Commit | Line | Data |
---|---|---|
64c70b1c RP |
1 | /* |
2 | * LZO1X Decompressor from MiniLZO | |
3 | * | |
4 | * Copyright (C) 1996-2005 Markus F.X.J. Oberhumer <markus@oberhumer.com> | |
5 | * | |
6 | * The full LZO package can be found at: | |
7 | * http://www.oberhumer.com/opensource/lzo/ | |
8 | * | |
9 | * Changed for kernel use by: | |
10 | * Nitin Gupta <nitingupta910@gmail.com> | |
11 | * Richard Purdie <rpurdie@openedhand.com> | |
12 | */ | |
13 | ||
7dd65feb | 14 | #ifndef STATIC |
64c70b1c RP |
15 | #include <linux/module.h> |
16 | #include <linux/kernel.h> | |
7dd65feb AT |
17 | #endif |
18 | ||
64c70b1c | 19 | #include <asm/unaligned.h> |
7dd65feb | 20 | #include <linux/lzo.h> |
64c70b1c RP |
21 | #include "lzodefs.h" |
22 | ||
23 | #define HAVE_IP(x, ip_end, ip) ((size_t)(ip_end - ip) < (x)) | |
24 | #define HAVE_OP(x, op_end, op) ((size_t)(op_end - op) < (x)) | |
25 | #define HAVE_LB(m_pos, out, op) (m_pos < out || m_pos >= op) | |
26 | ||
27 | #define COPY4(dst, src) \ | |
28 | put_unaligned(get_unaligned((const u32 *)(src)), (u32 *)(dst)) | |
29 | ||
30 | int lzo1x_decompress_safe(const unsigned char *in, size_t in_len, | |
31 | unsigned char *out, size_t *out_len) | |
32 | { | |
33 | const unsigned char * const ip_end = in + in_len; | |
34 | unsigned char * const op_end = out + *out_len; | |
35 | const unsigned char *ip = in, *m_pos; | |
36 | unsigned char *op = out; | |
37 | size_t t; | |
38 | ||
39 | *out_len = 0; | |
40 | ||
41 | if (*ip > 17) { | |
42 | t = *ip++ - 17; | |
43 | if (t < 4) | |
44 | goto match_next; | |
45 | if (HAVE_OP(t, op_end, op)) | |
46 | goto output_overrun; | |
47 | if (HAVE_IP(t + 1, ip_end, ip)) | |
48 | goto input_overrun; | |
49 | do { | |
50 | *op++ = *ip++; | |
51 | } while (--t > 0); | |
52 | goto first_literal_run; | |
53 | } | |
54 | ||
55 | while ((ip < ip_end)) { | |
56 | t = *ip++; | |
57 | if (t >= 16) | |
58 | goto match; | |
59 | if (t == 0) { | |
60 | if (HAVE_IP(1, ip_end, ip)) | |
61 | goto input_overrun; | |
62 | while (*ip == 0) { | |
63 | t += 255; | |
64 | ip++; | |
65 | if (HAVE_IP(1, ip_end, ip)) | |
66 | goto input_overrun; | |
67 | } | |
68 | t += 15 + *ip++; | |
69 | } | |
70 | if (HAVE_OP(t + 3, op_end, op)) | |
71 | goto output_overrun; | |
72 | if (HAVE_IP(t + 4, ip_end, ip)) | |
73 | goto input_overrun; | |
74 | ||
75 | COPY4(op, ip); | |
76 | op += 4; | |
77 | ip += 4; | |
78 | if (--t > 0) { | |
79 | if (t >= 4) { | |
80 | do { | |
81 | COPY4(op, ip); | |
82 | op += 4; | |
83 | ip += 4; | |
84 | t -= 4; | |
85 | } while (t >= 4); | |
86 | if (t > 0) { | |
87 | do { | |
88 | *op++ = *ip++; | |
89 | } while (--t > 0); | |
90 | } | |
91 | } else { | |
92 | do { | |
93 | *op++ = *ip++; | |
94 | } while (--t > 0); | |
95 | } | |
96 | } | |
97 | ||
98 | first_literal_run: | |
99 | t = *ip++; | |
100 | if (t >= 16) | |
101 | goto match; | |
102 | m_pos = op - (1 + M2_MAX_OFFSET); | |
103 | m_pos -= t >> 2; | |
104 | m_pos -= *ip++ << 2; | |
105 | ||
106 | if (HAVE_LB(m_pos, out, op)) | |
107 | goto lookbehind_overrun; | |
108 | ||
109 | if (HAVE_OP(3, op_end, op)) | |
110 | goto output_overrun; | |
111 | *op++ = *m_pos++; | |
112 | *op++ = *m_pos++; | |
113 | *op++ = *m_pos; | |
114 | ||
115 | goto match_done; | |
116 | ||
117 | do { | |
118 | match: | |
119 | if (t >= 64) { | |
120 | m_pos = op - 1; | |
121 | m_pos -= (t >> 2) & 7; | |
122 | m_pos -= *ip++ << 3; | |
123 | t = (t >> 5) - 1; | |
124 | if (HAVE_LB(m_pos, out, op)) | |
