1
2 /*--------------------------------------------------------------------*/
3 /*--- An abstraction that provides a file-reading mechanism. ---*/
4 /*--- priv_image.h ---*/
5 /*--------------------------------------------------------------------*/
6
7 /*
8 This file is part of Valgrind, a dynamic binary instrumentation
9 framework.
10
11 Copyright (C) 2013-2013 Mozilla Foundation
12
13 This program is free software; you can redistribute it and/or
14 modify it under the terms of the GNU General Public License as
15 published by the Free Software Foundation; either version 2 of the
16 License, or (at your option) any later version.
17
18 This program is distributed in the hope that it will be useful, but
19 WITHOUT ANY WARRANTY; without even the implied warranty of
20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 General Public License for more details.
22
23 You should have received a copy of the GNU General Public License
24 along with this program; if not, write to the Free Software
25 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
26 02111-1307, USA.
27
28 The GNU General Public License is contained in the file COPYING.
29 */
30
31 /* Contributed by Julian Seward <jseward@acm.org> */
32
33 #ifndef __PRIV_IMAGE_H
34 #define __PRIV_IMAGE_H
35
36 #include "pub_core_basics.h" // ULong
37 #include "priv_misc.h" // ML_(dinfo_zalloc)
38
39 /*------------------------------------------------------------*/
40 /*--- DiImage -- abstract images ---*/
41 /*------------------------------------------------------------*/
42
43 /* The basic type, containing an abstractified memory area that can be
44 read from. This is an abstract type since there can be more than
45 one implementation of it. */
46
47 /* abstract */
48 typedef struct _DiImage DiImage;
49
50 /* an offset in the image */
51 typedef ULong DiOffT;
52
53 /* This denotes an invalid DiOffT value. Except where otherwise
54 noted, you must never pass this to any of the ML_(image_*)
55 functions -- they will assert. That does mean though that they can
56 be used for signalling other conditions, for example that some
57 expected part of the image is missing. */
58 #define DiOffT_INVALID ((DiOffT)(0xFFFFFFFFFFFFFFFFULL))
59
60 /* Create an image from a file in the local filesysem. Returns NULL
61 if it fails, for whatever reason. */
62 DiImage* ML_(img_from_local_file)(const HChar* fullpath);
63
64 /* Create an image by connecting to a Valgrind debuginfo server
65 (auxprogs/valgrind-di-server.c). |filename| contains the object
66 name to ask for; it must be a plain filename, not absolute, not a
67 path. |serverAddr| must be of the form either "d.d.d.d" or
68 "d.d.d.d:d" where d is one or more digits. These specify the IPv4
69 address and (in the second case) port number for the server. In
70 the first case, port 1500 is assumed. */
71 DiImage* ML_(img_from_di_server)(const HChar* filename,
72 const HChar* serverAddr);
73
74 /* Destroy an existing image. */
75 void ML_(img_done)(DiImage*);
76
77 /* How big is the image? */
78 DiOffT ML_(img_size)(DiImage* img);
79
80 /* Does the section [offset, +size) exist in the image? */
81 Bool ML_(img_valid)(DiImage* img, DiOffT offset, SizeT size);
82
83 /* Get info out of an image. If any part of the section denoted by
84 [offset, +size) is invalid, does not return. */
85 void ML_(img_get)(/*OUT*/void* dst,
86 DiImage* img, DiOffT offset, SizeT size);
87
88 /* A version of ML_(img_get) that is significantly cheaper when
89 fetching a lot of data, at the cost of being more difficult to use.
90 Fetches between 1 and |size| bytes from |img| at |offset| and
91 places them in |dst|. |size| must be at least 1. The number of
92 bytes read is returned, and the caller must be able to deal with
93 any number between 1 and |size|. |offset| must be a valid offset
94 in the image; if not the function will not return. This function
95 will not read off the end of the image. */
96 SizeT ML_(img_get_some)(/*OUT*/void* dst,
97 DiImage* img, DiOffT offset, SizeT size);
98
99 /* Copy a C string out of the image, into ML_(dinfo_zalloc)'d space.
