mirror of
https://gitee.com/bianbu-linux/linux-6.6
synced 2025-04-24 14:07:52 -04:00
9406b485de
Currently, only one command is supported
bpftool iter pin <bpf_prog.o> <path>
It will pin the trace/iter bpf program in
the object file <bpf_prog.o> to the <path>
where <path> should be on a bpffs mount.
For example,
$ bpftool iter pin ./bpf_iter_ipv6_route.o \
/sys/fs/bpf/my_route
User can then do a `cat` to print out the results:
$ cat /sys/fs/bpf/my_route
fe800000000000000000000000000000 40 00000000000000000000000000000000 ...
00000000000000000000000000000000 00 00000000000000000000000000000000 ...
00000000000000000000000000000001 80 00000000000000000000000000000000 ...
fe800000000000008c0162fffebdfd57 80 00000000000000000000000000000000 ...
ff000000000000000000000000000000 08 00000000000000000000000000000000 ...
00000000000000000000000000000000 00 00000000000000000000000000000000 ...
The implementation for ipv6_route iterator is in one of subsequent
patches.
This patch also added BPF_LINK_TYPE_ITER to link query.
In the future, we may add additional parameters to pin command
by parameterizing the bpf iterator. For example, a map_id or pid
may be added to let bpf program only traverses a single map or task,
similar to kernel seq_file single_open().
We may also add introspection command for targets/iterators by
leveraging the bpf_iter itself.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200509175920.2477247-1-yhs@fb.com
88 lines
1.6 KiB
C
88 lines
1.6 KiB
C
// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
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// Copyright (C) 2020 Facebook
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#define _GNU_SOURCE
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#include <linux/err.h>
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#include <bpf/libbpf.h>
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#include "main.h"
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static int do_pin(int argc, char **argv)
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{
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const char *objfile, *path;
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struct bpf_program *prog;
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struct bpf_object *obj;
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struct bpf_link *link;
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int err;
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if (!REQ_ARGS(2))
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usage();
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objfile = GET_ARG();
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path = GET_ARG();
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obj = bpf_object__open(objfile);
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if (IS_ERR(obj)) {
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p_err("can't open objfile %s", objfile);
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return -1;
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}
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err = bpf_object__load(obj);
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if (err) {
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p_err("can't load objfile %s", objfile);
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goto close_obj;
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}
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prog = bpf_program__next(NULL, obj);
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if (!prog) {
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p_err("can't find bpf program in objfile %s", objfile);
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goto close_obj;
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}
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link = bpf_program__attach_iter(prog, NULL);
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if (IS_ERR(link)) {
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err = PTR_ERR(link);
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p_err("attach_iter failed for program %s",
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bpf_program__name(prog));
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goto close_obj;
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}
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err = mount_bpffs_for_pin(path);
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if (err)
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goto close_link;
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err = bpf_link__pin(link, path);
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if (err) {
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p_err("pin_iter failed for program %s to path %s",
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bpf_program__name(prog), path);
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goto close_link;
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}
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close_link:
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bpf_link__destroy(link);
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close_obj:
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bpf_object__close(obj);
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return err;
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}
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static int do_help(int argc, char **argv)
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{
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fprintf(stderr,
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"Usage: %s %s pin OBJ PATH\n"
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" %s %s help\n"
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"\n",
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bin_name, argv[-2], bin_name, argv[-2]);
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return 0;
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}
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static const struct cmd cmds[] = {
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{ "help", do_help },
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{ "pin", do_pin },
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{ 0 }
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};
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int do_iter(int argc, char **argv)
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{
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return cmd_select(cmds, argc, argv, do_help);
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}
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