Marco Zecchini
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lwip_dhcp.c
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00001 /** 00002 * @file 00003 * Dynamic Host Configuration Protocol client 00004 * 00005 * @defgroup dhcp4 DHCPv4 00006 * @ingroup ip4 00007 * DHCP (IPv4) related functions 00008 * This is a DHCP client for the lwIP TCP/IP stack. It aims to conform 00009 * with RFC 2131 and RFC 2132. 00010 * 00011 * @todo: 00012 * - Support for interfaces other than Ethernet (SLIP, PPP, ...) 00013 * 00014 * Options: 00015 * @ref DHCP_COARSE_TIMER_SECS (recommended 60 which is a minute) 00016 * @ref DHCP_FINE_TIMER_MSECS (recommended 500 which equals TCP coarse timer) 00017 * 00018 * dhcp_start() starts a DHCP client instance which 00019 * configures the interface by obtaining an IP address lease and maintaining it. 00020 * 00021 * Use dhcp_release() to end the lease and use dhcp_stop() 00022 * to remove the DHCP client. 00023 * 00024 * @see netifapi_dhcp4 00025 */ 00026 00027 /* 00028 * Copyright (c) 2001-2004 Leon Woestenberg <leon.woestenberg@gmx.net> 00029 * Copyright (c) 2001-2004 Axon Digital Design B.V., The Netherlands. 00030 * All rights reserved. 00031 * 00032 * Redistribution and use in source and binary forms, with or without modification, 00033 * are permitted provided that the following conditions are met: 00034 * 00035 * 1. Redistributions of source code must retain the above copyright notice, 00036 * this list of conditions and the following disclaimer. 00037 * 2. Redistributions in binary form must reproduce the above copyright notice, 00038 * this list of conditions and the following disclaimer in the documentation 00039 * and/or other materials provided with the distribution. 00040 * 3. The name of the author may not be used to endorse or promote products 00041 * derived from this software without specific prior written permission. 00042 * 00043 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 00044 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00045 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 00046 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00047 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 00048 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00049 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00050 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 00051 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 00052 * OF SUCH DAMAGE. 00053 * 00054 * This file is part of the lwIP TCP/IP stack. 00055 * The Swedish Institute of Computer Science and Adam Dunkels 00056 * are specifically granted permission to redistribute this 00057 * source code. 00058 * 00059 * Author: Leon Woestenberg <leon.woestenberg@gmx.net> 00060 * 00061 */ 00062 00063 #include "lwip/opt.h" 00064 00065 #if LWIP_IPV4 && LWIP_DHCP /* don't build if not configured for use in lwipopts.h */ 00066 00067 #include "lwip/stats.h" 00068 #include "lwip/mem.h" 00069 #include "lwip/udp.h" 00070 #include "lwip/ip_addr.h" 00071 #include "lwip/netif.h" 00072 #include "lwip/def.h" 00073 #include "lwip/dhcp.h" 00074 #include "lwip/autoip.h" 00075 #include "lwip/dns.h" 00076 #include "lwip/etharp.h" 00077 #include "lwip/prot/dhcp.h" 00078 00079 #include <string.h> 00080 00081 /** DHCP_CREATE_RAND_XID: if this is set to 1, the xid is created using 00082 * LWIP_RAND() (this overrides DHCP_GLOBAL_XID) 00083 */ 00084 #ifndef DHCP_CREATE_RAND_XID 00085 #define DHCP_CREATE_RAND_XID 1 00086 #endif 00087 00088 /** Default for DHCP_GLOBAL_XID is 0xABCD0000 00089 * This can be changed by defining DHCP_GLOBAL_XID and DHCP_GLOBAL_XID_HEADER, e.g. 00090 * \#define DHCP_GLOBAL_XID_HEADER "stdlib.h" 00091 * \#define DHCP_GLOBAL_XID rand() 00092 */ 00093 #ifdef DHCP_GLOBAL_XID_HEADER 00094 #include DHCP_GLOBAL_XID_HEADER /* include optional starting XID generation prototypes */ 00095 #endif 00096 00097 /** DHCP_OPTION_MAX_MSG_SIZE is set to the MTU 00098 * MTU is checked to be big enough in dhcp_start */ 00099 #define DHCP_MAX_MSG_LEN(netif) (netif->mtu) 00100 #define DHCP_MAX_MSG_LEN_MIN_REQUIRED 576 00101 /** Minimum length for reply before packet is parsed */ 00102 #define DHCP_MIN_REPLY_LEN 44 00103 00104 #define REBOOT_TRIES 2 00105 00106 #if LWIP_DNS && LWIP_DHCP_MAX_DNS_SERVERS 00107 #if DNS_MAX_SERVERS > LWIP_DHCP_MAX_DNS_SERVERS 00108 #define LWIP_DHCP_PROVIDE_DNS_SERVERS LWIP_DHCP_MAX_DNS_SERVERS 00109 #else 00110 #define LWIP_DHCP_PROVIDE_DNS_SERVERS DNS_MAX_SERVERS 00111 #endif 00112 #else 00113 #define LWIP_DHCP_PROVIDE_DNS_SERVERS 0 00114 #endif 00115 00116 /** Option handling: options are parsed in dhcp_parse_reply 00117 * and saved in an array where other functions can load them from. 00118 * This might be moved into the struct dhcp (not necessarily since 00119 * lwIP is single-threaded and the array is only used while in recv 00120 * callback). */ 00121 enum dhcp_option_idx { 00122 DHCP_OPTION_IDX_OVERLOAD = 0, 00123 DHCP_OPTION_IDX_MSG_TYPE, 00124 DHCP_OPTION_IDX_SERVER_ID, 00125 DHCP_OPTION_IDX_LEASE_TIME, 00126 DHCP_OPTION_IDX_T1, 00127 DHCP_OPTION_IDX_T2, 00128 DHCP_OPTION_IDX_SUBNET_MASK, 00129 DHCP_OPTION_IDX_ROUTER, 00130 #if LWIP_DHCP_PROVIDE_DNS_SERVERS 00131 DHCP_OPTION_IDX_DNS_SERVER, 00132 DHCP_OPTION_IDX_DNS_SERVER_LAST = DHCP_OPTION_IDX_DNS_SERVER + LWIP_DHCP_PROVIDE_DNS_SERVERS - 1, 00133 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ 00134 #if LWIP_DHCP_GET_NTP_SRV 00135 DHCP_OPTION_IDX_NTP_SERVER, 00136 DHCP_OPTION_IDX_NTP_SERVER_LAST = DHCP_OPTION_IDX_NTP_SERVER + LWIP_DHCP_MAX_NTP_SERVERS - 1, 00137 #endif /* LWIP_DHCP_GET_NTP_SRV */ 00138 DHCP_OPTION_IDX_MAX 00139 }; 00140 00141 /** Holds the decoded option values, only valid while in dhcp_recv. 00142 @todo: move this into struct dhcp? */ 00143 u32_t dhcp_rx_options_val[DHCP_OPTION_IDX_MAX]; 00144 /** Holds a flag which option was received and is contained in dhcp_rx_options_val, 00145 only valid while in dhcp_recv. 00146 @todo: move this into struct dhcp? */ 00147 u8_t dhcp_rx_options_given[DHCP_OPTION_IDX_MAX]; 00148 00149 static u8_t dhcp_discover_request_options[] = { 00150 DHCP_OPTION_SUBNET_MASK, 00151 DHCP_OPTION_ROUTER, 00152 DHCP_OPTION_BROADCAST 00153 #if LWIP_DHCP_PROVIDE_DNS_SERVERS 00154 , DHCP_OPTION_DNS_SERVER 00155 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ 00156 #if LWIP_DHCP_GET_NTP_SRV 00157 , DHCP_OPTION_NTP 00158 #endif /* LWIP_DHCP_GET_NTP_SRV */ 00159 }; 00160 00161 #ifdef DHCP_GLOBAL_XID 00162 static u32_t xid; 00163 static u8_t xid_initialised; 00164 #endif /* DHCP_GLOBAL_XID */ 00165 00166 #define dhcp_option_given(dhcp, idx) (dhcp_rx_options_given[idx] != 0) 00167 #define dhcp_got_option(dhcp, idx) (dhcp_rx_options_given[idx] = 1) 00168 #define dhcp_clear_option(dhcp, idx) (dhcp_rx_options_given[idx] = 0) 00169 #define dhcp_clear_all_options(dhcp) (memset(dhcp_rx_options_given, 0, sizeof(dhcp_rx_options_given))) 00170 #define dhcp_get_option_value(dhcp, idx) (dhcp_rx_options_val[idx]) 00171 #define dhcp_set_option_value(dhcp, idx, val) (dhcp_rx_options_val[idx] = (val)) 00172 00173 static struct udp_pcb *dhcp_pcb; 00174 static u8_t dhcp_pcb_refcount; 00175 00176 /* DHCP client state machine functions */ 00177 static err_t dhcp_discover(struct netif *netif); 00178 static err_t dhcp_select(struct netif *netif); 00179 static void dhcp_bind(struct netif *netif); 00180 #if DHCP_DOES_ARP_CHECK 00181 static err_t dhcp_decline(struct netif *netif); 00182 #endif /* DHCP_DOES_ARP_CHECK */ 00183 static err_t dhcp_rebind(struct netif *netif); 00184 static err_t dhcp_reboot(struct netif *netif); 00185 static void dhcp_set_state(struct dhcp *dhcp, u8_t new_state); 00186 00187 /* receive, unfold, parse and free incoming messages */ 00188 static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port); 00189 00190 /* set the DHCP timers */ 00191 static void dhcp_timeout(struct netif *netif); 00192 static void dhcp_t1_timeout(struct netif *netif); 00193 static void dhcp_t2_timeout(struct netif *netif); 00194 00195 /* build outgoing messages */ 00196 /* create a DHCP message, fill in common headers */ 00197 static err_t dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type); 00198 /* free a DHCP request */ 00199 static void dhcp_delete_msg(struct dhcp *dhcp); 00200 /* add a DHCP option (type, then length in bytes) */ 00201 static void dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len); 00202 /* add option values */ 00203 static void dhcp_option_byte(struct dhcp *dhcp, u8_t value); 00204 static void dhcp_option_short(struct dhcp *dhcp, u16_t value); 00205 static void dhcp_option_long(struct dhcp *dhcp, u32_t value); 00206 #if LWIP_NETIF_HOSTNAME 00207 static void dhcp_option_hostname(struct dhcp *dhcp, struct netif *netif); 00208 #endif /* LWIP_NETIF_HOSTNAME */ 00209 /* always add the DHCP options trailer to end and pad */ 00210 static void dhcp_option_trailer(struct dhcp *dhcp); 00211 00212 /** Ensure DHCP PCB is allocated and bound */ 00213 static err_t 00214 dhcp_inc_pcb_refcount(void) 00215 { 00216 if (dhcp_pcb_refcount == 0) { 00217 LWIP_ASSERT("dhcp_inc_pcb_refcount(): memory leak", dhcp_pcb == NULL); 00218 00219 /* allocate UDP PCB */ 00220 dhcp_pcb = udp_new(); 00221 00222 if (dhcp_pcb == NULL) { 00223 return ERR_MEM; 00224 } 00225 00226 ip_set_option(dhcp_pcb, SOF_BROADCAST); 00227 00228 /* set up local and remote port for the pcb -> listen on all interfaces on all src/dest IPs */ 00229 udp_bind(dhcp_pcb, IP4_ADDR_ANY, DHCP_CLIENT_PORT); 00230 udp_connect(dhcp_pcb, IP4_ADDR_ANY, DHCP_SERVER_PORT); 00231 udp_recv(dhcp_pcb, dhcp_recv, NULL); 00232 } 00233 00234 dhcp_pcb_refcount++; 00235 00236 return ERR_OK; 00237 } 00238 00239 /** Free DHCP PCB if the last netif stops using it */ 00240 static void 00241 dhcp_dec_pcb_refcount(void) 00242 { 00243 LWIP_ASSERT("dhcp_pcb_refcount(): refcount error", (dhcp_pcb_refcount > 0)); 00244 dhcp_pcb_refcount--; 00245 00246 if (dhcp_pcb_refcount == 0) { 00247 udp_remove(dhcp_pcb); 00248 dhcp_pcb = NULL; 00249 } 00250 } 00251 00252 /** 00253 * Back-off the DHCP client (because of a received NAK response). 