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 #ifdef LOSCFG_NET_CONTAINER
442 NETIF_FOREACH(netif, get_root_net_group()) {
443 #else
444 NETIF_FOREACH(netif) {
445 #endif
446 /* only act on DHCP configured interfaces */
447 struct dhcp *dhcp = netif_dhcp_data(netif);
448 if ((dhcp != NULL) && (dhcp->state != DHCP_STATE_OFF)) {
449 /* compare lease time to expire timeout */
450 if (dhcp->t0_timeout && (++dhcp->lease_used == dhcp->t0_timeout)) {
451 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t0 timeout\n"));
452 /* this clients' lease time has expired */
453 dhcp_release_and_stop(netif);
454 dhcp_start(netif);
455 /* timer is active (non zero), and triggers (zeroes) now? */
456 } else if (dhcp->t2_rebind_time && (dhcp->t2_rebind_time-- == 1)) {
457 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t2 timeout\n"));
458 /* this clients' rebind timeout triggered */
459 dhcp_t2_timeout(netif);
460 /* timer is active (non zero), and triggers (zeroes) now */
461 } else if (dhcp->t1_renew_time && (dhcp->t1_renew_time-- == 1)) {
462 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t1 timeout\n"));
463 /* this clients' renewal timeout triggered */
464 dhcp_t1_timeout(netif);
465 }
466 }
467 }
468 }
469
470 #if LWIP_LOWPOWER
471 #include "lwip/lowpower.h"
472
473 u32_t
474 dhcp_coarse_tmr_tick(void)
475 {
476 struct netif *netif;
477 u32_t tick = 0;
478 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n"));
479 /* iterate through all network interfaces */
480 #ifdef LOSCFG_NET_CONTAINER
481 NETIF_FOREACH(netif, get_root_net_group())
482 #else
483 NETIF_FOREACH(netif)
484 #endif
485 {
486 struct dhcp *dhcp = netif_dhcp_data(netif);
487 if ((dhcp != NULL) && (dhcp->state != DHCP_STATE_OFF)) {
488 if (dhcp->t0_timeout > 0) {
489 if (dhcp->t0_timeout > dhcp->lease_used) {
490 SET_TMR_TICK(tick, dhcp->t0_timeout - dhcp->lease_used);
491 } else {
492 SET_TMR_TICK(tick, 1);
493 }
494 }
495 if (dhcp->t2_rebind_time > 0) {
496 SET_TMR_TICK(tick, dhcp->t2_rebind_time);
497 }
498 if (dhcp->t1_renew_time > 0) {
499 SET_TMR_TICK(tick, dhcp->t1_renew_time);
500 }
501 }
502 }
503 return tick;
504 }
505
506 u32_t
507 dhcp_fine_tmr_tick(void)
508 {
509 struct netif *netif;
510 u32_t tick = 0;
511 /* loop through netif's */
512 #ifdef LOSCFG_NET_CONTAINER
513 NETIF_FOREACH(netif, get_root_net_group())
514 #else
515 NETIF_FOREACH(netif)
516 #endif
517 {
518 struct dhcp *dhcp = netif_dhcp_data(netif);
519 if (dhcp != NULL) {
520 if (dhcp->request_timeout > 0) {
521 SET_TMR_TICK(tick, dhcp->request_timeout);
522 }
523 }
524 }
525 return tick;
526 }
527 #endif /* LWIP_LOWPOWER */
528
529 /**
530 * DHCP transaction timeout handling (this function must be called every 500ms,
531 * see @ref DHCP_FINE_TIMER_MSECS).
532 *
533 * A DHCP server is expected to respond within a short period of time.
534 * This timer checks whether an outstanding DHCP request is timed out.
535 */
536 void
537 dhcp_fine_tmr(void)
538 {
539 struct netif *netif;
540 /* loop through netif's */
541 #ifdef LOSCFG_NET_CONTAINER
542 NETIF_FOREACH(netif, get_root_net_group()) {
543 #else
544 NETIF_FOREACH(netif) {
545 #endif
546 struct dhcp *dhcp = netif_dhcp_data(netif);
547 /* only act on DHCP configured interfaces */
548 if (dhcp != NULL) {
549 /* timer is active (non zero), and is about to trigger now */
550 if (dhcp->request_timeout > 1) {
551 dhcp->request_timeout--;
552 } else if (dhcp->request_timeout == 1) {
553 dhcp->request_timeout--;
554 /* { dhcp->request_timeout == 0 } */
555 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_fine_tmr(): request timeout\n"));
556 /* this client's request timeout triggered */
557 dhcp_timeout(netif);
558 }
559 }
560 }
561 }
562
563 /**
564 * A DHCP negotiation transaction, or ARP request, has timed out.
565 *
566 * The timer that was started with the DHCP or ARP request has
567 * timed out, indicating no response was received in time.
568 *
569 * @param netif the netif under DHCP control
570 */
571 static void
572 dhcp_timeout(struct netif *netif)
573 {
574 struct dhcp *dhcp = netif_dhcp_data(netif);
575
576 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout()\n"));
577 /* back-off period has passed, or server selection timed out */
578 if ((dhcp->state == DHCP_STATE_BACKING_OFF) || (dhcp->state == DHCP_STATE_SELECTING)) {
579 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout(): restarting discovery\n"));
580 dhcp_discover(netif);
581 /* receiving the requested lease timed out */
582 } else if (dhcp->state == DHCP_STATE_REQUESTING) {
583 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, DHCP request timed out\n"));
584 if (dhcp->tries <= 5) {
585 dhcp_select(netif);
586 } else {
587 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, releasing, restarting\n"));
588 dhcp_release_and_stop(netif);
589 dhcp_start(netif);
590 }
591 #if DHCP_DOES_ARP_CHECK
592 /* received no ARP reply for the offered address (which is good) */
593 } else if (dhcp->state == DHCP_STATE_CHECKING) {
594 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): CHECKING, ARP request timed out\n"));
595 if (dhcp->tries <= 1) {
596 dhcp_check(netif);
597 /* no ARP replies on the offered address,
598 looks like the IP address is indeed free */
599 } else {
600 /* bind the interface to the offered address */
601 dhcp_bind(netif);
602 }
603 #endif /* DHCP_DOES_ARP_CHECK */
604 } else if (dhcp->state == DHCP_STATE_REBOOTING) {
605 if (dhcp->tries < REBOOT_TRIES) {
606 dhcp_reboot(netif);
607 } else {
608 dhcp_discover(netif);
609 }
610 }
611 }
612
613 /**
614 * The renewal period has timed out.
615 *
616 * @param netif the netif under DHCP control
617 */
618 static void
619 dhcp_t1_timeout(struct netif *netif)
620 {
621 struct dhcp *dhcp = netif_dhcp_data(netif);
622
623 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_t1_timeout()\n"));
624 if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_BOUND) ||
625 (dhcp->state == DHCP_STATE_RENEWING)) {
626 /* just retry to renew - note that the rebind timer (t2) will
627 * eventually time-out if renew tries fail. */
628 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
629 ("dhcp_t1_timeout(): must renew\n"));
630 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state
631 DHCP_STATE_RENEWING, not DHCP_STATE_BOUND */
632 dhcp_renew(netif);
633 /* Calculate next timeout */
634 if (((dhcp->t2_timeout - dhcp->lease_used) / 2) >= ((60 + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS)) {
635 dhcp->t1_renew_time = (u16_t)((dhcp->t2_timeout - dhcp->lease_used) / 2);
636 }
637 }
638 }
639
640 /**
641 * The rebind period has timed out.
