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/acd.h"
79 #include "lwip/dns.h"
80 #include "lwip/etharp.h"
81 #include "lwip/prot/dhcp.h"
82 #include "lwip/prot/iana.h"
83
84 #include <string.h>
85
86 #ifdef LWIP_HOOK_FILENAME
87 #include LWIP_HOOK_FILENAME
88 #endif
89 #ifndef LWIP_HOOK_DHCP_APPEND_OPTIONS
90 #define LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, state, msg, msg_type, options_len_ptr)
91 #endif
92 #ifndef LWIP_HOOK_DHCP_PARSE_OPTION
93 #define LWIP_HOOK_DHCP_PARSE_OPTION(netif, dhcp, state, msg, msg_type, option, len, pbuf, offset) do { LWIP_UNUSED_ARG(msg); } while(0)
94 #endif
95
96 /** DHCP_ADD_EXTRA_REQUEST_OPTIONS: Additional options added to the list of options
97 * that the client requests from the servers (opt 55: DHCP_OPTION_PARAMETER_REQUEST_LIST)
98 * If additional options are requested, define this macro as a comma separated list, with leading comma.
99 * This macro is useful for example when requested vendor specific ids (VCI/VSI options), here is an example
100 * of requesting the VSI option (option 43) (yes, the notation is a bit strange, but it works :)
101 * (NOTE: the space between # and define is required because of doxygen...)
102 * # define DHCP_ADD_EXTRA_REQUEST_OPTIONS ,43
103 */
104 #ifndef DHCP_ADD_EXTRA_REQUEST_OPTIONS
105 #define DHCP_ADD_EXTRA_REQUEST_OPTIONS
106 #endif
107
108 /** DHCP_DEFINE_CUSTOM_TIMEOUTS: if this is defined then you can customize various DHCP timeouts using these macros:
109 - DHCP_SET_TIMEOUT_FROM_OFFERED_T0_LEASE() to adjust the t0 lease timeout from the offered value
110 - DHCP_SET_TIMEOUT_FROM_OFFERED_T1_RENEW() same for t1 renew
111 - DHCP_SET_TIMEOUT_FROM_OFFERED_T2_REBIND() same for t2 rebind
112 - DHCP_NEXT_TIMEOUT_THRESHOLD to adjust the period of the next timeout
113 - DHCP_REQUEST_BACKOFF_SEQUENCE to adjust back-off times based on DHCP request attempts
114 */
115 #ifndef DHCP_DEFINE_CUSTOM_TIMEOUTS
116 #define SET_TIMEOUT_FROM_OFFERED(result, offered, min, max) do { \
117 u32_t timeout = (offered + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; \
118 if (timeout > max) { \
119 timeout = max; \
120 } \
121 if (timeout == min) { \
122 timeout = 1; \
123 } \
124 result = (dhcp_timeout_t)timeout; \
125 } while(0)
126
127 #define DHCP_SET_TIMEOUT_FROM_OFFERED_T0_LEASE(res, dhcp) SET_TIMEOUT_FROM_OFFERED(res, (dhcp)->offered_t0_lease, 0, 0xffff)
128 #define DHCP_SET_TIMEOUT_FROM_OFFERED_T1_RENEW(res, dhcp) SET_TIMEOUT_FROM_OFFERED(res, (dhcp)->offered_t1_renew, 0, 0xffff)
129 #define DHCP_SET_TIMEOUT_FROM_OFFERED_T2_REBIND(res, dhcp) SET_TIMEOUT_FROM_OFFERED(res, (dhcp)->offered_t2_rebind, 0, 0xffff)
130
131 #define DHCP_NEXT_TIMEOUT_THRESHOLD ((60 + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS)
132 #define DHCP_REQUEST_BACKOFF_SEQUENCE(tries) (u16_t)(( (tries) < 6 ? 1 << (tries) : 60) * 1000)
133
134 #endif /* DHCP_DEFINE_CUSTOM_TIMEOUTS */
135
136 /** DHCP_CREATE_RAND_XID: if this is set to 1, the xid is created using
137 * LWIP_RAND() (this overrides DHCP_GLOBAL_XID)
138 */
139 #ifndef DHCP_CREATE_RAND_XID
140 #define DHCP_CREATE_RAND_XID 1
141 #endif
142
143 /** Default for DHCP_GLOBAL_XID is 0xABCD0000
144 * This can be changed by defining DHCP_GLOBAL_XID and DHCP_GLOBAL_XID_HEADER, e.g.
145 * \#define DHCP_GLOBAL_XID_HEADER "stdlib.h"
146 * \#define DHCP_GLOBAL_XID rand()
147 */
148 #ifdef DHCP_GLOBAL_XID_HEADER
149 #include DHCP_GLOBAL_XID_HEADER /* include optional starting XID generation prototypes */
150 #endif
151
152 /** DHCP_OPTION_MAX_MSG_SIZE is set to the MTU
153 * MTU is checked to be big enough in dhcp_start */
154 #define DHCP_MAX_MSG_LEN(netif) (netif->mtu)
155 #define DHCP_MAX_MSG_LEN_MIN_REQUIRED 576
156 /** Minimum length for reply before packet is parsed */
157 #define DHCP_MIN_REPLY_LEN 44
158
159 #define REBOOT_TRIES 2
160 #if 0 /* The following codes are moved to dhcp.h for fixing it's todo, kept here just for notice */
161 #if LWIP_DNS && LWIP_DHCP_MAX_DNS_SERVERS
162 #if DNS_MAX_SERVERS > LWIP_DHCP_MAX_DNS_SERVERS
163 #define LWIP_DHCP_PROVIDE_DNS_SERVERS LWIP_DHCP_MAX_DNS_SERVERS
164 #else
165 #define LWIP_DHCP_PROVIDE_DNS_SERVERS DNS_MAX_SERVERS
166 #endif
167 #else
168 #define LWIP_DHCP_PROVIDE_DNS_SERVERS 0
169 #endif
170 #endif /* 0 */
171
172 #ifndef LWIP_DHCP_INPUT_ERROR
173 #define LWIP_DHCP_INPUT_ERROR(message, expression, handler) do { if (!(expression)) { \
174 handler;} } while(0)
175 #endif
176
177 #if 0
178 /** Option handling: options are parsed in dhcp_parse_reply
179 * and saved in an array where other functions can load them from.
180 * This might be moved into the struct dhcp (not necessarily since
181 * lwIP is single-threaded and the array is only used while in recv
182 * callback). */
183 enum dhcp_option_idx {
184 DHCP_OPTION_IDX_OVERLOAD = 0,
185 DHCP_OPTION_IDX_MSG_TYPE,
186 DHCP_OPTION_IDX_SERVER_ID,
187 DHCP_OPTION_IDX_LEASE_TIME,
188 DHCP_OPTION_IDX_T1,
189 DHCP_OPTION_IDX_T2,
190 DHCP_OPTION_IDX_SUBNET_MASK,
191 DHCP_OPTION_IDX_ROUTER,
192 #if LWIP_DHCP_PROVIDE_DNS_SERVERS
193 DHCP_OPTION_IDX_DNS_SERVER,
194 DHCP_OPTION_IDX_DNS_SERVER_LAST = DHCP_OPTION_IDX_DNS_SERVER + LWIP_DHCP_PROVIDE_DNS_SERVERS - 1,
195 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */
196 #if LWIP_DHCP_GET_NTP_SRV
197 DHCP_OPTION_IDX_NTP_SERVER,
198 DHCP_OPTION_IDX_NTP_SERVER_LAST = DHCP_OPTION_IDX_NTP_SERVER + LWIP_DHCP_MAX_NTP_SERVERS - 1,
199 #endif /* LWIP_DHCP_GET_NTP_SRV */
200 DHCP_OPTION_IDX_MAX
201 };
202
203 /** Holds the decoded option values, only valid while in dhcp_recv.
204 @todo: move this into struct dhcp? */
205 static u32_t dhcp_rx_options_val[DHCP_OPTION_IDX_MAX];
206 /** Holds a flag which option was received and is contained in dhcp_rx_options_val,
207 only valid while in dhcp_recv.
