diff --git a/CHANGELOG b/CHANGELOG
index 73bb33b3..06c7dc49 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -23,6 +23,11 @@ HISTORY
 
   ++ New features:
 
+  2007-04-06 Frédéric Bernon, Simon Goldschmidt
+  * opt.h, tcpip.h, tcpip.c, netifapi.h, netifapi.c: New configuration option LWIP_NETIF_API
+    allow to use thread-safe functions to add/remove netif in list, and to start/stop dhcp
+    clients, using new functions from netifapi.h. Disable as default (no port change to do).
+
   2007-04-05 Frédéric Bernon
   * sockets.c: remplace ENOBUFS errors on alloc_socket by ENFILE to be more BSD compliant.
 
diff --git a/src/api/netifapi.c b/src/api/netifapi.c
new file mode 100644
index 00000000..8ca3d79e
--- /dev/null
+++ b/src/api/netifapi.c
@@ -0,0 +1,118 @@
+/*
+ * 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. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 part of the lwIP TCP/IP stack.
+ * 
+ */
+
+#include "lwip/opt.h"
+#include "lwip/arch.h"
+#include "lwip/netifapi.h"
+#include "lwip/tcpip.h"
+
+#if LWIP_NETIF_API
+
+err_t
+netifapi_netif_add( struct netif *netif,
+                    struct ip_addr *ipaddr,
+                    struct ip_addr *netmask,
+                    struct ip_addr *gw,
+                    void *state,
+                    err_t (* init)(struct netif *netif),
+                    err_t (* input)(struct pbuf *p, struct netif *netif) )
+{ struct netifapi_msg msg;
+  msg.type  = NETIFAPI_MSG_NETIF_ADD;
+  msg.netif = netif;  
+  msg.msg.add.ipaddr  = ipaddr;
+  msg.msg.add.netmask = netmask;
+  msg.msg.add.gw      = gw;
+  msg.msg.add.state   = state;
+  msg.msg.add.init    = init;
+  msg.msg.add.input   = input;
+  netifapi_msg_post(&msg);
+  return msg.err;
+}
+
+err_t
+netifapi_netif_remove( struct netif *netif)
+{ struct netifapi_msg msg;
+  msg.type  = NETIFAPI_MSG_NETIF_REMOVE;
+  msg.netif = netif;  
+  netifapi_msg_post(&msg);
+  return msg.err;
+}
+
+err_t
+netifapi_dhcp_start( struct netif *netif)
+{ struct netifapi_msg msg;
+  msg.type  = NETIFAPI_MSG_DHCP_START;
+  msg.netif = netif;  
+  netifapi_msg_post(&msg);
+  return msg.err;
+}
+
+err_t
+netifapi_dhcp_stop( struct netif *netif)
+{ struct netifapi_msg msg;
+  msg.type  = NETIFAPI_MSG_DHCP_STOP;
+  msg.netif = netif;  
+  netifapi_msg_post(&msg);
+  return msg.err;
+}
+
+void
+netifapi_msg_input( struct netifapi_msg *msg)
+{ msg->err = ERR_OK;
+  switch (msg->type) {
+    case NETIFAPI_MSG_NETIF_ADD: {
+      if (!netif_add( msg->netif,
+                      msg->msg.add.ipaddr,
+                      msg->msg.add.netmask,
+                      msg->msg.add.gw,
+                      msg->msg.add.state,
+                      msg->msg.add.init,
+                      msg->msg.add.input))
+        msg->err = ERR_IF;
+      break;
+    }
+    case NETIFAPI_MSG_NETIF_REMOVE:
+      netif_remove(msg->netif);
+      break;
+#if LWIP_DHCP    
+    case NETIFAPI_MSG_DHCP_START:
+      msg->err = dhcp_start(msg->netif);
+      break;
+    case NETIFAPI_MSG_DHCP_STOP:
+      dhcp_stop(msg->netif);
+      break;
+#endif /* LWIP_DHCP */
+  }
+ sys_sem_signal(msg->sem);
+}
+
+err_t
+netifapi_msg_post( struct netifapi_msg *msg)
+{ return tcpip_netifapi(msg);
+}
+
+#endif /* LWIP_NETIF_API */
diff --git a/src/api/tcpip.c b/src/api/tcpip.c
index 1b4f1504..c349d52b 100644
--- a/src/api/tcpip.c
+++ b/src/api/tcpip.c
@@ -198,6 +198,7 @@ tcpip_thread(void *arg)
     case TCPIP_MSG_INPUT:
       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: IP packet %p\n", (void *)msg));
       ip_input(msg->msg.inp.p, msg->msg.inp.netif);
+      memp_free(MEMP_TCPIP_MSG, msg);
       break;
 #endif /* ETHARP_TCPIP_INPUT */
 
