]>
Commit | Line | Data |
---|---|---|
f035d41b XL |
1 | use scroll::ctx::{self, SizeWith}; |
2 | use scroll::{Pread, Pwrite}; | |
3 | ||
4 | use log::{debug, warn}; | |
5 | ||
6 | use alloc::boxed::Box; | |
7 | use alloc::vec::Vec; | |
8 | use core::fmt; | |
9 | use core::ops::{Deref, DerefMut}; | |
10 | ||
11 | use crate::container; | |
12 | use crate::error; | |
13 | ||
14 | use crate::mach::constants::{SECTION_TYPE, S_GB_ZEROFILL, S_THREAD_LOCAL_ZEROFILL, S_ZEROFILL}; | |
15 | use crate::mach::load_command::{ | |
16 | Section32, Section64, SegmentCommand32, SegmentCommand64, LC_SEGMENT, LC_SEGMENT_64, | |
17 | SIZEOF_SECTION_32, SIZEOF_SECTION_64, SIZEOF_SEGMENT_COMMAND_32, SIZEOF_SEGMENT_COMMAND_64, | |
18 | }; | |
19 | use crate::mach::relocation::RelocationInfo; | |
20 | ||
21 | pub struct RelocationIterator<'a> { | |
22 | data: &'a [u8], | |
23 | nrelocs: usize, | |
24 | offset: usize, | |
25 | count: usize, | |
26 | ctx: scroll::Endian, | |
27 | } | |
28 | ||
29 | impl<'a> Iterator for RelocationIterator<'a> { | |
30 | type Item = error::Result<RelocationInfo>; | |
31 | fn next(&mut self) -> Option<Self::Item> { | |
32 | if self.count >= self.nrelocs { | |
33 | None | |
34 | } else { | |
35 | self.count += 1; | |
36 | match self.data.gread_with(&mut self.offset, self.ctx) { | |
37 | Ok(res) => Some(Ok(res)), | |
38 | Err(e) => Some(Err(e.into())), | |
39 | } | |
40 | } | |
41 | } | |
42 | } | |
43 | ||
44 | /// Generalized 32/64 bit Section | |
45 | #[derive(Default)] | |
46 | pub struct Section { | |
47 | /// name of this section | |
48 | pub sectname: [u8; 16], | |
49 | /// segment this section goes in | |
50 | pub segname: [u8; 16], | |
51 | /// memory address of this section | |
52 | pub addr: u64, | |
53 | /// size in bytes of this section | |
54 | pub size: u64, | |
55 | /// file offset of this section | |
56 | pub offset: u32, | |
57 | /// section alignment (power of 2) | |
58 | pub align: u32, | |
59 | /// file offset of relocation entries | |
60 | pub reloff: u32, | |
61 | /// number of relocation entries | |
62 | pub nreloc: u32, | |
63 | /// flags (section type and attributes | |
64 | pub flags: u32, | |
65 | } | |
66 | ||
67 | impl Section { | |
68 | /// The name of this section | |
69 | pub fn name(&self) -> error::Result<&str> { | |
70 | Ok(self.sectname.pread::<&str>(0)?) | |
71 | } | |
72 | /// The containing segment's name | |
73 | pub fn segname(&self) -> error::Result<&str> { | |
74 | Ok(self.segname.pread::<&str>(0)?) | |
75 | } | |
76 | /// Iterate this sections relocations given `data`; `data` must be the original binary | |
77 | pub fn iter_relocations<'b>( | |
78 | &self, | |
79 | data: &'b [u8], | |
80 | ctx: container::Ctx, | |
81 | ) -> RelocationIterator<'b> { | |
82 | let offset = self.reloff as usize; | |
83 | debug!( | |
84 | "Relocations for {} starting at offset: {:#x}", | |
85 | self.name().unwrap_or("BAD_SECTION_NAME"), | |
86 | offset | |
87 | ); | |
88 | RelocationIterator { | |
89 | offset, | |
90 | nrelocs: self.nreloc as usize, | |
91 | count: 0, | |
92 | data, | |
93 | ctx: ctx.le, | |
94 | } | |
95 | } | |
96 | } | |
97 | ||