208 @todo: move this into struct dhcp? */
209 static u8_t dhcp_rx_options_given[DHCP_OPTION_IDX_MAX];
210 #endif /* 0 */
211 static u8_t dhcp_discover_request_options[] = {
212 DHCP_OPTION_SUBNET_MASK,
213 DHCP_OPTION_ROUTER,
214 DHCP_OPTION_BROADCAST
215 #if LWIP_DHCP_PROVIDE_DNS_SERVERS
216 , DHCP_OPTION_DNS_SERVER
217 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */
218 #if LWIP_DHCP_GET_NTP_SRV
219 , DHCP_OPTION_NTP
220 #endif /* LWIP_DHCP_GET_NTP_SRV */
221 DHCP_ADD_EXTRA_REQUEST_OPTIONS
222 };
223
224 #ifdef DHCP_GLOBAL_XID
225 static u32_t xid;
226 static u8_t xid_initialised;
227 #endif /* DHCP_GLOBAL_XID */
228
229 #define dhcp_option_given(dhcp, idx) ((dhcp)->rx_options_given[idx] != 0)
230 #define dhcp_got_option(dhcp, idx) ((dhcp)->rx_options_given[idx] = 1)
231 #define dhcp_clear_option(dhcp, idx) ((dhcp)->rx_options_given[idx] = 0)
232 #define dhcp_clear_all_options(dhcp) (memset((dhcp)->rx_options_given, 0, sizeof((dhcp)->rx_options_given)))
233 #define dhcp_get_option_value(dhcp, idx) ((dhcp)->rx_options_val[idx])
234 #define dhcp_set_option_value(dhcp, idx, val) ((dhcp)->rx_options_val[idx] = (val))
235
236 static struct udp_pcb *dhcp_pcb;
237 static u8_t dhcp_pcb_refcount;
238
239 /* DHCP client state machine functions */
240 static err_t dhcp_discover(struct netif *netif);
241 static err_t dhcp_select(struct netif *netif);
242 static void dhcp_bind(struct netif *netif);
243 #if LWIP_DHCP_DOES_ACD_CHECK
244 static err_t dhcp_decline(struct netif *netif);
245 #endif /* LWIP_DHCP_DOES_ACD_CHECK */
246 static err_t dhcp_rebind(struct netif *netif);
247 static err_t dhcp_reboot(struct netif *netif);
248 static void dhcp_set_state(struct dhcp *dhcp, u8_t new_state);
249
250 /* receive, unfold, parse and free incoming messages */
251 static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port);
252
253 /* set the DHCP timers */
254 static void dhcp_timeout(struct netif *netif);
255 static void dhcp_t1_timeout(struct netif *netif);
256 static void dhcp_t2_timeout(struct netif *netif);
257
258 /* build outgoing messages */
259 /* create a DHCP message, fill in common headers */
260 static struct pbuf *dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type, u16_t *options_out_len);
261 /* add a DHCP option (type, then length in bytes) */
262 static u16_t dhcp_option(u16_t options_out_len, u8_t *options, u8_t option_type, u8_t option_len);
263 /* add option values */
264 static u16_t dhcp_option_byte(u16_t options_out_len, u8_t *options, u8_t value);
265 static u16_t dhcp_option_short(u16_t options_out_len, u8_t *options, u16_t value);
266 static u16_t dhcp_option_long(u16_t options_out_len, u8_t *options, u32_t value);
267 #if LWIP_NETIF_HOSTNAME
268 static u16_t dhcp_option_hostname(u16_t options_out_len, u8_t *options, struct netif *netif);
269 #endif /* LWIP_NETIF_HOSTNAME */
270 /* always add the DHCP options trailer to end and pad */
271 static void dhcp_option_trailer(u16_t options_out_len, u8_t *options, struct pbuf *p_out);
272
273 /** Ensure DHCP PCB is allocated and bound */
274 static err_t
dhcp_inc_pcb_refcount(void)275 dhcp_inc_pcb_refcount(void)
276 {
277 if (dhcp_pcb_refcount == 0) {
278 LWIP_ASSERT("dhcp_inc_pcb_refcount(): memory leak", dhcp_pcb == NULL);
279
280 /* allocate UDP PCB */
281 dhcp_pcb = udp_new();
282
283 if (dhcp_pcb == NULL) {
284 return ERR_MEM;
285 }
286
287 ip_set_option(dhcp_pcb, SOF_BROADCAST);
288
289 /* set up local and remote port for the pcb -> listen on all interfaces on all src/dest IPs */
290 udp_bind(dhcp_pcb, IP4_ADDR_ANY, LWIP_IANA_PORT_DHCP_CLIENT);
291 udp_connect(dhcp_pcb, IP4_ADDR_ANY, LWIP_IANA_PORT_DHCP_SERVER);
292 udp_recv(dhcp_pcb, dhcp_recv, NULL);
293 }
294
295 dhcp_pcb_refcount++;
296
297 return ERR_OK;
298 }
299
300 /** Free DHCP PCB if the last netif stops using it */
301 static void
dhcp_dec_pcb_refcount(void)302 dhcp_dec_pcb_refcount(void)
303 {
304 LWIP_ASSERT("dhcp_pcb_refcount(): refcount error", (dhcp_pcb_refcount > 0));
305 dhcp_pcb_refcount--;
306
307 if (dhcp_pcb_refcount == 0) {
308 udp_remove(dhcp_pcb);
309 dhcp_pcb = NULL;
310 }
311 }
312
313 /**
314 * Back-off the DHCP client (because of a received NAK response).
315 *
316 * Back-off the DHCP client because of a received NAK. Receiving a
317 * NAK means the client asked for something non-sensible, for
318 * example when it tries to renew a lease obtained on another network.
319 *
320 * We clear any existing set IP address and restart DHCP negotiation
321 * afresh (as per RFC2131 3.2.3).
322 *
323 * @param netif the netif under DHCP control
324 */
325 static void
dhcp_handle_nak(struct netif * netif)326 dhcp_handle_nak(struct netif *netif)
327 {
328 struct dhcp *dhcp = netif_dhcp_data(netif);
329
330 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_nak(netif=%p) %c%c%"U16_F"\n",
331 (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num));
332 /* Change to a defined state - set this before assigning the address
333 to ensure the callback can use dhcp_supplied_address() */
334 dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF);
335 /* remove IP address from interface (must no longer be used, as per RFC2131) */
336 netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4);
337 /* We can immediately restart discovery */
338 dhcp_discover(netif);
339 }
340
341 #if LWIP_DHCP_DOES_ACD_CHECK
342 /**
343 * Handle conflict information from ACD module
344 *
345 * @param netif network interface to handle conflict information on
346 * @param state acd_callback_enum_t
347 */
348 static void
dhcp_conflict_callback(struct netif * netif,acd_callback_enum_t state)349 dhcp_conflict_callback(struct netif *netif, acd_callback_enum_t state)
350 {
351 struct dhcp *dhcp = netif_dhcp_data(netif);
352 u16_t msecs;
353
354 LWIP_ASSERT("DHCP should be enabled at this point, but it is not!",
355 (dhcp != NULL) && (dhcp->state != DHCP_STATE_OFF));
356
357 switch (state) {
358 case ACD_IP_OK:
359 dhcp_bind(netif);
360 break;
361 case ACD_RESTART_CLIENT:
362 /* wait 10s before restarting
363 * According to RFC2131 section 3.1 point 5:
364 * If the client detects that the address is already in use (e.g., through
365 * the use of ARP), the client MUST send a DHCPDECLINE message to the
366 * server and restarts the configuration process. The client SHOULD wait
367 * a minimum of ten seconds before restarting the configuration process to
368 * avoid excessive network traffic in case of looping. */
369 dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF);
370 msecs = 10 * 1000;
371 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
372 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs));
373 break;
374 case ACD_DECLINE:
375 /* remove IP address from interface
376 * (prevents routing from selecting this interface) */
377 netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4);
378 /* Let the DHCP server know we will not use the address */
379 dhcp_decline(netif);
380 break;
381 default:
382 break;
383 }
384 }
385
386 /**
387 * Checks if the offered IP address is already in use.
388 *
389 * It does this according to the address conflict detection method described in
390 * RFC5227.
391 *
392 * @param netif the netif under DHCP control
393 */
394 static void
dhcp_check(struct netif * netif)395 dhcp_check(struct netif *netif)
396 {
397 struct dhcp *dhcp = netif_dhcp_data(netif);
398
399 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_check(netif=%p) %c%c\n", (void *)netif, (s16_t)netif->name[0],
400 (s16_t)netif->name[1]));
401 dhcp_set_state(dhcp, DHCP_STATE_CHECKING);
402
403 /* start ACD module */
404 acd_start(netif, &dhcp->acd, dhcp->offered_ip_addr);
405 }
406 #endif /* LWIP_DHCP_DOES_ACD_CHECK */
407
408 /**
409 * Remember the configuration offered by a DHCP server.
410 *
411 * @param netif the netif under DHCP control
412 */
413 static void
dhcp_handle_offer(struct netif * netif,struct dhcp_msg * msg_in)414 dhcp_handle_offer(struct netif *netif, struct dhcp_msg *msg_in)
415 {
416 struct dhcp *dhcp = netif_dhcp_data(netif);
417
418 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_offer(netif=%p) %c%c%"U16_F"\n",
419 (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num));
420 /* obtain the server address */
421 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SERVER_ID)) {
422 dhcp->request_timeout = 0; /* stop timer */
423
424 ip_addr_set_ip4_u32(&dhcp->server_ip_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SERVER_ID)));
425 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): server 0x%08"X32_F"\n",
426 ip4_addr_get_u32(ip_2_ip4(&dhcp->server_ip_addr))));
427 /* remember offered address */
428 ip4_addr_copy(dhcp->offered_ip_addr, msg_in->yiaddr);
429 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): offer for 0x%08"X32_F"\n",
430 ip4_addr_get_u32(&dhcp->offered_ip_addr)));
431
432 dhcp_select(netif);
433 } else {
434 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
435 ("dhcp_handle_offer(netif=%p) did not get server ID!\n", (void *)netif));
436 }
437 }
438
439 /**
440 * Select a DHCP server offer out of all offers.
441 *
442 * Simply select the first offer received.
443 *
444 * @param netif the netif under DHCP control
445 * @return lwIP specific error (see error.h)
446 */
447 static err_t
dhcp_select(struct netif * netif)448 dhcp_select(struct netif *netif)
449 {
450 struct dhcp *dhcp;
451 err_t result;
452 u16_t msecs;
453 u8_t i;
454 struct pbuf *p_out;
455 u16_t options_out_len;
456
457 LWIP_ERROR("dhcp_select: netif != NULL", (netif != NULL), return ERR_ARG;);
458 dhcp = netif_dhcp_data(netif);
459 LWIP_ERROR("dhcp_select: dhcp != NULL", (dhcp != NULL), return ERR_VAL;);
460
461 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));
462 dhcp_set_state(dhcp, DHCP_STATE_REQUESTING);
463
464 /* create and initialize the DHCP message header */
465 p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len);
466 if (p_out != NULL) {
467 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
468 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
469 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
470
471 /* MUST request the offered IP address */
472 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_REQUESTED_IP, 4);
473 options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
474
475 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_SERVER_ID, 4);
476 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))));
477
478 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
479 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
480 options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);
481 }
482
483 #if LWIP_NETIF_HOSTNAME
484 options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif);
485 #endif /* LWIP_NETIF_HOSTNAME */
486
487 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_REQUESTING, msg_out, DHCP_REQUEST, &options_out_len);
488 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
489
490 /* send broadcast to any DHCP server */
491 result = udp_sendto_if_src(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif, IP4_ADDR_ANY);
492 pbuf_free(p_out);
493 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_select: REQUESTING\n"));
494 } else {
495 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_select: could not allocate DHCP request\n"));
496 result = ERR_MEM;
497 }
498 if (dhcp->tries < 255) {
499 dhcp->tries++;
500 }
501 msecs = (u16_t)((dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000);
502 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
503 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_select(): set request timeout %"U16_F" msecs\n", msecs));
504 return result;
505 }
506
507 /**
508 * The DHCP timer that checks for lease renewal/rebind timeouts.
509 * Must be called once a minute (see @ref DHCP_COARSE_TIMER_SECS).
