Package ghidra.app.util.bin.format.elf

Class ElfSectionHeader

java.lang.Object
ghidra.app.util.bin.format.elf.ElfSectionHeader
All Implemented Interfaces:
MemoryLoadable, StructConverter
public class ElfSectionHeader extends Object implements StructConverter, MemoryLoadable
A class to represent the Elf32_Shdr data structure. 
 typedef  int32_t  Elf32_Sword;
 typedef uint32_t  Elf32_Word;
 typedef uint32_t  Elf32_Addr;
 
 typedef struct {
     Elf32_Word    sh_name;       //Section name (string tbl index)
     Elf32_Word    sh_type;       //Section type
     Elf32_Word    sh_flags;      //Section flags
     Elf32_Addr    sh_addr;       //Section virtual addr at execution
     Elf32_Off     sh_offset;     //Section file offset
     Elf32_Word    sh_size;       //Section size in bytes
     Elf32_Word    sh_link;       //Link to another section
     Elf32_Word    sh_info;       //Additional section information
     Elf32_Word    sh_addralign;  //Section alignment
     Elf32_Word    sh_entsize;    //Entry size if section holds table *
 } Elf32_Shdr;
 
 typedef  uint32_t  Elf64_Word;
 typedef  uint64_t  Elf64_Xword;
 typedef  uint64_t  Elf64_Addr;
 typedef  uint64_t  Elf64_Off;
 
 typedef struct {
     Elf64_Word    sh_name;       //Section name (string tbl index)
     Elf64_Word    sh_type;       //Section type
     Elf64_Xword   sh_flags;      //Section flags
     Elf64_Addr    sh_addr;       //Section virtual addr at execution
     Elf64_Off     sh_offset;     //Section file offset
     Elf64_Xword   sh_size;       //Section size in bytes
     Elf64_Word    sh_link;       //Link to another section
     Elf64_Word    sh_info;       //Additional section information
     Elf64_Xword   sh_addralign;  //Section alignment
     Elf64_Xword   sh_entsize;    //Entry size if section holds table *
 } Elf64_Shdr;

  • Constructor Details Link icon

    • ElfSectionHeader Link icon

      public ElfSectionHeader(BinaryReader reader, ElfHeader header) throws IOException
      Construct ElfSectionHeader
      Parameters:
      reader - dedicated reader instance positioned to the start of the program header data. (the reader supplied will be retained and altered).
      header - ELF header
      Throws:
      IOException - if an IO error occurs during parse

  • Method Details Link icon

    • getElfHeader Link icon

      public ElfHeader getElfHeader()
      Return ElfHeader associated with this section
      Returns:
      ElfHeader

    • getAddress Link icon

      public long getAddress()
      If the section will appear in the memory image of a process, this member gives the address at which the section's first byte should reside. Otherwise, the member contains 0.
      Returns:
      the address of the section in memory

    • getAddressAlignment Link icon

      public long getAddressAlignment()
      Some sections have address alignment constraints. For example, if a section holds a doubleword, the system must ensure doubleword alignment for the entire section. That is, the value of sh_addr must be congruent to 0, modulo the value of sh_addralign. Currently, only 0 and positive integral powers of two are allowed. Values 0 and 1 mean the section has no alignment constraints.
      Returns:
      the section address alignment constraints

    • getEntrySize Link icon

      public long getEntrySize()
      Some sections hold a table of fixed-size entries, such as a symbol table. For such a section, this member gives the size in bytes of each entry. The member contains 0 if the section does not hold a table of fixed-size entries.
      Returns:
      the section entry size

    • getFlags Link icon

      public long getFlags()
      Sections support 1-bit flags that describe miscellaneous attributes. Flag definitions appear aove.
      Returns:
      the section flags

    • isWritable Link icon

      public boolean isWritable()
      Returns true if this section is writable.
      Returns:
      true if this section is writable.

    • isExecutable Link icon

      public boolean isExecutable()
      Returns true if this section is executable.
      Returns:
      true if this section is executable.

    • isAlloc Link icon

      public boolean isAlloc()
      Returns true if this section is allocated (e.g., SHF_ALLOC is set)
      Returns:
      true if this section is allocated.

