Add RNDIS Device support to the Webserver project, so that the files stored on the...
[pub/lufa.git] / Projects / Webserver / Lib / DHCPServerApp.c
diff --git a/Projects/Webserver/Lib/DHCPServerApp.c b/Projects/Webserver/Lib/DHCPServerApp.c
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+/*\r
+             LUFA Library\r
+     Copyright (C) Dean Camera, 2011.\r
+\r
+  dean [at] fourwalledcubicle [dot] com\r
+           www.lufa-lib.org\r
+*/\r
+\r
+/*\r
+  Copyright 2011  Dean Camera (dean [at] fourwalledcubicle [dot] com)\r
+\r
+  Permission to use, copy, modify, distribute, and sell this\r
+  software and its documentation for any purpose is hereby granted\r
+  without fee, provided that the above copyright notice appear in\r
+  all 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
+#if defined(ENABLE_DHCP_SERVER) || defined(__DOXYGEN__)\r
+\r
+/** \file\r
+ *\r
+ *  DHCP Server Application. When connected to the uIP stack, this will send IP configuration settings to a\r
+ *  DHCP client on the network.\r
+ */\r
+\r
+#define  INCLUDE_FROM_DHCPSERVERAPP_C\r
+#include "DHCPServerApp.h"\r
+\r
+struct uip_conn* BroadcastConnection;\r
+\r
+uint8_t LeasedIPs[255 / 8];\r
+       \r
+/** Initialization function for the DHCP server. */\r
+void DHCPServerApp_Init(void)\r
+{\r
+       /* Listen on port 67 for DHCP server connections from hosts */\r
+       uip_listen(HTONS(DHCP_SERVER_PORT));\r
+       \r
+       /* Create a new UDP connection to the DHCP server port for the DHCP solicitation */\r
+       struct uip_udp_conn* BroadcastConnection = uip_udp_new(&uip_broadcast_addr, HTONS(DHCP_CLIENT_PORT));\r
+\r
+       /* If the connection was successfully created, bind it to the local DHCP client port */\r
+       if (BroadcastConnection != NULL)\r
+         uip_udp_bind(BroadcastConnection, HTONS(DHCP_SERVER_PORT));\r
+         \r
+       /* Set all IP addresses as unleased */\r
+       memset(LeasedIPs, 0x00, sizeof(LeasedIPs));\r
+}\r
+\r
+/** uIP stack application callback for the DHCP server. This function must be called each time the TCP/IP stack\r
+ *  needs a UDP packet to be processed.\r
+ */\r
+void DHCPServerApp_Callback(void)\r
+{\r
+       DHCP_Header_t* const AppData     = (DHCP_Header_t*)uip_appdata;\r
+       uint16_t             AppDataSize = 0;\r
+\r
+       uint8_t DHCPMessageType;\r
+       if (!(DHCPCommon_GetOption(AppData->Options, DHCP_OPTION_MSG_TYPE, &DHCPMessageType)))\r
+               return;\r
+\r
+       uip_ipaddr_t Netmask, GatewayIPAddress;\r
+       struct uip_eth_addr RemoteMACAddress;\r
+       uint32_t            TransactionID;\r
+\r
+       memcpy(&RemoteMACAddress, &AppData->ClientHardwareAddress, sizeof(struct uip_eth_addr));\r
+       uip_getnetmask(&Netmask);\r
+       uip_getdraddr(&GatewayIPAddress);       \r
+       TransactionID = AppData->TransactionID;\r
+\r
+       switch (DHCPMessageType)\r
+       {\r
+               case DHCP_DISCOVER:\r
+                       AppDataSize += DHCPServerApp_FillDHCPHeader(AppData, DHCP_OFFER, &RemoteMACAddress, TransactionID);\r
+\r
+                       AppDataSize += DHCPCommon_SetOption(AppData->Options, DHCP_OPTION_SUBNET_MASK,\r
+                                                           sizeof(uip_ipaddr_t), &Netmask);\r
+                       AppDataSize += DHCPCommon_SetOption(AppData->Options, DHCP_OPTION_ROUTER,\r
+                                                           sizeof(uip_ipaddr_t), &GatewayIPAddress);\r
