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

   1 /*\r
   2  * FreeRTOS+TCP V2.0.7\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://aws.amazon.com/freertos\r
  23  * http://www.FreeRTOS.org\r
  24  */\r
  25 \r
  26 /* Standard includes. */\r
  27 #include <stdint.h>\r
  28 \r
  29 /* FreeRTOS includes. */\r
  30 #include "FreeRTOS.h"\r
  31 #include "task.h"\r
  32 #include "semphr.h"\r
  33 \r
  34 /* FreeRTOS+TCP includes. */\r
  35 #include "FreeRTOS_IP.h"\r
  36 #include "FreeRTOS_Sockets.h"\r
  37 #include "FreeRTOS_IP_Private.h"\r
  38 #include "FreeRTOS_UDP_IP.h"\r
  39 #include "FreeRTOS_TCP_IP.h"\r
  40 #include "FreeRTOS_DHCP.h"\r
  41 #include "FreeRTOS_ARP.h"\r
  42 #include "NetworkInterface.h"\r
  43 #include "NetworkBufferManagement.h"\r
  44 \r
  45 /* Exclude the entire file if DHCP is not enabled. */\r
  46 #if( ipconfigUSE_DHCP != 0 )\r
  47 \r
  48 #if ( ipconfigUSE_DHCP != 0 ) && ( ipconfigNETWORK_MTU < 586u )\r
  49         /* DHCP must be able to receive an options field of 312 bytes, the fixed\r
  50         part of the DHCP packet is 240 bytes, and the IP/UDP headers take 28 bytes. */\r
  51         #error ipconfigNETWORK_MTU needs to be at least 586 to use DHCP\r
  52 #endif\r
  53 \r
  54 /* Parameter widths in the DHCP packet. */\r
  55 #define dhcpCLIENT_HARDWARE_ADDRESS_LENGTH              16\r
  56 #define dhcpSERVER_HOST_NAME_LENGTH                             64\r
  57 #define dhcpBOOT_FILE_NAME_LENGTH                               128\r
  58 \r
  59 /* Timer parameters */\r
  60 #ifndef dhcpINITIAL_DHCP_TX_PERIOD\r
  61         #define dhcpINITIAL_TIMER_PERIOD                        ( pdMS_TO_TICKS( 250 ) )\r
  62         #define dhcpINITIAL_DHCP_TX_PERIOD                      ( pdMS_TO_TICKS( 5000 ) )\r
  63 #endif\r
  64 \r
  65 /* Codes of interest found in the DHCP options field. */\r
  66 #define dhcpZERO_PAD_OPTION_CODE                                ( 0u )\r
  67 #define dhcpSUBNET_MASK_OPTION_CODE                             ( 1u )\r
  68 #define dhcpGATEWAY_OPTION_CODE                                 ( 3u )\r
  69 #define dhcpDNS_SERVER_OPTIONS_CODE                             ( 6u )\r
  70 #define dhcpDNS_HOSTNAME_OPTIONS_CODE                   ( 12u )\r
  71 #define dhcpREQUEST_IP_ADDRESS_OPTION_CODE              ( 50u )\r
  72 #define dhcpLEASE_TIME_OPTION_CODE                              ( 51u )\r
  73 #define dhcpMESSAGE_TYPE_OPTION_CODE                    ( 53u )\r
  74 #define dhcpSERVER_IP_ADDRESS_OPTION_CODE               ( 54u )\r
  75 #define dhcpPARAMETER_REQUEST_OPTION_CODE               ( 55u )\r
  76 #define dhcpCLIENT_IDENTIFIER_OPTION_CODE               ( 61u )\r
  77 \r
  78 /* The four DHCP message types of interest. */\r
  79 #define dhcpMESSAGE_TYPE_DISCOVER                               ( 1 )\r
  80 #define dhcpMESSAGE_TYPE_OFFER                                  ( 2 )\r
  81 #define dhcpMESSAGE_TYPE_REQUEST                                ( 3 )\r
  82 #define dhcpMESSAGE_TYPE_ACK                                    ( 5 )\r
  83 #define dhcpMESSAGE_TYPE_NACK                                   ( 6 )\r
  84 \r
  85 /* Offsets into the transmitted DHCP options fields at which various parameters\r
  86 are located. */\r
  87 #define dhcpCLIENT_IDENTIFIER_OFFSET                    ( 5 )\r
  88 #define dhcpREQUESTED_IP_ADDRESS_OFFSET                 ( 13 )\r
  89 #define dhcpDHCP_SERVER_IP_ADDRESS_OFFSET               ( 19 )\r
  90 \r
  91 /* Values used in the DHCP packets. */\r
  92 #define dhcpREQUEST_OPCODE                                              ( 1 )\r
  93 #define dhcpREPLY_OPCODE                                                ( 2 )\r
  94 #define dhcpADDRESS_TYPE_ETHERNET                               ( 1 )\r
  95 #define dhcpETHERNET_ADDRESS_LENGTH                             ( 6 )\r
  96 \r
  97 /* If a lease time is not received, use the default of two days. */\r
  98 /* 48 hours in ticks.  Can not use pdMS_TO_TICKS() as integer overflow can occur. */\r
  99 #define dhcpDEFAULT_LEASE_TIME                                  ( ( 48UL * 60UL * 60UL ) * configTICK_RATE_HZ )\r
 100 \r
 101 /* Don't allow the lease time to be too short. */\r
 102 #define dhcpMINIMUM_LEASE_TIME                                  ( pdMS_TO_TICKS( 60000UL ) )    /* 60 seconds in ticks. */\r
 103 \r
 104 /* Marks the end of the variable length options field in the DHCP packet. */\r
 105 #define dhcpOPTION_END_BYTE 0xffu\r
 106 \r
 107 /* Offset into a DHCP message at which the first byte of the options is\r
 108 located. */\r
 109 #define dhcpFIRST_OPTION_BYTE_OFFSET                    ( 0xf0 )\r
 110 \r
 111 /* When walking the variable length options field, the following value is used\r
 112 to ensure the walk has not gone past the end of the valid options.  2 bytes is\r
 113 made up of the length byte, and minimum one byte value. */\r
 114 #define dhcpMAX_OPTION_LENGTH_OF_INTEREST               ( 2L )\r
 115 \r
 116 /* Standard DHCP port numbers and magic cookie value. */\r
 117 #if( ipconfigBYTE_ORDER == pdFREERTOS_LITTLE_ENDIAN )\r
 118         #define dhcpCLIENT_PORT 0x4400u\r
 119         #define dhcpSERVER_PORT 0x4300u\r
 120         #define dhcpCOOKIE              0x63538263ul\r
 121         #define dhcpBROADCAST   0x0080u\r
 122 #else\r
 123         #define dhcpCLIENT_PORT 0x0044u\r
 124         #define dhcpSERVER_PORT 0x0043u\r
 125         #define dhcpCOOKIE              0x63825363ul\r
 126         #define dhcpBROADCAST   0x8000u\r
 127 #endif /* ipconfigBYTE_ORDER */\r
 128 \r
 129 #include "pack_struct_start.h"\r
 130 struct xDHCPMessage\r
 131 {\r
 132         uint8_t ucOpcode;\r
 133         uint8_t ucAddressType;\r
 134         uint8_t ucAddressLength;\r
 135         uint8_t ucHops;\r
 136         uint32_t ulTransactionID;\r
 137         uint16_t usElapsedTime;\r
 138         uint16_t usFlags;\r
 139         uint32_t ulClientIPAddress_ciaddr;\r
 140         uint32_t ulYourIPAddress_yiaddr;\r
 141         uint32_t ulServerIPAddress_siaddr;\r
 142         uint32_t ulRelayAgentIPAddress_giaddr;\r
 143         uint8_t ucClientHardwareAddress[ dhcpCLIENT_HARDWARE_ADDRESS_LENGTH ];\r
 144         uint8_t ucServerHostName[ dhcpSERVER_HOST_NAME_LENGTH ];\r
 145         uint8_t ucBootFileName[ dhcpBOOT_FILE_NAME_LENGTH ];\r
 146         uint32_t ulDHCPCookie;\r
 147         uint8_t ucFirstOptionByte;\r
 148 }\r
 149 #include "pack_struct_end.h"\r
 150 typedef struct xDHCPMessage DHCPMessage_t;\r
 151 \r
 152 /* DHCP state machine states. */\r
 153 typedef enum\r
 154 {\r
 155         eWaitingSendFirstDiscover = 0,  /* Initial state.  Send a discover the first time it is called, and reset all timers. */\r
 156         eWaitingOffer,                                  /* Either resend the discover, or, if the offer is forthcoming, send a request. */\r
 157         eWaitingAcknowledge,                    /* Either resend the request. */\r
 158         #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 159                 eGetLinkLayerAddress,           /* When DHCP didn't respond, try to obtain a LinkLayer address 168.254.x.x. */\r
