userdata

TODO.md

@@ -2,21 +2,8 @@
 
 - make `computer` component use callbacks
 - finish tmpfs (rework the whole thing)
-- userdata support
 - get rid of component signals (useless)
 
-## Userdata system
-
-The idea is that the computer stores userdata as structs which have a pointer (the state) and a bound-component address.
-When a component is removed, all of its associated userdata is instantly dropped.
-For serialization, the userdata pushes a string storing the encoded byte buffer.
-For deserialization, the userdata pops a string and decodes it.
-
-To get component methods, requests are sent to get method info by index, and a NULL name means method is not allowed for that
-particular userdata. Methods can obviously be invoked just like component data.
-Serialization pushes the string on the stack, deserialization gets the buffer as ptr + len and sets the state pointer.
-They are handled by components, thus if it is not mounted at deserialization time, the deserialization fails.
-
 # To re-evaluate
 
 - Exposing the internal non-resizing hashmap implementation.

src/luaarch.c

@@ -600,6 +600,84 @@ static int luaArch_unicode_wtrunc(lua_State *L) {
 	return 1;
 }
 
+static int luaArch_userdata_free(lua_State *L) {
+	luaArch *arch = luaArch_from(L);
+	size_t user = (size_t)lua_touserdata(L, 1);
+	nn_freeUserdata(arch->computer, user);
+	return 0;
+}
+
+static int luaArch_userdata_methods(lua_State *L) {
+	luaArch *arch = luaArch_from(L);
+	size_t user = (size_t)lua_touserdata(L, 1);
+	if(!nn_isUserdataValid(arch->computer, user)) {
+		lua_pushnil(L);
+		lua_pushstring(L, "no such userdata");
+		return 2;
+	}
+	lua_createtable(L, 0, 0);
+	size_t idx = 0;
+	while(true) {
+		nn_Method m;
+		if(nn_getUserdataMethod(arch->computer, user, idx, &m)) break;
+		idx++;
+		if(m.name == NULL) continue;
+		lua_pushstring(L, m.name);
+		lua_createtable(L, 0, 4);
+
+		// the method data
+		{
+			lua_pushstring(L, "doc");
+			if(m.doc == NULL) lua_pushnil(L); else lua_pushstring(L, m.doc);
+			lua_settable(L, -3);
+
+			lua_pushstring(L, "direct");
+			lua_pushboolean(L, (m.flags & NN_DIRECT) != 0);
+			lua_settable(L, -3);
+			
+			lua_pushstring(L, "getter");
+			lua_pushboolean(L, (m.flags & NN_GETTER) != 0);
+			lua_settable(L, -3);
+			
+			lua_pushstring(L, "setter");
+			lua_pushboolean(L, (m.flags & NN_SETTER) != 0);
+			lua_settable(L, -3);
+		}
+
+		lua_settable(L, -3);
+	}
+	return 1;
+}
+
+static int luaArch_userdata_invoke(lua_State *L) {
+	luaArch *arch = luaArch_from(L);
+	size_t user = (size_t)lua_touserdata(L, 1);
+	if(!nn_isUserdataValid(arch->computer, user)) {
+		lua_pushnil(L);
+		lua_pushstring(L, "no such userdata");
+		return 2;
+	}
+	const char *method = luaL_checkstring(L, 2);
+	size_t argc = lua_gettop(L);
+	
+	nn_clearstack(arch->computer);
+	for(size_t i = 3; i <= argc; i++) {
+		luaArch_luaToNN(arch, L, i);
+	}
+	nn_Exit err = nn_invokeUserdata(arch->computer, user, method);
+	if(err != NN_OK) {
+		lua_pushnil(L);
+		lua_pushstring(L, nn_getError(arch->computer));
+		return 2;
+	}
+	size_t retc = nn_getstacksize(arch->computer);
+	for(size_t i = 0; i < retc; i++) {
+		luaArch_nnToLua(arch, L, i);
+	}
+	nn_clearstack(arch->computer);
+	return retc;
+}
+
 static void luaArch_loadEnv(lua_State *L) {
 	lua_createtable(L, 0, 10);
 	int computer = lua_gettop(L);
@@ -644,6 +722,7 @@ static void luaArch_loadEnv(lua_State *L) {
 	lua_pushcfunction(L, luaArch_computer_getDeviceInfo);
 	lua_setfield(L, computer, "getDeviceInfo");
 	lua_setglobal(L, "computer");
+
 	lua_createtable(L, 0, 10);
 	int component = lua_gettop(L);
 	lua_pushcfunction(L, luaArch_component_list);
@@ -663,6 +742,7 @@ static void luaArch_loadEnv(lua_State *L) {
 	lua_pushcfunction(L, luaArch_component_fields);
 	lua_setfield(L, component, "fields");
 	lua_setglobal(L, "component");
+
 	lua_createtable(L, 0, 10);
 	int unicode = lua_gettop(L);
 	lua_pushcfunction(L, luaArch_unicode_char);
@@ -676,6 +756,16 @@ static void luaArch_loadEnv(lua_State *L) {
 	lua_pushcfunction(L, luaArch_unicode_wtrunc);
 	lua_setfield(L, unicode, "wtrunc");
 	lua_setglobal(L, "unicode");
+
+	lua_createtable(L, 0, 10);
+	int userdata = lua_gettop(L);
+	lua_pushcfunction(L, luaArch_userdata_free);
+	lua_setfield(L, userdata, "free");
+	lua_pushcfunction(L, luaArch_userdata_methods);
+	lua_setfield(L, userdata, "methods");
+	lua_pushcfunction(L, luaArch_userdata_invoke);
+	lua_setfield(L, userdata, "invoke");
+	lua_setglobal(L, "userdata");
 }
 
