Imanol-Mikel Barba Sabariego / libnbt · Commits

Commit 5ccd4c43035df90b493ebdfd40bf9afdc51579c0

Authored by Imanol-Mikel Barba Sabariego
1 parent 36186f24

Fixed region and relative chunk calculation from coords. Fixed bug when chunks w… 

…ere not generated in region file. Fixed potential crash when header length is 0
Inline Side-by-side
Showing 3 changed files with 28 additions and 11 deletions
... ... @@ -8,8 +8,8 @@ ssize_t loadChunk(const char* regionFolder, ChunkID chunk, void** chunkData);
8 8  
9 9 RegionID translateChunkToRegion(int x, int z) {
10 10 RegionID region;
11   - region.x = x/CHUNKS_PER_REGION;
12   - region.z = z/CHUNKS_PER_REGION;
  11 + region.x = floor((double)x/CHUNKS_PER_REGION);
  12 + region.z = floor((double)z/CHUNKS_PER_REGION);
13 13 return region;
14 14 }
15 15  
... ... @@ -20,16 +20,16 @@ RegionID translateCoordsToRegion(double x, double y, double z) {
20 20  
21 21 ChunkID translateCoordsToChunk(double x, double y, double z) {
22 22 ChunkID chunk;
23   - chunk.x = x/BLOCKS_PER_CHUNK;
24   - chunk.z = z/BLOCKS_PER_CHUNK;
  23 + chunk.x = floor((double)x/BLOCKS_PER_CHUNK);
  24 + chunk.z = floor((double)z/BLOCKS_PER_CHUNK);
25 25 return chunk;
26 26 }
27 27  
28 28 int overwriteChunk(const char* regionFolder, ChunkID chunk, void* chunkData, size_t chunkLength) {
29 29 RegionID region = translateChunkToRegion(chunk.x,chunk.z);
30 30 ChunkID relativeChunk;
31   - relativeChunk.x = chunk.x % 32;
32   - relativeChunk.z = chunk.z % 32;
  31 + relativeChunk.x = chunk.x & 31;
  32 + relativeChunk.z = chunk.z & 31;
33 33  
34 34 char* regionFilename = calloc(MAX_REGION_FILENAME_LENGTH + strlen(regionFolder),sizeof(char));
35 35 sprintf(regionFilename,"%s/r.%d.%d.mca",regionFolder,region.x,region.z);
... ... @@ -110,8 +110,8 @@ int overwriteChunk(const char* regionFolder, ChunkID chunk, void* chunkData, siz
110 110 ssize_t loadChunk(const char* regionFolder, ChunkID chunk, void** chunkData) {
111 111 RegionID region = translateChunkToRegion(chunk.x,chunk.z);
112 112 ChunkID relativeChunk;
113   - relativeChunk.x = chunk.x % 32;
114   - relativeChunk.z = chunk.z % 32;
  113 + relativeChunk.x = chunk.x & 31;
  114 + relativeChunk.z = chunk.z & 31;
115 115  
116 116 char* regionFilename = calloc(MAX_REGION_FILENAME_LENGTH + strlen(regionFolder),sizeof(char));
117 117 sprintf(regionFilename,"%s/r.%d.%d.mca",regionFolder,region.x,region.z);
... ... @@ -135,6 +135,11 @@ ssize_t loadChunk(const char* regionFolder, ChunkID chunk, void** chunkData) {
135 135 return -3;
136 136 }
137 137 chunkHeaderOffset = (__bswap_32(chunkHeaderOffset & 0x00FFFFFF) >> 8) * CHUNK_SECTOR_SIZE;
  138 + if(chunkHeaderOffset == 0) {
  139 + // Chunk not present. Hasn't been generated
  140 + close(fd);
  141 + return 0;
  142 + }
138 143  
139 144 if(lseek(fd,chunkHeaderOffset,SEEK_SET) == -1) {
140 145 close(fd);
... ... @@ -150,6 +155,16 @@ ssize_t loadChunk(const char* regionFolder, ChunkID chunk, void** chunkData) {
150 155 }
151 156 header.length = __bswap_32(header.length);
152 157 ssize_t chunkLength = header.length;
  158 + if(header.compressionType != COMPRESSION_TYPE_ZLIB && header.compressionType != COMPRESSION_TYPE_GZIP) {
  159 + fprintf(stderr, "Invalid compression method. Proably reading the wrong data for the header\n");
  160 + close(fd);
  161 + return -6;
  162 + }
  163 + if(header.length == 0) {
  164 + fprintf(stderr, "Header length is 0. Probably reading the wrong data for the header\n");
  165 + close(fd);
  166 + return -7;
  167 + }
153 168  
154 169 void* compressedChunk = calloc(chunkLength,sizeof(char));
155 170 ssize_t nRead = 0;
... ... @@ -163,7 +178,7 @@ ssize_t loadChunk(const char* regionFolder, ChunkID chunk, void** chunkData) {
163 178 fprintf(stderr,"Unable to read chunk: %s\n",strerror(errno));
164 179 close(fd);
165 180 free(compressedChunk);
166   - return -6;
  181 + return -8;
167 182 }
168 183 totalRead += nRead;
169 184 }
... ... @@ -174,7 +189,8 @@ ssize_t loadChunk(const char* regionFolder, ChunkID chunk, void** chunkData) {
174 189  
175 190 if(chunkLength <= 0) {
176 191 fprintf(stderr,"Error while decompressing chunk\n");
177   - return -8;
  192 + free(compressedChunk);
  193 + return -9;
178 194 }
179 195 free(compressedChunk);
180 196  
... ...
... ... @@ -9,6 +9,7 @@
9 9 #include <stdint.h>
10 10 #include <string.h>
11 11 #include <byteswap.h>
  12 +#include <math.h>
12 13  
13 14 #include "compression.h"
14 15  
... ...
compression.c
  View file @5ccd4c4
... ... @@ -45,7 +45,7 @@ ssize_t inflateGzip(void* compData, size_t compDataLen, void** unCompData, int h
45 45 strm.avail_out = uncompLength - strm.total_out;
46 46  
47 47 // Inflate another chunk.
48   - err = inflate (&strm, Z_SYNC_FLUSH);
  48 + err = inflate(&strm, Z_SYNC_FLUSH);
49 49 if(err != Z_OK && err != Z_STREAM_END) {
50 50 fprintf(stderr, "Error while inflating buffer: %d - %s.\n", err,strm.msg);
51 51 inflateEnd(&strm);
... ...