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Posted to commits@mynewt.apache.org by ma...@apache.org on 2016/09/30 00:31:03 UTC
[20/51] [abbrv] [partial] incubator-mynewt-core git commit:
net/ip/lwip_base; LwIP.
http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/blob/f5a0f2a0/net/ip/lwip_base/src/core/ipv4/etharp.c
----------------------------------------------------------------------
diff --git a/net/ip/lwip_base/src/core/ipv4/etharp.c b/net/ip/lwip_base/src/core/ipv4/etharp.c
new file mode 100644
index 0000000..364023e
--- /dev/null
+++ b/net/ip/lwip_base/src/core/ipv4/etharp.c
@@ -0,0 +1,1219 @@
+/**
+ * @file
+ * Address Resolution Protocol module for IP over Ethernet
+ *
+ * Functionally, ARP is divided into two parts. The first maps an IP address
+ * to a physical address when sending a packet, and the second part answers
+ * requests from other machines for our physical address.
+ *
+ * This implementation complies with RFC 826 (Ethernet ARP). It supports
+ * Gratuitious ARP from RFC3220 (IP Mobility Support for IPv4) section 4.6
+ * if an interface calls etharp_gratuitous(our_netif) upon address change.
+ */
+
+/*
+ * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
+ * Copyright (c) 2003-2004 Leon Woestenberg <le...@axon.tv>
+ * Copyright (c) 2003-2004 Axon Digital Design B.V., The Netherlands.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_ARP || LWIP_ETHERNET
+
+#include "lwip/etharp.h"
+#include "lwip/stats.h"
+#include "lwip/snmp.h"
+#include "lwip/dhcp.h"
+#include "lwip/autoip.h"
+#include "netif/ethernet.h"
+
+#include <string.h>
+
+#if LWIP_IPV4 && LWIP_ARP /* don't build if not configured for use in lwipopts.h */
+
+/** Re-request a used ARP entry 1 minute before it would expire to prevent
+ * breaking a steadily used connection because the ARP entry timed out. */
+#define ARP_AGE_REREQUEST_USED_UNICAST (ARP_MAXAGE - 30)
+#define ARP_AGE_REREQUEST_USED_BROADCAST (ARP_MAXAGE - 15)
+
+/** the time an ARP entry stays pending after first request,
+ * for ARP_TMR_INTERVAL = 1000, this is
+ * 10 seconds.
+ *
+ * @internal Keep this number at least 2, otherwise it might
+ * run out instantly if the timeout occurs directly after a request.
+ */
+#define ARP_MAXPENDING 5
+
+enum etharp_state {
+ ETHARP_STATE_EMPTY = 0,
+ ETHARP_STATE_PENDING,
+ ETHARP_STATE_STABLE,
+ ETHARP_STATE_STABLE_REREQUESTING_1,
+ ETHARP_STATE_STABLE_REREQUESTING_2
+#if ETHARP_SUPPORT_STATIC_ENTRIES
+ ,ETHARP_STATE_STATIC
+#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
+};
+
+struct etharp_entry {
+#if ARP_QUEUEING
+ /** Pointer to queue of pending outgoing packets on this ARP entry. */
+ struct etharp_q_entry *q;
+#else /* ARP_QUEUEING */
+ /** Pointer to a single pending outgoing packet on this ARP entry. */
+ struct pbuf *q;
+#endif /* ARP_QUEUEING */
+ ip4_addr_t ipaddr;
+ struct netif *netif;
+ struct eth_addr ethaddr;
+ u16_t ctime;
+ u8_t state;
+};
+
+static struct etharp_entry arp_table[ARP_TABLE_SIZE];
+
+#if !LWIP_NETIF_HWADDRHINT
+static u8_t etharp_cached_entry;
+#endif /* !LWIP_NETIF_HWADDRHINT */
+
+/** Try hard to create a new entry - we want the IP address to appear in
+ the cache (even if this means removing an active entry or so). */
+#define ETHARP_FLAG_TRY_HARD 1
+#define ETHARP_FLAG_FIND_ONLY 2
+#if ETHARP_SUPPORT_STATIC_ENTRIES
+#define ETHARP_FLAG_STATIC_ENTRY 4
+#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
+
+#if LWIP_NETIF_HWADDRHINT
+#define ETHARP_SET_HINT(netif, hint) if (((netif) != NULL) && ((netif)->addr_hint != NULL)) \
+ *((netif)->addr_hint) = (hint);
+#else /* LWIP_NETIF_HWADDRHINT */
+#define ETHARP_SET_HINT(netif, hint) (etharp_cached_entry = (hint))
+#endif /* LWIP_NETIF_HWADDRHINT */
+
+
+/* Some checks, instead of etharp_init(): */
+#if (LWIP_ARP && (ARP_TABLE_SIZE > 0x7f))
+ #error "ARP_TABLE_SIZE must fit in an s8_t, you have to reduce it in your lwipopts.h"
+#endif
+
+
+static err_t etharp_request_dst(struct netif *netif, const ip4_addr_t *ipaddr, const struct eth_addr* hw_dst_addr);
+
+
+#if ARP_QUEUEING
+/**
+ * Free a complete queue of etharp entries
+ *
+ * @param q a qeueue of etharp_q_entry's to free
+ */
+static void
+free_etharp_q(struct etharp_q_entry *q)
+{
+ struct etharp_q_entry *r;
+ LWIP_ASSERT("q != NULL", q != NULL);
+ LWIP_ASSERT("q->p != NULL", q->p != NULL);
+ while (q) {
+ r = q;
+ q = q->next;
+ LWIP_ASSERT("r->p != NULL", (r->p != NULL));
+ pbuf_free(r->p);
+ memp_free(MEMP_ARP_QUEUE, r);
+ }
+}
+#else /* ARP_QUEUEING */
+
+/** Compatibility define: free the queued pbuf */
+#define free_etharp_q(q) pbuf_free(q)
+
+#endif /* ARP_QUEUEING */
+
+/** Clean up ARP table entries */
+static void
+etharp_free_entry(int i)
+{
+ /* remove from SNMP ARP index tree */
+ mib2_remove_arp_entry(arp_table[i].netif, &arp_table[i].ipaddr);
+ /* and empty packet queue */
+ if (arp_table[i].q != NULL) {
+ /* remove all queued packets */
+ LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_free_entry: freeing entry %"U16_F", packet queue %p.\n", (u16_t)i, (void *)(arp_table[i].q)));
+ free_etharp_q(arp_table[i].q);
+ arp_table[i].q = NULL;
+ }
+ /* recycle entry for re-use */
+ arp_table[i].state = ETHARP_STATE_EMPTY;
+#ifdef LWIP_DEBUG
+ /* for debugging, clean out the complete entry */
+ arp_table[i].ctime = 0;
+ arp_table[i].netif = NULL;
+ ip4_addr_set_zero(&arp_table[i].ipaddr);
+ arp_table[i].ethaddr = ethzero;
+#endif /* LWIP_DEBUG */
+}
+
+/**
+ * Clears expired entries in the ARP table.