100 The caller owns the string and must free it with ML_(dinfo_free).
101 |offset| may be DiOffT_INVALID, in which case this returns NULL. */
102 HChar* ML_(img_strdup)(DiImage* img, const HChar* cc, DiOffT offset);
103
104 /* Do strcmp on two C strings in the image. Chars are cast to HChar
105 before comparison. */
106 Int ML_(img_strcmp)(DiImage* img, DiOffT off1, DiOffT off2);
107
108 /* Do strcmp of a C string in the image vs a normal one. Chars are
109 cast to HChar before comparison. */
110 Int ML_(img_strcmp_c)(DiImage* img, DiOffT off1, const HChar* str2);
111
112 /* Do strlen of a C string in the image. */
113 SizeT ML_(img_strlen)(DiImage* img, DiOffT off);
114
115 /* Fetch various sized primitive types from the image. These operate
116 at the endianness and word size of the host. */
117 UChar ML_(img_get_UChar) (DiImage* img, DiOffT offset);
118 UShort ML_(img_get_UShort)(DiImage* img, DiOffT offset);
119 UInt ML_(img_get_UInt) (DiImage* img, DiOffT offset);
120 ULong ML_(img_get_ULong) (DiImage* img, DiOffT offset);
121
122 /* Calculate the "GNU Debuglink CRC" for the image. This
123 unfortunately has to be done as part of the DiImage implementation
124 because it involves reading the entire image, and is therefore
125 something that needs to be handed off to the remote server -- since
126 to do it otherwise would imply pulling the entire image across the
127 connection, making the client/server split pointless. */
128 UInt ML_(img_calc_gnu_debuglink_crc32)(DiImage* img);
129
130
131 /*------------------------------------------------------------*/
132 /*--- DiCursor -- cursors for reading images ---*/
133 /*------------------------------------------------------------*/
134
135 /* A type built on DiImage. It contains a DiImage and a 'current
136 offset' in the image, and is useful for building low level readers
137 of images. In the functions section below, "read" means "read data
138 at the cursor without moving it along", and "step" means "read data
139 at the cursor and move it along by the size of the item read". */
140 typedef
141 struct { DiImage* img; DiOffT ioff; }
142 DiCursor;
143
144 /* An invalid cursor. You can't use it for anything. */
145 #define DiCursor_INVALID ((DiCursor){NULL,DiOffT_INVALID})
146
mk_DiCursor(DiImage * img,DiOffT ioff)147 static inline DiCursor mk_DiCursor ( DiImage* img, DiOffT ioff ) {
148 return (DiCursor){img, ioff};
149 }
150
ML_(cur_is_valid)151 static inline Bool ML_(cur_is_valid)(DiCursor c) {
152 return c.img != NULL;
153 }
154
155
156 /*------------------------------------------------------------*/
157 /*--- DiSlice -- subranges within DiImages ---*/
158 /*------------------------------------------------------------*/
159
160 /* Another type built on top of DiImage. It denotes a subrange of an
161 image and is useful for representing (eg) exactly the part of an
162 image that is a specific ELF section. */
163 typedef
164 struct { DiImage* img; DiOffT ioff; DiOffT szB; }
165 DiSlice;
166
167 /* A DiSlice can also be INVALID, meaning it does not refer to any
168 part of any image. */
169 #define DiSlice_INVALID ((DiSlice){NULL,DiOffT_INVALID,0})
170
mk_DiSlice(DiImage * img,DiOffT ioff,DiOffT szB)171 static inline DiSlice mk_DiSlice ( DiImage* img, DiOffT ioff, DiOffT szB ) {
