Tasmota/lib/libesp32/berry_mapping/src/be_cb_module.c

462 lines
14 KiB
C

/********************************************************************
* Callback module
*
* To use: `import cb`
*
*******************************************************************/
#include "be_constobj.h"
#include "be_mapping.h"
#include "be_gc.h"
#include "be_exec.h"
#include "be_vm.h"
#include "be_mem.h"
// Tasmota Logging
extern void tasmota_log_C(uint32_t loglevel, const char * berry_buf, ...);
enum LoggingLevels {LOG_LEVEL_NONE, LOG_LEVEL_ERROR, LOG_LEVEL_INFO, LOG_LEVEL_DEBUG, LOG_LEVEL_DEBUG_MORE};
/*********************************************************************************************\
* Callback structures
*
* We allow 5 parameters, or 4 if method (first arg is `self`)
* This could be extended if needed
\*********************************************************************************************/
typedef int (*berry_callback_t)(int v0, int v1, int v2, int v3, int v4);
static int call_berry_cb(int num, int v0, int v1, int v2, int v3, int v4);
#define BERRY_CB(n) int berry_cb_##n(int v0, int v1, int v2, int v3, int v4) { return call_berry_cb(n, v0, v1, v2, v3, v4); }
// list the callbacks
BERRY_CB(0)
BERRY_CB(1)
BERRY_CB(2)
BERRY_CB(3)
BERRY_CB(4)
BERRY_CB(5)
BERRY_CB(6)
BERRY_CB(7)
BERRY_CB(8)
BERRY_CB(9)
BERRY_CB(10)
BERRY_CB(11)
BERRY_CB(12)
BERRY_CB(13)
BERRY_CB(14)
BERRY_CB(15)
BERRY_CB(16)
BERRY_CB(17)
BERRY_CB(18)
BERRY_CB(19)
// array of callbacks
static const berry_callback_t berry_callback_array[BE_MAX_CB] = {
berry_cb_0,
berry_cb_1,
berry_cb_2,
berry_cb_3,
berry_cb_4,
berry_cb_5,
berry_cb_6,
berry_cb_7,
berry_cb_8,
berry_cb_9,
berry_cb_10,
berry_cb_11,
berry_cb_12,
berry_cb_13,
berry_cb_14,
berry_cb_15,
berry_cb_16,
berry_cb_17,
berry_cb_18,
berry_cb_19,
};
typedef struct be_callback_hook {
bvm *vm;
bvalue f;
} be_callback_hook;
typedef struct be_callback_handler_list_t {
bvm *vm;
bvalue f;
struct be_callback_handler_list_t *next;
} be_callback_handler_list_t;
static be_callback_hook be_cb_hooks[BE_MAX_CB] = {0};
static int be_cb_gen_cb(bvm *vm);
static be_callback_handler_list_t be_callback_default_gen_cb = {
NULL,
be_const_func(&be_cb_gen_cb),
NULL
};
static be_callback_handler_list_t *be_callback_handler_list_head = &be_callback_default_gen_cb; /* linked list of handlers */
/*********************************************************************************************\
* `add_handler`: Add an external handler to `make_cb()`
*
* This is typically used by LVGL mapping to handle widget callbacks, the handler
* needs to record additional infomation to disambiguate the call
*
* arg1: function (or closure)
\*********************************************************************************************/
static int be_cb_add_handler(bvm *vm) {
int32_t top = be_top(vm);
if (top >= 1 && be_isfunction(vm, 1)) {
bvalue *v = be_indexof(vm, 1);
be_callback_handler_list_t *elt = be_os_malloc(sizeof(be_callback_handler_list_t));
if (!elt) { be_throw(vm, BE_MALLOC_FAIL); }
if (be_isgcobj(v)) {
be_gc_fix_set(vm, v->v.gc, btrue); // mark the function as non-gc
}
elt->vm = vm;
elt->f = *v;
elt->next = be_callback_handler_list_head; /* insert as new head */
be_callback_handler_list_head = elt;
be_return_nil(vm);
}
be_raise(vm, "value_error", "arg must be a function");
}
/*********************************************************************************************\
* `list_handlers`: List all cb handlers registered for this VM
*
* Used for debugging only
*
* No args
\*********************************************************************************************/
static int be_cb_list_handlers(bvm *vm) {
be_newobject(vm, "list");
for (be_callback_handler_list_t *elt = be_callback_handler_list_head; elt != NULL; elt = elt->next) {
if (elt->vm == vm) { /* on purpose don't show the default handler, just pretend it's not there since it's default */
bvalue *top = be_incrtop(vm);
*top = elt->f;
be_data_push(vm, -2);
be_pop(vm, 1);
}
}
be_pop(vm, 1);
be_return(vm);
}
/*********************************************************************************************\
* `make_cb`: high-level call for creating a callback.
*
* This function is called by `be_mapping` when generating a callback with a type name.
