/*
  *  Extract RAR archives
  *
  *  Copyright (C) 2005-2006 trog@uncon.org
  *
  *  This code is based on the work of Alexander L. Roshal (C)
  *
  *  The unRAR sources may be used in any software to handle RAR
  *  archives without limitations free of charge, but cannot be used
  *  to re-create the RAR compression algorithm, which is proprietary.
  *  Distribution of modified unRAR sources in separate form or as a
  *  part of other software is permitted, provided that it is clearly
  *  stated in the documentation and source comments that the code may
  *  not be used to develop a RAR (WinRAR) compatible archiver.
  *
  */
 

 #if HAVE_CONFIG_H
 #include "clamav-config.h"
 #endif
 

 #include <stdio.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "libclamunrar/unrar.h"
 #include "libclamunrar/unrarppm.h"
 #include "libclamunrar/unrarvm.h"
 #include "libclamunrar/unrarfilter.h"
 #include "libclamunrar/unrar20.h"
 #include "libclamunrar/unrar15.h"
 
 #define int64to32(x) ((unsigned int)(x))
 
 #ifdef RAR_HIGH_DEBUG
 #define rar_dbgmsg printf
 #else
 static void rar_dbgmsg(const char* fmt,...){}
 #endif
 
 static void insert_old_dist(unpack_data_t *unpack_data, unsigned int distance)
 {
 	unpack_data->old_dist[3] = unpack_data->old_dist[2];
 	unpack_data->old_dist[2] = unpack_data->old_dist[1];
 	unpack_data->old_dist[1] = unpack_data->old_dist[0];
 	unpack_data->old_dist[0] = distance;
 }
 
 static void insert_last_match(unpack_data_t *unpack_data, unsigned int length, unsigned int distance)
 {
 	unpack_data->last_dist = distance;
 	unpack_data->last_length = length;
 }
 
 static void copy_string(unpack_data_t *unpack_data, unsigned int length, unsigned int distance)
 {
 	unsigned int dest_ptr;
 	
 	dest_ptr = unpack_data->unp_ptr - distance;
 	if (dest_ptr < MAXWINSIZE-260 && unpack_data->unp_ptr < MAXWINSIZE - 260) {
 		unpack_data->window[unpack_data->unp_ptr++] = unpack_data->window[dest_ptr++];
 		while (--length > 0) {
 			unpack_data->window[unpack_data->unp_ptr++] = unpack_data->window[dest_ptr++];
 		}
 	} else {
 		while (length--) {
 			unpack_data->window[unpack_data->unp_ptr] =
 						unpack_data->window[dest_ptr++ & MAXWINMASK];
 			unpack_data->unp_ptr = (unpack_data->unp_ptr + 1) & MAXWINMASK;
 		}
 	}
 }
 
 void rar_addbits(unpack_data_t *unpack_data, int bits)
 {
 
 	/*rar_dbgmsg("rar_addbits: in_addr=%d in_bit=%d\n", unpack_data->in_addr, unpack_data->in_bit);*/
 	bits += unpack_data->in_bit;
 	unpack_data->in_addr += bits >> 3;
 	unpack_data->in_bit = bits & 7;
 }
 
 unsigned int rar_getbits(unpack_data_t *unpack_data)
 {
 	unsigned int bit_field;
 
 	/*rar_dbgmsg("rar_getbits: in_addr=%d in_bit=%d\n", unpack_data->in_addr, unpack_data->in_bit);*/
 	bit_field = (unsigned int) unpack_data->in_buf[unpack_data->in_addr] << 16;
 	bit_field |= (unsigned int) unpack_data->in_buf[unpack_data->in_addr+1] << 8;
 	bit_field |= (unsigned int) unpack_data->in_buf[unpack_data->in_addr+2];
 	bit_field >>= (8-unpack_data->in_bit);
 	/*rar_dbgmsg("rar_getbits return(%d)\n", BitField & 0xffff);*/
 	return(bit_field & 0xffff);
 }
 
 int rar_unp_read_buf(int fd, unpack_data_t *unpack_data)
 {
 	int data_size, retval;
 	unsigned int read_size;
 
 	data_size = unpack_data->read_top - unpack_data->in_addr;
 	if (data_size < 0) {
 		return FALSE;
 	}
 	
 	/* Is buffer read pos more than half way? */
 	if (unpack_data->in_addr > MAX_BUF_SIZE/2) {
 		if (data_size > 0) {
 			memmove(unpack_data->in_buf, unpack_data->in_buf+unpack_data->in_addr,
 					data_size);
 		}
 		unpack_data->in_addr = 0;
 		unpack_data->read_top = data_size;
 	} else {
 		data_size = unpack_data->read_top;
 	}
 	/* RAR2 depends on us only reading upto the end of the current compressed file */
 	if (unpack_data->pack_size < ((MAX_BUF_SIZE-data_size)&~0xf)) {
 		read_size = unpack_data->pack_size;
 	} else {
 		read_size = (MAX_BUF_SIZE-data_size)&~0xf;
 	}
 	retval = read(fd, unpack_data->in_buf+data_size, read_size);	
 	if (retval > 0) {
 		unpack_data->read_top += retval;
 		unpack_data->pack_size -= retval;
 	}
 	unpack_data->read_border = unpack_data->read_top - 30;
 	if(unpack_data->read_border < unpack_data->in_addr) {
 		const ssize_t fill = ((unpack_data->read_top + 30) < MAX_BUF_SIZE) ? 30 : (MAX_BUF_SIZE - unpack_data->read_top);
 		if(fill)
 			memset(unpack_data->in_buf + unpack_data->read_top, 0, fill);
 	}
 	return (retval!=-1);
 }
 
