| /** |
| * @file |
| * Address Resolution Protocol module for IP over Ethernet |
| * |
| * Functionally, ARP is divided into two parts. The first maps an IP address |
| * to a physical address when sending a packet, and the second part answers |
| * requests from other machines for our physical address. |
| * |
| * This implementation complies with RFC 826 (Ethernet ARP). It supports |
| * Gratuitious ARP from RFC3220 (IP Mobility Support for IPv4) section 4.6 |
| * if an interface calls etharp_gratuitous(our_netif) upon address change. |
| */ |
| |
| /* |
| * Copyright (c) 2001-2003 Swedish Institute of Computer Science. |
| * Copyright (c) 2003-2004 Leon Woestenberg <leon.woestenberg@axon.tv> |
| * Copyright (c) 2003-2004 Axon Digital Design B.V., The Netherlands. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without modification, |
| * are permitted provided that the following conditions are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright notice, |
| * this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright notice, |
| * this list of conditions and the following disclaimer in the documentation |
| * and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT |
| * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT |
| * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
| * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY |
| * OF SUCH DAMAGE. |
| * |
| * This file is part of the lwIP TCP/IP stack. |
| * |
| */ |
| |
| #include "lwip/opt.h" |
| |
| #if LWIP_ARP /* don't build if not configured for use in lwipopts.h */ |
| |
| #include "lwip/inet.h" |
| #include "lwip/ip.h" |
| #include "lwip/stats.h" |
| #include "lwip/snmp.h" |
| #include "lwip/dhcp.h" |
| #include "lwip/autoip.h" |
| #include "netif/etharp.h" |
| |
| #if PPPOE_SUPPORT |
| #include "netif/ppp_oe.h" |
| #endif /* PPPOE_SUPPORT */ |
| |
| #include <string.h> |
| |
| /** the time an ARP entry stays valid after its last update, |
| * for ARP_TMR_INTERVAL = 5000, this is |
| * (240 * 5) seconds = 20 minutes. |
| */ |
| #define ARP_MAXAGE 240 |
| /** the time an ARP entry stays pending after first request, |
| * for ARP_TMR_INTERVAL = 5000, this is |
| * (2 * 5) seconds = 10 seconds. |
| * |
| * @internal Keep this number at least 2, otherwise it might |
| * run out instantly if the timeout occurs directly after a request. |
| */ |
| #define ARP_MAXPENDING 2 |
| |
| #define HWTYPE_ETHERNET 1 |
| |
| #define ARPH_HWLEN(hdr) (ntohs((hdr)->_hwlen_protolen) >> 8) |
| #define ARPH_PROTOLEN(hdr) (ntohs((hdr)->_hwlen_protolen) & 0xff) |
| |
| #define ARPH_HWLEN_SET(hdr, len) (hdr)->_hwlen_protolen = htons(ARPH_PROTOLEN(hdr) | ((len) << 8)) |
| #define ARPH_PROTOLEN_SET(hdr, len) (hdr)->_hwlen_protolen = htons((len) | (ARPH_HWLEN(hdr) << 8)) |
| |
| enum etharp_state { |
| ETHARP_STATE_EMPTY = 0, |
| ETHARP_STATE_PENDING, |
| ETHARP_STATE_STABLE |
| }; |
| |
| struct etharp_entry { |
| #if ARP_QUEUEING |
| /** |
| * Pointer to queue of pending outgoing packets on this ARP entry. |
| */ |
| struct etharp_q_entry *q; |
| #endif |
| struct ip_addr ipaddr; |
| struct eth_addr ethaddr; |
| enum etharp_state state; |
| u8_t ctime; |
| struct netif *netif; |
| }; |
| |
| const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}}; |
| const struct eth_addr ethzero = {{0,0,0,0,0,0}}; |
| static struct etharp_entry arp_table[ARP_TABLE_SIZE]; |
| #if !LWIP_NETIF_HWADDRHINT |
| static u8_t etharp_cached_entry; |
| #endif |
| |
| /** |
| * 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_TRY_HARD 1 |
| #define ETHARP_FIND_ONLY 2 |
| |
| #if LWIP_NETIF_HWADDRHINT |
| #define NETIF_SET_HINT(netif, hint) if (((netif) != NULL) && ((netif)->addr_hint != NULL)) \ |
| *((netif)->addr_hint) = (hint); |
| static s8_t find_entry(struct ip_addr *ipaddr, u8_t flags, struct netif *netif); |
| #else /* LWIP_NETIF_HWADDRHINT */ |
| static s8_t find_entry(struct ip_addr *ipaddr, u8_t flags); |
| #endif /* LWIP_NETIF_HWADDRHINT */ |
| |
| static err_t update_arp_entry(struct netif *netif, struct ip_addr *ipaddr, struct eth_addr *ethaddr, u8_t flags); |
| |
| |
| /* Some checks, instead of etharp_init(): */ |
| #if (LWIP_ARP && (ARP_TABLE_SIZE > 0x7f)) |
| #error "If you want to use ARP, ARP_TABLE_SIZE must fit in an s8_t, so, you have to reduce it in your lwipopts.h" |
| #endif |
| |
| |
| #if ARP_QUEUEING |
| /** |
| * Free a complete queue of etharp entries |
| * |
| * @param q a qeueue of etharp_q_entry's to free |
| */ |
| static void |
| free_etharp_q(struct etharp_q_entry *q) |
| { |
| struct etharp_q_entry *r; |
| LWIP_ASSERT("q != NULL", q != NULL); |
| LWIP_ASSERT("q->p != NULL", q->p != NULL); |
| while (q) { |
| r = q; |
| q = q->next; |
| LWIP_ASSERT("r->p != NULL", (r->p != NULL)); |
| pbuf_free(r->p); |
| memp_free(MEMP_ARP_QUEUE, r); |
| } |
| } |
| #endif |
| |
| /** |
| * Clears expired entries in the ARP table. |
| * |
| * This function should be called every ETHARP_TMR_INTERVAL microseconds (5 seconds), |
| * in order to expire entries in the ARP table. |
| */ |
| void |
| etharp_tmr(void) |
| { |
| u8_t i; |
| |
| LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer\n")); |
| /* remove expired entries from the ARP table */ |
| for (i = 0; i < ARP_TABLE_SIZE; ++i) { |
| arp_table[i].ctime++; |
| if (((arp_table[i].state == ETHARP_STATE_STABLE) && |
