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use error::Error; use header::Header; use relocation::Relocation; use dynamic::Dynamic; use symbol::Symbol; use strtab::Strtab; use types; use std::io::{Read, Seek, SeekFrom, Write}; use std::io::BufWriter; #[derive(Default, Debug, Clone)] pub struct SectionHeader { pub name: u32, pub shtype: types::SectionType, pub flags: types::SectionFlags, pub addr: u64, pub offset: u64, pub size: u64, pub link: u32, pub info: u32, pub addralign: u64, pub entsize: u64, } impl SectionHeader { pub fn entsize(eh: &Header) -> usize { 4 + 4 + match eh.ident_class { types::Class::Class64 => 6 * 8, types::Class::Class32 => 6 * 4, } + 4 + 4 } pub fn from_reader<R>(io: &mut R, eh: &Header) -> Result<SectionHeader, Error> where R: Read, { elf_dispatch_endianness!(eh => { let mut r = SectionHeader::default(); r.name = read_u32(io)?; let reb = read_u32(io)?; r.shtype = types::SectionType(reb); elf_dispatch_uclass!(eh => { let reb = read_uclass(io)?; r.flags = match types::SectionFlags::from_bits(reb) { Some(v) => v, None => return Err(Error::InvalidSectionFlags(reb)), }; r.addr = read_uclass(io)?; r.offset = read_uclass(io)?; r.size = read_uclass(io)?; r.link = read_u32(io)?; r.info = read_u32(io)?; r.addralign = read_uclass(io)?; r.entsize = read_uclass(io)?; Ok(r) }) }) } pub fn to_writer<R>(&self, eh: &Header, io: &mut R) -> Result<(), Error> where R: Write, { let mut w = BufWriter::new(io); elf_write_u32!(eh, w, self.name)?; elf_write_u32!(eh, w, self.shtype.to_u32())?; elf_write_uclass!(eh, w, self.flags.bits())?; elf_write_uclass!(eh, w, self.addr)?; elf_write_uclass!(eh, w, self.offset)?; elf_write_uclass!(eh, w, self.size)?; elf_write_u32!(eh, w, self.link)?; elf_write_u32!(eh, w, self.info)?; elf_write_uclass!(eh, w, self.addralign)?; elf_write_uclass!(eh, w, self.entsize)?; Ok(()) } } #[derive(Debug, Clone)] pub enum SectionContent { None, Unloaded, Raw(Vec<u8>), Relocations(Vec<Relocation>), Symbols(Vec<Symbol>), Dynamic(Vec<Dynamic>), Strtab(Strtab), } impl Default for SectionContent { fn default() -> Self { SectionContent::None } } impl SectionContent { pub fn as_dynamic_mut(&mut self) -> Option<&mut Vec<Dynamic>> { match self { &mut SectionContent::Dynamic(ref mut v) => Some(v), _ => None, } } pub fn as_dynamic(&self) -> Option<&Vec<Dynamic>> { match self { &SectionContent::Dynamic(ref v) => Some(v), _ => None, } } pub fn into_dynamic(self) -> Option<Vec<Dynamic>> { match self { SectionContent::Dynamic(v) => Some(v), _ => None, } } pub fn as_strtab_mut(&mut self) -> Option<&mut Strtab> { match self { &mut SectionContent::Strtab(ref mut v) => Some(v), _ => None, } } pub fn as_symbols(&self) -> Option<&Vec<Symbol>> { match self { &SectionContent::Symbols(ref v) => Some(v), _ => None, } } pub fn as_symbols_mut(&mut self) -> Option<&mut Vec<Symbol>> { match self { &mut SectionContent::Symbols(ref mut v) => Some(v), _ => None, } } pub fn into_symbols(self) -> Option<Vec<Symbol>> { match self { SectionContent::Symbols(v) => Some(v), _ => None, } } pub fn as_relocations(&self) -> Option<&Vec<Relocation>> { match self { &SectionContent::Relocations(ref v) => Some(v), _ => None, } } pub fn as_relocations_mut(&mut self) -> Option<&mut Vec<Relocation>> { match self { &mut SectionContent::Relocations(ref mut v) => Some(v), _ => None, } } pub fn into_relocations(self) -> Option<Vec<Relocation>> { match self { SectionContent::Relocations(v) => Some(v), _ => None, } } pub fn as_raw(&self) -> Option<&Vec<u8>> { match self { &SectionContent::Raw(ref v) => Some(v), _ => None, } } pub fn as_raw_mut(&mut self) -> Option<&mut Vec<u8>> { match self { &mut SectionContent::Raw(ref mut v) => Some(v), _ => None, } } pub fn into_raw(self) -> Option<Vec<u8>> { match self { SectionContent::Raw(v) => Some(v), _ => None, } } pub fn size(&self, eh: &Header) -> usize { match self { &SectionContent::Unloaded => panic!