Diff: EthernetInterface/lwip/api/api_msg.c

Revision:

9:58eb378727d9

Parent:

8:80d49dd91542

Child:

10:0b5e0dfee08e

--- a/EthernetInterface/lwip/api/api_msg.c	Wed Oct 01 13:27:35 2014 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1535 +0,0 @@
-/**
- * @file
- * Sequential API Internal module
- *
- */
-
-/*
- * 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"
-
-#if LWIP_NETCONN /* don't build if not configured for use in lwipopts.h */
-
-#include "lwip/api_msg.h"
-
-#include "lwip/ip.h"
-#include "lwip/udp.h"
-#include "lwip/tcp.h"
-#include "lwip/raw.h"
-
-#include "lwip/memp.h"
-#include "lwip/tcpip.h"
-#include "lwip/igmp.h"
-#include "lwip/dns.h"
-
-#include <string.h>
-
-#define SET_NONBLOCKING_CONNECT(conn, val)  do { if(val) { \
-  (conn)->flags |= NETCONN_FLAG_IN_NONBLOCKING_CONNECT; \
-} else { \
-  (conn)->flags &= ~ NETCONN_FLAG_IN_NONBLOCKING_CONNECT; }} while(0)
-#define IN_NONBLOCKING_CONNECT(conn) (((conn)->flags & NETCONN_FLAG_IN_NONBLOCKING_CONNECT) != 0)
-
-/* forward declarations */
-#if LWIP_TCP
-static err_t do_writemore(struct netconn *conn);
-static void do_close_internal(struct netconn *conn);
-#endif
-
-#if LWIP_RAW
-/**
- * Receive callback function for RAW netconns.
- * Doesn't 'eat' the packet, only references it and sends it to
- * conn->recvmbox
- *
- * @see raw.h (struct raw_pcb.recv) for parameters and return value
- */
-static u8_t
-recv_raw(void *arg, struct raw_pcb *pcb, struct pbuf *p,
-    ip_addr_t *addr)
-{
-  struct pbuf *q;
-  struct netbuf *buf;
-  struct netconn *conn;
-
-  LWIP_UNUSED_ARG(addr);
-  conn = (struct netconn *)arg;
-
-  if ((conn != NULL) && sys_mbox_valid(&conn->recvmbox)) {
-#if LWIP_SO_RCVBUF
-    int recv_avail;
-    SYS_ARCH_GET(conn->recv_avail, recv_avail);
-    if ((recv_avail + (int)(p->tot_len)) > conn->recv_bufsize) {
-      return 0;
-    }
-#endif /* LWIP_SO_RCVBUF */
-    /* copy the whole packet into new pbufs */
-    q = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
-    if(q != NULL) {
-      if (pbuf_copy(q, p) != ERR_OK) {
-        pbuf_free(q);
-        q = NULL;
-      }
-    }
-
-    if (q != NULL) {
-      u16_t len;
-      buf = (struct netbuf *)memp_malloc(MEMP_NETBUF);
-      if (buf == NULL) {
-        pbuf_free(q);
-        return 0;
-      }
-
-      buf->p = q;
-      buf->ptr = q;
-      ip_addr_copy(buf->addr, *ip_current_src_addr());
-      buf->port = pcb->protocol;
-
-      len = q->tot_len;
-      if (sys_mbox_trypost(&conn->recvmbox, buf) != ERR_OK) {
-        netbuf_delete(buf);
-        return 0;
-      } else {
-#if LWIP_SO_RCVBUF
-        SYS_ARCH_INC(conn->recv_avail, len);
-#endif /* LWIP_SO_RCVBUF */
-        /* Register event with callback */
-        API_EVENT(conn, NETCONN_EVT_RCVPLUS, len);
-      }
-    }
-  }
-
-  return 0; /* do not eat the packet */
-}
-#endif /* LWIP_RAW*/
-
-#if LWIP_UDP
-/**
- * Receive callback function for UDP netconns.
- * Posts the packet to conn->recvmbox or deletes it on memory error.
- *
- * @see udp.h (struct udp_pcb.recv) for parameters
- */
-static void
-recv_udp(void *arg, struct udp_pcb *pcb, struct pbuf *p,
-   ip_addr_t *addr, u16_t port)
-{
-  struct netbuf *buf;
-  struct netconn *conn;
-  u16_t len;
-#if LWIP_SO_RCVBUF
-  int recv_avail;
-#endif /* LWIP_SO_RCVBUF */
-
-  LWIP_UNUSED_ARG(pcb); /* only used for asserts... */
-  LWIP_ASSERT("recv_udp must have a pcb argument", pcb != NULL);
-  LWIP_ASSERT("recv_udp must have an argument", arg != NULL);
-  conn = (struct netconn *)arg;
-  LWIP_ASSERT("recv_udp: recv for wrong pcb!", conn->pcb.udp == pcb);
-
-#if LWIP_SO_RCVBUF
-  SYS_ARCH_GET(conn->recv_avail, recv_avail);
-  if ((conn == NULL) || !sys_mbox_valid(&conn->recvmbox) ||
-      ((recv_avail + (int)(p->tot_len)) > conn->recv_bufsize)) {
-#else  /* LWIP_SO_RCVBUF */
-  if ((conn == NULL) || !sys_mbox_valid(&conn->recvmbox)) {
-#endif /* LWIP_SO_RCVBUF */
-    pbuf_free(p);
-    return;
-  }
-
-  buf = (struct netbuf *)memp_malloc(MEMP_NETBUF);
-  if (buf == NULL) {
-    pbuf_free(p);
-    return;
-  } else {
-    buf->p = p;
-    buf->ptr = p;
-    ip_addr_set(&buf->addr, addr);
-    buf->port = port;
-#if LWIP_NETBUF_RECVINFO
-    {
-      const struct ip_hdr* iphdr = ip_current_header();
-      /* get the UDP header - always in the first pbuf, ensured by udp_input */
-      const struct udp_hdr* udphdr = (void*)(((char*)iphdr) + IPH_LEN(iphdr));
-#if LWIP_CHECKSUM_ON_COPY
-      buf->flags = NETBUF_FLAG_DESTADDR;
-#endif /* LWIP_CHECKSUM_ON_COPY */
-      ip_addr_set(&buf->toaddr, ip_current_dest_addr());
-      buf->toport_chksum = udphdr->dest;
-    }
-#endif /* LWIP_NETBUF_RECVINFO */
-  }
-
-  len = p->tot_len;
-  if (sys_mbox_trypost(&conn->recvmbox, buf) != ERR_OK) {
-    netbuf_delete(buf);
-    return;
-  } else {
-#if LWIP_SO_RCVBUF
-    SYS_ARCH_INC(conn->recv_avail, len);
-#endif /* LWIP_SO_RCVBUF */
-    /* Register event with callback */
-    API_EVENT(conn, NETCONN_EVT_RCVPLUS, len);
-  }
-}
-#endif /* LWIP_UDP */
-
-#if LWIP_TCP
-/**
- * Receive callback function for TCP netconns.
- * Posts the packet to conn->recvmbox, but doesn't delete it on errors.
