path: root/tools/bpf/bpftool/map.c

// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright (C) 2017-2018 Netronome Systems, Inc. */

#include <errno.h>
#include <fcntl.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <net/if.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>

#include <bpf/bpf.h>
#include <bpf/btf.h>
#include <bpf/hashmap.h>

#include "json_writer.h"
#include "main.h"

static struct hashmap *map_table;

static bool map_is_per_cpu(__u32 type)
{
	return type == BPF_MAP_TYPE_PERCPU_HASH ||
	       type == BPF_MAP_TYPE_PERCPU_ARRAY ||
	       type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
	       type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE;
}

static bool map_is_map_of_maps(__u32 type)
{
	return type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
	       type == BPF_MAP_TYPE_HASH_OF_MAPS;
}

static bool map_is_map_of_progs(__u32 type)
{
	return type == BPF_MAP_TYPE_PROG_ARRAY;
}

static int map_type_from_str(const char *type)
{
	const char *map_type_str;
	unsigned int i;

	for (i = 0; ; i++) {
		map_type_str = libbpf_bpf_map_type_str(i);
		if (!map_type_str)
			break;

		/* Don't allow prefixing in case of possible future shadowing */
		if (!strcmp(map_type_str, type))
			return i;
	}
	return -1;
}

static void *alloc_value(struct bpf_map_info *info)
{
	if (map_is_per_cpu(info->type))
		return malloc(round_up(info->value_size, 8) *
			      get_possible_cpus());
	else
		return malloc(info->value_size);
}

static int do_dump_btf(const struct btf_dumper *d,
		       struct bpf_map_info *map_info, void *key,
		       void *value)
{
	__u32 value_id;
	int ret = 0;

	/* start of key-value pair */
	jsonw_start_object(d->jw);

	if (map_info->btf_key_type_id) {
		jsonw_name(d->jw, "key");

		ret = btf_dumper_type(d, map_info->btf_key_type_id, key);
		if (ret)
			goto err_end_obj;
	}

	value_id = map_info->btf_vmlinux_value_type_id ?
		: map_info->btf_value_type_id;

	if (!map_is_per_cpu(map_info->type)) {
		jsonw_name(d->jw, "value");
		ret = btf_dumper_type(d, value_id, value);
	} else {
		unsigned int i, n, step;

		jsonw_name(d->jw, "values");
		jsonw_start_array(d->jw);
		n = get_possible_cpus();
		step = round_up(map_info->value_size, 8);
		for (i = 0; i < n; i++) {
			jsonw_start_object(d->jw);
			jsonw_int_field(d->jw, "cpu", i);
			jsonw_name(d->jw, "value");
			ret = btf_dumper_type(d, value_id, value + i * step);
			jsonw_end_object(d->jw);
			if (ret)
				break;
		}
		jsonw_end_array(d->jw);
	}

err_end_obj:
	/* end of key-value pair */
	jsonw_end_object(d->jw);

	return ret;
}

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, struct btf *btf)
{
	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);
		if (map_is_map_of_maps(info->type))
			jsonw_uint_field(json_wtr, "inner_map_id",
					 *(unsigned int *)value);
		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, step;

		n = get_possible_cpus();
		step = round_up(info->value_size, 8);

		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 * step,
					    info->value_size);

			jsonw_end_object(json_wtr);
		}
		jsonw_end_array(json_wtr);
		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);
		}
	}

	jsonw_end_object(json_wtr);
}

static void
print_entry_error_msg(struct bpf_map_info *info, unsigned char *key,
		      const char *error_msg)
{
	int msg_size = strlen(error_msg);
	bool single_line, break_names;

	break_names = info->key_size > 16 || msg_size > 16;
	single_line = info->key_size + msg_size <= 24 && !break_names;

	printf("key:%c", break_names ? '\n' : ' ');
	fprint_hex(stdout, key, info->key_size, " ");

	printf(single_line ? "  " : "\n");

	printf("value:%c%s", break_names ? '\n' : ' ', error_msg);

