From 6f95de6d713130c953af0a40b13c1da519f91c4e Mon Sep 17 00:00:00 2001 From: Hao Luo Date: Mon, 29 Aug 2022 16:18:28 -0700 Subject: bpftool: Add support for querying cgroup_iter link Support dumping info of a cgroup_iter link. This includes showing the cgroup's id and the order for walking the cgroup hierarchy. Example output is as follows: > bpftool link show 1: iter prog 2 target_name bpf_map 2: iter prog 3 target_name bpf_prog 3: iter prog 12 target_name cgroup cgroup_id 72 order self_only > bpftool -p link show [{ "id": 1, "type": "iter", "prog_id": 2, "target_name": "bpf_map" },{ "id": 2, "type": "iter", "prog_id": 3, "target_name": "bpf_prog" },{ "id": 3, "type": "iter", "prog_id": 12, "target_name": "cgroup", "cgroup_id": 72, "order": "self_only" } ] Signed-off-by: Hao Luo Reviewed-by: Quentin Monnet Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20220829231828.1016835-1-haoluo@google.com Signed-off-by: Martin KaFai Lau --- tools/bpf/bpftool/link.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c index 7a20931c3250..ef0dc2f8d5a2 100644 --- a/tools/bpf/bpftool/link.c +++ b/tools/bpf/bpftool/link.c @@ -83,6 +83,29 @@ static bool is_iter_map_target(const char *target_name) strcmp(target_name, "bpf_sk_storage_map") == 0; } +static bool is_iter_cgroup_target(const char *target_name) +{ + return strcmp(target_name, "cgroup") == 0; +} + +static const char *cgroup_order_string(__u32 order) +{ + switch (order) { + case BPF_CGROUP_ITER_ORDER_UNSPEC: + return "order_unspec"; + case BPF_CGROUP_ITER_SELF_ONLY: + return "self_only"; + case BPF_CGROUP_ITER_DESCENDANTS_PRE: + return "descendants_pre"; + case BPF_CGROUP_ITER_DESCENDANTS_POST: + return "descendants_post"; + case BPF_CGROUP_ITER_ANCESTORS_UP: + return "ancestors_up"; + default: /* won't happen */ + return "unknown"; + } +} + static void show_iter_json(struct bpf_link_info *info, json_writer_t *wtr) { const char *target_name = u64_to_ptr(info->iter.target_name); @@ -91,6 +114,12 @@ static void show_iter_json(struct bpf_link_info *info, json_writer_t *wtr) if (is_iter_map_target(target_name)) jsonw_uint_field(wtr, "map_id", info->iter.map.map_id); + + if (is_iter_cgroup_target(target_name)) { + jsonw_lluint_field(wtr, "cgroup_id", info->iter.cgroup.cgroup_id); + jsonw_string_field(wtr, "order", + cgroup_order_string(info->iter.cgroup.order)); + } } static int get_prog_info(int prog_id, struct bpf_prog_info *info) @@ -208,6 +237,12 @@ static void show_iter_plain(struct bpf_link_info *info) if (is_iter_map_target(target_name)) printf("map_id %u ", info->iter.map.map_id); + + if (is_iter_cgroup_target(target_name)) { + printf("cgroup_id %llu ", info->iter.cgroup.cgroup_id); + printf("order %s ", + cgroup_order_string(info->iter.cgroup.order)); + } } static int show_link_close_plain(int fd, struct bpf_link_info *info) -- cgit v1.2.3