1285 lines
46 KiB
C
1285 lines
46 KiB
C
/**
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* @file
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* Address Resolution Protocol module for IP over Ethernet
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*
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* Functionally, ARP is divided into two parts. The first maps an IP address
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* to a physical address when sending a packet, and the second part answers
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* requests from other machines for our physical address.
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*
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* This implementation complies with RFC 826 (Ethernet ARP). It supports
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* Gratuitious ARP from RFC3220 (IP Mobility Support for IPv4) section 4.6
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* if an interface calls etharp_gratuitous(our_netif) upon address change.
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*/
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/*
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* Copyright (c) 2001-2003 Swedish Institute of Computer Science.
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* Copyright (c) 2003-2004 Leon Woestenberg <leon.woestenberg@axon.tv>
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* Copyright (c) 2003-2004 Axon Digital Design B.V., The Netherlands.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without modification,
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* are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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* OF SUCH DAMAGE.
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*
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* This file is part of the lwIP TCP/IP stack.
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*
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*/
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#include "lwip/opt.h"
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#if LWIP_ARP || LWIP_ETHERNET
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#include "lwip/ip_addr.h"
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#include "lwip/def.h"
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#include "lwip/ip.h"
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#include "lwip/stats.h"
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#include "lwip/snmp.h"
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#include "lwip/dhcp.h"
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#include "lwip/autoip.h"
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#include "netif/etharp.h"
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#if PPPOE_SUPPORT
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#include "netif/ppp_oe.h"
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#endif /* PPPOE_SUPPORT */
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#include <string.h>
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const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};
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const struct eth_addr ethzero = {{0,0,0,0,0,0}};
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#if LWIP_ARP /* don't build if not configured for use in lwipopts.h */
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/** the time an ARP entry stays valid after its last update,
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* for ARP_TMR_INTERVAL = 5000, this is
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* (240 * 5) seconds = 20 minutes.
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*/
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#define ARP_MAXAGE 240
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/** the time an ARP entry stays pending after first request,
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* for ARP_TMR_INTERVAL = 5000, this is
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* (2 * 5) seconds = 10 seconds.
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*
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* @internal Keep this number at least 2, otherwise it might
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* run out instantly if the timeout occurs directly after a request.
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*/
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#define ARP_MAXPENDING 2
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#define HWTYPE_ETHERNET 1
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enum etharp_state {
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ETHARP_STATE_EMPTY = 0,
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ETHARP_STATE_PENDING,
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ETHARP_STATE_STABLE
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};
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struct etharp_entry {
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#if ARP_QUEUEING
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/** Pointer to queue of pending outgoing packets on this ARP entry. */
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struct etharp_q_entry *q;
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#endif /* ARP_QUEUEING */
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ip_addr_t ipaddr;
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struct eth_addr ethaddr;
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#if LWIP_SNMP
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struct netif *netif;
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#endif /* LWIP_SNMP */
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u8_t state;
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u8_t ctime;
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#if ETHARP_SUPPORT_STATIC_ENTRIES
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u8_t static_entry;
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#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
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};
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static struct etharp_entry arp_table[ARP_TABLE_SIZE];
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#if !LWIP_NETIF_HWADDRHINT
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static u8_t etharp_cached_entry;
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#endif /* !LWIP_NETIF_HWADDRHINT */
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/** Try hard to create a new entry - we want the IP address to appear in
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the cache (even if this means removing an active entry or so). */
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#define ETHARP_FLAG_TRY_HARD 1
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#define ETHARP_FLAG_FIND_ONLY 2
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#define ETHARP_FLAG_STATIC_ENTRY 4
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#if LWIP_NETIF_HWADDRHINT
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#define ETHARP_SET_HINT(netif, hint) if (((netif) != NULL) && ((netif)->addr_hint != NULL)) \
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*((netif)->addr_hint) = (hint);
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#else /* LWIP_NETIF_HWADDRHINT */
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#define ETHARP_SET_HINT(netif, hint) (etharp_cached_entry = (hint))
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#endif /* LWIP_NETIF_HWADDRHINT */
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static err_t update_arp_entry(struct netif *netif, ip_addr_t *ipaddr, struct eth_addr *ethaddr, u8_t flags);
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/* Some checks, instead of etharp_init(): */
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#if (LWIP_ARP && (ARP_TABLE_SIZE > 0x7f))
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#error "ARP_TABLE_SIZE must fit in an s8_t, you have to reduce it in your lwipopts.h"
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#endif
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#if ARP_QUEUEING
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/**
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* Free a complete queue of etharp entries
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*
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* @param q a qeueue of etharp_q_entry's to free
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*/