- *
- * @see tcp.h (struct tcp_pcb.recv) for parameters and return value
- */
-static err_t
-recv_tcp(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err)
-{
-  struct netconn *conn;
-  u16_t len;
-
-  LWIP_UNUSED_ARG(pcb);
-  LWIP_ASSERT("recv_tcp must have a pcb argument", pcb != NULL);
-  LWIP_ASSERT("recv_tcp must have an argument", arg != NULL);
-  conn = (struct netconn *)arg;
-  LWIP_ASSERT("recv_tcp: recv for wrong pcb!", conn->pcb.tcp == pcb);
-
-  if (conn == NULL) {
-    return ERR_VAL;
-  }
-  if (!sys_mbox_valid(&conn->recvmbox)) {
-    /* recvmbox already deleted */
-    if (p != NULL) {
-      tcp_recved(pcb, p->tot_len);
-      pbuf_free(p);
-    }
-    return ERR_OK;
-  }
-  /* Unlike for UDP or RAW pcbs, don't check for available space
-     using recv_avail since that could break the connection
-     (data is already ACKed) */
-
-  /* don't overwrite fatal errors! */
-  NETCONN_SET_SAFE_ERR(conn, err);
-
-  if (p != NULL) {
-    len = p->tot_len;
-  } else {
-    len = 0;
-  }
-
-  if (sys_mbox_trypost(&conn->recvmbox, p) != ERR_OK) {
-    /* don't deallocate p: it is presented to us later again from tcp_fasttmr! */
-    return ERR_MEM;
-  } else {
-#if LWIP_SO_RCVBUF
-    SYS_ARCH_INC(conn->recv_avail, len);
-#endif /* LWIP_SO_RCVBUF */
-    /* Register event with callback */
-    API_EVENT(conn, NETCONN_EVT_RCVPLUS, len);
-  }
-
-  return ERR_OK;
-}
-
-/**
- * Poll callback function for TCP netconns.
- * Wakes up an application thread that waits for a connection to close
- * or data to be sent. The application thread then takes the
- * appropriate action to go on.
- *
- * Signals the conn->sem.
- * netconn_close waits for conn->sem if closing failed.
- *
- * @see tcp.h (struct tcp_pcb.poll) for parameters and return value
- */
-static err_t
-poll_tcp(void *arg, struct tcp_pcb *pcb)
-{
-  struct netconn *conn = (struct netconn *)arg;
-
-  LWIP_UNUSED_ARG(pcb);
-  LWIP_ASSERT("conn != NULL", (conn != NULL));
-
-  if (conn->state == NETCONN_WRITE) {
-    do_writemore(conn);
-  } else if (conn->state == NETCONN_CLOSE) {
-    do_close_internal(conn);
-  }
-  /* @todo: implement connect timeout here? */
-
-  /* Did a nonblocking write fail before? Then check available write-space. */
-  if (conn->flags & NETCONN_FLAG_CHECK_WRITESPACE) {
-    /* If the queued byte- or pbuf-count drops below the configured low-water limit,
-       let select mark this pcb as writable again. */
-    if ((conn->pcb.tcp != NULL) && (tcp_sndbuf(conn->pcb.tcp) > TCP_SNDLOWAT) &&
-      (tcp_sndqueuelen(conn->pcb.tcp) < TCP_SNDQUEUELOWAT)) {
-      conn->flags &= ~NETCONN_FLAG_CHECK_WRITESPACE;
-      API_EVENT(conn, NETCONN_EVT_SENDPLUS, 0);
-    }
-  }
-
-  return ERR_OK;
-}
-
-/**
- * Sent callback function for TCP netconns.
- * Signals the conn->sem and calls API_EVENT.
- * netconn_write waits for conn->sem if send buffer is low.
- *
- * @see tcp.h (struct tcp_pcb.sent) for parameters and return value
- */
-static err_t
-sent_tcp(void *arg, struct tcp_pcb *pcb, u16_t len)
-{
-  struct netconn *conn = (struct netconn *)arg;
-
-  LWIP_UNUSED_ARG(pcb);
-  LWIP_ASSERT("conn != NULL", (conn != NULL));
-
-  if (conn->state == NETCONN_WRITE) {
-    do_writemore(conn);
-  } else if (conn->state == NETCONN_CLOSE) {
-    do_close_internal(conn);
-  }
-
-  if (conn) {
-    /* If the queued byte- or pbuf-count drops below the configured low-water limit,
-       let select mark this pcb as writable again. */
-    if ((conn->pcb.tcp != NULL) && (tcp_sndbuf(conn->pcb.tcp) > TCP_SNDLOWAT) &&
-      (tcp_sndqueuelen(conn->pcb.tcp) < TCP_SNDQUEUELOWAT)) {
-      conn->flags &= ~NETCONN_FLAG_CHECK_WRITESPACE;
-      API_EVENT(conn, NETCONN_EVT_SENDPLUS, len);
-    }
-  }
-  
-  return ERR_OK;
-}
-
-/**
- * Error callback function for TCP netconns.
- * Signals conn->sem, posts to all conn mboxes and calls API_EVENT.
- * The application thread has then to decide what to do.
- *
- * @see tcp.h (struct tcp_pcb.err) for parameters
- */
-static void
-err_tcp(void *arg, err_t err)
-{
-  struct netconn *conn;
-  enum netconn_state old_state;
-  SYS_ARCH_DECL_PROTECT(lev);
-
-  conn = (struct netconn *)arg;
-  LWIP_ASSERT("conn != NULL", (conn != NULL));
-
-  conn->pcb.tcp = NULL;
-
-  /* no check since this is always fatal! */
-  SYS_ARCH_PROTECT(lev);
-  conn->last_err = err;
-  SYS_ARCH_UNPROTECT(lev);
-
-  /* reset conn->state now before waking up other threads */
-  old_state = conn->state;
-  conn->state = NETCONN_NONE;
-
-  /* Notify the user layer about a connection error. Used to signal
-     select. */
-  API_EVENT(conn, NETCONN_EVT_ERROR, 0);
-  /* Try to release selects pending on 'read' or 'write', too.
-     They will get an error if they actually try to read or write. */
-  API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0);
-  API_EVENT(conn, NETCONN_EVT_SENDPLUS, 0);
-
-  /* pass NULL-message to recvmbox to wake up pending recv */
-  if (sys_mbox_valid(&conn->recvmbox)) {
-    /* use trypost to prevent deadlock */
-    sys_mbox_trypost(&conn->recvmbox, NULL);
-  }
-  /* pass NULL-message to acceptmbox to wake up pending accept */
-  if (sys_mbox_valid(&conn->acceptmbox)) {
-    /* use trypost to preven deadlock */
-    sys_mbox_trypost(&conn->acceptmbox, NULL);
-  }
-
-  if ((old_state == NETCONN_WRITE) || (old_state == NETCONN_CLOSE) ||
-      (old_state == NETCONN_CONNECT)) {
-    /* calling do_writemore/do_close_internal is not necessary
-       since the pcb has already been deleted! */
-    int was_nonblocking_connect = IN_NONBLOCKING_CONNECT(conn);
-    SET_NONBLOCKING_CONNECT(conn, 0);
-
-    if (!was_nonblocking_connect) {
-      /* set error return code */
-      LWIP_ASSERT("conn->current_msg != NULL", conn->current_msg != NULL);
-      conn->current_msg->err = err;
-      conn->current_msg = NULL;
-      /* wake up the waiting task */
-      sys_sem_signal(&conn->op_completed);
-    }
-  } else {
-    LWIP_ASSERT("conn->current_msg == NULL", conn->current_msg == NULL);
-  }
-}
-
-/**
- * Setup a tcp_pcb with the correct callback function pointers
- * and their arguments.
