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zipio.c
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/*
* zipio.c - stdio emulation library for reading zip files
*
* Version 1.1.2
*/
/*
* Copyright (C) 1995, Edward B. Hamrick
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby granted,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear in
* supporting documentation, and that the name of the copyright holders
* not be used in advertising or publicity pertaining to distribution of
* the software without specific, written prior permission. The copyright
* holders makes no representations about the suitability of this software
* for any purpose. It is provided "as is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
* IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT
* OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
* USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
/*
* Changes from 1.1 to 1.1.1:
* Changed "z*" functions to "Z*" to avoid namespace pollution.
* Added "zungetc" macro.
* Added definitions of SEEK_SET, SEEK_CUR, SEEK_END for the Posixly challenged
* John Cowan <cowan@ccil.org>
*
* Changes from 1.1.1 to 1.1.2:
* Relicensed under the MIT license, with consent of the copyright holders.
* Avoid usage of unitialized "length" variable in _Zgetc
* Claudio Matsuoka (Jan 11 2011)
*/
/*
* Refer to zipio.h for a description of this package.
*/
/*
* The .zip file header is described below. It consists of
* 30 fixed bytes, followed by two variable length fields
* whose length is contained in the first 30 bytes. After this
* header, the data is stored (in deflate format if the compression
* method is 8).
*
* The crc-32 field is the crc on the uncompressed data.
*
* .zip file header:
*
* local file header signature 4 bytes (0x04034b50)
* version needed to extract 2 bytes
* general purpose bit flag 2 bytes
* compression method 2 bytes
* last mod file time 2 bytes
* last mod file date 2 bytes
* crc-32 4 bytes
* compressed size 4 bytes
* uncompressed size 4 bytes
* filename length 2 bytes
* extra field length 2 bytes
*
* filename (variable size)
* extra field (variable size)
*
* These fields are described in more detail in appnote.txt
* in the pkzip 1.93 distribution.
*/
#include <stdlib.h>
#ifdef MEMCPY
#include <mem.h>
#endif
#include "zipio.h"
#include "inflate.h"
#include "crc.h"
/*
* Macros for constants
*/
#ifndef NULL
#define NULL ((void *) 0)
#endif
#ifndef TRUE
#define TRUE 1
#endif
#ifndef FALSE
#define FALSE 0
#endif
#ifndef ZIPSIGNATURE
#define ZIPSIGNATURE 0x04034b50L
#endif
#ifndef SEEK_SET
#define SEEK_SET 0
#endif
#ifndef SEEK_CUR
#define SEEK_CUR 1
#endif
#ifndef SEEK_END
#define SEEK_END 2
#endif
/*
* Buffer size macros
*
* The following constants are optimized for large-model
* (but not flat model) Windows with virtual memory. It
* will work fine on unix and flat model Windows as well.
*
* The constant BUFFERTHRESHOLD determines when memory
* buffering changes to file buffering.
*
* Assumptions:
*
* 1) INPBUFSIZE + OUTBUFSIZE + sizeof(void *) * PTRBUFSIZE + delta < 64K
*
* 2) OUTBUFSIZE = 32K * N (related to inflate's 32K window size)
*
* 2) Max in-memory file size is OUTBUFSIZE * PTRBUFSIZE
* which is 64 MBytes by default (32K * 2K).
