I messed up the merge, so pushing it over to another repo so I don't lose it. Will tidy up and remove later
Dependencies: BufferedSerial FatFileSystemCpp mbed
etharp.c
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 #if LWIP_ARP /* don't build if not configured for use in lwipopts.h */ 00069 00070 /** the time an ARP entry stays valid after its last update, 00071 * for ARP_TMR_INTERVAL = 5000, this is 00072 * (240 * 5) seconds = 20 minutes. 00073 */ 00074 #define ARP_MAXAGE 240 00075 /** the time an ARP entry stays pending after first request, 00076 * for ARP_TMR_INTERVAL = 5000, this is 00077 * (2 * 5) seconds = 10 seconds. 00078 * 00079 * @internal Keep this number at least 2, otherwise it might 00080 * run out instantly if the timeout occurs directly after a request. 00081 */ 00082 #define ARP_MAXPENDING 2 00083 00084 #define HWTYPE_ETHERNET 1 00085 00086 enum etharp_state { 00087 ETHARP_STATE_EMPTY = 0, 00088 ETHARP_STATE_PENDING, 00089 ETHARP_STATE_STABLE 00090 }; 00091 00092 struct etharp_entry { 00093 #if ARP_QUEUEING 00094 /** Pointer to queue of pending outgoing packets on this ARP entry. */ 00095 struct etharp_q_entry *q; 00096 #else /* ARP_QUEUEING */ 00097 /** Pointer to a single pending outgoing packet on this ARP entry. */ 00098 struct pbuf *q; 00099 #endif /* ARP_QUEUEING */ 00100 ip_addr_t ipaddr; 00101 struct eth_addr ethaddr; 00102 #if LWIP_SNMP 00103 struct netif *netif; 00104 #endif /* LWIP_SNMP */ 00105 u8_t state; 00106 u8_t ctime; 00107 #if ETHARP_SUPPORT_STATIC_ENTRIES 00108 u8_t static_entry; 00109 #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ 00110 }; 00111 00112 static struct etharp_entry arp_table[ARP_TABLE_SIZE]; 00113 00114 #if !LWIP_NETIF_HWADDRHINT 00115 static u8_t etharp_cached_entry; 00116 #endif /* !LWIP_NETIF_HWADDRHINT */ 00117 00118 /** Try hard to create a new entry - we want the IP address to appear in 00119 the cache (even if this means removing an active entry or so). */ 00120 #define ETHARP_FLAG_TRY_HARD 1 00121 #define ETHARP_FLAG_FIND_ONLY 2 00122 #define ETHARP_FLAG_STATIC_ENTRY 4 00123 00124 #if LWIP_NETIF_HWADDRHINT 00125 #define ETHARP_SET_HINT(netif, hint) if (((netif) != NULL) && ((netif)->addr_hint != NULL)) \ 00126 *((netif)->addr_hint) = (hint); 00127 #else /* LWIP_NETIF_HWADDRHINT */ 00128 #define ETHARP_SET_HINT(netif, hint) (etharp_cached_entry = (hint)) 00129 #endif /* LWIP_NETIF_HWADDRHINT */ 00130 00131 static err_t update_arp_entry(struct netif *netif, ip_addr_t *ipaddr, struct eth_addr *ethaddr, u8_t flags); 00132 00133 00134 /* Some checks, instead of etharp_init(): */ 00135 #if (LWIP_ARP && (ARP_TABLE_SIZE > 0x7f)) 00136 #error "ARP_TABLE_SIZE must fit in an s8_t, you have to reduce it in your lwipopts.h" 00137 #endif 00138 00139 00140 #if ARP_QUEUEING 00141 /** 00142 * Free a complete queue of etharp entries 00143 * 00144 * @param q a qeueue of etharp_q_entry's to free 00145 */ 00146 static void 00147 free_etharp_q(struct etharp_q_entry *q) 00148 { 00149 struct etharp_q_entry *r; 00150 LWIP_ASSERT("q != NULL", q != NULL); 00151 LWIP_ASSERT("q->p != NULL", q->p != NULL); 00152 while (q) { 00153 r = q; 00154 q = q->next; 00155 LWIP_ASSERT("r->p != NULL", (r->p != NULL)); 00156 pbuf_free(r->p); 00157 memp_free(MEMP_ARP_QUEUE, r); 00158 } 00159 } 00160 #else /* ARP_QUEUEING */ 00161 00162 /** Compatibility define: free the queued pbuf */ 00163 #define free_etharp_q(q) pbuf_free(q) 00164 00165 #endif /* ARP_QUEUEING */ 00166 00167 /** Clean up ARP table entries */ 00168 static void 00169 free_entry(int i) 00170 { 00171 /* remove from SNMP ARP index tree */ 00172 snmp_delete_arpidx_tree(arp_table[i].netif, &arp_table[i].ipaddr); 00173 /* and empty packet queue */ 00174 if (arp_table[i].q != NULL) { 00175 /* remove all queued packets */ 00176 LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer: freeing entry %"U16_F", packet queue %p.\n", (u16_t)i, (void *)(arp_table[i].q))); 00177 free_etharp_q(arp_table[i].q); 00178 arp_table[i].q = NULL; 00179 } 00180 /* recycle entry for re-use */ 00181 arp_table[i].state = ETHARP_STATE_EMPTY; 00182 #if ETHARP_SUPPORT_STATIC_ENTRIES 00183 arp_table[i].static_entry = 0; 00184 #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ 00185 #ifdef LWIP_DEBUG 00186 /* for debugging, clean out the complete entry */ 00187 arp_table[i].ctime = 0; 00188 #if LWIP_SNMP 00189 arp_table[i].netif = NULL; 00190 #endif /* LWIP_SNMP */ 00191 ip_addr_set_zero(&arp_table[i].ipaddr); 00192 arp_table[i].ethaddr = ethzero; 00193 #endif /* LWIP_DEBUG */ 00194 } 00195 00196 /** 00197 * Clears expired entries in the ARP table. 00198 * 00199 * This function should be called every ETHARP_TMR_INTERVAL milliseconds (5 seconds), 00200 * in order to expire entries in the ARP table. 00201 */ 00202 void 00203 etharp_tmr(void) 00204 { 00205 u8_t i; 00206 00207 LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer\n")); 00208 /* remove expired entries from the ARP table */ 00209 for (i = 0; i < ARP_TABLE_SIZE; ++i) { 00210 u8_t state = arp_table[i].state; 00211 if (state != ETHARP_STATE_EMPTY 00212 #if ETHARP_SUPPORT_STATIC_ENTRIES 00213 && (arp_table[i].static_entry == 0) 00214 #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ 00215 ) { 00216 arp_table[i].ctime++; 00217 if ((arp_table[i].ctime >= ARP_MAXAGE) || 00218 ((arp_table[i].state == ETHARP_STATE_PENDING) && 00219 (arp_table[i].ctime >= ARP_MAXPENDING))) { 00220 /* pending or stable entry has become old! */ 00221 LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer: expired %s entry %"U16_F".\n", 00222 arp_table[i].state == ETHARP_STATE_STABLE ? "stable" : "pending", (u16_t)i)); 00223 /* clean up entries that have just been expired */ 00224 free_entry(i); 00225 } 00226 #if ARP_QUEUEING 00227 /* still pending entry? (not expired) */ 00228 if (arp_table[i].state == ETHARP_STATE_PENDING) { 00229 /* resend an ARP query here? */ 00230 } 00231 #endif /* ARP_QUEUEING */ 00232 } 00233 } 00234 } 00235 00236 /** 00237 * Search the ARP table for a matching or new entry. 00238 * 00239 * If an IP address is given, return a pending or stable ARP entry that matches 00240 * the address. If no match is found, create a new entry with this address set, 00241 * but in state ETHARP_EMPTY. The caller must check and possibly change the 00242 * state of the returned entry. 