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

   1 /*\r
   2  * FreeRTOS+TCP V2.0.1\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.\r
  14  *\r
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\r
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS\r
  17  * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR\r
  18  * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER\r
  19  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN\r
  20  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.\r
  21  *\r
  22  * http://www.FreeRTOS.org\r
  23  * http://aws.amazon.com/freertos\r
  24  *\r
  25  * 1 tab == 4 spaces!\r
  26  */\r
  27 \r
  28 /* Standard includes. */\r
  29 #include <stdint.h>\r
  30 \r
  31 /* FreeRTOS includes. */\r
  32 #include "FreeRTOS.h"\r
  33 #include "task.h"\r
  34 #include "semphr.h"\r
  35 \r
  36 /* FreeRTOS+TCP includes. */\r
  37 #include "FreeRTOS_IP.h"\r
  38 #include "FreeRTOS_Sockets.h"\r
  39 #include "FreeRTOS_IP_Private.h"\r
  40 #include "FreeRTOS_UDP_IP.h"\r
  41 #include "FreeRTOS_TCP_IP.h"\r
  42 #include "FreeRTOS_DHCP.h"\r
  43 #include "FreeRTOS_ARP.h"\r
  44 #include "NetworkInterface.h"\r
  45 #include "NetworkBufferManagement.h"\r
  46 \r
  47 /* Exclude the entire file if DHCP is not enabled. */\r
  48 #if( ipconfigUSE_DHCP != 0 )\r
  49 \r
  50 #if ( ipconfigUSE_DHCP != 0 ) && ( ipconfigNETWORK_MTU < 586u )\r
  51         /* DHCP must be able to receive an options field of 312 bytes, the fixed\r
  52         part of the DHCP packet is 240 bytes, and the IP/UDP headers take 28 bytes. */\r
  53         #error ipconfigNETWORK_MTU needs to be at least 586 to use DHCP\r
  54 #endif\r
  55 \r
  56 /* Parameter widths in the DHCP packet. */\r
  57 #define dhcpCLIENT_HARDWARE_ADDRESS_LENGTH              16\r
  58 #define dhcpSERVER_HOST_NAME_LENGTH                             64\r
  59 #define dhcpBOOT_FILE_NAME_LENGTH                               128\r
  60 \r
  61 /* Timer parameters */\r
  62 #ifndef dhcpINITIAL_DHCP_TX_PERIOD\r
  63         #define dhcpINITIAL_TIMER_PERIOD                        ( pdMS_TO_TICKS( 250 ) )\r
  64         #define dhcpINITIAL_DHCP_TX_PERIOD                      ( pdMS_TO_TICKS( 5000 ) )\r
  65 #endif\r
  66 \r
  67 /* Codes of interest found in the DHCP options field. */\r
  68 #define dhcpIPv4_ZERO_PAD_OPTION_CODE                   ( 0u )\r
  69 #define dhcpIPv4_SUBNET_MASK_OPTION_CODE                ( 1u )\r
  70 #define dhcpIPv4_GATEWAY_OPTION_CODE                    ( 3u )\r
  71 #define dhcpIPv4_DNS_SERVER_OPTIONS_CODE                ( 6u )\r
  72 #define dhcpIPv4_DNS_HOSTNAME_OPTIONS_CODE              ( 12u )\r
  73 #define dhcpIPv4_REQUEST_IP_ADDRESS_OPTION_CODE ( 50u )\r
  74 #define dhcpIPv4_LEASE_TIME_OPTION_CODE                 ( 51u )\r
  75 #define dhcpIPv4_MESSAGE_TYPE_OPTION_CODE               ( 53u )\r
  76 #define dhcpIPv4_SERVER_IP_ADDRESS_OPTION_CODE  ( 54u )\r
  77 #define dhcpIPv4_PARAMETER_REQUEST_OPTION_CODE  ( 55u )\r
  78 #define dhcpIPv4_CLIENT_IDENTIFIER_OPTION_CODE  ( 61u )\r
  79 \r
  80 /* The four DHCP message types of interest. */\r
  81 #define dhcpMESSAGE_TYPE_DISCOVER                               ( 1 )\r
  82 #define dhcpMESSAGE_TYPE_OFFER                                  ( 2 )\r
  83 #define dhcpMESSAGE_TYPE_REQUEST                                ( 3 )\r
  84 #define dhcpMESSAGE_TYPE_ACK                                    ( 5 )\r
  85 #define dhcpMESSAGE_TYPE_NACK                                   ( 6 )\r
  86 \r
  87 /* Offsets into the transmitted DHCP options fields at which various parameters\r
  88 are located. */\r
  89 #define dhcpCLIENT_IDENTIFIER_OFFSET                    ( 5 )\r
  90 #define dhcpREQUESTED_IP_ADDRESS_OFFSET                 ( 13 )\r
  91 #define dhcpDHCP_SERVER_IP_ADDRESS_OFFSET               ( 19 )\r
  92 \r
  93 /* Values used in the DHCP packets. */\r
  94 #define dhcpREQUEST_OPCODE                                              ( 1 )\r
  95 #define dhcpREPLY_OPCODE                                                ( 2 )\r
  96 #define dhcpADDRESS_TYPE_ETHERNET                               ( 1 )\r
  97 #define dhcpETHERNET_ADDRESS_LENGTH                             ( 6 )\r
  98 \r
  99 /* If a lease time is not received, use the default of two days. */\r
 100 /* 48 hours in ticks.  Can not use pdMS_TO_TICKS() as integer overflow can occur. */\r
 101 #define dhcpDEFAULT_LEASE_TIME                                  ( ( 48UL * 60UL * 60UL ) * configTICK_RATE_HZ )\r
 102 \r
 103 /* Don't allow the lease time to be too short. */\r
 104 #define dhcpMINIMUM_LEASE_TIME                                  ( pdMS_TO_TICKS( 60000UL ) )    /* 60 seconds in ticks. */\r
 105 \r
 106 /* Marks the end of the variable length options field in the DHCP packet. */\r
 107 #define dhcpOPTION_END_BYTE 0xffu\r
 108 \r
 109 /* Offset into a DHCP message at which the first byte of the options is\r
 110 located. */\r
 111 #define dhcpFIRST_OPTION_BYTE_OFFSET                    ( 0xf0 )\r
 112 \r
 113 /* When walking the variable length options field, the following value is used\r
 114 to ensure the walk has not gone past the end of the valid options.  2 bytes is\r
 115 made up of the length byte, and minimum one byte value. */\r
 116 #define dhcpMAX_OPTION_LENGTH_OF_INTEREST               ( 2L )\r
 117 \r
 118 /* Standard DHCP port numbers and magic cookie value.\r
 119 DHCPv4 uses UDP port number  68 for clients and port number  67 for servers.\r
 120 */\r
 121 #if( ipconfigBYTE_ORDER == pdFREERTOS_LITTLE_ENDIAN )\r
 122         #define dhcpCLIENT_PORT 0x4400u\r
 123         #define dhcpSERVER_PORT 0x4300u\r
 124         #define dhcpCOOKIE              0x63538263ul\r
 125         #define dhcpBROADCAST   0x0080u\r
 126 #else\r
 127         #define dhcpCLIENT_PORT 0x0044u\r
 128         #define dhcpSERVER_PORT 0x0043u\r
 129         #define dhcpCOOKIE              0x63825363ul\r
 130         #define dhcpBROADCAST   0x8000u\r
 131 #endif /* ipconfigBYTE_ORDER */\r
 132 \r
 133 #include "pack_struct_start.h"\r
 134 struct xDHCPMessage\r
 135 {\r
 136         uint8_t ucOpcode;\r
 137         uint8_t ucAddressType;\r
 138         uint8_t ucAddressLength;\r
 139         uint8_t ucHops;\r
 140         uint32_t ulTransactionID;\r
 141         uint16_t usElapsedTime;\r
 142         uint16_t usFlags;\r
 143         uint32_t ulClientIPAddress_ciaddr;\r
 144         uint32_t ulYourIPAddress_yiaddr;\r
 145         uint32_t ulServerIPAddress_siaddr;\r
 146         uint32_t ulRelayAgentIPAddress_giaddr;\r
 147         uint8_t ucClientHardwareAddress[ dhcpCLIENT_HARDWARE_ADDRESS_LENGTH ];\r
 148         uint8_t ucServerHostName[ dhcpSERVER_HOST_NAME_LENGTH ];\r
 149         uint8_t ucBootFileName[ dhcpBOOT_FILE_NAME_LENGTH ];\r
 150         uint32_t ulDHCPCookie;\r
 151         uint8_t ucFirstOptionByte;\r
 152 }\r
 153 #include "pack_struct_end.h"\r
 154 typedef struct xDHCPMessage DHCPMessage_t;\r
