git.sur5r.net Git - freertos/blob - FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/FreeRTOS_DHCP.c

   1 /*\r
   2  * FreeRTOS+TCP V2.0.0\r
   3  * Copyright (C) 2017 Amazon.com, Inc. or its affiliates.  All Rights Reserved.\r
   4  *\r
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy of\r
   6  * this software and associated documentation files (the "Software"), to deal in\r
   7  * the Software without restriction, including without limitation the rights to\r
   8  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of\r
   9  * the Software, and to permit persons to whom the Software is furnished to do so,\r
  10  * subject to the following conditions:\r
  11  *\r
  12  * The above copyright notice and this permission notice shall be included in all\r
  13  * copies or substantial portions of the Software. If you wish to use our Amazon\r
  14  * FreeRTOS name, please do so in a fair use way that does not cause confusion.\r
  15  *\r
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\r
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS\r
  18  * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR\r
  19  * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER\r
  20  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN\r
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.\r
  22  *\r
  23  * http://www.FreeRTOS.org\r
  24  * http://aws.amazon.com/freertos\r
  25  *\r
  26  * 1 tab == 4 spaces!\r
  27  */\r
  28 \r
  29 /* Standard includes. */\r
  30 #include <stdint.h>\r
  31 \r
  32 /* FreeRTOS includes. */\r
  33 #include "FreeRTOS.h"\r
  34 #include "task.h"\r
  35 #include "semphr.h"\r
  36 \r
  37 /* FreeRTOS+TCP includes. */\r
  38 #include "FreeRTOS_IP.h"\r
  39 #include "FreeRTOS_Sockets.h"\r
  40 #include "FreeRTOS_IP_Private.h"\r
  41 #include "FreeRTOS_UDP_IP.h"\r
  42 #include "FreeRTOS_TCP_IP.h"\r
  43 #include "FreeRTOS_DHCP.h"\r
  44 #include "FreeRTOS_ARP.h"\r
  45 #include "NetworkInterface.h"\r
  46 #include "NetworkBufferManagement.h"\r
  47 \r
  48 /* Exclude the entire file if DHCP is not enabled. */\r
  49 #if( ipconfigUSE_DHCP != 0 )\r
  50 \r
  51 #if ( ipconfigUSE_DHCP != 0 ) && ( ipconfigNETWORK_MTU < 586u )\r
  52         /* DHCP must be able to receive an options field of 312 bytes, the fixed\r
  53         part of the DHCP packet is 240 bytes, and the IP/UDP headers take 28 bytes. */\r
  54         #error ipconfigNETWORK_MTU needs to be at least 586 to use DHCP\r
  55 #endif\r
  56 \r
  57 /* Parameter widths in the DHCP packet. */\r
  58 #define dhcpCLIENT_HARDWARE_ADDRESS_LENGTH              16\r
  59 #define dhcpSERVER_HOST_NAME_LENGTH                             64\r
  60 #define dhcpBOOT_FILE_NAME_LENGTH                               128\r
  61 \r
  62 /* Timer parameters */\r
  63 #ifndef dhcpINITIAL_DHCP_TX_PERIOD\r
  64         #define dhcpINITIAL_TIMER_PERIOD                        ( pdMS_TO_TICKS( 250 ) )\r
  65         #define dhcpINITIAL_DHCP_TX_PERIOD                      ( pdMS_TO_TICKS( 5000 ) )\r
  66 #endif\r
  67 \r
  68 /* Codes of interest found in the DHCP options field. */\r
  69 #define dhcpIPv4_ZERO_PAD_OPTION_CODE                   ( 0u )\r
  70 #define dhcpIPv4_SUBNET_MASK_OPTION_CODE                ( 1u )\r
  71 #define dhcpIPv4_GATEWAY_OPTION_CODE                    ( 3u )\r
  72 #define dhcpIPv4_DNS_SERVER_OPTIONS_CODE                ( 6u )\r
  73 #define dhcpIPv4_DNS_HOSTNAME_OPTIONS_CODE              ( 12u )\r
  74 #define dhcpIPv4_REQUEST_IP_ADDRESS_OPTION_CODE ( 50u )\r
  75 #define dhcpIPv4_LEASE_TIME_OPTION_CODE                 ( 51u )\r
  76 #define dhcpIPv4_MESSAGE_TYPE_OPTION_CODE               ( 53u )\r
  77 #define dhcpIPv4_SERVER_IP_ADDRESS_OPTION_CODE  ( 54u )\r
  78 #define dhcpIPv4_PARAMETER_REQUEST_OPTION_CODE  ( 55u )\r
  79 #define dhcpIPv4_CLIENT_IDENTIFIER_OPTION_CODE  ( 61u )\r
  80 \r
  81 /* The four DHCP message types of interest. */\r
  82 #define dhcpMESSAGE_TYPE_DISCOVER                               ( 1 )\r
  83 #define dhcpMESSAGE_TYPE_OFFER                                  ( 2 )\r
  84 #define dhcpMESSAGE_TYPE_REQUEST                                ( 3 )\r
  85 #define dhcpMESSAGE_TYPE_ACK                                    ( 5 )\r
  86 #define dhcpMESSAGE_TYPE_NACK                                   ( 6 )\r
  87 \r
  88 /* Offsets into the transmitted DHCP options fields at which various parameters\r
  89 are located. */\r
  90 #define dhcpCLIENT_IDENTIFIER_OFFSET                    ( 5 )\r
  91 #define dhcpREQUESTED_IP_ADDRESS_OFFSET                 ( 13 )\r
  92 #define dhcpDHCP_SERVER_IP_ADDRESS_OFFSET               ( 19 )\r
  93 \r
  94 /* Values used in the DHCP packets. */\r
  95 #define dhcpREQUEST_OPCODE                                              ( 1 )\r
  96 #define dhcpREPLY_OPCODE                                                ( 2 )\r
  97 #define dhcpADDRESS_TYPE_ETHERNET                               ( 1 )\r
  98 #define dhcpETHERNET_ADDRESS_LENGTH                             ( 6 )\r
  99 \r
 100 /* If a lease time is not received, use the default of two days. */\r
 101 /* 48 hours in ticks.  Can not use pdMS_TO_TICKS() as integer overflow can occur. */\r
 102 #define dhcpDEFAULT_LEASE_TIME                                  ( ( 48UL * 60UL * 60UL ) * configTICK_RATE_HZ )\r
 103 \r
 104 /* Don't allow the lease time to be too short. */\r
 105 #define dhcpMINIMUM_LEASE_TIME                                  ( pdMS_TO_TICKS( 60000UL ) )    /* 60 seconds in ticks. */\r
 106 \r
 107 /* Marks the end of the variable length options field in the DHCP packet. */\r
 108 #define dhcpOPTION_END_BYTE 0xffu\r
 109 \r
 110 /* Offset into a DHCP message at which the first byte of the options is\r
 111 located. */\r
 112 #define dhcpFIRST_OPTION_BYTE_OFFSET                    ( 0xf0 )\r
 113 \r
 114 /* When walking the variable length options field, the following value is used\r
 115 to ensure the walk has not gone past the end of the valid options.  2 bytes is\r
 116 made up of the length byte, and minimum one byte value. */\r
 117 #define dhcpMAX_OPTION_LENGTH_OF_INTEREST               ( 2L )\r
 118 \r
 119 /* Standard DHCP port numbers and magic cookie value.\r
 120 DHCPv4 uses UDP port number  68 for clients and port number  67 for servers.\r
 121 */\r
 122 #if( ipconfigBYTE_ORDER == pdFREERTOS_LITTLE_ENDIAN )\r
 123         #define dhcpCLIENT_PORT 0x4400u\r
 124         #define dhcpSERVER_PORT 0x4300u\r
 125         #define dhcpCOOKIE              0x63538263ul\r
 126         #define dhcpBROADCAST   0x0080u\r
 127 #else\r
 128         #define dhcpCLIENT_PORT 0x0044u\r
 129         #define dhcpSERVER_PORT 0x0043u\r
 130         #define dhcpCOOKIE              0x63825363ul\r
 131         #define dhcpBROADCAST   0x8000u\r
 132 #endif /* ipconfigBYTE_ORDER */\r
 133 \r
 134 #include "pack_struct_start.h"\r
 135 struct xDHCPMessage\r
 136 {\r
 137         uint8_t ucOpcode;\r
 138         uint8_t ucAddressType;\r
 139         uint8_t ucAddressLength;\r
 140         uint8_t ucHops;\r
