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 netifapi_dhcp4 25 */ 26 27 /* 28 * Copyright (c) 2001-2004 Leon Woestenberg <leon.woestenberg@gmx.net> 29 * Copyright (c) 2001-2004 Axon Digital Design B.V., The Netherlands. 30 * All rights reserved. 31 * 32 * Redistribution and use in source and binary forms, with or without modification, 33 * are permitted provided that the following conditions are met: 34 * 35 * 1. Redistributions of source code must retain the above copyright notice, 36 * this list of conditions and the following disclaimer. 37 * 2. Redistributions in binary form must reproduce the above copyright notice, 38 * this list of conditions and the following disclaimer in the documentation 39 * and/or other materials provided with the distribution. 40 * 3. The name of the author may not be used to endorse or promote products 41 * derived from this software without specific prior written permission. 42 * 43 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 44 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 45 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 46 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 47 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 48 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 49 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 50 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 51 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 52 * OF SUCH DAMAGE. 53 * 54 * This file is part of the lwIP TCP/IP stack. 55 * The Swedish Institute of Computer Science and Adam Dunkels 56 * are specifically granted permission to redistribute this 57 * source code. 58 * 59 * Author: Leon Woestenberg <leon.woestenberg@gmx.net> 60 * 61 */ 62 63 #include "lwip/opt.h" 64 65 #if LWIP_IPV4 && LWIP_DHCP /* don't build if not configured for use in lwipopts.h */ 66 67 #include "lwip/stats.h" 68 #include "lwip/mem.h" 69 #include "lwip/udp.h" 70 #include "lwip/ip_addr.h" 71 #include "lwip/netif.h" 72 #include "lwip/def.h" 73 #include "lwip/dhcp.h" 74 #include "lwip/autoip.h" 75 #include "lwip/dns.h" 76 #include "lwip/etharp.h" 77 #include "lwip/prot/dhcp.h" 78 79 #include <string.h> 80 81 /** DHCP_CREATE_RAND_XID: if this is set to 1, the xid is created using 82 * LWIP_RAND() (this overrides DHCP_GLOBAL_XID) 83 */ 84 #ifndef DHCP_CREATE_RAND_XID 85 #define DHCP_CREATE_RAND_XID 1 86 #endif 87 88 /** Default for DHCP_GLOBAL_XID is 0xABCD0000 89 * This can be changed by defining DHCP_GLOBAL_XID and DHCP_GLOBAL_XID_HEADER, e.g. 90 * \#define DHCP_GLOBAL_XID_HEADER "stdlib.h" 91 * \#define DHCP_GLOBAL_XID rand() 92 */ 93 #ifdef DHCP_GLOBAL_XID_HEADER 94 #include DHCP_GLOBAL_XID_HEADER /* include optional starting XID generation prototypes */ 95 #endif 96 97 /** DHCP_OPTION_MAX_MSG_SIZE is set to the MTU 98 * MTU is checked to be big enough in dhcp_start */ 99 #define DHCP_MAX_MSG_LEN(netif) (netif->mtu) 100 #define DHCP_MAX_MSG_LEN_MIN_REQUIRED 576 101 /** Minimum length for reply before packet is parsed */ 102 #define DHCP_MIN_REPLY_LEN 44 103 104 #define REBOOT_TRIES 2 105 106 #if LWIP_DNS && LWIP_DHCP_MAX_DNS_SERVERS 107 #if DNS_MAX_SERVERS > LWIP_DHCP_MAX_DNS_SERVERS 108 #define LWIP_DHCP_PROVIDE_DNS_SERVERS LWIP_DHCP_MAX_DNS_SERVERS 109 #else 110 #define LWIP_DHCP_PROVIDE_DNS_SERVERS DNS_MAX_SERVERS 111 #endif 112 #else 113 #define LWIP_DHCP_PROVIDE_DNS_SERVERS 0 114 #endif 115 116 /** Option handling: options are parsed in dhcp_parse_reply 117 * and saved in an array where other functions can load them from. 118 * This might be moved into the struct dhcp (not necessarily since 119 * lwIP is single-threaded and the array is only used while in recv 120 * callback). */ 121 enum dhcp_option_idx { 122 DHCP_OPTION_IDX_OVERLOAD = 0, 123 DHCP_OPTION_IDX_MSG_TYPE, 124 DHCP_OPTION_IDX_SERVER_ID, 125 DHCP_OPTION_IDX_LEASE_TIME, 126 DHCP_OPTION_IDX_T1, 127 DHCP_OPTION_IDX_T2, 128 DHCP_OPTION_IDX_SUBNET_MASK, 129 DHCP_OPTION_IDX_ROUTER, 130 #if LWIP_DHCP_PROVIDE_DNS_SERVERS 131 DHCP_OPTION_IDX_DNS_SERVER, 132 DHCP_OPTION_IDX_DNS_SERVER_LAST = DHCP_OPTION_IDX_DNS_SERVER + LWIP_DHCP_PROVIDE_DNS_SERVERS - 1, 133 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ 134 #if LWIP_DHCP_GET_NTP_SRV 135 DHCP_OPTION_IDX_NTP_SERVER, 136 DHCP_OPTION_IDX_NTP_SERVER_LAST = DHCP_OPTION_IDX_NTP_SERVER + LWIP_DHCP_MAX_NTP_SERVERS - 1, 137 #endif /* LWIP_DHCP_GET_NTP_SRV */ 138 DHCP_OPTION_IDX_MAX 139 }; 140 141 /** Holds the decoded option values, only valid while in dhcp_recv. 142 @todo: move this into struct dhcp? */ 143 u32_t dhcp_rx_options_val[DHCP_OPTION_IDX_MAX]; 144 /** Holds a flag which option was received and is contained in dhcp_rx_options_val, 145 only valid while in dhcp_recv. 146 @todo: move this into struct dhcp? */ 147 u8_t dhcp_rx_options_given[DHCP_OPTION_IDX_MAX]; 148 149 static u8_t dhcp_discover_request_options[] = { 150 DHCP_OPTION_SUBNET_MASK, 151 DHCP_OPTION_ROUTER, 152 DHCP_OPTION_BROADCAST 153 #if LWIP_DHCP_PROVIDE_DNS_SERVERS 154 , DHCP_OPTION_DNS_SERVER 155 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ 156 #if LWIP_DHCP_GET_NTP_SRV 157 , DHCP_OPTION_NTP 158 #endif /* LWIP_DHCP_GET_NTP_SRV */ 159 }; 160 161 #ifdef DHCP_GLOBAL_XID 162 static u32_t xid; 163 static u8_t xid_initialised; 164 #endif /* DHCP_GLOBAL_XID */ 165 166 #define dhcp_option_given(dhcp, idx) (dhcp_rx_options_given[idx] != 0) 167 #define dhcp_got_option(dhcp, idx) (dhcp_rx_options_given[idx] = 1) 168 #define dhcp_clear_option(dhcp, idx) (dhcp_rx_options_given[idx] = 0) 169 #define dhcp_clear_all_options(dhcp) (memset(dhcp_rx_options_given, 0, sizeof(dhcp_rx_options_given))) 170 #define dhcp_get_option_value(dhcp, idx) (dhcp_rx_options_val[idx]) 171 #define dhcp_set_option_value(dhcp, idx, val) (dhcp_rx_options_val[idx] = (val)) 172 173 static struct udp_pcb *dhcp_pcb; 174 static u8_t dhcp_pcb_refcount; 175 176 /* DHCP client state machine functions */ 177 static err_t dhcp_discover(struct netif *netif); 178 static err_t dhcp_select(struct netif *netif); 179 static void dhcp_bind(struct netif *netif); 180 #if DHCP_DOES_ARP_CHECK 181 static err_t dhcp_decline(struct netif *netif); 182 #endif /* DHCP_DOES_ARP_CHECK */ 183 static err_t dhcp_rebind(struct netif *netif); 184 static err_t dhcp_reboot(struct netif *netif); 185 static void dhcp_set_state(struct dhcp *dhcp, u8_t new_state); 186 187 /* receive, unfold, parse and free incoming messages */ 188 static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port); 189 190 /* set the DHCP timers */ 191 static void dhcp_timeout(struct netif *netif); 192 static void dhcp_t1_timeout(struct netif *netif); 193 static void dhcp_t2_timeout(struct netif *netif); 194 195 /* build outgoing messages */ 196 /* create a DHCP message, fill in common headers */ 197 static err_t dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type); 198 /* free a DHCP request */ 199 static void dhcp_delete_msg(struct dhcp *dhcp); 200 /* add a DHCP option (type, then length in bytes) */ 201 static void dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len); 202 /* add option values */ 203 static void dhcp_option_byte(struct dhcp *dhcp, u8_t value); 204 static void dhcp_option_short(struct dhcp *dhcp, u16_t value); 205 static void dhcp_option_long(struct dhcp *dhcp, u32_t value); 206 #if LWIP_NETIF_HOSTNAME 207 static void dhcp_option_hostname(struct dhcp *dhcp, struct netif *netif); 208 #endif /* LWIP_NETIF_HOSTNAME */ 209 /* always add the DHCP options trailer to end and pad */ 210 static void dhcp_option_trailer(struct dhcp *dhcp); 211 212 /** Ensure DHCP PCB is allocated and bound */ 213 static err_t 214 dhcp_inc_pcb_refcount(void) 215 { 216 if (dhcp_pcb_refcount == 0) { 217 LWIP_ASSERT("dhcp_inc_pcb_refcount(): memory leak", dhcp_pcb == NULL); 218 219 /* allocate UDP PCB */ 220 dhcp_pcb = udp_new(); 221 222 if (dhcp_pcb == NULL) { 223 return ERR_MEM; 224 } 225 226 ip_set_option(dhcp_pcb, SOF_BROADCAST); 227 228 /* set up local and remote port for the pcb -> listen on all interfaces on all src/dest IPs */ 229 udp_bind(dhcp_pcb, IP4_ADDR_ANY, DHCP_CLIENT_PORT); 230 udp_connect(dhcp_pcb, IP4_ADDR_ANY, DHCP_SERVER_PORT); 231 udp_recv(dhcp_pcb, dhcp_recv, NULL); 232 } 233 234 dhcp_pcb_refcount++; 235 236 return ERR_OK; 237 } 238 239 /** Free DHCP PCB if the last netif stops using it */ 240 static void 241 dhcp_dec_pcb_refcount(void) 242 { 243 LWIP_ASSERT("dhcp_pcb_refcount(): refcount error", (dhcp_pcb_refcount > 0)); 244 dhcp_pcb_refcount--; 245 246 if (dhcp_pcb_refcount == 0) { 247 udp_remove(dhcp_pcb); 248 dhcp_pcb = NULL; 249 } 250 } 251 252 /** 253 * Back-off the DHCP client (because of a received NAK response). 254 * 255 * Back-off the DHCP client because of a received NAK. Receiving a 256 * NAK means the client asked for something non-sensible, for 257 * example when it tries to renew a lease obtained on another network. 