3 files changed, 31 insertions, 34 deletions

diff --git a/src/select.c b/src/select.c
index d14c40a..9d133b7 100644
--- a/src/select.c
+++ b/src/select.c
@@ -39,7 +39,10 @@ static luaL_Reg func[] = {
 \*-------------------------------------------------------------------------*/
 int select_open(lua_State *L) {
     lua_pushstring(L, "_SETSIZE");
-    lua_pushnumber(L, FD_SETSIZE);
+    lua_pushinteger(L, FD_SETSIZE);
+    lua_rawset(L, -3);
+    lua_pushstring(L, "_SOCKETINVALID");
+    lua_pushinteger(L, SOCKET_INVALID);
     lua_rawset(L, -3);
     luaL_setfuncs(L, func, 0);
     return 0;
diff --git a/src/udp.c b/src/udp.c
index 9c27b60..968dca8 100644
--- a/src/udp.c
+++ b/src/udp.c
@@ -41,7 +41,6 @@ static int meth_setpeername(lua_State *L);
 static int meth_close(lua_State *L);
 static int meth_setoption(lua_State *L);
 static int meth_getoption(lua_State *L);
-static int meth_getbufferlength(lua_State *L);
 static int meth_settimeout(lua_State *L);
 static int meth_getfd(lua_State *L);
 static int meth_setfd(lua_State *L);
@@ -64,7 +63,6 @@ static luaL_Reg udp_methods[] = {
     {"setfd",       meth_setfd},
     {"setoption",   meth_setoption},
     {"getoption",   meth_getoption},
-    {"getoption",   meth_getbufferlength},
     {"setpeername", meth_setpeername},
     {"setsockname", meth_setsockname},
     {"settimeout",  meth_settimeout},
@@ -118,8 +116,7 @@ static luaL_Reg func[] = {
 /*-------------------------------------------------------------------------*\
 * Initializes module
 \*-------------------------------------------------------------------------*/
-int udp_open(lua_State *L)
-{
+int udp_open(lua_State *L) {
     /* create classes */
     auxiliar_newclass(L, "udp{connected}", udp_methods);
     auxiliar_newclass(L, "udp{unconnected}", udp_methods);
@@ -130,6 +127,10 @@ int udp_open(lua_State *L)
     auxiliar_add2group(L, "udp{unconnected}", "select{able}");
     /* define library functions */
     luaL_setfuncs(L, func, 0);
+    /* export default UDP size */
+    lua_pushliteral(L, "_DATAGRAMSIZE");
+    lua_pushinteger(L, UDP_DATAGRAMSIZE);
+    lua_rawset(L, -3);
     return 0;
 }
 
@@ -205,30 +206,26 @@ static int meth_sendto(lua_State *L) {
 static int meth_receive(lua_State *L) {
     p_udp udp = (p_udp) auxiliar_checkgroup(L, "udp{any}", 1);
     char buf[UDP_DATAGRAMSIZE];
-    size_t len = MAX(udp->len, UDP_DATAGRAMSIZE);
-    char *dgram = len > sizeof(buf)? udp->buf: buf;
-    size_t got, wanted = (size_t) luaL_optnumber(L, 2, len);
+    size_t got, wanted = (size_t) luaL_optnumber(L, 2, sizeof(buf));
+    char *dgram = wanted > sizeof(buf)? (char *) malloc(wanted): buf;
     int err;
     p_timeout tm = &udp->tm;
     timeout_markstart(tm);
-    wanted = MIN(wanted, len);
+    if (!dgram) {
+        lua_pushnil(L);
+        lua_pushliteral(L, "out of memory");
+        return 2;
+    }
     err = socket_recv(&udp->sock, dgram, wanted, &got, tm);
     /* Unlike TCP, recv() of zero is not closed, but a zero-length packet. */
-    if (err != IO_DONE && err != IO_CLOSED ) {
+    if (err != IO_DONE && err != IO_CLOSED) {
         lua_pushnil(L);
         lua_pushstring(L, udp_strerror(err));
+        if (wanted > sizeof(buf)) free(dgram);
         return 2;
     }
     lua_pushlstring(L, dgram, got);
-    return 1;
-}
-
-/*-------------------------------------------------------------------------*\
-* Receives data from a UDP socket
-\*-------------------------------------------------------------------------*/
-static int meth_getbufferlength(lua_State *L) {
-    p_udp udp = (p_udp) auxiliar_checkgroup(L, "udp{any}", 1);
-    lua_pushinteger(L, MAX(UDP_DATAGRAMSIZE, udp->len));
+    if (wanted > sizeof(buf)) free(dgram);
     return 1;
 }
 
@@ -238,9 +235,8 @@ static int meth_getbufferlength(lua_State *L) {
 static int meth_receivefrom(lua_State *L) {
     p_udp udp = (p_udp) auxiliar_checkclass(L, "udp{unconnected}", 1);
     char buf[UDP_DATAGRAMSIZE];
-    size_t len = MAX(udp->len, UDP_DATAGRAMSIZE);
-    char *dgram = len > sizeof(buf)? udp->buf: buf;
-    size_t got, wanted = (size_t) luaL_optnumber(L, 2, len);
+    size_t got, wanted = (size_t) luaL_optnumber(L, 2, sizeof(buf));
+    char *dgram = wanted > sizeof(buf)? (char *) malloc(wanted): buf;
     struct sockaddr_storage addr;
     socklen_t addr_len = sizeof(addr);
     char addrstr[INET6_ADDRSTRLEN];
@@ -248,13 +244,18 @@ static int meth_receivefrom(lua_State *L) {
     int err;
     p_timeout tm = &udp->tm;
     timeout_markstart(tm);
-    wanted = MIN(wanted, len);
+    if (!dgram) {
+        lua_pushnil(L);
+        lua_pushliteral(L, "out of memory");
+        return 2;
+    }
     err = socket_recvfrom(&udp->sock, dgram, wanted, &got, (SA *) &addr,
             &addr_len, tm);
     /* Unlike TCP, recv() of zero is not closed, but a zero-length packet. */
     if (err != IO_DONE && err != IO_CLOSED) {
         lua_pushnil(L);
         lua_pushstring(L, udp_strerror(err));
+        if (wanted > sizeof(buf)) free(dgram);
         return 2;
     }
     err = getnameinfo((struct sockaddr *)&addr, addr_len, addrstr,
@@ -262,19 +263,20 @@ static int meth_receivefrom(lua_State *L) {
         if (err) {
         lua_pushnil(L);
         lua_pushstring(L, gai_strerror(err));
+        if (wanted > sizeof(buf)) free(dgram);
         return 2;
     }
     lua_pushlstring(L, dgram, got);
     lua_pushstring(L, addrstr);
     lua_pushinteger(L, (int) strtol(portstr, (char **) NULL, 10));
+    if (wanted > sizeof(buf)) free(dgram);
     return 3;
 }
 
 /*-------------------------------------------------------------------------*\
 * Returns family as string
 \*-------------------------------------------------------------------------*/
-static int meth_getfamily(lua_State *L)
-{
+static int meth_getfamily(lua_State *L) {
     p_udp udp = (p_udp) auxiliar_checkgroup(L, "udp{any}", 1);
     if (udp->family == AF_INET6) {
         lua_pushliteral(L, "inet6");
@@ -419,19 +421,13 @@ static int meth_setsockname(lua_State *L) {
 * Creates a master udp object
 \*-------------------------------------------------------------------------*/
 static int udp_create(lua_State *L, int family) {
-    p_udp udp = NULL;
-    /* optional length for private datagram buffer. this is useful when
-     * you need larger datagrams than UDP_DATAGRAMSIZE */
-    size_t len = (size_t) luaL_optinteger(L, 1, 0);
-    if (len <= UDP_DATAGRAMSIZE) len = 0;
     /* allocate udp object */
-    udp = (p_udp) lua_newuserdata(L, sizeof(t_udp) + len - 1);
+    p_udp udp = (p_udp) lua_newuserdata(L, sizeof(t_udp));
     auxiliar_setclass(L, "udp{unconnected}", -1);
     /* if family is AF_UNSPEC, we leave the socket invalid and
      * store AF_UNSPEC into family. This will allow it to later be
      * replaced with an AF_INET6 or AF_INET socket upon first use. */
     udp->sock = SOCKET_INVALID;
-    udp->len = len;
     timeout_init(&udp->tm, -1, -1);
     udp->family = family;
     if (family != AF_UNSPEC) {
diff --git a/src/udp.h b/src/udp.h
index da27a7a..be9b6a5 100644
--- a/src/udp.h
+++ b/src/udp.h
@@ -23,8 +23,6 @@ typedef struct t_udp_ {
     t_socket sock;
     t_timeout tm;
     int family;
-    size_t len; /* length of datagram buffer below */
-    char buf[1]; /* allocate larger structure to hold actual buffer */
 } t_udp;
 typedef t_udp *p_udp;