misc/physfs/src/archiver_zip.c
branchphysfslayer
changeset 7768 13e2037ebc79
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/physfs/src/archiver_zip.c	Sat Oct 20 00:20:39 2012 +0400
@@ -0,0 +1,1717 @@
+/*
+ * ZIP support routines for PhysicsFS.
+ *
+ * Please see the file LICENSE.txt in the source's root directory.
+ *
+ *  This file written by Ryan C. Gordon, with some peeking at "unzip.c"
+ *   by Gilles Vollant.
+ */
+
+#define __PHYSICSFS_INTERNAL__
+#include "physfs_internal.h"
+
+#if PHYSFS_SUPPORTS_ZIP
+
+#include <errno.h>
+#include <time.h>
+
+#define USE_MINIZ 1
+#if USE_MINIZ
+#include "physfs_miniz.h"
+#else
+#include <zlib.h>
+#endif
+
+/*
+ * A buffer of ZIP_READBUFSIZE is allocated for each compressed file opened,
+ *  and is freed when you close the file; compressed data is read into
+ *  this buffer, and then is decompressed into the buffer passed to
+ *  PHYSFS_read().
+ *
+ * Uncompressed entries in a zipfile do not allocate this buffer; they just
+ *  read data directly into the buffer passed to PHYSFS_read().
+ *
+ * Depending on your speed and memory requirements, you should tweak this
+ *  value.
+ */
+#define ZIP_READBUFSIZE   (16 * 1024)
+
+
+/*
+ * Entries are "unresolved" until they are first opened. At that time,
+ *  local file headers parsed/validated, data offsets will be updated to look
+ *  at the actual file data instead of the header, and symlinks will be
+ *  followed and optimized. This means that we don't seek and read around the
+ *  archive until forced to do so, and after the first time, we had to do
+ *  less reading and parsing, which is very CD-ROM friendly.
+ */
+typedef enum
+{
+    ZIP_UNRESOLVED_FILE,
+    ZIP_UNRESOLVED_SYMLINK,
+    ZIP_RESOLVING,
+    ZIP_RESOLVED,
+    ZIP_BROKEN_FILE,
+    ZIP_BROKEN_SYMLINK
+} ZipResolveType;
+
+
+/*
+ * One ZIPentry is kept for each file in an open ZIP archive.
+ */
+typedef struct _ZIPentry
+{
+    char *name;                         /* Name of file in archive        */
+    struct _ZIPentry *symlink;          /* NULL or file we symlink to     */
+    ZipResolveType resolved;            /* Have we resolved file/symlink? */
+    PHYSFS_uint64 offset;               /* offset of data in archive      */
+    PHYSFS_uint16 version;              /* version made by                */
+    PHYSFS_uint16 version_needed;       /* version needed to extract      */
+    PHYSFS_uint16 compression_method;   /* compression method             */
+    PHYSFS_uint32 crc;                  /* crc-32                         */
+    PHYSFS_uint64 compressed_size;      /* compressed size                */
+    PHYSFS_uint64 uncompressed_size;    /* uncompressed size              */
+    PHYSFS_sint64 last_mod_time;        /* last file mod time             */
+} ZIPentry;
+
+/*
+ * One ZIPinfo is kept for each open ZIP archive.
+ */
+typedef struct
+{
+    PHYSFS_Io *io;
+    int zip64;                /* non-zero if this is a Zip64 archive. */
+    PHYSFS_uint64 entryCount; /* Number of files in ZIP.              */
+    ZIPentry *entries;        /* info on all files in ZIP.            */
+} ZIPinfo;
+
+/*
+ * One ZIPfileinfo is kept for each open file in a ZIP archive.
+ */
+typedef struct
+{
+    ZIPentry *entry;                      /* Info on file.              */
+    PHYSFS_Io *io;                        /* physical file handle.      */
+    PHYSFS_uint32 compressed_position;    /* offset in compressed data. */
+    PHYSFS_uint32 uncompressed_position;  /* tell() position.           */
+    PHYSFS_uint8 *buffer;                 /* decompression buffer.      */
+    z_stream stream;                      /* zlib stream state.         */
+} ZIPfileinfo;
+
+
+/* Magic numbers... */
+#define ZIP_LOCAL_FILE_SIG                          0x04034b50
+#define ZIP_CENTRAL_DIR_SIG                         0x02014b50
+#define ZIP_END_OF_CENTRAL_DIR_SIG                  0x06054b50
+#define ZIP64_END_OF_CENTRAL_DIR_SIG                0x06064b50
+#define ZIP64_END_OF_CENTRAL_DIRECTORY_LOCATOR_SIG  0x07064b50
+#define ZIP64_EXTENDED_INFO_EXTRA_FIELD_SIG         0x0001
+
+/* compression methods... */
+#define COMPMETH_NONE 0
+/* ...and others... */
+
+
+#define UNIX_FILETYPE_MASK    0170000
+#define UNIX_FILETYPE_SYMLINK 0120000
+
+
+/*
+ * Bridge physfs allocation functions to zlib's format...
+ */
+static voidpf zlibPhysfsAlloc(voidpf opaque, uInt items, uInt size)
+{
+    return ((PHYSFS_Allocator *) opaque)->Malloc(items * size);
+} /* zlibPhysfsAlloc */
+
+/*
+ * Bridge physfs allocation functions to zlib's format...
+ */
+static void zlibPhysfsFree(voidpf opaque, voidpf address)
+{
+    ((PHYSFS_Allocator *) opaque)->Free(address);
+} /* zlibPhysfsFree */
+
+
+/*
+ * Construct a new z_stream to a sane state.
+ */
+static void initializeZStream(z_stream *pstr)
+{
+    memset(pstr, '\0', sizeof (z_stream));
+    pstr->zalloc = zlibPhysfsAlloc;
+    pstr->zfree = zlibPhysfsFree;
+    pstr->opaque = &allocator;
+} /* initializeZStream */
+
+
+static PHYSFS_ErrorCode zlib_error_code(int rc)
+{
+    switch (rc)
+    {
+        case Z_OK: return PHYSFS_ERR_OK;  /* not an error. */
+        case Z_STREAM_END: return PHYSFS_ERR_OK; /* not an error. */
+        case Z_ERRNO: return PHYSFS_ERR_IO;
+        case Z_MEM_ERROR: return PHYSFS_ERR_OUT_OF_MEMORY;
+        default: return PHYSFS_ERR_CORRUPT;
+    } /* switch */
+} /* zlib_error_string */
+
+
+/*
+ * Wrap all zlib calls in this, so the physfs error state is set appropriately.
+ */
+static int zlib_err(const int rc)
+{
+    __PHYSFS_setError(zlib_error_code(rc));
+    return rc;
+} /* zlib_err */
+
+
+/*
+ * Read an unsigned 64-bit int and swap to native byte order.
+ */
+static int readui64(PHYSFS_Io *io, PHYSFS_uint64 *val)
+{
+    PHYSFS_uint64 v;
+    BAIL_IF_MACRO(!__PHYSFS_readAll(io, &v, sizeof (v)), ERRPASS, 0);
+    *val = PHYSFS_swapULE64(v);
+    return 1;
+} /* readui64 */
+
+/*
+ * Read an unsigned 32-bit int and swap to native byte order.
+ */
+static int readui32(PHYSFS_Io *io, PHYSFS_uint32 *val)
+{
+    PHYSFS_uint32 v;
+    BAIL_IF_MACRO(!__PHYSFS_readAll(io, &v, sizeof (v)), ERRPASS, 0);
+    *val = PHYSFS_swapULE32(v);
+    return 1;
+} /* readui32 */
+
+
+/*
+ * Read an unsigned 16-bit int and swap to native byte order.