*
*/
#ifndef BUFFERTHRESHOLD
#define BUFFERTHRESHOLD (256 * 1024L)
#endif
#ifndef INPBUFSIZE
#define INPBUFSIZE ( 8 * 1024 )
#endif
#ifndef PTRBUFSIZE
#define PTRBUFSIZE ( 2 * 1024 )
#endif
#ifndef OUTBUFSIZE
#define OUTBUFSIZE ((unsigned int) ( 32 * 1024L))
#endif
#define MAXFILESIZE (OUTBUFSIZE * (long) PTRBUFSIZE)
/*
* Macro for short-hand reference to ZipioState (from ZFILE *)
*/
#define ZS ((struct ZipioState *) stream)
/*
* Macro to manipulate Zgetc() cache
*/
#define CACHEINIT \
zs->ptr = NULL; \
zs->len = 0;
#define CACHEUPDATE \
if (ZS->ptr) \
{ \
ZS->fileposition &= ~((long) (OUTBUFSIZE-1)); \
ZS->fileposition += ZS->ptr - ZS->getbuf; \
ZS->ptr = NULL; \
} \
ZS->len = 0;
/*
* Macros for run-time type identification
*/
#ifndef RUNTIMEENABLE
#define RUNTIMEENABLE 0
#endif
#if RUNTIMEENABLE
#define ZIPIOSTATETYPE 0x0110f00fL
#define RUNTIMEINIT \
zs->runtimetypeid1 = ZIPIOSTATETYPE; \
zs->runtimetypeid2 = ZIPIOSTATETYPE;
#define RUNTIMECHECK \
if (!ZS || (ZS->runtimetypeid1 != ZIPIOSTATETYPE) \
|| (ZS->runtimetypeid2 != ZIPIOSTATETYPE)) return -1;
#else
#define RUNTIMEINIT
#define RUNTIMECHECK
#endif
/*
* Macros for converting bytes to unsigned integers
*/
#define GETUINT4(ptr, i4) \
{ \
i4 = (((unsigned long) *(((unsigned char *) (ptr)) + 0)) ) | \
(((unsigned long) *(((unsigned char *) (ptr)) + 1)) << 8) | \
(((unsigned long) *(((unsigned char *) (ptr)) + 2)) << 16) | \
(((unsigned long) *(((unsigned char *) (ptr)) + 3)) << 24) ; \
}
#define GETUINT2(ptr, i2) \
{ \
i2 = (((unsigned int) *(((unsigned char *) (ptr)) + 0)) ) | \
(((unsigned int) *(((unsigned char *) (ptr)) + 1)) << 8) ; \
}
/* Structure to hold state for decoding zip files */
struct ZipioState {
/* Fields overlaid with ZFILE structure */
int len; /* length of Zgetc cache */
unsigned char *ptr; /* pointer to Zgetc cache */
/* Fields invisible to users of ZFILE structure */
unsigned long runtimetypeid1; /* to detect run-time errors */
int errorencountered; /* error encountered flag */
/* Buffering state */
unsigned char inpbuf[INPBUFSIZE]; /* inp buffer from zip file */
unsigned char *ptrbuf[PTRBUFSIZE]; /* pointers to in-memory bufs */
unsigned char getbuf[OUTBUFSIZE]; /* buffer for use by Zgetc */
long getoff; /* starting offset of getbuf */
FILE *tmpfil; /* file ptr to temp file */
/* Amount of input data inflated */
unsigned long inpinf;
unsigned long outinf;
/* Zip file header */
unsigned long sign; /* local file header signature (0x04034b50) */
unsigned int vers; /* version needed to extract 2 bytes */
unsigned int flag; /* general purpose bit flag 2 bytes */
unsigned int comp; /* compression method 2 bytes */
unsigned int mtim; /* last mod file time 2 bytes */
unsigned int mdat; /* last mod file date 2 bytes */
unsigned long crc3; /* crc-32 4 bytes */
unsigned long csiz; /* compressed size 4 bytes */
unsigned long usiz; /* uncompressed size 4 bytes */
unsigned int flen; /* filename length 2 bytes */
unsigned int elen; /* extra field length 2 bytes */
/* Application state */
FILE *OpenFile; /* currently open file */
void *inflatestate; /* current state for inflate */
unsigned long fileposition; /* current file position */
unsigned long filecrc; /* current crc */
unsigned long runtimetypeid2; /* to detect run-time errors */
};
/*
* Utility routines to handle uncompressed file buffers
*/
/* Initialize buffering */
static void BufferInitialize(
struct ZipioState *zs,
int doinflate
)
{
zs->getoff = -1;
zs->tmpfil = NULL;
/*
* If not inflating, use the input file