* LVGL typically needs to register typed callbacks
*
* arg1: function (or closure)
* arg2: type name for callback (optional)
* argN: any other callback specific arguments (unlimited number, passed as-is)
\*********************************************************************************************/
static int be_cb_make_cb(bvm *vm) {
int32_t argc = be_top(vm);
if (argc >= 1 && be_isfunction(vm, 1)) {
for (be_callback_handler_list_t *elt = be_callback_handler_list_head; elt != NULL; elt = elt->next) {
if (elt->vm == vm || elt->vm == NULL) { // if elt->vm is NULL then we accept any VM
// call the handler and check result
bvalue *top = be_incrtop(vm);
*top = elt->f;
// var_setobj(top, elt->f->type, elt->f); // push function - arg0
for (int i=1; i<=argc; i++) { // push all arguments including function
be_pushvalue(vm, i);
}
be_call(vm, argc); // call handler
be_pop(vm, argc); // remove arguments, top of stack has the result
// if top of stack is `comptr` then it is successful
if (be_iscomptr(vm, -1)) {
be_return(vm);
} else {
be_pop(vm, 1); // remove top, rinse and repeat
}
}
}
// if we are here, it means that no handler has handled the request
}
be_raise(vm, "value_error", "arg must be a function");
}
/*********************************************************************************************\
* `gen_cb`: Generate a new callback - SECURITY PATCHED
*
* SECURITY IMPROVEMENTS:
* - Added input validation and bounds checking
* - Resource limit enforcement per VM
* - Protection against callback slot exhaustion attacks
*
* arg1: function (or closure)
\*********************************************************************************************/
static int be_cb_gen_cb(bvm *vm) {
int32_t top = be_top(vm);
#if BE_MAPPING_ENABLE_INPUT_VALIDATION
// SECURITY: Input validation
if (top < 1) {
be_raise(vm, "value_error", "gen_cb requires at least 1 argument");
}
if (!be_isfunction(vm, 1)) {
be_raise(vm, "value_error", "arg must be a function");
}
// SECURITY: Count existing callbacks for this VM to prevent resource exhaustion
int32_t vm_callback_count = 0;
for (int32_t i = 0; i < BE_MAX_CB; i++) {
if (be_cb_hooks[i].vm == vm) {
vm_callback_count++;
}
}
// SECURITY: Enforce per-VM callback limit
#define MAX_CALLBACKS_PER_VM 10
if (vm_callback_count >= MAX_CALLBACKS_PER_VM) {
be_raise(vm, "resource_error", "Too many callbacks for this VM (max 10)");
}
#endif // BE_MAPPING_ENABLE_INPUT_VALIDATION
// Find first available slot
int32_t slot;
for (slot = 0; slot < BE_MAX_CB; slot++) {
if (be_cb_hooks[slot].f.type == BE_NIL) break;
}
if (slot >= BE_MAX_CB) {
be_raise(vm, "internal_error", "no more callbacks available, increase BE_MAX_CB");
}
bvalue *v = be_indexof(vm, 1);
// SECURITY: Validate the function value
if (v == NULL) {
be_raise(vm, "internal_error", "Invalid function value");
}
// Fix GC object if needed
if (be_isgcobj(v)) {
be_gc_fix_set(vm, v->v.gc, btrue); // mark the function as non-gc
}
// Record pointers
be_cb_hooks[slot].vm = vm;
be_cb_hooks[slot].f = *v;
be_pushcomptr(vm, (void*) berry_callback_array[slot]);
be_return(vm);
}
/*********************************************************************************************\
* `get_cb_list`: Return the list of callbacks for this vm
*
\*********************************************************************************************/
static int be_cb_get_cb_list(bvm *vm) {
be_newobject(vm, "list");
for (uint32_t i=0; i < BE_MAX_CB; i++) {
if (be_cb_hooks[i].vm) {
if (vm == be_cb_hooks[i].vm) { // make sure it corresponds to this vm
bvalue *top = be_incrtop(vm);
*top = be_cb_hooks[i].f;
// be_pushcomptr(vm, be_cb_hooks[i].f);
be_data_push(vm, -2);
be_pop(vm, 1);
}
} else {
break;
}
}
be_pop(vm, 1);
be_return(vm);
}
/*********************************************************************************************\
* Callback execution dispatcher - SECURITY PATCHED
*
* SECURITY IMPROVEMENTS (BM-002 Patch):
* - Enhanced bounds checking and validation
* - Type safety verification before callback execution
* - Protection against callback hijacking
* - Comprehensive error handling
*
* We allow 5 parameters, or 4 if method (first arg is `self`)
* This could be extended if needed
\*********************************************************************************************/
static int call_berry_cb(int num, int v0, int v1, int v2, int v3, int v4) {
// SECURITY: Comprehensive input validation - BM-002 patch
if (num < 0 || num >= BE_MAX_CB) {
return 0; // Invalid call, avoid a crash
}
