ioctl (Input Output ConTroL) is a system call for device-specific I/O operations and other operations which cannot be expressed by regular system calls and it provides an interface through which an application can communicate directly with a device driver(or any other global kernel space variables). Applications can use the standard control codes or device-specific control codes to perform direct input and output operations.
Questions tagged [ioctl]
691 questions
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Linux IOCTL commands
Trying to implement IOCTL commands, and just encountered as below:
If _IO is for both read and write
than why should I consider _IOR and _IOW
any clue please ?
San
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IOCTL write crashing
I am trying to implement ioctl in kernel space to write some date into the register, I am getting a crash in cmd of ioctl.
Below is my code:
Kernel side:
static struct file_operations fops = {
.compat_ioctl = device_ioctl
};
int device_ioctl(struct…
San
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Sniffing IOCTL and serial port communication
I'm trying to reverse the protocol used by an early nineties logic analyzer an its PC software.
The device is connected via RS-232 (propietary wiring) and communicates with a DOS program, successfully running on DOSBOX.
I'm able to control the…
NeonMan
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Is it a good design to write the core main program in c++/shell script when the .so are in pure c?
I would like to write a core main server handles request by user (in shell like enviorment) and load dynamic libraries executes ioctls and some debugfs. The core server is in c++ and the loadable libs are written in c. Is it a good design?
What…
0x90
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IOCTL_ATA_PASS_THROUGH_DIRECT fails in Windows8
Here is my sample code:
PATA_PASS_THROUGH_DIRECT pATAPTD = NULL;
DWORD dataSize = sizeof(ATA_PASS_THROUGH_DIRECT) + 512;
pATAPTD = (PATA_PASS_THROUGH_DIRECT) VirtualAlloc(NULL, dataSize, MEM_COMMIT, PAGE_READWRITE);
ZeroMemory(pATAPTD, dataSize);…
Manvendra Kumar
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How can the Java InputStream function `available()` be implemented using the C language?
How can the Java InputStream function available() be implemented using the C language?
This function returns an estimate of the number of bytes which can be read from an InputStream without blocking by the next invocation of a method for that…
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ioctl failing "No such File or Directory"
I am trying to control a LED on a custom board. I have written the device driver and successfully loaded it. I have created a device file in /dev directory with the correct major number. Then I wrote a program in user plane to control the LED on the…
Neo
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48bit and 28bit ATA commands with ioctl
During sending ATA commands I found several classifications. For example, first one - we can divide the commands to Data-In, Data-Out and Non-Data commands. Another classification can be that there are 48bit commands and 28bit comands. First ones…
Rufi
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linux driver's function known/visible to application
In windows we create a function in a driver and we can call it from the application using dll as the middle man. What happens in linux? How can we create a custom function (ioctl) for example and call/ use it from the host application?
Any…
amanda
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Need of defining ioctl in linux kernel driver
i have started to learn ioctl
i got this example
http://tldp.org/LDP/lkmpg/2.6/html/x892.html
i got total working of ioctal but i am not getting why and where we need to define ioctal for our driver.?
For that example
Instead of calling…
Jeegar Patel
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Storage size of isn't known
This is part of an IOCTL switch case. I am getting the following error?
error: storage size of 'data' isn't known
error: 'mesg' undeclared (first use in this function)
case PASS_STRUCT:
struct mesg{
int pIDs[SIZE];
…
user340
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PInvoke DeviceIOControl for reading ISRC returns no data
I am using the sample Win32Functions Class by Idael Cardoso to interact with CD-Drive. I want to read the ISRC Code of a cd in the tray.
First some Code - this is the Win32Functions Class - I added the hopefully correct code for reading the…
sebastian87
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About the /proc file system
I am using a command in the proc file system which is the following
echo 0 > /proc/sys/net/ipv4/ip_forward
Note: I don't want to know the basic of the command written above, I want what all happens when it goes inside the kernel. As, I want to…
Invictus
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Passing a struct via IOCTL to kernel-mode driver
I'm trying to pass several distinct pieces of information to a kernel-mode driver from a user-mode application in Windows. I won't pretend to know fully what I'm doing, so if I have any fundamental misconceptions, clarification would be greatly…
wanovak
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non root access to ioctl for WIFI scan
I'm working on implementing iwlist python version. Here is a description of how iwlist works on Linux OS How does iwlist() command scans the wireless networks? what it does is to scan all nearby wifi access points, show a list of their ESSID, MAC…
Yanyan
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