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"
79 #include "lwip/dhcp.h"
80 #include "lwip/autoip.h"
82 #include "netif/etharp.h"
86 /** DHCP_CREATE_RAND_XID: if this is set to 1, the xid is created using
87 * LWIP_RAND() (this overrides DHCP_GLOBAL_XID)
89 #ifndef DHCP_CREATE_RAND_XID
90 #define DHCP_CREATE_RAND_XID 1
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()
98 #ifdef DHCP_GLOBAL_XID_HEADER
99 #include DHCP_GLOBAL_XID_HEADER /* include optional starting XID generation prototypes */
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
109 #define REBOOT_TRIES 2
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
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)
127 /** Holds the decoded option values, only valid while in dhcp_recv.
128 @todo: move this into struct dhcp? */
129 u32_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? */
133 u8_t dhcp_rx_options_given[DHCP_OPTION_IDX_MAX];
135 #ifdef DHCP_GLOBAL_XID
137 static u8_t xid_initialised;
138 #endif /* DHCP_GLOBAL_XID */
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))
148 /* DHCP client state machine functions */
149 static err_t dhcp_discover(struct netif *netif);
150 static err_t dhcp_select(struct netif *netif);
151 static void dhcp_bind(struct netif *netif);
152 #if DHCP_DOES_ARP_CHECK
153 static err_t dhcp_decline(struct netif *netif);
154 #endif /* DHCP_DOES_ARP_CHECK */
155 static err_t dhcp_rebind(struct netif *netif);
156 static err_t dhcp_reboot(struct netif *netif);
157 static void dhcp_set_state(struct dhcp *dhcp, u8_t new_state);
159 /* receive, unfold, parse and free incoming messages */
160 static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port);
162 /* set the DHCP timers */
163 static void dhcp_timeout(struct netif *netif);
164 static void dhcp_t1_timeout(struct netif *netif);
165 static void dhcp_t2_timeout(struct netif *netif);
167 /* build outgoing messages */
168 /* create a DHCP message, fill in common headers */
169 static err_t dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type);
170 /* free a DHCP request */
171 static void dhcp_delete_msg(struct dhcp *dhcp);
172 /* add a DHCP option (type, then length in bytes) */
173 static void dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len);
174 /* add option values */
175 static void dhcp_option_byte(struct dhcp *dhcp, u8_t value);
176 static void dhcp_option_short(struct dhcp *dhcp, u16_t value);
177 static void dhcp_option_long(struct dhcp *dhcp, u32_t value);
178 #if LWIP_NETIF_HOSTNAME
179 static 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 */
182 static void dhcp_option_trailer(struct dhcp *dhcp);
185 * Back-off the DHCP client (because of a received NAK response).
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.
191 * We clear any existing set IP address and restart DHCP negotiation
192 * afresh (as per RFC2131 3.2.3).
194 * @param netif the netif under DHCP control
197 dhcp_handle_nak(struct netif *netif)
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);
214 #if DHCP_DOES_ARP_CHECK
216 * Checks if the offered IP address is already in use.
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.
222 * @param netif the netif under DHCP control
225 dhcp_check(struct netif *netif)
227 struct dhcp *dhcp = netif->dhcp;
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"));
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));
244 #endif /* DHCP_DOES_ARP_CHECK */
247 * Remember the configuration offered by a DHCP server.
249 * @param netif the netif under DHCP control
252 dhcp_handle_offer(struct netif *netif)
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)));
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));
275 * Select a DHCP server offer out of all offers.
277 * Simply select the first offer received.
279 * @param netif the netif under DHCP control
280 * @return lwIP specific error (see error.h)
283 dhcp_select(struct netif *netif)
285 struct dhcp *dhcp = netif->dhcp;
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);
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));
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)));
302 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4);
303 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->server_ip_addr)));
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);
311 #if LWIP_NETIF_HOSTNAME
312 dhcp_option_hostname(dhcp, netif);
313 #endif /* LWIP_NETIF_HOSTNAME */
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);
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"));
324 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_select: could not allocate DHCP request\n"));
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));
334 * The DHCP timer that checks for lease renewal/rebind timeouts.
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);
357 /* proceed to next netif */
363 * DHCP transaction timeout handling
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.
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--;
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 */
388 /* proceed to next network interface */
394 * A DHCP negotiation transaction, or ARP request, has timed out.
396 * The timer that was started with the DHCP or ARP request has
397 * timed out, indicating no response was received in time.
399 * @param netif the netif under DHCP control
402 dhcp_timeout(struct netif *netif)
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) {
416 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, releasing, restarting\n"));
418 dhcp_discover(netif);
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) {
426 /* no ARP replies on the offered address,
427 looks like the IP address is indeed free */
429 /* bind the interface to the offered address */
432 #endif /* DHCP_DOES_ARP_CHECK */
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 */
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) {
446 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): RELEASING, DISCOVERING\n"));
448 dhcp_discover(netif);
450 } else if (dhcp->state == DHCP_REBOOTING) {
451 if (dhcp->tries < REBOOT_TRIES) {
454 dhcp_discover(netif);
460 * The renewal period has timed out.
462 * @param netif the netif under DHCP control
465 dhcp_t1_timeout(struct netif *netif)
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 */
482 * The rebind period has timed out.
