xref: /openbmc/qemu/hw/usb/dev-mtp.c (revision 650d103d3ea959212f826acb9d3fe80cf30e347b)
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/usb.h"
27 #include "migration/vmstate.h"
28 #include "desc.h"
29 #include "qemu/units.h"
30 
31 /* ----------------------------------------------------------------------- */
32 
33 enum mtp_container_type {
34     TYPE_COMMAND  = 1,
35     TYPE_DATA     = 2,
36     TYPE_RESPONSE = 3,
37     TYPE_EVENT    = 4,
38 };
39 
40 /* MTP write stage, for internal use only */
41 enum mtp_write_status {
42     WRITE_START    = 1,
43     WRITE_CONTINUE = 2,
44     WRITE_END      = 3,
45 };
46 
47 enum mtp_code {
48     /* command codes */
49     CMD_GET_DEVICE_INFO            = 0x1001,
50     CMD_OPEN_SESSION               = 0x1002,
51     CMD_CLOSE_SESSION              = 0x1003,
52     CMD_GET_STORAGE_IDS            = 0x1004,
53     CMD_GET_STORAGE_INFO           = 0x1005,
54     CMD_GET_NUM_OBJECTS            = 0x1006,
55     CMD_GET_OBJECT_HANDLES         = 0x1007,
56     CMD_GET_OBJECT_INFO            = 0x1008,
57     CMD_GET_OBJECT                 = 0x1009,
58     CMD_DELETE_OBJECT              = 0x100b,
59     CMD_SEND_OBJECT_INFO           = 0x100c,
60     CMD_SEND_OBJECT                = 0x100d,
61     CMD_GET_PARTIAL_OBJECT         = 0x101b,
62     CMD_GET_OBJECT_PROPS_SUPPORTED = 0x9801,
63     CMD_GET_OBJECT_PROP_DESC       = 0x9802,
64     CMD_GET_OBJECT_PROP_VALUE      = 0x9803,
65 
66     /* response codes */
67     RES_OK                         = 0x2001,
68     RES_GENERAL_ERROR              = 0x2002,
69     RES_SESSION_NOT_OPEN           = 0x2003,
70     RES_INVALID_TRANSACTION_ID     = 0x2004,
71     RES_OPERATION_NOT_SUPPORTED    = 0x2005,
72     RES_PARAMETER_NOT_SUPPORTED    = 0x2006,
73     RES_INCOMPLETE_TRANSFER        = 0x2007,
74     RES_INVALID_STORAGE_ID         = 0x2008,
75     RES_INVALID_OBJECT_HANDLE      = 0x2009,
76     RES_INVALID_OBJECT_FORMAT_CODE = 0x200b,
77     RES_STORE_FULL                 = 0x200c,
78     RES_STORE_READ_ONLY            = 0x200e,
79     RES_PARTIAL_DELETE             = 0x2012,
80     RES_STORE_NOT_AVAILABLE        = 0x2013,
81     RES_SPEC_BY_FORMAT_UNSUPPORTED = 0x2014,
82     RES_INVALID_OBJECTINFO         = 0x2015,
83     RES_DESTINATION_UNSUPPORTED    = 0x2020,
84     RES_INVALID_PARENT_OBJECT      = 0x201a,
85     RES_INVALID_PARAMETER          = 0x201d,
86     RES_SESSION_ALREADY_OPEN       = 0x201e,
87     RES_INVALID_OBJECT_PROP_CODE   = 0xA801,
88 
89     /* format codes */
90     FMT_UNDEFINED_OBJECT           = 0x3000,
91     FMT_ASSOCIATION                = 0x3001,
92 
93     /* event codes */
94     EVT_CANCEL_TRANSACTION         = 0x4001,
95     EVT_OBJ_ADDED                  = 0x4002,
96     EVT_OBJ_REMOVED                = 0x4003,
97     EVT_OBJ_INFO_CHANGED           = 0x4007,
98 
99     /* object properties */
100     PROP_STORAGE_ID                = 0xDC01,
101     PROP_OBJECT_FORMAT             = 0xDC02,
102     PROP_OBJECT_COMPRESSED_SIZE    = 0xDC04,
103     PROP_PARENT_OBJECT             = 0xDC0B,
104     PROP_PERSISTENT_UNIQUE_OBJECT_IDENTIFIER = 0xDC41,
105     PROP_NAME                      = 0xDC44,
106 };
107 
108 enum mtp_data_type {
109     DATA_TYPE_UINT16  = 0x0004,
110     DATA_TYPE_UINT32  = 0x0006,
111     DATA_TYPE_UINT64  = 0x0008,
112     DATA_TYPE_UINT128 = 0x000a,
113     DATA_TYPE_STRING  = 0xffff,
114 };
115 
116 typedef struct {
117     uint32_t length;
118     uint16_t type;
119     uint16_t code;
120     uint32_t trans;
121 } QEMU_PACKED mtp_container;
122 
123 /* ----------------------------------------------------------------------- */
124 
125 typedef struct MTPState MTPState;
126 typedef struct MTPControl MTPControl;
127 typedef struct MTPData MTPData;
128 typedef struct MTPObject MTPObject;
129 
130 enum {
131     EP_DATA_IN = 1,
132     EP_DATA_OUT,
133     EP_EVENT,
134 };
135 
136 typedef struct MTPMonEntry MTPMonEntry;
137 
138 struct MTPMonEntry {
139     uint32_t event;
140     uint32_t handle;
141 
142     QTAILQ_ENTRY(MTPMonEntry) next;
143 };
144 
145 struct MTPControl {
146     uint16_t     code;
147     uint32_t     trans;
148     int          argc;
149     uint32_t     argv[5];
150 };
151 
152 struct MTPData {
153     uint16_t     code;
154     uint32_t     trans;
155     uint64_t     offset;
156     uint64_t     length;
157     uint64_t     alloc;
158     uint8_t      *data;
159     bool         first;
160     /* Used for >4G file sizes */
161     bool         pending;
162     int          fd;
163     uint8_t      write_status;
164     /* Internal pointer per every MTP_WRITE_BUF_SZ */
165     uint64_t     data_offset;
166 };
167 
168 struct MTPObject {
169     uint32_t     handle;
170     uint16_t     format;
171     char         *name;
172     char         *path;
173     struct stat  stat;
174     /* file monitor watch id */
175     int64_t      watchid;
176     MTPObject    *parent;
177     uint32_t     nchildren;
178     QLIST_HEAD(, MTPObject) children;
179     QLIST_ENTRY(MTPObject) list;
180     bool         have_children;
181     QTAILQ_ENTRY(MTPObject) next;
182 };
183 
184 struct MTPState {
185     USBDevice    dev;
186     char         *root;
187     char         *desc;
188     uint32_t     flags;
189 
190     MTPData      *data_in;
191     MTPData      *data_out;
192     MTPControl   *result;
193     uint32_t     session;
194     uint32_t     next_handle;
195     bool         readonly;
196 
197     QTAILQ_HEAD(, MTPObject) objects;
198     QFileMonitor *file_monitor;
199     QTAILQ_HEAD(, MTPMonEntry) events;
200     /* Responder is expecting a write operation */
201     bool write_pending;
202     struct {
203         uint32_t parent_handle;
204         uint16_t format;
205         uint32_t size;
206         char *filename;
207     } dataset;
208 };
209 
210 /*
211  * ObjectInfo dataset received from initiator
212  * Fields we don't care about are ignored
213  */
214 typedef struct {
215     uint32_t storage_id; /*unused*/
216     uint16_t format;
217     uint16_t protection_status; /*unused*/
218     uint32_t size;
219     uint16_t thumb_format; /*unused*/
220     uint32_t thumb_comp_sz; /*unused*/
221     uint32_t thumb_pix_width; /*unused*/
222     uint32_t thumb_pix_height; /*unused*/
223     uint32_t image_pix_width; /*unused*/
224     uint32_t image_pix_height; /*unused*/
225     uint32_t image_bit_depth; /*unused*/
226     uint32_t parent; /*unused*/
227     uint16_t assoc_type;
228     uint32_t assoc_desc;
229     uint32_t seq_no; /*unused*/
230     uint8_t length; /*part of filename field*/
231     uint8_t filename[0]; /* UTF-16 encoded */
232     char date_created[0]; /*unused*/
233     char date_modified[0]; /*unused*/
234     char keywords[0]; /*unused*/
235     /* string and other data follows */
236 } QEMU_PACKED ObjectInfo;
237 
238 #define TYPE_USB_MTP "usb-mtp"
239 #define USB_MTP(obj) OBJECT_CHECK(MTPState, (obj), TYPE_USB_MTP)
240 
241 #define QEMU_STORAGE_ID 0x00010001
242 
243 #define MTP_FLAG_WRITABLE 0
244 
245 #define FLAG_SET(_mtp, _flag)  ((_mtp)->flags & (1 << (_flag)))
246 
247 /* ----------------------------------------------------------------------- */
248 
249 #define MTP_MANUFACTURER  "QEMU"
250 #define MTP_PRODUCT       "QEMU filesharing"
251 #define MTP_WRITE_BUF_SZ  (512 * KiB)
252 
253 enum {
254     STR_MANUFACTURER = 1,
255     STR_PRODUCT,
256     STR_SERIALNUMBER,
257     STR_MTP,
258     STR_CONFIG_FULL,
