mach-detours/tests/test_dylib_function.cpp

// Copyright (c) Lysann Tranvouez.  All rights reserved.

#include <catch2/catch_test_macros.hpp>

#include <mach_detours.h>

#include "lib_function.h"
int (*realLibFunction)() = libFunction;

static int libFunctionDetourCounter = 0;
int libFunctionDetour()
{
    libFunctionDetourCounter++;
    return 94;
}

TEST_CASE( "Overriding custom function in dylib", "[dylib]" )
{
    libFunctionCounter = 0;
    libFunctionDetourCounter = 0;

    SECTION( "attaching installs a detour" )
    {
        REQUIRE( realLibFunction == libFunction );
        REQUIRE( libFunction() == 42 );
        REQUIRE( libFunctionCounter == 1 );
        REQUIRE( libFunctionDetourCounter == 0 );

        REQUIRE( detour_transaction_begin() == err_none );

        SECTION( "attach + transaction_commit" )
        {
            REQUIRE( detour_attach(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == err_none );
            CHECK( detour_transaction_commit() == err_none );
        }
        SECTION( "attach_and_commit" )
        {
            CHECK( detour_attach_and_commit(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == err_none );
        }

        CHECK( realLibFunction != libFunction );
        CHECK( libFunctionCounter == 1 );
        CHECK( libFunctionDetourCounter == 0 );
        CHECK( libFunction() == 94 );
        CHECK( libFunctionCounter == 1 );
        CHECK( libFunctionDetourCounter == 1 );

        // clean up
        REQUIRE( detour_transaction_begin() == err_none );
        CHECK( detour_detach_and_commit(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == err_none );
    }

    SECTION( "detaching in separate transaction removes detour" )
    {
        REQUIRE( detour_transaction_begin() == err_none );
        REQUIRE( detour_attach_and_commit(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == err_none );
        REQUIRE( realLibFunction != libFunction );

        REQUIRE( detour_transaction_begin() == err_none );

        SECTION( "detach + transaction_commit" )
        {
            REQUIRE( detour_detach(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == err_none );
            CHECK( detour_transaction_commit() == err_none );
        }
        SECTION( "detach_and_commit" )
        {
            CHECK( detour_detach_and_commit(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == err_none );
        }

        CHECK( realLibFunction == libFunction );
        CHECK( libFunctionCounter == 0 );
        CHECK( libFunctionDetourCounter == 0 );
        CHECK( libFunction() == 42 );
        CHECK( libFunctionCounter == 1 );
        CHECK( libFunctionDetourCounter == 0 );
    }

    SECTION( "aborting transaction means no detour" )
    {
        REQUIRE( detour_transaction_begin() == err_none );
        REQUIRE( detour_attach(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == err_none );
        CHECK( detour_transaction_abort() == err_none );

        CHECK( realLibFunction == libFunction );
        CHECK( libFunctionCounter == 0 );
        CHECK( libFunctionDetourCounter == 0 );
        CHECK( libFunction() == 42 );
        CHECK( libFunctionCounter == 1 );
        CHECK( libFunctionDetourCounter == 0 );
    }

    SECTION( "an error in a transaction means no detour" )
    {
        REQUIRE( detour_transaction_begin() == err_none );
        REQUIRE( detour_attach(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == err_none );
        // cannot detach because trampoline is not yet in place
        CHECK( detour_detach(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == KERN_FAILURE );
        CHECK( detour_transaction_commit() == KERN_FAILURE );

        CHECK( realLibFunction == libFunction );
        CHECK( libFunctionCounter == 0 );
        CHECK( libFunctionDetourCounter == 0 );
        CHECK( libFunction() == 42 );
        CHECK( libFunctionCounter == 1 );
        CHECK( libFunctionDetourCounter == 0 );
    }
}