lwip_ethernet.c

00001 /**
00002  * @file
00003  * Ethernet common functions
00004  */
00005 
00006 /*
00007  * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
00008  * Copyright (c) 2003-2004 Leon Woestenberg <leon.woestenberg@axon.tv>
00009  * Copyright (c) 2003-2004 Axon Digital Design B.V., The Netherlands.
00010  * All rights reserved.
00011  *
00012  * Redistribution and use in source and binary forms, with or without modification,
00013  * are permitted provided that the following conditions are met:
00014  *
00015  * 1. Redistributions of source code must retain the above copyright notice,
00016  *    this list of conditions and the following disclaimer.
00017  * 2. Redistributions in binary form must reproduce the above copyright notice,
00018  *    this list of conditions and the following disclaimer in the documentation
00019  *    and/or other materials provided with the distribution.
00020  * 3. The name of the author may not be used to endorse or promote products
00021  *    derived from this software without specific prior written permission.
00022  *
00023  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
00024  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
00025  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
00026  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00027  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
00028  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00029  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00030  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
00031  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
00032  * OF SUCH DAMAGE.
00033  *
00034  * This file is part of the lwIP TCP/IP stack.
00035  *
00036  */
00037 
00038 #include "lwip/opt.h"
00039 
00040 #if LWIP_ARP || LWIP_ETHERNET
00041 
00042 #include "netif/lwip_ethernet.h"
00043 #include "lwip/def.h"
00044 #include "lwip/stats.h"
00045 #include "lwip/etharp.h"
00046 #include "lwip/ip.h"
00047 #include "lwip/snmp.h"
00048 
00049 #include <string.h>
00050 
00051 #include "netif/ppp/ppp_opts.h"
00052 #if PPPOE_SUPPORT
00053 #include "netif/ppp/pppoe.h"
00054 #endif /* PPPOE_SUPPORT */
00055 
00056 const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};
00057 const struct eth_addr ethzero = {{0,0,0,0,0,0}};
00058 
00059 /**
00060  * @ingroup lwip_nosys
00061  * Process received ethernet frames. Using this function instead of directly
00062  * calling ip_input and passing ARP frames through etharp in ethernetif_input,
00063  * the ARP cache is protected from concurrent access.\n
00064  * Don't call directly, pass to netif_add() and call netif->input().
00065  *
00066  * @param p the received packet, p->payload pointing to the ethernet header
00067  * @param netif the network interface on which the packet was received
00068  */
00069 err_t
00070 ethernet_input(struct pbuf *p, struct netif *netif)
00071 {
00072   struct eth_hdr* ethhdr;
00073   u16_t type;
00074 #if LWIP_ARP || ETHARP_SUPPORT_VLAN || LWIP_IPV6
00075   s16_t ip_hdr_offset = SIZEOF_ETH_HDR;
00076 #endif /* LWIP_ARP || ETHARP_SUPPORT_VLAN */
00077 
00078   if (p->len <= SIZEOF_ETH_HDR) {
00079     /* a packet with only an ethernet header (or less) is not valid for us */
00080     ETHARP_STATS_INC(etharp.proterr);
00081     ETHARP_STATS_INC(etharp.drop);
00082     MIB2_STATS_NETIF_INC(netif, ifinerrors);
00083     goto free_and_return;
00084   }
00085 
00086   /* points to packet payload, which starts with an Ethernet header */
00087   ethhdr = (struct eth_hdr *)p->payload;
00088   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE,
00089     ("ethernet_input: dest:%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F", src:%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F", type:%"X16_F"\n",
00090      (unsigned)ethhdr->dest.addr[0], (unsigned)ethhdr->dest.addr[1], (unsigned)ethhdr->dest.addr[2],
00091      (unsigned)ethhdr->dest.addr[3], (unsigned)ethhdr->dest.addr[4], (unsigned)ethhdr->dest.addr[5],
00092      (unsigned)ethhdr->src.addr[0],  (unsigned)ethhdr->src.addr[1],  (unsigned)ethhdr->src.addr[2],
00093      (unsigned)ethhdr->src.addr[3],  (unsigned)ethhdr->src.addr[4],  (unsigned)ethhdr->src.addr[5],
00094      htons(ethhdr->type)));
00095 
00096   type = ethhdr->type;
00097 #if ETHARP_SUPPORT_VLAN
00098   if (type == PP_HTONS(ETHTYPE_VLAN)) {
00099     struct eth_vlan_hdr *vlan = (struct eth_vlan_hdr*)(((char*)ethhdr) + SIZEOF_ETH_HDR);
00100     if (p->len <= SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR) {
00101       /* a packet with only an ethernet/vlan header (or less) is not valid for us */
00102       ETHARP_STATS_INC(etharp.proterr);
00103       ETHARP_STATS_INC(etharp.drop);
