3 * Dynamic Host Configuration Protocol client
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.
13 * Redistribution and use in source and binary forms, with or without modification,
14 * are permitted provided that the following conditions are met:
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.
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
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
40 * Author: Leon Woestenberg <leon.woestenberg@gmx.net>
42 * This is a DHCP client for the lwIP TCP/IP stack. It aims to conform
43 * with RFC 2131 and RFC 2132.
46 * - Support for interfaces other than Ethernet (SLIP, PPP, ...)
48 * Please coordinate changes and requests with Leon Woestenberg
49 * <leon.woestenberg@gmx.net>
51 * Integration with your code:
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)
57 * Then have your application call dhcp_coarse_tmr() and
58 * dhcp_fine_tmr() on the defined intervals.
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.
64 * Use dhcp_release(netif) to end the lease and use dhcp_stop(netif)
65 * to remove the DHCP client.
71 #if LWIP_DHCP /* don't build if not configured for use in lwipopts.h */
73 #include "lwip/stats.h"
76 #include "lwip/ip_addr.h"
77 #include "lwip/netif.h"
80 #include "lwip/dhcp.h"
81 #include "lwip/autoip.h"
83 #include "netif/etharp.h"
87 /** Default for DHCP_GLOBAL_XID is 0xABCD0000
88 * This can be changed by defining DHCP_GLOBAL_XID and DHCP_GLOBAL_XID_HEADER, e.g.
89 * #define DHCP_GLOBAL_XID_HEADER "stdlib.h"
90 * #define DHCP_GLOBAL_XID rand()
92 #ifdef DHCP_GLOBAL_XID_HEADER
93 #include DHCP_GLOBAL_XID_HEADER /* include optional starting XID generation prototypes */
96 /** DHCP_OPTION_MAX_MSG_SIZE is set to the MTU
97 * MTU is checked to be big enough in dhcp_start */
98 #define DHCP_MAX_MSG_LEN(netif) (netif->mtu)
99 #define DHCP_MAX_MSG_LEN_MIN_REQUIRED 576
100 /** Minimum length for reply before packet is parsed */
101 #define DHCP_MIN_REPLY_LEN 44
103 #define REBOOT_TRIES 2
105 /** Option handling: options are parsed in dhcp_parse_reply
106 * and saved in an array where other functions can load them from.
107 * This might be moved into the struct dhcp (not necessarily since
108 * lwIP is single-threaded and the array is only used while in recv
110 #define DHCP_OPTION_IDX_OVERLOAD 0
111 #define DHCP_OPTION_IDX_MSG_TYPE 1
112 #define DHCP_OPTION_IDX_SERVER_ID 2
113 #define DHCP_OPTION_IDX_LEASE_TIME 3
114 #define DHCP_OPTION_IDX_T1 4
115 #define DHCP_OPTION_IDX_T2 5
116 #define DHCP_OPTION_IDX_SUBNET_MASK 6
117 #define DHCP_OPTION_IDX_ROUTER 7
118 #define DHCP_OPTION_IDX_DNS_SERVER 8
119 #define DHCP_OPTION_IDX_MAX (DHCP_OPTION_IDX_DNS_SERVER + DNS_MAX_SERVERS)
121 /** Holds the decoded option values, only valid while in dhcp_recv.
122 @todo: move this into struct dhcp? */
123 u32_t dhcp_rx_options_val[DHCP_OPTION_IDX_MAX];
124 /** Holds a flag which option was received and is contained in dhcp_rx_options_val,
125 only valid while in dhcp_recv.
126 @todo: move this into struct dhcp? */
127 u8_t dhcp_rx_options_given[DHCP_OPTION_IDX_MAX];
129 #define dhcp_option_given(dhcp, idx) (dhcp_rx_options_given[idx] != 0)
130 #define dhcp_got_option(dhcp, idx) (dhcp_rx_options_given[idx] = 1)
131 #define dhcp_clear_option(dhcp, idx) (dhcp_rx_options_given[idx] = 0)
132 #define dhcp_clear_all_options(dhcp) (memset(dhcp_rx_options_given, 0, sizeof(dhcp_rx_options_given)))
133 #define dhcp_get_option_value(dhcp, idx) (dhcp_rx_options_val[idx])
134 #define dhcp_set_option_value(dhcp, idx, val) (dhcp_rx_options_val[idx] = (val))
137 /* DHCP client state machine functions */
138 static err_t dhcp_discover(struct netif *netif);
139 static err_t dhcp_select(struct netif *netif);
140 static void dhcp_bind(struct netif *netif);
141 #if DHCP_DOES_ARP_CHECK
142 static err_t dhcp_decline(struct netif *netif);
143 #endif /* DHCP_DOES_ARP_CHECK */
144 static err_t dhcp_rebind(struct netif *netif);
145 static err_t dhcp_reboot(struct netif *netif);
146 static void dhcp_set_state(struct dhcp *dhcp, u8_t new_state);
148 /* receive, unfold, parse and free incoming messages */
149 static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port);
151 /* set the DHCP timers */
152 static void dhcp_timeout(struct netif *netif);
153 static void dhcp_t1_timeout(struct netif *netif);
154 static void dhcp_t2_timeout(struct netif *netif);
156 /* build outgoing messages */
157 /* create a DHCP message, fill in common headers */
158 static err_t dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type);
159 /* free a DHCP request */
160 static void dhcp_delete_msg(struct dhcp *dhcp);
161 /* add a DHCP option (type, then length in bytes) */
162 static void dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len);
163 /* add option values */
164 static void dhcp_option_byte(struct dhcp *dhcp, u8_t value);
165 static void dhcp_option_short(struct dhcp *dhcp, u16_t value);
166 static void dhcp_option_long(struct dhcp *dhcp, u32_t value);
167 /* always add the DHCP options trailer to end and pad */
168 static void dhcp_option_trailer(struct dhcp *dhcp);
171 * Back-off the DHCP client (because of a received NAK response).
173 * Back-off the DHCP client because of a received NAK. Receiving a
174 * NAK means the client asked for something non-sensible, for
175 * example when it tries to renew a lease obtained on another network.
177 * We clear any existing set IP address and restart DHCP negotiation
178 * afresh (as per RFC2131 3.2.3).
180 * @param netif the netif under DHCP control
183 dhcp_handle_nak(struct netif *netif)
185 struct dhcp *dhcp = netif->dhcp;
186 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_nak(netif=%p) %c%c%"U16_F"\n",
187 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num));
188 /* Set the interface down since the address must no longer be used, as per RFC2131 */
189 netif_set_down(netif);
190 /* remove IP address from interface */
191 netif_set_ipaddr(netif, IP_ADDR_ANY);
192 netif_set_gw(netif, IP_ADDR_ANY);
193 netif_set_netmask(netif, IP_ADDR_ANY);
194 /* Change to a defined state */
195 dhcp_set_state(dhcp, DHCP_BACKING_OFF);
196 /* We can immediately restart discovery */
197 dhcp_discover(netif);
200 #if DHCP_DOES_ARP_CHECK
202 * Checks if the offered IP address is already in use.
