hw/usb/dev-mtp.c

   1 /*
   2  * Media Transfer Protocol implementation, backed by host filesystem.
   3  *
   4  * Copyright Red Hat, Inc 2014
   5  *
   6  * Author:
   7  *   Gerd Hoffmann <[email protected]>
   8  *
   9  * This code is licensed under the GPL v2 or later.
  10  */
  11
  12 #include "qemu/osdep.h"
  13 #include "qemu-common.h"
  14 #include "qapi/error.h"
  15 #include "qemu/error-report.h"
  16 #include <wchar.h>
  17 #include <dirent.h>
  18
  19 #include <sys/statvfs.h>
  20
  21
  22 #include "qemu/iov.h"
  23 #include "qemu/module.h"
  24 #include "qemu/filemonitor.h"
  25 #include "trace.h"
  26 #include "hw/qdev-properties.h"
  27 #include "hw/usb.h"
  28 #include "migration/vmstate.h"
  29 #include "desc.h"
  30 #include "qemu/units.h"
  31
  32 /* ----------------------------------------------------------------------- */
  33
  34 enum mtp_container_type {
  35     TYPE_COMMAND  = 1,
  36     TYPE_DATA     = 2,
  37     TYPE_RESPONSE = 3,
  38     TYPE_EVENT    = 4,
  39 };
  40
  41 /* MTP write stage, for internal use only */
  42 enum mtp_write_status {
  43     WRITE_START    = 1,
  44     WRITE_CONTINUE = 2,
  45     WRITE_END      = 3,
  46 };
  47
  48 enum mtp_code {
  49     /* command codes */
  50     CMD_GET_DEVICE_INFO            = 0x1001,
  51     CMD_OPEN_SESSION               = 0x1002,
  52     CMD_CLOSE_SESSION              = 0x1003,
  53     CMD_GET_STORAGE_IDS            = 0x1004,
  54     CMD_GET_STORAGE_INFO           = 0x1005,
  55     CMD_GET_NUM_OBJECTS            = 0x1006,
  56     CMD_GET_OBJECT_HANDLES         = 0x1007,
  57     CMD_GET_OBJECT_INFO            = 0x1008,
  58     CMD_GET_OBJECT                 = 0x1009,
  59     CMD_DELETE_OBJECT              = 0x100b,
  60     CMD_SEND_OBJECT_INFO           = 0x100c,
  61     CMD_SEND_OBJECT                = 0x100d,
  62     CMD_GET_PARTIAL_OBJECT         = 0x101b,
  63     CMD_GET_OBJECT_PROPS_SUPPORTED = 0x9801,
  64     CMD_GET_OBJECT_PROP_DESC       = 0x9802,
  65     CMD_GET_OBJECT_PROP_VALUE      = 0x9803,
  66
  67     /* response codes */
  68     RES_OK                         = 0x2001,
  69     RES_GENERAL_ERROR              = 0x2002,
  70     RES_SESSION_NOT_OPEN           = 0x2003,
  71     RES_INVALID_TRANSACTION_ID     = 0x2004,
  72     RES_OPERATION_NOT_SUPPORTED    = 0x2005,
  73     RES_PARAMETER_NOT_SUPPORTED    = 0x2006,
  74     RES_INCOMPLETE_TRANSFER        = 0x2007,
  75     RES_INVALID_STORAGE_ID         = 0x2008,
  76     RES_INVALID_OBJECT_HANDLE      = 0x2009,
  77     RES_INVALID_OBJECT_FORMAT_CODE = 0x200b,
  78     RES_STORE_FULL                 = 0x200c,
  79     RES_STORE_READ_ONLY            = 0x200e,
  80     RES_PARTIAL_DELETE             = 0x2012,
  81     RES_STORE_NOT_AVAILABLE        = 0x2013,
  82     RES_SPEC_BY_FORMAT_UNSUPPORTED = 0x2014,
  83     RES_INVALID_OBJECTINFO         = 0x2015,
  84     RES_DESTINATION_UNSUPPORTED    = 0x2020,
  85     RES_INVALID_PARENT_OBJECT      = 0x201a,
  86     RES_INVALID_PARAMETER          = 0x201d,
  87     RES_SESSION_ALREADY_OPEN       = 0x201e,
  88     RES_INVALID_OBJECT_PROP_CODE   = 0xA801,
  89
  90     /* format codes */
  91     FMT_UNDEFINED_OBJECT           = 0x3000,
  92     FMT_ASSOCIATION                = 0x3001,
  93
  94     /* event codes */
  95     EVT_CANCEL_TRANSACTION         = 0x4001,
  96     EVT_OBJ_ADDED                  = 0x4002,
  97     EVT_OBJ_REMOVED                = 0x4003,
  98     EVT_OBJ_INFO_CHANGED           = 0x4007,
  99
 100     /* object properties */
 101     PROP_STORAGE_ID                = 0xDC01,
 102     PROP_OBJECT_FORMAT             = 0xDC02,
 103     PROP_OBJECT_COMPRESSED_SIZE    = 0xDC04,
 104     PROP_PARENT_OBJECT             = 0xDC0B,
 105     PROP_PERSISTENT_UNIQUE_OBJECT_IDENTIFIER = 0xDC41,
 106     PROP_NAME                      = 0xDC44,
 107 };
 108
 109 enum mtp_data_type {
 110     DATA_TYPE_UINT16  = 0x0004,
 111     DATA_TYPE_UINT32  = 0x0006,
 112     DATA_TYPE_UINT64  = 0x0008,
 113     DATA_TYPE_UINT128 = 0x000a,
 114     DATA_TYPE_STRING  = 0xffff,
 115 };
 116
 117 typedef struct {
 118     uint32_t length;
 119     uint16_t type;
 120     uint16_t code;
 121     uint32_t trans;
 122 } QEMU_PACKED mtp_container;
 123
 124 /* ----------------------------------------------------------------------- */
 125
 126 typedef struct MTPState MTPState;
 127 typedef struct MTPControl MTPControl;
 128 typedef struct MTPData MTPData;
 129 typedef struct MTPObject MTPObject;
 130
 131 enum {
 132     EP_DATA_IN = 1,
 133     EP_DATA_OUT,
 134     EP_EVENT,
 135 };
 136
 137 typedef struct MTPMonEntry MTPMonEntry;
 138
 139 struct MTPMonEntry {
 140     uint32_t event;
 141     uint32_t handle;
 142
 143     QTAILQ_ENTRY(MTPMonEntry) next;
 144 };
 145
 146 struct MTPControl {
 147     uint16_t     code;
 148     uint32_t     trans;
 149     int          argc;
 150     uint32_t     argv[5];
 151 };
 152
 153 struct MTPData {
 154     uint16_t     code;
 155     uint32_t     trans;
 156     uint64_t     offset;
 157     uint64_t     length;
 158     uint64_t     alloc;
 159     uint8_t      *data;
 160     bool         first;
 161     /* Used for >4G file sizes */
 162     bool         pending;
 163     int          fd;
 164     uint8_t      write_status;
 165     /* Internal pointer per every MTP_WRITE_BUF_SZ */
 166     uint64_t     data_offset;
 167 };
 168
 169 struct MTPObject {
 170     uint32_t     handle;
 171     uint16_t     format;
 172     char         *name;
 173     char         *path;
 174     struct stat  stat;
 175     /* file monitor watch id */
 176     int64_t      watchid;
 177     MTPObject    *parent;
 178     uint32_t     nchildren;
 179     QLIST_HEAD(, MTPObject) children;
 180     QLIST_ENTRY(MTPObject) list;
 181     bool         have_children;
 182     QTAILQ_ENTRY(MTPObject) next;
 183 };
 184
 185 struct MTPState {
 186     USBDevice    dev;
 187     char         *root;
 188     char         *desc;
 189     uint32_t     flags;
 190
 191     MTPData      *data_in;
 192     MTPData      *data_out;
 193     MTPControl   *result;
 194     uint32_t     session;
 195     uint32_t     next_handle;
 196     bool         readonly;
 197
 198     QTAILQ_HEAD(, MTPObject) objects;
 199     QFileMonitor *file_monitor;
 200     QTAILQ_HEAD(, MTPMonEntry) events;
 201     /* Responder is expecting a write operation */
 202     bool write_pending;
 203     struct {
 204         uint32_t parent_handle;
 205         uint16_t format;
 206         uint32_t size;
 207         char *filename;
 208     } dataset;
 209 };
 210
 211 /*
 212  * ObjectInfo dataset received from initiator
 213  * Fields we don't care about are ignored
 214  */
 215 typedef struct {
 216     uint32_t storage_id; /*unused*/
 217     uint16_t format;
 218     uint16_t protection_status; /*unused*/
 219     uint32_t size;
 220     uint16_t thumb_format; /*unused*/
 221     uint32_t thumb_comp_sz; /*unused*/
 222     uint32_t thumb_pix_width; /*unused*/
 223     uint32_t thumb_pix_height; /*unused*/
 224     uint32_t image_pix_width; /*unused*/
 225     uint32_t image_pix_height; /*unused*/
 226     uint32_t image_bit_depth; /*unused*/
 227     uint32_t parent; /*unused*/
 228     uint16_t assoc_type;
 229     uint32_t assoc_desc;
 230     uint32_t seq_no; /*unused*/
 231     uint8_t length; /*part of filename field*/
 232     uint8_t filename[0]; /* UTF-16 encoded */
 233     char date_created[0]; /*unused*/
 234     char date_modified[0]; /*unused*/
 235     char keywords[0]; /*unused*/
 236     /* string and other data follows */
 237 } QEMU_PACKED ObjectInfo;
 238
 239 #define TYPE_USB_MTP "usb-mtp"
 240 #define USB_MTP(obj) OBJECT_CHECK(MTPState, (obj), TYPE_USB_MTP)
 241
 242 #define QEMU_STORAGE_ID 0x00010001
 243
 244 #define MTP_FLAG_WRITABLE 0
 245
 246 #define FLAG_SET(_mtp, _flag)  ((_mtp)->flags & (1 << (_flag)))
 247
 248 /* ----------------------------------------------------------------------- */
 249
 250 #define MTP_MANUFACTURER  "QEMU"
 251 #define MTP_PRODUCT       "QEMU filesharing"
 252 #define MTP_WRITE_BUF_SZ  (512 * KiB)
 253
 254 enum {
 255     STR_MANUFACTURER = 1,
 256     STR_PRODUCT,
 257     STR_SERIALNUMBER,
 258     STR_MTP,
 259     STR_CONFIG_FULL,
 260     STR_CONFIG_HIGH,
 261     STR_CONFIG_SUPER,
 262 };
 263
 264 static const USBDescStrings desc_strings = {
 265     [STR_MANUFACTURER] = MTP_MANUFACTURER,
 266     [STR_PRODUCT]      = MTP_PRODUCT,
 267     [STR_SERIALNUMBER] = "34617",
 268     [STR_MTP]          = "MTP",
 269     [STR_CONFIG_FULL]  = "Full speed config (usb 1.1)",
 270     [STR_CONFIG_HIGH]  = "High speed config (usb 2.0)",
 271     [STR_CONFIG_SUPER] = "Super speed config (usb 3.0)",
 272 };
 273
 274 static const USBDescIface desc_iface_full = {
 275     .bInterfaceNumber              = 0,
 276     .bNumEndpoints                 = 3,
 277     .bInterfaceClass               = USB_CLASS_STILL_IMAGE,
 278     .bInterfaceSubClass            = 0x01,
 279     .bInterfaceProtocol            = 0x01,
 280     .iInterface                    = STR_MTP,
