[Qemu-devel] [PULL 0/5] Usb 20180227 patches

[Qemu-devel] [PULL 0/5] Usb 20180227 patches

[Gerd Hoffmann]

The following changes since commit 0a773d55ac76c5aa89ed9187a3bc5af8c5c2a6d0:

  maintainers: Add myself as a OpenBSD maintainer (2018-02-23 12:05:07 +0000)

are available in the git repository at:

  git://git.kraxel.org/qemu tags/usb-20180227-pull-request

for you to fetch changes up to 53735bef108c5ccddf0f8a65cde4da53a48dbd47:

  usb-mtp: Advertise SendObjectInfo for write support (2018-02-26 12:18:36 +0100)

----------------------------------------------------------------
usb: add mtp write support.

----------------------------------------------------------------

Bandan Das (5):
  usb-mtp: Add one more argument when building results
  usb-mtp: print parent path in IN_IGNORED trace fn
  usb-mtp: Support delete of mtp objects
  usb-mtp: Introduce write support for MTP objects
  usb-mtp: Advertise SendObjectInfo for write support

 hw/usb/dev-mtp.c | 471 +++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 441 insertions(+), 30 deletions(-)

-- 
2.9.3

[Qemu-devel] [PULL 1/5] usb-mtp: Add one more argument when building results

[Gerd Hoffmann]

From: Bandan Das <bsd@redhat.com>

The response to a SendObjectInfo consists of the storageid,
parent obejct handle and the handle reserved for the new
incoming object

Signed-off-by: Bandan Das <bsd@redhat.com>
Message-id: 20180223164829.29683-2-bsd@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/usb/dev-mtp.c | 50 +++++++++++++++++++++++++++-----------------------
 1 file changed, 27 insertions(+), 23 deletions(-)

diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c
index 94c2e94f10..b55aa8205e 100644
--- a/hw/usb/dev-mtp.c
+++ b/hw/usb/dev-mtp.c
@@ -765,7 +765,8 @@ static void usb_mtp_add_time(MTPData *data, time_t time)
 /* ----------------------------------------------------------------------- */
 
 static void usb_mtp_queue_result(MTPState *s, uint16_t code, uint32_t trans,
-                                 int argc, uint32_t arg0, uint32_t arg1)
+                                 int argc, uint32_t arg0, uint32_t arg1,
+                                 uint32_t arg2)
 {
     MTPControl *c = g_new0(MTPControl, 1);
 
@@ -778,6 +779,9 @@ static void usb_mtp_queue_result(MTPState *s, uint16_t code, uint32_t trans,
     if (argc > 1) {
         c->argv[1] = arg1;
     }
+    if (argc > 2) {
+        c->argv[2] = arg2;
+    }
 
     assert(s->result == NULL);
     s->result = c;
@@ -1119,7 +1123,7 @@ static void usb_mtp_command(MTPState *s, MTPControl *c)
     /* sanity checks */
     if (c->code >= CMD_CLOSE_SESSION && s->session == 0) {
         usb_mtp_queue_result(s, RES_SESSION_NOT_OPEN,
-                             c->trans, 0, 0, 0);
+                             c->trans, 0, 0, 0, 0);
         return;
     }
 
