1 /**
2 * @file
3 * Dynamic Host Configuration Protocol client
4 *
5 * @defgroup dhcp4 DHCPv4
6 * @ingroup ip4
7 * DHCP (IPv4) related functions
8 * This is a DHCP client for the lwIP TCP/IP stack. It aims to conform
9 * with RFC 2131 and RFC 2132.
10 *
11 * @todo:
12 * - Support for interfaces other than Ethernet (SLIP, PPP, ...)
13 *
14 * Options:
15 * @ref DHCP_COARSE_TIMER_SECS (recommended 60 which is a minute)
16 * @ref DHCP_FINE_TIMER_MSECS (recommended 500 which equals TCP coarse timer)
17 *
18 * dhcp_start() starts a DHCP client instance which
19 * configures the interface by obtaining an IP address lease and maintaining it.
20 *
21 * Use dhcp_release() to end the lease and use dhcp_stop()
22 * to remove the DHCP client.
23 *
24 * @see LWIP_HOOK_DHCP_APPEND_OPTIONS
25 * @see LWIP_HOOK_DHCP_PARSE_OPTION
26 *
27 * @see netifapi_dhcp4
28 */
29
30 /*
31 * Copyright (c) 2001-2004 Leon Woestenberg <leon.woestenberg@gmx.net>
32 * Copyright (c) 2001-2004 Axon Digital Design B.V., The Netherlands.
33 * All rights reserved.
34 *
35 * Redistribution and use in source and binary forms, with or without modification,
36 * are permitted provided that the following conditions are met:
37 *
38 * 1. Redistributions of source code must retain the above copyright notice,
39 * this list of conditions and the following disclaimer.
40 * 2. Redistributions in binary form must reproduce the above copyright notice,
41 * this list of conditions and the following disclaimer in the documentation
42 * and/or other materials provided with the distribution.
43 * 3. The name of the author may not be used to endorse or promote products
44 * derived from this software without specific prior written permission.
45 *
46 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
47 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
48 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
49 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
50 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
51 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
52 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
53 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
54 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
55 * OF SUCH DAMAGE.
56 *
57 * This file is part of the lwIP TCP/IP stack.
58 * The Swedish Institute of Computer Science and Adam Dunkels
59 * are specifically granted permission to redistribute this
60 * source code.
61 *
62 * Author: Leon Woestenberg <leon.woestenberg@gmx.net>
63 *
64 */
65
66 #include "lwip/opt.h"
67
68 #if LWIP_IPV4 && LWIP_DHCP /* don't build if not configured for use in lwipopts.h */
69
70 #include "lwip/stats.h"
71 #include "lwip/mem.h"
72 #include "lwip/udp.h"
73 #include "lwip/ip_addr.h"
74 #include "lwip/netif.h"
75 #include "lwip/def.h"
76 #include "lwip/dhcp.h"
77 #include "lwip/autoip.h"
78 #include "lwip/dns.h"
79 #include "lwip/etharp.h"
80 #include "lwip/prot/dhcp.h"
81 #include "lwip/prot/iana.h"
82
83 #include <string.h>
84
85 #ifdef LWIP_HOOK_FILENAME
86 #include LWIP_HOOK_FILENAME
87 #endif
88 #ifndef LWIP_HOOK_DHCP_APPEND_OPTIONS
89 #define LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, state, msg, msg_type, options_len_ptr)
90 #endif
91 #ifndef LWIP_HOOK_DHCP_PARSE_OPTION
92 #define LWIP_HOOK_DHCP_PARSE_OPTION(netif, dhcp, state, msg, msg_type, option, len, pbuf, offset) do { LWIP_UNUSED_ARG(msg); } while(0)
93 #endif
94
95 /** DHCP_CREATE_RAND_XID: if this is set to 1, the xid is created using
96 * LWIP_RAND() (this overrides DHCP_GLOBAL_XID)
97 */
98 #ifndef DHCP_CREATE_RAND_XID
99 #define DHCP_CREATE_RAND_XID 1
100 #endif
101
102 /** Default for DHCP_GLOBAL_XID is 0xABCD0000
103 * This can be changed by defining DHCP_GLOBAL_XID and DHCP_GLOBAL_XID_HEADER, e.g.
104 * \#define DHCP_GLOBAL_XID_HEADER "stdlib.h"
105 * \#define DHCP_GLOBAL_XID rand()
106 */
107 #ifdef DHCP_GLOBAL_XID_HEADER
108 #include DHCP_GLOBAL_XID_HEADER /* include optional starting XID generation prototypes */
109 #endif
110
111 /** DHCP_OPTION_MAX_MSG_SIZE is set to the MTU
112 * MTU is checked to be big enough in dhcp_start */
113 #define DHCP_MAX_MSG_LEN(netif) (netif->mtu)
114 #define DHCP_MAX_MSG_LEN_MIN_REQUIRED 576
115 /** Minimum length for reply before packet is parsed */
116 #define DHCP_MIN_REPLY_LEN 44
117
118 #define REBOOT_TRIES 2
119 #if 0 /* The following codes are moved to dhcp.h for fixing it's todo, kept here just for notice */
120 #if LWIP_DNS && LWIP_DHCP_MAX_DNS_SERVERS
121 #if DNS_MAX_SERVERS > LWIP_DHCP_MAX_DNS_SERVERS
122 #define LWIP_DHCP_PROVIDE_DNS_SERVERS LWIP_DHCP_MAX_DNS_SERVERS
123 #else
124 #define LWIP_DHCP_PROVIDE_DNS_SERVERS DNS_MAX_SERVERS
125 #endif
126 #else
127 #define LWIP_DHCP_PROVIDE_DNS_SERVERS 0
128 #endif
129
130 /** Option handling: options are parsed in dhcp_parse_reply
131 * and saved in an array where other functions can load them from.
132 * This might be moved into the struct dhcp (not necessarily since
133 * lwIP is single-threaded and the array is only used while in recv
134 * callback). */
135 enum dhcp_option_idx {
136 DHCP_OPTION_IDX_OVERLOAD = 0,
137 DHCP_OPTION_IDX_MSG_TYPE,
138 DHCP_OPTION_IDX_SERVER_ID,
139 DHCP_OPTION_IDX_LEASE_TIME,
140 DHCP_OPTION_IDX_T1,
141 DHCP_OPTION_IDX_T2,
142 DHCP_OPTION_IDX_SUBNET_MASK,
143 DHCP_OPTION_IDX_ROUTER,
144 #if LWIP_DHCP_PROVIDE_DNS_SERVERS
145 DHCP_OPTION_IDX_DNS_SERVER,
146 DHCP_OPTION_IDX_DNS_SERVER_LAST = DHCP_OPTION_IDX_DNS_SERVER + LWIP_DHCP_PROVIDE_DNS_SERVERS - 1,
147 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */
148 #if LWIP_DHCP_GET_NTP_SRV
149 DHCP_OPTION_IDX_NTP_SERVER,
150 DHCP_OPTION_IDX_NTP_SERVER_LAST = DHCP_OPTION_IDX_NTP_SERVER + LWIP_DHCP_MAX_NTP_SERVERS - 1,
151 #endif /* LWIP_DHCP_GET_NTP_SRV */
152 DHCP_OPTION_IDX_MAX
153 };
154
155 /** Holds the decoded option values, only valid while in dhcp_recv.
156 @todo: move this into struct dhcp? */
157 u32_t dhcp_rx_options_val[DHCP_OPTION_IDX_MAX];
158 /** Holds a flag which option was received and is contained in dhcp_rx_options_val,
159 only valid while in dhcp_recv.