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static void
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free_etharp_q(struct etharp_q_entry *q)
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{
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struct etharp_q_entry *r;
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LWIP_ASSERT("q != NULL", q != NULL);
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LWIP_ASSERT("q->p != NULL", q->p != NULL);
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while (q) {
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r = q;
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q = q->next;
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LWIP_ASSERT("r->p != NULL", (r->p != NULL));
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pbuf_free(r->p);
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memp_free(MEMP_ARP_QUEUE, r);
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}
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}
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#endif /* ARP_QUEUEING */
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/** Clean up ARP table entries */
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static void
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free_entry(int i)
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{
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/* remove from SNMP ARP index tree */
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snmp_delete_arpidx_tree(arp_table[i].netif, &arp_table[i].ipaddr);
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#if ARP_QUEUEING
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/* and empty packet queue */
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if (arp_table[i].q != NULL) {
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/* remove all queued packets */
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LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer: freeing entry %"U16_F", packet queue %p.\n", (u16_t)i, (void *)(arp_table[i].q)));
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free_etharp_q(arp_table[i].q);
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arp_table[i].q = NULL;
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}
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#endif /* ARP_QUEUEING */
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/* recycle entry for re-use */
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arp_table[i].state = ETHARP_STATE_EMPTY;
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#if ETHARP_SUPPORT_STATIC_ENTRIES
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arp_table[i].static_entry = 0;
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#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
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#ifdef LWIP_DEBUG
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/* for debugging, clean out the complete entry */
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arp_table[i].ctime = 0;
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#if LWIP_SNMP
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arp_table[i].netif = NULL;
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#endif /* LWIP_SNMP */
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ip_addr_set_zero(&arp_table[i].ipaddr);
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arp_table[i].ethaddr = ethzero;
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#endif /* LWIP_DEBUG */
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}
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/**
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* Clears expired entries in the ARP table.
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*
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* This function should be called every ETHARP_TMR_INTERVAL milliseconds (5 seconds),
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* in order to expire entries in the ARP table.
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*/
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void
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etharp_tmr(void)
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{
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u8_t i;
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LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer\n"));
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/* remove expired entries from the ARP table */
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for (i = 0; i < ARP_TABLE_SIZE; ++i) {
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u8_t state = arp_table[i].state;
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if (state != ETHARP_STATE_EMPTY
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#if ETHARP_SUPPORT_STATIC_ENTRIES
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&& (arp_table[i].static_entry == 0)
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#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
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) {
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arp_table[i].ctime++;
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if ((arp_table[i].ctime >= ARP_MAXAGE) ||
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((arp_table[i].state == ETHARP_STATE_PENDING) &&
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(arp_table[i].ctime >= ARP_MAXPENDING))) {
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/* pending or stable entry has become old! */
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LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer: expired %s entry %"U16_F".\n",
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arp_table[i].state == ETHARP_STATE_STABLE ? "stable" : "pending", (u16_t)i));
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/* clean up entries that have just been expired */
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free_entry(i);
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}
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#if ARP_QUEUEING
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/* still pending entry? (not expired) */
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if (arp_table[i].state == ETHARP_STATE_PENDING) {
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/* resend an ARP query here? */
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}
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#endif /* ARP_QUEUEING */
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}
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}
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}
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/**
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* Search the ARP table for a matching or new entry.
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*
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* If an IP address is given, return a pending or stable ARP entry that matches
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* the address. If no match is found, create a new entry with this address set,
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* but in state ETHARP_EMPTY. The caller must check and possibly change the
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* state of the returned entry.
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*
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* If ipaddr is NULL, return a initialized new entry in state ETHARP_EMPTY.
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*
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* In all cases, attempt to create new entries from an empty entry. If no
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* empty entries are available and ETHARP_FLAG_TRY_HARD flag is set, recycle
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* old entries. Heuristic choose the least important entry for recycling.
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*
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* @param ipaddr IP address to find in ARP cache, or to add if not found.
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* @param flags @see definition of ETHARP_FLAG_*
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* @param netif netif related to this address (used for NETIF_HWADDRHINT)
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*
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* @return The ARP entry index that matched or is created, ERR_MEM if no
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* entry is found or could be recycled.
