1/*
2 * \file libusb-glue.c
3 * Low-level USB interface glue towards libusb.
4 *
5 * Copyright (C) 2005-2007 Richard A. Low <richard@wentnet.com>
6 * Copyright (C) 2005-2008 Linus Walleij <triad@df.lth.se>
7 * Copyright (C) 2006-2007 Marcus Meissner
8 * Copyright (C) 2007 Ted Bullock
9 * Copyright (C) 2008 Chris Bagwell <chris@cnpbagwell.com>
10 *
11 * This library is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Lesser General Public
13 * License as published by the Free Software Foundation; either
14 * version 2 of the License, or (at your option) any later version.
15 *
16 * This library is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19 * Lesser General Public License for more details.
20 *
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with this library; if not, write to the
23 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
24 * Boston, MA 02111-1307, USA.
25 *
26 * Created by Richard Low on 24/12/2005. (as mtp-utils.c)
27 * Modified by Linus Walleij 2006-03-06
28 *  (Notice that Anglo-Saxons use little-endian dates and Swedes
29 *   use big-endian dates.)
30 *
31 */
32#include "config.h"
33#include "libmtp.h"
34#include "libusb-glue.h"
35#include "device-flags.h"
36#include "util.h"
37#include "ptp.h"
38
39#include <errno.h>
40#include <stdio.h>
41#include <stdlib.h>
42#include <string.h>
43#include <usb.h>
44
45#include "ptp-pack.c"
46
47/* Aha, older libusb does not have USB_CLASS_PTP */
48#ifndef USB_CLASS_PTP
49#define USB_CLASS_PTP 6
50#endif
51
52/* libusb dosn't have misc class defined */
53#ifndef USB_CLASS_MISC
54#define USB_CLASS_MISC 0xEF
55#endif
56
57#define APPLE_VID 0x05ac
58
59/* To enable debug prints for USB stuff, switch on this */
60//#define ENABLE_USB_BULK_DEBUG
61
62/* Default USB timeout length.  This can be overridden as needed
63 * but should start with a reasonable value so most common
64 * requests can be completed.  The original value of 4000 was
65 * not long enough for large file transfer.  Also, players can
66 * spend a bit of time collecting data.  Higher values also
67 * make connecting/disconnecting more reliable.
68 */
69#define USB_TIMEOUT_DEFAULT     10000
70
71/* USB control message data phase direction */
72#ifndef USB_DP_HTD
73#define USB_DP_HTD		(0x00 << 7)	/* host to device */
74#endif
75#ifndef USB_DP_DTH
76#define USB_DP_DTH		(0x01 << 7)	/* device to host */
77#endif
78
79/* USB Feature selector HALT */
80#ifndef USB_FEATURE_HALT
81#define USB_FEATURE_HALT	0x00
82#endif
83
84/* Internal data types */
85struct mtpdevice_list_struct {
86  struct usb_device *libusb_device;
87  PTPParams *params;
88  PTP_USB *ptp_usb;
89  uint32_t bus_location;
90  struct mtpdevice_list_struct *next;
91};
92typedef struct mtpdevice_list_struct mtpdevice_list_t;
93
94static const LIBMTP_device_entry_t mtp_device_table[] = {
95/* We include an .h file which is shared between us and libgphoto2 */
96#include "music-players.h"
97};
98static const int mtp_device_table_size = sizeof(mtp_device_table) / sizeof(LIBMTP_device_entry_t);
99
100// Local functions
101static struct usb_bus* init_usb();
102static void close_usb(PTP_USB* ptp_usb);
103static void find_interface_and_endpoints(struct usb_device *dev,
104					 uint8_t *interface,
105					 int* inep,
106					 int* inep_maxpacket,
107					 int* outep,
108					 int* outep_maxpacket,
109					 int* intep);
110static void clear_stall(PTP_USB* ptp_usb);
111static int init_ptp_usb (PTPParams* params, PTP_USB* ptp_usb, struct usb_device* dev);
112static short ptp_write_func (unsigned long,PTPDataHandler*,void *data,unsigned long*);
113static short ptp_read_func (unsigned long,PTPDataHandler*,void *data,unsigned long*,int);
114static int usb_clear_stall_feature(PTP_USB* ptp_usb, int ep);
115static int usb_get_endpoint_status(PTP_USB* ptp_usb, int ep, uint16_t* status);
116
117/**
118 * Get a list of the supported USB devices.
119 *
120 * The developers depend on users of this library to constantly
121 * add in to the list of supported devices. What we need is the
122 * device name, USB Vendor ID (VID) and USB Product ID (PID).
123 * put this into a bug ticket at the project homepage, please.
124 * The VID/PID is used to let e.g. udev lift the device to
125 * console userspace access when it's plugged in.
126 *
127 * @param devices a pointer to a pointer that will hold a device
128 *        list after the call to this function, if it was
129 *        successful.
130 * @param numdevs a pointer to an integer that will hold the number
131 *        of devices in the device list if the call was successful.
132 * @return 0 if the list was successfull retrieved, any other
133 *        value means failure.
134 */
135int LIBMTP_Get_Supported_Devices_List(LIBMTP_device_entry_t ** const devices, int * const numdevs)
136{
137  *devices = (LIBMTP_device_entry_t *) &mtp_device_table;
138  *numdevs = mtp_device_table_size;
139  return 0;
140}
141
142
143static struct usb_bus* init_usb()
144{
145  usb_init();
146  usb_find_busses();
147  usb_find_devices();
148  return (usb_get_busses());
149}
150
151/**
152 * Small recursive function to append a new usb_device to the linked list of
153 * USB MTP devices
154 * @param devlist dynamic linked list of pointers to usb devices with MTP
155 *        properties, to be extended with new device.
156 * @param newdevice the new device to add.
157 * @param bus_location bus for this device.
158 * @return an extended array or NULL on failure.
159 */
160static mtpdevice_list_t *append_to_mtpdevice_list(mtpdevice_list_t *devlist,
161						  struct usb_device *newdevice,
162						  uint32_t bus_location)
163{
164  mtpdevice_list_t *new_list_entry;
165
166  new_list_entry = (mtpdevice_list_t *) malloc(sizeof(mtpdevice_list_t));
167  if (new_list_entry == NULL) {
168    return NULL;
169  }
170  // Fill in USB device, if we *HAVE* to make a copy of the device do it here.
171  new_list_entry->libusb_device = newdevice;
172  new_list_entry->bus_location = bus_location;
173  new_list_entry->next = NULL;
174
175  if (devlist == NULL) {
176    return new_list_entry;
177  } else {
178    mtpdevice_list_t *tmp = devlist;
179    while (tmp->next != NULL) {
180      tmp = tmp->next;
181    }
182    tmp->next = new_list_entry;
183  }
184  return devlist;
185}
186
187/**
188 * Small recursive function to free dynamic memory allocated to the linked list
189 * of USB MTP devices
190 * @param devlist dynamic linked list of pointers to usb devices with MTP
191 * properties.
192 * @return nothing
193 */
194static void free_mtpdevice_list(mtpdevice_list_t *devlist)
195{
196  mtpdevice_list_t *tmplist = devlist;
197
198  if (devlist == NULL)
199    return;
200  while (tmplist != NULL) {
201    mtpdevice_list_t *tmp = tmplist;
202    tmplist = tmplist->next;
203    // Do not free() the fields (ptp_usb, params)! These are used elsewhere.
204    free(tmp);
205  }
206  return;
207}
208
209/* Comment out this define to enable the original, more aggressive probing. */
210#define MILD_MTP_PROBING
211
212#ifdef MILD_MTP_PROBING
213/**
214 * This checks if a device has an interface with MTP description.
215 *
216 * @param dev a device struct from libusb.
217 * @param dumpfile set to non-NULL to make the descriptors dump out
218 *        to this file in human-readable hex so we can scruitinze them.
219 * @return 1 if the device is MTP compliant, 0 if not.
220 */
221static int probe_device_descriptor(struct usb_device *dev, FILE *dumpfile)
222{
223  usb_dev_handle *devh;
224  unsigned char buf[1024];
225  int i;
226  int ret;
227
228  /*
229   * Don't examine devices that are not likely to
230   * contain any MTP interface, update this the day
231   * you find some weird combination...
232   */
233  if (!(dev->descriptor.bDeviceClass == USB_CLASS_PER_INTERFACE ||
234	    dev->descriptor.bDeviceClass == USB_CLASS_PTP ||
235	    dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC) ||
236      /* Apple devices sometimes freeze when probed by libusb */
237      dev->descriptor.idVendor == APPLE_VID) {
238    return 0;
239  }
240
241  /* Attempt to open Device on this port */
242  devh = usb_open(dev);
243  if (devh == NULL) {
244    /* Could not open this device */
245    return 0;
246  }
247
248  /*
249   * This sometimes crashes on the j for loop below
250   * I think it is because config is NULL yet
251   * dev->descriptor.bNumConfigurations > 0
252   * this check should stop this
253   */
254  if (dev->config) {
255    /*
256     * Loop over the interfaces, and check for string "MTP"
257     * in the descriptions.
