1 | use alloc::vec::Vec; |
2 | use core::convert::TryInto; |
3 | use core::fmt::Debug; |
4 | use core::mem; |
5 | |
6 | use crate::read::{ |
7 | self, util, Architecture, ByteString, Bytes, Error, Export, FileFlags, Import, Object, |
8 | ObjectKind, ReadError, ReadRef, SectionIndex, StringTable, SymbolIndex, |
9 | }; |
10 | use crate::{elf, endian, Endian, Endianness, Pod, U32}; |
11 | |
12 | use super::{ |
13 | CompressionHeader, Dyn, ElfComdat, ElfComdatIterator, ElfDynamicRelocationIterator, ElfSection, |
14 | ElfSectionIterator, ElfSegment, ElfSegmentIterator, ElfSymbol, ElfSymbolIterator, |
15 | ElfSymbolTable, NoteHeader, ProgramHeader, Rel, Rela, RelocationSections, SectionHeader, |
16 | SectionTable, Sym, SymbolTable, |
17 | }; |
18 | |
19 | /// A 32-bit ELF object file. |
20 | /// |
21 | /// This is a file that starts with [`elf::FileHeader32`], and corresponds |
22 | /// to [`crate::FileKind::Elf32`]. |
23 | pub type ElfFile32<'data, Endian = Endianness, R = &'data [u8]> = |
24 | ElfFile<'data, elf::FileHeader32<Endian>, R>; |
25 | /// A 64-bit ELF object file. |
26 | /// |
27 | /// This is a file that starts with [`elf::FileHeader64`], and corresponds |
28 | /// to [`crate::FileKind::Elf64`]. |
29 | pub type ElfFile64<'data, Endian = Endianness, R = &'data [u8]> = |
30 | ElfFile<'data, elf::FileHeader64<Endian>, R>; |
31 | |
32 | /// A partially parsed ELF file. |
33 | /// |
34 | /// Most functionality is provided by the [`Object`] trait implementation. |
35 | #[derive (Debug)] |
36 | pub struct ElfFile<'data, Elf, R = &'data [u8]> |
37 | where |
38 | Elf: FileHeader, |
39 | R: ReadRef<'data>, |
40 | { |
41 | pub(super) endian: Elf::Endian, |
42 | pub(super) data: R, |
43 | pub(super) header: &'data Elf, |
44 | pub(super) segments: &'data [Elf::ProgramHeader], |
45 | pub(super) sections: SectionTable<'data, Elf, R>, |
46 | pub(super) relocations: RelocationSections, |
47 | pub(super) symbols: SymbolTable<'data, Elf, R>, |
48 | pub(super) dynamic_symbols: SymbolTable<'data, Elf, R>, |
49 | } |
50 | |
51 | impl<'data, Elf, R> ElfFile<'data, Elf, R> |
52 | where |
53 | Elf: FileHeader, |
54 | R: ReadRef<'data>, |
55 | { |
56 | /// Parse the raw ELF file data. |
57 | pub fn parse(data: R) -> read::Result<Self> { |
58 | let header = Elf::parse(data)?; |
59 | let endian = header.endian()?; |
60 | let segments = header.program_headers(endian, data)?; |
61 | let sections = header.sections(endian, data)?; |
62 | let symbols = sections.symbols(endian, data, elf::SHT_SYMTAB)?; |
63 | // TODO: get dynamic symbols from DT_SYMTAB if there are no sections |
64 | let dynamic_symbols = sections.symbols(endian, data, elf::SHT_DYNSYM)?; |
65 | // The API we provide requires a mapping from section to relocations, so build it now. |
66 | let relocations = sections.relocation_sections(endian, symbols.section())?; |
67 | |
68 | Ok(ElfFile { |
69 | endian, |
70 | data, |
71 | header, |
72 | segments, |
73 | sections, |
74 | relocations, |
75 | symbols, |
76 | dynamic_symbols, |
77 | }) |
78 | } |
79 | |
80 | /// Returns the endianness. |
81 | pub fn endian(&self) -> Elf::Endian { |
82 | self.endian |
83 | } |
84 | |
85 | /// Returns the raw data. |
86 | pub fn data(&self) -> R { |
87 | self.data |
88 | } |
89 | |
90 | /// Returns the raw ELF file header. |
91 | pub fn raw_header(&self) -> &'data Elf { |
92 | self.header |
93 | } |
94 | |
95 | /// Returns the raw ELF segments. |
96 | pub fn raw_segments(&self) -> &'data [Elf::ProgramHeader] { |
97 | self.segments |
98 | } |
99 | |
100 | fn raw_section_by_name<'file>( |
101 | &'file self, |
102 | section_name: &[u8], |
103 | ) -> Option<ElfSection<'data, 'file, Elf, R>> { |
104 | self.sections |
105 | .section_by_name(self.endian, section_name) |
106 | .map(|(index, section)| ElfSection { |
107 | file: self, |
108 | index: SectionIndex(index), |