+ */
+static int readui16(PHYSFS_Io *io, PHYSFS_uint16 *val)
+{
+    PHYSFS_uint16 v;
+    BAIL_IF_MACRO(!__PHYSFS_readAll(io, &v, sizeof (v)), ERRPASS, 0);
+    *val = PHYSFS_swapULE16(v);
+    return 1;
+} /* readui16 */
+
+
+static PHYSFS_sint64 ZIP_read(PHYSFS_Io *_io, void *buf, PHYSFS_uint64 len)
+{
+    ZIPfileinfo *finfo = (ZIPfileinfo *) _io->opaque;
+    PHYSFS_Io *io = finfo->io;
+    ZIPentry *entry = finfo->entry;
+    PHYSFS_sint64 retval = 0;
+    PHYSFS_sint64 maxread = (PHYSFS_sint64) len;
+    PHYSFS_sint64 avail = entry->uncompressed_size -
+                          finfo->uncompressed_position;
+
+    if (avail < maxread)
+        maxread = avail;
+
+    BAIL_IF_MACRO(maxread == 0, ERRPASS, 0);    /* quick rejection. */
+
+    if (entry->compression_method == COMPMETH_NONE)
+        retval = io->read(io, buf, maxread);
+    else
+    {
+        finfo->stream.next_out = buf;
+        finfo->stream.avail_out = (uInt) maxread;
+
+        while (retval < maxread)
+        {
+            PHYSFS_uint32 before = finfo->stream.total_out;
+            int rc;
+
+            if (finfo->stream.avail_in == 0)
+            {
+                PHYSFS_sint64 br;
+
+                br = entry->compressed_size - finfo->compressed_position;
+                if (br > 0)
+                {
+                    if (br > ZIP_READBUFSIZE)
+                        br = ZIP_READBUFSIZE;
+
+                    br = io->read(io, finfo->buffer, (PHYSFS_uint64) br);
+                    if (br <= 0)
+                        break;
+
+                    finfo->compressed_position += (PHYSFS_uint32) br;
+                    finfo->stream.next_in = finfo->buffer;
+                    finfo->stream.avail_in = (PHYSFS_uint32) br;
+                } /* if */
+            } /* if */
+
+            rc = zlib_err(inflate(&finfo->stream, Z_SYNC_FLUSH));
+            retval += (finfo->stream.total_out - before);
+
+            if (rc != Z_OK)
+                break;
+        } /* while */
+    } /* else */
+
+    if (retval > 0)
+        finfo->uncompressed_position += (PHYSFS_uint32) retval;
+
+    return retval;
+} /* ZIP_read */
+
+
+static PHYSFS_sint64 ZIP_write(PHYSFS_Io *io, const void *b, PHYSFS_uint64 len)
+{
+    BAIL_MACRO(PHYSFS_ERR_READ_ONLY, -1);
+} /* ZIP_write */
+
+
+static PHYSFS_sint64 ZIP_tell(PHYSFS_Io *io)
+{
+    return ((ZIPfileinfo *) io->opaque)->uncompressed_position;
+} /* ZIP_tell */
+
+
+static int ZIP_seek(PHYSFS_Io *_io, PHYSFS_uint64 offset)
+{
+    ZIPfileinfo *finfo = (ZIPfileinfo *) _io->opaque;
+    ZIPentry *entry = finfo->entry;
+    PHYSFS_Io *io = finfo->io;
+
+    BAIL_IF_MACRO(offset > entry->uncompressed_size, PHYSFS_ERR_PAST_EOF, 0);
+
+    if (entry->compression_method == COMPMETH_NONE)
+    {
+        const PHYSFS_sint64 newpos = offset + entry->offset;
+        BAIL_IF_MACRO(!io->seek(io, newpos), ERRPASS, 0);
+        finfo->uncompressed_position = (PHYSFS_uint32) offset;
+    } /* if */
+
+    else
+    {
+        /*
+         * If seeking backwards, we need to redecode the file
+         *  from the start and throw away the compressed bits until we hit
+         *  the offset we need. If seeking forward, we still need to
+         *  decode, but we don't rewind first.
+         */
+        if (offset < finfo->uncompressed_position)
+        {
+            /* we do a copy so state is sane if inflateInit2() fails. */
+            z_stream str;
+            initializeZStream(&str);
+            if (zlib_err(inflateInit2(&str, -MAX_WBITS)) != Z_OK)
+                return 0;
+
+            if (!io->seek(io, entry->offset))
+                return 0;
+
+            inflateEnd(&finfo->stream);
+            memcpy(&finfo->stream, &str, sizeof (z_stream));
+            finfo->uncompressed_position = finfo->compressed_position = 0;
+        } /* if */
+
+        while (finfo->uncompressed_position != offset)
+        {
+            PHYSFS_uint8 buf[512];
+            PHYSFS_uint32 maxread;
+
+            maxread = (PHYSFS_uint32) (offset - finfo->uncompressed_position);
+            if (maxread > sizeof (buf))
+                maxread = sizeof (buf);
+
+            if (ZIP_read(_io, buf, maxread) != maxread)
+                return 0;
+        } /* while */
+    } /* else */
+
+    return 1;
+} /* ZIP_seek */
+
+
+static PHYSFS_sint64 ZIP_length(PHYSFS_Io *io)
+{
+    const ZIPfileinfo *finfo = (ZIPfileinfo *) io->opaque;
+    return (PHYSFS_sint64) finfo->entry->uncompressed_size;
+} /* ZIP_length */
+
+
+static PHYSFS_Io *zip_get_io(PHYSFS_Io *io, ZIPinfo *inf, ZIPentry *entry);
+
+static PHYSFS_Io *ZIP_duplicate(PHYSFS_Io *io)
+{
+    ZIPfileinfo *origfinfo = (ZIPfileinfo *) io->opaque;
+    PHYSFS_Io *retval = (PHYSFS_Io *) allocator.Malloc(sizeof (PHYSFS_Io));
+    ZIPfileinfo *finfo = (ZIPfileinfo *) allocator.Malloc(sizeof (ZIPfileinfo));
+    GOTO_IF_MACRO(!retval, PHYSFS_ERR_OUT_OF_MEMORY, failed);
+    GOTO_IF_MACRO(!finfo, PHYSFS_ERR_OUT_OF_MEMORY, failed);
+    memset(finfo, '\0', sizeof (*finfo));
+
+    finfo->entry = origfinfo->entry;
+    finfo->io = zip_get_io(origfinfo->io, NULL, finfo->entry);
+    GOTO_IF_MACRO(!finfo->io, ERRPASS, failed);
+
+    if (finfo->entry->compression_method != COMPMETH_NONE)
+    {
+        finfo->buffer = (PHYSFS_uint8 *) allocator.Malloc(ZIP_READBUFSIZE);
+        GOTO_IF_MACRO(!finfo->buffer, PHYSFS_ERR_OUT_OF_MEMORY, failed);
+        if (zlib_err(inflateInit2(&finfo->stream, -MAX_WBITS)) != Z_OK)
+            goto failed;
+    } /* if */
+
+    memcpy(retval, io, sizeof (PHYSFS_Io));
+    retval->opaque = finfo;
+    return retval;
+
+failed:
+    if (finfo != NULL)
+    {
+        if (finfo->io != NULL)
+            finfo->io->destroy(finfo->io);
+
+        if (finfo->buffer != NULL)
+        {
+            allocator.Free(finfo->buffer);
+            inflateEnd(&finfo->stream);
+        } /* if */
+
+        allocator.Free(finfo);
+    } /* if */
+
+    if (retval != NULL)
+        allocator.Free(retval);
+
+    return NULL;
+} /* ZIP_duplicate */
+
+static int ZIP_flush(PHYSFS_Io *io) { return 1;  /* no write support. */ }
+
+static void ZIP_destroy(PHYSFS_Io *io)
+{
+    ZIPfileinfo *finfo = (ZIPfileinfo *) io->opaque;
+    finfo->io->destroy(finfo->io);
+
+    if (finfo->entry->compression_method != COMPMETH_NONE)
+        inflateEnd(&finfo->stream);
+
+    if (finfo->buffer != NULL)
+        allocator.Free(finfo->buffer);
+
+    allocator.Free(finfo);
+    allocator.Free(io);
+} /* ZIP_destroy */
+
+
+static const PHYSFS_Io ZIP_Io =
+{
+    CURRENT_PHYSFS_IO_API_VERSION, NULL,
+    ZIP_read,
+    ZIP_write,
+    ZIP_seek,
+    ZIP_tell,
+    ZIP_length,
+    ZIP_duplicate,
+    ZIP_flush,
+    ZIP_destroy
+};
+
+
+
+static PHYSFS_sint64 zip_find_end_of_central_dir(PHYSFS_Io *io, PHYSFS_sint64 *len)
+{
+    PHYSFS_uint8 buf[256];
+    PHYSFS_uint8 extra[4] = { 0, 0, 0, 0 };
+    PHYSFS_sint32 i = 0;
+    PHYSFS_sint64 filelen;
+    PHYSFS_sint64 filepos;
+    PHYSFS_sint32 maxread;
+    PHYSFS_sint32 totalread = 0;
+    int found = 0;
+
+    filelen = io->length(io);
+    BAIL_IF_MACRO(filelen == -1, ERRPASS, 0);
+
+    /*
+     * Jump to the end of the file and start reading backwards.
