1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
use alloc::vec::Vec;
use core::slice;
use crate::read::{Error, File, ReadError, ReadRef, Result};
use crate::{macho, Architecture, Endian, Endianness};
#[derive(Debug)]
pub struct DyldCache<'data, E = Endianness, R = &'data [u8]>
where
E: Endian,
R: ReadRef<'data>,
{
endian: E,
data: R,
subcaches: Vec<DyldSubCache<'data, E, R>>,
mappings: &'data [macho::DyldCacheMappingInfo<E>],
images: &'data [macho::DyldCacheImageInfo<E>],
arch: Architecture,
}
#[derive(Debug)]
pub struct DyldSubCache<'data, E = Endianness, R = &'data [u8]>
where
E: Endian,
R: ReadRef<'data>,
{
data: R,
mappings: &'data [macho::DyldCacheMappingInfo<E>],
}
const MIN_HEADER_SIZE_SUBCACHES: u32 = 0x1c4;
impl<'data, E, R> DyldCache<'data, E, R>
where
E: Endian,
R: ReadRef<'data>,
{
pub fn parse(data: R, subcache_data: &[R]) -> Result<Self> {
let header = macho::DyldCacheHeader::parse(data)?;
let (arch, endian) = header.parse_magic()?;
let mappings = header.mappings(endian, data)?;
let symbols_subcache_uuid = header.symbols_subcache_uuid(endian);
let subcaches_info = header.subcaches(endian, data)?.unwrap_or(&[]);
if subcache_data.len() != subcaches_info.len() + symbols_subcache_uuid.is_some() as usize {
return Err(Error("Incorrect number of SubCaches"));
}
let (symbols_subcache_data_and_uuid, subcache_data) =
if let Some(symbols_uuid) = symbols_subcache_uuid {
let (sym_data, rest_data) = subcache_data.split_last().unwrap();
(Some((*sym_data, symbols_uuid)), rest_data)
} else {
(None, subcache_data)
};
let mut subcaches = Vec::new();
for (&data, info) in subcache_data.iter().zip(subcaches_info.iter()) {
let sc_header = macho::DyldCacheHeader::<E>::parse(data)?;
if sc_header.uuid != info.uuid {
return Err(Error("Unexpected SubCache UUID"));
}
let mappings = sc_header.mappings(endian, data)?;
subcaches.push(DyldSubCache { data, mappings });
}
let _symbols_subcache = match symbols_subcache_data_and_uuid {
Some((data, uuid)) => {
let sc_header = macho::DyldCacheHeader::<E>::parse(data)?;
if sc_header.uuid != uuid {
return Err(Error("Unexpected .symbols SubCache UUID"));
}
let mappings = sc_header.mappings(endian, data)?;
Some(DyldSubCache { data, mappings })
}
None => None,
};
let images = header.images(endian, data)?;
Ok(DyldCache {
endian,
data,
subcaches,
mappings,
images,
arch,
})
}
pub fn architecture(&self) -> Architecture {
self.arch
}
#[inline]
pub fn endianness(&self) -> Endianness {
if self.is_little_endian() {
Endianness::Little
} else {
Endianness::Big
}
}
pub fn is_little_endian(&self) -> bool {
self.endian.is_little_endian()
}
pub fn images<'cache>(&'cache self) -> DyldCacheImageIterator<'data, 'cache, E, R> {
DyldCacheImageIterator {
cache: self,
iter: self.images.iter(),
}
}
pub fn data_and_offset_for_address(&self, address: u64) -> Option<(R, u64)> {
if let Some(file_offset) = address_to_file_offset(address, self.endian, self.mappings) {
return Some((self.data, file_offset));
}
for subcache in &self.subcaches {
if let Some(file_offset) =
address_to_file_offset(address, self.endian, subcache.mappings)
{
return Some((subcache.data, file_offset));
}
}
None
}
}
#[derive(Debug)]
pub struct DyldCacheImageIterator<'data, 'cache, E = Endianness, R = &'data [u8]>
where
E: Endian,
R: ReadRef<'data>,
{
cache: &'cache DyldCache<'data, E, R>,
iter: slice::Iter<'data, macho::DyldCacheImageInfo<E>>,
}
impl<'data, 'cache, E, R> Iterator for DyldCacheImageIterator<'data, 'cache, E, R>
where
E: Endian,
R: ReadRef<'data>,
{
type Item = DyldCacheImage<'data, 'cache, E, R>;
fn next(&mut self) -> Option<DyldCacheImage<'data, 'cache, E, R>> {
let image_info = self.iter.next()?;
Some(DyldCacheImage {
cache: self.cache,
image_info,
})
}
}
#[derive(Debug)]
pub struct DyldCacheImage<'data, 'cache, E = Endianness, R = &'data [u8]>
where
E: Endian,
R: ReadRef<'data>,
{
pub(crate) cache: &'cache DyldCache<'data, E, R>,
image_info: &'data macho::DyldCacheImageInfo<E>,
}
impl<'data, 'cache, E, R> DyldCacheImage<'data, 'cache, E, R>
where
E: Endian,
R: ReadRef<'data>,
{
pub fn path(&self) -> Result<&'data str> {
let path = self.image_info.path(self.cache.endian, self.cache.data)?;
