Dieter Graef
Ethernet for Nucleo and Disco board STM32F746 works with gcc and arm. IAC is untested
Dependents: STM32F746_iothub_client_sample_mqtt DISCO-F746NG_Ethernet Nucleo_F746ZG_Ethernet thethingsiO-DISCO_F746NG-mqtt ... more
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etharp.c
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00001 /** 00002 * @file 00003 * Address Resolution Protocol module for IP over Ethernet 00004 * 00005 * Functionally, ARP is divided into two parts. The first maps an IP address 00006 * to a physical address when sending a packet, and the second part answers 00007 * requests from other machines for our physical address. 00008 * 00009 * This implementation complies with RFC 826 (Ethernet ARP). It supports 00010 * Gratuitious ARP from RFC3220 (IP Mobility Support for IPv4) section 4.6 00011 * if an interface calls etharp_gratuitous(our_netif) upon address change. 00012 */ 00013 00014 /* 00015 * Copyright (c) 2001-2003 Swedish Institute of Computer Science. 00016 * Copyright (c) 2003-2004 Leon Woestenberg <leon.woestenberg@axon.tv> 00017 * Copyright (c) 2003-2004 Axon Digital Design B.V., The Netherlands. 00018 * All rights reserved. 00019 * 00020 * Redistribution and use in source and binary forms, with or without modification, 00021 * are permitted provided that the following conditions are met: 00022 * 00023 * 1. Redistributions of source code must retain the above copyright notice, 00024 * this list of conditions and the following disclaimer. 00025 * 2. Redistributions in binary form must reproduce the above copyright notice, 00026 * this list of conditions and the following disclaimer in the documentation 00027 * and/or other materials provided with the distribution. 00028 * 3. The name of the author may not be used to endorse or promote products 00029 * derived from this software without specific prior written permission. 00030 * 00031 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 00032 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00033 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 00034 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00035 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 00036 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00037 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00038 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 00039 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 00040 * OF SUCH DAMAGE. 00041 * 00042 * This file is part of the lwIP TCP/IP stack. 00043 * 00044 */ 00045 00046 #include "lwip/opt.h" 00047 00048 #if LWIP_ARP || LWIP_ETHERNET 00049 00050 #include "lwip/ip_addr.h" 00051 #include "lwip/def.h" 00052 #include "lwip/ip.h" 00053 #include "lwip/stats.h" 00054 #include "lwip/snmp.h" 00055 #include "lwip/dhcp.h " 00056 #include "lwip/autoip.h" 00057 #include "netif/etharp.h" 00058 00059 #if PPPOE_SUPPORT 00060 #include "netif/ppp_oe.h" 00061 #endif /* PPPOE_SUPPORT */ 00062 00063 #include <string.h> 00064 00065 const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}}; 00066 const struct eth_addr ethzero = {{0,0,0,0,0,0}}; 00067 00068 /** The 24-bit IANA multicast OUI is 01-00-5e: */ 00069 #define LL_MULTICAST_ADDR_0 0x01 00070 #define LL_MULTICAST_ADDR_1 0x00 00071 #define LL_MULTICAST_ADDR_2 0x5e 00072 00073 #if LWIP_ARP /* don't build if not configured for use in lwipopts.h */ 00074 00075 /** the time an ARP entry stays valid after its last update, 00076 * for ARP_TMR_INTERVAL = 5000, this is 00077 * (240 * 5) seconds = 20 minutes. 00078 */ 00079 #define ARP_MAXAGE 240 00080 /** Re-request a used ARP entry 1 minute before it would expire to prevent 00081 * breaking a steadily used connection because the ARP entry timed out. */ 00082 #define ARP_AGE_REREQUEST_USED (ARP_MAXAGE - 12) 00083 00084 /** the time an ARP entry stays pending after first request, 00085 * for ARP_TMR_INTERVAL = 5000, this is 00086 * (2 * 5) seconds = 10 seconds. 00087 * 00088 * @internal Keep this number at least 2, otherwise it might 00089 * run out instantly if the timeout occurs directly after a request. 00090 */ 00091 #define ARP_MAXPENDING 2 00092 00093 #define HWTYPE_ETHERNET 1 00094 00095 enum etharp_state { 00096 ETHARP_STATE_EMPTY = 0, 00097 ETHARP_STATE_PENDING, 00098 ETHARP_STATE_STABLE, 00099 ETHARP_STATE_STABLE_REREQUESTING 00100 #if ETHARP_SUPPORT_STATIC_ENTRIES 00101 ,ETHARP_STATE_STATIC 00102 #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ 00103 }; 00104 00105 struct etharp_entry { 00106 #if ARP_QUEUEING 00107 /** Pointer to queue of pending outgoing packets on this ARP entry. */ 00108 struct etharp_q_entry *q; 00109 #else /* ARP_QUEUEING */ 00110 /** Pointer to a single pending outgoing packet on this ARP entry. */ 00111 struct pbuf *q; 00112 #endif /* ARP_QUEUEING */ 00113 ip_addr_t ipaddr; 00114 struct netif *netif; 00115 struct eth_addr ethaddr; 00116 u8_t state; 00117 u8_t ctime; 00118 }; 00119 00120 static struct etharp_entry arp_table[ARP_TABLE_SIZE]; 00121 00122 #if !LWIP_NETIF_HWADDRHINT 00123 static u8_t etharp_cached_entry; 00124 #endif /* !LWIP_NETIF_HWADDRHINT */ 00125 00126 /** Try hard to create a new entry - we want the IP address to appear in 00127 the cache (even if this means removing an active entry or so). */ 00128 #define ETHARP_FLAG_TRY_HARD 1 00129 #define ETHARP_FLAG_FIND_ONLY 2 00130 #if ETHARP_SUPPORT_STATIC_ENTRIES 00131 #define ETHARP_FLAG_STATIC_ENTRY 4 00132 #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ 00133 00134 #if LWIP_NETIF_HWADDRHINT 00135 #define ETHARP_SET_HINT(netif, hint) if (((netif) != NULL) && ((netif)->addr_hint != NULL)) \ 00136 *((netif)->addr_hint) = (hint); 00137 #else /* LWIP_NETIF_HWADDRHINT */ 00138 #define ETHARP_SET_HINT(netif, hint) (etharp_cached_entry = (hint)) 00139 #endif /* LWIP_NETIF_HWADDRHINT */ 00140 00141 00142 /* Some checks, instead of etharp_init(): */ 00143 #if (LWIP_ARP && (ARP_TABLE_SIZE > 0x7f)) 00144 #error "ARP_TABLE_SIZE must fit in an s8_t, you have to reduce it in your lwipopts.h" 00145 #endif 00146 00147 00148 #if ARP_QUEUEING 00149 /** 00150 * Free a complete queue of etharp entries 00151 * 00152 * @param q a qeueue of etharp_q_entry's to free 00153 */ 00154 static void 00155 free_etharp_q(struct etharp_q_entry *q) 00156 { 00157 struct etharp_q_entry *r; 00158 LWIP_ASSERT("q != NULL", q != NULL); 00159 LWIP_ASSERT("q->p != NULL", q->p != NULL); 00160 while (q) { 00161 r = q; 00162 q = q->next; 00163 LWIP_ASSERT("r->p != NULL", (r->p != NULL)); 00164 pbuf_free(r->p); 00165 memp_free(MEMP_ARP_QUEUE, r); 00166 } 00167 } 00168 #else /* ARP_QUEUEING */ 00169 00170 /** Compatibility define: free the queued pbuf */ 00171 #define free_etharp_q(q) pbuf_free(q) 00172 00173 #endif /* ARP_QUEUEING */ 00174 00175 /** Clean up ARP table entries */ 00176 static void 00177 etharp_free_entry(int i) 00178 { 00179 /* remove from SNMP ARP index tree */ 00180 snmp_delete_arpidx_tree(arp_table[i].netif, &arp_table[i].ipaddr); 00181 /* and empty packet queue */ 00182 if (arp_table[i].q != NULL) { 00183 /* remove all queued packets */ 00184 LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_free_entry: freeing entry %"U16_F", packet queue %p.