@@ -1131,12 +1135,12 @@ static void usb_mtp_command(MTPState *s, MTPControl *c)
     case CMD_OPEN_SESSION:
         if (s->session) {
             usb_mtp_queue_result(s, RES_SESSION_ALREADY_OPEN,
-                                 c->trans, 1, s->session, 0);
+                                 c->trans, 1, s->session, 0, 0);
             return;
         }
         if (c->argv[0] == 0) {
             usb_mtp_queue_result(s, RES_INVALID_PARAMETER,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         trace_usb_mtp_op_open_session(s->dev.addr);
@@ -1165,7 +1169,7 @@ static void usb_mtp_command(MTPState *s, MTPControl *c)
         if (c->argv[0] != QEMU_STORAGE_ID &&
             c->argv[0] != 0xffffffff) {
             usb_mtp_queue_result(s, RES_INVALID_STORAGE_ID,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         data_in = usb_mtp_get_storage_info(s, c);
@@ -1175,12 +1179,12 @@ static void usb_mtp_command(MTPState *s, MTPControl *c)
         if (c->argv[0] != QEMU_STORAGE_ID &&
             c->argv[0] != 0xffffffff) {
             usb_mtp_queue_result(s, RES_INVALID_STORAGE_ID,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         if (c->argv[1] != 0x00000000) {
             usb_mtp_queue_result(s, RES_SPEC_BY_FORMAT_UNSUPPORTED,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         if (c->argv[2] == 0x00000000 ||
@@ -1191,12 +1195,12 @@ static void usb_mtp_command(MTPState *s, MTPControl *c)
         }
         if (o == NULL) {
             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         if (o->format != FMT_ASSOCIATION) {
             usb_mtp_queue_result(s, RES_INVALID_PARENT_OBJECT,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         usb_mtp_object_readdir(s, o);
@@ -1212,7 +1216,7 @@ static void usb_mtp_command(MTPState *s, MTPControl *c)
         o = usb_mtp_object_lookup(s, c->argv[0]);
         if (o == NULL) {
             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         data_in = usb_mtp_get_object_info(s, c, o);
@@ -1221,18 +1225,18 @@ static void usb_mtp_command(MTPState *s, MTPControl *c)
         o = usb_mtp_object_lookup(s, c->argv[0]);
         if (o == NULL) {
             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         if (o->format == FMT_ASSOCIATION) {
             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         data_in = usb_mtp_get_object(s, c, o);
         if (data_in == NULL) {
             usb_mtp_queue_result(s, RES_GENERAL_ERROR,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         break;
@@ -1240,18 +1244,18 @@ static void usb_mtp_command(MTPState *s, MTPControl *c)
         o = usb_mtp_object_lookup(s, c->argv[0]);
         if (o == NULL) {
             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         if (o->format == FMT_ASSOCIATION) {
             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         data_in = usb_mtp_get_partial_object(s, c, o);
         if (data_in == NULL) {
             usb_mtp_queue_result(s, RES_GENERAL_ERROR,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         nres = 1;
@@ -1261,7 +1265,7 @@ static void usb_mtp_command(MTPState *s, MTPControl *c)
         if (c->argv[0] != FMT_UNDEFINED_OBJECT &&
             c->argv[0] != FMT_ASSOCIATION) {
             usb_mtp_queue_result(s, RES_INVALID_OBJECT_FORMAT_CODE,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         data_in = usb_mtp_get_object_props_supported(s, c);
@@ -1270,13 +1274,13 @@ static void usb_mtp_command(MTPState *s, MTPControl *c)
         if (c->argv[1] != FMT_UNDEFINED_OBJECT &&
             c->argv[1] != FMT_ASSOCIATION) {
             usb_mtp_queue_result(s, RES_INVALID_OBJECT_FORMAT_CODE,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         data_in = usb_mtp_get_object_prop_desc(s, c);
         if (data_in == NULL) {
             usb_mtp_queue_result(s, RES_INVALID_OBJECT_PROP_CODE,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         break;
@@ -1284,20 +1288,20 @@ static void usb_mtp_command(MTPState *s, MTPControl *c)
         o = usb_mtp_object_lookup(s, c->argv[0]);
         if (o == NULL) {
             usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         data_in = usb_mtp_get_object_prop_value(s, c, o);
         if (data_in == NULL) {
             usb_mtp_queue_result(s, RES_INVALID_OBJECT_PROP_CODE,
-                                 c->trans, 0, 0, 0);
+                                 c->trans, 0, 0, 0, 0);
             return;
         }
         break;
     default:
         trace_usb_mtp_op_unknown(s->dev.addr, c->code);
         usb_mtp_queue_result(s, RES_OPERATION_NOT_SUPPORTED,
-                             c->trans, 0, 0, 0);
+                             c->trans, 0, 0, 0, 0);
         return;
     }
 
@@ -1306,7 +1310,7 @@ static void usb_mtp_command(MTPState *s, MTPControl *c)
         assert(s->data_in == NULL);
         s->data_in = data_in;
     }
-    usb_mtp_queue_result(s, RES_OK, c->trans, nres, res0, 0);
+    usb_mtp_queue_result(s, RES_OK, c->trans, nres, res0, 0, 0);
 }
 
 /* ----------------------------------------------------------------------- */
-- 
2.9.3

[Qemu-devel] [PULL 2/5] usb-mtp: print parent path in IN_IGNORED trace fn

[Gerd Hoffmann]

From: Bandan Das <bsd@redhat.com>

Fix a possible null dereference when deleting a folder and
its contents. An ignored event might be received for its contents
after the parent folder is deleted which will return a null object.

Signed-off-by: Bandan Das <bsd@redhat.com>
Message-id: 20180223164829.29683-3-bsd@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/usb/dev-mtp.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c
index b55aa8205e..63f8f3b90b 100644
--- a/hw/usb/dev-mtp.c
+++ b/hw/usb/dev-mtp.c
@@ -540,9 +540,8 @@ static void inotify_watchfn(void *arg)
                 break;
 
             case IN_IGNORED:
-                o = usb_mtp_object_lookup_name(parent, event->name, event->len);
-                trace_usb_mtp_inotify_event(s->dev.addr, o->path,
-                                      event->mask, "Obj ignored");
+                trace_usb_mtp_inotify_event(s->dev.addr, parent->path,
+                                      event->mask, "Obj parent dir ignored");
                 break;
 
             default:
-- 
2.9.3

[Qemu-devel] [PULL 3/5] usb-mtp: Support delete of mtp objects

[Gerd Hoffmann]

From: Bandan Das <bsd@redhat.com>

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: Bandan Das <bsd@redhat.com>
Message-id: 20180223164829.29683-4-bsd@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/usb/dev-mtp.c | 123 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 123 insertions(+)

diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c
index 63f8f3b90b..5ef77f3e9f 100644
--- a/hw/usb/dev-mtp.c
+++ b/hw/usb/dev-mtp.c
@@ -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(),
 };
 
-- 
2.9.3

Re: [Qemu-devel] [PULL 3/5] usb-mtp: Support delete of mtp objects

[Peter Maydell]

On Tue, 27 Feb 2018 at 08:41, Gerd Hoffmann <kraxel@redhat.com> wrote:
>
> From: Bandan Das <bsd@redhat.com>
>
> 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.