510 */
511 void
dhcp_coarse_tmr(void)512 dhcp_coarse_tmr(void)
513 {
514 struct netif *netif;
515 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n"));
516 /* iterate through all network interfaces */
517 #ifdef LOSCFG_NET_CONTAINER
518 NETIF_FOREACH(netif, get_root_net_group()) {
519 #else
520 NETIF_FOREACH(netif) {
521 #endif
522 /* only act on DHCP configured interfaces */
523 struct dhcp *dhcp = netif_dhcp_data(netif);
524 if ((dhcp != NULL) && (dhcp->state != DHCP_STATE_OFF)) {
525 /* compare lease time to expire timeout */
526 if (dhcp->t0_timeout && (++dhcp->lease_used == dhcp->t0_timeout)) {
527 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t0 timeout\n"));
528 /* this clients' lease time has expired */
529 dhcp_release_and_stop(netif);
530 dhcp_start(netif);
531 /* timer is active (non zero), and triggers (zeroes) now? */
532 } else if (dhcp->t2_rebind_time && (dhcp->t2_rebind_time-- == 1)) {
533 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t2 timeout\n"));
534 /* this clients' rebind timeout triggered */
535 dhcp_t2_timeout(netif);
536 /* timer is active (non zero), and triggers (zeroes) now */
537 } else if (dhcp->t1_renew_time && (dhcp->t1_renew_time-- == 1)) {
538 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t1 timeout\n"));
539 /* this clients' renewal timeout triggered */
540 dhcp_t1_timeout(netif);
541 }
542 }
543 }
544 }
545
546 #if LWIP_LOWPOWER
547 #include "lwip/lowpower.h"
548
549 u32_t
550 dhcp_coarse_tmr_tick(void)
551 {
552 struct netif *netif;
553 u32_t tick = 0;
554 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n"));
555 /* iterate through all network interfaces */
556 #ifdef LOSCFG_NET_CONTAINER
557 NETIF_FOREACH(netif, get_root_net_group())
558 #else
559 NETIF_FOREACH(netif)
560 #endif
561 {
562 struct dhcp *dhcp = netif_dhcp_data(netif);
563 if ((dhcp != NULL) && (dhcp->state != DHCP_STATE_OFF)) {
564 if (dhcp->t0_timeout > 0) {
565 if (dhcp->t0_timeout > dhcp->lease_used) {
566 SET_TMR_TICK(tick, dhcp->t0_timeout - dhcp->lease_used);
567 } else {
568 SET_TMR_TICK(tick, 1);
569 }
570 }
571 if (dhcp->t2_rebind_time > 0) {
572 SET_TMR_TICK(tick, dhcp->t2_rebind_time);
573 }
574 if (dhcp->t1_renew_time > 0) {
575 SET_TMR_TICK(tick, dhcp->t1_renew_time);
576 }
577 }
578 }
579 return tick;
580 }
581
582 u32_t
583 dhcp_fine_tmr_tick(void)
584 {
585 struct netif *netif;
586 u32_t tick = 0;
587 /* loop through netif's */
588 #ifdef LOSCFG_NET_CONTAINER
589 NETIF_FOREACH(netif, get_root_net_group())
590 #else
591 NETIF_FOREACH(netif)
592 #endif
593 {
594 struct dhcp *dhcp = netif_dhcp_data(netif);
595 if (dhcp != NULL) {
596 if (dhcp->request_timeout > 0) {
597 SET_TMR_TICK(tick, dhcp->request_timeout);
598 }
599 }
600 }
601 return tick;
602 }
603 #endif /* LWIP_LOWPOWER */
604
605 /**
606 * DHCP transaction timeout handling (this function must be called every 500ms,
607 * see @ref DHCP_FINE_TIMER_MSECS).
608 *
609 * A DHCP server is expected to respond within a short period of time.
610 * This timer checks whether an outstanding DHCP request is timed out.
611 */
612 void
613 dhcp_fine_tmr(void)
614 {
615 struct netif *netif;
616 /* loop through netif's */
617 #ifdef LOSCFG_NET_CONTAINER
618 NETIF_FOREACH(netif, get_root_net_group()) {
619 #else
620 NETIF_FOREACH(netif) {
621 #endif
622 struct dhcp *dhcp = netif_dhcp_data(netif);
623 /* only act on DHCP configured interfaces */
624 if (dhcp != NULL) {
625 /* timer is active (non zero), and is about to trigger now */
626 if (dhcp->request_timeout > 1) {
627 dhcp->request_timeout--;
628 } else if (dhcp->request_timeout == 1) {
629 dhcp->request_timeout--;
630 /* { dhcp->request_timeout == 0 } */
631 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_fine_tmr(): request timeout\n"));
632 /* this client's request timeout triggered */
633 dhcp_timeout(netif);
634 }
635 }
636 }
637 }
638
639 /**
640 * A DHCP negotiation transaction, or ARP request, has timed out.
641 *
642 * The timer that was started with the DHCP or ARP request has
643 * timed out, indicating no response was received in time.
644 *
645 * @param netif the netif under DHCP control
646 */
647 static void
648 dhcp_timeout(struct netif *netif)
649 {
650 struct dhcp *dhcp = netif_dhcp_data(netif);
651
652 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout()\n"));
653 /* back-off period has passed, or server selection timed out */
654 if ((dhcp->state == DHCP_STATE_BACKING_OFF) || (dhcp->state == DHCP_STATE_SELECTING)) {
655 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout(): restarting discovery\n"));
656 dhcp_discover(netif);
657 /* receiving the requested lease timed out */
658 } else if (dhcp->state == DHCP_STATE_REQUESTING) {
659 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, DHCP request timed out\n"));
660 if (dhcp->tries <= 5) {
661 dhcp_select(netif);
662 } else {
663 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, releasing, restarting\n"));
664 dhcp_release_and_stop(netif);
665 dhcp_start(netif);
666 }
667 } else if (dhcp->state == DHCP_STATE_REBOOTING) {
668 if (dhcp->tries < REBOOT_TRIES) {
669 dhcp_reboot(netif);
670 } else {
671 dhcp_discover(netif);
672 }
673 }
674 }
675
676 /**
677 * The renewal period has timed out.
678 *
679 * @param netif the netif under DHCP control
680 */
681 static void
682 dhcp_t1_timeout(struct netif *netif)
683 {
684 struct dhcp *dhcp = netif_dhcp_data(netif);
685
686 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_t1_timeout()\n"));
687 if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_BOUND) ||
688 (dhcp->state == DHCP_STATE_RENEWING)) {
689 /* just retry to renew - note that the rebind timer (t2) will
690 * eventually time-out if renew tries fail. */
691 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
692 ("dhcp_t1_timeout(): must renew\n"));
693 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state
694 DHCP_STATE_RENEWING, not DHCP_STATE_BOUND */
695 dhcp_renew(netif);
696 /* Calculate next timeout */
697 if (((dhcp->t2_timeout - dhcp->lease_used) / 2) >= DHCP_NEXT_TIMEOUT_THRESHOLD) {
698 dhcp->t1_renew_time = (dhcp_timeout_t)((dhcp->t2_timeout - dhcp->lease_used) / 2);
699 }
700 }
701 }
702
703 /**
704 * The rebind period has timed out.
705 *
706 * @param netif the netif under DHCP control
707 */
708 static void
709 dhcp_t2_timeout(struct netif *netif)
710 {
711 struct dhcp *dhcp = netif_dhcp_data(netif);
712
713 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t2_timeout()\n"));
714 if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_BOUND) ||
715 (dhcp->state == DHCP_STATE_RENEWING) || (dhcp->state == DHCP_STATE_REBINDING)) {
716 /* just retry to rebind */
717 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
718 ("dhcp_t2_timeout(): must rebind\n"));
719 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state
720 DHCP_STATE_REBINDING, not DHCP_STATE_BOUND */
721 dhcp_rebind(netif);
722 /* Calculate next timeout */
723 if (((dhcp->t0_timeout - dhcp->lease_used) / 2) >= DHCP_NEXT_TIMEOUT_THRESHOLD) {
724 dhcp->t2_rebind_time = (dhcp_timeout_t)((dhcp->t0_timeout - dhcp->lease_used) / 2);
725 }
726 }
727 }
728
729 /**
730 * Handle a DHCP ACK packet
731 *
732 * @param netif the netif under DHCP control
733 */
734 static void
735 dhcp_handle_ack(struct netif *netif, struct dhcp_msg *msg_in)
736 {
737 struct dhcp *dhcp = netif_dhcp_data(netif);
738
739 #if LWIP_DHCP_PROVIDE_DNS_SERVERS || LWIP_DHCP_GET_NTP_SRV
740 u8_t n;
741 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS || LWIP_DHCP_GET_NTP_SRV */
742 #if LWIP_DHCP_GET_NTP_SRV
743 ip4_addr_t ntp_server_addrs[LWIP_DHCP_MAX_NTP_SERVERS];
744 #endif
745
746 /* clear options we might not get from the ACK */
747 ip4_addr_set_zero(&dhcp->offered_sn_mask);
748 ip4_addr_set_zero(&dhcp->offered_gw_addr);
749 #if LWIP_DHCP_BOOTP_FILE
750 ip4_addr_set_zero(&dhcp->offered_si_addr);
751 #endif /* LWIP_DHCP_BOOTP_FILE */
752
753 /* lease time given? */
754 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_LEASE_TIME)) {
755 /* remember offered lease time */
756 dhcp->offered_t0_lease = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_LEASE_TIME);
757 }
758 /* renewal period given? */
759 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T1)) {
760 /* remember given renewal period */
761 dhcp->offered_t1_renew = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T1);
762 } else {
763 /* calculate safe periods for renewal */
764 dhcp->offered_t1_renew = dhcp->offered_t0_lease / 2;
765 }
766
767 /* renewal period given? */
768 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T2)) {
769 /* remember given rebind period */
770 dhcp->offered_t2_rebind = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T2);
771 } else {
772 /* calculate safe periods for rebinding (offered_t0_lease * 0.875 -> 87.5%)*/
773 dhcp->offered_t2_rebind = (dhcp->offered_t0_lease * 7U) / 8U;
774 }
775
776 /* (y)our internet address */
777 ip4_addr_copy(dhcp->offered_ip_addr, msg_in->yiaddr);
778
779 #if LWIP_DHCP_BOOTP_FILE
780 /* copy boot server address,
781 boot file name copied in dhcp_parse_reply if not overloaded */
782 ip4_addr_copy(dhcp->offered_si_addr, msg_in->siaddr);
783 #endif /* LWIP_DHCP_BOOTP_FILE */
784
785 /* subnet mask given? */
786 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)) {
787 /* remember given subnet mask */
788 ip4_addr_set_u32(&dhcp->offered_sn_mask, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)));
789 dhcp->flags |= DHCP_FLAG_SUBNET_MASK_GIVEN;
790 } else {
791 dhcp->flags &= ~DHCP_FLAG_SUBNET_MASK_GIVEN;
792 }
793
794 /* gateway router */
795 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_ROUTER)) {
796 ip4_addr_set_u32(&dhcp->offered_gw_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_ROUTER)));
797 }
798
799 #if LWIP_DHCP_GET_NTP_SRV
800 /* NTP servers */
801 for (n = 0; (n < LWIP_DHCP_MAX_NTP_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_NTP_SERVER + n); n++) {
802 ip4_addr_set_u32(&ntp_server_addrs[n], lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_NTP_SERVER + n)));
803 }
804 dhcp_set_ntp_servers(n, ntp_server_addrs);
805 #endif /* LWIP_DHCP_GET_NTP_SRV */
806
807 #if LWIP_DHCP_PROVIDE_DNS_SERVERS
808 /* DNS servers */
809 for (n = 0; (n < LWIP_DHCP_PROVIDE_DNS_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n); n++) {
810 ip_addr_t dns_addr;
811 ip_addr_set_ip4_u32_val(dns_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n)));
812 dns_setserver(n, &dns_addr);
813 }
814 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */
815 }
816
817 /**
818 * @ingroup dhcp4
819 * Set a statically allocated struct dhcp to work with.
