| // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) |
| /* Copyright (C) 2020 Facebook */ |
| |
| #include <errno.h> |
| #include <linux/err.h> |
| #include <net/if.h> |
| #include <stdio.h> |
| #include <unistd.h> |
| |
| #include <bpf/bpf.h> |
| #include <bpf/hashmap.h> |
| |
| #include "json_writer.h" |
| #include "main.h" |
| |
| static const char * const link_type_name[] = { |
| [BPF_LINK_TYPE_UNSPEC] = "unspec", |
| [BPF_LINK_TYPE_RAW_TRACEPOINT] = "raw_tracepoint", |
| [BPF_LINK_TYPE_TRACING] = "tracing", |
| [BPF_LINK_TYPE_CGROUP] = "cgroup", |
| [BPF_LINK_TYPE_ITER] = "iter", |
| [BPF_LINK_TYPE_NETNS] = "netns", |
| [BPF_LINK_TYPE_XDP] = "xdp", |
| [BPF_LINK_TYPE_PERF_EVENT] = "perf_event", |
| [BPF_LINK_TYPE_KPROBE_MULTI] = "kprobe_multi", |
| }; |
| |
| static struct hashmap *link_table; |
| |
| static int link_parse_fd(int *argc, char ***argv) |
| { |
| int fd; |
| |
| if (is_prefix(**argv, "id")) { |
| unsigned int id; |
| char *endptr; |
| |
| NEXT_ARGP(); |
| |
| id = strtoul(**argv, &endptr, 0); |
| if (*endptr) { |
| p_err("can't parse %s as ID", **argv); |
| return -1; |
| } |
| NEXT_ARGP(); |
| |
| fd = bpf_link_get_fd_by_id(id); |
| if (fd < 0) |
| p_err("failed to get link with ID %d: %s", id, strerror(errno)); |
| return fd; |
| } else if (is_prefix(**argv, "pinned")) { |
| char *path; |
| |
| NEXT_ARGP(); |
| |
| path = **argv; |
| NEXT_ARGP(); |
| |
| return open_obj_pinned_any(path, BPF_OBJ_LINK); |
| } |
| |
| p_err("expected 'id' or 'pinned', got: '%s'?", **argv); |
| return -1; |
| } |
| |
| static void |
| show_link_header_json(struct bpf_link_info *info, json_writer_t *wtr) |
| { |
| jsonw_uint_field(wtr, "id", info->id); |
| if (info->type < ARRAY_SIZE(link_type_name)) |
| jsonw_string_field(wtr, "type", link_type_name[info->type]); |
| else |
| jsonw_uint_field(wtr, "type", info->type); |
| |
| jsonw_uint_field(json_wtr, "prog_id", info->prog_id); |
| } |
| |
| static void show_link_attach_type_json(__u32 attach_type, json_writer_t *wtr) |
| { |
| if (attach_type < ARRAY_SIZE(attach_type_name)) |
| jsonw_string_field(wtr, "attach_type", |
| attach_type_name[attach_type]); |
| else |
| jsonw_uint_field(wtr, "attach_type", attach_type); |
| } |
| |
| static bool is_iter_map_target(const char *target_name) |
| { |
| return strcmp(target_name, "bpf_map_elem") == 0 || |
| strcmp(target_name, "bpf_sk_storage_map") == 0; |
| } |
| |
| 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); |
| |
| jsonw_string_field(wtr, "target_name", target_name); |
| |
| if (is_iter_map_target(target_name)) |
| jsonw_uint_field(wtr, "map_id", info->iter.map.map_id); |
| } |
| |
| static int get_prog_info(int prog_id, struct bpf_prog_info *info) |
| { |
| __u32 len = sizeof(*info); |
| int err, prog_fd; |
| |
| prog_fd = bpf_prog_get_fd_by_id(prog_id); |
| if (prog_fd < 0) |
| return prog_fd; |
| |
| memset(info, 0, sizeof(*info)); |
| err = bpf_obj_get_info_by_fd(prog_fd, info, &len); |
| if (err) |
| p_err("can't get prog info: %s", strerror(errno)); |
| close(prog_fd); |
| return err; |
| } |
| |
| static int show_link_close_json(int fd, struct bpf_link_info *info) |
| { |
| struct bpf_prog_info prog_info; |
| int err; |
| |
| jsonw_start_object(json_wtr); |
| |
| show_link_header_json(info, json_wtr); |
| |
| switch (info->type) { |
| case BPF_LINK_TYPE_RAW_TRACEPOINT: |
| jsonw_string_field(json_wtr, "tp_name", |
| u64_to_ptr(info->raw_tracepoint.tp_name)); |
| break; |
| case BPF_LINK_TYPE_TRACING: |
| err = get_prog_info(info->prog_id, &prog_info); |
| if (err) |
| return err; |
| |
| if (prog_info.type < prog_type_name_size) |
| jsonw_string_field(json_wtr, "prog_type", |
| prog_type_name[prog_info.type]); |
| else |
| jsonw_uint_field(json_wtr, "prog_type", |
| prog_info.type); |
| |
| show_link_attach_type_json(info->tracing.attach_type, |
| json_wtr); |
| break; |
| case BPF_LINK_TYPE_CGROUP: |
| jsonw_lluint_field(json_wtr, "cgroup_id", |
| info->cgroup.cgroup_id); |
| show_link_attach_type_json(info->cgroup.attach_type, json_wtr); |
| break; |
| case BPF_LINK_TYPE_ITER: |
| show_iter_json(info, json_wtr); |
