diff options
Diffstat (limited to 'CRT/kcrt.c')
| -rw-r--r-- | CRT/kcrt.c | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/CRT/kcrt.c b/CRT/kcrt.c new file mode 100644 index 0000000..11f20d3 --- /dev/null +++ b/CRT/kcrt.c @@ -0,0 +1,313 @@ +/* + * Shameless copy pasta from: https://github.com/sidyhe/dxx + * and: https://github.com/liupengs/Mini-CRT + * and some minor modifications. + */ + +#include <ntddk.h> + +#include "except.h" + +#define KCRT_POOL_DEFAULT_TAG 0xDEADBEEF + +extern void (*__CTOR_LIST__)(); +extern void (*__DTOR_LIST__)(); +extern NTSTATUS __cdecl DriverEntry(struct _DRIVER_OBJECT * DriverObject, PUNICODE_STRING RegistryPath); +extern void __cdecl DriverUnload(struct _DRIVER_OBJECT * DriverObject); +extern int __cdecl ntdll_zw_functions(void); + +DRIVER_INITIALIZE __cdecl _CRT_DriverEntry; +DRIVER_UNLOAD __cdecl _CRT_DriverUnload; + +typedef void (*__cdecl init_and_deinit_fn)(void); +typedef void (*__cdecl atexit_func_t)(void); + +typedef struct _func_node +{ + atexit_func_t func; + struct _func_node * next; +} func_node; + +typedef struct _MALLOC_HEADER +{ + ULONG32 Tags; + ULONG32 _Resv0; + ULONG_PTR Size; +} MALLOC_HEADER, *PMALLOC_HEADER; +C_ASSERT(sizeof(MALLOC_HEADER) % sizeof(void *) == 0); + +static func_node * atexit_list = NULL; + +// dynamic memory mgmt + +PMALLOC_HEADER GET_MALLOC_HEADER(PVOID ptr) +{ + return (MALLOC_HEADER *)((PUCHAR)ptr - sizeof(MALLOC_HEADER)); +} + +PVOID GET_MALLOC_ADDRESS(PMALLOC_HEADER header) +{ + return (PVOID)((PUCHAR)header + sizeof(MALLOC_HEADER)); +} + +ULONG_PTR GET_MALLOC_SIZE(PVOID ptr) +{ + PMALLOC_HEADER header = GET_MALLOC_HEADER(ptr); + + if (header->Tags != KCRT_POOL_DEFAULT_TAG) + KeBugCheckEx(BAD_POOL_HEADER, 0, 0, 0, 0); + + return header->Size; +} + +// c runtime + +static int register_atexit(atexit_func_t func) +{ + func_node * node; + if (!func) + return -1; + + node = (func_node *)malloc(sizeof(func_node)); + + if (node == 0) + return -1; + + node->func = func; + node->next = atexit_list; + atexit_list = node; + return 0; +} + +int __cdecl atexit(atexit_func_t func) +{ + return register_atexit(func); +} + +void __cdecl free(void * ptr) +{ + if (ptr) + { + MALLOC_HEADER * mhdr = GET_MALLOC_HEADER(ptr); + + if (mhdr->Tags != KCRT_POOL_DEFAULT_TAG) + KeBugCheckEx(BAD_POOL_HEADER, 0, 0, 0, 0); + + ExFreePool(mhdr); + } +} + +void * __cdecl malloc(size_t size) +{ + PMALLOC_HEADER mhdr = NULL; + const size_t new_size = size + sizeof(MALLOC_HEADER); + + mhdr = (PMALLOC_HEADER)ExAllocatePoolWithTag(new_size > PAGE_SIZE ? PagedPool : NonPagedPool, new_size, KCRT_POOL_DEFAULT_TAG); + if (mhdr) + { + RtlZeroMemory(mhdr, new_size); + + mhdr->Tags = KCRT_POOL_DEFAULT_TAG; + mhdr->Size = size; + return GET_MALLOC_ADDRESS(mhdr); + } + + return NULL; +} + +void * __cdecl calloc(size_t nmemb, size_t size) +{ + return malloc(nmemb * size); +} + +void * __cdecl realloc(void * ptr, size_t new_size) +{ + if (!ptr) + { + return malloc(new_size); + } + else if (new_size == 0) + { + free(ptr); + return NULL; + } + else + { + size_t old_size = GET_MALLOC_SIZE(ptr); + + if (new_size <= old_size) + { + return ptr; + } + else + { + void * new_ptr = malloc(new_size); + + if (new_ptr) + { + memcpy(new_ptr, ptr, old_size); + free(ptr); + return new_ptr; + } + } + } + + return NULL; +} + +void __cdecl __cxa_pure_virtual(void) +{ + // definitly not perfect, but we get at least a notification + while (1) + { + DbgPrint("Pure virtual function call..