258 * 259 * We clear any existing set IP address and restart DHCP negotiation 260 * afresh (as per RFC2131 3.2.3). 261 * 262 * @param netif the netif under DHCP control 263 */ 264 static void 265 dhcp_handle_nak(struct netif *netif) 266 { 267 struct dhcp *dhcp = netif_dhcp_data(netif); 268 269 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_nak(netif=%p) %c%c%"U16_F"\n", 270 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); 271 /* Change to a defined state - set this before assigning the address 272 to ensure the callback can use dhcp_supplied_address() */ 273 dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF); 274 /* remove IP address from interface (must no longer be used, as per RFC2131) */ 275 netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4); 276 /* We can immediately restart discovery */ 277 dhcp_discover(netif); 278 } 279 280 #if DHCP_DOES_ARP_CHECK 281 /** 282 * Checks if the offered IP address is already in use. 283 * 284 * It does so by sending an ARP request for the offered address and 285 * entering CHECKING state. If no ARP reply is received within a small 286 * interval, the address is assumed to be free for use by us. 287 * 288 * @param netif the netif under DHCP control 289 */ 290 static void 291 dhcp_check(struct netif *netif) 292 { 293 struct dhcp *dhcp = netif_dhcp_data(netif); 294 err_t result; 295 u16_t msecs; 296 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_check(netif=%p) %c%c\n", (void *)netif, (s16_t)netif->name[0], 297 (s16_t)netif->name[1])); 298 dhcp_set_state(dhcp, DHCP_STATE_CHECKING); 299 /* create an ARP query for the offered IP address, expecting that no host 300 responds, as the IP address should not be in use. */ 301 result = etharp_query(netif, &dhcp->offered_ip_addr, NULL); 302 if (result != ERR_OK) { 303 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_check: could not perform ARP query\n")); 304 } 305 if (dhcp->tries < 255) { 306 dhcp->tries++; 307 } 308 msecs = 500; 309 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 310 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_check(): set request timeout %"U16_F" msecs\n", msecs)); 311 } 312 #endif /* DHCP_DOES_ARP_CHECK */ 313 314 /** 315 * Remember the configuration offered by a DHCP server. 316 * 317 * @param netif the netif under DHCP control 318 */ 319 static void 320 dhcp_handle_offer(struct netif *netif) 321 { 322 struct dhcp *dhcp = netif_dhcp_data(netif); 323 324 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_offer(netif=%p) %c%c%"U16_F"\n", 325 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); 326 /* obtain the server address */ 327 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SERVER_ID)) { 328 ip_addr_set_ip4_u32(&dhcp->server_ip_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SERVER_ID))); 329 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): server 0x%08"X32_F"\n", 330 ip4_addr_get_u32(ip_2_ip4(&dhcp->server_ip_addr)))); 331 /* remember offered address */ 332 ip4_addr_copy(dhcp->offered_ip_addr, dhcp->msg_in->yiaddr); 333 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): offer for 0x%08"X32_F"\n", 334 ip4_addr_get_u32(&dhcp->offered_ip_addr))); 335 336 dhcp_select(netif); 337 } else { 338 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 339 ("dhcp_handle_offer(netif=%p) did not get server ID!\n", (void*)netif)); 340 } 341 } 342 343 /** 344 * Select a DHCP server offer out of all offers. 345 * 346 * Simply select the first offer received. 347 * 348 * @param netif the netif under DHCP control 349 * @return lwIP specific error (see error.h) 350 */ 351 static err_t 352 dhcp_select(struct netif *netif) 353 { 354 struct dhcp *dhcp = netif_dhcp_data(netif); 355 err_t result; 356 u16_t msecs; 357 u8_t i; 358 359 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)); 360 dhcp_set_state(dhcp, DHCP_STATE_REQUESTING); 361 362 /* create and initialize the DHCP message header */ 363 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 364 if (result == ERR_OK) { 365 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 366 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 367 368 /* MUST request the offered IP address */ 369 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 370 dhcp_option_long(dhcp, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); 371 372 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); 373 dhcp_option_long(dhcp, lwip_ntohl(ip4_addr_get_u32(ip_2_ip4(&dhcp->server_ip_addr)))); 374 375 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); 376 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { 377 dhcp_option_byte(dhcp, dhcp_discover_request_options[i]); 378 } 379 380 #if LWIP_NETIF_HOSTNAME 381 dhcp_option_hostname(dhcp, netif); 382 #endif /* LWIP_NETIF_HOSTNAME */ 383 384 dhcp_option_trailer(dhcp); 385 /* shrink the pbuf to the actual content length */ 386 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 387 388 /* send broadcast to any DHCP server */ 389 udp_sendto_if_src(dhcp_pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif, IP4_ADDR_ANY); 390 dhcp_delete_msg(dhcp); 391 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_select: REQUESTING\n")); 392 } else { 393 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_select: could not allocate DHCP request\n")); 394 } 395 if (dhcp->tries < 255) { 396 dhcp->tries++; 397 } 398 msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000; 399 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 400 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_select(): set request timeout %"U16_F" msecs\n", msecs)); 401 return result; 402 } 403 404 /** 405 * The DHCP timer that checks for lease renewal/rebind timeouts. 406 * Must be called once a minute (see @ref DHCP_COARSE_TIMER_SECS). 407 */ 408 void 409 dhcp_coarse_tmr(void) 410 { 411 struct netif *netif; 412 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n")); 413 /* iterate through all network interfaces */ 414 NETIF_FOREACH(netif) { 415 /* only act on DHCP configured interfaces */ 416 struct dhcp *dhcp = netif_dhcp_data(netif); 417 if ((dhcp != NULL) && (dhcp->state != DHCP_STATE_OFF)) { 418 /* compare lease time to expire timeout */ 419 if (dhcp->t0_timeout && (++dhcp->lease_used == dhcp->t0_timeout)) { 420 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t0 timeout\n")); 421 /* this clients' lease time has expired */ 422 dhcp_release(netif); 423 dhcp_discover(netif); 424 /* timer is active (non zero), and triggers (zeroes) now? */ 425 } else if (dhcp->t2_rebind_time && (dhcp->t2_rebind_time-- == 1)) { 426 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t2 timeout\n")); 427 /* this clients' rebind timeout triggered */ 428 dhcp_t2_timeout(netif); 429 /* timer is active (non zero), and triggers (zeroes) now */ 430 } else if (dhcp->t1_renew_time && (dhcp->t1_renew_time-- == 1)) { 431 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t1 timeout\n")); 432 /* this clients' renewal timeout triggered */ 433 dhcp_t1_timeout(netif); 434 } 435 } 436 } 437 } 438 439 /** 440 * DHCP transaction timeout handling (this function must be called every 500ms, 441 * see @ref DHCP_FINE_TIMER_MSECS). 442 * 443 * A DHCP server is expected to respond within a short period of time. 444 * This timer checks whether an outstanding DHCP request is timed out. 445 */ 446 void 447 dhcp_fine_tmr(void) 448 { 449 struct netif *netif; 450 /* loop through netif's */ 451 NETIF_FOREACH(netif) { 452 struct dhcp *dhcp = netif_dhcp_data(netif); 453 /* only act on DHCP configured interfaces */ 454 if (dhcp != NULL) { 455 /* timer is active (non zero), and is about to trigger now */ 456 if (dhcp->request_timeout > 1) { 457 dhcp->request_timeout--; 458 } 459 else if (dhcp->request_timeout == 1) { 460 dhcp->request_timeout--; 461 /* { netif->dhcp->request_timeout == 0 } */ 462 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_fine_tmr(): request timeout\n")); 463 /* this client's request timeout triggered */ 464 dhcp_timeout(netif); 465 } 466 } 467 } 468 } 469 470 /** 471 * A DHCP negotiation transaction, or ARP request, has timed out. 472 * 473 * The timer that was started with the DHCP or ARP request has 474 * timed out, indicating no response was received in time. 475 * 476 * @param netif the netif under DHCP control 477 */ 478 static void 479 dhcp_timeout(struct netif *netif) 480 { 481 struct dhcp *dhcp = netif_dhcp_data(netif); 482 483 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout()\n")); 484 /* back-off period has passed, or server selection timed out */ 485 if ((dhcp->state == DHCP_STATE_BACKING_OFF) || (dhcp->state == DHCP_STATE_SELECTING)) { 486 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout(): restarting discovery\n")); 487 dhcp_discover(netif); 488 /* receiving the requested lease timed out */ 489 } else if (dhcp->state == DHCP_STATE_REQUESTING) { 490 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, DHCP