Simon Ford
Version of http://mbed.org/cookbook/NetServicesTribute with setting set the same for LPC2368
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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(dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n) && (n < DNS_MAX_SERVERS)) { 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 /** 00596 * Start DHCP negotiation for a network interface. 00597 * 00598 * If no DHCP client instance was attached to this interface, 00599 * a new client is created first. If a DHCP client instance 00600 * was already present, it restarts negotiation. 00601 * 00602 * @param netif The lwIP network interface 00603 * @return lwIP error code 00604 * - ERR_OK - No error 00605 * - ERR_MEM - Out of memory 00606 */ 00607 err_t 00608 dhcp_start(struct netif *netif) 00609 { 00610 struct dhcp *dhcp; 00611 err_t result = ERR_OK; 00612 00613 LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;); 00614 dhcp = netif->dhcp; 00615 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)); 00616 /* Remove the flag that says this netif is handled by DHCP, 00617 it is set when we succeeded starting. */ 00618 netif->flags &= ~NETIF_FLAG_DHCP; 00619 00620 /* check hwtype of the netif */ 00621 if ((netif->flags & NETIF_FLAG_ETHARP) == 0) { 00622 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): No ETHARP netif\n")); 00623 return ERR_ARG; 00624 } 00625 00626 /* check MTU of the netif */ 00627 if (netif->mtu < DHCP_MAX_MSG_LEN_MIN_REQUIRED) { 00628 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): Cannot use this netif with DHCP: MTU is too small\n")); 00629 return ERR_MEM; 00630 } 00631 00632 /* no DHCP client attached yet? */ 00633 if (dhcp == NULL) { 00634 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting new DHCP client\n")); 00635 dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp)); 00636 if (dhcp == NULL) { 00637 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n")); 00638 return ERR_MEM; 00639 } 00640 /* store this dhcp client in the netif */ 00641 netif->dhcp = dhcp; 00642 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): allocated dhcp")); 00643 /* already has DHCP client attached */ 00644 } else { 00645 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(): restarting DHCP configuration\n")); 00646 if (dhcp->pcb != NULL) { 00647 udp_remove(dhcp->pcb); 00648 } 00649 LWIP_ASSERT("pbuf p_out wasn't freed", dhcp->p_out == NULL); 00650 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL ); 00651 } 00652 00653 /* clear data structure */ 00654 memset(dhcp, 0, sizeof(struct dhcp)); 00655 /* dhcp_set_state(&dhcp, DHCP_OFF); */ 00656 /* allocate UDP PCB */ 00657 dhcp->pcb = udp_new(); 00658 if (dhcp->pcb == NULL) { 00659 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not obtain pcb\n")); 00660 return ERR_MEM; 00661 } 00662 dhcp->pcb->so_options |= SOF_BROADCAST; 00663 /* set up local and remote port for the pcb */ 00664 udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); 00665 udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); 00666 /* set up the recv callback and argument */ 00667 udp_recv(dhcp->pcb, dhcp_recv, netif); 00668 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n")); 00669 /* (re)start the DHCP negotiation */ 00670 result = dhcp_discover(netif); 00671 if (result != ERR_OK) { 00672 /* free resources allocated above */ 00673 dhcp_stop(netif); 00674 return ERR_MEM; 00675 } 00676 /* Set the flag that says this netif is handled by DHCP. */ 00677 netif->flags |= NETIF_FLAG_DHCP; 00678 return result; 00679 } 00680 00681 /** 00682 * Inform a DHCP server of our manual configuration. 00683 * 00684 * This informs DHCP servers of our fixed IP address configuration 00685 * by sending an INFORM message. It does not involve DHCP address 00686 * configuration, it is just here to be nice to the network. 00687 * 00688 * @param netif The lwIP network interface 00689 */ 00690 void 00691 dhcp_inform(struct netif *netif) 00692 { 00693 struct dhcp dhcp; 00694 err_t result = ERR_OK; 00695 struct udp_pcb *pcb; 00696 00697 LWIP_ERROR("netif != NULL", (netif != NULL), return;); 00698 00699 memset(&dhcp, 0, sizeof(struct dhcp)); 00700 dhcp_set_state(&dhcp, DHCP_INFORM); 00701 00702 if ((netif->dhcp != NULL) && (netif->dhcp->pcb != NULL)) { 00703 /* re-use existing pcb */ 00704 pcb = netif->dhcp->pcb; 00705 } else { 00706 pcb = udp_new(); 00707 if (pcb == NULL) { 00708 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform(): could not obtain pcb")); 00709 return; 00710 } 00711 dhcp.pcb = pcb; 00712 dhcp.pcb->so_options |= SOF_BROADCAST; 00713 udp_bind(dhcp.pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); 00714 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_inform(): created new udp pcb\n")); 00715 } 00716 /* create and initialize the DHCP message header */ 00717 result = dhcp_create_msg(netif, &dhcp, DHCP_INFORM); 00718 if (result == ERR_OK) { 00719 dhcp_option(&dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 00720 dhcp_option_short(&dhcp, DHCP_MAX_MSG_LEN(netif)); 00721 00722 dhcp_option_trailer(&dhcp); 00723 00724 pbuf_realloc(dhcp.p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp.options_out_len); 00725 00726 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n")); 00727 udp_sendto_if(pcb, dhcp.p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 00728 dhcp_delete_msg(&dhcp); 00729 } else { 00730 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform: could not allocate DHCP request\n")); 00731 } 00732 00733 if (dhcp.pcb != NULL) { 00734 /* otherwise, the existing pcb was used */ 00735 udp_remove(dhcp.pcb); 00736 } 00737 } 00738 00739 /** Handle a possible change in the network configuration. 