source: UsbWattMeter/trunk/lwip-1.4.1/src/core/ipv4/autoip.c@ 164

Last change on this file since 164 was 164, checked in by coas-nagasima, 8 years ago

TOPPERS/ECNLサンプルアプリ「USB充電器電力計」を追加
  • Property svn:eol-style set to native
  • Property svn:keywords set to Id
  • Property svn:mime-type set to text/x-csrc
File size: 17.7 KB
Line 
1/**
2 * @file
3 * AutoIP Automatic LinkLocal IP Configuration
4 *
5 */
6
7/*
8 *
9 * Copyright (c) 2007 Dominik Spies <kontakt@dspies.de>
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without modification,
13 * are permitted provided that the following conditions are met:
14 *
15 * 1. Redistributions of source code must retain the above copyright notice,
16 * this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright notice,
18 * this list of conditions and the following disclaimer in the documentation
19 * and/or other materials provided with the distribution.
20 * 3. The name of the author may not be used to endorse or promote products
21 * derived from this software without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
24 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
26 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
27 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
28 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
31 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
32 * OF SUCH DAMAGE.
33 *
34 * Author: Dominik Spies <kontakt@dspies.de>
35 *
36 * This is a AutoIP implementation for the lwIP TCP/IP stack. It aims to conform
37 * with RFC 3927.
38 *
39 *
40 * Please coordinate changes and requests with Dominik Spies
41 * <kontakt@dspies.de>
42 */
43
44/*******************************************************************************
45 * USAGE:
46 *
47 * define LWIP_AUTOIP 1 in your lwipopts.h
48 *
49 * If you don't use tcpip.c (so, don't call, you don't call tcpip_init):
50 * - First, call autoip_init().
51 * - call autoip_tmr() all AUTOIP_TMR_INTERVAL msces,
52 * that should be defined in autoip.h.
53 * I recommend a value of 100. The value must divide 1000 with a remainder almost 0.
54 * Possible values are 1000, 500, 333, 250, 200, 166, 142, 125, 111, 100 ....
55 *
56 * Without DHCP:
57 * - Call autoip_start() after netif_add().
58 *
59 * With DHCP:
60 * - define LWIP_DHCP_AUTOIP_COOP 1 in your lwipopts.h.
61 * - Configure your DHCP Client.
62 *
63 */
64
65#include "lwip/opt.h"
66
67#if LWIP_AUTOIP /* don't build if not configured for use in lwipopts.h */
68
69#include "lwip/mem.h"
70#include "lwip/udp.h"
71#include "lwip/ip_addr.h"
72#include "lwip/netif.h"
73#include "lwip/autoip.h"
74#include "netif/etharp.h"
75
76#include <stdlib.h>
77#include <string.h>
78
79/* 169.254.0.0 */
80#define AUTOIP_NET 0xA9FE0000
81/* 169.254.1.0 */
82#define AUTOIP_RANGE_START (AUTOIP_NET | 0x0100)
83/* 169.254.254.255 */
84#define AUTOIP_RANGE_END (AUTOIP_NET | 0xFEFF)
85
86
87/** Pseudo random macro based on netif informations.
88 * You could use "rand()" from the C Library if you define LWIP_AUTOIP_RAND in lwipopts.h */
89#ifndef LWIP_AUTOIP_RAND
90#define LWIP_AUTOIP_RAND(netif) ( (((u32_t)((netif->hwaddr[5]) & 0xff) << 24) | \
91 ((u32_t)((netif->hwaddr[3]) & 0xff) << 16) | \
92 ((u32_t)((netif->hwaddr[2]) & 0xff) << 8) | \
93 ((u32_t)((netif->hwaddr[4]) & 0xff))) + \
94 (netif->autoip?netif->autoip->tried_llipaddr:0))
95#endif /* LWIP_AUTOIP_RAND */
96
97/**
98 * Macro that generates the initial IP address to be tried by AUTOIP.
99 * If you want to override this, define it to something else in lwipopts.h.
