1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (C) 2020 Facebook */
11 #include "json_writer.h"
14 static const char * const link_type_name[] = {
15 [BPF_LINK_TYPE_UNSPEC] = "unspec",
16 [BPF_LINK_TYPE_RAW_TRACEPOINT] = "raw_tracepoint",
17 [BPF_LINK_TYPE_TRACING] = "tracing",
18 [BPF_LINK_TYPE_CGROUP] = "cgroup",
19 [BPF_LINK_TYPE_ITER] = "iter",
20 [BPF_LINK_TYPE_NETNS] = "netns",
23 static int link_parse_fd(int *argc, char ***argv)
27 if (is_prefix(**argv, "id")) {
33 id = strtoul(**argv, &endptr, 0);
35 p_err("can't parse %s as ID", **argv);
40 fd = bpf_link_get_fd_by_id(id);
42 p_err("failed to get link with ID %d: %s", id, strerror(errno));
44 } else if (is_prefix(**argv, "pinned")) {
52 return open_obj_pinned_any(path, BPF_OBJ_LINK);
55 p_err("expected 'id' or 'pinned', got: '%s'?", **argv);
60 show_link_header_json(struct bpf_link_info *info, json_writer_t *wtr)
62 jsonw_uint_field(wtr, "id", info->id);
63 if (info->type < ARRAY_SIZE(link_type_name))
64 jsonw_string_field(wtr, "type", link_type_name[info->type]);
66 jsonw_uint_field(wtr, "type", info->type);
68 jsonw_uint_field(json_wtr, "prog_id", info->prog_id);
71 static void show_link_attach_type_json(__u32 attach_type, json_writer_t *wtr)
73 if (attach_type < ARRAY_SIZE(attach_type_name))
74 jsonw_string_field(wtr, "attach_type",
75 attach_type_name[attach_type]);
77 jsonw_uint_field(wtr, "attach_type", attach_type);
80 static bool is_iter_map_target(const char *target_name)
82 return strcmp(target_name, "bpf_map_elem") == 0 ||
83 strcmp(target_name, "bpf_sk_storage_map") == 0;
86 static void show_iter_json(struct bpf_link_info *info, json_writer_t *wtr)
88 const char *target_name = u64_to_ptr(info->iter.target_name);
90 jsonw_string_field(wtr, "target_name", target_name);
92 if (is_iter_map_target(target_name))
93 jsonw_uint_field(wtr, "map_id", info->iter.map.map_id);
96 static int get_prog_info(int prog_id, struct bpf_prog_info *info)
98 __u32 len = sizeof(*info);
101 prog_fd = bpf_prog_get_fd_by_id(prog_id);
105 memset(info, 0, sizeof(*info));
106 err = bpf_obj_get_info_by_fd(prog_fd, info, &len);
108 p_err("can't get prog info: %s", strerror(errno));
113 static int show_link_close_json(int fd, struct bpf_link_info *info)
115 struct bpf_prog_info prog_info;
118 jsonw_start_object(json_wtr);
120 show_link_header_json(info, json_wtr);
122 switch (info->type) {
123 case BPF_LINK_TYPE_RAW_TRACEPOINT:
124 jsonw_string_field(json_wtr, "tp_name",
125 u64_to_ptr(info->raw_tracepoint.tp_name));
127 case BPF_LINK_TYPE_TRACING:
128 err = get_prog_info(info->prog_id, &prog_info);
132 if (prog_info.type < prog_type_name_size)
133 jsonw_string_field(json_wtr, "prog_type",
134 prog_type_name[prog_info.type]);
136 jsonw_uint_field(json_wtr, "prog_type",
139 show_link_attach_type_json(info->tracing.attach_type,
142 case BPF_LINK_TYPE_CGROUP:
143 jsonw_lluint_field(json_wtr, "cgroup_id",
144 info->cgroup.cgroup_id);
145 show_link_attach_type_json(info->cgroup.attach_type, json_wtr);
147 case BPF_LINK_TYPE_ITER:
148 show_iter_json(info, json_wtr);
150 case BPF_LINK_TYPE_NETNS:
151 jsonw_uint_field(json_wtr, "netns_ino",
152 info->netns.netns_ino);
153 show_link_attach_type_json(info->netns.attach_type, json_wtr);
159 if (!hash_empty(link_table.table)) {
160 struct pinned_obj *obj;
162 jsonw_name(json_wtr, "pinned");
163 jsonw_start_array(json_wtr);
164 hash_for_each_possible(link_table.table, obj, hash, info->id) {
165 if (obj->id == info->id)
166 jsonw_string(json_wtr, obj->path);
168 jsonw_end_array(json_wtr);
171 emit_obj_refs_json(&refs_table, info->id, json_wtr);
173 jsonw_end_object(json_wtr);
178 static void show_link_header_plain(struct bpf_link_info *info)
180 printf("%u: ", info->id);
181 if (info->type < ARRAY_SIZE(link_type_name))
182 printf("%s ", link_type_name[info->type]);
184 printf("type %u ", info->type);
