xref: /openbmc/qemu/hw/usb/dev-mtp.c (revision 65a117da)
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 
32 /* ----------------------------------------------------------------------- */
33 
34 enum mtp_container_type {
35     TYPE_COMMAND  = 1,
36     TYPE_DATA     = 2,
37     TYPE_RESPONSE = 3,
38     TYPE_EVENT    = 4,
39 };
40 
41 /* MTP write stage, for internal use only */
42 enum mtp_write_status {
43     WRITE_START    = 1,
44     WRITE_CONTINUE = 2,
45     WRITE_END      = 3,
46 };
47 
48 enum mtp_code {
49     /* command codes */
50     CMD_GET_DEVICE_INFO            = 0x1001,
51     CMD_OPEN_SESSION               = 0x1002,
52     CMD_CLOSE_SESSION              = 0x1003,
53     CMD_GET_STORAGE_IDS            = 0x1004,
54     CMD_GET_STORAGE_INFO           = 0x1005,
55     CMD_GET_NUM_OBJECTS            = 0x1006,
56     CMD_GET_OBJECT_HANDLES         = 0x1007,
57     CMD_GET_OBJECT_INFO            = 0x1008,
58     CMD_GET_OBJECT                 = 0x1009,
59     CMD_DELETE_OBJECT              = 0x100b,
60     CMD_SEND_OBJECT_INFO           = 0x100c,
61     CMD_SEND_OBJECT                = 0x100d,
62     CMD_GET_PARTIAL_OBJECT         = 0x101b,
63     CMD_GET_OBJECT_PROPS_SUPPORTED = 0x9801,
64     CMD_GET_OBJECT_PROP_DESC       = 0x9802,
65     CMD_GET_OBJECT_PROP_VALUE      = 0x9803,
66 
67     /* response codes */
68     RES_OK                         = 0x2001,
69     RES_GENERAL_ERROR              = 0x2002,
70     RES_SESSION_NOT_OPEN           = 0x2003,
71     RES_INVALID_TRANSACTION_ID     = 0x2004,
72     RES_OPERATION_NOT_SUPPORTED    = 0x2005,
73     RES_PARAMETER_NOT_SUPPORTED    = 0x2006,
74     RES_INCOMPLETE_TRANSFER        = 0x2007,
75     RES_INVALID_STORAGE_ID         = 0x2008,
76     RES_INVALID_OBJECT_HANDLE      = 0x2009,
77     RES_INVALID_OBJECT_FORMAT_CODE = 0x200b,
78     RES_STORE_FULL                 = 0x200c,
79     RES_STORE_READ_ONLY            = 0x200e,
80     RES_PARTIAL_DELETE             = 0x2012,
81     RES_STORE_NOT_AVAILABLE        = 0x2013,
82     RES_SPEC_BY_FORMAT_UNSUPPORTED = 0x2014,
83     RES_INVALID_OBJECTINFO         = 0x2015,
84     RES_DESTINATION_UNSUPPORTED    = 0x2020,
85     RES_INVALID_PARENT_OBJECT      = 0x201a,
86     RES_INVALID_PARAMETER          = 0x201d,
87     RES_SESSION_ALREADY_OPEN       = 0x201e,
88     RES_INVALID_OBJECT_PROP_CODE   = 0xA801,
89 
90     /* format codes */
91     FMT_UNDEFINED_OBJECT           = 0x3000,
92     FMT_ASSOCIATION                = 0x3001,
93 
94     /* event codes */
95     EVT_CANCEL_TRANSACTION         = 0x4001,
96     EVT_OBJ_ADDED                  = 0x4002,
97     EVT_OBJ_REMOVED                = 0x4003,
98     EVT_OBJ_INFO_CHANGED           = 0x4007,
99 
100     /* object properties */
101     PROP_STORAGE_ID                = 0xDC01,
102     PROP_OBJECT_FORMAT             = 0xDC02,
103     PROP_OBJECT_COMPRESSED_SIZE    = 0xDC04,
104     PROP_PARENT_OBJECT             = 0xDC0B,
105     PROP_PERSISTENT_UNIQUE_OBJECT_IDENTIFIER = 0xDC41,
106     PROP_NAME                      = 0xDC44,
107 };
108 
109 enum mtp_data_type {
110     DATA_TYPE_UINT16  = 0x0004,
111     DATA_TYPE_UINT32  = 0x0006,
112     DATA_TYPE_UINT64  = 0x0008,
113     DATA_TYPE_UINT128 = 0x000a,
114     DATA_TYPE_STRING  = 0xffff,
115 };
116 
117 typedef struct {
118     uint32_t length;
119     uint16_t type;
120     uint16_t code;
121     uint32_t trans;
122 } QEMU_PACKED mtp_container;
123 
124 /* ----------------------------------------------------------------------- */
125 
126 typedef struct MTPState MTPState;
127 typedef struct MTPControl MTPControl;
128 typedef struct MTPData MTPData;
129 typedef struct MTPObject MTPObject;
130 
131 enum {
132     EP_DATA_IN = 1,
133     EP_DATA_OUT,
134     EP_EVENT,
135 };
136 
137 typedef struct MTPMonEntry MTPMonEntry;
138 
139 struct MTPMonEntry {
140     uint32_t event;
141     uint32_t handle;
142 
143     QTAILQ_ENTRY(MTPMonEntry) next;
144 };
145 
146 struct MTPControl {
147     uint16_t     code;
148     uint32_t     trans;
149     int          argc;
150     uint32_t     argv[5];
151 };
152 
153 struct MTPData {
154     uint16_t     code;
155     uint32_t     trans;
156     uint64_t     offset;
157     uint64_t     length;
158     uint64_t     alloc;
159     uint8_t      *data;
160     bool         first;
161     /* Used for >4G file sizes */
162     bool         pending;
163     int          fd;
164     uint8_t      write_status;
165     /* Internal pointer per every MTP_WRITE_BUF_SZ */
166     uint64_t     data_offset;
167 };
168 
169 struct MTPObject {
170     uint32_t     handle;
171     uint16_t     format;
172     char         *name;
173     char         *path;
174     struct stat  stat;
175     /* file monitor watch id */
176     int64_t      watchid;
177     MTPObject    *parent;
178     uint32_t     nchildren;
179     QLIST_HEAD(, MTPObject) children;
180     QLIST_ENTRY(MTPObject) list;
181     bool         have_children;
182     QTAILQ_ENTRY(MTPObject) next;
183 };
184 
185 struct MTPState {
186     USBDevice    dev;
187     char         *root;
188     char         *desc;
189     uint32_t     flags;
190 
191     MTPData      *data_in;
192     MTPData      *data_out;
193     MTPControl   *result;
194     uint32_t     session;
195     uint32_t     next_handle;
196     bool         readonly;
197 
198     QTAILQ_HEAD(, MTPObject) objects;
199     QFileMonitor *file_monitor;
200     QTAILQ_HEAD(, MTPMonEntry) events;
201     /* Responder is expecting a write operation */
202     bool write_pending;
203     struct {
204         uint32_t parent_handle;
205         uint16_t format;
206         uint32_t size;
207         char *filename;
208     } dataset;
209 };
210 
211 /*
212  * ObjectInfo dataset received from initiator
213  * Fields we don't care about are ignored
214  */
215 typedef struct {
216     uint32_t storage_id; /*unused*/
217     uint16_t format;
218     uint16_t protection_status; /*unused*/
219     uint32_t size;
220     uint16_t thumb_format; /*unused*/
221     uint32_t thumb_comp_sz; /*unused*/
222     uint32_t thumb_pix_width; /*unused*/
223     uint32_t thumb_pix_height; /*unused*/
224     uint32_t image_pix_width; /*unused*/
225     uint32_t image_pix_height; /*unused*/
226     uint32_t image_bit_depth; /*unused*/
227     uint32_t parent; /*unused*/
228     uint16_t assoc_type;
229     uint32_t assoc_desc;
230     uint32_t seq_no; /*unused*/
231     uint8_t length; /*part of filename field*/
232     uint8_t filename[0]; /* UTF-16 encoded */
233     char date_created[0]; /*unused*/
234     char date_modified[0]; /*unused*/
235     char keywords[0]; /*unused*/
236     /* string and other data follows */
237 } QEMU_PACKED ObjectInfo;
238 
239 #define TYPE_USB_MTP "usb-mtp"
240 #define USB_MTP(obj) OBJECT_CHECK(MTPState, (obj), TYPE_USB_MTP)
241 
242 #define QEMU_STORAGE_ID 0x00010001
243 
244 #define MTP_FLAG_WRITABLE 0
245 
246 #define FLAG_SET(_mtp, _flag)  ((_mtp)->flags & (1 << (_flag)))
247 
248 /* ----------------------------------------------------------------------- */
249 
250 #define MTP_MANUFACTURER  "QEMU"
251 #define MTP_PRODUCT       "QEMU filesharing"
252 #define MTP_WRITE_BUF_SZ  (512 * KiB)
253 
254 enum {
255     STR_MANUFACTURER = 1,
256     STR_PRODUCT,
257     STR_SERIALNUMBER,
258     STR_MTP,
259     STR_CONFIG_FULL,
260     STR_CONFIG_HIGH,
261     STR_CONFIG_SUPER,
262 };
263 
264 static const USBDescStrings desc_strings = {
265     [STR_MANUFACTURER] = MTP_MANUFACTURER,
266     [STR_PRODUCT]      = MTP_PRODUCT,
267     [STR_SERIALNUMBER] = "34617",
268     [STR_MTP]          = "MTP",
269     [STR_CONFIG_FULL]  = "Full speed config (usb 1.1)",
270     [STR_CONFIG_HIGH]  = "High speed config (usb 2.0)",
271     [STR_CONFIG_SUPER] = "Super speed config (usb 3.0)",
272 };
273 