 static nn_Exit luaArch_handler(nn_ArchitectureRequest *req) {

src/machine.lua

@@ -70,6 +70,44 @@ end
 
 local syncedMethodStats
 
+local function sandboxValue(val)
+	if type(val) == "table" then
+		local nt = {}
+		for k, v in pairs(val) do
+			local sk, sv = sandboxValue(k), sandboxValue(v)
+			if sk ~= nil then nt[sk] = sv end
+		end
+		return nt
+	end
+	if type(val) == "userdata" then
+		-- Light userdata shall never escape our shi!
+		-- This matches how OC wraps it
+		-- TODO: just make our own shi with fields and stuff
+		-- like a component proxy, because this sucks
+		local userMeta = {
+			__gc = function()
+				userdata.free(val)
+			end,
+		}
+
+		local wrapped = {type = "userdata"}
+		for name, m in pairs(userdata.methods(val)) do
+			wrapped[name] = {
+				name = name,
+				proxy = wrapped,
+			}
+			setmetatable(wrapped[name], {
+				__tostring = function() return m.doc or "function" end,
+				__call = function(_, ...)
+					return userdata.invoke(val, name, ...)
+				end,
+			})
+		end
+		return setmetatable(wrapped, userMeta)
+	end
+	return val
+end
+
 local function realInvoke(address, method, ...)
 	local t = {pcall(cinvoke, address, method, ...)}
 	if not _SYNCED and not os.getenv("NN_FAST") then
@@ -83,6 +121,8 @@ local function realInvoke(address, method, ...)
 		print("got", table.unpack(t))
 	end
 
+	for i=1,#t do t[i] = sandboxValue(t[i]) end
+
 	if t[1] then
 		return table.unpack(t, 2)
 	end
@@ -477,6 +517,9 @@ sandbox = {
 	},
 
 	utf8 = utf8,
+
+	-- unsafe, don't care
+	userdata = userdata,
 }
 sandbox._G = sandbox
 

src/main.c

@@ -42,7 +42,7 @@ static nn_Exit sandbox_handler(nn_ComponentRequest *req) {
 		return NN_OK;
 	case NN_COMP_DROP:
 		return NN_OK;
-	case NN_COMP_SIGNAL:
+	case NN_COMP_USERDATA:
 		return NN_OK;
 	}
 	return NN_OK;

src/neonucleus.c

@@ -1064,6 +1064,11 @@ nn_Exit nn_resizeDeviceInfoArray(nn_Context *ctx, nn_DeviceInfoArray *arr, size_
 	return NN_OK;
 }
 
