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Adam Green / Mbed 2 deprecated WeatherStation

Web server based weather station using Sparkfun Weather Meters.

Dependencies: FatFileSystem mbed WeatherMeters SDFileSystem

NetStack/lwip/netif/etharp.c@0:616601bde9fb, 2012-02-23 (annotated)

Committer:: AdamGreen
Date:: Thu Feb 23 21:38:39 2012 +0000
Revision:: 0:616601bde9fb

Who changed what in which revision?

User	Revision	Line number	New contents of line
AdamGreen	0:616601bde9fb	1	/**
AdamGreen	0:616601bde9fb	2	* @file
AdamGreen	0:616601bde9fb	3	* Address Resolution Protocol module for IP over Ethernet
AdamGreen	0:616601bde9fb	4	*
AdamGreen	0:616601bde9fb	5	* Functionally, ARP is divided into two parts. The first maps an IP address
AdamGreen	0:616601bde9fb	6	* to a physical address when sending a packet, and the second part answers
AdamGreen	0:616601bde9fb	7	* requests from other machines for our physical address.
AdamGreen	0:616601bde9fb	8	*
AdamGreen	0:616601bde9fb	9	* This implementation complies with RFC 826 (Ethernet ARP). It supports
AdamGreen	0:616601bde9fb	10	* Gratuitious ARP from RFC3220 (IP Mobility Support for IPv4) section 4.6
AdamGreen	0:616601bde9fb	11	* if an interface calls etharp_gratuitous(our_netif) upon address change.
AdamGreen	0:616601bde9fb	12	*/
AdamGreen	0:616601bde9fb	13
AdamGreen	0:616601bde9fb	14	/*
AdamGreen	0:616601bde9fb	15	* Copyright (c) 2001-2003 Swedish Institute of Computer Science.
AdamGreen	0:616601bde9fb	16	* Copyright (c) 2003-2004 Leon Woestenberg <leon.woestenberg@axon.tv>
AdamGreen	0:616601bde9fb	17	* Copyright (c) 2003-2004 Axon Digital Design B.V., The Netherlands.
AdamGreen	0:616601bde9fb	18	* All rights reserved.
AdamGreen	0:616601bde9fb	19	*
AdamGreen	0:616601bde9fb	20	* Redistribution and use in source and binary forms, with or without modification,
AdamGreen	0:616601bde9fb	21	* are permitted provided that the following conditions are met:
AdamGreen	0:616601bde9fb	22	*
AdamGreen	0:616601bde9fb	23	* 1. Redistributions of source code must retain the above copyright notice,
AdamGreen	0:616601bde9fb	24	* this list of conditions and the following disclaimer.
AdamGreen	0:616601bde9fb	25	* 2. Redistributions in binary form must reproduce the above copyright notice,
AdamGreen	0:616601bde9fb	26	* this list of conditions and the following disclaimer in the documentation
AdamGreen	0:616601bde9fb	27	* and/or other materials provided with the distribution.
AdamGreen	0:616601bde9fb	28	* 3. The name of the author may not be used to endorse or promote products
AdamGreen	0:616601bde9fb	29	* derived from this software without specific prior written permission.
AdamGreen	0:616601bde9fb	30	*
AdamGreen	0:616601bde9fb	31	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
AdamGreen	0:616601bde9fb	32	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
AdamGreen	0:616601bde9fb	33	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
AdamGreen	0:616601bde9fb	34	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
AdamGreen	0:616601bde9fb	35	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
AdamGreen	0:616601bde9fb	36	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
AdamGreen	0:616601bde9fb	37	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
AdamGreen	0:616601bde9fb	38	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
AdamGreen	0:616601bde9fb	39	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
AdamGreen	0:616601bde9fb	40	* OF SUCH DAMAGE.
AdamGreen	0:616601bde9fb	41	*
AdamGreen	0:616601bde9fb	42	* This file is part of the lwIP TCP/IP stack.
AdamGreen	0:616601bde9fb	43	*
AdamGreen	0:616601bde9fb	44	*/
AdamGreen	0:616601bde9fb	45
AdamGreen	0:616601bde9fb	46	#include "lwip/opt.h"
AdamGreen	0:616601bde9fb	47
AdamGreen	0:616601bde9fb	48	#if LWIP_ARP \|\| LWIP_ETHERNET
AdamGreen	0:616601bde9fb	49
AdamGreen	0:616601bde9fb	50	#include "lwip/ip_addr.h"
AdamGreen	0:616601bde9fb	51	#include "lwip/def.h"
AdamGreen	0:616601bde9fb	52	#include "lwip/ip.h"
AdamGreen	0:616601bde9fb	53	#include "lwip/stats.h"
AdamGreen	0:616601bde9fb	54	#include "lwip/snmp.h"
AdamGreen	0:616601bde9fb	55	#include "lwip/dhcp.h"
AdamGreen	0:616601bde9fb	56	#include "lwip/autoip.h"
AdamGreen	0:616601bde9fb	57	#include "netif/etharp.h"
AdamGreen	0:616601bde9fb	58
AdamGreen	0:616601bde9fb	59	#if PPPOE_SUPPORT
AdamGreen	0:616601bde9fb	60	#include "netif/ppp_oe.h"
AdamGreen	0:616601bde9fb	61	#endif /* PPPOE_SUPPORT */
AdamGreen	0:616601bde9fb	62
AdamGreen	0:616601bde9fb	63	#include <string.h>
AdamGreen	0:616601bde9fb	64
AdamGreen	0:616601bde9fb	65	const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};
AdamGreen	0:616601bde9fb	66	const struct eth_addr ethzero = {{0,0,0,0,0,0}};
AdamGreen	0:616601bde9fb	67
AdamGreen	0:616601bde9fb	68	#if LWIP_ARP /* don't build if not configured for use in lwipopts.h */
AdamGreen	0:616601bde9fb	69
AdamGreen	0:616601bde9fb	70	/** the time an ARP entry stays valid after its last update,
AdamGreen	0:616601bde9fb	71	* for ARP_TMR_INTERVAL = 5000, this is
AdamGreen	0:616601bde9fb	72	* (240 * 5) seconds = 20 minutes.
AdamGreen	0:616601bde9fb	73	*/
AdamGreen	0:616601bde9fb	74	#define ARP_MAXAGE 240
AdamGreen	0:616601bde9fb	75	/** the time an ARP entry stays pending after first request,
AdamGreen	0:616601bde9fb	76	* for ARP_TMR_INTERVAL = 5000, this is
AdamGreen	0:616601bde9fb	77	* (2 * 5) seconds = 10 seconds.
AdamGreen	0:616601bde9fb	78	*
AdamGreen	0:616601bde9fb	79	* @internal Keep this number at least 2, otherwise it might
AdamGreen	0:616601bde9fb	80	* run out instantly if the timeout occurs directly after a request.
AdamGreen	0:616601bde9fb	81	*/
AdamGreen	0:616601bde9fb	82	#define ARP_MAXPENDING 2
AdamGreen	0:616601bde9fb	83
AdamGreen	0:616601bde9fb	84	#define HWTYPE_ETHERNET 1
AdamGreen	0:616601bde9fb	85
AdamGreen	0:616601bde9fb	86	enum etharp_state {
AdamGreen	0:616601bde9fb	87	ETHARP_STATE_EMPTY = 0,
AdamGreen	0:616601bde9fb	88	ETHARP_STATE_PENDING,
AdamGreen	0:616601bde9fb	89	ETHARP_STATE_STABLE
AdamGreen	0:616601bde9fb	90	};
AdamGreen	0:616601bde9fb	91
AdamGreen	0:616601bde9fb	92	struct etharp_entry {
AdamGreen	0:616601bde9fb	93	#if ARP_QUEUEING
AdamGreen	0:616601bde9fb	94	/** Pointer to queue of pending outgoing packets on this ARP entry. */
AdamGreen	0:616601bde9fb	95	struct etharp_q_entry *q;
AdamGreen	0:616601bde9fb	96	#endif /* ARP_QUEUEING */
AdamGreen	0:616601bde9fb	97	ip_addr_t ipaddr;
AdamGreen	0:616601bde9fb	98	struct eth_addr ethaddr;
AdamGreen	0:616601bde9fb	99	#if LWIP_SNMP
AdamGreen	0:616601bde9fb	100	struct netif *netif;
AdamGreen	0:616601bde9fb	101	#endif /* LWIP_SNMP */
AdamGreen	0:616601bde9fb	102	u8_t state;
AdamGreen	0:616601bde9fb	103	u8_t ctime;
AdamGreen	0:616601bde9fb	104	#if ETHARP_SUPPORT_STATIC_ENTRIES
AdamGreen	0:616601bde9fb	105	u8_t static_entry;
AdamGreen	0:616601bde9fb	106	#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
AdamGreen	0:616601bde9fb	107	};
AdamGreen	0:616601bde9fb	108
AdamGreen	0:616601bde9fb	109	static struct etharp_entry arp_table[ARP_TABLE_SIZE];
AdamGreen	0:616601bde9fb	110
AdamGreen	0:616601bde9fb	111	#if !LWIP_NETIF_HWADDRHINT
AdamGreen	0:616601bde9fb	112	static u8_t etharp_cached_entry;
AdamGreen	0:616601bde9fb	113	#endif /* !LWIP_NETIF_HWADDRHINT */
AdamGreen	0:616601bde9fb	114
AdamGreen	0:616601bde9fb	115	/** Try hard to create a new entry - we want the IP address to appear in
AdamGreen	0:616601bde9fb	116	the cache (even if this means removing an active entry or so). */
AdamGreen	0:616601bde9fb	117	#define ETHARP_FLAG_TRY_HARD 1
AdamGreen	0:616601bde9fb	118	#define ETHARP_FLAG_FIND_ONLY 2
AdamGreen	0:616601bde9fb	119	#define ETHARP_FLAG_STATIC_ENTRY 4
AdamGreen	0:616601bde9fb	120
AdamGreen	0:616601bde9fb	121	#if LWIP_NETIF_HWADDRHINT
AdamGreen	0:616601bde9fb	122	#define ETHARP_SET_HINT(netif, hint) if (((netif) != NULL) && ((netif)->addr_hint != NULL)) \
AdamGreen	0:616601bde9fb	123	*((netif)->addr_hint) = (hint);
AdamGreen	0:616601bde9fb	124	#else /* LWIP_NETIF_HWADDRHINT */
AdamGreen	0:616601bde9fb	125	#define ETHARP_SET_HINT(netif, hint) (etharp_cached_entry = (hint))
AdamGreen	0:616601bde9fb	126	#endif /* LWIP_NETIF_HWADDRHINT */
AdamGreen	0:616601bde9fb	127
AdamGreen	0:616601bde9fb	128	static err_t update_arp_entry(struct netif netif, ip_addr_t ipaddr, struct eth_addr *ethaddr, u8_t flags);
AdamGreen	0:616601bde9fb	129
AdamGreen	0:616601bde9fb	130
AdamGreen	0:616601bde9fb	131	/* Some checks, instead of etharp_init(): */
AdamGreen	0:616601bde9fb	132	#if (LWIP_ARP && (ARP_TABLE_SIZE > 0x7f))
AdamGreen	0:616601bde9fb	133	#error "ARP_TABLE_SIZE must fit in an s8_t, you have to reduce it in your lwipopts.h"
AdamGreen	0:616601bde9fb	134	#endif
AdamGreen	0:616601bde9fb	135
AdamGreen	0:616601bde9fb	136
AdamGreen	0:616601bde9fb	137	#if ARP_QUEUEING
AdamGreen	0:616601bde9fb	138	/**
AdamGreen	0:616601bde9fb	139	* Free a complete queue of etharp entries
AdamGreen	0:616601bde9fb	140	*
AdamGreen	0:616601bde9fb	141	* @param q a qeueue of etharp_q_entry's to free
AdamGreen	0:616601bde9fb	142	*/
AdamGreen	0:616601bde9fb	143	static void
AdamGreen	0:616601bde9fb	144	free_etharp_q(struct etharp_q_entry *q)
AdamGreen	0:616601bde9fb	145	{
AdamGreen	0:616601bde9fb	146	struct etharp_q_entry *r;
AdamGreen	0:616601bde9fb	147	LWIP_ASSERT("q != NULL", q != NULL);
AdamGreen	0:616601bde9fb	148	LWIP_ASSERT("q->p != NULL", q->p != NULL);
AdamGreen	0:616601bde9fb	149	while (q) {
AdamGreen	0:616601bde9fb	150	r = q;
AdamGreen	0:616601bde9fb	151	q = q->next;
AdamGreen	0:616601bde9fb	152	LWIP_ASSERT("r->p != NULL", (r->p != NULL));
AdamGreen	0:616601bde9fb	153	pbuf_free(r->p);
AdamGreen	0:616601bde9fb	154	memp_free(MEMP_ARP_QUEUE, r);
AdamGreen	0:616601bde9fb	155	}
AdamGreen	0:616601bde9fb	156	}
AdamGreen	0:616601bde9fb	157	#endif /* ARP_QUEUEING */
AdamGreen	0:616601bde9fb	158
AdamGreen	0:616601bde9fb	159	/** Clean up ARP table entries */
AdamGreen	0:616601bde9fb	160	static void
AdamGreen	0:616601bde9fb	161	free_entry(int i)
AdamGreen	0:616601bde9fb	162	{
AdamGreen	0:616601bde9fb	163	/* remove from SNMP ARP index tree */
AdamGreen	0:616601bde9fb	164	snmp_delete_arpidx_tree(arp_table[i].netif, &arp_table[i].ipaddr);
AdamGreen	0:616601bde9fb	165	#if ARP_QUEUEING
AdamGreen	0:616601bde9fb	166	/* and empty packet queue */
AdamGreen	0:616601bde9fb	167	if (arp_table[i].q != NULL) {
AdamGreen	0:616601bde9fb	168	/* remove all queued packets */
AdamGreen	0:616601bde9fb	169	LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer: freeing entry %"U16_F", packet queue %p.\n", (u16_t)i, (void *)(arp_table[i].q)));
AdamGreen	0:616601bde9fb	170	free_etharp_q(arp_table[i].q);
AdamGreen	0:616601bde9fb	171	arp_table[i].q = NULL;
AdamGreen	0:616601bde9fb	172	}
AdamGreen	0:616601bde9fb	173	#endif /* ARP_QUEUEING */
AdamGreen	0:616601bde9fb	174	/* recycle entry for re-use */
AdamGreen	0:616601bde9fb	175	arp_table[i].state = ETHARP_STATE_EMPTY;
AdamGreen	0:616601bde9fb	176	#if ETHARP_SUPPORT_STATIC_ENTRIES
AdamGreen	0:616601bde9fb	177	arp_table[i].static_entry = 0;
AdamGreen	0:616601bde9fb	178	#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
AdamGreen	0:616601bde9fb	179	#ifdef LWIP_DEBUG
AdamGreen	0:616601bde9fb	180	/* for debugging, clean out the complete entry */
AdamGreen	0:616601bde9fb	181	arp_table[i].ctime = 0;
AdamGreen	0:616601bde9fb	182	#if LWIP_SNMP
AdamGreen	0:616601bde9fb	183	arp_table[i].netif = NULL;
AdamGreen	0:616601bde9fb	184	#endif /* LWIP_SNMP */
AdamGreen	0:616601bde9fb	185	ip_addr_set_zero(&arp_table[i].ipaddr);
AdamGreen	0:616601bde9fb	186	arp_table[i].ethaddr = ethzero;
AdamGreen	0:616601bde9fb	187	#endif /* LWIP_DEBUG */
AdamGreen	0:616601bde9fb	188	}
AdamGreen	0:616601bde9fb	189
AdamGreen	0:616601bde9fb	190	/**
AdamGreen	0:616601bde9fb	191	* Clears expired entries in the ARP table.