642 *
643 * @param netif the netif under DHCP control
644 */
645 static void
646 dhcp_t2_timeout(struct netif *netif)
647 {
648 struct dhcp *dhcp = netif_dhcp_data(netif);
649
650 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t2_timeout()\n"));
651 if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_BOUND) ||
652 (dhcp->state == DHCP_STATE_RENEWING) || (dhcp->state == DHCP_STATE_REBINDING)) {
653 /* just retry to rebind */
654 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
655 ("dhcp_t2_timeout(): must rebind\n"));
656 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state
657 DHCP_STATE_REBINDING, not DHCP_STATE_BOUND */
658 dhcp_rebind(netif);
659 /* Calculate next timeout */
660 if (((dhcp->t0_timeout - dhcp->lease_used) / 2) >= ((60 + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS)) {
661 dhcp->t2_rebind_time = (u16_t)((dhcp->t0_timeout - dhcp->lease_used) / 2);
662 }
663 }
664 }
665
666 /**
667 * Handle a DHCP ACK packet
668 *
669 * @param netif the netif under DHCP control
670 */
671 static void
672 dhcp_handle_ack(struct netif *netif, struct dhcp_msg *msg_in)
673 {
674 struct dhcp *dhcp = netif_dhcp_data(netif);
675
676 #if LWIP_DHCP_PROVIDE_DNS_SERVERS || LWIP_DHCP_GET_NTP_SRV
677 u8_t n;
678 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS || LWIP_DHCP_GET_NTP_SRV */
679 #if LWIP_DHCP_GET_NTP_SRV
680 ip4_addr_t ntp_server_addrs[LWIP_DHCP_MAX_NTP_SERVERS];
681 #endif
682
683 /* clear options we might not get from the ACK */
684 ip4_addr_set_zero(&dhcp->offered_sn_mask);
685 ip4_addr_set_zero(&dhcp->offered_gw_addr);
686 #if LWIP_DHCP_BOOTP_FILE
687 ip4_addr_set_zero(&dhcp->offered_si_addr);
688 #endif /* LWIP_DHCP_BOOTP_FILE */
689
690 /* lease time given? */
691 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_LEASE_TIME)) {
692 /* remember offered lease time */
693 dhcp->offered_t0_lease = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_LEASE_TIME);
694 }
695 /* renewal period given? */
696 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T1)) {
697 /* remember given renewal period */
698 dhcp->offered_t1_renew = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T1);
699 } else {
700 /* calculate safe periods for renewal */
701 dhcp->offered_t1_renew = dhcp->offered_t0_lease / 2;
702 }
703
704 /* renewal period given? */
705 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T2)) {
706 /* remember given rebind period */
707 dhcp->offered_t2_rebind = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T2);
708 } else {
709 /* calculate safe periods for rebinding (offered_t0_lease * 0.875 -> 87.5%)*/
710 dhcp->offered_t2_rebind = (dhcp->offered_t0_lease * 7U) / 8U;
711 }
712
713 /* (y)our internet address */
714 ip4_addr_copy(dhcp->offered_ip_addr, msg_in->yiaddr);
715
716 #if LWIP_DHCP_BOOTP_FILE
717 /* copy boot server address,
718 boot file name copied in dhcp_parse_reply if not overloaded */
719 ip4_addr_copy(dhcp->offered_si_addr, msg_in->siaddr);
720 #endif /* LWIP_DHCP_BOOTP_FILE */
721
722 /* subnet mask given? */
723 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)) {
724 /* remember given subnet mask */
725 ip4_addr_set_u32(&dhcp->offered_sn_mask, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)));
726 dhcp->subnet_mask_given = 1;
727 } else {
728 dhcp->subnet_mask_given = 0;
729 }
730
731 /* gateway router */
732 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_ROUTER)) {
733 ip4_addr_set_u32(&dhcp->offered_gw_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_ROUTER)));
734 }
735
736 #if LWIP_DHCP_GET_NTP_SRV
737 /* NTP servers */
738 for (n = 0; (n < LWIP_DHCP_MAX_NTP_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_NTP_SERVER + n); n++) {
739 ip4_addr_set_u32(&ntp_server_addrs[n], lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_NTP_SERVER + n)));
740 }
741 dhcp_set_ntp_servers(n, ntp_server_addrs);
742 #endif /* LWIP_DHCP_GET_NTP_SRV */
743
744 #if LWIP_DHCP_PROVIDE_DNS_SERVERS
745 /* DNS servers */
746 for (n = 0; (n < LWIP_DHCP_PROVIDE_DNS_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n); n++) {
747 ip_addr_t dns_addr;
748 ip_addr_set_ip4_u32_val(dns_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n)));
749 dns_setserver(n, &dns_addr);
750 }
751 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */
752 }
753
754 /**
755 * @ingroup dhcp4
756 * Set a statically allocated struct dhcp to work with.
757 * Using this prevents dhcp_start to allocate it using mem_malloc.
758 *
759 * @param netif the netif for which to set the struct dhcp
760 * @param dhcp (uninitialised) dhcp struct allocated by the application
761 */
762 void
763 dhcp_set_struct(struct netif *netif, struct dhcp *dhcp)
764 {
765 LWIP_ASSERT_CORE_LOCKED();
766 LWIP_ASSERT("netif != NULL", netif != NULL);
767 LWIP_ASSERT("dhcp != NULL", dhcp != NULL);
768 LWIP_ASSERT("netif already has a struct dhcp set", netif_dhcp_data(netif) == NULL);
769
770 /* clear data structure */
771 memset(dhcp, 0, sizeof(struct dhcp));
772 /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */
773 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp);
774 }
775
776 /**
777 * @ingroup dhcp4
778 * Removes a struct dhcp from a netif.
779 *
780 * ATTENTION: Only use this when not using dhcp_set_struct() to allocate the
781 * struct dhcp since the memory is passed back to the heap.
782 *
783 * @param netif the netif from which to remove the struct dhcp
784 */
785 void dhcp_cleanup(struct netif *netif)
786 {
787 LWIP_ASSERT_CORE_LOCKED();
788 LWIP_ASSERT("netif != NULL", netif != NULL);
789
790 if (netif_dhcp_data(netif) != NULL) {
791 mem_free(netif_dhcp_data(netif));
792 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, NULL);
793 }
794 }
795
796 /**
797 * @ingroup dhcp4
798 * Start DHCP negotiation for a network interface.
799 *
800 * If no DHCP client instance was attached to this interface,
801 * a new client is created first. If a DHCP client instance
802 * was already present, it restarts negotiation.
803 *
804 * @param netif The lwIP network interface
805 * @return lwIP error code
806 * - ERR_OK - No error
807 * - ERR_MEM - Out of memory
808 */
809 err_t
810 dhcp_start(struct netif *netif)
811 {
812 struct dhcp *dhcp;
813 err_t result;
814
815 LWIP_ASSERT_CORE_LOCKED();
816 LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;);
817 LWIP_ERROR("netif is not up, old style port?", netif_is_up(netif), return ERR_ARG;);
818 dhcp = netif_dhcp_data(netif);
819 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));
820
821 /* check MTU of the netif */
822 if (netif->mtu < DHCP_MAX_MSG_LEN_MIN_REQUIRED) {
823 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): Cannot use this netif with DHCP: MTU is too small\n"));
824 return ERR_MEM;
825 }
826
827 /* no DHCP client attached yet? */
828 if (dhcp == NULL) {
829 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): mallocing new DHCP client\n"));
830 dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp));
831 if (dhcp == NULL) {
832 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n"));
833 return ERR_MEM;
834 }
835
836 /* store this dhcp client in the netif */
837 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp);
838 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): allocated dhcp"));
839 /* already has DHCP client attached */
840 } else {
841 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(): restarting DHCP configuration\n"));
842
843 if (dhcp->pcb_allocated != 0) {
844 dhcp_dec_pcb_refcount(); /* free DHCP PCB if not needed any more */
845 }
846 /* dhcp is cleared below, no need to reset flag*/
847 }
848
849 /* clear data structure */
850 memset(dhcp, 0, sizeof(struct dhcp));
851 /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */
852
853 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n"));
854
855 if (dhcp_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP PCB is allocated */
856 return ERR_MEM;
857 }
858 dhcp->pcb_allocated = 1;
859
860 if (!netif_is_link_up(netif)) {
861 /* set state INIT and wait for dhcp_network_changed() to call dhcp_discover() */
862 dhcp_set_state(dhcp, DHCP_STATE_INIT);
863 return ERR_OK;
864 }
865
866 /* (re)start the DHCP negotiation */
867 result = dhcp_discover(netif);
868 if (result != ERR_OK) {
869 /* free resources allocated above */
870 dhcp_release_and_stop(netif);
871 return ERR_MEM;
872 }
873 return result;
874 }
875
876 /**
877 * @ingroup dhcp4
878 * Inform a DHCP server of our manual configuration.
