I am writing a mini-filter code for USB (Flash Drives) for blocking i.e (Access Denied).So, could someone help me out, how to detect or block USB or what methods to use in passThrough WDK sample code for USB detection and USB blocking?
I am trying to use *IOCTL_STORAGE_QUERY_PROPERTY in PFLT_INSTANCE_SETUP_CALLBACK*. Am i on right path?? if yes then how to use IOCTL_STORAGE_QUERY_PROPERTY in PFLT_INSTANCE_SETUP_CALLBACK???
After 3 months of work I have finally achieved blocking.
Though I can't give direct code here.
But following link might help.
PassThrough Development
GitHub Link
One way could be to get the device object using FltGetDiskDeviceObject and then check for FILE_REMOVABLE_MEDIA flag in device_object->Characteristics. Once you get to know about the device type, then you can block or allow the required operations (that you need to register with FLT_OPERATION_REGISTRATION).
Related
I am working on a CX3 chip from cypress which has a USB 3.0 connectivity. I need to enumerate the USB to work as a UVC class(video class) and as a serial port simultaneously.
I have seen the USB documents related to the same but those don't clearly explain about how to write one.
The CX3 SDK provides help to generate the USB descriptors for a UVC class but that doesn't give info about how to add the COM port features into it.
So my query is how do you write the descriptor for the same.
Thanks in advance.
Refer to the attached project in this knowledge base article from Cypress - "Using CyU3PDebugPrint API to Send Debug Messages over USB-CDC Interface from FX3 Firmware – KBA231478"
This is a modified version on AN75779. You can compare this project with the original AN75779 appnote firmware available here to see the additions done for adding USB-CDC support in a UVC device.
Hope this helps!
Let's say I have a webcam, and I installed the device driver for this webcam in my Linux OS, now a device file will be created for the device driver (for example: /dev/video0).
Now say I want to create a program in C that wants to access this webcam. How can my program access the device driver for the webcam, should my program use the device file (/dev/video0) to access the device driver, or is there another way?
You asked a general question, and then gave a specific example. I'll try to address both.
When you load a driver, the way to communicate with it from user space is by whatever means this driver defined. Typically, this is through a /dev device created for the driver. If that's the case, yes, that's the only way to communicate with it.
This is not universally true. Many drivers also have entries under the /sys sysfs pseudo file system, and some aspects can be modified through there. In fact, there are whole classes of drivers that are only accessible through the /sys fs. Prominent examples are GPIO and Led devices, that can be turned on and off via access to /sys/class/gpio and similar paths.
Another option, considered deprecated but still sometimes used, is to use the /proc pseudo file system. Again, this is up to the driver to define its communication method. As the user, you will have to follow whatever protocol the driver defined.
Also, some drivers don't have any file system presence at all. The most obvious standard example are network interfaces. The only way to communicate with them is via the networking system calls.
In the particular example you provided, you talked about a video camera that appears as /dev/video0. Such a camera is, usually, a Video4Linux (or v4l) camera, and those are accessed via their character devices.
With that said, the protocol for communicating with the camera might have wrappers that makes life easier. If you open the actual device, you might have to implement a rather complicated handshake with it. Instead, you can use the v4l library to wrap the details of the access.
Make no mistake. You're still talking to the character device in /dev. It's just that it's not your code that does it, but the library's.
I'm doing some experiments with lwIP on a small, embedded device. There are some examples that come with lwIP but they do not help me. What I want to implement is a server (using wlIP) that accepts a connection, reads several commands, sends several answers to the connected client and closes only when the connection is interrupted or a special close-command is sent.
So somehow similar to a telnet-server.
Is there an example for lwIP available that demonstrates this behaviour?
Thanks!
I know this is an old question - but I found it when looking for something similar!
If you look in the lwip contrib directory (http://download.savannah.gnu.org/releases/lwip/) there are some example applications - including a tcp (and udp) echo server.
You don't say what device you are using or whether or not you are using an RTOS, so it is hard to provide example code. However, if you are not using an RTOS I would highly recommend you start! My experience of using the lwip raw api (without an rtos) is that it is difficult to read data from the outside world (e.g. using interrupts) without things falling over.
HTH,
Alex
I just read in a few articles that we need some kind of special drivers for parallel port to access it through C as in win xp and 7 we cannot access them directly.
Can someone help me do this?
Correct. You need driver to access ports. If your purpose is to just read write data to ports for experimentation, you can use the sample(WinDDK\7600.16385.1\src\general\portio) provided with WDK to experiment with ports. The sample provides driver that you can build and install
and gives a sample user mode program describing how to use the Ioctls to achieve the desired port IO.
I have just managed to write my first windows driver (havent registered it yet- but i managed to get the things created!).
I wondered if someone can give me a high overview of how I could achieve the following:
I would like to write a driver which will implement some behaviour when a network packet is received by the computer, before windows does what it does with the packet, i'd like to take this data and output it to the console of a C or C++ program.
Lets assume I have a C/C++ program written, which has a console. How does the C/C++ program interact with the driver I wrote which is hooking the network activity? Is it simply some C code which calls my drivers, the function returns the data as an object and then I can use that object to display in the console?
Thank you in advance for any possible replies
You don't need a driver for this task. Use packet sniffer library like PCap (actually you'll need WinPCap). It's really simple to capture packets and print them to console.
Alternative way is raw socket. But desktop Windows (as opposite to Windows Server) limits raw socket functionality.
If you really want a driver, or have a requirement to manipulate or filter packets before they hit the windows network stack you need to look into filter drivers.
This filter driver can then expose a device file on which your user space application can then read/write. The windows DDK contains examples.