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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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#include <linux/hid.h>#include <linux/hidraw.h>#include <linux/hw_random.h>#include <linux/leds.h>#include <linux/module.h>#include <linux/mutex.h>#include <linux/usb.h>
#include "usbhid/usbhid.h"#include "hid-ids.h"
#define DRIVER_SHORT "u2fzero"
#define HID_REPORT_SIZE 64
enum hw_revision { HW_U2FZERO, HW_NITROKEY_U2F,};
struct hw_revision_config { u8 rng_cmd; u8 wink_cmd; const char *name;};
static const struct hw_revision_config hw_configs[] = { [HW_U2FZERO] = { .rng_cmd = 0x21, .wink_cmd = 0x24, .name = "U2F Zero", }, [HW_NITROKEY_U2F] = { .rng_cmd = 0xc0, .wink_cmd = 0xc2, .name = "NitroKey U2F", },};
/* We only use broadcast (CID-less) messages */#define CID_BROADCAST 0xffffffff
struct u2f_hid_msg { u32 cid; union { struct { u8 cmd; u8 bcnth; u8 bcntl; u8 data[HID_REPORT_SIZE - 7]; } init; struct { u8 seq; u8 data[HID_REPORT_SIZE - 5]; } cont; };} __packed;
struct u2f_hid_report { u8 report_type; struct u2f_hid_msg msg;} __packed;
#define U2F_HID_MSG_LEN(f) (size_t)(((f).init.bcnth << 8) + (f).init.bcntl)
struct u2fzero_device { struct hid_device *hdev; struct urb *urb; /* URB for the RNG data */ struct led_classdev ldev; /* Embedded struct for led */ struct hwrng hwrng; /* Embedded struct for hwrng */ char *led_name; char *rng_name; u8 *buf_out; u8 *buf_in; struct mutex lock; bool present; kernel_ulong_t hw_revision;};
static int u2fzero_send(struct u2fzero_device *dev, struct u2f_hid_report *req){ int ret;
mutex_lock(&dev->lock);
memcpy(dev->buf_out, req, sizeof(struct u2f_hid_report));
ret = hid_hw_output_report(dev->hdev, dev->buf_out, sizeof(struct u2f_hid_msg));
mutex_unlock(&dev->lock);
if (ret < 0) return ret;
return ret == sizeof(struct u2f_hid_msg) ? 0 : -EMSGSIZE;}
struct u2fzero_transfer_context { struct completion done; int status;};
static void u2fzero_read_callback(struct urb *urb){ struct u2fzero_transfer_context *ctx = urb->context;
ctx->status = urb->status; complete(&ctx->done);}
static int u2fzero_recv(struct u2fzero_device *dev, struct u2f_hid_report *req, struct u2f_hid_msg *resp){ int ret; struct hid_device *hdev = dev->hdev; struct u2fzero_transfer_context ctx;
mutex_lock(&dev->lock);
memcpy(dev->buf_out, req, sizeof(struct u2f_hid_report));
dev->urb->context = &ctx; init_completion(&ctx.done);
ret = usb_submit_urb(dev->urb, GFP_NOIO); if (unlikely(ret)) { hid_err(hdev, "usb_submit_urb failed: %d", ret); goto err; }
ret = hid_hw_output_report(dev->hdev, dev->buf_out, sizeof(struct u2f_hid_msg));
if (ret < 0) { hid_err(hdev, "hid_hw_output_report failed: %d", ret); goto err; }
ret = (wait_for_completion_timeout( &ctx.done, msecs_to_jiffies(USB_CTRL_SET_TIMEOUT))); if (ret == 0) { usb_kill_urb(dev->urb); hid_err(hdev, "urb submission timed out"); } else { ret = dev->urb->actual_length; memcpy(resp, dev->buf_in, ret); }
err: mutex_unlock(&dev->lock);
return ret;}
static int u2fzero_blink(struct led_classdev *ldev){ struct u2fzero_device *dev = container_of(ldev, struct u2fzero_device, ldev); struct u2f_hid_report req = { .report_type = 0, .msg.cid = CID_BROADCAST, .msg.init = { .cmd = hw_configs[dev->hw_revision].wink_cmd, .bcnth = 0, .bcntl = 0, .data = {0}, } }; return u2fzero_send(dev, &req);}
static int u2fzero_brightness_set(struct led_classdev *ldev, enum led_brightness brightness){ ldev->brightness = LED_OFF; if (brightness) return u2fzero_blink(ldev); else return 0;}
static int u2fzero_rng_read(struct hwrng *rng, void *data, size_t max, bool wait){ struct u2fzero_device *dev = container_of(rng, struct u2fzero_device, hwrng); struct u2f_hid_report req = { .report_type = 0, .msg.cid = CID_BROADCAST, .msg.init = { .cmd = hw_configs[dev->hw_revision].rng_cmd, .bcnth = 0, .bcntl = 0, .data = {0}, } }; struct u2f_hid_msg resp; int ret; size_t actual_length; /* valid packets must have a correct header */ int min_length = offsetof(struct u2f_hid_msg, init.data);