879 *
880 * This informs DHCP servers of our fixed IP address configuration
881 * by sending an INFORM message. It does not involve DHCP address
882 * configuration, it is just here to be nice to the network.
883 *
884 * @param netif The lwIP network interface
885 */
886 void
887 dhcp_inform(struct netif *netif)
888 {
889 struct dhcp dhcp;
890 struct pbuf *p_out;
891 u16_t options_out_len;
892
893 LWIP_ASSERT_CORE_LOCKED();
894 LWIP_ERROR("netif != NULL", (netif != NULL), return;);
895
896 if (dhcp_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP PCB is allocated */
897 return;
898 }
899
900 memset(&dhcp, 0, sizeof(struct dhcp));
901 dhcp_set_state(&dhcp, DHCP_STATE_INFORMING);
902
903 /* create and initialize the DHCP message header */
904 p_out = dhcp_create_msg(netif, &dhcp, DHCP_INFORM, &options_out_len);
905 if (p_out != NULL) {
906 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
907 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
908 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
909
910 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, &dhcp, DHCP_STATE_INFORMING, msg_out, DHCP_INFORM, &options_out_len);
911 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
912
913 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n"));
914
915 udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif);
916
917 pbuf_free(p_out);
918 } else {
919 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform: could not allocate DHCP request\n"));
920 }
921
922 dhcp_dec_pcb_refcount(); /* delete DHCP PCB if not needed any more */
923 }
924
925 /** Handle a possible change in the network configuration.
926 *
927 * This enters the REBOOTING state to verify that the currently bound
928 * address is still valid.
929 */
930 void
931 dhcp_network_changed(struct netif *netif)
932 {
933 struct dhcp *dhcp = netif_dhcp_data(netif);
934
935 if (!dhcp) {
936 return;
937 }
938 switch (dhcp->state) {
939 case DHCP_STATE_REBINDING:
940 case DHCP_STATE_RENEWING:
941 case DHCP_STATE_BOUND:
942 case DHCP_STATE_REBOOTING:
943 dhcp->tries = 0;
944 dhcp_reboot(netif);
945 break;
946 case DHCP_STATE_OFF:
947 /* stay off */
948 break;
949 default:
950 LWIP_ASSERT("invalid dhcp->state", dhcp->state <= DHCP_STATE_BACKING_OFF);
951 /* INIT/REQUESTING/CHECKING/BACKING_OFF restart with new 'rid' because the
952 state changes, SELECTING: continue with current 'rid' as we stay in the
953 same state */
954 #if LWIP_DHCP_AUTOIP_COOP
955 if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
956 autoip_stop(netif);
957 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
958 }
959 #endif /* LWIP_DHCP_AUTOIP_COOP */
960 /* ensure we start with short timeouts, even if already discovering */
961 dhcp->tries = 0;
962 dhcp_discover(netif);
963 break;
964 }
965 }
966
967 #if DHCP_DOES_ARP_CHECK
968 /**
969 * Match an ARP reply with the offered IP address:
970 * check whether the offered IP address is not in use using ARP
971 *
972 * @param netif the network interface on which the reply was received
973 * @param addr The IP address we received a reply from
974 */
975 void
976 dhcp_arp_reply(struct netif *netif, const ip4_addr_t *addr)
977 {
978 struct dhcp *dhcp;
979
980 LWIP_ERROR("netif != NULL", (netif != NULL), return;);
981 dhcp = netif_dhcp_data(netif);
982 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_arp_reply()\n"));
983 /* is a DHCP client doing an ARP check? */
984 if ((dhcp != NULL) && (dhcp->state == DHCP_STATE_CHECKING)) {
985 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_arp_reply(): CHECKING, arp reply for 0x%08"X32_F"\n",
986 ip4_addr_get_u32(addr)));
987 /* did a host respond with the address we
988 were offered by the DHCP server? */
989 if (ip4_addr_cmp(addr, &dhcp->offered_ip_addr)) {
990 /* we will not accept the offered address */
991 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
992 ("dhcp_arp_reply(): arp reply matched with offered address, declining\n"));
993 dhcp_decline(netif);
994 }
995 }
996 }
997
998 /**
999 * Decline an offered lease.
1000 *
1001 * Tell the DHCP server we do not accept the offered address.
1002 * One reason to decline the lease is when we find out the address
1003 * is already in use by another host (through ARP).
1004 *
1005 * @param netif the netif under DHCP control
1006 */
1007 static err_t
1008 dhcp_decline(struct netif *netif)
1009 {
1010 struct dhcp *dhcp = netif_dhcp_data(netif);
1011 err_t result;
1012 u16_t msecs;
1013 struct pbuf *p_out;
1014 u16_t options_out_len;
1015
1016 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline()\n"));
1017 dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF);
1018 /* create and initialize the DHCP message header */
1019 p_out = dhcp_create_msg(netif, dhcp, DHCP_DECLINE, &options_out_len);
1020 if (p_out != NULL) {
1021 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1022 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_REQUESTED_IP, 4);
1023 options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
1024
1025 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_BACKING_OFF, msg_out, DHCP_DECLINE, &options_out_len);
1026 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1027
1028 /* per section 4.4.4, broadcast DECLINE messages */
1029 result = udp_sendto_if_src(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif, IP4_ADDR_ANY);
1030 pbuf_free(p_out);
1031 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_decline: BACKING OFF\n"));
1032 } else {
1033 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
1034 ("dhcp_decline: could not allocate DHCP request\n"));
1035 result = ERR_MEM;
1036 }
1037 if (dhcp->tries < 255) {
1038 dhcp->tries++;
1039 }
1040 msecs = 10 * 1000;
1041 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
1042 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs));
1043 return result;
1044 }
1045 #endif /* DHCP_DOES_ARP_CHECK */
1046
1047
1048 /**
1049 * Start the DHCP process, discover a DHCP server.
1050 *
1051 * @param netif the netif under DHCP control
1052 */
1053 static err_t
1054 dhcp_discover(struct netif *netif)
1055 {
1056 struct dhcp *dhcp = netif_dhcp_data(netif);
1057 err_t result = ERR_OK;
1058 u16_t msecs;
1059 u8_t i;
1060 struct pbuf *p_out;
1061 u16_t options_out_len;
1062
1063 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover()\n"));
1064
1065 ip4_addr_set_any(&dhcp->offered_ip_addr);
1066 dhcp_set_state(dhcp, DHCP_STATE_SELECTING);
1067 /* create and initialize the DHCP message header */
1068 p_out = dhcp_create_msg(netif, dhcp, DHCP_DISCOVER, &options_out_len);
1069 if (p_out != NULL) {
1070 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1071 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n"));
1072
1073 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1074 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
1075
1076 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
1077 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
1078 options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);
1079 }
1080 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_SELECTING, msg_out, DHCP_DISCOVER, &options_out_len);
1081 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1082
1083 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER)\n"));
1084 udp_sendto_if_src(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif, IP4_ADDR_ANY);
1085 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()ing\n"));
1086 pbuf_free(p_out);
1087 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover: SELECTING\n"));
1088 } else {
1089 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_discover: could not allocate DHCP request\n"));
1090 }
1091 if (dhcp->tries < 255) {
1092 dhcp->tries++;
1093 }
1094 #if LWIP_DHCP_AUTOIP_COOP
1095 if (dhcp->tries >= LWIP_DHCP_AUTOIP_COOP_TRIES && dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_OFF) {
1096 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_ON;
1097 autoip_start(netif);
1098 }
1099 #endif /* LWIP_DHCP_AUTOIP_COOP */
1100 msecs = (u16_t)((dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000);
1101 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
1102 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs));
1103 return result;
1104 }
1105
1106
1107 /**
1108 * Bind the interface to the offered IP address.
