Make invalid items unusable

Source/CMakeLists.txt

@@ -55,6 +55,8 @@ set(libdevilutionx_SRCS
   towners.cpp
   track.cpp
 
+  common/validation.cpp
+
   controls/axis_direction.cpp
   controls/controller.cpp
   controls/controller_buttons.cpp

Source/common/validation.cpp

@@ -0,0 +1,121 @@
+/**
+ * @file common/validation.cpp
+ *
+ * Implementation of functions for validation of player and item data.
+ */
+
+#include "common/validation.h"
+
+#include <cstdint>
+
+#include "items.h"
+#include "monstdat.h"
+
+namespace devilution {
+
+namespace {
+
+bool hasMultipleFlags(uint16_t flags)
+{
+	return (flags & (flags - 1)) > 0;
+}
+
+} // namespace
+
+bool IsCreationFlagComboValid(uint16_t iCreateInfo)
+{
+	iCreateInfo = iCreateInfo & ~CF_LEVEL;
+	const bool isTownItem = (iCreateInfo & CF_TOWN) != 0;
+	const bool isPregenItem = (iCreateInfo & CF_PREGEN) != 0;
+	const bool isUsefulItem = (iCreateInfo & CF_USEFUL) == CF_USEFUL;
+
+	if (isPregenItem) {
+		// Pregen flags are discarded when an item is picked up, therefore impossible to have in the inventory
+		return false;
+	}
+	if (isUsefulItem && (iCreateInfo & ~CF_USEFUL) != 0)
+		return false;
+	if (isTownItem && hasMultipleFlags(iCreateInfo)) {
+		// Items from town can only have 1 towner flag
+		return false;
+	}
+	return true;
+}
+
+bool IsTownItemValid(uint16_t iCreateInfo, uint8_t maxCharacterLevel)
+{
+	const uint8_t level = iCreateInfo & CF_LEVEL;
+	const bool isBoyItem = (iCreateInfo & CF_BOY) != 0;
+	const uint8_t maxTownItemLevel = 30;
+
+	// Wirt items in multiplayer are equal to the level of the player, therefore they cannot exceed the max character level
+	if (isBoyItem && level <= maxCharacterLevel)
+		return true;
+
+	return level <= maxTownItemLevel;
+}
+
+bool IsUniqueMonsterItemValid(uint16_t iCreateInfo, uint32_t dwBuff)
+{
+	const uint8_t level = iCreateInfo & CF_LEVEL;
+
+	// Check all unique monster levels to see if they match the item level
+	for (const UniqueMonsterData &uniqueMonsterData : UniqueMonstersData) {
+		const auto &uniqueMonsterLevel = static_cast<uint8_t>(MonstersData[uniqueMonsterData.mtype].level);
+
+		if (IsAnyOf(uniqueMonsterData.mtype, MT_DEFILER, MT_NAKRUL, MT_HORKDMN)) {
+			// These monsters don't use their mlvl for item generation
+			continue;
+		}
+
+		if (level == uniqueMonsterLevel) {
+			// If the ilvl matches the mlvl, we confirm the item is legitimate
+			return true;
+		}
+	}
+
+	return false;
+}
+
+bool IsDungeonItemValid(uint16_t iCreateInfo, uint32_t dwBuff)
+{
+	const uint8_t level = iCreateInfo & CF_LEVEL;
+	const bool isHellfireItem = (dwBuff & CF_HELLFIRE) != 0;
+
+	// Check all monster levels to see if they match the item level
+	for (int16_t i = 0; i < static_cast<int16_t>(NUM_MTYPES); i++) {
+		const auto &monsterData = MonstersData[i];
+		auto monsterLevel = static_cast<uint8_t>(monsterData.level);
+
+		if (i != MT_DIABLO && monsterData.availability == MonsterAvailability::Never) {
+			// Skip monsters that are unable to appear in the game
+			continue;
+		}
+
+		if (i == MT_DIABLO && !isHellfireItem) {
+			// Adjust The Dark Lord's mlvl if the item isn't a Hellfire item to match the Diablo mlvl
+			monsterLevel -= 15;
+		}
+
+		if (level == monsterLevel) {
+			// If the ilvl matches the mlvl, we confirm the item is legitimate
+			return true;
+		}
+	}
+
+	if (isHellfireItem) {
+		uint8_t hellfireMaxDungeonLevel = 24;
+
+		// Hellfire adjusts the currlevel minus 7 in dungeon levels 20-24 for generating items
+		hellfireMaxDungeonLevel -= 7;
+		return level <= (hellfireMaxDungeonLevel * 2);
+	}
+
+	uint8_t diabloMaxDungeonLevel = 16;
+
+	// Diablo doesn't have containers that drop items in dungeon level 16, therefore we decrement by 1
+	diabloMaxDungeonLevel--;
+	return level <= (diabloMaxDungeonLevel * 2);
+}
+
+} // namespace devilution