820 * Using this prevents dhcp_start to allocate it using mem_malloc.
821 *
822 * @param netif the netif for which to set the struct dhcp
823 * @param dhcp (uninitialised) dhcp struct allocated by the application
824 */
825 void
826 dhcp_set_struct(struct netif *netif, struct dhcp *dhcp)
827 {
828 LWIP_ASSERT_CORE_LOCKED();
829 LWIP_ASSERT("netif != NULL", netif != NULL);
830 LWIP_ASSERT("dhcp != NULL", dhcp != NULL);
831 LWIP_ASSERT("netif already has a struct dhcp set", netif_dhcp_data(netif) == NULL);
832
833 /* clear data structure */
834 memset(dhcp, 0, sizeof(struct dhcp));
835 /* mark this as externally allocated */
836 dhcp->flags |= DHCP_FLAG_EXTERNAL_MEM;
837 /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */
838 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp);
839 }
840
841 /**
842 * @ingroup dhcp4
843 * Removes a struct dhcp from a netif.
844 *
845 * ATTENTION: Only use this when not using dhcp_set_struct() to allocate the
846 * struct dhcp since the memory is passed back to the heap.
847 *
848 * @param netif the netif from which to remove the struct dhcp
849 */
850 void dhcp_cleanup(struct netif *netif)
851 {
852 struct dhcp *dhcp;
853 LWIP_ASSERT_CORE_LOCKED();
854 LWIP_ASSERT("netif != NULL", netif != NULL);
855
856 dhcp = netif_dhcp_data(netif);
857 if (dhcp != NULL) {
858 if (!(dhcp->flags & DHCP_FLAG_EXTERNAL_MEM)) {
859 mem_free(dhcp);
860 }
861 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, NULL);
862 }
863 }
864
865 /**
866 * @ingroup dhcp4
867 * Start DHCP negotiation for a network interface.
868 *
869 * If no DHCP client instance was attached to this interface,
870 * a new client is created first. If a DHCP client instance
871 * was already present, it restarts negotiation.
872 *
873 * @param netif The lwIP network interface
874 * @return lwIP error code
875 * - ERR_OK - No error
876 * - ERR_MEM - Out of memory
877 */
878 err_t
879 dhcp_start(struct netif *netif)
880 {
881 struct dhcp *dhcp;
882 err_t result;
883
884 LWIP_ASSERT_CORE_LOCKED();
885 LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;);
886 LWIP_ERROR("netif is not up, old style port?", netif_is_up(netif), return ERR_ARG;);
887 dhcp = netif_dhcp_data(netif);
888 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));
889
890 /* check MTU of the netif */
891 if (netif->mtu < DHCP_MAX_MSG_LEN_MIN_REQUIRED) {
892 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): Cannot use this netif with DHCP: MTU is too small\n"));
893 return ERR_MEM;
894 }
895
896 /* no DHCP client attached yet? */
897 if (dhcp == NULL) {
898 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): mallocing new DHCP client\n"));
899 dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp));
900 if (dhcp == NULL) {
901 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n"));
902 return ERR_MEM;
903 }
904
905 /* store this dhcp client in the netif */
906 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp);
907 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): allocated dhcp\n"));
908 /* already has DHCP client attached */
909 } else {
910 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(): restarting DHCP configuration\n"));
911
912 if (dhcp->pcb_allocated != 0) {
913 dhcp_dec_pcb_refcount(); /* free DHCP PCB if not needed any more */
914 }
915 /* dhcp is cleared below, no need to reset flag*/
916 }
917
918 /* clear data structure */
919 memset(dhcp, 0, sizeof(struct dhcp));
920 /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */
921
922
923 #if LWIP_DHCP_DOES_ACD_CHECK
924 /* add acd struct to list*/
925 acd_add(netif, &dhcp->acd, dhcp_conflict_callback);
926 #endif /* LWIP_DHCP_DOES_ACD_CHECK */
927
928
929 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n"));
930
931 if (dhcp_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP PCB is allocated */
932 return ERR_MEM;
933 }
934 dhcp->pcb_allocated = 1;
935
936 if (!netif_is_link_up(netif)) {
937 /* set state INIT and wait for dhcp_network_changed() to call dhcp_discover() */
938 dhcp_set_state(dhcp, DHCP_STATE_INIT);
939 return ERR_OK;
940 }
941
942 /* (re)start the DHCP negotiation */
943 result = dhcp_discover(netif);
944 if (result != ERR_OK) {
945 /* free resources allocated above */
946 dhcp_release_and_stop(netif);
947 return ERR_MEM;
948 }
949 return result;
950 }
951
952 /**
953 * @ingroup dhcp4
954 * Inform a DHCP server of our manual configuration.
955 *
956 * This informs DHCP servers of our fixed IP address configuration
957 * by sending an INFORM message. It does not involve DHCP address
958 * configuration, it is just here to be nice to the network.
959 *
960 * @param netif The lwIP network interface
961 */
962 void
963 dhcp_inform(struct netif *netif)
964 {
965 struct dhcp dhcp;
966 struct pbuf *p_out;
967 u16_t options_out_len;
968
969 LWIP_ASSERT_CORE_LOCKED();
970 LWIP_ERROR("netif != NULL", (netif != NULL), return;);
971
972 if (dhcp_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP PCB is allocated */
973 return;
974 }
975
976 memset(&dhcp, 0, sizeof(struct dhcp));
977 dhcp_set_state(&dhcp, DHCP_STATE_INFORMING);
978
979 /* create and initialize the DHCP message header */
980 p_out = dhcp_create_msg(netif, &dhcp, DHCP_INFORM, &options_out_len);
981 if (p_out != NULL) {
982 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
983 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
984 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
985
986 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, &dhcp, DHCP_STATE_INFORMING, msg_out, DHCP_INFORM, &options_out_len);
987 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
988
989 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n"));
990
991 udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif);
992
993 pbuf_free(p_out);
994 } else {
995 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform: could not allocate DHCP request\n"));
996 }
997
998 dhcp_dec_pcb_refcount(); /* delete DHCP PCB if not needed any more */
999 }
1000
1001 /** Handle a possible change in the network configuration.
1002 *
1003 * This enters the REBOOTING state to verify that the currently bound
1004 * address is still valid.
1005 */
1006 void
1007 dhcp_network_changed_link_up(struct netif *netif)
1008 {
1009 struct dhcp *dhcp = netif_dhcp_data(netif);
1010
1011 if (!dhcp) {
1012 return;
1013 }
1014 switch (dhcp->state) {
1015 case DHCP_STATE_REBINDING:
1016 case DHCP_STATE_RENEWING:
1017 case DHCP_STATE_BOUND:
1018 case DHCP_STATE_REBOOTING:
1019 dhcp->tries = 0;
1020 dhcp_reboot(netif);
1021 break;
1022 case DHCP_STATE_OFF:
1023 /* stay off */
1024 break;
1025 default:
1026 LWIP_ASSERT("invalid dhcp->state", dhcp->state <= DHCP_STATE_BACKING_OFF);
1027 /* INIT/REQUESTING/CHECKING/BACKING_OFF restart with new 'rid' because the
1028 state changes, SELECTING: continue with current 'rid' as we stay in the
1029 same state */
1030 /* ensure we start with short timeouts, even if already discovering */
1031 dhcp->tries = 0;
1032 dhcp_discover(netif);
1033 break;
1034 }
1035 }
1036
1037 #if LWIP_DHCP_DOES_ACD_CHECK
1038 /**
1039 * Decline an offered lease.
1040 *
1041 * Tell the DHCP server we do not accept the offered address.
1042 * One reason to decline the lease is when we find out the address
1043 * is already in use by another host (through ARP).
1044 *
1045 * @param netif the netif under DHCP control
1046 */
1047 static err_t
1048 dhcp_decline(struct netif *netif)
1049 {
1050 struct dhcp *dhcp = netif_dhcp_data(netif);
1051 err_t result;
1052 struct pbuf *p_out;
1053 u16_t options_out_len;
1054
1055 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline()\n"));
1056 dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF);
1057
1058 /* create and initialize the DHCP message header */
1059 p_out = dhcp_create_msg(netif, dhcp, DHCP_DECLINE, &options_out_len);
1060 if (p_out != NULL) {
1061 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1062 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_REQUESTED_IP, 4);
1063 options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
1064
1065 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_BACKING_OFF, msg_out, DHCP_DECLINE, &options_out_len);
1066 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1067
1068 /* per section 4.4.4, broadcast DECLINE messages */
1069 result = udp_sendto_if_src(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif, IP4_ADDR_ANY);
1070 pbuf_free(p_out);
1071 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_decline: BACKING OFF\n"));
1072 } else {
1073 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
1074 ("dhcp_decline: could not allocate DHCP request\n"));
1075 result = ERR_MEM;
1076 }
1077 return result;
1078 }
1079 #endif /* LWIP_DHCP_DOES_ACD_CHECK */
1080
1081
1082 /**
1083 * Start the DHCP process, discover a DHCP server.