 141         uint32_t ulTransactionID;\r
 142         uint16_t usElapsedTime;\r
 143         uint16_t usFlags;\r
 144         uint32_t ulClientIPAddress_ciaddr;\r
 145         uint32_t ulYourIPAddress_yiaddr;\r
 146         uint32_t ulServerIPAddress_siaddr;\r
 147         uint32_t ulRelayAgentIPAddress_giaddr;\r
 148         uint8_t ucClientHardwareAddress[ dhcpCLIENT_HARDWARE_ADDRESS_LENGTH ];\r
 149         uint8_t ucServerHostName[ dhcpSERVER_HOST_NAME_LENGTH ];\r
 150         uint8_t ucBootFileName[ dhcpBOOT_FILE_NAME_LENGTH ];\r
 151         uint32_t ulDHCPCookie;\r
 152         uint8_t ucFirstOptionByte;\r
 153 }\r
 154 #include "pack_struct_end.h"\r
 155 typedef struct xDHCPMessage DHCPMessage_t;\r
 156 \r
 157 /* DHCP state machine states. */\r
 158 typedef enum\r
 159 {\r
 160         eWaitingSendFirstDiscover = 0,  /* Initial state.  Send a discover the first time it is called, and reset all timers. */\r
 161         eWaitingOffer,                                  /* Either resend the discover, or, if the offer is forthcoming, send a request. */\r
 162         eWaitingAcknowledge,                    /* Either resend the request. */\r
 163         #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 164                 eGetLinkLayerAddress,           /* When DHCP didn't respond, try to obtain a LinkLayer address 168.254.x.x. */\r
 165         #endif\r
 166         eLeasedAddress,                                 /* Resend the request at the appropriate time to renew the lease. */\r
 167         eNotUsingLeasedAddress                  /* DHCP failed, and a default IP address is being used. */\r
 168 } eDHCPState_t;\r
 169 \r
 170 /* Hold information in between steps in the DHCP state machine. */\r
 171 struct xDHCP_DATA\r
 172 {\r
 173         uint32_t ulTransactionId;\r
 174         uint32_t ulOfferedIPAddress;\r
 175         uint32_t ulDHCPServerAddress;\r
 176         uint32_t ulLeaseTime;\r
 177         /* Hold information on the current timer state. */\r
 178         TickType_t xDHCPTxTime;\r
 179         TickType_t xDHCPTxPeriod;\r
 180         /* Try both without and with the broadcast flag */\r
 181         BaseType_t xUseBroadcast;\r
 182         /* Maintains the DHCP state machine state. */\r
 183         eDHCPState_t eDHCPState;\r
 184         /* The UDP socket used for all incoming and outgoing DHCP traffic. */\r
 185         Socket_t xDHCPSocket;\r
 186 };\r
 187 \r
 188 typedef struct xDHCP_DATA DHCPData_t;\r
 189 \r
 190 #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 191         /* Define the Link Layer IP address: 169.254.x.x */\r
 192         #define LINK_LAYER_ADDRESS_0    169\r
 193         #define LINK_LAYER_ADDRESS_1    254\r
 194 \r
 195         /* Define the netmask used: 255.255.0.0 */\r
 196         #define LINK_LAYER_NETMASK_0    255\r
 197         #define LINK_LAYER_NETMASK_1    255\r
 198         #define LINK_LAYER_NETMASK_2    0\r
 199         #define LINK_LAYER_NETMASK_3    0\r
 200 #endif\r
 201 \r
 202 \r
 203 /*\r
 204  * Generate a DHCP discover message and send it on the DHCP socket.\r
 205  */\r
 206 static void prvSendDHCPDiscover( void );\r
 207 \r
 208 /*\r
 209  * Interpret message received on the DHCP socket.\r
 210  */\r
 211 static BaseType_t prvProcessDHCPReplies( BaseType_t xExpectedMessageType );\r
 212 \r
 213 /*\r
 214  * Generate a DHCP request packet, and send it on the DHCP socket.\r
 215  */\r
 216 static void prvSendDHCPRequest( void );\r
 217 \r
 218 /*\r
 219  * Prepare to start a DHCP transaction.  This initialises some state variables\r
 220  * and creates the DHCP socket if necessary.\r
 221  */\r
 222 static void prvInitialiseDHCP( void );\r
 223 \r
 224 /*\r
 225  * Creates the part of outgoing DHCP messages that are common to all outgoing\r
 226  * DHCP messages.\r
 227  */\r
 228 static uint8_t *prvCreatePartDHCPMessage( struct freertos_sockaddr *pxAddress, BaseType_t xOpcode, const uint8_t * const pucOptionsArray, size_t *pxOptionsArraySize );\r
 229 \r
 230 /*\r
 231  * Create the DHCP socket, if it has not been created already.\r
 232  */\r
 233 static void prvCreateDHCPSocket( void );\r
 234 \r
 235 /*\r
 236  * After DHCP has failed to answer, prepare everything to start searching\r
 237  * for (trying-out) LinkLayer IP-addresses, using the random method: Send\r
 238  * a gratuitous ARP request and wait if another device responds to it.\r
 239  */\r
 240 #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 241         static void prvPrepareLinkLayerIPLookUp( void );\r
 242 #endif\r
 243 \r
 244 /*-----------------------------------------------------------*/\r
 245 \r
 246 /* The next DHCP transaction Id to be used. */\r
 247 static DHCPData_t xDHCPData;\r
 248 \r
 249 /*-----------------------------------------------------------*/\r
 250 \r
 251 BaseType_t xIsDHCPSocket( Socket_t xSocket )\r
 252 {\r
 253 BaseType_t xReturn;\r
 254 \r
 255         if( xDHCPData.xDHCPSocket == xSocket )\r
 256         {\r
 257                 xReturn = pdTRUE;\r
 258         }\r
 259         else\r
 260         {\r
 261                 xReturn = pdFALSE;\r
 262         }\r
 263 \r
 264         return xReturn;\r
 265 }\r
 266 /*-----------------------------------------------------------*/\r
 267 \r
 268 void vDHCPProcess( BaseType_t xReset )\r
 269 {\r
 270 BaseType_t xGivingUp = pdFALSE;\r
 271 #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 272         eDHCPCallbackAnswer_t eAnswer;\r
 273 #endif  /* ipconfigUSE_DHCP_HOOK */\r
 274 \r
 275         /* Is DHCP starting over? */\r
 276         if( xReset != pdFALSE )\r
 277         {\r
 278                 xDHCPData.eDHCPState = eWaitingSendFirstDiscover;\r
 279         }\r
 280 \r
 281         switch( xDHCPData.eDHCPState )\r
 282         {\r
 283                 case eWaitingSendFirstDiscover :\r
 284                         /* Ask the user if a DHCP discovery is required. */\r
 285                 #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 286                         eAnswer = xApplicationDHCPHook( eDHCPPhasePreDiscover, xNetworkAddressing.ulDefaultIPAddress );\r
 287                         if( eAnswer == eDHCPContinue )\r
 288                 #endif  /* ipconfigUSE_DHCP_HOOK */\r
 289                         {\r
 290                                 /* Initial state.  Create the DHCP socket, timer, etc. if they\r
 291                                 have not already been created. */\r
 292                                 prvInitialiseDHCP();\r
 293 \r
 294                                 /* See if prvInitialiseDHCP() has creates a socket. */\r
 295                                 if( xDHCPData.xDHCPSocket == NULL )\r
 296                                 {\r
 297                                         xGivingUp = pdTRUE;\r
 298                                         break;\r
 299                                 }\r
 300 \r
 301                                 *ipLOCAL_IP_ADDRESS_POINTER = 0UL;\r
 302 \r
 303                                 /* Send the first discover request. */\r
