diff --git a/packages/net/lwip_tcpip/current/src/netif/slipif.c b/packages/net/lwip_tcpip/current/src/netif/slipif.c
index 6cb2db4..04a121f 100644
--- a/packages/net/lwip_tcpip/current/src/netif/slipif.c
+++ b/packages/net/lwip_tcpip/current/src/netif/slipif.c
@@ -6,38 +6,38 @@
 
 /*
  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
- * All rights reserved. 
+ * All rights reserved.
  *
- * Redistribution and use in source and binary forms, with or without 
- * modification, are permitted provided that the following conditions 
- * are met: 
- * 1. Redistributions of source code must retain the above copyright 
- *    notice, this list of conditions and the following disclaimer. 
- * 2. Redistributions in binary form must reproduce the above copyright 
- *    notice, this list of conditions and the following disclaimer in the 
- *    documentation and/or other materials provided with the distribution. 
- * 3. Neither the name of the Institute nor the names of its contributors 
- *    may be used to endorse or promote products derived from this software 
- *    without specific prior written permission. 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
- * SUCH DAMAGE. 
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
  *
  * This file is built upon the file: src/arch/rtxc/netif/sioslip.c
  *
- * Author: Magnus Ivarsson <magnus.ivarsson(at)volvo.com> 
+ * Author: Magnus Ivarsson <magnus.ivarsson(at)volvo.com>
  */
 
-/* 
+/*
  * This is an arch independent SLIP netif. The specific serial hooks must be
  * provided by another file. They are sio_open, sio_recv and sio_send
  */
@@ -61,6 +61,19 @@
 
 #define MAX_SIZE     1500
 
+enum slipif_recv_state {
+    NORMAL,
+    ESCAPE,
+};
+
+struct slipif_priv {
+  sio_fd_t sd;
+  /* q is the whole pbuf chain for a packet, p is the current pbuf in the chain */
+  struct pbuf *p, *q;
+  enum slipif_recv_state state;
+  u16_t i, recved;
+};
+
 /**
  * Send a pbuf doing the necessary SLIP encapsulation
  *
@@ -74,6 +87,7 @@
 err_t
 slipif_output(struct netif *netif, struct pbuf *p, struct ip_addr *ipaddr)
 {
+  struct slipif_priv *priv;
   struct pbuf *q;
   u16_t i;
   u8_t c;
@@ -84,28 +98,30 @@ slipif_output(struct netif *netif, struct pbuf *p, struct ip_addr *ipaddr)
 
   LWIP_UNUSED_ARG(ipaddr);
 
+  priv = netif->state;
+
   /* Send pbuf out on the serial I/O device. */
-  sio_send(SLIP_END, netif->state);
+  sio_send(SLIP_END, priv->sd);
 
   for (q = p; q != NULL; q = q->next) {
     for (i = 0; i < q->len; i++) {
       c = ((u8_t *)q->payload)[i];
       switch (c) {
       case SLIP_END:
-        sio_send(SLIP_ESC, netif->state);
-        sio_send(SLIP_ESC_END, netif->state);
+        sio_send(SLIP_ESC, priv->sd);
+        sio_send(SLIP_ESC_END, priv->sd);
         break;
       case SLIP_ESC:
-        sio_send(SLIP_ESC, netif->state);
-        sio_send(SLIP_ESC_ESC, netif->state);
+        sio_send(SLIP_ESC, priv->sd);
+        sio_send(SLIP_ESC_ESC, priv->sd);
         break;
       default:
-        sio_send(c, netif->state);
+        sio_send(c, priv->sd);
         break;
       }
     }
   }
-  sio_send(SLIP_END, netif->state);
+  sio_send(SLIP_END, priv->sd);
   return ERR_OK;
 }
 