98 | impl From<Section> for Section64 { | |
99 | fn from(section: Section) -> Self { | |
100 | Section64 { | |
101 | sectname: section.sectname, | |
102 | segname: section.segname, | |
103 | addr: section.addr as u64, | |
104 | size: section.size as u64, | |
105 | offset: section.offset, | |
106 | align: section.align, | |
107 | reloff: section.reloff, | |
108 | nreloc: section.nreloc, | |
109 | flags: section.flags, | |
110 | reserved1: 0, | |
111 | reserved2: 0, | |
112 | reserved3: 0, | |
113 | } | |
114 | } | |
115 | } | |
116 | ||
117 | impl From<Section> for Section32 { | |
118 | fn from(section: Section) -> Self { | |
119 | Section32 { | |
120 | sectname: section.sectname, | |
121 | segname: section.segname, | |
122 | addr: section.addr as u32, | |
123 | size: section.size as u32, | |
124 | offset: section.offset, | |
125 | align: section.align, | |
126 | reloff: section.reloff, | |
127 | nreloc: section.nreloc, | |
128 | flags: section.flags, | |
129 | reserved1: 0, | |
130 | reserved2: 0, | |
131 | } | |
132 | } | |
133 | } | |
134 | ||
135 | impl fmt::Debug for Section { | |
136 | fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { | |
137 | fmt.debug_struct("Section") | |
138 | .field("sectname", &self.name().unwrap()) | |
139 | .field("segname", &self.segname().unwrap()) | |
140 | .field("addr", &self.addr) | |
141 | .field("size", &self.size) | |
142 | .field("offset", &self.offset) | |
143 | .field("align", &self.align) | |
144 | .field("reloff", &self.reloff) | |
145 | .field("nreloc", &self.nreloc) | |
146 | .field("flags", &self.flags) | |
147 | .finish() | |
148 | } | |
149 | } | |
150 | ||
151 | impl From<Section32> for Section { | |
152 | fn from(section: Section32) -> Self { | |
153 | Section { | |
154 | sectname: section.sectname, | |
155 | segname: section.segname, | |
156 | addr: u64::from(section.addr), | |
157 | size: u64::from(section.size), | |
158 | offset: section.offset, | |
159 | align: section.align, | |
160 | reloff: section.reloff, | |
161 | nreloc: section.nreloc, | |
162 | flags: section.flags, | |
163 | } | |
164 | } | |
165 | } | |
166 | ||
167 | impl From<Section64> for Section { | |
168 | fn from(section: Section64) -> Self { | |
169 | Section { | |
170 | sectname: section.sectname, | |
171 | segname: section.segname, | |
172 | addr: section.addr, | |
173 | size: section.size, | |
174 | offset: section.offset, | |
175 | align: section.align, | |
176 | reloff: section.reloff, | |
177 | nreloc: section.nreloc, | |
178 | flags: section.flags, | |
179 | } | |
180 | } | |
181 | } | |
182 | ||
183 | impl<'a> ctx::TryFromCtx<'a, container::Ctx> for Section { | |
184 | type Error = crate::error::Error; | |
185 | fn try_from_ctx(bytes: &'a [u8], ctx: container::Ctx) -> Result<(Self, usize), Self::Error> { | |
186 | match ctx.container { | |
187 | container::Container::Little => { | |
188 | let section = Section::from(bytes.pread_with::<Section32>(0, ctx.le)?); | |
189 | Ok((section, SIZEOF_SECTION_32)) | |
190 | } | |
191 | container::Container::Big => { | |
192 | let section = Section::from(bytes.pread_with::<Section64>(0, ctx.le)?); | |
193 | Ok((section, SIZEOF_SECTION_64)) | |
