initial commit of lk (little kernel) project
diff --git a/lib/lwip/src/api/api_msg.c b/lib/lwip/src/api/api_msg.c
new file mode 100644
index 0000000..0cbe626
--- /dev/null
+++ b/lib/lwip/src/api/api_msg.c
@@ -0,0 +1,800 @@
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * 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. 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.
+ * 
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+#include "lwip/opt.h"
+#include "lwip/arch.h"
+#include "lwip/api_msg.h"
+#include "lwip/memp.h"
+#include "lwip/sys.h"
+#include "lwip/tcpip.h"
+
+#if LWIP_RAW
+static u8_t
+recv_raw(void *arg, struct raw_pcb *pcb, struct pbuf *p,
+    struct ip_addr *addr)
+{
+  struct netbuf *buf;
+  struct netconn *conn;
+
+  conn = arg;
+  if (!conn) return 0;
+
+  if (conn->recvmbox != SYS_MBOX_NULL) {
+    if (!(buf = memp_malloc(MEMP_NETBUF))) {
+      return 0;
+    }
+    pbuf_ref(p);
+    buf->p = p;
+    buf->ptr = p;
+    buf->fromaddr = addr;
+    buf->fromport = pcb->protocol;
+
+    conn->recv_avail += p->tot_len;
+    /* Register event with callback */
+    if (conn->callback)
+        (*conn->callback)(conn, NETCONN_EVT_RCVPLUS, p->tot_len);
+    sys_mbox_post(conn->recvmbox, buf);
+  }
+
+  return 0; /* do not eat the packet */
+}
+#endif
+#if LWIP_UDP
+static void
+recv_udp(void *arg, struct udp_pcb *pcb, struct pbuf *p,
+   struct ip_addr *addr, u16_t port)
+{
+  struct netbuf *buf;
+  struct netconn *conn;
+
+  conn = arg;
+  
+  if (conn == NULL) {
+    pbuf_free(p);
+    return;
+  }
+  if (conn->recvmbox != SYS_MBOX_NULL) {
+    buf = memp_malloc(MEMP_NETBUF);
+    if (buf == NULL) {
+      pbuf_free(p);
+      return;
+    } else {
+      buf->p = p;
+      buf->ptr = p;
+      buf->fromaddr = addr;
+      buf->fromport = port;
+    }
+
+  conn->recv_avail += p->tot_len;
+    /* Register event with callback */
+    if (conn->callback)
+        (*conn->callback)(conn, NETCONN_EVT_RCVPLUS, p->tot_len);
+    sys_mbox_post(conn->recvmbox, buf);
+  }
+}
+#endif /* LWIP_UDP */
+#if LWIP_TCP
+
+static err_t
+recv_tcp(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err)
+{
+  struct netconn *conn;
+  u16_t len;
+  
+  conn = arg;
+
+  if (conn == NULL) {
+    pbuf_free(p);
+    return ERR_VAL;
+  }
+
+  if (conn->recvmbox != SYS_MBOX_NULL) {
+        
+    conn->err = err;
+    if (p != NULL) {
+        len = p->tot_len;
+        conn->recv_avail += len;
+    }
+    else
+        len = 0;
+    /* Register event with callback */
+    if (conn->callback)
+        (*conn->callback)(conn, NETCONN_EVT_RCVPLUS, len);
+    sys_mbox_post(conn->recvmbox, p);
+  }  
+  return ERR_OK;
+}
+
+
+static err_t
+poll_tcp(void *arg, struct tcp_pcb *pcb)
+{
+  struct netconn *conn;
+
+  conn = arg;
+  if (conn != NULL &&
+     (conn->state == NETCONN_WRITE || conn->state == NETCONN_CLOSE) &&
+     conn->sem != SYS_SEM_NULL) {
+    sys_sem_signal(conn->sem);
+  }
+  return ERR_OK;
+}
+
+static err_t
+sent_tcp(void *arg, struct tcp_pcb *pcb, u16_t len)