Hi -- Coverity points out a use-after-free here (CID 1399144):



> +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);

This call will call g_free(o)...

> +            success = true;
> +        }
> +    }
> +
> +    if (o->format == FMT_ASSOCIATION) {

...but flow of control then falls through to here, where
we try to access o->format.

Preusumably this should be an "else if" clause ?
> +        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;
> +}
> +

thanks
-- PMM

[Qemu-devel] [PULL 4/5] usb-mtp: Introduce write support for MTP objects

[Gerd Hoffmann]

From: Bandan Das <bsd@redhat.com>

Allow write operations on behalf of the initiator. The
precursor to write is the sending of the write metadata
that consists of the ObjectInfo dataset. This patch introduces
a flag that is set when the responder is ready to receive
write data based on a previous SendObjectInfo operation by
the initiator (The SendObjectInfo implementation is in a
later patch)

Signed-off-by: Bandan Das <bsd@redhat.com>
Message-id: 20180223164829.29683-5-bsd@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/usb/dev-mtp.c | 157 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 155 insertions(+), 2 deletions(-)

diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c
index 5ef77f3e9f..ecb37828d5 100644
--- a/hw/usb/dev-mtp.c
+++ b/hw/usb/dev-mtp.c
@@ -47,6 +47,7 @@ enum mtp_code {
     CMD_GET_OBJECT_INFO            = 0x1008,
     CMD_GET_OBJECT                 = 0x1009,
     CMD_DELETE_OBJECT              = 0x100b,
+    CMD_SEND_OBJECT                = 0x100d,
     CMD_GET_PARTIAL_OBJECT         = 0x101b,
     CMD_GET_OBJECT_PROPS_SUPPORTED = 0x9801,
     CMD_GET_OBJECT_PROP_DESC       = 0x9802,
@@ -63,9 +64,11 @@ enum mtp_code {
     RES_INVALID_STORAGE_ID         = 0x2008,
     RES_INVALID_OBJECT_HANDLE      = 0x2009,
     RES_INVALID_OBJECT_FORMAT_CODE = 0x200b,
+    RES_STORE_FULL                 = 0x200c,
     RES_STORE_READ_ONLY            = 0x200e,
     RES_PARTIAL_DELETE             = 0x2012,
     RES_SPEC_BY_FORMAT_UNSUPPORTED = 0x2014,
+    RES_INVALID_OBJECTINFO         = 0x2015,
     RES_INVALID_PARENT_OBJECT      = 0x201a,
     RES_INVALID_PARAMETER          = 0x201d,
     RES_SESSION_ALREADY_OPEN       = 0x201e,
@@ -183,6 +186,14 @@ struct MTPState {
     int          inotifyfd;
     QTAILQ_HEAD(events, MTPMonEntry) events;
 #endif
+    /* Responder is expecting a write operation */
+    bool write_pending;
+    struct {
+        uint32_t parent_handle;
+        uint16_t format;
+        uint32_t size;
+        char *filename;
+    } dataset;
 };
 
 #define TYPE_USB_MTP "usb-mtp"
@@ -804,6 +815,7 @@ static MTPData *usb_mtp_get_device_info(MTPState *s, MTPControl *c)
         CMD_GET_OBJECT_HANDLES,
         CMD_GET_OBJECT_INFO,
         CMD_DELETE_OBJECT,
+        CMD_SEND_OBJECT,
         CMD_GET_OBJECT,
         CMD_GET_PARTIAL_OBJECT,
         CMD_GET_OBJECT_PROPS_SUPPORTED,
@@ -1378,6 +1390,19 @@ static void usb_mtp_command(MTPState *s, MTPControl *c)
         nres = 1;
         res0 = data_in->length;
         break;
+    case CMD_SEND_OBJECT:
+        if (!FLAG_SET(s, MTP_FLAG_WRITABLE)) {
+            usb_mtp_queue_result(s, RES_STORE_READ_ONLY,
+                                 c->trans, 0, 0, 0, 0);
+            return;
+        }
+        if (!s->write_pending) {
+            usb_mtp_queue_result(s, RES_INVALID_OBJECTINFO,
+                                 c->trans, 0, 0, 0, 0);
+            return;
+        }
+        s->data_out = usb_mtp_data_alloc(c);
+        return;
     case CMD_GET_OBJECT_PROPS_SUPPORTED:
         if (c->argv[0] != FMT_UNDEFINED_OBJECT &&
             c->argv[0] != FMT_ASSOCIATION) {
@@ -1472,12 +1497,126 @@ static void usb_mtp_cancel_packet(USBDevice *dev, USBPacket *p)
     fprintf(stderr, "%s\n", __func__);
 }
 