194 | } | |
195 | } | |
196 | } | |
197 | } | |
198 | ||
199 | impl ctx::SizeWith<container::Ctx> for Section { | |
200 | fn size_with(ctx: &container::Ctx) -> usize { | |
201 | match ctx.container { | |
202 | container::Container::Little => SIZEOF_SECTION_32, | |
203 | container::Container::Big => SIZEOF_SECTION_64, | |
204 | } | |
205 | } | |
206 | } | |
207 | ||
208 | impl ctx::TryIntoCtx<container::Ctx> for Section { | |
209 | type Error = crate::error::Error; | |
210 | fn try_into_ctx(self, bytes: &mut [u8], ctx: container::Ctx) -> Result<usize, Self::Error> { | |
211 | if ctx.is_big() { | |
212 | bytes.pwrite_with::<Section64>(self.into(), 0, ctx.le)?; | |
213 | } else { | |
214 | bytes.pwrite_with::<Section32>(self.into(), 0, ctx.le)?; | |
215 | } | |
216 | Ok(Self::size_with(&ctx)) | |
217 | } | |
218 | } | |
219 | ||
220 | impl ctx::IntoCtx<container::Ctx> for Section { | |
221 | fn into_ctx(self, bytes: &mut [u8], ctx: container::Ctx) { | |
222 | bytes.pwrite_with(self, 0, ctx).unwrap(); | |
223 | } | |
224 | } | |
225 | ||
226 | pub struct SectionIterator<'a> { | |
227 | data: &'a [u8], | |
228 | count: usize, | |
229 | offset: usize, | |
230 | idx: usize, | |
231 | ctx: container::Ctx, | |
232 | } | |
233 | ||
234 | pub type SectionData<'a> = &'a [u8]; | |
235 | ||
236 | impl<'a> ::core::iter::ExactSizeIterator for SectionIterator<'a> { | |
237 | fn len(&self) -> usize { | |
238 | self.count | |
239 | } | |
240 | } | |
241 | ||
242 | impl<'a> Iterator for SectionIterator<'a> { | |
243 | type Item = error::Result<(Section, SectionData<'a>)>; | |
244 | fn next(&mut self) -> Option<Self::Item> { | |
245 | if self.idx >= self.count { | |
246 | None | |
247 | } else { | |
248 | self.idx += 1; | |
249 | match self.data.gread_with::<Section>(&mut self.offset, self.ctx) { | |
250 | Ok(section) => { | |
251 | let section_type = section.flags & SECTION_TYPE; | |
252 | let data = if section_type == S_ZEROFILL | |
253 | || section_type == S_GB_ZEROFILL | |
254 | || section_type == S_THREAD_LOCAL_ZEROFILL | |
255 | { | |
256 | &[] | |
257 | } else { | |
258 | // it's not uncommon to encounter macho files where files are | |
259 | // truncated but the sections are still remaining in the header. | |
260 | // Because of this we want to not panic here but instead just | |
261 | // slice down to a empty data slice. This way only if code | |
262 | // actually needs to access those sections it will fall over. | |
263 | self.data | |
264 | .get(section.offset as usize..) | |
265 | .unwrap_or_else(|| { | |
266 | warn!( | |
267 | "section #{} offset {} out of bounds", | |
268 | self.idx, section.offset | |
269 | ); | |
270 | &[] | |
271 | }) | |
272 | .get(..section.size as usize) | |
273 | .unwrap_or_else(|| { | |
274 | warn!("section #{} size {} out of bounds", self.idx, section.size); | |
275 | &[] | |
276 | }) | |
277 | }; | |
278 | Some(Ok((section, data))) | |
279 | } | |
280 | Err(e) => Some(Err(e)), | |
281 | } | |
282 | } | |
283 | } | |
284 | } | |
285 | ||
286 | impl<'a, 'b> IntoIterator for &'b Segment<'a> { | |
287 | type Item = error::Result<(Section, SectionData<'a>)>; | |
