496 lines
11 KiB
C
496 lines
11 KiB
C
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// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
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/* Copyright (C) 2020 Facebook */
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#include <errno.h>
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#include <linux/err.h>
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#include <net/if.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <bpf/bpf.h>
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#include <bpf/hashmap.h>
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#include "json_writer.h"
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#include "main.h"
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static struct hashmap *link_table;
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static int link_parse_fd(int *argc, char ***argv)
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{
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int fd;
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if (is_prefix(**argv, "id")) {
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unsigned int id;
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char *endptr;
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NEXT_ARGP();
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id = strtoul(**argv, &endptr, 0);
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if (*endptr) {
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p_err("can't parse %s as ID", **argv);
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return -1;
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}
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NEXT_ARGP();
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fd = bpf_link_get_fd_by_id(id);
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if (fd < 0)
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p_err("failed to get link with ID %d: %s", id, strerror(errno));
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return fd;
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} else if (is_prefix(**argv, "pinned")) {
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char *path;
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NEXT_ARGP();
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path = **argv;
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NEXT_ARGP();
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return open_obj_pinned_any(path, BPF_OBJ_LINK);
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}
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p_err("expected 'id' or 'pinned', got: '%s'?", **argv);
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return -1;
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}
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static void
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show_link_header_json(struct bpf_link_info *info, json_writer_t *wtr)
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{
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const char *link_type_str;
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jsonw_uint_field(wtr, "id", info->id);
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link_type_str = libbpf_bpf_link_type_str(info->type);
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if (link_type_str)
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jsonw_string_field(wtr, "type", link_type_str);
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else
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jsonw_uint_field(wtr, "type", info->type);
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jsonw_uint_field(json_wtr, "prog_id", info->prog_id);
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}
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static void show_link_attach_type_json(__u32 attach_type, json_writer_t *wtr)
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{
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const char *attach_type_str;
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attach_type_str = libbpf_bpf_attach_type_str(attach_type);
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if (attach_type_str)
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jsonw_string_field(wtr, "attach_type", attach_type_str);
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else
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jsonw_uint_field(wtr, "attach_type", attach_type);
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}
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static bool is_iter_map_target(const char *target_name)
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{
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return strcmp(target_name, "bpf_map_elem") == 0 ||
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strcmp(target_name, "bpf_sk_storage_map") == 0;
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}
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static bool is_iter_cgroup_target(const char *target_name)
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{
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return strcmp(target_name, "cgroup") == 0;
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}
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static const char *cgroup_order_string(__u32 order)
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{
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switch (order) {
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case BPF_CGROUP_ITER_ORDER_UNSPEC:
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return "order_unspec";
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case BPF_CGROUP_ITER_SELF_ONLY:
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return "self_only";
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case BPF_CGROUP_ITER_DESCENDANTS_PRE:
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return "descendants_pre";
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case BPF_CGROUP_ITER_DESCENDANTS_POST:
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return "descendants_post";
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case BPF_CGROUP_ITER_ANCESTORS_UP:
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return "ancestors_up";
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default: /* won't happen */
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return "unknown";
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}
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}
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static bool is_iter_task_target(const char *target_name)
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{
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return strcmp(target_name, "task") == 0 ||
