lwip_ethernet.c

00001 /**
00002  * @file
00003  * Ethernet common functions
00004  *
00005  * @defgroup ethernet Ethernet
00006  * @ingroup callbackstyle_api
00007  */
00008 
00009 /*
00010  * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
00011  * Copyright (c) 2003-2004 Leon Woestenberg <leon.woestenberg@axon.tv>
00012  * Copyright (c) 2003-2004 Axon Digital Design B.V., The Netherlands.
00013  * All rights reserved.
00014  *
00015  * Redistribution and use in source and binary forms, with or without modification,
00016  * are permitted provided that the following conditions are met:
00017  *
00018  * 1. Redistributions of source code must retain the above copyright notice,
00019  *    this list of conditions and the following disclaimer.
00020  * 2. Redistributions in binary form must reproduce the above copyright notice,
00021  *    this list of conditions and the following disclaimer in the documentation
00022  *    and/or other materials provided with the distribution.
00023  * 3. The name of the author may not be used to endorse or promote products
00024  *    derived from this software without specific prior written permission.
00025  *
00026  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
00027  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
00028  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
00029  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00030  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
00031  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00032  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00033  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
00034  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
00035  * OF SUCH DAMAGE.
00036  *
00037  * This file is part of the lwIP TCP/IP stack.
00038  *
00039  */
00040 
00041 #include "lwip/opt.h"
00042 
00043 #if LWIP_ARP || LWIP_ETHERNET
00044 
00045 #include "netif/ethernet.h"
00046 #include "lwip/def.h"
00047 #include "lwip/stats.h"
00048 #include "lwip/etharp.h"
00049 #include "lwip/ip.h"
00050 #include "lwip/snmp.h"
00051 
00052 #include <string.h>
00053 
00054 #ifdef LWIP_HOOK_FILENAME
00055 #include LWIP_HOOK_FILENAME
00056 #endif
00057 
00058 const struct eth_addr ethbroadcast = {{0xff, 0xff, 0xff, 0xff, 0xff, 0xff}};
00059 const struct eth_addr ethzero = {{0, 0, 0, 0, 0, 0}};
00060 
00061 /**
00062  * @ingroup lwip_nosys
00063  * Process received ethernet frames. Using this function instead of directly
00064  * calling ip_input and passing ARP frames through etharp in ethernetif_input,
00065  * the ARP cache is protected from concurrent access.\n
00066  * Don't call directly, pass to netif_add() and call netif->input().
00067  *
00068  * @param p the received packet, p->payload pointing to the ethernet header
00069  * @param netif the network interface on which the packet was received
00070  *
00071  * @see LWIP_HOOK_UNKNOWN_ETH_PROTOCOL
00072  * @see ETHARP_SUPPORT_VLAN
00073  * @see LWIP_HOOK_VLAN_CHECK
00074  */
00075 err_t
00076 ethernet_input(struct pbuf *p, struct netif *netif)
00077 {
00078   struct eth_hdr *ethhdr;
00079   u16_t type;
00080 #if LWIP_ARP || ETHARP_SUPPORT_VLAN || LWIP_IPV6
00081   u16_t next_hdr_offset = SIZEOF_ETH_HDR;
00082 #endif /* LWIP_ARP || ETHARP_SUPPORT_VLAN */
00083 
00084   LWIP_ASSERT_CORE_LOCKED();
00085 
00086   if (p->len <= SIZEOF_ETH_HDR) {
00087     /* a packet with only an ethernet header (or less) is not valid for us */
00088     ETHARP_STATS_INC(etharp.proterr);
00089     ETHARP_STATS_INC(etharp.drop);
00090     MIB2_STATS_NETIF_INC(netif, ifinerrors);
00091     goto free_and_return;
00092   }
00093 
00094   if (p->if_idx == NETIF_NO_INDEX) {
00095     p->if_idx = netif_get_index(netif);
00096   }
00097 
00098   /* points to packet payload, which starts with an Ethernet header */
00099   ethhdr = (struct eth_hdr *)p->payload;
00100   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE,
00101               ("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",
00102                (unsigned char)ethhdr->dest.addr[0], (unsigned char)ethhdr->dest.addr[1], (unsigned char)ethhdr->dest.addr[2],
00103                (unsigned char)ethhdr->dest.addr[3], (unsigned char)ethhdr->dest.addr[4], (unsigned char)ethhdr->dest.addr[5],
00104                (unsigned char)ethhdr->src.addr[0],  (unsigned char)ethhdr->src.addr[1],  (unsigned char)ethhdr->src.addr[2],