258     */
259
260    for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
261      uint8_t j;
262
263      for (j = 0; j < dev->config[i].bNumInterfaces; j++) {
264        int k;
265        for (k = 0; k < dev->config[i].interface[j].num_altsetting; k++) {
266	  /* Current interface descriptor */
267	  struct usb_interface_descriptor *intf =
268	    &dev->config[i].interface[j].altsetting[k];
269
270          buf[0] = '\0';
271          ret = usb_get_string_simple(devh,
272				      dev->config[i].interface[j].altsetting[k].iInterface,
273				      (char *) buf,
274				      1024);
275
276	  if (ret < 3)
277	    continue;
278          if (strcmp((char *) buf, "MTP") == 0) {
279	    if (dumpfile != NULL) {
280              fprintf(dumpfile, "Configuration %d, interface %d, altsetting %d:\n", i, j, k);
281	      fprintf(dumpfile, "   Interface description contains the string \"MTP\"\n");
282	      fprintf(dumpfile, "   Device recognized as MTP, no further probing.\n");
283	    }
284            usb_close(devh);
285            return 1;
286          }
287       }
288      }
289    }
290  }
291
292  usb_close(devh);
293  return 0;
294}
295
296#else /* MILD_MTP_PROBING */
297/**
298 * This checks if a device has an MTP descriptor. The descriptor was
299 * elaborated about in gPhoto bug 1482084, and some official documentation
300 * with no strings attached was published by Microsoft at
301 * http://www.microsoft.com/whdc/system/bus/USB/USBFAQ_intermed.mspx#E3HAC
302 *
303 * @param dev a device struct from libusb.
304 * @param dumpfile set to non-NULL to make the descriptors dump out
305 *        to this file in human-readable hex so we can scruitinze them.
306 * @return 1 if the device is MTP compliant, 0 if not.
307 */
308static int probe_device_descriptor(struct usb_device *dev, FILE *dumpfile)
309{
310  usb_dev_handle *devh;
311  unsigned char buf[1024], cmd;
312  int i;
313  int ret;
314
315  /* Don't examine hubs (no point in that) */
316  if (dev->descriptor.bDeviceClass == USB_CLASS_HUB) {
317    return 0;
318  }
319
320  /* Attempt to open Device on this port */
321  devh = usb_open(dev);
322  if (devh == NULL) {
323    /* Could not open this device */
324    return 0;
325  }
326
327  /*
328   * This sometimes crashes on the j for loop below
329   * I think it is because config is NULL yet
330   * dev->descriptor.bNumConfigurations > 0
331   * this check should stop this
332   */
333  if (dev->config) {
334    /*
335     * Loop over the device configurations and interfaces. Nokia MTP-capable
336     * handsets (possibly others) typically have the string "MTP" in their
337     * MTP interface descriptions, that's how they can be detected, before
338     * we try the more esoteric "OS descriptors" (below).
339     */
340    for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
341      uint8_t j;
342
343      for (j = 0; j < dev->config[i].bNumInterfaces; j++) {
344        int k;
345        for (k = 0; k < dev->config[i].interface[j].num_altsetting; k++) {
346	  /* Current interface descriptor */
347	  struct usb_interface_descriptor *intf =
348	    &dev->config[i].interface[j].altsetting[k];
349
350
351          buf[0] = '\0';
352          ret = usb_get_string_simple(devh,
353				      dev->config[i].interface[j].altsetting[k].iInterface,
354				      (char *) buf,
355				      1024);
356	  if (ret < 3)
357	    continue;
358          if (strcmp((char *) buf, "MTP") == 0) {
359	    if (dumpfile != NULL) {
360              fprintf(dumpfile, "Configuration %d, interface %d, altsetting %d:\n", i, j, k);
361	      fprintf(dumpfile, "   Interface description contains the string \"MTP\"\n");
362	      fprintf(dumpfile, "   Device recognized as MTP, no further probing.\n");
363	    }
364            usb_close(devh);
365            return 1;
366          }
367  #ifdef LIBUSB_HAS_GET_DRIVER_NP
368	  {
369	    /*
370	     * Specifically avoid probing anything else than USB mass storage devices
371	     * and non-associated drivers in Linux.
372	     */
373	    char devname[0x10];
374
375	    devname[0] = '\0';
376	    ret = usb_get_driver_np(devh,
377				    dev->config[i].interface[j].altsetting[k].iInterface,
378				    devname,
379				    sizeof(devname));
380	    if (devname[0] != '\0' && strcmp(devname, "usb-storage")) {
381	      printf("avoid probing device using kernel interface \"%s\"\n", devname);
382	      return 0;
383	    }
384	  }
385  #endif
386        }
387      }
388    }
389  } else {
390    if (dev->descriptor.bNumConfigurations)
391      printf("dev->config is NULL in probe_device_descriptor yet dev->descriptor.bNumConfigurations > 0\n");
392  }
393
394  /* Read the special descriptor */
395  ret = usb_get_descriptor(devh, 0x03, 0xee, buf, sizeof(buf));
396
397  // Dump it, if requested
398  if (dumpfile != NULL && ret > 0) {
399    fprintf(dumpfile, "Microsoft device descriptor 0xee:\n");
400    data_dump_ascii(dumpfile, buf, ret, 16);
401  }
402
403  /* Check if descriptor length is at least 10 bytes */
404  if (ret < 10) {
405    usb_close(devh);
406    return 0;
407  }
408
409  /* Check if this device has a Microsoft Descriptor */
410  if (!((buf[2] == 'M') && (buf[4] == 'S') &&
411	(buf[6] == 'F') && (buf[8] == 'T'))) {
412    usb_close(devh);
413    return 0;
414  }
415
416  /* Check if device responds to control message 1 or if there is an error */
417  cmd = buf[16];
418  ret = usb_control_msg (devh,
419			 USB_ENDPOINT_IN|USB_RECIP_DEVICE|USB_TYPE_VENDOR,
420			 cmd,
421			 0,
422			 4,
423			 (char *) buf,
424			 sizeof(buf),
425                         USB_TIMEOUT_DEFAULT);
426
427  // Dump it, if requested
428  if (dumpfile != NULL && ret > 0) {
429    fprintf(dumpfile, "Microsoft device response to control message 1, CMD 0x%02x:\n", cmd);
430    data_dump_ascii(dumpfile, buf, ret, 16);
431  }
432
433  /* If this is true, the device either isn't MTP or there was an error */
434  if (ret <= 0x15) {
435    /* TODO: If there was an error, flag it and let the user know somehow */
436    /* if(ret == -1) {} */
437    usb_close(devh);
438    return 0;
439  }
440
441  /* Check if device is MTP or if it is something like a USB Mass Storage
442     device with Janus DRM support */
443  if ((buf[0x12] != 'M') || (buf[0x13] != 'T') || (buf[0x14] != 'P')) {
444    usb_close(devh);
445    return 0;
446  }
447
448  /* After this point we are probably dealing with an MTP device */
449
450  /* Check if device responds to control message 2 or if there is an error*/
451  ret = usb_control_msg (devh,
452			 USB_ENDPOINT_IN|USB_RECIP_DEVICE|USB_TYPE_VENDOR,
453			 cmd,
454			 0,
455			 5,
456			 (char *) buf,
457			 sizeof(buf),
458                         USB_TIMEOUT_DEFAULT);
459
460  // Dump it, if requested
461  if (dumpfile != NULL && ret > 0) {
462    fprintf(dumpfile, "Microsoft device response to control message 2, CMD 0x%02x:\n", cmd);
463    data_dump_ascii(dumpfile, buf, ret, 16);
464  }
465
466  /* If this is true, the device errored against control message 2 */
467  if (ret == -1) {
468    /* TODO: Implement callback function to let managing program know there
469       was a problem, along with description of the problem */
470    fprintf(stderr, "Potential MTP Device with VendorID:%04x and "
471	    "ProductID:%04x encountered an error responding to "
472	    "control message 2.\n"
473	    "Problems may arrise but continuing\n",
474	    dev->descriptor.idVendor, dev->descriptor.idProduct);
475  } else if (ret <= 0x15) {
476    /* TODO: Implement callback function to let managing program know there
477       was a problem, along with description of the problem */
478    fprintf(stderr, "Potential MTP Device with VendorID:%04x and "
479	    "ProductID:%04x responded to control message 2 with a "
480	    "response that was too short. Problems may arrise but "
481	    "continuing\n",
482	    dev->descriptor.idVendor, dev->descriptor.idProduct);
483  } else if ((buf[0x12] != 'M') || (buf[0x13] != 'T') || (buf[0x14] != 'P')) {
484    /* TODO: Implement callback function to let managing program know there
485       was a problem, along with description of the problem */
486    fprintf(stderr, "Potential MTP Device with VendorID:%04x and "
487	    "ProductID:%04x encountered an error responding to "
488	    "control message 2\n"
489	    "Problems may arrise but continuing\n",
490	    dev->descriptor.idVendor, dev->descriptor.idProduct);
491  }
492
493  /* Close the USB device handle */
494  usb_close(devh);
495  return 1;
496}
497#endif /* MILD_MTP_PROBING */
498
499/**
500 * This function scans through the connected usb devices on a machine and
501 * if they match known Vendor and Product identifiers appends them to the
502 * dynamic array mtp_device_list. Be sure to call
503 * <code>free_mtpdevice_list(mtp_device_list)</code> when you are done
504 * with it, assuming it is not NULL.
505 * @param mtp_device_list dynamic array of pointers to usb devices with MTP
506 *        properties (if this list is not empty, new entries will be appended
507 *        to the list).
508 * @return LIBMTP_ERROR_NONE implies that devices have been found, scan the list
509 *        appropriately. LIBMTP_ERROR_NO_DEVICE_ATTACHED implies that no
510 *        devices have been found.
511 */
512static LIBMTP_error_number_t get_mtp_usb_device_list(mtpdevice_list_t ** mtp_device_list)
513{
514  struct usb_bus *bus = init_usb();
515  for (; bus != NULL; bus = bus->next) {
516    struct usb_device *dev = bus->devices;
517    for (; dev != NULL; dev = dev->next) {
518      if (dev->descriptor.bDeviceClass != USB_CLASS_HUB) {
519	int i;
520        int found = 0;
521
522	// First check if we know about the device already.
523	// Devices well known to us will not have their descriptors
524	// probed, it caused problems with some devices.