00243 * 00244 * If ipaddr is NULL, return a initialized new entry in state ETHARP_EMPTY. 00245 * 00246 * In all cases, attempt to create new entries from an empty entry. If no 00247 * empty entries are available and ETHARP_FLAG_TRY_HARD flag is set, recycle 00248 * old entries. Heuristic choose the least important entry for recycling. 00249 * 00250 * @param ipaddr IP address to find in ARP cache, or to add if not found. 00251 * @param flags @see definition of ETHARP_FLAG_* 00252 * @param netif netif related to this address (used for NETIF_HWADDRHINT) 00253 * 00254 * @return The ARP entry index that matched or is created, ERR_MEM if no 00255 * entry is found or could be recycled. 00256 */ 00257 static s8_t 00258 find_entry(ip_addr_t *ipaddr, u8_t flags) 00259 { 00260 s8_t old_pending = ARP_TABLE_SIZE, old_stable = ARP_TABLE_SIZE; 00261 s8_t empty = ARP_TABLE_SIZE; 00262 u8_t i = 0, age_pending = 0, age_stable = 0; 00263 /* oldest entry with packets on queue */ 00264 s8_t old_queue = ARP_TABLE_SIZE; 00265 /* its age */ 00266 u8_t age_queue = 0; 00267 00268 /** 00269 * a) do a search through the cache, remember candidates 00270 * b) select candidate entry 00271 * c) create new entry 00272 */ 00273 00274 /* a) in a single search sweep, do all of this 00275 * 1) remember the first empty entry (if any) 00276 * 2) remember the oldest stable entry (if any) 00277 * 3) remember the oldest pending entry without queued packets (if any) 00278 * 4) remember the oldest pending entry with queued packets (if any) 00279 * 5) search for a matching IP entry, either pending or stable 00280 * until 5 matches, or all entries are searched for. 00281 */ 00282 00283 for (i = 0; i < ARP_TABLE_SIZE; ++i) { 00284 u8_t state = arp_table[i].state; 00285 /* no empty entry found yet and now we do find one? */ 00286 if ((empty == ARP_TABLE_SIZE) && (state == ETHARP_STATE_EMPTY)) { 00287 LWIP_DEBUGF(ETHARP_DEBUG, ("find_entry: found empty entry %"U16_F"\n", (u16_t)i)); 00288 /* remember first empty entry */ 00289 empty = i; 00290 } else if (state != ETHARP_STATE_EMPTY) { 00291 LWIP_ASSERT("state == ETHARP_STATE_PENDING || state == ETHARP_STATE_STABLE", 00292 state == ETHARP_STATE_PENDING || state == ETHARP_STATE_STABLE); 00293 /* if given, does IP address match IP address in ARP entry? */ 00294 if (ipaddr && ip_addr_cmp(ipaddr, &arp_table[i].ipaddr)) { 00295 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: found matching entry %"U16_F"\n", (u16_t)i)); 00296 /* found exact IP address match, simply bail out */ 00297 return i; 00298 } 00299 /* pending entry? */ 00300 if (state == ETHARP_STATE_PENDING) { 00301 /* pending with queued packets? */ 00302 if (arp_table[i].q != NULL) { 00303 if (arp_table[i].ctime >= age_queue) { 00304 old_queue = i; 00305 age_queue = arp_table[i].ctime; 00306 } 00307 } else 00308 /* pending without queued packets? */ 00309 { 00310 if (arp_table[i].ctime >= age_pending) { 00311 old_pending = i; 00312 age_pending = arp_table[i].ctime; 00313 } 00314 } 00315 /* stable entry? */ 00316 } else if (state == ETHARP_STATE_STABLE) { 00317 #if ETHARP_SUPPORT_STATIC_ENTRIES 00318 /* don't record old_stable for static entries since they never expire */ 00319 if (arp_table[i].static_entry == 0) 00320 #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ 00321 { 00322 /* remember entry with oldest stable entry in oldest, its age in maxtime */ 00323 if (arp_table[i].ctime >= age_stable) { 00324 old_stable = i; 00325 age_stable = arp_table[i].ctime; 00326 } 00327 } 00328 } 00329 } 00330 } 00331 /* { we have no match } => try to create a new entry */ 00332 00333 /* don't create new entry, only search? */ 00334 if (((flags & ETHARP_FLAG_FIND_ONLY) != 0) || 00335 /* or no empty entry found and not allowed to recycle? */ 00336 ((empty == ARP_TABLE_SIZE) && ((flags & ETHARP_FLAG_TRY_HARD) == 0))) { 00337 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: no empty entry found and not allowed to recycle\n")); 00338 return (s8_t)ERR_MEM; 00339 } 00340 00341 /* b) choose the least destructive entry to recycle: 00342 * 1) empty entry 00343 * 2) oldest stable entry 00344 * 3) oldest pending entry without queued packets 00345 * 4) oldest pending entry with queued packets 00346 * 00347 * { ETHARP_FLAG_TRY_HARD is set at this point } 00348 */ 00349 00350 /* 1) empty entry available? */ 00351 if (empty < ARP_TABLE_SIZE) { 00352 i = empty; 00353 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting empty entry %"U16_F"\n", (u16_t)i)); 00354 } else { 00355 /* 2) found recyclable stable entry? */ 00356 if (old_stable < ARP_TABLE_SIZE) { 00357 /* recycle oldest stable*/ 00358 i = old_stable; 00359 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting oldest stable entry %"U16_F"\n", (u16_t)i)); 00360 /* no queued packets should exist on stable entries */ 00361 LWIP_ASSERT("arp_table[i].q == NULL", arp_table[i].q == NULL); 00362 /* 3) found recyclable pending entry without queued packets? */ 00363 } else if (old_pending < ARP_TABLE_SIZE) { 00364 /* recycle oldest pending */ 00365 i = old_pending; 00366 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting oldest pending entry %"U16_F" (without queue)\n", (u16_t)i)); 00367 /* 4) found recyclable pending entry with queued packets? */ 00368 } else if (old_queue < ARP_TABLE_SIZE) { 00369 /* recycle oldest pending (queued packets are free in free_entry) */ 00370 i = old_queue; 00371 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: selecting oldest pending entry %"U16_F", freeing packet queue %p\n", (u16_t)i, (void *)(arp_table[i].q))); 00372 /* no empty or recyclable entries found */ 00373 } else { 00374 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("find_entry: no empty or recyclable entries found\n")); 00375 return (s8_t)ERR_MEM; 00376 } 00377 00378 /* { empty or recyclable entry found } */ 00379 LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE); 00380 free_entry(i); 00381 } 00382 00383 LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE); 00384 LWIP_ASSERT("arp_table[i].state == ETHARP_STATE_EMPTY", 00385 arp_table[i].state == ETHARP_STATE_EMPTY); 00386 00387 /* IP address given? */ 00388 if (ipaddr != NULL) { 00389 /* set IP address */ 00390 ip_addr_copy(arp_table[i].ipaddr, *ipaddr); 00391 } 00392 arp_table[i].ctime = 0; 00393 #if ETHARP_SUPPORT_STATIC_ENTRIES 00394 arp_table[i].static_entry = 0; 00395 #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ 00396 return (err_t)i; 00397 } 00398 00399 /** 00400 * Send an IP packet on the network using netif->linkoutput 00401 * The ethernet header is filled in before sending. 