92bb4591f1aa1511ec08447faa7f7bdd6266c948
3 * AutoIP Automatic LinkLocal IP Configuration
9 * Copyright (c) 2007 Dominik Spies <kontakt@dspies.de>
10 * All rights reserved.
12 * Redistribution and use in source and binary forms, with or without modification,
13 * are permitted provided that the following conditions are met:
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.
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
34 * Author: Dominik Spies <kontakt@dspies.de>
36 * This is a AutoIP implementation for the lwIP TCP/IP stack. It aims to conform
40 * Please coordinate changes and requests with Dominik Spies
44 /*******************************************************************************
47 * define LWIP_AUTOIP 1 in your lwipopts.h
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 ....
57 * - Call autoip_start() after netif_add().
60 * - define LWIP_DHCP_AUTOIP_COOP 1 in your lwipopts.h.
61 * - Configure your DHCP Client.
67 #if LWIP_AUTOIP /* don't build if not configured for use in lwipopts.h */
71 #include "lwip/ip_addr.h"
72 #include "lwip/netif.h"
73 #include "lwip/autoip.h"
74 #include "netif/etharp.h"
80 #define AUTOIP_NET 0xA9FE0000
82 #define AUTOIP_RANGE_START (AUTOIP_NET | 0x0100)
84 #define AUTOIP_RANGE_END (AUTOIP_NET | 0xFEFF)
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 */
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.
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 */
107 /* static functions */
108 static void autoip_handle_arp_conflict(struct netif
*netif
);
110 /* creates a pseudo random LL IP-Address for a network interface */
111 static void autoip_create_addr(struct netif
*netif
, ip_addr_t
*ipaddr
);
113 /* sends an ARP probe */
114 static err_t
autoip_arp_probe(struct netif
*netif
);
116 /* sends an ARP announce */
117 static err_t
autoip_arp_announce(struct netif
*netif
);
119 /* configure interface for use with current LL IP-Address */
120 static err_t
autoip_bind(struct netif
*netif
);
122 /* start sending probes for llipaddr */
123 static void autoip_start_probing(struct netif
*netif
);
126 * Initialize this module
131 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
, ("autoip_init()\n"));
134 /** Set a statically allocated struct autoip to work with.
135 * Using this prevents autoip_start to allocate it using mem_malloc.
137 * @param netif the netif for which to set the struct autoip
138 * @param dhcp (uninitialised) dhcp struct allocated by the application
141 autoip_set_struct(struct netif
*netif
, struct autoip
*autoip
)
143 LWIP_ASSERT("netif != NULL", netif
!= NULL
);
144 LWIP_ASSERT("autoip != NULL", autoip
!= NULL
);
145 LWIP_ASSERT("netif already has a struct autoip set", netif
->autoip
== NULL
);
147 /* clear data structure */
148 memset(autoip
, 0, sizeof(struct autoip
));
149 /* autoip->state = AUTOIP_STATE_OFF; */
150 netif
->autoip
= autoip
;
153 /** Restart AutoIP client and check the next address (conflict detected)
155 * @param netif The netif under AutoIP control
158 autoip_restart(struct netif
*netif
)
160 netif
->autoip
->tried_llipaddr
++;
165 * Handle a IP address conflict after an ARP conflict detection
168 autoip_handle_arp_conflict(struct netif
*netif
)
170 /* Somehow detect if we are defending or retreating */
171 unsigned char defend
= 1; /* tbd */
174 if(netif
->autoip
->lastconflict
> 0) {
175 /* retreat, there was a conflicting ARP in the last
176 * DEFEND_INTERVAL seconds
178 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
| LWIP_DBG_STATE
,
179 ("autoip_handle_arp_conflict(): we are defending, but in DEFEND_INTERVAL, retreating\n"));
181 /* TODO: close all TCP sessions */
182 autoip_restart(netif
);
184 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
| LWIP_DBG_STATE
,
185 ("autoip_handle_arp_conflict(): we are defend, send ARP Announce\n"));
186 autoip_arp_announce(netif
);
187 netif
->autoip
->lastconflict
= DEFEND_INTERVAL
* AUTOIP_TICKS_PER_SECOND
;
190 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
