libusb/os/linux_usbfs.c

   1 /* -*- Mode: C; c-basic-offset:8 ; indent-tabs-mode:t -*- */
   2 /*
   3  * Linux usbfs backend for libusb
   4  * Copyright © 2007-2009 Daniel Drake <dsd@gentoo.org>
   5  * Copyright © 2001 Johannes Erdfelt <johannes@erdfelt.com>
   6  * Copyright © 2013 Nathan Hjelm <hjelmn@mac.com>
   7  * Copyright © 2012-2013 Hans de Goede <hdegoede@redhat.com>
   8  * Copyright © 2020 Chris Dickens <christopher.a.dickens@gmail.com>
   9  *
  10  * This library is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2.1 of the License, or (at your option) any later version.
  14  *
  15  * This library is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with this library; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  23  */
  24
  25 #include "libusbi.h"
  26 #include "linux_usbfs.h"
  27
  28 #include <alloca.h>
  29 #include <ctype.h>
  30 #include <dirent.h>
  31 #include <errno.h>
  32 #include <fcntl.h>
  33 #include <stdio.h>
  34 #include <string.h>
  35 #include <sys/ioctl.h>
  36 #include <sys/mman.h>
  37 #include <sys/utsname.h>
  38 #include <sys/vfs.h>
  39
  40 /* sysfs vs usbfs:
  41  * opening a usbfs node causes the device to be resumed, so we attempt to
  42  * avoid this during enumeration.
  43  *
  44  * sysfs allows us to read the kernel's in-memory copies of device descriptors
  45  * and so forth, avoiding the need to open the device:
  46  *  - The binary "descriptors" file contains all config descriptors since
  47  *    2.6.26, commit 217a9081d8e69026186067711131b77f0ce219ed
  48  *  - The binary "descriptors" file was added in 2.6.23, commit
  49  *    69d42a78f935d19384d1f6e4f94b65bb162b36df, but it only contains the
  50  *    active config descriptors
  51  *  - The "busnum" file was added in 2.6.22, commit
  52  *    83f7d958eab2fbc6b159ee92bf1493924e1d0f72
  53  *  - The "devnum" file has been present since pre-2.6.18
  54  *  - the "bConfigurationValue" file has been present since pre-2.6.18
  55  *
  56  * If we have bConfigurationValue, busnum, and devnum, then we can determine
  57  * the active configuration without having to open the usbfs node in RDWR mode.
  58  * The busnum file is important as that is the only way we can relate sysfs
  59  * devices to usbfs nodes.
  60  *
  61  * If we also have all descriptors, we can obtain the device descriptor and
  62  * configuration without touching usbfs at all.
  63  */
  64
  65 /* endianness for multi-byte fields:
  66  *
  67  * Descriptors exposed by usbfs have the multi-byte fields in the device
  68  * descriptor as host endian. Multi-byte fields in the other descriptors are
  69  * bus-endian. The kernel documentation says otherwise, but it is wrong.
  70  *
  71  * In sysfs all descriptors are bus-endian.
  72  */
  73
  74 #define USBDEV_PATH             "/dev"
  75 #define USB_DEVTMPFS_PATH       "/dev/bus/usb"
  76
  77 /* use usbdev*.* device names in /dev instead of the usbfs bus directories */
  78 static int usbdev_names = 0;
  79
  80 /* Linux has changed the maximum length of an individual isochronous packet
  81  * over time.  Initially this limit was 1,023 bytes, but Linux 2.6.18
  82  * (commit 3612242e527eb47ee4756b5350f8bdf791aa5ede) increased this value to
  83  * 8,192 bytes to support higher bandwidth devices.  Linux 3.10
  84  * (commit e2e2f0ea1c935edcf53feb4c4c8fdb4f86d57dd9) further increased this
  85  * value to 49,152 bytes to support super speed devices.  Linux 5.2
  86  * (commit 8a1dbc8d91d3d1602282c7e6b4222c7759c916fa) even further increased
  87  * this value to 98,304 bytes to support super speed plus devices.
  88  */
  89 static unsigned int max_iso_packet_len = 0;
  90
  91 /* is sysfs available (mounted) ? */
  92 static int sysfs_available = -1;
  93
  94 /* how many times have we initted (and not exited) ? */
  95 static int init_count = 0;
  96
  97 /* Serialize hotplug start/stop */
  98 static usbi_mutex_static_t linux_hotplug_startstop_lock = USBI_MUTEX_INITIALIZER;
  99 /* Serialize scan-devices, event-thread, and poll */
 100 usbi_mutex_static_t linux_hotplug_lock = USBI_MUTEX_INITIALIZER;
 101
 102 static int linux_scan_devices(struct libusb_context *ctx);
 103 static int detach_kernel_driver_and_claim(struct libusb_device_handle *, int);
 104
 105 #if !defined(HAVE_LIBUDEV)
 106 static int linux_default_scan_devices(struct libusb_context *ctx);
 107 #endif
 108
 109 struct kernel_version {
 110         int major;
 111         int minor;
 112         int sublevel;
 113 };
 114
 115 struct linux_device_priv {
 116         char *sysfs_dir;
 117         unsigned char *descriptors;
 118         int descriptors_len;
 119         int active_config; /* cache val for !sysfs_available  */
 120 };
 121
 122 struct linux_device_handle_priv {
 123         int fd;
 124         int fd_removed;
 125         int fd_keep;
 126         uint32_t caps;
 127 };
 128
 129 enum reap_action {
 130         NORMAL = 0,
 131         /* submission failed after the first URB, so await cancellation/completion
 132          * of all the others */
 133         SUBMIT_FAILED,
 134
 135         /* cancelled by user or timeout */
 136         CANCELLED,
 137
 138         /* completed multi-URB transfer in non-final URB */
 139         COMPLETED_EARLY,
 140
 141         /* one or more urbs encountered a low-level error */
 142         ERROR,
 143 };
 144
 145 struct linux_transfer_priv {
 146         union {
 147                 struct usbfs_urb *urbs;
 148                 struct usbfs_urb **iso_urbs;
 149         };
 150
 151         enum reap_action reap_action;
 152         int num_urbs;
 153         int num_retired;
 154         enum libusb_transfer_status reap_status;
 155
 156         /* next iso packet in user-supplied transfer to be populated */
 157         int iso_packet_offset;
 158 };
 159
 160 static int get_usbfs_fd(struct libusb_device *dev, mode_t mode, int silent)
 161 {
 162         struct libusb_context *ctx = DEVICE_CTX(dev);
 163         char path[24];
 164         int fd;
 165
 166         if (usbdev_names)
 167                 sprintf(path, USBDEV_PATH "/usbdev%u.%u",
 168                         dev->bus_number, dev->device_address);
 169         else
 170                 sprintf(path, USB_DEVTMPFS_PATH "/%03u/%03u",
 171                         dev->bus_number, dev->device_address);
 172
 173         fd = open(path, mode | O_CLOEXEC);
 174         if (fd != -1)
 175                 return fd; /* Success */
 176
 177         if (errno == ENOENT) {
 178                 const long delay_ms = 10L;
 179                 const struct timespec delay_ts = { 0L, delay_ms * 1000L * 1000L };
 180
 181                 if (!silent)
 182                         usbi_err(ctx, "File doesn't exist, wait %ld ms and try again", delay_ms);
 183
 184                 /* Wait 10ms for USB device path creation.*/
 185                 nanosleep(&delay_ts, NULL);
 186
 187                 fd = open(path, mode | O_CLOEXEC);
 188                 if (fd != -1)
 189                         return fd; /* Success */
 190         }
 191
 192         if (!silent) {
 193                 usbi_err(ctx, "libusb couldn't open USB device %s, errno=%d", path, errno);
 194                 if (errno == EACCES && mode == O_RDWR)
 195                         usbi_err(ctx, "libusb requires write access to USB device nodes");
 196         }
 197
 198         if (errno == EACCES)
 199                 return LIBUSB_ERROR_ACCESS;
 200         if (errno == ENOENT)
 201                 return LIBUSB_ERROR_NO_DEVICE;
 202         return LIBUSB_ERROR_IO;
 203 }
 204
 205 /* check dirent for a /dev/usbdev%d.%d name
 206  * optionally return bus/device on success */
 207 static int is_usbdev_entry(const char *name, uint8_t *bus_p, uint8_t *dev_p)
 208 {
 209         int busnum, devnum;
 210
 211         if (sscanf(name, "usbdev%d.%d", &busnum, &devnum) != 2)
 212                 return 0;
 213         if (busnum < 0 || busnum > UINT8_MAX || devnum < 0 || devnum > UINT8_MAX) {
 214                 usbi_dbg("invalid usbdev format '%s'", name);
 215                 return 0;
 216         }
 217
 218         usbi_dbg("found: %s", name);
 219         if (bus_p)
 220                 *bus_p = (uint8_t)busnum;
 221         if (dev_p)
 222                 *dev_p = (uint8_t)devnum;
 223         return 1;
 224 }
 225
 226 static const char *find_usbfs_path(void)
 227 {
 228         const char *path;
 229         DIR *dir;
 230         struct dirent *entry;
 231
 232         path = USB_DEVTMPFS_PATH;
 233         dir = opendir(path);
 234         if (dir) {
 235                 while ((entry = readdir(dir))) {
 236                         if (entry->d_name[0] == '.')
 237                                 continue;
 238
 239                         /* We assume if we find any files that it must be the right place */
 240                         break;
 241                 }
 242
 243                 closedir(dir);
 244
 245                 if (entry)
 246                         return path;
 247         }
 248
 249         /* look for /dev/usbdev*.* if the normal place fails */
 250         path = USBDEV_PATH;
 251         dir = opendir(path);
 252         if (dir) {
 253                 while ((entry = readdir(dir))) {
 254                         if (entry->d_name[0] == '.')
 255                                 continue;
 256
 257                         if (is_usbdev_entry(entry->d_name, NULL, NULL)) {
 258                                 /* found one; that's enough */
 259                                 break;
 260                         }
 261                 }
 262
 263                 closedir(dir);
 264
 265                 if (entry) {
 266                         usbdev_names = 1;
 267                         return path;
 268                 }
 269         }
 270
 271 /* On udev based systems without any usb-devices /dev/bus/usb will not
 272  * exist. So if we've not found anything and we're using udev for hotplug
 273  * simply assume /dev/bus/usb rather then making libusb_init fail.
