# program.rs - source
Source of the Rust file `/home/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/xmas-elf-0.7.0/src/program.rs`.
Keywords: rust, rustlang, rust-lang

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    use {ElfFile, P32, P64};
    use zero::{read, read_array, Pod};
    use header::{Class, Header};
    use dynamic::Dynamic;
    use sections::NoteHeader;

    use core::mem;
    use core::fmt;

    pub fn parse_program_header<'a>(input: &'a [u8],
                                    header: Header<'a>,
                                    index: u16)
                                    -> Result<ProgramHeader<'a>, &'static str> {
        let pt2 = &header.pt2;
        if !(index < pt2.ph_count() && pt2.ph_offset() > 0 && pt2.ph_entry_size() > 0) {
            return Err("There are no program headers in this file")
        }

        let start = pt2.ph_offset() as usize + index as usize * pt2.ph_entry_size() as usize;
        let end = start + pt2.ph_entry_size() as usize;

        match header.pt1.class() {
            Class::ThirtyTwo => {
                Ok(ProgramHeader::Ph32(read(&input[start..end])))
            }
            Class::SixtyFour => {
                Ok(ProgramHeader::Ph64(read(&input[start..end])))
            }
            Class::None | Class::Other(_) => unreachable!(),
        }
    }

    #[derive(Debug)]
    pub struct ProgramIter<'b, 'a: 'b> {
        pub file: &'b ElfFile<'a>,
        pub next_index: u16,
    }

    impl<'b, 'a> Iterator for ProgramIter<'b, 'a> {
        type Item = ProgramHeader<'a>;

        fn next(&mut self) -> Option<Self::Item> {
            let count = self.file.header.pt2.ph_count();
            if self.next_index >= count {
                return None;
            }

            let result = self.file.program_header(self.next_index);
            self.next_index += 1;
            result.ok()
        }
    }

    #[derive(Copy, Clone, Debug)]
    pub enum ProgramHeader<'a> {
        Ph32(&'a ProgramHeader32),
        Ph64(&'a ProgramHeader64),
    }

    #[derive(Copy, Clone, Debug, Default)]
    #[repr(C)]
    pub struct ProgramHeader32 {
        pub type_: Type_,
        pub offset: u32,
        pub virtual_addr: u32,
        pub physical_addr: u32,
        pub file_size: u32,
        pub mem_size: u32,
        pub flags: Flags,
        pub align: u32,
    }

    unsafe impl Pod for ProgramHeader32 {}

    #[derive(Copy, Clone, Debug, Default)]
    #[repr(C)]
    pub struct ProgramHeader64 {
        pub type_: Type_,
        pub flags: Flags,
        pub offset: u64,
        pub virtual_addr: u64,
        pub physical_addr: u64,
        pub file_size: u64,
        pub mem_size: u64,
        pub align: u64,
    }

    unsafe impl Pod for ProgramHeader64 {}

    macro_rules! getter {
        ($name: ident, $typ: ident) => {
            pub fn $name(&self) -> $typ {
                match *self {
                    ProgramHeader::Ph32(h) => h.$name as $typ,
                    ProgramHeader::Ph64(h) => h.$name as $typ,
                }
            }
        }
    }

    impl<'a> ProgramHeader<'a> {
        pub fn get_type(&self) -> Result<Type, &'static str> {
            match *self {
                ProgramHeader::Ph32(ph) => ph.get_type(),
                ProgramHeader::Ph64(ph) => ph.get_type(),
            }
        }

        pub fn get_data(&self, elf_file: &ElfFile<'a>) -> Result<SegmentData<'a>, &'static str> {
            match *self {
                ProgramHeader::Ph32(ph) => ph.get_data(elf_file),
                ProgramHeader::Ph64(ph) => ph.get_data(elf_file),
            }
        }

        getter!(align, u64);
        getter!(file_size, u64);
        getter!(mem_size, u64);
        getter!(offset, u64);
        getter!(physical_addr, u64);
        getter!(virtual_addr, u64);
        getter!(flags, Flags);
    }