484 * @param netif the netif under DHCP control
487 dhcp_t2_timeout(struct netif *netif)
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 */
503 * Handle a DHCP ACK packet
505 * @param netif the netif under DHCP control
508 dhcp_handle_ack(struct netif *netif)
510 struct dhcp *dhcp = netif->dhcp;
513 #endif /* LWIP_DNS */
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 */
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);
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);
532 /* calculate safe periods for renewal */
533 dhcp->offered_t1_renew = dhcp->offered_t0_lease / 2;
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);
541 /* calculate safe periods for rebinding */
542 dhcp->offered_t2_rebind = dhcp->offered_t0_lease;
545 /* (y)our internet address */
546 ip_addr_copy(dhcp->offered_ip_addr, dhcp->msg_in->yiaddr);
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 */
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;
560 dhcp->subnet_mask_given = 0;
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)));
570 for(n = 0; (n < DNS_MAX_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n); n++) {
572 ip4_addr_set_u32(&dns_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n)));
573 dns_setserver(n, &dns_addr);
575 #endif /* LWIP_DNS */
578 /** Set a statically allocated struct dhcp to work with.
579 * Using this prevents dhcp_start to allocate it using mem_malloc.
581 * @param netif the netif for which to set the struct dhcp
582 * @param dhcp (uninitialised) dhcp struct allocated by the application
585 dhcp_set_struct(struct netif *netif, struct dhcp *dhcp)
587 LWIP_ASSERT("netif != NULL", netif != NULL);
588 LWIP_ASSERT("dhcp != NULL", dhcp != NULL);
589 LWIP_ASSERT("netif already has a struct dhcp set", netif->dhcp == NULL);
591 /* clear data structure */
592 memset(dhcp, 0, sizeof(struct dhcp));
593 /* dhcp_set_state(&dhcp, DHCP_OFF); */
597 /** Removes a struct dhcp from a netif.
599 * ATTENTION: Only use this when not using dhcp_set_struct() to allocate the
600 * struct dhcp since the memory is passed back to the heap.
602 * @param netif the netif from which to remove the struct dhcp
604 void dhcp_cleanup(struct netif *netif)
606 LWIP_ASSERT("netif != NULL", netif != NULL);
608 if (netif->dhcp != NULL) {
609 mem_free(netif->dhcp);
615 * Start DHCP negotiation for a network interface.
617 * If no DHCP client instance was attached to this interface,
618 * a new client is created first. If a DHCP client instance
619 * was already present, it restarts negotiation.
621 * @param netif The lwIP network interface
622 * @return lwIP error code
623 * - ERR_OK - No error
624 * - ERR_MEM - Out of memory
627 dhcp_start(struct netif *netif)
630 err_t result = ERR_OK;
632 LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;);
634 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));
635 /* Remove the flag that says this netif is handled by DHCP,
636 it is set when we succeeded starting. */
637 netif->flags &= ~NETIF_FLAG_DHCP;
639 /* check hwtype of the netif */
640 if ((netif->flags & NETIF_FLAG_ETHARP) == 0) {
641 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): No ETHARP netif\n"));
645 /* check MTU of the netif */
646 if (netif->mtu < DHCP_MAX_MSG_LEN_MIN_REQUIRED) {
647 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): Cannot use this netif with DHCP: MTU is too small\n"));
651 /* no DHCP client attached yet? */
653 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting new DHCP client\n"));
654 dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp));
656 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n"));
659 /* store this dhcp client in the netif */
661 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): allocated dhcp"));
662 /* already has DHCP client attached */
664 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(): restarting DHCP configuration\n"));
665 if (dhcp->pcb != NULL) {
666 udp_remove(dhcp->pcb);
668 LWIP_ASSERT("pbuf p_out wasn't freed", dhcp->p_out == NULL);
669 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL );
672 /* clear data structure */
673 memset(dhcp, 0, sizeof(struct dhcp));
674 /* dhcp_set_state(&dhcp, DHCP_OFF); */
675 /* allocate UDP PCB */
676 dhcp->pcb = udp_new();
677 if (dhcp->pcb == NULL) {
678 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not obtain pcb\n"));
681 ip_set_option(dhcp->pcb, SOF_BROADCAST);
682 /* set up local and remote port for the pcb */
683 udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT);
684 udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT);
685 /* set up the recv callback and argument */
686 udp_recv(dhcp->pcb, dhcp_recv, netif);
687 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n"));
688 /* (re)start the DHCP negotiation */
689 result = dhcp_discover(netif);
690 if (result != ERR_OK) {
691 /* free resources allocated above */
695 /* Set the flag that says this netif is handled by DHCP. */
696 netif->flags |= NETIF_FLAG_DHCP;
701 * Inform a DHCP server of our manual configuration.
703 * This informs DHCP servers of our fixed IP address configuration
704 * by sending an INFORM message. It does not involve DHCP address
705 * configuration, it is just here to be nice to the network.
707 * @param netif The lwIP network interface
710 dhcp_inform(struct netif *netif)
713 err_t result = ERR_OK;
716 LWIP_ERROR("netif != NULL", (netif != NULL), return;);
718 memset(&dhcp, 0, sizeof(struct dhcp));
719 dhcp_set_state(&dhcp, DHCP_INFORM);
721 if ((netif->dhcp != NULL) && (netif->dhcp->pcb != NULL)) {
722 /* re-use existing pcb */
723 pcb = netif->dhcp->pcb;
727 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform(): could not obtain pcb"));
731 ip_set_option(dhcp.pcb, SOF_BROADCAST);
732 udp_bind(dhcp.pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT);
733 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_inform(): created new udp pcb\n"));
735 /* create and initialize the DHCP message header */
736 result = dhcp_create_msg(netif, &dhcp, DHCP_INFORM);
737 if (result == ERR_OK) {
738 dhcp_option(&dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
739 dhcp_option_short(&dhcp, DHCP_MAX_MSG_LEN(netif));
741 dhcp_option_trailer(&dhcp);
743 pbuf_realloc(dhcp.p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp.options_out_len);
745 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n"));
746 udp_sendto_if(pcb, dhcp.p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
747 dhcp_delete_msg(&dhcp);
749 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform: could not allocate DHCP request\n"));
752 if (dhcp.pcb != NULL) {
753 /* otherwise, the existing pcb was used */
754 udp_remove(dhcp.pcb);
758 /** Handle a possible change in the network configuration.