00105                (unsigned char)ethhdr->src.addr[3],  (unsigned char)ethhdr->src.addr[4],  (unsigned char)ethhdr->src.addr[5],
00106                lwip_htons(ethhdr->type)));
00107 
00108   type = ethhdr->type;
00109 #if ETHARP_SUPPORT_VLAN
00110   if (type == PP_HTONS(ETHTYPE_VLAN)) {
00111     struct eth_vlan_hdr *vlan = (struct eth_vlan_hdr *)(((char *)ethhdr) + SIZEOF_ETH_HDR);
00112     next_hdr_offset = SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR;
00113     if (p->len <= SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR) {
00114       /* a packet with only an ethernet/vlan header (or less) is not valid for us */
00115       ETHARP_STATS_INC(etharp.proterr);
00116       ETHARP_STATS_INC(etharp.drop);
00117       MIB2_STATS_NETIF_INC(netif, ifinerrors);
00118       goto free_and_return;
00119     }
00120 #if defined(LWIP_HOOK_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK_FN) /* if not, allow all VLANs */
00121 #ifdef LWIP_HOOK_VLAN_CHECK
00122     if (!LWIP_HOOK_VLAN_CHECK(netif, ethhdr, vlan)) {
00123 #elif defined(ETHARP_VLAN_CHECK_FN)
00124     if (!ETHARP_VLAN_CHECK_FN(ethhdr, vlan)) {
00125 #elif defined(ETHARP_VLAN_CHECK)
00126     if (VLAN_ID(vlan) != ETHARP_VLAN_CHECK) {
00127 #endif
00128       /* silently ignore this packet: not for our VLAN */
00129       pbuf_free(p);
00130       return ERR_OK;
00131     }
00132 #endif /* defined(LWIP_HOOK_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK_FN) */
00133     type = vlan->tpid;
00134   }
00135 #endif /* ETHARP_SUPPORT_VLAN */
00136 
00137 #if LWIP_ARP_FILTER_NETIF
00138   netif = LWIP_ARP_FILTER_NETIF_FN(p, netif, lwip_htons(type));
00139 #endif /* LWIP_ARP_FILTER_NETIF*/
00140 
00141   if (ethhdr->dest.addr[0] & 1) {
00142     /* this might be a multicast or broadcast packet */
00143     if (ethhdr->dest.addr[0] == LL_IP4_MULTICAST_ADDR_0) {
00144 #if LWIP_IPV4
00145       if ((ethhdr->dest.addr[1] == LL_IP4_MULTICAST_ADDR_1) &&
00146           (ethhdr->dest.addr[2] == LL_IP4_MULTICAST_ADDR_2)) {
00147         /* mark the pbuf as link-layer multicast */
00148         p->flags |= PBUF_FLAG_LLMCAST;
00149       }
00150 #endif /* LWIP_IPV4 */
00151     }
00152 #if LWIP_IPV6
00153     else if ((ethhdr->dest.addr[0] == LL_IP6_MULTICAST_ADDR_0) &&
00154              (ethhdr->dest.addr[1] == LL_IP6_MULTICAST_ADDR_1)) {
00155       /* mark the pbuf as link-layer multicast */
00156       p->flags |= PBUF_FLAG_LLMCAST;
00157     }
00158 #endif /* LWIP_IPV6 */
00159     else if (eth_addr_cmp(&ethhdr->dest, &ethbroadcast)) {
00160       /* mark the pbuf as link-layer broadcast */
00161       p->flags |= PBUF_FLAG_LLBCAST;
00162     }
00163   }
00164 
00165   switch (type) {
00166 #if LWIP_IPV4 && LWIP_ARP
00167     /* IP packet? */
00168     case PP_HTONS(ETHTYPE_IP):
00169       if (!(netif->flags & NETIF_FLAG_ETHARP)) {
00170         goto free_and_return;
00171       }
00172       /* skip Ethernet header (min. size checked above) */
00173       if (pbuf_remove_header(p, next_hdr_offset)) {
00174         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
00175                     ("ethernet_input: IPv4 packet dropped, too short (%"U16_F"/%"U16_F")\n",
00176                      p->tot_len, next_hdr_offset));
00177         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("Can't move over header in packet"));
00178         goto free_and_return;
00179       } else {
00180         /* pass to IP layer */
00181         ip4_input(p, netif);
00182       }
00183       break;
00184 
00185     case PP_HTONS(ETHTYPE_ARP):
00186       if (!(netif->flags & NETIF_FLAG_ETHARP)) {
00187         goto free_and_return;
00188       }
00189       /* skip Ethernet header (min. size checked above) */
00190       if (pbuf_remove_header(p, next_hdr_offset)) {
00191         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
00192                     ("ethernet_input: ARP response packet dropped, too short (%"U16_F"/%"U16_F")\n",
00193                      p->tot_len, next_hdr_offset));
00194         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("Can't move over header in packet"));
00195         ETHARP_STATS_INC(etharp.lenerr);
00196         ETHARP_STATS_INC(etharp.drop);
00197         goto free_and_return;
00198       } else {
00199         /* pass p to ARP module */
00200         etharp_input(p, netif);
00201       }