109 | section, |
110 | }) |
111 | } |
112 | |
113 | #[cfg (feature = "compression" )] |
114 | fn zdebug_section_by_name<'file>( |
115 | &'file self, |
116 | section_name: &[u8], |
117 | ) -> Option<ElfSection<'data, 'file, Elf, R>> { |
118 | if !section_name.starts_with(b".debug_" ) { |
119 | return None; |
120 | } |
121 | let mut name = Vec::with_capacity(section_name.len() + 1); |
122 | name.extend_from_slice(b".zdebug_" ); |
123 | name.extend_from_slice(§ion_name[7..]); |
124 | self.raw_section_by_name(&name) |
125 | } |
126 | |
127 | #[cfg (not(feature = "compression" ))] |
128 | fn zdebug_section_by_name<'file>( |
129 | &'file self, |
130 | _section_name: &[u8], |
131 | ) -> Option<ElfSection<'data, 'file, Elf, R>> { |
132 | None |
133 | } |
134 | } |
135 | |
136 | impl<'data, Elf, R> read::private::Sealed for ElfFile<'data, Elf, R> |
137 | where |
138 | Elf: FileHeader, |
139 | R: ReadRef<'data>, |
140 | { |
141 | } |
142 | |
143 | impl<'data, 'file, Elf, R> Object<'data, 'file> for ElfFile<'data, Elf, R> |
144 | where |
145 | 'data: 'file, |
146 | Elf: FileHeader, |
147 | R: 'file + ReadRef<'data>, |
148 | { |
149 | type Segment = ElfSegment<'data, 'file, Elf, R>; |
150 | type SegmentIterator = ElfSegmentIterator<'data, 'file, Elf, R>; |
151 | type Section = ElfSection<'data, 'file, Elf, R>; |
152 | type SectionIterator = ElfSectionIterator<'data, 'file, Elf, R>; |
153 | type Comdat = ElfComdat<'data, 'file, Elf, R>; |
154 | type ComdatIterator = ElfComdatIterator<'data, 'file, Elf, R>; |
155 | type Symbol = ElfSymbol<'data, 'file, Elf, R>; |
156 | type SymbolIterator = ElfSymbolIterator<'data, 'file, Elf, R>; |
157 | type SymbolTable = ElfSymbolTable<'data, 'file, Elf, R>; |
158 | type DynamicRelocationIterator = ElfDynamicRelocationIterator<'data, 'file, Elf, R>; |
159 | |
160 | fn architecture(&self) -> Architecture { |
161 | match ( |
162 | self.header.e_machine(self.endian), |
163 | self.header.is_class_64(), |
164 | ) { |
165 | (elf::EM_AARCH64, true) => Architecture::Aarch64, |
166 | (elf::EM_AARCH64, false) => Architecture::Aarch64_Ilp32, |
167 | (elf::EM_ARM, _) => Architecture::Arm, |
168 | (elf::EM_AVR, _) => Architecture::Avr, |
169 | (elf::EM_BPF, _) => Architecture::Bpf, |
170 | (elf::EM_CSKY, _) => Architecture::Csky, |
171 | (elf::EM_386, _) => Architecture::I386, |
172 | (elf::EM_X86_64, false) => Architecture::X86_64_X32, |
173 | (elf::EM_X86_64, true) => Architecture::X86_64, |
174 | (elf::EM_HEXAGON, _) => Architecture::Hexagon, |
175 | (elf::EM_LOONGARCH, true) => Architecture::LoongArch64, |
176 | (elf::EM_MIPS, false) => Architecture::Mips, |
177 | (elf::EM_MIPS, true) => Architecture::Mips64, |
178 | (elf::EM_MSP430, _) => Architecture::Msp430, |
179 | (elf::EM_PPC, _) => Architecture::PowerPc, |
180 | (elf::EM_PPC64, _) => Architecture::PowerPc64, |
181 | (elf::EM_RISCV, false) => Architecture::Riscv32, |
182 | (elf::EM_RISCV, true) => Architecture::Riscv64, |
183 | // This is either s390 or s390x, depending on the ELF class. |
184 | // We only support the 64-bit variant s390x here. |
185 | (elf::EM_S390, true) => Architecture::S390x, |
186 | (elf::EM_SBF, _) => Architecture::Sbf, |
187 | (elf::EM_SHARC, false) => Architecture::Sharc, |
188 | (elf::EM_SPARCV9, true) => Architecture::Sparc64, |
189 | (elf::EM_XTENSA, false) => Architecture::Xtensa, |
190 | _ => Architecture::Unknown, |
191 | } |
192 | } |
193 | |
194 | #[inline ] |
195 | fn is_little_endian(&self) -> bool { |
196 | self.header.is_little_endian() |
197 | } |
198 | |
199 | #[inline ] |
200 | fn is_64(&self) -> bool { |
201 | self.header.is_class_64() |
202 | } |
203 | |
204 | fn kind(&self) -> ObjectKind { |
205 | match self.header.e_type(self.endian) { |
206 | elf::ET_REL => ObjectKind::Relocatable, |
207 | elf::ET_EXEC => ObjectKind::Executable, |
208 | // TODO: check for `DF_1_PIE`? |
