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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 <kontakt@dspies.de>
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 <kontakt@dspies.de>
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_CORE_LOCKED();
109   LWIP_ASSERT("netif != NULL", netif != NULL);
110   LWIP_ASSERT("autoip != NULL", autoip != NULL);
111   LWIP_ASSERT("netif already has a struct autoip set",
112               netif_autoip_data(netif) == NULL);
113 
114   /* clear data structure */
115   memset(autoip, 0, sizeof(struct autoip));
116   /* autoip->state = AUTOIP_STATE_OFF; */
117   netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_AUTOIP, autoip);
118 }
119 
120 /** Restart AutoIP client and check the next address (conflict detected)
121  *
122  * @param netif The netif under AutoIP control
123  */
124 static void
autoip_restart(struct netif * netif)125 autoip_restart(struct netif *netif)
126 {
127   struct autoip *autoip = netif_autoip_data(netif);
128   autoip->tried_llipaddr++;
129   autoip_start(netif);
130 }
131 
132 /**
133  * Handle a IP address conflict after an ARP conflict detection
134  */
135 static void
autoip_handle_arp_conflict(struct netif * netif)136 autoip_handle_arp_conflict(struct netif *netif)
137 {
138   struct autoip *autoip = netif_autoip_data(netif);
139 
140   /* RFC3927, 2.5 "Conflict Detection and Defense" allows two options where
141      a) means retreat on the first conflict and
142      b) allows to keep an already configured address when having only one
143         conflict in 10 seconds
144      We use option b) since it helps to improve the chance that one of the two
145      conflicting hosts may be able to retain its address. */
146 
147   if (autoip->lastconflict > 0) {
148     /* retreat, there was a conflicting ARP in the last DEFEND_INTERVAL seconds */
149     LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
150                 ("autoip_handle_arp_conflict(): we are defending, but in DEFEND_INTERVAL, retreating\n"));
151 
152     /* Active TCP sessions are aborted when removing the ip addresss */
153     autoip_restart(netif);
154   } else {
155     LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
156                 ("autoip_handle_arp_conflict(): we are defend, send ARP Announce\n"));
157     autoip_arp_announce(netif);
158     autoip->lastconflict = DEFEND_INTERVAL * AUTOIP_TICKS_PER_SECOND;
159   }
160 }
161 
162 /**
163  * Create an IP-Address out of range 169.254.1.0 to 169.254.254.255
164  *
165  * @param netif network interface on which create the IP-Address
166  * @param ipaddr ip address to initialize
167  */
168 static void
autoip_create_addr(struct netif * netif,ip4_addr_t * ipaddr)169 autoip_create_addr(struct netif *netif, ip4_addr_t *ipaddr)
170 {
171   struct autoip *autoip = netif_autoip_data(netif);
172 
173   /* Here we create an IP-Address out of range 169.254.1.0 to 169.254.254.255
174    * compliant to RFC 3927 Section 2.1
175    * We have 254 * 256 possibilities */
176 
177   u32_t addr = lwip_ntohl(LWIP_AUTOIP_CREATE_SEED_ADDR(netif));
178   addr += autoip->tried_llipaddr;
179   addr = AUTOIP_NET | (addr & 0xffff);
180   /* Now, 169.254.0.0 <= addr <= 169.254.255.255 */
181 
182   if (addr < AUTOIP_RANGE_START) {
183     addr += AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1;
184   }
185   if (addr > AUTOIP_RANGE_END) {
186     addr -= AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1;
187   }
188   LWIP_ASSERT("AUTOIP address not in range", (addr >= AUTOIP_RANGE_START) &&
189               (addr <= AUTOIP_RANGE_END));
190   ip4_addr_set_u32(ipaddr, lwip_htonl(addr));
191 
192   LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
193               ("autoip_create_addr(): tried_llipaddr=%"U16_F", %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
194                (u16_t)(autoip->tried_llipaddr), ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr),
195                ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr)));
196 }
197 
198 /**
199  * Sends an ARP probe from a network interface
200  *
201  * @param netif network interface used to send the probe
202  */
203 static err_t
autoip_arp_probe(struct netif * netif)204 autoip_arp_probe(struct netif *netif)
205 {
206   struct autoip *autoip = netif_autoip_data(netif);
207   /* this works because netif->ip_addr is ANY */
208   return etharp_request(netif, &autoip->llipaddr);
209 }
210 
211 /**
212  * Sends an ARP announce from a network interface