00740 * 00741 * This enters the REBOOTING state to verify that the currently bound 00742 * address is still valid. 00743 */ 00744 void 00745 dhcp_network_changed(struct netif *netif) 00746 { 00747 struct dhcp *dhcp = netif->dhcp; 00748 if (!dhcp) 00749 return; 00750 switch (dhcp->state) { 00751 case DHCP_REBINDING: 00752 case DHCP_RENEWING: 00753 case DHCP_BOUND: 00754 case DHCP_REBOOTING: 00755 netif_set_down(netif); 00756 dhcp->tries = 0; 00757 dhcp_reboot(netif); 00758 break; 00759 case DHCP_OFF: 00760 /* stay off */ 00761 break; 00762 default: 00763 dhcp->tries = 0; 00764 #if LWIP_DHCP_AUTOIP_COOP 00765 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; 00766 #endif /* LWIP_DHCP_AUTOIP_COOP */ 00767 dhcp_discover(netif); 00768 break; 00769 } 00770 } 00771 00772 #if DHCP_DOES_ARP_CHECK 00773 /** 00774 * Match an ARP reply with the offered IP address. 00775 * 00776 * @param netif the network interface on which the reply was received 00777 * @param addr The IP address we received a reply from 00778 */ 00779 void dhcp_arp_reply(struct netif *netif, ip_addr_t *addr) 00780 { 00781 LWIP_ERROR("netif != NULL", (netif != NULL), return;); 00782 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_arp_reply()\n")); 00783 /* is a DHCP client doing an ARP check? */ 00784 if ((netif->dhcp != NULL) && (netif->dhcp->state == DHCP_CHECKING)) { 00785 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_arp_reply(): CHECKING, arp reply for 0x%08"X32_F"\n", 00786 ip4_addr_get_u32(addr))); 00787 /* did a host respond with the address we 00788 were offered by the DHCP server? */ 00789 if (ip_addr_cmp(addr, &netif->dhcp->offered_ip_addr)) { 00790 /* we will not accept the offered address */ 00791 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING, 00792 ("dhcp_arp_reply(): arp reply matched with offered address, declining\n")); 00793 dhcp_decline(netif); 00794 } 00795 } 00796 } 00797 00798 /** 00799 * Decline an offered lease. 00800 * 00801 * Tell the DHCP server we do not accept the offered address. 00802 * One reason to decline the lease is when we find out the address 00803 * is already in use by another host (through ARP). 00804 * 00805 * @param netif the netif under DHCP control 00806 */ 00807 static err_t 00808 dhcp_decline(struct netif *netif) 00809 { 00810 struct dhcp *dhcp = netif->dhcp; 00811 err_t result = ERR_OK; 00812 u16_t msecs; 00813 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline()\n")); 00814 dhcp_set_state(dhcp, DHCP_BACKING_OFF); 00815 /* create and initialize the DHCP message header */ 00816 result = dhcp_create_msg(netif, dhcp, DHCP_DECLINE); 00817 if (result == ERR_OK) { 00818 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 00819 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); 00820 00821 dhcp_option_trailer(dhcp); 00822 /* resize pbuf to reflect true size of options */ 00823 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 00824 00825 /* per section 4.4.4, broadcast DECLINE messages */ 00826 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 00827 dhcp_delete_msg(dhcp); 00828 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_decline: BACKING OFF\n")); 00829 } else { 00830 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 00831 ("dhcp_decline: could not allocate DHCP request\n")); 00832 } 00833 dhcp->tries++; 00834 msecs = 10*1000; 00835 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 00836 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs)); 00837 return result; 00838 } 00839 #endif /* DHCP_DOES_ARP_CHECK */ 00840 00841 00842 /** 00843 * Start the DHCP process, discover a DHCP server. 00844 * 00845 * @param netif the netif under DHCP control 00846 */ 00847 static err_t 00848 dhcp_discover(struct netif *netif) 00849 { 00850 struct dhcp *dhcp = netif->dhcp; 00851 err_t result = ERR_OK; 00852 u16_t msecs; 00853 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover()\n")); 00854 ip_addr_set_any(&dhcp->offered_ip_addr); 00855 dhcp_set_state(dhcp, DHCP_SELECTING); 00856 /* create and initialize the DHCP message header */ 00857 result = dhcp_create_msg(netif, dhcp, DHCP_DISCOVER); 00858 if (result == ERR_OK) { 00859 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n")); 00860 00861 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 00862 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 00863 00864 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/); 00865 dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK); 00866 dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER); 00867 dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST); 00868 dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER); 00869 00870 dhcp_option_trailer(dhcp); 00871 00872 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: realloc()ing\n")); 00873 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 00874 00875 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, DHCP_SERVER_PORT)\n")); 00876 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 