- *
- * @param conn the TCP netconn to setup
- */
-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);
-}
-
-/**
- * Accept callback function for TCP netconns.
- * Allocates a new netconn and posts that to conn->acceptmbox.
- *
- * @see tcp.h (struct tcp_pcb_listen.accept) for parameters and return value
- */
-static err_t
-accept_function(void *arg, struct tcp_pcb *newpcb, err_t err)
-{
-  struct netconn *newconn;
-  struct netconn *conn = (struct netconn *)arg;
-
-  LWIP_DEBUGF(API_MSG_DEBUG, ("accept_function: newpcb->tate: %s\n", tcp_debug_state_str(newpcb->state)));
-
-  if (!sys_mbox_valid(&conn->acceptmbox)) {
-    LWIP_DEBUGF(API_MSG_DEBUG, ("accept_function: acceptmbox already deleted\n"));
-    return ERR_VAL;
-  }
-
-  /* We have to set the callback here even though
-   * the new socket is unknown. conn->socket is marked as -1. */
-  newconn = netconn_alloc(conn->type, conn->callback);
-  if (newconn == NULL) {
-    return ERR_MEM;
-  }
-  newconn->pcb.tcp = newpcb;
-  setup_tcp(newconn);
-  /* no protection: when creating the pcb, the netconn is not yet known
-     to the application thread */
-  newconn->last_err = err;
-
-  if (sys_mbox_trypost(&conn->acceptmbox, newconn) != ERR_OK) {
-    /* When returning != ERR_OK, the pcb is aborted in tcp_process(),
-       so do nothing here! */
-    newconn->pcb.tcp = NULL;
-    /* no need to drain since we know the recvmbox is empty. */
-    sys_mbox_free(&newconn->recvmbox);
-    sys_mbox_set_invalid(&newconn->recvmbox);
-    netconn_free(newconn);
-    return ERR_MEM;
-  } else {
-    /* Register event with callback */
-    API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0);
-  }
-
-  return ERR_OK;
-}
-#endif /* LWIP_TCP */
-
-/**
- * Create a new pcb of a specific type.
- * Called from do_newconn().
- *
- * @param msg the api_msg_msg describing the connection type
- * @return msg->conn->err, but the return value is currently ignored
- */
-static void
-pcb_new(struct api_msg_msg *msg)
-{
-  LWIP_ASSERT("pcb_new: pcb already allocated", msg->conn->pcb.tcp == NULL);
-
-  /* Allocate a PCB for this connection */
-  switch(NETCONNTYPE_GROUP(msg->conn->type)) {
-#if LWIP_RAW
-  case NETCONN_RAW:
-    msg->conn->pcb.raw = raw_new(msg->msg.n.proto);
-    if(msg->conn->pcb.raw == NULL) {
-      msg->err = ERR_MEM;
-      break;
-    }
-    raw_recv(msg->conn->pcb.raw, recv_raw, msg->conn);
-    break;
-#endif /* LWIP_RAW */
-#if LWIP_UDP
-  case NETCONN_UDP:
-    msg->conn->pcb.udp = udp_new();
-    if(msg->conn->pcb.udp == NULL) {
-      msg->err = ERR_MEM;
-      break;
-    }
-#if LWIP_UDPLITE
-    if (msg->conn->type==NETCONN_UDPLITE) {
-      udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_UDPLITE);
-    }
-#endif /* LWIP_UDPLITE */
-    if (msg->conn->type==NETCONN_UDPNOCHKSUM) {
-      udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_NOCHKSUM);
-    }
-    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->err = ERR_MEM;
-      break;
-    }
-    setup_tcp(msg->conn);
-    break;
-#endif /* LWIP_TCP */
-  default:
-    /* Unsupported netconn type, e.g. protocol disabled */
-    msg->err = ERR_VAL;
-    break;
-  }
-}
-
-/**
- * Create a new pcb of a specific type inside a netconn.
- * Called from netconn_new_with_proto_and_callback.
- *
- * @param msg the api_msg_msg describing the connection type
- */
-void
-do_newconn(struct api_msg_msg *msg)
-{
-  msg->err = ERR_OK;
-  if(msg->conn->pcb.tcp == NULL) {
-    pcb_new(msg);
-  }
-  /* Else? This "new" connection already has a PCB allocated. */
-  /* Is this an error condition? Should it be deleted? */
-  /* We currently just are happy and return. */
-
-  TCPIP_APIMSG_ACK(msg);
-}
-
-/**
- * Create a new netconn (of a specific type) that has a callback function.
- * The corresponding pcb is NOT created!
- *
- * @param t the type of 'connection' to create (@see enum netconn_type)
- * @param proto the IP protocol for RAW IP pcbs
- * @param callback a function to call on status changes (RX available, TX'ed)
- * @return a newly allocated struct netconn or
- *         NULL on memory error
- */
-struct netconn*
-netconn_alloc(enum netconn_type t, netconn_callback callback)
-{
-  struct netconn *conn;
-  int size;
-
-  conn = (struct netconn *)memp_malloc(MEMP_NETCONN);
-  if (conn == NULL) {
-    return NULL;
-  }
-
-  conn->last_err = ERR_OK;
-  conn->type = t;
-  conn->pcb.tcp = NULL;
-
-#if (DEFAULT_RAW_RECVMBOX_SIZE == DEFAULT_UDP_RECVMBOX_SIZE) && \
-    (DEFAULT_RAW_RECVMBOX_SIZE == DEFAULT_TCP_RECVMBOX_SIZE)
-  size = DEFAULT_RAW_RECVMBOX_SIZE;
-#else
-  switch(NETCONNTYPE_GROUP(t)) {
-#if LWIP_RAW
-  case NETCONN_RAW:
-    size = DEFAULT_RAW_RECVMBOX_SIZE;
-    break;
-#endif /* LWIP_RAW */
-#if LWIP_UDP
-  case NETCONN_UDP:
-    size = DEFAULT_UDP_RECVMBOX_SIZE;
-    break;
-#endif /* LWIP_UDP */
-#if LWIP_TCP
-  case NETCONN_TCP:
-    size = DEFAULT_TCP_RECVMBOX_SIZE;
-    break;
-#endif /* LWIP_TCP */
-  default:
-    LWIP_ASSERT("netconn_alloc: undefined netconn_type", 0);
-    break;
-  }
-#endif
-
-  if (sys_sem_new(&conn->op_completed, 0) != ERR_OK) {
-    memp_free(MEMP_NETCONN, conn);
-    return NULL;
-  }
-  if (sys_mbox_new(&conn->recvmbox, size) != ERR_OK) {
-    sys_sem_free(&conn->op_completed);
-    memp_free(MEMP_NETCONN, conn);
-    return NULL;
-  }
-
-#if LWIP_TCP
-  sys_mbox_set_invalid(&conn->acceptmbox);
-#endif
-  conn->state        = NETCONN_NONE;
-#if LWIP_SOCKET
-  /* initialize socket to -1 since 0 is a valid socket */
-  conn->socket       = -1;
-#endif /* LWIP_SOCKET */
-  conn->callback     = callback;
-#if LWIP_TCP
-  conn->current_msg  = NULL;
-  conn->write_offset = 0;
-#endif /* LWIP_TCP */
-#if LWIP_SO_RCVTIMEO
-  conn->recv_timeout = 0;
-#endif /* LWIP_SO_RCVTIMEO */
-#if LWIP_SO_RCVBUF
-  conn->recv_bufsize = RECV_BUFSIZE_DEFAULT;
-  conn->recv_avail   = 0;
-#endif /* LWIP_SO_RCVBUF */
-  conn->flags = 0;
-  return conn;
-}
-
-/**
- * Delete a netconn and all its resources.
