| 1 | use alloc::vec::Vec; |
| 2 | use core::fmt::Debug; |
| 3 | use core::{fmt, slice, str}; |
| 4 | |
| 5 | use crate::endian::{self, Endianness}; |
| 6 | use crate::macho; |
| 7 | use crate::pod::Pod; |
| 8 | use crate::read::util::StringTable; |
| 9 | use crate::read::{ |
| 10 | self, ObjectMap, ObjectMapEntry, ObjectMapFile, ObjectSymbol, ObjectSymbolTable, ReadError, |
| 11 | ReadRef, Result, SectionIndex, SectionKind, SymbolFlags, SymbolIndex, SymbolKind, SymbolMap, |
| 12 | SymbolMapEntry, SymbolScope, SymbolSection, |
| 13 | }; |
| 14 | |
| 15 | use super::{MachHeader, MachOFile}; |
| 16 | |
| 17 | /// A table of symbol entries in a Mach-O file. |
| 18 | /// |
| 19 | /// Also includes the string table used for the symbol names. |
| 20 | /// |
| 21 | /// Returned by [`macho::SymtabCommand::symbols`]. |
| 22 | #[derive (Debug, Clone, Copy)] |
| 23 | pub struct SymbolTable<'data, Mach: MachHeader, R = &'data [u8]> |
| 24 | where |
| 25 | R: ReadRef<'data>, |
| 26 | { |
| 27 | symbols: &'data [Mach::Nlist], |
| 28 | strings: StringTable<'data, R>, |
| 29 | } |
| 30 | |
| 31 | impl<'data, Mach: MachHeader, R: ReadRef<'data>> Default for SymbolTable<'data, Mach, R> { |
| 32 | fn default() -> Self { |
| 33 | SymbolTable { |
| 34 | symbols: &[], |
| 35 | strings: Default::default(), |
| 36 | } |
| 37 | } |
| 38 | } |
| 39 | |
| 40 | impl<'data, Mach: MachHeader, R: ReadRef<'data>> SymbolTable<'data, Mach, R> { |
| 41 | #[inline ] |
| 42 | pub(super) fn new(symbols: &'data [Mach::Nlist], strings: StringTable<'data, R>) -> Self { |
| 43 | SymbolTable { symbols, strings } |
| 44 | } |
| 45 | |
| 46 | /// Return the string table used for the symbol names. |
| 47 | #[inline ] |
| 48 | pub fn strings(&self) -> StringTable<'data, R> { |
| 49 | self.strings |
| 50 | } |
| 51 | |
| 52 | /// Iterate over the symbols. |
| 53 | #[inline ] |
| 54 | pub fn iter(&self) -> slice::Iter<'data, Mach::Nlist> { |
| 55 | self.symbols.iter() |
| 56 | } |
| 57 | |
| 58 | /// Return true if the symbol table is empty. |
| 59 | #[inline ] |
| 60 | pub fn is_empty(&self) -> bool { |
| 61 | self.symbols.is_empty() |
| 62 | } |
| 63 | |
| 64 | /// The number of symbols. |
| 65 | #[inline ] |
| 66 | pub fn len(&self) -> usize { |
| 67 | self.symbols.len() |
| 68 | } |
| 69 | |
| 70 | /// Return the symbol at the given index. |
| 71 | pub fn symbol(&self, index: SymbolIndex) -> Result<&'data Mach::Nlist> { |
| 72 | self.symbols |
| 73 | .get(index.0) |
| 74 | .read_error("Invalid Mach-O symbol index" ) |
| 75 | } |
| 76 | |
| 77 | /// Construct a map from addresses to a user-defined map entry. |
| 78 | pub fn map<Entry: SymbolMapEntry, F: Fn(&'data Mach::Nlist) -> Option<Entry>>( |
| 79 | &self, |
| 80 | f: F, |
| 81 | ) -> SymbolMap<Entry> { |
| 82 | let mut symbols = Vec::new(); |
| 83 | for nlist in self.symbols { |
| 84 | if !nlist.is_definition() { |
| 85 | continue; |
| 86 | } |
| 87 | if let Some(entry) = f(nlist) { |
| 88 | symbols.push(entry); |
| 89 | } |
| 90 | } |
| 91 | SymbolMap::new(symbols) |
| 92 | } |
| 93 | |