204 * It does so by sending an ARP request for the offered address and
205 * entering CHECKING state. If no ARP reply is received within a small
206 * interval, the address is assumed to be free for use by us.
208 * @param netif the netif under DHCP control
211 dhcp_check(struct netif *netif)
213 struct dhcp *dhcp = netif->dhcp;
216 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_check(netif=%p) %c%c\n", (void *)netif, (s16_t)netif->name[0],
217 (s16_t)netif->name[1]));
218 dhcp_set_state(dhcp, DHCP_CHECKING);
219 /* create an ARP query for the offered IP address, expecting that no host
220 responds, as the IP address should not be in use. */
221 result = etharp_query(netif, &dhcp->offered_ip_addr, NULL);
222 if (result != ERR_OK) {
223 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_check: could not perform ARP query\n"));
227 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
228 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_check(): set request timeout %"U16_F" msecs\n", msecs));
230 #endif /* DHCP_DOES_ARP_CHECK */
233 * Remember the configuration offered by a DHCP server.
235 * @param netif the netif under DHCP control
238 dhcp_handle_offer(struct netif *netif)
240 struct dhcp *dhcp = netif->dhcp;
241 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_offer(netif=%p) %c%c%"U16_F"\n",
242 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num));
243 /* obtain the server address */
244 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SERVER_ID)) {
245 ip4_addr_set_u32(&dhcp->server_ip_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SERVER_ID)));
246 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): server 0x%08"X32_F"\n",
247 ip4_addr_get_u32(&dhcp->server_ip_addr)));
248 /* remember offered address */
249 ip_addr_copy(dhcp->offered_ip_addr, dhcp->msg_in->yiaddr);
250 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): offer for 0x%08"X32_F"\n",
251 ip4_addr_get_u32(&dhcp->offered_ip_addr)));
255 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
256 ("dhcp_handle_offer(netif=%p) did not get server ID!\n", (void*)netif));
261 * Select a DHCP server offer out of all offers.
263 * Simply select the first offer received.
265 * @param netif the netif under DHCP control
266 * @return lwIP specific error (see error.h)
269 dhcp_select(struct netif *netif)
271 struct dhcp *dhcp = netif->dhcp;
275 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));
276 dhcp_set_state(dhcp, DHCP_REQUESTING);
278 /* create and initialize the DHCP message header */
279 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST);
280 if (result == ERR_OK) {
281 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
282 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif));
284 /* MUST request the offered IP address */
285 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
286 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
288 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4);
289 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->server_ip_addr)));
291 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/);
292 dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK);
293 dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER);
294 dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST);
295 dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER);
297 #if LWIP_NETIF_HOSTNAME
298 if (netif->hostname != NULL) {
299 const char *p = (const char*)netif->hostname;
300 u8_t namelen = (u8_t)strlen(p);
302 LWIP_ASSERT("DHCP: hostname is too long!", namelen < 255);
303 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, namelen);
305 dhcp_option_byte(dhcp, *p++);
309 #endif /* LWIP_NETIF_HOSTNAME */
311 dhcp_option_trailer(dhcp);
312 /* shrink the pbuf to the actual content length */
313 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
315 /* send broadcast to any DHCP server */
316 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
317 dhcp_delete_msg(dhcp);
318 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_select: REQUESTING\n"));
320 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_select: could not allocate DHCP request\n"));
323 msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000;
324 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
325 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_select(): set request timeout %"U16_F" msecs\n", msecs));
330 * The DHCP timer that checks for lease renewal/rebind timeouts.
335 struct netif *netif = netif_list;
336 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n"));
337 /* iterate through all network interfaces */
338 while (netif != NULL) {
339 /* only act on DHCP configured interfaces */
340 if (netif->dhcp != NULL) {
341 /* timer is active (non zero), and triggers (zeroes) now? */
342 if (netif->dhcp->t2_timeout-- == 1) {
343 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t2 timeout\n"));
344 /* this clients' rebind timeout triggered */
345 dhcp_t2_timeout(netif);
346 /* timer is active (non zero), and triggers (zeroes) now */
347 } else if (netif->dhcp->t1_timeout-- == 1) {
348 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t1 timeout\n"));
349 /* this clients' renewal timeout triggered */
350 dhcp_t1_timeout(netif);
353 /* proceed to next netif */
359 * DHCP transaction timeout handling
361 * A DHCP server is expected to respond within a short period of time.
362 * This timer checks whether an outstanding DHCP request is timed out.
367 struct netif *netif = netif_list;
368 /* loop through netif's */
369 while (netif != NULL) {
370 /* only act on DHCP configured interfaces */
371 if (netif->dhcp != NULL) {
372 /* timer is active (non zero), and is about to trigger now */
373 if (netif->dhcp->request_timeout > 1) {
374 netif->dhcp->request_timeout--;
376 else if (netif->dhcp->request_timeout == 1) {
377 netif->dhcp->request_timeout--;
378 /* { netif->dhcp->request_timeout == 0 } */
379 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_fine_tmr(): request timeout\n"));
380 /* this client's request timeout triggered */
384 /* proceed to next network interface */
390 * A DHCP negotiation transaction, or ARP request, has timed out.
392 * The timer that was started with the DHCP or ARP request has
393 * timed out, indicating no response was received in time.
395 * @param netif the netif under DHCP control
398 dhcp_timeout(struct netif *netif)
400 struct dhcp *dhcp = netif->dhcp;
401 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout()\n"));
402 /* back-off period has passed, or server selection timed out */
403 if ((dhcp->state == DHCP_BACKING_OFF) || (dhcp->state == DHCP_SELECTING)) {
404 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout(): restarting discovery\n"));
405 dhcp_discover(netif);
406 /* receiving the requested lease timed out */
407 } else if (dhcp->state == DHCP_REQUESTING) {
408 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, DHCP request timed out\n"));
409 if (dhcp->tries <= 5) {
412 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, releasing, restarting\n"));
414 dhcp_discover(netif);
416 #if DHCP_DOES_ARP_CHECK
417 /* received no ARP reply for the offered address (which is good) */
418 } else if (dhcp->state == DHCP_CHECKING) {
419 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): CHECKING, ARP request timed out\n"));
420 if (dhcp->tries <= 1) {
422 /* no ARP replies on the offered address,
423 looks like the IP address is indeed free */
425 /* bind the interface to the offered address */
428 #endif /* DHCP_DOES_ARP_CHECK */
430 /* did not get response to renew request? */
431 else if (dhcp->state == DHCP_RENEWING) {
432 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): RENEWING, DHCP request timed out\n"));
433 /* just retry renewal */
434 /* note that the rebind timer will eventually time-out if renew does not work */
436 /* did not get response to rebind request? */
437 } else if (dhcp->state == DHCP_REBINDING) {
438 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REBINDING, DHCP request timed out\n"));
439 if (dhcp->tries <= 8) {
442 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): RELEASING, DISCOVERING\n"));
444 dhcp_discover(netif);
446 } else if (dhcp->state == DHCP_REBOOTING) {
447 if (dhcp->tries < REBOOT_TRIES) {
450 dhcp_discover(netif);
456 * The renewal period has timed out.