AdamGreen	0:616601bde9fb	192	*
AdamGreen	0:616601bde9fb	193	* This function should be called every ETHARP_TMR_INTERVAL milliseconds (5 seconds),
AdamGreen	0:616601bde9fb	194	* in order to expire entries in the ARP table.
AdamGreen	0:616601bde9fb	195	*/
AdamGreen	0:616601bde9fb	196	void
AdamGreen	0:616601bde9fb	197	etharp_tmr(void)
AdamGreen	0:616601bde9fb	198	{
AdamGreen	0:616601bde9fb	199	u8_t i;
AdamGreen	0:616601bde9fb	200
AdamGreen	0:616601bde9fb	201	LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer\n"));
AdamGreen	0:616601bde9fb	202	/* remove expired entries from the ARP table */
AdamGreen	0:616601bde9fb	203	for (i = 0; i < ARP_TABLE_SIZE; ++i) {
AdamGreen	0:616601bde9fb	204	u8_t state = arp_table[i].state;
AdamGreen	0:616601bde9fb	205	if (state != ETHARP_STATE_EMPTY
AdamGreen	0:616601bde9fb	206	#if ETHARP_SUPPORT_STATIC_ENTRIES
AdamGreen	0:616601bde9fb	207	&& (arp_table[i].static_entry == 0)
AdamGreen	0:616601bde9fb	208	#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
AdamGreen	0:616601bde9fb	209	) {
AdamGreen	0:616601bde9fb	210	arp_table[i].ctime++;
AdamGreen	0:616601bde9fb	211	if ((arp_table[i].ctime >= ARP_MAXAGE) \|\|
AdamGreen	0:616601bde9fb	212	((arp_table[i].state == ETHARP_STATE_PENDING) &&
AdamGreen	0:616601bde9fb	213	(arp_table[i].ctime >= ARP_MAXPENDING))) {
AdamGreen	0:616601bde9fb	214	/* pending or stable entry has become old! */
AdamGreen	0:616601bde9fb	215	LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer: expired %s entry %"U16_F".\n",
AdamGreen	0:616601bde9fb	216	arp_table[i].state == ETHARP_STATE_STABLE ? "stable" : "pending", (u16_t)i));
AdamGreen	0:616601bde9fb	217	/* clean up entries that have just been expired */
AdamGreen	0:616601bde9fb	218	free_entry(i);
AdamGreen	0:616601bde9fb	219	}
AdamGreen	0:616601bde9fb	220	#if ARP_QUEUEING
AdamGreen	0:616601bde9fb	221	/* still pending entry? (not expired) */
AdamGreen	0:616601bde9fb	222	if (arp_table[i].state == ETHARP_STATE_PENDING) {
AdamGreen	0:616601bde9fb	223	/* resend an ARP query here? */
AdamGreen	0:616601bde9fb	224	}
AdamGreen	0:616601bde9fb	225	#endif /* ARP_QUEUEING */
AdamGreen	0:616601bde9fb	226	}
AdamGreen	0:616601bde9fb	227	}
AdamGreen	0:616601bde9fb	228	}
AdamGreen	0:616601bde9fb	229
AdamGreen	0:616601bde9fb	230	/**
AdamGreen	0:616601bde9fb	231	* Search the ARP table for a matching or new entry.
AdamGreen	0:616601bde9fb	232	*
AdamGreen	0:616601bde9fb	233	* If an IP address is given, return a pending or stable ARP entry that matches
AdamGreen	0:616601bde9fb	234	* the address. If no match is found, create a new entry with this address set,
AdamGreen	0:616601bde9fb	235	* but in state ETHARP_EMPTY. The caller must check and possibly change the
AdamGreen	0:616601bde9fb	236	* state of the returned entry.
AdamGreen	0:616601bde9fb	237	*
AdamGreen	0:616601bde9fb	238	* If ipaddr is NULL, return a initialized new entry in state ETHARP_EMPTY.
AdamGreen	0:616601bde9fb	239	*
AdamGreen	0:616601bde9fb	240	* In all cases, attempt to create new entries from an empty entry. If no
AdamGreen	0:616601bde9fb	241	* empty entries are available and ETHARP_FLAG_TRY_HARD flag is set, recycle
AdamGreen	0:616601bde9fb	242	* old entries. Heuristic choose the least important entry for recycling.
AdamGreen	0:616601bde9fb	243	*
AdamGreen	0:616601bde9fb	244	* @param ipaddr IP address to find in ARP cache, or to add if not found.
AdamGreen	0:616601bde9fb	245	* @param flags @see definition of ETHARP_FLAG_*
AdamGreen	0:616601bde9fb	246	* @param netif netif related to this address (used for NETIF_HWADDRHINT)
AdamGreen	0:616601bde9fb	247	*
AdamGreen	0:616601bde9fb	248	* @return The ARP entry index that matched or is created, ERR_MEM if no
AdamGreen	0:616601bde9fb	249	* entry is found or could be recycled.
AdamGreen	0:616601bde9fb	250	*/
AdamGreen	0:616601bde9fb	251	static s8_t
AdamGreen	0:616601bde9fb	252	find_entry(ip_addr_t *ipaddr, u8_t flags)
AdamGreen	0:616601bde9fb	253	{
AdamGreen	0:616601bde9fb	254	s8_t old_pending = ARP_TABLE_SIZE, old_stable = ARP_TABLE_SIZE;
AdamGreen	0:616601bde9fb	255	s8_t empty = ARP_TABLE_SIZE;
AdamGreen	0:616601bde9fb	256	u8_t i = 0, age_pending = 0, age_stable = 0;
AdamGreen	0:616601bde9fb	257	#if ARP_QUEUEING
AdamGreen	0:616601bde9fb	258	/* oldest entry with packets on queue */
AdamGreen	0:616601bde9fb	259	s8_t old_queue = ARP_TABLE_SIZE;
AdamGreen	0:616601bde9fb	260	/* its age */
AdamGreen	0:616601bde9fb	261	u8_t age_queue = 0;
AdamGreen	0:616601bde9fb	262	#endif /* ARP_QUEUEING */
AdamGreen	0:616601bde9fb	263
AdamGreen	0:616601bde9fb	264	/**
AdamGreen	0:616601bde9fb	265	* a) do a search through the cache, remember candidates
AdamGreen	0:616601bde9fb	266	* b) select candidate entry
AdamGreen	0:616601bde9fb	267	* c) create new entry
AdamGreen	0:616601bde9fb	268	*/
AdamGreen	0:616601bde9fb	269
AdamGreen	0:616601bde9fb	270	/* a) in a single search sweep, do all of this
AdamGreen	0:616601bde9fb	271	* 1) remember the first empty entry (if any)
AdamGreen	0:616601bde9fb	272	* 2) remember the oldest stable entry (if any)
AdamGreen	0:616601bde9fb	273	* 3) remember the oldest pending entry without queued packets (if any)
AdamGreen	0:616601bde9fb	274	* 4) remember the oldest pending entry with queued packets (if any)
AdamGreen	0:616601bde9fb	275	* 5) search for a matching IP entry, either pending or stable
AdamGreen	0:616601bde9fb	276	* until 5 matches, or all entries are searched for.
AdamGreen	0:616601bde9fb	277	*/
AdamGreen	0:616601bde9fb	278
AdamGreen	0:616601bde9fb	279	for (i = 0; i < ARP_TABLE_SIZE; ++i) {
AdamGreen	0:616601bde9fb	280	u8_t state = arp_table[i].state;
AdamGreen	0:616601bde9fb	281	/* no empty entry found yet and now we do find one? */
AdamGreen	0:616601bde9fb	282	if ((empty == ARP_TABLE_SIZE) && (state == ETHARP_STATE_EMPTY)) {
AdamGreen	0:616601bde9fb	283	LWIP_DEBUGF(ETHARP_DEBUG, ("find_entry: found empty entry %"U16_F"\n", (u16_t)i));
AdamGreen	0:616601bde9fb	284	/* remember first empty entry */
AdamGreen	0:616601bde9fb	285	empty = i;
AdamGreen	0:616601bde9fb	286	} else if (state != ETHARP_STATE_EMPTY) {
AdamGreen	0:616601bde9fb	287	LWIP_ASSERT("state == ETHARP_STATE_PENDING \|\| state == ETHARP_STATE_STABLE",
AdamGreen	0:616601bde9fb	288	state == ETHARP_STATE_PENDING \|\| state == ETHARP_STATE_STABLE);
AdamGreen	0:616601bde9fb	289	/* if given, does IP address match IP address in ARP entry? */
AdamGreen	0:616601bde9fb	290	if (ipaddr && ip_addr_cmp(ipaddr, &arp_table[i].ipaddr)) {
AdamGreen	0:616601bde9fb	291	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("find_entry: found matching entry %"U16_F"\n", (u16_t)i));
AdamGreen	0:616601bde9fb	292	/* found exact IP address match, simply bail out */
AdamGreen	0:616601bde9fb	293	return i;
AdamGreen	0:616601bde9fb	294	}
AdamGreen	0:616601bde9fb	295	/* pending entry? */
AdamGreen	0:616601bde9fb	296	if (state == ETHARP_STATE_PENDING) {
AdamGreen	0:616601bde9fb	297	/* pending with queued packets? */
AdamGreen	0:616601bde9fb	298	#if ARP_QUEUEING
AdamGreen	0:616601bde9fb	299	if (arp_table[i].q != NULL) {
AdamGreen	0:616601bde9fb	300	if (arp_table[i].ctime >= age_queue) {
AdamGreen	0:616601bde9fb	301	old_queue = i;
AdamGreen	0:616601bde9fb	302	age_queue = arp_table[i].ctime;
AdamGreen	0:616601bde9fb	303	}
AdamGreen	0:616601bde9fb	304	} else
AdamGreen	0:616601bde9fb	305	#endif /* ARP_QUEUEING */
AdamGreen	0:616601bde9fb	306	/* pending without queued packets? */
AdamGreen	0:616601bde9fb	307	{
AdamGreen	0:616601bde9fb	308	if (arp_table[i].ctime >= age_pending) {
AdamGreen	0:616601bde9fb	309	old_pending = i;
AdamGreen	0:616601bde9fb	310	age_pending = arp_table[i].ctime;
AdamGreen	0:616601bde9fb	311	}
AdamGreen	0:616601bde9fb	312	}
AdamGreen	0:616601bde9fb	313	/* stable entry? */
AdamGreen	0:616601bde9fb	314	} else if (state == ETHARP_STATE_STABLE) {
AdamGreen	0:616601bde9fb	315	#if ETHARP_SUPPORT_STATIC_ENTRIES
AdamGreen	0:616601bde9fb	316	/* don't record old_stable for static entries since they never expire */
AdamGreen	0:616601bde9fb	317	if (arp_table[i].static_entry == 0)
AdamGreen	0:616601bde9fb	318	#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
AdamGreen	0:616601bde9fb	319	{
AdamGreen	0:616601bde9fb	320	/* remember entry with oldest stable entry in oldest, its age in maxtime */
AdamGreen	0:616601bde9fb	321	if (arp_table[i].ctime >= age_stable) {
AdamGreen	0:616601bde9fb	322	old_stable = i;
AdamGreen	0:616601bde9fb	323	age_stable = arp_table[i].ctime;
AdamGreen	0:616601bde9fb	324	}
AdamGreen	0:616601bde9fb	325	}
AdamGreen	0:616601bde9fb	326	}
AdamGreen	0:616601bde9fb	327	}
AdamGreen	0:616601bde9fb	328	}
AdamGreen	0:616601bde9fb	329	/* { we have no match } => try to create a new entry */
AdamGreen	0:616601bde9fb	330
AdamGreen	0:616601bde9fb	331	/* don't create new entry, only search? */
AdamGreen	0:616601bde9fb	332	if (((flags & ETHARP_FLAG_FIND_ONLY) != 0) \|\|
AdamGreen	0:616601bde9fb	333	/* or no empty entry found and not allowed to recycle? */
AdamGreen	0:616601bde9fb	334	((empty == ARP_TABLE_SIZE) && ((flags & ETHARP_FLAG_TRY_HARD) == 0))) {
AdamGreen	0:616601bde9fb	335	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("find_entry: no empty entry found and not allowed to recycle\n"));
AdamGreen	0:616601bde9fb	336	return (s8_t)ERR_MEM;
AdamGreen	0:616601bde9fb	337	}
AdamGreen	0:616601bde9fb	338
AdamGreen	0:616601bde9fb	339	/* b) choose the least destructive entry to recycle:
AdamGreen	0:616601bde9fb	340	* 1) empty entry
AdamGreen	0:616601bde9fb	341	* 2) oldest stable entry
AdamGreen	0:616601bde9fb	342	* 3) oldest pending entry without queued packets
AdamGreen	0:616601bde9fb	343	* 4) oldest pending entry with queued packets
AdamGreen	0:616601bde9fb	344	*
AdamGreen	0:616601bde9fb	345	* { ETHARP_FLAG_TRY_HARD is set at this point }
AdamGreen	0:616601bde9fb	346	*/
AdamGreen	0:616601bde9fb	347
AdamGreen	0:616601bde9fb	348	/* 1) empty entry available? */
AdamGreen	0:616601bde9fb	349	if (empty < ARP_TABLE_SIZE) {
AdamGreen	0:616601bde9fb	350	i = empty;
AdamGreen	0:616601bde9fb	351	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("find_entry: selecting empty entry %"U16_F"\n", (u16_t)i));
AdamGreen	0:616601bde9fb	352	} else {
AdamGreen	0:616601bde9fb	353	/* 2) found recyclable stable entry? */
