Diff: lwip/netif/etharp.c

Revision:

1:9d93f4dc2f46

Parent:

0:8b387bed54c2

--- a/lwip/netif/etharp.c	Mon Jan 10 21:03:11 2011 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1285 +0,0 @@
-/**
- * @file
- * Address Resolution Protocol module for IP over Ethernet
- *
- * Functionally, ARP is divided into two parts. The first maps an IP address
- * to a physical address when sending a packet, and the second part answers
- * requests from other machines for our physical address.
- *
- * This implementation complies with RFC 826 (Ethernet ARP). It supports
- * Gratuitious ARP from RFC3220 (IP Mobility Support for IPv4) section 4.6
- * if an interface calls etharp_gratuitous(our_netif) upon address change.
- */
-
-/*
- * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
- * Copyright (c) 2003-2004 Leon Woestenberg <leon.woestenberg@axon.tv>
- * Copyright (c) 2003-2004 Axon Digital Design B.V., The Netherlands.
- * 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.
- *
- */
- 
-#include "lwip/opt.h"
-
-#if LWIP_ARP || LWIP_ETHERNET
-
-#include "lwip/ip_addr.h"
-#include "lwip/def.h"
-#include "lwip/ip.h"
-#include "lwip/stats.h"
-#include "lwip/snmp.h"
-#include "lwip/dhcp.h"
-#include "lwip/autoip.h"
-#include "netif/etharp.h"
-
-#if PPPOE_SUPPORT
-#include "netif/ppp_oe.h"
-#endif /* PPPOE_SUPPORT */
-
-#include <string.h>
-
-const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};
-const struct eth_addr ethzero = {{0,0,0,0,0,0}};
-
-#if LWIP_ARP /* don't build if not configured for use in lwipopts.h */
-
-/** the time an ARP entry stays valid after its last update,
- *  for ARP_TMR_INTERVAL = 5000, this is
- *  (240 * 5) seconds = 20 minutes.
- */
-#define ARP_MAXAGE 240
-/** the time an ARP entry stays pending after first request,
- *  for ARP_TMR_INTERVAL = 5000, this is
- *  (2 * 5) seconds = 10 seconds.
- * 
- *  @internal Keep this number at least 2, otherwise it might
- *  run out instantly if the timeout occurs directly after a request.
- */
-#define ARP_MAXPENDING 2
-
-#define HWTYPE_ETHERNET 1
-
-enum etharp_state {
-  ETHARP_STATE_EMPTY = 0,
-  ETHARP_STATE_PENDING,
-  ETHARP_STATE_STABLE
-};
-
-struct etharp_entry {
-#if ARP_QUEUEING
-  /** Pointer to queue of pending outgoing packets on this ARP entry. */
-  struct etharp_q_entry *q;
-#endif /* ARP_QUEUEING */
-  ip_addr_t ipaddr;
-  struct eth_addr ethaddr;
-#if LWIP_SNMP
-  struct netif *netif;
-#endif /* LWIP_SNMP */
-  u8_t state;
-  u8_t ctime;
-#if ETHARP_SUPPORT_STATIC_ENTRIES
-  u8_t static_entry;
-#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
-};
-
-static struct etharp_entry arp_table[ARP_TABLE_SIZE];
-
-#if !LWIP_NETIF_HWADDRHINT
-static u8_t etharp_cached_entry;
-#endif /* !LWIP_NETIF_HWADDRHINT */
-
-/** Try hard to create a new entry - we want the IP address to appear in
-    the cache (even if this means removing an active entry or so). */
-#define ETHARP_FLAG_TRY_HARD     1
-#define ETHARP_FLAG_FIND_ONLY    2
-#define ETHARP_FLAG_STATIC_ENTRY 4
-
-#if LWIP_NETIF_HWADDRHINT
-#define ETHARP_SET_HINT(netif, hint)  if (((netif) != NULL) && ((netif)->addr_hint != NULL))  \
-                                      *((netif)->addr_hint) = (hint);
-#else /* LWIP_NETIF_HWADDRHINT */
-#define ETHARP_SET_HINT(netif, hint)  (etharp_cached_entry = (hint))
-#endif /* LWIP_NETIF_HWADDRHINT */
-
-static err_t update_arp_entry(struct netif *netif, ip_addr_t *ipaddr, struct eth_addr *ethaddr, u8_t flags);
-
-
-/* Some checks, instead of etharp_init(): */
-#if (LWIP_ARP && (ARP_TABLE_SIZE > 0x7f))
-  #error "ARP_TABLE_SIZE must fit in an s8_t, you have to reduce it in your lwipopts.h"
-#endif
-
-
-#if ARP_QUEUEING
-/**
- * Free a complete queue of etharp entries
- *
- * @param q a qeueue of etharp_q_entry's to free
- */
-static void
-free_etharp_q(struct etharp_q_entry *q)
-{
-  struct etharp_q_entry *r;
-  LWIP_ASSERT("q != NULL", q != NULL);
-  LWIP_ASSERT("q->p != NULL", q->p != NULL);
-  while (q) {
-    r = q;
-    q = q->next;
-    LWIP_ASSERT("r->p != NULL", (r->p != NULL));
-    pbuf_free(r->p);
-    memp_free(MEMP_ARP_QUEUE, r);
-  }
-}
-#endif /* ARP_QUEUEING */
-
-/** Clean up ARP table entries */
-static void
-free_entry(int i)
-{
-  /* remove from SNMP ARP index tree */
-  snmp_delete_arpidx_tree(arp_table[i].netif, &arp_table[i].ipaddr);
-#if ARP_QUEUEING
-  /* and empty packet queue */
-  if (arp_table[i].q != NULL) {
-    /* remove all queued packets */
-    LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer: freeing entry %"U16_F", packet queue %p.\n", (u16_t)i, (void *)(arp_table[i].q)));
-    free_etharp_q(arp_table[i].q);
-    arp_table[i].q = NULL;
-  }
-#endif /* ARP_QUEUEING */
-  /* recycle entry for re-use */      
-  arp_table[i].state = ETHARP_STATE_EMPTY;
-#if ETHARP_SUPPORT_STATIC_ENTRIES
-  arp_table[i].static_entry = 0;
-#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
-#ifdef LWIP_DEBUG
-  /* for debugging, clean out the complete entry */
-  arp_table[i].ctime = 0;
-#if LWIP_SNMP
-  arp_table[i].netif = NULL;
-#endif /* LWIP_SNMP */
-  ip_addr_set_zero(&arp_table[i].ipaddr);
-  arp_table[i].ethaddr = ethzero;
-#endif /* LWIP_DEBUG */
-}
-
-/**
- * Clears expired entries in the ARP table.
- *
- * This function should be called every ETHARP_TMR_INTERVAL milliseconds (5 seconds),
- * in order to expire entries in the ARP table.