209 | elf::ET_DYN => ObjectKind::Dynamic, |
210 | elf::ET_CORE => ObjectKind::Core, |
211 | _ => ObjectKind::Unknown, |
212 | } |
213 | } |
214 | |
215 | fn segments(&'file self) -> ElfSegmentIterator<'data, 'file, Elf, R> { |
216 | ElfSegmentIterator { |
217 | file: self, |
218 | iter: self.segments.iter(), |
219 | } |
220 | } |
221 | |
222 | fn section_by_name_bytes( |
223 | &'file self, |
224 | section_name: &[u8], |
225 | ) -> Option<ElfSection<'data, 'file, Elf, R>> { |
226 | self.raw_section_by_name(section_name) |
227 | .or_else(|| self.zdebug_section_by_name(section_name)) |
228 | } |
229 | |
230 | fn section_by_index( |
231 | &'file self, |
232 | index: SectionIndex, |
233 | ) -> read::Result<ElfSection<'data, 'file, Elf, R>> { |
234 | let section = self.sections.section(index)?; |
235 | Ok(ElfSection { |
236 | file: self, |
237 | index, |
238 | section, |
239 | }) |
240 | } |
241 | |
242 | fn sections(&'file self) -> ElfSectionIterator<'data, 'file, Elf, R> { |
243 | ElfSectionIterator { |
244 | file: self, |
245 | iter: self.sections.iter().enumerate(), |
246 | } |
247 | } |
248 | |
249 | fn comdats(&'file self) -> ElfComdatIterator<'data, 'file, Elf, R> { |
250 | ElfComdatIterator { |
251 | file: self, |
252 | iter: self.sections.iter().enumerate(), |
253 | } |
254 | } |
255 | |
256 | fn symbol_by_index( |
257 | &'file self, |
258 | index: SymbolIndex, |
259 | ) -> read::Result<ElfSymbol<'data, 'file, Elf, R>> { |
260 | let symbol = self.symbols.symbol(index.0)?; |
261 | Ok(ElfSymbol { |
262 | endian: self.endian, |
263 | symbols: &self.symbols, |
264 | index, |
265 | symbol, |
266 | }) |
267 | } |
268 | |
269 | fn symbols(&'file self) -> ElfSymbolIterator<'data, 'file, Elf, R> { |
270 | ElfSymbolIterator { |
271 | endian: self.endian, |
272 | symbols: &self.symbols, |
273 | index: 0, |
274 | } |
275 | } |
276 | |
277 | fn symbol_table(&'file self) -> Option<ElfSymbolTable<'data, 'file, Elf, R>> { |
278 | if self.symbols.is_empty() { |
279 | return None; |
280 | } |
281 | Some(ElfSymbolTable { |
282 | endian: self.endian, |
283 | symbols: &self.symbols, |
284 | }) |
285 | } |
286 | |
287 | fn dynamic_symbols(&'file self) -> ElfSymbolIterator<'data, 'file, Elf, R> { |
288 | ElfSymbolIterator { |
289 | endian: self.endian, |
290 | symbols: &self.dynamic_symbols, |
291 | index: 0, |
292 | } |
293 | } |
294 | |
295 | fn dynamic_symbol_table(&'file self) -> Option<ElfSymbolTable<'data, 'file, Elf, R>> { |
296 | if self.dynamic_symbols.is_empty() { |
297 | return None; |
298 | } |
299 | Some(ElfSymbolTable { |
300 | endian: self.endian, |
301 | symbols: &self.dynamic_symbols, |
302 | }) |
303 | } |
304 | |
305 | fn dynamic_relocations( |
306 | &'file self, |
307 | ) -> Option<ElfDynamicRelocationIterator<'data, 'file, Elf, R>> { |
308 | Some(ElfDynamicRelocationIterator { |
309 | section_index: SectionIndex(1), |
310 | file: self, |
311 | relocations: None, |
312 | }) |
313 | } |
314 | |
315 | fn imports(&self) -> read::Result<Vec<Import<'data>>> { |
316 | let mut imports = Vec::new(); |
317 | for symbol in self.dynamic_symbols.iter() { |
318 | if symbol.is_undefined(self.endian) { |
319 | let name = symbol.name(self.endian, self.dynamic_symbols.strings())?; |
320 | if !name.is_empty() { |
321 | // TODO: use symbol versioning to determine library |
322 | imports.push(Import { |
323 | name: ByteString(name), |
324 | library: ByteString(&[]), |
325 | }); |
326 | } |
327 | } |
328 | } |
329 | Ok(imports) |
330 | } |
331 | |
332 | fn exports(&self) -> read::Result<Vec<Export<'data>>> { |
333 | let mut exports = Vec::new(); |
334 | for symbol in self.dynamic_symbols.iter() { |
335 | if symbol.is_definition(self.endian) { |
336 | let name = symbol.name(self.endian, self.dynamic_symbols.strings())?; |
337 | let address = symbol.st_value(self.endian).into(); |
