]>
Commit | Line | Data |
---|---|---|
bbe45369 | 1 | /* udis86 - libudis86/input.c |
2 | * | |
3 | * Copyright (c) 2002-2009 Vivek Thampi | |
4 | * All rights reserved. | |
5 | * | |
6 | * Redistribution and use in source and binary forms, with or without modification, | |
7 | * are permitted provided that the following conditions are met: | |
8 | * | |
9 | * * Redistributions of source code must retain the above copyright notice, | |
10 | * this list of conditions and the following disclaimer. | |
11 | * * Redistributions in binary form must reproduce the above copyright notice, | |
12 | * this list of conditions and the following disclaimer in the documentation | |
13 | * and/or other materials provided with the distribution. | |
14 | * | |
15 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND | |
16 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED | |
17 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
18 | * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR | |
19 | * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | |
20 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |
21 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON | |
22 | * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
23 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | |
24 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
25 | */ | |
26 | #include "extern.h" | |
27 | #include "types.h" | |
28 | #include "input.h" | |
29 | ||
30 | /* ----------------------------------------------------------------------------- | |
31 | * inp_buff_hook() - Hook for buffered inputs. | |
32 | * ----------------------------------------------------------------------------- | |
33 | */ | |
34 | static int | |
35 | inp_buff_hook(struct ud* u) | |
36 | { | |
37 | if (u->inp_buff < u->inp_buff_end) | |
38 | return *u->inp_buff++; | |
39 | else return -1; | |
40 | } | |
41 | ||
42 | #ifndef __UD_STANDALONE__ | |
43 | /* ----------------------------------------------------------------------------- | |
44 | * inp_file_hook() - Hook for FILE inputs. | |
45 | * ----------------------------------------------------------------------------- | |
46 | */ | |
47 | static int | |
48 | inp_file_hook(struct ud* u) | |
49 | { | |
50 | return fgetc(u->inp_file); | |
51 | } | |
52 | #endif /* __UD_STANDALONE__*/ | |
53 | ||
54 | /* ============================================================================= | |
55 | * ud_inp_set_hook() - Sets input hook. | |
56 | * ============================================================================= | |
57 | */ | |
58 | extern void | |
59 | ud_set_input_hook(register struct ud* u, int (*hook)(struct ud*)) | |
60 | { | |
61 | u->inp_hook = hook; | |
62 | inp_init(u); | |
63 | } | |
64 | ||
65 | extern void | |
66 | ud_set_user_opaque_data( struct ud * u, void * opaque ) | |
67 | { | |
68 | u->user_opaque_data = opaque; | |
69 | } | |
70 | ||
71 | extern void * | |
72 | ud_get_user_opaque_data( struct ud * u ) | |
73 | { | |
74 | return u->user_opaque_data; | |
75 | } | |
76 | ||
77 | /* ============================================================================= | |
78 | * ud_inp_set_buffer() - Set buffer as input. | |
79 | * ============================================================================= | |
80 | */ | |
81 | extern void | |
82 | ud_set_input_buffer(register struct ud* u, uint8_t* buf, size_t len) | |
83 | { | |
84 | u->inp_hook = inp_buff_hook; | |
85 | u->inp_buff = buf; | |
86 | u->inp_buff_end = buf + len; | |
87 | inp_init(u); | |
88 | } | |
89 | ||
90 | #ifndef __UD_STANDALONE__ | |
91 | /* ============================================================================= | |
92 | * ud_input_set_file() - Set buffer as input. | |
93 | * ============================================================================= | |
94 | */ | |
95 | extern void | |
96 | ud_set_input_file(register struct ud* u, FILE* f) | |
97 | { | |
98 | u->inp_hook = inp_file_hook; | |
99 | u->inp_file = f; | |
100 | inp_init(u); | |
101 | } | |
102 | #endif /* __UD_STANDALONE__ */ | |
103 | ||
104 | /* ============================================================================= | |
105 | * ud_input_skip() - Skip n input bytes. | |
106 | * ============================================================================= | |
107 | */ | |
108 | extern void | |
109 | ud_input_skip(struct ud* u, size_t n) | |
110 | { | |
111 | while (n--) { | |
112 | u->inp_hook(u); | |
113 | } | |
114 | } | |
115 | ||
116 | /* ============================================================================= | |
117 | * ud_input_end() - Test for end of input. | |
118 | * ============================================================================= | |
