source: UsbWattMeter/trunk/lwip-1.4.1/src/core/dhcp.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
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1/**
2 * @file
3 * Dynamic Host Configuration Protocol client
4 *
5 */
6
7/*
8 *
9 * Copyright (c) 2001-2004 Leon Woestenberg <leon.woestenberg@gmx.net>
10 * Copyright (c) 2001-2004 Axon Digital Design B.V., The Netherlands.
11 * All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without modification,
14 * are permitted provided that the following conditions are met:
15 *
16 * 1. Redistributions of source code must retain the above copyright notice,
17 * this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright notice,
19 * this list of conditions and the following disclaimer in the documentation
20 * and/or other materials provided with the distribution.
21 * 3. The name of the author may not be used to endorse or promote products
22 * derived from this software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
25 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
26 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
27 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
28 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
29 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
32 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
33 * OF SUCH DAMAGE.
34 *
35 * This file is a contribution to the lwIP TCP/IP stack.
36 * The Swedish Institute of Computer Science and Adam Dunkels
37 * are specifically granted permission to redistribute this
38 * source code.
39 *
40 * Author: Leon Woestenberg <leon.woestenberg@gmx.net>
41 *
42 * This is a DHCP client for the lwIP TCP/IP stack. It aims to conform
43 * with RFC 2131 and RFC 2132.
44 *
45 * TODO:
46 * - Support for interfaces other than Ethernet (SLIP, PPP, ...)
47 *
48 * Please coordinate changes and requests with Leon Woestenberg
49 * <leon.woestenberg@gmx.net>
50 *
51 * Integration with your code:
52 *
53 * In lwip/dhcp.h
54 * #define DHCP_COARSE_TIMER_SECS (recommended 60 which is a minute)
55 * #define DHCP_FINE_TIMER_MSECS (recommended 500 which equals TCP coarse timer)
56 *
57 * Then have your application call dhcp_coarse_tmr() and
58 * dhcp_fine_tmr() on the defined intervals.
59 *
60 * dhcp_start(struct netif *netif);
61 * starts a DHCP client instance which configures the interface by
62 * obtaining an IP address lease and maintaining it.
63 *
64 * Use dhcp_release(netif) to end the lease and use dhcp_stop(netif)
65 * to remove the DHCP client.
66 *
67 */
68
69#include "lwip/opt.h"
70
71#if LWIP_DHCP /* don't build if not configured for use in lwipopts.h */
72
73#include "lwip/stats.h"
74#include "lwip/mem.h"
75#include "lwip/udp.h"
76#include "lwip/ip_addr.h"
77#include "lwip/netif.h"
78#include "lwip/def.h"
79#include "lwip/dhcp.h"
80#include "lwip/autoip.h"
81#include "lwip/dns.h"
82#include "netif/etharp.h"
83
84#include <string.h>
85
86/** DHCP_CREATE_RAND_XID: if this is set to 1, the xid is created using
87 * LWIP_RAND() (this overrides DHCP_GLOBAL_XID)
88 */
89#ifndef DHCP_CREATE_RAND_XID
90#define DHCP_CREATE_RAND_XID 1
91#endif
92
93/** Default for DHCP_GLOBAL_XID is 0xABCD0000
94 * This can be changed by defining DHCP_GLOBAL_XID and DHCP_GLOBAL_XID_HEADER, e.g.
95 * #define DHCP_GLOBAL_XID_HEADER "stdlib.h"
96 * #define DHCP_GLOBAL_XID rand()
97 */
98#ifdef DHCP_GLOBAL_XID_HEADER
99#include DHCP_GLOBAL_XID_HEADER /* include optional starting XID generation prototypes */
100#endif
101
102/** DHCP_OPTION_MAX_MSG_SIZE is set to the MTU
103 * MTU is checked to be big enough in dhcp_start */
104#define DHCP_MAX_MSG_LEN(netif) (netif->mtu)
105#define DHCP_MAX_MSG_LEN_MIN_REQUIRED 576
106/** Minimum length for reply before packet is parsed */
107#define DHCP_MIN_REPLY_LEN 44
108
109#define REBOOT_TRIES 2
110
111/** Option handling: options are parsed in dhcp_parse_reply
112 * and saved in an array where other functions can load them from.
113 * This might be moved into the struct dhcp (not necessarily since
114 * lwIP is single-threaded and the array is only used while in recv
115 * callback). */
116#define DHCP_OPTION_IDX_OVERLOAD 0
117#define DHCP_OPTION_IDX_MSG_TYPE 1
118#define DHCP_OPTION_IDX_SERVER_ID 2
119#define DHCP_OPTION_IDX_LEASE_TIME 3
120#define DHCP_OPTION_IDX_T1 4
121#define DHCP_OPTION_IDX_T2 5
122#define DHCP_OPTION_IDX_SUBNET_MASK 6
123#define DHCP_OPTION_IDX_ROUTER 7
124#define DHCP_OPTION_IDX_DNS_SERVER 8
125#define DHCP_OPTION_IDX_MAX (DHCP_OPTION_IDX_DNS_SERVER + DNS_MAX_SERVERS)
126
127/** Holds the decoded option values, only valid while in dhcp_recv.
128 @todo: move this into struct dhcp? */
129u32_t dhcp_rx_options_val[DHCP_OPTION_IDX_MAX];
130/** Holds a flag which option was received and is contained in dhcp_rx_options_val,
131 only valid while in dhcp_recv.
132 @todo: move this into struct dhcp? */
133u8_t dhcp_rx_options_given[DHCP_OPTION_IDX_MAX];
134
135#ifdef DHCP_GLOBAL_XID
136static u32_t xid;
137static u8_t xid_initialised;
138#endif /* DHCP_GLOBAL_XID */
139
140#define dhcp_option_given(dhcp, idx) (dhcp_rx_options_given[idx] != 0)
141#define dhcp_got_option(dhcp, idx) (dhcp_rx_options_given[idx] = 1)
142#define dhcp_clear_option(dhcp, idx) (dhcp_rx_options_given[idx] = 0)
143#define dhcp_clear_all_options(dhcp) (memset(dhcp_rx_options_given, 0, sizeof(dhcp_rx_options_given)))
144#define dhcp_get_option_value(dhcp, idx) (dhcp_rx_options_val[idx])
145#define dhcp_set_option_value(dhcp, idx, val) (dhcp_rx_options_val[idx] = (val))
146
147
148/* DHCP client state machine functions */
149static err_t dhcp_discover(struct netif *netif);
150static err_t dhcp_select(struct netif *netif);
151static void dhcp_bind(struct netif *netif);
152#if DHCP_DOES_ARP_CHECK
153static err_t dhcp_decline(struct netif *netif);
154#endif /* DHCP_DOES_ARP_CHECK */
155static err_t dhcp_rebind(struct netif *netif);
156static err_t dhcp_reboot(struct netif *netif);
157static void dhcp_set_state(struct dhcp *dhcp, u8_t new_state);
158
159/* receive, unfold, parse and free incoming messages */
160static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port);
161
162/* set the DHCP timers */
163static void dhcp_timeout(struct netif *netif);
164static void dhcp_t1_timeout(struct netif *netif);
165static void dhcp_t2_timeout(struct netif *netif);
166
167/* build outgoing messages */
168/* create a DHCP message, fill in common headers */
169static err_t dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type);
170/* free a DHCP request */
171static void dhcp_delete_msg(struct dhcp *dhcp);
172/* add a DHCP option (type, then length in bytes) */
173static void dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len);
174/* add option values */
175static void dhcp_option_byte(struct dhcp *dhcp, u8_t value);
176static void dhcp_option_short(struct dhcp *dhcp, u16_t value);
177static void dhcp_option_long(struct dhcp *dhcp, u32_t value);
178#if LWIP_NETIF_HOSTNAME
179static void dhcp_option_hostname(struct dhcp *dhcp, struct netif *netif);
180#endif /* LWIP_NETIF_HOSTNAME */
181/* always add the DHCP options trailer to end and pad */
182static void dhcp_option_trailer(struct dhcp *dhcp);
183
184/**
185 * Back-off the DHCP client (because of a received NAK response).
186 *
187 * Back-off the DHCP client because of a received NAK. Receiving a
188 * NAK means the client asked for something non-sensible, for
189 * example when it tries to renew a lease obtained on another network.
