/* * 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/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 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 __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, }; /* super speed support: */ static struct usb_endpoint_descriptor eem_ss_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(1024), }; static struct usb_endpoint_descriptor eem_ss_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(1024), }; static struct usb_ss_ep_comp_descriptor eem_ss_bulk_comp_desc __initdata = { .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[] __initdata = { /* 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 __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; /* 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; } if (gadget_is_superspeed(c->cdev->gadget)) { eem_ss_in_desc.bEndpointAddress = eem_fs_in_desc.bEndpointAddress; eem_ss_out_desc.bEndpointAddress = eem_fs_out_desc.bEndpointAddress; /* copy descriptors, and track endpoint copies */ f->ss_descriptors = usb_copy_descriptors(eem_ss_function); if (!f->ss_descriptors) 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 (f->descriptors) usb_free_descriptors(f->descriptors); if (f->hs_descriptors) usb_free_descriptors(f->hs_descriptors); /* we might as well release our claims on endpoints */ if (eem->port.out_ep->desc) eem->port.out_ep->driver_data = NULL; if (eem->port.in_ep->desc) 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_superspeed(c->cdev->gadget)) usb_free_descriptors(f->ss_descriptors); 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; }