| 94 | /// Construct a map from addresses to symbol names and object file names. |
| 95 | pub fn object_map(&self, endian: Mach::Endian) -> ObjectMap<'data> { |
| 96 | let mut symbols = Vec::new(); |
| 97 | let mut objects = Vec::new(); |
| 98 | let mut object = None; |
| 99 | let mut current_function = None; |
| 100 | // Each module starts with one or two N_SO symbols (path, or directory + filename) |
| 101 | // and one N_OSO symbol. The module is terminated by an empty N_SO symbol. |
| 102 | for nlist in self.symbols { |
| 103 | let n_type = nlist.n_type(); |
| 104 | if n_type & macho::N_STAB == 0 { |
| 105 | continue; |
| 106 | } |
| 107 | // TODO: includes variables too (N_GSYM, N_STSYM). These may need to get their |
| 108 | // address from regular symbols though. |
| 109 | match n_type { |
| 110 | macho::N_SO => { |
| 111 | object = None; |
| 112 | } |
| 113 | macho::N_OSO => { |
| 114 | object = None; |
| 115 | if let Ok(name) = nlist.name(endian, self.strings) { |
| 116 | if !name.is_empty() { |
| 117 | object = Some(objects.len()); |
| 118 | // `N_OSO` symbol names can be either `/path/to/object.o` |
| 119 | // or `/path/to/archive.a(object.o)`. |
| 120 | let (path, member) = name |
| 121 | .split_last() |
| 122 | .and_then(|(last, head)| { |
| 123 | if *last != b')' { |
| 124 | return None; |
| 125 | } |
| 126 | let index = head.iter().position(|&x| x == b'(' )?; |
| 127 | let (archive, rest) = head.split_at(index); |
| 128 | Some((archive, Some(&rest[1..]))) |
| 129 | }) |
| 130 | .unwrap_or((name, None)); |
| 131 | objects.push(ObjectMapFile::new(path, member)); |
| 132 | } |
| 133 | } |
| 134 | } |
| 135 | macho::N_FUN => { |
| 136 | if let Ok(name) = nlist.name(endian, self.strings) { |
| 137 | if !name.is_empty() { |
| 138 | current_function = Some((name, nlist.n_value(endian).into())) |
| 139 | } else if let Some((name, address)) = current_function.take() { |
| 140 | if let Some(object) = object { |
| 141 | symbols.push(ObjectMapEntry { |
| 142 | address, |
| 143 | size: nlist.n_value(endian).into(), |
| 144 | name, |
| 145 | object, |
| 146 | }); |
| 147 | } |
| 148 | } |
| 149 | } |
| 150 | } |
| 151 | _ => {} |
| 152 | } |
| 153 | } |
| 154 | ObjectMap { |
| 155 | symbols: SymbolMap::new(symbols), |
| 156 | objects, |
| 157 | } |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | /// A symbol table in a [`MachOFile32`](super::MachOFile32). |
| 162 | pub type MachOSymbolTable32<'data, 'file, Endian = Endianness, R = &'data [u8]> = |
| 163 | MachOSymbolTable<'data, 'file, macho::MachHeader32<Endian>, R>; |
| 164 | /// A symbol table in a [`MachOFile64`](super::MachOFile64). |
| 165 | pub type MachOSymbolTable64<'data, 'file, Endian = Endianness, R = &'data [u8]> = |
| 166 | MachOSymbolTable<'data, 'file, macho::MachHeader64<Endian>, R>; |
| 167 | |
| 168 | /// A symbol table in a [`MachOFile`]. |
| 169 | #[derive (Debug, Clone, Copy)] |
| 170 | pub struct MachOSymbolTable<'data, 'file, Mach, R = &'data [u8]> |
| 171 | where |
| 172 | Mach: MachHeader, |
| 173 | R: ReadRef<'data>, |