+{
+  struct netconn *conn;
+
+  conn = arg;
+  if (conn != NULL && conn->sem != SYS_SEM_NULL) {
+    sys_sem_signal(conn->sem);
+  }
+
+  if (conn && conn->callback)
+      if (tcp_sndbuf(conn->pcb.tcp) > TCP_SNDLOWAT)
+          (*conn->callback)(conn, NETCONN_EVT_SENDPLUS, len);
+  
+  return ERR_OK;
+}
+
+static void
+err_tcp(void *arg, err_t err)
+{
+  struct netconn *conn;
+
+  conn = arg;
+
+  conn->pcb.tcp = NULL;
+
+  
+  conn->err = err;
+  if (conn->recvmbox != SYS_MBOX_NULL) {
+    /* Register event with callback */
+    if (conn->callback)
+      (*conn->callback)(conn, NETCONN_EVT_RCVPLUS, 0);
+    sys_mbox_post(conn->recvmbox, NULL);
+  }
+  if (conn->mbox != SYS_MBOX_NULL) {
+    sys_mbox_post(conn->mbox, NULL);
+  }
+  if (conn->acceptmbox != SYS_MBOX_NULL) {
+     /* Register event with callback */
+    if (conn->callback)
+      (*conn->callback)(conn, NETCONN_EVT_RCVPLUS, 0);
+    sys_mbox_post(conn->acceptmbox, NULL);
+  }
+  if (conn->sem != SYS_SEM_NULL) {
+    sys_sem_signal(conn->sem);
+  }
+}
+
+static void
+setup_tcp(struct netconn *conn)
+{
+  struct tcp_pcb *pcb;
+  
+  pcb = conn->pcb.tcp;
+  tcp_arg(pcb, conn);
+  tcp_recv(pcb, recv_tcp);
+  tcp_sent(pcb, sent_tcp);
+  tcp_poll(pcb, poll_tcp, 4);
+  tcp_err(pcb, err_tcp);
+}
+
+static err_t
+accept_function(void *arg, struct tcp_pcb *newpcb, err_t err)
+{
+  sys_mbox_t mbox;
+  struct netconn *newconn;
+  struct netconn *conn;
+  
+#if API_MSG_DEBUG
+#if TCP_DEBUG
+  tcp_debug_print_state(newpcb->state);
+#endif /* TCP_DEBUG */
+#endif /* API_MSG_DEBUG */
+  conn = (struct netconn *)arg;
+  mbox = conn->acceptmbox;
+  newconn = memp_malloc(MEMP_NETCONN);
+  if (newconn == NULL) {
+    return ERR_MEM;
+  }
+  newconn->type = NETCONN_TCP;
+  newconn->pcb.tcp = newpcb;
+  setup_tcp(newconn);
+  newconn->recvmbox = sys_mbox_new();
+  if (newconn->recvmbox == SYS_MBOX_NULL) {
+    memp_free(MEMP_NETCONN, newconn);
+    return ERR_MEM;
+  }
+  newconn->mbox = sys_mbox_new();
+  if (newconn->mbox == SYS_MBOX_NULL) {
+    sys_mbox_free(newconn->recvmbox);
+    memp_free(MEMP_NETCONN, newconn);
+    return ERR_MEM;
+  }
+  newconn->sem = sys_sem_new(0);
+  if (newconn->sem == SYS_SEM_NULL) {
+    sys_mbox_free(newconn->recvmbox);
+    sys_mbox_free(newconn->mbox);
+    memp_free(MEMP_NETCONN, newconn);
+    return ERR_MEM;
+  }
+  newconn->acceptmbox = SYS_MBOX_NULL;
+  newconn->err = err;
+  /* Register event with callback */
+  if (conn->callback)
+  {
+    (*conn->callback)(conn, NETCONN_EVT_RCVPLUS, 0);
+    /* We have to set the callback here even though
+     * the new socket is unknown. Mark the socket as -1. */
+    newconn->callback = conn->callback;
+    newconn->socket = -1;
+  }
+  
+  sys_mbox_post(mbox, newconn);
+  return ERR_OK;
+}
+#endif /* LWIP_TCP */
+
+static void
+do_newconn(struct api_msg_msg *msg)
+{
+   if(msg->conn->pcb.tcp != NULL) {
+   /* This "new" connection already has a PCB allocated. */
+   /* Is this an error condition? Should it be deleted? 