458 * @param netif the netif under DHCP control
461 dhcp_t1_timeout(struct netif *netif)
463 struct dhcp *dhcp = netif->dhcp;
464 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_t1_timeout()\n"));
465 if ((dhcp->state == DHCP_REQUESTING) || (dhcp->state == DHCP_BOUND) ||
466 (dhcp->state == DHCP_RENEWING)) {
467 /* just retry to renew - note that the rebind timer (t2) will
468 * eventually time-out if renew tries fail. */
469 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
470 ("dhcp_t1_timeout(): must renew\n"));
471 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state
472 DHCP_RENEWING, not DHCP_BOUND */
478 * The rebind period has timed out.
480 * @param netif the netif under DHCP control
483 dhcp_t2_timeout(struct netif *netif)
485 struct dhcp *dhcp = netif->dhcp;
486 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t2_timeout()\n"));
487 if ((dhcp->state == DHCP_REQUESTING) || (dhcp->state == DHCP_BOUND) ||
488 (dhcp->state == DHCP_RENEWING)) {
489 /* just retry to rebind */
490 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
491 ("dhcp_t2_timeout(): must rebind\n"));
492 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state
493 DHCP_REBINDING, not DHCP_BOUND */
499 * Handle a DHCP ACK packet
501 * @param netif the netif under DHCP control
504 dhcp_handle_ack(struct netif *netif)
506 struct dhcp *dhcp = netif->dhcp;
509 #endif /* LWIP_DNS */
511 /* clear options we might not get from the ACK */
512 ip_addr_set_zero(&dhcp->offered_sn_mask);
513 ip_addr_set_zero(&dhcp->offered_gw_addr);
514 #if LWIP_DHCP_BOOTP_FILE
515 ip_addr_set_zero(&dhcp->offered_si_addr);
516 #endif /* LWIP_DHCP_BOOTP_FILE */
518 /* lease time given? */
519 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_LEASE_TIME)) {
520 /* remember offered lease time */
521 dhcp->offered_t0_lease = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_LEASE_TIME);
523 /* renewal period given? */
524 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T1)) {
525 /* remember given renewal period */
526 dhcp->offered_t1_renew = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T1);
528 /* calculate safe periods for renewal */
529 dhcp->offered_t1_renew = dhcp->offered_t0_lease / 2;
532 /* renewal period given? */
533 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T2)) {
534 /* remember given rebind period */
535 dhcp->offered_t2_rebind = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T2);
537 /* calculate safe periods for rebinding */
538 dhcp->offered_t2_rebind = dhcp->offered_t0_lease;
541 /* (y)our internet address */
542 ip_addr_copy(dhcp->offered_ip_addr, dhcp->msg_in->yiaddr);
544 #if LWIP_DHCP_BOOTP_FILE
545 /* copy boot server address,
546 boot file name copied in dhcp_parse_reply if not overloaded */
547 ip_addr_copy(dhcp->offered_si_addr, dhcp->msg_in->siaddr);
548 #endif /* LWIP_DHCP_BOOTP_FILE */
550 /* subnet mask given? */
551 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)) {
552 /* remember given subnet mask */
553 ip4_addr_set_u32(&dhcp->offered_sn_mask, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)));
554 dhcp->subnet_mask_given = 1;
556 dhcp->subnet_mask_given = 0;
560 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_ROUTER)) {
561 ip4_addr_set_u32(&dhcp->offered_gw_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_ROUTER)));
567 while(dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n) && (n < DNS_MAX_SERVERS)) {
569 ip4_addr_set_u32(&dns_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n)));
570 dns_setserver(n, &dns_addr);
573 #endif /* LWIP_DNS */
576 /** Set a statically allocated struct dhcp to work with.
577 * Using this prevents dhcp_start to allocate it using mem_malloc.
579 * @param netif the netif for which to set the struct dhcp
580 * @param dhcp (uninitialised) dhcp struct allocated by the application
583 dhcp_set_struct(struct netif *netif, struct dhcp *dhcp)
585 LWIP_ASSERT("netif != NULL", netif != NULL);
586 LWIP_ASSERT("dhcp != NULL", dhcp != NULL);
587 LWIP_ASSERT("netif already has a struct dhcp set", netif->dhcp == NULL);
589 /* clear data structure */
590 memset(dhcp, 0, sizeof(struct dhcp));
591 /* dhcp_set_state(&dhcp, DHCP_OFF); */
596 * Start DHCP negotiation for a network interface.
598 * If no DHCP client instance was attached to this interface,
599 * a new client is created first. If a DHCP client instance
600 * was already present, it restarts negotiation.
602 * @param netif The lwIP network interface
603 * @return lwIP error code
604 * - ERR_OK - No error
605 * - ERR_MEM - Out of memory
608 dhcp_start(struct netif *netif)
611 err_t result = ERR_OK;
613 LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;);
615 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));
616 /* Remove the flag that says this netif is handled by DHCP,
617 it is set when we succeeded starting. */
618 netif->flags &= ~NETIF_FLAG_DHCP;
620 /* check hwtype of the netif */
621 if ((netif->flags & NETIF_FLAG_ETHARP) == 0) {
622 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): No ETHARP netif\n"));
626 /* check MTU of the netif */
627 if (netif->mtu < DHCP_MAX_MSG_LEN_MIN_REQUIRED) {
628 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): Cannot use this netif with DHCP: MTU is too small\n"));
632 /* no DHCP client attached yet? */
634 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting new DHCP client\n"));
635 dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp));
637 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n"));
640 /* store this dhcp client in the netif */
642 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): allocated dhcp"));
643 /* already has DHCP client attached */
645 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(): restarting DHCP configuration\n"));
646 if (dhcp->pcb != NULL) {
647 udp_remove(dhcp->pcb);
649 LWIP_ASSERT("pbuf p_out wasn't freed", dhcp->p_out == NULL);
650 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL );
653 /* clear data structure */
654 memset(dhcp, 0, sizeof(struct dhcp));
655 /* dhcp_set_state(&dhcp, DHCP_OFF); */
656 /* allocate UDP PCB */
657 dhcp->pcb = udp_new();
658 if (dhcp->pcb == NULL) {
659 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not obtain pcb\n"));
662 dhcp->pcb->so_options |= SOF_BROADCAST;
663 /* set up local and remote port for the pcb */
664 udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT);
665 udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT);
666 /* set up the recv callback and argument */
667 udp_recv(dhcp->pcb, dhcp_recv, netif);
668 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n"));
669 /* (re)start the DHCP negotiation */
670 result = dhcp_discover(netif);
671 if (result != ERR_OK) {
672 /* free resources allocated above */
676 /* Set the flag that says this netif is handled by DHCP. */
677 netif->flags |= NETIF_FLAG_DHCP;
682 * Inform a DHCP server of our manual configuration.