+     *  The last thing in the file is the zipfile comment, which is variable
+     *  length, and the field that specifies its size is before it in the
+     *  file (argh!)...this means that we need to scan backwards until we
+     *  hit the end-of-central-dir signature. We can then sanity check that
+     *  the comment was as big as it should be to make sure we're in the
+     *  right place. The comment length field is 16 bits, so we can stop
+     *  searching for that signature after a little more than 64k at most,
+     *  and call it a corrupted zipfile.
+     */
+
+    if (sizeof (buf) < filelen)
+    {
+        filepos = filelen - sizeof (buf);
+        maxread = sizeof (buf);
+    } /* if */
+    else
+    {
+        filepos = 0;
+        maxread = (PHYSFS_uint32) filelen;
+    } /* else */
+
+    while ((totalread < filelen) && (totalread < 65557))
+    {
+        BAIL_IF_MACRO(!io->seek(io, filepos), ERRPASS, -1);
+
+        /* make sure we catch a signature between buffers. */
+        if (totalread != 0)
+        {
+            if (!__PHYSFS_readAll(io, buf, maxread - 4))
+                return -1;
+            memcpy(&buf[maxread - 4], &extra, sizeof (extra));
+            totalread += maxread - 4;
+        } /* if */
+        else
+        {
+            if (!__PHYSFS_readAll(io, buf, maxread))
+                return -1;
+            totalread += maxread;
+        } /* else */
+
+        memcpy(&extra, buf, sizeof (extra));
+
+        for (i = maxread - 4; i > 0; i--)
+        {
+            if ((buf[i + 0] == 0x50) &&
+                (buf[i + 1] == 0x4B) &&
+                (buf[i + 2] == 0x05) &&
+                (buf[i + 3] == 0x06) )
+            {
+                found = 1;  /* that's the signature! */
+                break;  
+            } /* if */
+        } /* for */
+
+        if (found)
+            break;
+
+        filepos -= (maxread - 4);
+        if (filepos < 0)
+            filepos = 0;
+    } /* while */
+
+    BAIL_IF_MACRO(!found, PHYSFS_ERR_UNSUPPORTED, -1);
+
+    if (len != NULL)
+        *len = filelen;
+
+    return (filepos + i);
+} /* zip_find_end_of_central_dir */
+
+
+static int isZip(PHYSFS_Io *io)
+{
+    PHYSFS_uint32 sig = 0;
+    int retval = 0;
+
+    /*
+     * The first thing in a zip file might be the signature of the
+     *  first local file record, so it makes for a quick determination.
+     */
+    if (readui32(io, &sig))
+    {
+        retval = (sig == ZIP_LOCAL_FILE_SIG);
+        if (!retval)
+        {
+            /*
+             * No sig...might be a ZIP with data at the start
+             *  (a self-extracting executable, etc), so we'll have to do
+             *  it the hard way...
+             */
+            retval = (zip_find_end_of_central_dir(io, NULL) != -1);
+        } /* if */
+    } /* if */
+
+    return retval;
+} /* isZip */
+
+
+static void zip_free_entries(ZIPentry *entries, PHYSFS_uint64 max)
+{
+    PHYSFS_uint64 i;
+    for (i = 0; i < max; i++)
+    {
+        ZIPentry *entry = &entries[i];
+        if (entry->name != NULL)
+            allocator.Free(entry->name);
+    } /* for */
+
+    allocator.Free(entries);
+} /* zip_free_entries */
+
+
+/*
+ * This will find the ZIPentry associated with a path in platform-independent
+ *  notation. Directories don't have ZIPentries associated with them, but 
+ *  (*isDir) will be set to non-zero if a dir was hit.
+ */
+static ZIPentry *zip_find_entry(const ZIPinfo *info, const char *path,
+                                int *isDir)
+{
+    ZIPentry *a = info->entries;
+    PHYSFS_sint32 pathlen = (PHYSFS_sint32) strlen(path);
+    PHYSFS_sint64 lo = 0;
+    PHYSFS_sint64 hi = (PHYSFS_sint64) (info->entryCount - 1);
+    PHYSFS_sint64 middle;
+    const char *thispath = NULL;
+    int rc;
+
+    while (lo <= hi)
+    {
+        middle = lo + ((hi - lo) / 2);
+        thispath = a[middle].name;
+        rc = strncmp(path, thispath, pathlen);
+
+        if (rc > 0)
+            lo = middle + 1;
+
+        else if (rc < 0)
+            hi = middle - 1;
+
+        else /* substring match...might be dir or entry or nothing. */
+        {
+            if (isDir != NULL)
+            {
+                *isDir = (thispath[pathlen] == '/');
+                if (*isDir)
+                    return NULL;
+            } /* if */
+
+            if (thispath[pathlen] == '\0') /* found entry? */
+                return &a[middle];
+            /* adjust search params, try again. */
+            else if (thispath[pathlen] > '/')
+                hi = middle - 1;
+            else
+                lo = middle + 1;
+        } /* if */
+    } /* while */
+
+    if (isDir != NULL)
+        *isDir = 0;
+
+    BAIL_MACRO(PHYSFS_ERR_NO_SUCH_PATH, NULL);
+} /* zip_find_entry */
+
+
+/* Convert paths from old, buggy DOS zippers... */
+static void zip_convert_dos_path(ZIPentry *entry, char *path)
+{
+    PHYSFS_uint8 hosttype = (PHYSFS_uint8) ((entry->version >> 8) & 0xFF);
+    if (hosttype == 0)  /* FS_FAT_ */
+    {
+        while (*path)
+        {
+            if (*path == '\\')
+                *path = '/';
+            path++;
+        } /* while */
+    } /* if */
+} /* zip_convert_dos_path */
+
+
+static void zip_expand_symlink_path(char *path)
+{
+    char *ptr = path;
+    char *prevptr = path;
+
+    while (1)
+    {
+        ptr = strchr(ptr, '/');
+        if (ptr == NULL)
+            break;
+
+        if (*(ptr + 1) == '.')
+        {
+            if (*(ptr + 2) == '/')
+            {
+                /* current dir in middle of string: ditch it. */
+                memmove(ptr, ptr + 2, strlen(ptr + 2) + 1);
+            } /* else if */
+
+            else if (*(ptr + 2) == '\0')
+            {
+                /* current dir at end of string: ditch it. */
+                *ptr = '\0';
+            } /* else if */
+
+            else if (*(ptr + 2) == '.')
+            {
+                if (*(ptr + 3) == '/')
+                {
+                    /* parent dir in middle: move back one, if possible. */
+                    memmove(prevptr, ptr + 4, strlen(ptr + 4) + 1);
+                    ptr = prevptr;
+                    while (prevptr != path)
+                    {
+                        prevptr--;
+                        if (*prevptr == '/')
+                        {
+                            prevptr++;
+                            break;
+                        } /* if */
+                    } /* while */
+                } /* if */
+
+                if (*(ptr + 3) == '\0')
+                {
+                    /* parent dir at end: move back one, if possible. */
+                    *prevptr = '\0';
+                } /* if */
+            } /* if */
+        } /* if */
+        else
+        {
+            prevptr = ptr;
+            ptr++;
+        } /* else */
+    } /* while */
+} /* zip_expand_symlink_path */
+
+/* (forward reference: zip_follow_symlink and zip_resolve call each other.) */
+static int zip_resolve(PHYSFS_Io *io, ZIPinfo *info, ZIPentry *entry);
+
+/*
+ * Look for the entry named by (path). If it exists, resolve it, and return
+ *  a pointer to that entry. If it's another symlink, keep resolving until you
+ *  hit a real file and then return a pointer to the final non-symlink entry.
+ *  If there's a problem, return NULL.
+ */
+static ZIPentry *zip_follow_symlink(PHYSFS_Io *io, ZIPinfo *info, char *path)
+{
+    ZIPentry *entry;
+
+    zip_expand_symlink_path(path);
+    entry = zip_find_entry(info, path, NULL);
+    if (entry != NULL)
+    {
+        if (!zip_resolve(io, info, entry))  /* recursive! */
+            entry = NULL;
+        else
+        {
+            if (entry->symlink != NULL)
+                entry = entry->symlink;
+        } /* else */
+    } /* if */
+
+    return entry;
+} /* zip_follow_symlink */
+
+
+static int zip_resolve_symlink(PHYSFS_Io *io, ZIPinfo *info, ZIPentry *entry)
+{
+    const PHYSFS_uint64 size = entry->uncompressed_size;
+    char *path = NULL;
+    int rc = 0;
+
+    /*
+     * We've already parsed the local file header of the symlink at this
+     *  point. Now we need to read the actual link from the file data and
+     *  follow it.