00402 * 00403 * @params netif the lwIP network interface on which to send the packet 00404 * @params p the packet to send, p->payload pointing to the (uninitialized) ethernet header 00405 * @params src the source MAC address to be copied into the ethernet header 00406 * @params dst the destination MAC address to be copied into the ethernet header 00407 * @return ERR_OK if the packet was sent, any other err_t on failure 00408 */ 00409 static err_t 00410 etharp_send_ip(struct netif *netif, struct pbuf *p, struct eth_addr *src, struct eth_addr *dst) 00411 { 00412 struct eth_hdr *ethhdr = (struct eth_hdr *)p->payload; 00413 00414 LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!", 00415 (netif->hwaddr_len == ETHARP_HWADDR_LEN)); 00416 ETHADDR32_COPY(ðhdr->dest, dst); 00417 ETHADDR16_COPY(ðhdr->src, src); 00418 ethhdr->type = PP_HTONS(ETHTYPE_IP); 00419 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_send_ip: sending packet %p\n", (void *)p)); 00420 /* send the packet */ 00421 return netif->linkoutput(netif, p); 00422 } 00423 00424 /** 00425 * Update (or insert) a IP/MAC address pair in the ARP cache. 00426 * 00427 * If a pending entry is resolved, any queued packets will be sent 00428 * at this point. 00429 * 00430 * @param netif netif related to this entry (used for NETIF_ADDRHINT) 00431 * @param ipaddr IP address of the inserted ARP entry. 00432 * @param ethaddr Ethernet address of the inserted ARP entry. 00433 * @param flags @see definition of ETHARP_FLAG_* 00434 * 00435 * @return 00436 * - ERR_OK Succesfully updated ARP cache. 00437 * - ERR_MEM If we could not add a new ARP entry when ETHARP_FLAG_TRY_HARD was set. 00438 * - ERR_ARG Non-unicast address given, those will not appear in ARP cache. 00439 * 00440 * @see pbuf_free() 00441 */ 00442 static err_t 00443 update_arp_entry(struct netif *netif, ip_addr_t *ipaddr, struct eth_addr *ethaddr, u8_t flags) 00444 { 00445 s8_t i; 00446 LWIP_ASSERT("netif->hwaddr_len == ETHARP_HWADDR_LEN", netif->hwaddr_len == ETHARP_HWADDR_LEN); 00447 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("update_arp_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F" - %02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F"\n", 00448 ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr), 00449 ethaddr->addr[0], ethaddr->addr[1], ethaddr->addr[2], 00450 ethaddr->addr[3], ethaddr->addr[4], ethaddr->addr[5])); 00451 /* non-unicast address? */ 00452 if (ip_addr_isany(ipaddr) || 00453 ip_addr_isbroadcast(ipaddr, netif) || 00454 ip_addr_ismulticast(ipaddr)) { 00455 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("update_arp_entry: will not add non-unicast IP address to ARP cache\n")); 00456 return ERR_ARG; 00457 } 00458 /* find or create ARP entry */ 00459 i = find_entry(ipaddr, flags); 00460 /* bail out if no entry could be found */ 00461 if (i < 0) { 00462 return (err_t)i; 00463 } 00464 00465 #if ETHARP_SUPPORT_STATIC_ENTRIES 00466 if (flags & ETHARP_FLAG_STATIC_ENTRY) { 00467 /* record static type */ 00468 arp_table[i].static_entry = 1; 00469 } 00470 #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ 00471 00472 /* mark it stable */ 00473 arp_table[i].state = ETHARP_STATE_STABLE; 00474 00475 #if LWIP_SNMP 00476 /* record network interface */ 00477 arp_table[i].netif = netif; 00478 #endif /* LWIP_SNMP */ 00479 /* insert in SNMP ARP index tree */ 00480 snmp_insert_arpidx_tree(netif, &arp_table[i].ipaddr); 00481 00482 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("update_arp_entry: updating stable entry %"S16_F"\n", (s16_t)i)); 00483 /* update address */ 00484 ETHADDR32_COPY(&arp_table[i].ethaddr, ethaddr); 00485 /* reset time stamp */ 00486 arp_table[i].ctime = 0; 00487 /* this is where we will send out queued packets! */ 00488 #if ARP_QUEUEING 00489 while (arp_table[i].q != NULL) { 00490 struct pbuf *p; 00491 /* remember remainder of queue */ 00492 struct etharp_q_entry *q = arp_table[i].q; 00493 /* pop first item off the queue */ 00494 arp_table[i].q = q->next; 00495 /* get the packet pointer */ 00496 p = q->p; 00497 /* now queue entry can be freed */ 00498 memp_free(MEMP_ARP_QUEUE, q); 00499 #else /* ARP_QUEUEING */ 00500 if (arp_table[i].q != NULL) { 00501 struct pbuf *p = arp_table[i].q; 00502 arp_table[i].q = NULL; 00503 #endif /* ARP_QUEUEING */ 00504 /* send the queued IP packet */ 00505 etharp_send_ip(netif, p, (struct eth_addr*)(netif->hwaddr), ethaddr); 00506 /* free the queued IP packet */ 00507 pbuf_free(p); 00508 } 00509 return ERR_OK; 00510 } 00511 00512 #if ETHARP_SUPPORT_STATIC_ENTRIES 00513 /** Add a new static entry to the ARP table. If an entry exists for the 00514 * specified IP address, this entry is overwritten. 00515 * If packets are queued for the specified IP address, they are sent out. 00516 * 00517 * @param ipaddr IP address for the new static entry 00518 * @param ethaddr ethernet address for the new static entry 00519 * @return @see return values of etharp_add_static_entry 00520 */ 00521 err_t 00522 etharp_add_static_entry(ip_addr_t *ipaddr, struct eth_addr *ethaddr) 00523 { 00524 struct netif *netif; 00525 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", 00526 ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr), 00527 ethaddr->addr[0], ethaddr->addr[1], ethaddr->addr[2], 00528 ethaddr->addr[3], ethaddr->addr[4], ethaddr->addr[5])); 00529 00530 netif = ip_route(ipaddr); 00531 if (netif == NULL) { 00532 return ERR_RTE; 00533 } 00534 00535 return update_arp_entry(netif, ipaddr, ethaddr, ETHARP_FLAG_TRY_HARD | ETHARP_FLAG_STATIC_ENTRY); 00536 } 00537 00538 /** Remove a static entry from the ARP table previously added with a call to 00539 * etharp_add_static_entry. 