274 static const USBDescIface desc_iface_full = {
275     .bInterfaceNumber              = 0,
276     .bNumEndpoints                 = 3,
277     .bInterfaceClass               = USB_CLASS_STILL_IMAGE,
278     .bInterfaceSubClass            = 0x01,
279     .bInterfaceProtocol            = 0x01,
280     .iInterface                    = STR_MTP,
281     .eps = (USBDescEndpoint[]) {
282         {
283             .bEndpointAddress      = USB_DIR_IN | EP_DATA_IN,
284             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
285             .wMaxPacketSize        = 64,
286         },{
287             .bEndpointAddress      = USB_DIR_OUT | EP_DATA_OUT,
288             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
289             .wMaxPacketSize        = 64,
290         },{
291             .bEndpointAddress      = USB_DIR_IN | EP_EVENT,
292             .bmAttributes          = USB_ENDPOINT_XFER_INT,
293             .wMaxPacketSize        = 64,
294             .bInterval             = 0x0a,
295         },
296     }
297 };
298 
299 static const USBDescDevice desc_device_full = {
300     .bcdUSB                        = 0x0200,
301     .bMaxPacketSize0               = 8,
302     .bNumConfigurations            = 1,
303     .confs = (USBDescConfig[]) {
304         {
305             .bNumInterfaces        = 1,
306             .bConfigurationValue   = 1,
307             .iConfiguration        = STR_CONFIG_FULL,
308             .bmAttributes          = USB_CFG_ATT_ONE | USB_CFG_ATT_WAKEUP,
309             .bMaxPower             = 2,
310             .nif = 1,
311             .ifs = &desc_iface_full,
312         },
313     },
314 };
315 
316 static const USBDescIface desc_iface_high = {
317     .bInterfaceNumber              = 0,
318     .bNumEndpoints                 = 3,
319     .bInterfaceClass               = USB_CLASS_STILL_IMAGE,
320     .bInterfaceSubClass            = 0x01,
321     .bInterfaceProtocol            = 0x01,
322     .iInterface                    = STR_MTP,
323     .eps = (USBDescEndpoint[]) {
324         {
325             .bEndpointAddress      = USB_DIR_IN | EP_DATA_IN,
326             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
327             .wMaxPacketSize        = 512,
328         },{
329             .bEndpointAddress      = USB_DIR_OUT | EP_DATA_OUT,
330             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
331             .wMaxPacketSize        = 512,
332         },{
333             .bEndpointAddress      = USB_DIR_IN | EP_EVENT,
334             .bmAttributes          = USB_ENDPOINT_XFER_INT,
335             .wMaxPacketSize        = 64,
336             .bInterval             = 0x0a,
337         },
338     }
339 };
340 
341 static const USBDescDevice desc_device_high = {
342     .bcdUSB                        = 0x0200,
343     .bMaxPacketSize0               = 64,
344     .bNumConfigurations            = 1,
345     .confs = (USBDescConfig[]) {
346         {
347             .bNumInterfaces        = 1,
348             .bConfigurationValue   = 1,
349             .iConfiguration        = STR_CONFIG_HIGH,
350             .bmAttributes          = USB_CFG_ATT_ONE | USB_CFG_ATT_WAKEUP,
351             .bMaxPower             = 2,
352             .nif = 1,
353             .ifs = &desc_iface_high,
354         },
355     },
356 };
357 
358 static const USBDescMSOS desc_msos = {
359     .CompatibleID = "MTP",
360     .SelectiveSuspendEnabled = true,
361 };
362 
363 static const USBDesc desc = {
364     .id = {
365         .idVendor          = 0x46f4, /* CRC16() of "QEMU" */
366         .idProduct         = 0x0004,
367         .bcdDevice         = 0,
368         .iManufacturer     = STR_MANUFACTURER,
369         .iProduct          = STR_PRODUCT,
370         .iSerialNumber     = STR_SERIALNUMBER,
371     },
372     .full  = &desc_device_full,
373     .high  = &desc_device_high,
374     .str   = desc_strings,
375     .msos  = &desc_msos,
376 };
377 
378 /* ----------------------------------------------------------------------- */
379 
380 static MTPObject *usb_mtp_object_alloc(MTPState *s, uint32_t handle,
381                                        MTPObject *parent, const char *name)
382 {
383     MTPObject *o = g_new0(MTPObject, 1);
384 
385     if (name[0] == '.') {
386         goto ignore;
387     }
388 
389     o->watchid = -1;
390     o->handle = handle;
391     o->parent = parent;
392     o->name = g_strdup(name);
393     if (parent == NULL) {
394         o->path = g_strdup(name);
395     } else {
396         o->path = g_strdup_printf("%s/%s", parent->path, name);
397     }
398 
399     if (lstat(o->path, &o->stat) != 0) {
400         goto ignore;
401     }
402     if (S_ISREG(o->stat.st_mode)) {
403         o->format = FMT_UNDEFINED_OBJECT;
404     } else if (S_ISDIR(o->stat.st_mode)) {
405         o->format = FMT_ASSOCIATION;
406     } else {
407         goto ignore;
408     }
409 
410     if (access(o->path, R_OK) != 0) {
411         goto ignore;
412     }
413 
414     trace_usb_mtp_object_alloc(s->dev.addr, o->handle, o->path);
415 
416     QTAILQ_INSERT_TAIL(&s->objects, o, next);
417     return o;
418 
419 ignore:
420     g_free(o->name);
421     g_free(o->path);
422     g_free(o);
423     return NULL;
424 }
425 
426 static void usb_mtp_object_free(MTPState *s, MTPObject *o)
427 {
428     MTPObject *iter;
429 
430     if (!o) {
431         return;
432     }
433 
434     trace_usb_mtp_object_free(s->dev.addr, o->handle, o->path);
435 
436     if (o->watchid != -1 && s->file_monitor) {
437         qemu_file_monitor_remove_watch(s->file_monitor, o->path, o->watchid);
438     }
439 
440     QTAILQ_REMOVE(&s->objects, o, next);
441     if (o->parent) {
442         QLIST_REMOVE(o, list);
443         o->parent->nchildren--;
444     }
445 
446     while (!QLIST_EMPTY(&o->children)) {
447         iter = QLIST_FIRST(&o->children);
448         usb_mtp_object_free(s, iter);
449     }
450     g_free(o->name);
451     g_free(o->path);
452     g_free(o);
453 }
454 
455 static MTPObject *usb_mtp_object_lookup(MTPState *s, uint32_t handle)
456 {
457     MTPObject *o;
458 
459     QTAILQ_FOREACH(o, &s->objects, next) {
460         if (o->handle == handle) {
461             return o;
462         }
463     }
464     return NULL;
465 }
466 
467 static MTPObject *usb_mtp_add_child(MTPState *s, MTPObject *o,
468                                     const char *name)
469 {
470     MTPObject *child =
471         usb_mtp_object_alloc(s, s->next_handle++, o, name);
472 
473     if (child) {
474         trace_usb_mtp_add_child(s->dev.addr, child->handle, child->path);
475         QLIST_INSERT_HEAD(&o->children, child, list);
476         o->nchildren++;
477 
478         if (child->format == FMT_ASSOCIATION) {
479             QLIST_INIT(&child->children);
480         }
481     }
482 
483     return child;
484 }
485 
486 static MTPObject *usb_mtp_object_lookup_name(MTPObject *parent,
487                                              const char *name, int len)
488 {
489     MTPObject *iter;
490 
491     if (len == -1) {
492         len = strlen(name);
493     }
494 
495     QLIST_FOREACH(iter, &parent->children, list) {
496         if (strncmp(iter->name, name, len) == 0) {
497             return iter;
498         }
499     }
500 
501     return NULL;
502 }
503 
504 static MTPObject *usb_mtp_object_lookup_id(MTPState *s, int64_t id)
505 {
506     MTPObject *iter;
507 
508     QTAILQ_FOREACH(iter, &s->objects, next) {
509         if (iter->watchid == id) {
510             return iter;
511         }
512     }
513 
514     return NULL;
515 }
516 
517 static void file_monitor_event(int64_t id,
518                                QFileMonitorEvent ev,
519                                const char *name,
520                                void *opaque)
521 {