+                       \r
+                       /* Send the DHCP OFFER packet */\r
+                       uip_poll_conn(BroadcastConnection);\r
+                       memcpy(&uip_udp_conn->ripaddr, &uip_broadcast_addr, sizeof(uip_ipaddr_t));\r
+                       uip_udp_send(AppDataSize);\r
+\r
+                       break;\r
+               case DHCP_REQUEST:\r
+                       if (!(DHCPServerApp_CheckIfIPLeased(&AppData->YourIP)))\r
+                       {\r
+                               AppDataSize += DHCPServerApp_FillDHCPHeader(AppData, DHCP_ACK, &RemoteMACAddress, TransactionID);\r
+\r
+                               AppDataSize += DHCPCommon_SetOption(AppData->Options, DHCP_OPTION_SUBNET_MASK,\r
+                                                                                                       sizeof(uip_ipaddr_t), &Netmask);\r
+                               AppDataSize += DHCPCommon_SetOption(AppData->Options, DHCP_OPTION_ROUTER,\r
+                                                                                                       sizeof(uip_ipaddr_t), &GatewayIPAddress);\r
+\r
+                               DHCPServerApp_LeaseIP(&AppData->YourIP);\r
+                       }\r
+                       else\r
+                       {\r
+                               AppDataSize += DHCPServerApp_FillDHCPHeader(AppData, DHCP_NAK, &RemoteMACAddress, TransactionID);                       \r
+                       }\r
+                       \r
+                       /* Send the DHCP ACK or NAK packet */\r
+                       uip_poll_conn(BroadcastConnection);\r
+                       memcpy(&uip_udp_conn->ripaddr, &uip_broadcast_addr, sizeof(uip_ipaddr_t));\r
+                       uip_udp_send(AppDataSize);\r
+               \r
+                       break;\r
+               case DHCP_RELEASE:\r
+                       /* Mark the IP address as released in the allocation table */\r
+                       DHCPServerApp_UnleaseIP(&uip_udp_conn->ripaddr);\r
+                       break;\r
+       }\r
+}\r
+\r
+/** Fills the DHCP packet response with the appropriate BOOTP header for DHCP. This fills out all the required\r
+ *  fields, leaving only the additional DHCP options to be added to the packet before it is sent to the DHCP client.\r
+ *\r
+ *  \param[out] DHCPHeader             Location in the packet buffer where the BOOTP header should be written to\r
+ *  \param[in]  DHCPMessageType        DHCP Message type, such as DHCP_DISCOVER\r
+ *  \param[in]  ClientHardwareAddress  Client MAC address the created transaction should be directed to\r
+ *  \param[in]  TransactionID          Transaction ID the created transaction should be associated with\r
+ *\r
+ *  \return Size in bytes of the created DHCP packet\r
+ */\r
+static uint16_t DHCPServerApp_FillDHCPHeader(DHCP_Header_t* const DHCPHeader,\r
+                                             const uint8_t DHCPMessageType,\r
+                                             struct uip_eth_addr* ClientHardwareAddress,\r
+                                             uint32_t TransactionID)\r
+{\r
+       /* Erase existing packet data so that we start will all 0x00 DHCP header data */\r
+       memset(DHCPHeader, 0, sizeof(DHCP_Header_t));\r
+\r
+       DHCPHeader->Operation             = DHCPMessageType;\r
+       DHCPHeader->HardwareType          = DHCP_HTYPE_ETHERNET;\r
+       DHCPHeader->HardwareAddressLength = sizeof(MACAddress);\r