request timed out\n")); 491 if (dhcp->tries <= 5) { 492 dhcp_select(netif); 493 } else { 494 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, releasing, restarting\n")); 495 dhcp_release(netif); 496 dhcp_discover(netif); 497 } 498 #if DHCP_DOES_ARP_CHECK 499 /* received no ARP reply for the offered address (which is good) */ 500 } else if (dhcp->state == DHCP_STATE_CHECKING) { 501 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): CHECKING, ARP request timed out\n")); 502 if (dhcp->tries <= 1) { 503 dhcp_check(netif); 504 /* no ARP replies on the offered address, 505 looks like the IP address is indeed free */ 506 } else { 507 /* bind the interface to the offered address */ 508 dhcp_bind(netif); 509 } 510 #endif /* DHCP_DOES_ARP_CHECK */ 511 } else if (dhcp->state == DHCP_STATE_REBOOTING) { 512 if (dhcp->tries < REBOOT_TRIES) { 513 dhcp_reboot(netif); 514 } else { 515 dhcp_discover(netif); 516 } 517 } 518 } 519 520 /** 521 * The renewal period has timed out. 522 * 523 * @param netif the netif under DHCP control 524 */ 525 static void 526 dhcp_t1_timeout(struct netif *netif) 527 { 528 struct dhcp *dhcp = netif_dhcp_data(netif); 529 530 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_t1_timeout()\n")); 531 if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_BOUND) || 532 (dhcp->state == DHCP_STATE_RENEWING)) { 533 /* just retry to renew - note that the rebind timer (t2) will 534 * eventually time-out if renew tries fail. */ 535 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, 536 ("dhcp_t1_timeout(): must renew\n")); 537 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state 538 DHCP_STATE_RENEWING, not DHCP_STATE_BOUND */ 539 dhcp_renew(netif); 540 /* Calculate next timeout */ 541 if (((dhcp->t2_timeout - dhcp->lease_used) / 2) >= ((60 + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS)) 542 { 543 dhcp->t1_renew_time = ((dhcp->t2_timeout - dhcp->lease_used) / 2); 544 } 545 } 546 } 547 548 /** 549 * The rebind period has timed out. 550 * 551 * @param netif the netif under DHCP control 552 */ 553 static void 554 dhcp_t2_timeout(struct netif *netif) 555 { 556 struct dhcp *dhcp = netif_dhcp_data(netif); 557 558 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t2_timeout()\n")); 559 if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_BOUND) || 560 (dhcp->state == DHCP_STATE_RENEWING) || (dhcp->state == DHCP_STATE_REBINDING)) { 561 /* just retry to rebind */ 562 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, 563 ("dhcp_t2_timeout(): must rebind\n")); 564 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state 565 DHCP_STATE_REBINDING, not DHCP_STATE_BOUND */ 566 dhcp_rebind(netif); 567 /* Calculate next timeout */ 568 if (((dhcp->t0_timeout - dhcp->lease_used) / 2) >= ((60 + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS)) 569 { 570 dhcp->t2_rebind_time = ((dhcp->t0_timeout - dhcp->lease_used) / 2); 571 } 572 } 573 } 574 575 /** 576 * Handle a DHCP ACK packet 577 * 578 * @param netif the netif under DHCP control 579 */ 580 static void 581 dhcp_handle_ack(struct netif *netif) 582 { 583 struct dhcp *dhcp = netif_dhcp_data(netif); 584 585 #if LWIP_DHCP_PROVIDE_DNS_SERVERS || LWIP_DHCP_GET_NTP_SRV 586 u8_t n; 587 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS || LWIP_DHCP_GET_NTP_SRV */ 588 #if LWIP_DHCP_GET_NTP_SRV 589 ip4_addr_t ntp_server_addrs[LWIP_DHCP_MAX_NTP_SERVERS]; 590 #endif 591 592 /* clear options we might not get from the ACK */ 593 ip4_addr_set_zero(&dhcp->offered_sn_mask); 594 ip4_addr_set_zero(&dhcp->offered_gw_addr); 595 #if LWIP_DHCP_BOOTP_FILE 596 ip4_addr_set_zero(&dhcp->offered_si_addr); 597 #endif /* LWIP_DHCP_BOOTP_FILE */ 598 599 /* lease time given? */ 600 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_LEASE_TIME)) { 601 /* remember offered lease time */ 602 dhcp->offered_t0_lease = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_LEASE_TIME); 603 } 604 /* renewal period given? */ 605 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T1)) { 606 /* remember given renewal period */ 607 dhcp->offered_t1_renew = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T1); 608 } else { 609 /* calculate safe periods for renewal */ 610 dhcp->offered_t1_renew = dhcp->offered_t0_lease / 2; 611 } 612 613 /* renewal period given? */ 614 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T2)) { 615 /* remember given rebind period */ 616 dhcp->offered_t2_rebind = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T2); 617 } else { 618 /* calculate safe periods for rebinding (offered_t0_lease * 0.875 -> 87.5%)*/ 619 dhcp->offered_t2_rebind = (dhcp->offered_t0_lease * 7U) / 8U; 620 } 621 622 /* (y)our internet address */ 623 ip4_addr_copy(dhcp->offered_ip_addr, dhcp->msg_in->yiaddr); 624 625 #if LWIP_DHCP_BOOTP_FILE 626 /* copy boot server address, 627 boot file name copied in dhcp_parse_reply if not overloaded */ 628 ip4_addr_copy(dhcp->offered_si_addr, dhcp->msg_in->siaddr); 629 #endif /* LWIP_DHCP_BOOTP_FILE */ 630 631 /* subnet mask given? */ 632 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)) { 633 /* remember given subnet mask */ 634 ip4_addr_set_u32(&dhcp->offered_sn_mask, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SUBNET_MASK))); 635 dhcp->subnet_mask_given = 1; 636 } else { 637 dhcp->subnet_mask_given = 0; 638 } 639 640 /* gateway router */ 641 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_ROUTER)) { 642 ip4_addr_set_u32(&dhcp->offered_gw_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_ROUTER))); 643 } 644 645 #if LWIP_DHCP_GET_NTP_SRV 646 /* NTP servers */ 647 for (n = 0; (n < LWIP_DHCP_MAX_NTP_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_NTP_SERVER + n); n++) { 648 ip4_addr_set_u32(&ntp_server_addrs[n], lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_NTP_SERVER + n))); 649 } 650 dhcp_set_ntp_servers(n, ntp_server_addrs); 651 #endif /* LWIP_DHCP_GET_NTP_SRV */ 652 653 #if LWIP_DHCP_PROVIDE_DNS_SERVERS 654 /* DNS servers */ 655 for (n = 0; (n < LWIP_DHCP_PROVIDE_DNS_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n); n++) { 656 ip_addr_t dns_addr; 657 ip_addr_set_ip4_u32(&dns_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n))); 658 dns_setserver(n, &dns_addr); 659 } 660 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ 661 } 662 663 /** 664 * @ingroup dhcp4 665 * Set a statically allocated struct dhcp to work with. 666 * Using this prevents dhcp_start to allocate it using mem_malloc. 667 * 668 * @param netif the netif for which to set the struct dhcp 669 * @param dhcp (uninitialised) dhcp struct allocated by the application 670 */ 671 void 672 dhcp_set_struct(struct netif *netif, struct dhcp *dhcp) 673 { 674 LWIP_ASSERT("netif != NULL", netif != NULL); 675 LWIP_ASSERT("dhcp != NULL", dhcp != NULL); 676 LWIP_ASSERT("netif already has a struct dhcp set", netif_dhcp_data(netif) == NULL); 677 678 /* clear data structure */ 679 memset(dhcp, 0, sizeof(struct dhcp)); 680 /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */ 681 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp); 682 } 683 684 /** 685 * @ingroup dhcp4 686 * Removes a struct dhcp from a netif. 687 * 688 * ATTENTION: Only use this when not using dhcp_set_struct() to allocate the 689 * struct dhcp since the memory is passed back to the heap. 690 * 691 * @param netif the netif from which to remove the struct dhcp 692 */ 693 void dhcp_cleanup(struct netif *netif) 694 { 695 LWIP_ASSERT("netif != NULL", netif != NULL); 696 697 if (netif_dhcp_data(netif) != NULL) { 698 mem_free(netif_dhcp_data(netif)); 699 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, NULL); 700 } 701 } 702 703 /** 704 * @ingroup dhcp4 705 * Start DHCP negotiation for a network interface. 706 * 707 * If no DHCP client instance was attached to this interface, 708 * a new client is created first. If a DHCP client instance 709 * was already present, it restarts negotiation. 