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e4e61fdb LP |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2011 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
5430f7f2 LP |
9 | under the terms of the GNU Lesser General Public License as published by |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
e4e61fdb LP |
11 | (at your option) any later version. |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
5430f7f2 | 16 | Lesser General Public License for more details. |
e4e61fdb | 17 | |
5430f7f2 | 18 | You should have received a copy of the GNU Lesser General Public License |
e4e61fdb LP |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
20 | ***/ | |
21 | ||
22 | #include <assert.h> | |
23 | #include <stdlib.h> | |
24 | #include <string.h> | |
25 | #include <lzma.h> | |
26 | ||
93b73b06 | 27 | #include "macro.h" |
e4e61fdb LP |
28 | #include "compress.h" |
29 | ||
30 | bool compress_blob(const void *src, uint64_t src_size, void *dst, uint64_t *dst_size) { | |
e4e61fdb | 31 | lzma_ret ret; |
76cc0bf6 | 32 | size_t out_pos = 0; |
e4e61fdb LP |
33 | |
34 | assert(src); | |
35 | assert(src_size > 0); | |
36 | assert(dst); | |
37 | assert(dst_size); | |
38 | ||
39 | /* Returns false if we couldn't compress the data or the | |
40 | * compressed result is longer than the original */ | |
41 | ||
76cc0bf6 ZJS |
42 | ret = lzma_easy_buffer_encode(LZMA_PRESET_DEFAULT, LZMA_CHECK_NONE, NULL, |
43 | src, src_size, dst, &out_pos, *dst_size); | |
e4e61fdb LP |
44 | if (ret != LZMA_OK) |
45 | return false; | |
46 | ||
e4e61fdb | 47 | /* Is it actually shorter? */ |
76cc0bf6 ZJS |
48 | if (out_pos == *dst_size) |
49 | return false; | |
e4e61fdb | 50 | |
76cc0bf6 ZJS |
51 | *dst_size = out_pos; |
52 | return true; | |
e4e61fdb LP |
53 | } |
54 | ||
55 | bool uncompress_blob(const void *src, uint64_t src_size, | |
93b73b06 | 56 | void **dst, uint64_t *dst_alloc_size, uint64_t* dst_size, uint64_t dst_max) { |
e4e61fdb LP |
57 | |
58 | lzma_stream s = LZMA_STREAM_INIT; | |
59 | lzma_ret ret; | |
93b73b06 | 60 | uint64_t space; |
e4e61fdb LP |
61 | bool b = false; |
62 | ||
63 | assert(src); | |
64 | assert(src_size > 0); | |
65 | assert(dst); | |
66 | assert(dst_alloc_size); | |
67 | assert(dst_size); | |
68 | assert(*dst_alloc_size == 0 || *dst); | |
69 | ||
70 | ret = lzma_stream_decoder(&s, UINT64_MAX, 0); | |
71 | if (ret != LZMA_OK) | |
72 | return false; | |
73 | ||
74 | if (*dst_alloc_size <= src_size) { | |
75 | void *p; | |
76 | ||
77 | p = realloc(*dst, src_size*2); | |
78 | if (!p) | |
79 | return false; | |
80 | ||
81 | *dst = p; | |
82 | *dst_alloc_size = src_size*2; | |
83 | } | |
84 | ||
85 | s.next_in = src; | |
86 | s.avail_in = src_size; | |
87 | ||
88 | s.next_out = *dst; | |
93b73b06 LP |
89 | space = dst_max > 0 ? MIN(*dst_alloc_size, dst_max) : *dst_alloc_size; |
90 | s.avail_out = space; | |
e4e61fdb LP |
91 | |
92 | for (;;) { | |