+       DHCPHeader->Hops                  = 0;\r
+       DHCPHeader->TransactionID         = TransactionID;\r
+       DHCPHeader->ElapsedSeconds        = 0;\r
+       DHCPHeader->Flags                 = 0;\r
+       memcpy(&DHCPHeader->NextServerIP, &uip_hostaddr, sizeof(uip_ipaddr_t));\r
+       if (uip_ipaddr_cmp(&DHCPHeader->YourIP, &uip_all_zeroes_addr))\r
+         DHCPServerApp_GetUnleasedIP(&DHCPHeader->YourIP);\r
+       memcpy(&DHCPHeader->ClientHardwareAddress, ClientHardwareAddress, sizeof(struct uip_eth_addr));\r
+       DHCPHeader->Cookie                = DHCP_MAGIC_COOKIE;\r
+         \r
+       /* Add a DHCP message type and terminator options to the start of the DHCP options field */\r
+       DHCPHeader->Options[0]            = DHCP_OPTION_MSG_TYPE;\r
+       DHCPHeader->Options[1]            = 1;\r
+       DHCPHeader->Options[2]            = DHCPMessageType;\r
+       DHCPHeader->Options[3]            = DHCP_OPTION_END;\r
+\r
+       /* Calculate the total number of bytes added to the outgoing packet */\r
+       return (sizeof(DHCP_Header_t) + 4);\r
+}\r
+\r
+/** Checks to see if the nominated IP address has already been allocated to a client.\r
+ *\r
+ *  \param[in] IPAddress  IP Address whose lease status should be checked\r
+ *\r
+ *  \pre The IP address must be within the same /24 subnet as the virtual webserver.\r
+ *\r
+ *  \return Boolean true if the IP has already been leased to a client, false otherwise.\r
+ */\r
+static bool DHCPServerApp_CheckIfIPLeased(uip_ipaddr_t* IPAddress)\r
+{\r
+       uint8_t Byte = (IPAddress->u8[3] / 8);\r
+       uint8_t Mask = (1 << (IPAddress->u8[3] % 8));\r
+       \r
+       if (!(IPAddress->u8[3] == uip_hostaddr.u8[3]) && !(LeasedIPs[Byte] & Mask))\r
+         return false;\r
+       else\r
+         return true;\r
+}\r
+\r
+/** Retrieves the next unleased IP in the IP address pool.\r
+ *\r
+ *  \param[out] NewIPAddress  Location where the generated IP Address should be stored\r
+ */\r
+static void DHCPServerApp_GetUnleasedIP(uip_ipaddr_t* NewIPAddress)\r
+{\r
+       uip_ipaddr_copy(NewIPAddress, &uip_hostaddr);\r
+       \r
+       for (uint8_t IP = 1; IP < 254; IP++)\r
+       {\r
+               NewIPAddress->u8[3] = IP;\r
+               \r
+               if (!(DHCPServerApp_CheckIfIPLeased(NewIPAddress)))\r
+                 return;\r
+       }\r
+}\r
+\r
+/** Marks the given IP Address as leased in the address pool, so that it will not be\r
+ *  allocated to another client unless it is first released.\r
+ *\r
+ *  \param[in] IPAddress  IP Address to mark as leased\r
+ *\r
+ *  \pre The IP address must be within the same /24 subnet as the virtual webserver.\r
+ */\r
+static void DHCPServerApp_LeaseIP(uip_ipaddr_t* IPAddress)\r
+{\r
+       uint8_t Byte = (IPAddress->u8[3] / 8);\r
+       uint8_t Mask = (1 << (IPAddress->u8[3] % 8));\r
+       \r
+       LeasedIPs[Byte] |= Mask;\r
+}\r
+\r
+/** Marks the given IP Address as not leased in the address pool, so that it can be\r
+ *  allocated to another client upon request.\r
+ *\r
+ *  \param[in] IPAddress  IP Address to mark as not leased\r
+ *\r
+ *  \pre The IP address must be within the same /24 subnet as the virtual webserver.\r
+ */\r
+static void DHCPServerApp_UnleaseIP(uip_ipaddr_t* IPAddress)\r
+{\r
+       uint8_t Byte = (IPAddress->u8[3] / 8);\r
+       uint8_t Mask = (1 << (IPAddress->u8[3] % 8));\r
+       \r
+       LeasedIPs[Byte] &= ~Mask;\r
+}\r
+#endif\r
+\r