288 | type IntoIter = SectionIterator<'a>; | |
289 | fn into_iter(self) -> Self::IntoIter { | |
290 | SectionIterator { | |
291 | data: self.raw_data, | |
292 | count: self.nsects as usize, | |
293 | offset: self.offset + Segment::size_with(&self.ctx), | |
294 | idx: 0, | |
295 | ctx: self.ctx, | |
296 | } | |
297 | } | |
298 | } | |
299 | ||
300 | /// Generalized 32/64 bit Segment Command | |
301 | pub struct Segment<'a> { | |
302 | pub cmd: u32, | |
303 | pub cmdsize: u32, | |
304 | pub segname: [u8; 16], | |
305 | pub vmaddr: u64, | |
306 | pub vmsize: u64, | |
307 | pub fileoff: u64, | |
308 | pub filesize: u64, | |
309 | pub maxprot: u32, | |
310 | pub initprot: u32, | |
311 | pub nsects: u32, | |
312 | pub flags: u32, | |
313 | pub data: &'a [u8], | |
314 | offset: usize, | |
315 | raw_data: &'a [u8], | |
316 | ctx: container::Ctx, | |
317 | } | |
318 | ||
319 | impl<'a> From<Segment<'a>> for SegmentCommand64 { | |
320 | fn from(segment: Segment<'a>) -> Self { | |
321 | SegmentCommand64 { | |
322 | cmd: segment.cmd, | |
323 | cmdsize: segment.cmdsize, | |
324 | segname: segment.segname, | |
325 | vmaddr: segment.vmaddr as u64, | |
326 | vmsize: segment.vmsize as u64, | |
327 | fileoff: segment.fileoff as u64, | |
328 | filesize: segment.filesize as u64, | |
329 | maxprot: segment.maxprot, | |
330 | initprot: segment.initprot, | |
331 | nsects: segment.nsects, | |
332 | flags: segment.flags, | |
333 | } | |
334 | } | |
335 | } | |
336 | ||
337 | impl<'a> From<Segment<'a>> for SegmentCommand32 { | |
338 | fn from(segment: Segment<'a>) -> Self { | |
339 | SegmentCommand32 { | |
340 | cmd: segment.cmd, | |
341 | cmdsize: segment.cmdsize, | |
342 | segname: segment.segname, | |
343 | vmaddr: segment.vmaddr as u32, | |
344 | vmsize: segment.vmsize as u32, | |
345 | fileoff: segment.fileoff as u32, | |
346 | filesize: segment.filesize as u32, | |
347 | maxprot: segment.maxprot, | |
348 | initprot: segment.initprot, | |
349 | nsects: segment.nsects, | |
350 | flags: segment.flags, | |
351 | } | |
352 | } | |
353 | } | |
354 | ||
355 | impl<'a> fmt::Debug for Segment<'a> { | |
356 | fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { | |
357 | fmt.debug_struct("Segment") | |
358 | .field("cmd", &self.cmd) | |
359 | .field("cmdsize", &self.cmdsize) | |
360 | .field("segname", &self.segname.pread::<&str>(0).unwrap()) | |
361 | .field("vmaddr", &self.vmaddr) | |
362 | .field("vmsize", &self.vmsize) | |
363 | .field("fileoff", &self.fileoff) | |
364 | .field("filesize", &self.filesize) | |
365 | .field("maxprot", &self.maxprot) | |
366 | .field("initprot", &self.initprot) | |
367 | .field("nsects", &self.nsects) | |
368 | .field("flags", &self.flags) | |
369 | .field("data", &self.data.len()) | |
370 | .field( | |
371 | "sections()", | |
372 | &self.sections().map(|sections| { | |
373 | sections | |
374 | .into_iter() | |
375 | .map(|(section, _)| section) | |
376 | .collect::<Vec<_>>() | |
377 | }), | |
378 | ) | |
379 | .finish() | |
380 | } | |
381 | } | |
382 | ||
383 | impl<'a> ctx::SizeWith<container::Ctx> for Segment<'a> { | |
384 | fn size_with(ctx: &container::Ctx) -> usize { | |
