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_debug("lzma: fopen failed on %s: '%s'\n", input, strerror(errno));
49		return -1;
50	}
51
52	ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED);
53	if (ret != LZMA_OK) {
54		pr_debug("lzma: lzma_stream_decoder failed %s (%d)\n", lzma_strerror(ret), ret);
55		goto err_fclose;
56	}
57
58	strm.next_in   = NULL;
59	strm.avail_in  = 0;
60	strm.next_out  = buf_out;
61	strm.avail_out = sizeof(buf_out);
62
63	while (1) {
64		if (strm.avail_in == 0 && !feof(infile)) {
65			strm.next_in  = buf_in;
66			strm.avail_in = fread(buf_in, 1, sizeof(buf_in), infile);
67
68			if (ferror(infile)) {
69				pr_debug("lzma: read error: %s\n", strerror(errno));
70				goto err_lzma_end;
71			}
72
73			if (feof(infile))
74				action = LZMA_FINISH;
75		}
76
77		ret = lzma_code(&strm, action);
78
79		if (strm.avail_out == 0 || ret == LZMA_STREAM_END) {
80			ssize_t write_size = sizeof(buf_out) - strm.avail_out;
81
82			if (writen(output_fd, buf_out, write_size) != write_size) {
83				pr_debug("lzma: write error: %s\n", strerror(errno));
84				goto err_lzma_end;
85			}
86
87			strm.next_out  = buf_out;
88			strm.avail_out = sizeof(buf_out);
89		}
90
91		if (ret != LZMA_OK) {
92			if (ret == LZMA_STREAM_END)
93				break;
94
95			pr_debug("lzma: failed %s\n", lzma_strerror(ret));
96			goto err_lzma_end;
97		}
98	}
99
100	err = 0;
101err_lzma_end:
102	lzma_end(&strm);
103err_fclose:
104	fclose(infile);
105	return err;
106}
107
108bool lzma_is_compressed(const char *input)
109{
110	int fd = open(input, O_RDONLY);
111	const uint8_t magic[6] = { 0xFD, '7', 'z', 'X', 'Z', 0x00 };
112	char buf[6] = { 0 };
113	ssize_t rc;
114
115	if (fd < 0)
116		return -1;
117
118	rc = read(fd, buf, sizeof(buf));
119	close(fd);
120	return rc == sizeof(buf) ?
121	       memcmp(buf, magic, sizeof(buf)) == 0 : false;
122}
123