
| * Returns zero on success, else negative errno. |
| * |
| * Caller must have called @gether_setup(). Caller is also responsible |
| * for calling @gether_cleanup() before module unload. |
| */ |
| int __init eem_bind_config(struct usb_configuration *c) |
| { |
| struct f_eem *eem; |
| int status; |
| |
| /* maybe allocate device-global string IDs */ |
| if (eem_string_defs[0].id == 0) { |
| |
| /* control interface label */ |
| status = usb_string_id(c->cdev); |
| if (status < 0) |
| return status; |
| eem_string_defs[0].id = status; |
| eem_intf.iInterface = status; |
| } |
| |
| /* allocate and initialize one new instance */ |
| eem = kzalloc(sizeof *eem, GFP_KERNEL); |
| if (!eem) |
| return -ENOMEM; |
| |
| eem->port.cdc_filter = DEFAULT_FILTER; |
| |
| eem->port.func.name = "cdc_eem"; |
| eem->port.func.strings = eem_strings; |
| /* 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.wrap = eem_wrap; |
| eem->port.unwrap = eem_unwrap; |
| eem->port.header_len = EEM_HLEN; |
| |
| status = usb_add_function(c, &eem->port.func); |
| if (status) |
| kfree(eem); |
| return status; |
| } |
| |