213  *
214  * @param netif network interface used to send the announce
215  */
216 static err_t
autoip_arp_announce(struct netif * netif)217 autoip_arp_announce(struct netif *netif)
218 {
219   return etharp_gratuitous(netif);
220 }
221 
222 /**
223  * Configure interface for use with current LL IP-Address
224  *
225  * @param netif network interface to configure with current LL IP-Address
226  */
227 static err_t
autoip_bind(struct netif * netif)228 autoip_bind(struct netif *netif)
229 {
230   struct autoip *autoip = netif_autoip_data(netif);
231   ip4_addr_t sn_mask, gw_addr;
232 
233   LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
234               ("autoip_bind(netif=%p) %c%c%"U16_F" %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
235                (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num,
236                ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
237                ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
238 
239   IP4_ADDR(&sn_mask, 255, 255, 0, 0);
240   IP4_ADDR(&gw_addr, 0, 0, 0, 0);
241 
242   netif_set_addr(netif, &autoip->llipaddr, &sn_mask, &gw_addr);
243   /* interface is used by routing now that an address is set */
244 
245   return ERR_OK;
246 }
247 
248 /**
249  * @ingroup autoip
250  * Start AutoIP client
251  *
252  * @param netif network interface on which start the AutoIP client
253  */
254 err_t
autoip_start(struct netif * netif)255 autoip_start(struct netif *netif)
256 {
257   struct autoip *autoip = netif_autoip_data(netif);
258   err_t result = ERR_OK;
259 
260   LWIP_ASSERT_CORE_LOCKED();
261   LWIP_ERROR("netif is not up, old style port?", netif_is_up(netif), return ERR_ARG;);
262 
263   /* Set IP-Address, Netmask and Gateway to 0 to make sure that
264    * ARP Packets are formed correctly
265    */
266   netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4);
267 
268   LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
269               ("autoip_start(netif=%p) %c%c%"U16_F"\n", (void *)netif, netif->name[0],
270                netif->name[1], (u16_t)netif->num));
271   if (autoip == NULL) {
272     /* no AutoIP client attached yet? */
273     LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
274                 ("autoip_start(): starting new AUTOIP client\n"));
275     autoip = (struct autoip *)mem_calloc(1, sizeof(struct autoip));
276     if (autoip == NULL) {
277       LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
278                   ("autoip_start(): could not allocate autoip\n"));
279       return ERR_MEM;
280     }
281     /* store this AutoIP client in the netif */
282     netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_AUTOIP, autoip);
283     LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_start(): allocated autoip"));
284   } else {
285     autoip->state = AUTOIP_STATE_OFF;
286     autoip->ttw = 0;
287     autoip->sent_num = 0;
288     ip4_addr_set_zero(&autoip->llipaddr);
289     autoip->lastconflict = 0;
290   }
291 
292   autoip_create_addr(netif, &(autoip->llipaddr));
293   autoip_start_probing(netif);
294 
295   return result;
296 }
297 
298 static void
autoip_start_probing(struct netif * netif)299 autoip_start_probing(struct netif *netif)
300 {
301   struct autoip *autoip = netif_autoip_data(netif);
302 
303   autoip->state = AUTOIP_STATE_PROBING;
304   autoip->sent_num = 0;
305   LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
306               ("autoip_start_probing(): changing state to PROBING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
307                ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
308                ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
309 
310   /* time to wait to first probe, this is randomly
311    * chosen out of 0 to PROBE_WAIT seconds.
312    * compliant to RFC 3927 Section 2.2.1
313    */
314   autoip->ttw = (u16_t)(LWIP_AUTOIP_RAND(netif) % (PROBE_WAIT * AUTOIP_TICKS_PER_SECOND));
315 
316   /*
317    * if we tried more then MAX_CONFLICTS we must limit our rate for
318    * acquiring and probing address
319    * compliant to RFC 3927 Section 2.2.1
320    */
321   if (autoip->tried_llipaddr > MAX_CONFLICTS) {
322     autoip->ttw = RATE_LIMIT_INTERVAL * AUTOIP_TICKS_PER_SECOND;
323   }
324 }
325 
326 /**
327  * Handle a possible change in the network configuration.
328  *
329  * If there is an AutoIP address configured, take the interface down
330  * and begin probing with the same address.
