1 /*- 2 * Copyright (c) 2016-2019 Hans Petter Selasky. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26 #include <netlink/netlink_snl_generic.h> 27 #ifdef LIBUSB_GLOBAL_INCLUDE_FILE 28 #include LIBUSB_GLOBAL_INCLUDE_FILE 29 #else 30 #include <assert.h> 31 #include <errno.h> 32 #include <poll.h> 33 #include <pthread.h> 34 #include <stdio.h> 35 #include <stdlib.h> 36 #include <string.h> 37 #include <unistd.h> 38 #include <time.h> 39 #include <sys/fcntl.h> 40 #include <sys/ioctl.h> 41 #include <sys/queue.h> 42 #include <sys/endian.h> 43 #include <sys/socket.h> 44 #include <sys/un.h> 45 #include <sys/module.h> 46 #include <sys/linker.h> 47 #endif 48 49 #define libusb_device_handle libusb20_device 50 51 #include "libusb20.h" 52 #include "libusb20_desc.h" 53 #include "libusb20_int.h" 54 #include "libusb.h" 55 #include "libusb10.h" 56 57 #define DEVDPIPE "/var/run/devd.seqpacket.pipe" 58 #define DEVCTL_MAXBUF 1024 59 60 typedef enum { 61 broken_event, 62 invalid_event, 63 valid_event, 64 } event_t; 65 66 static bool 67 netlink_init(libusb_context *ctx) 68 { 69 uint32_t group; 70 71 if (modfind("nlsysevent") < 0) 72 kldload("nlsysevent"); 73 if (modfind("nlsysevent") < 0) 74 return (false); 75 if (!snl_init(&ctx->ss, NETLINK_GENERIC) || (group = 76 snl_get_genl_mcast_group(&ctx->ss, "nlsysevent", "USB", NULL)) == 0) 77 return (false); 78 79 if (setsockopt(ctx->ss.fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &group, 80 sizeof(group)) == -1) 81 return (false); 82 83 ctx->usb_event_mode = usb_event_netlink; 84 return (true); 85 } 86 87 static bool 88 devd_init(libusb_context *ctx) 89 { 90 struct sockaddr_un devd_addr; 91 92 bzero(&devd_addr, sizeof(devd_addr)); 93 if ((ctx->devd_pipe = socket(PF_LOCAL, SOCK_SEQPACKET|SOCK_NONBLOCK, 0)) < 0) 94 return (false); 95 96 devd_addr.sun_family = PF_LOCAL; 97 strlcpy(devd_addr.sun_path, DEVDPIPE, sizeof(devd_addr.sun_path)); 98 if (connect(ctx->devd_pipe, (struct sockaddr *)&devd_addr, 99 sizeof(devd_addr)) == -1) { 100 close(ctx->devd_pipe); 101 ctx->devd_pipe = -1; 102 return (false); 103 } 104 105 ctx->usb_event_mode = usb_event_devd; 106 return (true); 107 } 108 109 struct nlevent { 110 const char *name; 111 const char *subsystem; 112 const char *type; 113 const char *data; 114 }; 115 116 #define _OUT(_field) offsetof(struct nlevent, _field) 117 static struct snl_attr_parser ap_nlevent_get[] = { 118 { .type = NLSE_ATTR_SYSTEM, .off = _OUT(name), .cb = snl_attr_get_string }, 119 { .type = NLSE_ATTR_SUBSYSTEM, .off = _OUT(subsystem), .cb = snl_attr_get_string }, 120 { .type = NLSE_ATTR_TYPE, .off = _OUT(type), .cb = snl_attr_get_string }, 121 { .type = NLSE_ATTR_DATA, .off = _OUT(data), .cb = snl_attr_get_string }, 122 }; 123 #undef _OUT 124 125 SNL_DECLARE_GENL_PARSER(nlevent_get_parser, ap_nlevent_get); 126 127 static event_t 128 verify_event_validity(libusb_context *ctx) 129 { 130 if (ctx->usb_event_mode == usb_event_netlink) { 131 