| (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 */ |
| /* remove from SNMP ARP index tree */ |
| snmp_delete_arpidx_tree(arp_table[i].netif, &arp_table[i].ipaddr); |
| #if ARP_QUEUEING |
| /* and empty packet queue */ |
| if (arp_table[i].q != NULL) { |
| /* remove all queued packets */ |
| LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer: freeing entry %"U16_F", packet queue %p.\n", (u16_t)i, (void *)(arp_table[i].q))); |
| free_etharp_q(arp_table[i].q); |
| arp_table[i].q = NULL; |
| } |
| #endif |
| /* recycle entry for re-use */ |
| arp_table[i].state = ETHARP_STATE_EMPTY; |
| } |
| #if ARP_QUEUEING |
| /* still pending entry? (not expired) */ |
| if (arp_table[i].state == ETHARP_STATE_PENDING) { |
| /* resend an ARP query here? */ |
| } |
| #endif |
| } |
| } |
| |
| /** |
| * 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_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 |
| * - ETHARP_TRY_HARD: Try hard to create a entry by allowing recycling of |
| * active (stable or pending) entries. |
| * |
| * @return The ARP entry index that matched or is created, ERR_MEM if no |
| * entry is found or could be recycled. |
| */ |
| static s8_t |
| #if LWIP_NETIF_HWADDRHINT |
| find_entry(struct ip_addr *ipaddr, u8_t flags, struct netif *netif) |
| #else /* LWIP_NETIF_HWADDRHINT */ |
| find_entry(struct ip_addr *ipaddr, u8_t flags) |
| #endif /* LWIP_NETIF_HWADDRHINT */ |
| { |
| s8_t old_pending = ARP_TABLE_SIZE, old_stable = ARP_TABLE_SIZE; |
| s8_t empty = ARP_TABLE_SIZE; |
| u8_t i = 0, age_pending = 0, age_stable = 0; |
| #if ARP_QUEUEING |
| /* oldest entry with packets on queue */ |
| s8_t old_queue = ARP_TABLE_SIZE; |
| /* its age */ |
| u8_t age_queue = 0; |
| #endif |
| |
| /* First, test if the last call to this function asked for the |
| * same address. If so, we're really fast! */ |
| if (ipaddr) { |
| /* ipaddr to search for was given */ |
| #if LWIP_NETIF_HWADDRHINT |
| if ((netif != NULL) && (netif->addr_hint != NULL)) { |
| /* per-pcb cached entry was given */ |
| u8_t per_pcb_cache = *(netif->addr_hint); |
| if ((per_pcb_cache < ARP_TABLE_SIZE) && arp_table[per_pcb_cache].state == ETHARP_STATE_STABLE) { |
| /* the per-pcb-cached entry is stable */ |
| if (ip_addr_cmp(ipaddr, &arp_table[per_pcb_cache].ipaddr)) { |
| /* per-pcb cached entry was the right one! */ |
| ETHARP_STATS_INC(etharp.cachehit); |
| return per_pcb_cache; |
| } |
| } |
| } |
| #else /* #if LWIP_NETIF_HWADDRHINT */ |
| if (arp_table[etharp_cached_entry].state == ETHARP_STATE_STABLE) { |
| /* the cached entry is stable */ |
| if (ip_addr_cmp(ipaddr, &arp_table[etharp_cached_entry].ipaddr)) { |
| /* cached entry was the right one! */ |
| ETHARP_STATS_INC(etharp.cachehit); |
| return etharp_cached_entry; |
| } |
| } |
| #endif /* #if LWIP_NETIF_HWADDRHINT */ |
| } |
| |
| /** |
| * 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) { |
| /* no empty entry found yet and now we do find one? */ |
| if ((empty == ARP_TABLE_SIZE) && (arp_table[i].state == ETHARP_STATE_EMPTY)) { |
| LWIP_DEBUGF(ETHARP_DEBUG, ("find_entry: found empty entry %"U16_F"\n", (u16_t)i)); |
| /* remember first empty entry */ |
| empty = i; |
| } |
| /* pending entry? */ |
| else if (arp_table[i].state == ETHARP_STATE_PENDING) { |
| /* if given, does IP address match IP address in ARP entry? */ |
| if (ipaddr && ip_addr_cmp(ipaddr, &arp_table[i].ipaddr)) { |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: found matching pending entry %"U16_F"\n", (u16_t)i)); |
| /* found exact IP address match, simply bail out */ |
| #if LWIP_NETIF_HWADDRHINT |
| NETIF_SET_HINT(netif, i); |
| #else /* #if LWIP_NETIF_HWADDRHINT */ |
| etharp_cached_entry = i; |
| #endif /* #if LWIP_NETIF_HWADDRHINT */ |
| return i; |
| #if ARP_QUEUEING |
| /* pending with queued packets? */ |
| } else if (arp_table[i].q != NULL) { |
| if (arp_table[i].ctime >= age_queue) { |
| old_queue = i; |
| age_queue = arp_table[i].ctime; |
| } |
| #endif |
| /* pending without queued packets? */ |
| } else { |
| if (arp_table[i].ctime >= age_pending) { |
| old_pending = i; |
| age_pending = arp_table[i].ctime; |
| } |
| } |
| } |
| /* stable entry? */ |
| else if (arp_table[i].state == ETHARP_STATE_STABLE) { |
| /* if given, does IP address match IP address in ARP entry? */ |
| if (ipaddr && ip_addr_cmp(ipaddr, &arp_table[i].ipaddr)) { |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: found matching stable entry %"U16_F"\n", (u16_t)i)); |
| /* found exact IP address match, simply bail out */ |
| #if LWIP_NETIF_HWADDRHINT |
| NETIF_SET_HINT(netif, i); |
| #else /* #if LWIP_NETIF_HWADDRHINT */ |
| etharp_cached_entry = i; |
| #endif /* #if LWIP_NETIF_HWADDRHINT */ |
| return i; |
| /* remember entry with oldest stable entry in oldest, its age in maxtime */ |
| } else 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 */ |
| |
| /* no empty entry found and not allowed to recycle? */ |
| if (((empty == ARP_TABLE_SIZE) && ((flags & ETHARP_TRY_HARD) == 0)) |
| /* or don't create new entry, only search? */ |
| || ((flags & ETHARP_FIND_ONLY) != 0)) { |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: no empty entry found and not allowed to recycle\n")); |
| return (s8_t)ERR_MEM; |
| } |
| |
| /* b) choose the least destructive entry to recycle: |
