diff options
Diffstat (limited to 'mpq-bios.c')
| -rw-r--r-- | mpq-bios.c | 31 |
1 files changed, 31 insertions, 0 deletions
@@ -14,6 +14,10 @@ #include "errors.h" #include "inttypes.h" +/* + * MPQ header. + */ + typedef struct { /* basic version of the header. */ char magic[4]; @@ -33,6 +37,10 @@ typedef struct { uint16_t block_table_offset_high; } __attribute__ ((packed)) mpq_header_t; +/* + * One hash entry. + */ + typedef struct { uint32_t file_path_hasha; uint32_t file_path_hashb; @@ -41,6 +49,10 @@ typedef struct { uint32_t file_block_index; } __attribute__ ((packed)) mpq_hash_t; +/* + * One block entry. + */ + typedef struct { uint32_t block_offset; uint32_t block_size; @@ -48,6 +60,11 @@ typedef struct { uint32_t flags; } __attribute__ ((packed)) mpq_block_t; + +/* + * This are our internal structures. + */ + typedef struct { uint32_t file_path_hasha; uint32_t file_path_hashb; @@ -169,15 +186,18 @@ struct mpq_archive_t * mpqlib_reopen_archive(int fd) { mpq_a->closeit = 0; mpq_a->fd = fd; + /* Reading the main header, and doing basic checks. */ if (read(fd, &mpq_h, STD_HEADER_SIZE) != STD_HEADER_SIZE) no_mpq(); if (strncmp(mpq_h.magic, "MPQ\x1a", 4)) no_mpq(); + /* format_version can only be 0 or 1 - the latter beeing for Burning Crusade */ if ((mpq_h.format_version | 1) != 1) no_mpq(); + /* If the format is extended, let's read the extra data, otherwise let's fill it with zeroes */ if (mpq_h.format_version == 1) { if (!read_data(mpq_a, ((char *)(&mpq_h)) + STD_HEADER_SIZE, EXT_HEADER_SIZE)) no_mpq(); @@ -187,6 +207,7 @@ struct mpq_archive_t * mpqlib_reopen_archive(int fd) { mpq_h.block_table_offset_high = 0; } + /* Let's start copying / interpreting / rebuilding basic header data */ mpq_a->header_size = mpq_h.header_size; mpq_a->archive_size = mpq_h.archive_size; mpq_a->format_version = mpq_h.format_version; @@ -198,6 +219,7 @@ struct mpq_archive_t * mpqlib_reopen_archive(int fd) { mpq_a->block_table_entries = mpq_h.block_table_entries; mpq_a->extended_block_table_offset = mpq_h.extended_block_table_offset; + /* Allocation and reading of our hash and block tables */ if (!(mpq_a->hashs = (hash_t *) malloc(mpq_a->hash_table_entries * sizeof(hash_t)))) { __mpqlib_errno = MPQLIB_ERROR_MEMORY; free(mpq_a); @@ -252,9 +274,11 @@ struct mpq_archive_t * mpqlib_reopen_archive(int fd) { } } + /* Hash and block table are (easily) encrypted - let's decrypt them before going on any further */ __mpqlib_decrypt(mpq_hashs, mpq_a->hash_table_entries * sizeof(mpq_block_t), __mpqlib_hash_cstring("(hash table)", 3), 1); __mpqlib_decrypt(mpq_blocks, mpq_a->block_table_entries * sizeof(mpq_block_t), __mpqlib_hash_cstring("(block table)", 3), 1); + /* Copying / interpreting / rebuilding of the hash table. */ for (i = 0; i < mpq_a->hash_table_entries; i++) { /****TODO****/ /* Implement various checks of the hash table. */ @@ -265,6 +289,7 @@ struct mpq_archive_t * mpqlib_reopen_archive(int fd) { mpq_a->hashs[i].file_block_index = mpq_hashs[i].file_block_index; } + /* Copying / interpreting / rebuilding of the block table. */ for (i = 0; i < mpq_a->block_table_entries; i++) { /****TODO****/ /* Implement various checks of the block table. */ @@ -274,6 +299,7 @@ struct mpq_archive_t * mpqlib_reopen_archive(int fd) { mpq_a->blocks[i].flags = mpq_blocks[i].flags; } + /* All done, let's clean up and exit. */ if (mpq_extblocks) free(mpq_extblocks); @@ -283,6 +309,10 @@ struct mpq_archive_t * mpqlib_reopen_archive(int fd) { return mpq_a; } +/* + * Verbose display of an archive. + */ + void mpqlib_printtables(struct mpq_archive_t * mpq_a) { int i; @@ -327,6 +357,7 @@ int mpqlib_find_hash_entry_by_name(struct mpq_archive_t * mpq_a, const char * na int mpqlib_find_hash_entry_by_hash(struct mpq_archive_t * mpq_a, uint32_t h, uint32_t hA, uint32_t hB, uint32_t language, uint32_t platform) { int i; + /* The hash table is a true one, pre-built. We can access it as-it, speeding up the searches drastically. */ for (i = h & (mpq_a->hash_table_entries - 1); i < mpq_a->hash_table_entries; i++) { if ((mpq_a->hashs[i].file_path_hasha == hA) && (mpq_a->hashs[i].file_path_hashb == hB) && |