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author | Yonghong Song <yhs@fb.com> | 2020-05-09 20:59:20 +0300 |
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committer | Alexei Starovoitov <ast@kernel.org> | 2020-05-10 03:05:27 +0300 |
commit | 9406b485dea5e25bed7c81cd822747d494cc8bde (patch) | |
tree | cf9cc5392af40aefce4a272233d977da23bff7a1 /tools/bpf/bpftool/iter.c | |
parent | 5fbc220862fc7a53a0455ccd2d96c82141e222d4 (diff) | |
download | linux-9406b485dea5e25bed7c81cd822747d494cc8bde.tar.xz |
tools/bpftool: Add bpf_iter support for bptool
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
Diffstat (limited to 'tools/bpf/bpftool/iter.c')
-rw-r--r-- | tools/bpf/bpftool/iter.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/tools/bpf/bpftool/iter.c b/tools/bpf/bpftool/iter.c new file mode 100644 index 000000000000..eb5987a0c3b6 --- /dev/null +++ b/tools/bpf/bpftool/iter.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +// Copyright (C) 2020 Facebook + +#define _GNU_SOURCE +#include <linux/err.h> +#include <bpf/libbpf.h> + +#include "main.h" + +static int do_pin(int argc, char **argv) +{ + const char *objfile, *path; + struct bpf_program *prog; + struct bpf_object *obj; + struct bpf_link *link; + int err; + + if (!REQ_ARGS(2)) + usage(); + + objfile = GET_ARG(); + path = GET_ARG(); + + obj = bpf_object__open(objfile); + if (IS_ERR(obj)) { + p_err("can't open objfile %s", objfile); + return -1; + } + + err = bpf_object__load(obj); + if (err) { + p_err("can't load objfile %s", objfile); + goto close_obj; + } + + prog = bpf_program__next(NULL, obj); + if (!prog) { + p_err("can't find bpf program in objfile %s", objfile); + goto close_obj; + } + + link = bpf_program__attach_iter(prog, NULL); + if (IS_ERR(link)) { + err = PTR_ERR(link); + p_err("attach_iter failed for program %s", + bpf_program__name(prog)); + goto close_obj; + } + + err = mount_bpffs_for_pin(path); + 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); + return err; +} + +static int do_help(int argc, char **argv) +{ + fprintf(stderr, + "Usage: %s %s pin OBJ PATH\n" + " %s %s help\n" + "\n", + bin_name, argv[-2], bin_name, argv[-2]); + + 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); +} |