xv6-riscv-net

This project integrates a TCP/IP protocol stack into the xv6-riscv operating system, enabling network capabilities.

Key Components:

• TCP/IP Stack: A kernel-space port of microps, a user-mode TCP/IP stack that I am also developing.

• Network Driver: A virtio-net driver for network device emulation in QEMU.

• Socket API: A standard socket interface for network applications.

• Network Configuration: A simple ifconfig command for basic network settings.

Quick Start

1. Build and Run

Clone the repository and use the make qemu command.

$ git clone https://github.com/pandax381/xv6-riscv-net
$ cd xv6-riscv-net
$ make qemu

Note

This command will build the project and launch QEMU. On the first run, it will also create a TAP network device named tap0 on your host machine and assign it the IP address 192.0.2.1/24. This enables network communication between the xv6 guest and the host.

2. Network Configuration in xv6

Once xv6 has booted, use the ifconfig command to configure the net0 network interface. We'll assign it the IP address 192.0.2.2, as the host is using 192.0.2.1.

$ ifconfig net0 192.0.2.2 netmask 255.255.255.0

After setting the IP address, run the ifconfig command again to verify that the network settings have been applied.

$ ifconfig
net0: flags=93<UP|BROADCAST|RUNNING|NEEDARP> mtu 1500
        ether 52:54:00:12:34:56
        inet 192.0.2.2 netmask 255.255.255.0 broadcast 192.0.2.255

The setup is now complete. You can verify the communication by pinging the xv6 guest from a terminal on your host machine.

$ ping 192.0.2.2
PING 192.0.2.2 (192.0.2.2) 56(84) bytes of data.
64 bytes from 192.0.2.2: icmp_seq=1 ttl=255 time=0.444 ms
...

3. Running the Sample Programs

This project includes tcpecho and udpecho as sample user-level applications to demonstrate the network stack. Here is how to test the TCP echo server.

In the xv6 shell, run the tcpecho command. It will start a server listening on port 7.

$ tcpecho
Starting TCP Echo Server
socket: success, soc=3
bind: success, self=0.0.0.0:7
waiting for connection...

Open a new terminal on your host machine and use nc (netcat) to connect to the tcpecho server running inside QEMU.

$ nc -v 192.0.2.2 7

Once the connection succeeds, type any message into the nc terminal and press Enter. The message will be sent to the xv6 tcpecho server, which will then echo it back to your terminal.

Connection to 192.0.2.2 7 port [tcp/echo] succeeded!
hoge
hoge
fuga
fuga

On the xv6 guest, tcpecho will output messages like the following after a connection is established and data is received:

accept: success, peer=192.0.2.1:33680
recv: 5 bytes data received
> hoge
recv: 5 bytes data received
> fuga

License

xv6-riscv: Under the MIT License. See LICENSE file.

Additional code: Under the MIT License.