00254 * 00255 * Back-off the DHCP client because of a received NAK. Receiving a 00256 * NAK means the client asked for something non-sensible, for 00257 * example when it tries to renew a lease obtained on another network. 00258 * 00259 * We clear any existing set IP address and restart DHCP negotiation 00260 * afresh (as per RFC2131 3.2.3). 00261 * 00262 * @param netif the netif under DHCP control 00263 */ 00264 static void 00265 dhcp_handle_nak(struct netif *netif) 00266 { 00267 struct dhcp *dhcp = netif_dhcp_data(netif); 00268 00269 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_nak(netif=%p) %c%c%"U16_F"\n", 00270 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); 00271 /* Change to a defined state - set this before assigning the address 00272 to ensure the callback can use dhcp_supplied_address() */ 00273 dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF); 00274 /* remove IP address from interface (must no longer be used, as per RFC2131) */ 00275 netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4); 00276 /* We can immediately restart discovery */ 00277 dhcp_discover(netif); 00278 } 00279 00280 #if DHCP_DOES_ARP_CHECK 00281 /** 00282 * Checks if the offered IP address is already in use. 00283 * 00284 * It does so by sending an ARP request for the offered address and 00285 * entering CHECKING state. If no ARP reply is received within a small 00286 * interval, the address is assumed to be free for use by us. 00287 * 00288 * @param netif the netif under DHCP control 00289 */ 00290 static void 00291 dhcp_check(struct netif *netif) 00292 { 00293 struct dhcp *dhcp = netif_dhcp_data(netif); 00294 err_t result; 00295 u16_t msecs; 00296 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_check(netif=%p) %c%c\n", (void *)netif, (s16_t)netif->name[0], 00297 (s16_t)netif->name[1])); 00298 dhcp_set_state(dhcp, DHCP_STATE_CHECKING); 00299 /* create an ARP query for the offered IP address, expecting that no host 00300 responds, as the IP address should not be in use. */ 00301 result = etharp_query(netif, &dhcp->offered_ip_addr, NULL); 00302 if (result != ERR_OK) { 00303 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_check: could not perform ARP query\n")); 00304 } 00305 if (dhcp->tries < 255) { 00306 dhcp->tries++; 00307 } 00308 msecs = 500; 00309 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 00310 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_check(): set request timeout %"U16_F" msecs\n", msecs)); 00311 } 00312 #endif /* DHCP_DOES_ARP_CHECK */ 00313 00314 /** 00315 * Remember the configuration offered by a DHCP server. 00316 * 00317 * @param netif the netif under DHCP control 00318 */ 00319 static void 00320 dhcp_handle_offer(struct netif *netif) 00321 { 00322 struct dhcp *dhcp = netif_dhcp_data(netif); 00323 00324 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_offer(netif=%p) %c%c%"U16_F"\n", 00325 (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); 00326 /* obtain the server address */ 00327 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SERVER_ID)) { 00328 ip_addr_set_ip4_u32(&dhcp->server_ip_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SERVER_ID))); 00329 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): server 0x%08"X32_F"\n", 00330 ip4_addr_get_u32(ip_2_ip4(&dhcp->server_ip_addr)))); 00331 /* remember offered address */ 00332 ip4_addr_copy(dhcp->offered_ip_addr, dhcp->msg_in->yiaddr); 00333 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): offer for 0x%08"X32_F"\n", 00334 ip4_addr_get_u32(&dhcp->offered_ip_addr))); 00335 00336 dhcp_select(netif); 00337 } else { 00338 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 00339 ("dhcp_handle_offer(netif=%p) did not get server ID!\n", (void*)netif)); 00340 } 00341 } 00342 00343 /** 00344 * Select a DHCP server offer out of all offers. 00345 * 00346 * Simply select the first offer received. 00347 * 00348 * @param netif the netif under DHCP control 00349 * @return lwIP specific error (see error.h) 00350 */ 00351 static err_t 00352 dhcp_select(struct netif *netif) 00353 { 00354 struct dhcp *dhcp = netif_dhcp_data(netif); 00355 err_t result; 00356 u16_t msecs; 00357 u8_t i; 00358 00359 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)); 00360 dhcp_set_state(dhcp, DHCP_STATE_REQUESTING); 00361 00362 /* create and initialize the DHCP message header */ 00363 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 00364 if (result == ERR_OK) { 00365 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 00366 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 00367 00368 /* MUST request the offered IP address */ 00369 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 00370 dhcp_option_long(dhcp, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); 00371 00372 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); 00373 dhcp_option_long(dhcp, lwip_ntohl(ip4_addr_get_u32(ip_2_ip4(&dhcp->server_ip_addr)))); 00374 00375 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); 00376 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { 00377 dhcp_option_byte(dhcp, dhcp_discover_request_options[i]); 00378 } 00379 00380 #if LWIP_NETIF_HOSTNAME 00381 dhcp_option_hostname(dhcp, netif); 00382 #endif /* LWIP_NETIF_HOSTNAME */ 00383 00384 dhcp_option_trailer(dhcp); 00385 /* shrink the pbuf to the actual content length */ 00386 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 00387 00388 /* send broadcast to any DHCP server */ 00389 udp_sendto_if_src(dhcp_pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif, IP4_ADDR_ANY); 00390 dhcp_delete_msg(dhcp); 00391 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_select: REQUESTING\n")); 00392 } else { 00393 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_select: could not allocate DHCP request\n")); 00394 } 00395 if (dhcp->tries < 255) { 00396 dhcp->tries++; 00397 } 00398 msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000; 00399 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 00400 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_select(): set request timeout %"U16_F" msecs\n", msecs)); 00401 return result; 00402 } 00403 00404 /** 00405 * The DHCP timer that checks for lease renewal/rebind timeouts. 00406 * Must be called once a minute (see @ref DHCP_COARSE_TIMER_SECS). 00407 */ 00408 void 00409 dhcp_coarse_tmr(void) 00410 { 00411 struct netif *netif = netif_list; 00412 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n")); 00413 /* iterate through all network interfaces */ 00414 while (netif != NULL) { 00415 /* only act on DHCP configured interfaces */ 00416 struct dhcp *dhcp = netif_dhcp_data(netif); 00417 if ((dhcp != NULL) && (dhcp->state != DHCP_STATE_OFF)) { 00418 /* compare lease time to expire timeout */ 00419 if (dhcp->t0_timeout && (++dhcp->lease_used == dhcp->t0_timeout)) { 00420 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t0 timeout\n")); 00421 /* this clients' lease time has expired */ 00422 dhcp_release(netif); 00423 dhcp_discover(netif); 00424 /* timer is active (non zero), and triggers (zeroes) now? */ 00425 } else if (dhcp->t2_rebind_time && (dhcp->t2_rebind_time-- == 1)) { 00426 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t2 timeout\n")); 00427 /* this clients' rebind timeout triggered */ 00428 dhcp_t2_timeout(netif); 00429 /* timer is active (non zero), and triggers (zeroes) now */ 00430 } else if (dhcp->t1_renew_time && (dhcp->t1_renew_time-- == 1)) { 00431 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t1 timeout\n")); 00432 /* this clients' renewal timeout triggered */ 00433 dhcp_t1_timeout(netif); 00434 } 00435 } 00436 /* proceed to next netif */ 00437 netif = netif->next; 00438 } 00439 } 00440 00441 /** 00442 * DHCP transaction timeout handling (this function must be called every 500ms, 00443 * see @ref DHCP_FINE_TIMER_MSECS). 