--- /dev/null
+/*\r
+ LUFA Library\r
+ Copyright (C) Dean Camera, 2009.\r
+ \r
+ dean [at] fourwalledcubicle [dot] com\r
+ www.fourwalledcubicle.com\r
+*/\r
+\r
+/*\r
+ Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com)\r
+\r
+ Permission to use, copy, modify, and distribute this software\r
+ and its documentation for any purpose and without fee is hereby\r
+ granted, provided that the above copyright notice appear in all\r
+ copies and that both that the copyright notice and this\r
+ permission notice and warranty disclaimer appear in supporting\r
+ documentation, and that the name of the author not be used in\r
+ advertising or publicity pertaining to distribution of the\r
+ software without specific, written prior permission.\r
+\r
+ The author disclaim all warranties with regard to this\r
+ software, including all implied warranties of merchantability\r
+ and fitness. In no event shall the author be liable for any\r
+ special, indirect or consequential damages or any damages\r
+ whatsoever resulting from loss of use, data or profits, whether\r
+ in an action of contract, negligence or other tortious action,\r
+ arising out of or in connection with the use or performance of\r
+ this software.\r
+*/\r
+\r
+/** \file\r
+ *\r
+ * Dynamic Host Configuration Protocol (DHCP) packet handling routines. This protocol\r
+ * handles the automatic IP negotiation to the host, so that the host will use the provided\r
+ * IP address given to it by the device.\r
+ */\r
+ \r
+#include "DHCP.h"\r
+\r
+/** Processes a DHCP packet inside an Ethernet frame, and writes the appropriate response\r
+ * to the output Ethernet frame if the host is requesting or accepting an IP address.\r
+ *\r
+ * \param IPHeaderInStart Pointer to the start of the incomming packet's IP header\r
+ * \param DHCPHeaderInStart Pointer to the start of the incomming packet's DHCP header\r
+ * \param DHCPHeaderOutStart Pointer to the start of the outgoing packet's DHCP header\r
+ *\r
+ * \return The number of bytes written to the out Ethernet frame if any, NO_RESPONSE otherwise\r
+ */\r
+int16_t DHCP_ProcessDHCPPacket(void* IPHeaderInStart, void* DHCPHeaderInStart, void* DHCPHeaderOutStart)\r
+{\r
+ IP_Header_t* IPHeaderIN = (IP_Header_t*)IPHeaderInStart;\r
+ DHCP_Header_t* DHCPHeaderIN = (DHCP_Header_t*)DHCPHeaderInStart;\r
+ DHCP_Header_t* DHCPHeaderOUT = (DHCP_Header_t*)DHCPHeaderOutStart;\r
+ \r
+ uint8_t* DHCPOptionsINStart = (uint8_t*)(DHCPHeaderInStart + sizeof(DHCP_Header_t));\r
+ uint8_t* DHCPOptionsOUTStart = (uint8_t*)(DHCPHeaderOutStart + sizeof(DHCP_Header_t));\r
+\r
+ DecodeDHCPHeader(DHCPHeaderInStart);\r
+\r
+ /* Zero out the response DHCP packet, as much of it legacy and left at 0 */\r
+ memset(DHCPHeaderOUT, 0, sizeof(DHCP_Header_t));\r
+\r
+ /* Fill out the response DHCP packet */\r
+ DHCPHeaderOUT->HardwareType = DHCPHeaderIN->HardwareType;\r
+ DHCPHeaderOUT->Operation = DHCP_OP_BOOTREPLY;\r
+ DHCPHeaderOUT->HardwareAddressLength = DHCPHeaderIN->HardwareAddressLength;\r
+ DHCPHeaderOUT->Hops = 0;\r
+ DHCPHeaderOUT->TransactionID = DHCPHeaderIN->TransactionID;\r
+ DHCPHeaderOUT->ElapsedSeconds = 0;\r
+ DHCPHeaderOUT->Flags = DHCPHeaderIN->Flags;\r
+ DHCPHeaderOUT->YourIP = ClientIPAddress;\r
+ memcpy(&DHCPHeaderOUT->ClientHardwareAddress, &DHCPHeaderIN->ClientHardwareAddress, sizeof(MAC_Address_t));\r
+ DHCPHeaderOUT->Cookie = SwapEndian_32(DHCP_MAGIC_COOKIE);\r
+ \r
+ /* Alter the incomming IP packet header so that the corrected IP source and destinations are used - this means that\r
+ when the response IP header is generated, it will use the corrected addresses and not the null/broatcast addresses */\r
+ IPHeaderIN->SourceAddress = ClientIPAddress;\r
+ IPHeaderIN->DestinationAddress = ServerIPAddress;\r
+\r
+ /* Process the incomming DHCP packet options */\r
+ while (DHCPOptionsINStart[0] != DHCP_OPTION_END)\r
+ { \r
+ /* Find the Message Type DHCP option, to determine the type of DHCP packet */\r
+ if (DHCPOptionsINStart[0] == DHCP_OPTION_MESSAGETYPE)\r
+ {\r
+ if ((DHCPOptionsINStart[2] == DHCP_MESSAGETYPE_DISCOVER) || (DHCPOptionsINStart[2] == DHCP_MESSAGETYPE_REQUEST))\r
+ {\r
+ /* Fill out the response DHCP packet options for a DHCP OFFER or ACK response */\r
+\r
+ *(DHCPOptionsOUTStart++) = DHCP_OPTION_MESSAGETYPE;\r
+ *(DHCPOptionsOUTStart++) = 1;\r
+ *(DHCPOptionsOUTStart++) = (DHCPOptionsINStart[2] == DHCP_MESSAGETYPE_DISCOVER) ? DHCP_MESSAGETYPE_OFFER\r
+ : DHCP_MESSAGETYPE_ACK;\r
+\r
+ *(DHCPOptionsOUTStart++) = DHCP_OPTION_SUBNETMASK;\r
+ *(DHCPOptionsOUTStart++) = 4;\r
+ *(DHCPOptionsOUTStart++) = 0xFF;\r
+ *(DHCPOptionsOUTStart++) = 0xFF;\r
+ *(DHCPOptionsOUTStart++) = 0xFF;\r
+ *(DHCPOptionsOUTStart++) = 0x00;\r
+\r
+ *(DHCPOptionsOUTStart++) = DHCP_OPTION_DHCPSERVER;\r
+ *(DHCPOptionsOUTStart++) = sizeof(IP_Address_t);\r
+ memcpy(DHCPOptionsOUTStart, &ServerIPAddress, sizeof(IP_Address_t));\r
+ DHCPOptionsOUTStart += sizeof(IP_Address_t);\r
+\r
+ *(DHCPOptionsOUTStart++) = DHCP_OPTION_END;\r
+ \r
+ return (sizeof(DHCP_Header_t) + 12 + sizeof(IP_Address_t));\r
+ }\r
+ }\r
+ \r
+ /* Go to the next DHCP option - skip one byte if option is a padding byte, else skip the complete option's size */\r
+ DHCPOptionsINStart += ((DHCPOptionsINStart[0] == DHCP_OPTION_PAD) ? 1 : (DHCPOptionsINStart[1] + 2));\r
+ }\r
+ \r
+ return NO_RESPONSE;\r
+}\r
projects / pub / lufa.git / blobdiff