 304                                 if( xDHCPData.xDHCPSocket != NULL )\r
 305                                 {\r
 306                                         xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 307                                         prvSendDHCPDiscover( );\r
 308                                         xDHCPData.eDHCPState = eWaitingOffer;\r
 309                                 }\r
 310                         }\r
 311                 #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 312                         else\r
 313                         {\r
 314                                 if( eAnswer == eDHCPUseDefaults )\r
 315                                 {\r
 316                                         memcpy( &xNetworkAddressing, &xDefaultAddressing, sizeof( xNetworkAddressing ) );\r
 317                                 }\r
 318 \r
 319                                 /* The user indicates that the DHCP process does not continue. */\r
 320                                 xGivingUp = pdTRUE;\r
 321                         }\r
 322                 #endif  /* ipconfigUSE_DHCP_HOOK */\r
 323                         break;\r
 324 \r
 325                 case eWaitingOffer :\r
 326 \r
 327                         xGivingUp = pdFALSE;\r
 328 \r
 329                         /* Look for offers coming in. */\r
 330                         if( prvProcessDHCPReplies( dhcpMESSAGE_TYPE_OFFER ) == pdPASS )\r
 331                         {\r
 332                         #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 333                                 /* Ask the user if a DHCP request is required. */\r
 334                                 eAnswer = xApplicationDHCPHook( eDHCPPhasePreRequest, xDHCPData.ulOfferedIPAddress );\r
 335 \r
 336                                 if( eAnswer == eDHCPContinue )\r
 337                         #endif  /* ipconfigUSE_DHCP_HOOK */\r
 338                                 {\r
 339                                         /* An offer has been made, the user wants to continue,\r
 340                                         generate the request. */\r
 341                                         xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 342                                         xDHCPData.xDHCPTxPeriod = dhcpINITIAL_DHCP_TX_PERIOD;\r
 343                                         prvSendDHCPRequest( );\r
 344                                         xDHCPData.eDHCPState = eWaitingAcknowledge;\r
 345                                         break;\r
 346                                 }\r
 347 \r
 348                         #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 349                                 if( eAnswer == eDHCPUseDefaults )\r
 350                                 {\r
 351                                         memcpy( &xNetworkAddressing, &xDefaultAddressing, sizeof( xNetworkAddressing ) );\r
 352                                 }\r
 353 \r
 354                                 /* The user indicates that the DHCP process does not continue. */\r
 355                                 xGivingUp = pdTRUE;\r
 356                         #endif  /* ipconfigUSE_DHCP_HOOK */\r
 357                         }\r
 358                         else if( ( xTaskGetTickCount() - xDHCPData.xDHCPTxTime ) > xDHCPData.xDHCPTxPeriod )\r
 359                         {\r
 360                                 /* It is time to send another Discover.  Increase the time\r
 361                                 period, and if it has not got to the point of giving up - send\r
 362                                 another discovery. */\r
 363                                 xDHCPData.xDHCPTxPeriod <<= 1;\r
 364 \r
 365                                 if( xDHCPData.xDHCPTxPeriod <= ipconfigMAXIMUM_DISCOVER_TX_PERIOD )\r
 366                                 {\r
 367                                         xDHCPData.ulTransactionId++;\r
 368                                         xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 369                                         xDHCPData.xUseBroadcast = !xDHCPData.xUseBroadcast;\r
 370                                         prvSendDHCPDiscover( );\r
 371                                         FreeRTOS_debug_printf( ( "vDHCPProcess: timeout %lu ticks\n", xDHCPData.xDHCPTxPeriod ) );\r
 372                                 }\r
 373                                 else\r
 374                                 {\r
 375                                         FreeRTOS_debug_printf( ( "vDHCPProcess: giving up %lu > %lu ticks\n", xDHCPData.xDHCPTxPeriod, ipconfigMAXIMUM_DISCOVER_TX_PERIOD ) );\r
 376 \r
 377                                         #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 378                                         {\r
 379                                                 /* Only use a fake Ack if the default IP address == 0x00\r
 380                                                 and the link local addressing is used.  Start searching\r
 381                                                 a free LinkLayer IP-address.  Next state will be\r
 382                                                 'eGetLinkLayerAddress'. */\r
 383                                                 prvPrepareLinkLayerIPLookUp();\r
 384 \r
 385                                                 /* Setting an IP address manually so set to not using\r
 386                                                 leased address mode. */\r
 387                                                 xDHCPData.eDHCPState = eGetLinkLayerAddress;\r
 388                                         }\r
 389                                         #else\r
 390                                         {\r
 391                                                 xGivingUp = pdTRUE;\r
 392                                         }\r
 393                                         #endif /* ipconfigDHCP_FALL_BACK_AUTO_IP */\r
 394                                 }\r
 395                         }\r
 396                         break;\r
 397 \r
 398                 case eWaitingAcknowledge :\r
 399 \r
 400                         /* Look for acks coming in. */\r
 401                         if( prvProcessDHCPReplies( dhcpMESSAGE_TYPE_ACK ) == pdPASS )\r
 402                         {\r
 403                                 FreeRTOS_debug_printf( ( "vDHCPProcess: acked %lxip\n", FreeRTOS_ntohl( xDHCPData.ulOfferedIPAddress ) ) );\r
 404 \r
 405                                 /* DHCP completed.  The IP address can now be used, and the\r
 406                                 timer set to the lease timeout time. */\r
 407                                 *ipLOCAL_IP_ADDRESS_POINTER = xDHCPData.ulOfferedIPAddress;\r
 408 \r
 409                                 /* Setting the 'local' broadcast address, something like\r
 410                                 '192.168.1.255'. */\r