338 | exports.push(Export { |
339 | name: ByteString(name), |
340 | address, |
341 | }); |
342 | } |
343 | } |
344 | Ok(exports) |
345 | } |
346 | |
347 | fn has_debug_symbols(&self) -> bool { |
348 | for section in self.sections.iter() { |
349 | if let Ok(name) = self.sections.section_name(self.endian, section) { |
350 | if name == b".debug_info" || name == b".zdebug_info" { |
351 | return true; |
352 | } |
353 | } |
354 | } |
355 | false |
356 | } |
357 | |
358 | fn build_id(&self) -> read::Result<Option<&'data [u8]>> { |
359 | let endian = self.endian; |
360 | // Use section headers if present, otherwise use program headers. |
361 | if !self.sections.is_empty() { |
362 | for section in self.sections.iter() { |
363 | if let Some(mut notes) = section.notes(endian, self.data)? { |
364 | while let Some(note) = notes.next()? { |
365 | if note.name() == elf::ELF_NOTE_GNU |
366 | && note.n_type(endian) == elf::NT_GNU_BUILD_ID |
367 | { |
368 | return Ok(Some(note.desc())); |
369 | } |
370 | } |
371 | } |
372 | } |
373 | } else { |
374 | for segment in self.segments { |
375 | if let Some(mut notes) = segment.notes(endian, self.data)? { |
376 | while let Some(note) = notes.next()? { |
377 | if note.name() == elf::ELF_NOTE_GNU |
378 | && note.n_type(endian) == elf::NT_GNU_BUILD_ID |
379 | { |
380 | return Ok(Some(note.desc())); |
381 | } |
382 | } |
383 | } |
384 | } |
385 | } |
386 | Ok(None) |
387 | } |
388 | |
389 | fn gnu_debuglink(&self) -> read::Result<Option<(&'data [u8], u32)>> { |
390 | let section = match self.raw_section_by_name(b".gnu_debuglink" ) { |
391 | Some(section) => section, |
392 | None => return Ok(None), |
393 | }; |
394 | let data = section |
395 | .section |
396 | .data(self.endian, self.data) |
397 | .read_error("Invalid ELF .gnu_debuglink section offset or size" ) |
398 | .map(Bytes)?; |
399 | let filename = data |
400 | .read_string_at(0) |
401 | .read_error("Missing ELF .gnu_debuglink filename" )?; |
402 | let crc_offset = util::align(filename.len() + 1, 4); |
403 | let crc = data |
404 | .read_at::<U32<_>>(crc_offset) |
405 | .read_error("Missing ELF .gnu_debuglink crc" )? |
406 | .get(self.endian); |
407 | Ok(Some((filename, crc))) |
408 | } |
409 | |
410 | fn gnu_debugaltlink(&self) -> read::Result<Option<(&'data [u8], &'data [u8])>> { |
411 | let section = match self.raw_section_by_name(b".gnu_debugaltlink" ) { |
412 | Some(section) => section, |
413 | None => return Ok(None), |
414 | }; |
415 | let mut data = section |
416 | .section |
417 | .data(self.endian, self.data) |
418 | .read_error("Invalid ELF .gnu_debugaltlink section offset or size" ) |
419 | .map(Bytes)?; |
420 | let filename = data |
421 | .read_string() |
422 | .read_error("Missing ELF .gnu_debugaltlink filename" )?; |
423 | let build_id = data.0; |
424 | Ok(Some((filename, build_id))) |
425 | } |
426 | |
427 | fn relative_address_base(&self) -> u64 { |
428 | 0 |
429 | } |
430 | |
431 | fn entry(&self) -> u64 { |
432 | self.header.e_entry(self.endian).into() |
433 | } |
434 | |
435 | fn flags(&self) -> FileFlags { |
436 | FileFlags::Elf { |
437 | os_abi: self.header.e_ident().os_abi, |
438 | abi_version: self.header.e_ident().abi_version, |
439 | e_flags: self.header.e_flags(self.endian), |
440 | } |
441 | } |
442 | } |
443 | |
444 | /// A trait for generic access to [`elf::FileHeader32`] and [`elf::FileHeader64`]. |
445 | #[allow (missing_docs)] |
446 | pub trait FileHeader: Debug + Pod { |
447 | // Ideally this would be a `u64: From<Word>`, but can't express that. |
448 | type Word: Into<u64>; |
449 | type Sword: Into<i64>; |
450 | type Endian: endian::Endian; |
451 | type ProgramHeader: ProgramHeader<Elf = Self, Endian = Self::Endian, Word = Self::Word>; |
452 | type SectionHeader: SectionHeader<Elf = Self, Endian = Self::Endian, Word = Self::Word>; |