93 | void *p; | |
94 | ||
95 | ret = lzma_code(&s, LZMA_FINISH); | |
96 | ||
97 | if (ret == LZMA_STREAM_END) | |
98 | break; | |
99 | ||
100 | if (ret != LZMA_OK) | |
101 | goto fail; | |
102 | ||
93b73b06 LP |
103 | if (dst_max > 0 && (space - s.avail_out) >= dst_max) |
104 | break; | |
105 | ||
106 | p = realloc(*dst, space*2); | |
e4e61fdb LP |
107 | if (!p) |
108 | goto fail; | |
109 | ||
110 | s.next_out = (uint8_t*) p + ((uint8_t*) s.next_out - (uint8_t*) *dst); | |
93b73b06 LP |
111 | s.avail_out += space; |
112 | ||
113 | space *= 2; | |
e4e61fdb LP |
114 | |
115 | *dst = p; | |
93b73b06 | 116 | *dst_alloc_size = space; |
e4e61fdb LP |
117 | } |
118 | ||
93b73b06 | 119 | *dst_size = space - s.avail_out; |
e4e61fdb LP |
120 | b = true; |
121 | ||
122 | fail: | |
123 | lzma_end(&s); | |
124 | ||
125 | return b; | |
126 | } | |
127 | ||
128 | bool uncompress_startswith(const void *src, uint64_t src_size, | |
129 | void **buffer, uint64_t *buffer_size, | |
130 | const void *prefix, uint64_t prefix_len, | |
131 | uint8_t extra) { | |
132 | ||
133 | lzma_stream s = LZMA_STREAM_INIT; | |
134 | lzma_ret ret; | |
135 | bool b = false; | |
136 | ||
137 | /* Checks whether the uncompressed blob starts with the | |
138 | * mentioned prefix. The byte extra needs to follow the | |
139 | * prefix */ | |
140 | ||
141 | assert(src); | |
142 | assert(src_size > 0); | |
143 | assert(buffer); | |
144 | assert(buffer_size); | |
145 | assert(prefix); | |
146 | assert(*buffer_size == 0 || *buffer); | |
147 | ||
148 | ret = lzma_stream_decoder(&s, UINT64_MAX, 0); | |
149 | if (ret != LZMA_OK) | |
150 | return false; | |
151 | ||
152 | if (*buffer_size <= prefix_len) { | |
153 | void *p; | |
154 | ||
155 | p = realloc(*buffer, prefix_len*2); | |
156 | if (!p) | |
157 | return false; | |
158 | ||
159 | *buffer = p; | |
160 | *buffer_size = prefix_len*2; | |
161 | } | |
162 | ||
163 | s.next_in = src; | |
164 | s.avail_in = src_size; | |
165 | ||
166 | s.next_out = *buffer; | |
167 | s.avail_out = *buffer_size; | |
168 | ||
169 | for (;;) { | |
170 | void *p; | |
171 | ||
172 | ret = lzma_code(&s, LZMA_FINISH); | |
173 | ||
174 | if (ret != LZMA_STREAM_END && ret != LZMA_OK) | |
175 | goto fail; | |
176 | ||
177 | if ((*buffer_size - s.avail_out > prefix_len) && | |
178 | memcmp(*buffer, prefix, prefix_len) == 0 && | |
179 | ((const uint8_t*) *buffer)[prefix_len] == extra) | |
180 | break; | |
181 | ||
182 | if (ret == LZMA_STREAM_END) | |
183 | goto fail; | |
184 | ||
185 | p = realloc(*buffer, *buffer_size*2); | |
186 | if (!p) | |
187 | goto fail; | |
188 | ||
189 | s.next_out = (uint8_t*) p + ((uint8_t*) s.next_out - (uint8_t*) *buffer); | |
190 | s.avail_out += *buffer_size; | |
191 | ||
192 | *buffer = p; | |
193 | *buffer_size *= 2; | |
194 | } | |
195 | ||
196 | b = true; | |
197 | ||
198 | fail: | |
199 | lzma_end(&s); | |
200 | ||
201 | return b; | |
202 | } |