 411                                 xNetworkAddressing.ulBroadcastAddress = ( xDHCPData.ulOfferedIPAddress & xNetworkAddressing.ulNetMask ) |  ~xNetworkAddressing.ulNetMask;\r
 412                                 xDHCPData.eDHCPState = eLeasedAddress;\r
 413 \r
 414                                 iptraceDHCP_SUCCEDEED( xDHCPData.ulOfferedIPAddress );\r
 415 \r
 416                                 /* DHCP failed, the default configured IP-address will be used\r
 417                                 Now call vIPNetworkUpCalls() to send the network-up event and\r
 418                                 start the ARP timer. */\r
 419                                 vIPNetworkUpCalls( );\r
 420 \r
 421                                 /* Close socket to ensure packets don't queue on it. */\r
 422                                 vSocketClose( xDHCPData.xDHCPSocket );\r
 423                                 xDHCPData.xDHCPSocket = NULL;\r
 424 \r
 425                                 if( xDHCPData.ulLeaseTime == 0UL )\r
 426                                 {\r
 427                                         xDHCPData.ulLeaseTime = dhcpDEFAULT_LEASE_TIME;\r
 428                                 }\r
 429                                 else if( xDHCPData.ulLeaseTime < dhcpMINIMUM_LEASE_TIME )\r
 430                                 {\r
 431                                         xDHCPData.ulLeaseTime = dhcpMINIMUM_LEASE_TIME;\r
 432                                 }\r
 433                                 else\r
 434                                 {\r
 435                                         /* The lease time is already valid. */\r
 436                                 }\r
 437 \r
 438                                 /* Check for clashes. */\r
 439                                 vARPSendGratuitous();\r
 440                                 vIPReloadDHCPTimer( xDHCPData.ulLeaseTime );\r
 441                         }\r
 442                         else\r
 443                         {\r
 444                                 /* Is it time to send another Discover? */\r
 445                                 if( ( xTaskGetTickCount() - xDHCPData.xDHCPTxTime ) > xDHCPData.xDHCPTxPeriod )\r
 446                                 {\r
 447                                         /* Increase the time period, and if it has not got to the\r
 448                                         point of giving up - send another request. */\r
 449                                         xDHCPData.xDHCPTxPeriod <<= 1;\r
 450 \r
 451                                         if( xDHCPData.xDHCPTxPeriod <= ipconfigMAXIMUM_DISCOVER_TX_PERIOD )\r
 452                                         {\r
 453                                                 xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 454                                                 prvSendDHCPRequest( );\r
 455                                         }\r
 456                                         else\r
 457                                         {\r
 458                                                 /* Give up, start again. */\r
 459                                                 xDHCPData.eDHCPState = eWaitingSendFirstDiscover;\r
 460                                         }\r
 461                                 }\r
 462                         }\r
 463                         break;\r
 464 \r
 465         #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 466                 case eGetLinkLayerAddress:\r
 467                         if( ( xTaskGetTickCount() - xDHCPData.xDHCPTxTime ) > xDHCPData.xDHCPTxPeriod )\r
 468                         {\r
 469                                 if( xARPHadIPClash == pdFALSE )\r
 470                                 {\r
 471                                         /* ARP OK. proceed. */\r
 472                                         iptraceDHCP_SUCCEDEED( xDHCPData.ulOfferedIPAddress );\r
 473 \r
 474                                         /* Auto-IP succeeded, the default configured IP-address will\r
 475                                         be used.  Now call vIPNetworkUpCalls() to send the\r
 476                                         network-up event and start the ARP timer. */\r
 477                                         vIPNetworkUpCalls( );\r
 478                                         xDHCPData.eDHCPState = eNotUsingLeasedAddress;\r
 479                                 }\r
 480                                 else\r
 481                                 {\r
 482                                         /* ARP clashed - try another IP address. */\r
 483                                         prvPrepareLinkLayerIPLookUp();\r
 484 \r
 485                                         /* Setting an IP address manually so set to not using leased\r
 486                                         address mode. */\r
 487                                         xDHCPData.eDHCPState = eGetLinkLayerAddress;\r
 488                                 }\r
 489                         }\r
 490                         break;\r
 491         #endif  /* ipconfigDHCP_FALL_BACK_AUTO_IP */\r
 492 \r
 493                 case eLeasedAddress :\r
 494 \r
 495                         /* Resend the request at the appropriate time to renew the lease. */\r
 496                         prvCreateDHCPSocket();\r
 497 \r
 498                         if( xDHCPData.xDHCPSocket != NULL )\r
 499                         {\r
 500                                 xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 501                                 xDHCPData.xDHCPTxPeriod = dhcpINITIAL_DHCP_TX_PERIOD;\r
 502                                 prvSendDHCPRequest( );\r
 503                                 xDHCPData.eDHCPState = eWaitingAcknowledge;\r
 504 \r
 505                                 /* From now on, we should be called more often */\r
 506                                 vIPReloadDHCPTimer( dhcpINITIAL_TIMER_PERIOD );\r
 507                         }\r
 508                         break;\r
 509 \r
 510                 case eNotUsingLeasedAddress:\r
 511 \r
 512                         vIPSetDHCPTimerEnableState( pdFALSE );\r
 513                         break;\r
 514 \r
 515                 default:\r
 516                         break;\r
 517         }\r
 518 \r
 519         if( xGivingUp != pdFALSE )\r
 520         {\r
 521                 /* xGivingUp became true either because of a time-out, or because\r
 522                 xApplicationDHCPHook() returned another value than 'eDHCPContinue',\r
 523                 meaning that the conversion is cancelled from here. */\r
 524 \r
 525                 /* Revert to static IP address. */\r
 526                 taskENTER_CRITICAL();\r
 527                 {\r
 528                         *ipLOCAL_IP_ADDRESS_POINTER = xNetworkAddressing.ulDefaultIPAddress;\r
 529                         iptraceDHCP_REQUESTS_FAILED_USING_DEFAULT_IP_ADDRESS( xNetworkAddressing.ulDefaultIPAddress );\r
 530                 }\r
 531                 taskEXIT_CRITICAL();\r
 532 \r
