编写一段rust程序实现PE文件的操作，并修改 a.exe 的 .text 区段名为 .mytext

use std::fs;
use std::io;
use std::io::Write;
use std::mem;
use std::slice;

#[repr(C)]
struct IMAGE_DOS_HEADER {
    e_magic: u16,
    e_cblp: u16,
    e_cp: u16,
    e_crlc: u16,
    e_cparhdr: u16,
    e_minalloc: u16,
    e_maxalloc: u16,
    e_ss: u16,
    e_sp: u16,
    e_csum: u16,
    e_ip: u16,
    e_cs: u16,
    e_lfarlc: u16,
    e_ovno: u16,
    e_res: [u16; 4],
    e_oemid: u16,
    e_oeminfo: u16,
    e_res2: [u16; 10],
    e_lfanew: u32,
}

#[repr(C)]
struct IMAGE_FILE_HEADER {
    Machine: u16,
    NumberOfSections: u16,
    TimeDateStamp: u32,
    PointerToSymbolTable: u32,
    NumberOfSymbols: u32,
    SizeOfOptionalHeader: u16,
    Characteristics: u16,
}

#[repr(C)]
struct IMAGE_SECTION_HEADER {
    Name: [u8; 8],
    VirtualSize: u32,
    VirtualAddress: u32,
    SizeOfRawData: u32,
    PointerToRawData: u32,
    PointerToRelocations: u32,
    PointerToLinenumbers: u32,
    NumberOfRelocations: u16,
    NumberOfLinenumbers: u16,
    Characteristics: u32,
}

fn main() -> io::Result<()> {
    let mut file = fs::OpenOptions::new().read(true).write(true).open("a.exe")?;
    let size = file.metadata()?.len();
    let mut buffer = vec![0; size as usize];
    file.read_exact(&mut buffer)?;

    let dos_header: &mut IMAGE_DOS_HEADER = unsafe { mem::transmute(&mut buffer[0]) };
    let nt_header_offset = dos_header.e_lfanew as usize;

    let file_header: &mut IMAGE_FILE_HEADER =
        unsafe { mem::transmute(&mut buffer[nt_header_offset + 4]) };
    let section_header_offset = nt_header_offset + mem::size_of::<IMAGE_FILE_HEADER>();

    let section_header_size = mem::size_of::<IMAGE_SECTION_HEADER>();
    let section_count = file_header.NumberOfSections as usize;
    for i in 0..section_count {
        let section_header = unsafe {
            mem::transmute::<*mut u8, *mut IMAGE_SECTION_HEADER>(
                &mut buffer[section_header_offset + i * section_header_size],
            )
        };
        let name = unsafe { slice::from_raw_parts_mut(section_header.Name.as_mut_ptr(), 8) };
        if name == b".text\0\0\0" {
            let mytext = b".mytext\0";
            name.copy_from_slice(mytext);
            section_header.VirtualAddress = 0x2000; // 修改 .mytext 的虚拟地址
            section_header.PointerToRawData = 0x400; // 修改 .mytext 的文件偏移
        }
    }

    file.write_all(&buffer)?;

    Ok(())
}