From d8793aca708602c676372b03d6493972457524af Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Thu, 23 Jul 2020 11:41:19 -0700 Subject: tools/bpftool: Add bpftool support for bpf map element iterator The optional parameter "map MAP" can be added to "bpftool iter" command to create a bpf iterator for map elements. For example, bpftool iter pin ./prog.o /sys/fs/bpf/p1 map id 333 For map element bpf iterator "map MAP" parameter is required. Otherwise, bpf link creation will return an error. Quentin Monnet kindly provided bash-completion implementation for new "map MAP" option. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200723184119.590799-1-yhs@fb.com --- tools/bpf/bpftool/Documentation/bpftool-iter.rst | 18 +++++++++++-- tools/bpf/bpftool/bash-completion/bpftool | 18 ++++++++++++- tools/bpf/bpftool/iter.c | 33 +++++++++++++++++++++--- 3 files changed, 62 insertions(+), 7 deletions(-) (limited to 'tools/bpf') diff --git a/tools/bpf/bpftool/Documentation/bpftool-iter.rst b/tools/bpf/bpftool/Documentation/bpftool-iter.rst index 8dce698eab79..070ffacb42b5 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-iter.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-iter.rst @@ -17,14 +17,15 @@ SYNOPSIS ITER COMMANDS =================== -| **bpftool** **iter pin** *OBJ* *PATH* +| **bpftool** **iter pin** *OBJ* *PATH* [**map** *MAP*] | **bpftool** **iter help** | | *OBJ* := /a/file/of/bpf_iter_target.o +| *MAP* := { **id** *MAP_ID* | **pinned** *FILE* } DESCRIPTION =========== - **bpftool iter pin** *OBJ* *PATH* + **bpftool iter pin** *OBJ* *PATH* [**map** *MAP*] A bpf iterator combines a kernel iterating of particular kernel data (e.g., tasks, bpf_maps, etc.) and a bpf program called for each kernel data object @@ -37,6 +38,12 @@ DESCRIPTION character ('.'), which is reserved for future extensions of *bpffs*. + Map element bpf iterator requires an additional parameter + *MAP* so bpf program can iterate over map elements for + that map. User can have a bpf program in kernel to run + with each map element, do checking, filtering, aggregation, + etc. without copying data to user space. + User can then *cat PATH* to see the bpf iterator output. **bpftool iter help** @@ -64,6 +71,13 @@ EXAMPLES Create a file-based bpf iterator from bpf_iter_netlink.o and pin it to /sys/fs/bpf/my_netlink +**# bpftool iter pin bpf_iter_hashmap.o /sys/fs/bpf/my_hashmap map id 20** + +:: + + Create a file-based bpf iterator from bpf_iter_hashmap.o and map with + id 20, and pin it to /sys/fs/bpf/my_hashmap + SEE ALSO ======== **bpf**\ (2), diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool index 7b137264ea3a..257fa310ea2b 100644 --- a/tools/bpf/bpftool/bash-completion/bpftool +++ b/tools/bpf/bpftool/bash-completion/bpftool @@ -615,7 +615,23 @@ _bpftool() iter) case $command in pin) - _filedir + case $prev in + $command) + _filedir + ;; + id) + _bpftool_get_map_ids + ;; + name) + _bpftool_get_map_names + ;; + pinned) + _filedir + ;; + *) + _bpftool_one_of_list $MAP_TYPE + ;; + esac return 0 ;; *) diff --git a/tools/bpf/bpftool/iter.c b/tools/bpf/bpftool/iter.c index 33240fcc6319..c9dba7543dba 100644 --- a/tools/bpf/bpftool/iter.c +++ b/tools/bpf/bpftool/iter.c @@ -2,6 +2,7 @@ // Copyright (C) 2020 Facebook #define _GNU_SOURCE +#include #include #include @@ -9,11 +10,12 @@ static int do_pin(int argc, char **argv) { + DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, iter_opts); const char *objfile, *path; struct bpf_program *prog; struct bpf_object *obj; struct bpf_link *link; - int err; + int err = -1, map_fd = -1; if (!REQ_ARGS(2)) usage(); @@ -21,10 +23,26 @@ static int do_pin(int argc, char **argv) objfile = GET_ARG(); path = GET_ARG(); + /* optional arguments */ + if (argc) { + if (is_prefix(*argv, "map")) { + NEXT_ARG(); + + if (!REQ_ARGS(2)) { + p_err("incorrect map spec"); + return -1; + } + + map_fd = map_parse_fd(&argc, &argv); + if (map_fd < 0) + return -1; + } + } + obj = bpf_object__open(objfile); if (IS_ERR(obj)) { p_err("can't open objfile %s", objfile); - return -1; + goto close_map_fd; } err = bpf_object__load(obj); @@ -39,7 +57,10 @@ static int do_pin(int argc, char **argv) goto close_obj; } - link = bpf_program__attach_iter(prog, NULL); + if (map_fd >= 0) + iter_opts.map_fd = map_fd; + + link = bpf_program__attach_iter(prog, &iter_opts); if (IS_ERR(link)) { err = PTR_ERR(link); p_err("attach_iter failed for program %s", @@ -62,14 +83,18 @@ close_link: bpf_link__destroy(link); close_obj: bpf_object__close(obj); +close_map_fd: + if (map_fd >= 0) + close(map_fd); return err; } static int do_help(int argc, char **argv) { fprintf(stderr, - "Usage: %1$s %2$s pin OBJ PATH\n" + "Usage: %1$s %2$s pin OBJ PATH [map MAP]\n" " %1$s %2$s help\n" + " " HELP_SPEC_MAP "\n" "", bin_name, "iter"); -- cgit v1.2.3