522     MTPState *s = opaque;
523     MTPObject *parent = usb_mtp_object_lookup_id(s, id);
524     MTPMonEntry *entry = NULL;
525     MTPObject *o;
526 
527     if (!parent) {
528         return;
529     }
530 
531     switch (ev) {
532     case QFILE_MONITOR_EVENT_CREATED:
533         if (usb_mtp_object_lookup_name(parent, name, -1)) {
534             /* Duplicate create event */
535             return;
536         }
537         entry = g_new0(MTPMonEntry, 1);
538         entry->handle = s->next_handle;
539         entry->event = EVT_OBJ_ADDED;
540         o = usb_mtp_add_child(s, parent, name);
541         if (!o) {
542             g_free(entry);
543             return;
544         }
545         trace_usb_mtp_file_monitor_event(s->dev.addr, name, "Obj Added");
546         break;
547 
548     case QFILE_MONITOR_EVENT_DELETED:
549         /*
550          * The kernel issues a IN_IGNORED event
551          * when a dir containing a watchpoint is
552          * deleted, so we don't have to delete the
553          * watchpoint
554          */
555         o = usb_mtp_object_lookup_name(parent, name, -1);
556         if (!o) {
557             return;
558         }
559         entry = g_new0(MTPMonEntry, 1);
560         entry->handle = o->handle;
561         entry->event = EVT_OBJ_REMOVED;
562         trace_usb_mtp_file_monitor_event(s->dev.addr, o->path, "Obj Deleted");
563         usb_mtp_object_free(s, o);
564         break;
565 
566     case QFILE_MONITOR_EVENT_MODIFIED:
567         o = usb_mtp_object_lookup_name(parent, name, -1);
568         if (!o) {
569             return;
570         }
571         entry = g_new0(MTPMonEntry, 1);
572         entry->handle = o->handle;
573         entry->event = EVT_OBJ_INFO_CHANGED;
574         trace_usb_mtp_file_monitor_event(s->dev.addr, o->path, "Obj Modified");
575         break;
576 
577     case QFILE_MONITOR_EVENT_IGNORED:
578         trace_usb_mtp_file_monitor_event(s->dev.addr, parent->path,
579                                     "Obj parent dir ignored");
580         break;
581 
582     case QFILE_MONITOR_EVENT_ATTRIBUTES:
583         break;
584 
585     default:
586         g_assert_not_reached();
587     }
588 
589     if (entry) {
590         QTAILQ_INSERT_HEAD(&s->events, entry, next);
591     }
592 }
593 
594 static void usb_mtp_file_monitor_cleanup(MTPState *s)
595 {
596     MTPMonEntry *e, *p;
597 
598     QTAILQ_FOREACH_SAFE(e, &s->events, next, p) {
599         QTAILQ_REMOVE(&s->events, e, next);
600         g_free(e);
601     }
602 
603     qemu_file_monitor_free(s->file_monitor);
604     s->file_monitor = NULL;
605 }
606 
607 
608 static void usb_mtp_object_readdir(MTPState *s, MTPObject *o)
609 {
610     struct dirent *entry;
611     DIR *dir;
612     int fd;
613     Error *err = NULL;
614 
615     if (o->have_children) {
616         return;
617     }
618     o->have_children = true;
619 
620     fd = open(o->path, O_DIRECTORY | O_CLOEXEC | O_NOFOLLOW);
621     if (fd < 0) {
622         return;
623     }
624     dir = fdopendir(fd);
625     if (!dir) {
626         close(fd);
627         return;
628     }
629 
630     if (s->file_monitor) {
631         int64_t id = qemu_file_monitor_add_watch(s->file_monitor, o->path, NULL,
632                                                  file_monitor_event, s, &err);
633         if (id == -1) {
634             error_reportf_err(err,
635                               "usb-mtp: failed to add watch for %s: ",
636                               o->path);
637             error_free(err);
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     char buf[16];
776     struct tm tm;
777 
778     gmtime_r(&time, &tm);
779     strftime(buf, sizeof(buf), "%Y%m%dT%H%M%S", &tm);
780     usb_mtp_add_str(data, buf);
781 }
782 
783 /* ----------------------------------------------------------------------- */
784 
785 static void usb_mtp_queue_result(MTPState *s, uint16_t code, uint32_t trans,
786                                  int argc, uint32_t arg0, uint32_t arg1,
787                                  uint32_t arg2)
788 {
789     MTPControl *c = g_new0(MTPControl, 1);
790 
791     c->code  = code;
792     c->trans = trans;
793     c->argc  = argc;
794     if (argc > 0) {
795         c->argv[0] = arg0;
796     }
797     if (argc > 1) {
798         c->argv[1] = arg1;
799     }
800     if (argc > 2) {
801         c->argv[2] = arg2;
802     }
803 
804     assert(s->result == NULL);
805     s->result = c;
806 }
807 
808 /* ----------------------------------------------------------------------- */
809 
810 static MTPData *usb_mtp_get_device_info(MTPState *s, MTPControl *c)
811 {
812     static const uint16_t ops[] = {
813         CMD_GET_DEVICE_INFO,
814         CMD_OPEN_SESSION,
815         CMD_CLOSE_SESSION,
816         CMD_GET_STORAGE_IDS,
817         CMD_GET_STORAGE_INFO,
818         CMD_GET_NUM_OBJECTS,
819         CMD_GET_OBJECT_HANDLES,
820         CMD_GET_OBJECT_INFO,
821         CMD_DELETE_OBJECT,
822         CMD_SEND_OBJECT_INFO,
823         CMD_SEND_OBJECT,
824         CMD_GET_OBJECT,
825         CMD_GET_PARTIAL_OBJECT,
826         CMD_GET_OBJECT_PROPS_SUPPORTED,
827         CMD_GET_OBJECT_PROP_DESC,
828         CMD_GET_OBJECT_PROP_VALUE,
829     };
830     static const uint16_t fmt[] = {
831         FMT_UNDEFINED_OBJECT,
832         FMT_ASSOCIATION,
833     };
834     MTPData *d = usb_mtp_data_alloc(c);
835 
836     trace_usb_mtp_op_get_device_info(s->dev.addr);
837 
838     usb_mtp_add_u16(d, 100);
839     usb_mtp_add_u32(d, 0x00000006);
840     usb_mtp_add_u16(d, 0x0064);
841     usb_mtp_add_wstr(d, L"");
842     usb_mtp_add_u16(d, 0x0000);
843 
844     usb_mtp_add_u16_array(d, ARRAY_SIZE(ops), ops);
845     usb_mtp_add_u16_array(d, 0, NULL);
846     usb_mtp_add_u16_array(d, 0, NULL);
847     usb_mtp_add_u16_array(d, 0, NULL);
848     usb_mtp_add_u16_array(d, ARRAY_SIZE(fmt), fmt);
849 
850     usb_mtp_add_wstr(d, L"" MTP_MANUFACTURER);
851     usb_mtp_add_wstr(d, L"" MTP_PRODUCT);
852     usb_mtp_add_wstr(d, L"0.1");
853     usb_mtp_add_wstr(d, L"0123456789abcdef0123456789abcdef");
854 
855     return d;
856 }
857 
858 static MTPData *usb_mtp_get_storage_ids(MTPState *s, MTPControl *c)
859 {
860     static const uint32_t ids[] = {
861         QEMU_STORAGE_ID,
862     };
863     MTPData *d = usb_mtp_data_alloc(c);
864 
865     trace_usb_mtp_op_get_storage_ids(s->dev.addr);
866 
867     usb_mtp_add_u32_array(d, ARRAY_SIZE(ids), ids);
868 
869     return d;
870 }
871 
872 static MTPData *usb_mtp_get_storage_info(MTPState *s, MTPControl *c)
873 {
874     MTPData *d = usb_mtp_data_alloc(c);
875     struct statvfs buf;
876     int rc;
877 
878     trace_usb_mtp_op_get_storage_info(s->dev.addr);
879 
880     if (FLAG_SET(s, MTP_FLAG_WRITABLE)) {
881         usb_mtp_add_u16(d, 0x0003);
882         usb_mtp_add_u16(d, 0x0002);
883         usb_mtp_add_u16(d, 0x0000);
884     } else {
885         usb_mtp_add_u16(d, 0x0001);
886         usb_mtp_add_u16(d, 0x0002);
887         usb_mtp_add_u16(d, 0x0001);
888     }
889 
890     rc = statvfs(s->root, &buf);
891     if (rc == 0) {
892         usb_mtp_add_u64(d, (uint64_t)buf.f_frsize * buf.f_blocks);
893         usb_mtp_add_u64(d, (uint64_t)buf.f_bavail * buf.f_blocks);
894         usb_mtp_add_u32(d, buf.f_ffree);
895     } else {
896         usb_mtp_add_u64(d, 0xffffffff);
897         usb_mtp_add_u64(d, 0xffffffff);
898         usb_mtp_add_u32(d, 0xffffffff);
899     }
900 
901     usb_mtp_add_str(d, s->desc);
902     usb_mtp_add_wstr(d, L"123456789abcdef");
903     return d;
904 }
905 
906 static MTPData *usb_mtp_get_object_handles(MTPState *s, MTPControl *c,
907                                            MTPObject *o)
908 {
909     MTPData *d = usb_mtp_data_alloc(c);
910     uint32_t i = 0, handles[o->nchildren];
911     MTPObject *iter;