+typedef struct nn_Userdata {
+	void *state;
+	char *compAddress;
+} nn_Userdata;
+
 typedef struct nn_Computer {
 	nn_ComputerState state;
 	nn_Universe *universe;
@@ -1092,6 +1097,7 @@ typedef struct nn_Computer {
 	nn_Architecture archs[NN_MAX_ARCHITECTURES];
 	nn_Signal signals[NN_MAX_SIGNALS];
 	char *users[NN_MAX_USERS];
+	nn_Userdata uservals[NN_MAX_USERDATA];
 } nn_Computer;
 
 nn_Universe *nn_createUniverse(nn_Context *ctx, void *userdata) {
@@ -1220,6 +1226,7 @@ nn_Computer *nn_createComputer(nn_Universe *universe, void *userdata, const char
 	c->idleTimestamp = 0;
 	// set to empty string
 	c->errorBuffer[0] = '\0';
+	for(size_t i = 0; i < NN_MAX_USERDATA; i++) c->uservals[i].state = NULL;
 	return c;
 }
 
@@ -1430,8 +1437,9 @@ void nn_destroyComputer(nn_Computer *computer) {
 		nn_strfree(ctx, computer->users[i]);
 	}
 
+	for(size_t i = 0; i < NN_MAX_USERDATA; i++) nn_freeUserdata(computer, i);
+
 	for(nn_ComponentEntry *c = nn_hashIterate(&computer->components, NULL); c != NULL; c = nn_hashIterate(&computer->components, c)) {
-		nn_signalComponent(c->comp, computer, NN_CSIGUNMOUNTED);
 		nn_dropComponent(c->comp);
 	}
 
@@ -2061,7 +2069,6 @@ nn_Exit nn_mountComponent(nn_Computer *c, nn_Component *comp, int slot, bool sil
 	};
 	if(!nn_hashPut(&c->components, &ent)) return NN_ELIMIT;
 	nn_retainComponent(comp);
-	nn_signalComponent(comp, c, NN_CSIGMOUNTED);
 	if(c->state == NN_RUNNING && !silent) {
 		return nn_pushComponentAdded(c, comp->address, comp->type);
 	}
@@ -2078,7 +2085,6 @@ nn_Exit nn_unmountComponent(nn_Computer *c, const char *address, bool silent) {
 	if(c->state == NN_RUNNING && !silent) {
 		e = nn_pushComponentRemoved(c, address, comp->type);
 	}
-	nn_signalComponent(comp, c, NN_CSIGUNMOUNTED);
 	nn_dropComponent(comp);
 	return e;
 }
@@ -2184,16 +2190,250 @@ nn_Exit nn_invokeComponent(nn_Computer *computer, const char *compAddress, const
 	return NN_OK;
 }
 