684 * This informs DHCP servers of our fixed IP address configuration
685 * by sending an INFORM message. It does not involve DHCP address
686 * configuration, it is just here to be nice to the network.
688 * @param netif The lwIP network interface
691 dhcp_inform(struct netif *netif)
694 err_t result = ERR_OK;
697 LWIP_ERROR("netif != NULL", (netif != NULL), return;);
699 memset(&dhcp, 0, sizeof(struct dhcp));
700 dhcp_set_state(&dhcp, DHCP_INFORM);
702 if ((netif->dhcp != NULL) && (netif->dhcp->pcb != NULL)) {
703 /* re-use existing pcb */
704 pcb = netif->dhcp->pcb;
708 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform(): could not obtain pcb"));
712 dhcp.pcb->so_options |= SOF_BROADCAST;
713 udp_bind(dhcp.pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT);
714 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_inform(): created new udp pcb\n"));
716 /* create and initialize the DHCP message header */
717 result = dhcp_create_msg(netif, &dhcp, DHCP_INFORM);
718 if (result == ERR_OK) {
719 dhcp_option(&dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
720 dhcp_option_short(&dhcp, DHCP_MAX_MSG_LEN(netif));
722 dhcp_option_trailer(&dhcp);
724 pbuf_realloc(dhcp.p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp.options_out_len);
726 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n"));
727 udp_sendto_if(pcb, dhcp.p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
728 dhcp_delete_msg(&dhcp);
730 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform: could not allocate DHCP request\n"));
733 if (dhcp.pcb != NULL) {
734 /* otherwise, the existing pcb was used */
735 udp_remove(dhcp.pcb);
739 /** Handle a possible change in the network configuration.
741 * This enters the REBOOTING state to verify that the currently bound
742 * address is still valid.
745 dhcp_network_changed(struct netif *netif)
747 struct dhcp *dhcp = netif->dhcp;
750 switch (dhcp->state) {
755 netif_set_down(netif);
764 dhcp_discover(netif);
769 #if DHCP_DOES_ARP_CHECK
771 * Match an ARP reply with the offered IP address.
773 * @param netif the network interface on which the reply was received
774 * @param addr The IP address we received a reply from
776 void dhcp_arp_reply(struct netif *netif, ip_addr_t *addr)
778 LWIP_ERROR("netif != NULL", (netif != NULL), return;);
779 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_arp_reply()\n"));
780 /* is a DHCP client doing an ARP check? */
781 if ((netif->dhcp != NULL) && (netif->dhcp->state == DHCP_CHECKING)) {
782 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_arp_reply(): CHECKING, arp reply for 0x%08"X32_F"\n",
783 ip4_addr_get_u32(addr)));
784 /* did a host respond with the address we
785 were offered by the DHCP server? */
786 if (ip_addr_cmp(addr, &netif->dhcp->offered_ip_addr)) {
787 /* we will not accept the offered address */
788 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
789 ("dhcp_arp_reply(): arp reply matched with offered address, declining\n"));
796 * Decline an offered lease.
798 * Tell the DHCP server we do not accept the offered address.
799 * One reason to decline the lease is when we find out the address
800 * is already in use by another host (through ARP).
802 * @param netif the netif under DHCP control
805 dhcp_decline(struct netif *netif)
807 struct dhcp *dhcp = netif->dhcp;
808 err_t result = ERR_OK;
810 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline()\n"));
811 dhcp_set_state(dhcp, DHCP_BACKING_OFF);
812 /* create and initialize the DHCP message header */
813 result = dhcp_create_msg(netif, dhcp, DHCP_DECLINE);
814 if (result == ERR_OK) {
815 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
816 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
818 dhcp_option_trailer(dhcp);
819 /* resize pbuf to reflect true size of options */
820 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
822 /* per section 4.4.4, broadcast DECLINE messages */
823 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
824 dhcp_delete_msg(dhcp);
825 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_decline: BACKING OFF\n"));
827 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
828 ("dhcp_decline: could not allocate DHCP request\n"));
832 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
833 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs));
836 #endif /* DHCP_DOES_ARP_CHECK */
840 * Start the DHCP process, discover a DHCP server.
842 * @param netif the netif under DHCP control
845 dhcp_discover(struct netif *netif)
847 struct dhcp *dhcp = netif->dhcp;
848 err_t result = ERR_OK;
850 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover()\n"));
851 ip_addr_set_any(&dhcp->offered_ip_addr);
852 dhcp_set_state(dhcp, DHCP_SELECTING);
853 /* create and initialize the DHCP message header */
854 result = dhcp_create_msg(netif, dhcp, DHCP_DISCOVER);
855 if (result == ERR_OK) {
856 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n"));
858 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
859 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif));
861 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/);
862 dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK);
863 dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER);
864 dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST);
865 dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER);
867 dhcp_option_trailer(dhcp);
869 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: realloc()ing\n"));
870 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
872 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, DHCP_SERVER_PORT)\n"));
873 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
874 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()ing\n"));
875 dhcp_delete_msg(dhcp);
876 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover: SELECTING\n"));
878 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_discover: could not allocate DHCP request\n"));
881 #if LWIP_DHCP_AUTOIP_COOP
882 if(dhcp->tries >= LWIP_DHCP_AUTOIP_COOP_TRIES && dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_OFF) {
883 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_ON;
886 #endif /* LWIP_DHCP_AUTOIP_COOP */
887 msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000;
888 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
889 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs));
895 * Bind the interface to the offered IP address.