struct nlmsghdr *hdr; 132 struct nlevent ne; 133 134 hdr = snl_read_message(&ctx->ss); 135 if (hdr != NULL && hdr->nlmsg_type != NLMSG_ERROR) { 136 memset(&ne, 0, sizeof(ne)); 137 if (!snl_parse_nlmsg(&ctx->ss, hdr, &nlevent_get_parser, &ne)) 138 return (broken_event); 139 if (strcmp(ne.subsystem, "DEVICE") == 0) 140 return (valid_event); 141 return (invalid_event); 142 } 143 if (errno == EBADF) 144 return (broken_event); 145 return (invalid_event); 146 } else if (ctx->usb_event_mode == usb_event_devd) { 147 char buf[DEVCTL_MAXBUF]; 148 ssize_t len; 149 150 len = read(ctx->devd_pipe, buf, sizeof(buf)); 151 if (len == 0 || (len < 0 && errno != EWOULDBLOCK)) 152 return (broken_event); 153 if (len > 0 && strstr(buf, "system=USB") != NULL && 154 strstr(buf, "subsystem=DEVICE") != NULL) 155 return (valid_event); 156 return (invalid_event); 157 } 158 return (broken_event); 159 } 160 161 static int 162 libusb_hotplug_equal(libusb_device *_adev, libusb_device *_bdev) 163 { 164 struct libusb20_device *adev = _adev->os_priv; 165 struct libusb20_device *bdev = _bdev->os_priv; 166 167 if (adev->bus_number != bdev->bus_number) 168 return (0); 169 if (adev->device_address != bdev->device_address) 170 return (0); 171 if (memcmp(&adev->ddesc, &bdev->ddesc, sizeof(adev->ddesc))) 172 return (0); 173 if (memcmp(&adev->session_data, &bdev->session_data, sizeof(adev->session_data))) 174 return (0); 175 return (1); 176 } 177 178 static int 179 libusb_hotplug_filter(libusb_context *ctx, libusb_hotplug_callback_handle pcbh, 180 libusb_device *dev, libusb_hotplug_event event) 181 { 182 if (!(pcbh->events & event)) 183 return (0); 184 if (pcbh->vendor != LIBUSB_HOTPLUG_MATCH_ANY && 185 pcbh->vendor != libusb20_dev_get_device_desc(dev->os_priv)->idVendor) 186 return (0); 187 if (pcbh->product != LIBUSB_HOTPLUG_MATCH_ANY && 188 pcbh->product != libusb20_dev_get_device_desc(dev->os_priv)->idProduct) 189 return (0); 190 if (pcbh->devclass != LIBUSB_HOTPLUG_MATCH_ANY && 191 pcbh->devclass != libusb20_dev_get_device_desc(dev->os_priv)->bDeviceClass) 192 return (0); 193 return (pcbh->fn(ctx, dev, event, pcbh->user_data)); 194 } 195 196 static int 197 libusb_hotplug_enumerate(libusb_context *ctx, struct libusb_device_head *phead) 198 { 199 libusb_device **ppdev; 200 ssize_t count; 201 ssize_t x; 202 203 count = libusb_get_device_list(ctx, &ppdev); 204 if (count < 0) 205 return (-1); 206 207 for (x = 0; x != count; x++) 208 TAILQ_INSERT_TAIL(phead, ppdev[x], hotplug_entry); 209 210 libusb_free_device_list(ppdev, 0); 211 return (0); 212 } 213 214 static void * 215 libusb_hotplug_scan(void *arg) 216 { 217 struct pollfd pfd; 218 struct libusb_device_head hotplug_devs; 219 libusb_hotplug_callback_handle acbh; 220 libusb_hotplug_callback_handle bcbh; 221 libusb_context *ctx = arg; 222 libusb_device *temp; 223 libusb_device *adev; 224 libusb_device *bdev; 225 int timeout = INFTIM; 226 int nfds; 227 228 memset(&pfd, 