A version of LWIP, provided for backwards compatibility.
Dependents: AA_DemoBoard DemoBoard HelloServerDemo DemoBoard_RangeIndicator ... more
autoip.c
00001 /** 00002 * @file 00003 * AutoIP Automatic LinkLocal IP Configuration 00004 * 00005 */ 00006 00007 /* 00008 * 00009 * Copyright (c) 2007 Dominik Spies <kontakt@dspies.de> 00010 * All rights reserved. 00011 * 00012 * Redistribution and use in source and binary forms, with or without modification, 00013 * are permitted provided that the following conditions are met: 00014 * 00015 * 1. Redistributions of source code must retain the above copyright notice, 00016 * this list of conditions and the following disclaimer. 00017 * 2. Redistributions in binary form must reproduce the above copyright notice, 00018 * this list of conditions and the following disclaimer in the documentation 00019 * and/or other materials provided with the distribution. 00020 * 3. The name of the author may not be used to endorse or promote products 00021 * derived from this software without specific prior written permission. 00022 * 00023 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 00024 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00025 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 00026 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00027 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 00028 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00029 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00030 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 00031 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 00032 * OF SUCH DAMAGE. 00033 * 00034 * Author: Dominik Spies <kontakt@dspies.de> 00035 * 00036 * This is a AutoIP implementation for the lwIP TCP/IP stack. It aims to conform 00037 * with RFC 3927. 00038 * 00039 * 00040 * Please coordinate changes and requests with Dominik Spies 00041 * <kontakt@dspies.de> 00042 */ 00043 00044 /******************************************************************************* 00045 * USAGE: 00046 * 00047 * define LWIP_AUTOIP 1 in your lwipopts.h 00048 * 00049 * If you don't use tcpip.c (so, don't call, you don't call tcpip_init): 00050 * - First, call autoip_init(). 00051 * - call autoip_tmr() all AUTOIP_TMR_INTERVAL msces, 00052 * that should be defined in autoip.h. 00053 * I recommend a value of 100. The value must divide 1000 with a remainder almost 0. 00054 * Possible values are 1000, 500, 333, 250, 200, 166, 142, 125, 111, 100 .... 00055 * 00056 * Without DHCP: 00057 * - Call autoip_start() after netif_add(). 00058 * 00059 * With DHCP: 00060 * - define LWIP_DHCP_AUTOIP_COOP 1 in your lwipopts.h. 00061 * - Configure your DHCP Client. 00062 * 00063 */ 00064 00065 #include "lwip/opt.h" 00066 00067 #if LWIP_AUTOIP /* don't build if not configured for use in lwipopts.h */ 00068 00069 #include "lwip/mem.h" 00070 #include "lwip/udp.h" 00071 #include "lwip/ip_addr.h" 00072 #include "lwip/netif.h" 00073 #include "lwip/autoip.h" 00074 #include "netif/etharp.h" 00075 00076 #include <stdlib.h> 00077 #include <string.h> 00078 00079 /* 169.254.0.0 */ 00080 #define AUTOIP_NET 0xA9FE0000 00081 /* 169.254.1.0 */ 00082 #define AUTOIP_RANGE_START (AUTOIP_NET | 0x0100) 00083 /* 169.254.254.255 */ 00084 #define AUTOIP_RANGE_END (AUTOIP_NET | 0xFEFF) 00085 00086 00087 /** Pseudo random macro based on netif informations. 