897 * @param netif network interface to bind to the offered address
900 dhcp_bind(struct netif *netif)
904 ip_addr_t sn_mask, gw_addr;
905 LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;);
907 LWIP_ERROR("dhcp_bind: dhcp != NULL", (dhcp != NULL), return;);
908 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));
910 /* temporary DHCP lease? */
911 if (dhcp->offered_t1_renew != 0xffffffffUL) {
912 /* set renewal period timer */
913 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew));
914 timeout = (dhcp->offered_t1_renew + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS;
915 if(timeout > 0xffff) {
918 dhcp->t1_timeout = (u16_t)timeout;
919 if (dhcp->t1_timeout == 0) {
920 dhcp->t1_timeout = 1;
922 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew*1000));
924 /* set renewal period timer */
925 if (dhcp->offered_t2_rebind != 0xffffffffUL) {
926 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind));
927 timeout = (dhcp->offered_t2_rebind + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS;
928 if(timeout > 0xffff) {
931 dhcp->t2_timeout = (u16_t)timeout;
932 if (dhcp->t2_timeout == 0) {
933 dhcp->t2_timeout = 1;
935 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t2_rebind*1000));
938 if (dhcp->subnet_mask_given) {
939 /* copy offered network mask */
940 ip_addr_copy(sn_mask, dhcp->offered_sn_mask);
942 /* subnet mask not given, choose a safe subnet mask given the network class */
943 u8_t first_octet = ip4_addr1(&dhcp->offered_ip_addr);
944 if (first_octet <= 127) {
945 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xff000000));
946 } else if (first_octet >= 192) {
947 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffffff00));
949 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffff0000));
953 ip_addr_copy(gw_addr, dhcp->offered_gw_addr);
954 /* gateway address not given? */
955 if (ip_addr_isany(&gw_addr)) {
956 /* copy network address */
957 ip_addr_get_network(&gw_addr, &dhcp->offered_ip_addr, &sn_mask);
958 /* use first host address on network as gateway */
959 ip4_addr_set_u32(&gw_addr, ip4_addr_get_u32(&gw_addr) | PP_HTONL(0x00000001));
962 #if LWIP_DHCP_AUTOIP_COOP
963 if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
965 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
967 #endif /* LWIP_DHCP_AUTOIP_COOP */
969 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): IP: 0x%08"X32_F"\n",
970 ip4_addr_get_u32(&dhcp->offered_ip_addr)));
971 netif_set_ipaddr(netif, &dhcp->offered_ip_addr);
972 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): SN: 0x%08"X32_F"\n",
973 ip4_addr_get_u32(&sn_mask)));
974 netif_set_netmask(netif, &sn_mask);
975 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): GW: 0x%08"X32_F"\n",
976 ip4_addr_get_u32(&gw_addr)));
977 netif_set_gw(netif, &gw_addr);
978 /* bring the interface up */
980 /* netif is now bound to DHCP leased address */
981 dhcp_set_state(dhcp, DHCP_BOUND);
985 * Renew an existing DHCP lease at the involved DHCP server.
987 * @param netif network interface which must renew its lease
990 dhcp_renew(struct netif *netif)
992 struct dhcp *dhcp = netif->dhcp;
995 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_renew()\n"));
996 dhcp_set_state(dhcp, DHCP_RENEWING);
998 /* create and initialize the DHCP message header */
999 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST);
1000 if (result == ERR_OK) {
1001 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1002 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif));
1004 #if LWIP_NETIF_HOSTNAME
1005 if (netif->hostname != NULL) {
1006 const char *p = (const char*)netif->hostname;
1007 u8_t namelen = (u8_t)strlen(p);
1009 LWIP_ASSERT("DHCP: hostname is too long!", namelen < 255);
1010 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, namelen);
1012 dhcp_option_byte(dhcp, *p++);
1016 #endif /* LWIP_NETIF_HOSTNAME */
1019 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
1020 dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr));
1024 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4);
1025 dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr));
1027 /* append DHCP message trailer */
1028 dhcp_option_trailer(dhcp);
1030 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
1032 udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif);
1033 dhcp_delete_msg(dhcp);
1035 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew: RENEWING\n"));
1037 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_renew: could not allocate DHCP request\n"));
1040 /* back-off on retries, but to a maximum of 20 seconds */
1041 msecs = dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000;
1042 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
1043 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs));
1048 * Rebind with a DHCP server for an existing DHCP lease.
1050 * @param netif network interface which must rebind with a DHCP server
1053 dhcp_rebind(struct netif *netif)
1055 struct dhcp *dhcp = netif->dhcp;
1058 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n"));
1059 dhcp_set_state(dhcp, DHCP_REBINDING);
1061 /* create and initialize the DHCP message header */
1062 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST);
1063 if (result == ERR_OK) {
1064 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1065 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif));
1067 #if LWIP_NETIF_HOSTNAME
1068 if (netif->hostname != NULL) {
1069 const char *p = (const char*)netif->hostname;
1070 u8_t namelen = (u8_t)strlen(p);
1072 LWIP_ASSERT("DHCP: hostname is too long!", namelen < 255);
1073 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, namelen);
1075 dhcp_option_byte(dhcp, *p++);
1079 #endif /* LWIP_NETIF_HOSTNAME */
1082 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
1083 dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr));
1085 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4);
1086 dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr));
1089 dhcp_option_trailer(dhcp);
1091 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
1093 /* broadcast to server */
1094 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
1095 dhcp_delete_msg(dhcp);
1096 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n"));
1098 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_rebind: could not allocate DHCP request\n"));
1101 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000;
1102 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
1103 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs));
1108 * Enter REBOOTING state to verify an existing lease
1110 * @param netif network interface which must reboot
1113 dhcp_reboot(struct netif *netif)
1115 struct dhcp *dhcp = netif->dhcp;
1118 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n"));
1119 dhcp_set_state(dhcp, DHCP_REBOOTING);
1121 /* create and initialize the DHCP message header */
1122 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST);
1123 if (result == ERR_OK) {
1124 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1125 dhcp_option_short(dhcp, 576);
1127 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
1128 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
1130 dhcp_option_trailer(dhcp);
1132 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
1134 /* broadcast to server */
1135 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
1136 dhcp_delete_msg(dhcp);
1137 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot: REBOOTING\n"));
1139 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_reboot: could not allocate DHCP request\n"));
1142 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000;
1143 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
1144 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot(): set request timeout %"U16_F" msecs\n", msecs));
1150 * Release a DHCP lease.