("cannot size unloaded section"), &SectionContent::None => 0, &SectionContent::Raw(ref v) => v.len(), &SectionContent::Dynamic(ref v) => v.len() * Dynamic::entsize(eh), &SectionContent::Strtab(ref v) => v.len(eh), &SectionContent::Symbols(ref v) => v.len() * Symbol::entsize(eh), &SectionContent::Relocations(ref v) => v.len() * Relocation::entsize(eh), } } } #[derive(Debug, Default, Clone)] pub struct Section { pub header: SectionHeader, pub name: Vec<u8>, pub content: SectionContent, pub addrlock: bool, } impl Section { pub fn size(&self, eh: &Header) -> usize { self.content.size(eh) } pub fn new( name: Vec<u8>, shtype: types::SectionType, flags: types::SectionFlags, content: SectionContent, link: u32, info: u32, ) -> Section { Section { name: name, header: SectionHeader { name: 0, shtype: shtype, flags: flags, addr: 0, offset: 0, size: 0, link: link, info: info, addralign: 0, entsize: 0, }, content: content, addrlock: false, } } pub fn sync( &mut self, eh: &Header, mut linked: Option<&mut SectionContent>, ) -> Result<(), Error> { match self.content { SectionContent::Unloaded => { return Err(Error::SyncingUnloadedSection); }, SectionContent::Relocations(_) => { self.header.entsize = Relocation::entsize(eh) as u64; } SectionContent::Symbols(ref mut vv) => { for (i, sym) in vv.iter().enumerate() { if sym.bind == types::SymbolBind::GLOBAL { self.header.info = i as u32; break; } } for v in vv { v.sync(linked.as_mut().map(|r| &mut **r), eh)?; } self.header.entsize = Symbol::entsize(eh) as u64; } SectionContent::Dynamic(ref mut vv) => { for v in vv { v.sync(linked.as_mut().map(|r| &mut **r), eh)?; } self.header.entsize = Dynamic::entsize(eh) as u64; } SectionContent::Strtab(_) => { self.header.entsize = Strtab::entsize(eh) as u64; } SectionContent::None | SectionContent::Raw(_) => {} } if self.header.shtype != types::SectionType::NOBITS { self.header.size = self.size(eh) as u64; } Ok(()) } pub fn from_reader<T>( &mut self, mut io: T, linked: Option<&Section>, eh: &Header, ) -> Result<(), Error> where T: Read + Seek { match self.content { SectionContent::Unloaded => {}, _ => return Ok(()), }; if self.header.shtype == types::SectionType::NOBITS { self.content = SectionContent::None; return Ok(()); }; io.seek(SeekFrom::Start(self.header.offset))?; let mut bb = vec![0; self.header.size as usize]; io.read_exact(&mut bb)?; let linked = linked.map(|s|&s.content); self.content = match self.header.shtype { types::SectionType::NOBITS => { unreachable!(); }, types::SectionType::STRTAB => { let io = bb.as_slice(); Strtab::from_reader(io, linked, eh)? } types::SectionType::RELA => { let io = bb.as_slice(); Relocation::from_reader(io, linked, eh)? } types::SectionType::SYMTAB | types::SectionType::DYNSYM => { let io = bb.as_slice(); Symbol::from_reader(io, linked, eh)? } types::SectionType::DYNAMIC => { let io = bb.as_slice(); Dynamic::from_reader(io, linked, eh)? } _ => { SectionContent::Raw(bb) } }; Ok(()) } pub fn to_writer<R>( &self, mut io: R, eh: &Header, ) -> Result<(), Error> where R: Write + Seek { match self.content { SectionContent::Unloaded => return Ok(()), _ => {}, }; io.seek(SeekFrom::Start(self.header.offset))?; let rs = match &self.content { &SectionContent::Unloaded => { return Err(Error::WritingUnloadedSection); }, &SectionContent::Relocations(ref vv) => { let mut rs = 0; for v in vv { rs += v.to_writer(&mut io, eh)?; } rs } &SectionContent::Symbols(ref vv) => { let mut rs = 0; for v in vv { rs += v.to_writer(&mut io, eh)?; } rs } &SectionContent::Dynamic(ref vv) => { let mut rs = 0; for v in vv { rs += v.to_writer(&mut io, eh)?; } rs } &SectionContent::Strtab(ref v) => { v.to_writer(&mut io, eh)? } &SectionContent::None => { 0 }, &SectionContent::Raw(ref raw) => { io.write(&raw)? } }; assert_eq!( io.seek(SeekFrom::Current(0))?, self.header.offset + self.content.size(eh) as u64, "writing {} with header.size {} and content.size {} returned a written size {}", String::from_utf8_lossy(&self.name), self.content.size(eh), self.header.size, rs ); Ok(()) } }