1084 *
1085 * @param netif the netif under DHCP control
1086 */
1087 static err_t
1088 dhcp_discover(struct netif *netif)
1089 {
1090 struct dhcp *dhcp = netif_dhcp_data(netif);
1091 err_t result = ERR_OK;
1092 u16_t msecs;
1093 u8_t i;
1094 struct pbuf *p_out;
1095 u16_t options_out_len;
1096
1097 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover()\n"));
1098
1099 #if LWIP_DHCP_AUTOIP_COOP
1100 if (dhcp->tries >= LWIP_DHCP_AUTOIP_COOP_TRIES) {
1101 autoip_start(netif);
1102 }
1103 #endif /* LWIP_DHCP_AUTOIP_COOP */
1104
1105 ip4_addr_set_any(&dhcp->offered_ip_addr);
1106 dhcp_set_state(dhcp, DHCP_STATE_SELECTING);
1107 /* create and initialize the DHCP message header */
1108 p_out = dhcp_create_msg(netif, dhcp, DHCP_DISCOVER, &options_out_len);
1109 if (p_out != NULL) {
1110 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1111 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n"));
1112
1113 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1114 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
1115
1116 #if LWIP_NETIF_HOSTNAME && LWIP_DHCP_DISCOVER_ADD_HOSTNAME
1117 options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif);
1118 #endif /* LWIP NETIF HOSTNAME && LWIP_DHCP_DISCOVER_ADD_HOSTNAME */
1119
1120 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
1121 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
1122 options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);
1123 }
1124 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_SELECTING, msg_out, DHCP_DISCOVER, &options_out_len);
1125 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1126
1127 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER)\n"));
1128 udp_sendto_if_src(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif, IP4_ADDR_ANY);
1129 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()\n"));
1130 pbuf_free(p_out);
1131 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover: SELECTING\n"));
1132 } else {
1133 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_discover: could not allocate DHCP request\n"));
1134 }
1135
1136 if (dhcp->tries < 255) {
1137 dhcp->tries++;
1138 }
1139 msecs = DHCP_REQUEST_BACKOFF_SEQUENCE(dhcp->tries);
1140 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
1141 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs));
1142 return result;
1143 }
1144
1145
1146 /**
1147 * Bind the interface to the offered IP address.
1148 *
1149 * @param netif network interface to bind to the offered address
1150 */
1151 static void
1152 dhcp_bind(struct netif *netif)
1153 {
1154 struct dhcp *dhcp;
1155 ip4_addr_t sn_mask, gw_addr;
1156 LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;);
1157 dhcp = netif_dhcp_data(netif);
1158 LWIP_ERROR("dhcp_bind: dhcp != NULL", (dhcp != NULL), return;);
1159 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));
1160
1161 /* reset time used of lease */
1162 dhcp->lease_used = 0;
1163
1164 if (dhcp->offered_t0_lease != 0xffffffffUL) {
1165 /* set renewal period timer */
1166 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t0 renewal timer %"U32_F" secs\n", dhcp->offered_t0_lease));
1167 DHCP_SET_TIMEOUT_FROM_OFFERED_T0_LEASE(dhcp->t0_timeout, dhcp);
1168 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t0_lease * 1000));
1169 }
1170
1171 /* temporary DHCP lease? */
1172 if (dhcp->offered_t1_renew != 0xffffffffUL) {
1173 /* set renewal period timer */
1174 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew));
1175 DHCP_SET_TIMEOUT_FROM_OFFERED_T1_RENEW(dhcp->t1_timeout, dhcp);
1176 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew * 1000));
1177 dhcp->t1_renew_time = dhcp->t1_timeout;
1178 }
1179 /* set renewal period timer */
1180 if (dhcp->offered_t2_rebind != 0xffffffffUL) {
1181 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind));
1182 DHCP_SET_TIMEOUT_FROM_OFFERED_T2_REBIND(dhcp->t2_timeout, dhcp);
1183 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t2_rebind * 1000));
1184 dhcp->t2_rebind_time = dhcp->t2_timeout;
1185 }
1186
1187 /* If we have sub 1 minute lease, t2 and t1 will kick in at the same time. */
1188 if ((dhcp->t1_timeout >= dhcp->t2_timeout) && (dhcp->t2_timeout > 0)) {
1189 dhcp->t1_timeout = 0;
1190 }
1191
1192 if (dhcp->flags & DHCP_FLAG_SUBNET_MASK_GIVEN) {
1193 /* copy offered network mask */
1194 ip4_addr_copy(sn_mask, dhcp->offered_sn_mask);
1195 } else {
1196 /* subnet mask not given, choose a safe subnet mask given the network class */
1197 u8_t first_octet = ip4_addr1(&dhcp->offered_ip_addr);
1198 if (first_octet <= 127) {
1199 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xff000000UL));
1200 } else if (first_octet >= 192) {
1201 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffffff00UL));
1202 } else {
1203 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffff0000UL));
1204 }
1205 }
1206
1207 ip4_addr_copy(gw_addr, dhcp->offered_gw_addr);
1208
1209 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",
1210 ip4_addr_get_u32(&dhcp->offered_ip_addr), ip4_addr_get_u32(&sn_mask), ip4_addr_get_u32(&gw_addr)));
1211 /* netif is now bound to DHCP leased address - set this before assigning the address
1212 to ensure the callback can use dhcp_supplied_address() */
1213 dhcp_set_state(dhcp, DHCP_STATE_BOUND);
1214
1215 netif_set_addr(netif, &dhcp->offered_ip_addr, &sn_mask, &gw_addr);
1216 /* interface is used by routing now that an address is set */
1217 }
1218
1219 /**
1220 * @ingroup dhcp4
1221 * Renew an existing DHCP lease at the involved DHCP server.
1222 *
1223 * @param netif network interface which must renew its lease
1224 */
1225 err_t
1226 dhcp_renew(struct netif *netif)
1227 {
1228 struct dhcp *dhcp = netif_dhcp_data(netif);
1229 err_t result;
1230 u16_t msecs;
1231 u8_t i;
1232 struct pbuf *p_out;
1233 u16_t options_out_len;
1234
1235 LWIP_ASSERT_CORE_LOCKED();
1236 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_renew()\n"));
1237 dhcp_set_state(dhcp, DHCP_STATE_RENEWING);
1238
1239 /* create and initialize the DHCP message header */
1240 p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len);
1241 if (p_out != NULL) {
1242 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1243 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1244 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
1245
1246 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
1247 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
1248 options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);
1249 }
1250
1251 #if LWIP_NETIF_HOSTNAME
1252 options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif);
1253 #endif /* LWIP_NETIF_HOSTNAME */
1254
1255 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_RENEWING, msg_out, DHCP_REQUEST, &options_out_len);
1256 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1257
1258 result = udp_sendto_if(dhcp_pcb, p_out, &dhcp->server_ip_addr, LWIP_IANA_PORT_DHCP_SERVER, netif);
1259 pbuf_free(p_out);
1260
1261 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew: RENEWING\n"));
1262 } else {
1263 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_renew: could not allocate DHCP request\n"));
1264 result = ERR_MEM;
1265 }
1266 if (dhcp->tries < 255) {
1267 dhcp->tries++;
1268 }
1269 /* back-off on retries, but to a maximum of 20 seconds */
1270 msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000);
1271 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
1272 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs));
1273 return result;
1274 }
1275
1276 /**
1277 * Rebind with a DHCP server for an existing DHCP lease.
1278 *
1279 * @param netif network interface which must rebind with a DHCP server
1280 */
1281 static err_t
1282 dhcp_rebind(struct netif *netif)
1283 {
1284 struct dhcp *dhcp = netif_dhcp_data(netif);
1285 err_t result;
1286 u16_t msecs;
1287 u8_t i;
1288 struct pbuf *p_out;
1289 u16_t options_out_len;
1290
1291 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n"));
1292 dhcp_set_state(dhcp, DHCP_STATE_REBINDING);
1293
1294 /* create and initialize the DHCP message header */
1295 p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len);
1296 if (p_out != NULL) {
1297 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1298 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1299 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
1300
1301 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
1302 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
1303 options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);
1304 }
1305
1306 #if LWIP_NETIF_HOSTNAME
1307 options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif);
1308 #endif /* LWIP_NETIF_HOSTNAME */
1309
1310 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_REBINDING, msg_out, DHCP_DISCOVER, &options_out_len);
1311 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1312
1313 /* broadcast to server */
1314 result = udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif);
1315 pbuf_free(p_out);
1316 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n"));
1317 } else {
1318 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_rebind: could not allocate DHCP request\n"));
1319 result = ERR_MEM;
1320 }
1321 if (dhcp->tries < 255) {
1322 dhcp->tries++;
1323 }
1324 msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000);
1325 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
1326 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs));
1327 return result;
1328 }
1329
1330 /**
1331 * Enter REBOOTING state to verify an existing lease
1332 *
1333 * @param netif network interface which must reboot
1334 */
1335 static err_t
1336 dhcp_reboot(struct netif *netif)
1337 {
1338 struct dhcp *dhcp = netif_dhcp_data(netif);
1339 err_t result;
1340 u16_t msecs;
1341 u8_t i;
1342 struct pbuf *p_out;
1343 u16_t options_out_len;
1344
1345 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n"));
1346 dhcp_set_state(dhcp, DHCP_STATE_REBOOTING);
1347
1348 /* create and initialize the DHCP message header */
1349 p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len);
1350 if (p_out != NULL) {
1351 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1352 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
1353 options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN_MIN_REQUIRED);
1354
1355 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_REQUESTED_IP, 4);
1356 options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr)));
1357
1358 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
1359 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
1360 options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);
1361 }
1362
1363 #if LWIP_NETIF_HOSTNAME
1364 options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif);
1365 #endif /* LWIP_NETIF_HOSTNAME */
1366
1367 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_REBOOTING, msg_out, DHCP_REQUEST, &options_out_len);
1368 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1369
1370 /* broadcast to server */
1371 result = udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif);
1372 pbuf_free(p_out);
1373 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot: REBOOTING\n"));
1374 } else {
1375 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_reboot: could not allocate DHCP request\n"));
1376 result = ERR_MEM;
1377 }
1378 if (dhcp->tries < 255) {
1379 dhcp->tries++;
1380 }
1381 msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000);
1382 dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS);
1383 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot(): set request timeout %"U16_F" msecs\n", msecs));
1384 return result;
1385 }
1386
1387 /**
1388 * @ingroup dhcp4
1389 * Release a DHCP lease and stop DHCP statemachine (and AUTOIP if LWIP_DHCP_AUTOIP_COOP).