453 | type CompressionHeader: CompressionHeader<Endian = Self::Endian, Word = Self::Word>; |
454 | type NoteHeader: NoteHeader<Endian = Self::Endian>; |
455 | type Dyn: Dyn<Endian = Self::Endian, Word = Self::Word>; |
456 | type Sym: Sym<Endian = Self::Endian, Word = Self::Word>; |
457 | type Rel: Rel<Endian = Self::Endian, Word = Self::Word>; |
458 | type Rela: Rela<Endian = Self::Endian, Word = Self::Word> + From<Self::Rel>; |
459 | |
460 | /// Return true if this type is a 64-bit header. |
461 | /// |
462 | /// This is a property of the type, not a value in the header data. |
463 | fn is_type_64(&self) -> bool; |
464 | |
465 | /// Return true if this type is a 64-bit header. |
466 | /// |
467 | /// This is a property of the type, not a value in the header data. |
468 | /// |
469 | /// This is the same as [`Self::is_type_64`], but is non-dispatchable. |
470 | fn is_type_64_sized() -> bool |
471 | where |
472 | Self: Sized; |
473 | |
474 | fn e_ident(&self) -> &elf::Ident; |
475 | fn e_type(&self, endian: Self::Endian) -> u16; |
476 | fn e_machine(&self, endian: Self::Endian) -> u16; |
477 | fn e_version(&self, endian: Self::Endian) -> u32; |
478 | fn e_entry(&self, endian: Self::Endian) -> Self::Word; |
479 | fn e_phoff(&self, endian: Self::Endian) -> Self::Word; |
480 | fn e_shoff(&self, endian: Self::Endian) -> Self::Word; |
481 | fn e_flags(&self, endian: Self::Endian) -> u32; |
482 | fn e_ehsize(&self, endian: Self::Endian) -> u16; |
483 | fn e_phentsize(&self, endian: Self::Endian) -> u16; |
484 | fn e_phnum(&self, endian: Self::Endian) -> u16; |
485 | fn e_shentsize(&self, endian: Self::Endian) -> u16; |
486 | fn e_shnum(&self, endian: Self::Endian) -> u16; |
487 | fn e_shstrndx(&self, endian: Self::Endian) -> u16; |
488 | |
489 | // Provided methods. |
490 | |
491 | /// Read the file header. |
492 | /// |
493 | /// Also checks that the ident field in the file header is a supported format. |
494 | fn parse<'data, R: ReadRef<'data>>(data: R) -> read::Result<&'data Self> { |
495 | let header = data |
496 | .read_at::<Self>(0) |
497 | .read_error("Invalid ELF header size or alignment" )?; |
498 | if !header.is_supported() { |
499 | return Err(Error("Unsupported ELF header" )); |
500 | } |
501 | // TODO: Check self.e_ehsize? |
502 | Ok(header) |
503 | } |
504 | |
505 | /// Check that the ident field in the file header is a supported format. |
506 | /// |
507 | /// This checks the magic number, version, class, and endianness. |
508 | fn is_supported(&self) -> bool { |
509 | let ident = self.e_ident(); |
510 | // TODO: Check self.e_version too? Requires endian though. |
511 | ident.magic == elf::ELFMAG |
512 | && (self.is_type_64() || self.is_class_32()) |
513 | && (!self.is_type_64() || self.is_class_64()) |
514 | && (self.is_little_endian() || self.is_big_endian()) |
515 | && ident.version == elf::EV_CURRENT |
516 | } |
517 | |
518 | fn is_class_32(&self) -> bool { |
519 | self.e_ident().class == elf::ELFCLASS32 |
520 | } |
521 | |
522 | fn is_class_64(&self) -> bool { |
523 | self.e_ident().class == elf::ELFCLASS64 |
524 | } |
525 | |
526 | fn is_little_endian(&self) -> bool { |
527 | self.e_ident().data == elf::ELFDATA2LSB |
528 | } |
529 | |
530 | fn is_big_endian(&self) -> bool { |
531 | self.e_ident().data == elf::ELFDATA2MSB |
532 | } |
533 | |
534 | fn endian(&self) -> read::Result<Self::Endian> { |
535 | Self::Endian::from_big_endian(self.is_big_endian()).read_error("Unsupported ELF endian" ) |
536 | } |
537 | |
538 | /// Return the first section header, if present. |
539 | /// |
540 | /// Section 0 is a special case because getting the section headers normally |
541 | /// requires `shnum`, but `shnum` may be in the first section header. |
542 | fn section_0<'data, R: ReadRef<'data>>( |
543 | &self, |
544 | endian: Self::Endian, |
545 | data: R, |
546 | ) -> read::Result<Option<&'data Self::SectionHeader>> { |