Source/common/validation.h

@@ -0,0 +1,17 @@
+/**
+ * @file common/validation.h
+ *
+ * Interface of functions for validation of player and item data.
+ */
+#pragma once
+
+#include <cstdint>
+
+namespace devilution {
+
+bool IsCreationFlagComboValid(uint16_t iCreateInfo);
+bool IsTownItemValid(uint16_t iCreateInfo, uint8_t maxCharacterLevel);
+bool IsUniqueMonsterItemValid(uint16_t iCreateInfo, uint32_t dwBuff);
+bool IsDungeonItemValid(uint16_t iCreateInfo, uint32_t dwBuff);
+
+} // namespace devilution

Source/items.cpp

@@ -512,13 +512,35 @@ void CalcSelfItems(Player &player)
 		const int currdex = std::max(0, da + player._pBaseDex);
 
 		changeflag = false;
+		// Iterate over equipped items and remove stat bonuses if they are not valid
 		for (Item &equipment : EquippedPlayerItemsRange(player)) {
 			if (!equipment._iStatFlag)
 				continue;
 
-			if (currstr >= equipment._iMinStr
-			    && currmag >= equipment._iMinMag
-			    && currdex >= equipment._iMinDex)
+			bool isValid = true;
+
+			if (equipment.IDidx != IDI_GOLD) {
+				if (!IsCreationFlagComboValid(equipment._iCreateInfo))
+					isValid = false;
+			}
+
+			if ((equipment._iCreateInfo & CF_TOWN) != 0) {
+				if (!IsTownItemValid(equipment._iCreateInfo, player.getMaxCharacterLevel()))
+					isValid = false;
+			} else if ((equipment._iCreateInfo & CF_USEFUL) == CF_UPER15) {
+				if (!IsUniqueMonsterItemValid(equipment._iCreateInfo, equipment.dwBuff))
+					isValid = false;
+			} else {
+				if (!IsDungeonItemValid(equipment._iCreateInfo, equipment.dwBuff))
+					isValid = false;
+			}
+
+			if (currstr < equipment._iMinStr
+			    || currmag < equipment._iMinMag
+			    || currdex < equipment._iMinDex)
+				isValid = false;
+
+			if (isValid)
 				continue;
 
 			changeflag = true;

Source/msg.cpp

@@ -1044,7 +1044,7 @@ bool IsPItemValid(const TCmdPItem &message, const Player &player)
 		if (idx != IDI_GOLD)
 			ValidateField(creationFlags, IsCreationFlagComboValid(creationFlags));
 		if ((creationFlags & CF_TOWN) != 0)
-			ValidateField(creationFlags, IsTownItemValid(creationFlags, player));
+			ValidateField(creationFlags, IsTownItemValid(creationFlags, player.getMaxCharacterLevel()));
 		else if ((creationFlags & CF_USEFUL) == CF_UPER15)
 			ValidateFields(creationFlags, dwBuff, IsUniqueMonsterItemValid(creationFlags, dwBuff));
 		else if ((dwBuff & CF_HELLFIRE) != 0 && AllItemsList[idx].iMiscId == IMISC_BOOK)