 533                 xDHCPData.eDHCPState = eNotUsingLeasedAddress;\r
 534                 vIPSetDHCPTimerEnableState( pdFALSE );\r
 535 \r
 536                 /* DHCP failed, the default configured IP-address will be used.  Now\r
 537                 call vIPNetworkUpCalls() to send the network-up event and start the ARP\r
 538                 timer. */\r
 539                 vIPNetworkUpCalls( );\r
 540 \r
 541                 /* Test if socket was indeed created. */\r
 542                 if( xDHCPData.xDHCPSocket != NULL )\r
 543                 {\r
 544                         /* Close socket to ensure packets don't queue on it. */\r
 545                         vSocketClose( xDHCPData.xDHCPSocket );\r
 546                         xDHCPData.xDHCPSocket = NULL;\r
 547                 }\r
 548         }\r
 549 }\r
 550 /*-----------------------------------------------------------*/\r
 551 \r
 552 static void prvCreateDHCPSocket( void )\r
 553 {\r
 554 struct freertos_sockaddr xAddress;\r
 555 BaseType_t xReturn;\r
 556 TickType_t xTimeoutTime = ( TickType_t ) 0;\r
 557 \r
 558         /* Create the socket, if it has not already been created. */\r
 559         if( xDHCPData.xDHCPSocket == NULL )\r
 560         {\r
 561                 xDHCPData.xDHCPSocket = FreeRTOS_socket( FREERTOS_AF_INET, FREERTOS_SOCK_DGRAM, FREERTOS_IPPROTO_UDP );\r
 562                 if( xDHCPData.xDHCPSocket != FREERTOS_INVALID_SOCKET )\r
 563                 {\r
 564 \r
 565                         /* Ensure the Rx and Tx timeouts are zero as the DHCP executes in the\r
 566                         context of the IP task. */\r
 567                         FreeRTOS_setsockopt( xDHCPData.xDHCPSocket, 0, FREERTOS_SO_RCVTIMEO, ( void * ) &xTimeoutTime, sizeof( TickType_t ) );\r
 568                         FreeRTOS_setsockopt( xDHCPData.xDHCPSocket, 0, FREERTOS_SO_SNDTIMEO, ( void * ) &xTimeoutTime, sizeof( TickType_t ) );\r
 569 \r
 570                         /* Bind to the standard DHCP client port. */\r
 571                         xAddress.sin_port = ( uint16_t ) dhcpCLIENT_PORT;\r
 572                         xReturn = vSocketBind( xDHCPData.xDHCPSocket, &xAddress, sizeof( xAddress ), pdFALSE );\r
 573                         if( xReturn != 0 )\r
 574                         {\r
 575                                 /* Binding failed, close the socket again. */\r
 576                                 vSocketClose( xDHCPData.xDHCPSocket );\r
 577                                 xDHCPData.xDHCPSocket = NULL;\r
 578                         }\r
 579                 }\r
 580                 else\r
 581                 {\r
 582                         /* Change to NULL for easier testing. */\r
 583                         xDHCPData.xDHCPSocket = NULL;\r
 584                 }\r
 585         }\r
 586 }\r
 587 /*-----------------------------------------------------------*/\r
 588 \r
 589 static void prvInitialiseDHCP( void )\r
 590 {\r
 591         /* Initialise the parameters that will be set by the DHCP process. */\r
 592         if( xDHCPData.ulTransactionId == 0ul )\r
 593         {\r
 594                 xDHCPData.ulTransactionId = ipconfigRAND32();\r
 595         }\r
 596         else\r
 597         {\r
 598                 xDHCPData.ulTransactionId++;\r
 599         }\r
 600 \r
 601         xDHCPData.xUseBroadcast = 0;\r
 602         xDHCPData.ulOfferedIPAddress = 0UL;\r
 603         xDHCPData.ulDHCPServerAddress = 0UL;\r
 604         xDHCPData.xDHCPTxPeriod = dhcpINITIAL_DHCP_TX_PERIOD;\r
 605 \r
 606         /* Create the DHCP socket if it has not already been created. */\r
 607         prvCreateDHCPSocket();\r
 608         FreeRTOS_debug_printf( ( "prvInitialiseDHCP: start after %lu ticks\n", dhcpINITIAL_TIMER_PERIOD ) );\r
 609         vIPReloadDHCPTimer( dhcpINITIAL_TIMER_PERIOD );\r
 610 }\r
 611 /*-----------------------------------------------------------*/\r
 612 \r
 613 static BaseType_t prvProcessDHCPReplies( BaseType_t xExpectedMessageType )\r
 614 {\r
 615 uint8_t *pucUDPPayload, *pucLastByte;\r
 616 struct freertos_sockaddr xClient;\r
 617 uint32_t xClientLength = sizeof( xClient );\r
 618 int32_t lBytes;\r
 619 DHCPMessage_t *pxDHCPMessage;\r
 620 uint8_t *pucByte, ucOptionCode, ucLength;\r
 621 uint32_t ulProcessed, ulParameter;\r
 622 BaseType_t xReturn = pdFALSE;\r
 623 const uint32_t ulMandatoryOptions = 2ul; /* DHCP server address, and the correct DHCP message type must be present in the options. */\r
 624 \r
 625         lBytes = FreeRTOS_recvfrom( xDHCPData.xDHCPSocket, ( void * ) &pucUDPPayload, 0ul, FREERTOS_ZERO_COPY, &xClient, &xClientLength );\r
 626 \r
 627         if( lBytes > 0 )\r
 628         {\r
 629                 /* Map a DHCP structure onto the received data. */\r
 630                 pxDHCPMessage = ( DHCPMessage_t * ) ( pucUDPPayload );\r
 631 \r
 632                 /* Sanity check. */\r
 633                 if( ( pxDHCPMessage->ulDHCPCookie == ( uint32_t ) dhcpCOOKIE ) &&\r
 634                         ( pxDHCPMessage->ucOpcode == ( uint8_t ) dhcpREPLY_OPCODE ) &&\r
 635                         ( pxDHCPMessage->ulTransactionID == FreeRTOS_htonl( xDHCPData.ulTransactionId ) ) )\r
 636                 {\r
 637                         if( memcmp( ( void * ) &( pxDHCPMessage->ucClientHardwareAddress ), ( void * ) ipLOCAL_MAC_ADDRESS, sizeof( MACAddress_t ) ) == 0 )\r
 638                         {\r
 639                                 /* None of the essential options have been processed yet. */\r
 640                                 ulProcessed = 0ul;\r
 641 \r
 642                                 /* Walk through the options until the dhcpOPTION_END_BYTE byte\r
 643                                 is found, taking care not to walk off the end of the options. */\r
 644                                 pucByte = &( pxDHCPMessage->ucFirstOptionByte );\r
 645                                 pucLastByte = &( pucUDPPayload[ lBytes - dhcpMAX_OPTION_LENGTH_OF_INTEREST ] );\r
 646 \r
 647                                 while( pucByte < pucLastByte )\r
 648                                 {\r
 649                                         ucOptionCode = pucByte[ 0 ];\r
 650                                         if( ucOptionCode == ( uint8_t ) dhcpOPTION_END_BYTE )\r
 651                                         {\r
 652                                                 /* Ready, the last byte has been seen. */\r
 653                                                 break;\r
 654                                         }\r
 655                                         if( ucOptionCode == ( uint8_t ) dhcpIPv4_ZERO_PAD_OPTION_CODE )\r
 656                                         {\r
 657                                                 /* The value zero is used as a pad byte,\r
 658                                                 it is not followed by a length byte. */\r
 659                                                 pucByte += 1;\r
 660                                                 continue;\r
 661                                         }\r