00877 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()ing\n")); 00878 dhcp_delete_msg(dhcp); 00879 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover: SELECTING\n")); 00880 } else { 00881 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_discover: could not allocate DHCP request\n")); 00882 } 00883 dhcp->tries++; 00884 #if LWIP_DHCP_AUTOIP_COOP 00885 if(dhcp->tries >= LWIP_DHCP_AUTOIP_COOP_TRIES && dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_OFF) { 00886 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_ON; 00887 autoip_start(netif); 00888 } 00889 #endif /* LWIP_DHCP_AUTOIP_COOP */ 00890 msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000; 00891 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 00892 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs)); 00893 return result; 00894 } 00895 00896 00897 /** 00898 * Bind the interface to the offered IP address. 00899 * 00900 * @param netif network interface to bind to the offered address 00901 */ 00902 static void 00903 dhcp_bind(struct netif *netif) 00904 { 00905 u32_t timeout; 00906 struct dhcp *dhcp; 00907 ip_addr_t sn_mask, gw_addr; 00908 LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;); 00909 dhcp = netif->dhcp; 00910 LWIP_ERROR("dhcp_bind: dhcp != NULL", (dhcp != NULL), return;); 00911 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)); 00912 00913 /* temporary DHCP lease? */ 00914 if (dhcp->offered_t1_renew != 0xffffffffUL) { 00915 /* set renewal period timer */ 00916 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew)); 00917 timeout = (dhcp->offered_t1_renew + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; 00918 if(timeout > 0xffff) { 00919 timeout = 0xffff; 00920 } 00921 dhcp->t1_timeout = (u16_t)timeout; 00922 if (dhcp->t1_timeout == 0) { 00923 dhcp->t1_timeout = 1; 00924 } 00925 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew*1000)); 00926 } 00927 /* set renewal period timer */ 00928 if (dhcp->offered_t2_rebind != 0xffffffffUL) { 00929 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind)); 00930 timeout = (dhcp->offered_t2_rebind + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; 00931 if(timeout > 0xffff) { 00932 timeout = 0xffff; 00933 } 00934 dhcp->t2_timeout = (u16_t)timeout; 00935 if (dhcp->t2_timeout == 0) { 00936 dhcp->t2_timeout = 1; 00937 } 00938 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t2_rebind*1000)); 00939 } 00940 00941 if (dhcp->subnet_mask_given) { 00942 /* copy offered network mask */ 00943 ip_addr_copy(sn_mask, dhcp->offered_sn_mask); 00944 } else { 00945 /* subnet mask not given, choose a safe subnet mask given the network class */ 00946 u8_t first_octet = ip4_addr1(&dhcp->offered_ip_addr); 00947 if (first_octet <= 127) { 00948 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xff000000)); 00949 } else if (first_octet >= 192) { 00950 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffffff00)); 00951 } else { 00952 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffff0000)); 00953 } 00954 } 00955 00956 ip_addr_copy(gw_addr, dhcp->offered_gw_addr); 00957 /* gateway address not given? */ 00958 if (ip_addr_isany(&gw_addr)) { 00959 /* copy network address */ 00960 ip_addr_get_network(&gw_addr, &dhcp->offered_ip_addr, &sn_mask); 00961 /* use first host address on network as gateway */ 00962 ip4_addr_set_u32(&gw_addr, ip4_addr_get_u32(&gw_addr) | PP_HTONL(0x00000001)); 00963 } 00964 00965 #if LWIP_DHCP_AUTOIP_COOP 00966 if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { 00967 autoip_stop(netif); 00968 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; 00969 } 00970 #endif /* LWIP_DHCP_AUTOIP_COOP */ 00971 00972 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): IP: 0x%08"X32_F"\n", 00973 ip4_addr_get_u32(&dhcp->offered_ip_addr))); 00974 netif_set_ipaddr(netif, &dhcp->offered_ip_addr); 00975 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): SN: 0x%08"X32_F"\n", 00976 ip4_addr_get_u32(&sn_mask))); 00977 netif_set_netmask(netif, &sn_mask); 00978 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): GW: 0x%08"X32_F"\n", 00979 ip4_addr_get_u32(&gw_addr))); 00980 netif_set_gw(netif, &gw_addr); 00981 /* bring the interface up */ 00982 netif_set_up(netif); 00983 /* netif is now bound to DHCP leased address */ 00984 dhcp_set_state(dhcp, DHCP_BOUND); 00985 } 00986 00987 /** 00988 * Renew an existing DHCP lease at the involved DHCP server. 00989 * 00990 * @param netif network interface which must renew its lease 00991 */ 00992 err_t 00993 dhcp_renew(struct netif *netif) 00994 { 00995 struct dhcp *dhcp = netif->dhcp; 00996 err_t result; 00997 u16_t msecs; 00998 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_renew()\n")); 00999 dhcp_set_state(dhcp, DHCP_RENEWING); 01000 01001 /* create and initialize the DHCP message header */ 01002 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 01003 if (result == ERR_OK) { 01004 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 01005 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 01006 01007 #if LWIP_NETIF_HOSTNAME 01008 if (netif->hostname != NULL) { 01009 const char *p = (const char*)netif->hostname; 01010 u8_t namelen = (u8_t)strlen(p); 01011 if (namelen > 0) { 01012 LWIP_ASSERT("DHCP: hostname is too long!", namelen < 255); 01013 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, namelen); 