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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 * - Support for interfaces other than Ethernet (SLIP, PPP, ...) 00047 * 00048 * Please coordinate changes and requests with Leon Woestenberg 00049 * <leon.woestenberg@gmx.net> 00050 * 00051 * Integration with your code: 00052 * 00053 * In lwip/dhcp.h 00054 * #define DHCP_COARSE_TIMER_SECS (recommended 60 which is a minute) 00055 * #define DHCP_FINE_TIMER_MSECS (recommended 500 which equals TCP coarse timer) 00056 * 00057 * Then have your application call dhcp_coarse_tmr() and 00058 * dhcp_fine_tmr() on the defined intervals. 00059 * 00060 * dhcp_start(struct netif *netif); 00061 * starts a DHCP client instance which configures the interface by 00062 * obtaining an IP address lease and maintaining it. 00063 * 00064 * Use dhcp_release(netif) to end the lease and use dhcp_stop(netif) 00065 * to remove the DHCP client. 00066 * 00067 */ 00068 00069 #include "lwip/opt.h" 00070 00071 #if LWIP_DHCP /* don't build if not configured for use in lwipopts.h */ 00072 00073 #include "lwip/stats.h" 00074 #include "lwip/mem.h" 00075 #include "lwip/udp.h" 00076 #include "lwip/ip_addr.h" 00077 #include "lwip/netif.h" 00078 #include "lwip/def.h" 00079 #include "lwip/sys.h" 00080 #include "lwip/dhcp.h" 00081 #include "lwip/autoip.h" 00082 #include "lwip/dns.h" 00083 #include "netif/etharp.h" 00084 00085 #include <string.h> 00086 00087 /** Default for DHCP_GLOBAL_XID is 0xABCD0000 00088 * This can be changed by defining DHCP_GLOBAL_XID and DHCP_GLOBAL_XID_HEADER, e.g. 00089 * #define DHCP_GLOBAL_XID_HEADER "stdlib.h" 00090 * #define DHCP_GLOBAL_XID rand() 00091 */ 00092 #ifdef DHCP_GLOBAL_XID_HEADER 00093 #include DHCP_GLOBAL_XID_HEADER /* include optional starting XID generation prototypes */ 00094 #endif 00095 00096 /** DHCP_OPTION_MAX_MSG_SIZE is set to the MTU 00097 * MTU is checked to be big enough in dhcp_start */ 00098 #define DHCP_MAX_MSG_LEN(netif) (netif->mtu) 00099 #define DHCP_MAX_MSG_LEN_MIN_REQUIRED 576 00100 /** Minimum length for reply before packet is parsed */ 00101 #define DHCP_MIN_REPLY_LEN 44 00102 00103 #define REBOOT_TRIES 2 00104 00105 /** Option handling: options are parsed in dhcp_parse_reply 00106 * and saved in an array where other functions can load them from. 00107 * This might be moved into the struct dhcp (not necessarily since 00108 * lwIP is single-threaded and the array is only used while in recv 00109 * callback). */ 00110 #define DHCP_OPTION_IDX_OVERLOAD 0 00111 #define DHCP_OPTION_IDX_MSG_TYPE 1 00112 #define DHCP_OPTION_IDX_SERVER_ID 2 00113 #define DHCP_OPTION_IDX_LEASE_TIME 3 00114 #define DHCP_OPTION_IDX_T1 4 00115 #define DHCP_OPTION_IDX_T2 5 00116 #define DHCP_OPTION_IDX_SUBNET_MASK 6 00117 #define DHCP_OPTION_IDX_ROUTER 7 00118 #define DHCP_OPTION_IDX_DNS_SERVER 8 00119 #define DHCP_OPTION_IDX_MAX (DHCP_OPTION_IDX_DNS_SERVER + DNS_MAX_SERVERS) 00120 00121 /** Holds the decoded option values, only valid while in dhcp_recv. 00122 @todo: move this into struct dhcp? */ 00123 u32_t dhcp_rx_options_val[DHCP_OPTION_IDX_MAX]; 00124 /** Holds a flag which option was received and is contained in dhcp_rx_options_val, 00125 only valid while in dhcp_recv. 00126 @todo: move this into struct dhcp? */ 00127 u8_t dhcp_rx_options_given[DHCP_OPTION_IDX_MAX]; 00128 00129 #define dhcp_option_given(dhcp, idx) (dhcp_rx_options_given[idx] != 0) 00130 #define dhcp_got_option(dhcp, idx) (dhcp_rx_options_given[idx] = 1) 00131 #define dhcp_clear_option(dhcp, idx) (dhcp_rx_options_given[idx] = 0) 00132 #define dhcp_clear_all_options(dhcp) (memset(dhcp_rx_options_given, 0, sizeof(dhcp_rx_options_given))) 00133 #define dhcp_get_option_value(dhcp, idx) (dhcp_rx_options_val[idx]) 00134 #define dhcp_set_option_value(dhcp, idx, val) (dhcp_rx_options_val[idx] = (val)) 00135 00136 00137 /* DHCP client state machine functions */ 00138 static err_t dhcp_discover(struct netif *netif); 00139 static err_t dhcp_select(struct netif *netif); 00140 static void dhcp_bind(struct netif *netif); 00141 #if DHCP_DOES_ARP_CHECK 00142 static err_t dhcp_decline(struct netif *netif); 00143 #endif /* DHCP_DOES_ARP_CHECK */ 00144 static err_t dhcp_rebind(struct netif *netif); 00145 static err_t dhcp_reboot(struct netif *netif); 00146 static void dhcp_set_state(struct dhcp *dhcp, u8_t new_state); 00147 00148 /* receive, unfold, parse and free incoming messages */ 00149 static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port); 00150 00151 /* set the DHCP timers */ 00152 static void dhcp_timeout(struct netif *netif); 00153 static void dhcp_t1_timeout(struct netif *netif); 00154 static void dhcp_t2_timeout(struct netif *netif); 00155 00156 /* build outgoing messages */ 00157 /* create a DHCP message, fill in common headers */ 00158 static err_t dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type); 00159 /* free a DHCP request */ 00160 static void dhcp_delete_msg(struct dhcp *dhcp); 00161 /* add a DHCP option (type, then length in bytes) */ 00162 static void dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len); 00163 /* add option values */ 00164 static void dhcp_option_byte(struct dhcp *dhcp, u8_t value); 00165 static void dhcp_option_short(struct dhcp *dhcp, u16_t value); 00166 static void dhcp_option_long(struct dhcp *dhcp, u32_t value); 00167 /* always add the DHCP options trailer to end and pad */ 00168 static void dhcp_option_trailer(struct dhcp *dhcp); 00169 00170 /** 00171 * Back-off the DHCP client (because of a received NAK response). 00172 * 00173 * Back-off the DHCP client because of a received NAK. Receiving a 00174 * NAK means the client asked for something non-sensible, for 00175 * example when it tries to renew a lease obtained on another network. 00176 * 00177 * We clear any existing set IP address and restart DHCP negotiation 00178 * afresh (as per RFC2131 3.2.3). 00179 * 00180 * @param netif the netif under DHCP control 00181 */ 00182 static void 00183 dhcp_handle_nak(struct netif *netif) 00184 { 00185 struct dhcp *dhcp = netif->dhcp; 00186 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_nak(netif=%p) %c%c%"U16_F"\n", 00187 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); 00188 /* Set the interface down since the address must no longer be used, as per RFC2131 */ 00189 netif_set_down(netif); 00190 /* remove IP address from interface */ 00191 netif_set_ipaddr(netif, IP_ADDR_ANY); 00192 netif_set_gw(netif, IP_ADDR_ANY); 00193 netif_set_netmask(netif, IP_ADDR_ANY); 00194 /* Change to a defined state */ 00195 dhcp_set_state(dhcp, DHCP_BACKING_OFF); 00196 /* We can immediately restart discovery */ 00197 dhcp_discover(netif); 00198 } 00199 00200 #if DHCP_DOES_ARP_CHECK 00201 /** 00202 * Checks if the offered IP address is already in use. 00203 * 00204 * It does so by sending an ARP request for the offered address and 00205 * entering CHECKING state. If no ARP reply is received within a small 00206 * interval, the address is assumed to be free for use by us. 00207 * 00208 * @param netif the netif under DHCP control 00209 */ 00210 static void 00211 dhcp_check(struct netif *netif) 00212 { 00213 struct dhcp *dhcp = netif->dhcp; 00214 err_t result; 00215 u16_t msecs; 00216 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_check(netif=%p) %c%c\n", (void *)netif, (s16_t)netif->name[0], 00217 (s16_t)netif->name[1])); 00218 dhcp_set_state(dhcp, DHCP_CHECKING); 00219 /* create an ARP query for the offered IP address, expecting that no host 00220 responds, as the IP address should not be in use. */ 00221 result = etharp_query(netif, &dhcp->offered_ip_addr, NULL); 00222 if (result != ERR_OK) { 00223 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_check: could not perform ARP query\n")); 00224 } 00225 dhcp->tries++; 00226 msecs = 500; 00227 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 00228 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_check(): set request timeout %"U16_F" msecs\n", msecs)); 00229 } 00230 #endif /* DHCP_DOES_ARP_CHECK */ 00231 00232 /** 00233 * Remember the configuration offered by a DHCP server. 