00444 * 00445 * A DHCP server is expected to respond within a short period of time. 00446 * This timer checks whether an outstanding DHCP request is timed out. 00447 */ 00448 void 00449 dhcp_fine_tmr(void) 00450 { 00451 struct netif *netif = netif_list; 00452 /* loop through netif's */ 00453 while (netif != NULL) { 00454 struct dhcp *dhcp = netif_dhcp_data(netif); 00455 /* only act on DHCP configured interfaces */ 00456 if (dhcp != NULL) { 00457 /* timer is active (non zero), and is about to trigger now */ 00458 if (dhcp->request_timeout > 1) { 00459 dhcp->request_timeout--; 00460 } 00461 else if (dhcp->request_timeout == 1) { 00462 dhcp->request_timeout--; 00463 /* { netif->dhcp->request_timeout == 0 } */ 00464 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_fine_tmr(): request timeout\n")); 00465 /* this client's request timeout triggered */ 00466 dhcp_timeout(netif); 00467 } 00468 } 00469 /* proceed to next network interface */ 00470 netif = netif->next; 00471 } 00472 } 00473 00474 /** 00475 * A DHCP negotiation transaction, or ARP request, has timed out. 00476 * 00477 * The timer that was started with the DHCP or ARP request has 00478 * timed out, indicating no response was received in time. 00479 * 00480 * @param netif the netif under DHCP control 00481 */ 00482 static void 00483 dhcp_timeout(struct netif *netif) 00484 { 00485 struct dhcp *dhcp = netif_dhcp_data(netif); 00486 00487 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout()\n")); 00488 /* back-off period has passed, or server selection timed out */ 00489 if ((dhcp->state == DHCP_STATE_BACKING_OFF) || (dhcp->state == DHCP_STATE_SELECTING)) { 00490 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout(): restarting discovery\n")); 00491 dhcp_discover(netif); 00492 /* receiving the requested lease timed out */ 00493 } else if (dhcp->state == DHCP_STATE_REQUESTING) { 00494 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, DHCP request timed out\n")); 00495 if (dhcp->tries <= 5) { 00496 dhcp_select(netif); 00497 } else { 00498 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, releasing, restarting\n")); 00499 dhcp_release(netif); 00500 dhcp_discover(netif); 00501 } 00502 #if DHCP_DOES_ARP_CHECK 00503 /* received no ARP reply for the offered address (which is good) */ 00504 } else if (dhcp->state == DHCP_STATE_CHECKING) { 00505 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): CHECKING, ARP request timed out\n")); 00506 if (dhcp->tries <= 1) { 00507 dhcp_check(netif); 00508 /* no ARP replies on the offered address, 00509 looks like the IP address is indeed free */ 00510 } else { 00511 /* bind the interface to the offered address */ 00512 dhcp_bind(netif); 00513 } 00514 #endif /* DHCP_DOES_ARP_CHECK */ 00515 } else if (dhcp->state == DHCP_STATE_REBOOTING) { 00516 if (dhcp->tries < REBOOT_TRIES) { 00517 dhcp_reboot(netif); 00518 } else { 00519 dhcp_discover(netif); 00520 } 00521 } 00522 } 00523 00524 /** 00525 * The renewal period has timed out. 00526 * 00527 * @param netif the netif under DHCP control 00528 */ 00529 static void 00530 dhcp_t1_timeout(struct netif *netif) 00531 { 00532 struct dhcp *dhcp = netif_dhcp_data(netif); 00533 00534 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_t1_timeout()\n")); 00535 if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_BOUND) || 00536 (dhcp->state == DHCP_STATE_RENEWING)) { 00537 /* just retry to renew - note that the rebind timer (t2) will 00538 * eventually time-out if renew tries fail. */ 00539 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, 00540 ("dhcp_t1_timeout(): must renew\n")); 00541 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state 00542 DHCP_STATE_RENEWING, not DHCP_STATE_BOUND */ 00543 dhcp_renew(netif); 00544 /* Calculate next timeout */ 00545 if (((dhcp->t2_timeout - dhcp->lease_used) / 2) >= ((60 + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS)) 00546 { 00547 dhcp->t1_renew_time = ((dhcp->t2_timeout - dhcp->lease_used) / 2); 00548 } 00549 } 00550 } 00551 00552 /** 00553 * The rebind period has timed out. 00554 * 00555 * @param netif the netif under DHCP control 00556 */ 00557 static void 00558 dhcp_t2_timeout(struct netif *netif) 00559 { 00560 struct dhcp *dhcp = netif_dhcp_data(netif); 00561 00562 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t2_timeout()\n")); 00563 if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_BOUND) || 00564 (dhcp->state == DHCP_STATE_RENEWING) || (dhcp->state == DHCP_STATE_REBINDING)) { 00565 /* just retry to rebind */ 00566 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, 00567 ("dhcp_t2_timeout(): must rebind\n")); 00568 /* This slightly different to RFC2131: DHCPREQUEST will be sent from state 00569 DHCP_STATE_REBINDING, not DHCP_STATE_BOUND */ 00570 dhcp_rebind(netif); 00571 /* Calculate next timeout */ 00572 if (((dhcp->t0_timeout - dhcp->lease_used) / 2) >= ((60 + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS)) 00573 { 00574 dhcp->t2_rebind_time = ((dhcp->t0_timeout - dhcp->lease_used) / 2); 00575 } 00576 } 00577 } 00578 00579 /** 00580 * Handle a DHCP ACK packet 00581 * 00582 * @param netif the netif under DHCP control 00583 */ 00584 static void 00585 dhcp_handle_ack(struct netif *netif) 00586 { 00587 struct dhcp *dhcp = netif_dhcp_data(netif); 00588 00589 #if LWIP_DHCP_PROVIDE_DNS_SERVERS || LWIP_DHCP_GET_NTP_SRV 00590 u8_t n; 00591 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS || LWIP_DHCP_GET_NTP_SRV */ 00592 #if LWIP_DHCP_GET_NTP_SRV 00593 ip4_addr_t ntp_server_addrs[LWIP_DHCP_MAX_NTP_SERVERS]; 00594 #endif 00595 00596 /* clear options we might not get from the ACK */ 00597 ip4_addr_set_zero(&dhcp->offered_sn_mask); 00598 ip4_addr_set_zero(&dhcp->offered_gw_addr); 00599 #if LWIP_DHCP_BOOTP_FILE 00600 ip4_addr_set_zero(&dhcp->offered_si_addr); 00601 #endif /* LWIP_DHCP_BOOTP_FILE */ 00602 00603 /* lease time given? */ 00604 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_LEASE_TIME)) { 00605 /* remember offered lease time */ 00606 dhcp->offered_t0_lease = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_LEASE_TIME); 00607 } 00608 /* renewal period given? */ 00609 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T1)) { 00610 /* remember given renewal period */ 00611 dhcp->offered_t1_renew = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T1); 00612 } else { 00613 /* calculate safe periods for renewal */ 00614 dhcp->offered_t1_renew = dhcp->offered_t0_lease / 2; 00615 } 00616 00617 /* renewal period given? */ 00618 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T2)) { 00619 /* remember given rebind period */ 00620 dhcp->offered_t2_rebind = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T2); 00621 } else { 00622 /* calculate safe periods for rebinding (offered_t0_lease * 0.875 -> 87.5%)*/ 00623 dhcp->offered_t2_rebind = (dhcp->offered_t0_lease * 7U) / 8U; 00624 } 00625 00626 /* (y)our internet address */ 00627 ip4_addr_copy(dhcp->offered_ip_addr, dhcp->msg_in->yiaddr); 00628 00629 #if LWIP_DHCP_BOOTP_FILE 00630 /* copy boot server address, 00631 boot file name copied in dhcp_parse_reply if not overloaded */ 00632 ip4_addr_copy(dhcp->offered_si_addr, dhcp->msg_in->siaddr); 00633 #endif /* LWIP_DHCP_BOOTP_FILE */ 00634 00635 /* subnet mask given? */ 00636 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)) { 00637 /* remember given subnet mask */ 00638 ip4_addr_set_u32(&dhcp->offered_sn_mask, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SUBNET_MASK))); 00639 dhcp->subnet_mask_given = 1; 00640 } else { 00641 dhcp->subnet_mask_given = 0; 00642 } 00643 00644 /* gateway router */ 00645 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_ROUTER)) { 00646 ip4_addr_set_u32(&dhcp->offered_gw_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_ROUTER))); 00647 } 00648 00649 #if LWIP_DHCP_GET_NTP_SRV 00650 /* NTP servers */ 00651 for (n = 0; (n < LWIP_DHCP_MAX_NTP_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_NTP_SERVER + n); n++) { 00652 ip4_addr_set_u32(&ntp_server_addrs[n], lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_NTP_SERVER + n))); 00653 } 00654 dhcp_set_ntp_servers(n, ntp_server_addrs); 00655 #endif /* LWIP_DHCP_GET_NTP_SRV */ 00656 00657 #if LWIP_DHCP_PROVIDE_DNS_SERVERS 00658 /* DNS servers */ 00659 for (n = 0; (n < LWIP_DHCP_PROVIDE_DNS_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n); n++) { 00660 ip_addr_t dns_addr; 00661 ip_addr_set_ip4_u32(&dns_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n))); 00662 dns_setserver(n, &dns_addr); 00663 } 00664 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ 00665 } 00666 00667 /** 00668 * @ingroup dhcp4 00669 * Set a statically allocated struct dhcp to work with. 00670 * Using this prevents dhcp_start to allocate it using mem_malloc. 00671 * 00672 * @param netif the netif for which to set the struct dhcp 00673 * @param dhcp (uninitialised) dhcp struct allocated by the application 00674 */ 00675 void 00676 dhcp_set_struct(struct netif *netif, struct dhcp *dhcp) 00677 { 00678 LWIP_ASSERT("netif != NULL", netif != NULL); 00679 LWIP_ASSERT("dhcp != NULL", dhcp != NULL); 00680 LWIP_ASSERT("netif already has a struct dhcp set", netif_dhcp_data(netif) == NULL); 00681 00682 /* clear data structure */ 00683 memset(dhcp, 0, sizeof(struct dhcp)); 00684 /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */ 00685 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp); 00686 } 00687 00688 /** 00689 * @ingroup dhcp4 00690 * Removes a struct dhcp from a netif. 00691 * 00692 * ATTENTION: Only use this when not using dhcp_set_struct() to allocate the 00693 * struct dhcp since the memory is passed back to the heap. 00694 * 00695 * @param netif the netif from which to remove the struct dhcp 00696 */ 00697 void dhcp_cleanup(struct netif *netif) 00698 { 00699 LWIP_ASSERT("netif != NULL", netif != NULL); 00700 00701 if (netif_dhcp_data(netif) != NULL) { 00702 mem_free(netif_dhcp_data(netif)); 00703 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, NULL); 00704 } 00705 } 00706 00707 /** 00708 * @ingroup dhcp4 00709 * Start DHCP negotiation for a network interface. 00710 * 00711 * If no DHCP client instance was attached to this interface, 00712 * a new client is created first. If a DHCP client instance 00713 * was already present, it restarts negotiation. 