- */
-void
-etharp_tmr(void)
-{
-  u8_t i;
-
-  LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer\n"));
-  /* remove expired entries from the ARP table */
-  for (i = 0; i < ARP_TABLE_SIZE; ++i) {
-    u8_t state = arp_table[i].state;
-    if (state != ETHARP_STATE_EMPTY
-#if ETHARP_SUPPORT_STATIC_ENTRIES
-      && (arp_table[i].static_entry == 0)
-#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
-      ) {
-      arp_table[i].ctime++;
-      if ((arp_table[i].ctime >= ARP_MAXAGE) ||
-          ((arp_table[i].state == ETHARP_STATE_PENDING)  &&
-           (arp_table[i].ctime >= ARP_MAXPENDING))) {
-        /* pending or stable entry has become old! */
-        LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer: expired %s entry %"U16_F".\n",
-             arp_table[i].state == ETHARP_STATE_STABLE ? "stable" : "pending", (u16_t)i));
-        /* clean up entries that have just been expired */
-        free_entry(i);
-      }
-#if ARP_QUEUEING
-      /* still pending entry? (not expired) */
-      if (arp_table[i].state == ETHARP_STATE_PENDING) {
-        /* resend an ARP query here? */
-      }
-#endif /* ARP_QUEUEING */
-    }
-  }
-}
-
-/**
- * Search the ARP table for a matching or new entry.
- * 
- * If an IP address is given, return a pending or stable ARP entry that matches
- * the address. If no match is found, create a new entry with this address set,
- * but in state ETHARP_EMPTY. The caller must check and possibly change the
- * state of the returned entry.
- * 
- * If ipaddr is NULL, return a initialized new entry in state ETHARP_EMPTY.
- * 
- * In all cases, attempt to create new entries from an empty entry. If no
- * empty entries are available and ETHARP_FLAG_TRY_HARD flag is set, recycle
- * old entries. Heuristic choose the least important entry for recycling.
- *
- * @param ipaddr IP address to find in ARP cache, or to add if not found.
- * @param flags @see definition of ETHARP_FLAG_*
- * @param netif netif related to this address (used for NETIF_HWADDRHINT)
- *  
- * @return The ARP entry index that matched or is created, ERR_MEM if no
- * entry is found or could be recycled.
- */
-static s8_t
-find_entry(ip_addr_t *ipaddr, u8_t flags)
-{
-  s8_t old_pending = ARP_TABLE_SIZE, old_stable = ARP_TABLE_SIZE;
-  s8_t empty = ARP_TABLE_SIZE;
-  u8_t i = 0, age_pending = 0, age_stable = 0;
-#if ARP_QUEUEING
-  /* oldest entry with packets on queue */
-  s8_t old_queue = ARP_TABLE_SIZE;
-  /* its age */
-  u8_t age_queue = 0;
-#endif /* ARP_QUEUEING */
-
-  /**
-   * a) do a search through the cache, remember candidates
-   * b) select candidate entry
-   * c) create new entry
-   */
-
-  /* a) in a single search sweep, do all of this
-   * 1) remember the first empty entry (if any)
-   * 2) remember the oldest stable entry (if any)
-   * 3) remember the oldest pending entry without queued packets (if any)
-   * 4) remember the oldest pending entry with queued packets (if any)
-   * 5) search for a matching IP entry, either pending or stable
-   *    until 5 matches, or all entries are searched for.
-   */
-
-  for (i = 0; i < ARP_TABLE_SIZE; ++i) {
-    u8_t state = arp_table[i].state;
-    /* no empty entry found yet and now we do find one? */
-    if ((empty == ARP_TABLE_SIZE) && (state == ETHARP_STATE_EMPTY)) {
-      LWIP_DEBUGF(ETHARP_DEBUG, ("find_entry: found empty entry %"U16_F"\n", (u16_t)i));
-      /* remember first empty entry */
-      empty = i;
-    } else if (state != ETHARP_STATE_EMPTY) {
-      LWIP_ASSERT("state == ETHARP_STATE_PENDING || state == ETHARP_STATE_STABLE",
-        state == ETHARP_STATE_PENDING || state == ETHARP_STATE_STABLE);
-      /* if given, does IP address match IP address in ARP entry? */
-      if (ipaddr && ip_addr_cmp(ipaddr, &arp_table[i].ipaddr)) {
-        LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: found matching entry %"U16_F"\n", (u16_t)i));
-        /* found exact IP address match, simply bail out */
-        return i;
-      }
-      /* pending entry? */
-      if (state == ETHARP_STATE_PENDING) {
-        /* pending with queued packets? */
-#if ARP_QUEUEING
-        if (arp_table[i].q != NULL) {
-          if (arp_table[i].ctime >= age_queue) {
-            old_queue = i;
-            age_queue = arp_table[i].ctime;
-          }
-        } else
-#endif /* ARP_QUEUEING */
-        /* pending without queued packets? */
-        {
-          if (arp_table[i].ctime >= age_pending) {
-            old_pending = i;
-            age_pending = arp_table[i].ctime;
-          }
-        }
-      /* stable entry? */
-      } else if (state == ETHARP_STATE_STABLE) {
-#if ETHARP_SUPPORT_STATIC_ENTRIES
-        /* don't record old_stable for static entries since they never expire */
-        if (arp_table[i].static_entry == 0)
-#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
-        {
-          /* remember entry with oldest stable entry in oldest, its age in maxtime */
-          if (arp_table[i].ctime >= age_stable) {
-            old_stable = i;
-            age_stable = arp_table[i].ctime;
-          }
-        }
-      }
-    }
-  }
-  /* { we have no match } => try to create a new entry */
-   
-  /* don't create new entry, only search? */
-  if (((flags & ETHARP_FLAG_FIND_ONLY) != 0) ||
-      /* or no empty entry found and not allowed to recycle? */
-      ((empty == ARP_TABLE_SIZE) && ((flags & ETHARP_FLAG_TRY_HARD) == 0))) {
-    LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: no empty entry found and not allowed to recycle\n"));
-    return (s8_t)ERR_MEM;
-  }
-  
-  /* b) choose the least destructive entry to recycle:
-   * 1) empty entry
-   * 2) oldest stable entry
-   * 3) oldest pending entry without queued packets
-   * 4) oldest pending entry with queued packets
-   * 
-   * { ETHARP_FLAG_TRY_HARD is set at this point }
-   */ 
-
-  /* 1) empty entry available? */
-  if (empty < ARP_TABLE_SIZE) {
-    i = empty;
-    LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting empty entry %"U16_F"\n", (u16_t)i));
-  } else {
-    /* 2) found recyclable stable entry? */
-    if (old_stable < ARP_TABLE_SIZE) {
-      /* recycle oldest stable*/
-      i = old_stable;