100 */
101#ifndef LWIP_AUTOIP_CREATE_SEED_ADDR
102#define LWIP_AUTOIP_CREATE_SEED_ADDR(netif) \
103 htonl(AUTOIP_RANGE_START + ((u32_t)(((u8_t)(netif->hwaddr[4])) | \
104 ((u32_t)((u8_t)(netif->hwaddr[5]))) << 8)))
105#endif /* LWIP_AUTOIP_CREATE_SEED_ADDR */
106
107/* static functions */
108static void autoip_handle_arp_conflict(struct netif *netif);
109
110/* creates a pseudo random LL IP-Address for a network interface */
111static void autoip_create_addr(struct netif *netif, ip_addr_t *ipaddr);
112
113/* sends an ARP probe */
114static err_t autoip_arp_probe(struct netif *netif);
115
116/* sends an ARP announce */
117static err_t autoip_arp_announce(struct netif *netif);
118
119/* configure interface for use with current LL IP-Address */
120static err_t autoip_bind(struct netif *netif);
121
122/* start sending probes for llipaddr */
123static void autoip_start_probing(struct netif *netif);
124
125
126/** Set a statically allocated struct autoip to work with.
127 * Using this prevents autoip_start to allocate it using mem_malloc.
128 *
129 * @param netif the netif for which to set the struct autoip
130 * @param dhcp (uninitialised) dhcp struct allocated by the application
131 */
132void
133autoip_set_struct(struct netif *netif, struct autoip *autoip)
134{
135 LWIP_ASSERT("netif != NULL", netif != NULL);
136 LWIP_ASSERT("autoip != NULL", autoip != NULL);
137 LWIP_ASSERT("netif already has a struct autoip set", netif->autoip == NULL);
138
139 /* clear data structure */
140 memset(autoip, 0, sizeof(struct autoip));
141 /* autoip->state = AUTOIP_STATE_OFF; */
142 netif->autoip = autoip;
143}
144
145/** Restart AutoIP client and check the next address (conflict detected)
146 *
147 * @param netif The netif under AutoIP control
148 */
149static void
150autoip_restart(struct netif *netif)
151{
152 netif->autoip->tried_llipaddr++;
153 autoip_start(netif);
154}
155
156/**
157 * Handle a IP address conflict after an ARP conflict detection
158 */
159static void
160autoip_handle_arp_conflict(struct netif *netif)
161{
162 /* Somehow detect if we are defending or retreating */
163 unsigned char defend = 1; /* tbd */
164
165 if (defend) {
166 if (netif->autoip->lastconflict > 0) {
167 /* retreat, there was a conflicting ARP in the last
168 * DEFEND_INTERVAL seconds
169 */
170 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
171 ("autoip_handle_arp_conflict(): we are defending, but in DEFEND_INTERVAL, retreating\n"));
172
173 /* TODO: close all TCP sessions */
174 autoip_restart(netif);
175 } else {
176 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
177 ("autoip_handle_arp_conflict(): we are defend, send ARP Announce\n"));
178 autoip_arp_announce(netif);
179 netif->autoip->lastconflict = DEFEND_INTERVAL * AUTOIP_TICKS_PER_SECOND;
180 }
181 } else {
182 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
183 ("autoip_handle_arp_conflict(): we do not defend, retreating\n"));
184 /* TODO: close all TCP sessions */
185 autoip_restart(netif);
186 }
187}
188
189/**
190 * Create an IP-Address out of range 169.254.1.0 to 169.254.254.255
191 *
192 * @param netif network interface on which create the IP-Address
193 * @param ipaddr ip address to initialize
194 */
195static void
196autoip_create_addr(struct netif *netif, ip_addr_t *ipaddr)
197{
198 /* Here we create an IP-Address out of range 169.254.1.0 to 169.254.254.255
199 * compliant to RFC 3927 Section 2.1
200 * We have 254 * 256 possibilities */
201
202 u32_t addr = ntohl(LWIP_AUTOIP_CREATE_SEED_ADDR(netif));
203 addr += netif->autoip->tried_llipaddr;
204 addr = AUTOIP_NET | (addr & 0xffff);
205 /* Now, 169.254.0.0 <= addr <= 169.254.255.255 */
206
207 if (addr < AUTOIP_RANGE_START) {
208 addr += AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1;
209 }
210 if (addr > AUTOIP_RANGE_END) {
211 addr -= AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1;
212 }
213 LWIP_ASSERT("AUTOIP address not in range", (addr >= AUTOIP_RANGE_START) &&
214 (addr <= AUTOIP_RANGE_END));
215 ip4_addr_set_u32(ipaddr, htonl(addr));
216
217 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
218 ("autoip_create_addr(): tried_llipaddr=%"U16_F", %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