160 @todo: move this into struct dhcp? */
161 u8_t dhcp_rx_options_given[DHCP_OPTION_IDX_MAX];
162 #endif
163
164 #ifndef LWIP_DHCP_INPUT_ERROR
165 #define LWIP_DHCP_INPUT_ERROR(message, expression, handler) do { if (!(expression)) { \
166 handler;} } while(0)
167 #endif
168
169 static u8_t dhcp_discover_request_options[] = {
170 DHCP_OPTION_SUBNET_MASK,
171 DHCP_OPTION_ROUTER,
172 DHCP_OPTION_BROADCAST
173 #if LWIP_DHCP_PROVIDE_DNS_SERVERS
174 , DHCP_OPTION_DNS_SERVER
175 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */
176 #if LWIP_DHCP_GET_NTP_SRV
177 , DHCP_OPTION_NTP
178 #endif /* LWIP_DHCP_GET_NTP_SRV */
179 };
180
181 #ifdef DHCP_GLOBAL_XID
182 static u32_t xid;
183 static u8_t xid_initialised;
184 #endif /* DHCP_GLOBAL_XID */
185
186 #define dhcp_option_given(dhcp, idx) ((dhcp)->rx_options_given[idx] != 0)
187 #define dhcp_got_option(dhcp, idx) ((dhcp)->rx_options_given[idx] = 1)
188 #define dhcp_clear_option(dhcp, idx) ((dhcp)->rx_options_given[idx] = 0)
189 #define dhcp_clear_all_options(dhcp) (memset((dhcp)->rx_options_given, 0, sizeof((dhcp)->rx_options_given)))
190 #define dhcp_get_option_value(dhcp, idx) ((dhcp)->rx_options_val[idx])
191 #define dhcp_set_option_value(dhcp, idx, val) ((dhcp)->rx_options_val[idx] = (val))
192
193 static struct udp_pcb *dhcp_pcb;
194 static u8_t dhcp_pcb_refcount;
195
196 /* DHCP client state machine functions */
197 static err_t dhcp_discover(struct netif *netif);
198 static err_t dhcp_select(struct netif *netif);
199 static void dhcp_bind(struct netif *netif);
200 #if DHCP_DOES_ARP_CHECK
201 static err_t dhcp_decline(struct netif *netif);
202 #endif /* DHCP_DOES_ARP_CHECK */
203 static err_t dhcp_rebind(struct netif *netif);
204 static err_t dhcp_reboot(struct netif *netif);
205 static void dhcp_set_state(struct dhcp *dhcp, u8_t new_state);
206
207 /* receive, unfold, parse and free incoming messages */
208 static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port);
209
210 /* set the DHCP timers */
211 static void dhcp_timeout(struct netif *netif);
212 static void dhcp_t1_timeout(struct netif *netif);
213 static void dhcp_t2_timeout(struct netif *netif);
214
215 /* build outgoing messages */
216 /* create a DHCP message, fill in common headers */
217 static struct pbuf *dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type, u16_t *options_out_len);
218 /* add a DHCP option (type, then length in bytes) */
219 static u16_t dhcp_option(u16_t options_out_len, u8_t *options, u8_t option_type, u8_t option_len);
220 /* add option values */
221 static u16_t dhcp_option_byte(u16_t options_out_len, u8_t *options, u8_t value);
222 static u16_t dhcp_option_short(u16_t options_out_len, u8_t *options, u16_t value);
223 static u16_t dhcp_option_long(u16_t options_out_len, u8_t *options, u32_t value);
224 #if LWIP_NETIF_HOSTNAME
225 static u16_t dhcp_option_hostname(u16_t options_out_len, u8_t *options, struct netif *netif);
226 #endif /* LWIP_NETIF_HOSTNAME */
227 /* always add the DHCP options trailer to end and pad */
228 static void dhcp_option_trailer(u16_t options_out_len, u8_t *options, struct pbuf *p_out);
229
230 /** Ensure DHCP PCB is allocated and bound */
231 static err_t
dhcp_inc_pcb_refcount(void)232 dhcp_inc_pcb_refcount(void)
233 {
234 if (dhcp_pcb_refcount == 0) {
235 LWIP_ASSERT("dhcp_inc_pcb_refcount(): memory leak", dhcp_pcb == NULL);
236
237 /* allocate UDP PCB */
238 dhcp_pcb = udp_new();
239
240 if (dhcp_pcb == NULL) {
241 return ERR_MEM;
242 }
243
244 ip_set_option(dhcp_pcb, SOF_BROADCAST);
245
246 /* set up local and remote port for the pcb -> listen on all interfaces on all src/dest IPs */
247 udp_bind(dhcp_pcb, IP4_ADDR_ANY, LWIP_IANA_PORT_DHCP_CLIENT);
248 udp_connect(dhcp_pcb, IP4_ADDR_ANY, LWIP_IANA_PORT_DHCP_SERVER);
249 udp_recv(dhcp_pcb, dhcp_recv, NULL);
250 }
251
252 dhcp_pcb_refcount++;
253
254 return ERR_OK;
255 }
256
257 /** Free DHCP PCB if the last netif stops using it */
258 static void
dhcp_dec_pcb_refcount(void)259 dhcp_dec_pcb_refcount(void)
260 {
261 LWIP_ASSERT("dhcp_pcb_refcount(): refcount error", (dhcp_pcb_refcount > 0));
262 dhcp_pcb_refcount--;
263
264 if (dhcp_pcb_refcount == 0) {
265 udp_remove(dhcp_pcb);
266 dhcp_pcb = NULL;
267 }
268 }
269
270 /**
271 * Back-off the DHCP client (because of a received NAK response).
272 *
273 * Back-off the DHCP client because of a received NAK. Receiving a
274 * NAK means the client asked for something non-sensible, for
275 * example when it tries to renew a lease obtained on another network.
276 *
277 * We clear any existing set IP address and restart DHCP negotiation
278 * afresh (as per RFC2131 3.2.3).
279 *
280 * @param netif the netif under DHCP control
281 */
282 static void
dhcp_handle_nak(struct netif * netif)283 dhcp_handle_nak(struct netif *netif)
284 {
285 struct dhcp *dhcp = netif_dhcp_data(netif);
286
287 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_nak(netif=%p) %c%c%"U16_F"\n",
288 (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num));
289 /* Change to a defined state - set this before assigning the address
290 to ensure the callback can use dhcp_supplied_address() */
291 dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF);
292 /* remove IP address from interface (must no longer be used, as per RFC2131) */
293 netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4);
294 /* We can immediately restart discovery */
295 dhcp_discover(netif);
296 }
297
298 #if DHCP_DOES_ARP_CHECK
299 /**
300 * Checks if the offered IP address is already in use.
301 *
302 * It does so by sending an ARP request for the offered address and
303 * entering CHECKING state. If no ARP reply is received within a small
304 * interval, the address is assumed to be free for use by us.
305 *
306 * @param netif the netif under DHCP control
307 */
308 static void
dhcp_check(struct netif * netif)309 dhcp_check(struct netif *netif)
310 {
311 struct dhcp *dhcp = netif_dhcp_data(netif);
312 err_t result;
313 u16_t msecs;
314 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_check(netif=%p) %c%c\n", (void *)netif, (s16_t)netif->name[0],
315 (s16_t)netif->name[1]));
316 dhcp_set_state(dhcp, DHCP_STATE_CHECKING);
317 /* create an ARP query for the offered IP address, expecting that no host
318 responds, as the IP address should not be in use. */
319 result = etharp_query(netif, &dhcp->offered_ip_addr, NULL);
320 if (result != ERR_OK) {
321 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_check: could not perform ARP query\n"));
322 }
323 if (dhcp->tries < 255) {
324 dhcp->tries++;
325 }
326 msecs = 500;
327 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
328 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_check(): set request timeout %"U16_F" msecs\n", msecs));
329 }
330 #endif /* DHCP_DOES_ARP_CHECK */
331
332 /**
333 * Remember the configuration offered by a DHCP server.
334 *
335 * @param netif the netif under DHCP control
336 */
337 static void
dhcp_handle_offer(struct netif * netif,struct dhcp_msg * msg_in)338 dhcp_handle_offer(struct netif *netif, struct dhcp_msg *msg_in)
339 {
340 struct dhcp *dhcp = netif_dhcp_data(netif);
341
342 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_offer(netif=%p) %c%c%"U16_F"\n",
343 (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num));
344 /* obtain the server address */
345 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SERVER_ID)) {
346 dhcp->request_timeout = 0; /* stop timer */
347
348 ip_addr_set_ip4_u32(&dhcp->server_ip_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SERVER_ID)));
349 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): server 0x%08"X32_F"\n",
350 ip4_addr_get_u32(ip_2_ip4(&dhcp->server_ip_addr))));
351 /* remember offered address */
352 ip4_addr_copy(dhcp->offered_ip_addr, msg_in->yiaddr);
353 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): offer for 0x%08"X32_F"\n",
354 ip4_addr_get_u32(&dhcp->offered_ip_addr)));
355
356 dhcp_select(netif);
357 } else {
358 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
359 ("dhcp_handle_offer(netif=%p) did not get server ID!\n", (void *)netif));
360 }
361 }
362
363 /**
364 * Select a DHCP server offer out of all offers.
365 *
366 * Simply select the first offer received.
367 *
368 * @param netif the netif under DHCP control
369 * @return lwIP specific error (see error.h)
370 */
371 static err_t
dhcp_select(struct netif * netif)372 dhcp_select(struct netif *netif)
373 {
374 struct dhcp *dhcp;
375 err_t result;
376 u16_t msecs;
377 u8_t i;
378 struct pbuf *p_out;
379 u16_t options_out_len;
380
381 LWIP_ERROR("dhcp_select: netif != NULL", (netif != NULL), return ERR_ARG;);
382 dhcp = netif_dhcp_data(netif);
383 LWIP_ERROR("dhcp_select: dhcp != NULL", (dhcp != NULL), return ERR_VAL;);
384
385 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));
386 dhcp_set_state(dhcp, DHCP_STATE_REQUESTING);
387
388 /* create and initialize the DHCP message header */
389 p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len);
390 if (p_out != NULL) {
391 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
392 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
393 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
394
395 /* MUST request the offered IP address */
396 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_REQUESTED_IP, 4);
397 options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
398
399 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_SERVER_ID, 4);
400 options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(ip_2_ip4(&dhcp->server_ip_addr))));
401
402 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
403 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
404 options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);
405 }
406
407 #if LWIP_NETIF_HOSTNAME
408 options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif);
409 #endif /* LWIP_NETIF_HOSTNAME */
410
411 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_REQUESTING, msg_out, DHCP_REQUEST, &options_out_len);
412 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
413
414 /* send broadcast to any DHCP server */
415 result = udp_sendto_if_src(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif, IP4_ADDR_ANY);
416 pbuf_free(p_out);
417 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_select: REQUESTING\n"));
418 } else {
419 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_select: could not allocate DHCP request\n"));
420 result = ERR_MEM;
421 }
422 if (dhcp->tries < 255) {
423 dhcp->tries++;
424 }
425 msecs = (u16_t)((dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000);
426 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
427 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_select(): set request timeout %"U16_F" msecs\n", msecs));
428 return result;
429 }
430
431 /**
432 * The DHCP timer that checks for lease renewal/rebind timeouts.
433 * Must be called once a minute (see @ref DHCP_COARSE_TIMER_SECS).
434 */
435 void
dhcp_coarse_tmr(void)436 dhcp_coarse_tmr(void)
437 {
438 struct netif *netif;
439 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n"));
440 /* iterate through all network interfaces */
441 NETIF_FOREACH(netif) {
442 /* only act on DHCP configured interfaces */
443 struct dhcp *dhcp = netif_dhcp_data(netif);
444 if ((dhcp != NULL) && (dhcp->state != DHCP_STATE_OFF)) {
445 /* compare lease time to expire timeout */
446 if (dhcp->t0_timeout && (++dhcp->lease_used == dhcp->t0_timeout)) {
447 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t0 timeout\n"));
448 /* this clients' lease time has expired */
449 dhcp_release_and_stop(netif);
450 dhcp_start(netif);
451 /* timer is active (non zero), and triggers (zeroes) now? */
452 } else if (dhcp->t2_rebind_time && (dhcp->t2_rebind_time-- == 1)) {
453 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t2 timeout\n"));
454 /* this clients' rebind timeout triggered */
455 dhcp_t2_timeout(netif);
456 /* timer is active (non zero), and triggers (zeroes) now */
457 } else if (dhcp->t1_renew_time && (dhcp->t1_renew_time-- == 1)) {
458 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t1 timeout\n"));
459 /* this clients' renewal timeout triggered */
460 dhcp_t1_timeout(netif);
461 }
462 }
463 }
464 }
465
466 /**
467 * DHCP transaction timeout handling (this function must be called every 500ms,
468 * see @ref DHCP_FINE_TIMER_MSECS).
