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_stream_to_file(FILE * infile,int output_fd)35 int lzma_decompress_stream_to_file(FILE *infile, 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
45 ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED);
46 if (ret != LZMA_OK) {
47 pr_debug("lzma: lzma_stream_decoder failed %s (%d)\n", lzma_strerror(ret), ret);
48 return err;
49 }
50
51 strm.next_in = NULL;
52 strm.avail_in = 0;
53 strm.next_out = buf_out;
54 strm.avail_out = sizeof(buf_out);
55
56 while (1) {
57 if (strm.avail_in == 0 && !feof(infile)) {
58 strm.next_in = buf_in;
59 strm.avail_in = fread(buf_in, 1, sizeof(buf_in), infile);
60
61 if (ferror(infile)) {
62 pr_debug("lzma: read error: %s\n", strerror(errno));
63 goto err_lzma_end;
64 }
65
66 if (feof(infile))
67 action = LZMA_FINISH;
68 }
69
70 ret = lzma_code(&strm, action);
71
72 if (strm.avail_out == 0 || ret == LZMA_STREAM_END) {
73 ssize_t write_size = sizeof(buf_out) - strm.avail_out;
74
75 if (writen(output_fd, buf_out, write_size) != write_size) {
76 pr_debug("lzma: write error: %s\n", strerror(errno));
77 goto err_lzma_end;
78 }
79
80 strm.next_out = buf_out;
81 strm.avail_out = sizeof(buf_out);
82 }
83
84 if (ret != LZMA_OK) {
85 if (ret == LZMA_STREAM_END)
86 break;
87
88 pr_debug("lzma: failed %s\n", lzma_strerror(ret));
89 goto err_lzma_end;
90 }
91 }
92
93 err = 0;
94 err_lzma_end:
95 lzma_end(&strm);
96 return err;
97 }
98
lzma_decompress_to_file(const char * input,int output_fd)99 int lzma_decompress_to_file(const char *input, int output_fd)
100 {
101 FILE *infile;
102 int ret;
103
104 infile = fopen(input, "rb");
105 if (!infile) {
106 pr_debug("lzma: fopen failed on %s: '%s'\n", input, strerror(errno));
107 return -1;
108 }
109
110 ret = lzma_decompress_stream_to_file(infile, output_fd);
111 fclose(infile);
112 return ret;
113 }
114
lzma_is_compressed(const char * input)115 bool lzma_is_compressed(const char *input)
116 {
117 int fd = open(input, O_RDONLY);
118 const uint8_t magic[6] = { 0xFD, '7', 'z', 'X', 'Z', 0x00 };
119 char buf[6] = { 0 };
120 ssize_t rc;
121
122 if (fd < 0)
123 return -1;
124
125 rc = read(fd, buf, sizeof(buf));
126 close(fd);
127 return rc == sizeof(buf) ?
128 memcmp(buf, magic, sizeof(buf)) == 0 : false;
129 }
130