 160         #endif\r
 161         eLeasedAddress,                                 /* Resend the request at the appropriate time to renew the lease. */\r
 162         eNotUsingLeasedAddress                  /* DHCP failed, and a default IP address is being used. */\r
 163 } eDHCPState_t;\r
 164 \r
 165 /* Hold information in between steps in the DHCP state machine. */\r
 166 struct xDHCP_DATA\r
 167 {\r
 168         uint32_t ulTransactionId;\r
 169         uint32_t ulOfferedIPAddress;\r
 170         uint32_t ulDHCPServerAddress;\r
 171         uint32_t ulLeaseTime;\r
 172         /* Hold information on the current timer state. */\r
 173         TickType_t xDHCPTxTime;\r
 174         TickType_t xDHCPTxPeriod;\r
 175         /* Try both without and with the broadcast flag */\r
 176         BaseType_t xUseBroadcast;\r
 177         /* Maintains the DHCP state machine state. */\r
 178         eDHCPState_t eDHCPState;\r
 179         /* The UDP socket used for all incoming and outgoing DHCP traffic. */\r
 180         Socket_t xDHCPSocket;\r
 181 };\r
 182 \r
 183 typedef struct xDHCP_DATA DHCPData_t;\r
 184 \r
 185 #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 186         /* Define the Link Layer IP address: 169.254.x.x */\r
 187         #define LINK_LAYER_ADDRESS_0    169\r
 188         #define LINK_LAYER_ADDRESS_1    254\r
 189 \r
 190         /* Define the netmask used: 255.255.0.0 */\r
 191         #define LINK_LAYER_NETMASK_0    255\r
 192         #define LINK_LAYER_NETMASK_1    255\r
 193         #define LINK_LAYER_NETMASK_2    0\r
 194         #define LINK_LAYER_NETMASK_3    0\r
 195 #endif\r
 196 \r
 197 \r
 198 /*\r
 199  * Generate a DHCP discover message and send it on the DHCP socket.\r
 200  */\r
 201 static void prvSendDHCPDiscover( void );\r
 202 \r
 203 /*\r
 204  * Interpret message received on the DHCP socket.\r
 205  */\r
 206 static BaseType_t prvProcessDHCPReplies( BaseType_t xExpectedMessageType );\r
 207 \r
 208 /*\r
 209  * Generate a DHCP request packet, and send it on the DHCP socket.\r
 210  */\r
 211 static void prvSendDHCPRequest( void );\r
 212 \r
 213 /*\r
 214  * Prepare to start a DHCP transaction.  This initialises some state variables\r
 215  * and creates the DHCP socket if necessary.\r
 216  */\r
 217 static void prvInitialiseDHCP( void );\r
 218 \r
 219 /*\r
 220  * Creates the part of outgoing DHCP messages that are common to all outgoing\r
 221  * DHCP messages.\r
 222  */\r
 223 static uint8_t *prvCreatePartDHCPMessage( struct freertos_sockaddr *pxAddress, BaseType_t xOpcode, const uint8_t * const pucOptionsArray, size_t *pxOptionsArraySize );\r
 224 \r
 225 /*\r
 226  * Create the DHCP socket, if it has not been created already.\r
 227  */\r
 228 static void prvCreateDHCPSocket( void );\r
 229 \r
 230 /*\r
 231  * After DHCP has failed to answer, prepare everything to start searching\r
 232  * for (trying-out) LinkLayer IP-addresses, using the random method: Send\r
 233  * a gratuitous ARP request and wait if another device responds to it.\r
 234  */\r
 235 #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 236         static void prvPrepareLinkLayerIPLookUp( void );\r
 237 #endif\r
 238 \r
 239 /*-----------------------------------------------------------*/\r
 240 \r
 241 /* The next DHCP transaction Id to be used. */\r
 242 static DHCPData_t xDHCPData;\r
 243 \r
 244 /*-----------------------------------------------------------*/\r
 245 \r
 246 BaseType_t xIsDHCPSocket( Socket_t xSocket )\r
 247 {\r
 248 BaseType_t xReturn;\r
 249 \r
 250         if( xDHCPData.xDHCPSocket == xSocket )\r
 251         {\r
 252                 xReturn = pdTRUE;\r
 253         }\r
 254         else\r
 255         {\r
 256                 xReturn = pdFALSE;\r
 257         }\r
 258 \r
 259         return xReturn;\r
 260 }\r
 261 /*-----------------------------------------------------------*/\r
 262 \r
 263 void vDHCPProcess( BaseType_t xReset )\r
 264 {\r
 265 BaseType_t xGivingUp = pdFALSE;\r
 266 #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 267         eDHCPCallbackAnswer_t eAnswer;\r
 268 #endif  /* ipconfigUSE_DHCP_HOOK */\r
 269 \r
 270         /* Is DHCP starting over? */\r
 271         if( xReset != pdFALSE )\r
 272         {\r
 273                 xDHCPData.eDHCPState = eWaitingSendFirstDiscover;\r
 274         }\r
 275 \r
 276         switch( xDHCPData.eDHCPState )\r
 277         {\r
 278                 case eWaitingSendFirstDiscover :\r
 279                         /* Ask the user if a DHCP discovery is required. */\r
 280                 #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 281                         eAnswer = xApplicationDHCPHook( eDHCPPhasePreDiscover, xNetworkAddressing.ulDefaultIPAddress );\r
 282                         if( eAnswer == eDHCPContinue )\r
 283                 #endif  /* ipconfigUSE_DHCP_HOOK */\r
 284                         {\r
 285                                 /* Initial state.  Create the DHCP socket, timer, etc. if they\r
 286                                 have not already been created. */\r
 287                                 prvInitialiseDHCP();\r
 288 \r
 289                                 /* See if prvInitialiseDHCP() has creates a socket. */\r
 290                                 if( xDHCPData.xDHCPSocket == NULL )\r
 291                                 {\r
 292                                         xGivingUp = pdTRUE;\r
 293                                         break;\r
 294                                 }\r
 295 \r
 296                                 *ipLOCAL_IP_ADDRESS_POINTER = 0UL;\r
 297 \r
 298                                 /* Send the first discover request. */\r
 299                                 if( xDHCPData.xDHCPSocket != NULL )\r
 300                                 {\r
 301                                         xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 302                                         prvSendDHCPDiscover( );\r
 303                                         xDHCPData.eDHCPState = eWaitingOffer;\r
 304                                 }\r
 305                         }\r
 306                 #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 307                         else\r
 308                         {\r
 309                                 if( eAnswer == eDHCPUseDefaults )\r
 310                                 {\r
 311                                         memcpy( &xNetworkAddressing, &xDefaultAddressing, sizeof( xNetworkAddressing ) );\r
 312                                 }\r
 313 \r
 314                                 /* The user indicates that the DHCP process does not continue. */\r
 315                                 xGivingUp = pdTRUE;\r
 316                         }\r
 317                 #endif  /* ipconfigUSE_DHCP_HOOK */\r
 318                         break;\r
 319 \r
 320                 case eWaitingOffer :\r
 321 \r
 322                         xGivingUp = pdFALSE;\r
 323 \r
 324                         /* Look for offers coming in. */\r