let path = core::str::from_utf8(path).map_err(|_| Error("Path string not valid utf-8"))?;
Ok(path)
}
pub fn image_data_and_offset(&self) -> Result<(R, u64)> {
let address = self.image_info.address.get(self.cache.endian);
self.cache
.data_and_offset_for_address(address)
.ok_or(Error("Address not found in any mapping"))
}
pub fn parse_object(&self) -> Result<File<'data, R>> {
File::parse_dyld_cache_image(self)
}
}
impl<E: Endian> macho::DyldCacheHeader<E> {
pub fn parse<'data, R: ReadRef<'data>>(data: R) -> Result<&'data Self> {
data.read_at::<macho::DyldCacheHeader<E>>(0)
.read_error("Invalid dyld cache header size or alignment")
}
pub fn parse_magic(&self) -> Result<(Architecture, E)> {
let (arch, is_big_endian) = match &self.magic {
b"dyld_v1 i386\0" => (Architecture::I386, false),
b"dyld_v1 x86_64\0" => (Architecture::X86_64, false),
b"dyld_v1 x86_64h\0" => (Architecture::X86_64, false),
b"dyld_v1 ppc\0" => (Architecture::PowerPc, true),
b"dyld_v1 armv6\0" => (Architecture::Arm, false),
b"dyld_v1 armv7\0" => (Architecture::Arm, false),
b"dyld_v1 armv7f\0" => (Architecture::Arm, false),
b"dyld_v1 armv7s\0" => (Architecture::Arm, false),
b"dyld_v1 armv7k\0" => (Architecture::Arm, false),
b"dyld_v1 arm64\0" => (Architecture::Aarch64, false),
b"dyld_v1 arm64e\0" => (Architecture::Aarch64, false),
_ => return Err(Error("Unrecognized dyld cache magic")),
};
let endian =
E::from_big_endian(is_big_endian).read_error("Unsupported dyld cache endian")?;
Ok((arch, endian))
}
pub fn mappings<'data, R: ReadRef<'data>>(
&self,
endian: E,
data: R,
) -> Result<&'data [macho::DyldCacheMappingInfo<E>]> {
data.read_slice_at::<macho::DyldCacheMappingInfo<E>>(
self.mapping_offset.get(endian).into(),
self.mapping_count.get(endian) as usize,
)
.read_error("Invalid dyld cache mapping size or alignment")
}
pub fn subcaches<'data, R: ReadRef<'data>>(
&self,
endian: E,
data: R,
) -> Result<Option<&'data [macho::DyldSubCacheInfo<E>]>> {
if self.mapping_offset.get(endian) >= MIN_HEADER_SIZE_SUBCACHES {
let subcaches = data
.read_slice_at::<macho::DyldSubCacheInfo<E>>(
self.subcaches_offset.get(endian).into(),
self.subcaches_count.get(endian) as usize,
)
.read_error("Invalid dyld subcaches size or alignment")?;
Ok(Some(subcaches))
} else {
Ok(None)
}
}
pub fn symbols_subcache_uuid(&self, endian: E) -> Option<[u8; 16]> {
if self.mapping_offset.get(endian) >= MIN_HEADER_SIZE_SUBCACHES {
let uuid = self.symbols_subcache_uuid;
if uuid != [0; 16] {
return Some(uuid);
}
}
None
}
pub fn images<'data, R: ReadRef<'data>>(
&self,
endian: E,
data: R,
) -> Result<&'data [macho::DyldCacheImageInfo<E>]> {
if self.mapping_offset.get(endian) >= MIN_HEADER_SIZE_SUBCACHES {
data.read_slice_at::<macho::DyldCacheImageInfo<E>>(
self.images_across_all_subcaches_offset.get(endian).into(),
self.images_across_all_subcaches_count.get(endian) as usize,
)
.read_error("Invalid dyld cache image size or alignment")
} else {
data.read_slice_at::<macho::DyldCacheImageInfo<E>>(
self.images_offset.get(endian).into(),
self.images_count.get(endian) as usize,
)
.read_error("Invalid dyld cache image size or alignment")
}
}
}
impl<E: Endian> macho::DyldCacheImageInfo<E> {
pub fn path<'data, R: ReadRef<'data>>(&self, endian: E, data: R) -> Result<&'data [u8]> {
let r_start = self.path_file_offset.get(endian).into();
let r_end = data.len().read_error("Couldn't get data len()")?;
data.read_bytes_at_until(r_start..r_end, 0)
.read_error("Couldn't read dyld cache image path")
}
pub fn file_offset(
&self,
endian: E,
mappings: &[macho::DyldCacheMappingInfo<E>],
) -> Result<u64> {
let address = self.address.get(endian);
address_to_file_offset(address, endian, mappings)
.read_error("Invalid dyld cache image address")
}
}
pub fn address_to_file_offset<E: Endian>(
address: u64,
endian: E,
mappings: &[macho::DyldCacheMappingInfo<E>],
) -> Option<u64> {
for mapping in mappings {
let mapping_address = mapping.address.get(endian);
if address >= mapping_address
&& address < mapping_address.wrapping_add(mapping.size.get(endian))
{
return Some(address - mapping_address + mapping.file_offset.get(endian));
}
}
None
}