 unsigned int rar_get_char(int fd, unpack_data_t *unpack_data)
 {
 	if (unpack_data->in_addr > MAX_BUF_SIZE-30) {
 		if (!rar_unp_read_buf(fd, unpack_data)) {
 			rar_dbgmsg("rar_get_char: rar_unp_read_buf FAILED\n"); /* FIXME: cli_errmsg */
 			return -1;
 		}
 	}
 	rar_dbgmsg("rar_get_char = %u\n", unpack_data->in_buf[unpack_data->in_addr]);
 	return(unpack_data->in_buf[unpack_data->in_addr++]);
 }
 
 static void unp_write_data(unpack_data_t *unpack_data, uint8_t *data, int size)
 {

 	int ret;

 	rar_dbgmsg("in unp_write_data length=%d\n", size);

 
 	unpack_data->true_size += size;
 	unpack_data->unp_crc = rar_crc(unpack_data->unp_crc, data, size);
 	if(unpack_data->max_size) {
 	    if(unpack_data->written_size >= unpack_data->max_size)
 		return;
 
 	    if(unpack_data->written_size + size > unpack_data->max_size)
 		size = unpack_data->max_size - unpack_data->written_size;
 	}

 	if((ret = write(unpack_data->ofd, data, size)) > 0)
 	    unpack_data->written_size += ret;

 }
 
 static void unp_write_area(unpack_data_t *unpack_data, unsigned int start_ptr, unsigned int end_ptr)
 {
 	if (end_ptr < start_ptr) {
 		unp_write_data(unpack_data, &unpack_data->window[start_ptr], -start_ptr & MAXWINMASK);
 		unp_write_data(unpack_data, unpack_data->window, end_ptr);
 	} else {
 		unp_write_data(unpack_data, &unpack_data->window[start_ptr], end_ptr-start_ptr);
 	}
 }
 
 void rar_unp_write_buf_old(unpack_data_t *unpack_data)
 {
 	rar_dbgmsg("in rar_unp_write_buf_old\n");
 	if (unpack_data->unp_ptr < unpack_data->wr_ptr) {
 		unp_write_data(unpack_data, &unpack_data->window[unpack_data->wr_ptr],
 				-unpack_data->wr_ptr & MAXWINMASK);
 		unp_write_data(unpack_data, unpack_data->window, unpack_data->unp_ptr);
 	} else {
 		unp_write_data(unpack_data, &unpack_data->window[unpack_data->wr_ptr],
 				unpack_data->unp_ptr - unpack_data->wr_ptr);
 	}
 	unpack_data->wr_ptr = unpack_data->unp_ptr;
 }
 
 static void execute_code(unpack_data_t *unpack_data, struct rarvm_prepared_program *prg)
 {
 	rar_dbgmsg("in execute_code\n");
 	rar_dbgmsg("global_size: %ld\n", prg->global_size);
 	if (prg->global_size > 0) {
 		prg->init_r[6] = int64to32(unpack_data->written_size);
 		rarvm_set_value(FALSE, (unsigned int *)&prg->global_data[0x24],
 				int64to32(unpack_data->written_size));
 		rarvm_set_value(FALSE, (unsigned int *)&prg->global_data[0x28],
 				int64to32(unpack_data->written_size>>32));
 		rarvm_execute(&unpack_data->rarvm_data, prg);
 	}
 }
 
 		
 static void unp_write_buf(unpack_data_t *unpack_data)
 {
 	unsigned int written_border, part_length, filtered_size;
 	unsigned int write_size, block_start, block_length, block_end;
 	struct UnpackFilter *flt, *next_filter;
 	struct rarvm_prepared_program *prg, *next_prg;
 	uint8_t *filtered_data;
 	int i, j;
 	
 	rar_dbgmsg("in unp_write_buf\n");
 	written_border = unpack_data->wr_ptr;
 	write_size = (unpack_data->unp_ptr - written_border) & MAXWINMASK;
 	for (i=0 ; i < unpack_data->PrgStack.num_items ; i++) {
 		flt = unpack_data->PrgStack.array[i];
 		if (flt == NULL) {
 			continue;
 		}
 		if (flt->next_window) {
 			flt->next_window = FALSE;
 			continue;
 		}
 		block_start = flt->block_start;
 		block_length = flt->block_length;
 		if (((block_start-written_border)&MAXWINMASK) < write_size) {
 			if (written_border != block_start) {
 				unp_write_area(unpack_data, written_border, block_start);
 				written_border = block_start;
 				write_size = (unpack_data->unp_ptr - written_border) & MAXWINMASK;
 			}
 			if (block_length <= write_size) {
 				block_end = (block_start + block_length) & MAXWINMASK;
 				if (block_start < block_end || block_end==0) {
 					rarvm_set_memory(&unpack_data->rarvm_data, 0,
 							unpack_data->window+block_start, block_length);
 				} else {
 					part_length = MAXWINMASK - block_start;
 					rarvm_set_memory(&unpack_data->rarvm_data, 0,
 							unpack_data->window+block_start, part_length);
 					rarvm_set_memory(&unpack_data->rarvm_data, part_length,
 							unpack_data->window, block_end);
 				}
 				prg = &flt->prg;
 				execute_code(unpack_data, prg);
 				
 				filtered_data = prg->filtered_data;
 				filtered_size = prg->filtered_data_size;
 				
 				rar_filter_delete(unpack_data->PrgStack.array[i]);
 				unpack_data->PrgStack.array[i] = NULL;
 				while (i+1 < unpack_data->PrgStack.num_items) {
 					next_filter = unpack_data->PrgStack.array[i+1];
 					if (next_filter==NULL ||
 							next_filter->block_start!=block_start ||
 							next_filter->block_length!=filtered_size ||
 							next_filter->next_window) {
 						break;
 					}
 					rarvm_set_memory(&unpack_data->rarvm_data, 0,
 							filtered_data, filtered_size);
 					next_prg = &unpack_data->PrgStack.array[i+1]->prg;
 					execute_code(unpack_data, next_prg);
 					filtered_data = next_prg->filtered_data;
 					filtered_size = next_prg->filtered_data_size;
 					i++;
 					rar_filter_delete(unpack_data->PrgStack.array[i]);
 					unpack_data->PrgStack.array[i] = NULL;
 				}
 				unp_write_data(unpack_data, filtered_data, filtered_size);
 				written_border = block_end;
 				write_size = (unpack_data->unp_ptr - written_border) & MAXWINMASK;
 			} else {
 				for (j=i ; j < unpack_data->PrgStack.num_items ; j++) {
 					flt = unpack_data->PrgStack.array[j];
 					if (flt != NULL && flt->next_window) {
 						flt->next_window = FALSE;
 					}
 				}
 				unpack_data->wr_ptr = written_border;
 				return;
 				
