1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482
// ************************************************************************** // Copyright (c) 2015 Osspial All Rights Reserved. // // This file is part of hidapi-rs, based on hidapi_rust by Roland Ruckerbauer. // ************************************************************************* //! This crate provides a rust abstraction over the features of the C library //! hidapi by [signal11](https://github.com/signal11/hidapi). //! //! # Usage //! //! This crate is [on crates.io](https://crates.io/crates/hidapi) and can be //! used by adding `hidapi` to the dependencies in your project's `Cargo.toml`. //! //! # Example //! //! ```rust,no_run //! extern crate hidapi; //! //! use hidapi::HidApi; //! //! fn main() { //! println!("Printing all available hid devices:"); //! //! match HidApi::new() { //! Ok(api) => { //! for device in api.devices() { //! println!("{:#?}", device); //! } //! }, //! Err(e) => { //! eprintln!("Error: {}", e); //! }, //! } //! } //! ``` extern crate libc; mod error; mod ffi; use libc::{c_int, size_t, wchar_t}; use std::ffi::CStr; use std::ffi::CString; use std::mem::ManuallyDrop; use std::rc::Rc; use std::sync::atomic::{AtomicBool, Ordering}; pub use error::HidError; pub type HidResult<T> = Result<T, HidError>; const STRING_BUF_LEN: usize = 128; /// Hidapi context and device member, which ensures deinitialization /// of the C library happens, when, and only when all devices and the api instance is dropped. struct HidApiLock; impl HidApiLock { fn acquire() -> HidResult<HidApiLock> { const EXPECTED_CURRENT: bool = false; if EXPECTED_CURRENT == HID_API_LOCK.compare_and_swap(EXPECTED_CURRENT, true, Ordering::SeqCst) { // Initialize the HID and prevent other HIDs from being created unsafe { if ffi::hid_init() == -1 { HID_API_LOCK.store(false, Ordering::SeqCst); return Err(HidError::InitializationError); } Ok(HidApiLock) } } else { Err(HidError::InitializationError) } } } impl Drop for HidApiLock { fn drop(&mut self) { unsafe { ffi::hid_exit(); } HID_API_LOCK.store(false, Ordering::SeqCst); } } /// Object for handling hidapi context and implementing RAII for it. /// Only one instance can exist at a time. pub struct HidApi { devices: Vec<HidDeviceInfo>, _lock: Rc<HidApiLock>, } static HID_API_LOCK: AtomicBool = AtomicBool::new(false); impl HidApi { /// Initializes the hidapi. /// /// Will also initialize the currently available device list. pub fn new() -> HidResult<Self> { let lock = HidApiLock::acquire()?; Ok(HidApi { devices: unsafe { HidApi::get_hid_device_info_vector()? }, _lock: Rc::new(lock), }) } /// Refresh devices list and information about them (to access them use /// `devices()` method) pub fn refresh_devices(&mut self) -> HidResult<()> { self.devices = unsafe { HidApi::get_hid_device_info_vector()? }; Ok(()) } unsafe fn get_hid_device_info_vector() -> HidResult<Vec<HidDeviceInfo>> { let mut device_vector = Vec::with_capacity(8); let enumeration = ffi::hid_enumerate(0, 0); { let mut current_device = enumeration; while !current_device.is_null() { device_vector.push(conv_hid_device_info(current_device)?); current_device = (*current_device).next; } } if !enumeration.is_null() { ffi::hid_free_enumeration(enumeration); } Ok(device_vector) } /// Returns list of objects containing information about connected devices pub fn devices(&self) -> &Vec<HidDeviceInfo> { &self.devices } /// Open a HID device using a Vendor ID (VID) and Product ID (PID). /// /// When multiple devices with the same vid and pid are available, then the /// first one found in the internal device list will be used. There are however /// no grantees, which device this will be. pub fn open(&self, vid: u16, pid: u16) -> HidResult<HidDevice> { let device = unsafe { ffi::hid_open(vid, pid, std::ptr::null()) }; if device.is_null() { Err(HidError::OpenHidDeviceError) } else { Ok(HidDevice { _hid_device: device, _lock: ManuallyDrop::new(self._lock.clone()), }) } } /// Open a HID device using a Vendor ID (VID), Product ID (PID) and /// a serial number. pub fn open_serial(&self, vid: u16, pid: u16, sn: &str) -> HidResult<HidDevice> { let mut chars = sn.chars().map(|c| c as wchar_t).collect::<Vec<_>>(); chars.push(0 as wchar_t); let device = unsafe { ffi::hid_open(vid, pid, chars.as_ptr()) }; if device.is_null() { Err(HidError::OpenHidDeviceError) } else { Ok(HidDevice { _hid_device: device, _lock: ManuallyDrop::new(self._lock.clone()), }) } } /// The path name be determined by inspecting the device list available with [HidApi::devices()](struct.HidApi.html#method.devices) /// /// Alternatively a platform-specific path name can be used (eg: /dev/hidraw0 on Linux). pub fn