+static void usb_mtp_write_data(MTPState *s)
+{
+    MTPData *d = s->data_out;
+    MTPObject *parent =
+        usb_mtp_object_lookup(s, s->dataset.parent_handle);
+    char *path = NULL;
+    int rc = -1;
+    mode_t mask = 0644;
+
+    assert(d != NULL);
+
+    if (parent == NULL || !s->write_pending) {
+        usb_mtp_queue_result(s, RES_INVALID_OBJECTINFO, d->trans,
+                             0, 0, 0, 0);
+        return;
+    }
+
+    if (s->dataset.filename) {
+        path = g_strdup_printf("%s/%s", parent->path, s->dataset.filename);
+        if (s->dataset.format == FMT_ASSOCIATION) {
+            d->fd = mkdir(path, mask);
+            goto free;
+        }
+        if (s->dataset.size < d->length) {
+            usb_mtp_queue_result(s, RES_STORE_FULL, d->trans,
+                                 0, 0, 0, 0);
+            goto done;
+        }
+        d->fd = open(path, O_CREAT | O_WRONLY, mask);
+        if (d->fd == -1) {
+            usb_mtp_queue_result(s, RES_STORE_FULL, d->trans,
+                                 0, 0, 0, 0);
+            goto done;
+        }
+
+        /*
+         * Return success if initiator sent 0 sized data
+         */
+        if (!s->dataset.size) {
+            goto success;
+        }
+
+        rc = write(d->fd, d->data, s->dataset.size);
+        if (rc == -1) {
+            usb_mtp_queue_result(s, RES_STORE_FULL, d->trans,
+                                 0, 0, 0, 0);
+            goto done;
+            }
+        if (rc != s->dataset.size) {
+            usb_mtp_queue_result(s, RES_INCOMPLETE_TRANSFER, d->trans,
+                                 0, 0, 0, 0);
+            goto done;
+        }
+    }
+
+success:
+    usb_mtp_queue_result(s, RES_OK, d->trans,
+                         0, 0, 0, 0);
+
+done:
+    /*
+     * The write dataset is kept around and freed only
+     * on success or if another write request comes in
+     */
+    if (d->fd != -1) {
+        close(d->fd);
+    }
+free:
+    g_free(s->dataset.filename);
+    g_free(path);
+    s->write_pending = false;
+}
+
+static void usb_mtp_get_data(MTPState *s, mtp_container *container,
+                             USBPacket *p)
+{
+    MTPData *d = s->data_out;
+    uint64_t dlen;
+    uint32_t data_len = p->iov.size;
+
+    if (d->first) {
+        /* Total length of incoming data */
+        d->length = cpu_to_le32(container->length) - sizeof(mtp_container);
+        /* Length of data in this packet */
+        data_len -= sizeof(mtp_container);
+        usb_mtp_realloc(d, d->length);
+        d->offset = 0;
+        d->first = false;
+    }
+
+    if (d->length - d->offset > data_len) {
+        dlen = data_len;
+    } else {
+        dlen = d->length - d->offset;
+    }
+
+    switch (d->code) {
+    case CMD_SEND_OBJECT:
+        usb_packet_copy(p, d->data + d->offset, dlen);
+        d->offset += dlen;
+        if (d->offset == d->length) {
+            usb_mtp_write_data(s);
+            usb_mtp_data_free(s->data_out);
+            s->data_out = NULL;
+            return;
+        }
+        break;
+    default:
+        p->status = USB_RET_STALL;
+        return;
+    }
+}
+
 static void usb_mtp_handle_data(USBDevice *dev, USBPacket *p)
 {
     MTPState *s = USB_MTP(dev);
     MTPControl cmd;
     mtp_container container;
     uint32_t params[5];
+    uint16_t container_type;
     int i, rc;
 
     switch (p->ep->nr) {
@@ -1567,8 +1706,13 @@ static void usb_mtp_handle_data(USBDevice *dev, USBPacket *p)
             p->status = USB_RET_STALL;
             return;
         }
-        usb_packet_copy(p, &container, sizeof(container));
-        switch (le16_to_cpu(container.type)) {
+        if (s->data_out && !s->data_out->first) {
+            container_type = TYPE_DATA;
+        } else {
+            usb_packet_copy(p, &container, sizeof(container));
+            container_type = le16_to_cpu(container.type);
+        }
+        switch (container_type) {
         case TYPE_COMMAND:
             if (s->data_in || s->data_out || s->result) {
                 trace_usb_mtp_stall(s->dev.addr, "transaction inflight");
@@ -1599,6 +1743,15 @@ static void usb_mtp_handle_data(USBDevice *dev, USBPacket *p)
                                   (cmd.argc > 4) ? cmd.argv[4] : 0);
             usb_mtp_command(s, &cmd);
             break;
+        case TYPE_DATA:
+            /* One of the previous transfers has already errored but the
+             * responder is still sending data associated with it
+             */
+            if (s->result != NULL) {
+                return;
+            }
+            usb_mtp_get_data(s, &container, p);
+            break;
         default:
             /* not needed as long as the mtp device is read-only */
             p->status = USB_RET_STALL;
-- 
2.9.3

Re: [Qemu-devel] [PULL 4/5] usb-mtp: Introduce write support for MTP objects

[Peter Maydell]

On 27 February 2018 at 08:39, Gerd Hoffmann <kraxel@redhat.com> wrote:
> From: Bandan Das <bsd@redhat.com>
>
> Allow write operations on behalf of the initiator. The
> precursor to write is the sending of the write metadata
> that consists of the ObjectInfo dataset. This patch introduces
> a flag that is set when the responder is ready to receive
> write data based on a previous SendObjectInfo operation by
> the initiator (The SendObjectInfo implementation is in a
> later patch)
>
> Signed-off-by: Bandan Das <bsd@redhat.com>
> Message-id: 20180223164829.29683-5-bsd@redhat.com
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Hi. Coverity (CID 1390604) complains here about a possible
use-after-NULL-check:

> @@ -1567,8 +1706,13 @@ static void usb_mtp_handle_data(USBDevice *dev, USBPacket *p)
>              p->status = USB_RET_STALL;
>              return;
>          }
> -        usb_packet_copy(p, &container, sizeof(container));
> -        switch (le16_to_cpu(container.type)) {
> +        if (s->data_out && !s->data_out->first) {
> +            container_type = TYPE_DATA;

Here we check s->data_out, so we might set container_type
to TYPE_DATA with s->data_out == NULL...