| * 1) empty entry |
| * 2) oldest stable entry |
| * 3) oldest pending entry without queued packets |
| * 4) oldest pending entry with queued packets |
| * |
| * { ETHARP_TRY_HARD is set at this point } |
| */ |
| |
| /* 1) empty entry available? */ |
| if (empty < ARP_TABLE_SIZE) { |
| i = empty; |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting empty entry %"U16_F"\n", (u16_t)i)); |
| } |
| /* 2) found recyclable stable entry? */ |
| else if (old_stable < ARP_TABLE_SIZE) { |
| /* recycle oldest stable*/ |
| i = old_stable; |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting oldest stable entry %"U16_F"\n", (u16_t)i)); |
| #if ARP_QUEUEING |
| /* no queued packets should exist on stable entries */ |
| LWIP_ASSERT("arp_table[i].q == NULL", arp_table[i].q == NULL); |
| #endif |
| /* 3) found recyclable pending entry without queued packets? */ |
| } else if (old_pending < ARP_TABLE_SIZE) { |
| /* recycle oldest pending */ |
| i = old_pending; |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting oldest pending entry %"U16_F" (without queue)\n", (u16_t)i)); |
| #if ARP_QUEUEING |
| /* 4) found recyclable pending entry with queued packets? */ |
| } else if (old_queue < ARP_TABLE_SIZE) { |
| /* recycle oldest pending */ |
| i = old_queue; |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting oldest pending entry %"U16_F", freeing packet queue %p\n", (u16_t)i, (void *)(arp_table[i].q))); |
| free_etharp_q(arp_table[i].q); |
| arp_table[i].q = NULL; |
| #endif |
| /* no empty or recyclable entries found */ |
| } else { |
| return (s8_t)ERR_MEM; |
| } |
| |
| /* { empty or recyclable entry found } */ |
| LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE); |
| |
| if (arp_table[i].state != ETHARP_STATE_EMPTY) |
| { |
| snmp_delete_arpidx_tree(arp_table[i].netif, &arp_table[i].ipaddr); |
| } |
| /* recycle entry (no-op for an already empty entry) */ |
| arp_table[i].state = ETHARP_STATE_EMPTY; |
| |
| /* IP address given? */ |
| if (ipaddr != NULL) { |
| /* set IP address */ |
| ip_addr_set(&arp_table[i].ipaddr, ipaddr); |
| } |
| arp_table[i].ctime = 0; |
| #if LWIP_NETIF_HWADDRHINT |
| NETIF_SET_HINT(netif, i); |
| #else /* #if LWIP_NETIF_HWADDRHINT */ |
| etharp_cached_entry = i; |
| #endif /* #if LWIP_NETIF_HWADDRHINT */ |
| return (err_t)i; |
| } |
| |
| /** |
| * Send an IP packet on the network using netif->linkoutput |
| * The ethernet header is filled in before sending. |
| * |
| * @params netif the lwIP network interface on which to send the packet |
| * @params p the packet to send, p->payload pointing to the (uninitialized) ethernet header |
| * @params src the source MAC address to be copied into the ethernet header |
| * @params dst the destination MAC address to be copied into the ethernet header |
| * @return ERR_OK if the packet was sent, any other err_t on failure |
| */ |
| static err_t |
| etharp_send_ip(struct netif *netif, struct pbuf *p, struct eth_addr *src, struct eth_addr *dst) |
| { |
| struct eth_hdr *ethhdr = p->payload; |
| u8_t k; |
| |
| LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!", |
| (netif->hwaddr_len == ETHARP_HWADDR_LEN)); |
| k = ETHARP_HWADDR_LEN; |
| while(k > 0) { |
| k--; |
| ethhdr->dest.addr[k] = dst->addr[k]; |
| ethhdr->src.addr[k] = src->addr[k]; |
| } |
| ethhdr->type = htons(ETHTYPE_IP); |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_send_ip: sending packet %p\n", (void *)p)); |
| /* send the packet */ |
| return netif->linkoutput(netif, p); |
| } |
| |
| /** |
| * Update (or insert) a IP/MAC address pair in the ARP cache. |
| * |
| * If a pending entry is resolved, any queued packets will be sent |
| * at this point. |
| * |
| * @param ipaddr IP address of the inserted ARP entry. |
| * @param ethaddr Ethernet address of the inserted ARP entry. |
| * @param flags Defines behaviour: |
| * - ETHARP_TRY_HARD Allows ARP to insert this as a new item. If not specified, |
| * only existing ARP entries will be updated. |
| * |
| * @return |
| * - ERR_OK Succesfully updated ARP cache. |
| * - ERR_MEM If we could not add a new ARP entry when ETHARP_TRY_HARD was set. |
| * - ERR_ARG Non-unicast address given, those will not appear in ARP cache. |
| * |
| * @see pbuf_free() |
| */ |
| static err_t |
| update_arp_entry(struct netif *netif, struct ip_addr *ipaddr, struct eth_addr *ethaddr, u8_t flags) |
| { |
| s8_t i; |
| u8_t k; |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("update_arp_entry()\n")); |
| LWIP_ASSERT("netif->hwaddr_len == ETHARP_HWADDR_LEN", netif->hwaddr_len == ETHARP_HWADDR_LEN); |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("update_arp_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F" - %02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F"\n", |
| ip4_addr1(ipaddr), ip4_addr2(ipaddr), ip4_addr3(ipaddr), ip4_addr4(ipaddr), |
| ethaddr->addr[0], ethaddr->addr[1], ethaddr->addr[2], |
| ethaddr->addr[3], ethaddr->addr[4], ethaddr->addr[5])); |
| /* non-unicast address? */ |
| if (ip_addr_isany(ipaddr) || |
| ip_addr_isbroadcast(ipaddr, netif) || |
| ip_addr_ismulticast(ipaddr)) { |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("update_arp_entry: will not add non-unicast IP address to ARP cache\n")); |
| return ERR_ARG; |
| } |
| /* find or create ARP entry */ |