\n", (u16_t)i, (void *)(arp_table[i].q))); 00185 free_etharp_q(arp_table[i].q); 00186 arp_table[i].q = NULL; 00187 } 00188 /* recycle entry for re-use */ 00189 arp_table[i].state = ETHARP_STATE_EMPTY; 00190 #ifdef LWIP_DEBUG 00191 /* for debugging, clean out the complete entry */ 00192 arp_table[i].ctime = 0; 00193 arp_table[i].netif = NULL; 00194 ip_addr_set_zero(&arp_table[i].ipaddr); 00195 arp_table[i].ethaddr = ethzero; 00196 #endif /* LWIP_DEBUG */ 00197 } 00198 00199 /** 00200 * Clears expired entries in the ARP table. 00201 * 00202 * This function should be called every ETHARP_TMR_INTERVAL milliseconds (5 seconds), 00203 * in order to expire entries in the ARP table. 00204 */ 00205 void 00206 etharp_tmr(void) 00207 { 00208 u8_t i; 00209 00210 LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer\n")); 00211 /* remove expired entries from the ARP table */ 00212 for (i = 0; i < ARP_TABLE_SIZE; ++i) { 00213 u8_t state = arp_table[i].state; 00214 if (state != ETHARP_STATE_EMPTY 00215 #if ETHARP_SUPPORT_STATIC_ENTRIES 00216 && (state != ETHARP_STATE_STATIC) 00217 #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ 00218 ) { 00219 arp_table[i].ctime++; 00220 if ((arp_table[i].ctime >= ARP_MAXAGE) || 00221 ((arp_table[i].state == ETHARP_STATE_PENDING) && 00222 (arp_table[i].ctime >= ARP_MAXPENDING))) { 00223 /* pending or stable entry has become old! */ 00224 LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer: expired %s entry %"U16_F".\n", 00225 arp_table[i].state >= ETHARP_STATE_STABLE ? "stable" : "pending", (u16_t)i)); 00226 /* clean up entries that have just been expired */ 00227 etharp_free_entry(i); 00228 } 00229 else if (arp_table[i].state == ETHARP_STATE_STABLE_REREQUESTING) { 00230 /* Reset state to stable, so that the next transmitted packet will 00231 re-send an ARP request. */ 00232 arp_table[i].state = ETHARP_STATE_STABLE; 00233 } 00234 #if ARP_QUEUEING 00235 /* still pending entry? (not expired) */ 00236 if (arp_table[i].state == ETHARP_STATE_PENDING) { 00237 /* resend an ARP query here? */ 00238 } 00239 #endif /* ARP_QUEUEING */ 00240 } 00241 } 00242 } 00243 00244 /** 00245 * Search the ARP table for a matching or new entry. 00246 * 00247 * If an IP address is given, return a pending or stable ARP entry that matches 00248 * the address. If no match is found, create a new entry with this address set, 00249 * but in state ETHARP_EMPTY. The caller must check and possibly change the 00250 * state of the returned entry. 00251 * 00252 * If ipaddr is NULL, return a initialized new entry in state ETHARP_EMPTY. 00253 * 00254 * In all cases, attempt to create new entries from an empty entry. If no 00255 * empty entries are available and ETHARP_FLAG_TRY_HARD flag is set, recycle 00256 * old entries. Heuristic choose the least important entry for recycling. 00257 * 00258 * @param ipaddr IP address to find in ARP cache, or to add if not found. 00259 * @param flags @see definition of ETHARP_FLAG_* 00260 * @param netif netif related to this address (used for NETIF_HWADDRHINT) 00261 * 00262 * @return The ARP entry index that matched or is created, ERR_MEM if no 00263 * entry is found or could be recycled. 00264 */ 00265 static s8_t 00266 etharp_find_entry(ip_addr_t *ipaddr, u8_t flags) 00267 { 00268 s8_t old_pending = ARP_TABLE_SIZE, old_stable = ARP_TABLE_SIZE; 00269 s8_t empty = ARP_TABLE_SIZE; 00270 u8_t i = 0, age_pending = 0, age_stable = 0; 00271 /* oldest entry with packets on queue */ 00272 s8_t old_queue = ARP_TABLE_SIZE; 00273 /* its age */ 00274 u8_t age_queue = 0; 00275 00276 /** 00277 * a) do a search through the cache, remember candidates 00278 * b) select candidate entry 00279 * c) create new entry 00280 */ 00281 00282 /* a) in a single search sweep, do all of this 00283 * 1) remember the first empty entry (if any) 00284 * 2) remember the oldest stable entry (if any) 00285 * 3) remember the oldest pending entry without queued packets (if any) 00286 * 4) remember the oldest pending entry with queued packets (if any) 00287 * 5) search for a matching IP entry, either pending or stable 00288 * until 5 matches, or all entries are searched for. 00289 */ 00290 00291 for (i = 0; i < ARP_TABLE_SIZE; ++i) { 00292 u8_t state = arp_table[i].state; 00293 /* no empty entry found yet and now we do find one? */ 00294 if ((empty == ARP_TABLE_SIZE) && (state == ETHARP_STATE_EMPTY)) { 00295 LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_find_entry: found empty entry %"U16_F"\n", (u16_t)i)); 00296 /* remember first empty entry */ 00297 empty = i; 00298 } else if (state != ETHARP_STATE_EMPTY) { 00299 LWIP_ASSERT("state == ETHARP_STATE_PENDING || state >= ETHARP_STATE_STABLE", 00300 state == ETHARP_STATE_PENDING || state >= ETHARP_STATE_STABLE); 00301 /* if given, does IP address match IP address in ARP entry? */ 00302 if (ipaddr && ip_addr_cmp(ipaddr, &arp_table[i].ipaddr)) { 00303 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: found matching entry %"U16_F"\n", (u16_t)i)); 00304 /* found exact IP address match, simply bail out */ 00305 return i; 00306 } 00307 /* pending entry? */ 00308 if (state == ETHARP_STATE_PENDING) { 00309 /* pending with queued packets? */ 00310 if (arp_table[i].q != NULL) { 00311 if (arp_table[i].ctime >= age_queue) { 00312 old_queue = i; 00313 age_queue = arp_table[i].ctime; 00314 } 00315 } else 00316 /* pending without queued packets? */ 00317 { 00318 if (arp_table[i].ctime >= age_pending) { 00319 old_pending = i; 00320 age_pending = arp_table[i].ctime; 00321 } 00322 } 00323 /* stable entry? */ 00324 } else if (state >= ETHARP_STATE_STABLE) { 00325 #if ETHARP_SUPPORT_STATIC_ENTRIES 00326 /* don't record old_stable for static entries since they never expire */ 00327 if (state < ETHARP_STATE_STATIC) 00328 #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ 00329 { 00330 /* remember entry with oldest stable entry in oldest, its age in maxtime */ 00331 if (arp_table[i].ctime >= age_stable) { 00332 old_stable = i; 00333 age_stable = arp_table[i].ctime; 00334 } 00335 } 00336 } 00337 } 00338 } 00339 /* { we have no match } => try to create a new entry */ 00340 00341 /* don't create new entry, only search? */ 00342 if (((flags & ETHARP_FLAG_FIND_ONLY) != 0) || 00343 /* or no empty entry found and not allowed to recycle? */ 00344 ((empty == ARP_TABLE_SIZE) && ((flags & ETHARP_FLAG_TRY_HARD) == 0))) { 00345 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: no empty entry found and not allowed to recycle\n")); 00346 return (s8_t)ERR_MEM; 00347 } 00348 00349 /* b) choose the least destructive entry to recycle: 00350 * 1) empty entry 00351 * 2) oldest stable entry 00352 * 3) oldest pending entry without queued packets 00353 * 4) oldest