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. It uses IPv4 address conflict detection to evaluate the chosen
7 * address. The ACD module aims to be conform to RFC 5227.
8 * RFC 5227 is extracted out of RFC 3927 so the acd module fits nicely in autoip.
9 *
10 * @defgroup autoip AUTOIP
11 * @ingroup ip4
12 * AUTOIP related functions
13 * USAGE:
14 *
15 * define @ref LWIP_AUTOIP 1 in your lwipopts.h
16 *
17 * Without DHCP:
18 * - Call autoip_start() after netif_add().
19 *
20 * With DHCP:
21 * - define @ref LWIP_DHCP_AUTOIP_COOP 1 in your lwipopts.h.
22 * - Configure your DHCP Client.
23 *
24 * @see netifapi_autoip
25 */
26
27 /*
28 *
29 * Copyright (c) 2007 Dominik Spies <[email protected]>
30 * All rights reserved.
31 *
32 * Redistribution and use in source and binary forms, with or without modification,
33 * are permitted provided that the following conditions are met:
34 *
35 * 1. Redistributions of source code must retain the above copyright notice,
36 * this list of conditions and the following disclaimer.
37 * 2. Redistributions in binary form must reproduce the above copyright notice,
38 * this list of conditions and the following disclaimer in the documentation
39 * and/or other materials provided with the distribution.
40 * 3. The name of the author may not be used to endorse or promote products
41 * derived from this software without specific prior written permission.
42 *
43 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
44 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
45 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
46 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
47 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
48 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
49 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
50 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
51 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
52 * OF SUCH DAMAGE.
53 *
54 * Author: Dominik Spies <[email protected]>
55 */
56
57 #include "lwip/opt.h"
58
59 #if LWIP_IPV4 && LWIP_AUTOIP /* don't build if not configured for use in lwipopts.h */
60
61 #include "lwip/mem.h"
62 /* #include "lwip/udp.h" */
63 #include "lwip/ip_addr.h"
64 #include "lwip/netif.h"
65 #include "lwip/autoip.h"
66 #include "lwip/acd.h"
67 #include "lwip/etharp.h"
68 #include "lwip/prot/autoip.h"
69
70 #include <string.h>
71
72 /**
73 * Macro that generates the initial IP address to be tried by AUTOIP.
74 * If you want to override this, define it to something else in lwipopts.h.
75 */
76 #ifndef LWIP_AUTOIP_CREATE_SEED_ADDR
77 #define LWIP_AUTOIP_CREATE_SEED_ADDR(netif) \
78 lwip_htonl(AUTOIP_RANGE_START + ((u32_t)(((u8_t)(netif->hwaddr[4])) | \
79 ((u32_t)((u8_t)(netif->hwaddr[5]))) << 8)))
80 #endif /* LWIP_AUTOIP_CREATE_SEED_ADDR */
81
82 /* Function definitions */
83 static void autoip_restart(struct netif *netif);
84 static void autoip_create_addr(struct netif *netif, ip4_addr_t *ipaddr);
85 static err_t autoip_bind(struct netif *netif);
86 static void autoip_conflict_callback(struct netif *netif,
87 acd_callback_enum_t state);
88
89 /**
90 * @ingroup autoip
91 * Set a statically allocated struct autoip to work with.
92 * Using this prevents autoip_start to allocate it using mem_malloc.
