Blame view

src/lufa-LUFA-170418/Projects/Webserver/Lib/DHCPClientApp.c 8.64 KB
ca85a266   gperson   le vrai commit, c...
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
  /*
               LUFA Library
       Copyright (C) Dean Camera, 2017.
  
    dean [at] fourwalledcubicle [dot] com
             www.lufa-lib.org
  */
  
  /*
    Copyright 2017  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  
    Permission to use, copy, modify, distribute, and sell this
    software and its documentation for any purpose is hereby granted
    without fee, provided that the above copyright notice appear in
    all copies and that both that the copyright notice and this
    permission notice and warranty disclaimer appear in supporting
    documentation, and that the name of the author not be used in
    advertising or publicity pertaining to distribution of the
    software without specific, written prior permission.
  
    The author disclaims all warranties with regard to this
    software, including all implied warranties of merchantability
    and fitness.  In no event shall the author be liable for any
    special, indirect or consequential damages or any damages
    whatsoever resulting from loss of use, data or profits, whether
    in an action of contract, negligence or other tortious action,
    arising out of or in connection with the use or performance of
    this software.
  */
  
  /** \file
   *
   *  DHCP Client Application. When connected to the uIP stack, this will retrieve IP configuration settings from the
   *  DHCP server on the network.
   */
  
  #define  INCLUDE_FROM_DHCPCLIENTAPP_C
  #include "DHCPClientApp.h"
  
  #if defined(ENABLE_DHCP_CLIENT) || defined(__DOXYGEN__)
  
  /** Initialization function for the DHCP client. */
  void DHCPClientApp_Init(void)
  {
  	/* Create a new UDP connection to the DHCP server port for the DHCP solicitation */
  	struct uip_udp_conn* Connection = uip_udp_new(&uip_broadcast_addr, HTONS(DHCP_SERVER_PORT));
  
  	/* If the connection was successfully created, bind it to the local DHCP client port */
  	if (Connection != NULL)
  	{
  		uip_udp_appstate_t* const AppState = &Connection->appstate;
  		uip_udp_bind(Connection, HTONS(DHCP_CLIENT_PORT));
  
  		/* Set the initial client state */
  		AppState->DHCPClient.CurrentState = DHCP_STATE_SendDiscover;
  
  		/* Set timeout period to half a second for a DHCP server to respond */
  		timer_set(&AppState->DHCPClient.Timeout, CLOCK_SECOND / 2);
  	}
  }
  
  /** uIP stack application callback for the DHCP client. This function must be called each time the TCP/IP stack
   *  needs a UDP packet to be processed.
   */
  void DHCPClientApp_Callback(void)
  {
  	uip_udp_appstate_t* const AppState    = &uip_udp_conn->appstate;
  	DHCP_Header_t*      const AppData     = (DHCP_Header_t*)uip_appdata;
  	uint16_t                  AppDataSize = 0;
  
  	switch (AppState->DHCPClient.CurrentState)
  	{
  		case DHCP_STATE_SendDiscover:
  			/* Clear all DHCP settings, reset client IP address */
  			memset(&AppState->DHCPClient.DHCPOffer_Data, 0x00, sizeof(AppState->DHCPClient.DHCPOffer_Data));
  			uip_sethostaddr((uip_ipaddr_t*)&AppState->DHCPClient.DHCPOffer_Data.AllocatedIP);
  
  			/* Fill out the DHCP response header */
  			AppDataSize += DHCPClientApp_FillDHCPHeader(AppData, DHCP_DISCOVER, AppState);
  
  			/* Add the required DHCP options list to the packet */
  			uint8_t RequiredOptionList[] = {DHCP_OPTION_SUBNET_MASK, DHCP_OPTION_ROUTER, DHCP_OPTION_DNS_SERVER};
  			AppDataSize += DHCPCommon_SetOption(AppData->Options, DHCP_OPTION_REQ_LIST, sizeof(RequiredOptionList),
  			                                    RequiredOptionList);
  
  			/* Send the DHCP DISCOVER packet */
  			uip_udp_send(AppDataSize);
  
  			/* Reset the timeout timer, progress to next state */
  			timer_reset(&AppState->DHCPClient.Timeout);
  			AppState->DHCPClient.CurrentState = DHCP_STATE_WaitForOffer;
  
  			break;
  		case DHCP_STATE_WaitForOffer:
  			if (!(uip_newdata()))
  			{
  				/* Check if the DHCP timeout period has expired while waiting for a response */
  				if (timer_expired(&AppState->DHCPClient.Timeout))
  				  AppState->DHCPClient.CurrentState = DHCP_STATE_SendDiscover;
  
  				break;
  			}
  
  			uint8_t OfferResponse_MessageType;
  			if ((AppData->TransactionID == DHCP_TRANSACTION_ID) &&
  			    DHCPCommon_GetOption(AppData->Options, DHCP_OPTION_MSG_TYPE, &OfferResponse_MessageType) &&
  			    (OfferResponse_MessageType == DHCP_OFFER))
  			{
  				/* Received a DHCP offer for an IP address, copy over values for later request */
  				memcpy(&AppState->DHCPClient.DHCPOffer_Data.AllocatedIP, &AppData->YourIP, sizeof(uip_ipaddr_t));
  				DHCPCommon_GetOption(AppData->Options, DHCP_OPTION_SUBNET_MASK, &AppState->DHCPClient.DHCPOffer_Data.Netmask);
  				DHCPCommon_GetOption(AppData->Options, DHCP_OPTION_ROUTER,      &AppState->DHCPClient.DHCPOffer_Data.GatewayIP);
  				DHCPCommon_GetOption(AppData->Options, DHCP_OPTION_SERVER_ID,   &AppState->DHCPClient.DHCPOffer_Data.ServerIP);
  
  				timer_reset(&AppState->DHCPClient.Timeout);
  				AppState->DHCPClient.CurrentState = DHCP_STATE_SendRequest;
  			}
  
  			break;
  		case DHCP_STATE_SendRequest:
  			/* Fill out the DHCP response header */
  			AppDataSize += DHCPClientApp_FillDHCPHeader(AppData, DHCP_REQUEST, AppState);
  
