misc/libphysfs/archiver_mvl.c
author nemo
Mon, 10 Apr 2017 12:06:43 -0400
changeset 12218 bb5522e88ab2
parent 8524 a65e9bcf0a03
permissions -rw-r--r--
bulk copy of latest physfs to our misc/libphysfs since this seems to fix an off-by-1 error reliably hit in readln read of 1 byte probably introduced in the addition of the buffered read. Whether this is excessive or whether libphysfs should even be maintained by us is another matter. But at least we shouldn't crash

/*
 * MVL support routines for PhysicsFS.
 *
 * This driver handles Descent II Movielib archives.
 *
 * The file format of MVL is quite easy...
 *
 *   //MVL File format - Written by Heiko Herrmann
 *   char sig[4] = {'D','M', 'V', 'L'}; // "DMVL"=Descent MoVie Library
 *
 *   int num_files; // the number of files in this MVL
 *
 *   struct {
 *    char file_name[13]; // Filename, padded to 13 bytes with 0s
 *    int file_size; // filesize in bytes
 *   }DIR_STRUCT[num_files];
 *
 *   struct {
 *    char data[file_size]; // The file data
 *   }FILE_STRUCT[num_files];
 *
 * (That info is from http://www.descent2.com/ddn/specs/mvl/)
 *
 * Please see the file LICENSE.txt in the source's root directory.
 *
 *  This file written by Bradley Bell.
 *  Based on grp.c by Ryan C. Gordon.
 */

#define __PHYSICSFS_INTERNAL__
#include "physfs_internal.h"

#if PHYSFS_SUPPORTS_MVL

static UNPKentry *mvlLoadEntries(PHYSFS_Io *io, PHYSFS_uint32 fileCount)
{
    PHYSFS_uint32 location = 8;  /* sizeof sig. */
    UNPKentry *entries = NULL;
    UNPKentry *entry = NULL;

    entries = (UNPKentry *) allocator.Malloc(sizeof (UNPKentry) * fileCount);
    BAIL_IF_MACRO(entries == NULL, PHYSFS_ERR_OUT_OF_MEMORY, NULL);

    location += (17 * fileCount);

    for (entry = entries; fileCount > 0; fileCount--, entry++)
    {
        if (!__PHYSFS_readAll(io, &entry->name, 13)) goto failed;
        if (!__PHYSFS_readAll(io, &entry->size, 4)) goto failed;
        entry->size = PHYSFS_swapULE32(entry->size);
        entry->startPos = location;
        location += entry->size;
    } /* for */

    return entries;

failed:
    allocator.Free(entries);
    return NULL;
} /* mvlLoadEntries */


static void *MVL_openArchive(PHYSFS_Io *io, const char *name, int forWriting)
{
    PHYSFS_uint8 buf[4];
    PHYSFS_uint32 count = 0;
    UNPKentry *entries = NULL;

    assert(io != NULL);  /* shouldn't ever happen. */
    BAIL_IF_MACRO(forWriting, PHYSFS_ERR_READ_ONLY, NULL);
    BAIL_IF_MACRO(!__PHYSFS_readAll(io, buf, 4), ERRPASS, NULL);
    BAIL_IF_MACRO(memcmp(buf, "DMVL", 4) != 0, PHYSFS_ERR_UNSUPPORTED, NULL);
    BAIL_IF_MACRO(!__PHYSFS_readAll(io, &count, sizeof(count)), ERRPASS, NULL);

    count = PHYSFS_swapULE32(count);
    entries = mvlLoadEntries(io, count);
    return (!entries) ? NULL : UNPK_openArchive(io, entries, count);
} /* MVL_openArchive */


const PHYSFS_Archiver __PHYSFS_Archiver_MVL =
{
    CURRENT_PHYSFS_ARCHIVER_API_VERSION,
    {
        "MVL",
        "Descent II Movielib format",
        "Bradley Bell <btb@icculus.org>",
        "https://icculus.org/physfs/",
        0,  /* supportsSymlinks */
    },
    MVL_openArchive,
    UNPK_enumerateFiles,
    UNPK_openRead,
    UNPK_openWrite,
    UNPK_openAppend,
    UNPK_remove,
    UNPK_mkdir,
    UNPK_stat,
    UNPK_closeArchive
};

#endif  /* defined PHYSFS_SUPPORTS_MVL */

/* end of archiver_mvl.c ... */