93 *
94 * @param netif the netif for which to set the struct autoip
95 * @param autoip (uninitialised) autoip struct allocated by the application
96 */
97 void
autoip_set_struct(struct netif * netif,struct autoip * autoip)98 autoip_set_struct(struct netif *netif, struct autoip *autoip)
99 {
100 LWIP_ASSERT_CORE_LOCKED();
101 LWIP_ASSERT("netif != NULL", netif != NULL);
102 LWIP_ASSERT("autoip != NULL", autoip != NULL);
103 LWIP_ASSERT("netif already has a struct autoip set",
104 netif_autoip_data(netif) == NULL);
105
106 /* clear data structure */
107 memset(autoip, 0, sizeof(struct autoip));
108 /* autoip->state = AUTOIP_STATE_OFF; */
109 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_AUTOIP, autoip);
110 }
111
112 /** Restart AutoIP client and check the next address (conflict detected)
113 *
114 * @param netif The netif under AutoIP control
115 */
116 static void
autoip_restart(struct netif * netif)117 autoip_restart(struct netif *netif)
118 {
119 struct autoip *autoip = netif_autoip_data(netif);
120 autoip->tried_llipaddr++;
121 autoip_start(netif);
122 }
123
124
125 /**
126 * Create an IP-Address out of range 169.254.1.0 to 169.254.254.255
127 *
128 * @param netif network interface on which create the IP-Address
129 * @param ipaddr ip address to initialize
130 */
131 static void
autoip_create_addr(struct netif * netif,ip4_addr_t * ipaddr)132 autoip_create_addr(struct netif *netif, ip4_addr_t *ipaddr)
133 {
134 struct autoip *autoip = netif_autoip_data(netif);
135
136 /* Here we create an IP-Address out of range 169.254.1.0 to 169.254.254.255
137 * compliant to RFC 3927 Section 2.1
138 * We have 254 * 256 possibilities */
139
140 u32_t addr = lwip_ntohl(LWIP_AUTOIP_CREATE_SEED_ADDR(netif));
141 addr += autoip->tried_llipaddr;
142 addr = AUTOIP_NET | (addr & 0xffff);
143 /* Now, 169.254.0.0 <= addr <= 169.254.255.255 */
144
145 if (addr < AUTOIP_RANGE_START) {
146 addr += AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1;
147 }
148 if (addr > AUTOIP_RANGE_END) {
149 addr -= AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1;
150 }
151 LWIP_ASSERT("AUTOIP address not in range", (addr >= AUTOIP_RANGE_START) &&
152 (addr <= AUTOIP_RANGE_END));
153 ip4_addr_set_u32(ipaddr, lwip_htonl(addr));
154
155 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
156 ("autoip_create_addr(): tried_llipaddr=%"U16_F", %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
157 (u16_t)(autoip->tried_llipaddr), ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr),
158 ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr)));
159 }
160
161
162 /**
163 * Configure interface for use with current LL IP-Address
164 *
165 * @param netif network interface to configure with current LL IP-Address
166 */
167 static err_t
autoip_bind(struct netif * netif)168 autoip_bind(struct netif *netif)
169 {
170 struct autoip *autoip = netif_autoip_data(netif);
171 ip4_addr_t sn_mask, gw_addr;
172
173 autoip->state = AUTOIP_STATE_BOUND;
174
175 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
176 ("autoip_bind(netif=%p) %c%c%"U16_F" %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
177 (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num,
178 ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
179 ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
180
181 IP4_ADDR(&sn_mask, 255, 255, 0, 0);
182 IP4_ADDR(&gw_addr, 0, 0, 0, 0);
183
184 netif_set_addr(netif, &autoip->llipaddr, &sn_mask, &gw_addr);
185 /* interface is used by routing now that an address is set */
186
187 return ERR_OK;
188 }
189
190 /**
191 * Handle conflict information from ACD module
192 *
193 * @param netif network interface to handle conflict information on
194 * @param state acd_callback_enum_t
195 */
196 static void
autoip_conflict_callback(struct netif * netif,acd_callback_enum_t state)197 autoip_conflict_callback(struct netif *netif, acd_callback_enum_t state)
198 {
199 struct autoip *autoip = netif_autoip_data(netif);
200
201 switch (state) {
202 case ACD_IP_OK:
203 autoip_bind(netif);
204 break;
205 case ACD_RESTART_CLIENT:
206 autoip_restart(netif);
207 break;
208 case ACD_DECLINE:
209 /* "delete" conflicting address so a new one will be selected in
210 * autoip_start() */
211 ip4_addr_set_any(&autoip->llipaddr);
212 autoip_stop(netif);
213 break;
214 default:
215 break;
216 }
217 }
218
219 /**
220 * @ingroup autoip
221 * Start AutoIP client
222 *
223 * @param netif network interface on which start the AutoIP client
224 */
225 err_t
autoip_start(struct netif * netif)226 autoip_start(struct netif *netif)
227 {
228 struct autoip *autoip = netif_autoip_data(netif);
229 err_t result = ERR_OK;
230
231 LWIP_ASSERT_CORE_LOCKED();
232 LWIP_ERROR("netif is not up, old style port?", netif_is_up(netif), return ERR_ARG;);
233
234 if (autoip->state == AUTOIP_STATE_OFF) {
235 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
236 ("autoip_start(netif=%p) %c%c%"U16_F"\n", (void *)netif, netif->name[0],
237 netif->name[1], (u16_t)netif->num));
238 if (autoip == NULL) {
239 /* no AutoIP client attached yet? */
240 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
241 ("autoip_start(): starting new AUTOIP client\n"));
242 autoip = (struct autoip *)mem_calloc(1, sizeof(struct autoip));
243 if (autoip == NULL) {
244 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
245 ("autoip_start(): could not allocate autoip\n"));
246 return ERR_MEM;
247 }
248 /* store this AutoIP client in the netif */
249 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_AUTOIP, autoip);
250 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_start(): allocated autoip"));
251 }
252
253 /* add acd struct to list*/
254 acd_add(netif, &autoip->acd, autoip_conflict_callback);
255
256 /* In accordance to RFC3927 section 2.1:
257 * Keep using the same link local address as much as possible.