00234 * 00235 * @param netif the netif under DHCP control 00236 */ 00237 static void 00238 dhcp_handle_offer(struct netif *netif) 00239 { 00240 struct dhcp *dhcp = netif->dhcp; 00241 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_offer(netif=%p) %c%c%"U16_F"\n", 00242 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); 00243 /* obtain the server address */ 00244 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SERVER_ID)) { 00245 ip4_addr_set_u32(&dhcp->server_ip_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SERVER_ID))); 00246 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): server 0x%08"X32_F"\n", 00247 ip4_addr_get_u32(&dhcp->server_ip_addr))); 00248 /* remember offered address */ 00249 ip_addr_copy(dhcp->offered_ip_addr, dhcp->msg_in->yiaddr); 00250 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): offer for 0x%08"X32_F"\n", 00251 ip4_addr_get_u32(&dhcp->offered_ip_addr))); 00252 00253 dhcp_select(netif); 00254 } else { 00255 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 00256 ("dhcp_handle_offer(netif=%p) did not get server ID!\n", (void*)netif)); 00257 } 00258 } 00259 00260 /** 00261 * Select a DHCP server offer out of all offers. 00262 * 00263 * Simply select the first offer received. 00264 * 00265 * @param netif the netif under DHCP control 00266 * @return lwIP specific error (see error.h) 00267 */ 00268 static err_t 00269 dhcp_select(struct netif *netif) 00270 { 00271 struct dhcp *dhcp = netif->dhcp; 00272 err_t result; 00273 u16_t msecs; 00274 00275 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)); 00276 dhcp_set_state(dhcp, DHCP_REQUESTING); 00277 00278 /* create and initialize the DHCP message header */ 00279 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 00280 if (result == ERR_OK) { 00281 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 00282 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 00283 00284 /* MUST request the offered IP address */ 00285 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 00286 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); 00287 00288 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); 00289 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->server_ip_addr))); 00290 00291 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/); 00292 dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK); 00293 dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER); 00294 dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST); 00295 dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER); 00296 00297 #if LWIP_NETIF_HOSTNAME 00298 if (netif->hostname != NULL) { 00299 const char *p = (const char*)netif->hostname; 00300 u8_t namelen = (u8_t)strlen(p); 00301 if (namelen > 0) { 00302 LWIP_ASSERT("DHCP: hostname is too long!", namelen < 255); 00303 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, namelen); 00304 while (*p) { 00305 dhcp_option_byte(dhcp, *p++); 00306 } 00307 } 00308 } 00309 #endif /* LWIP_NETIF_HOSTNAME */ 00310 00311 dhcp_option_trailer(dhcp); 00312 /* shrink the pbuf to the actual content length */ 00313 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 00314 00315 /* send broadcast to any DHCP server */ 00316 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 00317 dhcp_delete_msg(dhcp); 00318 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_select: REQUESTING\n")); 00319 } else { 00320 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_select: could not allocate DHCP request\n")); 00321 } 00322 dhcp->tries++; 00323 msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000; 00324 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 00325 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_select(): set request timeout %"U16_F" msecs\n", msecs)); 00326 return result; 00327 } 00328 00329 /** 00330 * The DHCP timer that checks for lease renewal/rebind timeouts. 00331 */ 00332 void 00333 dhcp_coarse_tmr() 00334 { 00335 struct netif *netif = netif_list; 00336 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n")); 00337 /* iterate through all network interfaces */ 00338 while (netif != NULL) { 00339 /* only act on DHCP configured interfaces */ 00340 if (netif->dhcp != NULL) { 00341 /* timer is active (non zero), and triggers (zeroes) now? */ 00342 if (netif->dhcp->t2_timeout-- == 1) { 00343 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t2 timeout\n")); 00344 /* this clients' rebind timeout triggered */ 00345 dhcp_t2_timeout(netif); 00346 /* timer is active (non zero), and triggers (zeroes) now */ 00347 } else if (netif->dhcp->t1_timeout-- == 1) { 00348 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t1 timeout\n")); 00349 /* this clients' renewal timeout triggered */ 00350 dhcp_t1_timeout(netif); 00351 } 00352 } 00353 /* proceed to next netif */ 00354 netif = netif->next; 00355 } 00356 } 00357 00358 /** 00359 * DHCP transaction timeout handling 00360 * 00361 * A DHCP server is expected to respond within a short period of time. 00362 * This timer checks whether an outstanding DHCP request is timed out. 00363 */ 00364 void 00365 dhcp_fine_tmr() 00366 { 00367 struct netif *netif = netif_list; 00368 /* loop through netif's */ 00369 while (netif != NULL) { 00370 /* only act on DHCP configured interfaces */ 00371 if (netif->dhcp != NULL) { 00372 /* timer is active (non zero), and is about to trigger now */ 00373 if (netif->dhcp->request_timeout > 1) { 00374 netif->dhcp->request_timeout--; 00375 } 00376 else if (netif->dhcp->request_timeout == 1) { 00377 netif->dhcp->request_timeout--; 00378 /* { netif->dhcp->request_timeout == 0 } */ 00379 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_fine_tmr(): request timeout\n")); 00380 /* this client's request timeout triggered */ 00381 dhcp_timeout(netif); 00382 } 00383 } 00384 /* proceed to next network interface */ 00385 netif = netif->next; 00386 } 00387 } 00388 00389 /** 00390 * A DHCP negotiation transaction, or ARP request, has timed out. 00391 * 00392 * The timer that was started with the DHCP or ARP request has 00393 * timed out, indicating no response was received in time. 00394 * 00395 * @param netif the netif under DHCP control 00396 */ 00397 static void 00398 dhcp_timeout(struct netif *netif) 00399 { 00400 struct dhcp *dhcp = netif->dhcp; 00401 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout()\n")); 00402 /* back-off period has passed, or server selection timed out */ 00403 if ((dhcp->state == DHCP_BACKING_OFF) || (dhcp->state == DHCP_SELECTING)) { 00404 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout(): restarting discovery\n")); 00405 dhcp_discover(netif); 00406 /* receiving the requested lease timed out */ 00407 } else if (dhcp->state == DHCP_REQUESTING) { 00408 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, DHCP request timed out\n")); 00409 if (dhcp->tries <= 5) { 00410 dhcp_select(netif); 00411 } else { 00412 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, releasing, restarting\n")); 00413 dhcp_release(netif); 00414 dhcp_discover(netif); 00415 } 00416 #if DHCP_DOES_ARP_CHECK 00417 /* received no ARP reply for the offered address (which is good) */ 00418 } else if (dhcp->state == DHCP_CHECKING) { 00419 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): CHECKING, ARP request timed out\n")); 00420 if (dhcp->tries <= 1) { 00421 dhcp_check(netif); 00422 /* no ARP replies on the offered address, 00423 looks like the IP address is indeed free */ 00424 } else { 00425 /* bind the interface to the offered address */ 00426 dhcp_bind(netif); 00427 } 00428 #endif /* DHCP_DOES_ARP_CHECK */ 00429 } 00430 /* did not get response to renew request? */ 00431 else if (dhcp->state == DHCP_RENEWING) { 00432 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): RENEWING, DHCP request timed out\n")); 00433 /* just retry renewal */ 00434 /* note that the rebind timer will eventually time-out if renew does not work */ 00435 dhcp_renew(netif); 00436 /* did not get response to rebind request? */ 00437 } else if (dhcp->state == DHCP_REBINDING) { 00438 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REBINDING, DHCP