912 
913     trace_usb_mtp_op_get_object_handles(s->dev.addr, o->handle, o->path);
914 
915     QLIST_FOREACH(iter, &o->children, list) {
916         handles[i++] = iter->handle;
917     }
918     assert(i == o->nchildren);
919     usb_mtp_add_u32_array(d, o->nchildren, handles);
920 
921     return d;
922 }
923 
924 static MTPData *usb_mtp_get_object_info(MTPState *s, MTPControl *c,
925                                         MTPObject *o)
926 {
927     MTPData *d = usb_mtp_data_alloc(c);
928 
929     trace_usb_mtp_op_get_object_info(s->dev.addr, o->handle, o->path);
930 
931     usb_mtp_add_u32(d, QEMU_STORAGE_ID);
932     usb_mtp_add_u16(d, o->format);
933     usb_mtp_add_u16(d, 0);
934 
935     if (o->stat.st_size > 0xFFFFFFFF) {
936         usb_mtp_add_u32(d, 0xFFFFFFFF);
937     } else {
938         usb_mtp_add_u32(d, o->stat.st_size);
939     }
940 
941     usb_mtp_add_u16(d, 0);
942     usb_mtp_add_u32(d, 0);
943     usb_mtp_add_u32(d, 0);
944     usb_mtp_add_u32(d, 0);
945     usb_mtp_add_u32(d, 0);
946     usb_mtp_add_u32(d, 0);
947     usb_mtp_add_u32(d, 0);
948 
949     if (o->parent) {
950         usb_mtp_add_u32(d, o->parent->handle);
951     } else {
952         usb_mtp_add_u32(d, 0);
953     }
954     if (o->format == FMT_ASSOCIATION) {
955         usb_mtp_add_u16(d, 0x0001);
956         usb_mtp_add_u32(d, 0x00000001);
957         usb_mtp_add_u32(d, 0);
958     } else {
959         usb_mtp_add_u16(d, 0);
960         usb_mtp_add_u32(d, 0);
961         usb_mtp_add_u32(d, 0);
962     }
963 
964     usb_mtp_add_str(d, o->name);
965     usb_mtp_add_time(d, o->stat.st_ctime);
966     usb_mtp_add_time(d, o->stat.st_mtime);
967     usb_mtp_add_wstr(d, L"");
968 
969     return d;
970 }
971 
972 static MTPData *usb_mtp_get_object(MTPState *s, MTPControl *c,
973                                    MTPObject *o)
974 {
975     MTPData *d = usb_mtp_data_alloc(c);
976 
977     trace_usb_mtp_op_get_object(s->dev.addr, o->handle, o->path);
978 
979     d->fd = open(o->path, O_RDONLY | O_CLOEXEC | O_NOFOLLOW);
980     if (d->fd == -1) {
981         usb_mtp_data_free(d);
982         return NULL;
983     }
984     d->length = o->stat.st_size;
985     d->alloc  = 512;
986     d->data   = g_malloc(d->alloc);
987     return d;
988 }
989 
990 static MTPData *usb_mtp_get_partial_object(MTPState *s, MTPControl *c,
991                                            MTPObject *o)
992 {
993     MTPData *d;
994     off_t offset;
995 
996     if (c->argc <= 2) {
997         return NULL;
998     }
999     trace_usb_mtp_op_get_partial_object(s->dev.addr, o->handle, o->path,
1000                                         c->argv[1], c->argv[2]);
1001 
1002     d = usb_mtp_data_alloc(c);
1003     d->fd = open(o->path, O_RDONLY | O_CLOEXEC | O_NOFOLLOW);
1004     if (d->fd == -1) {
1005         usb_mtp_data_free(d);
1006         return NULL;
1007     }
1008 
1009     offset = c->argv[1];
1010     if (offset > o->stat.st_size) {
1011         offset = o->stat.st_size;
1012     }
1013     if (lseek(d->fd, offset, SEEK_SET) < 0) {
1014         usb_mtp_data_free(d);
1015         return NULL;
1016     }
1017 
1018     d->length = c->argv[2];
1019     if (d->length > o->stat.st_size - offset) {
1020         d->length = o->stat.st_size - offset;
1021     }
1022 
1023     return d;
1024 }
1025 
1026 static MTPData *usb_mtp_get_object_props_supported(MTPState *s, MTPControl *c)
1027 {
1028     static const uint16_t props[] = {
1029         PROP_STORAGE_ID,
1030         PROP_OBJECT_FORMAT,
1031         PROP_OBJECT_COMPRESSED_SIZE,
1032         PROP_PARENT_OBJECT,
1033         PROP_PERSISTENT_UNIQUE_OBJECT_IDENTIFIER,
1034         PROP_NAME,
1035     };
1036     MTPData *d = usb_mtp_data_alloc(c);
1037     usb_mtp_add_u16_array(d, ARRAY_SIZE(props), props);
1038 
1039     return d;
1040 }
1041 
1042 static MTPData *usb_mtp_get_object_prop_desc(MTPState *s, MTPControl *c)
1043 {
1044     MTPData *d = usb_mtp_data_alloc(c);
1045     switch (c->argv[0]) {
1046     case PROP_STORAGE_ID:
1047         usb_mtp_add_u16(d, PROP_STORAGE_ID);
1048         usb_mtp_add_u16(d, DATA_TYPE_UINT32);
1049         usb_mtp_add_u8(d, 0x00);
1050         usb_mtp_add_u32(d, 0x00000000);
1051         usb_mtp_add_u32(d, 0x00000000);
1052         usb_mtp_add_u8(d, 0x00);
1053         break;
1054     case PROP_OBJECT_FORMAT:
1055         usb_mtp_add_u16(d, PROP_OBJECT_FORMAT);
1056         usb_mtp_add_u16(d, DATA_TYPE_UINT16);
1057         usb_mtp_add_u8(d, 0x00);
1058         usb_mtp_add_u16(d, 0x0000);
1059         usb_mtp_add_u32(d, 0x00000000);
1060         usb_mtp_add_u8(d, 0x00);
1061         break;
1062     case PROP_OBJECT_COMPRESSED_SIZE:
1063         usb_mtp_add_u16(d, PROP_OBJECT_COMPRESSED_SIZE);
1064         usb_mtp_add_u16(d, DATA_TYPE_UINT64);
1065         usb_mtp_add_u8(d, 0x00);
1066         usb_mtp_add_u64(d, 0x0000000000000000);
1067         usb_mtp_add_u32(d, 0x00000000);
1068         usb_mtp_add_u8(d, 0x00);
1069         break;
1070     case PROP_PARENT_OBJECT:
1071         usb_mtp_add_u16(d, PROP_PARENT_OBJECT);
1072         usb_mtp_add_u16(d, DATA_TYPE_UINT32);
1073         usb_mtp_add_u8(d, 0x00);
1074         usb_mtp_add_u32(d, 0x00000000);
1075         usb_mtp_add_u32(d, 0x00000000);
1076         usb_mtp_add_u8(d, 0x00);
1077         break;
1078     case PROP_PERSISTENT_UNIQUE_OBJECT_IDENTIFIER:
1079         usb_mtp_add_u16(d, PROP_PERSISTENT_UNIQUE_OBJECT_IDENTIFIER);
1080         usb_mtp_add_u16(d, DATA_TYPE_UINT128);
1081         usb_mtp_add_u8(d, 0x00);
1082         usb_mtp_add_u64(d, 0x0000000000000000);
1083         usb_mtp_add_u64(d, 0x0000000000000000);
1084         usb_mtp_add_u32(d, 0x00000000);
1085         usb_mtp_add_u8(d, 0x00);
1086         break;
1087     case PROP_NAME:
1088         usb_mtp_add_u16(d, PROP_NAME);
1089         usb_mtp_add_u16(d, DATA_TYPE_STRING);
1090         usb_mtp_add_u8(d, 0x00);
1091         usb_mtp_add_u8(d, 0x00);
1092         usb_mtp_add_u32(d, 0x00000000);
1093         usb_mtp_add_u8(d, 0x00);
1094         break;
1095     default:
1096         usb_mtp_data_free(d);
1097         return NULL;
1098     }
1099 
1100     return d;
1101 }
1102 
1103 static MTPData *usb_mtp_get_object_prop_value(MTPState *s, MTPControl *c,
1104                                               MTPObject *o)
1105 {
1106     MTPData *d = usb_mtp_data_alloc(c);
1107     switch (c->argv[1]) {
1108     case PROP_STORAGE_ID:
1109         usb_mtp_add_u32(d, QEMU_STORAGE_ID);
1110         break;
1111     case PROP_OBJECT_FORMAT:
1112         usb_mtp_add_u16(d, o->format);
1113         break;
1114     case PROP_OBJECT_COMPRESSED_SIZE:
1115         usb_mtp_add_u64(d, o->stat.st_size);
1116         break;
1117     case PROP_PARENT_OBJECT:
1118         if (o->parent == NULL) {
1119             usb_mtp_add_u32(d, 0x00000000);
1120         } else {
1121             usb_mtp_add_u32(d, o->parent->handle);
1122         }
1123         break;
1124     case PROP_PERSISTENT_UNIQUE_OBJECT_IDENTIFIER:
1125         /* Should be persistent between sessions,
1126          * but using our objedt ID is "good enough"
1127          * for now */
1128         usb_mtp_add_u64(d, 0x0000000000000000);
1129         usb_mtp_add_u64(d, o->handle);
1130         break;
1131     case PROP_NAME:
1132         usb_mtp_add_str(d, o->name);
1133         break;
1134     default:
1135         usb_mtp_data_free(d);
1136         return NULL;
1137     }
1138 
1139     return d;
1140 }
1141 
1142 /*
1143  * Return values when object @o is deleted.
1144  * If at least one of the deletions succeeded,
1145  * DELETE_SUCCESS is set and if at least one
1146  * of the deletions failed, DELETE_FAILURE is
1147  * set. Both bits being set (DELETE_PARTIAL)
1148  * signifies a  RES_PARTIAL_DELETE being sent
1149  * back to the initiator.