 325                         if( prvProcessDHCPReplies( dhcpMESSAGE_TYPE_OFFER ) == pdPASS )\r
 326                         {\r
 327                         #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 328                                 /* Ask the user if a DHCP request is required. */\r
 329                                 eAnswer = xApplicationDHCPHook( eDHCPPhasePreRequest, xDHCPData.ulOfferedIPAddress );\r
 330 \r
 331                                 if( eAnswer == eDHCPContinue )\r
 332                         #endif  /* ipconfigUSE_DHCP_HOOK */\r
 333                                 {\r
 334                                         /* An offer has been made, the user wants to continue,\r
 335                                         generate the request. */\r
 336                                         xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 337                                         xDHCPData.xDHCPTxPeriod = dhcpINITIAL_DHCP_TX_PERIOD;\r
 338                                         prvSendDHCPRequest( );\r
 339                                         xDHCPData.eDHCPState = eWaitingAcknowledge;\r
 340                                         break;\r
 341                                 }\r
 342 \r
 343                         #if( ipconfigUSE_DHCP_HOOK != 0 )\r
 344                                 if( eAnswer == eDHCPUseDefaults )\r
 345                                 {\r
 346                                         memcpy( &xNetworkAddressing, &xDefaultAddressing, sizeof( xNetworkAddressing ) );\r
 347                                 }\r
 348 \r
 349                                 /* The user indicates that the DHCP process does not continue. */\r
 350                                 xGivingUp = pdTRUE;\r
 351                         #endif  /* ipconfigUSE_DHCP_HOOK */\r
 352                         }\r
 353                         else if( ( xTaskGetTickCount() - xDHCPData.xDHCPTxTime ) > xDHCPData.xDHCPTxPeriod )\r
 354                         {\r
 355                                 /* It is time to send another Discover.  Increase the time\r
 356                                 period, and if it has not got to the point of giving up - send\r
 357                                 another discovery. */\r
 358                                 xDHCPData.xDHCPTxPeriod <<= 1;\r
 359 \r
 360                                 if( xDHCPData.xDHCPTxPeriod <= ipconfigMAXIMUM_DISCOVER_TX_PERIOD )\r
 361                                 {\r
 362                                         xDHCPData.ulTransactionId = ipconfigRAND32( );\r
 363 \r
 364                                         if( 0 != xDHCPData.ulTransactionId )\r
 365                                         {\r
 366                                                 xDHCPData.xDHCPTxTime = xTaskGetTickCount( );\r
 367                                                 xDHCPData.xUseBroadcast = !xDHCPData.xUseBroadcast;\r
 368                                                 prvSendDHCPDiscover( );\r
 369                                                 FreeRTOS_debug_printf( ( "vDHCPProcess: timeout %lu ticks\n", xDHCPData.xDHCPTxPeriod ) );\r
 370                                         }\r
 371                                         else\r
 372                                         {\r
 373                                                 FreeRTOS_debug_printf( ( "vDHCPProcess: failed to generate a random Transaction ID\n" ) );\r
 374                                         }\r
 375                                 }\r
 376                                 else\r
 377                                 {\r
 378                                         FreeRTOS_debug_printf( ( "vDHCPProcess: giving up %lu > %lu ticks\n", xDHCPData.xDHCPTxPeriod, ipconfigMAXIMUM_DISCOVER_TX_PERIOD ) );\r
 379 \r
 380                                         #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 381                                         {\r
 382                                                 /* Only use a fake Ack if the default IP address == 0x00\r
 383                                                 and the link local addressing is used.  Start searching\r
 384                                                 a free LinkLayer IP-address.  Next state will be\r
 385                                                 'eGetLinkLayerAddress'. */\r
 386                                                 prvPrepareLinkLayerIPLookUp();\r
 387 \r
 388                                                 /* Setting an IP address manually so set to not using\r
 389                                                 leased address mode. */\r
 390                                                 xDHCPData.eDHCPState = eGetLinkLayerAddress;\r
 391                                         }\r
 392                                         #else\r
 393                                         {\r
 394                                                 xGivingUp = pdTRUE;\r
 395                                         }\r
 396                                         #endif /* ipconfigDHCP_FALL_BACK_AUTO_IP */\r
 397                                 }\r
 398                         }\r
 399                         break;\r
 400 \r
 401                 case eWaitingAcknowledge :\r
 402 \r
 403                         /* Look for acks coming in. */\r
 404                         if( prvProcessDHCPReplies( dhcpMESSAGE_TYPE_ACK ) == pdPASS )\r
 405                         {\r
 406                                 FreeRTOS_debug_printf( ( "vDHCPProcess: acked %lxip\n", FreeRTOS_ntohl( xDHCPData.ulOfferedIPAddress ) ) );\r
 407 \r
 408                                 /* DHCP completed.  The IP address can now be used, and the\r
 409                                 timer set to the lease timeout time. */\r
 410                                 *ipLOCAL_IP_ADDRESS_POINTER = xDHCPData.ulOfferedIPAddress;\r
 411 \r
 412                                 /* Setting the 'local' broadcast address, something like\r
 413                                 '192.168.1.255'. */\r
 414                                 xNetworkAddressing.ulBroadcastAddress = ( xDHCPData.ulOfferedIPAddress & xNetworkAddressing.ulNetMask ) |  ~xNetworkAddressing.ulNetMask;\r
 415                                 xDHCPData.eDHCPState = eLeasedAddress;\r
 416 \r
 417                                 iptraceDHCP_SUCCEDEED( xDHCPData.ulOfferedIPAddress );\r
 418 \r
 419                                 /* DHCP failed, the default configured IP-address will be used\r
 420                                 Now call vIPNetworkUpCalls() to send the network-up event and\r
 421                                 start the ARP timer. */\r
 422                                 vIPNetworkUpCalls( );\r
 423 \r
 424                                 /* Close socket to ensure packets don't queue on it. */\r
 425                                 vSocketClose( xDHCPData.xDHCPSocket );\r
 426                                 xDHCPData.xDHCPSocket = NULL;\r
 427 \r
