1 /**
2 * @file
3 * AutoIP Automatic LinkLocal IP Configuration
4 *
5 * This is a AutoIP implementation for the lwIP TCP/IP stack. It aims to conform
6 * with RFC 3927.
7 *
8 * @defgroup autoip AUTOIP
9 * @ingroup ip4
10 * AUTOIP related functions
11 * USAGE:
12 *
13 * define @ref LWIP_AUTOIP 1 in your lwipopts.h
14 * Options:
15 * AUTOIP_TMR_INTERVAL msecs,
16 * I recommend a value of 100. The value must divide 1000 with a remainder almost 0.
17 * Possible values are 1000, 500, 333, 250, 200, 166, 142, 125, 111, 100 ....
18 *
19 * Without DHCP:
20 * - Call autoip_start() after netif_add().
21 *
22 * With DHCP:
23 * - define @ref LWIP_DHCP_AUTOIP_COOP 1 in your lwipopts.h.
24 * - Configure your DHCP Client.
25 *
26 * @see netifapi_autoip
27 */
28
29 /*
30 *
31 * Copyright (c) 2007 Dominik Spies <[email protected]>
32 * All rights reserved.
33 *
34 * Redistribution and use in source and binary forms, with or without modification,
35 * are permitted provided that the following conditions are met:
36 *
37 * 1. Redistributions of source code must retain the above copyright notice,
38 * this list of conditions and the following disclaimer.
39 * 2. Redistributions in binary form must reproduce the above copyright notice,
40 * this list of conditions and the following disclaimer in the documentation
41 * and/or other materials provided with the distribution.
42 * 3. The name of the author may not be used to endorse or promote products
43 * derived from this software without specific prior written permission.
44 *
45 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
46 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
47 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
48 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
49 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
50 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
51 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
52 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
53 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
54 * OF SUCH DAMAGE.
55 *
56 * Author: Dominik Spies <[email protected]>
57 */
58
59 #include "lwip/opt.h"
60
61 #if LWIP_IPV4 && LWIP_AUTOIP /* don't build if not configured for use in lwipopts.h */
62
63 #include "lwip/mem.h"
64 /* #include "lwip/udp.h" */
65 #include "lwip/ip_addr.h"
66 #include "lwip/netif.h"
67 #include "lwip/autoip.h"
68 #include "lwip/etharp.h"
69 #include "lwip/prot/autoip.h"
70
71 #include <string.h>
72
73 /** Pseudo random macro based on netif informations.
74 * You could use "rand()" from the C Library if you define LWIP_AUTOIP_RAND in lwipopts.h */
75 #ifndef LWIP_AUTOIP_RAND
76 #define LWIP_AUTOIP_RAND(netif) ( (((u32_t)((netif->hwaddr[5]) & 0xff) << 24) | \
77 ((u32_t)((netif->hwaddr[3]) & 0xff) << 16) | \
78 ((u32_t)((netif->hwaddr[2]) & 0xff) << 8) | \
79 ((u32_t)((netif->hwaddr[4]) & 0xff))) + \
80 (netif_autoip_data(netif)? netif_autoip_data(netif)->tried_llipaddr : 0))
81 #endif /* LWIP_AUTOIP_RAND */
82
83 /**
84 * Macro that generates the initial IP address to be tried by AUTOIP.
85 * If you want to override this, define it to something else in lwipopts.h.
86 */
87 #ifndef LWIP_AUTOIP_CREATE_SEED_ADDR
88 #define LWIP_AUTOIP_CREATE_SEED_ADDR(netif) \
89 lwip_htonl(AUTOIP_RANGE_START + ((u32_t)(((u8_t)(netif->hwaddr[4])) | \
90 ((u32_t)((u8_t)(netif->hwaddr[5]))) << 8)))
91 #endif /* LWIP_AUTOIP_CREATE_SEED_ADDR */
92
93 /* static functions */
94 static err_t autoip_arp_announce(struct netif *netif);
95 static void autoip_start_probing(struct netif *netif);
96
97 /**
98 * @ingroup autoip
99 * Set a statically allocated struct autoip to work with.
100 * Using this prevents autoip_start to allocate it using mem_malloc.