-nn_Exit nn_signalComponent(nn_Component *component, nn_Computer *computer, const char *signal) {
+int nn_allocUserdata(nn_Computer *computer, void *state, const char *compAddress) {
-	nn_ComponentRequest req;
+	for(size_t i = 0; i < NN_MAX_USERDATA; i++) {
-	req.ctx = &component->universe->ctx;
+		if(nn_isUserdataValid(computer, i)) continue;
-	req.computer = computer;
+		char *comp = nn_strdup(nn_getComputerContext(computer), compAddress);
-	req.state = component->state;
+		if(comp == NULL) return -1;
-	req.classState = component->classState;
+		computer->uservals[i].state = state;
-	req.compAddress = component->address;
+		computer->uservals[i].compAddress = comp;
-	req.action = NN_COMP_SIGNAL;
+		return i;
-	req.signal = signal;
+	}
-	return component->handler(&req);
+	return -1;
+}
+
+// Frees a userdata index.
+void nn_freeUserdata(nn_Computer *computer, size_t userdata) {
+	if(!nn_isUserdataValid(computer, userdata)) return;
+	nn_Context *ctx = nn_getComputerContext(computer);
+	nn_Userdata *user = computer->uservals + userdata;
+
+	nn_UserdataRequest ureq = {
+		.state = user->state,
+		.action = NN_USER_DROP,
+	};
+
+	nn_Component *c = nn_getComponent(computer, user->compAddress);
+	// really, we should *panic*, as this is a BAD state
+	if(c == NULL) return;
+
+	nn_ComponentRequest creq = {
+		.ctx = ctx,
+		.computer = computer,
+		.state = c->state,
+		.classState = c->classState,
+		.compAddress = c->address,
+		.action = NN_COMP_USERDATA,
+		.methodIdx = 0,
+		.user = &ureq,
+	};
+
+	// errors in here are catastrophic
+	c->handler(&creq);
+
+	user->state = NULL;
+	nn_strfree(ctx, user->compAddress);
+}
+
+// Returns whether the userdata index is valid
+bool nn_isUserdataValid(nn_Computer *computer, size_t userdata) {
+	if(userdata >= NN_MAX_USERDATA) return false;
+	return computer->uservals[userdata].state != NULL;
+}
+
+// If compAddress is correct and userdata is valid, returns the state pointer.
+// If not, returns NULL, to prevent UB.
+void *nn_unwrapUserdata(nn_Computer *computer, size_t userdata, const char *compAddress) {
+	if(!nn_isUserdataValid(computer, userdata)) return NULL;
+	nn_Userdata user = computer->uservals[userdata];
+	if(nn_strcmp(user.compAddress, compAddress) != 0) return NULL;
+	return user.state;
+}
+
+// gets the component address which manages this userdata
+const char *nn_getUserdataComponent(nn_Computer *computer, size_t userdata) {
+	if(!nn_isUserdataValid(computer, userdata)) return NULL;
+	return computer->uservals[userdata].compAddress;
+}
+
+// Gets information about a method of this userdata, by index.
+// If idx is out of bounds, this returns true, which means to stop iteration.
+// If method->name is NULL, the method should be skipped.
+bool nn_getUserdataMethod(nn_Computer *computer, size_t userdata, size_t idx, nn_Method *method) {
+	if(!nn_isUserdataValid(computer, userdata)) return true;
+	nn_Context *ctx = nn_getComputerContext(computer);
+	nn_Userdata *user = computer->uservals + userdata;
+
+	nn_UserdataRequest ureq = {
+		.state = user->state,
+		.action = NN_USER_GETMETHOD,
+		.getmethod.method = method,
+		.getmethod.idx = idx,
+	};
+
+	nn_Component *c = nn_getComponent(computer, user->compAddress);
+	// really, we should *panic*, as this is a BAD state
+	if(c == NULL) return true;
+
+	nn_ComponentRequest creq = {
+		.ctx = ctx,
+		.computer = computer,
+		.state = c->state,
+		.classState = c->classState,
+		.compAddress = c->address,
+		.action = NN_COMP_USERDATA,
+		.methodIdx = 0,
+		.user = &ureq,
+	};
+
+	// errors in here are catastrophic
+	if(c->handler(&creq)) return true;
+	return ureq.getmethod.method == NULL;
+}
+
+// Invokes a method on some userdata, same semantics as nn_invokeComponent
+nn_Exit nn_invokeUserdata(nn_Computer *computer, size_t userdata, const char *method) {
