diff options
| -rw-r--r-- | tools/bpf/bpftool/map.c | 217 |
1 files changed, 201 insertions, 16 deletions
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index e2baec1122fb..9c8191845585 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -34,6 +34,7 @@ #include <assert.h> #include <errno.h> #include <fcntl.h> +#include <linux/err.h> #include <stdbool.h> #include <stdio.h> #include <stdlib.h> @@ -44,6 +45,8 @@ #include <bpf.h> +#include "btf.h" +#include "json_writer.h" #include "main.h" static const char * const map_type_name[] = { @@ -148,8 +151,109 @@ int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len) return fd; } +static int do_dump_btf(const struct btf_dumper *d, + struct bpf_map_info *map_info, void *key, + void *value) +{ + int ret; + + /* start of key-value pair */ + jsonw_start_object(d->jw); + + jsonw_name(d->jw, "key"); + + ret = btf_dumper_type(d, map_info->btf_key_type_id, key); + if (ret) + goto err_end_obj; + + jsonw_name(d->jw, "value"); + + ret = btf_dumper_type(d, map_info->btf_value_type_id, value); + +err_end_obj: + /* end of key-value pair */ + jsonw_end_object(d->jw); + + return ret; +} + +static int get_btf(struct bpf_map_info *map_info, struct btf **btf) +{ + struct bpf_btf_info btf_info = { 0 }; + __u32 len = sizeof(btf_info); + __u32 last_size; + int btf_fd; + void *ptr; + int err; + + err = 0; + *btf = NULL; + btf_fd = bpf_btf_get_fd_by_id(map_info->btf_id); + if (btf_fd < 0) + return 0; + + /* we won't know btf_size until we call bpf_obj_get_info_by_fd(). so + * let's start with a sane default - 4KiB here - and resize it only if + * bpf_obj_get_info_by_fd() needs a bigger buffer. + */ + btf_info.btf_size = 4096; + last_size = btf_info.btf_size; + ptr = malloc(last_size); + if (!ptr) { + err = -ENOMEM; + goto exit_free; + } + + bzero(ptr, last_size); + btf_info.btf = ptr_to_u64(ptr); + err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); + + if (!err && btf_info.btf_size > last_size) { + void *temp_ptr; + + last_size = btf_info.btf_size; + temp_ptr = realloc(ptr, last_size); + if (!temp_ptr) { + err = -ENOMEM; + goto exit_free; + } + ptr = temp_ptr; + bzero(ptr, last_size); + btf_info.btf = ptr_to_u64(ptr); + err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); + } + + if (err || btf_info.btf_size > last_size) { + err = errno; + goto exit_free; + } + + *btf = btf__new((__u8 *)btf_info.btf, btf_info.btf_size, NULL); + if (IS_ERR(*btf)) { + err = PTR_ERR(btf); + *btf = NULL; + } + +exit_free: + close(btf_fd); + free(ptr); + + return err; +} + +static json_writer_t *get_btf_writer(void) +{ + json_writer_t *jw = jsonw_new(stdout); + + if (!jw) + return NULL; + jsonw_pretty(jw, true); + + return jw; +} + static void print_entry_json(struct bpf_map_info *info, unsigned char *key, - unsigned char *value) + unsigned char *value, struct btf *btf) { jsonw_start_object(json_wtr); @@ -158,6 +262,16 @@ static void print_entry_json(struct bpf_map_info *info, unsigned char *key, print_hex_data_json(key, info->key_size); jsonw_name(json_wtr, "value"); print_hex_data_json(value, info->value_size); + if (btf) { + struct btf_dumper d = { + .btf = btf, + .jw = json_wtr, + .is_plain_text = false, + }; + + jsonw_name(json_wtr, "formatted"); + do_dump_btf(&d, info, key, value); + } } else { unsigned int i, n; @@ -508,10 +622,12 @@ static int do_show(int argc, char **argv) static int