101 *
102 * @param netif the netif for which to set the struct autoip
103 * @param autoip (uninitialised) autoip struct allocated by the application
104 */
105 void
autoip_set_struct(struct netif * netif,struct autoip * autoip)106 autoip_set_struct(struct netif *netif, struct autoip *autoip)
107 {
108 LWIP_ASSERT("netif != NULL", netif != NULL);
109 LWIP_ASSERT("autoip != NULL", autoip != NULL);
110 LWIP_ASSERT("netif already has a struct autoip set",
111 netif_autoip_data(netif) == NULL);
112
113 /* clear data structure */
114 memset(autoip, 0, sizeof(struct autoip));
115 /* autoip->state = AUTOIP_STATE_OFF; */
116 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_AUTOIP, autoip);
117 }
118
119 /** Restart AutoIP client and check the next address (conflict detected)
120 *
121 * @param netif The netif under AutoIP control
122 */
123 static void
autoip_restart(struct netif * netif)124 autoip_restart(struct netif *netif)
125 {
126 struct autoip* autoip = netif_autoip_data(netif);
127 autoip->tried_llipaddr++;
128 autoip_start(netif);
129 }
130
131 /**
132 * Handle a IP address conflict after an ARP conflict detection
133 */
134 static void
autoip_handle_arp_conflict(struct netif * netif)135 autoip_handle_arp_conflict(struct netif *netif)
136 {
137 struct autoip* autoip = netif_autoip_data(netif);
138
139 /* RFC3927, 2.5 "Conflict Detection and Defense" allows two options where
140 a) means retreat on the first conflict and
141 b) allows to keep an already configured address when having only one
142 conflict in 10 seconds
143 We use option b) since it helps to improve the chance that one of the two
144 conflicting hosts may be able to retain its address. */
145
146 if (autoip->lastconflict > 0) {
147 /* retreat, there was a conflicting ARP in the last DEFEND_INTERVAL seconds */
148 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
149 ("autoip_handle_arp_conflict(): we are defending, but in DEFEND_INTERVAL, retreating\n"));
150
151 /* Active TCP sessions are aborted when removing the ip addresss */
152 autoip_restart(netif);
153 } else {
154 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
155 ("autoip_handle_arp_conflict(): we are defend, send ARP Announce\n"));
156 autoip_arp_announce(netif);
157 autoip->lastconflict = DEFEND_INTERVAL * AUTOIP_TICKS_PER_SECOND;
158 }
159 }
160
161 /**
162 * Create an IP-Address out of range 169.254.1.0 to 169.254.254.255
163 *
164 * @param netif network interface on which create the IP-Address
165 * @param ipaddr ip address to initialize
166 */
167 static void
autoip_create_addr(struct netif * netif,ip4_addr_t * ipaddr)168 autoip_create_addr(struct netif *netif, ip4_addr_t *ipaddr)
169 {
170 struct autoip* autoip = netif_autoip_data(netif);
171
172 /* Here we create an IP-Address out of range 169.254.1.0 to 169.254.254.255
173 * compliant to RFC 3927 Section 2.1
174 * We have 254 * 256 possibilities */
175
176 u32_t addr = lwip_ntohl(LWIP_AUTOIP_CREATE_SEED_ADDR(netif));
177 addr += autoip->tried_llipaddr;
178 addr = AUTOIP_NET | (addr & 0xffff);
179 /* Now, 169.254.0.0 <= addr <= 169.254.255.255 */
180
181 if (addr < AUTOIP_RANGE_START) {
182 addr += AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1;
183 }
184 if (addr > AUTOIP_RANGE_END) {
185 addr -= AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1;
186 }
187 LWIP_ASSERT("AUTOIP address not in range", (addr >= AUTOIP_RANGE_START) &&
188 (addr <= AUTOIP_RANGE_END));
189 ip4_addr_set_u32(ipaddr, lwip_htonl(addr));
190
191 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
192 ("autoip_create_addr(): tried_llipaddr=%"U16_F", %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
193 (u16_t)(autoip->tried_llipaddr), ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr),
194 ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr)));
195 }
196
197 /**
198 * Sends an ARP probe from a network interface
199 *
200 * @param netif network interface used to send the probe
201 */
202 static err_t
autoip_arp_probe(struct netif * netif)203 autoip_arp_probe(struct netif *netif)
204 {
205 struct autoip* autoip = netif_autoip_data(netif);
206 /* this works because netif->ip_addr is ANY */