Source/pack.cpp

@@ -7,6 +7,7 @@
 
 #include <cstdint>
 
+#include "common/validation.h"
 #include "engine/random.hpp"
 #include "init.h"
 #include "loadsave.h"
@@ -75,109 +76,8 @@ void VerifyGoldSeeds(Player &player)
 	}
 }
 
-bool hasMultipleFlags(uint16_t flags)
-{
-	return (flags & (flags - 1)) > 0;
-}
-
 } // namespace
 
-bool IsCreationFlagComboValid(uint16_t iCreateInfo)
-{
-	iCreateInfo = iCreateInfo & ~CF_LEVEL;
-	const bool isTownItem = (iCreateInfo & CF_TOWN) != 0;
-	const bool isPregenItem = (iCreateInfo & CF_PREGEN) != 0;
-	const bool isUsefulItem = (iCreateInfo & CF_USEFUL) == CF_USEFUL;
-
-	if (isPregenItem) {
-		// Pregen flags are discarded when an item is picked up, therefore impossible to have in the inventory
-		return false;
-	}
-	if (isUsefulItem && (iCreateInfo & ~CF_USEFUL) != 0)
-		return false;
-	if (isTownItem && hasMultipleFlags(iCreateInfo)) {
-		// Items from town can only have 1 towner flag
-		return false;
-	}
-	return true;
-}
-
-bool IsTownItemValid(uint16_t iCreateInfo, const Player &player)
-{
-	const uint8_t level = iCreateInfo & CF_LEVEL;
-	const bool isBoyItem = (iCreateInfo & CF_BOY) != 0;
-	const uint8_t maxTownItemLevel = 30;
-
-	// Wirt items in multiplayer are equal to the level of the player, therefore they cannot exceed the max character level
-	if (isBoyItem && level <= player.getMaxCharacterLevel())
-		return true;
-
-	return level <= maxTownItemLevel;
-}
-
-bool IsUniqueMonsterItemValid(uint16_t iCreateInfo, uint32_t dwBuff)
-{
-	const uint8_t level = iCreateInfo & CF_LEVEL;
-
-	// Check all unique monster levels to see if they match the item level
-	for (const UniqueMonsterData &uniqueMonsterData : UniqueMonstersData) {
-		const auto &uniqueMonsterLevel = static_cast<uint8_t>(MonstersData[uniqueMonsterData.mtype].level);
-
-		if (IsAnyOf(uniqueMonsterData.mtype, MT_DEFILER, MT_NAKRUL, MT_HORKDMN)) {
-			// These monsters don't use their mlvl for item generation
-			continue;
-		}
-
-		if (level == uniqueMonsterLevel) {
-			// If the ilvl matches the mlvl, we confirm the item is legitimate
-			return true;
-		}
-	}
-
-	return false;
-}
-
-bool IsDungeonItemValid(uint16_t iCreateInfo, uint32_t dwBuff)
-{
-	const uint8_t level = iCreateInfo & CF_LEVEL;
-	const bool isHellfireItem = (dwBuff & CF_HELLFIRE) != 0;
-
-	// Check all monster levels to see if they match the item level
-	for (int16_t i = 0; i < static_cast<int16_t>(NUM_MTYPES); i++) {
-		const auto &monsterData = MonstersData[i];
-		auto monsterLevel = static_cast<uint8_t>(monsterData.level);
-
-		if (i != MT_DIABLO && monsterData.availability == MonsterAvailability::Never) {
-			// Skip monsters that are unable to appear in the game
-			continue;
-		}
-
-		if (i == MT_DIABLO && !isHellfireItem) {
-			// Adjust The Dark Lord's mlvl if the item isn't a Hellfire item to match the Diablo mlvl
-			monsterLevel -= 15;
-		}
-
-		if (level == monsterLevel) {
-			// If the ilvl matches the mlvl, we confirm the item is legitimate
-			return true;
-		}
-	}
-
-	if (isHellfireItem) {
-		uint8_t hellfireMaxDungeonLevel = 24;
-
-		// Hellfire adjusts the currlevel minus 7 in dungeon levels 20-24 for generating items
-		hellfireMaxDungeonLevel -= 7;
-		return level <= (hellfireMaxDungeonLevel * 2);
-	}
-
-	uint8_t diabloMaxDungeonLevel = 16;
-
-	// Diablo doesn't have containers that drop items in dungeon level 16, therefore we decrement by 1
-	diabloMaxDungeonLevel--;
-	return level <= (diabloMaxDungeonLevel * 2);
-}
-
 bool RecreateHellfireSpellBook(const Player &player, const TItem &packedItem, Item *item)
 {
 	Item spellBook {};
@@ -545,7 +445,7 @@ bool UnPackNetItem(const Player &player, const ItemNetPack &packedItem, Item &it
 	if (idx != IDI_GOLD)
 		ValidateField(creationFlags, IsCreationFlagComboValid(creationFlags));
 	if ((creationFlags & CF_TOWN) != 0)
-		ValidateField(creationFlags, IsTownItemValid(creationFlags, player));
+		ValidateField(creationFlags, IsTownItemValid(creationFlags, player.getMaxCharacterLevel()));
 	else if ((creationFlags & CF_USEFUL) == CF_UPER15)
 		ValidateFields(creationFlags, dwBuff, IsUniqueMonsterItemValid(creationFlags, dwBuff));
 	else if ((dwBuff & CF_HELLFIRE) != 0 && AllItemsList[idx].iMiscId == IMISC_BOOK)