186 printf("prog %u ", info->prog_id);
189 static void show_link_attach_type_plain(__u32 attach_type)
191 if (attach_type < ARRAY_SIZE(attach_type_name))
192 printf("attach_type %s ", attach_type_name[attach_type]);
194 printf("attach_type %u ", attach_type);
197 static void show_iter_plain(struct bpf_link_info *info)
199 const char *target_name = u64_to_ptr(info->iter.target_name);
201 printf("target_name %s ", target_name);
203 if (is_iter_map_target(target_name))
204 printf("map_id %u ", info->iter.map.map_id);
207 static int show_link_close_plain(int fd, struct bpf_link_info *info)
209 struct bpf_prog_info prog_info;
212 show_link_header_plain(info);
214 switch (info->type) {
215 case BPF_LINK_TYPE_RAW_TRACEPOINT:
216 printf("\n\ttp '%s' ",
217 (const char *)u64_to_ptr(info->raw_tracepoint.tp_name));
219 case BPF_LINK_TYPE_TRACING:
220 err = get_prog_info(info->prog_id, &prog_info);
224 if (prog_info.type < prog_type_name_size)
225 printf("\n\tprog_type %s ",
226 prog_type_name[prog_info.type]);
228 printf("\n\tprog_type %u ", prog_info.type);
230 show_link_attach_type_plain(info->tracing.attach_type);
232 case BPF_LINK_TYPE_CGROUP:
233 printf("\n\tcgroup_id %zu ", (size_t)info->cgroup.cgroup_id);
234 show_link_attach_type_plain(info->cgroup.attach_type);
236 case BPF_LINK_TYPE_ITER:
237 show_iter_plain(info);
239 case BPF_LINK_TYPE_NETNS:
240 printf("\n\tnetns_ino %u ", info->netns.netns_ino);
241 show_link_attach_type_plain(info->netns.attach_type);
247 if (!hash_empty(link_table.table)) {
248 struct pinned_obj *obj;
250 hash_for_each_possible(link_table.table, obj, hash, info->id) {
251 if (obj->id == info->id)
252 printf("\n\tpinned %s", obj->path);
255 emit_obj_refs_plain(&refs_table, info->id, "\n\tpids ");
262 static int do_show_link(int fd)
264 struct bpf_link_info info;
265 __u32 len = sizeof(info);
269 memset(&info, 0, sizeof(info));
271 err = bpf_obj_get_info_by_fd(fd, &info, &len);
273 p_err("can't get link info: %s",
278 if (info.type == BPF_LINK_TYPE_RAW_TRACEPOINT &&
279 !info.raw_tracepoint.tp_name) {
280 info.raw_tracepoint.tp_name = (unsigned long)&buf;
281 info.raw_tracepoint.tp_name_len = sizeof(buf);
284 if (info.type == BPF_LINK_TYPE_ITER &&
285 !info.iter.target_name) {
286 info.iter.target_name = (unsigned long)&buf;
287 info.iter.target_name_len = sizeof(buf);
292 show_link_close_json(fd, &info);
294 show_link_close_plain(fd, &info);
300 static int do_show(int argc, char **argv)
306 build_pinned_obj_table(&link_table, BPF_OBJ_LINK);
307 build_obj_refs_table(&refs_table, BPF_OBJ_LINK);
310 fd = link_parse_fd(&argc, &argv);
313 return do_show_link(fd);
320 jsonw_start_array(json_wtr);
322 err = bpf_link_get_next_id(id, &id);
326 p_err("can't get next link: %s%s", strerror(errno),
327 errno == EINVAL ? " -- kernel too old?" : "");
331 fd = bpf_link_get_fd_by_id(id);
335 p_err("can't get link by id (%u): %s",
336 id, strerror(errno));
340 err = do_show_link(fd);
345 jsonw_end_array(json_wtr);
347 delete_obj_refs_table(&refs_table);
349 return errno == ENOENT ? 0 : -1;
352 static int do_pin(int argc, char **argv)
356 err = do_pin_any(argc, argv, link_parse_fd);
357 if (!err && json_output)
358 jsonw_null(json_wtr);
362 static int do_detach(int argc, char **argv)
367 p_err("link specifier is invalid or missing\n");
371 fd = link_parse_fd(&argc, &argv);
375 err = bpf_link_detach(fd);
380 p_err("failed link detach: %s", strerror(-err));
385 jsonw_null(json_wtr);
390 static int do_help(int argc, char **argv)
393 jsonw_null(json_wtr);
398 "Usage: %1$s %2$s { show | list } [LINK]\n"
399 " %1$s %2$s pin LINK FILE\n"
400 " %1$s %2$s detach LINK\n"
403 " " HELP_SPEC_LINK "\n"
404 " " HELP_SPEC_OPTIONS "\n"
411 static const struct cmd cmds[] = {
416 { "detach", do_detach },
420 int do_link(int argc, char **argv)
422 return cmd_select(cmds, argc, argv, do_help);