text: /**
   * @file
   * Sequential API Main thread 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 !NO_SYS /* don't build if not configured for use in lwipopts.h */
  
  #include "lwip/lwip_sys.h"
  #include "lwip/memp.h"
  #include "lwip/mem.h"
  #include "lwip/pbuf.h"
  #include "lwip/tcpip.h"
  #include "lwip/init.h"
  #include "netif/etharp.h"
  #include "netif/ppp_oe.h"
  
  /* global variables */
  static tcpip_init_done_fn tcpip_init_done;
  static void *tcpip_init_done_arg;
  sys_mbox_t mbox;
  
  #if LWIP_TCPIP_CORE_LOCKING
  /** The global semaphore to lock the stack. */
  sys_mutex_t lock_tcpip_core;
  #endif /* LWIP_TCPIP_CORE_LOCKING */
  
  
  /**
   * The main lwIP thread. This thread has exclusive access to lwIP core functions
   * (unless access to them is not locked). Other threads communicate with this
   * thread using message boxes.
   *
   * It also starts all the timers to make sure they are running in the right
   * thread context.
   *
   * @param arg unused argument
   */
  static void
  tcpip_thread(void *arg)
  {
    struct tcpip_msg *msg;
    LWIP_UNUSED_ARG(arg);
  
    if (tcpip_init_done != NULL) {
      tcpip_init_done(tcpip_init_done_arg);
    }
  
    LOCK_TCPIP_CORE();
    while (1) {                          /* MAIN Loop */
      UNLOCK_TCPIP_CORE();
      LWIP_TCPIP_THREAD_ALIVE();
      /* wait for a message, timeouts are processed while waiting */
      sys_timeouts_mbox_fetch(&mbox, (void **)&msg);
      LOCK_TCPIP_CORE();
      switch (msg->type) {
  #if LWIP_NETCONN
      case TCPIP_MSG_API:
        LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: API message %p\n", (void *)msg));
        msg->msg.apimsg->function(&(msg->msg.apimsg->msg));
        break;
  #endif /* LWIP_NETCONN */
  
  #if !LWIP_TCPIP_CORE_LOCKING_INPUT
      case TCPIP_MSG_INPKT:
        LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: PACKET %p\n", (void *)msg));
  #if LWIP_ETHERNET
        if (msg->msg.inp.netif->flags & (NETIF_FLAG_ETHARP | NETIF_FLAG_ETHERNET)) {
          ethernet_input(msg->msg.inp.p, msg->msg.inp.netif);
        } else
  #endif /* LWIP_ETHERNET */
        {
          ip_input(msg->msg.inp.p, msg->msg.inp.netif);
        }
        memp_free(MEMP_TCPIP_MSG_INPKT, msg);
        break;
  #endif /* LWIP_TCPIP_CORE_LOCKING_INPUT */
  
  #if LWIP_NETIF_API
      case TCPIP_MSG_NETIFAPI:
        LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: Netif API message %p\n", (void *)msg));
        msg->msg.netifapimsg->function(&(msg->msg.netifapimsg->msg));
        break;
  #endif /* LWIP_NETIF_API */
  
  #if LWIP_TCPIP_TIMEOUT
      case TCPIP_MSG_TIMEOUT:
        LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: TIMEOUT %p\n", (void *)msg));
        sys_timeout(msg->msg.tmo.msecs, msg->msg.tmo.h, msg->msg.tmo.arg);
        memp_free(MEMP_TCPIP_MSG_API, msg);
        break;
      case TCPIP_MSG_UNTIMEOUT:
        LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: UNTIMEOUT %p\n", (void *)msg));
        sys_untimeout(msg->msg.tmo.h, msg->msg.tmo.arg);
        memp_free(MEMP_TCPIP_MSG_API, msg);
        break;
  #endif /* LWIP_TCPIP_TIMEOUT */
  
      case TCPIP_MSG_CALLBACK:
        LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: CALLBACK %p\n", (void *)msg));
        msg->msg.cb.function(msg->msg.cb.ctx);
        memp_free(MEMP_TCPIP_MSG_API, msg);
        break;
  
      case TCPIP_MSG_CALLBACK_STATIC:
        LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: CALLBACK_STATIC %p\n", (void *)msg));
        msg->msg.cb.function(msg->msg.cb.ctx);
        break;
  
      default:
        LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: invalid message: %d\n", msg->type));
        LWIP_ASSERT("tcpip_thread: invalid message", 0);
        break;
      }
    }
  }
  