259     STR_CONFIG_HIGH,
260     STR_CONFIG_SUPER,
261 };
262 
263 static const USBDescStrings desc_strings = {
264     [STR_MANUFACTURER] = MTP_MANUFACTURER,
265     [STR_PRODUCT]      = MTP_PRODUCT,
266     [STR_SERIALNUMBER] = "34617",
267     [STR_MTP]          = "MTP",
268     [STR_CONFIG_FULL]  = "Full speed config (usb 1.1)",
269     [STR_CONFIG_HIGH]  = "High speed config (usb 2.0)",
270     [STR_CONFIG_SUPER] = "Super speed config (usb 3.0)",
271 };
272 
273 static const USBDescIface desc_iface_full = {
274     .bInterfaceNumber              = 0,
275     .bNumEndpoints                 = 3,
276     .bInterfaceClass               = USB_CLASS_STILL_IMAGE,
277     .bInterfaceSubClass            = 0x01,
278     .bInterfaceProtocol            = 0x01,
279     .iInterface                    = STR_MTP,
280     .eps = (USBDescEndpoint[]) {
281         {
282             .bEndpointAddress      = USB_DIR_IN | EP_DATA_IN,
283             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
284             .wMaxPacketSize        = 64,
285         },{
286             .bEndpointAddress      = USB_DIR_OUT | EP_DATA_OUT,
287             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
288             .wMaxPacketSize        = 64,
289         },{
290             .bEndpointAddress      = USB_DIR_IN | EP_EVENT,
291             .bmAttributes          = USB_ENDPOINT_XFER_INT,
292             .wMaxPacketSize        = 64,
293             .bInterval             = 0x0a,
294         },
295     }
296 };
297 
298 static const USBDescDevice desc_device_full = {
299     .bcdUSB                        = 0x0200,
300     .bMaxPacketSize0               = 8,
301     .bNumConfigurations            = 1,
302     .confs = (USBDescConfig[]) {
303         {
304             .bNumInterfaces        = 1,
305             .bConfigurationValue   = 1,
306             .iConfiguration        = STR_CONFIG_FULL,
307             .bmAttributes          = USB_CFG_ATT_ONE | USB_CFG_ATT_WAKEUP,
308             .bMaxPower             = 2,
309             .nif = 1,
310             .ifs = &desc_iface_full,
311         },
312     },
313 };
314 
315 static const USBDescIface desc_iface_high = {
316     .bInterfaceNumber              = 0,
317     .bNumEndpoints                 = 3,
318     .bInterfaceClass               = USB_CLASS_STILL_IMAGE,
319     .bInterfaceSubClass            = 0x01,
320     .bInterfaceProtocol            = 0x01,
321     .iInterface                    = STR_MTP,
322     .eps = (USBDescEndpoint[]) {
323         {
324             .bEndpointAddress      = USB_DIR_IN | EP_DATA_IN,
325             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
326             .wMaxPacketSize        = 512,
327         },{
328             .bEndpointAddress      = USB_DIR_OUT | EP_DATA_OUT,
329             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
330             .wMaxPacketSize        = 512,
331         },{
332             .bEndpointAddress      = USB_DIR_IN | EP_EVENT,
333             .bmAttributes          = USB_ENDPOINT_XFER_INT,
334             .wMaxPacketSize        = 64,
335             .bInterval             = 0x0a,
336         },
337     }
338 };
339 
340 static const USBDescDevice desc_device_high = {
341     .bcdUSB                        = 0x0200,
342     .bMaxPacketSize0               = 64,
343     .bNumConfigurations            = 1,
344     .confs = (USBDescConfig[]) {
345         {
346             .bNumInterfaces        = 1,
347             .bConfigurationValue   = 1,
348             .iConfiguration        = STR_CONFIG_HIGH,
349             .bmAttributes          = USB_CFG_ATT_ONE | USB_CFG_ATT_WAKEUP,
350             .bMaxPower             = 2,
351             .nif = 1,
352             .ifs = &desc_iface_high,
353         },
354     },
355 };
356 
357 static const USBDescMSOS desc_msos = {
358     .CompatibleID = "MTP",
359     .SelectiveSuspendEnabled = true,
360 };
361 
362 static const USBDesc desc = {
363     .id = {
364         .idVendor          = 0x46f4, /* CRC16() of "QEMU" */
365         .idProduct         = 0x0004,
366         .bcdDevice         = 0,
367         .iManufacturer     = STR_MANUFACTURER,
368         .iProduct          = STR_PRODUCT,
369         .iSerialNumber     = STR_SERIALNUMBER,
370     },
371     .full  = &desc_device_full,
372     .high  = &desc_device_high,
373     .str   = desc_strings,
374     .msos  = &desc_msos,
375 };
376 
377 /* ----------------------------------------------------------------------- */
378 
379 static MTPObject *usb_mtp_object_alloc(MTPState *s, uint32_t handle,
380                                        MTPObject *parent, const char *name)
381 {
382     MTPObject *o = g_new0(MTPObject, 1);
383 
384     if (name[0] == '.') {
385         goto ignore;
386     }
387 
388     o->watchid = -1;
389     o->handle = handle;
390     o->parent = parent;
391     o->name = g_strdup(name);
392     if (parent == NULL) {
393         o->path = g_strdup(name);
394     } else {
395         o->path = g_strdup_printf("%s/%s", parent->path, name);
396     }
397 
398     if (lstat(o->path, &o->stat) != 0) {
399         goto ignore;
400     }
401     if (S_ISREG(o->stat.st_mode)) {
402         o->format = FMT_UNDEFINED_OBJECT;
403     } else if (S_ISDIR(o->stat.st_mode)) {
404         o->format = FMT_ASSOCIATION;
405     } else {
406         goto ignore;
407     }
408 
409     if (access(o->path, R_OK) != 0) {
410         goto ignore;
411     }
412 
413     trace_usb_mtp_object_alloc(s->dev.addr, o->handle, o->path);
414 
415     QTAILQ_INSERT_TAIL(&s->objects, o, next);
416     return o;
417 
418 ignore:
419     g_free(o->name);
420     g_free(o->path);
421     g_free(o);
422     return NULL;
423 }
424 
425 static void usb_mtp_object_free(MTPState *s, MTPObject *o)
426 {
427     MTPObject *iter;
428 
429     if (!o) {
430         return;
431     }
432 
433     trace_usb_mtp_object_free(s->dev.addr, o->handle, o->path);
434 
435     if (o->watchid != -1 && s->file_monitor) {
436         qemu_file_monitor_remove_watch(s->file_monitor, o->path, o->watchid);
437     }
438 
439     QTAILQ_REMOVE(&s->objects, o, next);
440     if (o->parent) {
441         QLIST_REMOVE(o, list);
442         o->parent->nchildren--;
443     }
444 
445     while (!QLIST_EMPTY(&o->children)) {
446         iter = QLIST_FIRST(&o->children);
447         usb_mtp_object_free(s, iter);
448     }
449     g_free(o->name);
450     g_free(o->path);
451     g_free(o);
452 }
453 
454 static MTPObject *usb_mtp_object_lookup(MTPState *s, uint32_t handle)
455 {
456     MTPObject *o;
457 
458     QTAILQ_FOREACH(o, &s->objects, next) {
459         if (o->handle == handle) {
460             return o;
461         }
462     }
463     return NULL;
464 }
465 
466 static MTPObject *usb_mtp_add_child(MTPState *s, MTPObject *o,
467                                     const char *name)
468 {
469     MTPObject *child =
470         usb_mtp_object_alloc(s, s->next_handle++, o, name);
471 
472     if (child) {
473         trace_usb_mtp_add_child(s->dev.addr, child->handle, child->path);
474         QLIST_INSERT_HEAD(&o->children, child, list);
475         o->nchildren++;
476 
477         if (child->format == FMT_ASSOCIATION) {
478             QLIST_INIT(&child->children);
479         }
480     }
481 
482     return child;
483 }
484 
485 static MTPObject *usb_mtp_object_lookup_name(MTPObject *parent,