    • isCompressed Link icon

      public boolean isCompressed()
      Returns true if this section is compressed in a supported manner. This does NOT include sections that carry compressed data, such as ".zdebuginfo" type sections.
      Returns:
      true if the section was compressed and needs to be decompressed, false if normal section

    • getInfo Link icon

      public int getInfo()
      This member holds extra information, whose interpretation depends on the section type. If sh_type is SHT_REL or SHT_RELA, then sh_info holds the section header index of the section to which the relocation applies. If sh_type is SHT_SYMTAB or SHT_DYNSYM, then sh_info holds one greater than the symbol table index of the last local symbol (binding STB_LOCAL).
      Returns:
      the section header info

    • getLink Link icon

      public int getLink()
      This member holds extra information, whose interpretation depends on the section type. If sh_type is SHT_SYMTAB, SHT_DYNSYM, or SHT_DYNAMIC, then sh_link holds the section header table index of its associated string table. If sh_type is SHT_REL, SHT_RELA, or SHT_HASH sh_link holds the section header index of the associated symbol table.
      Returns:
      the section header link

    • getName Link icon

      public int getName()
      An index into the section header string table section, giving the location of a null-terminated string which is the name of this section.
      Returns:
      the index of the section name

    • getNameAsString Link icon

      public String getNameAsString()
      Returns the actual string name for this section. The section only stores an byte index into the string table where the name string is located.
      Returns:
      the actual string name for this section

    • toString Link icon

      public String toString()
      Overrides:
      toString in class Object
      See Also:

    • getOffset Link icon

      public long getOffset()
      The byte offset from the beginning of the file to the first byte in the section. One section type, SHT_NOBITS described below, occupies no space in the file, and its sh_offset member locates the conceptual placement in the file.
      Returns:
      byte offset from the beginning of the file to the first byte in the section

    • isInvalidOffset Link icon

      public boolean isInvalidOffset()
      Returns true if this section header's offset is invalid.
      Returns:
      true if this section header's offset is invalid

    • getSize Link icon

      public long getSize()
      This member gives the section's size in bytes. Unless the section type is SHT_NOBITS, the section occupies sh_size bytes in the file. A section of type SHT_NOBITS may have a non-zero size, but it occupies no space in the file.
      Returns:
      the section's size in bytes

    • getLogicalSize Link icon

      public long getLogicalSize()
      Returns the logical size of this section, possibly affected by compression.
      Returns:
      logical size of this section, see getSize()

    • hasFilteredLoadInputStream Link icon

      public boolean hasFilteredLoadInputStream(ElfLoadHelper elfLoadHelper, Address start)
      Description copied from interface: MemoryLoadable
      Determine if the use of input stream decompression or filtering via an extension is neccessary. If this method returns true and a filtered stream is required and will prevent the use of a direct mapping to file bytes for affected memory regions.
      Specified by:
      hasFilteredLoadInputStream in interface MemoryLoadable
      Parameters:
      elfLoadHelper - ELF load helper
      start - memory load address
      Returns:
      true if the use of a filtered input stream is required

    • getFilteredLoadInputStream Link icon

      public InputStream getFilteredLoadInputStream(ElfLoadHelper elfLoadHelper, Address start, long dataLength, BiConsumer<String,Throwable> errorConsumer) throws IOException
      Description copied from interface: MemoryLoadable
      Return filtered InputStream for loading a memory block (includes non-loaded OTHER blocks). See MemoryLoadable.hasFilteredLoadInputStream(ElfLoadHelper, Address).
      Specified by:
      getFilteredLoadInputStream in interface MemoryLoadable
      Parameters:
      elfLoadHelper - ELF load helper
      start - memory load address
      dataLength - the in-memory data length in bytes (actual bytes read from dataInput may be more)
      errorConsumer - consumer that will accept errors which may occur during stream decompression, if null Msg.error() will be used.
      Returns:
      filtered input stream or original input stream
      Throws:
      IOException - if error initializing filtered input stream

    • getRawInputStream Link icon

      public InputStream getRawInputStream() throws IOException
      Description copied from interface: MemoryLoadable
      Returns raw data input stream associated with this loadable object..
      Specified by:
      getRawInputStream in interface MemoryLoadable
      Returns:
      raw data input stream associated with this loadable object.
      Throws:
      IOException - if error initializing input stream

    • getType Link icon

      public int getType()
      This member categorizes the section's contents and semantics.
      Returns:
      the section's contents and semantics

    • getTypeAsString Link icon

      public String getTypeAsString()
      Get header type as string. ElfSectionHeaderType name will be returned if know, otherwise a numeric name of the form "SHT_0x12345678" will be returned.
      Returns:
      header type as string

    • getReader Link icon

      public BinaryReader getReader()
      Returns the binary reader.
      Returns:
      the binary reader

    • setAddress Link icon

      public void setAddress(long addr)
      Sets the start address of this section.
      Parameters:
      addr - the new start address of this section

    • toDataType Link icon

      public DataType toDataType()
      Description copied from interface: StructConverter
      Returns a structure datatype representing the contents of the implementor of this interface.

      For example, given: 

       class A {
     int foo;
     double bar;
 }

      The return value should be a structure data type with two data type components; an INT and a DOUBLE. The structure should contain field names and, if possible, field comments.

      Specified by:
      toDataType in interface StructConverter
      Returns:
      returns a structure datatype representing the implementor of this interface
      See Also:

    • hashCode Link icon

      public int hashCode()
      Overrides:
      hashCode in class Object

    • equals Link icon

      public boolean equals(Object obj)
      Overrides:
      equals in class Object