| 174 | { |
| 175 | pub(super) file: &'file MachOFile<'data, Mach, R>, |
| 176 | } |
| 177 | |
| 178 | impl<'data, 'file, Mach, R> read::private::Sealed for MachOSymbolTable<'data, 'file, Mach, R> |
| 179 | where |
| 180 | Mach: MachHeader, |
| 181 | R: ReadRef<'data>, |
| 182 | { |
| 183 | } |
| 184 | |
| 185 | impl<'data, 'file, Mach, R> ObjectSymbolTable<'data> for MachOSymbolTable<'data, 'file, Mach, R> |
| 186 | where |
| 187 | Mach: MachHeader, |
| 188 | R: ReadRef<'data>, |
| 189 | { |
| 190 | type Symbol = MachOSymbol<'data, 'file, Mach, R>; |
| 191 | type SymbolIterator = MachOSymbolIterator<'data, 'file, Mach, R>; |
| 192 | |
| 193 | fn symbols(&self) -> Self::SymbolIterator { |
| 194 | MachOSymbolIterator::new(self.file) |
| 195 | } |
| 196 | |
| 197 | fn symbol_by_index(&self, index: SymbolIndex) -> Result<Self::Symbol> { |
| 198 | let nlist: &'data ::Nlist = self.file.symbols.symbol(index)?; |
| 199 | MachOSymbol::new(self.file, index, nlist).read_error("Unsupported Mach-O symbol index" ) |
| 200 | } |
| 201 | } |
| 202 | |
| 203 | /// An iterator for the symbols in a [`MachOFile32`](super::MachOFile32). |
| 204 | pub type MachOSymbolIterator32<'data, 'file, Endian = Endianness, R = &'data [u8]> = |
| 205 | MachOSymbolIterator<'data, 'file, macho::MachHeader32<Endian>, R>; |
| 206 | /// An iterator for the symbols in a [`MachOFile64`](super::MachOFile64). |
| 207 | pub type MachOSymbolIterator64<'data, 'file, Endian = Endianness, R = &'data [u8]> = |
| 208 | MachOSymbolIterator<'data, 'file, macho::MachHeader64<Endian>, R>; |
| 209 | |
| 210 | /// An iterator for the symbols in a [`MachOFile`]. |
| 211 | pub struct MachOSymbolIterator<'data, 'file, Mach, R = &'data [u8]> |
| 212 | where |
| 213 | Mach: MachHeader, |
| 214 | R: ReadRef<'data>, |
| 215 | { |
| 216 | file: &'file MachOFile<'data, Mach, R>, |
| 217 | index: SymbolIndex, |
| 218 | } |
| 219 | |
| 220 | impl<'data, 'file, Mach, R> MachOSymbolIterator<'data, 'file, Mach, R> |
| 221 | where |
| 222 | Mach: MachHeader, |
| 223 | R: ReadRef<'data>, |
| 224 | { |
| 225 | pub(super) fn new(file: &'file MachOFile<'data, Mach, R>) -> Self { |
| 226 | MachOSymbolIterator { |
| 227 | file, |
| 228 | index: SymbolIndex(0), |
| 229 | } |
| 230 | } |
| 231 | |
| 232 | pub(super) fn empty(file: &'file MachOFile<'data, Mach, R>) -> Self { |
| 233 | MachOSymbolIterator { |
| 234 | file, |
| 235 | index: SymbolIndex(file.symbols.len()), |
| 236 | } |
| 237 | } |
| 238 | } |
| 239 | |
| 240 | impl<'data, 'file, Mach, R> fmt::Debug for MachOSymbolIterator<'data, 'file, Mach, R> |
| 241 | where |
| 242 | Mach: MachHeader, |
| 243 | R: ReadRef<'data>, |
| 244 | { |
| 245 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| 246 | f.debug_struct(name:"MachOSymbolIterator" ).finish() |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | impl<'data, 'file, Mach, R> Iterator for MachOSymbolIterator<'data, 'file, Mach, R> |
| 251 | where |
| 252 | Mach: MachHeader, |
| 253 | R: ReadRef<'data>, |
| 254 | { |
| 255 | type Item = MachOSymbol<'data, 'file, Mach, R>; |