469 *
470 * A DHCP server is expected to respond within a short period of time.
471 * This timer checks whether an outstanding DHCP request is timed out.
472 */
473 void
dhcp_fine_tmr(void)474 dhcp_fine_tmr(void)
475 {
476 struct netif *netif;
477 /* loop through netif's */
478 NETIF_FOREACH(netif) {
479 struct dhcp *dhcp = netif_dhcp_data(netif);
480 /* only act on DHCP configured interfaces */
481 if (dhcp != NULL) {
482 /* timer is active (non zero), and is about to trigger now */
483 if (dhcp->request_timeout > 1) {
484 dhcp->request_timeout--;
485 } else if (dhcp->request_timeout == 1) {
486 dhcp->request_timeout--;
487 /* { dhcp->request_timeout == 0 } */
488 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_fine_tmr(): request timeout\n"));
489 /* this client's request timeout triggered */
490 dhcp_timeout(netif);
491 }
492 }
493 }
494 }
495
496 /**
497 * A DHCP negotiation transaction, or ARP request, has timed out.
498 *
499 * The timer that was started with the DHCP or ARP request has
500 * timed out, indicating no response was received in time.
501 *
502 * @param netif the netif under DHCP control
503 */
504 static void
dhcp_timeout(struct netif * netif)505 dhcp_timeout(struct netif *netif)
506 {
507 struct dhcp *dhcp = netif_dhcp_data(netif);
508
509 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout()\n"));
510 /* back-off period has passed, or server selection timed out */
511 if ((dhcp->state == DHCP_STATE_BACKING_OFF) || (dhcp->state == DHCP_STATE_SELECTING)) {
512 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout(): restarting discovery\n"));
513 dhcp_discover(netif);
514 /* receiving the requested lease timed out */
515 } else if (dhcp->state == DHCP_STATE_REQUESTING) {
516 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, DHCP request timed out\n"));
517 if (dhcp->tries <= 5) {
518 dhcp_select(netif);
519 } else {
520 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, releasing, restarting\n"));
521 dhcp_release_and_stop(netif);
522 dhcp_start(netif);
523 }
524 #if DHCP_DOES_ARP_CHECK
525 /* received no ARP reply for the offered address (which is good) */
526 } else if (dhcp->state == DHCP_STATE_CHECKING) {
527 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): CHECKING, ARP request timed out\n"));
528 if (dhcp->tries <= 1) {
529 dhcp_check(netif);
530 /* no ARP replies on the offered address,
531 looks like the IP address is indeed free */
532 } else {
533 /* bind the interface to the offered address */
534 dhcp_bind(netif);
535 }
536 #endif /* DHCP_DOES_ARP_CHECK */
537 } else if (dhcp->state == DHCP_STATE_REBOOTING) {
538 if (dhcp->tries < REBOOT_TRIES) {
539 dhcp_reboot(netif);
540 } else {
541 dhcp_discover(netif);
542 }
543 }
544 }
545
546 /**
547 * The renewal period has timed out.
548 *
549 * @param netif the netif under DHCP control
550 */
551 static void
dhcp_t1_timeout(struct netif * netif)552 dhcp_t1_timeout(struct netif *netif)
553 {
554 struct dhcp *dhcp = netif_dhcp_data(netif);
555
556 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_t1_timeout()\n"));
557 if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_BOUND) ||
558 (dhcp->state == DHCP_STATE_RENEWING)) {
559 /* just retry to renew - note that the rebind timer (t2) will
560 * eventually time-out if renew tries fail. */
561 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
562 ("dhcp_t1_timeout(): must renew\n"));
563 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state
564 DHCP_STATE_RENEWING, not DHCP_STATE_BOUND */
565 dhcp_renew(netif);
566 /* Calculate next timeout */
567 if (((dhcp->t2_timeout - dhcp->lease_used) / 2) >= ((60 + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS)) {
568 dhcp->t1_renew_time = (u16_t)((dhcp->t2_timeout - dhcp->lease_used) / 2);
569 }
570 }
571 }
572
573 /**
574 * The rebind period has timed out.
575 *
576 * @param netif the netif under DHCP control
577 */
578 static void
dhcp_t2_timeout(struct netif * netif)579 dhcp_t2_timeout(struct netif *netif)
580 {
581 struct dhcp *dhcp = netif_dhcp_data(netif);
582
583 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t2_timeout()\n"));
584 if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_BOUND) ||
585 (dhcp->state == DHCP_STATE_RENEWING) || (dhcp->state == DHCP_STATE_REBINDING)) {
586 /* just retry to rebind */
587 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
588 ("dhcp_t2_timeout(): must rebind\n"));
589 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state
590 DHCP_STATE_REBINDING, not DHCP_STATE_BOUND */
591 dhcp_rebind(netif);
592 /* Calculate next timeout */
593 if (((dhcp->t0_timeout - dhcp->lease_used) / 2) >= ((60 + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS)) {
594 dhcp->t2_rebind_time = (u16_t)((dhcp->t0_timeout - dhcp->lease_used) / 2);
595 }
596 }
597 }
598
599 /**
600 * Handle a DHCP ACK packet
601 *
602 * @param netif the netif under DHCP control
603 */
604 static void
dhcp_handle_ack(struct netif * netif,struct dhcp_msg * msg_in)605 dhcp_handle_ack(struct netif *netif, struct dhcp_msg *msg_in)
606 {
607 struct dhcp *dhcp = netif_dhcp_data(netif);
608
609 #if LWIP_DHCP_PROVIDE_DNS_SERVERS || LWIP_DHCP_GET_NTP_SRV
610 u8_t n;
611 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS || LWIP_DHCP_GET_NTP_SRV */
612 #if LWIP_DHCP_GET_NTP_SRV
613 ip4_addr_t ntp_server_addrs[LWIP_DHCP_MAX_NTP_SERVERS];
614 #endif
615
616 /* clear options we might not get from the ACK */
617 ip4_addr_set_zero(&dhcp->offered_sn_mask);
618 ip4_addr_set_zero(&dhcp->offered_gw_addr);
619 #if LWIP_DHCP_BOOTP_FILE
620 ip4_addr_set_zero(&dhcp->offered_si_addr);
621 #endif /* LWIP_DHCP_BOOTP_FILE */
622
623 /* lease time given? */
624 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_LEASE_TIME)) {
625 /* remember offered lease time */
626 dhcp->offered_t0_lease = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_LEASE_TIME);
627 }
628 /* renewal period given? */
629 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T1)) {
630 /* remember given renewal period */
631 dhcp->offered_t1_renew = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T1);
632 } else {
633 /* calculate safe periods for renewal */
634 dhcp->offered_t1_renew = dhcp->offered_t0_lease / 2;
635 }
636
637 /* renewal period given? */
638 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T2)) {
639 /* remember given rebind period */
640 dhcp->offered_t2_rebind = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T2);
641 } else {
642 /* calculate safe periods for rebinding (offered_t0_lease * 0.875 -> 87.5%)*/
643 dhcp->offered_t2_rebind = (dhcp->offered_t0_lease * 7U) / 8U;
644 }
645
646 /* (y)our internet address */
647 ip4_addr_copy(dhcp->offered_ip_addr, msg_in->yiaddr);
648
649 #if LWIP_DHCP_BOOTP_FILE
650 /* copy boot server address,
651 boot file name copied in dhcp_parse_reply if not overloaded */
652 ip4_addr_copy(dhcp->offered_si_addr, msg_in->siaddr);
653 #endif /* LWIP_DHCP_BOOTP_FILE */
654
655 /* subnet mask given? */
656 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)) {
657 /* remember given subnet mask */
658 ip4_addr_set_u32(&dhcp->offered_sn_mask, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)));
659 dhcp->subnet_mask_given = 1;
660 } else {
661 dhcp->subnet_mask_given = 0;
662 }
663
664 /* gateway router */
665 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_ROUTER)) {
666 ip4_addr_set_u32(&dhcp->offered_gw_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_ROUTER)));
667 }
668
669 #if LWIP_DHCP_GET_NTP_SRV
670 /* NTP servers */
671 for (n = 0; (n < LWIP_DHCP_MAX_NTP_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_NTP_SERVER + n); n++) {
672 ip4_addr_set_u32(&ntp_server_addrs[n], lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_NTP_SERVER + n)));
673 }
674 dhcp_set_ntp_servers(n, ntp_server_addrs);
675 #endif /* LWIP_DHCP_GET_NTP_SRV */
676
677 #if LWIP_DHCP_PROVIDE_DNS_SERVERS
678 /* DNS servers */
679 for (n = 0; (n < LWIP_DHCP_PROVIDE_DNS_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n); n++) {
680 ip_addr_t dns_addr;
681 ip_addr_set_ip4_u32_val(dns_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n)));
682 dns_setserver(n, &dns_addr);
683 }
684 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */
685 }
686
687 /**
688 * @ingroup dhcp4
689 * Set a statically allocated struct dhcp to work with.
690 * Using this prevents dhcp_start to allocate it using mem_malloc.
691 *
692 * @param netif the netif for which to set the struct dhcp
693 * @param dhcp (uninitialised) dhcp struct allocated by the application
694 */
695 void
dhcp_set_struct(struct netif * netif,struct dhcp * dhcp)696 dhcp_set_struct(struct netif *netif, struct dhcp *dhcp)
697 {
698 LWIP_ASSERT_CORE_LOCKED();
699 LWIP_ASSERT("netif != NULL", netif != NULL);
700 LWIP_ASSERT("dhcp != NULL", dhcp != NULL);
701 LWIP_ASSERT("netif already has a struct dhcp set", netif_dhcp_data(netif) == NULL);
702
703 /* clear data structure */
704 memset(dhcp, 0, sizeof(struct dhcp));
705 /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */
706 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp);
707 }
708
709 /**
710 * @ingroup dhcp4
711 * Removes a struct dhcp from a netif.
712 *
713 * ATTENTION: Only use this when not using dhcp_set_struct() to allocate the
714 * struct dhcp since the memory is passed back to the heap.