525        for(i = 0; i < mtp_device_table_size; i++) {
526          if(dev->descriptor.idVendor == mtp_device_table[i].vendor_id &&
527            dev->descriptor.idProduct == mtp_device_table[i].product_id) {
528            /* Append this usb device to the MTP device list */
529            *mtp_device_list = append_to_mtpdevice_list(*mtp_device_list,
530							dev,
531							bus->location);
532            found = 1;
533            break;
534          }
535        }
536	// If we didn't know it, try probing the "OS Descriptor".
537        if (!found) {
538          if (probe_device_descriptor(dev, NULL)) {
539            /* Append this usb device to the MTP USB Device List */
540            *mtp_device_list = append_to_mtpdevice_list(*mtp_device_list,
541							dev,
542							bus->location);
543          }
544          /*
545	   * By thomas_-_s: Also append devices that are no MTP but PTP devices
546	   * if this is commented out.
547	   */
548	  /*
549	  else {
550	    // Check whether the device is no USB hub but a PTP.
551	    if ( dev->config != NULL &&dev->config->interface->altsetting->bInterfaceClass == USB_CLASS_PTP && dev->descriptor.bDeviceClass != USB_CLASS_HUB ) {
552	      *mtp_device_list = append_to_mtpdevice_list(*mtp_device_list, dev, bus->location);
553	    }
554          }
555	  */
556        }
557      }
558    }
559  }
560
561  /* If nothing was found we end up here. */
562  if(*mtp_device_list == NULL) {
563    return LIBMTP_ERROR_NO_DEVICE_ATTACHED;
564  }
565  return LIBMTP_ERROR_NONE;
566}
567
568/**
569 * Detect the raw MTP device descriptors and return a list of
570 * of the devices found.
571 *
572 * @param devices a pointer to a variable that will hold
573 *        the list of raw devices found. This may be NULL
574 *        on return if the number of detected devices is zero.
575 *        The user shall simply <code>free()</code> this
576 *        variable when finished with the raw devices,
577 *        in order to release memory.
578 * @param numdevs a pointer to an integer that will hold
579 *        the number of devices in the list. This may
580 *        be 0.
581 * @return 0 if successful, any other value means failure.
582 */
583LIBMTP_error_number_t LIBMTP_Detect_Raw_Devices(LIBMTP_raw_device_t ** devices,
584			      int * numdevs)
585{
586  mtpdevice_list_t *devlist = NULL;
587  mtpdevice_list_t *dev;
588  LIBMTP_error_number_t ret;
589  LIBMTP_raw_device_t *retdevs;
590  int devs = 0;
591  int i, j;
592
593  ret = get_mtp_usb_device_list(&devlist);
594  if (ret == LIBMTP_ERROR_NO_DEVICE_ATTACHED) {
595    *devices = NULL;
596    *numdevs = 0;
597    return ret;
598  } else if (ret != LIBMTP_ERROR_NONE) {
599    fprintf(stderr, "LIBMTP PANIC: get_mtp_usb_device_list() "
600	    "error code: %d on line %d\n", ret, __LINE__);
601    return ret;
602  }
603
604  // Get list size
605  dev = devlist;
606  while (dev != NULL) {
607    devs++;
608    dev = dev->next;
609  }
610  if (devs == 0) {
611    *devices = NULL;
612    *numdevs = 0;
613    return LIBMTP_ERROR_NONE;
614  }
615  // Conjure a device list
616  retdevs = (LIBMTP_raw_device_t *) malloc(sizeof(LIBMTP_raw_device_t) * devs);
617  if (retdevs == NULL) {
618    // Out of memory
619    *devices = NULL;
620    *numdevs = 0;
621    return LIBMTP_ERROR_MEMORY_ALLOCATION;
622  }
623  dev = devlist;
624  i = 0;
625  while (dev != NULL) {
626    int device_known = 0;
627
628    // Assign default device info
629    retdevs[i].device_entry.vendor = NULL;
630    retdevs[i].device_entry.vendor_id = dev->libusb_device->descriptor.idVendor;
631    retdevs[i].device_entry.product = NULL;
632    retdevs[i].device_entry.product_id = dev->libusb_device->descriptor.idProduct;
633    retdevs[i].device_entry.device_flags = 0x00000000U;
634    // See if we can locate some additional vendor info and device flags
635    for(j = 0; j < mtp_device_table_size; j++) {
636      if(dev->libusb_device->descriptor.idVendor == mtp_device_table[j].vendor_id &&
637	 dev->libusb_device->descriptor.idProduct == mtp_device_table[j].product_id) {
638	device_known = 1;
639	retdevs[i].device_entry.vendor = mtp_device_table[j].vendor;
640	retdevs[i].device_entry.product = mtp_device_table[j].product;
641	retdevs[i].device_entry.device_flags = mtp_device_table[j].device_flags;
642
643#ifdef _AFT_BUILD
644    // Disable the following features for all devices.
645	retdevs[i].device_entry.device_flags |= DEVICE_FLAG_BROKEN_MTPGETOBJPROPLIST|
646                                            DEVICE_FLAG_BROKEN_SET_OBJECT_PROPLIST|
647                                            DEVICE_FLAG_BROKEN_SEND_OBJECT_PROPLIST;
648#endif
649
650#ifdef ENABLE_USB_BULK_DEBUG
651	// This device is known to the developers
652	fprintf(stderr, "Device %d (VID=%04x and PID=%04x) is a %s %s.\n",
653		i,
654		dev->libusb_device->descriptor.idVendor,
655		dev->libusb_device->descriptor.idProduct,
656		mtp_device_table[j].vendor,
657		mtp_device_table[j].product);
658#endif
659	break;
660      }
661    }
662    if (!device_known) {
663      // This device is unknown to the developers
664      fprintf(stderr, "Device %d (VID=%04x and PID=%04x) is UNKNOWN.\n",
665	      i,
666	      dev->libusb_device->descriptor.idVendor,
667	      dev->libusb_device->descriptor.idProduct);
668      fprintf(stderr, "Please report this VID/PID and the device model to the "
669	      "libmtp development team\n");
670      /*
671       * Trying to get iManufacturer or iProduct from the device at this
672       * point would require opening a device handle, that we don't want
673       * to do right now. (Takes time for no good enough reason.)
674       */
675    }
676    // Save the location on the bus
677    retdevs[i].bus_location = dev->bus_location;
678    retdevs[i].devnum = dev->libusb_device->devnum;
679    i++;
680    dev = dev->next;
681  }
682  *devices = retdevs;
683  *numdevs = i;
684  free_mtpdevice_list(devlist);
685  return LIBMTP_ERROR_NONE;
686}
687
688/**
689 * This routine just dumps out low-level
690 * USB information about the current device.
691 * @param ptp_usb the USB device to get information from.
692 */
693void dump_usbinfo(PTP_USB *ptp_usb)
694{
695  struct usb_device *dev;
696
697#ifdef LIBUSB_HAS_GET_DRIVER_NP
698  char devname[0x10];
699  int res;
700
701  devname[0] = '\0';
702  res = usb_get_driver_np(ptp_usb->handle, (int) ptp_usb->interface, devname, sizeof(devname));
703  if (devname[0] != '\0') {
704    printf("   Using kernel interface \"%s\"\n", devname);
705  }
706#endif
707  dev = usb_device(ptp_usb->handle);
708  printf("   bcdUSB: %d\n", dev->descriptor.bcdUSB);
709  printf("   bDeviceClass: %d\n", dev->descriptor.bDeviceClass);
710  printf("   bDeviceSubClass: %d\n", dev->descriptor.bDeviceSubClass);
711  printf("   bDeviceProtocol: %d\n", dev->descriptor.bDeviceProtocol);
712  printf("   idVendor: %04x\n", dev->descriptor.idVendor);
713  printf("   idProduct: %04x\n", dev->descriptor.idProduct);
714  printf("   IN endpoint maxpacket: %d bytes\n", ptp_usb->inep_maxpacket);
715  printf("   OUT endpoint maxpacket: %d bytes\n", ptp_usb->outep_maxpacket);
716  printf("   Raw device info:\n");
717  printf("      Bus location: %d\n", ptp_usb->rawdevice.bus_location);
718  printf("      Device number: %d\n", ptp_usb->rawdevice.devnum);
719  printf("      Device entry info:\n");
720  printf("         Vendor: %s\n", ptp_usb->rawdevice.device_entry.vendor);
721  printf("         Vendor id: 0x%04x\n", ptp_usb->rawdevice.device_entry.vendor_id);
722  printf("         Product: %s\n", ptp_usb->rawdevice.device_entry.product);
723  printf("         Vendor id: 0x%04x\n", ptp_usb->rawdevice.device_entry.product_id);
724  printf("         Device flags: 0x%08x\n", ptp_usb->rawdevice.device_entry.device_flags);
725  (void) probe_device_descriptor(dev, stdout);
726}
727
728/**
729 * Retrieve the apropriate playlist extension for this
730 * device. Rather hacky at the moment. This is probably
731 * desired by the managing software, but when creating
732 * lists on the device itself you notice certain preferences.
733 * @param ptp_usb the USB device to get suggestion for.
734 * @return the suggested playlist extension.
735 */
736const char *get_playlist_extension(PTP_USB *ptp_usb)
737{
738  struct usb_device *dev;
739  static char creative_pl_extension[] = ".zpl";
740  static char default_pl_extension[] = ".pla";
741
742  dev = usb_device(ptp_usb->handle);
743  if (dev->descriptor.idVendor == 0x041e) {
744    return creative_pl_extension;
745  }
746  return default_pl_extension;
747}
748
749static void
750libusb_glue_debug (PTPParams *params, const char *format, ...)
