store world hostname and resolve at runtime

4 files changed, 157 insertions, 12 deletions

diff --git a/src/database.cc b/src/database.cc
index b873732..f79bd82 100644
--- a/src/database.cc
+++ b/src/database.cc
@@ -236,7 +236,7 @@ bool GetWorlds(DynamicArray<TWorld> *Worlds){
 bool GetWorldConfig(int WorldID, TWorldConfig *WorldConfig){
 	ASSERT(WorldConfig != NULL);
 	sqlite3_stmt *Stmt = PrepareQuery(
-			"SELECT Type, RebootTime, IPAddress, Port, MaxPlayers,"
+			"SELECT Type, RebootTime, Host, Port, MaxPlayers,"
 				" PremiumPlayerBuffer, MaxNewbies, PremiumNewbieBuffer"
 			" FROM Worlds WHERE WorldID = ?1");
 	if(Stmt == NULL){
@@ -255,9 +255,16 @@ bool GetWorldConfig(int WorldID, TWorldConfig *WorldConfig){
 		return false;
 	}
 
+	int IPAddress;
+	const char *HostName = (const char*)sqlite3_column_text(Stmt, 2);
+	if(HostName == NULL || !ResolveHostName(HostName, &IPAddress)){
+		LOG_ERR("Failed to resolve world %d host name \"%s\"", WorldID, HostName);
+		return false;
+	}
+
 	WorldConfig->Type					= sqlite3_column_int(Stmt, 0);
 	WorldConfig->RebootTime				= sqlite3_column_int(Stmt, 1);
-	WorldConfig->IPAddress				= sqlite3_column_int(Stmt, 2);
+	WorldConfig->IPAddress				= IPAddress;
 	WorldConfig->Port					= sqlite3_column_int(Stmt, 3);
 	WorldConfig->MaxPlayers				= sqlite3_column_int(Stmt, 4);
 	WorldConfig->PremiumPlayerBuffer	= sqlite3_column_int(Stmt, 5);
@@ -483,7 +490,7 @@ bool ActivatePendingPremiumDays(int AccountID){
 
 bool GetCharacterEndpoints(int AccountID, DynamicArray<TCharacterEndpoint> *Characters){
 	sqlite3_stmt *Stmt = PrepareQuery(
-			"SELECT C.Name, W.Name, W.IPAddress, W.Port"
+			"SELECT C.Name, W.Name, W.Host, W.Port"
 			" FROM Characters AS C"
 			" INNER JOIN Worlds AS W ON W.WorldID = C.WorldID"
 			" WHERE C.AccountID = ?1");
@@ -499,12 +506,20 @@ bool GetCharacterEndpoints(int AccountID, DynamicArray<TCharacterEndpoint> *Char
 	}
 
 	while(sqlite3_step(Stmt) == SQLITE_ROW){
+		int WorldAddress;
+		const char *CharacterName = (const char*)sqlite3_column_text(Stmt, 0);
+		const char *WorldName = (const char*)sqlite3_column_text(Stmt, 1);
+		const char *HostName = (const char*)sqlite3_column_text(Stmt, 2);
+		if(HostName == NULL || !ResolveHostName(HostName, &WorldAddress)){
+			LOG_ERR("Failed to resolve world \"%s\" host name \"%s\" for character \"%s\"",
+					WorldName, HostName, CharacterName);
+			continue;
+		}
+
 		TCharacterEndpoint Character = {};
-		StringCopy(Character.Name, sizeof(Character.Name),
-				(const char*)sqlite3_column_text(Stmt, 0));
-		StringCopy(Character.WorldName, sizeof(Character.WorldName),
-				(const char*)sqlite3_column_text(Stmt, 1));
-		Character.WorldAddress = sqlite3_column_int(Stmt, 2);
+		StringCopy(Character.Name, sizeof(Character.Name), CharacterName);
+		StringCopy(Character.WorldName, sizeof(Character.WorldName), WorldName);
+		Character.WorldAddress = WorldAddress;
 		Character.WorldPort = sqlite3_column_int(Stmt, 3);
 		Characters->Push(Character);
 	}
diff --git a/src/hostcache.cc b/src/hostcache.cc
new file mode 100644
index 0000000..5d5d46a
--- /dev/null
+++ b/src/hostcache.cc
@@ -0,0 +1,105 @@
+#include "querymanager.hh"
+
+// TODO(fusion): Support windows eventually?
+#if OS_LINUX
+#	include <netdb.h>
+#else
+#	error "Operating system not currently supported."
+#endif
+
+struct THostCacheEntry{
+	char HostName[100];
+	bool Resolved;
+	int IPAddress;
+	int ResolveTime;
+};
+
+static THostCacheEntry *g_CachedHostNames;
+
+bool InitHostCache(void){
+	ASSERT(g_CachedHostNames == NULL);
+	LOG("Max cached host names: %d", g_MaxCachedHostNames);
+	LOG("Host name expire time: %dms", g_HostNameExpireTime);
+	g_CachedHostNames = (THostCacheEntry*)calloc(
+			g_MaxCachedHostNames, sizeof(THostCacheEntry));
+	return true;
+}
+
+void ExitHostCache(void){
+	if(g_CachedHostNames != NULL){
+		free(g_CachedHostNames);
+		g_CachedHostNames = NULL;
+	}
+}
+
+static bool DoResolveHostName(const char *HostName, int *OutAddr){
+	ASSERT(HostName != NULL && OutAddr != NULL);
+	addrinfo *Result = NULL;
+	addrinfo Hints = {};
+	Hints.ai_family = AF_INET;
+	Hints.ai_socktype = SOCK_STREAM;
+	int ErrCode = getaddrinfo(HostName, NULL, &Hints, &Result);
+	if(ErrCode != 0){
+		LOG_ERR("Failed to resolve hostname \"%s\": %s", HostName, gai_strerror(ErrCode));
+		return false;
+	}
+
+	bool Resolved = false;
+	for(addrinfo *AddrInfo = Result;
+			AddrInfo != NULL;
+			AddrInfo = AddrInfo->ai_next){
+		if(AddrInfo->ai_family == AF_INET && AddrInfo->ai_socktype == SOCK_STREAM){
+			ASSERT(AddrInfo->ai_addrlen == sizeof(sockaddr_in));
+			*OutAddr = ntohl(((sockaddr_in*)AddrInfo->ai_addr)->sin_addr.s_addr);
+			Resolved = true;
+			break;
+		}
+	}
+	freeaddrinfo(Result);
+	return Resolved;
+}
+
+bool ResolveHostName(const char *HostName, int *OutAddr){
+	ASSERT(HostName != NULL && !StringEmpty(HostName));
+	THostCacheEntry *Entry = NULL;
+	int LeastRecentlyUsedIndex = 0;
+	int LeastRecentlyUsedTime = g_CachedHostNames[0].ResolveTime;
+	for(int i = 0; i < g_MaxCachedHostNames; i += 1){
+		THostCacheEntry *Current = &g_CachedHostNames[i];
+
+		if((g_MonotonicTimeMS - Current->ResolveTime) >= g_HostNameExpireTime){
+			memset(Current, 0, sizeof(THostCacheEntry));
+		}
+
+		if(Current->ResolveTime < LeastRecentlyUsedTime){
+			LeastRecentlyUsedIndex = i;
+			LeastRecentlyUsedTime = Current->ResolveTime;
+		}
+
+		if(StringEq(HostName, Current->HostName)){
+			Entry = Current;
+			break;
+		}
+	}
+
+	if(Entry == NULL){
+		// NOTE(fusion): We also cache failures.
+		Entry = &g_CachedHostNames[LeastRecentlyUsedIndex];
+		if(!StringCopy(Entry->HostName, sizeof(Entry->HostName), HostName)){
+			LOG_WARN("Hostname \"%s\" was improperly cached because it was"
+					" too long (Length: %d, MaxLength: %d)", HostName,
+					(int)strlen(HostName), (int)sizeof(Entry->HostName));
+		}
+		Entry->Resolved = DoResolveHostName(HostName, &Entry->IPAddress);
+		Entry->ResolveTime = g_MonotonicTimeMS;
+	}
+
+	if(Entry && Entry->Resolved){
+		if(OutAddr){
+			*OutAddr = Entry->IPAddress;
+		}
+		return true;
+	}else{
+		return false;
+	}
+}
diff --git a/src/querymanager.cc b/src/querymanager.cc
index 1ed818e..6f4cfc9 100644
--- a/src/querymanager.cc
+++ b/src/querymanager.cc
@@ -15,14 +15,20 @@ int  g_ShutdownSignal			= 0;
 // Time
 int  g_MonotonicTimeMS			= 0;
 