 274  * Make the same assumption for Android where SELinux policies might block us
 275  * from reading /dev on newer devices. */
 276 #if defined(HAVE_LIBUDEV) || defined(__ANDROID__)
 277         return USB_DEVTMPFS_PATH;
 278 #else
 279         return NULL;
 280 #endif
 281 }
 282
 283 static int get_kernel_version(struct libusb_context *ctx,
 284         struct kernel_version *ver)
 285 {
 286         struct utsname uts;
 287         int atoms;
 288
 289         if (uname(&uts) < 0) {
 290                 usbi_err(ctx, "uname failed, errno=%d", errno);
 291                 return -1;
 292         }
 293
 294         atoms = sscanf(uts.release, "%d.%d.%d", &ver->major, &ver->minor, &ver->sublevel);
 295         if (atoms < 2) {
 296                 usbi_err(ctx, "failed to parse uname release '%s'", uts.release);
 297                 return -1;
 298         }
 299
 300         if (atoms < 3)
 301                 ver->sublevel = -1;
 302
 303         usbi_dbg("reported kernel version is %s", uts.release);
 304
 305         return 0;
 306 }
 307
 308 static int kernel_version_ge(const struct kernel_version *ver,
 309         int major, int minor, int sublevel)
 310 {
 311         if (ver->major > major)
 312                 return 1;
 313         else if (ver->major < major)
 314                 return 0;
 315
 316         /* kmajor == major */
 317         if (ver->minor > minor)
 318                 return 1;
 319         else if (ver->minor < minor)
 320                 return 0;
 321
 322         /* kminor == minor */
 323         if (ver->sublevel == -1)
 324                 return sublevel == 0;
 325
 326         return ver->sublevel >= sublevel;
 327 }
 328
 329 static int op_init(struct libusb_context *ctx)
 330 {
 331         struct kernel_version kversion;
 332         const char *usbfs_path;
 333         int r;
 334
 335         if (get_kernel_version(ctx, &kversion) < 0)
 336                 return LIBUSB_ERROR_OTHER;
 337
 338         if (!kernel_version_ge(&kversion, 2, 6, 32)) {
 339                 usbi_err(ctx, "kernel version is too old (reported as %d.%d.%d)",
 340                          kversion.major, kversion.minor,
 341                          kversion.sublevel != -1 ? kversion.sublevel : 0);
 342                 return LIBUSB_ERROR_NOT_SUPPORTED;
 343         }
 344
 345         usbfs_path = find_usbfs_path();
 346         if (!usbfs_path) {
 347                 usbi_err(ctx, "could not find usbfs");
 348                 return LIBUSB_ERROR_OTHER;
 349         }
 350
 351         usbi_dbg("found usbfs at %s", usbfs_path);
 352
 353         if (!max_iso_packet_len) {
 354                 if (kernel_version_ge(&kversion, 5, 2, 0))
 355                         max_iso_packet_len = 98304;
 356                 else if (kernel_version_ge(&kversion, 3, 10, 0))
 357                         max_iso_packet_len = 49152;
 358                 else
 359                         max_iso_packet_len = 8192;
 360         }
 361
 362         usbi_dbg("max iso packet length is (likely) %u bytes", max_iso_packet_len);
 363
 364         if (sysfs_available == -1) {
 365                 struct statfs statfsbuf;
 366
 367                 r = statfs(SYSFS_MOUNT_PATH, &statfsbuf);
 368                 if (r == 0 && statfsbuf.f_type == SYSFS_MAGIC) {
 369                         usbi_dbg("sysfs is available");
 370                         sysfs_available = 1;
 371                 } else {
 372                         usbi_warn(ctx, "sysfs not mounted");
 373                         sysfs_available = 0;
 374                 }
 375         }
 376
 377         usbi_mutex_static_lock(&linux_hotplug_startstop_lock);
 378         r = LIBUSB_SUCCESS;
 379         if (init_count == 0) {
 380                 /* start up hotplug event handler */
 381                 r = linux_start_event_monitor();
 382         }
 383         if (r == LIBUSB_SUCCESS) {
 384                 r = linux_scan_devices(ctx);
 385                 if (r == LIBUSB_SUCCESS)
 386                         init_count++;
 387                 else if (init_count == 0)
 388                         linux_stop_event_monitor();
 389         } else {
 390                 usbi_err(ctx, "error starting hotplug event monitor");
 391         }
 392         usbi_mutex_static_unlock(&linux_hotplug_startstop_lock);
 393
 394         return r;
 395 }
 396
 397 static void op_exit(struct libusb_context *ctx)
 398 {
 399         UNUSED(ctx);
 400         usbi_mutex_static_lock(&linux_hotplug_startstop_lock);
 401         assert(init_count != 0);
 402         if (!--init_count) {
 403                 /* tear down event handler */
 404                 linux_stop_event_monitor();
 405         }
 406         usbi_mutex_static_unlock(&linux_hotplug_startstop_lock);
 407 }
 408
 409 static int linux_scan_devices(struct libusb_context *ctx)
 410 {
 411         int ret;
 412
 413         usbi_mutex_static_lock(&linux_hotplug_lock);
 414
 415 #if defined(HAVE_LIBUDEV)
 416         ret = linux_udev_scan_devices(ctx);
 417 #else
 418         ret = linux_default_scan_devices(ctx);
 419 #endif
 420
 421         usbi_mutex_static_unlock(&linux_hotplug_lock);
 422
 423         return ret;
 424 }
 425
 426 static void op_hotplug_poll(void)
 427 {
 428         linux_hotplug_poll();
 429 }
 430
 431 static int open_sysfs_attr(struct libusb_context *ctx,
 432         const char *sysfs_dir, const char *attr)
 433 {
 434         char filename[256];
 435         int fd;
 436
 437         snprintf(filename, sizeof(filename), SYSFS_DEVICE_PATH "/%s/%s", sysfs_dir, attr);
 438         fd = open(filename, O_RDONLY | O_CLOEXEC);
 439         if (fd < 0) {
 440                 if (errno == ENOENT) {
 441                         /* File doesn't exist. Assume the device has been
 442                            disconnected (see trac ticket #70). */
 443                         return LIBUSB_ERROR_NO_DEVICE;
 444                 }
 445                 usbi_err(ctx, "open %s failed, errno=%d", filename, errno);
 446                 return LIBUSB_ERROR_IO;
 447         }
 448
 449         return fd;
 450 }
 451
 452 /* Note only suitable for attributes which always read >= 0, < 0 is error */
 453 static int read_sysfs_attr(struct libusb_context *ctx,
 454         const char *sysfs_dir, const char *attr, int max_value, int *value_p)
 455 {
 456         char buf[20], *endptr;
 457         long value;
 458         ssize_t r;
 459         int fd;
 460
 461         fd = open_sysfs_attr(ctx, sysfs_dir, attr);
 462         if (fd < 0)
 463                 return fd;
 464
 465         r = read(fd, buf, sizeof(buf));
 466         if (r < 0) {
 467                 r = errno;
 468                 close(fd);
 469                 if (r == ENODEV)
 470                         return LIBUSB_ERROR_NO_DEVICE;
 471                 usbi_err(ctx, "attribute %s read failed, errno=%zd", attr, r);
 472                 return LIBUSB_ERROR_IO;
 473         }
 474         close(fd);
 475
 476         if (r == 0) {
 477                 /* Certain attributes (e.g. bConfigurationValue) are not
 478                  * populated if the device is not configured. */
 479                 *value_p = -1;
 480                 return 0;
 481         }
 482
 483         /* The kernel does *not* NULL-terminate the string, but every attribute
 484          * should be terminated with a newline character. */
 485         if (!isdigit(buf[0])) {
 486                 usbi_err(ctx, "attribute %s doesn't have numeric value?", attr);
 487                 return LIBUSB_ERROR_IO;
 488         } else if (buf[r - 1] != '\n') {
 489                 usbi_err(ctx, "attribute %s doesn't end with newline?", attr);
 490                 return LIBUSB_ERROR_IO;
 491         }
 492         buf[r - 1] = '\0';
 493
 494         errno = 0;
 495         value = strtol(buf, &endptr, 10);
 496         if (value < 0 || value > (long)max_value || errno) {
 497                 usbi_err(ctx, "attribute %s contains an invalid value: '%s'", attr, buf);
 498                 return LIBUSB_ERROR_INVALID_PARAM;
 499         } else if (*endptr != '\0') {
 500                 /* Consider the value to be valid if the remainder is a '.'
 501                  * character followed by numbers.  This occurs, for example,
 502                  * when reading the "speed" attribute for a low-speed device
 503                  * (e.g. "1.5") */
 504                 if (*endptr == '.' && isdigit(*(endptr + 1))) {
 505                         endptr++;
 506                         while (isdigit(*endptr))
 507                                 endptr++;
 508                 }
 509                 if (*endptr != '\0') {
 510                         usbi_err(ctx, "attribute %s contains an invalid value: '%s'", attr, buf);
 511                         return LIBUSB_ERROR_INVALID_PARAM;
 512                 }
 513         }
 514
 515         *value_p = (int)value;
 516         return 0;
 517 }
 518
 519 static int op_get_device_descriptor(struct libusb_device *dev,
 520         unsigned char *buffer, int *host_endian)
 521 {
 522         struct linux_device_priv *priv = usbi_get_device_priv(dev);
 523
 524         *host_endian = priv->sysfs_dir != NULL;
 525         memcpy(buffer, priv->descriptors, LIBUSB_DT_DEVICE_SIZE);
 526
 527         return 0;
 528 }
 529
 530 static int sysfs_scan_device(struct libusb_context *ctx, const char *devname)
 531 {
 532         uint8_t busnum, devaddr;
 533         int ret;
 534
 535         ret = linux_get_device_address(ctx, 0, &busnum, &devaddr, NULL, devname, -1);
 536         if (ret != LIBUSB_SUCCESS)
 537                 return ret;
 538
 539         return linux_enumerate_device(ctx, busnum, devaddr, devname);
 540 }
 541
 542 /* read the bConfigurationValue for a device */
 543 static int sysfs_get_active_config(struct libusb_device *dev, int *config)
 544 {
 545         struct linux_device_priv *priv = usbi_get_device_priv(dev);
 546         int ret;
 547
 548         ret = read_sysfs_attr(DEVICE_CTX(dev), priv->sysfs_dir, "bConfigurationValue",
 549                                 UINT8_MAX, config);
 550         if (ret < 0)
 551                 return ret;
 552
 553         if (*config == -1)
 554                 usbi_dbg("device unconfigured");
 555
 556         return 0;
 557 }
 558
 559 int linux_get_device_address(struct libusb_context *ctx, int detached,
 560         uint8_t *busnum, uint8_t *devaddr, const char *dev_node,
 561         const char *sys_name, int fd)
 562 {
 563         int sysfs_val;
 564         int r;
 565
 566         usbi_dbg("getting address for device: %s detached: %d", sys_name, detached);
 567         /* can't use sysfs to read the bus and device number if the
 568          * device has been detached */
 569         if (!sysfs_available || detached || !sys_name) {
 570                 if (!dev_node && fd >= 0) {
 571                         char *fd_path = alloca(PATH_MAX);
 572                         char proc_path[32];
 573
 574                         /* try to retrieve the device node from fd */
 575                         sprintf(proc_path, "/proc/self/fd/%d", fd);
 576                         r = readlink(proc_path, fd_path, PATH_MAX - 1);
 577                         if (r > 0) {
 578                                 fd_path[r] = '\0';
 579                                 dev_node = fd_path;
 580                         }
 581                 }
 582
 583                 if (!dev_node)
 584                         return LIBUSB_ERROR_OTHER;
 585
 586                 /* will this work with all supported kernel versions? */
 587                 if (!strncmp(dev_node, "/dev/bus/usb", 12))
 588                         sscanf(dev_node, "/dev/bus/usb/%hhu/%hhu", busnum, devaddr);
 589                 else
 590                         return LIBUSB_ERROR_OTHER;
 591
 592                 return LIBUSB_SUCCESS;
 593         }
 594
 595         usbi_dbg("scan %s", sys_name);
 596
 597         r = read_sysfs_attr(ctx, sys_name, "busnum", UINT8_MAX, &sysfs_val);
 598         if (r < 0)
 599                 return r;
 600         *busnum = (uint8_t)sysfs_val;
 601
 602         r = read_sysfs_attr(ctx, sys_name, "devnum", UINT8_MAX, &sysfs_val);
 603         if (r < 0)
 604                 return r;
 605         *devaddr = (uint8_t)sysfs_val;
 606
 607         usbi_dbg("bus=%u dev=%u", *busnum, *devaddr);
 608
 609         return LIBUSB_SUCCESS;
 610 }
 611
 612 /* Return offset of the next descriptor with the given type */
 613 static int seek_to_next_descriptor(struct libusb_context *ctx,
 614         uint8_t descriptor_type, unsigned char *buffer, int size)
 615 {
 616         struct usbi_descriptor_header *header;
 617         int i;
 618
 619         for (i = 0; size >= 0; i += header->bLength, size -= header->bLength) {
 620                 if (size == 0)
 621                         return LIBUSB_ERROR_NOT_FOUND;
 622
 623                 if (size < 2) {
 624                         usbi_err(ctx, "short descriptor read %d/2", size);
 625                         return LIBUSB_ERROR_IO;
 626                 }
 627
 628                 header = (struct usbi_descriptor_header *)(buffer + i);
 629                 if (i && header->bDescriptorType == descriptor_type)
 630                         return i;
 631         }
 632         usbi_err(ctx, "bLength overflow by %d bytes", -size);
 633         return LIBUSB_ERROR_IO;
 634 }
 635
 636 /* Return offset to next config */
 637 static int seek_to_next_config(struct libusb_device *dev,
 638         unsigned char *buffer, int size)
 639 {
 640         struct libusb_context *ctx = DEVICE_CTX(dev);
 641         struct linux_device_priv *priv = usbi_get_device_priv(dev);
 642         struct usbi_configuration_descriptor *config;
 643         uint16_t config_len;
 644
 645         if (size == 0)
 646                 return LIBUSB_ERROR_NOT_FOUND;
 647
 648         if (size < LIBUSB_DT_CONFIG_SIZE) {
 649                 usbi_err(ctx, "short descriptor read %d/%d",
 650                          size, LIBUSB_DT_CONFIG_SIZE);
 651                 return LIBUSB_ERROR_IO;
 652         }
 653
 654         config = (struct usbi_configuration_descriptor *)buffer;
 655         if (config->bDescriptorType != LIBUSB_DT_CONFIG) {
 656                 usbi_err(ctx, "descriptor is not a config desc (type 0x%02x)",
 657                          config->bDescriptorType);
 658                 return LIBUSB_ERROR_IO;
 659         }
 660
 661         config_len = libusb_le16_to_cpu(config->wTotalLength);
 662         /*
 663          * In usbfs the config descriptors are wTotalLength bytes apart,
 664          * with any short reads from the device appearing as holes in the file.
 665          *
 666          * In sysfs wTotalLength is ignored, instead the kernel returns a
 667          * config descriptor with verified bLength fields, with descriptors
 668          * with an invalid bLength removed.