 155 \r
 156 /* DHCP state machine states. */\r
 157 typedef enum\r
 158 {\r
 159         eWaitingSendFirstDiscover = 0,  /* Initial state.  Send a discover the first time it is called, and reset all timers. */\r
 160         eWaitingOffer,                                  /* Either resend the discover, or, if the offer is forthcoming, send a request. */\r
 161         eWaitingAcknowledge,                    /* Either resend the request. */\r
 162         #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 163                 eGetLinkLayerAddress,           /* When DHCP didn't respond, try to obtain a LinkLayer address 168.254.x.x. */\r
 164         #endif\r
 165         eLeasedAddress,                                 /* Resend the request at the appropriate time to renew the lease. */\r
 166         eNotUsingLeasedAddress                  /* DHCP failed, and a default IP address is being used. */\r
 167 } eDHCPState_t;\r
 168 \r
 169 /* Hold information in between steps in the DHCP state machine. */\r
 170 struct xDHCP_DATA\r
 171 {\r
 172         uint32_t ulTransactionId;\r
 173         uint32_t ulOfferedIPAddress;\r
 174         uint32_t ulDHCPServerAddress;\r
 175         uint32_t ulLeaseTime;\r
 176         /* Hold information on the current timer state. */\r
 177         TickType_t xDHCPTxTime;\r
 178         TickType_t xDHCPTxPeriod;\r
 179         /* Try both without and with the broadcast flag */\r
 180         BaseType_t xUseBroadcast;\r
 181         /* Maintains the DHCP state machine state. */\r
 182         eDHCPState_t eDHCPState;\r
 183         /* The UDP socket used for all incoming and outgoing DHCP traffic. */\r
 184         Socket_t xDHCPSocket;\r
 185 };\r
 186 \r
 187 typedef struct xDHCP_DATA DHCPData_t;\r
 188 \r
 189 #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 190         /* Define the Link Layer IP address: 169.254.x.x */\r
 191         #define LINK_LAYER_ADDRESS_0    169\r
 192         #define LINK_LAYER_ADDRESS_1    254\r
 193 \r
 194         /* Define the netmask used: 255.255.0.0 */\r
 195         #define LINK_LAYER_NETMASK_0    255\r
 196         #define LINK_LAYER_NETMASK_1    255\r
 197         #define LINK_LAYER_NETMASK_2    0\r
 198         #define LINK_LAYER_NETMASK_3    0\r
 199 #endif\r
 200 \r
 201 \r
 202 /*\r
 203  * Generate a DHCP discover message and send it on the DHCP socket.\r
 204  */\r
 205 static void prvSendDHCPDiscover( void );\r
 206 \r
 207 /*\r
 208  * Interpret message received on the DHCP socket.\r
 209  */\r
 210 static BaseType_t prvProcessDHCPReplies( BaseType_t xExpectedMessageType );\r
 211 \r
 212 /*\r
 213  * Generate a DHCP request packet, and send it on the DHCP socket.\r
 214  */\r
 215 static void prvSendDHCPRequest( void );\r
 216 \r
 217 /*\r
 218  * Prepare to start a DHCP transaction.  This initialises some state variables\r
 219  * and creates the DHCP socket if necessary.\r
 220  */\r
 221 static void prvInitialiseDHCP( void );\r
 222 \r
 223 /*\r
 224  * Creates the part of outgoing DHCP messages that are common to all outgoing\r
 225  * DHCP messages.\r
 226  */\r
 227 static uint8_t *prvCreatePartDHCPMessage( struct freertos_sockaddr *pxAddress, BaseType_t xOpcode, const uint8_t * const pucOptionsArray, size_t *pxOptionsArraySize );\r
 228 \r
 229 /*\r
 230  * Create the DHCP socket, if it has not been created already.\r
 231  */\r
 232 static void prvCreateDHCPSocket( void );\r
 233 \r
 234 /*\r
 235  * After DHCP has failed to answer, prepare everything to start searching\r
 236  * for (trying-out) LinkLayer IP-addresses, using the random method: Send\r
 237  * a gratuitous ARP request and wait if another device responds to it.\r
 238  */\r
 239 #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 240         static void prvPrepareLinkLayerIPLookUp( void );\r
 241 #endif\r
 242 \r
 243 /*-----------------------------------------------------------*/\r
 244 \r
 245 /* The next DHCP transaction Id to be used. */\r
 246 static DHCPData_t xDHCPData;\r
 247 \r
 248 /*-----------------------------------------------------------*/\r
 249 \r
 250 BaseType_t xIsDHCPSocket( Socket_t xSocket )\r
 251 {\r
 252 BaseType_t xReturn;\r
 253 \r
 254         if( xDHCPData.xDHCPSocket == xSocket )\r
 255         {\r
 256                 xReturn = pdTRUE;\r
 257         }\r
 258         else\r
 259         {\r
 260                 xReturn = pdFALSE;\r
 261         }\r
 262 \r
 263         return xReturn;\r
 264 }\r
 265 /*-----------------------------------------------------------*/\r
 266 \r
 267 void vDHCPProcess( BaseType_t xReset )\r
 268 {\r
 269 BaseType_t xGivingUp = pdFALSE;\r
 270 #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 271         eDHCPCallbackAnswer_t eAnswer;\r
 272 #endif  /* ipconfigUSE_DHCP_HOOK */\r
 273 \r
 274         /* Is DHCP starting over? */\r
 275         if( xReset != pdFALSE )\r
 276         {\r
 277                 xDHCPData.eDHCPState = eWaitingSendFirstDiscover;\r
 278         }\r
 279 \r
 280         switch( xDHCPData.eDHCPState )\r
 281         {\r
 282                 case eWaitingSendFirstDiscover :\r
 283                         /* Ask the user if a DHCP discovery is required. */\r
 284                 #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 285                         eAnswer = xApplicationDHCPHook( eDHCPPhasePreDiscover, xNetworkAddressing.ulDefaultIPAddress );\r
 286                         if( eAnswer == eDHCPContinue )\r
 287                 #endif  /* ipconfigUSE_DHCP_HOOK */\r
 288                         {\r
 289                                 /* Initial state.  Create the DHCP socket, timer, etc. if they\r
 290                                 have not already been created. */\r
 291                                 prvInitialiseDHCP();\r
 292 \r
 293                                 /* See if prvInitialiseDHCP() has creates a socket. */\r
 294                                 if( xDHCPData.xDHCPSocket == NULL )\r
 295                                 {\r
 296                                         xGivingUp = pdTRUE;\r
 297                                         break;\r
 298                                 }\r
 299 \r
 300                                 *ipLOCAL_IP_ADDRESS_POINTER = 0UL;\r
 301 \r
 302                                 /* Send the first discover request. */\r
 303                                 if( xDHCPData.xDHCPSocket != NULL )\r
 304                                 {\r
 305                                         xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 306                                         prvSendDHCPDiscover( );\r
 307                                         xDHCPData.eDHCPState = eWaitingOffer;\r
 308                                 }\r
 309                         }\r
 310                 #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 311                         else\r
 312                         {\r