190 *
191 * We clear any existing set IP address and restart DHCP negotiation
192 * afresh (as per RFC2131 3.2.3).
193 *
194 * @param netif the netif under DHCP control
195 */
196static void
197dhcp_handle_nak(struct netif *netif)
198{
199 struct dhcp *dhcp = netif->dhcp;
200 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_nak(netif=%p) %c%c%"U16_F"\n",
201 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num));
202 /* Set the interface down since the address must no longer be used, as per RFC2131 */
203 netif_set_down(netif);
204 /* remove IP address from interface */
205 netif_set_ipaddr(netif, IP_ADDR_ANY);
206 netif_set_gw(netif, IP_ADDR_ANY);
207 netif_set_netmask(netif, IP_ADDR_ANY);
208 /* Change to a defined state */
209 dhcp_set_state(dhcp, DHCP_BACKING_OFF);
210 /* We can immediately restart discovery */
211 dhcp_discover(netif);
212}
213
214#if DHCP_DOES_ARP_CHECK
215/**
216 * Checks if the offered IP address is already in use.
217 *
218 * It does so by sending an ARP request for the offered address and
219 * entering CHECKING state. If no ARP reply is received within a small
220 * interval, the address is assumed to be free for use by us.
221 *
222 * @param netif the netif under DHCP control
223 */
224static void
225dhcp_check(struct netif *netif)
226{
227 struct dhcp *dhcp = netif->dhcp;
228 err_t result;
229 u16_t msecs;
230 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_check(netif=%p) %c%c\n", (void *)netif, (s16_t)netif->name[0],
231 (s16_t)netif->name[1]));
232 dhcp_set_state(dhcp, DHCP_CHECKING);
233 /* create an ARP query for the offered IP address, expecting that no host
234 responds, as the IP address should not be in use. */
235 result = etharp_query(netif, &dhcp->offered_ip_addr, NULL);
236 if (result != ERR_OK) {
237 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_check: could not perform ARP query\n"));
238 }
239 dhcp->tries++;
240 msecs = 500;
241 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
242 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_check(): set request timeout %"U16_F" msecs\n", msecs));
243}
244#endif /* DHCP_DOES_ARP_CHECK */
245
246/**
247 * Remember the configuration offered by a DHCP server.
248 *
249 * @param netif the netif under DHCP control
250 */
251static void
252dhcp_handle_offer(struct netif *netif)
253{
254 struct dhcp *dhcp = netif->dhcp;
255 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_offer(netif=%p) %c%c%"U16_F"\n",
256 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num));
257 /* obtain the server address */
258 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SERVER_ID)) {
259 ip4_addr_set_u32(&dhcp->server_ip_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SERVER_ID)));
260 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): server 0x%08"X32_F"\n",
261 ip4_addr_get_u32(&dhcp->server_ip_addr)));
262 /* remember offered address */
263 ip_addr_copy(dhcp->offered_ip_addr, dhcp->msg_in->yiaddr);
264 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): offer for 0x%08"X32_F"\n",
265 ip4_addr_get_u32(&dhcp->offered_ip_addr)));
266
267 dhcp_select(netif);
268 } else {
269 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
270 ("dhcp_handle_offer(netif=%p) did not get server ID!\n", (void*)netif));
271 }
272}
273
274/**
275 * Select a DHCP server offer out of all offers.
276 *
277 * Simply select the first offer received.
278 *
279 * @param netif the netif under DHCP control
280 * @return lwIP specific error (see error.h)
281 */
282static err_t
283dhcp_select(struct netif *netif)
284{
285 struct dhcp *dhcp = netif->dhcp;
286 err_t result;
287 u16_t msecs;
288
289 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_select(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num));
290 dhcp_set_state(dhcp, DHCP_REQUESTING);
291
292 /* create and initialize the DHCP message header */
293 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST);
294 if (result == ERR_OK) {
295 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
296 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif));
297
298 /* MUST request the offered IP address */
299 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
300 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
301
302 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4);
303 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->server_ip_addr)));
304
305 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/);
306 dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK);
307 dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER);
308 dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST);
309 dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER);
310
311#if LWIP_NETIF_HOSTNAME
312 dhcp_option_hostname(dhcp, netif);
313#endif /* LWIP_NETIF_HOSTNAME */
314
315 dhcp_option_trailer(dhcp);
316 /* shrink the pbuf to the actual content length */
317 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
318
319 /* send broadcast to any DHCP server */
320 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
321 dhcp_delete_msg(dhcp);
322 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_select: REQUESTING\n"));
323 } else {
324 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_select: could not allocate DHCP request\n"));
325 }
326 dhcp->tries++;
327 msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000;
328 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
329 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_select(): set request timeout %"U16_F" msecs\n", msecs));
330 return result;
331}
332
333/**
334 * The DHCP timer that checks for lease renewal/rebind timeouts.
335 */
336void
337dhcp_coarse_tmr()
338{
339 struct netif *netif = netif_list;
340 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n"));
341 /* iterate through all network interfaces */
342 while (netif != NULL) {
343 /* only act on DHCP configured interfaces */
344 if (netif->dhcp != NULL) {
345 /* timer is active (non zero), and triggers (zeroes) now? */
346 if (netif->dhcp->t2_timeout-- == 1) {
347 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t2 timeout\n"));
348 /* this clients' rebind timeout triggered */
349 dhcp_t2_timeout(netif);
350 /* timer is active (non zero), and triggers (zeroes) now */
351 } else if (netif->dhcp->t1_timeout-- == 1) {
352 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t1 timeout\n"));
353 /* this clients' renewal timeout triggered */
354 dhcp_t1_timeout(netif);
355 }
356 }
357 /* proceed to next netif */
358 netif = netif->next;
359 }
360}
361
362/**
363 * DHCP transaction timeout handling
364 *
365 * A DHCP server is expected to respond within a short period of time.
366 * This timer checks whether an outstanding DHCP request is timed out.
367 */
368void
369dhcp_fine_tmr()
370{
371 struct netif *netif = netif_list;
372 /* loop through netif's */
373 while (netif != NULL) {
374 /* only act on DHCP configured interfaces */
375 if (netif->dhcp != NULL) {
376 /* timer is active (non zero), and is about to trigger now */
377 if (netif->dhcp->request_timeout > 1) {
378 netif->dhcp->request_timeout--;
379 }
380 else if (netif->dhcp->request_timeout == 1) {
381 netif->dhcp->request_timeout--;
382 /* { netif->dhcp->request_timeout == 0 } */
383 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_fine_tmr(): request timeout\n"));
384 /* this client's request timeout triggered */
385 dhcp_timeout(netif);
386 }
387 }
388 /* proceed to next network interface */
389 netif = netif->next;
390 }
391}
392
393/**
394 * A DHCP negotiation transaction, or ARP request, has timed out.
395 *
396 * The timer that was started with the DHCP or ARP request has
397 * timed out, indicating no response was received in time.
398 *
399 * @param netif the netif under DHCP control
400 */
401static void
402dhcp_timeout(struct netif *netif)
403{
404 struct dhcp *dhcp = netif->dhcp;
405 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout()\n"));
406 /* back-off period has passed, or server selection timed out */
407 if ((dhcp->state == DHCP_BACKING_OFF) || (dhcp->state == DHCP_SELECTING)) {
408 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout(): restarting discovery\n"));
409 dhcp_discover(netif);
410 /* receiving the requested lease timed out */
411 } else if (dhcp->state == DHCP_REQUESTING) {
412 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, DHCP request timed out\n"));
413 if (dhcp->tries <= 5) {
414 dhcp_select(netif);
415 } else {
416 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, releasing, restarting\n"));
417 dhcp_release(netif);
418 dhcp_discover(netif);
419 }
420#if DHCP_DOES_ARP_CHECK
421 /* received no ARP reply for the offered address (which is good) */
422 } else if (dhcp->state == DHCP_CHECKING) {
423 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): CHECKING, ARP request timed out\n"));
424 if (dhcp->tries <= 1) {
425 dhcp_check(netif);
426 /* no ARP replies on the offered address,
427 looks like the IP address is indeed free */
428 } else {
429 /* bind the interface to the offered address */
430 dhcp_bind(netif);
431 }
432#endif /* DHCP_DOES_ARP_CHECK */
433 }
434 /* did not get response to renew request? */
435 else if (dhcp->state == DHCP_RENEWING) {
436 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): RENEWING, DHCP request timed out\n"));
437 /* just retry renewal */
438 /* note that the rebind timer will eventually time-out if renew does not work */
439 dhcp_renew(netif);
440 /* did not get response to rebind request? */
441 } else if (dhcp->state == DHCP_REBINDING) {
442 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REBINDING, DHCP request timed out\n"));
443 if (dhcp->tries <= 8) {
444 dhcp_rebind(netif);
445 } else {
446 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): RELEASING, DISCOVERING\n"));
447 dhcp_release(netif);
448 dhcp_discover(netif);
449 }
450 } else if (dhcp->state == DHCP_REBOOTING) {
451 if (dhcp->tries < REBOOT_TRIES) {
452 dhcp_reboot(netif);
453 } else {
454 dhcp_discover(netif);
455 }
456 }
457}
458
459/**
460 * The renewal period has timed out.