+ *
+ * This function should be called every ARP_TMR_INTERVAL milliseconds (1 second),
+ * in order to expire entries in the ARP table.
+ */
+void
+etharp_tmr(void)
+{
+ u8_t i;
+
+ LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer\n"));
+ /* remove expired entries from the ARP table */
+ for (i = 0; i < ARP_TABLE_SIZE; ++i) {
+ u8_t state = arp_table[i].state;
+ if (state != ETHARP_STATE_EMPTY
+#if ETHARP_SUPPORT_STATIC_ENTRIES
+ && (state != ETHARP_STATE_STATIC)
+#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
+ ) {
+ arp_table[i].ctime++;
+ if ((arp_table[i].ctime >= ARP_MAXAGE) ||
+ ((arp_table[i].state == ETHARP_STATE_PENDING) &&
+ (arp_table[i].ctime >= ARP_MAXPENDING))) {
+ /* pending or stable entry has become old! */
+ LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer: expired %s entry %"U16_F".\n",
+ arp_table[i].state >= ETHARP_STATE_STABLE ? "stable" : "pending", (u16_t)i));
+ /* clean up entries that have just been expired */
+ etharp_free_entry(i);
+ } else if (arp_table[i].state == ETHARP_STATE_STABLE_REREQUESTING_1) {
+ /* Don't send more than one request every 2 seconds. */
+ arp_table[i].state = ETHARP_STATE_STABLE_REREQUESTING_2;
+ } else if (arp_table[i].state == ETHARP_STATE_STABLE_REREQUESTING_2) {
+ /* Reset state to stable, so that the next transmitted packet will
+ re-send an ARP request. */
+ arp_table[i].state = ETHARP_STATE_STABLE;
+ } else if (arp_table[i].state == ETHARP_STATE_PENDING) {
+ /* still pending, resend an ARP query */
+ etharp_request(arp_table[i].netif, &arp_table[i].ipaddr);
+ }
+ }
+ }
+}
+
+/**
+ * Search the ARP table for a matching or new entry.
+ *
+ * If an IP address is given, return a pending or stable ARP entry that matches
+ * the address. If no match is found, create a new entry with this address set,
+ * but in state ETHARP_EMPTY. The caller must check and possibly change the
+ * state of the returned entry.
+ *
+ * If ipaddr is NULL, return a initialized new entry in state ETHARP_EMPTY.
+ *
+ * In all cases, attempt to create new entries from an empty entry. If no
+ * empty entries are available and ETHARP_FLAG_TRY_HARD flag is set, recycle
+ * old entries. Heuristic choose the least important entry for recycling.
+ *
+ * @param ipaddr IP address to find in ARP cache, or to add if not found.
+ * @param flags @see definition of ETHARP_FLAG_*
+ * @param netif netif related to this address (used for NETIF_HWADDRHINT)
+ *
+ * @return The ARP entry index that matched or is created, ERR_MEM if no
+ * entry is found or could be recycled.
+ */
+static s8_t
+etharp_find_entry(const ip4_addr_t *ipaddr, u8_t flags, struct netif* netif)
+{
+ s8_t old_pending = ARP_TABLE_SIZE, old_stable = ARP_TABLE_SIZE;
+ s8_t empty = ARP_TABLE_SIZE;
+ u8_t i = 0;
+ /* oldest entry with packets on queue */
+ s8_t old_queue = ARP_TABLE_SIZE;
+ /* its age */
+ u16_t age_queue = 0, age_pending = 0, age_stable = 0;
+
+ LWIP_UNUSED_ARG(netif);
+
+ /**
+ * a) do a search through the cache, remember candidates
+ * b) select candidate entry
+ * c) create new entry
+ */
+
+ /* a) in a single search sweep, do all of this
+ * 1) remember the first empty entry (if any)
+ * 2) remember the oldest stable entry (if any)
+ * 3) remember the oldest pending entry without queued packets (if any)
+ * 4) remember the oldest pending entry with queued packets (if any)
+ * 5) search for a matching IP entry, either pending or stable
+ * until 5 matches, or all entries are searched for.