pending entry with queued packets 00354 * 00355 * { ETHARP_FLAG_TRY_HARD is set at this point } 00356 */ 00357 00358 /* 1) empty entry available? */ 00359 if (empty < ARP_TABLE_SIZE) { 00360 i = empty; 00361 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting empty entry %"U16_F"\n", (u16_t)i)); 00362 } else { 00363 /* 2) found recyclable stable entry? */ 00364 if (old_stable < ARP_TABLE_SIZE) { 00365 /* recycle oldest stable*/ 00366 i = old_stable; 00367 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting oldest stable entry %"U16_F"\n", (u16_t)i)); 00368 /* no queued packets should exist on stable entries */ 00369 LWIP_ASSERT("arp_table[i].q == NULL", arp_table[i].q == NULL); 00370 /* 3) found recyclable pending entry without queued packets? */ 00371 } else if (old_pending < ARP_TABLE_SIZE) { 00372 /* recycle oldest pending */ 00373 i = old_pending; 00374 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting oldest pending entry %"U16_F" (without queue)\n", (u16_t)i)); 00375 /* 4) found recyclable pending entry with queued packets? */ 00376 } else if (old_queue < ARP_TABLE_SIZE) { 00377 /* recycle oldest pending (queued packets are free in etharp_free_entry) */ 00378 i = old_queue; 00379 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))); 00380 /* no empty or recyclable entries found */ 00381 } else { 00382 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: no empty or recyclable entries found\n")); 00383 return (s8_t)ERR_MEM; 00384 } 00385 00386 /* { empty or recyclable entry found } */ 00387 LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE); 00388 etharp_free_entry(i); 00389 } 00390 00391 LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE); 00392 LWIP_ASSERT("arp_table[i].state == ETHARP_STATE_EMPTY", 00393 arp_table[i].state == ETHARP_STATE_EMPTY); 00394 00395 /* IP address given? */ 00396 if (ipaddr != NULL) { 00397 /* set IP address */ 00398 ip_addr_copy(arp_table[i].ipaddr, *ipaddr); 00399 } 00400 arp_table[i].ctime = 0; 00401 return (err_t)i; 00402 } 00403 00404 /** 00405 * Send an IP packet on the network using netif->linkoutput 00406 * The ethernet header is filled in before sending. 00407 * 00408 * @params netif the lwIP network interface on which to send the packet 00409 * @params p the packet to send, p->payload pointing to the (uninitialized) ethernet header 00410 * @params src the source MAC address to be copied into the ethernet header 00411 * @params dst the destination MAC address to be copied into the ethernet header 00412 * @return ERR_OK if the packet was sent, any other err_t on failure 00413 */ 00414 static err_t 00415 etharp_send_ip(struct netif *netif, struct pbuf *p, struct eth_addr *src, struct eth_addr *dst) 00416 { 00417 struct eth_hdr *ethhdr = (struct eth_hdr *)p->payload; 00418 00419 LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!", 00420 (netif->hwaddr_len == ETHARP_HWADDR_LEN)); 00421 ETHADDR32_COPY(ðhdr->dest, dst); 00422 ETHADDR16_COPY(ðhdr->src, src); 00423 ethhdr->type = PP_HTONS(ETHTYPE_IP); 00424 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_send_ip: sending packet %p\n", (void *)p)); 00425 /* send the packet */ 00426 return netif->linkoutput(netif, p); 00427 } 00428 00429 /** 00430 * Update (or insert) a IP/MAC address pair in the ARP cache. 00431 * 00432 * If a pending entry is resolved, any queued packets will be sent 00433 * at this point. 00434 * 00435 * @param netif netif related to this entry (used for NETIF_ADDRHINT) 00436 * @param ipaddr IP address of the inserted ARP entry. 00437 * @param ethaddr Ethernet address of the inserted ARP entry. 00438 * @param flags @see definition of ETHARP_FLAG_* 00439 * 00440 * @return 00441 * - ERR_OK Succesfully updated ARP cache. 00442 * - ERR_MEM If we could not add a new ARP entry when ETHARP_FLAG_TRY_HARD was set. 00443 * - ERR_ARG Non-unicast address given, those will not appear in ARP cache. 00444 * 00445 * @see pbuf_free() 00446 */ 00447 static err_t 00448 etharp_update_arp_entry(struct netif *netif, ip_addr_t *ipaddr, struct eth_addr *ethaddr, u8_t flags) 00449 { 00450 s8_t i; 00451 LWIP_ASSERT("netif->hwaddr_len == ETHARP_HWADDR_LEN", netif->hwaddr_len == ETHARP_HWADDR_LEN); 00452 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", 00453 ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr), 00454 ethaddr->addr[0], ethaddr->addr[1], ethaddr->addr[2], 00455 ethaddr->addr[3], ethaddr->addr[4], ethaddr->addr[5])); 00456 /* non-unicast address? */ 00457 if (ip_addr_isany(ipaddr) || 00458 ip_addr_isbroadcast(ipaddr, netif) || 00459 ip_addr_ismulticast(ipaddr)) { 00460 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_update_arp_entry: will not add non-unicast IP address to ARP cache\n")); 00461 return ERR_ARG; 00462 } 00463 /* find or create ARP entry */ 00464 i = etharp_find_entry(ipaddr, flags); 00465 /* bail out if no entry could be found */ 00466 if (i < 0) { 00467 return (err_t)i; 00468 } 00469 00470 #if ETHARP_SUPPORT_STATIC_ENTRIES 00471 if (flags & ETHARP_FLAG_STATIC_ENTRY) { 00472 /* record static type */ 00473 arp_table[i].state = ETHARP_STATE_STATIC; 00474 } else 00475 #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ 00476 { 00477 /* mark it stable */ 00478 arp_table[i].state = ETHARP_STATE_STABLE; 00479 } 00480 00481 /* record network interface */ 00482 arp_table[i].netif = netif; 00483 /* insert in SNMP ARP index tree */ 00484 snmp_insert_arpidx_tree(netif, &arp_table[i].ipaddr); 00485 00486 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_update_arp_entry: updating stable entry %"S16_F"\n", (s16_t)i)); 00487 /* update address */ 00488 ETHADDR32_COPY(&arp_table[i].ethaddr, ethaddr); 00489 /* reset time stamp */ 00490 arp_table[i].ctime = 0; 00491 /* this is where we will send out queued packets! */ 00492 #if ARP_QUEUEING 00493 while (arp_table[i].q != NULL) { 00494 struct pbuf *p; 00495 /* remember remainder of queue */ 00496 struct etharp_q_entry *q = arp_table[i].q; 00497 /* pop first item off the queue */ 00498 arp_table[i].q = q->next; 00499 /* get the packet pointer */ 00500 p = q->p; 00501 /* now queue entry can be freed */ 00502 memp_free(MEMP_ARP_QUEUE, q); 00503 #else /* ARP_QUEUEING */ 00504 if (arp_table[i].q != NULL) { 00505 struct pbuf *p = arp_table[i].q; 00506 arp_table[i].q = NULL; 00507 #endif /* ARP_QUEUEING */ 00508 /* send the queued IP packet */ 00509 etharp_send_ip(netif, p, (struct eth_addr*)(netif->hwaddr), ethaddr); 00510 /* free the queued IP packet */ 00511 pbuf_free(p); 00512 } 00513 return ERR_OK; 00514 } 00515 00516 #if ETHARP_SUPPORT_STATIC_ENTRIES 00517 /** Add a new static entry to the ARP table. If an entry exists for the 00518 * specified IP address, this entry is overwritten. 