  /**
   * Pass a received packet to tcpip_thread for input processing
   *
   * @param p the received packet, p->payload pointing to the Ethernet header or
   *          to an IP header (if inp doesn't have NETIF_FLAG_ETHARP or
   *          NETIF_FLAG_ETHERNET flags)
   * @param inp the network interface on which the packet was received
   */
  err_t
  tcpip_input(struct pbuf *p, struct netif *inp)
  {
  #if LWIP_TCPIP_CORE_LOCKING_INPUT
    err_t ret;
    LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_input: PACKET %p/%p\n", (void *)p, (void *)inp));
    LOCK_TCPIP_CORE();
  #if LWIP_ETHERNET
    if (inp->flags & (NETIF_FLAG_ETHARP | NETIF_FLAG_ETHERNET)) {
      ret = ethernet_input(p, inp);
    } else
  #endif /* LWIP_ETHERNET */
    {
      ret = ip_input(p, inp);
    }
    UNLOCK_TCPIP_CORE();
    return ret;
  #else /* LWIP_TCPIP_CORE_LOCKING_INPUT */
    struct tcpip_msg *msg;
  
    if (!sys_mbox_valid(&mbox)) {
      return ERR_VAL;
    }
    msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_INPKT);
    if (msg == NULL) {
      return ERR_MEM;
    }
  
    msg->type = TCPIP_MSG_INPKT;
    msg->msg.inp.p = p;
    msg->msg.inp.netif = inp;
    if (sys_mbox_trypost(&mbox, msg) != ERR_OK) {
      memp_free(MEMP_TCPIP_MSG_INPKT, msg);
      return ERR_MEM;
    }
    return ERR_OK;
  #endif /* LWIP_TCPIP_CORE_LOCKING_INPUT */
  }
  
  /**
   * Call a specific function in the thread context of
   * tcpip_thread for easy access synchronization.
   * A function called in that way may access lwIP core code
   * without fearing concurrent access.
   *
   * @param f the function to call
   * @param ctx parameter passed to f
   * @param block 1 to block until the request is posted, 0 to non-blocking mode
   * @return ERR_OK if the function was called, another err_t if not
   */
  err_t
  tcpip_callback_with_block(tcpip_callback_fn function, void *ctx, u8_t block)
  {
    struct tcpip_msg *msg;
  
    if (sys_mbox_valid(&mbox)) {
      msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_API);
      if (msg == NULL) {
        return ERR_MEM;
      }
  
      msg->type = TCPIP_MSG_CALLBACK;
      msg->msg.cb.function = function;
      msg->msg.cb.ctx = ctx;
      if (block) {
        sys_mbox_post(&mbox, msg);
      } else {
        if (sys_mbox_trypost(&mbox, msg) != ERR_OK) {
          memp_free(MEMP_TCPIP_MSG_API, msg);
          return ERR_MEM;
        }
      }
      return ERR_OK;
    }
    return ERR_VAL;
  }
  
  #if LWIP_TCPIP_TIMEOUT
  /**
   * call sys_timeout in tcpip_thread
   *
   * @param msec time in milliseconds for timeout
   * @param h function to be called on timeout
   * @param arg argument to pass to timeout function h
   * @return ERR_MEM on memory error, ERR_OK otherwise
   */
  err_t
  tcpip_timeout(u32_t msecs, sys_timeout_handler h, void *arg)
  {
    struct tcpip_msg *msg;
  
    if (sys_mbox_valid(&mbox)) {
      msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_API);
      if (msg == NULL) {
        return ERR_MEM;
      }
  
      msg->type = TCPIP_MSG_TIMEOUT;
      msg->msg.tmo.msecs = msecs;
      msg->msg.tmo.h = h;
      msg->msg.tmo.arg = arg;
      sys_mbox_post(&mbox, msg);
      return ERR_OK;
    }
    return ERR_VAL;
  }
  