  			/* Add the DHCP REQUESTED IP ADDRESS option to the packet */
  			AppDataSize += DHCPCommon_SetOption(AppData->Options, DHCP_OPTION_REQ_IPADDR, sizeof(uip_ipaddr_t),
  			                                    &AppState->DHCPClient.DHCPOffer_Data.AllocatedIP);
  
  			/* Add the DHCP SERVER IP ADDRESS option to the packet */
  			AppDataSize += DHCPCommon_SetOption(AppData->Options, DHCP_OPTION_SERVER_ID, sizeof(uip_ipaddr_t),
  			                                    &AppState->DHCPClient.DHCPOffer_Data.ServerIP);
  
  			/* Send the DHCP REQUEST packet */
  			uip_udp_send(AppDataSize);
  
  			/* Reset the timeout timer, progress to next state */
  			timer_reset(&AppState->DHCPClient.Timeout);
  			AppState->DHCPClient.CurrentState = DHCP_STATE_WaitForACK;
  
  			break;
  		case DHCP_STATE_WaitForACK:
  			if (!(uip_newdata()))
  			{
  				/* Check if the DHCP timeout period has expired while waiting for a response */
  				if (timer_expired(&AppState->DHCPClient.Timeout))
  				  AppState->DHCPClient.CurrentState = DHCP_STATE_SendDiscover;
  
  				break;
  			}
  
  			uint8_t RequestResponse_MessageType;
  			if ((AppData->TransactionID == DHCP_TRANSACTION_ID) &&
  			    DHCPCommon_GetOption(AppData->Options, DHCP_OPTION_MSG_TYPE, &RequestResponse_MessageType) &&
  			    (RequestResponse_MessageType == DHCP_ACK))
  			{
  				/* Set the new network parameters from the DHCP server */
  				uip_sethostaddr((uip_ipaddr_t*)&AppState->DHCPClient.DHCPOffer_Data.AllocatedIP);
  				uip_setnetmask((uip_ipaddr_t*)&AppState->DHCPClient.DHCPOffer_Data.Netmask);
  				uip_setdraddr((uip_ipaddr_t*)&AppState->DHCPClient.DHCPOffer_Data.GatewayIP);
  
  				AppState->DHCPClient.CurrentState = DHCP_STATE_AddressLeased;
  			}
  
  			break;
  	}
  }
  
  /** Fills the DHCP packet response with the appropriate BOOTP header for DHCP. This fills out all the required
   *  fields, leaving only the additional DHCP options to be added to the packet before it is sent to the DHCP server.
   *
   *  \param[out] DHCPHeader       Location in the packet buffer where the BOOTP header should be written to
   *  \param[in]  DHCPMessageType  DHCP Message type, such as DHCP_DISCOVER
   *  \param[in]  AppState         Application state of the current UDP connection
   *
   *  \return Size in bytes of the created DHCP packet
   */
  static uint16_t DHCPClientApp_FillDHCPHeader(DHCP_Header_t* const DHCPHeader,
                                               const uint8_t DHCPMessageType,
                                               uip_udp_appstate_t* const AppState)
  {
  	/* Erase existing packet data so that we start will all 0x00 DHCP header data */
   	memset(DHCPHeader, 0, sizeof(DHCP_Header_t));
  
  	/* Fill out the DHCP packet header */
  	DHCPHeader->Operation             = DHCP_OP_BOOTREQUEST;
  	DHCPHeader->HardwareType          = DHCP_HTYPE_ETHERNET;
  	DHCPHeader->HardwareAddressLength = sizeof(MACAddress);
  	DHCPHeader->Hops                  = 0;
  	DHCPHeader->TransactionID         = DHCP_TRANSACTION_ID;
  	DHCPHeader->ElapsedSeconds        = 0;
  	DHCPHeader->Flags                 = HTONS(BOOTP_BROADCAST);
  	memcpy(&DHCPHeader->ClientIP,     &uip_hostaddr,        sizeof(uip_ipaddr_t));
  	memcpy(&DHCPHeader->YourIP,       &AppState->DHCPClient.DHCPOffer_Data.AllocatedIP, sizeof(uip_ipaddr_t));
  	memcpy(&DHCPHeader->NextServerIP, &AppState->DHCPClient.DHCPOffer_Data.ServerIP,    sizeof(uip_ipaddr_t));
  	memcpy(&DHCPHeader->ClientHardwareAddress, &MACAddress, sizeof(struct uip_eth_addr));
  	DHCPHeader->Cookie                = DHCP_MAGIC_COOKIE;
  
  	/* Add a DHCP message type and terminator options to the start of the DHCP options field */
  	DHCPHeader->Options[0]            = DHCP_OPTION_MSG_TYPE;
  	DHCPHeader->Options[1]            = 1;
  	DHCPHeader->Options[2]            = DHCPMessageType;
  	DHCPHeader->Options[3]            = DHCP_OPTION_END;
  
  	/* Calculate the total number of bytes added to the outgoing packet */
  	return (sizeof(DHCP_Header_t) + 4);
  }
  
  #endif