 313                                 if( eAnswer == eDHCPUseDefaults )\r
 314                                 {\r
 315                                         memcpy( &xNetworkAddressing, &xDefaultAddressing, sizeof( xNetworkAddressing ) );\r
 316                                 }\r
 317 \r
 318                                 /* The user indicates that the DHCP process does not continue. */\r
 319                                 xGivingUp = pdTRUE;\r
 320                         }\r
 321                 #endif  /* ipconfigUSE_DHCP_HOOK */\r
 322                         break;\r
 323 \r
 324                 case eWaitingOffer :\r
 325 \r
 326                         xGivingUp = pdFALSE;\r
 327 \r
 328                         /* Look for offers coming in. */\r
 329                         if( prvProcessDHCPReplies( dhcpMESSAGE_TYPE_OFFER ) == pdPASS )\r
 330                         {\r
 331                         #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 332                                 /* Ask the user if a DHCP request is required. */\r
 333                                 eAnswer = xApplicationDHCPHook( eDHCPPhasePreRequest, xDHCPData.ulOfferedIPAddress );\r
 334 \r
 335                                 if( eAnswer == eDHCPContinue )\r
 336                         #endif  /* ipconfigUSE_DHCP_HOOK */\r
 337                                 {\r
 338                                         /* An offer has been made, the user wants to continue,\r
 339                                         generate the request. */\r
 340                                         xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 341                                         xDHCPData.xDHCPTxPeriod = dhcpINITIAL_DHCP_TX_PERIOD;\r
 342                                         prvSendDHCPRequest( );\r
 343                                         xDHCPData.eDHCPState = eWaitingAcknowledge;\r
 344                                         break;\r
 345                                 }\r
 346 \r
 347                         #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 348                                 if( eAnswer == eDHCPUseDefaults )\r
 349                                 {\r
 350                                         memcpy( &xNetworkAddressing, &xDefaultAddressing, sizeof( xNetworkAddressing ) );\r
 351                                 }\r
 352 \r
 353                                 /* The user indicates that the DHCP process does not continue. */\r
 354                                 xGivingUp = pdTRUE;\r
 355                         #endif  /* ipconfigUSE_DHCP_HOOK */\r
 356                         }\r
 357                         else if( ( xTaskGetTickCount() - xDHCPData.xDHCPTxTime ) > xDHCPData.xDHCPTxPeriod )\r
 358                         {\r
 359                                 /* It is time to send another Discover.  Increase the time\r
 360                                 period, and if it has not got to the point of giving up - send\r
 361                                 another discovery. */\r
 362                                 xDHCPData.xDHCPTxPeriod <<= 1;\r
 363 \r
 364                                 if( xDHCPData.xDHCPTxPeriod <= ipconfigMAXIMUM_DISCOVER_TX_PERIOD )\r
 365                                 {\r
 366                                         xDHCPData.ulTransactionId++;\r
 367                                         xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 368                                         xDHCPData.xUseBroadcast = !xDHCPData.xUseBroadcast;\r
 369                                         prvSendDHCPDiscover( );\r
 370                                         FreeRTOS_debug_printf( ( "vDHCPProcess: timeout %lu ticks\n", xDHCPData.xDHCPTxPeriod ) );\r
 371                                 }\r
 372                                 else\r
 373                                 {\r
 374                                         FreeRTOS_debug_printf( ( "vDHCPProcess: giving up %lu > %lu ticks\n", xDHCPData.xDHCPTxPeriod, ipconfigMAXIMUM_DISCOVER_TX_PERIOD ) );\r
 375 \r
 376                                         #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 377                                         {\r
 378                                                 /* Only use a fake Ack if the default IP address == 0x00\r
 379                                                 and the link local addressing is used.  Start searching\r
 380                                                 a free LinkLayer IP-address.  Next state will be\r
 381                                                 'eGetLinkLayerAddress'. */\r
 382                                                 prvPrepareLinkLayerIPLookUp();\r
 383 \r
 384                                                 /* Setting an IP address manually so set to not using\r
 385                                                 leased address mode. */\r
 386                                                 xDHCPData.eDHCPState = eGetLinkLayerAddress;\r
 387                                         }\r
 388                                         #else\r
 389                                         {\r
 390                                                 xGivingUp = pdTRUE;\r
 391                                         }\r
 392                                         #endif /* ipconfigDHCP_FALL_BACK_AUTO_IP */\r
 393                                 }\r
 394                         }\r
 395                         break;\r
 396 \r
 397                 case eWaitingAcknowledge :\r
 398 \r
 399                         /* Look for acks coming in. */\r
 400                         if( prvProcessDHCPReplies( dhcpMESSAGE_TYPE_ACK ) == pdPASS )\r
 401                         {\r
 402                                 FreeRTOS_debug_printf( ( "vDHCPProcess: acked %lxip\n", FreeRTOS_ntohl( xDHCPData.ulOfferedIPAddress ) ) );\r
 403 \r
 404                                 /* DHCP completed.  The IP address can now be used, and the\r
 405                                 timer set to the lease timeout time. */\r
 406                                 *ipLOCAL_IP_ADDRESS_POINTER = xDHCPData.ulOfferedIPAddress;\r
 407 \r
 408                                 /* Setting the 'local' broadcast address, something like\r
 409                                 '192.168.1.255'. */\r
 410                                 xNetworkAddressing.ulBroadcastAddress = ( xDHCPData.ulOfferedIPAddress & xNetworkAddressing.ulNetMask ) |  ~xNetworkAddressing.ulNetMask;\r
 411                                 xDHCPData.eDHCPState = eLeasedAddress;\r
 412 \r
 413                                 iptraceDHCP_SUCCEDEED( xDHCPData.ulOfferedIPAddress );\r
 414 \r
 415                                 /* DHCP failed, the default configured IP-address will be used\r
 416                                 Now call vIPNetworkUpCalls() to send the network-up event and\r