+ */
+
+ for (i = 0; i < ARP_TABLE_SIZE; ++i) {
+ u8_t state = arp_table[i].state;
+ /* no empty entry found yet and now we do find one? */
+ if ((empty == ARP_TABLE_SIZE) && (state == ETHARP_STATE_EMPTY)) {
+ LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_find_entry: found empty entry %"U16_F"\n", (u16_t)i));
+ /* remember first empty entry */
+ empty = i;
+ } else if (state != ETHARP_STATE_EMPTY) {
+ LWIP_ASSERT("state == ETHARP_STATE_PENDING || state >= ETHARP_STATE_STABLE",
+ state == ETHARP_STATE_PENDING || state >= ETHARP_STATE_STABLE);
+ /* if given, does IP address match IP address in ARP entry? */
+ if (ipaddr && ip4_addr_cmp(ipaddr, &arp_table[i].ipaddr)
+#if ETHARP_TABLE_MATCH_NETIF
+ && ((netif == NULL) || (netif == arp_table[i].netif))
+#endif /* ETHARP_TABLE_MATCH_NETIF */
+ ) {
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: found matching entry %"U16_F"\n", (u16_t)i));
+ /* found exact IP address match, simply bail out */
+ return i;
+ }
+ /* pending entry? */
+ if (state == ETHARP_STATE_PENDING) {
+ /* pending with queued packets? */
+ if (arp_table[i].q != NULL) {
+ if (arp_table[i].ctime >= age_queue) {
+ old_queue = i;
+ age_queue = arp_table[i].ctime;
+ }
+ } else
+ /* pending without queued packets? */
+ {
+ if (arp_table[i].ctime >= age_pending) {
+ old_pending = i;
+ age_pending = arp_table[i].ctime;
+ }
+ }
+ /* stable entry? */
+ } else if (state >= ETHARP_STATE_STABLE) {
+#if ETHARP_SUPPORT_STATIC_ENTRIES
+ /* don't record old_stable for static entries since they never expire */
+ if (state < ETHARP_STATE_STATIC)
+#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
+ {
+ /* remember entry with oldest stable entry in oldest, its age in maxtime */
+ if (arp_table[i].ctime >= age_stable) {
+ old_stable = i;
+ age_stable = arp_table[i].ctime;
+ }
+ }
+ }
+ }
+ }
+ /* { we have no match } => try to create a new entry */
+
+ /* don't create new entry, only search? */
+ if (((flags & ETHARP_FLAG_FIND_ONLY) != 0) ||
+ /* or no empty entry found and not allowed to recycle? */
+ ((empty == ARP_TABLE_SIZE) && ((flags & ETHARP_FLAG_TRY_HARD) == 0))) {
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: no empty entry found and not allowed to recycle\n"));
+ return (s8_t)ERR_MEM;
+ }
+
+ /* b) choose the least destructive entry to recycle:
+ * 1) empty entry
+ * 2) oldest stable entry
+ * 3) oldest pending entry without queued packets
+ * 4) oldest pending entry with queued packets
+ *
+ * { ETHARP_FLAG_TRY_HARD is set at this point }
+ */
+
+ /* 1) empty entry available? */
+ if (empty < ARP_TABLE_SIZE) {
+ i = empty;
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting empty entry %"U16_F"\n", (u16_t)i));
+ } else {
+ /* 2) found recyclable stable entry? */
+ if (old_stable < ARP_TABLE_SIZE) {
+ /* recycle oldest stable*/
+ i = old_stable;
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting oldest stable entry %"U16_F"\n", (u16_t)i));
+ /* no queued packets should exist on stable entries */
+ LWIP_ASSERT("arp_table[i].q == NULL", arp_table[i].q == NULL);
+ /* 3) found recyclable pending entry without queued packets? */
+ } else if (old_pending < ARP_TABLE_SIZE) {
+ /* recycle oldest pending */
+ i = old_pending;
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting oldest pending entry %"U16_F" (without queue)\n", (u16_t)i));
+ /* 4) found recyclable pending entry with queued packets? */
+ } else if (old_queue < ARP_TABLE_SIZE) {
+ /* recycle oldest pending (queued packets are free in etharp_free_entry) */
+ i = old_queue;
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting oldest pending entry %"U16_F", freeing packet queue %p\n", (u16_t)i, (void *)(arp_table[i].q)));
+ /* no empty or recyclable entries found */
+ } else {
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: no empty or recyclable entries found\n"));
+ return (s8_t)ERR_MEM;
+ }
+
+ /* { empty or recyclable entry found } */
+ LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE);
+ etharp_free_entry(i);
+ }
+
+ LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE);
+ LWIP_ASSERT("arp_table[i].state == ETHARP_STATE_EMPTY",
+ arp_table[i].state == ETHARP_STATE_EMPTY);
+
+ /* IP address given? */
+ if (ipaddr != NULL) {
+ /* set IP address */
+ ip4_addr_copy(arp_table[i].ipaddr, *ipaddr);
+ }
+ arp_table[i].ctime = 0;
+#if ETHARP_TABLE_MATCH_NETIF
+ arp_table[i].netif = netif;
+#endif /* ETHARP_TABLE_MATCH_NETIF*/
+ return (err_t)i;
+}
+
+/**
+ * Update (or insert) a IP/MAC address pair in the ARP cache.
+ *
+ * If a pending entry is resolved, any queued packets will be sent
+ * at this point.
+ *
+ * @param netif netif related to this entry (used for NETIF_ADDRHINT)
+ * @param ipaddr IP address of the inserted ARP entry.
+ * @param ethaddr Ethernet address of the inserted ARP entry.
+ * @param flags @see definition of ETHARP_FLAG_*
+ *
+ * @return
+ * - ERR_OK Successfully updated ARP cache.
+ * - ERR_MEM If we could not add a new ARP entry when ETHARP_FLAG_TRY_HARD was set.
+ * - ERR_ARG Non-unicast address given, those will not appear in ARP cache.
+ *
+ * @see pbuf_free()
+ */
+static err_t
+etharp_update_arp_entry(struct netif *netif, const ip4_addr_t *ipaddr, struct eth_addr *ethaddr, u8_t flags)
+{
+ s8_t i;
+ LWIP_ASSERT("netif->hwaddr_len == ETH_HWADDR_LEN", netif->hwaddr_len == ETH_HWADDR_LEN);
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_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),
+ (u16_t)ethaddr->addr[0], (u16_t)ethaddr->addr[1], (u16_t)ethaddr->addr[2],
+ (u16_t)ethaddr->addr[3], (u16_t)ethaddr->addr[4], (u16_t)ethaddr->addr[5]));
+ /* non-unicast address? */
+ if (ip4_addr_isany(ipaddr) ||
+ ip4_addr_isbroadcast(ipaddr, netif) ||
+ ip4_addr_ismulticast(ipaddr)) {
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_update_arp_entry: will not add non-unicast IP address to ARP cache\n"));
+ return ERR_ARG;
+ }
+ /* find or create ARP entry */
+ i = etharp_find_entry(ipaddr, flags, netif);
+ /* 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].state = ETHARP_STATE_STATIC;
+ } else if (arp_table[i].state == ETHARP_STATE_STATIC) {
+ /* found entry is a static type, don't overwrite it */
+ return ERR_VAL;
+ } else
+#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
+ {
+ /* mark it stable */
+ arp_table[i].state = ETHARP_STATE_STABLE;
+ }
+
+ /* record network interface */
+ arp_table[i].netif = netif;
+ /* insert in SNMP ARP index tree */
+ mib2_add_arp_entry(netif, &arp_table[i].ipaddr);
+
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_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;
+ /* this is where we will send out queued packets! */
+#if ARP_QUEUEING
+ 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);
+#else /* ARP_QUEUEING */
+ if (arp_table[i].q != NULL) {
+ struct pbuf *p = arp_table[i].q;
+ arp_table[i].q = NULL;
+#endif /* ARP_QUEUEING */
+ /* send the queued IP packet */
+ ethernet_output(netif, p, (struct eth_addr*)(netif->hwaddr), ethaddr, ETHTYPE_IP);
+ /* free the queued IP packet */
+ pbuf_free(p);
+ }
+ 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(const ip4_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),
+ (u16_t)ethaddr->addr[0], (u16_t)ethaddr->addr[1], (u16_t)ethaddr->addr[2],
+ (u16_t)ethaddr->addr[3], (u16_t)ethaddr->addr[4], (u16_t)ethaddr->addr[5]));
+
+ netif = ip4_route(ipaddr);
+ if (netif == NULL) {
+ return ERR_RTE;
+ }
+
+ return etharp_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(const ip4_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 = etharp_find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY, NULL);
+ /* bail out if no entry could be found */
+ if (i < 0) {
+ return (err_t)i;
+ }
+
+ if (arp_table[i].state != ETHARP_STATE_STATIC) {
+ /* entry wasn't a static entry, cannot remove it */
+ return ERR_ARG;
+ }
+ /* entry found, free it */
+ etharp_free_entry(i);
+ return ERR_OK;
+}
+#endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
+
+/**
+ * Remove all ARP table entries of the specified netif.