AdamGreen	0:616601bde9fb	354	if (old_stable < ARP_TABLE_SIZE) {
AdamGreen	0:616601bde9fb	355	/* recycle oldest stable*/
AdamGreen	0:616601bde9fb	356	i = old_stable;
AdamGreen	0:616601bde9fb	357	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("find_entry: selecting oldest stable entry %"U16_F"\n", (u16_t)i));
AdamGreen	0:616601bde9fb	358	#if ARP_QUEUEING
AdamGreen	0:616601bde9fb	359	/* no queued packets should exist on stable entries */
AdamGreen	0:616601bde9fb	360	LWIP_ASSERT("arp_table[i].q == NULL", arp_table[i].q == NULL);
AdamGreen	0:616601bde9fb	361	#endif /* ARP_QUEUEING */
AdamGreen	0:616601bde9fb	362	/* 3) found recyclable pending entry without queued packets? */
AdamGreen	0:616601bde9fb	363	} else if (old_pending < ARP_TABLE_SIZE) {
AdamGreen	0:616601bde9fb	364	/* recycle oldest pending */
AdamGreen	0:616601bde9fb	365	i = old_pending;
AdamGreen	0:616601bde9fb	366	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("find_entry: selecting oldest pending entry %"U16_F" (without queue)\n", (u16_t)i));
AdamGreen	0:616601bde9fb	367	#if ARP_QUEUEING
AdamGreen	0:616601bde9fb	368	/* 4) found recyclable pending entry with queued packets? */
AdamGreen	0:616601bde9fb	369	} else if (old_queue < ARP_TABLE_SIZE) {
AdamGreen	0:616601bde9fb	370	/* recycle oldest pending (queued packets are free in free_entry) */
AdamGreen	0:616601bde9fb	371	i = old_queue;
AdamGreen	0:616601bde9fb	372	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)));
AdamGreen	0:616601bde9fb	373	#endif /* ARP_QUEUEING */
AdamGreen	0:616601bde9fb	374	/* no empty or recyclable entries found */
AdamGreen	0:616601bde9fb	375	} else {
AdamGreen	0:616601bde9fb	376	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("find_entry: no empty or recyclable entries found\n"));
AdamGreen	0:616601bde9fb	377	return (s8_t)ERR_MEM;
AdamGreen	0:616601bde9fb	378	}
AdamGreen	0:616601bde9fb	379
AdamGreen	0:616601bde9fb	380	/* { empty or recyclable entry found } */
AdamGreen	0:616601bde9fb	381	LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE);
AdamGreen	0:616601bde9fb	382	free_entry(i);
AdamGreen	0:616601bde9fb	383	}
AdamGreen	0:616601bde9fb	384
AdamGreen	0:616601bde9fb	385	LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE);
AdamGreen	0:616601bde9fb	386	LWIP_ASSERT("arp_table[i].state == ETHARP_STATE_EMPTY",
AdamGreen	0:616601bde9fb	387	arp_table[i].state == ETHARP_STATE_EMPTY);
AdamGreen	0:616601bde9fb	388
AdamGreen	0:616601bde9fb	389	/* IP address given? */
AdamGreen	0:616601bde9fb	390	if (ipaddr != NULL) {
AdamGreen	0:616601bde9fb	391	/* set IP address */
AdamGreen	0:616601bde9fb	392	ip_addr_copy(arp_table[i].ipaddr, *ipaddr);
AdamGreen	0:616601bde9fb	393	}
AdamGreen	0:616601bde9fb	394	arp_table[i].ctime = 0;
AdamGreen	0:616601bde9fb	395	#if ETHARP_SUPPORT_STATIC_ENTRIES
AdamGreen	0:616601bde9fb	396	arp_table[i].static_entry = 0;
AdamGreen	0:616601bde9fb	397	#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
AdamGreen	0:616601bde9fb	398	return (err_t)i;
AdamGreen	0:616601bde9fb	399	}
AdamGreen	0:616601bde9fb	400
AdamGreen	0:616601bde9fb	401	/**
AdamGreen	0:616601bde9fb	402	* Send an IP packet on the network using netif->linkoutput
AdamGreen	0:616601bde9fb	403	* The ethernet header is filled in before sending.
AdamGreen	0:616601bde9fb	404	*
AdamGreen	0:616601bde9fb	405	* @params netif the lwIP network interface on which to send the packet
AdamGreen	0:616601bde9fb	406	* @params p the packet to send, p->payload pointing to the (uninitialized) ethernet header
AdamGreen	0:616601bde9fb	407	* @params src the source MAC address to be copied into the ethernet header
AdamGreen	0:616601bde9fb	408	* @params dst the destination MAC address to be copied into the ethernet header
AdamGreen	0:616601bde9fb	409	* @return ERR_OK if the packet was sent, any other err_t on failure
AdamGreen	0:616601bde9fb	410	*/
AdamGreen	0:616601bde9fb	411	static err_t
AdamGreen	0:616601bde9fb	412	etharp_send_ip(struct netif netif, struct pbuf p, struct eth_addr src, struct eth_addr dst)
AdamGreen	0:616601bde9fb	413	{
AdamGreen	0:616601bde9fb	414	struct eth_hdr ethhdr = (struct eth_hdr )p->payload;
AdamGreen	0:616601bde9fb	415
AdamGreen	0:616601bde9fb	416	LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!",
AdamGreen	0:616601bde9fb	417	(netif->hwaddr_len == ETHARP_HWADDR_LEN));
AdamGreen	0:616601bde9fb	418	ETHADDR32_COPY(&ethhdr->dest, dst);
AdamGreen	0:616601bde9fb	419	ETHADDR16_COPY(&ethhdr->src, src);
AdamGreen	0:616601bde9fb	420	ethhdr->type = PP_HTONS(ETHTYPE_IP);
AdamGreen	0:616601bde9fb	421	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_send_ip: sending packet %p\n", (void *)p));
AdamGreen	0:616601bde9fb	422	/* send the packet */
AdamGreen	0:616601bde9fb	423	return netif->linkoutput(netif, p);
AdamGreen	0:616601bde9fb	424	}
AdamGreen	0:616601bde9fb	425
AdamGreen	0:616601bde9fb	426	/**
AdamGreen	0:616601bde9fb	427	* Update (or insert) a IP/MAC address pair in the ARP cache.
AdamGreen	0:616601bde9fb	428	*
AdamGreen	0:616601bde9fb	429	* If a pending entry is resolved, any queued packets will be sent
AdamGreen	0:616601bde9fb	430	* at this point.
AdamGreen	0:616601bde9fb	431	*
AdamGreen	0:616601bde9fb	432	* @param netif netif related to this entry (used for NETIF_ADDRHINT)
AdamGreen	0:616601bde9fb	433	* @param ipaddr IP address of the inserted ARP entry.
AdamGreen	0:616601bde9fb	434	* @param ethaddr Ethernet address of the inserted ARP entry.
AdamGreen	0:616601bde9fb	435	* @param flags @see definition of ETHARP_FLAG_*
AdamGreen	0:616601bde9fb	436	*
AdamGreen	0:616601bde9fb	437	* @return
AdamGreen	0:616601bde9fb	438	* - ERR_OK Succesfully updated ARP cache.
AdamGreen	0:616601bde9fb	439	* - ERR_MEM If we could not add a new ARP entry when ETHARP_FLAG_TRY_HARD was set.
AdamGreen	0:616601bde9fb	440	* - ERR_ARG Non-unicast address given, those will not appear in ARP cache.
AdamGreen	0:616601bde9fb	441	*
AdamGreen	0:616601bde9fb	442	* @see pbuf_free()
AdamGreen	0:616601bde9fb	443	*/
AdamGreen	0:616601bde9fb	444	static err_t
AdamGreen	0:616601bde9fb	445	update_arp_entry(struct netif netif, ip_addr_t ipaddr, struct eth_addr *ethaddr, u8_t flags)
AdamGreen	0:616601bde9fb	446	{
AdamGreen	0:616601bde9fb	447	s8_t i;
AdamGreen	0:616601bde9fb	448	LWIP_ASSERT("netif->hwaddr_len == ETHARP_HWADDR_LEN", netif->hwaddr_len == ETHARP_HWADDR_LEN);
AdamGreen	0:616601bde9fb	449	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",
AdamGreen	0:616601bde9fb	450	ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr),
AdamGreen	0:616601bde9fb	451	ethaddr->addr[0], ethaddr->addr[1], ethaddr->addr[2],
AdamGreen	0:616601bde9fb	452	ethaddr->addr[3], ethaddr->addr[4], ethaddr->addr[5]));
AdamGreen	0:616601bde9fb	453	/* non-unicast address? */
AdamGreen	0:616601bde9fb	454	if (ip_addr_isany(ipaddr) \|\|
AdamGreen	0:616601bde9fb	455	ip_addr_isbroadcast(ipaddr, netif) \|\|
AdamGreen	0:616601bde9fb	456	ip_addr_ismulticast(ipaddr)) {
AdamGreen	0:616601bde9fb	457	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("update_arp_entry: will not add non-unicast IP address to ARP cache\n"));
AdamGreen	0:616601bde9fb	458	return ERR_ARG;
AdamGreen	0:616601bde9fb	459	}
AdamGreen	0:616601bde9fb	460	/* find or create ARP entry */
AdamGreen	0:616601bde9fb	461	i = find_entry(ipaddr, flags);
AdamGreen	0:616601bde9fb	462	/* bail out if no entry could be found */
AdamGreen	0:616601bde9fb	463	if (i < 0) {
AdamGreen	0:616601bde9fb	464	return (err_t)i;
AdamGreen	0:616601bde9fb	465	}
AdamGreen	0:616601bde9fb	466
AdamGreen	0:616601bde9fb	467	#if ETHARP_SUPPORT_STATIC_ENTRIES
AdamGreen	0:616601bde9fb	468	if (flags & ETHARP_FLAG_STATIC_ENTRY) {
AdamGreen	0:616601bde9fb	469	/* record static type */
AdamGreen	0:616601bde9fb	470	arp_table[i].static_entry = 1;
AdamGreen	0:616601bde9fb	471	}
AdamGreen	0:616601bde9fb	472	#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
AdamGreen	0:616601bde9fb	473
AdamGreen	0:616601bde9fb	474	/* mark it stable */
AdamGreen	0:616601bde9fb	475	arp_table[i].state = ETHARP_STATE_STABLE;
AdamGreen	0:616601bde9fb	476
AdamGreen	0:616601bde9fb	477	#if LWIP_SNMP
AdamGreen	0:616601bde9fb	478	/* record network interface */
AdamGreen	0:616601bde9fb	479	arp_table[i].netif = netif;
AdamGreen	0:616601bde9fb	480	#endif /* LWIP_SNMP */
AdamGreen	0:616601bde9fb	481	/* insert in SNMP ARP index tree */
AdamGreen	0:616601bde9fb	482	snmp_insert_arpidx_tree(netif, &arp_table[i].ipaddr);
AdamGreen	0:616601bde9fb	483
AdamGreen	0:616601bde9fb	484	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("update_arp_entry: updating stable entry %"S16_F"\n", (s16_t)i));
AdamGreen	0:616601bde9fb	485	/* update address */
AdamGreen	0:616601bde9fb	486	ETHADDR32_COPY(&arp_table[i].ethaddr, ethaddr);
AdamGreen	0:616601bde9fb	487	/* reset time stamp */
AdamGreen	0:616601bde9fb	488	arp_table[i].ctime = 0;
AdamGreen	0:616601bde9fb	489	#if ARP_QUEUEING
AdamGreen	0:616601bde9fb	490	/* this is where we will send out queued packets! */
AdamGreen	0:616601bde9fb	491	while (arp_table[i].q != NULL) {
AdamGreen	0:616601bde9fb	492	struct pbuf *p;
AdamGreen	0:616601bde9fb	493	/* remember remainder of queue */
AdamGreen	0:616601bde9fb	494	struct etharp_q_entry *q = arp_table[i].q;
AdamGreen	0:616601bde9fb	495	/* pop first item off the queue */
AdamGreen	0:616601bde9fb	496	arp_table[i].q = q->next;
AdamGreen	0:616601bde9fb	497	/* get the packet pointer */
AdamGreen	0:616601bde9fb	498	p = q->p;
AdamGreen	0:616601bde9fb	499	/* now queue entry can be freed */
AdamGreen	0:616601bde9fb	500	memp_free(MEMP_ARP_QUEUE, q);
AdamGreen	0:616601bde9fb	501	/* send the queued IP packet */
AdamGreen	0:616601bde9fb	502	etharp_send_ip(netif, p, (struct eth_addr*)(netif->hwaddr), ethaddr);
AdamGreen	0:616601bde9fb	503	/* free the queued IP packet */
AdamGreen	0:616601bde9fb	504	pbuf_free(p);
AdamGreen	0:616601bde9fb	505	}
AdamGreen	0:616601bde9fb	506	#endif /* ARP_QUEUEING */
AdamGreen	0:616601bde9fb	507	return ERR_OK;
AdamGreen	0:616601bde9fb	508	}
AdamGreen	0:616601bde9fb	509
AdamGreen	0:616601bde9fb	510	#if ETHARP_SUPPORT_STATIC_ENTRIES
AdamGreen	0:616601bde9fb	511	/** Add a new static entry to the ARP table. If an entry exists for the
AdamGreen	0:616601bde9fb	512	* specified IP address, this entry is overwritten.