+     */
+
+    BAIL_IF_MACRO(!io->seek(io, entry->offset), ERRPASS, 0);
+
+    path = (char *) __PHYSFS_smallAlloc(size + 1);
+    BAIL_IF_MACRO(!path, PHYSFS_ERR_OUT_OF_MEMORY, 0);
+    
+    if (entry->compression_method == COMPMETH_NONE)
+        rc = __PHYSFS_readAll(io, path, size);
+
+    else  /* symlink target path is compressed... */
+    {
+        z_stream stream;
+        const PHYSFS_uint64 complen = entry->compressed_size;
+        PHYSFS_uint8 *compressed = (PHYSFS_uint8*) __PHYSFS_smallAlloc(complen);
+        if (compressed != NULL)
+        {
+            if (__PHYSFS_readAll(io, compressed, complen))
+            {
+                initializeZStream(&stream);
+                stream.next_in = compressed;
+                stream.avail_in = complen;
+                stream.next_out = (unsigned char *) path;
+                stream.avail_out = size;
+                if (zlib_err(inflateInit2(&stream, -MAX_WBITS)) == Z_OK)
+                {
+                    rc = zlib_err(inflate(&stream, Z_FINISH));
+                    inflateEnd(&stream);
+
+                    /* both are acceptable outcomes... */
+                    rc = ((rc == Z_OK) || (rc == Z_STREAM_END));
+                } /* if */
+            } /* if */
+            __PHYSFS_smallFree(compressed);
+        } /* if */
+    } /* else */
+
+    if (rc)
+    {
+        path[entry->uncompressed_size] = '\0';    /* null-terminate it. */
+        zip_convert_dos_path(entry, path);
+        entry->symlink = zip_follow_symlink(io, info, path);
+    } /* else */
+
+    __PHYSFS_smallFree(path);
+
+    return (entry->symlink != NULL);
+} /* zip_resolve_symlink */
+
+
+/*
+ * Parse the local file header of an entry, and update entry->offset.
+ */
+static int zip_parse_local(PHYSFS_Io *io, ZIPentry *entry)
+{
+    PHYSFS_uint32 ui32;
+    PHYSFS_uint16 ui16;
+    PHYSFS_uint16 fnamelen;
+    PHYSFS_uint16 extralen;
+
+    /*
+     * crc and (un)compressed_size are always zero if this is a "JAR"
+     *  archive created with Sun's Java tools, apparently. We only
+     *  consider this archive corrupted if those entries don't match and
+     *  aren't zero. That seems to work well.
+     * We also ignore a mismatch if the value is 0xFFFFFFFF here, since it's
+     *  possible that's a Zip64 thing.
+     */
+
+    BAIL_IF_MACRO(!io->seek(io, entry->offset), ERRPASS, 0);
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    BAIL_IF_MACRO(ui32 != ZIP_LOCAL_FILE_SIG, PHYSFS_ERR_CORRUPT, 0);
+    BAIL_IF_MACRO(!readui16(io, &ui16), ERRPASS, 0);
+    BAIL_IF_MACRO(ui16 != entry->version_needed, PHYSFS_ERR_CORRUPT, 0);
+    BAIL_IF_MACRO(!readui16(io, &ui16), ERRPASS, 0);  /* general bits. */
+    BAIL_IF_MACRO(!readui16(io, &ui16), ERRPASS, 0);
+    BAIL_IF_MACRO(ui16 != entry->compression_method, PHYSFS_ERR_CORRUPT, 0);
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);  /* date/time */
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    BAIL_IF_MACRO(ui32 && (ui32 != entry->crc), PHYSFS_ERR_CORRUPT, 0);
+
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    BAIL_IF_MACRO(ui32 && (ui32 != 0xFFFFFFFF) &&
+                  (ui32 != entry->compressed_size), PHYSFS_ERR_CORRUPT, 0);
+
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    BAIL_IF_MACRO(ui32 && (ui32 != 0xFFFFFFFF) &&
+                 (ui32 != entry->uncompressed_size), PHYSFS_ERR_CORRUPT, 0);
+
+    BAIL_IF_MACRO(!readui16(io, &fnamelen), ERRPASS, 0);
+    BAIL_IF_MACRO(!readui16(io, &extralen), ERRPASS, 0);
+
+    entry->offset += fnamelen + extralen + 30;
+    return 1;
+} /* zip_parse_local */
+
+
+static int zip_resolve(PHYSFS_Io *io, ZIPinfo *info, ZIPentry *entry)
+{
+    int retval = 1;
+    ZipResolveType resolve_type = entry->resolved;
+
+    /* Don't bother if we've failed to resolve this entry before. */
+    BAIL_IF_MACRO(resolve_type == ZIP_BROKEN_FILE, PHYSFS_ERR_CORRUPT, 0);
+    BAIL_IF_MACRO(resolve_type == ZIP_BROKEN_SYMLINK, PHYSFS_ERR_CORRUPT, 0);
+
+    /* uhoh...infinite symlink loop! */
+    BAIL_IF_MACRO(resolve_type == ZIP_RESOLVING, PHYSFS_ERR_SYMLINK_LOOP, 0);
+
+    /*
+     * We fix up the offset to point to the actual data on the
+     *  first open, since we don't want to seek across the whole file on
+     *  archive open (can be SLOW on large, CD-stored files), but we
+     *  need to check the local file header...not just for corruption,
+     *  but since it stores offset info the central directory does not.
+     */
+    if (resolve_type != ZIP_RESOLVED)
+    {
+        entry->resolved = ZIP_RESOLVING;
+
+        retval = zip_parse_local(io, entry);
+        if (retval)
+        {
+            /*
+             * If it's a symlink, find the original file. This will cause
+             *  resolution of other entries (other symlinks and, eventually,
+             *  the real file) if all goes well.
+             */
+            if (resolve_type == ZIP_UNRESOLVED_SYMLINK)
+                retval = zip_resolve_symlink(io, info, entry);
+        } /* if */
+
+        if (resolve_type == ZIP_UNRESOLVED_SYMLINK)
+            entry->resolved = ((retval) ? ZIP_RESOLVED : ZIP_BROKEN_SYMLINK);
+        else if (resolve_type == ZIP_UNRESOLVED_FILE)
+            entry->resolved = ((retval) ? ZIP_RESOLVED : ZIP_BROKEN_FILE);
+    } /* if */
+
+    return retval;
+} /* zip_resolve */
+
+
+static int zip_version_does_symlinks(PHYSFS_uint32 version)
+{
+    int retval = 0;
+    PHYSFS_uint8 hosttype = (PHYSFS_uint8) ((version >> 8) & 0xFF);
+
+    switch (hosttype)
+    {
+            /*
+             * These are the platforms that can NOT build an archive with
+             *  symlinks, according to the Info-ZIP project.
