https://github.com/torvalds/linux
Tip revision: 0477e92881850d44910a7e94fc2c46f96faa131f authored by Linus Torvalds on 06 December 2020, 22:25:12 UTC
Linux 5.10-rc7
Linux 5.10-rc7
Tip revision: 0477e92
lzma.c
// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include <lzma.h>
#include <stdio.h>
#include <linux/compiler.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "compress.h"
#include "debug.h"
#include <string.h>
#include <unistd.h>
#include <internal/lib.h>
#define BUFSIZE 8192
static const char *lzma_strerror(lzma_ret ret)
{
switch ((int) ret) {
case LZMA_MEM_ERROR:
return "Memory allocation failed";
case LZMA_OPTIONS_ERROR:
return "Unsupported decompressor flags";
case LZMA_FORMAT_ERROR:
return "The input is not in the .xz format";
case LZMA_DATA_ERROR:
return "Compressed file is corrupt";
case LZMA_BUF_ERROR:
return "Compressed file is truncated or otherwise corrupt";
default:
return "Unknown error, possibly a bug";
}
}
int lzma_decompress_to_file(const char *input, int output_fd)
{
lzma_action action = LZMA_RUN;
lzma_stream strm = LZMA_STREAM_INIT;
lzma_ret ret;
int err = -1;
u8 buf_in[BUFSIZE];
u8 buf_out[BUFSIZE];
FILE *infile;
infile = fopen(input, "rb");
if (!infile) {
pr_err("lzma: fopen failed on %s: '%s'\n",
input, strerror(errno));
return -1;
}
ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED);
if (ret != LZMA_OK) {
pr_err("lzma: lzma_stream_decoder failed %s (%d)\n",
lzma_strerror(ret), ret);
goto err_fclose;
}
strm.next_in = NULL;
strm.avail_in = 0;
strm.next_out = buf_out;
strm.avail_out = sizeof(buf_out);
while (1) {
if (strm.avail_in == 0 && !feof(infile)) {
strm.next_in = buf_in;
strm.avail_in = fread(buf_in, 1, sizeof(buf_in), infile);
if (ferror(infile)) {
pr_err("lzma: read error: %s\n", strerror(errno));
goto err_fclose;
}
if (feof(infile))
action = LZMA_FINISH;
}
ret = lzma_code(&strm, action);
if (strm.avail_out == 0 || ret == LZMA_STREAM_END) {
ssize_t write_size = sizeof(buf_out) - strm.avail_out;
if (writen(output_fd, buf_out, write_size) != write_size) {
pr_err("lzma: write error: %s\n", strerror(errno));
goto err_fclose;
}
strm.next_out = buf_out;
strm.avail_out = sizeof(buf_out);
}
if (ret != LZMA_OK) {
if (ret == LZMA_STREAM_END)
break;
pr_err("lzma: failed %s\n", lzma_strerror(ret));
goto err_fclose;
}
}
err = 0;
err_fclose:
fclose(infile);
return err;
}
bool lzma_is_compressed(const char *input)
{
int fd = open(input, O_RDONLY);
const uint8_t magic[6] = { 0xFD, '7', 'z', 'X', 'Z', 0x00 };
char buf[6] = { 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;
}