01014 while (*p) { 01015 dhcp_option_byte(dhcp, *p++); 01016 } 01017 } 01018 } 01019 #endif /* LWIP_NETIF_HOSTNAME */ 01020 01021 #if 0 01022 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 01023 dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); 01024 #endif 01025 01026 #if 0 01027 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); 01028 dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr)); 01029 #endif 01030 /* append DHCP message trailer */ 01031 dhcp_option_trailer(dhcp); 01032 01033 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 01034 01035 udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif); 01036 dhcp_delete_msg(dhcp); 01037 01038 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew: RENEWING\n")); 01039 } else { 01040 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_renew: could not allocate DHCP request\n")); 01041 } 01042 dhcp->tries++; 01043 /* back-off on retries, but to a maximum of 20 seconds */ 01044 msecs = dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000; 01045 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 01046 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs)); 01047 return result; 01048 } 01049 01050 /** 01051 * Rebind with a DHCP server for an existing DHCP lease. 01052 * 01053 * @param netif network interface which must rebind with a DHCP server 01054 */ 01055 static err_t 01056 dhcp_rebind(struct netif *netif) 01057 { 01058 struct dhcp *dhcp = netif->dhcp; 01059 err_t result; 01060 u16_t msecs; 01061 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n")); 01062 dhcp_set_state(dhcp, DHCP_REBINDING); 01063 01064 /* create and initialize the DHCP message header */ 01065 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 01066 if (result == ERR_OK) { 01067 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 01068 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 01069 01070 #if LWIP_NETIF_HOSTNAME 01071 if (netif->hostname != NULL) { 01072 const char *p = (const char*)netif->hostname; 01073 u8_t namelen = (u8_t)strlen(p); 01074 if (namelen > 0) { 01075 LWIP_ASSERT("DHCP: hostname is too long!", namelen < 255); 01076 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, namelen); 01077 while (*p) { 01078 dhcp_option_byte(dhcp, *p++); 01079 } 01080 } 01081 } 01082 #endif /* LWIP_NETIF_HOSTNAME */ 01083 01084 #if 0 01085 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 01086 dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); 01087 01088 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); 01089 dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr)); 01090 #endif 01091 01092 dhcp_option_trailer(dhcp); 01093 01094 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 01095 01096 /* broadcast to server */ 01097 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 01098 dhcp_delete_msg(dhcp); 01099 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n")); 01100 } else { 01101 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_rebind: could not allocate DHCP request\n")); 01102 } 01103 dhcp->tries++; 01104 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; 01105 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 01106 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs)); 01107 return result; 01108 } 01109 01110 /** 01111 * Enter REBOOTING state to verify an existing lease 01112 * 01113 * @param netif network interface which must reboot 01114 */ 01115 static err_t 01116 dhcp_reboot(struct netif *netif) 01117 { 01118 struct dhcp *dhcp = netif->dhcp; 01119 err_t result; 01120 u16_t msecs; 01121 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n")); 01122 dhcp_set_state(dhcp, DHCP_REBOOTING); 01123 01124 /* create and initialize the DHCP message header */ 01125 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 01126 if (result == ERR_OK) { 01127 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 01128 dhcp_option_short(dhcp, 576); 01129 01130 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 01131 dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); 01132 01133 dhcp_option_trailer(dhcp); 01134 01135 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 01136 01137 /* broadcast to server */ 01138 udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 01139 dhcp_delete_msg(dhcp); 01140 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot: REBOOTING\n")); 01141 } else { 01142 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_reboot: could not allocate DHCP request\n")); 01143 } 01144 dhcp->tries++; 01145 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; 01146 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 01147 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot(): set request timeout %"U16_F" msecs\n", msecs)); 01148 return result; 01149 } 01150 01151 01152 /** 01153 * Release a DHCP lease. 