| LWIP_DBG_STATE
,
191 ("autoip_handle_arp_conflict(): we do not defend, retreating\n"));
192 /* TODO: close all TCP sessions */
193 autoip_restart(netif
);
198 * Create an IP-Address out of range 169.254.1.0 to 169.254.254.255
200 * @param netif network interface on which create the IP-Address
201 * @param ipaddr ip address to initialize
204 autoip_create_addr(struct netif
*netif
, ip_addr_t
*ipaddr
)
206 /* Here we create an IP-Address out of range 169.254.1.0 to 169.254.254.255
207 * compliant to RFC 3927 Section 2.1
208 * We have 254 * 256 possibilities */
210 u32_t addr
= ntohl(LWIP_AUTOIP_CREATE_SEED_ADDR(netif
));
211 addr
+= netif
->autoip
->tried_llipaddr
;
212 addr
= AUTOIP_NET
| (addr
& 0xffff);
213 /* Now, 169.254.0.0 <= addr <= 169.254.255.255 */
215 if (addr
< AUTOIP_RANGE_START
) {
216 addr
+= AUTOIP_RANGE_END
- AUTOIP_RANGE_START
+ 1;
218 if (addr
> AUTOIP_RANGE_END
) {
219 addr
-= AUTOIP_RANGE_END
- AUTOIP_RANGE_START
+ 1;
221 LWIP_ASSERT("AUTOIP address not in range", (addr
>= AUTOIP_RANGE_START
) &&
222 (addr
<= AUTOIP_RANGE_END
));
223 ip4_addr_set_u32(ipaddr
, htonl(addr
));
225 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
| LWIP_DBG_STATE
,
226 ("autoip_create_addr(): tried_llipaddr=%"U16_F
", %"U16_F
".%"U16_F
".%"U16_F
".%"U16_F
"\n",
227 (u16_t
)(netif
->autoip
->tried_llipaddr
), ip4_addr1_16(ipaddr
), ip4_addr2_16(ipaddr
),
228 ip4_addr3_16(ipaddr
), ip4_addr4_16(ipaddr
)));
232 * Sends an ARP probe from a network interface
234 * @param netif network interface used to send the probe
237 autoip_arp_probe(struct netif
*netif
)
239 return etharp_raw(netif
, (struct eth_addr
*)netif
->hwaddr
, ðbroadcast
,
240 (struct eth_addr
*)netif
->hwaddr
, IP_ADDR_ANY
, ðzero
,
241 &netif
->autoip
->llipaddr
, ARP_REQUEST
);
245 * Sends an ARP announce from a network interface
247 * @param netif network interface used to send the announce
250 autoip_arp_announce(struct netif
*netif
)
252 return etharp_raw(netif
, (struct eth_addr
*)netif
->hwaddr
, ðbroadcast
,
253 (struct eth_addr
*)netif
->hwaddr
, &netif
->autoip
->llipaddr
, ðzero
,
254 &netif
->autoip
->llipaddr
, ARP_REQUEST
);
258 * Configure interface for use with current LL IP-Address
260 * @param netif network interface to configure with current LL IP-Address
263 autoip_bind(struct netif
*netif
)
265 struct autoip
*autoip
= netif
->autoip
;
266 ip_addr_t sn_mask
, gw_addr
;
268 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
,
269 ("autoip_bind(netif=%p) %c%c%"U16_F
" %"U16_F
".%"U16_F
".%"U16_F
".%"U16_F
"\n",
270 (void*)netif
, netif
->name
[0], netif
->name
[1], (u16_t
)netif
->num
,
271 ip4_addr1_16(&autoip
->llipaddr
), ip4_addr2_16(&autoip
->llipaddr
),
272 ip4_addr3_16(&autoip
->llipaddr
), ip4_addr4_16(&autoip
->llipaddr
)));
274 IP4_ADDR(&sn_mask
, 255, 255, 0, 0);
275 IP4_ADDR(&gw_addr
, 0, 0, 0, 0);
277 netif_set_ipaddr(netif
, &autoip
->llipaddr
);
278 netif_set_netmask(netif
, &sn_mask
);
279 netif_set_gw(netif
, &gw_addr
);
281 /* bring the interface up */
288 * Start AutoIP client
290 * @param netif network interface on which start the AutoIP client
293 autoip_start(struct netif
*netif
)
295 struct autoip
*autoip
= netif
->autoip
;
296 err_t result
= ERR_OK
;
298 if(netif_is_up(netif
)) {
299 netif_set_down(netif
);
302 /* Set IP-Address, Netmask and Gateway to 0 to make sure that
303 * ARP Packets are formed correctly
305 ip_addr_set_zero(&netif
->ip_addr
);
306 ip_addr_set_zero(&netif
->netmask
);
307 ip_addr_set_zero(&netif
->gw
);
309 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
| LWIP_DBG_STATE
,
310 ("autoip_start(netif=%p) %c%c%"U16_F
"\n", (void*)netif
, netif
->name
[0],
311 netif
->name
[1], (u16_t
)netif
->num
));
313 /* no AutoIP client attached yet? */
314 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
,
315 ("autoip_start(): starting new AUTOIP client\n"));
316 autoip
= (struct autoip
*)mem_malloc(sizeof(struct autoip
));
318 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