 662                                         ucLength = pucByte[ 1 ];\r
 663                                         pucByte += 2;\r
 664 \r
 665                                         /* In most cases, a 4-byte network-endian parameter follows,\r
 666                                         just get it once here and use later */\r
 667                                         memcpy( ( void * ) &( ulParameter ), ( void * ) pucByte, ( size_t ) sizeof( ulParameter ) );\r
 668 \r
 669                                         switch( ucOptionCode )\r
 670                                         {\r
 671                                                 case dhcpIPv4_MESSAGE_TYPE_OPTION_CODE  :\r
 672 \r
 673                                                         if( *pucByte == ( uint8_t ) xExpectedMessageType )\r
 674                                                         {\r
 675                                                                 /* The message type is the message type the\r
 676                                                                 state machine is expecting. */\r
 677                                                                 ulProcessed++;\r
 678                                                         }\r
 679                                                         else\r
 680                                                         {\r
 681                                                                 if( *pucByte == ( uint8_t ) dhcpMESSAGE_TYPE_NACK )\r
 682                                                                 {\r
 683                                                                         if( xExpectedMessageType == ( BaseType_t ) dhcpMESSAGE_TYPE_ACK )\r
 684                                                                         {\r
 685                                                                                 /* Start again. */\r
 686                                                                                 xDHCPData.eDHCPState = eWaitingSendFirstDiscover;\r
 687                                                                         }\r
 688                                                                 }\r
 689                                                                 /* Stop processing further options. */\r
 690                                                                 ucLength = 0;\r
 691                                                         }\r
 692                                                         break;\r
 693 \r
 694                                                 case dhcpIPv4_SUBNET_MASK_OPTION_CODE :\r
 695 \r
 696                                                         if( ucLength == sizeof( uint32_t ) )\r
 697                                                         {\r
 698                                                                 xNetworkAddressing.ulNetMask = ulParameter;\r
 699                                                         }\r
 700                                                         break;\r
 701 \r
 702                                                 case dhcpIPv4_GATEWAY_OPTION_CODE :\r
 703                                                         /* The DHCP server may send more than 1 gateway addresses. */\r
 704                                                         if( ucLength >= sizeof( uint32_t ) )\r
 705                                                         {\r
 706                                                                 /* ulProcessed is not incremented in this case\r
 707                                                                 because the gateway is not essential. */\r
 708                                                                 xNetworkAddressing.ulGatewayAddress = ulParameter;\r
 709                                                         }\r
 710                                                         break;\r
 711 \r
 712                                                 case dhcpIPv4_DNS_SERVER_OPTIONS_CODE :\r
 713 \r
 714                                                         /* ulProcessed is not incremented in this case\r
 715                                                         because the DNS server is not essential.  Only the\r
 716                                                         first DNS server address is taken. */\r
 717                                                         xNetworkAddressing.ulDNSServerAddress = ulParameter;\r
 718                                                         break;\r
 719 \r
 720                                                 case dhcpIPv4_SERVER_IP_ADDRESS_OPTION_CODE :\r
 721 \r
 722                                                         if( ucLength == sizeof( uint32_t ) )\r
 723                                                         {\r
 724                                                                 if( xExpectedMessageType == ( BaseType_t ) dhcpMESSAGE_TYPE_OFFER )\r
 725                                                                 {\r
 726                                                                         /* Offers state the replying server. */\r
 727                                                                         ulProcessed++;\r
 728                                                                         xDHCPData.ulDHCPServerAddress = ulParameter;\r
 729                                                                 }\r
 730                                                                 else\r
 731                                                                 {\r
 732                                                                         /* The ack must come from the expected server. */\r
 733                                                                         if( xDHCPData.ulDHCPServerAddress == ulParameter )\r
 734                                                                         {\r
 735                                                                                 ulProcessed++;\r
 736                                                                         }\r
 737                                                                 }\r
 738                                                         }\r
 739                                                         break;\r
 740 \r
 741                                                 case dhcpIPv4_LEASE_TIME_OPTION_CODE :\r
 742 \r
 743                                                         if( ucLength == sizeof( xDHCPData.ulLeaseTime ) )\r
 744                                                         {\r
 745                                                                 /* ulProcessed is not incremented in this case\r
 746                                                                 because the lease time is not essential. */\r
 747                                                                 /* The DHCP parameter is in seconds, convert\r