01154 * 01155 * @param netif network interface which must release its lease 01156 */ 01157 err_t 01158 dhcp_release(struct netif *netif) 01159 { 01160 struct dhcp *dhcp = netif->dhcp; 01161 err_t result; 01162 u16_t msecs; 01163 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release()\n")); 01164 01165 /* idle DHCP client */ 01166 dhcp_set_state(dhcp, DHCP_OFF); 01167 /* clean old DHCP offer */ 01168 ip_addr_set_zero(&dhcp->server_ip_addr); 01169 ip_addr_set_zero(&dhcp->offered_ip_addr); 01170 ip_addr_set_zero(&dhcp->offered_sn_mask); 01171 ip_addr_set_zero(&dhcp->offered_gw_addr); 01172 #if LWIP_DHCP_BOOTP_FILE 01173 ip_addr_set_zero(&dhcp->offered_si_addr); 01174 #endif /* LWIP_DHCP_BOOTP_FILE */ 01175 dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0; 01176 01177 /* create and initialize the DHCP message header */ 01178 result = dhcp_create_msg(netif, dhcp, DHCP_RELEASE); 01179 if (result == ERR_OK) { 01180 dhcp_option_trailer(dhcp); 01181 01182 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 01183 01184 udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif); 01185 dhcp_delete_msg(dhcp); 01186 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_OFF\n")); 01187 } else { 01188 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n")); 01189 } 01190 dhcp->tries++; 01191 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; 01192 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 01193 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release(): set request timeout %"U16_F" msecs\n", msecs)); 01194 /* bring the interface down */ 01195 netif_set_down(netif); 01196 /* remove IP address from interface */ 01197 netif_set_ipaddr(netif, IP_ADDR_ANY); 01198 netif_set_gw(netif, IP_ADDR_ANY); 01199 netif_set_netmask(netif, IP_ADDR_ANY); 01200 01201 return result; 01202 } 01203 01204 /** 01205 * Remove the DHCP client from the interface. 01206 * 01207 * @param netif The network interface to stop DHCP on 01208 */ 01209 void 01210 dhcp_stop(struct netif *netif) 01211 { 01212 struct dhcp *dhcp; 01213 LWIP_ERROR("dhcp_stop: netif != NULL", (netif != NULL), return;); 01214 dhcp = netif->dhcp; 01215 /* Remove the flag that says this netif is handled by DHCP. */ 01216 netif->flags &= ~NETIF_FLAG_DHCP; 01217 01218 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_stop()\n")); 01219 /* netif is DHCP configured? */ 01220 if (dhcp != NULL) { 01221 #if LWIP_DHCP_AUTOIP_COOP 01222 if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { 01223 autoip_stop(netif); 01224 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; 01225 } 01226 #endif /* LWIP_DHCP_AUTOIP_COOP */ 01227 01228 if (dhcp->pcb != NULL) { 01229 udp_remove(dhcp->pcb); 01230 dhcp->pcb = NULL; 01231 } 01232 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL); 01233 dhcp_set_state(dhcp, DHCP_OFF); 01234 } 01235 } 01236 01237 /* 01238 * Set the DHCP state of a DHCP client. 01239 * 01240 * If the state changed, reset the number of tries. 01241 */ 01242 static void 01243 dhcp_set_state(struct dhcp *dhcp, u8_t new_state) 01244 { 01245 if (new_state != dhcp->state) { 01246 dhcp->state = new_state; 01247 dhcp->tries = 0; 01248 dhcp->request_timeout = 0; 01249 } 01250 } 01251 01252 /* 01253 * Concatenate an option type and length field to the outgoing 01254 * DHCP message. 01255 * 01256 */ 01257 static void 01258 dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len) 01259 { 01260 LWIP_ASSERT("dhcp_option: dhcp->options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN); 01261 dhcp->msg_out->options[dhcp->options_out_len++] = option_type; 01262 dhcp->msg_out->options[dhcp->options_out_len++] = option_len; 01263 } 01264 /* 01265 * Concatenate a single byte to the outgoing DHCP message. 01266 * 01267 */ 01268 static void 01269 dhcp_option_byte(struct dhcp *dhcp, u8_t value) 01270 { 01271 LWIP_ASSERT("dhcp_option_byte: dhcp->options_out_len < DHCP_OPTIONS_LEN", dhcp->options_out_len < DHCP_OPTIONS_LEN); 01272 dhcp->msg_out->options[dhcp->options_out_len++] = value; 01273 } 01274 01275 static void 01276 dhcp_option_short(struct dhcp *dhcp, u16_t value) 01277 { 01278 LWIP_ASSERT("dhcp_option_short: dhcp->options_out_len + 2 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U <= DHCP_OPTIONS_LEN); 01279 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff00U) >> 8); 01280 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t) (value & 0x00ffU); 01281 } 01282 01283 static void 01284 dhcp_option_long(struct dhcp *dhcp, u32_t value) 01285 { 01286 LWIP_ASSERT("dhcp_option_long: dhcp->options_out_len + 4 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 4U <= DHCP_OPTIONS_LEN); 01287 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24); 01288 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16); 01289 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8); 01290 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x000000ffUL)); 01291 } 01292 01293 /** 01294 * Extract the DHCP message and the DHCP options. 01295 * 01296 * Extract the DHCP message and the DHCP options, each into a contiguous 01297 * piece of memory. As a DHCP message is variable sized by its options, 01298 * and also allows overriding some fields for options, the easy approach 01299 * is to first unfold the options into a conitguous piece of memory, and 01300 * use that further on. 01301 * 01302 */ 01303 static err_t 01304 dhcp_parse_reply(struct dhcp *dhcp, struct pbuf *p) 01305 { 01306 u8_t *options; 01307 u16_t offset; 01308 u16_t offset_max; 01309 u16_t options_idx; 01310 u16_t options_idx_max; 01311 struct pbuf *q; 01312 int parse_file_as_options = 0; 01313 int parse_sname_as_options = 0; 01314 01315 /* clear received options */ 01316 dhcp_clear_all_options(dhcp); 01317 /* check that beginning of dhcp_msg (up to and including chaddr) is in first pbuf */ 01318 if (p->len < DHCP_SNAME_OFS) { 