cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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lzma.c (2706B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include <errno.h>
      3#include <lzma.h>
      4#include <stdio.h>
      5#include <linux/compiler.h>
      6#include <sys/types.h>
      7#include <sys/stat.h>
      8#include <fcntl.h>
      9#include "compress.h"
     10#include "debug.h"
     11#include <string.h>
     12#include <unistd.h>
     13#include <internal/lib.h>
     14
     15#define BUFSIZE 8192
     16
     17static const char *lzma_strerror(lzma_ret ret)
     18{
     19	switch ((int) ret) {
     20	case LZMA_MEM_ERROR:
     21		return "Memory allocation failed";
     22	case LZMA_OPTIONS_ERROR:
     23		return "Unsupported decompressor flags";
     24	case LZMA_FORMAT_ERROR:
     25		return "The input is not in the .xz format";
     26	case LZMA_DATA_ERROR:
     27		return "Compressed file is corrupt";
     28	case LZMA_BUF_ERROR:
     29		return "Compressed file is truncated or otherwise corrupt";
     30	default:
     31		return "Unknown error, possibly a bug";
     32	}
     33}
     34
     35int lzma_decompress_to_file(const char *input, int output_fd)
     36{
     37	lzma_action action = LZMA_RUN;
     38	lzma_stream strm   = LZMA_STREAM_INIT;
     39	lzma_ret ret;
     40	int err = -1;
     41
     42	u8 buf_in[BUFSIZE];
     43	u8 buf_out[BUFSIZE];
     44	FILE *infile;
     45
     46	infile = fopen(input, "rb");
     47	if (!infile) {
     48		pr_err("lzma: fopen failed on %s: '%s'\n",
     49		       input, strerror(errno));
     50		return -1;
     51	}
     52
     53	ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED);
     54	if (ret != LZMA_OK) {
     55		pr_err("lzma: lzma_stream_decoder failed %s (%d)\n",
     56			lzma_strerror(ret), ret);
     57		goto err_fclose;
     58	}
     59
     60	strm.next_in   = NULL;
     61	strm.avail_in  = 0;
     62	strm.next_out  = buf_out;
     63	strm.avail_out = sizeof(buf_out);
     64
     65	while (1) {
     66		if (strm.avail_in == 0 && !feof(infile)) {
     67			strm.next_in  = buf_in;
     68			strm.avail_in = fread(buf_in, 1, sizeof(buf_in), infile);
     69
     70			if (ferror(infile)) {
     71				pr_err("lzma: read error: %s\n", strerror(errno));
     72				goto err_lzma_end;
     73			}
     74
     75			if (feof(infile))
     76				action = LZMA_FINISH;
     77		}
     78
     79		ret = lzma_code(&strm, action);
     80
     81		if (strm.avail_out == 0 || ret == LZMA_STREAM_END) {
     82			ssize_t write_size = sizeof(buf_out) - strm.avail_out;
     83
     84			if (writen(output_fd, buf_out, write_size) != write_size) {
     85				pr_err("lzma: write error: %s\n", strerror(errno));
     86				goto err_lzma_end;
     87			}
     88
     89			strm.next_out  = buf_out;
     90			strm.avail_out = sizeof(buf_out);
     91		}
     92
     93		if (ret != LZMA_OK) {
     94			if (ret == LZMA_STREAM_END)
     95				break;
     96
     97			pr_err("lzma: failed %s\n", lzma_strerror(ret));
     98			goto err_lzma_end;
     99		}
    100	}
    101
    102	err = 0;
    103err_lzma_end:
    104	lzma_end(&strm);
    105err_fclose:
    106	fclose(infile);
    107	return err;
    108}
    109
    110bool lzma_is_compressed(const char *input)
    111{
    112	int fd = open(input, O_RDONLY);
    113	const uint8_t magic[6] = { 0xFD, '7', 'z', 'X', 'Z', 0x00 };
    114	char buf[6] = { 0 };
    115	ssize_t rc;
    116
    117	if (fd < 0)
    118		return -1;
    119
    120	rc = read(fd, buf, sizeof(buf));
    121	close(fd);
    122	return rc == sizeof(buf) ?
    123	       memcmp(buf, magic, sizeof(buf)) == 0 : false;
    124}