 748                                                                 to host-endian format. */\r
 749                                                                 xDHCPData.ulLeaseTime = FreeRTOS_ntohl( ulParameter );\r
 750 \r
 751                                                                 /* Divide the lease time by two to ensure a\r
 752                                                                 renew request is sent before the lease actually\r
 753                                                                 expires. */\r
 754                                                                 xDHCPData.ulLeaseTime >>= 1UL;\r
 755 \r
 756                                                                 /* Multiply with configTICK_RATE_HZ to get clock\r
 757                                                                 ticks. */\r
 758                                                                 xDHCPData.ulLeaseTime = configTICK_RATE_HZ * xDHCPData.ulLeaseTime;\r
 759                                                         }\r
 760                                                         break;\r
 761 \r
 762                                                 default :\r
 763 \r
 764                                                         /* Not interested in this field. */\r
 765 \r
 766                                                         break;\r
 767                                         }\r
 768 \r
 769                                         /* Jump over the data to find the next option code. */\r
 770                                         if( ucLength == 0u )\r
 771                                         {\r
 772                                                 break;\r
 773                                         }\r
 774                                         else\r
 775                                         {\r
 776                                                 pucByte += ucLength;\r
 777                                         }\r
 778                                 }\r
 779 \r
 780                                 /* Were all the mandatory options received? */\r
 781                                 if( ulProcessed >= ulMandatoryOptions )\r
 782                                 {\r
 783                                         /* HT:endian: used to be network order */\r
 784                                         xDHCPData.ulOfferedIPAddress = pxDHCPMessage->ulYourIPAddress_yiaddr;\r
 785                                         FreeRTOS_printf( ( "vDHCPProcess: offer %lxip\n", FreeRTOS_ntohl( xDHCPData.ulOfferedIPAddress ) ) );\r
 786                                         xReturn = pdPASS;\r
 787                                 }\r
 788                         }\r
 789                 }\r
 790 \r
 791                 FreeRTOS_ReleaseUDPPayloadBuffer( ( void * ) pucUDPPayload );\r
 792         } /* if( lBytes > 0 ) */\r
 793 \r
 794         return xReturn;\r
 795 }\r
 796 /*-----------------------------------------------------------*/\r
 797 \r
 798 static uint8_t *prvCreatePartDHCPMessage( struct freertos_sockaddr *pxAddress, BaseType_t xOpcode, const uint8_t * const pucOptionsArray, size_t *pxOptionsArraySize )\r
 799 {\r
 800 DHCPMessage_t *pxDHCPMessage;\r
 801 size_t xRequiredBufferSize = sizeof( DHCPMessage_t ) + *pxOptionsArraySize;\r
 802 uint8_t *pucUDPPayloadBuffer;\r
 803 \r
 804 #if( ipconfigDHCP_REGISTER_HOSTNAME == 1 )\r
 805         const char *pucHostName = pcApplicationHostnameHook ();\r
 806         size_t xNameLength = strlen( pucHostName );\r
 807         uint8_t *pucPtr;\r
 808 \r
 809         xRequiredBufferSize += ( 2 + xNameLength );\r
 810 #endif\r
 811 \r
 812         /* Get a buffer.  This uses a maximum delay, but the delay will be capped\r
 813         to ipconfigUDP_MAX_SEND_BLOCK_TIME_TICKS so the return value still needs to\r
 814         be test. */\r
 815         do\r
 816         {\r
 817         } while( ( pucUDPPayloadBuffer = ( uint8_t * ) FreeRTOS_GetUDPPayloadBuffer( xRequiredBufferSize, portMAX_DELAY ) ) == NULL );\r
 818 \r
 819         pxDHCPMessage = ( DHCPMessage_t * ) pucUDPPayloadBuffer;\r
 820 \r
 821         /* Most fields need to be zero. */\r
 822         memset( ( void * ) pxDHCPMessage, 0x00, sizeof( DHCPMessage_t ) );\r
 823 \r
 824         /* Create the message. */\r
 825         pxDHCPMessage->ucOpcode = ( uint8_t ) xOpcode;\r
 826         pxDHCPMessage->ucAddressType = ( uint8_t ) dhcpADDRESS_TYPE_ETHERNET;\r
 827         pxDHCPMessage->ucAddressLength = ( uint8_t ) dhcpETHERNET_ADDRESS_LENGTH;\r
 828 \r
 829         /* ulTransactionID doesn't really need a htonl() translation, but when DHCP\r
 830         times out, it is nicer to see an increasing number in this ID field */\r
 831         pxDHCPMessage->ulTransactionID = FreeRTOS_htonl( xDHCPData.ulTransactionId );\r
 832         pxDHCPMessage->ulDHCPCookie = ( uint32_t ) dhcpCOOKIE;\r
 833         if( xDHCPData.xUseBroadcast != pdFALSE )\r
 834         {\r
 835                 pxDHCPMessage->usFlags = ( uint16_t ) dhcpBROADCAST;\r
 836         }\r
 837         else\r
 838         {\r
 839                 pxDHCPMessage->usFlags = 0u;\r
 840         }\r
 841 \r
 842         memcpy( ( void * ) &( pxDHCPMessage->ucClientHardwareAddress[ 0 ] ), ( void * ) ipLOCAL_MAC_ADDRESS, sizeof( MACAddress_t ) );\r
 843 \r
 844         /* Copy in the const part of the options options. */\r
 845         memcpy( ( void * ) &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET ] ), ( void * ) pucOptionsArray, *pxOptionsArraySize );\r
 846 \r
 847         #if( ipconfigDHCP_REGISTER_HOSTNAME == 1 )\r
 848         {\r
 849                 /* With this option, the hostname can be registered as well which makes\r
 850                 it easier to lookup a device in a router's list of DHCP clients. */\r
 851 \r
 852                 /* Point to where the OPTION_END was stored to add data. */\r
 853                 pucPtr = &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET + ( *pxOptionsArraySize - 1 ) ] );\r
 854                 pucPtr[ 0 ] = dhcpIPv4_DNS_HOSTNAME_OPTIONS_CODE;\r
 855                 pucPtr[ 1 ] = ( uint8_t ) xNameLength;\r
 856                 memcpy( ( void *) ( pucPtr + 2 ), pucHostName, xNameLength );\r
 857                 pucPtr[ 2 + xNameLength ] = dhcpOPTION_END_BYTE;\r
 858                 *pxOptionsArraySize += ( 2 + xNameLength );\r
 859         }\r
 860         #endif\r
 861 \r
 862         /* Map in the client identifier. */\r
 863         memcpy( ( void * ) &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET + dhcpCLIENT_IDENTIFIER_OFFSET ] ),\r
 864                 ( void * ) ipLOCAL_MAC_ADDRESS, sizeof( MACAddress_t ) );\r
 865 \r
 866         /* Set the addressing. */\r
 867         pxAddress->sin_addr = ipBROADCAST_IP_ADDRESS;\r
 868         pxAddress->sin_port = ( uint16_t ) dhcpSERVER_PORT;\r
 869 \r
 870         return pucUDPPayloadBuffer;\r
 871 }\r
 872 /*-----------------------------------------------------------*/\r
 873 \r
 874 static void prvSendDHCPRequest( void )\r