- * The pcb is NOT freed (since we might not be in the right thread context do this).
- *
- * @param conn the netconn to free
- */
-void
-netconn_free(struct netconn *conn)
-{
-  LWIP_ASSERT("PCB must be deallocated outside this function", conn->pcb.tcp == NULL);
-  LWIP_ASSERT("recvmbox must be deallocated before calling this function",
-    !sys_mbox_valid(&conn->recvmbox));
-#if LWIP_TCP
-  LWIP_ASSERT("acceptmbox must be deallocated before calling this function",
-    !sys_mbox_valid(&conn->acceptmbox));
-#endif /* LWIP_TCP */
-
-  sys_sem_free(&conn->op_completed);
-  sys_sem_set_invalid(&conn->op_completed);
-
-  memp_free(MEMP_NETCONN, conn);
-}
-
-/**
- * Delete rcvmbox and acceptmbox of a netconn and free the left-over data in
- * these mboxes
- *
- * @param conn the netconn to free
- * @bytes_drained bytes drained from recvmbox
- * @accepts_drained pending connections drained from acceptmbox
- */
-static void
-netconn_drain(struct netconn *conn)
-{
-  void *mem;
-#if LWIP_TCP
-  struct pbuf *p;
-#endif /* LWIP_TCP */
-
-  /* This runs in tcpip_thread, so we don't need to lock against rx packets */
-
-  /* Delete and drain the recvmbox. */
-  if (sys_mbox_valid(&conn->recvmbox)) {
-    while (sys_mbox_tryfetch(&conn->recvmbox, &mem) != SYS_MBOX_EMPTY) {
-#if LWIP_TCP
-      if (conn->type == NETCONN_TCP) {
-        if(mem != NULL) {
-          p = (struct pbuf*)mem;
-          /* pcb might be set to NULL already by err_tcp() */
-          if (conn->pcb.tcp != NULL) {
-            tcp_recved(conn->pcb.tcp, p->tot_len);
-          }
-          pbuf_free(p);
-        }
-      } else
-#endif /* LWIP_TCP */
-      {
-        netbuf_delete((struct netbuf *)mem);
-      }
-    }
-    sys_mbox_free(&conn->recvmbox);
-    sys_mbox_set_invalid(&conn->recvmbox);
-  }
-
-  /* Delete and drain the acceptmbox. */
-#if LWIP_TCP
-  if (sys_mbox_valid(&conn->acceptmbox)) {
-    while (sys_mbox_tryfetch(&conn->acceptmbox, &mem) != SYS_MBOX_EMPTY) {
-      struct netconn *newconn = (struct netconn *)mem;
-      /* Only tcp pcbs have an acceptmbox, so no need to check conn->type */
-      /* pcb might be set to NULL already by err_tcp() */
-      if (conn->pcb.tcp != NULL) {
-        tcp_accepted(conn->pcb.tcp);
-      }
-      /* drain recvmbox */
-      netconn_drain(newconn);
-      if (newconn->pcb.tcp != NULL) {
-        tcp_abort(newconn->pcb.tcp);
-        newconn->pcb.tcp = NULL;
-      }
-      netconn_free(newconn);
-    }
-    sys_mbox_free(&conn->acceptmbox);
-    sys_mbox_set_invalid(&conn->acceptmbox);
-  }
-#endif /* LWIP_TCP */
-}
-
-#if LWIP_TCP
-/**
- * Internal helper function to close a TCP netconn: since this sometimes
- * doesn't work at the first attempt, this function is called from multiple
- * places.
- *
- * @param conn the TCP netconn to close
- */
-static void
-do_close_internal(struct netconn *conn)
-{
-  err_t err;
-  u8_t shut, shut_rx, shut_tx, close;
-
-  LWIP_ASSERT("invalid conn", (conn != NULL));
-  LWIP_ASSERT("this is for tcp netconns only", (conn->type == NETCONN_TCP));
-  LWIP_ASSERT("conn must be in state NETCONN_CLOSE", (conn->state == NETCONN_CLOSE));
-  LWIP_ASSERT("pcb already closed", (conn->pcb.tcp != NULL));
-  LWIP_ASSERT("conn->current_msg != NULL", conn->current_msg != NULL);
-
-  shut = conn->current_msg->msg.sd.shut;
-  shut_rx = shut & NETCONN_SHUT_RD;
-  shut_tx = shut & NETCONN_SHUT_WR;
-  /* shutting down both ends is the same as closing */
-  close = shut == NETCONN_SHUT_RDWR;
-
-  /* Set back some callback pointers */
-  if (close) {
-    tcp_arg(conn->pcb.tcp, NULL);
-  }
-  if (conn->pcb.tcp->state == LISTEN) {
-    tcp_accept(conn->pcb.tcp, NULL);
-  } else {
-    /* some callbacks have to be reset if tcp_close is not successful */
-    if (shut_rx) {
-      tcp_recv(conn->pcb.tcp, NULL);
-      tcp_accept(conn->pcb.tcp, NULL);
-    }
-    if (shut_tx) {
-      tcp_sent(conn->pcb.tcp, NULL);
-    }
-    if (close) {
-      tcp_poll(conn->pcb.tcp, NULL, 4);
-      tcp_err(conn->pcb.tcp, NULL);
-    }
-  }
-  /* Try to close the connection */
-  if (shut == NETCONN_SHUT_RDWR) {
-    err = tcp_close(conn->pcb.tcp);
-  } else {
-    err = tcp_shutdown(conn->pcb.tcp, shut & NETCONN_SHUT_RD, shut & NETCONN_SHUT_WR);
-  }
-  if (err == ERR_OK) {
-    /* Closing succeeded */
-    conn->current_msg->err = ERR_OK;
-    conn->current_msg = NULL;
-    conn->state = NETCONN_NONE;
-    /* Set back some callback pointers as conn is going away */
-    conn->pcb.tcp = NULL;
-    /* Trigger select() in socket layer. Make sure everybody notices activity
-       on the connection, error first! */
-    if (close) {
-      API_EVENT(conn, NETCONN_EVT_ERROR, 0);
-    }
-    if (shut_rx) {
-      API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0);
-    }
-    if (shut_tx) {
-      API_EVENT(conn, NETCONN_EVT_SENDPLUS, 0);
-    }
-    /* wake up the application task */
-    sys_sem_signal(&conn->op_completed);
-  } else {
-    /* Closing failed, restore some of the callbacks */
-    /* Closing of listen pcb will never fail! */
-    LWIP_ASSERT("Closing a listen pcb may not fail!", (conn->pcb.tcp->state != LISTEN));
-    tcp_sent(conn->pcb.tcp, sent_tcp);
-    tcp_poll(conn->pcb.tcp, poll_tcp, 4);
-    tcp_err(conn->pcb.tcp, err_tcp);
-    tcp_arg(conn->pcb.tcp, conn);
-    /* don't restore recv callback: we don't want to receive any more data */
-  }
-  /* If closing didn't succeed, we get called again either
-     from poll_tcp or from sent_tcp */
-}
-#endif /* LWIP_TCP */
-
-/**
- * Delete the pcb inside a netconn.