 281     .eps = (USBDescEndpoint[]) {
 282         {
 283             .bEndpointAddress      = USB_DIR_IN | EP_DATA_IN,
 284             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
 285             .wMaxPacketSize        = 64,
 286         },{
 287             .bEndpointAddress      = USB_DIR_OUT | EP_DATA_OUT,
 288             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
 289             .wMaxPacketSize        = 64,
 290         },{
 291             .bEndpointAddress      = USB_DIR_IN | EP_EVENT,
 292             .bmAttributes          = USB_ENDPOINT_XFER_INT,
 293             .wMaxPacketSize        = 64,
 294             .bInterval             = 0x0a,
 295         },
 296     }
 297 };
 298
 299 static const USBDescDevice desc_device_full = {
 300     .bcdUSB                        = 0x0200,
 301     .bMaxPacketSize0               = 8,
 302     .bNumConfigurations            = 1,
 303     .confs = (USBDescConfig[]) {
 304         {
 305             .bNumInterfaces        = 1,
 306             .bConfigurationValue   = 1,
 307             .iConfiguration        = STR_CONFIG_FULL,
 308             .bmAttributes          = USB_CFG_ATT_ONE | USB_CFG_ATT_WAKEUP,
 309             .bMaxPower             = 2,
 310             .nif = 1,
 311             .ifs = &desc_iface_full,
 312         },
 313     },
 314 };
 315
 316 static const USBDescIface desc_iface_high = {
 317     .bInterfaceNumber              = 0,
 318     .bNumEndpoints                 = 3,
 319     .bInterfaceClass               = USB_CLASS_STILL_IMAGE,
 320     .bInterfaceSubClass            = 0x01,
 321     .bInterfaceProtocol            = 0x01,
 322     .iInterface                    = STR_MTP,
 323     .eps = (USBDescEndpoint[]) {
 324         {
 325             .bEndpointAddress      = USB_DIR_IN | EP_DATA_IN,
 326             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
 327             .wMaxPacketSize        = 512,
 328         },{
 329             .bEndpointAddress      = USB_DIR_OUT | EP_DATA_OUT,
 330             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
 331             .wMaxPacketSize        = 512,
 332         },{
 333             .bEndpointAddress      = USB_DIR_IN | EP_EVENT,
 334             .bmAttributes          = USB_ENDPOINT_XFER_INT,
 335             .wMaxPacketSize        = 64,
 336             .bInterval             = 0x0a,
 337         },
 338     }
 339 };
 340
 341 static const USBDescDevice desc_device_high = {
 342     .bcdUSB                        = 0x0200,
 343     .bMaxPacketSize0               = 64,
 344     .bNumConfigurations            = 1,
 345     .confs = (USBDescConfig[]) {
 346         {
 347             .bNumInterfaces        = 1,
 348             .bConfigurationValue   = 1,
 349             .iConfiguration        = STR_CONFIG_HIGH,
 350             .bmAttributes          = USB_CFG_ATT_ONE | USB_CFG_ATT_WAKEUP,
 351             .bMaxPower             = 2,
 352             .nif = 1,
 353             .ifs = &desc_iface_high,
 354         },
 355     },
 356 };
 357
 358 static const USBDescMSOS desc_msos = {
 359     .CompatibleID = "MTP",
 360     .SelectiveSuspendEnabled = true,
 361 };
 362
 363 static const USBDesc desc = {
 364     .id = {
 365         .idVendor          = 0x46f4, /* CRC16() of "QEMU" */
 366         .idProduct         = 0x0004,
 367         .bcdDevice         = 0,
 368         .iManufacturer     = STR_MANUFACTURER,
 369         .iProduct          = STR_PRODUCT,
 370         .iSerialNumber     = STR_SERIALNUMBER,
 371     },
 372     .full  = &desc_device_full,
 373     .high  = &desc_device_high,
 374     .str   = desc_strings,
 375     .msos  = &desc_msos,
 376 };
 377
 378 /* ----------------------------------------------------------------------- */
 379
 380 static MTPObject *usb_mtp_object_alloc(MTPState *s, uint32_t handle,
 381                                        MTPObject *parent, const char *name)
 382 {
 383     MTPObject *o = g_new0(MTPObject, 1);
 384
 385     if (name[0] == '.') {
 386         goto ignore;
 387     }
 388
 389     o->watchid = -1;
 390     o->handle = handle;
 391     o->parent = parent;
 392     o->name = g_strdup(name);
 393     if (parent == NULL) {
 394         o->path = g_strdup(name);
 395     } else {
 396         o->path = g_strdup_printf("%s/%s", parent->path, name);
 397     }
 398
 399     if (lstat(o->path, &o->stat) != 0) {
 400         goto ignore;
 401     }
 402     if (S_ISREG(o->stat.st_mode)) {
 403         o->format = FMT_UNDEFINED_OBJECT;
 404     } else if (S_ISDIR(o->stat.st_mode)) {
 405         o->format = FMT_ASSOCIATION;
 406     } else {
 407         goto ignore;
 408     }
 409
 410     if (access(o->path, R_OK) != 0) {
 411         goto ignore;
 412     }
 413
 414     trace_usb_mtp_object_alloc(s->dev.addr, o->handle, o->path);
 415
 416     QTAILQ_INSERT_TAIL(&s->objects, o, next);
 417     return o;
 418
 419 ignore:
 420     g_free(o->name);
 421     g_free(o->path);
 422     g_free(o);
 423     return NULL;
 424 }
 425
 426 static void usb_mtp_object_free(MTPState *s, MTPObject *o)
 427 {
 428     MTPObject *iter;
 429
 430     if (!o) {
 431         return;
 432     }
 433
 434     trace_usb_mtp_object_free(s->dev.addr, o->handle, o->path);
 435
 436     if (o->watchid != -1 && s->file_monitor) {
 437         qemu_file_monitor_remove_watch(s->file_monitor, o->path, o->watchid);
 438     }
 439
 440     QTAILQ_REMOVE(&s->objects, o, next);
 441     if (o->parent) {
 442         QLIST_REMOVE(o, list);
 443         o->parent->nchildren--;
 444     }
 445
 446     while (!QLIST_EMPTY(&o->children)) {
 447         iter = QLIST_FIRST(&o->children);
 448         usb_mtp_object_free(s, iter);
 449     }
 450     g_free(o->name);
 451     g_free(o->path);
 452     g_free(o);
 453 }
 454
 455 static MTPObject *usb_mtp_object_lookup(MTPState *s, uint32_t handle)
 456 {
 457     MTPObject *o;
 458
 459     QTAILQ_FOREACH(o, &s->objects, next) {
 460         if (o->handle == handle) {
 461             return o;
 462         }
 463     }
 464     return NULL;
 465 }
 466
 467 static MTPObject *usb_mtp_add_child(MTPState *s, MTPObject *o,
 468                                     const char *name)
 469 {
 470     MTPObject *child =
 471         usb_mtp_object_alloc(s, s->next_handle++, o, name);
 472
 473     if (child) {
 474         trace_usb_mtp_add_child(s->dev.addr, child->handle, child->path);
 475         QLIST_INSERT_HEAD(&o->children, child, list);
 476         o->nchildren++;
 477
 478         if (child->format == FMT_ASSOCIATION) {
 479             QLIST_INIT(&child->children);
 480         }
 481     }
 482
 483     return child;
 484 }
 485
 486 static MTPObject *usb_mtp_object_lookup_name(MTPObject *parent,
 487                                              const char *name, int len)
 488 {
 489     MTPObject *iter;
 490
 491     if (len == -1) {
 492         len = strlen(name);
 493     }
 494
 495     QLIST_FOREACH(iter, &parent->children, list) {
 496         if (strncmp(iter->name, name, len) == 0) {
 497             return iter;
 498         }
 499     }
 500
 501     return NULL;
 502 }
 503
 504 static MTPObject *usb_mtp_object_lookup_id(MTPState *s, int64_t id)
 505 {
 506     MTPObject *iter;
 507
 508     QTAILQ_FOREACH(iter, &s->objects, next) {
 509         if (iter->watchid == id) {
 510             return iter;
 511         }
 512     }
 513
 514     return NULL;
 515 }
 516
 517 static void file_monitor_event(int64_t id,
 518                                QFileMonitorEvent ev,
 519                                const char *name,
 520                                void *opaque)
 521 {
 522     MTPState *s = opaque;
 523     MTPObject *parent = usb_mtp_object_lookup_id(s, id);
 524     MTPMonEntry *entry = NULL;
 525     MTPObject *o;
 526
 527     if (!parent) {
 528         return;
 529     }
 530
 531     switch (ev) {
 532     case QFILE_MONITOR_EVENT_CREATED:
 533         if (usb_mtp_object_lookup_name(parent, name, -1)) {
 534             /* Duplicate create event */
 535             return;
 536         }
 537         entry = g_new0(MTPMonEntry, 1);
 538         entry->handle = s->next_handle;
 539         entry->event = EVT_OBJ_ADDED;
 540         o = usb_mtp_add_child(s, parent, name);
 541         if (!o) {
 542             g_free(entry);
 543             return;
 544         }
 545         trace_usb_mtp_file_monitor_event(s->dev.addr, name, "Obj Added");
 546         break;
 547
 548     case QFILE_MONITOR_EVENT_DELETED:
 549         /*
 550          * The kernel issues a IN_IGNORED event
 551          * when a dir containing a watchpoint is
 552          * deleted, so we don't have to delete the
 553          * watchpoint
 554          */
 555         o = usb_mtp_object_lookup_name(parent, name, -1);
 556         if (!o) {
 557             return;
 558         }
 559         entry = g_new0(MTPMonEntry, 1);
 560         entry->handle = o->handle;
 561         entry->event = EVT_OBJ_REMOVED;
 562         trace_usb_mtp_file_monitor_event(s->dev.addr, o->path, "Obj Deleted");