715 *
716 * @param netif the netif from which to remove the struct dhcp
717 */
dhcp_cleanup(struct netif * netif)718 void dhcp_cleanup(struct netif *netif)
719 {
720 LWIP_ASSERT_CORE_LOCKED();
721 LWIP_ASSERT("netif != NULL", netif != NULL);
722
723 if (netif_dhcp_data(netif) != NULL) {
724 mem_free(netif_dhcp_data(netif));
725 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, NULL);
726 }
727 }
728
729 /**
730 * @ingroup dhcp4
731 * Start DHCP negotiation for a network interface.
732 *
733 * If no DHCP client instance was attached to this interface,
734 * a new client is created first. If a DHCP client instance
735 * was already present, it restarts negotiation.
736 *
737 * @param netif The lwIP network interface
738 * @return lwIP error code
739 * - ERR_OK - No error
740 * - ERR_MEM - Out of memory
741 */
742 err_t
dhcp_start(struct netif * netif)743 dhcp_start(struct netif *netif)
744 {
745 struct dhcp *dhcp;
746 err_t result;
747
748 LWIP_ASSERT_CORE_LOCKED();
749 LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;);
750 LWIP_ERROR("netif is not up, old style port?", netif_is_up(netif), return ERR_ARG;);
751 dhcp = netif_dhcp_data(netif);
752 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));
753
754 /* check MTU of the netif */
755 if (netif->mtu < DHCP_MAX_MSG_LEN_MIN_REQUIRED) {
756 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): Cannot use this netif with DHCP: MTU is too small\n"));
757 return ERR_MEM;
758 }
759
760 /* no DHCP client attached yet? */
761 if (dhcp == NULL) {
762 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): mallocing new DHCP client\n"));
763 dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp));
764 if (dhcp == NULL) {
765 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n"));
766 return ERR_MEM;
767 }
768
769 /* store this dhcp client in the netif */
770 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp);
771 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): allocated dhcp"));
772 /* already has DHCP client attached */
773 } else {
774 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(): restarting DHCP configuration\n"));
775
776 if (dhcp->pcb_allocated != 0) {
777 dhcp_dec_pcb_refcount(); /* free DHCP PCB if not needed any more */
778 }
779 /* dhcp is cleared below, no need to reset flag*/
780 }
781
782 /* clear data structure */
783 memset(dhcp, 0, sizeof(struct dhcp));
784 /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */
785
786 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n"));
787
788 if (dhcp_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP PCB is allocated */
789 return ERR_MEM;
790 }
791 dhcp->pcb_allocated = 1;
792
793 if (!netif_is_link_up(netif)) {
794 /* set state INIT and wait for dhcp_network_changed() to call dhcp_discover() */
795 dhcp_set_state(dhcp, DHCP_STATE_INIT);
796 return ERR_OK;
797 }
798
799 /* (re)start the DHCP negotiation */
800 result = dhcp_discover(netif);
801 if (result != ERR_OK) {
802 /* free resources allocated above */
803 dhcp_release_and_stop(netif);
804 return ERR_MEM;
805 }
806 return result;
807 }
808
809 /**
810 * @ingroup dhcp4
811 * Inform a DHCP server of our manual configuration.
812 *
813 * This informs DHCP servers of our fixed IP address configuration
814 * by sending an INFORM message. It does not involve DHCP address
815 * configuration, it is just here to be nice to the network.
816 *
817 * @param netif The lwIP network interface
818 */
819 void
dhcp_inform(struct netif * netif)820 dhcp_inform(struct netif *netif)
821 {
822 struct dhcp dhcp;
823 struct pbuf *p_out;
824 u16_t options_out_len;
825
826 LWIP_ASSERT_CORE_LOCKED();
827 LWIP_ERROR("netif != NULL", (netif != NULL), return;);
828
829 if (dhcp_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP PCB is allocated */
830 return;
831 }
832
833 memset(&dhcp, 0, sizeof(struct dhcp));
834 dhcp_set_state(&dhcp, DHCP_STATE_INFORMING);
835
836 /* create and initialize the DHCP message header */
837 p_out = dhcp_create_msg(netif, &dhcp, DHCP_INFORM, &options_out_len);
838 if (p_out != NULL) {
839 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
840 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
841 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
842
843 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, &dhcp, DHCP_STATE_INFORMING, msg_out, DHCP_INFORM, &options_out_len);
844 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
845
846 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n"));
847
848 udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif);
849
850 pbuf_free(p_out);
851 } else {
852 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform: could not allocate DHCP request\n"));
853 }
854
855 dhcp_dec_pcb_refcount(); /* delete DHCP PCB if not needed any more */
856 }
857
858 /** Handle a possible change in the network configuration.
859 *
860 * This enters the REBOOTING state to verify that the currently bound
861 * address is still valid.
862 */
863 void
dhcp_network_changed(struct netif * netif)864 dhcp_network_changed(struct netif *netif)
865 {
866 struct dhcp *dhcp = netif_dhcp_data(netif);
867
868 if (!dhcp) {
869 return;
870 }
871 switch (dhcp->state) {
872 case DHCP_STATE_REBINDING:
873 case DHCP_STATE_RENEWING:
874 case DHCP_STATE_BOUND:
875 case DHCP_STATE_REBOOTING:
876 dhcp->tries = 0;
877 dhcp_reboot(netif);
878 break;
879 case DHCP_STATE_OFF:
880 /* stay off */
881 break;
882 default:
883 LWIP_ASSERT("invalid dhcp->state", dhcp->state <= DHCP_STATE_BACKING_OFF);
884 /* INIT/REQUESTING/CHECKING/BACKING_OFF restart with new 'rid' because the
885 state changes, SELECTING: continue with current 'rid' as we stay in the
886 same state */
887 #if LWIP_DHCP_AUTOIP_COOP
888 if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
889 autoip_stop(netif);
890 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
891 }
892 #endif /* LWIP_DHCP_AUTOIP_COOP */
893 /* ensure we start with short timeouts, even if already discovering */
894 dhcp->tries = 0;
895 dhcp_discover(netif);
896 break;
897 }
898 }
899
900 #if DHCP_DOES_ARP_CHECK
901 /**
902 * Match an ARP reply with the offered IP address:
903 * check whether the offered IP address is not in use using ARP
904 *
905 * @param netif the network interface on which the reply was received
906 * @param addr The IP address we received a reply from
907 */
908 void
dhcp_arp_reply(struct netif * netif,const ip4_addr_t * addr)909 dhcp_arp_reply(struct netif *netif, const ip4_addr_t *addr)
910 {
911 struct dhcp *dhcp;
912
913 LWIP_ERROR("netif != NULL", (netif != NULL), return;);
914 dhcp = netif_dhcp_data(netif);
915 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_arp_reply()\n"));
916 /* is a DHCP client doing an ARP check? */
917 if ((dhcp != NULL) && (dhcp->state == DHCP_STATE_CHECKING)) {
918 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_arp_reply(): CHECKING, arp reply for 0x%08"X32_F"\n",
919 ip4_addr_get_u32(addr)));
920 /* did a host respond with the address we
921 were offered by the DHCP server? */
922 if (ip4_addr_cmp(addr, &dhcp->offered_ip_addr)) {
923 /* we will not accept the offered address */
924 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
925 ("dhcp_arp_reply(): arp reply matched with offered address, declining\n"));
926 dhcp_decline(netif);
927 }
928 }
929 }
930
931 /**
932 * Decline an offered lease.
933 *
934 * Tell the DHCP server we do not accept the offered address.
935 * One reason to decline the lease is when we find out the address
936 * is already in use by another host (through ARP).
937 *
938 * @param netif the netif under DHCP control
939 */
940 static err_t
dhcp_decline(struct netif * netif)941 dhcp_decline(struct netif *netif)
942 {
943 struct dhcp *dhcp = netif_dhcp_data(netif);
944 err_t result;
945 u16_t msecs;
946 struct pbuf *p_out;
947 u16_t options_out_len;
948
949 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline()\n"));
950 dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF);
951 /* create and initialize the DHCP message header */
952 p_out = dhcp_create_msg(netif, dhcp, DHCP_DECLINE, &options_out_len);
953 if (p_out != NULL) {
954 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
955 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_REQUESTED_IP, 4);
956 options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
957
958 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_BACKING_OFF, msg_out, DHCP_DECLINE, &options_out_len);
959 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
960
961 /* per section 4.4.4, broadcast DECLINE messages */
962 result = udp_sendto_if_src(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif, IP4_ADDR_ANY);
963 pbuf_free(p_out);
964 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_decline: BACKING OFF\n"));
965 } else {
966 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
967 ("dhcp_decline: could not allocate DHCP request\n"));
968 result = ERR_MEM;
969 }
970 if (dhcp->tries < 255) {
971 dhcp->tries++;
972 }
973 msecs = 10 * 1000;
974 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
975 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs));
976 return result;
977 }
978 #endif /* DHCP_DOES_ARP_CHECK */
979
980
981 /**
982 * Start the DHCP process, discover a DHCP server.
983 *
984 * @param netif the netif under DHCP control
985 */
986 static err_t
dhcp_discover(struct netif * netif)987 dhcp_discover(struct netif *netif)
988 {
989 struct dhcp *dhcp = netif_dhcp_data(netif);
990 err_t result = ERR_OK;
991 u16_t msecs;
992 u8_t i;
993 struct pbuf *p_out;
994 u16_t options_out_len;
995
996 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover()\n"));
997
998 ip4_addr_set_any(&dhcp->offered_ip_addr);
999 dhcp_set_state(dhcp, DHCP_STATE_SELECTING);
1000 /* create and initialize the DHCP message header */
1001 p_out = dhcp_create_msg(netif, dhcp, DHCP_DISCOVER, &options_out_len);
1002 if (p_out != NULL) {
1003 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1004 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n"));
1005
1006 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1007 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
1008
1009 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
1010 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
1011 options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);
1012 }
1013 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_SELECTING, msg_out, DHCP_DISCOVER, &options_out_len);
1014 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1015
1016 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER)\n"));
1017 udp_sendto_if_src(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif, IP4_ADDR_ANY);
1018 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()ing\n"));
1019 pbuf_free(p_out);
1020 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover: SELECTING\n"));
1021 } else {
1022 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_discover: could not allocate DHCP request\n"));
1023 }
1024 if (dhcp->tries < 255) {
1025 dhcp->tries++;
1026 }
1027 #if LWIP_DHCP_AUTOIP_COOP
1028 if (dhcp->tries >= LWIP_DHCP_AUTOIP_COOP_TRIES && dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_OFF) {
1029 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_ON;
1030 autoip_start(netif);
1031 }
1032 #endif /* LWIP_DHCP_AUTOIP_COOP */
1033 msecs = (u16_t)((dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000);
1034 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
1035 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs));
1036 return result;
1037 }
1038
1039
1040 /**
1041 * Bind the interface to the offered IP address.