request timed out\n")); 00439 if (dhcp->tries <= 8) { 00440 dhcp_rebind(netif); 00441 } else { 00442 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): RELEASING, DISCOVERING\n")); 00443 dhcp_release(netif); 00444 dhcp_discover(netif); 00445 } 00446 } else if (dhcp->state == DHCP_REBOOTING) { 00447 if (dhcp->tries < REBOOT_TRIES) { 00448 dhcp_reboot(netif); 00449 } else { 00450 dhcp_discover(netif); 00451 } 00452 } 00453 } 00454 00455 /** 00456 * The renewal period has timed out. 00457 * 00458 * @param netif the netif under DHCP control 00459 */ 00460 static void 00461 dhcp_t1_timeout(struct netif *netif) 00462 { 00463 struct dhcp *dhcp = netif->dhcp; 00464 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_t1_timeout()\n")); 00465 if ((dhcp->state == DHCP_REQUESTING) || (dhcp->state == DHCP_BOUND) || 00466 (dhcp->state == DHCP_RENEWING)) { 00467 /* just retry to renew - note that the rebind timer (t2) will 00468 * eventually time-out if renew tries fail. */ 00469 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, 00470 ("dhcp_t1_timeout(): must renew\n")); 00471 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state 00472 DHCP_RENEWING, not DHCP_BOUND */ 00473 dhcp_renew(netif); 00474 } 00475 } 00476 00477 /** 00478 * The rebind period has timed out. 00479 * 00480 * @param netif the netif under DHCP control 00481 */ 00482 static void 00483 dhcp_t2_timeout(struct netif *netif) 00484 { 00485 struct dhcp *dhcp = netif->dhcp; 00486 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t2_timeout()\n")); 00487 if ((dhcp->state == DHCP_REQUESTING) || (dhcp->state == DHCP_BOUND) || 00488 (dhcp->state == DHCP_RENEWING)) { 00489 /* just retry to rebind */ 00490 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, 00491 ("dhcp_t2_timeout(): must rebind\n")); 00492 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state 00493 DHCP_REBINDING, not DHCP_BOUND */ 00494 dhcp_rebind(netif); 00495 } 00496 } 00497 00498 /** 00499 * Handle a DHCP ACK packet 00500 * 00501 * @param netif the netif under DHCP control 00502 */ 00503 static void 00504 dhcp_handle_ack(struct netif *netif) 00505 { 00506 struct dhcp *dhcp = netif->dhcp; 00507 #if LWIP_DNS 00508 u8_t n; 00509 #endif /* LWIP_DNS */ 00510 00511 /* clear options we might not get from the ACK */ 00512 ip_addr_set_zero(&dhcp->offered_sn_mask); 00513 ip_addr_set_zero(&dhcp->offered_gw_addr); 00514 #if LWIP_DHCP_BOOTP_FILE 00515 ip_addr_set_zero(&dhcp->offered_si_addr); 00516 #endif /* LWIP_DHCP_BOOTP_FILE */ 00517 00518 /* lease time given? */ 00519 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_LEASE_TIME)) { 00520 /* remember offered lease time */ 00521 dhcp->offered_t0_lease = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_LEASE_TIME); 00522 } 00523 /* renewal period given? */ 00524 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T1)) { 00525 /* remember given renewal period */ 00526 dhcp->offered_t1_renew = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T1); 00527 } else { 00528 /* calculate safe periods for renewal */ 00529 dhcp->offered_t1_renew = dhcp->offered_t0_lease / 2; 00530 } 00531 00532 /* renewal period given? */ 00533 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T2)) { 00534 /* remember given rebind period */ 00535 dhcp->offered_t2_rebind = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T2); 00536 } else { 00537 /* calculate safe periods for rebinding */ 00538 dhcp->offered_t2_rebind = dhcp->offered_t0_lease; 00539 } 00540 00541 /* (y)our internet address */ 00542 ip_addr_copy(dhcp->offered_ip_addr, dhcp->msg_in->yiaddr); 00543 00544 #if LWIP_DHCP_BOOTP_FILE 00545 /* copy boot server address, 00546 boot file name copied in dhcp_parse_reply if not overloaded */ 00547 ip_addr_copy(dhcp->offered_si_addr, dhcp->msg_in->siaddr); 00548 #endif /* LWIP_DHCP_BOOTP_FILE */ 00549 00550 /* subnet mask given? */ 00551 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)) { 00552 /* remember given subnet mask */ 00553 ip4_addr_set_u32(&dhcp->offered_sn_mask, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SUBNET_MASK))); 00554 dhcp->subnet_mask_given = 1; 00555 } else { 00556 dhcp->subnet_mask_given = 0; 00557 } 00558 00559 /* gateway router */ 00560 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_ROUTER)) { 00561 ip4_addr_set_u32(&dhcp->offered_gw_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_ROUTER))); 00562 } 00563 00564 #if LWIP_DNS 00565 /* DNS servers */ 00566 n = 0; 00567 while((n < DNS_MAX_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n)) { 00568 ip_addr_t dns_addr; 00569 ip4_addr_set_u32(&dns_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n))); 00570 dns_setserver(n, &dns_addr); 00571 n++; 00572 } 00573 #endif /* LWIP_DNS */ 00574 } 00575 00576 /** Set a statically allocated struct dhcp to work with. 00577 * Using this prevents dhcp_start to allocate it using mem_malloc. 00578 * 00579 * @param netif the netif for which to set the struct dhcp 00580 * @param dhcp (uninitialised) dhcp struct allocated by the application 00581 */ 00582 void 00583 dhcp_set_struct(struct netif *netif, struct dhcp *dhcp) 00584 { 00585 LWIP_ASSERT("netif != NULL", netif != NULL); 00586 LWIP_ASSERT("dhcp != NULL", dhcp != NULL); 00587 LWIP_ASSERT("netif already has a struct dhcp set", netif->dhcp == NULL); 00588 00589 /* clear data structure */ 00590 memset(dhcp, 0, sizeof(struct dhcp)); 00591 /* dhcp_set_state(&dhcp, DHCP_OFF); */ 00592 netif->dhcp = dhcp; 00593 } 00594 00595 /** Removes a struct dhcp from a netif. 00596 * 00597 * ATTENTION: Only use this when not using dhcp_set_struct() to allocate the 00598 * struct dhcp since the memory is passed back to the heap. 00599 * 00600 * @param netif the netif from which to remove the struct dhcp 00601 */ 00602 void dhcp_cleanup(struct netif *netif) 00603 { 00604 LWIP_ASSERT("netif != NULL", netif != NULL); 00605 00606 if (netif->dhcp != NULL) { 00607 mem_free(netif->dhcp); 00608 netif->dhcp = NULL; 00609 } 00610 } 00611 00612 /** 00613 * Start DHCP negotiation for a network interface. 00614 * 00615 * If no DHCP client instance was attached to this interface, 00616 * a new client is created first. If a DHCP client instance 00617 * was already present, it restarts negotiation. 00618 * 00619 * @param netif The lwIP network interface 00620 * @return lwIP error code 00621 * - ERR_OK - No error 00622 * - ERR_MEM - Out of memory 00623 */ 00624 err_t 00625 dhcp_start(struct netif *netif) 00626 { 00627 struct dhcp *dhcp; 00628 err_t result = ERR_OK; 00629 00630 LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;); 00631 dhcp = netif->dhcp; 00632 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)); 00633 /* Remove the flag that says this netif is handled by DHCP, 00634 it is set when we succeeded starting. */ 00635 netif->flags &= ~NETIF_FLAG_DHCP; 00636 00637 /* check hwtype of the netif */ 00638 if ((netif->flags & NETIF_FLAG_ETHARP) == 0) { 00639 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): No ETHARP netif\n")); 00640 return ERR_ARG; 00641 } 00642 00643 /* check MTU of the netif */ 00644 if (netif->mtu < DHCP_MAX_MSG_LEN_MIN_REQUIRED) { 00645 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): Cannot use this netif with DHCP: MTU is too small\n")); 00646 return ERR_MEM; 00647 } 00648 00649 /* no DHCP client attached yet? */ 00650 if (dhcp == NULL) { 00651 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting new DHCP client\n")); 00652 dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp)); 00653 if (dhcp == NULL) { 00654 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n")); 00655 return ERR_MEM; 00656 } 00657 /* store this dhcp client in the netif */ 00658 netif->dhcp = dhcp; 00659 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): allocated dhcp")); 00660 /* already has DHCP client attached */ 00661 } else { 00662 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(): restarting DHCP configuration\n")); 00663 if (dhcp->pcb != NULL) { 00664 udp_remove(dhcp->pcb); 00665 } 00666 LWIP_ASSERT("pbuf p_out wasn't freed", dhcp->p_out == NULL); 00667 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL ); 00668 } 00669 00670 /* clear data structure */ 00671 memset(dhcp, 0, sizeof(struct dhcp)); 00672 /* dhcp_set_state(&dhcp, DHCP_OFF); */ 00673 /* allocate UDP PCB */ 00674 dhcp->pcb = udp_new(); 00675 if (dhcp->pcb == NULL) { 00676 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not obtain pcb\n")); 00677 return ERR_MEM; 00678 } 00679 dhcp->pcb->so_options |= SOF_BROADCAST; 00680 /* set up local and remote port for the pcb */ 00681 udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); 00682 udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); 00683 /* set up the recv callback and argument */ 00684 udp_recv(dhcp->pcb, dhcp_recv, netif); 00685 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n")); 00686 /* (re)start the DHCP negotiation */ 00687 result = dhcp_discover(netif); 00688 if (result != ERR_OK) { 00689 /* free resources allocated above */ 00690 dhcp_stop(netif); 00691 return ERR_MEM; 00692 } 00693 /* Set the flag that says this netif is handled by DHCP. */ 00694 netif->flags |= NETIF_FLAG_DHCP; 00695 return result; 00696 } 00697 00698 /** 00699 * Inform a DHCP server of our manual configuration. 