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-rw-r--r--lib/lzo/lzo1x_decompress.c254
1 files changed, 254 insertions, 0 deletions
diff --git a/lib/lzo/lzo1x_decompress.c b/lib/lzo/lzo1x_decompress.c
new file mode 100644
index 000000000000..9dc7056e5520
--- /dev/null
+++ b/lib/lzo/lzo1x_decompress.c
@@ -0,0 +1,254 @@
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
14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/lzo.h>
17#include <asm/byteorder.h>
18#include <asm/unaligned.h>
19#include "lzodefs.h"
20
21#define HAVE_IP(x, ip_end, ip) ((size_t)(ip_end - ip) < (x))
22#define HAVE_OP(x, op_end, op) ((size_t)(op_end - op) < (x))
23#define HAVE_LB(m_pos, out, op) (m_pos < out || m_pos >= op)
24
25#define COPY4(dst, src) \
26 put_unaligned(get_unaligned((const u32 *)(src)), (u32 *)(dst))
27
28int lzo1x_decompress_safe(const unsigned char *in, size_t in_len,
29 unsigned char *out, size_t *out_len)
30{
31 const unsigned char * const ip_end = in + in_len;
32 unsigned char * const op_end = out + *out_len;
33 const unsigned char *ip = in, *m_pos;
34 unsigned char *op = out;
35 size_t t;
36
37 *out_len = 0;
38
39 if (*ip > 17) {
40 t = *ip++ - 17;
41 if (t < 4)
42 goto match_next;
43 if (HAVE_OP(t, op_end, op))
44 goto output_overrun;
45 if (HAVE_IP(t + 1, ip_end, ip))
46 goto input_overrun;
47 do {
48 *op++ = *ip++;
49 } while (--t > 0);
50 goto first_literal_run;
51 }
52
53 while ((ip < ip_end)) {
54 t = *ip++;
55 if (t >= 16)
56 goto match;
57 if (t == 0) {
58 if (HAVE_IP(1, ip_end, ip))
59 goto input_overrun;
60 while (*ip == 0) {
61 t += 255;
62 ip++;
63 if (HAVE_IP(1, ip_end, ip))
64 goto input_overrun;
65 }
66 t += 15 + *ip++;
67 }
68 if (HAVE_OP(t + 3, op_end, op))
69 goto output_overrun;
70 if (HAVE_IP(t + 4, ip_end, ip))
71 goto input_overrun;
72
73 COPY4(op, ip);
74 op += 4;
75 ip += 4;
76 if (--t > 0) {
77 if (t >= 4) {
78 do {
79 COPY4(op, ip);
80 op += 4;
81 ip += 4;
82 t -= 4;
83 } while (t >= 4);
84 if (t > 0) {
85 do {
86 *op++ = *ip++;
87 } while (--t > 0);
88 }
89 } else {
90 do {
91 *op++ = *ip++;
92 } while (--t > 0);
93 }
94 }
95
96first_literal_run:
97 t = *ip++;
98 if (t >= 16)
99 goto match;
100 m_pos = op - (1 + M2_MAX_OFFSET);
101 m_pos -= t >> 2;
102 m_pos -= *ip++ << 2;
103
104 if (HAVE_LB(m_pos, out, op))
105 goto lookbehind_overrun;
106
107 if (HAVE_OP(3, op_end, op))
108 goto output_overrun;
109 *op++ = *m_pos++;
110 *op++ = *m_pos++;
111 *op++ = *m_pos;
112
113 goto match_done;
114
115 do {
116match:
117 if (t >= 64) {
118 m_pos = op - 1;
119 m_pos -= (t >> 2) & 7;
120 m_pos -= *ip++ << 3;
121 t = (t >> 5) - 1;
122 if (HAVE_LB(m_pos, out, op))
123 goto lookbehind_overrun;
124 if (HAVE_OP(t + 3 - 1, op_end, op))
125 goto output_overrun;
126 goto copy_match;
127 } else if (t >= 32) {
128 t &= 31;
129 if (t == 0) {
130 if (HAVE_IP(1, ip_end, ip))
131 goto input_overrun;
132 while (*ip == 0) {
133 t += 255;
134 ip++;
135 if (HAVE_IP(1, ip_end, ip))
136 goto input_overrun;
137 }
138 t += 31 + *ip++;
139 }
140 m_pos = op - 1;
141 m_pos -= le16_to_cpu(get_unaligned(
142 (const unsigned short *)ip)) >> 2;
143 ip += 2;
144 } else if (t >= 16) {
145 m_pos = op;
146 m_pos -= (t & 8) << 11;
147
148 t &= 7;
149 if (t == 0) {
150 if (HAVE_IP(1, ip_end, ip))
151 goto input_overrun;
152 while (*ip == 0) {
153 t += 255;
154 ip++;
155 if (HAVE_IP(1, ip_end, ip))
156 goto input_overrun;
157 }
158 t += 7 + *ip++;
159 }
160 m_pos -= le16_to_cpu(get_unaligned(
161 (const unsigned short *)ip) >> 2);
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 {
202copy_match:
203 *op++ = *m_pos++;
204 *op++ = *m_pos++;
205 do {
206 *op++ = *m_pos++;
207 } while (--t > 0);
208 }
209match_done:
210 t = ip[-2] & 3;
211 if (t == 0)
212 break;
213match_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
233eof_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));
237input_overrun:
238 *out_len = op - out;
239 return LZO_E_INPUT_OVERRUN;
240
241output_overrun:
242 *out_len = op - out;
243 return LZO_E_OUTPUT_OVERRUN;
244
245lookbehind_overrun:
246 *out_len = op - out;
247 return LZO_E_LOOKBEHIND_OVERRUN;
248}
249
250EXPORT_SYMBOL_GPL(lzo1x_decompress_safe);
251
252MODULE_LICENSE("GPL");
253MODULE_DESCRIPTION("LZO1X Decompressor");
254
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-25 00:57:46 -0500