Commit | Line | Data |
---|---|---|
64c70b1c | 1 | /* |
8b975bd3 | 2 | * LZO1X Decompressor from LZO |
64c70b1c | 3 | * |
8b975bd3 | 4 | * Copyright (C) 1996-2012 Markus F.X.J. Oberhumer <markus@oberhumer.com> |
64c70b1c RP |
5 | * |
6 | * The full LZO package can be found at: | |
7 | * http://www.oberhumer.com/opensource/lzo/ | |
8 | * | |
8b975bd3 | 9 | * Changed for Linux kernel use by: |
64c70b1c RP |
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 | 17 | #endif |
64c70b1c | 18 | #include <asm/unaligned.h> |
7dd65feb | 19 | #include <linux/lzo.h> |
64c70b1c RP |
20 | #include "lzodefs.h" |
21 | ||
8b975bd3 MO |
22 | #define HAVE_IP(x) ((size_t)(ip_end - ip) >= (size_t)(x)) |
23 | #define HAVE_OP(x) ((size_t)(op_end - op) >= (size_t)(x)) | |
24 | #define NEED_IP(x) if (!HAVE_IP(x)) goto input_overrun | |
25 | #define NEED_OP(x) if (!HAVE_OP(x)) goto output_overrun | |
26 | #define TEST_LB(m_pos) if ((m_pos) < out) goto lookbehind_overrun | |
64c70b1c RP |
27 | |
28 | int lzo1x_decompress_safe(const unsigned char *in, size_t in_len, | |
8b975bd3 | 29 | unsigned char *out, size_t *out_len) |
64c70b1c | 30 | { |
8b975bd3 MO |
31 | unsigned char *op; |
32 | const unsigned char *ip; | |
33 | size_t t, next; | |
34 | size_t state = 0; | |
35 | const unsigned char *m_pos; | |
64c70b1c RP |
36 | const unsigned char * const ip_end = in + in_len; |
37 | unsigned char * const op_end = out + *out_len; | |
64c70b1c | 38 | |
8b975bd3 MO |
39 | op = out; |
40 | ip = in; | |
64c70b1c | 41 | |
8b975bd3 MO |
42 | if (unlikely(in_len < 3)) |
43 | goto input_overrun; | |
64c70b1c RP |
44 | if (*ip > 17) { |
45 | t = *ip++ - 17; | |
8b975bd3 MO |
46 | if (t < 4) { |
47 | next = t; | |
64c70b1c | 48 | goto match_next; |
64c70b1c | 49 | } |
8b975bd3 MO |
50 | goto copy_literal_run; |
51 | } | |
64c70b1c | 52 | |
8b975bd3 | 53 | for (;;) { |
64c70b1c | 54 | t = *ip++; |
8b975bd3 MO |
55 | if (t < 16) { |
56 | if (likely(state == 0)) { | |
57 | if (unlikely(t == 0)) { | |
58 | while (unlikely(*ip == 0)) { | |
64c70b1c RP |
59 | t += 255; |
60 | ip++; | |
8b975bd3 | 61 | NEED_IP(1); |
64c70b1c | 62 | } |
8b975bd3 | 63 | t += 15 + *ip++; |
64c70b1c | 64 | } |
8b975bd3 MO |
65 | t += 3; |
66 | copy_literal_run: | |
67 | #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) | |
68 | if (likely(HAVE_IP(t + 15) && HAVE_OP(t + 15))) { | |
69 | const unsigned char *ie = ip + t; | |
70 | unsigned char *oe = op + t; | |
71 | do { | |
72 | COPY8(op, ip); | |
73 | op += 8; | |
74 | ip += 8; | |
75 | COPY8(op, ip); | |
76 | op += 8; | |
77 | ip += 8; | |
78 | } while (ip < ie); | |
79 | ip = ie; | |
80 | op = oe; | |
81 | } else | |
82 | #endif | |
83 | { | |
84 | NEED_OP(t); | |
85 | NEED_IP(t + 3); | |
86 | do { | |
87 | *op++ = *ip++; | |
88 | } while (--t > 0); | |
64c70b1c | 89 | } |
8b975bd3 MO |
90 | state = 4; |
91 | continue; | |
92 | } else if (state != 4) { | |
93 | next = t & 3; | |
64c70b1c RP |
94 | m_pos = op - 1; |
95 | m_pos -= t >> 2; | |
96 | m_pos -= *ip++ << 2; | |
8b975bd3 MO |
97 | TEST_LB(m_pos); |
98 | NEED_OP(2); | |
99 | op[0] = m_pos[0]; | |
100 | op[1] = m_pos[1]; | |
101 | op += 2; | |
102 | goto match_next; | |
103 | } else { | |
104 | next = t & 3; | |
105 | m_pos = op - (1 + M2_MAX_OFFSET); | |
106 | m_pos -= t >> 2; | |
107 | m_pos -= *ip++ << 2; | |
108 | t = 3; | |
64c70b1c | 109 | } |
8b975bd3 MO |
110 | } else if (t >= 64) { |
111 | next = t & 3; | |