AdamGreen	0:616601bde9fb	513	* If packets are queued for the specified IP address, they are sent out.
AdamGreen	0:616601bde9fb	514	*
AdamGreen	0:616601bde9fb	515	* @param ipaddr IP address for the new static entry
AdamGreen	0:616601bde9fb	516	* @param ethaddr ethernet address for the new static entry
AdamGreen	0:616601bde9fb	517	* @return @see return values of etharp_add_static_entry
AdamGreen	0:616601bde9fb	518	*/
AdamGreen	0:616601bde9fb	519	err_t
AdamGreen	0:616601bde9fb	520	etharp_add_static_entry(ip_addr_t ipaddr, struct eth_addr ethaddr)
AdamGreen	0:616601bde9fb	521	{
AdamGreen	0:616601bde9fb	522	struct netif *netif;
AdamGreen	0:616601bde9fb	523	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",
AdamGreen	0:616601bde9fb	524	ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr),
AdamGreen	0:616601bde9fb	525	ethaddr->addr[0], ethaddr->addr[1], ethaddr->addr[2],
AdamGreen	0:616601bde9fb	526	ethaddr->addr[3], ethaddr->addr[4], ethaddr->addr[5]));
AdamGreen	0:616601bde9fb	527
AdamGreen	0:616601bde9fb	528	netif = ip_route(ipaddr);
AdamGreen	0:616601bde9fb	529	if (netif == NULL) {
AdamGreen	0:616601bde9fb	530	return ERR_RTE;
AdamGreen	0:616601bde9fb	531	}
AdamGreen	0:616601bde9fb	532
AdamGreen	0:616601bde9fb	533	return update_arp_entry(netif, ipaddr, ethaddr, ETHARP_FLAG_TRY_HARD \| ETHARP_FLAG_STATIC_ENTRY);
AdamGreen	0:616601bde9fb	534	}
AdamGreen	0:616601bde9fb	535
AdamGreen	0:616601bde9fb	536	/** Remove a static entry from the ARP table previously added with a call to
AdamGreen	0:616601bde9fb	537	* etharp_add_static_entry.
AdamGreen	0:616601bde9fb	538	*
AdamGreen	0:616601bde9fb	539	* @param ipaddr IP address of the static entry to remove
AdamGreen	0:616601bde9fb	540	* @return ERR_OK: entry removed
AdamGreen	0:616601bde9fb	541	* ERR_MEM: entry wasn't found
AdamGreen	0:616601bde9fb	542	* ERR_ARG: entry wasn't a static entry but a dynamic one
AdamGreen	0:616601bde9fb	543	*/
AdamGreen	0:616601bde9fb	544	err_t
AdamGreen	0:616601bde9fb	545	etharp_remove_static_entry(ip_addr_t *ipaddr)
AdamGreen	0:616601bde9fb	546	{
AdamGreen	0:616601bde9fb	547	s8_t i;
AdamGreen	0:616601bde9fb	548	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_remove_static_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
AdamGreen	0:616601bde9fb	549	ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr)));
AdamGreen	0:616601bde9fb	550
AdamGreen	0:616601bde9fb	551	/* find or create ARP entry */
AdamGreen	0:616601bde9fb	552	i = find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY);
AdamGreen	0:616601bde9fb	553	/* bail out if no entry could be found */
AdamGreen	0:616601bde9fb	554	if (i < 0) {
AdamGreen	0:616601bde9fb	555	return (err_t)i;
AdamGreen	0:616601bde9fb	556	}
AdamGreen	0:616601bde9fb	557
AdamGreen	0:616601bde9fb	558	if ((arp_table[i].state != ETHARP_STATE_STABLE) \|\|
AdamGreen	0:616601bde9fb	559	(arp_table[i].static_entry == 0)) {
AdamGreen	0:616601bde9fb	560	/* entry wasn't a static entry, cannot remove it */
AdamGreen	0:616601bde9fb	561	return ERR_ARG;
AdamGreen	0:616601bde9fb	562	}
AdamGreen	0:616601bde9fb	563	/* entry found, free it */
AdamGreen	0:616601bde9fb	564	free_entry(i);
AdamGreen	0:616601bde9fb	565	return ERR_OK;
AdamGreen	0:616601bde9fb	566	}
AdamGreen	0:616601bde9fb	567	#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
AdamGreen	0:616601bde9fb	568
AdamGreen	0:616601bde9fb	569	/**
AdamGreen	0:616601bde9fb	570	* Finds (stable) ethernet/IP address pair from ARP table
AdamGreen	0:616601bde9fb	571	* using interface and IP address index.
AdamGreen	0:616601bde9fb	572	* @note the addresses in the ARP table are in network order!
AdamGreen	0:616601bde9fb	573	*
AdamGreen	0:616601bde9fb	574	* @param netif points to interface index
AdamGreen	0:616601bde9fb	575	* @param ipaddr points to the (network order) IP address index
AdamGreen	0:616601bde9fb	576	* @param eth_ret points to return pointer
AdamGreen	0:616601bde9fb	577	* @param ip_ret points to return pointer
AdamGreen	0:616601bde9fb	578	* @return table index if found, -1 otherwise
AdamGreen	0:616601bde9fb	579	*/
AdamGreen	0:616601bde9fb	580	s8_t
AdamGreen	0:616601bde9fb	581	etharp_find_addr(struct netif netif, ip_addr_t ipaddr,
AdamGreen	0:616601bde9fb	582	struct eth_addr eth_ret, ip_addr_t ip_ret)
AdamGreen	0:616601bde9fb	583	{
AdamGreen	0:616601bde9fb	584	s8_t i;
AdamGreen	0:616601bde9fb	585
AdamGreen	0:616601bde9fb	586	LWIP_ASSERT("eth_ret != NULL && ip_ret != NULL",
AdamGreen	0:616601bde9fb	587	eth_ret != NULL && ip_ret != NULL);
AdamGreen	0:616601bde9fb	588
AdamGreen	0:616601bde9fb	589	LWIP_UNUSED_ARG(netif);
AdamGreen	0:616601bde9fb	590
AdamGreen	0:616601bde9fb	591	i = find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY);
AdamGreen	0:616601bde9fb	592	if((i >= 0) && arp_table[i].state == ETHARP_STATE_STABLE) {
AdamGreen	0:616601bde9fb	593	*eth_ret = &arp_table[i].ethaddr;
AdamGreen	0:616601bde9fb	594	*ip_ret = &arp_table[i].ipaddr;
AdamGreen	0:616601bde9fb	595	return i;
AdamGreen	0:616601bde9fb	596	}
AdamGreen	0:616601bde9fb	597	return -1;
AdamGreen	0:616601bde9fb	598	}
AdamGreen	0:616601bde9fb	599
AdamGreen	0:616601bde9fb	600	#if ETHARP_TRUST_IP_MAC
AdamGreen	0:616601bde9fb	601	/**
AdamGreen	0:616601bde9fb	602	* Updates the ARP table using the given IP packet.
AdamGreen	0:616601bde9fb	603	*
AdamGreen	0:616601bde9fb	604	* Uses the incoming IP packet's source address to update the
AdamGreen	0:616601bde9fb	605	* ARP cache for the local network. The function does not alter
AdamGreen	0:616601bde9fb	606	* or free the packet. This function must be called before the
AdamGreen	0:616601bde9fb	607	* packet p is passed to the IP layer.
AdamGreen	0:616601bde9fb	608	*
AdamGreen	0:616601bde9fb	609	* @param netif The lwIP network interface on which the IP packet pbuf arrived.
AdamGreen	0:616601bde9fb	610	* @param p The IP packet that arrived on netif.
AdamGreen	0:616601bde9fb	611	*
AdamGreen	0:616601bde9fb	612	* @return NULL
AdamGreen	0:616601bde9fb	613	*
AdamGreen	0:616601bde9fb	614	* @see pbuf_free()
AdamGreen	0:616601bde9fb	615	*/
AdamGreen	0:616601bde9fb	616	static void
AdamGreen	0:616601bde9fb	617	etharp_ip_input(struct netif netif, struct pbuf p)
AdamGreen	0:616601bde9fb	618	{
AdamGreen	0:616601bde9fb	619	struct eth_hdr *ethhdr;
AdamGreen	0:616601bde9fb	620	struct ip_hdr *iphdr;
AdamGreen	0:616601bde9fb	621	ip_addr_t iphdr_src;
AdamGreen	0:616601bde9fb	622	LWIP_ERROR("netif != NULL", (netif != NULL), return;);
AdamGreen	0:616601bde9fb	623
AdamGreen	0:616601bde9fb	624	/* Only insert an entry if the source IP address of the
AdamGreen	0:616601bde9fb	625	incoming IP packet comes from a host on the local network. */
AdamGreen	0:616601bde9fb	626	ethhdr = (struct eth_hdr *)p->payload;
AdamGreen	0:616601bde9fb	627	iphdr = (struct ip_hdr )((u8_t)ethhdr + SIZEOF_ETH_HDR);
AdamGreen	0:616601bde9fb	628	#if ETHARP_SUPPORT_VLAN
AdamGreen	0:616601bde9fb	629	if (ethhdr->type == ETHTYPE_VLAN) {
AdamGreen	0:616601bde9fb	630	iphdr = (struct ip_hdr )((u8_t)ethhdr + SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR);
AdamGreen	0:616601bde9fb	631	}
AdamGreen	0:616601bde9fb	632	#endif /* ETHARP_SUPPORT_VLAN */
AdamGreen	0:616601bde9fb	633
AdamGreen	0:616601bde9fb	634	ip_addr_copy(iphdr_src, iphdr->src);
AdamGreen	0:616601bde9fb	635
AdamGreen	0:616601bde9fb	636	/* source is not on the local network? */
AdamGreen	0:616601bde9fb	637	if (!ip_addr_netcmp(&iphdr_src, &(netif->ip_addr), &(netif->netmask))) {
AdamGreen	0:616601bde9fb	638	/* do nothing */
AdamGreen	0:616601bde9fb	639	return;
AdamGreen	0:616601bde9fb	640	}
AdamGreen	0:616601bde9fb	641
AdamGreen	0:616601bde9fb	642	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_ip_input: updating ETHARP table.\n"));
AdamGreen	0:616601bde9fb	643	/* update the source IP address in the cache, if present */
AdamGreen	0:616601bde9fb	644	/* @todo We could use ETHARP_FLAG_TRY_HARD if we think we are going to talk
AdamGreen	0:616601bde9fb	645	* back soon (for example, if the destination IP address is ours. */
AdamGreen	0:616601bde9fb	646	update_arp_entry(netif, &iphdr_src, &(ethhdr->src), ETHARP_FLAG_FIND_ONLY);
AdamGreen	0:616601bde9fb	647	}
AdamGreen	0:616601bde9fb	648	#endif /* ETHARP_TRUST_IP_MAC */
AdamGreen	0:616601bde9fb	649
AdamGreen	0:616601bde9fb	650	/**
AdamGreen	0:616601bde9fb	651	* Responds to ARP requests to us. Upon ARP replies to us, add entry to cache
AdamGreen	0:616601bde9fb	652	* send out queued IP packets. Updates cache with snooped address pairs.
AdamGreen	0:616601bde9fb	653	*
AdamGreen	0:616601bde9fb	654	* Should be called for incoming ARP packets. The pbuf in the argument
AdamGreen	0:616601bde9fb	655	* is freed by this function.
AdamGreen	0:616601bde9fb	656	*
AdamGreen	0:616601bde9fb	657	* @param netif The lwIP network interface on which the ARP packet pbuf arrived.
AdamGreen	0:616601bde9fb	658	* @param ethaddr Ethernet address of netif.
AdamGreen	0:616601bde9fb	659	* @param p The ARP packet that arrived on netif. Is freed by this function.
