Subject: Re: [PATCH v2] tools: usb: usbip: Add simple script to show how to
 setup vUDC
To: shuah@kernel.org, gregkh@linuxfoundation.org
References: <20161209171515.23491-1-k.opasiak@samsung.com>
 <CGME20161209214028epcas2p10a336554fd8d14b50b19b2cc5abaf407@epcas2p1.samsung.com>
 <0d70962e-4651-7774-b0ad-5c6e54ef164a@kernel.org>
Cc: valentina.manea.m@gmail.com, linux-kernel@vger.kernel.org,
        linux-usb@vger.kernel.org, Shuah Khan <shuahkh@osg.samsung.com>
From: Krzysztof Opasiak <k.opasiak@samsung.com>
Message-id: <c4ba4c5d-75a1-e14d-e3b3-07c2c59af125@samsung.com>
Date: Mon, 12 Dec 2016 13:05:41 +0100
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Hi,

On 12/09/2016 10:40 PM, Shuah Khan wrote:
> Hi Krzysztof,
> 
> Thanks for getting to this so quickly. Couple of comments below:
> 
> On 12/09/2016 10:15 AM, Krzysztof Opasiak wrote:
>> Add some simple script which creates a USB gadget using ConfigFS
>> and then exports it using vUDC.
>>
>> This may be useful for people who just started playing with
>> USB/IP and vUDC as it shows exact steps how to setup all stuff.
>>
>> Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
>> ---
>> Changes since v1:
>> - Fix terminology mistake (server instead of client)
>> ---
>>  tools/usb/usbip/vudc/vudc_server_example.sh | 100 ++++++++++++++++++++++++++++
>>  1 file changed, 100 insertions(+)
>>  create mode 100755 tools/usb/usbip/vudc/vudc_server_example.sh
> 
> Looks like it also includes client side, would it make sense to not name is server
> and call it vudc_export_example.sh?
> 

This script is intended to be run on a server side not on client or
both. It contains only couple of comments with suggestion what you
should do on a client side but any of those commands won't be executed
as the are all placed inside comments.

Moreover, our goal while developing vUDC was to make it compatible with
existing USB/IP infrastructure. That's why client side usage is pretty
the same for both vUDC and stub driver.

>>
>> diff --git a/tools/usb/usbip/vudc/vudc_server_example.sh b/tools/usb/usbip/vudc/vudc_server_example.sh
>> new file mode 100755
>> index 000000000000..9bd1fd58d592
>> --- /dev/null
>> +++ b/tools/usb/usbip/vudc/vudc_server_example.sh
>> @@ -0,0 +1,100 @@
>> +#!/bin/bash
>> +
>> +################################################################################
>> +# This is free and unencumbered software released into the public domain.
>> +#
>> +# Anyone is free to copy, modify, publish, use, compile, sell, or
>> +# distribute this software, either in source code form or as a compiled
>> +# binary, for any purpose, commercial or non-commercial, and by any
>> +# means.
>> +#
>> +# In jurisdictions that recognize copyright laws, the author or authors
>> +# of this software dedicate any and all copyright interest in the
>> +# software to the public domain. We make this dedication for the benefit
>> +# of the public at large and to the detriment of our heirs and
>> +# successors. We intend this dedication to be an overt act of
>> +# relinquishment in perpetuity of all present and future rights to this
>> +# software under copyright law.
>> +#
>> +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
>> +# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
>> +# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
>> +# IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
>> +# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
>> +# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
>> +# OTHER DEALINGS IN THE SOFTWARE.
>> +#
>> +# For more information, please refer to <http://unlicense.org/>
>> +################################################################################
> 
> This is the first file under usbip with a different license. Why did you chose
> this over GPL that is what is in all oter source files in this module?

The reason is very simple. It's just an *example* of vUDC usage, nothing
more. There is no new or useful functionality inside this script so I
don't see any reason to guard it with GPL license.

As far as I'm familiar with this license (please correct me if I'm
wrong), it simply allows everyone to use this script as their code base
and modify it to fit their needs and put them into products without
publishing the code. Which I think may be useful for some people.

> 
> Greg! Do you have any recommendation on this?
> 
>> +
>> +################################################################################
>> +# This is a sample script which shows how to use vUDC with ConfigFS gadgets
>> +################################################################################
>> +
>> +# Stop script on error
>> +set -e
>> +
>> +################################################################################
>> +# Create your USB gadget
>> +# You may use bare ConfigFS interface (as below)
>> +# or libusbgx or gt toool
>> +# Instead of ConfigFS gadgets you may use any of legacy gadgets.
>> +################################################################################
>> +CONFIGFS_MOUNT_POINT="/sys/kernel/config"
>> +GADGET_NAME="g1"
>> +ID_VENDOR="0x1d6b"
>> +ID_PRODUCT="0x0104"
>> +
>> +cd ${CONFIGFS_MOUNT_POINT}/usb_gadget
>> +# Create a new USB gadget
>> +mkdir ${GADGET_NAME}
>> +cd ${GADGET_NAME}
>> +
>> +# This gadget contains one function - ACM (serial port over USB)
>> +FUNC_DIR="functions/acm.ser0"
>> +mkdir ${FUNC_DIR}
>> +
>> +# Just one configuration
>> +mkdir configs/c.1
>> +ln -s ${FUNC_DIR} configs/c.1
>> +
>> +# Set our gadget identity
>> +echo ${ID_VENDOR} > idVendor
>> +echo ${ID_PRODUCT} > idProduct
>> +
>> +################################################################################
>> +# Load vudc-module if vudc is not available
>> +# You may change value of num param to get more than one vUDC instance
>> +################################################################################
>> +[[ -d /sys/class/udc/usbip-vudc.0 ]] || modprobe usbip-vudc num=1
>> +
>> +################################################################################
>> +# Bind gadget to our vUDC
>> +# By default we bind to first one but you may change this if you would like
>> +# to use more than one instance
>> +################################################################################
>> +echo "usbip-vudc.0" > UDC
>> +
>> +################################################################################
>> +# Let's now run our usbip daemon in a USB device mode
>> +################################################################################
>> +usbipd --device &
>> +
>> +################################################################################
>> +# Now your USB gadget is available using USB/IP protocol.
>> +# To check this you may try to list available devices:
>> +#
>> +# $ usbip list -r $SERVER_IP
>> +# Exportable USB devices
>> +# ======================
>> +# usbipd: info: request 0x8005(6): complete
>> +#  - 127.0.0.1
>> +# usbip-vudc.0: Linux Foundation : unknown product (1d6b:0104)
>> +#            : /sys/devices/platform/usbip-vudc.0
>> +#            : (Defined at Interface level) (00/00/00)
>> +#
>> +# To attach this device to your client you may use:
>> +#
> 
> Are you missing
> modprobe usbip-vhci
> 

Hmm... true. Usually I just simply build in this module in my test setup
and that's why I forgot about it;)

I'll add this in next version.

Best regards,
-- 
Krzysztof Opasiak
Samsung R&D Institute Poland
Samsung Electronics