00700 * 00701 * This informs DHCP servers of our fixed IP address configuration 00702 * by sending an INFORM message. It does not involve DHCP address 00703 * configuration, it is just here to be nice to the network. 00704 * 00705 * @param netif The lwIP network interface 00706 */ 00707 void 00708 dhcp_inform(struct netif *netif) 00709 { 00710 struct dhcp dhcp; 00711 err_t result = ERR_OK; 00712 struct udp_pcb *pcb; 00713 00714 LWIP_ERROR("netif != NULL", (netif != NULL), return;); 00715 00716 memset(&dhcp, 0, sizeof(struct dhcp)); 00717 dhcp_set_state(&dhcp, DHCP_INFORM); 00718 00719 if ((netif->dhcp != NULL) && (netif->dhcp->pcb != NULL)) { 00720 /* re-use existing pcb */ 00721 pcb = netif->dhcp->pcb; 00722 } else { 00723 pcb = udp_new(); 00724 if (pcb == NULL) { 00725 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform(): could not obtain pcb")); 00726 return; 00727 } 00728 dhcp.pcb = pcb; 00729 dhcp.pcb->so_options |= SOF_BROADCAST; 00730 udp_bind(dhcp.pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); 00731 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_inform(): created new udp pcb\n")); 00732 } 00733 /* create and initialize the DHCP message header */ 00734 result = dhcp_create_msg(netif, &dhcp, DHCP_INFORM); 00735 if (result == ERR_OK) { 00736 dhcp_option(&dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 00737 dhcp_option_short(&dhcp, DHCP_MAX_MSG_LEN(netif)); 00738 00739 dhcp_option_trailer(&dhcp); 00740 00741 pbuf_realloc(dhcp.p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp.options_out_len); 00742 00743 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n")); 00744 udp_sendto_if(pcb, dhcp.p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 00745 dhcp_delete_msg(&dhcp); 00746 } else { 00747 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform: could not allocate DHCP request\n")); 00748 } 00749 00750 if (dhcp.pcb != NULL) { 00751 /* otherwise, the existing pcb was used */ 00752 udp_remove(dhcp.pcb); 00753 } 00754 } 00755 00756 /** Handle a possible change in the network configuration. 00757 * 00758 * This enters the REBOOTING state to verify that the currently bound 00759 * address is still valid. 00760 */ 00761 void 00762 dhcp_network_changed(struct netif *netif) 00763 { 00764 struct dhcp *dhcp = netif->dhcp; 00765 if (!dhcp) 00766 return; 00767 switch (dhcp->state) { 00768 case DHCP_REBINDING: 00769 case DHCP_RENEWING: 00770 case DHCP_BOUND: 00771 case DHCP_REBOOTING: 00772 netif_set_down(netif); 00773 dhcp->tries = 0; 00774 dhcp_reboot(netif); 00775 break; 00776 case DHCP_OFF: 00777 /* stay off */ 00778 break; 00779 default: 00780 dhcp->tries = 0; 00781 #if LWIP_DHCP_AUTOIP_COOP 00782 if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { 00783 autoip_stop(netif); 00784 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; 00785 } 00786 #endif /* LWIP_DHCP_AUTOIP_COOP */ 00787 dhcp_discover(netif); 00788 break; 00789 } 00790 } 00791 00792 #if DHCP_DOES_ARP_CHECK 00793 /** 00794 * Match an ARP reply with the offered IP address. 00795 * 00796 * @param netif the network interface on which the reply was received 00797 * @param addr The IP address we received a reply from 00798 */ 00799 void dhcp_arp_reply(struct netif *netif, ip_addr_t *addr) 00800 { 00801 LWIP_ERROR("netif != NULL", (netif != NULL), return;); 00802 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_arp_reply()\n")); 00803 /* is a DHCP client doing an ARP check? */ 00804 if ((netif->dhcp != NULL) && (netif->dhcp->state == DHCP_CHECKING)) { 00805 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_arp_reply(): CHECKING, arp reply for 0x%08"X32_F"\n", 00806 ip4_addr_get_u32(addr))); 00807 /* did a host respond with the address we 00808 were offered by the DHCP server? */ 00809 if (ip_addr_cmp(addr, &netif->dhcp->offered_ip_addr)) { 00810 /* we will not accept the offered address */ 00811 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING, 00812 ("dhcp_arp_reply(): arp reply matched with offered address, declining\n")); 00813 dhcp_decline(netif); 00814 } 00815 } 00816 } 00817 00818 /** 00819 * Decline an offered lease. 00820 * 00821 * Tell the DHCP server we do not accept the offered address. 00822 * One reason to decline the lease is when we find out the address 00823 * is already in use by another host (through ARP). 00824 * 00825 * @param netif the netif under DHCP control 00826 */ 00827 static err_t 00828 dhcp_decline(struct netif *netif) 00829 { 00830 struct dhcp *dhcp = netif->dhcp; 00831 err_t result = ERR_OK; 00832 u16_t msecs; 00833 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline()\n")); 00834 dhcp_set_state(dhcp, DHCP_BACKING_OFF); 00835 /* create and initialize the DHCP message header */ 00836 result = dhcp_create_msg(netif, dhcp, DHCP_DECLINE); 00837 if (result == ERR_OK) { 00838 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 00839 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); 00840 00841 dhcp_option_trailer(dhcp); 00842 /* resize pbuf to reflect true size of options */ 00843 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 00844 00845 /* per section 4.4.4, broadcast DECLINE messages */ 00846 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 00847 dhcp_delete_msg(dhcp); 00848 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_decline: BACKING OFF\n")); 00849 } else { 00850 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 00851 ("dhcp_decline: could not allocate DHCP request\n")); 00852 } 00853 dhcp->tries++; 00854 msecs = 10*1000; 00855 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 00856 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs)); 00857 return result; 00858 } 00859 #endif /* DHCP_DOES_ARP_CHECK */ 00860 00861 00862 /** 00863 * Start the DHCP process, discover a DHCP server. 