00540 * 00541 * @param ipaddr IP address of the static entry to remove 00542 * @return ERR_OK: entry removed 00543 * ERR_MEM: entry wasn't found 00544 * ERR_ARG: entry wasn't a static entry but a dynamic one 00545 */ 00546 err_t 00547 etharp_remove_static_entry(ip_addr_t *ipaddr) 00548 { 00549 s8_t i; 00550 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_remove_static_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", 00551 ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr))); 00552 00553 /* find or create ARP entry */ 00554 i = find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY); 00555 /* bail out if no entry could be found */ 00556 if (i < 0) { 00557 return (err_t)i; 00558 } 00559 00560 if ((arp_table[i].state != ETHARP_STATE_STABLE) || 00561 (arp_table[i].static_entry == 0)) { 00562 /* entry wasn't a static entry, cannot remove it */ 00563 return ERR_ARG; 00564 } 00565 /* entry found, free it */ 00566 free_entry(i); 00567 return ERR_OK; 00568 } 00569 #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */ 00570 00571 /** 00572 * Finds (stable) ethernet/IP address pair from ARP table 00573 * using interface and IP address index. 00574 * @note the addresses in the ARP table are in network order! 00575 * 00576 * @param netif points to interface index 00577 * @param ipaddr points to the (network order) IP address index 00578 * @param eth_ret points to return pointer 00579 * @param ip_ret points to return pointer 00580 * @return table index if found, -1 otherwise 00581 */ 00582 s8_t 00583 etharp_find_addr(struct netif *netif, ip_addr_t *ipaddr, 00584 struct eth_addr **eth_ret, ip_addr_t **ip_ret) 00585 { 00586 s8_t i; 00587 00588 LWIP_ASSERT("eth_ret != NULL && ip_ret != NULL", 00589 eth_ret != NULL && ip_ret != NULL); 00590 00591 LWIP_UNUSED_ARG(netif); 00592 00593 i = find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY); 00594 if((i >= 0) && arp_table[i].state == ETHARP_STATE_STABLE) { 00595 *eth_ret = &arp_table[i].ethaddr; 00596 *ip_ret = &arp_table[i].ipaddr; 00597 return i; 00598 } 00599 return -1; 00600 } 00601 00602 #if ETHARP_TRUST_IP_MAC 00603 /** 00604 * Updates the ARP table using the given IP packet. 00605 * 00606 * Uses the incoming IP packet's source address to update the 00607 * ARP cache for the local network. The function does not alter 00608 * or free the packet. This function must be called before the 00609 * packet p is passed to the IP layer. 00610 * 00611 * @param netif The lwIP network interface on which the IP packet pbuf arrived. 00612 * @param p The IP packet that arrived on netif. 00613 * 00614 * @return NULL 00615 * 00616 * @see pbuf_free() 00617 */ 00618 static void 00619 etharp_ip_input(struct netif *netif, struct pbuf *p) 00620 { 00621 struct eth_hdr *ethhdr; 00622 struct ip_hdr *iphdr; 00623 ip_addr_t iphdr_src; 00624 LWIP_ERROR("netif != NULL", (netif != NULL), return;); 00625 00626 /* Only insert an entry if the source IP address of the 00627 incoming IP packet comes from a host on the local network. */ 00628 ethhdr = (struct eth_hdr *)p->payload; 00629 iphdr = (struct ip_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR); 00630 #if ETHARP_SUPPORT_VLAN 00631 if (ethhdr->type == PP_HTONS(ETHTYPE_VLAN)) { 00632 iphdr = (struct ip_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR); 00633 } 00634 #endif /* ETHARP_SUPPORT_VLAN */ 00635 00636 ip_addr_copy(iphdr_src, iphdr->src); 00637 00638 /* source is not on the local network? */ 00639 if (!ip_addr_netcmp(&iphdr_src, &(netif->ip_addr), &(netif->netmask))) { 00640 /* do nothing */ 00641 return; 00642 } 00643 00644 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_ip_input: updating ETHARP table.\n")); 00645 /* update the source IP address in the cache, if present */ 00646 /* @todo We could use ETHARP_FLAG_TRY_HARD if we think we are going to talk 00647 * back soon (for example, if the destination IP address is ours. */ 00648 update_arp_entry(netif, &iphdr_src, &(ethhdr->src), ETHARP_FLAG_FIND_ONLY); 00649 } 00650 #endif /* ETHARP_TRUST_IP_MAC */ 00651 00652 /** 00653 * Responds to ARP requests to us. Upon ARP replies to us, add entry to cache 00654 * send out queued IP packets. Updates cache with snooped address pairs. 00655 * 00656 * Should be called for incoming ARP packets. The pbuf in the argument 00657 * is freed by this function. 00658 * 00659 * @param netif The lwIP network interface on which the ARP packet pbuf arrived. 00660 * @param ethaddr Ethernet address of netif. 00661 * @param p The ARP packet that arrived on netif. Is freed by this function. 00662 * 00663 * @return NULL 00664 * 00665 * @see pbuf_free() 00666 */ 00667 static void 00668 etharp_arp_input(struct netif *netif, struct eth_addr *ethaddr, struct pbuf *p) 00669 { 00670 struct etharp_hdr *hdr; 00671 struct eth_hdr *ethhdr; 00672 /* these are aligned properly, whereas the ARP header fields might not be */ 00673 ip_addr_t sipaddr, dipaddr; 00674 u8_t for_us; 00675 #if LWIP_AUTOIP 00676 const u8_t * ethdst_hwaddr; 00677 #endif /* LWIP_AUTOIP */ 00678 00679 LWIP_ERROR("netif != NULL", (netif != NULL), return;); 00680 00681 /* drop short ARP packets: we have to check for p->len instead of p->tot_len here 00682 since a struct etharp_hdr is pointed to p->payload, so it musn't be chained! */ 00683 if (p->len < SIZEOF_ETHARP_PACKET) { 00684 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, 00685 ("etharp_arp_input: packet dropped, too short (%"S16_F"/%"S16_F")\n", p->tot_len, 00686 (s16_t)SIZEOF_ETHARP_PACKET)); 00687 ETHARP_STATS_INC(etharp.lenerr); 00688 ETHARP_STATS_INC(etharp.drop); 00689 pbuf_free(p); 00690 return; 00691 } 00692 00693 ethhdr = (struct eth_hdr *)p->payload; 00694 hdr = (struct etharp_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR); 00695 #if ETHARP_SUPPORT_VLAN 00696 if (ethhdr->type == PP_HTONS(ETHTYPE_VLAN)) { 00697 hdr = (struct etharp_hdr *)(((u8_t*)ethhdr) + SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR); 00698 } 00699 #endif /* ETHARP_SUPPORT_VLAN */ 00700 00701 /* RFC 826 "Packet Reception": */ 00702 if ((hdr->hwtype != PP_HTONS(HWTYPE_ETHERNET)) || 00703 (hdr->hwlen != ETHARP_HWADDR_LEN) || 