01319 return ERR_BUF; 01320 } 01321 dhcp->msg_in = (struct dhcp_msg *)p->payload; 01322 #if LWIP_DHCP_BOOTP_FILE 01323 /* clear boot file name */ 01324 dhcp->boot_file_name[0] = 0; 01325 #endif /* LWIP_DHCP_BOOTP_FILE */ 01326 01327 /* parse options */ 01328 01329 /* start with options field */ 01330 options_idx = DHCP_OPTIONS_OFS; 01331 /* parse options to the end of the received packet */ 01332 options_idx_max = p->tot_len; 01333 again: 01334 q = p; 01335 while((q != NULL) && (options_idx >= q->len)) { 01336 options_idx -= q->len; 01337 options_idx_max -= q->len; 01338 q = q->next; 01339 } 01340 if (q == NULL) { 01341 return ERR_BUF; 01342 } 01343 offset = options_idx; 01344 offset_max = options_idx_max; 01345 options = (u8_t*)q->payload; 01346 /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */ 01347 while((q != NULL) && (options[offset] != DHCP_OPTION_END) && (offset < offset_max)) { 01348 u8_t op = options[offset]; 01349 u8_t len; 01350 u8_t decode_len = 0; 01351 int decode_idx = -1; 01352 u16_t val_offset = offset + 2; 01353 /* len byte might be in the next pbuf */ 01354 if (offset + 1 < q->len) { 01355 len = options[offset + 1]; 01356 } else { 01357 len = (q->next != NULL ? ((u8_t*)q->next->payload)[0] : 0); 01358 } 01359 /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F, msg_offset, q->len)); */ 01360 decode_len = len; 01361 switch(op) { 01362 /* case(DHCP_OPTION_END): handled above */ 01363 case(DHCP_OPTION_PAD): 01364 /* special option: no len encoded */ 01365 decode_len = len = 0; 01366 /* will be increased below */ 01367 offset--; 01368 break; 01369 case(DHCP_OPTION_SUBNET_MASK): 01370 LWIP_ASSERT("len == 4", len == 4); 01371 decode_idx = DHCP_OPTION_IDX_SUBNET_MASK; 01372 break; 01373 case(DHCP_OPTION_ROUTER): 01374 decode_len = 4; /* only copy the first given router */ 01375 LWIP_ASSERT("len >= decode_len", len >= decode_len); 01376 decode_idx = DHCP_OPTION_IDX_ROUTER; 01377 break; 01378 case(DHCP_OPTION_DNS_SERVER): 01379 /* special case: there might be more than one server */ 01380 LWIP_ASSERT("len % 4 == 0", len % 4 == 0); 01381 /* limit number of DNS servers */ 01382 decode_len = LWIP_MIN(len, 4 * DNS_MAX_SERVERS); 01383 LWIP_ASSERT("len >= decode_len", len >= decode_len); 01384 decode_idx = DHCP_OPTION_IDX_DNS_SERVER; 01385 break; 01386 case(DHCP_OPTION_LEASE_TIME): 01387 LWIP_ASSERT("len == 4", len == 4); 01388 decode_idx = DHCP_OPTION_IDX_LEASE_TIME; 01389 break; 01390 case(DHCP_OPTION_OVERLOAD): 01391 LWIP_ASSERT("len == 1", len == 1); 01392 decode_idx = DHCP_OPTION_IDX_OVERLOAD; 01393 break; 01394 case(DHCP_OPTION_MESSAGE_TYPE): 01395 LWIP_ASSERT("len == 1", len == 1); 01396 decode_idx = DHCP_OPTION_IDX_MSG_TYPE; 01397 break; 01398 case(DHCP_OPTION_SERVER_ID): 01399 LWIP_ASSERT("len == 4", len == 4); 01400 decode_idx = DHCP_OPTION_IDX_SERVER_ID; 01401 break; 01402 case(DHCP_OPTION_T1): 01403 LWIP_ASSERT("len == 4", len == 4); 01404 decode_idx = DHCP_OPTION_IDX_T1; 01405 break; 01406 case(DHCP_OPTION_T2): 01407 LWIP_ASSERT("len == 4", len == 4); 01408 decode_idx = DHCP_OPTION_IDX_T2; 01409 break; 01410 default: 01411 decode_len = 0; 01412 LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", op)); 01413 break; 01414 } 01415 offset += len + 2; 01416 if (decode_len > 0) { 01417 u32_t value = 0; 01418 u16_t copy_len; 01419 decode_next: 01420 LWIP_ASSERT("check decode_idx", decode_idx >= 0 && decode_idx < DHCP_OPTION_IDX_MAX); 01421 LWIP_ASSERT("option already decoded", !dhcp_option_given(dhcp, decode_idx)); 01422 copy_len = LWIP_MIN(decode_len, 4); 01423 pbuf_copy_partial(q, &value, copy_len, val_offset); 01424 if (decode_len > 4) { 01425 /* decode more than one u32_t */ 01426 LWIP_ASSERT("decode_len % 4 == 0", decode_len % 4 == 0); 01427 dhcp_got_option(dhcp, decode_idx); 01428 dhcp_set_option_value(dhcp, decode_idx, htonl(value)); 01429 decode_len -= 4; 01430 val_offset += 4; 01431 decode_idx++; 01432 goto decode_next; 01433 } else if (decode_len == 4) { 01434 value = ntohl(value); 01435 } else { 01436 LWIP_ASSERT("invalid decode_len", decode_len == 1); 01437 value = ((u8_t*)&value)[0]; 01438 } 01439 dhcp_got_option(dhcp, decode_idx); 01440 dhcp_set_option_value(dhcp, decode_idx, value); 01441 } 01442 if (offset >= q->len) { 01443 offset -= q->len; 01444 offset_max -= q->len; 01445 q = q->next; 01446 options = (u8_t*)q->payload; 01447 } 01448 } 01449 /* is this an overloaded message? */ 01450 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_OVERLOAD)) { 01451 u32_t overload = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_OVERLOAD); 01452 dhcp_clear_option(dhcp, DHCP_OPTION_IDX_OVERLOAD); 01453 if (overload == DHCP_OVERLOAD_FILE) { 01454 parse_file_as_options = 1; 01455 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded file field\n")); 01456 } else if (overload == DHCP_OVERLOAD_SNAME) { 01457 parse_sname_as_options = 1; 01458 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname field\n")); 01459 } else if (overload == DHCP_OVERLOAD_SNAME_FILE) { 01460 parse_sname_as_options = 1; 01461 parse_file_as_options = 1; 01462 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname and file field\n")); 01463 } else { 01464 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("invalid overload option: %d\n", (int)overload)); 01465 } 01466 #if LWIP_DHCP_BOOTP_FILE 01467 if (!parse_file_as_options) { 