00864 * 00865 * @param netif the netif under DHCP control 00866 */ 00867 static err_t 00868 dhcp_discover(struct netif *netif) 00869 { 00870 struct dhcp *dhcp = netif->dhcp; 00871 err_t result = ERR_OK; 00872 u16_t msecs; 00873 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover()\n")); 00874 ip_addr_set_any(&dhcp->offered_ip_addr); 00875 dhcp_set_state(dhcp, DHCP_SELECTING); 00876 /* create and initialize the DHCP message header */ 00877 result = dhcp_create_msg(netif, dhcp, DHCP_DISCOVER); 00878 if (result == ERR_OK) { 00879 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n")); 00880 00881 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 00882 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 00883 00884 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/); 00885 dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK); 00886 dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER); 00887 dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST); 00888 dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER); 00889 00890 dhcp_option_trailer(dhcp); 00891 00892 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: realloc()ing\n")); 00893 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 00894 00895 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, DHCP_SERVER_PORT)\n")); 00896 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 00897 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()ing\n")); 00898 dhcp_delete_msg(dhcp); 00899 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover: SELECTING\n")); 00900 } else { 00901 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_discover: could not allocate DHCP request\n")); 00902 } 00903 dhcp->tries++; 00904 #if LWIP_DHCP_AUTOIP_COOP 00905 if(dhcp->tries >= LWIP_DHCP_AUTOIP_COOP_TRIES && dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_OFF) { 00906 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_ON; 00907 autoip_start(netif); 00908 } 00909 #endif /* LWIP_DHCP_AUTOIP_COOP */ 00910 msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000; 00911 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 00912 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs)); 00913 return result; 00914 } 00915 00916 00917 /** 00918 * Bind the interface to the offered IP address. 00919 * 00920 * @param netif network interface to bind to the offered address 00921 */ 00922 static void 00923 dhcp_bind(struct netif *netif) 00924 { 00925 u32_t timeout; 00926 struct dhcp *dhcp; 00927 ip_addr_t sn_mask, gw_addr; 00928 LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;); 00929 dhcp = netif->dhcp; 00930 LWIP_ERROR("dhcp_bind: dhcp != NULL", (dhcp != NULL), return;); 00931 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)); 00932 00933 /* temporary DHCP lease? */ 00934 if (dhcp->offered_t1_renew != 0xffffffffUL) { 00935 /* set renewal period timer */ 00936 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew)); 00937 timeout = (dhcp->offered_t1_renew + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; 00938 if(timeout > 0xffff) { 00939 timeout = 0xffff; 00940 } 00941 dhcp->t1_timeout = (u16_t)timeout; 00942 if (dhcp->t1_timeout == 0) { 00943 dhcp->t1_timeout = 1; 00944 } 00945 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew*1000)); 00946 } 00947 /* set renewal period timer */ 00948 if (dhcp->offered_t2_rebind != 0xffffffffUL) { 00949 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind)); 00950 timeout = (dhcp->offered_t2_rebind + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; 00951 if(timeout > 0xffff) { 00952 timeout = 0xffff; 00953 } 00954 dhcp->t2_timeout = (u16_t)timeout; 00955 if (dhcp->t2_timeout == 0) { 00956 dhcp->t2_timeout = 1; 00957 } 00958 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t2_rebind*1000)); 00959 } 00960 00961 if (dhcp->subnet_mask_given) { 00962 /* copy offered network mask */ 00963 ip_addr_copy(sn_mask, dhcp->offered_sn_mask); 00964 } else { 00965 /* subnet mask not given, choose a safe subnet mask given the network class */ 00966 u8_t first_octet = ip4_addr1(&dhcp->offered_ip_addr); 00967 if (first_octet <= 127) { 00968 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xff000000UL)); 00969 } else if (first_octet >= 192) { 00970 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffffff00UL)); 00971 } else { 00972 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffff0000UL)); 00973 } 00974 } 00975 00976 ip_addr_copy(gw_addr, dhcp->offered_gw_addr); 00977 /* gateway address not given? */ 00978 if (gw_addr.addr == IPADDR_ANY) { 00979 /* copy network address */ 00980 ip_addr_get_network(&gw_addr, &dhcp->offered_ip_addr, &sn_mask); 00981 /* use first host address on network as gateway */ 00982 ip4_addr_set_u32(&gw_addr, ip4_addr_get_u32(&gw_addr) | PP_HTONL(0x00000001UL)); 00983 } 00984 00985 #if LWIP_DHCP_AUTOIP_COOP 00986 if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { 00987 autoip_stop(netif); 00988 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; 00989 } 00990 #endif /* LWIP_DHCP_AUTOIP_COOP */ 00991 00992 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): IP: 0x%08"X32_F"\n", 00993 ip4_addr_get_u32(&dhcp->offered_ip_addr))); 00994 netif_set_ipaddr(netif, &dhcp->offered_ip_addr); 00995 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): SN: 0x%08"X32_F"\n", 00996 ip4_addr_get_u32(&sn_mask))); 00997 netif_set_netmask(netif, &sn_mask); 00998 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): GW: 0x%08"X32_F"\n", 00999 ip4_addr_get_u32(&gw_addr))); 01000 netif_set_gw(netif, &gw_addr); 01001 /* bring the interface up */ 01002 netif_set_up(netif); 01003 /* netif is now bound to DHCP leased address */ 01004 dhcp_set_state(dhcp, DHCP_BOUND); 01005 } 01006 01007 /** 01008 * Renew an existing DHCP lease at the involved DHCP server. 01009 * 01010 * @param netif network interface which must renew its lease 01011 */ 01012 err_t 01013 dhcp_renew(struct netif *netif) 01014 { 01015 struct dhcp *dhcp = netif->dhcp; 01016 err_t result; 01017 u16_t msecs; 01018 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_renew()\n")); 01019 dhcp_set_state(dhcp, DHCP_RENEWING); 01020 01021 /* create and initialize the DHCP message header */ 01022 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 01023 if (result == ERR_OK) { 01024 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 01025 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 01026 01027 #if LWIP_NETIF_HOSTNAME 01028 if (netif->hostname != NULL) { 01029 const char *p = (const char*)netif->hostname; 01030 u8_t namelen = (u8_t)strlen(p); 01031 if (namelen > 0) { 01032 LWIP_ASSERT("DHCP: hostname is too long!", namelen < 255); 01033 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, namelen); 01034 while (*p) { 01035 dhcp_option_byte(dhcp, *p++); 01036 } 01037 } 01038 } 01039 #endif /* LWIP_NETIF_HOSTNAME */ 01040 01041 #if 0 01042 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 01043 dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); 01044 #endif 01045 01046 #if 0 01047 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); 01048 dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr)); 01049 #endif 01050 /* append DHCP message trailer */ 01051 dhcp_option_trailer(dhcp); 01052 01053 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 01054 01055 udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif); 01056 dhcp_delete_msg(dhcp); 01057 01058 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew: RENEWING\n")); 01059 } else { 01060 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_renew: could not allocate DHCP request\n")); 01061 } 01062 dhcp->tries++; 01063 /* back-off on retries, but to a maximum of 20 seconds */ 01064 msecs = dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000; 01065 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 01066 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs)); 01067 return result; 01068 } 01069 01070 /** 01071 * Rebind with a DHCP server for an existing DHCP lease. 01072 * 01073 * @param netif network interface which must rebind with a DHCP server 01074 */ 01075 static err_t 01076 dhcp_rebind(struct netif *netif) 01077 { 01078 struct dhcp *dhcp = netif->dhcp; 01079 err_t result; 01080 u16_t msecs; 01081 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n")); 01082 dhcp_set_state(dhcp, DHCP_REBINDING); 01083 01084 /* create and initialize the DHCP message header */ 01085 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 01086 if (result == ERR_OK) { 01087 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 01088 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 01089 01090 #if LWIP_NETIF_HOSTNAME 01091 if (netif->hostname != NULL) { 01092 const char *p = (const char*)netif->hostname; 01093 u8_t namelen = (u8_t)strlen(p); 01094 if (namelen > 0) { 01095 LWIP_ASSERT("DHCP: hostname is too long!", namelen < 255); 01096 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, namelen); 01097 while (*p) { 01098 dhcp_option_byte(dhcp, *p++); 01099 } 01100 } 01101 } 01102 #endif /* LWIP_NETIF_HOSTNAME */ 01103 01104 #if 0 01105 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 01106 dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); 01107 01108 