Manual: bpftool-net
bpftool-net(8) System Manager's Manual bpftool-net(8)
Name
bpftool-net - tool for inspection of networking related bpf prog attachments
SYNOPSIS
bpftool [OPTIONS] net COMMAND
OPTIONS := { { -j | --json } [{ -p | --pretty }] | { -d | --debug } }
COMMANDS := { show | list | attach | detach | help }
NET COMMANDS
bpftool net { show | list } [ dev NAME ]
bpftool net attach ATTACH_TYPE PROG dev NAME [ overwrite | prepend ]
bpftool net detach ATTACH_TYPE dev NAME
bpftool net help
PROG := { id PROG_ID | pinned FILE | tag PROG_TAG | name PROG_NAME }
ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload | tcx_ingress | tcx_egress }
DESCRIPTION
bpftool net { show | list } [ dev NAME ]
List bpf program attachments in the kernel networking subsystem.
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 attach‐
ments. 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 net‐
working 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.
bpftool net attach ATTACH_TYPE PROG dev NAME [ overwrite | prepend ]
Attach bpf program PROG to network interface NAME with type specified by ATTACH_TYPE.
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;
For XDP-related attach types (xdp, xdpgeneric, xdpdrv, xdpoffload), the overwrite option can be used to re‐
place a previously attached bpf program.
For tcx_ingress and tcx_egress attach types, the prepend option can be used to attach the program at the be‐
ginning of the chain instead of at the end.
bpftool net detach ATTACH_TYPE dev NAME
Detach bpf program attached to network interface NAME with type specified by ATTACH_TYPE. To detach bpf pro‐
gram, same ATTACH_TYPE previously used for attach must be specified.
bpftool net help
Print short help message.
OPTIONS
-h, --help
Print short help message (similar to bpftool help).
-V, --version
Print bpftool's version number (similar to bpftool version), the number of the libbpf version in use, and op‐
tional features that were included when bpftool was compiled. Optional features include linking against LLVM
or libbfd to provide the disassembler for JIT-ted programs (bpftool prog dump jited) and usage of BPF skele‐
tons (some features like bpftool prog profile or showing pids associated to BPF objects may rely on it).
-j, --json
Generate JSON output. For commands that cannot produce JSON, this option has no effect.
-p, --pretty
Generate human-readable JSON output. Implies -j.
-d, --debug
Print all logs available, even debug-level information. This includes logs from libbpf as well as from the
verifier, when attempting to load programs.
EXAMPLES
# bpftool net
xdp:
eth0(2) driver id 198
tc:
eth0(2) htb name prefix_matcher.o:[cls_prefix_matcher_htb] id 111727 act []
eth0(2) clsact/ingress fbflow_icmp id 130246 act []
eth0(2) clsact/egress prefix_matcher.o:[cls_prefix_matcher_clsact] id 111726
eth0(2) clsact/egress cls_fg_dscp id 108619 act []
eth0(2) clsact/egress fbflow_egress id 130245
# bpftool -jp net
[{
"xdp": [{
"devname": "eth0",
"ifindex": 2,
"mode": "driver",
"id": 198
}
],
"tc": [{
"devname": "eth0",
"ifindex": 2,
"kind": "htb",
"name": "prefix_matcher.o:[cls_prefix_matcher_htb]",
"id": 111727,
"act": []
},{
"devname": "eth0",
"ifindex": 2,
"kind": "clsact/ingress",
"name": "fbflow_icmp",
"id": 130246,
"act": []
},{
"devname": "eth0",
"ifindex": 2,
"kind": "clsact/egress",
"name": "prefix_matcher.o:[cls_prefix_matcher_clsact]",
"id": 111726,
},{
"devname": "eth0",
"ifindex": 2,
"kind": "clsact/egress",
"name": "cls_fg_dscp",
"id": 108619,
"act": []
},{
"devname": "eth0",
"ifindex": 2,
"kind": "clsact/egress",
"name": "fbflow_egress",
"id": 130245,
}
]
}
]
# bpftool net attach xdpdrv id 16 dev enp6s0np0
# bpftool net
xdp:
enp6s0np0(4) driver id 16
# bpftool net attach xdpdrv id 16 dev enp6s0np0
# bpftool net attach xdpdrv id 20 dev enp6s0np0 overwrite
# bpftool net
xdp:
enp6s0np0(4) driver id 20
# bpftool net attach xdpdrv id 16 dev enp6s0np0
# bpftool net detach xdpdrv dev enp6s0np0
# bpftool net
xdp:
# bpftool net attach tcx_ingress name tc_prog dev lo
# bpftool net
tc:
lo(1) tcx/ingress tc_prog prog_id 29
# bpftool net attach tcx_ingress name tc_prog2 dev lo prepend
# bpftool net
tc:
lo(1) tcx/ingress tc_prog2 prog_id 30
lo(1) tcx/ingress tc_prog prog_id 29
# bpftool net attach tcx_ingress name tc_prog dev lo
# bpftool net detach tcx_ingress dev lo
# bpftool net
tc:
SEE ALSO
bpf(2), bpf-helpers(7), bpftool(8), bpftool-btf(8), bpftool-cgroup(8), bpftool-feature(8), bpftool-gen(8),
bpftool-iter(8), bpftool-link(8), bpftool-map(8), bpftool-perf(8), bpftool-prog(8), bpftool-struct_ops(8),
bpftool-token(8)
bpftool-net(8)