1109 *
1110 * @param netif network interface to bind to the offered address
1111 */
1112 static void
1113 dhcp_bind(struct netif *netif)
1114 {
1115 u32_t timeout;
1116 struct dhcp *dhcp;
1117 ip4_addr_t sn_mask, gw_addr;
1118 LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;);
1119 dhcp = netif_dhcp_data(netif);
1120 LWIP_ERROR("dhcp_bind: dhcp != NULL", (dhcp != NULL), return;);
1121 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));
1122
1123 /* reset time used of lease */
1124 dhcp->lease_used = 0;
1125
1126 if (dhcp->offered_t0_lease != 0xffffffffUL) {
1127 /* set renewal period timer */
1128 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t0 renewal timer %"U32_F" secs\n", dhcp->offered_t0_lease));
1129 timeout = (dhcp->offered_t0_lease + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS;
1130 if (timeout > 0xffff) {
1131 timeout = 0xffff;
1132 }
1133 dhcp->t0_timeout = (u16_t)timeout;
1134 if (dhcp->t0_timeout == 0) {
1135 dhcp->t0_timeout = 1;
1136 }
1137 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t0_lease * 1000));
1138 }
1139
1140 /* temporary DHCP lease? */
1141 if (dhcp->offered_t1_renew != 0xffffffffUL) {
1142 /* set renewal period timer */
1143 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew));
1144 timeout = (dhcp->offered_t1_renew + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS;
1145 if (timeout > 0xffff) {
1146 timeout = 0xffff;
1147 }
1148 dhcp->t1_timeout = (u16_t)timeout;
1149 if (dhcp->t1_timeout == 0) {
1150 dhcp->t1_timeout = 1;
1151 }
1152 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew * 1000));
1153 dhcp->t1_renew_time = dhcp->t1_timeout;
1154 }
1155 /* set renewal period timer */
1156 if (dhcp->offered_t2_rebind != 0xffffffffUL) {
1157 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind));
1158 timeout = (dhcp->offered_t2_rebind + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS;
1159 if (timeout > 0xffff) {
1160 timeout = 0xffff;
1161 }
1162 dhcp->t2_timeout = (u16_t)timeout;
1163 if (dhcp->t2_timeout == 0) {
1164 dhcp->t2_timeout = 1;
1165 }
1166 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t2_rebind * 1000));
1167 dhcp->t2_rebind_time = dhcp->t2_timeout;
1168 }
1169
1170 /* If we have sub 1 minute lease, t2 and t1 will kick in at the same time. */
1171 if ((dhcp->t1_timeout >= dhcp->t2_timeout) && (dhcp->t2_timeout > 0)) {
1172 dhcp->t1_timeout = 0;
1173 }
1174
1175 if (dhcp->subnet_mask_given) {
1176 /* copy offered network mask */
1177 ip4_addr_copy(sn_mask, dhcp->offered_sn_mask);
1178 } else {
1179 /* subnet mask not given, choose a safe subnet mask given the network class */
1180 u8_t first_octet = ip4_addr1(&dhcp->offered_ip_addr);
1181 if (first_octet <= 127) {
1182 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xff000000UL));
1183 } else if (first_octet >= 192) {
1184 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffffff00UL));
1185 } else {
1186 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffff0000UL));
1187 }
1188 }
1189
1190 ip4_addr_copy(gw_addr, dhcp->offered_gw_addr);
1191
1192 #if LWIP_DHCP_AUTOIP_COOP
1193 if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
1194 autoip_stop(netif);
1195 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
1196 }
1197 #endif /* LWIP_DHCP_AUTOIP_COOP */
1198
1199 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",
1200 ip4_addr_get_u32(&dhcp->offered_ip_addr), ip4_addr_get_u32(&sn_mask), ip4_addr_get_u32(&gw_addr)));
1201 /* netif is now bound to DHCP leased address - set this before assigning the address
1202 to ensure the callback can use dhcp_supplied_address() */
1203 dhcp_set_state(dhcp, DHCP_STATE_BOUND);
1204
1205 netif_set_addr(netif, &dhcp->offered_ip_addr, &sn_mask, &gw_addr);
1206 /* interface is used by routing now that an address is set */
1207 }
1208
1209 /**
1210 * @ingroup dhcp4
1211 * Renew an existing DHCP lease at the involved DHCP server.
1212 *
1213 * @param netif network interface which must renew its lease
1214 */
1215 err_t
1216 dhcp_renew(struct netif *netif)
1217 {
1218 struct dhcp *dhcp = netif_dhcp_data(netif);
1219 err_t result;
1220 u16_t msecs;
1221 u8_t i;
1222 struct pbuf *p_out;
1223 u16_t options_out_len;
1224
1225 LWIP_ASSERT_CORE_LOCKED();
1226 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_renew()\n"));
1227 dhcp_set_state(dhcp, DHCP_STATE_RENEWING);
1228
1229 /* create and initialize the DHCP message header */
1230 p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len);
1231 if (p_out != NULL) {
1232 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1233 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1234 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
1235
1236 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
1237 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
1238 options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);
1239 }
1240
1241 #if LWIP_NETIF_HOSTNAME
1242 options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif);
1243 #endif /* LWIP_NETIF_HOSTNAME */
1244
1245 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_RENEWING, msg_out, DHCP_REQUEST, &options_out_len);
1246 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1247
1248 result = udp_sendto_if(dhcp_pcb, p_out, &dhcp->server_ip_addr, LWIP_IANA_PORT_DHCP_SERVER, netif);
1249 pbuf_free(p_out);
1250
1251 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew: RENEWING\n"));
1252 } else {
1253 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_renew: could not allocate DHCP request\n"));
1254 result = ERR_MEM;
1255 }
1256 if (dhcp->tries < 255) {
1257 dhcp->tries++;
1258 }
1259 /* back-off on retries, but to a maximum of 20 seconds */
1260 msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000);
1261 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
1262 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs));
1263 return result;
1264 }
1265
1266 /**
1267 * Rebind with a DHCP server for an existing DHCP lease.