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); 01109 dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr)); 01110 #endif 01111 01112 dhcp_option_trailer(dhcp); 01113 01114 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 01115 01116 /* broadcast to server */ 01117 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 01118 dhcp_delete_msg(dhcp); 01119 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n")); 01120 } else { 01121 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_rebind: could not allocate DHCP request\n")); 01122 } 01123 dhcp->tries++; 01124 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; 01125 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 01126 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs)); 01127 return result; 01128 } 01129 01130 /** 01131 * Enter REBOOTING state to verify an existing lease 01132 * 01133 * @param netif network interface which must reboot 01134 */ 01135 static err_t 01136 dhcp_reboot(struct netif *netif) 01137 { 01138 struct dhcp *dhcp = netif->dhcp; 01139 err_t result; 01140 u16_t msecs; 01141 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n")); 01142 dhcp_set_state(dhcp, DHCP_REBOOTING); 01143 01144 /* create and initialize the DHCP message header */ 01145 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 01146 if (result == ERR_OK) { 01147 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 01148 dhcp_option_short(dhcp, 576); 01149 01150 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 01151 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); 01152 01153 dhcp_option_trailer(dhcp); 01154 01155 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 01156 01157 /* broadcast to server */ 01158 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 01159 dhcp_delete_msg(dhcp); 01160 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot: REBOOTING\n")); 01161 } else { 01162 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_reboot: could not allocate DHCP request\n")); 01163 } 01164 dhcp->tries++; 01165 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; 01166 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 01167 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot(): set request timeout %"U16_F" msecs\n", msecs)); 01168 return result; 01169 } 01170 01171 01172 /** 01173 * Release a DHCP lease. 01174 * 01175 * @param netif network interface which must release its lease 01176 */ 01177 err_t 01178 dhcp_release(struct netif *netif) 01179 { 01180 struct dhcp *dhcp = netif->dhcp; 01181 err_t result; 01182 u16_t msecs; 01183 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release()\n")); 01184 01185 /* idle DHCP client */ 01186 dhcp_set_state(dhcp, DHCP_OFF); 01187 /* clean old DHCP offer */ 01188 ip_addr_set_zero(&dhcp->server_ip_addr); 01189 ip_addr_set_zero(&dhcp->offered_ip_addr); 01190 ip_addr_set_zero(&dhcp->offered_sn_mask); 01191 ip_addr_set_zero(&dhcp->offered_gw_addr); 01192 #if LWIP_DHCP_BOOTP_FILE 01193 ip_addr_set_zero(&dhcp->offered_si_addr); 01194 #endif /* LWIP_DHCP_BOOTP_FILE */ 01195 dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0; 01196 01197 /* create and initialize the DHCP message header */ 01198 result = dhcp_create_msg(netif, dhcp, DHCP_RELEASE); 01199 if (result == ERR_OK) { 01200 dhcp_option_trailer(dhcp); 01201 01202 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 01203 01204 udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif); 01205 dhcp_delete_msg(dhcp); 01206 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_OFF\n")); 01207 } else { 01208 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n")); 01209 } 01210 dhcp->tries++; 01211 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; 01212 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 01213 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release(): set request timeout %"U16_F" msecs\n", msecs)); 01214 /* bring the interface down */ 01215 netif_set_down(netif); 01216 /* remove IP address from interface */ 01217 netif_set_ipaddr(netif, IP_ADDR_ANY); 01218 netif_set_gw(netif, IP_ADDR_ANY); 01219 netif_set_netmask(netif, IP_ADDR_ANY); 01220 01221 return result; 01222 } 01223 01224 /** 01225 * Remove the DHCP client from the interface. 01226 * 01227 * @param netif The network interface to stop DHCP on 01228 */ 01229 void 01230 dhcp_stop(struct netif *netif) 01231 { 01232 struct dhcp *dhcp; 01233 LWIP_ERROR("dhcp_stop: netif != NULL", (netif != NULL), return;); 01234 dhcp = netif->dhcp; 01235 /* Remove the flag that says this netif is handled by DHCP. */ 01236 netif->flags &= ~NETIF_FLAG_DHCP; 01237 01238 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_stop()\n")); 01239 /* netif is DHCP configured? */ 01240 if (dhcp != NULL) { 01241 #if LWIP_DHCP_AUTOIP_COOP 01242 if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { 01243 autoip_stop(netif); 01244 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; 01245 } 01246 #endif /* LWIP_DHCP_AUTOIP_COOP */ 01247 01248 if (dhcp->pcb != NULL) { 01249 udp_remove(dhcp->pcb); 01250 dhcp->pcb = NULL; 01251 } 01252 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL); 01253 dhcp_set_state(dhcp, DHCP_OFF); 01254 } 01255 } 01256 01257 /* 01258 * Set the DHCP state of a DHCP client. 01259 * 01260 * If the state changed, reset the number of tries. 01261 */ 01262 static void 01263 dhcp_set_state(struct dhcp *dhcp, u8_t new_state) 01264 { 01265 if (new_state != dhcp->state) { 01266 dhcp->state = new_state; 01267 dhcp->tries = 0; 01268 dhcp->request_timeout = 0; 01269 } 01270 } 01271 01272 /* 01273 * Concatenate an option type and length field to the outgoing 01274 * DHCP message. 01275 * 01276 */ 01277 static void 01278 dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len) 01279 { 01280 LWIP_ASSERT("dhcp_option: dhcp->options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN); 01281 dhcp->msg_out->options[dhcp->options_out_len++] = option_type; 01282 dhcp->msg_out->options[dhcp->options_out_len++] = option_len; 01283 } 01284 /* 01285 * Concatenate a single byte to the outgoing DHCP message. 01286 * 01287 */ 01288 static void 01289 dhcp_option_byte(struct dhcp *dhcp, u8_t value) 01290 { 01291 LWIP_ASSERT("dhcp_option_byte: dhcp->options_out_len < DHCP_OPTIONS_LEN", dhcp->options_out_len < DHCP_OPTIONS_LEN); 01292 dhcp->msg_out->options[dhcp->options_out_len++] = value; 01293 } 01294 01295 static void 01296 dhcp_option_short(struct dhcp *dhcp, u16_t value) 01297 { 01298 LWIP_ASSERT("dhcp_option_short: dhcp->options_out_len + 2 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U <= DHCP_OPTIONS_LEN); 01299 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff00U) >> 8); 01300 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t) (value & 0x00ffU); 01301 } 01302 01303 static void 01304 dhcp_option_long(struct dhcp *dhcp, u32_t value) 01305 { 01306 LWIP_ASSERT("dhcp_option_long: dhcp->options_out_len + 4 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 4U <= DHCP_OPTIONS_LEN); 01307 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24); 01308 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16); 01309 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8); 01310 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x000000ffUL)); 01311 } 01312 01313 /** 01314 * Extract the DHCP message and the DHCP options. 