00704 (hdr->protolen != sizeof(ip_addr_t)) || 00705 (hdr->proto != PP_HTONS(ETHTYPE_IP))) { 00706 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, 00707 ("etharp_arp_input: packet dropped, wrong hw type, hwlen, proto, protolen or ethernet type (%"U16_F"/%"U16_F"/%"U16_F"/%"U16_F")\n", 00708 hdr->hwtype, hdr->hwlen, hdr->proto, hdr->protolen)); 00709 ETHARP_STATS_INC(etharp.proterr); 00710 ETHARP_STATS_INC(etharp.drop); 00711 pbuf_free(p); 00712 return; 00713 } 00714 ETHARP_STATS_INC(etharp.recv); 00715 00716 #if LWIP_AUTOIP 00717 /* We have to check if a host already has configured our random 00718 * created link local address and continously check if there is 00719 * a host with this IP-address so we can detect collisions */ 00720 autoip_arp_reply(netif, hdr); 00721 #endif /* LWIP_AUTOIP */ 00722 00723 /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without 00724 * structure packing (not using structure copy which breaks strict-aliasing rules). */ 00725 IPADDR2_COPY(&sipaddr, &hdr->sipaddr); 00726 IPADDR2_COPY(&dipaddr, &hdr->dipaddr); 00727 00728 /* this interface is not configured? */ 00729 if (ip_addr_isany(&netif->ip_addr)) { 00730 for_us = 0; 00731 } else { 00732 /* ARP packet directed to us? */ 00733 for_us = (u8_t)ip_addr_cmp(&dipaddr, &(netif->ip_addr)); 00734 } 00735 00736 /* ARP message directed to us? 00737 -> add IP address in ARP cache; assume requester wants to talk to us, 00738 can result in directly sending the queued packets for this host. 00739 ARP message not directed to us? 00740 -> update the source IP address in the cache, if present */ 00741 update_arp_entry(netif, &sipaddr, &(hdr->shwaddr), 00742 for_us ? ETHARP_FLAG_TRY_HARD : ETHARP_FLAG_FIND_ONLY); 00743 00744 /* now act on the message itself */ 00745 switch (hdr->opcode) { 00746 /* ARP request? */ 00747 case PP_HTONS(ARP_REQUEST): 00748 /* ARP request. If it asked for our address, we send out a 00749 * reply. In any case, we time-stamp any existing ARP entry, 00750 * and possiby send out an IP packet that was queued on it. */ 00751 00752 LWIP_DEBUGF (ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: incoming ARP request\n")); 00753 /* ARP request for our address? */ 00754 if (for_us) { 00755 00756 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: replying to ARP request for our IP address\n")); 00757 /* Re-use pbuf to send ARP reply. 00758 Since we are re-using an existing pbuf, we can't call etharp_raw since 00759 that would allocate a new pbuf. */ 00760 hdr->opcode = htons(ARP_REPLY); 00761 00762 IPADDR2_COPY(&hdr->dipaddr, &hdr->sipaddr); 00763 IPADDR2_COPY(&hdr->sipaddr, &netif->ip_addr); 00764 00765 LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!", 00766 (netif->hwaddr_len == ETHARP_HWADDR_LEN)); 00767 #if LWIP_AUTOIP 00768 /* If we are using Link-Local, all ARP packets that contain a Link-Local 00769 * 'sender IP address' MUST be sent using link-layer broadcast instead of 00770 * link-layer unicast. (See RFC3927 Section 2.5, last paragraph) */ 00771 ethdst_hwaddr = ip_addr_islinklocal(&netif->ip_addr) ? (u8_t*)(ethbroadcast.addr) : hdr->shwaddr.addr; 00772 #endif /* LWIP_AUTOIP */ 00773 00774 ETHADDR16_COPY(&hdr->dhwaddr, &hdr->shwaddr); 00775 #if LWIP_AUTOIP 00776 ETHADDR16_COPY(ðhdr->dest, ethdst_hwaddr); 00777 #else /* LWIP_AUTOIP */ 00778 ETHADDR16_COPY(ðhdr->dest, &hdr->shwaddr); 00779 #endif /* LWIP_AUTOIP */ 00780 ETHADDR16_COPY(&hdr->shwaddr, ethaddr); 00781 ETHADDR16_COPY(ðhdr->src, ethaddr); 00782 00783 /* hwtype, hwaddr_len, proto, protolen and the type in the ethernet header 00784 are already correct, we tested that before */ 00785 00786 /* return ARP reply */ 00787 netif->linkoutput(netif, p); 00788 /* we are not configured? */ 00789 } else if (ip_addr_isany(&netif->ip_addr)) { 00790 /* { for_us == 0 and netif->ip_addr.addr == 0 } */ 00791 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: we are unconfigured, ARP request ignored.\n")); 00792 /* request was not directed to us */ 00793 } else { 00794 /* { for_us == 0 and netif->ip_addr.addr != 0 } */ 00795 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: ARP request was not for us.\n")); 00796 } 00797 break; 00798 case PP_HTONS(ARP_REPLY): 00799 /* ARP reply. We already updated the ARP cache earlier. */ 00800 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: incoming ARP reply\n")); 00801 #if (LWIP_DHCP && DHCP_DOES_ARP_CHECK) 00802 /* DHCP wants to know about ARP replies from any host with an 00803 * IP address also offered to us by the DHCP server. We do not 00804 * want to take a duplicate IP address on a single network. 00805 * @todo How should we handle redundant (fail-over) interfaces? */ 00806 dhcp_arp_reply(netif, &sipaddr); 00807 #endif /* (LWIP_DHCP && DHCP_DOES_ARP_CHECK) */ 00808 break; 00809 default: 00810 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: ARP unknown opcode type %"S16_F"\n", htons(hdr->opcode))); 00811 ETHARP_STATS_INC(etharp.err); 00812 break; 00813 } 00814 /* free ARP packet */ 00815 pbuf_free(p); 00816 } 00817 00818 /** 00819 * Resolve and fill-in Ethernet address header for outgoing IP packet. 00820 * 00821 * For IP multicast and broadcast, corresponding Ethernet addresses 00822 * are selected and the packet is transmitted on the link. 00823 * 00824 * For unicast addresses, the packet is submitted to etharp_query(). In 00825 * case the IP address is outside the local network, the IP address of 00826 * the gateway is used. 00827 * 00828 * @param netif The lwIP network interface which the IP packet will be sent on. 00829 * @param q The pbuf(s) containing the IP packet to be sent. 00830 * @param ipaddr The IP address of the packet destination. 00831 * 00832 * @return 00833 * - ERR_RTE No route to destination (no gateway to external networks), 00834 * or the return type of either etharp_query() or etharp_send_ip(). 00835 */ 00836 err_t 00837 etharp_output(struct netif *netif, struct pbuf *q, ip_addr_t *ipaddr) 00838 { 00839 struct eth_addr *dest, mcastaddr; 00840 00841 /* make room for Ethernet header - should not fail */ 00842 if (pbuf_header(q, sizeof(struct eth_hdr)) != 0) { 00843 /* bail out */ 00844 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 00845 ("etharp_output: could not allocate room for header.