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[24.9.64.241]) by smtp.gmail.com with ESMTPSA id 24sm3612863oij.58.2021.03.29.13.06.57 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 29 Mar 2021 13:06:58 -0700 (PDT) Subject: Re: [PATCH v5] docs: usbip: Fix major fields and descriptions in protocol To: "Hongren Zheng (Zenithal)" , Valentina Manea , Shuah Khan , Greg Kroah-Hartman , =?UTF-8?B?TcOhcnRvbiBOw6ltZXRo?= , Jonathan Corbet , linux-doc@vger.kernel.org Cc: Alexandre Demers , linux-usb@vger.kernel.org, usbip-devel@lists.sourceforge.net, Randy Dunlap , Shuah Khan References: From: Shuah Khan Message-ID: <51edf4bb-1b00-a3b8-4277-25c282588858@linuxfoundation.org> Date: Mon, 29 Mar 2021 14:06:56 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 3/15/21 8:25 PM, Hongren Zheng (Zenithal) wrote: > The old document for usbip protocol is misleading and hard to read: > * Some fields in header are incorrect > * Explanation of some fields are unclear or even wrong > * Padding of header (namely all headers have the same length) is > not explicitly pointed out, which is crucial for stream protocol > like TCP > > Major changes: > * Document the correct field as described in the codebase. > * Document the padding in usbip headers. This is crucial for TCP > stream hence these padding should be explicitly point out. > In code these padding are implemented by a union of all headers. > * Fix two FIXME related to usbip unlink and Document the behavior > of unlink in different situation. > * Clarify some field with more accurate explanation, like those > fields associated with URB. Some constraints are extracted from > code. > * Delete specific transfer_flag doc in usbip as it should be > documented by the URB part. Why are we deleting this. What do you mean documented by URB part? > * Add data captured from wire as example > > Co-developed-by: Alexandre Demers > Reviewed-by: Randy Dunlap > Signed-off-by: Hongren Zheng > --- > Documentation/usb/usbip_protocol.rst | 320 ++++++++++++++------------- > 1 file changed, 171 insertions(+), 149 deletions(-) > > PATCH v2: > Some changes suggested by a previous patch in > https://lore.kernel.org/linux-usb > /20180128071514.9107-1-alexandre.f.demers@gmail.com/ > is adopted in this patch. > * Fix Typo: duplicated 'the' in 'the following 4 field' > * Fix incorrect field: in OP_REQ_DEVLIST, the second dev starts with > field 'path', not 'busid' > > PATCH v3: > Suggested by > https://lore.kernel.org/linux-doc/YE8Oan2BmSuKR4%2Fp@kroah.com/ > * Remove date and changelog in doc as these are tracked in git history > * Remove 'mistake alert' as all data fields are documented properly > now. However, docs on possible values for some field shall be added > in the future > > PATCH v4: > Suggested by https://lore.kernel.org/linux-doc > /40351ed6-2907-3966-e69a-a564173b3682@infradead.org/ > * Add punctuations for readability > * Move patch changelog after the marker line > * Remove nickname in signed-off-by line > > PATCH v5: > * Instead of co-developed-by, use reviewed-by > for Randy Dunlap > > diff --git a/Documentation/usb/usbip_protocol.rst b/Documentation/usb/usbip_protocol.rst > index 988c832166cd..54c5677adf4e 100644 > --- a/Documentation/usb/usbip_protocol.rst > +++ b/Documentation/usb/usbip_protocol.rst > @@ -2,11 +2,11 @@ > USB/IP protocol > =============== > > -PRELIMINARY DRAFT, MAY CONTAIN MISTAKES> -28 Jun 2011 > +Architecture Let's add doc version preserving the history. Add Version 1 and date perhaps. > +============ > > The USB/IP protocol follows a server/client architecture. The server exports the > -USB devices and the clients imports them. The device driver for the exported > +USB devices and the client imports them. The device driver for the exported clients import them. > USB device runs on the client machine. > > The client may ask for the list of the exported USB devices. To get the list the > @@ -37,6 +37,9 @@ to transfer the URB traffic between the client and the server. The client may > send two types of packets: the USBIP_CMD_SUBMIT to submit an URB, and > USBIP_CMD_UNLINK to unlink a previously submitted URB. The answers of the > server may be USBIP_RET_SUBMIT and USBIP_RET_UNLINK