01315 * 01316 * Extract the DHCP message and the DHCP options, each into a contiguous 01317 * piece of memory. As a DHCP message is variable sized by its options, 01318 * and also allows overriding some fields for options, the easy approach 01319 * is to first unfold the options into a conitguous piece of memory, and 01320 * use that further on. 01321 * 01322 */ 01323 static err_t 01324 dhcp_parse_reply(struct dhcp *dhcp, struct pbuf *p) 01325 { 01326 u8_t *options; 01327 u16_t offset; 01328 u16_t offset_max; 01329 u16_t options_idx; 01330 u16_t options_idx_max; 01331 struct pbuf *q; 01332 int parse_file_as_options = 0; 01333 int parse_sname_as_options = 0; 01334 01335 /* clear received options */ 01336 dhcp_clear_all_options(dhcp); 01337 /* check that beginning of dhcp_msg (up to and including chaddr) is in first pbuf */ 01338 if (p->len < DHCP_SNAME_OFS) { 01339 return ERR_BUF; 01340 } 01341 dhcp->msg_in = (struct dhcp_msg *)p->payload; 01342 #if LWIP_DHCP_BOOTP_FILE 01343 /* clear boot file name */ 01344 dhcp->boot_file_name[0] = 0; 01345 #endif /* LWIP_DHCP_BOOTP_FILE */ 01346 01347 /* parse options */ 01348 01349 /* start with options field */ 01350 options_idx = DHCP_OPTIONS_OFS; 01351 /* parse options to the end of the received packet */ 01352 options_idx_max = p->tot_len; 01353 again: 01354 q = p; 01355 while((q != NULL) && (options_idx >= q->len)) { 01356 options_idx -= q->len; 01357 options_idx_max -= q->len; 01358 q = q->next; 01359 } 01360 if (q == NULL) { 01361 return ERR_BUF; 01362 } 01363 offset = options_idx; 01364 offset_max = options_idx_max; 01365 options = (u8_t*)q->payload; 01366 /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */ 01367 while((q != NULL) && (options[offset] != DHCP_OPTION_END) && (offset < offset_max)) { 01368 u8_t op = options[offset]; 01369 u8_t len; 01370 u8_t decode_len = 0; 01371 int decode_idx = -1; 01372 u16_t val_offset = offset + 2; 01373 /* len byte might be in the next pbuf */ 01374 if (offset + 1 < q->len) { 01375 len = options[offset + 1]; 01376 } else { 01377 len = (q->next != NULL ? ((u8_t*)q->next->payload)[0] : 0); 01378 } 01379 /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F, msg_offset, q->len)); */ 01380 decode_len = len; 01381 switch(op) { 01382 /* case(DHCP_OPTION_END): handled above */ 01383 case(DHCP_OPTION_PAD): 01384 /* special option: no len encoded */ 01385 decode_len = len = 0; 01386 /* will be increased below */ 01387 offset--; 01388 break; 01389 case(DHCP_OPTION_SUBNET_MASK): 01390 LWIP_ASSERT("len == 4", len == 4); 01391 decode_idx = DHCP_OPTION_IDX_SUBNET_MASK; 01392 break; 01393 case(DHCP_OPTION_ROUTER): 01394 decode_len = 4; /* only copy the first given router */ 01395 LWIP_ASSERT("len >= decode_len", len >= decode_len); 01396 decode_idx = DHCP_OPTION_IDX_ROUTER; 01397 break; 01398 case(DHCP_OPTION_DNS_SERVER): 01399 /* special case: there might be more than one server */ 01400 LWIP_ASSERT("len % 4 == 0", len % 4 == 0); 01401 /* limit number of DNS servers */ 01402 decode_len = LWIP_MIN(len, 4 * DNS_MAX_SERVERS); 01403 LWIP_ASSERT("len >= decode_len", len >= decode_len); 01404 decode_idx = DHCP_OPTION_IDX_DNS_SERVER; 01405 break; 01406 case(DHCP_OPTION_LEASE_TIME): 01407 LWIP_ASSERT("len == 4", len == 4); 01408 decode_idx = DHCP_OPTION_IDX_LEASE_TIME; 01409 break; 01410 case(DHCP_OPTION_OVERLOAD): 01411 LWIP_ASSERT("len == 1", len == 1); 01412 decode_idx = DHCP_OPTION_IDX_OVERLOAD; 01413 break; 01414 case(DHCP_OPTION_MESSAGE_TYPE): 01415 LWIP_ASSERT("len == 1", len == 1); 01416 decode_idx = DHCP_OPTION_IDX_MSG_TYPE; 01417 break; 01418 case(DHCP_OPTION_SERVER_ID): 01419 LWIP_ASSERT("len == 4", len == 4); 01420 decode_idx = DHCP_OPTION_IDX_SERVER_ID; 01421 break; 01422 case(DHCP_OPTION_T1): 01423 LWIP_ASSERT("len == 4", len == 4); 01424 decode_idx = DHCP_OPTION_IDX_T1; 01425 break; 01426 case(DHCP_OPTION_T2): 01427 LWIP_ASSERT("len == 4", len == 4); 01428 decode_idx = DHCP_OPTION_IDX_T2; 01429 break; 01430 default: 01431 decode_len = 0; 01432 LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", op)); 01433 break; 01434 } 01435 offset += len + 2; 01436 if (decode_len > 0) { 01437 u32_t value = 0; 01438 u16_t copy_len; 01439 decode_next: 01440 LWIP_ASSERT("check decode_idx", decode_idx >= 0 && decode_idx < DHCP_OPTION_IDX_MAX); 01441 LWIP_ASSERT("option already decoded", !dhcp_option_given(dhcp, decode_idx)); 01442 copy_len = LWIP_MIN(decode_len, 4); 01443 pbuf_copy_partial(q, &value, copy_len, val_offset); 01444 if (decode_len > 4) { 01445 /* decode more than one u32_t */ 01446 LWIP_ASSERT("decode_len % 4 == 0", decode_len % 4 == 0); 01447 dhcp_got_option(dhcp, decode_idx); 01448 dhcp_set_option_value(dhcp, decode_idx, htonl(value)); 01449 decode_len -= 4; 01450 val_offset += 4; 01451 decode_idx++; 01452 goto decode_next; 01453 } else if (decode_len == 4) { 01454 value = ntohl(value); 01455 } else { 01456 LWIP_ASSERT("invalid decode_len", decode_len == 1); 01457 value = ((u8_t*)&value)[0]; 01458 } 01459 dhcp_got_option(dhcp, decode_idx); 01460 dhcp_set_option_value(dhcp, decode_idx, value); 01461 } 01462 if (offset >= q->len) { 01463 offset -= q->len; 01464 offset_max -= q->len; 01465 q = q->next; 01466 options = (u8_t*)q->payload; 01467 } 01468 } 01469 /* is this an overloaded message? */ 01470 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_OVERLOAD)) { 01471 u32_t overload = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_OVERLOAD); 01472 dhcp_clear_option(dhcp, DHCP_OPTION_IDX_OVERLOAD); 01473 if (overload == DHCP_OVERLOAD_FILE) { 01474 parse_file_as_options = 1; 01475 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded file field\n")); 01476 } else if (overload == DHCP_OVERLOAD_SNAME) { 01477 parse_sname_as_options = 1; 01478 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname field\n")); 01479 } else if (overload == DHCP_OVERLOAD_SNAME_FILE) { 01480 parse_sname_as_options = 1; 01481 parse_file_as_options = 1; 01482 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname and file field\n")); 01483 } else { 01484 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("invalid overload option: %d\n", (int)overload)); 01485 } 01486 #if LWIP_DHCP_BOOTP_FILE 01487 if (!parse_file_as_options) { 01488 /* only do this for ACK messages */ 01489 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) && 01490 (dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK)) 01491 /* copy bootp file name, don't care for sname (server hostname) */ 01492 pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS); 01493 /* make sure the string is really NULL-terminated */ 01494 dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0; 01495 } 01496 #endif /* LWIP_DHCP_BOOTP_FILE */ 01497 } 01498 if (parse_file_as_options) { 01499 /* if both are overloaded, parse file first and then sname (RFC 2131 ch. 4.1) */ 01500 parse_file_as_options = 0; 01501 options_idx = DHCP_FILE_OFS; 01502 options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN; 01503 goto again; 01504 } else if (parse_sname_as_options) { 01505 parse_sname_as_options = 0; 01506 options_idx = DHCP_SNAME_OFS; 01507 options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN; 01508 goto again; 01509 } 01510 return ERR_OK; 01511 } 01512 01513 /** 01514 * If an incoming DHCP message is in response to us, then trigger the state machine 01515 */ 01516 static void 01517 dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port) 01518 { 01519 struct netif *netif = (struct netif *)arg; 01520 struct dhcp *dhcp = netif->dhcp; 01521 struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload; 01522 u8_t msg_type; 01523 u8_t i; 01524 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, 01525 ip4_addr1_16(addr), ip4_addr2_16(addr), ip4_addr3_16(addr), ip4_addr4_16(addr), port)); 01526 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len)); 01527 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len)); 01528 /* prevent warnings about unused arguments */ 01529 LWIP_UNUSED_ARG(pcb); 01530 LWIP_UNUSED_ARG(addr); 01531 LWIP_UNUSED_ARG(port); 01532 01533 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL); 01534 01535 if (p->len < DHCP_MIN_REPLY_LEN) { 01536 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP reply message or pbuf too short\n")); 01537 goto free_pbuf_and_return; 01538 } 01539 01540 if (reply_msg->op != DHCP_BOOTREPLY) { 01541 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)); 01542 goto free_pbuf_and_return; 01543 } 01544 /* iterate through hardware address and match against DHCP message */ 01545 for (i = 0; i < netif->hwaddr_len; i++) { 01546 if (netif->hwaddr[i] != reply_msg->chaddr[i]) { 01547 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, 01548 ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n", 01549 (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i])); 01550 goto free_pbuf_and_return; 01551 } 01552 } 01553 /* match transaction ID against what we expected */ 01554 if (ntohl(reply_msg->xid) != dhcp->xid) { 01555 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, 01556 ("transaction id mismatch reply_msg->xid(%"X32_F")!