- * Called from netconn_delete.
- *
- * @param msg the api_msg_msg pointing to the connection
- */
-void
-do_delconn(struct api_msg_msg *msg)
-{
-  /* @todo TCP: abort running write/connect? */
- if ((msg->conn->state != NETCONN_NONE) &&
-     (msg->conn->state != NETCONN_LISTEN) &&
-     (msg->conn->state != NETCONN_CONNECT)) {
-    /* this only happens for TCP netconns */
-    LWIP_ASSERT("msg->conn->type == NETCONN_TCP", msg->conn->type == NETCONN_TCP);
-    msg->err = ERR_INPROGRESS;
-  } else {
-    LWIP_ASSERT("blocking connect in progress",
-      (msg->conn->state != NETCONN_CONNECT) || IN_NONBLOCKING_CONNECT(msg->conn));
-    /* Drain and delete mboxes */
-    netconn_drain(msg->conn);
-
-    if (msg->conn->pcb.tcp != NULL) {
-
-      switch (NETCONNTYPE_GROUP(msg->conn->type)) {
-#if LWIP_RAW
-      case NETCONN_RAW:
-        raw_remove(msg->conn->pcb.raw);
-        break;
-#endif /* LWIP_RAW */
-#if LWIP_UDP
-      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:
-        LWIP_ASSERT("already writing or closing", msg->conn->current_msg == NULL &&
-          msg->conn->write_offset == 0);
-        msg->conn->state = NETCONN_CLOSE;
-        msg->msg.sd.shut = NETCONN_SHUT_RDWR;
-        msg->conn->current_msg = msg;
-        do_close_internal(msg->conn);
-        /* API_EVENT is called inside do_close_internal, before releasing
-           the application thread, so we can return at this point! */
-        return;
-#endif /* LWIP_TCP */
-      default:
-        break;
-      }
-      msg->conn->pcb.tcp = NULL;
-    }
-    /* tcp netconns don't come here! */
-
-    /* @todo: this lets select make the socket readable and writable,
-       which is wrong! errfd instead? */
-    API_EVENT(msg->conn, NETCONN_EVT_RCVPLUS, 0);
-    API_EVENT(msg->conn, NETCONN_EVT_SENDPLUS, 0);
-  }
-  if (sys_sem_valid(&msg->conn->op_completed)) {
-    sys_sem_signal(&msg->conn->op_completed);
-  }
-}
-
-/**
- * Bind a pcb contained in a netconn
- * Called from netconn_bind.
- *
- * @param msg the api_msg_msg pointing to the connection and containing
- *            the IP address and port to bind to
- */
-void
-do_bind(struct api_msg_msg *msg)
-{
-  if (ERR_IS_FATAL(msg->conn->last_err)) {
-    msg->err = msg->conn->last_err;
-  } else {
-    msg->err = ERR_VAL;
-    if (msg->conn->pcb.tcp != NULL) {
-      switch (NETCONNTYPE_GROUP(msg->conn->type)) {
-#if LWIP_RAW
-      case NETCONN_RAW:
-        msg->err = raw_bind(msg->conn->pcb.raw, msg->msg.bc.ipaddr);
-        break;
-#endif /* LWIP_RAW */
-#if LWIP_UDP
-      case NETCONN_UDP:
-        msg->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->err = tcp_bind(msg->conn->pcb.tcp, msg->msg.bc.ipaddr, msg->msg.bc.port);
-        break;
-#endif /* LWIP_TCP */
-      default:
-        break;
-      }
-    }
-  }
-  TCPIP_APIMSG_ACK(msg);
-}
-
-#if LWIP_TCP
-/**
- * TCP callback function if a connection (opened by tcp_connect/do_connect) has
- * been established (or reset by the remote host).
- *
- * @see tcp.h (struct tcp_pcb.connected) for parameters and return values
- */
-static err_t
-do_connected(void *arg, struct tcp_pcb *pcb, err_t err)
-{
-  struct netconn *conn;
-  int was_blocking;
-
-  LWIP_UNUSED_ARG(pcb);
-
-  conn = (struct netconn *)arg;
-
-  if (conn == NULL) {
-    return ERR_VAL;
-  }
-
-  LWIP_ASSERT("conn->state == NETCONN_CONNECT", conn->state == NETCONN_CONNECT);
-  LWIP_ASSERT("(conn->current_msg != NULL) || conn->in_non_blocking_connect",
-    (conn->current_msg != NULL) || IN_NONBLOCKING_CONNECT(conn));
-
-  if (conn->current_msg != NULL) {
-    conn->current_msg->err = err;
-  }
-  if ((conn->type == NETCONN_TCP) && (err == ERR_OK)) {
-    setup_tcp(conn);
-  }
-  was_blocking = !IN_NONBLOCKING_CONNECT(conn);
-  SET_NONBLOCKING_CONNECT(conn, 0);
-  conn->current_msg = NULL;
-  conn->state = NETCONN_NONE;
-  if (!was_blocking) {
-    NETCONN_SET_SAFE_ERR(conn, ERR_OK);
-  }
-  API_EVENT(conn, NETCONN_EVT_SENDPLUS, 0);
-
-  if (was_blocking) {
-    sys_sem_signal(&conn->op_completed);
-  }
-  return ERR_OK;
-}
-#endif /* LWIP_TCP */
-
-/**
- * Connect a pcb contained inside a netconn
- * Called from netconn_connect.
- *
- * @param msg the api_msg_msg pointing to the connection and containing
- *            the IP address and port to connect to
- */
-void
-do_connect(struct api_msg_msg *msg)
-{
-  if (msg->conn->pcb.tcp == NULL) {
-    /* This may happen when calling netconn_connect() a second time */
-    msg->err = ERR_CLSD;
-  } else {
-    switch (NETCONNTYPE_GROUP(msg->conn->type)) {
-#if LWIP_RAW
-  case NETCONN_RAW:
-    msg->err = raw_connect(msg->conn->pcb.raw, msg->msg.bc.ipaddr);
-    break;
-#endif /* LWIP_RAW */
-#if LWIP_UDP
-  case NETCONN_UDP:
-    msg->err = udp_connect(msg->conn->pcb.udp, msg->msg.bc.ipaddr, msg->msg.bc.port);
-    break;
-#endif /* LWIP_UDP */
-#if LWIP_TCP
-  case NETCONN_TCP:
-    /* Prevent connect while doing any other action. */
-    if (msg->conn->state != NETCONN_NONE) {
-      msg->err = ERR_ISCONN;
-    } else {
-      setup_tcp(msg->conn);
-      msg->err = tcp_connect(msg->conn->pcb.tcp, msg->msg.bc.ipaddr,
-        msg->msg.bc.port, do_connected);
-      if (msg->err == ERR_OK) {
-        u8_t non_blocking = netconn_is_nonblocking(msg->conn);
-        msg->conn->state = NETCONN_CONNECT;
-        SET_NONBLOCKING_CONNECT(msg->conn, non_blocking);
-        if (non_blocking) {
-          msg->err = ERR_INPROGRESS;
-        } else {
-          msg->conn->current_msg = msg;
-          /* sys_sem_signal() is called from do_connected (or err_tcp()),
-          * when the connection is established! */
-          return;
-        }
-      }
-    }
-    break;
-#endif /* LWIP_TCP */
-  default:
-    LWIP_ERROR("Invalid netconn type", 0, do{ msg->err = ERR_VAL; }while(0));
-    break;
-    }
-  }
-  sys_sem_signal(&msg->conn->op_completed);
-}
-
-/**
- * Connect a pcb contained inside a netconn
- * Only used for UDP netconns.