 669          */
 670         if (priv->sysfs_dir) {
 671                 int next = seek_to_next_descriptor(ctx, LIBUSB_DT_CONFIG, buffer, size);
 672
 673                 if (next == LIBUSB_ERROR_NOT_FOUND)
 674                         next = size;
 675                 if (next < 0)
 676                         return next;
 677
 678                 if (next != config_len)
 679                         usbi_warn(ctx, "config length mismatch wTotalLength %u real %d",
 680                                   config_len, next);
 681                 return next;
 682         } else {
 683                 if (config_len < LIBUSB_DT_CONFIG_SIZE) {
 684                         usbi_err(ctx, "invalid wTotalLength %u", config_len);
 685                         return LIBUSB_ERROR_IO;
 686                 } else if (config_len > size) {
 687                         usbi_warn(ctx, "short descriptor read %d/%u",
 688                                   size, config_len);
 689                         return size;
 690                 } else {
 691                         return config_len;
 692                 }
 693         }
 694 }
 695
 696 static int op_get_config_descriptor_by_value(struct libusb_device *dev,
 697         uint8_t value, unsigned char **buffer)
 698 {
 699         struct linux_device_priv *priv = usbi_get_device_priv(dev);
 700         unsigned char *descriptors = priv->descriptors;
 701         int size = priv->descriptors_len;
 702         struct usbi_configuration_descriptor *config;
 703
 704         *buffer = NULL;
 705
 706         /* Skip device header */
 707         descriptors += LIBUSB_DT_DEVICE_SIZE;
 708         size -= LIBUSB_DT_DEVICE_SIZE;
 709
 710         /* Seek till the config is found, or till "EOF" */
 711         while (1) {
 712                 int next = seek_to_next_config(dev, descriptors, size);
 713
 714                 if (next < 0)
 715                         return next;
 716                 config = (struct usbi_configuration_descriptor *)descriptors;
 717                 if (config->bConfigurationValue == value) {
 718                         *buffer = descriptors;
 719                         return next;
 720                 }
 721                 size -= next;
 722                 descriptors += next;
 723         }
 724 }
 725
 726 static int op_get_active_config_descriptor(struct libusb_device *dev,
 727         unsigned char *buffer, size_t len)
 728 {
 729         struct linux_device_priv *priv = usbi_get_device_priv(dev);
 730         int r, config;
 731         unsigned char *config_desc;
 732
 733         if (priv->sysfs_dir) {
 734                 r = sysfs_get_active_config(dev, &config);
 735                 if (r < 0)
 736                         return r;
 737         } else {
 738                 /* Use cached bConfigurationValue */
 739                 config = priv->active_config;
 740         }
 741         if (config == -1)
 742                 return LIBUSB_ERROR_NOT_FOUND;
 743
 744         r = op_get_config_descriptor_by_value(dev, config, &config_desc);
 745         if (r < 0)
 746                 return r;
 747
 748         len = MIN(len, (size_t)r);
 749         memcpy(buffer, config_desc, len);
 750         return len;
 751 }
 752
 753 static int op_get_config_descriptor(struct libusb_device *dev,
 754         uint8_t config_index, unsigned char *buffer, size_t len)
 755 {
 756         struct linux_device_priv *priv = usbi_get_device_priv(dev);
 757         unsigned char *descriptors = priv->descriptors;
 758         int i, r, size = priv->descriptors_len;
 759
 760         /* Skip device header */
 761         descriptors += LIBUSB_DT_DEVICE_SIZE;
 762         size -= LIBUSB_DT_DEVICE_SIZE;
 763
 764         /* Seek till the config is found, or till "EOF" */
 765         for (i = 0; ; i++) {
 766                 r = seek_to_next_config(dev, descriptors, size);
 767                 if (r < 0)
 768                         return r;
 769                 if (i == config_index)
 770                         break;
 771                 size -= r;
 772                 descriptors += r;
 773         }
 774
 775         len = MIN(len, (size_t)r);
 776         memcpy(buffer, descriptors, len);
 777         return len;
 778 }
 779
 780 /* send a control message to retrieve active configuration */
 781 static int usbfs_get_active_config(struct libusb_device *dev, int fd)
 782 {
 783         struct linux_device_priv *priv = usbi_get_device_priv(dev);
 784         unsigned char active_config = 0;
 785         int r;
 786
 787         struct usbfs_ctrltransfer ctrl = {
 788                 .bmRequestType = LIBUSB_ENDPOINT_IN,
 789                 .bRequest = LIBUSB_REQUEST_GET_CONFIGURATION,
 790                 .wValue = 0,
 791                 .wIndex = 0,
 792                 .wLength = 1,
 793                 .timeout = 1000,
 794                 .data = &active_config
 795         };
 796
 797         r = ioctl(fd, IOCTL_USBFS_CONTROL, &ctrl);
 798         if (r < 0) {
 799                 if (errno == ENODEV)
 800                         return LIBUSB_ERROR_NO_DEVICE;
 801
 802                 /* we hit this error path frequently with buggy devices :( */
 803                 usbi_warn(DEVICE_CTX(dev), "get configuration failed, errno=%d", errno);
 804                 priv->active_config = -1;
 805         } else {
 806                 if (active_config > 0) {
 807                         priv->active_config = active_config;
 808                 } else {
 809                         /* some buggy devices have a configuration 0, but we're
 810                          * reaching into the corner of a corner case here, so let's
 811                          * not support buggy devices in these circumstances.
 812                          * stick to the specs: a configuration value of 0 means
 813                          * unconfigured. */
 814                         usbi_warn(DEVICE_CTX(dev), "active cfg 0? assuming unconfigured device");
 815                         priv->active_config = -1;
 816                 }
 817         }
 818
 819         return LIBUSB_SUCCESS;
 820 }
 821
 822 static int initialize_device(struct libusb_device *dev, uint8_t busnum,
 823         uint8_t devaddr, const char *sysfs_dir, int wrapped_fd)
 824 {
 825         struct linux_device_priv *priv = usbi_get_device_priv(dev);
 826         struct libusb_context *ctx = DEVICE_CTX(dev);
 827         int descriptors_size = 0;
 828         int fd, speed;
 829         ssize_t r;
 830
 831         dev->bus_number = busnum;
 832         dev->device_address = devaddr;
 833
 834         if (sysfs_dir) {
 835                 priv->sysfs_dir = strdup(sysfs_dir);
 836                 if (!priv->sysfs_dir)
 837                         return LIBUSB_ERROR_NO_MEM;
 838
 839                 /* Note speed can contain 1.5, in this case read_sysfs_attr()
 840                    will stop parsing at the '.' and return 1 */
 841                 if (read_sysfs_attr(ctx, sysfs_dir, "speed", INT_MAX, &speed) == 0) {
 842                         switch (speed) {
 843                         case     1: dev->speed = LIBUSB_SPEED_LOW; break;
 844                         case    12: dev->speed = LIBUSB_SPEED_FULL; break;
 845                         case   480: dev->speed = LIBUSB_SPEED_HIGH; break;
 846                         case  5000: dev->speed = LIBUSB_SPEED_SUPER; break;
 847                         case 10000: dev->speed = LIBUSB_SPEED_SUPER_PLUS; break;
 848                         default:
 849                                 usbi_warn(ctx, "unknown device speed: %d Mbps", speed);
 850                         }
 851                 }
 852         }
 853
 854         /* cache descriptors in memory */
 855         if (sysfs_dir) {
 856                 fd = open_sysfs_attr(ctx, sysfs_dir, "descriptors");
 857         } else if (wrapped_fd < 0) {
 858                 fd = get_usbfs_fd(dev, O_RDONLY, 0);
 859         } else {
 860                 fd = wrapped_fd;
 861                 r = lseek(fd, 0, SEEK_SET);
 862                 if (r < 0) {
 863                         usbi_err(ctx, "lseek failed, errno=%d", errno);
 864                         return LIBUSB_ERROR_IO;
 865                 }
 866         }
 867         if (fd < 0)
 868                 return fd;
 869
 870         do {
 871                 descriptors_size += 256;
 872                 priv->descriptors = usbi_reallocf(priv->descriptors, descriptors_size);
 873                 if (!priv->descriptors) {
 874                         if (fd != wrapped_fd)
 875                                 close(fd);
 876                         return LIBUSB_ERROR_NO_MEM;
 877                 }
 878                 /* usbfs has holes in the file */
 879                 if (!sysfs_dir) {
 880                         memset(priv->descriptors + priv->descriptors_len,
 881                                0, descriptors_size - priv->descriptors_len);
 882                 }
 883                 r = read(fd, priv->descriptors + priv->descriptors_len,
 884                          descriptors_size - priv->descriptors_len);
 885                 if (r < 0) {
 886                         usbi_err(ctx, "read descriptor failed, errno=%d", errno);
 887                         if (fd != wrapped_fd)
 888                                 close(fd);
 889                         return LIBUSB_ERROR_IO;
 890                 }
 891                 priv->descriptors_len += r;
 892         } while (priv->descriptors_len == descriptors_size);
 893
 894         if (fd != wrapped_fd)
 895                 close(fd);
 896
 897         if (priv->descriptors_len < LIBUSB_DT_DEVICE_SIZE) {
 898                 usbi_err(ctx, "short descriptor read (%d)", priv->descriptors_len);
 899                 return LIBUSB_ERROR_IO;
 900         }
 901
 902         if (sysfs_dir)
 903                 return LIBUSB_SUCCESS;
 904
 905         /* cache active config */
 906         if (wrapped_fd < 0)
 907                 fd = get_usbfs_fd(dev, O_RDWR, 1);
 908         else
 909                 fd = wrapped_fd;
 910         if (fd < 0) {
 911                 /* cannot send a control message to determine the active
 912                  * config. just assume the first one is active. */
 913                 usbi_warn(ctx, "Missing rw usbfs access; cannot determine "
 914                                "active configuration descriptor");
 915                 if (priv->descriptors_len >= (LIBUSB_DT_DEVICE_SIZE + LIBUSB_DT_CONFIG_SIZE)) {
 916                         struct usbi_configuration_descriptor *config;
 917
 918                         config = (struct usbi_configuration_descriptor *)(priv->descriptors + LIBUSB_DT_DEVICE_SIZE);
 919                         priv->active_config = config->bConfigurationValue;
 920                 } else {
 921                         priv->active_config = -1; /* No config dt */
 922                 }
 923
 924                 return LIBUSB_SUCCESS;
 925         }
 926
 927         r = usbfs_get_active_config(dev, fd);
 928         if (fd != wrapped_fd)
 929                 close(fd);
 930
 931         return r;
 932 }
 933
 934 static int linux_get_parent_info(struct libusb_device *dev, const char *sysfs_dir)
 935 {
 936         struct libusb_context *ctx = DEVICE_CTX(dev);
 937         struct libusb_device *it;
 938         char *parent_sysfs_dir, *tmp;
 939         int ret, add_parent = 1;
 940
 941         /* XXX -- can we figure out the topology when using usbfs? */
 942         if (!sysfs_dir || !strncmp(sysfs_dir, "usb", 3)) {
 943                 /* either using usbfs or finding the parent of a root hub */
 944                 return LIBUSB_SUCCESS;
 945         }
 946
 947         parent_sysfs_dir = strdup(sysfs_dir);
 948         if (!parent_sysfs_dir)
 949                 return LIBUSB_ERROR_NO_MEM;
 950
 951         if ((tmp = strrchr(parent_sysfs_dir, '.')) ||
 952             (tmp = strrchr(parent_sysfs_dir, '-'))) {
 953                 dev->port_number = atoi(tmp + 1);
 954                 *tmp = '\0';
 955         } else {
 956                 usbi_warn(ctx, "Can not parse sysfs_dir: %s, no parent info",
 957                           parent_sysfs_dir);
 958                 free(parent_sysfs_dir);
 959                 return LIBUSB_SUCCESS;
 960         }
 961
 962         /* is the parent a root hub? */
 963         if (!strchr(parent_sysfs_dir, '-')) {
 964                 tmp = parent_sysfs_dir;
 965                 ret = asprintf(&parent_sysfs_dir, "usb%s", tmp);
 966                 free(tmp);
 967                 if (ret < 0)
 968                         return LIBUSB_ERROR_NO_MEM;
 969         }
 970
 971 retry:
 972         /* find the parent in the context */
 973         usbi_mutex_lock(&ctx->usb_devs_lock);
 974         list_for_each_entry(it, &ctx->usb_devs, list, struct libusb_device) {
 975                 struct linux_device_priv *priv = usbi_get_device_priv(it);
 976
 977                 if (priv->sysfs_dir) {
 978                         if (!strcmp(priv->sysfs_dir, parent_sysfs_dir)) {
 979                                 dev->parent_dev = libusb_ref_device(it);
 980                                 break;
 981                         }
 982                 }
 983         }
 984         usbi_mutex_unlock(&ctx->usb_devs_lock);
 985
 986         if (!dev->parent_dev && add_parent) {
 987                 usbi_dbg("parent_dev %s not enumerated yet, enumerating now",
 988                          parent_sysfs_dir);
 989                 sysfs_scan_device(ctx, parent_sysfs_dir);
 990                 add_parent = 0;
 991                 goto retry;
 992         }
 993
 994         usbi_dbg("dev %p (%s) has parent %p (%s) port %u", dev, sysfs_dir,
 995                  dev->parent_dev, parent_sysfs_dir, dev->port_number);
 996
 997         free(parent_sysfs_dir);
 998
 999         return LIBUSB_SUCCESS;
1000 }
1001
1002 int linux_enumerate_device(struct libusb_context *ctx,
1003         uint8_t busnum, uint8_t devaddr, const char *sysfs_dir)
1004 {
1005         unsigned long session_id;
1006         struct libusb_device *dev;
1007         int r;
1008
1009         /* FIXME: session ID is not guaranteed unique as addresses can wrap and
1010          * will be reused. instead we should add a simple sysfs attribute with
1011          * a session ID. */
1012         session_id = busnum << 8 | devaddr;
1013         usbi_dbg("busnum %u devaddr %u session_id %lu", busnum, devaddr, session_id);
1014
1015         dev = usbi_get_device_by_session_id(ctx, session_id);
1016         if (dev) {
1017                 /* device already exists in the context */
1018                 usbi_dbg("session_id %lu already exists", session_id);
1019                 libusb_unref_device(dev);
1020                 return LIBUSB_SUCCESS;
1021         }
1022
1023         usbi_dbg("allocating new device for %u/%u (session %lu)",
1024                  busnum, devaddr, session_id);
1025         dev = usbi_alloc_device(ctx, session_id);
1026         if (!dev)
1027                 return LIBUSB_ERROR_NO_MEM;
1028
1029         r = initialize_device(dev, busnum, devaddr, sysfs_dir, -1);
1030         if (r < 0)
1031                 goto out;
1032         r = usbi_sanitize_device(dev);
1033         if (r < 0)
1034                 goto out;
1035
1036         r = linux_get_parent_info(dev, sysfs_dir);
1037         if (r < 0)
1038                 goto out;
1039 out:
1040         if (r < 0)
1041                 libusb_unref_device(dev);
1042         else
1043                 usbi_connect_device(dev);
1044
1045         return r;
1046 }
1047
1048 void linux_hotplug_enumerate(uint8_t busnum, uint8_t devaddr, const char *sys_name)
1049 {
1050         struct libusb_context *ctx;
1051
1052         usbi_mutex_static_lock(&active_contexts_lock);
1053         list_for_each_entry(ctx, &active_contexts_list, list, struct libusb_context) {
1054                 linux_enumerate_device(ctx, busnum, devaddr, sys_name);
1055         }
1056         usbi_mutex_static_unlock(&active_contexts_lock);
1057 }
1058
1059 void linux_device_disconnected(uint8_t busnum, uint8_t devaddr)
1060 {
1061         struct libusb_context *ctx;
1062         struct libusb_device *dev;
1063         unsigned long session_id = busnum << 8 | devaddr;
1064
1065         usbi_mutex_static_lock(&active_contexts_lock);
1066         list_for_each_entry(ctx, &active_contexts_list, list, struct libusb_context) {
1067                 dev = usbi_get_device_by_session_id (ctx, session_id);
1068                 if (dev) {
1069                         usbi_disconnect_device(dev);
1070                         libusb_unref_device(dev);
1071                 } else {
1072                         usbi_dbg("device not found for session %lx", session_id);
1073                 }
1074         }
1075         usbi_mutex_static_unlock(&active_contexts_lock);
1076 }
1077
1078 #if !defined(HAVE_LIBUDEV)
1079 static int parse_u8(const char *str, uint8_t *val_p)
1080 {
1081         char *endptr;
1082         long num;
1083
1084         errno = 0;
1085         num = strtol(str, &endptr, 10);
1086         if (num < 0 || num > UINT8_MAX || errno)
1087                 return 0;
1088         if (endptr == str || *endptr != '\0')
1089                 return 0;
1090
1091         *val_p = (uint8_t)num;
1092         return 1;
1093 }
1094
1095 /* open a bus directory and adds all discovered devices to the context */
1096 static int usbfs_scan_busdir(struct libusb_context *ctx, uint8_t busnum)
1097 {
1098         DIR *dir;
1099         char dirpath[20];
1100         struct dirent *entry;
1101         int r = LIBUSB_ERROR_IO;
1102
1103         sprintf(dirpath, USB_DEVTMPFS_PATH "/%03u", busnum);
1104         usbi_dbg("%s", dirpath);
1105         dir = opendir(dirpath);
1106         if (!dir) {
1107                 usbi_err(ctx, "opendir '%s' failed, errno=%d", dirpath, errno);
1108                 /* FIXME: should handle valid race conditions like hub unplugged
1109                  * during directory iteration - this is not an error */
1110                 return r;
1111         }
1112
1113         while ((entry = readdir(dir))) {
1114                 uint8_t devaddr;
1115
1116                 if (entry->d_name[0] == '.')
