# Installing, Building, and Running chiTCP¶

The source code for chiTCP can be found in the following GitHub repository:

To work on the assignments, all you need to do is clone this repository. However, please note that your instructor may give you more specific instructions on how to get the chiTCP code.

## Software Requirements¶

chiTCP has a number of software requirements. If you are doing the chiTCP assignments as part of a class, it’s likely that this software is already installed on your school’s computers. If so, you can skip this section, unless you want to run chiTCP on your own computer. Please note that, so far, chiTCP has only been tested on Linux systems. At this point, we cannot guarantee that chiTCP will build and run smoothly on Mac systems.

### CMake¶

Building the chiTCP code requires the CMake (version 3.5.1 or higher)

### protobuf and protobuf-c¶

chiTCP requires protobuf 2.6.1 and protobuf-c 1.x (it may work with protobuf 3.x, but we have not tested it with that version). If these versions are not available as packages on your operating system, you will need to install them from source. You can find the appropriate tarballs at https://github.com/google/protobuf and https://github.com/protobuf-c/protobuf-c.

On most UNIX systems, you should be able to install protobuf by running the following:

wget https://github.com/google/protobuf/releases/download/v2.6.1/protobuf-2.6.1.tar.gz
tar xvzf protobuf-2.6.1.tar.gz
cd protobuf-2.6.1/
./configure --prefix=/usr
make
sudo make install


And protobuf-c by running the following:

wget https://github.com/protobuf-c/protobuf-c/releases/download/v1.2.1/protobuf-c-1.2.1.tar.gz
tar xvzf protobuf-c-1.2.1.tar.gz
cd protobuf-c-1.2.1/
./configure --prefix=/usr
make
sudo make install


Please note the use of --prefix=/usr. If you omit this parameter, the libraries will be installed in /usr/local/lib, which can cause problems on some systems. If you encounter an error like this:

error while loading shared libraries: libprotoc.so.N: cannot open shared object file:
No such file or directory


you will need to explicitly add /usr/local/lib (or any alternate prefix you specify when installing) to the LD_LIBRARY_PATH environment variable:

export LD_LIBRARY_PATH=\\$LD_LIBRARY_PATH:/usr/local/lib


### Criterion Unit Testing Framework¶

chiTCP uses the Criterion unit testing framework to run its unit tests. Installation instructions can be found here. Please note that you must install version 2.3.0-1 or later.

## Building¶

The first time you download the chiTCP code to your machine, you must run the following from the root of the chiTCP code tree:

mkdir build
cd build
cmake ..


This will verify whether you have the necessary tools to build chiTCP and will also generate a number of files required to build chiTCP. You should only need to rerun the above commands if you modify CMake’s CMakeLists.txt (which you should not need to do as part of this project).

Once you have done this, simply run make inside the build directory to build chiTCP. This will generate the chiTCP daemon (chitcpd), some sample programs, as well as the test executables (all starting with test-). Take into account that you must run these programs from inside the build directory.

By default, make will only print the names of the files it is building. To enable a more verbose output (including the exact commands that make is running during the build process), just run make like this:

make VERBOSE=1


## Running¶

To run the chiTCP daemon, just run the following:

./chitcpd -vv


You should see the following output:

[16:57:26.446948795]    INFO          chitcpd chitcpd running. UNIX socket: /tmp/chitcpd.socket. TCP socket: 23300


Take into account that you won’t be able to do much with chitcpd until you’ve implemented the tcp.c file. We do, however, provide a number of mechanisms for you to test your implementation. These are described in Testing your Implementation

By default, chitcpd listens on TCP port 23300. If you are running chitcpd on a shared machine, this default value will likely conflict with other users running on that same machine. To specify an alternate port, you need to set the following environment variable on every terminal in which you are running chitcp programs (including chitcpd and any application that uses the chisocket library):

export CHITCPD_PORT=30287  # Substitute for a different number


chitcpd also creates a UNIX socket on /tmp/chitcpd.socket.USER (where USER is your UNIX username). It is unlikely that this will conflict with other users but, if you need to specify an alternate location and name for this UNIX socket, just set the CHITCPD_SOCK environment variable to the absolute path of the UNIX socket (and remember to do this on every terminal in which you are running chitcp programs)