172 return (DiSlice){img, ioff, szB};
173 }
174
ML_(sli_is_valid)175 static inline Bool ML_(sli_is_valid)( DiSlice sli ) {
176 return sli.img != NULL;
177 }
178
179 /* Create a slice from a combination of a cursor and a length. The
180 maximum implied offset must not exceed the size of the underlying
181 image; this is asserted for. */
ML_(sli_from_cur)182 static inline DiSlice ML_(sli_from_cur)( DiCursor cur, DiOffT size ) {
183 if (ML_(cur_is_valid)(cur)) {
184 vg_assert(size != DiOffT_INVALID);
185 vg_assert(cur.ioff + size <= ML_(img_size)(cur.img));
186 return mk_DiSlice(cur.img, cur.ioff, size);
187 } else {
188 return DiSlice_INVALID;
189 }
190 }
191
192 /* Create a slice which exactly covers the given image. */
ML_(sli_from_img)193 static inline DiSlice ML_(sli_from_img)( DiImage* img ) {
194 if (img) {
195 return mk_DiSlice(img, 0, ML_(img_size)(img));
196 } else {
197 return DiSlice_INVALID;
198 }
199 }
200
201
202 /*------------------------------------------------------------*/
203 /*--- Functions that operate on DiCursors ---*/
204 /*------------------------------------------------------------*/
205
206 /* Create a cursor from a slice, referring to the first byte of the
207 slice. */
ML_(cur_from_sli)208 static inline DiCursor ML_(cur_from_sli)( DiSlice sl ) {
209 if (ML_(sli_is_valid)(sl)) {
210 DiCursor c;
211 c.img = sl.img;
212 c.ioff = sl.ioff;
213 return c;
214 } else {
215 return DiCursor_INVALID;
216 }
217 }
218
ML_(cur_cmpLT)219 static inline Bool ML_(cur_cmpLT)( DiCursor c1, DiCursor c2 ) {
220 vg_assert(c1.img == c2.img);
221 return c1.ioff < c2.ioff;
222 }
ML_(cur_cmpEQ)223 static inline Bool ML_(cur_cmpEQ)( DiCursor c1, DiCursor c2 ) {
224 vg_assert(c1.img == c2.img);
225 return c1.ioff == c2.ioff;
226 }
ML_(cur_cmpGT)227 static inline Bool ML_(cur_cmpGT)( DiCursor c1, DiCursor c2 ) {
228 vg_assert(c1.img == c2.img);
229 return c1.ioff > c2.ioff;
230 }
231
ML_(cur_plus)232 static inline DiCursor ML_(cur_plus)( DiCursor c, Long n ) {
233 c.ioff += (DiOffT)n;
234 return c;
235 }
236
237 /* Asserts that c1 and c2 refer to the same image. Returns the difference
238 in offsets (c1.ioff - c2.ioff). */
ML_(cur_minus)239 static inline Long ML_(cur_minus)( DiCursor c1, DiCursor c2 ) {
240 vg_assert(c1.img == c2.img);
241 return (Long)(c1.ioff) - (Long)(c2.ioff);
242 }
243
ML_(cur_strlen)244 static inline SizeT ML_(cur_strlen)( DiCursor c ) {
245 return ML_(img_strlen)( c.img, c.ioff );
246 }
247
248 // strdup from the given cursor. Caller must ML_(dinfo_free) the
249 // resulting string.
ML_(cur_read_strdup)250 static inline HChar* ML_(cur_read_strdup)( DiCursor c, const HChar* cc ) {
251 vg_assert(c.ioff != DiOffT_INVALID);
252 HChar* res = ML_(img_strdup)(c.img, cc, c.ioff);
253 return res;
254 }
255 // strdup from the given cursor and advance it. Caller must
256 // ML_(dinfo_free) the resulting string.
ML_(cur_step_strdup)257 static inline HChar* ML_(cur_step_strdup)( DiCursor* c, const HChar* cc ) {
258 vg_assert(c->ioff != DiOffT_INVALID);
259 HChar* res = ML_(img_strdup)(c->img, cc, c->ioff);
260 c->ioff += VG_(strlen)(res) + 1;
261 return res;
262 }
263
264 // Fetch an arbitrary number of bytes from the cursor.