1268 *
1269 * @param netif network interface which must rebind with a DHCP server
1270 */
1271 static err_t
1272 dhcp_rebind(struct netif *netif)
1273 {
1274 struct dhcp *dhcp = netif_dhcp_data(netif);
1275 err_t result;
1276 u16_t msecs;
1277 u8_t i;
1278 struct pbuf *p_out;
1279 u16_t options_out_len;
1280
1281 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n"));
1282 dhcp_set_state(dhcp, DHCP_STATE_REBINDING);
1283
1284 /* create and initialize the DHCP message header */
1285 p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len);
1286 if (p_out != NULL) {
1287 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1288 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1289 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
1290
1291 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
1292 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
1293 options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);
1294 }
1295
1296 #if LWIP_NETIF_HOSTNAME
1297 options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif);
1298 #endif /* LWIP_NETIF_HOSTNAME */
1299
1300 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_REBINDING, msg_out, DHCP_DISCOVER, &options_out_len);
1301 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1302
1303 /* broadcast to server */
1304 result = udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif);
1305 pbuf_free(p_out);
1306 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n"));
1307 } else {
1308 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_rebind: could not allocate DHCP request\n"));
1309 result = ERR_MEM;
1310 }
1311 if (dhcp->tries < 255) {
1312 dhcp->tries++;
1313 }
1314 msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000);
1315 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
1316 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs));
1317 return result;
1318 }
1319
1320 /**
1321 * Enter REBOOTING state to verify an existing lease
1322 *
1323 * @param netif network interface which must reboot
1324 */
1325 static err_t
1326 dhcp_reboot(struct netif *netif)
1327 {
1328 struct dhcp *dhcp = netif_dhcp_data(netif);
1329 err_t result;
1330 u16_t msecs;
1331 u8_t i;
1332 struct pbuf *p_out;
1333 u16_t options_out_len;
1334
1335 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n"));
1336 dhcp_set_state(dhcp, DHCP_STATE_REBOOTING);
1337
1338 /* create and initialize the DHCP message header */
1339 p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len);
1340 if (p_out != NULL) {
1341 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1342 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1343 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN_MIN_REQUIRED);
1344
1345 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_REQUESTED_IP, 4);
1346 options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
1347
1348 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
1349 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
1350 options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);
1351 }
1352
1353 #if LWIP_NETIF_HOSTNAME
1354 options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif);
1355 #endif /* LWIP_NETIF_HOSTNAME */
1356
1357 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_REBOOTING, msg_out, DHCP_REQUEST, &options_out_len);
1358 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1359
1360 /* broadcast to server */
1361 result = udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif);
1362 pbuf_free(p_out);
1363 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot: REBOOTING\n"));
1364 } else {
1365 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_reboot: could not allocate DHCP request\n"));
1366 result = ERR_MEM;
1367 }
1368 if (dhcp->tries < 255) {
1369 dhcp->tries++;
1370 }
1371 msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000);
1372 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
1373 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot(): set request timeout %"U16_F" msecs\n", msecs));
1374 return result;
1375 }
1376
1377 /**
1378 * @ingroup dhcp4
1379 * Release a DHCP lease and stop DHCP statemachine (and AUTOIP if LWIP_DHCP_AUTOIP_COOP).
1380 *
1381 * @param netif network interface
1382 */
1383 void
1384 dhcp_release_and_stop(struct netif *netif)
1385 {
1386 struct dhcp *dhcp = netif_dhcp_data(netif);
1387 ip_addr_t server_ip_addr;
1388
1389 LWIP_ASSERT_CORE_LOCKED();
1390 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release_and_stop()\n"));
1391 if (dhcp == NULL) {
1392 return;
1393 }
1394
1395 /* already off? -> nothing to do */
1396 if (dhcp->state == DHCP_STATE_OFF) {
1397 return;
1398 }
1399
1400 ip_addr_copy(server_ip_addr, dhcp->server_ip_addr);
1401
1402 /* clean old DHCP offer */
1403 ip_addr_set_zero_ip4(&dhcp->server_ip_addr);
1404 ip4_addr_set_zero(&dhcp->offered_ip_addr);
1405 ip4_addr_set_zero(&dhcp->offered_sn_mask);
1406 ip4_addr_set_zero(&dhcp->offered_gw_addr);
1407 #if LWIP_DHCP_BOOTP_FILE
1408 ip4_addr_set_zero(&dhcp->offered_si_addr);
1409 #endif /* LWIP_DHCP_BOOTP_FILE */
1410 dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0;
1411 dhcp->t1_renew_time = dhcp->t2_rebind_time = dhcp->lease_used = dhcp->t0_timeout = 0;
1412
1413 /* send release message when current IP was assigned via DHCP */
1414 if (dhcp_supplied_address(netif)) {
1415 /* create and initialize the DHCP message header */
1416 struct pbuf *p_out;
1417 u16_t options_out_len;
1418 dhcp_set_state(dhcp, DHCP_STATE_OFF);
1419 p_out = dhcp_create_msg(netif, dhcp, DHCP_RELEASE, &options_out_len);
1420 if (p_out != NULL) {
1421 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1422 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_SERVER_ID, 4);
1423 options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(ip_2_ip4(&server_ip_addr))));
1424
1425 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, dhcp->state, msg_out, DHCP_RELEASE, &options_out_len);
1426 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1427
1428 udp_sendto_if(dhcp_pcb, p_out, &server_ip_addr, LWIP_IANA_PORT_DHCP_SERVER, netif);
1429 pbuf_free(p_out);
1430 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_STATE_OFF\n"));
1431 } else {
1432 /* sending release failed, but that's not a problem since the correct behaviour of dhcp does not rely on release */
1433 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n"));
1434 }
1435
1436 /* remove IP address from interface (prevents routing from selecting this interface) */
1437 netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4);
1438 } else {
1439 dhcp_set_state(dhcp, DHCP_STATE_OFF);
1440 }
1441
1442 #if LWIP_DHCP_AUTOIP_COOP
1443 if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
1444 autoip_stop(netif);
1445 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
1446 }
1447 #endif /* LWIP_DHCP_AUTOIP_COOP */
1448
1449 if (dhcp->pcb_allocated != 0) {
1450 dhcp_dec_pcb_refcount(); /* free DHCP PCB if not needed any more */
1451 dhcp->pcb_allocated = 0;
1452 }
1453 }
1454
1455 /**
1456 * @ingroup dhcp4
1457 * This function calls dhcp_release_and_stop() internally.
1458 * @deprecated Use dhcp_release_and_stop() instead.
1459 */
1460 err_t
1461 dhcp_release(struct netif *netif)
1462 {
1463 dhcp_release_and_stop(netif);
1464 return ERR_OK;
1465 }
1466
1467 /**
1468 * @ingroup dhcp4
1469 * This function calls dhcp_release_and_stop() internally.
1470 * @deprecated Use dhcp_release_and_stop() instead.
1471 */
1472 void
1473 dhcp_stop(struct netif *netif)
1474 {
1475 dhcp_release_and_stop(netif);
1476 }
1477
1478 /*
1479 * Set the DHCP state of a DHCP client.
1480 *
1481 * If the state changed, reset the number of tries.
1482 */
1483 static void
1484 dhcp_set_state(struct dhcp *dhcp, u8_t new_state)
1485 {
1486 if (new_state != dhcp->state) {
1487 dhcp->state = new_state;
1488 dhcp->tries = 0;
1489 dhcp->request_timeout = 0;
1490 }
1491 }
1492
1493 /*
1494 * Concatenate an option type and length field to the outgoing
1495 * DHCP message.
1496 *
1497 */
1498 static u16_t
1499 dhcp_option(u16_t options_out_len, u8_t *options, u8_t option_type, u8_t option_len)
1500 {
1501 LWIP_ASSERT("dhcp_option: options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN);
1502 options[options_out_len++] = option_type;
1503 options[options_out_len++] = option_len;
1504 return options_out_len;
1505 }
1506 /*
1507 * Concatenate a single byte to the outgoing DHCP message.