+             */
+        case 0:  /* FS_FAT_  */
+        case 1:  /* AMIGA_   */
+        case 2:  /* VMS_     */
+        case 4:  /* VM_CSM_  */
+        case 6:  /* FS_HPFS_ */
+        case 11: /* FS_NTFS_ */
+        case 14: /* FS_VFAT_ */
+        case 13: /* ACORN_   */
+        case 15: /* MVS_     */
+        case 18: /* THEOS_   */
+            break;  /* do nothing. */
+
+        default:  /* assume the rest to be unix-like. */
+            retval = 1;
+            break;
+    } /* switch */
+
+    return retval;
+} /* zip_version_does_symlinks */
+
+
+static int zip_entry_is_symlink(const ZIPentry *entry)
+{
+    return ((entry->resolved == ZIP_UNRESOLVED_SYMLINK) ||
+            (entry->resolved == ZIP_BROKEN_SYMLINK) ||
+            (entry->symlink));
+} /* zip_entry_is_symlink */
+
+
+static int zip_has_symlink_attr(ZIPentry *entry, PHYSFS_uint32 extern_attr)
+{
+    PHYSFS_uint16 xattr = ((extern_attr >> 16) & 0xFFFF);
+    return ( (zip_version_does_symlinks(entry->version)) &&
+             (entry->uncompressed_size > 0) &&
+             ((xattr & UNIX_FILETYPE_MASK) == UNIX_FILETYPE_SYMLINK) );
+} /* zip_has_symlink_attr */
+
+
+static PHYSFS_sint64 zip_dos_time_to_physfs_time(PHYSFS_uint32 dostime)
+{
+    PHYSFS_uint32 dosdate;
+    struct tm unixtime;
+    memset(&unixtime, '\0', sizeof (unixtime));
+
+    dosdate = (PHYSFS_uint32) ((dostime >> 16) & 0xFFFF);
+    dostime &= 0xFFFF;
+
+    /* dissect date */
+    unixtime.tm_year = ((dosdate >> 9) & 0x7F) + 80;
+    unixtime.tm_mon  = ((dosdate >> 5) & 0x0F) - 1;
+    unixtime.tm_mday = ((dosdate     ) & 0x1F);
+
+    /* dissect time */
+    unixtime.tm_hour = ((dostime >> 11) & 0x1F);
+    unixtime.tm_min  = ((dostime >>  5) & 0x3F);
+    unixtime.tm_sec  = ((dostime <<  1) & 0x3E);
+
+    /* let mktime calculate daylight savings time. */
+    unixtime.tm_isdst = -1;
+
+    return ((PHYSFS_sint64) mktime(&unixtime));
+} /* zip_dos_time_to_physfs_time */
+
+
+static int zip_load_entry(PHYSFS_Io *io, const int zip64, ZIPentry *entry,
+                          PHYSFS_uint64 ofs_fixup)
+{
+    PHYSFS_uint16 fnamelen, extralen, commentlen;
+    PHYSFS_uint32 external_attr;
+    PHYSFS_uint32 starting_disk;
+    PHYSFS_uint64 offset;
+    PHYSFS_uint16 ui16;
+    PHYSFS_uint32 ui32;
+    PHYSFS_sint64 si64;
+
+    /* sanity check with central directory signature... */
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    BAIL_IF_MACRO(ui32 != ZIP_CENTRAL_DIR_SIG, PHYSFS_ERR_CORRUPT, 0);
+
+    /* Get the pertinent parts of the record... */
+    BAIL_IF_MACRO(!readui16(io, &entry->version), ERRPASS, 0);
+    BAIL_IF_MACRO(!readui16(io, &entry->version_needed), ERRPASS, 0);
+    BAIL_IF_MACRO(!readui16(io, &ui16), ERRPASS, 0);  /* general bits */
+    BAIL_IF_MACRO(!readui16(io, &entry->compression_method), ERRPASS, 0);
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    entry->last_mod_time = zip_dos_time_to_physfs_time(ui32);
+    BAIL_IF_MACRO(!readui32(io, &entry->crc), ERRPASS, 0);
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    entry->compressed_size = (PHYSFS_uint64) ui32;
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    entry->uncompressed_size = (PHYSFS_uint64) ui32;
+    BAIL_IF_MACRO(!readui16(io, &fnamelen), ERRPASS, 0);
+    BAIL_IF_MACRO(!readui16(io, &extralen), ERRPASS, 0);
+    BAIL_IF_MACRO(!readui16(io, &commentlen), ERRPASS, 0);
+    BAIL_IF_MACRO(!readui16(io, &ui16), ERRPASS, 0);
+    starting_disk = (PHYSFS_uint32) ui16;
+    BAIL_IF_MACRO(!readui16(io, &ui16), ERRPASS, 0);  /* internal file attribs */
+    BAIL_IF_MACRO(!readui32(io, &external_attr), ERRPASS, 0);
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    offset = (PHYSFS_uint64) ui32;
+
+    entry->symlink = NULL;  /* will be resolved later, if necessary. */
+    entry->resolved = (zip_has_symlink_attr(entry, external_attr)) ?
+                            ZIP_UNRESOLVED_SYMLINK : ZIP_UNRESOLVED_FILE;
+
+    entry->name = (char *) allocator.Malloc(fnamelen + 1);
+    BAIL_IF_MACRO(entry->name == NULL, PHYSFS_ERR_OUT_OF_MEMORY, 0);
+    if (!__PHYSFS_readAll(io, entry->name, fnamelen))
+        goto zip_load_entry_puked;
+
+    entry->name[fnamelen] = '\0';  /* null-terminate the filename. */
+    zip_convert_dos_path(entry, entry->name);
+
+    si64 = io->tell(io);
+    if (si64 == -1)
+        goto zip_load_entry_puked;
+
+    /*
+     * The actual sizes didn't fit in 32-bits; look for the Zip64
+     *  extended information extra field...
+     */
+    if ( (zip64) &&
+         ((offset == 0xFFFFFFFF) ||
+          (starting_disk == 0xFFFFFFFF) ||
+          (entry->compressed_size == 0xFFFFFFFF) ||
+          (entry->uncompressed_size == 0xFFFFFFFF)) )
+    {
+        int found = 0;
+        PHYSFS_uint16 sig, len;
+        while (extralen > 4)
+        {
+            if (!readui16(io, &sig))
+                goto zip_load_entry_puked;
+            else if (!readui16(io, &len))
+                goto zip_load_entry_puked;
+
+            si64 += 4 + len;
+            extralen -= 4 + len;
+            if (sig != ZIP64_EXTENDED_INFO_EXTRA_FIELD_SIG)
+            {
+                if (!io->seek(io, si64))
+                    goto zip_load_entry_puked;
+                continue;
+            } /* if */
+
+            found = 1;
+            break;
+        } /* while */
+
+        GOTO_IF_MACRO(!found, PHYSFS_ERR_CORRUPT, zip_load_entry_puked);
+
+        if (entry->uncompressed_size == 0xFFFFFFFF)
+        {
+            GOTO_IF_MACRO(len < 8, PHYSFS_ERR_CORRUPT, zip_load_entry_puked);
+            if (!readui64(io, &entry->uncompressed_size))
+                goto zip_load_entry_puked;
+            len -= 8;
+        } /* if */
+
+        if (entry->compressed_size == 0xFFFFFFFF)
+        {
+            GOTO_IF_MACRO(len < 8, PHYSFS_ERR_CORRUPT, zip_load_entry_puked);
+            if (!readui64(io, &entry->compressed_size))
+                goto zip_load_entry_puked;
+            len -= 8;
+        } /* if */
+
+        if (offset == 0xFFFFFFFF)
+        {
+            GOTO_IF_MACRO(len < 8, PHYSFS_ERR_CORRUPT, zip_load_entry_puked);
+            if (!readui64(io, &offset))
+                goto zip_load_entry_puked;
+            len -= 8;
+        } /* if */
+
+        if (starting_disk == 0xFFFFFFFF)
+        {
+            GOTO_IF_MACRO(len < 8, PHYSFS_ERR_CORRUPT, zip_load_entry_puked);
+            if (!readui32(io, &starting_disk))
+                goto zip_load_entry_puked;
+            len -= 4;
+        } /* if */
+
+        GOTO_IF_MACRO(len != 0, PHYSFS_ERR_CORRUPT, zip_load_entry_puked);
+    } /* if */
+
+    GOTO_IF_MACRO(starting_disk != 0, PHYSFS_ERR_CORRUPT, zip_load_entry_puked);
+
+    entry->offset = offset + ofs_fixup;
+
+    /* seek to the start of the next entry in the central directory... */
+    if (!io->seek(io, si64 + extralen + commentlen))
+        goto zip_load_entry_puked;
+
+    return 1;  /* success. */
+
+zip_load_entry_puked:
+    allocator.Free(entry->name);
+    return 0;  /* failure. */
+} /* zip_load_entry */
+
+
+static int zip_entry_cmp(void *_a, size_t one, size_t two)
+{
+    if (one != two)
+    {
+        const ZIPentry *a = (const ZIPentry *) _a;
+        return strcmp(a[one].name, a[two].name);
+    } /* if */
+
+    return 0;
+} /* zip_entry_cmp */
+
+
+static void zip_entry_swap(void *_a, size_t one, size_t two)
+{
+    if (one != two)
+    {
+        ZIPentry tmp;
+        ZIPentry *first = &(((ZIPentry *) _a)[one]);
+        ZIPentry *second = &(((ZIPentry *) _a)[two]);
+        memcpy(&tmp, first, sizeof (ZIPentry));
+        memcpy(first, second, sizeof (ZIPentry));
+        memcpy(second, &tmp, sizeof (ZIPentry));
+    } /* if */
+} /* zip_entry_swap */
+
+
+static int zip_load_entries(PHYSFS_Io *io, ZIPinfo *info,
+                            const PHYSFS_uint64 data_ofs,
+                            const PHYSFS_uint64 central_ofs)
+{
+    const PHYSFS_uint64 max = info->entryCount;
+    const int zip64 = info->zip64;
+    PHYSFS_uint64 i;
+
+    BAIL_IF_MACRO(!io->seek(io, central_ofs), ERRPASS, 0);
+
+    info->entries = (ZIPentry *) allocator.Malloc(sizeof (ZIPentry) * max);
+    BAIL_IF_MACRO(!info->entries, PHYSFS_ERR_OUT_OF_MEMORY, 0);
+
+    for (i = 0; i < max; i++)
+    {
+        if (!zip_load_entry(io, zip64, &info->entries[i], data_ofs))
+        {
+            zip_free_entries(info->entries, i);
+            return 0;
+        } /* if */
+    } /* for */
+
+    __PHYSFS_sort(info->entries, (size_t) max, zip_entry_cmp, zip_entry_swap);
+    return 1;
+} /* zip_load_entries */
+
+
+static PHYSFS_sint64 zip64_find_end_of_central_dir(PHYSFS_Io *io,
+                                                   PHYSFS_sint64 _pos,
+                                                   PHYSFS_uint64 offset)
+{
+    /*
+     * Naturally, the offset is useless to us; it is the offset from the
+     *  start of file, which is meaningless if we've appended this .zip to
+     *  a self-extracting .exe. We need to find this on our own. It should
+     *  be directly before the locator record, but the record in question,
+     *  like the original end-of-central-directory record, ends with a
+     *  variable-length field. Unlike the original, which has to store the
+     *  size of that variable-length field in a 16-bit int and thus has to be
+     *  within 64k, the new one gets 64-bits.