1390 *
1391 * @param netif network interface
1392 */
1393 void
1394 dhcp_release_and_stop(struct netif *netif)
1395 {
1396 struct dhcp *dhcp = netif_dhcp_data(netif);
1397 ip_addr_t server_ip_addr;
1398
1399 LWIP_ASSERT_CORE_LOCKED();
1400 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release_and_stop()\n"));
1401 if (dhcp == NULL) {
1402 return;
1403 }
1404
1405 /* already off? -> nothing to do */
1406 if (dhcp->state == DHCP_STATE_OFF) {
1407 return;
1408 }
1409
1410 ip_addr_copy(server_ip_addr, dhcp->server_ip_addr);
1411
1412 /* clean old DHCP offer */
1413 ip_addr_set_zero_ip4(&dhcp->server_ip_addr);
1414 ip4_addr_set_zero(&dhcp->offered_ip_addr);
1415 ip4_addr_set_zero(&dhcp->offered_sn_mask);
1416 ip4_addr_set_zero(&dhcp->offered_gw_addr);
1417 #if LWIP_DHCP_BOOTP_FILE
1418 ip4_addr_set_zero(&dhcp->offered_si_addr);
1419 #endif /* LWIP_DHCP_BOOTP_FILE */
1420 dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0;
1421 dhcp->t1_renew_time = dhcp->t2_rebind_time = dhcp->lease_used = dhcp->t0_timeout = 0;
1422
1423 /* send release message when current IP was assigned via DHCP */
1424 if (dhcp_supplied_address(netif)) {
1425 /* create and initialize the DHCP message header */
1426 struct pbuf *p_out;
1427 u16_t options_out_len;
1428 dhcp_set_state(dhcp, DHCP_STATE_OFF);
1429 p_out = dhcp_create_msg(netif, dhcp, DHCP_RELEASE, &options_out_len);
1430 if (p_out != NULL) {
1431 struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload;
1432 options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_SERVER_ID, 4);
1433 options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(ip_2_ip4(&server_ip_addr))));
1434
1435 LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, dhcp->state, msg_out, DHCP_RELEASE, &options_out_len);
1436 dhcp_option_trailer(options_out_len, msg_out->options, p_out);
1437
1438 udp_sendto_if(dhcp_pcb, p_out, &server_ip_addr, LWIP_IANA_PORT_DHCP_SERVER, netif);
1439 pbuf_free(p_out);
1440 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_STATE_OFF\n"));
1441 } else {
1442 /* sending release failed, but that's not a problem since the correct behaviour of dhcp does not rely on release */
1443 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n"));
1444 }
1445
1446 /* remove IP address from interface (prevents routing from selecting this interface) */
1447 netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4);
1448 } else {
1449 dhcp_set_state(dhcp, DHCP_STATE_OFF);
1450 }
1451
1452 #if LWIP_DHCP_DOES_ACD_CHECK
1453 /* stop acd because we may be in checking state and the callback would trigger a bind */
1454 acd_remove(netif, &dhcp->acd);
1455 #endif
1456
1457 if (dhcp->pcb_allocated != 0) {
1458 dhcp_dec_pcb_refcount(); /* free DHCP PCB if not needed any more */
1459 dhcp->pcb_allocated = 0;
1460 }
1461 }
1462
1463 /**
1464 * @ingroup dhcp4
1465 * This function calls dhcp_release_and_stop() internally.
1466 * @deprecated Use dhcp_release_and_stop() instead.
1467 */
1468 err_t
1469 dhcp_release(struct netif *netif)
1470 {
1471 dhcp_release_and_stop(netif);
1472 return ERR_OK;
1473 }
1474
1475 /**
1476 * @ingroup dhcp4
1477 * This function calls dhcp_release_and_stop() internally.
1478 * @deprecated Use dhcp_release_and_stop() instead.
1479 */
1480 void
1481 dhcp_stop(struct netif *netif)
1482 {
1483 dhcp_release_and_stop(netif);
1484 }
1485
1486 /*
1487 * Set the DHCP state of a DHCP client.
1488 *
1489 * If the state changed, reset the number of tries.
1490 */
1491 static void
1492 dhcp_set_state(struct dhcp *dhcp, u8_t new_state)
1493 {
1494 if (new_state != dhcp->state) {
1495 dhcp->state = new_state;
1496 dhcp->tries = 0;
1497 dhcp->request_timeout = 0;
1498 }
1499 }
1500
1501 /*
1502 * Concatenate an option type and length field to the outgoing
1503 * DHCP message.
1504 *
1505 */
1506 static u16_t
1507 dhcp_option(u16_t options_out_len, u8_t *options, u8_t option_type, u8_t option_len)
1508 {
1509 LWIP_ASSERT("dhcp_option: options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN);
1510 options[options_out_len++] = option_type;
1511 options[options_out_len++] = option_len;
1512 return options_out_len;
1513 }
1514 /*
1515 * Concatenate a single byte to the outgoing DHCP message.
1516 *
1517 */
1518 static u16_t
1519 dhcp_option_byte(u16_t options_out_len, u8_t *options, u8_t value)
1520 {
1521 LWIP_ASSERT("dhcp_option_byte: options_out_len < DHCP_OPTIONS_LEN", options_out_len < DHCP_OPTIONS_LEN);
1522 options[options_out_len++] = value;
1523 return options_out_len;
1524 }
1525
1526 static u16_t
1527 dhcp_option_short(u16_t options_out_len, u8_t *options, u16_t value)
1528 {
1529 LWIP_ASSERT("dhcp_option_short: options_out_len + 2 <= DHCP_OPTIONS_LEN", options_out_len + 2U <= DHCP_OPTIONS_LEN);
1530 options[options_out_len++] = (u8_t)((value & 0xff00U) >> 8);
1531 options[options_out_len++] = (u8_t) (value & 0x00ffU);
1532 return options_out_len;
1533 }
1534
1535 static u16_t
1536 dhcp_option_long(u16_t options_out_len, u8_t *options, u32_t value)
1537 {
1538 LWIP_ASSERT("dhcp_option_long: options_out_len + 4 <= DHCP_OPTIONS_LEN", options_out_len + 4U <= DHCP_OPTIONS_LEN);
1539 options[options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24);
1540 options[options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16);
1541 options[options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8);
1542 options[options_out_len++] = (u8_t)((value & 0x000000ffUL));
1543 return options_out_len;
1544 }
1545
1546 #if LWIP_NETIF_HOSTNAME
1547 static u16_t
1548 dhcp_option_hostname(u16_t options_out_len, u8_t *options, struct netif *netif)
1549 {
1550 if (netif->hostname != NULL) {
1551 size_t namelen = strlen(netif->hostname);
1552 if (namelen > 0) {
1553 size_t len;
1554 const char *p = netif->hostname;
1555 /* Shrink len to available bytes (need 2 bytes for OPTION_HOSTNAME
1556 and 1 byte for trailer) */
1557 size_t available = DHCP_OPTIONS_LEN - options_out_len - 3;
1558 LWIP_ASSERT("DHCP: hostname is too long!", namelen <= available);
1559 len = LWIP_MIN(namelen, available);
1560 LWIP_ASSERT("DHCP: hostname is too long!", len <= 0xFF);
1561 options_out_len = dhcp_option(options_out_len, options, DHCP_OPTION_HOSTNAME, (u8_t)len);
1562 while (len--) {
1563 options_out_len = dhcp_option_byte(options_out_len, options, *p++);
1564 }
1565 }
1566 }
1567 return options_out_len;
1568 }
1569 #endif /* LWIP_NETIF_HOSTNAME */
1570
1571 /**
1572 * Extract the DHCP message and the DHCP options.
1573 *
1574 * Extract the DHCP message and the DHCP options, each into a contiguous
1575 * piece of memory. As a DHCP message is variable sized by its options,
1576 * and also allows overriding some fields for options, the easy approach
1577 * is to first unfold the options into a contiguous piece of memory, and
1578 * use that further on.
