www.pudn.com > lwip-1.3.0.rar > api_msg.c


/** 
 * @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  
 * 
 */ 
 
#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" 
 
/* 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, 
    struct ip_addr *addr) 
{ 
  struct pbuf *q; 
  struct netbuf *buf; 
  struct netconn *conn; 
#if LWIP_SO_RCVBUF 
  int recv_avail; 
#endif /* LWIP_SO_RCVBUF */ 
 
  LWIP_UNUSED_ARG(addr); 
  conn = arg; 
 
#if LWIP_SO_RCVBUF 
  SYS_ARCH_GET(conn->recv_avail, recv_avail); 
  if ((conn != NULL) && (conn->recvmbox != SYS_MBOX_NULL) && 
      ((recv_avail + (int)(p->tot_len)) <= conn->recv_bufsize)) { 
#else  /* LWIP_SO_RCVBUF */ 
  if ((conn != NULL) && (conn->recvmbox != SYS_MBOX_NULL)) { 
#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) { 
      buf = memp_malloc(MEMP_NETBUF); 
      if (buf == NULL) { 
        pbuf_free(q); 
        return 0; 
      } 
 
      buf->p = q; 
      buf->ptr = q; 
      buf->addr = &(((struct ip_hdr*)(q->payload))->src); 
      buf->port = pcb->protocol; 
 
      SYS_ARCH_INC(conn->recv_avail, q->tot_len); 
      /* Register event with callback */ 
      API_EVENT(conn, NETCONN_EVT_RCVPLUS, q->tot_len); 
      if (sys_mbox_trypost(conn->recvmbox, buf) != ERR_OK) { 
        netbuf_delete(buf); 
      } 
    } 
  } 
 
  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, 
   struct ip_addr *addr, u16_t port) 
{ 
  struct netbuf *buf; 
  struct netconn *conn; 
#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 = 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) || (conn->recvmbox == SYS_MBOX_NULL) || 
      ((recv_avail + (int)(p->tot_len)) > conn->recv_bufsize)) { 
#else  /* LWIP_SO_RCVBUF */ 
  if ((conn == NULL) || (conn->recvmbox == SYS_MBOX_NULL)) { 
#endif /* LWIP_SO_RCVBUF */ 
    pbuf_free(p); 
    return; 
  } 
 
  buf = memp_malloc(MEMP_NETBUF); 
  if (buf == NULL) { 
    pbuf_free(p); 
    return; 
  } else { 
    buf->p = p; 
    buf->ptr = p; 
    buf->addr = addr; 
    buf->port = port; 
  } 
 
  SYS_ARCH_INC(conn->recv_avail, p->tot_len); 
  /* Register event with callback */ 
  API_EVENT(conn, NETCONN_EVT_RCVPLUS, p->tot_len); 
  if (sys_mbox_trypost(conn->recvmbox, buf) != ERR_OK) { 
    netbuf_delete(buf); 
    return; 
  } 
} 
#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 = arg; 
  LWIP_ASSERT("recv_tcp: recv for wrong pcb!", conn->pcb.tcp == pcb); 
 
  if ((conn == NULL) || (conn->recvmbox == SYS_MBOX_NULL)) { 
    return ERR_VAL; 
  } 
 
  conn->err = err; 
  if (p != NULL) { 
    len = p->tot_len; 
    SYS_ARCH_INC(conn->recv_avail, len); 
  } else { 
    len = 0; 
  } 
  /* Register event with callback */ 
  API_EVENT(conn, NETCONN_EVT_RCVPLUS, len); 
  if (sys_mbox_trypost(conn->recvmbox, p) != ERR_OK) { 
    return ERR_MEM; 
  } 
 
  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 = 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); 
  } 
 
  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 = arg; 
 