1152 * @param netif network interface which must release its lease
1155 dhcp_release(struct netif *netif)
1157 struct dhcp *dhcp = netif->dhcp;
1160 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release()\n"));
1162 /* idle DHCP client */
1163 dhcp_set_state(dhcp, DHCP_OFF);
1164 /* clean old DHCP offer */
1165 ip_addr_set_zero(&dhcp->server_ip_addr);
1166 ip_addr_set_zero(&dhcp->offered_ip_addr);
1167 ip_addr_set_zero(&dhcp->offered_sn_mask);
1168 ip_addr_set_zero(&dhcp->offered_gw_addr);
1169 #if LWIP_DHCP_BOOTP_FILE
1170 ip_addr_set_zero(&dhcp->offered_si_addr);
1171 #endif /* LWIP_DHCP_BOOTP_FILE */
1172 dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0;
1174 /* create and initialize the DHCP message header */
1175 result = dhcp_create_msg(netif, dhcp, DHCP_RELEASE);
1176 if (result == ERR_OK) {
1177 dhcp_option_trailer(dhcp);
1179 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
1181 udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif);
1182 dhcp_delete_msg(dhcp);
1183 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_OFF\n"));
1185 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n"));
1188 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000;
1189 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
1190 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release(): set request timeout %"U16_F" msecs\n", msecs));
1191 /* bring the interface down */
1192 netif_set_down(netif);
1193 /* remove IP address from interface */
1194 netif_set_ipaddr(netif, IP_ADDR_ANY);
1195 netif_set_gw(netif, IP_ADDR_ANY);
1196 netif_set_netmask(netif, IP_ADDR_ANY);
1202 * Remove the DHCP client from the interface.
1204 * @param netif The network interface to stop DHCP on
1207 dhcp_stop(struct netif *netif)
1209 struct dhcp *dhcp = netif->dhcp;
1210 LWIP_ERROR("dhcp_stop: netif != NULL", (netif != NULL), return;);
1211 /* Remove the flag that says this netif is handled by DHCP. */
1212 netif->flags &= ~NETIF_FLAG_DHCP;
1214 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_stop()\n"));
1215 /* netif is DHCP configured? */
1217 #if LWIP_DHCP_AUTOIP_COOP
1218 if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
1220 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
1222 #endif /* LWIP_DHCP_AUTOIP_COOP */
1224 if (dhcp->pcb != NULL) {
1225 udp_remove(dhcp->pcb);
1228 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL);
1229 dhcp_set_state(dhcp, DHCP_OFF);
1234 * Set the DHCP state of a DHCP client.
1236 * If the state changed, reset the number of tries.
1239 dhcp_set_state(struct dhcp *dhcp, u8_t new_state)
1241 if (new_state != dhcp->state) {
1242 dhcp->state = new_state;
1244 dhcp->request_timeout = 0;
1249 * Concatenate an option type and length field to the outgoing
1254 dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len)
1256 LWIP_ASSERT("dhcp_option: dhcp->options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN);
1257 dhcp->msg_out->options[dhcp->options_out_len++] = option_type;
1258 dhcp->msg_out->options[dhcp->options_out_len++] = option_len;
1261 * Concatenate a single byte to the outgoing DHCP message.
1265 dhcp_option_byte(struct dhcp *dhcp, u8_t value)
1267 LWIP_ASSERT("dhcp_option_byte: dhcp->options_out_len < DHCP_OPTIONS_LEN", dhcp->options_out_len < DHCP_OPTIONS_LEN);
1268 dhcp->msg_out->options[dhcp->options_out_len++] = value;
1272 dhcp_option_short(struct dhcp *dhcp, u16_t value)
1274 LWIP_ASSERT("dhcp_option_short: dhcp->options_out_len + 2 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U <= DHCP_OPTIONS_LEN);
1275 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff00U) >> 8);
1276 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t) (value & 0x00ffU);
1280 dhcp_option_long(struct dhcp *dhcp, u32_t value)
1282 LWIP_ASSERT("dhcp_option_long: dhcp->options_out_len + 4 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 4U <= DHCP_OPTIONS_LEN);
1283 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24);
1284 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16);
1285 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8);
1286 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x000000ffUL));
1290 * Extract the DHCP message and the DHCP options.
1292 * Extract the DHCP message and the DHCP options, each into a contiguous
1293 * piece of memory. As a DHCP message is variable sized by its options,
1294 * and also allows overriding some fields for options, the easy approach
1295 * is to first unfold the options into a conitguous piece of memory, and
1296 * use that further on.
1300 dhcp_parse_reply(struct dhcp *dhcp, struct pbuf *p)
1306 u16_t options_idx_max;
1308 int parse_file_as_options = 0;
1309 int parse_sname_as_options = 0;
1311 /* clear received options */
1312 dhcp_clear_all_options(dhcp);
1313 /* check that beginning of dhcp_msg (up to and including chaddr) is in first pbuf */
1314 if (p->len < DHCP_SNAME_OFS) {
1317 dhcp->msg_in = (struct dhcp_msg *)p->payload;
1318 #if LWIP_DHCP_BOOTP_FILE
1319 /* clear boot file name */
1320 dhcp->boot_file_name[0] = 0;
1321 #endif /* LWIP_DHCP_BOOTP_FILE */
1325 /* start with options field */
1326 options_idx = DHCP_OPTIONS_OFS;
1327 /* parse options to the end of the received packet */
1328 options_idx_max = p->tot_len;
1331 while((q != NULL) && (options_idx >= q->len)) {
1332 options_idx -= q->len;
1333 options_idx_max -= q->len;
1339 offset = options_idx;
1340 offset_max = options_idx_max;
1341 options = (u8_t*)q->payload;
1342 /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */
1343 while((q != NULL) && (options[offset] != DHCP_OPTION_END) && (offset < offset_max)) {
1344 u8_t op = options[offset];
1346 u8_t decode_len = 0;
1347 int decode_idx = -1;
1348 u16_t val_offset = offset + 2;
1349 /* len byte might be in the next pbuf */
1350 if (offset + 1 < q->len) {
1351 len = options[offset + 1];
1353 len = (q->next != NULL ? ((u8_t*)q->next->payload)[0] : 0);
1355 /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F, msg_offset, q->len)); */
1358 /* case(DHCP_OPTION_END): handled above */
1359 case(DHCP_OPTION_PAD):
1360 /* special option: no len encoded */
1361 decode_len = len = 0;
1362 /* will be increased below */
1365 case(DHCP_OPTION_SUBNET_MASK):
1366 LWIP_ASSERT("len == 4", len == 4);
1367 decode_idx = DHCP_OPTION_IDX_SUBNET_MASK;
1369 case(DHCP_OPTION_ROUTER):
1370 decode_len = 4; /* only copy the first given router */
1371 LWIP_ASSERT("len >= decode_len", len >= decode_len);
1372 decode_idx = DHCP_OPTION_IDX_ROUTER;
1374 case(DHCP_OPTION_DNS_SERVER):
1375 /* special case: there might be more than one server */
1376 LWIP_ASSERT("len % 4 == 0", len % 4 == 0);
1377 /* limit number of DNS servers */
1378 decode_len = LWIP_MIN(len, 4 * DNS_MAX_SERVERS);
1379 LWIP_ASSERT("len >= decode_len", len >= decode_len);
1380 decode_idx = DHCP_OPTION_IDX_DNS_SERVER;
1382 case(DHCP_OPTION_LEASE_TIME):
1383 LWIP_ASSERT("len == 4", len == 4);
1384 decode_idx = DHCP_OPTION_IDX_LEASE_TIME;
1386 case(DHCP_OPTION_OVERLOAD):
1387 LWIP_ASSERT("len == 1", len == 1);
1388 decode_idx = DHCP_OPTION_IDX_OVERLOAD;
1390 case(DHCP_OPTION_MESSAGE_TYPE):
1391 LWIP_ASSERT("len == 1", len == 1);
1392 decode_idx = DHCP_OPTION_IDX_MSG_TYPE;
1394 case(DHCP_OPTION_SERVER_ID):