+	if(!nn_isUserdataValid(computer, userdata)) return true;
+	nn_Context *ctx = nn_getComputerContext(computer);
+	nn_Userdata *user = computer->uservals + userdata;
+
+	nn_UserdataRequest ureq = {
+		.state = user->state,
+		.action = NN_USER_INVOKE,
+		.invoke.method = method,
+		.invoke.returnCount = 0,
+	};
+
+	nn_Component *c = nn_getComponent(computer, user->compAddress);
+	// really, we should *panic*, as this is a BAD state
+	if(c == NULL) return true;
+
+	nn_ComponentRequest creq = {
+		.ctx = ctx,
+		.computer = computer,
+		.state = c->state,
+		.classState = c->classState,
+		.compAddress = c->address,
+		.action = NN_COMP_USERDATA,
+		.methodIdx = 0,
+		.user = &ureq,
+	};
+
+	// prepare stack for call
+	while(nn_getstacksize(computer) > 0) {
+		if(!nn_isnull(computer, nn_getstacksize(computer) - 1)) break;
+		nn_pop(computer);
+	}
+
+	// errors in here are catastrophic
+	nn_Exit e = c->handler(&creq);
+	if(e) {
+		if(e != NN_EBADCALL) nn_setErrorFromExit(computer, e);
+		nn_clearstack(computer);
+		return e;
+	}
+
+	size_t endOfTrim = computer->stackSize - ureq.invoke.returnCount;
+	for(size_t i = 0; i < endOfTrim; i++) {
+		nn_dropValue(computer->callstack[i]);
+	}
+	for(size_t i = endOfTrim; i < computer->stackSize; i++) {
+		computer->callstack[i - endOfTrim] = computer->callstack[i];
+	}
+	computer->stackSize = ureq.invoke.returnCount;
+
+	if(nn_getEnergy(computer) <= 0) {
+		nn_setError(computer, "out of energy");
+		return NN_EBADCALL;
+	}
+
+	return NN_OK;
+}
+
+// Serializes the userdata into a buffer and pushes it as a string.
+// Make sure to keep track of its index and component address!
+nn_Exit nn_serializeUserdata(nn_Computer *computer, size_t userdata) {
+	if(!nn_isUserdataValid(computer, userdata)) return true;
+	nn_Context *ctx = nn_getComputerContext(computer);
+	nn_Userdata *user = computer->uservals + userdata;
+
+	nn_UserdataRequest ureq = {
+		.state = user->state,
+		.action = NN_USER_SERIALIZE,
+	};
+
+	nn_Component *c = nn_getComponent(computer, user->compAddress);
+	// really, we should *panic*, as this is a BAD state
+	if(c == NULL) return true;
+
+	nn_ComponentRequest creq = {
+		.ctx = ctx,
+		.computer = computer,
+		.state = c->state,
+		.classState = c->classState,
+		.compAddress = c->address,
+		.action = NN_COMP_USERDATA,
+		.methodIdx = 0,
+		.user = &ureq,
+	};
+
+	// errors in here are catastrophic
+	return c->handler(&creq);
+}
+
+// Deserializes userdata at a particular index.
+// NOTE: if the component does not exist, or the userdata index is already taken, this errors.
+nn_Exit nn_deserializeUserdata(nn_Computer *computer, size_t userdata, const char *compAddress, const char *buf, size_t len) {
+	if(userdata >= NN_MAX_USERDATA) {
+		nn_setError(computer, "invalid slot");
+		return NN_EBADCALL;
+	}
+
+	if(nn_isUserdataValid(computer, userdata)) {
+		nn_setError(computer, "slot taken");
+		return NN_EBADCALL;
+	}
+
+	nn_Component *c = nn_getComponent(computer, compAddress);
+	if(c == NULL) {
+		nn_setError(computer, "no such component");
+		return NN_EBADCALL;
+	}
+	
+	nn_Context *ctx = nn_getComputerContext(computer);
+	nn_Userdata *user = computer->uservals + userdata;
+
+	nn_UserdataRequest ureq = {
+		.state = user->state,
+		.action = NN_USER_DESERIALIZE,
+		.deserialize.data = buf,
+		.deserialize.len = len,
+	};
+
+	nn_ComponentRequest creq = {
+		.ctx = ctx,
+		.computer = computer,
+		.state = c->state,
+		.classState = c->classState,
+		.compAddress = c->address,
+		.action = NN_COMP_USERDATA,
+		.methodIdx = 0,
+		.user = &ureq,
+	};
+
+	char *compAddr = nn_strdup(ctx, compAddress);
+	if(compAddr == NULL) return NN_ENOMEM;
+
+	// errors in here are catastrophic
+	nn_Exit e = c->handler(&creq);
+	if(e) {
+		nn_strfree(ctx, compAddr);
+		return e;
+	}
+
+	user->state = ureq.state;
+	user->compAddress = compAddr;
+	return NN_OK;
 }
 