547 | let shoff: u64 = self.e_shoff(endian).into(); |
548 | if shoff == 0 { |
549 | // No section headers is ok. |
550 | return Ok(None); |
551 | } |
552 | let shentsize = usize::from(self.e_shentsize(endian)); |
553 | if shentsize != mem::size_of::<Self::SectionHeader>() { |
554 | // Section header size must match. |
555 | return Err(Error("Invalid ELF section header entry size" )); |
556 | } |
557 | data.read_at(shoff) |
558 | .map(Some) |
559 | .read_error("Invalid ELF section header offset or size" ) |
560 | } |
561 | |
562 | /// Return the `e_phnum` field of the header. Handles extended values. |
563 | /// |
564 | /// Returns `Err` for invalid values. |
565 | fn phnum<'data, R: ReadRef<'data>>( |
566 | &self, |
567 | endian: Self::Endian, |
568 | data: R, |
569 | ) -> read::Result<usize> { |
570 | let e_phnum = self.e_phnum(endian); |
571 | if e_phnum < elf::PN_XNUM { |
572 | Ok(e_phnum as usize) |
573 | } else if let Some(section_0) = self.section_0(endian, data)? { |
574 | Ok(section_0.sh_info(endian) as usize) |
575 | } else { |
576 | // Section 0 must exist if e_phnum overflows. |
577 | Err(Error("Missing ELF section headers for e_phnum overflow" )) |
578 | } |
579 | } |
580 | |
581 | /// Return the `e_shnum` field of the header. Handles extended values. |
582 | /// |
583 | /// Returns `Err` for invalid values. |
584 | fn shnum<'data, R: ReadRef<'data>>( |
585 | &self, |
586 | endian: Self::Endian, |
587 | data: R, |
588 | ) -> read::Result<usize> { |
589 | let e_shnum = self.e_shnum(endian); |
590 | if e_shnum > 0 { |
591 | Ok(e_shnum as usize) |
592 | } else if let Some(section_0) = self.section_0(endian, data)? { |
593 | section_0 |
594 | .sh_size(endian) |
595 | .into() |
596 | .try_into() |
597 | .ok() |
598 | .read_error("Invalid ELF extended e_shnum" ) |
599 | } else { |
600 | // No section headers is ok. |
601 | Ok(0) |
602 | } |
603 | } |
604 | |
605 | /// Return the `e_shstrndx` field of the header. Handles extended values. |
606 | /// |
607 | /// Returns `Err` for invalid values (including if the index is 0). |
608 | fn shstrndx<'data, R: ReadRef<'data>>( |
609 | &self, |
610 | endian: Self::Endian, |
611 | data: R, |
612 | ) -> read::Result<u32> { |
613 | let e_shstrndx = self.e_shstrndx(endian); |
614 | let index = if e_shstrndx != elf::SHN_XINDEX { |
615 | e_shstrndx.into() |
616 | } else if let Some(section_0) = self.section_0(endian, data)? { |
617 | section_0.sh_link(endian) |
618 | } else { |
619 | // Section 0 must exist if we're trying to read e_shstrndx. |
620 | return Err(Error("Missing ELF section headers for e_shstrndx overflow" )); |
621 | }; |
622 | if index == 0 { |
623 | return Err(Error("Missing ELF e_shstrndx" )); |
624 | } |
625 | Ok(index) |
626 | } |
627 | |
628 | /// Return the slice of program headers. |
629 | /// |
630 | /// Returns `Ok(&[])` if there are no program headers. |
631 | /// Returns `Err` for invalid values. |
632 | fn program_headers<'data, R: ReadRef<'data>>( |
633 | &self, |
634 | endian: Self::Endian, |
635 | data: R, |
636 | ) -> read::Result<&'data [Self::ProgramHeader]> { |
637 | let phoff: u64 = self.e_phoff(endian).into(); |
638 | if phoff == 0 { |
639 | // No program headers is ok. |
640 | return Ok(&[]); |
641 | } |
642 | let phnum = self.phnum(endian, data)?; |
643 | if phnum == 0 { |
644 | // No program headers is ok. |
645 | return Ok(&[]); |
646 | } |
647 | let phentsize = self.e_phentsize(endian) as usize; |
648 | if phentsize != mem::size_of::<Self::ProgramHeader>() { |
649 | // Program header size must match. |
650 | return Err(Error("Invalid ELF program header entry size" )); |
651 | } |
652 | data.read_slice_at(phoff, phnum) |
653 | .read_error("Invalid ELF program header size or alignment" ) |
654 | } |
655 | |
656 | /// Return the slice of section headers. |
657 | /// |