331  */
332 void
autoip_network_changed(struct netif * netif)333 autoip_network_changed(struct netif *netif)
334 {
335   struct autoip *autoip = netif_autoip_data(netif);
336 
337   if (autoip && (autoip->state != AUTOIP_STATE_OFF)) {
338     autoip_start_probing(netif);
339   }
340 }
341 
342 /**
343  * @ingroup autoip
344  * Stop AutoIP client
345  *
346  * @param netif network interface on which stop the AutoIP client
347  */
348 err_t
autoip_stop(struct netif * netif)349 autoip_stop(struct netif *netif)
350 {
351   struct autoip *autoip = netif_autoip_data(netif);
352 
353   LWIP_ASSERT_CORE_LOCKED();
354   if (autoip != NULL) {
355     autoip->state = AUTOIP_STATE_OFF;
356     if (ip4_addr_islinklocal(netif_ip4_addr(netif))) {
357       netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4);
358     }
359   }
360   return ERR_OK;
361 }
362 
363 #if LWIP_LOWPOWER
364 #include "lwip/lowpower.h"
365 u32_t
autoip_tmr_tick(void)366 autoip_tmr_tick(void)
367 {
368   struct netif *netif = NULL;
369   u32_t tick = 0;
370   NETIF_FOREACH(netif) {
371     struct autoip *autoip = netif_autoip_data(netif);
372     if ((autoip != NULL) && (autoip->ttw > 0)) {
373       if ((autoip->state == AUTOIP_STATE_PROBING) ||
374           (autoip->state == AUTOIP_STATE_ANNOUNCING)) {
375         SET_TMR_TICK(tick, autoip->ttw);
376       }
377     }
378   }
379 
380   LWIP_DEBUGF(LOWPOWER_DEBUG, ("%s tmr tick: %u\n", "autoip_tmr_tick", tick));
381   return tick;
382 }
383 
384 #endif
385 
386 /**
387  * Has to be called in loop every AUTOIP_TMR_INTERVAL milliseconds
388  */
389 void
autoip_tmr(void)390 autoip_tmr(void)
391 {
392   struct netif *netif;
393   /* loop through netif's */
394   NETIF_FOREACH(netif) {
395     struct autoip *autoip = netif_autoip_data(netif);
396     /* only act on AutoIP configured interfaces */
397     if (autoip != NULL) {
398       if (autoip->lastconflict > 0) {
399         autoip->lastconflict--;
400       }
401 
402       LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
403                   ("autoip_tmr() AutoIP-State: %"U16_F", ttw=%"U16_F"\n",
404                    (u16_t)(autoip->state), autoip->ttw));
405 
406       if (autoip->ttw > 0) {
407         autoip->ttw--;
408       }
409 
410       switch (autoip->state) {
411         case AUTOIP_STATE_PROBING:
412           if (autoip->ttw == 0) {
413             if (autoip->sent_num >= PROBE_NUM) {
414               /* Switch to ANNOUNCING: now we can bind to an IP address and use it */
415               autoip->state = AUTOIP_STATE_ANNOUNCING;
416               autoip_bind(netif);
417               /* autoip_bind() calls netif_set_addr(): this triggers a gratuitous ARP
418                  which counts as an announcement */
419               autoip->sent_num = 1;
420               autoip->ttw = ANNOUNCE_WAIT * AUTOIP_TICKS_PER_SECOND;
421               LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
422                           ("autoip_tmr(): changing state to ANNOUNCING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
423                            ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
424                            ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
425             } else {
426               autoip_arp_probe(netif);
427               LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_tmr() PROBING Sent Probe\n"));
428               autoip->sent_num++;
429               if (autoip->sent_num == PROBE_NUM) {
430                 /* calculate time to wait to for announce */
431                 autoip->ttw = ANNOUNCE_WAIT * AUTOIP_TICKS_PER_SECOND;
432               } else {
433                 /* calculate time to wait to next probe */
434                 autoip->ttw = (u16_t)((LWIP_AUTOIP_RAND(netif) %
435                                        ((PROBE_MAX - PROBE_MIN) * AUTOIP_TICKS_PER_SECOND) ) +
436                                       PROBE_MIN * AUTOIP_TICKS_PER_SECOND);
437               }
438             }
439           }
440           break;
441 
442         case AUTOIP_STATE_ANNOUNCING:
443           if (autoip->ttw == 0) {
444             autoip_arp_announce(netif);
445             LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_tmr() ANNOUNCING Sent Announce\n"));
446             autoip->ttw = ANNOUNCE_INTERVAL * AUTOIP_TICKS_PER_SECOND;
447             autoip->sent_num++;
448 
449             if (autoip->sent_num >= ANNOUNCE_NUM) {
450               autoip->state = AUTOIP_STATE_BOUND;
451               autoip->sent_num = 0;
452               autoip->ttw = 0;
453               LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
454                           ("autoip_tmr(): changing state to BOUND: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
455                            ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
456                            ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
457             }
458           }
459           break;
460 
461         default:
462           /* nothing to do in other states */
463           break;
464       }
465     }
466   }
467 }
468 
469 /**
470  * Handles every incoming ARP Packet, called by etharp_input().
