Mihail Stoyanov
/
HTTPServer
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dhcp.c
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00001 /** 00002 * @file 00003 * Dynamic Host Configuration Protocol client 00004 * 00005 */ 00006 00007 /* 00008 * 00009 * Copyright (c) 2001-2004 Leon Woestenberg <leon.woestenberg@gmx.net> 00010 * Copyright (c) 2001-2004 Axon Digital Design B.V., The Netherlands. 00011 * All rights reserved. 00012 * 00013 * Redistribution and use in source and binary forms, with or without modification, 00014 * are permitted provided that the following conditions are met: 00015 * 00016 * 1. Redistributions of source code must retain the above copyright notice, 00017 * this list of conditions and the following disclaimer. 00018 * 2. Redistributions in binary form must reproduce the above copyright notice, 00019 * this list of conditions and the following disclaimer in the documentation 00020 * and/or other materials provided with the distribution. 00021 * 3. The name of the author may not be used to endorse or promote products 00022 * derived from this software without specific prior written permission. 00023 * 00024 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 00025 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00026 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 00027 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00028 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 00029 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00030 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00031 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 00032 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 00033 * OF SUCH DAMAGE. 00034 * 00035 * This file is a contribution to the lwIP TCP/IP stack. 00036 * The Swedish Institute of Computer Science and Adam Dunkels 00037 * are specifically granted permission to redistribute this 00038 * source code. 00039 * 00040 * Author: Leon Woestenberg <leon.woestenberg@gmx.net> 00041 * 00042 * This is a DHCP client for the lwIP TCP/IP stack. It aims to conform 00043 * with RFC 2131 and RFC 2132. 00044 * 00045 * TODO: 00046 * - Proper parsing of DHCP messages exploiting file/sname field overloading. 00047 * - Add JavaDoc style documentation (API, internals). 00048 * - Support for interfaces other than Ethernet (SLIP, PPP, ...) 00049 * 00050 * Please coordinate changes and requests with Leon Woestenberg 00051 * <leon.woestenberg@gmx.net> 00052 * 00053 * Integration with your code: 00054 * 00055 * In lwip/dhcp.h 00056 * #define DHCP_COARSE_TIMER_SECS (recommended 60 which is a minute) 00057 * #define DHCP_FINE_TIMER_MSECS (recommended 500 which equals TCP coarse timer) 00058 * 00059 * Then have your application call dhcp_coarse_tmr() and 00060 * dhcp_fine_tmr() on the defined intervals. 00061 * 00062 * dhcp_start(struct netif *netif); 00063 * starts a DHCP client instance which configures the interface by 00064 * obtaining an IP address lease and maintaining it. 00065 * 00066 * Use dhcp_release(netif) to end the lease and use dhcp_stop(netif) 00067 * to remove the DHCP client. 00068 * 00069 */ 00070 00071 #include "lwip/opt.h" 00072 00073 #if LWIP_DHCP /* don't build if not configured for use in lwipopts.h */ 00074 00075 #include "lwip/stats.h" 00076 #include "lwip/mem.h" 00077 #include "lwip/udp.h" 00078 #include "lwip/ip_addr.h" 00079 #include "lwip/netif.h" 00080 #include "lwip/inet.h" 00081 #include "lwip/sys.h" 00082 #include "lwip/dhcp.h " 00083 #include "lwip/autoip.h" 00084 #include "lwip/dns.h" 00085 #include "netif/etharp.h" 00086 00087 #include <string.h> 00088 00089 /** Default for DHCP_GLOBAL_XID is 0xABCD0000 00090 * This can be changed by defining DHCP_GLOBAL_XID and DHCP_GLOBAL_XID_HEADER, e.g. 00091 * #define DHCP_GLOBAL_XID_HEADER "stdlib.h" 00092 * #define DHCP_GLOBAL_XID rand() 00093 */ 00094 #ifdef DHCP_GLOBAL_XID_HEADER 00095 #include DHCP_GLOBAL_XID_HEADER /* include optional starting XID generation prototypes */ 00096 #endif 00097 00098 /** DHCP_OPTION_MAX_MSG_SIZE is set to the MTU 00099 * MTU is checked to be big enough in dhcp_start */ 00100 #define DHCP_MAX_MSG_LEN(netif) (netif->mtu) 00101 #define DHCP_MAX_MSG_LEN_MIN_REQUIRED 576 00102 00103 /* DHCP client state machine functions */ 00104 static void dhcp_handle_ack(struct netif *netif); 00105 static void dhcp_handle_nak(struct netif *netif); 00106 static void dhcp_handle_offer(struct netif *netif); 00107 00108 static err_t dhcp_discover(struct netif *netif); 00109 static err_t dhcp_select(struct netif *netif); 00110 static void dhcp_check(struct netif *netif); 00111 static void dhcp_bind(struct netif *netif); 00112 #if DHCP_DOES_ARP_CHECK 00113 static err_t dhcp_decline(struct netif *netif); 00114 #endif /* DHCP_DOES_ARP_CHECK */ 00115 static err_t dhcp_rebind(struct netif *netif); 00116 static void dhcp_set_state(struct dhcp *dhcp, u8_t new_state); 00117 00118 /* receive, unfold, parse and free incoming messages */ 00119 static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port); 00120 static err_t dhcp_unfold_reply(struct dhcp *dhcp); 00121 static u8_t *dhcp_get_option_ptr(struct dhcp *dhcp, u8_t option_type); 00122 static u8_t dhcp_get_option_byte(u8_t *ptr); 00123 #if 0 00124 static u16_t dhcp_get_option_short(u8_t *ptr); 00125 #endif 00126 static u32_t dhcp_get_option_long(u8_t *ptr); 00127 static void dhcp_free_reply(struct dhcp *dhcp); 00128 00129 /* set the DHCP timers */ 00130 static void dhcp_timeout(struct netif *netif); 00131 static void dhcp_t1_timeout(struct netif *netif); 00132 static void dhcp_t2_timeout(struct netif *netif); 00133 00134 /* build outgoing messages */ 00135 /* create a DHCP request, fill in common headers */ 00136 static err_t dhcp_create_request(struct netif *netif); 00137 /* free a DHCP request */ 00138 static void dhcp_delete_request(struct netif *netif); 00139 /* add a DHCP option (type, then length in bytes) */ 00140 static void dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len); 00141 /* add option values */ 00142 static void dhcp_option_byte(struct dhcp *dhcp, u8_t value); 00143 static void dhcp_option_short(struct dhcp *dhcp, u16_t value); 00144 static void dhcp_option_long(struct dhcp *dhcp, u32_t value); 00145 /* always add the DHCP options trailer to end and pad */ 00146 static void dhcp_option_trailer(struct dhcp *dhcp); 00147 00148 /** 00149 * Back-off the DHCP client (because of a received NAK response). 00150 * 00151 * Back-off the DHCP client because of a received NAK. Receiving a 00152 * NAK means the client asked for something non-sensible, for 00153 * example when it tries to renew a lease obtained on another network. 00154 * 00155 * We clear any existing set IP address and restart DHCP negotiation 00156 * afresh (as per RFC2131 3.2.3). 00157 * 00158 * @param netif the netif under DHCP control 00159 */ 00160 static void 00161 dhcp_handle_nak(struct netif *netif) 00162 { 00163 struct dhcp *dhcp = netif->dhcp; 00164 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 3, ("dhcp_handle_nak(netif=%p) %c%c%"U16_F"\n", 00165 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); 00166 /* Set the interface down since the address must no longer be used, as per RFC2131 */ 00167 netif_set_down(netif); 00168 /* remove IP address from interface */ 00169 netif_set_ipaddr(netif, IP_ADDR_ANY); 00170 netif_set_gw(netif, IP_ADDR_ANY); 00171 netif_set_netmask(netif, IP_ADDR_ANY); 00172 /* Change to a defined state */ 00173 dhcp_set_state(dhcp, DHCP_BACKING_OFF); 00174 /* We can immediately restart discovery */ 00175 dhcp_discover(netif); 00176 } 00177 00178 /** 00179 * Checks if the offered IP address is already in use. 00180 * 00181 * It does so by sending an ARP request for the offered address and 00182 * entering CHECKING state. If no ARP reply is received within a small 00183 * interval, the address is assumed to be free for use by us. 00184 * 00185 * @param netif the netif under DHCP control 00186 */ 00187 static void 00188 dhcp_check(struct netif *netif) 00189 { 00190 struct dhcp *dhcp = netif->dhcp; 00191 err_t result; 00192 u16_t msecs; 00193 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 3, ("dhcp_check(netif=%p) %c%c\n", (void *)netif, (s16_t)netif->name[0], 00194 (s16_t)netif->name[1])); 00195 /* create an ARP query for the offered IP address, expecting that no host 00196 responds, as the IP address should not be in use. */ 00197 result = etharp_query(netif, &dhcp->offered_ip_addr, NULL); 00198 if (result != ERR_OK) { 00199 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("dhcp_check: could not perform ARP query\n")); 00200 } 00201 dhcp->tries++; 00202 msecs = 500; 00203 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 00204 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_check(): set request timeout %"U16_F" msecs\n", msecs)); 00205 dhcp_set_state(dhcp, DHCP_CHECKING); 00206 } 00207 00208 /** 00209 * Remember the configuration offered by a DHCP server. 