1117                         continue;
1118
1119                 if (!parse_u8(entry->d_name, &devaddr)) {
1120                         usbi_dbg("unknown dir entry %s", entry->d_name);
1121                         continue;
1122                 }
1123
1124                 if (linux_enumerate_device(ctx, busnum, devaddr, NULL)) {
1125                         usbi_dbg("failed to enumerate dir entry %s", entry->d_name);
1126                         continue;
1127                 }
1128
1129                 r = 0;
1130         }
1131
1132         closedir(dir);
1133         return r;
1134 }
1135
1136 static int usbfs_get_device_list(struct libusb_context *ctx)
1137 {
1138         struct dirent *entry;
1139         DIR *buses;
1140         uint8_t busnum, devaddr;
1141         int r = 0;
1142
1143         if (usbdev_names)
1144                 buses = opendir(USBDEV_PATH);
1145         else
1146                 buses = opendir(USB_DEVTMPFS_PATH);
1147
1148         if (!buses) {
1149                 usbi_err(ctx, "opendir buses failed, errno=%d", errno);
1150                 return LIBUSB_ERROR_IO;
1151         }
1152
1153         while ((entry = readdir(buses))) {
1154                 if (entry->d_name[0] == '.')
1155                         continue;
1156
1157                 if (usbdev_names) {
1158                         if (!is_usbdev_entry(entry->d_name, &busnum, &devaddr))
1159                                 continue;
1160
1161                         r = linux_enumerate_device(ctx, busnum, devaddr, NULL);
1162                         if (r < 0) {
1163                                 usbi_dbg("failed to enumerate dir entry %s", entry->d_name);
1164                                 continue;
1165                         }
1166                 } else {
1167                         if (!parse_u8(entry->d_name, &busnum)) {
1168                                 usbi_dbg("unknown dir entry %s", entry->d_name);
1169                                 continue;
1170                         }
1171
1172                         r = usbfs_scan_busdir(ctx, busnum);
1173                         if (r < 0)
1174                                 break;
1175                 }
1176         }
1177
1178         closedir(buses);
1179         return r;
1180
1181 }
1182
1183 static int sysfs_get_device_list(struct libusb_context *ctx)
1184 {
1185         DIR *devices = opendir(SYSFS_DEVICE_PATH);
1186         struct dirent *entry;
1187         int num_devices = 0;
1188         int num_enumerated = 0;
1189
1190         if (!devices) {
1191                 usbi_err(ctx, "opendir devices failed, errno=%d", errno);
1192                 return LIBUSB_ERROR_IO;
1193         }
1194
1195         while ((entry = readdir(devices))) {
1196                 if ((!isdigit(entry->d_name[0]) && strncmp(entry->d_name, "usb", 3))
1197                     || strchr(entry->d_name, ':'))
1198                         continue;
1199
1200                 num_devices++;
1201
1202                 if (sysfs_scan_device(ctx, entry->d_name)) {
1203                         usbi_dbg("failed to enumerate dir entry %s", entry->d_name);
1204                         continue;
1205                 }
1206
1207                 num_enumerated++;
1208         }
1209
1210         closedir(devices);
1211
1212         /* successful if at least one device was enumerated or no devices were found */
1213         if (num_enumerated || !num_devices)
1214                 return LIBUSB_SUCCESS;
1215         else
1216                 return LIBUSB_ERROR_IO;
1217 }
1218
1219 static int linux_default_scan_devices(struct libusb_context *ctx)
1220 {
1221         /* we can retrieve device list and descriptors from sysfs or usbfs.
1222          * sysfs is preferable, because if we use usbfs we end up resuming
1223          * any autosuspended USB devices. however, sysfs is not available
1224          * everywhere, so we need a usbfs fallback too.
1225          */
1226         if (sysfs_available)
1227                 return sysfs_get_device_list(ctx);
1228         else
1229                 return usbfs_get_device_list(ctx);
1230 }
1231 #endif
1232
1233 static int initialize_handle(struct libusb_device_handle *handle, int fd)
1234 {
1235         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1236         int r;
1237
1238         hpriv->fd = fd;
1239
1240         r = ioctl(fd, IOCTL_USBFS_GET_CAPABILITIES, &hpriv->caps);
1241         if (r < 0) {
1242                 if (errno == ENOTTY)
1243                         usbi_dbg("getcap not available");
1244                 else
1245                         usbi_err(HANDLE_CTX(handle), "getcap failed, errno=%d", errno);
1246                 hpriv->caps = USBFS_CAP_BULK_CONTINUATION;
1247         }
1248
1249         return usbi_add_pollfd(HANDLE_CTX(handle), hpriv->fd, POLLOUT);
1250 }
1251
1252 static int op_wrap_sys_device(struct libusb_context *ctx,
1253         struct libusb_device_handle *handle, intptr_t sys_dev)
1254 {
1255         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1256         int fd = (int)sys_dev;
1257         uint8_t busnum, devaddr;
1258         struct usbfs_connectinfo ci;
1259         struct libusb_device *dev;
1260         int r;
1261
1262         r = linux_get_device_address(ctx, 1, &busnum, &devaddr, NULL, NULL, fd);
1263         if (r < 0) {
1264                 r = ioctl(fd, IOCTL_USBFS_CONNECTINFO, &ci);
1265                 if (r < 0) {
1266                         usbi_err(ctx, "connectinfo failed, errno=%d", errno);
1267                         return LIBUSB_ERROR_IO;
1268                 }
1269                 /* There is no ioctl to get the bus number. We choose 0 here
1270                  * as linux starts numbering buses from 1. */
1271                 busnum = 0;
1272                 devaddr = ci.devnum;
1273         }
1274
1275         /* Session id is unused as we do not add the device to the list of
1276          * connected devices. */
1277         usbi_dbg("allocating new device for fd %d", fd);
1278         dev = usbi_alloc_device(ctx, 0);
1279         if (!dev)
1280                 return LIBUSB_ERROR_NO_MEM;
1281
1282         r = initialize_device(dev, busnum, devaddr, NULL, fd);
1283         if (r < 0)
1284                 goto out;
1285         r = usbi_sanitize_device(dev);
1286         if (r < 0)
1287                 goto out;
1288         /* Consider the device as connected, but do not add it to the managed
1289          * device list. */
1290         dev->attached = 1;
1291         handle->dev = dev;
1292
1293         r = initialize_handle(handle, fd);
1294         hpriv->fd_keep = 1;
1295
1296 out:
1297         if (r < 0)
1298                 libusb_unref_device(dev);
1299         return r;
1300 }
1301
1302 static int op_open(struct libusb_device_handle *handle)
1303 {
1304         int fd, r;
1305
1306         fd = get_usbfs_fd(handle->dev, O_RDWR, 0);
1307         if (fd < 0) {
1308                 if (fd == LIBUSB_ERROR_NO_DEVICE) {
1309                         /* device will still be marked as attached if hotplug monitor thread
1310                          * hasn't processed remove event yet */
1311                         usbi_mutex_static_lock(&linux_hotplug_lock);
1312                         if (handle->dev->attached) {
1313                                 usbi_dbg("open failed with no device, but device still attached");
1314                                 linux_device_disconnected(handle->dev->bus_number,
1315                                                           handle->dev->device_address);
1316                         }
1317                         usbi_mutex_static_unlock(&linux_hotplug_lock);
1318                 }
1319                 return fd;
1320         }
1321
1322         r = initialize_handle(handle, fd);
1323         if (r < 0)
1324                 close(fd);
1325
1326         return r;
1327 }
1328
1329 static void op_close(struct libusb_device_handle *dev_handle)
1330 {
1331         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(dev_handle);
1332
1333         /* fd may have already been removed by POLLERR condition in op_handle_events() */
1334         if (!hpriv->fd_removed)
1335                 usbi_remove_pollfd(HANDLE_CTX(dev_handle), hpriv->fd);
1336         if (!hpriv->fd_keep)
1337                 close(hpriv->fd);
1338 }
1339
1340 static int op_get_configuration(struct libusb_device_handle *handle,
1341         int *config)
1342 {
1343         struct linux_device_priv *priv = usbi_get_device_priv(handle->dev);
1344         int r;
1345
1346         if (priv->sysfs_dir) {
1347                 r = sysfs_get_active_config(handle->dev, config);
1348         } else {
1349                 struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1350
1351                 r = usbfs_get_active_config(handle->dev, hpriv->fd);
1352                 if (r == LIBUSB_SUCCESS)
1353                         *config = priv->active_config;
1354         }
1355         if (r < 0)
1356                 return r;
1357
1358         if (*config == -1) {
1359                 usbi_err(HANDLE_CTX(handle), "device unconfigured");
1360                 *config = 0;
1361         }
1362
1363         return 0;
1364 }
1365
1366 static int op_set_configuration(struct libusb_device_handle *handle, int config)
1367 {
1368         struct linux_device_priv *priv = usbi_get_device_priv(handle->dev);
1369         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1370         int fd = hpriv->fd;
1371         int r = ioctl(fd, IOCTL_USBFS_SETCONFIGURATION, &config);
1372
1373         if (r < 0) {
1374                 if (errno == EINVAL)
1375                         return LIBUSB_ERROR_NOT_FOUND;
1376                 else if (errno == EBUSY)
1377                         return LIBUSB_ERROR_BUSY;
1378                 else if (errno == ENODEV)
1379                         return LIBUSB_ERROR_NO_DEVICE;
1380
1381                 usbi_err(HANDLE_CTX(handle), "set configuration failed, errno=%d", errno);
1382                 return LIBUSB_ERROR_OTHER;
1383         }
1384
1385         /* update our cached active config descriptor */
1386         priv->active_config = config;
1387
1388         return LIBUSB_SUCCESS;
1389 }
1390
1391 static int claim_interface(struct libusb_device_handle *handle, int iface)
1392 {
1393         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1394         int fd = hpriv->fd;
1395         int r = ioctl(fd, IOCTL_USBFS_CLAIMINTERFACE, &iface);
1396
1397         if (r < 0) {
1398                 if (errno == ENOENT)
1399                         return LIBUSB_ERROR_NOT_FOUND;
1400                 else if (errno == EBUSY)
1401                         return LIBUSB_ERROR_BUSY;
1402                 else if (errno == ENODEV)
1403                         return LIBUSB_ERROR_NO_DEVICE;
1404
1405                 usbi_err(HANDLE_CTX(handle), "claim interface failed, errno=%d", errno);
1406                 return LIBUSB_ERROR_OTHER;
1407         }
1408         return 0;
1409 }
1410
1411 static int release_interface(struct libusb_device_handle *handle, int iface)
1412 {
1413         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1414         int fd = hpriv->fd;
1415         int r = ioctl(fd, IOCTL_USBFS_RELEASEINTERFACE, &iface);
1416
1417         if (r < 0) {
1418                 if (errno == ENODEV)
1419                         return LIBUSB_ERROR_NO_DEVICE;
1420
1421                 usbi_err(HANDLE_CTX(handle), "release interface failed, errno=%d", errno);
1422                 return LIBUSB_ERROR_OTHER;
1423         }
1424         return 0;
1425 }
1426
1427 static int op_set_interface(struct libusb_device_handle *handle, int iface,
1428         int altsetting)
1429 {
1430         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1431         int fd = hpriv->fd;
1432         struct usbfs_setinterface setintf;
1433         int r;
1434
1435         setintf.interface = iface;
1436         setintf.altsetting = altsetting;
1437         r = ioctl(fd, IOCTL_USBFS_SETINTERFACE, &setintf);
1438         if (r < 0) {
1439                 if (errno == EINVAL)
1440                         return LIBUSB_ERROR_NOT_FOUND;
1441                 else if (errno == ENODEV)
1442                         return LIBUSB_ERROR_NO_DEVICE;
1443
1444                 usbi_err(HANDLE_CTX(handle), "set interface failed, errno=%d", errno);
1445                 return LIBUSB_ERROR_OTHER;
1446         }
1447
1448         return 0;
1449 }
1450
1451 static int op_clear_halt(struct libusb_device_handle *handle,
1452         unsigned char endpoint)
1453 {
1454         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1455         int fd = hpriv->fd;
1456         unsigned int _endpoint = endpoint;
1457         int r = ioctl(fd, IOCTL_USBFS_CLEAR_HALT, &_endpoint);
1458
1459         if (r < 0) {
1460                 if (errno == ENOENT)
1461                         return LIBUSB_ERROR_NOT_FOUND;
1462                 else if (errno == ENODEV)
1463                         return LIBUSB_ERROR_NO_DEVICE;
1464
1465                 usbi_err(HANDLE_CTX(handle), "clear halt failed, errno=%d", errno);
1466                 return LIBUSB_ERROR_OTHER;
1467         }
1468
1469         return 0;
1470 }
1471
1472 static int op_reset_device(struct libusb_device_handle *handle)
1473 {
1474         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1475         int fd = hpriv->fd;
1476         int i, r, ret = 0;
1477
1478         /* Doing a device reset will cause the usbfs driver to get unbound
1479          * from any interfaces it is bound to. By voluntarily unbinding