751{
752        va_list args;
753
754        va_start (args, format);
755        if (params->debug_func!=NULL)
756                params->debug_func (params->data, format, args);
757        else
758	{
759                vfprintf (stderr, format, args);
760		fprintf (stderr,"\n");
761		fflush (stderr);
762	}
763        va_end (args);
764}
765
766static void
767libusb_glue_error (PTPParams *params, const char *format, ...)
768{
769        va_list args;
770
771        va_start (args, format);
772        if (params->error_func!=NULL)
773                params->error_func (params->data, format, args);
774        else
775	{
776                vfprintf (stderr, format, args);
777		fprintf (stderr,"\n");
778		fflush (stderr);
779	}
780        va_end (args);
781}
782
783
784/*
785 * ptp_read_func() and ptp_write_func() are
786 * based on same functions usb.c in libgphoto2.
787 * Much reading packet logs and having fun with trials and errors
788 * reveals that WMP / Windows is probably using an algorithm like this
789 * for large transfers:
790 *
791 * 1. Send the command (0x0c bytes) if headers are split, else, send
792 *    command plus sizeof(endpoint) - 0x0c bytes.
793 * 2. Send first packet, max size to be sizeof(endpoint) but only when using
794 *    split headers. Else goto 3.
795 * 3. REPEAT send 0x10000 byte chunks UNTIL remaining bytes < 0x10000
796 *    We call 0x10000 CONTEXT_BLOCK_SIZE.
797 * 4. Send remaining bytes MOD sizeof(endpoint)
798 * 5. Send remaining bytes. If this happens to be exactly sizeof(endpoint)
799 *    then also send a zero-length package.
800 *
801 * Further there is some special quirks to handle zero reads from the
802 * device, since some devices can't do them at all due to shortcomings
803 * of the USB slave controller in the device.
804 */
805#define CONTEXT_BLOCK_SIZE_1	0x3e00
806#define CONTEXT_BLOCK_SIZE_2  0x200
807#define CONTEXT_BLOCK_SIZE    CONTEXT_BLOCK_SIZE_1+CONTEXT_BLOCK_SIZE_2
808static short
809ptp_read_func (
810	unsigned long size, PTPDataHandler *handler,void *data,
811	unsigned long *readbytes,
812	int readzero
813) {
814  PTP_USB *ptp_usb = (PTP_USB *)data;
815  unsigned long toread = 0;
816  int result = 0;
817  unsigned long curread = 0;
818  unsigned long written;
819  unsigned char *bytes;
820  int expect_terminator_byte = 0;
821
822  // This is the largest block we'll need to read in.
823  bytes = malloc(CONTEXT_BLOCK_SIZE);
824  while (curread < size) {
825
826#ifdef ENABLE_USB_BULK_DEBUG
827    printf("Remaining size to read: 0x%04lx bytes\n", size - curread);
828#endif
829    // check equal to condition here
830    if (size - curread < CONTEXT_BLOCK_SIZE)
831    {
832      // this is the last packet
833      toread = size - curread;
834      // this is equivalent to zero read for these devices
835      if (readzero && FLAG_NO_ZERO_READS(ptp_usb) && toread % 64 == 0) {
836        toread += 1;
837        expect_terminator_byte = 1;
838      }
839    }
840    else if (curread == 0)
841      // we are first packet, but not last packet
842      toread = CONTEXT_BLOCK_SIZE_1;
843    else if (toread == CONTEXT_BLOCK_SIZE_1)
844      toread = CONTEXT_BLOCK_SIZE_2;
845    else if (toread == CONTEXT_BLOCK_SIZE_2)
846      toread = CONTEXT_BLOCK_SIZE_1;
847    else
848      printf("unexpected toread size 0x%04x, 0x%04x remaining bytes\n",
849	     (unsigned int) toread, (unsigned int) (size-curread));
850
851#ifdef ENABLE_USB_BULK_DEBUG
852    printf("Reading in 0x%04lx bytes\n", toread);
853#endif
854    result = USB_BULK_READ(ptp_usb->handle, ptp_usb->inep, (char*)bytes, toread, ptp_usb->timeout);
855#ifdef ENABLE_USB_BULK_DEBUG
856    printf("Result of read: 0x%04x\n", result);
857#endif
858
859    if (result < 0) {
860      return PTP_ERROR_IO;
861    }
862#ifdef ENABLE_USB_BULK_DEBUG
863    printf("<==USB IN\n");
864    if (result == 0)
865      printf("Zero Read\n");
866    else if (result < 0)
867      fprintf(stderr, "USB_BULK_READ result=%#x\n", result);
868    else
869      data_dump_ascii (stdout,bytes,result,16);
870#endif
871
872    // want to discard extra byte
873    if (expect_terminator_byte && result == toread)
874    {
875#ifdef ENABLE_USB_BULK_DEBUG
876      printf("<==USB IN\nDiscarding extra byte\n");
877#endif
878      result--;
879    }
880
881    int putfunc_ret = handler->putfunc(NULL, handler->priv, result, bytes, &written);
882    if (putfunc_ret != PTP_RC_OK)
883      return putfunc_ret;
884
885    ptp_usb->current_transfer_complete += result;
886    curread += result;
887
888    // Increase counters, call callback
889    if (ptp_usb->callback_active) {
890      if (ptp_usb->current_transfer_complete >= ptp_usb->current_transfer_total) {
891	// send last update and disable callback.
892	ptp_usb->current_transfer_complete = ptp_usb->current_transfer_total;
893	ptp_usb->callback_active = 0;
894      }
895      if (ptp_usb->current_transfer_callback != NULL) {
896	int ret;
897	ret = ptp_usb->current_transfer_callback(ptp_usb->current_transfer_complete,
898						 ptp_usb->current_transfer_total,
899						 ptp_usb->current_transfer_callback_data);
900	if (ret != 0) {
901	  return PTP_ERROR_CANCEL;
902	}
903      }
904    }
905
906    if (result < toread) /* short reads are common */
907      break;
908  }
909  if (readbytes) *readbytes = curread;
910  free (bytes);
911
912  // there might be a zero packet waiting for us...
913  if (readzero &&
914      !FLAG_NO_ZERO_READS(ptp_usb) &&
915      curread % ptp_usb->outep_maxpacket == 0) {
916    char temp;
917    int zeroresult = 0;
918
919#ifdef ENABLE_USB_BULK_DEBUG
920    printf("<==USB IN\n");
921    printf("Zero Read\n");
922#endif
923    zeroresult = USB_BULK_READ(ptp_usb->handle, ptp_usb->inep, &temp, 0, ptp_usb->timeout);
924    if (zeroresult != 0)
925      printf("LIBMTP panic: unable to read in zero packet, response 0x%04x", zeroresult);
926  }
927
928  return PTP_RC_OK;
929}
930
931static short
932ptp_write_func (
933        unsigned long   size,
934        PTPDataHandler  *handler,
935        void            *data,
936        unsigned long   *written
937) {
938  PTP_USB *ptp_usb = (PTP_USB *)data;
939  unsigned long towrite = 0;
940  int result = 0;
941  unsigned long curwrite = 0;
942  unsigned char *bytes;
943
944  // This is the largest block we'll need to read in.
945  bytes = malloc(CONTEXT_BLOCK_SIZE);
946  if (!bytes) {
947    return PTP_ERROR_IO;
948  }
949  while (curwrite < size) {
950    unsigned long usbwritten = 0;
951    towrite = size-curwrite;
952    if (towrite > CONTEXT_BLOCK_SIZE) {
953      towrite = CONTEXT_BLOCK_SIZE;
954    } else {
955      // This magic makes packets the same size that WMP send them.
956      if (towrite > ptp_usb->outep_maxpacket && towrite % ptp_usb->outep_maxpacket != 0) {
957        towrite -= towrite % ptp_usb->outep_maxpacket;
958      }
959    }
960    int getfunc_ret = handler->getfunc(NULL, handler->priv,towrite,bytes,&towrite);
961    if (getfunc_ret != PTP_RC_OK)
962      return getfunc_ret;
963    while (usbwritten < towrite) {
964	    result = USB_BULK_WRITE(ptp_usb->handle,ptp_usb->outep,((char*)bytes+usbwritten),towrite-usbwritten,ptp_usb->timeout);
965#ifdef ENABLE_USB_BULK_DEBUG
966	    printf("USB OUT==>\n");
967        if (result > 0) {
968            data_dump_ascii (stdout,bytes+usbwritten,result,16);
969        } else {
970            fprintf(stderr, "USB_BULK_WRITE: result=%#x\n", result);
971        }
972#endif
973	    if (result < 0) {
974	      return PTP_ERROR_IO;
975	    }
976	    // check for result == 0 perhaps too.
977	    // Increase counters
978	    ptp_usb->current_transfer_complete += result;
979	    curwrite += result;
980	    usbwritten += result;
981    }
982    // call callback
983    if (ptp_usb->callback_active) {
984      if (ptp_usb->current_transfer_complete >= ptp_usb->current_transfer_total) {
985	// send last update and disable callback.