 			}
 		}
 	}
 	unp_write_area(unpack_data, written_border, unpack_data->unp_ptr);
 	unpack_data->wr_ptr = unpack_data->unp_ptr;
 }
 
 void rar_make_decode_tables(unsigned char *len_tab, struct Decode *decode, int size)
 {
 	int len_count[16], tmp_pos[16], i;
 	long m,n;
 	
 	memset(len_count, 0, sizeof(len_count));
 	memset(decode->DecodeNum,0,size*sizeof(*decode->DecodeNum));
 	for (i=0 ; i < size ; i++) {
 		len_count[len_tab[i] & 0x0f]++;
 	}
 	
 	len_count[0]=0;
 	for (tmp_pos[0]=decode->DecodePos[0]=decode->DecodeLen[0]=0,n=0,i=1;i<16;i++) {
 		n=2*(n+len_count[i]);
 		m=n<<(15-i);
 		if (m>0xFFFF) {
 			m=0xFFFF;
 		}
 		decode->DecodeLen[i]=(unsigned int)m;
 		tmp_pos[i]=decode->DecodePos[i]=decode->DecodePos[i-1]+len_count[i-1];
 	}
 	
 	for (i=0;i<size;i++) {
 		if (len_tab[i]!=0) {
 			decode->DecodeNum[tmp_pos[len_tab[i] & 0x0f]++]=i;
 		}
 	}
 	decode->MaxNum=size;
 }
 
 int rar_decode_number(unpack_data_t *unpack_data, struct Decode *decode)
 {
 	unsigned int bits, bit_field, n;
 	
 	bit_field = rar_getbits(unpack_data) & 0xfffe;
 	rar_dbgmsg("rar_decode_number BitField=%u\n", bit_field);
 	if (bit_field < decode->DecodeLen[8])
 		if (bit_field < decode->DecodeLen[4])
 			if (bit_field < decode->DecodeLen[2])
 				if (bit_field < decode->DecodeLen[1])
 					bits=1;
 				else
 					bits=2;
 			else
 				if (bit_field < decode->DecodeLen[3])
 					bits=3;
 				else
 					bits=4;
 		else
 			if (bit_field < decode->DecodeLen[6])
 				if (bit_field < decode->DecodeLen[5])
 					bits=5;
 				else
 					bits=6;
 			else
 				if (bit_field < decode->DecodeLen[7])
 					bits=7;
 				else
 					bits=8;
 	else
 		if (bit_field < decode->DecodeLen[12])
 			if (bit_field < decode->DecodeLen[10])
 				if (bit_field < decode->DecodeLen[9])
 					bits=9;
 				else
 					bits=10;
 			else
 				if (bit_field < decode->DecodeLen[11])
 					bits=11;
 				else
 					bits=12;
 		else
 			if (bit_field < decode->DecodeLen[14])
 				if (bit_field < decode->DecodeLen[13])
 					bits=13;
 				else
 					bits=14;
 			else
 				bits=15;
 
 	rar_dbgmsg("rar_decode_number: bits=%d\n", bits);
 
 	rar_addbits(unpack_data, bits);
 	n=decode->DecodePos[bits]+((bit_field-decode->DecodeLen[bits-1])>>(16-bits));
 	if (n >= decode->MaxNum) {
 		n=0;
 	}
 	/*rar_dbgmsg("rar_decode_number return(%d)\n", decode->DecodeNum[n]);*/
 
 	return(decode->DecodeNum[n]);
 }
 
 static int read_tables(int fd, unpack_data_t *unpack_data)
 {
 	uint8_t bit_length[BC];
 	unsigned char table[HUFF_TABLE_SIZE];
 	unsigned int bit_field;
 	int i, length, zero_count, number, n;
 	const int table_size=HUFF_TABLE_SIZE;
 	
 	rar_dbgmsg("in read_tables Offset=%ld in_addr=%d read_top=%d\n", lseek(fd, 0, SEEK_CUR),
 				unpack_data->in_addr, unpack_data->read_top);
 	if (unpack_data->in_addr > unpack_data->read_top-25) {
 		if (!rar_unp_read_buf(fd, unpack_data)) {
 			rar_dbgmsg("ERROR: read_tables rar_unp_read_buf failed\n");
 			return FALSE;
 		}
 	}
 	rar_addbits(unpack_data, (8-unpack_data->in_bit) & 7);
 	bit_field = rar_getbits(unpack_data);
 	rar_dbgmsg("BitField = 0x%x\n", bit_field);
 	if (bit_field & 0x8000) {
 		unpack_data->unp_block_type = BLOCK_PPM;
 		rar_dbgmsg("Calling ppm_decode_init\n");
 		if(!ppm_decode_init(&unpack_data->ppm_data, fd, unpack_data, &unpack_data->ppm_esc_char)) {
 		    rar_dbgmsg("unrar: read_tables: ppm_decode_init failed\n");
 		    return FALSE;
 		}
 		return(TRUE);
 	}
 	unpack_data->unp_block_type = BLOCK_LZ;
 	unpack_data->prev_low_dist = 0;
 	unpack_data->low_dist_rep_count = 0;
 
