text: /**
   * @file
   *
   * AutoIP Automatic LinkLocal IP Configuration
   */
  
  /*
   *
   * Copyright (c) 2007 Dominik Spies <kontakt@dspies.de>
   * 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.
   *
   * Author: Dominik Spies <kontakt@dspies.de>
   *
   * This is a AutoIP implementation for the lwIP TCP/IP stack. It aims to conform
   * with RFC 3927.
   *
   */
  
  #ifndef LWIP_HDR_AUTOIP_H
  #define LWIP_HDR_AUTOIP_H
  
  #include "lwip/opt.h"
  
  #if LWIP_IPV4 && LWIP_AUTOIP /* don't build if not configured for use in lwipopts.h */
  
  #include "lwip/netif.h"
  /* #include "lwip/udp.h" */
  #include "lwip/etharp.h"
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /** AutoIP Timing */
  #define AUTOIP_TMR_INTERVAL      100
  #define AUTOIP_TICKS_PER_SECOND (1000 / AUTOIP_TMR_INTERVAL)
  
  /** AutoIP state information per netif */
  struct autoip
  {
    /** the currently selected, probed, announced or used LL IP-Address */
    ip4_addr_t llipaddr;
    /** current AutoIP state machine state */
    u8_t state;
    /** sent number of probes or announces, dependent on state */
    u8_t sent_num;
    /** ticks to wait, tick is AUTOIP_TMR_INTERVAL long */
    u16_t ttw;
    /** ticks until a conflict can be solved by defending */
    u8_t lastconflict;
    /** total number of probed/used Link Local IP-Addresses */
    u8_t tried_llipaddr;
  };
  
  
  void autoip_set_struct(struct netif *netif, struct autoip *autoip);
  /** Remove a struct autoip previously set to the netif using autoip_set_struct() */
  #define autoip_remove_struct(netif) do { (netif)->autoip = NULL; } while (0)
  err_t autoip_start(struct netif *netif);
  err_t autoip_stop(struct netif *netif);
  void autoip_arp_reply(struct netif *netif, struct etharp_hdr *hdr);
  u8_t autoip_tmr(void);
  void autoip_network_changed(struct netif *netif);
  u8_t autoip_supplied_address(const struct netif *netif);
  
  /* for lwIP internal use by ip4.c */
  u8_t autoip_accept_packet(struct netif *netif, const ip4_addr_t *addr);
  
  #define netif_autoip_data(netif) ((struct autoip*)netif_get_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_AUTOIP))
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* LWIP_IPV4 && LWIP_AUTOIP */
  
  #endif /* LWIP_HDR_AUTOIP_H */
  