| 256 | |
| 257 | fn next(&mut self) -> Option<Self::Item> { |
| 258 | loop { |
| 259 | let index: SymbolIndex = self.index; |
| 260 | let nlist: &::Nlist = self.file.symbols.symbols.get(index.0)?; |
| 261 | self.index.0 += 1; |
| 262 | if let Some(symbol: MachOSymbol<'_, '_, Mach, …>) = MachOSymbol::new(self.file, index, nlist) { |
| 263 | return Some(symbol); |
| 264 | } |
| 265 | } |
| 266 | } |
| 267 | } |
| 268 | |
| 269 | /// A symbol in a [`MachOFile32`](super::MachOFile32). |
| 270 | pub type MachOSymbol32<'data, 'file, Endian = Endianness, R = &'data [u8]> = |
| 271 | MachOSymbol<'data, 'file, macho::MachHeader32<Endian>, R>; |
| 272 | /// A symbol in a [`MachOFile64`](super::MachOFile64). |
| 273 | pub type MachOSymbol64<'data, 'file, Endian = Endianness, R = &'data [u8]> = |
| 274 | MachOSymbol<'data, 'file, macho::MachHeader64<Endian>, R>; |
| 275 | |
| 276 | /// A symbol in a [`MachOFile`]. |
| 277 | /// |
| 278 | /// Most functionality is provided by the [`ObjectSymbol`] trait implementation. |
| 279 | #[derive (Debug, Clone, Copy)] |
| 280 | pub struct MachOSymbol<'data, 'file, Mach, R = &'data [u8]> |
| 281 | where |
| 282 | Mach: MachHeader, |
| 283 | R: ReadRef<'data>, |
| 284 | { |
| 285 | file: &'file MachOFile<'data, Mach, R>, |
| 286 | index: SymbolIndex, |
| 287 | nlist: &'data Mach::Nlist, |
| 288 | } |
| 289 | |
| 290 | impl<'data, 'file, Mach, R> MachOSymbol<'data, 'file, Mach, R> |
| 291 | where |
| 292 | Mach: MachHeader, |
| 293 | R: ReadRef<'data>, |
| 294 | { |
| 295 | pub(super) fn new( |
| 296 | file: &'file MachOFile<'data, Mach, R>, |
| 297 | index: SymbolIndex, |
| 298 | nlist: &'data Mach::Nlist, |
| 299 | ) -> Option<Self> { |
| 300 | if nlist.n_type() & macho::N_STAB != 0 { |
| 301 | return None; |
| 302 | } |
| 303 | Some(MachOSymbol { file, index, nlist }) |
| 304 | } |
| 305 | |
| 306 | /// Get the Mach-O file containing this symbol. |
| 307 | pub fn macho_file(&self) -> &'file MachOFile<'data, Mach, R> { |
| 308 | self.file |
| 309 | } |
| 310 | |
| 311 | /// Get the raw Mach-O symbol structure. |
| 312 | pub fn macho_symbol(&self) -> &'data Mach::Nlist { |
| 313 | self.nlist |
| 314 | } |
| 315 | } |
| 316 | |
| 317 | impl<'data, 'file, Mach, R> read::private::Sealed for MachOSymbol<'data, 'file, Mach, R> |
| 318 | where |
| 319 | Mach: MachHeader, |
| 320 | R: ReadRef<'data>, |
| 321 | { |
| 322 | } |
| 323 | |
| 324 | impl<'data, 'file, Mach, R> ObjectSymbol<'data> for MachOSymbol<'data, 'file, Mach, R> |
| 325 | where |
| 326 | Mach: MachHeader, |
| 327 | R: ReadRef<'data>, |
| 328 | { |
| 329 | #[inline ] |
| 330 | fn index(&self) -> SymbolIndex { |
| 331 | self.index |
| 332 | } |
| 333 | |
| 334 | fn name_bytes(&self) -> Result<&'data [u8]> { |
| 335 | self.nlist.name(self.file.endian, self.file.symbols.strings) |
| 336 | } |
| 337 | |
| 338 | fn name(&self) -> Result<&'data str> { |
| 339 | let name = self.name_bytes()?; |
| 340 | str::from_utf8(name) |
| 341 | .ok() |
| 342 | .read_error("Non UTF-8 Mach-O symbol name" ) |
| 343 | } |