1480          * the usbfs driver ourself, we stop the kernel from rebinding
1481          * the interface after reset (which would end up with the interface
1482          * getting bound to the in kernel driver if any). */
1483         for (i = 0; i < USB_MAXINTERFACES; i++) {
1484                 if (handle->claimed_interfaces & (1UL << i))
1485                         release_interface(handle, i);
1486         }
1487
1488         usbi_mutex_lock(&handle->lock);
1489         r = ioctl(fd, IOCTL_USBFS_RESET, NULL);
1490         if (r < 0) {
1491                 if (errno == ENODEV) {
1492                         ret = LIBUSB_ERROR_NOT_FOUND;
1493                         goto out;
1494                 }
1495
1496                 usbi_err(HANDLE_CTX(handle), "reset failed, errno=%d", errno);
1497                 ret = LIBUSB_ERROR_OTHER;
1498                 goto out;
1499         }
1500
1501         /* And re-claim any interfaces which were claimed before the reset */
1502         for (i = 0; i < USB_MAXINTERFACES; i++) {
1503                 if (!(handle->claimed_interfaces & (1UL << i)))
1504                         continue;
1505                 /*
1506                  * A driver may have completed modprobing during
1507                  * IOCTL_USBFS_RESET, and bound itself as soon as
1508                  * IOCTL_USBFS_RESET released the device lock
1509                  */
1510                 r = detach_kernel_driver_and_claim(handle, i);
1511                 if (r) {
1512                         usbi_warn(HANDLE_CTX(handle), "failed to re-claim interface %d after reset: %s",
1513                                   i, libusb_error_name(r));
1514                         handle->claimed_interfaces &= ~(1UL << i);
1515                         ret = LIBUSB_ERROR_NOT_FOUND;
1516                 }
1517         }
1518 out:
1519         usbi_mutex_unlock(&handle->lock);
1520         return ret;
1521 }
1522
1523 static int do_streams_ioctl(struct libusb_device_handle *handle, long req,
1524         uint32_t num_streams, unsigned char *endpoints, int num_endpoints)
1525 {
1526         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1527         int r, fd = hpriv->fd;
1528         struct usbfs_streams *streams;
1529
1530         if (num_endpoints > 30) /* Max 15 in + 15 out eps */
1531                 return LIBUSB_ERROR_INVALID_PARAM;
1532
1533         streams = malloc(sizeof(*streams) + num_endpoints);
1534         if (!streams)
1535                 return LIBUSB_ERROR_NO_MEM;
1536
1537         streams->num_streams = num_streams;
1538         streams->num_eps = num_endpoints;
1539         memcpy(streams->eps, endpoints, num_endpoints);
1540
1541         r = ioctl(fd, req, streams);
1542
1543         free(streams);
1544
1545         if (r < 0) {
1546                 if (errno == ENOTTY)
1547                         return LIBUSB_ERROR_NOT_SUPPORTED;
1548                 else if (errno == EINVAL)
1549                         return LIBUSB_ERROR_INVALID_PARAM;
1550                 else if (errno == ENODEV)
1551                         return LIBUSB_ERROR_NO_DEVICE;
1552
1553                 usbi_err(HANDLE_CTX(handle), "streams-ioctl failed, errno=%d", errno);
1554                 return LIBUSB_ERROR_OTHER;
1555         }
1556         return r;
1557 }
1558
1559 static int op_alloc_streams(struct libusb_device_handle *handle,
1560         uint32_t num_streams, unsigned char *endpoints, int num_endpoints)
1561 {
1562         return do_streams_ioctl(handle, IOCTL_USBFS_ALLOC_STREAMS,
1563                                 num_streams, endpoints, num_endpoints);
1564 }
1565
1566 static int op_free_streams(struct libusb_device_handle *handle,
1567                 unsigned char *endpoints, int num_endpoints)
1568 {
1569         return do_streams_ioctl(handle, IOCTL_USBFS_FREE_STREAMS, 0,
1570                                 endpoints, num_endpoints);
1571 }
1572
1573 static unsigned char *op_dev_mem_alloc(struct libusb_device_handle *handle,
1574         size_t len)
1575 {
1576         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1577         unsigned char *buffer;
1578
1579         buffer = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, hpriv->fd, 0);
1580         if (buffer == MAP_FAILED) {
1581                 usbi_err(HANDLE_CTX(handle), "alloc dev mem failed, errno=%d", errno);
1582                 return NULL;
1583         }
1584         return buffer;
1585 }
1586
1587 static int op_dev_mem_free(struct libusb_device_handle *handle,
1588         unsigned char *buffer, size_t len)
1589 {
1590         if (munmap(buffer, len) != 0) {
1591                 usbi_err(HANDLE_CTX(handle), "free dev mem failed, errno=%d", errno);
1592                 return LIBUSB_ERROR_OTHER;
1593         } else {
1594                 return LIBUSB_SUCCESS;
1595         }
1596 }
1597
1598 static int op_kernel_driver_active(struct libusb_device_handle *handle,
1599         int interface)
1600 {
1601         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1602         int fd = hpriv->fd;
1603         struct usbfs_getdriver getdrv;
1604         int r;
1605
1606         getdrv.interface = interface;
1607         r = ioctl(fd, IOCTL_USBFS_GETDRIVER, &getdrv);
1608         if (r < 0) {
1609                 if (errno == ENODATA)
1610                         return 0;
1611                 else if (errno == ENODEV)
1612                         return LIBUSB_ERROR_NO_DEVICE;
1613
1614                 usbi_err(HANDLE_CTX(handle), "get driver failed, errno=%d", errno);
1615                 return LIBUSB_ERROR_OTHER;
1616         }
1617
1618         return strcmp(getdrv.driver, "usbfs") != 0;
1619 }
1620
1621 static int op_detach_kernel_driver(struct libusb_device_handle *handle,
1622         int interface)
1623 {
1624         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1625         int fd = hpriv->fd;
1626         struct usbfs_ioctl command;
1627         struct usbfs_getdriver getdrv;
1628         int r;
1629
1630         command.ifno = interface;
1631         command.ioctl_code = IOCTL_USBFS_DISCONNECT;
1632         command.data = NULL;
1633
1634         getdrv.interface = interface;
1635         r = ioctl(fd, IOCTL_USBFS_GETDRIVER, &getdrv);
1636         if (r == 0 && !strcmp(getdrv.driver, "usbfs"))
1637                 return LIBUSB_ERROR_NOT_FOUND;
1638
1639         r = ioctl(fd, IOCTL_USBFS_IOCTL, &command);
1640         if (r < 0) {
1641                 if (errno == ENODATA)
1642                         return LIBUSB_ERROR_NOT_FOUND;
1643                 else if (errno == EINVAL)
1644                         return LIBUSB_ERROR_INVALID_PARAM;
1645                 else if (errno == ENODEV)
1646                         return LIBUSB_ERROR_NO_DEVICE;
1647
1648                 usbi_err(HANDLE_CTX(handle), "detach failed, errno=%d", errno);
1649                 return LIBUSB_ERROR_OTHER;
1650         }
1651
1652         return 0;
1653 }
1654
1655 static int op_attach_kernel_driver(struct libusb_device_handle *handle,
1656         int interface)
1657 {
1658         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1659         int fd = hpriv->fd;
1660         struct usbfs_ioctl command;
1661         int r;
1662
1663         command.ifno = interface;
1664         command.ioctl_code = IOCTL_USBFS_CONNECT;
1665         command.data = NULL;
1666
1667         r = ioctl(fd, IOCTL_USBFS_IOCTL, &command);
1668         if (r < 0) {
1669                 if (errno == ENODATA)
1670                         return LIBUSB_ERROR_NOT_FOUND;
1671                 else if (errno == EINVAL)
1672                         return LIBUSB_ERROR_INVALID_PARAM;
1673                 else if (errno == ENODEV)
1674                         return LIBUSB_ERROR_NO_DEVICE;
1675                 else if (errno == EBUSY)
1676                         return LIBUSB_ERROR_BUSY;
1677
1678                 usbi_err(HANDLE_CTX(handle), "attach failed, errno=%d", errno);
1679                 return LIBUSB_ERROR_OTHER;
1680         } else if (r == 0) {
1681                 return LIBUSB_ERROR_NOT_FOUND;
1682         }
1683
1684         return 0;
1685 }
1686
1687 static int detach_kernel_driver_and_claim(struct libusb_device_handle *handle,
1688         int interface)
1689 {
1690         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
1691         struct usbfs_disconnect_claim dc;
1692         int r, fd = hpriv->fd;
1693
1694         dc.interface = interface;
1695         strcpy(dc.driver, "usbfs");
1696         dc.flags = USBFS_DISCONNECT_CLAIM_EXCEPT_DRIVER;
1697         r = ioctl(fd, IOCTL_USBFS_DISCONNECT_CLAIM, &dc);
1698         if (r == 0)
1699                 return 0;
1700         switch (errno) {
1701         case ENOTTY:
1702                 break;
1703         case EBUSY:
1704                 return LIBUSB_ERROR_BUSY;
1705         case EINVAL:
1706                 return LIBUSB_ERROR_INVALID_PARAM;
1707         case ENODEV:
1708                 return LIBUSB_ERROR_NO_DEVICE;
1709         default:
1710                 usbi_err(HANDLE_CTX(handle), "disconnect-and-claim failed, errno=%d", errno);
1711                 return LIBUSB_ERROR_OTHER;
1712         }
1713
1714         /* Fallback code for kernels which don't support the
1715            disconnect-and-claim ioctl */
1716         r = op_detach_kernel_driver(handle, interface);
1717         if (r != 0 && r != LIBUSB_ERROR_NOT_FOUND)
1718                 return r;
1719
1720         return claim_interface(handle, interface);
1721 }
1722
1723 static int op_claim_interface(struct libusb_device_handle *handle, int iface)
1724 {
1725         if (handle->auto_detach_kernel_driver)
1726                 return detach_kernel_driver_and_claim(handle, iface);
1727         else
1728                 return claim_interface(handle, iface);
1729 }
1730
1731 static int op_release_interface(struct libusb_device_handle *handle, int iface)
1732 {
1733         int r;
1734
1735         r = release_interface(handle, iface);
1736         if (r)
1737                 return r;
1738
1739         if (handle->auto_detach_kernel_driver)
1740                 op_attach_kernel_driver(handle, iface);
1741
1742         return 0;
1743 }
1744
1745 static void op_destroy_device(struct libusb_device *dev)
1746 {
1747         struct linux_device_priv *priv = usbi_get_device_priv(dev);
1748
1749         free(priv->descriptors);
1750         free(priv->sysfs_dir);
1751 }
1752
1753 /* URBs are discarded in reverse order of submission to avoid races. */
1754 static int discard_urbs(struct usbi_transfer *itransfer, int first, int last_plus_one)
1755 {
1756         struct libusb_transfer *transfer =
1757                 USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
1758         struct linux_transfer_priv *tpriv = usbi_get_transfer_priv(itransfer);
1759         struct linux_device_handle_priv *hpriv =
1760                 usbi_get_device_handle_priv(transfer->dev_handle);
1761         int i, ret = 0;
1762         struct usbfs_urb *urb;
1763
1764         for (i = last_plus_one - 1; i >= first; i--) {
1765                 if (transfer->type == LIBUSB_TRANSFER_TYPE_ISOCHRONOUS)
1766                         urb = tpriv->iso_urbs[i];
1767                 else
1768                         urb = &tpriv->urbs[i];
1769
1770                 if (ioctl(hpriv->fd, IOCTL_USBFS_DISCARDURB, urb) == 0)
1771                         continue;
1772
1773                 if (errno == EINVAL) {
1774                         usbi_dbg("URB not found --> assuming ready to be reaped");
1775                         if (i == (last_plus_one - 1))
1776                                 ret = LIBUSB_ERROR_NOT_FOUND;
1777                 } else if (errno == ENODEV) {
1778                         usbi_dbg("Device not found for URB --> assuming ready to be reaped");
1779                         ret = LIBUSB_ERROR_NO_DEVICE;
1780                 } else {
1781                         usbi_warn(TRANSFER_CTX(transfer), "unrecognised discard errno %d", errno);
1782                         ret = LIBUSB_ERROR_OTHER;
1783                 }
1784         }
1785         return ret;
1786 }
1787
1788 static void free_iso_urbs(struct linux_transfer_priv *tpriv)
1789 {
1790         int i;
1791
1792         for (i = 0; i < tpriv->num_urbs; i++) {
1793                 struct usbfs_urb *urb = tpriv->iso_urbs[i];
1794
1795                 if (!urb)
1796                         break;
1797                 free(urb);
1798         }
1799
1800         free(tpriv->iso_urbs);
1801         tpriv->iso_urbs = NULL;
1802 }
1803
1804 static int submit_bulk_transfer(struct usbi_transfer *itransfer)
1805 {
1806         struct libusb_transfer *transfer =
1807                 USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
1808         struct linux_transfer_priv *tpriv = usbi_get_transfer_priv(itransfer);
1809         struct linux_device_handle_priv *hpriv =
1810                 usbi_get_device_handle_priv(transfer->dev_handle);
1811         struct usbfs_urb *urbs;
1812         int is_out = IS_XFEROUT(transfer);
1813         int bulk_buffer_len, use_bulk_continuation;
1814         int num_urbs;
1815         int last_urb_partial = 0;
1816         int r;
1817         int i;
1818
1819         /*
1820          * Older versions of usbfs place a 16kb limit on bulk URBs. We work
1821          * around this by splitting large transfers into 16k blocks, and then
1822          * submit all urbs at once. it would be simpler to submit one urb at
1823          * a time, but there is a big performance gain doing it this way.