 static void nn_retainValue(nn_Value val) {
@@ -3906,7 +4146,7 @@ typedef enum nn_CompNum {
 
 static nn_Exit nn_computerHandler(nn_ComponentRequest *req) {
 	if(req->action == NN_COMP_DROP) return NN_OK;
-	if(req->action == NN_COMP_SIGNAL) return NN_OK;
+	if(req->action == NN_COMP_USERDATA) return NN_OK;
 	nn_Computer *src = req->computer;
 	if(src) nn_setError(src, "computer: not implemented yet");
 	return NN_EBADCALL;
@@ -3964,7 +4204,7 @@ typedef struct nn_EEState {
 } nn_EEState;
 
 static nn_Exit nn_eepromHandler(nn_ComponentRequest *req) {
-	if(req->action == NN_COMP_SIGNAL) return NN_OK;
+	if(req->action == NN_COMP_USERDATA) return NN_OK;
 	if(req->action == NN_COMP_CHECKMETHOD) return NN_OK;
 	nn_EEState *state = req->classState;
 	nn_EEPROMRequest ereq;
@@ -4230,7 +4470,7 @@ static nn_Exit nn_fsPathCheck(nn_Computer *C, char buf[NN_MAX_PATH], const char
 }
 
 static nn_Exit nn_fsHandler(nn_ComponentRequest *req) {
-	if(req->action == NN_COMP_SIGNAL) return NN_OK;
+	if(req->action == NN_COMP_USERDATA) return NN_OK;
 	if(req->action == NN_COMP_CHECKMETHOD) return NN_OK;
 	nn_Context *ctx = req->ctx;
 	nn_FSState *state = req->classState;
@@ -4650,7 +4890,7 @@ static nn_Exit nn_drvHandler(nn_ComponentRequest *request) {
 	dreq.drv = &state->drive;
 	nn_Exit e;
 
-	if(request->action == NN_COMP_SIGNAL) return NN_OK;
+	if(request->action == NN_COMP_USERDATA) return NN_OK;
 	if(request->action == NN_COMP_CHECKMETHOD) return NN_OK;
 
 	if(request->action == NN_COMP_DROP) {
@@ -4850,7 +5090,7 @@ static nn_Exit nn_flashHandler(nn_ComponentRequest *request) {
 	freq.flash = &state->flash;
 	nn_Exit e;
 
-	if(request->action == NN_COMP_SIGNAL) return NN_OK;
+	if(request->action == NN_COMP_USERDATA) return NN_OK;
 	if(request->action == NN_COMP_CHECKMETHOD) return NN_OK;
 
 	if(request->action == NN_COMP_DROP) {
@@ -5069,7 +5309,7 @@ typedef struct nn_ScreenClassState {
 } nn_ScreenClassState;
 
 static nn_Exit nn_screenHandler(nn_ComponentRequest *req) {
-    if(req->action == NN_COMP_SIGNAL) return NN_OK;
+    if(req->action == NN_COMP_USERDATA) return NN_OK;
     nn_Context *ctx = req->ctx;
     nn_ScreenClassState *cls = req->classState;
     nn_Computer *C = req->computer;
@@ -5335,7 +5575,7 @@ typedef struct nn_GPUClassState {
 