*/
if (!doinflate)
{
zs->tmpfil = zs->OpenFile;
/* Get the uncompressed file size */
fseek(zs->tmpfil, 0, SEEK_END);
zs->usiz = ftell(zs->tmpfil);
zs->outinf = zs->usiz;
/* Start at the beginning */
fseek(zs->tmpfil, 0, SEEK_SET);
}
/* If there's no file open, see if it's big enough for temp file */
if (!zs->tmpfil)
{
if (zs->usiz >= BUFFERTHRESHOLD)
zs->tmpfil = tmpfile();
}
/* If there's no file open, then use memory buffering */
if (!zs->tmpfil)
{
int i;
for (i=0; i<PTRBUFSIZE; i++)
zs->ptrbuf[i] = NULL;
}
}
/* pump data till length bytes of file are inflated or error encountered */
static int BufferPump(struct ZipioState *zs, long length)
{
size_t inplen, ret;
/* Check to see if the length is valid */
if (length > zs->usiz) return TRUE;
/* Loop till enough data is pumped */
while (!zs->errorencountered && (zs->outinf < length))
{
/* Compute how much data to read */
if ((zs->csiz - zs->inpinf) < INPBUFSIZE)
inplen = (size_t) (zs->csiz - zs->inpinf);
else
inplen = INPBUFSIZE;
if (inplen <= 0) return TRUE;
/* Read some data from the file */
ret = fread(zs->inpbuf, 1, inplen, zs->OpenFile);
if (ret != inplen) return TRUE;
/* Update how much data has been read from the file */
zs->inpinf += inplen;
/* Pump this data into the decompressor */
if (InflatePutBuffer(zs->inflatestate, zs->inpbuf, inplen)) return TRUE;
}
return FALSE;
}
/* Read from the buffer */
static int BufferRead(
struct ZipioState *zs,
long offset,
unsigned char *buffer,
long length
)
{
/*
* Make sure enough bytes have been inflated
* Note that the correction for reading past EOF has to
* be done before calling this routine
*/
if (BufferPump(zs, offset+length)) return TRUE;
/* If using file buffering, just get the data from the file */
if (zs->tmpfil)
{
if (fseek(zs->tmpfil, offset, SEEK_SET)) return TRUE;
if (fread(buffer, 1, (size_t) length, zs->tmpfil) != length) return TRUE;
}
/* If no temp file, use memory buffering */
else
{
unsigned int i;
unsigned int off, len;
unsigned char *ptr;
long tmpoff;
unsigned char *tmpbuf;
long tmplen;
/* Save copies of offset, buffer and length for the loop */
tmpoff = offset;
tmpbuf = buffer;
tmplen = length;
/* Validate the transfer */
if (tmpoff+tmplen > MAXFILESIZE) return TRUE;
/* Loop till done */
while (tmplen)
{
/* Get a pointer to the next block */
i = (unsigned int) (tmpoff / OUTBUFSIZE);
ptr = zs->ptrbuf[i];
if (!ptr) return TRUE;
/* Get the offset,length for this block */
off = (unsigned int) (tmpoff & (OUTBUFSIZE-1));
len = OUTBUFSIZE - off;
if (len > tmplen) len = (unsigned int) tmplen;
/* Get the starting pointer for the transfer */
ptr += off;
/* Copy the data for this block */
#ifdef MEMCPY
memcpy(tmpbuf, ptr, len);
#else
for (i=0; i<len; i++)
tmpbuf[i] = ptr[i];
#endif
/* Update the offset, buffer, and length */
tmpoff += len;
tmpbuf += len;
tmplen -= len;
}
}
/* return success */
return FALSE;
}
/* Append to the buffer */
static int BufferAppend(
struct ZipioState *zs,
unsigned char *buffer,
long length
)
{
/* If using file buffering, just append the data from the file */
if (zs->tmpfil)
{
if (fseek(zs->tmpfil, zs->outinf, SEEK_SET)) return TRUE;
if (fwrite(buffer, 1, (size_t) length, zs->tmpfil) != length) return TRUE;
}
/* If no temp file, use memory buffering */
else
{
unsigned int i;
unsigned int off, len;
unsigned char *ptr;
long tmpoff;
unsigned char *tmpbuf;
long tmplen;
/* Save copies of outinf, buffer and length for the loop */
tmpoff = zs->outinf;
tmpbuf = buffer;
tmplen = length;
/* Validate the transfer */