1395 LWIP_ASSERT("len == 4", len == 4);
1396 decode_idx = DHCP_OPTION_IDX_SERVER_ID;
1398 case(DHCP_OPTION_T1):
1399 LWIP_ASSERT("len == 4", len == 4);
1400 decode_idx = DHCP_OPTION_IDX_T1;
1402 case(DHCP_OPTION_T2):
1403 LWIP_ASSERT("len == 4", len == 4);
1404 decode_idx = DHCP_OPTION_IDX_T2;
1408 LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", op));
1412 if (decode_len > 0) {
1416 LWIP_ASSERT("check decode_idx", decode_idx >= 0 && decode_idx < DHCP_OPTION_IDX_MAX);
1417 LWIP_ASSERT("option already decoded", !dhcp_option_given(dhcp, decode_idx));
1418 copy_len = LWIP_MIN(decode_len, 4);
1419 pbuf_copy_partial(q, &value, copy_len, val_offset);
1420 if (decode_len > 4) {
1421 /* decode more than one u32_t */
1422 LWIP_ASSERT("decode_len % 4 == 0", decode_len % 4 == 0);
1423 dhcp_got_option(dhcp, decode_idx);
1424 dhcp_set_option_value(dhcp, decode_idx, htonl(value));
1429 } else if (decode_len == 4) {
1430 value = ntohl(value);
1432 LWIP_ASSERT("invalid decode_len", decode_len == 1);
1434 dhcp_got_option(dhcp, decode_idx);
1435 dhcp_set_option_value(dhcp, decode_idx, value);
1437 if (offset >= q->len) {
1439 offset_max -= q->len;
1441 options = (u8_t*)q->payload;
1444 /* is this an overloaded message? */
1445 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_OVERLOAD)) {
1446 u32_t overload = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_OVERLOAD);
1447 dhcp_clear_option(dhcp, DHCP_OPTION_IDX_OVERLOAD);
1448 if (overload == DHCP_OVERLOAD_FILE) {
1449 parse_file_as_options = 1;
1450 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded file field\n"));
1451 } else if (overload == DHCP_OVERLOAD_SNAME) {
1452 parse_sname_as_options = 1;
1453 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname field\n"));
1454 } else if (overload == DHCP_OVERLOAD_SNAME_FILE) {
1455 parse_sname_as_options = 1;
1456 parse_file_as_options = 1;
1457 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname and file field\n"));
1459 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("invalid overload option: %d\n", (int)overload));
1461 #if LWIP_DHCP_BOOTP_FILE
1462 if (!parse_file_as_options) {
1463 /* only do this for ACK messages */
1464 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) &&
1465 (dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK))
1466 /* copy bootp file name, don't care for sname (server hostname) */
1467 pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS);
1468 /* make sure the string is really NULL-terminated */
1469 dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0;
1471 #endif /* LWIP_DHCP_BOOTP_FILE */
1473 if (parse_file_as_options) {
1474 /* if both are overloaded, parse file first and then sname (RFC 2131 ch. 4.1) */
1475 parse_file_as_options = 0;
1476 options_idx = DHCP_FILE_OFS;
1477 options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN;
1479 } else if (parse_sname_as_options) {
1480 parse_sname_as_options = 0;
1481 options_idx = DHCP_SNAME_OFS;
1482 options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN;
1489 * If an incoming DHCP message is in response to us, then trigger the state machine
1492 dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port)
1494 struct netif *netif = (struct netif *)arg;
1495 struct dhcp *dhcp = netif->dhcp;
1496 struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload;
1499 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,
1500 ip4_addr1_16(addr), ip4_addr2_16(addr), ip4_addr3_16(addr), ip4_addr4_16(addr), port));
1501 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len));
1502 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len));
1503 /* prevent warnings about unused arguments */
1504 LWIP_UNUSED_ARG(pcb);
1505 LWIP_UNUSED_ARG(addr);
1506 LWIP_UNUSED_ARG(port);
1508 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL);
1510 if (p->len < DHCP_MIN_REPLY_LEN) {
1511 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP reply message or pbuf too short\n"));
1512 goto free_pbuf_and_return;
1515 if (reply_msg->op != DHCP_BOOTREPLY) {
1516 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));
1517 goto free_pbuf_and_return;
1519 /* iterate through hardware address and match against DHCP message */
1520 for (i = 0; i < netif->hwaddr_len; i++) {
1521 if (netif->hwaddr[i] != reply_msg->chaddr[i]) {
1522 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
1523 ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n",
1524 (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i]));
1525 goto free_pbuf_and_return;
1528 /* match transaction ID against what we expected */
1529 if (ntohl(reply_msg->xid) != dhcp->xid) {
1530 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
1531 ("transaction id mismatch reply_msg->xid(%"X32_F")!=dhcp->xid(%"X32_F")\n",ntohl(reply_msg->xid),dhcp->xid));
1532 goto free_pbuf_and_return;
1534 /* option fields could be unfold? */
1535 if (dhcp_parse_reply(dhcp, p) != ERR_OK) {
1536 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
1537 ("problem unfolding DHCP message - too short on memory?\n"));
1538 goto free_pbuf_and_return;
1541 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n"));
1542 /* obtain pointer to DHCP message type */
1543 if (!dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE)) {
1544 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP_OPTION_MESSAGE_TYPE option not found\n"));
1545 goto free_pbuf_and_return;
1548 /* read DHCP message type */
1549 msg_type = (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE);
1550 /* message type is DHCP ACK? */
1551 if (msg_type == DHCP_ACK) {
1552 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_ACK received\n"));
1553 /* in requesting state? */
1554 if (dhcp->state == DHCP_REQUESTING) {
1555 dhcp_handle_ack(netif);
1556 #if DHCP_DOES_ARP_CHECK
1557 /* check if the acknowledged lease address is already in use */
1560 /* bind interface to the acknowledged lease address */
1564 /* already bound to the given lease address? */
1565 else if ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING)) {
1569 /* received a DHCP_NAK in appropriate state? */
1570 else if ((msg_type == DHCP_NAK) &&
1571 ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REQUESTING) ||
1572 (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING ))) {
1573 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_NAK received\n"));
1574 dhcp_handle_nak(netif);
1576 /* received a DHCP_OFFER in DHCP_SELECTING state? */
1577 else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_SELECTING)) {
1578 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_OFFER received in DHCP_SELECTING state\n"));
1579 dhcp->request_timeout = 0;
1580 /* remember offered lease */
1581 dhcp_handle_offer(netif);
1583 free_pbuf_and_return:
1584 dhcp->msg_in = NULL;
1589 * Create a DHCP request, fill in common headers
1591 * @param netif the netif under DHCP control
1592 * @param dhcp dhcp control struct
1593 * @param message_type message type of the request
1596 dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type)
1599 #ifndef DHCP_GLOBAL_XID
1600 /** default global transaction identifier starting value (easy to match
1601 * with a packet analyser). We simply increment for each new request.