+     *
+     * Fortunately, the only currently-specified record for that variable
+     *  length block is some weird proprietary thing that deals with EBCDIC
+     *  and tape backups or something. So we don't seek far.
+     */
+
+    PHYSFS_uint32 ui32;
+    const PHYSFS_uint64 pos = (PHYSFS_uint64) _pos;
+
+    assert(_pos > 0);
+
+    /* Try offset specified in the Zip64 end of central directory locator. */
+    /* This works if the entire PHYSFS_Io is the zip file. */
+    BAIL_IF_MACRO(!io->seek(io, offset), ERRPASS, -1);
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, -1);
+    if (ui32 == ZIP64_END_OF_CENTRAL_DIR_SIG)
+        return offset;
+
+    /* Try 56 bytes before the Zip64 end of central directory locator. */
+    /* This works if the record isn't variable length and is version 1. */
+    if (pos > 56)
+    {
+        BAIL_IF_MACRO(!io->seek(io, pos-56), ERRPASS, -1);
+        BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, -1);
+        if (ui32 == ZIP64_END_OF_CENTRAL_DIR_SIG)
+            return pos-56;
+    } /* if */
+
+    /* Try 84 bytes before the Zip64 end of central directory locator. */
+    /* This works if the record isn't variable length and is version 2. */
+    if (pos > 84)
+    {
+        BAIL_IF_MACRO(!io->seek(io, pos-84), ERRPASS, -1);
+        BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, -1);
+        if (ui32 == ZIP64_END_OF_CENTRAL_DIR_SIG)
+            return pos-84;
+    } /* if */
+
+    /* Ok, brute force: we know it's between (offset) and (pos) somewhere. */
+    /*  Just try moving back at most 256k. Oh well. */
+    if ((offset < pos) && (pos > 4))
+    {
+        /* we assume you can eat this stack if you handle Zip64 files. */
+        PHYSFS_uint8 buf[256 * 1024];
+        PHYSFS_uint64 len = pos - offset;
+        PHYSFS_sint32 i;
+
+        if (len > sizeof (buf))
+            len = sizeof (buf);
+
+        BAIL_IF_MACRO(!io->seek(io, pos - len), ERRPASS, -1);
+        BAIL_IF_MACRO(!__PHYSFS_readAll(io, buf, len), ERRPASS, -1);
+        for (i = (PHYSFS_sint32) (len - 4); i >= 0; i--)
+        {
+            if (buf[i] != 0x50)
+                continue;
+            if ( (buf[i+1] == 0x4b) &&
+                 (buf[i+2] == 0x06) &&
+                 (buf[i+3] == 0x06) )
+                return pos - (len - i);
+        } /* for */
+    } /* if */
+
+    BAIL_MACRO(PHYSFS_ERR_CORRUPT, -1);  /* didn't find it. */
+} /* zip64_find_end_of_central_dir */
+
+
+static int zip64_parse_end_of_central_dir(PHYSFS_Io *io, ZIPinfo *info,
+                                          PHYSFS_uint64 *data_start,
+                                          PHYSFS_uint64 *dir_ofs,
+                                          PHYSFS_sint64 pos)
+{
+    PHYSFS_uint64 ui64;
+    PHYSFS_uint32 ui32;
+    PHYSFS_uint16 ui16;
+
+    /* We should be positioned right past the locator signature. */
+
+    if ((pos < 0) || (!io->seek(io, pos)))
+        return 0;
+
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    if (ui32 != ZIP64_END_OF_CENTRAL_DIRECTORY_LOCATOR_SIG)
+        return -1;  /* it's not a Zip64 archive. Not an error, though! */
+
+    info->zip64 = 1;
+
+    /* number of the disk with the start of the central directory. */
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    BAIL_IF_MACRO(ui32 != 0, PHYSFS_ERR_CORRUPT, 0);
+
+    /* offset of Zip64 end of central directory record. */
+    BAIL_IF_MACRO(!readui64(io, &ui64), ERRPASS, 0);
+
+    /* total number of disks */
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    BAIL_IF_MACRO(ui32 != 1, PHYSFS_ERR_CORRUPT, 0);
+
+    pos = zip64_find_end_of_central_dir(io, pos, ui64);
+    if (pos < 0)
+        return 0;  /* oh well. */
+
+    /*
+     * For self-extracting archives, etc, there's crapola in the file
+     *  before the zipfile records; we calculate how much data there is
+     *  prepended by determining how far the zip64-end-of-central-directory
+     *  offset is from where it is supposed to be...the difference in bytes
+     *  is how much arbitrary data is at the start of the physical file.
+     */
+    assert(((PHYSFS_uint64) pos) >= ui64);
+    *data_start = ((PHYSFS_uint64) pos) - ui64;
+
+    BAIL_IF_MACRO(!io->seek(io, pos), ERRPASS, 0);
+
+    /* check signature again, just in case. */
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    BAIL_IF_MACRO(ui32 != ZIP64_END_OF_CENTRAL_DIR_SIG, PHYSFS_ERR_CORRUPT, 0);
+
+    /* size of Zip64 end of central directory record. */
+    BAIL_IF_MACRO(!readui64(io, &ui64), ERRPASS, 0);
+
+    /* version made by. */
+    BAIL_IF_MACRO(!readui16(io, &ui16), ERRPASS, 0);
+
+    /* version needed to extract. */
+    BAIL_IF_MACRO(!readui16(io, &ui16), ERRPASS, 0);
+
+    /* number of this disk. */
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    BAIL_IF_MACRO(ui32 != 0, PHYSFS_ERR_CORRUPT, 0);
+
+    /* number of disk with start of central directory record. */
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    BAIL_IF_MACRO(ui32 != 0, PHYSFS_ERR_CORRUPT, 0);
+
+    /* total number of entries in the central dir on this disk */
+    BAIL_IF_MACRO(!readui64(io, &ui64), ERRPASS, 0);
+
+    /* total number of entries in the central dir */
+    BAIL_IF_MACRO(!readui64(io, &info->entryCount), ERRPASS, 0);
+    BAIL_IF_MACRO(ui64 != info->entryCount, PHYSFS_ERR_CORRUPT, 0);
+
+    /* size of the central directory */
+    BAIL_IF_MACRO(!readui64(io, &ui64), ERRPASS, 0);
+
+    /* offset of central directory */
+    BAIL_IF_MACRO(!readui64(io, dir_ofs), ERRPASS, 0);
+
+    /* Since we know the difference, fix up the central dir offset... */
+    *dir_ofs += *data_start;
+
+    /*
+     * There are more fields here, for encryption and feature-specific things,
+     *  but we don't care about any of them at the moment.