@@ -205,20 +206,25 @@ tcpip_thread(void *arg)
     case TCPIP_MSG_ETHINPUT:
       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: Ethernet packet %p\n", (void *)msg));
       ethernet_input(msg->msg.inp.p, msg->msg.inp.netif);
+      memp_free(MEMP_TCPIP_MSG, msg);
       break;
 #endif /* ETHARP_TCPIP_ETHINPUT */
 
+#if LWIP_NETIF_API
+    case TCPIP_MSG_NETIFAPI:
+      LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: Netif API message %p\n", (void *)msg));
+      netifapi_msg_input(msg->msg.netifapimsg);
+      break;
+#endif /* LWIP_NETIF_API */
+
     case TCPIP_MSG_CALLBACK:
       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: CALLBACK %p\n", (void *)msg));
       msg->msg.cb.f(msg->msg.cb.ctx);
+      memp_free(MEMP_TCPIP_MSG, msg);
       break;
     default:
       break;
     }
-    
-    if (msg->type!=TCPIP_MSG_API) {
-      memp_free(MEMP_TCPIP_MSG, msg);
-    }
   }
 }
 
@@ -303,6 +309,29 @@ tcpip_apimsg(struct api_msg *apimsg)
   return ERR_VAL;
 }
 
+#if LWIP_NETIF_API
+err_t tcpip_netifapi(struct netifapi_msg* netifapimsg)
+{
+  struct tcpip_msg msg;
+  
+  if (mbox != SYS_MBOX_NULL) {
+    netifapimsg->sem = sys_sem_new(0);      
+    if (netifapimsg->sem == SYS_SEM_NULL) {
+      netifapimsg->err = ERR_MEM;
+      return netifapimsg->err;
+    }  
+      
+    msg.type = TCPIP_MSG_NETIFAPI;
+    msg.msg.netifapimsg = netifapimsg;
+    sys_mbox_post(mbox, &msg);
+    sys_sem_wait(netifapimsg->sem);
+    sys_sem_free(netifapimsg->sem);    
+    return netifapimsg->err;
+  }
+  return ERR_VAL;
+}
+#endif /* LWIP_NETIF_API */
+
 void
 tcpip_init(void (* initfunc)(void *), void *arg)
 {
diff --git a/src/include/lwip/netifapi.h b/src/include/lwip/netifapi.h
new file mode 100644
index 00000000..dfe7b0ef
--- /dev/null
+++ b/src/include/lwip/netifapi.h
@@ -0,0 +1,87 @@
+/*
+ * 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. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 part of the lwIP TCP/IP stack.
+ * 
+ */
+ 
+#ifndef __LWIP_NETIFAPI_H__
+#define __LWIP_NETIFAPI_H__
+
+#include "lwip/opt.h"
+#include "lwip/sys.h"
+#include "lwip/netif.h"
+#include "lwip/dhcp.h"
+
+#if LWIP_NETIF_API
+
+enum netifapi_msg_type {
+  NETIFAPI_MSG_NETIF_ADD,
+  NETIFAPI_MSG_NETIF_REMOVE,
+#if LWIP_DHCP  
+  NETIFAPI_MSG_DHCP_START,
+  NETIFAPI_MSG_DHCP_STOP
+#endif /* LWIP_DHCP */
+};
+
+struct netifapi_msg {
+  enum netifapi_msg_type type;
+  sys_sem_t sem;
+  err_t err;
+  struct netif *netif;
+  union {
+    struct {
+      struct ip_addr *ipaddr;
+      struct ip_addr *netmask;
+      struct ip_addr *gw;
+      void *state;
+      err_t (* init)(struct netif *netif);
+      err_t (* input)(struct pbuf *p, struct netif *netif);
+    } add;
+  } msg;
+};
+
+
+/* API for application */
+err_t netifapi_netif_add   ( struct netif *netif,
+                             struct ip_addr *ipaddr,
+                             struct ip_addr *netmask,
+                             struct ip_addr *gw,
+                             void *state,
+                             err_t (* init)(struct netif *netif),
+                             err_t (* input)(struct pbuf *p, struct netif *netif) );
+
+err_t netifapi_netif_remove( struct netif *netif);
+
+err_t netifapi_dhcp_start  ( struct netif *netif);
+
+err_t netifapi_dhcp_stop   ( struct netif *netif);
+
+
+/* API for tcpip_thread */
+void  netifapi_msg_input(struct netifapi_msg *msg);
+err_t netifapi_msg_post (struct netifapi_msg *msg);
+
+#endif /* LWIP_NETIF_API */
+
+#endif /* __LWIP_NETIFAPI_H__ */
diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index 42d1182d..eafb72fe 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -393,6 +393,11 @@ a lot of data that needs to be copied, this should be set high. */
 #define LWIP_NETIF_HOSTNAME             0
 #endif
 