00202       break;
00203 #endif /* LWIP_IPV4 && LWIP_ARP */
00204 #if PPPOE_SUPPORT
00205     case PP_HTONS(ETHTYPE_PPPOEDISC): /* PPP Over Ethernet Discovery Stage */
00206       pppoe_disc_input(netif, p);
00207       break;
00208 
00209     case PP_HTONS(ETHTYPE_PPPOE): /* PPP Over Ethernet Session Stage */
00210       pppoe_data_input(netif, p);
00211       break;
00212 #endif /* PPPOE_SUPPORT */
00213 
00214 #if LWIP_IPV6
00215     case PP_HTONS(ETHTYPE_IPV6): /* IPv6 */
00216       /* skip Ethernet header */
00217       if ((p->len < next_hdr_offset) || pbuf_remove_header(p, next_hdr_offset)) {
00218         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
00219                     ("ethernet_input: IPv6 packet dropped, too short (%"U16_F"/%"U16_F")\n",
00220                      p->tot_len, next_hdr_offset));
00221         goto free_and_return;
00222       } else {
00223         /* pass to IPv6 layer */
00224         ip6_input(p, netif);
00225       }
00226       break;
00227 #endif /* LWIP_IPV6 */
00228 
00229     default:
00230 #ifdef LWIP_HOOK_UNKNOWN_ETH_PROTOCOL
00231       if (LWIP_HOOK_UNKNOWN_ETH_PROTOCOL(p, netif) == ERR_OK) {
00232         break;
00233       }
00234 #endif
00235       ETHARP_STATS_INC(etharp.proterr);
00236       ETHARP_STATS_INC(etharp.drop);
00237       MIB2_STATS_NETIF_INC(netif, ifinunknownprotos);
00238       goto free_and_return;
00239   }
00240 
00241   /* This means the pbuf is freed or consumed,
00242      so the caller doesn't have to free it again */
00243   return ERR_OK;
00244 
00245 free_and_return:
00246   pbuf_free(p);
00247   return ERR_OK;
00248 }
00249 
00250 /**
00251  * @ingroup ethernet
00252  * Send an ethernet packet on the network using netif->linkoutput().
00253  * The ethernet header is filled in before sending.
00254  *
00255  * @see LWIP_HOOK_VLAN_SET
00256  *
00257  * @param netif the lwIP network interface on which to send the packet
00258  * @param p the packet to send. pbuf layer must be @ref PBUF_LINK.
00259  * @param src the source MAC address to be copied into the ethernet header
00260  * @param dst the destination MAC address to be copied into the ethernet header
00261  * @param eth_type ethernet type (@ref lwip_ieee_eth_type)
00262  * @return ERR_OK if the packet was sent, any other err_t on failure
00263  */
00264 err_t
00265 ethernet_output(struct netif * netif, struct pbuf * p,
00266                 const struct eth_addr * src, const struct eth_addr * dst,
00267                 u16_t eth_type) {
00268   struct eth_hdr *ethhdr;
00269   u16_t eth_type_be = lwip_htons(eth_type);
00270 
00271 #if ETHARP_SUPPORT_VLAN && defined(LWIP_HOOK_VLAN_SET)
00272   s32_t vlan_prio_vid = LWIP_HOOK_VLAN_SET(netif, p, src, dst, eth_type);
00273   if (vlan_prio_vid >= 0) {
00274     struct eth_vlan_hdr *vlanhdr;
00275 
00276     LWIP_ASSERT("prio_vid must be <= 0xFFFF", vlan_prio_vid <= 0xFFFF);
00277 
00278     if (pbuf_add_header(p, SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR) != 0) {
00279       goto pbuf_header_failed;
00280     }
00281     vlanhdr = (struct eth_vlan_hdr *)(((u8_t *)p->payload) + SIZEOF_ETH_HDR);
00282     vlanhdr->tpid     = eth_type_be;
00283     vlanhdr->prio_vid = lwip_htons((u16_t)vlan_prio_vid);
00284 
00285     eth_type_be = PP_HTONS(ETHTYPE_VLAN);
00286   } else
00287 #endif /* ETHARP_SUPPORT_VLAN && defined(LWIP_HOOK_VLAN_SET) */
00288   {
00289     if (pbuf_add_header(p, SIZEOF_ETH_HDR) != 0) {
00290       goto pbuf_header_failed;
00291     }
00292   }
00293 
00294   LWIP_ASSERT_CORE_LOCKED();
00295 
00296   ethhdr = (struct eth_hdr *)p->payload;
00297   ethhdr->type = eth_type_be;
00298   SMEMCPY(&ethhdr->dest, dst, ETH_HWADDR_LEN);
00299   SMEMCPY(&ethhdr->src,  src, ETH_HWADDR_LEN);
00300 
00301   LWIP_ASSERT("netif->hwaddr_len must be 6 for ethernet_output!",
00302               (netif->hwaddr_len == ETH_HWADDR_LEN));
00303   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE,
00304               ("ethernet_output: sending packet %p\n", (void *)p));
00305 
00306   /* send the packet */
00307   return netif->linkoutput(netif, p);
00308 
00309 pbuf_header_failed:
00310   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
00311               ("ethernet_output: could not allocate room for header.\n"));
00312   LINK_STATS_INC(link.lenerr);
00313   return ERR_BUF;
00314 }
00315 
00316 #endif /* LWIP_ARP || LWIP_ETHERNET */