respectively. > +Note that after successful USBIP_RET_UNLINK, the unlinked URB request would not > +have a corresponding USBIP_RET_UNLINK (this is explained in > +drivers/usb/usbip/stub_rx.c). This is not clear to me. Doesn't look correct. Where do you see this in drivers/usb/usbip/stub_rx.c? > > :: > > @@ -85,16 +88,42 @@ server may be USBIP_RET_SUBMIT and USBIP_RET_UNLINK respectively. > | . | > | : | > | | > + | USBIP_CMD_SUBMIT(seqnum = p) | > + | ----------------------------------------------> | > + | | > + | USBIP_CMD_UNLINK | > + | (seqnum = p+1, unlink_seqnum = p) | > + | ----------------------------------------------> | > + | | > + | USBIP_RET_UNLINK | > + | (seqnum = p+1, status = -ECONNRESET) | > + | <---------------------------------------------- | > + | | > + | Note: No USBIP_RET_SUBMIT(seqnum = p) | > + | <--X---X---X---X---X---X---X---X---X---X---X--- | > + | . | > + | : | > + | | > + | USBIP_CMD_SUBMIT(seqnum = q) | > + | ----------------------------------------------> | > + | | > + | USBIP_RET_SUBMIT(seqnum = q) | > + | <---------------------------------------------- | > + | | > | USBIP_CMD_UNLINK | > + | (seqnum = q+1, unlink_seqnum = q) | > | ----------------------------------------------> | > | | > | USBIP_RET_UNLINK | > + | (seqnum = q+1, status = 0) | > | <---------------------------------------------- | > | | > I would do this differently. Let's add this as an expanded USBIP_CMD_UNLINK sequence with a separate heading below the current flow > The fields are in network (big endian) byte order meaning that the most significant > byte (MSB) is stored at the lowest address. > > +Message Format > +============== > > OP_REQ_DEVLIST: > Retrieve the list of exported USB devices. > @@ -102,7 +131,7 @@ OP_REQ_DEVLIST: > +-----------+--------+------------+---------------------------------------------------+ > | Offset | Length | Value | Description | > +===========+========+============+===================================================+ > -| 0 | 2 | 0x0100 | Binary-coded decimal USBIP version number: v1.0.0 | > +| 0 | 2 | 0x0111 | Binary-coded decimal USBIP version number: v1.1.1 | > +-----------+--------+------------+---------------------------------------------------+ Let's make this vx.x.x and specify current version number at the top. Saves us doc updates as we change version number - one location change as opposed to the entire document > | 2 | 2 | 0x8005 | Command code: Retrieve the list of exported USB | > | | | | devices. | > @@ -116,7 +145,7 @@ OP_REP_DEVLIST: > +-----------+--------+------------+---------------------------------------------------+ > | Offset | Length | Value | Description | > +===========+========+============+===================================================+ > -| 0 | 2 | 0x0100 | Binary-coded decimal USBIP version number: v1.0.0.| > +| 0 | 2 | 0x0111 | Binary-coded decimal USBIP version number: v1.1.1 | > +-----------+--------+------------+---------------------------------------------------+ > | 2 | 2 | 0x0005 | Reply code: The list of exported USB devices. | > +-----------+--------+------------+---------------------------------------------------+ > @@ -165,8 +194,8 @@ OP_REP_DEVLIST: > | 0x143 | 1 | | bNumInterfaces | > +-----------+--------+------------+---------------------------------------------------+ > | 0x144 | | m_0 | From now on each interface is described, all | > -| | | | together bNumInterfaces times, with the | > -| | | | the following 4 fields: | > +| | | | together bNumInterfaces times, with the following | > +| | | | 4 fields: | > +-----------+--------+------------+---------------------------------------------------+ > | | 1 | | bInterfaceClass | > +-----------+--------+------------+---------------------------------------------------+ > @@ -177,7 +206,7 @@ OP_REP_DEVLIST: > | 0x147 | 1 | | padding byte for alignment, shall be set to zero | > +-----------+--------+------------+---------------------------------------------------+ > | 0xC + | | | The second exported USB device starts at i=1 | > -| i*0x138 + | | | with the busid field. | > +| i*0x138 + | | | with the path field. | > | m_(i-1)*4 | | | | > +-----------+--------+------------+---------------------------------------------------+ > > @@ -187,7 +216,7 @@ OP_REQ_IMPORT: > +-----------+--------+------------+---------------------------------------------------+ > | Offset | Length | Value | Description | > +===========+========+============+===================================================+ > -| 0 | 2 | 0x0100 | Binary-coded decimal USBIP version number: v1.0.0 | > +| 0 | 2 | 0x0111 | Binary-coded decimal USBIP version number: v1.1.1 | > +-----------+--------+------------+---------------------------------------------------+ > | 2 | 2 | 0x8003 | Command code: import a remote USB device. | > +-----------+--------+------------+---------------------------------------------------+ > @@ -206,7 +235,7 @@ OP_REP_IMPORT: > +-----------+--------+------------+---------------------------------------------------+ > | Offset | Length | Value | Description | > +===========+========+============+===================================================+ > -| 0 | 2 | 0x0100 | Binary-coded decimal USBIP version number: v1.0.0 | > +| 0 | 2 | 0x0111 | Binary-coded decimal USBIP version number: v1.1.1 | > +-----------+--------+------------+---------------------------------------------------+ > | 2 | 2 | 0x0003 | Reply code: Reply to import. | > +-----------+--------+------------+---------------------------------------------------+ > @@ -254,158 +283,151 @@ OP_REP_IMPORT: > | 0x13E | 1 | | bNumInterfaces | > +-----------+--------+------------+---------------------------------------------------+ > > -USBIP_CMD_SUBMIT: > - Submit an URB > +The following four commands have a common basic header called > +'usbip_header_basic', and their headers, called 'usbip_header' (before URB > +payload), have the same length, therefore paddings are needed. > > -+-----------+--------+------------+---------------------------------------------------+ > -| Offset | Length | Value | Description | > -+===========+========+============+===================================================+ > -| 0 | 4 | 0x00000001 | command: Submit an URB | > -+-----------+--------+------------+---------------------------------------------------+ > -| 4 | 4 | | seqnum: the sequence number of the URB to submit | > -+-----------+--------+------------+---------------------------------------------------+ > -| 8 | 4 | | devid | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0xC | 4 | | direction: | > -| | | | | > -| | | | - 0: USBIP_DIR_OUT | > -| | | | - 1: USBIP_DIR_IN | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x10 | 4 | | ep: endpoint number, possible values are: 0...15 | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x14 | 4 | | transfer_flags: possible values depend on the | > -| | | | URB transfer type, see below | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x18 | 4 | | transfer_buffer_length | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x1C | 4 | | start_frame: specify the selected frame to | > -| | | | transmit an ISO frame, ignored if URB_ISO_ASAP | > -| | | | is specified at transfer_flags | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x20 | 4 | | number_of_packets: number of ISO packets | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x24 | 4 | | interval: maximum time for the request on the | > -| | | | server-side host controller | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x28 | 8 | | setup: data bytes for USB setup, filled with | > -| | | | zeros if not used | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x30 | | | URB data. For ISO transfers the padding between | > -| | | | each ISO packets is not transmitted. | > -+-----------+--------+------------+---------------------------------------------------+ > +usbip_header_basic: > > ++-----------+--------+---------------------------------------------------+ > +| Offset | Length | Description | > ++===========+========+===================================================+ > +| 0 | 4 | command | > ++-----------+--------+---------------------------------------------------+ > +| 4 | 4 | seqnum: sequential number that identifies requests| > +| | | and corresponding responses; | > +| | | incremented per connection | > ++-----------+--------+---------------------------------------------------+ > +| 8 | 4 | devid: specifies a remote USB device uniquely | > +| | | instead of busnum and devnum; | > +| | | for client (request), this value is | > +| | | ((busnum << 16) | devnum); | > +| | | for server (response), this shall be set to 0 | > ++-----------+--------+---------------------------------------------------+ > +| 0xC | 4 | direction: | > +| | | | > +| | | - 0: USBIP_DIR_OUT | > +| | | - 1: USBIP_DIR_IN | > +| | | | > +| | | only used by client, for server this shall be 0 | > ++-----------+--------+---------------------------------------------------+ > +| 0x10 | 4 | ep: endpoint number | > +| | | only used by client, for server this shall be 0; | > +| | | for UNLINK, this shall be 0 | > ++-----------+--------+---------------------------------------------------+ > > - +-------------------------+------------+---------+-----------+----------+-------------+ > - | Allowed transfer_flags | value | control | interrupt | bulk | isochronous | > - +=========================+============+=========+===========+==========+=============+ > - | URB_SHORT_NOT_OK | 0x00000001 | only in | only in | only in | no | > - +-------------------------+------------+---------+-----------+----------+-------------+ > - | URB_ISO_ASAP | 0x00000002 | no | no | no | yes | > - +-------------------------+------------+---------+-----------+----------+-------------+ > - | URB_NO_TRANSFER_DMA_MAP | 0x00000004 | yes | yes | yes | yes | > - +-------------------------+------------+---------+-----------+----------+-------------+ > - | URB_ZERO_PACKET | 0x00000040 | no | no | only out | no | > - +-------------------------+------------+---------+-----------+----------+-------------+ > - | URB_NO_INTERRUPT | 0x00000080 | yes | yes | yes | yes | > - +-------------------------+------------+---------+-----------+----------+-------------+ > - | URB_FREE_BUFFER | 0x00000100 | yes | yes | yes | yes | > - +-------------------------+------------+---------+-----------+----------+-------------+ > - | URB_DIR_MASK | 0x00000200 | yes | yes | yes | yes | > - +-------------------------+------------+---------+-----------+----------+-------------+ > +USBIP_CMD_SUBMIT: > + Submit an URB > > ++-----------+--------+---------------------------------------------------+ > +| Offset | Length | Description | > ++===========+========+===================================================+ > +| 0 | 20 | usbip_header_basic, 'command' shall be 0x00000001 | > ++-----------+--------+---------------------------------------------------+ > +| 0x14 | 4 | transfer_flags: possible values depend on the | > +| | | URB transfer_flags, | > +| | | but with URB_NO_TRANSFER_DMA_MAP masked | > ++-----------+--------+---------------------------------------------------+ > +| 0x18 | 4 | transfer_buffer_length: | > +| | | use URB transfer_buffer_length | > ++-----------+--------+---------------------------------------------------+ > +| 0x1C | 4 | start_frame: use URB start_frame; | > +| | | initial frame for ISO transfer; | > +| | | shall be set to 0 if not ISO transfer | > ++-----------+--------+---------------------------------------------------+ > +| 0x20 | 4 | number_of_packets: number of ISO packets; | > +| | | shall be set to 0xffffffff if not ISO transfer | > ++-----------+--------+---------------------------------------------------+ > +| 0x24 | 4 | interval: maximum time for the request on the | > +| | | server-side host controller | > ++-----------+--------+---------------------------------------------------+ > +| 0x28 | 8 | setup: data bytes for USB setup, filled with | > +| | | zeros if not used. | > ++-----------+--------+---------------------------------------------------+ > +| 0x30 | n | transfer_buffer. | > +| | | If direction is USBIP_DIR_OUT then n equals | > +| | | transfer_buffer_length; otherwise n equals 0. | > +| | | For ISO transfers the padding between each ISO | > +| | | packets is not transmitted. | > ++-----------+--------+---------------------------------------------------+ > +| 0x30+n | m | iso_packet_descriptor | > ++-----------+--------+---------------------------------------------------+ > > USBIP_RET_SUBMIT: > Reply for submitting an URB > > -+-----------+--------+------------+---------------------------------------------------+ > -| Offset | Length | Value | Description | > -+===========+========+============+===================================================+ > -| 0 | 4 | 0x00000003 | command | > -+-----------+--------+------------+---------------------------------------------------+ > -| 4 | 4 | | seqnum: URB sequence number | > -+-----------+--------+------------+---------------------------------------------------+ > -| 8 | 4 | | devid | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0xC | 4 | | direction: | > -| | | | | > -| | | | - 0: USBIP_DIR_OUT | > -| | | | - 1: USBIP_DIR_IN | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x10 | 4 | | ep: endpoint number | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x14 | 4 | | status: zero for successful URB transaction, | > -| | | | otherwise some kind of error happened. | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x18 | 4 | n | actual_length: number of URB data bytes | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x1C | 4 | | start_frame: for an ISO frame the actually | > -| | | | selected frame for transmit. | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x20 | 4 | | number_of_packets | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x24 | 4 | | error_count | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x28 | 8 | | setup: data bytes for USB setup, filled with | > -| | | | zeros if not used | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x30 | n | | URB data bytes. For ISO transfers the padding | > -| | | | between each ISO packets is not transmitted. | > -+-----------+--------+------------+---------------------------------------------------+ > ++-----------+--------+---------------------------------------------------+ > +| Offset | Length | Description | > ++===========+========+===================================================+ > +| 0 | 20 | usbip_header_basic, 'command' shall be 0x00000003 | > ++-----------+--------+---------------------------------------------------+ > +| 0x14 | 4 | status: zero for successful URB transaction, | > +| | | otherwise some kind of error happened. | > ++-----------+--------+---------------------------------------------------+ > +| 0x18 | 4 | actual_length: number of URB data bytes; | > +| | | use URB actual_length | > ++-----------+--------+---------------------------------------------------+ > +| 0x1C | 4 | start_frame: use URB start_frame; | > +| | | initial frame for ISO transfer; | > +| | | shall be set to 0 if not ISO transfer | > ++-----------+--------+---------------------------------------------------+ > +| 0x20 | 4 | number_of_packets: number of ISO packets; | > +| | | shall be set to 0xffffffff if not ISO transfer | > ++-----------+--------+---------------------------------------------------+ > +| 0x24 | 4 | error_count | > ++-----------+--------+---------------------------------------------------+ > +| 0x28 | 8 | padding, shall be set to 0 | > ++-----------+--------+---------------------------------------------------+ > +| 0x30 | n | transfer_buffer. | > +| | | If direction is USBIP_DIR_IN then n equals | > +| | | actual_length; otherwise n equals 0. | > +| | | For ISO transfers the padding between each ISO | > +| | | packets is not transmitted. | > ++-----------+--------+---------------------------------------------------+ > +| 0x30+n | m | iso_packet_descriptor | > ++-----------+--------+---------------------------------------------------+ > > USBIP_CMD_UNLINK: > Unlink an URB > > -+-----------+--------+------------+---------------------------------------------------+ > -| Offset | Length | Value | Description | > -+===========+========+============+===================================================+ > -| 0 | 4 | 0x00000002 | command: URB unlink command | > -+-----------+--------+------------+---------------------------------------------------+ > -| 4 | 4 | | seqnum: URB sequence number to unlink: | > -| | | | | > -| | | | FIXME: | > -| | | | is this so? | > -+-----------+--------+------------+---------------------------------------------------+ > -| 8 | 4 | | devid | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0xC | 4 | | direction: | > -| | | | | > -| | | | - 0: USBIP_DIR_OUT | > -| | | | - 1: USBIP_DIR_IN | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x10 | 4 | | ep: endpoint number: zero | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x14 | 4 | | seqnum: the URB sequence number given previously | > -| | | | at USBIP_CMD_SUBMIT.seqnum field | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x30 | n | | URB data bytes. For ISO transfers the padding | > -| | | | between each ISO packets is not transmitted. | > -+-----------+--------+------------+---------------------------------------------------+ > ++-----------+--------+---------------------------------------------------+ > +| Offset | Length | Description | > ++===========+========+===================================================+ > +| 0 | 20 | usbip_header_basic, 'command' shall be 0x00000002 | > ++-----------+--------+---------------------------------------------------+ > +| 0x14 | 4 | unlink_seqnum, of the SUBMIT request to unlink | > ++-----------+--------+---------------------------------------------------+ > +| 0x18 | 24 | padding, shall be set to 0 | > ++-----------+--------+---------------------------------------------------+ > > USBIP_RET_UNLINK: > Reply for URB unlink > > -+-----------+--------+------------+---------------------------------------------------+ > -| Offset | Length | Value | Description | > -+===========+========+============+===================================================+ > -| 0 | 4 | 0x00000004 | command: reply for the URB unlink command | > -+-----------+--------+------------+---------------------------------------------------+ > -| 4 | 4 | | seqnum: the unlinked URB sequence number | > -+-----------+--------+------------+---------------------------------------------------+ > -| 8 | 4 | | devid | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0xC | 4 | | direction: | > -| | | | | > -| | | | - 0: USBIP_DIR_OUT | > -| | | | - 1: USBIP_DIR_IN | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x10 | 4 | | ep: endpoint number | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x14 | 4 | | status: This is the value contained in the | > -| | | | urb->status in the URB completition handler. | > -| | | | | > -| | | | FIXME: | > -| | | | a better explanation needed. | > -+-----------+--------+------------+---------------------------------------------------+ > -| 0x30 | n | | URB data bytes. For ISO transfers the padding | > -| | | | between each ISO packets is not transmitted. | > -+-----------+--------+------------+---------------------------------------------------+ > ++-----------+--------+---------------------------------------------------+ > +| Offset | Length | Description | > ++===========+========+===================================================+ > +| 0 | 20 | usbip_header_basic, 'command' shall be 0x00000004 | > ++-----------+--------+---------------------------------------------------+ > +| 0x14 | 4 | status: This is similar to the status of | > +| | | USBIP_RET_SUBMIT (share the same memory offset). | > +| | | When UNLINK is successful, status is -ECONNRESET; | > +| | | when USBIP_CMD_UNLINK is after USBIP_RET_SUBMIT | > +| | | status is 0 | > ++-----------+--------+---------------------------------------------------+ > +| 0x18 | 24 | padding, shall be set to 0 | > ++-----------+--------+---------------------------------------------------+ > + > +EXAMPLE > +======= > + > + The following data is captured from wire with Human Interface Devices (HID) > + payload > + > +:: > + > + CmdIntrIN: 00000001 00000d05 0001000f 00000001 00000001 00000200 00000040 ffffffff 00000000 00000004 00000000 00000000 > + CmdIntrOUT: 00000001 00000d06 0001000f 00000000 00000001 00000000 00000040 ffffffff 00000000 00000004 00000000 00000000 > + ffffffff860008a784ce5ae212376300000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 > + RetIntrOut: 00000003 00000d06 00000000 00000000 00000000 00000000 00000040 ffffffff 00000000 00000000 00000000 00000000 > + RetIntrIn: 00000003 00000d05 00000000 00000000 00000000 00000000 00000040 ffffffff 00000000 00000000 00000000 00000000 > + ffffffff860011a784ce5ae2123763612891b1020100000400000000000000000000000000000000000000000000000000000000000000000000000000000000 >