00210 * 00211 * @param netif the netif under DHCP control 00212 */ 00213 static void 00214 dhcp_handle_offer(struct netif *netif) 00215 { 00216 struct dhcp *dhcp = netif->dhcp; 00217 /* obtain the server address */ 00218 u8_t *option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_SERVER_ID); 00219 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 3, ("dhcp_handle_offer(netif=%p) %c%c%"U16_F"\n", 00220 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); 00221 if (option_ptr != NULL) { 00222 dhcp->server_ip_addr.addr = htonl(dhcp_get_option_long(&option_ptr[2])); 00223 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): server 0x%08"X32_F"\n", dhcp->server_ip_addr.addr)); 00224 /* remember offered address */ 00225 ip_addr_set(&dhcp->offered_ip_addr, (struct ip_addr *)&dhcp->msg_in->yiaddr); 00226 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): offer for 0x%08"X32_F"\n", dhcp->offered_ip_addr.addr)); 00227 00228 dhcp_select(netif); 00229 } 00230 } 00231 00232 /** 00233 * Select a DHCP server offer out of all offers. 00234 * 00235 * Simply select the first offer received. 00236 * 00237 * @param netif the netif under DHCP control 00238 * @return lwIP specific error (see error.h) 00239 */ 00240 static err_t 00241 dhcp_select(struct netif *netif) 00242 { 00243 struct dhcp *dhcp = netif->dhcp; 00244 err_t result; 00245 u16_t msecs; 00246 #if LWIP_NETIF_HOSTNAME 00247 const char *p; 00248 #endif /* LWIP_NETIF_HOSTNAME */ 00249 00250 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 3, ("dhcp_select(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); 00251 00252 /* create and initialize the DHCP message header */ 00253 result = dhcp_create_request(netif); 00254 if (result == ERR_OK) { 00255 dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); 00256 dhcp_option_byte(dhcp, DHCP_REQUEST); 00257 00258 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 00259 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 00260 00261 /* MUST request the offered IP address */ 00262 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 00263 dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); 00264 00265 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); 00266 dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr)); 00267 00268 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/); 00269 dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK); 00270 dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER); 00271 dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST); 00272 dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER); 00273 00274 #if LWIP_NETIF_HOSTNAME 00275 p = (const char*)netif->hostname; 00276 if (p != NULL) { 00277 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, strlen(p)); 00278 while (*p) { 00279 dhcp_option_byte(dhcp, *p++); 00280 } 00281 } 00282 #endif /* LWIP_NETIF_HOSTNAME */ 00283 00284 dhcp_option_trailer(dhcp); 00285 /* shrink the pbuf to the actual content length */ 00286 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 00287 00288 /* TODO: we really should bind to a specific local interface here 00289 but we cannot specify an unconfigured netif as it is addressless */ 00290 /* send broadcast to any DHCP server */ 00291 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 00292 /* reconnect to any (or to server here?!) */ 00293 udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); 00294 dhcp_delete_request(netif); 00295 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_select: REQUESTING\n")); 00296 dhcp_set_state(dhcp, DHCP_REQUESTING); 00297 } else { 00298 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("dhcp_select: could not allocate DHCP request\n")); 00299 } 00300 dhcp->tries++; 00301 msecs = dhcp->tries < 4 ? dhcp->tries * 1000 : 4 * 1000; 00302 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 00303 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_select(): set request timeout %"U16_F" msecs\n", msecs)); 00304 return result; 00305 } 00306 00307 /** 00308 * The DHCP timer that checks for lease renewal/rebind timeouts. 00309 * 00310 */ 00311 void 00312 dhcp_coarse_tmr() 00313 { 00314 struct netif *netif = netif_list; 00315 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n")); 00316 /* iterate through all network interfaces */ 00317 while (netif != NULL) { 00318 /* only act on DHCP configured interfaces */ 00319 if (netif->dhcp != NULL) { 00320 /* timer is active (non zero), and triggers (zeroes) now? */ 00321 if (netif->dhcp->t2_timeout-- == 1) { 00322 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t2 timeout\n")); 00323 /* this clients' rebind timeout triggered */ 00324 dhcp_t2_timeout(netif); 00325 /* timer is active (non zero), and triggers (zeroes) now */ 00326 } else if (netif->dhcp->t1_timeout-- == 1) { 00327 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t1 timeout\n")); 00328 /* this clients' renewal timeout triggered */ 00329 dhcp_t1_timeout(netif); 00330 } 00331 } 00332 /* proceed to next netif */ 00333 netif = netif->next; 00334 } 00335 } 00336 00337 /** 00338 * DHCP transaction timeout handling 00339 * 00340 * A DHCP server is expected to respond within a short period of time. 00341 * This timer checks whether an outstanding DHCP request is timed out. 00342 * 00343 */ 00344 void 00345 dhcp_fine_tmr() 00346 { 00347 struct netif *netif = netif_list; 00348 /* loop through netif's */ 00349 while (netif != NULL) { 00350 /* only act on DHCP configured interfaces */ 00351 if (netif->dhcp != NULL) { 00352 /* timer is active (non zero), and is about to trigger now */ 00353 if (netif->dhcp->request_timeout > 1) { 00354 netif->dhcp->request_timeout--; 00355 } 00356 else if (netif->dhcp->request_timeout == 1) { 00357 netif->dhcp->request_timeout--; 00358 /* { netif->dhcp->request_timeout == 0 } */ 00359 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_fine_tmr(): request timeout\n")); 00360 /* this clients' request timeout triggered */ 00361 dhcp_timeout(netif); 00362 } 00363 } 00364 /* proceed to next network interface */ 00365 netif = netif->next; 00366 } 00367 } 00368 00369 /** 00370 * A DHCP negotiation transaction, or ARP request, has timed out. 00371 * 00372 * The timer that was started with the DHCP or ARP request has 00373 * timed out, indicating no response was received in time. 00374 * 00375 * @param netif the netif under DHCP control 00376 */ 00377 static void 00378 dhcp_timeout(struct netif *netif) 00379 { 00380 struct dhcp *dhcp = netif->dhcp; 00381 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 3, ("dhcp_timeout()\n")); 00382 /* back-off period has passed, or server selection timed out */ 00383 if ((dhcp->state == DHCP_BACKING_OFF) || (dhcp->state == DHCP_SELECTING)) { 00384 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout(): restarting