1150  */
1151 enum {
1152     DELETE_SUCCESS = (1 << 0),
1153     DELETE_FAILURE = (1 << 1),
1154     DELETE_PARTIAL = (DELETE_FAILURE | DELETE_SUCCESS),
1155 };
1156 
1157 static int usb_mtp_deletefn(MTPState *s, MTPObject *o, uint32_t trans)
1158 {
1159     MTPObject *iter, *iter2;
1160     int ret = 0;
1161 
1162     /*
1163      * TODO: Add support for Protection Status
1164      */
1165 
1166     QLIST_FOREACH(iter, &o->children, list) {
1167         if (iter->format == FMT_ASSOCIATION) {
1168             QLIST_FOREACH(iter2, &iter->children, list) {
1169                 ret |= usb_mtp_deletefn(s, iter2, trans);
1170             }
1171         }
1172     }
1173 
1174     if (o->format == FMT_UNDEFINED_OBJECT) {
1175         if (remove(o->path)) {
1176             ret |= DELETE_FAILURE;
1177         } else {
1178             usb_mtp_object_free(s, o);
1179             ret |= DELETE_SUCCESS;
1180         }
1181     } else if (o->format == FMT_ASSOCIATION) {
1182         if (rmdir(o->path)) {
1183             ret |= DELETE_FAILURE;
1184         } else {
1185             usb_mtp_object_free(s, o);
1186             ret |= DELETE_SUCCESS;
1187         }
1188     }
1189 
1190     return ret;
1191 }
1192 
1193 static void usb_mtp_object_delete(MTPState *s, uint32_t handle,
1194                                   uint32_t format_code, uint32_t trans)
1195 {
1196     MTPObject *o;
1197     int ret;
1198 
1199     /* Return error if store is read-only */
1200     if (!FLAG_SET(s, MTP_FLAG_WRITABLE)) {
1201         usb_mtp_queue_result(s, RES_STORE_READ_ONLY,
1202                              trans, 0, 0, 0, 0);
1203         return;
1204     }
1205 
1206     if (format_code != 0) {
1207         usb_mtp_queue_result(s, RES_SPEC_BY_FORMAT_UNSUPPORTED,
1208                              trans, 0, 0, 0, 0);
1209         return;
1210     }
1211 
1212     if (handle == 0xFFFFFFF) {
1213         o = QTAILQ_FIRST(&s->objects);
1214     } else {
1215         o = usb_mtp_object_lookup(s, handle);
1216     }
1217     if (o == NULL) {
1218         usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1219                              trans, 0, 0, 0, 0);
1220         return;
1221     }
1222 
1223     ret = usb_mtp_deletefn(s, o, trans);
1224     switch (ret) {
1225     case DELETE_SUCCESS:
1226         usb_mtp_queue_result(s, RES_OK, trans,
1227                              0, 0, 0, 0);
1228         break;
1229     case DELETE_FAILURE:
1230         usb_mtp_queue_result(s, RES_PARTIAL_DELETE,
1231                              trans, 0, 0, 0, 0);
1232         break;
1233     case DELETE_PARTIAL:
1234         usb_mtp_queue_result(s, RES_PARTIAL_DELETE,
1235                              trans, 0, 0, 0, 0);
1236         break;
1237     default:
1238         g_assert_not_reached();
1239     }
1240 
1241     return;
1242 }
1243 
1244 static void usb_mtp_command(MTPState *s, MTPControl *c)
1245 {
1246     MTPData *data_in = NULL;
1247     MTPObject *o = NULL;
1248     uint32_t nres = 0, res0 = 0;
1249     Error *err = NULL;
1250 
1251     /* sanity checks */
1252     if (c->code >= CMD_CLOSE_SESSION && s->session == 0) {
1253         usb_mtp_queue_result(s, RES_SESSION_NOT_OPEN,
1254                              c->trans, 0, 0, 0, 0);
1255         return;
1256     }
1257 
1258     /* process commands */
1259     switch (c->code) {
1260     case CMD_GET_DEVICE_INFO:
1261         data_in = usb_mtp_get_device_info(s, c);
1262         break;
1263     case CMD_OPEN_SESSION:
1264         if (s->session) {
1265             usb_mtp_queue_result(s, RES_SESSION_ALREADY_OPEN,
1266                                  c->trans, 1, s->session, 0, 0);
1267             return;
1268         }
1269         if (c->argv[0] == 0) {
1270             usb_mtp_queue_result(s, RES_INVALID_PARAMETER,
1271                                  c->trans, 0, 0, 0, 0);
1272             return;
1273         }
1274         trace_usb_mtp_op_open_session(s->dev.addr);
1275         s->session = c->argv[0];
1276         usb_mtp_object_alloc(s, s->next_handle++, NULL, s->root);
1277 
1278         s->file_monitor = qemu_file_monitor_new(&err);
1279         if (err) {
1280             error_reportf_err(err,
1281                               "usb-mtp: file monitoring init failed: ");
1282             error_free(err);
1283         } else {
1284             QTAILQ_INIT(&s->events);
1285         }
1286         break;
1287     case CMD_CLOSE_SESSION:
1288         trace_usb_mtp_op_close_session(s->dev.addr);
1289         s->session = 0;
1290         s->next_handle = 0;
1291         usb_mtp_file_monitor_cleanup(s);
1292         usb_mtp_object_free(s, QTAILQ_FIRST(&s->objects));
1293         assert(QTAILQ_EMPTY(&s->objects));
1294         break;
1295     case CMD_GET_STORAGE_IDS:
1296         data_in = usb_mtp_get_storage_ids(s, c);
1297         break;
1298     case CMD_GET_STORAGE_INFO:
1299         if (c->argv[0] != QEMU_STORAGE_ID &&
1300             c->argv[0] != 0xffffffff) {
1301             usb_mtp_queue_result(s, RES_INVALID_STORAGE_ID,
1302                                  c->trans, 0, 0, 0, 0);
1303             return;
1304         }
1305         data_in = usb_mtp_get_storage_info(s, c);
1306         break;
1307     case CMD_GET_NUM_OBJECTS:
1308     case CMD_GET_OBJECT_HANDLES:
1309         if (c->argv[0] != QEMU_STORAGE_ID &&
1310             c->argv[0] != 0xffffffff) {
1311             usb_mtp_queue_result(s, RES_INVALID_STORAGE_ID,
1312                                  c->trans, 0, 0, 0, 0);
1313             return;
1314         }
1315         if (c->argv[1] != 0x00000000) {
1316             usb_mtp_queue_result(s, RES_SPEC_BY_FORMAT_UNSUPPORTED,
1317                                  c->trans, 0, 0, 0, 0);
1318             return;
1319         }
1320         if (c->argv[2] == 0x00000000 ||
1321             c->argv[2] == 0xffffffff) {
1322             o = QTAILQ_FIRST(&s->objects);
1323         } else {
1324             o = usb_mtp_object_lookup(s, c->argv[2]);
1325         }
1326         if (o == NULL) {
1327             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1328                                  c->trans, 0, 0, 0, 0);
1329             return;
1330         }
1331         if (o->format != FMT_ASSOCIATION) {
1332             usb_mtp_queue_result(s, RES_INVALID_PARENT_OBJECT,
1333                                  c->trans, 0, 0, 0, 0);
1334             return;
1335         }
1336         usb_mtp_object_readdir(s, o);
1337         if (c->code == CMD_GET_NUM_OBJECTS) {
1338             trace_usb_mtp_op_get_num_objects(s->dev.addr, o->handle, o->path);
1339             nres = 1;
1340             res0 = o->nchildren;
1341         } else {
1342             data_in = usb_mtp_get_object_handles(s, c, o);
1343         }
1344         break;
1345     case CMD_GET_OBJECT_INFO:
1346         o = usb_mtp_object_lookup(s, c->argv[0]);
1347         if (o == NULL) {
1348             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1349                                  c->trans, 0, 0, 0, 0);
1350             return;
1351         }
1352         data_in = usb_mtp_get_object_info(s, c, o);
1353         break;
1354     case CMD_GET_OBJECT:
1355         o = usb_mtp_object_lookup(s, c->argv[0]);
1356         if (o == NULL) {
1357             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1358                                  c->trans, 0, 0, 0, 0);
1359             return;
1360         }
1361         if (o->format == FMT_ASSOCIATION) {
1362             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1363                                  c->trans, 0, 0, 0, 0);
1364             return;
1365         }
1366         data_in = usb_mtp_get_object(s, c, o);
1367         if (data_in == NULL) {
1368             usb_mtp_queue_result(s, RES_GENERAL_ERROR,
1369                                  c->trans, 0, 0, 0, 0);
1370             return;
1371         }
1372         break;
1373     case CMD_DELETE_OBJECT:
1374         usb_mtp_object_delete(s, c->argv[0], c->argv[1], c->trans);
1375         return;
1376     case CMD_GET_PARTIAL_OBJECT:
1377         o = usb_mtp_object_lookup(s, c->argv[0]);
1378         if (o == NULL) {
1379             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1380                                  c->trans, 0, 0, 0, 0);
1381             return;
1382         }
1383         if (o->format == FMT_ASSOCIATION) {
1384             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1385                                  c->trans, 0, 0, 0, 0);
1386             return;
1387         }
1388         data_in = usb_mtp_get_partial_object(s, c, o);
1389         if (data_in == NULL) {
1390             usb_mtp_queue_result(s, RES_GENERAL_ERROR,
1391                                  c->trans, 0, 0, 0, 0);
1392             return;
1393         }
1394         nres = 1;
1395         res0 = data_in->length;
1396         break;
1397     case CMD_SEND_OBJECT_INFO:
1398         /* Return error if store is read-only */
1399         if (!FLAG_SET(s, MTP_FLAG_WRITABLE)) {
1400             usb_mtp_queue_result(s, RES_STORE_READ_ONLY,
1401                                  c->trans, 0, 0, 0, 0);
1402         } else if (c->argv[0] && (c->argv[0] != QEMU_STORAGE_ID)) {
1403             /* First parameter points to storage id or is 0 */
1404             usb_mtp_queue_result(s, RES_STORE_NOT_AVAILABLE, c->trans,
1405                                  0, 0, 0, 0);
1406         } else if (c->argv[1] && !c->argv[0]) {
1407             /* If second parameter is specified, first must also be specified */
1408             usb_mtp_queue_result(s, RES_DESTINATION_UNSUPPORTED, c->trans,
1409                                  0, 0, 0, 0);
1410         } else {
1411             uint32_t handle = c->argv[1];
1412             if (handle == 0xFFFFFFFF || handle == 0) {
1413                 /* root object */
1414                 o = QTAILQ_FIRST(&s->objects);
1415             } else {
1416                 o = usb_mtp_object_lookup(s, handle);
1417             }
1418             if (o == NULL) {
1419                 usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE, c->trans,
1420                                      0, 0, 0, 0);
1421             } else if (o->format != FMT_ASSOCIATION) {
1422                 usb_mtp_queue_result(s, RES_INVALID_PARENT_OBJECT, c->trans,
