DYLD_INTERPOSE

• DYLD_INTERPOSE

  • 是什么：宏定义的函数
  • 所属头文件：dyld-interposing.h
  • 定义

    #define DYLD_INTERPOSE(_replacement,_replacee) \
      __attribute__((used)) static struct{ const void* replacement; const void* replacee; } _interpose_##_replacee \
                __attribute__ ((section ("__DATA,__interpose"))) = { (const void*)(unsigned long)&_replacement, (const void*)(unsigned long)&_replacee };
    

  • 用法举例

    static int my_open(const char* path, int flags, mode_t mode){
      int value;
      // do stuff before open (including changing the arguments)
      value = open(path, flags, mode);
      // do stuff after open (including changing the return value(s))
      return value;
    }
    
    DYLD_INTERPOSE(my_open, open)
    

涉及到的内容

FDInterposing.cpp

FDInterposing.cpp

DYLD_INTERPOSE(__open_extended$__interposed__, __open_extended);

fishhook

facebook/fishhook

fishhook is a very simple library that enables dynamically rebinding symbols in Mach-O binaries running on iOS in the simulator and on device. This provides functionality that is similar to using DYLD_INTERPOSE on OS X. At Facebook, we've found it useful as a way to hook calls in libSystem for debugging/tracing purposes (for example, auditing for double-close issues with file descriptors).