+     */
+
+    return 1;  /* made it. */
+} /* zip64_parse_end_of_central_dir */
+
+
+static int zip_parse_end_of_central_dir(PHYSFS_Io *io, ZIPinfo *info,
+                                        PHYSFS_uint64 *data_start,
+                                        PHYSFS_uint64 *dir_ofs)
+{
+    PHYSFS_uint16 entryCount16;
+    PHYSFS_uint32 offset32;
+    PHYSFS_uint32 ui32;
+    PHYSFS_uint16 ui16;
+    PHYSFS_sint64 len;
+    PHYSFS_sint64 pos;
+    int rc;
+
+    /* find the end-of-central-dir record, and seek to it. */
+    pos = zip_find_end_of_central_dir(io, &len);
+    BAIL_IF_MACRO(pos == -1, ERRPASS, 0);
+    BAIL_IF_MACRO(!io->seek(io, pos), ERRPASS, 0);
+
+    /* check signature again, just in case. */
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+    BAIL_IF_MACRO(ui32 != ZIP_END_OF_CENTRAL_DIR_SIG, PHYSFS_ERR_CORRUPT, 0);
+
+    /* Seek back to see if "Zip64 end of central directory locator" exists. */
+    /* this record is 20 bytes before end-of-central-dir */
+    rc = zip64_parse_end_of_central_dir(io, info, data_start, dir_ofs, pos-20);
+    BAIL_IF_MACRO(rc == 0, ERRPASS, 0);
+    if (rc == 1)
+        return 1;  /* we're done here. */
+
+    assert(rc == -1);  /* no error, just not a Zip64 archive. */
+
+    /* Not Zip64? Seek back to where we were and keep processing. */
+    BAIL_IF_MACRO(!io->seek(io, pos + 4), ERRPASS, 0);
+
+    /* number of this disk */
+    BAIL_IF_MACRO(!readui16(io, &ui16), ERRPASS, 0);
+    BAIL_IF_MACRO(ui16 != 0, PHYSFS_ERR_CORRUPT, 0);
+
+    /* number of the disk with the start of the central directory */
+    BAIL_IF_MACRO(!readui16(io, &ui16), ERRPASS, 0);
+    BAIL_IF_MACRO(ui16 != 0, PHYSFS_ERR_CORRUPT, 0);
+
+    /* total number of entries in the central dir on this disk */
+    BAIL_IF_MACRO(!readui16(io, &ui16), ERRPASS, 0);
+
+    /* total number of entries in the central dir */
+    BAIL_IF_MACRO(!readui16(io, &entryCount16), ERRPASS, 0);
+    BAIL_IF_MACRO(ui16 != entryCount16, PHYSFS_ERR_CORRUPT, 0);
+
+    info->entryCount = entryCount16;
+
+    /* size of the central directory */
+    BAIL_IF_MACRO(!readui32(io, &ui32), ERRPASS, 0);
+
+    /* offset of central directory */
+    BAIL_IF_MACRO(!readui32(io, &offset32), ERRPASS, 0);
+    *dir_ofs = (PHYSFS_uint64) offset32;
+    BAIL_IF_MACRO(pos < (*dir_ofs + ui32), PHYSFS_ERR_CORRUPT, 0);
+
+    /*
+     * For self-extracting archives, etc, there's crapola in the file
+     *  before the zipfile records; we calculate how much data there is
+     *  prepended by determining how far the central directory offset is
+     *  from where it is supposed to be (start of end-of-central-dir minus
+     *  sizeof central dir)...the difference in bytes is how much arbitrary
+     *  data is at the start of the physical file.
+     */
+    *data_start = (PHYSFS_uint64) (pos - (*dir_ofs + ui32));
+
+    /* Now that we know the difference, fix up the central dir offset... */
+    *dir_ofs += *data_start;
+
+    /* zipfile comment length */
+    BAIL_IF_MACRO(!readui16(io, &ui16), ERRPASS, 0);
+
+    /*
+     * Make sure that the comment length matches to the end of file...
+     *  If it doesn't, we're either in the wrong part of the file, or the
+     *  file is corrupted, but we give up either way.
+     */
+    BAIL_IF_MACRO((pos + 22 + ui16) != len, PHYSFS_ERR_CORRUPT, 0);
+
+    return 1;  /* made it. */
+} /* zip_parse_end_of_central_dir */
+
+
+static void *ZIP_openArchive(PHYSFS_Io *io, const char *name, int forWriting)
+{
+    ZIPinfo *info = NULL;
+    PHYSFS_uint64 data_start;
+    PHYSFS_uint64 cent_dir_ofs;
+
+    assert(io != NULL);  /* shouldn't ever happen. */
+
+    BAIL_IF_MACRO(forWriting, PHYSFS_ERR_READ_ONLY, NULL);
+    BAIL_IF_MACRO(!isZip(io), ERRPASS, NULL);
+
+    info = (ZIPinfo *) allocator.Malloc(sizeof (ZIPinfo));
+    BAIL_IF_MACRO(!info, PHYSFS_ERR_OUT_OF_MEMORY, NULL);
+    memset(info, '\0', sizeof (ZIPinfo));
+    info->io = io;
+
+    if (!zip_parse_end_of_central_dir(io, info, &data_start, &cent_dir_ofs))
+        goto ZIP_openarchive_failed;
+
+    if (!zip_load_entries(io, info, data_start, cent_dir_ofs))
+        goto ZIP_openarchive_failed;
+
+    return info;
+
+ZIP_openarchive_failed:
+    if (info != NULL)
+        allocator.Free(info);
+
+    return NULL;
+} /* ZIP_openArchive */
+
+
+static PHYSFS_sint64 zip_find_start_of_dir(ZIPinfo *info, const char *path,
+                                            int stop_on_first_find)
+{
+    PHYSFS_sint64 lo = 0;
+    PHYSFS_sint64 hi = (PHYSFS_sint64) (info->entryCount - 1);
+    PHYSFS_sint64 middle;
+    PHYSFS_uint32 dlen = (PHYSFS_uint32) strlen(path);
+    PHYSFS_sint64 retval = -1;
+    const char *name;
+    int rc;
+
+    if (*path == '\0')  /* root dir? */
+        return 0;
+
+    if ((dlen > 0) && (path[dlen - 1] == '/')) /* ignore trailing slash. */
+        dlen--;
+
+    while (lo <= hi)
+    {
+        middle = lo + ((hi - lo) / 2);
+        name = info->entries[middle].name;
+        rc = strncmp(path, name, dlen);
+        if (rc == 0)
+        {
+            char ch = name[dlen];
+            if ('/' < ch) /* make sure this isn't just a substr match. */
+                rc = -1;
+            else if ('/' > ch)
+                rc = 1;
+            else 
+            {
+                if (stop_on_first_find) /* Just checking dir's existance? */
+                    return middle;
+
+                if (name[dlen + 1] == '\0') /* Skip initial dir entry. */
+                    return (middle + 1);
+
+                /* there might be more entries earlier in the list. */
+                retval = middle;
+                hi = middle - 1;
+            } /* else */
+        } /* if */
+
+        if (rc > 0)
+            lo = middle + 1;
+        else
+            hi = middle - 1;
+    } /* while */
+
+    return retval;
+} /* zip_find_start_of_dir */
+
+
+/*
+ * Moved to seperate function so we can use alloca then immediately throw
+ *  away the allocated stack space...