discovery\n")); 00385 dhcp_discover(netif); 00386 /* receiving the requested lease timed out */ 00387 } else if (dhcp->state == DHCP_REQUESTING) { 00388 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, DHCP request timed out\n")); 00389 if (dhcp->tries <= 5) { 00390 dhcp_select(netif); 00391 } else { 00392 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, releasing, restarting\n")); 00393 dhcp_release(netif); 00394 dhcp_discover(netif); 00395 } 00396 /* received no ARP reply for the offered address (which is good) */ 00397 } else if (dhcp->state == DHCP_CHECKING) { 00398 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): CHECKING, ARP request timed out\n")); 00399 if (dhcp->tries <= 1) { 00400 dhcp_check(netif); 00401 /* no ARP replies on the offered address, 00402 looks like the IP address is indeed free */ 00403 } else { 00404 /* bind the interface to the offered address */ 00405 dhcp_bind(netif); 00406 } 00407 } 00408 /* did not get response to renew request? */ 00409 else if (dhcp->state == DHCP_RENEWING) { 00410 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): RENEWING, DHCP request timed out\n")); 00411 /* just retry renewal */ 00412 /* note that the rebind timer will eventually time-out if renew does not work */ 00413 dhcp_renew(netif); 00414 /* did not get response to rebind request? */ 00415 } else if (dhcp->state == DHCP_REBINDING) { 00416 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REBINDING, DHCP request timed out\n")); 00417 if (dhcp->tries <= 8) { 00418 dhcp_rebind(netif); 00419 } else { 00420 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): RELEASING, DISCOVERING\n")); 00421 dhcp_release(netif); 00422 dhcp_discover(netif); 00423 } 00424 } 00425 } 00426 00427 /** 00428 * The renewal period has timed out. 00429 * 00430 * @param netif the netif under DHCP control 00431 */ 00432 static void 00433 dhcp_t1_timeout(struct netif *netif) 00434 { 00435 struct dhcp *dhcp = netif->dhcp; 00436 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_t1_timeout()\n")); 00437 if ((dhcp->state == DHCP_REQUESTING) || (dhcp->state == DHCP_BOUND) || (dhcp->state == DHCP_RENEWING)) { 00438 /* just retry to renew - note that the rebind timer (t2) will 00439 * eventually time-out if renew tries fail. */ 00440 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t1_timeout(): must renew\n")); 00441 dhcp_renew(netif); 00442 } 00443 } 00444 00445 /** 00446 * The rebind period has timed out. 00447 * 00448 * @param netif the netif under DHCP control 00449 */ 00450 static void 00451 dhcp_t2_timeout(struct netif *netif) 00452 { 00453 struct dhcp *dhcp = netif->dhcp; 00454 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t2_timeout()\n")); 00455 if ((dhcp->state == DHCP_REQUESTING) || (dhcp->state == DHCP_BOUND) || (dhcp->state == DHCP_RENEWING)) { 00456 /* just retry to rebind */ 00457 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t2_timeout(): must rebind\n")); 00458 dhcp_rebind(netif); 00459 } 00460 } 00461 00462 /** 00463 * Handle a DHCP ACK packet 00464 * 00465 * @param netif the netif under DHCP control 00466 */ 00467 static void 00468 dhcp_handle_ack(struct netif *netif) 00469 { 00470 struct dhcp *dhcp = netif->dhcp; 00471 u8_t *option_ptr; 00472 /* clear options we might not get from the ACK */ 00473 dhcp->offered_sn_mask.addr = 0; 00474 dhcp->offered_gw_addr.addr = 0; 00475 dhcp->offered_bc_addr.addr = 0; 00476 00477 /* lease time given? */ 00478 option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_LEASE_TIME); 00479 if (option_ptr != NULL) { 00480 /* remember offered lease time */ 00481 dhcp->offered_t0_lease = dhcp_get_option_long(option_ptr + 2); 00482 } 00483 /* renewal period given? */ 00484 option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_T1); 00485 if (option_ptr != NULL) { 00486 /* remember given renewal period */ 00487 dhcp->offered_t1_renew = dhcp_get_option_long(option_ptr + 2); 00488 } else { 00489 /* calculate safe periods for renewal */ 00490 dhcp->offered_t1_renew = dhcp->offered_t0_lease / 2; 00491 } 00492 00493 /* renewal period given? */ 00494 option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_T2); 00495 if (option_ptr != NULL) { 00496 /* remember given rebind period */ 00497 dhcp->offered_t2_rebind = dhcp_get_option_long(option_ptr + 2); 00498 } else { 00499 /* calculate safe periods for rebinding */ 00500 dhcp->offered_t2_rebind = dhcp->offered_t0_lease; 00501 } 00502 00503 /* (y)our internet address */ 00504 ip_addr_set(&dhcp->offered_ip_addr, &dhcp->msg_in->yiaddr); 00505 00506 /** 00507 * Patch #1308 00508 * TODO: we must check if the file field is not overloaded by DHCP options! 00509 */ 00510 #if 0 00511 /* boot server address */ 00512 ip_addr_set(&dhcp->offered_si_addr, &dhcp->msg_in->siaddr); 00513 /* boot file name */ 00514 if (dhcp->msg_in->file[0]) { 00515 dhcp->boot_file_name = mem_malloc(strlen(dhcp->msg_in->file) + 1); 00516 strcpy(dhcp->boot_file_name, dhcp->msg_in->file); 00517 } 00518 #endif 00519 00520 /* subnet mask */ 00521 option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_SUBNET_MASK); 00522 /* subnet mask given? */ 00523 if (option_ptr != NULL) { 00524 dhcp->offered_sn_mask.addr = htonl(dhcp_get_option_long(&option_ptr[2])); 00525 } 00526 00527 /* gateway router */ 00528 option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_ROUTER); 00529 if (option_ptr != NULL) { 00530 dhcp->offered_gw_addr.addr = htonl(dhcp_get_option_long(&option_ptr[2])); 00531 } 00532 00533 /* broadcast address */ 00534 option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_BROADCAST); 00535 if (option_ptr != NULL) { 00536 dhcp->offered_bc_addr.addr = htonl(dhcp_get_option_long(&option_ptr[2])); 00537 } 00538 00539 /* DNS servers */ 00540 option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_DNS_SERVER); 00541 if (option_ptr != NULL) { 00542 u8_t n; 00543 dhcp->dns_count = dhcp_get_option_byte(&option_ptr[1]) / (u32_t)sizeof(struct ip_addr); 00544 /* limit to at most DHCP_MAX_DNS DNS servers */ 00545 if (dhcp->dns_count > DHCP_MAX_DNS) 00546 dhcp->dns_count = DHCP_MAX_DNS; 00547 for (n = 0; n < dhcp->dns_count; n++) { 00548 dhcp->offered_dns_addr[n].addr = htonl(dhcp_get_option_long(&option_ptr[2 + n * 4])); 00549 #if LWIP_DNS 00550 dns_setserver( n, (struct ip_addr *)(&(dhcp->offered_dns_addr[n].addr))); 00551 #endif /* LWIP_DNS */ 00552 } 00553 #if LWIP_DNS 00554 dns_setserver( n, (struct ip_addr *)(&ip_addr_any)); 00555 #endif /* LWIP_DNS */ 00556 } 00557 } 00558 00559 /** 00560 * Start DHCP negotiation for a network interface. 00561 * 00562 * If no DHCP client instance was attached to this interface, 00563 * a new client is created first. If a DHCP client instance 00564 * was already present, it restarts negotiation. 