207 return etharp_request(netif, &autoip->llipaddr);
208 }
209
210 /**
211 * Sends an ARP announce from a network interface
212 *
213 * @param netif network interface used to send the announce
214 */
215 static err_t
autoip_arp_announce(struct netif * netif)216 autoip_arp_announce(struct netif *netif)
217 {
218 return etharp_gratuitous(netif);
219 }
220
221 /**
222 * Configure interface for use with current LL IP-Address
223 *
224 * @param netif network interface to configure with current LL IP-Address
225 */
226 static err_t
autoip_bind(struct netif * netif)227 autoip_bind(struct netif *netif)
228 {
229 struct autoip* autoip = netif_autoip_data(netif);
230 ip4_addr_t sn_mask, gw_addr;
231
232 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
233 ("autoip_bind(netif=%p) %c%c%"U16_F" %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
234 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num,
235 ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
236 ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
237
238 IP4_ADDR(&sn_mask, 255, 255, 0, 0);
239 IP4_ADDR(&gw_addr, 0, 0, 0, 0);
240
241 netif_set_addr(netif, &autoip->llipaddr, &sn_mask, &gw_addr);
242 /* interface is used by routing now that an address is set */
243
244 return ERR_OK;
245 }
246
247 /**
248 * @ingroup autoip
249 * Start AutoIP client
250 *
251 * @param netif network interface on which start the AutoIP client
252 */
253 err_t
autoip_start(struct netif * netif)254 autoip_start(struct netif *netif)
255 {
256 struct autoip* autoip = netif_autoip_data(netif);
257 err_t result = ERR_OK;
258
259 LWIP_ERROR("netif is not up, old style port?", netif_is_up(netif), return ERR_ARG;);
260
261 /* Set IP-Address, Netmask and Gateway to 0 to make sure that
262 * ARP Packets are formed correctly
263 */
264 netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4);
265
266 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
267 ("autoip_start(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0],
268 netif->name[1], (u16_t)netif->num));
269 if (autoip == NULL) {
270 /* no AutoIP client attached yet? */
271 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
272 ("autoip_start(): starting new AUTOIP client\n"));
273 autoip = (struct autoip *)mem_malloc(sizeof(struct autoip));
274 if (autoip == NULL) {
275 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
276 ("autoip_start(): could not allocate autoip\n"));
277 return ERR_MEM;
278 }
279 memset(autoip, 0, sizeof(struct autoip));
280 /* store this AutoIP client in the netif */
281 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_AUTOIP, autoip);
282 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_start(): allocated autoip"));
283 } else {
284 autoip->state = AUTOIP_STATE_OFF;
285 autoip->ttw = 0;
286 autoip->sent_num = 0;
287 ip4_addr_set_zero(&autoip->llipaddr);
288 autoip->lastconflict = 0;
289 }
290
291 autoip_create_addr(netif, &(autoip->llipaddr));
292 autoip_start_probing(netif);
293
294 return result;
295 }
296
297 static void
autoip_start_probing(struct netif * netif)298 autoip_start_probing(struct netif *netif)
299 {
300 struct autoip* autoip = netif_autoip_data(netif);
301
302 autoip->state = AUTOIP_STATE_PROBING;
303 autoip->sent_num = 0;
304 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
305 ("autoip_start_probing(): changing state to PROBING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
306 ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
307 ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
308
309 /* time to wait to first probe, this is randomly
310 * chosen out of 0 to PROBE_WAIT seconds.
311 * compliant to RFC 3927 Section 2.2.1
312 */
313 autoip->ttw = (u16_t)(LWIP_AUTOIP_RAND(netif) % (PROBE_WAIT * AUTOIP_TICKS_PER_SECOND));
314
315 /*
316 * if we tried more then MAX_CONFLICTS we must limit our rate for
317 * acquiring and probing address
318 * compliant to RFC 3927 Section 2.2.1
319 */
320 if (autoip->tried_llipaddr > MAX_CONFLICTS) {
321 autoip->ttw = RATE_LIMIT_INTERVAL * AUTOIP_TICKS_PER_SECOND;
322 }
323 }
324
325 /**
326 * Handle a possible change in the network configuration.