1508 *
1509 */
1510 static u16_t
1511 dhcp_option_byte(u16_t options_out_len, u8_t *options, u8_t value)
1512 {
1513 LWIP_ASSERT("dhcp_option_byte: options_out_len < DHCP_OPTIONS_LEN", options_out_len < DHCP_OPTIONS_LEN);
1514 options[options_out_len++] = value;
1515 return options_out_len;
1516 }
1517
1518 static u16_t
1519 dhcp_option_short(u16_t options_out_len, u8_t *options, u16_t value)
1520 {
1521 LWIP_ASSERT("dhcp_option_short: options_out_len + 2 <= DHCP_OPTIONS_LEN", options_out_len + 2U <= DHCP_OPTIONS_LEN);
1522 options[options_out_len++] = (u8_t)((value & 0xff00U) >> 8);
1523 options[options_out_len++] = (u8_t) (value & 0x00ffU);
1524 return options_out_len;
1525 }
1526
1527 static u16_t
1528 dhcp_option_long(u16_t options_out_len, u8_t *options, u32_t value)
1529 {
1530 LWIP_ASSERT("dhcp_option_long: options_out_len + 4 <= DHCP_OPTIONS_LEN", options_out_len + 4U <= DHCP_OPTIONS_LEN);
1531 options[options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24);
1532 options[options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16);
1533 options[options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8);
1534 options[options_out_len++] = (u8_t)((value & 0x000000ffUL));
1535 return options_out_len;
1536 }
1537
1538 #if LWIP_NETIF_HOSTNAME
1539 static u16_t
1540 dhcp_option_hostname(u16_t options_out_len, u8_t *options, struct netif *netif)
1541 {
1542 if (netif->hostname != NULL) {
1543 size_t namelen = strlen(netif->hostname);
1544 if (namelen > 0) {
1545 size_t len;
1546 const char *p = netif->hostname;
1547 /* Shrink len to available bytes (need 2 bytes for OPTION_HOSTNAME
1548 and 1 byte for trailer) */
1549 size_t available = DHCP_OPTIONS_LEN - options_out_len - 3;
1550 LWIP_ASSERT("DHCP: hostname is too long!", namelen <= available);
1551 len = LWIP_MIN(namelen, available);
1552 LWIP_ASSERT("DHCP: hostname is too long!", len <= 0xFF);
1553 options_out_len = dhcp_option(options_out_len, options, DHCP_OPTION_HOSTNAME, (u8_t)len);
1554 while (len--) {
1555 options_out_len = dhcp_option_byte(options_out_len, options, *p++);
1556 }
1557 }
1558 }
1559 return options_out_len;
1560 }
1561 #endif /* LWIP_NETIF_HOSTNAME */
1562
1563 /**
1564 * Extract the DHCP message and the DHCP options.
1565 *
1566 * Extract the DHCP message and the DHCP options, each into a contiguous
1567 * piece of memory. As a DHCP message is variable sized by its options,
1568 * and also allows overriding some fields for options, the easy approach
1569 * is to first unfold the options into a contiguous piece of memory, and
1570 * use that further on.
1571 *
1572 */
1573 static err_t
1574 dhcp_parse_reply(struct pbuf *p, struct dhcp *dhcp)
1575 {
1576 u8_t *options;
1577 u16_t offset;
1578 u16_t offset_max;
1579 u16_t options_offset;
1580 u16_t options_idx;
1581 u16_t options_idx_max;
1582 struct pbuf *q;
1583 int parse_file_as_options = 0;
1584 int parse_sname_as_options = 0;
1585 struct dhcp_msg *msg_in;
1586 #if LWIP_DHCP_BOOTP_FILE
1587 int file_overloaded = 0;
1588 #endif
1589
1590 LWIP_UNUSED_ARG(dhcp);
1591
1592 /* clear received options */
1593 dhcp_clear_all_options(dhcp);
1594 /* check that beginning of dhcp_msg (up to and including chaddr) is in first pbuf */
1595 if (p->len < DHCP_SNAME_OFS) {
1596 return ERR_BUF;
1597 }
1598 msg_in = (struct dhcp_msg *)p->payload;
1599 #if LWIP_DHCP_BOOTP_FILE
1600 /* clear boot file name */
1601 dhcp->boot_file_name[0] = 0;
1602 #endif /* LWIP_DHCP_BOOTP_FILE */
1603
1604 /* parse options */
1605
1606 /* start with options field */
1607 options_idx = DHCP_OPTIONS_OFS;
1608 /* parse options to the end of the received packet */
1609 options_idx_max = p->tot_len;
1610 again:
1611 q = p;
1612 options_offset = options_idx;
1613 while ((q != NULL) && (options_idx >= q->len)) {
1614 options_idx = (u16_t)(options_idx - q->len);
1615 options_idx_max = (u16_t)(options_idx_max - q->len);
1616 q = q->next;
1617 }
1618 if (q == NULL) {
1619 return ERR_BUF;
1620 }
1621 offset = options_idx;
1622 offset_max = options_idx_max;
1623 options = (u8_t *)q->payload;
1624 /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */
1625 while ((q != NULL) && (offset < offset_max) && (options[offset] != DHCP_OPTION_END)) {
1626 u8_t op = options[offset];
1627 u8_t len;
1628 u8_t decode_len = 0;
1629 int decode_idx = -1;
1630 u16_t val_offset = (u16_t)(offset + 2);
1631 if (val_offset < offset) {
1632 /* overflow */
1633 return ERR_BUF;
1634 }
1635 /* len byte might be in the next pbuf */
1636 if ((offset + 1) < q->len) {
1637 len = options[offset + 1];
1638 } else {
1639 len = (q->next != NULL ? ((u8_t *)q->next->payload)[0] : 0);
1640 }
1641 /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F, msg_offset, q->len)); */
1642 decode_len = len;
1643 switch (op) {
1644 /* case(DHCP_OPTION_END): handled above */
1645 case (DHCP_OPTION_PAD):
1646 /* special option: no len encoded */
1647 decode_len = len = 0;
1648 /* will be increased below */
1649 break;
1650 case (DHCP_OPTION_SUBNET_MASK):
1651 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1652 decode_idx = DHCP_OPTION_IDX_SUBNET_MASK;
1653 break;
1654 case (DHCP_OPTION_ROUTER):
1655 decode_len = 4; /* only copy the first given router */
1656 LWIP_DHCP_INPUT_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;);
1657 decode_idx = DHCP_OPTION_IDX_ROUTER;
1658 break;
1659 #if LWIP_DHCP_PROVIDE_DNS_SERVERS
1660 case (DHCP_OPTION_DNS_SERVER):
1661 /* special case: there might be more than one server */
1662 LWIP_DHCP_INPUT_ERROR("len %% 4 == 0", len % 4 == 0, return ERR_VAL;);
1663 /* limit number of DNS servers */
1664 decode_len = LWIP_MIN(len, 4 * DNS_MAX_SERVERS);
1665 LWIP_DHCP_INPUT_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;);
1666 decode_idx = DHCP_OPTION_IDX_DNS_SERVER;
1667 break;
1668 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */
1669 case (DHCP_OPTION_LEASE_TIME):
1670 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1671 decode_idx = DHCP_OPTION_IDX_LEASE_TIME;
1672 break;
1673 #if LWIP_DHCP_GET_NTP_SRV
1674 case (DHCP_OPTION_NTP):
1675 /* special case: there might be more than one server */
1676 LWIP_DHCP_INPUT_ERROR("len %% 4 == 0", len % 4 == 0, return ERR_VAL;);
1677 /* limit number of NTP servers */
1678 decode_len = LWIP_MIN(len, 4 * LWIP_DHCP_MAX_NTP_SERVERS);
1679 LWIP_DHCP_INPUT_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;);
1680 decode_idx = DHCP_OPTION_IDX_NTP_SERVER;
1681 break;
1682 #endif /* LWIP_DHCP_GET_NTP_SRV*/
1683 case (DHCP_OPTION_OVERLOAD):
1684 LWIP_DHCP_INPUT_ERROR("len == 1", len == 1, return ERR_VAL;);
1685 /* decode overload only in options, not in file/sname: invalid packet */
1686 LWIP_DHCP_INPUT_ERROR("overload in file/sname", options_offset == DHCP_OPTIONS_OFS, return ERR_VAL;);
1687 decode_idx = DHCP_OPTION_IDX_OVERLOAD;
1688 break;
1689 case (DHCP_OPTION_MESSAGE_TYPE):
1690 LWIP_DHCP_INPUT_ERROR("len == 1", len == 1, return ERR_VAL;);
1691 decode_idx = DHCP_OPTION_IDX_MSG_TYPE;
1692 break;
1693 case (DHCP_OPTION_SERVER_ID):
1694 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1695 decode_idx = DHCP_OPTION_IDX_SERVER_ID;
1696 break;
1697 case (DHCP_OPTION_T1):