1423                                      0, 0, 0, 0);
1424             }
1425         }
1426         if (o) {
1427             s->dataset.parent_handle = o->handle;
1428         }
1429         s->data_out = usb_mtp_data_alloc(c);
1430         return;
1431     case CMD_SEND_OBJECT:
1432         if (!FLAG_SET(s, MTP_FLAG_WRITABLE)) {
1433             usb_mtp_queue_result(s, RES_STORE_READ_ONLY,
1434                                  c->trans, 0, 0, 0, 0);
1435             return;
1436         }
1437         if (!s->write_pending) {
1438             usb_mtp_queue_result(s, RES_INVALID_OBJECTINFO,
1439                                  c->trans, 0, 0, 0, 0);
1440             return;
1441         }
1442         s->data_out = usb_mtp_data_alloc(c);
1443         return;
1444     case CMD_GET_OBJECT_PROPS_SUPPORTED:
1445         if (c->argv[0] != FMT_UNDEFINED_OBJECT &&
1446             c->argv[0] != FMT_ASSOCIATION) {
1447             usb_mtp_queue_result(s, RES_INVALID_OBJECT_FORMAT_CODE,
1448                                  c->trans, 0, 0, 0, 0);
1449             return;
1450         }
1451         data_in = usb_mtp_get_object_props_supported(s, c);
1452         break;
1453     case CMD_GET_OBJECT_PROP_DESC:
1454         if (c->argv[1] != FMT_UNDEFINED_OBJECT &&
1455             c->argv[1] != FMT_ASSOCIATION) {
1456             usb_mtp_queue_result(s, RES_INVALID_OBJECT_FORMAT_CODE,
1457                                  c->trans, 0, 0, 0, 0);
1458             return;
1459         }
1460         data_in = usb_mtp_get_object_prop_desc(s, c);
1461         if (data_in == NULL) {
1462             usb_mtp_queue_result(s, RES_INVALID_OBJECT_PROP_CODE,
1463                                  c->trans, 0, 0, 0, 0);
1464             return;
1465         }
1466         break;
1467     case CMD_GET_OBJECT_PROP_VALUE:
1468         o = usb_mtp_object_lookup(s, c->argv[0]);
1469         if (o == NULL) {
1470             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
1471                                  c->trans, 0, 0, 0, 0);
1472             return;
1473         }
1474         data_in = usb_mtp_get_object_prop_value(s, c, o);
1475         if (data_in == NULL) {
1476             usb_mtp_queue_result(s, RES_INVALID_OBJECT_PROP_CODE,
1477                                  c->trans, 0, 0, 0, 0);
1478             return;
1479         }
1480         break;
1481     default:
1482         trace_usb_mtp_op_unknown(s->dev.addr, c->code);
1483         usb_mtp_queue_result(s, RES_OPERATION_NOT_SUPPORTED,
1484                              c->trans, 0, 0, 0, 0);
1485         return;
1486     }
1487 
1488     /* return results on success */
1489     if (data_in) {
1490         assert(s->data_in == NULL);
1491         s->data_in = data_in;
1492     }
1493     usb_mtp_queue_result(s, RES_OK, c->trans, nres, res0, 0, 0);
1494 }
1495 
1496 /* ----------------------------------------------------------------------- */
1497 
1498 static void usb_mtp_handle_reset(USBDevice *dev)
1499 {
1500     MTPState *s = USB_MTP(dev);
1501 
1502     trace_usb_mtp_reset(s->dev.addr);
1503 
1504     usb_mtp_file_monitor_cleanup(s);
1505     usb_mtp_object_free(s, QTAILQ_FIRST(&s->objects));
1506     s->session = 0;
1507     usb_mtp_data_free(s->data_in);
1508     s->data_in = NULL;
1509     usb_mtp_data_free(s->data_out);
1510     s->data_out = NULL;
1511     g_free(s->result);
1512     s->result = NULL;
1513 }
1514 
1515 static void usb_mtp_handle_control(USBDevice *dev, USBPacket *p,
1516                                    int request, int value, int index,
1517                                    int length, uint8_t *data)
1518 {
1519     int ret;
1520     MTPState *s = USB_MTP(dev);
1521     uint16_t *event = (uint16_t *)data;
1522 
1523     switch (request) {
1524     case ClassInterfaceOutRequest | 0x64:
1525         if (*event == EVT_CANCEL_TRANSACTION) {
1526             g_free(s->result);
1527             s->result = NULL;
1528             usb_mtp_data_free(s->data_in);
1529             s->data_in = NULL;
1530             if (s->write_pending) {
1531                 g_free(s->dataset.filename);
1532                 s->write_pending = false;
1533                 s->dataset.size = 0;
1534             }
1535             usb_mtp_data_free(s->data_out);
1536             s->data_out = NULL;
1537         } else {
1538             p->status = USB_RET_STALL;
1539         }
1540         break;
1541     default:
1542         ret = usb_desc_handle_control(dev, p, request,
1543                                       value, index, length, data);
1544         if (ret >= 0) {
1545             return;
1546         }
1547     }
1548 
1549     trace_usb_mtp_stall(dev->addr, "unknown control request");
1550 }
1551 
1552 static void usb_mtp_cancel_packet(USBDevice *dev, USBPacket *p)
1553 {
1554     /* we don't use async packets, so this should never be called */
1555     fprintf(stderr, "%s\n", __func__);
1556 }
1557 
1558 static char *utf16_to_str(uint8_t len, uint8_t *str16)
1559 {
1560     wchar_t *wstr = g_new0(wchar_t, len + 1);
1561     int count, dlen;
1562     char *dest;
1563 
1564     for (count = 0; count < len; count++) {
1565         /* FIXME: not working for surrogate pairs */
1566         wstr[count] = lduw_le_p(str16 + (count * 2));
1567     }
1568     wstr[count] = 0;
1569 
1570     dlen = wcstombs(NULL, wstr, 0) + 1;
1571     dest = g_malloc(dlen);
1572     wcstombs(dest, wstr, dlen);
1573     g_free(wstr);
1574     return dest;
1575 }
1576 
1577 /* Wrapper around write, returns 0 on failure */
1578 static uint64_t write_retry(int fd, void *buf, uint64_t size, off_t offset)
1579 {
1580         uint64_t ret = 0;
1581 
1582         if (lseek(fd, offset, SEEK_SET) < 0) {
1583             goto done;
1584         }
1585 
1586         ret = qemu_write_full(fd, buf, size);
1587 
1588 done:
1589         return ret;
1590 }
1591 
1592 static int usb_mtp_update_object(MTPObject *parent, char *name)
1593 {
1594     int ret = 0;
1595 
1596     MTPObject *o =
1597         usb_mtp_object_lookup_name(parent, name, strlen(name));
1598 
1599     if (o) {
1600         ret = lstat(o->path, &o->stat);
1601     }
1602 
1603     return ret;
1604 }
1605 
1606 static void usb_mtp_write_data(MTPState *s, uint32_t handle)
1607 {
1608     MTPData *d = s->data_out;
1609     MTPObject *parent =
1610         usb_mtp_object_lookup(s, s->dataset.parent_handle);
1611     char *path = NULL;
1612     uint64_t rc;
1613     mode_t mask = 0644;
1614     int ret = 0;
1615 
1616     assert(d != NULL);
1617 
1618     switch (d->write_status) {
1619     case WRITE_START:
1620         if (!parent || !s->write_pending) {
1621             usb_mtp_queue_result(s, RES_INVALID_OBJECTINFO, d->trans,
1622                 0, 0, 0, 0);
1623             return;
1624         }
1625 
1626         if (s->dataset.filename) {
1627             path = g_strdup_printf("%s/%s", parent->path, s->dataset.filename);
1628             if (s->dataset.format == FMT_ASSOCIATION) {
1629                 ret = mkdir(path, mask);
1630                 if (!ret) {
1631                     usb_mtp_queue_result(s, RES_OK, d->trans, 3,
1632                                          QEMU_STORAGE_ID,
1633                                          s->dataset.parent_handle,
1634                                          handle);
1635                     goto close;
1636                 }
1637                 goto done;
1638             }
1639 
1640             d->fd = open(path, O_CREAT | O_WRONLY |
1641                          O_CLOEXEC | O_NOFOLLOW, mask);
1642             if (d->fd == -1) {
1643                 ret = 1;
1644                 goto done;
1645             }
1646 
1647             /* Return success if initiator sent 0 sized data */
1648             if (!s->dataset.size) {
1649                 goto done;
1650             }
1651             if (d->length != MTP_WRITE_BUF_SZ && !d->pending) {
1652                 d->write_status = WRITE_END;
1653             }
1654         }
1655         /* fall through */
1656     case WRITE_CONTINUE:
1657     case WRITE_END:
1658         rc = write_retry(d->fd, d->data, d->data_offset,
1659                          d->offset - d->data_offset);
1660         if (rc != d->data_offset) {
1661             ret = 1;
1662             goto done;
1663         }
1664         if (d->write_status != WRITE_END) {
1665             g_free(path);
1666             return;
1667         } else {
1668             /*
1669              * Return an incomplete transfer if file size doesn't match
1670              * for < 4G file or if lstat fails which will result in an incorrect
1671              * file size
1672              */
1673             if ((s->dataset.size != 0xFFFFFFFF &&
1674                  d->offset != s->dataset.size) ||
1675                 usb_mtp_update_object(parent, s->dataset.filename)) {
1676                 usb_mtp_queue_result(s, RES_INCOMPLETE_TRANSFER, d->trans,
1677                                      0, 0, 0, 0);
1678                 goto close;
1679             }
1680         }
1681     }
1682 
1683 done:
1684     if (ret) {
1685         usb_mtp_queue_result(s, RES_STORE_FULL, d->trans,
1686                              0, 0, 0, 0);
1687     } else {
1688         usb_mtp_queue_result(s, RES_OK, d->trans,
1689                              0, 0, 0, 0);
1690     }
1691 close:
1692     /*
1693      * The write dataset is kept around and freed only
1694      * on success or if another write request comes in
1695      */
1696     if (d->fd != -1) {
1697         close(d->fd);
1698         d->fd = -1;
1699     }
1700     g_free(s->dataset.filename);
1701     s->dataset.size = 0;
1702     g_free(path);
1703     s->write_pending = false;
1704 }
1705 
1706 static void usb_mtp_write_metadata(MTPState *s, uint64_t dlen)
1707 {
1708     MTPData *d = s->data_out;
1709     ObjectInfo *dataset = (ObjectInfo *)d->data;
1710     char *filename;
1711     MTPObject *o;
1712     MTPObject *p = usb_mtp_object_lookup(s, s->dataset.parent_handle);
1713     uint32_t next_handle = s->next_handle;
1714     size_t filename_chars = dlen - offsetof(ObjectInfo, filename);
1715 
1716     /*
1717      * filename is utf-16. We're intentionally doing
1718      * integer division to truncate if malicious guest
1719      * sent an odd number of bytes.