219 (u16_t)(netif->autoip->tried_llipaddr), ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr),
220 ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr)));
221}
222
223/**
224 * Sends an ARP probe from a network interface
225 *
226 * @param netif network interface used to send the probe
227 */
228static err_t
229autoip_arp_probe(struct netif *netif)
230{
231 return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, &ethbroadcast,
232 (struct eth_addr *)netif->hwaddr, IP_ADDR_ANY, &ethzero,
233 &netif->autoip->llipaddr, ARP_REQUEST);
234}
235
236/**
237 * Sends an ARP announce from a network interface
238 *
239 * @param netif network interface used to send the announce
240 */
241static err_t
242autoip_arp_announce(struct netif *netif)
243{
244 return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, &ethbroadcast,
245 (struct eth_addr *)netif->hwaddr, &netif->autoip->llipaddr, &ethzero,
246 &netif->autoip->llipaddr, ARP_REQUEST);
247}
248
249/**
250 * Configure interface for use with current LL IP-Address
251 *
252 * @param netif network interface to configure with current LL IP-Address
253 */
254static err_t
255autoip_bind(struct netif *netif)
256{
257 struct autoip *autoip = netif->autoip;
258 ip_addr_t sn_mask, gw_addr;
259
260 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
261 ("autoip_bind(netif=%p) %c%c%"U16_F" %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
262 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num,
263 ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
264 ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
265
266 IP4_ADDR(&sn_mask, 255, 255, 0, 0);
267 IP4_ADDR(&gw_addr, 0, 0, 0, 0);
268
269 netif_set_ipaddr(netif, &autoip->llipaddr);
270 netif_set_netmask(netif, &sn_mask);
271 netif_set_gw(netif, &gw_addr);
272
273 /* bring the interface up */
274 netif_set_up(netif);
275
276 return ERR_OK;
277}
278
279/**
280 * Start AutoIP client
281 *
282 * @param netif network interface on which start the AutoIP client
283 */
284err_t
285autoip_start(struct netif *netif)
286{
287 struct autoip *autoip = netif->autoip;
288 err_t result = ERR_OK;
289
290 if (netif_is_up(netif)) {
291 netif_set_down(netif);
292 }
293
294 /* Set IP-Address, Netmask and Gateway to 0 to make sure that
295 * ARP Packets are formed correctly
296 */
297 ip_addr_set_zero(&netif->ip_addr);
298 ip_addr_set_zero(&netif->netmask);
299 ip_addr_set_zero(&netif->gw);
300
301 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
302 ("autoip_start(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0],
303 netif->name[1], (u16_t)netif->num));
304 if (autoip == NULL) {
305 /* no AutoIP client attached yet? */
306 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
307 ("autoip_start(): starting new AUTOIP client\n"));
308 autoip = (struct autoip *)mem_malloc(sizeof(struct autoip));
309 if (autoip == NULL) {
310 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
311 ("autoip_start(): could not allocate autoip\n"));
312 return ERR_MEM;
313 }
314 memset(autoip, 0, sizeof(struct autoip));
315 /* store this AutoIP client in the netif */
316 netif->autoip = autoip;
317 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_start(): allocated autoip"));
318 } else {
319 autoip->state = AUTOIP_STATE_OFF;
320 autoip->ttw = 0;
321 autoip->sent_num = 0;
322 ip_addr_set_zero(&autoip->llipaddr);
323 autoip->lastconflict = 0;
324 }
325
326 autoip_create_addr(netif, &(autoip->llipaddr));
327 autoip_start_probing(netif);
328
329 return result;
330}
331
332static void
333autoip_start_probing(struct netif *netif)
334{
335 struct autoip *autoip = netif->autoip;
336
337 autoip->state = AUTOIP_STATE_PROBING;
338 autoip->sent_num = 0;
339 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
340 ("autoip_start_probing(): changing state to PROBING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
341 ip4_addr1_16(&netif->autoip->llipaddr), ip4_addr2_16(&netif->autoip->llipaddr),
342 ip4_addr3_16(&netif->autoip->llipaddr), ip4_addr4_16(&netif->autoip->llipaddr)));
343
344 /* time to wait to first probe, this is randomly
345 * choosen out of 0 to PROBE_WAIT seconds.
