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/lwip_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 #include "netif/ppp/ppp_opts.h"
00055 #if PPPOE_SUPPORT
00056 #include "netif/ppp/pppoe.h"
00057 #endif /* PPPOE_SUPPORT */
00058 
00059 const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};
00060 const struct eth_addr ethzero = {{0,0,0,0,0,0}};
00061 
00062 /**
00063  * @ingroup lwip_nosys
00064  * Process received ethernet frames. Using this function instead of directly
00065  * calling ip_input and passing ARP frames through etharp in ethernetif_input,
00066  * the ARP cache is protected from concurrent access.\n
00067  * Don't call directly, pass to netif_add() and call netif->input().
00068  *
00069  * @param p the received packet, p->payload pointing to the ethernet header
00070  * @param netif the network interface on which the packet was received
00071  * 
00072  * @see LWIP_HOOK_UNKNOWN_ETH_PROTOCOL
00073  * @see ETHARP_SUPPORT_VLAN
00074  * @see LWIP_HOOK_VLAN_CHECK
00075  */
00076 err_t
00077 ethernet_input(struct pbuf *p, struct netif *netif)
00078 {
00079   struct eth_hdr* ethhdr;
00080   u16_t type;
00081 #if LWIP_ARP || ETHARP_SUPPORT_VLAN || LWIP_IPV6
00082   s16_t ip_hdr_offset = SIZEOF_ETH_HDR;
00083 #endif /* LWIP_ARP || ETHARP_SUPPORT_VLAN */
00084 
00085   if (p->len <= SIZEOF_ETH_HDR) {
00086     /* a packet with only an ethernet header (or less) is not valid for us */
00087     ETHARP_STATS_INC(etharp.proterr);
00088     ETHARP_STATS_INC(etharp.drop);
00089     MIB2_STATS_NETIF_INC(netif, ifinerrors);
00090     goto free_and_return;
00091   }
00092 
00093   /* points to packet payload, which starts with an Ethernet header */
00094   ethhdr = (struct eth_hdr *)p->payload;
00095   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE,
00096     ("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",
00097      (unsigned)ethhdr->dest.addr[0], (unsigned)ethhdr->dest.addr[1], (unsigned)ethhdr->dest.addr[2],
00098      (unsigned)ethhdr->dest.addr[3], (unsigned)ethhdr->dest.addr[4], (unsigned)ethhdr->dest.addr[5],
00099      (unsigned)ethhdr->src.addr[0],  (unsigned)ethhdr->src.addr[1],  (unsigned)ethhdr->src.addr[2],
00100      (unsigned)ethhdr->src.addr[3],  (unsigned)ethhdr->src.addr[4],  (unsigned)ethhdr->src.addr[5],
00101      lwip_htons(ethhdr->type)));
00102 
00103   type = ethhdr->type;
00104 #if ETHARP_SUPPORT_VLAN
00105   if (type == PP_HTONS(ETHTYPE_VLAN)) {
00106     struct eth_vlan_hdr *vlan = (struct eth_vlan_hdr*)(((char*)ethhdr) + SIZEOF_ETH_HDR);
00107     if (p->len <= SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR) {
00108       /* a packet with only an ethernet/vlan header (or less) is not valid for us */
00109       ETHARP_STATS_INC(etharp.proterr);
00110       ETHARP_STATS_INC(etharp.drop);
00111       MIB2_STATS_NETIF_INC(netif, ifinerrors);
00112       goto free_and_return;
00113     }
00114 #if defined(LWIP_HOOK_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK_FN) /* if not, allow all VLANs */
00115 #ifdef LWIP_HOOK_VLAN_CHECK
00116     if (!LWIP_HOOK_VLAN_CHECK(netif, ethhdr, vlan)) {
00117 #elif defined(ETHARP_VLAN_CHECK_FN)
00118     if (!ETHARP_VLAN_CHECK_FN(ethhdr, vlan)) {
00119 #elif defined(ETHARP_VLAN_CHECK)
00120     if (VLAN_ID(vlan) != ETHARP_VLAN_CHECK) {
00121 #endif
00122       /* silently ignore this packet: not for our VLAN */
00123       pbuf_free(p);
00124       return ERR_OK;
00125     }
00126 #endif /* defined(LWIP_HOOK_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK_FN) */
00127     type = vlan->tpid;
00128     ip_hdr_offset = SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR;
00129   }
00130 #endif /* ETHARP_SUPPORT_VLAN */
00131 
00132 #if LWIP_ARP_FILTER_NETIF
00133   netif = LWIP_ARP_FILTER_NETIF_FN(p, netif, lwip_htons(type));
00134 #endif /* LWIP_ARP_FILTER_NETIF*/
00135 
00136   if (ethhdr->dest.addr[0] & 1) {
00137     /* this might be a multicast or broadcast packet */
00138     if (ethhdr->dest.addr[0] == LL_IP4_MULTICAST_ADDR_0) {
00139 #if LWIP_IPV4
00140       if ((ethhdr->dest.addr[1] == LL_IP4_MULTICAST_ADDR_1) &&