00088 * You could use "rand()" from the C Library if you define LWIP_AUTOIP_RAND in lwipopts.h */ 00089 #ifndef LWIP_AUTOIP_RAND 00090 #define LWIP_AUTOIP_RAND(netif) ( (((u32_t)((netif->hwaddr[5]) & 0xff) << 24) | \ 00091 ((u32_t)((netif->hwaddr[3]) & 0xff) << 16) | \ 00092 ((u32_t)((netif->hwaddr[2]) & 0xff) << 8) | \ 00093 ((u32_t)((netif->hwaddr[4]) & 0xff))) + \ 00094 (netif->autoip?netif->autoip->tried_llipaddr:0)) 00095 #endif /* LWIP_AUTOIP_RAND */ 00096 00097 /** 00098 * Macro that generates the initial IP address to be tried by AUTOIP. 00099 * If you want to override this, define it to something else in lwipopts.h. 00100 */ 00101 #ifndef LWIP_AUTOIP_CREATE_SEED_ADDR 00102 #define LWIP_AUTOIP_CREATE_SEED_ADDR(netif) \ 00103 (AUTOIP_RANGE_START + ((u32_t)(((u8_t)(netif->hwaddr[4])) | \ 00104 ((u32_t)((u8_t)(netif->hwaddr[5]))) << 8))) 00105 #endif /* LWIP_AUTOIP_CREATE_SEED_ADDR */ 00106 00107 /* static functions */ 00108 static void autoip_handle_arp_conflict(struct netif *netif); 00109 00110 /* creates a pseudo random LL IP-Address for a network interface */ 00111 static void autoip_create_addr(struct netif *netif, struct ip_addr *IPAddr); 00112 00113 /* sends an ARP announce */ 00114 static err_t autoip_arp_announce(struct netif *netif); 00115 00116 /* configure interface for use with current LL IP-Address */ 00117 static err_t autoip_bind(struct netif *netif); 00118 00119 /** 00120 * Initialize this module 00121 */ 00122 void 00123 autoip_init(void) 00124 { 00125 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | 3, ("autoip_init()\n")); 00126 } 00127 00128 /** 00129 * Handle a IP address conflict after an ARP conflict detection 00130 */ 00131 static void 00132 autoip_handle_arp_conflict(struct netif *netif) 00133 { 00134 /* Somehow detect if we are defending or retreating */ 00135 unsigned char defend = 1; /* tbd */ 00136 00137 if(defend) { 00138 if(netif->autoip->lastconflict > 0) { 00139 /* retreat, there was a conflicting ARP in the last 00140 * DEFEND_INTERVAL seconds 00141 */ 00142 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 1, 00143 ("autoip_handle_arp_conflict(): we are defending, but in DEFEND_INTERVAL, retreating\n")); 00144 00145 /* TODO: close all TCP sessions */ 00146 autoip_start(netif); 00147 } else { 00148 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 1, 00149 ("autoip_handle_arp_conflict(): we are defend, send ARP Announce\n")); 00150 autoip_arp_announce(netif); 00151 netif->autoip->lastconflict = DEFEND_INTERVAL * AUTOIP_TICKS_PER_SECOND; 00152 } 00153 } else { 00154 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 1, 00155 ("autoip_handle_arp_conflict(): we do not defend, retreating\n")); 00156 /* TODO: close all TCP sessions */ 00157 autoip_start(netif); 00158 } 00159 } 00160 00161 /** 00162 * Create an IP-Address out of range 169.254.1.0 to 169.254.254.255 00163 * 00164 * @param netif network interface on which create the IP-Address 00165 * @param IPAddr ip address to initialize 00166 */ 00167 static void 00168 autoip_create_addr(struct netif *netif, struct ip_addr *IPAddr) 00169 { 00170 /* Here we create an IP-Address out of range 