486                                              const char *name, int len)
487 {
488     MTPObject *iter;
489 
490     if (len == -1) {
491         len = strlen(name);
492     }
493 
494     QLIST_FOREACH(iter, &parent->children, list) {
495         if (strncmp(iter->name, name, len) == 0) {
496             return iter;
497         }
498     }
499 
500     return NULL;
501 }
502 
503 static MTPObject *usb_mtp_object_lookup_id(MTPState *s, int64_t id)
504 {
505     MTPObject *iter;
506 
507     QTAILQ_FOREACH(iter, &s->objects, next) {
508         if (iter->watchid == id) {
509             return iter;
510         }
511     }
512 
513     return NULL;
514 }
515 
516 static void file_monitor_event(int64_t id,
517                                QFileMonitorEvent ev,
518                                const char *name,
519                                void *opaque)
520 {
521     MTPState *s = opaque;
522     MTPObject *parent = usb_mtp_object_lookup_id(s, id);
523     MTPMonEntry *entry = NULL;
524     MTPObject *o;
525 
526     if (!parent) {
527         return;
528     }
529 
530     switch (ev) {
531     case QFILE_MONITOR_EVENT_CREATED:
532         if (usb_mtp_object_lookup_name(parent, name, -1)) {
533             /* Duplicate create event */
534             return;
535         }
536         entry = g_new0(MTPMonEntry, 1);
537         entry->handle = s->next_handle;
538         entry->event = EVT_OBJ_ADDED;
539         o = usb_mtp_add_child(s, parent, name);
540         if (!o) {
541             g_free(entry);
542             return;
543         }
544         trace_usb_mtp_file_monitor_event(s->dev.addr, name, "Obj Added");
545         break;
546 
547     case QFILE_MONITOR_EVENT_DELETED:
548         /*
549          * The kernel issues a IN_IGNORED event
550          * when a dir containing a watchpoint is
551          * deleted, so we don't have to delete the
552          * watchpoint
553          */
554         o = usb_mtp_object_lookup_name(parent, name, -1);
555         if (!o) {
556             return;
557         }
558         entry = g_new0(MTPMonEntry, 1);
559         entry->handle = o->handle;
560         entry->event = EVT_OBJ_REMOVED;
561         trace_usb_mtp_file_monitor_event(s->dev.addr, o->path, "Obj Deleted");
562         usb_mtp_object_free(s, o);
563         break;
564 
565     case QFILE_MONITOR_EVENT_MODIFIED:
566         o = usb_mtp_object_lookup_name(parent, name, -1);
567         if (!o) {
568             return;
569         }
570         entry = g_new0(MTPMonEntry, 1);
571         entry->handle = o->handle;
572         entry->event = EVT_OBJ_INFO_CHANGED;
573         trace_usb_mtp_file_monitor_event(s->dev.addr, o->path, "Obj Modified");
574         break;
575 
576     case QFILE_MONITOR_EVENT_IGNORED:
577         trace_usb_mtp_file_monitor_event(s->dev.addr, parent->path,
578                                     "Obj parent dir ignored");
579         break;
580 
581     case QFILE_MONITOR_EVENT_ATTRIBUTES:
582         break;
583 
584     default:
585         g_assert_not_reached();
586     }
587 
588     if (entry) {
589         QTAILQ_INSERT_HEAD(&s->events, entry, next);
590     }
591 }
592 
593 static void usb_mtp_file_monitor_cleanup(MTPState *s)
594 {
595     MTPMonEntry *e, *p;
596 
597     QTAILQ_FOREACH_SAFE(e, &s->events, next, p) {
598         QTAILQ_REMOVE(&s->events, e, next);
599         g_free(e);
600     }
601 
602     qemu_file_monitor_free(s->file_monitor);
603     s->file_monitor = NULL;
604 }
605 
606 
607 static void usb_mtp_object_readdir(MTPState *s, MTPObject *o)
608 {
609     struct dirent *entry;
610     DIR *dir;
611     int fd;
612     Error *err = NULL;
613 
614     if (o->have_children) {
615         return;
616     }
617     o->have_children = true;
618 
619     fd = open(o->path, O_DIRECTORY | O_CLOEXEC | O_NOFOLLOW);
620     if (fd < 0) {
621         return;
622     }
623     dir = fdopendir(fd);
624     if (!dir) {
625         close(fd);
626         return;
627     }
628 
629     if (s->file_monitor) {
630         int64_t id = qemu_file_monitor_add_watch(s->file_monitor, o->path, NULL,
631                                                  file_monitor_event, s, &err);
632         if (id == -1) {
633             error_report("usb-mtp: failed to add watch for %s: %s", o->path,
634                          error_get_pretty(err));
635             error_free(err);
636         } else {
637             trace_usb_mtp_file_monitor_event(s->dev.addr, o->path,
638                                              "Watch Added");
639             o->watchid = id;
640         }
641     }
642 
643     while ((entry = readdir(dir)) != NULL) {
644         usb_mtp_add_child(s, o, entry->d_name);
645     }
646     closedir(dir);
647 }
648 
649 /* ----------------------------------------------------------------------- */
650 
651 static MTPData *usb_mtp_data_alloc(MTPControl *c)
652 {
653     MTPData *data = g_new0(MTPData, 1);
654 
655     data->code  = c->code;
656     data->trans = c->trans;
657     data->fd    = -1;
658     data->first = true;
659     return data;
660 }
661 
662 static void usb_mtp_data_free(MTPData *data)
663 {
664     if (data == NULL) {
665         return;
666     }
667     if (data->fd != -1) {
668         close(data->fd);
669     }
670     g_free(data->data);
671     g_free(data);
672 }
673 
674 static void usb_mtp_realloc(MTPData *data, uint32_t bytes)
675 {
676     if (data->length + bytes <= data->alloc) {
677         return;
678     }
679     data->alloc = (data->length + bytes + 0xff) & ~0xff;
680     data->data  = g_realloc(data->data, data->alloc);
681 }
682 
683 static void usb_mtp_add_u8(MTPData *data, uint8_t val)
684 {
685     usb_mtp_realloc(data, 1);
686     data->data[data->length++] = val;
687 }
688 
689 static void usb_mtp_add_u16(MTPData *data, uint16_t val)
690 {
691     usb_mtp_realloc(data, 2);
692     data->data[data->length++] = (val >> 0) & 0xff;
693     data->data[data->length++] = (val >> 8) & 0xff;
694 }
695 
696 static void usb_mtp_add_u32(MTPData *data, uint32_t val)
697 {
698     usb_mtp_realloc(data, 4);
699     data->data[data->length++] = (val >>  0) & 0xff;
700     data->data[data->length++] = (val >>  8) & 0xff;
701     data->data[data->length++] = (val >> 16) & 0xff;
702     data->data[data->length++] = (val >> 24) & 0xff;
703 }
704 
705 static void usb_mtp_add_u64(MTPData *data, uint64_t val)
706 {
707     usb_mtp_realloc(data, 8);
708     data->data[data->length++] = (val >>  0) & 0xff;
709     data->data[data->length++] = (val >>  8) & 0xff;
710     data->data[data->length++] = (val >> 16) & 0xff;
711     data->data[data->length++] = (val >> 24) & 0xff;
712     data->data[data->length++] = (val >> 32) & 0xff;
713     data->data[data->length++] = (val >> 40) & 0xff;
714     data->data[data->length++] = (val >> 48) & 0xff;
715     data->data[data->length++] = (val >> 56) & 0xff;
716 }
717 
718 static void usb_mtp_add_u16_array(MTPData *data, uint32_t len,
719                                   const uint16_t *vals)
720 {
721     int i;
722 
723     usb_mtp_add_u32(data, len);
724     for (i = 0; i < len; i++) {
725         usb_mtp_add_u16(data, vals[i]);
726     }
727 }
728 
729 static void usb_mtp_add_u32_array(MTPData *data, uint32_t len,
730                                   const uint32_t *vals)
731 {
732     int i;
733 
734     usb_mtp_add_u32(data, len);
735     for (i = 0; i < len; i++) {
736         usb_mtp_add_u32(data, vals[i]);