00714 * 00715 * @param netif The lwIP network interface 00716 * @return lwIP error code 00717 * - ERR_OK - No error 00718 * - ERR_MEM - Out of memory 00719 */ 00720 err_t 00721 dhcp_start(struct netif *netif) 00722 { 00723 struct dhcp *dhcp; 00724 err_t result; 00725 00726 LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;); 00727 LWIP_ERROR("netif is not up, old style port?", netif_is_up(netif), return ERR_ARG;); 00728 dhcp = netif_dhcp_data(netif); 00729 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)); 00730 00731 /* check MTU of the netif */ 00732 if (netif->mtu < DHCP_MAX_MSG_LEN_MIN_REQUIRED) { 00733 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): Cannot use this netif with DHCP: MTU is too small\n")); 00734 return ERR_MEM; 00735 } 00736 00737 /* no DHCP client attached yet? */ 00738 if (dhcp == NULL) { 00739 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting new DHCP client\n")); 00740 dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp)); 00741 if (dhcp == NULL) { 00742 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n")); 00743 return ERR_MEM; 00744 } 00745 00746 /* store this dhcp client in the netif */ 00747 netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp); 00748 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): allocated dhcp")); 00749 /* already has DHCP client attached */ 00750 } else { 00751 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(): restarting DHCP configuration\n")); 00752 LWIP_ASSERT("pbuf p_out wasn't freed", dhcp->p_out == NULL); 00753 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL ); 00754 00755 if (dhcp->pcb_allocated != 0) { 00756 dhcp_dec_pcb_refcount(); /* free DHCP PCB if not needed any more */ 00757 } 00758 /* dhcp is cleared below, no need to reset flag*/ 00759 } 00760 00761 /* clear data structure */ 00762 memset(dhcp, 0, sizeof(struct dhcp)); 00763 /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */ 00764 00765 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n")); 00766 00767 if (dhcp_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP PCB is allocated */ 00768 return ERR_MEM; 00769 } 00770 dhcp->pcb_allocated = 1; 00771 00772 #if LWIP_DHCP_CHECK_LINK_UP 00773 if (!netif_is_link_up(netif)) { 00774 /* set state INIT and wait for dhcp_network_changed() to call dhcp_discover() */ 00775 dhcp_set_state(dhcp, DHCP_STATE_INIT); 00776 return ERR_OK; 00777 } 00778 #endif /* LWIP_DHCP_CHECK_LINK_UP */ 00779 00780 00781 /* (re)start the DHCP negotiation */ 00782 result = dhcp_discover(netif); 00783 if (result != ERR_OK) { 00784 /* free resources allocated above */ 00785 dhcp_stop(netif); 00786 return ERR_MEM; 00787 } 00788 return result; 00789 } 00790 00791 /** 00792 * @ingroup dhcp4 00793 * Inform a DHCP server of our manual configuration. 00794 * 00795 * This informs DHCP servers of our fixed IP address configuration 00796 * by sending an INFORM message. It does not involve DHCP address 00797 * configuration, it is just here to be nice to the network. 00798 * 00799 * @param netif The lwIP network interface 00800 */ 00801 void 00802 dhcp_inform(struct netif *netif) 00803 { 00804 struct dhcp dhcp; 00805 err_t result = ERR_OK; 00806 00807 LWIP_ERROR("netif != NULL", (netif != NULL), return;); 00808 00809 if (dhcp_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP PCB is allocated */ 00810 return; 00811 } 00812 00813 memset(&dhcp, 0, sizeof(struct dhcp)); 00814 dhcp_set_state(&dhcp, DHCP_STATE_INFORMING); 00815 00816 /* create and initialize the DHCP message header */ 00817 result = dhcp_create_msg(netif, &dhcp, DHCP_INFORM); 00818 if (result == ERR_OK) { 00819 dhcp_option(&dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 00820 dhcp_option_short(&dhcp, DHCP_MAX_MSG_LEN(netif)); 00821 00822 dhcp_option_trailer(&dhcp); 00823 00824 pbuf_realloc(dhcp.p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp.options_out_len); 00825 00826 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n")); 00827 00828 udp_sendto_if(dhcp_pcb, dhcp.p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 00829 00830 dhcp_delete_msg(&dhcp); 00831 } else { 00832 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform: could not allocate DHCP request\n")); 00833 } 00834 00835 dhcp_dec_pcb_refcount(); /* delete DHCP PCB if not needed any more */ 00836 } 00837 00838 /** Handle a possible change in the network configuration. 00839 * 00840 * This enters the REBOOTING state to verify that the currently bound 00841 * address is still valid. 00842 */ 00843 void 00844 dhcp_network_changed(struct netif *netif) 00845 { 00846 struct dhcp *dhcp = netif_dhcp_data(netif); 00847 00848 if (!dhcp) 00849 return; 00850 switch (dhcp->state) { 00851 case DHCP_STATE_REBINDING: 00852 case DHCP_STATE_RENEWING: 00853 case DHCP_STATE_BOUND: 00854 case DHCP_STATE_REBOOTING: 00855 dhcp->tries = 0; 00856 dhcp_reboot(netif); 00857 break; 00858 case DHCP_STATE_OFF: 00859 /* stay off */ 00860 break; 00861 default: 00862 /* INIT/REQUESTING/CHECKING/BACKING_OFF restart with new 'rid' because the 00863 state changes, SELECTING: continue with current 'rid' as we stay in the 00864 same state */ 00865 #if LWIP_DHCP_AUTOIP_COOP 00866 if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { 00867 autoip_stop(netif); 00868 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; 00869 } 00870 #endif /* LWIP_DHCP_AUTOIP_COOP */ 00871 /* ensure we start with short timeouts, even if already discovering */ 00872 dhcp->tries = 0; 00873 dhcp_discover(netif); 00874 break; 00875 } 00876 } 00877 00878 #if DHCP_DOES_ARP_CHECK 00879 /** 00880 * Match an ARP reply with the offered IP address: 00881 * check whether the offered IP address is not in use using ARP 00882 * 00883 * @param netif the network interface on which the reply was received 00884 * @param addr The IP address we received a reply from 00885 */ 00886 void 00887 dhcp_arp_reply(struct netif *netif, const ip4_addr_t *addr) 00888 { 00889 struct dhcp *dhcp; 00890 00891 LWIP_ERROR("netif != NULL", (netif != NULL), return;); 00892 dhcp = netif_dhcp_data(netif); 00893 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_arp_reply()\n")); 00894 /* is a DHCP client doing an ARP check? */ 00895 if ((dhcp != NULL) && (dhcp->state == DHCP_STATE_CHECKING)) { 00896 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_arp_reply(): CHECKING, arp reply for 0x%08"X32_F"\n", 00897 ip4_addr_get_u32(addr))); 00898 /* did a host respond with the address we 00899 were offered by the DHCP server? */ 00900 if (ip4_addr_cmp(addr, &dhcp->offered_ip_addr)) { 00901 /* we will not accept the offered address */ 00902 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING, 00903 ("dhcp_arp_reply(): arp reply matched with offered address, declining\n")); 00904 dhcp_decline(netif); 00905 } 00906 } 00907 } 00908 00909 /** 00910 * Decline an offered lease. 00911 * 00912 * Tell the DHCP server we do not accept the offered address. 00913 * One reason to decline the lease is when we find out the address 00914 * is already in use by another host (through ARP). 00915 * 00916 * @param netif the netif under DHCP control 00917 */ 00918 static err_t 00919 dhcp_decline(struct netif *netif) 00920 { 00921 struct dhcp *dhcp = netif_dhcp_data(netif); 00922 err_t result = ERR_OK; 00923 u16_t msecs; 00924 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline()\n")); 00925 dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF); 00926 /* create and initialize the DHCP message header */ 00927 result = dhcp_create_msg(netif, dhcp, DHCP_DECLINE); 00928 if (result == ERR_OK) { 00929 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 00930 dhcp_option_long(dhcp, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); 00931 00932 dhcp_option_trailer(dhcp); 00933 /* resize pbuf to reflect true size of options */ 00934 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 00935 00936 /* per section 4.4.4, broadcast DECLINE messages */ 00937 udp_sendto_if_src(dhcp_pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif, IP4_ADDR_ANY); 00938 dhcp_delete_msg(dhcp); 00939 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_decline: BACKING OFF\n")); 00940 } else { 00941 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 00942 ("dhcp_decline: could not allocate DHCP request\n")); 00943 } 00944 if (dhcp->tries < 255) { 00945 dhcp->tries++; 00946 } 00947 msecs = 10*1000; 00948 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 00949 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs)); 00950 return result; 00951 } 00952 #endif /* DHCP_DOES_ARP_CHECK */ 00953 00954 00955 /** 00956 * Start the DHCP process, discover a DHCP server. 