00519 * If packets are queued for the specified IP address, they are sent out. 00520 * 00521 * @param ipaddr IP address for the new static entry 00522 * @param ethaddr ethernet address for the new static entry 00523 * @return @see return values of etharp_add_static_entry 00524 */ 00525 err_t 00526 etharp_add_static_entry(ip_addr_t *ipaddr, struct eth_addr *ethaddr) 00527 { 00528 struct netif *netif; 00529 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", 00530 ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr), 00531 ethaddr->addr[0], ethaddr->addr[1], ethaddr->addr[2], 00532 ethaddr->addr[3], ethaddr->addr[4], ethaddr->addr[5])); 00533 00534 netif = ip_route(ipaddr); 00535 if (netif == NULL) { 00536 return ERR_RTE; 00537 } 00538 00539 return etharp_update_arp_entry(netif, ipaddr, ethaddr, ETHARP_FLAG_TRY_HARD | ETHARP_FLAG_STATIC_ENTRY); 00540 } 00541 00542 /** Remove a static entry from the ARP table previously added with a call to 00543 * etharp_add_static_entry. 00544 * 00545 * @param ipaddr IP address of the static entry to remove 00546 * @return ERR_OK: entry removed 00547 * ERR_MEM: entry wasn't found 00548 * ERR_ARG: entry wasn't a static entry but a dynamic one 00549 */ 00550 err_t 00551 etharp_remove_static_entry(ip_addr_t *ipaddr) 00552 { 00553 s8_t i; 00554 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_remove_static_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", 00555 ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr))); 00556 00557 /* find or create ARP entry */ 00558 i = etharp_find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY); 00559 /* bail out if no entry could be found */ 00560 if (i < 0) { 00561 return (err_t)i; 00562 } 00563 00564 if (arp_table[i].state != ETHARP_STATE_STATIC) { 00565 /* entry wasn't a static entry, cannot remove it */ 00566 return ERR_ARG; 00567 } 00568 /* entry found, free it */ 00569 etharp_free_entry(i); 00570 return ERR_OK; 00571 } 00572 #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ 00573 00574 /** 00575 * Remove all ARP table entries of the specified netif. 00576 * 00577 * @param netif points to a network interface 00578 */ 00579 void etharp_cleanup_netif(struct netif *netif) 00580 { 00581 u8_t i; 00582 00583 for (i = 0; i < ARP_TABLE_SIZE; ++i) { 00584 u8_t state = arp_table[i].state; 00585 if ((state != ETHARP_STATE_EMPTY) && (arp_table[i].netif == netif)) { 00586 etharp_free_entry(i); 00587 } 00588 } 00589 } 00590 00591 /** 00592 * Finds (stable) ethernet/IP address pair from ARP table 00593 * using interface and IP address index. 00594 * @note the addresses in the ARP table are in network order! 00595 * 00596 * @param netif points to interface index 00597 * @param ipaddr points to the (network order) IP address index 00598 * @param eth_ret points to return pointer 00599 * @param ip_ret points to return pointer 00600 * @return table index if found, -1 otherwise 00601 */ 00602 s8_t 00603 etharp_find_addr(struct netif *netif, ip_addr_t *ipaddr, 00604 struct eth_addr **eth_ret, ip_addr_t **ip_ret) 00605 { 00606 s8_t i; 00607 00608 LWIP_ASSERT("eth_ret != NULL && ip_ret != NULL", 00609 eth_ret != NULL && ip_ret != NULL); 00610 00611 LWIP_UNUSED_ARG(netif); 00612 00613 i = etharp_find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY); 00614 if((i >= 0) && (arp_table[i].state >= ETHARP_STATE_STABLE)) { 00615 *eth_ret = &arp_table[i].ethaddr; 00616 *ip_ret = &arp_table[i].ipaddr; 00617 return i; 00618 } 00619 return -1; 00620 } 00621 00622 #if ETHARP_TRUST_IP_MAC 00623 /** 00624 * Updates the ARP table using the given IP packet. 00625 * 00626 * Uses the incoming IP packet's source address to update the 00627 * ARP cache for the local network. The function does not alter 00628 * or free the packet. This function must be called before the 00629 * packet p is passed to the IP layer. 00630 * 00631 * @param netif The lwIP network interface on which the IP packet pbuf arrived. 00632 * @param p The IP packet that arrived on netif. 00633 * 00634 * @return NULL 00635 * 00636 * @see pbuf_free() 00637 */ 00638 static void 00639 etharp_ip_input(struct netif *netif, struct pbuf *p) 00640 { 00641 struct eth_hdr *ethhdr; 00642 struct ip_hdr *iphdr; 00643 ip_addr_t iphdr_src; 00644 LWIP_ERROR("netif != NULL", (netif != NULL), return;); 00645 00646 /* Only insert an entry if the source IP address of the 00647 incoming IP packet comes from a host on the local network. */ 00648 ethhdr = (struct eth_hdr *)p->payload; 00649 iphdr = (struct ip_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR); 00650 #if ETHARP_SUPPORT_VLAN 00651 if (ethhdr->type == PP_HTONS(ETHTYPE_VLAN)) { 00652 iphdr = (struct ip_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR); 00653 } 00654 #endif /* ETHARP_SUPPORT_VLAN */ 00655 00656 ip_addr_copy(iphdr_src, iphdr->src); 00657 00658 /* source is not on the local network? */ 00659 if (!ip_addr_netcmp(&iphdr_src, &(netif->ip_addr), &(netif->netmask))) { 00660 /* do nothing */ 00661 return; 00662 } 00663 00664 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_ip_input: updating ETHARP table.\n")); 00665 /* update the source IP address in the cache, if present */ 00666 /* @todo We could use ETHARP_FLAG_TRY_HARD if we think we are going to talk 00667 * back soon (for example, if the destination IP address is ours. */ 00668 etharp_update_arp_entry(netif, &iphdr_src, &(ethhdr->src), ETHARP_FLAG_FIND_ONLY); 00669 } 00670 #endif /* ETHARP_TRUST_IP_MAC */ 00671 00672 /** 00673 * Responds to ARP requests to us. Upon ARP replies to us, add entry to cache 00674 * send out queued IP packets. Updates cache with snooped address pairs. 00675 * 00676 * Should be called for incoming ARP packets. The pbuf in the argument 00677 * is freed by this function. 00678 * 00679 * @param netif The lwIP network interface on which the ARP packet pbuf arrived. 00680 * @param ethaddr Ethernet address of netif. 00681 * @param p The ARP packet that arrived on netif. Is freed by this function. 00682 * 00683 * @return NULL 00684 * 00685 * @see pbuf_free() 00686 */ 00687 static void 00688 etharp_arp_input(struct netif *netif, struct eth_addr *ethaddr, struct pbuf *p) 00689 { 00690 struct etharp_hdr *hdr; 00691 struct eth_hdr *ethhdr; 00692 /* these are aligned properly, whereas the ARP header fields might not be */ 00693 ip_addr_t sipaddr, dipaddr; 00694 u8_t for_us; 00695 #if LWIP_AUTOIP 00696 const u8_t * ethdst_hwaddr; 00697 #endif /* LWIP_AUTOIP */ 00698 00699 LWIP_ERROR("netif != NULL", (netif != NULL), return;); 00700 00701 /* drop short ARP packets: we have to check for p->len instead of p->tot_len here 00702 since a struct etharp_hdr is pointed to p->payload, so it musn't be chained! */ 00703 if (p->len < SIZEOF_ETHARP_PACKET) { 00704 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, 00705 ("etharp_arp_input: packet dropped, too short (%"S16_F"/%"S16_F")\n", p->tot_len, 00706 (s16_t)SIZEOF_ETHARP_PACKET)); 00707 ETHARP_STATS_INC(etharp.lenerr); 00708 ETHARP_STATS_INC(etharp.drop); 00709 pbuf_free(p); 00710 return; 00711 } 00712 00713 ethhdr = (struct eth_hdr *)p->payload; 00714 hdr = (struct etharp_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR); 