 428                                 if( xDHCPData.ulLeaseTime == 0UL )\r
 429                                 {\r
 430                                         xDHCPData.ulLeaseTime = dhcpDEFAULT_LEASE_TIME;\r
 431                                 }\r
 432                                 else if( xDHCPData.ulLeaseTime < dhcpMINIMUM_LEASE_TIME )\r
 433                                 {\r
 434                                         xDHCPData.ulLeaseTime = dhcpMINIMUM_LEASE_TIME;\r
 435                                 }\r
 436                                 else\r
 437                                 {\r
 438                                         /* The lease time is already valid. */\r
 439                                 }\r
 440 \r
 441                                 /* Check for clashes. */\r
 442                                 vARPSendGratuitous();\r
 443                                 vIPReloadDHCPTimer( xDHCPData.ulLeaseTime );\r
 444                         }\r
 445                         else\r
 446                         {\r
 447                                 /* Is it time to send another Discover? */\r
 448                                 if( ( xTaskGetTickCount() - xDHCPData.xDHCPTxTime ) > xDHCPData.xDHCPTxPeriod )\r
 449                                 {\r
 450                                         /* Increase the time period, and if it has not got to the\r
 451                                         point of giving up - send another request. */\r
 452                                         xDHCPData.xDHCPTxPeriod <<= 1;\r
 453 \r
 454                                         if( xDHCPData.xDHCPTxPeriod <= ipconfigMAXIMUM_DISCOVER_TX_PERIOD )\r
 455                                         {\r
 456                                                 xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 457                                                 prvSendDHCPRequest( );\r
 458                                         }\r
 459                                         else\r
 460                                         {\r
 461                                                 /* Give up, start again. */\r
 462                                                 xDHCPData.eDHCPState = eWaitingSendFirstDiscover;\r
 463                                         }\r
 464                                 }\r
 465                         }\r
 466                         break;\r
 467 \r
 468         #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 469                 case eGetLinkLayerAddress:\r
 470                         if( ( xTaskGetTickCount() - xDHCPData.xDHCPTxTime ) > xDHCPData.xDHCPTxPeriod )\r
 471                         {\r
 472                                 if( xARPHadIPClash == pdFALSE )\r
 473                                 {\r
 474                                         /* ARP OK. proceed. */\r
 475                                         iptraceDHCP_SUCCEDEED( xDHCPData.ulOfferedIPAddress );\r
 476 \r
 477                                         /* Auto-IP succeeded, the default configured IP-address will\r
 478                                         be used.  Now call vIPNetworkUpCalls() to send the\r
 479                                         network-up event and start the ARP timer. */\r
 480                                         vIPNetworkUpCalls( );\r
 481                                         xDHCPData.eDHCPState = eNotUsingLeasedAddress;\r
 482                                 }\r
 483                                 else\r
 484                                 {\r
 485                                         /* ARP clashed - try another IP address. */\r
 486                                         prvPrepareLinkLayerIPLookUp();\r
 487 \r
 488                                         /* Setting an IP address manually so set to not using leased\r
 489                                         address mode. */\r
 490                                         xDHCPData.eDHCPState = eGetLinkLayerAddress;\r
 491                                 }\r
 492                         }\r
 493                         break;\r
 494         #endif  /* ipconfigDHCP_FALL_BACK_AUTO_IP */\r
 495 \r
 496                 case eLeasedAddress :\r
 497 \r
 498                         /* Resend the request at the appropriate time to renew the lease. */\r
 499                         prvCreateDHCPSocket();\r
 500 \r
 501                         if( xDHCPData.xDHCPSocket != NULL )\r
 502                         {\r
 503                                 xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 504                                 xDHCPData.xDHCPTxPeriod = dhcpINITIAL_DHCP_TX_PERIOD;\r
 505                                 prvSendDHCPRequest( );\r
 506                                 xDHCPData.eDHCPState = eWaitingAcknowledge;\r
 507 \r
 508                                 /* From now on, we should be called more often */\r
 509                                 vIPReloadDHCPTimer( dhcpINITIAL_TIMER_PERIOD );\r
 510                         }\r
 511                         break;\r
 512 \r
 513                 case eNotUsingLeasedAddress:\r
 514 \r
 515                         vIPSetDHCPTimerEnableState( pdFALSE );\r
 516                         break;\r
 517 \r
 518                 default:\r
 519                         break;\r
 520         }\r
 521 \r
 522         if( xGivingUp != pdFALSE )\r
 523         {\r
 524                 /* xGivingUp became true either because of a time-out, or because\r
 525                 xApplicationDHCPHook() returned another value than 'eDHCPContinue',\r
 526                 meaning that the conversion is canceled from here. */\r
 527 \r
 528                 /* Revert to static IP address. */\r
 529                 taskENTER_CRITICAL();\r
 530                 {\r
 531                         *ipLOCAL_IP_ADDRESS_POINTER = xNetworkAddressing.ulDefaultIPAddress;\r
 532                         iptraceDHCP_REQUESTS_FAILED_USING_DEFAULT_IP_ADDRESS( xNetworkAddressing.ulDefaultIPAddress );\r
 533                 }\r
 534                 taskEXIT_CRITICAL();\r
 535 \r
 536                 xDHCPData.eDHCPState = eNotUsingLeasedAddress;\r
 537                 vIPSetDHCPTimerEnableState( pdFALSE );\r
 538 \r
 539                 /* DHCP failed, the default configured IP-address will be used.  Now\r
 540                 call vIPNetworkUpCalls() to send the network-up event and start the ARP\r
 541                 timer. */\r
 542                 vIPNetworkUpCalls( );\r
 543 \r
 544                 /* Test if socket was indeed created. */\r
 545                 if( xDHCPData.xDHCPSocket != NULL )\r
 546                 {\r
 547                         /* Close socket to ensure packets don't queue on it. */\r
 548                         vSocketClose( xDHCPData.xDHCPSocket );\r
 549                         xDHCPData.xDHCPSocket = NULL;\r
 550                 }\r
 551         }\r
 552 }\r
 553 /*-----------------------------------------------------------*/\r
 554 \r
 555 static void prvCreateDHCPSocket( void )\r
 556 {\r
