Currently, device driver xdp attachments, tcx, netkit and old-style tc classifier/action attachments, flow_dissector as well as netfilter attachments are implemented, i.e., for program types BPF_PROG_TYPE_XDP, BPF_PROG_TYPE_SCHED_CLS, BPF_PROG_TYPE_SCHED_ACT, BPF_PROG_TYPE_FLOW_DISSECTOR, BPF_PROG_TYPE_NETFILTER.

For programs attached to a particular cgroup, e.g., BPF_PROG_TYPE_CGROUP_SKB, BPF_PROG_TYPE_CGROUP_SOCK, BPF_PROG_TYPE_SOCK_OPS and BPF_PROG_TYPE_CGROUP_SOCK_ADDR, users can use bpftool cgroup to dump cgroup attachments. For sk_{filter, skb, msg, reuseport} and lwt/seg6 bpf programs, users should consult other tools, e.g., iproute2.

The current output will start with all xdp program attachments, followed by all tcx, netkit, then tc class/qdisc bpf program attachments, then flow_dissector and finally netfilter programs. Both xdp programs and tcx/netkit/tc programs are ordered based on ifindex number. If multiple bpf programs attached to the same networking device through tc, the order will be first all bpf programs attached to tcx, netkit, then tc classes, then all bpf programs attached to non clsact qdiscs, and finally all bpf programs attached to root and clsact qdisc.

ATTACH_TYPE can be of: xdp - try native XDP and fallback to generic XDP if NIC driver does not support it; xdpgeneric - Generic XDP. runs at generic XDP hook when packet already enters receive path as skb; xdpdrv - Native XDP. runs earliest point in driver's receive path; xdpoffload - Offload XDP. runs directly on NIC on each packet reception; tcx_ingress - Ingress TCX. runs on ingress net traffic; tcx_egress - Egress TCX. runs on egress net traffic;