986	ptp_usb->current_transfer_complete = ptp_usb->current_transfer_total;
987	ptp_usb->callback_active = 0;
988      }
989      if (ptp_usb->current_transfer_callback != NULL) {
990	int ret;
991	ret = ptp_usb->current_transfer_callback(ptp_usb->current_transfer_complete,
992						 ptp_usb->current_transfer_total,
993						 ptp_usb->current_transfer_callback_data);
994	if (ret != 0) {
995	  return PTP_ERROR_CANCEL;
996	}
997      }
998    }
999    if (result < towrite) /* short writes happen */
1000      break;
1001  }
1002  free (bytes);
1003  if (written) {
1004    *written = curwrite;
1005  }
1006
1007
1008  // If this is the last transfer send a zero write if required
1009  if (ptp_usb->current_transfer_complete >= ptp_usb->current_transfer_total) {
1010    if ((towrite % ptp_usb->outep_maxpacket) == 0) {
1011#ifdef ENABLE_USB_BULK_DEBUG
1012      printf("USB OUT==>\n");
1013      printf("Zero Write\n");
1014#endif
1015      result=USB_BULK_WRITE(ptp_usb->handle,ptp_usb->outep,(char *)"x",0,ptp_usb->timeout);
1016    }
1017  }
1018
1019  if (result < 0)
1020    return PTP_ERROR_IO;
1021  return PTP_RC_OK;
1022}
1023
1024/* memory data get/put handler */
1025typedef struct {
1026	unsigned char	*data;
1027	unsigned long	size, curoff;
1028} PTPMemHandlerPrivate;
1029
1030static uint16_t
1031memory_getfunc(PTPParams* params, void* private,
1032	       unsigned long wantlen, unsigned char *data,
1033	       unsigned long *gotlen
1034) {
1035	PTPMemHandlerPrivate* priv = (PTPMemHandlerPrivate*)private;
1036	unsigned long tocopy = wantlen;
1037
1038	if (priv->curoff + tocopy > priv->size)
1039		tocopy = priv->size - priv->curoff;
1040	memcpy (data, priv->data + priv->curoff, tocopy);
1041	priv->curoff += tocopy;
1042	*gotlen = tocopy;
1043	return PTP_RC_OK;
1044}
1045
1046static uint16_t
1047memory_putfunc(PTPParams* params, void* private,
1048	       unsigned long sendlen, unsigned char *data,
1049	       unsigned long *putlen
1050) {
1051	PTPMemHandlerPrivate* priv = (PTPMemHandlerPrivate*)private;
1052
1053	if (priv->curoff + sendlen > priv->size) {
1054		priv->data = realloc (priv->data, priv->curoff+sendlen);
1055		priv->size = priv->curoff + sendlen;
1056	}
1057	memcpy (priv->data + priv->curoff, data, sendlen);
1058	priv->curoff += sendlen;
1059	*putlen = sendlen;
1060	return PTP_RC_OK;
1061}
1062
1063/* init private struct for receiving data. */
1064static uint16_t
1065ptp_init_recv_memory_handler(PTPDataHandler *handler) {
1066	PTPMemHandlerPrivate* priv;
1067	priv = malloc (sizeof(PTPMemHandlerPrivate));
1068	handler->priv = priv;
1069	handler->getfunc = memory_getfunc;
1070	handler->putfunc = memory_putfunc;
1071	priv->data = NULL;
1072	priv->size = 0;
1073	priv->curoff = 0;
1074	return PTP_RC_OK;
1075}
1076
1077/* init private struct and put data in for sending data.
1078 * data is still owned by caller.
1079 */
1080static uint16_t
1081ptp_init_send_memory_handler(PTPDataHandler *handler,
1082	unsigned char *data, unsigned long len
1083) {
1084	PTPMemHandlerPrivate* priv;
1085	priv = malloc (sizeof(PTPMemHandlerPrivate));
1086	if (!priv)
1087		return PTP_RC_GeneralError;
1088	handler->priv = priv;
1089	handler->getfunc = memory_getfunc;
1090	handler->putfunc = memory_putfunc;
1091	priv->data = data;
1092	priv->size = len;
1093	priv->curoff = 0;
1094	return PTP_RC_OK;
1095}
1096
1097/* free private struct + data */
1098static uint16_t
1099ptp_exit_send_memory_handler (PTPDataHandler *handler) {
1100	PTPMemHandlerPrivate* priv = (PTPMemHandlerPrivate*)handler->priv;
1101	/* data is owned by caller */
1102	free (priv);
1103	return PTP_RC_OK;
1104}
1105
1106/* hand over our internal data to caller */
1107static uint16_t
1108ptp_exit_recv_memory_handler (PTPDataHandler *handler,
1109	unsigned char **data, unsigned long *size
1110) {
1111	PTPMemHandlerPrivate* priv = (PTPMemHandlerPrivate*)handler->priv;
1112	*data = priv->data;
1113	*size = priv->size;
1114	free (priv);
1115	return PTP_RC_OK;
1116}
1117
1118/* send / receive functions */
1119
1120uint16_t
1121ptp_usb_sendreq (PTPParams* params, PTPContainer* req)
1122{
1123	uint16_t ret;
1124	PTPUSBBulkContainer usbreq;
1125	PTPDataHandler	memhandler;
1126	unsigned long written = 0;
1127	unsigned long towrite;
1128#ifdef ENABLE_USB_BULK_DEBUG
1129	char txt[256];
1130
1131	(void) ptp_render_opcode (params, req->Code, sizeof(txt), txt);
1132	printf("REQUEST: 0x%04x, %s\n", req->Code, txt);
1133#endif
1134	/* build appropriate USB container */
1135	usbreq.length=htod32(PTP_USB_BULK_REQ_LEN-
1136		(sizeof(uint32_t)*(5-req->Nparam)));
1137	usbreq.type=htod16(PTP_USB_CONTAINER_COMMAND);
1138	usbreq.code=htod16(req->Code);
1139	usbreq.trans_id=htod32(req->Transaction_ID);
1140	usbreq.payload.params.param1=htod32(req->Param1);
1141	usbreq.payload.params.param2=htod32(req->Param2);
1142	usbreq.payload.params.param3=htod32(req->Param3);
1143	usbreq.payload.params.param4=htod32(req->Param4);
1144	usbreq.payload.params.param5=htod32(req->Param5);
1145	/* send it to responder */
1146	towrite = PTP_USB_BULK_REQ_LEN-(sizeof(uint32_t)*(5-req->Nparam));
1147	ptp_init_send_memory_handler (&memhandler, (unsigned char*)&usbreq, towrite);
1148	ret=ptp_write_func(
1149		towrite,
1150		&memhandler,
1151		params->data,
1152		&written
1153	);
1154	ptp_exit_send_memory_handler (&memhandler);
1155	if (ret!=PTP_RC_OK && ret!=PTP_ERROR_CANCEL) {
1156		ret = PTP_ERROR_IO;
1157	}
1158	if (written != towrite && ret != PTP_ERROR_CANCEL && ret != PTP_ERROR_IO) {
1159		libusb_glue_error (params,
1160			"PTP: request code 0x%04x sending req wrote only %ld bytes instead of %d",
1161			req->Code, written, towrite
1162		);
1163		ret = PTP_ERROR_IO;
1164	}
1165	return ret;
1166}
1167
1168uint16_t
1169ptp_usb_senddata (PTPParams* params, PTPContainer* ptp,
1170		  unsigned long size, PTPDataHandler *handler
1171) {
1172	uint16_t ret;
1173	int wlen, datawlen;
1174	unsigned long written;
1175	PTPUSBBulkContainer usbdata;
1176	uint32_t bytes_left_to_transfer;
1177	PTPDataHandler memhandler;
1178
1179#ifdef ENABLE_USB_BULK_DEBUG
1180	printf("SEND DATA PHASE\n");
1181#endif
1182	/* build appropriate USB container */
1183	usbdata.length	= htod32(PTP_USB_BULK_HDR_LEN+size);
1184	usbdata.type	= htod16(PTP_USB_CONTAINER_DATA);
1185	usbdata.code	= htod16(ptp->Code);
1186	usbdata.trans_id= htod32(ptp->Transaction_ID);
1187
1188	((PTP_USB*)params->data)->current_transfer_complete = 0;
1189	((PTP_USB*)params->data)->current_transfer_total = size+PTP_USB_BULK_HDR_LEN;
1190
1191	if (params->split_header_data) {
1192		datawlen = 0;
1193		wlen = PTP_USB_BULK_HDR_LEN;
1194	} else {
1195		unsigned long gotlen;
1196		/* For all camera devices. */
1197		datawlen = (size<PTP_USB_BULK_PAYLOAD_LEN_WRITE)?size:PTP_USB_BULK_PAYLOAD_LEN_WRITE;
1198		wlen = PTP_USB_BULK_HDR_LEN + datawlen;
1199
1200		ret = handler->getfunc(params, handler->priv, datawlen, usbdata.payload.data, &gotlen);
1201		if (ret != PTP_RC_OK)
1202			return ret;
1203		if (gotlen != datawlen)
1204			return PTP_RC_GeneralError;
1205	}
1206	ptp_init_send_memory_handler (&memhandler, (unsigned char *)&usbdata, wlen);
1207	/* send first part of data */
1208	ret = ptp_write_func(wlen, &memhandler, params->data, &written);
1209	ptp_exit_send_memory_handler (&memhandler);
1210	if (ret!=PTP_RC_OK) {
1211		return ret;
1212	}
1213	if (size <= datawlen) return ret;
1214	/* if everything OK send the rest */
1215	bytes_left_to_transfer = size-datawlen;
1216	ret = PTP_RC_OK;
1217	while(bytes_left_to_transfer > 0) {
1218		ret = ptp_write_func (bytes_left_to_transfer, handler, params->data, &written);
1219		if (ret != PTP_RC_OK)
1220			break;
1221		if (written == 0) {
1222			ret = PTP_ERROR_IO;
1223			break;
1224		}
1225		bytes_left_to_transfer -= written;
1226	}
1227	if (ret!=PTP_RC_OK && ret!=PTP_ERROR_CANCEL)
1228		ret = PTP_ERROR_IO;
1229	return ret;
1230}
1231
1232static uint16_t ptp_usb_getpacket(PTPParams *params,
1233		PTPUSBBulkContainer *packet, unsigned long *rlen)
1234{
1235	PTPDataHandler	memhandler;
1236	uint16_t	ret;
1237	unsigned char	*x = NULL;
1238
1239	/* read the header and potentially the first data */
1240	if (params->response_packet_size > 0) {
1241		/* If there is a buffered packet, just use it. */
1242		memcpy(packet, params->response_packet, params->response_packet_size);
1243		*rlen = params->response_packet_size;
1244		free(params->response_packet);
1245		params->response_packet = NULL;
1246		params->response_packet_size = 0;
1247		/* Here this signifies a "virtual read" */
1248		return PTP_RC_OK;
1249	}
1250	ptp_init_recv_memory_handler (&memhandler);
1251	ret = ptp_read_func(PTP_USB_BULK_HS_MAX_PACKET_LEN_READ, &memhandler, params->data, rlen, 0);
1252	ptp_exit_recv_memory_handler (&memhandler, &x, rlen);
1253	if (x) {
1254		memcpy (packet, x, *rlen);
1255		free (x);
1256	}
1257	return ret;
1258}
1259
1260uint16_t
1261ptp_usb_getdata (PTPParams* params, PTPContainer* ptp, PTPDataHandler *handler)
1262{
1263	uint16_t ret;
1264	PTPUSBBulkContainer usbdata;
1265	unsigned long	written;
1266	PTP_USB *ptp_usb = (PTP_USB *) params->data;
1267
1268#ifdef ENABLE_USB_BULK_DEBUG
1269	printf("GET DATA PHASE\n");
1270#endif
1271	memset(&usbdata,0,sizeof(usbdata));
1272	do {
1273		unsigned long len, rlen;
1274
1275		ret = ptp_usb_getpacket(params, &usbdata, &rlen);
1276		if (ret!=PTP_RC_OK) {
1277			ret = PTP_ERROR_IO;
1278			break;
1279		}
1280		if (dtoh16(usbdata.type)!=PTP_USB_CONTAINER_DATA) {
1281			ret = PTP_ERROR_DATA_EXPECTED;
1282			break;
1283		}
1284		if (dtoh16(usbdata.code)!=ptp->Code) {
1285			if (FLAG_IGNORE_HEADER_ERRORS(ptp_usb)) {
1286				libusb_glue_debug (params, "ptp2/ptp_usb_getdata: detected a broken "
1287					   "PTP header, code field insane, expect problems! (But continuing)");
1288				// Repair the header, so it won't wreak more havoc, don't just ignore it.