 	if (!(bit_field & 0x4000)) {
 		memset(unpack_data->unp_old_table, 0, sizeof(unpack_data->unp_old_table));
 	}
 	rar_addbits(unpack_data, 2);
 	
 	for (i=0 ; i < BC ; i++) {
 		length = (uint8_t)(rar_getbits(unpack_data) >> 12);
 		rar_addbits(unpack_data, 4);
 		if (length == 15) {
 			zero_count = (uint8_t)(rar_getbits(unpack_data) >> 12);
 			rar_addbits(unpack_data, 4);
 			if (zero_count == 0) {
 				bit_length[i] = 15;
 			} else {
 				zero_count += 2;
 				while (zero_count-- > 0 &&
 						i<sizeof(bit_length)/sizeof(bit_length[0])) {
 					bit_length[i++]=0;
 				}
 				i--;
 			}
 		} else {
 			bit_length[i] = length;
 		}
 	}
 	rar_make_decode_tables(bit_length,(struct Decode *)&unpack_data->BD,BC);
 	
 	for (i=0;i<table_size;) {
 		if (unpack_data->in_addr > unpack_data->read_top-5) {
 			if (!rar_unp_read_buf(fd, unpack_data)) {
 				rar_dbgmsg("ERROR: read_tables rar_unp_read_buf failed 2\n");
 				return FALSE;
 			}
 		}
 		number = rar_decode_number(unpack_data, (struct Decode *)&unpack_data->BD);
 		if (number < 16) {
 			table[i] = (number+unpack_data->unp_old_table[i]) & 0xf;
 			i++;
 		} else if (number < 18) {
 			if (number == 16) {
 				n = (rar_getbits(unpack_data) >> 13) + 3;
 				rar_addbits(unpack_data, 3);
 			} else {
 				n = (rar_getbits(unpack_data) >> 9) + 11;
 				rar_addbits(unpack_data, 7);
 			}
 			while (n-- > 0 && i < table_size) {
 				table[i] = table[i-1];
 				i++;
 			}
 		} else {
 			if (number == 18) {
 				n = (rar_getbits(unpack_data) >> 13) + 3;
 				rar_addbits(unpack_data, 3);
 			} else {
 				n = (rar_getbits(unpack_data) >> 9) + 11;
 				rar_addbits(unpack_data, 7);
 			}
 			while (n-- > 0 && i < table_size) {
 				table[i++] = 0;
 			}
 		}
 	}
 	unpack_data->tables_read = TRUE;
 	if (unpack_data->in_addr > unpack_data->read_top) {
 		rar_dbgmsg("ERROR: read_tables check failed\n");
 		return FALSE;
 	}
 	rar_make_decode_tables(&table[0], (struct Decode *)&unpack_data->LD,NC);
 	rar_make_decode_tables(&table[NC], (struct Decode *)&unpack_data->DD,DC);
 	rar_make_decode_tables(&table[NC+DC], (struct Decode *)&unpack_data->LDD,LDC);
 	rar_make_decode_tables(&table[NC+DC+LDC], (struct Decode *)&unpack_data->RD,RC);
 	memcpy(unpack_data->unp_old_table,table,sizeof(unpack_data->unp_old_table));
 	
 
 	/*dump_tables(unpack_data);*/
 	rar_dbgmsg("ReadTables finished\n");
   	return TRUE;
 }
 
 static int read_end_of_block(int fd, unpack_data_t *unpack_data)
 {
 	unsigned int bit_field;
 	int new_table, new_file=FALSE;
 	
 	bit_field = rar_getbits(unpack_data);
 	if (bit_field & 0x8000) {
 		new_table = TRUE;
 		rar_addbits(unpack_data, 1);
 	} else {
 		new_file = TRUE;
 		new_table = (bit_field & 0x4000);
 		rar_addbits(unpack_data, 2);
 	}
 	unpack_data->tables_read = !new_table;
 	rar_dbgmsg("NewFile=%d NewTable=%d TablesRead=%d\n", new_file,
 			new_table, unpack_data->tables_read);
 	return !(new_file || (new_table && !read_tables(fd, unpack_data)));
 }
 
 void rar_init_filters(unpack_data_t *unpack_data)
 {	
 	if (unpack_data->old_filter_lengths) {
 		free(unpack_data->old_filter_lengths);
 		unpack_data->old_filter_lengths = NULL;
 	}
 	unpack_data->old_filter_lengths_size = 0;
 	unpack_data->last_filter = 0;
 	
 	rar_filter_array_reset(&unpack_data->Filters);
 	rar_filter_array_reset(&unpack_data->PrgStack);
 }
 
 static int add_vm_code(unpack_data_t *unpack_data, unsigned int first_byte,
 			unsigned char *vmcode, int code_size)
 {
 	rarvm_input_t rarvm_input;
 	unsigned int filter_pos, new_filter, block_start, init_mask, cur_size;
 	struct UnpackFilter *filter, *stack_filter;
 	int i, empty_count, stack_pos, vm_codesize, static_size, data_size;
 	unsigned char *vm_code, *global_data;
 	
 	rar_dbgmsg("in add_vm_code first_byte=0x%x code_size=%d\n", first_byte, code_size);
 	rarvm_input.in_buf = vmcode;
 	rarvm_input.buf_size = code_size;
 	rarvm_input.in_addr = 0;
 	rarvm_input.in_bit = 0;
 
