mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
109 lines
2.8 KiB
109 lines
2.8 KiB
================ |
|
bpftool-link |
|
================ |
|
------------------------------------------------------------------------------- |
|
tool for inspection and simple manipulation of eBPF links |
|
------------------------------------------------------------------------------- |
|
|
|
:Manual section: 8 |
|
|
|
SYNOPSIS |
|
======== |
|
|
|
**bpftool** [*OPTIONS*] **link** *COMMAND* |
|
|
|
*OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-d** | **--debug** } | |
|
{ **-f** | **--bpffs** } | { **-n** | **--nomount** } } |
|
|
|
*COMMANDS* := { **show** | **list** | **pin** | **help** } |
|
|
|
LINK COMMANDS |
|
============= |
|
|
|
| **bpftool** **link { show | list }** [*LINK*] |
|
| **bpftool** **link pin** *LINK* *FILE* |
|
| **bpftool** **link detach** *LINK* |
|
| **bpftool** **link help** |
|
| |
|
| *LINK* := { **id** *LINK_ID* | **pinned** *FILE* } |
|
|
|
|
|
DESCRIPTION |
|
=========== |
|
**bpftool link { show | list }** [*LINK*] |
|
Show information about active links. If *LINK* is |
|
specified show information only about given link, |
|
otherwise list all links currently active on the system. |
|
|
|
Output will start with link ID followed by link type and |
|
zero or more named attributes, some of which depend on type |
|
of link. |
|
|
|
Since Linux 5.8 bpftool is able to discover information about |
|
processes that hold open file descriptors (FDs) against BPF |
|
links. On such kernels bpftool will automatically emit this |
|
information as well. |
|
|
|
**bpftool link pin** *LINK* *FILE* |
|
Pin link *LINK* as *FILE*. |
|
|
|
Note: *FILE* must be located in *bpffs* mount. It must not |
|
contain a dot character ('.'), which is reserved for future |
|
extensions of *bpffs*. |
|
|
|
**bpftool link detach** *LINK* |
|
Force-detach link *LINK*. BPF link and its underlying BPF |
|
program will stay valid, but they will be detached from the |
|
respective BPF hook and BPF link will transition into |
|
a defunct state until last open file descriptor for that |
|
link is closed. |
|
|
|
**bpftool link help** |
|
Print short help message. |
|
|
|
OPTIONS |
|
======= |
|
.. include:: common_options.rst |
|
|
|
-f, --bpffs |
|
When showing BPF links, show file names of pinned |
|
links. |
|
|
|
-n, --nomount |
|
Do not automatically attempt to mount any virtual file system |
|
(such as tracefs or BPF virtual file system) when necessary. |
|
|
|
EXAMPLES |
|
======== |
|
**# bpftool link show** |
|
|
|
:: |
|
|
|
10: cgroup prog 25 |
|
cgroup_id 614 attach_type egress |
|
pids test_progs(223) |
|
|
|
**# bpftool --json --pretty link show** |
|
|
|
:: |
|
|
|
[{ |
|
"type": "cgroup", |
|
"prog_id": 25, |
|
"cgroup_id": 614, |
|
"attach_type": "egress", |
|
"pids": [{ |
|
"pid": 223, |
|
"comm": "test_progs" |
|
} |
|
] |
|
} |
|
] |
|
|
|
| |
|
| **# bpftool link pin id 10 /sys/fs/bpf/link** |
|
| **# ls -l /sys/fs/bpf/** |
|
|
|
:: |
|
|
|
-rw------- 1 root root 0 Apr 23 21:39 link
|
|
|