+ *
+ * @param netif points to a network interface
+ */
+void
+etharp_cleanup_netif(struct netif *netif)
+{
+ u8_t i;
+
+ for (i = 0; i < ARP_TABLE_SIZE; ++i) {
+ u8_t state = arp_table[i].state;
+ if ((state != ETHARP_STATE_EMPTY) && (arp_table[i].netif == netif)) {
+ etharp_free_entry(i);
+ }
+ }
+}
+
+/**
+ * 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, const ip4_addr_t *ipaddr,
+ struct eth_addr **eth_ret, const ip4_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 = etharp_find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY, netif);
+ 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;
+}
+
+/**
+ * Possibility to iterate over stable ARP table entries
+ *
+ * @param i entry number, 0 to ARP_TABLE_SIZE
+ * @param ipaddr return value: IP address
+ * @param netif return value: points to interface
+ * @param eth_ret return value: ETH address
+ * @return 1 on valid index, 0 otherwise
+ */
+u8_t
+etharp_get_entry(u8_t i, ip4_addr_t **ipaddr, struct netif **netif, struct eth_addr **eth_ret)
+{
+ LWIP_ASSERT("ipaddr != NULL", ipaddr != NULL);
+ LWIP_ASSERT("netif != NULL", netif != NULL);
+ LWIP_ASSERT("eth_ret != NULL", eth_ret != NULL);
+
+ if((i < ARP_TABLE_SIZE) && (arp_table[i].state >= ETHARP_STATE_STABLE)) {
+ *ipaddr = &arp_table[i].ipaddr;
+ *netif = arp_table[i].netif;
+ *eth_ret = &arp_table[i].ethaddr;
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+/**
+ * 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 p The ARP packet that arrived on netif. Is freed by this function.
+ * @param netif The lwIP network interface on which the ARP packet pbuf arrived.
+ *
+ * @return NULL
+ *
+ * @see pbuf_free()
+ */
+void
+etharp_input(struct pbuf *p, struct netif *netif)
+{
+ struct etharp_hdr *hdr;
+ /* these are aligned properly, whereas the ARP header fields might not be */
+ ip4_addr_t sipaddr, dipaddr;
+ u8_t for_us;
+
+ LWIP_ERROR("netif != NULL", (netif != NULL), return;);
+
+ hdr = (struct etharp_hdr *)p->payload;
+
+ /* RFC 826 "Packet Reception": */
+ if ((hdr->hwtype != PP_HTONS(HWTYPE_ETHERNET)) ||
+ (hdr->hwlen != ETH_HWADDR_LEN) ||
+ (hdr->protolen != sizeof(ip4_addr_t)) ||
+ (hdr->proto != PP_HTONS(ETHTYPE_IP))) {
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
+ ("etharp_input: packet dropped, wrong hw type, hwlen, proto, protolen or ethernet type (%"U16_F"/%"U16_F"/%"U16_F"/%"U16_F")\n",
+ hdr->hwtype, (u16_t)hdr->hwlen, hdr->proto, (u16_t)hdr->protolen));
+ 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 continuously 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 ip4_addr2 to aligned ip4_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 (ip4_addr_isany_val(*netif_ip4_addr(netif))) {
+ for_us = 0;
+ } else {
+ /* ARP packet directed to us? */
+ for_us = (u8_t)ip4_addr_cmp(&dipaddr, netif_ip4_addr(netif));
+ }
+
+ /* 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 */
+ etharp_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 possibly send out an IP packet that was queued on it. */
+
+ LWIP_DEBUGF (ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_input: incoming ARP request\n"));
+ /* ARP request for our address? */
+ if (for_us) {
+
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_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_ip4_addr(netif));
+
+ LWIP_ASSERT("netif->hwaddr_len must be the same as ETH_HWADDR_LEN for etharp!",
+ (netif->hwaddr_len == ETH_HWADDR_LEN));
+
+ /* hwtype, hwaddr_len, proto, protolen and the type in the ethernet header
+ are already correct, we tested that before */
+
+ ETHADDR16_COPY(&hdr->dhwaddr, &hdr->shwaddr);
+ ETHADDR16_COPY(&hdr->shwaddr, netif->hwaddr);
+
+ /* return ARP reply */
+#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) */
+ if (ip4_addr_islinklocal(netif_ip4_addr(netif))) {
+ ethernet_output(netif, p, &hdr->shwaddr, ðbroadcast, ETHTYPE_ARP);
+ } else
+#endif /* LWIP_AUTOIP */
+ {
+ ethernet_output(netif, p, &hdr->shwaddr, &hdr->dhwaddr, ETHTYPE_ARP);
+ }
+
+ /* we are not configured? */
+ } else if (ip4_addr_isany_val(*netif_ip4_addr(netif))) {
+ /* { for_us == 0 and netif->ip_addr.addr == 0 } */
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_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_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_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_input: ARP unknown opcode type %"S16_F"\n", htons(hdr->opcode)));
+ ETHARP_STATS_INC(etharp.err);
+ break;
+ }
+ /* free ARP packet */
+ pbuf_free(p);
+}
+
+/** Just a small helper function that sends a pbuf to an ethernet address
+ * in the arp_table specified by the index 'arp_idx'.
