diff options
author | Kui-Feng Lee <thinker.li@gmail.com> | 2023-04-20 03:28:21 +0300 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2023-04-21 21:10:10 +0300 |
commit | 0232b788978652571c4f4e57dc26ff8e4837926a (patch) | |
tree | 96f9779db401ce754b781c8bd47eda57cacd4c24 /tools/bpf/bpftool/struct_ops.c | |
parent | 833d67ecdc5f35f1ebf59d0fccc1ce771434be9c (diff) | |
download | linux-0232b788978652571c4f4e57dc26ff8e4837926a.tar.xz |
bpftool: Register struct_ops with a link.
You can include an optional path after specifying the object name for the
'struct_ops register' subcommand.
Since the commit 226bc6ae6405 ("Merge branch 'Transit between BPF TCP
congestion controls.'") has been accepted, it is now possible to create a
link for a struct_ops. This can be done by defining a struct_ops in
SEC(".struct_ops.link") to make libbpf returns a real link. If we don't pin
the links before leaving bpftool, they will disappear. To instruct bpftool
to pin the links in a directory with the names of the maps, we need to
provide the path of that directory.
Signed-off-by: Kui-Feng Lee <kuifeng@meta.com>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/r/20230420002822.345222-1-kuifeng@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/bpf/bpftool/struct_ops.c')
-rw-r--r-- | tools/bpf/bpftool/struct_ops.c | 70 |
1 files changed, 58 insertions, 12 deletions
diff --git a/tools/bpf/bpftool/struct_ops.c b/tools/bpf/bpftool/struct_ops.c index b389f4830e11..57c3da70aa31 100644 --- a/tools/bpf/bpftool/struct_ops.c +++ b/tools/bpf/bpftool/struct_ops.c @@ -475,21 +475,44 @@ static int do_unregister(int argc, char **argv) return cmd_retval(&res, true); } +static int pin_link(struct bpf_link *link, const char *pindir, + const char *name) +{ + char pinfile[PATH_MAX]; + int err; + + err = pathname_concat(pinfile, sizeof(pinfile), pindir, name); + if (err) + return -1; + + return bpf_link__pin(link, pinfile); +} + static int do_register(int argc, char **argv) { LIBBPF_OPTS(bpf_object_open_opts, open_opts); + __u32 link_info_len = sizeof(struct bpf_link_info); + struct bpf_link_info link_info = {}; struct bpf_map_info info = {}; __u32 info_len = sizeof(info); int nr_errs = 0, nr_maps = 0; + const char *linkdir = NULL; struct bpf_object *obj; struct bpf_link *link; struct bpf_map *map; const char *file; - if (argc != 1) + if (argc != 1 && argc != 2) usage(); file = GET_ARG(); + if (argc == 1) + linkdir = GET_ARG(); + + if (linkdir && mount_bpffs_for_pin(linkdir)) { + p_err("can't mount bpffs for pinning"); + return -1; + } if (verifier_logs) /* log_level1 + log_level2 + stats, but not stable UAPI */ @@ -519,21 +542,44 @@ static int do_register(int argc, char **argv) } nr_maps++; - bpf_link__disconnect(link); - bpf_link__destroy(link); - - if (!bpf_map_get_info_by_fd(bpf_map__fd(map), &info, - &info_len)) - p_info("Registered %s %s id %u", - get_kern_struct_ops_name(&info), - bpf_map__name(map), - info.id); - else + if (bpf_map_get_info_by_fd(bpf_map__fd(map), &info, + &info_len)) { /* Not p_err. The struct_ops was attached * successfully. */ p_info("Registered %s but can't find id: %s", bpf_map__name(map), strerror(errno)); + goto clean_link; + } + if (!(bpf_map__map_flags(map) & BPF_F_LINK)) { + p_info("Registered %s %s id %u", + get_kern_struct_ops_name(&info), + info.name, + info.id); + goto clean_link; + } + if (bpf_link_get_info_by_fd(bpf_link__fd(link), + &link_info, + &link_info_len)) { + p_err("Registered %s but can't find link id: %s", + bpf_map__name(map), strerror(errno)); + nr_errs++; + goto clean_link; + } + if (linkdir && pin_link(link, linkdir, info.name)) { + p_err("can't pin link %u for %s: %s", + link_info.id, info.name, + strerror(errno)); + nr_errs++; + goto clean_link; + } + p_info("Registered %s %s map id %u link id %u", + get_kern_struct_ops_name(&info), + info.name, info.id, link_info.id); + +clean_link: + bpf_link__disconnect(link); + bpf_link__destroy(link); } bpf_object__close(obj); @@ -562,7 +608,7 @@ static int do_help(int argc, char **argv) fprintf(stderr, "Usage: %1$s %2$s { show | list } [STRUCT_OPS_MAP]\n" " %1$s %2$s dump [STRUCT_OPS_MAP]\n" - " %1$s %2$s register OBJ\n" + " %1$s %2$s register OBJ [LINK_DIR]\n" " %1$s %2$s unregister STRUCT_OPS_MAP\n" " %1$s %2$s help\n" "\n" |