source: azure_iot_hub_f767zi/trunk/asp_baseplatform/lwip/lwip-2.1.2/src/core/ipv4/autoip.c@ 457

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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 */
94static err_t autoip_arp_announce(struct netif *netif);
95static 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 */
105void
106autoip_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 */
124static void
125autoip_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 */
135static void
136autoip_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 */
168static void
169autoip_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 */
203static err_t
204autoip_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 */
216static err_t
217autoip_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 */
227static err_t
228autoip_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 */
254err_t
255autoip_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
298static void
299autoip_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 */
332void
333autoip_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 */
348err_t
349autoip_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/**
364 * Has to be called in loop every AUTOIP_TMR_INTERVAL milliseconds
365 */
366void
367autoip_tmr(void)
368{
369 struct netif *netif;
370 /* loop through netif's */
371 NETIF_FOREACH(netif) {
372 struct autoip *autoip = netif_autoip_data(netif);
373 /* only act on AutoIP configured interfaces */
374 if (autoip != NULL) {
375 if (autoip->lastconflict > 0) {
376 autoip->lastconflict--;
377 }
378
379 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
380 ("autoip_tmr() AutoIP-State: %"U16_F", ttw=%"U16_F"\n",
381 (u16_t)(autoip->state), autoip->ttw));
382
383 if (autoip->ttw > 0) {
384 autoip->ttw--;
385 }
386
387 switch (autoip->state) {
388 case AUTOIP_STATE_PROBING:
389 if (autoip->ttw == 0) {
390 if (autoip->sent_num >= PROBE_NUM) {
391 /* Switch to ANNOUNCING: now we can bind to an IP address and use it */
392 autoip->state = AUTOIP_STATE_ANNOUNCING;
393 autoip_bind(netif);
394 /* autoip_bind() calls netif_set_addr(): this triggers a gratuitous ARP
395 which counts as an announcement */
396 autoip->sent_num = 1;
397 autoip->ttw = ANNOUNCE_WAIT * AUTOIP_TICKS_PER_SECOND;
398 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
399 ("autoip_tmr(): changing state to ANNOUNCING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
400 ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
401 ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
402 } else {
403 autoip_arp_probe(netif);
404 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_tmr() PROBING Sent Probe\n"));
405 autoip->sent_num++;
406 if (autoip->sent_num == PROBE_NUM) {
407 /* calculate time to wait to for announce */
408 autoip->ttw = ANNOUNCE_WAIT * AUTOIP_TICKS_PER_SECOND;
409 } else {
410 /* calculate time to wait to next probe */
411 autoip->ttw = (u16_t)((LWIP_AUTOIP_RAND(netif) %
412 ((PROBE_MAX - PROBE_MIN) * AUTOIP_TICKS_PER_SECOND) ) +
413 PROBE_MIN * AUTOIP_TICKS_PER_SECOND);
414 }
415 }
416 }
417 break;
418
419 case AUTOIP_STATE_ANNOUNCING:
420 if (autoip->ttw == 0) {
421 autoip_arp_announce(netif);
422 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_tmr() ANNOUNCING Sent Announce\n"));
423 autoip->ttw = ANNOUNCE_INTERVAL * AUTOIP_TICKS_PER_SECOND;
424 autoip->sent_num++;
425
426 if (autoip->sent_num >= ANNOUNCE_NUM) {
427 autoip->state = AUTOIP_STATE_BOUND;
428 autoip->sent_num = 0;
429 autoip->ttw = 0;
430 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
431 ("autoip_tmr(): changing state to BOUND: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
432 ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
433 ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
434 }
435 }
436 break;
437
438 default:
439 /* nothing to do in other states */
440 break;
441 }
442 }
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 */
452void
453autoip_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 SMEMCPY(netifaddr.addr, netif->hwaddr, ETH_HWADDR_LEN);
467
468 /* Copy struct ip4_addr_wordaligned to aligned ip4_addr, to support compilers without
469 * structure packing (not using structure copy which breaks strict-aliasing rules).
470 */
471 IPADDR_WORDALIGNED_COPY_TO_IP4_ADDR_T(&sipaddr, &hdr->sipaddr);
472 IPADDR_WORDALIGNED_COPY_TO_IP4_ADDR_T(&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 */
510u8_t
511autoip_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
520u8_t
521autoip_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 */
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