AdamGreen	0:616601bde9fb	660	*
AdamGreen	0:616601bde9fb	661	* @return NULL
AdamGreen	0:616601bde9fb	662	*
AdamGreen	0:616601bde9fb	663	* @see pbuf_free()
AdamGreen	0:616601bde9fb	664	*/
AdamGreen	0:616601bde9fb	665	static void
AdamGreen	0:616601bde9fb	666	etharp_arp_input(struct netif netif, struct eth_addr ethaddr, struct pbuf *p)
AdamGreen	0:616601bde9fb	667	{
AdamGreen	0:616601bde9fb	668	struct etharp_hdr *hdr;
AdamGreen	0:616601bde9fb	669	struct eth_hdr *ethhdr;
AdamGreen	0:616601bde9fb	670	/* these are aligned properly, whereas the ARP header fields might not be */
AdamGreen	0:616601bde9fb	671	ip_addr_t sipaddr, dipaddr;
AdamGreen	0:616601bde9fb	672	u8_t for_us;
AdamGreen	0:616601bde9fb	673	#if LWIP_AUTOIP
AdamGreen	0:616601bde9fb	674	const u8_t * ethdst_hwaddr;
AdamGreen	0:616601bde9fb	675	#endif /* LWIP_AUTOIP */
AdamGreen	0:616601bde9fb	676
AdamGreen	0:616601bde9fb	677	LWIP_ERROR("netif != NULL", (netif != NULL), return;);
AdamGreen	0:616601bde9fb	678
AdamGreen	0:616601bde9fb	679	/* drop short ARP packets: we have to check for p->len instead of p->tot_len here
AdamGreen	0:616601bde9fb	680	since a struct etharp_hdr is pointed to p->payload, so it musn't be chained! */
AdamGreen	0:616601bde9fb	681	if (p->len < SIZEOF_ETHARP_PACKET) {
AdamGreen	0:616601bde9fb	682	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE \| LWIP_DBG_LEVEL_WARNING,
AdamGreen	0:616601bde9fb	683	("etharp_arp_input: packet dropped, too short (%"S16_F"/%"S16_F")\n", p->tot_len,
AdamGreen	0:616601bde9fb	684	(s16_t)SIZEOF_ETHARP_PACKET));
AdamGreen	0:616601bde9fb	685	ETHARP_STATS_INC(etharp.lenerr);
AdamGreen	0:616601bde9fb	686	ETHARP_STATS_INC(etharp.drop);
AdamGreen	0:616601bde9fb	687	pbuf_free(p);
AdamGreen	0:616601bde9fb	688	return;
AdamGreen	0:616601bde9fb	689	}
AdamGreen	0:616601bde9fb	690
AdamGreen	0:616601bde9fb	691	ethhdr = (struct eth_hdr *)p->payload;
AdamGreen	0:616601bde9fb	692	hdr = (struct etharp_hdr )((u8_t)ethhdr + SIZEOF_ETH_HDR);
AdamGreen	0:616601bde9fb	693	#if ETHARP_SUPPORT_VLAN
AdamGreen	0:616601bde9fb	694	if (ethhdr->type == ETHTYPE_VLAN) {
AdamGreen	0:616601bde9fb	695	hdr = (struct etharp_hdr )(((u8_t)ethhdr) + SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR);
AdamGreen	0:616601bde9fb	696	}
AdamGreen	0:616601bde9fb	697	#endif /* ETHARP_SUPPORT_VLAN */
AdamGreen	0:616601bde9fb	698
AdamGreen	0:616601bde9fb	699	/* RFC 826 "Packet Reception": */
AdamGreen	0:616601bde9fb	700	if ((hdr->hwtype != PP_HTONS(HWTYPE_ETHERNET)) \|\|
AdamGreen	0:616601bde9fb	701	(hdr->hwlen != ETHARP_HWADDR_LEN) \|\|
AdamGreen	0:616601bde9fb	702	(hdr->protolen != sizeof(ip_addr_t)) \|\|
AdamGreen	0:616601bde9fb	703	(hdr->proto != PP_HTONS(ETHTYPE_IP)) \|\|
AdamGreen	0:616601bde9fb	704	(ethhdr->type != PP_HTONS(ETHTYPE_ARP))) {
AdamGreen	0:616601bde9fb	705	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE \| LWIP_DBG_LEVEL_WARNING,
AdamGreen	0:616601bde9fb	706	("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",
AdamGreen	0:616601bde9fb	707	hdr->hwtype, hdr->hwlen, hdr->proto, hdr->protolen, ethhdr->type));
AdamGreen	0:616601bde9fb	708	ETHARP_STATS_INC(etharp.proterr);
AdamGreen	0:616601bde9fb	709	ETHARP_STATS_INC(etharp.drop);
AdamGreen	0:616601bde9fb	710	pbuf_free(p);
AdamGreen	0:616601bde9fb	711	return;
AdamGreen	0:616601bde9fb	712	}
AdamGreen	0:616601bde9fb	713	ETHARP_STATS_INC(etharp.recv);
AdamGreen	0:616601bde9fb	714
AdamGreen	0:616601bde9fb	715	#if LWIP_AUTOIP
AdamGreen	0:616601bde9fb	716	/* We have to check if a host already has configured our random
AdamGreen	0:616601bde9fb	717	* created link local address and continously check if there is
AdamGreen	0:616601bde9fb	718	* a host with this IP-address so we can detect collisions */
AdamGreen	0:616601bde9fb	719	autoip_arp_reply(netif, hdr);
AdamGreen	0:616601bde9fb	720	#endif /* LWIP_AUTOIP */
AdamGreen	0:616601bde9fb	721
AdamGreen	0:616601bde9fb	722	/* Copy struct ip_addr2 to aligned ip_addr, to support compilers without
AdamGreen	0:616601bde9fb	723	* structure packing (not using structure copy which breaks strict-aliasing rules). */
AdamGreen	0:616601bde9fb	724	IPADDR2_COPY(&sipaddr, &hdr->sipaddr);
AdamGreen	0:616601bde9fb	725	IPADDR2_COPY(&dipaddr, &hdr->dipaddr);
AdamGreen	0:616601bde9fb	726
AdamGreen	0:616601bde9fb	727	/* this interface is not configured? */
AdamGreen	0:616601bde9fb	728	if (ip_addr_isany(&netif->ip_addr)) {
AdamGreen	0:616601bde9fb	729	for_us = 0;
AdamGreen	0:616601bde9fb	730	} else {
AdamGreen	0:616601bde9fb	731	/* ARP packet directed to us? */
AdamGreen	0:616601bde9fb	732	for_us = (u8_t)ip_addr_cmp(&dipaddr, &(netif->ip_addr));
AdamGreen	0:616601bde9fb	733	}
AdamGreen	0:616601bde9fb	734
AdamGreen	0:616601bde9fb	735	/* ARP message directed to us?
AdamGreen	0:616601bde9fb	736	-> add IP address in ARP cache; assume requester wants to talk to us,
AdamGreen	0:616601bde9fb	737	can result in directly sending the queued packets for this host.
AdamGreen	0:616601bde9fb	738	ARP message not directed to us?
AdamGreen	0:616601bde9fb	739	-> update the source IP address in the cache, if present */
AdamGreen	0:616601bde9fb	740	update_arp_entry(netif, &sipaddr, &(hdr->shwaddr),
AdamGreen	0:616601bde9fb	741	for_us ? ETHARP_FLAG_TRY_HARD : ETHARP_FLAG_FIND_ONLY);
AdamGreen	0:616601bde9fb	742
AdamGreen	0:616601bde9fb	743	/* now act on the message itself */
AdamGreen	0:616601bde9fb	744	switch (hdr->opcode) {
AdamGreen	0:616601bde9fb	745	/* ARP request? */
AdamGreen	0:616601bde9fb	746	case PP_HTONS(ARP_REQUEST):
AdamGreen	0:616601bde9fb	747	/* ARP request. If it asked for our address, we send out a
AdamGreen	0:616601bde9fb	748	* reply. In any case, we time-stamp any existing ARP entry,
AdamGreen	0:616601bde9fb	749	* and possiby send out an IP packet that was queued on it. */
AdamGreen	0:616601bde9fb	750
AdamGreen	0:616601bde9fb	751	LWIP_DEBUGF (ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_arp_input: incoming ARP request\n"));
AdamGreen	0:616601bde9fb	752	/* ARP request for our address? */
AdamGreen	0:616601bde9fb	753	if (for_us) {
AdamGreen	0:616601bde9fb	754
AdamGreen	0:616601bde9fb	755	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_arp_input: replying to ARP request for our IP address\n"));
AdamGreen	0:616601bde9fb	756	/* Re-use pbuf to send ARP reply.
AdamGreen	0:616601bde9fb	757	Since we are re-using an existing pbuf, we can't call etharp_raw since
AdamGreen	0:616601bde9fb	758	that would allocate a new pbuf. */
AdamGreen	0:616601bde9fb	759	hdr->opcode = htons(ARP_REPLY);
AdamGreen	0:616601bde9fb	760
AdamGreen	0:616601bde9fb	761	IPADDR2_COPY(&hdr->dipaddr, &hdr->sipaddr);
AdamGreen	0:616601bde9fb	762	IPADDR2_COPY(&hdr->sipaddr, &netif->ip_addr);
AdamGreen	0:616601bde9fb	763
AdamGreen	0:616601bde9fb	764	LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!",
AdamGreen	0:616601bde9fb	765	(netif->hwaddr_len == ETHARP_HWADDR_LEN));
AdamGreen	0:616601bde9fb	766	#if LWIP_AUTOIP
AdamGreen	0:616601bde9fb	767	/* If we are using Link-Local, all ARP packets that contain a Link-Local
AdamGreen	0:616601bde9fb	768	* 'sender IP address' MUST be sent using link-layer broadcast instead of
AdamGreen	0:616601bde9fb	769	* link-layer unicast. (See RFC3927 Section 2.5, last paragraph) */
AdamGreen	0:616601bde9fb	770	ethdst_hwaddr = ip_addr_islinklocal(&netif->ip_addr) ? (u8_t*)(ethbroadcast.addr) : hdr->shwaddr.addr;
AdamGreen	0:616601bde9fb	771	#endif /* LWIP_AUTOIP */
AdamGreen	0:616601bde9fb	772
AdamGreen	0:616601bde9fb	773	ETHADDR16_COPY(&hdr->dhwaddr, &hdr->shwaddr);
AdamGreen	0:616601bde9fb	774	#if LWIP_AUTOIP
AdamGreen	0:616601bde9fb	775	ETHADDR16_COPY(&ethhdr->dest, ethdst_hwaddr);
AdamGreen	0:616601bde9fb	776	#else /* LWIP_AUTOIP */
AdamGreen	0:616601bde9fb	777	ETHADDR16_COPY(&ethhdr->dest, &hdr->shwaddr);
AdamGreen	0:616601bde9fb	778	#endif /* LWIP_AUTOIP */
AdamGreen	0:616601bde9fb	779	ETHADDR16_COPY(&hdr->shwaddr, ethaddr);
AdamGreen	0:616601bde9fb	780	ETHADDR16_COPY(&ethhdr->src, ethaddr);
AdamGreen	0:616601bde9fb	781
AdamGreen	0:616601bde9fb	782	/* hwtype, hwaddr_len, proto, protolen and the type in the ethernet header
AdamGreen	0:616601bde9fb	783	are already correct, we tested that before */
AdamGreen	0:616601bde9fb	784
AdamGreen	0:616601bde9fb	785	/* return ARP reply */
AdamGreen	0:616601bde9fb	786	netif->linkoutput(netif, p);
AdamGreen	0:616601bde9fb	787	/* we are not configured? */
AdamGreen	0:616601bde9fb	788	} else if (ip_addr_isany(&netif->ip_addr)) {
AdamGreen	0:616601bde9fb	789	/* { for_us == 0 and netif->ip_addr.addr == 0 } */
AdamGreen	0:616601bde9fb	790	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_arp_input: we are unconfigured, ARP request ignored.\n"));
AdamGreen	0:616601bde9fb	791	/* request was not directed to us */
AdamGreen	0:616601bde9fb	792	} else {
AdamGreen	0:616601bde9fb	793	/* { for_us == 0 and netif->ip_addr.addr != 0 } */
AdamGreen	0:616601bde9fb	794	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_arp_input: ARP request was not for us.\n"));
AdamGreen	0:616601bde9fb	795	}
AdamGreen	0:616601bde9fb	796	break;
AdamGreen	0:616601bde9fb	797	case PP_HTONS(ARP_REPLY):
AdamGreen	0:616601bde9fb	798	/* ARP reply. We already updated the ARP cache earlier. */
AdamGreen	0:616601bde9fb	799	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_arp_input: incoming ARP reply\n"));
AdamGreen	0:616601bde9fb	800	#if (LWIP_DHCP && DHCP_DOES_ARP_CHECK)
AdamGreen	0:616601bde9fb	801	/* DHCP wants to know about ARP replies from any host with an
AdamGreen	0:616601bde9fb	802	* IP address also offered to us by the DHCP server. We do not
AdamGreen	0:616601bde9fb	803	* want to take a duplicate IP address on a single network.
AdamGreen	0:616601bde9fb	804	* @todo How should we handle redundant (fail-over) interfaces? */
AdamGreen	0:616601bde9fb	805	dhcp_arp_reply(netif, &sipaddr);
AdamGreen	0:616601bde9fb	806	#endif /* (LWIP_DHCP && DHCP_DOES_ARP_CHECK) */
AdamGreen	0:616601bde9fb	807	break;
AdamGreen	0:616601bde9fb	808	default:
AdamGreen	0:616601bde9fb	809	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_arp_input: ARP unknown opcode type %"S16_F"\n", htons(hdr->opcode)));
AdamGreen	0:616601bde9fb	810	ETHARP_STATS_INC(etharp.err);
AdamGreen	0:616601bde9fb	811	break;
AdamGreen	0:616601bde9fb	812	}
AdamGreen	0:616601bde9fb	813	/* free ARP packet */
AdamGreen	0:616601bde9fb	814	pbuf_free(p);
AdamGreen	0:616601bde9fb	815	}
AdamGreen	0:616601bde9fb	816
AdamGreen	0:616601bde9fb	817	/**
AdamGreen	0:616601bde9fb	818	* Resolve and fill-in Ethernet address header for outgoing IP packet.