  /**
   * call sys_untimeout in tcpip_thread
   *
   * @param msec time in milliseconds for timeout
   * @param h function to be called on timeout
   * @param arg argument to pass to timeout function h
   * @return ERR_MEM on memory error, ERR_OK otherwise
   */
  err_t
  tcpip_untimeout(sys_timeout_handler h, void *arg)
  {
    struct tcpip_msg *msg;
  
    if (sys_mbox_valid(&mbox)) {
      msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_API);
      if (msg == NULL) {
        return ERR_MEM;
      }
  
      msg->type = TCPIP_MSG_UNTIMEOUT;
      msg->msg.tmo.h = h;
      msg->msg.tmo.arg = arg;
      sys_mbox_post(&mbox, msg);
      return ERR_OK;
    }
    return ERR_VAL;
  }
  #endif /* LWIP_TCPIP_TIMEOUT */
  
  #if LWIP_NETCONN
  /**
   * Call the lower part of a netconn_* function
   * This function is then running in the thread context
   * of tcpip_thread and has exclusive access to lwIP core code.
   *
   * @param apimsg a struct containing the function to call and its parameters
   * @return ERR_OK if the function was called, another err_t if not
   */
  err_t
  tcpip_apimsg(struct api_msg *apimsg)
  {
    struct tcpip_msg msg;
  #ifdef LWIP_DEBUG
    /* catch functions that don't set err */
    apimsg->msg.err = ERR_VAL;
  #endif
    
    if (sys_mbox_valid(&mbox)) {
      msg.type = TCPIP_MSG_API;
      msg.msg.apimsg = apimsg;
      sys_mbox_post(&mbox, &msg);
      sys_arch_sem_wait(&apimsg->msg.conn->op_completed, 0);
      return apimsg->msg.err;
    }
    return ERR_VAL;
  }
  
  #if LWIP_TCPIP_CORE_LOCKING
  /**
   * Call the lower part of a netconn_* function
   * This function has exclusive access to lwIP core code by locking it
   * before the function is called.
   *
   * @param apimsg a struct containing the function to call and its parameters
   * @return ERR_OK (only for compatibility fo tcpip_apimsg())
   */
  err_t
  tcpip_apimsg_lock(struct api_msg *apimsg)
  {
  #ifdef LWIP_DEBUG
    /* catch functions that don't set err */
    apimsg->msg.err = ERR_VAL;
  #endif
  
    LOCK_TCPIP_CORE();
    apimsg->function(&(apimsg->msg));
    UNLOCK_TCPIP_CORE();
    return apimsg->msg.err;
  
  }
  #endif /* LWIP_TCPIP_CORE_LOCKING */
  #endif /* LWIP_NETCONN */
  
  #if LWIP_NETIF_API
  #if !LWIP_TCPIP_CORE_LOCKING
  /**
   * Much like tcpip_apimsg, but calls the lower part of a netifapi_*
   * function.
   *
   * @param netifapimsg a struct containing the function to call and its parameters
   * @return error code given back by the function that was called
   */
  err_t
  tcpip_netifapi(struct netifapi_msg* netifapimsg)
  {
    struct tcpip_msg msg;
    
    if (sys_mbox_valid(&mbox)) {
      err_t err = sys_sem_new(&netifapimsg->msg.sem, 0);
      if (err != ERR_OK) {
        netifapimsg->msg.err = err;
        return err;
      }
      
      msg.type = TCPIP_MSG_NETIFAPI;
      msg.msg.netifapimsg = netifapimsg;
      sys_mbox_post(&mbox, &msg);
      sys_sem_wait(&netifapimsg->msg.sem);
      sys_sem_free(&netifapimsg->msg.sem);
      return netifapimsg->msg.err;
    }
    return ERR_VAL;
  }
  #else /* !LWIP_TCPIP_CORE_LOCKING */
  /**
   * Call the lower part of a netifapi_* function
   * This function has exclusive access to lwIP core code by locking it
   * before the function is called.
   *
   * @param netifapimsg a struct containing the function to call and its parameters
   * @return ERR_OK (only for compatibility fo tcpip_netifapi())
   */
  err_t
  tcpip_netifapi_lock(struct netifapi_msg* netifapimsg)
  {
    LOCK_TCPIP_CORE();  
    netifapimsg->function(&(netifapimsg->msg));
    UNLOCK_TCPIP_CORE();
    return netifapimsg->msg.err;
  }
  #endif /* !LWIP_TCPIP_CORE_LOCKING */
  #endif /* LWIP_NETIF_API */
  