\n")); 00846 LINK_STATS_INC(link.lenerr); 00847 return ERR_BUF; 00848 } 00849 00850 /* assume unresolved Ethernet address */ 00851 dest = NULL; 00852 /* Determine on destination hardware address. Broadcasts and multicasts 00853 * are special, other IP addresses are looked up in the ARP table. */ 00854 00855 /* broadcast destination IP address? */ 00856 if (ip_addr_isbroadcast(ipaddr, netif)) { 00857 /* broadcast on Ethernet also */ 00858 dest = (struct eth_addr *)ðbroadcast; 00859 /* multicast destination IP address? */ 00860 } else if (ip_addr_ismulticast(ipaddr)) { 00861 /* Hash IP multicast address to MAC address.*/ 00862 mcastaddr.addr[0] = 0x01; 00863 mcastaddr.addr[1] = 0x00; 00864 mcastaddr.addr[2] = 0x5e; 00865 mcastaddr.addr[3] = ip4_addr2(ipaddr) & 0x7f; 00866 mcastaddr.addr[4] = ip4_addr3(ipaddr); 00867 mcastaddr.addr[5] = ip4_addr4(ipaddr); 00868 /* destination Ethernet address is multicast */ 00869 dest = &mcastaddr; 00870 /* unicast destination IP address? */ 00871 } else { 00872 /* outside local network? */ 00873 if (!ip_addr_netcmp(ipaddr, &(netif->ip_addr), &(netif->netmask)) && 00874 !ip_addr_islinklocal(ipaddr)) { 00875 #if LWIP_AUTOIP 00876 struct ip_hdr *iphdr = (struct ip_hdr*)((u8_t*)q->payload + 00877 sizeof(struct eth_hdr)); 00878 /* According to RFC 3297, chapter 2.6.2 (Forwarding Rules), a packet with 00879 a link-local source address must always be "directly to its destination 00880 on the same physical link. The host MUST NOT send the packet to any 00881 router for forwarding". */ 00882 if (!ip_addr_islinklocal(&iphdr->src)) 00883 #endif /* LWIP_AUTOIP */ 00884 { 00885 /* interface has default gateway? */ 00886 if (!ip_addr_isany(&netif->gw)) { 00887 /* send to hardware address of default gateway IP address */ 00888 ipaddr = &(netif->gw); 00889 /* no default gateway available */ 00890 } else { 00891 /* no route to destination error (default gateway missing) */ 00892 return ERR_RTE; 00893 } 00894 } 00895 } 00896 #if LWIP_NETIF_HWADDRHINT 00897 if (netif->addr_hint != NULL) { 00898 /* per-pcb cached entry was given */ 00899 u8_t etharp_cached_entry = *(netif->addr_hint); 00900 if (etharp_cached_entry < ARP_TABLE_SIZE) { 00901 #endif /* LWIP_NETIF_HWADDRHINT */ 00902 if ((arp_table[etharp_cached_entry].state == ETHARP_STATE_STABLE) && 00903 (ip_addr_cmp(ipaddr, &arp_table[etharp_cached_entry].ipaddr))) { 00904 /* the per-pcb-cached entry is stable and the right one! */ 00905 ETHARP_STATS_INC(etharp.cachehit); 00906 return etharp_send_ip(netif, q, (struct eth_addr*)(netif->hwaddr), 00907 &arp_table[etharp_cached_entry].ethaddr); 00908 } 00909 #if LWIP_NETIF_HWADDRHINT 00910 } 00911 } 00912 #endif /* LWIP_NETIF_HWADDRHINT */ 00913 /* queue on destination Ethernet address belonging to ipaddr */ 00914 return etharp_query(netif, ipaddr, q); 00915 } 00916 00917 /* continuation for multicast/broadcast destinations */ 00918 /* obtain source Ethernet address of the given interface */ 00919 /* send packet directly on the link */ 00920 return etharp_send_ip(netif, q, (struct eth_addr*)(netif->hwaddr), dest); 00921 } 00922 00923 /** 00924 * Send an ARP request for the given IP address and/or queue a packet. 00925 * 00926 * If the IP address was not yet in the cache, a pending ARP cache entry 00927 * is added and an ARP request is sent for the given address. The packet 00928 * is queued on this entry. 00929 * 00930 * If the IP address was already pending in the cache, a new ARP request 00931 * is sent for the given address. The packet is queued on this entry. 00932 * 00933 * If the IP address was already stable in the cache, and a packet is 00934 * given, it is directly sent and no ARP request is sent out. 00935 * 00936 * If the IP address was already stable in the cache, and no packet is 00937 * given, an ARP request is sent out. 00938 * 00939 * @param netif The lwIP network interface on which ipaddr 00940 * must be queried for. 00941 * @param ipaddr The IP address to be resolved. 00942 * @param q If non-NULL, a pbuf that must be delivered to the IP address. 00943 * q is not freed by this function. 00944 * 00945 * @note q must only be ONE packet, not a packet queue! 00946 * 00947 * @return 00948 * - ERR_BUF Could not make room for Ethernet header. 00949 * - ERR_MEM Hardware address unknown, and no more ARP entries available 00950 * to query for address or queue the packet. 00951 * - ERR_MEM Could not queue packet due to memory shortage. 00952 * - ERR_RTE No route to destination (no gateway to external networks). 00953 * - ERR_ARG Non-unicast address given, those will not appear in ARP cache. 00954 * 00955 */ 00956 err_t 00957 etharp_query(struct netif *netif, ip_addr_t *ipaddr, struct pbuf *q) 00958 { 00959 struct eth_addr * srcaddr = (struct eth_addr *)netif->hwaddr; 00960 err_t result = ERR_MEM; 00961 s8_t i; /* ARP entry index */ 00962 00963 /* non-unicast address? */ 00964 if (ip_addr_isbroadcast(ipaddr, netif) || 00965 ip_addr_ismulticast(ipaddr) || 00966 ip_addr_isany(ipaddr)) { 00967 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: will not add non-unicast IP address to ARP cache\n")); 00968 return ERR_ARG; 00969 } 00970 00971 /* find entry in ARP cache, ask to create entry if queueing packet */ 00972 i = find_entry(ipaddr, ETHARP_FLAG_TRY_HARD); 00973 00974 /* could not find or create entry? */ 00975 if (i < 0) { 00976 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: could not create ARP entry\n")); 00977 if (q) { 00978 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: packet dropped\n")); 00979 ETHARP_STATS_INC(etharp.memerr); 00980 } 00981 return (err_t)i; 00982 } 00983 00984 /* mark a fresh entry as pending (we just sent a request) */ 00985 if (arp_table[i].state == ETHARP_STATE_EMPTY) { 00986 arp_table[i].state = ETHARP_STATE_PENDING; 00987 } 00988 00989 /* { i is either a STABLE or (new or existing) PENDING entry } */ 00990 LWIP_ASSERT("arp_table[i].state == PENDING or STABLE", 00991 ((arp_table[i].state == ETHARP_STATE_PENDING) || 00992 (arp_table[i].state == ETHARP_STATE_STABLE))); 00993 00994 /* do we have a pending entry? or an