346 * compliant to RFC 3927 Section 2.2.1
347 */
348 autoip->ttw = (u16_t)(LWIP_AUTOIP_RAND(netif) % (PROBE_WAIT * AUTOIP_TICKS_PER_SECOND));
349
350 /*
351 * if we tried more then MAX_CONFLICTS we must limit our rate for
352 * accquiring and probing address
353 * compliant to RFC 3927 Section 2.2.1
354 */
355 if (autoip->tried_llipaddr > MAX_CONFLICTS) {
356 autoip->ttw = RATE_LIMIT_INTERVAL * AUTOIP_TICKS_PER_SECOND;
357 }
358}
359
360/**
361 * Handle a possible change in the network configuration.
362 *
363 * If there is an AutoIP address configured, take the interface down
364 * and begin probing with the same address.
365 */
366void
367autoip_network_changed(struct netif *netif)
368{
369 if (netif->autoip && netif->autoip->state != AUTOIP_STATE_OFF) {
370 netif_set_down(netif);
371 autoip_start_probing(netif);
372 }
373}
374
375/**
376 * Stop AutoIP client
377 *
378 * @param netif network interface on which stop the AutoIP client
379 */
380err_t
381autoip_stop(struct netif *netif)
382{
383 netif->autoip->state = AUTOIP_STATE_OFF;
384 netif_set_down(netif);
385 return ERR_OK;
386}
387
388/**
389 * Has to be called in loop every AUTOIP_TMR_INTERVAL milliseconds
390 */
391void
392autoip_tmr()
393{
394 struct netif *netif = netif_list;
395 /* loop through netif's */
396 while (netif != NULL) {
397 /* only act on AutoIP configured interfaces */
398 if (netif->autoip != NULL) {
399 if (netif->autoip->lastconflict > 0) {
400 netif->autoip->lastconflict--;
401 }
402
403 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
404 ("autoip_tmr() AutoIP-State: %"U16_F", ttw=%"U16_F"\n",
405 (u16_t)(netif->autoip->state), netif->autoip->ttw));
406
407 switch(netif->autoip->state) {
408 case AUTOIP_STATE_PROBING:
409 if (netif->autoip->ttw > 0) {
410 netif->autoip->ttw--;
411 } else {
412 if (netif->autoip->sent_num >= PROBE_NUM) {
413 netif->autoip->state = AUTOIP_STATE_ANNOUNCING;
414 netif->autoip->sent_num = 0;
415 netif->autoip->ttw = ANNOUNCE_WAIT * AUTOIP_TICKS_PER_SECOND;
416 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
417 ("autoip_tmr(): changing state to ANNOUNCING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
418 ip4_addr1_16(&netif->autoip->llipaddr), ip4_addr2_16(&netif->autoip->llipaddr),
419 ip4_addr3_16(&netif->autoip->llipaddr), ip4_addr4_16(&netif->autoip->llipaddr)));
420 } else {
421 autoip_arp_probe(netif);
422 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
423 ("autoip_tmr() PROBING Sent Probe\n"));
424 netif->autoip->sent_num++;
425 /* calculate time to wait to next probe */
426 netif->autoip->ttw = (u16_t)((LWIP_AUTOIP_RAND(netif) %
427 ((PROBE_MAX - PROBE_MIN) * AUTOIP_TICKS_PER_SECOND) ) +
428 PROBE_MIN * AUTOIP_TICKS_PER_SECOND);
429 }
430 }
431 break;
432
433 case AUTOIP_STATE_ANNOUNCING:
434 if (netif->autoip->ttw > 0) {
435 netif->autoip->ttw--;
436 } else {
437 if (netif->autoip->sent_num == 0) {
438 /* We are here the first time, so we waited ANNOUNCE_WAIT seconds
439 * Now we can bind to an IP address and use it.