+ */
+static err_t
+etharp_output_to_arp_index(struct netif *netif, struct pbuf *q, u8_t arp_idx)
+{
+ LWIP_ASSERT("arp_table[arp_idx].state >= ETHARP_STATE_STABLE",
+ arp_table[arp_idx].state >= ETHARP_STATE_STABLE);
+ /* if arp table entry is about to expire: re-request it,
+ but only if its state is ETHARP_STATE_STABLE to prevent flooding the
+ network with ARP requests if this address is used frequently. */
+ if (arp_table[arp_idx].state == ETHARP_STATE_STABLE) {
+ if (arp_table[arp_idx].ctime >= ARP_AGE_REREQUEST_USED_BROADCAST) {
+ /* issue a standard request using broadcast */
+ if (etharp_request(netif, &arp_table[arp_idx].ipaddr) == ERR_OK) {
+ arp_table[arp_idx].state = ETHARP_STATE_STABLE_REREQUESTING_1;
+ }
+ } else if (arp_table[arp_idx].ctime >= ARP_AGE_REREQUEST_USED_UNICAST) {
+ /* issue a unicast request (for 15 seconds) to prevent unnecessary broadcast */
+ if (etharp_request_dst(netif, &arp_table[arp_idx].ipaddr, &arp_table[arp_idx].ethaddr) == ERR_OK) {
+ arp_table[arp_idx].state = ETHARP_STATE_STABLE_REREQUESTING_1;
+ }
+ }
+ }
+
+ return ethernet_output(netif, q, (struct eth_addr*)(netif->hwaddr), &arp_table[arp_idx].ethaddr, ETHTYPE_IP);
+}
+
+/**
+ * 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 ethernet_output().
+ */
+err_t
+etharp_output(struct netif *netif, struct pbuf *q, const ip4_addr_t *ipaddr)
+{
+ const struct eth_addr *dest;
+ struct eth_addr mcastaddr;
+ const ip4_addr_t *dst_addr = ipaddr;
+
+ LWIP_ASSERT("netif != NULL", netif != NULL);
+ LWIP_ASSERT("q != NULL", q != NULL);
+ LWIP_ASSERT("ipaddr != NULL", ipaddr != 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 (ip4_addr_isbroadcast(ipaddr, netif)) {
+ /* broadcast on Ethernet also */
+ dest = (const struct eth_addr *)ðbroadcast;
+ /* multicast destination IP address? */
+ } else if (ip4_addr_ismulticast(ipaddr)) {
+ /* Hash IP multicast address to MAC address.*/
+ mcastaddr.addr[0] = LL_IP4_MULTICAST_ADDR_0;
+ mcastaddr.addr[1] = LL_IP4_MULTICAST_ADDR_1;
+ mcastaddr.addr[2] = LL_IP4_MULTICAST_ADDR_2;
+ 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 {
+ s8_t i;
+ /* outside local network? if so, this can neither be a global broadcast nor
+ a subnet broadcast. */
+ if (!ip4_addr_netcmp(ipaddr, netif_ip4_addr(netif), netif_ip4_netmask(netif)) &&
+ !ip4_addr_islinklocal(ipaddr)) {
+#if LWIP_AUTOIP
+ struct ip_hdr *iphdr = (struct ip_hdr*)(size_t)q->payload;
+ /* According to RFC 3297, chapter 2.6.2 (Forwarding Rules), a packet with
+ a link-local source address must always be "directly to its destination
+ on the same physical link. The host MUST NOT send the packet to any
+ router for forwarding". */
+ if (!ip4_addr_islinklocal(&iphdr->src))
+#endif /* LWIP_AUTOIP */
+ {
+#ifdef LWIP_HOOK_ETHARP_GET_GW
+ /* For advanced routing, a single default gateway might not be enough, so get
+ the IP address of the gateway to handle the current destination address. */
+ dst_addr = LWIP_HOOK_ETHARP_GET_GW(netif, ipaddr);
+ if (dst_addr == NULL)
+#endif /* LWIP_HOOK_ETHARP_GET_GW */
+ {
+ /* interface has default gateway? */
+ if (!ip4_addr_isany_val(*netif_ip4_gw(netif))) {
+ /* send to hardware address of default gateway IP address */
+ dst_addr = netif_ip4_gw(netif);
+ /* 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) &&
+ (ip4_addr_cmp(dst_addr, &arp_table[etharp_cached_entry].ipaddr))) {
+ /* the per-pcb-cached entry is stable and the right one! */
+ ETHARP_STATS_INC(etharp.cachehit);
+ return etharp_output_to_arp_index(netif, q, etharp_cached_entry);
+ }
+#if LWIP_NETIF_HWADDRHINT
+ }
+ }
+#endif /* LWIP_NETIF_HWADDRHINT */
+
+ /* find stable entry: do this here since this is a critical path for
+ throughput and etharp_find_entry() is kind of slow */
+ for (i = 0; i < ARP_TABLE_SIZE; i++) {
+ if ((arp_table[i].state >= ETHARP_STATE_STABLE) &&
+ (ip4_addr_cmp(dst_addr, &arp_table[i].ipaddr))) {
+ /* found an existing, stable entry */
+ ETHARP_SET_HINT(netif, i);
+ return etharp_output_to_arp_index(netif, q, i);
+ }
+ }
+ /* no stable entry found, use the (slower) query function:
+ queue on destination Ethernet address belonging to ipaddr */
+ return etharp_query(netif, dst_addr, q);
+ }
+
+ /* continuation for multicast/broadcast destinations */
+ /* obtain source Ethernet address of the given interface */
+ /* send packet directly on the link */
+ return ethernet_output(netif, q, (struct eth_addr*)(netif->hwaddr), dest, ETHTYPE_IP);
+}
+
+/**
+ * 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, const ip4_addr_t *ipaddr, struct pbuf *q)
+{
+ struct eth_addr * srcaddr = (struct eth_addr *)netif->hwaddr;
+ err_t result = ERR_MEM;
+ int is_new_entry = 0;
+ s8_t i; /* ARP entry index */
+
+ /* non-unicast address? */
+ if (ip4_addr_isbroadcast(ipaddr, netif) ||
+ ip4_addr_ismulticast(ipaddr) ||
+ ip4_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 = etharp_find_entry(ipaddr, ETHARP_FLAG_TRY_HARD, netif);
+
+ /* 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) {
+ is_new_entry = 1;
+ arp_table[i].state = ETHARP_STATE_PENDING;
+ /* record network interface for re-sending arp request in etharp_tmr */
+ arp_table[i].netif = netif;
+ }
+
+ /* { 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 new entry? or an implicit query request? */
+ if (is_new_entry || (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 = ethernet_output(netif, q, srcaddr, &(arp_table[i].ethaddr), ETHTYPE_IP);