760 * This enters the REBOOTING state to verify that the currently bound
761 * address is still valid.
764 dhcp_network_changed(struct netif *netif)
766 struct dhcp *dhcp = netif->dhcp;
769 switch (dhcp->state) {
774 netif_set_down(netif);
783 #if LWIP_DHCP_AUTOIP_COOP
784 if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
786 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
788 #endif /* LWIP_DHCP_AUTOIP_COOP */
789 dhcp_discover(netif);
794 #if DHCP_DOES_ARP_CHECK
796 * Match an ARP reply with the offered IP address.
798 * @param netif the network interface on which the reply was received
799 * @param addr The IP address we received a reply from
801 void dhcp_arp_reply(struct netif *netif, ip_addr_t *addr)
803 LWIP_ERROR("netif != NULL", (netif != NULL), return;);
804 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_arp_reply()\n"));
805 /* is a DHCP client doing an ARP check? */
806 if ((netif->dhcp != NULL) && (netif->dhcp->state == DHCP_CHECKING)) {
807 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_arp_reply(): CHECKING, arp reply for 0x%08"X32_F"\n",
808 ip4_addr_get_u32(addr)));
809 /* did a host respond with the address we
810 were offered by the DHCP server? */
811 if (ip_addr_cmp(addr, &netif->dhcp->offered_ip_addr)) {
812 /* we will not accept the offered address */
813 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
814 ("dhcp_arp_reply(): arp reply matched with offered address, declining\n"));
821 * Decline an offered lease.
823 * Tell the DHCP server we do not accept the offered address.
824 * One reason to decline the lease is when we find out the address
825 * is already in use by another host (through ARP).
827 * @param netif the netif under DHCP control
830 dhcp_decline(struct netif *netif)
832 struct dhcp *dhcp = netif->dhcp;
833 err_t result = ERR_OK;
835 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline()\n"));
836 dhcp_set_state(dhcp, DHCP_BACKING_OFF);
837 /* create and initialize the DHCP message header */
838 result = dhcp_create_msg(netif, dhcp, DHCP_DECLINE);
839 if (result == ERR_OK) {
840 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
841 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
843 dhcp_option_trailer(dhcp);
844 /* resize pbuf to reflect true size of options */
845 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
847 /* per section 4.4.4, broadcast DECLINE messages */
848 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
849 dhcp_delete_msg(dhcp);
850 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_decline: BACKING OFF\n"));
852 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
853 ("dhcp_decline: could not allocate DHCP request\n"));
857 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
858 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs));
861 #endif /* DHCP_DOES_ARP_CHECK */
865 * Start the DHCP process, discover a DHCP server.
867 * @param netif the netif under DHCP control
870 dhcp_discover(struct netif *netif)
872 struct dhcp *dhcp = netif->dhcp;
873 err_t result = ERR_OK;
875 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover()\n"));
876 ip_addr_set_any(&dhcp->offered_ip_addr);
877 dhcp_set_state(dhcp, DHCP_SELECTING);
878 /* create and initialize the DHCP message header */
879 result = dhcp_create_msg(netif, dhcp, DHCP_DISCOVER);
880 if (result == ERR_OK) {
881 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n"));
883 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
884 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif));
886 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/);
887 dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK);
888 dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER);
889 dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST);
890 dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER);
892 dhcp_option_trailer(dhcp);
894 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: realloc()ing\n"));
895 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
897 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, DHCP_SERVER_PORT)\n"));
898 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
899 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()ing\n"));
900 dhcp_delete_msg(dhcp);
901 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover: SELECTING\n"));
903 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_discover: could not allocate DHCP request\n"));
906 #if LWIP_DHCP_AUTOIP_COOP
907 if(dhcp->tries >= LWIP_DHCP_AUTOIP_COOP_TRIES && dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_OFF) {
908 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_ON;
911 #endif /* LWIP_DHCP_AUTOIP_COOP */
912 msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000;
913 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
914 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs));
920 * Bind the interface to the offered IP address.