737     }
738 }
739 
740 static void usb_mtp_add_wstr(MTPData *data, const wchar_t *str)
741 {
742     uint32_t len = wcslen(str);
743     int i;
744 
745     if (len > 0) {
746         len++; /* include terminating L'\0' */
747     }
748 
749     usb_mtp_add_u8(data, len);
750     for (i = 0; i < len; i++) {
751         usb_mtp_add_u16(data, str[i]);
752     }
753 }
754 
755 static void usb_mtp_add_str(MTPData *data, const char *str)
756 {
757     uint32_t len = strlen(str)+1;
758     wchar_t *wstr = g_new(wchar_t, len);
759     size_t ret;
760 
761     ret = mbstowcs(wstr, str, len);
762     if (ret == -1) {
763         usb_mtp_add_wstr(data, L"Oops");
764     } else {
765         usb_mtp_add_wstr(data, wstr);
766     }
767 
768     g_free(wstr);
769 }
770 
771 static void usb_mtp_add_time(MTPData *data, time_t time)
772 {
773     char buf[16];
774     struct tm tm;
775 
776     gmtime_r(&time, &tm);
777     strftime(buf, sizeof(buf), "%Y%m%dT%H%M%S", &tm);
778     usb_mtp_add_str(data, buf);
779 }
780 
781 /* ----------------------------------------------------------------------- */
782 
783 static void usb_mtp_queue_result(MTPState *s, uint16_t code, uint32_t trans,
784                                  int argc, uint32_t arg0, uint32_t arg1,
785                                  uint32_t arg2)
786 {
787     MTPControl *c = g_new0(MTPControl, 1);
788 
789     c->code  = code;
790     c->trans = trans;
791     c->argc  = argc;
792     if (argc > 0) {
793         c->argv[0] = arg0;
794     }
795     if (argc > 1) {
796         c->argv[1] = arg1;
797     }
798     if (argc > 2) {
799         c->argv[2] = arg2;
800     }
801 
802     assert(s->result == NULL);
803     s->result = c;
804 }
805 
806 /* ----------------------------------------------------------------------- */
807 
808 static MTPData *usb_mtp_get_device_info(MTPState *s, MTPControl *c)
809 {
810     static const uint16_t ops[] = {
811         CMD_GET_DEVICE_INFO,
812         CMD_OPEN_SESSION,
813         CMD_CLOSE_SESSION,
814         CMD_GET_STORAGE_IDS,
815         CMD_GET_STORAGE_INFO,
816         CMD_GET_NUM_OBJECTS,
817         CMD_GET_OBJECT_HANDLES,
818         CMD_GET_OBJECT_INFO,
819         CMD_DELETE_OBJECT,
820         CMD_SEND_OBJECT_INFO,
821         CMD_SEND_OBJECT,
822         CMD_GET_OBJECT,
823         CMD_GET_PARTIAL_OBJECT,
824         CMD_GET_OBJECT_PROPS_SUPPORTED,
825         CMD_GET_OBJECT_PROP_DESC,
826         CMD_GET_OBJECT_PROP_VALUE,
827     };
828     static const uint16_t fmt[] = {
829         FMT_UNDEFINED_OBJECT,
830         FMT_ASSOCIATION,
831     };
832     MTPData *d = usb_mtp_data_alloc(c);
833 
834     trace_usb_mtp_op_get_device_info(s->dev.addr);
835 
836     usb_mtp_add_u16(d, 100);
837     usb_mtp_add_u32(d, 0x00000006);
838     usb_mtp_add_u16(d, 0x0064);
839     usb_mtp_add_wstr(d, L"");
840     usb_mtp_add_u16(d, 0x0000);
841 
842     usb_mtp_add_u16_array(d, ARRAY_SIZE(ops), ops);
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, 0, NULL);
846     usb_mtp_add_u16_array(d, ARRAY_SIZE(fmt), fmt);
847 
848     usb_mtp_add_wstr(d, L"" MTP_MANUFACTURER);
849     usb_mtp_add_wstr(d, L"" MTP_PRODUCT);
850     usb_mtp_add_wstr(d, L"0.1");
851     usb_mtp_add_wstr(d, L"0123456789abcdef0123456789abcdef");
852 
853     return d;
854 }
855 
856 static MTPData *usb_mtp_get_storage_ids(MTPState *s, MTPControl *c)
857 {
858     static const uint32_t ids[] = {
859         QEMU_STORAGE_ID,
860     };
861     MTPData *d = usb_mtp_data_alloc(c);
862 
863     trace_usb_mtp_op_get_storage_ids(s->dev.addr);
864 
865     usb_mtp_add_u32_array(d, ARRAY_SIZE(ids), ids);
866 
867     return d;
868 }
869 
870 static MTPData *usb_mtp_get_storage_info(MTPState *s, MTPControl *c)
871 {
872     MTPData *d = usb_mtp_data_alloc(c);
873     struct statvfs buf;
874     int rc;
875 
876     trace_usb_mtp_op_get_storage_info(s->dev.addr);
877 
878     if (FLAG_SET(s, MTP_FLAG_WRITABLE)) {
879         usb_mtp_add_u16(d, 0x0003);
880         usb_mtp_add_u16(d, 0x0002);
881         usb_mtp_add_u16(d, 0x0000);
882     } else {
883         usb_mtp_add_u16(d, 0x0001);
884         usb_mtp_add_u16(d, 0x0002);
885         usb_mtp_add_u16(d, 0x0001);
886     }
887 
888     rc = statvfs(s->root, &buf);
889     if (rc == 0) {
890         usb_mtp_add_u64(d, (uint64_t)buf.f_frsize * buf.f_blocks);
891         usb_mtp_add_u64(d, (uint64_t)buf.f_bavail * buf.f_blocks);
892         usb_mtp_add_u32(d, buf.f_ffree);
893     } else {
894         usb_mtp_add_u64(d, 0xffffffff);
895         usb_mtp_add_u64(d, 0xffffffff);
896         usb_mtp_add_u32(d, 0xffffffff);
897     }
898 
899     usb_mtp_add_str(d, s->desc);
900     usb_mtp_add_wstr(d, L"123456789abcdef");
901     return d;
902 }
903 
904 static MTPData *usb_mtp_get_object_handles(MTPState *s, MTPControl *c,
905                                            MTPObject *o)
906 {
907     MTPData *d = usb_mtp_data_alloc(c);
908     uint32_t i = 0, handles[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 
922 static 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 
970 static 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 
988 static 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 
1024 static 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 
1040 static 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 
1101 static 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  */
1149 enum {
1150     DELETE_SUCCESS = (1 << 0),
1151     DELETE_FAILURE = (1 << 1),
1152     DELETE_PARTIAL = (DELETE_FAILURE | DELETE_SUCCESS),
1153 };
1154 
1155 static 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 
1191 static 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 
1242 static 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_report("usb-mtp: file monitoring init failed: %s",
1279                          error_get_pretty(err));
1280             error_free(err);
1281         } else {
1282             QTAILQ_INIT(&s->events);
1283         }
1284         break;
1285     case CMD_CLOSE_SESSION:
1286         trace_usb_mtp_op_close_session(s->dev.addr);
1287         s->session = 0;
1288         s->next_handle = 0;
1289         usb_mtp_file_monitor_cleanup(s);
1290         usb_mtp_object_free(s, QTAILQ_FIRST(&s->objects));
1291         assert(QTAILQ_EMPTY(&s->objects));
1292         break;
1293     case CMD_GET_STORAGE_IDS:
1294         data_in = usb_mtp_get_storage_ids(s, c);
1295         break;
1296     case CMD_GET_STORAGE_INFO:
1297         if (c->argv[0] != QEMU_STORAGE_ID &&
1298             c->argv[0] != 0xffffffff) {
1299             usb_mtp_queue_result(s, RES_INVALID_STORAGE_ID,
1300                                  c->trans, 0, 0, 0, 0);
1301             return;
1302         }
1303         data_in = usb_mtp_get_storage_info(s, c);
1304         break;
1305     case CMD_GET_NUM_OBJECTS:
1306     case CMD_GET_OBJECT_HANDLES:
1307         if (c->argv[0] != QEMU_STORAGE_ID &&
1308             c->argv[0] != 0xffffffff) {
1309             usb_mtp_queue_result(s, RES_INVALID_STORAGE_ID,
1310                                  c->trans, 0, 0, 0, 0);
1311             return;
1312         }
1313         if (c->argv[1] != 0x00000000) {
1314             usb_mtp_queue_result(s, RES_SPEC_BY_FORMAT_UNSUPPORTED,
1315                                  c->trans, 0, 0, 0, 0);
1316             return;
1317         }
1318         if (c->argv[2] == 0x00000000 ||