 557 struct freertos_sockaddr xAddress;\r
 558 BaseType_t xReturn;\r
 559 TickType_t xTimeoutTime = ( TickType_t ) 0;\r
 560 \r
 561         /* Create the socket, if it has not already been created. */\r
 562         if( xDHCPData.xDHCPSocket == NULL )\r
 563         {\r
 564                 xDHCPData.xDHCPSocket = FreeRTOS_socket( FREERTOS_AF_INET, FREERTOS_SOCK_DGRAM, FREERTOS_IPPROTO_UDP );\r
 565                 if( xDHCPData.xDHCPSocket != FREERTOS_INVALID_SOCKET )\r
 566                 {\r
 567 \r
 568                         /* Ensure the Rx and Tx timeouts are zero as the DHCP executes in the\r
 569                         context of the IP task. */\r
 570                         FreeRTOS_setsockopt( xDHCPData.xDHCPSocket, 0, FREERTOS_SO_RCVTIMEO, ( void * ) &xTimeoutTime, sizeof( TickType_t ) );\r
 571                         FreeRTOS_setsockopt( xDHCPData.xDHCPSocket, 0, FREERTOS_SO_SNDTIMEO, ( void * ) &xTimeoutTime, sizeof( TickType_t ) );\r
 572 \r
 573                         /* Bind to the standard DHCP client port. */\r
 574                         xAddress.sin_port = ( uint16_t ) dhcpCLIENT_PORT;\r
 575                         xReturn = vSocketBind( xDHCPData.xDHCPSocket, &xAddress, sizeof( xAddress ), pdFALSE );\r
 576                         if( xReturn != 0 )\r
 577                         {\r
 578                                 /* Binding failed, close the socket again. */\r
 579                                 vSocketClose( xDHCPData.xDHCPSocket );\r
 580                                 xDHCPData.xDHCPSocket = NULL;\r
 581                         }\r
 582                 }\r
 583                 else\r
 584                 {\r
 585                         /* Change to NULL for easier testing. */\r
 586                         xDHCPData.xDHCPSocket = NULL;\r
 587                 }\r
 588         }\r
 589 }\r
 590 /*-----------------------------------------------------------*/\r
 591 \r
 592 static void prvInitialiseDHCP( void )\r
 593 {\r
 594         /* Initialise the parameters that will be set by the DHCP process. Per\r
 595         https://www.ietf.org/rfc/rfc2131.txt, Transaction ID should be a random\r
 596         value chosen by the client. */\r
 597         xDHCPData.ulTransactionId = ipconfigRAND32();\r
 598 \r
 599         /* Check for random number generator API failure. */\r
 600         if( 0 != xDHCPData.ulTransactionId )\r
 601         {\r
 602                 xDHCPData.xUseBroadcast = 0;\r
 603                 xDHCPData.ulOfferedIPAddress = 0UL;\r
 604                 xDHCPData.ulDHCPServerAddress = 0UL;\r
 605                 xDHCPData.xDHCPTxPeriod = dhcpINITIAL_DHCP_TX_PERIOD;\r
 606 \r
 607                 /* Create the DHCP socket if it has not already been created. */\r
 608                 prvCreateDHCPSocket();\r
 609                 FreeRTOS_debug_printf( ( "prvInitialiseDHCP: start after %lu ticks\n", dhcpINITIAL_TIMER_PERIOD ) );\r
 610                 vIPReloadDHCPTimer( dhcpINITIAL_TIMER_PERIOD );\r
 611         }\r
 612 }\r
 613 /*-----------------------------------------------------------*/\r
 614 \r
 615 static BaseType_t prvProcessDHCPReplies( BaseType_t xExpectedMessageType )\r
 616 {\r
 617 uint8_t *pucUDPPayload, *pucLastByte;\r
 618 struct freertos_sockaddr xClient;\r
 619 uint32_t xClientLength = sizeof( xClient );\r
 620 int32_t lBytes;\r
 621 DHCPMessage_t *pxDHCPMessage;\r
 622 uint8_t *pucByte, ucOptionCode, ucLength;\r
 623 uint32_t ulProcessed, ulParameter;\r
 624 BaseType_t xReturn = pdFALSE;\r
 625 const uint32_t ulMandatoryOptions = 2ul; /* DHCP server address, and the correct DHCP message type must be present in the options. */\r
 626 \r
 627         lBytes = FreeRTOS_recvfrom( xDHCPData.xDHCPSocket, ( void * ) &pucUDPPayload, 0ul, FREERTOS_ZERO_COPY, &xClient, &xClientLength );\r
 628 \r
 629         if( lBytes > 0 )\r
 630         {\r
 631                 /* Map a DHCP structure onto the received data. */\r
 632                 pxDHCPMessage = ( DHCPMessage_t * ) ( pucUDPPayload );\r
 633 \r
 634                 /* Sanity check. */\r
 635                 if( ( lBytes >= sizeof( DHCPMessage_t ) ) &&\r
 636                         ( pxDHCPMessage->ulDHCPCookie == ( uint32_t ) dhcpCOOKIE ) &&\r
 637                         ( pxDHCPMessage->ucOpcode == ( uint8_t ) dhcpREPLY_OPCODE ) &&\r
 638                         ( pxDHCPMessage->ulTransactionID == FreeRTOS_htonl( xDHCPData.ulTransactionId ) ) )\r
 639                 {\r
 640                         if( memcmp( ( void * ) &( pxDHCPMessage->ucClientHardwareAddress ),\r
 641                                                 ( void * ) ipLOCAL_MAC_ADDRESS,\r
 642                                                 sizeof( MACAddress_t ) ) == 0 )\r
 643                         {\r
 644                                 /* None of the essential options have been processed yet. */\r
 645                                 ulProcessed = 0ul;\r
 646 \r
 647                                 /* Walk through the options until the dhcpOPTION_END_BYTE byte\r
 648                                 is found, taking care not to walk off the end of the options. */\r
 649                                 pucByte = &( pxDHCPMessage->ucFirstOptionByte );\r
 650                                 pucLastByte = &( pucUDPPayload[ lBytes - dhcpMAX_OPTION_LENGTH_OF_INTEREST ] );\r
 651 \r
 652                                 while( pucByte < pucLastByte )\r
 653                                 {\r
 654                                         ucOptionCode = pucByte[ 0 ];\r
 655                                         if( ucOptionCode == dhcpOPTION_END_BYTE )\r
 656                                         {\r
 657                                                 /* Ready, the last byte has been seen. */\r
 658                                                 break;\r
 659                                         }\r
 660                                         if( ucOptionCode == dhcpZERO_PAD_OPTION_CODE )\r
 661                                         {\r
 662                                                 /* The value zero is used as a pad byte,\r
 663                                                 it is not followed by a length byte. */\r
 664                                                 pucByte += 1;\r
 665                                                 continue;\r
 666                                         }\r
 667 \r
 668                                         /* Stop if the response is malformed. */\r
 669                                         if( pucByte < pucLastByte - 1 )\r
 670                                         {\r
 671                                                 ucLength = pucByte[ 1 ];\r
 672                                                 pucByte += 2;\r
 673 \r
 674                                                 if( pucByte >= pucLastByte - ucLength )\r
 675                                                 {\r
 676                                                         break;\r
 677                                                 }\r
