98 строки
1.8 KiB
C
98 строки
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
#include <fcntl.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/mman.h>
|
|
#include <zlib.h>
|
|
#include <linux/compiler.h>
|
|
#include <internal/lib.h>
|
|
|
|
#include "util/compress.h"
|
|
|
|
#define CHUNK_SIZE 16384
|
|
|
|
int gzip_decompress_to_file(const char *input, int output_fd)
|
|
{
|
|
int ret = Z_STREAM_ERROR;
|
|
int input_fd;
|
|
void *ptr;
|
|
int len;
|
|
struct stat stbuf;
|
|
unsigned char buf[CHUNK_SIZE];
|
|
z_stream zs = {
|
|
.zalloc = Z_NULL,
|
|
.zfree = Z_NULL,
|
|
.opaque = Z_NULL,
|
|
.avail_in = 0,
|
|
.next_in = Z_NULL,
|
|
};
|
|
|
|
input_fd = open(input, O_RDONLY);
|
|
if (input_fd < 0)
|
|
return -1;
|
|
|
|
if (fstat(input_fd, &stbuf) < 0)
|
|
goto out_close;
|
|
|
|
ptr = mmap(NULL, stbuf.st_size, PROT_READ, MAP_PRIVATE, input_fd, 0);
|
|
if (ptr == MAP_FAILED)
|
|
goto out_close;
|
|
|
|
if (inflateInit2(&zs, 16 + MAX_WBITS) != Z_OK)
|
|
goto out_unmap;
|
|
|
|
zs.next_in = ptr;
|
|
zs.avail_in = stbuf.st_size;
|
|
|
|
do {
|
|
zs.next_out = buf;
|
|
zs.avail_out = CHUNK_SIZE;
|
|
|
|
ret = inflate(&zs, Z_NO_FLUSH);
|
|
switch (ret) {
|
|
case Z_NEED_DICT:
|
|
ret = Z_DATA_ERROR;
|
|
/* fall through */
|
|
case Z_DATA_ERROR:
|
|
case Z_MEM_ERROR:
|
|
goto out;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
len = CHUNK_SIZE - zs.avail_out;
|
|
if (writen(output_fd, buf, len) != len) {
|
|
ret = Z_DATA_ERROR;
|
|
goto out;
|
|
}
|
|
|
|
} while (ret != Z_STREAM_END);
|
|
|
|
out:
|
|
inflateEnd(&zs);
|
|
out_unmap:
|
|
munmap(ptr, stbuf.st_size);
|
|
out_close:
|
|
close(input_fd);
|
|
|
|
return ret == Z_STREAM_END ? 0 : -1;
|
|
}
|
|
|
|
bool gzip_is_compressed(const char *input)
|
|
{
|
|
int fd = open(input, O_RDONLY);
|
|
const uint8_t magic[2] = { 0x1f, 0x8b };
|
|
char buf[2] = { 0 };
|
|
ssize_t rc;
|
|
|
|
if (fd < 0)
|
|
return -1;
|
|
|
|
rc = read(fd, buf, sizeof(buf));
|
|
close(fd);
|
|
return rc == sizeof(buf) ?
|
|
memcmp(buf, magic, sizeof(buf)) == 0 : false;
|
|
}
|