922 * @param netif network interface to bind to the offered address
925 dhcp_bind(struct netif *netif)
929 ip_addr_t sn_mask, gw_addr;
930 LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;);
932 LWIP_ERROR("dhcp_bind: dhcp != NULL", (dhcp != NULL), return;);
933 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));
935 /* temporary DHCP lease? */
936 if (dhcp->offered_t1_renew != 0xffffffffUL) {
937 /* set renewal period timer */
938 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew));
939 timeout = (dhcp->offered_t1_renew + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS;
940 if(timeout > 0xffff) {
943 dhcp->t1_timeout = (u16_t)timeout;
944 if (dhcp->t1_timeout == 0) {
945 dhcp->t1_timeout = 1;
947 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew*1000));
949 /* set renewal period timer */
950 if (dhcp->offered_t2_rebind != 0xffffffffUL) {
951 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind));
952 timeout = (dhcp->offered_t2_rebind + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS;
953 if(timeout > 0xffff) {
956 dhcp->t2_timeout = (u16_t)timeout;
957 if (dhcp->t2_timeout == 0) {
958 dhcp->t2_timeout = 1;
960 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 /* If we have sub 1 minute lease, t2 and t1 will kick in at the same time. */
964 if ((dhcp->t1_timeout >= dhcp->t2_timeout) && (dhcp->t2_timeout > 0)) {
965 dhcp->t1_timeout = 0;
968 if (dhcp->subnet_mask_given) {
969 /* copy offered network mask */
970 ip_addr_copy(sn_mask, dhcp->offered_sn_mask);
972 /* subnet mask not given, choose a safe subnet mask given the network class */
973 u8_t first_octet = ip4_addr1(&dhcp->offered_ip_addr);
974 if (first_octet <= 127) {
975 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xff000000UL));
976 } else if (first_octet >= 192) {
977 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffffff00UL));
979 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffff0000UL));
983 ip_addr_copy(gw_addr, dhcp->offered_gw_addr);
984 /* gateway address not given? */
985 if (ip_addr_isany(&gw_addr)) {
986 /* copy network address */
987 ip_addr_get_network(&gw_addr, &dhcp->offered_ip_addr, &sn_mask);
988 /* use first host address on network as gateway */
989 ip4_addr_set_u32(&gw_addr, ip4_addr_get_u32(&gw_addr) | PP_HTONL(0x00000001UL));
992 #if LWIP_DHCP_AUTOIP_COOP
993 if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
995 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
997 #endif /* LWIP_DHCP_AUTOIP_COOP */
999 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): IP: 0x%08"X32_F"\n",
1000 ip4_addr_get_u32(&dhcp->offered_ip_addr)));
1001 netif_set_ipaddr(netif, &dhcp->offered_ip_addr);
1002 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): SN: 0x%08"X32_F"\n",
1003 ip4_addr_get_u32(&sn_mask)));
1004 netif_set_netmask(netif, &sn_mask);
1005 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): GW: 0x%08"X32_F"\n",
1006 ip4_addr_get_u32(&gw_addr)));
1007 netif_set_gw(netif, &gw_addr);
1008 /* bring the interface up */
1009 netif_set_up(netif);
1010 /* netif is now bound to DHCP leased address */
1011 dhcp_set_state(dhcp, DHCP_BOUND);
1015 * Renew an existing DHCP lease at the involved DHCP server.
1017 * @param netif network interface which must renew its lease
1020 dhcp_renew(struct netif *netif)
1022 struct dhcp *dhcp = netif->dhcp;
1025 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_renew()\n"));
1026 dhcp_set_state(dhcp, DHCP_RENEWING);
1028 /* create and initialize the DHCP message header */
1029 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST);
1030 if (result == ERR_OK) {
1031 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1032 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif));
1035 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
1036 dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr));
1040 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4);
1041 dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr));
1044 #if LWIP_NETIF_HOSTNAME
1045 dhcp_option_hostname(dhcp, netif);
1046 #endif /* LWIP_NETIF_HOSTNAME */
1048 /* append DHCP message trailer */
1049 dhcp_option_trailer(dhcp);
1051 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
1053 udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif);
1054 dhcp_delete_msg(dhcp);
1056 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew: RENEWING\n"));
1058 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_renew: could not allocate DHCP request\n"));
1061 /* back-off on retries, but to a maximum of 20 seconds */
1062 msecs = dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000;
1063 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
1064 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs));
1069 * Rebind with a DHCP server for an existing DHCP lease.
1071 * @param netif network interface which must rebind with a DHCP server
1074 dhcp_rebind(struct netif *netif)
1076 struct dhcp *dhcp = netif->dhcp;
1079 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n"));
1080 dhcp_set_state(dhcp, DHCP_REBINDING);
1082 /* create and initialize the DHCP message header */
1083 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST);
1084 if (result == ERR_OK) {
1085 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1086 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif));
1088 #if LWIP_NETIF_HOSTNAME
1089 dhcp_option_hostname(dhcp, netif);
1090 #endif /* LWIP_NETIF_HOSTNAME */
1093 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
1094 dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr));
1096 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4);
1097 dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr));
1100 dhcp_option_trailer(dhcp);
1102 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
1104 /* broadcast to server */
1105 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
1106 dhcp_delete_msg(dhcp);
1107 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n"));
1109 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_rebind: could not allocate DHCP request\n"));
1112 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000;
1113 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
1114 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs));
1119 * Enter REBOOTING state to verify an existing lease
1121 * @param netif network interface which must reboot
1124 dhcp_reboot(struct netif *netif)
1126 struct dhcp *dhcp = netif->dhcp;
1129 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n"));
1130 dhcp_set_state(dhcp, DHCP_REBOOTING);
1132 /* create and initialize the DHCP message header */
1133 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST);
1134 if (result == ERR_OK) {
1135 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1136 dhcp_option_short(dhcp, 576);
1138 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
1139 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
1141 dhcp_option_trailer(dhcp);
1143 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
1145 /* broadcast to server */
1146 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
1147 dhcp_delete_msg(dhcp);
1148 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot: REBOOTING\n"));
1150 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_reboot: could not allocate DHCP request\n"));
1153 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000;
1154 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
1155 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot(): set request timeout %"U16_F" msecs\n", msecs));
1161 * Release a DHCP lease.