 678                                         }\r
 679                                         else\r
 680                                         {\r
 681                                                 break;\r
 682                                         }\r
 683 \r
 684                                         /* In most cases, a 4-byte network-endian parameter follows,\r
 685                                         just get it once here and use later. */\r
 686                                         if( ucLength >= sizeof( ulParameter ) )\r
 687                                         {\r
 688                                                 memcpy( ( void * ) &( ulParameter ),\r
 689                                                                 ( void * ) pucByte,\r
 690                                                                 ( size_t ) sizeof( ulParameter ) );\r
 691                                         }\r
 692                                         else\r
 693                                         {\r
 694                                                 ulParameter = 0;\r
 695                                         }\r
 696 \r
 697                                         /* Option-specific handling. */\r
 698                                         switch( ucOptionCode )\r
 699                                         {\r
 700                                                 case dhcpMESSAGE_TYPE_OPTION_CODE       :\r
 701 \r
 702                                                         if( *pucByte == ( uint8_t ) xExpectedMessageType )\r
 703                                                         {\r
 704                                                                 /* The message type is the message type the\r
 705                                                                 state machine is expecting. */\r
 706                                                                 ulProcessed++;\r
 707                                                         }\r
 708                                                         else if( *pucByte == ( uint8_t ) dhcpMESSAGE_TYPE_NACK )\r
 709                                                         {\r
 710                                                                 if( xExpectedMessageType == ( BaseType_t ) dhcpMESSAGE_TYPE_ACK )\r
 711                                                                 {\r
 712                                                                         /* Start again. */\r
 713                                                                         xDHCPData.eDHCPState = eWaitingSendFirstDiscover;\r
 714                                                                 }\r
 715                                                         }\r
 716                                                         else\r
 717                                                         {\r
 718                                                                 /* Don't process other message types. */\r
 719                                                         }\r
 720                                                         break;\r
 721 \r
 722                                                 case dhcpSUBNET_MASK_OPTION_CODE :\r
 723 \r
 724                                                         if( ucLength == sizeof( uint32_t ) )\r
 725                                                         {\r
 726                                                                 xNetworkAddressing.ulNetMask = ulParameter;\r
 727                                                         }\r
 728                                                         break;\r
 729 \r
 730                                                 case dhcpGATEWAY_OPTION_CODE :\r
 731 \r
 732                                                         if( ucLength == sizeof( uint32_t ) )\r
 733                                                         {\r
 734                                                                 /* ulProcessed is not incremented in this case\r
 735                                                                 because the gateway is not essential. */\r
 736                                                                 xNetworkAddressing.ulGatewayAddress = ulParameter;\r
 737                                                         }\r
 738                                                         break;\r
 739 \r
 740                                                 case dhcpDNS_SERVER_OPTIONS_CODE :\r
 741 \r
 742                                                         /* ulProcessed is not incremented in this case\r
 743                                                         because the DNS server is not essential.  Only the\r
 744                                                         first DNS server address is taken. */\r
 745                                                         xNetworkAddressing.ulDNSServerAddress = ulParameter;\r
 746                                                         break;\r
 747 \r
 748                                                 case dhcpSERVER_IP_ADDRESS_OPTION_CODE :\r
 749 \r
 750                                                         if( ucLength == sizeof( uint32_t ) )\r
 751                                                         {\r
 752                                                                 if( xExpectedMessageType == ( BaseType_t ) dhcpMESSAGE_TYPE_OFFER )\r
 753                                                                 {\r
 754                                                                         /* Offers state the replying server. */\r
 755                                                                         ulProcessed++;\r
 756                                                                         xDHCPData.ulDHCPServerAddress = ulParameter;\r
 757                                                                 }\r
 758                                                                 else\r
 759                                                                 {\r
 760                                                                         /* The ack must come from the expected server. */\r
 761                                                                         if( xDHCPData.ulDHCPServerAddress == ulParameter )\r
 762                                                                         {\r
 763                                                                                 ulProcessed++;\r
 764                                                                         }\r
 765                                                                 }\r
 766                                                         }\r
 767                                                         break;\r
 768 \r
 769                                                 case dhcpLEASE_TIME_OPTION_CODE :\r
 770 \r
 771                                                         if( ucLength == sizeof( xDHCPData.ulLeaseTime ) )\r
 772                                                         {\r