Source/pack.h

@@ -142,10 +142,6 @@ struct PlayerNetPack {
 };
 #pragma pack(pop)
 
-bool IsCreationFlagComboValid(uint16_t iCreateInfo);
-bool IsTownItemValid(uint16_t iCreateInfo, const Player &player);
-bool IsUniqueMonsterItemValid(uint16_t iCreateInfo, uint32_t dwBuff);
-bool IsDungeonItemValid(uint16_t iCreateInfo, uint32_t dwBuff);
 bool RecreateHellfireSpellBook(const Player &player, const TItem &packedItem, Item *item = nullptr);
 void PackPlayer(PlayerPack &pPack, const Player &player);
 void UnPackPlayer(const PlayerPack &pPack, Player &player);

Source/player.h

@@ -11,6 +11,7 @@
 #include <algorithm>
 #include <array>
 
+#include "common/validation.h"
 #include "diablo.h"
 #include "engine.h"
 #include "engine/actor_position.hpp"
@@ -400,6 +401,22 @@ struct Player {
 
 	bool CanUseItem(const Item &item) const
 	{
+		if (item.IDidx != IDI_GOLD) {
+			if (!IsCreationFlagComboValid(item._iCreateInfo))
+				return false;
+		}
+
+		if ((item._iCreateInfo & CF_TOWN) != 0) {
+			if (!IsTownItemValid(item._iCreateInfo, getMaxCharacterLevel()))
+				return false;
+		} else if ((item._iCreateInfo & CF_USEFUL) == CF_UPER15) {
+			if (!IsUniqueMonsterItemValid(item._iCreateInfo, item.dwBuff))
+				return false;
+		} else {
+			if (!IsDungeonItemValid(item._iCreateInfo, item.dwBuff))
+				return false;
+		}
+
 		return _pStrength >= item._iMinStr
 		    && _pMagic >= item._iMinMag
 		    && _pDexterity >= item._iMinDex;

test/player_test.cpp

@@ -189,6 +189,7 @@ TEST(Player, CreatePlayer)
 	ASSERT_TRUE(HaveSpawn() || HaveDiabdat());
 
 	LoadPlayerDataFiles();
+	LoadMonsterData();
 	LoadItemData();
 	Players.resize(1);
 	CreatePlayer(Players[0], HeroClass::Rogue);

test/writehero_test.cpp

@@ -386,6 +386,7 @@ TEST(Writehero, pfile_write_hero)
 
 	LoadSpellData();
 	LoadPlayerDataFiles();
+	LoadMonsterData();
 	LoadItemData();
 	_uiheroinfo info {};
 	info.heroclass = HeroClass::Rogue;