461 *
462 * @param netif the netif under DHCP control
463 */
464static void
465dhcp_t1_timeout(struct netif *netif)
466{
467 struct dhcp *dhcp = netif->dhcp;
468 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_t1_timeout()\n"));
469 if ((dhcp->state == DHCP_REQUESTING) || (dhcp->state == DHCP_BOUND) ||
470 (dhcp->state == DHCP_RENEWING)) {
471 /* just retry to renew - note that the rebind timer (t2) will
472 * eventually time-out if renew tries fail. */
473 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
474 ("dhcp_t1_timeout(): must renew\n"));
475 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state
476 DHCP_RENEWING, not DHCP_BOUND */
477 dhcp_renew(netif);
478 }
479}
480
481/**
482 * The rebind period has timed out.
483 *
484 * @param netif the netif under DHCP control
485 */
486static void
487dhcp_t2_timeout(struct netif *netif)
488{
489 struct dhcp *dhcp = netif->dhcp;
490 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t2_timeout()\n"));
491 if ((dhcp->state == DHCP_REQUESTING) || (dhcp->state == DHCP_BOUND) ||
492 (dhcp->state == DHCP_RENEWING)) {
493 /* just retry to rebind */
494 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
495 ("dhcp_t2_timeout(): must rebind\n"));
496 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state
497 DHCP_REBINDING, not DHCP_BOUND */
498 dhcp_rebind(netif);
499 }
500}
501
502/**
503 * Handle a DHCP ACK packet
504 *
505 * @param netif the netif under DHCP control
506 */
507static void
508dhcp_handle_ack(struct netif *netif)
509{
510 struct dhcp *dhcp = netif->dhcp;
511#if LWIP_DNS
512 u8_t n;
513#endif /* LWIP_DNS */
514
515 /* clear options we might not get from the ACK */
516 ip_addr_set_zero(&dhcp->offered_sn_mask);
517 ip_addr_set_zero(&dhcp->offered_gw_addr);
518#if LWIP_DHCP_BOOTP_FILE
519 ip_addr_set_zero(&dhcp->offered_si_addr);
520#endif /* LWIP_DHCP_BOOTP_FILE */
521
522 /* lease time given? */
523 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_LEASE_TIME)) {
524 /* remember offered lease time */
525 dhcp->offered_t0_lease = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_LEASE_TIME);
526 }
527 /* renewal period given? */
528 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T1)) {
529 /* remember given renewal period */
530 dhcp->offered_t1_renew = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T1);
531 } else {
532 /* calculate safe periods for renewal */
533 dhcp->offered_t1_renew = dhcp->offered_t0_lease / 2;
534 }
535
536 /* renewal period given? */
537 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T2)) {
538 /* remember given rebind period */
539 dhcp->offered_t2_rebind = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T2);
540 } else {
541 /* calculate safe periods for rebinding */
542 dhcp->offered_t2_rebind = dhcp->offered_t0_lease;
543 }
544
545 /* (y)our internet address */
546 ip_addr_copy(dhcp->offered_ip_addr, dhcp->msg_in->yiaddr);
547
548#if LWIP_DHCP_BOOTP_FILE
549 /* copy boot server address,
550 boot file name copied in dhcp_parse_reply if not overloaded */
551 ip_addr_copy(dhcp->offered_si_addr, dhcp->msg_in->siaddr);
552#endif /* LWIP_DHCP_BOOTP_FILE */
553
554 /* subnet mask given? */
555 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)) {
556 /* remember given subnet mask */
557 ip4_addr_set_u32(&dhcp->offered_sn_mask, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)));
558 dhcp->subnet_mask_given = 1;
559 } else {
560 dhcp->subnet_mask_given = 0;
561 }
562
563 /* gateway router */
564 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_ROUTER)) {
565 ip4_addr_set_u32(&dhcp->offered_gw_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_ROUTER)));
566 }
567
568#if LWIP_DNS
569 /* DNS servers */
570 n = 0;
571 while(dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n) && (n < DNS_MAX_SERVERS)) {
572 ip_addr_t dns_addr;
573 ip4_addr_set_u32(&dns_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n)));
574 dns_setserver(n, &dns_addr);
575 n++;
576 }
577#endif /* LWIP_DNS */
578}
579
580/** Set a statically allocated struct dhcp to work with.
581 * Using this prevents dhcp_start to allocate it using mem_malloc.
582 *
583 * @param netif the netif for which to set the struct dhcp
584 * @param dhcp (uninitialised) dhcp struct allocated by the application
585 */
586void
587dhcp_set_struct(struct netif *netif, struct dhcp *dhcp)
588{
589 LWIP_ASSERT("netif != NULL", netif != NULL);
590 LWIP_ASSERT("dhcp != NULL", dhcp != NULL);
591 LWIP_ASSERT("netif already has a struct dhcp set", netif->dhcp == NULL);
592
593 /* clear data structure */
594 memset(dhcp, 0, sizeof(struct dhcp));
595 /* dhcp_set_state(&dhcp, DHCP_OFF); */
596 netif->dhcp = dhcp;
597}
598
599/** Removes a struct dhcp from a netif.
600 *
601 * ATTENTION: Only use this when not using dhcp_set_struct() to allocate the
602 * struct dhcp since the memory is passed back to the heap.
603 *
604 * @param netif the netif from which to remove the struct dhcp
605 */
606void dhcp_cleanup(struct netif *netif)
607{
608 LWIP_ASSERT("netif != NULL", netif != NULL);
609
610 if (netif->dhcp != NULL) {
611 mem_free(netif->dhcp);
612 netif->dhcp = NULL;
613 }
614}
615
616/**
617 * Start DHCP negotiation for a network interface.
618 *
619 * If no DHCP client instance was attached to this interface,
620 * a new client is created first. If a DHCP client instance
621 * was already present, it restarts negotiation.
622 *
623 * @param netif The lwIP network interface
624 * @return lwIP error code
625 * - ERR_OK - No error
626 * - ERR_MEM - Out of memory
627 */
628err_t
629dhcp_start(struct netif *netif)
630{
631 struct dhcp *dhcp;
632 err_t result = ERR_OK;
633
634 LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;);
635 dhcp = netif->dhcp;
636 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num));
637 /* Remove the flag that says this netif is handled by DHCP,
638 it is set when we succeeded starting. */
639 netif->flags &= ~NETIF_FLAG_DHCP;
640
641 /* check hwtype of the netif */
642 if ((netif->flags & NETIF_FLAG_ETHARP) == 0) {
643 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): No ETHARP netif\n"));
644 return ERR_ARG;
645 }
646
647 /* check MTU of the netif */
648 if (netif->mtu < DHCP_MAX_MSG_LEN_MIN_REQUIRED) {
649 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): Cannot use this netif with DHCP: MTU is too small\n"));
650 return ERR_MEM;
651 }
652
653 /* no DHCP client attached yet? */
654 if (dhcp == NULL) {
655 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting new DHCP client\n"));
656 dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp));
657 if (dhcp == NULL) {
658 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n"));
659 return ERR_MEM;
660 }
661 /* store this dhcp client in the netif */
662 netif->dhcp = dhcp;
663 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): allocated dhcp"));
664 /* already has DHCP client attached */
665 } else {
666 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(): restarting DHCP configuration\n"));
667 if (dhcp->pcb != NULL) {
668 udp_remove(dhcp->pcb);
669 }
670 LWIP_ASSERT("pbuf p_out wasn't freed", dhcp->p_out == NULL);
671 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL );
672 }
673
674 /* clear data structure */
675 memset(dhcp, 0, sizeof(struct dhcp));
676 /* dhcp_set_state(&dhcp, DHCP_OFF); */
677 /* allocate UDP PCB */
678 dhcp->pcb = udp_new();
679 if (dhcp->pcb == NULL) {
680 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not obtain pcb\n"));
681 return ERR_MEM;
682 }
683 ip_set_option(dhcp->pcb, SOF_BROADCAST);
684 /* set up local and remote port for the pcb */
685 udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT);
686 udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT);
687 /* set up the recv callback and argument */
688 udp_recv(dhcp->pcb, dhcp_recv, netif);
689 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n"));
690 /* (re)start the DHCP negotiation */
691 result = dhcp_discover(netif);
692 if (result != ERR_OK) {
693 /* free resources allocated above */
694 dhcp_stop(netif);
695 return ERR_MEM;
696 }
697 /* Set the flag that says this netif is handled by DHCP. */
698 netif->flags |= NETIF_FLAG_DHCP;
699 return result;
700}
701
702/**
703 * Inform a DHCP server of our manual configuration.