 417                                 start the ARP timer. */\r
 418                                 vIPNetworkUpCalls( );\r
 419 \r
 420                                 /* Close socket to ensure packets don't queue on it. */\r
 421                                 vSocketClose( xDHCPData.xDHCPSocket );\r
 422                                 xDHCPData.xDHCPSocket = NULL;\r
 423 \r
 424                                 if( xDHCPData.ulLeaseTime == 0UL )\r
 425                                 {\r
 426                                         xDHCPData.ulLeaseTime = dhcpDEFAULT_LEASE_TIME;\r
 427                                 }\r
 428                                 else if( xDHCPData.ulLeaseTime < dhcpMINIMUM_LEASE_TIME )\r
 429                                 {\r
 430                                         xDHCPData.ulLeaseTime = dhcpMINIMUM_LEASE_TIME;\r
 431                                 }\r
 432                                 else\r
 433                                 {\r
 434                                         /* The lease time is already valid. */\r
 435                                 }\r
 436 \r
 437                                 /* Check for clashes. */\r
 438                                 vARPSendGratuitous();\r
 439                                 vIPReloadDHCPTimer( xDHCPData.ulLeaseTime );\r
 440                         }\r
 441                         else\r
 442                         {\r
 443                                 /* Is it time to send another Discover? */\r
 444                                 if( ( xTaskGetTickCount() - xDHCPData.xDHCPTxTime ) > xDHCPData.xDHCPTxPeriod )\r
 445                                 {\r
 446                                         /* Increase the time period, and if it has not got to the\r
 447                                         point of giving up - send another request. */\r
 448                                         xDHCPData.xDHCPTxPeriod <<= 1;\r
 449 \r
 450                                         if( xDHCPData.xDHCPTxPeriod <= ipconfigMAXIMUM_DISCOVER_TX_PERIOD )\r
 451                                         {\r
 452                                                 xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 453                                                 prvSendDHCPRequest( );\r
 454                                         }\r
 455                                         else\r
 456                                         {\r
 457                                                 /* Give up, start again. */\r
 458                                                 xDHCPData.eDHCPState = eWaitingSendFirstDiscover;\r
 459                                         }\r
 460                                 }\r
 461                         }\r
 462                         break;\r
 463 \r
 464         #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 465                 case eGetLinkLayerAddress:\r
 466                         if( ( xTaskGetTickCount() - xDHCPData.xDHCPTxTime ) > xDHCPData.xDHCPTxPeriod )\r
 467                         {\r
 468                                 if( xARPHadIPClash == pdFALSE )\r
 469                                 {\r
 470                                         /* ARP OK. proceed. */\r
 471                                         iptraceDHCP_SUCCEDEED( xDHCPData.ulOfferedIPAddress );\r
 472 \r
 473                                         /* Auto-IP succeeded, the default configured IP-address will\r
 474                                         be used.  Now call vIPNetworkUpCalls() to send the\r
 475                                         network-up event and start the ARP timer. */\r
 476                                         vIPNetworkUpCalls( );\r
 477                                         xDHCPData.eDHCPState = eNotUsingLeasedAddress;\r
 478                                 }\r
 479                                 else\r
 480                                 {\r
 481                                         /* ARP clashed - try another IP address. */\r
 482                                         prvPrepareLinkLayerIPLookUp();\r
 483 \r
 484                                         /* Setting an IP address manually so set to not using leased\r
 485                                         address mode. */\r
 486                                         xDHCPData.eDHCPState = eGetLinkLayerAddress;\r
 487                                 }\r
 488                         }\r
 489                         break;\r
 490         #endif  /* ipconfigDHCP_FALL_BACK_AUTO_IP */\r
 491 \r
 492                 case eLeasedAddress :\r
 493 \r
 494                         /* Resend the request at the appropriate time to renew the lease. */\r
 495                         prvCreateDHCPSocket();\r
 496 \r
 497                         if( xDHCPData.xDHCPSocket != NULL )\r
 498                         {\r
 499                                 xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 500                                 xDHCPData.xDHCPTxPeriod = dhcpINITIAL_DHCP_TX_PERIOD;\r
 501                                 prvSendDHCPRequest( );\r
 502                                 xDHCPData.eDHCPState = eWaitingAcknowledge;\r
 503 \r
 504                                 /* From now on, we should be called more often */\r
 505                                 vIPReloadDHCPTimer( dhcpINITIAL_TIMER_PERIOD );\r
 506                         }\r
 507                         break;\r
 508 \r
 509                 case eNotUsingLeasedAddress:\r
 510 \r
 511                         vIPSetDHCPTimerEnableState( pdFALSE );\r
 512                         break;\r
 513 \r
 514                 default:\r
 515                         break;\r
 516         }\r
 517 \r
 518         if( xGivingUp != pdFALSE )\r
 519         {\r
 520                 /* xGivingUp became true either because of a time-out, or because\r
 521                 xApplicationDHCPHook() returned another value than 'eDHCPContinue',\r
 522                 meaning that the conversion is cancelled from here. */\r
 523 \r
 524                 /* Revert to static IP address. */\r
 525                 taskENTER_CRITICAL();\r
 526                 {\r
 527                         *ipLOCAL_IP_ADDRESS_POINTER = xNetworkAddressing.ulDefaultIPAddress;\r
 528                         iptraceDHCP_REQUESTS_FAILED_USING_DEFAULT_IP_ADDRESS( xNetworkAddressing.ulDefaultIPAddress );\r
 529                 }\r
 530                 taskEXIT_CRITICAL();\r
 531 \r
 532                 xDHCPData.eDHCPState = eNotUsingLeasedAddress;\r
 533                 vIPSetDHCPTimerEnableState( pdFALSE );\r
 534 \r
 535                 /* DHCP failed, the default configured IP-address will be used.  Now\r
 536                 call vIPNetworkUpCalls() to send the network-up event and start the ARP\r
 537                 timer. */\r
 538                 vIPNetworkUpCalls( );\r
 539 \r