125 | goto lookbehind_overrun; | |
126 | if (HAVE_OP(t + 3 - 1, op_end, op)) | |
127 | goto output_overrun; | |
128 | goto copy_match; | |
129 | } else if (t >= 32) { | |
130 | t &= 31; | |
131 | if (t == 0) { | |
132 | if (HAVE_IP(1, ip_end, ip)) | |
133 | goto input_overrun; | |
134 | while (*ip == 0) { | |
135 | t += 255; | |
136 | ip++; | |
137 | if (HAVE_IP(1, ip_end, ip)) | |
138 | goto input_overrun; | |
139 | } | |
140 | t += 31 + *ip++; | |
141 | } | |
142 | m_pos = op - 1; | |
545e4006 | 143 | m_pos -= get_unaligned_le16(ip) >> 2; |
64c70b1c RP |
144 | ip += 2; |
145 | } else if (t >= 16) { | |
146 | m_pos = op; | |
147 | m_pos -= (t & 8) << 11; | |
148 | ||
149 | t &= 7; | |
150 | if (t == 0) { | |
151 | if (HAVE_IP(1, ip_end, ip)) | |
152 | goto input_overrun; | |
153 | while (*ip == 0) { | |
154 | t += 255; | |
155 | ip++; | |
156 | if (HAVE_IP(1, ip_end, ip)) | |
157 | goto input_overrun; | |
158 | } | |
159 | t += 7 + *ip++; | |
160 | } | |
545e4006 | 161 | m_pos -= get_unaligned_le16(ip) >> 2; |
64c70b1c RP |
162 | ip += 2; |
163 | if (m_pos == op) | |
164 | goto eof_found; | |
165 | m_pos -= 0x4000; | |
166 | } else { | |
167 | m_pos = op - 1; | |
168 | m_pos -= t >> 2; | |
169 | m_pos -= *ip++ << 2; | |
170 | ||
171 | if (HAVE_LB(m_pos, out, op)) | |
172 | goto lookbehind_overrun; | |
173 | if (HAVE_OP(2, op_end, op)) | |
174 | goto output_overrun; | |
175 | ||
176 | *op++ = *m_pos++; | |
177 | *op++ = *m_pos; | |
178 | goto match_done; | |
179 | } | |
180 | ||
181 | if (HAVE_LB(m_pos, out, op)) | |
182 | goto lookbehind_overrun; | |
183 | if (HAVE_OP(t + 3 - 1, op_end, op)) | |
184 | goto output_overrun; | |
185 | ||
186 | if (t >= 2 * 4 - (3 - 1) && (op - m_pos) >= 4) { | |
187 | COPY4(op, m_pos); | |
188 | op += 4; | |
189 | m_pos += 4; | |
190 | t -= 4 - (3 - 1); | |
191 | do { | |
192 | COPY4(op, m_pos); | |
193 | op += 4; | |
194 | m_pos += 4; | |
195 | t -= 4; | |
196 | } while (t >= 4); | |
197 | if (t > 0) | |
198 | do { | |
199 | *op++ = *m_pos++; | |
200 | } while (--t > 0); | |
201 | } else { | |
202 | copy_match: | |
203 | *op++ = *m_pos++; | |
204 | *op++ = *m_pos++; | |
205 | do { | |
206 | *op++ = *m_pos++; | |
207 | } while (--t > 0); | |
208 | } | |
209 | match_done: | |
210 | t = ip[-2] & 3; | |
211 | if (t == 0) | |
212 | break; | |
213 | match_next: | |
214 | if (HAVE_OP(t, op_end, op)) | |
215 | goto output_overrun; | |
216 | if (HAVE_IP(t + 1, ip_end, ip)) | |
217 | goto input_overrun; | |
218 | ||
219 | *op++ = *ip++; | |
220 | if (t > 1) { | |
221 | *op++ = *ip++; | |
222 | if (t > 2) | |
223 | *op++ = *ip++; | |
224 | } | |
225 | ||
226 | t = *ip++; | |
227 | } while (ip < ip_end); | |
228 | } | |
229 | ||
230 | *out_len = op - out; | |
231 | return LZO_E_EOF_NOT_FOUND; | |
232 | ||
233 | eof_found: | |
234 | *out_len = op - out; | |
235 | return (ip == ip_end ? LZO_E_OK : | |
236 | (ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN)); | |
237 | input_overrun: | |
238 | *out_len = op - out; | |
239 | return LZO_E_INPUT_OVERRUN; | |
240 | ||
241 | output_overrun: | |
242 | *out_len = op - out; | |
243 | return LZO_E_OUTPUT_OVERRUN; | |
244 | ||
245 | lookbehind_overrun: | |
246 | *out_len = op - out; | |
247 | return LZO_E_LOOKBEHIND_OVERRUN; | |
248 | } | |
7dd65feb | 249 | #ifndef STATIC |
64c70b1c RP |
250 | EXPORT_SYMBOL_GPL(lzo1x_decompress_safe); |
251 | ||
252 | MODULE_LICENSE("GPL"); | |
253 | MODULE_DESCRIPTION("LZO1X Decompressor"); | |
254 | ||
7dd65feb | 255 | #endif |