Commit ec6206a6 authored by Bandan Das's avatar Bandan Das Committed by Gerd Hoffmann
Browse files

usb-mtp: Support delete of mtp objects 



Write of existing objects by the initiator is acheived by
making a temporary buffer with the new changes, deleting the
old file and then writing a new file with the same name.

Also, add a "readonly" property which needs to be set to false
for deletion to work.

Signed-off-by: default avatarBandan Das <bsd@redhat.com>
Message-id: 20180223164829.29683-4-bsd@redhat.com
Signed-off-by: default avatarGerd Hoffmann <kraxel@redhat.com>
parent 5d13ebea

hw/usb/dev-mtp.c

+123 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ enum mtp_code { 
    CMD_GET_OBJECT_HANDLES         = 0x1007,

    CMD_GET_OBJECT_INFO            = 0x1008,

    CMD_GET_OBJECT                 = 0x1009,

    CMD_DELETE_OBJECT              = 0x100b,

    CMD_GET_PARTIAL_OBJECT         = 0x101b,

    CMD_GET_OBJECT_PROPS_SUPPORTED = 0x9801,

    CMD_GET_OBJECT_PROP_DESC       = 0x9802,
@@ -62,6 +63,8 @@ enum mtp_code { 
    RES_INVALID_STORAGE_ID         = 0x2008,

    RES_INVALID_OBJECT_HANDLE      = 0x2009,

    RES_INVALID_OBJECT_FORMAT_CODE = 0x200b,

    RES_STORE_READ_ONLY            = 0x200e,

    RES_PARTIAL_DELETE             = 0x2012,

    RES_SPEC_BY_FORMAT_UNSUPPORTED = 0x2014,

    RES_INVALID_PARENT_OBJECT      = 0x201a,

    RES_INVALID_PARAMETER          = 0x201d,
@@ -172,6 +175,7 @@ struct MTPState { 
    MTPControl   *result;

    uint32_t     session;

    uint32_t     next_handle;

    bool         readonly;



    QTAILQ_HEAD(, MTPObject) objects;

#ifdef CONFIG_INOTIFY1
@@ -799,6 +803,7 @@ static MTPData *usb_mtp_get_device_info(MTPState *s, MTPControl *c) 
        CMD_GET_NUM_OBJECTS,

        CMD_GET_OBJECT_HANDLES,

        CMD_GET_OBJECT_INFO,

        CMD_DELETE_OBJECT,

        CMD_GET_OBJECT,

        CMD_GET_PARTIAL_OBJECT,

        CMD_GET_OBJECT_PROPS_SUPPORTED,
@@ -1113,6 +1118,116 @@ static MTPData *usb_mtp_get_object_prop_value(MTPState *s, MTPControl *c, 
    return d;

}



/* Return correct return code for a delete event */

enum {

    ALL_DELETE,

    PARTIAL_DELETE,

    READ_ONLY,

};



/* Assumes that children, if any, have been already freed */

static void usb_mtp_object_free_one(MTPState *s, MTPObject *o)

{

#ifndef CONFIG_INOTIFY1

    assert(o->nchildren == 0);

    QTAILQ_REMOVE(&s->objects, o, next);

    g_free(o->name);

    g_free(o->path);

    g_free(o);

#endif

}



static int usb_mtp_deletefn(MTPState *s, MTPObject *o, uint32_t trans)

{

    MTPObject *iter, *iter2;

    bool partial_delete = false;

    bool success = false;



    /*

     * TODO: Add support for Protection Status

     */



    QLIST_FOREACH(iter, &o->children, list) {

        if (iter->format == FMT_ASSOCIATION) {

            QLIST_FOREACH(iter2, &iter->children, list) {

                usb_mtp_deletefn(s, iter2, trans);

            }

        }

    }



    if (o->format == FMT_UNDEFINED_OBJECT) {

        if (remove(o->path)) {

            partial_delete = true;

        } else {

            usb_mtp_object_free_one(s, o);

            success = true;

        }

    }



    if (o->format == FMT_ASSOCIATION) {

        if (rmdir(o->path)) {

            partial_delete = true;

        } else {

            usb_mtp_object_free_one(s, o);

            success = true;

        }

    }



    if (success && partial_delete) {

        return PARTIAL_DELETE;

    }

    if (!success && partial_delete) {

        return READ_ONLY;

    }

    return ALL_DELETE;

}



static void usb_mtp_object_delete(MTPState *s, uint32_t handle,

                                  uint32_t format_code, uint32_t trans)

{

    MTPObject *o;

    int ret;



    /* Return error if store is read-only */

    if (!FLAG_SET(s, MTP_FLAG_WRITABLE)) {

        usb_mtp_queue_result(s, RES_STORE_READ_ONLY,

                             trans, 0, 0, 0, 0);

        return;

    }



    if (format_code != 0) {

        usb_mtp_queue_result(s, RES_SPEC_BY_FORMAT_UNSUPPORTED,

                             trans, 0, 0, 0, 0);

        return;

    }



    if (handle == 0xFFFFFFF) {

        o = QTAILQ_FIRST(&s->objects);

    } else {

        o = usb_mtp_object_lookup(s, handle);

    }

    if (o == NULL) {

        usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,

                             trans, 0, 0, 0, 0);

        return;

    }



    ret = usb_mtp_deletefn(s, o, trans);

    if (ret == PARTIAL_DELETE) {

        usb_mtp_queue_result(s, RES_PARTIAL_DELETE,

                             trans, 0, 0, 0, 0);

        return;

    } else if (ret == READ_ONLY) {

        usb_mtp_queue_result(s, RES_STORE_READ_ONLY, trans,

                             0, 0, 0, 0);

        return;

    } else {

        usb_mtp_queue_result(s, RES_OK, trans,

                             0, 0, 0, 0);

        return;

    }

}



static void usb_mtp_command(MTPState *s, MTPControl *c)

{

    MTPData *data_in = NULL;
@@ -1239,6 +1354,9 @@ static void usb_mtp_command(MTPState *s, MTPControl *c) 
            return;

        }

        break;

    case CMD_DELETE_OBJECT:

        usb_mtp_object_delete(s, c->argv[0], c->argv[1], c->trans);

        return;

    case CMD_GET_PARTIAL_OBJECT:

        o = usb_mtp_object_lookup(s, c->argv[0]);

        if (o == NULL) {
@@ -1545,6 +1663,10 @@ static void usb_mtp_realize(USBDevice *dev, Error **errp) 
            return;

        }

        s->desc = strrchr(s->root, '/');

        /* Mark store as RW */

        if (!s->readonly) {

            s->flags |= (1 << MTP_FLAG_WRITABLE);

        }

        if (s->desc && s->desc[0]) {

            s->desc = g_strdup(s->desc + 1);

        } else {
@@ -1567,6 +1689,7 @@ static const VMStateDescription vmstate_usb_mtp = { 
static Property mtp_properties[] = {

    DEFINE_PROP_STRING("x-root", MTPState, root),

    DEFINE_PROP_STRING("desc", MTPState, desc),

    DEFINE_PROP_BOOL("readonly", MTPState, readonly, true),

    DEFINE_PROP_END_OF_LIST(),

};