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