	printf("\n");
}

static void
print_entry_error(struct bpf_map_info *map_info, void *key, int lookup_errno)
{
	/* For prog_array maps or arrays of maps, failure to lookup the value
	 * means there is no entry for that key. Do not print an error message
	 * in that case.
	 */
	if ((map_is_map_of_maps(map_info->type) ||
	     map_is_map_of_progs(map_info->type)) && lookup_errno == ENOENT)
		return;

	if (json_output) {
		jsonw_start_object(json_wtr);	/* entry */
		jsonw_name(json_wtr, "key");
		print_hex_data_json(key, map_info->key_size);
		jsonw_name(json_wtr, "value");
		jsonw_start_object(json_wtr);	/* error */
		jsonw_string_field(json_wtr, "error", strerror(lookup_errno));
		jsonw_end_object(json_wtr);	/* error */
		jsonw_end_object(json_wtr);	/* entry */
	} else {
		const char *msg = NULL;

		if (lookup_errno == ENOENT)
			msg = "<no entry>";
		else if (lookup_errno == ENOSPC &&
			 map_info->type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY)
			msg = "<cannot read>";

		print_entry_error_msg(map_info, key,
				      msg ? : strerror(lookup_errno));
	}
}

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;

		break_names = info->key_size > 16 || info->value_size > 16;
		single_line = info->key_size + info->value_size <= 24 &&
			!break_names;

		if (info->key_size) {
			printf("key:%c", break_names ? '\n' : ' ');
			fprint_hex(stdout, key, info->key_size, " ");

			printf(single_line ? "  " : "\n");
		}

		if (info->value_size) {
			if (map_is_map_of_maps(info->type)) {
				printf("inner_map_id:%c", break_names ? '\n' : ' ');
				printf("%u ", *(unsigned int *)value);
			} else {
				printf("value:%c", break_names ? '\n' : ' ');
				fprint_hex(stdout, value, info->value_size, " ");
			}
		}

		printf("\n");
	} else {
		unsigned int i, n, step;

		n = get_possible_cpus();
		step = round_up(info->value_size, 8);

		if (info->key_size) {
			printf("key:\n");
			fprint_hex(stdout, key, info->key_size, " ");
			printf("\n");
		}
		if (info->value_size) {
			for (i = 0; i < n; i++) {
				printf("value (CPU %02u):%c",
				       i, info->value_size > 16 ? '\n' : ' ');
				fprint_hex(stdout, value + i * step,
					   info->value_size, " ");
				printf("\n");
			}
		}
	}
}

static char **parse_bytes(char **argv, const char *name, unsigned char *val,
			  unsigned int n)
{
	unsigned int i = 0, base = 0;
	char *endptr;

	if (is_prefix(*argv, "hex")) {
		base = 16;
		argv++;
	}

	while (i < n && argv[i]) {
		val[i] = strtoul(argv[i], &endptr, base);
		if (*endptr) {
			p_err("error parsing byte: %s", argv[i]);
			return NULL;
		}
		i++;
	}

	if (i != n) {
		p_err("%s expected %u bytes got %u", name, n, i);
		return NULL;
	}

	return argv + i;
}

/* on per cpu maps we must copy the provided value on all value instances */
static void fill_per_cpu_value(struct bpf_map_info *info, void *value)
{
	unsigned int i, n, step;

	if (!map_is_per_cpu(info->type))
		return;

	n = get_possible_cpus();
	step = round_up(info->value_size, 8);
	for (i = 1; i < n; i++)
		memcpy(value + i * step, value, info->value_size);
}

static int parse_elem(char **argv, struct bpf_map_info *info, void *key,
		      void *value, __u32 key_size, __u32 value_size,
		      __u32 *flags, __u32 **value_fd, __u32 open_flags)
{
	if (!*argv) {
		if (!key && !value)
			return 0;
		p_err("did not find %s", key ? "key" : "value");
		return -1;
	}

	if (is_prefix(*argv, "key")) {
		if (!key) {
			if (key_size)
				p_err("duplicate key");
			else
				p_err("unnecessary key");
			return