 563         usb_mtp_object_free(s, o);
 564         break;
 565
 566     case QFILE_MONITOR_EVENT_MODIFIED:
 567         o = usb_mtp_object_lookup_name(parent, name, -1);
 568         if (!o) {
 569             return;
 570         }
 571         entry = g_new0(MTPMonEntry, 1);
 572         entry->handle = o->handle;
 573         entry->event = EVT_OBJ_INFO_CHANGED;
 574         trace_usb_mtp_file_monitor_event(s->dev.addr, o->path, "Obj Modified");
 575         break;
 576
 577     case QFILE_MONITOR_EVENT_IGNORED:
 578         trace_usb_mtp_file_monitor_event(s->dev.addr, parent->path,
 579                                     "Obj parent dir ignored");
 580         break;
 581
 582     case QFILE_MONITOR_EVENT_ATTRIBUTES:
 583         break;
 584
 585     default:
 586         g_assert_not_reached();
 587     }
 588
 589     if (entry) {
 590         QTAILQ_INSERT_HEAD(&s->events, entry, next);
 591     }
 592 }
 593
 594 static void usb_mtp_file_monitor_cleanup(MTPState *s)
 595 {
 596     MTPMonEntry *e, *p;
 597
 598     QTAILQ_FOREACH_SAFE(e, &s->events, next, p) {
 599         QTAILQ_REMOVE(&s->events, e, next);
 600         g_free(e);
 601     }
 602
 603     qemu_file_monitor_free(s->file_monitor);
 604     s->file_monitor = NULL;
 605 }
 606
 607
 608 static void usb_mtp_object_readdir(MTPState *s, MTPObject *o)
 609 {
 610     struct dirent *entry;
 611     DIR *dir;
 612     int fd;
 613     Error *err = NULL;
 614
 615     if (o->have_children) {
 616         return;
 617     }
 618     o->have_children = true;
 619
 620     fd = open(o->path, O_DIRECTORY | O_CLOEXEC | O_NOFOLLOW);
 621     if (fd < 0) {
 622         return;
 623     }
 624     dir = fdopendir(fd);
 625     if (!dir) {
 626         close(fd);
 627         return;
 628     }
 629
 630     if (s->file_monitor) {
 631         int64_t id = qemu_file_monitor_add_watch(s->file_monitor, o->path, NULL,
 632                                                  file_monitor_event, s, &err);
 633         if (id == -1) {
 634             error_report("usb-mtp: failed to add watch for %s: %s", o->path,
 635                          error_get_pretty(err));
 636             error_free(err);
 637         } else {
 638             trace_usb_mtp_file_monitor_event(s->dev.addr, o->path,
 639                                              "Watch Added");
 640             o->watchid = id;
 641         }
 642     }
 643
 644     while ((entry = readdir(dir)) != NULL) {
 645         usb_mtp_add_child(s, o, entry->d_name);
 646     }
 647     closedir(dir);
 648 }
 649
 650 /* ----------------------------------------------------------------------- */
 651
 652 static MTPData *usb_mtp_data_alloc(MTPControl *c)
 653 {
 654     MTPData *data = g_new0(MTPData, 1);
 655
 656     data->code  = c->code;
 657     data->trans = c->trans;
 658     data->fd    = -1;
 659     data->first = true;
 660     return data;
 661 }
 662
 663 static void usb_mtp_data_free(MTPData *data)
 664 {
 665     if (data == NULL) {
 666         return;
 667     }
 668     if (data->fd != -1) {
 669         close(data->fd);
 670     }
 671     g_free(data->data);
 672     g_free(data);
 673 }
 674
 675 static void usb_mtp_realloc(MTPData *data, uint32_t bytes)
 676 {
 677     if (data->length + bytes <= data->alloc) {
 678         return;
 679     }
 680     data->alloc = (data->length + bytes + 0xff) & ~0xff;
 681     data->data  = g_realloc(data->data, data->alloc);
 682 }
 683
 684 static void usb_mtp_add_u8(MTPData *data, uint8_t val)
 685 {
 686     usb_mtp_realloc(data, 1);
 687     data->data[data->length++] = val;
 688 }
 689
 690 static void usb_mtp_add_u16(MTPData *data, uint16_t val)
 691 {
 692     usb_mtp_realloc(data, 2);
 693     data->data[data->length++] = (val >> 0) & 0xff;
 694     data->data[data->length++] = (val >> 8) & 0xff;
 695 }
 696
 697 static void usb_mtp_add_u32(MTPData *data, uint32_t val)
 698 {
 699     usb_mtp_realloc(data, 4);
 700     data->data[data->length++] = (val >>  0) & 0xff;
 701     data->data[data->length++] = (val >>  8) & 0xff;
 702     data->data[data->length++] = (val >> 16) & 0xff;
 703     data->data[data->length++] = (val >> 24) & 0xff;
 704 }
 705
 706 static void usb_mtp_add_u64(MTPData *data, uint64_t val)
 707 {
 708     usb_mtp_realloc(data, 8);
 709     data->data[data->length++] = (val >>  0) & 0xff;
 710     data->data[data->length++] = (val >>  8) & 0xff;
 711     data->data[data->length++] = (val >> 16) & 0xff;
 712     data->data[data->length++] = (val >> 24) & 0xff;
 713     data->data[data->length++] = (val >> 32) & 0xff;
 714     data->data[data->length++] = (val >> 40) & 0xff;
 715     data->data[data->length++] = (val >> 48) & 0xff;
 716     data->data[data->length++] = (val >> 56) & 0xff;
 717 }
 718
 719 static void usb_mtp_add_u16_array(MTPData *data, uint32_t len,
 720                                   const uint16_t *vals)
 721 {
 722     int i;
 723
 724     usb_mtp_add_u32(data, len);
 725     for (i = 0; i < len; i++) {
 726         usb_mtp_add_u16(data, vals[i]);
 727     }
 728 }
 729
 730 static void usb_mtp_add_u32_array(MTPData *data, uint32_t len,
 731                                   const uint32_t *vals)
 732 {
 733     int i;
 734
 735     usb_mtp_add_u32(data, len);
 736     for (i = 0; i < len; i++) {
 737         usb_mtp_add_u32(data, vals[i]);
 738     }
 739 }
 740
 741 static void usb_mtp_add_wstr(MTPData *data, const wchar_t *str)
 742 {
 743     uint32_t len = wcslen(str);
 744     int i;
 745
 746     if (len > 0) {
 747         len++; /* include terminating L'\0' */
 748     }
 749
 750     usb_mtp_add_u8(data, len);
 751     for (i = 0; i < len; i++) {
 752         usb_mtp_add_u16(data, str[i]);
 753     }
 754 }
 755
 756 static void usb_mtp_add_str(MTPData *data, const char *str)
 757 {
 758     uint32_t len = strlen(str)+1;
 759     wchar_t *wstr = g_new(wchar_t, len);
 760     size_t ret;
 761
 762     ret = mbstowcs(wstr, str, len);
 763     if (ret == -1) {
 764         usb_mtp_add_wstr(data, L"Oops");
 765     } else {
 766         usb_mtp_add_wstr(data, wstr);
 767     }
 768
 769     g_free(wstr);
 770 }
 771
 772 static void usb_mtp_add_time(MTPData *data, time_t time)
 773 {
 774     char buf[16];
 775     struct tm tm;
 776
 777     gmtime_r(&time, &tm);
 778     strftime(buf, sizeof(buf), "%Y%m%dT%H%M%S", &tm);
 779     usb_mtp_add_str(data, buf);
 780 }
 781
 782 /* ----------------------------------------------------------------------- */
 783
 784 static void usb_mtp_queue_result(MTPState *s, uint16_t code, uint32_t trans,
 785                                  int argc, uint32_t arg0, uint32_t arg1,
 786                                  uint32_t arg2)
 787 {
 788     MTPControl *c = g_new0(MTPControl, 1);
 789
 790     c->code  = code;
 791     c->trans = trans;
 792     c->argc  = argc;
 793     if (argc > 0) {
 794         c->argv[0] = arg0;
 795     }
 796     if (argc > 1) {
 797         c->argv[1] = arg1;
 798     }
 799     if (argc > 2) {
 800         c->argv[2] = arg2;
 801     }
 802
 803     assert(s->result == NULL);
 804     s->result = c;
 805 }
 806
 807 /* ----------------------------------------------------------------------- */
 808
 809 static MTPData *usb_mtp_get_device_info(MTPState *s, MTPControl *c)
 810 {
 811     static const uint16_t ops[] = {
 812         CMD_GET_DEVICE_INFO,
 813         CMD_OPEN_SESSION,
 814         CMD_CLOSE_SESSION,
 815         CMD_GET_STORAGE_IDS,
 816         CMD_GET_STORAGE_INFO,
 817         CMD_GET_NUM_OBJECTS,
 818         CMD_GET_OBJECT_HANDLES,
 819         CMD_GET_OBJECT_INFO,
 820         CMD_DELETE_OBJECT,
 821         CMD_SEND_OBJECT_INFO,
 822         CMD_SEND_OBJECT,
 823         CMD_GET_OBJECT,
 824         CMD_GET_PARTIAL_OBJECT,
 825         CMD_GET_OBJECT_PROPS_SUPPORTED,
 826         CMD_GET_OBJECT_PROP_DESC,
 827         CMD_GET_OBJECT_PROP_VALUE,
 828     };
 829     static const uint16_t fmt[] = {
 830         FMT_UNDEFINED_OBJECT,
 831         FMT_ASSOCIATION,
 832     };
 833     MTPData *d = usb_mtp_data_alloc(c);
 834
 835     trace_usb_mtp_op_get_device_info(s->dev.addr);
 836
 837     usb_mtp_add_u16(d, 100);
 838     usb_mtp_add_u32(d, 0x00000006);
 839     usb_mtp_add_u16(d, 0x0064);
 840     usb_mtp_add_wstr(d, L"");
 841     usb_mtp_add_u16(d, 0x0000);
 842
 843     usb_mtp_add_u16_array(d, ARRAY_SIZE(ops), ops);
 844     usb_mtp_add_u16_array(d, 0, NULL);
 845     usb_mtp_add_u16_array(d, 0, NULL);
 846     usb_mtp_add_u16_array(d, 0, NULL);
 847     usb_mtp_add_u16_array(d, ARRAY_SIZE(fmt), fmt);
 848
 849     usb_mtp_add_wstr(d, L"" MTP_MANUFACTURER);
 850     usb_mtp_add_wstr(d, L"" MTP_PRODUCT);
 851     usb_mtp_add_wstr(d, L"0.1");
 852     usb_mtp_add_wstr(d, L"0123456789abcdef0123456789abcdef");
 853
 854     return d;
 855 }
 856
 857 static MTPData *usb_mtp_get_storage_ids(MTPState *s, MTPControl *c)
 858 {
 859     static const uint32_t ids[] = {
 860         QEMU_STORAGE_ID,
 861     };
 862     MTPData *d = usb_mtp_data_alloc(c);
 863