 540                 /* Test if socket was indeed created. */\r
 541                 if( xDHCPData.xDHCPSocket != NULL )\r
 542                 {\r
 543                         /* Close socket to ensure packets don't queue on it. */\r
 544                         vSocketClose( xDHCPData.xDHCPSocket );\r
 545                         xDHCPData.xDHCPSocket = NULL;\r
 546                 }\r
 547         }\r
 548 }\r
 549 /*-----------------------------------------------------------*/\r
 550 \r
 551 static void prvCreateDHCPSocket( void )\r
 552 {\r
 553 struct freertos_sockaddr xAddress;\r
 554 BaseType_t xReturn;\r
 555 TickType_t xTimeoutTime = ( TickType_t ) 0;\r
 556 \r
 557         /* Create the socket, if it has not already been created. */\r
 558         if( xDHCPData.xDHCPSocket == NULL )\r
 559         {\r
 560                 xDHCPData.xDHCPSocket = FreeRTOS_socket( FREERTOS_AF_INET, FREERTOS_SOCK_DGRAM, FREERTOS_IPPROTO_UDP );\r
 561                 if( xDHCPData.xDHCPSocket != FREERTOS_INVALID_SOCKET )\r
 562                 {\r
 563 \r
 564                         /* Ensure the Rx and Tx timeouts are zero as the DHCP executes in the\r
 565                         context of the IP task. */\r
 566                         FreeRTOS_setsockopt( xDHCPData.xDHCPSocket, 0, FREERTOS_SO_RCVTIMEO, ( void * ) &xTimeoutTime, sizeof( TickType_t ) );\r
 567                         FreeRTOS_setsockopt( xDHCPData.xDHCPSocket, 0, FREERTOS_SO_SNDTIMEO, ( void * ) &xTimeoutTime, sizeof( TickType_t ) );\r
 568 \r
 569                         /* Bind to the standard DHCP client port. */\r
 570                         xAddress.sin_port = ( uint16_t ) dhcpCLIENT_PORT;\r
 571                         xReturn = vSocketBind( xDHCPData.xDHCPSocket, &xAddress, sizeof( xAddress ), pdFALSE );\r
 572                         if( xReturn != 0 )\r
 573                         {\r
 574                                 /* Binding failed, close the socket again. */\r
 575                                 vSocketClose( xDHCPData.xDHCPSocket );\r
 576                                 xDHCPData.xDHCPSocket = NULL;\r
 577                         }\r
 578                 }\r
 579                 else\r
 580                 {\r
 581                         /* Change to NULL for easier testing. */\r
 582                         xDHCPData.xDHCPSocket = NULL;\r
 583                 }\r
 584         }\r
 585 }\r
 586 /*-----------------------------------------------------------*/\r
 587 \r
 588 static void prvInitialiseDHCP( void )\r
 589 {\r
 590         /* Initialise the parameters that will be set by the DHCP process. */\r
 591         if( xDHCPData.ulTransactionId == 0ul )\r
 592         {\r
 593                 xDHCPData.ulTransactionId = ipconfigRAND32();\r
 594         }\r
 595         else\r
 596         {\r
 597                 xDHCPData.ulTransactionId++;\r
 598         }\r
 599 \r
 600         xDHCPData.xUseBroadcast = 0;\r
 601         xDHCPData.ulOfferedIPAddress = 0UL;\r
 602         xDHCPData.ulDHCPServerAddress = 0UL;\r
 603         xDHCPData.xDHCPTxPeriod = dhcpINITIAL_DHCP_TX_PERIOD;\r
 604 \r
 605         /* Create the DHCP socket if it has not already been created. */\r
 606         prvCreateDHCPSocket();\r
 607         FreeRTOS_debug_printf( ( "prvInitialiseDHCP: start after %lu ticks\n", dhcpINITIAL_TIMER_PERIOD ) );\r
 608         vIPReloadDHCPTimer( dhcpINITIAL_TIMER_PERIOD );\r
 609 }\r
 610 /*-----------------------------------------------------------*/\r
 611 \r
 612 static BaseType_t prvProcessDHCPReplies( BaseType_t xExpectedMessageType )\r
 613 {\r
 614 uint8_t *pucUDPPayload, *pucLastByte;\r
 615 struct freertos_sockaddr xClient;\r
 616 uint32_t xClientLength = sizeof( xClient );\r
 617 int32_t lBytes;\r
 618 DHCPMessage_t *pxDHCPMessage;\r
 619 uint8_t *pucByte, ucOptionCode, ucLength;\r
 620 uint32_t ulProcessed, ulParameter;\r
 621 BaseType_t xReturn = pdFALSE;\r
 622 const uint32_t ulMandatoryOptions = 2ul; /* DHCP server address, and the correct DHCP message type must be present in the options. */\r
 623 \r
 624         lBytes = FreeRTOS_recvfrom( xDHCPData.xDHCPSocket, ( void * ) &pucUDPPayload, 0ul, FREERTOS_ZERO_COPY, &xClient, &xClientLength );\r
 625 \r
 626         if( lBytes > 0 )\r
 627         {\r
 628                 /* Map a DHCP structure onto the received data. */\r
 629                 pxDHCPMessage = ( DHCPMessage_t * ) ( pucUDPPayload );\r
 630 \r
 631                 /* Sanity check. */\r
 632                 if( ( pxDHCPMessage->ulDHCPCookie == ( uint32_t ) dhcpCOOKIE ) &&\r
 633                         ( pxDHCPMessage->ucOpcode == ( uint8_t ) dhcpREPLY_OPCODE ) &&\r
 634                         ( pxDHCPMessage->ulTransactionID == FreeRTOS_htonl( xDHCPData.ulTransactionId ) ) )\r
 635                 {\r
 636                         if( memcmp( ( void * ) &( pxDHCPMessage->ucClientHardwareAddress ), ( void * ) ipLOCAL_MAC_ADDRESS, sizeof( MACAddress_t ) ) == 0 )\r
 637                         {\r
 638                                 /* None of the essential options have been processed yet. */\r
 639                                 ulProcessed = 0ul;\r
 640 \r
 641                                 /* Walk through the options until the dhcpOPTION_END_BYTE byte\r
 642                                 is found, taking care not to walk off the end of the options. */\r
 643                                 pucByte = &( pxDHCPMessage->ucFirstOptionByte );\r
 644                                 pucLastByte = &( pucUDPPayload[ lBytes - dhcpMAX_OPTION_LENGTH_OF_INTEREST ] );\r
 645 \r
 646                                 while( pucByte < pucLastByte )\r
 647                                 {\r
 648                                         ucOptionCode = pucByte[ 0 ];\r
 649                                         if( ucOptionCode == ( uint8_t ) dhcpOPTION_END_BYTE )\r
 650                                         {\r
 651                                                 /* Ready, the last byte has been seen. */\r
 652                                                 break;\r
 653                                         }\r
 654                                         if( ucOptionCode == ( uint8_t ) dhcpIPv4_ZERO_PAD_OPTION_CODE )\r
 655                                         {\r
 656                                                 /* The value zero is used as a pad byte,\r
 657                                                 it is not followed by a length byte. */\r
 658                                                 pucByte += 1;\r
 659                                                 continue;\r
 660                                         }\r
 661                                         ucLength = pucByte[ 1 ];\r
 662                                         pucByte += 2;\r
 663 \r
 664                                         /* In most cases, a 4-byte network-endian parameter follows,\r