1163 * @param netif network interface which must release its lease
1166 dhcp_release(struct netif *netif)
1168 struct dhcp *dhcp = netif->dhcp;
1171 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release()\n"));
1176 /* idle DHCP client */
1177 dhcp_set_state(dhcp, DHCP_OFF);
1178 /* clean old DHCP offer */
1179 ip_addr_set_zero(&dhcp->server_ip_addr);
1180 ip_addr_set_zero(&dhcp->offered_ip_addr);
1181 ip_addr_set_zero(&dhcp->offered_sn_mask);
1182 ip_addr_set_zero(&dhcp->offered_gw_addr);
1183 #if LWIP_DHCP_BOOTP_FILE
1184 ip_addr_set_zero(&dhcp->offered_si_addr);
1185 #endif /* LWIP_DHCP_BOOTP_FILE */
1186 dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0;
1188 /* create and initialize the DHCP message header */
1189 result = dhcp_create_msg(netif, dhcp, DHCP_RELEASE);
1190 if (result == ERR_OK) {
1191 dhcp_option_trailer(dhcp);
1193 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);
1195 udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif);
1196 dhcp_delete_msg(dhcp);
1197 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_OFF\n"));
1199 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n"));
1202 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000;
1203 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
1204 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release(): set request timeout %"U16_F" msecs\n", msecs));
1205 /* bring the interface down */
1206 netif_set_down(netif);
1207 /* remove IP address from interface */
1208 netif_set_ipaddr(netif, IP_ADDR_ANY);
1209 netif_set_gw(netif, IP_ADDR_ANY);
1210 netif_set_netmask(netif, IP_ADDR_ANY);
1216 * Remove the DHCP client from the interface.
1218 * @param netif The network interface to stop DHCP on
1221 dhcp_stop(struct netif *netif)
1224 LWIP_ERROR("dhcp_stop: netif != NULL", (netif != NULL), return;);
1226 /* Remove the flag that says this netif is handled by DHCP. */
1227 netif->flags &= ~NETIF_FLAG_DHCP;
1229 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_stop()\n"));
1230 /* netif is DHCP configured? */
1232 #if LWIP_DHCP_AUTOIP_COOP
1233 if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
1235 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
1237 #endif /* LWIP_DHCP_AUTOIP_COOP */
1239 if (dhcp->pcb != NULL) {
1240 udp_remove(dhcp->pcb);
1243 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL);
1244 dhcp_set_state(dhcp, DHCP_OFF);
1249 * Set the DHCP state of a DHCP client.
1251 * If the state changed, reset the number of tries.
1254 dhcp_set_state(struct dhcp *dhcp, u8_t new_state)
1256 if (new_state != dhcp->state) {
1257 dhcp->state = new_state;
1259 dhcp->request_timeout = 0;
1264 * Concatenate an option type and length field to the outgoing
1269 dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len)
1271 LWIP_ASSERT("dhcp_option: dhcp->options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN);
1272 dhcp->msg_out->options[dhcp->options_out_len++] = option_type;
1273 dhcp->msg_out->options[dhcp->options_out_len++] = option_len;
1276 * Concatenate a single byte to the outgoing DHCP message.
1280 dhcp_option_byte(struct dhcp *dhcp, u8_t value)
1282 LWIP_ASSERT("dhcp_option_byte: dhcp->options_out_len < DHCP_OPTIONS_LEN", dhcp->options_out_len < DHCP_OPTIONS_LEN);
1283 dhcp->msg_out->options[dhcp->options_out_len++] = value;
1287 dhcp_option_short(struct dhcp *dhcp, u16_t value)
1289 LWIP_ASSERT("dhcp_option_short: dhcp->options_out_len + 2 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U <= DHCP_OPTIONS_LEN);
1290 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff00U) >> 8);
1291 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t) (value & 0x00ffU);
1295 dhcp_option_long(struct dhcp *dhcp, u32_t value)
1297 LWIP_ASSERT("dhcp_option_long: dhcp->options_out_len + 4 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 4U <= DHCP_OPTIONS_LEN);
1298 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24);
1299 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16);
1300 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8);
1301 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x000000ffUL));
1304 #if LWIP_NETIF_HOSTNAME
1306 dhcp_option_hostname(struct dhcp *dhcp, struct netif *netif)
1308 if (netif->hostname != NULL) {
1309 size_t namelen = strlen(netif->hostname);
1312 const char *p = netif->hostname;
1313 /* Shrink len to available bytes (need 2 bytes for OPTION_HOSTNAME
1314 and 1 byte for trailer) */
1315 size_t available = DHCP_OPTIONS_LEN - dhcp->options_out_len - 3;
1316 LWIP_ASSERT("DHCP: hostname is too long!", namelen <= available);
1317 len = LWIP_MIN(namelen, available);
1318 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, len);
1320 dhcp_option_byte(dhcp, *p++);
1325 #endif /* LWIP_NETIF_HOSTNAME */
1328 * Extract the DHCP message and the DHCP options.
1330 * Extract the DHCP message and the DHCP options, each into a contiguous
1331 * piece of memory. As a DHCP message is variable sized by its options,
1332 * and also allows overriding some fields for options, the easy approach
1333 * is to first unfold the options into a conitguous piece of memory, and
1334 * use that further on.
