Method and device for hooking function

Abstract

The invention relates to a method and device for hooking a function. The method comprises the following steps: acquiring a to-be-hooked original function; judging a returned value type of the original function; configuring a corresponding substitution function containing a pre-callback function and a post-callback function according to the returned value type of the original function; and substituting the original function with the substitution function to realize the hooking of the original function. By use of the method and device disclosed by the invention, the returned value type of the original function is judged after the original function is acquired, the corresponding substitution function containing the pre-callback function and the post-callback function is configured according to the returned value type, and the original function is substituted by the substitution function to realize the hooking of the original function. One kind of returned value types are corresponding to the same substitution function by use of the returned value type to configure the substitution function, the corresponding between each function and one substitution function is unnecessary, the code quantity is reduced, and the space is saved. Whether the original function parameter and the returned need to be modified is judged through the pre-callback function and the post-callback function, and the control to the original function is realized.

Description

technical field [0001] The invention relates to the field of data processing, in particular to a method and device for hooking functions. Background technique [0002] The hook technology used in iOS development is implemented through the system function class_replaceMethod. For example, function A has three parameters p1, p2, and p3. The return type is r. If you want to implement a hook for this function, you must write a function parameter with A For the same function as the return value, the traditional object-C syntax is used to describe the function A: -(r)FUN_A:(id)p1 p2:(id)p2 p3:(id)p3; the replacement function should be written as follows, The function name can be arbitrary: -(r)FAKE_FUN_A:(id)p1 p2:(id)p2p3:(id)p3. [0003] However, when the above method needs to hook many functions, it is necessary to write a corresponding replacement function for each function. Each function has different return values ​​and different parameters, which cannot be processed togeth...

AI Technical Summary

Problems solved by technology

[0004] Based on this, it is necessary to provide a method of hooking functions, which can reduce the amount of code and save space, in order to solve the problem of code increase when many functions are traditionally hooked.

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