658 | /// Returns `Ok(&[])` if there are no section headers. |
659 | /// Returns `Err` for invalid values. |
660 | fn section_headers<'data, R: ReadRef<'data>>( |
661 | &self, |
662 | endian: Self::Endian, |
663 | data: R, |
664 | ) -> read::Result<&'data [Self::SectionHeader]> { |
665 | let shoff: u64 = self.e_shoff(endian).into(); |
666 | if shoff == 0 { |
667 | // No section headers is ok. |
668 | return Ok(&[]); |
669 | } |
670 | let shnum = self.shnum(endian, data)?; |
671 | if shnum == 0 { |
672 | // No section headers is ok. |
673 | return Ok(&[]); |
674 | } |
675 | let shentsize = usize::from(self.e_shentsize(endian)); |
676 | if shentsize != mem::size_of::<Self::SectionHeader>() { |
677 | // Section header size must match. |
678 | return Err(Error("Invalid ELF section header entry size" )); |
679 | } |
680 | data.read_slice_at(shoff, shnum) |
681 | .read_error("Invalid ELF section header offset/size/alignment" ) |
682 | } |
683 | |
684 | /// Return the string table for the section headers. |
685 | fn section_strings<'data, R: ReadRef<'data>>( |
686 | &self, |
687 | endian: Self::Endian, |
688 | data: R, |
689 | sections: &[Self::SectionHeader], |
690 | ) -> read::Result<StringTable<'data, R>> { |
691 | if sections.is_empty() { |
692 | return Ok(StringTable::default()); |
693 | } |
694 | let index = self.shstrndx(endian, data)? as usize; |
695 | let shstrtab = sections.get(index).read_error("Invalid ELF e_shstrndx" )?; |
696 | let strings = if let Some((shstrtab_offset, shstrtab_size)) = shstrtab.file_range(endian) { |
697 | let shstrtab_end = shstrtab_offset |
698 | .checked_add(shstrtab_size) |
699 | .read_error("Invalid ELF shstrtab size" )?; |
700 | StringTable::new(data, shstrtab_offset, shstrtab_end) |
701 | } else { |
702 | StringTable::default() |
703 | }; |
704 | Ok(strings) |
705 | } |
706 | |
707 | /// Return the section table. |
708 | fn sections<'data, R: ReadRef<'data>>( |
709 | &self, |
710 | endian: Self::Endian, |
711 | data: R, |
712 | ) -> read::Result<SectionTable<'data, Self, R>> { |
713 | let sections = self.section_headers(endian, data)?; |
714 | let strings = self.section_strings(endian, data, sections)?; |
715 | Ok(SectionTable::new(sections, strings)) |
716 | } |
717 | |
718 | /// Returns whether this is a mips64el elf file. |
719 | fn is_mips64el(&self, endian: Self::Endian) -> bool { |
720 | self.is_class_64() && self.is_little_endian() && self.e_machine(endian) == elf::EM_MIPS |
721 | } |
722 | } |
723 | |
724 | impl<Endian: endian::Endian> FileHeader for elf::FileHeader32<Endian> { |
725 | type Word = u32; |
726 | type Sword = i32; |
727 | type Endian = Endian; |
728 | type ProgramHeader = elf::ProgramHeader32<Endian>; |
729 | type SectionHeader = elf::SectionHeader32<Endian>; |
730 | type CompressionHeader = elf::CompressionHeader32<Endian>; |
731 | type NoteHeader = elf::NoteHeader32<Endian>; |
732 | type Dyn = elf::Dyn32<Endian>; |
733 | type Sym = elf::Sym32<Endian>; |
734 | type Rel = elf::Rel32<Endian>; |
735 | type Rela = elf::Rela32<Endian>; |
736 | |
737 | #[inline ] |
738 | fn is_type_64(&self) -> bool { |
739 | false |
740 | } |
741 | |
742 | #[inline ] |
743 | fn is_type_64_sized() -> bool |
744 | where |
745 | Self: Sized, |
746 | { |
747 | false |
748 | } |
749 | |
750 | #[inline ] |
751 | fn e_ident(&self) -> &elf::Ident { |
752 | &self.e_ident |
753 | } |
754 | |
755 | #[inline ] |
756 | fn e_type(&self, endian: Self::Endian) -> u16 { |
757 | self.e_type.get(endian) |
758 | } |
759 | |
760 | #[inline ] |
761 | fn e_machine(&self, endian: Self::Endian) -> u16 { |
762 | self.e_machine.get(endian) |
763 | } |
764 | |
765 | #[inline ] |
766 | fn e_version(&self, endian: Self::Endian) -> u32 { |
767 | self.e_version.get(endian) |
768 | } |
769 | |
770 | #[inline ] |
771 | fn e_entry(&self, endian: Self::Endian) -> Self::Word { |