1824          *
1825          * Newer versions lift the 16k limit (USBFS_CAP_NO_PACKET_SIZE_LIM),
1826          * using arbritary large transfers can still be a bad idea though, as
1827          * the kernel needs to allocate physical contiguous memory for this,
1828          * which may fail for large buffers.
1829          *
1830          * The kernel solves this problem by splitting the transfer into
1831          * blocks itself when the host-controller is scatter-gather capable
1832          * (USBFS_CAP_BULK_SCATTER_GATHER), which most controllers are.
1833          *
1834          * Last, there is the issue of short-transfers when splitting, for
1835          * short split-transfers to work reliable USBFS_CAP_BULK_CONTINUATION
1836          * is needed, but this is not always available.
1837          */
1838         if (hpriv->caps & USBFS_CAP_BULK_SCATTER_GATHER) {
1839                 /* Good! Just submit everything in one go */
1840                 bulk_buffer_len = transfer->length ? transfer->length : 1;
1841                 use_bulk_continuation = 0;
1842         } else if (hpriv->caps & USBFS_CAP_BULK_CONTINUATION) {
1843                 /* Split the transfers and use bulk-continuation to
1844                    avoid issues with short-transfers */
1845                 bulk_buffer_len = MAX_BULK_BUFFER_LENGTH;
1846                 use_bulk_continuation = 1;
1847         } else if (hpriv->caps & USBFS_CAP_NO_PACKET_SIZE_LIM) {
1848                 /* Don't split, assume the kernel can alloc the buffer
1849                    (otherwise the submit will fail with -ENOMEM) */
1850                 bulk_buffer_len = transfer->length ? transfer->length : 1;
1851                 use_bulk_continuation = 0;
1852         } else {
1853                 /* Bad, splitting without bulk-continuation, short transfers
1854                    which end before the last urb will not work reliable! */
1855                 /* Note we don't warn here as this is "normal" on kernels <
1856                    2.6.32 and not a problem for most applications */
1857                 bulk_buffer_len = MAX_BULK_BUFFER_LENGTH;
1858                 use_bulk_continuation = 0;
1859         }
1860
1861         num_urbs = transfer->length / bulk_buffer_len;
1862
1863         if (transfer->length == 0) {
1864                 num_urbs = 1;
1865         } else if ((transfer->length % bulk_buffer_len) > 0) {
1866                 last_urb_partial = 1;
1867                 num_urbs++;
1868         }
1869         usbi_dbg("need %d urbs for new transfer with length %d", num_urbs, transfer->length);
1870         urbs = calloc(num_urbs, sizeof(*urbs));
1871         if (!urbs)
1872                 return LIBUSB_ERROR_NO_MEM;
1873         tpriv->urbs = urbs;
1874         tpriv->num_urbs = num_urbs;
1875         tpriv->num_retired = 0;
1876         tpriv->reap_action = NORMAL;
1877         tpriv->reap_status = LIBUSB_TRANSFER_COMPLETED;
1878
1879         for (i = 0; i < num_urbs; i++) {
1880                 struct usbfs_urb *urb = &urbs[i];
1881
1882                 urb->usercontext = itransfer;
1883                 switch (transfer->type) {
1884                 case LIBUSB_TRANSFER_TYPE_BULK:
1885                         urb->type = USBFS_URB_TYPE_BULK;
1886                         urb->stream_id = 0;
1887                         break;
1888                 case LIBUSB_TRANSFER_TYPE_BULK_STREAM:
1889                         urb->type = USBFS_URB_TYPE_BULK;
1890                         urb->stream_id = itransfer->stream_id;
1891                         break;
1892                 case LIBUSB_TRANSFER_TYPE_INTERRUPT:
1893                         urb->type = USBFS_URB_TYPE_INTERRUPT;
1894                         break;
1895                 }
1896                 urb->endpoint = transfer->endpoint;
1897                 urb->buffer = transfer->buffer + (i * bulk_buffer_len);
1898
1899                 /* don't set the short not ok flag for the last URB */
1900                 if (use_bulk_continuation && !is_out && (i < num_urbs - 1))
1901                         urb->flags = USBFS_URB_SHORT_NOT_OK;
1902
1903                 if (i == num_urbs - 1 && last_urb_partial)
1904                         urb->buffer_length = transfer->length % bulk_buffer_len;
1905                 else if (transfer->length == 0)
1906                         urb->buffer_length = 0;
1907                 else
1908                         urb->buffer_length = bulk_buffer_len;
1909
1910                 if (i > 0 && use_bulk_continuation)
1911                         urb->flags |= USBFS_URB_BULK_CONTINUATION;
1912
1913                 /* we have already checked that the flag is supported */
1914                 if (is_out && i == num_urbs - 1 &&
1915                     (transfer->flags & LIBUSB_TRANSFER_ADD_ZERO_PACKET))
1916                         urb->flags |= USBFS_URB_ZERO_PACKET;
1917
1918                 r = ioctl(hpriv->fd, IOCTL_USBFS_SUBMITURB, urb);
1919                 if (r == 0)
1920                         continue;
1921
1922                 if (errno == ENODEV) {
1923                         r = LIBUSB_ERROR_NO_DEVICE;
1924                 } else if (errno == ENOMEM) {
1925                         r = LIBUSB_ERROR_NO_MEM;
1926                 } else {
1927                         usbi_err(TRANSFER_CTX(transfer), "submiturb failed, errno=%d", errno);
1928                         r = LIBUSB_ERROR_IO;
1929                 }
1930
1931                 /* if the first URB submission fails, we can simply free up and
1932                  * return failure immediately. */
1933                 if (i == 0) {
1934                         usbi_dbg("first URB failed, easy peasy");
1935                         free(urbs);
1936                         tpriv->urbs = NULL;
1937                         return r;
1938                 }
1939
1940                 /* if it's not the first URB that failed, the situation is a bit
1941                  * tricky. we may need to discard all previous URBs. there are
1942                  * complications:
1943                  *  - discarding is asynchronous - discarded urbs will be reaped
1944                  *    later. the user must not have freed the transfer when the
1945                  *    discarded URBs are reaped, otherwise libusb will be using
1946                  *    freed memory.
1947                  *  - the earlier URBs may have completed successfully and we do
1948                  *    not want to throw away any data.
1949                  *  - this URB failing may be no error; EREMOTEIO means that
1950                  *    this transfer simply didn't need all the URBs we submitted
1951                  * so, we report that the transfer was submitted successfully and
1952                  * in case of error we discard all previous URBs. later when
1953                  * the final reap completes we can report error to the user,
1954                  * or success if an earlier URB was completed successfully.
1955                  */
1956                 tpriv->reap_action = errno == EREMOTEIO ? COMPLETED_EARLY : SUBMIT_FAILED;
1957
1958                 /* The URBs we haven't submitted yet we count as already
1959                  * retired. */
1960                 tpriv->num_retired += num_urbs - i;
1961
1962                 /* If we completed short then don't try to discard. */
1963                 if (tpriv->reap_action == COMPLETED_EARLY)
1964                         return 0;
1965
1966                 discard_urbs(itransfer, 0, i);
1967
1968                 usbi_dbg("reporting successful submission but waiting for %d "
1969                          "discards before reporting error", i);
1970                 return 0;
1971         }
1972
1973         return 0;
1974 }
1975
1976 static int submit_iso_transfer(struct usbi_transfer *itransfer)
1977 {
1978         struct libusb_transfer *transfer =
1979                 USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
1980         struct linux_transfer_priv *tpriv = usbi_get_transfer_priv(itransfer);
1981         struct linux_device_handle_priv *hpriv =
1982                 usbi_get_device_handle_priv(transfer->dev_handle);
1983         struct usbfs_urb **urbs;
1984         int num_packets = transfer->num_iso_packets;
1985         int num_packets_remaining;
1986         int i, j;
1987         int num_urbs;
1988         unsigned int packet_len;
1989         unsigned int total_len = 0;
1990         unsigned char *urb_buffer = transfer->buffer;
1991
1992         if (num_packets < 1)
1993                 return LIBUSB_ERROR_INVALID_PARAM;
1994
1995         /* usbfs places arbitrary limits on iso URBs. this limit has changed
1996          * at least three times, but we attempt to detect this limit during
1997          * init and check it here. if the kernel rejects the request due to
1998          * its size, we return an error indicating such to the user.
1999          */
2000         for (i = 0; i < num_packets; i++) {
2001                 packet_len = transfer->iso_packet_desc[i].length;
2002
2003                 if (packet_len > max_iso_packet_len) {
2004                         usbi_warn(TRANSFER_CTX(transfer),
2005                                   "iso packet length of %u bytes exceeds maximum of %u bytes",
2006                                   packet_len, max_iso_packet_len);
2007                         return LIBUSB_ERROR_INVALID_PARAM;
2008                 }
2009
2010                 total_len += packet_len;
2011         }
2012
2013         if (transfer->length < (int)total_len)
2014                 return LIBUSB_ERROR_INVALID_PARAM;
2015
2016         /* usbfs limits the number of iso packets per URB */
2017         num_urbs = (num_packets + (MAX_ISO_PACKETS_PER_URB - 1)) / MAX_ISO_PACKETS_PER_URB;
2018
2019         usbi_dbg("need %d urbs for new transfer with length %d", num_urbs, transfer->length);
2020
2021         urbs = calloc(num_urbs, sizeof(*urbs));
2022         if (!urbs)
2023                 return LIBUSB_ERROR_NO_MEM;
2024
2025         tpriv->iso_urbs = urbs;
2026         tpriv->num_urbs = num_urbs;
2027         tpriv->num_retired = 0;
2028         tpriv->reap_action = NORMAL;
2029         tpriv->iso_packet_offset = 0;
2030
2031         /* allocate + initialize each URB with the correct number of packets */
2032         num_packets_remaining = num_packets;
2033         for (i = 0, j = 0; i < num_urbs; i++) {
2034                 int num_packets_in_urb = MIN(num_packets_remaining, MAX_ISO_PACKETS_PER_URB);
2035                 struct usbfs_urb *urb;
2036                 size_t alloc_size;
2037                 int k;
2038
2039                 alloc_size = sizeof(*urb)
2040                         + (num_packets_in_urb * sizeof(struct usbfs_iso_packet_desc));
2041                 urb = calloc(1, alloc_size);
2042                 if (!urb) {
2043                         free_iso_urbs(tpriv);
2044                         return LIBUSB_ERROR_NO_MEM;
2045                 }
2046                 urbs[i] = urb;
2047
2048                 /* populate packet lengths */
2049                 for (k = 0; k < num_packets_in_urb; j++, k++) {
2050                         packet_len = transfer->iso_packet_desc[j].length;
2051                         urb->buffer_length += packet_len;
2052                         urb->iso_frame_desc[k].length = packet_len;
2053                 }
2054
2055                 urb->usercontext = itransfer;
2056                 urb->type = USBFS_URB_TYPE_ISO;
2057                 /* FIXME: interface for non-ASAP data? */
2058                 urb->flags = USBFS_URB_ISO_ASAP;
2059                 urb->endpoint = transfer->endpoint;
2060                 urb->number_of_packets = num_packets_in_urb;
2061                 urb->buffer = urb_buffer;
2062
2063                 urb_buffer += urb->buffer_length;
2064                 num_packets_remaining -= num_packets_in_urb;
2065         }
2066
2067         /* submit URBs */
2068         for (i = 0; i < num_urbs; i++) {
2069                 int r = ioctl(hpriv->fd, IOCTL_USBFS_SUBMITURB, urbs[i]);
2070
2071                 if (r == 0)
2072                         continue;
2073
2074                 if (errno == ENODEV) {
2075                         r = LIBUSB_ERROR_NO_DEVICE;
2076                 } else if (errno == EINVAL) {
2077                         usbi_warn(TRANSFER_CTX(transfer), "submiturb failed, transfer too large");
2078                         r = LIBUSB_ERROR_INVALID_PARAM;
2079                 } else if (errno == EMSGSIZE) {
2080                         usbi_warn(TRANSFER_CTX(transfer), "submiturb failed, iso packet length too large");
2081                         r = LIBUSB_ERROR_INVALID_PARAM;
2082                 } else {
2083                         usbi_err(TRANSFER_CTX(transfer), "submiturb failed, errno=%d", errno);
2084                         r = LIBUSB_ERROR_IO;
2085                 }
2086
2087                 /* if the first URB submission fails, we can simply free up and
2088                  * return failure immediately. */
2089                 if (i == 0) {
2090                         usbi_dbg("first URB failed, easy peasy");
2091                         free_iso_urbs(tpriv);
2092                         return r;
2093                 }
2094
2095                 /* if it's not the first URB that failed, the situation is a bit
2096                  * tricky. we must discard all previous URBs. there are
2097                  * complications:
2098                  *  - discarding is asynchronous - discarded urbs will be reaped
2099                  *    later. the user must not have freed the transfer when the
2100                  *    discarded URBs are reaped, otherwise libusb will be using
2101                  *    freed memory.