710 * 711 * @param netif The lwIP network interface 712 * @return lwIP error code 713 * - ERR_OK - No error 714 * - ERR_MEM - Out of memory 715 */ 716 err_t 717 dhcp_start(struct netif *netif) 718 { 719 struct dhcp *dhcp; 720 err_t result; 721 722 LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;); 723 LWIP_ERROR("netif is not up, old style port?", netif_is_up(netif), return ERR_ARG;); 724 dhcp = netif_dhcp_data(netif); 725 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)); 726 727 /* check MTU of the netif */ 728 if (netif->mtu < DHCP_MAX_MSG_LEN_MIN_REQUIRED) { 729 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): Cannot use this netif with DHCP: MTU is too small\n")); 730 return ERR_MEM; 731 } 732 733 /* no DHCP client attached yet? */ 734 if (dhcp == NULL) { 735 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting new DHCP client\n")); 736 dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp)); 737 if (dhcp == NULL) { 738 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n")); 739 return ERR_MEM; 740 } 741 742 /* store this dhcp client in the netif */ 743 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp); 744 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): allocated dhcp")); 745 /* already has DHCP client attached */ 746 } else { 747 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(): restarting DHCP configuration\n")); 748 LWIP_ASSERT("pbuf p_out wasn't freed", dhcp->p_out == NULL); 749 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL ); 750 751 if (dhcp->pcb_allocated != 0) { 752 dhcp_dec_pcb_refcount(); /* free DHCP PCB if not needed any more */ 753 } 754 /* dhcp is cleared below, no need to reset flag*/ 755 } 756 757 /* clear data structure */ 758 memset(dhcp, 0, sizeof(struct dhcp)); 759 /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */ 760 761 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n")); 762 763 if (dhcp_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP PCB is allocated */ 764 return ERR_MEM; 765 } 766 dhcp->pcb_allocated = 1; 767 768 #if LWIP_DHCP_CHECK_LINK_UP 769 if (!netif_is_link_up(netif)) { 770 /* set state INIT and wait for dhcp_network_changed() to call dhcp_discover() */ 771 dhcp_set_state(dhcp, DHCP_STATE_INIT); 772 return ERR_OK; 773 } 774 #endif /* LWIP_DHCP_CHECK_LINK_UP */ 775 776 777 /* (re)start the DHCP negotiation */ 778 result = dhcp_discover(netif); 779 if (result != ERR_OK) { 780 /* free resources allocated above */ 781 dhcp_stop(netif); 782 return ERR_MEM; 783 } 784 return result; 785 } 786 787 /** 788 * @ingroup dhcp4 789 * Inform a DHCP server of our manual configuration. 790 * 791 * This informs DHCP servers of our fixed IP address configuration 792 * by sending an INFORM message. It does not involve DHCP address 793 * configuration, it is just here to be nice to the network. 794 * 795 * @param netif The lwIP network interface 796 */ 797 void 798 dhcp_inform(struct netif *netif) 799 { 800 struct dhcp dhcp; 801 err_t result = ERR_OK; 802 803 LWIP_ERROR("netif != NULL", (netif != NULL), return;); 804 805 if (dhcp_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP PCB is allocated */ 806 return; 807 } 808 809 memset(&dhcp, 0, sizeof(struct dhcp)); 810 dhcp_set_state(&dhcp, DHCP_STATE_INFORMING); 811 812 /* create and initialize the DHCP message header */ 813 result = dhcp_create_msg(netif, &dhcp, DHCP_INFORM); 814 if (result == ERR_OK) { 815 dhcp_option(&dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 816 dhcp_option_short(&dhcp, DHCP_MAX_MSG_LEN(netif)); 817 818 dhcp_option_trailer(&dhcp); 819 820 pbuf_realloc(dhcp.p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp.options_out_len); 821 822 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n")); 823 824 udp_sendto_if(dhcp_pcb, dhcp.p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 825 826 dhcp_delete_msg(&dhcp); 827 } else { 828 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform: could not allocate DHCP request\n")); 829 } 830 831 dhcp_dec_pcb_refcount(); /* delete DHCP PCB if not needed any more */ 832 } 833 834 /** Handle a possible change in the network configuration. 835 * 836 * This enters the REBOOTING state to verify that the currently bound 837 * address is still valid. 838 */ 839 void 840 dhcp_network_changed(struct netif *netif) 841 { 842 struct dhcp *dhcp = netif_dhcp_data(netif); 843 844 if (!dhcp) { 845 return; 846 } 847 switch (dhcp->state) { 848 case DHCP_STATE_REBINDING: 849 case DHCP_STATE_RENEWING: 850 case DHCP_STATE_BOUND: 851 case DHCP_STATE_REBOOTING: 852 dhcp->tries = 0; 853 dhcp_reboot(netif); 854 break; 855 case DHCP_STATE_OFF: 856 /* stay off */ 857 break; 858 default: 859 LWIP_ASSERT("invalid dhcp->state", dhcp->state <= DHCP_STATE_BACKING_OFF); 860 /* INIT/REQUESTING/CHECKING/BACKING_OFF restart with new 'rid' because the 861 state changes, SELECTING: continue with current 'rid' as we stay in the 862 same state */ 863 #if LWIP_DHCP_AUTOIP_COOP 864 if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { 865 autoip_stop(netif); 866 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; 867 } 868 #endif /* LWIP_DHCP_AUTOIP_COOP */ 869 /* ensure we start with short timeouts, even if already discovering */ 870 dhcp->tries = 0; 871 dhcp_discover(netif); 872 break; 873 } 874 } 875 876 #if DHCP_DOES_ARP_CHECK 877 /** 878 * Match an ARP reply with the offered IP address: 879 * check whether the offered IP address is not in use using ARP 880 * 881 * @param netif the network interface on which the reply was received 882 * @param addr The IP address we received a reply from 883 */ 884 void 885 dhcp_arp_reply(struct netif *netif, const ip4_addr_t *addr) 886 { 887 struct dhcp *dhcp; 888 889 LWIP_ERROR("netif != NULL", (netif != NULL), return;); 890 dhcp = netif_dhcp_data(netif); 891 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_arp_reply()\n")); 892 /* is a DHCP client doing an ARP check? */ 893 if ((dhcp != NULL) && (dhcp->state == DHCP_STATE_CHECKING)) { 894 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_arp_reply(): CHECKING, arp reply for 0x%08"X32_F"\n", 895 ip4_addr_get_u32(addr))); 896 /* did a host respond with the address we 897 were offered by the DHCP server? */ 898 if (ip4_addr_cmp(addr, &dhcp->offered_ip_addr)) { 899 /* we will not accept the offered address */ 900 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING, 901 ("dhcp_arp_reply(): arp reply matched with offered address, declining\n")); 902 dhcp_decline(netif); 903 } 904 } 905 } 906 907 /** 908 * Decline an offered lease. 909 * 910 * Tell the DHCP server we do not accept the offered address. 911 * One reason to decline the lease is when we find out the address 912 * is already in use by another host (through ARP). 913 * 914 * @param netif the netif under DHCP control 915 */ 916 static err_t 917 dhcp_decline(struct netif *netif) 918 { 919 struct dhcp *dhcp = netif_dhcp_data(netif); 920 err_t result = ERR_OK; 921 u16_t msecs; 922 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline()\n")); 923 dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF); 924 /* create and initialize the DHCP message header */ 925 result = dhcp_create_msg(netif, dhcp, DHCP_DECLINE); 926 if (result == ERR_OK) { 927 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 928 dhcp_option_long(dhcp, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); 929 930 dhcp_option_trailer(dhcp); 931 /* resize pbuf to reflect true size of options */ 932 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 933 934 /* per section 4.4.4, broadcast DECLINE messages */ 935 udp_sendto_if_src(dhcp_pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif, IP4_ADDR_ANY); 936 dhcp_delete_msg(dhcp); 937 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_decline: BACKING OFF\n")); 938 } else { 939 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 940 ("dhcp_decline: could not allocate DHCP request\n")); 941 } 942 if (dhcp->tries < 255) { 943 dhcp->tries++; 944 } 945 msecs = 10*1000; 946 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 947 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs)); 948 return result; 949 } 950 #endif /* DHCP_DOES_ARP_CHECK */ 951 952 953 /** 954 * Start the DHCP process, discover a DHCP server. 955 * 956 * @param netif the netif under DHCP control 957 */ 958 static err_t 959 dhcp_discover(struct netif *netif) 960 { 961 struct dhcp *dhcp = netif_dhcp_data(netif); 962 err_t result = ERR_OK; 963 u16_t msecs; 964 u8_t i; 965 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover()\n")); 966 ip4_addr_set_any(&dhcp->offered_ip_addr); 967 dhcp_set_state(dhcp, DHCP_STATE_SELECTING); 968 /* create and initialize the DHCP message header */ 969 result = dhcp_create_msg(netif, dhcp, DHCP_DISCOVER); 970 if (result == ERR_OK) { 971 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n")); 972 973 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 974 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 975 976 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); 977 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { 978 dhcp_option_byte(dhcp, dhcp_discover_request_options[i]); 979 } 980 dhcp_option_trailer(dhcp); 981 982 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: realloc()ing\n")); 983 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 984 985 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, DHCP_SERVER_PORT)\n")); 986 udp_sendto_if_src(dhcp_pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif, IP4_ADDR_ANY); 987 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()ing\n")); 988 dhcp_delete_msg(dhcp); 989 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover: SELECTING\n")); 990 } else { 991 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_discover: could not allocate DHCP request\n")); 992 } 993 if (dhcp->tries < 255) { 994 dhcp->tries++; 995 } 996 #if LWIP_DHCP_AUTOIP_COOP 997 if (dhcp->tries >= LWIP_DHCP_AUTOIP_COOP_TRIES && dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_OFF) { 998 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_ON; 999 autoip_start(netif); 1000 } 1001 #endif /* LWIP_DHCP_AUTOIP_COOP */ 1002 msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000; 1003 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 1004 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs)); 1005 return result; 1006 } 1007 1008 1009 /** 1010 * Bind the interface to the offered IP address. 