@@ -115,42 +131,45 @@ slipif_output(struct netif *netif, struct pbuf *p, struct ip_addr *ipaddr)
  * Poll the serial layer by calling sio_recv()
  *
  * @param netif the lwip network interface structure for this slipif
- * @return The IP packet when SLIP_END is received 
+ * @return The IP packet when SLIP_END is received
  */
 static struct pbuf *
 slipif_input(struct netif *netif)
 {
+  struct slipif_priv *priv;
   u8_t c;
-  /* q is the whole pbuf chain for a packet, p is the current pbuf in the chain */
-  struct pbuf *p, *q;
-  u16_t recved;
-  u16_t i;
+  struct pbuf *t;
 
   LWIP_ASSERT("netif != NULL", (netif != NULL));
   LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
 
-  q = p = NULL;
-  recved = i = 0;
-  c = 0;
+  priv = netif->state;
 
-  while (1) {
-    c = sio_recv(netif->state);
-    switch (c) {
-    case SLIP_END:
-      if (recved > 0) {
-        /* Received whole packet. */
-        /* Trim the pbuf to the size of the received packet. */
-        pbuf_realloc(q, recved);
-        
-        LINK_STATS_INC(link.recv);
-        
-        LWIP_DEBUGF(SLIP_DEBUG, ("slipif: Got packet\n"));
-        return q;
+  while (sio_read(priv->sd, &c, 1) > 0) {
+    switch (priv->state) {
+    case NORMAL:
+      switch (c) {
+      case SLIP_END:
+        if (priv->recved > 0) {
+          /* Received whole packet. */
+          /* Trim the pbuf to the size of the received packet. */
+          pbuf_realloc(priv->q, priv->recved);
+
+          LINK_STATS_INC(link.recv);
+
+          LWIP_DEBUGF(SLIP_DEBUG, ("slipif: Got packet\n"));
+          t = priv->q;
+          priv->p = priv->q = NULL;
+          priv->i = priv->recved = 0;
+          return t;
+        }
+        continue;
+      case SLIP_ESC:
+        priv->state = ESCAPE;
+        continue;
       }
       break;
-
-    case SLIP_ESC:
-      c = sio_recv(netif->state);
+    case ESCAPE:
       switch (c) {
       case SLIP_ESC_END:
         c = SLIP_END;
@@ -159,52 +178,52 @@ slipif_input(struct netif *netif)
         c = SLIP_ESC;
         break;
       }
+      priv->state = NORMAL;
       /* FALLTHROUGH */
+    }
 
-    default:
-      /* byte received, packet not yet completely received */
-      if (p == NULL) {
-        /* allocate a new pbuf */
-        LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: alloc\n"));
-        p = pbuf_alloc(PBUF_LINK, PBUF_POOL_BUFSIZE, PBUF_POOL);
-
-        if (p == NULL) {
-          LINK_STATS_INC(link.drop);
-          LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: no new pbuf! (DROP)\n"));
-          /* don't process any further since we got no pbuf to receive to */
-          break;
-        }
+    /* byte received, packet not yet completely received */
+    if (priv->p == NULL) {
+      /* allocate a new pbuf */
+      LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: alloc\n"));
+      priv->p = pbuf_alloc(PBUF_LINK, PBUF_POOL_BUFSIZE, PBUF_POOL);
 
-        if (q != NULL) {
-          /* 'chain' the pbuf to the existing chain */
-          pbuf_cat(q, p);
-        } else {
-          /* p is the first pbuf in the chain */
-          q = p;
-        }
+      if (priv->p == NULL) {
+        LINK_STATS_INC(link.drop);
+        LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: no new pbuf! (DROP)\n"));
+        /* don't process any further since we got no pbuf to receive to */
+        break;
+      }
+
+      if (priv->q != NULL) {
+        /* 'chain' the pbuf to the existing chain */
+        pbuf_cat(priv->q, priv->p);
+      } else {
+        /* p is the first pbuf in the chain */
+        priv->q = priv->p;
       }
+    }
 