1720      */
1721     filename_chars /= 2;
1722 
1723     assert(!s->write_pending);
1724     assert(p != NULL);
1725 
1726     filename = utf16_to_str(MIN(dataset->length, filename_chars),
1727                             dataset->filename);
1728 
1729     if (strchr(filename, '/')) {
1730         usb_mtp_queue_result(s, RES_PARAMETER_NOT_SUPPORTED, d->trans,
1731                              0, 0, 0, 0);
1732         g_free(filename);
1733         return;
1734     }
1735 
1736     o = usb_mtp_object_lookup_name(p, filename, -1);
1737     if (o != NULL) {
1738         next_handle = o->handle;
1739     }
1740 
1741     s->dataset.filename = filename;
1742     s->dataset.format = dataset->format;
1743     s->dataset.size = dataset->size;
1744     s->write_pending = true;
1745 
1746     if (s->dataset.format == FMT_ASSOCIATION) {
1747         usb_mtp_write_data(s, next_handle);
1748     } else {
1749         usb_mtp_queue_result(s, RES_OK, d->trans, 3, QEMU_STORAGE_ID,
1750                              s->dataset.parent_handle, next_handle);
1751     }
1752 }
1753 
1754 static void usb_mtp_get_data(MTPState *s, mtp_container *container,
1755                              USBPacket *p)
1756 {
1757     MTPData *d = s->data_out;
1758     uint64_t dlen;
1759     uint32_t data_len = p->iov.size;
1760     uint64_t total_len;
1761 
1762     if (!d) {
1763             usb_mtp_queue_result(s, RES_INVALID_OBJECTINFO, 0,
1764                                  0, 0, 0, 0);
1765             return;
1766     }
1767     if (d->first) {
1768         /* Total length of incoming data */
1769         total_len = cpu_to_le32(container->length) - sizeof(mtp_container);
1770         /* Length of data in this packet */
1771         data_len -= sizeof(mtp_container);
1772         if (total_len < MTP_WRITE_BUF_SZ) {
1773                 usb_mtp_realloc(d, total_len);
1774                 d->length += total_len;
1775         } else {
1776                 usb_mtp_realloc(d, MTP_WRITE_BUF_SZ - sizeof(mtp_container));
1777                 d->length += MTP_WRITE_BUF_SZ - sizeof(mtp_container);
1778         }
1779         d->offset = 0;
1780         d->first = false;
1781         d->pending = false;
1782         d->data_offset = 0;
1783         d->write_status = WRITE_START;
1784     }
1785 
1786     if (d->pending) {
1787         memset(d->data, 0, d->length);
1788         if (d->length != MTP_WRITE_BUF_SZ) {
1789             usb_mtp_realloc(d, MTP_WRITE_BUF_SZ - d->length);
1790             d->length += (MTP_WRITE_BUF_SZ - d->length);
1791         }
1792         d->pending = false;
1793         d->write_status = WRITE_CONTINUE;
1794         d->data_offset = 0;
1795     }
1796 
1797     if (d->length - d->data_offset > data_len) {
1798         dlen = data_len;
1799     } else {
1800         dlen = d->length - d->data_offset;
1801     }
1802 
1803     switch (d->code) {
1804     case CMD_SEND_OBJECT_INFO:
1805         usb_packet_copy(p, d->data + d->data_offset, dlen);
1806         d->offset += dlen;
1807         d->data_offset += dlen;
1808         if (d->data_offset == d->length) {
1809             /* The operation might have already failed */
1810             if (!s->result) {
1811                 usb_mtp_write_metadata(s, dlen);
1812             }
1813             usb_mtp_data_free(s->data_out);
1814             s->data_out = NULL;
1815             return;
1816         }
1817         break;
1818     case CMD_SEND_OBJECT:
1819         usb_packet_copy(p, d->data + d->data_offset, dlen);
1820         d->offset += dlen;
1821         d->data_offset += dlen;
1822         if ((p->iov.size % 64) || !p->iov.size) {
1823             assert((s->dataset.size == 0xFFFFFFFF) ||
1824                    (s->dataset.size == d->offset));
1825 
1826             if (d->length == MTP_WRITE_BUF_SZ) {
1827                 d->write_status = WRITE_END;
1828             } else {
1829                 d->write_status = WRITE_START;
1830             }
1831             usb_mtp_write_data(s, 0);
1832             usb_mtp_data_free(s->data_out);
1833             s->data_out = NULL;
1834             return;
1835         }
1836         if (d->data_offset == d->length) {
1837             d->pending = true;
1838             usb_mtp_write_data(s, 0);
1839         }
1840         break;
1841     default:
1842         p->status = USB_RET_STALL;
1843         return;
1844     }
1845 }
1846 
1847 static void usb_mtp_handle_data(USBDevice *dev, USBPacket *p)
1848 {
1849     MTPState *s = USB_MTP(dev);
1850     MTPControl cmd;
1851     mtp_container container;
1852     uint32_t params[5];
1853     uint16_t container_type;
1854     int i, rc;
1855 
1856     switch (p->ep->nr) {
1857     case EP_DATA_IN:
1858         if (s->data_out != NULL) {
1859             /* guest bug */
1860             trace_usb_mtp_stall(s->dev.addr, "awaiting data-out");
1861             p->status = USB_RET_STALL;
1862             return;
1863         }
1864         if (p->iov.size < sizeof(container)) {
1865             trace_usb_mtp_stall(s->dev.addr, "packet too small");
1866             p->status = USB_RET_STALL;
1867             return;
1868         }
1869         if (s->data_in !=  NULL) {
1870             MTPData *d = s->data_in;
1871             uint64_t dlen = d->length - d->offset;
1872             if (d->first) {
1873                 trace_usb_mtp_data_in(s->dev.addr, d->trans, d->length);
1874                 if (d->length + sizeof(container) > 0xFFFFFFFF) {
1875                     container.length = cpu_to_le32(0xFFFFFFFF);
1876                 } else {
1877                     container.length =
1878                         cpu_to_le32(d->length + sizeof(container));
1879                 }
1880                 container.type   = cpu_to_le16(TYPE_DATA);
1881                 container.code   = cpu_to_le16(d->code);
1882                 container.trans  = cpu_to_le32(d->trans);
1883                 usb_packet_copy(p, &container, sizeof(container));
1884                 d->first = false;
1885                 if (dlen > p->iov.size - sizeof(container)) {
1886                     dlen = p->iov.size - sizeof(container);
1887                 }
1888             } else {
1889                 if (dlen > p->iov.size) {
1890                     dlen = p->iov.size;
1891                 }
1892             }
1893             if (d->fd == -1) {
1894                 usb_packet_copy(p, d->data + d->offset, dlen);
1895             } else {
1896                 if (d->alloc < p->iov.size) {
1897                     d->alloc = p->iov.size;
1898                     d->data = g_realloc(d->data, d->alloc);
1899                 }
1900                 rc = read(d->fd, d->data, dlen);
1901                 if (rc != dlen) {
1902                     memset(d->data, 0, dlen);
1903                     s->result->code = RES_INCOMPLETE_TRANSFER;
1904                 }
1905                 usb_packet_copy(p, d->data, dlen);
1906             }
1907             d->offset += dlen;
1908             if (d->offset == d->length) {
1909                 usb_mtp_data_free(s->data_in);
1910                 s->data_in = NULL;
1911             }
1912         } else if (s->result != NULL) {
1913             MTPControl *r = s->result;
1914             int length = sizeof(container) + r->argc * sizeof(uint32_t);
1915             if (r->code == RES_OK) {
1916                 trace_usb_mtp_success(s->dev.addr, r->trans,
1917                                       (r->argc > 0) ? r->argv[0] : 0,
1918                                       (r->argc > 1) ? r->argv[1] : 0);
1919             } else {
1920                 trace_usb_mtp_error(s->dev.addr, r->code, r->trans,
1921                                     (r->argc > 0) ? r->argv[0] : 0,
1922                                     (r->argc > 1) ? r->argv[1] : 0);
1923             }
