412 строки
30 KiB
Plaintext
412 строки
30 KiB
Plaintext
===============
|
|
USB/IP protocol
|
|
===============
|
|
|
|
PRELIMINARY DRAFT, MAY CONTAIN MISTAKES!
|
|
28 Jun 2011
|
|
|
|
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 device runs on the client machine.
|
|
|
|
The client may ask for the list of the exported USB devices. To get the list the
|
|
client opens a TCP/IP connection towards the server, and sends an OP_REQ_DEVLIST
|
|
packet on top of the TCP/IP connection (so the actual OP_REQ_DEVLIST may be sent
|
|
in one or more pieces at the low level transport layer). The server sends back
|
|
the OP_REP_DEVLIST packet which lists the exported USB devices. Finally the
|
|
TCP/IP connection is closed.
|
|
|
|
::
|
|
|
|
virtual host controller usb host
|
|
"client" "server"
|
|
(imports USB devices) (exports USB devices)
|
|
| |
|
|
| OP_REQ_DEVLIST |
|
|
| ----------------------------------------------> |
|
|
| |
|
|
| OP_REP_DEVLIST |
|
|
| <---------------------------------------------- |
|
|
| |
|
|
|
|
Once the client knows the list of exported USB devices it may decide to use one
|
|
of them. First the client opens a TCP/IP connection towards the server and
|
|
sends an OP_REQ_IMPORT packet. The server replies with OP_REP_IMPORT. If the
|
|
import was successful the TCP/IP connection remains open and will be used
|
|
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.
|
|
|
|
::
|
|
|
|
virtual host controller usb host
|
|
"client" "server"
|
|
(imports USB devices) (exports USB devices)
|
|
| |
|
|
| OP_REQ_IMPORT |
|
|
| ----------------------------------------------> |
|
|
| |
|
|
| OP_REP_IMPORT |
|
|
| <---------------------------------------------- |
|
|
| |
|
|
| |
|
|
| USBIP_CMD_SUBMIT(seqnum = n) |
|
|
| ----------------------------------------------> |
|
|
| |
|
|
| USBIP_RET_SUBMIT(seqnum = n) |
|
|
| <---------------------------------------------- |
|
|
| . |
|
|
| : |
|
|
| |
|
|
| USBIP_CMD_SUBMIT(seqnum = m) |
|
|
| ----------------------------------------------> |
|
|
| |
|
|
| USBIP_CMD_SUBMIT(seqnum = m+1) |
|
|
| ----------------------------------------------> |
|
|
| |
|
|
| USBIP_CMD_SUBMIT(seqnum = m+2) |
|
|
| ----------------------------------------------> |
|
|
| |
|
|
| USBIP_RET_SUBMIT(seqnum = m) |
|
|
| <---------------------------------------------- |
|
|
| |
|
|
| USBIP_CMD_SUBMIT(seqnum = m+3) |
|
|
| ----------------------------------------------> |
|
|
| |
|
|
| USBIP_RET_SUBMIT(seqnum = m+1) |
|
|
| <---------------------------------------------- |
|
|
| |
|
|
| USBIP_CMD_SUBMIT(seqnum = m+4) |
|
|
| ----------------------------------------------> |
|
|
| |
|
|
| USBIP_RET_SUBMIT(seqnum = m+2) |
|
|
| <---------------------------------------------- |
|
|
| . |
|
|
| : |
|
|
| |
|
|
| USBIP_CMD_UNLINK |
|
|
| ----------------------------------------------> |
|
|
| |
|
|
| USBIP_RET_UNLINK |
|
|
| <---------------------------------------------- |
|
|
| |
|
|
|
|
The fields are in network (big endian) byte order meaning that the most significant
|
|
byte (MSB) is stored at the lowest address.
|
|
|
|
|
|
OP_REQ_DEVLIST:
|
|
Retrieve the list of exported USB devices.
|
|
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| Offset | Length | Value | Description |
|
|
+===========+========+============+===================================================+
|
|
| 0 | 2 | 0x0100 | Binary-coded decimal USBIP version number: v1.0.0 |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 2 | 2 | 0x8005 | Command code: Retrieve the list of exported USB |
|
|
| | | | devices. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 4 | 4 | 0x00000000 | Status: unused, shall be set to 0 |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
|
|
OP_REP_DEVLIST:
|
|
Reply with the list of exported USB devices.