if (!dev->present) { hid_dbg(dev->hdev, "device not present"); return 0; }
ret = u2fzero_recv(dev, &req, &resp);
/* ignore errors or packets without data */ if (ret < min_length) return 0;
/* only take the minimum amount of data it is safe to take */ actual_length = min3((size_t)ret - min_length, U2F_HID_MSG_LEN(resp), max);
memcpy(data, resp.init.data, actual_length);
return actual_length;}
static int u2fzero_init_led(struct u2fzero_device *dev, unsigned int minor){ dev->led_name = devm_kasprintf(&dev->hdev->dev, GFP_KERNEL, "%s%u", DRIVER_SHORT, minor); if (dev->led_name == NULL) return -ENOMEM;
dev->ldev.name = dev->led_name; dev->ldev.max_brightness = LED_ON; dev->ldev.flags = LED_HW_PLUGGABLE; dev->ldev.brightness_set_blocking = u2fzero_brightness_set;
return devm_led_classdev_register(&dev->hdev->dev, &dev->ldev);}
static int u2fzero_init_hwrng(struct u2fzero_device *dev, unsigned int minor){ dev->rng_name = devm_kasprintf(&dev->hdev->dev, GFP_KERNEL, "%s-rng%u", DRIVER_SHORT, minor); if (dev->rng_name == NULL) return -ENOMEM;
dev->hwrng.name = dev->rng_name; dev->hwrng.read = u2fzero_rng_read;
return devm_hwrng_register(&dev->hdev->dev, &dev->hwrng);}
static int u2fzero_fill_in_urb(struct u2fzero_device *dev){ struct hid_device *hdev = dev->hdev; struct usb_device *udev; struct usbhid_device *usbhid = hdev->driver_data; unsigned int pipe_in; struct usb_host_endpoint *ep;
if (dev->hdev->bus != BUS_USB) return -EINVAL;
udev = hid_to_usb_dev(hdev);
if (!usbhid->urbout || !usbhid->urbin) return -ENODEV;
ep = usb_pipe_endpoint(udev, usbhid->urbin->pipe); if (!ep) return -ENODEV;
dev->urb = usb_alloc_urb(0, GFP_KERNEL); if (!dev->urb) return -ENOMEM;
pipe_in = (usbhid->urbin->pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30);
usb_fill_int_urb(dev->urb, udev, pipe_in, dev->buf_in, HID_REPORT_SIZE, u2fzero_read_callback, NULL, ep->desc.bInterval);
return 0;}
static int u2fzero_probe(struct hid_device *hdev, const struct hid_device_id *id){ struct u2fzero_device *dev; unsigned int minor; int ret;
if (!hid_is_usb(hdev)) return -EINVAL;
dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL); if (dev == NULL) return -ENOMEM;
dev->hw_revision = id->driver_data;
dev->buf_out = devm_kmalloc(&hdev->dev, sizeof(struct u2f_hid_report), GFP_KERNEL); if (dev->buf_out == NULL) return -ENOMEM;
dev->buf_in = devm_kmalloc(&hdev->dev, sizeof(struct u2f_hid_msg), GFP_KERNEL); if (dev->buf_in == NULL) return -ENOMEM;
ret = hid_parse(hdev); if (ret) return ret;
dev->hdev = hdev; hid_set_drvdata(hdev, dev); mutex_init(&dev->lock);
ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW); if (ret) return ret;
ret = u2fzero_fill_in_urb(dev); if (ret) goto err_hid_hw_stop;
dev->present = true;
minor = ((struct hidraw *) hdev->hidraw)->minor;
ret = u2fzero_init_led(dev, minor); if (ret) goto err_free_urb;
hid_info(hdev, "%s LED initialised\n", hw_configs[dev->hw_revision].name);
ret = u2fzero_init_hwrng(dev, minor); if (ret) goto err_free_urb;
hid_info(hdev, "%s RNG initialised\n", hw_configs[dev->hw_revision].name);
return 0;
err_free_urb: usb_free_urb(dev->urb);err_hid_hw_stop: hid_hw_stop(hdev); return ret;}
static void u2fzero_remove(struct hid_device *hdev){ struct u2fzero_device *dev = hid_get_drvdata(hdev);
mutex_lock(&dev->lock); dev->present = false; mutex_unlock(&dev->lock);
hid_hw_stop(hdev); usb_poison_urb(dev->urb); usb_free_urb(dev->urb);}
static const struct hid_device_id u2fzero_table[] = { { HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_U2F_ZERO), .driver_data = HW_U2FZERO }, { HID_USB_DEVICE(USB_VENDOR_ID_CLAY_LOGIC, USB_DEVICE_ID_NITROKEY_U2F), .driver_data = HW_NITROKEY_U2F }, { }};MODULE_DEVICE_TABLE(hid, u2fzero_table);
static struct hid_driver u2fzero_driver = { .name = "hid-" DRIVER_SHORT, .probe = u2fzero_probe, .remove = u2fzero_remove, .id_table = u2fzero_table,};
module_hid_driver(u2fzero_driver);
MODULE_LICENSE("GPL");MODULE_AUTHOR("Andrej Shadura <andrew@shadura.me>");MODULE_DESCRIPTION("U2F Zero LED and RNG driver");