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*/
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static s8_t
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find_entry(ip_addr_t *ipaddr, u8_t flags)
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{
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s8_t old_pending = ARP_TABLE_SIZE, old_stable = ARP_TABLE_SIZE;
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s8_t empty = ARP_TABLE_SIZE;
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u8_t i = 0, age_pending = 0, age_stable = 0;
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#if ARP_QUEUEING
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/* oldest entry with packets on queue */
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s8_t old_queue = ARP_TABLE_SIZE;
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/* its age */
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u8_t age_queue = 0;
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#endif /* ARP_QUEUEING */
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/**
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* a) do a search through the cache, remember candidates
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* b) select candidate entry
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* c) create new entry
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*/
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/* a) in a single search sweep, do all of this
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* 1) remember the first empty entry (if any)
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* 2) remember the oldest stable entry (if any)
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* 3) remember the oldest pending entry without queued packets (if any)
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* 4) remember the oldest pending entry with queued packets (if any)
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* 5) search for a matching IP entry, either pending or stable
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* until 5 matches, or all entries are searched for.
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*/
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for (i = 0; i < ARP_TABLE_SIZE; ++i) {
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u8_t state = arp_table[i].state;
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/* no empty entry found yet and now we do find one? */
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if ((empty == ARP_TABLE_SIZE) && (state == ETHARP_STATE_EMPTY)) {
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LWIP_DEBUGF(ETHARP_DEBUG, ("find_entry: found empty entry %"U16_F"\n", (u16_t)i));
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/* remember first empty entry */
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empty = i;
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} else if (state != ETHARP_STATE_EMPTY) {
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LWIP_ASSERT("state == ETHARP_STATE_PENDING || state == ETHARP_STATE_STABLE",
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state == ETHARP_STATE_PENDING || state == ETHARP_STATE_STABLE);
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/* if given, does IP address match IP address in ARP entry? */
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if (ipaddr && ip_addr_cmp(ipaddr, &arp_table[i].ipaddr)) {
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LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: found matching entry %"U16_F"\n", (u16_t)i));
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/* found exact IP address match, simply bail out */
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return i;
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}
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/* pending entry? */
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if (state == ETHARP_STATE_PENDING) {
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/* pending with queued packets? */
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#if ARP_QUEUEING
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if (arp_table[i].q != NULL) {
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if (arp_table[i].ctime >= age_queue) {
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old_queue = i;
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age_queue = arp_table[i].ctime;
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}
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} else
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#endif /* ARP_QUEUEING */
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/* pending without queued packets? */
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{
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if (arp_table[i].ctime >= age_pending) {
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old_pending = i;
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age_pending = arp_table[i].ctime;
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}
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}
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/* stable entry? */
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} else if (state == ETHARP_STATE_STABLE) {
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#if ETHARP_SUPPORT_STATIC_ENTRIES
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/* don't record old_stable for static entries since they never expire */
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if (arp_table[i].static_entry == 0)
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#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
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{
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/* remember entry with oldest stable entry in oldest, its age in maxtime */
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if (arp_table[i].ctime >= age_stable) {
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old_stable = i;
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age_stable = arp_table[i].ctime;
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}
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}
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}
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}
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}
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/* { we have no match } => try to create a new entry */
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/* don't create new entry, only search? */
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if (((flags & ETHARP_FLAG_FIND_ONLY) != 0) ||
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/* or no empty entry found and not allowed to recycle? */
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((empty == ARP_TABLE_SIZE) && ((flags & ETHARP_FLAG_TRY_HARD) == 0))) {
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LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: no empty entry found and not allowed to recycle\n"));
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return (s8_t)ERR_MEM;
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}
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/* b) choose the least destructive entry to recycle:
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* 1) empty entry
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* 2) oldest stable entry
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* 3) oldest pending entry without queued packets
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* 4) oldest pending entry with queued packets
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*
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* { ETHARP_FLAG_TRY_HARD is set at this point }
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*/
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/* 1) empty entry available? */
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if (empty < ARP_TABLE_SIZE) {
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i = empty;
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LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting empty entry %"U16_F"\n", (u16_t)i));
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} else {
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/* 2) found recyclable stable entry? */
