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// Copyright (c) 2006, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// macho_walker.h: Iterate over the load commands in a mach-o file
//
// Author: Dan Waylonis
#ifndef COMMON_MAC_MACHO_WALKER_H__
#define COMMON_MAC_MACHO_WALKER_H__
#include <mach-o/loader.h>
#include <sys/types.h>
namespace MacFileUtilities {
class MachoWalker {
public:
// A callback function executed when a new load command is read. If no
// further processing of load commands is desired, return false. Otherwise,
// return true.
// |cmd| is the current command, and |offset| is the location relative to the
// beginning of the file (not header) where the command was read. If |swap|
// is set, then any command data (other than the returned load_command) should
// be swapped when read
typedef bool (*LoadCommandCallback)(MachoWalker *walker, load_command *cmd,
off_t offset, bool swap, void *context);
MachoWalker(const char *path, LoadCommandCallback callback, void *context);
MachoWalker(int file_descriptor, LoadCommandCallback callback, void *context);
~MachoWalker();
// Begin walking the header for |cpu_type|. If |cpu_type| is 0, then the
// native cpu type is used. Otherwise, accepted values are listed in
// /usr/include/mach/machine.h (e.g., CPU_TYPE_X86 or CPU_TYPE_POWERPC).
// Returns false if opening the file failed or if the |cpu_type| is not
// present in the file.
bool WalkHeader(int cpu_type);
// Locate (if any) the header offset for |cpu_type| and return in |offset|.
// Return true if found, false otherwise.
bool FindHeader(int cpu_type, off_t &offset);
// Read |size| bytes from the opened file at |offset| into |buffer|
bool ReadBytes(void *buffer, size_t size, off_t offset);
// Return the current header and header offset
bool CurrentHeader(struct mach_header_64 *header, off_t *offset);
private:
// Validate the |cpu_type|
int ValidateCPUType(int cpu_type);
// Process an individual header starting at |offset| from the start of the
// file. Return true if successful, false otherwise.
bool WalkHeaderAtOffset(off_t offset);
bool WalkHeader64AtOffset(off_t offset);
// Bottleneck for walking the load commands
bool WalkHeaderCore(off_t offset, uint32_t number_of_commands, bool swap);
// File descriptor to the opened file
int file_;
// User specified callback & context
LoadCommandCallback callback_;
void *callback_context_;
// Current header, size, and offset. The mach_header_64 is used for both
// 32-bit and 64-bit headers because they only differ in their last field
// (reserved). By adding the |current_header_size_| and the
// |current_header_offset_|, you can determine the offset in the file just
// after the header.
struct mach_header_64 *current_header_;
unsigned long current_header_size_;
off_t current_header_offset_;
private:
MachoWalker(const MachoWalker &);
MachoWalker &operator=(const MachoWalker &);
};
} // namespace MacFileUtilities
#endif // COMMON_MAC_MACHO_WALKER_H__
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