00565 * 00566 * @param netif The lwIP network interface 00567 * @return lwIP error code 00568 * - ERR_OK - No error 00569 * - ERR_MEM - Out of memory 00570 */ 00571 err_t 00572 dhcp_start(struct netif *netif) 00573 { 00574 struct dhcp *dhcp; 00575 err_t result = ERR_OK; 00576 00577 LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;); 00578 dhcp = netif->dhcp; 00579 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)); 00580 /* Remove the flag that says this netif is handled by DHCP, 00581 it is set when we succeeded starting. */ 00582 netif->flags &= ~NETIF_FLAG_DHCP; 00583 00584 /* check MTU of the netif */ 00585 if (netif->mtu < DHCP_MAX_MSG_LEN_MIN_REQUIRED) { 00586 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): Cannot use this netif with DHCP: MTU is too small\n")); 00587 return ERR_MEM; 00588 } 00589 00590 /* no DHCP client attached yet? */ 00591 if (dhcp == NULL) { 00592 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting new DHCP client\n")); 00593 dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp)); // static_cast<struct dhcp *>(x) 00594 if (dhcp == NULL) { 00595 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n")); 00596 return ERR_MEM; 00597 } 00598 /* store this dhcp client in the netif */ 00599 netif->dhcp = dhcp; 00600 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): allocated dhcp")); 00601 /* already has DHCP client attached */ 00602 } else { 00603 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 3, ("dhcp_start(): restarting DHCP configuration\n")); 00604 if (dhcp->pcb != NULL) { 00605 udp_remove(dhcp->pcb); 00606 } 00607 if (dhcp->p != NULL) { 00608 pbuf_free(dhcp->p); 00609 } 00610 } 00611 00612 /* clear data structure */ 00613 memset(dhcp, 0, sizeof(struct dhcp)); 00614 /* allocate UDP PCB */ 00615 dhcp->pcb = udp_new(); 00616 if (dhcp->pcb == NULL) { 00617 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not obtain pcb\n")); 00618 mem_free((void *)dhcp); 00619 netif->dhcp = dhcp = NULL; 00620 return ERR_MEM; 00621 } 00622 /* set up local and remote port for the pcb */ 00623 udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); 00624 udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); 00625 /* set up the recv callback and argument */ 00626 udp_recv(dhcp->pcb, dhcp_recv, netif); 00627 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n")); 00628 /* (re)start the DHCP negotiation */ 00629 result = dhcp_discover(netif); 00630 if (result != ERR_OK) { 00631 /* free resources allocated above */ 00632 dhcp_stop(netif); 00633 return ERR_MEM; 00634 } 00635 /* Set the flag that says this netif is handled by DHCP. */ 00636 netif->flags |= NETIF_FLAG_DHCP; 00637 return result; 00638 } 00639 00640 /** 00641 * Inform a DHCP server of our manual configuration. 00642 * 00643 * This informs DHCP servers of our fixed IP address configuration 00644 * by sending an INFORM message. It does not involve DHCP address 00645 * configuration, it is just here to be nice to the network. 00646 * 00647 * @param netif The lwIP network interface 00648 */ 00649 void 00650 dhcp_inform(struct netif *netif) 00651 { 00652 struct dhcp *dhcp, *old_dhcp = netif->dhcp; 00653 err_t result = ERR_OK; 00654 dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp)); // static_cast<struct dhcp *>(x) 00655 if (dhcp == NULL) { 00656 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("dhcp_inform(): could not allocate dhcp\n")); 00657 return; 00658 } 00659 netif->dhcp = dhcp; 00660 memset(dhcp, 0, sizeof(struct dhcp)); 00661 00662 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_inform(): allocated dhcp\n")); 00663 dhcp->pcb = udp_new(); 00664 if (dhcp->pcb == NULL) { 00665 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("dhcp_inform(): could not obtain pcb")); 00666 mem_free((void *)dhcp); 00667 return; 00668 } 00669 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_inform(): created new udp pcb\n")); 00670 /* create and initialize the DHCP message header */ 00671 result = dhcp_create_request(netif); 00672 if (result == ERR_OK) { 00673 00674 dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); 00675 dhcp_option_byte(dhcp, DHCP_INFORM); 00676 00677 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 00678 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 00679 00680 dhcp_option_trailer(dhcp); 00681 00682 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 00683 00684 udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); 00685 udp_connect(dhcp->pcb, IP_ADDR_BROADCAST, DHCP_SERVER_PORT); 00686 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n")); 00687 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 00688 udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); 00689 dhcp_delete_request(netif); 00690 } else { 00691 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("dhcp_inform: could not allocate DHCP request\n")); 00692 } 00693 00694 if (dhcp->pcb != NULL) { 00695 udp_remove(dhcp->pcb); 00696 } 00697 dhcp->pcb = NULL; 00698 mem_free((void *)dhcp); 00699 netif->dhcp = old_dhcp; 00700 } 00701 00702 #if DHCP_DOES_ARP_CHECK 00703 /** 00704 * Match an ARP reply with the offered IP address. 00705 * 00706 * @param netif the network interface on which the reply was received 00707 * @param addr The IP address we received a reply from 00708 */ 00709 void dhcp_arp_reply(struct netif *netif, struct ip_addr *addr) 00710 { 00711 LWIP_ERROR("netif != NULL", (netif != NULL), return;); 00712 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 3, ("dhcp_arp_reply()\n")); 00713 /* is a DHCP client doing an ARP check? */ 00714 if ((netif->dhcp != NULL) && (netif->dhcp->state == DHCP_CHECKING)) { 00715 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_arp_reply(): CHECKING, arp reply for 0x%08"X32_F"\n", addr->addr)); 00716 /* did a host respond with the address we 00717 were offered by the DHCP server? */ 00718 if (ip_addr_cmp(addr, &netif->dhcp->offered_ip_addr)) { 00719 /* we will not accept the offered address */ 00720 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 1, ("dhcp_arp_reply(): arp reply matched with offered address, declining\n")); 00721 dhcp_decline(netif); 00722 } 00723 } 00724 } 00725 00726 /** 00727 * Decline an offered lease. 00728 * 00729 * Tell the DHCP server we do not accept the offered address. 00730 * One reason to decline the lease is when we find out the address 00731 * is already in use by another host (through ARP). 00732 * 00733 * @param netif the netif under DHCP control 00734 */ 00735 static err_t 00736 dhcp_decline(struct netif *netif) 00737 { 00738 struct dhcp *dhcp = netif->dhcp; 00739 err_t result = ERR_OK; 00740 u16_t msecs; 00741 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 3, ("dhcp_decline()\n")); 00742 dhcp_set_state(dhcp, DHCP_BACKING_OFF); 00743 /* create and initialize the DHCP message header */ 00744 result = dhcp_create_request(netif); 00745 if (result == ERR_OK) { 00746 dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); 00747 dhcp_option_byte(dhcp, DHCP_DECLINE); 00748 00749 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 00750 dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); 00751 00752 dhcp_option_trailer(dhcp); 00753 /* resize pbuf to reflect true size of options */ 00754 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 00755 00756 /* @todo: should we really connect here? we are performing sendto() */ 00757 udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); 00758 /* per section 4.4.4, broadcast DECLINE messages */ 00759 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 00760 dhcp_delete_request(netif); 00761 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_decline: BACKING OFF\n")); 00762 } else { 00763 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("dhcp_decline: could not allocate DHCP request\n")); 00764 } 00765 dhcp->tries++; 00766 msecs = 10*1000; 00767 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 00768 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs)); 00769 return result; 00770 } 00771 #endif 00772 00773 00774 /** 00775 * Start the DHCP process, discover a DHCP server. 