=dhcp->xid(%"X32_F")\n",ntohl(reply_msg->xid),dhcp->xid)); 01557 goto free_pbuf_and_return; 01558 } 01559 /* option fields could be unfold? */ 01560 if (dhcp_parse_reply(dhcp, p) != ERR_OK) { 01561 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 01562 ("problem unfolding DHCP message - too short on memory?\n")); 01563 goto free_pbuf_and_return; 01564 } 01565 01566 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n")); 01567 /* obtain pointer to DHCP message type */ 01568 if (!dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE)) { 01569 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP_OPTION_MESSAGE_TYPE option not found\n")); 01570 goto free_pbuf_and_return; 01571 } 01572 01573 /* read DHCP message type */ 01574 msg_type = (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE); 01575 /* message type is DHCP ACK? */ 01576 if (msg_type == DHCP_ACK) { 01577 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_ACK received\n")); 01578 /* in requesting state? */ 01579 if (dhcp->state == DHCP_REQUESTING) { 01580 dhcp_handle_ack(netif); 01581 #if DHCP_DOES_ARP_CHECK 01582 /* check if the acknowledged lease address is already in use */ 01583 dhcp_check(netif); 01584 #else 01585 /* bind interface to the acknowledged lease address */ 01586 dhcp_bind(netif); 01587 #endif 01588 } 01589 /* already bound to the given lease address? */ 01590 else if ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING)) { 01591 dhcp_bind(netif); 01592 } 01593 } 01594 /* received a DHCP_NAK in appropriate state? */ 01595 else if ((msg_type == DHCP_NAK) && 01596 ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REQUESTING) || 01597 (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING ))) { 01598 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_NAK received\n")); 01599 dhcp_handle_nak(netif); 01600 } 01601 /* received a DHCP_OFFER in DHCP_SELECTING state? */ 01602 else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_SELECTING)) { 01603 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_OFFER received in DHCP_SELECTING state\n")); 01604 dhcp->request_timeout = 0; 01605 /* remember offered lease */ 01606 dhcp_handle_offer(netif); 01607 } 01608 free_pbuf_and_return: 01609 dhcp->msg_in = NULL; 01610 pbuf_free(p); 01611 } 01612 01613 /** 01614 * Create a DHCP request, fill in common headers 01615 * 01616 * @param netif the netif under DHCP control 01617 * @param dhcp dhcp control struct 01618 * @param message_type message type of the request 01619 */ 01620 static err_t 01621 dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type) 01622 { 01623 u16_t i; 01624 #ifndef DHCP_GLOBAL_XID 01625 /** default global transaction identifier starting value (easy to match 01626 * with a packet analyser). We simply increment for each new request. 01627 * Predefine DHCP_GLOBAL_XID to a better value or a function call to generate one 01628 * at runtime, any supporting function prototypes can be defined in DHCP_GLOBAL_XID_HEADER */ 01629 static u32_t xid = 0xABCD0000; 01630 #else 01631 static u32_t xid; 01632 static u8_t xid_initialised = 0; 01633 if (!xid_initialised) { 01634 xid = DHCP_GLOBAL_XID; 01635 xid_initialised = !xid_initialised; 01636 } 01637 #endif 01638 LWIP_ERROR("dhcp_create_msg: netif != NULL", (netif != NULL), return ERR_ARG;); 01639 LWIP_ERROR("dhcp_create_msg: dhcp != NULL", (dhcp != NULL), return ERR_VAL;); 01640 LWIP_ASSERT("dhcp_create_msg: dhcp->p_out == NULL", dhcp->p_out == NULL); 01641 LWIP_ASSERT("dhcp_create_msg: dhcp->msg_out == NULL", dhcp->msg_out == NULL); 01642 dhcp->p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM); 01643 if (dhcp->p_out == NULL) { 01644 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 01645 ("dhcp_create_msg(): could not allocate pbuf\n")); 01646 return ERR_MEM; 01647 } 01648 LWIP_ASSERT("dhcp_create_msg: check that first pbuf can hold struct dhcp_msg", 01649 (dhcp->p_out->len >= sizeof(struct dhcp_msg))); 01650 01651 /* reuse transaction identifier in retransmissions */ 01652 if (dhcp->tries == 0) { 01653 xid++; 01654 } 01655 dhcp->xid = xid; 01656 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, 01657 ("transaction id xid(%"X32_F")\n", xid)); 01658 01659 dhcp->msg_out = (struct dhcp_msg *)dhcp->p_out->payload; 01660 01661 dhcp->msg_out->op = DHCP_BOOTREQUEST; 01662 /* TODO: make link layer independent */ 01663 dhcp->msg_out->htype = DHCP_HTYPE_ETH; 01664 dhcp->msg_out->hlen = netif->hwaddr_len; 01665 dhcp->msg_out->hops = 0; 01666 dhcp->msg_out->xid = htonl(dhcp->xid); 01667 dhcp->msg_out->secs = 0; 01668 /* we don't need the broadcast flag since we can receive unicast traffic 01669 before being fully configured! */ 01670 dhcp->msg_out->flags = 0; 01671 ip_addr_set_zero(&dhcp->msg_out->ciaddr); 01672 /* set ciaddr to netif->ip_addr based on message_type and state */ 01673 if ((message_type == DHCP_INFORM) || (message_type == DHCP_DECLINE) || 01674 ((message_type == DHCP_REQUEST) && /* DHCP_BOUND not used for sending! */ 01675 ((dhcp->state==DHCP_RENEWING) || dhcp->state==DHCP_REBINDING))) { 01676 ip_addr_copy(dhcp->msg_out->ciaddr, netif->ip_addr); 01677 } 01678 ip_addr_set_zero(&dhcp->msg_out->yiaddr); 01679 ip_addr_set_zero(&dhcp->msg_out->siaddr); 01680 ip_addr_set_zero(&dhcp->msg_out->giaddr); 01681 for (i = 0; i < netif->hwaddr_len; i++) { 01682 /* copy netif hardware address */ 01683 dhcp->msg_out->chaddr[i] = netif->hwaddr[i]; 01684 } 01685 for ( ; i < DHCP_CHADDR_LEN; i++) { 01686 /* ... pad rest with zeroes */ 01687 dhcp->msg_out->chaddr[i] = 0; 01688 } 01689 for (i = 0; i < DHCP_SNAME_LEN; i++) { 01690 dhcp->msg_out->sname[i] = 0; 01691 } 01692 for (i = 0; i < DHCP_FILE_LEN; i++) { 01693 dhcp->msg_out->file[i] = 0; 01694 } 01695 dhcp->msg_out->cookie = PP_HTONL(DHCP_MAGIC_COOKIE); 01696 dhcp->options_out_len = 0; 01697 /* fill options field with an incrementing array (for debugging purposes) */ 01698 for (i = 0; i < DHCP_OPTIONS_LEN; i++) { 01699 dhcp->msg_out->options[i] = (u8_t)i; /* for debugging only, no matter if truncated */ 01700 } 01701 /* Add option MESSAGE_TYPE */ 01702 dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); 01703 dhcp_option_byte(dhcp, message_type); 01704 return ERR_OK; 01705 } 01706 01707 /** 01708 * Free previously allocated memory used to send a DHCP request. 01709 * 01710 * @param dhcp the dhcp struct to free the request from 01711 */ 01712 static void 01713 dhcp_delete_msg(struct dhcp *dhcp) 01714 { 01715 LWIP_ERROR("dhcp_delete_msg: dhcp != NULL", (dhcp != NULL), return;); 01716 LWIP_ASSERT("dhcp_delete_msg: dhcp->p_out != NULL", dhcp->p_out != NULL); 01717 LWIP_ASSERT("dhcp_delete_msg: dhcp->msg_out != NULL", dhcp->msg_out != NULL); 01718 if (dhcp->p_out != NULL) { 01719 pbuf_free(dhcp->p_out); 01720 } 01721 dhcp->p_out = NULL; 01722 dhcp->msg_out = NULL; 01723 } 01724 01725 /** 01726 * Add a DHCP message trailer 01727 * 01728 * Adds the END option to the DHCP message, and if 01729 * necessary, up to three padding bytes. 01730 * 01731 * @param dhcp DHCP state structure 01732 */ 01733 static void 01734 dhcp_option_trailer(struct dhcp *dhcp) 01735 { 01736 LWIP_ERROR("dhcp_option_trailer: dhcp != NULL", (dhcp != NULL), return;); 01737 LWIP_ASSERT("dhcp_option_trailer: dhcp->msg_out != NULL\n", dhcp->msg_out != NULL); 01738 LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN); 01739 dhcp->msg_out->options[dhcp->options_out_len++] = DHCP_OPTION_END; 01740 /* packet is too small, or not 4 byte aligned? */ 01741 while ((dhcp->options_out_len < DHCP_MIN_OPTIONS_LEN) || (dhcp->options_out_len & 3)) { 01742 /* 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)); */ 01743 LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN); 01744 /* add a fill/padding byte */ 01745 dhcp->msg_out->options[dhcp->options_out_len++] = 0; 01746 } 01747 } 01748 01749 #endif /* LWIP_DHCP */
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