\n"); + LARGE_INTEGER li = {.QuadPart = -10000000}; + KeDelayExecutionThread(KernelMode, TRUE, &li); + } +} + +// stolen from musl: https://elixir.bootlin.com/musl/v1.1.9/source/src/math/ceilf.c +#define FORCE_EVAL(x) \ + do \ + { \ + if (sizeof(x) == sizeof(float)) \ + { \ + volatile float __x __attribute__((unused)); \ + __x = (x); \ + } \ + else if (sizeof(x) == sizeof(double)) \ + { \ + volatile double __x __attribute__((unused)); \ + __x = (x); \ + } \ + else \ + { \ + volatile long double __x __attribute__((unused)); \ + __x = (x); \ + } \ + } while (0) + +float __cdecl ceilf(float x) +{ + union + { + float f; + UINT32 i; + } u = {x}; + int e = (int)(u.i >> 23 & 0xff) - 0x7f; + UINT32 m; + + if (e >= 23) + return x; + if (e >= 0) + { + m = 0x007fffff >> e; + if ((u.i & m) == 0) + return x; + FORCE_EVAL(x + 0x1p120f); + if (u.i >> 31 == 0) + u.i += m; + u.i &= ~m; + } + else + { + FORCE_EVAL(x + 0x1p120f); + if (u.i >> 31) + u.f = -0.0; + else if (u.i << 1) + u.f = 1.0; + } + return u.f; +} + +// functions called in DRIVER_INITIALIZE and DRIVER_UNLOAD + +static void __cdecl __ctors(void) +{ + unsigned long long int const * const * const l = (unsigned long long int const * const * const) & __CTOR_LIST__; + unsigned long long int i = (unsigned long long int)*l; + init_and_deinit_fn const * p; + + if (i == (unsigned long long int)-1) + { + for (i = 1; l[i] != NULL; i++) + ; + i--; + } + + p = (init_and_deinit_fn *)&l[i]; + + while (i--) + { + (**p--)(); + } +} + +static void __cdecl __dtors(void) +{ + func_node * p = atexit_list; + for (; p != NULL; p = p->next) + { + p->func(); + free(p); + } + atexit_list = NULL; +} + +void __cdecl KCRT_OnDriverEntry(void) +{ + __ctors(); +} + +void __cdecl KCRT_OnDriverUnload(void) +{ + __dtors(); +} + +void __cdecl _CRT_DriverUnload(struct _DRIVER_OBJECT * DriverObject) +{ + DriverUnload(DriverObject); + + KCRT_OnDriverUnload(); +} + +NTSTATUS __cdecl _CRT_DriverEntry(struct _DRIVER_OBJECT * DriverObject, PUNICODE_STRING RegistryPath) +{ + NTSTATUS retval; + + KCRT_OnDriverEntry(); + + int zw_retval = ntdll_zw_functions(); + if (zw_retval != 0) + { + return STATUS_NOT_IMPLEMENTED; + } + + retval = DriverEntry(DriverObject, RegistryPath); + + /* support for service stopping and CRT de-init */ + DriverObject->DriverUnload = _CRT_DriverUnload; + + return retval; +} + +void __cdecl _enable(void) +{ + __asm__ __volatile__("sti"); +} + +void __cdecl _disable(void) +{ + __asm__ __volatile__("cli"); +} + +void * __cdecl _AddressOfReturnAddress(void) +{ + return __builtin_extract_return_addr(__builtin_return_address(0)); +} + +char __cdecl _putchar(char c) +{ + DbgPrint("%c", c); + return c; +} |