 	if (first_byte & 0x80) {
 		filter_pos = rarvm_read_data(&rarvm_input);
 		if (filter_pos == 0) {
 			rar_init_filters(unpack_data);
 		} else {
 			filter_pos--;
 		}
 	} else {
 		filter_pos = unpack_data->last_filter;
 	}
 	rar_dbgmsg("filter_pos = %u\n", filter_pos);
 	if (filter_pos > unpack_data->Filters.num_items ||
 			filter_pos > unpack_data->old_filter_lengths_size) {
 		rar_dbgmsg("filter_pos check failed\n");
 		return FALSE;
 	}
 	unpack_data->last_filter = filter_pos;
 	new_filter = (filter_pos == unpack_data->Filters.num_items);
 	rar_dbgmsg("Filters.num_items=%d\n", unpack_data->Filters.num_items);
 	rar_dbgmsg("new_filter=%d\n", new_filter);
 	if (new_filter) {
 		if (!rar_filter_array_add(&unpack_data->Filters, 1)) {
 			rar_dbgmsg("rar_filter_array_add failed\n");
 			return FALSE;
 		}
 		unpack_data->Filters.array[unpack_data->Filters.num_items-1] =
 					filter = rar_filter_new();
 		if (!unpack_data->Filters.array[unpack_data->Filters.num_items-1]) {
 			rar_dbgmsg("rar_filter_new failed\n");
 			return FALSE;
 		}	
 		unpack_data->old_filter_lengths_size++;
 		unpack_data->old_filter_lengths = (int *) rar_realloc2(unpack_data->old_filter_lengths,
 				sizeof(int) * unpack_data->old_filter_lengths_size);
 		if(!unpack_data->old_filter_lengths) {
 		    rar_dbgmsg("unrar: add_vm_code: rar_realloc2 failed for unpack_data->old_filter_lengths\n");
 		    return FALSE;
 		}
 		unpack_data->old_filter_lengths[unpack_data->old_filter_lengths_size-1] = 0;
 		filter->exec_count = 0;
 	} else {
 		filter = unpack_data->Filters.array[filter_pos];
 		filter->exec_count++;
 	}
 	
 	stack_filter = rar_filter_new();
 
 	empty_count = 0;
 	for (i=0 ; i < unpack_data->PrgStack.num_items; i++) {
 		unpack_data->PrgStack.array[i-empty_count] = unpack_data->PrgStack.array[i];
 		if (unpack_data->PrgStack.array[i] == NULL) {
 			empty_count++;
 		}
 		if (empty_count > 0) {
 			unpack_data->PrgStack.array[i] = NULL;
 		}
 	}
 	
 	if (empty_count == 0) {
 		rar_filter_array_add(&unpack_data->PrgStack, 1);
 		empty_count = 1;
 	}
 	stack_pos = unpack_data->PrgStack.num_items - empty_count;
 	unpack_data->PrgStack.array[stack_pos] = stack_filter;
 	stack_filter->exec_count = filter->exec_count;
 	
 	block_start = rarvm_read_data(&rarvm_input);
 	rar_dbgmsg("block_start=%u\n", block_start);
 	if (first_byte & 0x40) {
 		block_start += 258;
 	}
 	stack_filter->block_start = (block_start + unpack_data->unp_ptr) & MAXWINMASK;
 	if (first_byte & 0x20) {
 		stack_filter->block_length = rarvm_read_data(&rarvm_input);
 	} else {
 		stack_filter->block_length = filter_pos < unpack_data->old_filter_lengths_size ?
 				unpack_data->old_filter_lengths[filter_pos] : 0;
 	}
 	rar_dbgmsg("block_length=%u\n", stack_filter->block_length);
 	stack_filter->next_window = unpack_data->wr_ptr != unpack_data->unp_ptr &&
 		((unpack_data->wr_ptr - unpack_data->unp_ptr) & MAXWINMASK) <= block_start;
 		
 	unpack_data->old_filter_lengths[filter_pos] = stack_filter->block_length;
 	
 	memset(stack_filter->prg.init_r, 0, sizeof(stack_filter->prg.init_r));
 	stack_filter->prg.init_r[3] = VM_GLOBALMEMADDR;
 	stack_filter->prg.init_r[4] = stack_filter->block_length;
 	stack_filter->prg.init_r[5] = stack_filter->exec_count;
 	if (first_byte & 0x10) {
 		init_mask = rarvm_getbits(&rarvm_input) >> 9;
 		rarvm_addbits(&rarvm_input, 7);
 		for (i=0 ; i<7 ; i++) {
 			if (init_mask & (1<<i)) {
 				stack_filter->prg.init_r[i] =
 					rarvm_read_data(&rarvm_input);
 				rar_dbgmsg("prg.init_r[%d] = %u\n", i, stack_filter->prg.init_r[i]);
 			}
 		}
 	}
 	if (new_filter) {
 		vm_codesize = rarvm_read_data(&rarvm_input);

 		if (vm_codesize >= 0x1000 || vm_codesize == 0 || (vm_codesize > rarvm_input.buf_size) || vm_codesize < 0) {

 			rar_dbgmsg("ERROR: vm_codesize=0x%x buf_size=0x%x\n", vm_codesize, rarvm_input.buf_size);
 			return FALSE;
 		}
 		vm_code = (unsigned char *) rar_malloc(vm_codesize);
 		if(!vm_code) {
 		    rar_dbgmsg("unrar: add_vm_code: rar_malloc failed for vm_code\n");
 		    return FALSE;
 		}
 		for (i=0 ; i < vm_codesize ; i++) {
 			vm_code[i] = rarvm_getbits(&rarvm_input) >> 8;
 			rarvm_addbits(&rarvm_input, 8);
 		}
 		if(!rarvm_prepare(&unpack_data->rarvm_data, &rarvm_input, &vm_code[0], vm_codesize, &filter->prg)) {
 		    rar_dbgmsg("unrar: add_vm_code: rarvm_prepare failed\n");
 		    free(vm_code);
 		    return FALSE;
 		}
 		free(vm_code);
 	}
 	stack_filter->prg.alt_cmd = &filter->prg.cmd.array[0];
 	stack_filter->prg.cmd_count = filter->prg.cmd_count;
 	
 	static_size = filter->prg.static_size;
 	if (static_size > 0 && static_size < VM_GLOBALMEMSIZE) {
 		stack_filter->prg.static_data = rar_malloc(static_size);
 		if(!stack_filter->prg.static_data) {
 		    rar_dbgmsg("unrar: add_vm_code: rar_malloc failed for stack_filter->prg.static_data\n");
 		    return FALSE;
 		}
 		memcpy(stack_filter->prg.static_data, filter->prg.static_data, static_size);
 	}
 	