 665                                         just get it once here and use later */\r
 666                                         memcpy( ( void * ) &( ulParameter ), ( void * ) pucByte, ( size_t ) sizeof( ulParameter ) );\r
 667 \r
 668                                         switch( ucOptionCode )\r
 669                                         {\r
 670                                                 case dhcpIPv4_MESSAGE_TYPE_OPTION_CODE  :\r
 671 \r
 672                                                         if( *pucByte == ( uint8_t ) xExpectedMessageType )\r
 673                                                         {\r
 674                                                                 /* The message type is the message type the\r
 675                                                                 state machine is expecting. */\r
 676                                                                 ulProcessed++;\r
 677                                                         }\r
 678                                                         else\r
 679                                                         {\r
 680                                                                 if( *pucByte == ( uint8_t ) dhcpMESSAGE_TYPE_NACK )\r
 681                                                                 {\r
 682                                                                         if( xExpectedMessageType == ( BaseType_t ) dhcpMESSAGE_TYPE_ACK )\r
 683                                                                         {\r
 684                                                                                 /* Start again. */\r
 685                                                                                 xDHCPData.eDHCPState = eWaitingSendFirstDiscover;\r
 686                                                                         }\r
 687                                                                 }\r
 688                                                                 /* Stop processing further options. */\r
 689                                                                 ucLength = 0;\r
 690                                                         }\r
 691                                                         break;\r
 692 \r
 693                                                 case dhcpIPv4_SUBNET_MASK_OPTION_CODE :\r
 694 \r
 695                                                         if( ucLength == sizeof( uint32_t ) )\r
 696                                                         {\r
 697                                                                 xNetworkAddressing.ulNetMask = ulParameter;\r
 698                                                         }\r
 699                                                         break;\r
 700 \r
 701                                                 case dhcpIPv4_GATEWAY_OPTION_CODE :\r
 702                                                         /* The DHCP server may send more than 1 gateway addresses. */\r
 703                                                         if( ucLength >= sizeof( uint32_t ) )\r
 704                                                         {\r
 705                                                                 /* ulProcessed is not incremented in this case\r
 706                                                                 because the gateway is not essential. */\r
 707                                                                 xNetworkAddressing.ulGatewayAddress = ulParameter;\r
 708                                                         }\r
 709                                                         break;\r
 710 \r
 711                                                 case dhcpIPv4_DNS_SERVER_OPTIONS_CODE :\r
 712 \r
 713                                                         /* ulProcessed is not incremented in this case\r
 714                                                         because the DNS server is not essential.  Only the\r
 715                                                         first DNS server address is taken. */\r
 716                                                         xNetworkAddressing.ulDNSServerAddress = ulParameter;\r
 717                                                         break;\r
 718 \r
 719                                                 case dhcpIPv4_SERVER_IP_ADDRESS_OPTION_CODE :\r
 720 \r
 721                                                         if( ucLength == sizeof( uint32_t ) )\r
 722                                                         {\r
 723                                                                 if( xExpectedMessageType == ( BaseType_t ) dhcpMESSAGE_TYPE_OFFER )\r
 724                                                                 {\r
 725                                                                         /* Offers state the replying server. */\r
 726                                                                         ulProcessed++;\r
 727                                                                         xDHCPData.ulDHCPServerAddress = ulParameter;\r
 728                                                                 }\r
 729                                                                 else\r
 730                                                                 {\r
 731                                                                         /* The ack must come from the expected server. */\r
 732                                                                         if( xDHCPData.ulDHCPServerAddress == ulParameter )\r
 733                                                                         {\r
 734                                                                                 ulProcessed++;\r
 735                                                                         }\r
 736                                                                 }\r
 737                                                         }\r
 738                                                         break;\r
 739 \r
 740                                                 case dhcpIPv4_LEASE_TIME_OPTION_CODE :\r
 741 \r
 742                                                         if( ucLength == sizeof( xDHCPData.ulLeaseTime ) )\r
 743                                                         {\r
 744                                                                 /* ulProcessed is not incremented in this case\r
 745                                                                 because the lease time is not essential. */\r
 746                                                                 /* The DHCP parameter is in seconds, convert\r
 747                                                                 to host-endian format. */\r
 748                                                                 xDHCPData.ulLeaseTime = FreeRTOS_ntohl( ulParameter );\r
 749 \r