00715 #if ETHARP_SUPPORT_VLAN 00716 if (ethhdr->type == PP_HTONS(ETHTYPE_VLAN)) { 00717 hdr = (struct etharp_hdr *)(((u8_t*)ethhdr) + SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR); 00718 } 00719 #endif /* ETHARP_SUPPORT_VLAN */ 00720 00721 /* RFC 826 "Packet Reception": */ 00722 if ((hdr->hwtype != PP_HTONS(HWTYPE_ETHERNET)) || 00723 (hdr->hwlen != ETHARP_HWADDR_LEN) || 00724 (hdr->protolen != sizeof(ip_addr_t)) || 00725 (hdr->proto != PP_HTONS(ETHTYPE_IP))) { 00726 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, 00727 ("etharp_arp_input: packet dropped, wrong hw type, hwlen, proto, protolen or ethernet type (%"U16_F"/%"U16_F"/%"U16_F"/%"U16_F")\n", 00728 hdr->hwtype, hdr->hwlen, hdr->proto, hdr->protolen)); 00729 ETHARP_STATS_INC(etharp.proterr); 00730 ETHARP_STATS_INC(etharp.drop); 00731 pbuf_free(p); 00732 return; 00733 } 00734 ETHARP_STATS_INC(etharp.recv); 00735 00736 #if LWIP_AUTOIP 00737 /* We have to check if a host already has configured our random 00738 * created link local address and continously check if there is 00739 * a host with this IP-address so we can detect collisions */ 00740 autoip_arp_reply(netif, hdr); 00741 #endif /* LWIP_AUTOIP */ 00742 00743 /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without 00744 * structure packing (not using structure copy which breaks strict-aliasing rules). */ 00745 IPADDR2_COPY(&sipaddr, &hdr->sipaddr); 00746 IPADDR2_COPY(&dipaddr, &hdr->dipaddr); 00747 00748 /* this interface is not configured? */ 00749 if (ip_addr_isany(&netif->ip_addr)) { 00750 for_us = 0; 00751 } else { 00752 /* ARP packet directed to us? */ 00753 for_us = (u8_t)ip_addr_cmp(&dipaddr, &(netif->ip_addr)); 00754 } 00755 00756 /* ARP message directed to us? 00757 -> add IP address in ARP cache; assume requester wants to talk to us, 00758 can result in directly sending the queued packets for this host. 00759 ARP message not directed to us? 00760 -> update the source IP address in the cache, if present */ 00761 etharp_update_arp_entry(netif, &sipaddr, &(hdr->shwaddr), 00762 for_us ? ETHARP_FLAG_TRY_HARD : ETHARP_FLAG_FIND_ONLY); 00763 00764 /* now act on the message itself */ 00765 switch (hdr->opcode) { 00766 /* ARP request? */ 00767 case PP_HTONS(ARP_REQUEST): 00768 /* ARP request. If it asked for our address, we send out a 00769 * reply. In any case, we time-stamp any existing ARP entry, 00770 * and possiby send out an IP packet that was queued on it. */ 00771 00772 LWIP_DEBUGF (ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: incoming ARP request\n")); 00773 /* ARP request for our address? */ 00774 if (for_us) { 00775 00776 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: replying to ARP request for our IP address\n")); 00777 /* Re-use pbuf to send ARP reply. 00778 Since we are re-using an existing pbuf, we can't call etharp_raw since 00779 that would allocate a new pbuf. */ 00780 hdr->opcode = htons(ARP_REPLY); 00781 00782 IPADDR2_COPY(&hdr->dipaddr, &hdr->sipaddr); 00783 IPADDR2_COPY(&hdr->sipaddr, &netif->ip_addr); 00784 00785 LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!", 00786 (netif->hwaddr_len == ETHARP_HWADDR_LEN)); 00787 #if LWIP_AUTOIP 00788 /* If we are using Link-Local, all ARP packets that contain a Link-Local 00789 * 'sender IP address' MUST be sent using link-layer broadcast instead of 00790 * link-layer unicast. (See RFC3927 Section 2.5, last paragraph) */ 00791 ethdst_hwaddr = ip_addr_islinklocal(&netif->ip_addr) ? (u8_t*)(ethbroadcast.addr) : hdr->shwaddr.addr; 00792 #endif /* LWIP_AUTOIP */ 00793 00794 ETHADDR16_COPY(&hdr->dhwaddr, &hdr->shwaddr); 00795 #if LWIP_AUTOIP 00796 ETHADDR16_COPY(ðhdr->dest, ethdst_hwaddr); 00797 #else /* LWIP_AUTOIP */ 00798 ETHADDR16_COPY(ðhdr->dest, &hdr->shwaddr); 00799 #endif /* LWIP_AUTOIP */ 00800 ETHADDR16_COPY(&hdr->shwaddr, ethaddr); 00801 ETHADDR16_COPY(ðhdr->src, ethaddr); 00802 00803 /* hwtype, hwaddr_len, proto, protolen and the type in the ethernet header 00804 are already correct, we tested that before */ 00805 00806 /* return ARP reply */ 00807 netif->linkoutput(netif, p); 00808 /* we are not configured? */ 00809 } else if (ip_addr_isany(&netif->ip_addr)) { 00810 /* { for_us == 0 and netif->ip_addr.addr == 0 } */ 00811 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: we are unconfigured, ARP request ignored.\n")); 00812 /* request was not directed to us */ 00813 } else { 00814 /* { for_us == 0 and netif->ip_addr.addr != 0 } */ 00815 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: ARP request was not for us.\n")); 00816 } 00817 break; 00818 case PP_HTONS(ARP_REPLY): 00819 /* ARP reply. We already updated the ARP cache earlier. */ 00820 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: incoming ARP reply\n")); 00821 #if (LWIP_DHCP && DHCP_DOES_ARP_CHECK) 00822 /* DHCP wants to know about ARP replies from any host with an 00823 * IP address also offered to us by the DHCP server. We do not 00824 * want to take a duplicate IP address on a single network. 00825 * @todo How should we handle redundant (fail-over) interfaces? */ 00826 dhcp_arp_reply(netif, &sipaddr); 00827 #endif /* (LWIP_DHCP && DHCP_DOES_ARP_CHECK) */ 00828 break; 00829 default: 00830 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: ARP unknown opcode type %"S16_F"\n", htons(hdr->opcode))); 00831 ETHARP_STATS_INC(etharp.err); 00832 break; 00833 } 00834 /* free ARP packet */ 00835 pbuf_free(p); 00836 } 00837 00838 /** Just a small helper function that sends a pbuf to an ethernet address 00839 * in the arp_table specified by the index 'arp_idx'. 00840 */ 00841 static err_t 00842 etharp_output_to_arp_index(struct netif *netif, struct pbuf *q, u8_t arp_idx) 00843 { 00844 LWIP_ASSERT("arp_table[arp_idx].state >= ETHARP_STATE_STABLE", 00845 arp_table[arp_idx].state >= ETHARP_STATE_STABLE); 00846 /* if arp table entry is about to expire: re-request it, 00847 but only if its state is ETHARP_STATE_STABLE to prevent flooding the 00848 network with ARP requests if this address is used frequently. */ 00849 if ((arp_table[arp_idx].state == ETHARP_STATE_STABLE) && 00850 (arp_table[arp_idx].ctime >= ARP_AGE_REREQUEST_USED)) { 00851 if (etharp_request(netif, &arp_table[arp_idx].ipaddr) == ERR_OK) { 00852 arp_table[arp_idx].state = ETHARP_STATE_STABLE_REREQUESTING; 00853 } 00854 } 00855 00856 return etharp_send_ip(netif, q, (struct eth_addr*)(netif->hwaddr), 00857 &arp_table[arp_idx].ethaddr); 00858 } 00859 00860 /** 00861 * Resolve and fill-in Ethernet address header for outgoing IP packet. 00862 * 00863 * For IP multicast and broadcast, corresponding Ethernet addresses 00864 * are selected and the packet is transmitted on the link. 00865 * 00866 * For unicast addresses, the packet is submitted to etharp_query(). In 00867 * case the IP address is outside the local network, the IP address of 00868 * the gateway is used. 00869 * 00870 * @param netif The lwIP network interface which the IP packet will be sent on. 00871 * @param q The pbuf(s) containing the IP packet to be sent. 00872 * @param ipaddr The IP address of the packet destination. 