1 /*
2 * This file uses XZ Embedded library code which is written
3 * by Lasse Collin <lasse.collin@tukaani.org>
4 * and Igor Pavlov <http://7-zip.org/>
5 *
6 * See README file in unxz/ directory for more information.
7 *
8 * This file is:
9 * Copyright (C) 2010 Denys Vlasenko <vda.linux@googlemail.com>
10 * Licensed under GPLv2, see file LICENSE in this source tree.
11 */
12 #include "libbb.h"
13 #include "bb_archive.h"
14
15 #define XZ_FUNC FAST_FUNC
16 #define XZ_EXTERN static
17
18 #define XZ_DEC_DYNALLOC
19
20 /* Skip check (rather than fail) of unsupported hash functions */
21 #define XZ_DEC_ANY_CHECK 1
22
23 /* We use our own crc32 function */
24 #define XZ_INTERNAL_CRC32 0
xz_crc32(const uint8_t * buf,size_t size,uint32_t crc)25 static uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc)
26 {
27 return ~crc32_block_endian0(~crc, buf, size, global_crc32_table);
28 }
29
30 /* We use arch-optimized unaligned fixed-endian accessors.
31 * They have been moved to libbb (proved to be useful elsewhere as well),
32 * just check that we have them defined:
33 */
34 #if !defined(get_unaligned_le32) \
35 || !defined(get_unaligned_be32) \
36 || !defined(put_unaligned_le32) \
37 || !defined(put_unaligned_be32)
38 # error get_unaligned_le32 accessors are not defined
39 #endif
40
41 #include "unxz/xz_dec_bcj.c"
42 #include "unxz/xz_dec_lzma2.c"
43 #include "unxz/xz_dec_stream.c"
44
IF_DESKTOP(long long)45 IF_DESKTOP(long long) int FAST_FUNC
46 unpack_xz_stream(transformer_state_t *xstate)
47 {
48 enum xz_ret xz_result;
49 struct xz_buf iobuf;
50 struct xz_dec *state;
51 unsigned char *membuf;
52 IF_DESKTOP(long long) int total = 0;
53
54 if (!global_crc32_table)
55 global_crc32_new_table_le();
56
57 memset(&iobuf, 0, sizeof(iobuf));
58 membuf = xmalloc(2 * BUFSIZ);
59 iobuf.in = membuf;
60 iobuf.out = membuf + BUFSIZ;
61 iobuf.out_size = BUFSIZ;
62
63 if (!xstate || xstate->signature_skipped) {
64 /* Preload XZ file signature */
65 strcpy((char*)membuf, HEADER_MAGIC);
66 iobuf.in_size = HEADER_MAGIC_SIZE;
67 } /* else: let xz code read & check it */
68
69 /* Limit memory usage to about 64 MiB. */
70 state = xz_dec_init(XZ_DYNALLOC, 64*1024*1024);
71
72 xz_result = X_OK;
73 while (1) {
74 if (iobuf.in_pos == iobuf.in_size) {
75 int rd = safe_read(xstate->src_fd, membuf, BUFSIZ);
76 if (rd < 0) {
77 bb_simple_error_msg(bb_msg_read_error);
78 total = -1;
79 break;
80 }
81 if (rd == 0 && xz_result == XZ_STREAM_END)
82 break;
83 iobuf.in_size = rd;
84 iobuf.in_pos = 0;
85 }
86 if (xz_result == XZ_STREAM_END) {
87 /*
88 * Try to start decoding next concatenated stream.
89 * Stream padding must always be a multiple of four
90 * bytes to preserve four-byte alignment. To keep the
91 * code slightly smaller, we aren't as strict here as
92 * the .xz spec requires. We just skip all zero-bytes
93 * without checking the alignment and thus can accept
94 * files that aren't valid, e.g. the XZ utils test
95 * files bad-0pad-empty.xz and bad-0catpad-empty.xz.
96 */
97 do {
98 if (membuf[iobuf.in_pos] != 0) {
99 /* There is more data, but is it XZ data?
100 * Example: dpkg-deb -f busybox_1.30.1-4_amd64.deb
101 * reads control.tar.xz "control" file
102 * inside the ar archive, but tar.xz
103 * extraction code reaches end of xz data,
104 * reached this code and reads the beginning
105 * of data.tar.xz's ar header, which isn't xz data,
106 * and prints "corrupted data".
107 * The correct solution is to not read
108 * past nested archive (to simulate EOF).
109 * This is a workaround:
110 */
111 if (membuf[iobuf.in_pos] != 0xfd) {
112 /* It's definitely not a xz signature
113 * (which is 0xfd,"7zXZ",0x00).
114 */
115 goto end;
116 }
117 xz_dec_reset(state);
118 goto do_run;
119 }
120 iobuf.in_pos++;
121 } while (iobuf.in_pos < iobuf.in_size);
122 }
123 do_run:
124 // bb_error_msg(">in pos:%d size:%d out pos:%d size:%d",
125 // iobuf.in_pos, iobuf.in_size, iobuf.out_pos, iobuf.out_size);
126 xz_result = xz_dec_run(state, &iobuf);
127 // bb_error_msg("<in pos:%d size:%d out pos:%d size:%d r:%d",
128 // iobuf.in_pos, iobuf.in_size, iobuf.out_pos, iobuf.out_size, xz_result);
129 if (iobuf.out_pos) {
130 xtransformer_write(xstate, iobuf.out, iobuf.out_pos);
131 IF_DESKTOP(total += iobuf.out_pos;)
132 iobuf.out_pos = 0;
133 }
134 if (xz_result == XZ_STREAM_END) {
135 /*
136 * Can just "break;" here, if not for concatenated
137 * .xz streams.
138 * Checking for padding may require buffer
139 * replenishment. Can't do it here.
140 */
141 continue;
142 }
143 if (xz_result != XZ_OK && xz_result != XZ_UNSUPPORTED_CHECK) {
144 bb_simple_error_msg("corrupted data");
145 total = -1;
146 break;
147 }
148 }
149 end:
150 xz_dec_end(state);
151 free(membuf);
152
153 return total;
154 }
155