implicit query request? */ 00995 if ((arp_table[i].state == ETHARP_STATE_PENDING) || (q == NULL)) { 00996 /* try to resolve it; send out ARP request */ 00997 result = etharp_request(netif, ipaddr); 00998 if (result != ERR_OK) { 00999 /* ARP request couldn't be sent */ 01000 /* We don't re-send arp request in etharp_tmr, but we still queue packets, 01001 since this failure could be temporary, and the next packet calling 01002 etharp_query again could lead to sending the queued packets. */ 01003 } 01004 if (q == NULL) { 01005 return result; 01006 } 01007 } 01008 01009 /* packet given? */ 01010 LWIP_ASSERT("q != NULL", q != NULL); 01011 /* stable entry? */ 01012 if (arp_table[i].state == ETHARP_STATE_STABLE) { 01013 /* we have a valid IP->Ethernet address mapping */ 01014 ETHARP_SET_HINT(netif, i); 01015 /* send the packet */ 01016 result = etharp_send_ip(netif, q, srcaddr, &(arp_table[i].ethaddr)); 01017 /* pending entry? (either just created or already pending */ 01018 } else if (arp_table[i].state == ETHARP_STATE_PENDING) { 01019 /* entry is still pending, queue the given packet 'q' */ 01020 struct pbuf *p; 01021 int copy_needed = 0; 01022 /* IF q includes a PBUF_REF, PBUF_POOL or PBUF_RAM, we have no choice but 01023 * to copy the whole queue into a new PBUF_RAM (see bug #11400) 01024 * PBUF_ROMs can be left as they are, since ROM must not get changed. */ 01025 p = q; 01026 while (p) { 01027 LWIP_ASSERT("no packet queues allowed!", (p->len != p->tot_len) || (p->next == 0)); 01028 if(p->type != PBUF_ROM) { 01029 copy_needed = 1; 01030 break; 01031 } 01032 p = p->next; 01033 } 01034 if(copy_needed) { 01035 /* copy the whole packet into new pbufs */ 01036 p = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM); 01037 if(p != NULL) { 01038 if (pbuf_copy(p, q) != ERR_OK) { 01039 pbuf_free(p); 01040 p = NULL; 01041 } 01042 } 01043 } else { 01044 /* referencing the old pbuf is enough */ 01045 p = q; 01046 pbuf_ref(p); 01047 } 01048 /* packet could be taken over? */ 01049 if (p != NULL) { 01050 /* queue packet ... */ 01051 #if ARP_QUEUEING 01052 struct etharp_q_entry *new_entry; 01053 /* allocate a new arp queue entry */ 01054 new_entry = (struct etharp_q_entry *)memp_malloc(MEMP_ARP_QUEUE); 01055 if (new_entry != NULL) { 01056 new_entry->next = 0; 01057 new_entry->p = p; 01058 if(arp_table[i].q != NULL) { 01059 /* queue was already existent, append the new entry to the end */ 01060 struct etharp_q_entry *r; 01061 r = arp_table[i].q; 01062 while (r->next != NULL) { 01063 r = r->next; 01064 } 01065 r->next = new_entry; 01066 } else { 01067 /* queue did not exist, first item in queue */ 01068 arp_table[i].q = new_entry; 01069 } 01070 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: queued packet %p on ARP entry %"S16_F"\n", (void *)q, (s16_t)i)); 01071 result = ERR_OK; 01072 } else { 01073 /* the pool MEMP_ARP_QUEUE is empty */ 01074 pbuf_free(p); 01075 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)); 01076 result = ERR_MEM; 01077 } 01078 #else /* ARP_QUEUEING */ 01079 /* always queue one packet per ARP request only, freeing a previously queued packet */ 01080 if (arp_table[i].q != NULL) { 01081 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)); 01082 pbuf_free(arp_table[i].q); 01083 } 01084 arp_table[i].q = p; 01085 result = ERR_OK; 01086 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: queued packet %p on ARP entry %"S16_F"\n", (void *)q, (s16_t)i)); 01087 #endif /* ARP_QUEUEING */ 01088 } else { 01089 ETHARP_STATS_INC(etharp.memerr); 01090 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)); 01091 result = ERR_MEM; 01092 } 01093 } 01094 return result; 01095 } 01096 01097 /** 01098 * Send a raw ARP packet (opcode and all addresses can be modified) 01099 * 01100 * @param netif the lwip network interface on which to send the ARP packet 01101 * @param ethsrc_addr the source MAC address for the ethernet header 01102 * @param ethdst_addr the destination MAC address for the ethernet header 01103 * @param hwsrc_addr the source MAC address for the ARP protocol header 01104 * @param ipsrc_addr the source IP address for the ARP protocol header 01105 * @param hwdst_addr the destination MAC address for the ARP protocol header 01106 * @param ipdst_addr the destination IP address for the ARP protocol header 01107 * @param opcode the type of the ARP packet 01108 * @return ERR_OK if the ARP packet has been sent 01109 * ERR_MEM if the ARP packet couldn't be allocated 01110 * any other err_t on failure 01111 */ 01112 #if !LWIP_AUTOIP 01113 static 01114 #endif /* LWIP_AUTOIP */ 01115 err_t 01116 etharp_raw(struct netif *netif, const struct eth_addr *ethsrc_addr, 01117 const struct eth_addr *ethdst_addr, 01118 const struct eth_addr *hwsrc_addr, const ip_addr_t *ipsrc_addr, 01119 const struct eth_addr *hwdst_addr, const ip_addr_t *ipdst_addr, 01120 const u16_t opcode) 01121 { 01122 struct pbuf *p; 01123 err_t result = ERR_OK; 01124 struct eth_hdr *ethhdr; 01125 struct etharp_hdr *hdr; 01126 #if LWIP_AUTOIP 01127 const u8_t * ethdst_hwaddr; 01128 #endif /* LWIP_AUTOIP */ 01129 01130 /* allocate a pbuf for the outgoing ARP request packet */ 01131 p = pbuf_alloc(PBUF_RAW, SIZEOF_ETHARP_PACKET, PBUF_RAM); 01132 /* could allocate a pbuf for an ARP request? */ 01133 if (p == NULL) { 01134 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 01135 ("etharp_raw: could not allocate pbuf for ARP request.\n")); 01136 ETHARP_STATS_INC(etharp.memerr); 01137 return ERR_MEM; 01138 } 01139 LWIP_ASSERT("check that first pbuf can hold struct etharp_hdr", 01140 (p->len >= SIZEOF_ETHARP_PACKET)); 01141 01142 ethhdr = (struct eth_hdr *)p->payload; 01143 hdr = (struct etharp_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR); 01144 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_raw: sending raw ARP packet.