 773                                                                 /* ulProcessed is not incremented in this case\r
 774                                                                 because the lease time is not essential. */\r
 775                                                                 /* The DHCP parameter is in seconds, convert\r
 776                                                                 to host-endian format. */\r
 777                                                                 xDHCPData.ulLeaseTime = FreeRTOS_ntohl( ulParameter );\r
 778 \r
 779                                                                 /* Divide the lease time by two to ensure a\r
 780                                                                 renew request is sent before the lease actually\r
 781                                                                 expires. */\r
 782                                                                 xDHCPData.ulLeaseTime >>= 1UL;\r
 783 \r
 784                                                                 /* Multiply with configTICK_RATE_HZ to get clock\r
 785                                                                 ticks. */\r
 786                                                                 xDHCPData.ulLeaseTime = configTICK_RATE_HZ * xDHCPData.ulLeaseTime;\r
 787                                                         }\r
 788                                                         break;\r
 789 \r
 790                                                 default :\r
 791 \r
 792                                                         /* Not interested in this field. */\r
 793 \r
 794                                                         break;\r
 795                                         }\r
 796 \r
 797                                         /* Jump over the data to find the next option code. */\r
 798                                         if( ucLength == 0u )\r
 799                                         {\r
 800                                                 break;\r
 801                                         }\r
 802                                         else\r
 803                                         {\r
 804                                                 pucByte += ucLength;\r
 805                                         }\r
 806                                 }\r
 807 \r
 808                                 /* Were all the mandatory options received? */\r
 809                                 if( ulProcessed >= ulMandatoryOptions )\r
 810                                 {\r
 811                                         /* HT:endian: used to be network order */\r
 812                                         xDHCPData.ulOfferedIPAddress = pxDHCPMessage->ulYourIPAddress_yiaddr;\r
 813                                         FreeRTOS_printf( ( "vDHCPProcess: offer %lxip\n", FreeRTOS_ntohl( xDHCPData.ulOfferedIPAddress ) ) );\r
 814                                         xReturn = pdPASS;\r
 815                                 }\r
 816                         }\r
 817                 }\r
 818 \r
 819                 FreeRTOS_ReleaseUDPPayloadBuffer( ( void * ) pucUDPPayload );\r
 820         }\r
 821 \r
 822         return xReturn;\r
 823 }\r
 824 /*-----------------------------------------------------------*/\r
 825 \r
 826 static uint8_t *prvCreatePartDHCPMessage( struct freertos_sockaddr *pxAddress, BaseType_t xOpcode, const uint8_t * const pucOptionsArray, size_t *pxOptionsArraySize )\r
 827 {\r
 828 DHCPMessage_t *pxDHCPMessage;\r
 829 size_t xRequiredBufferSize = sizeof( DHCPMessage_t ) + *pxOptionsArraySize;\r
 830 uint8_t *pucUDPPayloadBuffer;\r
 831 \r
 832 #if( ipconfigDHCP_REGISTER_HOSTNAME == 1 )\r
 833         const char *pucHostName = pcApplicationHostnameHook ();\r
 834         size_t xNameLength = strlen( pucHostName );\r
 835         uint8_t *pucPtr;\r
 836 \r
 837         xRequiredBufferSize += ( 2 + xNameLength );\r
 838 #endif\r
 839 \r
 840         /* Get a buffer.  This uses a maximum delay, but the delay will be capped\r
 841         to ipconfigUDP_MAX_SEND_BLOCK_TIME_TICKS so the return value still needs to\r
 842         be test. */\r
 843         do\r
 844         {\r
 845         } while( ( pucUDPPayloadBuffer = ( uint8_t * ) FreeRTOS_GetUDPPayloadBuffer( xRequiredBufferSize, portMAX_DELAY ) ) == NULL );\r
 846 \r
 847         pxDHCPMessage = ( DHCPMessage_t * ) pucUDPPayloadBuffer;\r
 848 \r
 849         /* Most fields need to be zero. */\r
 850         memset( ( void * ) pxDHCPMessage, 0x00, sizeof( DHCPMessage_t ) );\r
 851 \r
 852         /* Create the message. */\r
 853         pxDHCPMessage->ucOpcode = ( uint8_t ) xOpcode;\r
 854         pxDHCPMessage->ucAddressType = ( uint8_t ) dhcpADDRESS_TYPE_ETHERNET;\r
 855         pxDHCPMessage->ucAddressLength = ( uint8_t ) dhcpETHERNET_ADDRESS_LENGTH;\r
 856         pxDHCPMessage->ulTransactionID = FreeRTOS_htonl( xDHCPData.ulTransactionId );\r
 857         pxDHCPMessage->ulDHCPCookie = ( uint32_t ) dhcpCOOKIE;\r
 858         if( xDHCPData.xUseBroadcast != pdFALSE )\r
 859         {\r
 860                 pxDHCPMessage->usFlags = ( uint16_t ) dhcpBROADCAST;\r
 861         }\r
 862         else\r
 863         {\r
 864                 pxDHCPMessage->usFlags = 0u;\r
 865         }\r
 866 \r
 867         memcpy( ( void * ) &( pxDHCPMessage->ucClientHardwareAddress[ 0 ] ), ( void * ) ipLOCAL_MAC_ADDRESS, sizeof( MACAddress_t ) );\r
 868 \r
 869         /* Copy in the const part of the options options. */\r
 870         memcpy( ( void * ) &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET ] ), ( void * ) pucOptionsArray, *pxOptionsArraySize );\r
 871 \r
 872         #if( ipconfigDHCP_REGISTER_HOSTNAME == 1 )\r
 873         {\r
 874                 /* With this option, the hostname can be registered as well which makes\r
 875                 it easier to lookup a device in a router's list of DHCP clients. */\r
 876 \r
 877                 /* Point to where the OPTION_END was stored to add data. */\r
 878                 pucPtr = &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET + ( *pxOptionsArraySize - 1 ) ] );\r
 879                 pucPtr[ 0 ] = dhcpDNS_HOSTNAME_OPTIONS_CODE;\r
 880                 pucPtr[ 1 ] = ( uint8_t ) xNameLength;\r
 881                 memcpy( ( void *) ( pucPtr + 2 ), pucHostName, xNameLength );\r
 882                 pucPtr[ 2 + xNameLength ] = dhcpOPTION_END_BYTE;\r
 883                 *pxOptionsArraySize += ( 2 + xNameLength );\r
 884         }\r
 885         #endif\r
 886 \r
 887         /* Map in the client identifier. */\r
 888         memcpy( ( void * ) &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET + dhcpCLIENT_IDENTIFIER_OFFSET ] ),\r
 889                 ( void * ) ipLOCAL_MAC_ADDRESS, sizeof( MACAddress_t ) );\r
 890 \r
 891         /* Set the addressing. */\r
 892         pxAddress->sin_addr = ipBROADCAST_IP_ADDRESS;\r
 893         pxAddress->sin_port = ( uint16_t ) dhcpSERVER_PORT;\r
 894 \r
 895         return pucUDPPayloadBuffer;\r