112 | m_pos = op - 1; | |
113 | m_pos -= (t >> 2) & 7; | |
114 | m_pos -= *ip++ << 3; | |
115 | t = (t >> 5) - 1 + (3 - 1); | |
116 | } else if (t >= 32) { | |
117 | t = (t & 31) + (3 - 1); | |
118 | if (unlikely(t == 2)) { | |
119 | while (unlikely(*ip == 0)) { | |
120 | t += 255; | |
121 | ip++; | |
122 | NEED_IP(1); | |
123 | } | |
124 | t += 31 + *ip++; | |
125 | NEED_IP(2); | |
126 | } | |
127 | m_pos = op - 1; | |
128 | next = get_unaligned_le16(ip); | |
129 | ip += 2; | |
130 | m_pos -= next >> 2; | |
131 | next &= 3; | |
132 | } else { | |
133 | m_pos = op; | |
134 | m_pos -= (t & 8) << 11; | |
135 | t = (t & 7) + (3 - 1); | |
136 | if (unlikely(t == 2)) { | |
137 | while (unlikely(*ip == 0)) { | |
138 | t += 255; | |
139 | ip++; | |
140 | NEED_IP(1); | |
141 | } | |
142 | t += 7 + *ip++; | |
143 | NEED_IP(2); | |
144 | } | |
145 | next = get_unaligned_le16(ip); | |
146 | ip += 2; | |
147 | m_pos -= next >> 2; | |
148 | next &= 3; | |
149 | if (m_pos == op) | |
150 | goto eof_found; | |
151 | m_pos -= 0x4000; | |
152 | } | |
153 | TEST_LB(m_pos); | |
154 | #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) | |
155 | if (op - m_pos >= 8) { | |
156 | unsigned char *oe = op + t; | |
157 | if (likely(HAVE_OP(t + 15))) { | |
64c70b1c | 158 | do { |
8b975bd3 MO |
159 | COPY8(op, m_pos); |
160 | op += 8; | |
161 | m_pos += 8; | |
162 | COPY8(op, m_pos); | |
163 | op += 8; | |
164 | m_pos += 8; | |
165 | } while (op < oe); | |
166 | op = oe; | |
167 | if (HAVE_IP(6)) { | |
168 | state = next; | |
169 | COPY4(op, ip); | |
170 | op += next; | |
171 | ip += next; | |
172 | continue; | |
173 | } | |
64c70b1c | 174 | } else { |
8b975bd3 | 175 | NEED_OP(t); |
64c70b1c RP |
176 | do { |
177 | *op++ = *m_pos++; | |
8b975bd3 | 178 | } while (op < oe); |
64c70b1c | 179 | } |
8b975bd3 MO |
180 | } else |
181 | #endif | |
182 | { | |
183 | unsigned char *oe = op + t; | |
184 | NEED_OP(t); | |
185 | op[0] = m_pos[0]; | |
186 | op[1] = m_pos[1]; | |
187 | op += 2; | |
188 | m_pos += 2; | |
189 | do { | |
190 | *op++ = *m_pos++; | |
191 | } while (op < oe); | |
192 | } | |
64c70b1c | 193 | match_next: |
8b975bd3 MO |
194 | state = next; |
195 | t = next; | |
196 | #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) | |
197 | if (likely(HAVE_IP(6) && HAVE_OP(4))) { | |
198 | COPY4(op, ip); | |
199 | op += t; | |
200 | ip += t; | |
201 | } else | |
202 | #endif | |
203 | { | |
204 | NEED_IP(t + 3); | |
205 | NEED_OP(t); | |
206 | while (t > 0) { | |
64c70b1c | 207 | *op++ = *ip++; |
8b975bd3 | 208 | t--; |
64c70b1c | 209 | } |
8b975bd3 | 210 | } |
64c70b1c RP |
211 | } |
212 | ||
64c70b1c RP |
213 | eof_found: |
214 | *out_len = op - out; | |
8b975bd3 MO |
215 | return (t != 3 ? LZO_E_ERROR : |
216 | ip == ip_end ? LZO_E_OK : | |
217 | ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN); | |
218 | ||
64c70b1c RP |
219 | input_overrun: |
220 | *out_len = op - out; | |
221 | return LZO_E_INPUT_OVERRUN; | |
222 | ||
223 | output_overrun: | |
224 | *out_len = op - out; | |
225 | return LZO_E_OUTPUT_OVERRUN; | |
226 | ||
227 | lookbehind_overrun: | |
228 | *out_len = op - out; | |
229 | return LZO_E_LOOKBEHIND_OVERRUN; | |
230 | } | |
7dd65feb | 231 | #ifndef STATIC |
64c70b1c RP |
232 | EXPORT_SYMBOL_GPL(lzo1x_decompress_safe); |
233 | ||
234 | MODULE_LICENSE("GPL"); | |
235 | MODULE_DESCRIPTION("LZO1X Decompressor"); | |
236 | ||
7dd65feb | 237 | #endif |