 875 {\r
 876 uint8_t *pucUDPPayloadBuffer;\r
 877 struct freertos_sockaddr xAddress;\r
 878 static const uint8_t ucDHCPRequestOptions[] =\r
 879 {\r
 880         /* Do not change the ordering without also changing\r
 881         dhcpCLIENT_IDENTIFIER_OFFSET, dhcpREQUESTED_IP_ADDRESS_OFFSET and\r
 882         dhcpDHCP_SERVER_IP_ADDRESS_OFFSET. */\r
 883         dhcpIPv4_MESSAGE_TYPE_OPTION_CODE, 1, dhcpMESSAGE_TYPE_REQUEST,         /* Message type option. */\r
 884         dhcpIPv4_CLIENT_IDENTIFIER_OPTION_CODE, 6, 0, 0, 0, 0, 0, 0,                    /* Client identifier. */\r
 885         dhcpIPv4_REQUEST_IP_ADDRESS_OPTION_CODE, 4, 0, 0, 0, 0,                         /* The IP address being requested. */\r
 886         dhcpIPv4_SERVER_IP_ADDRESS_OPTION_CODE, 4, 0, 0, 0, 0,                          /* The IP address of the DHCP server. */\r
 887         dhcpOPTION_END_BYTE\r
 888 };\r
 889 size_t xOptionsLength = sizeof( ucDHCPRequestOptions );\r
 890 \r
 891         pucUDPPayloadBuffer = prvCreatePartDHCPMessage( &xAddress, ( uint8_t ) dhcpREQUEST_OPCODE, ucDHCPRequestOptions, &xOptionsLength );\r
 892 \r
 893         /* Copy in the IP address being requested. */\r
 894         memcpy( ( void * ) &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET + dhcpREQUESTED_IP_ADDRESS_OFFSET ] ),\r
 895                 ( void * ) &( xDHCPData.ulOfferedIPAddress ), sizeof( xDHCPData.ulOfferedIPAddress ) );\r
 896 \r
 897         /* Copy in the address of the DHCP server being used. */\r
 898         memcpy( ( void * ) &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET + dhcpDHCP_SERVER_IP_ADDRESS_OFFSET ] ),\r
 899                 ( void * ) &( xDHCPData.ulDHCPServerAddress ), sizeof( xDHCPData.ulDHCPServerAddress ) );\r
 900 \r
 901         FreeRTOS_debug_printf( ( "vDHCPProcess: reply %lxip\n", FreeRTOS_ntohl( xDHCPData.ulOfferedIPAddress ) ) );\r
 902         iptraceSENDING_DHCP_REQUEST();\r
 903 \r
 904         if( FreeRTOS_sendto( xDHCPData.xDHCPSocket, pucUDPPayloadBuffer, ( sizeof( DHCPMessage_t ) + xOptionsLength ), FREERTOS_ZERO_COPY, &xAddress, sizeof( xAddress ) ) == 0 )\r
 905         {\r
 906                 /* The packet was not successfully queued for sending and must be\r
 907                 returned to the stack. */\r
 908                 FreeRTOS_ReleaseUDPPayloadBuffer( pucUDPPayloadBuffer );\r
 909         }\r
 910 }\r
 911 /*-----------------------------------------------------------*/\r
 912 \r
 913 static void prvSendDHCPDiscover( void )\r
 914 {\r
 915 uint8_t *pucUDPPayloadBuffer;\r
 916 struct freertos_sockaddr xAddress;\r
 917 static const uint8_t ucDHCPDiscoverOptions[] =\r
 918 {\r
 919         /* Do not change the ordering without also changing dhcpCLIENT_IDENTIFIER_OFFSET. */\r
 920         dhcpIPv4_MESSAGE_TYPE_OPTION_CODE, 1, dhcpMESSAGE_TYPE_DISCOVER,                                        /* Message type option. */\r
 921         dhcpIPv4_CLIENT_IDENTIFIER_OPTION_CODE, 6, 0, 0, 0, 0, 0, 0,                                            /* Client identifier. */\r
 922         dhcpIPv4_PARAMETER_REQUEST_OPTION_CODE, 3, dhcpIPv4_SUBNET_MASK_OPTION_CODE, dhcpIPv4_GATEWAY_OPTION_CODE, dhcpIPv4_DNS_SERVER_OPTIONS_CODE,    /* Parameter request option. */\r
 923         dhcpOPTION_END_BYTE\r
 924 };\r
 925 size_t xOptionsLength = sizeof( ucDHCPDiscoverOptions );\r
 926 \r
 927         pucUDPPayloadBuffer = prvCreatePartDHCPMessage( &xAddress, ( uint8_t ) dhcpREQUEST_OPCODE, ucDHCPDiscoverOptions, &xOptionsLength );\r
 928 \r
 929         FreeRTOS_debug_printf( ( "vDHCPProcess: discover\n" ) );\r
 930         iptraceSENDING_DHCP_DISCOVER();\r
 931 \r
 932         if( FreeRTOS_sendto( xDHCPData.xDHCPSocket, pucUDPPayloadBuffer, ( sizeof( DHCPMessage_t ) + xOptionsLength ), FREERTOS_ZERO_COPY, &xAddress, sizeof( xAddress ) ) == 0 )\r
 933         {\r
 934                 /* The packet was not successfully queued for sending and must be\r
 935                 returned to the stack. */\r
 936                 FreeRTOS_ReleaseUDPPayloadBuffer( pucUDPPayloadBuffer );\r
 937         }\r
 938 }\r
 939 /*-----------------------------------------------------------*/\r
 940 \r
 941 #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 942 \r
 943         static void prvPrepareLinkLayerIPLookUp( void )\r
 944         {\r
 945         uint8_t ucLinkLayerIPAddress[ 2 ];\r
 946 \r
 947                 /* After DHCP has failed to answer, prepare everything to start\r
 948                 trying-out LinkLayer IP-addresses, using the random method. */\r
 949                 xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 950 \r
 951                 ucLinkLayerIPAddress[ 0 ] = ( uint8_t )1 + ( uint8_t )( ipconfigRAND32() % 0xFDu );             /* get value 1..254 for IP-address 3rd byte of IP address to try. */\r
 952                 ucLinkLayerIPAddress[ 1 ] = ( uint8_t )1 + ( uint8_t )( ipconfigRAND32() % 0xFDu );             /* get value 1..254 for IP-address 4th byte of IP address to try. */\r
 953 \r
 954                 xNetworkAddressing.ulGatewayAddress = FreeRTOS_htonl( 0xA9FE0203 );\r
 955 \r
 956                 /* prepare xDHCPData with data to test. */\r
 957                 xDHCPData.ulOfferedIPAddress =\r
 958                         FreeRTOS_inet_addr_quick( LINK_LAYER_ADDRESS_0, LINK_LAYER_ADDRESS_1, ucLinkLayerIPAddress[ 0 ], ucLinkLayerIPAddress[ 1 ] );\r
 959 \r
 960                 xDHCPData.ulLeaseTime = dhcpDEFAULT_LEASE_TIME;  /*  don't care about lease time. just put anything. */\r
 961 \r
 962                 xNetworkAddressing.ulNetMask =\r
 963                         FreeRTOS_inet_addr_quick( LINK_LAYER_NETMASK_0, LINK_LAYER_NETMASK_1, LINK_LAYER_NETMASK_2, LINK_LAYER_NETMASK_3 );\r
 964 \r
 965                 /* DHCP completed.  The IP address can now be used, and the\r
 966                 timer set to the lease timeout time. */\r
 967                 *ipLOCAL_IP_ADDRESS_POINTER = xDHCPData.ulOfferedIPAddress;\r
 968 \r
 969                 /* Setting the 'local' broadcast address, something like 192.168.1.255' */\r
 970                 xNetworkAddressing.ulBroadcastAddress = ( xDHCPData.ulOfferedIPAddress & xNetworkAddressing.ulNetMask ) |  ~xNetworkAddressing.ulNetMask;\r
 971 \r
 972                 /* Close socket to ensure packets don't queue on it. not needed anymore as DHCP failed. but still need timer for ARP testing. */\r
 973                 vSocketClose( xDHCPData.xDHCPSocket );\r
 974                 xDHCPData.xDHCPSocket = NULL;\r
 975                 xDHCPData.xDHCPTxPeriod = pdMS_TO_TICKS( 3000ul + ( ipconfigRAND32() & 0x3fful ) ); /*  do ARP test every (3 + 0-1024mS) seconds. */\r
 976 \r
 977                 xARPHadIPClash = pdFALSE;          /* reset flag that shows if have ARP clash. */\r
 978                 vARPSendGratuitous();\r
 979         }\r
 980 \r
 981 #endif /* ipconfigDHCP_FALL_BACK_AUTO_IP */\r
 982 /*-----------------------------------------------------------*/\r
 983 \r
 984 #endif /* ipconfigUSE_DHCP != 0 */\r
 985 \r
 986 \r