From 831a0aafe5c39405150d47994fe0a5bcd78fbadc Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Mon, 23 Oct 2017 09:24:11 -0700 Subject: [PATCH] tools: bpftool: add JSON output for `bpftool map *` commands Reuse the json_writer API introduced in an earlier commit to make bpftool able to generate JSON output on `bpftool map { show | dump | lookup | getnext }` commands. Remaining commands produce no output. Some functions have been spit into plain-output and JSON versions in order to remain readable. Outputs for sample maps have been successfully tested against a JSON validator. Signed-off-by: Quentin Monnet Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- tools/bpf/bpftool/map.c | 149 ++++++++++++++++++++++++++++++++++------ 1 file changed, 129 insertions(+), 20 deletions(-) diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index e1004d825392..14d89bfabc66 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -205,8 +205,45 @@ map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len) return fd; } -static void print_entry(struct bpf_map_info *info, unsigned char *key, - unsigned char *value) +static void print_entry_json(struct bpf_map_info *info, unsigned char *key, + unsigned char *value) +{ + jsonw_start_object(json_wtr); + + if (!map_is_per_cpu(info->type)) { + jsonw_name(json_wtr, "key"); + print_hex_data_json(key, info->key_size); + jsonw_name(json_wtr, "value"); + print_hex_data_json(value, info->value_size); + } else { + unsigned int i, n; + + n = get_possible_cpus(); + + jsonw_name(json_wtr, "key"); + print_hex_data_json(key, info->key_size); + + jsonw_name(json_wtr, "values"); + jsonw_start_array(json_wtr); + for (i = 0; i < n; i++) { + jsonw_start_object(json_wtr); + + jsonw_int_field(json_wtr, "cpu", i); + + jsonw_name(json_wtr, "value"); + print_hex_data_json(value + i * info->value_size, + info->value_size); + + jsonw_end_object(json_wtr); + } + jsonw_end_array(json_wtr); + } + + jsonw_end_object(json_wtr); +} + +static void print_entry_plain(struct bpf_map_info *info, unsigned char *key, + unsigned char *value) { if (!map_is_per_cpu(info->type)) { bool single_line, break_names; @@ -370,7 +407,41 @@ static int parse_elem(char **argv, struct bpf_map_info *info, return -1; } -static int show_map_close(int fd, struct bpf_map_info *info) +static int show_map_close_json(int fd, struct bpf_map_info *info) +{ + char *memlock; + + memlock = get_fdinfo(fd, "memlock"); + close(fd); + + jsonw_start_object(json_wtr); + + jsonw_uint_field(json_wtr, "id", info->id); + if (info->type < ARRAY_SIZE(map_type_name)) + jsonw_string_field(json_wtr, "type", + map_type_name[info->type]); + else + jsonw_uint_field(json_wtr, "type", info->type); + + if (*info->name) + jsonw_string_field(json_wtr, "name", info->name); + + jsonw_name(json_wtr, "flags"); + jsonw_printf(json_wtr, "%#x", info->map_flags); + jsonw_uint_field(json_wtr, "bytes_key", info->key_size); + jsonw_uint_field(json_wtr, "bytes_value", info->value_size); + jsonw_uint_field(json_wtr, "max_entries", info->max_entries); + + if (memlock) + jsonw_int_field(json_wtr, "bytes_memlock", atoi(memlock)); + free(memlock); + + jsonw_end_object(json_wtr); + + return 0; +} + +static int show_map_close_plain(int fd, struct bpf_map_info *info) { char *memlock; @@ -412,12 +483,17 @@ static int do_show(int argc, char **argv) if (fd < 0) return -1; - return show_map_close(fd, &info); + if (json_output) + return show_map_close_json(fd, &info); + else + return show_map_close_plain(fd, &info); } if (argc) return BAD_ARG(); + if (json_output) + jsonw_start_array(json_wtr); while (true) { err = bpf_map_get_next_id(id, &id); if (err) { @@ -443,8 +519,13 @@ static int do_show(int argc, char **argv) return -1; } - show_map_close(fd, &info); + if (json_output) + show_map_close_json(fd, &info); + else + show_map_close_plain(fd, &info); } + if (json_output) + jsonw_end_array(json_wtr); return errno == ENOENT ? 0 : -1; } @@ -480,6 +561,8 @@ static int do_dump(int argc, char **argv) } prev_key = NULL; + if (json_output) + jsonw_start_array(json_wtr); while (true) { err = bpf_map_get_next_key(fd, prev_key, key); if (err) { @@ -489,7 +572,10 @@ static int do_dump(int argc, char **argv) } if (!bpf_map_lookup_elem(fd, key, value)) { - print_entry(&info, key, value); + if (json_output) + print_entry_json(&info, key, value); + else + print_entry_plain(&info, key, value); } else { info("can't lookup element with key: "); fprint_hex(stderr, key, info.key_size, " "); @@ -500,7 +586,11 @@ static int do_dump(int argc, char **argv) num_elems++; } - printf("Found %u element%s\n", num_elems, num_elems != 1 ? "s" : ""); + if (json_output) + jsonw_end_array(json_wtr); + else + printf("Found %u element%s\n", num_elems, + num_elems != 1 ? "s" : ""); exit_free: free(key); @@ -584,11 +674,18 @@ static int do_lookup(int argc, char **argv) err = bpf_map_lookup_elem(fd, key, value); if (!err) { - print_entry(&info, key, value); + if (json_output) + print_entry_json(&info, key, value); + else + print_entry_plain(&info, key, value); } else if (errno == ENOENT) { - printf("key:\n"); - fprint_hex(stdout, key, info.key_size, " "); - printf("\n\nNot found\n"); + if (json_output) { + jsonw_null(json_wtr); + } else { + printf("key:\n"); + fprint_hex(stdout, key, info.key_size, " "); + printf("\n\nNot found\n"); + } } else { err("lookup failed: %s\n", strerror(errno)); } @@ -640,18 +737,30 @@ static int do_getnext(int argc, char **argv) goto exit_free; } - if (key) { - printf("key:\n"); - fprint_hex(stdout, key, info.key_size, " "); - printf("\n"); + if (json_output) { + jsonw_start_object(json_wtr); + if (key) { + jsonw_name(json_wtr, "key"); + print_hex_data_json(key, info.key_size); + } else { + jsonw_null_field(json_wtr, "key"); + } + jsonw_name(json_wtr, "next_key"); + print_hex_data_json(nextkey, info.key_size); + jsonw_end_object(json_wtr); } else { - printf("key: None\n"); + if (key) { + printf("key:\n"); + fprint_hex(stdout, key, info.key_size, " "); + printf("\n"); + } else { + printf("key: None\n"); + } + printf("next key:\n"); + fprint_hex(stdout, nextkey, info.key_size, " "); + printf("\n"); } - printf("next key:\n"); - fprint_hex(stdout, nextkey, info.key_size, " "); - printf("\n"); - exit_free: free(nextkey); free(key); -- 2.45.2