| #if LWIP_NETIF_HWADDRHINT |
| i = find_entry(ipaddr, flags, netif); |
| #else /* LWIP_NETIF_HWADDRHINT */ |
| i = find_entry(ipaddr, flags); |
| #endif /* LWIP_NETIF_HWADDRHINT */ |
| /* bail out if no entry could be found */ |
| if (i < 0) |
| return (err_t)i; |
| |
| /* mark it stable */ |
| arp_table[i].state = ETHARP_STATE_STABLE; |
| /* record network interface */ |
| arp_table[i].netif = netif; |
| |
| /* insert in SNMP ARP index tree */ |
| snmp_insert_arpidx_tree(netif, &arp_table[i].ipaddr); |
| |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("update_arp_entry: updating stable entry %"S16_F"\n", (s16_t)i)); |
| /* update address */ |
| k = ETHARP_HWADDR_LEN; |
| while (k > 0) { |
| k--; |
| arp_table[i].ethaddr.addr[k] = ethaddr->addr[k]; |
| } |
| /* reset time stamp */ |
| arp_table[i].ctime = 0; |
| #if ARP_QUEUEING |
| /* this is where we will send out queued packets! */ |
| while (arp_table[i].q != NULL) { |
| struct pbuf *p; |
| /* remember remainder of queue */ |
| struct etharp_q_entry *q = arp_table[i].q; |
| /* pop first item off the queue */ |
| arp_table[i].q = q->next; |
| /* get the packet pointer */ |
| p = q->p; |
| /* now queue entry can be freed */ |
| memp_free(MEMP_ARP_QUEUE, q); |
| /* send the queued IP packet */ |
| etharp_send_ip(netif, p, (struct eth_addr*)(netif->hwaddr), ethaddr); |
| /* free the queued IP packet */ |
| pbuf_free(p); |
| } |
| #endif |
| return ERR_OK; |
| } |
| |
| /** |
| * 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, struct ip_addr *ipaddr, |
| struct eth_addr **eth_ret, struct ip_addr **ip_ret) |
| { |
| s8_t i; |
| |
| LWIP_UNUSED_ARG(netif); |
| |
| #if LWIP_NETIF_HWADDRHINT |
| i = find_entry(ipaddr, ETHARP_FIND_ONLY, NULL); |
| #else /* LWIP_NETIF_HWADDRHINT */ |
| i = find_entry(ipaddr, ETHARP_FIND_ONLY); |
| #endif /* LWIP_NETIF_HWADDRHINT */ |
| 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; |
| } |
| |
| /** |
| * Updates the ARP table using the given IP packet. |
| * |
| * Uses the incoming IP packet's source address to update the |
| * ARP cache for the local network. The function does not alter |
| * or free the packet. This function must be called before the |
| * packet p is passed to the IP layer. |
| * |
| * @param netif The lwIP network interface on which the IP packet pbuf arrived. |
| * @param p The IP packet that arrived on netif. |
| * |
| * @return NULL |
| * |
| * @see pbuf_free() |
| */ |
| void |
| etharp_ip_input(struct netif *netif, struct pbuf *p) |
| { |
| struct eth_hdr *ethhdr; |
| struct ip_hdr *iphdr; |
| LWIP_ERROR("netif != NULL", (netif != NULL), return;); |
| /* Only insert an entry if the source IP address of the |
| incoming IP packet comes from a host on the local network. */ |
| ethhdr = p->payload; |
| iphdr = (struct ip_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR); |
| #if ETHARP_SUPPORT_VLAN |
| if (ethhdr->type == ETHTYPE_VLAN) { |
| iphdr = (struct ip_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR); |
| } |
| #endif /* ETHARP_SUPPORT_VLAN */ |
| |
| /* source is not on the local network? */ |
| if (!ip_addr_netcmp(&(iphdr->src), &(netif->ip_addr), &(netif->netmask))) { |
| /* do nothing */ |
| return; |
| } |
| |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_ip_input: updating ETHARP table.\n")); |
| /* update ARP table */ |
| /* @todo We could use ETHARP_TRY_HARD if we think we are going to talk |
| * back soon (for example, if the destination IP address is ours. */ |
| update_arp_entry(netif, &(iphdr->src), &(ethhdr->src), 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 netif The lwIP network interface on which the ARP packet pbuf arrived. |
| * @param ethaddr Ethernet address of netif. |
| * @param p The ARP packet that arrived on netif. Is freed by this function. |
| * |
| * @return NULL |
| * |
| * @see pbuf_free() |
| */ |
| void |
| etharp_arp_input(struct netif *netif, struct eth_addr *ethaddr, struct pbuf *p) |
| { |
| struct etharp_hdr *hdr; |
| struct eth_hdr *ethhdr; |
| /* these are aligned properly, whereas the ARP header fields might not be */ |
| struct ip_addr sipaddr, dipaddr; |
| u8_t i; |
| u8_t for_us; |
| #if LWIP_AUTOIP |
| const u8_t * ethdst_hwaddr; |
| #endif /* LWIP_AUTOIP */ |
| |
| LWIP_ERROR("netif != NULL", (netif != NULL), return;); |
| |
| /* drop short ARP packets: we have to check for p->len instead of p->tot_len here |
| since a struct etharp_hdr is pointed to p->payload, so it musn't be chained! */ |
| if (p->len < SIZEOF_ETHARP_PACKET) { |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, |
| ("etharp_arp_input: packet dropped, too short (%"S16_F"/%"S16_F")\n", p->tot_len, |
| (s16_t)SIZEOF_ETHARP_PACKET)); |
| ETHARP_STATS_INC(etharp.lenerr); |
| ETHARP_STATS_INC(etharp.drop); |
| pbuf_free(p); |
| return; |
| } |
| |
| ethhdr = p->payload; |
| hdr = (struct etharp_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR); |
| #if ETHARP_SUPPORT_VLAN |
| if (ethhdr->type == ETHTYPE_VLAN) { |
| hdr = (struct etharp_hdr *)(((u8_t*)ethhdr) + SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR); |
| } |
| #endif /* ETHARP_SUPPORT_VLAN */ |
| |
| /* RFC 826 "Packet Reception": */ |
| if ((hdr->hwtype != htons(HWTYPE_ETHERNET)) || |
| (hdr->_hwlen_protolen != htons((ETHARP_HWADDR_LEN << 8) | sizeof(struct ip_addr))) || |