1289				// Typically these two fields will be broken.
1290				usbdata.code	 = htod16(ptp->Code);
1291				usbdata.trans_id = htod32(ptp->Transaction_ID);
1292				ret = PTP_RC_OK;
1293			} else {
1294				ret = dtoh16(usbdata.code);
1295				// This filters entirely insane garbage return codes, but still
1296				// makes it possible to return error codes in the code field when
1297				// getting data. It appears Windows ignores the contents of this
1298				// field entirely.
1299				if (ret < PTP_RC_Undefined || ret > PTP_RC_SpecificationOfDestinationUnsupported) {
1300					libusb_glue_debug (params, "ptp2/ptp_usb_getdata: detected a broken "
1301						   "PTP header, code field insane.");
1302					ret = PTP_ERROR_IO;
1303				}
1304				break;
1305			}
1306		}
1307		if (usbdata.length == 0xffffffffU) {
1308			/* Copy first part of data to 'data' */
1309      int putfunc_ret =
1310			handler->putfunc(
1311				params, handler->priv, rlen - PTP_USB_BULK_HDR_LEN, usbdata.payload.data,
1312				&written
1313			);
1314      if (putfunc_ret != PTP_RC_OK)
1315        return putfunc_ret;
1316			/* stuff data directly to passed data handler */
1317			while (1) {
1318				unsigned long readdata;
1319				uint16_t xret;
1320
1321				xret = ptp_read_func(
1322					PTP_USB_BULK_HS_MAX_PACKET_LEN_READ,
1323					handler,
1324					params->data,
1325					&readdata,
1326					0
1327				);
1328				if (xret != PTP_RC_OK)
1329					return xret;
1330				if (readdata < PTP_USB_BULK_HS_MAX_PACKET_LEN_READ)
1331					break;
1332			}
1333			return PTP_RC_OK;
1334		}
1335		if (rlen > dtoh32(usbdata.length)) {
1336			/*
1337			 * Buffer the surplus response packet if it is >=
1338			 * PTP_USB_BULK_HDR_LEN
1339			 * (i.e. it is probably an entire package)
1340			 * else discard it as erroneous surplus data.
1341			 * This will even work if more than 2 packets appear
1342			 * in the same transaction, they will just be handled
1343			 * iteratively.
1344			 *
1345			 * Marcus observed stray bytes on iRiver devices;
1346			 * these are still discarded.
1347			 */
1348			unsigned int packlen = dtoh32(usbdata.length);
1349			unsigned int surplen = rlen - packlen;
1350
1351			if (surplen >= PTP_USB_BULK_HDR_LEN) {
1352				params->response_packet = malloc(surplen);
1353				memcpy(params->response_packet,
1354				       (uint8_t *) &usbdata + packlen, surplen);
1355				params->response_packet_size = surplen;
1356			/* Ignore reading one extra byte if device flags have been set */
1357			} else if(!FLAG_NO_ZERO_READS(ptp_usb) &&
1358				  (rlen - dtoh32(usbdata.length) == 1)) {
1359			  libusb_glue_debug (params, "ptp2/ptp_usb_getdata: read %d bytes "
1360				     "too much, expect problems!",
1361				     rlen - dtoh32(usbdata.length));
1362			}
1363			rlen = packlen;
1364		}
1365
1366		/* For most PTP devices rlen is 512 == sizeof(usbdata)
1367		 * here. For MTP devices splitting header and data it might
1368		 * be 12.
1369		 */
1370		/* Evaluate full data length. */
1371		len=dtoh32(usbdata.length)-PTP_USB_BULK_HDR_LEN;
1372
1373		/* autodetect split header/data MTP devices */
1374		if (dtoh32(usbdata.length) > 12 && (rlen==12))
1375			params->split_header_data = 1;
1376
1377		/* Copy first part of data to 'data' */
1378    int putfunc_ret =
1379		handler->putfunc(
1380			params, handler->priv, rlen - PTP_USB_BULK_HDR_LEN, usbdata.payload.data,
1381			&written
1382		);
1383    if (putfunc_ret != PTP_RC_OK)
1384      return putfunc_ret;
1385
1386		if (FLAG_NO_ZERO_READS(ptp_usb) &&
1387		    len+PTP_USB_BULK_HDR_LEN == PTP_USB_BULK_HS_MAX_PACKET_LEN_READ) {
1388#ifdef ENABLE_USB_BULK_DEBUG
1389		  printf("Reading in extra terminating byte\n");
1390#endif
1391		  // need to read in extra byte and discard it
1392		  int result = 0;
1393		  char byte = 0;
1394                  result = USB_BULK_READ(ptp_usb->handle, ptp_usb->inep, &byte, 1, ptp_usb->timeout);
1395
1396		  if (result != 1)
1397		    printf("Could not read in extra byte for PTP_USB_BULK_HS_MAX_PACKET_LEN_READ long file, return value 0x%04x\n", result);
1398		} else if (len+PTP_USB_BULK_HDR_LEN == PTP_USB_BULK_HS_MAX_PACKET_LEN_READ && params->split_header_data == 0) {
1399		  int zeroresult = 0;
1400		  char zerobyte = 0;
1401
1402#ifdef ENABLE_USB_BULK_DEBUG
1403		  printf("Reading in zero packet after header\n");
1404#endif
1405                  zeroresult = USB_BULK_READ(ptp_usb->handle, ptp_usb->inep, &zerobyte, 0, ptp_usb->timeout);
1406
1407		  if (zeroresult != 0)
1408		    printf("LIBMTP panic: unable to read in zero packet, response 0x%04x", zeroresult);
1409		}
1410
1411		/* Is that all of data? */
1412		if (len+PTP_USB_BULK_HDR_LEN<=rlen) {
1413		  break;
1414		}
1415
1416		ret = ptp_read_func(len - (rlen - PTP_USB_BULK_HDR_LEN),
1417				    handler,
1418				    params->data, &rlen, 1);
1419
1420		if (ret!=PTP_RC_OK) {
1421		  break;
1422		}
1423	} while (0);
1424	return ret;
1425}
1426
1427uint16_t
1428ptp_usb_getresp (PTPParams* params, PTPContainer* resp)
1429{
1430	uint16_t ret;
1431	unsigned long rlen;
1432	PTPUSBBulkContainer usbresp;
1433	PTP_USB *ptp_usb = (PTP_USB *)(params->data);
1434
1435#ifdef ENABLE_USB_BULK_DEBUG
1436	printf("RESPONSE: ");
1437#endif
1438	memset(&usbresp,0,sizeof(usbresp));
1439	/* read response, it should never be longer than sizeof(usbresp) */
1440	ret = ptp_usb_getpacket(params, &usbresp, &rlen);
1441
1442	// Fix for bevahiour reported by Scott Snyder on Samsung YP-U3. The player
1443	// sends a packet containing just zeroes of length 2 (up to 4 has been seen too)
1444	// after a NULL packet when it should send the response. This code ignores
1445	// such illegal packets.