119 | */ | |
120 | extern int | |
121 | ud_input_end(struct ud* u) | |
122 | { | |
123 | return (u->inp_curr == u->inp_fill) && u->inp_end; | |
124 | } | |
125 | ||
126 | /* ----------------------------------------------------------------------------- | |
127 | * inp_next() - Loads and returns the next byte from input. | |
128 | * | |
129 | * inp_curr and inp_fill are pointers to the cache. The program is written based | |
130 | * on the property that they are 8-bits in size, and will eventually wrap around | |
131 | * forming a circular buffer. So, the size of the cache is 256 in size, kind of | |
132 | * unnecessary yet optimized. | |
133 | * | |
134 | * A buffer inp_sess stores the bytes disassembled for a single session. | |
135 | * ----------------------------------------------------------------------------- | |
136 | */ | |
137 | extern uint8_t inp_next(struct ud* u) | |
138 | { | |
139 | int c = -1; | |
140 | /* if current pointer is not upto the fill point in the | |
141 | * input cache. | |
142 | */ | |
143 | if ( u->inp_curr != u->inp_fill ) { | |
144 | c = u->inp_cache[ ++u->inp_curr ]; | |
145 | /* if !end-of-input, call the input hook and get a byte */ | |
146 | } else if ( u->inp_end || ( c = u->inp_hook( u ) ) == -1 ) { | |
147 | /* end-of-input, mark it as an error, since the decoder, | |
148 | * expected a byte more. | |
149 | */ | |
150 | u->error = 1; | |
151 | /* flag end of input */ | |
152 | u->inp_end = 1; | |
153 | return 0; | |
154 | } else { | |
155 | /* increment pointers, we have a new byte. */ | |
156 | u->inp_curr = ++u->inp_fill; | |
157 | /* add the byte to the cache */ | |
158 | u->inp_cache[ u->inp_fill ] = c; | |
159 | } | |
160 | /* record bytes input per decode-session. */ | |
161 | u->inp_sess[ u->inp_ctr++ ] = c; | |
162 | /* return byte */ | |
163 | return ( uint8_t ) c; | |
164 | } | |
165 | ||
166 | /* ----------------------------------------------------------------------------- | |
167 | * inp_back() - Move back a single byte in the stream. | |
168 | * ----------------------------------------------------------------------------- | |
169 | */ | |
170 | extern void | |
171 | inp_back(struct ud* u) | |
172 | { | |
173 | if ( u->inp_ctr > 0 ) { | |
174 | --u->inp_curr; | |
175 | --u->inp_ctr; | |
176 | } | |
177 | } | |
178 | ||
179 | /* ----------------------------------------------------------------------------- | |
180 | * inp_peek() - Peek into the next byte in source. | |
181 | * ----------------------------------------------------------------------------- | |
182 | */ | |
183 | extern uint8_t | |
184 | inp_peek(struct ud* u) | |
185 | { | |
186 | uint8_t r = inp_next(u); | |
187 | if ( !u->error ) inp_back(u); /* Don't backup if there was an error */ | |
188 | return r; | |
189 | } | |
190 | ||
191 | /* ----------------------------------------------------------------------------- | |
192 | * inp_move() - Move ahead n input bytes. | |
193 | * ----------------------------------------------------------------------------- | |
194 | */ | |
195 | extern void | |
196 | inp_move(struct ud* u, size_t n) | |
197 | { | |
198 | while (n--) | |
199 | inp_next(u); | |
200 | } | |
201 | ||
202 | /*------------------------------------------------------------------------------ | |
203 | * inp_uintN() - return uintN from source. | |
204 | *------------------------------------------------------------------------------ | |
205 | */ | |
206 | extern uint8_t | |
207 | inp_uint8(struct ud* u) | |
208 | { | |
209 | return inp_next(u); | |
210 | } | |
211 | ||
212 | extern uint16_t | |
213 | inp_uint16(struct ud* u) | |
214 | { | |
215 | uint16_t r, ret; | |
216 | ||
217 | ret = inp_next(u); | |
218 | r = inp_next(u); | |
219 | return ret | (r << 8); | |
220 | } | |
221 | ||
222 | extern uint32_t | |
223 | inp_uint32(struct ud* u) | |
224 | { | |
225 | uint32_t r, ret; | |
226 | ||
227 | ret = inp_next(u); | |
228 | r = inp_next(u); | |
229 | ret = ret | (r << 8); | |
230 | r = inp_next(u); | |
231 | ret = ret | (r << 16); | |
232 | r = inp_next(u); | |
233 | return ret | (r << 24); | |
234 | } | |
235 | ||
236 | extern uint64_t | |
237 | inp_uint64(struct ud* u) | |
238 | { | |
239 | uint64_t r, ret; | |
240 | ||
241 | ret = inp_next(u); | |
242 | r = inp_next(u); | |
243 | ret = ret | (r << 8); | |
244 | r = inp_next(u); | |
245 | ret = ret | (r << 16); | |
246 | r = inp_next(u); | |
247 | ret = ret | (r << 24); | |
248 | r = inp_next(u); | |
249 | ret = ret | (r << 32); | |
250 | r = inp_next(u); | |
251 | ret = ret | (r << 40); | |
252 | r = inp_next(u); | |
253 | ret = ret | (r << 48); | |
254 | r = inp_next(u); | |
255 | return ret | (r << 56); | |
256 | } |