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if (old_stable < ARP_TABLE_SIZE) {
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/* recycle oldest stable*/
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i = old_stable;
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LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting oldest stable entry %"U16_F"\n", (u16_t)i));
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#if ARP_QUEUEING
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/* no queued packets should exist on stable entries */
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LWIP_ASSERT("arp_table[i].q == NULL", arp_table[i].q == NULL);
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#endif /* ARP_QUEUEING */
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/* 3) found recyclable pending entry without queued packets? */
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} else if (old_pending < ARP_TABLE_SIZE) {
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/* recycle oldest pending */
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i = old_pending;
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LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting oldest pending entry %"U16_F" (without queue)\n", (u16_t)i));
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#if ARP_QUEUEING
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/* 4) found recyclable pending entry with queued packets? */
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} else if (old_queue < ARP_TABLE_SIZE) {
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/* recycle oldest pending (queued packets are free in free_entry) */
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i = old_queue;
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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)));
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#endif /* ARP_QUEUEING */
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/* no empty or recyclable entries found */
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} else {
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LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: no empty or recyclable entries found\n"));
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return (s8_t)ERR_MEM;
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}
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/* { empty or recyclable entry found } */
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LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE);
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free_entry(i);
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}
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LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE);
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LWIP_ASSERT("arp_table[i].state == ETHARP_STATE_EMPTY",
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arp_table[i].state == ETHARP_STATE_EMPTY);
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/* IP address given? */
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if (ipaddr != NULL) {
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/* set IP address */
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ip_addr_copy(arp_table[i].ipaddr, *ipaddr);
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}
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arp_table[i].ctime = 0;
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#if ETHARP_SUPPORT_STATIC_ENTRIES
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arp_table[i].static_entry = 0;
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#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
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return (err_t)i;
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}
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/**
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* Send an IP packet on the network using netif->linkoutput
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* The ethernet header is filled in before sending.
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*
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* @params netif the lwIP network interface on which to send the packet
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* @params p the packet to send, p->payload pointing to the (uninitialized) ethernet header
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* @params src the source MAC address to be copied into the ethernet header
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* @params dst the destination MAC address to be copied into the ethernet header
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* @return ERR_OK if the packet was sent, any other err_t on failure
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*/
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static err_t
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etharp_send_ip(struct netif *netif, struct pbuf *p, struct eth_addr *src, struct eth_addr *dst)
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{
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struct eth_hdr *ethhdr = (struct eth_hdr *)p->payload;
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LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!",
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(netif->hwaddr_len == ETHARP_HWADDR_LEN));
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ETHADDR32_COPY(ðhdr->dest, dst);
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ETHADDR16_COPY(ðhdr->src, src);
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ethhdr->type = PP_HTONS(ETHTYPE_IP);
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LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_send_ip: sending packet %p\n", (void *)p));
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/* send the packet */
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return netif->linkoutput(netif, p);
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}
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/**
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* Update (or insert) a IP/MAC address pair in the ARP cache.
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*
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* If a pending entry is resolved, any queued packets will be sent
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* at this point.
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*
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* @param netif netif related to this entry (used for NETIF_ADDRHINT)
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* @param ipaddr IP address of the inserted ARP entry.
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* @param ethaddr Ethernet address of the inserted ARP entry.
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* @param flags @see definition of ETHARP_FLAG_*
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*
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* @return
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* - ERR_OK Succesfully updated ARP cache.
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* - ERR_MEM If we could not add a new ARP entry when ETHARP_FLAG_TRY_HARD was set.
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* - ERR_ARG Non-unicast address given, those will not appear in ARP cache.
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*
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* @see pbuf_free()
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|
*/
|
|
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(ðhdr->dest, ethdst_hwaddr);
|
|
#else /* LWIP_AUTOIP */
|
|
ETHADDR16_COPY(ðhdr->dest, &hdr->shwaddr);
|
|
#endif /* LWIP_AUTOIP */
|
|
ETHADDR16_COPY(&hdr->shwaddr, ethaddr);
|
|
ETHADDR16_COPY(ðhdr->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 *)ðbroadcast;
|
|
/* 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(ðhdr->dest, ethdst_hwaddr);
|
|
#else /* LWIP_AUTOIP */
|
|
ETHADDR16_COPY(ðhdr->dest, ethdst_addr);
|
|
#endif /* LWIP_AUTOIP */
|
|
ETHADDR16_COPY(ðhdr->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, ðbroadcast,
|
|
(struct eth_addr *)netif->hwaddr, &netif->ip_addr, ðzero,
|
|
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 */
|