00873 * 00874 * @return 00875 * - ERR_RTE No route to destination (no gateway to external networks), 00876 * or the return type of either etharp_query() or etharp_send_ip(). 00877 */ 00878 err_t 00879 etharp_output(struct netif *netif, struct pbuf *q, ip_addr_t *ipaddr) 00880 { 00881 struct eth_addr *dest; 00882 struct eth_addr mcastaddr; 00883 ip_addr_t *dst_addr = ipaddr; 00884 00885 LWIP_ASSERT("netif != NULL", netif != NULL); 00886 LWIP_ASSERT("q != NULL", q != NULL); 00887 LWIP_ASSERT("ipaddr != NULL", ipaddr != NULL); 00888 00889 /* make room for Ethernet header - should not fail */ 00890 if (pbuf_header(q, sizeof(struct eth_hdr)) != 0) { 00891 /* bail out */ 00892 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 00893 ("etharp_output: could not allocate room for header.\n")); 00894 LINK_STATS_INC(link.lenerr); 00895 return ERR_BUF; 00896 } 00897 00898 /* Determine on destination hardware address. Broadcasts and multicasts 00899 * are special, other IP addresses are looked up in the ARP table. */ 00900 00901 /* broadcast destination IP address? */ 00902 if (ip_addr_isbroadcast(ipaddr, netif)) { 00903 /* broadcast on Ethernet also */ 00904 dest = (struct eth_addr *)ðbroadcast; 00905 /* multicast destination IP address? */ 00906 } else if (ip_addr_ismulticast(ipaddr)) { 00907 /* Hash IP multicast address to MAC address.*/ 00908 mcastaddr.addr[0] = LL_MULTICAST_ADDR_0; 00909 mcastaddr.addr[1] = LL_MULTICAST_ADDR_1; 00910 mcastaddr.addr[2] = LL_MULTICAST_ADDR_2; 00911 mcastaddr.addr[3] = ip4_addr2(ipaddr) & 0x7f; 00912 mcastaddr.addr[4] = ip4_addr3(ipaddr); 00913 mcastaddr.addr[5] = ip4_addr4(ipaddr); 00914 /* destination Ethernet address is multicast */ 00915 dest = &mcastaddr; 00916 /* unicast destination IP address? */ 00917 } else { 00918 s8_t i; 00919 /* outside local network? if so, this can neither be a global broadcast nor 00920 a subnet broadcast. */ 00921 if (!ip_addr_netcmp(ipaddr, &(netif->ip_addr), &(netif->netmask)) && 00922 !ip_addr_islinklocal(ipaddr)) { 00923 #if LWIP_AUTOIP 00924 struct ip_hdr *iphdr = (struct ip_hdr*)((u8_t*)q->payload + 00925 sizeof(struct eth_hdr)); 00926 /* According to RFC 3297, chapter 2.6.2 (Forwarding Rules), a packet with 00927 a link-local source address must always be "directly to its destination 00928 on the same physical link. The host MUST NOT send the packet to any 00929 router for forwarding". */ 00930 if (!ip_addr_islinklocal(&iphdr->src)) 00931 #endif /* LWIP_AUTOIP */ 00932 { 00933 /* interface has default gateway? */ 00934 if (!ip_addr_isany(&netif->gw)) { 00935 /* send to hardware address of default gateway IP address */ 00936 dst_addr = &(netif->gw); 00937 /* no default gateway available */ 00938 } else { 00939 /* no route to destination error (default gateway missing) */ 00940 return ERR_RTE; 00941 } 00942 } 00943 } 00944 #if LWIP_NETIF_HWADDRHINT 00945 if (netif->addr_hint != NULL) { 00946 /* per-pcb cached entry was given */ 00947 u8_t etharp_cached_entry = *(netif->addr_hint); 00948 if (etharp_cached_entry < ARP_TABLE_SIZE) { 00949 #endif /* LWIP_NETIF_HWADDRHINT */ 00950 if ((arp_table[etharp_cached_entry].state >= ETHARP_STATE_STABLE) && 00951 (ip_addr_cmp(dst_addr, &arp_table[etharp_cached_entry].ipaddr))) { 00952 /* the per-pcb-cached entry is stable and the right one! */ 00953 ETHARP_STATS_INC(etharp.cachehit); 00954 return etharp_output_to_arp_index(netif, q, etharp_cached_entry); 00955 } 00956 #if LWIP_NETIF_HWADDRHINT 00957 } 00958 } 00959 #endif /* LWIP_NETIF_HWADDRHINT */ 00960 00961 /* find stable entry: do this here since this is a critical path for 00962 throughput and etharp_find_entry() is kind of slow */ 00963 for (i = 0; i < ARP_TABLE_SIZE; i++) { 00964 if ((arp_table[i].state >= ETHARP_STATE_STABLE) && 00965 (ip_addr_cmp(dst_addr, &arp_table[i].ipaddr))) { 00966 /* found an existing, stable entry */ 00967 ETHARP_SET_HINT(netif, i); 00968 return etharp_output_to_arp_index(netif, q, i); 00969 } 00970 } 00971 /* no stable entry found, use the (slower) query function: 00972 queue on destination Ethernet address belonging to ipaddr */ 00973 return etharp_query(netif, dst_addr, q); 00974 } 00975 00976 /* continuation for multicast/broadcast destinations */ 00977 /* obtain source Ethernet address of the given interface */ 00978 /* send packet directly on the link */ 00979 return etharp_send_ip(netif, q, (struct eth_addr*)(netif->hwaddr), dest); 00980 } 00981 00982 /** 00983 * Send an ARP request for the given IP address and/or queue a packet. 00984 * 00985 * If the IP address was not yet in the cache, a pending ARP cache entry 00986 * is added and an ARP request is sent for the given address. The packet 00987 * is queued on this entry. 00988 * 00989 * If the IP address was already pending in the cache, a new ARP request 00990 * is sent for the given address. The packet is queued on this entry. 00991 * 00992 * If the IP address was already stable in the cache, and a packet is 00993 * given, it is directly sent and no ARP request is sent out. 00994 * 00995 * If the IP address was already stable in the cache, and no packet is 00996 * given, an ARP request is sent out. 00997 * 00998 * @param netif The lwIP network interface on which ipaddr 00999 * must be queried for. 01000 * @param ipaddr The IP address to be resolved. 01001 * @param q If non-NULL, a pbuf that must be delivered to the IP address. 01002 * q is not freed by this function. 01003 * 01004 * @note q must only be ONE packet, not a packet queue! 01005 * 01006 * @return 01007 * - ERR_BUF Could not make room for Ethernet header. 01008 * - ERR_MEM Hardware address unknown, and no more ARP entries available 01009 * to query for address or queue the packet. 01010 * - ERR_MEM Could not queue packet due to memory shortage. 01011 * - ERR_RTE No route to destination (no gateway to external networks). 01012 * - ERR_ARG Non-unicast address given, those will not appear in ARP cache. 