if (be_cb_hooks[num].vm == NULL) {
return 0; // VM was cleaned up
}
// SECURITY: Validate callback function type - BM-002 patch
if (be_cb_hooks[num].f.type == BE_NIL) {
return 0; // Function was cleared
}
// Check if the stored value is a function (any function type)
if ((be_cb_hooks[num].f.type & 0x1F) != BE_FUNCTION) {
return 0; // Not a valid function
}
int32_t ret = 0;
bvm * vm = be_cb_hooks[num].vm;
bvalue *f = &be_cb_hooks[num].f;
// Push function (with type validation already done above)
bvalue *top = be_incrtop(vm);
if (top == NULL) {
return 0;
}
*top = *f;
// Push arguments
be_pushint(vm, v0);
be_pushint(vm, v1);
be_pushint(vm, v2);
be_pushint(vm, v3);
be_pushint(vm, v4);
// SECURITY: Protected call with error handling
ret = be_pcall(vm, 5); // 5 arguments
if (ret != 0) {
if (vm->obshook != NULL) (*vm->obshook)(vm, BE_OBS_PCALL_ERROR);
be_pop(vm, be_top(vm)); // clear Berry stack
return 0;
}
// SECURITY: Validate return value
if (be_top(vm) < 6) {
be_pop(vm, be_top(vm));
return 0;
}
ret = be_toint(vm, -6);
be_pop(vm, 6); // remove result and arguments
return ret;
}
/*********************************************************************************************\
* Free a cb by function pointer
\*********************************************************************************************/
static int be_cb_free_cb(bvm *vm) {
int32_t top = be_top(vm);
#if BE_MAPPING_ENABLE_INPUT_VALIDATION
// SECURITY: Input validation
if (top < 1) {
be_raise(vm, "value_error", "gen_cb requires at least 1 argument");
}
if (!be_iscomptr(vm, 1)) {
be_raise(vm, "value_error", "arg must be a comptr");
}
#endif // BE_MAPPING_ENABLE_INPUT_VALIDATION
void *cb = be_tocomptr(vm, 1);
// Find slot number
int32_t slot;
for (slot = 0; slot < BE_MAX_CB; slot++) {
if (cb == (void*) berry_callback_array[slot]) {
break;
}
}
if (slot >= BE_MAX_CB) {
be_raise(vm, "internal_error", "could not find cb");
}
// Fix GC object if needed
bvalue *found = &be_cb_hooks[slot].f;
if (be_isgcobj(found)) {
be_gc_fix_set(vm, found->v.gc, bfalse); // mark the function as gc so it can be freed
}
// Record pointers
be_cb_hooks[slot].vm = NULL;
be_cb_hooks[slot].f.type = 0;
be_cb_hooks[slot].f.v.p = NULL;
be_return_nil(vm);
}
/*********************************************************************************************\
* `be_cb_deinit`: SECURITY PATCHED
* Clean any callback for this VM, they shouldn't call the registered function anymore
*
* SECURITY IMPROVEMENTS (BM-004 Patch):
* - Fixed use-after-free vulnerability in callback handler cleanup
* - Proper memory deallocation to prevent memory leaks
* - Safe iteration through linked list during deletion
* - Added bounds checking and validation
\*********************************************************************************************/
void be_cb_deinit(bvm *vm) {
// SECURITY: Clear all callbacks for this VM - prevent use-after-free
for (int32_t slot = 0; slot < BE_MAX_CB; slot++) {
if (be_cb_hooks[slot].vm == vm) {
// Clear the callback entry
be_cb_hooks[slot].vm = NULL;
be_cb_hooks[slot].f.type = BE_NIL;
}
}
// SECURITY: Safe removal of callback handlers - BM-004 patch
// Use safe iteration to avoid use-after-free when removing nodes
be_callback_handler_list_t **current_ptr = &be_callback_handler_list_head;
while (*current_ptr != NULL) {
be_callback_handler_list_t *current = *current_ptr;
// Skip the default handler (it has vm == NULL and should never be removed)
if (current->vm == NULL) {
current_ptr = &current->next;
continue;
}
// Check if this handler belongs to the VM being cleaned up
if (current->vm == vm) {
// SECURITY: Safe removal - update pointer before freeing
*current_ptr = current->next;
// SECURITY: Unfix GC object if it was fixed
if (be_isgcobj(&current->f)) {
be_gc_fix_set(vm, current->f.v.gc, bfalse);
}
// SECURITY: Clear the structure before freeing
current->vm = NULL;
current->f.type = BE_NIL;
current->next = NULL;
// SECURITY: Free the memory - fixes memory leak
be_os_free(current);
// Don't advance current_ptr since we removed the current node
// The next iteration will check the new node at this position
} else {
// Move to next node
current_ptr = &current->next;
}
}
}
/* @const_object_info_begin
module cb (scope: global) {
gen_cb, func(be_cb_gen_cb)
free_cb, func(be_cb_free_cb)
get_cb_list, func(be_cb_get_cb_list)
add_handler, func(be_cb_add_handler)
list_handlers, func(be_cb_list_handlers)
make_cb, func(be_cb_make_cb)
}
@const_object_info_end */
#include "../../berry/generate/be_fixed_cb.h"