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strcmp(target_name, "task_file") == 0 ||
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strcmp(target_name, "task_vma") == 0;
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}
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static void show_iter_json(struct bpf_link_info *info, json_writer_t *wtr)
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{
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const char *target_name = u64_to_ptr(info->iter.target_name);
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jsonw_string_field(wtr, "target_name", target_name);
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if (is_iter_map_target(target_name))
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jsonw_uint_field(wtr, "map_id", info->iter.map.map_id);
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else if (is_iter_task_target(target_name)) {
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if (info->iter.task.tid)
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jsonw_uint_field(wtr, "tid", info->iter.task.tid);
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else if (info->iter.task.pid)
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jsonw_uint_field(wtr, "pid", info->iter.task.pid);
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}
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if (is_iter_cgroup_target(target_name)) {
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jsonw_lluint_field(wtr, "cgroup_id", info->iter.cgroup.cgroup_id);
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jsonw_string_field(wtr, "order",
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cgroup_order_string(info->iter.cgroup.order));
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}
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}
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static int get_prog_info(int prog_id, struct bpf_prog_info *info)
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{
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__u32 len = sizeof(*info);
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int err, prog_fd;
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prog_fd = bpf_prog_get_fd_by_id(prog_id);
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if (prog_fd < 0)
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return prog_fd;
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memset(info, 0, sizeof(*info));
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err = bpf_obj_get_info_by_fd(prog_fd, info, &len);
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if (err)
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p_err("can't get prog info: %s", strerror(errno));
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close(prog_fd);
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return err;
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}
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static int show_link_close_json(int fd, struct bpf_link_info *info)
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{
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struct bpf_prog_info prog_info;
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const char *prog_type_str;
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int err;
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jsonw_start_object(json_wtr);
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show_link_header_json(info, json_wtr);
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switch (info->type) {
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case BPF_LINK_TYPE_RAW_TRACEPOINT:
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jsonw_string_field(json_wtr, "tp_name",
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u64_to_ptr(info->raw_tracepoint.tp_name));
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break;
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case BPF_LINK_TYPE_TRACING:
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err = get_prog_info(info->prog_id, &prog_info);
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if (err)
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return err;
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prog_type_str = libbpf_bpf_prog_type_str(prog_info.type);
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/* libbpf will return NULL for variants unknown to it. */
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if (prog_type_str)
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jsonw_string_field(json_wtr, "prog_type", prog_type_str);
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else
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jsonw_uint_field(json_wtr, "prog_type", prog_info.type);
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show_link_attach_type_json(info->tracing.attach_type,
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json_wtr);
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break;
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case BPF_LINK_TYPE_CGROUP:
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jsonw_lluint_field(json_wtr, "cgroup_id",
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info->cgroup.cgroup_id);
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show_link_attach_type_json(info->cgroup.attach_type, json_wtr);
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break;
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case BPF_LINK_TYPE_ITER:
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show_iter_json(info, json_wtr);
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break;
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case BPF_LINK_TYPE_NETNS:
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jsonw_uint_field(json_wtr, "netns_ino",
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info->netns.netns_ino);
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show_link_attach_type_json(info->netns.attach_type, json_wtr);
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break;
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default:
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break;
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}
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if (!hashmap__empty(link_table)) {
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struct hashmap_entry *entry;
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jsonw_name(json_wtr, "pinned");
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jsonw_start_array(json_wtr);
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hashmap__for_each_key_entry(link_table, entry,
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u32_as_hash_field(info->id))
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jsonw_string(json_wtr, entry->value);
