=========== You should know that some source code in this project is = WARNING = not a best practice and immature. =========== -- 2015/10/28
A user-mode TCP/IP stack based on linux tap device
- linux tun/tap device (/dev/net/tun exists if supported)
$ make # ./tapip (run as root) [net shell]: ping 10.0.0.2 (ping linux kernel TCP/IP stack) (waiting icmp echo reply...) [net shell]: help (see all embedded commands) ...
The corresponding network topology is here.
_socket,_read,_write,_send,_recv,_connect,_bind,_close and _listen are provided now.
Three socket types(SOCK_STREAM, SOCK_DGRAM, SOCK_RAW) can be used.
You can use these apis to write applications working on tapip.
Good examples are app/ping.c and app/snc.c.
How to implement
I refer to xinu and Linux 2.6.11 TCP/IP stack and use linux tap device to simulate net device(for l2).
A small shell is embedded in tapip.
So this is just user-mode TCP/IP stack :)
Tapip makes it easy to hack TCP/IP stack, just compiling it to run.
It can also do some network test: arp snooping, proxy, and NAT!
I think the most important is that tapip helps me learn TCP/IP, and understand linux TCP/IP stack.
You can refer to saminiir/level-ip and its blog posts for more details.