| 344 | |
| 345 | #[inline ] |
| 346 | fn address(&self) -> u64 { |
| 347 | self.nlist.n_value(self.file.endian).into() |
| 348 | } |
| 349 | |
| 350 | #[inline ] |
| 351 | fn size(&self) -> u64 { |
| 352 | 0 |
| 353 | } |
| 354 | |
| 355 | fn kind(&self) -> SymbolKind { |
| 356 | self.section() |
| 357 | .index() |
| 358 | .and_then(|index| self.file.section_internal(index).ok()) |
| 359 | .map(|section| match section.kind { |
| 360 | SectionKind::Text => SymbolKind::Text, |
| 361 | SectionKind::Data |
| 362 | | SectionKind::ReadOnlyData |
| 363 | | SectionKind::ReadOnlyString |
| 364 | | SectionKind::UninitializedData |
| 365 | | SectionKind::Common => SymbolKind::Data, |
| 366 | SectionKind::Tls | SectionKind::UninitializedTls | SectionKind::TlsVariables => { |
| 367 | SymbolKind::Tls |
| 368 | } |
| 369 | _ => SymbolKind::Unknown, |
| 370 | }) |
| 371 | .unwrap_or(SymbolKind::Unknown) |
| 372 | } |
| 373 | |
| 374 | fn section(&self) -> SymbolSection { |
| 375 | match self.nlist.n_type() & macho::N_TYPE { |
| 376 | macho::N_UNDF => SymbolSection::Undefined, |
| 377 | macho::N_ABS => SymbolSection::Absolute, |
| 378 | macho::N_SECT => { |
| 379 | let n_sect = self.nlist.n_sect(); |
| 380 | if n_sect != 0 { |
| 381 | SymbolSection::Section(SectionIndex(n_sect as usize)) |
| 382 | } else { |
| 383 | SymbolSection::Unknown |
| 384 | } |
| 385 | } |
| 386 | _ => SymbolSection::Unknown, |
| 387 | } |
| 388 | } |
| 389 | |
| 390 | #[inline ] |
| 391 | fn is_undefined(&self) -> bool { |
| 392 | self.nlist.n_type() & macho::N_TYPE == macho::N_UNDF |
| 393 | } |
| 394 | |
| 395 | #[inline ] |
| 396 | fn is_definition(&self) -> bool { |
| 397 | self.nlist.is_definition() |
| 398 | } |
| 399 | |
| 400 | #[inline ] |
| 401 | fn is_common(&self) -> bool { |
| 402 | // Mach-O common symbols are based on section, not symbol |
| 403 | false |
| 404 | } |
| 405 | |
| 406 | #[inline ] |
| 407 | fn is_weak(&self) -> bool { |
| 408 | self.nlist.n_desc(self.file.endian) & (macho::N_WEAK_REF | macho::N_WEAK_DEF) != 0 |
| 409 | } |
| 410 | |
| 411 | fn scope(&self) -> SymbolScope { |
| 412 | let n_type = self.nlist.n_type(); |
| 413 | if n_type & macho::N_TYPE == macho::N_UNDF { |
| 414 | SymbolScope::Unknown |
| 415 | } else if n_type & macho::N_EXT == 0 { |
| 416 | SymbolScope::Compilation |
| 417 | } else if n_type & macho::N_PEXT != 0 { |
| 418 | SymbolScope::Linkage |
| 419 | } else { |
| 420 | SymbolScope::Dynamic |
| 421 | } |
| 422 | } |
| 423 | |
| 424 | #[inline ] |
| 425 | fn is_global(&self) -> bool { |
| 426 | self.scope() != SymbolScope::Compilation |
| 427 | } |
| 428 | |
| 429 | #[inline ] |
| 430 | fn is_local(&self) -> bool { |
| 431 | self.scope() == SymbolScope::Compilation |
| 432 | } |
| 433 | |
| 434 | #[inline ] |
| 435 | fn flags(&self) -> SymbolFlags<SectionIndex, SymbolIndex> { |
| 436 | let n_desc = self.nlist.n_desc(self.file.endian); |
| 437 | SymbolFlags::MachO { n_desc } |
| 438 | } |
| 439 | } |
| 440 | |
| 441 | /// A trait for generic access to [`macho::Nlist32`] and [`macho::Nlist64`]. |
