eqemu-server/common/patches/ss_define.h

/*	EQEMu: Everquest Server Emulator
	
	Copyright (C) 2001-2016 EQEMu Development Team (http://eqemulator.net)

	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; version 2 of the License.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY except by those people which sell it, which
	are required to give you total support for your newly bought product;
	without even the implied warranty of MERCHANTABILITY or FITNESS FOR
	A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#define ENCODE(x) void Strategy::Encode_##x(EQApplicationPacket **p, std::shared_ptr<EQStreamInterface> dest, bool ack_req)
#define DECODE(x) void Strategy::Decode_##x(EQApplicationPacket *__packet)

#define StructDist(in, f1, f2) (uint32(&in->f2)-uint32(&in->f1))
#define CopyBlock(to, field, from, field1, field2) \
	memcpy((void *) &to->field, (const void *) from->field1, StructDist(from, field1, field2));
#define CopyLen(to, field, from, field1, len) \
	memcpy((void *) &to->field, (const void *) from->field1, len);


/*
 *
 * for encoders
 *
 */
//more complex operations and variable length packets
#define FASTQUEUE(packet) dest->FastQueuePacket(&packet, ack_req);
#define TAKE(packet_name) \
	EQApplicationPacket *packet_name = *p; \
	*p = nullptr;

//simple buffer-to-buffer movement for fixed length packets
//the eq packet is mapped into `eq`, the emu packet into `emu`
#define SETUP_DIRECT_ENCODE(emu_struct, eq_struct) \
	SETUP_VAR_ENCODE(emu_struct); \
	ALLOC_VAR_ENCODE(eq_struct, sizeof(eq_struct));

//like a direct encode, but for variable length packets (two stage)
#define SETUP_VAR_ENCODE(emu_struct) \
	EQApplicationPacket *__packet = *p; \
	*p = nullptr; \
	unsigned char *__emu_buffer = __packet->pBuffer; \
	emu_struct *emu = (emu_struct *) __emu_buffer; \
	uint32 __i = 0; \
	__i++; /* to shut up compiler */

#define ALLOC_VAR_ENCODE(eq_struct, len) \
	__packet->pBuffer = new unsigned char[len]; \
	__packet->size = len; \
	memset(__packet->pBuffer, 0, len); \
	eq_struct *eq = (eq_struct *) __packet->pBuffer; \

#define ALLOC_LEN_ENCODE(len) \
	__packet->pBuffer = new unsigned char[len] {}; \
	__packet->size = len; \
	memset(__packet->pBuffer, 0, len); \

//a shorter assignment for direct mode
#undef OUT
#define OUT(x) eq->x = emu->x;
#define OUT_str(x) \
	strncpy(eq->x, emu->x, sizeof(eq->x)); \
        eq->x[sizeof(eq->x)-1] = '\0';
#define OUT_array(x, n) \
	for(__i = 0; __i < n; __i++) \
		eq->x[__i] = emu->x[__i];

//call before any premature returns in an encoder using SETUP_DIRECT_ENCODE
#define FAIL_ENCODE() \
	delete[] __emu_buffer; \
	delete __packet;

//call to finish an encoder using SETUP_DIRECT_ENCODE
#define FINISH_ENCODE() \
	delete[] __emu_buffer; \
	dest->FastQueuePacket(&__packet, ack_req);

//check length of packet before decoding. Call before setup.
#define ENCODE_LENGTH_EXACT(struct_) \
	if((*p)->size != sizeof(struct_)) { \
		LogNetcode("Wrong size on outbound [{}] (" #struct_ "): Got [{}], expected [{}]", opcodes->EmuToName((*p)->GetOpcode()), (*p)->size, sizeof(struct_)); \
		delete *p; \
		*p = nullptr; \
		return; \
	}
#define ENCODE_LENGTH_ATLEAST(struct_) \
	if((*p)->size < sizeof(struct_)) { \
		LogNetcode("Wrong size on outbound [{}] (" #struct_ "): Got [{}], expected at least [{}]", opcodes->EmuToName((*p)->GetOpcode()), (*p)->size, sizeof(struct_)); \
		delete *p; \
		*p = nullptr; \
		return; \
	}

//forward this opcode to another encoder
#define ENCODE_FORWARD(other_op) \
	Encode_##other_op(p, dest, ack_req);

//destroy the packet, it is not sent to this client version
#define EAT_ENCODE(op) \
	ENCODE(op) { \
	delete *p; \
	*p = nullptr; \
	}



/*
 *
 * for decoders:
 *
 */

//simple buffer-to-buffer movement for fixed length packets
//the eq packet is mapped into `eq`, the emu packet into `emu`
#define SETUP_DIRECT_DECODE(emu_struct, eq_struct) \
	unsigned char *__eq_buffer = __packet->pBuffer; \
	__packet->size = sizeof(emu_struct); \
	__packet->pBuffer = new unsigned char[__packet->size] {}; \
	emu_struct *emu = (emu_struct *) __packet->pBuffer; \
	eq_struct *eq = (eq_struct *) __eq_buffer;

#define SETUP_VAR_DECODE(emu_struct, eq_struct, var_field) \
	unsigned char *__eq_buffer = __packet->pBuffer; \
	eq_struct* in = (eq_struct*)__packet->pBuffer; \
	auto size = strlen(in->var_field); \
	__packet->size = sizeof(emu_struct) + size + 1; \
	__packet->pBuffer = new unsigned char[__packet->size] {}; \
	emu_struct *emu = (emu_struct *) __packet->pBuffer; \
	eq_struct *eq = (eq_struct *) __eq_buffer;

#define MEMSET_IN(emu_struct) \
	memset(__packet->pBuffer, 0, sizeof(emu_struct));

//a shorter assignment for direct mode
#undef IN
#define IN(x) emu->x = eq->x;
#define IN_str(x) \
	strncpy(emu->x, eq->x, sizeof(emu->x)); \
        emu->x[sizeof(emu->x)-1] = '\0';
#define IN_array(x, n) \
	for(__i = 0; __i < n; __i++) \
		emu->x[__i] = eq->x[__i];

//call before any premature returns in an encoder using SETUP_DIRECT_DECODE
#define FAIL_DIRECT_DECODE() \
	delete[] __eq_buffer; \
	p->SetOpcode(OP_Unknown);

#define FINISH_VAR_DECODE() \
	delete[] __eq_buffer; 

//call to finish an encoder using SETUP_DIRECT_DECODE
#define FINISH_DIRECT_DECODE() \
	delete[] __eq_buffer;

//check length of packet before decoding. Call before setup.
#define DECODE_LENGTH_EXACT(struct_) \
	if(__packet->size != sizeof(struct_)) { \
		LogNetcode("Wrong size on incoming [{}] (" #struct_ "): Got [{}], expected [{}]", opcodes->EmuToName(__packet->GetOpcode()), __packet->size, sizeof(struct_)); \
		__packet->SetOpcode(OP_Unknown); /* invalidate the packet */ \
		return; \
	}
#define DECODE_LENGTH_ATLEAST(struct_) \
	if(__packet->size < sizeof(struct_)) { \
		LogNetcode("Wrong size on incoming [{}] (" #struct_ "): Got [{}], expected at least [{}]", opcodes->EmuToName(__packet->GetOpcode()), __packet->size, sizeof(struct_)); \
		__packet->SetOpcode(OP_Unknown); /* invalidate the packet */ \
		return; \
	}

//forward this opcode to another decoder
#define DECODE_FORWARD(other_op) \
	Decode_##other_op(__packet);