 864     trace_usb_mtp_op_get_storage_ids(s->dev.addr);
 865
 866     usb_mtp_add_u32_array(d, ARRAY_SIZE(ids), ids);
 867
 868     return d;
 869 }
 870
 871 static MTPData *usb_mtp_get_storage_info(MTPState *s, MTPControl *c)
 872 {
 873     MTPData *d = usb_mtp_data_alloc(c);
 874     struct statvfs buf;
 875     int rc;
 876
 877     trace_usb_mtp_op_get_storage_info(s->dev.addr);
 878
 879     if (FLAG_SET(s, MTP_FLAG_WRITABLE)) {
 880         usb_mtp_add_u16(d, 0x0003);
 881         usb_mtp_add_u16(d, 0x0002);
 882         usb_mtp_add_u16(d, 0x0000);
 883     } else {
 884         usb_mtp_add_u16(d, 0x0001);
 885         usb_mtp_add_u16(d, 0x0002);
 886         usb_mtp_add_u16(d, 0x0001);
 887     }
 888
 889     rc = statvfs(s->root, &buf);
 890     if (rc == 0) {
 891         usb_mtp_add_u64(d, (uint64_t)buf.f_frsize * buf.f_blocks);
 892         usb_mtp_add_u64(d, (uint64_t)buf.f_bavail * buf.f_blocks);
 893         usb_mtp_add_u32(d, buf.f_ffree);
 894     } else {
 895         usb_mtp_add_u64(d, 0xffffffff);
 896         usb_mtp_add_u64(d, 0xffffffff);
 897         usb_mtp_add_u32(d, 0xffffffff);
 898     }
 899
 900     usb_mtp_add_str(d, s->desc);
 901     usb_mtp_add_wstr(d, L"123456789abcdef");
 902     return d;
 903 }
 904
 905 static MTPData *usb_mtp_get_object_handles(MTPState *s, MTPControl *c,
 906                                            MTPObject *o)
 907 {
 908     MTPData *d = usb_mtp_data_alloc(c);
 909     uint32_t i = 0, handles[o->nchildren];
 910     MTPObject *iter;
 911
 912     trace_usb_mtp_op_get_object_handles(s->dev.addr, o->handle, o->path);
 913
 914     QLIST_FOREACH(iter, &o->children, list) {
 915         handles[i++] = iter->handle;
 916     }
 917     assert(i == o->nchildren);
 918     usb_mtp_add_u32_array(d, o->nchildren, handles);
 919
 920     return d;
 921 }
 922
 923 static MTPData *usb_mtp_get_object_info(MTPState *s, MTPControl *c,
 924                                         MTPObject *o)
 925 {
 926     MTPData *d = usb_mtp_data_alloc(c);
 927
 928     trace_usb_mtp_op_get_object_info(s->dev.addr, o->handle, o->path);
 929
 930     usb_mtp_add_u32(d, QEMU_STORAGE_ID);
 931     usb_mtp_add_u16(d, o->format);
 932     usb_mtp_add_u16(d, 0);
 933
 934     if (o->stat.st_size > 0xFFFFFFFF) {
 935         usb_mtp_add_u32(d, 0xFFFFFFFF);
 936     } else {
 937         usb_mtp_add_u32(d, o->stat.st_size);
 938     }
 939
 940     usb_mtp_add_u16(d, 0);
 941     usb_mtp_add_u32(d, 0);
 942     usb_mtp_add_u32(d, 0);
 943     usb_mtp_add_u32(d, 0);
 944     usb_mtp_add_u32(d, 0);
 945     usb_mtp_add_u32(d, 0);
 946     usb_mtp_add_u32(d, 0);
 947
 948     if (o->parent) {
 949         usb_mtp_add_u32(d, o->parent->handle);
 950     } else {
 951         usb_mtp_add_u32(d, 0);
 952     }
 953     if (o->format == FMT_ASSOCIATION) {
 954         usb_mtp_add_u16(d, 0x0001);
 955         usb_mtp_add_u32(d, 0x00000001);
 956         usb_mtp_add_u32(d, 0);
 957     } else {
 958         usb_mtp_add_u16(d, 0);
 959         usb_mtp_add_u32(d, 0);
 960         usb_mtp_add_u32(d, 0);
 961     }
 962
 963     usb_mtp_add_str(d, o->name);
 964     usb_mtp_add_time(d, o->stat.st_ctime);
 965     usb_mtp_add_time(d, o->stat.st_mtime);
 966     usb_mtp_add_wstr(d, L"");
 967
 968     return d;
 969 }
 970
 971 static MTPData *usb_mtp_get_object(MTPState *s, MTPControl *c,
 972                                    MTPObject *o)
 973 {
 974     MTPData *d = usb_mtp_data_alloc(c);
 975
 976     trace_usb_mtp_op_get_object(s->dev.addr, o->handle, o->path);
 977
 978     d->fd = open(o->path, O_RDONLY | O_CLOEXEC | O_NOFOLLOW);
 979     if (d->fd == -1) {
 980         usb_mtp_data_free(d);
 981         return NULL;
 982     }
 983     d->length = o->stat.st_size;
 984     d->alloc  = 512;
 985     d->data   = g_malloc(d->alloc);
 986     return d;
 987 }
 988
 989 static MTPData *usb_mtp_get_partial_object(MTPState *s, MTPControl *c,
 990                                            MTPObject *o)
 991 {
 992     MTPData *d;
 993     off_t offset;
 994
 995     if (c->argc <= 2) {
 996         return NULL;
 997     }
 998     trace_usb_mtp_op_get_partial_object(s->dev.addr, o->handle, o->path,
 999                                         c->argv[1], c->argv[2]);
1000
1001     d = usb_mtp_data_alloc(c);
1002     d->fd = open(o->path, O_RDONLY | O_CLOEXEC | O_NOFOLLOW);
1003     if (d->fd == -1) {
1004         usb_mtp_data_free(d);
1005         return NULL;
1006     }
1007
1008     offset = c->argv[1];
1009     if (offset > o->stat.st_size) {
1010         offset = o->stat.st_size;
1011     }
1012     if (lseek(d->fd, offset, SEEK_SET) < 0) {
1013         usb_mtp_data_free(d);
1014         return NULL;
1015     }
1016
1017     d->length = c->argv[2];
1018     if (d->length > o->stat.st_size - offset) {
1019         d->length = o->stat.st_size - offset;
1020     }
1021
1022     return d;
1023 }
1024
1025 static MTPData *usb_mtp_get_object_props_supported(MTPState *s, MTPControl *c)
1026 {
1027     static const uint16_t props[] = {
1028         PROP_STORAGE_ID,
1029         PROP_OBJECT_FORMAT,
1030         PROP_OBJECT_COMPRESSED_SIZE,
1031         PROP_PARENT_OBJECT,
1032         PROP_PERSISTENT_UNIQUE_OBJECT_IDENTIFIER,
1033         PROP_NAME,
1034     };
1035     MTPData *d = usb_mtp_data_alloc(c);
1036     usb_mtp_add_u16_array(d, ARRAY_SIZE(props), props);
1037
1038     return d;
1039 }
1040
1041 static MTPData *usb_mtp_get_object_prop_desc(MTPState *s, MTPControl *c)
1042 {
1043     MTPData *d = usb_mtp_data_alloc(c);
1044     switch (c->argv[0]) {
1045     case PROP_STORAGE_ID:
1046         usb_mtp_add_u16(d, PROP_STORAGE_ID);
1047         usb_mtp_add_u16(d, DATA_TYPE_UINT32);
1048         usb_mtp_add_u8(d, 0x00);
1049         usb_mtp_add_u32(d, 0x00000000);
1050         usb_mtp_add_u32(d, 0x00000000);
1051         usb_mtp_add_u8(d, 0x00);
1052         break;
1053     case PROP_OBJECT_FORMAT:
1054         usb_mtp_add_u16(d, PROP_OBJECT_FORMAT);
1055         usb_mtp_add_u16(d, DATA_TYPE_UINT16);
1056         usb_mtp_add_u8(d, 0x00);
1057         usb_mtp_add_u16(d, 0x0000);
1058         usb_mtp_add_u32(d, 0x00000000);
1059         usb_mtp_add_u8(d, 0x00);
1060         break;
1061     case PROP_OBJECT_COMPRESSED_SIZE:
1062         usb_mtp_add_u16(d, PROP_OBJECT_COMPRESSED_SIZE);
1063         usb_mtp_add_u16(d, DATA_TYPE_UINT64);
1064         usb_mtp_add_u8(d, 0x00);
1065         usb_mtp_add_u64(d, 0x0000000000000000);
1066         usb_mtp_add_u32(d, 0x00000000);
1067         usb_mtp_add_u8(d, 0x00);
1068         break;
1069     case PROP_PARENT_OBJECT:
1070         usb_mtp_add_u16(d, PROP_PARENT_OBJECT);
1071         usb_mtp_add_u16(d, DATA_TYPE_UINT32);
1072         usb_mtp_add_u8(d, 0x00);
1073         usb_mtp_add_u32(d, 0x00000000);
1074         usb_mtp_add_u32(d, 0x00000000);
1075         usb_mtp_add_u8(d, 0x00);
1076         break;
1077     case PROP_PERSISTENT_UNIQUE_OBJECT_IDENTIFIER:
1078         usb_mtp_add_u16(d, PROP_PERSISTENT_UNIQUE_OBJECT_IDENTIFIER);
1079         usb_mtp_add_u16(d, DATA_TYPE_UINT128);
1080         usb_mtp_add_u8(d, 0x00);
1081         usb_mtp_add_u64(d, 0x0000000000000000);
1082         usb_mtp_add_u64(d, 0x0000000000000000);
1083         usb_mtp_add_u32(d, 0x00000000);
1084         usb_mtp_add_u8(d, 0x00);
1085         break;
1086     case PROP_NAME:
1087         usb_mtp_add_u16(d, PROP_NAME);
1088         usb_mtp_add_u16(d, DATA_TYPE_STRING);
1089         usb_mtp_add_u8(d, 0x00);
1090         usb_mtp_add_u8(d, 0x00);
1091         usb_mtp_add_u32(d, 0x00000000);
1092         usb_mtp_add_u8(d, 0x00);
1093         break;
1094     default:
1095         usb_mtp_data_free(d);
1096         return NULL;
1097     }
1098
1099     return d;
1100 }
1101
1102 static MTPData *usb_mtp_get_object_prop_value(MTPState *s, MTPControl *c,
1103                                               MTPObject *o)
1104 {
1105     MTPData *d = usb_mtp_data_alloc(c);
1106     switch (c->argv[1]) {
1107     case PROP_STORAGE_ID:
1108         usb_mtp_add_u32(d, QEMU_STORAGE_ID);
1109         break;
1110     case PROP_OBJECT_FORMAT:
1111         usb_mtp_add_u16(d, o->format);
1112         break;
1113     case PROP_OBJECT_COMPRESSED_SIZE:
1114         usb_mtp_add_u64(d, o->stat.st_size);
1115         break;
1116     case PROP_PARENT_OBJECT:
1117         if (o->parent == NULL) {
1118             usb_mtp_add_u32(d, 0x00000000);
1119         } else {
1120             usb_mtp_add_u32(d, o->parent->handle);
1121         }
1122         break;
1123     case PROP_PERSISTENT_UNIQUE_OBJECT_IDENTIFIER:
1124         /* Should be persistent between sessions,
1125          * but using our objedt ID is "good enough"
1126          * for now */
1127         usb_mtp_add_u64(d, 0x0000000000000000);
1128         usb_mtp_add_u64(d, o->handle);
1129         break;
1130     case PROP_NAME:
1131         usb_mtp_add_str(d, o->name);
1132         break;
1133     default:
1134         usb_mtp_data_free(d);
1135         return NULL;
1136     }
1137
1138     return d;
1139 }
1140
1141 /*
1142  * Return values when object @o is deleted.