1579 *
1580 */
1581 static err_t
1582 dhcp_parse_reply(struct pbuf *p, struct dhcp *dhcp)
1583 {
1584 u8_t *options;
1585 u16_t offset;
1586 u16_t offset_max;
1587 u16_t options_offset;
1588 u16_t options_idx;
1589 u16_t options_idx_max;
1590 struct pbuf *q;
1591 int parse_file_as_options = 0;
1592 int parse_sname_as_options = 0;
1593 struct dhcp_msg *msg_in;
1594 #if LWIP_DHCP_BOOTP_FILE
1595 int file_overloaded = 0;
1596 #endif
1597
1598 LWIP_UNUSED_ARG(dhcp);
1599
1600 /* clear received options */
1601 dhcp_clear_all_options(dhcp);
1602 /* check that beginning of dhcp_msg (up to and including chaddr) is in first pbuf */
1603 if (p->len < DHCP_SNAME_OFS) {
1604 return ERR_BUF;
1605 }
1606 msg_in = (struct dhcp_msg *)p->payload;
1607 #if LWIP_DHCP_BOOTP_FILE
1608 /* clear boot file name */
1609 dhcp->boot_file_name[0] = 0;
1610 #endif /* LWIP_DHCP_BOOTP_FILE */
1611
1612 /* parse options */
1613
1614 /* start with options field */
1615 options_idx = DHCP_OPTIONS_OFS;
1616 /* parse options to the end of the received packet */
1617 options_idx_max = p->tot_len;
1618 again:
1619 q = p;
1620 options_offset = options_idx;
1621 while ((q != NULL) && (options_idx >= q->len)) {
1622 options_idx = (u16_t)(options_idx - q->len);
1623 options_idx_max = (u16_t)(options_idx_max - q->len);
1624 q = q->next;
1625 }
1626 if (q == NULL) {
1627 return ERR_BUF;
1628 }
1629 offset = options_idx;
1630 offset_max = options_idx_max;
1631 options = (u8_t *)q->payload;
1632 /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */
1633 while ((q != NULL) && (offset < offset_max) && (options[offset] != DHCP_OPTION_END)) {
1634 u8_t op = options[offset];
1635 u8_t len;
1636 u8_t decode_len = 0;
1637 int decode_idx = -1;
1638 u16_t val_offset = (u16_t)(offset + 2);
1639 if (val_offset < offset) {
1640 /* overflow */
1641 return ERR_BUF;
1642 }
1643 /* len byte might be in the next pbuf */
1644 if ((offset + 1) < q->len) {
1645 len = options[offset + 1];
1646 } else {
1647 len = (q->next != NULL ? ((u8_t *)q->next->payload)[0] : 0);
1648 }
1649 /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F"\n", msg_offset, q->len)); */
1650 decode_len = len;
1651 switch (op) {
1652 /* case(DHCP_OPTION_END): handled above */
1653 case (DHCP_OPTION_PAD):
1654 /* special option: no len encoded */
1655 decode_len = len = 0;
1656 /* will be increased below */
1657 break;
1658 case (DHCP_OPTION_SUBNET_MASK):
1659 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1660 decode_idx = DHCP_OPTION_IDX_SUBNET_MASK;
1661 break;
1662 case (DHCP_OPTION_ROUTER):
1663 decode_len = 4; /* only copy the first given router */
1664 LWIP_DHCP_INPUT_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;);
1665 decode_idx = DHCP_OPTION_IDX_ROUTER;
1666 break;
1667 #if LWIP_DHCP_PROVIDE_DNS_SERVERS
1668 case (DHCP_OPTION_DNS_SERVER):
1669 /* special case: there might be more than one server */
1670 LWIP_DHCP_INPUT_ERROR("len %% 4 == 0", len % 4 == 0, return ERR_VAL;);
1671 /* limit number of DNS servers */
1672 decode_len = LWIP_MIN(len, 4 * LWIP_DHCP_PROVIDE_DNS_SERVERS);
1673 LWIP_DHCP_INPUT_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;);
1674 decode_idx = DHCP_OPTION_IDX_DNS_SERVER;
1675 break;
1676 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */
1677 case (DHCP_OPTION_LEASE_TIME):
1678 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1679 decode_idx = DHCP_OPTION_IDX_LEASE_TIME;
1680 break;
1681 #if LWIP_DHCP_GET_NTP_SRV
1682 case (DHCP_OPTION_NTP):
1683 /* special case: there might be more than one server */
1684 LWIP_DHCP_INPUT_ERROR("len %% 4 == 0", len % 4 == 0, return ERR_VAL;);
1685 /* limit number of NTP servers */
1686 decode_len = LWIP_MIN(len, 4 * LWIP_DHCP_MAX_NTP_SERVERS);
1687 LWIP_DHCP_INPUT_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;);
1688 decode_idx = DHCP_OPTION_IDX_NTP_SERVER;
1689 break;
1690 #endif /* LWIP_DHCP_GET_NTP_SRV*/
1691 case (DHCP_OPTION_OVERLOAD):
1692 LWIP_DHCP_INPUT_ERROR("len == 1", len == 1, return ERR_VAL;);
1693 /* decode overload only in options, not in file/sname: invalid packet */
1694 LWIP_DHCP_INPUT_ERROR("overload in file/sname", options_offset == DHCP_OPTIONS_OFS, return ERR_VAL;);
1695 decode_idx = DHCP_OPTION_IDX_OVERLOAD;
1696 break;
1697 case (DHCP_OPTION_MESSAGE_TYPE):
1698 LWIP_DHCP_INPUT_ERROR("len == 1", len == 1, return ERR_VAL;);
1699 decode_idx = DHCP_OPTION_IDX_MSG_TYPE;
1700 break;
1701 case (DHCP_OPTION_SERVER_ID):
1702 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1703 decode_idx = DHCP_OPTION_IDX_SERVER_ID;
1704 break;
1705 case (DHCP_OPTION_T1):
1706 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1707 decode_idx = DHCP_OPTION_IDX_T1;
1708 break;
1709 case (DHCP_OPTION_T2):
1710 LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;);
1711 decode_idx = DHCP_OPTION_IDX_T2;
1712 break;
1713 default:
1714 decode_len = 0;
1715 LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", (u16_t)op));
1716 LWIP_HOOK_DHCP_PARSE_OPTION(ip_current_netif(), dhcp, dhcp->state, msg_in,
1717 dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) ? (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) : 0,
1718 op, len, q, val_offset);
1719 break;
1720 }
1721 if (op == DHCP_OPTION_PAD) {
1722 offset++;
1723 } else {
1724 if (offset + len + 2 > 0xFFFF) {
1725 /* overflow */
1726 return ERR_BUF;
1727 }
1728 offset = (u16_t)(offset + len + 2);
1729 if (decode_len > 0) {
1730 u32_t value = 0;
1731 u16_t copy_len;
1732 decode_next:
1733 LWIP_ASSERT("check decode_idx", decode_idx >= 0 && decode_idx < DHCP_OPTION_IDX_MAX);
1734 if (!dhcp_option_given(dhcp, decode_idx)) {
1735 copy_len = LWIP_MIN(decode_len, 4);
1736 if (pbuf_copy_partial(q, &value, copy_len, val_offset) != copy_len) {
1737 return ERR_BUF;
1738 }
1739 if (decode_len > 4) {
1740 /* decode more than one u32_t */
1741 u16_t next_val_offset;
1742 LWIP_DHCP_INPUT_ERROR("decode_len %% 4 == 0", decode_len % 4 == 0, return ERR_VAL;);
1743 dhcp_got_option(dhcp, decode_idx);
1744 dhcp_set_option_value(dhcp, decode_idx, lwip_htonl(value));
1745 decode_len = (u8_t)(decode_len - 4);
1746 next_val_offset = (u16_t)(val_offset + 4);
1747 if (next_val_offset < val_offset) {
1748 /* overflow */
1749 return ERR_BUF;
1750 }
1751 val_offset = next_val_offset;
1752 decode_idx++;
1753 goto decode_next;
1754 } else if (decode_len == 4) {
1755 value = lwip_ntohl(value);
1756 } else {
1757 LWIP_DHCP_INPUT_ERROR("invalid decode_len", decode_len == 1, return ERR_VAL;);
1758 value = ((u8_t *)&value)[0];
1759 }
1760 dhcp_got_option(dhcp, decode_idx);
1761 dhcp_set_option_value(dhcp, decode_idx, value);
1762 }
1763 }
1764 }
1765 if (offset >= q->len) {
1766 offset = (u16_t)(offset - q->len);
1767 offset_max = (u16_t)(offset_max - q->len);
1768 if (offset < offset_max) {
1769 q = q->next;
1770 LWIP_DHCP_INPUT_ERROR("next pbuf was null", q != NULL, return ERR_VAL;);
1771 options = (u8_t *)q->payload;
1772 } else {
1773 /* We've run out of bytes, probably no end marker. Don't proceed. */
1774 return ERR_BUF;
1775 }
1776 }
1777 }
1778 /* is this an overloaded message? */
1779 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_OVERLOAD)) {
1780 u32_t overload = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_OVERLOAD);
1781 dhcp_clear_option(dhcp, DHCP_OPTION_IDX_OVERLOAD);
1782 if (overload == DHCP_OVERLOAD_FILE) {
1783 parse_file_as_options = 1;
1784 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded file field\n"));
1785 } else if (overload == DHCP_OVERLOAD_SNAME) {
1786 parse_sname_as_options = 1;
1787 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname field\n"));
1788 } else if (overload == DHCP_OVERLOAD_SNAME_FILE) {
1789 parse_sname_as_options = 1;
1790 parse_file_as_options = 1;
1791 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname and file field\n"));
1792 } else {
1793 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("invalid overload option: %d\n", (int)overload));
1794 }
1795 }
1796 if (parse_file_as_options) {
1797 /* if both are overloaded, parse file first and then sname (RFC 2131 ch. 4.1) */
1798 parse_file_as_options = 0;
1799 options_idx = DHCP_FILE_OFS;
1800 options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN;
1801 #if LWIP_DHCP_BOOTP_FILE
1802 file_overloaded = 1;
1803 #endif
1804 goto again;
1805 } else if (parse_sname_as_options) {
1806 parse_sname_as_options = 0;
1807 options_idx = DHCP_SNAME_OFS;
1808 options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN;
1809 goto again;
1810 }
1811 #if LWIP_DHCP_BOOTP_FILE
1812 if (!file_overloaded) {
1813 /* only do this for ACK messages */
1814 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) &&
1815 (dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK))
1816 /* copy bootp file name, don't care for sname (server hostname) */
1817 if (pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS) != (DHCP_FILE_LEN-1)) {
1818 return ERR_BUF;
1819 }
1820 /* make sure the string is really NULL-terminated */
1821 dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0;
1822 }
1823 #endif /* LWIP_DHCP_BOOTP_FILE */
1824 return ERR_OK;
1825 }
1826
1827 /**
1828 * If an incoming DHCP message is in response to us, then trigger the state machine
1829 */
1830 static void
1831 dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port)
1832 {
1833 struct netif *netif = ip_current_input_netif();
1834 struct dhcp *dhcp = netif_dhcp_data(netif);
1835 struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload;
1836 u8_t msg_type;
1837 u8_t i;