 896 }\r
 897 /*-----------------------------------------------------------*/\r
 898 \r
 899 static void prvSendDHCPRequest( void )\r
 900 {\r
 901 uint8_t *pucUDPPayloadBuffer;\r
 902 struct freertos_sockaddr xAddress;\r
 903 static const uint8_t ucDHCPRequestOptions[] =\r
 904 {\r
 905         /* Do not change the ordering without also changing\r
 906         dhcpCLIENT_IDENTIFIER_OFFSET, dhcpREQUESTED_IP_ADDRESS_OFFSET and\r
 907         dhcpDHCP_SERVER_IP_ADDRESS_OFFSET. */\r
 908         dhcpMESSAGE_TYPE_OPTION_CODE, 1, dhcpMESSAGE_TYPE_REQUEST,              /* Message type option. */\r
 909         dhcpCLIENT_IDENTIFIER_OPTION_CODE, 6, 0, 0, 0, 0, 0, 0,                 /* Client identifier. */\r
 910         dhcpREQUEST_IP_ADDRESS_OPTION_CODE, 4, 0, 0, 0, 0,                              /* The IP address being requested. */\r
 911         dhcpSERVER_IP_ADDRESS_OPTION_CODE, 4, 0, 0, 0, 0,                               /* The IP address of the DHCP server. */\r
 912         dhcpOPTION_END_BYTE\r
 913 };\r
 914 size_t xOptionsLength = sizeof( ucDHCPRequestOptions );\r
 915 \r
 916         pucUDPPayloadBuffer = prvCreatePartDHCPMessage( &xAddress, dhcpREQUEST_OPCODE, ucDHCPRequestOptions, &xOptionsLength );\r
 917 \r
 918         /* Copy in the IP address being requested. */\r
 919         memcpy( ( void * ) &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET + dhcpREQUESTED_IP_ADDRESS_OFFSET ] ),\r
 920                 ( void * ) &( xDHCPData.ulOfferedIPAddress ), sizeof( xDHCPData.ulOfferedIPAddress ) );\r
 921 \r
 922         /* Copy in the address of the DHCP server being used. */\r
 923         memcpy( ( void * ) &( pucUDPPayloadBuffer[ dhcpFIRST_OPTION_BYTE_OFFSET + dhcpDHCP_SERVER_IP_ADDRESS_OFFSET ] ),\r
 924                 ( void * ) &( xDHCPData.ulDHCPServerAddress ), sizeof( xDHCPData.ulDHCPServerAddress ) );\r
 925 \r
 926         FreeRTOS_debug_printf( ( "vDHCPProcess: reply %lxip\n", FreeRTOS_ntohl( xDHCPData.ulOfferedIPAddress ) ) );\r
 927         iptraceSENDING_DHCP_REQUEST();\r
 928 \r
 929         if( FreeRTOS_sendto( xDHCPData.xDHCPSocket, pucUDPPayloadBuffer, ( sizeof( DHCPMessage_t ) + xOptionsLength ), FREERTOS_ZERO_COPY, &xAddress, sizeof( xAddress ) ) == 0 )\r
 930         {\r
 931                 /* The packet was not successfully queued for sending and must be\r
 932                 returned to the stack. */\r
 933                 FreeRTOS_ReleaseUDPPayloadBuffer( pucUDPPayloadBuffer );\r
 934         }\r
 935 }\r
 936 /*-----------------------------------------------------------*/\r
 937 \r
 938 static void prvSendDHCPDiscover( void )\r
 939 {\r
 940 uint8_t *pucUDPPayloadBuffer;\r
 941 struct freertos_sockaddr xAddress;\r
 942 static const uint8_t ucDHCPDiscoverOptions[] =\r
 943 {\r
 944         /* Do not change the ordering without also changing dhcpCLIENT_IDENTIFIER_OFFSET. */\r
 945         dhcpMESSAGE_TYPE_OPTION_CODE, 1, dhcpMESSAGE_TYPE_DISCOVER,                                     /* Message type option. */\r
 946         dhcpCLIENT_IDENTIFIER_OPTION_CODE, 6, 0, 0, 0, 0, 0, 0,                                         /* Client identifier. */\r
 947         dhcpPARAMETER_REQUEST_OPTION_CODE, 3, dhcpSUBNET_MASK_OPTION_CODE, dhcpGATEWAY_OPTION_CODE, dhcpDNS_SERVER_OPTIONS_CODE,        /* Parameter request option. */\r
 948         dhcpOPTION_END_BYTE\r
 949 };\r
 950 size_t xOptionsLength = sizeof( ucDHCPDiscoverOptions );\r
 951 \r
 952         pucUDPPayloadBuffer = prvCreatePartDHCPMessage( &xAddress, dhcpREQUEST_OPCODE, ucDHCPDiscoverOptions, &xOptionsLength );\r
 953 \r
 954         FreeRTOS_debug_printf( ( "vDHCPProcess: discover\n" ) );\r
 955         iptraceSENDING_DHCP_DISCOVER();\r
 956 \r
 957         if( FreeRTOS_sendto( xDHCPData.xDHCPSocket, pucUDPPayloadBuffer, ( sizeof( DHCPMessage_t ) + xOptionsLength ), FREERTOS_ZERO_COPY, &xAddress, sizeof( xAddress ) ) == 0 )\r
 958         {\r
 959                 /* The packet was not successfully queued for sending and must be\r
 960                 returned to the stack. */\r
 961                 FreeRTOS_ReleaseUDPPayloadBuffer( pucUDPPayloadBuffer );\r
 962         }\r
 963 }\r
 964 /*-----------------------------------------------------------*/\r
 965 \r
 966 #if( ipconfigDHCP_FALL_BACK_AUTO_IP != 0 )\r
 967 \r
 968         static void prvPrepareLinkLayerIPLookUp( void )\r
 969         {\r
 970         uint8_t ucLinkLayerIPAddress[ 2 ];\r
 971 \r
 972                 /* After DHCP has failed to answer, prepare everything to start\r
 973                 trying-out LinkLayer IP-addresses, using the random method. */\r
 974                 xDHCPData.xDHCPTxTime = xTaskGetTickCount();\r
 975 \r
 976                 ucLinkLayerIPAddress[ 0 ] = ( uint8_t )1 + ( uint8_t )( ipconfigRAND32() % 0xFDu );             /* get value 1..254 for IP-address 3rd byte of IP address to try. */\r
 977                 ucLinkLayerIPAddress[ 1 ] = ( uint8_t )1 + ( uint8_t )( ipconfigRAND32() % 0xFDu );             /* get value 1..254 for IP-address 4th byte of IP address to try. */\r
 978 \r
 979                 xNetworkAddressing.ulGatewayAddress = FreeRTOS_htonl( 0xA9FE0203 );\r
 980 \r
 981                 /* prepare xDHCPData with data to test. */\r
 982                 xDHCPData.ulOfferedIPAddress =\r
 983                         FreeRTOS_inet_addr_quick( LINK_LAYER_ADDRESS_0, LINK_LAYER_ADDRESS_1, ucLinkLayerIPAddress[ 0 ], ucLinkLayerIPAddress[ 1 ] );\r
 984 \r
 985                 xDHCPData.ulLeaseTime = dhcpDEFAULT_LEASE_TIME;  /*  don't care about lease time. just put anything. */\r
 986 \r
 987                 xNetworkAddressing.ulNetMask =\r
 988                         FreeRTOS_inet_addr_quick( LINK_LAYER_NETMASK_0, LINK_LAYER_NETMASK_1, LINK_LAYER_NETMASK_2, LINK_LAYER_NETMASK_3 );\r
 989 \r
 990                 /* DHCP completed.  The IP address can now be used, and the\r
 991                 timer set to the lease timeout time. */\r
 992                 *ipLOCAL_IP_ADDRESS_POINTER = xDHCPData.ulOfferedIPAddress;\r
 993 \r
 994                 /* Setting the 'local' broadcast address, something like 192.168.1.255' */\r
 995                 xNetworkAddressing.ulBroadcastAddress = ( xDHCPData.ulOfferedIPAddress & xNetworkAddressing.ulNetMask ) |  ~xNetworkAddressing.ulNetMask;\r
 996 \r
 997                 /* Close socket to ensure packets don't queue on it. not needed anymore as DHCP failed. but still need timer for ARP testing. */\r
 998                 vSocketClose( xDHCPData.xDHCPSocket );\r
 999                 xDHCPData.xDHCPSocket = NULL;\r
1000                 xDHCPData.xDHCPTxPeriod = pdMS_TO_TICKS( 3000ul + ( ipconfigRAND32() & 0x3fful ) ); /*  do ARP test every (3 + 0-1024mS) seconds. */\r
1001 \r
1002                 xARPHadIPClash = pdFALSE;          /* reset flag that shows if have ARP clash. */\r
1003                 vARPSendGratuitous();\r
1004         }\r
1005 \r
1006 #endif /* ipconfigDHCP_FALL_BACK_AUTO_IP */\r
1007 /*-----------------------------------------------------------*/\r
1008 \r
1009 #endif /* ipconfigUSE_DHCP != 0 */\r
1010 \r
1011 \r