169.254.1.0 to 169.254.254.255 00171 * compliant to RFC 3927 Section 2.1 00172 * We have 254 * 256 possibilities */ 00173 00174 u32_t addr = ntohl(LWIP_AUTOIP_CREATE_SEED_ADDR(netif)); 00175 addr += netif->autoip->tried_llipaddr; 00176 addr = AUTOIP_NET | (addr & 0xffff); 00177 /* Now, 169.254.0.0 <= addr <= 169.254.255.255 */ 00178 00179 if (addr < AUTOIP_RANGE_START) { 00180 addr += AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1; 00181 } 00182 if (addr > AUTOIP_RANGE_END) { 00183 addr -= AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1; 00184 } 00185 LWIP_ASSERT("AUTOIP address not in range", (addr >= AUTOIP_RANGE_START) && 00186 (addr <= AUTOIP_RANGE_END)); 00187 IPAddr->addr = htonl(addr); 00188 00189 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 1, 00190 ("autoip_create_addr(): tried_llipaddr=%"U16_F", 0x%08"X32_F"\n", 00191 (u16_t)(netif->autoip->tried_llipaddr), (u32_t)(IPAddr->addr))); 00192 } 00193 00194 /** 00195 * Sends an ARP announce from a network interface 00196 * 00197 * @param netif network interface used to send the announce 00198 */ 00199 static err_t 00200 autoip_arp_announce(struct netif *netif) 00201 { 00202 return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, ðbroadcast, 00203 (struct eth_addr *)netif->hwaddr, &netif->autoip->llipaddr, ðzero, 00204 &netif->autoip->llipaddr, ARP_REQUEST); 00205 } 00206 00207 /** 00208 * Configure interface for use with current LL IP-Address 00209 * 00210 * @param netif network interface to configure with current LL IP-Address 00211 */ 00212 static err_t 00213 autoip_bind(struct netif *netif) 00214 { 00215 struct autoip *autoip = netif->autoip; 00216 struct ip_addr sn_mask, gw_addr; 00217 00218 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | 3, 00219 ("autoip_bind(netif=%p) %c%c%"U16_F" 0x%08"X32_F"\n", 00220 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num, autoip->llipaddr.addr)); 00221 00222 IP4_ADDR(&sn_mask, 255, 255, 0, 0); 00223 IP4_ADDR(&gw_addr, 0, 0, 0, 0); 00224 00225 netif_set_ipaddr(netif, &autoip->llipaddr); 00226 netif_set_netmask(netif, &sn_mask); 00227 netif_set_gw(netif, &gw_addr); 00228 00229 /* bring the interface up */ 00230 netif_set_up(netif); 00231 00232 return ERR_OK; 00233 } 00234 00235 /** 00236 * Start AutoIP client 00237 * 00238 * @param netif network interface on which start the AutoIP client 00239 */ 00240 err_t 00241 autoip_start(struct netif *netif) 00242 { 00243 struct autoip *autoip = netif->autoip; 00244 err_t result = ERR_OK; 00245 00246 if(netif_is_up(netif)) { 00247 netif_set_down(netif); 00248 } 00249 00250 /* Set IP-Address, Netmask and Gateway to 0 to make sure that 00251 * ARP Packets are formed correctly 00252 */ 00253 netif->ip_addr.addr = 0; 00254 netif->netmask.addr = 0; 00255 netif->gw.addr = 0; 00256 00257 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, 00258 ("autoip_start(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0], 00259 netif->name[1], (u16_t)netif->num)); 00260 if(autoip == NULL) { 00261 /* no AutoIP client attached yet? */ 00262 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, 00263 ("autoip_start(): starting new AUTOIP client\n")); 00264 autoip = (struct autoip *)mem_malloc(sizeof(struct autoip)); // static_cast<struct autoip *>(x) 