1143  * If at least one of the deletions succeeded,
1144  * DELETE_SUCCESS is set and if at least one
1145  * of the deletions failed, DELETE_FAILURE is
1146  * set. Both bits being set (DELETE_PARTIAL)
1147  * signifies a  RES_PARTIAL_DELETE being sent
1148  * back to the initiator.
1149  */
1150 enum {
1151     DELETE_SUCCESS = (1 << 0),
1152     DELETE_FAILURE = (1 << 1),
1153     DELETE_PARTIAL = (DELETE_FAILURE | DELETE_SUCCESS),
1154 };
1155
1156 static int usb_mtp_deletefn(MTPState *s, MTPObject *o, uint32_t trans)
1157 {
1158     MTPObject *iter, *iter2;
1159     int ret = 0;
1160
1161     /*
1162      * TODO: Add support for Protection Status
1163      */
1164
1165     QLIST_FOREACH(iter, &o->children, list) {
1166         if (iter->format == FMT_ASSOCIATION) {
1167             QLIST_FOREACH(iter2, &iter->children, list) {
1168                 ret |= usb_mtp_deletefn(s, iter2, trans);
1169             }
1170         }
1171     }
1172
1173     if (o->format == FMT_UNDEFINED_OBJECT) {
1174         if (remove(o->path)) {
1175             ret |= DELETE_FAILURE;
1176         } else {
1177             usb_mtp_object_free(s, o);
1178             ret |= DELETE_SUCCESS;
1179         }
1180     } else if (o->format == FMT_ASSOCIATION) {
1181         if (rmdir(o->path)) {
1182             ret |= DELETE_FAILURE;
1183         } else {
1184             usb_mtp_object_free(s, o);
1185             ret |= DELETE_SUCCESS;
1186         }
1187     }
1188
1189     return ret;
1190 }
1191
1192 static void usb_mtp_object_delete(MTPState *s, uint32_t handle,
1193                                   uint32_t format_code, uint32_t trans)
1194 {
1195     MTPObject *o;
1196     int ret;
1197
1198     /* Return error if store is read-only */
1199     if (!FLAG_SET(s, MTP_FLAG_WRITABLE)) {
1200         usb_mtp_queue_result(s, RES_STORE_READ_ONLY,
1201                              trans, 0, 0, 0, 0);
1202         return;
1203     }
1204
1205     if (format_code != 0) {
1206         usb_mtp_queue_result(s, RES_SPEC_BY_FORMAT_UNSUPPORTED,
1207                              trans, 0, 0, 0, 0);
1208         return;
1209     }
1210
1211     if (handle == 0xFFFFFFF) {
1212         o = QTAILQ_FIRST(&s->objects);
1213     } else {
1214         o = usb_mtp_object_lookup(s, handle);
1215     }
1216     if (o == NULL) {
1217         usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1218                              trans, 0, 0, 0, 0);
1219         return;
1220     }
1221
1222     ret = usb_mtp_deletefn(s, o, trans);
1223     switch (ret) {
1224     case DELETE_SUCCESS:
1225         usb_mtp_queue_result(s, RES_OK, trans,
1226                              0, 0, 0, 0);
1227         break;
1228     case DELETE_FAILURE:
1229         usb_mtp_queue_result(s, RES_PARTIAL_DELETE,
1230                              trans, 0, 0, 0, 0);
1231         break;
1232     case DELETE_PARTIAL:
1233         usb_mtp_queue_result(s, RES_PARTIAL_DELETE,
1234                              trans, 0, 0, 0, 0);
1235         break;
1236     default:
1237         g_assert_not_reached();
1238     }
1239
1240     return;
1241 }
1242
1243 static void usb_mtp_command(MTPState *s, MTPControl *c)
1244 {
1245     MTPData *data_in = NULL;
1246     MTPObject *o = NULL;
1247     uint32_t nres = 0, res0 = 0;
1248     Error *err = NULL;
1249
1250     /* sanity checks */
1251     if (c->code >= CMD_CLOSE_SESSION && s->session == 0) {
1252         usb_mtp_queue_result(s, RES_SESSION_NOT_OPEN,
1253                              c->trans, 0, 0, 0, 0);
1254         return;
1255     }
1256
1257     /* process commands */
1258     switch (c->code) {
1259     case CMD_GET_DEVICE_INFO:
1260         data_in = usb_mtp_get_device_info(s, c);
1261         break;
1262     case CMD_OPEN_SESSION:
1263         if (s->session) {
1264             usb_mtp_queue_result(s, RES_SESSION_ALREADY_OPEN,
1265                                  c->trans, 1, s->session, 0, 0);
1266             return;
1267         }
1268         if (c->argv[0] == 0) {
1269             usb_mtp_queue_result(s, RES_INVALID_PARAMETER,
1270                                  c->trans, 0, 0, 0, 0);
1271             return;
1272         }
1273         trace_usb_mtp_op_open_session(s->dev.addr);
1274         s->session = c->argv[0];
1275         usb_mtp_object_alloc(s, s->next_handle++, NULL, s->root);
1276
1277         s->file_monitor = qemu_file_monitor_new(&err);
1278         if (err) {
1279             error_report("usb-mtp: file monitoring init failed: %s",
1280                          error_get_pretty(err));
1281             error_free(err);
1282         } else {
1283             QTAILQ_INIT(&s->events);
1284         }
1285         break;
1286     case CMD_CLOSE_SESSION:
1287         trace_usb_mtp_op_close_session(s->dev.addr);
1288         s->session = 0;
1289         s->next_handle = 0;
1290         usb_mtp_file_monitor_cleanup(s);
1291         usb_mtp_object_free(s, QTAILQ_FIRST(&s->objects));
1292         assert(QTAILQ_EMPTY(&s->objects));
1293         break;
1294     case CMD_GET_STORAGE_IDS:
1295         data_in = usb_mtp_get_storage_ids(s, c);
1296         break;
1297     case CMD_GET_STORAGE_INFO:
1298         if (c->argv[0] != QEMU_STORAGE_ID &&
1299             c->argv[0] != 0xffffffff) {
1300             usb_mtp_queue_result(s, RES_INVALID_STORAGE_ID,
1301                                  c->trans, 0, 0, 0, 0);
1302             return;
1303         }
1304         data_in = usb_mtp_get_storage_info(s, c);
1305         break;
1306     case CMD_GET_NUM_OBJECTS:
1307     case CMD_GET_OBJECT_HANDLES:
1308         if (c->argv[0] != QEMU_STORAGE_ID &&
1309             c->argv[0] != 0xffffffff) {
1310             usb_mtp_queue_result(s, RES_INVALID_STORAGE_ID,
1311                                  c->trans, 0, 0, 0, 0);
1312             return;
1313         }
1314         if (c->argv[1] != 0x00000000) {
1315             usb_mtp_queue_result(s, RES_SPEC_BY_FORMAT_UNSUPPORTED,
1316                                  c->trans, 0, 0, 0, 0);
1317             return;
1318         }
1319         if (c->argv[2] == 0x00000000 ||
1320             c->argv[2] == 0xffffffff) {
1321             o = QTAILQ_FIRST(&s->objects);
1322         } else {
1323             o = usb_mtp_object_lookup(s, c->argv[2]);
1324         }
1325         if (o == NULL) {
1326             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1327                                  c->trans, 0, 0, 0, 0);
1328             return;
1329         }
1330         if (o->format != FMT_ASSOCIATION) {
1331             usb_mtp_queue_result(s, RES_INVALID_PARENT_OBJECT,
1332                                  c->trans, 0, 0, 0, 0);
1333             return;
1334         }
1335         usb_mtp_object_readdir(s, o);
1336         if (c->code == CMD_GET_NUM_OBJECTS) {
1337             trace_usb_mtp_op_get_num_objects(s->dev.addr, o->handle, o->path);
1338             nres = 1;
1339             res0 = o->nchildren;
1340         } else {
1341             data_in = usb_mtp_get_object_handles(s, c, o);
1342         }
1343         break;
1344     case CMD_GET_OBJECT_INFO:
1345         o = usb_mtp_object_lookup(s, c->argv[0]);
1346         if (o == NULL) {
1347             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1348                                  c->trans, 0, 0, 0, 0);
1349             return;
1350         }
1351         data_in = usb_mtp_get_object_info(s, c, o);
1352         break;
1353     case CMD_GET_OBJECT:
1354         o = usb_mtp_object_lookup(s, c->argv[0]);
1355         if (o == NULL) {
1356             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1357                                  c->trans, 0, 0, 0, 0);
1358             return;
1359         }
1360         if (o->format == FMT_ASSOCIATION) {
1361             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1362                                  c->trans, 0, 0, 0, 0);
1363             return;
1364         }
1365         data_in = usb_mtp_get_object(s, c, o);
1366         if (data_in == NULL) {
1367             usb_mtp_queue_result(s, RES_GENERAL_ERROR,
1368                                  c->trans, 0, 0, 0, 0);
1369             return;
1370         }
1371         break;
1372     case CMD_DELETE_OBJECT:
1373         usb_mtp_object_delete(s, c->argv[0], c->argv[1], c->trans);
1374         return;
1375     case CMD_GET_PARTIAL_OBJECT:
1376         o = usb_mtp_object_lookup(s, c->argv[0]);
1377         if (o == NULL) {
1378             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1379                                  c->trans, 0, 0, 0, 0);
1380             return;
1381         }
1382         if (o->format == FMT_ASSOCIATION) {
1383             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1384                                  c->trans, 0, 0, 0, 0);
1385             return;
1386         }
1387         data_in = usb_mtp_get_partial_object(s, c, o);
1388         if (data_in == NULL) {
1389             usb_mtp_queue_result(s, RES_GENERAL_ERROR,
1390                                  c->trans, 0, 0, 0, 0);
1391             return;
1392         }
1393         nres = 1;