-      LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting oldest stable entry %"U16_F"\n", (u16_t)i));
-#if ARP_QUEUEING
-      /* no queued packets should exist on stable entries */
-      LWIP_ASSERT("arp_table[i].q == NULL", arp_table[i].q == NULL);
-#endif /* ARP_QUEUEING */
-    /* 3) found recyclable pending entry without queued packets? */
-    } else if (old_pending < ARP_TABLE_SIZE) {
-      /* recycle oldest pending */
-      i = old_pending;
-      LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting oldest pending entry %"U16_F" (without queue)\n", (u16_t)i));
-#if ARP_QUEUEING
-    /* 4) found recyclable pending entry with queued packets? */
-    } else if (old_queue < ARP_TABLE_SIZE) {
-      /* recycle oldest pending (queued packets are free in free_entry) */
-      i = old_queue;
-      LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting oldest pending entry %"U16_F", freeing packet queue %p\n", (u16_t)i, (void *)(arp_table[i].q)));
-#endif /* ARP_QUEUEING */
-      /* no empty or recyclable entries found */
-    } else {
-      LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: no empty or recyclable entries found\n"));
-      return (s8_t)ERR_MEM;
-    }
-
-    /* { empty or recyclable entry found } */
-    LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE);
-    free_entry(i);
-  }
-
-  LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE);
-  LWIP_ASSERT("arp_table[i].state == ETHARP_STATE_EMPTY",
-    arp_table[i].state == ETHARP_STATE_EMPTY);
-
-  /* IP address given? */
-  if (ipaddr != NULL) {
-    /* set IP address */
-    ip_addr_copy(arp_table[i].ipaddr, *ipaddr);
-  }
-  arp_table[i].ctime = 0;
-#if ETHARP_SUPPORT_STATIC_ENTRIES
-  arp_table[i].static_entry = 0;
-#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
-  return (err_t)i;
-}
-
-/**
- * Send an IP packet on the network using netif->linkoutput
- * The ethernet header is filled in before sending.
- *
- * @params netif the lwIP network interface on which to send the packet
- * @params p the packet to send, p->payload pointing to the (uninitialized) ethernet header
- * @params src the source MAC address to be copied into the ethernet header
- * @params dst the destination MAC address to be copied into the ethernet header
- * @return ERR_OK if the packet was sent, any other err_t on failure
- */
-static err_t
-etharp_send_ip(struct netif *netif, struct pbuf *p, struct eth_addr *src, struct eth_addr *dst)
-{
-  struct eth_hdr *ethhdr = (struct eth_hdr *)p->payload;
-
-  LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!",
-              (netif->hwaddr_len == ETHARP_HWADDR_LEN));
-  ETHADDR32_COPY(&ethhdr->dest, dst);
-  ETHADDR16_COPY(&ethhdr->src, src);
-  ethhdr->type = PP_HTONS(ETHTYPE_IP);
-  LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_send_ip: sending packet %p\n", (void *)p));
-  /* send the packet */
-  return netif->linkoutput(netif, p);
-}
-
-/**
- * Update (or insert) a IP/MAC address pair in the ARP cache.
- *
- * If a pending entry is resolved, any queued packets will be sent
- * at this point.
- * 
- * @param netif netif related to this entry (used for NETIF_ADDRHINT)
- * @param ipaddr IP address of the inserted ARP entry.
- * @param ethaddr Ethernet address of the inserted ARP entry.
- * @param flags @see definition of ETHARP_FLAG_*
- *
- * @return
- * - ERR_OK Succesfully updated ARP cache.
- * - ERR_MEM If we could not add a new ARP entry when ETHARP_FLAG_TRY_HARD was set.
- * - ERR_ARG Non-unicast address given, those will not appear in ARP cache.
- *
- * @see pbuf_free()
- */
-static err_t
-update_arp_entry(struct netif *netif, ip_addr_t *ipaddr, struct eth_addr *ethaddr, u8_t flags)
-{
-  s8_t i;
-  LWIP_ASSERT("netif->hwaddr_len == ETHARP_HWADDR_LEN", netif->hwaddr_len == ETHARP_HWADDR_LEN);
-  LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("update_arp_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F" - %02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F"\n",
-    ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr),
-    ethaddr->addr[0], ethaddr->addr[1], ethaddr->addr[2],
-    ethaddr->addr[3], ethaddr->addr[4], ethaddr->addr[5]));
-  /* non-unicast address? */
-  if (ip_addr_isany(ipaddr) ||
-      ip_addr_isbroadcast(ipaddr, netif) ||
-      ip_addr_ismulticast(ipaddr)) {
-    LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("update_arp_entry: will not add non-unicast IP address to ARP cache\n"));
-    return ERR_ARG;
-  }
-  /* find or create ARP entry */
-  i = find_entry(ipaddr, flags);
-  /* bail out if no entry could be found */
-  if (i < 0) {
-    return (err_t)i;
-  }
-
-#if ETHARP_SUPPORT_STATIC_ENTRIES
-  if (flags & ETHARP_FLAG_STATIC_ENTRY) {
-    /* record static type */
-    arp_table[i].static_entry = 1;
-  }
-#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
-
-  /* mark it stable */
-  arp_table[i].state = ETHARP_STATE_STABLE;
-
-#if LWIP_SNMP
-  /* record network interface */
-  arp_table[i].netif = netif;
-#endif /* LWIP_SNMP */
-  /* insert in SNMP ARP index tree */
-  snmp_insert_arpidx_tree(netif, &arp_table[i].ipaddr);
-
-  LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("update_arp_entry: updating stable entry %"S16_F"\n", (s16_t)i));
-  /* update address */
-  ETHADDR32_COPY(&arp_table[i].ethaddr, ethaddr);
-  /* reset time stamp */
-  arp_table[i].ctime = 0;
-#if ARP_QUEUEING
-  /* this is where we will send out queued packets! */
-  while (arp_table[i].q != NULL) {
-    struct pbuf *p;
-    /* remember remainder of queue */
-    struct etharp_q_entry *q = arp_table[i].q;
-    /* pop first item off the queue */
-    arp_table[i].q = q->next;
-    /* get the packet pointer */
-    p = q->p;
-    /* now queue entry can be freed */
-    memp_free(MEMP_ARP_QUEUE, q);
-    /* send the queued IP packet */
-    etharp_send_ip(netif, p, (struct eth_addr*)(netif->hwaddr), ethaddr);
-    /* free the queued IP packet */
-    pbuf_free(p);
-  }
-#endif /* ARP_QUEUEING */
-  return ERR_OK;
-}
-
-#if ETHARP_SUPPORT_STATIC_ENTRIES
-/** Add a new static entry to the ARP table. If an entry exists for the
- * specified IP address, this entry is overwritten.
