xdp-project-bng-router

mirror of https://github.com/xdp-project/BNG-router.git synced 2024-05-06 15:54:53 +00:00

History

Yoel Caspersen 09bc68580f Moving Option 82 to end of options as per RFC3046 section 2.1.

Adjusting tail instead of headers because of complications with
variable length DHCP options - beware that this doesn't appear to work
with veth interfaces. Use a physical NIC for testing for now.

2021-10-13 20:11:06 +02:00

.gitignore

Import build config and DHCP relay code from bpf-examples

2021-08-18 14:40:32 +02:00

dhcp_kern_xdp.c

Moving Option 82 to end of options as per RFC3046 section 2.1.

2021-10-13 20:11:06 +02:00

dhcp_user_xdp.c

Moving Option 82 to end of options as per RFC3046 section 2.1.

2021-10-13 20:11:06 +02:00

dhcp-relay.h

Moving Option 82 to end of options as per RFC3046 section 2.1.

2021-10-13 20:11:06 +02:00

Makefile

Import build config and DHCP relay code from bpf-examples

2021-08-18 14:40:32 +02:00

README

Moving Option 82 to end of options as per RFC3046 section 2.1.

2021-10-13 20:11:06 +02:00

README

Usage
-----
dhcp_user_xdp takes network interface, DHCP server IP and DHCP relay agent IP
as inputs and stores them in a map. Filters the incoming DHCP requests and inserts
option 82 in the DHCP request packets and overwrites the destination IP to that
of DHCP relay server IP.

Build instructions:
cd bpf-examples/dhcp-relay
make

Loading bpf program:
sudo ./dhcp_user_xdp -i <netif> -d <dhcp server IP> -s <dhcp relay agent IP>
where,
netif: Ingress network interface name

unloading program:
sudo ./dhcp_user_xdp -i <netif> -u 

To run in SKB mode:
add option "-m skb" for both load and uload commands

Please beware that testing requires a physical NIC because we tail extend
packets due to complications with variable length DHCP options.

Enable forwarding and allow local address spoofing:
sudo echo 1 > /proc/sys/net/ipv4/ip_forward
sudo echo 1 > /proc/sys/net/ipv4/conf/all/accept_local

Verify using tcpdump:
sudo tcpdump -s 0 -i <netif> port 67 and port 68 -vvv