1319             c->argv[2] == 0xffffffff) {
1320             o = QTAILQ_FIRST(&s->objects);
1321         } else {
1322             o = usb_mtp_object_lookup(s, c->argv[2]);
1323         }
1324         if (o == NULL) {
1325             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1326                                  c->trans, 0, 0, 0, 0);
1327             return;
1328         }
1329         if (o->format != FMT_ASSOCIATION) {
1330             usb_mtp_queue_result(s, RES_INVALID_PARENT_OBJECT,
1331                                  c->trans, 0, 0, 0, 0);
1332             return;
1333         }
1334         usb_mtp_object_readdir(s, o);
1335         if (c->code == CMD_GET_NUM_OBJECTS) {
1336             trace_usb_mtp_op_get_num_objects(s->dev.addr, o->handle, o->path);
1337             nres = 1;
1338             res0 = o->nchildren;
1339         } else {
1340             data_in = usb_mtp_get_object_handles(s, c, o);
1341         }
1342         break;
1343     case CMD_GET_OBJECT_INFO:
1344         o = usb_mtp_object_lookup(s, c->argv[0]);
1345         if (o == NULL) {
1346             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1347                                  c->trans, 0, 0, 0, 0);
1348             return;
1349         }
1350         data_in = usb_mtp_get_object_info(s, c, o);
1351         break;
1352     case CMD_GET_OBJECT:
1353         o = usb_mtp_object_lookup(s, c->argv[0]);
1354         if (o == NULL) {
1355             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1356                                  c->trans, 0, 0, 0, 0);
1357             return;
1358         }
1359         if (o->format == FMT_ASSOCIATION) {
1360             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1361                                  c->trans, 0, 0, 0, 0);
1362             return;
1363         }
1364         data_in = usb_mtp_get_object(s, c, o);
1365         if (data_in == NULL) {
1366             usb_mtp_queue_result(s, RES_GENERAL_ERROR,
1367                                  c->trans, 0, 0, 0, 0);
1368             return;
1369         }
1370         break;
1371     case CMD_DELETE_OBJECT:
1372         usb_mtp_object_delete(s, c->argv[0], c->argv[1], c->trans);
1373         return;
1374     case CMD_GET_PARTIAL_OBJECT:
1375         o = usb_mtp_object_lookup(s, c->argv[0]);
1376         if (o == NULL) {
1377             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1378                                  c->trans, 0, 0, 0, 0);
1379             return;
1380         }
1381         if (o->format == FMT_ASSOCIATION) {
1382             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1383                                  c->trans, 0, 0, 0, 0);
1384             return;
1385         }
1386         data_in = usb_mtp_get_partial_object(s, c, o);
1387         if (data_in == NULL) {
1388             usb_mtp_queue_result(s, RES_GENERAL_ERROR,
1389                                  c->trans, 0, 0, 0, 0);
1390             return;
1391         }
1392         nres = 1;
1393         res0 = data_in->length;
1394         break;
1395     case CMD_SEND_OBJECT_INFO:
1396         /* Return error if store is read-only */
1397         if (!FLAG_SET(s, MTP_FLAG_WRITABLE)) {
1398             usb_mtp_queue_result(s, RES_STORE_READ_ONLY,
1399                                  c->trans, 0, 0, 0, 0);
1400         } else if (c->argv[0] && (c->argv[0] != QEMU_STORAGE_ID)) {
1401             /* First parameter points to storage id or is 0 */
1402             usb_mtp_queue_result(s, RES_STORE_NOT_AVAILABLE, c->trans,
1403                                  0, 0, 0, 0);
1404         } else if (c->argv[1] && !c->argv[0]) {
1405             /* If second parameter is specified, first must also be specified */
1406             usb_mtp_queue_result(s, RES_DESTINATION_UNSUPPORTED, c->trans,
1407                                  0, 0, 0, 0);
1408         } else {
1409             uint32_t handle = c->argv[1];
1410             if (handle == 0xFFFFFFFF || handle == 0) {
1411                 /* root object */
1412                 o = QTAILQ_FIRST(&s->objects);
1413             } else {
1414                 o = usb_mtp_object_lookup(s, handle);
1415             }
1416             if (o == NULL) {
1417                 usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE, c->trans,
1418                                      0, 0, 0, 0);
1419             } else if (o->format != FMT_ASSOCIATION) {
1420                 usb_mtp_queue_result(s, RES_INVALID_PARENT_OBJECT, c->trans,
1421                                      0, 0, 0, 0);
1422             }
1423         }
1424         if (o) {
1425             s->dataset.parent_handle = o->handle;
1426         }
1427         s->data_out = usb_mtp_data_alloc(c);
1428         return;
1429     case CMD_SEND_OBJECT:
1430         if (!FLAG_SET(s, MTP_FLAG_WRITABLE)) {
1431             usb_mtp_queue_result(s, RES_STORE_READ_ONLY,
1432                                  c->trans, 0, 0, 0, 0);
1433             return;
1434         }
1435         if (!s->write_pending) {
1436             usb_mtp_queue_result(s, RES_INVALID_OBJECTINFO,
1437                                  c->trans, 0, 0, 0, 0);
1438             return;
1439         }
1440         s->data_out = usb_mtp_data_alloc(c);
1441         return;
1442     case CMD_GET_OBJECT_PROPS_SUPPORTED:
1443         if (c->argv[0] != FMT_UNDEFINED_OBJECT &&
1444             c->argv[0] != FMT_ASSOCIATION) {
1445             usb_mtp_queue_result(s, RES_INVALID_OBJECT_FORMAT_CODE,
1446                                  c->trans, 0, 0, 0, 0);
1447             return;
1448         }
1449         data_in = usb_mtp_get_object_props_supported(s, c);
1450         break;
1451     case CMD_GET_OBJECT_PROP_DESC:
1452         if (c->argv[1] != FMT_UNDEFINED_OBJECT &&
1453             c->argv[1] != FMT_ASSOCIATION) {
1454             usb_mtp_queue_result(s, RES_INVALID_OBJECT_FORMAT_CODE,
1455                                  c->trans, 0, 0, 0, 0);
1456             return;
1457         }
1458         data_in = usb_mtp_get_object_prop_desc(s, c);
1459         if (data_in == NULL) {
1460             usb_mtp_queue_result(s, RES_INVALID_OBJECT_PROP_CODE,
1461                                  c->trans, 0, 0, 0, 0);
1462             return;
1463         }
1464         break;
1465     case CMD_GET_OBJECT_PROP_VALUE:
1466         o = usb_mtp_object_lookup(s, c->argv[0]);
1467         if (o == NULL) {
1468             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1469                                  c->trans, 0, 0, 0, 0);
1470             return;
1471         }
1472         data_in = usb_mtp_get_object_prop_value(s, c, o);
1473         if (data_in == NULL) {
1474             usb_mtp_queue_result(s, RES_INVALID_OBJECT_PROP_CODE,
1475                                  c->trans, 0, 0, 0, 0);
1476             return;
1477         }
1478         break;
1479     default:
1480         trace_usb_mtp_op_unknown(s->dev.addr, c->code);
1481         usb_mtp_queue_result(s, RES_OPERATION_NOT_SUPPORTED,
1482                              c->trans, 0, 0, 0, 0);
1483         return;
1484     }
1485 
1486     /* return results on success */
1487     if (data_in) {
1488         assert(s->data_in == NULL);
1489         s->data_in = data_in;
1490     }
1491     usb_mtp_queue_result(s, RES_OK, c->trans, nres, res0, 0, 0);
1492 }
1493 
1494 /* ----------------------------------------------------------------------- */