| (hdr->proto != htons(ETHTYPE_IP)) || |
| (ethhdr->type != htons(ETHTYPE_ARP))) { |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, |
| ("etharp_arp_input: packet dropped, wrong hw type, hwlen, proto, protolen or ethernet type (%"U16_F"/%"U16_F"/%"U16_F"/%"U16_F"/%"U16_F")\n", |
| hdr->hwtype, ARPH_HWLEN(hdr), hdr->proto, ARPH_PROTOLEN(hdr), ethhdr->type)); |
| ETHARP_STATS_INC(etharp.proterr); |
| ETHARP_STATS_INC(etharp.drop); |
| pbuf_free(p); |
| return; |
| } |
| ETHARP_STATS_INC(etharp.recv); |
| |
| #if LWIP_AUTOIP |
| /* We have to check if a host already has configured our random |
| * created link local address and continously check if there is |
| * a host with this IP-address so we can detect collisions */ |
| autoip_arp_reply(netif, hdr); |
| #endif /* LWIP_AUTOIP */ |
| |
| /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without |
| * structure packing (not using structure copy which breaks strict-aliasing rules). */ |
| SMEMCPY(&sipaddr, &hdr->sipaddr, sizeof(sipaddr)); |
| SMEMCPY(&dipaddr, &hdr->dipaddr, sizeof(dipaddr)); |
| |
| /* this interface is not configured? */ |
| if (netif->ip_addr.addr == 0) { |
| for_us = 0; |
| } else { |
| /* ARP packet directed to us? */ |
| for_us = ip_addr_cmp(&dipaddr, &(netif->ip_addr)); |
| } |
| |
| /* ARP message directed to us? */ |
| if (for_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. */ |
| update_arp_entry(netif, &sipaddr, &(hdr->shwaddr), ETHARP_TRY_HARD); |
| /* ARP message not directed to us? */ |
| } else { |
| /* update the source IP address in the cache, if present */ |
| update_arp_entry(netif, &sipaddr, &(hdr->shwaddr), 0); |
| } |
| |
| /* now act on the message itself */ |
| switch (htons(hdr->opcode)) { |
| /* ARP request? */ |
| case ARP_REQUEST: |
| /* ARP request. If it asked for our address, we send out a |
| * reply. In any case, we time-stamp any existing ARP entry, |
| * and possiby send out an IP packet that was queued on it. */ |
| |
| LWIP_DEBUGF (ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: incoming ARP request\n")); |
| /* ARP request for our address? */ |
| if (for_us) { |
| |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: replying to ARP request for our IP address\n")); |
| /* Re-use pbuf to send ARP reply. |
| Since we are re-using an existing pbuf, we can't call etharp_raw since |
| that would allocate a new pbuf. */ |
| hdr->opcode = htons(ARP_REPLY); |
| |
| hdr->dipaddr = hdr->sipaddr; |
| SMEMCPY(&hdr->sipaddr, &netif->ip_addr, sizeof(hdr->sipaddr)); |
| |
| LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!", |
| (netif->hwaddr_len == ETHARP_HWADDR_LEN)); |
| i = ETHARP_HWADDR_LEN; |
| #if LWIP_AUTOIP |
| /* If we are using Link-Local, ARP packets must be broadcast on the |
| * link layer. (See RFC3927 Section 2.5) */ |
| ethdst_hwaddr = ((netif->autoip != NULL) && (netif->autoip->state != AUTOIP_STATE_OFF)) ? (u8_t*)(ethbroadcast.addr) : hdr->shwaddr.addr; |
| #endif /* LWIP_AUTOIP */ |
| |
| while(i > 0) { |
| i--; |
| hdr->dhwaddr.addr[i] = hdr->shwaddr.addr[i]; |
| #if LWIP_AUTOIP |
| ethhdr->dest.addr[i] = ethdst_hwaddr[i]; |
| #else /* LWIP_AUTOIP */ |
| ethhdr->dest.addr[i] = hdr->shwaddr.addr[i]; |
| #endif /* LWIP_AUTOIP */ |
| hdr->shwaddr.addr[i] = ethaddr->addr[i]; |
| ethhdr->src.addr[i] = ethaddr->addr[i]; |
| } |
| |
| /* hwtype, hwaddr_len, proto, protolen and the type in the ethernet header |
| are already correct, we tested that before */ |
| |
| /* return ARP reply */ |
| netif->linkoutput(netif, p); |
| /* we are not configured? */ |
| } else if (netif->ip_addr.addr == 0) { |
| /* { for_us == 0 and netif->ip_addr.addr == 0 } */ |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: we are unconfigured, ARP request ignored.\n")); |
| /* request was not directed to us */ |
| } else { |
| /* { for_us == 0 and netif->ip_addr.addr != 0 } */ |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: ARP request was not for us.\n")); |
| } |
| break; |
| case ARP_REPLY: |
| /* ARP reply. We already updated the ARP cache earlier. */ |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: incoming ARP reply\n")); |
| #if (LWIP_DHCP && DHCP_DOES_ARP_CHECK) |
| /* DHCP wants to know about ARP replies from any host with an |
| * IP address also offered to us by the DHCP server. We do not |
| * want to take a duplicate IP address on a single network. |
| * @todo How should we handle redundant (fail-over) interfaces? */ |
| dhcp_arp_reply(netif, &sipaddr); |
| #endif |
| break; |
| default: |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: ARP unknown opcode type %"S16_F"\n", htons(hdr->opcode))); |
| ETHARP_STATS_INC(etharp.err); |
| break; |
| } |
| /* free ARP packet */ |
| pbuf_free(p); |
| } |
| |
| /** |
| * Resolve and fill-in Ethernet address header for outgoing IP packet. |
| * |
| * For IP multicast and broadcast, corresponding Ethernet addresses |
| * are selected and the packet is transmitted on the link. |
| * |
| * For unicast addresses, the packet is submitted to etharp_query(). In |
| * case the IP address is outside the local network, the IP address of |
| * the gateway is used. |
| * |
| * @param netif The lwIP network interface which the IP packet will be sent on. |
| * @param q The pbuf(s) containing the IP packet to be sent. |