2102                  *  - the earlier URBs may have completed successfully and we do
2103                  *    not want to throw away any data.
2104                  * so, in this case we discard all the previous URBs BUT we report
2105                  * that the transfer was submitted successfully. then later when
2106                  * the final discard completes we can report error to the user.
2107                  */
2108                 tpriv->reap_action = SUBMIT_FAILED;
2109
2110                 /* The URBs we haven't submitted yet we count as already
2111                  * retired. */
2112                 tpriv->num_retired = num_urbs - i;
2113                 discard_urbs(itransfer, 0, i);
2114
2115                 usbi_dbg("reporting successful submission but waiting for %d "
2116                          "discards before reporting error", i);
2117                 return 0;
2118         }
2119
2120         return 0;
2121 }
2122
2123 static int submit_control_transfer(struct usbi_transfer *itransfer)
2124 {
2125         struct linux_transfer_priv *tpriv = usbi_get_transfer_priv(itransfer);
2126         struct libusb_transfer *transfer =
2127                 USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
2128         struct linux_device_handle_priv *hpriv =
2129                 usbi_get_device_handle_priv(transfer->dev_handle);
2130         struct usbfs_urb *urb;
2131         int r;
2132
2133         if (transfer->length - LIBUSB_CONTROL_SETUP_SIZE > MAX_CTRL_BUFFER_LENGTH)
2134                 return LIBUSB_ERROR_INVALID_PARAM;
2135
2136         urb = calloc(1, sizeof(*urb));
2137         if (!urb)
2138                 return LIBUSB_ERROR_NO_MEM;
2139         tpriv->urbs = urb;
2140         tpriv->num_urbs = 1;
2141         tpriv->reap_action = NORMAL;
2142
2143         urb->usercontext = itransfer;
2144         urb->type = USBFS_URB_TYPE_CONTROL;
2145         urb->endpoint = transfer->endpoint;
2146         urb->buffer = transfer->buffer;
2147         urb->buffer_length = transfer->length;
2148
2149         r = ioctl(hpriv->fd, IOCTL_USBFS_SUBMITURB, urb);
2150         if (r < 0) {
2151                 free(urb);
2152                 tpriv->urbs = NULL;
2153                 if (errno == ENODEV)
2154                         return LIBUSB_ERROR_NO_DEVICE;
2155
2156                 usbi_err(TRANSFER_CTX(transfer), "submiturb failed, errno=%d", errno);
2157                 return LIBUSB_ERROR_IO;
2158         }
2159         return 0;
2160 }
2161
2162 static int op_submit_transfer(struct usbi_transfer *itransfer)
2163 {
2164         struct libusb_transfer *transfer =
2165                 USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
2166
2167         switch (transfer->type) {
2168         case LIBUSB_TRANSFER_TYPE_CONTROL:
2169                 return submit_control_transfer(itransfer);
2170         case LIBUSB_TRANSFER_TYPE_BULK:
2171         case LIBUSB_TRANSFER_TYPE_BULK_STREAM:
2172                 return submit_bulk_transfer(itransfer);
2173         case LIBUSB_TRANSFER_TYPE_INTERRUPT:
2174                 return submit_bulk_transfer(itransfer);
2175         case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
2176                 return submit_iso_transfer(itransfer);
2177         default:
2178                 usbi_err(TRANSFER_CTX(transfer), "unknown transfer type %u", transfer->type);
2179                 return LIBUSB_ERROR_INVALID_PARAM;
2180         }
2181 }
2182
2183 static int op_cancel_transfer(struct usbi_transfer *itransfer)
2184 {
2185         struct linux_transfer_priv *tpriv = usbi_get_transfer_priv(itransfer);
2186         struct libusb_transfer *transfer =
2187                 USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
2188         int r;
2189
2190         if (!tpriv->urbs)
2191                 return LIBUSB_ERROR_NOT_FOUND;
2192
2193         r = discard_urbs(itransfer, 0, tpriv->num_urbs);
2194         if (r != 0)
2195                 return r;
2196
2197         switch (transfer->type) {
2198         case LIBUSB_TRANSFER_TYPE_BULK:
2199         case LIBUSB_TRANSFER_TYPE_BULK_STREAM:
2200                 if (tpriv->reap_action == ERROR)
2201                         break;
2202                 /* else, fall through */
2203         default:
2204                 tpriv->reap_action = CANCELLED;
2205         }
2206
2207         return 0;
2208 }
2209
2210 static void op_clear_transfer_priv(struct usbi_transfer *itransfer)
2211 {
2212         struct libusb_transfer *transfer =
2213                 USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
2214         struct linux_transfer_priv *tpriv = usbi_get_transfer_priv(itransfer);
2215
2216         switch (transfer->type) {
2217         case LIBUSB_TRANSFER_TYPE_CONTROL:
2218         case LIBUSB_TRANSFER_TYPE_BULK:
2219         case LIBUSB_TRANSFER_TYPE_BULK_STREAM:
2220         case LIBUSB_TRANSFER_TYPE_INTERRUPT:
2221                 if (tpriv->urbs) {
2222                         free(tpriv->urbs);
2223                         tpriv->urbs = NULL;
2224                 }
2225                 break;
2226         case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
2227                 if (tpriv->iso_urbs) {
2228                         free_iso_urbs(tpriv);
2229                         tpriv->iso_urbs = NULL;
2230                 }
2231                 break;
2232         default:
2233                 usbi_err(TRANSFER_CTX(transfer), "unknown transfer type %u", transfer->type);
2234         }
2235 }
2236
2237 static int handle_bulk_completion(struct usbi_transfer *itransfer,
2238         struct usbfs_urb *urb)
2239 {
2240         struct linux_transfer_priv *tpriv = usbi_get_transfer_priv(itransfer);
2241         struct libusb_transfer *transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
2242         int urb_idx = urb - tpriv->urbs;
2243
2244         usbi_mutex_lock(&itransfer->lock);
2245         usbi_dbg("handling completion status %d of bulk urb %d/%d", urb->status,
2246                  urb_idx + 1, tpriv->num_urbs);
2247
2248         tpriv->num_retired++;
2249
2250         if (tpriv->reap_action != NORMAL) {
2251                 /* cancelled, submit_fail, or completed early */
2252                 usbi_dbg("abnormal reap: urb status %d", urb->status);
2253
2254                 /* even though we're in the process of cancelling, it's possible that
2255                  * we may receive some data in these URBs that we don't want to lose.
2256                  * examples:
2257                  * 1. while the kernel is cancelling all the packets that make up an
2258                  *    URB, a few of them might complete. so we get back a successful
2259                  *    cancellation *and* some data.
2260                  * 2. we receive a short URB which marks the early completion condition,
2261                  *    so we start cancelling the remaining URBs. however, we're too
2262                  *    slow and another URB completes (or at least completes partially).
2263                  *    (this can't happen since we always use BULK_CONTINUATION.)
2264                  *
2265                  * When this happens, our objectives are not to lose any "surplus" data,
2266                  * and also to stick it at the end of the previously-received data
2267                  * (closing any holes), so that libusb reports the total amount of
2268                  * transferred data and presents it in a contiguous chunk.
2269                  */
2270                 if (urb->actual_length > 0) {
2271                         unsigned char *target = transfer->buffer + itransfer->transferred;
2272
2273                         usbi_dbg("received %d bytes of surplus data", urb->actual_length);
2274                         if (urb->buffer != target) {
2275                                 usbi_dbg("moving surplus data from offset %zu to offset %zu",
2276                                          (unsigned char *) urb->buffer - transfer->buffer,
2277                                          target - transfer->buffer);
2278                                 memmove(target, urb->buffer, urb->actual_length);
2279                         }
2280                         itransfer->transferred += urb->actual_length;
2281                 }
2282
2283                 if (tpriv->num_retired == tpriv->num_urbs) {
2284                         usbi_dbg("abnormal reap: last URB handled, reporting");
2285                         if (tpriv->reap_action != COMPLETED_EARLY &&
2286                             tpriv->reap_status == LIBUSB_TRANSFER_COMPLETED)
2287                                 tpriv->reap_status = LIBUSB_TRANSFER_ERROR;
2288                         goto completed;
2289                 }
2290                 goto out_unlock;
2291         }
2292
2293         itransfer->transferred += urb->actual_length;
2294
2295         /* Many of these errors can occur on *any* urb of a multi-urb
2296          * transfer.  When they do, we tear down the rest of the transfer.
2297          */
2298         switch (urb->status) {
2299         case 0:
2300                 break;
2301         case -EREMOTEIO: /* short transfer */
2302                 break;
2303         case -ENOENT: /* cancelled */
2304         case -ECONNRESET:
2305                 break;
2306         case -ENODEV:
2307         case -ESHUTDOWN:
2308                 usbi_dbg("device removed");
2309                 tpriv->reap_status = LIBUSB_TRANSFER_NO_DEVICE;
2310                 goto cancel_remaining;
2311         case -EPIPE:
2312                 usbi_dbg("detected endpoint stall");
2313                 if (tpriv->reap_status == LIBUSB_TRANSFER_COMPLETED)
2314                         tpriv->reap_status = LIBUSB_TRANSFER_STALL;
2315                 goto cancel_remaining;
2316         case -EOVERFLOW:
2317                 /* overflow can only ever occur in the last urb */
2318                 usbi_dbg("overflow, actual_length=%d", urb->actual_length);
2319                 if (tpriv->reap_status == LIBUSB_TRANSFER_COMPLETED)
2320                         tpriv->reap_status = LIBUSB_TRANSFER_OVERFLOW;
2321                 goto completed;
2322         case -ETIME:
2323         case -EPROTO:
2324         case -EILSEQ:
2325         case -ECOMM:
2326         case -ENOSR:
2327                 usbi_dbg("low-level bus error %d", urb->status);
2328                 tpriv->reap_action = ERROR;
2329                 goto cancel_remaining;
2330         default:
2331                 usbi_warn(ITRANSFER_CTX(itransfer), "unrecognised urb status %d", urb->status);
2332                 tpriv->reap_action = ERROR;
2333                 goto cancel_remaining;
2334         }
2335
2336         /* if we've reaped all urbs or we got less data than requested then we're
2337          * done */
2338         if (tpriv->num_retired == tpriv->num_urbs) {
2339                 usbi_dbg("all URBs in transfer reaped --> complete!");
2340                 goto completed;
2341         } else if (urb->actual_length < urb->buffer_length) {
2342                 usbi_dbg("short transfer %d/%d --> complete!",
2343                          urb->actual_length, urb->buffer_length);
2344                 if (tpriv->reap_action == NORMAL)
2345                         tpriv->reap_action = COMPLETED_EARLY;
2346         } else {
2347                 goto out_unlock;
2348         }
2349
2350 cancel_remaining:
2351         if (tpriv->reap_action == ERROR && tpriv->reap_status == LIBUSB_TRANSFER_COMPLETED)
2352                 tpriv->reap_status = LIBUSB_TRANSFER_ERROR;
2353
2354         if (tpriv->num_retired == tpriv->num_urbs) /* nothing to cancel */
2355                 goto completed;
2356
2357         /* cancel remaining urbs and wait for their completion before
2358          * reporting results */
2359         discard_urbs(itransfer, urb_idx + 1, tpriv->num_urbs);
2360
2361 out_unlock:
2362         usbi_mutex_unlock(&itransfer->lock);
2363         return 0;
2364
2365 completed:
2366         free(tpriv->urbs);
2367         tpriv->urbs = NULL;
2368         usbi_mutex_unlock(&itransfer->lock);
2369         return tpriv->reap_action == CANCELLED ?