327 *
328 * If there is an AutoIP address configured, take the interface down
329 * and begin probing with the same address.
330 */
331 void
autoip_network_changed(struct netif * netif)332 autoip_network_changed(struct netif *netif)
333 {
334 struct autoip* autoip = netif_autoip_data(netif);
335
336 if (autoip && (autoip->state != AUTOIP_STATE_OFF)) {
337 autoip_start_probing(netif);
338 }
339 }
340
341 /**
342 * @ingroup autoip
343 * Stop AutoIP client
344 *
345 * @param netif network interface on which stop the AutoIP client
346 */
347 err_t
autoip_stop(struct netif * netif)348 autoip_stop(struct netif *netif)
349 {
350 struct autoip* autoip = netif_autoip_data(netif);
351
352 if (autoip != NULL) {
353 autoip->state = AUTOIP_STATE_OFF;
354 if (ip4_addr_islinklocal(netif_ip4_addr(netif))) {
355 netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4);
356 }
357 }
358 return ERR_OK;
359 }
360
361 /**
362 * Has to be called in loop every AUTOIP_TMR_INTERVAL milliseconds
363 */
364 void
autoip_tmr(void)365 autoip_tmr(void)
366 {
367 struct netif *netif = netif_list;
368 /* loop through netif's */
369 while (netif != NULL) {
370 struct autoip* autoip = netif_autoip_data(netif);
371 /* only act on AutoIP configured interfaces */
372 if (autoip != NULL) {
373 if (autoip->lastconflict > 0) {
374 autoip->lastconflict--;
375 }
376
377 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
378 ("autoip_tmr() AutoIP-State: %"U16_F", ttw=%"U16_F"\n",
379 (u16_t)(autoip->state), autoip->ttw));
380
381 if (autoip->ttw > 0) {
382 autoip->ttw--;
383 }
384
385 switch(autoip->state) {
386 case AUTOIP_STATE_PROBING:
387 if (autoip->ttw == 0) {
388 if (autoip->sent_num >= PROBE_NUM) {
389 /* Switch to ANNOUNCING: now we can bind to an IP address and use it */
390 autoip->state = AUTOIP_STATE_ANNOUNCING;
391 autoip_bind(netif);
392 /* autoip_bind() calls netif_set_addr(): this triggers a gratuitous ARP
393 which counts as an announcement */
394 autoip->sent_num = 1;
395 autoip->ttw = ANNOUNCE_WAIT * AUTOIP_TICKS_PER_SECOND;
396 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
397 ("autoip_tmr(): changing state to ANNOUNCING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
398 ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
399 ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
400 } else {
401 autoip_arp_probe(netif);
402 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_tmr() PROBING Sent Probe\n"));
403 autoip->sent_num++;
404 if (autoip->sent_num == PROBE_NUM) {
405 /* calculate time to wait to for announce */
406 autoip->ttw = ANNOUNCE_WAIT * AUTOIP_TICKS_PER_SECOND;
407 } else {
408 /* calculate time to wait to next probe */
409 autoip->ttw = (u16_t)((LWIP_AUTOIP_RAND(netif) %
410 ((PROBE_MAX - PROBE_MIN) * AUTOIP_TICKS_PER_SECOND) ) +
411 PROBE_MIN * AUTOIP_TICKS_PER_SECOND);
412 }
413 }
414 }
415 break;
416
417 case AUTOIP_STATE_ANNOUNCING:
418 if (autoip->ttw == 0) {
419 autoip_arp_announce(netif);
420 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_tmr() ANNOUNCING Sent Announce\n"));
421 autoip->ttw = ANNOUNCE_INTERVAL * AUTOIP_TICKS_PER_SECOND;
422 autoip->sent_num++;
423
424 if (autoip->sent_num >= ANNOUNCE_NUM) {
425 autoip->state = AUTOIP_STATE_BOUND;
426 autoip->sent_num = 0;
427 autoip->ttw = 0;
428 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
429 ("autoip_tmr(): changing state to BOUND: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
430 ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
431 ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
432 }
433 }
434 break;
435
436 default:
437 /* nothing to do in other states */
438 break;
439 }
440 }
441 /* proceed to next network interface */
442 netif = netif->next;
443 }
444 }
445
446 /**
447 * Handles every incoming ARP Packet, called by etharp_input().