1042 *
1043 * @param netif network interface to bind to the offered address
1044 */
1045 static void
dhcp_bind(struct netif * netif)1046 dhcp_bind(struct netif *netif)
1047 {
1048 u32_t timeout;
1049 struct dhcp *dhcp;
1050 ip4_addr_t sn_mask, gw_addr;
1051 LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;);
1052 dhcp = netif_dhcp_data(netif);
1053 LWIP_ERROR("dhcp_bind: dhcp != NULL", (dhcp != NULL), return;);
1054 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));
1055
1056 /* reset time used of lease */
1057 dhcp->lease_used = 0;
1058
1059 if (dhcp->offered_t0_lease != 0xffffffffUL) {
1060 /* set renewal period timer */
1061 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t0 renewal timer %"U32_F" secs\n", dhcp->offered_t0_lease));
1062 timeout = (dhcp->offered_t0_lease + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS;
1063 if (timeout > 0xffff) {
1064 timeout = 0xffff;
1065 }
1066 dhcp->t0_timeout = (u16_t)timeout;
1067 if (dhcp->t0_timeout == 0) {
1068 dhcp->t0_timeout = 1;
1069 }
1070 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t0_lease * 1000));
1071 }
1072
1073 /* temporary DHCP lease? */
1074 if (dhcp->offered_t1_renew != 0xffffffffUL) {
1075 /* set renewal period timer */
1076 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew));
1077 timeout = (dhcp->offered_t1_renew + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS;
1078 if (timeout > 0xffff) {
1079 timeout = 0xffff;
1080 }
1081 dhcp->t1_timeout = (u16_t)timeout;
1082 if (dhcp->t1_timeout == 0) {
1083 dhcp->t1_timeout = 1;
1084 }
1085 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew * 1000));
1086 dhcp->t1_renew_time = dhcp->t1_timeout;
1087 }
1088 /* set renewal period timer */
1089 if (dhcp->offered_t2_rebind != 0xffffffffUL) {
1090 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind));
1091 timeout = (dhcp->offered_t2_rebind + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS;
1092 if (timeout > 0xffff) {
1093 timeout = 0xffff;
1094 }
1095 dhcp->t2_timeout = (u16_t)timeout;
1096 if (dhcp->t2_timeout == 0) {
1097 dhcp->t2_timeout = 1;
1098 }
1099 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t2_rebind * 1000));
1100 dhcp->t2_rebind_time = dhcp->t2_timeout;
1101 }
1102
1103 /* If we have sub 1 minute lease, t2 and t1 will kick in at the same time. */
1104 if ((dhcp->t1_timeout >= dhcp->t2_timeout) && (dhcp->t2_timeout > 0)) {
1105 dhcp->t1_timeout = 0;
1106 }
1107
1108 if (dhcp->subnet_mask_given) {
1109 /* copy offered network mask */
1110 ip4_addr_copy(sn_mask, dhcp->offered_sn_mask);
1111 } else {
1112 /* subnet mask not given, choose a safe subnet mask given the network class */
1113 u8_t first_octet = ip4_addr1(&dhcp->offered_ip_addr);
1114 if (first_octet <= 127) {
1115 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xff000000UL));
1116 } else if (first_octet >= 192) {
1117 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffffff00UL));
1118 } else {
1119 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffff0000UL));
1120 }
1121 }
1122
1123 ip4_addr_copy(gw_addr, dhcp->offered_gw_addr);
1124
1125 #if LWIP_DHCP_AUTOIP_COOP
1126 if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
1127 autoip_stop(netif);
1128 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
1129 }
1130 #endif /* LWIP_DHCP_AUTOIP_COOP */
1131
1132 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): IP: 0x%08"X32_F" SN: 0x%08"X32_F" GW: 0x%08"X32_F"\n",
1133 ip4_addr_get_u32(&dhcp->offered_ip_addr), ip4_addr_get_u32(&sn_mask), ip4_addr_get_u32(&gw_addr)));
1134 /* netif is now bound to DHCP leased address - set this before assigning the address
1135 to ensure the callback can use dhcp_supplied_address() */
1136 dhcp_set_state(dhcp, DHCP_STATE_BOUND);
1137
1138 netif_set_addr(netif, &dhcp->offered_ip_addr, &sn_mask, &gw_addr);
1139 /* interface is used by routing now that an address is set */
1140 }
1141
1142 /**
1143 * @ingroup dhcp4
1144 * Renew an existing DHCP lease at the involved DHCP server.
1145 *
1146 * @param netif network interface which must renew its lease
1147 */
1148 err_t
dhcp_renew(struct netif * netif)1149 dhcp_renew(struct netif *netif)
1150 {
1151 struct dhcp *dhcp = netif_dhcp_data(netif);
1152 err_t result;
1153 u16_t msecs;
1154 u8_t i;
1155 struct pbuf *p_out;
1156 u16_t options_out_len;
1157
1158 LWIP_ASSERT_CORE_LOCKED();
1159 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_renew()\n"));
1160 dhcp_set_state(dhcp, DHCP_STATE_RENEWING);
1161
1162 /* create and initialize the DHCP message header */
1163 p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len);
1164 if (p_out != NULL) {
1165 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1166 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1167 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
1168
1169 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
1170 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
1171 options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);
1172 }
1173
1174 #if LWIP_NETIF_HOSTNAME
1175 options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif);
1176 #endif /* LWIP_NETIF_HOSTNAME */
1177
1178 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_RENEWING, msg_out, DHCP_REQUEST, &options_out_len);
1179 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1180
1181 result = udp_sendto_if(dhcp_pcb, p_out, &dhcp->server_ip_addr, LWIP_IANA_PORT_DHCP_SERVER, netif);
1182 pbuf_free(p_out);
1183
1184 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew: RENEWING\n"));
1185 } else {
1186 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_renew: could not allocate DHCP request\n"));
1187 result = ERR_MEM;
1188 }
1189 if (dhcp->tries < 255) {
1190 dhcp->tries++;
1191 }
1192 /* back-off on retries, but to a maximum of 20 seconds */
1193 msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000);
1194 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
1195 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs));
1196 return result;
1197 }
1198
1199 /**
1200 * Rebind with a DHCP server for an existing DHCP lease.
1201 *
1202 * @param netif network interface which must rebind with a DHCP server
1203 */
1204 static err_t
dhcp_rebind(struct netif * netif)1205 dhcp_rebind(struct netif *netif)
1206 {
1207 struct dhcp *dhcp = netif_dhcp_data(netif);
1208 err_t result;
1209 u16_t msecs;
1210 u8_t i;
1211 struct pbuf *p_out;
1212 u16_t options_out_len;
1213
1214 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n"));
1215 dhcp_set_state(dhcp, DHCP_STATE_REBINDING);
1216
1217 /* create and initialize the DHCP message header */
1218 p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len);
1219 if (p_out != NULL) {
1220 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1221 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1222 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
1223
1224 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
1225 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
1226 options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);
1227 }
1228
1229 #if LWIP_NETIF_HOSTNAME
1230 options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif);
1231 #endif /* LWIP_NETIF_HOSTNAME */
1232
1233 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_REBINDING, msg_out, DHCP_DISCOVER, &options_out_len);
1234 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1235
1236 /* broadcast to server */
1237 result = udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif);
1238 pbuf_free(p_out);
1239 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n"));
1240 } else {
1241 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_rebind: could not allocate DHCP request\n"));
1242 result = ERR_MEM;
1243 }
1244 if (dhcp->tries < 255) {
1245 dhcp->tries++;
1246 }
1247 msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000);
1248 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
1249 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs));
1250 return result;
1251 }
1252
1253 /**
1254 * Enter REBOOTING state to verify an existing lease
1255 *
1256 * @param netif network interface which must reboot
1257 */
1258 static err_t
dhcp_reboot(struct netif * netif)1259 dhcp_reboot(struct netif *netif)
1260 {
1261 struct dhcp *dhcp = netif_dhcp_data(netif);
1262 err_t result;
1263 u16_t msecs;
1264 u8_t i;
1265 struct pbuf *p_out;
1266 u16_t options_out_len;
1267
1268 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n"));
1269 dhcp_set_state(dhcp, DHCP_STATE_REBOOTING);
1270
1271 /* create and initialize the DHCP message header */
1272 p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len);
1273 if (p_out != NULL) {
1274 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1275 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1276 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN_MIN_REQUIRED);
1277
1278 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_REQUESTED_IP, 4);
1279 options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
1280
1281 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
1282 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
1283 options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);
1284 }
1285
1286 #if LWIP_NETIF_HOSTNAME
1287 options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif);
1288 #endif /* LWIP_NETIF_HOSTNAME */
1289
1290 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_REBOOTING, msg_out, DHCP_REQUEST, &options_out_len);
1291 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1292
1293 /* broadcast to server */
1294 result = udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif);
1295 pbuf_free(p_out);
1296 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot: REBOOTING\n"));
1297 } else {
1298 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_reboot: could not allocate DHCP request\n"));
1299 result = ERR_MEM;
1300 }
1301 if (dhcp->tries < 255) {
1302 dhcp->tries++;
1303 }
1304 msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000);
1305 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
1306 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot(): set request timeout %"U16_F" msecs\n", msecs));
1307 return result;
1308 }
1309
1310 /**
1311 * @ingroup dhcp4
1312 * Release a DHCP lease and stop DHCP statemachine (and AUTOIP if LWIP_DHCP_AUTOIP_COOP).