00957 * 00958 * @param netif the netif under DHCP control 00959 */ 00960 static err_t 00961 dhcp_discover(struct netif *netif) 00962 { 00963 struct dhcp *dhcp = netif_dhcp_data(netif); 00964 err_t result = ERR_OK; 00965 u16_t msecs; 00966 u8_t i; 00967 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover()\n")); 00968 ip4_addr_set_any(&dhcp->offered_ip_addr); 00969 dhcp_set_state(dhcp, DHCP_STATE_SELECTING); 00970 /* create and initialize the DHCP message header */ 00971 result = dhcp_create_msg(netif, dhcp, DHCP_DISCOVER); 00972 if (result == ERR_OK) { 00973 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n")); 00974 00975 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 00976 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 00977 00978 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); 00979 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { 00980 dhcp_option_byte(dhcp, dhcp_discover_request_options[i]); 00981 } 00982 dhcp_option_trailer(dhcp); 00983 00984 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: realloc()ing\n")); 00985 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 00986 00987 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, DHCP_SERVER_PORT)\n")); 00988 udp_sendto_if_src(dhcp_pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif, IP4_ADDR_ANY); 00989 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()ing\n")); 00990 dhcp_delete_msg(dhcp); 00991 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover: SELECTING\n")); 00992 } else { 00993 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_discover: could not allocate DHCP request\n")); 00994 } 00995 if (dhcp->tries < 255) { 00996 dhcp->tries++; 00997 } 00998 #if LWIP_DHCP_AUTOIP_COOP 00999 if (dhcp->tries >= LWIP_DHCP_AUTOIP_COOP_TRIES && dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_OFF) { 01000 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_ON; 01001 autoip_start(netif); 01002 } 01003 #endif /* LWIP_DHCP_AUTOIP_COOP */ 01004 msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000; 01005 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 01006 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs)); 01007 return result; 01008 } 01009 01010 01011 /** 01012 * Bind the interface to the offered IP address. 01013 * 01014 * @param netif network interface to bind to the offered address 01015 */ 01016 static void 01017 dhcp_bind(struct netif *netif) 01018 { 01019 u32_t timeout; 01020 struct dhcp *dhcp; 01021 ip4_addr_t sn_mask, gw_addr; 01022 LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;); 01023 dhcp = netif_dhcp_data(netif); 01024 LWIP_ERROR("dhcp_bind: dhcp != NULL", (dhcp != NULL), return;); 01025 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)); 01026 01027 /* reset time used of lease */ 01028 dhcp->lease_used = 0; 01029 01030 if (dhcp->offered_t0_lease != 0xffffffffUL) { 01031 /* set renewal period timer */ 01032 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t0 renewal timer %"U32_F" secs\n", dhcp->offered_t0_lease)); 01033 timeout = (dhcp->offered_t0_lease + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; 01034 if (timeout > 0xffff) { 01035 timeout = 0xffff; 01036 } 01037 dhcp->t0_timeout = (u16_t)timeout; 01038 if (dhcp->t0_timeout == 0) { 01039 dhcp->t0_timeout = 1; 01040 } 01041 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t0_lease*1000)); 01042 } 01043 01044 /* temporary DHCP lease? */ 01045 if (dhcp->offered_t1_renew != 0xffffffffUL) { 01046 /* set renewal period timer */ 01047 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew)); 01048 timeout = (dhcp->offered_t1_renew + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; 01049 if (timeout > 0xffff) { 01050 timeout = 0xffff; 01051 } 01052 dhcp->t1_timeout = (u16_t)timeout; 01053 if (dhcp->t1_timeout == 0) { 01054 dhcp->t1_timeout = 1; 01055 } 01056 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew*1000)); 01057 dhcp->t1_renew_time = dhcp->t1_timeout; 01058 } 01059 /* set renewal period timer */ 01060 if (dhcp->offered_t2_rebind != 0xffffffffUL) { 01061 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind)); 01062 timeout = (dhcp->offered_t2_rebind + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; 01063 if (timeout > 0xffff) { 01064 timeout = 0xffff; 01065 } 01066 dhcp->t2_timeout = (u16_t)timeout; 01067 if (dhcp->t2_timeout == 0) { 01068 dhcp->t2_timeout = 1; 01069 } 01070 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t2_rebind*1000)); 01071 dhcp->t2_rebind_time = dhcp->t2_timeout; 01072 } 01073 01074 /* If we have sub 1 minute lease, t2 and t1 will kick in at the same time. */ 01075 if ((dhcp->t1_timeout >= dhcp->t2_timeout) && (dhcp->t2_timeout > 0)) { 01076 dhcp->t1_timeout = 0; 01077 } 01078 01079 if (dhcp->subnet_mask_given) { 01080 /* copy offered network mask */ 01081 ip4_addr_copy(sn_mask, dhcp->offered_sn_mask); 01082 } else { 01083 /* subnet mask not given, choose a safe subnet mask given the network class */ 01084 u8_t first_octet = ip4_addr1(&dhcp->offered_ip_addr); 01085 if (first_octet <= 127) { 01086 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xff000000UL)); 01087 } else if (first_octet >= 192) { 01088 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffffff00UL)); 01089 } else { 01090 ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffff0000UL)); 01091 } 01092 } 01093 01094 ip4_addr_copy(gw_addr, dhcp->offered_gw_addr); 01095 /* gateway address not given? */ 01096 if (ip4_addr_isany_val(gw_addr)) { 01097 /* copy network address */ 01098 ip4_addr_get_network(&gw_addr, &dhcp->offered_ip_addr, &sn_mask); 01099 /* use first host address on network as gateway */ 01100 ip4_addr_set_u32(&gw_addr, ip4_addr_get_u32(&gw_addr) | PP_HTONL(0x00000001UL)); 01101 } 01102 01103 #if LWIP_DHCP_AUTOIP_COOP 01104 if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { 01105 autoip_stop(netif); 01106 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; 01107 } 01108 #endif /* LWIP_DHCP_AUTOIP_COOP */ 01109 01110 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): IP: 0x%08"X32_F" SN: 0x%08"X32_F" GW: 0x%08"X32_F"\n", 01111 ip4_addr_get_u32(&dhcp->offered_ip_addr), ip4_addr_get_u32(&sn_mask), ip4_addr_get_u32(&gw_addr))); 01112 /* netif is now bound to DHCP leased address - set this before assigning the address 01113 to ensure the callback can use dhcp_supplied_address() */ 01114 dhcp_set_state(dhcp, DHCP_STATE_BOUND); 01115 01116 netif_set_addr(netif, &dhcp->offered_ip_addr, &sn_mask, &gw_addr); 01117 /* interface is used by routing now that an address is set */ 01118 } 01119 01120 /** 01121 * @ingroup dhcp4 01122 * Renew an existing DHCP lease at the involved DHCP server. 01123 * 01124 * @param netif network interface which must renew its lease 01125 */ 01126 err_t 01127 dhcp_renew(struct netif *netif) 01128 { 01129 struct dhcp *dhcp = netif_dhcp_data(netif); 01130 err_t result; 01131 u16_t msecs; 01132 u8_t i; 01133 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_renew()\n")); 01134 dhcp_set_state(dhcp, DHCP_STATE_RENEWING); 01135 01136 /* create and initialize the DHCP message header */ 01137 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 01138 if (result == ERR_OK) { 01139 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 01140 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 01141 01142 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); 01143 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { 01144 dhcp_option_byte(dhcp, dhcp_discover_request_options[i]); 01145 } 01146 01147 #if LWIP_NETIF_HOSTNAME 01148 dhcp_option_hostname(dhcp, netif); 01149 #endif /* LWIP_NETIF_HOSTNAME */ 01150 01151 /* append DHCP message trailer */ 01152 dhcp_option_trailer(dhcp); 01153 01154 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 01155 01156 udp_sendto_if(dhcp_pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif); 01157 dhcp_delete_msg(dhcp); 01158 01159 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew: RENEWING\n")); 01160 } else { 01161 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_renew: could not allocate DHCP request\n")); 01162 } 01163 if (dhcp->tries < 255) { 01164 dhcp->tries++; 01165 } 01166 /* back-off on retries, but to a maximum of 20 seconds */ 01167 msecs = dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000; 01168 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 01169 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs)); 01170 return result; 01171 } 01172 01173 /** 01174 * Rebind with a DHCP server for an existing DHCP lease. 01175 * 01176 * @param netif network interface which must rebind with a DHCP server 01177 */ 01178 static err_t 01179 dhcp_rebind(struct netif *netif) 01180 { 01181 struct dhcp *dhcp = netif_dhcp_data(netif); 01182 err_t result; 01183 u16_t msecs; 01184 u8_t i; 01185 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n")); 01186 dhcp_set_state(dhcp, DHCP_STATE_REBINDING); 01187 01188 /* create and initialize the DHCP message header */ 01189 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 01190 if (result == ERR_OK) { 01191 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 01192 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); 01193 01194 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); 01195 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { 01196 dhcp_option_byte(dhcp, dhcp_discover_request_options[i]); 01197 } 01198 01199 #if LWIP_NETIF_HOSTNAME 01200 dhcp_option_hostname(dhcp, netif); 01201 #endif /* LWIP_NETIF_HOSTNAME */ 01202 01203 dhcp_option_trailer(dhcp); 01204 01205 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 01206 01207 /* broadcast to server */ 01208 udp_sendto_if(dhcp_pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 01209 dhcp_delete_msg(dhcp); 01210 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n")); 01211 } else { 01212 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_rebind: could not allocate DHCP request\n")); 01213 } 01214 if (dhcp->tries < 255) { 01215 dhcp->tries++; 01216 } 01217 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; 01218 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 01219 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs)); 01220 return result; 01221 } 01222 