1446	while (ret==PTP_RC_OK && rlen<PTP_USB_BULK_HDR_LEN && usbresp.length==0) {
1447	  libusb_glue_debug (params, "ptp_usb_getresp: detected short response "
1448		     "of %d bytes, expect problems! (re-reading "
1449		     "response), rlen");
1450	  ret = ptp_usb_getpacket(params, &usbresp, &rlen);
1451	}
1452
1453	if (ret!=PTP_RC_OK) {
1454		ret = PTP_ERROR_IO;
1455	} else
1456	if (dtoh16(usbresp.type)!=PTP_USB_CONTAINER_RESPONSE) {
1457		ret = PTP_ERROR_RESP_EXPECTED;
1458	} else
1459	if (dtoh16(usbresp.code)!=resp->Code) {
1460		ret = dtoh16(usbresp.code);
1461	}
1462#ifdef ENABLE_USB_BULK_DEBUG
1463	printf("%04x\n", ret);
1464#endif
1465	if (ret!=PTP_RC_OK) {
1466/*		libusb_glue_error (params,
1467		"PTP: request code 0x%04x getting resp error 0x%04x",
1468			resp->Code, ret);*/
1469		return ret;
1470	}
1471	/* build an appropriate PTPContainer */
1472	resp->Code=dtoh16(usbresp.code);
1473	resp->SessionID=params->session_id;
1474	resp->Transaction_ID=dtoh32(usbresp.trans_id);
1475	if (FLAG_IGNORE_HEADER_ERRORS(ptp_usb)) {
1476		if (resp->Transaction_ID != params->transaction_id-1) {
1477			libusb_glue_debug (params, "ptp_usb_getresp: detected a broken "
1478				   "PTP header, transaction ID insane, expect "
1479				   "problems! (But continuing)");
1480			// Repair the header, so it won't wreak more havoc.
1481			resp->Transaction_ID = params->transaction_id-1;
1482		}
1483	}
1484	resp->Param1=dtoh32(usbresp.payload.params.param1);
1485	resp->Param2=dtoh32(usbresp.payload.params.param2);
1486	resp->Param3=dtoh32(usbresp.payload.params.param3);
1487	resp->Param4=dtoh32(usbresp.payload.params.param4);
1488	resp->Param5=dtoh32(usbresp.payload.params.param5);
1489	return ret;
1490}
1491
1492/* Event handling functions */
1493
1494/* PTP Events wait for or check mode */
1495#define PTP_EVENT_CHECK			0x0000	/* waits for */
1496#define PTP_EVENT_CHECK_FAST		0x0001	/* checks */
1497
1498static inline uint16_t
1499ptp_usb_event (PTPParams* params, PTPContainer* event, int wait)
1500{
1501	uint16_t ret;
1502	int result;
1503	unsigned long rlen;
1504	PTPUSBEventContainer usbevent;
1505	PTP_USB *ptp_usb = (PTP_USB *)(params->data);
1506
1507	memset(&usbevent,0,sizeof(usbevent));
1508
1509	if ((params==NULL) || (event==NULL))
1510		return PTP_ERROR_BADPARAM;
1511	ret = PTP_RC_OK;
1512	switch(wait) {
1513	case PTP_EVENT_CHECK:
1514                result=USB_BULK_READ(ptp_usb->handle, ptp_usb->intep,(char *)&usbevent,sizeof(usbevent),ptp_usb->timeout);
1515		if (result==0)
1516                        result = USB_BULK_READ(ptp_usb->handle, ptp_usb->intep,(char *) &usbevent, sizeof(usbevent), ptp_usb->timeout);
1517		if (result < 0) ret = PTP_ERROR_IO;
1518		break;
1519	case PTP_EVENT_CHECK_FAST:
1520                result=USB_BULK_READ(ptp_usb->handle, ptp_usb->intep,(char *)&usbevent,sizeof(usbevent),ptp_usb->timeout);
1521		if (result==0)
1522                        result = USB_BULK_READ(ptp_usb->handle, ptp_usb->intep,(char *) &usbevent, sizeof(usbevent), ptp_usb->timeout);
1523		if (result < 0) ret = PTP_ERROR_IO;
1524		break;
1525	default:
1526		ret=PTP_ERROR_BADPARAM;
1527		break;
1528	}
1529	if (ret!=PTP_RC_OK) {
1530		libusb_glue_error (params,
1531			"PTP: reading event an error 0x%04x occurred", ret);
1532		return PTP_ERROR_IO;
1533	}
1534	rlen = result;
1535	if (rlen < 8) {
1536		libusb_glue_error (params,
1537			"PTP: reading event an short read of %ld bytes occurred", rlen);
1538		return PTP_ERROR_IO;
1539	}
1540	/* if we read anything over interrupt endpoint it must be an event */
1541	/* build an appropriate PTPContainer */
1542	event->Code=dtoh16(usbevent.code);
1543	event->SessionID=params->session_id;
1544	event->Transaction_ID=dtoh32(usbevent.trans_id);
1545	event->Param1=dtoh32(usbevent.param1);
1546	event->Param2=dtoh32(usbevent.param2);
1547	event->Param3=dtoh32(usbevent.param3);
1548	return ret;
1549}
1550
1551uint16_t
1552ptp_usb_event_check (PTPParams* params, PTPContainer* event) {
1553
1554	return ptp_usb_event (params, event, PTP_EVENT_CHECK_FAST);
1555}
1556
1557uint16_t
1558ptp_usb_event_wait (PTPParams* params, PTPContainer* event) {
1559
1560	return ptp_usb_event (params, event, PTP_EVENT_CHECK);
1561}
1562
1563uint16_t
1564ptp_usb_control_cancel_request (PTPParams *params, uint32_t transactionid) {
1565	PTP_USB *ptp_usb = (PTP_USB *)(params->data);
1566	int ret;
1567	unsigned char buffer[6];
1568
1569	htod16a(&buffer[0],PTP_EC_CancelTransaction);
1570	htod32a(&buffer[2],transactionid);
1571	ret = usb_control_msg(ptp_usb->handle,
1572			      USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1573                              0x64, 0x0000, 0x0000, (char *) buffer, sizeof(buffer), ptp_usb->timeout);
1574	if (ret < sizeof(buffer))
1575		return PTP_ERROR_IO;
1576	return PTP_RC_OK;
1577}
1578
1579static int init_ptp_usb (PTPParams* params, PTP_USB* ptp_usb, struct usb_device* dev)
1580{
1581  usb_dev_handle *device_handle;
1582
1583  params->sendreq_func=ptp_usb_sendreq;
1584  params->senddata_func=ptp_usb_senddata;
1585  params->getresp_func=ptp_usb_getresp;
1586  params->getdata_func=ptp_usb_getdata;
1587  params->cancelreq_func=ptp_usb_control_cancel_request;
1588  params->data=ptp_usb;
1589  params->transaction_id=0;
1590  /*
1591   * This is hardcoded here since we have no devices whatsoever that are BE.
1592   * Change this the day we run into our first BE device (if ever).
1593   */
1594  params->byteorder = PTP_DL_LE;
1595
1596  ptp_usb->timeout = USB_TIMEOUT_DEFAULT;
1597
1598  device_handle = usb_open(dev);
1599  if (!device_handle) {
1600    perror("usb_open()");
1601    return -1;
1602  }
1603
1604  ptp_usb->handle = device_handle;
1605#ifdef LIBUSB_HAS_DETACH_KERNEL_DRIVER_NP
1606  /*
1607  * If this device is known to be wrongfully claimed by other kernel
1608  * drivers (such as mass storage), then try to unload it to make it
1609  * accessible from user space.
1610  */
1611  if (FLAG_UNLOAD_DRIVER(ptp_usb)) {
1612    if (usb_detach_kernel_driver_np(device_handle, (int) ptp_usb->interface)) {
1613	  // Totally ignore this error!
1614	  // perror("usb_detach_kernel_driver_np()");
1615    }
1616  }
1617#endif
1618#ifdef __WIN32__
1619  // Only needed on Windows, and cause problems on other platforms.
1620  if (usb_set_configuration(device_handle, dev->config->bConfigurationValue)) {
1621    perror("usb_set_configuration()");
1622    return -1;
1623  }
1624#endif
1625  if (usb_claim_interface(device_handle, (int) ptp_usb->interface)) {
1626    perror("usb_claim_interface()");
1627    return -1;
1628  }
1629
1630  return 0;
1631}
1632
1633static void clear_stall(PTP_USB* ptp_usb)
1634{
1635  uint16_t status;
1636  int ret;
1637
1638  /* check the inep status */
1639  status = 0;
1640  ret = usb_get_endpoint_status(ptp_usb,ptp_usb->inep,&status);
1641  if (ret<0) {
1642    perror ("inep: usb_get_endpoint_status()");
1643  } else if (status) {
1644    printf("Clearing stall on IN endpoint\n");
1645    ret = usb_clear_stall_feature(ptp_usb,ptp_usb->inep);
1646    if (ret<0) {
1647      perror ("usb_clear_stall_feature()");
1648    }
1649  }
1650
1651  /* check the outep status */
1652  status=0;
1653  ret = usb_get_endpoint_status(ptp_usb,ptp_usb->outep,&status);
1654  if (ret<0) {
1655    perror("outep: usb_get_endpoint_status()");
1656  } else if (status) {
1657    printf("Clearing stall on OUT endpoint\n");
1658    ret = usb_clear_stall_feature(ptp_usb,ptp_usb->outep);
1659    if (ret<0) {
1660      perror("usb_clear_stall_feature()");
1661    }
1662  }
1663
1664  /* TODO: do we need this for INTERRUPT (ptp_usb->intep) too? */
1665}
1666
1667static void clear_halt(PTP_USB* ptp_usb)
1668{
1669  int ret;
1670
1671  ret = usb_clear_halt(ptp_usb->handle,ptp_usb->inep);
1672  if (ret<0) {
1673    perror("usb_clear_halt() on IN endpoint");
1674  }
1675  ret = usb_clear_halt(ptp_usb->handle,ptp_usb->outep);
1676  if (ret<0) {
1677    perror("usb_clear_halt() on OUT endpoint");
1678  }
1679  ret = usb_clear_halt(ptp_usb->handle,ptp_usb->intep);
1680  if (ret<0) {
1681    perror("usb_clear_halt() on INTERRUPT endpoint");
1682  }
1683}
1684
1685static void close_usb(PTP_USB* ptp_usb)
1686{
1687  // Commented out since it was confusing some
1688  // devices to do these things.
