Add support for endianness

CMakeLists.txt

@@ -77,6 +77,7 @@ set(LIBLIEF_SOURCE_FILES
   "${CMAKE_CURRENT_SOURCE_DIR}/src/Visitor.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/src/BinaryStream/BinaryStream.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/src/BinaryStream/VectorStream.cpp"
+  "${CMAKE_CURRENT_SOURCE_DIR}/src/BinaryStream/Convert.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/src/visitors/hash.cpp")
 
 
@@ -102,6 +103,7 @@ set(LIEF_INC_FILES
   "${CMAKE_CURRENT_SOURCE_DIR}/include/LIEF/visitor_macros.hpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/include/LIEF/BinaryStream/BinaryStream.hpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/include/LIEF/BinaryStream/VectorStream.hpp"
+  "${CMAKE_CURRENT_SOURCE_DIR}/include/LIEF/BinaryStream/Convert.hpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/src/frozen.hpp"
 )
 

include/LIEF/BinaryStream/BinaryStream.hpp

@@ -21,6 +21,9 @@
 #include <vector>
 #include <istream>
 #include <utility>
+#include <memory>
+
+#include "LIEF/BinaryStream/Convert.hpp"
 
 class BinaryStream {
   public:
@@ -79,9 +82,26 @@ class BinaryStream {
 
   size_t align(size_t align_on) const;
 
+  /* Read an integer value and adjust endianness as needed */
+  template<typename T>
+  T read_conv() const;
+
+  /* Read an array of values and adjust endianness as needed */
+  template<typename T>
+  std::unique_ptr<T[]> read_conv_array(size_t size, bool check = true) const;
+
+  template<typename T>
+  T peek_conv(size_t offset) const;
+
+  template<typename T>
+  std::unique_ptr<T[]> peek_conv_array(size_t offset, size_t size, bool check = true) const;
+
+  void set_endian_swap(bool swap);
+
   protected:
   virtual const void* read_at(uint64_t offset, uint64_t size, bool throw_error = true) const = 0;
   mutable size_t pos_{0};
+  bool endian_swap_{false};
 };
 
 
@@ -167,5 +187,62 @@ const T* BinaryStream::read_array(size_t size, bool check) const {
 }
 
 
+template<typename T>
+T BinaryStream::read_conv(void) const {
+  T t = this->read<T>();
+  if (this->endian_swap_) {
+    LIEF::Convert::swap_endian<T>(& t);
+  }
+  return t;
+}
+
+
+template<typename T>
+std::unique_ptr<T[]> BinaryStream::read_conv_array(size_t size, bool check) const {
+  const T *t = this->read_array<T>(size, check);
+
+  if (t == nullptr) {
+	  return nullptr;
+  }
+
+  std::unique_ptr<T[]> uptr(new T[size]);
+
+  for (size_t i = 0; i < size; i++) {
+    uptr[i] = t[i];
+    if (this->endian_swap_) {
+        LIEF::Convert::swap_endian<T>(& uptr[i]);
+    } /* else no conversion, just provide the copied data */
+  }
+  return uptr;
+}
+
+template<class T>
+T BinaryStream::peek_conv(size_t offset) const {
+  T t = this->peek<T>(offset);
+
+  if (this->endian_swap_) {
+    LIEF::Convert::swap_endian(&t);
+  }
+  return t;
+}
+
+template<typename T>
+std::unique_ptr<T[]> BinaryStream::peek_conv_array(size_t offset, size_t size, bool check) const {
+  const T *t = this->peek_array<T>(offset, size, check);
+
+  if (t == nullptr) {
+	  return nullptr;
+  }
+
+  std::unique_ptr<T[]> uptr(new T[size]);
+
+  for (size_t i = 0; i < size; i++) {
+    uptr[i] = t[i];
+    if (this->endian_swap_) {
+      LIEF::Convert::swap_endian<T>(& uptr[i]);
+    } /* else no conversion, just provide the copied data */
+  }
+  return uptr;
+}
 
 #endif

include/LIEF/BinaryStream/Convert.hpp

@@ -0,0 +1,12 @@
+#ifndef LIEF_CONVERT_H_
+#define LIEF_CONVERT_H_
+
+namespace LIEF {
+namespace Convert {
+
+template<typename X>
+void swap_endian(X* x);
+}
+}
+
+#endif // LIEF_CONVERT_H_

include/LIEF/ELF/Parser.hpp

@@ -96,6 +96,8 @@ class LIEF_API Parser : public LIEF::Parser {
 
     void init(const std::string& name = "");
 
+    bool should_swap(void) const;
+
     // map, dynamic_symbol.version <----> symbol_version
     // symbol_version comes from symbol_version table
     void link_symbol_version(void);

src/BinaryStream/BinaryStream.cpp

@@ -218,3 +218,7 @@ std::string BinaryStream::read_mutf8(size_t maxsize) const {
   return u8str_clean;
 }
 
+void BinaryStream::set_endian_swap(bool swap) {
+  this->endian_swap_ = swap;
+}
+

src/BinaryStream/Convert.cpp

@@ -0,0 +1,23 @@
+#include "LIEF/BinaryStream/Convert.hpp"
+#include "LIEF/BinaryStream/BinaryStream.hpp"
+
+/* In place conversions for BinaryStream/VectorStream data */
+
+namespace LIEF {
+namespace Convert {
+
+template<typename T>
+void swap_endian(T *v) {
+  static_assert(std::is_integral<T>::value, "Only integer types can use generic endian swap");
+  *v = BinaryStream::swap_endian(*v);
+}
+
+/*
+ * Force instantiation of template for types used
+ */
+template void swap_endian<uint16_t>(uint16_t *v);
+template void swap_endian<uint32_t>(uint32_t *v);
+template void swap_endian<uint64_t>(uint64_t *v);
+
+}
+}

src/ELF/CMakeLists.txt

@@ -15,6 +15,7 @@ configure_file(
 )
 
 set(LIEF_ELF_SRC
+  "${CMAKE_CURRENT_LIST_DIR}/Convert.cpp"
   "${CMAKE_CURRENT_LIST_DIR}/DynamicEntryArray.cpp"
   "${CMAKE_CURRENT_LIST_DIR}/utils.cpp"
   "${CMAKE_CURRENT_LIST_DIR}/SymbolVersionRequirement.cpp"