1313 *
1314 * @param netif network interface
1315 */
1316 void
dhcp_release_and_stop(struct netif * netif)1317 dhcp_release_and_stop(struct netif *netif)
1318 {
1319 struct dhcp *dhcp = netif_dhcp_data(netif);
1320 ip_addr_t server_ip_addr;
1321
1322 LWIP_ASSERT_CORE_LOCKED();
1323 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release_and_stop()\n"));
1324 if (dhcp == NULL) {
1325 return;
1326 }
1327
1328 /* already off? -> nothing to do */
1329 if (dhcp->state == DHCP_STATE_OFF) {
1330 return;
1331 }
1332
1333 ip_addr_copy(server_ip_addr, dhcp->server_ip_addr);
1334
1335 /* clean old DHCP offer */
1336 ip_addr_set_zero_ip4(&dhcp->server_ip_addr);
1337 ip4_addr_set_zero(&dhcp->offered_ip_addr);
1338 ip4_addr_set_zero(&dhcp->offered_sn_mask);
1339 ip4_addr_set_zero(&dhcp->offered_gw_addr);
1340 #if LWIP_DHCP_BOOTP_FILE
1341 ip4_addr_set_zero(&dhcp->offered_si_addr);
1342 #endif /* LWIP_DHCP_BOOTP_FILE */
1343 dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0;
1344 dhcp->t1_renew_time = dhcp->t2_rebind_time = dhcp->lease_used = dhcp->t0_timeout = 0;
1345
1346 /* send release message when current IP was assigned via DHCP */
1347 if (dhcp_supplied_address(netif)) {
1348 /* create and initialize the DHCP message header */
1349 struct pbuf *p_out;
1350 u16_t options_out_len;
1351 dhcp_set_state(dhcp, DHCP_STATE_OFF);
1352 p_out = dhcp_create_msg(netif, dhcp, DHCP_RELEASE, &options_out_len);
1353 if (p_out != NULL) {
1354 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1355 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_SERVER_ID, 4);
1356 options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(ip_2_ip4(&server_ip_addr))));
1357
1358 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, dhcp->state, msg_out, DHCP_RELEASE, &options_out_len);
1359 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1360
1361 udp_sendto_if(dhcp_pcb, p_out, &server_ip_addr, LWIP_IANA_PORT_DHCP_SERVER, netif);
1362 pbuf_free(p_out);
1363 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_STATE_OFF\n"));
1364 } else {
1365 /* sending release failed, but that's not a problem since the correct behaviour of dhcp does not rely on release */
1366 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n"));
1367 }
1368
1369 /* remove IP address from interface (prevents routing from selecting this interface) */
1370 netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4);
1371 } else {
1372 dhcp_set_state(dhcp, DHCP_STATE_OFF);
1373 }
1374
1375 #if LWIP_DHCP_AUTOIP_COOP
1376 if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
1377 autoip_stop(netif);
1378 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
1379 }
1380 #endif /* LWIP_DHCP_AUTOIP_COOP */
1381
1382 if (dhcp->pcb_allocated != 0) {
1383 dhcp_dec_pcb_refcount(); /* free DHCP PCB if not needed any more */
1384 dhcp->pcb_allocated = 0;
1385 }
1386 }
1387
1388 /**
1389 * @ingroup dhcp4
1390 * This function calls dhcp_release_and_stop() internally.
1391 * @deprecated Use dhcp_release_and_stop() instead.
1392 */
1393 err_t
dhcp_release(struct netif * netif)1394 dhcp_release(struct netif *netif)
1395 {
1396 dhcp_release_and_stop(netif);
1397 return ERR_OK;
1398 }
1399
1400 /**
1401 * @ingroup dhcp4
1402 * This function calls dhcp_release_and_stop() internally.
1403 * @deprecated Use dhcp_release_and_stop() instead.
1404 */
1405 void
dhcp_stop(struct netif * netif)1406 dhcp_stop(struct netif *netif)
1407 {
1408 dhcp_release_and_stop(netif);
1409 }
1410
1411 /*
1412 * Set the DHCP state of a DHCP client.
1413 *
1414 * If the state changed, reset the number of tries.
1415 */
1416 static void
dhcp_set_state(struct dhcp * dhcp,u8_t new_state)1417 dhcp_set_state(struct dhcp *dhcp, u8_t new_state)
1418 {
1419 if (new_state != dhcp->state) {
1420 dhcp->state = new_state;
1421 dhcp->tries = 0;
1422 dhcp->request_timeout = 0;
1423 }
1424 }
1425
1426 /*
1427 * Concatenate an option type and length field to the outgoing
1428 * DHCP message.
1429 *
1430 */
1431 static u16_t
dhcp_option(u16_t options_out_len,u8_t * options,u8_t option_type,u8_t option_len)1432 dhcp_option(u16_t options_out_len, u8_t *options, u8_t option_type, u8_t option_len)
1433 {
1434 LWIP_ASSERT("dhcp_option: options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN);
1435 options[options_out_len++] = option_type;
1436 options[options_out_len++] = option_len;
1437 return options_out_len;
1438 }
1439 /*
1440 * Concatenate a single byte to the outgoing DHCP message.
1441 *
1442 */
1443 static u16_t
dhcp_option_byte(u16_t options_out_len,u8_t * options,u8_t value)1444 dhcp_option_byte(u16_t options_out_len, u8_t *options, u8_t value)
1445 {
1446 LWIP_ASSERT("dhcp_option_byte: options_out_len < DHCP_OPTIONS_LEN", options_out_len < DHCP_OPTIONS_LEN);
1447 options[options_out_len++] = value;
1448 return options_out_len;
1449 }
1450
1451 static u16_t
dhcp_option_short(u16_t options_out_len,u8_t * options,u16_t value)1452 dhcp_option_short(u16_t options_out_len, u8_t *options, u16_t value)
1453 {
1454 LWIP_ASSERT("dhcp_option_short: options_out_len + 2 <= DHCP_OPTIONS_LEN", options_out_len + 2U <= DHCP_OPTIONS_LEN);
1455 options[options_out_len++] = (u8_t)((value & 0xff00U) >> 8);
1456 options[options_out_len++] = (u8_t) (value & 0x00ffU);
1457 return options_out_len;
1458 }
1459
1460 static u16_t
dhcp_option_long(u16_t options_out_len,u8_t * options,u32_t value)1461 dhcp_option_long(u16_t options_out_len, u8_t *options, u32_t value)
1462 {
1463 LWIP_ASSERT("dhcp_option_long: options_out_len + 4 <= DHCP_OPTIONS_LEN", options_out_len + 4U <= DHCP_OPTIONS_LEN);
1464 options[options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24);
1465 options[options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16);
1466 options[options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8);
1467 options[options_out_len++] = (u8_t)((value & 0x000000ffUL));
1468 return options_out_len;
1469 }
1470
1471 #if LWIP_NETIF_HOSTNAME
1472 static u16_t
dhcp_option_hostname(u16_t options_out_len,u8_t * options,struct netif * netif)1473 dhcp_option_hostname(u16_t options_out_len, u8_t *options, struct netif *netif)
1474 {
1475 if (netif->hostname != NULL) {
1476 size_t namelen = strlen(netif->hostname);
1477 if (namelen > 0) {
1478 size_t len;
1479 const char *p = netif->hostname;
1480 /* Shrink len to available bytes (need 2 bytes for OPTION_HOSTNAME
1481 and 1 byte for trailer) */
1482 size_t available = DHCP_OPTIONS_LEN - options_out_len - 3;
1483 LWIP_ASSERT("DHCP: hostname is too long!", namelen <= available);
1484 len = LWIP_MIN(namelen, available);
1485 LWIP_ASSERT("DHCP: hostname is too long!", len <= 0xFF);
1486 options_out_len = dhcp_option(options_out_len, options, DHCP_OPTION_HOSTNAME, (u8_t)len);
1487 while (len--) {
1488 options_out_len = dhcp_option_byte(options_out_len, options, *p++);
1489 }
1490 }
1491 }
1492 return options_out_len;
1493 }
1494 #endif /* LWIP_NETIF_HOSTNAME */
1495
1496 /**
1497 * Extract the DHCP message and the DHCP options.
1498 *
1499 * Extract the DHCP message and the DHCP options, each into a contiguous
1500 * piece of memory. As a DHCP message is variable sized by its options,
1501 * and also allows overriding some fields for options, the easy approach
1502 * is to first unfold the options into a contiguous piece of memory, and
1503 * use that further on.