\n")); 01145 hdr->opcode = htons(opcode); 01146 01147 LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!", 01148 (netif->hwaddr_len == ETHARP_HWADDR_LEN)); 01149 #if LWIP_AUTOIP 01150 /* If we are using Link-Local, all ARP packets that contain a Link-Local 01151 * 'sender IP address' MUST be sent using link-layer broadcast instead of 01152 * link-layer unicast. (See RFC3927 Section 2.5, last paragraph) */ 01153 ethdst_hwaddr = ip_addr_islinklocal(ipsrc_addr) ? (u8_t*)(ethbroadcast.addr) : ethdst_addr->addr; 01154 #endif /* LWIP_AUTOIP */ 01155 /* Write the ARP MAC-Addresses */ 01156 ETHADDR16_COPY(&hdr->shwaddr, hwsrc_addr); 01157 ETHADDR16_COPY(&hdr->dhwaddr, hwdst_addr); 01158 /* Write the Ethernet MAC-Addresses */ 01159 #if LWIP_AUTOIP 01160 ETHADDR16_COPY(ðhdr->dest, ethdst_hwaddr); 01161 #else /* LWIP_AUTOIP */ 01162 ETHADDR16_COPY(ðhdr->dest, ethdst_addr); 01163 #endif /* LWIP_AUTOIP */ 01164 ETHADDR16_COPY(ðhdr->src, ethsrc_addr); 01165 /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without 01166 * structure packing. */ 01167 IPADDR2_COPY(&hdr->sipaddr, ipsrc_addr); 01168 IPADDR2_COPY(&hdr->dipaddr, ipdst_addr); 01169 01170 hdr->hwtype = PP_HTONS(HWTYPE_ETHERNET); 01171 hdr->proto = PP_HTONS(ETHTYPE_IP); 01172 /* set hwlen and protolen */ 01173 hdr->hwlen = ETHARP_HWADDR_LEN; 01174 hdr->protolen = sizeof(ip_addr_t); 01175 01176 ethhdr->type = PP_HTONS(ETHTYPE_ARP); 01177 /* send ARP query */ 01178 result = netif->linkoutput(netif, p); 01179 ETHARP_STATS_INC(etharp.xmit); 01180 /* free ARP query packet */ 01181 pbuf_free(p); 01182 p = NULL; 01183 /* could not allocate pbuf for ARP request */ 01184 01185 return result; 01186 } 01187 01188 /** 01189 * Send an ARP request packet asking for ipaddr. 01190 * 01191 * @param netif the lwip network interface on which to send the request 01192 * @param ipaddr the IP address for which to ask 01193 * @return ERR_OK if the request has been sent 01194 * ERR_MEM if the ARP packet couldn't be allocated 01195 * any other err_t on failure 01196 */ 01197 err_t 01198 etharp_request(struct netif *netif, ip_addr_t *ipaddr) 01199 { 01200 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_request: sending ARP request.\n")); 01201 return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, ðbroadcast, 01202 (struct eth_addr *)netif->hwaddr, &netif->ip_addr, ðzero, 01203 ipaddr, ARP_REQUEST); 01204 } 01205 #endif /* LWIP_ARP */ 01206 01207 /** 01208 * Process received ethernet frames. Using this function instead of directly 01209 * calling ip_input and passing ARP frames through etharp in ethernetif_input, 01210 * the ARP cache is protected from concurrent access. 01211 * 01212 * @param p the recevied packet, p->payload pointing to the ethernet header 01213 * @param netif the network interface on which the packet was received 01214 */ 01215 err_t 01216 ethernet_input(struct pbuf *p, struct netif *netif) 01217 { 01218 struct eth_hdr* ethhdr; 01219 u16_t type; 01220 s16_t ip_hdr_offset = SIZEOF_ETH_HDR; 01221 01222 if (p->len <= SIZEOF_ETH_HDR) { 01223 /* a packet with only an ethernet header (or less) is not valid for us */ 01224 ETHARP_STATS_INC(etharp.proterr); 01225 ETHARP_STATS_INC(etharp.drop); 01226 goto free_and_return; 01227 } 01228 01229 /* points to packet payload, which starts with an Ethernet header */ 01230 ethhdr = (struct eth_hdr *)p->payload; 01231 LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, 01232 ("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", 01233 (unsigned)ethhdr->dest.addr[0], (unsigned)ethhdr->dest.addr[1], (unsigned)ethhdr->dest.addr[2], 01234 (unsigned)ethhdr->dest.addr[3], (unsigned)ethhdr->dest.addr[4], (unsigned)ethhdr->dest.addr[5], 01235 (unsigned)ethhdr->src.addr[0], (unsigned)ethhdr->src.addr[1], (unsigned)ethhdr->src.addr[2], 01236 (unsigned)ethhdr->src.addr[3], (unsigned)ethhdr->src.addr[4], (unsigned)ethhdr->src.addr[5], 01237 (unsigned)htons(ethhdr->type))); 01238 01239 type = ethhdr->type; 01240 #if ETHARP_SUPPORT_VLAN 01241 if (type == PP_HTONS(ETHTYPE_VLAN)) { 01242 struct eth_vlan_hdr *vlan = (struct eth_vlan_hdr*)(((char*)ethhdr) + SIZEOF_ETH_HDR); 01243 if (p->len <= SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR) { 01244 /* a packet with only an ethernet/vlan header (or less) is not valid for us */ 01245 ETHARP_STATS_INC(etharp.proterr); 01246 ETHARP_STATS_INC(etharp.drop); 01247 goto free_and_return; 01248 } 01249 #ifdef ETHARP_VLAN_CHECK /* if not, allow all VLANs */ 01250 if (VLAN_ID(vlan) != ETHARP_VLAN_CHECK) { 01251 /* silently ignore this packet: not for our VLAN */ 01252 pbuf_free(p); 01253 return ERR_OK; 01254 } 01255 #endif /* ETHARP_VLAN_CHECK */ 01256 type = vlan->tpid; 01257 ip_hdr_offset = SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR; 01258 } 01259 #endif /* ETHARP_SUPPORT_VLAN */ 01260 01261 #if LWIP_ARP_FILTER_NETIF 01262 netif = LWIP_ARP_FILTER_NETIF_FN(p, netif, htons(type)); 01263 #endif /* LWIP_ARP_FILTER_NETIF*/ 01264 01265 switch (type) { 01266 #if LWIP_ARP 01267 /* IP packet? */ 01268 case PP_HTONS(ETHTYPE_IP): 01269 if (!(netif->flags & NETIF_FLAG_ETHARP)) { 01270 goto free_and_return; 01271 } 01272 #if ETHARP_TRUST_IP_MAC 01273 /* update ARP table */ 01274 etharp_ip_input(netif, p); 01275 #endif /* ETHARP_TRUST_IP_MAC */ 01276 /* skip Ethernet header */ 01277 if(pbuf_header(p, -ip_hdr_offset)) { 01278 LWIP_ASSERT("Can't move over header in packet", 0); 01279 goto free_and_return; 01280 } else { 01281 /* pass to IP layer */ 01282 ip_input(p, netif); 01283 } 01284 break; 01285 01286 case PP_HTONS(ETHTYPE_ARP): 01287 if (!(netif->flags & NETIF_FLAG_ETHARP)) { 01288 goto free_and_return; 01289 } 01290 /* pass p to ARP module */ 01291 etharp_arp_input(netif, (struct eth_addr*)(netif->hwaddr), p); 01292 break; 01293 #endif /* LWIP_ARP */ 01294 #if PPPOE_SUPPORT 01295 case PP_HTONS(ETHTYPE_PPPOEDISC): /* PPP Over Ethernet Discovery Stage */ 01296 pppoe_disc_input(netif, p); 01297 break; 01298 01299 case PP_HTONS(ETHTYPE_PPPOE): /* PPP Over Ethernet Session Stage */ 01300 pppoe_data_input(netif, p); 01301 break; 01302 #endif /* PPPOE_SUPPORT */ 01303 01304 default: 01305 ETHARP_STATS_INC(etharp.proterr); 01306 ETHARP_STATS_INC(etharp.drop); 01307 goto free_and_return; 01308 } 01309 01310 /* This means the pbuf is freed or consumed, 01311 so the caller doesn't have to free it again */ 01312 return ERR_OK; 01313 01314 free_and_return: 01315 pbuf_free(p); 01316 return ERR_OK; 01317 } 01318 #endif /* LWIP_ARP || LWIP_ETHERNET */
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