01468 /* only do this for ACK messages */ 01469 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) && 01470 (dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK)) 01471 /* copy bootp file name, don't care for sname (server hostname) */ 01472 pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS); 01473 /* make sure the string is really NULL-terminated */ 01474 dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0; 01475 } 01476 #endif /* LWIP_DHCP_BOOTP_FILE */ 01477 } 01478 if (parse_file_as_options) { 01479 /* if both are overloaded, parse file first and then sname (RFC 2131 ch. 4.1) */ 01480 parse_file_as_options = 0; 01481 options_idx = DHCP_FILE_OFS; 01482 options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN; 01483 goto again; 01484 } else if (parse_sname_as_options) { 01485 parse_sname_as_options = 0; 01486 options_idx = DHCP_SNAME_OFS; 01487 options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN; 01488 goto again; 01489 } 01490 return ERR_OK; 01491 } 01492 01493 /** 01494 * If an incoming DHCP message is in response to us, then trigger the state machine 01495 */ 01496 static void 01497 dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port) 01498 { 01499 struct netif *netif = (struct netif *)arg; 01500 struct dhcp *dhcp = netif->dhcp; 01501 struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload; 01502 u8_t msg_type; 01503 u8_t i; 01504 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, 01505 ip4_addr1_16(addr), ip4_addr2_16(addr), ip4_addr3_16(addr), ip4_addr4_16(addr), port)); 01506 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len)); 01507 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len)); 01508 /* prevent warnings about unused arguments */ 01509 LWIP_UNUSED_ARG(pcb); 01510 LWIP_UNUSED_ARG(addr); 01511 LWIP_UNUSED_ARG(port); 01512 01513 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL); 01514 01515 if (p->len < DHCP_MIN_REPLY_LEN) { 01516 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP reply message or pbuf too short\n")); 01517 goto free_pbuf_and_return; 01518 } 01519 01520 if (reply_msg->op != DHCP_BOOTREPLY) { 01521 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)); 01522 goto free_pbuf_and_return; 01523 } 01524 /* iterate through hardware address and match against DHCP message */ 01525 for (i = 0; i < netif->hwaddr_len; i++) { 01526 if (netif->hwaddr[i] != reply_msg->chaddr[i]) { 01527 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, 01528 ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n", 01529 (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i])); 01530 goto free_pbuf_and_return; 01531 } 01532 } 01533 /* match transaction ID against what we expected */ 01534 if (ntohl(reply_msg->xid) != dhcp->xid) { 01535 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, 01536 ("transaction id mismatch reply_msg->xid(%"X32_F")!=dhcp->xid(%"X32_F")\n",ntohl(reply_msg->xid),dhcp->xid)); 01537 goto free_pbuf_and_return; 01538 } 01539 /* option fields could be unfold? */ 01540 if (dhcp_parse_reply(dhcp, p) != ERR_OK) { 01541 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 01542 ("problem unfolding DHCP message - too short on memory?\n")); 01543 goto free_pbuf_and_return; 01544 } 01545 01546 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n")); 01547 /* obtain pointer to DHCP message type */ 01548 if (!dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE)) { 01549 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP_OPTION_MESSAGE_TYPE option not found\n")); 01550 goto free_pbuf_and_return; 01551 } 01552 01553 /* read DHCP message type */ 01554 msg_type = (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE); 01555 /* message type is DHCP ACK? */ 01556 if (msg_type == DHCP_ACK) { 01557 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_ACK received\n")); 01558 /* in requesting state? */ 01559 if (dhcp->state == DHCP_REQUESTING) { 01560 dhcp_handle_ack(netif); 01561 #if DHCP_DOES_ARP_CHECK 01562 /* check if the acknowledged lease address is already in use */ 01563 dhcp_check(netif); 01564 #else 01565 /* bind interface to the acknowledged lease address */ 01566 dhcp_bind(netif); 01567 #endif 01568 } 01569 /* already bound to the given lease address? */ 01570 else if ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING)) { 01571 dhcp_bind(netif); 01572 } 01573 } 01574 /* received a DHCP_NAK in appropriate state? */ 01575 else if ((msg_type == DHCP_NAK) && 01576 ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REQUESTING) || 01577 (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING ))) { 01578 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_NAK received\n")); 01579 dhcp_handle_nak(netif); 01580 } 01581 /* received a DHCP_OFFER in DHCP_SELECTING state? */ 01582 else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_SELECTING)) { 01583 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_OFFER received in DHCP_SELECTING state\n")); 01584 dhcp->request_timeout = 0; 01585 /* remember offered lease */ 01586 dhcp_handle_offer(netif); 01587 } 01588 free_pbuf_and_return: 01589 dhcp->msg_in = NULL; 01590 pbuf_free(p); 01591 } 01592 01593 /** 01594 * Create a DHCP request, fill in common headers 01595 * 01596 * @param netif the netif under DHCP control 01597 * @param dhcp dhcp control struct 01598 * @param message_type message type of the request 01599 */ 01600 static err_t 01601 dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type) 01602 { 01603 u16_t i; 01604 #ifndef DHCP_GLOBAL_XID 01605 /** default global transaction identifier starting value (easy to match 01606 * with a packet analyser). We simply increment for each new request. 