Skip to main content

​
LM_HookCode

Places a hook/detour onto the address from, redirecting it to the address to. Optionally generates a trampoline to call the original function.

​
Signature

lm_size_t LM_HookCode(
    lm_address_t  from,
    lm_address_t  to,
    lm_address_t *trampoline_out
);

​
Parameters

​
from
lm_address_t
required
The address where the hook will be placed.
​
to
lm_address_t
required
The address where the hook will jump to.
​
trampoline_out
lm_address_t*
Optional pointer to an lm_address_t variable that will receive a trampoline/gateway to call the original function. Pass LM_NULLPTR if you don’t need a trampoline.

​
Returns

The amount of bytes occupied by the hook (aligned to the nearest instruction). Returns 0 on failure.

​
Example

#include <libmem/libmem.h>

void hk_take_damage(int amount)
{
  printf("hooked take_damage! no damage will be taken\n");
  return;
}

int main()
{
	lm_module_t game_mod;
	lm_address_t fn_take_damage;

	LM_FindModule("game.dll", &game_mod);
	printf("[*] Base address of 'game.dll': %p\n", game_mod.base);

	fn_take_damage = LM_FindSymbolAddress(&game_mod, "take_damage");
	printf("[*] Found 'take_damage' function: %p\n", fn_take_damage);

	LM_HookCode(fn_take_damage, hk_take_damage, LM_NULLPTR);
	printf("[*] 'take_damage' hooked, player will no longer receive damage\n");

	return 0;
}

​
LM_HookCodeEx

Places a hook/detour onto the address from in a remote process, redirecting it to the address to. Optionally generates a trampoline to call the original function in the remote process.

​
Signature

lm_size_t LM_HookCodeEx(
    const lm_process_t *process,
    lm_address_t        from,
    lm_address_t        to,
    lm_address_t       *trampoline_out
);

​
Parameters

​
process
const lm_process_t*
required
The remote process to place the hook in.
​
from
lm_address_t
required
The address where the hook will be placed in the remote process.
​
to
lm_address_t
required
The address where the hook will jump to in the remote process.
​
trampoline_out
lm_address_t*
Optional pointer to an lm_address_t variable that will receive a trampoline/gateway to call the original function in the remote process. Pass LM_NULLPTR if you don’t need a trampoline.

​
Returns

The amount of bytes occupied by the hook (aligned to the nearest instruction) in the remote process. Returns 0 on failure.

Build docs developers (and LLMs) love

Get started for freeTalk to us