1 | // DHCP Library v0.3 - April 25, 2009
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2 | // Author: Jordan Terrell - blog.jordanterrell.com
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3 |
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4 | #include "utility/w5500.h"
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5 |
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6 | #include <string.h>
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7 | #include <stdlib.h>
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8 | #include "Dhcp.h"
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9 | #include "Arduino.h"
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10 | #include "utility/util.h"
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11 |
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12 | int DhcpClass::beginWithDHCP(uint8_t *mac, unsigned long timeout, unsigned long responseTimeout)
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13 | {
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14 | _dhcpLeaseTime=0;
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15 | _dhcpT1=0;
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16 | _dhcpT2=0;
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17 | _lastCheck=0;
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18 | _timeout = timeout;
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19 | _responseTimeout = responseTimeout;
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20 |
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21 | // zero out _dhcpMacAddr
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22 | memset(_dhcpMacAddr, 0, 6);
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23 | reset_DHCP_lease();
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24 |
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25 | memcpy((void*)_dhcpMacAddr, (void*)mac, 6);
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26 | _dhcp_state = STATE_DHCP_START;
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27 | return request_DHCP_lease();
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28 | }
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29 |
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30 | void DhcpClass::reset_DHCP_lease(){
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31 | // zero out _dhcpSubnetMask, _dhcpGatewayIp, _dhcpLocalIp, _dhcpDhcpServerIp, _dhcpDnsServerIp
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32 | memset(_dhcpLocalIp, 0, 20);
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33 | }
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34 |
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35 | //return:0 on error, 1 if request is sent and response is received
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36 | int DhcpClass::request_DHCP_lease(){
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37 |
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38 | uint8_t messageType = 0;
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39 |
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40 |
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41 |
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42 | // Pick an initial transaction ID
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43 | _dhcpTransactionId = random(1UL, 2000UL);
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44 | _dhcpInitialTransactionId = _dhcpTransactionId;
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45 |
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46 | _dhcpUdpSocket.stop();
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47 | if (_dhcpUdpSocket.begin(DHCP_CLIENT_PORT) == 0)
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48 | {
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49 | // Couldn't get a socket
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50 | return 0;
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51 | }
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52 |
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53 | presend_DHCP();
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54 |
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55 | int result = 0;
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56 |
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57 | unsigned long startTime = millis();
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58 |
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59 | while(_dhcp_state != STATE_DHCP_LEASED)
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60 | {
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61 | if(_dhcp_state == STATE_DHCP_START)
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62 | {
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63 | //Serial.println("DHCP_START");
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64 | _dhcpTransactionId++;
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65 |
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66 | send_DHCP_MESSAGE(DHCP_DISCOVER, ((millis() - startTime) / 1000));
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67 | _dhcp_state = STATE_DHCP_DISCOVER;
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68 | }
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69 | else if(_dhcp_state == STATE_DHCP_REREQUEST){
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70 | _dhcpTransactionId++;
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71 | send_DHCP_MESSAGE(DHCP_REQUEST, ((millis() - startTime)/1000));
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72 | _dhcp_state = STATE_DHCP_REQUEST;
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73 | }
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74 | else if(_dhcp_state == STATE_DHCP_DISCOVER)
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75 | {
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76 | uint32_t respId;
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77 |
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78 | messageType = parseDHCPResponse(_responseTimeout, respId);
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79 | if(messageType == DHCP_OFFER)
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80 | {
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81 |
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82 | // We'll use the transaction ID that the offer came with,
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83 | // rather than the one we were up to
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84 | _dhcpTransactionId = respId;
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85 | send_DHCP_MESSAGE(DHCP_REQUEST, ((millis() - startTime) / 1000));
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86 | _dhcp_state = STATE_DHCP_REQUEST;
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87 | }
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88 | }
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89 | else if(_dhcp_state == STATE_DHCP_REQUEST)
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90 | {
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91 | uint32_t respId;
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92 | messageType = parseDHCPResponse(_responseTimeout, respId);
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93 | if(messageType == DHCP_ACK)
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94 | {
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95 | _dhcp_state = STATE_DHCP_LEASED;
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96 | result = 1;
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97 | //use default lease time if we didn't get it
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98 | if(_dhcpLeaseTime == 0){
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99 | _dhcpLeaseTime = DEFAULT_LEASE;
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100 | }
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101 | //calculate T1 & T2 if we didn't get it
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102 | if(_dhcpT1 == 0){