01607 * Predefine DHCP_GLOBAL_XID to a better value or a function call to generate one 01608 * at runtime, any supporting function prototypes can be defined in DHCP_GLOBAL_XID_HEADER */ 01609 static u32_t xid = 0xABCD0000; 01610 #else 01611 static u32_t xid; 01612 static u8_t xid_initialised = 0; 01613 if (!xid_initialised) { 01614 xid = DHCP_GLOBAL_XID; 01615 xid_initialised = !xid_initialised; 01616 } 01617 #endif 01618 LWIP_ERROR("dhcp_create_msg: netif != NULL", (netif != NULL), return ERR_ARG;); 01619 LWIP_ERROR("dhcp_create_msg: dhcp != NULL", (dhcp != NULL), return ERR_VAL;); 01620 LWIP_ASSERT("dhcp_create_msg: dhcp->p_out == NULL", dhcp->p_out == NULL); 01621 LWIP_ASSERT("dhcp_create_msg: dhcp->msg_out == NULL", dhcp->msg_out == NULL); 01622 dhcp->p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM); 01623 if (dhcp->p_out == NULL) { 01624 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 01625 ("dhcp_create_msg(): could not allocate pbuf\n")); 01626 return ERR_MEM; 01627 } 01628 LWIP_ASSERT("dhcp_create_msg: check that first pbuf can hold struct dhcp_msg", 01629 (dhcp->p_out->len >= sizeof(struct dhcp_msg))); 01630 01631 /* reuse transaction identifier in retransmissions */ 01632 if (dhcp->tries == 0) { 01633 xid++; 01634 } 01635 dhcp->xid = xid; 01636 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, 01637 ("transaction id xid(%"X32_F")\n", xid)); 01638 01639 dhcp->msg_out = (struct dhcp_msg *)dhcp->p_out->payload; 01640 01641 dhcp->msg_out->op = DHCP_BOOTREQUEST; 01642 /* TODO: make link layer independent */ 01643 dhcp->msg_out->htype = DHCP_HTYPE_ETH; 01644 dhcp->msg_out->hlen = netif->hwaddr_len; 01645 dhcp->msg_out->hops = 0; 01646 dhcp->msg_out->xid = htonl(dhcp->xid); 01647 dhcp->msg_out->secs = 0; 01648 /* we don't need the broadcast flag since we can receive unicast traffic 01649 before being fully configured! */ 01650 dhcp->msg_out->flags = 0; 01651 ip_addr_set_zero(&dhcp->msg_out->ciaddr); 01652 /* set ciaddr to netif->ip_addr based on message_type and state */ 01653 if ((message_type == DHCP_INFORM) || (message_type == DHCP_DECLINE) || 01654 ((message_type == DHCP_REQUEST) && /* DHCP_BOUND not used for sending! */ 01655 ((dhcp->state==DHCP_RENEWING) || dhcp->state==DHCP_REBINDING))) { 01656 ip_addr_copy(dhcp->msg_out->ciaddr, netif->ip_addr); 01657 } 01658 ip_addr_set_zero(&dhcp->msg_out->yiaddr); 01659 ip_addr_set_zero(&dhcp->msg_out->siaddr); 01660 ip_addr_set_zero(&dhcp->msg_out->giaddr); 01661 for (i = 0; i < DHCP_CHADDR_LEN; i++) { 01662 /* copy netif hardware address, pad with zeroes */ 01663 dhcp->msg_out->chaddr[i] = (i < netif->hwaddr_len) ? netif->hwaddr[i] : 0/* pad byte*/; 01664 } 01665 for (i = 0; i < DHCP_SNAME_LEN; i++) { 01666 dhcp->msg_out->sname[i] = 0; 01667 } 01668 for (i = 0; i < DHCP_FILE_LEN; i++) { 01669 dhcp->msg_out->file[i] = 0; 01670 } 01671 dhcp->msg_out->cookie = PP_HTONL(DHCP_MAGIC_COOKIE); 01672 dhcp->options_out_len = 0; 01673 /* fill options field with an incrementing array (for debugging purposes) */ 01674 for (i = 0; i < DHCP_OPTIONS_LEN; i++) { 01675 dhcp->msg_out->options[i] = (u8_t)i; /* for debugging only, no matter if truncated */ 01676 } 01677 /* Add option MESSAGE_TYPE */ 01678 dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); 01679 dhcp_option_byte(dhcp, message_type); 01680 return ERR_OK; 01681 } 01682 01683 /** 01684 * Free previously allocated memory used to send a DHCP request. 01685 * 01686 * @param dhcp the dhcp struct to free the request from 01687 */ 01688 static void 01689 dhcp_delete_msg(struct dhcp *dhcp) 01690 { 01691 LWIP_ERROR("dhcp_delete_msg: dhcp != NULL", (dhcp != NULL), return;); 01692 LWIP_ASSERT("dhcp_delete_msg: dhcp->p_out != NULL", dhcp->p_out != NULL); 01693 LWIP_ASSERT("dhcp_delete_msg: dhcp->msg_out != NULL", dhcp->msg_out != NULL); 01694 if (dhcp->p_out != NULL) { 01695 pbuf_free(dhcp->p_out); 01696 } 01697 dhcp->p_out = NULL; 01698 dhcp->msg_out = NULL; 01699 } 01700 01701 /** 01702 * Add a DHCP message trailer 01703 * 01704 * Adds the END option to the DHCP message, and if 01705 * necessary, up to three padding bytes. 01706 * 01707 * @param dhcp DHCP state structure 01708 */ 01709 static void 01710 dhcp_option_trailer(struct dhcp *dhcp) 01711 { 01712 LWIP_ERROR("dhcp_option_trailer: dhcp != NULL", (dhcp != NULL), return;); 01713 LWIP_ASSERT("dhcp_option_trailer: dhcp->msg_out != NULL\n", dhcp->msg_out != NULL); 01714 LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN); 01715 dhcp->msg_out->options[dhcp->options_out_len++] = DHCP_OPTION_END; 01716 /* packet is too small, or not 4 byte aligned? */ 01717 while ((dhcp->options_out_len < DHCP_MIN_OPTIONS_LEN) || (dhcp->options_out_len & 3)) { 01718 /* 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)); */ 01719 LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN); 01720 /* add a fill/padding byte */ 01721 dhcp->msg_out->options[dhcp->options_out_len++] = 0; 01722 } 01723 } 01724 01725 #endif /* LWIP_DHCP */
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