1011 * 1012 * @param netif network interface to bind to the offered address 1013 */ 1014 static void 1015 dhcp_bind(struct netif *netif) 1016 { 1017 u32_t timeout; 1018 struct dhcp *dhcp; 1019 ip4_addr_t sn_mask, gw_addr; 1020 LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;); 1021 dhcp = netif_dhcp_data(netif); 1022 LWIP_ERROR("dhcp_bind: dhcp != NULL", (dhcp != NULL), return;); 1023 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)); 1024 1025 /* reset time used of lease */ 1026 dhcp->lease_used = 0; 1027 1028 if (dhcp->offered_t0_lease != 0xffffffffUL) { 1029 /* set renewal period timer */ 1030 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t0 renewal timer %"U32_F" secs\n", dhcp->offered_t0_lease)); 1031 timeout = (dhcp->offered_t0_lease + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; 1032 if (timeout > 0xffff) { 1033 timeout = 0xffff; 1034 } 1035 dhcp->t0_timeout = (u16_t)timeout; 1036 if (dhcp->t0_timeout == 0) { 1037 dhcp->t0_timeout = 1; 1038 } 1039 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t0_lease*1000)); 1040 } 1041 1042 /* temporary DHCP lease? */ 1043 if (dhcp->offered_t1_renew != 0xffffffffUL) { 1044 /* set renewal period timer */ 1045 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew)); 1046 timeout = (dhcp->offered_t1_renew + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; 1047 if (timeout > 0xffff) { 1048 timeout = 0xffff; 1049 } 1050 dhcp->t1_timeout = (u16_t)timeout; 1051 if (dhcp->t1_timeout == 0) { 1052 dhcp->t1_timeout = 1; 1053 } 1054 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew*1000)); 1055 dhcp->t1_renew_time = dhcp->t1_timeout; 1056 } 1057 /* set renewal period timer */ 1058 if (dhcp->offered_t2_rebind != 0xffffffffUL) { 1059 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind)); 1060 timeout = (dhcp->offered_t2_rebind + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; 1061 if (timeout > 0xffff) { 1062 timeout = 0xffff; 1063 } 1064 dhcp->t2_timeout = (u16_t)timeout; 1065 if (dhcp->t2_timeout == 0) { 1066 dhcp->t2_timeout = 1; 1067 } 1068 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t2_rebind*1000)); 1069 dhcp->t2_rebind_time = dhcp->t2_timeout; 1070 } 1071 1072 /* If we have sub 1 minute lease, t2 and t1 will kick in at the same time. */ 1073 if ((dhcp->t1_timeout >= dhcp->t2_timeout) && (dhcp->t2_timeout > 0)) { 1074 dhcp->t1_timeout = 0; 1075 } 1076 1077 if (dhcp->subnet_mask_given) { 1078 /* copy offered network mask */ 1079 ip4_addr_copy(sn_mask, dhcp->offered_sn_mask); 1080 } else { 1081 /* subnet mask not given, choose a safe subnet mask given the network class */ 1082 u8_t first_octet = ip4_addr1(&dhcp->offered_ip_addr); 1083 if (first_octet <= 127) { 1084 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xff000000UL)); 1085 } else if (first_octet >= 192) { 1086 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffffff00UL)); 1087 } else { 1088 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffff0000UL)); 1089 } 1090 } 1091 1092 ip4_addr_copy(gw_addr, dhcp->offered_gw_addr); 1093 /* gateway address not given? */ 1094 if (ip4_addr_isany_val(gw_addr)) { 1095 /* copy network address */ 1096 ip4_addr_get_network(&gw_addr, &dhcp->offered_ip_addr, &sn_mask); 1097 /* use first host address on network as gateway */ 1098 ip4_addr_set_u32(&gw_addr, ip4_addr_get_u32(&gw_addr) | PP_HTONL(0x00000001UL)); 1099 } 1100 1101 #if LWIP_DHCP_AUTOIP_COOP 1102 if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { 1103 autoip_stop(netif); 1104 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; 1105 } 1106 #endif /* LWIP_DHCP_AUTOIP_COOP */ 1107 1108 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", 1109 ip4_addr_get_u32(&dhcp->offered_ip_addr), ip4_addr_get_u32(&sn_mask), ip4_addr_get_u32(&gw_addr))); 1110 /* netif is now bound to DHCP leased address - set this before assigning the address 1111 to ensure the callback can use dhcp_supplied_address() */ 1112 dhcp_set_state(dhcp, DHCP_STATE_BOUND); 1113 1114 netif_set_addr(netif, &dhcp->offered_ip_addr, &sn_mask, &gw_addr); 1115 /* interface is used by routing now that an address is set */ 1116 } 1117 1118 /** 1119 * @ingroup dhcp4 1120 * Renew an existing DHCP lease at the involved DHCP server. 1121 * 1122 * @param netif network interface which must renew its lease 1123 */ 1124 err_t 1125 dhcp_renew(struct netif *netif) 1126 { 1127 struct dhcp *dhcp = netif_dhcp_data(netif); 1128 err_t result; 1129 u16_t msecs; 1130 u8_t i; 1131 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_renew()\n")); 1132 dhcp_set_state(dhcp, DHCP_STATE_RENEWING); 1133 1134 /* create and initialize the DHCP message header */ 1135 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 1136 if (result == ERR_OK) { 1137 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 1138 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 1139 1140 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); 1141 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { 1142 dhcp_option_byte(dhcp, dhcp_discover_request_options[i]); 1143 } 1144 1145 #if LWIP_NETIF_HOSTNAME 1146 dhcp_option_hostname(dhcp, netif); 1147 #endif /* LWIP_NETIF_HOSTNAME */ 1148 1149 /* append DHCP message trailer */ 1150 dhcp_option_trailer(dhcp); 1151 1152 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 1153 1154 udp_sendto_if(dhcp_pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif); 1155 dhcp_delete_msg(dhcp); 1156 1157 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew: RENEWING\n")); 1158 } else { 1159 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_renew: could not allocate DHCP request\n")); 1160 } 1161 if (dhcp->tries < 255) { 1162 dhcp->tries++; 1163 } 1164 /* back-off on retries, but to a maximum of 20 seconds */ 1165 msecs = dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000; 1166 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 1167 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs)); 1168 return result; 1169 } 1170 1171 /** 1172 * Rebind with a DHCP server for an existing DHCP lease. 1173 * 1174 * @param netif network interface which must rebind with a DHCP server 1175 */ 1176 static err_t 1177 dhcp_rebind(struct netif *netif) 1178 { 1179 struct dhcp *dhcp = netif_dhcp_data(netif); 1180 err_t result; 1181 u16_t msecs; 1182 u8_t i; 1183 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n")); 1184 dhcp_set_state(dhcp, DHCP_STATE_REBINDING); 1185 1186 /* create and initialize the DHCP message header */ 1187 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 1188 if (result == ERR_OK) { 1189 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 1190 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 1191 1192 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); 1193 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { 1194 dhcp_option_byte(dhcp, dhcp_discover_request_options[i]); 1195 } 1196 1197 #if LWIP_NETIF_HOSTNAME 1198 dhcp_option_hostname(dhcp, netif); 1199 #endif /* LWIP_NETIF_HOSTNAME */ 1200 1201 dhcp_option_trailer(dhcp); 1202 1203 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 1204 1205 /* broadcast to server */ 1206 udp_sendto_if(dhcp_pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 1207 dhcp_delete_msg(dhcp); 1208 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n")); 1209 } else { 1210 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_rebind: could not allocate DHCP request\n")); 1211 } 1212 if (dhcp->tries < 255) { 1213 dhcp->tries++; 1214 } 1215 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; 1216 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 1217 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs)); 1218 return result; 1219 } 1220 1221 /** 1222 * Enter REBOOTING state to verify an existing lease 1223 * 1224 * @param netif network interface which must reboot 1225 */ 1226 static err_t 1227 dhcp_reboot(struct netif *netif) 1228 { 1229 struct dhcp *dhcp = netif_dhcp_data(netif); 1230 err_t result; 1231 u16_t msecs; 1232 u8_t i; 1233 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n")); 1234 dhcp_set_state(dhcp, DHCP_STATE_REBOOTING); 1235 1236 /* create and initialize the DHCP message header */ 1237 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 1238 if (result == ERR_OK) { 1239 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 1240 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN_MIN_REQUIRED); 1241 1242 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 1243 dhcp_option_long(dhcp, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); 1244 1245 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); 1246 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { 1247 dhcp_option_byte(dhcp, dhcp_discover_request_options[i]); 1248 } 1249 1250 dhcp_option_trailer(dhcp); 1251 1252 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 1253 1254 /* broadcast to server */ 1255 udp_sendto_if(dhcp_pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 1256 dhcp_delete_msg(dhcp); 1257 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot: REBOOTING\n")); 1258 } else { 1259 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_reboot: could not allocate DHCP request\n")); 1260 } 1261 if (dhcp->tries < 255) { 1262 dhcp->tries++; 1263 } 1264 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; 1265 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 1266 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot(): set request timeout %"U16_F" msecs\n", msecs)); 1267 return result; 1268 } 1269 1270 /** 1271 * @ingroup dhcp4 1272 * Release a DHCP lease and stop DHCP statemachine (and AUTOIP if LWIP_DHCP_AUTOIP_COOP). 