,
319 ("autoip_start(): could not allocate autoip\n"));
322 memset(autoip
, 0, sizeof(struct autoip
));
323 /* store this AutoIP client in the netif */
324 netif
->autoip
= autoip
;
325 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
, ("autoip_start(): allocated autoip"));
327 autoip
->state
= AUTOIP_STATE_OFF
;
329 autoip
->sent_num
= 0;
330 ip_addr_set_zero(&autoip
->llipaddr
);
331 autoip
->lastconflict
= 0;
334 autoip_create_addr(netif
, &(autoip
->llipaddr
));
335 autoip_start_probing(netif
);
341 autoip_start_probing(struct netif
*netif
)
343 struct autoip
*autoip
= netif
->autoip
;
345 autoip
->state
= AUTOIP_STATE_PROBING
;
346 autoip
->sent_num
= 0;
347 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
| LWIP_DBG_STATE
,
348 ("autoip_start_probing(): changing state to PROBING: %"U16_F
".%"U16_F
".%"U16_F
".%"U16_F
"\n",
349 ip4_addr1_16(&netif
->autoip
->llipaddr
), ip4_addr2_16(&netif
->autoip
->llipaddr
),
350 ip4_addr3_16(&netif
->autoip
->llipaddr
), ip4_addr4_16(&netif
->autoip
->llipaddr
)));
352 /* time to wait to first probe, this is randomly
353 * choosen out of 0 to PROBE_WAIT seconds.
354 * compliant to RFC 3927 Section 2.2.1
356 autoip
->ttw
= (u16_t
)(LWIP_AUTOIP_RAND(netif
) % (PROBE_WAIT
* AUTOIP_TICKS_PER_SECOND
));
359 * if we tried more then MAX_CONFLICTS we must limit our rate for
360 * accquiring and probing address
361 * compliant to RFC 3927 Section 2.2.1
363 if(autoip
->tried_llipaddr
> MAX_CONFLICTS
) {
364 autoip
->ttw
= RATE_LIMIT_INTERVAL
* AUTOIP_TICKS_PER_SECOND
;
369 * Handle a possible change in the network configuration.
371 * If there is an AutoIP address configured, take the interface down
372 * and begin probing with the same address.
375 autoip_network_changed(struct netif
*netif
)
377 if (netif
->autoip
&& netif
->autoip
->state
!= AUTOIP_STATE_OFF
) {
378 netif_set_down(netif
);
379 autoip_start_probing(netif
);
386 * @param netif network interface on which stop the AutoIP client
389 autoip_stop(struct netif
*netif
)
391 netif
->autoip
->state
= AUTOIP_STATE_OFF
;
392 netif_set_down(netif
);
397 * Has to be called in loop every AUTOIP_TMR_INTERVAL milliseconds
402 struct netif
*netif
= netif_list
;
403 /* loop through netif's */
404 while (netif
!= NULL
) {
405 /* only act on AutoIP configured interfaces */
406 if (netif
->autoip
!= NULL
) {
407 if(netif
->autoip
->lastconflict
> 0) {
408 netif
->autoip
->lastconflict
--;
411 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
,
412 ("autoip_tmr() AutoIP-State: %"U16_F
", ttw=%"U16_F
"\n",
413 (u16_t
)(netif
->autoip
->state
), netif
->autoip
->ttw
));
415 switch(netif
->autoip
->state
) {
416 case AUTOIP_STATE_PROBING
:
417 if(netif
->autoip
->ttw
> 0) {
418 netif
->autoip
->ttw
--;
420 if(netif
->autoip
->sent_num
>= PROBE_NUM
) {
421 netif
->autoip
->state
= AUTOIP_STATE_ANNOUNCING
;
422 netif
->autoip
->sent_num
= 0;
423 netif
->autoip
->ttw
= ANNOUNCE_WAIT
* AUTOIP_TICKS_PER_SECOND
;
424 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
| LWIP_DBG_STATE
,
425 ("autoip_tmr(): changing state to ANNOUNCING: %"U16_F
".%"U16_F
".%"U16_F
".%"U16_F
"\n",
426 ip4_addr1_16(&netif
->autoip
->llipaddr
), ip4_addr2_16(&netif
->autoip
->llipaddr
),
427 ip4_addr3_16(&netif
->autoip
->llipaddr
), ip4_addr4_16(&netif
->autoip
->llipaddr
)));
429 autoip_arp_probe(netif
);
430 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
,
431 ("autoip_tmr() PROBING Sent Probe\n"));
432 netif
->autoip
->sent_num
++;
433 /* calculate time to wait to next probe */
434 netif
->autoip
->ttw
= (u16_t
)((LWIP_AUTOIP_RAND(netif
) %
435 ((PROBE_MAX
- PROBE_MIN
) * AUTOIP_TICKS_PER_SECOND
) ) +
436 PROBE_MIN
* AUTOIP_TICKS_PER_SECOND
);
441 case AUTOIP_STATE_ANNOUNCING
:
442 if(netif
->autoip
->ttw
> 0) {
443 netif
->autoip
->ttw
--;
445 if(netif
->autoip
->sent_num
== 0) {
446 /* We are here the first time, so we waited ANNOUNCE_WAIT seconds
447 * Now we can bind to an IP address and use it.