AdamGreen	0:616601bde9fb	819	*
AdamGreen	0:616601bde9fb	820	* For IP multicast and broadcast, corresponding Ethernet addresses
AdamGreen	0:616601bde9fb	821	* are selected and the packet is transmitted on the link.
AdamGreen	0:616601bde9fb	822	*
AdamGreen	0:616601bde9fb	823	* For unicast addresses, the packet is submitted to etharp_query(). In
AdamGreen	0:616601bde9fb	824	* case the IP address is outside the local network, the IP address of
AdamGreen	0:616601bde9fb	825	* the gateway is used.
AdamGreen	0:616601bde9fb	826	*
AdamGreen	0:616601bde9fb	827	* @param netif The lwIP network interface which the IP packet will be sent on.
AdamGreen	0:616601bde9fb	828	* @param q The pbuf(s) containing the IP packet to be sent.
AdamGreen	0:616601bde9fb	829	* @param ipaddr The IP address of the packet destination.
AdamGreen	0:616601bde9fb	830	*
AdamGreen	0:616601bde9fb	831	* @return
AdamGreen	0:616601bde9fb	832	* - ERR_RTE No route to destination (no gateway to external networks),
AdamGreen	0:616601bde9fb	833	* or the return type of either etharp_query() or etharp_send_ip().
AdamGreen	0:616601bde9fb	834	*/
AdamGreen	0:616601bde9fb	835	err_t
AdamGreen	0:616601bde9fb	836	etharp_output(struct netif netif, struct pbuf q, ip_addr_t *ipaddr)
AdamGreen	0:616601bde9fb	837	{
AdamGreen	0:616601bde9fb	838	struct eth_addr *dest, mcastaddr;
AdamGreen	0:616601bde9fb	839
AdamGreen	0:616601bde9fb	840	/* make room for Ethernet header - should not fail */
AdamGreen	0:616601bde9fb	841	if (pbuf_header(q, sizeof(struct eth_hdr)) != 0) {
AdamGreen	0:616601bde9fb	842	/* bail out */
AdamGreen	0:616601bde9fb	843	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE \| LWIP_DBG_LEVEL_SERIOUS,
AdamGreen	0:616601bde9fb	844	("etharp_output: could not allocate room for header.\n"));
AdamGreen	0:616601bde9fb	845	LINK_STATS_INC(link.lenerr);
AdamGreen	0:616601bde9fb	846	return ERR_BUF;
AdamGreen	0:616601bde9fb	847	}
AdamGreen	0:616601bde9fb	848
AdamGreen	0:616601bde9fb	849	/* assume unresolved Ethernet address */
AdamGreen	0:616601bde9fb	850	dest = NULL;
AdamGreen	0:616601bde9fb	851	/* Determine on destination hardware address. Broadcasts and multicasts
AdamGreen	0:616601bde9fb	852	* are special, other IP addresses are looked up in the ARP table. */
AdamGreen	0:616601bde9fb	853
AdamGreen	0:616601bde9fb	854	/* broadcast destination IP address? */
AdamGreen	0:616601bde9fb	855	if (ip_addr_isbroadcast(ipaddr, netif)) {
AdamGreen	0:616601bde9fb	856	/* broadcast on Ethernet also */
AdamGreen	0:616601bde9fb	857	dest = (struct eth_addr *)&ethbroadcast;
AdamGreen	0:616601bde9fb	858	/* multicast destination IP address? */
AdamGreen	0:616601bde9fb	859	} else if (ip_addr_ismulticast(ipaddr)) {
AdamGreen	0:616601bde9fb	860	/* Hash IP multicast address to MAC address.*/
AdamGreen	0:616601bde9fb	861	mcastaddr.addr[0] = 0x01;
AdamGreen	0:616601bde9fb	862	mcastaddr.addr[1] = 0x00;
AdamGreen	0:616601bde9fb	863	mcastaddr.addr[2] = 0x5e;
AdamGreen	0:616601bde9fb	864	mcastaddr.addr[3] = ip4_addr2(ipaddr) & 0x7f;
AdamGreen	0:616601bde9fb	865	mcastaddr.addr[4] = ip4_addr3(ipaddr);
AdamGreen	0:616601bde9fb	866	mcastaddr.addr[5] = ip4_addr4(ipaddr);
AdamGreen	0:616601bde9fb	867	/* destination Ethernet address is multicast */
AdamGreen	0:616601bde9fb	868	dest = &mcastaddr;
AdamGreen	0:616601bde9fb	869	/* unicast destination IP address? */
AdamGreen	0:616601bde9fb	870	} else {
AdamGreen	0:616601bde9fb	871	/* outside local network? */
AdamGreen	0:616601bde9fb	872	if (!ip_addr_netcmp(ipaddr, &(netif->ip_addr), &(netif->netmask)) &&
AdamGreen	0:616601bde9fb	873	!ip_addr_islinklocal(ipaddr)) {
AdamGreen	0:616601bde9fb	874	/* interface has default gateway? */
AdamGreen	0:616601bde9fb	875	if (!ip_addr_isany(&netif->gw)) {
AdamGreen	0:616601bde9fb	876	/* send to hardware address of default gateway IP address */
AdamGreen	0:616601bde9fb	877	ipaddr = &(netif->gw);
AdamGreen	0:616601bde9fb	878	/* no default gateway available */
AdamGreen	0:616601bde9fb	879	} else {
AdamGreen	0:616601bde9fb	880	/* no route to destination error (default gateway missing) */
AdamGreen	0:616601bde9fb	881	return ERR_RTE;
AdamGreen	0:616601bde9fb	882	}
AdamGreen	0:616601bde9fb	883	}
AdamGreen	0:616601bde9fb	884	#if LWIP_NETIF_HWADDRHINT
AdamGreen	0:616601bde9fb	885	if (netif->addr_hint != NULL) {
AdamGreen	0:616601bde9fb	886	/* per-pcb cached entry was given */
AdamGreen	0:616601bde9fb	887	u8_t etharp_cached_entry = *(netif->addr_hint);
AdamGreen	0:616601bde9fb	888	if (etharp_cached_entry < ARP_TABLE_SIZE) {
AdamGreen	0:616601bde9fb	889	#endif /* LWIP_NETIF_HWADDRHINT */
AdamGreen	0:616601bde9fb	890	if ((arp_table[etharp_cached_entry].state == ETHARP_STATE_STABLE) &&
AdamGreen	0:616601bde9fb	891	(ip_addr_cmp(ipaddr, &arp_table[etharp_cached_entry].ipaddr))) {
AdamGreen	0:616601bde9fb	892	/* the per-pcb-cached entry is stable and the right one! */
AdamGreen	0:616601bde9fb	893	ETHARP_STATS_INC(etharp.cachehit);
AdamGreen	0:616601bde9fb	894	return etharp_send_ip(netif, q, (struct eth_addr*)(netif->hwaddr),
AdamGreen	0:616601bde9fb	895	&arp_table[etharp_cached_entry].ethaddr);
AdamGreen	0:616601bde9fb	896	}
AdamGreen	0:616601bde9fb	897	#if LWIP_NETIF_HWADDRHINT
AdamGreen	0:616601bde9fb	898	}
AdamGreen	0:616601bde9fb	899	}
AdamGreen	0:616601bde9fb	900	#endif /* LWIP_NETIF_HWADDRHINT */
AdamGreen	0:616601bde9fb	901	/* queue on destination Ethernet address belonging to ipaddr */
AdamGreen	0:616601bde9fb	902	return etharp_query(netif, ipaddr, q);
AdamGreen	0:616601bde9fb	903	}
AdamGreen	0:616601bde9fb	904
AdamGreen	0:616601bde9fb	905	/* continuation for multicast/broadcast destinations */
AdamGreen	0:616601bde9fb	906	/* obtain source Ethernet address of the given interface */
AdamGreen	0:616601bde9fb	907	/* send packet directly on the link */
AdamGreen	0:616601bde9fb	908	return etharp_send_ip(netif, q, (struct eth_addr*)(netif->hwaddr), dest);
AdamGreen	0:616601bde9fb	909	}
AdamGreen	0:616601bde9fb	910
AdamGreen	0:616601bde9fb	911	/**
AdamGreen	0:616601bde9fb	912	* Send an ARP request for the given IP address and/or queue a packet.
AdamGreen	0:616601bde9fb	913	*
AdamGreen	0:616601bde9fb	914	* If the IP address was not yet in the cache, a pending ARP cache entry
AdamGreen	0:616601bde9fb	915	* is added and an ARP request is sent for the given address. The packet
AdamGreen	0:616601bde9fb	916	* is queued on this entry.
AdamGreen	0:616601bde9fb	917	*
AdamGreen	0:616601bde9fb	918	* If the IP address was already pending in the cache, a new ARP request
AdamGreen	0:616601bde9fb	919	* is sent for the given address. The packet is queued on this entry.
AdamGreen	0:616601bde9fb	920	*
AdamGreen	0:616601bde9fb	921	* If the IP address was already stable in the cache, and a packet is
AdamGreen	0:616601bde9fb	922	* given, it is directly sent and no ARP request is sent out.
AdamGreen	0:616601bde9fb	923	*
AdamGreen	0:616601bde9fb	924	* If the IP address was already stable in the cache, and no packet is
AdamGreen	0:616601bde9fb	925	* given, an ARP request is sent out.
AdamGreen	0:616601bde9fb	926	*
AdamGreen	0:616601bde9fb	927	* @param netif The lwIP network interface on which ipaddr
AdamGreen	0:616601bde9fb	928	* must be queried for.
AdamGreen	0:616601bde9fb	929	* @param ipaddr The IP address to be resolved.
AdamGreen	0:616601bde9fb	930	* @param q If non-NULL, a pbuf that must be delivered to the IP address.
AdamGreen	0:616601bde9fb	931	* q is not freed by this function.
AdamGreen	0:616601bde9fb	932	*
AdamGreen	0:616601bde9fb	933	* @note q must only be ONE packet, not a packet queue!
AdamGreen	0:616601bde9fb	934	*
AdamGreen	0:616601bde9fb	935	* @return
AdamGreen	0:616601bde9fb	936	* - ERR_BUF Could not make room for Ethernet header.
AdamGreen	0:616601bde9fb	937	* - ERR_MEM Hardware address unknown, and no more ARP entries available
AdamGreen	0:616601bde9fb	938	* to query for address or queue the packet.
AdamGreen	0:616601bde9fb	939	* - ERR_MEM Could not queue packet due to memory shortage.
AdamGreen	0:616601bde9fb	940	* - ERR_RTE No route to destination (no gateway to external networks).
AdamGreen	0:616601bde9fb	941	* - ERR_ARG Non-unicast address given, those will not appear in ARP cache.