- * Called from netconn_disconnect.
- *
- * @param msg the api_msg_msg pointing to the connection to disconnect
- */
-void
-do_disconnect(struct api_msg_msg *msg)
-{
-#if LWIP_UDP
-  if (NETCONNTYPE_GROUP(msg->conn->type) == NETCONN_UDP) {
-    udp_disconnect(msg->conn->pcb.udp);
-    msg->err = ERR_OK;
-  } else
-#endif /* LWIP_UDP */
-  {
-    msg->err = ERR_VAL;
-  }
-  TCPIP_APIMSG_ACK(msg);
-}
-
-#if LWIP_TCP
-/**
- * Set a TCP pcb contained in a netconn into listen mode
- * Called from netconn_listen.
- *
- * @param msg the api_msg_msg pointing to the connection
- */
-void
-do_listen(struct api_msg_msg *msg)
-{
-  if (ERR_IS_FATAL(msg->conn->last_err)) {
-    msg->err = msg->conn->last_err;
-  } else {
-    msg->err = ERR_CONN;
-    if (msg->conn->pcb.tcp != NULL) {
-      if (msg->conn->type == NETCONN_TCP) {
-        if (msg->conn->state == NETCONN_NONE) {
-#if TCP_LISTEN_BACKLOG
-          struct tcp_pcb* lpcb = tcp_listen_with_backlog(msg->conn->pcb.tcp, msg->msg.lb.backlog);
-#else  /* TCP_LISTEN_BACKLOG */
-          struct tcp_pcb* lpcb = tcp_listen(msg->conn->pcb.tcp);
-#endif /* TCP_LISTEN_BACKLOG */
-          if (lpcb == NULL) {
-            /* in this case, the old pcb is still allocated */
-            msg->err = ERR_MEM;
-          } else {
-            /* delete the recvmbox and allocate the acceptmbox */
-            if (sys_mbox_valid(&msg->conn->recvmbox)) {
-              /** @todo: should we drain the recvmbox here? */
-              sys_mbox_free(&msg->conn->recvmbox);
-              sys_mbox_set_invalid(&msg->conn->recvmbox);
-            }
-            msg->err = ERR_OK;
-            if (!sys_mbox_valid(&msg->conn->acceptmbox)) {
-              msg->err = sys_mbox_new(&msg->conn->acceptmbox, DEFAULT_ACCEPTMBOX_SIZE);
-            }
-            if (msg->err == ERR_OK) {
-              msg->conn->state = NETCONN_LISTEN;
-              msg->conn->pcb.tcp = lpcb;
-              tcp_arg(msg->conn->pcb.tcp, msg->conn);
-              tcp_accept(msg->conn->pcb.tcp, accept_function);
-            } else {
-              /* since the old pcb is already deallocated, free lpcb now */
-              tcp_close(lpcb);
-              msg->conn->pcb.tcp = NULL;
-            }
-          }
-        }
-      }
-    }
-  }
-  TCPIP_APIMSG_ACK(msg);
-}
-#endif /* LWIP_TCP */
-
-/**
- * Send some data on a RAW or UDP pcb contained in a netconn
- * Called from netconn_send
- *
- * @param msg the api_msg_msg pointing to the connection
- */
-void
-do_send(struct api_msg_msg *msg)
-{
-  if (ERR_IS_FATAL(msg->conn->last_err)) {
-    msg->err = msg->conn->last_err;
-  } else {
-    msg->err = ERR_CONN;
-    if (msg->conn->pcb.tcp != NULL) {
-      switch (NETCONNTYPE_GROUP(msg->conn->type)) {
-#if LWIP_RAW
-      case NETCONN_RAW:
-        if (ip_addr_isany(&msg->msg.b->addr)) {
-          msg->err = raw_send(msg->conn->pcb.raw, msg->msg.b->p);
-        } else {
-          msg->err = raw_sendto(msg->conn->pcb.raw, msg->msg.b->p, &msg->msg.b->addr);
-        }
-        break;
-#endif
-#if LWIP_UDP
-      case NETCONN_UDP:
-#if LWIP_CHECKSUM_ON_COPY
-        if (ip_addr_isany(&msg->msg.b->addr)) {
-          msg->err = udp_send_chksum(msg->conn->pcb.udp, msg->msg.b->p,
-            msg->msg.b->flags & NETBUF_FLAG_CHKSUM, msg->msg.b->toport_chksum);
-        } else {
-          msg->err = udp_sendto_chksum(msg->conn->pcb.udp, msg->msg.b->p,
-            &msg->msg.b->addr, msg->msg.b->port,
-            msg->msg.b->flags & NETBUF_FLAG_CHKSUM, msg->msg.b->toport_chksum);
-        }
-#else /* LWIP_CHECKSUM_ON_COPY */
-        if (ip_addr_isany(&msg->msg.b->addr)) {
-          msg->err = udp_send(msg->conn->pcb.udp, msg->msg.b->p);
-        } else {
-          msg->err = udp_sendto(msg->conn->pcb.udp, msg->msg.b->p, &msg->msg.b->addr, msg->msg.b->port);
-        }
-#endif /* LWIP_CHECKSUM_ON_COPY */
-        break;
-#endif /* LWIP_UDP */
-      default:
-        break;
-      }
-    }
-  }
-  TCPIP_APIMSG_ACK(msg);
-}
-
-#if LWIP_TCP
-/**
- * Indicate data has been received from a TCP pcb contained in a netconn
- * Called from netconn_recv
- *
- * @param msg the api_msg_msg pointing to the connection
- */
-void
-do_recv(struct api_msg_msg *msg)
-{
-  msg->err = ERR_OK;
-  if (msg->conn->pcb.tcp != NULL) {
-    if (msg->conn->type == NETCONN_TCP) {
-#if TCP_LISTEN_BACKLOG
-      if (msg->conn->pcb.tcp->state == LISTEN) {
-        tcp_accepted(msg->conn->pcb.tcp);
-      } else
-#endif /* TCP_LISTEN_BACKLOG */
-      {
-        u32_t remaining = msg->msg.r.len;
-        do {
-          u16_t recved = (remaining > 0xffff) ? 0xffff : (u16_t)remaining;
-          tcp_recved(msg->conn->pcb.tcp, recved);
-          remaining -= recved;
-        }while(remaining != 0);
-      }
-    }
-  }
-  TCPIP_APIMSG_ACK(msg);
-}
-
-/**
- * See if more data needs to be written from a previous call to netconn_write.