1495 
1496 static void usb_mtp_handle_reset(USBDevice *dev)
1497 {
1498     MTPState *s = USB_MTP(dev);
1499 
1500     trace_usb_mtp_reset(s->dev.addr);
1501 
1502     usb_mtp_file_monitor_cleanup(s);
1503     usb_mtp_object_free(s, QTAILQ_FIRST(&s->objects));
1504     s->session = 0;
1505     usb_mtp_data_free(s->data_in);
1506     s->data_in = NULL;
1507     usb_mtp_data_free(s->data_out);
1508     s->data_out = NULL;
1509     g_free(s->result);
1510     s->result = NULL;
1511 }
1512 
1513 static void usb_mtp_handle_control(USBDevice *dev, USBPacket *p,
1514                                    int request, int value, int index,
1515                                    int length, uint8_t *data)
1516 {
1517     int ret;
1518     MTPState *s = USB_MTP(dev);
1519     uint16_t *event = (uint16_t *)data;
1520 
1521     switch (request) {
1522     case ClassInterfaceOutRequest | 0x64:
1523         if (*event == EVT_CANCEL_TRANSACTION) {
1524             g_free(s->result);
1525             s->result = NULL;
1526             usb_mtp_data_free(s->data_in);
1527             s->data_in = NULL;
1528             if (s->write_pending) {
1529                 g_free(s->dataset.filename);
1530                 s->write_pending = false;
1531                 s->dataset.size = 0;
1532             }
1533             usb_mtp_data_free(s->data_out);
1534             s->data_out = NULL;
1535         } else {
1536             p->status = USB_RET_STALL;
1537         }
1538         break;
1539     default:
1540         ret = usb_desc_handle_control(dev, p, request,
1541                                       value, index, length, data);
1542         if (ret >= 0) {
1543             return;
1544         }
1545     }
1546 
1547     trace_usb_mtp_stall(dev->addr, "unknown control request");
1548 }
1549 
1550 static void usb_mtp_cancel_packet(USBDevice *dev, USBPacket *p)
1551 {
1552     /* we don't use async packets, so this should never be called */
1553     fprintf(stderr, "%s\n", __func__);
1554 }
1555 
1556 static char *utf16_to_str(uint8_t len, uint8_t *str16)
1557 {
1558     wchar_t *wstr = g_new0(wchar_t, len + 1);
1559     int count, dlen;
1560     char *dest;
1561 
1562     for (count = 0; count < len; count++) {
1563         /* FIXME: not working for surrogate pairs */
1564         wstr[count] = lduw_le_p(str16 + (count * 2));
1565     }
1566     wstr[count] = 0;
1567 
1568     dlen = wcstombs(NULL, wstr, 0) + 1;
1569     dest = g_malloc(dlen);
1570     wcstombs(dest, wstr, dlen);
1571     g_free(wstr);
1572     return dest;
1573 }
1574 
1575 /* Wrapper around write, returns 0 on failure */
1576 static uint64_t write_retry(int fd, void *buf, uint64_t size, off_t offset)
1577 {
1578         uint64_t ret = 0;
1579 
1580         if (lseek(fd, offset, SEEK_SET) < 0) {
1581             goto done;
1582         }
1583 
1584         ret = qemu_write_full(fd, buf, size);
1585 
1586 done:
1587         return ret;
1588 }
1589 
1590 static int usb_mtp_update_object(MTPObject *parent, char *name)
1591 {
1592     int ret = 0;
1593 
1594     MTPObject *o =
1595         usb_mtp_object_lookup_name(parent, name, strlen(name));
1596 
1597     if (o) {
1598         ret = lstat(o->path, &o->stat);
1599     }
1600 
1601     return ret;
1602 }
1603 
1604 static void usb_mtp_write_data(MTPState *s, uint32_t handle)
1605 {
1606     MTPData *d = s->data_out;
1607     MTPObject *parent =
1608         usb_mtp_object_lookup(s, s->dataset.parent_handle);
1609     char *path = NULL;
1610     uint64_t rc;
1611     mode_t mask = 0644;
1612     int ret = 0;
1613 
1614     assert(d != NULL);
1615 
1616     switch (d->write_status) {
1617     case WRITE_START:
1618         if (!parent || !s->write_pending) {
1619             usb_mtp_queue_result(s, RES_INVALID_OBJECTINFO, d->trans,
1620                 0, 0, 0, 0);
1621             return;
1622         }
1623 
1624         if (s->dataset.filename) {
1625             path = g_strdup_printf("%s/%s", parent->path, s->dataset.filename);
1626             if (s->dataset.format == FMT_ASSOCIATION) {
1627                 ret = mkdir(path, mask);
1628                 if (!ret) {
1629                     usb_mtp_queue_result(s, RES_OK, d->trans, 3,
1630                                          QEMU_STORAGE_ID,
1631                                          s->dataset.parent_handle,
1632                                          handle);
1633                     goto close;
1634                 }
1635                 goto done;
1636             }
1637 
1638             d->fd = open(path, O_CREAT | O_WRONLY |
1639                          O_CLOEXEC | O_NOFOLLOW, mask);
1640             if (d->fd == -1) {
1641                 ret = 1;
1642                 goto done;
1643             }
1644 
1645             /* Return success if initiator sent 0 sized data */
1646             if (!s->dataset.size) {
1647                 goto done;
1648             }
1649             if (d->length != MTP_WRITE_BUF_SZ && !d->pending) {
1650                 d->write_status = WRITE_END;
1651             }
1652         }
1653         /* fall through */
1654     case WRITE_CONTINUE:
1655     case WRITE_END:
1656         rc = write_retry(d->fd, d->data, d->data_offset,
1657                          d->offset - d->data_offset);
1658         if (rc != d->data_offset) {
1659             ret = 1;
1660             goto done;
1661         }
1662         if (d->write_status != WRITE_END) {
1663             g_free(path);
1664             return;
1665         } else {
1666             /*
1667              * Return an incomplete transfer if file size doesn't match
1668              * for < 4G file or if lstat fails which will result in an incorrect
1669              * file size
1670              */
1671             if ((s->dataset.size != 0xFFFFFFFF &&
1672                  d->offset != s->dataset.size) ||
1673                 usb_mtp_update_object(parent, s->dataset.filename)) {
1674                 usb_mtp_queue_result(s, RES_INCOMPLETE_TRANSFER, d->trans,
1675                                      0, 0, 0, 0);
1676                 goto close;
1677             }
1678         }
1679     }
1680 
1681 done:
1682     if (ret) {
1683         usb_mtp_queue_result(s, RES_STORE_FULL, d->trans,
1684                              0, 0, 0, 0);
1685     } else {
1686         usb_mtp_queue_result(s, RES_OK, d->trans,
1687                              0, 0, 0, 0);
1688     }
1689 close:
1690     /*
1691      * The write dataset is kept around and freed only
1692      * on success or if another write request comes in
1693      */
1694     if (d->fd != -1) {
1695         close(d->fd);
1696         d->fd = -1;
1697     }
1698     g_free(s->dataset.filename);
1699     s->dataset.size = 0;
1700     g_free(path);
1701     s->write_pending = false;
1702 }
1703 
1704 static void usb_mtp_write_metadata(MTPState *s, uint64_t dlen)
1705 {
1706     MTPData *d = s->data_out;
1707     ObjectInfo *dataset = (ObjectInfo *)d->data;
1708     char *filename;
1709     MTPObject *o;
1710     MTPObject *p = usb_mtp_object_lookup(s, s->dataset.parent_handle);
1711     uint32_t next_handle = s->next_handle;
1712     size_t filename_chars = dlen - offsetof(ObjectInfo, filename);
1713 
1714     /*
1715      * filename is utf-16. We're intentionally doing
1716      * integer division to truncate if malicious guest
1717      * sent an odd number of bytes.