00776 * 00777 * @param netif the netif under DHCP control 00778 */ 00779 static err_t 00780 dhcp_discover(struct netif *netif) 00781 { 00782 struct dhcp *dhcp = netif->dhcp; 00783 err_t result = ERR_OK; 00784 u16_t msecs; 00785 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 3, ("dhcp_discover()\n")); 00786 ip_addr_set(&dhcp->offered_ip_addr, IP_ADDR_ANY); 00787 /* create and initialize the DHCP message header */ 00788 result = dhcp_create_request(netif); 00789 if (result == ERR_OK) { 00790 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n")); 00791 dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); 00792 dhcp_option_byte(dhcp, DHCP_DISCOVER); 00793 00794 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 00795 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 00796 00797 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/); 00798 dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK); 00799 dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER); 00800 dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST); 00801 dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER); 00802 00803 dhcp_option_trailer(dhcp); 00804 00805 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: realloc()ing\n")); 00806 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 00807 00808 udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); 00809 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, DHCP_SERVER_PORT)\n")); 00810 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 00811 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()ing\n")); 00812 dhcp_delete_request(netif); 00813 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover: SELECTING\n")); 00814 dhcp_set_state(dhcp, DHCP_SELECTING); 00815 } else { 00816 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("dhcp_discover: could not allocate DHCP request\n")); 00817 } 00818 dhcp->tries++; 00819 #if LWIP_DHCP_AUTOIP_COOP 00820 /* that means we waited 57 seconds */ 00821 if(dhcp->tries >= 9 && dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_OFF) { 00822 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_ON; 00823 autoip_start(netif); 00824 } 00825 #endif /* LWIP_DHCP_AUTOIP_COOP */ 00826 msecs = dhcp->tries < 4 ? (dhcp->tries + 1) * 1000 : 10 * 1000; 00827 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 00828 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs)); 00829 return result; 00830 } 00831 00832 00833 /** 00834 * Bind the interface to the offered IP address. 00835 * 00836 * @param netif network interface to bind to the offered address 00837 */ 00838 static void 00839 dhcp_bind(struct netif *netif) 00840 { 00841 u32_t timeout; 00842 struct dhcp *dhcp; 00843 struct ip_addr sn_mask, gw_addr; 00844 LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;); 00845 dhcp = netif->dhcp; 00846 LWIP_ERROR("dhcp_bind: dhcp != NULL", (dhcp != NULL), return;); 00847 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 3, ("dhcp_bind(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); 00848 00849 /* temporary DHCP lease? */ 00850 if (dhcp->offered_t1_renew != 0xffffffffUL) { 00851 /* set renewal period timer */ 00852 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew)); 00853 timeout = (dhcp->offered_t1_renew + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; 00854 if(timeout > 0xffff) { 00855 timeout = 0xffff; 00856 } 00857 dhcp->t1_timeout = (u16_t)timeout; 00858 if (dhcp->t1_timeout == 0) { 00859 dhcp->t1_timeout = 1; 00860 } 00861 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew*1000)); 00862 } 00863 /* set renewal period timer */ 00864 if (dhcp->offered_t2_rebind != 0xffffffffUL) { 00865 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind)); 00866 timeout = (dhcp->offered_t2_rebind + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; 00867 if(timeout > 0xffff) { 00868 timeout = 0xffff; 00869 } 00870 dhcp->t2_timeout = (u16_t)timeout; 00871 if (dhcp->t2_timeout == 0) { 00872 dhcp->t2_timeout = 1; 00873 } 00874 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t2_rebind*1000)); 00875 } 00876 /* copy offered network mask */ 00877 ip_addr_set(&sn_mask, &dhcp->offered_sn_mask); 00878 00879 /* subnet mask not given? */ 00880 /* TODO: this is not a valid check. what if the network mask is 0? */ 00881 if (sn_mask.addr == 0) { 00882 /* choose a safe subnet mask given the network class */ 00883 u8_t first_octet = ip4_addr1(&sn_mask); 00884 if (first_octet <= 127) { 00885 sn_mask.addr = htonl(0xff000000); 00886 } else if (first_octet >= 192) { 00887 sn_mask.addr = htonl(0xffffff00); 00888 } else { 00889 sn_mask.addr = htonl(0xffff0000); 00890 } 00891 } 00892 00893 ip_addr_set(&gw_addr, &dhcp->offered_gw_addr); 00894 /* gateway address not given? */ 00895 if (gw_addr.addr == 0) { 00896 /* copy network address */ 00897 gw_addr.addr = (dhcp->offered_ip_addr.addr & sn_mask.addr); 00898 /* use first host address on network as gateway */ 00899 gw_addr.addr |= htonl(0x00000001); 00900 } 00901 00902 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): IP: 0x%08"X32_F"\n", dhcp->offered_ip_addr.addr)); 00903 netif_set_ipaddr(netif, &dhcp->offered_ip_addr); 00904 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): SN: 0x%08"X32_F"\n", sn_mask.addr)); 00905 netif_set_netmask(netif, &sn_mask); 00906 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): GW: 0x%08"X32_F"\n", gw_addr.addr)); 00907 netif_set_gw(netif, &gw_addr); 00908 /* bring the interface up */ 00909 netif_set_up(netif); 00910 /* netif is now bound to DHCP leased address */ 00911 dhcp_set_state(dhcp, DHCP_BOUND); 00912 } 00913 00914 /** 00915 * Renew an existing DHCP lease at the involved DHCP server. 00916 * 00917 * @param netif network interface which must renew its lease 00918 */ 00919 err_t 00920 dhcp_renew(struct netif *netif) 00921 { 00922 struct dhcp *dhcp = netif->dhcp; 00923 err_t result; 00924 u16_t msecs; 00925 #if LWIP_NETIF_HOSTNAME 00926 const char *p; 00927 #endif /* LWIP_NETIF_HOSTNAME */ 00928 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 3, ("dhcp_renew()\n")); 00929 dhcp_set_state(dhcp, DHCP_RENEWING); 00930 00931 /* create and initialize the DHCP message header */ 00932 result = dhcp_create_request(netif); 00933 if (result == ERR_OK) { 00934 00935 dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); 00936 dhcp_option_byte(dhcp, DHCP_REQUEST); 00937 00938 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 00939 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 00940 00941 #if LWIP_NETIF_HOSTNAME 00942 p = (const char*)netif->hostname; 00943 if (p != NULL) { 00944 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, strlen(p)); 00945 while (*p) { 00946 dhcp_option_byte(dhcp, *p++); 00947 } 00948 } 00949 #endif /* LWIP_NETIF_HOSTNAME */ 00950 00951 #if 0 00952 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 00953 dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); 00954 #endif 00955 00956 #if 0 00957 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); 00958 dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr)); 00959 #endif 00960 /* append DHCP message trailer */ 00961 dhcp_option_trailer(dhcp); 00962 00963 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 00964 00965 udp_connect(dhcp->pcb, &dhcp->server_ip_addr, DHCP_SERVER_PORT); 00966 udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif); 00967 dhcp_delete_request(netif); 00968 00969 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew: RENEWING\n")); 00970 } else { 00971 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("dhcp_renew: could not allocate DHCP request\n")); 00972 } 00973 dhcp->tries++; 00974 /* back-off on retries, but to a maximum of 20 seconds */ 00975 msecs = dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000; 00976 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 00977 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs)); 00978 return result; 00979 } 00980 00981 /** 00982 * Rebind with a DHCP server for an existing DHCP lease. 