2370                 usbi_handle_transfer_cancellation(itransfer) :
2371                 usbi_handle_transfer_completion(itransfer, tpriv->reap_status);
2372 }
2373
2374 static int handle_iso_completion(struct usbi_transfer *itransfer,
2375         struct usbfs_urb *urb)
2376 {
2377         struct libusb_transfer *transfer =
2378                 USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
2379         struct linux_transfer_priv *tpriv = usbi_get_transfer_priv(itransfer);
2380         int num_urbs = tpriv->num_urbs;
2381         int urb_idx = 0;
2382         int i;
2383         enum libusb_transfer_status status = LIBUSB_TRANSFER_COMPLETED;
2384
2385         usbi_mutex_lock(&itransfer->lock);
2386         for (i = 0; i < num_urbs; i++) {
2387                 if (urb == tpriv->iso_urbs[i]) {
2388                         urb_idx = i + 1;
2389                         break;
2390                 }
2391         }
2392         if (urb_idx == 0) {
2393                 usbi_err(TRANSFER_CTX(transfer), "could not locate urb!");
2394                 usbi_mutex_unlock(&itransfer->lock);
2395                 return LIBUSB_ERROR_NOT_FOUND;
2396         }
2397
2398         usbi_dbg("handling completion status %d of iso urb %d/%d", urb->status,
2399                  urb_idx, num_urbs);
2400
2401         /* copy isochronous results back in */
2402
2403         for (i = 0; i < urb->number_of_packets; i++) {
2404                 struct usbfs_iso_packet_desc *urb_desc = &urb->iso_frame_desc[i];
2405                 struct libusb_iso_packet_descriptor *lib_desc =
2406                         &transfer->iso_packet_desc[tpriv->iso_packet_offset++];
2407
2408                 lib_desc->status = LIBUSB_TRANSFER_COMPLETED;
2409                 switch (urb_desc->status) {
2410                 case 0:
2411                         break;
2412                 case -ENOENT: /* cancelled */
2413                 case -ECONNRESET:
2414                         break;
2415                 case -ENODEV:
2416                 case -ESHUTDOWN:
2417                         usbi_dbg("packet %d - device removed", i);
2418                         lib_desc->status = LIBUSB_TRANSFER_NO_DEVICE;
2419                         break;
2420                 case -EPIPE:
2421                         usbi_dbg("packet %d - detected endpoint stall", i);
2422                         lib_desc->status = LIBUSB_TRANSFER_STALL;
2423                         break;
2424                 case -EOVERFLOW:
2425                         usbi_dbg("packet %d - overflow error", i);
2426                         lib_desc->status = LIBUSB_TRANSFER_OVERFLOW;
2427                         break;
2428                 case -ETIME:
2429                 case -EPROTO:
2430                 case -EILSEQ:
2431                 case -ECOMM:
2432                 case -ENOSR:
2433                 case -EXDEV:
2434                         usbi_dbg("packet %d - low-level USB error %d", i, urb_desc->status);
2435                         lib_desc->status = LIBUSB_TRANSFER_ERROR;
2436                         break;
2437                 default:
2438                         usbi_warn(TRANSFER_CTX(transfer), "packet %d - unrecognised urb status %d",
2439                                   i, urb_desc->status);
2440                         lib_desc->status = LIBUSB_TRANSFER_ERROR;
2441                         break;
2442                 }
2443                 lib_desc->actual_length = urb_desc->actual_length;
2444         }
2445
2446         tpriv->num_retired++;
2447
2448         if (tpriv->reap_action != NORMAL) { /* cancelled or submit_fail */
2449                 usbi_dbg("CANCEL: urb status %d", urb->status);
2450
2451                 if (tpriv->num_retired == num_urbs) {
2452                         usbi_dbg("CANCEL: last URB handled, reporting");
2453                         free_iso_urbs(tpriv);
2454                         if (tpriv->reap_action == CANCELLED) {
2455                                 usbi_mutex_unlock(&itransfer->lock);
2456                                 return usbi_handle_transfer_cancellation(itransfer);
2457                         } else {
2458                                 usbi_mutex_unlock(&itransfer->lock);
2459                                 return usbi_handle_transfer_completion(itransfer, LIBUSB_TRANSFER_ERROR);
2460                         }
2461                 }
2462                 goto out;
2463         }
2464
2465         switch (urb->status) {
2466         case 0:
2467                 break;
2468         case -ENOENT: /* cancelled */
2469         case -ECONNRESET:
2470                 break;
2471         case -ESHUTDOWN:
2472                 usbi_dbg("device removed");
2473                 status = LIBUSB_TRANSFER_NO_DEVICE;
2474                 break;
2475         default:
2476                 usbi_warn(TRANSFER_CTX(transfer), "unrecognised urb status %d", urb->status);
2477                 status = LIBUSB_TRANSFER_ERROR;
2478                 break;
2479         }
2480
2481         /* if we've reaped all urbs then we're done */
2482         if (tpriv->num_retired == num_urbs) {
2483                 usbi_dbg("all URBs in transfer reaped --> complete!");
2484                 free_iso_urbs(tpriv);
2485                 usbi_mutex_unlock(&itransfer->lock);
2486                 return usbi_handle_transfer_completion(itransfer, status);
2487         }
2488
2489 out:
2490         usbi_mutex_unlock(&itransfer->lock);
2491         return 0;
2492 }
2493
2494 static int handle_control_completion(struct usbi_transfer *itransfer,
2495         struct usbfs_urb *urb)
2496 {
2497         struct linux_transfer_priv *tpriv = usbi_get_transfer_priv(itransfer);
2498         int status;
2499
2500         usbi_mutex_lock(&itransfer->lock);
2501         usbi_dbg("handling completion status %d", urb->status);
2502
2503         itransfer->transferred += urb->actual_length;
2504
2505         if (tpriv->reap_action == CANCELLED) {
2506                 if (urb->status && urb->status != -ENOENT)
2507                         usbi_warn(ITRANSFER_CTX(itransfer), "cancel: unrecognised urb status %d",
2508                                   urb->status);
2509                 free(tpriv->urbs);
2510                 tpriv->urbs = NULL;
2511                 usbi_mutex_unlock(&itransfer->lock);
2512                 return usbi_handle_transfer_cancellation(itransfer);
2513         }
2514
2515         switch (urb->status) {
2516         case 0:
2517                 status = LIBUSB_TRANSFER_COMPLETED;
2518                 break;
2519         case -ENOENT: /* cancelled */
2520                 status = LIBUSB_TRANSFER_CANCELLED;
2521                 break;
2522         case -ENODEV:
2523         case -ESHUTDOWN:
2524                 usbi_dbg("device removed");
2525                 status = LIBUSB_TRANSFER_NO_DEVICE;
2526                 break;
2527         case -EPIPE:
2528                 usbi_dbg("unsupported control request");
2529                 status = LIBUSB_TRANSFER_STALL;
2530                 break;
2531         case -EOVERFLOW:
2532                 usbi_dbg("overflow, actual_length=%d", urb->actual_length);
2533                 status = LIBUSB_TRANSFER_OVERFLOW;
2534                 break;
2535         case -ETIME:
2536         case -EPROTO:
2537         case -EILSEQ:
2538         case -ECOMM:
2539         case -ENOSR:
2540                 usbi_dbg("low-level bus error %d", urb->status);
2541                 status = LIBUSB_TRANSFER_ERROR;
2542                 break;
2543         default:
2544                 usbi_warn(ITRANSFER_CTX(itransfer), "unrecognised urb status %d", urb->status);
2545                 status = LIBUSB_TRANSFER_ERROR;
2546                 break;
2547         }
2548
2549         free(tpriv->urbs);
2550         tpriv->urbs = NULL;
2551         usbi_mutex_unlock(&itransfer->lock);
2552         return usbi_handle_transfer_completion(itransfer, status);
2553 }
2554
2555 static int reap_for_handle(struct libusb_device_handle *handle)
2556 {
2557         struct linux_device_handle_priv *hpriv = usbi_get_device_handle_priv(handle);
2558         int r;
2559         struct usbfs_urb *urb = NULL;
2560         struct usbi_transfer *itransfer;
2561         struct libusb_transfer *transfer;
2562
2563         r = ioctl(hpriv->fd, IOCTL_USBFS_REAPURBNDELAY, &urb);
2564         if (r < 0) {
2565                 if (errno == EAGAIN)
2566                         return 1;
2567                 if (errno == ENODEV)
2568                         return LIBUSB_ERROR_NO_DEVICE;
2569
2570                 usbi_err(HANDLE_CTX(handle), "reap failed, errno=%d", errno);
2571                 return LIBUSB_ERROR_IO;
2572         }
2573
2574         itransfer = urb->usercontext;
2575         transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
2576
2577         usbi_dbg("urb type=%u status=%d transferred=%d", urb->type, urb->status, urb->actual_length);
2578
2579         switch (transfer->type) {
2580         case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
2581                 return handle_iso_completion(itransfer, urb);
2582         case LIBUSB_TRANSFER_TYPE_BULK:
2583         case LIBUSB_TRANSFER_TYPE_BULK_STREAM:
2584         case LIBUSB_TRANSFER_TYPE_INTERRUPT:
2585                 return handle_bulk_completion(itransfer, urb);
2586         case LIBUSB_TRANSFER_TYPE_CONTROL:
2587                 return handle_control_completion(itransfer, urb);
2588         default:
2589                 usbi_err(HANDLE_CTX(handle), "unrecognised transfer type %u", transfer->type);
2590                 return LIBUSB_ERROR_OTHER;
2591         }
2592 }
2593
2594 static int op_handle_events(struct libusb_context *ctx,
2595         struct pollfd *fds, usbi_nfds_t nfds, int num_ready)
2596 {
2597         usbi_nfds_t n;
2598         int r;
2599
2600         usbi_mutex_lock(&ctx->open_devs_lock);
2601         for (n = 0; n < nfds && num_ready > 0; n++) {
2602                 struct pollfd *pollfd = &fds[n];
2603                 struct libusb_device_handle *handle;
2604                 struct linux_device_handle_priv *hpriv = NULL;
2605
2606                 if (!pollfd->revents)
2607                         continue;
2608
2609                 num_ready--;
2610                 list_for_each_entry(handle, &ctx->open_devs, list, struct libusb_device_handle) {
2611                         hpriv = usbi_get_device_handle_priv(handle);
2612                         if (hpriv->fd == pollfd->fd)
2613                                 break;
2614                 }
2615
2616                 if (!hpriv || hpriv->fd != pollfd->fd) {
2617                         usbi_err(ctx, "cannot find handle for fd %d",
2618                                  pollfd->fd);
2619                         continue;
2620                 }
2621
2622                 if (pollfd->revents & POLLERR) {
2623                         /* remove the fd from the pollfd set so that it doesn't continuously
2624                          * trigger an event, and flag that it has been removed so op_close()
2625                          * doesn't try to remove it a second time */
2626                         usbi_remove_pollfd(HANDLE_CTX(handle), hpriv->fd);
2627                         hpriv->fd_removed = 1;
2628
2629                         /* device will still be marked as attached if hotplug monitor thread
2630                          * hasn't processed remove event yet */
2631                         usbi_mutex_static_lock(&linux_hotplug_lock);
2632                         if (handle->dev->attached)
2633                                 linux_device_disconnected(handle->dev->bus_number,
2634                                                           handle->dev->device_address);
2635                         usbi_mutex_static_unlock(&linux_hotplug_lock);
2636
2637                         if (hpriv->caps & USBFS_CAP_REAP_AFTER_DISCONNECT) {
2638                                 do {
2639                                         r = reap_for_handle(handle);
2640                                 } while (r == 0);
2641                         }
2642
2643                         usbi_handle_disconnect(handle);
2644                         continue;
2645                 }
2646
2647                 do {
2648                         r = reap_for_handle(handle);
2649                 } while (r == 0);
2650                 if (r == 1 || r == LIBUSB_ERROR_NO_DEVICE)
2651                         continue;
2652                 else if (r < 0)
2653                         goto out;
2654         }
2655
2656         r = 0;
2657 out:
2658         usbi_mutex_unlock(&ctx->open_devs_lock);
2659         return r;
2660 }
2661
2662 const struct usbi_os_backend usbi_backend = {
2663         .name = "Linux usbfs",
2664         .caps = USBI_CAP_HAS_HID_ACCESS|USBI_CAP_SUPPORTS_DETACH_KERNEL_DRIVER,
2665         .init = op_init,
2666         .exit = op_exit,
2667         .hotplug_poll = op_hotplug_poll,
2668         .get_device_descriptor = op_get_device_descriptor,
2669         .get_active_config_descriptor = op_get_active_config_descriptor,
2670         .get_config_descriptor = op_get_config_descriptor,
2671         .get_config_descriptor_by_value = op_get_config_descriptor_by_value,
2672
2673         .wrap_sys_device = op_wrap_sys_device,
2674         .open = op_open,
2675         .close = op_close,
2676         .get_configuration = op_get_configuration,
2677         .set_configuration = op_set_configuration,
2678         .claim_interface = op_claim_interface,
2679         .release_interface = op_release_interface,
2680
2681         .set_interface_altsetting = op_set_interface,
2682         .clear_halt = op_clear_halt,
2683         .reset_device = op_reset_device,
2684
2685         .alloc_streams = op_alloc_streams,
2686         .free_streams = op_free_streams,
2687
2688         .dev_mem_alloc = op_dev_mem_alloc,
2689         .dev_mem_free = op_dev_mem_free,
2690
2691         .kernel_driver_active = op_kernel_driver_active,
2692         .detach_kernel_driver = op_detach_kernel_driver,
2693         .attach_kernel_driver = op_attach_kernel_driver,
2694
2695         .destroy_device = op_destroy_device,
2696
2697         .submit_transfer = op_submit_transfer,
2698         .cancel_transfer = op_cancel_transfer,
2699         .clear_transfer_priv = op_clear_transfer_priv,
2700
2701         .handle_events = op_handle_events,
2702
2703         .device_priv_size = sizeof(struct linux_device_priv),
2704         .device_handle_priv_size = sizeof(struct linux_device_handle_priv),
2705         .transfer_priv_size = sizeof(struct linux_transfer_priv),
2706 };