| * @param ipaddr The IP address of the packet destination. |
| * |
| * @return |
| * - ERR_RTE No route to destination (no gateway to external networks), |
| * or the return type of either etharp_query() or etharp_send_ip(). |
| */ |
| err_t |
| etharp_output(struct netif *netif, struct pbuf *q, struct ip_addr *ipaddr) |
| { |
| struct eth_addr *dest, mcastaddr; |
| |
| /* make room for Ethernet header - should not fail */ |
| if (pbuf_header(q, sizeof(struct eth_hdr)) != 0) { |
| /* bail out */ |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, |
| ("etharp_output: could not allocate room for header.\n")); |
| LINK_STATS_INC(link.lenerr); |
| return ERR_BUF; |
| } |
| |
| /* assume unresolved Ethernet address */ |
| dest = NULL; |
| /* Determine on destination hardware address. Broadcasts and multicasts |
| * are special, other IP addresses are looked up in the ARP table. */ |
| |
| /* broadcast destination IP address? */ |
| if (ip_addr_isbroadcast(ipaddr, netif)) { |
| /* broadcast on Ethernet also */ |
| dest = (struct eth_addr *)ðbroadcast; |
| /* multicast destination IP address? */ |
| } else if (ip_addr_ismulticast(ipaddr)) { |
| /* Hash IP multicast address to MAC address.*/ |
| mcastaddr.addr[0] = 0x01; |
| mcastaddr.addr[1] = 0x00; |
| mcastaddr.addr[2] = 0x5e; |
| mcastaddr.addr[3] = ip4_addr2(ipaddr) & 0x7f; |
| mcastaddr.addr[4] = ip4_addr3(ipaddr); |
| mcastaddr.addr[5] = ip4_addr4(ipaddr); |
| /* destination Ethernet address is multicast */ |
| dest = &mcastaddr; |
| /* unicast destination IP address? */ |
| } else { |
| /* outside local network? */ |
| if (!ip_addr_netcmp(ipaddr, &(netif->ip_addr), &(netif->netmask))) { |
| /* interface has default gateway? */ |
| if (netif->gw.addr != 0) { |
| /* send to hardware address of default gateway IP address */ |
| ipaddr = &(netif->gw); |
| /* no default gateway available */ |
| } else { |
| /* no route to destination error (default gateway missing) */ |
| return ERR_RTE; |
| } |
| } |
| /* queue on destination Ethernet address belonging to ipaddr */ |
| return etharp_query(netif, ipaddr, q); |
| } |
| |
| /* continuation for multicast/broadcast destinations */ |
| /* obtain source Ethernet address of the given interface */ |
| /* send packet directly on the link */ |
| return etharp_send_ip(netif, q, (struct eth_addr*)(netif->hwaddr), dest); |
| } |
| |
| /** |
| * Send an ARP request for the given IP address and/or queue a packet. |
| * |
| * If the IP address was not yet in the cache, a pending ARP cache entry |
| * is added and an ARP request is sent for the given address. The packet |
| * is queued on this entry. |
| * |
| * If the IP address was already pending in the cache, a new ARP request |
| * is sent for the given address. The packet is queued on this entry. |
| * |
| * If the IP address was already stable in the cache, and a packet is |
| * given, it is directly sent and no ARP request is sent out. |
| * |
| * If the IP address was already stable in the cache, and no packet is |
| * given, an ARP request is sent out. |
| * |
| * @param netif The lwIP network interface on which ipaddr |
| * must be queried for. |
| * @param ipaddr The IP address to be resolved. |
| * @param q If non-NULL, a pbuf that must be delivered to the IP address. |
| * q is not freed by this function. |
| * |
| * @note q must only be ONE packet, not a packet queue! |
| * |
| * @return |
| * - ERR_BUF Could not make room for Ethernet header. |
| * - ERR_MEM Hardware address unknown, and no more ARP entries available |
| * to query for address or queue the packet. |
| * - ERR_MEM Could not queue packet due to memory shortage. |
| * - ERR_RTE No route to destination (no gateway to external networks). |
| * - ERR_ARG Non-unicast address given, those will not appear in ARP cache. |
| * |
| */ |
| err_t |
| etharp_query(struct netif *netif, struct ip_addr *ipaddr, struct pbuf *q) |
| { |
| struct eth_addr * srcaddr = (struct eth_addr *)netif->hwaddr; |
| err_t result = ERR_MEM; |
| s8_t i; /* ARP entry index */ |
| |
| /* non-unicast address? */ |
| if (ip_addr_isbroadcast(ipaddr, netif) || |
| ip_addr_ismulticast(ipaddr) || |
| ip_addr_isany(ipaddr)) { |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: will not add non-unicast IP address to ARP cache\n")); |
| return ERR_ARG; |
| } |
| |
| /* find entry in ARP cache, ask to create entry if queueing packet */ |
| #if LWIP_NETIF_HWADDRHINT |
| i = find_entry(ipaddr, ETHARP_TRY_HARD, netif); |
| #else /* LWIP_NETIF_HWADDRHINT */ |
| i = find_entry(ipaddr, ETHARP_TRY_HARD); |
| #endif /* LWIP_NETIF_HWADDRHINT */ |
| |
| /* could not find or create entry? */ |
| if (i < 0) { |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: could not create ARP entry\n")); |
| if (q) { |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: packet dropped\n")); |
| ETHARP_STATS_INC(etharp.memerr); |
| } |
| return (err_t)i; |
| } |
| |
| /* mark a fresh entry as pending (we just sent a request) */ |
| if (arp_table[i].state == ETHARP_STATE_EMPTY) { |
| arp_table[i].state = ETHARP_STATE_PENDING; |
| } |
| |
| /* { i is either a STABLE or (new or existing) PENDING entry } */ |
| LWIP_ASSERT("arp_table[i].state == PENDING or STABLE", |
| ((arp_table[i].state == ETHARP_STATE_PENDING) || |
| (arp_table[i].state == ETHARP_STATE_STABLE))); |
| |