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jsonw_end_array(json_wtr);
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}
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emit_obj_refs_json(refs_table, info->id, json_wtr);
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jsonw_end_object(json_wtr);
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return 0;
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}
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static void show_link_header_plain(struct bpf_link_info *info)
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{
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const char *link_type_str;
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printf("%u: ", info->id);
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link_type_str = libbpf_bpf_link_type_str(info->type);
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if (link_type_str)
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printf("%s ", link_type_str);
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else
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printf("type %u ", info->type);
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printf("prog %u ", info->prog_id);
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}
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static void show_link_attach_type_plain(__u32 attach_type)
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{
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const char *attach_type_str;
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attach_type_str = libbpf_bpf_attach_type_str(attach_type);
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if (attach_type_str)
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printf("attach_type %s ", attach_type_str);
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else
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printf("attach_type %u ", attach_type);
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}
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static void show_iter_plain(struct bpf_link_info *info)
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{
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const char *target_name = u64_to_ptr(info->iter.target_name);
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printf("target_name %s ", target_name);
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if (is_iter_map_target(target_name))
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printf("map_id %u ", info->iter.map.map_id);
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else if (is_iter_task_target(target_name)) {
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if (info->iter.task.tid)
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printf("tid %u ", info->iter.task.tid);
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else if (info->iter.task.pid)
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printf("pid %u ", info->iter.task.pid);
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}
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if (is_iter_cgroup_target(target_name)) {
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printf("cgroup_id %llu ", info->iter.cgroup.cgroup_id);
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printf("order %s ",
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cgroup_order_string(info->iter.cgroup.order));
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}
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}
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static int show_link_close_plain(int fd, struct bpf_link_info *info)
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{
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struct bpf_prog_info prog_info;
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const char *prog_type_str;
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int err;
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show_link_header_plain(info);
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switch (info->type) {
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case BPF_LINK_TYPE_RAW_TRACEPOINT:
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printf("\n\ttp '%s' ",
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(const char *)u64_to_ptr(info->raw_tracepoint.tp_name));
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break;
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case BPF_LINK_TYPE_TRACING:
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err = get_prog_info(info->prog_id, &prog_info);
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if (err)
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return err;
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prog_type_str = libbpf_bpf_prog_type_str(prog_info.type);
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/* libbpf will return NULL for variants unknown to it. */
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if (prog_type_str)
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printf("\n\tprog_type %s ", prog_type_str);
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else
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printf("\n\tprog_type %u ", prog_info.type);
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show_link_attach_type_plain(info->tracing.attach_type);
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break;
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case BPF_LINK_TYPE_CGROUP:
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printf("\n\tcgroup_id %zu ", (size_t)info->cgroup.cgroup_id);
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show_link_attach_type_plain(info->cgroup.attach_type);
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break;
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case BPF_LINK_TYPE_ITER:
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show_iter_plain(info);
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break;
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case BPF_LINK_TYPE_NETNS:
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printf("\n\tnetns_ino %u ", info->netns.netns_ino);
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show_link_attach_type_plain(info->netns.attach_type);
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break;
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default:
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break;
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}
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if (!hashmap__empty(link_table)) {
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struct hashmap_entry *entry;
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hashmap__for_each_key_entry(link_table, entry,