+ */
+static void doEnumCallback(PHYSFS_EnumFilesCallback cb, void *callbackdata,
+                           const char *odir, const char *str, PHYSFS_sint32 ln)
+{
+    char *newstr = __PHYSFS_smallAlloc(ln + 1);
+    if (newstr == NULL)
+        return;
+
+    memcpy(newstr, str, ln);
+    newstr[ln] = '\0';
+    cb(callbackdata, odir, newstr);
+    __PHYSFS_smallFree(newstr);
+} /* doEnumCallback */
+
+
+static void ZIP_enumerateFiles(PHYSFS_Dir *opaque, const char *dname,
+                               int omitSymLinks, PHYSFS_EnumFilesCallback cb,
+                               const char *origdir, void *callbackdata)
+{
+    ZIPinfo *info = ((ZIPinfo *) opaque);
+    PHYSFS_sint32 dlen, dlen_inc;
+    PHYSFS_sint64 i, max;
+
+    i = zip_find_start_of_dir(info, dname, 0);
+    if (i == -1)  /* no such directory. */
+        return;
+
+    dlen = (PHYSFS_sint32) strlen(dname);
+    if ((dlen > 0) && (dname[dlen - 1] == '/')) /* ignore trailing slash. */
+        dlen--;
+
+    dlen_inc = ((dlen > 0) ? 1 : 0) + dlen;
+    max = (PHYSFS_sint64) info->entryCount;
+    while (i < max)
+    {
+        char *e = info->entries[i].name;
+        if ((dlen) && ((strncmp(e, dname, dlen) != 0) || (e[dlen] != '/')))
+            break;  /* past end of this dir; we're done. */
+
+        if ((omitSymLinks) && (zip_entry_is_symlink(&info->entries[i])))
+            i++;
+        else
+        {
+            char *add = e + dlen_inc;
+            char *ptr = strchr(add, '/');
+            PHYSFS_sint32 ln = (PHYSFS_sint32) ((ptr) ? ptr-add : strlen(add));
+            doEnumCallback(cb, callbackdata, origdir, add, ln);
+            ln += dlen_inc;  /* point past entry to children... */
+
+            /* increment counter and skip children of subdirs... */
+            while ((++i < max) && (ptr != NULL))
+            {
+                char *e_new = info->entries[i].name;
+                if ((strncmp(e, e_new, ln) != 0) || (e_new[ln] != '/'))
+                    break;
+            } /* while */
+        } /* else */
+    } /* while */
+} /* ZIP_enumerateFiles */
+
+
+static PHYSFS_Io *zip_get_io(PHYSFS_Io *io, ZIPinfo *inf, ZIPentry *entry)
+{
+    int success;
+    PHYSFS_Io *retval = io->duplicate(io);
+    BAIL_IF_MACRO(!retval, ERRPASS, NULL);
+
+    /* !!! FIXME: if you open a dir here, it should bail ERR_NOT_A_FILE */
+
+    /* (inf) can be NULL if we already resolved. */
+    success = (inf == NULL) || zip_resolve(retval, inf, entry);
+    if (success)
+    {
+        PHYSFS_sint64 offset;
+        offset = ((entry->symlink) ? entry->symlink->offset : entry->offset);
+        success = retval->seek(retval, offset);
+    } /* if */
+
+    if (!success)
+    {
+        retval->destroy(retval);
+        retval = NULL;
+    } /* if */
+
+    return retval;
+} /* zip_get_io */
+
+
+static PHYSFS_Io *ZIP_openRead(PHYSFS_Dir *opaque, const char *fnm,
+                               int *fileExists)
+{
+    PHYSFS_Io *retval = NULL;
+    ZIPinfo *info = (ZIPinfo *) opaque;
+    ZIPentry *entry = zip_find_entry(info, fnm, NULL);
+    ZIPfileinfo *finfo = NULL;
+
+    *fileExists = (entry != NULL);
+    BAIL_IF_MACRO(!entry, ERRPASS, NULL);
+
+    retval = (PHYSFS_Io *) allocator.Malloc(sizeof (PHYSFS_Io));
+    GOTO_IF_MACRO(!retval, PHYSFS_ERR_OUT_OF_MEMORY, ZIP_openRead_failed);
+
+    finfo = (ZIPfileinfo *) allocator.Malloc(sizeof (ZIPfileinfo));
+    GOTO_IF_MACRO(!finfo, PHYSFS_ERR_OUT_OF_MEMORY, ZIP_openRead_failed);
+    memset(finfo, '\0', sizeof (ZIPfileinfo));
+
+    finfo->io = zip_get_io(info->io, info, entry);
+    GOTO_IF_MACRO(!finfo->io, ERRPASS, ZIP_openRead_failed);
+    finfo->entry = ((entry->symlink != NULL) ? entry->symlink : entry);
+    initializeZStream(&finfo->stream);
+
+    if (finfo->entry->compression_method != COMPMETH_NONE)
+    {
+        finfo->buffer = (PHYSFS_uint8 *) allocator.Malloc(ZIP_READBUFSIZE);
+        if (!finfo->buffer)
+            GOTO_MACRO(PHYSFS_ERR_OUT_OF_MEMORY, ZIP_openRead_failed);
+        else if (zlib_err(inflateInit2(&finfo->stream, -MAX_WBITS)) != Z_OK)
+            goto ZIP_openRead_failed;
+    } /* if */
+
+    memcpy(retval, &ZIP_Io, sizeof (PHYSFS_Io));
+    retval->opaque = finfo;
+
+    return retval;
+
+ZIP_openRead_failed:
+    if (finfo != NULL)
+    {
+        if (finfo->io != NULL)
+            finfo->io->destroy(finfo->io);
+
+        if (finfo->buffer != NULL)
+        {
+            allocator.Free(finfo->buffer);
+            inflateEnd(&finfo->stream);
+        } /* if */
+
+        allocator.Free(finfo);
+    } /* if */
+
+    if (retval != NULL)
+        allocator.Free(retval);
+
+    return NULL;
+} /* ZIP_openRead */
+
+
+static PHYSFS_Io *ZIP_openWrite(PHYSFS_Dir *opaque, const char *filename)
+{
+    BAIL_MACRO(PHYSFS_ERR_READ_ONLY, NULL);
+} /* ZIP_openWrite */
+
+
+static PHYSFS_Io *ZIP_openAppend(PHYSFS_Dir *opaque, const char *filename)
+{
+    BAIL_MACRO(PHYSFS_ERR_READ_ONLY, NULL);
+} /* ZIP_openAppend */
+
+
+static void ZIP_closeArchive(PHYSFS_Dir *opaque)
+{
+    ZIPinfo *zi = (ZIPinfo *) (opaque);
+    zi->io->destroy(zi->io);
+    zip_free_entries(zi->entries, zi->entryCount);
+    allocator.Free(zi);
+} /* ZIP_closeArchive */
+
+
+static int ZIP_remove(PHYSFS_Dir *opaque, const char *name)
+{
+    BAIL_MACRO(PHYSFS_ERR_READ_ONLY, 0);
+} /* ZIP_remove */
+
+
+static int ZIP_mkdir(PHYSFS_Dir *opaque, const char *name)
+{
+    BAIL_MACRO(PHYSFS_ERR_READ_ONLY, 0);
+} /* ZIP_mkdir */
+
+
+static int ZIP_stat(PHYSFS_Dir *opaque, const char *filename, int *exists,
+                    PHYSFS_Stat *stat)
+{
+    int isDir = 0;
+    const ZIPinfo *info = (const ZIPinfo *) opaque;
+    const ZIPentry *entry = zip_find_entry(info, filename, &isDir);
+
+    /* !!! FIXME: does this need to resolve entries here? */
+
+    *exists = isDir || (entry != 0);
+    if (!*exists)
+        return 0;
+
+    if (isDir)
+    {
+        stat->filesize = 0;
+        stat->filetype = PHYSFS_FILETYPE_DIRECTORY;
+    } /* if */
+
+    else if (zip_entry_is_symlink(entry))
+    {
+        stat->filesize = 0;
+        stat->filetype = PHYSFS_FILETYPE_SYMLINK;
+    } /* else if */
+
+    else
+    {
+        stat->filesize = (PHYSFS_sint64) entry->uncompressed_size;
+        stat->filetype = PHYSFS_FILETYPE_REGULAR;
+    } /* else */
+
+    stat->modtime = ((entry) ? entry->last_mod_time : 0);
+    stat->createtime = stat->modtime;
+    stat->accesstime = 0;
+    stat->readonly = 1; /* .zip files are always read only */
+
+    return 1;
+} /* ZIP_stat */
+
+
+const PHYSFS_Archiver __PHYSFS_Archiver_ZIP =
+{
+    {
+        "ZIP",
+        "PkZip/WinZip/Info-Zip compatible",
+        "Ryan C. Gordon <icculus@icculus.org>",
+        "http://icculus.org/physfs/",
+    },
+    ZIP_openArchive,        /* openArchive() method    */
+    ZIP_enumerateFiles,     /* enumerateFiles() method */
+    ZIP_openRead,           /* openRead() method       */
+    ZIP_openWrite,          /* openWrite() method      */
+    ZIP_openAppend,         /* openAppend() method     */
+    ZIP_remove,             /* remove() method         */
+    ZIP_mkdir,              /* mkdir() method          */
+    ZIP_closeArchive,       /* closeArchive() method   */
+    ZIP_stat                /* stat() method           */
+};
+
+#endif  /* defined PHYSFS_SUPPORTS_ZIP */
+
+/* end of zip.c ... */
+