1602 * Predefine DHCP_GLOBAL_XID to a better value or a function call to generate one
1603 * at runtime, any supporting function prototypes can be defined in DHCP_GLOBAL_XID_HEADER */
1604 static u32_t xid = 0xABCD0000;
1607 static u8_t xid_initialised = 0;
1608 if (!xid_initialised) {
1609 xid = DHCP_GLOBAL_XID;
1610 xid_initialised = !xid_initialised;
1613 LWIP_ERROR("dhcp_create_msg: netif != NULL", (netif != NULL), return ERR_ARG;);
1614 LWIP_ERROR("dhcp_create_msg: dhcp != NULL", (dhcp != NULL), return ERR_VAL;);
1615 LWIP_ASSERT("dhcp_create_msg: dhcp->p_out == NULL", dhcp->p_out == NULL);
1616 LWIP_ASSERT("dhcp_create_msg: dhcp->msg_out == NULL", dhcp->msg_out == NULL);
1617 dhcp->p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM);
1618 if (dhcp->p_out == NULL) {
1619 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
1620 ("dhcp_create_msg(): could not allocate pbuf\n"));
1623 LWIP_ASSERT("dhcp_create_msg: check that first pbuf can hold struct dhcp_msg",
1624 (dhcp->p_out->len >= sizeof(struct dhcp_msg)));
1626 /* reuse transaction identifier in retransmissions */
1627 if (dhcp->tries == 0) {
1631 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE,
1632 ("transaction id xid(%"X32_F")\n", xid));
1634 dhcp->msg_out = (struct dhcp_msg *)dhcp->p_out->payload;
1636 dhcp->msg_out->op = DHCP_BOOTREQUEST;
1637 /* TODO: make link layer independent */
1638 dhcp->msg_out->htype = DHCP_HTYPE_ETH;
1639 dhcp->msg_out->hlen = netif->hwaddr_len;
1640 dhcp->msg_out->hops = 0;
1641 dhcp->msg_out->xid = htonl(dhcp->xid);
1642 dhcp->msg_out->secs = 0;
1643 /* we don't need the broadcast flag since we can receive unicast traffic
1644 before being fully configured! */
1645 dhcp->msg_out->flags = 0;
1646 ip_addr_set_zero(&dhcp->msg_out->ciaddr);
1647 /* set ciaddr to netif->ip_addr based on message_type and state */
1648 if ((message_type == DHCP_INFORM) || (message_type == DHCP_DECLINE) ||
1649 ((message_type == DHCP_REQUEST) && /* DHCP_BOUND not used for sending! */
1650 ((dhcp->state==DHCP_RENEWING) || dhcp->state==DHCP_REBINDING))) {
1651 ip_addr_copy(dhcp->msg_out->ciaddr, netif->ip_addr);
1653 ip_addr_set_zero(&dhcp->msg_out->yiaddr);
1654 ip_addr_set_zero(&dhcp->msg_out->siaddr);
1655 ip_addr_set_zero(&dhcp->msg_out->giaddr);
1656 for (i = 0; i < DHCP_CHADDR_LEN; i++) {
1657 /* copy netif hardware address, pad with zeroes */
1658 dhcp->msg_out->chaddr[i] = (i < netif->hwaddr_len) ? netif->hwaddr[i] : 0/* pad byte*/;
1660 for (i = 0; i < DHCP_SNAME_LEN; i++) {
1661 dhcp->msg_out->sname[i] = 0;
1663 for (i = 0; i < DHCP_FILE_LEN; i++) {
1664 dhcp->msg_out->file[i] = 0;
1666 dhcp->msg_out->cookie = PP_HTONL(DHCP_MAGIC_COOKIE);
1667 dhcp->options_out_len = 0;
1668 /* fill options field with an incrementing array (for debugging purposes) */
1669 for (i = 0; i < DHCP_OPTIONS_LEN; i++) {
1670 dhcp->msg_out->options[i] = (u8_t)i; /* for debugging only, no matter if truncated */
1672 /* Add option MESSAGE_TYPE */
1673 dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
1674 dhcp_option_byte(dhcp, message_type);
1679 * Free previously allocated memory used to send a DHCP request.
1681 * @param dhcp the dhcp struct to free the request from
1684 dhcp_delete_msg(struct dhcp *dhcp)
1686 LWIP_ERROR("dhcp_delete_msg: dhcp != NULL", (dhcp != NULL), return;);
1687 LWIP_ASSERT("dhcp_delete_msg: dhcp->p_out != NULL", dhcp->p_out != NULL);
1688 LWIP_ASSERT("dhcp_delete_msg: dhcp->msg_out != NULL", dhcp->msg_out != NULL);
1689 if (dhcp->p_out != NULL) {
1690 pbuf_free(dhcp->p_out);
1693 dhcp->msg_out = NULL;
1697 * Add a DHCP message trailer
1699 * Adds the END option to the DHCP message, and if
1700 * necessary, up to three padding bytes.
1702 * @param dhcp DHCP state structure
1705 dhcp_option_trailer(struct dhcp *dhcp)
1707 LWIP_ERROR("dhcp_option_trailer: dhcp != NULL", (dhcp != NULL), return;);
1708 LWIP_ASSERT("dhcp_option_trailer: dhcp->msg_out != NULL\n", dhcp->msg_out != NULL);
1709 LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN);
1710 dhcp->msg_out->options[dhcp->options_out_len++] = DHCP_OPTION_END;
1711 /* packet is too small, or not 4 byte aligned? */
1712 while ((dhcp->options_out_len < DHCP_MIN_OPTIONS_LEN) || (dhcp->options_out_len & 3)) {
1713 /* LWIP_DEBUGF(DHCP_DEBUG,("dhcp_option_trailer:dhcp->options_out_len=%"U16_F", DHCP_OPTIONS_LEN=%"U16_F, dhcp->options_out_len, DHCP_OPTIONS_LEN)); */
1714 LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN);
1715 /* add a fill/padding byte */
1716 dhcp->msg_out->options[dhcp->options_out_len++] = 0;
1720 #endif /* LWIP_DHCP */