|
|
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| Offset | Length | Value | Description |
|
|
+===========+========+============+===================================================+
|
|
| 0 | 2 | 0x0100 | Binary-coded decimal USBIP version number: v1.0.0.|
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 2 | 2 | 0x0005 | Reply code: The list of exported USB devices. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 4 | 4 | 0x00000000 | Status: 0 for OK |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 8 | 4 | n | Number of exported devices: 0 means no exported |
|
|
| | | | devices. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x0C | | | From now on the exported n devices are described, |
|
|
| | | | if any. If no devices are exported the message |
|
|
| | | | ends with the previous "number of exported |
|
|
| | | | devices" field. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| | 256 | | path: Path of the device on the host exporting the|
|
|
| | | | USB device, string closed with zero byte, e.g. |
|
|
| | | | "/sys/devices/pci0000:00/0000:00:1d.1/usb3/3-2" |
|
|
| | | | The unused bytes shall be filled with zero |
|
|
| | | | bytes. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x10C | 32 | | busid: Bus ID of the exported device, string |
|
|
| | | | closed with zero byte, e.g. "3-2". The unused |
|
|
| | | | bytes shall be filled with zero bytes. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x12C | 4 | | busnum |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x130 | 4 | | devnum |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x134 | 4 | | speed |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x138 | 2 | | idVendor |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x13A | 2 | | idProduct |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x13C | 2 | | bcdDevice |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x13E | 1 | | bDeviceClass |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x13F | 1 | | bDeviceSubClass |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x140 | 1 | | bDeviceProtocol |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x141 | 1 | | bConfigurationValue |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x142 | 1 | | bNumConfigurations |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x143 | 1 | | bNumInterfaces |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x144 | | m_0 | From now on each interface is described, all |
|
|
| | | | together bNumInterfaces times, with the |
|
|
| | | | the following 4 fields: |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| | 1 | | bInterfaceClass |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x145 | 1 | | bInterfaceSubClass |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x146 | 1 | | bInterfaceProtocol |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 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. |
|
|
| m_(i-1)*4 | | | |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
|
|
OP_REQ_IMPORT:
|
|
Request to import (attach) a remote USB device.
|
|
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| Offset | Length | Value | Description |
|
|
+===========+========+============+===================================================+
|
|
| 0 | 2 | 0x0100 | Binary-coded decimal USBIP version number: v1.0.0 |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 2 | 2 | 0x8003 | Command code: import a remote USB device. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 4 | 4 | 0x00000000 | Status: unused, shall be set to 0 |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 8 | 32 | | busid: the busid of the exported device on the |
|
|
| | | | remote host. The possible values are taken |
|
|
| | | | from the message field OP_REP_DEVLIST.busid. |
|
|
| | | | A string closed with zero, the unused bytes |
|
|
| | | | shall be filled with zeros. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
|
|
OP_REP_IMPORT:
|
|
Reply to import (attach) a remote USB device.
|
|
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| Offset | Length | Value | Description |
|
|
+===========+========+============+===================================================+
|
|
| 0 | 2 | 0x0100 | Binary-coded decimal USBIP version number: v1.0.0 |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 2 | 2 | 0x0003 | Reply code: Reply to import. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 4 | 4 | 0x00000000 | Status: |
|
|
| | | | |
|
|
| | | | - 0 for OK |
|
|
| | | | - 1 for error |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 8 | | | From now on comes the details of the imported |
|
|
| | | | device, if the previous status field was OK (0), |
|
|
| | | | otherwise the reply ends with the status field. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| | 256 | | path: Path of the device on the host exporting the|
|
|
| | | | USB device, string closed with zero byte, e.g. |
|
|
| | | | "/sys/devices/pci0000:00/0000:00:1d.1/usb3/3-2" |
|
|
| | | | The unused bytes shall be filled with zero |
|
|
| | | | bytes. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x108 | 32 | | busid: Bus ID of the exported device, string |
|
|
| | | | closed with zero byte, e.g. "3-2". The unused |
|
|
| | | | bytes shall be filled with zero bytes. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x128 | 4 | | busnum |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x12C | 4 | | devnum |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x130 | 4 | | speed |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x134 | 2 | | idVendor |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x136 | 2 | | idProduct |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x138 | 2 | | bcdDevice |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x139 | 1 | | bDeviceClass |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x13A | 1 | | bDeviceSubClass |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x13B | 1 | | bDeviceProtocol |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x13C | 1 | | bConfigurationValue |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x13D | 1 | | bNumConfigurations |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 0x13E | 1 | | bNumInterfaces |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
|
|
USBIP_CMD_SUBMIT:
|
|
Submit an URB
|
|
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
| 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. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
|
|
|
|
+-------------------------+------------+---------+-----------+----------+-------------+
|
|
| 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_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. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
|
|
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. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|
|
|
|
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. |
|
|
+-----------+--------+------------+---------------------------------------------------+
|