  /**
   * Allocate a structure for a static callback message and initialize it.
   * This is intended to be used to send "static" messages from interrupt context.
   *
   * @param function the function to call
   * @param ctx parameter passed to function
   * @return a struct pointer to pass to tcpip_trycallback().
   */
  struct tcpip_callback_msg* tcpip_callbackmsg_new(tcpip_callback_fn function, void *ctx)
  {
    struct tcpip_msg *msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_API);
    if (msg == NULL) {
      return NULL;
    }
    msg->type = TCPIP_MSG_CALLBACK_STATIC;
    msg->msg.cb.function = function;
    msg->msg.cb.ctx = ctx;
    return (struct tcpip_callback_msg*)msg;
  }
  
  /**
   * Free a callback message allocated by tcpip_callbackmsg_new().
   *
   * @param msg the message to free
   */
  void tcpip_callbackmsg_delete(struct tcpip_callback_msg* msg)
  {
    memp_free(MEMP_TCPIP_MSG_API, msg);
  }
  
  /**
   * Try to post a callback-message to the tcpip_thread mbox
   * This is intended to be used to send "static" messages from interrupt context.
   *
   * @param msg pointer to the message to post
   * @return sys_mbox_trypost() return code
   */
  err_t
  tcpip_trycallback(struct tcpip_callback_msg* msg)
  {
    if (!sys_mbox_valid(&mbox)) {
      return ERR_VAL;
    }
    return sys_mbox_trypost(&mbox, msg);
  }
  
  /**
   * Initialize this module:
   * - initialize all sub modules
   * - start the tcpip_thread
   *
   * @param initfunc a function to call when tcpip_thread is running and finished initializing
   * @param arg argument to pass to initfunc
   */
  void
  tcpip_init(tcpip_init_done_fn initfunc, void *arg)
  {
    lwip_init();
  
    tcpip_init_done = initfunc;
    tcpip_init_done_arg = arg;
    if(sys_mbox_new(&mbox, TCPIP_MBOX_SIZE) != ERR_OK) {
      LWIP_ASSERT("failed to create tcpip_thread mbox", 0);
    }
  #if LWIP_TCPIP_CORE_LOCKING
    if(sys_mutex_new(&lock_tcpip_core) != ERR_OK) {
      LWIP_ASSERT("failed to create lock_tcpip_core", 0);
    }
  #endif /* LWIP_TCPIP_CORE_LOCKING */
  
    sys_thread_new(TCPIP_THREAD_NAME, tcpip_thread, NULL, TCPIP_THREAD_STACKSIZE, TCPIP_THREAD_PRIO);
  }
  
  /**
   * Simple callback function used with tcpip_callback to free a pbuf
   * (pbuf_free has a wrong signature for tcpip_callback)
   *
   * @param p The pbuf (chain) to be dereferenced.
   */
  static void
  pbuf_free_int(void *p)
  {
    struct pbuf *q = (struct pbuf *)p;
    pbuf_free(q);
  }
  
  /**
   * A simple wrapper function that allows you to free a pbuf from interrupt context.
   *
   * @param p The pbuf (chain) to be dereferenced.
   * @return ERR_OK if callback could be enqueued, an err_t if not
   */
  err_t
  pbuf_free_callback(struct pbuf *p)
  {
    return tcpip_callback_with_block(pbuf_free_int, p, 0);
  }
  
  /**
   * A simple wrapper function that allows you to free heap memory from
   * interrupt context.
   *
   * @param m the heap memory to free
   * @return ERR_OK if callback could be enqueued, an err_t if not
   */
  err_t
  mem_free_callback(void *m)
  {
    return tcpip_callback_with_block(mem_free, m, 0);
  }
  
  #endif /* !NO_SYS */
  