+      We currently just are happy and return. */
+     sys_mbox_post(msg->conn->mbox, NULL);
+     return;
+   }
+
+   msg->conn->err = ERR_OK;
+
+   /* Allocate a PCB for this connection */
+   switch(msg->conn->type) {
+#if LWIP_RAW
+   case NETCONN_RAW:
+      msg->conn->pcb.raw = raw_new(msg->msg.bc.port); /* misusing the port field */
+      raw_recv(msg->conn->pcb.raw, recv_raw, msg->conn);
+     break;
+#endif
+#if LWIP_UDP
+   case NETCONN_UDPLITE:
+      msg->conn->pcb.udp = udp_new();
+      if(msg->conn->pcb.udp == NULL) {
+         msg->conn->err = ERR_MEM;
+         break;
+      }
+      udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_UDPLITE);
+      udp_recv(msg->conn->pcb.udp, recv_udp, msg->conn);
+      break;
+   case NETCONN_UDPNOCHKSUM:
+      msg->conn->pcb.udp = udp_new();
+      if(msg->conn->pcb.udp == NULL) {
+         msg->conn->err = ERR_MEM;
+         break;
+      }
+      udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_NOCHKSUM);
+      udp_recv(msg->conn->pcb.udp, recv_udp, msg->conn);
+      break;
+   case NETCONN_UDP:
+      msg->conn->pcb.udp = udp_new();
+      if(msg->conn->pcb.udp == NULL) {
+         msg->conn->err = ERR_MEM;
+         break;
+      }
+      udp_recv(msg->conn->pcb.udp, recv_udp, msg->conn);
+      break;
+#endif /* LWIP_UDP */
+#if LWIP_TCP
+   case NETCONN_TCP:
+      msg->conn->pcb.tcp = tcp_new();
+      if(msg->conn->pcb.tcp == NULL) {
+         msg->conn->err = ERR_MEM;
+         break;
+      }
+      setup_tcp(msg->conn);
+      break;
+#endif
+   }
+   
+  
+  sys_mbox_post(msg->conn->mbox, NULL);
+}
+
+
+static void
+do_delconn(struct api_msg_msg *msg)
+{
+  if (msg->conn->pcb.tcp != NULL) {
+    switch (msg->conn->type) {
+#if LWIP_RAW
+    case NETCONN_RAW:
+      raw_remove(msg->conn->pcb.raw);
+      break;
+#endif
+#if LWIP_UDP
+    case NETCONN_UDPLITE:
+      /* FALLTHROUGH */
+    case NETCONN_UDPNOCHKSUM:
+      /* FALLTHROUGH */
+    case NETCONN_UDP:
+      msg->conn->pcb.udp->recv_arg = NULL;
+      udp_remove(msg->conn->pcb.udp);
+      break;
+#endif /* LWIP_UDP */
+#if LWIP_TCP      
+    case NETCONN_TCP:
+      if (msg->conn->pcb.tcp->state == LISTEN) {
+  tcp_arg(msg->conn->pcb.tcp, NULL);
+  tcp_accept(msg->conn->pcb.tcp, NULL);  
+  tcp_close(msg->conn->pcb.tcp);
+      } else {
+  tcp_arg(msg->conn->pcb.tcp, NULL);
+  tcp_sent(msg->conn->pcb.tcp, NULL);
+  tcp_recv(msg->conn->pcb.tcp, NULL);  
+  tcp_poll(msg->conn->pcb.tcp, NULL, 0);
+  tcp_err(msg->conn->pcb.tcp, NULL);
+  if (tcp_close(msg->conn->pcb.tcp) != ERR_OK) {
+    tcp_abort(msg->conn->pcb.tcp);
+  }
+      }
+#endif
+    default:  
+    break;
+    }
+  }
+  /* Trigger select() in socket layer */
+  if (msg->conn->callback)
+  {
+      (*msg->conn->callback)(msg->conn, NETCONN_EVT_RCVPLUS, 0);
+      (*msg->conn->callback)(msg->conn, NETCONN_EVT_SENDPLUS, 0);
+  }
+  
+  if (msg->conn->mbox != SYS_MBOX_NULL) {
+    sys_mbox_post(msg->conn->mbox, NULL);
+  }
+}
+
+static void
+do_bind(struct api_msg_msg *msg)
+{
+  if (msg->conn->pcb.tcp == NULL) {
+    switch (msg->conn->type) {
+#if LWIP_RAW
+    case NETCONN_RAW:
+      msg->conn->pcb.raw = raw_new(msg->msg.bc.port); /* misusing the port field as protocol */
