1
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_fclose;
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_fclose;
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_fclose;
99 }
100 }
101
102 err = 0;
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
