I am working at an OS independent file manager, in C. I managed to copy files, links and directories, but I am not sure how to copy devices. I would appreciate any help.
To create a device file, use the mknod(2) syscall. The struct stat structure will give you the major and minor device numbers for an existing device in st_rdev.
Having said that, there is little value in "copying" a device because a device doesn't contain anything useful. The major and minor numbers are specific to the OS on which they exist.
It's not really a useful feature, IMHO. tar(1) needs to be able to do it as part of backing up a system, and setup programs need to be able to create them for you when setting up your system, but few people need to deal directly with device files these days.
Also, modern Linux systems are going to dynamic device files, created on the fly. You plug in a device and the device files appear; you unplug it and they disappear. There is really no use in being able to copy these dynamic files.
dd is your friend (man dd)
dd if=/dev/sda1 of=/some_file_or_equally_sized_partition bs=8192
if you want to copy the device-file itself, do this:
cp -p device-filename new-filename
e.g.:
cp -p /dev/sda1 /tmp/sda1
those are both equivalent device files, and can be used to access the device.
If you're want to do this from C, use mknod() .. see "man 2 mknod"
This might be useful
cp -dpR devices /destination_directory
cp -dpR console /mnt/dev
You don't. Just filter them out of the view such that it can't be done.
Use the stat function to determine the file type.
Check if you've the udev package, if you do, chances are that devices are generated on the fly, from the package description:
udev - rule-based device node and kernel event manager
udev is a collection of tools and a daemon to manage events received from the
kernel and deal with them in user-space. Primarily this involves creating and
removing device nodes in /dev when hardware is discovered or removed from the
system.
Events are received via kernel netlink messaged and processed according to
rules in /etc/udev/rules.d and /lib/udev/rules.d, altering the name of the
device node, creating additional symlinks or calling other tools and programs
including those to load kernel modules and initialise the device.
Related
Judging by the lib_v1.0.2 library, access to the file system is implemented in Toit. May be can give some simple examples, which would include:
Create a file,
Writing data to file,
Reading data from a file,
Deleting a file,
Is there support for folders, and if so, what is the nesting level and how to get a list of files in the folder?
Update 2022-12-20: the host package's filesystem functionality (host.file and host.directory) is now supported for sdcards.
The filesystem libraries are not supported on ESP32 devices. They were implemented for host machines (like Linux), but that version isn't released.
The libraries will likely move soon and then not be accessible anymore.
If you want to store data on the device, maybe the device flashstore works for you:
import device
main:
store := device.FlashStore
store.set "key" "data"
I want to upgrade my systems in the field using the uboot FIT images.
My system is a custom firmware, booted by uboot. So far the FIT filesystem works very good. It provides a shasum verified upload. I am using uboot scripts to update stuff on the target.
One intriguing type defined in uboot docs is type "filesystem". The actual content could be several things, like maybe tar'ed bunch of files, or an actual collection of separate individual files in one chunk in the FIT.
In another FIT question, Tom Rini implied that a filesystem is really just a binary blob. What goes into it is my problem and that uboot could then just mmc write ... or usb write ... to create the new filesystem on some partition. Is this really the case?
How can I build a filesystem (say FAT), on a host build computer for packaging with FIT?
Thanks, Steve
The creation of a filesystem image will depend on the filesystem itself. In many cases, build systems such as OpenEmbedded or buildroot can help you here as they will create the images for you.
how to get harddrive serial number(not the volume # wich change at each reinstall of windows) in C or asm, without wmi (cause wmi required admin right). Any clue would be helpfull cause right now i found nothing on web in C without wmi, in dayss of searching... Thank you.
EDIT : For windows system
Please try my open source tool, DiskId32, which also has the source code at http://www.winsim.com/diskid32/diskid32.html . I only have an Win32 version at this time. Maybe some day I will add a Win64 version.
Hard drive serial number and other information about the harddrive like firmware version, etc. can only be obtained using SMART as far as I know and that requires special ioctls to the the block device node (/dev/sda or /dev/sdb) which is usually not available to a regular user.
I know there is a tool called smartctl which does exactly this:
sudo smartctl -i /dev/sda
Similar tools exist (hdparm, lshw, etc.) as well.
As far as trying to figure it out this info without being a privileged user, it might be possible only if it is exposed via /proc or /sys which I highly doubt is being done in the current SATA block device drivers.
I am new to device driver programming. I've followed the available tutorials on the web which has provided helpful information to get started. However now I have embarked on a new project where the exclusive goal is to search for functions which have been hooked by malware or keyloggers. So I think I have sorted out what I need to accomplish this though I still need to be able to locate the load address of the system dll's (i.e. kernel32.dll, user32.dll and the like) that are already loaded in memory. I need the load address so that I can parse their PE to get to the export and import sections. Furthermore adding the load address to the file size will give me a address range to cross reference the addresses of the export functions no ? Cross referencing the the IMPORT address will be a little more involved but it can be done according to my estimates. I thought that building a kernel mode driver would be the right way to go since accessing memory outside the kernel driver's address range would not be an issue for the driver as opposed to a user mode app. How else will I be able to access the addresses located in the EAT and IAT of the target dll ? I know there exist a user mode API that can provide the load address mainly being GetModuleHandle but I would like to find the equivalent in kernel mode. I could write a user mode application that could relay this information to the driver but prefer that this all be done in kernel mode if possible. Any suggestions or comments would be most welcome.
Thanks in advance
Victor
p.s This post has been edited for more clarity. Hopefully it will make it more clear as what I am trying to accomplish.
This is probably not a very good idea to do in kernel mode. When are you going to actually do this and guarantee the process is in a state where you could walk the IAT?
What if the process is in the middle of loading a DLL? If you're executing in-thread (i.e. from a syscall or device IOCTL), what if other threads are executing too? Doing this when you're not the OS is a very difficult proposition to correctly do, and it's very easy to destabilize your customers' machines (hell, it's reasonably hard to do even if you are the OS)
Take a look at LdrGetProcedureAddress and the rest of the gang.
Edit:
MmGetSystemRoutineAddress might also be helpful.
Just wanted to thank everyone for their contribution. I did manage to some further research and discovered that there is a kernel mode API called PsLoadImageNotifyCallback that is able to find the base addresss of any process.
I'm programming in C with Anjuta a small application with libusb library.
libusb has need the write rights for some purpose.
This argoment was already dealt in this topic: "Get access to USB device on Linux (libusb-1.0)?".
Maybe the topic solution work fine (I'm not tried yet) but i would like my application access to all usb device and not to the specific one.
i've tried to set a suid bit at a libusb-1.0.so file which have a root owner but libusbopen function, for example, answer "libusb requires write access to USB device nodes" again.
I don't wont to build the entire anjuta project as root user but so far this is the only solution for this libusb-1.0 issue.
Is there a solution for get write access to inode of a general usb device (for example hot plug pendrive) without modify udev behavior?
I have found a workaround. Maybe it's not good but it seems to work well.
I have added a permission rules file (020_permissions.rules) in the udev configuration directory (/etc/udev/rules.d) where the unique rule is which Unix group should own all the USB device nodes.
The file content is:
SUBSYSTEM=="usb", GROUP=="group to belong my user"
I hope this helps you if you have a similar libusb issue.