open_path(&self, device_path: &CStr) -> HidResult<HidDevice> { let device = unsafe { ffi::hid_open_path(device_path.as_ptr()) }; if device.is_null() { Err(HidError::OpenHidDeviceError) } else { Ok(HidDevice { _hid_device: device, _lock: ManuallyDrop::new(self._lock.clone()), }) } } } /// Converts a pointer to a `wchar_t` to a optional string unsafe fn wchar_to_string(wstr: *const wchar_t) -> HidResult<Option<String>> { if wstr.is_null() { return Ok(None); } let mut char_vector: Vec<char> = Vec::with_capacity(8); let mut index: isize = 0; let o = |i| *wstr.offset(i); while o(index) != 0 { use std::char; char_vector.push(match char::from_u32(o(index) as u32) { Some(ch) => ch, None => Err(HidError::FromWideCharError { wide_char: o(index), })?, }); index += 1; } Ok(Some(char_vector.into_iter().collect())) } /// Convert the CFFI `HidDeviceInfo` struct to a native `HidDeviceInfo` struct unsafe fn conv_hid_device_info(src: *mut ffi::HidDeviceInfo) -> HidResult<HidDeviceInfo> { Ok(HidDeviceInfo { path: CStr::from_ptr((*src).path).to_owned(), vendor_id: (*src).vendor_id, product_id: (*src).product_id, serial_number: wchar_to_string((*src).serial_number)?, release_number: (*src).release_number, manufacturer_string: wchar_to_string((*src).manufacturer_string)?, product_string: wchar_to_string((*src).product_string)?, usage_page: (*src).usage_page, usage: (*src).usage, interface_number: (*src).interface_number, }) } #[derive(Debug, Clone)] /// Storage for device related information pub struct HidDeviceInfo { pub path: CString, pub vendor_id: u16, pub product_id: u16, pub serial_number: Option<String>, pub release_number: u16, pub manufacturer_string: Option<String>, pub product_string: Option<String>, pub usage_page: u16, pub usage: u16, pub interface_number: i32, } impl HidDeviceInfo { /// Use the information contained in `HidDeviceInfo` to open /// and return a handle to a [HidDevice](struct.HidDevice.html). /// /// By default the device path is used to open the device. /// When no path is available, then vid, pid and serial number are used. /// If both path and serial number are not available, then this function will /// fail with [HidError::OpenHidDeviceWithDeviceInfoError](enum.HidError.html#variant.OpenHidDeviceWithDeviceInfoError). /// /// Note, that opening a device could still be done using [HidApi::open()](struct.HidApi.html#method.open) directly. pub fn open_device(&self, hidapi: &HidApi) -> HidResult<HidDevice> { if self.path.as_bytes().len() != 0 { hidapi.open_path(self.path.as_c_str()) } else if let Some(ref sn) = self.serial_number { hidapi.open_serial(self.vendor_id, self.product_id, sn) } else { Err(HidError::OpenHidDeviceWithDeviceInfoError { device_info: self.clone(), }) } } } /// Object for accessing HID device pub struct HidDevice { _hid_device: *mut ffi::HidDevice, /// Prevents this from outliving the api instance that created it _lock: ManuallyDrop<Rc<HidApiLock>>, } impl Drop for HidDevice { fn drop(&mut self) { unsafe { ffi::hid_close(self._hid_device); ManuallyDrop::drop(&mut self._lock); }; } } impl HidDevice { /// Check size returned by other methods, if it's equal to -1 check for /// error and return Error, otherwise return size as unsigned number fn check_size(&self, res: i32) -> HidResult<usize> { if res == -1 { match self.check_error() { Ok(err) => Err(err), Err(e) => Err(e), } } else { Ok(res as usize) } } /// Get the last error, which happened in the underlying hidapi C library. /// /// The `Ok()` variant of the result will contain a [HidError::HidApiError](enum.HidError.html). /// /// When `Err()` is returned, then acquiring the error string from the hidapi C /// library failed. The contained [HidError](enum.HidError.html) is the cause, why no error could /// be fetched. pub fn check_error(&self) -> HidResult<HidError> { Ok(HidError::HidApiError { message: unsafe { wchar_to_string(ffi::hid_error(self._hid_device)) .map_err(|e| HidError::HidApiErrorEmptyWithCause { cause: Box::new(e) })? .ok_or(HidError::HidApiErrorEmpty)? }, }) } /// The first byte of `data` must contain the Report ID. For /// devices which only support a single report, this must be set /// to 0x0. The remaining bytes contain the report data. Since /// the Report ID is mandatory, calls to `write()` will always /// contain one more byte than the report contains. For example, /// if a hid report is 16 bytes long, 17 bytes must be passed to /// `write()`, the Report ID (or 0x0, for devices with a /// single report), followed by the report data (16 bytes). In /// this example, the length passed in would be 17. /// `write()` will send the data on the first OUT endpoint, if /// one exists. If it does not, it will send the data