00983 * 00984 * @param netif network interface which must rebind with a DHCP server 00985 */ 00986 static err_t 00987 dhcp_rebind(struct netif *netif) 00988 { 00989 struct dhcp *dhcp = netif->dhcp; 00990 err_t result; 00991 u16_t msecs; 00992 #if LWIP_NETIF_HOSTNAME 00993 const char *p; 00994 #endif /* LWIP_NETIF_HOSTNAME */ 00995 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n")); 00996 dhcp_set_state(dhcp, DHCP_REBINDING); 00997 00998 /* create and initialize the DHCP message header */ 00999 result = dhcp_create_request(netif); 01000 if (result == ERR_OK) { 01001 01002 dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); 01003 dhcp_option_byte(dhcp, DHCP_REQUEST); 01004 01005 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 01006 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 01007 01008 #if LWIP_NETIF_HOSTNAME 01009 p = (const char*)netif->hostname; 01010 if (p != NULL) { 01011 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, strlen(p)); 01012 while (*p) { 01013 dhcp_option_byte(dhcp, *p++); 01014 } 01015 } 01016 #endif /* LWIP_NETIF_HOSTNAME */ 01017 01018 #if 0 01019 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 01020 dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); 01021 01022 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); 01023 dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr)); 01024 #endif 01025 01026 dhcp_option_trailer(dhcp); 01027 01028 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 01029 01030 /* broadcast to server */ 01031 udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); 01032 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 01033 dhcp_delete_request(netif); 01034 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n")); 01035 } else { 01036 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("dhcp_rebind: could not allocate DHCP request\n")); 01037 } 01038 dhcp->tries++; 01039 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; 01040 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 01041 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs)); 01042 return result; 01043 } 01044 01045 /** 01046 * Release a DHCP lease. 01047 * 01048 * @param netif network interface which must release its lease 01049 */ 01050 err_t 01051 dhcp_release(struct netif *netif) 01052 { 01053 struct dhcp *dhcp = netif->dhcp; 01054 err_t result; 01055 u16_t msecs; 01056 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 3, ("dhcp_release()\n")); 01057 01058 /* idle DHCP client */ 01059 dhcp_set_state(dhcp, DHCP_OFF); 01060 /* clean old DHCP offer */ 01061 dhcp->server_ip_addr.addr = 0; 01062 dhcp->offered_ip_addr.addr = dhcp->offered_sn_mask.addr = 0; 01063 dhcp->offered_gw_addr.addr = dhcp->offered_bc_addr.addr = 0; 01064 dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0; 01065 dhcp->dns_count = 0; 01066 01067 /* create and initialize the DHCP message header */ 01068 result = dhcp_create_request(netif); 01069 if (result == ERR_OK) { 01070 dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); 01071 dhcp_option_byte(dhcp, DHCP_RELEASE); 01072 01073 dhcp_option_trailer(dhcp); 01074 01075 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 01076 01077 udp_connect(dhcp->pcb, &dhcp->server_ip_addr, DHCP_SERVER_PORT); 01078 udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif); 01079 dhcp_delete_request(netif); 01080 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_OFF\n")); 01081 } else { 01082 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("dhcp_release: could not allocate DHCP request\n")); 01083 } 01084 dhcp->tries++; 01085 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; 01086 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 01087 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release(): set request timeout %"U16_F" msecs\n", msecs)); 01088 /* bring the interface down */ 01089 netif_set_down(netif); 01090 /* remove IP address from interface */ 01091 netif_set_ipaddr(netif, IP_ADDR_ANY); 01092 netif_set_gw(netif, IP_ADDR_ANY); 01093 netif_set_netmask(netif, IP_ADDR_ANY); 01094 01095 /* TODO: netif_down(netif); */ 01096 return result; 01097 } 01098 01099 /** 01100 * Remove the DHCP client from the interface. 01101 * 01102 * @param netif The network interface to stop DHCP on 01103 */ 01104 void 01105 dhcp_stop(struct netif *netif) 01106 { 01107 struct dhcp *dhcp = netif->dhcp; 01108 LWIP_ERROR("dhcp_stop: netif != NULL", (netif != NULL), return;); 01109 /* Remove the flag that says this netif is handled by DHCP. */ 01110 netif->flags &= ~NETIF_FLAG_DHCP; 01111 01112 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 3, ("dhcp_stop()\n")); 01113 /* netif is DHCP configured? */ 01114 if (dhcp != NULL) { 01115 if (dhcp->pcb != NULL) { 01116 udp_remove(dhcp->pcb); 01117 dhcp->pcb = NULL; 01118 } 01119 if (dhcp->p != NULL) { 01120 pbuf_free(dhcp->p); 01121 dhcp->p = NULL; 01122 } 01123 /* free unfolded reply */ 01124 dhcp_free_reply(dhcp); 01125 mem_free((void *)dhcp); 01126 netif->dhcp = NULL; 01127 } 01128 } 01129 01130 /* 01131 * Set the DHCP state of a DHCP client. 01132 * 01133 * If the state changed, reset the number of tries. 01134 * 01135 * TODO: we might also want to reset the timeout here? 01136 */ 01137 static void 01138 dhcp_set_state(struct dhcp *dhcp, u8_t new_state) 01139 { 01140 if (new_state != dhcp->state) { 01141 dhcp->state = new_state; 01142 dhcp->tries = 0; 01143 } 01144 } 01145 01146 /* 01147 * Concatenate an option type and length field to the outgoing 01148 * DHCP message. 01149 * 01150 */ 01151 static void 01152 dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len) 01153 { 01154 LWIP_ASSERT("dhcp_option: dhcp->options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN); 01155 dhcp->msg_out->options[dhcp->options_out_len++] = option_type; 01156 dhcp->msg_out->options[dhcp->options_out_len++] = option_len; 01157 } 01158 /* 01159 * Concatenate a single byte to the outgoing DHCP message. 01160 * 01161 */ 01162 static void 01163 dhcp_option_byte(struct dhcp *dhcp, u8_t value) 01164 { 01165 LWIP_ASSERT("dhcp_option_byte: dhcp->options_out_len < DHCP_OPTIONS_LEN", dhcp->options_out_len < DHCP_OPTIONS_LEN); 01166 dhcp->msg_out->options[dhcp->options_out_len++] = value; 01167 } 01168 01169 static void 01170 dhcp_option_short(struct dhcp *dhcp, u16_t value) 01171 { 01172 LWIP_ASSERT("dhcp_option_short: dhcp->options_out_len + 2 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U <= DHCP_OPTIONS_LEN); 01173 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff00U) >> 8); 01174 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t) (value & 0x00ffU); 01175 } 01176 01177 static void 01178 dhcp_option_long(struct dhcp *dhcp, u32_t value) 01179 { 01180 LWIP_ASSERT("dhcp_option_long: dhcp->options_out_len + 4 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 4U <= DHCP_OPTIONS_LEN); 01181 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24); 01182 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16); 01183 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8); 01184 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x000000ffUL)); 01185 } 01186 01187 /** 01188 * Extract the DHCP message and the DHCP options. 01189 * 01190 * Extract the DHCP message and the DHCP options, each into a contiguous 01191 * piece of memory. As a DHCP message is variable sized by its options, 01192 * and also allows overriding some fields for options, the easy approach 01193 * is to first unfold the options into a conitguous piece of memory, and 01194 * use that further on. 01195 * 01196 */ 01197 static err_t 01198 dhcp_unfold_reply(struct dhcp *dhcp) 01199 { 01200 u16_t ret; 01201 LWIP_ERROR("dhcp != NULL", (dhcp != NULL), return ERR_ARG;); 01202 LWIP_ERROR("dhcp->p != NULL", (dhcp->p != NULL), return ERR_VAL;); 01203 /* free any left-overs from previous unfolds */ 01204 dhcp_free_reply(dhcp); 01205 /* options present? */ 01206 if (dhcp->p->tot_len > (sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN)) { 01207 dhcp->options_in_len = dhcp->p->tot_len - (sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN); 01208 dhcp->options_in = (struct dhcp_msg *)mem_malloc(dhcp->options_in_len); // static_cast<struct dhcp_msg *>(x) 01209 if (dhcp->options_in == NULL) { 01210 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("dhcp_unfold_reply(): could not allocate dhcp->options\n")); 01211 return ERR_MEM; 01212 } 01213 } 01214 dhcp->msg_in = (struct dhcp_msg *)mem_malloc(sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN); // static_cast<struct dhcp_msg *>(x) 01215 if (dhcp->msg_in == NULL) { 01216 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("dhcp_unfold_reply(): could