AdamGreen	0:616601bde9fb	942	*
AdamGreen	0:616601bde9fb	943	*/
AdamGreen	0:616601bde9fb	944	err_t
AdamGreen	0:616601bde9fb	945	etharp_query(struct netif netif, ip_addr_t ipaddr, struct pbuf *q)
AdamGreen	0:616601bde9fb	946	{
AdamGreen	0:616601bde9fb	947	struct eth_addr * srcaddr = (struct eth_addr *)netif->hwaddr;
AdamGreen	0:616601bde9fb	948	err_t result = ERR_MEM;
AdamGreen	0:616601bde9fb	949	s8_t i; /* ARP entry index */
AdamGreen	0:616601bde9fb	950
AdamGreen	0:616601bde9fb	951	/* non-unicast address? */
AdamGreen	0:616601bde9fb	952	if (ip_addr_isbroadcast(ipaddr, netif) \|\|
AdamGreen	0:616601bde9fb	953	ip_addr_ismulticast(ipaddr) \|\|
AdamGreen	0:616601bde9fb	954	ip_addr_isany(ipaddr)) {
AdamGreen	0:616601bde9fb	955	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_query: will not add non-unicast IP address to ARP cache\n"));
AdamGreen	0:616601bde9fb	956	return ERR_ARG;
AdamGreen	0:616601bde9fb	957	}
AdamGreen	0:616601bde9fb	958
AdamGreen	0:616601bde9fb	959	/* find entry in ARP cache, ask to create entry if queueing packet */
AdamGreen	0:616601bde9fb	960	i = find_entry(ipaddr, ETHARP_FLAG_TRY_HARD);
AdamGreen	0:616601bde9fb	961
AdamGreen	0:616601bde9fb	962	/* could not find or create entry? */
AdamGreen	0:616601bde9fb	963	if (i < 0) {
AdamGreen	0:616601bde9fb	964	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_query: could not create ARP entry\n"));
AdamGreen	0:616601bde9fb	965	if (q) {
AdamGreen	0:616601bde9fb	966	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_query: packet dropped\n"));
AdamGreen	0:616601bde9fb	967	ETHARP_STATS_INC(etharp.memerr);
AdamGreen	0:616601bde9fb	968	}
AdamGreen	0:616601bde9fb	969	return (err_t)i;
AdamGreen	0:616601bde9fb	970	}
AdamGreen	0:616601bde9fb	971
AdamGreen	0:616601bde9fb	972	/* mark a fresh entry as pending (we just sent a request) */
AdamGreen	0:616601bde9fb	973	if (arp_table[i].state == ETHARP_STATE_EMPTY) {
AdamGreen	0:616601bde9fb	974	arp_table[i].state = ETHARP_STATE_PENDING;
AdamGreen	0:616601bde9fb	975	}
AdamGreen	0:616601bde9fb	976
AdamGreen	0:616601bde9fb	977	/* { i is either a STABLE or (new or existing) PENDING entry } */
AdamGreen	0:616601bde9fb	978	LWIP_ASSERT("arp_table[i].state == PENDING or STABLE",
AdamGreen	0:616601bde9fb	979	((arp_table[i].state == ETHARP_STATE_PENDING) \|\|
AdamGreen	0:616601bde9fb	980	(arp_table[i].state == ETHARP_STATE_STABLE)));
AdamGreen	0:616601bde9fb	981
AdamGreen	0:616601bde9fb	982	/* do we have a pending entry? or an implicit query request? */
AdamGreen	0:616601bde9fb	983	if ((arp_table[i].state == ETHARP_STATE_PENDING) \|\| (q == NULL)) {
AdamGreen	0:616601bde9fb	984	/* try to resolve it; send out ARP request */
AdamGreen	0:616601bde9fb	985	result = etharp_request(netif, ipaddr);
AdamGreen	0:616601bde9fb	986	if (result != ERR_OK) {
AdamGreen	0:616601bde9fb	987	/* ARP request couldn't be sent */
AdamGreen	0:616601bde9fb	988	/* We don't re-send arp request in etharp_tmr, but we still queue packets,
AdamGreen	0:616601bde9fb	989	since this failure could be temporary, and the next packet calling
AdamGreen	0:616601bde9fb	990	etharp_query again could lead to sending the queued packets. */
AdamGreen	0:616601bde9fb	991	}
AdamGreen	0:616601bde9fb	992	if (q == NULL) {
AdamGreen	0:616601bde9fb	993	return result;
AdamGreen	0:616601bde9fb	994	}
AdamGreen	0:616601bde9fb	995	}
AdamGreen	0:616601bde9fb	996
AdamGreen	0:616601bde9fb	997	/* packet given? */
AdamGreen	0:616601bde9fb	998	LWIP_ASSERT("q != NULL", q != NULL);
AdamGreen	0:616601bde9fb	999	/* stable entry? */
AdamGreen	0:616601bde9fb	1000	if (arp_table[i].state == ETHARP_STATE_STABLE) {
AdamGreen	0:616601bde9fb	1001	/* we have a valid IP->Ethernet address mapping */
AdamGreen	0:616601bde9fb	1002	ETHARP_SET_HINT(netif, i);
AdamGreen	0:616601bde9fb	1003	/* send the packet */
AdamGreen	0:616601bde9fb	1004	result = etharp_send_ip(netif, q, srcaddr, &(arp_table[i].ethaddr));
AdamGreen	0:616601bde9fb	1005	/* pending entry? (either just created or already pending */
AdamGreen	0:616601bde9fb	1006	} else if (arp_table[i].state == ETHARP_STATE_PENDING) {
AdamGreen	0:616601bde9fb	1007	#if ARP_QUEUEING /* queue the given q packet */
AdamGreen	0:616601bde9fb	1008	struct pbuf *p;
AdamGreen	0:616601bde9fb	1009	int copy_needed = 0;
AdamGreen	0:616601bde9fb	1010	/* IF q includes a PBUF_REF, PBUF_POOL or PBUF_RAM, we have no choice but
AdamGreen	0:616601bde9fb	1011	* to copy the whole queue into a new PBUF_RAM (see bug #11400)
AdamGreen	0:616601bde9fb	1012	* PBUF_ROMs can be left as they are, since ROM must not get changed. */
AdamGreen	0:616601bde9fb	1013	p = q;
AdamGreen	0:616601bde9fb	1014	while (p) {
AdamGreen	0:616601bde9fb	1015	LWIP_ASSERT("no packet queues allowed!", (p->len != p->tot_len) \|\| (p->next == 0));
AdamGreen	0:616601bde9fb	1016	if(p->type != PBUF_ROM) {
AdamGreen	0:616601bde9fb	1017	copy_needed = 1;
AdamGreen	0:616601bde9fb	1018	break;
AdamGreen	0:616601bde9fb	1019	}
AdamGreen	0:616601bde9fb	1020	p = p->next;
AdamGreen	0:616601bde9fb	1021	}
AdamGreen	0:616601bde9fb	1022	if(copy_needed) {
AdamGreen	0:616601bde9fb	1023	/* copy the whole packet into new pbufs */
AdamGreen	0:616601bde9fb	1024	p = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
AdamGreen	0:616601bde9fb	1025	if(p != NULL) {
AdamGreen	0:616601bde9fb	1026	if (pbuf_copy(p, q) != ERR_OK) {
AdamGreen	0:616601bde9fb	1027	pbuf_free(p);
AdamGreen	0:616601bde9fb	1028	p = NULL;
AdamGreen	0:616601bde9fb	1029	}
AdamGreen	0:616601bde9fb	1030	}
AdamGreen	0:616601bde9fb	1031	} else {
AdamGreen	0:616601bde9fb	1032	/* referencing the old pbuf is enough */
AdamGreen	0:616601bde9fb	1033	p = q;
AdamGreen	0:616601bde9fb	1034	pbuf_ref(p);
AdamGreen	0:616601bde9fb	1035	}
AdamGreen	0:616601bde9fb	1036	/* packet could be taken over? */
AdamGreen	0:616601bde9fb	1037	if (p != NULL) {
AdamGreen	0:616601bde9fb	1038	/* queue packet ... */
AdamGreen	0:616601bde9fb	1039	struct etharp_q_entry *new_entry;
AdamGreen	0:616601bde9fb	1040	/* allocate a new arp queue entry */
AdamGreen	0:616601bde9fb	1041	new_entry = (struct etharp_q_entry *)memp_malloc(MEMP_ARP_QUEUE);
AdamGreen	0:616601bde9fb	1042	if (new_entry != NULL) {
AdamGreen	0:616601bde9fb	1043	new_entry->next = 0;
AdamGreen	0:616601bde9fb	1044	new_entry->p = p;
AdamGreen	0:616601bde9fb	1045	if(arp_table[i].q != NULL) {
AdamGreen	0:616601bde9fb	1046	/* queue was already existent, append the new entry to the end */
AdamGreen	0:616601bde9fb	1047	struct etharp_q_entry *r;
AdamGreen	0:616601bde9fb	1048	r = arp_table[i].q;
AdamGreen	0:616601bde9fb	1049	while (r->next != NULL) {
AdamGreen	0:616601bde9fb	1050	r = r->next;
AdamGreen	0:616601bde9fb	1051	}
AdamGreen	0:616601bde9fb	1052	r->next = new_entry;
AdamGreen	0:616601bde9fb	1053	} else {
AdamGreen	0:616601bde9fb	1054	/* queue did not exist, first item in queue */
AdamGreen	0:616601bde9fb	1055	arp_table[i].q = new_entry;
AdamGreen	0:616601bde9fb	1056	}
AdamGreen	0:616601bde9fb	1057	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_query: queued packet %p on ARP entry %"S16_F"\n", (void *)q, (s16_t)i));
AdamGreen	0:616601bde9fb	1058	result = ERR_OK;
AdamGreen	0:616601bde9fb	1059	} else {
AdamGreen	0:616601bde9fb	1060	/* the pool MEMP_ARP_QUEUE is empty */
AdamGreen	0:616601bde9fb	1061	pbuf_free(p);
AdamGreen	0:616601bde9fb	1062	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));
AdamGreen	0:616601bde9fb	1063	/* { result == ERR_MEM } through initialization */
AdamGreen	0:616601bde9fb	1064	}
AdamGreen	0:616601bde9fb	1065	} else {
AdamGreen	0:616601bde9fb	1066	ETHARP_STATS_INC(etharp.memerr);
AdamGreen	0:616601bde9fb	1067	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));
AdamGreen	0:616601bde9fb	1068	/* { result == ERR_MEM } through initialization */
AdamGreen	0:616601bde9fb	1069	}
AdamGreen	0:616601bde9fb	1070	#else /* ARP_QUEUEING */
AdamGreen	0:616601bde9fb	1071	/* q && state == PENDING && ARP_QUEUEING == 0 => result = ERR_MEM */
AdamGreen	0:616601bde9fb	1072	/* { result == ERR_MEM } through initialization */
AdamGreen	0:616601bde9fb	1073	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_query: Ethernet destination address unknown, queueing disabled, packet %p dropped\n", (void *)q));
AdamGreen	0:616601bde9fb	1074	#endif /* ARP_QUEUEING */
AdamGreen	0:616601bde9fb	1075	}
AdamGreen	0:616601bde9fb	1076	return result;
AdamGreen	0:616601bde9fb	1077	}
AdamGreen	0:616601bde9fb	1078
AdamGreen	0:616601bde9fb	1079	/**
AdamGreen	0:616601bde9fb	1080	* Send a raw ARP packet (opcode and all addresses can be modified)
AdamGreen	0:616601bde9fb	1081	*
AdamGreen	0:616601bde9fb	1082	* @param netif the lwip network interface on which to send the ARP packet
AdamGreen	0:616601bde9fb	1083	* @param ethsrc_addr the source MAC address for the ethernet header
AdamGreen	0:616601bde9fb	1084	* @param ethdst_addr the destination MAC address for the ethernet header
AdamGreen	0:616601bde9fb	1085	* @param hwsrc_addr the source MAC address for the ARP protocol header
AdamGreen	0:616601bde9fb	1086	* @param ipsrc_addr the source IP address for the ARP protocol header
AdamGreen	0:616601bde9fb	1087	* @param hwdst_addr the destination MAC address for the ARP protocol header
AdamGreen	0:616601bde9fb	1088	* @param ipdst_addr the destination IP address for the ARP protocol header
AdamGreen	0:616601bde9fb	1089	* @param opcode the type of the ARP packet
AdamGreen	0:616601bde9fb	1090	* @return ERR_OK if the ARP packet has been sent
AdamGreen	0:616601bde9fb	1091	* ERR_MEM if the ARP packet couldn't be allocated
AdamGreen	0:616601bde9fb	1092	* any other err_t on failure
AdamGreen	0:616601bde9fb	1093	*/
AdamGreen	0:616601bde9fb	1094	#if !LWIP_AUTOIP
AdamGreen	0:616601bde9fb	1095	static
AdamGreen	0:616601bde9fb	1096	#endif /* LWIP_AUTOIP */
AdamGreen	0:616601bde9fb	1097	err_t
AdamGreen	0:616601bde9fb	1098	etharp_raw(struct netif netif, const struct eth_addr ethsrc_addr,
AdamGreen	0:616601bde9fb	1099	const struct eth_addr *ethdst_addr,
AdamGreen	0:616601bde9fb	1100	const struct eth_addr hwsrc_addr, const ip_addr_t ipsrc_addr,
AdamGreen	0:616601bde9fb	1101	const struct eth_addr hwdst_addr, const ip_addr_t ipdst_addr,
AdamGreen	0:616601bde9fb	1102	const u16_t opcode)
AdamGreen	0:616601bde9fb	1103	{
AdamGreen	0:616601bde9fb	1104	struct pbuf *p;
AdamGreen	0:616601bde9fb	1105	err_t result = ERR_OK;
AdamGreen	0:616601bde9fb	1106	struct eth_hdr *ethhdr;
AdamGreen	0:616601bde9fb	1107	struct etharp_hdr *hdr;
AdamGreen	0:616601bde9fb	1108	#if LWIP_AUTOIP
AdamGreen	0:616601bde9fb	1109	const u8_t * ethdst_hwaddr;
AdamGreen	0:616601bde9fb	1110	#endif /* LWIP_AUTOIP */
AdamGreen	0:616601bde9fb	1111
AdamGreen	0:616601bde9fb	1112	/* allocate a pbuf for the outgoing ARP request packet */
AdamGreen	0:616601bde9fb	1113	p = pbuf_alloc(PBUF_RAW, SIZEOF_ETHARP_PACKET, PBUF_RAM);
AdamGreen	0:616601bde9fb	1114	/* could allocate a pbuf for an ARP request? */
AdamGreen	0:616601bde9fb	1115	if (p == NULL) {
AdamGreen	0:616601bde9fb	1116	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE \| LWIP_DBG_LEVEL_SERIOUS,
AdamGreen	0:616601bde9fb	1117	("etharp_raw: could not allocate pbuf for ARP request.\n"));
AdamGreen	0:616601bde9fb	1118	ETHARP_STATS_INC(etharp.memerr);
AdamGreen	0:616601bde9fb	1119	return ERR_MEM;
AdamGreen	0:616601bde9fb	1120	}
AdamGreen	0:616601bde9fb	1121	LWIP_ASSERT("check that first pbuf can hold struct etharp_hdr",
AdamGreen	0:616601bde9fb	1122	(p->len >= SIZEOF_ETHARP_PACKET));
AdamGreen	0:616601bde9fb	1123
AdamGreen	0:616601bde9fb	1124	ethhdr = (struct eth_hdr *)p->payload;
AdamGreen	0:616601bde9fb	1125	hdr = (struct etharp_hdr )((u8_t)ethhdr + SIZEOF_ETH_HDR);
AdamGreen	0:616601bde9fb	1126	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_raw: sending raw ARP packet.\n"));
AdamGreen	0:616601bde9fb	1127	hdr->opcode = htons(opcode);
AdamGreen	0:616601bde9fb	1128
AdamGreen	0:616601bde9fb	1129	LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!",
AdamGreen	0:616601bde9fb	1130	(netif->hwaddr_len == ETHARP_HWADDR_LEN));
AdamGreen	0:616601bde9fb	1131	#if LWIP_AUTOIP
AdamGreen	0:616601bde9fb	1132	/* If we are using Link-Local, all ARP packets that contain a Link-Local
AdamGreen	0:616601bde9fb	1133	* 'sender IP address' MUST be sent using link-layer broadcast instead of
AdamGreen	0:616601bde9fb	1134	* link-layer unicast. (See RFC3927 Section 2.5, last paragraph) */
AdamGreen	0:616601bde9fb	1135	ethdst_hwaddr = ip_addr_islinklocal(ipsrc_addr) ? (u8_t*)(ethbroadcast.addr) : ethdst_addr->addr;
AdamGreen	0:616601bde9fb	1136	#endif /* LWIP_AUTOIP */
AdamGreen	0:616601bde9fb	1137	/* Write the ARP MAC-Addresses */
AdamGreen	0:616601bde9fb	1138	ETHADDR16_COPY(&hdr->shwaddr, hwsrc_addr);
AdamGreen	0:616601bde9fb	1139	ETHADDR16_COPY(&hdr->dhwaddr, hwdst_addr);
AdamGreen	0:616601bde9fb	1140	/* Write the Ethernet MAC-Addresses */
AdamGreen	0:616601bde9fb	1141	#if LWIP_AUTOIP
AdamGreen	0:616601bde9fb	1142	ETHADDR16_COPY(&ethhdr->dest, ethdst_hwaddr);
AdamGreen	0:616601bde9fb	1143	#else /* LWIP_AUTOIP */
AdamGreen	0:616601bde9fb	1144	ETHADDR16_COPY(&ethhdr->dest, ethdst_addr);
AdamGreen	0:616601bde9fb	1145	#endif /* LWIP_AUTOIP */
AdamGreen	0:616601bde9fb	1146	ETHADDR16_COPY(&ethhdr->src, ethsrc_addr);
AdamGreen	0:616601bde9fb	1147	/* Copy struct ip_addr2 to aligned ip_addr, to support compilers without
AdamGreen	0:616601bde9fb	1148	* structure packing. */
AdamGreen	0:616601bde9fb	1149	IPADDR2_COPY(&hdr->sipaddr, ipsrc_addr);
AdamGreen	0:616601bde9fb	1150	IPADDR2_COPY(&hdr->dipaddr, ipdst_addr);
AdamGreen	0:616601bde9fb	1151
AdamGreen	0:616601bde9fb	1152	hdr->hwtype = PP_HTONS(HWTYPE_ETHERNET);
AdamGreen	0:616601bde9fb	1153	hdr->proto = PP_HTONS(ETHTYPE_IP);
AdamGreen	0:616601bde9fb	1154	/* set hwlen and protolen */
AdamGreen	0:616601bde9fb	1155	hdr->hwlen = ETHARP_HWADDR_LEN;
AdamGreen	0:616601bde9fb	1156	hdr->protolen = sizeof(ip_addr_t);
AdamGreen	0:616601bde9fb	1157
AdamGreen	0:616601bde9fb	1158	ethhdr->type = PP_HTONS(ETHTYPE_ARP);
AdamGreen	0:616601bde9fb	1159	/* send ARP query */
AdamGreen	0:616601bde9fb	1160	result = netif->linkoutput(netif, p);
AdamGreen	0:616601bde9fb	1161	ETHARP_STATS_INC(etharp.xmit);
AdamGreen	0:616601bde9fb	1162	/* free ARP query packet */
AdamGreen	0:616601bde9fb	1163	pbuf_free(p);
AdamGreen	0:616601bde9fb	1164	p = NULL;
AdamGreen	0:616601bde9fb	1165	/* could not allocate pbuf for ARP request */
AdamGreen	0:616601bde9fb	1166
AdamGreen	0:616601bde9fb	1167	return result;
AdamGreen	0:616601bde9fb	1168	}
AdamGreen	0:616601bde9fb	1169
AdamGreen	0:616601bde9fb	1170	/**
AdamGreen	0:616601bde9fb	1171	* Send an ARP request packet asking for ipaddr.