| /* do we have a pending entry? or an implicit query request? */ |
| if ((arp_table[i].state == ETHARP_STATE_PENDING) || (q == NULL)) { |
| /* try to resolve it; send out ARP request */ |
| result = etharp_request(netif, ipaddr); |
| if (result != ERR_OK) { |
| /* ARP request couldn't be sent */ |
| /* We don't re-send arp request in etharp_tmr, but we still queue packets, |
| since this failure could be temporary, and the next packet calling |
| etharp_query again could lead to sending the queued packets. */ |
| } |
| } |
| |
| /* packet given? */ |
| if (q != NULL) { |
| /* stable entry? */ |
| if (arp_table[i].state == ETHARP_STATE_STABLE) { |
| /* we have a valid IP->Ethernet address mapping */ |
| /* send the packet */ |
| result = etharp_send_ip(netif, q, srcaddr, &(arp_table[i].ethaddr)); |
| /* pending entry? (either just created or already pending */ |
| } else if (arp_table[i].state == ETHARP_STATE_PENDING) { |
| #if ARP_QUEUEING /* queue the given q packet */ |
| struct pbuf *p; |
| int copy_needed = 0; |
| /* IF q includes a PBUF_REF, PBUF_POOL or PBUF_RAM, we have no choice but |
| * to copy the whole queue into a new PBUF_RAM (see bug #11400) |
| * PBUF_ROMs can be left as they are, since ROM must not get changed. */ |
| p = q; |
| while (p) { |
| LWIP_ASSERT("no packet queues allowed!", (p->len != p->tot_len) || (p->next == 0)); |
| if(p->type != PBUF_ROM) { |
| copy_needed = 1; |
| break; |
| } |
| p = p->next; |
| } |
| if(copy_needed) { |
| /* copy the whole packet into new pbufs */ |
| p = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM); |
| if(p != NULL) { |
| if (pbuf_copy(p, q) != ERR_OK) { |
| pbuf_free(p); |
| p = NULL; |
| } |
| } |
| } else { |
| /* referencing the old pbuf is enough */ |
| p = q; |
| pbuf_ref(p); |
| } |
| /* packet could be taken over? */ |
| if (p != NULL) { |
| /* queue packet ... */ |
| struct etharp_q_entry *new_entry; |
| /* allocate a new arp queue entry */ |
| new_entry = memp_malloc(MEMP_ARP_QUEUE); |
| if (new_entry != NULL) { |
| new_entry->next = 0; |
| new_entry->p = p; |
| if(arp_table[i].q != NULL) { |
| /* queue was already existent, append the new entry to the end */ |
| struct etharp_q_entry *r; |
| r = arp_table[i].q; |
| while (r->next != NULL) { |
| r = r->next; |
| } |
| r->next = new_entry; |
| } else { |
| /* queue did not exist, first item in queue */ |
| arp_table[i].q = new_entry; |
| } |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: queued packet %p on ARP entry %"S16_F"\n", (void *)q, (s16_t)i)); |
| result = ERR_OK; |
| } else { |
| /* the pool MEMP_ARP_QUEUE is empty */ |
| pbuf_free(p); |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: could not queue a copy of PBUF_REF packet %p (out of memory)\n", (void *)q)); |
| /* { result == ERR_MEM } through initialization */ |
| } |
| } else { |
| ETHARP_STATS_INC(etharp.memerr); |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: could not queue a copy of PBUF_REF packet %p (out of memory)\n", (void *)q)); |
| /* { result == ERR_MEM } through initialization */ |
| } |
| #else /* ARP_QUEUEING == 0 */ |
| /* q && state == PENDING && ARP_QUEUEING == 0 => result = ERR_MEM */ |
| /* { result == ERR_MEM } through initialization */ |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: Ethernet destination address unknown, queueing disabled, packet %p dropped\n", (void *)q)); |
| #endif |
| } |
| } |
| return result; |
| } |
| |
| /** |
| * Send a raw ARP packet (opcode and all addresses can be modified) |
| * |
| * @param netif the lwip network interface on which to send the ARP packet |
| * @param ethsrc_addr the source MAC address for the ethernet header |
| * @param ethdst_addr the destination MAC address for the ethernet header |
| * @param hwsrc_addr the source MAC address for the ARP protocol header |
| * @param ipsrc_addr the source IP address for the ARP protocol header |
| * @param hwdst_addr the destination MAC address for the ARP protocol header |
| * @param ipdst_addr the destination IP address for the ARP protocol header |
| * @param opcode the type of the ARP packet |
| * @return ERR_OK if the ARP packet has been sent |
| * ERR_MEM if the ARP packet couldn't be allocated |
| * any other err_t on failure |
| */ |
| #if !LWIP_AUTOIP |
| static |
| #endif /* LWIP_AUTOIP */ |
| err_t |
| etharp_raw(struct netif *netif, const struct eth_addr *ethsrc_addr, |
| const struct eth_addr *ethdst_addr, |
| const struct eth_addr *hwsrc_addr, const struct ip_addr *ipsrc_addr, |
| const struct eth_addr *hwdst_addr, const struct ip_addr *ipdst_addr, |
| const u16_t opcode) |
| { |
| struct pbuf *p; |
| err_t result = ERR_OK; |
| u8_t k; /* ARP entry index */ |
| struct eth_hdr *ethhdr; |
| struct etharp_hdr *hdr; |
| #if LWIP_AUTOIP |
| const u8_t * ethdst_hwaddr; |
| #endif /* LWIP_AUTOIP */ |
| |
| /* allocate a pbuf for the outgoing ARP request packet */ |
| p = pbuf_alloc(PBUF_RAW, SIZEOF_ETHARP_PACKET, PBUF_RAM); |
| /* could allocate a pbuf for an ARP request? */ |
| if (p == NULL) { |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, |
| ("etharp_raw: could not allocate pbuf for ARP request.\n")); |
| ETHARP_STATS_INC(etharp.memerr); |
| return ERR_MEM; |
| } |
| LWIP_ASSERT("check that first pbuf can hold struct etharp_hdr", |
| (p->len >= SIZEOF_ETHARP_PACKET)); |
| |
