EQ2EMu/EQ2/source/common/packet_functions.cpp

/*  
    EQ2Emulator:  Everquest II Server Emulator
    Copyright (C) 2007  EQ2EMulator Development Team (http://www.eq2emulator.net)

    This file is part of EQ2Emulator.

    EQ2Emulator 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.

    EQ2Emulator 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.

    You should have received a copy of the GNU General Public License
    along with EQ2Emulator.  If not, see <http://www.gnu.org/licenses/>.
*/
#include "../common/debug.h"
#include <iostream>
#include <iomanip>
#include <string.h>
#include <zlib.h>
#include "packet_dump.h"
#include "EQStream.h"
#include "packet_functions.h"

#ifndef WIN32
	#include <netinet/in.h>
#endif

using namespace std;

#define eqemu_alloc_func Z_NULL
#define eqemu_free_func Z_NULL


int DeflatePacket(unsigned char* in_data, int in_length, unsigned char* out_data, int max_out_length) {
#ifdef REUSE_ZLIB
	static bool inited = false;
	static z_stream zstream;
    int zerror;
    
    if(in_data == NULL && out_data == NULL && in_length == 0 && max_out_length == 0) {
    	//special delete state
    	deflateEnd(&zstream);
    	return(0);
    }
    if(!inited) {
		zstream.zalloc    = eqemu_alloc_func;
		zstream.zfree     = eqemu_free_func;
		zstream.opaque    = Z_NULL;
		deflateInit(&zstream, Z_FINISH);
    }
	
	zstream.next_in   = in_data;
	zstream.avail_in  = in_length;
/*	zstream.zalloc    = Z_NULL;
	zstream.zfree     = Z_NULL;
	zstream.opaque    = Z_NULL;
	deflateInit(&zstream, Z_FINISH);*/
	zstream.next_out  = out_data;
	zstream.avail_out = max_out_length;
	zerror = deflate(&zstream, Z_FINISH);
	
	deflateReset(&zstream);
	
	if (zerror == Z_STREAM_END)
	{
//		deflateEnd(&zstream);
		return zstream.total_out;
	}
	else
	{
//		zerror = deflateEnd(&zstream);
		return 0;
	}
#else
	if(in_data == NULL) {
		return(0);
	}
	
	z_stream zstream;
    int zerror;
	
	zstream.next_in   = in_data;
	zstream.avail_in  = in_length;
	zstream.zalloc    = eqemu_alloc_func;
	zstream.zfree     = eqemu_free_func;
	zstream.opaque    = Z_NULL;
	deflateInit(&zstream, Z_FINISH);
	zstream.next_out  = out_data;
	zstream.avail_out = max_out_length;
	zerror = deflate(&zstream, Z_FINISH);
	
	if (zerror == Z_STREAM_END)
	{
		deflateEnd(&zstream);
		return zstream.total_out;
	}
	else
	{
		zerror = deflateEnd(&zstream);
		return 0;
	}
#endif
}

uint32 InflatePacket(uchar* indata, uint32 indatalen, uchar* outdata, uint32 outdatalen, bool iQuiet) {
#ifdef REUSE_ZLIB
	static bool inited = false;
	static z_stream zstream;
    int zerror;
    
    if(indata == NULL && outdata == NULL && indatalen == 0 && outdatalen == 0) {
    	//special delete state
    	inflateEnd(&zstream);
    	return(0);
    }
    if(!inited) {
		zstream.zalloc    = eqemu_alloc_func;
		zstream.zfree     = eqemu_free_func;
		zstream.opaque    = Z_NULL;
		inflateInit2(&zstream, 15);
    }

	zstream.next_in		= indata;
	zstream.avail_in	= indatalen;
	zstream.next_out	= outdata;
	zstream.avail_out	= outdatalen;
	zstream.zalloc    = eqemu_alloc_func;
	zstream.zfree     = eqemu_free_func;
	zstream.opaque		= Z_NULL;
	
	i = inflateInit2( &zstream, 15 ); 
	if (i != Z_OK) { 
		return 0;
	}
	
	zerror = inflate( &zstream, Z_FINISH );
	
	inflateReset(&zstream);
	
	if(zerror == Z_STREAM_END) {
		return zstream.total_out;
	}
	else {
		if (!iQuiet) {
			cout << "Error: InflatePacket: inflate() returned " << zerror << " '";
			if (zstream.msg)
				cout << zstream.msg;
			cout << "'" << endl;
			//DumpPacket(indata-16, indatalen+16);
		}
		
		if (zerror == -4 && zstream.msg == 0)
		{
			return 0;
		}
		
		return 0;
	}
#else
	if(indata == NULL)
		return(0);
	
	z_stream zstream;
	int zerror = 0;
	int i;
	
	zstream.next_in		= indata;
	zstream.avail_in	= indatalen;
	zstream.next_out	= outdata;
	zstream.avail_out	= outdatalen;
	zstream.zalloc    = eqemu_alloc_func;
	zstream.zfree     = eqemu_free_func;
	zstream.opaque		= Z_NULL;
	
	i = inflateInit2( &zstream, 15 ); 
	if (i != Z_OK) { 
		return 0;
	}
	
	zerror = inflate( &zstream, Z_FINISH );
	
	if(zerror == Z_STREAM_END) {
		inflateEnd( &zstream );
		return zstream.total_out;
	}
	else {
		if (!iQuiet) {
			cout << "Error: InflatePacket: inflate() returned " << zerror << " '";
			if (zstream.msg)
				cout << zstream.msg;
			cout << "'" << endl;
			//DumpPacket(indata-16, indatalen+16);
		}
		