AdamGreen	0:616601bde9fb	1172	*
AdamGreen	0:616601bde9fb	1173	* @param netif the lwip network interface on which to send the request
AdamGreen	0:616601bde9fb	1174	* @param ipaddr the IP address for which to ask
AdamGreen	0:616601bde9fb	1175	* @return ERR_OK if the request has been sent
AdamGreen	0:616601bde9fb	1176	* ERR_MEM if the ARP packet couldn't be allocated
AdamGreen	0:616601bde9fb	1177	* any other err_t on failure
AdamGreen	0:616601bde9fb	1178	*/
AdamGreen	0:616601bde9fb	1179	err_t
AdamGreen	0:616601bde9fb	1180	etharp_request(struct netif netif, ip_addr_t ipaddr)
AdamGreen	0:616601bde9fb	1181	{
AdamGreen	0:616601bde9fb	1182	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE, ("etharp_request: sending ARP request.\n"));
AdamGreen	0:616601bde9fb	1183	return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, &ethbroadcast,
AdamGreen	0:616601bde9fb	1184	(struct eth_addr *)netif->hwaddr, &netif->ip_addr, &ethzero,
AdamGreen	0:616601bde9fb	1185	ipaddr, ARP_REQUEST);
AdamGreen	0:616601bde9fb	1186	}
AdamGreen	0:616601bde9fb	1187	#endif /* LWIP_ARP */
AdamGreen	0:616601bde9fb	1188
AdamGreen	0:616601bde9fb	1189	/**
AdamGreen	0:616601bde9fb	1190	* Process received ethernet frames. Using this function instead of directly
AdamGreen	0:616601bde9fb	1191	* calling ip_input and passing ARP frames through etharp in ethernetif_input,
AdamGreen	0:616601bde9fb	1192	* the ARP cache is protected from concurrent access.
AdamGreen	0:616601bde9fb	1193	*
AdamGreen	0:616601bde9fb	1194	* @param p the recevied packet, p->payload pointing to the ethernet header
AdamGreen	0:616601bde9fb	1195	* @param netif the network interface on which the packet was received
AdamGreen	0:616601bde9fb	1196	*/
AdamGreen	0:616601bde9fb	1197	err_t
AdamGreen	0:616601bde9fb	1198	ethernet_input(struct pbuf p, struct netif netif)
AdamGreen	0:616601bde9fb	1199	{
AdamGreen	0:616601bde9fb	1200	struct eth_hdr* ethhdr;
AdamGreen	0:616601bde9fb	1201	u16_t type;
AdamGreen	0:616601bde9fb	1202
AdamGreen	0:616601bde9fb	1203	/* points to packet payload, which starts with an Ethernet header */
AdamGreen	0:616601bde9fb	1204	ethhdr = (struct eth_hdr *)p->payload;
AdamGreen	0:616601bde9fb	1205	LWIP_DEBUGF(ETHARP_DEBUG \| LWIP_DBG_TRACE,
AdamGreen	0:616601bde9fb	1206	("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",
AdamGreen	0:616601bde9fb	1207	(unsigned)ethhdr->dest.addr[0], (unsigned)ethhdr->dest.addr[1], (unsigned)ethhdr->dest.addr[2],
AdamGreen	0:616601bde9fb	1208	(unsigned)ethhdr->dest.addr[3], (unsigned)ethhdr->dest.addr[4], (unsigned)ethhdr->dest.addr[5],
AdamGreen	0:616601bde9fb	1209	(unsigned)ethhdr->src.addr[0], (unsigned)ethhdr->src.addr[1], (unsigned)ethhdr->src.addr[2],
AdamGreen	0:616601bde9fb	1210	(unsigned)ethhdr->src.addr[3], (unsigned)ethhdr->src.addr[4], (unsigned)ethhdr->src.addr[5],
AdamGreen	0:616601bde9fb	1211	(unsigned)htons(ethhdr->type)));
AdamGreen	0:616601bde9fb	1212
AdamGreen	0:616601bde9fb	1213	type = ethhdr->type;
AdamGreen	0:616601bde9fb	1214	#if ETHARP_SUPPORT_VLAN
AdamGreen	0:616601bde9fb	1215	if (type == PP_HTONS(ETHTYPE_VLAN)) {
AdamGreen	0:616601bde9fb	1216	struct eth_vlan_hdr vlan = (struct eth_vlan_hdr)(((char*)ethhdr) + SIZEOF_ETH_HDR);
AdamGreen	0:616601bde9fb	1217	#ifdef ETHARP_VLAN_CHECK /* if not, allow all VLANs */
AdamGreen	0:616601bde9fb	1218	if (VLAN_ID(vlan) != ETHARP_VLAN_CHECK) {
AdamGreen	0:616601bde9fb	1219	/* silently ignore this packet: not for our VLAN */
AdamGreen	0:616601bde9fb	1220	pbuf_free(p);
AdamGreen	0:616601bde9fb	1221	return ERR_OK;
AdamGreen	0:616601bde9fb	1222	}
AdamGreen	0:616601bde9fb	1223	#endif /* ETHARP_VLAN_CHECK */
AdamGreen	0:616601bde9fb	1224	type = vlan->tpid;
AdamGreen	0:616601bde9fb	1225	}
AdamGreen	0:616601bde9fb	1226	#endif /* ETHARP_SUPPORT_VLAN */
AdamGreen	0:616601bde9fb	1227
AdamGreen	0:616601bde9fb	1228	#if LWIP_ARP_FILTER_NETIF
AdamGreen	0:616601bde9fb	1229	netif = LWIP_ARP_FILTER_NETIF_FN(p, netif, htons(type));
AdamGreen	0:616601bde9fb	1230	#endif /* LWIP_ARP_FILTER_NETIF*/
AdamGreen	0:616601bde9fb	1231
AdamGreen	0:616601bde9fb	1232	switch (type) {
AdamGreen	0:616601bde9fb	1233	#if LWIP_ARP
AdamGreen	0:616601bde9fb	1234	/* IP packet? */
AdamGreen	0:616601bde9fb	1235	case PP_HTONS(ETHTYPE_IP):
AdamGreen	0:616601bde9fb	1236	if (!(netif->flags & NETIF_FLAG_ETHARP)) {
AdamGreen	0:616601bde9fb	1237	goto free_and_return;
AdamGreen	0:616601bde9fb	1238	}
AdamGreen	0:616601bde9fb	1239	#if ETHARP_TRUST_IP_MAC
AdamGreen	0:616601bde9fb	1240	/* update ARP table */
AdamGreen	0:616601bde9fb	1241	etharp_ip_input(netif, p);
AdamGreen	0:616601bde9fb	1242	#endif /* ETHARP_TRUST_IP_MAC */
AdamGreen	0:616601bde9fb	1243	/* skip Ethernet header */
AdamGreen	0:616601bde9fb	1244	if(pbuf_header(p, -(s16_t)SIZEOF_ETH_HDR)) {
AdamGreen	0:616601bde9fb	1245	LWIP_ASSERT("Can't move over header in packet", 0);
AdamGreen	0:616601bde9fb	1246	goto free_and_return;
AdamGreen	0:616601bde9fb	1247	} else {
AdamGreen	0:616601bde9fb	1248	/* pass to IP layer */
AdamGreen	0:616601bde9fb	1249	ip_input(p, netif);
AdamGreen	0:616601bde9fb	1250	}
AdamGreen	0:616601bde9fb	1251	break;
AdamGreen	0:616601bde9fb	1252
AdamGreen	0:616601bde9fb	1253	case PP_HTONS(ETHTYPE_ARP):
AdamGreen	0:616601bde9fb	1254	if (!(netif->flags & NETIF_FLAG_ETHARP)) {
AdamGreen	0:616601bde9fb	1255	goto free_and_return;
AdamGreen	0:616601bde9fb	1256	}
AdamGreen	0:616601bde9fb	1257	/* pass p to ARP module */
AdamGreen	0:616601bde9fb	1258	etharp_arp_input(netif, (struct eth_addr*)(netif->hwaddr), p);
AdamGreen	0:616601bde9fb	1259	break;
AdamGreen	0:616601bde9fb	1260	#endif /* LWIP_ARP */
AdamGreen	0:616601bde9fb	1261	#if PPPOE_SUPPORT
AdamGreen	0:616601bde9fb	1262	case PP_HTONS(ETHTYPE_PPPOEDISC): /* PPP Over Ethernet Discovery Stage */
AdamGreen	0:616601bde9fb	1263	pppoe_disc_input(netif, p);
AdamGreen	0:616601bde9fb	1264	break;
AdamGreen	0:616601bde9fb	1265
AdamGreen	0:616601bde9fb	1266	case PP_HTONS(ETHTYPE_PPPOE): /* PPP Over Ethernet Session Stage */
AdamGreen	0:616601bde9fb	1267	pppoe_data_input(netif, p);
AdamGreen	0:616601bde9fb	1268	break;
AdamGreen	0:616601bde9fb	1269	#endif /* PPPOE_SUPPORT */
AdamGreen	0:616601bde9fb	1270
AdamGreen	0:616601bde9fb	1271	default:
AdamGreen	0:616601bde9fb	1272	ETHARP_STATS_INC(etharp.proterr);
AdamGreen	0:616601bde9fb	1273	ETHARP_STATS_INC(etharp.drop);
AdamGreen	0:616601bde9fb	1274	goto free_and_return;
AdamGreen	0:616601bde9fb	1275	}
AdamGreen	0:616601bde9fb	1276
AdamGreen	0:616601bde9fb	1277	/* This means the pbuf is freed or consumed,
AdamGreen	0:616601bde9fb	1278	so the caller doesn't have to free it again */
AdamGreen	0:616601bde9fb	1279	return ERR_OK;
AdamGreen	0:616601bde9fb	1280
AdamGreen	0:616601bde9fb	1281	free_and_return:
AdamGreen	0:616601bde9fb	1282	pbuf_free(p);
AdamGreen	0:616601bde9fb	1283	return ERR_OK;
AdamGreen	0:616601bde9fb	1284	}
AdamGreen	0:616601bde9fb	1285	#endif /* LWIP_ARP \|\| LWIP_ETHERNET */

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	23 Feb 2012
Imports:	113
Forks:	0
Commits:	2
Dependents:	0
Dependencies:	4
Followers:	6

NetStack/lwip/netif/etharp.c@0:616601bde9fb, 2012-02-23 (annotated)

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