258 * Only when their is none or when their was a conflict, select a new one.
259 */
260 if (!ip4_addr_islinklocal(&autoip->llipaddr)) {
261 autoip_create_addr(netif, &(autoip->llipaddr));
262 }
263 autoip->state = AUTOIP_STATE_CHECKING;
264 acd_start(netif, &autoip->acd, autoip->llipaddr);
265 }
266 else {
267 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
268 ("autoip_start(): already started on netif=%p %c%c%"U16_F"\n",
269 (void *)netif, netif->name[0],
270 netif->name[1], (u16_t)netif->num));
271 }
272
273 return result;
274 }
275
276
277 /**
278 * Handle a possible change in the network configuration: link up
279 *
280 * If there is an AutoIP address configured and AutoIP is not in cooperation
281 * with DHCP, start probing for previous address.
282 */
283 void
autoip_network_changed_link_up(struct netif * netif)284 autoip_network_changed_link_up(struct netif *netif)
285 {
286 struct autoip *autoip = netif_autoip_data(netif);
287
288 if (autoip && (autoip->state != AUTOIP_STATE_OFF) && !LWIP_DHCP_AUTOIP_COOP) {
289 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
290 ("autoip_network_changed_link_up(): start acd"));
291 autoip->state = AUTOIP_STATE_CHECKING;
292 /* Start acd check again for the last used address */
293 acd_start(netif, &autoip->acd, autoip->llipaddr);
294 }
295 }
296
297 /**
298 * Handle a possible change in the network configuration: link down
299 *
300 * If there is an AutoIP address configured and AutoIP is in cooperation
301 * with DHCP, then stop the autoip module. When the link goes up, we do not want
302 * the autoip module to start again. DHCP will initiate autoip when needed.
303 */
304 void
autoip_network_changed_link_down(struct netif * netif)305 autoip_network_changed_link_down(struct netif *netif)
306 {
307 struct autoip *autoip = netif_autoip_data(netif);
308
309 if (autoip && (autoip->state != AUTOIP_STATE_OFF) && LWIP_DHCP_AUTOIP_COOP) {
310 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
311 ("autoip_network_changed_link_down(): stop autoip"));
312 autoip_stop(netif);
313 }
314 }
315
316 /**
317 * @ingroup autoip
318 * Stop AutoIP client
319 *
320 * @param netif network interface on which stop the AutoIP client
321 */
322 err_t
autoip_stop(struct netif * netif)323 autoip_stop(struct netif *netif)
324 {
325 struct autoip *autoip = netif_autoip_data(netif);
326
327 LWIP_ASSERT_CORE_LOCKED();
328 if (autoip != NULL) {
329 autoip->state = AUTOIP_STATE_OFF;
330 if (ip4_addr_islinklocal(netif_ip4_addr(netif))) {
331 netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4);
332 }
333 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,("autoip_stop()"));
334 }
335 return ERR_OK;
336 }
337
338 /** check if AutoIP supplied netif->ip_addr
339 *
340 * @param netif the netif to check
341 * @return 1 if AutoIP supplied netif->ip_addr (state BOUND),
342 * 0 otherwise
343 */
344 u8_t
autoip_supplied_address(struct netif * netif)345 autoip_supplied_address(struct netif *netif)
346 {
347 struct autoip *autoip = netif_autoip_data(netif);
348 return (autoip != NULL)
349 && (ip4_addr_cmp(netif_ip4_addr(netif), &(autoip->llipaddr)))
350 && (autoip->state == AUTOIP_STATE_BOUND);
351 }
352
353 u8_t
autoip_accept_packet(struct netif * netif,const ip4_addr_t * addr)354 autoip_accept_packet(struct netif *netif, const ip4_addr_t *addr)
355 {
356 struct autoip *autoip = netif_autoip_data(netif);
357 return (autoip != NULL)
358 && (ip4_addr_cmp(addr, &(autoip->llipaddr)))
359 && (autoip->state == AUTOIP_STATE_BOUND);
360 }
361
362 #endif /* LWIP_IPV4 && LWIP_AUTOIP */
363