704 *
705 * This informs DHCP servers of our fixed IP address configuration
706 * by sending an INFORM message. It does not involve DHCP address
707 * configuration, it is just here to be nice to the network.
708 *
709 * @param netif The lwIP network interface
710 */
711void
712dhcp_inform(struct netif *netif)
713{
714 struct dhcp dhcp;
715 err_t result = ERR_OK;
716 struct udp_pcb *pcb;
717
718 LWIP_ERROR("netif != NULL", (netif != NULL), return;);
719
720 memset(&dhcp, 0, sizeof(struct dhcp));
721 dhcp_set_state(&dhcp, DHCP_INFORM);
722
723 if ((netif->dhcp != NULL) && (netif->dhcp->pcb != NULL)) {
724 /* re-use existing pcb */
725 pcb = netif->dhcp->pcb;
726 } else {
727 pcb = udp_new();
728 if (pcb == NULL) {
729 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform(): could not obtain pcb"));
730 return;
731 }
732 dhcp.pcb = pcb;
733 ip_set_option(dhcp.pcb, SOF_BROADCAST);
734 udp_bind(dhcp.pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT);
735 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_inform(): created new udp pcb\n"));
736 }
737 /* create and initialize the DHCP message header */
738 result = dhcp_create_msg(netif, &dhcp, DHCP_INFORM);
739 if (result == ERR_OK) {
740 dhcp_option(&dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
741 dhcp_option_short(&dhcp, DHCP_MAX_MSG_LEN(netif));
742
743 dhcp_option_trailer(&dhcp);
744
745 pbuf_realloc(dhcp.p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp.options_out_len);
746
747 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n"));
748 udp_sendto_if(pcb, dhcp.p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
749 dhcp_delete_msg(&dhcp);
750 } else {
751 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform: could not allocate DHCP request\n"));
752 }
753
754 if (dhcp.pcb != NULL) {
755 /* otherwise, the existing pcb was used */
756 udp_remove(dhcp.pcb);
757 }
758}
759
760/** Handle a possible change in the network configuration.
761 *
762 * This enters the REBOOTING state to verify that the currently bound
763 * address is still valid.
764 */
765void
766dhcp_network_changed(struct netif *netif)
767{
768 struct dhcp *dhcp = netif->dhcp;
769 if (!dhcp)
770 return;
771 switch (dhcp->state) {
772 case DHCP_REBINDING:
773 case DHCP_RENEWING:
774 case DHCP_BOUND:
775 case DHCP_REBOOTING:
776 netif_set_down(netif);
777 dhcp->tries = 0;
778 dhcp_reboot(netif);
779 break;
780 case DHCP_OFF:
781 /* stay off */
782 break;
783 default:
784 dhcp->tries = 0;
785#if LWIP_DHCP_AUTOIP_COOP
786 if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
787 autoip_stop(netif);
788 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
789 }
790#endif /* LWIP_DHCP_AUTOIP_COOP */
791 dhcp_discover(netif);
792 break;
793 }
794}
795
796#if DHCP_DOES_ARP_CHECK
797/**
798 * Match an ARP reply with the offered IP address.
799 *
800 * @param netif the network interface on which the reply was received
801 * @param addr The IP address we received a reply from
802 */
803void dhcp_arp_reply(struct netif *netif, ip_addr_t *addr)
804{
805 LWIP_ERROR("netif != NULL", (netif != NULL), return;);
806 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_arp_reply()\n"));
807 /* is a DHCP client doing an ARP check? */
808 if ((netif->dhcp != NULL) && (netif->dhcp->state == DHCP_CHECKING)) {
809 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_arp_reply(): CHECKING, arp reply for 0x%08"X32_F"\n",
810 ip4_addr_get_u32(addr)));
811 /* did a host respond with the address we
812 were offered by the DHCP server? */
813 if (ip_addr_cmp(addr, &netif->dhcp->offered_ip_addr)) {
814 /* we will not accept the offered address */
815 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
816 ("dhcp_arp_reply(): arp reply matched with offered address, declining\n"));
817 dhcp_decline(netif);
818 }
819 }
820}
821
822/**
823 * Decline an offered lease.
824 *
825 * Tell the DHCP server we do not accept the offered address.
826 * One reason to decline the lease is when we find out the address
827 * is already in use by another host (through ARP).
828 *
829 * @param netif the netif under DHCP control
830 */
831static err_t
832dhcp_decline(struct netif *netif)
833{
834 struct dhcp *dhcp = netif->dhcp;
835 err_t result = ERR_OK;
836 u16_t msecs;
837 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline()\n"));
838 dhcp_set_state(dhcp, DHCP_BACKING_OFF);
839 /* create and initialize the DHCP message header */
840 result = dhcp_create_msg(netif, dhcp, DHCP_DECLINE);
841 if (result == ERR_OK) {
842 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
843 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
844
845 dhcp_option_trailer(dhcp);
846 /* resize pbuf to reflect true size of options */
847 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
848
849 /* per section 4.4.4, broadcast DECLINE messages */
850 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
851 dhcp_delete_msg(dhcp);
852 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_decline: BACKING OFF\n"));
853 } else {
854 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
855 ("dhcp_decline: could not allocate DHCP request\n"));
856 }
857 dhcp->tries++;
858 msecs = 10*1000;
859 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
860 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs));
861 return result;
862}
863#endif /* DHCP_DOES_ARP_CHECK */
864
865
866/**
867 * Start the DHCP process, discover a DHCP server.
868 *
869 * @param netif the netif under DHCP control
870 */
871static err_t
872dhcp_discover(struct netif *netif)
873{
874 struct dhcp *dhcp = netif->dhcp;
875 err_t result = ERR_OK;
876 u16_t msecs;
877 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover()\n"));
878 ip_addr_set_any(&dhcp->offered_ip_addr);
879 dhcp_set_state(dhcp, DHCP_SELECTING);
880 /* create and initialize the DHCP message header */
881 result = dhcp_create_msg(netif, dhcp, DHCP_DISCOVER);
882 if (result == ERR_OK) {
883 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n"));
884
885 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
886 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif));
887
888 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/);
889 dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK);
890 dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER);
891 dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST);
892 dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER);
893
894 dhcp_option_trailer(dhcp);
895
896 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: realloc()ing\n"));
897 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
898
899 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, DHCP_SERVER_PORT)\n"));
900 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
901 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()ing\n"));
902 dhcp_delete_msg(dhcp);
903 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover: SELECTING\n"));
904 } else {
905 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_discover: could not allocate DHCP request\n"));
906 }
907 dhcp->tries++;
908#if LWIP_DHCP_AUTOIP_COOP
909 if(dhcp->tries >= LWIP_DHCP_AUTOIP_COOP_TRIES && dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_OFF) {
910 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_ON;
911 autoip_start(netif);
912 }
913#endif /* LWIP_DHCP_AUTOIP_COOP */
914 msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000;
915 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
916 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs));
917 return result;
918}
919
920
921/**
922 * Bind the interface to the offered IP address.