01223 /** 01224 * Enter REBOOTING state to verify an existing lease 01225 * 01226 * @param netif network interface which must reboot 01227 */ 01228 static err_t 01229 dhcp_reboot(struct netif *netif) 01230 { 01231 struct dhcp *dhcp = netif_dhcp_data(netif); 01232 err_t result; 01233 u16_t msecs; 01234 u8_t i; 01235 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n")); 01236 dhcp_set_state(dhcp, DHCP_STATE_REBOOTING); 01237 01238 /* create and initialize the DHCP message header */ 01239 result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); 01240 if (result == ERR_OK) { 01241 dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); 01242 dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN_MIN_REQUIRED); 01243 01244 dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); 01245 dhcp_option_long(dhcp, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); 01246 01247 dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); 01248 for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { 01249 dhcp_option_byte(dhcp, dhcp_discover_request_options[i]); 01250 } 01251 01252 dhcp_option_trailer(dhcp); 01253 01254 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 01255 01256 /* broadcast to server */ 01257 udp_sendto_if(dhcp_pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); 01258 dhcp_delete_msg(dhcp); 01259 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot: REBOOTING\n")); 01260 } else { 01261 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_reboot: could not allocate DHCP request\n")); 01262 } 01263 if (dhcp->tries < 255) { 01264 dhcp->tries++; 01265 } 01266 msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; 01267 dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; 01268 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot(): set request timeout %"U16_F" msecs\n", msecs)); 01269 return result; 01270 } 01271 01272 01273 /** 01274 * @ingroup dhcp4 01275 * Release a DHCP lease (usually called before @ref dhcp_stop). 01276 * 01277 * @param netif network interface which must release its lease 01278 */ 01279 err_t 01280 dhcp_release(struct netif *netif) 01281 { 01282 struct dhcp *dhcp = netif_dhcp_data(netif); 01283 err_t result; 01284 ip_addr_t server_ip_addr; 01285 u8_t is_dhcp_supplied_address; 01286 01287 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release()\n")); 01288 if (dhcp == NULL) { 01289 return ERR_ARG; 01290 } 01291 ip_addr_copy(server_ip_addr, dhcp->server_ip_addr); 01292 01293 is_dhcp_supplied_address = dhcp_supplied_address(netif); 01294 01295 /* idle DHCP client */ 01296 dhcp_set_state(dhcp, DHCP_STATE_OFF); 01297 /* clean old DHCP offer */ 01298 ip_addr_set_zero_ip4(&dhcp->server_ip_addr); 01299 ip4_addr_set_zero(&dhcp->offered_ip_addr); 01300 ip4_addr_set_zero(&dhcp->offered_sn_mask); 01301 ip4_addr_set_zero(&dhcp->offered_gw_addr); 01302 #if LWIP_DHCP_BOOTP_FILE 01303 ip4_addr_set_zero(&dhcp->offered_si_addr); 01304 #endif /* LWIP_DHCP_BOOTP_FILE */ 01305 dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0; 01306 dhcp->t1_renew_time = dhcp->t2_rebind_time = dhcp->lease_used = dhcp->t0_timeout = 0; 01307 01308 if (!is_dhcp_supplied_address) { 01309 /* don't issue release message when address is not dhcp-assigned */ 01310 return ERR_OK; 01311 } 01312 01313 /* create and initialize the DHCP message header */ 01314 result = dhcp_create_msg(netif, dhcp, DHCP_RELEASE); 01315 if (result == ERR_OK) { 01316 dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); 01317 dhcp_option_long(dhcp, lwip_ntohl(ip4_addr_get_u32(ip_2_ip4(&server_ip_addr)))); 01318 01319 dhcp_option_trailer(dhcp); 01320 01321 pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); 01322 01323 udp_sendto_if(dhcp_pcb, dhcp->p_out, &server_ip_addr, DHCP_SERVER_PORT, netif); 01324 dhcp_delete_msg(dhcp); 01325 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_STATE_OFF\n")); 01326 } else { 01327 /* sending release failed, but that's not a problem since the correct behaviour of dhcp does not rely on release */ 01328 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n")); 01329 } 01330 /* remove IP address from interface (prevents routing from selecting this interface) */ 01331 netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4); 01332 01333 return result; 01334 } 01335 01336 /** 01337 * @ingroup dhcp4 01338 * Remove the DHCP client from the interface. 01339 * 01340 * @param netif The network interface to stop DHCP on 01341 */ 01342 void 01343 dhcp_stop(struct netif *netif) 01344 { 01345 struct dhcp *dhcp; 01346 LWIP_ERROR("dhcp_stop: netif != NULL", (netif != NULL), return;); 01347 dhcp = netif_dhcp_data(netif); 01348 01349 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_stop()\n")); 01350 /* netif is DHCP configured? */ 01351 if (dhcp != NULL) { 01352 #if LWIP_DHCP_AUTOIP_COOP 01353 if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { 01354 autoip_stop(netif); 01355 dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; 01356 } 01357 #endif /* LWIP_DHCP_AUTOIP_COOP */ 01358 01359 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL); 01360 dhcp_set_state(dhcp, DHCP_STATE_OFF); 01361 01362 if (dhcp->pcb_allocated != 0) { 01363 dhcp_dec_pcb_refcount(); /* free DHCP PCB if not needed any more */ 01364 dhcp->pcb_allocated = 0; 01365 } 01366 } 01367 } 01368 01369 /* 01370 * Set the DHCP state of a DHCP client. 01371 * 01372 * If the state changed, reset the number of tries. 01373 */ 01374 static void 01375 dhcp_set_state(struct dhcp *dhcp, u8_t new_state) 01376 { 01377 if (new_state != dhcp->state) { 01378 dhcp->state = new_state; 01379 dhcp->tries = 0; 01380 dhcp->request_timeout = 0; 01381 } 01382 } 01383 01384 /* 01385 * Concatenate an option type and length field to the outgoing 01386 * DHCP message. 01387 * 01388 */ 01389 static void 01390 dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len) 01391 { 01392 LWIP_ASSERT("dhcp_option: dhcp->options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN); 01393 dhcp->msg_out->options[dhcp->options_out_len++] = option_type; 01394 dhcp->msg_out->options[dhcp->options_out_len++] = option_len; 01395 } 01396 /* 01397 * Concatenate a single byte to the outgoing DHCP message. 01398 * 01399 */ 01400 static void 01401 dhcp_option_byte(struct dhcp *dhcp, u8_t value) 01402 { 01403 LWIP_ASSERT("dhcp_option_byte: dhcp->options_out_len < DHCP_OPTIONS_LEN", dhcp->options_out_len < DHCP_OPTIONS_LEN); 01404 dhcp->msg_out->options[dhcp->options_out_len++] = value; 01405 } 01406 01407 static void 01408 dhcp_option_short(struct dhcp *dhcp, u16_t value) 01409 { 01410 LWIP_ASSERT("dhcp_option_short: dhcp->options_out_len + 2 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U <= DHCP_OPTIONS_LEN); 01411 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff00U) >> 8); 01412 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t) (value & 0x00ffU); 01413 } 01414 01415 static void 01416 dhcp_option_long(struct dhcp *dhcp, u32_t value) 01417 { 01418 LWIP_ASSERT("dhcp_option_long: dhcp->options_out_len + 4 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 4U <= DHCP_OPTIONS_LEN); 01419 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24); 01420 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16); 01421 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8); 01422 dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x000000ffUL)); 01423 } 01424 01425 #if LWIP_NETIF_HOSTNAME 01426 static void 01427 dhcp_option_hostname(struct dhcp *dhcp, struct netif *netif) 01428 { 01429 if (netif->hostname != NULL) { 01430 size_t namelen = strlen(netif->hostname); 01431 if (namelen > 0) { 01432 size_t len; 01433 const char *p = netif->hostname; 01434 /* Shrink len to available bytes (need 2 bytes for OPTION_HOSTNAME 01435 and 1 byte for trailer) */ 01436 size_t available = DHCP_OPTIONS_LEN - dhcp->options_out_len - 3; 01437 LWIP_ASSERT("DHCP: hostname is too long!", namelen <= available); 01438 len = LWIP_MIN(namelen, available); 01439 LWIP_ASSERT("DHCP: hostname is too long!", len <= 0xFF); 01440 dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, (u8_t)len); 01441 while (len--) { 01442 dhcp_option_byte(dhcp, *p++); 01443 } 01444 } 01445 } 01446 } 01447 #endif /* LWIP_NETIF_HOSTNAME */ 01448 01449 /** 01450 * Extract the DHCP message and the DHCP options. 