1718      */
1719     filename_chars /= 2;
1720 
1721     assert(!s->write_pending);
1722     assert(p != NULL);
1723 
1724     filename = utf16_to_str(MIN(dataset->length, filename_chars),
1725                             dataset->filename);
1726 
1727     if (strchr(filename, '/')) {
1728         usb_mtp_queue_result(s, RES_PARAMETER_NOT_SUPPORTED, d->trans,
1729                              0, 0, 0, 0);
1730         g_free(filename);
1731         return;
1732     }
1733 
1734     o = usb_mtp_object_lookup_name(p, filename, -1);
1735     if (o != NULL) {
1736         next_handle = o->handle;
1737     }
1738 
1739     s->dataset.filename = filename;
1740     s->dataset.format = dataset->format;
1741     s->dataset.size = dataset->size;
1742     s->write_pending = true;
1743 
1744     if (s->dataset.format == FMT_ASSOCIATION) {
1745         usb_mtp_write_data(s, next_handle);
1746     } else {
1747         usb_mtp_queue_result(s, RES_OK, d->trans, 3, QEMU_STORAGE_ID,
1748                              s->dataset.parent_handle, next_handle);
1749     }
1750 }
1751 
1752 static void usb_mtp_get_data(MTPState *s, mtp_container *container,
1753                              USBPacket *p)
1754 {
1755     MTPData *d = s->data_out;
1756     uint64_t dlen;
1757     uint32_t data_len = p->iov.size;
1758     uint64_t total_len;
1759 
1760     if (!d) {
1761             usb_mtp_queue_result(s, RES_INVALID_OBJECTINFO, 0,
1762                                  0, 0, 0, 0);
1763             return;
1764     }
1765     if (d->first) {
1766         /* Total length of incoming data */
1767         total_len = cpu_to_le32(container->length) - sizeof(mtp_container);
1768         /* Length of data in this packet */
1769         data_len -= sizeof(mtp_container);
1770         if (total_len < MTP_WRITE_BUF_SZ) {
1771                 usb_mtp_realloc(d, total_len);
1772                 d->length += total_len;
1773         } else {
1774                 usb_mtp_realloc(d, MTP_WRITE_BUF_SZ - sizeof(mtp_container));
1775                 d->length += MTP_WRITE_BUF_SZ - sizeof(mtp_container);
1776         }
1777         d->offset = 0;
1778         d->first = false;
1779         d->pending = false;
1780         d->data_offset = 0;
1781         d->write_status = WRITE_START;
1782     }
1783 
1784     if (d->pending) {
1785         memset(d->data, 0, d->length);
1786         if (d->length != MTP_WRITE_BUF_SZ) {
1787             usb_mtp_realloc(d, MTP_WRITE_BUF_SZ - d->length);
1788             d->length += (MTP_WRITE_BUF_SZ - d->length);
1789         }
1790         d->pending = false;
1791         d->write_status = WRITE_CONTINUE;
1792         d->data_offset = 0;
1793     }
1794 
1795     if (d->length - d->data_offset > data_len) {
1796         dlen = data_len;
1797     } else {
1798         dlen = d->length - d->data_offset;
1799     }
1800 
1801     switch (d->code) {
1802     case CMD_SEND_OBJECT_INFO:
1803         usb_packet_copy(p, d->data + d->data_offset, dlen);
1804         d->offset += dlen;
1805         d->data_offset += dlen;
1806         if (d->data_offset == d->length) {
1807             /* The operation might have already failed */
1808             if (!s->result) {
1809                 usb_mtp_write_metadata(s, dlen);
1810             }
1811             usb_mtp_data_free(s->data_out);
1812             s->data_out = NULL;
1813             return;
1814         }
1815         break;
1816     case CMD_SEND_OBJECT:
1817         usb_packet_copy(p, d->data + d->data_offset, dlen);
1818         d->offset += dlen;
1819         d->data_offset += dlen;
1820         if ((p->iov.size % 64) || !p->iov.size) {
1821             assert((s->dataset.size == 0xFFFFFFFF) ||
1822                    (s->dataset.size == d->offset));
1823 
1824             if (d->length == MTP_WRITE_BUF_SZ) {
1825                 d->write_status = WRITE_END;
1826             } else {
1827                 d->write_status = WRITE_START;
1828             }
1829             usb_mtp_write_data(s, 0);
1830             usb_mtp_data_free(s->data_out);
1831             s->data_out = NULL;
1832             return;
1833         }
1834         if (d->data_offset == d->length) {
1835             d->pending = true;
1836             usb_mtp_write_data(s, 0);
1837         }
1838         break;
1839     default:
1840         p->status = USB_RET_STALL;
1841         return;
1842     }
1843 }
1844 
1845 static void usb_mtp_handle_data(USBDevice *dev, USBPacket *p)
1846 {
1847     MTPState *s = USB_MTP(dev);
1848     MTPControl cmd;
1849     mtp_container container;
1850     uint32_t params[5];
1851     uint16_t container_type;
1852     int i, rc;
1853 
1854     switch (p->ep->nr) {
1855     case EP_DATA_IN:
1856         if (s->data_out != NULL) {
1857             /* guest bug */
1858             trace_usb_mtp_stall(s->dev.addr, "awaiting data-out");
1859             p->status = USB_RET_STALL;
1860             return;
1861         }
1862         if (p->iov.size < sizeof(container)) {
1863             trace_usb_mtp_stall(s->dev.addr, "packet too small");
1864             p->status = USB_RET_STALL;
1865             return;
1866         }
1867         if (s->data_in !=  NULL) {
1868             MTPData *d = s->data_in;
1869             uint64_t dlen = d->length - d->offset;
1870             if (d->first) {
1871                 trace_usb_mtp_data_in(s->dev.addr, d->trans, d->length);
1872                 if (d->length + sizeof(container) > 0xFFFFFFFF) {
1873                     container.length = cpu_to_le32(0xFFFFFFFF);
1874                 } else {
1875                     container.length =
1876                         cpu_to_le32(d->length + sizeof(container));
1877                 }
1878                 container.type   = cpu_to_le16(TYPE_DATA);
1879                 container.code   = cpu_to_le16(d->code);
1880                 container.trans  = cpu_to_le32(d->trans);
1881                 usb_packet_copy(p, &container, sizeof(container));
1882                 d->first = false;
1883                 if (dlen > p->iov.size - sizeof(container)) {
1884                     dlen = p->iov.size - sizeof(container);
1885                 }
1886             } else {
1887                 if (dlen > p->iov.size) {
1888                     dlen = p->iov.size;
1889                 }
1890             }
1891             if (d->fd == -1) {
1892                 usb_packet_copy(p, d->data + d->offset, dlen);
1893             } else {
1894                 if (d->alloc < p->iov.size) {
1895                     d->alloc = p->iov.size;
1896                     d->data = g_realloc(d->data, d->alloc);
1897                 }
1898                 rc = read(d->fd, d->data, dlen);
1899                 if (rc != dlen) {
1900                     memset(d->data, 0, dlen);
1901                     s->result->code = RES_INCOMPLETE_TRANSFER;
1902                 }
1903                 usb_packet_copy(p, d->data, dlen);
1904             }
1905             d->offset += dlen;
1906             if (d->offset == d->length) {
1907                 usb_mtp_data_free(s->data_in);
1908                 s->data_in = NULL;
1909             }
1910         } else if (s->result != NULL) {
1911             MTPControl *r = s->result;
1912             int length = sizeof(container) + r->argc * sizeof(uint32_t);
1913             if (r->code == RES_OK) {
1914                 trace_usb_mtp_success(s->dev.addr, r->trans,
1915                                       (r->argc > 0) ? r->argv[0] : 0,
1916                                       (r->argc > 1) ? r->argv[1] : 0);
1917             } else {
1918                 trace_usb_mtp_error(s->dev.addr, r->code, r->trans,