00104       MIB2_STATS_NETIF_INC(netif, ifinerrors);
00105       goto free_and_return;
00106     }
00107 #if defined(LWIP_HOOK_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK_FN) /* if not, allow all VLANs */
00108 #ifdef LWIP_HOOK_VLAN_CHECK
00109     if (!LWIP_HOOK_VLAN_CHECK(netif, ethhdr, vlan)) {
00110 #elif defined(ETHARP_VLAN_CHECK_FN)
00111     if (!ETHARP_VLAN_CHECK_FN(ethhdr, vlan)) {
00112 #elif defined(ETHARP_VLAN_CHECK)
00113     if (VLAN_ID(vlan) != ETHARP_VLAN_CHECK) {
00114 #endif
00115       /* silently ignore this packet: not for our VLAN */
00116       pbuf_free(p);
00117       return ERR_OK;
00118     }
00119 #endif /* defined(LWIP_HOOK_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK_FN) */
00120     type = vlan->tpid;
00121     ip_hdr_offset = SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR;
00122   }
00123 #endif /* ETHARP_SUPPORT_VLAN */
00124 
00125 #if LWIP_ARP_FILTER_NETIF
00126   netif = LWIP_ARP_FILTER_NETIF_FN(p, netif, htons(type));
00127 #endif /* LWIP_ARP_FILTER_NETIF*/
00128 
00129   if (ethhdr->dest.addr[0] & 1) {
00130     /* this might be a multicast or broadcast packet */
00131     if (ethhdr->dest.addr[0] == LL_IP4_MULTICAST_ADDR_0) {
00132 #if LWIP_IPV4
00133       if ((ethhdr->dest.addr[1] == LL_IP4_MULTICAST_ADDR_1) &&
00134           (ethhdr->dest.addr[2] == LL_IP4_MULTICAST_ADDR_2)) {
00135         /* mark the pbuf as link-layer multicast */
00136         p->flags |= PBUF_FLAG_LLMCAST;
00137       }
00138 #endif /* LWIP_IPV4 */
00139     }
00140 #if LWIP_IPV6
00141     else if ((ethhdr->dest.addr[0] == LL_IP6_MULTICAST_ADDR_0) &&
00142                (ethhdr->dest.addr[1] == LL_IP6_MULTICAST_ADDR_1)) {
00143         /* mark the pbuf as link-layer multicast */
00144         p->flags |= PBUF_FLAG_LLMCAST;
00145     }
00146 #endif /* LWIP_IPV6 */
00147     else if (eth_addr_cmp(&ethhdr->dest, &ethbroadcast)) {
00148       /* mark the pbuf as link-layer broadcast */
00149       p->flags |= PBUF_FLAG_LLBCAST;
00150     }
00151   }
00152 
00153   switch (type) {
00154 #if LWIP_IPV4 && LWIP_ARP
00155     /* IP packet? */
00156     case PP_HTONS(ETHTYPE_IP):
00157       if (!(netif->flags & NETIF_FLAG_ETHARP)) {
00158         goto free_and_return;
00159       }
00160 #if ETHARP_TRUST_IP_MAC
00161       /* update ARP table */
00162       etharp_ip_input(netif, p);
00163 #endif /* ETHARP_TRUST_IP_MAC */
00164       /* skip Ethernet header */
00165       if ((p->len < ip_hdr_offset) || pbuf_header(p, (s16_t)-ip_hdr_offset)) {
00166         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
00167           ("ethernet_input: IPv4 packet dropped, too short (%"S16_F"/%"S16_F")\n",
00168           p->tot_len, ip_hdr_offset));
00169         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("Can't move over header in packet"));
00170         goto free_and_return;
00171       } else {
00172         /* pass to IP layer */
00173         ip4_input(p, netif);
00174       }
00175       break;
00176 
00177     case PP_HTONS(ETHTYPE_ARP):
00178       if (!(netif->flags & NETIF_FLAG_ETHARP)) {
00179         goto free_and_return;
00180       }
00181       /* pass p to ARP module */
00182       etharp_arp_input(netif, (struct eth_addr*)(netif->hwaddr), p);
00183       break;
00184 #endif /* LWIP_IPV4 && LWIP_ARP */
00185 #if PPPOE_SUPPORT
00186     case PP_HTONS(ETHTYPE_PPPOEDISC): /* PPP Over Ethernet Discovery Stage */
00187       pppoe_disc_input(netif, p);
00188       break;
00189 
00190     case PP_HTONS(ETHTYPE_PPPOE): /* PPP Over Ethernet Session Stage */
00191       pppoe_data_input(netif, p);
00192       break;
00193 #endif /* PPPOE_SUPPORT */
00194 
00195 #if LWIP_IPV6
00196     case PP_HTONS(ETHTYPE_IPV6): /* IPv6 */
00197       /* skip Ethernet header */
00198       if ((p->len < ip_hdr_offset) || pbuf_header(p, (s16_t)-ip_hdr_offset)) {
00199         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
00200           ("ethernet_input: IPv6 packet dropped, too short (%"S16_F"/%"S16_F")\n",
00201           p->tot_len, ip_hdr_offset));
00202         goto free_and_return;
00203       } else {
00204         /* pass to IPv6 layer */
00205         ip6_input(p, netif);
00206       }
00207       break;
00208 #endif /* LWIP_IPV6 */
00209 
00210     default:
00211       ETHARP_STATS_INC(etharp.proterr);
00212       ETHARP_STATS_INC(etharp.drop);
00213       MIB2_STATS_NETIF_INC(netif, ifinunknownprotos);
00214       goto free_and_return;
00215   }
00216 
00217   /* This means the pbuf is freed or consumed,
00218      so the caller doesn't have to free it again */
00219   return ERR_OK;
00220 
00221 free_and_return:
00222   pbuf_free(p);
00223   return ERR_OK;
00224 }
00225 #endif /* LWIP_ARP || LWIP_ETHERNET */