1273 * 1274 * @param netif network interface 1275 */ 1276 void 1277 dhcp_release_and_stop(struct netif *netif) 1278 { 1279 struct dhcp *dhcp = netif_dhcp_data(netif); 1280 ip_addr_t server_ip_addr; 1281 1282 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release_and_stop()\n")); 1283 if (dhcp == NULL) { 1284 return; 1285 } 1286 1287 /* already off? -> nothing to do */ 1288 if (dhcp->state == DHCP_STATE_OFF) { 1289 return; 1290 } 1291 1292 ip_addr_copy(server_ip_addr, dhcp->server_ip_addr); 1293 1294 /* clean old DHCP offer */ 1295 ip_addr_set_zero_ip4(&dhcp->server_ip_addr); 1296 ip4_addr_set_zero(&dhcp->offered_ip_addr); 1297 ip4_addr_set_zero(&dhcp->offered_sn_mask); 1298 ip4_addr_set_zero(&dhcp->offered_gw_addr); 1299 #if LWIP_DHCP_BOOTP_FILE 1300 ip4_addr_set_zero(&dhcp->offered_si_addr); 1301 #endif /* LWIP_DHCP_BOOTP_FILE */ 1302 dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0; 1303 dhcp->t1_renew_time = dhcp->t2_rebind_time = dhcp->lease_used = dhcp->t0_timeout = 0; 1304 1305 /* send release message when current IP was assigned via DHCP */ 1306 if (dhcp_supplied_address(netif)) { 1307 /* create and initialize the DHCP message header */ 1308 err_t result = dhcp_create_msg(netif, dhcp, DHCP_RELEASE); 1309 if (result == ERR_OK) { 1310 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); 1311 dhcp_option_long(dhcp, lwip_ntohl(ip4_addr_get_u32(ip_2_ip4(&server_ip_addr)))); 1312 1313 dhcp_option_trailer(dhcp); 1314 1315 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 1316 1317 udp_sendto_if(dhcp_pcb, dhcp->p_out, &server_ip_addr, DHCP_SERVER_PORT, netif); 1318 dhcp_delete_msg(dhcp); 1319 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_STATE_OFF\n")); 1320 } else { 1321 /* sending release failed, but that's not a problem since the correct behaviour of dhcp does not rely on release */ 1322 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n")); 1323 } 1324 } 1325 1326 /* remove IP address from interface (prevents routing from selecting this interface) */ 1327 netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4); 1328 1329 #if LWIP_DHCP_AUTOIP_COOP 1330 if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { 1331 autoip_stop(netif); 1332 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; 1333 } 1334 #endif /* LWIP_DHCP_AUTOIP_COOP */ 1335 1336 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL); 1337 dhcp_set_state(dhcp, DHCP_STATE_OFF); 1338 1339 if (dhcp->pcb_allocated != 0) { 1340 dhcp_dec_pcb_refcount(); /* free DHCP PCB if not needed any more */ 1341 dhcp->pcb_allocated = 0; 1342 } 1343 } 1344 1345 /** 1346 * @ingroup dhcp4 1347 * @deprecated Use dhcp_release_and_stop() instead. 1348 * This function calls dhcp_release_and_stop() internally. 1349 */ 1350 err_t 1351 dhcp_release(struct netif *netif) 1352 { 1353 dhcp_release_and_stop(netif); 1354 return ERR_OK; 1355 } 1356 1357 /** 1358 * @ingroup dhcp4 1359 * @deprecated Use dhcp_release_and_stop() instead. 1360 * This function calls dhcp_release_and_stop() internally. 1361 */ 1362 void 1363 dhcp_stop(struct netif *netif) 1364 { 1365 dhcp_release_and_stop(netif); 1366 } 1367 1368 /* 1369 * Set the DHCP state of a DHCP client. 1370 * 1371 * If the state changed, reset the number of tries. 1372 */ 1373 static void 1374 dhcp_set_state(struct dhcp *dhcp, u8_t new_state) 1375 { 1376 if (new_state != dhcp->state) { 1377 dhcp->state = new_state; 1378 dhcp->tries = 0; 1379 dhcp->request_timeout = 0; 1380 } 1381 } 1382 1383 /* 1384 * Concatenate an option type and length field to the outgoing 1385 * DHCP message. 1386 * 1387 */ 1388 static void 1389 dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len) 1390 { 1391 LWIP_ASSERT("dhcp_option: dhcp->options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN); 1392 dhcp->msg_out->options[dhcp->options_out_len++] = option_type; 1393 dhcp->msg_out->options[dhcp->options_out_len++] = option_len; 1394 } 1395 /* 1396 * Concatenate a single byte to the outgoing DHCP message. 1397 * 1398 */ 1399 static void 1400 dhcp_option_byte(struct dhcp *dhcp, u8_t value) 1401 { 1402 LWIP_ASSERT("dhcp_option_byte: dhcp->options_out_len < DHCP_OPTIONS_LEN", dhcp->options_out_len < DHCP_OPTIONS_LEN); 1403 dhcp->msg_out->options[dhcp->options_out_len++] = value; 1404 } 1405 1406 static void 1407 dhcp_option_short(struct dhcp *dhcp, u16_t value) 1408 { 1409 LWIP_ASSERT("dhcp_option_short: dhcp->options_out_len + 2 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U <= DHCP_OPTIONS_LEN); 1410 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff00U) >> 8); 1411 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t) (value & 0x00ffU); 1412 } 1413 1414 static void 1415 dhcp_option_long(struct dhcp *dhcp, u32_t value) 1416 { 1417 LWIP_ASSERT("dhcp_option_long: dhcp->options_out_len + 4 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 4U <= DHCP_OPTIONS_LEN); 1418 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24); 1419 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16); 1420 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8); 1421 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x000000ffUL)); 1422 } 1423 1424 #if LWIP_NETIF_HOSTNAME 1425 static void 1426 dhcp_option_hostname(struct dhcp *dhcp, struct netif *netif) 1427 { 1428 if (netif->hostname != NULL) { 1429 size_t namelen = strlen(netif->hostname); 1430 if (namelen > 0) { 1431 size_t len; 1432 const char *p = netif->hostname; 1433 /* Shrink len to available bytes (need 2 bytes for OPTION_HOSTNAME 1434 and 1 byte for trailer) */ 1435 size_t available = DHCP_OPTIONS_LEN - dhcp->options_out_len - 3; 1436 LWIP_ASSERT("DHCP: hostname is too long!", namelen <= available); 1437 len = LWIP_MIN(namelen, available); 1438 LWIP_ASSERT("DHCP: hostname is too long!", len <= 0xFF); 1439 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, (u8_t)len); 1440 while (len--) { 1441 dhcp_option_byte(dhcp, *p++); 1442 } 1443 } 1444 } 1445 } 1446 #endif /* LWIP_NETIF_HOSTNAME */ 1447 1448 /** 1449 * Extract the DHCP message and the DHCP options. 1450 * 1451 * Extract the DHCP message and the DHCP options, each into a contiguous 1452 * piece of memory. As a DHCP message is variable sized by its options, 1453 * and also allows overriding some fields for options, the easy approach 1454 * is to first unfold the options into a contiguous piece of memory, and 1455 * use that further on. 1456 * 1457 */ 1458 static err_t 1459 dhcp_parse_reply(struct dhcp *dhcp, struct pbuf *p) 1460 { 1461 u8_t *options; 1462 u16_t offset; 1463 u16_t offset_max; 1464 u16_t options_idx; 1465 u16_t options_idx_max; 1466 struct pbuf *q; 1467 int parse_file_as_options = 0; 1468 int parse_sname_as_options = 0; 1469 1470 /* clear received options */ 1471 dhcp_clear_all_options(dhcp); 1472 /* check that beginning of dhcp_msg (up to and including chaddr) is in first pbuf */ 1473 if (p->len < DHCP_SNAME_OFS) { 1474 return ERR_BUF; 1475 } 1476 dhcp->msg_in = (struct dhcp_msg *)p->payload; 1477 #if LWIP_DHCP_BOOTP_FILE 1478 /* clear boot file name */ 1479 dhcp->boot_file_name[0] = 0; 1480 #endif /* LWIP_DHCP_BOOTP_FILE */ 1481 1482 /* parse options */ 1483 1484 /* start with options field */ 1485 options_idx = DHCP_OPTIONS_OFS; 1486 /* parse options to the end of the received packet */ 1487 options_idx_max = p->tot_len; 1488 again: 1489 q = p; 1490 while ((q != NULL) && (options_idx >= q->len)) { 1491 options_idx -= q->len; 1492 options_idx_max -= q->len; 1493 q = q->next; 1494 } 1495 if (q == NULL) { 1496 return ERR_BUF; 1497 } 1498 offset = options_idx; 1499 offset_max = options_idx_max; 1500 options = (u8_t*)q->payload; 1501 /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */ 1502 while ((q != NULL) && (options[offset] != DHCP_OPTION_END) && (offset < offset_max)) { 1503 u8_t op = options[offset]; 1504 u8_t len; 1505 u8_t decode_len = 0; 1506 int decode_idx = -1; 1507 u16_t val_offset = offset + 2; 1508 /* len byte might be in the next pbuf */ 1509 if ((offset + 1) < q->len) { 1510 len = options[offset + 1]; 1511 } else { 1512 len = (q->next != NULL ? ((u8_t*)q->next->payload)[0] : 0); 1513 } 1514 /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F, msg_offset, q->len)); */ 1515 decode_len = len; 1516 switch(op) { 1517 /* case(DHCP_OPTION_END): handled above */ 1518 case(DHCP_OPTION_PAD): 1519 /* special option: no len encoded */ 1520 decode_len = len = 0; 1521 /* will be increased below */ 1522 offset--; 1523 break; 1524 case(DHCP_OPTION_SUBNET_MASK): 1525 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); 1526 decode_idx = DHCP_OPTION_IDX_SUBNET_MASK; 1527 break; 1528 case(DHCP_OPTION_ROUTER): 1529 decode_len = 4; /* only copy the first given router */ 1530 LWIP_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;); 1531 decode_idx = DHCP_OPTION_IDX_ROUTER; 1532 break; 1533 #if LWIP_DHCP_PROVIDE_DNS_SERVERS 1534 case(DHCP_OPTION_DNS_SERVER): 1535 /* special case: there might be more than one server */ 1536 LWIP_ERROR("len %% 4 == 0", len % 4 == 0, return ERR_VAL;); 1537 /* limit number of DNS servers */ 1538 decode_len = LWIP_MIN(len, 4 * DNS_MAX_SERVERS); 1539 LWIP_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;); 1540 decode_idx = DHCP_OPTION_IDX_DNS_SERVER; 1541 break; 1542 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ 1543 case(DHCP_OPTION_LEASE_TIME): 1544 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); 1545 decode_idx = DHCP_OPTION_IDX_LEASE_TIME; 1546 break; 1547 #if LWIP_DHCP_GET_NTP_SRV 1548 case(DHCP_OPTION_NTP): 1549 /* special case: there might be more than one server */ 1550 LWIP_ERROR("len %% 4 == 0", len % 4 == 0, return ERR_VAL;); 1551 /* limit number of NTP servers */ 1552 decode_len = LWIP_MIN(len, 4 * LWIP_DHCP_MAX_NTP_SERVERS); 1553 LWIP_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;); 1554 decode_idx = DHCP_OPTION_IDX_NTP_SERVER; 1555 break; 1556 #endif /* LWIP_DHCP_GET_NTP_SRV*/ 1557 case(DHCP_OPTION_OVERLOAD): 1558 LWIP_ERROR("len == 1", len == 1, return ERR_VAL;); 1559 /* decode overload only in options, not in file/sname: invalid packet */ 1560 LWIP_ERROR("overload in file/sname", options_idx == DHCP_OPTIONS_OFS, return ERR_VAL;); 1561 decode_idx = DHCP_OPTION_IDX_OVERLOAD; 1562 break; 1563 case(DHCP_OPTION_MESSAGE_TYPE): 1564 LWIP_ERROR("len == 1", len == 1, return ERR_VAL;); 1565 decode_idx = DHCP_OPTION_IDX_MSG_TYPE; 1566 break; 1567 case(DHCP_OPTION_SERVER_ID): 1568 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); 1569 decode_idx = DHCP_OPTION_IDX_SERVER_ID; 1570 break; 1571 case(DHCP_OPTION_T1): 1572 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); 1573 decode_idx = DHCP_OPTION_IDX_T1; 1574 break; 1575 case(DHCP_OPTION_T2): 1576 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); 1577 decode_idx = DHCP_OPTION_IDX_T2; 1578 break; 1579 default: 1580 decode_len = 0; 1581 LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", (u16_t)op)); 1582 break; 1583 } 1584 offset += len + 2; 1585 if (decode_len > 0) { 1586 u32_t value = 0; 1587 u16_t copy_len; 1588 decode_next: 1589 LWIP_ASSERT("check decode_idx", decode_idx >= 0 && decode_idx < DHCP_OPTION_IDX_MAX); 1590 if (!dhcp_option_given(dhcp, decode_idx)) { 1591 copy_len = LWIP_MIN(decode_len, 4); 1592 if (pbuf_copy_partial(q, &value, copy_len, val_offset) != copy_len) { 1593 return ERR_BUF; 1594 } 1595 if (decode_len > 4) { 1596 /* decode more than one u32_t */ 1597 LWIP_ERROR("decode_len %% 4 == 0", decode_len % 4 == 0, return ERR_VAL;); 1598 dhcp_got_option(dhcp, decode_idx); 1599 dhcp_set_option_value(dhcp, decode_idx, lwip_htonl(value)); 1600 decode_len -= 4; 1601 val_offset += 4; 1602 decode_idx++; 1603 goto decode_next; 1604 } else if (decode_len == 4) { 1605 value = lwip_ntohl(value); 1606 } else { 1607 LWIP_ERROR("invalid decode_len", decode_len == 1, return ERR_VAL;); 1608 value = ((u8_t*)&value)[0]; 1609 } 1610 dhcp_got_option(dhcp, decode_idx); 1611 dhcp_set_option_value(dhcp, decode_idx, value); 1612 } 1613 } 1614 if (offset >= q->len) { 1615 offset -= q->len; 1616 offset_max -= q->len; 1617 if ((offset < offset_max) && offset_max) { 1618 q = q->next; 1619 LWIP_ASSERT("next pbuf was null", q); 1620 options = (u8_t*)q->payload; 1621 } else { 1622 /* We've run out of bytes, probably no end marker. Don't proceed. */ 1623 break; 1624 } 1625 } 1626 } 1627 /* is this an overloaded message? */ 1628 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_OVERLOAD)) { 1629 u32_t overload = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_OVERLOAD); 1630 dhcp_clear_option(dhcp, DHCP_OPTION_IDX_OVERLOAD); 1631 if (overload == DHCP_OVERLOAD_FILE) { 1632 parse_file_as_options = 1; 1633 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded file field\n")); 1634 } else if (overload == DHCP_OVERLOAD_SNAME) { 1635 parse_sname_as_options = 1; 1636 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname field\n")); 1637 } else if (overload == DHCP_OVERLOAD_SNAME_FILE) { 1638 parse_sname_as_options = 1; 1639 parse_file_as_options = 1; 1640 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname and file field\n")); 1641 } else { 1642 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("invalid overload option: %d\n", (int)overload)); 1643 } 1644 #if LWIP_DHCP_BOOTP_FILE 1645 if (!parse_file_as_options) { 1646 /* only do this for ACK messages */ 1647 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) && 1648 (dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK)) 1649 /* copy bootp file name, don't care for sname (server hostname) */ 1650 if (pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS) != (DHCP_FILE_LEN-1)) { 1651 return ERR_BUF; 1652 } 1653 /* make sure the string is really NULL-terminated */ 1654 dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0; 1655 } 1656 #endif /* LWIP_DHCP_BOOTP_FILE */ 1657 } 1658 if (parse_file_as_options) { 1659 /* if both are overloaded, parse file first and then sname (RFC 2131 ch. 4.1) */ 1660 parse_file_as_options = 0; 1661 options_idx = DHCP_FILE_OFS; 1662 options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN; 1663 goto again; 1664 } else if (parse_sname_as_options) { 1665 parse_sname_as_options = 0; 1666 options_idx = DHCP_SNAME_OFS; 1667 options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN; 1668 goto again; 1669 } 1670 return ERR_OK; 1671 } 1672 1673 /** 1674 * If an incoming DHCP message is in response to us, then trigger the state machine 1675 */ 1676 static void 1677 dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port) 1678 { 1679 struct netif *netif = ip_current_input_netif(); 1680 struct dhcp *dhcp = netif_dhcp_data(netif); 1681 struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload; 1682 u8_t msg_type; 1683 u8_t i; 1684 1685 LWIP_UNUSED_ARG(arg); 1686 1687 /* Caught DHCP message from netif that does not have DHCP enabled? -> not interested */ 1688 if ((dhcp == NULL) || (dhcp->pcb_allocated == 0)) { 1689 goto free_pbuf_and_return; 1690 } 1691 1692 LWIP_ASSERT("invalid server address type", IP_IS_V4(addr)); 1693 1694 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, 1695 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)); 1696 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len)); 1697 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len)); 1698 /* prevent warnings about unused arguments */ 1699 LWIP_UNUSED_ARG(pcb); 1700 LWIP_UNUSED_ARG(addr); 1701 LWIP_UNUSED_ARG(port); 1702 1703 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL); 1704 1705 if (p->len < DHCP_MIN_REPLY_LEN) { 1706 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP reply message or pbuf too short\n")); 1707 goto free_pbuf_and_return; 1708 } 1709 1710 if (reply_msg->op != DHCP_BOOTREPLY) { 1711 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)); 1712 goto free_pbuf_and_return; 1713 } 1714 /* iterate through hardware address and match against DHCP message */ 1715 for (i = 0; i < netif->hwaddr_len && i < NETIF_MAX_HWADDR_LEN && i < DHCP_CHADDR_LEN; i++) { 1716 if (netif->hwaddr[i] != reply_msg->chaddr[i]) { 1717 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, 1718 ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n", 1719 (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i])); 1720 goto free_pbuf_and_return; 1721 } 1722 } 1723 /* match transaction ID against what we expected */ 1724 if (lwip_ntohl(reply_msg->xid) != dhcp->xid) { 1725 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, 1726 ("transaction id mismatch reply_msg->xid(%"X32_F")!