1394         res0 = data_in->length;
1395         break;
1396     case CMD_SEND_OBJECT_INFO:
1397         /* Return error if store is read-only */
1398         if (!FLAG_SET(s, MTP_FLAG_WRITABLE)) {
1399             usb_mtp_queue_result(s, RES_STORE_READ_ONLY,
1400                                  c->trans, 0, 0, 0, 0);
1401         } else if (c->argv[0] && (c->argv[0] != QEMU_STORAGE_ID)) {
1402             /* First parameter points to storage id or is 0 */
1403             usb_mtp_queue_result(s, RES_STORE_NOT_AVAILABLE, c->trans,
1404                                  0, 0, 0, 0);
1405         } else if (c->argv[1] && !c->argv[0]) {
1406             /* If second parameter is specified, first must also be specified */
1407             usb_mtp_queue_result(s, RES_DESTINATION_UNSUPPORTED, c->trans,
1408                                  0, 0, 0, 0);
1409         } else {
1410             uint32_t handle = c->argv[1];
1411             if (handle == 0xFFFFFFFF || handle == 0) {
1412                 /* root object */
1413                 o = QTAILQ_FIRST(&s->objects);
1414             } else {
1415                 o = usb_mtp_object_lookup(s, handle);
1416             }
1417             if (o == NULL) {
1418                 usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE, c->trans,
1419                                      0, 0, 0, 0);
1420             } else if (o->format != FMT_ASSOCIATION) {
1421                 usb_mtp_queue_result(s, RES_INVALID_PARENT_OBJECT, c->trans,
1422                                      0, 0, 0, 0);
1423             }
1424         }
1425         if (o) {
1426             s->dataset.parent_handle = o->handle;
1427         }
1428         s->data_out = usb_mtp_data_alloc(c);
1429         return;
1430     case CMD_SEND_OBJECT:
1431         if (!FLAG_SET(s, MTP_FLAG_WRITABLE)) {
1432             usb_mtp_queue_result(s, RES_STORE_READ_ONLY,
1433                                  c->trans, 0, 0, 0, 0);
1434             return;
1435         }
1436         if (!s->write_pending) {
1437             usb_mtp_queue_result(s, RES_INVALID_OBJECTINFO,
1438                                  c->trans, 0, 0, 0, 0);
1439             return;
1440         }
1441         s->data_out = usb_mtp_data_alloc(c);
1442         return;
1443     case CMD_GET_OBJECT_PROPS_SUPPORTED:
1444         if (c->argv[0] != FMT_UNDEFINED_OBJECT &&
1445             c->argv[0] != FMT_ASSOCIATION) {
1446             usb_mtp_queue_result(s, RES_INVALID_OBJECT_FORMAT_CODE,
1447                                  c->trans, 0, 0, 0, 0);
1448             return;
1449         }
1450         data_in = usb_mtp_get_object_props_supported(s, c);
1451         break;
1452     case CMD_GET_OBJECT_PROP_DESC:
1453         if (c->argv[1] != FMT_UNDEFINED_OBJECT &&
1454             c->argv[1] != FMT_ASSOCIATION) {
1455             usb_mtp_queue_result(s, RES_INVALID_OBJECT_FORMAT_CODE,
1456                                  c->trans, 0, 0, 0, 0);
1457             return;
1458         }
1459         data_in = usb_mtp_get_object_prop_desc(s, c);
1460         if (data_in == NULL) {
1461             usb_mtp_queue_result(s, RES_INVALID_OBJECT_PROP_CODE,
1462                                  c->trans, 0, 0, 0, 0);
1463             return;
1464         }
1465         break;
1466     case CMD_GET_OBJECT_PROP_VALUE:
1467         o = usb_mtp_object_lookup(s, c->argv[0]);
1468         if (o == NULL) {
1469             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1470                                  c->trans, 0, 0, 0, 0);
1471             return;
1472         }
1473         data_in = usb_mtp_get_object_prop_value(s, c, o);
1474         if (data_in == NULL) {
1475             usb_mtp_queue_result(s, RES_INVALID_OBJECT_PROP_CODE,
1476                                  c->trans, 0, 0, 0, 0);
1477             return;
1478         }
1479         break;
1480     default:
1481         trace_usb_mtp_op_unknown(s->dev.addr, c->code);
1482         usb_mtp_queue_result(s, RES_OPERATION_NOT_SUPPORTED,
1483                              c->trans, 0, 0, 0, 0);
1484         return;
1485     }
1486
1487     /* return results on success */
1488     if (data_in) {
1489         assert(s->data_in == NULL);
1490         s->data_in = data_in;
1491     }
1492     usb_mtp_queue_result(s, RES_OK, c->trans, nres, res0, 0, 0);
1493 }
1494
1495 /* ----------------------------------------------------------------------- */
1496
1497 static void usb_mtp_handle_reset(USBDevice *dev)
1498 {
1499     MTPState *s = USB_MTP(dev);
1500
1501     trace_usb_mtp_reset(s->dev.addr);
1502
1503     usb_mtp_file_monitor_cleanup(s);
1504     usb_mtp_object_free(s, QTAILQ_FIRST(&s->objects));
1505     s->session = 0;
1506     usb_mtp_data_free(s->data_in);
1507     s->data_in = NULL;
1508     usb_mtp_data_free(s->data_out);
1509     s->data_out = NULL;
1510     g_free(s->result);
1511     s->result = NULL;
1512 }
1513
1514 static void usb_mtp_handle_control(USBDevice *dev, USBPacket *p,
1515                                    int request, int value, int index,
1516                                    int length, uint8_t *data)
1517 {
1518     int ret;
1519     MTPState *s = USB_MTP(dev);
1520     uint16_t *event = (uint16_t *)data;
1521
1522     switch (request) {
1523     case ClassInterfaceOutRequest | 0x64:
1524         if (*event == EVT_CANCEL_TRANSACTION) {
1525             g_free(s->result);
1526             s->result = NULL;
1527             usb_mtp_data_free(s->data_in);
1528             s->data_in = NULL;
1529             if (s->write_pending) {
1530                 g_free(s->dataset.filename);
1531                 s->write_pending = false;
1532                 s->dataset.size = 0;
1533             }
1534             usb_mtp_data_free(s->data_out);
1535             s->data_out = NULL;
1536         } else {
1537             p->status = USB_RET_STALL;
1538         }
1539         break;
1540     default:
1541         ret = usb_desc_handle_control(dev, p, request,
1542                                       value, index, length, data);
1543         if (ret >= 0) {
1544             return;
1545         }
1546     }
1547
1548     trace_usb_mtp_stall(dev->addr, "unknown control request");
1549 }
1550
1551 static void usb_mtp_cancel_packet(USBDevice *dev, USBPacket *p)
1552 {
1553     /* we don't use async packets, so this should never be called */
1554     fprintf(stderr, "%s\n", __func__);
1555 }
1556
1557 static char *utf16_to_str(uint8_t len, uint8_t *str16)
1558 {
1559     wchar_t *wstr = g_new0(wchar_t, len + 1);
1560     int count, dlen;
1561     char *dest;
1562
1563     for (count = 0; count < len; count++) {
1564         /* FIXME: not working for surrogate pairs */
1565         wstr[count] = lduw_le_p(str16 + (count * 2));
1566     }
1567     wstr[count] = 0;
1568
1569     dlen = wcstombs(NULL, wstr, 0) + 1;
1570     dest = g_malloc(dlen);
1571     wcstombs(dest, wstr, dlen);
1572     g_free(wstr);
1573     return dest;
1574 }
1575
1576 /* Wrapper around write, returns 0 on failure */
1577 static uint64_t write_retry(int fd, void *buf, uint64_t size, off_t offset)
1578 {
1579         uint64_t ret = 0;
1580
1581         if (lseek(fd, offset, SEEK_SET) < 0) {
1582             goto done;
1583         }
1584
1585         ret = qemu_write_full(fd, buf, size);
1586
1587 done:
1588         return ret;
1589 }
1590
1591 static int usb_mtp_update_object(MTPObject *parent, char *name)
1592 {
1593     int ret = 0;
1594
1595     MTPObject *o =
1596         usb_mtp_object_lookup_name(parent, name, strlen(name));
1597
1598     if (o) {
1599         ret = lstat(o->path, &o->stat);
1600     }
1601
1602     return ret;
1603 }
1604
1605 static void usb_mtp_write_data(MTPState *s, uint32_t handle)
1606 {
1607     MTPData *d = s->data_out;
1608     MTPObject *parent =
1609         usb_mtp_object_lookup(s, s->dataset.parent_handle);
1610     char *path = NULL;
1611     uint64_t rc;
1612     mode_t mask = 0644;
1613     int ret = 0;
1614
1615     assert(d != NULL);
1616
1617     switch (d->write_status) {
1618     case WRITE_START:
1619         if (!parent || !s->write_pending) {
1620             usb_mtp_queue_result(s, RES_INVALID_OBJECTINFO, d->trans,
1621                 0, 0, 0, 0);
1622             return;
1623         }
1624
1625         if (s->dataset.filename) {
1626             path = g_strdup_printf("%s/%s", parent->path, s->dataset.filename);
1627             if (s->dataset.format == FMT_ASSOCIATION) {
1628                 ret = mkdir(path, mask);
1629                 if (!ret) {
1630                     usb_mtp_queue_result(s, RES_OK, d->trans, 3,
1631                                          QEMU_STORAGE_ID,
1632                                          s->dataset.parent_handle,
1633                                          handle);
1634                     goto close;
1635                 }
1636                 goto done;
1637             }
1638
1639             d->fd = open(path, O_CREAT | O_WRONLY |
1640                          O_CLOEXEC | O_NOFOLLOW, mask);
1641             if (d->fd == -1) {
1642                 ret = 1;
1643                 goto done;
1644             }