  LWIP_UNUSED_ARG(pcb); 
  LWIP_ASSERT("conn != NULL", (conn != NULL)); 
 
  if (conn->state == NETCONN_WRITE) { 
    LWIP_ASSERT("conn->pcb.tcp != NULL", conn->pcb.tcp != NULL); 
    do_writemore(conn); 
  } else if (conn->state == NETCONN_CLOSE) { 
    do_close_internal(conn); 
  } 
 
  if (conn) { 
    if ((conn->pcb.tcp != NULL) && (tcp_sndbuf(conn->pcb.tcp) > TCP_SNDLOWAT)) { 
      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; 
 
  conn = arg; 
  LWIP_ASSERT("conn != NULL", (conn != NULL)); 
 
  conn->pcb.tcp = NULL; 
 
  conn->err = err; 
  if (conn->recvmbox != SYS_MBOX_NULL) { 
    /* Register event with callback */ 
    API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0); 
    sys_mbox_post(conn->recvmbox, NULL); 
  } 
  if (conn->op_completed != SYS_SEM_NULL && conn->state == NETCONN_CONNECT) { 
    conn->state = NETCONN_NONE; 
    sys_sem_signal(conn->op_completed); 
  } 
  if (conn->acceptmbox != SYS_MBOX_NULL) { 
    /* Register event with callback */ 
    API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0); 
    sys_mbox_post(conn->acceptmbox, NULL); 
  } 
  if ((conn->state == NETCONN_WRITE) || (conn->state == NETCONN_CLOSE)) { 
    /* calling do_writemore/do_close_internal is not necessary 
       since the pcb has already been deleted! */ 
    conn->state = NETCONN_NONE; 
    /* wake up the waiting task */ 
    sys_sem_signal(conn->op_completed); 
  } 
} 
 
/** 
 * 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; 
 
#if API_MSG_DEBUG 
#if TCP_DEBUG 
  tcp_debug_print_state(newpcb->state); 
#endif /* TCP_DEBUG */ 
#endif /* API_MSG_DEBUG */ 
  conn = (struct netconn *)arg; 
 
  LWIP_ERROR("accept_function: invalid conn->acceptmbox", 
             conn->acceptmbox != SYS_MBOX_NULL, 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); 
  newconn->err = err; 
  /* Register event with callback */ 
  API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0); 
 
  if (sys_mbox_trypost(conn->acceptmbox, newconn) != ERR_OK) { 
    /* When returning != ERR_OK, the connection is aborted in tcp_process(), 
       so do nothing here! */ 
    newconn->pcb.tcp = NULL; 
    netconn_free(newconn); 
    return ERR_MEM; 
  } 
  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 err_t 
pcb_new(struct api_msg_msg *msg) 
{ 
   msg->conn->err = ERR_OK; 
 
   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->conn->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->conn->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->conn->err = ERR_MEM; 
       break; 
     } 
     setup_tcp(msg->conn); 
     break; 
#endif /* LWIP_TCP */ 
   default: 
     /* Unsupported netconn type, e.g. protocol disabled */ 
     msg->conn->err = ERR_VAL; 
     break; 
   } 
 
  return msg->conn->err; 
} 
 
/** 
 * 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) 
{ 
   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 = memp_malloc(MEMP_NETCONN); 
  if (conn == NULL) { 
    return NULL; 
  } 
 
  conn->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 ((conn->op_completed = sys_sem_new(0)) == SYS_SEM_NULL) { 
    memp_free(MEMP_NETCONN, conn); 
    return NULL; 
  } 
  if ((conn->recvmbox = sys_mbox_new(size)) == SYS_MBOX_NULL) { 
    sys_sem_free(conn->op_completed); 
    memp_free(MEMP_NETCONN, conn); 
    return NULL; 
  } 
 
  conn->acceptmbox   = SYS_MBOX_NULL; 
  conn->state        = NETCONN_NONE; 
  /* initialize socket to -1 since 0 is a valid socket */ 
  conn->socket       = -1; 
  conn->callback     = callback; 
  conn->recv_avail   = 0; 
#if LWIP_SO_RCVTIMEO 
  conn->recv_timeout = 0; 
#endif /* LWIP_SO_RCVTIMEO */ 
#if LWIP_SO_RCVBUF 
  conn->recv_bufsize = INT_MAX; 
#endif /* LWIP_SO_RCVBUF */ 
  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) 
{ 
  void *mem; 
  LWIP_ASSERT("PCB must be deallocated outside this function", conn->pcb.tcp == NULL); 
 