00141           (ethhdr->dest.addr[2] == LL_IP4_MULTICAST_ADDR_2)) {
00142         /* mark the pbuf as link-layer multicast */
00143         p->flags |= PBUF_FLAG_LLMCAST;
00144       }
00145 #endif /* LWIP_IPV4 */
00146     }
00147 #if LWIP_IPV6
00148     else if ((ethhdr->dest.addr[0] == LL_IP6_MULTICAST_ADDR_0) &&
00149              (ethhdr->dest.addr[1] == LL_IP6_MULTICAST_ADDR_1)) {
00150         /* mark the pbuf as link-layer multicast */
00151         p->flags |= PBUF_FLAG_LLMCAST;
00152     }
00153 #endif /* LWIP_IPV6 */
00154     else if (eth_addr_cmp(&ethhdr->dest, &ethbroadcast)) {
00155       /* mark the pbuf as link-layer broadcast */
00156       p->flags |= PBUF_FLAG_LLBCAST;
00157     }
00158   }
00159 
00160   switch (type) {
00161 #if LWIP_IPV4 && LWIP_ARP
00162     /* IP packet? */
00163     case PP_HTONS(ETHTYPE_IP):
00164       if (!(netif->flags & NETIF_FLAG_ETHARP)) {
00165         goto free_and_return;
00166       }
00167       /* skip Ethernet header */
00168       if ((p->len < ip_hdr_offset) || pbuf_header(p, (s16_t)-ip_hdr_offset)) {
00169         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
00170           ("ethernet_input: IPv4 packet dropped, too short (%"S16_F"/%"S16_F")\n",
00171           p->tot_len, ip_hdr_offset));
00172         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("Can't move over header in packet"));
00173         goto free_and_return;
00174       } else {
00175         /* pass to IP layer */
00176         ip4_input(p, netif);
00177       }
00178       break;
00179 
00180     case PP_HTONS(ETHTYPE_ARP):
00181       if (!(netif->flags & NETIF_FLAG_ETHARP)) {
00182         goto free_and_return;
00183       }
00184       /* skip Ethernet header */
00185       if ((p->len < ip_hdr_offset) || pbuf_header(p, (s16_t)-ip_hdr_offset)) {
00186         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
00187           ("ethernet_input: ARP response packet dropped, too short (%"S16_F"/%"S16_F")\n",
00188           p->tot_len, ip_hdr_offset));
00189         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("Can't move over header in packet"));
00190         ETHARP_STATS_INC(etharp.lenerr);
00191         ETHARP_STATS_INC(etharp.drop);
00192         goto free_and_return;
00193       } else {
00194         /* pass p to ARP module */
00195         etharp_input(p, netif);
00196       }
00197       break;
00198 #endif /* LWIP_IPV4 && LWIP_ARP */
00199 #if PPPOE_SUPPORT
00200     case PP_HTONS(ETHTYPE_PPPOEDISC): /* PPP Over Ethernet Discovery Stage */
00201       pppoe_disc_input(netif, p);
00202       break;
00203 
00204     case PP_HTONS(ETHTYPE_PPPOE): /* PPP Over Ethernet Session Stage */
00205       pppoe_data_input(netif, p);
00206       break;
00207 #endif /* PPPOE_SUPPORT */
00208 
00209 #if LWIP_IPV6
00210     case PP_HTONS(ETHTYPE_IPV6): /* IPv6 */
00211       /* skip Ethernet header */
00212       if ((p->len < ip_hdr_offset) || pbuf_header(p, (s16_t)-ip_hdr_offset)) {
00213         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
00214           ("ethernet_input: IPv6 packet dropped, too short (%"S16_F"/%"S16_F")\n",
00215           p->tot_len, ip_hdr_offset));
00216         goto free_and_return;
00217       } else {
00218         /* pass to IPv6 layer */
00219         ip6_input(p, netif);
00220       }
00221       break;
00222 #endif /* LWIP_IPV6 */
00223 
00224     default:
00225 #ifdef LWIP_HOOK_UNKNOWN_ETH_PROTOCOL
00226       if(LWIP_HOOK_UNKNOWN_ETH_PROTOCOL(p, netif) == ERR_OK) {
00227         break;
00228       }
00229 #endif
00230       ETHARP_STATS_INC(etharp.proterr);
00231       ETHARP_STATS_INC(etharp.drop);
00232       MIB2_STATS_NETIF_INC(netif, ifinunknownprotos);
00233       goto free_and_return;
00234   }
00235 
00236   /* This means the pbuf is freed or consumed,
00237      so the caller doesn't have to free it again */
00238   return ERR_OK;
00239 
00240 free_and_return:
00241   pbuf_free(p);
00242   return ERR_OK;
00243 }
00244 
00245 /**
00246  * @ingroup ethernet
00247  * Send an ethernet packet on the network using netif->linkoutput().