1645
1646             /* Return success if initiator sent 0 sized data */
1647             if (!s->dataset.size) {
1648                 goto done;
1649             }
1650             if (d->length != MTP_WRITE_BUF_SZ && !d->pending) {
1651                 d->write_status = WRITE_END;
1652             }
1653         }
1654         /* fall through */
1655     case WRITE_CONTINUE:
1656     case WRITE_END:
1657         rc = write_retry(d->fd, d->data, d->data_offset,
1658                          d->offset - d->data_offset);
1659         if (rc != d->data_offset) {
1660             ret = 1;
1661             goto done;
1662         }
1663         if (d->write_status != WRITE_END) {
1664             g_free(path);
1665             return;
1666         } else {
1667             /*
1668              * Return an incomplete transfer if file size doesn't match
1669              * for < 4G file or if lstat fails which will result in an incorrect
1670              * file size
1671              */
1672             if ((s->dataset.size != 0xFFFFFFFF &&
1673                  d->offset != s->dataset.size) ||
1674                 usb_mtp_update_object(parent, s->dataset.filename)) {
1675                 usb_mtp_queue_result(s, RES_INCOMPLETE_TRANSFER, d->trans,
1676                                      0, 0, 0, 0);
1677                 goto close;
1678             }
1679         }
1680     }
1681
1682 done:
1683     if (ret) {
1684         usb_mtp_queue_result(s, RES_STORE_FULL, d->trans,
1685                              0, 0, 0, 0);
1686     } else {
1687         usb_mtp_queue_result(s, RES_OK, d->trans,
1688                              0, 0, 0, 0);
1689     }
1690 close:
1691     /*
1692      * The write dataset is kept around and freed only
1693      * on success or if another write request comes in
1694      */
1695     if (d->fd != -1) {
1696         close(d->fd);
1697         d->fd = -1;
1698     }
1699     g_free(s->dataset.filename);
1700     s->dataset.size = 0;
1701     g_free(path);
1702     s->write_pending = false;
1703 }
1704
1705 static void usb_mtp_write_metadata(MTPState *s, uint64_t dlen)
1706 {
1707     MTPData *d = s->data_out;
1708     ObjectInfo *dataset = (ObjectInfo *)d->data;
1709     char *filename;
1710     MTPObject *o;
1711     MTPObject *p = usb_mtp_object_lookup(s, s->dataset.parent_handle);
1712     uint32_t next_handle = s->next_handle;
1713     size_t filename_chars = dlen - offsetof(ObjectInfo, filename);
1714
1715     /*
1716      * filename is utf-16. We're intentionally doing
1717      * integer division to truncate if malicious guest
1718      * sent an odd number of bytes.
1719      */
1720     filename_chars /= 2;
1721
1722     assert(!s->write_pending);
1723     assert(p != NULL);
1724
1725     filename = utf16_to_str(MIN(dataset->length, filename_chars),
1726                             dataset->filename);
1727
1728     if (strchr(filename, '/')) {
1729         usb_mtp_queue_result(s, RES_PARAMETER_NOT_SUPPORTED, d->trans,
1730                              0, 0, 0, 0);
1731         g_free(filename);
1732         return;
1733     }
1734
1735     o = usb_mtp_object_lookup_name(p, filename, -1);
1736     if (o != NULL) {
1737         next_handle = o->handle;
1738     }
1739
1740     s->dataset.filename = filename;
1741     s->dataset.format = dataset->format;
1742     s->dataset.size = dataset->size;
1743     s->write_pending = true;
1744
1745     if (s->dataset.format == FMT_ASSOCIATION) {
1746         usb_mtp_write_data(s, next_handle);
1747     } else {
1748         usb_mtp_queue_result(s, RES_OK, d->trans, 3, QEMU_STORAGE_ID,
1749                              s->dataset.parent_handle, next_handle);
1750     }
1751 }
1752
1753 static void usb_mtp_get_data(MTPState *s, mtp_container *container,
1754                              USBPacket *p)
1755 {
1756     MTPData *d = s->data_out;
1757     uint64_t dlen;
1758     uint32_t data_len = p->iov.size;
1759     uint64_t total_len;
1760
1761     if (!d) {
1762             usb_mtp_queue_result(s, RES_INVALID_OBJECTINFO, 0,
1763                                  0, 0, 0, 0);
1764             return;
1765     }
1766     if (d->first) {
1767         /* Total length of incoming data */
1768         total_len = cpu_to_le32(container->length) - sizeof(mtp_container);
1769         /* Length of data in this packet */
1770         data_len -= sizeof(mtp_container);
1771         if (total_len < MTP_WRITE_BUF_SZ) {
1772                 usb_mtp_realloc(d, total_len);
1773                 d->length += total_len;
1774         } else {
1775                 usb_mtp_realloc(d, MTP_WRITE_BUF_SZ - sizeof(mtp_container));
1776                 d->length += MTP_WRITE_BUF_SZ - sizeof(mtp_container);
1777         }
1778         d->offset = 0;
1779         d->first = false;
1780         d->pending = false;
1781         d->data_offset = 0;
1782         d->write_status = WRITE_START;
1783     }
1784
1785     if (d->pending) {
1786         memset(d->data, 0, d->length);
1787         if (d->length != MTP_WRITE_BUF_SZ) {
1788             usb_mtp_realloc(d, MTP_WRITE_BUF_SZ - d->length);
1789             d->length += (MTP_WRITE_BUF_SZ - d->length);
1790         }
1791         d->pending = false;
1792         d->write_status = WRITE_CONTINUE;
1793         d->data_offset = 0;
1794     }
1795
1796     if (d->length - d->data_offset > data_len) {
1797         dlen = data_len;
1798     } else {
1799         dlen = d->length - d->data_offset;
1800     }
1801
1802     switch (d->code) {
1803     case CMD_SEND_OBJECT_INFO:
1804         usb_packet_copy(p, d->data + d->data_offset, dlen);
1805         d->offset += dlen;
1806         d->data_offset += dlen;
1807         if (d->data_offset == d->length) {
1808             /* The operation might have already failed */
1809             if (!s->result) {
1810                 usb_mtp_write_metadata(s, dlen);
1811             }
1812             usb_mtp_data_free(s->data_out);
1813             s->data_out = NULL;
1814             return;
1815         }
1816         break;
1817     case CMD_SEND_OBJECT:
1818         usb_packet_copy(p, d->data + d->data_offset, dlen);
1819         d->offset += dlen;
1820         d->data_offset += dlen;
1821         if ((p->iov.size % 64) || !p->iov.size) {
1822             assert((s->dataset.size == 0xFFFFFFFF) ||
1823                    (s->dataset.size == d->offset));
1824
1825             if (d->length == MTP_WRITE_BUF_SZ) {
1826                 d->write_status = WRITE_END;
1827             } else {
1828                 d->write_status = WRITE_START;
1829             }
1830             usb_mtp_write_data(s, 0);
1831             usb_mtp_data_free(s->data_out);
1832             s->data_out = NULL;
1833             return;
1834         }
1835         if (d->data_offset == d->length) {
1836             d->pending = true;
1837             usb_mtp_write_data(s, 0);
1838         }
1839         break;
1840     default:
1841         p->status = USB_RET_STALL;
1842         return;
1843     }
1844 }
1845
1846 static void usb_mtp_handle_data(USBDevice *dev, USBPacket *p)
1847 {
1848     MTPState *s = USB_MTP(dev);
1849     MTPControl cmd;
1850     mtp_container container;
1851     uint32_t params[5];
1852     uint16_t container_type;
1853     int i, rc;
1854
1855     switch (p->ep->nr) {
1856     case EP_DATA_IN:
1857         if (s->data_out != NULL) {
1858             /* guest bug */
1859             trace_usb_mtp_stall(s->dev.addr, "awaiting data-out");
1860             p->status = USB_RET_STALL;
1861             return;
1862         }
1863         if (p->iov.size < sizeof(container)) {
1864             trace_usb_mtp_stall(s->dev.addr, "packet too small");
1865             p->status = USB_RET_STALL;
1866             return;
1867         }
1868         if (s->data_in !=  NULL) {
1869             MTPData *d = s->data_in;
1870             uint64_t dlen = d->length - d->offset;
1871             if (d->first) {
1872                 trace_usb_mtp_data_in(s->dev.addr, d->trans, d->length);
1873                 if (d->length + sizeof(container) > 0xFFFFFFFF) {
1874                     container.length = cpu_to_le32(0xFFFFFFFF);
1875                 } else {
1876                     container.length =
1877                         cpu_to_le32(d->length + sizeof(container));
1878                 }
1879                 container.type   = cpu_to_le16(TYPE_DATA);
1880                 container.code   = cpu_to_le16(d->code);
1881                 container.trans  = cpu_to_le32(d->trans);
1882                 usb_packet_copy(p, &container, sizeof(container));
1883                 d->first = false;
1884                 if (dlen > p->iov.size - sizeof(container)) {
1885                     dlen = p->iov.size - sizeof(container);
1886                 }
1887             } else {
1888                 if (dlen > p->iov.size) {
1889                     dlen = p->iov.size;
1890                 }
1891             }
1892             if (d->fd == -1) {
1893                 usb_packet_copy(p, d->data + d->offset, dlen);
1894             } else {
1895                 if (d->alloc < p->iov.size) {
