2. Compilation And Installation Instructions

Dependencies

To successfully compile libntoh you need the following packages:

• gcc
• make
• cmake
• pkg-config
• libpthread-dev

Debian-like OS:

$ sudo apt-get install cmake libpthread-dev gcc make build-essential pkg-config

If you want to generate the source code documentation, you will also need doxygen:

$ sudo apt-get install doxygen

Note: pkg-config isn't really needed but it helps. (See "ntohexample" compilation)

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Libntoh compilation and installation instructions

Once you have downloaded the source code, go into "libntoh" directory and type the following commands to manually compile the library:

$ mkdir build
$ cd build
$ cmake ..
$ make
$ sudo make install

The above commands will install libntoh under "/usr/local" prefix. If you want it to be installed in a different prefix (like /usr), you can do it by defining CMAKE_INSTALL_PREFIX when calling to cmake:

$ cmake .. -DCMAKE_INSTALL_PREFIX=/usr

There is also a script to help you to compile the library:

$ cd libntoh/src
../src$ ./build.sh
[i] pkg-config found: /usr/bin/pkg-config
[i] cmake found: /usr/bin/cmake
[i] make found: /usr/bin/make
[i] PKG_CONFIG_PATH set to: /usr/local/lib/pkgconfig

-- The C compiler identification is GNU 4.8.4
-- The CXX compiler identification is GNU 4.8.4
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Looking for include file pthread.h
-- Looking for include file pthread.h - found
-- Looking for pthread_create
-- Looking for pthread_create - not found
-- Looking for pthread_create in pthreads
-- Looking for pthread_create in pthreads - not found
-- Looking for pthread_create in pthread
-- Looking for pthread_create in pthread - found
-- Found Threads: TRUE  
-- Configuring done
-- Generating done
-- Build files have been written to: /tmp/libntoh/src/build
Scanning dependencies of target ntoh
[ 16%] Building C object CMakeFiles/ntoh.dir/libntoh.c.o
[ 33%] Building C object CMakeFiles/ntoh.dir/tcpreassembly.c.o
[ 50%] Building C object CMakeFiles/ntoh.dir/ipv4defrag.c.o
[ 66%] Building C object CMakeFiles/ntoh.dir/ipv6defrag.c.o
[ 83%] Building C object CMakeFiles/ntoh.dir/common.c.o
[100%] Building C object CMakeFiles/ntoh.dir/sfhash.c.o
Linking C shared library libntoh.so
[100%] Built target ntoh
Do you want to perform the installation? [y/n]: y
[sudo] password for chema: 
[100%] Built target ntoh
Install the project...
-- Install configuration: "Release"
-- Installing: /usr/local/lib/libntoh.so
-- Installing: /usr/local/include/libntoh/libntoh.h
-- Installing: /usr/local/include/libntoh/tcpreassembly.h
-- Installing: /usr/local/include/libntoh/sfhash.h
-- Installing: /usr/local/include/libntoh/ipv4defrag.h
-- Installing: /usr/local/include/libntoh/ipv6defrag.h
-- Installing: /usr/local/include/libntoh/common.h
-- Installing: /usr/local/lib/pkgconfig/ntoh.pc
$

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Libntoh Examples

You can find a working source code example for each supported protocol in "examples" folder:

libntoh$ ls examples/ -R
examples/:
c

examples/c:
ipv4  ipv6  tcp_ipv4  tcp_ipv6

examples/c/ipv4:
build.sh  CMakeLists.txt  example.c

examples/c/ipv6:
build.sh  CMakeLists.txt  example.c

examples/c/tcp_ipv4:
build.sh  CMakeLists.txt  example.c

examples/c/tcp_ipv6:
build.sh  CMakeLists.txt  example.c

The default installation prefix for libntoh is "/usr/local", so if you plan to link against libntoh using pkg-config remember to add "/usr/local/lib/pkgconfig" to PKG_CONFIG_PATH:

$ export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig
$ pkg-config --libs --cflags ntoh -I/usr/local/include/libntoh  -L/usr/local/lib -lntoh

On the other hand you can change the installation prefix by defining CMAKE_INSTALL_PREFIX:

$ cmake ../ -DCMAKE_INSTALL_PREFIX=/usr

So the new installation prefix will be "/usr"

For more information, refer to the wiki page.

TCP/IPv4 Example Output:

$ sudo ./ntohexample 
###########################
#     libntoh Example     #
# ----------------------- #
# Written by Chema Garcia #
# ----------------------- #
#  http://safetybits.net  #
#   [email protected]  #
###########################

[i] libntoh version: 0.4a

[+] Usage: ./ntohexample <options>

+ Options:
	  -i | --iface <val> -----> Interface to read packets from
	  -f | --file <val> ------> File path to read packets from
 	  -F | --filter <val> ----> Capture filter (default: "ip and tcp")
	  -c | --client ----------> Receive client data only
	  -s | --server ----------> Receive server data only

$