0, sizeof(pfd)); 229 if (ctx->usb_event_mode == usb_event_devd) { 230 pfd.fd = ctx->devd_pipe; 231 pfd.events = POLLIN | POLLERR; 232 nfds = 1; 233 } else if (ctx->usb_event_mode == usb_event_netlink) { 234 pfd.fd = ctx->ss.fd; 235 pfd.events = POLLIN | POLLERR; 236 nfds = 1; 237 } else { 238 nfds = 0; 239 timeout = 4000; 240 } 241 for (;;) { 242 pfd.revents = 0; 243 if (poll(&pfd, nfds, timeout) > 0) { 244 switch (verify_event_validity(ctx)) { 245 case invalid_event: 246 continue; 247 case valid_event: 248 break; 249 case broken_event: 250 /* There are 2 cases for broken events: 251 * - devd and netlink sockets are not available 252 * anymore (devd restarted, nlsysevent unloaded) 253 * - libusb_exit has been called as it sets NO_THREAD 254 * this will result in exiting this loop and this thread 255 * immediately 256 */ 257 nfds = 0; 258 if (ctx->usb_event_mode == usb_event_devd) { 259 if (ctx->devd_pipe != -1) 260 close(ctx->devd_pipe); 261 } else if (ctx->usb_event_mode == usb_event_netlink) { 262 if (ctx->ss.fd != -1) 263 close(ctx->ss.fd); 264 } 265 ctx->usb_event_mode = usb_event_scan; 266 timeout = 4000; 267 break; 268 } 269 } 270 271 HOTPLUG_LOCK(ctx); 272 if (ctx->hotplug_handler == NO_THREAD) { 273 while ((adev = TAILQ_FIRST(&ctx->hotplug_devs)) != NULL) { 274 TAILQ_REMOVE(&ctx->hotplug_devs, adev, hotplug_entry); 275 libusb_unref_device(adev); 276 } 277 if (ctx->usb_event_mode == usb_event_devd) 278 close(ctx->devd_pipe); 279 else if (ctx->usb_event_mode == usb_event_netlink) 280 close(ctx->ss.fd); 281 HOTPLUG_UNLOCK(ctx); 282 break; 283 } 284 285 TAILQ_INIT(&hotplug_devs); 286 287 if (libusb_hotplug_enumerate(ctx, &hotplug_devs) < 0) { 288 HOTPLUG_UNLOCK(ctx); 289 continue; 290 } 291 292 /* figure out which devices are gone */ 293 TAILQ_FOREACH_SAFE(adev, &ctx->hotplug_devs, hotplug_entry, temp) { 294 TAILQ_FOREACH(bdev, &hotplug_devs, hotplug_entry) { 295 if (libusb_hotplug_equal(adev, bdev)) 296 break; 297 } 298 if (bdev == NULL) { 299 TAILQ_REMOVE(&ctx->hotplug_devs, adev, hotplug_entry); 300 TAILQ_FOREACH_SAFE(acbh, &ctx->hotplug_cbh, entry, bcbh) { 301 if (libusb_hotplug_filter(ctx, acbh, adev, 302 LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT) == 0) 303 continue; 304 TAILQ_REMOVE(&ctx->hotplug_cbh, acbh, entry); 305 free(acbh); 306 } 307 libusb_unref_device(adev); 308 } 309 } 310 311 /* figure out which devices are new */ 312 TAILQ_FOREACH_SAFE(adev, &hotplug_devs, hotplug_entry, temp) { 313 TAILQ_FOREACH(bdev, &ctx->hotplug_devs, hotplug_entry) { 314 if (libusb_hotplug_equal(adev, bdev)) 315 break; 316 } 317 if (bdev == NULL) { 318 TAILQ_REMOVE(&hotplug_devs, adev, hotplug_entry); 319 TAILQ_INSERT_TAIL(&ctx->hotplug_devs, adev, hotplug_entry); 320 TAILQ_FOREACH_SAFE(acbh, &ctx->hotplug_cbh, entry, bcbh) { 321 if (libusb_hotplug_filter(ctx, acbh, adev, 322 LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED) == 0) 323 continue; 324 TAILQ_REMOVE(&ctx->hotplug_cbh, acbh, entry); 