 750                                                                 /* Divide the lease time by two to ensure a\r
 751                                                                 renew request is sent before the lease actually\r
 752                                                                 expires. */\r
 753                                                                 xDHCPData.ulLeaseTime >>= 1UL;\r
 754 \r
 755                                                                 /* Multiply with configTICK_RATE_HZ to get clock\r
 756                                                                 ticks. */\r
 757                                                                 xDHCPData.ulLeaseTime = configTICK_RATE_HZ * xDHCPData.ulLeaseTime;\r
 758                                                         }\r
 759                                                         break;\r
 760 \r
 761                                                 default :\r
 762 \r
 763                                                         /* Not interested in this field. */\r
 764 \r
 765                                                         break;\r
 766                                         }\r
 767 \r
 768                                         /* Jump over the data to find the next option code. */\r
 769                                         if( ucLength == 0u )\r
 770                                         {\r
 771                                                 break;\r
 772                                         }\r
 773                                         else\r
 774                                         {\r
 775                                                 pucByte += ucLength;\r
 776                                         }\r
 777                                 }\r
 778 \r
 779                                 /* Were all the mandatory options received? */\r
 780                                 if( ulProcessed >= ulMandatoryOptions )\r
 781                                 {\r
 782                                         /* HT:endian: used to be network order */\r
 783                                         xDHCPData.ulOfferedIPAddress = pxDHCPMessage->ulYourIPAddress_yiaddr;\r
 784                                         FreeRTOS_printf( ( "vDHCPProcess: offer %lxip\n", FreeRTOS_ntohl( xDHCPData.ulOfferedIPAddress ) ) );\r
 785                                         xReturn = pdPASS;\r
 786                                 }\r
 787                         }\r
 788                 }\r
 789 \r
 790                 FreeRTOS_ReleaseUDPPayloadBuffer( ( void * ) pucUDPPayload );\r
 791         } /* if( lBytes > 0 ) */\r
 792 \r
 793         return xReturn;\r
 794 }\r
 795 /*-----------------------------------------------------------*/\r
 796 \r
 797 static uint8_t *prvCreatePartDHCPMessage( struct freertos_sockaddr *pxAddress, BaseType_t xOpcode, const uint8_t * const pucOptionsArray, size_t *pxOptionsArraySize )\r
 798 {\r
 799 DHCPMessage_t *pxDHCPMessage;\r
 800 size_t xRequiredBufferSize = sizeof( DHCPMessage_t ) + *pxOptionsArraySize;\r
 801 uint8_t *pucUDPPayloadBuffer;\r
 802 \r
 803 #if( ipconfigDHCP_REGISTER_HOSTNAME == 1 )\r
 804         const char *pucHostName = pcApplicationHostnameHook ();\r
 805         size_t xNameLength = strlen( pucHostName );\r
 806         uint8_t *pucPtr;\r
 807 \r
 808         xRequiredBufferSize += ( 2 + xNameLength );\r
 809 #endif\r
 810 \r
 811         /* Get a buffer.  This uses a maximum delay, but the delay will be capped\r
 812         to ipconfigUDP_MAX_SEND_BLOCK_TIME_TICKS so the return value still needs to\r
 813         be test. */\r
 814         do\r
 815         {\r
 816         } while( ( pucUDPPayloadBuffer = ( uint8_t * ) FreeRTOS_GetUDPPayloadBuffer( xRequiredBufferSize, portMAX_DELAY ) ) == NULL );\r
 817 \r
 818         pxDHCPMessage = ( DHCPMessage_t * ) pucUDPPayloadBuffer;\r
 819 \r
 820         /* Most fields need to be zero. */\r
 821         memset( ( void * ) pxDHCPMessage, 0x00, sizeof( DHCPMessage_t ) );\r
 822 \r
 823         /* Create the message. */\r
 824         pxDHCPMessage->ucOpcode = ( uint8_t ) xOpcode;\r
 825         pxDHCPMessage->ucAddressType = ( uint8_t ) dhcpADDRESS_TYPE_ETHERNET;\r
 826         pxDHCPMessage->ucAddressLength = ( uint8_t ) dhcpETHERNET_ADDRESS_LENGTH;\r
 827 \r
 828         /* ulTransactionID doesn't really need a htonl() translation, but when DHCP\r
 829         times out, it is nicer to see an increasing number in this ID field */\r
 830         pxDHCPMessage->ulTransactionID = FreeRTOS_htonl( xDHCPData.ulTransactionId );\r
 831         pxDHCPMessage->ulDHCPCookie = ( uint32_t ) dhcpCOOKIE;\r
 832         if( xDHCPData.xUseBroadcast != pdFALSE )\r
 833         {\r
 834                 pxDHCPMessage->usFlags = ( uint16_t ) dhcpBROADCAST;\r
 835         }\r
 836         else\r
 837         {\r
 838                 pxDHCPMessage->usFlags = 0u;\r
 839         }\r
 840 \r
 841         memcpy( ( void * ) &( pxDHCPMessage->ucClientHardwareAddress[ 0 ] ), ( void * ) ipLOCAL_MAC_ADDRESS, sizeof( MACAddress_t ) );\r
 842 \r
 843         /* Copy in the const part of the options options. */\r
 844         memcpy( ( void * ) &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET ] ), ( void * ) pucOptionsArray, *pxOptionsArraySize );\r
 845 \r
 846         #if( ipconfigDHCP_REGISTER_HOSTNAME == 1 )\r
 847         {\r
 848                 /* With this option, the hostname can be registered as well which makes\r
 849                 it easier to lookup a device in a router's list of DHCP clients. */\r
 850 \r
 851                 /* Point to where the OPTION_END was stored to add data. */\r
 852                 pucPtr = &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET + ( *pxOptionsArraySize - 1 ) ] );\r
 853                 pucPtr[ 0 ] = dhcpIPv4_DNS_HOSTNAME_OPTIONS_CODE;\r
 854                 pucPtr[ 1 ] = ( uint8_t ) xNameLength;\r
 855                 memcpy( ( void *) ( pucPtr + 2 ), pucHostName, xNameLength );\r
 856                 pucPtr[ 2 + xNameLength ] = dhcpOPTION_END_BYTE;\r
 857                 *pxOptionsArraySize += ( 2 + xNameLength );\r
 858         }\r
 859         #endif\r
 860 \r
 861         /* Map in the client identifier. */\r
 862         memcpy( ( void * ) &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET + dhcpCLIENT_IDENTIFIER_OFFSET ] ),\r
 863                 ( void * ) ipLOCAL_MAC_ADDRESS, sizeof( MACAddress_t ) );\r
 864 \r
 865         /* Set the addressing. */\r
 866         pxAddress->sin_addr = ipBROADCAST_IP_ADDRESS;\r
 867         pxAddress->sin_port = ( uint16_t ) dhcpSERVER_PORT;\r
 868 \r
 869         return pucUDPPayloadBuffer;\r
 870 }\r
 871 /*-----------------------------------------------------------*/\r
 872 \r
 873 static void prvSendDHCPRequest( void )\r
 874 {\r
 875 uint8_t *pucUDPPayloadBuffer;\r
 876 struct freertos_sockaddr xAddress;\r