923 *
924 * @param netif network interface to bind to the offered address
925 */
926static void
927dhcp_bind(struct netif *netif)
928{
929 u32_t timeout;
930 struct dhcp *dhcp;
931 ip_addr_t sn_mask, gw_addr;
932 LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;);
933 dhcp = netif->dhcp;
934 LWIP_ERROR("dhcp_bind: dhcp != NULL", (dhcp != NULL), return;);
935 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num));
936
937 /* temporary DHCP lease? */
938 if (dhcp->offered_t1_renew != 0xffffffffUL) {
939 /* set renewal period timer */
940 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew));
941 timeout = (dhcp->offered_t1_renew + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS;
942 if(timeout > 0xffff) {
943 timeout = 0xffff;
944 }
945 dhcp->t1_timeout = (u16_t)timeout;
946 if (dhcp->t1_timeout == 0) {
947 dhcp->t1_timeout = 1;
948 }
949 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew*1000));
950 }
951 /* set renewal period timer */
952 if (dhcp->offered_t2_rebind != 0xffffffffUL) {
953 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind));
954 timeout = (dhcp->offered_t2_rebind + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS;
955 if(timeout > 0xffff) {
956 timeout = 0xffff;
957 }
958 dhcp->t2_timeout = (u16_t)timeout;
959 if (dhcp->t2_timeout == 0) {
960 dhcp->t2_timeout = 1;
961 }
962 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t2_rebind*1000));
963 }
964
965 /* If we have sub 1 minute lease, t2 and t1 will kick in at the same time. */
966 if ((dhcp->t1_timeout >= dhcp->t2_timeout) && (dhcp->t2_timeout > 0)) {
967 dhcp->t1_timeout = 0;
968 }
969
970 if (dhcp->subnet_mask_given) {
971 /* copy offered network mask */
972 ip_addr_copy(sn_mask, dhcp->offered_sn_mask);
973 } else {
974 /* subnet mask not given, choose a safe subnet mask given the network class */
975 u8_t first_octet = ip4_addr1(&dhcp->offered_ip_addr);
976 if (first_octet <= 127) {
977 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xff000000UL));
978 } else if (first_octet >= 192) {
979 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffffff00UL));
980 } else {
981 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffff0000UL));
982 }
983 }
984
985 ip_addr_copy(gw_addr, dhcp->offered_gw_addr);
986 /* gateway address not given? */
987 if (ip_addr_isany(&gw_addr)) {
988 /* copy network address */
989 ip_addr_get_network(&gw_addr, &dhcp->offered_ip_addr, &sn_mask);
990 /* use first host address on network as gateway */
991 ip4_addr_set_u32(&gw_addr, ip4_addr_get_u32(&gw_addr) | PP_HTONL(0x00000001UL));
992 }
993
994#if LWIP_DHCP_AUTOIP_COOP
995 if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
996 autoip_stop(netif);
997 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
998 }
999#endif /* LWIP_DHCP_AUTOIP_COOP */
1000
1001 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): IP: 0x%08"X32_F"\n",
1002 ip4_addr_get_u32(&dhcp->offered_ip_addr)));
1003 netif_set_ipaddr(netif, &dhcp->offered_ip_addr);
1004 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): SN: 0x%08"X32_F"\n",
1005 ip4_addr_get_u32(&sn_mask)));
1006 netif_set_netmask(netif, &sn_mask);
1007 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): GW: 0x%08"X32_F"\n",
1008 ip4_addr_get_u32(&gw_addr)));
1009 netif_set_gw(netif, &gw_addr);
1010 /* bring the interface up */
1011 netif_set_up(netif);
1012 /* netif is now bound to DHCP leased address */
1013 dhcp_set_state(dhcp, DHCP_BOUND);
1014}
1015
1016/**
1017 * Renew an existing DHCP lease at the involved DHCP server.
1018 *
1019 * @param netif network interface which must renew its lease
1020 */
1021err_t
1022dhcp_renew(struct netif *netif)
1023{
1024 struct dhcp *dhcp = netif->dhcp;
1025 err_t result;
1026 u16_t msecs;
1027 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_renew()\n"));
1028 dhcp_set_state(dhcp, DHCP_RENEWING);
1029
1030 /* create and initialize the DHCP message header */
1031 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST);
1032 if (result == ERR_OK) {
1033 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1034 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif));
1035
1036#if 0
1037 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
1038 dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr));
1039#endif
1040
1041#if 0
1042 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4);
1043 dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr));
1044#endif
1045
1046#if LWIP_NETIF_HOSTNAME
1047 dhcp_option_hostname(dhcp, netif);
1048#endif /* LWIP_NETIF_HOSTNAME */
1049
1050 /* append DHCP message trailer */
1051 dhcp_option_trailer(dhcp);
1052
1053 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
1054
1055 udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif);
1056 dhcp_delete_msg(dhcp);
1057
1058 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew: RENEWING\n"));
1059 } else {
1060 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_renew: could not allocate DHCP request\n"));
1061 }
1062 dhcp->tries++;
1063 /* back-off on retries, but to a maximum of 20 seconds */
1064 msecs = dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000;
1065 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
1066 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs));
1067 return result;
1068}
1069
1070/**
1071 * Rebind with a DHCP server for an existing DHCP lease.
1072 *
1073 * @param netif network interface which must rebind with a DHCP server
1074 */
1075static err_t
1076dhcp_rebind(struct netif *netif)
1077{
1078 struct dhcp *dhcp = netif->dhcp;
1079 err_t result;
1080 u16_t msecs;
1081 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n"));
1082 dhcp_set_state(dhcp, DHCP_REBINDING);
1083
1084 /* create and initialize the DHCP message header */
1085 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST);
1086 if (result == ERR_OK) {
1087 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1088 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif));
1089
1090#if LWIP_NETIF_HOSTNAME
1091 dhcp_option_hostname(dhcp, netif);
1092#endif /* LWIP_NETIF_HOSTNAME */
1093
1094#if 0
1095 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
1096 dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr));
1097
1098 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4);
1099 dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr));
1100#endif
1101
1102 dhcp_option_trailer(dhcp);
1103
1104 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
1105
1106 /* broadcast to server */
1107 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
1108 dhcp_delete_msg(dhcp);
1109 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n"));
1110 } else {
1111 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_rebind: could not allocate DHCP request\n"));
1112 }
1113 dhcp->tries++;
1114 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000;
1115 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
1116 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs));
1117 return result;
1118}
1119
1120/**
1121 * Enter REBOOTING state to verify an existing lease
1122 *
1123 * @param netif network interface which must reboot
1124 */
1125static err_t
1126dhcp_reboot(struct netif *netif)
1127{
1128 struct dhcp *dhcp = netif->dhcp;
1129 err_t result;
1130 u16_t msecs;
1131 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n"));
1132 dhcp_set_state(dhcp, DHCP_REBOOTING);
1133
1134 /* create and initialize the DHCP message header */
1135 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST);
1136 if (result == ERR_OK) {
1137 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1138 dhcp_option_short(dhcp, 576);
1139
1140 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
1141 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
1142
1143 dhcp_option_trailer(dhcp);
1144
1145 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
1146
1147 /* broadcast to server */
1148 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
1149 dhcp_delete_msg(dhcp);
1150 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot: REBOOTING\n"));
1151 } else {
1152 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_reboot: could not allocate DHCP request\n"));
1153 }
1154 dhcp->tries++;
1155 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000;
1156 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
1157 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot(): set request timeout %"U16_F" msecs\n", msecs));
1158 return result;
1159}
1160
1161
1162/**
1163 * Release a DHCP lease.