not allocate dhcp->msg_in\n")); 01217 mem_free((void *)dhcp->options_in); 01218 dhcp->options_in = NULL; 01219 return ERR_MEM; 01220 } 01221 01222 /** copy the DHCP message without options */ 01223 ret = pbuf_copy_partial(dhcp->p, dhcp->msg_in, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN, 0); 01224 LWIP_ASSERT("ret == sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN", ret == sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN); 01225 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_unfold_reply(): copied %"U16_F" bytes into dhcp->msg_in[]\n", 01226 sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN)); 01227 01228 if (dhcp->options_in != NULL) { 01229 /** copy the DHCP options */ 01230 ret = pbuf_copy_partial(dhcp->p, dhcp->options_in, dhcp->options_in_len, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN); 01231 LWIP_ASSERT("ret == dhcp->options_in_len", ret == dhcp->options_in_len); 01232 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_unfold_reply(): copied %"U16_F" bytes to dhcp->options_in[]\n", 01233 dhcp->options_in_len)); 01234 } 01235 LWIP_UNUSED_ARG(ret); 01236 return ERR_OK; 01237 } 01238 01239 /** 01240 * Free the incoming DHCP message including contiguous copy of 01241 * its DHCP options. 01242 * 01243 */ 01244 static void dhcp_free_reply(struct dhcp *dhcp) 01245 { 01246 if (dhcp->msg_in != NULL) { 01247 mem_free((void *)dhcp->msg_in); 01248 dhcp->msg_in = NULL; 01249 } 01250 if (dhcp->options_in) { 01251 mem_free((void *)dhcp->options_in); 01252 dhcp->options_in = NULL; 01253 dhcp->options_in_len = 0; 01254 } 01255 LWIP_DEBUGF(DHCP_DEBUG, ("dhcp_free_reply(): free'd\n")); 01256 } 01257 01258 01259 /** 01260 * If an incoming DHCP message is in response to us, then trigger the state machine 01261 */ 01262 static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port) 01263 { 01264 struct netif *netif = (struct netif *)arg; 01265 struct dhcp *dhcp = netif->dhcp; 01266 struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload; 01267 u8_t *options_ptr; 01268 u8_t msg_type; 01269 u8_t i; 01270 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 3, ("dhcp_recv(pbuf = %p) from DHCP server %"U16_F".%"U16_F".%"U16_F".%"U16_F" port %"U16_F"\n", (void*)p, 01271 (u16_t)(ntohl(addr->addr) >> 24 & 0xff), (u16_t)(ntohl(addr->addr) >> 16 & 0xff), 01272 (u16_t)(ntohl(addr->addr) >> 8 & 0xff), (u16_t)(ntohl(addr->addr) & 0xff), port)); 01273 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len)); 01274 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len)); 01275 /* prevent warnings about unused arguments */ 01276 LWIP_UNUSED_ARG(pcb); 01277 LWIP_UNUSED_ARG(addr); 01278 LWIP_UNUSED_ARG(port); 01279 dhcp->p = p; 01280 /* TODO: check packet length before reading them */ 01281 if (reply_msg->op != DHCP_BOOTREPLY) { 01282 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 1, ("not a DHCP reply message, but type %"U16_F"\n", (u16_t)reply_msg->op)); 01283 goto free_pbuf_and_return; 01284 } 01285 /* iterate through hardware address and match against DHCP message */ 01286 for (i = 0; i < netif->hwaddr_len; i++) { 01287 if (netif->hwaddr[i] != reply_msg->chaddr[i]) { 01288 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n", 01289 (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i])); 01290 goto free_pbuf_and_return; 01291 } 01292 } 01293 /* match transaction ID against what we expected */ 01294 if (ntohl(reply_msg->xid) != dhcp->xid) { 01295 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("transaction id mismatch reply_msg->xid(%"X32_F")!=dhcp->xid(%"X32_F")\n",ntohl(reply_msg->xid),dhcp->xid)); 01296 goto free_pbuf_and_return; 01297 } 01298 /* option fields could be unfold? */ 01299 if (dhcp_unfold_reply(dhcp) != ERR_OK) { 01300 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("problem unfolding DHCP message - too short on memory?\n")); 01301 goto free_pbuf_and_return; 01302 } 01303 01304 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n")); 01305 /* obtain pointer to DHCP message type */ 01306 options_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_MESSAGE_TYPE); 01307 if (options_ptr == NULL) { 01308 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 1, ("DHCP_OPTION_MESSAGE_TYPE option not found\n")); 01309 goto free_pbuf_and_return; 01310 } 01311 01312 /* read DHCP message type */ 01313 msg_type = dhcp_get_option_byte(options_ptr + 2); 01314 /* message type is DHCP ACK? */ 01315 if (msg_type == DHCP_ACK) { 01316 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 1, ("DHCP_ACK received\n")); 01317 /* in requesting state? */ 01318 if (dhcp->state == DHCP_REQUESTING) { 01319 dhcp_handle_ack(netif); 01320 dhcp->request_timeout = 0; 01321 #if DHCP_DOES_ARP_CHECK 01322 /* check if the acknowledged lease address is already in use */ 01323 dhcp_check(netif); 01324 #else 01325 /* bind interface to the acknowledged lease address */ 01326 dhcp_bind(netif); 01327 #endif 01328 } 01329 /* already bound to the given lease address? */ 01330 else if ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING)) { 01331 dhcp->request_timeout = 0; 01332 dhcp_bind(netif); 01333 } 01334 } 01335 /* received a DHCP_NAK in appropriate state? */ 01336 else if ((msg_type == DHCP_NAK) && 01337 ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REQUESTING) || 01338 (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING ))) { 01339 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 1, ("DHCP_NAK received\n")); 01340 dhcp->request_timeout = 0; 01341 dhcp_handle_nak(netif); 01342 } 01343 /* received a DHCP_OFFER in DHCP_SELECTING state? */ 01344 else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_SELECTING)) { 01345 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 1, ("DHCP_OFFER received in DHCP_SELECTING state\n")); 01346 dhcp->request_timeout = 0; 01347 /* remember offered lease */ 01348 dhcp_handle_offer(netif); 01349 } 01350 free_pbuf_and_return: 01351 dhcp_free_reply(dhcp); 01352 pbuf_free(p); 01353 dhcp->p = NULL; 01354 } 01355 01356 /** 01357 * Create a DHCP request, fill in common headers 01358 * 01359 * @param netif the netif under DHCP control 01360 */ 01361 static err_t 01362 dhcp_create_request(struct netif *netif) 01363 { 01364 struct dhcp *dhcp; 01365 u16_t i; 01366 #ifndef DHCP_GLOBAL_XID 01367 /** default global transaction identifier starting value (easy to match 01368 * with a packet analyser). We simply increment for each new request. 01369 * Predefine DHCP_GLOBAL_XID to a better value or a function call to generate one 01370 * at runtime, any supporting function prototypes can be defined in DHCP_GLOBAL_XID_HEADER */ 01371 static u32_t xid = 0xABCD0000; 01372 #else 01373 static u32_t xid; 01374 static u8_t xid_initialised = 0; 01375 if (!xid_initialised) { 01376 xid = DHCP_GLOBAL_XID; 01377 xid_initialised = !xid_initialised; 01378 } 01379 #endif 01380 LWIP_ERROR("dhcp_create_request: netif != NULL", (netif != NULL), return ERR_ARG;); 01381 dhcp = netif->dhcp; 01382 LWIP_ERROR("dhcp_create_request: dhcp != NULL", (dhcp != NULL), return ERR_VAL;); 01383 LWIP_ASSERT("dhcp_create_request: dhcp->p_out == NULL", dhcp->p_out == NULL); 01384 LWIP_ASSERT("dhcp_create_request: dhcp->msg_out == NULL", dhcp->msg_out == NULL); 01385 dhcp->p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM); 01386 if (dhcp->p_out == NULL) { 01387 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("dhcp_create_request(): could not allocate pbuf\n")); 01388 return ERR_MEM; 01389 } 01390 LWIP_ASSERT("dhcp_create_request: check that first pbuf can hold struct dhcp_msg", 01391 (dhcp->p_out->len >= sizeof(struct dhcp_msg))); 01392 01393 /* give unique transaction identifier to this request */ 01394 dhcp->xid = xid++; 01395 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("transaction id xid++(%"X32_F") dhcp->xid(%"U32_F")\n",xid,dhcp->xid)); 