bpftool-cgroup - tool for inspection and simple manipulation of eBPF progs
bpftool [OPTIONS] cgroup COMMAND
OPTIONS := { { -j | --json } [{ -p | --pretty }] | { -d | --debug } | { -f | --bpffs } }
COMMANDS := { show | list | tree | attach | detach | help }
bpftool cgroup { show | list } CGROUP [effective]
bpftool cgroup tree [CGROUP_ROOT] [effective]
bpftool cgroup attach CGROUP ATTACH_TYPE PROG [ATTACH_FLAGS]
bpftool cgroup detach CGROUP ATTACH_TYPE PROG
bpftool cgroup help
PROG := { id PROG_ID | pinned FILE | tag PROG_TAG }
ATTACH_TYPE := { ingress | egress | sock_create | sock_ops | device |
bind4 | bind6 | post_bind4 | post_bind6 | connect4 | connect6 |
getpeername4 | getpeername6 | getsockname4 | getsockname6 | sendmsg4 |
sendmsg6 | recvmsg4 | recvmsg6 | sysctl | getsockopt | setsockopt |
sock_release }
ATTACH_FLAGS := { multi | override }
- bpftool cgroup { show | list } CGROUP [effective]
List all programs attached to the cgroup CGROUP.
Output will start with program ID followed by attach type, attach flags and program name.
If effective is specified retrieve effective programs that will execute for events within a cgroup. This includes inherited along with attached ones.
- bpftool cgroup tree [CGROUP_ROOT] [effective]
Iterate over all cgroups in CGROUP_ROOT and list all attached programs. If CGROUP_ROOT is not specified, bpftool uses cgroup v2 mountpoint.
The output is similar to the output of cgroup show/list commands: it starts with absolute cgroup path, followed by program ID, attach type, attach flags and program name.
If effective is specified retrieve effective programs that will execute for events within a cgroup. This includes inherited along with attached ones.
- bpftool cgroup attach CGROUP ATTACH_TYPE PROG [ATTACH_FLAGS]
Attach program PROG to the cgroup CGROUP with attach type ATTACH_TYPE and optional ATTACH_FLAGS.
ATTACH_FLAGS can be one of: override if a sub-cgroup installs some bpf program, the program in this cgroup yields to sub-cgroup program; multi if a sub-cgroup installs some bpf program, that cgroup program gets run in addition to the program in this cgroup.
Only one program is allowed to be attached to a cgroup with no attach flags or the override flag. Attaching another program will release old program and attach the new one.
Multiple programs are allowed to be attached to a cgroup with multi. They are executed in FIFO order (those that were attached first, run first).
Non-default ATTACH_FLAGS are supported by kernel version 4.14 and later.
ATTACH_TYPE can be on of: ingress ingress path of the inet socket (since 4.10); egress egress path of the inet socket (since 4.10); sock_create opening of an inet socket (since 4.10); sock_ops various socket operations (since 4.12); device device access (since 4.15); bind4 call to bind(2) for an inet4 socket (since 4.17); bind6 call to bind(2) for an inet6 socket (since 4.17); post_bind4 return from bind(2) for an inet4 socket (since 4.17); post_bind6 return from bind(2) for an inet6 socket (since 4.17); connect4 call to connect(2) for an inet4 socket (since 4.17); connect6 call to connect(2) for an inet6 socket (since 4.17); sendmsg4 call to sendto(2), sendmsg(2), sendmmsg(2) for an unconnected udp4 socket (since 4.18); sendmsg6 call to sendto(2), sendmsg(2), sendmmsg(2) for an unconnected udp6 socket (since 4.18); recvmsg4 call to recvfrom(2), recvmsg(2), recvmmsg(2) for an unconnected udp4 socket (since 5.2); recvmsg6 call to recvfrom(2), recvmsg(2), recvmmsg(2) for an unconnected udp6 socket (since 5.2); sysctl sysctl access (since 5.2); getsockopt call to getsockopt (since 5.3); setsockopt call to setsockopt (since 5.3); getpeername4 call to getpeername(2) for an inet4 socket (since 5.8); getpeername6 call to getpeername(2) for an inet6 socket (since 5.8); getsockname4 call to getsockname(2) for an inet4 socket (since 5.8); getsockname6 call to getsockname(2) for an inet6 socket (since 5.8). sock_release closing an userspace inet socket (since 5.9).
- bpftool cgroup detach CGROUP ATTACH_TYPE PROG
Detach PROG from the cgroup CGROUP and attach type ATTACH_TYPE.
- bpftool prog help
Print short help message.
- -h, --help
Print short help message (similar to bpftool help).
- -V, --version
Print version number (similar to bpftool version), and optional features that were included when bpftool was compiled. Optional features include linking against libbfd to provide the disassembler for JIT-ted programs (bpftool prog dump jited) and usage of BPF skeletons (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.
- -f, --bpffs
Show file names of pinned programs.
# mount -t bpf none /sys/fs/bpf/
# mkdir /sys/fs/cgroup/test.slice
# bpftool prog load ./device_cgroup.o /sys/fs/bpf/prog
# bpftool cgroup attach /sys/fs/cgroup/test.slice/ device id 1 allow_multi# bpftool cgroup list /sys/fs/cgroup/test.slice/
ID AttachType AttachFlags Name 1 device allow_multi bpf_prog1
# bpftool cgroup detach /sys/fs/cgroup/test.slice/ device id 1
# bpftool cgroup list /sys/fs/cgroup/test.slice/ID AttachType AttachFlags Name
bpf(2), bpf-helpers(7), bpftool(8), bpftool-btf(8), bpftool-feature(8), bpftool-gen(8), bpftool-iter(8), bpftool-link(8), bpftool-map(8), bpftool-net(8), bpftool-perf(8), bpftool-prog(8), bpftool-struct_ops(8)