 static nn_Exit nn_gpuHandler(nn_ComponentRequest *req) {
     if(req->action == NN_COMP_CHECKMETHOD) return NN_OK;
-    if(req->action == NN_COMP_SIGNAL) return NN_OK;
+    if(req->action == NN_COMP_USERDATA) return NN_OK;
     nn_Context *ctx = req->ctx;
     nn_GPUClassState *cls = req->classState;
     nn_Computer *C = req->computer;
@@ -6125,8 +6365,15 @@ nn_DataCard nn_defaultDataCards[3] = {
 		.assymetricCost = 10.0,
 	},
 };
+
+typedef struct nn_DataKey {
+	bool isPublic;
+	unsigned short bitlen;
+	size_t bytelen;
+	char bytes[];
+} nn_DataKey;
+
 static nn_Exit nn_dataHandler(nn_ComponentRequest *req) {
-	if(req->action == NN_COMP_SIGNAL) return NN_OK;
 	nn_Context *ctx = req->ctx;
 	nn_DataState *state = req->classState;
 	nn_Computer *C = req->computer;
@@ -6150,6 +6397,84 @@ static nn_Exit nn_dataHandler(nn_ComponentRequest *req) {
 		return NN_OK;
 	}
 	
+	if(req->action == NN_COMP_USERDATA) {
+		nn_UserdataRequest *user = req->user;
+		nn_DataKey *key = user->state;
+
+		if(user->action == NN_USER_DROP) {
+			nn_free(ctx, key, sizeof(*key) + key->bytelen);
+			return NN_OK;
+		}
+
+		if(user->action == NN_USER_SERIALIZE) {
+			// its assumed bytelen is not ridiculous
+			size_t serlen = 2 + key->bytelen;
+			NN_VLA(unsigned char, ser, serlen);
+			unsigned short bitsAndPub = (key->bitlen * 2) + (key->isPublic ? 1 : 0);
+			ser[0] = (bitsAndPub >> 0) & 0xFF;
+			ser[1] = (bitsAndPub >> 8) & 0xFF;
+			nn_memcpy(ser + 2, key->bytes, key->bytelen);
+			return nn_pushlstring(C, (const char *)ser, serlen);
+		}
+
+		if(user->action == NN_USER_DESERIALIZE) {
+			size_t serlen = user->deserialize.len;
+			const unsigned char *ser = (const unsigned char *)user->deserialize.data;
+			size_t bytelen = serlen - 2;
+			unsigned short bitsAndPub = ((unsigned short)ser[0]) + (((unsigned short)ser[1]) << 8);
+			key = nn_alloc(ctx, sizeof(*key) + bytelen);
+			if(key == NULL) return NN_ENOMEM;
+			key->isPublic = (bitsAndPub&1) != 0;
+			key->bitlen = bitsAndPub/2;
+			key->bytelen = bytelen;
+			nn_memcpy(key->bytes, ser + 2, key->bytelen);
+			user->state = key;
+			return NN_OK;
+		}
+
+		if(user->action == NN_USER_GETMETHOD) {
+			size_t idx = user->getmethod.idx;
+			nn_Method *m = user->getmethod.method;
+			if(idx == 0) {
+				m->name = "serialize";
+				m->doc = "function(): string - Serializes the key to its array of bytes";
+				m->flags = NN_DIRECT;
+			} else if(idx == 1) {
+				m->name = "keyType";
+				m->doc = "function(): string - Gets the type of the key (ec-public or ec-private)";
+				m->flags = NN_DIRECT;
+			} else if(idx == 2) {
+				m->name = "isPublic";
+				m->doc = "function(): boolean - Returns whether this key is public or not";
+				m->flags = NN_DIRECT;
+			} else {
+				user->getmethod.method = NULL;
+			}
+			return NN_OK;
+		}
+
+		if(user->action == NN_USER_INVOKE) {
+			const char *method = user->invoke.method;
+			if(nn_strcmp(method, "isPublic") == 0) {
+				user->invoke.returnCount = 1;
+				return nn_pushbool(C, key->isPublic);
+			}
+			if(nn_strcmp(method, "keyType") == 0) {
+				user->invoke.returnCount = 1;
+				return nn_pushstring(C, key->isPublic ? "ec-public" : "ec-private");
+			}
+			if(nn_strcmp(method, "serialize") == 0) {
+				user->invoke.returnCount = 1;
+				return nn_pushlstring(C, key->bytes, key->bytelen);
+			}
+
+			nn_setError(C, "no such method");
+			return NN_EBADCALL;
+		}
+
+		return NN_OK;
+	}
+
 	nn_DataCardRequest dreq;
 	dreq.ctx = ctx;
 	dreq.computer = C;
@@ -6332,6 +6657,26 @@ static nn_Exit nn_dataHandler(nn_ComponentRequest *req) {
 		return NN_OK;
 	}
 