+ /* pending entry? (either just created or already pending */
+ } else if (arp_table[i].state == ETHARP_STATE_PENDING) {
+ /* entry is still pending, queue the given packet 'q' */
+ 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_LINK, 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 ... */
+#if ARP_QUEUEING
+ 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) {
+ unsigned int qlen = 0;
+ 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;
+ qlen++;
+ while (r->next != NULL) {
+ r = r->next;
+ qlen++;
+ }
+ r->next = new_entry;
+ } else {
+ /* queue did not exist, first item in queue */
+ arp_table[i].q = new_entry;
+ }
+#if ARP_QUEUE_LEN
+ if (qlen >= ARP_QUEUE_LEN) {
+ struct etharp_q_entry *old;
+ old = arp_table[i].q;
+ arp_table[i].q = arp_table[i].q->next;
+ pbuf_free(old->p);
+ memp_free(MEMP_ARP_QUEUE, old);
+ }
+#endif
+ 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;
+ }
+#else /* ARP_QUEUEING */
+ /* always queue one packet per ARP request only, freeing a previously queued packet */
+ if (arp_table[i].q != NULL) {
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: dropped previously queued packet %p for ARP entry %"S16_F"\n", (void *)q, (s16_t)i));
+ pbuf_free(arp_table[i].q);
+ }
+ arp_table[i].q = p;
+ result = ERR_OK;
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: queued packet %p on ARP entry %"S16_F"\n", (void *)q, (s16_t)i));
+#endif /* ARP_QUEUEING */
+ } 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;
+ }
+ }
+ 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
+ */
+static 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 ip4_addr_t *ipsrc_addr,
+ const struct eth_addr *hwdst_addr, const ip4_addr_t *ipdst_addr,
+ const u16_t opcode)
+{
+ struct pbuf *p;
+ err_t result = ERR_OK;
+ struct etharp_hdr *hdr;
+
+ LWIP_ASSERT("netif != NULL", netif != NULL);
+
+ /* allocate a pbuf for the outgoing ARP request packet */
+ p = pbuf_alloc(PBUF_LINK, SIZEOF_ETHARP_HDR, 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_HDR));
+
+ hdr = (struct etharp_hdr *)p->payload;
+ 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 ETH_HWADDR_LEN for etharp!",
+ (netif->hwaddr_len == ETH_HWADDR_LEN));
+
+ /* Write the ARP MAC-Addresses */
+ ETHADDR16_COPY(&hdr->shwaddr, hwsrc_addr);
+ ETHADDR16_COPY(&hdr->dhwaddr, hwdst_addr);
+ /* Copy struct ip4_addr2 to aligned ip4_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 = ETH_HWADDR_LEN;
+ hdr->protolen = sizeof(ip4_addr_t);
+
+ /* send ARP query */
+#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) */
+ if(ip4_addr_islinklocal(ipsrc_addr)) {
+ ethernet_output(netif, p, ethsrc_addr, ðbroadcast, ETHTYPE_ARP);
+ } else
+#endif /* LWIP_AUTOIP */
+ {
+ ethernet_output(netif, p, ethsrc_addr, ethdst_addr, ETHTYPE_ARP);
+ }
+
+ 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 to a specific eth address.
+ * Used to send unicast request to refresh the ARP table just before an entry
+ * times out
+ *
+ * @param netif the lwip network interface on which to send the request
+ * @param ipaddr the IP address for which to ask
+ * @param hw_dst_addr the ethernet address to send this packet to
+ * @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
+ */
+static err_t
+etharp_request_dst(struct netif *netif, const ip4_addr_t *ipaddr, const struct eth_addr* hw_dst_addr)
+{
+ return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, hw_dst_addr,
+ (struct eth_addr *)netif->hwaddr, netif_ip4_addr(netif), ðzero,
+ ipaddr, ARP_REQUEST);
+}
+
+/**
+ * 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, const ip4_addr_t *ipaddr)
+{
+ LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_request: sending ARP request.\n"));
+ return etharp_request_dst(netif, ipaddr, ðbroadcast);
+}
+#endif /* LWIP_IPV4 && LWIP_ARP */
+
+#endif /* LWIP_ARP || LWIP_ETHERNET */
http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/blob/f5a0f2a0/net/ip/lwip_base/src/core/ipv4/icmp.c
----------------------------------------------------------------------
diff --git a/net/ip/lwip_base/src/core/ipv4/icmp.c b/net/ip/lwip_base/src/core/ipv4/icmp.c
new file mode 100644
index 0000000..e60e448
--- /dev/null
+++ b/net/ip/lwip_base/src/core/ipv4/icmp.c
@@ -0,0 +1,393 @@
+/**
+ * @file
+ * ICMP - Internet Control Message Protocol
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <ad...@sics.se>
+ *
+ */
+
+/* Some ICMP messages should be passed to the transport protocols. This
+ is not implemented. */
+
+#include "lwip/opt.h"
+
+#if LWIP_IPV4 && LWIP_ICMP /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/icmp.h"
+#include "lwip/inet_chksum.h"
+#include "lwip/ip.h"
+#include "lwip/def.h"
+#include "lwip/stats.h"
+
+#include <string.h>
+
+/** Small optimization: set to 0 if incoming PBUF_POOL pbuf always can be
+ * used to modify and send a response packet (and to 1 if this is not the case,
+ * e.g. when link header is stripped of when receiving) */
+#ifndef LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN
+#define LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN 1
+#endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */
+
+/* The amount of data from the original packet to return in a dest-unreachable */
+#define ICMP_DEST_UNREACH_DATASIZE 8
+
+static void icmp_send_response(struct pbuf *p, u8_t type, u8_t code);
+
+/**
+ * Processes ICMP input packets, called from ip_input().
+ *
+ * Currently only processes icmp echo requests and sends
+ * out the echo response.
