linux/tools/bpf/bpftool/iter.c
Pengcheng Yang 2a36c26fe3 bpftool: Support bpffs mountpoint as pin path for prog loadall
Currently, when using prog loadall and the pin path is a bpffs mountpoint,
bpffs will be repeatedly mounted to the parent directory of the bpffs
mountpoint path. For example, a `bpftool prog loadall test.o /sys/fs/bpf`
will trigger this.

Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/1683342439-3677-1-git-send-email-yangpc@wangsu.com
2023-05-17 15:58:18 +02:00

124 lines
2.3 KiB
C

// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
// Copyright (C) 2020 Facebook
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <errno.h>
#include <unistd.h>
#include <linux/err.h>
#include <bpf/libbpf.h>
#include "main.h"
static int do_pin(int argc, char **argv)
{
DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, iter_opts);
union bpf_iter_link_info linfo;
const char *objfile, *path;
struct bpf_program *prog;
struct bpf_object *obj;
struct bpf_link *link;
int err = -1, map_fd = -1;
if (!REQ_ARGS(2))
usage();
objfile = GET_ARG();
path = GET_ARG();
/* optional arguments */
if (argc) {
if (is_prefix(*argv, "map")) {
NEXT_ARG();
if (!REQ_ARGS(2)) {
p_err("incorrect map spec");
return -1;
}
map_fd = map_parse_fd(&argc, &argv);
if (map_fd < 0)
return -1;
memset(&linfo, 0, sizeof(linfo));
linfo.map.map_fd = map_fd;
iter_opts.link_info = &linfo;
iter_opts.link_info_len = sizeof(linfo);
}
}
obj = bpf_object__open(objfile);
if (!obj) {
err = -errno;
p_err("can't open objfile %s", objfile);
goto close_map_fd;
}
err = bpf_object__load(obj);
if (err) {
p_err("can't load objfile %s", objfile);
goto close_obj;
}
prog = bpf_object__next_program(obj, NULL);
if (!prog) {
err = -errno;
p_err("can't find bpf program in objfile %s", objfile);
goto close_obj;
}
link = bpf_program__attach_iter(prog, &iter_opts);
if (!link) {
err = -errno;
p_err("attach_iter failed for program %s",
bpf_program__name(prog));
goto close_obj;
}
err = mount_bpffs_for_pin(path, false);
if (err)
goto close_link;
err = bpf_link__pin(link, path);
if (err) {
p_err("pin_iter failed for program %s to path %s",
bpf_program__name(prog), path);
goto close_link;
}
close_link:
bpf_link__destroy(link);
close_obj:
bpf_object__close(obj);
close_map_fd:
if (map_fd >= 0)
close(map_fd);
return err;
}
static int do_help(int argc, char **argv)
{
fprintf(stderr,
"Usage: %1$s %2$s pin OBJ PATH [map MAP]\n"
" %1$s %2$s help\n"
"\n"
" " HELP_SPEC_MAP "\n"
" " HELP_SPEC_OPTIONS " }\n"
"",
bin_name, "iter");
return 0;
}
static const struct cmd cmds[] = {
{ "help", do_help },
{ "pin", do_pin },
{ 0 }
};
int do_iter(int argc, char **argv)
{
return cmd_select(cmds, argc, argv, do_help);
}