 877 static const uint8_t ucDHCPRequestOptions[] =\r
 878 {\r
 879         /* Do not change the ordering without also changing\r
 880         dhcpCLIENT_IDENTIFIER_OFFSET, dhcpREQUESTED_IP_ADDRESS_OFFSET and\r
 881         dhcpDHCP_SERVER_IP_ADDRESS_OFFSET. */\r
 882         dhcpIPv4_MESSAGE_TYPE_OPTION_CODE, 1, dhcpMESSAGE_TYPE_REQUEST,         /* Message type option. */\r
 883         dhcpIPv4_CLIENT_IDENTIFIER_OPTION_CODE, 6, 0, 0, 0, 0, 0, 0,                    /* Client identifier. */\r
 884         dhcpIPv4_REQUEST_IP_ADDRESS_OPTION_CODE, 4, 0, 0, 0, 0,                         /* The IP address being requested. */\r
 885         dhcpIPv4_SERVER_IP_ADDRESS_OPTION_CODE, 4, 0, 0, 0, 0,                          /* The IP address of the DHCP server. */\r
 886         dhcpOPTION_END_BYTE\r
 887 };\r
 888 size_t xOptionsLength = sizeof( ucDHCPRequestOptions );\r
 889 \r
 890         pucUDPPayloadBuffer = prvCreatePartDHCPMessage( &xAddress, ( uint8_t ) dhcpREQUEST_OPCODE, ucDHCPRequestOptions, &xOptionsLength );\r
 891 \r
 892         /* Copy in the IP address being requested. */\r
 893         memcpy( ( void * ) &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET + dhcpREQUESTED_IP_ADDRESS_OFFSET ] ),\r
 894                 ( void * ) &( xDHCPData.ulOfferedIPAddress ), sizeof( xDHCPData.ulOfferedIPAddress ) );\r
 895 \r
 896         /* Copy in the address of the DHCP server being used. */\r
 897         memcpy( ( void * ) &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET + dhcpDHCP_SERVER_IP_ADDRESS_OFFSET ] ),\r
 898                 ( void * ) &( xDHCPData.ulDHCPServerAddress ), sizeof( xDHCPData.ulDHCPServerAddress ) );\r
 899 \r
 900         FreeRTOS_debug_printf( ( "vDHCPProcess: reply %lxip\n", FreeRTOS_ntohl( xDHCPData.ulOfferedIPAddress ) ) );\r
 901         iptraceSENDING_DHCP_REQUEST();\r
 902 \r
 903         if( FreeRTOS_sendto( xDHCPData.xDHCPSocket, pucUDPPayloadBuffer, ( sizeof( DHCPMessage_t ) + xOptionsLength ), FREERTOS_ZERO_COPY, &xAddress, sizeof( xAddress ) ) == 0 )\r
 904         {\r
 905                 /* The packet was not successfully queued for sending and must be\r
 906                 returned to the stack. */\r
 907                 FreeRTOS_ReleaseUDPPayloadBuffer( pucUDPPayloadBuffer );\r
 908         }\r
 909 }\r
 910 /*-----------------------------------------------------------*/\r
 911 \r
 912 static void prvSendDHCPDiscover( void )\r
 913 {\r
 914 uint8_t *pucUDPPayloadBuffer;\r
 915 struct freertos_sockaddr xAddress;\r
 916 static const uint8_t ucDHCPDiscoverOptions[] =\r
 917 {\r
 918         /* Do not change the ordering without also changing dhcpCLIENT_IDENTIFIER_OFFSET. */\r
 919         dhcpIPv4_MESSAGE_TYPE_OPTION_CODE, 1, dhcpMESSAGE_TYPE_DISCOVER,                                        /* Message type option. */\r
 920         dhcpIPv4_CLIENT_IDENTIFIER_OPTION_CODE, 6, 0, 0, 0, 0, 0, 0,                                            /* Client identifier. */\r
 921         dhcpIPv4_PARAMETER_REQUEST_OPTION_CODE, 3, dhcpIPv4_SUBNET_MASK_OPTION_CODE, dhcpIPv4_GATEWAY_OPTION_CODE, dhcpIPv4_DNS_SERVER_OPTIONS_CODE,    /* Parameter request option. */\r
 922         dhcpOPTION_END_BYTE\r
 923 };\r
 924 size_t xOptionsLength = sizeof( ucDHCPDiscoverOptions );\r
 925 \r
 926         pucUDPPayloadBuffer = prvCreatePartDHCPMessage( &xAddress, ( uint8_t ) dhcpREQUEST_OPCODE, ucDHCPDiscoverOptions, &xOptionsLength );\r
 927 \r
 928         FreeRTOS_debug_printf( ( "vDHCPProcess: discover\n" ) );\r
 929         iptraceSENDING_DHCP_DISCOVER();\r
 930 \r
 931         if( FreeRTOS_sendto( xDHCPData.xDHCPSocket, pucUDPPayloadBuffer, ( sizeof( DHCPMessage_t ) + xOptionsLength ), FREERTOS_ZERO_COPY, &xAddress, sizeof( xAddress ) ) == 0 )\r
 932         {\r
 933                 /* The packet was not successfully queued for sending and must be\r
 934                 returned to the stack. */\r
 935                 FreeRTOS_ReleaseUDPPayloadBuffer( pucUDPPayloadBuffer );\r
 936         }\r
 937 }\r
 938 /*-----------------------------------------------------------*/\r
 939 \r
 940 #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 941 \r
 942         static void prvPrepareLinkLayerIPLookUp( void )\r
 943         {\r
 944         uint8_t ucLinkLayerIPAddress[ 2 ];\r
 945 \r
 946                 /* After DHCP has failed to answer, prepare everything to start\r
 947                 trying-out LinkLayer IP-addresses, using the random method. */\r
 948                 xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 949 \r
 950                 ucLinkLayerIPAddress[ 0 ] = ( uint8_t )1 + ( uint8_t )( ipconfigRAND32() % 0xFDu );             /* get value 1..254 for IP-address 3rd byte of IP address to try. */\r
 951                 ucLinkLayerIPAddress[ 1 ] = ( uint8_t )1 + ( uint8_t )( ipconfigRAND32() % 0xFDu );             /* get value 1..254 for IP-address 4th byte of IP address to try. */\r
 952 \r
 953                 xNetworkAddressing.ulGatewayAddress = FreeRTOS_htonl( 0xA9FE0203 );\r
 954 \r
 955                 /* prepare xDHCPData with data to test. */\r
 956                 xDHCPData.ulOfferedIPAddress =\r
 957                         FreeRTOS_inet_addr_quick( LINK_LAYER_ADDRESS_0, LINK_LAYER_ADDRESS_1, ucLinkLayerIPAddress[ 0 ], ucLinkLayerIPAddress[ 1 ] );\r
 958 \r
 959                 xDHCPData.ulLeaseTime = dhcpDEFAULT_LEASE_TIME;  /*  don't care about lease time. just put anything. */\r
 960 \r
 961                 xNetworkAddressing.ulNetMask =\r
 962                         FreeRTOS_inet_addr_quick( LINK_LAYER_NETMASK_0, LINK_LAYER_NETMASK_1, LINK_LAYER_NETMASK_2, LINK_LAYER_NETMASK_3 );\r
 963 \r
 964                 /* DHCP completed.  The IP address can now be used, and the\r
 965                 timer set to the lease timeout time. */\r
 966                 *ipLOCAL_IP_ADDRESS_POINTER = xDHCPData.ulOfferedIPAddress;\r
 967 \r
 968                 /* Setting the 'local' broadcast address, something like 192.168.1.255' */\r
 969                 xNetworkAddressing.ulBroadcastAddress = ( xDHCPData.ulOfferedIPAddress & xNetworkAddressing.ulNetMask ) |  ~xNetworkAddressing.ulNetMask;\r
 970 \r
 971                 /* Close socket to ensure packets don't queue on it. not needed anymore as DHCP failed. but still need timer for ARP testing. */\r
 972                 vSocketClose( xDHCPData.xDHCPSocket );\r
 973                 xDHCPData.xDHCPSocket = NULL;\r
 974                 xDHCPData.xDHCPTxPeriod = pdMS_TO_TICKS( 3000ul + ( ipconfigRAND32() & 0x3fful ) ); /*  do ARP test every (3 + 0-1024mS) seconds. */\r
 975 \r
 976                 xARPHadIPClash = pdFALSE;          /* reset flag that shows if have ARP clash. */\r
 977                 vARPSendGratuitous();\r
 978         }\r
 979 \r
 980 #endif /* ipconfigDHCP_FALL_BACK_AUTO_IP */\r
 981 /*-----------------------------------------------------------*/\r
 982 \r
 983 #endif /* ipconfigUSE_DHCP != 0 */\r
 984 \r
 985 \r