01451 * 01452 * Extract the DHCP message and the DHCP options, each into a contiguous 01453 * piece of memory. As a DHCP message is variable sized by its options, 01454 * and also allows overriding some fields for options, the easy approach 01455 * is to first unfold the options into a contiguous piece of memory, and 01456 * use that further on. 01457 * 01458 */ 01459 static err_t 01460 dhcp_parse_reply(struct dhcp *dhcp, struct pbuf *p) 01461 { 01462 u8_t *options; 01463 u16_t offset; 01464 u16_t offset_max; 01465 u16_t options_idx; 01466 u16_t options_idx_max; 01467 struct pbuf *q; 01468 int parse_file_as_options = 0; 01469 int parse_sname_as_options = 0; 01470 01471 /* clear received options */ 01472 dhcp_clear_all_options(dhcp); 01473 /* check that beginning of dhcp_msg (up to and including chaddr) is in first pbuf */ 01474 if (p->len < DHCP_SNAME_OFS) { 01475 return ERR_BUF; 01476 } 01477 dhcp->msg_in = (struct dhcp_msg *)p->payload; 01478 #if LWIP_DHCP_BOOTP_FILE 01479 /* clear boot file name */ 01480 dhcp->boot_file_name[0] = 0; 01481 #endif /* LWIP_DHCP_BOOTP_FILE */ 01482 01483 /* parse options */ 01484 01485 /* start with options field */ 01486 options_idx = DHCP_OPTIONS_OFS; 01487 /* parse options to the end of the received packet */ 01488 options_idx_max = p->tot_len; 01489 again: 01490 q = p; 01491 while ((q != NULL) && (options_idx >= q->len)) { 01492 options_idx -= q->len; 01493 options_idx_max -= q->len; 01494 q = q->next; 01495 } 01496 if (q == NULL) { 01497 return ERR_BUF; 01498 } 01499 offset = options_idx; 01500 offset_max = options_idx_max; 01501 options = (u8_t*)q->payload; 01502 /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */ 01503 while ((q != NULL) && (options[offset] != DHCP_OPTION_END) && (offset < offset_max)) { 01504 u8_t op = options[offset]; 01505 u8_t len; 01506 u8_t decode_len = 0; 01507 int decode_idx = -1; 01508 u16_t val_offset = offset + 2; 01509 /* len byte might be in the next pbuf */ 01510 if ((offset + 1) < q->len) { 01511 len = options[offset + 1]; 01512 } else { 01513 len = (q->next != NULL ? ((u8_t*)q->next->payload)[0] : 0); 01514 } 01515 /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F, msg_offset, q->len)); */ 01516 decode_len = len; 01517 switch(op) { 01518 /* case(DHCP_OPTION_END): handled above */ 01519 case(DHCP_OPTION_PAD): 01520 /* special option: no len encoded */ 01521 decode_len = len = 0; 01522 /* will be increased below */ 01523 offset--; 01524 break; 01525 case(DHCP_OPTION_SUBNET_MASK): 01526 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); 01527 decode_idx = DHCP_OPTION_IDX_SUBNET_MASK; 01528 break; 01529 case(DHCP_OPTION_ROUTER): 01530 decode_len = 4; /* only copy the first given router */ 01531 LWIP_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;); 01532 decode_idx = DHCP_OPTION_IDX_ROUTER; 01533 break; 01534 #if LWIP_DHCP_PROVIDE_DNS_SERVERS 01535 case(DHCP_OPTION_DNS_SERVER): 01536 /* special case: there might be more than one server */ 01537 LWIP_ERROR("len %% 4 == 0", len % 4 == 0, return ERR_VAL;); 01538 /* limit number of DNS servers */ 01539 decode_len = LWIP_MIN(len, 4 * DNS_MAX_SERVERS); 01540 LWIP_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;); 01541 decode_idx = DHCP_OPTION_IDX_DNS_SERVER; 01542 break; 01543 #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ 01544 case(DHCP_OPTION_LEASE_TIME): 01545 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); 01546 decode_idx = DHCP_OPTION_IDX_LEASE_TIME; 01547 break; 01548 #if LWIP_DHCP_GET_NTP_SRV 01549 case(DHCP_OPTION_NTP): 01550 /* special case: there might be more than one server */ 01551 LWIP_ERROR("len %% 4 == 0", len % 4 == 0, return ERR_VAL;); 01552 /* limit number of NTP servers */ 01553 decode_len = LWIP_MIN(len, 4 * LWIP_DHCP_MAX_NTP_SERVERS); 01554 LWIP_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;); 01555 decode_idx = DHCP_OPTION_IDX_NTP_SERVER; 01556 break; 01557 #endif /* LWIP_DHCP_GET_NTP_SRV*/ 01558 case(DHCP_OPTION_OVERLOAD): 01559 LWIP_ERROR("len == 1", len == 1, return ERR_VAL;); 01560 /* decode overload only in options, not in file/sname: invalid packet */ 01561 LWIP_ERROR("overload in file/sname", options_idx == DHCP_OPTIONS_OFS, return ERR_VAL;); 01562 decode_idx = DHCP_OPTION_IDX_OVERLOAD; 01563 break; 01564 case(DHCP_OPTION_MESSAGE_TYPE): 01565 LWIP_ERROR("len == 1", len == 1, return ERR_VAL;); 01566 decode_idx = DHCP_OPTION_IDX_MSG_TYPE; 01567 break; 01568 case(DHCP_OPTION_SERVER_ID): 01569 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); 01570 decode_idx = DHCP_OPTION_IDX_SERVER_ID; 01571 break; 01572 case(DHCP_OPTION_T1): 01573 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); 01574 decode_idx = DHCP_OPTION_IDX_T1; 01575 break; 01576 case(DHCP_OPTION_T2): 01577 LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); 01578 decode_idx = DHCP_OPTION_IDX_T2; 01579 break; 01580 default: 01581 decode_len = 0; 01582 LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", (u16_t)op)); 01583 break; 01584 } 01585 offset += len + 2; 01586 if (decode_len > 0) { 01587 u32_t value = 0; 01588 u16_t copy_len; 01589 decode_next: 01590 LWIP_ASSERT("check decode_idx", decode_idx >= 0 && decode_idx < DHCP_OPTION_IDX_MAX); 01591 if (!dhcp_option_given(dhcp, decode_idx)) { 01592 copy_len = LWIP_MIN(decode_len, 4); 01593 if (pbuf_copy_partial(q, &value, copy_len, val_offset) != copy_len) { 01594 return ERR_BUF; 01595 } 01596 if (decode_len > 4) { 01597 /* decode more than one u32_t */ 01598 LWIP_ERROR("decode_len %% 4 == 0", decode_len % 4 == 0, return ERR_VAL;); 01599 dhcp_got_option(dhcp, decode_idx); 01600 dhcp_set_option_value(dhcp, decode_idx, lwip_htonl(value)); 01601 decode_len -= 4; 01602 val_offset += 4; 01603 decode_idx++; 01604 goto decode_next; 01605 } else if (decode_len == 4) { 01606 value = lwip_ntohl(value); 01607 } else { 01608 LWIP_ERROR("invalid decode_len", decode_len == 1, return ERR_VAL;); 01609 value = ((u8_t*)&value)[0]; 01610 } 01611 dhcp_got_option(dhcp, decode_idx); 01612 dhcp_set_option_value(dhcp, decode_idx, value); 01613 } 01614 } 01615 if (offset >= q->len) { 01616 offset -= q->len; 01617 offset_max -= q->len; 01618 if ((offset < offset_max) && offset_max) { 01619 q = q->next; 01620 LWIP_ASSERT("next pbuf was null", q); 01621 options = (u8_t*)q->payload; 01622 } else { 01623 /* We've run out of bytes, probably no end marker. Don't proceed. */ 01624 break; 01625 } 01626 } 01627 } 01628 /* is this an overloaded message? */ 01629 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_OVERLOAD)) { 01630 u32_t overload = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_OVERLOAD); 01631 dhcp_clear_option(dhcp, DHCP_OPTION_IDX_OVERLOAD); 01632 if (overload == DHCP_OVERLOAD_FILE) { 01633 parse_file_as_options = 1; 01634 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded file field\n")); 01635 } else if (overload == DHCP_OVERLOAD_SNAME) { 01636 parse_sname_as_options = 1; 01637 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname field\n")); 01638 } else if (overload == DHCP_OVERLOAD_SNAME_FILE) { 01639 parse_sname_as_options = 1; 01640 parse_file_as_options = 1; 01641 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname and file field\n")); 01642 } else { 01643 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("invalid overload option: %d\n", (int)overload)); 01644 } 01645 #if LWIP_DHCP_BOOTP_FILE 01646 if (!parse_file_as_options) { 01647 /* only do this for ACK messages */ 01648 if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) && 01649 (dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK)) 01650 /* copy bootp file name, don't care for sname (server hostname) */ 01651 if (pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS) != (DHCP_FILE_LEN-1)) { 01652 return ERR_BUF; 01653 } 01654 /* make sure the string is really NULL-terminated */ 01655 dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0; 01656 } 01657 #endif /* LWIP_DHCP_BOOTP_FILE */ 01658 } 01659 if (parse_file_as_options) { 01660 /* if both are overloaded, parse file first and then sname (RFC 2131 ch. 4.1) */ 01661 parse_file_as_options = 0; 01662 options_idx = DHCP_FILE_OFS; 01663 options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN; 01664 goto again; 01665 } else if (parse_sname_as_options) { 01666 parse_sname_as_options = 0; 01667 options_idx = DHCP_SNAME_OFS; 01668 options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN; 01669 goto again; 01670 } 01671 return ERR_OK; 01672 } 01673 01674 /** 01675 * If an incoming DHCP message is in response to us, then trigger the state machine 01676 */ 01677 static void 01678 dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port) 01679 { 01680 struct netif *netif = ip_current_input_netif(); 01681 struct dhcp *dhcp = netif_dhcp_data(netif); 01682 struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload; 01683 u8_t msg_type; 01684 u8_t i; 01685 01686 LWIP_UNUSED_ARG(arg); 01687 01688 /* Caught DHCP message from netif that does not have DHCP enabled? -> not interested */ 01689 if ((dhcp == NULL) || (dhcp->pcb_allocated == 0)) { 01690 goto free_pbuf_and_return; 01691 } 01692 01693 LWIP_ASSERT("invalid server address type", IP_IS_V4(addr)); 01694 01695 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, 01696 ip4_addr1_16(ip_2_ip4(addr)), ip4_addr2_16(ip_2_ip4(addr)), ip4_addr3_16(ip_2_ip4(addr)), ip4_addr4_16(ip_2_ip4(addr)), port)); 01697 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len)); 01698 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len)); 01699 /* prevent warnings about unused arguments */ 01700 LWIP_UNUSED_ARG(pcb); 01701 LWIP_UNUSED_ARG(addr); 01702 LWIP_UNUSED_ARG(port); 01703 01704 LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL); 01705 01706 if (p->len < DHCP_MIN_REPLY_LEN) { 01707 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP reply message or pbuf too short\n")); 01708 goto free_pbuf_and_return; 01709 } 01710 01711 if (reply_msg->op != DHCP_BOOTREPLY) { 01712 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)); 01713 goto free_pbuf_and_return; 01714 } 01715 /* iterate through hardware address and match against DHCP message */ 01716 for (i = 0; i < netif->hwaddr_len && i < NETIF_MAX_HWADDR_LEN && i < DHCP_CHADDR_LEN; i++) { 01717 if (netif->hwaddr[i] != reply_msg->chaddr[i]) { 01718 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, 01719 ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n", 01720 (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i])); 01721 goto free_pbuf_and_return; 01722 } 01723 } 01724 /* match transaction ID against what we expected */ 01725 if (lwip_ntohl(reply_msg->xid) != dhcp->xid) { 01726 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, 01727 ("transaction id mismatch reply_msg->xid(%"X32_F")!