1698 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1699 decode_idx = DHCP_OPTION_IDX_T1;
1700 break;
1701 case (DHCP_OPTION_T2):
1702 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1703 decode_idx = DHCP_OPTION_IDX_T2;
1704 break;
1705 default:
1706 decode_len = 0;
1707 LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", (u16_t)op));
1708 LWIP_HOOK_DHCP_PARSE_OPTION(ip_current_netif(), dhcp, dhcp->state, msg_in,
1709 dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) ? (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) : 0,
1710 op, len, q, val_offset);
1711 break;
1712 }
1713 if (op == DHCP_OPTION_PAD) {
1714 offset++;
1715 } else {
1716 if (offset + len + 2 > 0xFFFF) {
1717 /* overflow */
1718 return ERR_BUF;
1719 }
1720 offset = (u16_t)(offset + len + 2);
1721 if (decode_len > 0) {
1722 u32_t value = 0;
1723 u16_t copy_len;
1724 decode_next:
1725 LWIP_ASSERT("check decode_idx", decode_idx >= 0 && decode_idx < DHCP_OPTION_IDX_MAX);
1726 if (!dhcp_option_given(dhcp, decode_idx)) {
1727 copy_len = LWIP_MIN(decode_len, 4);
1728 if (pbuf_copy_partial(q, &value, copy_len, val_offset) != copy_len) {
1729 return ERR_BUF;
1730 }
1731 if (decode_len > 4) {
1732 /* decode more than one u32_t */
1733 u16_t next_val_offset;
1734 LWIP_DHCP_INPUT_ERROR("decode_len %% 4 == 0", decode_len % 4 == 0, return ERR_VAL;);
1735 dhcp_got_option(dhcp, decode_idx);
1736 dhcp_set_option_value(dhcp, decode_idx, lwip_htonl(value));
1737 decode_len = (u8_t)(decode_len - 4);
1738 next_val_offset = (u16_t)(val_offset + 4);
1739 if (next_val_offset < val_offset) {
1740 /* overflow */
1741 return ERR_BUF;
1742 }
1743 val_offset = next_val_offset;
1744 decode_idx++;
1745 goto decode_next;
1746 } else if (decode_len == 4) {
1747 value = lwip_ntohl(value);
1748 } else {
1749 LWIP_DHCP_INPUT_ERROR("invalid decode_len", decode_len == 1, return ERR_VAL;);
1750 value = ((u8_t *)&value)[0];
1751 }
1752 dhcp_got_option(dhcp, decode_idx);
1753 dhcp_set_option_value(dhcp, decode_idx, value);
1754 }
1755 }
1756 }
1757 if (offset >= q->len) {
1758 offset = (u16_t)(offset - q->len);
1759 offset_max = (u16_t)(offset_max - q->len);
1760 if (offset < offset_max) {
1761 q = q->next;
1762 LWIP_DHCP_INPUT_ERROR("next pbuf was null", q != NULL, return ERR_VAL;);
1763 options = (u8_t *)q->payload;
1764 } else {
1765 /* We've run out of bytes, probably no end marker. Don't proceed. */
1766 return ERR_BUF;
1767 }
1768 }
1769 }
1770 /* is this an overloaded message? */
1771 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_OVERLOAD)) {
1772 u32_t overload = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_OVERLOAD);
1773 dhcp_clear_option(dhcp, DHCP_OPTION_IDX_OVERLOAD);
1774 if (overload == DHCP_OVERLOAD_FILE) {
1775 parse_file_as_options = 1;
1776 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded file field\n"));
1777 } else if (overload == DHCP_OVERLOAD_SNAME) {
1778 parse_sname_as_options = 1;
1779 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname field\n"));
1780 } else if (overload == DHCP_OVERLOAD_SNAME_FILE) {
1781 parse_sname_as_options = 1;
1782 parse_file_as_options = 1;
1783 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname and file field\n"));
1784 } else {
1785 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("invalid overload option: %d\n", (int)overload));
1786 }
1787 }
1788 if (parse_file_as_options) {
1789 /* if both are overloaded, parse file first and then sname (RFC 2131 ch. 4.1) */
1790 parse_file_as_options = 0;
1791 options_idx = DHCP_FILE_OFS;
1792 options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN;
1793 #if LWIP_DHCP_BOOTP_FILE
1794 file_overloaded = 1;
1795 #endif
1796 goto again;
1797 } else if (parse_sname_as_options) {
1798 parse_sname_as_options = 0;
1799 options_idx = DHCP_SNAME_OFS;
1800 options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN;
1801 goto again;
1802 }
1803 #if LWIP_DHCP_BOOTP_FILE
1804 if (!file_overloaded) {
1805 /* only do this for ACK messages */
1806 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) &&
1807 (dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK))
1808 /* copy bootp file name, don't care for sname (server hostname) */
1809 if (pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS) != (DHCP_FILE_LEN-1)) {
1810 return ERR_BUF;
1811 }
1812 /* make sure the string is really NULL-terminated */
1813 dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0;
1814 }
1815 #endif /* LWIP_DHCP_BOOTP_FILE */
1816 return ERR_OK;
1817 }
1818
1819 /**
1820 * If an incoming DHCP message is in response to us, then trigger the state machine
1821 */
1822 static void
1823 dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port)
1824 {
1825 struct netif *netif = ip_current_input_netif();
1826 struct dhcp *dhcp = netif_dhcp_data(netif);
1827 struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload;
1828 u8_t msg_type;
1829 u8_t i;
1830 struct dhcp_msg *msg_in;
1831
1832 LWIP_UNUSED_ARG(arg);
1833
1834 /* Caught DHCP message from netif that does not have DHCP enabled? -> not interested */
1835 if ((dhcp == NULL) || (dhcp->pcb_allocated == 0)) {
1836 goto free_pbuf_and_return;
1837 }
1838
1839 LWIP_ASSERT("invalid server address type", IP_IS_V4(addr));
1840
1841 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,
1842 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));
1843 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len));
1844 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len));
1845 /* prevent warnings about unused arguments */
1846 LWIP_UNUSED_ARG(pcb);
1847 LWIP_UNUSED_ARG(addr);
1848 LWIP_UNUSED_ARG(port);
1849
1850 if (p->len < DHCP_MIN_REPLY_LEN) {
1851 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP reply message or pbuf too short\n"));
1852 goto free_pbuf_and_return;
1853 }
1854
1855 if (reply_msg->op != DHCP_BOOTREPLY) {
1856 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));
1857 goto free_pbuf_and_return;
1858 }
1859 /* iterate through hardware address and match against DHCP message */
1860 for (i = 0; i < netif->hwaddr_len && i < LWIP_MIN(DHCP_CHADDR_LEN, NETIF_MAX_HWADDR_LEN); i++) {
1861 if (netif->hwaddr[i] != reply_msg->chaddr[i]) {
1862 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
1863 ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n",
1864 (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i]));
1865 goto free_pbuf_and_return;
1866 }
1867 }
1868 /* match transaction ID against what we expected */
1869 if (lwip_ntohl(reply_msg->xid) != dhcp->xid) {
1870 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
1871 ("transaction id mismatch reply_msg->xid(%"X32_F")!=dhcp->xid(%"X32_F")\n", lwip_ntohl(reply_msg->xid), dhcp->xid));
1872 goto free_pbuf_and_return;
1873 }
1874 /* option fields could be unfold? */
1875 if (dhcp_parse_reply(p, dhcp) != ERR_OK) {
1876 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
1877 ("problem unfolding DHCP message - too short on memory?\n"));
1878 goto free_pbuf_and_return;
1879 }
1880
1881 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n"));
1882 /* obtain pointer to DHCP message type */
1883 if (!dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE)) {