385 | match ctx.container { | |
386 | container::Container::Little => SIZEOF_SEGMENT_COMMAND_32, | |
387 | container::Container::Big => SIZEOF_SEGMENT_COMMAND_64, | |
388 | } | |
389 | } | |
390 | } | |
391 | ||
392 | impl<'a> ctx::TryIntoCtx<container::Ctx> for Segment<'a> { | |
393 | type Error = crate::error::Error; | |
394 | fn try_into_ctx(self, bytes: &mut [u8], ctx: container::Ctx) -> Result<usize, Self::Error> { | |
395 | let segment_size = Self::size_with(&ctx); | |
396 | // should be able to write the section data inline after this, but not working at the moment | |
397 | //let section_size = bytes.pwrite(data, segment_size)?; | |
398 | //debug!("Segment size: {} raw section data size: {}", segment_size, data.len()); | |
399 | if ctx.is_big() { | |
400 | bytes.pwrite_with::<SegmentCommand64>(self.into(), 0, ctx.le)?; | |
401 | } else { | |
402 | bytes.pwrite_with::<SegmentCommand32>(self.into(), 0, ctx.le)?; | |
403 | } | |
404 | //debug!("Section size: {}", section_size); | |
405 | Ok(segment_size) | |
406 | } | |
407 | } | |
408 | ||
409 | impl<'a> ctx::IntoCtx<container::Ctx> for Segment<'a> { | |
410 | fn into_ctx(self, bytes: &mut [u8], ctx: container::Ctx) { | |
411 | bytes.pwrite_with(self, 0, ctx).unwrap(); | |
412 | } | |
413 | } | |
414 | ||
415 | /// Read data that belongs to a segment if the offset is within the boundaries of bytes. | |
416 | fn segment_data(bytes: &[u8], fileoff: u64, filesize: u64) -> Result<&[u8], error::Error> { | |
417 | let data: &[u8] = if filesize != 0 { | |
418 | bytes.pread_with(fileoff as usize, filesize as usize)? | |
419 | } else { | |
420 | &[] | |
421 | }; | |
422 | Ok(data) | |
423 | } | |
424 | ||
425 | impl<'a> Segment<'a> { | |
426 | /// Create a new, blank segment, with cmd either `LC_SEGMENT_64`, or `LC_SEGMENT`, depending on `ctx`. | |
427 | /// **NB** You are responsible for providing a correctly marshalled byte array as the sections. You should not use this for anything other than writing. | |
428 | pub fn new(ctx: container::Ctx, sections: &'a [u8]) -> Self { | |
429 | Segment { | |
430 | cmd: if ctx.is_big() { | |
431 | LC_SEGMENT_64 | |
432 | } else { | |
433 | LC_SEGMENT | |
434 | }, | |
435 | cmdsize: (Self::size_with(&ctx) + sections.len()) as u32, | |
436 | segname: [0; 16], | |
437 | vmaddr: 0, | |
438 | vmsize: 0, | |
439 | fileoff: 0, | |
440 | filesize: 0, | |
441 | maxprot: 0, | |
442 | initprot: 0, | |
443 | nsects: 0, | |
444 | flags: 0, | |
445 | data: sections, | |
446 | offset: 0, | |
447 | raw_data: &[], | |
448 | ctx, | |
449 | } | |
450 | } | |
451 | /// Get the name of this segment | |
452 | pub fn name(&self) -> error::Result<&str> { | |
453 | Ok(self.segname.pread::<&str>(0)?) | |
454 | } | |
455 | /// Get the sections from this segment, erroring if any section couldn't be retrieved | |
456 | pub fn sections(&self) -> error::Result<Vec<(Section, SectionData<'a>)>> { | |
457 | let mut sections = Vec::new(); | |
458 | for section in self.into_iter() { | |
459 | sections.push(section?); | |
460 | } | |
461 | Ok(sections) | |
462 | } | |
463 | /// Convert the raw C 32-bit segment command to a generalized version | |