1504 *
1505 */
1506 static err_t
dhcp_parse_reply(struct pbuf * p,struct dhcp * dhcp)1507 dhcp_parse_reply(struct pbuf *p, struct dhcp *dhcp)
1508 {
1509 u8_t *options;
1510 u16_t offset;
1511 u16_t offset_max;
1512 u16_t options_offset;
1513 u16_t options_idx;
1514 u16_t options_idx_max;
1515 struct pbuf *q;
1516 int parse_file_as_options = 0;
1517 int parse_sname_as_options = 0;
1518 struct dhcp_msg *msg_in;
1519 #if LWIP_DHCP_BOOTP_FILE
1520 int file_overloaded = 0;
1521 #endif
1522
1523 LWIP_UNUSED_ARG(dhcp);
1524
1525 /* clear received options */
1526 dhcp_clear_all_options(dhcp);
1527 /* check that beginning of dhcp_msg (up to and including chaddr) is in first pbuf */
1528 if (p->len < DHCP_SNAME_OFS) {
1529 return ERR_BUF;
1530 }
1531 msg_in = (struct dhcp_msg *)p->payload;
1532 #if LWIP_DHCP_BOOTP_FILE
1533 /* clear boot file name */
1534 dhcp->boot_file_name[0] = 0;
1535 #endif /* LWIP_DHCP_BOOTP_FILE */
1536
1537 /* parse options */
1538
1539 /* start with options field */
1540 options_idx = DHCP_OPTIONS_OFS;
1541 /* parse options to the end of the received packet */
1542 options_idx_max = p->tot_len;
1543 again:
1544 q = p;
1545 options_offset = options_idx;
1546 while ((q != NULL) && (options_idx >= q->len)) {
1547 options_idx = (u16_t)(options_idx - q->len);
1548 options_idx_max = (u16_t)(options_idx_max - q->len);
1549 q = q->next;
1550 }
1551 if (q == NULL) {
1552 return ERR_BUF;
1553 }
1554 offset = options_idx;
1555 offset_max = options_idx_max;
1556 options = (u8_t *)q->payload;
1557 /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */
1558 while ((q != NULL) && (offset < offset_max) && (options[offset] != DHCP_OPTION_END)) {
1559 u8_t op = options[offset];
1560 u8_t len;
1561 u8_t decode_len = 0;
1562 int decode_idx = -1;
1563 u16_t val_offset = (u16_t)(offset + 2);
1564 if (val_offset < offset) {
1565 /* overflow */
1566 return ERR_BUF;
1567 }
1568 /* len byte might be in the next pbuf */
1569 if ((offset + 1) < q->len) {
1570 len = options[offset + 1];
1571 } else {
1572 len = (q->next != NULL ? ((u8_t *)q->next->payload)[0] : 0);
1573 }
1574 /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F, msg_offset, q->len)); */
1575 decode_len = len;
1576 switch (op) {
1577 /* case(DHCP_OPTION_END): handled above */
1578 case (DHCP_OPTION_PAD):
1579 /* special option: no len encoded */
1580 decode_len = len = 0;
1581 /* will be increased below */
1582 break;
1583 case (DHCP_OPTION_SUBNET_MASK):
1584 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1585 decode_idx = DHCP_OPTION_IDX_SUBNET_MASK;
1586 break;
1587 case (DHCP_OPTION_ROUTER):
1588 decode_len = 4; /* only copy the first given router */
1589 LWIP_DHCP_INPUT_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;);
1590 decode_idx = DHCP_OPTION_IDX_ROUTER;
1591 break;
1592 #if LWIP_DHCP_PROVIDE_DNS_SERVERS
1593 case (DHCP_OPTION_DNS_SERVER):
1594 /* special case: there might be more than one server */
1595 LWIP_DHCP_INPUT_ERROR("len %% 4 == 0", len % 4 == 0, return ERR_VAL;);
1596 /* limit number of DNS servers */
1597 decode_len = LWIP_MIN(len, 4 * DNS_MAX_SERVERS);
1598 LWIP_DHCP_INPUT_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;);
1599 decode_idx = DHCP_OPTION_IDX_DNS_SERVER;
1600 break;
1601 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */
1602 case (DHCP_OPTION_LEASE_TIME):
1603 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1604 decode_idx = DHCP_OPTION_IDX_LEASE_TIME;
1605 break;
1606 #if LWIP_DHCP_GET_NTP_SRV
1607 case (DHCP_OPTION_NTP):
1608 /* special case: there might be more than one server */
1609 LWIP_DHCP_INPUT_ERROR("len %% 4 == 0", len % 4 == 0, return ERR_VAL;);
1610 /* limit number of NTP servers */
1611 decode_len = LWIP_MIN(len, 4 * LWIP_DHCP_MAX_NTP_SERVERS);
1612 LWIP_DHCP_INPUT_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;);
1613 decode_idx = DHCP_OPTION_IDX_NTP_SERVER;
1614 break;
1615 #endif /* LWIP_DHCP_GET_NTP_SRV*/
1616 case (DHCP_OPTION_OVERLOAD):
1617 LWIP_DHCP_INPUT_ERROR("len == 1", len == 1, return ERR_VAL;);
1618 /* decode overload only in options, not in file/sname: invalid packet */
1619 LWIP_DHCP_INPUT_ERROR("overload in file/sname", options_offset == DHCP_OPTIONS_OFS, return ERR_VAL;);
1620 decode_idx = DHCP_OPTION_IDX_OVERLOAD;
1621 break;
1622 case (DHCP_OPTION_MESSAGE_TYPE):
1623 LWIP_DHCP_INPUT_ERROR("len == 1", len == 1, return ERR_VAL;);
1624 decode_idx = DHCP_OPTION_IDX_MSG_TYPE;
1625 break;
1626 case (DHCP_OPTION_SERVER_ID):
1627 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1628 decode_idx = DHCP_OPTION_IDX_SERVER_ID;
1629 break;
1630 case (DHCP_OPTION_T1):
1631 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1632 decode_idx = DHCP_OPTION_IDX_T1;
1633 break;
1634 case (DHCP_OPTION_T2):
1635 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1636 decode_idx = DHCP_OPTION_IDX_T2;
1637 break;
1638 default:
1639 decode_len = 0;
1640 LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", (u16_t)op));
1641 LWIP_HOOK_DHCP_PARSE_OPTION(ip_current_netif(), dhcp, dhcp->state, msg_in,
1642 dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) ? (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) : 0,
1643 op, len, q, val_offset);
1644 break;
1645 }
1646 if (op == DHCP_OPTION_PAD) {
1647 offset++;
1648 } else {
1649 if (offset + len + 2 > 0xFFFF) {
1650 /* overflow */
1651 return ERR_BUF;
1652 }
1653 offset = (u16_t)(offset + len + 2);
1654 if (decode_len > 0) {
1655 u32_t value = 0;
1656 u16_t copy_len;
1657 decode_next:
1658 LWIP_ASSERT("check decode_idx", decode_idx >= 0 && decode_idx < DHCP_OPTION_IDX_MAX);
1659 if (!dhcp_option_given(dhcp, decode_idx)) {
1660 copy_len = LWIP_MIN(decode_len, 4);
1661 if (pbuf_copy_partial(q, &value, copy_len, val_offset) != copy_len) {
1662 return ERR_BUF;
1663 }
1664 if (decode_len > 4) {
1665 /* decode more than one u32_t */
1666 u16_t next_val_offset;
1667 LWIP_DHCP_INPUT_ERROR("decode_len %% 4 == 0", decode_len % 4 == 0, return ERR_VAL;);
1668 dhcp_got_option(dhcp, decode_idx);
1669 dhcp_set_option_value(dhcp, decode_idx, lwip_htonl(value));
1670 decode_len = (u8_t)(decode_len - 4);
1671 next_val_offset = (u16_t)(val_offset + 4);
1672 if (next_val_offset < val_offset) {
1673 /* overflow */
1674 return ERR_BUF;
1675 }
1676 val_offset = next_val_offset;
1677 decode_idx++;
1678 goto decode_next;
1679 } else if (decode_len == 4) {
1680 value = lwip_ntohl(value);
1681 } else {
1682 LWIP_DHCP_INPUT_ERROR("invalid decode_len", decode_len == 1, return ERR_VAL;);
1683 value = ((u8_t *)&value)[0];
1684 }
1685 dhcp_got_option(dhcp, decode_idx);
1686 dhcp_set_option_value(dhcp, decode_idx, value);
1687 }
1688 }
1689 }
1690 if (offset >= q->len) {
1691 offset = (u16_t)(offset - q->len);
1692 offset_max = (u16_t)(offset_max - q->len);
1693 if (offset < offset_max) {
1694 q = q->next;
1695 LWIP_DHCP_INPUT_ERROR("next pbuf was null", q != NULL, return ERR_VAL;);
1696 options = (u8_t *)q->payload;
1697 } else {
1698 /* We've run out of bytes, probably no end marker. Don't proceed. */
1699 return ERR_BUF;
1700 }
1701 }
1702 }
1703 /* is this an overloaded message? */
1704 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_OVERLOAD)) {
1705 u32_t overload = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_OVERLOAD);
1706 dhcp_clear_option(dhcp, DHCP_OPTION_IDX_OVERLOAD);
1707 if (overload == DHCP_OVERLOAD_FILE) {
1708 parse_file_as_options = 1;
1709 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded file field\n"));
1710 } else if (overload == DHCP_OVERLOAD_SNAME) {
1711 parse_sname_as_options = 1;
1712 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname field\n"));
1713 } else if (overload == DHCP_OVERLOAD_SNAME_FILE) {
1714 parse_sname_as_options = 1;
1715 parse_file_as_options = 1;
1716 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname and file field\n"));
1717 } else {
1718 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("invalid overload option: %d\n", (int)overload));
1719 }
1720 }
1721 if (parse_file_as_options) {
1722 /* if both are overloaded, parse file first and then sname (RFC 2131 ch. 4.1) */
1723 parse_file_as_options = 0;
1724 options_idx = DHCP_FILE_OFS;
1725 options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN;
1726 #if LWIP_DHCP_BOOTP_FILE
1727 file_overloaded = 1;
1728 #endif
1729 goto again;
1730 } else if (parse_sname_as_options) {
1731 parse_sname_as_options = 0;
1732 options_idx = DHCP_SNAME_OFS;
1733 options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN;
1734 goto again;
1735 }
1736 #if LWIP_DHCP_BOOTP_FILE
1737 if (!file_overloaded) {
1738 /* only do this for ACK messages */
1739 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) &&
1740 (dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK))
1741 /* copy bootp file name, don't care for sname (server hostname) */
1742 if (pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS) != (DHCP_FILE_LEN-1)) {
1743 return ERR_BUF;
1744 }
1745 /* make sure the string is really NULL-terminated */
1746 dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0;
1747 }
1748 #endif /* LWIP_DHCP_BOOTP_FILE */
1749 return ERR_OK;
1750 }
1751
1752 /**
1753 * If an incoming DHCP message is in response to us, then trigger the state machine
1754 */
1755 static void
dhcp_recv(void * arg,struct udp_pcb * pcb,struct pbuf * p,const ip_addr_t * addr,u16_t port)1756 dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port)
1757 {
1758 struct netif *netif = ip_current_input_netif();
1759 struct dhcp *dhcp = netif_dhcp_data(netif);
1760 struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload;
1761 u8_t msg_type;
1762 u8_t i;
1763 struct dhcp_msg *msg_in;
1764
1765 LWIP_UNUSED_ARG(arg);