01013 * 01014 */ 01015 err_t 01016 etharp_query(struct netif *netif, ip_addr_t *ipaddr, struct pbuf *q) 01017 { 01018 struct eth_addr * srcaddr = (struct eth_addr *)netif->hwaddr; 01019 err_t result = ERR_MEM; 01020 s8_t i; /* ARP entry index */ 01021 01022 /* non-unicast address? */ 01023 if (ip_addr_isbroadcast(ipaddr, netif) || 01024 ip_addr_ismulticast(ipaddr) || 01025 ip_addr_isany(ipaddr)) { 01026 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: will not add non-unicast IP address to ARP cache\n")); 01027 return ERR_ARG; 01028 } 01029 01030 /* find entry in ARP cache, ask to create entry if queueing packet */ 01031 i = etharp_find_entry(ipaddr, ETHARP_FLAG_TRY_HARD); 01032 01033 /* could not find or create entry? */ 01034 if (i < 0) { 01035 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: could not create ARP entry\n")); 01036 if (q) { 01037 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: packet dropped\n")); 01038 ETHARP_STATS_INC(etharp.memerr); 01039 } 01040 return (err_t)i; 01041 } 01042 01043 /* mark a fresh entry as pending (we just sent a request) */ 01044 if (arp_table[i].state == ETHARP_STATE_EMPTY) { 01045 arp_table[i].state = ETHARP_STATE_PENDING; 01046 } 01047 01048 /* { i is either a STABLE or (new or existing) PENDING entry } */ 01049 LWIP_ASSERT("arp_table[i].state == PENDING or STABLE", 01050 ((arp_table[i].state == ETHARP_STATE_PENDING) || 01051 (arp_table[i].state >= ETHARP_STATE_STABLE))); 01052 01053 /* do we have a pending entry? or an implicit query request? */ 01054 if ((arp_table[i].state == ETHARP_STATE_PENDING) || (q == NULL)) { 01055 /* try to resolve it; send out ARP request */ 01056 result = etharp_request(netif, ipaddr); 01057 if (result != ERR_OK) { 01058 /* ARP request couldn't be sent */ 01059 /* We don't re-send arp request in etharp_tmr, but we still queue packets, 01060 since this failure could be temporary, and the next packet calling 01061 etharp_query again could lead to sending the queued packets. */ 01062 } 01063 if (q == NULL) { 01064 return result; 01065 } 01066 } 01067 01068 /* packet given? */ 01069 LWIP_ASSERT("q != NULL", q != NULL); 01070 /* stable entry? */ 01071 if (arp_table[i].state >= ETHARP_STATE_STABLE) { 01072 /* we have a valid IP->Ethernet address mapping */ 01073 ETHARP_SET_HINT(netif, i); 01074 /* send the packet */ 01075 result = etharp_send_ip(netif, q, srcaddr, &(arp_table[i].ethaddr)); 01076 /* pending entry? (either just created or already pending */ 01077 } else if (arp_table[i].state == ETHARP_STATE_PENDING) { 01078 /* entry is still pending, queue the given packet 'q' */ 01079 struct pbuf *p; 01080 int copy_needed = 0; 01081 /* IF q includes a PBUF_REF, PBUF_POOL or PBUF_RAM, we have no choice but 01082 * to copy the whole queue into a new PBUF_RAM (see bug #11400) 01083 * PBUF_ROMs can be left as they are, since ROM must not get changed. */ 01084 p = q; 01085 while (p) { 01086 LWIP_ASSERT("no packet queues allowed!", (p->len != p->tot_len) || (p->next == 0)); 01087 if(p->type != PBUF_ROM) { 01088 copy_needed = 1; 01089 break; 01090 } 01091 p = p->next; 01092 } 01093 if(copy_needed) { 01094 /* copy the whole packet into new pbufs */ 01095 p = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM); 01096 if(p != NULL) { 01097 if (pbuf_copy(p, q) != ERR_OK) { 01098 pbuf_free(p); 01099 p = NULL; 01100 } 01101 } 01102 } else { 01103 /* referencing the old pbuf is enough */ 01104 p = q; 01105 pbuf_ref(p); 01106 } 01107 /* packet could be taken over? */ 01108 if (p != NULL) { 01109 /* queue packet ... */ 01110 #if ARP_QUEUEING 01111 struct etharp_q_entry *new_entry; 01112 /* allocate a new arp queue entry */ 01113 new_entry = (struct etharp_q_entry *)memp_malloc(MEMP_ARP_QUEUE); 01114 if (new_entry != NULL) { 01115 new_entry->next = 0; 01116 new_entry->p = p; 01117 if(arp_table[i].q != NULL) { 01118 /* queue was already existent, append the new entry to the end */ 01119 struct etharp_q_entry *r; 01120 r = arp_table[i].q; 01121 while (r->next != NULL) { 01122 r = r->next; 01123 } 01124 r->next = new_entry; 01125 } else { 01126 /* queue did not exist, first item in queue */ 01127 arp_table[i].q = new_entry; 01128 } 01129 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: queued packet %p on ARP entry %"S16_F"\n", (void *)q, (s16_t)i)); 01130 result = ERR_OK; 01131 } else { 01132 /* the pool MEMP_ARP_QUEUE is empty */ 01133 pbuf_free(p); 01134 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)); 01135 result = ERR_MEM; 01136 } 01137 #else /* ARP_QUEUEING */ 01138 /* always queue one packet per ARP request only, freeing a previously queued packet */ 01139 if (arp_table[i].q != NULL) { 01140 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)); 01141 pbuf_free(arp_table[i].q); 01142 } 01143 arp_table[i].q = p; 01144 result = ERR_OK; 01145 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: queued packet %p on ARP entry %"S16_F"\n", (void *)q, (s16_t)i)); 01146 #endif /* ARP_QUEUEING */ 01147 } else { 01148 ETHARP_STATS_INC(etharp.memerr); 01149 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)); 01150 result = ERR_MEM; 01151 } 01152 } 01153 return result; 01154 } 01155 01156 /** 01157 * Send a raw ARP packet (opcode and all addresses can be modified) 01158 * 01159 * @param netif the lwip network interface on which to send the ARP packet 01160 * @param ethsrc_addr the source MAC address for the ethernet header 01161 * @param ethdst_addr the destination MAC address for the ethernet header 01162 * @param hwsrc_addr the source MAC address for the ARP protocol header 01163 * @param ipsrc_addr the source IP address for the ARP protocol header 01164 * @param hwdst_addr the destination MAC address for the ARP protocol header 01165 * @param ipdst_addr the destination IP address for the ARP protocol header 01166 * @param opcode the type of the ARP packet 01167 * @return ERR_OK if the ARP packet has been sent 01168 * ERR_MEM if the ARP packet couldn't be allocated 01169 * any other err_t on failure 01170 */ 01171 #if !LWIP_AUTOIP 01172 static 01173 #endif /* LWIP_AUTOIP */ 01174 err_t 01175 etharp_raw(struct netif *netif, const struct eth_addr *ethsrc_addr, 01176 const struct eth_addr *ethdst_addr, 01177 const struct eth_addr *hwsrc_addr, const ip_addr_t *ipsrc_addr, 01178 const struct eth_addr *hwdst_addr, const ip_addr_t *ipdst_addr, 01179 const u16_t opcode) 01180 { 01181 struct pbuf *p; 01182 err_t result = ERR_OK; 01183 struct eth_hdr *ethhdr; 01184 struct etharp_hdr *hdr; 01185 #if LWIP_AUTOIP 01186 const u8_t * ethdst_hwaddr; 01187 #endif /* LWIP_AUTOIP */ 01188 01189 LWIP_ASSERT("netif != NULL", netif != NULL); 01190 01191 /* allocate a pbuf for the outgoing ARP request packet */ 01192 p = pbuf_alloc(PBUF_RAW, SIZEOF_ETHARP_PACKET, PBUF_RAM); 01193 /* could allocate a pbuf for an ARP request? */ 01194 if (p == NULL) { 01195 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 01196 ("etharp_raw: could not allocate pbuf for ARP request.\n")); 01197 ETHARP_STATS_INC(etharp.memerr); 01198 return ERR_MEM; 01199 } 01200 LWIP_ASSERT("check that first pbuf can hold struct etharp_hdr", 01201 (p->len >= SIZEOF_ETHARP_PACKET)); 01202 01203 ethhdr = (struct eth_hdr *)p->payload; 01204 hdr = (struct etharp_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR); 01205 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_raw: sending raw ARP packet.