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
lzma_strerror(lzma_ret ret)17 static 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
lzma_decompress_to_file(const char * input,int output_fd)35 int 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;
101 err_lzma_end:
102 lzma_end(&strm);
103 err_fclose:
104 fclose(infile);
105 return err;
106 }
107
lzma_is_compressed(const char * input)108 bool 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