464 | pub fn from_32( | |
465 | bytes: &'a [u8], | |
466 | segment: &SegmentCommand32, | |
467 | offset: usize, | |
468 | ctx: container::Ctx, | |
469 | ) -> Result<Self, error::Error> { | |
470 | Ok(Segment { | |
471 | cmd: segment.cmd, | |
472 | cmdsize: segment.cmdsize, | |
473 | segname: segment.segname, | |
474 | vmaddr: u64::from(segment.vmaddr), | |
475 | vmsize: u64::from(segment.vmsize), | |
476 | fileoff: u64::from(segment.fileoff), | |
477 | filesize: u64::from(segment.filesize), | |
478 | maxprot: segment.maxprot, | |
479 | initprot: segment.initprot, | |
480 | nsects: segment.nsects, | |
481 | flags: segment.flags, | |
482 | data: segment_data( | |
483 | bytes, | |
484 | u64::from(segment.fileoff), | |
485 | u64::from(segment.filesize), | |
486 | )?, | |
487 | offset, | |
488 | raw_data: bytes, | |
489 | ctx, | |
490 | }) | |
491 | } | |
492 | /// Convert the raw C 64-bit segment command to a generalized version | |
493 | pub fn from_64( | |
494 | bytes: &'a [u8], | |
495 | segment: &SegmentCommand64, | |
496 | offset: usize, | |
497 | ctx: container::Ctx, | |
498 | ) -> Result<Self, error::Error> { | |
499 | Ok(Segment { | |
500 | cmd: segment.cmd, | |
501 | cmdsize: segment.cmdsize, | |
502 | segname: segment.segname, | |
503 | vmaddr: segment.vmaddr, | |
504 | vmsize: segment.vmsize, | |
505 | fileoff: segment.fileoff, | |
506 | filesize: segment.filesize, | |
507 | maxprot: segment.maxprot, | |
508 | initprot: segment.initprot, | |
509 | nsects: segment.nsects, | |
510 | flags: segment.flags, | |
511 | data: segment_data(bytes, segment.fileoff, segment.filesize)?, | |
512 | offset, | |
513 | raw_data: bytes, | |
514 | ctx, | |
515 | }) | |
516 | } | |
517 | } | |
518 | ||
519 | #[derive(Debug, Default)] | |
520 | /// An opaque 32/64-bit container for Mach-o segments | |
521 | pub struct Segments<'a> { | |
522 | segments: Vec<Segment<'a>>, | |
523 | ctx: container::Ctx, | |
524 | } | |
525 | ||
526 | impl<'a> Deref for Segments<'a> { | |
527 | type Target = Vec<Segment<'a>>; | |
528 | fn deref(&self) -> &Self::Target { | |
529 | &self.segments | |
530 | } | |
531 | } | |
532 | ||
533 | impl<'a> DerefMut for Segments<'a> { | |
534 | fn deref_mut(&mut self) -> &mut Self::Target { | |
535 | &mut self.segments | |
536 | } | |
537 | } | |
538 | ||
539 | impl<'a, 'b> IntoIterator for &'b Segments<'a> { | |
540 | type Item = &'b Segment<'a>; | |
541 | type IntoIter = ::core::slice::Iter<'b, Segment<'a>>; | |
542 | fn into_iter(self) -> Self::IntoIter { | |
543 | self.segments.iter() | |
544 | } | |
545 | } | |
546 | ||
547 | impl<'a> Segments<'a> { | |
548 | /// Construct a new generalized segment container from this `ctx` | |
549 | pub fn new(ctx: container::Ctx) -> Self { | |
550 | Segments { | |
551 | segments: Vec::new(), | |
552 | ctx, | |
553 | } | |
554 | } | |
555 | /// Get every section from every segment | |
556 | // thanks to SpaceManic for figuring out the 'b lifetimes here :) | |
557 | pub fn sections<'b>(&'b self) -> Box<dyn Iterator<Item = SectionIterator<'a>> + 'b> { | |
558 | Box::new(self.segments.iter().map(|segment| segment.into_iter())) | |
559 | } | |
560 | } |