-// Config
+// Database Config
 char g_DatabaseFile[1024]		= "tibia.db";
 int  g_MaxCachedStatements		= 100;
+
+// HostCache Config
+int  g_MaxCachedHostNames		= 100;
+int  g_HostNameExpireTime       = 30 * 60 * 1000; // milliseconds
+
+// Connection Config
 int  g_UpdateRate				= 20;
 int  g_QueryManagerPort			= 7174;
 char g_QueryManagerPassword[30]	= "";
 int  g_MaxConnections			= 50;
-int  g_MaxConnectionIdleTime	= 60000;
+int  g_MaxConnectionIdleTime	= 60 * 1000; // milliseconds
 int  g_MaxConnectionPacketSize	= (int)MB(1);
 
 void LogAdd(const char *Prefix, const char *Format, ...){
@@ -370,6 +376,10 @@ bool ReadConfig(const char *FileName){
 			ReadStringConfig(g_DatabaseFile, (int)sizeof(g_DatabaseFile), Val);
 		}else if(StringEqCI(Key, "MaxCachedStatements")){
 			ReadIntegerConfig(&g_MaxCachedStatements, Val);
+		}else if(StringEqCI(Key, "MaxCachedHostNames")){
+			ReadIntegerConfig(&g_MaxCachedHostNames, Val);
+		}else if(StringEqCI(Key, "HostNameExpireTime")){
+			ReadDurationConfig(&g_HostNameExpireTime, Val);
 		}else if(StringEqCI(Key, "UpdateRate")){
 			ReadIntegerConfig(&g_UpdateRate, Val);
 		}else if(StringEqCI(Key, "QueryManagerPort")){
@@ -430,9 +440,12 @@ int main(int argc, const char **argv){
 		return EXIT_FAILURE;
 	}
 
+	atexit(ExitHostCache);
 	atexit(ExitDatabase);
 	atexit(ExitConnections);
-	if(!InitDatabase() || !InitConnections()){
+	if(!InitHostCache()
+			|| !InitDatabase()
+			|| !InitConnections()){
 		return EXIT_FAILURE;
 	}
 
diff --git a/src/querymanager.hh b/src/querymanager.hh
index 04f74e9..c1e48eb 100644
--- a/src/querymanager.hh
+++ b/src/querymanager.hh
@@ -78,9 +78,15 @@ typedef size_t usize;
 // Time
 extern int  g_MonotonicTimeMS;
 
-// Config
+// Database Config
 extern char g_DatabaseFile[1024];
 extern int  g_MaxCachedStatements;
+
+// HostCache Config
+extern int  g_MaxCachedHostNames;
+extern int  g_HostNameExpireTime;
+
+// Connection Config
 extern int  g_UpdateRate;
 extern int  g_QueryManagerPort;
 extern char g_QueryManagerPassword[30];
@@ -934,6 +940,12 @@ bool CheckDatabaseSchema(void);
 bool InitDatabase(void);
 void ExitDatabase(void);
 
+// hostcache.cc
+//==============================================================================
+bool InitHostCache(void);
+void ExitHostCache(void);
+bool ResolveHostName(const char *HostName, int *OutAddr);
+
 // sha256.cc
 //==============================================================================
 void SHA256(const uint8 *Input, int InputBytes, uint8 *Digest);