Build the Podman Container for developing

In the podman folder, there is a README that details how to build the container for development purposes and for testing the eBPF/XDP programs.

XDP/eBPF Programs

The src/c folder contains the xdp.bpf.c file, which includes three different XDP programs:

1. sr6_encap:
   This program implements the SRv6 H.Encaps.Red. Currently, only encapsulation with one SID is supported, and the SRH is not used in any case. This program is intended to be attached to a network device receiving IPv4 traffic. Upon receiving IPv4 traffic, the program checks for the IPv4 Destination Address (DA) in the eBPF map called sr6encap_ip4_table. This map uses the IPv4 DA as the key, with the value consisting of the IPv6 Source Address for the tunnel and the SID (composed of several micro SIDs) to be included in the outer IPv6 Destination Address (DA).
   For information on how this program is used, please refer to tests/encap_decap_vrf_test.sh.

2. sr6_decap:
   This program implements the SRv6 End.DT4 behavior. It decapsulates inner IPv4 traffic by matching the outer IPv6 DA with the decap SID in the eBPF sr6decap_table map. If the IPv6 DA matches an entry in that map, the program retrieves the table used for performing the routing lookup of the decapsulated IPv4 packet. For information on how this program is used, please refer to tests/encap_decap_vrf_test.sh.

3. xdp_pass:
   A dummy program that can be attached to veth pairs, enabling the redirect XDP helper functions to work.

Tests

A testbed simulating a (small) virtual data center network is available in the tests folder. Specifically, the encap_decap_vrf_tests.sh script creates a virtual network composed of several network namespaces connected with veth pairs. To run the test, execute the script and ping from h0 to h1 using the following command:

# ping 10.0.2.1

The command should succeed, with packets encapsulated on gw1, routed on rt0, and decapsulated on gw2, which then sends plain IPv4 traffic to the h1 destination.