772 | self.e_entry.get(endian) |
773 | } |
774 | |
775 | #[inline ] |
776 | fn e_phoff(&self, endian: Self::Endian) -> Self::Word { |
777 | self.e_phoff.get(endian) |
778 | } |
779 | |
780 | #[inline ] |
781 | fn e_shoff(&self, endian: Self::Endian) -> Self::Word { |
782 | self.e_shoff.get(endian) |
783 | } |
784 | |
785 | #[inline ] |
786 | fn e_flags(&self, endian: Self::Endian) -> u32 { |
787 | self.e_flags.get(endian) |
788 | } |
789 | |
790 | #[inline ] |
791 | fn e_ehsize(&self, endian: Self::Endian) -> u16 { |
792 | self.e_ehsize.get(endian) |
793 | } |
794 | |
795 | #[inline ] |
796 | fn e_phentsize(&self, endian: Self::Endian) -> u16 { |
797 | self.e_phentsize.get(endian) |
798 | } |
799 | |
800 | #[inline ] |
801 | fn e_phnum(&self, endian: Self::Endian) -> u16 { |
802 | self.e_phnum.get(endian) |
803 | } |
804 | |
805 | #[inline ] |
806 | fn e_shentsize(&self, endian: Self::Endian) -> u16 { |
807 | self.e_shentsize.get(endian) |
808 | } |
809 | |
810 | #[inline ] |
811 | fn e_shnum(&self, endian: Self::Endian) -> u16 { |
812 | self.e_shnum.get(endian) |
813 | } |
814 | |
815 | #[inline ] |
816 | fn e_shstrndx(&self, endian: Self::Endian) -> u16 { |
817 | self.e_shstrndx.get(endian) |
818 | } |
819 | } |
820 | |
821 | impl<Endian: endian::Endian> FileHeader for elf::FileHeader64<Endian> { |
822 | type Word = u64; |
823 | type Sword = i64; |
824 | type Endian = Endian; |
825 | type ProgramHeader = elf::ProgramHeader64<Endian>; |
826 | type SectionHeader = elf::SectionHeader64<Endian>; |
827 | type CompressionHeader = elf::CompressionHeader64<Endian>; |
828 | type NoteHeader = elf::NoteHeader32<Endian>; |
829 | type Dyn = elf::Dyn64<Endian>; |
830 | type Sym = elf::Sym64<Endian>; |
831 | type Rel = elf::Rel64<Endian>; |
832 | type Rela = elf::Rela64<Endian>; |
833 | |
834 | #[inline ] |
835 | fn is_type_64(&self) -> bool { |
836 | true |
837 | } |
838 | |
839 | #[inline ] |
840 | fn is_type_64_sized() -> bool |
841 | where |
842 | Self: Sized, |
843 | { |
844 | true |
845 | } |
846 | |
847 | #[inline ] |
848 | fn e_ident(&self) -> &elf::Ident { |
849 | &self.e_ident |
850 | } |
851 | |
852 | #[inline ] |
853 | fn e_type(&self, endian: Self::Endian) -> u16 { |
854 | self.e_type.get(endian) |
855 | } |
856 | |
857 | #[inline ] |
858 | fn e_machine(&self, endian: Self::Endian) -> u16 { |
859 | self.e_machine.get(endian) |
860 | } |
861 | |
862 | #[inline ] |
863 | fn e_version(&self, endian: Self::Endian) -> u32 { |
864 | self.e_version.get(endian) |
865 | } |
866 | |
867 | #[inline ] |
868 | fn e_entry(&self, endian: Self::Endian) -> Self::Word { |
869 | self.e_entry.get(endian) |
870 | } |
871 | |
872 | #[inline ] |
873 | fn e_phoff(&self, endian: Self::Endian) -> Self::Word { |
874 | self.e_phoff.get(endian) |
875 | } |
876 | |
877 | #[inline ] |
878 | fn e_shoff(&self, endian: Self::Endian) -> Self::Word { |
879 | self.e_shoff.get(endian) |
880 | } |
881 | |
882 | #[inline ] |
883 | fn e_flags(&self, endian: Self::Endian) -> u32 { |
884 | self.e_flags.get(endian) |
885 | } |
886 | |
887 | #[inline ] |
888 | fn e_ehsize(&self, endian: Self::Endian) -> u16 { |
889 | self.e_ehsize.get(endian) |
890 | } |
891 | |
892 | #[inline ] |
893 | fn e_phentsize(&self, endian: Self::Endian) -> u16 { |
894 | self.e_phentsize.get(endian) |
895 | } |
896 | |
897 | #[inline ] |
898 | fn e_phnum(&self, endian: Self::Endian) -> u16 { |
899 | self.e_phnum.get(endian) |
900 | } |
901 | |
902 | #[inline ] |
903 | fn e_shentsize(&self, endian: Self::Endian) -> u16 { |
904 | self.e_shentsize.get(endian) |
905 | } |
906 | |
907 | #[inline ] |
908 | fn e_shnum(&self, endian: Self::Endian) -> u16 { |
909 | self.e_shnum.get(endian) |
910 | } |
911 | |
912 | #[inline ] |
913 | fn e_shstrndx(&self, endian: Self::Endian) -> u16 { |
914 | self.e_shstrndx.get(endian) |
915 | } |
916 | } |
917 | |