- * If packets are queued for the specified IP address, they are sent out.
- *
- * @param ipaddr IP address for the new static entry
- * @param ethaddr ethernet address for the new static entry
- * @return @see return values of etharp_add_static_entry
- */
-err_t
-etharp_add_static_entry(ip_addr_t *ipaddr, struct eth_addr *ethaddr)
-{
-  struct netif *netif;
-  LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_add_static_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F" - %02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F"\n",
-    ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr),
-    ethaddr->addr[0], ethaddr->addr[1], ethaddr->addr[2],
-    ethaddr->addr[3], ethaddr->addr[4], ethaddr->addr[5]));
-
-  netif = ip_route(ipaddr);
-  if (netif == NULL) {
-    return ERR_RTE;
-  }
-
-  return update_arp_entry(netif, ipaddr, ethaddr, ETHARP_FLAG_TRY_HARD | ETHARP_FLAG_STATIC_ENTRY);
-}
-
-/** Remove a static entry from the ARP table previously added with a call to
- * etharp_add_static_entry.
- *
- * @param ipaddr IP address of the static entry to remove
- * @return ERR_OK: entry removed
- *         ERR_MEM: entry wasn't found
- *         ERR_ARG: entry wasn't a static entry but a dynamic one
- */
-err_t
-etharp_remove_static_entry(ip_addr_t *ipaddr)
-{
-  s8_t i;
-  LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_remove_static_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
-    ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr)));
-
-  /* find or create ARP entry */
-  i = find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY);
-  /* bail out if no entry could be found */
-  if (i < 0) {
-    return (err_t)i;
-  }
-
-  if ((arp_table[i].state != ETHARP_STATE_STABLE) ||
-    (arp_table[i].static_entry == 0)) {
-    /* entry wasn't a static entry, cannot remove it */
-    return ERR_ARG;
-  }
-  /* entry found, free it */
-  free_entry(i);
-  return ERR_OK;
-}
-#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
-
-/**
- * Finds (stable) ethernet/IP address pair from ARP table
- * using interface and IP address index.
- * @note the addresses in the ARP table are in network order!
- *
- * @param netif points to interface index
- * @param ipaddr points to the (network order) IP address index
- * @param eth_ret points to return pointer
- * @param ip_ret points to return pointer
- * @return table index if found, -1 otherwise
- */
-s8_t
-etharp_find_addr(struct netif *netif, ip_addr_t *ipaddr,
-         struct eth_addr **eth_ret, ip_addr_t **ip_ret)
-{
-  s8_t i;
-
-  LWIP_ASSERT("eth_ret != NULL && ip_ret != NULL",
-    eth_ret != NULL && ip_ret != NULL);
-
-  LWIP_UNUSED_ARG(netif);
-
-  i = find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY);
-  if((i >= 0) && arp_table[i].state == ETHARP_STATE_STABLE) {
-      *eth_ret = &arp_table[i].ethaddr;
-      *ip_ret = &arp_table[i].ipaddr;
-      return i;
-  }
-  return -1;
-}
-
-#if ETHARP_TRUST_IP_MAC
-/**
- * Updates the ARP table using the given IP packet.
- *
- * Uses the incoming IP packet's source address to update the
- * ARP cache for the local network. The function does not alter
- * or free the packet. This function must be called before the
- * packet p is passed to the IP layer.
- *
- * @param netif The lwIP network interface on which the IP packet pbuf arrived.
- * @param p The IP packet that arrived on netif.
- *
- * @return NULL
- *
- * @see pbuf_free()
- */
-static void
-etharp_ip_input(struct netif *netif, struct pbuf *p)
-{
-  struct eth_hdr *ethhdr;
-  struct ip_hdr *iphdr;
-  ip_addr_t iphdr_src;
-  LWIP_ERROR("netif != NULL", (netif != NULL), return;);
-
-  /* Only insert an entry if the source IP address of the
-     incoming IP packet comes from a host on the local network. */
-  ethhdr = (struct eth_hdr *)p->payload;
-  iphdr = (struct ip_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR);
-#if ETHARP_SUPPORT_VLAN
-  if (ethhdr->type == ETHTYPE_VLAN) {
-    iphdr = (struct ip_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR);
-  }
-#endif /* ETHARP_SUPPORT_VLAN */
-
-  ip_addr_copy(iphdr_src, iphdr->src);
-
-  /* source is not on the local network? */
-  if (!ip_addr_netcmp(&iphdr_src, &(netif->ip_addr), &(netif->netmask))) {
-    /* do nothing */
-    return;
-  }
-
-  LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_ip_input: updating ETHARP table.\n"));
-  /* update the source IP address in the cache, if present */
-  /* @todo We could use ETHARP_FLAG_TRY_HARD if we think we are going to talk
-   * back soon (for example, if the destination IP address is ours. */
-  update_arp_entry(netif, &iphdr_src, &(ethhdr->src), ETHARP_FLAG_FIND_ONLY);
-}
-#endif /* ETHARP_TRUST_IP_MAC */
-
-/**
- * Responds to ARP requests to us. Upon ARP replies to us, add entry to cache  
- * send out queued IP packets. Updates cache with snooped address pairs.
- *
- * Should be called for incoming ARP packets. The pbuf in the argument
- * is freed by this function.
- *
- * @param netif The lwIP network interface on which the ARP packet pbuf arrived.
- * @param ethaddr Ethernet address of netif.
- * @param p The ARP packet that arrived on netif. Is freed by this function.