1884 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP_OPTION_MESSAGE_TYPE option not found\n"));
1885 goto free_pbuf_and_return;
1886 }
1887
1888 msg_in = (struct dhcp_msg *)p->payload;
1889 /* read DHCP message type */
1890 msg_type = (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE);
1891 /* message type is DHCP ACK? */
1892 if (msg_type == DHCP_ACK) {
1893 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_ACK received\n"));
1894 /* in requesting state? */
1895 if (dhcp->state == DHCP_STATE_REQUESTING) {
1896 dhcp_handle_ack(netif, msg_in);
1897 #if DHCP_DOES_ARP_CHECK
1898 if ((netif->flags & NETIF_FLAG_ETHARP) != 0) {
1899 /* check if the acknowledged lease address is already in use */
1900 dhcp_check(netif);
1901 } else {
1902 /* bind interface to the acknowledged lease address */
1903 dhcp_bind(netif);
1904 }
1905 #else
1906 /* bind interface to the acknowledged lease address */
1907 dhcp_bind(netif);
1908 #endif
1909 }
1910 /* already bound to the given lease address? */
1911 else if ((dhcp->state == DHCP_STATE_REBOOTING) || (dhcp->state == DHCP_STATE_REBINDING) ||
1912 (dhcp->state == DHCP_STATE_RENEWING)) {
1913 dhcp_handle_ack(netif, msg_in);
1914 dhcp_bind(netif);
1915 }
1916 }
1917 /* received a DHCP_NAK in appropriate state? */
1918 else if ((msg_type == DHCP_NAK) &&
1919 ((dhcp->state == DHCP_STATE_REBOOTING) || (dhcp->state == DHCP_STATE_REQUESTING) ||
1920 (dhcp->state == DHCP_STATE_REBINDING) || (dhcp->state == DHCP_STATE_RENEWING ))) {
1921 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_NAK received\n"));
1922 dhcp_handle_nak(netif);
1923 }
1924 /* received a DHCP_OFFER in DHCP_STATE_SELECTING state? */
1925 else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_STATE_SELECTING)) {
1926 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_OFFER received in DHCP_STATE_SELECTING state\n"));
1927 /* remember offered lease */
1928 dhcp_handle_offer(netif, msg_in);
1929 }
1930
1931 free_pbuf_and_return:
1932 pbuf_free(p);
1933 }
1934
1935 /**
1936 * Create a DHCP request, fill in common headers
1937 *
1938 * @param netif the netif under DHCP control
1939 * @param dhcp dhcp control struct
1940 * @param message_type message type of the request
1941 */
1942 static struct pbuf *
1943 dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type, u16_t *options_out_len)
1944 {
1945 u16_t i;
1946 struct pbuf *p_out;
1947 struct dhcp_msg *msg_out;
1948 u16_t options_out_len_loc;
1949
1950 #ifndef DHCP_GLOBAL_XID
1951 /** default global transaction identifier starting value (easy to match
1952 * with a packet analyser). We simply increment for each new request.
1953 * Predefine DHCP_GLOBAL_XID to a better value or a function call to generate one
1954 * at runtime, any supporting function prototypes can be defined in DHCP_GLOBAL_XID_HEADER */
1955 #if DHCP_CREATE_RAND_XID && defined(LWIP_RAND)
1956 static u32_t xid;
1957 #else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1958 static u32_t xid = 0xABCD0000;
1959 #endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1960 #else
1961 if (!xid_initialised) {
1962 xid = DHCP_GLOBAL_XID;
1963 xid_initialised = !xid_initialised;
1964 }
1965 #endif
1966 LWIP_ERROR("dhcp_create_msg: netif != NULL", (netif != NULL), return NULL;);
1967 LWIP_ERROR("dhcp_create_msg: dhcp != NULL", (dhcp != NULL), return NULL;);
1968 p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM);
1969 if (p_out == NULL) {
1970 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
1971 ("dhcp_create_msg(): could not allocate pbuf\n"));
1972 return NULL;
1973 }
1974 LWIP_ASSERT("dhcp_create_msg: check that first pbuf can hold struct dhcp_msg",
1975 (p_out->len >= sizeof(struct dhcp_msg)));
1976
1977 /* DHCP_REQUEST should reuse 'xid' from DHCPOFFER */
1978 if ((message_type != DHCP_REQUEST) || (dhcp->state == DHCP_STATE_REBOOTING)) {
1979 /* reuse transaction identifier in retransmissions */
1980 if (dhcp->tries == 0) {
1981 #if DHCP_CREATE_RAND_XID && defined(LWIP_RAND)
1982 xid = LWIP_RAND();
1983 #else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1984 xid++;
1985 #endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1986 }
1987 dhcp->xid = xid;
1988 }
1989 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE,
1990 ("transaction id xid(%"X32_F")\n", xid));
1991
1992 msg_out = (struct dhcp_msg *)p_out->payload;
1993 memset(msg_out, 0, sizeof(struct dhcp_msg));
1994
1995 msg_out->op = DHCP_BOOTREQUEST;
1996 /* @todo: make link layer independent */
1997 msg_out->htype = LWIP_IANA_HWTYPE_ETHERNET;
1998 msg_out->hlen = netif->hwaddr_len;
1999 msg_out->xid = lwip_htonl(dhcp->xid);
2000 /* we don't need the broadcast flag since we can receive unicast traffic
2001 before being fully configured! */
2002 /* set ciaddr to netif->ip_addr based on message_type and state */
2003 if ((message_type == DHCP_INFORM) || (message_type == DHCP_DECLINE) || (message_type == DHCP_RELEASE) ||
2004 ((message_type == DHCP_REQUEST) && /* DHCP_STATE_BOUND not used for sending! */
2005 ((dhcp->state == DHCP_STATE_RENEWING) || dhcp->state == DHCP_STATE_REBINDING))) {
2006 ip4_addr_copy(msg_out->ciaddr, *netif_ip4_addr(netif));
2007 }
2008 for (i = 0; i < LWIP_MIN(DHCP_CHADDR_LEN, NETIF_MAX_HWADDR_LEN); i++) {
2009 /* copy netif hardware address (padded with zeroes through memset already) */
2010 msg_out->chaddr[i] = netif->hwaddr[i];
2011 }
2012 msg_out->cookie = PP_HTONL(DHCP_MAGIC_COOKIE);
2013 /* Add option MESSAGE_TYPE */
2014 options_out_len_loc = dhcp_option(0, msg_out->options, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
2015 options_out_len_loc = dhcp_option_byte(options_out_len_loc, msg_out->options, message_type);
2016 if (options_out_len) {
2017 *options_out_len = options_out_len_loc;
2018 }
2019 return p_out;
2020 }
2021
2022 /**
2023 * Add a DHCP message trailer
2024 *
2025 * Adds the END option to the DHCP message, and if
2026 * necessary, up to three padding bytes.
2027 */
2028 static void
2029 dhcp_option_trailer(u16_t options_out_len, u8_t *options, struct pbuf *p_out)
2030 {
2031 options[options_out_len++] = DHCP_OPTION_END;
2032 /* packet is too small, or not 4 byte aligned? */
2033 while (((options_out_len < DHCP_MIN_OPTIONS_LEN) || (options_out_len & 3)) &&
2034 (options_out_len < DHCP_OPTIONS_LEN)) {
2035 /* add a fill/padding byte */
2036 options[options_out_len++] = 0;
2037 }
2038 /* shrink the pbuf to the actual content length */
2039 pbuf_realloc(p_out, (u16_t)(sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + options_out_len));
2040 }
2041
2042 /** check if DHCP supplied netif->ip_addr
2043 *
2044 * @param netif the netif to check
2045 * @return 1 if DHCP supplied netif->ip_addr (states BOUND or RENEWING),
2046 * 0 otherwise
2047 */
2048 u8_t
2049 dhcp_supplied_address(const struct netif *netif)
2050 {
2051 if ((netif != NULL) && (netif_dhcp_data(netif) != NULL)) {
2052 struct dhcp *dhcp = netif_dhcp_data(netif);
2053 return (dhcp->state == DHCP_STATE_BOUND) || (dhcp->state == DHCP_STATE_RENEWING) ||
2054 (dhcp->state == DHCP_STATE_REBINDING);
2055 }
2056 return 0;
2057 }
2058
2059 #endif /* LWIP_IPV4 && LWIP_DHCP */
2060