		if (zerror == -4 && zstream.msg == 0)
		{
			return 0;
		}
		
		zerror = inflateEnd( &zstream );
		return 0;
	}
#endif
}

int32 roll(int32 in, int8 bits) {
	return ((in << bits) | (in >> (32-bits)));
}

int64 roll(int64 in, int8 bits) {
	return ((in << bits) | (in >> (64-bits)));
}

int32 rorl(int32 in, int8 bits) {
	return ((in >> bits) | (in << (32-bits)));
}

int64 rorl(int64 in, int8 bits) {
	return ((in >> bits) | (in << (64-bits)));
}

int32 CRCLookup(uchar idx) {
	if (idx == 0)
		return 0x00000000;
	
	if (idx == 1)
		return 0x77073096;
	
	if (idx == 2)
		return roll(CRCLookup(1), 1);
	
	if (idx == 4)
		return 0x076DC419;
    
	for (uchar b=7; b>0; b--) {
		uchar bv = 1 << b;
		
		if (!(idx ^ bv)) {
			// bit is only one set
			return ( roll(CRCLookup (4), b - 2) );
		}
		
		if (idx&bv) {
			// bit is set
			return( CRCLookup(bv) ^ CRCLookup(idx&(bv - 1)) );
		}
	}
	
	//Failure
	return false;
}

uint32 GenerateCRC(int32 b, int32 bufsize, uchar *buf) {
	int32 CRC = (b ^ 0xFFFFFFFF);
	int32 bufremain = bufsize;
	uchar* bufptr = buf;
	
	while (bufremain--) {
		CRC = CRCLookup((uchar)(*(bufptr++)^ (CRC&0xFF))) ^ (CRC >> 8);
	}
	
	return (htonl (CRC ^ 0xFFFFFFFF));
}

long int CRCArray[] = {
	0,
1996959894,
3993919788,
2567524794,
124634137,
1886057615,
3915621685,
2657392035,
249268274,
2044508324,
3772115230,
2547177864,
162941995,
2125561021,
3887607047,
2428444049,
498536548,
1789927666,
4089016648,
2227061214,
450548861,
1843258603,
4107580753,
2211677639,
325883990,
1684777152,
4251122042,
2321926636,
335633487,
1661365465,
4195302755,
2366115317,
997073096,
1281953886,
3579855332,
2724688242,
1006888145,
1258607687,
3524101629,
2768942443,
901097722,
1119000684,
3686517206,
2898065728,
853044451,
1172266101,
3705015759,
2882616665,
651767980,
1373503546,
3369554304,
3218104598,
565507253,
1454621731,
3485111705,
3099436303,
671266974,
1594198024,
3322730930,
2970347812,
795835527,
1483230225,
3244367275,
3060149565,
1994146192,
31158534,
2563907772,
4023717930,
1907459465,
112637215,
2680153253,
3904427059,
2013776290,
251722036,
2517215374,
3775830040,
2137656763,
141376813,
2439277719,
3865271297,
1802195444,
476864866,
2238001368,
4066508878,
1812370925,
453092731,
2181625025,
4111451223,
1706088902,
314042704,
2344532202,
4240017532,
1658658271,
366619977,
2362670323,
4224994405,
1303535960,
984961486,
2747007092,
3569037538,
1256170817,
1037604311,
2765210733,
3554079995,
1131014506,
879679996,
2909243462,
3663771856,
1141124467,
855842277,
2852801631,
3708648649,
1342533948,
654459306,
3188396048,
3373015174,
1466479909,
544179635,
3110523913,
3462522015,
1591671054,
702138776,
2966460450,
3352799412,
1504918807,
783551873,
3082640443,
3233442989,
3988292384,
2596254646,
62317068,
1957810842,
3939845945,
2647816111,
81470997,
1943803523,
3814918930,
2489596804,
225274430,
2053790376,
3826175755,
2466906013,
167816743,
2097651377,
4027552580,
2265490386,
503444072,
1762050814,
4150417245,
2154129355,
426522225,
1852507879,
4275313526,
2312317920,
282753626,
1742555852,
4189708143,
2394877945,
397917763,
1622183637,
3604390888,
2714866558,
953729732,
1340076626,
3518719985,
2797360999,
1068828381,
1219638859,
3624741850,
2936675148,
906185462,
1090812512,
3747672003,
2825379669,
829329135,
1181335161,
3412177804,
3160834842,
628085408,
1382605366,
3423369109,
3138078467,
570562233,
1426400815,
3317316542,
2998733608,
733239954,
1555261956,
3268935591,
3050360625,
752459403,
1541320221,
2607071920,
3965973030,
1969922972,
40735498,
2617837225,
3943577151,
1913087877,
83908371,
2512341634,
3803740692,
2075208622,
213261112,
2463272603,
3855990285,
2094854071,
198958881,
2262029012,
4057260610,
1759359992,
534414190,
2176718541,
4139329115,
1873836001,
414664567,
2282248934,
4279200368,
1711684554,
285281116,
2405801727,
4167216745,
1634467795,
376229701,
2685067896,
3608007406,
1308918612,
956543938,
2808555105,
3495958263,
1231636301,
1047427035,
2932959818,
3654703836,
1088359270,
936918000,
2847714899,
3736837829,
1202900863,
817233897,
3183342108,
3401237130,
1404277552,
615818150,
3134207493,
3453421203,
1423857449,
601450431,
3009837614,
3294710456,
1567103746,
711928724,
3020668471,
3272380065,
1510334235,
755167117};

uint32 GenerateCRCRecipe(uint32 initial, void* buf, uint32 len)
{
	uint32 c = 0xFFFFFFFF;
	sint8* u = static_cast<sint8*>(buf);
	for (size_t i = 0; i < len; ++i) 
	{
		c = CRCArray[(c ^ u[i]) & 0xFF] ^ (c >> 8);
	}
	return c;
}