ML_(cur_read_get)265 static inline void ML_(cur_read_get) ( /*OUT*/void* dst,
266 DiCursor c, SizeT size) {
267 ML_(img_get)(dst, c.img, c.ioff, size);
268 }
269
270 // Fetch an arbitrary number of bytes from the cursor, and advance it.
ML_(cur_step_get)271 static inline void ML_(cur_step_get) ( /*OUT*/void* dst,
272 DiCursor* c, SizeT size) {
273 ML_(img_get)(dst, c->img, c->ioff, size);
274 c->ioff += size;
275 }
276
277 // memdup from the given cursor. Caller must ML_(dinfo_free) the
278 // resulting block.
ML_(cur_read_memdup)279 static inline UChar* ML_(cur_read_memdup)( DiCursor c, SizeT size,
280 const HChar* cc )
281 {
282 UChar* dst = ML_(dinfo_zalloc)(cc, size);
283 if (size > 0)
284 ML_(cur_read_get)(dst, c, size);
285 return dst;
286 }
287
ML_(cur_read_UChar)288 static inline UChar ML_(cur_read_UChar) ( DiCursor c ) {
289 UChar r = ML_(img_get_UChar)( c.img, c.ioff );
290 return r;
291 }
ML_(cur_step_UChar)292 static inline UChar ML_(cur_step_UChar)( DiCursor* c ) {
293 UChar r = ML_(img_get_UChar)( c->img, c->ioff );
294 c->ioff += sizeof(UChar);
295 return r;
296 }
297
ML_(cur_read_UShort)298 static inline UShort ML_(cur_read_UShort) ( DiCursor c ) {
299 UShort r = ML_(img_get_UShort)( c.img, c.ioff );
300 return r;
301 }
ML_(cur_step_UShort)302 static inline UShort ML_(cur_step_UShort) ( DiCursor* c ) {
303 UShort r = ML_(img_get_UShort)( c->img, c->ioff );
304 c->ioff += sizeof(UShort);
305 return r;
306 }
ML_(cur_step_Short)307 static inline Short ML_(cur_step_Short) ( DiCursor* c ) {
308 return (Short)ML_(cur_step_UShort)( c );
309 }
310
ML_(cur_read_UInt)311 static inline UInt ML_(cur_read_UInt) ( DiCursor c ) {
312 UInt r = ML_(img_get_UInt)( c.img, c.ioff );
313 return r;
314 }
ML_(cur_step_UInt)315 static inline UInt ML_(cur_step_UInt) ( DiCursor* c ) {
316 UInt r = ML_(img_get_UInt)( c->img, c->ioff );
317 c->ioff += sizeof(UInt);
318 return r;
319 }
ML_(cur_step_Int)320 static inline Int ML_(cur_step_Int) ( DiCursor* c ) {
321 return (Int)ML_(cur_step_UInt)( c );
322 }
323
ML_(cur_read_ULong)324 static inline ULong ML_(cur_read_ULong) ( DiCursor c ) {
325 ULong r = ML_(img_get_ULong)( c.img, c.ioff );
326 return r;
327 }
ML_(cur_step_ULong)328 static inline ULong ML_(cur_step_ULong) ( DiCursor* c ) {
329 ULong r = ML_(img_get_ULong)( c->img, c->ioff );
330 c->ioff += sizeof(ULong);
331 return r;
332 }
ML_(cur_step_Long)333 static inline Long ML_(cur_step_Long) ( DiCursor* c ) {
334 return (Long)ML_(cur_step_ULong)( c );
335 }
336
ML_(cur_step_Addr)337 static inline Addr ML_(cur_step_Addr) ( DiCursor* c ) {
338 if (sizeof(Addr) == sizeof(UInt)) {
339 return ML_(cur_step_UInt)(c);
340 } else if (sizeof(Addr) == sizeof(ULong)) {
341 return ML_(cur_step_ULong)(c);
342 } else {
343 vg_assert(0);
344 }
345 }
346
347 #endif /* ndef __PRIV_IMAGE_H */
348
349 /*--------------------------------------------------------------------*/
350 /*--- end priv_image.h ---*/
351 /*--------------------------------------------------------------------*/
352