+/* Support network interface API */
+#ifndef LWIP_NETIF_API
+#define LWIP_NETIF_API                  0
+#endif
+
 /* Support network interface callbacks */
 #ifndef LWIP_NETIF_CALLBACK
 #define LWIP_NETIF_CALLBACK             0
diff --git a/src/include/lwip/tcpip.h b/src/include/lwip/tcpip.h
index f3ce388d..ed7fbea0 100644
--- a/src/include/lwip/tcpip.h
+++ b/src/include/lwip/tcpip.h
@@ -33,6 +33,7 @@
 #define __LWIP_TCPIP_H__
 
 #include "lwip/api_msg.h"
+#include "lwip/netifapi.h"
 #include "lwip/pbuf.h"
 
 void tcpip_init(void (* tcpip_init_done)(void *), void *arg);
@@ -43,10 +44,11 @@ err_t tcpip_input(struct pbuf *p, struct netif *inp);
 #if ETHARP_TCPIP_ETHINPUT
 err_t tcpip_ethinput(struct pbuf *p, struct netif *inp);
 #endif /* ETHARP_TCPIP_ETHINPUT */
+#if LWIP_NETIF_API
+err_t tcpip_netifapi(struct netifapi_msg* netifapimsg);
+#endif /* LWIP_NETIF_API */
 err_t tcpip_callback(void (*f)(void *ctx), void *ctx);
 
-void tcpip_tcp_timer_needed(void);
-
 enum tcpip_msg_type {
   TCPIP_MSG_API,
 #if ETHARP_TCPIP_INPUT  
@@ -55,6 +57,9 @@ enum tcpip_msg_type {
 #if ETHARP_TCPIP_ETHINPUT
   TCPIP_MSG_ETHINPUT,
 #endif /* ETHARP_TCPIP_ETHINPUT */
+#if LWIP_NETIF_API
+  TCPIP_MSG_NETIFAPI,
+#endif /* LWIP_NETIF_API */
   TCPIP_MSG_CALLBACK
 };
 
@@ -63,6 +68,9 @@ struct tcpip_msg {
   sys_sem_t *sem;
   union {
     struct api_msg *apimsg;
+#if LWIP_NETIF_API
+    struct netifapi_msg *netifapimsg;
+#endif /* LWIP_NETIF_API */
     struct {
       struct pbuf *p;
       struct netif *netif;