cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

dev-mtp.c (62512B)


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