bpf-program block

The bpf-program block declares a named eBPF object that fastSwan can attach to one or several interfaces. Programs are stored as struct fswan_bpf_prog in daemon_data->bpf_progs and carry the filesystem path, an optional section name, and a lifecycle flag.

A program declaration is independent of any interface; bringing the program up (no shutdown) only loads the object into the kernel. The actual XDP attach happens when an interface block referencing this program is itself brought up.

bpf-program xdp-xfrm
 description Main XDP/XFRM offload program
 path /etc/fastswan/xfrm_offload.bpf
 no shutdown

bpf-program STRING

Declare or enter the configuration block of a named BPF program. STRING is the symbolic name referenced later from interface blocks.

fastSwan(config)# bpf-program xdp-xfrm
fastSwan(config-bpf)#

no bpf-program STRING

Detach every interface using this program, unload the BPF object, then drop the declaration.

Inside the bpf-program block

description LINE

Free-form label stored alongside the BPF program. Purely informational, surfaced by config write and the show commands.

path STRING

Absolute filesystem path of the compiled .bpf object that libbpf will open when this program is brought up (no shutdown).

bpf-program xdp-xfrm
 path /etc/fastswan/xfrm_offload.bpf

prog-name STRING

Override the BPF section/function name to attach when the object contains several programs. Defaults to the first XDP program found.

bpf-program xdp-xfrm
 path /etc/fastswan/xfrm_offload.bpf
 prog-name xfrm_offload

shutdown

Detach every interface bound to this program and unload the BPF object from the kernel. The declaration itself is preserved, so a later no shutdown re-loads the same object.

no shutdown

Open the .bpf object set by path, run the kernel verifier and wire the XFRM offload maps. Required before any interface can attach to this program.