// 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/cleanup.h>#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; struct net_device *net __free(detach_gadget) = NULL; eem_opts = container_of(f->fi, struct f_eem_opts, func_inst); scoped_guard(mutex, &eem_opts->lock) if (eem_opts->bind_count == 0 && !eem_opts->bound) { if (!device_is_registered(&eem_opts->net->dev)) { gether_set_gadget(eem_opts->net, cdev->gadget); status = gether_register_netdev(eem_opts->net); } else status = gether_attach_gadget(eem_opts->net, cdev->gadget); if (status) return status; net = eem_opts->net; } 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) return status; eem->ctrl_id = status; eem_intf.bInterfaceNumber = status; /* allocate instance-specific endpoints */ ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_in_desc); if (!ep) return -ENODEV; eem->port.in_ep = ep; ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_out_desc); if (!ep) return -ENODEV; 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) return status; eem_opts->bind_count++; retain_and_null_ptr(net); DBG(cdev, "CDC Ethernet (EEM): IN/%s OUT/%s\n", eem->port.in_ep->name, eem->port.out_ep->name); return 0;} 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_obj(*ctx); 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"); kfree(ctx); kfree(req->buf); usb_ep_free_request(ep, req); dev_kfree_skb_any(skb2); } 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:Lines 1–500 of 687. 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// 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/cleanup.h> #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; struct net_device *net __free(detach_gadget) = NULL; eem_opts = container_of(f->fi, struct f_eem_opts, func_inst); scoped_guard(mutex, &eem_opts->lock) if (eem_opts->bind_count == 0 && !eem_opts->bound) { if (!device_is_registered(&eem_opts->net->dev)) { gether_set_gadget(eem_opts->net, cdev->gadget); status = gether_register_netdev(eem_opts->net); } else status = gether_attach_gadget(eem_opts->net, cdev->gadget); if (status) return status; net = eem_opts->net; } 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) return status; eem->ctrl_id = status; eem_intf.bInterfaceNumber = status; /* allocate instance-specific endpoints */ ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_in_desc); if (!ep) return -ENODEV; eem->port.in_ep = ep; ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_out_desc); if (!ep) return -ENODEV; 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) return status; eem_opts->bind_count++; retain_and_null_ptr(net); DBG(cdev, "CDC Ethernet (EEM): IN/%s OUT/%s\n", eem->port.in_ep->name, eem->port.out_ep->name); return 0; } 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_obj(*ctx); 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"); kfree(ctx); kfree(req->buf); usb_ep_free_request(ep, req); dev_kfree_skb_any(skb2); } 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: