diff --git a/include/nsysnet/socket.h b/include/nsysnet/socket.h
index e19c2e3..c37e375 100644
--- a/include/nsysnet/socket.h
+++ b/include/nsysnet/socket.h
@@ -8,7 +8,7 @@
  * @{
  */
 
-#define SOL_SOCKET      0xFFFF
+#define SOL_SOCKET      -1
 
 #define INADDR_ANY      0
 
@@ -20,6 +20,9 @@
 #define AF_INET         PF_INET
 #define AF_INET6        PF_INET6
 
+#define EAGAIN          6
+#define EWOULDBLOCK     6
+
 #define SOCK_STREAM     1
 #define SOCK_DGRAM      2
 
@@ -51,6 +54,9 @@
 #define SO_RCVLOWAT     0x1004      // receive low-water mark
 #define SO_TYPE         0x1008      // get socket type
 #define SO_ERROR        0x1009      // get socket error
+#define SO_NBIO         0x1014      // set socket to NON-blocking mode
+#define SO_BIO          0x1015      // set socket to blocking mode
+#define SO_NONBLOCK     0x1016      // set/get blocking mode via optval param
 
 #define FD_SETSIZE (32)
 #define FD_CLR(n, set) \
@@ -101,6 +107,12 @@ struct sockaddr_in
    char sin_zero[8];
 };
 
+struct timeval
+{
+   long tv_sec;
+   long tv_usec;
+};
+
 struct fd_set
 {
    fd_mask fd_bits;
@@ -113,6 +125,9 @@ extern "C" {
 void
 socket_lib_init();
 
+void
+socket_lib_finish();
+
 int
 accept(int sockfd,
        struct sockaddr *addr,
@@ -203,12 +218,27 @@ select(int nfds,
        fd_set *exceptfds,
        struct timeval *timeout);
 
-char *
+const char *
 inet_ntoa(struct in_addr in);
 
 int
 inet_aton(const char *cp, struct in_addr *inp);
 
+int
+socketlasterr();
+
+uint32_t
+htonl(uint32_t val);
+
+uint16_t
+htons(uint16_t val);
+
+uint32_t
+ntohl(uint32_t val);
+
+uint16_t
+ntohs(uint16_t val);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/rpl/nsysnet/exports.h b/rpl/nsysnet/exports.h
index 6b722f4..f4c7fcc 100644
--- a/rpl/nsysnet/exports.h
+++ b/rpl/nsysnet/exports.h
@@ -1,5 +1,6 @@
 // nsysnet/socket.h
 EXPORT(socket_lib_init);
+EXPORT(socket_lib_finish);
 EXPORT(socket);
 EXPORT(socketclose);
 EXPORT(connect);
@@ -31,3 +32,4 @@ EXPORT(ntohl);
 EXPORT(htonl);
 EXPORT(ntohs);
 EXPORT(htons);
+EXPORT(socketlasterr);