1919                                     (r->argc > 0) ? r->argv[0] : 0,
1920                                     (r->argc > 1) ? r->argv[1] : 0);
1921             }
1922             container.length = cpu_to_le32(length);
1923             container.type   = cpu_to_le16(TYPE_RESPONSE);
1924             container.code   = cpu_to_le16(r->code);
1925             container.trans  = cpu_to_le32(r->trans);
1926             for (i = 0; i < r->argc; i++) {
1927                 params[i] = cpu_to_le32(r->argv[i]);
1928             }
1929             usb_packet_copy(p, &container, sizeof(container));
1930             usb_packet_copy(p, &params, length - sizeof(container));
1931             g_free(s->result);
1932             s->result = NULL;
1933         }
1934         break;
1935     case EP_DATA_OUT:
1936         if (p->iov.size < sizeof(container)) {
1937             trace_usb_mtp_stall(s->dev.addr, "packet too small");
1938             p->status = USB_RET_STALL;
1939             return;
1940         }
1941         if ((s->data_out != NULL) && !s->data_out->first) {
1942             container_type = TYPE_DATA;
1943         } else {
1944             usb_packet_copy(p, &container, sizeof(container));
1945             container_type = le16_to_cpu(container.type);
1946         }
1947         switch (container_type) {
1948         case TYPE_COMMAND:
1949             if (s->data_in || s->data_out || s->result) {
1950                 trace_usb_mtp_stall(s->dev.addr, "transaction inflight");
1951                 p->status = USB_RET_STALL;
1952                 return;
1953             }
1954             cmd.code = le16_to_cpu(container.code);
1955             cmd.argc = (le32_to_cpu(container.length) - sizeof(container))
1956                 / sizeof(uint32_t);
1957             cmd.trans = le32_to_cpu(container.trans);
1958             if (cmd.argc > ARRAY_SIZE(cmd.argv)) {
1959                 cmd.argc = ARRAY_SIZE(cmd.argv);
1960             }
1961             if (p->iov.size < sizeof(container) + cmd.argc * sizeof(uint32_t)) {
1962                 trace_usb_mtp_stall(s->dev.addr, "packet too small");
1963                 p->status = USB_RET_STALL;
1964                 return;
1965             }
1966             usb_packet_copy(p, &params, cmd.argc * sizeof(uint32_t));
1967             for (i = 0; i < cmd.argc; i++) {
1968                 cmd.argv[i] = le32_to_cpu(params[i]);
1969             }
1970             trace_usb_mtp_command(s->dev.addr, cmd.code, cmd.trans,
1971                                   (cmd.argc > 0) ? cmd.argv[0] : 0,
1972                                   (cmd.argc > 1) ? cmd.argv[1] : 0,
1973                                   (cmd.argc > 2) ? cmd.argv[2] : 0,
1974                                   (cmd.argc > 3) ? cmd.argv[3] : 0,
1975                                   (cmd.argc > 4) ? cmd.argv[4] : 0);
1976             usb_mtp_command(s, &cmd);
1977             break;
1978         case TYPE_DATA:
1979             /* One of the previous transfers has already errored but the
1980              * responder is still sending data associated with it
1981              */
1982             if (s->result != NULL) {
1983                 return;
1984             }
1985             usb_mtp_get_data(s, &container, p);
1986             break;
1987         default:
1988             /* not needed as long as the mtp device is read-only */
1989             p->status = USB_RET_STALL;
1990             return;
1991         }
1992         break;
1993     case EP_EVENT:
1994         if (!QTAILQ_EMPTY(&s->events)) {
1995             struct MTPMonEntry *e = QTAILQ_LAST(&s->events);
1996             uint32_t handle;
1997             int len = sizeof(container) + sizeof(uint32_t);
1998 
1999             if (p->iov.size < len) {
2000                 trace_usb_mtp_stall(s->dev.addr,
2001                                     "packet too small to send event");
2002                 p->status = USB_RET_STALL;
2003                 return;
2004             }
2005 
2006             QTAILQ_REMOVE(&s->events, e, next);
2007             container.length = cpu_to_le32(len);
2008             container.type = cpu_to_le32(TYPE_EVENT);
2009             container.code = cpu_to_le16(e->event);
2010             container.trans = 0; /* no trans specific events */
2011             handle = cpu_to_le32(e->handle);
2012             usb_packet_copy(p, &container, sizeof(container));
2013             usb_packet_copy(p, &handle, sizeof(uint32_t));
2014             g_free(e);
2015             return;
2016         }
2017         p->status = USB_RET_NAK;
2018         return;
2019     default:
2020         trace_usb_mtp_stall(s->dev.addr, "invalid endpoint");
2021         p->status = USB_RET_STALL;
2022         return;
2023     }
2024 
2025     if (p->actual_length == 0) {
2026         trace_usb_mtp_nak(s->dev.addr, p->ep->nr);
2027         p->status = USB_RET_NAK;
2028         return;
2029     } else {
2030         trace_usb_mtp_xfer(s->dev.addr, p->ep->nr, p->actual_length,
2031                            p->iov.size);
2032         return;
2033     }
2034 }
2035 
2036 static void usb_mtp_realize(USBDevice *dev, Error **errp)
2037 {
2038     MTPState *s = USB_MTP(dev);
2039 
2040     usb_desc_create_serial(dev);
2041     usb_desc_init(dev);
2042     QTAILQ_INIT(&s->objects);
2043     if (s->desc == NULL) {
2044         if (s->root == NULL) {
2045             error_setg(errp, "usb-mtp: rootdir property must be configured");
2046             return;
2047         }
2048         s->desc = strrchr(s->root, '/');
2049         if (s->desc && s->desc[0]) {
2050             s->desc = g_strdup(s->desc + 1);
2051         } else {
2052             s->desc = g_strdup("none");
2053         }
2054     }
2055     /* Mark store as RW */
2056     if (!s->readonly) {
2057         s->flags |= (1 << MTP_FLAG_WRITABLE);
2058     }
2059 
2060 }
2061 
2062 static const VMStateDescription vmstate_usb_mtp = {
2063     .name = "usb-mtp",
2064     .unmigratable = 1,
2065     .version_id = 1,
2066     .minimum_version_id = 1,
2067     .fields = (VMStateField[]) {
2068         VMSTATE_USB_DEVICE(dev, MTPState),
2069         VMSTATE_END_OF_LIST()
2070     }
2071 };
2072 
2073 static Property mtp_properties[] = {
2074     DEFINE_PROP_STRING("rootdir", MTPState, root),
2075     DEFINE_PROP_STRING("desc", MTPState, desc),
2076     DEFINE_PROP_BOOL("readonly", MTPState, readonly, true),
2077     DEFINE_PROP_END_OF_LIST(),
2078 };
2079 
2080 static void usb_mtp_class_initfn(ObjectClass *klass, void *data)
2081 {
2082     DeviceClass *dc = DEVICE_CLASS(klass);
2083     USBDeviceClass *uc = USB_DEVICE_CLASS(klass);
2084 
2085     uc->realize        = usb_mtp_realize;
2086     uc->product_desc   = "QEMU USB MTP";
2087     uc->usb_desc       = &desc;
2088     uc->cancel_packet  = usb_mtp_cancel_packet;
2089     uc->handle_attach  = usb_desc_attach;
2090     uc->handle_reset   = usb_mtp_handle_reset;
2091     uc->handle_control = usb_mtp_handle_control;
2092     uc->handle_data    = usb_mtp_handle_data;
2093     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
2094     dc->desc = "USB Media Transfer Protocol device";
2095     dc->fw_name = "mtp";
2096     dc->vmsd = &vmstate_usb_mtp;
2097     dc->props = mtp_properties;
2098 }
2099 
2100 static TypeInfo mtp_info = {
2101     .name          = TYPE_USB_MTP,
2102     .parent        = TYPE_USB_DEVICE,
2103     .instance_size = sizeof(MTPState),
2104     .class_init    = usb_mtp_class_initfn,
2105 };
2106 
2107 static void usb_mtp_register_types(void)
2108 {
2109     type_register_static(&mtp_info);
2110 }
2111 
2112 type_init(usb_mtp_register_types)
2113