 	if (stack_filter->prg.global_size < VM_FIXEDGLOBALSIZE) {
 		free(stack_filter->prg.global_data);
 		stack_filter->prg.global_data = rar_malloc(VM_FIXEDGLOBALSIZE);
 		if(!stack_filter->prg.global_data) {
 		    rar_dbgmsg("unrar: add_vm_code: rar_malloc failed for stack_filter->prg.global_data\n");
 		    return FALSE;
 		}
 		memset(stack_filter->prg.global_data, 0, VM_FIXEDGLOBALSIZE);
 		stack_filter->prg.global_size = VM_FIXEDGLOBALSIZE;
 	}
 	global_data = &stack_filter->prg.global_data[0];
 	for (i=0 ; i<7 ; i++) {
 		rar_dbgmsg("init_r[%d]=%u\n", i, stack_filter->prg.init_r[i]);
 		rarvm_set_value(FALSE, (unsigned int *)&global_data[i*4],
 				stack_filter->prg.init_r[i]);
 	}
 	rarvm_set_value(FALSE, (unsigned int *)&global_data[0x1c], stack_filter->block_length);
 	rarvm_set_value(FALSE, (unsigned int *)&global_data[0x20], 0);
 	rarvm_set_value(FALSE, (unsigned int *)&global_data[0x2c], stack_filter->exec_count);
 	memset(&global_data[0x30], 0, 16);
 	for (i=0 ; i< 30 ; i++) {
 		rar_dbgmsg("global_data[%d] = %d\n", i, global_data[i]);
 	}
 	if (first_byte & 8) {
 		data_size = rarvm_read_data(&rarvm_input);
 		if (data_size >= 0x10000) {
 			return FALSE;
 		}
 		cur_size = stack_filter->prg.global_size;
 		if (cur_size < data_size+VM_FIXEDGLOBALSIZE) {
 			stack_filter->prg.global_size += data_size+VM_FIXEDGLOBALSIZE-cur_size;
 			stack_filter->prg.global_data = rar_realloc2(stack_filter->prg.global_data,
 				stack_filter->prg.global_size);
 			if(!stack_filter->prg.global_data) {
 			    rar_dbgmsg("unrar: add_vm_code: rar_realloc2 failed for stack_filter->prg.global_data\n");
 			    return FALSE;
 			}
 		}
 		global_data = &stack_filter->prg.global_data[VM_FIXEDGLOBALSIZE];
 		for (i=0 ; i< data_size ; i++) {
 			if ((rarvm_input.in_addr+2) > rarvm_input.buf_size) {
 				rar_dbgmsg("Buffer truncated\n");
 				return FALSE;
 			}
 			global_data[i] = rarvm_getbits(&rarvm_input) >> 8;
 			rar_dbgmsg("global_data[%d] = %d\n", i, global_data[i]);
 			rarvm_addbits(&rarvm_input, 8);
 		}
 	}
 	return TRUE;
 }
 
 static int read_vm_code(unpack_data_t *unpack_data, int fd)
 {
 	unsigned int first_byte;
 	int length, i, retval;
 	unsigned char *vmcode;
 	
 	first_byte = rar_getbits(unpack_data)>>8;
 	rar_addbits(unpack_data, 8);
 	length = (first_byte & 7) + 1;
 	if (length == 7) {
 		length = (rar_getbits(unpack_data) >> 8) + 7;
 		rar_addbits(unpack_data, 8);
 	} else if (length == 8) {
 		length = rar_getbits(unpack_data);
 		rar_addbits(unpack_data, 16);
 	}
 	vmcode = (unsigned char *) rar_malloc(length + 2);
 	rar_dbgmsg("VM code length: %d\n", length);
 	if (!vmcode) {
 		return FALSE;
 	}
 	for (i=0 ; i < length ; i++) {
 		if (unpack_data->in_addr >= unpack_data->read_top-1 &&
 				!rar_unp_read_buf(fd, unpack_data) && i<length-1) {

 			free(vmcode);

 			return FALSE;
 		}
 		vmcode[i] = rar_getbits(unpack_data) >> 8;
 		rar_addbits(unpack_data, 8);
 	}
 	retval = add_vm_code(unpack_data, first_byte, vmcode, length);
 	free(vmcode);
 	return retval;
 }
 
 static int read_vm_code_PPM(unpack_data_t *unpack_data, int fd)
 {
 	unsigned int first_byte;
 	int length, i, ch, retval, b1, b2;
 	unsigned char *vmcode;
 	
 	first_byte = ppm_decode_char(&unpack_data->ppm_data, fd, unpack_data);
 	if ((int)first_byte == -1) {
 		return FALSE;
 	}
 	length = (first_byte & 7) + 1;
 	if (length == 7) {
 		b1 = ppm_decode_char(&unpack_data->ppm_data, fd, unpack_data);
 		if (b1 == -1) {
 			return FALSE;
 		}
 		length = b1 + 7;
 	} else if (length == 8) {
 		b1 = ppm_decode_char(&unpack_data->ppm_data, fd, unpack_data);
 		if (b1 == -1) {
 			return FALSE;
 		}
 		b2 = ppm_decode_char(&unpack_data->ppm_data, fd, unpack_data);
 		if (b2 == -1) {
 			return FALSE;
 		}
 		length = b1*256 + b2;
 	}
 	vmcode = (unsigned char *) rar_malloc(length + 2);
 	rar_dbgmsg("VM PPM code length: %d\n", length);
 	if (!vmcode) {
 		return FALSE;
 	}
 	for (i=0 ; i < length ; i++) {
 		ch = ppm_decode_char(&unpack_data->ppm_data, fd, unpack_data);
 		if (ch == -1) {
 			free(vmcode);
 			return FALSE;
 		}
 		vmcode[i] = ch;
 	}
 	retval = add_vm_code(unpack_data, first_byte, vmcode, length);
 	free(vmcode);
 	return retval;
 }
 
