Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Andrew Shadura | 1730 | 99.31% | 5 | 71.43% |
Jiri Kosina | 11 | 0.63% | 1 | 14.29% |
Greg Kroah-Hartman | 1 | 0.06% | 1 | 14.29% |
Total | 1742 | 7 |
// SPDX-License-Identifier: GPL-2.0 /* * U2F Zero LED and RNG driver * * Copyright 2018 Andrej Shadura <andrew@shadura.me> * Loosely based on drivers/hid/hid-led.c * and drivers/usb/misc/chaoskey.c * * 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, version 2. */ #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; dev->hwrng.quality = 1; 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; u2fzero_fill_in_urb(dev); dev->present = true; minor = ((struct hidraw *) hdev->hidraw)->minor; ret = u2fzero_init_led(dev, minor); if (ret) { hid_hw_stop(hdev); return ret; } hid_info(hdev, "%s LED initialised\n", hw_configs[dev->hw_revision].name); ret = u2fzero_init_hwrng(dev, minor); if (ret) { hid_hw_stop(hdev); return ret; } hid_info(hdev, "%s RNG initialised\n", hw_configs[dev->hw_revision].name); return 0; } 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");
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