> +        } else {
> +            usb_packet_copy(p, &container, sizeof(container));
> +            container_type = le16_to_cpu(container.type);
> +        }
> +        switch (container_type) {
>          case TYPE_COMMAND:
>              if (s->data_in || s->data_out || s->result) {
>                  trace_usb_mtp_stall(s->dev.addr, "transaction inflight");
> @@ -1599,6 +1743,15 @@ static void usb_mtp_handle_data(USBDevice *dev, USBPacket *p)
>                                    (cmd.argc > 4) ? cmd.argv[4] : 0);
>              usb_mtp_command(s, &cmd);
>              break;
> +        case TYPE_DATA:
> +            /* One of the previous transfers has already errored but the
> +             * responder is still sending data associated with it
> +             */
> +            if (s->result != NULL) {
> +                return;
> +            }
> +            usb_mtp_get_data(s, &container, p);

...but here we call usb_mtp_get_data(), which will always
dereference s->data_out, and so will crash if it is NULL.

> +            break;
>          default:
>              /* not needed as long as the mtp device is read-only */
>              p->status = USB_RET_STALL;
> --
> 2.9.3

thanks
-- PMM

Re: [Qemu-devel] [PULL 4/5] usb-mtp: Introduce write support for MTP objects

[Bandan Das]

Peter Maydell <peter.maydell@linaro.org> writes:

> On 27 February 2018 at 08:39, Gerd Hoffmann <kraxel@redhat.com> wrote:
>> From: Bandan Das <bsd@redhat.com>
>>
>> Allow write operations on behalf of the initiator. The
>> precursor to write is the sending of the write metadata
>> that consists of the ObjectInfo dataset. This patch introduces
>> a flag that is set when the responder is ready to receive
>> write data based on a previous SendObjectInfo operation by
>> the initiator (The SendObjectInfo implementation is in a
>> later patch)
>>
>> Signed-off-by: Bandan Das <bsd@redhat.com>
>> Message-id: 20180223164829.29683-5-bsd@redhat.com
>> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
>
> Hi. Coverity (CID 1390604) complains here about a possible
> use-after-NULL-check:
>
>> @@ -1567,8 +1706,13 @@ static void usb_mtp_handle_data(USBDevice *dev, USBPacket *p)
>>              p->status = USB_RET_STALL;
>>              return;
>>          }
>> -        usb_packet_copy(p, &container, sizeof(container));
>> -        switch (le16_to_cpu(container.type)) {
>> +        if (s->data_out && !s->data_out->first) {
>> +            container_type = TYPE_DATA;
>
> Here we check s->data_out, so we might set container_type
> to TYPE_DATA with s->data_out == NULL...

Just to be sure, is it enough to replace the if with:
if (s->data !=NULL && !s->data->first) ?

Bandan

>> +        } else {
>> +            usb_packet_copy(p, &container, sizeof(container));
>> +            container_type = le16_to_cpu(container.type);
>> +        }
>> +        switch (container_type) {
>>          case TYPE_COMMAND:
>>              if (s->data_in || s->data_out || s->result) {
>>                  trace_usb_mtp_stall(s->dev.addr, "transaction inflight");
>> @@ -1599,6 +1743,15 @@ static void usb_mtp_handle_data(USBDevice *dev, USBPacket *p)
>>                                    (cmd.argc > 4) ? cmd.argv[4] : 0);
>>              usb_mtp_command(s, &cmd);
>>              break;
>> +        case TYPE_DATA:
>> +            /* One of the previous transfers has already errored but the
>> +             * responder is still sending data associated with it
>> +             */
>> +            if (s->result != NULL) {
>> +                return;
>> +            }
>> +            usb_mtp_get_data(s, &container, p);
>
> ...but here we call usb_mtp_get_data(), which will always
> dereference s->data_out, and so will crash if it is NULL.
>
>> +            break;
>>          default:
>>              /* not needed as long as the mtp device is read-only */
>>              p->status = USB_RET_STALL;
>> --
>> 2.9.3
>
> thanks
> -- PMM

[Qemu-devel] [PULL 5/5] usb-mtp: Advertise SendObjectInfo for write support

[Gerd Hoffmann]

From: Bandan Das <bsd@redhat.com>

This patch implements a dummy ObjectInfo structure so that
it's easy to typecast the incoming data. If the metadata is
valid, write_pending is set. Also, the incoming filename
is utf-16, so, instead of depending on external libraries, just
implement a simple function to get the filename