  /* Drain the recvmbox. */ 
  if (conn->recvmbox != SYS_MBOX_NULL) { 
    while (sys_mbox_tryfetch(conn->recvmbox, &mem) != SYS_MBOX_EMPTY) { 
      if (conn->type == NETCONN_TCP) { 
        if(mem != NULL) { 
          pbuf_free((struct pbuf *)mem); 
        } 
      } else { 
        netbuf_delete((struct netbuf *)mem); 
      } 
    } 
    sys_mbox_free(conn->recvmbox); 
    conn->recvmbox = SYS_MBOX_NULL; 
  } 
 
  /* Drain the acceptmbox. */ 
  if (conn->acceptmbox != SYS_MBOX_NULL) { 
    while (sys_mbox_tryfetch(conn->acceptmbox, &mem) != SYS_MBOX_EMPTY) { 
      netconn_delete((struct netconn *)mem); 
    } 
    sys_mbox_free(conn->acceptmbox); 
    conn->acceptmbox = SYS_MBOX_NULL; 
  } 
 
  sys_sem_free(conn->op_completed); 
  conn->op_completed = SYS_SEM_NULL; 
 
  memp_free(MEMP_NETCONN, conn); 
} 
 
#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; 
 
  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)); 
 
  /* Set back some callback pointers */ 
  if (conn->pcb.tcp->state == LISTEN) { 
    tcp_arg(conn->pcb.tcp, NULL); 
    tcp_accept(conn->pcb.tcp, NULL); 
  } else { 
    tcp_recv(conn->pcb.tcp, NULL); 
  } 
  /* Try to close the connection */ 
  err = tcp_close(conn->pcb.tcp); 
  if (err == ERR_OK) { 
    /* Closing succeeded */ 
    conn->state = NETCONN_NONE; 
    /* Set back some callback pointers as conn is going away */ 
    tcp_err(conn->pcb.tcp, NULL); 
    tcp_poll(conn->pcb.tcp, NULL, 4); 
    tcp_sent(conn->pcb.tcp, NULL); 
    tcp_recv(conn->pcb.tcp, NULL); 
    tcp_arg(conn->pcb.tcp, NULL); 
    conn->pcb.tcp = NULL; 
    conn->err = ERR_OK; 
    /* Trigger select() in socket layer. This send should something else so the 
       errorfd is set, not the read and write fd! */ 
    API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0); 
    API_EVENT(conn, NETCONN_EVT_SENDPLUS, 0); 
    /* wake up the application task */ 
    sys_sem_signal(conn->op_completed); 
  } 
  /* 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) 
{ 
  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: 
      msg->conn->state = NETCONN_CLOSE; 
      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; 
    } 
  } 
  /* tcp netconns don't come here! */ 
 
  /* Trigger select() in socket layer. This send should something else so the 
     errorfd is set, not the read and write fd! */ 
  API_EVENT(msg->conn, NETCONN_EVT_RCVPLUS, 0); 
  API_EVENT(msg->conn, NETCONN_EVT_SENDPLUS, 0); 
 
  if (msg->conn->op_completed != SYS_SEM_NULL) { 
    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->err)) { 
    if (msg->conn->pcb.tcp != NULL) { 
      switch (NETCONNTYPE_GROUP(msg->conn->type)) { 
#if LWIP_RAW 
      case NETCONN_RAW: 
        msg->conn->err = raw_bind(msg->conn->pcb.raw, msg->msg.bc.ipaddr); 
        break; 
#endif /* LWIP_RAW */ 
#if LWIP_UDP 
      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); 
        break; 
#endif /* LWIP_TCP */ 
      default: 
        break; 
      } 
    } else { 
      /* msg->conn->pcb is NULL */ 
      msg->conn->err = ERR_VAL; 
    } 
  } 
  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; 
 