1338 dhcp_parse_reply(struct dhcp *dhcp, struct pbuf *p)
1344 u16_t options_idx_max;
1346 int parse_file_as_options = 0;
1347 int parse_sname_as_options = 0;
1349 /* clear received options */
1350 dhcp_clear_all_options(dhcp);
1351 /* check that beginning of dhcp_msg (up to and including chaddr) is in first pbuf */
1352 if (p->len < DHCP_SNAME_OFS) {
1355 dhcp->msg_in = (struct dhcp_msg *)p->payload;
1356 #if LWIP_DHCP_BOOTP_FILE
1357 /* clear boot file name */
1358 dhcp->boot_file_name[0] = 0;
1359 #endif /* LWIP_DHCP_BOOTP_FILE */
1363 /* start with options field */
1364 options_idx = DHCP_OPTIONS_OFS;
1365 /* parse options to the end of the received packet */
1366 options_idx_max = p->tot_len;
1369 while((q != NULL) && (options_idx >= q->len)) {
1370 options_idx -= q->len;
1371 options_idx_max -= q->len;
1377 offset = options_idx;
1378 offset_max = options_idx_max;
1379 options = (u8_t*)q->payload;
1380 /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */
1381 while((q != NULL) && (options[offset] != DHCP_OPTION_END) && (offset < offset_max)) {
1382 u8_t op = options[offset];
1384 u8_t decode_len = 0;
1385 int decode_idx = -1;
1386 u16_t val_offset = offset + 2;
1387 /* len byte might be in the next pbuf */
1388 if (offset + 1 < q->len) {
1389 len = options[offset + 1];
1391 len = (q->next != NULL ? ((u8_t*)q->next->payload)[0] : 0);
1393 /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F, msg_offset, q->len)); */
1396 /* case(DHCP_OPTION_END): handled above */
1397 case(DHCP_OPTION_PAD):
1398 /* special option: no len encoded */
1399 decode_len = len = 0;
1400 /* will be increased below */
1403 case(DHCP_OPTION_SUBNET_MASK):
1404 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;);
1405 decode_idx = DHCP_OPTION_IDX_SUBNET_MASK;
1407 case(DHCP_OPTION_ROUTER):
1408 decode_len = 4; /* only copy the first given router */
1409 LWIP_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;);
1410 decode_idx = DHCP_OPTION_IDX_ROUTER;
1412 case(DHCP_OPTION_DNS_SERVER):
1413 /* special case: there might be more than one server */
1414 LWIP_ERROR("len % 4 == 0", len % 4 == 0, return ERR_VAL;);
1415 /* limit number of DNS servers */
1416 decode_len = LWIP_MIN(len, 4 * DNS_MAX_SERVERS);
1417 LWIP_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;);
1418 decode_idx = DHCP_OPTION_IDX_DNS_SERVER;
1420 case(DHCP_OPTION_LEASE_TIME):
1421 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;);
1422 decode_idx = DHCP_OPTION_IDX_LEASE_TIME;
1424 case(DHCP_OPTION_OVERLOAD):
1425 LWIP_ERROR("len == 1", len == 1, return ERR_VAL;);
1426 decode_idx = DHCP_OPTION_IDX_OVERLOAD;
1428 case(DHCP_OPTION_MESSAGE_TYPE):
1429 LWIP_ERROR("len == 1", len == 1, return ERR_VAL;);
1430 decode_idx = DHCP_OPTION_IDX_MSG_TYPE;
1432 case(DHCP_OPTION_SERVER_ID):
1433 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;);
1434 decode_idx = DHCP_OPTION_IDX_SERVER_ID;
1436 case(DHCP_OPTION_T1):
1437 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;);
1438 decode_idx = DHCP_OPTION_IDX_T1;
1440 case(DHCP_OPTION_T2):
1441 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;);
1442 decode_idx = DHCP_OPTION_IDX_T2;
1446 LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", op));
1450 if (decode_len > 0) {
1454 LWIP_ASSERT("check decode_idx", decode_idx >= 0 && decode_idx < DHCP_OPTION_IDX_MAX);
1455 if (!dhcp_option_given(dhcp, decode_idx)) {
1456 copy_len = LWIP_MIN(decode_len, 4);
1457 pbuf_copy_partial(q, &value, copy_len, val_offset);
1458 if (decode_len > 4) {
1459 /* decode more than one u32_t */
1460 LWIP_ERROR("decode_len % 4 == 0", decode_len % 4 == 0, return ERR_VAL;);
1461 dhcp_got_option(dhcp, decode_idx);
1462 dhcp_set_option_value(dhcp, decode_idx, htonl(value));
1467 } else if (decode_len == 4) {
1468 value = ntohl(value);
1470 LWIP_ERROR("invalid decode_len", decode_len == 1, return ERR_VAL;);
1471 value = ((u8_t*)&value)[0];
1473 dhcp_got_option(dhcp, decode_idx);
1474 dhcp_set_option_value(dhcp, decode_idx, value);
1477 if (offset >= q->len) {
1479 offset_max -= q->len;
1480 if ((offset < offset_max) && offset_max) {
1482 LWIP_ASSERT("next pbuf was null", q);
1483 options = (u8_t*)q->payload;
1485 /* We've run out of bytes, probably no end marker. Don't proceed. */
1490 /* is this an overloaded message? */
1491 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_OVERLOAD)) {
1492 u32_t overload = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_OVERLOAD);
1493 dhcp_clear_option(dhcp, DHCP_OPTION_IDX_OVERLOAD);
1494 if (overload == DHCP_OVERLOAD_FILE) {
1495 parse_file_as_options = 1;
1496 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded file field\n"));
1497 } else if (overload == DHCP_OVERLOAD_SNAME) {
1498 parse_sname_as_options = 1;
1499 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname field\n"));
1500 } else if (overload == DHCP_OVERLOAD_SNAME_FILE) {
1501 parse_sname_as_options = 1;
1502 parse_file_as_options = 1;
1503 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname and file field\n"));
1505 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("invalid overload option: %d\n", (int)overload));