through /// the Control Endpoint (Endpoint 0). pub fn write(&self, data: &[u8]) -> HidResult<usize> { if data.len() == 0 { return Err(HidError::InvalidZeroSizeData); } let res = unsafe { ffi::hid_write(self._hid_device, data.as_ptr(), data.len() as size_t) }; self.check_size(res) } /// Input reports are returned to the host through the 'INTERRUPT IN' /// endpoint. The first byte will contain the Report number if the device /// uses numbered reports. pub fn read(&self, buf: &mut [u8]) -> HidResult<usize> { let res = unsafe { ffi::hid_read(self._hid_device, buf.as_mut_ptr(), buf.len() as size_t) }; self.check_size(res) } /// Input reports are returned to the host through the 'INTERRUPT IN' /// endpoint. The first byte will contain the Report number if the device /// uses numbered reports. Timeout measured in milliseconds, set -1 for /// blocking wait. pub fn read_timeout(&self, buf: &mut [u8], timeout: i32) -> HidResult<usize> { let res = unsafe { ffi::hid_read_timeout( self._hid_device, buf.as_mut_ptr(), buf.len() as size_t, timeout, ) }; self.check_size(res) } /// Send a Feature report to the device. /// Feature reports are sent over the Control endpoint as a /// Set_Report transfer. The first byte of `data` must contain the /// 'Report ID'. For devices which only support a single report, this must /// be set to 0x0. The remaining bytes contain the report data. Since the /// 'Report ID' is mandatory, calls to `send_feature_report()` will always /// contain one more byte than the report contains. For example, if a hid /// report is 16 bytes long, 17 bytes must be passed to /// `send_feature_report()`: 'the Report ID' (or 0x0, for devices which /// do not use numbered reports), followed by the report data (16 bytes). /// In this example, the length passed in would be 17. pub fn send_feature_report(&self, data: &[u8]) -> HidResult<()> { if data.len() == 0 { return Err(HidError::InvalidZeroSizeData); } let res = unsafe { ffi::hid_send_feature_report(self._hid_device, data.as_ptr(), data.len() as size_t) }; let res = self.check_size(res)?; if res != data.len() { Err(HidError::IncompleteSendError { sent: res, all: data.len(), }) } else { Ok(()) } } /// Set the first byte of `buf` to the 'Report ID' of the report to be read. /// Upon return, the first byte will still contain the Report ID, and the /// report data will start in buf[1]. pub fn get_feature_report(&self, buf: &mut [u8]) -> HidResult<usize> { let res = unsafe { ffi::hid_get_feature_report(self._hid_device, buf.as_mut_ptr(), buf.len() as size_t) }; self.check_size(res) } /// Set the device handle to be in blocking or in non-blocking mode. In /// non-blocking mode calls to `read()` will return immediately with an empty /// slice if there is no data to be read. In blocking mode, `read()` will /// wait (block) until there is data to read before returning. /// Modes can be changed at any time. pub fn set_blocking_mode(&self, blocking: bool) -> HidResult<()> { let res = unsafe { ffi::hid_set_nonblocking(self._hid_device, if blocking { 0i32 } else { 1i32 }) }; if res == -1 { Err(HidError::SetBlockingModeError { mode: match blocking { true => "blocking", false => "not blocking", }, }) } else { Ok(()) } } /// Get The Manufacturer String from a HID device. pub fn get_manufacturer_string(&self) -> HidResult<Option<String>> { let mut buf = [0 as wchar_t; STRING_BUF_LEN]; let res = unsafe { ffi::hid_get_manufacturer_string( self._hid_device, buf.as_mut_ptr(), STRING_BUF_LEN as size_t, ) }; let res = self.check_size(res)?; unsafe { wchar_to_string(buf[..res].as_ptr()) } } /// Get The Manufacturer String from a HID device. pub fn get_product_string(&self) -> HidResult<Option<String>> { let mut buf = [0 as wchar_t; STRING_BUF_LEN]; let res = unsafe { ffi::hid_get_product_string( self._hid_device, buf.as_mut_ptr(), STRING_BUF_LEN as size_t, ) }; let res = self.check_size(res)?; unsafe { wchar_to_string(buf[..res].as_ptr()) } } /// Get The Serial Number String from a HID device. pub fn get_serial_number_string(&self) -> HidResult<Option<String>> { let mut buf = [0 as wchar_t; STRING_BUF_LEN]; let res = unsafe { ffi::hid_get_serial_number_string( self._hid_device, buf.as_mut_ptr(), STRING_BUF_LEN as size_t, ) }; let res = self.check_size(res)?; unsafe { wchar_to_string(buf[..res].as_ptr()) } } /// Get a string from a HID device, based on its string index. pub fn get_indexed_string(&self, index: i32) -> HidResult<Option<String>> { let mut buf = [0 as wchar_t; STRING_BUF_LEN]; let res = unsafe { ffi::hid_get_indexed_string( self._hid_device, index as c_int, buf.as_mut_ptr(), STRING_BUF_LEN, ) }; let res = self.check_size(res)?; unsafe { wchar_to_string(buf[..res].as_ptr()) } } }