diff options
| -rw-r--r-- | drivers/hid/Kconfig | 15 | ||||
| -rw-r--r-- | drivers/hid/Makefile | 1 | ||||
| -rw-r--r-- | drivers/hid/hid-ids.h | 1 | ||||
| -rw-r--r-- | drivers/hid/hid-u2fzero.c | 371 |
4 files changed, 388 insertions, 0 deletions
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig index 4ca0cdfa6b33..b090d425ff22 100644 --- a/drivers/hid/Kconfig +++ b/drivers/hid/Kconfig @@ -1003,6 +1003,21 @@ config HID_UDRAW_PS3 Say Y here if you want to use the THQ uDraw gaming tablet for the PS3. +config HID_U2FZERO + tristate "U2F Zero LED and RNG support" + depends on USB_HID + depends on LEDS_CLASS + help + Support for the LED of the U2F Zero device. + + U2F Zero supports custom commands for blinking the LED + and getting data from the internal hardware RNG. + The internal hardware can be used to feed the enthropy pool. + + U2F Zero only supports blinking its LED, so this driver doesn't + allow setting the brightness to anything but 1, which will + trigger a single blink and immediately reset to back 0. + config HID_WACOM tristate "Wacom Intuos/Graphire tablet support (USB)" depends on USB_HID diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile index 170163b41303..338d93f0c139 100644 --- a/drivers/hid/Makefile +++ b/drivers/hid/Makefile @@ -109,6 +109,7 @@ obj-$(CONFIG_HID_THRUSTMASTER) += hid-tmff.o obj-$(CONFIG_HID_TIVO) += hid-tivo.o obj-$(CONFIG_HID_TOPSEED) += hid-topseed.o obj-$(CONFIG_HID_TWINHAN) += hid-twinhan.o +obj-$(CONFIG_HID_U2FZERO) += hid-u2fzero.o hid-uclogic-objs := hid-uclogic-core.o \ hid-uclogic-rdesc.o \ hid-uclogic-params.o diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h index adce58f24f76..03d86cace074 100644 --- a/drivers/hid/hid-ids.h +++ b/drivers/hid/hid-ids.h @@ -323,6 +323,7 @@ #define USB_DEVICE_ID_CYGNAL_RADIO_SI470X 0x818a #define USB_DEVICE_ID_FOCALTECH_FTXXXX_MULTITOUCH 0x81b9 #define USB_DEVICE_ID_CYGNAL_CP2112 0xea90 +#define USB_DEVICE_ID_U2F_ZERO 0x8acf #define USB_DEVICE_ID_CYGNAL_RADIO_SI4713 0x8244 diff --git a/drivers/hid/hid-u2fzero.c b/drivers/hid/hid-u2fzero.c new file mode 100644 index 000000000000..d11a5cb56a0d --- /dev/null +++ b/drivers/hid/hid-u2fzero.c @@ -0,0 +1,371 @@ +// 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 + +/* 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) + +/* Custom extensions to the U2FHID protocol */ +#define U2F_CUSTOM_GET_RNG 0x21 +#define U2F_CUSTOM_WINK 0x24 + +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; +}; + +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 = U2F_CUSTOM_WINK, + .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 = U2F_CUSTOM_GET_RNG, + .bcnth = 0, + .bcntl = 0, + .data = {0}, + } + }; + struct u2f_hid_msg resp; + int ret; + size_t actual_length; + + if (!dev->present) { + hid_dbg(dev->hdev, "device not present"); + return 0; + } + + ret = u2fzero_recv(dev, &req, &resp); + if (ret < 0) + return 0; + + /* only take the minimum amount of data it is safe to take */ + actual_length = min3((size_t)ret - offsetof(struct u2f_hid_msg, + init.data), 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; + + dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL); + if (dev == NULL) + return -ENOMEM; + + 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, "U2F Zero LED initialised\n"); + + ret = u2fzero_init_hwrng(dev, minor); + if (ret) { + hid_hw_stop(hdev); + return ret; + } + + hid_info(hdev, "U2F Zero RNG initialised\n"); + + 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) }, + { } +}; +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"); |