+ *
+ * @param p the icmp echo request packet, p->payload pointing to the icmp header
+ * @param inp the netif on which this packet was received
+ */
+void
+icmp_input(struct pbuf *p, struct netif *inp)
+{
+ u8_t type;
+#ifdef LWIP_DEBUG
+ u8_t code;
+#endif /* LWIP_DEBUG */
+ struct icmp_echo_hdr *iecho;
+ const struct ip_hdr *iphdr_in;
+ s16_t hlen;
+ const ip4_addr_t* src;
+
+ ICMP_STATS_INC(icmp.recv);
+ MIB2_STATS_INC(mib2.icmpinmsgs);
+
+ iphdr_in = ip4_current_header();
+ hlen = IPH_HL(iphdr_in) * 4;
+ if (hlen < IP_HLEN) {
+ LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short IP header (%"S16_F" bytes) received\n", hlen));
+ goto lenerr;
+ }
+ if (p->len < sizeof(u16_t)*2) {
+ LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short ICMP (%"U16_F" bytes) received\n", p->tot_len));
+ goto lenerr;
+ }
+
+ type = *((u8_t *)p->payload);
+#ifdef LWIP_DEBUG
+ code = *(((u8_t *)p->payload)+1);
+#endif /* LWIP_DEBUG */
+ switch (type) {
+ case ICMP_ER:
+ /* This is OK, echo reply might have been parsed by a raw PCB
+ (as obviously, an echo request has been sent, too). */
+ MIB2_STATS_INC(mib2.icmpinechoreps);
+ break;
+ case ICMP_ECHO:
+ MIB2_STATS_INC(mib2.icmpinechos);
+ src = ip4_current_dest_addr();
+ /* multicast destination address? */
+ if (ip4_addr_ismulticast(ip4_current_dest_addr())) {
+#if LWIP_MULTICAST_PING
+ /* For multicast, use address of receiving interface as source address */
+ src = netif_ip4_addr(inp);
+#else /* LWIP_MULTICAST_PING */
+ LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to multicast pings\n"));
+ goto icmperr;
+#endif /* LWIP_MULTICAST_PING */
+ }
+ /* broadcast destination address? */
+ if (ip4_addr_isbroadcast(ip4_current_dest_addr(), ip_current_netif())) {
+#if LWIP_BROADCAST_PING
+ /* For broadcast, use address of receiving interface as source address */
+ src = netif_ip4_addr(inp);
+#else /* LWIP_BROADCAST_PING */
+ LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to broadcast pings\n"));
+ goto icmperr;
+#endif /* LWIP_BROADCAST_PING */
+ }
+ LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n"));
+ if (p->tot_len < sizeof(struct icmp_echo_hdr)) {
+ LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n"));
+ goto lenerr;
+ }
+#if CHECKSUM_CHECK_ICMP
+ IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_ICMP) {
+ if (inet_chksum_pbuf(p) != 0) {
+ LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo\n"));
+ pbuf_free(p);
+ ICMP_STATS_INC(icmp.chkerr);
+ MIB2_STATS_INC(mib2.icmpinerrors);
+ return;
+ }
+ }
+#endif
+#if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN
+ if (pbuf_header(p, (hlen + PBUF_LINK_HLEN + PBUF_LINK_ENCAPSULATION_HLEN))) {
+ /* p is not big enough to contain link headers
+ * allocate a new one and copy p into it
+ */
+ struct pbuf *r;
+ /* allocate new packet buffer with space for link headers */
+ r = pbuf_alloc(PBUF_LINK, p->tot_len + hlen, PBUF_RAM);
+ if (r == NULL) {
+ LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: allocating new pbuf failed\n"));
+ goto icmperr;
+ }
+ if (r->len < hlen + sizeof(struct icmp_echo_hdr)) {
+ LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("first pbuf cannot hold the ICMP header"));
+ pbuf_free(r);
+ goto icmperr;
+ }
+ /* copy the ip header */
+ MEMCPY(r->payload, iphdr_in, hlen);
+ /* switch r->payload back to icmp header (cannot fail) */
+ if (pbuf_header(r, -hlen)) {
+ LWIP_ASSERT("icmp_input: moving r->payload to icmp header failed\n", 0);
+ pbuf_free(r);
+ goto icmperr;
+ }
+ /* copy the rest of the packet without ip header */
+ if (pbuf_copy(r, p) != ERR_OK) {
+ LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("icmp_input: copying to new pbuf failed"));
+ pbuf_free(r);
+ goto icmperr;
+ }
+ /* free the original p */
+ pbuf_free(p);
+ /* we now have an identical copy of p that has room for link headers */
+ p = r;
+ } else {
+ /* restore p->payload to point to icmp header (cannot fail) */
+ if (pbuf_header(p, -(s16_t)(hlen + PBUF_LINK_HLEN + PBUF_LINK_ENCAPSULATION_HLEN))) {
+ LWIP_ASSERT("icmp_input: restoring original p->payload failed\n", 0);
+ goto icmperr;
+ }
+ }
+#endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */
+ /* At this point, all checks are OK. */
+ /* We generate an answer by switching the dest and src ip addresses,
+ * setting the icmp type to ECHO_RESPONSE and updating the checksum. */
+ iecho = (struct icmp_echo_hdr *)p->payload;
+ if (pbuf_header(p, hlen)) {
+ LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("Can't move over header in packet"));
+ } else {
+ err_t ret;
+ struct ip_hdr *iphdr = (struct ip_hdr*)p->payload;
+ ip4_addr_copy(iphdr->src, *src);
+ ip4_addr_copy(iphdr->dest, *ip4_current_src_addr());
+ ICMPH_TYPE_SET(iecho, ICMP_ER);
+#if CHECKSUM_GEN_ICMP
+ IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_ICMP) {
+ /* adjust the checksum */
+ if (iecho->chksum > PP_HTONS(0xffffU - (ICMP_ECHO << 8))) {
+ iecho->chksum += PP_HTONS(ICMP_ECHO << 8) + 1;
+ } else {
+ iecho->chksum += PP_HTONS(ICMP_ECHO << 8);
+ }
+ }
+#if LWIP_CHECKSUM_CTRL_PER_NETIF
+ else {
+ iecho->chksum = 0;
+ }
+#endif /* LWIP_CHECKSUM_CTRL_PER_NETIF */
+#else /* CHECKSUM_GEN_ICMP */
+ iecho->chksum = 0;
+#endif /* CHECKSUM_GEN_ICMP */
+
+ /* Set the correct TTL and recalculate the header checksum. */
+ IPH_TTL_SET(iphdr, ICMP_TTL);
+ IPH_CHKSUM_SET(iphdr, 0);