if (tmpoff+tmplen > MAXFILESIZE) return TRUE;
/* Loop till done */
while (tmplen)
{
/* Get a pointer to the next block */
i = (unsigned int) (tmpoff / OUTBUFSIZE);
ptr = zs->ptrbuf[i];
if (!ptr)
{
ptr = (unsigned char *) malloc(OUTBUFSIZE);
if (!ptr) return TRUE;
zs->ptrbuf[i] = ptr;
}
/* Get the offset,length for this block */
off = (unsigned int) (tmpoff & (OUTBUFSIZE-1));
len = OUTBUFSIZE - off;
if (len > tmplen) len = (unsigned int) tmplen;
/* Get the starting pointer for the transfer */
ptr += off;
/* Copy the data for this block */
#ifdef MEMCPY
memcpy(ptr, tmpbuf, len);
#else
for (i=0; i<len; i++)
ptr[i] = tmpbuf[i];
#endif
/* Update the offset, buffer, and length */
tmpoff += len;
tmpbuf += len;
tmplen -= len;
}
}
/* Update the output buffer length */
zs->outinf += length;
/* return success */
return FALSE;
}
/* Terminate buffering */
static void BufferTerminate(
struct ZipioState *zs
)
{
/* If reading directly from the uncompressed file, just mark with NULL */
if (zs->tmpfil == zs->OpenFile)
{
zs->tmpfil = NULL;
}
/* If using the a temporary file, close it */
else if (zs->tmpfil)
{
fclose(zs->tmpfil);
zs->tmpfil = NULL;
}
/* If doing memory buffering, free the buffers */
else
{
int i;
for (i=0; i<PTRBUFSIZE; i++)
if (zs->ptrbuf[i]) free(zs->ptrbuf[i]);
}
}
/*
* callout routines for InflateInitialize
*/
static int inflate_putbuffer( /* returns 0 on success */
void *stream, /* opaque ptr from Initialize */
unsigned char *buffer, /* buffer to put */
long length /* length of buffer */
)
{
RUNTIMECHECK;
/* If the write will go past the end of file, return an error */
if (ZS->outinf + length > ZS->usiz) return TRUE;
/* Update the CRC */
ZS->filecrc = CrcUpdate(ZS->filecrc, buffer, length);
/* Append to the buffer */
if (BufferAppend(ZS, buffer, length)) return TRUE;
/* Return success */
return FALSE;
}
static void *inflate_malloc(long length)
{
return malloc((size_t) length);
}
static void inflate_free(void *buffer)
{
free(buffer);
}
ZFILE *Zopen(const char *path, const char *mode)
{
struct ZipioState *zs;
long inplen;
/* Allocate the ZipioState memory area */
zs = (struct ZipioState *) malloc(sizeof(struct ZipioState));
if (!zs) return NULL;
/* Set up the initial values of the inflate state */
CACHEINIT;
RUNTIMEINIT;
zs->errorencountered = FALSE;
zs->inpinf = 0;
zs->outinf = 0;
zs->fileposition = 0;
zs->filecrc = 0xffffffffL;
/* Open the real file */
zs->OpenFile = fopen(path, mode);
if (!zs->OpenFile)
{
free(zs);
return NULL;
}
/* Read the first input buffer */
if ((inplen = (long) fread(zs->inpbuf, 1, INPBUFSIZE, zs->OpenFile)) >= 30)
{
GETUINT4(zs->inpbuf+ 0, zs->sign);
GETUINT2(zs->inpbuf+ 4, zs->vers);
GETUINT2(zs->inpbuf+ 6, zs->flag);
GETUINT2(zs->inpbuf+ 8, zs->comp);
GETUINT2(zs->inpbuf+10, zs->mtim);
GETUINT2(zs->inpbuf+12, zs->mdat);
GETUINT4(zs->inpbuf+14, zs->crc3);
GETUINT4(zs->inpbuf+18, zs->csiz);
GETUINT4(zs->inpbuf+22, zs->usiz);
GETUINT2(zs->inpbuf+26, zs->flen);
GETUINT2(zs->inpbuf+28, zs->elen);
#ifdef PRINTZIPHEADER
fprintf(stderr, "local file header signature hex %8lx\n", zs->sign);
fprintf(stderr, "version needed to extract %8d\n" , zs->vers);
fprintf(stderr, "general purpose bit flag hex %8x\n" , zs->flag);
fprintf(stderr, "compression method %8d\n" , zs->comp);
fprintf(stderr, "last mod file time %8d\n" , zs->mtim);
fprintf(stderr, "last mod file date %8d\n" , zs->mdat);
fprintf(stderr, "crc-32 hex %8lx\n", zs->crc3);
fprintf(stderr, "compressed size %8ld\n", zs->csiz);