- * Called initially from do_write. If the first call can't send all data
- * (because of low memory or empty send-buffer), this function is called again
- * from sent_tcp() or poll_tcp() to send more data. If all data is sent, the
- * blocking application thread (waiting in netconn_write) is released.
- *
- * @param conn netconn (that is currently in state NETCONN_WRITE) to process
- * @return ERR_OK
- *         ERR_MEM if LWIP_TCPIP_CORE_LOCKING=1 and sending hasn't yet finished
- */
-static err_t
-do_writemore(struct netconn *conn)
-{
-  err_t err = ERR_OK;
-  void *dataptr;
-  u16_t len, available;
-  u8_t write_finished = 0;
-  size_t diff;
-  u8_t dontblock = netconn_is_nonblocking(conn) ||
-       (conn->current_msg->msg.w.apiflags & NETCONN_DONTBLOCK);
-  u8_t apiflags = conn->current_msg->msg.w.apiflags;
-
-  LWIP_ASSERT("conn != NULL", conn != NULL);
-  LWIP_ASSERT("conn->state == NETCONN_WRITE", (conn->state == NETCONN_WRITE));
-  LWIP_ASSERT("conn->current_msg != NULL", conn->current_msg != NULL);
-  LWIP_ASSERT("conn->pcb.tcp != NULL", conn->pcb.tcp != NULL);
-  LWIP_ASSERT("conn->write_offset < conn->current_msg->msg.w.len",
-    conn->write_offset < conn->current_msg->msg.w.len);
-
-  dataptr = (u8_t*)conn->current_msg->msg.w.dataptr + conn->write_offset;
-  diff = conn->current_msg->msg.w.len - conn->write_offset;
-  if (diff > 0xffffUL) { /* max_u16_t */
-    len = 0xffff;
-#if LWIP_TCPIP_CORE_LOCKING
-    conn->flags |= NETCONN_FLAG_WRITE_DELAYED;
-#endif
-    apiflags |= TCP_WRITE_FLAG_MORE;
-  } else {
-    len = (u16_t)diff;
-  }
-  available = tcp_sndbuf(conn->pcb.tcp);
-  if (available < len) {
-    /* don't try to write more than sendbuf */
-    len = available;
-#if LWIP_TCPIP_CORE_LOCKING
-    conn->flags |= NETCONN_FLAG_WRITE_DELAYED;
-#endif
-    apiflags |= TCP_WRITE_FLAG_MORE;
-  }
-  if (dontblock && (len < conn->current_msg->msg.w.len)) {
-    /* failed to send all data at once -> nonblocking write not possible */
-    err = ERR_MEM;
-  }
-  if (err == ERR_OK) {
-    LWIP_ASSERT("do_writemore: invalid length!", ((conn->write_offset + len) <= conn->current_msg->msg.w.len));
-    err = tcp_write(conn->pcb.tcp, dataptr, len, apiflags);
-  }
-  if (dontblock && (err == ERR_MEM)) {
-    /* nonblocking write failed */
-    write_finished = 1;
-    err = ERR_WOULDBLOCK;
-    /* let poll_tcp check writable space to mark the pcb
-       writable again */
-    conn->flags |= NETCONN_FLAG_CHECK_WRITESPACE;
-    /* let select mark this pcb as non-writable. */
-    API_EVENT(conn, NETCONN_EVT_SENDMINUS, len);
-  } else {
-    /* if OK or memory error, check available space */
-    if (((err == ERR_OK) || (err == ERR_MEM)) &&
-        ((tcp_sndbuf(conn->pcb.tcp) <= TCP_SNDLOWAT) ||
-         (tcp_sndqueuelen(conn->pcb.tcp) >= TCP_SNDQUEUELOWAT))) {
-      /* The queued byte- or pbuf-count exceeds the configured low-water limit,
-         let select mark this pcb as non-writable. */
-      API_EVENT(conn, NETCONN_EVT_SENDMINUS, len);
-    }
-
-    if (err == ERR_OK) {
-      conn->write_offset += len;
-      if (conn->write_offset == conn->current_msg->msg.w.len) {
-        /* everything was written */
-        write_finished = 1;
-        conn->write_offset = 0;
-      }
-      tcp_output(conn->pcb.tcp);
-    } else if (err == ERR_MEM) {
-      /* If ERR_MEM, we wait for sent_tcp or poll_tcp to be called
-         we do NOT return to the application thread, since ERR_MEM is
-         only a temporary error! */
-
-      /* tcp_write returned ERR_MEM, try tcp_output anyway */
-      tcp_output(conn->pcb.tcp);
-
-  #if LWIP_TCPIP_CORE_LOCKING
-      conn->flags |= NETCONN_FLAG_WRITE_DELAYED;
-  #endif
-    } else {
-      /* On errors != ERR_MEM, we don't try writing any more but return
-         the error to the application thread. */
-      write_finished = 1;
-    }
-  }
-
-  if (write_finished) {
-    /* everything was written: set back connection state
-       and back to application task */
-    conn->current_msg->err = err;
-    conn->current_msg = NULL;
-    conn->state = NETCONN_NONE;
-#if LWIP_TCPIP_CORE_LOCKING
-    if ((conn->flags & NETCONN_FLAG_WRITE_DELAYED) != 0)
-#endif
-    {
-      sys_sem_signal(&conn->op_completed);
-    }
-  }
-#if LWIP_TCPIP_CORE_LOCKING
-  else
-    return ERR_MEM;
-#endif
-  return ERR_OK;
-}
-#endif /* LWIP_TCP */
-
-/**
- * Send some data on a TCP pcb contained in a netconn
- * Called from netconn_write
- *
- * @param msg the api_msg_msg pointing to the connection
- */
-void
-do_write(struct api_msg_msg *msg)
-{
-  if (ERR_IS_FATAL(msg->conn->last_err)) {
-    msg->err = msg->conn->last_err;
-  } else {
-    if (msg->conn->type == NETCONN_TCP) {
-#if LWIP_TCP
-      if (msg->conn->state != NETCONN_NONE) {
-        /* netconn is connecting, closing or in blocking write */
-        msg->err = ERR_INPROGRESS;
-      } else if (msg->conn->pcb.tcp != NULL) {
-        msg->conn->state = NETCONN_WRITE;
-        /* set all the variables used by do_writemore */
-        LWIP_ASSERT("already writing or closing", msg->conn->current_msg == NULL &&
-          msg->conn->write_offset == 0);
-        LWIP_ASSERT("msg->msg.w.len != 0", msg->msg.w.len != 0);
-        msg->conn->current_msg = msg;
-        msg->conn->write_offset = 0;
-#if LWIP_TCPIP_CORE_LOCKING
-        msg->conn->flags &= ~NETCONN_FLAG_WRITE_DELAYED;
-        if (do_writemore(msg->conn) != ERR_OK) {
-          LWIP_ASSERT("state!", msg->conn->state == NETCONN_WRITE);
-          UNLOCK_TCPIP_CORE();
-          sys_arch_sem_wait(&msg->conn->op_completed, 0);
-          LOCK_TCPIP_CORE();