    impl<'a> fmt::Display for ProgramHeader<'a> {
        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
            match *self {
                ProgramHeader::Ph32(ph) => ph.fmt(f),
                ProgramHeader::Ph64(ph) => ph.fmt(f),
            }
        }
    }
    macro_rules! ph_impl {
        ($ph: ident) => {
            impl $ph {
                pub fn get_type(&self) -> Result<Type, &'static str> {
                    self.type_.as_type()
                }

                pub fn get_data<'a>(&self, elf_file: &ElfFile<'a>) -> Result<SegmentData<'a>, &'static str> {
                    self.get_type().map(|typ| match typ {
                        Type::Null => SegmentData::Empty,
                        Type::Load | Type::Interp | Type::ShLib | Type::Phdr | Type::Tls |
                        Type::GnuRelro | Type::OsSpecific(_) | Type::ProcessorSpecific(_) => {
                            SegmentData::Undefined(self.raw_data(elf_file))
                        }
                        Type::Dynamic => {
                            let data = self.raw_data(elf_file);
                            match elf_file.header.pt1.class() {
                                Class::ThirtyTwo => SegmentData::Dynamic32(read_array(data)),
                                Class::SixtyFour => SegmentData::Dynamic64(read_array(data)),
                                Class::None | Class::Other(_) => unreachable!(),
                            }
                        }
                        Type::Note => {
                            let data = self.raw_data(elf_file);
                            match elf_file.header.pt1.class() {
                                Class::ThirtyTwo => unimplemented!(),
                                Class::SixtyFour => {
                                    let header: &'a NoteHeader = read(&data[0..12]);
                                    let index = &data[12..];
                                    SegmentData::Note64(header, index)
                                }
                                Class::None | Class::Other(_) => unreachable!(),
                            }
                        }
                    })
                }

                pub fn raw_data<'a>(&self, elf_file: &ElfFile<'a>) -> &'a [u8] {
                    assert!(self.get_type().map(|typ| typ != Type::Null).unwrap_or(false));
                    &elf_file.input[self.offset as usize..(self.offset + self.file_size) as usize]
                }
            }

            impl fmt::Display for $ph {
                fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
                    try!(writeln!(f, "Program header:"));
                    try!(writeln!(f, "    type:             {:?}", self.get_type()));
                    try!(writeln!(f, "    flags:            {}", self.flags));
                    try!(writeln!(f, "    offset:           {:#x}", self.offset));
                    try!(writeln!(f, "    virtual address:  {:#x}", self.virtual_addr));
                    try!(writeln!(f, "    physical address: {:#x}", self.physical_addr));
                    try!(writeln!(f, "    file size:        {:#x}", self.file_size));
                    try!(writeln!(f, "    memory size:      {:#x}", self.mem_size));
                    try!(writeln!(f, "    align:            {:#x}", self.align));
                    Ok(())
                }
            }
        }
    }

    ph_impl!(ProgramHeader32);
    ph_impl!(ProgramHeader64);

    #[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
    pub struct Flags(pub u32);

    impl Flags {
        pub fn is_execute(&self) -> bool {
            self.0 & FLAG_X == FLAG_X
        }

        pub fn is_write(&self) -> bool {
            self.0 & FLAG_W == FLAG_W
        }

        pub fn is_read(&self) -> bool {
            self.0 & FLAG_R == FLAG_R
        }
    }

    impl fmt::Display for Flags {
        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
            write!(f, "{}{}{}",
                   if self.0 & FLAG_X == FLAG_X { 'X' } else { ' ' },
                   if self.0 & FLAG_W == FLAG_W { 'W' } else { ' ' },
                   if self.0 & FLAG_R == FLAG_R { 'R' } else { ' ' })
        }
    }

    impl fmt::LowerHex for Flags {
        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
            let val = self.0;

            write!(f, "{:#x}", val) // delegate to i32's implementation
        }
    }

    #[derive(Copy, Clone, Default)]
    pub struct Type_(u32);

