Added support to UDP socket options.

src/luasocket.c

@@ -159,7 +159,7 @@ static int global_tohostname(lua_State *L);
 static int global_udpsocket(lua_State *L);
 
 #ifndef LUASOCKET_NOGLOBALS
-static int global_calltable(lua_State *L);
+static int global_callfromtable(lua_State *L);
 #endif
 
 /* luasocket table method API functions */
@@ -219,6 +219,7 @@ static const char *udp_setpeername(p_sock sock, const char *address,
     unsigned short port);
 static const char *udp_setsockname(p_sock sock, const char *address, 
     unsigned short port);
+static int set_option(lua_State *L, p_sock sock);
 static void set_reuseaddr(p_sock sock);
 static void set_blocking(p_sock sock);
 static void set_nonblocking(p_sock sock);
@@ -305,8 +306,6 @@ static int global_tcpconnect(lua_State *L)
 
 /*-------------------------------------------------------------------------*\
 * Creates a udp socket object and returns it to the Lua script. 
-* The timeout values are initialized as -1 so that the socket will block 
-* at any IO operation.
 * Lua Returns
 *   On success: udp socket
 *   On error: nil, followed by an error message
@@ -314,8 +313,16 @@ static int global_tcpconnect(lua_State *L)
 static int global_udpsocket(lua_State *L)
 {
     p_tags tags = pop_tags(L);
+	int top = lua_gettop(L);
     p_sock sock = push_udptable(L, tags);
     if (!sock) return 2;
+	if (top >= 1 && lua_istable(L, 1)) {
+		lua_pushnil(L);
+		while (lua_next(L, 1)) {
+			if (!set_option(L, sock)) lua_error(L, "invalid socket option");
+			lua_pop(L, 1);
+		}
+	}
     return 1;
 }
 
@@ -542,7 +549,7 @@ static int table_udpsendto(lua_State *L)
 * Global function that calls corresponding table method.
 \*-------------------------------------------------------------------------*/
 #ifndef LUASOCKET_NOGLOBALS
-int global_calltable(lua_State *L)
+int global_callfromtable(lua_State *L)
 {
     p_tags tags = pop_tags(L);
     if (lua_tag(L, 1) != tags->table) lua_error(L, "invalid socket object");
@@ -1049,6 +1056,61 @@ void set_reuseaddr(p_sock sock)
     setsockopt(sock->sock, SOL_SOCKET, SO_REUSEADDR, (char *)&val, sizeof(val));
 }
 
+/*-------------------------------------------------------------------------*\
+* Set socket options from a table on top of Lua stack.
+* Supports SO_KEEPALIVE, SO_DONTROUTE, SO_BROADCAST, and SO_LINGER options.
+* Input
+*   L: Lua state to use
+*   sock: socket to set option
+* Returns
+*   1 if successful, 0 otherwise
+\*-------------------------------------------------------------------------*/
+static int set_option(lua_State *L, p_sock sock)
+{
+	static const char *const optionnames[] = {
+		"SO_KEEPALIVE", "SO_DONTROUTE", "SO_BROADCAST", "SO_LINGER", NULL
+	};
+	const char *option = lua_tostring(L, -2);
+	int err;
+	switch (luaL_findstring(option, optionnames)) {
+		case 0: {
+			int bool = (int) lua_tonumber(L, -1);
+			err = setsockopt(sock->sock, SOL_SOCKET, SO_KEEPALIVE, &bool, 
+				sizeof(bool));
+			return err >= 0;
+		}
+		case 1: {
+			int bool = (int) lua_tonumber(L, -1);
+			err = setsockopt(sock->sock, SOL_SOCKET, SO_DONTROUTE, &bool, 
+				sizeof(bool));
+			return err >= 0;
+		}
+		case 2: {
+			int bool = (int) lua_tonumber(L, -1);
+			err = setsockopt(sock->sock, SOL_SOCKET, SO_BROADCAST, &bool,
+				sizeof(bool));
+			return err >= 0;
+		}
+		case 3: {
+			struct linger linger;
+			if (!lua_istable(L, -1)) return 0;
+			lua_pushstring(L, "l_onoff");
+			lua_gettable(L, -2);
+			linger.l_onoff = lua_tonumber(L, -1);
+			lua_pop(L, 1);
+			lua_pushstring(L, "l_linger");
+			lua_gettable(L, -2);
+			linger.l_linger = lua_tonumber(L, -1);
+			lua_pop(L, 1);
+			err = setsockopt(sock->sock, SOL_SOCKET, SO_LINGER, &linger, 
+				sizeof(linger));
+			return err >= 0;
+		}
+		default: return 0;
+	}
+}
+
+
 /*-------------------------------------------------------------------------*\
 * Tries to create a TCP socket and bind it to (address, port)
 * Input
@@ -1630,7 +1692,7 @@ void lua_socketlibopen(lua_State *L)
         for (i = 0; i < sizeof(global)/sizeof(char *); i++) {
             lua_pushstring(L, global[i]);
             lua_pushuserdata(L, tags);
-			lua_pushcclosure(L, global_calltable, 2);
+            lua_pushcclosure(L, global_callfromtable, 2);
             lua_setglobal(L, global[i]);
         }
     }