1838 struct dhcp_msg *msg_in;
1839
1840 LWIP_UNUSED_ARG(arg);
1841
1842 /* Caught DHCP message from netif that does not have DHCP enabled? -> not interested */
1843 if ((dhcp == NULL) || (dhcp->pcb_allocated == 0)) {
1844 goto free_pbuf_and_return;
1845 }
1846
1847 LWIP_ASSERT("invalid server address type", IP_IS_V4(addr));
1848
1849 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,
1850 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));
1851 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len));
1852 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len));
1853 /* prevent warnings about unused arguments */
1854 LWIP_UNUSED_ARG(pcb);
1855 LWIP_UNUSED_ARG(addr);
1856 LWIP_UNUSED_ARG(port);
1857
1858 if (p->len < DHCP_MIN_REPLY_LEN) {
1859 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP reply message or pbuf too short\n"));
1860 goto free_pbuf_and_return;
1861 }
1862
1863 if (reply_msg->op != DHCP_BOOTREPLY) {
1864 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));
1865 goto free_pbuf_and_return;
1866 }
1867 /* iterate through hardware address and match against DHCP message */
1868 for (i = 0; i < netif->hwaddr_len && i < LWIP_MIN(DHCP_CHADDR_LEN, NETIF_MAX_HWADDR_LEN); i++) {
1869 if (netif->hwaddr[i] != reply_msg->chaddr[i]) {
1870 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
1871 ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n",
1872 (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i]));
1873 goto free_pbuf_and_return;
1874 }
1875 }
1876 /* match transaction ID against what we expected */
1877 if (lwip_ntohl(reply_msg->xid) != dhcp->xid) {
1878 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
1879 ("transaction id mismatch reply_msg->xid(%"X32_F")!=dhcp->xid(%"X32_F")\n", lwip_ntohl(reply_msg->xid), dhcp->xid));
1880 goto free_pbuf_and_return;
1881 }
1882 /* option fields could be unfold? */
1883 if (dhcp_parse_reply(p, dhcp) != ERR_OK) {
1884 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
1885 ("problem unfolding DHCP message - too short on memory?\n"));
1886 goto free_pbuf_and_return;
1887 }
1888
1889 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n"));
1890 /* obtain pointer to DHCP message type */
1891 if (!dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE)) {
1892 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP_OPTION_MESSAGE_TYPE option not found\n"));
1893 goto free_pbuf_and_return;
1894 }
1895
1896 msg_in = (struct dhcp_msg *)p->payload;
1897 /* read DHCP message type */
1898 msg_type = (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE);
1899 /* message type is DHCP ACK? */
1900 if (msg_type == DHCP_ACK) {
1901 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_ACK received\n"));
1902 /* in requesting state or just reconnected to the network? */
1903 if ((dhcp->state == DHCP_STATE_REQUESTING) ||
1904 (dhcp->state == DHCP_STATE_REBOOTING)) {
1905 dhcp_handle_ack(netif, msg_in);
1906 #if LWIP_DHCP_DOES_ACD_CHECK
1907 if ((netif->flags & NETIF_FLAG_ETHARP) != 0) {
1908 /* check if the acknowledged lease address is already in use */
1909 dhcp_check(netif);
1910 } else {
1911 /* bind interface to the acknowledged lease address */
1912 dhcp_bind(netif);
1913 }
1914 #else
1915 /* bind interface to the acknowledged lease address */
1916 dhcp_bind(netif);
1917 #endif
1918 }
1919 /* already bound to the given lease address and using it? */
1920 else if ((dhcp->state == DHCP_STATE_REBINDING) ||
1921 (dhcp->state == DHCP_STATE_RENEWING)) {
1922 dhcp_handle_ack(netif, msg_in);
1923 dhcp_bind(netif);
1924 }
1925 }
1926 /* received a DHCP_NAK in appropriate state? */
1927 else if ((msg_type == DHCP_NAK) &&
1928 ((dhcp->state == DHCP_STATE_REBOOTING) || (dhcp->state == DHCP_STATE_REQUESTING) ||
1929 (dhcp->state == DHCP_STATE_REBINDING) || (dhcp->state == DHCP_STATE_RENEWING ))) {
1930 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_NAK received\n"));
1931 dhcp_handle_nak(netif);
1932 }
1933 /* received a DHCP_OFFER in DHCP_STATE_SELECTING state? */
1934 else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_STATE_SELECTING)) {
1935 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_OFFER received in DHCP_STATE_SELECTING state\n"));
1936 /* remember offered lease */
1937 dhcp_handle_offer(netif, msg_in);
1938 }
1939
1940 free_pbuf_and_return:
1941 pbuf_free(p);
1942 }
1943
1944 /**
1945 * Create a DHCP request, fill in common headers
1946 *
1947 * @param netif the netif under DHCP control
1948 * @param dhcp dhcp control struct
1949 * @param message_type message type of the request
1950 */
1951 static struct pbuf *
1952 dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type, u16_t *options_out_len)
1953 {
1954 u16_t i;
1955 struct pbuf *p_out;
1956 struct dhcp_msg *msg_out;
1957 u16_t options_out_len_loc;
1958
1959 #ifndef DHCP_GLOBAL_XID
1960 /** default global transaction identifier starting value (easy to match
1961 * with a packet analyser). We simply increment for each new request.
1962 * Predefine DHCP_GLOBAL_XID to a better value or a function call to generate one
1963 * at runtime, any supporting function prototypes can be defined in DHCP_GLOBAL_XID_HEADER */
1964 #if DHCP_CREATE_RAND_XID && defined(LWIP_RAND)
1965 static u32_t xid;
1966 #else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1967 static u32_t xid = 0xABCD0000;
1968 #endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1969 #else
1970 if (!xid_initialised) {
1971 xid = DHCP_GLOBAL_XID;
1972 xid_initialised = !xid_initialised;
1973 }
1974 #endif
1975 LWIP_ERROR("dhcp_create_msg: netif != NULL", (netif != NULL), return NULL;);
1976 LWIP_ERROR("dhcp_create_msg: dhcp != NULL", (dhcp != NULL), return NULL;);
1977 p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM);
1978 if (p_out == NULL) {
1979 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
1980 ("dhcp_create_msg(): could not allocate pbuf\n"));
1981 return NULL;
1982 }
1983 LWIP_ASSERT("dhcp_create_msg: check that first pbuf can hold struct dhcp_msg",
1984 (p_out->len >= sizeof(struct dhcp_msg)));
1985
1986 /* DHCP_REQUEST should reuse 'xid' from DHCPOFFER */
1987 if ((message_type != DHCP_REQUEST) || (dhcp->state == DHCP_STATE_REBOOTING)) {
1988 /* reuse transaction identifier in retransmissions */
1989 if (dhcp->tries == 0) {
1990 #if DHCP_CREATE_RAND_XID && defined(LWIP_RAND)
1991 xid = LWIP_RAND();
1992 #else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1993 xid++;
1994 #endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */
1995 }
1996 dhcp->xid = xid;
1997 }
1998 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE,
1999 ("transaction id xid(%"X32_F")\n", xid));
2000
2001 msg_out = (struct dhcp_msg *)p_out->payload;
2002 memset(msg_out, 0, sizeof(struct dhcp_msg));
2003
2004 msg_out->op = DHCP_BOOTREQUEST;
2005 /* @todo: make link layer independent */
2006 msg_out->htype = LWIP_IANA_HWTYPE_ETHERNET;
2007 msg_out->hlen = netif->hwaddr_len;
2008 msg_out->xid = lwip_htonl(dhcp->xid);
2009 /* we don't need the broadcast flag since we can receive unicast traffic
2010 before being fully configured! */
2011 /* set ciaddr to netif->ip_addr based on message_type and state */
2012 if ((message_type == DHCP_INFORM) || (message_type == DHCP_DECLINE) || (message_type == DHCP_RELEASE) ||
2013 ((message_type == DHCP_REQUEST) && /* DHCP_STATE_BOUND not used for sending! */
2014 ((dhcp->state == DHCP_STATE_RENEWING) || dhcp->state == DHCP_STATE_REBINDING))) {
2015 ip4_addr_copy(msg_out->ciaddr, *netif_ip4_addr(netif));
2016 }
2017 for (i = 0; i < LWIP_MIN(DHCP_CHADDR_LEN, NETIF_MAX_HWADDR_LEN); i++) {
2018 /* copy netif hardware address (padded with zeroes through memset already) */
2019 msg_out->chaddr[i] = netif->hwaddr[i];
2020 }
2021 msg_out->cookie = PP_HTONL(DHCP_MAGIC_COOKIE);
2022 /* Add option MESSAGE_TYPE */
2023 options_out_len_loc = dhcp_option(0, msg_out->options, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
2024 options_out_len_loc = dhcp_option_byte(options_out_len_loc, msg_out->options, message_type);
2025 if (options_out_len) {
2026 *options_out_len = options_out_len_loc;
2027 }
2028 return p_out;
2029 }
2030
2031 /**
2032 * Add a DHCP message trailer
2033 *
2034 * Adds the END option to the DHCP message, and if
2035 * necessary, up to three padding bytes.
2036 */
2037 static void
2038 dhcp_option_trailer(u16_t options_out_len, u8_t *options, struct pbuf *p_out)
2039 {
2040 options[options_out_len++] = DHCP_OPTION_END;
2041 /* packet is too small, or not 4 byte aligned? */
2042 while (((options_out_len < DHCP_MIN_OPTIONS_LEN) || (options_out_len & 3)) &&
2043 (options_out_len < DHCP_OPTIONS_LEN)) {
2044 /* add a fill/padding byte */
2045 options[options_out_len++] = 0;
2046 }
2047 /* shrink the pbuf to the actual content length */
2048 pbuf_realloc(p_out, (u16_t)(sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + options_out_len));
2049 }
2050
2051 /** check if DHCP supplied netif->ip_addr
2052 *
2053 * @param netif the netif to check
2054 * @return 1 if DHCP supplied netif->ip_addr (states BOUND or RENEWING),
2055 * 0 otherwise
2056 */
2057 u8_t
2058 dhcp_supplied_address(const struct netif *netif)
2059 {
2060 if ((netif != NULL) && (netif_dhcp_data(netif) != NULL)) {
2061 struct dhcp *dhcp = netif_dhcp_data(netif);
2062 return (dhcp->state == DHCP_STATE_BOUND) || (dhcp->state == DHCP_STATE_RENEWING) ||
2063 (dhcp->state == DHCP_STATE_REBINDING);
2064 }
2065 return 0;
2066 }
2067
2068 #endif /* LWIP_IPV4 && LWIP_DHCP */
2069