    #[derive(Copy, Clone, Debug, Eq, PartialEq)]
    pub enum Type {
        Null,
        Load,
        Dynamic,
        Interp,
        Note,
        ShLib,
        Phdr,
        Tls,
        GnuRelro,
        OsSpecific(u32),
        ProcessorSpecific(u32),
    }

    impl Type_ {
        fn as_type(&self) -> Result<Type, &'static str> {
            match self.0 {
                0 => Ok(Type::Null),
                1 => Ok(Type::Load),
                2 => Ok(Type::Dynamic),
                3 => Ok(Type::Interp),
                4 => Ok(Type::Note),
                5 => Ok(Type::ShLib),
                6 => Ok(Type::Phdr),
                7 => Ok(Type::Tls),
                TYPE_GNU_RELRO => Ok(Type::GnuRelro),
                t if t >= TYPE_LOOS && t <= TYPE_HIOS => Ok(Type::OsSpecific(t)),
                t if t >= TYPE_LOPROC && t <= TYPE_HIPROC => Ok(Type::ProcessorSpecific(t)),
                _ => Err("Invalid type"),
            }
        }
    }

    impl fmt::Debug for Type_ {
        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
            self.as_type().fmt(f)
        }
    }

    #[derive(Debug)]
    pub enum SegmentData<'a> {
        Empty,
        Undefined(&'a [u8]),
        Dynamic32(&'a [Dynamic<P32>]),
        Dynamic64(&'a [Dynamic<P64>]),
        // Note32 uses 4-byte words, which I'm not sure how to manage.
        // The pointer is to the start of the name field in the note.
        Note64(&'a NoteHeader, &'a [u8]), /* TODO Interp and Phdr should probably be defined some how, but I can't find the details. */
    }

    pub const TYPE_LOOS: u32 = 0x60000000;
    pub const TYPE_HIOS: u32 = 0x6fffffff;
    pub const TYPE_LOPROC: u32 = 0x70000000;
    pub const TYPE_HIPROC: u32 = 0x7fffffff;
    pub const TYPE_GNU_RELRO: u32 = TYPE_LOOS + 0x474e552;

    pub const FLAG_X: u32 = 0x1;
    pub const FLAG_W: u32 = 0x2;
    pub const FLAG_R: u32 = 0x4;
    pub const FLAG_MASKOS: u32 = 0x0ff00000;
    pub const FLAG_MASKPROC: u32 = 0xf0000000;

    pub fn sanity_check<'a>(ph: ProgramHeader<'a>, elf_file: &ElfFile<'a>) -> Result<(), &'static str> {
        let header = elf_file.header;
        match ph {
            ProgramHeader::Ph32(ph) => {
                check!(mem::size_of_val(ph) == header.pt2.ph_entry_size() as usize,
                       "program header size mismatch");
                check!(((ph.offset + ph.file_size) as usize) < elf_file.input.len(),
                       "entry point out of range");
                check!(try!(ph.get_type()) != Type::ShLib, "Shouldn't use ShLib");
                if ph.align > 1 {
                    check!(ph.virtual_addr % ph.align == ph.offset % ph.align,
                           "Invalid combination of virtual_addr, offset, and align");
                }
            }
            ProgramHeader::Ph64(ph) => {
                check!(mem::size_of_val(ph) == header.pt2.ph_entry_size() as usize,
                       "program header size mismatch");
                check!(((ph.offset + ph.file_size) as usize) < elf_file.input.len(),
                       "entry point out of range");
                check!(try!(ph.get_type()) != Type::ShLib, "Shouldn't use ShLib");
                if ph.align > 1 {
                    // println!("{} {} {}", ph.virtual_addr, ph.offset, ph.align);
                    check!(ph.virtual_addr % ph.align == ph.offset % ph.align,
                           "Invalid combination of virtual_addr, offset, and align");
                }
            }
        }

        Ok(())
    }