| 442 | #[allow (missing_docs)] |
| 443 | pub trait Nlist: Debug + Pod { |
| 444 | type Word: Into<u64>; |
| 445 | type Endian: endian::Endian; |
| 446 | |
| 447 | fn n_strx(&self, endian: Self::Endian) -> u32; |
| 448 | fn n_type(&self) -> u8; |
| 449 | fn n_sect(&self) -> u8; |
| 450 | fn n_desc(&self, endian: Self::Endian) -> u16; |
| 451 | fn n_value(&self, endian: Self::Endian) -> Self::Word; |
| 452 | |
| 453 | fn name<'data, R: ReadRef<'data>>( |
| 454 | &self, |
| 455 | endian: Self::Endian, |
| 456 | strings: StringTable<'data, R>, |
| 457 | ) -> Result<&'data [u8]> { |
| 458 | strings |
| 459 | .get(self.n_strx(endian)) |
| 460 | .read_error("Invalid Mach-O symbol name offset" ) |
| 461 | } |
| 462 | |
| 463 | /// Return true if this is a STAB symbol. |
| 464 | /// |
| 465 | /// This determines the meaning of the `n_type` field. |
| 466 | fn is_stab(&self) -> bool { |
| 467 | self.n_type() & macho::N_STAB != 0 |
| 468 | } |
| 469 | |
| 470 | /// Return true if this is an undefined symbol. |
| 471 | fn is_undefined(&self) -> bool { |
| 472 | let n_type = self.n_type(); |
| 473 | n_type & macho::N_STAB == 0 && n_type & macho::N_TYPE == macho::N_UNDF |
| 474 | } |
| 475 | |
| 476 | /// Return true if the symbol is a definition of a function or data object. |
| 477 | fn is_definition(&self) -> bool { |
| 478 | let n_type = self.n_type(); |
| 479 | n_type & macho::N_STAB == 0 && n_type & macho::N_TYPE == macho::N_SECT |
| 480 | } |
| 481 | |
| 482 | /// Return the library ordinal. |
| 483 | /// |
| 484 | /// This is either a 1-based index into the dylib load commands, |
| 485 | /// or a special ordinal. |
| 486 | #[inline ] |
| 487 | fn library_ordinal(&self, endian: Self::Endian) -> u8 { |
| 488 | (self.n_desc(endian) >> 8) as u8 |
| 489 | } |
| 490 | } |
| 491 | |
| 492 | impl<Endian: endian::Endian> Nlist for macho::Nlist32<Endian> { |
| 493 | type Word = u32; |
| 494 | type Endian = Endian; |
| 495 | |
| 496 | fn n_strx(&self, endian: Self::Endian) -> u32 { |
| 497 | self.n_strx.get(endian) |
| 498 | } |
| 499 | fn n_type(&self) -> u8 { |
| 500 | self.n_type |
| 501 | } |
| 502 | fn n_sect(&self) -> u8 { |
| 503 | self.n_sect |
| 504 | } |
| 505 | fn n_desc(&self, endian: Self::Endian) -> u16 { |
| 506 | self.n_desc.get(endian) |
| 507 | } |
| 508 | fn n_value(&self, endian: Self::Endian) -> Self::Word { |
| 509 | self.n_value.get(endian) |
| 510 | } |
| 511 | } |
| 512 | |
| 513 | impl<Endian: endian::Endian> Nlist for macho::Nlist64<Endian> { |
| 514 | type Word = u64; |
| 515 | type Endian = Endian; |
| 516 | |
| 517 | fn n_strx(&self, endian: Self::Endian) -> u32 { |
| 518 | self.n_strx.get(endian) |
| 519 | } |
| 520 | fn n_type(&self) -> u8 { |
| 521 | self.n_type |
| 522 | } |
| 523 | fn n_sect(&self) -> u8 { |
| 524 | self.n_sect |
| 525 | } |
| 526 | fn n_desc(&self, endian: Self::Endian) -> u16 { |
| 527 | self.n_desc.get(endian) |
| 528 | } |
| 529 | fn n_value(&self, endian: Self::Endian) -> Self::Word { |
| 530 | self.n_value.get(endian) |
| 531 | } |
| 532 | } |
| 533 | |