do_dump(int argc, char **argv) { + struct bpf_map_info info = {}; void *key, *value, *prev_key; unsigned int num_elems = 0; - struct bpf_map_info info = {}; __u32 len = sizeof(info); + json_writer_t *btf_wtr; + struct btf *btf = NULL; int err; int fd; @@ -537,8 +653,27 @@ static int do_dump(int argc, char **argv) } prev_key = NULL; + + err = get_btf(&info, &btf); + if (err) { + p_err("failed to get btf"); + goto exit_free; + } + if (json_output) jsonw_start_array(json_wtr); + else + if (btf) { + btf_wtr = get_btf_writer(); + if (!btf_wtr) { + p_info("failed to create json writer for btf. falling back to plain output"); + btf__free(btf); + btf = NULL; + } else { + jsonw_start_array(btf_wtr); + } + } + while (true) { err = bpf_map_get_next_key(fd, prev_key, key); if (err) { @@ -549,9 +684,19 @@ static int do_dump(int argc, char **argv) if (!bpf_map_lookup_elem(fd, key, value)) { if (json_output) - print_entry_json(&info, key, value); + print_entry_json(&info, key, value, btf); else - print_entry_plain(&info, key, value); + if (btf) { + struct btf_dumper d = { + .btf = btf, + .jw = btf_wtr, + .is_plain_text = true, + }; + + do_dump_btf(&d, &info, key, value); + } else { + print_entry_plain(&info, key, value); + } } else { if (json_output) { jsonw_name(json_wtr, "key"); @@ -574,14 +719,19 @@ static int do_dump(int argc, char **argv) if (json_output) jsonw_end_array(json_wtr); - else + else if (btf) { + jsonw_end_array(btf_wtr); + jsonw_destroy(&btf_wtr); + } else { printf("Found %u element%s\n", num_elems, num_elems != 1 ? "s" : ""); + } exit_free: free(key); free(value); close(fd); + btf__free(btf); return err; } @@ -637,6 +787,8 @@ static int do_lookup(int argc, char **argv) { struct bpf_map_info info = {}; __u32 len = sizeof(info); + json_writer_t *btf_wtr; + struct btf *btf = NULL; void *key, *value; int err; int fd; @@ -661,27 +813,60 @@ static int do_lookup(int argc, char **argv) goto exit_free; err = bpf_map_lookup_elem(fd, key, value); - if (!err) { - if (json_output) - print_entry_json(&info, key, value); - else + if (err) { + if (errno == ENOENT) { + if (json_output) { + jsonw_null(json_wtr); + } else { + printf("key:\n"); + fprint_hex(stdout, key, info.key_size, " "); + printf("\n\nNot found\n"); + } + } else { + p_err("lookup failed: %s", strerror(errno)); + } + + goto exit_free; + } + + /* here means bpf_map_lookup_elem() succeeded */ + err = get_btf(&info, &btf); + if (err) { + p_err("failed to get btf"); + goto exit_free; + } + + if (json_output) { + print_entry_json(&info, key, value, btf); + } else if (btf) { + /* if here json_wtr wouldn't have been initialised, + * so let's create separate writer for btf + */ + btf_wtr = get_btf_writer(); + if (!btf_wtr) { + p_info("failed to create json writer for btf. falling back to plain output"); + btf__free(btf); + btf = NULL; print_entry_plain(&info, key, value); - } else if (errno == ENOENT) { - if (json_output) { - jsonw_null(json_wtr); } else { - printf("key:\n"); - fprint_hex(stdout, key, info.key_size, " "); - printf("\n\nNot found\n"); + struct btf_dumper d = { + .btf = btf, + .jw = btf_wtr, + .is_plain_text = true, + }; + + do_dump_btf(&d, &info, key, value); + jsonw_destroy(&btf_wtr); } } else { - p_err("lookup failed: %s", strerror(errno)); + print_entry_plain(&info, key, value); } exit_free: free(key); free(value); close(fd); + btf__free(btf); return err; } |