1689  if (!FLAG_NO_RELEASE_INTERFACE(ptp_usb)) {
1690
1691    /*
1692     * Clear any stalled endpoints
1693     * On misbehaving devices designed for Windows/Mac, quote from:
1694     * http://www2.one-eyed-alien.net/~mdharm/linux-usb/target_offenses.txt
1695     * Device does Bad Things(tm) when it gets a GET_STATUS after CLEAR_HALT
1696     * (...) Windows, when clearing a stall, only sends the CLEAR_HALT command,
1697     * and presumes that the stall has cleared.  Some devices actually choke
1698     * if the CLEAR_HALT is followed by a GET_STATUS (used to determine if the
1699     * STALL is persistant or not).
1700     */
1701    clear_stall(ptp_usb);
1702    // Clear halts on any endpoints
1703    clear_halt(ptp_usb);
1704    // Added to clear some stuff on the OUT endpoint
1705    // TODO: is this good on the Mac too?
1706    // HINT: some devices may need that you comment these two out too.
1707    usb_resetep(ptp_usb->handle, ptp_usb->outep);
1708    usb_release_interface(ptp_usb->handle, (int) ptp_usb->interface);
1709  }
1710
1711  usb_close(ptp_usb->handle);
1712}
1713
1714/**
1715 * Self-explanatory?
1716 */
1717static void find_interface_and_endpoints(struct usb_device *dev,
1718					 uint8_t *interface,
1719					 int* inep,
1720					 int* inep_maxpacket,
1721					 int* outep,
1722					 int *outep_maxpacket,
1723					 int* intep)
1724{
1725  int i;
1726
1727  // Loop over the device configurations
1728  for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
1729    uint8_t j;
1730
1731    for (j = 0; j < dev->config[i].bNumInterfaces; j++) {
1732      uint8_t k;
1733      uint8_t no_ep;
1734      struct usb_endpoint_descriptor *ep;
1735
1736      if (dev->descriptor.bNumConfigurations > 1 || dev->config[i].bNumInterfaces > 1) {
1737	// OK This device has more than one interface, so we have to find out
1738	// which one to use!
1739	// FIXME: Probe the interface.
1740	// FIXME: Release modules attached to all other interfaces in Linux...?
1741      }
1742
1743      *interface = dev->config[i].interface[j].altsetting->bInterfaceNumber;
1744      ep = dev->config[i].interface[j].altsetting->endpoint;
1745      no_ep = dev->config[i].interface[j].altsetting->bNumEndpoints;
1746
1747      for (k = 0; k < no_ep; k++) {
1748	if (ep[k].bmAttributes==USB_ENDPOINT_TYPE_BULK)	{
1749	  if ((ep[k].bEndpointAddress&USB_ENDPOINT_DIR_MASK)==
1750	      USB_ENDPOINT_DIR_MASK)
1751	    {
1752	      *inep=ep[k].bEndpointAddress;
1753	      *inep_maxpacket=ep[k].wMaxPacketSize;
1754	    }
1755	  if ((ep[k].bEndpointAddress&USB_ENDPOINT_DIR_MASK)==0)
1756	    {
1757	      *outep=ep[k].bEndpointAddress;
1758	      *outep_maxpacket=ep[k].wMaxPacketSize;
1759	    }
1760	} else if (ep[k].bmAttributes==USB_ENDPOINT_TYPE_INTERRUPT){
1761	  if ((ep[k].bEndpointAddress&USB_ENDPOINT_DIR_MASK)==
1762	      USB_ENDPOINT_DIR_MASK)
1763	    {
1764	      *intep=ep[k].bEndpointAddress;
1765	    }
1766	}
1767      }
1768      // We assigned the endpoints so return here.
1769      return;
1770    }
1771  }
1772}
1773
1774/**
1775 * This function assigns params and usbinfo given a raw device
1776 * as input.
1777 * @param device the device to be assigned.
1778 * @param usbinfo a pointer to the new usbinfo.
1779 * @return an error code.
1780 */
1781LIBMTP_error_number_t configure_usb_device(LIBMTP_raw_device_t *device,
1782					   PTPParams *params,
1783					   void **usbinfo)
1784{
1785  PTP_USB *ptp_usb;
1786  struct usb_device *libusb_device;
1787  uint16_t ret = 0;
1788  struct usb_bus *bus;
1789  int found = 0;
1790
1791  /* See if we can find this raw device again... */
1792  bus = init_usb();
1793  for (; bus != NULL; bus = bus->next) {
1794    if (bus->location == device->bus_location) {
1795      struct usb_device *dev = bus->devices;
1796
1797      for (; dev != NULL; dev = dev->next) {
1798	if(dev->devnum == device->devnum &&
1799	   dev->descriptor.idVendor == device->device_entry.vendor_id &&
1800	   dev->descriptor.idProduct == device->device_entry.product_id ) {
1801	  libusb_device = dev;
1802	  found = 1;
1803	  break;
1804	}
1805      }
1806      if (found)
1807	break;
1808    }
1809  }
1810  /* Device has gone since detecting raw devices! */
1811  if (!found) {
1812    return LIBMTP_ERROR_NO_DEVICE_ATTACHED;
1813  }
1814
1815  /* Allocate structs */
1816  ptp_usb = (PTP_USB *) malloc(sizeof(PTP_USB));
1817  if (ptp_usb == NULL) {
1818    return LIBMTP_ERROR_MEMORY_ALLOCATION;
1819  }
1820  /* Start with a blank slate (includes setting device_flags to 0) */
1821  memset(ptp_usb, 0, sizeof(PTP_USB));
1822
1823  /* Copy the raw device */
1824  memcpy(&ptp_usb->rawdevice, device, sizeof(LIBMTP_raw_device_t));
1825
1826  /*
1827   * Some devices must have their "OS Descriptor" massaged in order
1828   * to work.
1829   */
1830  if (FLAG_ALWAYS_PROBE_DESCRIPTOR(ptp_usb)) {
1831    // Massage the device descriptor
1832    (void) probe_device_descriptor(libusb_device, NULL);
1833  }
1834
1835
1836  /* Assign endpoints to usbinfo... */
1837  find_interface_and_endpoints(libusb_device,
1838		   &ptp_usb->interface,
1839		   &ptp_usb->inep,
1840		   &ptp_usb->inep_maxpacket,
1841		   &ptp_usb->outep,
1842		   &ptp_usb->outep_maxpacket,
1843		   &ptp_usb->intep);
1844
1845  /* Attempt to initialize this device */
1846  if (init_ptp_usb(params, ptp_usb, libusb_device) < 0) {
1847    fprintf(stderr, "LIBMTP PANIC: Unable to initialize device\n");
1848    return LIBMTP_ERROR_CONNECTING;
1849  }
1850
1851  /*
1852   * This works in situations where previous bad applications
1853   * have not used LIBMTP_Release_Device on exit
1854   */
1855  if ((ret = ptp_opensession(params, 1)) == PTP_ERROR_IO) {
1856    fprintf(stderr, "PTP_ERROR_IO: Trying again after re-initializing USB interface\n");
1857    close_usb(ptp_usb);
1858
1859    if(init_ptp_usb(params, ptp_usb, libusb_device) <0) {
1860      fprintf(stderr, "LIBMTP PANIC: Could not open session on device\n");
1861      return LIBMTP_ERROR_CONNECTING;
1862    }
1863
1864    /* Device has been reset, try again */
1865    ret = ptp_opensession(params, 1);
1866  }
1867
1868  /* Was the transaction id invalid? Try again */
1869  if (ret == PTP_RC_InvalidTransactionID) {
1870    fprintf(stderr, "LIBMTP WARNING: Transaction ID was invalid, increment and try again\n");
1871    params->transaction_id += 10;
1872    ret = ptp_opensession(params, 1);
1873  }
1874
1875  if (ret != PTP_RC_SessionAlreadyOpened && ret != PTP_RC_OK) {
1876    fprintf(stderr, "LIBMTP PANIC: Could not open session! "
1877	    "(Return code %d)\n  Try to reset the device.\n",
1878	    ret);
1879    usb_release_interface(ptp_usb->handle,
1880			  (int) ptp_usb->interface);
1881    return LIBMTP_ERROR_CONNECTING;
1882  }
1883
1884  /* OK configured properly */
1885  *usbinfo = (void *) ptp_usb;
1886  return LIBMTP_ERROR_NONE;
1887}
1888
1889
1890void close_device (PTP_USB *ptp_usb, PTPParams *params)
1891{
1892  if (ptp_closesession(params)!=PTP_RC_OK)
1893    fprintf(stderr,"ERROR: Could not close session!\n");
1894  close_usb(ptp_usb);
1895}
1896
1897void set_usb_device_timeout(PTP_USB *ptp_usb, int timeout)
1898{
1899    ptp_usb->timeout = timeout;
1900}
1901
1902void get_usb_device_timeout(PTP_USB *ptp_usb, int *timeout)
1903{
1904    *timeout = ptp_usb->timeout;
1905}
1906
1907static int usb_clear_stall_feature(PTP_USB* ptp_usb, int ep)
1908{
1909
1910  return (usb_control_msg(ptp_usb->handle,
1911			  USB_RECIP_ENDPOINT, USB_REQ_CLEAR_FEATURE, USB_FEATURE_HALT,
1912                          ep, NULL, 0, ptp_usb->timeout));
1913}
1914
1915static int usb_get_endpoint_status(PTP_USB* ptp_usb, int ep, uint16_t* status)
1916{
1917  return (usb_control_msg(ptp_usb->handle,
1918			  USB_DP_DTH|USB_RECIP_ENDPOINT, USB_REQ_GET_STATUS,
1919                          USB_FEATURE_HALT, ep, (char *)status, 2, ptp_usb->timeout));
1920}
1921