1507 #if LWIP_DHCP_BOOTP_FILE
1508 if (!parse_file_as_options) {
1509 /* only do this for ACK messages */
1510 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) &&
1511 (dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK))
1512 /* copy bootp file name, don't care for sname (server hostname) */
1513 pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS);
1514 /* make sure the string is really NULL-terminated */
1515 dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0;
1517 #endif /* LWIP_DHCP_BOOTP_FILE */
1519 if (parse_file_as_options) {
1520 /* if both are overloaded, parse file first and then sname (RFC 2131 ch. 4.1) */
1521 parse_file_as_options = 0;
1522 options_idx = DHCP_FILE_OFS;
1523 options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN;
1525 } else if (parse_sname_as_options) {
1526 parse_sname_as_options = 0;
1527 options_idx = DHCP_SNAME_OFS;
1528 options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN;
1535 * If an incoming DHCP message is in response to us, then trigger the state machine
1538 dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port)
1540 struct netif *netif = (struct netif *)arg;
1541 struct dhcp *dhcp = netif->dhcp;
1542 struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload;
1545 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,
1546 ip4_addr1_16(addr), ip4_addr2_16(addr), ip4_addr3_16(addr), ip4_addr4_16(addr), port));
1547 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len));
1548 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len));
1549 /* prevent warnings about unused arguments */
1550 LWIP_UNUSED_ARG(pcb);
1551 LWIP_UNUSED_ARG(addr);
1552 LWIP_UNUSED_ARG(port);
1554 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL);
1556 if (p->len < DHCP_MIN_REPLY_LEN) {
1557 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP reply message or pbuf too short\n"));
1558 goto free_pbuf_and_return;
1561 if (reply_msg->op != DHCP_BOOTREPLY) {
1562 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));
1563 goto free_pbuf_and_return;
1565 /* iterate through hardware address and match against DHCP message */
1566 for (i = 0; i < netif->hwaddr_len; i++) {
1567 if (netif->hwaddr[i] != reply_msg->chaddr[i]) {
1568 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
1569 ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n",
1570 (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i]));
1571 goto free_pbuf_and_return;
1574 /* match transaction ID against what we expected */
1575 if (ntohl(reply_msg->xid) != dhcp->xid) {
1576 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
1577 ("transaction id mismatch reply_msg->xid(%"X32_F")!=dhcp->xid(%"X32_F")\n",ntohl(reply_msg->xid),dhcp->xid));
1578 goto free_pbuf_and_return;
1580 /* option fields could be unfold? */
1581 if (dhcp_parse_reply(dhcp, p) != ERR_OK) {
1582 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
1583 ("problem unfolding DHCP message - too short on memory?\n"));
1584 goto free_pbuf_and_return;
1587 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n"));
1588 /* obtain pointer to DHCP message type */
1589 if (!dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE)) {
1590 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP_OPTION_MESSAGE_TYPE option not found\n"));
1591 goto free_pbuf_and_return;
1594 /* read DHCP message type */
1595 msg_type = (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE);
1596 /* message type is DHCP ACK? */
1597 if (msg_type == DHCP_ACK) {
1598 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_ACK received\n"));
1599 /* in requesting state? */
1600 if (dhcp->state == DHCP_REQUESTING) {
1601 dhcp_handle_ack(netif);
1602 #if DHCP_DOES_ARP_CHECK
1603 /* check if the acknowledged lease address is already in use */
1606 /* bind interface to the acknowledged lease address */
1610 /* already bound to the given lease address? */
1611 else if ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING)) {
1615 /* received a DHCP_NAK in appropriate state? */
1616 else if ((msg_type == DHCP_NAK) &&
1617 ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REQUESTING) ||
1618 (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING ))) {
1619 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_NAK received\n"));
1620 dhcp_handle_nak(netif);
1622 /* received a DHCP_OFFER in DHCP_SELECTING state? */
1623 else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_SELECTING)) {
1624 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_OFFER received in DHCP_SELECTING state\n"));
1625 dhcp->request_timeout = 0;
1626 /* remember offered lease */
1627 dhcp_handle_offer(netif);
1629 free_pbuf_and_return:
1630 dhcp->msg_in = NULL;
1635 * Create a DHCP request, fill in common headers
1637 * @param netif the netif under DHCP control
1638 * @param dhcp dhcp control struct
1639 * @param message_type message type of the request
1642 dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type)
1645 #ifndef DHCP_GLOBAL_XID
1646 /** default global transaction identifier starting value (easy to match
1647 * with a packet analyser). We simply increment for each new request.
