tinyhook

A tiny macOS inline hook framework

Now support both ARM64 and x86_64!

functions

read and write memory

int read_mem(void *destnation, const void *source, size_t len);
int write_mem(void *destnation, const void *source, size_t len);

insert a jump at an address

tiny_insert() uses bl or b (depends on link flag) on ARM64, and jmp or call on x86_64

tiny_isnert_far() uses adrp + blr/br on ARM64, and jmp or call on x86_64

int tiny_insert(void *address, void *destnation, bool link);
int tiny_insert_far(void *address, void *destnation, bool link);

inline hook

origin can be NULL

int tiny_hook(void *function, void *destnation, void **origin);

examples

#include <stdio.h>
#include <mach-o/dyld.h>

#include "tinyhook.h"

uint32_t (*orig_dyld_image_count)(void);
uint32_t my_dyld_image_count(void) {
	uint32_t image_count = orig_dyld_image_count();
	printf("hooked _dyld_image_count: %d!\n", image_count);
	return 5;
}

int main() {
	int image_count = _dyld_image_count();
	for (int i = 0; i < image_count; i++) {
		printf("image[%d]: %s\n", i, _dyld_get_image_name(i));
	}

	tiny_hook(_dyld_image_count, my_dyld_image_count, (void **)&orig_dyld_image_count);

	int image_count = _dyld_image_count();
	for (int i = 0; i < image_count; i++) {
		printf("image[%d]: %s\n", i, _dyld_get_image_name(i));
	}
	return 0;
}

references

Thanks to these projects for their inspiring idea and code!

• https://github.com/rodionovd/rd_route
• https://github.com/GiveMeZeny/fde64