fprintf(stderr, "uncompressed size %8ld\n", zs->usiz);
fprintf(stderr, "filename length %8d\n" , zs->flen);
fprintf(stderr, "extra field length %8d\n" , zs->elen);
#endif
}
else
{
zs->sign = 0;
}
/*
* If the file isn't a zip file, set up to read it normally
*/
if ((zs->sign != ZIPSIGNATURE) ||
(zs->flag & 1) ||
(zs->comp != 8) ||
(inplen <= 30 + zs->flen + zs->elen) )
{
/* Initialize buffering */
BufferInitialize(zs, FALSE);
zs->inflatestate = NULL;
}
else
{
/* Initialize buffering */
BufferInitialize(zs, TRUE);
zs->inflatestate = InflateInitialize(
(void *) zs,
inflate_putbuffer,
inflate_malloc,
inflate_free
);
if (InflatePutBuffer(zs->inflatestate,
zs->inpbuf+30+zs->flen+zs->elen,
inplen-30-zs->flen-zs->elen
)
)
zs->errorencountered = TRUE;
zs->inpinf += inplen-30-zs->flen-zs->elen;
}
/* Return this state info to the caller */
return (ZFILE *) zs;
}
int _Zgetc(ZFILE *stream)
{
long offset, length;
int off;
RUNTIMECHECK;
if (ZS->errorencountered) return -1;
CACHEUPDATE;
/* If already at EOF, return */
if (ZS->fileposition >= ZS->usiz) return -1;
/* If data isn't in current outbuf, get it */
offset = ZS->fileposition & ~((long) (OUTBUFSIZE-1));
length = ZS->usiz - offset;
if (length > OUTBUFSIZE) length = OUTBUFSIZE;
if (ZS->getoff != offset)
{
if (BufferRead(ZS, offset, ZS->getbuf, length)) return -1;
ZS->getoff = offset;
}
/* Set up the cache */
off = (int) (ZS->fileposition & (OUTBUFSIZE-1));
ZS->len = (int) (length - off);
ZS->ptr = ZS->getbuf + off;
/* Return the character */
ZS->len--;
return *(ZS->ptr++);
}
size_t Zread(void *ptr, size_t size, size_t n, ZFILE *stream)
{
long length;
RUNTIMECHECK;
if (ZS->errorencountered) return 0;
CACHEUPDATE;
/* Compute the length requested */
length = size * (long) n;
/* Adjust the length to account for premature EOF */
if (ZS->fileposition+length > ZS->usiz)
length = ZS->usiz - ZS->fileposition;
/* If the length is zero, then just return an EOF error */
if (length <= 0) return 0;
/* Make the length a multiple of size */
length /= size;
length *= size;
/* If the length is zero, then just return an EOF error */
if (length <= 0) return 0;
/* Read from the buffer */
if (BufferRead(ZS, ZS->fileposition, (unsigned char *) ptr, length))
return 0;
/* Update the file position */
ZS->fileposition += length;
/* Return the number of items transferred */
return (size_t) (length / size);
}
int Zseek(ZFILE *stream, long offset, int whence)
{
long newoffset;
RUNTIMECHECK;
if (ZS->errorencountered) return -1;
CACHEUPDATE;
if (whence == SEEK_SET)
{
newoffset = offset;
}
else if (whence == SEEK_CUR)
{
newoffset = ZS->fileposition + offset;
}
else if (whence == SEEK_END)
{
newoffset = ZS->fileposition + ZS->usiz;
}
else
{
return -1;
}
if ((newoffset < 0) || (newoffset > ZS->usiz)) return -1;
ZS->fileposition = newoffset;
return 0;
}
long Ztell(ZFILE *stream)
{
RUNTIMECHECK;
if (ZS->errorencountered) return -1;
CACHEUPDATE;
return ZS->fileposition;
}
int Zclose(ZFILE *stream)
{
int ret;
RUNTIMECHECK;
CACHEUPDATE;
/* terminate the inflate routines, and check for errors */
if (ZS->inflatestate)
{
if (InflateTerminate(ZS->inflatestate))
ZS->errorencountered = TRUE;
/* Check that the CRC is OK */
if (ZS->filecrc != (ZS->crc3 ^ 0xffffffffL))
ZS->errorencountered = TRUE;
}
/* save the final error status */
ret = ZS->errorencountered;
/* terminate the buffering */
BufferTerminate(ZS);
/* free the ZipioState structure */
free(ZS);
/* return the final error status */
return ret;
}

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