Signed-off-by: Bandan Das <bsd@redhat.com>
Message-id: 20180223164829.29683-6-bsd@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/usb/dev-mtp.c | 136 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 134 insertions(+), 2 deletions(-)

diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c
index ecb37828d5..6ecf70a79b 100644
--- a/hw/usb/dev-mtp.c
+++ b/hw/usb/dev-mtp.c
@@ -47,6 +47,7 @@ enum mtp_code {
     CMD_GET_OBJECT_INFO            = 0x1008,
     CMD_GET_OBJECT                 = 0x1009,
     CMD_DELETE_OBJECT              = 0x100b,
+    CMD_SEND_OBJECT_INFO           = 0x100c,
     CMD_SEND_OBJECT                = 0x100d,
     CMD_GET_PARTIAL_OBJECT         = 0x101b,
     CMD_GET_OBJECT_PROPS_SUPPORTED = 0x9801,
@@ -67,8 +68,10 @@ enum mtp_code {
     RES_STORE_FULL                 = 0x200c,
     RES_STORE_READ_ONLY            = 0x200e,
     RES_PARTIAL_DELETE             = 0x2012,
+    RES_STORE_NOT_AVAILABLE        = 0x2013,
     RES_SPEC_BY_FORMAT_UNSUPPORTED = 0x2014,
     RES_INVALID_OBJECTINFO         = 0x2015,
+    RES_DESTINATION_UNSUPPORTED    = 0x2020,
     RES_INVALID_PARENT_OBJECT      = 0x201a,
     RES_INVALID_PARAMETER          = 0x201d,
     RES_SESSION_ALREADY_OPEN       = 0x201e,
@@ -196,6 +199,34 @@ struct MTPState {
     } dataset;
 };
 
+/*
+ * ObjectInfo dataset received from initiator
+ * Fields we don't care about are ignored
+ */
+typedef struct {
+    uint32_t storage_id; /*unused*/
+    uint16_t format;
+    uint16_t protection_status; /*unused*/
+    uint32_t size;
+    uint16_t thumb_format; /*unused*/
+    uint32_t thumb_comp_sz; /*unused*/
+    uint32_t thumb_pix_width; /*unused*/
+    uint32_t thumb_pix_height; /*unused*/
+    uint32_t image_pix_width; /*unused*/
+    uint32_t image_pix_height; /*unused*/
+    uint32_t image_bit_depth; /*unused*/
+    uint32_t parent; /*unused*/
+    uint16_t assoc_type;
+    uint32_t assoc_desc;
+    uint32_t seq_no; /*unused*/
+    uint8_t length; /*part of filename field*/
+    uint16_t filename[0];
+    char date_created[0]; /*unused*/
+    char date_modified[0]; /*unused*/
+    char keywords[0]; /*unused*/
+    /* string and other data follows */
+} QEMU_PACKED ObjectInfo;
+
 #define TYPE_USB_MTP "usb-mtp"
 #define USB_MTP(obj) OBJECT_CHECK(MTPState, (obj), TYPE_USB_MTP)
 
@@ -437,7 +468,6 @@ static MTPObject *usb_mtp_add_child(MTPState *s, MTPObject *o,
     return child;
 }
 
-#ifdef CONFIG_INOTIFY1
 static MTPObject *usb_mtp_object_lookup_name(MTPObject *parent,
                                              char *name, int len)
 {
@@ -452,6 +482,7 @@ static MTPObject *usb_mtp_object_lookup_name(MTPObject *parent,
     return NULL;
 }
 
+#ifdef CONFIG_INOTIFY1
 static MTPObject *usb_mtp_object_lookup_wd(MTPState *s, int wd)
 {
     MTPObject *iter;
@@ -815,6 +846,7 @@ static MTPData *usb_mtp_get_device_info(MTPState *s, MTPControl *c)
         CMD_GET_OBJECT_HANDLES,
         CMD_GET_OBJECT_INFO,
         CMD_DELETE_OBJECT,
+        CMD_SEND_OBJECT_INFO,
         CMD_SEND_OBJECT,
         CMD_GET_OBJECT,
         CMD_GET_PARTIAL_OBJECT,
@@ -1243,7 +1275,7 @@ static void usb_mtp_object_delete(MTPState *s, uint32_t handle,
 static void usb_mtp_command(MTPState *s, MTPControl *c)
 {
     MTPData *data_in = NULL;
-    MTPObject *o;
+    MTPObject *o = NULL;
     uint32_t nres = 0, res0 = 0;
 