+      raw_recv(msg->conn->pcb.raw, recv_raw, msg->conn);
+      break;
+#endif
+#if LWIP_UDP
+    case NETCONN_UDPLITE:
+      msg->conn->pcb.udp = udp_new();
+      udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_UDPLITE);
+      udp_recv(msg->conn->pcb.udp, recv_udp, msg->conn);
+      break;
+    case NETCONN_UDPNOCHKSUM:
+      msg->conn->pcb.udp = udp_new();
+      udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_NOCHKSUM);
+      udp_recv(msg->conn->pcb.udp, recv_udp, msg->conn);
+      break;
+    case NETCONN_UDP:
+      msg->conn->pcb.udp = udp_new();
+      udp_recv(msg->conn->pcb.udp, recv_udp, msg->conn);
+      break;
+#endif /* LWIP_UDP */
+#if LWIP_TCP      
+    case NETCONN_TCP:
+      msg->conn->pcb.tcp = tcp_new();
+      setup_tcp(msg->conn);
+#endif /* LWIP_TCP */
+    default:  
+    break;
+    }
+  }
+  switch (msg->conn->type) {
+#if LWIP_RAW
+  case NETCONN_RAW:
+    msg->conn->err = raw_bind(msg->conn->pcb.raw,msg->msg.bc.ipaddr);
+    break;
+#endif
+#if LWIP_UDP
+  case NETCONN_UDPLITE:
+    /* FALLTHROUGH */
+  case NETCONN_UDPNOCHKSUM:
+    /* FALLTHROUGH */
+  case NETCONN_UDP:
+    msg->conn->err = udp_bind(msg->conn->pcb.udp, msg->msg.bc.ipaddr, msg->msg.bc.port);
+    break;
+#endif /* LWIP_UDP */
+#if LWIP_TCP
+  case NETCONN_TCP:
+    msg->conn->err = tcp_bind(msg->conn->pcb.tcp,
+            msg->msg.bc.ipaddr, msg->msg.bc.port);
+#endif /* LWIP_TCP */
+  default:
+    break;
+  }
+  sys_mbox_post(msg->conn->mbox, NULL);
+}
+#if LWIP_TCP
+
+static err_t
+do_connected(void *arg, struct tcp_pcb *pcb, err_t err)
+{
+  struct netconn *conn;
+
+  conn = arg;
+
+  if (conn == NULL) {
+    return ERR_VAL;
+  }
+  
+  conn->err = err;
+  if (conn->type == NETCONN_TCP && err == ERR_OK) {
+    setup_tcp(conn);
+  }    
+  sys_mbox_post(conn->mbox, NULL);
+  return ERR_OK;
+}
+#endif  
+
+static void
+do_connect(struct api_msg_msg *msg)
+{
+  if (msg->conn->pcb.tcp == NULL) {
+    switch (msg->conn->type) {
+#if LWIP_RAW
+    case NETCONN_RAW:
+      msg->conn->pcb.raw = raw_new(msg->msg.bc.port); /* misusing the port field as protocol */
+      raw_recv(msg->conn->pcb.raw, recv_raw, msg->conn);
+      break;
+#endif
+#if LWIP_UDP
+    case NETCONN_UDPLITE:
+      msg->conn->pcb.udp = udp_new();
+      if (msg->conn->pcb.udp == NULL) {
+  msg->conn->err = ERR_MEM;
+  sys_mbox_post(msg->conn->mbox, NULL);
+  return;
+      }
+      udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_UDPLITE);
+      udp_recv(msg->conn->pcb.udp, recv_udp, msg->conn);
+      break;
+    case NETCONN_UDPNOCHKSUM:
+      msg->conn->pcb.udp = udp_new();
+      if (msg->conn->pcb.udp == NULL) {
+  msg->conn->err = ERR_MEM;
+  sys_mbox_post(msg->conn->mbox, NULL);
+  return;
+      }
+      udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_NOCHKSUM);
+      udp_recv(msg->conn->pcb.udp, recv_udp, msg->conn);
+      break;
+    case NETCONN_UDP:
+      msg->conn->pcb.udp = udp_new();
+      if (msg->conn->pcb.udp == NULL) {
+  msg->conn->err = ERR_MEM;
+  sys_mbox_post(msg->conn->mbox, NULL);
+  return;
+      }
+      udp_recv(msg->conn->pcb.udp, recv_udp, msg->conn);
+      break;
+#endif /* LWIP_UDP */
+#if LWIP_TCP      
+    case NETCONN_TCP:
