This is a user-space port of the FreeBSD TCP/IP stack, begun with the FreeBSD 9.1-RELEASE sources and many pieces of Kip Macy's user-space port of an earlier version of the FreeBSD stack, libplebnet.
Unlike the stock FreeBSD TCP/IP stack, this stack can initiate and terminate arbitrary TCP/IP connections, including those on arbitrarily-nested VLANs. Listen sockets can be bound to a wildcard IP address (across everything on the wire, not just local interfaces), wildcard port, and specific VLAN tag stacks. L2 information for accepted connections is available to the application. Outbound connections can be bound to any IP and port, as well as any MAC address and VLAN tag stack.
This stack can also passively reconstruct TCP streams using a copy of those streams' bidirectional packet flow. Reconstruction can continue even in the face of packet loss (in which case zero-filled holes in the affected streams are reported to the application).
Packet I/O is currently accomplished via netmap or libpcap (although the latter interface is relatively new and untested).
The most up-to-date sources are on master.
A large merge to master was performed on 24 March 2016, which includes API churn. The pre-merge point was tagged as master_20160324.
GNU make is used to build libuinet and its sample programs. Under Linux, this is simply 'make', while under FreeBSD, this is available as gmake. The instructions that follow refer to 'gmake'.
To build everything after a clean checkout:
gmake
To rebuild everything from scratch at any point:
gmake clean config all
If your netmap includes are not in the system include path,
gmake NETMAP_INCLUDES=
The make variable DEBUG_FLAGS provides a quick way to adjust the optimization level and debug symbol generation. For example:
gmake DEBUG_FLAGS="-O2 -ggdb" clean config all
The core of the demo programs are implemented in lib/libuinet_demo. They can be run via the single front-end bin/multitool.
The currently functioning demo programs are:
connscale A TCP connection generator/terminator echo A loopback server passive A passive reconstructor passive_extract A passive reconstructor that extracts file from HTTP streams
Still waiting to be updated is:
echo++ A C++ loopback server tproxy A transparent proxy
The sysctl code (and likely more over time) uses libnv from FreeBSD-HEAD to serialise data between processes.
Currently, the sysctl and vmstat tools that interact with a libuinet instance are only buildable on FreeBSD hosts.