tinytcp

tinytcp is designed primarily for use in an embedded environment. It is designed for simplicity and deterministic memory usage. All memory used is preallocated in static arrays.

Building

Building uses CMake.

Windows

Windows build has been tested on Windows 10 using the community version of Visual Studio 2015.

mkdir myproject
cd myproject
git clone https://github.com/rkimball/tinytcp.git
mkdir build
cd build
cmake -G "Visual Studio 14 2015" ..\tinytcp

This generates tinytcp.sln solution file.

• The Windows build uses WinPcap that you will need to download and install before running.
• To view the tinytcp test_app web page you will need to point a browser at the IPv4 address that test_app gets from DHCP. This is printed out when the app is run. You will also need to use a browser on a different computer that the one running test_app. When run, test_app will produce output like this

sending discover
discover sent
DHCP Send type 3
DHCP got address 192.168.1.23

so you will point your browser at http://192.168.1.23 in this example

Linux

Linux build has been tested on Ubuntu 22.04.

• To run on a windows Hyper-V ubuntu installation you need to enable MAC address spoofing on the VM's network adapter. To do this go to the VM's settings page, expand the Network Adapter node in the left panel, and select Advanced Features. Now, in the panel on the right check the Enable MAC address spoofing checkbox and select Apply to apply the setting.

mkdir myproject
cd myproject
git clone https://github.com/rkimball/tinytcp.git
mkdir build
cd build
cmake ../tinytcp
make

• Because the tinytcp test app uses a promiscuous socket in order to read/write Layer 2 Ethernet frames, the test app must be run with elevated privileges.

sudo test_app/test_app

• To view the tinytcp test_app web page you will need to point a browser at the IPv4 address that test_app gets from DHCP. This is printed out when the app is run. You will also need to use a browser on a different computer that the one running test_app. When run, test_app will produce output like this:

sending discover
discover sent
DHCP Send type 3
DHCP got address 192.168.1.23

so you will point your browser at http://192.168.1.23 in this example

Usage

The protocol stack has three main functions required

1. NetworkInterface.RxData - expects a Layer 2 Ethernet frame as input
2. NetworkInterface.TxData - outputs a Layer 2 Ethernet frame
3. ProtocolTCP::Tick()

Doing something useful:

ListenerConnection = ProtocolTCP::NewServer( port );
while( 1 )
{
   connection = ListenerConnection->Listen();

   // Spawn off a thread to handle this connection
   page = (HTTPPage*)PagePool.Get();
   if( page )
   {
      page->Initialize( connection );
      page->Thread.Create( ConnectionHandlerEntry, "Page", 1024, 100, page );
   }
   else
   {
      printf( "Error: Out of pages\\n" );
   }
}

TCP Library Size

All of the memory used is statically allocated and so a buffer such as transmit or receive will show up in the bss section. The transmit and receive buffers are configurable and current set to 20 each of size 512 bytes. These buffers are defined in ProtocolMACEthernet, which explains it's large bss.

   text    data     bss     dec     hex filename
   1249       8      48    1305     519 Address.cpp.o (ex build/tcpStack/libtcpStack.a)
      0       0       0       0       0 DataBuffer.cpp.o (ex build/tcpStack/libtcpStack.a)
    312       0       0     312     138 FCS.cpp.o (ex build/tcpStack/libtcpStack.a)
    164       0       0     164      a4 NetworkInterface.cpp.o (ex build/tcpStack/libtcpStack.a)
   3524       8     600    4132    1024 ProtocolARP.cpp.o (ex build/tcpStack/libtcpStack.a)
   5018       4       0    5022    139e ProtocolDHCP.cpp.o (ex build/tcpStack/libtcpStack.a)
    360       0       0     360     168 ProtocolICMP.cpp.o (ex build/tcpStack/libtcpStack.a)
   1665       8     320    1993     7c9 ProtocolIP.cpp.o (ex build/tcpStack/libtcpStack.a)
   2176       8   22232   24416    5f60 ProtocolMACEthernet.cpp.o (ex build/tcpStack/libtcpStack.a)
   8873       8    3744   12625    3151 ProtocolTCP.cpp.o (ex build/tcpStack/libtcpStack.a)
    717       0       0     717     2cd ProtocolUDP.cpp.o (ex build/tcpStack/libtcpStack.a)
   2731       0      84    2815     aff Utility.cpp.o (ex build/tcpStack/libtcpStack.a)