-      /* this automatically drops bytes if > MAX_SIZE */
-      if ((p != NULL) && (recved <= MAX_SIZE)) {
-        ((u8_t *)p->payload)[i] = c;
-        recved++;
-        i++;
-        if (i >= p->len) {
-          /* on to the next pbuf */
-          i = 0;
-          if (p->next != NULL && p->next->len > 0) {
-            /* p is a chain, on to the next in the chain */
-            p = p->next;
-          } else {
-            /* p is a single pbuf, set it to NULL so next time a new
-             * pbuf is allocated */
-            p = NULL;
-          }
+    /* this automatically drops bytes if > MAX_SIZE */
+    if ((priv->p != NULL) && (priv->recved <= MAX_SIZE)) {
+      ((u8_t *)priv->p->payload)[priv->i] = c;
+      priv->recved++;
+      priv->i++;
+      if (priv->i >= priv->p->len) {
+        /* on to the next pbuf */
+        priv->i = 0;
+        if (priv->p->next != NULL && priv->p->next->len > 0) {
+          /* p is a chain, on to the next in the chain */
+            priv->p = priv->p->next;
+        } else {
+          /* p is a single pbuf, set it to NULL so next time a new
+           * pbuf is allocated */
+            priv->p = NULL;
         }
       }
-      break;
     }
   }
+
   return NULL;
 }
 
@@ -242,6 +261,7 @@ slipif_loop(void *nf)
  *
  * @param netif the lwip network interface structure for this slipif
  * @return ERR_OK if serial line could be opened,
+ *         ERR_MEM if no memory could be allocated,
  *         ERR_IF is serial line couldn't be opened
  *
  * @note netif->num must contain the number of the serial port to open
@@ -250,22 +270,36 @@ slipif_loop(void *nf)
 err_t
 slipif_init(struct netif *netif)
 {
+  struct slipif_priv *priv;
 
   LWIP_DEBUGF(SLIP_DEBUG, ("slipif_init: netif->num=%"U16_F"\n", (u16_t)netif->num));
 
+  /* Allocate private data */
+  priv = mem_malloc(sizeof(struct slipif_priv));
+  if (!priv)
+    return ERR_MEM;
+
   netif->name[0] = 's';
   netif->name[1] = 'l';
   netif->output = slipif_output;
   netif->mtu = MAX_SIZE;
-  netif->flags = NETIF_FLAG_POINTTOPOINT;
+  netif->flags |= NETIF_FLAG_POINTTOPOINT;
 
   /* Try to open the serial port (netif->num contains the port number). */
-  netif->state = sio_open(netif->num);
-  if (!netif->state) {
+  priv->sd = sio_open(netif->num);
+  if (!priv->sd) {
     /* Opening the serial port failed. */
+    mem_free(priv);
     return ERR_IF;
   }
 
+  /* Reset the state. */
+  priv->p = priv->q = NULL;
+  priv->state = NORMAL;
+  priv->i = priv->recved = 0;
+
+  netif->state = priv;
+
   /* initialize the snmp variables and counters inside the struct netif
    * ifSpeed: no assumption can be made without knowing more about the
    * serial line!
@@ -276,4 +310,28 @@ slipif_init(struct netif *netif)
   sys_thread_new(SLIPIF_THREAD_NAME, slipif_loop, netif, SLIPIF_THREAD_STACKSIZE, SLIPIF_THREAD_PRIO);
   return ERR_OK;
 }
+
+/**
+ * Polls the serial device and feeds the IP layer with incoming packets.
+ *
+ * @param netif The lwip network interface structure for this slipif
+ */
+void
+slipif_poll(struct netif *netif)
+{
+  struct pbuf *p;
+  struct slipif_priv *priv;
+
+  LWIP_ASSERT("netif != NULL", (netif != NULL));
+  LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
+
+  priv = netif->state;
+
+  while ((p = slipif_input(netif))) {
+    if (netif->input(p, netif) != ERR_OK) {
+      pbuf_free(p);
+    }
+  }
+}
+
 #endif /* LWIP_HAVE_SLIPIF */