-          LWIP_ASSERT("state!", msg->conn->state == NETCONN_NONE);
-        }
-#else /* LWIP_TCPIP_CORE_LOCKING */
-        do_writemore(msg->conn);
-#endif /* LWIP_TCPIP_CORE_LOCKING */
-        /* for both cases: if do_writemore was called, don't ACK the APIMSG
-           since do_writemore ACKs it! */
-        return;
-      } else {
-        msg->err = ERR_CONN;
-      }
-#else /* LWIP_TCP */
-      msg->err = ERR_VAL;
-#endif /* LWIP_TCP */
-#if (LWIP_UDP || LWIP_RAW)
-    } else {
-      msg->err = ERR_VAL;
-#endif /* (LWIP_UDP || LWIP_RAW) */
-    }
-  }
-  TCPIP_APIMSG_ACK(msg);
-}
-
-/**
- * Return a connection's local or remote address
- * Called from netconn_getaddr
- *
- * @param msg the api_msg_msg pointing to the connection
- */
-void
-do_getaddr(struct api_msg_msg *msg)
-{
-  if (msg->conn->pcb.ip != NULL) {
-    *(msg->msg.ad.ipaddr) = (msg->msg.ad.local ? msg->conn->pcb.ip->local_ip :
-                             msg->conn->pcb.ip->remote_ip);
-
-    msg->err = ERR_OK;
-    switch (NETCONNTYPE_GROUP(msg->conn->type)) {
-#if LWIP_RAW
-    case NETCONN_RAW:
-      if (msg->msg.ad.local) {
-        *(msg->msg.ad.port) = msg->conn->pcb.raw->protocol;
-      } else {
-        /* return an error as connecting is only a helper for upper layers */
-        msg->err = ERR_CONN;
-      }
-      break;
-#endif /* LWIP_RAW */
-#if LWIP_UDP
-    case NETCONN_UDP:
-      if (msg->msg.ad.local) {
-        *(msg->msg.ad.port) = msg->conn->pcb.udp->local_port;
-      } else {
-        if ((msg->conn->pcb.udp->flags & UDP_FLAGS_CONNECTED) == 0) {
-          msg->err = ERR_CONN;
-        } else {
-          *(msg->msg.ad.port) = msg->conn->pcb.udp->remote_port;
-        }
-      }
-      break;
-#endif /* LWIP_UDP */
-#if LWIP_TCP
-    case NETCONN_TCP:
-      *(msg->msg.ad.port) = (msg->msg.ad.local?msg->conn->pcb.tcp->local_port:msg->conn->pcb.tcp->remote_port);
-      break;
-#endif /* LWIP_TCP */
-    default:
-      LWIP_ASSERT("invalid netconn_type", 0);
-      break;
-    }
-  } else {
-    msg->err = ERR_CONN;
-  }
-  TCPIP_APIMSG_ACK(msg);
-}
-
-/**
- * Close a TCP pcb contained in a netconn
- * Called from netconn_close
- *
- * @param msg the api_msg_msg pointing to the connection
- */
-void
-do_close(struct api_msg_msg *msg)
-{
-#if LWIP_TCP
-  /* @todo: abort running write/connect? */
-  if ((msg->conn->state != NETCONN_NONE) && (msg->conn->state != NETCONN_LISTEN)) {
-    /* this only happens for TCP netconns */
-    LWIP_ASSERT("msg->conn->type == NETCONN_TCP", msg->conn->type == NETCONN_TCP);
-    msg->err = ERR_INPROGRESS;
-  } else if ((msg->conn->pcb.tcp != NULL) && (msg->conn->type == NETCONN_TCP)) {
-    if ((msg->msg.sd.shut != NETCONN_SHUT_RDWR) && (msg->conn->state == NETCONN_LISTEN)) {
-      /* LISTEN doesn't support half shutdown */
-      msg->err = ERR_CONN;
-    } else {
-      if (msg->msg.sd.shut & NETCONN_SHUT_RD) {
-        /* Drain and delete mboxes */
-        netconn_drain(msg->conn);
-      }
-      LWIP_ASSERT("already writing or closing", msg->conn->current_msg == NULL &&
-        msg->conn->write_offset == 0);
-      msg->conn->state = NETCONN_CLOSE;
-      msg->conn->current_msg = msg;
-      do_close_internal(msg->conn);
-      /* for tcp netconns, do_close_internal ACKs the message */
-      return;
-    }
-  } else
-#endif /* LWIP_TCP */
-  {
-    msg->err = ERR_VAL;
-  }
-  sys_sem_signal(&msg->conn->op_completed);
-}
-
-#if LWIP_IGMP
-/**
- * Join multicast groups for UDP netconns.
- * Called from netconn_join_leave_group
- *
- * @param msg the api_msg_msg pointing to the connection
- */
-void
-do_join_leave_group(struct api_msg_msg *msg)
-{ 
-  if (ERR_IS_FATAL(msg->conn->last_err)) {
-    msg->err = msg->conn->last_err;
-  } else {
-    if (msg->conn->pcb.tcp != NULL) {
-      if (NETCONNTYPE_GROUP(msg->conn->type) == NETCONN_UDP) {
-#if LWIP_UDP
-        if (msg->msg.jl.join_or_leave == NETCONN_JOIN) {
-          msg->err = igmp_joingroup(msg->msg.jl.netif_addr, msg->msg.jl.multiaddr);
-        } else {
-          msg->err = igmp_leavegroup(msg->msg.jl.netif_addr, msg->msg.jl.multiaddr);
-        }
-#endif /* LWIP_UDP */
-#if (LWIP_TCP || LWIP_RAW)
-      } else {
-        msg->err = ERR_VAL;
-#endif /* (LWIP_TCP || LWIP_RAW) */
-      }
-    } else {
-      msg->err = ERR_CONN;
-    }
-  }
-  TCPIP_APIMSG_ACK(msg);
-}
-#endif /* LWIP_IGMP */
-
-#if LWIP_DNS
-/**
- * Callback function that is called when DNS name is resolved
- * (or on timeout). A waiting application thread is waked up by
- * signaling the semaphore.
- */
-static void
-do_dns_found(const char *name, ip_addr_t *ipaddr, void *arg)
-{
-  struct dns_api_msg *msg = (struct dns_api_msg*)arg;
-
-  LWIP_ASSERT("DNS response for wrong host name", strcmp(msg->name, name) == 0);
-  LWIP_UNUSED_ARG(name);
-
-  if (ipaddr == NULL) {
-    /* timeout or memory error */
-    *msg->err = ERR_VAL;
-  } else {
-    /* address was resolved */
-    *msg->err = ERR_OK;
-    *msg->addr = *ipaddr;
-  }
-  /* wake up the application task waiting in netconn_gethostbyname */
-  sys_sem_signal(msg->sem);
-}
-
-/**
- * Execute a DNS query
- * Called from netconn_gethostbyname
- *
- * @param arg the dns_api_msg pointing to the query
- */
-void
-do_gethostbyname(void *arg)
-{
-  struct dns_api_msg *msg = (struct dns_api_msg*)arg;
-
-  *msg->err = dns_gethostbyname(msg->name, msg->addr, do_dns_found, msg);
-  if (*msg->err != ERR_INPROGRESS) {
-    /* on error or immediate success, wake up the application
-     * task waiting in netconn_gethostbyname */
-    sys_sem_signal(msg->sem);
-  }
-}
-#endif /* LWIP_DNS */
-
-#endif /* LWIP_NETCONN */