+	if(method == NN_DATANUM_GENKEYPAIR) {
+		e = nn_defaultinteger(C, 0, 256);
+		if(e) return e;
+		if(nn_checkinteger(C, 0, "bad argument #1 (integer expected)")) return NN_EBADCALL;
+		size_t bitLen = nn_tointeger(C, 0);
+		if(bitLen != 256 && bitLen != 384) {
+			nn_setError(C, "invalid bit length (only 256-bit and 384-bit are supported)");
+			return NN_EBADCALL;
+		}
+		// TODO: this is test code, no OOM check. Implement the correct version and make sure it handles OOMs correctly
+		size_t keylen = bitLen / 8;
+		nn_DataKey *key = nn_alloc(ctx, sizeof(*key) + keylen);
+		key->isPublic = true;
+		key->bitlen = bitLen;
+		key->bytelen = keylen;
+		nn_memset(key->bytes, 'A', key->bytelen);
+		req->returnCount = 1;
+		return nn_pushuserdata(C, nn_allocUserdata(C, key, req->compAddress));
+	}
+
 	if(C) nn_setError(C, "data: not implemented yet");
 	return NN_EBADCALL;
 }
@@ -6415,7 +6760,7 @@ typedef struct nn_ModemState {
 } nn_ModemState;
 
 static nn_Exit nn_modemHandler(nn_ComponentRequest *req) {
-	if(req->action == NN_COMP_SIGNAL) return NN_OK;
+	if(req->action == NN_COMP_USERDATA) return NN_OK;
 	nn_Context *ctx = req->ctx;
 	nn_ModemState *state = req->classState;
 	nn_Computer *C = req->computer;

src/neonucleus.h

@@ -659,13 +659,6 @@ typedef struct nn_Method {
 	nn_MethodFlags flags;
 } nn_Method;
 
-// component signals
-
-// mounted
-#define NN_CSIGMOUNTED "mounted"
-// unmounted
-#define NN_CSIGUNMOUNTED "unmounted"
-
 typedef enum nn_ComponentAction {
 	// component dropped
 	NN_COMP_DROP,
@@ -674,10 +667,38 @@ typedef enum nn_ComponentAction {
 	// checking if component method is enabled
 	// (may be locked by tier)
 	NN_COMP_CHECKMETHOD,
-	// signal sent to the machine
+	// userdata request
-	NN_COMP_SIGNAL,
+	NN_COMP_USERDATA,
 } nn_ComponentAction;
 
+typedef enum nn_UserdataAction {
+	NN_USER_DROP,
+	NN_USER_SERIALIZE,
+	NN_USER_DESERIALIZE,
+	NN_USER_GETMETHOD,
+	NN_USER_INVOKE,
+} nn_UserdataAction;
+
+typedef struct nn_UserdataRequest {
+	void *state;
+	nn_UserdataAction action;
+	union {
+		struct {
+			const char *data;
+			size_t len;
+		} deserialize;
+		struct {
+			size_t idx;
+			// set to NULL if idx is out of bounds
+			nn_Method *method;
+		} getmethod;
+		struct {
+			const char *method;
+			size_t returnCount;
+		} invoke;
+	};
+} nn_UserdataRequest;
+
 typedef struct nn_ComponentRequest {
 	nn_Context *ctx;
 	nn_Computer *computer;
@@ -692,8 +713,7 @@ typedef struct nn_ComponentRequest {
 		size_t returnCount;
 		// method enabled
 		bool methodEnabled;
-		// signal invocation
+		nn_UserdataRequest *user;
-		const char *signal;
 	};
 } nn_ComponentRequest;