1896                     d->alloc = p->iov.size;
1897                     d->data = g_realloc(d->data, d->alloc);
1898                 }
1899                 rc = read(d->fd, d->data, dlen);
1900                 if (rc != dlen) {
1901                     memset(d->data, 0, dlen);
1902                     s->result->code = RES_INCOMPLETE_TRANSFER;
1903                 }
1904                 usb_packet_copy(p, d->data, dlen);
1905             }
1906             d->offset += dlen;
1907             if (d->offset == d->length) {
1908                 usb_mtp_data_free(s->data_in);
1909                 s->data_in = NULL;
1910             }
1911         } else if (s->result != NULL) {
1912             MTPControl *r = s->result;
1913             int length = sizeof(container) + r->argc * sizeof(uint32_t);
1914             if (r->code == RES_OK) {
1915                 trace_usb_mtp_success(s->dev.addr, r->trans,
1916                                       (r->argc > 0) ? r->argv[0] : 0,
1917                                       (r->argc > 1) ? r->argv[1] : 0);
1918             } else {
1919                 trace_usb_mtp_error(s->dev.addr, r->code, r->trans,
1920                                     (r->argc > 0) ? r->argv[0] : 0,
1921                                     (r->argc > 1) ? r->argv[1] : 0);
1922             }
1923             container.length = cpu_to_le32(length);
1924             container.type   = cpu_to_le16(TYPE_RESPONSE);
1925             container.code   = cpu_to_le16(r->code);
1926             container.trans  = cpu_to_le32(r->trans);
1927             for (i = 0; i < r->argc; i++) {
1928                 params[i] = cpu_to_le32(r->argv[i]);
1929             }
1930             usb_packet_copy(p, &container, sizeof(container));
1931             usb_packet_copy(p, &params, length - sizeof(container));
1932             g_free(s->result);
1933             s->result = NULL;
1934         }
1935         break;
1936     case EP_DATA_OUT:
1937         if (p->iov.size < sizeof(container)) {
1938             trace_usb_mtp_stall(s->dev.addr, "packet too small");
1939             p->status = USB_RET_STALL;
1940             return;
1941         }
1942         if ((s->data_out != NULL) && !s->data_out->first) {
1943             container_type = TYPE_DATA;
1944         } else {
1945             usb_packet_copy(p, &container, sizeof(container));
1946             container_type = le16_to_cpu(container.type);
1947         }
1948         switch (container_type) {
1949         case TYPE_COMMAND:
1950             if (s->data_in || s->data_out || s->result) {
1951                 trace_usb_mtp_stall(s->dev.addr, "transaction inflight");
1952                 p->status = USB_RET_STALL;
1953                 return;
1954             }
1955             cmd.code = le16_to_cpu(container.code);
1956             cmd.argc = (le32_to_cpu(container.length) - sizeof(container))
1957                 / sizeof(uint32_t);
1958             cmd.trans = le32_to_cpu(container.trans);
1959             if (cmd.argc > ARRAY_SIZE(cmd.argv)) {
1960                 cmd.argc = ARRAY_SIZE(cmd.argv);
1961             }
1962             if (p->iov.size < sizeof(container) + cmd.argc * sizeof(uint32_t)) {
1963                 trace_usb_mtp_stall(s->dev.addr, "packet too small");
1964                 p->status = USB_RET_STALL;
1965                 return;
1966             }
1967             usb_packet_copy(p, &params, cmd.argc * sizeof(uint32_t));
1968             for (i = 0; i < cmd.argc; i++) {
1969                 cmd.argv[i] = le32_to_cpu(params[i]);
1970             }
1971             trace_usb_mtp_command(s->dev.addr, cmd.code, cmd.trans,
1972                                   (cmd.argc > 0) ? cmd.argv[0] : 0,
1973                                   (cmd.argc > 1) ? cmd.argv[1] : 0,
1974                                   (cmd.argc > 2) ? cmd.argv[2] : 0,
1975                                   (cmd.argc > 3) ? cmd.argv[3] : 0,
1976                                   (cmd.argc > 4) ? cmd.argv[4] : 0);
1977             usb_mtp_command(s, &cmd);
1978             break;
1979         case TYPE_DATA:
1980             /* One of the previous transfers has already errored but the
1981              * responder is still sending data associated with it
1982              */
1983             if (s->result != NULL) {
1984                 return;
1985             }
1986             usb_mtp_get_data(s, &container, p);
1987             break;
1988         default:
1989             /* not needed as long as the mtp device is read-only */
1990             p->status = USB_RET_STALL;
1991             return;
1992         }
1993         break;
1994     case EP_EVENT:
1995         if (!QTAILQ_EMPTY(&s->events)) {
1996             struct MTPMonEntry *e = QTAILQ_LAST(&s->events);
1997             uint32_t handle;
1998             int len = sizeof(container) + sizeof(uint32_t);
1999
2000             if (p->iov.size < len) {
2001                 trace_usb_mtp_stall(s->dev.addr,
2002                                     "packet too small to send event");
2003                 p->status = USB_RET_STALL;
2004                 return;
2005             }
2006
2007             QTAILQ_REMOVE(&s->events, e, next);
2008             container.length = cpu_to_le32(len);
2009             container.type = cpu_to_le32(TYPE_EVENT);
2010             container.code = cpu_to_le16(e->event);
2011             container.trans = 0; /* no trans specific events */
2012             handle = cpu_to_le32(e->handle);
2013             usb_packet_copy(p, &container, sizeof(container));
2014             usb_packet_copy(p, &handle, sizeof(uint32_t));
2015             g_free(e);
2016             return;
2017         }
2018         p->status = USB_RET_NAK;
2019         return;
2020     default:
2021         trace_usb_mtp_stall(s->dev.addr, "invalid endpoint");
2022         p->status = USB_RET_STALL;
2023         return;
2024     }
2025
2026     if (p->actual_length == 0) {
2027         trace_usb_mtp_nak(s->dev.addr, p->ep->nr);
2028         p->status = USB_RET_NAK;
2029         return;
2030     } else {
2031         trace_usb_mtp_xfer(s->dev.addr, p->ep->nr, p->actual_length,
2032                            p->iov.size);
2033         return;
2034     }
2035 }
2036
2037 static void usb_mtp_realize(USBDevice *dev, Error **errp)
2038 {
2039     MTPState *s = USB_MTP(dev);
2040
2041     if ((s->root == NULL) || !g_path_is_absolute(s->root)) {
2042         error_setg(errp, "usb-mtp: rootdir must be configured and be an absolute path");
2043         return;
2044     }
2045
2046     if (access(s->root, R_OK) != 0) {
2047         error_setg(errp, "usb-mtp: rootdir does not exist/not readable");
2048         return;
2049     } else if (!s->readonly && access(s->root, W_OK) != 0) {
2050         error_setg(errp, "usb-mtp: rootdir does not have write permissions");
2051         return;
2052     }
2053
2054     /* Mark store as RW */
2055     if (!s->readonly) {
2056         s->flags |= (1 << MTP_FLAG_WRITABLE);
2057     }
2058
2059     if (s->desc == NULL) {
2060         /*
2061          * This does not check if path exists
2062          * but we have the checks above
2063          */
2064         s->desc = g_path_get_basename(s->root);
2065     }
2066
2067     usb_desc_create_serial(dev);
2068     usb_desc_init(dev);
2069     QTAILQ_INIT(&s->objects);
2070
2071 }
2072
2073 static const VMStateDescription vmstate_usb_mtp = {
2074     .name = "usb-mtp",
2075     .unmigratable = 1,
2076     .version_id = 1,
2077     .minimum_version_id = 1,
2078     .fields = (VMStateField[]) {
2079         VMSTATE_USB_DEVICE(dev, MTPState),
2080         VMSTATE_END_OF_LIST()
2081     }
2082 };
2083
2084 static Property mtp_properties[] = {
2085     DEFINE_PROP_STRING("rootdir", MTPState, root),
2086     DEFINE_PROP_STRING("desc", MTPState, desc),
2087     DEFINE_PROP_BOOL("readonly", MTPState, readonly, true),
2088     DEFINE_PROP_END_OF_LIST(),
2089 };
2090
2091 static void usb_mtp_class_initfn(ObjectClass *klass, void *data)
2092 {
2093     DeviceClass *dc = DEVICE_CLASS(klass);
2094     USBDeviceClass *uc = USB_DEVICE_CLASS(klass);
2095
2096     uc->realize        = usb_mtp_realize;
2097     uc->product_desc   = "QEMU USB MTP";
2098     uc->usb_desc       = &desc;
2099     uc->cancel_packet  = usb_mtp_cancel_packet;
2100     uc->handle_attach  = usb_desc_attach;
2101     uc->handle_reset   = usb_mtp_handle_reset;
2102     uc->handle_control = usb_mtp_handle_control;
2103     uc->handle_data    = usb_mtp_handle_data;
2104     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
2105     dc->desc = "USB Media Transfer Protocol device";
2106     dc->fw_name = "mtp";
2107     dc->vmsd = &vmstate_usb_mtp;
2108     device_class_set_props(dc, mtp_properties);
2109 }
2110
2111 static TypeInfo mtp_info = {
2112     .name          = TYPE_USB_MTP,
2113     .parent        = TYPE_USB_DEVICE,
2114     .instance_size = sizeof(MTPState),
2115     .class_init    = usb_mtp_class_initfn,
2116 };
2117
2118 static void usb_mtp_register_types(void)
2119 {
2120     type_register_static(&mtp_info);
2121 }
2122
2123 type_init(usb_mtp_register_types)