gSwitch

This is a user space switch (network pipeline processing) written in go for learning purposes (still work in progress).

Configuration:

[Redis]
Address = "127.0.0.1"
Port = 6379
Password = ""
DB = 0
Prefix = ""

[SwitchPorts]
    [SwitchPorts.sw1]
    Trunk = false
    AllowedVLANs = [1]
    Up = true

    [SwitchPorts.sw2]
    Trunk = true
    AllowedVLANs = [1, 10]
    Up = true


[[ControlProcess]]
Layer = 2
Name = "Hub"

1- Redis (not used yet):

Redis is the backend datastore for this switch during runtime.

2- SwitchPorts:

This represents the ports that will be added to the switch.

Trunk: whether the port is trunk or access port (not implemented yet)
AllowedVLANs: in case Trunk is false, specify only one vlan number, otherwise it includes the allowed vlans on the trunk (eg. [10, 11, 12])
Up: represents the initial status of the port whether it should be brought up on startup or not

3- ControlProcess:

Control processes are what defines how the traffic is handled by the switch. currently only a L2Hub and L2Switch are implemented.

Layer: represents the layer this process handles
Name: name of the process
ConfigFile: path to process configuration file (if needed)

Try It:

1- Get the Package

go get github.com/m-motawea/gSwitch

2- Go the package dir and build it

cd ~/go/src/github.com/m-motawea/gSwitch # change the location if you installed go in a custom location
go build

3- Initialize a test environment by network namespaces:

sudo ./scripts/env_setup.sh

this will create 5 namespaces as hosts (h1,..h4) and a one as switch sw
h1 & h2 IP address are 10.1.1.10 and 10.1.1.20
h2 & h3 IP address are 10.10.1.30 and 10.10.1.40

4- Start the switch in the sw namepace with the default config in the package:

sudo ip netns exec sw ./gSwitch

h1 and h2 are connected to sw as access ports on vlan 1
h3and h4are connected to sw as access ports on vlan 10
Control processes include the L2Switch, ARP, IPv4, ICMP and Routing as well as each layer adapter process.

5- Test connectivity example:

sudo ip netns exec h1 ping 10.1.1.20 # connection to h2
sudo ip netns exec h1 ping 10.10.1.40 # connection to h4 (routed)

6- Clean the test environment:

sudo ./scripts/env_destroy.sh

TODO:

1- Try to Fix Trunk Ports (due to stripped vlan tags)

currently trunk link is not working but to get around this you can use subinterfaces.
create a sub interface for each vlan and use the sub interface in configuration instaed of the Master.

ip link add link <master> name <sub name> type vlan id <id>

make sure to set the trunk option for the subinterface as false other wise there will be two layers of 802.1Q.

[SwitchPorts."sw5.10"]
Trunk = false
AllowedVLANs = [10]
Up = true

[SwitchPorts."sw5.1"]
Trunk = false
AllowedVLANs = [1]
Up = true

2- Handle L2 Loops Using STP (needs support for 802.3)

3- Document Current Processes