| break; |
| case BPF_LINK_TYPE_NETNS: |
| jsonw_uint_field(json_wtr, "netns_ino", |
| info->netns.netns_ino); |
| show_link_attach_type_json(info->netns.attach_type, json_wtr); |
| break; |
| default: |
| break; |
| } |
| |
| if (!hashmap__empty(link_table)) { |
| struct hashmap_entry *entry; |
| |
| jsonw_name(json_wtr, "pinned"); |
| jsonw_start_array(json_wtr); |
| hashmap__for_each_key_entry(link_table, entry, |
| u32_as_hash_field(info->id)) |
| jsonw_string(json_wtr, entry->value); |
| jsonw_end_array(json_wtr); |
| } |
| |
| emit_obj_refs_json(refs_table, info->id, json_wtr); |
| |
| jsonw_end_object(json_wtr); |
| |
| return 0; |
| } |
| |
| static void show_link_header_plain(struct bpf_link_info *info) |
| { |
| printf("%u: ", info->id); |
| if (info->type < ARRAY_SIZE(link_type_name)) |
| printf("%s ", link_type_name[info->type]); |
| else |
| printf("type %u ", info->type); |
| |
| printf("prog %u ", info->prog_id); |
| } |
| |
| static void show_link_attach_type_plain(__u32 attach_type) |
| { |
| if (attach_type < ARRAY_SIZE(attach_type_name)) |
| printf("attach_type %s ", attach_type_name[attach_type]); |
| else |
| printf("attach_type %u ", attach_type); |
| } |
| |
| static void show_iter_plain(struct bpf_link_info *info) |
| { |
| const char *target_name = u64_to_ptr(info->iter.target_name); |
| |
| printf("target_name %s ", target_name); |
| |
| if (is_iter_map_target(target_name)) |
| printf("map_id %u ", info->iter.map.map_id); |
| } |
| |
| static int show_link_close_plain(int fd, struct bpf_link_info *info) |
| { |
| struct bpf_prog_info prog_info; |
| int err; |
| |
| show_link_header_plain(info); |
| |
| switch (info->type) { |
| case BPF_LINK_TYPE_RAW_TRACEPOINT: |
| printf("\n\ttp '%s' ", |
| (const char *)u64_to_ptr(info->raw_tracepoint.tp_name)); |
| break; |
| case BPF_LINK_TYPE_TRACING: |
| err = get_prog_info(info->prog_id, &prog_info); |
| if (err) |
| return err; |
| |
| if (prog_info.type < prog_type_name_size) |
| printf("\n\tprog_type %s ", |
| prog_type_name[prog_info.type]); |
| else |
| printf("\n\tprog_type %u ", prog_info.type); |
| |
| show_link_attach_type_plain(info->tracing.attach_type); |
| break; |
| case BPF_LINK_TYPE_CGROUP: |
| printf("\n\tcgroup_id %zu ", (size_t)info->cgroup.cgroup_id); |
| show_link_attach_type_plain(info->cgroup.attach_type); |
| break; |
| case BPF_LINK_TYPE_ITER: |
| show_iter_plain(info); |
| break; |
| case BPF_LINK_TYPE_NETNS: |
| printf("\n\tnetns_ino %u ", info->netns.netns_ino); |
| show_link_attach_type_plain(info->netns.attach_type); |
| break; |
| default: |
| break; |
| } |
| |
| if (!hashmap__empty(link_table)) { |
| struct hashmap_entry *entry; |
| |
| hashmap__for_each_key_entry(link_table, entry, |
| u32_as_hash_field(info->id)) |
| printf("\n\tpinned %s", (char *)entry->value); |
| } |
| emit_obj_refs_plain(refs_table, info->id, "\n\tpids "); |
| |
| printf("\n"); |
| |
| return 0; |
| } |
| |
| static int do_show_link(int fd) |
| { |
| struct bpf_link_info info; |
| __u32 len = sizeof(info); |
| char buf[256]; |
| int err; |
| |
| memset(&info, 0, sizeof(info)); |
| again: |
| err = bpf_obj_get_info_by_fd(fd, &info, &len); |
| if (err) { |
| p_err("can't get link info: %s", |
| strerror(errno)); |
| close(fd); |
| return err; |
| } |
| if (info.type == BPF_LINK_TYPE_RAW_TRACEPOINT && |
| !info.raw_tracepoint.tp_name) { |
| info.raw_tracepoint.tp_name = (unsigned long)&buf; |
| info.raw_tracepoint.tp_name_len = sizeof(buf); |
| goto again; |
| } |
| if (info.type == BPF_LINK_TYPE_ITER && |
| !info.iter.target_name) { |
| info.iter.target_name = (unsigned long)&buf; |
| info.iter.target_name_len = sizeof(buf); |
| goto again; |
| } |
| |
| if (json_output) |
| show_link_close_json(fd, &info); |
| else |
| show_link_close_plain(fd, &info); |
| |
| close(fd); |
| return 0; |
| } |
| |
| static int do_show(int argc, char **argv) |
| { |
| __u32 id = 0; |
| int err, fd; |
| |
| if (show_pinned) { |
| link_table = hashmap__new(hash_fn_for_key_as_id, |
| equal_fn_for_key_as_id, NULL); |
| 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); |
| } |