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u32_as_hash_field(info->id))
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printf("\n\tpinned %s", (char *)entry->value);
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}
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emit_obj_refs_plain(refs_table, info->id, "\n\tpids ");
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printf("\n");
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return 0;
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}
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static int do_show_link(int fd)
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{
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struct bpf_link_info info;
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__u32 len = sizeof(info);
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char buf[256];
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int err;
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memset(&info, 0, sizeof(info));
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again:
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err = bpf_obj_get_info_by_fd(fd, &info, &len);
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if (err) {
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p_err("can't get link info: %s",
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strerror(errno));
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close(fd);
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return err;
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}
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if (info.type == BPF_LINK_TYPE_RAW_TRACEPOINT &&
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!info.raw_tracepoint.tp_name) {
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info.raw_tracepoint.tp_name = (unsigned long)&buf;
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info.raw_tracepoint.tp_name_len = sizeof(buf);
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goto again;
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}
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if (info.type == BPF_LINK_TYPE_ITER &&
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!info.iter.target_name) {
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info.iter.target_name = (unsigned long)&buf;
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info.iter.target_name_len = sizeof(buf);
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goto again;
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}
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if (json_output)
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show_link_close_json(fd, &info);
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else
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show_link_close_plain(fd, &info);
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close(fd);
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return 0;
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}
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static int do_show(int argc, char **argv)
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{
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__u32 id = 0;
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int err, fd;
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if (show_pinned) {
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link_table = hashmap__new(hash_fn_for_key_as_id,
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equal_fn_for_key_as_id, NULL);
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if (IS_ERR(link_table)) {
|
||
|
|
p_err("failed to create hashmap for pinned paths");
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
build_pinned_obj_table(link_table, BPF_OBJ_LINK);
|
||
|
|
}
|
||
|
|
build_obj_refs_table(&refs_table, BPF_OBJ_LINK);
|
||
|
|
|
||
|
|
if (argc == 2) {
|
||
|
|
fd = link_parse_fd(&argc, &argv);
|
||
|
|
if (fd < 0)
|
||
|
|
return fd;
|
||
|
|
return do_show_link(fd);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (argc)
|
||
|
|
return BAD_ARG();
|
||
|
|
|
||
|
|
if (json_output)
|
||
|
|
jsonw_start_array(json_wtr);
|
||
|
|
while (true) {
|
||
|
|
err = bpf_link_get_next_id(id, &id);
|
||
|
|
if (err) {
|
||
|
|
if (errno == ENOENT)
|
||
|
|
break;
|
||
|
|
p_err("can't get next link: %s%s", strerror(errno),
|
||
|
|
errno == EINVAL ? " -- kernel too old?" : "");
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
fd = bpf_link_get_fd_by_id(id);
|
||
|
|
if (fd < 0) {
|
||
|
|
if (errno == ENOENT)
|
||
|
|
continue;
|
||
|
|
p_err("can't get link by id (%u): %s",
|
||
|
|
id, strerror(errno));
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
err = do_show_link(fd);
|
||
|
|
if (err)
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
if (json_output)
|
||
|
|
jsonw_end_array(json_wtr);
|
||
|
|
|
||
|
|
delete_obj_refs_table(refs_table);
|
||
|
|
|
||
|
|
if (show_pinned)
|
||
|
|
delete_pinned_obj_table(link_table);
|
||
|
|
|
||
|
|
return errno == ENOENT ? 0 : -1;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int do_pin(int argc, char **argv)
|
||
|
|
{
|
||
|
|
int err;
|
||
|
|
|
||
|
|
err = do_pin_any(argc, argv, link_parse_fd);
|
||
|
|
if (!err && json_output)
|
||
|
|
jsonw_null(json_wtr);
|
||
|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int do_detach(int argc, char **argv)
|
||
|
|
{
|
||
|
|
int err, fd;
|
||
|
|
|
||
|
|
if (argc != 2) {
|
||
|
|
p_err("link specifier is invalid or missing\n");
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
fd = link_parse_fd(&argc, &argv);
|
||
|
|
if (fd < 0)
|
||
|
|
return 1;
|
||
|
|
|
||
|
|
err = bpf_link_detach(fd);
|
||
|
|
if (err)
|
||
|
|
err = -errno;
|
||
|
|
close(fd);
|
||
|
|
if (err) {
|
||
|
|
p_err("failed link detach: %s", strerror(-err));
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (json_output)
|
||
|
|
jsonw_null(json_wtr);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int do_help(int argc, char **argv)
|
||
|
|
{
|
||
|
|
if (json_output) {
|
||
|
|
jsonw_null(json_wtr);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
fprintf(stderr,
|
||
|
|
"Usage: %1$s %2$s { show | list } [LINK]\n"
|
||
|
|
" %1$s %2$s pin LINK FILE\n"
|
||
|
|
" %1$s %2$s detach LINK\n"
|
||
|
|
" %1$s %2$s help\n"
|
||
|
|
"\n"
|
||
|
|
" " HELP_SPEC_LINK "\n"
|
||
|
|
" " HELP_SPEC_OPTIONS " |\n"
|
||
|
|
" {-f|--bpffs} | {-n|--nomount} }\n"
|
||
|
|
"",
|
||
|
|
bin_name, argv[-2]);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static const struct cmd cmds[] = {
|
||
|
|
{ "show", do_show },
|
||
|
|
{ "list", do_show },
|
||
|
|
{ "help", do_help },
|
||
|
|
{ "pin", do_pin },
|
||
|
|
{ "detach", do_detach },
|
||
|
|
{ 0 }
|
||
|
|
};
|
||
|
|
|
||
|
|
int do_link(int argc, char **argv)
|
||
|
|
{
|
||
|
|
return cmd_select(cmds, argc, argv, do_help);
|
||
|
|
}
|