/*
 * Process Hacker
 * 
 * Copyright (C) 2008 wj32 
 * 
 * Descriptions from the PE/COFF specification v8 from Microsoft.
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;

namespace ProcessHacker.PE
{
    /// <summary>
    /// Represents a section header.
    /// </summary>
    public class SectionHeader
    {
        public SectionHeader(BinaryReader br)
        {
            int i = 0;

            while (i < 8)
            {
                byte b = br.ReadByte();

                if (b != 0)
                    Name += (char)b;

                i++;    
            }

            this.VirtualSize = br.ReadUInt32();
            this.VirtualAddress = br.ReadUInt32();
            this.SizeOfRawData = br.ReadUInt32();
            this.PointerToRawData = br.ReadUInt32();
            this.PointerToRelocations = br.ReadUInt32();
            this.PointerToLinenumbers = br.ReadUInt32();
            this.NumberOfRelocations = br.ReadUInt16();
            this.NumberOfLinenumbers = br.ReadUInt16();
            this.Characteristics = (SectionFlags)br.ReadUInt32();
        }

        /// <summary>
        /// An 8-byte, null-padded UTF-8 encoded string. If the string 
        /// is exactly 8 characters long, there is no terminating null. 
        /// For longer names, this field contains a slash (/) that is 
        /// followed by an ASCII representation of a decimal number that 
        /// is an offset into the string table. Executable images do not 
        /// use a string table and do not support section names longer 
        /// than 8 characters. Long names in object files are truncated 
        /// if they are emitted to an executable file.
        /// </summary>
        public string Name;

        /// <summary>
        /// The total size of the section when loaded into memory. If this 
        /// value is greater than SizeOfRawData, the section is zero-padded. 
        /// This field is valid only for executable images and should be set 
        /// to zero for object files.
        /// </summary>
        public uint VirtualSize;

        /// <summary>
        /// For executable images, the address of the first byte of the 
        /// section relative to the image base when the section is loaded 
        /// into memory. For object files, this field is the address of 
        /// the first byte before relocation is applied; for simplicity, 
        /// compilers should set this to zero. Otherwise, it is an arbitrary 
        /// value that is subtracted from offsets during relocation.
        /// </summary>
        public uint VirtualAddress;

        /// <summary>
        /// The size of the section (for object files) or the size of the 
        /// initialized data on disk (for image files). For executable 
        /// images, this must be a multiple of FileAlignment from the 
        /// optional header. If this is less than VirtualSize, the remainder 
        /// of the section is zero-filled. Because the SizeOfRawData field 
        /// is rounded but the VirtualSize field is not, it is possible for 
        /// SizeOfRawData to be greater than VirtualSize as well. When a 
        /// section contains only uninitialized data, this field should be zero.
        /// </summary>
        public uint SizeOfRawData;

        /// <summary>
        /// The file pointer to the first page of the section within the 
        /// COFF file. For executable images, this must be a multiple of 
        /// FileAlignment from the optional header. For object files, the 
        /// value should be aligned on a 4 byte boundary for best performance. 
        /// When a section contains only uninitialized data, this field should 
        /// be zero.
        /// </summary>
        public uint PointerToRawData;

        /// <summary>
        /// The file pointer to the beginning of relocation entries for the 
        /// section. This is set to zero for executable images or if there are 
        /// no relocations.
        /// </summary>
        public uint PointerToRelocations;

        /// <summary>
        /// The file pointer to the beginning of line-number entries for the 
        /// section. This is set to zero if there are no COFF line numbers. 
        /// This value should be zero for an image because COFF debugging 
        /// information is deprecated.
        /// </summary>
        public uint PointerToLinenumbers;

        /// <summary>
        /// The number of relocation entries for the section. This is set to 
        /// zero for executable images.
        /// </summary>
        public ushort NumberOfRelocations;

        /// <summary>
        /// The number of line-number entries for the section. This value 
        /// should be zero for an image because COFF debugging information is 
        /// deprecated.
        /// </summary>
        public ushort NumberOfLinenumbers;

        /// <summary>
        /// The flags that describe the characteristics of the section.
        /// </summary>
        public SectionFlags Characteristics;
    }
}