449 * autoip_bind calls netif_set_up. This triggers a gratuitous ARP
450 * which counts as an announcement.
454 autoip_arp_announce(netif
);
455 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
,
456 ("autoip_tmr() ANNOUNCING Sent Announce\n"));
458 netif
->autoip
->ttw
= ANNOUNCE_INTERVAL
* AUTOIP_TICKS_PER_SECOND
;
459 netif
->autoip
->sent_num
++;
461 if(netif
->autoip
->sent_num
>= ANNOUNCE_NUM
) {
462 netif
->autoip
->state
= AUTOIP_STATE_BOUND
;
463 netif
->autoip
->sent_num
= 0;
464 netif
->autoip
->ttw
= 0;
465 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
| LWIP_DBG_STATE
,
466 ("autoip_tmr(): changing state to BOUND: %"U16_F
".%"U16_F
".%"U16_F
".%"U16_F
"\n",
467 ip4_addr1_16(&netif
->autoip
->llipaddr
), ip4_addr2_16(&netif
->autoip
->llipaddr
),
468 ip4_addr3_16(&netif
->autoip
->llipaddr
), ip4_addr4_16(&netif
->autoip
->llipaddr
)));
474 /* proceed to next network interface */
480 * Handles every incoming ARP Packet, called by etharp_arp_input.
482 * @param netif network interface to use for autoip processing
483 * @param hdr Incoming ARP packet
486 autoip_arp_reply(struct netif
*netif
, struct etharp_hdr
*hdr
)
488 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
, ("autoip_arp_reply()\n"));
489 if ((netif
->autoip
!= NULL
) && (netif
->autoip
->state
!= AUTOIP_STATE_OFF
)) {
490 /* when ip.src == llipaddr && hw.src != netif->hwaddr
492 * when probing ip.dst == llipaddr && hw.src != netif->hwaddr
493 * we have a conflict and must solve it
495 ip_addr_t sipaddr
, dipaddr
;
496 struct eth_addr netifaddr
;
497 ETHADDR16_COPY(netifaddr
.addr
, netif
->hwaddr
);
499 /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without
500 * structure packing (not using structure copy which breaks strict-aliasing rules).
502 IPADDR2_COPY(&sipaddr
, &hdr
->sipaddr
);
503 IPADDR2_COPY(&dipaddr
, &hdr
->dipaddr
);
505 if ((netif
->autoip
->state
== AUTOIP_STATE_PROBING
) ||
506 ((netif
->autoip
->state
== AUTOIP_STATE_ANNOUNCING
) &&
507 (netif
->autoip
->sent_num
== 0))) {
508 /* RFC 3927 Section 2.2.1:
509 * from beginning to after ANNOUNCE_WAIT
510 * seconds we have a conflict if
511 * ip.src == llipaddr OR
512 * ip.dst == llipaddr && hw.src != own hwaddr
514 if ((ip_addr_cmp(&sipaddr
, &netif
->autoip
->llipaddr
)) ||
515 (ip_addr_cmp(&dipaddr
, &netif
->autoip
->llipaddr
) &&
516 !eth_addr_cmp(&netifaddr
, &hdr
->shwaddr
))) {
517 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
| LWIP_DBG_STATE
| LWIP_DBG_LEVEL_WARNING
,
518 ("autoip_arp_reply(): Probe Conflict detected\n"));
519 autoip_restart(netif
);
522 /* RFC 3927 Section 2.5:
523 * in any state we have a conflict if
524 * ip.src == llipaddr && hw.src != own hwaddr
526 if (ip_addr_cmp(&sipaddr
, &netif
->autoip
->llipaddr
) &&
527 !eth_addr_cmp(&netifaddr
, &hdr
->shwaddr
)) {
528 LWIP_DEBUGF(AUTOIP_DEBUG
| LWIP_DBG_TRACE
| LWIP_DBG_STATE
| LWIP_DBG_LEVEL_WARNING
,
529 ("autoip_arp_reply(): Conflicting ARP-Packet detected\n"));
530 autoip_handle_arp_conflict(netif
);
536 #endif /* LWIP_AUTOIP */