  LWIP_UNUSED_ARG(pcb); 
 
  conn = arg; 
 
  if (conn == NULL) { 
    return ERR_VAL; 
  } 
 
  conn->err = err; 
  if ((conn->type == NETCONN_TCP) && (err == ERR_OK)) { 
    setup_tcp(conn); 
  } 
  conn->state = NETCONN_NONE; 
  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) { 
    sys_sem_signal(msg->conn->op_completed); 
    return; 
  } 
 
  switch (NETCONNTYPE_GROUP(msg->conn->type)) { 
#if LWIP_RAW 
  case NETCONN_RAW: 
    msg->conn->err = raw_connect(msg->conn->pcb.raw, msg->msg.bc.ipaddr); 
    sys_sem_signal(msg->conn->op_completed); 
    break; 
#endif /* LWIP_RAW */ 
#if LWIP_UDP 
  case NETCONN_UDP: 
    msg->conn->err = udp_connect(msg->conn->pcb.udp, msg->msg.bc.ipaddr, msg->msg.bc.port); 
    sys_sem_signal(msg->conn->op_completed); 
    break; 
#endif /* LWIP_UDP */ 
#if LWIP_TCP 
  case NETCONN_TCP: 
    msg->conn->state = NETCONN_CONNECT; 
    setup_tcp(msg->conn); 
    msg->conn->err = tcp_connect(msg->conn->pcb.tcp, msg->msg.bc.ipaddr, msg->msg.bc.port, 
                                 do_connected); 
    /* sys_sem_signal() is called from do_connected (or err_tcp()), 
     * when the connection is established! */ 
    break; 
#endif /* LWIP_TCP */ 
  default: 
    break; 
  } 
} 
 
/** 
 * 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); 
  } 
#endif /* LWIP_UDP */ 
  TCPIP_APIMSG_ACK(msg); 
} 
 
/** 
 * 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 LWIP_TCP 
  if (!ERR_IS_FATAL(msg->conn->err)) { 
    if (msg->conn->pcb.tcp != NULL) { 
      if (msg->conn->type == NETCONN_TCP) { 
        if (msg->conn->pcb.tcp->state == CLOSED) { 
#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) { 
            msg->conn->err = ERR_MEM; 
          } else { 
            /* delete the recvmbox and allocate the acceptmbox */ 
            if (msg->conn->recvmbox != SYS_MBOX_NULL) { 
              /** @todo: should we drain the recvmbox here? */ 
              sys_mbox_free(msg->conn->recvmbox); 
              msg->conn->recvmbox = SYS_MBOX_NULL; 
            } 
            if (msg->conn->acceptmbox == SYS_MBOX_NULL) { 
              if ((msg->conn->acceptmbox = sys_mbox_new(DEFAULT_ACCEPTMBOX_SIZE)) == SYS_MBOX_NULL) { 
                msg->conn->err = ERR_MEM; 
              } 
            } 
            if (msg->conn->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 { 
          msg->conn->err = ERR_CONN; 
        } 
      } 
    } 
  } 
#endif /* LWIP_TCP */ 
  TCPIP_APIMSG_ACK(msg); 
} 
 
/** 
 * 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->err)) { 
    if (msg->conn->pcb.tcp != NULL) { 
      switch (NETCONNTYPE_GROUP(msg->conn->type)) { 
#if LWIP_RAW 
      case NETCONN_RAW: 
        if (msg->msg.b->addr == NULL) { 
          msg->conn->err = raw_send(msg->conn->pcb.raw, msg->msg.b->p); 
        } else { 
          msg->conn->err = raw_sendto(msg->conn->pcb.raw, msg->msg.b->p, msg->msg.b->addr); 
        } 
        break; 
#endif 
#if LWIP_UDP 
      case NETCONN_UDP: 
        if (msg->msg.b->addr == NULL) { 
          msg->conn->err = udp_send(msg->conn->pcb.udp, msg->msg.b->p); 
        } else { 
          msg->conn->err = udp_sendto(msg->conn->pcb.udp, msg->msg.b->p, msg->msg.b->addr, msg->msg.b->port); 
        } 
        break; 
#endif /* LWIP_UDP */ 
      default: 
        break; 
      } 
    } 
  } 
  TCPIP_APIMSG_ACK(msg); 
} 
 
/** 
 * Recv some data from a RAW or UDP 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) 
{ 
#if LWIP_TCP 
  if (!ERR_IS_FATAL(msg->conn->err)) { 
    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 */ 
        { 
          tcp_recved(msg->conn->pcb.tcp, msg->msg.r.len); 
        } 
      } 
    } 
  } 
#endif /* LWIP_TCP */ 
  TCPIP_APIMSG_ACK(msg); 
} 
 