| ethhdr = p->payload; |
| hdr = (struct etharp_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR); |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_raw: sending raw ARP packet.\n")); |
| hdr->opcode = htons(opcode); |
| |
| LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!", |
| (netif->hwaddr_len == ETHARP_HWADDR_LEN)); |
| k = ETHARP_HWADDR_LEN; |
| #if LWIP_AUTOIP |
| /* If we are using Link-Local, ARP packets must be broadcast on the |
| * link layer. (See RFC3927 Section 2.5) */ |
| ethdst_hwaddr = ((netif->autoip != NULL) && (netif->autoip->state != AUTOIP_STATE_OFF)) ? (u8_t*)(ethbroadcast.addr) : ethdst_addr->addr; |
| #endif /* LWIP_AUTOIP */ |
| /* Write MAC-Addresses (combined loop for both headers) */ |
| while(k > 0) { |
| k--; |
| /* Write the ARP MAC-Addresses */ |
| hdr->shwaddr.addr[k] = hwsrc_addr->addr[k]; |
| hdr->dhwaddr.addr[k] = hwdst_addr->addr[k]; |
| /* Write the Ethernet MAC-Addresses */ |
| #if LWIP_AUTOIP |
| ethhdr->dest.addr[k] = ethdst_hwaddr[k]; |
| #else /* LWIP_AUTOIP */ |
| ethhdr->dest.addr[k] = ethdst_addr->addr[k]; |
| #endif /* LWIP_AUTOIP */ |
| ethhdr->src.addr[k] = ethsrc_addr->addr[k]; |
| } |
| hdr->sipaddr = *(struct ip_addr2 *)ipsrc_addr; |
| hdr->dipaddr = *(struct ip_addr2 *)ipdst_addr; |
| |
| hdr->hwtype = htons(HWTYPE_ETHERNET); |
| hdr->proto = htons(ETHTYPE_IP); |
| /* set hwlen and protolen together */ |
| hdr->_hwlen_protolen = htons((ETHARP_HWADDR_LEN << 8) | sizeof(struct ip_addr)); |
| |
| ethhdr->type = htons(ETHTYPE_ARP); |
| /* send ARP query */ |
| result = netif->linkoutput(netif, p); |
| ETHARP_STATS_INC(etharp.xmit); |
| /* free ARP query packet */ |
| pbuf_free(p); |
| p = NULL; |
| /* could not allocate pbuf for ARP request */ |
| |
| return result; |
| } |
| |
| /** |
| * Send an ARP request packet asking for ipaddr. |
| * |
| * @param netif the lwip network interface on which to send the request |
| * @param ipaddr the IP address for which to ask |
| * @return ERR_OK if the request has been sent |
| * ERR_MEM if the ARP packet couldn't be allocated |
| * any other err_t on failure |
| */ |
| err_t |
| etharp_request(struct netif *netif, struct ip_addr *ipaddr) |
| { |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_request: sending ARP request.\n")); |
| return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, ðbroadcast, |
| (struct eth_addr *)netif->hwaddr, &netif->ip_addr, ðzero, |
| ipaddr, ARP_REQUEST); |
| } |
| |
| /** |
| * Process received ethernet frames. Using this function instead of directly |
| * calling ip_input and passing ARP frames through etharp in ethernetif_input, |
| * the ARP cache is protected from concurrent access. |
| * |
| * @param p the recevied packet, p->payload pointing to the ethernet header |
| * @param netif the network interface on which the packet was received |
| */ |
| err_t |
| ethernet_input(struct pbuf *p, struct netif *netif) |
| { |
| struct eth_hdr* ethhdr; |
| u16_t type; |
| |
| /* points to packet payload, which starts with an Ethernet header */ |
| ethhdr = p->payload; |
| LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, |
| ("ethernet_input: dest:%02x:%02x:%02x:%02x:%02x:%02x, src:%02x:%02x:%02x:%02x:%02x:%02x, type:%2hx\n", |
| (unsigned)ethhdr->dest.addr[0], (unsigned)ethhdr->dest.addr[1], (unsigned)ethhdr->dest.addr[2], |
| (unsigned)ethhdr->dest.addr[3], (unsigned)ethhdr->dest.addr[4], (unsigned)ethhdr->dest.addr[5], |
| (unsigned)ethhdr->src.addr[0], (unsigned)ethhdr->src.addr[1], (unsigned)ethhdr->src.addr[2], |
| (unsigned)ethhdr->src.addr[3], (unsigned)ethhdr->src.addr[4], (unsigned)ethhdr->src.addr[5], |
| (unsigned)htons(ethhdr->type))); |
| |
| type = htons(ethhdr->type); |
| #if ETHARP_SUPPORT_VLAN |
| if (type == ETHTYPE_VLAN) { |
| struct eth_vlan_hdr *vlan = (struct eth_vlan_hdr*)(((char*)ethhdr) + SIZEOF_ETH_HDR); |
| #ifdef ETHARP_VLAN_CHECK /* if not, allow all VLANs */ |
| if (VLAN_ID(vlan) != ETHARP_VLAN_CHECK) { |
| /* silently ignore this packet: not for our VLAN */ |
| pbuf_free(p); |
| return ERR_OK; |
| } |
| #endif /* ETHARP_VLAN_CHECK */ |
| type = htons(vlan->tpid); |
| } |
| #endif /* ETHARP_SUPPORT_VLAN */ |
| |
| switch (type) { |
| /* IP packet? */ |
| case ETHTYPE_IP: |
| #if ETHARP_TRUST_IP_MAC |
| /* update ARP table */ |
| etharp_ip_input(netif, p); |
| #endif /* ETHARP_TRUST_IP_MAC */ |
| /* skip Ethernet header */ |
| if(pbuf_header(p, -(s16_t)SIZEOF_ETH_HDR)) { |
| LWIP_ASSERT("Can't move over header in packet", 0); |
| pbuf_free(p); |
| p = NULL; |
| } else { |
| /* pass to IP layer */ |
| ip_input(p, netif); |
| } |
| break; |
| |
| case ETHTYPE_ARP: |
| /* pass p to ARP module */ |
| etharp_arp_input(netif, (struct eth_addr*)(netif->hwaddr), p); |
| break; |
| |
| #if PPPOE_SUPPORT |
| case ETHTYPE_PPPOEDISC: /* PPP Over Ethernet Discovery Stage */ |
| pppoe_disc_input(netif, p); |
| break; |
| |
| case ETHTYPE_PPPOE: /* PPP Over Ethernet Session Stage */ |
| pppoe_data_input(netif, p); |
| break; |
| #endif /* PPPOE_SUPPORT */ |
| |
| default: |
| ETHARP_STATS_INC(etharp.proterr); |
| ETHARP_STATS_INC(etharp.drop); |
| pbuf_free(p); |
| p = NULL; |
| break; |
| } |
| |
| /* This means the pbuf is freed or consumed, |
| so the caller doesn't have to free it again */ |
| return ERR_OK; |
| } |
| #endif /* LWIP_ARP */ |