1164 *
1165 * @param netif network interface which must release its lease
1166 */
1167err_t
1168dhcp_release(struct netif *netif)
1169{
1170 struct dhcp *dhcp = netif->dhcp;
1171 err_t result;
1172 u16_t msecs;
1173 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release()\n"));
1174
1175 /* idle DHCP client */
1176 dhcp_set_state(dhcp, DHCP_OFF);
1177 /* clean old DHCP offer */
1178 ip_addr_set_zero(&dhcp->server_ip_addr);
1179 ip_addr_set_zero(&dhcp->offered_ip_addr);
1180 ip_addr_set_zero(&dhcp->offered_sn_mask);
1181 ip_addr_set_zero(&dhcp->offered_gw_addr);
1182#if LWIP_DHCP_BOOTP_FILE
1183 ip_addr_set_zero(&dhcp->offered_si_addr);
1184#endif /* LWIP_DHCP_BOOTP_FILE */
1185 dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0;
1186
1187 /* create and initialize the DHCP message header */
1188 result = dhcp_create_msg(netif, dhcp, DHCP_RELEASE);
1189 if (result == ERR_OK) {
1190 dhcp_option_trailer(dhcp);
1191
1192 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
1193
1194 udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif);
1195 dhcp_delete_msg(dhcp);
1196 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_OFF\n"));
1197 } else {
1198 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n"));
1199 }
1200 dhcp->tries++;
1201 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000;
1202 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
1203 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release(): set request timeout %"U16_F" msecs\n", msecs));
1204 /* bring the interface down */
1205 netif_set_down(netif);
1206 /* remove IP address from interface */
1207 netif_set_ipaddr(netif, IP_ADDR_ANY);
1208 netif_set_gw(netif, IP_ADDR_ANY);
1209 netif_set_netmask(netif, IP_ADDR_ANY);
1210
1211 return result;
1212}
1213
1214/**
1215 * Remove the DHCP client from the interface.
1216 *
1217 * @param netif The network interface to stop DHCP on
1218 */
1219void
1220dhcp_stop(struct netif *netif)
1221{
1222 struct dhcp *dhcp;
1223 LWIP_ERROR("dhcp_stop: netif != NULL", (netif != NULL), return;);
1224 dhcp = netif->dhcp;
1225 /* Remove the flag that says this netif is handled by DHCP. */
1226 netif->flags &= ~NETIF_FLAG_DHCP;
1227
1228 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_stop()\n"));
1229 /* netif is DHCP configured? */
1230 if (dhcp != NULL) {
1231#if LWIP_DHCP_AUTOIP_COOP
1232 if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
1233 autoip_stop(netif);
1234 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
1235 }
1236#endif /* LWIP_DHCP_AUTOIP_COOP */
1237
1238 if (dhcp->pcb != NULL) {
1239 udp_remove(dhcp->pcb);
1240 dhcp->pcb = NULL;
1241 }
1242 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL);
1243 dhcp_set_state(dhcp, DHCP_OFF);
1244 }
1245}
1246
1247/*
1248 * Set the DHCP state of a DHCP client.
1249 *
1250 * If the state changed, reset the number of tries.
1251 */
1252static void
1253dhcp_set_state(struct dhcp *dhcp, u8_t new_state)
1254{
1255 if (new_state != dhcp->state) {
1256 dhcp->state = new_state;
1257 dhcp->tries = 0;
1258 dhcp->request_timeout = 0;
1259 }
1260}
1261
1262/*
1263 * Concatenate an option type and length field to the outgoing
1264 * DHCP message.
1265 *
1266 */
1267static void
1268dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len)
1269{
1270 LWIP_ASSERT("dhcp_option: dhcp->options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN);
1271 dhcp->msg_out->options[dhcp->options_out_len++] = option_type;
1272 dhcp->msg_out->options[dhcp->options_out_len++] = option_len;
1273}
1274/*
1275 * Concatenate a single byte to the outgoing DHCP message.
1276 *
1277 */
1278static void
1279dhcp_option_byte(struct dhcp *dhcp, u8_t value)
1280{
1281 LWIP_ASSERT("dhcp_option_byte: dhcp->options_out_len < DHCP_OPTIONS_LEN", dhcp->options_out_len < DHCP_OPTIONS_LEN);
1282 dhcp->msg_out->options[dhcp->options_out_len++] = value;
1283}
1284
1285static void
1286dhcp_option_short(struct dhcp *dhcp, u16_t value)
1287{
1288 LWIP_ASSERT("dhcp_option_short: dhcp->options_out_len + 2 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U <= DHCP_OPTIONS_LEN);
1289 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff00U) >> 8);
1290 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t) (value & 0x00ffU);
1291}
1292
1293static void
1294dhcp_option_long(struct dhcp *dhcp, u32_t value)
1295{
1296 LWIP_ASSERT("dhcp_option_long: dhcp->options_out_len + 4 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 4U <= DHCP_OPTIONS_LEN);
1297 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24);
1298 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16);
1299 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8);
1300 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x000000ffUL));
1301}
1302
1303#if LWIP_NETIF_HOSTNAME
1304static void
1305dhcp_option_hostname(struct dhcp *dhcp, struct netif *netif)
1306{
1307 if (netif->hostname != NULL) {
1308 size_t namelen = strlen(netif->hostname);
1309 if (namelen > 0) {
1310 u8_t len;
1311 const char *p = netif->hostname;
1312 /* Shrink len to available bytes (need 2 bytes for OPTION_HOSTNAME
1313 and 1 byte for trailer) */
1314 size_t available = DHCP_OPTIONS_LEN - dhcp->options_out_len - 3;
1315 LWIP_ASSERT("DHCP: hostname is too long!", namelen <= available);
1316 len = LWIP_MIN(namelen, available);
1317 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, len);
1318 while (len--) {
1319 dhcp_option_byte(dhcp, *p++);
1320 }
1321 }
1322 }
1323}
1324#endif /* LWIP_NETIF_HOSTNAME */
1325
1326/**
1327 * Extract the DHCP message and the DHCP options.
1328 *
1329 * Extract the DHCP message and the DHCP options, each into a contiguous
1330 * piece of memory. As a DHCP message is variable sized by its options,
1331 * and also allows overriding some fields for options, the easy approach
1332 * is to first unfold the options into a conitguous piece of memory, and
1333 * use that further on.
1334 *
1335 */
1336static err_t
1337dhcp_parse_reply(struct dhcp *dhcp, struct pbuf *p)
1338{
1339 u8_t *options;
1340 u16_t offset;
1341 u16_t offset_max;
1342 u16_t options_idx;
1343 u16_t options_idx_max;
1344 struct pbuf *q;
1345 int parse_file_as_options = 0;
1346 int parse_sname_as_options = 0;
1347
1348 /* clear received options */
1349 dhcp_clear_all_options(dhcp);
1350 /* check that beginning of dhcp_msg (up to and including chaddr) is in first pbuf */
1351 if (p->len < DHCP_SNAME_OFS) {
1352 return ERR_BUF;
1353 }
1354 dhcp->msg_in = (struct dhcp_msg *)p->payload;
1355#if LWIP_DHCP_BOOTP_FILE
1356 /* clear boot file name */
1357 dhcp->boot_file_name[0] = 0;
1358#endif /* LWIP_DHCP_BOOTP_FILE */
1359
1360 /* parse options */
1361
1362 /* start with options field */
1363 options_idx = DHCP_OPTIONS_OFS;
1364 /* parse options to the end of the received packet */
1365 options_idx_max = p->tot_len;
1366again:
1367 q = p;
1368 while((q != NULL) && (options_idx >= q->len)) {
1369 options_idx -= q->len;
1370 options_idx_max -= q->len;
1371 q = q->next;
1372 }
1373 if (q == NULL) {
1374 return ERR_BUF;
1375 }
1376 offset = options_idx;
1377 offset_max = options_idx_max;
1378 options = (u8_t*)q->payload;
1379 /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */
1380 while((q != NULL) && (options[offset] != DHCP_OPTION_END) && (offset < offset_max)) {
1381 u8_t op = options[offset];
1382 u8_t len;
1383 u8_t decode_len = 0;
1384 int decode_idx = -1;
1385 u16_t val_offset = offset + 2;
1386 /* len byte might be in the next pbuf */
1387 if (offset + 1 < q->len) {
1388 len = options[offset + 1];
1389 } else {
1390 len = (q->next != NULL ? ((u8_t*)q->next->payload)[0] : 0);
1391 }
1392 /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F, msg_offset, q->len)); */
1393 decode_len = len;
1394 switch(op) {
1395 /* case(DHCP_OPTION_END): handled above */
1396 case(DHCP_OPTION_PAD):
1397 /* special option: no len encoded */
1398 decode_len = len = 0;
1399 /* will be increased below */
1400 offset--;
1401 break;
1402 case(DHCP_OPTION_SUBNET_MASK):
1403 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;);
1404 decode_idx = DHCP_OPTION_IDX_SUBNET_MASK;
1405 break;
1406 case(DHCP_OPTION_ROUTER):
1407 decode_len = 4; /* only copy the first given router */
1408 LWIP_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;);
1409 decode_idx = DHCP_OPTION_IDX_ROUTER;
1410 break;
1411 case(DHCP_OPTION_DNS_SERVER):
1412 /* special case: there might be more than one server */
1413 LWIP_ERROR("len % 4 == 0", len % 4 == 0, return ERR_VAL;);
1414 /* limit number of DNS servers */
1415 decode_len = LWIP_MIN(len, 4 * DNS_MAX_SERVERS);
1416 LWIP_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;);
1417 decode_idx = DHCP_OPTION_IDX_DNS_SERVER;
1418 break;
1419 case(DHCP_OPTION_LEASE_TIME):
1420 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;);
1421 decode_idx = DHCP_OPTION_IDX_LEASE_TIME;