- *
- * @return NULL
- *
- * @see pbuf_free()
- */
-static void
-etharp_arp_input(struct netif *netif, struct eth_addr *ethaddr, struct pbuf *p)
-{
-  struct etharp_hdr *hdr;
-  struct eth_hdr *ethhdr;
-  /* these are aligned properly, whereas the ARP header fields might not be */
-  ip_addr_t sipaddr, dipaddr;
-  u8_t for_us;
-#if LWIP_AUTOIP
-  const u8_t * ethdst_hwaddr;
-#endif /* LWIP_AUTOIP */
-
-  LWIP_ERROR("netif != NULL", (netif != NULL), return;);
-
-  /* drop short ARP packets: we have to check for p->len instead of p->tot_len here
-     since a struct etharp_hdr is pointed to p->payload, so it musn't be chained! */
-  if (p->len < SIZEOF_ETHARP_PACKET) {
-    LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
-      ("etharp_arp_input: packet dropped, too short (%"S16_F"/%"S16_F")\n", p->tot_len,
-      (s16_t)SIZEOF_ETHARP_PACKET));
-    ETHARP_STATS_INC(etharp.lenerr);
-    ETHARP_STATS_INC(etharp.drop);
-    pbuf_free(p);
-    return;
-  }
-
-  ethhdr = (struct eth_hdr *)p->payload;
-  hdr = (struct etharp_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR);
-#if ETHARP_SUPPORT_VLAN
-  if (ethhdr->type == ETHTYPE_VLAN) {
-    hdr = (struct etharp_hdr *)(((u8_t*)ethhdr) + SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR);
-  }
-#endif /* ETHARP_SUPPORT_VLAN */
-
-  /* RFC 826 "Packet Reception": */
-  if ((hdr->hwtype != PP_HTONS(HWTYPE_ETHERNET)) ||
-      (hdr->hwlen != ETHARP_HWADDR_LEN) ||
-      (hdr->protolen != sizeof(ip_addr_t)) ||
-      (hdr->proto != PP_HTONS(ETHTYPE_IP)) ||
-      (ethhdr->type != PP_HTONS(ETHTYPE_ARP)))  {
-    LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
-      ("etharp_arp_input: packet dropped, wrong hw type, hwlen, proto, protolen or ethernet type (%"U16_F"/%"U16_F"/%"U16_F"/%"U16_F"/%"U16_F")\n",
-      hdr->hwtype, hdr->hwlen, hdr->proto, hdr->protolen, ethhdr->type));
-    ETHARP_STATS_INC(etharp.proterr);
-    ETHARP_STATS_INC(etharp.drop);
-    pbuf_free(p);
-    return;
-  }
-  ETHARP_STATS_INC(etharp.recv);
-
-#if LWIP_AUTOIP
-  /* We have to check if a host already has configured our random
-   * created link local address and continously check if there is
-   * a host with this IP-address so we can detect collisions */
-  autoip_arp_reply(netif, hdr);
-#endif /* LWIP_AUTOIP */
-
-  /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without
-   * structure packing (not using structure copy which breaks strict-aliasing rules). */
-  IPADDR2_COPY(&sipaddr, &hdr->sipaddr);
-  IPADDR2_COPY(&dipaddr, &hdr->dipaddr);
-
-  /* this interface is not configured? */
-  if (ip_addr_isany(&netif->ip_addr)) {
-    for_us = 0;
-  } else {
-    /* ARP packet directed to us? */
-    for_us = (u8_t)ip_addr_cmp(&dipaddr, &(netif->ip_addr));
-  }
-
-  /* ARP message directed to us?
-      -> add IP address in ARP cache; assume requester wants to talk to us,
-         can result in directly sending the queued packets for this host.
-     ARP message not directed to us?
-      ->  update the source IP address in the cache, if present */
-  update_arp_entry(netif, &sipaddr, &(hdr->shwaddr),
-                   for_us ? ETHARP_FLAG_TRY_HARD : ETHARP_FLAG_FIND_ONLY);
-
-  /* now act on the message itself */
-  switch (hdr->opcode) {
-  /* ARP request? */
-  case PP_HTONS(ARP_REQUEST):
-    /* ARP request. If it asked for our address, we send out a
-     * reply. In any case, we time-stamp any existing ARP entry,
-     * and possiby send out an IP packet that was queued on it. */
-
-    LWIP_DEBUGF (ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: incoming ARP request\n"));
-    /* ARP request for our address? */
-    if (for_us) {
-
-      LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: replying to ARP request for our IP address\n"));
-      /* Re-use pbuf to send ARP reply.
-         Since we are re-using an existing pbuf, we can't call etharp_raw since
-         that would allocate a new pbuf. */
-      hdr->opcode = htons(ARP_REPLY);
-
-      IPADDR2_COPY(&hdr->dipaddr, &hdr->sipaddr);
-      IPADDR2_COPY(&hdr->sipaddr, &netif->ip_addr);
-
-      LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!",
-                  (netif->hwaddr_len == ETHARP_HWADDR_LEN));
-#if LWIP_AUTOIP
-      /* If we are using Link-Local, all ARP packets that contain a Link-Local
-       * 'sender IP address' MUST be sent using link-layer broadcast instead of
-       * link-layer unicast. (See RFC3927 Section 2.5, last paragraph) */
-      ethdst_hwaddr = ip_addr_islinklocal(&netif->ip_addr) ? (u8_t*)(ethbroadcast.addr) : hdr->shwaddr.addr;
-#endif /* LWIP_AUTOIP */
-
-      ETHADDR16_COPY(&hdr->dhwaddr, &hdr->shwaddr);
-#if LWIP_AUTOIP
-      ETHADDR16_COPY(&ethhdr->dest, ethdst_hwaddr);
-#else  /* LWIP_AUTOIP */
-      ETHADDR16_COPY(&ethhdr->dest, &hdr->shwaddr);
-#endif /* LWIP_AUTOIP */
-      ETHADDR16_COPY(&hdr->shwaddr, ethaddr);
-      ETHADDR16_COPY(&ethhdr->src, ethaddr);
-
-      /* hwtype, hwaddr_len, proto, protolen and the type in the ethernet header
-         are already correct, we tested that before */
-
-      /* return ARP reply */
-      netif->linkoutput(netif, p);
-    /* we are not configured? */
-    } else if (ip_addr_isany(&netif->ip_addr)) {
-      /* { for_us == 0 and netif->ip_addr.addr == 0 } */
-      LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: we are unconfigured, ARP request ignored.\n"));
-    /* request was not directed to us */
-    } else {
-      /* { for_us == 0 and netif->ip_addr.addr != 0 } */
-      LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: ARP request was not for us.\n"));
-    }
-    break;
-  case PP_HTONS(ARP_REPLY):
-    /* ARP reply. We already updated the ARP cache earlier. */
-    LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: incoming ARP reply\n"));
-#if (LWIP_DHCP && DHCP_DOES_ARP_CHECK)
-    /* DHCP wants to know about ARP replies from any host with an
-     * IP address also offered to us by the DHCP server. We do not
-     * want to take a duplicate IP address on a single network.
-     * @todo How should we handle redundant (fail-over) interfaces? */
-    dhcp_arp_reply(netif, &sipaddr);
-#endif /* (LWIP_DHCP && DHCP_DOES_ARP_CHECK) */
-    break;
-  default:
-    LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: ARP unknown opcode type %"S16_F"\n", htons(hdr->opcode)));
-    ETHARP_STATS_INC(etharp.err);
-    break;
-  }
-  /* free ARP packet */
-  pbuf_free(p);
-}
-
-/**
- * Resolve and fill-in Ethernet address header for outgoing IP packet.
- *
- * For IP multicast and broadcast, corresponding Ethernet addresses
- * are selected and the packet is transmitted on the link.
- *
- * For unicast addresses, the packet is submitted to etharp_query(). In
- * case the IP address is outside the local network, the IP address of
- * the gateway is used.
- *
- * @param netif The lwIP network interface which the IP packet will be sent on.