1648 * Predefine DHCP_GLOBAL_XID to a better value or a function call to generate one
1649 * at runtime, any supporting function prototypes can be defined in DHCP_GLOBAL_XID_HEADER */
1650 #if DHCP_CREATE_RAND_XID && defined(LWIP_RAND)
1652 #else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1653 static u32_t xid = 0xABCD0000;
1654 #endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1656 if (!xid_initialised) {
1657 xid = DHCP_GLOBAL_XID;
1658 xid_initialised = !xid_initialised;
1661 LWIP_ERROR("dhcp_create_msg: netif != NULL", (netif != NULL), return ERR_ARG;);
1662 LWIP_ERROR("dhcp_create_msg: dhcp != NULL", (dhcp != NULL), return ERR_VAL;);
1663 LWIP_ASSERT("dhcp_create_msg: dhcp->p_out == NULL", dhcp->p_out == NULL);
1664 LWIP_ASSERT("dhcp_create_msg: dhcp->msg_out == NULL", dhcp->msg_out == NULL);
1665 dhcp->p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM);
1666 if (dhcp->p_out == NULL) {
1667 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
1668 ("dhcp_create_msg(): could not allocate pbuf\n"));
1671 LWIP_ASSERT("dhcp_create_msg: check that first pbuf can hold struct dhcp_msg",
1672 (dhcp->p_out->len >= sizeof(struct dhcp_msg)));
1674 /* reuse transaction identifier in retransmissions */
1675 if (dhcp->tries == 0) {
1676 #if DHCP_CREATE_RAND_XID && defined(LWIP_RAND)
1678 #else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1680 #endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1683 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE,
1684 ("transaction id xid(%"X32_F")\n", xid));
1686 dhcp->msg_out = (struct dhcp_msg *)dhcp->p_out->payload;
1688 dhcp->msg_out->op = DHCP_BOOTREQUEST;
1689 /* TODO: make link layer independent */
1690 dhcp->msg_out->htype = DHCP_HTYPE_ETH;
1691 dhcp->msg_out->hlen = netif->hwaddr_len;
1692 dhcp->msg_out->hops = 0;
1693 dhcp->msg_out->xid = htonl(dhcp->xid);
1694 dhcp->msg_out->secs = 0;
1695 /* we don't need the broadcast flag since we can receive unicast traffic
1696 before being fully configured! */
1697 dhcp->msg_out->flags = 0;
1698 ip_addr_set_zero(&dhcp->msg_out->ciaddr);
1699 /* set ciaddr to netif->ip_addr based on message_type and state */
1700 if ((message_type == DHCP_INFORM) || (message_type == DHCP_DECLINE) ||
1701 ((message_type == DHCP_REQUEST) && /* DHCP_BOUND not used for sending! */
1702 ((dhcp->state==DHCP_RENEWING) || dhcp->state==DHCP_REBINDING))) {
1703 ip_addr_copy(dhcp->msg_out->ciaddr, netif->ip_addr);
1705 ip_addr_set_zero(&dhcp->msg_out->yiaddr);
1706 ip_addr_set_zero(&dhcp->msg_out->siaddr);
1707 ip_addr_set_zero(&dhcp->msg_out->giaddr);
1708 for (i = 0; i < DHCP_CHADDR_LEN; i++) {
1709 /* copy netif hardware address, pad with zeroes */
1710 dhcp->msg_out->chaddr[i] = (i < netif->hwaddr_len && i < NETIF_MAX_HWADDR_LEN) ? netif->hwaddr[i] : 0/* pad byte*/;
1712 for (i = 0; i < DHCP_SNAME_LEN; i++) {
1713 dhcp->msg_out->sname[i] = 0;
1715 for (i = 0; i < DHCP_FILE_LEN; i++) {
1716 dhcp->msg_out->file[i] = 0;
1718 dhcp->msg_out->cookie = PP_HTONL(DHCP_MAGIC_COOKIE);
1719 dhcp->options_out_len = 0;
1720 /* fill options field with an incrementing array (for debugging purposes) */
1721 for (i = 0; i < DHCP_OPTIONS_LEN; i++) {
1722 dhcp->msg_out->options[i] = (u8_t)i; /* for debugging only, no matter if truncated */
1724 /* Add option MESSAGE_TYPE */
1725 dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
1726 dhcp_option_byte(dhcp, message_type);
1731 * Free previously allocated memory used to send a DHCP request.
1733 * @param dhcp the dhcp struct to free the request from
1736 dhcp_delete_msg(struct dhcp *dhcp)
1738 LWIP_ERROR("dhcp_delete_msg: dhcp != NULL", (dhcp != NULL), return;);
1739 LWIP_ASSERT("dhcp_delete_msg: dhcp->p_out != NULL", dhcp->p_out != NULL);
1740 LWIP_ASSERT("dhcp_delete_msg: dhcp->msg_out != NULL", dhcp->msg_out != NULL);
1741 if (dhcp->p_out != NULL) {
1742 pbuf_free(dhcp->p_out);
1745 dhcp->msg_out = NULL;
1749 * Add a DHCP message trailer
1751 * Adds the END option to the DHCP message, and if
1752 * necessary, up to three padding bytes.
1754 * @param dhcp DHCP state structure
1757 dhcp_option_trailer(struct dhcp *dhcp)
1759 LWIP_ERROR("dhcp_option_trailer: dhcp != NULL", (dhcp != NULL), return;);
1760 LWIP_ASSERT("dhcp_option_trailer: dhcp->msg_out != NULL\n", dhcp->msg_out != NULL);
1761 LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN);
1762 dhcp->msg_out->options[dhcp->options_out_len++] = DHCP_OPTION_END;
1763 /* packet is too small, or not 4 byte aligned? */
1764 while (((dhcp->options_out_len < DHCP_MIN_OPTIONS_LEN) || (dhcp->options_out_len & 3)) &&
1765 (dhcp->options_out_len < DHCP_OPTIONS_LEN)) {
1766 /* add a fill/padding byte */
1767 dhcp->msg_out->options[dhcp->options_out_len++] = 0;
1771 #endif /* LWIP_DHCP */