00248  * The ethernet header is filled in before sending.
00249  *
00250  * @see LWIP_HOOK_VLAN_SET
00251  *
00252  * @param netif the lwIP network interface on which to send the packet
00253  * @param p the packet to send. pbuf layer must be @ref PBUF_LINK.
00254  * @param src the source MAC address to be copied into the ethernet header
00255  * @param dst the destination MAC address to be copied into the ethernet header
00256  * @param eth_type ethernet type (@ref eth_type)
00257  * @return ERR_OK if the packet was sent, any other err_t on failure
00258  */
00259 err_t
00260 ethernet_output(struct netif* netif, struct pbuf* p,
00261                 const struct eth_addr* src, const struct eth_addr* dst,
00262                 u16_t eth_type)
00263 {
00264   struct eth_hdr* ethhdr;
00265   u16_t eth_type_be = lwip_htons(eth_type);
00266 
00267 #if ETHARP_SUPPORT_VLAN && defined(LWIP_HOOK_VLAN_SET)
00268   s32_t vlan_prio_vid = LWIP_HOOK_VLAN_SET(netif, p, src, dst, eth_type);
00269   if (vlan_prio_vid >= 0) {
00270     struct eth_vlan_hdr* vlanhdr;
00271 
00272     LWIP_ASSERT("prio_vid must be <= 0xFFFF", vlan_prio_vid <= 0xFFFF);
00273 
00274     if (pbuf_header(p, SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR) != 0) {
00275       goto pbuf_header_failed;
00276     }
00277     vlanhdr = (struct eth_vlan_hdr*)(((u8_t*)p->payload) + SIZEOF_ETH_HDR);
00278     vlanhdr->tpid     = eth_type_be;
00279     vlanhdr->prio_vid = lwip_htons((u16_t)vlan_prio_vid);
00280 
00281     eth_type_be = PP_HTONS(ETHTYPE_VLAN);
00282   } else
00283 #endif /* ETHARP_SUPPORT_VLAN && defined(LWIP_HOOK_VLAN_SET) */
00284   {
00285     if (pbuf_header(p, SIZEOF_ETH_HDR) != 0) {
00286       goto pbuf_header_failed;
00287     }
00288   }
00289 
00290   ethhdr = (struct eth_hdr*)p->payload;
00291   ethhdr->type = eth_type_be;
00292   ETHADDR32_COPY(&ethhdr->dest, dst);
00293   ETHADDR16_COPY(&ethhdr->src,  src);
00294 
00295   LWIP_ASSERT("netif->hwaddr_len must be 6 for ethernet_output!",
00296     (netif->hwaddr_len == ETH_HWADDR_LEN));
00297   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE,
00298     ("ethernet_output: sending packet %p\n", (void *)p));
00299 
00300   /* send the packet */
00301   return netif->linkoutput(netif, p);
00302 
00303 pbuf_header_failed:
00304   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
00305     ("ethernet_output: could not allocate room for header.\n"));
00306   LINK_STATS_INC(link.lenerr);
00307   return ERR_BUF;
00308 }
00309 
00310 #endif /* LWIP_ARP || LWIP_ETHERNET */