\n")); 01206 hdr->opcode = htons(opcode); 01207 01208 LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!", 01209 (netif->hwaddr_len == ETHARP_HWADDR_LEN)); 01210 #if LWIP_AUTOIP 01211 /* If we are using Link-Local, all ARP packets that contain a Link-Local 01212 * 'sender IP address' MUST be sent using link-layer broadcast instead of 01213 * link-layer unicast. (See RFC3927 Section 2.5, last paragraph) */ 01214 ethdst_hwaddr = ip_addr_islinklocal(ipsrc_addr) ? (u8_t*)(ethbroadcast.addr) : ethdst_addr->addr; 01215 #endif /* LWIP_AUTOIP */ 01216 /* Write the ARP MAC-Addresses */ 01217 ETHADDR16_COPY(&hdr->shwaddr, hwsrc_addr); 01218 ETHADDR16_COPY(&hdr->dhwaddr, hwdst_addr); 01219 /* Write the Ethernet MAC-Addresses */ 01220 #if LWIP_AUTOIP 01221 ETHADDR16_COPY(ðhdr->dest, ethdst_hwaddr); 01222 #else /* LWIP_AUTOIP */ 01223 ETHADDR16_COPY(ðhdr->dest, ethdst_addr); 01224 #endif /* LWIP_AUTOIP */ 01225 ETHADDR16_COPY(ðhdr->src, ethsrc_addr); 01226 /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without 01227 * structure packing. */ 01228 IPADDR2_COPY(&hdr->sipaddr, ipsrc_addr); 01229 IPADDR2_COPY(&hdr->dipaddr, ipdst_addr); 01230 01231 hdr->hwtype = PP_HTONS(HWTYPE_ETHERNET); 01232 hdr->proto = PP_HTONS(ETHTYPE_IP); 01233 /* set hwlen and protolen */ 01234 hdr->hwlen = ETHARP_HWADDR_LEN; 01235 hdr->protolen = sizeof(ip_addr_t); 01236 01237 ethhdr->type = PP_HTONS(ETHTYPE_ARP); 01238 /* send ARP query */ 01239 result = netif->linkoutput(netif, p); 01240 ETHARP_STATS_INC(etharp.xmit); 01241 /* free ARP query packet */ 01242 pbuf_free(p); 01243 p = NULL; 01244 /* could not allocate pbuf for ARP request */ 01245 01246 return result; 01247 } 01248 01249 /** 01250 * Send an ARP request packet asking for ipaddr. 01251 * 01252 * @param netif the lwip network interface on which to send the request 01253 * @param ipaddr the IP address for which to ask 01254 * @return ERR_OK if the request has been sent 01255 * ERR_MEM if the ARP packet couldn't be allocated 01256 * any other err_t on failure 01257 */ 01258 err_t 01259 etharp_request(struct netif *netif, ip_addr_t *ipaddr) 01260 { 01261 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_request: sending ARP request.\n")); 01262 return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, ðbroadcast, 01263 (struct eth_addr *)netif->hwaddr, &netif->ip_addr, ðzero, 01264 ipaddr, ARP_REQUEST); 01265 } 01266 #endif /* LWIP_ARP */ 01267 01268 /** 01269 * Process received ethernet frames. Using this function instead of directly 01270 * calling ip_input and passing ARP frames through etharp in ethernetif_input, 01271 * the ARP cache is protected from concurrent access. 01272 * 01273 * @param p the recevied packet, p->payload pointing to the ethernet header 01274 * @param netif the network interface on which the packet was received 01275 */ 01276 err_t 01277 ethernet_input(struct pbuf *p, struct netif *netif) 01278 { 01279 struct eth_hdr* ethhdr; 01280 u16_t type; 01281 #if LWIP_ARP || ETHARP_SUPPORT_VLAN 01282 s16_t ip_hdr_offset = SIZEOF_ETH_HDR; 01283 #endif /* LWIP_ARP || ETHARP_SUPPORT_VLAN */ 01284 01285 if (p->len <= SIZEOF_ETH_HDR) { 01286 /* a packet with only an ethernet header (or less) is not valid for us */ 01287 ETHARP_STATS_INC(etharp.proterr); 01288 ETHARP_STATS_INC(etharp.drop); 01289 goto free_and_return; 01290 } 01291 01292 /* points to packet payload, which starts with an Ethernet header */ 01293 ethhdr = (struct eth_hdr *)p->payload; 01294 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, 01295 ("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", 01296 (unsigned)ethhdr->dest.addr[0], (unsigned)ethhdr->dest.addr[1], (unsigned)ethhdr->dest.addr[2], 01297 (unsigned)ethhdr->dest.addr[3], (unsigned)ethhdr->dest.addr[4], (unsigned)ethhdr->dest.addr[5], 01298 (unsigned)ethhdr->src.addr[0], (unsigned)ethhdr->src.addr[1], (unsigned)ethhdr->src.addr[2], 01299 (unsigned)ethhdr->src.addr[3], (unsigned)ethhdr->src.addr[4], (unsigned)ethhdr->src.addr[5], 01300 (unsigned)htons(ethhdr->type))); 01301 01302 type = ethhdr->type; 01303 #if ETHARP_SUPPORT_VLAN 01304 if (type == PP_HTONS(ETHTYPE_VLAN)) { 01305 struct eth_vlan_hdr *vlan = (struct eth_vlan_hdr*)(((char*)ethhdr) + SIZEOF_ETH_HDR); 01306 if (p->len <= SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR) { 01307 /* a packet with only an ethernet/vlan header (or less) is not valid for us */ 01308 ETHARP_STATS_INC(etharp.proterr); 01309 ETHARP_STATS_INC(etharp.drop); 01310 goto free_and_return; 01311 } 01312 #if defined(ETHARP_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK_FN) /* if not, allow all VLANs */ 01313 #ifdef ETHARP_VLAN_CHECK_FN 01314 if (!ETHARP_VLAN_CHECK_FN(ethhdr, vlan)) { 01315 #elif defined(ETHARP_VLAN_CHECK) 01316 if (VLAN_ID(vlan) != ETHARP_VLAN_CHECK) { 01317 #endif 01318 /* silently ignore this packet: not for our VLAN */ 01319 pbuf_free(p); 01320 return ERR_OK; 01321 } 01322 #endif /* defined(ETHARP_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK_FN) */ 01323 type = vlan->tpid; 01324 ip_hdr_offset = SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR; 01325 } 01326 #endif /* ETHARP_SUPPORT_VLAN */ 01327 01328 #if LWIP_ARP_FILTER_NETIF 01329 netif = LWIP_ARP_FILTER_NETIF_FN(p, netif, htons(type)); 01330 #endif /* LWIP_ARP_FILTER_NETIF*/ 01331 01332 if (ethhdr->dest.addr[0] & 1) { 01333 /* this might be a multicast or broadcast packet */ 01334 if (ethhdr->dest.addr[0] == LL_MULTICAST_ADDR_0) { 01335 if ((ethhdr->dest.addr[1] == LL_MULTICAST_ADDR_1) && 01336 (ethhdr->dest.addr[2] == LL_MULTICAST_ADDR_2)) { 01337 /* mark the pbuf as link-layer multicast */ 01338 p->flags |= PBUF_FLAG_LLMCAST; 01339 } 01340 } else if (eth_addr_cmp(ðhdr->dest, ðbroadcast)) { 01341 /* mark the pbuf as link-layer broadcast */ 01342 p->flags |= PBUF_FLAG_LLBCAST; 01343 } 01344 } 01345 01346 switch (type) { 01347 #if LWIP_ARP 01348 /* IP packet? */ 01349 case PP_HTONS(ETHTYPE_IP): 01350 if (!(netif->flags & NETIF_FLAG_ETHARP)) { 01351 goto free_and_return; 01352 } 01353 #if ETHARP_TRUST_IP_MAC 01354 /* update ARP table */ 01355 etharp_ip_input(netif, p); 01356 #endif /* ETHARP_TRUST_IP_MAC */ 01357 /* skip Ethernet header */ 01358 if(pbuf_header(p, -ip_hdr_offset)) { 01359 LWIP_ASSERT("Can't move over header in packet", 0); 01360 goto free_and_return; 01361 } else { 01362 /* pass to IP layer */ 01363 ip_input(p, netif); 01364 } 01365 break; 01366 01367 case PP_HTONS(ETHTYPE_ARP): 01368 if (!(netif->flags & NETIF_FLAG_ETHARP)) { 01369 goto free_and_return; 01370 } 01371 /* pass p to ARP module */ 01372 etharp_arp_input(netif, (struct eth_addr*)(netif->hwaddr), p); 01373 break; 01374 #endif /* LWIP_ARP */ 01375 #if PPPOE_SUPPORT 01376 case PP_HTONS(ETHTYPE_PPPOEDISC): /* PPP Over Ethernet Discovery Stage */ 01377 pppoe_disc_input(netif, p); 01378 break; 01379 01380 case PP_HTONS(ETHTYPE_PPPOE): /* PPP Over Ethernet Session Stage */ 01381 pppoe_data_input(netif, p); 01382 break; 01383 #endif /* PPPOE_SUPPORT */ 01384 01385 default: 01386 ETHARP_STATS_INC(etharp.proterr); 01387 ETHARP_STATS_INC(etharp.drop); 01388 goto free_and_return; 01389 } 01390 01391 /* This means the pbuf is freed or consumed, 01392 so the caller doesn't have to free it again */ 01393 return ERR_OK; 01394 01395 free_and_return: 01396 pbuf_free(p); 01397 return ERR_OK; 01398 } 01399 #endif /* LWIP_ARP || LWIP_ETHERNET */
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