448 *
449 * @param netif network interface to use for autoip processing
450 * @param hdr Incoming ARP packet
451 */
452 void
autoip_arp_reply(struct netif * netif,struct etharp_hdr * hdr)453 autoip_arp_reply(struct netif *netif, struct etharp_hdr *hdr)
454 {
455 struct autoip* autoip = netif_autoip_data(netif);
456
457 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_arp_reply()\n"));
458 if ((autoip != NULL) && (autoip->state != AUTOIP_STATE_OFF)) {
459 /* when ip.src == llipaddr && hw.src != netif->hwaddr
460 *
461 * when probing ip.dst == llipaddr && hw.src != netif->hwaddr
462 * we have a conflict and must solve it
463 */
464 ip4_addr_t sipaddr, dipaddr;
465 struct eth_addr netifaddr;
466 ETHADDR16_COPY(netifaddr.addr, netif->hwaddr);
467
468 /* Copy struct ip4_addr2 to aligned ip4_addr, to support compilers without
469 * structure packing (not using structure copy which breaks strict-aliasing rules).
470 */
471 IPADDR2_COPY(&sipaddr, &hdr->sipaddr);
472 IPADDR2_COPY(&dipaddr, &hdr->dipaddr);
473
474 if (autoip->state == AUTOIP_STATE_PROBING) {
475 /* RFC 3927 Section 2.2.1:
476 * from beginning to after ANNOUNCE_WAIT
477 * seconds we have a conflict if
478 * ip.src == llipaddr OR
479 * ip.dst == llipaddr && hw.src != own hwaddr
480 */
481 if ((ip4_addr_cmp(&sipaddr, &autoip->llipaddr)) ||
482 (ip4_addr_isany_val(sipaddr) &&
483 ip4_addr_cmp(&dipaddr, &autoip->llipaddr) &&
484 !eth_addr_cmp(&netifaddr, &hdr->shwaddr))) {
485 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
486 ("autoip_arp_reply(): Probe Conflict detected\n"));
487 autoip_restart(netif);
488 }
489 } else {
490 /* RFC 3927 Section 2.5:
491 * in any state we have a conflict if
492 * ip.src == llipaddr && hw.src != own hwaddr
493 */
494 if (ip4_addr_cmp(&sipaddr, &autoip->llipaddr) &&
495 !eth_addr_cmp(&netifaddr, &hdr->shwaddr)) {
496 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
497 ("autoip_arp_reply(): Conflicting ARP-Packet detected\n"));
498 autoip_handle_arp_conflict(netif);
499 }
500 }
501 }
502 }
503
504 /** check if AutoIP supplied netif->ip_addr
505 *
506 * @param netif the netif to check
507 * @return 1 if AutoIP supplied netif->ip_addr (state BOUND or ANNOUNCING),
508 * 0 otherwise
509 */
510 u8_t
autoip_supplied_address(const struct netif * netif)511 autoip_supplied_address(const struct netif *netif)
512 {
513 if ((netif != NULL) && (netif_autoip_data(netif) != NULL)) {
514 struct autoip* autoip = netif_autoip_data(netif);
515 return (autoip->state == AUTOIP_STATE_BOUND) || (autoip->state == AUTOIP_STATE_ANNOUNCING);
516 }
517 return 0;
518 }
519
520 u8_t
autoip_accept_packet(struct netif * netif,const ip4_addr_t * addr)521 autoip_accept_packet(struct netif *netif, const ip4_addr_t *addr)
522 {
523 struct autoip* autoip = netif_autoip_data(netif);
524 return (autoip != NULL) && ip4_addr_cmp(addr, &(autoip->llipaddr));
525 }
526
527 #endif /* LWIP_IPV4 && LWIP_AUTOIP */
528