- * @param q The pbuf(s) containing the IP packet to be sent.
- * @param ipaddr The IP address of the packet destination.
- *
- * @return
- * - ERR_RTE No route to destination (no gateway to external networks),
- * or the return type of either etharp_query() or etharp_send_ip().
- */
-err_t
-etharp_output(struct netif *netif, struct pbuf *q, ip_addr_t *ipaddr)
-{
-  struct eth_addr *dest, mcastaddr;
-
-  /* make room for Ethernet header - should not fail */
-  if (pbuf_header(q, sizeof(struct eth_hdr)) != 0) {
-    /* bail out */
-    LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
-      ("etharp_output: could not allocate room for header.\n"));
-    LINK_STATS_INC(link.lenerr);
-    return ERR_BUF;
-  }
-
-  /* assume unresolved Ethernet address */
-  dest = NULL;
-  /* Determine on destination hardware address. Broadcasts and multicasts
-   * are special, other IP addresses are looked up in the ARP table. */
-
-  /* broadcast destination IP address? */
-  if (ip_addr_isbroadcast(ipaddr, netif)) {
-    /* broadcast on Ethernet also */
-    dest = (struct eth_addr *)&ethbroadcast;
-  /* multicast destination IP address? */
-  } else if (ip_addr_ismulticast(ipaddr)) {
-    /* Hash IP multicast address to MAC address.*/
-    mcastaddr.addr[0] = 0x01;
-    mcastaddr.addr[1] = 0x00;
-    mcastaddr.addr[2] = 0x5e;
-    mcastaddr.addr[3] = ip4_addr2(ipaddr) & 0x7f;
-    mcastaddr.addr[4] = ip4_addr3(ipaddr);
-    mcastaddr.addr[5] = ip4_addr4(ipaddr);
-    /* destination Ethernet address is multicast */
-    dest = &mcastaddr;
-  /* unicast destination IP address? */
-  } else {
-    /* outside local network? */
-    if (!ip_addr_netcmp(ipaddr, &(netif->ip_addr), &(netif->netmask)) &&
-        !ip_addr_islinklocal(ipaddr)) {
-      /* interface has default gateway? */
-      if (!ip_addr_isany(&netif->gw)) {
-        /* send to hardware address of default gateway IP address */
-        ipaddr = &(netif->gw);
-      /* no default gateway available */
-      } else {
-        /* no route to destination error (default gateway missing) */
-        return ERR_RTE;
-      }
-    }
-#if LWIP_NETIF_HWADDRHINT
-    if (netif->addr_hint != NULL) {
-      /* per-pcb cached entry was given */
-      u8_t etharp_cached_entry = *(netif->addr_hint);
-      if (etharp_cached_entry < ARP_TABLE_SIZE) {
-#endif /* LWIP_NETIF_HWADDRHINT */
-        if ((arp_table[etharp_cached_entry].state == ETHARP_STATE_STABLE) &&
-            (ip_addr_cmp(ipaddr, &arp_table[etharp_cached_entry].ipaddr))) {
-          /* the per-pcb-cached entry is stable and the right one! */
-          ETHARP_STATS_INC(etharp.cachehit);
-          return etharp_send_ip(netif, q, (struct eth_addr*)(netif->hwaddr),
-            &arp_table[etharp_cached_entry].ethaddr);
-        }
-#if LWIP_NETIF_HWADDRHINT
-      }
-    }
-#endif /* LWIP_NETIF_HWADDRHINT */
-    /* queue on destination Ethernet address belonging to ipaddr */
-    return etharp_query(netif, ipaddr, q);
-  }
-
-  /* continuation for multicast/broadcast destinations */
-  /* obtain source Ethernet address of the given interface */
-  /* send packet directly on the link */
-  return etharp_send_ip(netif, q, (struct eth_addr*)(netif->hwaddr), dest);
-}
-
-/**
- * Send an ARP request for the given IP address and/or queue a packet.
- *
- * If the IP address was not yet in the cache, a pending ARP cache entry
- * is added and an ARP request is sent for the given address. The packet
- * is queued on this entry.
- *
- * If the IP address was already pending in the cache, a new ARP request
- * is sent for the given address. The packet is queued on this entry.
- *
- * If the IP address was already stable in the cache, and a packet is
- * given, it is directly sent and no ARP request is sent out. 
- * 
- * If the IP address was already stable in the cache, and no packet is
- * given, an ARP request is sent out.
- * 
- * @param netif The lwIP network interface on which ipaddr
- * must be queried for.
- * @param ipaddr The IP address to be resolved.
- * @param q If non-NULL, a pbuf that must be delivered to the IP address.
- * q is not freed by this function.
- *
- * @note q must only be ONE packet, not a packet queue!
- *
- * @return
- * - ERR_BUF Could not make room for Ethernet header.
- * - ERR_MEM Hardware address unknown, and no more ARP entries available
- *   to query for address or queue the packet.
- * - ERR_MEM Could not queue packet due to memory shortage.
- * - ERR_RTE No route to destination (no gateway to external networks).
- * - ERR_ARG Non-unicast address given, those will not appear in ARP cache.