 void rar_unpack_init_data(int solid, unpack_data_t *unpack_data)
 {
 	if (!solid) {
 		unpack_data->tables_read = FALSE;
 		memset(unpack_data->old_dist, 0, sizeof(unpack_data->old_dist));
 		unpack_data->old_dist_ptr= 0;
 		memset(unpack_data->unp_old_table, 0, sizeof(unpack_data->unp_old_table));

 		memset(&unpack_data->LD, 0, sizeof(unpack_data->LD));
 		memset(&unpack_data->DD, 0, sizeof(unpack_data->DD));
 		memset(&unpack_data->LDD, 0, sizeof(unpack_data->LDD));
 		memset(&unpack_data->RD, 0, sizeof(unpack_data->RD));
 		memset(&unpack_data->BD, 0, sizeof(unpack_data->BD));

 		unpack_data->last_dist= 0;
 		unpack_data->last_length=0;
 		unpack_data->ppm_esc_char = 2;
 		unpack_data->unp_ptr = 0;
 		unpack_data->wr_ptr = 0;

 		unpack_data->unp_block_type = BLOCK_LZ;

 		rar_init_filters(unpack_data);
 	}
 	unpack_data->in_bit = 0;
 	unpack_data->in_addr = 0;
 	unpack_data->read_top = 0;

 	unpack_data->read_border = 0;

 	unpack_data->written_size = 0;

 	unpack_data->true_size = 0;

 	rarvm_init(&unpack_data->rarvm_data);
 	unpack_data->unp_crc = 0xffffffff;
 	
 	unpack_init_data20(solid, unpack_data);
 
 }
 
 static int rar_unpack29(int fd, int solid, unpack_data_t *unpack_data)
 {
 	unsigned char ldecode[]={0,1,2,3,4,5,6,7,8,10,12,14,16,20,24,28,
 			32,40,48,56,64,80,96,112,128,160,192,224};
 	unsigned char lbits[]=  {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5};
 	int ddecode[DC]={0,1,2,3,4,6,8,12,16,24,32,48,64,96,128,192,256,384,512,768,1024,
 		1536,2048,3072,4096,6144,8192,12288,16384,24576,32768,49152,65536,
 		98304,131072,196608,262144,327680,393216,458752,524288,589824,655360,
 		720896,786432,851968,917504,983040,1048576,1310720,1572864,
 		1835008,2097152,2359296,2621440,2883584,3145728,3407872,3670016,3932160};
 	uint8_t dbits[DC]= {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,
 		11,11,12,12,13,13,14,14,15,15,16,16,16,16,16,16,16,16,16,
 		16,16,16,16,16,18,18,18,18,18,18,18,18,18,18,18,18};
 	unsigned char sddecode[]={0,4,8,16,32,64,128,192};
 	unsigned char sdbits[]=  {2,2,3, 4, 5, 6,  6,  6};
 	unsigned int bits, distance;
 	int retval=TRUE, i, number, length, dist_number, low_dist, ch, next_ch;
 	int length_number, failed;
 
 	rar_dbgmsg("Offset: %ld\n", lseek(fd, 0, SEEK_CUR));
 	if (!solid) {
 		rar_dbgmsg("Not solid\n");
 	}
 	rar_unpack_init_data(solid, unpack_data);
 	if (!rar_unp_read_buf(fd, unpack_data)) {
 		return FALSE;
 	}
 	if (!solid || !unpack_data->tables_read) {
 		rar_dbgmsg("Read tables\n");
 		if (!read_tables(fd, unpack_data)) {
 			return FALSE;
 		}
 	}
 
 	rar_dbgmsg("init done\n");
 	while(1) {
 		unpack_data->unp_ptr &= MAXWINMASK;
 		rar_dbgmsg("UnpPtr = %d\n", unpack_data->unp_ptr);
 		if (unpack_data->in_addr > unpack_data->read_border) {
 			if (!rar_unp_read_buf(fd, unpack_data)) {
 				retval = FALSE;
 				break;
 			}
 		}
 		if (((unpack_data->wr_ptr - unpack_data->unp_ptr) & MAXWINMASK) < 260 &&
 				unpack_data->wr_ptr != unpack_data->unp_ptr) {
 			unp_write_buf(unpack_data);
 		}
 		if (unpack_data->unp_block_type == BLOCK_PPM) {
 			ch = ppm_decode_char(&unpack_data->ppm_data, fd, unpack_data);
 			rar_dbgmsg("PPM char: %d\n", ch);
 			if (ch == -1) {

 				ppm_cleanup(&unpack_data->ppm_data);
 				unpack_data->unp_block_type = BLOCK_LZ;

 				retval = FALSE;
 				break;
 			}
 			if (ch == unpack_data->ppm_esc_char) {
 				next_ch = ppm_decode_char(&unpack_data->ppm_data,
 							fd, unpack_data);
 				rar_dbgmsg("PPM next char: %d\n", next_ch);
 				if (next_ch == -1) {
 					retval = FALSE;
 					break;
 				}
 				if (next_ch == 0) {
 					if (!read_tables(fd, unpack_data)) {
 						retval = FALSE;
 						break;
 					}
 					continue;
 				}
 				if (next_ch == 2 || next_ch == -1) {
 					break;
 				}
 				if (next_ch == 3) {
 					if (!read_vm_code_PPM(unpack_data, fd)) {
 						retval = FALSE;
 						break;
 					}
 					continue;
 				}
 				if (next_ch == 4) {

 					unsigned int length = 0;