00265 if(autoip == NULL) { 00266 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, 00267 ("autoip_start(): could not allocate autoip\n")); 00268 return ERR_MEM; 00269 } 00270 memset( autoip, 0, sizeof(struct autoip)); 00271 /* store this AutoIP client in the netif */ 00272 netif->autoip = autoip; 00273 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_start(): allocated autoip")); 00274 } else { 00275 autoip->state = AUTOIP_STATE_OFF; 00276 autoip->ttw = 0; 00277 autoip->sent_num = 0; 00278 memset(&autoip->llipaddr, 0, sizeof(struct ip_addr)); 00279 autoip->lastconflict = 0; 00280 } 00281 00282 autoip_create_addr(netif, &(autoip->llipaddr)); 00283 autoip->tried_llipaddr++; 00284 autoip->state = AUTOIP_STATE_PROBING; 00285 autoip->sent_num = 0; 00286 00287 /* time to wait to first probe, this is randomly 00288 * choosen out of 0 to PROBE_WAIT seconds. 00289 * compliant to RFC 3927 Section 2.2.1 00290 */ 00291 autoip->ttw = (u16_t)(LWIP_AUTOIP_RAND(netif) % (PROBE_WAIT * AUTOIP_TICKS_PER_SECOND)); 00292 00293 /* 00294 * if we tried more then MAX_CONFLICTS we must limit our rate for 00295 * accquiring and probing address 00296 * compliant to RFC 3927 Section 2.2.1 00297 */ 00298 00299 if(autoip->tried_llipaddr > MAX_CONFLICTS) { 00300 autoip->ttw = RATE_LIMIT_INTERVAL * AUTOIP_TICKS_PER_SECOND; 00301 } 00302 00303 return result; 00304 } 00305 00306 /** 00307 * Stop AutoIP client 00308 * 00309 * @param netif network interface on which stop the AutoIP client 00310 */ 00311 err_t 00312 autoip_stop(struct netif *netif) 00313 { 00314 netif->autoip->state = AUTOIP_STATE_OFF; 00315 netif_set_down(netif); 00316 return ERR_OK; 00317 } 00318 00319 /** 00320 * Has to be called in loop every AUTOIP_TMR_INTERVAL milliseconds 00321 */ 00322 void 00323 autoip_tmr() 00324 { 00325 struct netif *netif = netif_list; 00326 /* loop through netif's */ 00327 while (netif != NULL) { 00328 /* only act on AutoIP configured interfaces */ 00329 if (netif->autoip != NULL) { 00330 if(netif->autoip->lastconflict > 0) { 00331 netif->autoip->lastconflict--; 00332 } 00333 00334 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, 00335 ("autoip_tmr() AutoIP-State: %"U16_F", ttw=%"U16_F"\n", 00336 (u16_t)(netif->autoip->state), netif->autoip->ttw)); 00337 00338 switch(netif->autoip->state) { 00339 case AUTOIP_STATE_PROBING: 00340 if(netif->autoip->ttw > 0) { 00341 netif->autoip->ttw--; 00342 } else { 00343 if(netif->autoip->sent_num == PROBE_NUM) { 00344 netif->autoip->state = AUTOIP_STATE_ANNOUNCING; 00345 netif->autoip->sent_num = 0; 00346 netif->autoip->ttw = ANNOUNCE_WAIT * AUTOIP_TICKS_PER_SECOND; 00347 } else { 00348 etharp_request(netif, &(netif->autoip->llipaddr)); 00349 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | 3, 00350 ("autoip_tmr() PROBING Sent Probe\n")); 00351 netif->autoip->sent_num++; 00352 /* calculate time to wait to next probe */ 00353 netif->autoip->ttw = (u16_t)((LWIP_AUTOIP_RAND(netif) % 00354 ((PROBE_MAX - PROBE_MIN) * AUTOIP_TICKS_PER_SECOND) ) + 00355 PROBE_MIN * AUTOIP_TICKS_PER_SECOND); 00356 } 00357 } 00358 break; 00359 00360 case AUTOIP_STATE_ANNOUNCING: 00361 if(netif->autoip->ttw > 0) { 00362 netif->autoip->ttw--; 00363 } else { 00364 if(netif->autoip->sent_num == 0) { 00365 /* We are