- *
- */
-err_t
-etharp_query(struct netif *netif, ip_addr_t *ipaddr, struct pbuf *q)
-{
-  struct eth_addr * srcaddr = (struct eth_addr *)netif->hwaddr;
-  err_t result = ERR_MEM;
-  s8_t i; /* ARP entry index */
-
-  /* non-unicast address? */
-  if (ip_addr_isbroadcast(ipaddr, netif) ||
-      ip_addr_ismulticast(ipaddr) ||
-      ip_addr_isany(ipaddr)) {
-    LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: will not add non-unicast IP address to ARP cache\n"));
-    return ERR_ARG;
-  }
-
-  /* find entry in ARP cache, ask to create entry if queueing packet */
-  i = find_entry(ipaddr, ETHARP_FLAG_TRY_HARD);
-
-  /* could not find or create entry? */
-  if (i < 0) {
-    LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: could not create ARP entry\n"));
-    if (q) {
-      LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: packet dropped\n"));
-      ETHARP_STATS_INC(etharp.memerr);
-    }
-    return (err_t)i;
-  }
-
-  /* mark a fresh entry as pending (we just sent a request) */
-  if (arp_table[i].state == ETHARP_STATE_EMPTY) {
-    arp_table[i].state = ETHARP_STATE_PENDING;
-  }
-
-  /* { i is either a STABLE or (new or existing) PENDING entry } */
-  LWIP_ASSERT("arp_table[i].state == PENDING or STABLE",
-  ((arp_table[i].state == ETHARP_STATE_PENDING) ||
-   (arp_table[i].state == ETHARP_STATE_STABLE)));
-
-  /* do we have a pending entry? or an implicit query request? */
-  if ((arp_table[i].state == ETHARP_STATE_PENDING) || (q == NULL)) {
-    /* try to resolve it; send out ARP request */
-    result = etharp_request(netif, ipaddr);
-    if (result != ERR_OK) {
-      /* ARP request couldn't be sent */
-      /* We don't re-send arp request in etharp_tmr, but we still queue packets,
-         since this failure could be temporary, and the next packet calling
-         etharp_query again could lead to sending the queued packets. */
-    }
-    if (q == NULL) {
-      return result;
-    }
-  }
-
-  /* packet given? */
-  LWIP_ASSERT("q != NULL", q != NULL);
-  /* stable entry? */
-  if (arp_table[i].state == ETHARP_STATE_STABLE) {
-    /* we have a valid IP->Ethernet address mapping */
-    ETHARP_SET_HINT(netif, i);
-    /* send the packet */
-    result = etharp_send_ip(netif, q, srcaddr, &(arp_table[i].ethaddr));
-  /* pending entry? (either just created or already pending */
-  } else if (arp_table[i].state == ETHARP_STATE_PENDING) {
-#if ARP_QUEUEING /* queue the given q packet */
-    struct pbuf *p;
-    int copy_needed = 0;
-    /* IF q includes a PBUF_REF, PBUF_POOL or PBUF_RAM, we have no choice but
-     * to copy the whole queue into a new PBUF_RAM (see bug #11400) 
-     * PBUF_ROMs can be left as they are, since ROM must not get changed. */
-    p = q;
-    while (p) {
-      LWIP_ASSERT("no packet queues allowed!", (p->len != p->tot_len) || (p->next == 0));
-      if(p->type != PBUF_ROM) {
-        copy_needed = 1;
-        break;
-      }
-      p = p->next;
-    }
-    if(copy_needed) {
-      /* copy the whole packet into new pbufs */
-      p = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
-      if(p != NULL) {
-        if (pbuf_copy(p, q) != ERR_OK) {
-          pbuf_free(p);
-          p = NULL;
-        }
-      }
-    } else {
-      /* referencing the old pbuf is enough */
-      p = q;
-      pbuf_ref(p);
-    }
-    /* packet could be taken over? */
-    if (p != NULL) {
-      /* queue packet ... */
-      struct etharp_q_entry *new_entry;
-      /* allocate a new arp queue entry */
-      new_entry = (struct etharp_q_entry *)memp_malloc(MEMP_ARP_QUEUE);
-      if (new_entry != NULL) {
-        new_entry->next = 0;
-        new_entry->p = p;
-        if(arp_table[i].q != NULL) {
-          /* queue was already existent, append the new entry to the end */
-          struct etharp_q_entry *r;
-          r = arp_table[i].q;
-          while (r->next != NULL) {
-            r = r->next;
-          }
-          r->next = new_entry;
-        } else {
-          /* queue did not exist, first item in queue */
-          arp_table[i].q = new_entry;
-        }
-        LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: queued packet %p on ARP entry %"S16_F"\n", (void *)q, (s16_t)i));
-        result = ERR_OK;
-      } else {
-        /* the pool MEMP_ARP_QUEUE is empty */
-        pbuf_free(p);
-        LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: could not queue a copy of PBUF_REF packet %p (out of memory)\n", (void *)q));
-        /* { result == ERR_MEM } through initialization */
-      }
-    } else {
-      ETHARP_STATS_INC(etharp.memerr);
-      LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: could not queue a copy of PBUF_REF packet %p (out of memory)\n", (void *)q));
-      /* { result == ERR_MEM } through initialization */
-    }
-#else /* ARP_QUEUEING */
-    /* q && state == PENDING && ARP_QUEUEING == 0 => result = ERR_MEM */
-    /* { result == ERR_MEM } through initialization */
-    LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: Ethernet destination address unknown, queueing disabled, packet %p dropped\n", (void *)q));
-#endif /* ARP_QUEUEING */
-  }
-  return result;
-}
-
-/**
- * Send a raw ARP packet (opcode and all addresses can be modified)
- *
- * @param netif the lwip network interface on which to send the ARP packet
- * @param ethsrc_addr the source MAC address for the ethernet header
- * @param ethdst_addr the destination MAC address for the ethernet header
- * @param hwsrc_addr the source MAC address for the ARP protocol header
- * @param ipsrc_addr the source IP address for the ARP protocol header
- * @param hwdst_addr the destination MAC address for the ARP protocol header
- * @param ipdst_addr the destination IP address for the ARP protocol header
- * @param opcode the type of the ARP packet
- * @return ERR_OK if the ARP packet has been sent
- *         ERR_MEM if the ARP packet couldn't be allocated
- *         any other err_t on failure
- */
-#if !LWIP_AUTOIP
-static
-#endif /* LWIP_AUTOIP */
-err_t
-etharp_raw(struct netif *netif, const struct eth_addr *ethsrc_addr,
-           const struct eth_addr *ethdst_addr,
-           const struct eth_addr *hwsrc_addr, const ip_addr_t *ipsrc_addr,
-           const struct eth_addr *hwdst_addr, const ip_addr_t *ipdst_addr,
-           const u16_t opcode)
-{
-  struct pbuf *p;
-  err_t result = ERR_OK;
-  struct eth_hdr *ethhdr;
-  struct etharp_hdr *hdr;
-#if LWIP_AUTOIP
-  const u8_t * ethdst_hwaddr;
-#endif /* LWIP_AUTOIP */
-
-  /* allocate a pbuf for the outgoing ARP request packet */
-  p = pbuf_alloc(PBUF_RAW, SIZEOF_ETHARP_PACKET, PBUF_RAM);
-  /* could allocate a pbuf for an ARP request? */
-  if (p == NULL) {
-    LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
-      ("etharp_raw: could not allocate pbuf for ARP request.\n"));
-    ETHARP_STATS_INC(etharp.memerr);
-    return ERR_MEM;
-  }
-  LWIP_ASSERT("check that first pbuf can hold struct etharp_hdr",
-              (p->len >= SIZEOF_ETHARP_PACKET));
-
-  ethhdr = (struct eth_hdr *)p->payload;
-  hdr = (struct etharp_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR);
-  LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_raw: sending raw ARP packet.\n"));
-  hdr->opcode = htons(opcode);
-
-  LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!",
-              (netif->hwaddr_len == ETHARP_HWADDR_LEN));
-#if LWIP_AUTOIP
-  /* If we are using Link-Local, all ARP packets that contain a Link-Local
-   * 'sender IP address' MUST be sent using link-layer broadcast instead of
-   * link-layer unicast. (See RFC3927 Section 2.5, last paragraph) */
-  ethdst_hwaddr = ip_addr_islinklocal(ipsrc_addr) ? (u8_t*)(ethbroadcast.addr) : ethdst_addr->addr;
-#endif /* LWIP_AUTOIP */
-  /* Write the ARP MAC-Addresses */
-  ETHADDR16_COPY(&hdr->shwaddr, hwsrc_addr);
-  ETHADDR16_COPY(&hdr->dhwaddr, hwdst_addr);
-  /* Write the Ethernet MAC-Addresses */
-#if LWIP_AUTOIP
-  ETHADDR16_COPY(&ethhdr->dest, ethdst_hwaddr);
-#else  /* LWIP_AUTOIP */
-  ETHADDR16_COPY(&ethhdr->dest, ethdst_addr);
-#endif /* LWIP_AUTOIP */
-  ETHADDR16_COPY(&ethhdr->src, ethsrc_addr);
-  /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without
-   * structure packing. */ 
-  IPADDR2_COPY(&hdr->sipaddr, ipsrc_addr);
-  IPADDR2_COPY(&hdr->dipaddr, ipdst_addr);
-
-  hdr->hwtype = PP_HTONS(HWTYPE_ETHERNET);
-  hdr->proto = PP_HTONS(ETHTYPE_IP);
-  /* set hwlen and protolen */
-  hdr->hwlen = ETHARP_HWADDR_LEN;
-  hdr->protolen = sizeof(ip_addr_t);
-
-  ethhdr->type = PP_HTONS(ETHTYPE_ARP);
-  /* send ARP query */
-  result = netif->linkoutput(netif, p);
-  ETHARP_STATS_INC(etharp.xmit);
-  /* free ARP query packet */
-  pbuf_free(p);
-  p = NULL;
-  /* could not allocate pbuf for ARP request */
-
-  return result;
-}
-
-/**
- * Send an ARP request packet asking for ipaddr.