471  *
472  * @param netif network interface to use for autoip processing
473  * @param hdr Incoming ARP packet
474  */
475 void
autoip_arp_reply(struct netif * netif,struct etharp_hdr * hdr)476 autoip_arp_reply(struct netif *netif, struct etharp_hdr *hdr)
477 {
478   struct autoip *autoip = netif_autoip_data(netif);
479 
480   LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_arp_reply()\n"));
481   if ((autoip != NULL) && (autoip->state != AUTOIP_STATE_OFF)) {
482     /* when ip.src == llipaddr && hw.src != netif->hwaddr
483      *
484      * when probing  ip.dst == llipaddr && hw.src != netif->hwaddr
485      * we have a conflict and must solve it
486      */
487     ip4_addr_t sipaddr, dipaddr;
488     struct eth_addr netifaddr;
489     SMEMCPY(netifaddr.addr, netif->hwaddr, ETH_HWADDR_LEN);
490 
491     /* Copy struct ip4_addr_wordaligned to aligned ip4_addr, to support compilers without
492      * structure packing (not using structure copy which breaks strict-aliasing rules).
493      */
494     IPADDR_WORDALIGNED_COPY_TO_IP4_ADDR_T(&sipaddr, &hdr->sipaddr);
495     IPADDR_WORDALIGNED_COPY_TO_IP4_ADDR_T(&dipaddr, &hdr->dipaddr);
496 
497     if (autoip->state == AUTOIP_STATE_PROBING) {
498       /* RFC 3927 Section 2.2.1:
499        * from beginning to after ANNOUNCE_WAIT
500        * seconds we have a conflict if
501        * ip.src == llipaddr OR
502        * ip.dst == llipaddr && hw.src != own hwaddr
503        */
504       if ((ip4_addr_cmp(&sipaddr, &autoip->llipaddr)) ||
505           (ip4_addr_isany_val(sipaddr) &&
506            ip4_addr_cmp(&dipaddr, &autoip->llipaddr) &&
507            !eth_addr_cmp(&netifaddr, &hdr->shwaddr))) {
508         LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
509                     ("autoip_arp_reply(): Probe Conflict detected\n"));
510         autoip_restart(netif);
511       }
512     } else {
513       /* RFC 3927 Section 2.5:
514        * in any state we have a conflict if
515        * ip.src == llipaddr && hw.src != own hwaddr
516        */
517       if (ip4_addr_cmp(&sipaddr, &autoip->llipaddr) &&
518           !eth_addr_cmp(&netifaddr, &hdr->shwaddr)) {
519         LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
520                     ("autoip_arp_reply(): Conflicting ARP-Packet detected\n"));
521         autoip_handle_arp_conflict(netif);
522       }
523     }
524   }
525 }
526 
527 /** check if AutoIP supplied netif->ip_addr
528  *
529  * @param netif the netif to check
530  * @return 1 if AutoIP supplied netif->ip_addr (state BOUND or ANNOUNCING),
531  *         0 otherwise
532  */
533 u8_t
autoip_supplied_address(const struct netif * netif)534 autoip_supplied_address(const struct netif *netif)
535 {
536   if ((netif != NULL) && (netif_autoip_data(netif) != NULL)) {
537     struct autoip *autoip = netif_autoip_data(netif);
538     return (autoip->state == AUTOIP_STATE_BOUND) || (autoip->state == AUTOIP_STATE_ANNOUNCING);
539   }
540   return 0;
541 }
542 
543 u8_t
autoip_accept_packet(struct netif * netif,const ip4_addr_t * addr)544 autoip_accept_packet(struct netif *netif, const ip4_addr_t *addr)
545 {
546   struct autoip *autoip = netif_autoip_data(netif);
547   return (autoip != NULL) && ip4_addr_cmp(addr, &(autoip->llipaddr));
548 }
549 
550 #endif /* LWIP_IPV4 && LWIP_AUTOIP */
551