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/* ----------------------------------------------------------------------- *
*
* Copyright 2003-2008 H. Peter Anvin - All Rights Reserved
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom
* the Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall
* be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* ----------------------------------------------------------------------- */
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <syslinux/zio.h>
#include "file.h"
#include "zlib.h"
/*
* zopen.c
*
* Open an ordinary file, possibly compressed; if so, insert
* an appropriate decompressor.
*/
int __file_get_block(struct file_info *fp);
int __file_close(struct file_info *fp);
static ssize_t gzip_file_read(struct file_info *, void *, size_t);
static int gzip_file_close(struct file_info *);
static const struct input_dev gzip_file_dev = {
.dev_magic = __DEV_MAGIC,
.flags = __DEV_FILE | __DEV_INPUT,
.fileflags = O_RDONLY,
.read = gzip_file_read,
.close = gzip_file_close,
.open = NULL,
};
static int gzip_file_init(struct file_info *fp)
{
z_streamp zs = calloc(1, sizeof(z_stream));
if (!zs)
return -1;
fp->i.pvt = zs;
zs->next_in = (void *)fp->i.datap;
zs->avail_in = fp->i.nbytes;
if (inflateInit2(zs, 15 + 32) != Z_OK) {
errno = EIO;
return -1;
}
fp->iop = &gzip_file_dev;
fp->i.fd.size = -1; /* Unknown */
return 0;
}
static ssize_t gzip_file_read(struct file_info *fp, void *ptr, size_t n)
{
z_streamp zs = fp->i.pvt;
int rv;
ssize_t bytes;
ssize_t nout = 0;
unsigned char *p = ptr;
while (n) {
zs->next_out = p;
zs->avail_out = n;
if (!zs->avail_in && fp->i.fd.handle) {
if (__file_get_block(fp))
return nout ? nout : -1;
zs->next_in = (void *)fp->i.datap;
zs->avail_in = fp->i.nbytes;
}
rv = inflate(zs, Z_SYNC_FLUSH);
bytes = n - zs->avail_out;
nout += bytes;
p += bytes;
n -= bytes;
switch (rv) {
case Z_DATA_ERROR:
case Z_NEED_DICT:
case Z_BUF_ERROR:
case Z_STREAM_ERROR:
default:
errno = EIO;
return nout ? nout : -1;
case Z_MEM_ERROR:
errno = ENOMEM;
return nout ? nout : -1;
case Z_STREAM_END:
return nout;
case Z_OK:
break;
}
}
return nout;
}
static int gzip_file_close(struct file_info *fp)
{
z_streamp zs = fp->i.pvt;
inflateEnd(zs);
free(zs);
return __file_close(fp);
}
int zopen(const char *pathname, int flags, ...)
{
int fd, rv;
struct file_info *fp;
/* We don't actually give a hoot about the creation bits... */
fd = open(pathname, flags, 0);
if (fd < 0)
return -1;
fp = &__file_info[fd];
/* Need to get the first block into the buffer, but not consumed */
if (__file_get_block(fp))
goto err;
if (fp->i.nbytes >= 14 &&
(uint8_t) fp->i.buf[0] == 037 &&
(uint8_t) fp->i.buf[1] == 0213 && /* gzip */
fp->i.buf[2] == 8) /* deflate */
rv = gzip_file_init(fp);
else
rv = 0; /* Plain file */
if (!rv)
return fd;
err:
close(fd);
return -1;
}
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