- *
- * @param netif the lwip network interface on which to send the request
- * @param ipaddr the IP address for which to ask
- * @return ERR_OK if the request has been sent
- *         ERR_MEM if the ARP packet couldn't be allocated
- *         any other err_t on failure
- */
-err_t
-etharp_request(struct netif *netif, ip_addr_t *ipaddr)
-{
-  LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_request: sending ARP request.\n"));
-  return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, &ethbroadcast,
-                    (struct eth_addr *)netif->hwaddr, &netif->ip_addr, &ethzero,
-                    ipaddr, ARP_REQUEST);
-}
-#endif /* LWIP_ARP */
-
-/**
- * Process received ethernet frames. Using this function instead of directly
- * calling ip_input and passing ARP frames through etharp in ethernetif_input,
- * the ARP cache is protected from concurrent access.
- *
- * @param p the recevied packet, p->payload pointing to the ethernet header
- * @param netif the network interface on which the packet was received
- */
-err_t
-ethernet_input(struct pbuf *p, struct netif *netif)
-{
-  struct eth_hdr* ethhdr;
-  u16_t type;
-
-  /* points to packet payload, which starts with an Ethernet header */
-  ethhdr = (struct eth_hdr *)p->payload;
-  LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE,
-    ("ethernet_input: dest:%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F", src:%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F", type:%"X16_F"\n",
-     (unsigned)ethhdr->dest.addr[0], (unsigned)ethhdr->dest.addr[1], (unsigned)ethhdr->dest.addr[2],
-     (unsigned)ethhdr->dest.addr[3], (unsigned)ethhdr->dest.addr[4], (unsigned)ethhdr->dest.addr[5],
-     (unsigned)ethhdr->src.addr[0], (unsigned)ethhdr->src.addr[1], (unsigned)ethhdr->src.addr[2],
-     (unsigned)ethhdr->src.addr[3], (unsigned)ethhdr->src.addr[4], (unsigned)ethhdr->src.addr[5],
-     (unsigned)htons(ethhdr->type)));
-
-  type = ethhdr->type;
-#if ETHARP_SUPPORT_VLAN
-  if (type == PP_HTONS(ETHTYPE_VLAN)) {
-    struct eth_vlan_hdr *vlan = (struct eth_vlan_hdr*)(((char*)ethhdr) + SIZEOF_ETH_HDR);
-#ifdef ETHARP_VLAN_CHECK /* if not, allow all VLANs */
-    if (VLAN_ID(vlan) != ETHARP_VLAN_CHECK) {
-      /* silently ignore this packet: not for our VLAN */
-      pbuf_free(p);
-      return ERR_OK;
-    }
-#endif /* ETHARP_VLAN_CHECK */
-    type = vlan->tpid;
-  }
-#endif /* ETHARP_SUPPORT_VLAN */
-
-#if LWIP_ARP_FILTER_NETIF
-  netif = LWIP_ARP_FILTER_NETIF_FN(p, netif, htons(type));
-#endif /* LWIP_ARP_FILTER_NETIF*/
-
-  switch (type) {
-#if LWIP_ARP
-    /* IP packet? */
-    case PP_HTONS(ETHTYPE_IP):
-      if (!(netif->flags & NETIF_FLAG_ETHARP)) {
-        goto free_and_return;
-      }
-#if ETHARP_TRUST_IP_MAC
-      /* update ARP table */
-      etharp_ip_input(netif, p);
-#endif /* ETHARP_TRUST_IP_MAC */
-      /* skip Ethernet header */
-      if(pbuf_header(p, -(s16_t)SIZEOF_ETH_HDR)) {
-        LWIP_ASSERT("Can't move over header in packet", 0);
-        goto free_and_return;
-      } else {
-        /* pass to IP layer */
-        ip_input(p, netif);
-      }
-      break;
-      
-    case PP_HTONS(ETHTYPE_ARP):
-      if (!(netif->flags & NETIF_FLAG_ETHARP)) {
-        goto free_and_return;
-      }
-      /* pass p to ARP module */
-      etharp_arp_input(netif, (struct eth_addr*)(netif->hwaddr), p);
-      break;
-#endif /* LWIP_ARP */
-#if PPPOE_SUPPORT
-    case PP_HTONS(ETHTYPE_PPPOEDISC): /* PPP Over Ethernet Discovery Stage */
-      pppoe_disc_input(netif, p);
-      break;
-
-    case PP_HTONS(ETHTYPE_PPPOE): /* PPP Over Ethernet Session Stage */
-      pppoe_data_input(netif, p);
-      break;
-#endif /* PPPOE_SUPPORT */
-
-    default:
-      ETHARP_STATS_INC(etharp.proterr);
-      ETHARP_STATS_INC(etharp.drop);
-      goto free_and_return;
-  }
-
-  /* This means the pbuf is freed or consumed,
-     so the caller doesn't have to free it again */
-  return ERR_OK;
-
-free_and_return:
-  pbuf_free(p);
-  return ERR_OK;
-}
-#endif /* LWIP_ARP || LWIP_ETHERNET */