1766
1767 /* Caught DHCP message from netif that does not have DHCP enabled? -> not interested */
1768 if ((dhcp == NULL) || (dhcp->pcb_allocated == 0)) {
1769 goto free_pbuf_and_return;
1770 }
1771
1772 LWIP_ASSERT("invalid server address type", IP_IS_V4(addr));
1773
1774 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,
1775 ip4_addr1_16(ip_2_ip4(addr)), ip4_addr2_16(ip_2_ip4(addr)), ip4_addr3_16(ip_2_ip4(addr)), ip4_addr4_16(ip_2_ip4(addr)), port));
1776 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len));
1777 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len));
1778 /* prevent warnings about unused arguments */
1779 LWIP_UNUSED_ARG(pcb);
1780 LWIP_UNUSED_ARG(addr);
1781 LWIP_UNUSED_ARG(port);
1782
1783 if (p->len < DHCP_MIN_REPLY_LEN) {
1784 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP reply message or pbuf too short\n"));
1785 goto free_pbuf_and_return;
1786 }
1787
1788 if (reply_msg->op != DHCP_BOOTREPLY) {
1789 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));
1790 goto free_pbuf_and_return;
1791 }
1792 /* iterate through hardware address and match against DHCP message */
1793 for (i = 0; i < netif->hwaddr_len && i < LWIP_MIN(DHCP_CHADDR_LEN, NETIF_MAX_HWADDR_LEN); i++) {
1794 if (netif->hwaddr[i] != reply_msg->chaddr[i]) {
1795 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
1796 ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n",
1797 (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i]));
1798 goto free_pbuf_and_return;
1799 }
1800 }
1801 /* match transaction ID against what we expected */
1802 if (lwip_ntohl(reply_msg->xid) != dhcp->xid) {
1803 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
1804 ("transaction id mismatch reply_msg->xid(%"X32_F")!=dhcp->xid(%"X32_F")\n", lwip_ntohl(reply_msg->xid), dhcp->xid));
1805 goto free_pbuf_and_return;
1806 }
1807 /* option fields could be unfold? */
1808 if (dhcp_parse_reply(p, dhcp) != ERR_OK) {
1809 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
1810 ("problem unfolding DHCP message - too short on memory?\n"));
1811 goto free_pbuf_and_return;
1812 }
1813
1814 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n"));
1815 /* obtain pointer to DHCP message type */
1816 if (!dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE)) {
1817 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP_OPTION_MESSAGE_TYPE option not found\n"));
1818 goto free_pbuf_and_return;
1819 }
1820
1821 msg_in = (struct dhcp_msg *)p->payload;
1822 /* read DHCP message type */
1823 msg_type = (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE);
1824 /* message type is DHCP ACK? */
1825 if (msg_type == DHCP_ACK) {
1826 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_ACK received\n"));
1827 /* in requesting state? */
1828 if (dhcp->state == DHCP_STATE_REQUESTING) {
1829 dhcp_handle_ack(netif, msg_in);
1830 #if DHCP_DOES_ARP_CHECK
1831 if ((netif->flags & NETIF_FLAG_ETHARP) != 0) {
1832 /* check if the acknowledged lease address is already in use */
1833 dhcp_check(netif);
1834 } else {
1835 /* bind interface to the acknowledged lease address */
1836 dhcp_bind(netif);
1837 }
1838 #else
1839 /* bind interface to the acknowledged lease address */
1840 dhcp_bind(netif);
1841 #endif
1842 }
1843 /* already bound to the given lease address? */
1844 else if ((dhcp->state == DHCP_STATE_REBOOTING) || (dhcp->state == DHCP_STATE_REBINDING) ||
1845 (dhcp->state == DHCP_STATE_RENEWING)) {
1846 dhcp_handle_ack(netif, msg_in);
1847 dhcp_bind(netif);
1848 }
1849 }
1850 /* received a DHCP_NAK in appropriate state? */
1851 else if ((msg_type == DHCP_NAK) &&
1852 ((dhcp->state == DHCP_STATE_REBOOTING) || (dhcp->state == DHCP_STATE_REQUESTING) ||
1853 (dhcp->state == DHCP_STATE_REBINDING) || (dhcp->state == DHCP_STATE_RENEWING ))) {
1854 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_NAK received\n"));
1855 dhcp_handle_nak(netif);
1856 }
1857 /* received a DHCP_OFFER in DHCP_STATE_SELECTING state? */
1858 else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_STATE_SELECTING)) {
1859 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_OFFER received in DHCP_STATE_SELECTING state\n"));
1860 /* remember offered lease */
1861 dhcp_handle_offer(netif, msg_in);
1862 }
1863
1864 free_pbuf_and_return:
1865 pbuf_free(p);
1866 }
1867
1868 /**
1869 * Create a DHCP request, fill in common headers
1870 *
1871 * @param netif the netif under DHCP control
1872 * @param dhcp dhcp control struct
1873 * @param message_type message type of the request
1874 */
1875 static struct pbuf *
dhcp_create_msg(struct netif * netif,struct dhcp * dhcp,u8_t message_type,u16_t * options_out_len)1876 dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type, u16_t *options_out_len)
1877 {
1878 u16_t i;
1879 struct pbuf *p_out;
1880 struct dhcp_msg *msg_out;
1881 u16_t options_out_len_loc;
1882
1883 #ifndef DHCP_GLOBAL_XID
1884 /** default global transaction identifier starting value (easy to match
1885 * with a packet analyser). We simply increment for each new request.
1886 * Predefine DHCP_GLOBAL_XID to a better value or a function call to generate one
1887 * at runtime, any supporting function prototypes can be defined in DHCP_GLOBAL_XID_HEADER */
1888 #if DHCP_CREATE_RAND_XID && defined(LWIP_RAND)
1889 static u32_t xid;
1890 #else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1891 static u32_t xid = 0xABCD0000;
1892 #endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1893 #else
1894 if (!xid_initialised) {
1895 xid = DHCP_GLOBAL_XID;
1896 xid_initialised = !xid_initialised;
1897 }
1898 #endif
1899 LWIP_ERROR("dhcp_create_msg: netif != NULL", (netif != NULL), return NULL;);
1900 LWIP_ERROR("dhcp_create_msg: dhcp != NULL", (dhcp != NULL), return NULL;);
1901 p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM);
1902 if (p_out == NULL) {
1903 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
1904 ("dhcp_create_msg(): could not allocate pbuf\n"));
1905 return NULL;
1906 }
1907 LWIP_ASSERT("dhcp_create_msg: check that first pbuf can hold struct dhcp_msg",
1908 (p_out->len >= sizeof(struct dhcp_msg)));
1909
1910 /* DHCP_REQUEST should reuse 'xid' from DHCPOFFER */
1911 if ((message_type != DHCP_REQUEST) || (dhcp->state == DHCP_STATE_REBOOTING)) {
1912 /* reuse transaction identifier in retransmissions */
1913 if (dhcp->tries == 0) {
1914 #if DHCP_CREATE_RAND_XID && defined(LWIP_RAND)
1915 xid = LWIP_RAND();
1916 #else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1917 xid++;
1918 #endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1919 }
1920 dhcp->xid = xid;
1921 }
1922 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE,
1923 ("transaction id xid(%"X32_F")\n", xid));
1924
1925 msg_out = (struct dhcp_msg *)p_out->payload;
1926 memset(msg_out, 0, sizeof(struct dhcp_msg));
1927
1928 msg_out->op = DHCP_BOOTREQUEST;
1929 /* @todo: make link layer independent */
1930 msg_out->htype = LWIP_IANA_HWTYPE_ETHERNET;
1931 msg_out->hlen = netif->hwaddr_len;
1932 msg_out->xid = lwip_htonl(dhcp->xid);
1933 /* we don't need the broadcast flag since we can receive unicast traffic
1934 before being fully configured! */
1935 /* set ciaddr to netif->ip_addr based on message_type and state */
1936 if ((message_type == DHCP_INFORM) || (message_type == DHCP_DECLINE) || (message_type == DHCP_RELEASE) ||
1937 ((message_type == DHCP_REQUEST) && /* DHCP_STATE_BOUND not used for sending! */
1938 ((dhcp->state == DHCP_STATE_RENEWING) || dhcp->state == DHCP_STATE_REBINDING))) {
1939 ip4_addr_copy(msg_out->ciaddr, *netif_ip4_addr(netif));
1940 }
1941 for (i = 0; i < LWIP_MIN(DHCP_CHADDR_LEN, NETIF_MAX_HWADDR_LEN); i++) {
1942 /* copy netif hardware address (padded with zeroes through memset already) */
1943 msg_out->chaddr[i] = netif->hwaddr[i];
1944 }
1945 msg_out->cookie = PP_HTONL(DHCP_MAGIC_COOKIE);
1946 /* Add option MESSAGE_TYPE */
1947 options_out_len_loc = dhcp_option(0, msg_out->options, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
1948 options_out_len_loc = dhcp_option_byte(options_out_len_loc, msg_out->options, message_type);
1949 if (options_out_len) {
1950 *options_out_len = options_out_len_loc;
1951 }
1952 return p_out;
1953 }
1954
1955 /**
1956 * Add a DHCP message trailer
1957 *
1958 * Adds the END option to the DHCP message, and if
1959 * necessary, up to three padding bytes.
1960 */
1961 static void
dhcp_option_trailer(u16_t options_out_len,u8_t * options,struct pbuf * p_out)1962 dhcp_option_trailer(u16_t options_out_len, u8_t *options, struct pbuf *p_out)
1963 {
1964 options[options_out_len++] = DHCP_OPTION_END;
1965 /* packet is too small, or not 4 byte aligned? */
1966 while (((options_out_len < DHCP_MIN_OPTIONS_LEN) || (options_out_len & 3)) &&
1967 (options_out_len < DHCP_OPTIONS_LEN)) {
1968 /* add a fill/padding byte */
1969 options[options_out_len++] = 0;
1970 }
1971 /* shrink the pbuf to the actual content length */
1972 pbuf_realloc(p_out, (u16_t)(sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + options_out_len));
1973 }
1974
1975 /** check if DHCP supplied netif->ip_addr
1976 *
1977 * @param netif the netif to check
1978 * @return 1 if DHCP supplied netif->ip_addr (states BOUND or RENEWING),
1979 * 0 otherwise
1980 */
1981 u8_t
dhcp_supplied_address(const struct netif * netif)1982 dhcp_supplied_address(const struct netif *netif)
1983 {
1984 if ((netif != NULL) && (netif_dhcp_data(netif) != NULL)) {
1985 struct dhcp *dhcp = netif_dhcp_data(netif);
1986 return (dhcp->state == DHCP_STATE_BOUND) || (dhcp->state == DHCP_STATE_RENEWING) ||
1987 (dhcp->state == DHCP_STATE_REBINDING);
1988 }
1989 return 0;
1990 }
1991
1992 #endif /* LWIP_IPV4 && LWIP_DHCP */
1993