1924             container.length = cpu_to_le32(length);
1925             container.type   = cpu_to_le16(TYPE_RESPONSE);
1926             container.code   = cpu_to_le16(r->code);
1927             container.trans  = cpu_to_le32(r->trans);
1928             for (i = 0; i < r->argc; i++) {
1929                 params[i] = cpu_to_le32(r->argv[i]);
1930             }
1931             usb_packet_copy(p, &container, sizeof(container));
1932             usb_packet_copy(p, &params, length - sizeof(container));
1933             g_free(s->result);
1934             s->result = NULL;
1935         }
1936         break;
1937     case EP_DATA_OUT:
1938         if (p->iov.size < sizeof(container)) {
1939             trace_usb_mtp_stall(s->dev.addr, "packet too small");
1940             p->status = USB_RET_STALL;
1941             return;
1942         }
1943         if ((s->data_out != NULL) && !s->data_out->first) {
1944             container_type = TYPE_DATA;
1945         } else {
1946             usb_packet_copy(p, &container, sizeof(container));
1947             container_type = le16_to_cpu(container.type);
1948         }
1949         switch (container_type) {
1950         case TYPE_COMMAND:
1951             if (s->data_in || s->data_out || s->result) {
1952                 trace_usb_mtp_stall(s->dev.addr, "transaction inflight");
1953                 p->status = USB_RET_STALL;
1954                 return;
1955             }
1956             cmd.code = le16_to_cpu(container.code);
1957             cmd.argc = (le32_to_cpu(container.length) - sizeof(container))
1958                 / sizeof(uint32_t);
1959             cmd.trans = le32_to_cpu(container.trans);
1960             if (cmd.argc > ARRAY_SIZE(cmd.argv)) {
1961                 cmd.argc = ARRAY_SIZE(cmd.argv);
1962             }
1963             if (p->iov.size < sizeof(container) + cmd.argc * sizeof(uint32_t)) {
1964                 trace_usb_mtp_stall(s->dev.addr, "packet too small");
1965                 p->status = USB_RET_STALL;
1966                 return;
1967             }
1968             usb_packet_copy(p, &params, cmd.argc * sizeof(uint32_t));
1969             for (i = 0; i < cmd.argc; i++) {
1970                 cmd.argv[i] = le32_to_cpu(params[i]);
1971             }
1972             trace_usb_mtp_command(s->dev.addr, cmd.code, cmd.trans,
1973                                   (cmd.argc > 0) ? cmd.argv[0] : 0,
1974                                   (cmd.argc > 1) ? cmd.argv[1] : 0,
1975                                   (cmd.argc > 2) ? cmd.argv[2] : 0,
1976                                   (cmd.argc > 3) ? cmd.argv[3] : 0,
1977                                   (cmd.argc > 4) ? cmd.argv[4] : 0);
1978             usb_mtp_command(s, &cmd);
1979             break;
1980         case TYPE_DATA:
1981             /* One of the previous transfers has already errored but the
1982              * responder is still sending data associated with it
1983              */
1984             if (s->result != NULL) {
1985                 return;
1986             }
1987             usb_mtp_get_data(s, &container, p);
1988             break;
1989         default:
1990             /* not needed as long as the mtp device is read-only */
1991             p->status = USB_RET_STALL;
1992             return;
1993         }
1994         break;
1995     case EP_EVENT:
1996         if (!QTAILQ_EMPTY(&s->events)) {
1997             struct MTPMonEntry *e = QTAILQ_LAST(&s->events);
1998             uint32_t handle;
1999             int len = sizeof(container) + sizeof(uint32_t);
2000 
2001             if (p->iov.size < len) {
2002                 trace_usb_mtp_stall(s->dev.addr,
2003                                     "packet too small to send event");
2004                 p->status = USB_RET_STALL;
2005                 return;
2006             }
2007 
2008             QTAILQ_REMOVE(&s->events, e, next);
2009             container.length = cpu_to_le32(len);
2010             container.type = cpu_to_le32(TYPE_EVENT);
2011             container.code = cpu_to_le16(e->event);
2012             container.trans = 0; /* no trans specific events */
2013             handle = cpu_to_le32(e->handle);
2014             usb_packet_copy(p, &container, sizeof(container));
2015             usb_packet_copy(p, &handle, sizeof(uint32_t));
2016             g_free(e);
2017             return;
2018         }
2019         p->status = USB_RET_NAK;
2020         return;
2021     default:
2022         trace_usb_mtp_stall(s->dev.addr, "invalid endpoint");
2023         p->status = USB_RET_STALL;
2024         return;
2025     }
2026 
2027     if (p->actual_length == 0) {
2028         trace_usb_mtp_nak(s->dev.addr, p->ep->nr);
2029         p->status = USB_RET_NAK;
2030         return;
2031     } else {
2032         trace_usb_mtp_xfer(s->dev.addr, p->ep->nr, p->actual_length,
2033                            p->iov.size);
2034         return;
2035     }
2036 }
2037 
2038 static void usb_mtp_realize(USBDevice *dev, Error **errp)
2039 {
2040     MTPState *s = USB_MTP(dev);
2041 
2042     if ((s->root == NULL) || !g_path_is_absolute(s->root)) {
2043         error_setg(errp, "usb-mtp: rootdir must be configured and be an absolute path");
2044         return;
2045     }
2046 
2047     if (access(s->root, R_OK) != 0) {
2048         error_setg(errp, "usb-mtp: rootdir does not exist/not readable");
2049         return;
2050     } else if (!s->readonly && access(s->root, W_OK) != 0) {
2051         error_setg(errp, "usb-mtp: rootdir does not have write permissions");
2052         return;
2053     }
2054 
2055     /* Mark store as RW */
2056     if (!s->readonly) {
2057         s->flags |= (1 << MTP_FLAG_WRITABLE);
2058     }
2059 
2060     if (s->desc == NULL) {
2061         /*
2062          * This does not check if path exists
2063          * but we have the checks above
2064          */
2065         s->desc = g_path_get_basename(s->root);
2066     }
2067 
2068     usb_desc_create_serial(dev);
2069     usb_desc_init(dev);
2070     QTAILQ_INIT(&s->objects);
2071 
2072 }
2073 
2074 static const VMStateDescription vmstate_usb_mtp = {
2075     .name = "usb-mtp",
2076     .unmigratable = 1,
2077     .version_id = 1,
2078     .minimum_version_id = 1,
2079     .fields = (VMStateField[]) {
2080         VMSTATE_USB_DEVICE(dev, MTPState),
2081         VMSTATE_END_OF_LIST()
2082     }
2083 };
2084 
2085 static Property mtp_properties[] = {
2086     DEFINE_PROP_STRING("rootdir", MTPState, root),
2087     DEFINE_PROP_STRING("desc", MTPState, desc),
2088     DEFINE_PROP_BOOL("readonly", MTPState, readonly, true),
2089     DEFINE_PROP_END_OF_LIST(),
2090 };
2091 
2092 static void usb_mtp_class_initfn(ObjectClass *klass, void *data)
2093 {
2094     DeviceClass *dc = DEVICE_CLASS(klass);
2095     USBDeviceClass *uc = USB_DEVICE_CLASS(klass);
2096 
2097     uc->realize        = usb_mtp_realize;
2098     uc->product_desc   = "QEMU USB MTP";
2099     uc->usb_desc       = &desc;
2100     uc->cancel_packet  = usb_mtp_cancel_packet;
2101     uc->handle_attach  = usb_desc_attach;
2102     uc->handle_reset   = usb_mtp_handle_reset;
2103     uc->handle_control = usb_mtp_handle_control;
2104     uc->handle_data    = usb_mtp_handle_data;
2105     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
2106     dc->desc = "USB Media Transfer Protocol device";
2107     dc->fw_name = "mtp";
2108     dc->vmsd = &vmstate_usb_mtp;
2109     device_class_set_props(dc, mtp_properties);
2110 }
2111 
2112 static TypeInfo mtp_info = {
2113     .name          = TYPE_USB_MTP,
2114     .parent        = TYPE_USB_DEVICE,
2115     .instance_size = sizeof(MTPState),
2116     .class_init    = usb_mtp_class_initfn,
2117 };
2118 
2119 static void usb_mtp_register_types(void)
2120 {
2121     type_register_static(&mtp_info);
2122 }
2123 
2124 type_init(usb_mtp_register_types)
2125