syscall_number

Description

With this little script you can search for Intel x86 Linux system call names and get the system call number as a result. There are websites like https://filippo.io/linux-syscall-table/ or https://www.informatik.htw-dresden.de/~beck/ASM/syscall_list.html but who wants to google all the time when he/she can have a command-line tool that works for 32bit and 64bit!

Requirements

gcc with 32bit support

Ubuntu:

sudo apt-get install gcc gcc-multilib

Fedora:

sudo dnf install gcc glibc-devel.i686

Installation

Make sure you have a Python version >= 3.6! (check with python3 --version)

Create and activate a virtual environment:

python3 -m venv venv
source ./venv/bin/activate

This virtual environment must then be active everytime you want to use syscall_number.

python3 -m pip install git+https://github.com/martinclauss/syscall_number.git

Now you can run the command without the .py extension from everywhere:

syscall_number --help

Updates

You won't get new features / bug fixes automatically but you can easily update:

python3 -m pip install --upgrade git+https://github.com/martinclauss/syscall_number.git

Uninstallation

python3 -m pip uninstall syscall_number

Usage

# the first time the command takes a bit longer since it builds a cache for all system calls
# query the system call (-s) read for 32bit (-b 32):
syscall_number -s read -b 32

# this should run a lot faster
# query the system call (-s) write for 64bit (-b 64):
syscall_number -s write -b 64

# reverse lookup is also possible with decimal and hexadecimal numbers
syscall_number -n 11 -b 32
syscall_number -n 0xb -b 32 

# this lists all (-a) 32bit (-b 32) system calls:
syscall_number -a -b 32

# and this lists all (-a) 64bit (-b 64) system calls:
syscall_number -a -b 64

# reverse search is also possible with grep:
syscall_number -a -b 32 | grep read

# if you just want the system call number without any additional text use -q:
syscall_number -s connect -b 32 -q

# or in a more complex scenario with pwntools' asm script (http://docs.pwntools.com/en/stable/asm.html)
echo "mov eax, $(syscall_number -s exit -b 32 -q); mov ebx, 42; int 0x80" | asm

# additionally show an excerpt of the man page for the system call with -m:
syscall_number -s read -b 32 -m

Alternatives

pwntools also provides a similar but more complex method with the syscall() function: 32bit and 64bit.

Contribution

Pull Requests are welcome! :)

Thanks

@tbehner