+      msg->conn->pcb.tcp = tcp_new();      
+      if (msg->conn->pcb.tcp == NULL) {
+  msg->conn->err = ERR_MEM;
+  sys_mbox_post(msg->conn->mbox, NULL);
+  return;
+      }
+#endif
+    default:
+      break;
+    }
+  }
+  switch (msg->conn->type) {
+#if LWIP_RAW
+  case NETCONN_RAW:
+    raw_connect(msg->conn->pcb.raw, msg->msg.bc.ipaddr);
+    sys_mbox_post(msg->conn->mbox, NULL);
+    break;
+#endif
+#if LWIP_UDP
+  case NETCONN_UDPLITE:
+    /* FALLTHROUGH */
+  case NETCONN_UDPNOCHKSUM:
+    /* FALLTHROUGH */
+  case NETCONN_UDP:
+    udp_connect(msg->conn->pcb.udp, msg->msg.bc.ipaddr, msg->msg.bc.port);
+    sys_mbox_post(msg->conn->mbox, NULL);
+    break;
+#endif 
+#if LWIP_TCP      
+  case NETCONN_TCP:
+    /*    tcp_arg(msg->conn->pcb.tcp, msg->conn);*/
+    setup_tcp(msg->conn);
+    tcp_connect(msg->conn->pcb.tcp, msg->msg.bc.ipaddr, msg->msg.bc.port,
+    do_connected);
+    /*tcp_output(msg->conn->pcb.tcp);*/
+#endif
+
+  default:
+    break;
+  }
+}
+
+static void
+do_disconnect(struct api_msg_msg *msg)
+{
+
+  switch (msg->conn->type) {
+#if LWIP_RAW
+  case NETCONN_RAW:
+    /* Do nothing as connecting is only a helper for upper lwip layers */
+    break;
+#endif
+#if LWIP_UDP
+  case NETCONN_UDPLITE:
+    /* FALLTHROUGH */
+  case NETCONN_UDPNOCHKSUM:
+    /* FALLTHROUGH */
+  case NETCONN_UDP:
+    udp_disconnect(msg->conn->pcb.udp);
+    break;
+#endif 
+  case NETCONN_TCP:
+    break;
+  }
+  sys_mbox_post(msg->conn->mbox, NULL);
+}
+
+
+static void
+do_listen(struct api_msg_msg *msg)
+{
+  if (msg->conn->pcb.tcp != NULL) {
+    switch (msg->conn->type) {
+#if LWIP_RAW
+    case NETCONN_RAW:
+      LWIP_DEBUGF(API_MSG_DEBUG, ("api_msg: listen RAW: cannot listen for RAW.\n"));
+      break;
+#endif
+#if LWIP_UDP
+    case NETCONN_UDPLITE:
+      /* FALLTHROUGH */
+    case NETCONN_UDPNOCHKSUM:
+      /* FALLTHROUGH */
+    case NETCONN_UDP:
+      LWIP_DEBUGF(API_MSG_DEBUG, ("api_msg: listen UDP: cannot listen for UDP.\n"));
+      break;
+#endif /* LWIP_UDP */
+#if LWIP_TCP      
+    case NETCONN_TCP:
+      msg->conn->pcb.tcp = tcp_listen(msg->conn->pcb.tcp);
+      if (msg->conn->pcb.tcp == NULL) {
+  msg->conn->err = ERR_MEM;
+      } else {
+  if (msg->conn->acceptmbox == SYS_MBOX_NULL) {
+    msg->conn->acceptmbox = sys_mbox_new();
+    if (msg->conn->acceptmbox == SYS_MBOX_NULL) {
+      msg->conn->err = ERR_MEM;
+      break;
+    }
+  }
+  tcp_arg(msg->conn->pcb.tcp, msg->conn);
+  tcp_accept(msg->conn->pcb.tcp, accept_function);
+      }
+#endif
+    default:
+      break;
+    }
+  }
+  sys_mbox_post(msg->conn->mbox, NULL);
+}
+
+static void
+do_accept(struct api_msg_msg *msg)
+{
+  if (msg->conn->pcb.tcp != NULL) {
+    switch (msg->conn->type) {
+#if LWIP_RAW
+    case NETCONN_RAW:
+      LWIP_DEBUGF(API_MSG_DEBUG, ("api_msg: accept RAW: cannot accept for RAW.\n"));
+      break;
+#endif
+#if LWIP_UDP
+    case NETCONN_UDPLITE:
+      /* FALLTHROUGH */
+    case NETCONN_UDPNOCHKSUM:
+      /* FALLTHROUGH */
+    case NETCONN_UDP:    
+      LWIP_DEBUGF(API_MSG_DEBUG, ("api_msg: accept UDP: cannot accept for UDP.\n"));
+      break;
+#endif /* LWIP_UDP */
+    case NETCONN_TCP:
+      break;
+    }
+  }
+}
+
+static void
+do_send(struct api_msg_msg *msg)