+#if CHECKSUM_GEN_IP
+ IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_IP) {
+ IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, hlen));
+ }
+#endif /* CHECKSUM_GEN_IP */
+
+ ICMP_STATS_INC(icmp.xmit);
+ /* increase number of messages attempted to send */
+ MIB2_STATS_INC(mib2.icmpoutmsgs);
+ /* increase number of echo replies attempted to send */
+ MIB2_STATS_INC(mib2.icmpoutechoreps);
+
+ /* send an ICMP packet */
+ ret = ip4_output_if(p, src, LWIP_IP_HDRINCL,
+ ICMP_TTL, 0, IP_PROTO_ICMP, inp);
+ if (ret != ERR_OK) {
+ LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ip_output_if returned an error: %s\n", lwip_strerr(ret)));
+ }
+ }
+ break;
+ default:
+ if (type == ICMP_DUR) {
+ MIB2_STATS_INC(mib2.icmpindestunreachs);
+ } else if (type == ICMP_TE) {
+ MIB2_STATS_INC(mib2.icmpindestunreachs);
+ } else if (type == ICMP_PP) {
+ MIB2_STATS_INC(mib2.icmpinparmprobs);
+ } else if (type == ICMP_SQ) {
+ MIB2_STATS_INC(mib2.icmpinsrcquenchs);
+ } else if (type == ICMP_RD) {
+ MIB2_STATS_INC(mib2.icmpinredirects);
+ } else if (type == ICMP_TS) {
+ MIB2_STATS_INC(mib2.icmpintimestamps);
+ } else if (type == ICMP_TSR) {
+ MIB2_STATS_INC(mib2.icmpintimestampreps);
+ } else if (type == ICMP_AM) {
+ MIB2_STATS_INC(mib2.icmpinaddrmasks);
+ } else if (type == ICMP_AMR) {
+ MIB2_STATS_INC(mib2.icmpinaddrmaskreps);
+ }
+ LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ICMP type %"S16_F" code %"S16_F" not supported.\n",
+ (s16_t)type, (s16_t)code));
+ ICMP_STATS_INC(icmp.proterr);
+ ICMP_STATS_INC(icmp.drop);
+ }
+ pbuf_free(p);
+ return;
+lenerr:
+ pbuf_free(p);
+ ICMP_STATS_INC(icmp.lenerr);
+ MIB2_STATS_INC(mib2.icmpinerrors);
+ return;
+#if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN || !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING
+icmperr:
+ pbuf_free(p);
+ ICMP_STATS_INC(icmp.err);
+ MIB2_STATS_INC(mib2.icmpinerrors);
+ return;
+#endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN || !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING */
+}
+
+/**
+ * Send an icmp 'destination unreachable' packet, called from ip_input() if
+ * the transport layer protocol is unknown and from udp_input() if the local
+ * port is not bound.
+ *
+ * @param p the input packet for which the 'unreachable' should be sent,
+ * p->payload pointing to the IP header
+ * @param t type of the 'unreachable' packet
+ */
+void
+icmp_dest_unreach(struct pbuf *p, enum icmp_dur_type t)
+{
+ MIB2_STATS_INC(mib2.icmpoutdestunreachs);
+ icmp_send_response(p, ICMP_DUR, t);
+}
+
+#if IP_FORWARD || IP_REASSEMBLY
+/**
+ * Send a 'time exceeded' packet, called from ip_forward() if TTL is 0.
+ *
+ * @param p the input packet for which the 'time exceeded' should be sent,
+ * p->payload pointing to the IP header
+ * @param t type of the 'time exceeded' packet
+ */
+void
+icmp_time_exceeded(struct pbuf *p, enum icmp_te_type t)
+{
+ MIB2_STATS_INC(mib2.icmpouttimeexcds);
+ icmp_send_response(p, ICMP_TE, t);
+}
+
+#endif /* IP_FORWARD || IP_REASSEMBLY */
+
+/**
+ * Send an icmp packet in response to an incoming packet.
+ *
+ * @param p the input packet for which the 'unreachable' should be sent,
+ * p->payload pointing to the IP header
+ * @param type Type of the ICMP header
+ * @param code Code of the ICMP header
+ */
+static void
+icmp_send_response(struct pbuf *p, u8_t type, u8_t code)
+{
+ struct pbuf *q;
+ struct ip_hdr *iphdr;
+ /* we can use the echo header here */
+ struct icmp_echo_hdr *icmphdr;
+ ip4_addr_t iphdr_src;
+ struct netif *netif;
+
+ /* increase number of messages attempted to send */
+ MIB2_STATS_INC(mib2.icmpoutmsgs);
+
+ /* ICMP header + IP header + 8 bytes of data */
+ q = pbuf_alloc(PBUF_IP, sizeof(struct icmp_echo_hdr) + IP_HLEN + ICMP_DEST_UNREACH_DATASIZE,
+ PBUF_RAM);
+ if (q == NULL) {
+ LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded: failed to allocate pbuf for ICMP packet.\n"));
+ MIB2_STATS_INC(mib2.icmpouterrors);
+ return;
+ }
+ LWIP_ASSERT("check that first pbuf can hold icmp message",
+ (q->len >= (sizeof(struct icmp_echo_hdr) + IP_HLEN + ICMP_DEST_UNREACH_DATASIZE)));
+
+ iphdr = (struct ip_hdr *)p->payload;
+ LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded from "));
+ ip4_addr_debug_print_val(ICMP_DEBUG, iphdr->src);
+ LWIP_DEBUGF(ICMP_DEBUG, (" to "));
+ ip4_addr_debug_print_val(ICMP_DEBUG, iphdr->dest);
+ LWIP_DEBUGF(ICMP_DEBUG, ("\n"));
+
+ icmphdr = (struct icmp_echo_hdr *)q->payload;
+ icmphdr->type = type;
+ icmphdr->code = code;
+ icmphdr->id = 0;
+ icmphdr->seqno = 0;
+
+ /* copy fields from original packet */
+ SMEMCPY((u8_t *)q->payload + sizeof(struct icmp_echo_hdr), (u8_t *)p->payload,
+ IP_HLEN + ICMP_DEST_UNREACH_DATASIZE);
+
+ ip4_addr_copy(iphdr_src, iphdr->src);
+#ifdef LWIP_HOOK_IP4_ROUTE_SRC
+ {
+ ip4_addr_t iphdr_dst;
+ ip4_addr_copy(iphdr_dst, iphdr->dest);
+ netif = ip4_route_src(&iphdr_src, &iphdr_dst);
+ }
+#else
+ netif = ip4_route(&iphdr_src);
+#endif
+ if (netif != NULL) {
+ /* calculate checksum */
+ icmphdr->chksum = 0;
+#if CHECKSUM_GEN_ICMP
+ IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_ICMP) {
+ icmphdr->chksum = inet_chksum(icmphdr, q->len);
+ }
+#endif
+ ICMP_STATS_INC(icmp.xmit);
+ ip4_output_if(q, NULL, &iphdr_src, ICMP_TTL, 0, IP_PROTO_ICMP, netif);
+ }
+ pbuf_free(q);
+}
+
+#endif /* LWIP_IPV4 && LWIP_ICMP */