xref: /openbmc/qemu/hw/usb/dev-mtp.c (revision 278f064e)
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 
35 enum 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 */
43 enum mtp_write_status {
44     WRITE_START    = 1,
45     WRITE_CONTINUE = 2,
46     WRITE_END      = 3,
47 };
48 
49 enum 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 
110 enum 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 
118 typedef 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 
127 typedef struct MTPState MTPState;
128 typedef struct MTPControl MTPControl;
129 typedef struct MTPData MTPData;
130 typedef struct MTPObject MTPObject;
131 
132 enum {
133     EP_DATA_IN = 1,
134     EP_DATA_OUT,
135     EP_EVENT,
136 };
137 
138 typedef struct MTPMonEntry MTPMonEntry;
139 
140 struct MTPMonEntry {
141     uint32_t event;
142     uint32_t handle;
143 
144     QTAILQ_ENTRY(MTPMonEntry) next;
145 };
146 
147 struct MTPControl {
148     uint16_t     code;
149     uint32_t     trans;
150     int          argc;
151     uint32_t     argv[5];
152 };
153 
154 struct 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 
170 struct 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 
186 struct 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  */
216 typedef 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"
241 OBJECT_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 
255 enum {
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 
265 static 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 
275 static 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 
300 static 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 
317 static 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 
342 static 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 
359 static const USBDescMSOS desc_msos = {
360     .CompatibleID = "MTP",
361     .SelectiveSuspendEnabled = true,
362 };
363 
364 static 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 
381 static 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 
420 ignore:
421     g_free(o->name);
422     g_free(o->path);
423     g_free(o);
424     return NULL;
425 }
426 
427 static 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 
456 static 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 
468 static 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 
487 static 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 
505 static 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 
518 static 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 
595 static 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 
609 static 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 
653 static 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 
664 static 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 
676 static 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 
685 static 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 
691 static 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 
698 static 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 
707 static 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 
720 static 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 
731 static 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 
742 static 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 
757 static 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 
773 static 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 
782 static 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 
807 static 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 
855 static 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 
869 static 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 
903 static 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 
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_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 
1495 static 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 
1512 static 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 
1549 static 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 
1555 static 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 */
1575 static 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 
1585 done:
1586         return ret;
1587 }
1588 
1589 static 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 
1603 static 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 
1680 done:
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     }
1688 close:
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 
1703 static 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 
1751 static 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 
1844 static 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 
2035 static 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 
2071 static 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 
2082 static 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 
2089 static 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 
2109 static 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 
2116 static void usb_mtp_register_types(void)
2117 {
2118     type_register_static(&mtp_info);
2119 }
2120 
2121 type_init(usb_mtp_register_types)
2122