440 *
441 * autoip_bind calls netif_set_up. This triggers a gratuitous ARP
442 * which counts as an announcement.
443 */
444 autoip_bind(netif);
445 } else {
446 autoip_arp_announce(netif);
447 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
448 ("autoip_tmr() ANNOUNCING Sent Announce\n"));
449 }
450 netif->autoip->ttw = ANNOUNCE_INTERVAL * AUTOIP_TICKS_PER_SECOND;
451 netif->autoip->sent_num++;
452
453 if (netif->autoip->sent_num >= ANNOUNCE_NUM) {
454 netif->autoip->state = AUTOIP_STATE_BOUND;
455 netif->autoip->sent_num = 0;
456 netif->autoip->ttw = 0;
457 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
458 ("autoip_tmr(): changing state to BOUND: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
459 ip4_addr1_16(&netif->autoip->llipaddr), ip4_addr2_16(&netif->autoip->llipaddr),
460 ip4_addr3_16(&netif->autoip->llipaddr), ip4_addr4_16(&netif->autoip->llipaddr)));
461 }
462 }
463 break;
464 }
465 }
466 /* proceed to next network interface */
467 netif = netif->next;
468 }
469}
470
471/**
472 * Handles every incoming ARP Packet, called by etharp_arp_input.
473 *
474 * @param netif network interface to use for autoip processing
475 * @param hdr Incoming ARP packet
476 */
477void
478autoip_arp_reply(struct netif *netif, struct etharp_hdr *hdr)
479{
480 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_arp_reply()\n"));
481 if ((netif->autoip != NULL) && (netif->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 ip_addr_t sipaddr, dipaddr;
488 struct eth_addr netifaddr;
489 ETHADDR16_COPY(netifaddr.addr, netif->hwaddr);
490
491 /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without
492 * structure packing (not using structure copy which breaks strict-aliasing rules).
493 */
494 IPADDR2_COPY(&sipaddr, &hdr->sipaddr);
495 IPADDR2_COPY(&dipaddr, &hdr->dipaddr);
496
497 if ((netif->autoip->state == AUTOIP_STATE_PROBING) ||
498 ((netif->autoip->state == AUTOIP_STATE_ANNOUNCING) &&
499 (netif->autoip->sent_num == 0))) {
500 /* RFC 3927 Section 2.2.1:
501 * from beginning to after ANNOUNCE_WAIT
502 * seconds we have a conflict if
503 * ip.src == llipaddr OR
504 * ip.dst == llipaddr && hw.src != own hwaddr
505 */
506 if ((ip_addr_cmp(&sipaddr, &netif->autoip->llipaddr)) ||
507 (ip_addr_cmp(&dipaddr, &netif->autoip->llipaddr) &&
508 !eth_addr_cmp(&netifaddr, &hdr->shwaddr))) {
509 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
510 ("autoip_arp_reply(): Probe Conflict detected\n"));
511 autoip_restart(netif);
512 }
513 } else {
514 /* RFC 3927 Section 2.5:
515 * in any state we have a conflict if
516 * ip.src == llipaddr && hw.src != own hwaddr
517 */
518 if (ip_addr_cmp(&sipaddr, &netif->autoip->llipaddr) &&
519 !eth_addr_cmp(&netifaddr, &hdr->shwaddr)) {
520 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
521 ("autoip_arp_reply(): Conflicting ARP-Packet detected\n"));
522 autoip_handle_arp_conflict(netif);
523 }
524 }
525 }
526}
527
528#endif /* LWIP_AUTOIP */
Note: See TracBrowser for help on using the repository browser.