     /* sanity checks */
@@ -1390,6 +1422,41 @@ static void usb_mtp_command(MTPState *s, MTPControl *c)
         nres = 1;
         res0 = data_in->length;
         break;
+    case CMD_SEND_OBJECT_INFO:
+        /* Return error if store is read-only */
+        if (!FLAG_SET(s, MTP_FLAG_WRITABLE)) {
+            usb_mtp_queue_result(s, RES_STORE_READ_ONLY,
+                                 c->trans, 0, 0, 0, 0);
+        } else if (c->argv[0] && (c->argv[0] != QEMU_STORAGE_ID)) {
+            /* First parameter points to storage id or is 0 */
+            usb_mtp_queue_result(s, RES_STORE_NOT_AVAILABLE, c->trans,
+                                 0, 0, 0, 0);
+        } else if (c->argv[1] && !c->argv[0]) {
+            /* If second parameter is specified, first must also be specified */
+            usb_mtp_queue_result(s, RES_DESTINATION_UNSUPPORTED, c->trans,
+                                 0, 0, 0, 0);
+        } else {
+            uint32_t handle = c->argv[1];
+            if (handle == 0xFFFFFFFF || handle == 0) {
+                /* root object */
+                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, c->trans,
+                                     0, 0, 0, 0);
+            }
+            if (o->format != FMT_ASSOCIATION) {
+                usb_mtp_queue_result(s, RES_INVALID_PARENT_OBJECT, c->trans,
+                                     0, 0, 0, 0);
+            }
+        }
+        if (o) {
+            s->dataset.parent_handle = o->handle;
+        }
+        s->data_out = usb_mtp_data_alloc(c);
+        return;
     case CMD_SEND_OBJECT:
         if (!FLAG_SET(s, MTP_FLAG_WRITABLE)) {
             usb_mtp_queue_result(s, RES_STORE_READ_ONLY,
@@ -1497,6 +1564,19 @@ static void usb_mtp_cancel_packet(USBDevice *dev, USBPacket *p)
     fprintf(stderr, "%s\n", __func__);
 }
 
+static void utf16_to_str(uint8_t len, uint16_t *arr, char *name)
+{
+    int count;
+    wchar_t *wstr = g_new0(wchar_t, len);
+
+    for (count = 0; count < len; count++) {
+        wstr[count] = (wchar_t)arr[count];
+    }
+
+    wcstombs(name, wstr, len);
+    g_free(wstr);
+}
+
 static void usb_mtp_write_data(MTPState *s)
 {
     MTPData *d = s->data_out;
@@ -1570,6 +1650,45 @@ free:
     s->write_pending = false;
 }
 
+static void usb_mtp_write_metadata(MTPState *s)
+{
+    MTPData *d = s->data_out;
+    ObjectInfo *dataset = (ObjectInfo *)d->data;
+    char *filename = g_new0(char, dataset->length);
+    MTPObject *o;
+    MTPObject *p = usb_mtp_object_lookup(s, s->dataset.parent_handle);
+    uint32_t next_handle = s->next_handle;
+
+    assert(!s->write_pending);
+
+    utf16_to_str(dataset->length, dataset->filename, filename);
+
+    o = usb_mtp_object_lookup_name(p, filename, dataset->length);
+    if (o != NULL) {
+        next_handle = o->handle;
+    }
+
+    s->dataset.filename = filename;
+    s->dataset.format = dataset->format;
+    s->dataset.size = dataset->size;
+    s->dataset.filename = filename;
+    s->write_pending = true;
+
+    if (s->dataset.format == FMT_ASSOCIATION) {
+        usb_mtp_write_data(s);
+        /* next_handle will be allocated to the newly created dir */
+        if (d->fd == -1) {
+            usb_mtp_queue_result(s, RES_STORE_FULL, d->trans,
+                                 0, 0, 0, 0);
+            return;
+        }
+        d->fd = -1;
+    }
+
+    usb_mtp_queue_result(s, RES_OK, d->trans, 3, QEMU_STORAGE_ID,
+                         s->dataset.parent_handle, next_handle);
+}
+
 static void usb_mtp_get_data(MTPState *s, mtp_container *container,
                              USBPacket *p)
 {
@@ -1594,6 +1713,19 @@ static void usb_mtp_get_data(MTPState *s, mtp_container *container,
     }
 
     switch (d->code) {
+    case CMD_SEND_OBJECT_INFO:
+        usb_packet_copy(p, d->data + d->offset, dlen);
+        d->offset += dlen;
+        if (d->offset == d->length) {
+            /* The operation might have already failed */
+            if (!s->result) {
+                usb_mtp_write_metadata(s);
+            }
+            usb_mtp_data_free(s->data_out);
+            s->data_out = NULL;
+            return;
+        }
+        break;
     case CMD_SEND_OBJECT:
         usb_packet_copy(p, d->data + d->offset, dlen);
         d->offset += dlen;
-- 
2.9.3

Re: [Qemu-devel] [PULL 5/5] usb-mtp: Advertise SendObjectInfo for write support

[Peter Maydell]

On 27 February 2018 at 08:39, Gerd Hoffmann <kraxel@redhat.com> wrote:
> From: Bandan Das <bsd@redhat.com>
>
> This patch implements a dummy ObjectInfo structure so that
> it's easy to typecast the incoming data. If the metadata is
> valid, write_pending is set. Also, the incoming filename
> is utf-16, so, instead of depending on external libraries, just
> implement a simple function to get the filename

> +static void usb_mtp_write_metadata(MTPState *s)

Hi; Coverity points out a missing error check in this function
(CID 1390578):

> +{
> +    MTPData *d = s->data_out;
> +    ObjectInfo *dataset = (ObjectInfo *)d->data;
> +    char *filename = g_new0(char, dataset->length);
> +    MTPObject *o;
> +    MTPObject *p = usb_mtp_object_lookup(s, s->dataset.parent_handle);

usb_mtp_object_lookup() can return NULL, but we do not check it...

> +    uint32_t next_handle = s->next_handle;
> +
> +    assert(!s->write_pending);
> +
> +    utf16_to_str(dataset->length, dataset->filename, filename);
> +
> +    o = usb_mtp_object_lookup_name(p, filename, dataset->length);

...and if p is NULL here then we will crash in usb_mtp_object_lookup_name().