1422 break;
1423 case(DHCP_OPTION_OVERLOAD):
1424 LWIP_ERROR("len == 1", len == 1, return ERR_VAL;);
1425 decode_idx = DHCP_OPTION_IDX_OVERLOAD;
1426 break;
1427 case(DHCP_OPTION_MESSAGE_TYPE):
1428 LWIP_ERROR("len == 1", len == 1, return ERR_VAL;);
1429 decode_idx = DHCP_OPTION_IDX_MSG_TYPE;
1430 break;
1431 case(DHCP_OPTION_SERVER_ID):
1432 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;);
1433 decode_idx = DHCP_OPTION_IDX_SERVER_ID;
1434 break;
1435 case(DHCP_OPTION_T1):
1436 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;);
1437 decode_idx = DHCP_OPTION_IDX_T1;
1438 break;
1439 case(DHCP_OPTION_T2):
1440 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;);
1441 decode_idx = DHCP_OPTION_IDX_T2;
1442 break;
1443 default:
1444 decode_len = 0;
1445 LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", op));
1446 break;
1447 }
1448 offset += len + 2;
1449 if (decode_len > 0) {
1450 u32_t value = 0;
1451 u16_t copy_len;
1452decode_next:
1453 LWIP_ASSERT("check decode_idx", decode_idx >= 0 && decode_idx < DHCP_OPTION_IDX_MAX);
1454 if (!dhcp_option_given(dhcp, decode_idx)) {
1455 copy_len = LWIP_MIN(decode_len, 4);
1456 pbuf_copy_partial(q, &value, copy_len, val_offset);
1457 if (decode_len > 4) {
1458 /* decode more than one u32_t */
1459 LWIP_ERROR("decode_len % 4 == 0", decode_len % 4 == 0, return ERR_VAL;);
1460 dhcp_got_option(dhcp, decode_idx);
1461 dhcp_set_option_value(dhcp, decode_idx, htonl(value));
1462 decode_len -= 4;
1463 val_offset += 4;
1464 decode_idx++;
1465 goto decode_next;
1466 } else if (decode_len == 4) {
1467 value = ntohl(value);
1468 } else {
1469 LWIP_ERROR("invalid decode_len", decode_len == 1, return ERR_VAL;);
1470 value = ((u8_t*)&value)[0];
1471 }
1472 dhcp_got_option(dhcp, decode_idx);
1473 dhcp_set_option_value(dhcp, decode_idx, value);
1474 }
1475 }
1476 if (offset >= q->len) {
1477 offset -= q->len;
1478 offset_max -= q->len;
1479 if ((offset < offset_max) && offset_max) {
1480 q = q->next;
1481 LWIP_ASSERT("next pbuf was null", q);
1482 options = (u8_t*)q->payload;
1483 } else {
1484 // We've run out of bytes, probably no end marker. Don't proceed.
1485 break;
1486 }
1487 }
1488 }
1489 /* is this an overloaded message? */
1490 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_OVERLOAD)) {
1491 u32_t overload = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_OVERLOAD);
1492 dhcp_clear_option(dhcp, DHCP_OPTION_IDX_OVERLOAD);
1493 if (overload == DHCP_OVERLOAD_FILE) {
1494 parse_file_as_options = 1;
1495 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded file field\n"));
1496 } else if (overload == DHCP_OVERLOAD_SNAME) {
1497 parse_sname_as_options = 1;
1498 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname field\n"));
1499 } else if (overload == DHCP_OVERLOAD_SNAME_FILE) {
1500 parse_sname_as_options = 1;
1501 parse_file_as_options = 1;
1502 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname and file field\n"));
1503 } else {
1504 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("invalid overload option: %d\n", (int)overload));
1505 }
1506#if LWIP_DHCP_BOOTP_FILE
1507 if (!parse_file_as_options) {
1508 /* only do this for ACK messages */
1509 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) &&
1510 (dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK))
1511 /* copy bootp file name, don't care for sname (server hostname) */
1512 pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS);
1513 /* make sure the string is really NULL-terminated */
1514 dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0;
1515 }
1516#endif /* LWIP_DHCP_BOOTP_FILE */
1517 }
1518 if (parse_file_as_options) {
1519 /* if both are overloaded, parse file first and then sname (RFC 2131 ch. 4.1) */
1520 parse_file_as_options = 0;
1521 options_idx = DHCP_FILE_OFS;
1522 options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN;
1523 goto again;
1524 } else if (parse_sname_as_options) {
1525 parse_sname_as_options = 0;
1526 options_idx = DHCP_SNAME_OFS;
1527 options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN;
1528 goto again;
1529 }
1530 return ERR_OK;
1531}
1532
1533/**
1534 * If an incoming DHCP message is in response to us, then trigger the state machine
1535 */
1536static void
1537dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port)
1538{
1539 struct netif *netif = (struct netif *)arg;
1540 struct dhcp *dhcp = netif->dhcp;
1541 struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload;
1542 u8_t msg_type;
1543 u8_t i;
1544 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_recv(pbuf = %p) from DHCP server %"U16_F".%"U16_F".%"U16_F".%"U16_F" port %"U16_F"\n", (void*)p,
1545 ip4_addr1_16(addr), ip4_addr2_16(addr), ip4_addr3_16(addr), ip4_addr4_16(addr), port));
1546 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len));
1547 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len));
1548 /* prevent warnings about unused arguments */
1549 LWIP_UNUSED_ARG(pcb);
1550 LWIP_UNUSED_ARG(addr);
1551 LWIP_UNUSED_ARG(port);
1552
1553 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL);
1554
1555 if (p->len < DHCP_MIN_REPLY_LEN) {
1556 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP reply message or pbuf too short\n"));
1557 goto free_pbuf_and_return;
1558 }
1559
1560 if (reply_msg->op != DHCP_BOOTREPLY) {
1561 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("not a DHCP reply message, but type %"U16_F"\n", (u16_t)reply_msg->op));
1562 goto free_pbuf_and_return;
1563 }
1564 /* iterate through hardware address and match against DHCP message */
1565 for (i = 0; i < netif->hwaddr_len; i++) {
1566 if (netif->hwaddr[i] != reply_msg->chaddr[i]) {
1567 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
1568 ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n",
1569 (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i]));
1570 goto free_pbuf_and_return;
1571 }
1572 }
1573 /* match transaction ID against what we expected */
1574 if (ntohl(reply_msg->xid) != dhcp->xid) {
1575 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
1576 ("transaction id mismatch reply_msg->xid(%"X32_F")!=dhcp->xid(%"X32_F")\n",ntohl(reply_msg->xid),dhcp->xid));
1577 goto free_pbuf_and_return;
1578 }
1579 /* option fields could be unfold? */
1580 if (dhcp_parse_reply(dhcp, p) != ERR_OK) {
1581 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
1582 ("problem unfolding DHCP message - too short on memory?\n"));
1583 goto free_pbuf_and_return;
1584 }
1585
1586 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n"));
1587 /* obtain pointer to DHCP message type */
1588 if (!dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE)) {
1589 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP_OPTION_MESSAGE_TYPE option not found\n"));
1590 goto free_pbuf_and_return;
1591 }
1592
1593 /* read DHCP message type */
1594 msg_type = (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE);
1595 /* message type is DHCP ACK? */
1596 if (msg_type == DHCP_ACK) {
1597 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_ACK received\n"));
1598 /* in requesting state? */
1599 if (dhcp->state == DHCP_REQUESTING) {
1600 dhcp_handle_ack(netif);
1601#if DHCP_DOES_ARP_CHECK
1602 /* check if the acknowledged lease address is already in use */
1603 dhcp_check(netif);
1604#else
1605 /* bind interface to the acknowledged lease address */
1606 dhcp_bind(netif);
1607#endif
1608 }
1609 /* already bound to the given lease address? */
1610 else if ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING)) {
1611 dhcp_bind(netif);
1612 }
1613 }
1614 /* received a DHCP_NAK in appropriate state? */
1615 else if ((msg_type == DHCP_NAK) &&
1616 ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REQUESTING) ||
1617 (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING ))) {
1618 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_NAK received\n"));
1619 dhcp_handle_nak(netif);
1620 }
1621 /* received a DHCP_OFFER in DHCP_SELECTING state? */
1622 else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_SELECTING)) {
1623 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_OFFER received in DHCP_SELECTING state\n"));
1624 dhcp->request_timeout = 0;
1625 /* remember offered lease */
1626 dhcp_handle_offer(netif);
1627 }
1628free_pbuf_and_return:
1629 dhcp->msg_in = NULL;
1630 pbuf_free(p);
1631}
1632
1633/**
1634 * Create a DHCP request, fill in common headers
1635 *
1636 * @param netif the netif under DHCP control
1637 * @param dhcp dhcp control struct
1638 * @param message_type message type of the request
1639 */
1640static err_t
1641dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type)
1642{
1643 u16_t i;
1644#ifndef DHCP_GLOBAL_XID
1645 /** default global transaction identifier starting value (easy to match
1646 * with a packet analyser). We simply increment for each new request.