#if LWIP_TCP 
/** 
 * 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; 
  void *dataptr; 
  u16_t len, available; 
  u8_t write_finished = 0; 
 
  LWIP_ASSERT("conn->state == NETCONN_WRITE", (conn->state == NETCONN_WRITE)); 
 
  dataptr = (u8_t*)conn->write_msg->msg.w.dataptr + conn->write_offset; 
  if ((conn->write_msg->msg.w.len - conn->write_offset > 0xffff)) { /* max_u16_t */ 
    len = 0xffff; 
#if LWIP_TCPIP_CORE_LOCKING 
    conn->write_delayed = 1; 
#endif 
  } else { 
    len = conn->write_msg->msg.w.len - conn->write_offset; 
  } 
  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->write_delayed = 1; 
#endif 
  } 
 
  err = tcp_write(conn->pcb.tcp, dataptr, len, conn->write_msg->msg.w.apiflags); 
  LWIP_ASSERT("do_writemore: invalid length!", ((conn->write_offset + len) <= conn->write_msg->msg.w.len)); 
  if (err == ERR_OK) { 
    conn->write_offset += len; 
    if (conn->write_offset == conn->write_msg->msg.w.len) { 
      /* everything was written */ 
      write_finished = 1; 
      conn->write_msg = NULL; 
      conn->write_offset = 0; 
    } 
    err = tcp_output_nagle(conn->pcb.tcp); 
    conn->err = err; 
    if ((err == ERR_OK) && (tcp_sndbuf(conn->pcb.tcp) <= TCP_SNDLOWAT)) { 
      API_EVENT(conn, NETCONN_EVT_SENDMINUS, len); 
    } 
  } 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_enqueue returned ERR_MEM, try tcp_output anyway */ 
    err = tcp_output(conn->pcb.tcp); 
 
#if LWIP_TCPIP_CORE_LOCKING 
    conn->write_delayed = 1; 
#endif 
  } else { 
    /* On errors != ERR_MEM, we don't try writing any more but return 
       the error to the application thread. */ 
    conn->err = err; 
    write_finished = 1; 
  } 
 
  if (write_finished) { 
    /* everything was written: set back connection state 
       and back to application task */ 
    conn->state = NETCONN_NONE; 
#if LWIP_TCPIP_CORE_LOCKING 
    if (conn->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->err)) { 
    if ((msg->conn->pcb.tcp != NULL) && (msg->conn->type == NETCONN_TCP)) { 
#if LWIP_TCP 
      msg->conn->state = NETCONN_WRITE; 
      /* set all the variables used by do_writemore */ 
      msg->conn->write_msg = msg; 
      msg->conn->write_offset = 0; 
#if LWIP_TCPIP_CORE_LOCKING 
      msg->conn->write_delayed = 0; 
      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 
      do_writemore(msg->conn); 
#endif 
      /* for both cases: if do_writemore was called, don't ACK the APIMSG! */ 
      return; 
#endif /* LWIP_TCP */ 
#if (LWIP_UDP || LWIP_RAW) 
    } else { 
      msg->conn->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); 
     
    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->conn->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->conn->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 */ 
    } 
  } else { 
    msg->conn->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 
  if ((msg->conn->pcb.tcp != NULL) && (msg->conn->type == NETCONN_TCP)) { 
      msg->conn->state = NETCONN_CLOSE; 
      do_close_internal(msg->conn); 
      /* for tcp netconns, do_close_internal ACKs the message */ 
  } else 
#endif /* LWIP_TCP */ 
  { 
    msg->conn->err = ERR_VAL; 
    TCPIP_APIMSG_ACK(msg); 
  } 
} 
 
#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->err)) { 
    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->conn->err = igmp_joingroup(msg->msg.jl.interface, msg->msg.jl.multiaddr); 
        } else { 
          msg->conn->err = igmp_leavegroup(msg->msg.jl.interface, msg->msg.jl.multiaddr); 
        } 
#endif /* LWIP_UDP */ 
#if (LWIP_TCP || LWIP_RAW) 
      } else { 
        msg->conn->err = ERR_VAL; 
#endif /* (LWIP_TCP || LWIP_RAW) */ 
      } 
    } 
  } 
  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, struct ip_addr *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); 
 
  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 */