> +    if (o != NULL) {
> +        next_handle = o->handle;
> +    }
> +
> +    s->dataset.filename = filename;
> +    s->dataset.format = dataset->format;
> +    s->dataset.size = dataset->size;
> +    s->dataset.filename = filename;
> +    s->write_pending = true;
> +
> +    if (s->dataset.format == FMT_ASSOCIATION) {
> +        usb_mtp_write_data(s);
> +        /* next_handle will be allocated to the newly created dir */
> +        if (d->fd == -1) {
> +            usb_mtp_queue_result(s, RES_STORE_FULL, d->trans,
> +                                 0, 0, 0, 0);
> +            return;
> +        }
> +        d->fd = -1;
> +    }
> +
> +    usb_mtp_queue_result(s, RES_OK, d->trans, 3, QEMU_STORAGE_ID,
> +                         s->dataset.parent_handle, next_handle);
> +}
> +

thanks
-- PMM

Re: [Qemu-devel] [PULL 5/5] usb-mtp: Advertise SendObjectInfo for write support

[Peter Maydell]

On 27 February 2018 at 08:39, Gerd Hoffmann <kraxel@redhat.com> wrote:
> From: Bandan Das <bsd@redhat.com>
>
> This patch implements a dummy ObjectInfo structure so that
> it's easy to typecast the incoming data. If the metadata is
> valid, write_pending is set. Also, the incoming filename
> is utf-16, so, instead of depending on external libraries, just
> implement a simple function to get the filename
>
> Signed-off-by: Bandan Das <bsd@redhat.com>
> Message-id: 20180223164829.29683-6-bsd@redhat.com
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  hw/usb/dev-mtp.c | 136 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 134 insertions(+), 2 deletions(-)

Hi; Coverity points out a pointer use-after-NULL-check in this
code (CID1390592):

> +    case CMD_SEND_OBJECT_INFO:
> +        /* Return error if store is read-only */
> +        if (!FLAG_SET(s, MTP_FLAG_WRITABLE)) {
> +            usb_mtp_queue_result(s, RES_STORE_READ_ONLY,
> +                                 c->trans, 0, 0, 0, 0);
> +        } else if (c->argv[0] && (c->argv[0] != QEMU_STORAGE_ID)) {
> +            /* First parameter points to storage id or is 0 */
> +            usb_mtp_queue_result(s, RES_STORE_NOT_AVAILABLE, c->trans,
> +                                 0, 0, 0, 0);
> +        } else if (c->argv[1] && !c->argv[0]) {
> +            /* If second parameter is specified, first must also be specified */
> +            usb_mtp_queue_result(s, RES_DESTINATION_UNSUPPORTED, c->trans,
> +                                 0, 0, 0, 0);
> +        } else {
> +            uint32_t handle = c->argv[1];
> +            if (handle == 0xFFFFFFFF || handle == 0) {
> +                /* root object */
> +                o = QTAILQ_FIRST(&s->objects);
> +            } else {
> +                o = usb_mtp_object_lookup(s, handle);
> +            }
> +            if (o == NULL) {

Here we do a NULL check on 'o'...

> +                usb_mtp_queue_result(s, RES_INVALID_OBJECT_HANDLE, c->trans,
> +                                     0, 0, 0, 0);
> +            }
> +            if (o->format != FMT_ASSOCIATION) {

...but here we dereference 'o', which will crash if it is NULL.

> +                usb_mtp_queue_result(s, RES_INVALID_PARENT_OBJECT, c->trans,
> +                                     0, 0, 0, 0);
> +            }
> +        }
> +        if (o) {
> +            s->dataset.parent_handle = o->handle;
> +        }
> +        s->data_out = usb_mtp_data_alloc(c);
> +        return;

thanks
-- PMM

Re: [Qemu-devel] [PULL 0/5] Usb 20180227 patches

[Peter Maydell]

On 27 February 2018 at 08:39, Gerd Hoffmann <kraxel@redhat.com> wrote:
> The following changes since commit 0a773d55ac76c5aa89ed9187a3bc5af8c5c2a6d0:
>
>   maintainers: Add myself as a OpenBSD maintainer (2018-02-23 12:05:07 +0000)
>
> are available in the git repository at:
>
>   git://git.kraxel.org/qemu tags/usb-20180227-pull-request
>
> for you to fetch changes up to 53735bef108c5ccddf0f8a65cde4da53a48dbd47:
>
>   usb-mtp: Advertise SendObjectInfo for write support (2018-02-26 12:18:36 +0100)
>
> ----------------------------------------------------------------
> usb: add mtp write support.
>
> ----------------------------------------------------------------
>
> Bandan Das (5):
>   usb-mtp: Add one more argument when building results
>   usb-mtp: print parent path in IN_IGNORED trace fn
>   usb-mtp: Support delete of mtp objects
>   usb-mtp: Introduce write support for MTP objects
>   usb-mtp: Advertise SendObjectInfo for write support
>
>  hw/usb/dev-mtp.c | 471 +++++++++++++++++++++++++++++++++++++++++++++++++++----
>  1 file changed, 441 insertions(+), 30 deletions(-)

Applied, thanks.

-- PMM