src/main/c/client/packet.h

/* Minecraft Interprocess Management Client
 * Copyright 2015-2020 Rivoreo
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 */

#ifndef _MCIPM_PACKET_H
#define _MCIPM_PACKET_H

#include <sys/types.h>
#include <stdint.h>

#define MCIPM_GET_VERSION 1
#define MCIPM_GET_ENTITIES 2
#define MCIPM_KILL_ENTITY 3
#define MCIPM_REPLY_ERROR 128
#define MCIPM_REPLY_SUCCESS 129
#define MCIPM_REPLY_VERSION 130
#define MCIPM_REPLY_ENTITIES 131

#define MCIPM_GET_ENTITIES_SELECTOR_ALL 0
#define MCIPM_GET_ENTITIES_SELECTOR_WORLD 1
#define MCIPM_GET_ENTITIES_SELECTOR_ENTITY_ID 2
#define MCIPM_GET_ENTITIES_SELECTOR_ENTITY_TYPE 3

#define MCIPM_KILL_ENTITY_BY_ID 0
#define MCIPM_KILL_ENTITY_BY_UUID 1

#define MCIPM_ERROR_WORLD_NOT_FOUND 1
#define MCIPM_ERROR_PACKET_TYPE_NOT_RECOGNIZED 2
#define MCIPM_ERROR_INTERNAL_ERROR 3
#define MCIPM_ERROR_ENTITY_SELECTOR_NOT_RECOGNIZED 4
#define MCIPM_ERROR_ENTITY_TYPE_NOT_FOUND 5

#define MCIPM_PACKET_MAX_LENGTH (16 * 1024 * 1024)

#define GET_PACKET_EOF -1
#define GET_PACKET_ERROR -2
#define GET_PACKET_SHORT_READ -3
#define GET_PACKET_TOO_SMALL -4
#define GET_PACKET_TOO_LARGE -5
#define GET_PACKET_OUT_OF_MEMORY -6
#define GET_PACKET_INCOMPLETE -7

struct mcipm_packet {
	uint32_t length;
	uint8_t type;
	uint8_t data[0];
};

struct entity {
	uint16_t entry_length;	// Including this variable
	int16_t world_name_offset;
	int16_t entity_type_name_offset;
	int16_t display_name_offset;
	uint32_t entity_id;
	double location_x;
	double location_y;
	double location_z;
	float rotation_yaw;
	float rotation_pitch;
	uint8_t is_living_entity;
	uint8_t is_item;
	uint8_t is_on_ground;
	uint8_t is_dead;
	float width;
	float height;
	int32_t chunk_x;
	int32_t chunk_y;
	int32_t chunk_z;
	uint64_t uuid_most_sig;
	uint64_t uuid_least_sig;
	uint32_t ticks;
	union {
		struct {
			// Living entity properties
			float max_health;
			float health;
			uint32_t idle_time;
			uint32_t attack_target_id;
			// Ageable entity property
			int16_t growing_age;
		}  __attribute__((__packed__)) living;
		struct {
			// Item entity properties
			int16_t health;
			int16_t age;
			int16_t pickup_delay;
			int16_t owner_offset;
			int16_t thrower_offset;
			int16_t item_damage;
			int32_t lifespan;
			uint8_t item_count;
		}  __attribute__((__packed__)) item;
	};
	// Variably-length data
	uint8_t data[0];
} __attribute__((__packed__));

int send_packet_get_version(int);
int send_packet_get_entities(int, const void *, size_t, unsigned int);
int send_packet_kill_entity(int, const char *, long int);
int receive_packet(int, struct mcipm_packet **, int);

#endif