01396 01397 dhcp->msg_out = (struct dhcp_msg *)dhcp->p_out->payload; 01398 01399 dhcp->msg_out->op = DHCP_BOOTREQUEST; 01400 /* TODO: make link layer independent */ 01401 dhcp->msg_out->htype = DHCP_HTYPE_ETH; 01402 /* TODO: make link layer independent */ 01403 dhcp->msg_out->hlen = DHCP_HLEN_ETH; 01404 dhcp->msg_out->hops = 0; 01405 dhcp->msg_out->xid = htonl(dhcp->xid); 01406 dhcp->msg_out->secs = 0; 01407 dhcp->msg_out->flags = 0; 01408 dhcp->msg_out->ciaddr.addr = netif->ip_addr.addr; 01409 dhcp->msg_out->yiaddr.addr = 0; 01410 dhcp->msg_out->siaddr.addr = 0; 01411 dhcp->msg_out->giaddr.addr = 0; 01412 for (i = 0; i < DHCP_CHADDR_LEN; i++) { 01413 /* copy netif hardware address, pad with zeroes */ 01414 dhcp->msg_out->chaddr[i] = (i < netif->hwaddr_len) ? netif->hwaddr[i] : 0/* pad byte*/; 01415 } 01416 for (i = 0; i < DHCP_SNAME_LEN; i++) { 01417 dhcp->msg_out->sname[i] = 0; 01418 } 01419 for (i = 0; i < DHCP_FILE_LEN; i++) { 01420 dhcp->msg_out->file[i] = 0; 01421 } 01422 dhcp->msg_out->cookie = htonl(0x63825363UL); 01423 dhcp->options_out_len = 0; 01424 /* fill options field with an incrementing array (for debugging purposes) */ 01425 for (i = 0; i < DHCP_OPTIONS_LEN; i++) { 01426 dhcp->msg_out->options[i] = (u8_t)i; /* for debugging only, no matter if truncated */ 01427 } 01428 return ERR_OK; 01429 } 01430 01431 /** 01432 * Free previously allocated memory used to send a DHCP request. 01433 * 01434 * @param netif the netif under DHCP control 01435 */ 01436 static void 01437 dhcp_delete_request(struct netif *netif) 01438 { 01439 struct dhcp *dhcp; 01440 LWIP_ERROR("dhcp_delete_request: netif != NULL", (netif != NULL), return;); 01441 dhcp = netif->dhcp; 01442 LWIP_ERROR("dhcp_delete_request: dhcp != NULL", (dhcp != NULL), return;); 01443 LWIP_ASSERT("dhcp_delete_request: dhcp->p_out != NULL", dhcp->p_out != NULL); 01444 LWIP_ASSERT("dhcp_delete_request: dhcp->msg_out != NULL", dhcp->msg_out != NULL); 01445 if (dhcp->p_out != NULL) { 01446 pbuf_free(dhcp->p_out); 01447 } 01448 dhcp->p_out = NULL; 01449 dhcp->msg_out = NULL; 01450 } 01451 01452 /** 01453 * Add a DHCP message trailer 01454 * 01455 * Adds the END option to the DHCP message, and if 01456 * necessary, up to three padding bytes. 01457 * 01458 * @param dhcp DHCP state structure 01459 */ 01460 static void 01461 dhcp_option_trailer(struct dhcp *dhcp) 01462 { 01463 LWIP_ERROR("dhcp_option_trailer: dhcp != NULL", (dhcp != NULL), return;); 01464 LWIP_ASSERT("dhcp_option_trailer: dhcp->msg_out != NULL\n", dhcp->msg_out != NULL); 01465 LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN); 01466 dhcp->msg_out->options[dhcp->options_out_len++] = DHCP_OPTION_END; 01467 /* packet is too small, or not 4 byte aligned? */ 01468 while ((dhcp->options_out_len < DHCP_MIN_OPTIONS_LEN) || (dhcp->options_out_len & 3)) { 01469 /* LWIP_DEBUGF(DHCP_DEBUG,("dhcp_option_trailer:dhcp->options_out_len=%"U16_F", DHCP_OPTIONS_LEN=%"U16_F, dhcp->options_out_len, DHCP_OPTIONS_LEN)); */ 01470 LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN); 01471 /* add a fill/padding byte */ 01472 dhcp->msg_out->options[dhcp->options_out_len++] = 0; 01473 } 01474 } 01475 01476 /** 01477 * Find the offset of a DHCP option inside the DHCP message. 01478 * 01479 * @param dhcp DHCP client 01480 * @param option_type 01481 * 01482 * @return a byte offset into the UDP message where the option was found, or 01483 * zero if the given option was not found. 01484 */ 01485 static u8_t *dhcp_get_option_ptr(struct dhcp *dhcp, u8_t option_type) 01486 { 01487 u8_t overload = DHCP_OVERLOAD_NONE; 01488 01489 /* options available? */ 01490 if ((dhcp->options_in != NULL) && (dhcp->options_in_len > 0)) { 01491 /* start with options field */ 01492 u8_t *options = (u8_t *)dhcp->options_in; 01493 u16_t offset = 0; 01494 /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */ 01495 while ((offset < dhcp->options_in_len) && (options[offset] != DHCP_OPTION_END)) { 01496 /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F, msg_offset, q->len)); */ 01497 /* are the sname and/or file field overloaded with options? */ 01498 if (options[offset] == DHCP_OPTION_OVERLOAD) { 01499 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("overloaded message detected\n")); 01500 /* skip option type and length */ 01501 offset += 2; 01502 overload = options[offset++]; 01503 } 01504 /* requested option found */ 01505 else if (options[offset] == option_type) { 01506 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("option found at offset %"U16_F" in options\n", offset)); 01507 return &options[offset]; 01508 /* skip option */ 01509 } else { 01510 LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", options[offset])); 01511 /* skip option type */ 01512 offset++; 01513 /* skip option length, and then length bytes */ 01514 offset += 1 + options[offset]; 01515 } 01516 } 01517 /* is this an overloaded message? */ 01518 if (overload != DHCP_OVERLOAD_NONE) { 01519 u16_t field_len; 01520 if (overload == DHCP_OVERLOAD_FILE) { 01521 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 1, ("overloaded file field\n")); 01522 options = (u8_t *)&dhcp->msg_in->file; 01523 field_len = DHCP_FILE_LEN; 01524 } else if (overload == DHCP_OVERLOAD_SNAME) { 01525 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 1, ("overloaded sname field\n")); 01526 options = (u8_t *)&dhcp->msg_in->sname; 01527 field_len = DHCP_SNAME_LEN; 01528 /* TODO: check if else if () is necessary */ 01529 } else { 01530 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 1, ("overloaded sname and file field\n")); 01531 options = (u8_t *)&dhcp->msg_in->sname; 01532 field_len = DHCP_FILE_LEN + DHCP_SNAME_LEN; 01533 } 01534 offset = 0; 01535 01536 /* at least 1 byte to read and no end marker */ 01537 while ((offset < field_len) && (options[offset] != DHCP_OPTION_END)) { 01538 if (options[offset] == option_type) { 01539 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("option found at offset=%"U16_F"\n", offset)); 01540 return &options[offset]; 01541 /* skip option */ 01542 } else { 01543 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("skipping option %"U16_F"\n", options[offset])); 01544 /* skip option type */ 01545 offset++; 01546 offset += 1 + options[offset]; 01547 } 01548 } 01549 } 01550 } 01551 return NULL; 01552 } 01553 01554 /** 01555 * Return the byte of DHCP option data. 01556 * 01557 * @param client DHCP client. 01558 * @param ptr pointer obtained by dhcp_get_option_ptr(). 01559 * 01560 * @return byte value at the given address. 01561 */ 01562 static u8_t 01563 dhcp_get_option_byte(u8_t *ptr) 01564 { 01565 LWIP_DEBUGF(DHCP_DEBUG, ("option byte value=%"U16_F"\n", (u16_t)(*ptr))); 01566 return *ptr; 01567 } 01568 01569 #if 0 /* currently unused */ 01570 /** 01571 * Return the 16-bit value of DHCP option data. 01572 * 01573 * @param client DHCP client. 01574 * @param ptr pointer obtained by dhcp_get_option_ptr(). 01575 * 01576 * @return byte value at the given address. 01577 */ 01578 static u16_t 01579 dhcp_get_option_short(u8_t *ptr) 01580 { 01581 u16_t value; 01582 value = *ptr++ << 8; 01583 value |= *ptr; 01584 LWIP_DEBUGF(DHCP_DEBUG, ("option short value=%"U16_F"\n", value)); 01585 return value; 01586 } 01587 #endif 01588 01589 /** 01590 * Return the 32-bit value of DHCP option data. 01591 * 01592 * @param client DHCP client. 01593 * @param ptr pointer obtained by dhcp_get_option_ptr(). 01594 * 01595 * @return byte value at the given address. 01596 */ 01597 static u32_t dhcp_get_option_long(u8_t *ptr) 01598 { 01599 u32_t value; 01600 value = (u32_t)(*ptr++) << 24; 01601 value |= (u32_t)(*ptr++) << 16; 01602 value |= (u32_t)(*ptr++) << 8; 01603 value |= (u32_t)(*ptr++); 01604 LWIP_DEBUGF(DHCP_DEBUG, ("option long value=%"U32_F"\n", value)); 01605 return value; 01606 } 01607 01608 #endif /* LWIP_DHCP */
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