 					distance = 0;
 					failed = FALSE;
 					for (i=0 ; i < 4 && !failed; i++) {
 						ch = ppm_decode_char(&unpack_data->ppm_data,
 								fd, unpack_data);
 						if (ch == -1) {
 							failed = TRUE;
 						} else {
 							if (i==3) {
 								length = (uint8_t)ch;
 							} else {
 								distance = (distance << 8) +
 										(uint8_t)ch;
 							}
 						}
 					}
 					if (failed) {
 						retval = FALSE;
 						break;
 					}
 					copy_string(unpack_data, length+32, distance+2);
 					continue;
 				}
 				if (next_ch == 5) {
 					int length = ppm_decode_char(&unpack_data->ppm_data,
 								fd, unpack_data);
 					rar_dbgmsg("PPM length: %d\n", length);
 					if (length == -1) {
 						retval = FALSE;
 						break;
 					}
 					copy_string(unpack_data, length+4, 1);
 					continue;
 				}
 			}
 			unpack_data->window[unpack_data->unp_ptr++] = ch;
 			continue;
 		} else {
 			number = rar_decode_number(unpack_data, (struct Decode *)&unpack_data->LD);
 			rar_dbgmsg("number = %d\n", number);
 			if (number < 256) {
 				unpack_data->window[unpack_data->unp_ptr++] = (uint8_t) number;
 				continue;
 			}
 			if (number >= 271) {
 				length = ldecode[number-=271]+3;
 				if ((bits=lbits[number]) > 0) {
 					length += rar_getbits(unpack_data) >> (16-bits);
 					rar_addbits(unpack_data, bits);
 				}
 				dist_number = rar_decode_number(unpack_data,
 							(struct Decode *)&unpack_data->DD);
 				distance = ddecode[dist_number] + 1;
 				if ((bits = dbits[dist_number]) > 0) {
 					if (dist_number > 9) {
 						if (bits > 4) {
 							distance += ((rar_getbits(unpack_data) >>
 									(20-bits)) << 4);
 							rar_addbits(unpack_data, bits-4);
 						}
 						if (unpack_data->low_dist_rep_count > 0) {
 							unpack_data->low_dist_rep_count--;
 							distance += unpack_data->prev_low_dist;
 						} else {
 							low_dist = rar_decode_number(unpack_data,
 								(struct Decode *) &unpack_data->LDD);
 							if (low_dist == 16) {
 								unpack_data->low_dist_rep_count =
 									LOW_DIST_REP_COUNT-1;
 								distance += unpack_data->prev_low_dist;
 							} else {
 								distance += low_dist;
 								unpack_data->prev_low_dist = low_dist;
 							}
 						}
 					} else {
 						distance += rar_getbits(unpack_data) >> (16-bits);
 						rar_addbits(unpack_data, bits);
 					}
 				}
 				
 				if (distance >= 0x2000) {
 					length++;
 					if (distance >= 0x40000L) {
 						length++;
 					}
 				}
 				
 				insert_old_dist(unpack_data, distance);
 				insert_last_match(unpack_data, length, distance);
 				copy_string(unpack_data, length, distance);
 				continue;
 			}
 			if (number == 256) {
 				if (!read_end_of_block(fd, unpack_data)) {
 					break;
 				}
 				continue;
 			}
 			if (number == 257) {
 				if (!read_vm_code(unpack_data, fd)) {
 					retval = FALSE;
 					break;
 				}
 				continue;
 			}
 			if (number == 258) {
 				if (unpack_data->last_length != 0) {
 					copy_string(unpack_data, unpack_data->last_length,
 							unpack_data->last_dist);
 				}
 				continue;
 			}
 			if (number < 263) {
 				dist_number = number-259;
 				distance = unpack_data->old_dist[dist_number];
 				for (i=dist_number ; i > 0 ; i--) {
 					unpack_data->old_dist[i] = unpack_data->old_dist[i-1];
 				}
 				unpack_data->old_dist[0] = distance;
 				
 				length_number = rar_decode_number(unpack_data,
 							(struct Decode *)&unpack_data->RD);
 				length = ldecode[length_number]+2;
 				if ((bits = lbits[length_number]) > 0) {
 					length += rar_getbits(unpack_data) >> (16-bits);
 					rar_addbits(unpack_data, bits);
 				}
 				insert_last_match(unpack_data, length, distance);
 				copy_string(unpack_data, length, distance);
 				continue;
 			}
 			if (number < 272) {
 				distance = sddecode[number-=263]+1;
 				if ((bits = sdbits[number]) > 0) {
 					distance += rar_getbits(unpack_data) >> (16-bits);
 					rar_addbits(unpack_data, bits);
 				}
 				insert_old_dist(unpack_data, distance);
 				insert_last_match(unpack_data, 2, distance);
 				copy_string(unpack_data, 2, distance);
 				continue;
 			}
 	
 		}
 	}
 	if (retval) {
 		unp_write_buf(unpack_data);
 	}
 	return retval;
 }
 
 int rar_unpack(int fd, int method, int solid, unpack_data_t *unpack_data)
 {
 	int retval = FALSE;
 	switch(method) {
 	case 15:
 		retval = rar_unpack15(fd, solid, unpack_data);
 		break;
 	case 20:
 	case 26:
 		retval = rar_unpack20(fd, solid, unpack_data);
 		break;
 	case 29:
 		retval = rar_unpack29(fd, solid, unpack_data);
 		break;
 	default:

 		retval = rar_unpack29(fd, solid, unpack_data);
 		if(retval == FALSE) {

 		    rarvm_free(&unpack_data->rarvm_data);

 		    retval = rar_unpack20(fd, solid, unpack_data);

 		    if(retval == FALSE) {
 			rarvm_free(&unpack_data->rarvm_data);

 			retval = rar_unpack15(fd, solid, unpack_data);

 		    }

 		}

 		break;
 	}

 	rar_dbgmsg("Written size: %ld\n", unpack_data->written_size);
 	rar_dbgmsg("True size: %ld\n", unpack_data->true_size);
 

 	return retval;
 }