1647 * Predefine DHCP_GLOBAL_XID to a better value or a function call to generate one
1648 * at runtime, any supporting function prototypes can be defined in DHCP_GLOBAL_XID_HEADER */
1649#if DHCP_CREATE_RAND_XID && defined(LWIP_RAND)
1650 static u32_t xid;
1651#else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1652 static u32_t xid = 0xABCD0000;
1653#endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1654#else
1655 if (!xid_initialised) {
1656 xid = DHCP_GLOBAL_XID;
1657 xid_initialised = !xid_initialised;
1658 }
1659#endif
1660 LWIP_ERROR("dhcp_create_msg: netif != NULL", (netif != NULL), return ERR_ARG;);
1661 LWIP_ERROR("dhcp_create_msg: dhcp != NULL", (dhcp != NULL), return ERR_VAL;);
1662 LWIP_ASSERT("dhcp_create_msg: dhcp->p_out == NULL", dhcp->p_out == NULL);
1663 LWIP_ASSERT("dhcp_create_msg: dhcp->msg_out == NULL", dhcp->msg_out == NULL);
1664 dhcp->p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM);
1665 if (dhcp->p_out == NULL) {
1666 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
1667 ("dhcp_create_msg(): could not allocate pbuf\n"));
1668 return ERR_MEM;
1669 }
1670 LWIP_ASSERT("dhcp_create_msg: check that first pbuf can hold struct dhcp_msg",
1671 (dhcp->p_out->len >= sizeof(struct dhcp_msg)));
1672
1673 /* reuse transaction identifier in retransmissions */
1674 if (dhcp->tries == 0) {
1675#if DHCP_CREATE_RAND_XID && defined(LWIP_RAND)
1676 xid = LWIP_RAND();
1677#else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1678 xid++;
1679#endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1680 }
1681 dhcp->xid = xid;
1682 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE,
1683 ("transaction id xid(%"X32_F")\n", xid));
1684
1685 dhcp->msg_out = (struct dhcp_msg *)dhcp->p_out->payload;
1686
1687 dhcp->msg_out->op = DHCP_BOOTREQUEST;
1688 /* TODO: make link layer independent */
1689 dhcp->msg_out->htype = DHCP_HTYPE_ETH;
1690 dhcp->msg_out->hlen = netif->hwaddr_len;
1691 dhcp->msg_out->hops = 0;
1692 dhcp->msg_out->xid = htonl(dhcp->xid);
1693 dhcp->msg_out->secs = 0;
1694 /* we don't need the broadcast flag since we can receive unicast traffic
1695 before being fully configured! */
1696 dhcp->msg_out->flags = 0;
1697 ip_addr_set_zero(&dhcp->msg_out->ciaddr);
1698 /* set ciaddr to netif->ip_addr based on message_type and state */
1699 if ((message_type == DHCP_INFORM) || (message_type == DHCP_DECLINE) ||
1700 ((message_type == DHCP_REQUEST) && /* DHCP_BOUND not used for sending! */
1701 ((dhcp->state==DHCP_RENEWING) || dhcp->state==DHCP_REBINDING))) {
1702 ip_addr_copy(dhcp->msg_out->ciaddr, netif->ip_addr);
1703 }
1704 ip_addr_set_zero(&dhcp->msg_out->yiaddr);
1705 ip_addr_set_zero(&dhcp->msg_out->siaddr);
1706 ip_addr_set_zero(&dhcp->msg_out->giaddr);
1707 for (i = 0; i < DHCP_CHADDR_LEN; i++) {
1708 /* copy netif hardware address, pad with zeroes */
1709 dhcp->msg_out->chaddr[i] = (i < netif->hwaddr_len) ? netif->hwaddr[i] : 0/* pad byte*/;
1710 }
1711 for (i = 0; i < DHCP_SNAME_LEN; i++) {
1712 dhcp->msg_out->sname[i] = 0;
1713 }
1714 for (i = 0; i < DHCP_FILE_LEN; i++) {
1715 dhcp->msg_out->file[i] = 0;
1716 }
1717 dhcp->msg_out->cookie = PP_HTONL(DHCP_MAGIC_COOKIE);
1718 dhcp->options_out_len = 0;
1719 /* fill options field with an incrementing array (for debugging purposes) */
1720 for (i = 0; i < DHCP_OPTIONS_LEN; i++) {
1721 dhcp->msg_out->options[i] = (u8_t)i; /* for debugging only, no matter if truncated */
1722 }
1723 /* Add option MESSAGE_TYPE */
1724 dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
1725 dhcp_option_byte(dhcp, message_type);
1726 return ERR_OK;
1727}
1728
1729/**
1730 * Free previously allocated memory used to send a DHCP request.
1731 *
1732 * @param dhcp the dhcp struct to free the request from
1733 */
1734static void
1735dhcp_delete_msg(struct dhcp *dhcp)
1736{
1737 LWIP_ERROR("dhcp_delete_msg: dhcp != NULL", (dhcp != NULL), return;);
1738 LWIP_ASSERT("dhcp_delete_msg: dhcp->p_out != NULL", dhcp->p_out != NULL);
1739 LWIP_ASSERT("dhcp_delete_msg: dhcp->msg_out != NULL", dhcp->msg_out != NULL);
1740 if (dhcp->p_out != NULL) {
1741 pbuf_free(dhcp->p_out);
1742 }
1743 dhcp->p_out = NULL;
1744 dhcp->msg_out = NULL;
1745}
1746
1747/**
1748 * Add a DHCP message trailer
1749 *
1750 * Adds the END option to the DHCP message, and if
1751 * necessary, up to three padding bytes.
1752 *
1753 * @param dhcp DHCP state structure
1754 */
1755static void
1756dhcp_option_trailer(struct dhcp *dhcp)
1757{
1758 LWIP_ERROR("dhcp_option_trailer: dhcp != NULL", (dhcp != NULL), return;);
1759 LWIP_ASSERT("dhcp_option_trailer: dhcp->msg_out != NULL\n", dhcp->msg_out != NULL);
1760 LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN);
1761 dhcp->msg_out->options[dhcp->options_out_len++] = DHCP_OPTION_END;
1762 /* packet is too small, or not 4 byte aligned? */
1763 while (((dhcp->options_out_len < DHCP_MIN_OPTIONS_LEN) || (dhcp->options_out_len & 3)) &&
1764 (dhcp->options_out_len < DHCP_OPTIONS_LEN)) {
1765 /* add a fill/padding byte */
1766 dhcp->msg_out->options[dhcp->options_out_len++] = 0;
1767 }
1768}
1769
1770#endif /* LWIP_DHCP */
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