325 free(acbh); 326 } 327 } 328 } 329 HOTPLUG_UNLOCK(ctx); 330 331 /* unref remaining devices */ 332 while ((adev = TAILQ_FIRST(&hotplug_devs)) != NULL) { 333 TAILQ_REMOVE(&hotplug_devs, adev, hotplug_entry); 334 libusb_unref_device(adev); 335 } 336 } 337 return (NULL); 338 } 339 340 int libusb_hotplug_register_callback(libusb_context *ctx, 341 libusb_hotplug_event events, libusb_hotplug_flag flags, 342 int vendor_id, int product_id, int dev_class, 343 libusb_hotplug_callback_fn cb_fn, void *user_data, 344 libusb_hotplug_callback_handle *phandle) 345 { 346 libusb_hotplug_callback_handle handle; 347 struct libusb_device *adev; 348 349 ctx = GET_CONTEXT(ctx); 350 351 if (ctx->usb_event_mode == usb_event_none) { 352 HOTPLUG_LOCK(ctx); 353 if (!netlink_init(ctx) && !devd_init(ctx)) 354 ctx->usb_event_mode = usb_event_scan; 355 HOTPLUG_UNLOCK(ctx); 356 } 357 358 if (ctx == NULL || cb_fn == NULL || events == 0 || 359 vendor_id < -1 || vendor_id > 0xffff || 360 product_id < -1 || product_id > 0xffff || 361 dev_class < -1 || dev_class > 0xff) 362 return (LIBUSB_ERROR_INVALID_PARAM); 363 364 handle = malloc(sizeof(*handle)); 365 if (handle == NULL) 366 return (LIBUSB_ERROR_NO_MEM); 367 368 HOTPLUG_LOCK(ctx); 369 if (ctx->hotplug_handler == NO_THREAD) { 370 libusb_hotplug_enumerate(ctx, &ctx->hotplug_devs); 371 372 if (pthread_create(&ctx->hotplug_handler, NULL, 373 &libusb_hotplug_scan, ctx) != 0) 374 ctx->hotplug_handler = NO_THREAD; 375 } 376 handle->events = events; 377 handle->vendor = vendor_id; 378 handle->product = product_id; 379 handle->devclass = dev_class; 380 handle->fn = cb_fn; 381 handle->user_data = user_data; 382 383 if (flags & LIBUSB_HOTPLUG_ENUMERATE) { 384 TAILQ_FOREACH(adev, &ctx->hotplug_devs, hotplug_entry) { 385 if (libusb_hotplug_filter(ctx, handle, adev, 386 LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED) == 0) 387 continue; 388 free(handle); 389 handle = NULL; 390 break; 391 } 392 } 393 if (handle != NULL) 394 TAILQ_INSERT_TAIL(&ctx->hotplug_cbh, handle, entry); 395 HOTPLUG_UNLOCK(ctx); 396 397 if (phandle != NULL) 398 *phandle = handle; 399 return (LIBUSB_SUCCESS); 400 } 401 402 void libusb_hotplug_deregister_callback(libusb_context *ctx, 403 libusb_hotplug_callback_handle handle) 404 { 405 ctx = GET_CONTEXT(ctx); 406 407 if (ctx == NULL || handle == NULL) 408 return; 409 410 HOTPLUG_LOCK(ctx); 411 TAILQ_REMOVE(&ctx->hotplug_cbh, handle, entry); 412 libusb_interrupt_event_handler(ctx); 413 HOTPLUG_UNLOCK(ctx); 414 415 free(handle); 416 } 417 418 void * 419 libusb_hotplug_get_user_data(struct libusb_context *ctx, 420 libusb_hotplug_callback_handle callback_handle) 421 { 422 libusb_hotplug_callback_handle handle; 423 424 ctx = GET_CONTEXT(ctx); 425 426 HOTPLUG_LOCK(ctx); 427 TAILQ_FOREACH(handle, &ctx->hotplug_cbh, entry) { 428 if (handle == callback_handle) 429 break; 430 } 431 HOTPLUG_UNLOCK(ctx); 432 433 return (handle); 434 } 435