=dhcp->xid(%"X32_F")\n",lwip_ntohl(reply_msg->xid),dhcp->xid)); 01728 goto free_pbuf_and_return; 01729 } 01730 /* option fields could be unfold? */ 01731 if (dhcp_parse_reply(dhcp, p) != ERR_OK) { 01732 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 01733 ("problem unfolding DHCP message - too short on memory?\n")); 01734 goto free_pbuf_and_return; 01735 } 01736 01737 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n")); 01738 /* obtain pointer to DHCP message type */ 01739 if (!dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE)) { 01740 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP_OPTION_MESSAGE_TYPE option not found\n")); 01741 goto free_pbuf_and_return; 01742 } 01743 01744 /* read DHCP message type */ 01745 msg_type = (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE); 01746 /* message type is DHCP ACK? */ 01747 if (msg_type == DHCP_ACK) { 01748 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_ACK received\n")); 01749 /* in requesting state? */ 01750 if (dhcp->state == DHCP_STATE_REQUESTING) { 01751 dhcp_handle_ack(netif); 01752 #if DHCP_DOES_ARP_CHECK 01753 if ((netif->flags & NETIF_FLAG_ETHARP) != 0) { 01754 /* check if the acknowledged lease address is already in use */ 01755 dhcp_check(netif); 01756 } else { 01757 /* bind interface to the acknowledged lease address */ 01758 dhcp_bind(netif); 01759 } 01760 #else 01761 /* bind interface to the acknowledged lease address */ 01762 dhcp_bind(netif); 01763 #endif 01764 } 01765 /* already bound to the given lease address? */ 01766 else if ((dhcp->state == DHCP_STATE_REBOOTING) || (dhcp->state == DHCP_STATE_REBINDING) || 01767 (dhcp->state == DHCP_STATE_RENEWING)) { 01768 dhcp_handle_ack(netif); 01769 dhcp_bind(netif); 01770 } 01771 } 01772 /* received a DHCP_NAK in appropriate state? */ 01773 else if ((msg_type == DHCP_NAK) && 01774 ((dhcp->state == DHCP_STATE_REBOOTING) || (dhcp->state == DHCP_STATE_REQUESTING) || 01775 (dhcp->state == DHCP_STATE_REBINDING) || (dhcp->state == DHCP_STATE_RENEWING ))) { 01776 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_NAK received\n")); 01777 dhcp_handle_nak(netif); 01778 } 01779 /* received a DHCP_OFFER in DHCP_STATE_SELECTING state? */ 01780 else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_STATE_SELECTING)) { 01781 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_OFFER received in DHCP_STATE_SELECTING state\n")); 01782 dhcp->request_timeout = 0; 01783 /* remember offered lease */ 01784 dhcp_handle_offer(netif); 01785 } 01786 01787 free_pbuf_and_return: 01788 if (dhcp != NULL) { 01789 dhcp->msg_in = NULL; 01790 } 01791 pbuf_free(p); 01792 } 01793 01794 /** 01795 * Create a DHCP request, fill in common headers 01796 * 01797 * @param netif the netif under DHCP control 01798 * @param dhcp dhcp control struct 01799 * @param message_type message type of the request 01800 */ 01801 static err_t 01802 dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type) 01803 { 01804 u16_t i; 01805 #ifndef DHCP_GLOBAL_XID 01806 /** default global transaction identifier starting value (easy to match 01807 * with a packet analyser). We simply increment for each new request. 01808 * Predefine DHCP_GLOBAL_XID to a better value or a function call to generate one 01809 * at runtime, any supporting function prototypes can be defined in DHCP_GLOBAL_XID_HEADER */ 01810 #if DHCP_CREATE_RAND_XID && defined(LWIP_RAND) 01811 static u32_t xid; 01812 #else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ 01813 static u32_t xid = 0xABCD0000; 01814 #endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ 01815 #else 01816 if (!xid_initialised) { 01817 xid = DHCP_GLOBAL_XID; 01818 xid_initialised = !xid_initialised; 01819 } 01820 #endif 01821 LWIP_ERROR("dhcp_create_msg: netif != NULL", (netif != NULL), return ERR_ARG;); 01822 LWIP_ERROR("dhcp_create_msg: dhcp != NULL", (dhcp != NULL), return ERR_VAL;); 01823 LWIP_ASSERT("dhcp_create_msg: dhcp->p_out == NULL", dhcp->p_out == NULL); 01824 LWIP_ASSERT("dhcp_create_msg: dhcp->msg_out == NULL", dhcp->msg_out == NULL); 01825 dhcp->p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM); 01826 if (dhcp->p_out == NULL) { 01827 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, 01828 ("dhcp_create_msg(): could not allocate pbuf\n")); 01829 return ERR_MEM; 01830 } 01831 LWIP_ASSERT("dhcp_create_msg: check that first pbuf can hold struct dhcp_msg", 01832 (dhcp->p_out->len >= sizeof(struct dhcp_msg))); 01833 01834 /* DHCP_REQUEST should reuse 'xid' from DHCPOFFER */ 01835 if (message_type != DHCP_REQUEST) { 01836 /* reuse transaction identifier in retransmissions */ 01837 if (dhcp->tries == 0) { 01838 #if DHCP_CREATE_RAND_XID && defined(LWIP_RAND) 01839 xid = LWIP_RAND(); 01840 #else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ 01841 xid++; 01842 #endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ 01843 } 01844 dhcp->xid = xid; 01845 } 01846 LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, 01847 ("transaction id xid(%"X32_F")\n", xid)); 01848 01849 dhcp->msg_out = (struct dhcp_msg *)dhcp->p_out->payload; 01850 01851 dhcp->msg_out->op = DHCP_BOOTREQUEST; 01852 /* @todo: make link layer independent */ 01853 dhcp->msg_out->htype = DHCP_HTYPE_ETH; 01854 dhcp->msg_out->hlen = netif->hwaddr_len; 01855 dhcp->msg_out->hops = 0; 01856 dhcp->msg_out->xid = lwip_htonl(dhcp->xid); 01857 dhcp->msg_out->secs = 0; 01858 /* we don't need the broadcast flag since we can receive unicast traffic 01859 before being fully configured! */ 01860 dhcp->msg_out->flags = 0; 01861 ip4_addr_set_zero(&dhcp->msg_out->ciaddr); 01862 /* set ciaddr to netif->ip_addr based on message_type and state */ 01863 if ((message_type == DHCP_INFORM) || (message_type == DHCP_DECLINE) || (message_type == DHCP_RELEASE) || 01864 ((message_type == DHCP_REQUEST) && /* DHCP_STATE_BOUND not used for sending! */ 01865 ((dhcp->state== DHCP_STATE_RENEWING) || dhcp->state== DHCP_STATE_REBINDING))) { 01866 ip4_addr_copy(dhcp->msg_out->ciaddr, *netif_ip4_addr(netif)); 01867 } 01868 ip4_addr_set_zero(&dhcp->msg_out->yiaddr); 01869 ip4_addr_set_zero(&dhcp->msg_out->siaddr); 01870 ip4_addr_set_zero(&dhcp->msg_out->giaddr); 01871 for (i = 0; i < DHCP_CHADDR_LEN; i++) { 01872 /* copy netif hardware address, pad with zeroes */ 01873 dhcp->msg_out->chaddr[i] = (i < netif->hwaddr_len && i < NETIF_MAX_HWADDR_LEN) ? netif->hwaddr[i] : 0/* pad byte*/; 01874 } 01875 for (i = 0; i < DHCP_SNAME_LEN; i++) { 01876 dhcp->msg_out->sname[i] = 0; 01877 } 01878 for (i = 0; i < DHCP_FILE_LEN; i++) { 01879 dhcp->msg_out->file[i] = 0; 01880 } 01881 dhcp->msg_out->cookie = PP_HTONL(DHCP_MAGIC_COOKIE); 01882 dhcp->options_out_len = 0; 01883 /* fill options field with an incrementing array (for debugging purposes) */ 01884 for (i = 0; i < DHCP_OPTIONS_LEN; i++) { 01885 dhcp->msg_out->options[i] = (u8_t)i; /* for debugging only, no matter if truncated */ 01886 } 01887 /* Add option MESSAGE_TYPE */ 01888 dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); 01889 dhcp_option_byte(dhcp, message_type); 01890 return ERR_OK; 01891 } 01892 01893 /** 01894 * Free previously allocated memory used to send a DHCP request. 01895 * 01896 * @param dhcp the dhcp struct to free the request from 01897 */ 01898 static void 01899 dhcp_delete_msg(struct dhcp *dhcp) 01900 { 01901 LWIP_ERROR("dhcp_delete_msg: dhcp != NULL", (dhcp != NULL), return;); 01902 LWIP_ASSERT("dhcp_delete_msg: dhcp->p_out != NULL", dhcp->p_out != NULL); 01903 LWIP_ASSERT("dhcp_delete_msg: dhcp->msg_out != NULL", dhcp->msg_out != NULL); 01904 if (dhcp->p_out != NULL) { 01905 pbuf_free(dhcp->p_out); 01906 } 01907 dhcp->p_out = NULL; 01908 dhcp->msg_out = NULL; 01909 } 01910 01911 /** 01912 * Add a DHCP message trailer 01913 * 01914 * Adds the END option to the DHCP message, and if 01915 * necessary, up to three padding bytes. 01916 * 01917 * @param dhcp DHCP state structure 01918 */ 01919 static void 01920 dhcp_option_trailer(struct dhcp *dhcp) 01921 { 01922 LWIP_ERROR("dhcp_option_trailer: dhcp != NULL", (dhcp != NULL), return;); 01923 LWIP_ASSERT("dhcp_option_trailer: dhcp->msg_out != NULL\n", dhcp->msg_out != NULL); 01924 LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN); 01925 dhcp->msg_out->options[dhcp->options_out_len++] = DHCP_OPTION_END; 01926 /* packet is too small, or not 4 byte aligned? */ 01927 while (((dhcp->options_out_len < DHCP_MIN_OPTIONS_LEN) || (dhcp->options_out_len & 3)) && 01928 (dhcp->options_out_len < DHCP_OPTIONS_LEN)) { 01929 /* add a fill/padding byte */ 01930 dhcp->msg_out->options[dhcp->options_out_len++] = 0; 01931 } 01932 } 01933 01934 /** check if DHCP supplied netif->ip_addr 01935 * 01936 * @param netif the netif to check 01937 * @return 1 if DHCP supplied netif->ip_addr (states BOUND or RENEWING), 01938 * 0 otherwise 01939 */ 01940 u8_t 01941 dhcp_supplied_address(const struct netif *netif) 01942 { 01943 if ((netif != NULL) && (netif_dhcp_data(netif) != NULL)) { 01944 struct dhcp* dhcp = netif_dhcp_data(netif); 01945 return (dhcp->state == DHCP_STATE_BOUND) || (dhcp->state == DHCP_STATE_RENEWING); 01946 } 01947 return 0; 01948 } 01949 01950 #endif /* LWIP_IPV4 && LWIP_DHCP */
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