+{
+  if (msg->conn->pcb.tcp != NULL) {
+    switch (msg->conn->type) {
+#if LWIP_RAW
+    case NETCONN_RAW:
+      raw_send(msg->conn->pcb.raw, msg->msg.p);
+      break;
+#endif
+#if LWIP_UDP
+    case NETCONN_UDPLITE:
+      /* FALLTHROUGH */
+    case NETCONN_UDPNOCHKSUM:
+      /* FALLTHROUGH */
+    case NETCONN_UDP:
+      udp_send(msg->conn->pcb.udp, msg->msg.p);
+      break;
+#endif /* LWIP_UDP */
+    case NETCONN_TCP:
+      break;
+    }
+  }
+  sys_mbox_post(msg->conn->mbox, NULL);
+}
+
+static void
+do_recv(struct api_msg_msg *msg)
+{
+#if LWIP_TCP
+  if (msg->conn->pcb.tcp != NULL) {
+    if (msg->conn->type == NETCONN_TCP) {
+      tcp_recved(msg->conn->pcb.tcp, msg->msg.len);
+    }
+  }
+#endif  
+  sys_mbox_post(msg->conn->mbox, NULL);
+}
+
+static void
+do_write(struct api_msg_msg *msg)
+{
+#if LWIP_TCP  
+  err_t err;
+#endif  
+  if (msg->conn->pcb.tcp != NULL) {
+    switch (msg->conn->type) {
+#if LWIP_RAW
+    case NETCONN_RAW:
+      msg->conn->err = ERR_VAL;
+      break;
+#endif
+#if LWIP_UDP 
+    case NETCONN_UDPLITE:
+      /* FALLTHROUGH */
+    case NETCONN_UDPNOCHKSUM:
+      /* FALLTHROUGH */
+    case NETCONN_UDP:
+      msg->conn->err = ERR_VAL;
+      break;
+#endif /* LWIP_UDP */
+#if LWIP_TCP 
+    case NETCONN_TCP:      
+      err = tcp_write(msg->conn->pcb.tcp, msg->msg.w.dataptr,
+                      msg->msg.w.len, msg->msg.w.copy);
+      /* This is the Nagle algorithm: inhibit the sending of new TCP
+   segments when new outgoing data arrives from the user if any
+   previously transmitted data on the connection remains
+   unacknowledged. */
+      if(err == ERR_OK && (msg->conn->pcb.tcp->unacked == NULL || (msg->conn->pcb.tcp->flags & TF_NODELAY)) ) {
+  tcp_output(msg->conn->pcb.tcp);
+      }
+      msg->conn->err = err;
+      if (msg->conn->callback)
+          if (err == ERR_OK)
+          {
+              if (tcp_sndbuf(msg->conn->pcb.tcp) <= TCP_SNDLOWAT)
+                  (*msg->conn->callback)(msg->conn, NETCONN_EVT_SENDMINUS, msg->msg.w.len);
+          }
+#endif
+    default:
+      break;
+    }
+  }
+  sys_mbox_post(msg->conn->mbox, NULL);
+}
+
+static void
+do_close(struct api_msg_msg *msg)
+{
+  err_t err;
+
+  err = ERR_OK;
+
+  if (msg->conn->pcb.tcp != NULL) {
+    switch (msg->conn->type) {
+#if LWIP_RAW
+    case NETCONN_RAW:
+      break;
+#endif
+#if LWIP_UDP
+    case NETCONN_UDPLITE:
+      /* FALLTHROUGH */
+    case NETCONN_UDPNOCHKSUM:
+      /* FALLTHROUGH */
+    case NETCONN_UDP:
+      break;
+#endif /* LWIP_UDP */
+#if LWIP_TCP
+    case NETCONN_TCP:
+      if (msg->conn->pcb.tcp->state == LISTEN) {
+  err = tcp_close(msg->conn->pcb.tcp);
+      }
+      msg->conn->err = err;      
+#endif
+    default:      
+      break;
+    }
+  }
+  sys_mbox_post(msg->conn->mbox, NULL);
+}
+
+typedef void (* api_msg_decode)(struct api_msg_msg *msg);
+static api_msg_decode decode[API_MSG_MAX] = {
+  do_newconn,
+  do_delconn,
+  do_bind,
+  do_connect,
+  do_disconnect,
+  do_listen,
+  do_accept,
+  do_send,
+  do_recv,
+  do_write,
+  do_close
+  };
+void
+api_msg_input(struct api_msg *msg)
+{  
+  decode[msg->type](&(msg->msg));
+}
+
+void
+api_msg_post(struct api_msg *msg)
+{
+  tcpip_apimsg(msg);
+}
+
+
+