=dhcp->xid(%"X32_F")\n",lwip_ntohl(reply_msg->xid),dhcp->xid)); 1727 goto free_pbuf_and_return; 1728 } 1729 /* option fields could be unfold? */ 1730 if (dhcp_parse_reply(dhcp, p) != ERR_OK) { 1731 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 1732 ("problem unfolding DHCP message - too short on memory?\n")); 1733 goto free_pbuf_and_return; 1734 } 1735 1736 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n")); 1737 /* obtain pointer to DHCP message type */ 1738 if (!dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE)) { 1739 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP_OPTION_MESSAGE_TYPE option not found\n")); 1740 goto free_pbuf_and_return; 1741 } 1742 1743 /* read DHCP message type */ 1744 msg_type = (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE); 1745 /* message type is DHCP ACK? */ 1746 if (msg_type == DHCP_ACK) { 1747 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_ACK received\n")); 1748 /* in requesting state? */ 1749 if (dhcp->state == DHCP_STATE_REQUESTING) { 1750 dhcp_handle_ack(netif); 1751 #if DHCP_DOES_ARP_CHECK 1752 if ((netif->flags & NETIF_FLAG_ETHARP) != 0) { 1753 /* check if the acknowledged lease address is already in use */ 1754 dhcp_check(netif); 1755 } else { 1756 /* bind interface to the acknowledged lease address */ 1757 dhcp_bind(netif); 1758 } 1759 #else 1760 /* bind interface to the acknowledged lease address */ 1761 dhcp_bind(netif); 1762 #endif 1763 } 1764 /* already bound to the given lease address? */ 1765 else if ((dhcp->state == DHCP_STATE_REBOOTING) || (dhcp->state == DHCP_STATE_REBINDING) || 1766 (dhcp->state == DHCP_STATE_RENEWING)) { 1767 dhcp_handle_ack(netif); 1768 dhcp_bind(netif); 1769 } 1770 } 1771 /* received a DHCP_NAK in appropriate state? */ 1772 else if ((msg_type == DHCP_NAK) && 1773 ((dhcp->state == DHCP_STATE_REBOOTING) || (dhcp->state == DHCP_STATE_REQUESTING) || 1774 (dhcp->state == DHCP_STATE_REBINDING) || (dhcp->state == DHCP_STATE_RENEWING ))) { 1775 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_NAK received\n")); 1776 dhcp_handle_nak(netif); 1777 } 1778 /* received a DHCP_OFFER in DHCP_STATE_SELECTING state? */ 1779 else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_STATE_SELECTING)) { 1780 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_OFFER received in DHCP_STATE_SELECTING state\n")); 1781 dhcp->request_timeout = 0; 1782 /* remember offered lease */ 1783 dhcp_handle_offer(netif); 1784 } 1785 1786 free_pbuf_and_return: 1787 if (dhcp != NULL) { 1788 dhcp->msg_in = NULL; 1789 } 1790 pbuf_free(p); 1791 } 1792 1793 /** 1794 * Create a DHCP request, fill in common headers 1795 * 1796 * @param netif the netif under DHCP control 1797 * @param dhcp dhcp control struct 1798 * @param message_type message type of the request 1799 */ 1800 static err_t 1801 dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type) 1802 { 1803 u16_t i; 1804 #ifndef DHCP_GLOBAL_XID 1805 /** default global transaction identifier starting value (easy to match 1806 * with a packet analyser). We simply increment for each new request. 1807 * Predefine DHCP_GLOBAL_XID to a better value or a function call to generate one 1808 * at runtime, any supporting function prototypes can be defined in DHCP_GLOBAL_XID_HEADER */ 1809 #if DHCP_CREATE_RAND_XID && defined(LWIP_RAND) 1810 static u32_t xid; 1811 #else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ 1812 static u32_t xid = 0xABCD0000; 1813 #endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ 1814 #else 1815 if (!xid_initialised) { 1816 xid = DHCP_GLOBAL_XID; 1817 xid_initialised = !xid_initialised; 1818 } 1819 #endif 1820 LWIP_ERROR("dhcp_create_msg: netif != NULL", (netif != NULL), return ERR_ARG;); 1821 LWIP_ERROR("dhcp_create_msg: dhcp != NULL", (dhcp != NULL), return ERR_VAL;); 1822 LWIP_ASSERT("dhcp_create_msg: dhcp->p_out == NULL", dhcp->p_out == NULL); 1823 LWIP_ASSERT("dhcp_create_msg: dhcp->msg_out == NULL", dhcp->msg_out == NULL); 1824 dhcp->p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM); 1825 if (dhcp->p_out == NULL) { 1826 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 1827 ("dhcp_create_msg(): could not allocate pbuf\n")); 1828 return ERR_MEM; 1829 } 1830 LWIP_ASSERT("dhcp_create_msg: check that first pbuf can hold struct dhcp_msg", 1831 (dhcp->p_out->len >= sizeof(struct dhcp_msg))); 1832 1833 /* DHCP_REQUEST should reuse 'xid' from DHCPOFFER */ 1834 if (message_type != DHCP_REQUEST) { 1835 /* reuse transaction identifier in retransmissions */ 1836 if (dhcp->tries == 0) { 1837 #if DHCP_CREATE_RAND_XID && defined(LWIP_RAND) 1838 xid = LWIP_RAND(); 1839 #else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ 1840 xid++; 1841 #endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ 1842 } 1843 dhcp->xid = xid; 1844 } 1845 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, 1846 ("transaction id xid(%"X32_F")\n", xid)); 1847 1848 dhcp->msg_out = (struct dhcp_msg *)dhcp->p_out->payload; 1849 1850 dhcp->msg_out->op = DHCP_BOOTREQUEST; 1851 /* @todo: make link layer independent */ 1852 dhcp->msg_out->htype = DHCP_HTYPE_ETH; 1853 dhcp->msg_out->hlen = netif->hwaddr_len; 1854 dhcp->msg_out->hops = 0; 1855 dhcp->msg_out->xid = lwip_htonl(dhcp->xid); 1856 dhcp->msg_out->secs = 0; 1857 /* we don't need the broadcast flag since we can receive unicast traffic 1858 before being fully configured! */ 1859 dhcp->msg_out->flags = 0; 1860 ip4_addr_set_zero(&dhcp->msg_out->ciaddr); 1861 /* set ciaddr to netif->ip_addr based on message_type and state */ 1862 if ((message_type == DHCP_INFORM) || (message_type == DHCP_DECLINE) || (message_type == DHCP_RELEASE) || 1863 ((message_type == DHCP_REQUEST) && /* DHCP_STATE_BOUND not used for sending! */ 1864 ((dhcp->state== DHCP_STATE_RENEWING) || dhcp->state== DHCP_STATE_REBINDING))) { 1865 ip4_addr_copy(dhcp->msg_out->ciaddr, *netif_ip4_addr(netif)); 1866 } 1867 ip4_addr_set_zero(&dhcp->msg_out->yiaddr); 1868 ip4_addr_set_zero(&dhcp->msg_out->siaddr); 1869 ip4_addr_set_zero(&dhcp->msg_out->giaddr); 1870 for (i = 0; i < DHCP_CHADDR_LEN; i++) { 1871 /* copy netif hardware address, pad with zeroes */ 1872 dhcp->msg_out->chaddr[i] = (i < netif->hwaddr_len && i < NETIF_MAX_HWADDR_LEN) ? netif->hwaddr[i] : 0/* pad byte*/; 1873 } 1874 for (i = 0; i < DHCP_SNAME_LEN; i++) { 1875 dhcp->msg_out->sname[i] = 0; 1876 } 1877 for (i = 0; i < DHCP_FILE_LEN; i++) { 1878 dhcp->msg_out->file[i] = 0; 1879 } 1880 dhcp->msg_out->cookie = PP_HTONL(DHCP_MAGIC_COOKIE); 1881 dhcp->options_out_len = 0; 1882 /* fill options field with an incrementing array (for debugging purposes) */ 1883 for (i = 0; i < DHCP_OPTIONS_LEN; i++) { 1884 dhcp->msg_out->options[i] = (u8_t)i; /* for debugging only, no matter if truncated */ 1885 } 1886 /* Add option MESSAGE_TYPE */ 1887 dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); 1888 dhcp_option_byte(dhcp, message_type); 1889 return ERR_OK; 1890 } 1891 1892 /** 1893 * Free previously allocated memory used to send a DHCP request. 1894 * 1895 * @param dhcp the dhcp struct to free the request from 1896 */ 1897 static void 1898 dhcp_delete_msg(struct dhcp *dhcp) 1899 { 1900 LWIP_ERROR("dhcp_delete_msg: dhcp != NULL", (dhcp != NULL), return;); 1901 LWIP_ASSERT("dhcp_delete_msg: dhcp->p_out != NULL", dhcp->p_out != NULL); 1902 LWIP_ASSERT("dhcp_delete_msg: dhcp->msg_out != NULL", dhcp->msg_out != NULL); 1903 if (dhcp->p_out != NULL) { 1904 pbuf_free(dhcp->p_out); 1905 } 1906 dhcp->p_out = NULL; 1907 dhcp->msg_out = NULL; 1908 } 1909 1910 /** 1911 * Add a DHCP message trailer 1912 * 1913 * Adds the END option to the DHCP message, and if 1914 * necessary, up to three padding bytes. 1915 * 1916 * @param dhcp DHCP state structure 1917 */ 1918 static void 1919 dhcp_option_trailer(struct dhcp *dhcp) 1920 { 1921 LWIP_ERROR("dhcp_option_trailer: dhcp != NULL", (dhcp != NULL), return;); 1922 LWIP_ASSERT("dhcp_option_trailer: dhcp->msg_out != NULL\n", dhcp->msg_out != NULL); 1923 LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN); 1924 dhcp->msg_out->options[dhcp->options_out_len++] = DHCP_OPTION_END; 1925 /* packet is too small, or not 4 byte aligned? */ 1926 while (((dhcp->options_out_len < DHCP_MIN_OPTIONS_LEN) || (dhcp->options_out_len & 3)) && 1927 (dhcp->options_out_len < DHCP_OPTIONS_LEN)) { 1928 /* add a fill/padding byte */ 1929 dhcp->msg_out->options[dhcp->options_out_len++] = 0; 1930 } 1931 } 1932 1933 /** check if DHCP supplied netif->ip_addr 1934 * 1935 * @param netif the netif to check 1936 * @return 1 if DHCP supplied netif->ip_addr (states BOUND or RENEWING), 1937 * 0 otherwise 1938 */ 1939 u8_t 1940 dhcp_supplied_address(const struct netif *netif) 1941 { 1942 if ((netif != NULL) && (netif_dhcp_data(netif) != NULL)) { 1943 struct dhcp* dhcp = netif_dhcp_data(netif); 1944 return (dhcp->state == DHCP_STATE_BOUND) || (dhcp->state == DHCP_STATE_RENEWING); 1945 } 1946 return 0; 1947 } 1948 1949 #endif /* LWIP_IPV4 && LWIP_DHCP */ 1950