here the first time, so we waited ANNOUNCE_WAIT seconds 00366 * Now we can bind to an IP address and use it 00367 */ 00368 autoip_bind(netif); 00369 } 00370 00371 if(netif->autoip->sent_num == ANNOUNCE_NUM) { 00372 netif->autoip->state = AUTOIP_STATE_BOUND; 00373 netif->autoip->sent_num = 0; 00374 netif->autoip->ttw = 0; 00375 } else { 00376 autoip_arp_announce(netif); 00377 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | 3, 00378 ("autoip_tmr() ANNOUNCING Sent Announce\n")); 00379 netif->autoip->sent_num++; 00380 netif->autoip->ttw = ANNOUNCE_INTERVAL * AUTOIP_TICKS_PER_SECOND; 00381 } 00382 } 00383 break; 00384 } 00385 } 00386 /* proceed to next network interface */ 00387 netif = netif->next; 00388 } 00389 } 00390 00391 /** 00392 * Handles every incoming ARP Packet, called by etharp_arp_input. 00393 * 00394 * @param netif network interface to use for autoip processing 00395 * @param hdr Incoming ARP packet 00396 */ 00397 void 00398 autoip_arp_reply(struct netif *netif, struct etharp_hdr *hdr) 00399 { 00400 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | 3, ("autoip_arp_reply()\n")); 00401 if ((netif->autoip != NULL) && (netif->autoip->state != AUTOIP_STATE_OFF)) { 00402 /* when ip.src == llipaddr && hw.src != netif->hwaddr 00403 * 00404 * when probing ip.dst == llipaddr && hw.src != netif->hwaddr 00405 * we have a conflict and must solve it 00406 */ 00407 struct ip_addr sipaddr, dipaddr; 00408 struct eth_addr netifaddr; 00409 netifaddr.addr[0] = netif->hwaddr[0]; 00410 netifaddr.addr[1] = netif->hwaddr[1]; 00411 netifaddr.addr[2] = netif->hwaddr[2]; 00412 netifaddr.addr[3] = netif->hwaddr[3]; 00413 netifaddr.addr[4] = netif->hwaddr[4]; 00414 netifaddr.addr[5] = netif->hwaddr[5]; 00415 00416 /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without 00417 * structure packing (not using structure copy which breaks strict-aliasing rules). 00418 */ 00419 SMEMCPY(&sipaddr, &hdr->sipaddr, sizeof(sipaddr)); 00420 SMEMCPY(&dipaddr, &hdr->dipaddr, sizeof(dipaddr)); 00421 00422 if ((netif->autoip->state == AUTOIP_STATE_PROBING) || 00423 ((netif->autoip->state == AUTOIP_STATE_ANNOUNCING) && 00424 (netif->autoip->sent_num == 0))) { 00425 /* RFC 3927 Section 2.2.1: 00426 * from beginning to after ANNOUNCE_WAIT 00427 * seconds we have a conflict if 00428 * ip.src == llipaddr OR 00429 * ip.dst == llipaddr && hw.src != own hwaddr 00430 */ 00431 if ((ip_addr_cmp(&sipaddr, &netif->autoip->llipaddr)) || 00432 (ip_addr_cmp(&dipaddr, &netif->autoip->llipaddr) && 00433 !eth_addr_cmp(&netifaddr, &hdr->shwaddr))) { 00434 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 1, 00435 ("autoip_arp_reply(): Probe Conflict detected\n")); 00436 autoip_start(netif); 00437 } 00438 } else { 00439 /* RFC 3927 Section 2.5: 00440 * in any state we have a conflict if 00441 * ip.src == llipaddr && hw.src != own hwaddr 00442 */ 00443 if (ip_addr_cmp(&sipaddr, &netif->autoip->llipaddr) && 00444 !eth_addr_cmp(&netifaddr, &hdr->shwaddr)) { 00445 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 1, 00446 ("autoip_arp_reply(): Conflicting ARP-Packet detected\n")); 00447 autoip_handle_arp_conflict(netif); 00448 } 00449 } 00450 } 00451 } 00452 00453 #endif /* LWIP_AUTOIP */
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