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103 | //T1 should be 50% of _dhcpLeaseTime
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104 | _dhcpT1 = _dhcpLeaseTime >> 1;
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105 | }
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106 | if(_dhcpT2 == 0){
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107 | //T2 should be 87.5% (7/8ths) of _dhcpLeaseTime
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108 | _dhcpT2 = _dhcpT1 << 1;
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109 | }
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110 | _renewInSec = _dhcpT1;
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111 | _rebindInSec = _dhcpT2;
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112 | }
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113 | else if(messageType == DHCP_NAK)
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114 | _dhcp_state = STATE_DHCP_START;
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115 | }
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116 |
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117 | if(messageType == 255)
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118 | {
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119 | messageType = 0;
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120 | _dhcp_state = STATE_DHCP_START;
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121 | }
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122 |
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123 | if(result != 1 && ((millis() - startTime) > _timeout))
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124 | break;
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125 | }
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126 |
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127 | // We're done with the socket now
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128 | _dhcpUdpSocket.stop();
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129 | _dhcpTransactionId++;
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130 |
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131 | return result;
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132 | }
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133 |
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134 | void DhcpClass::presend_DHCP()
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135 | {
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136 | }
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137 |
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138 | void DhcpClass::send_DHCP_MESSAGE(uint8_t messageType, uint16_t secondsElapsed)
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139 | {
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140 | uint8_t buffer[32];
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141 | memset(buffer, 0, 32);
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142 | IPAddress dest_addr( 255, 255, 255, 255 ); // Broadcast address
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143 |
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144 | if (-1 == _dhcpUdpSocket.beginPacket(dest_addr, DHCP_SERVER_PORT))
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145 | {
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146 | // FIXME Need to return errors
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147 | return;
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148 | }
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149 |
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150 | buffer[0] = DHCP_BOOTREQUEST; // op
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151 | buffer[1] = DHCP_HTYPE10MB; // htype
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152 | buffer[2] = DHCP_HLENETHERNET; // hlen
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153 | buffer[3] = DHCP_HOPS; // hops
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154 |
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155 | // xid
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156 | unsigned long xid = htonl(_dhcpTransactionId);
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157 | memcpy(buffer + 4, &(xid), 4);
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158 |
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159 | // 8, 9 - seconds elapsed
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160 | buffer[8] = ((secondsElapsed & 0xff00) >> 8);
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161 | buffer[9] = (secondsElapsed & 0x00ff);
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162 |
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163 | // flags
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164 | unsigned short flags = htons(DHCP_FLAGSBROADCAST);
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165 | memcpy(buffer + 10, &(flags), 2);
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166 |
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167 | // ciaddr: already zeroed
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168 | // yiaddr: already zeroed
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169 | // siaddr: already zeroed
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170 | // giaddr: already zeroed
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171 |
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172 | //put data in w5500 transmit buffer
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173 | _dhcpUdpSocket.write(buffer, 28);
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174 |
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175 | memset(buffer, 0, 32); // clear local buffer
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176 |
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177 | memcpy(buffer, _dhcpMacAddr, 6); // chaddr
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178 |
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179 | //put data in w5500 transmit buffer
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180 | _dhcpUdpSocket.write(buffer, 16);
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181 |
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182 | memset(buffer, 0, 32); // clear local buffer
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183 |
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184 | // leave zeroed out for sname && file
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185 | // put in w5500 transmit buffer x 6 (192 bytes)
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186 |
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187 | for(int i = 0; i < 6; i++) {
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188 | _dhcpUdpSocket.write(buffer, 32);
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189 | }
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190 |
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191 | // OPT - Magic Cookie
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192 | buffer[0] = (uint8_t)((MAGIC_COOKIE >> 24)& 0xFF);
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193 | buffer[1] = (uint8_t)((MAGIC_COOKIE >> 16)& 0xFF);
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194 | buffer[2] = (uint8_t)((MAGIC_COOKIE >> 8)& 0xFF);
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195 | buffer[3] = (uint8_t)(MAGIC_COOKIE& 0xFF);
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196 |
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197 | // OPT - message type
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198 | buffer[4] = dhcpMessageType;
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199 | buffer[5] = 0x01;
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200 | buffer[6] = messageType; //DHCP_REQUEST;
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201 |
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202 | // OPT - client identifier
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203 | buffer[7] = dhcpClientIdentifier;
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204 | buffer[8] = 0x07;
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205 | buffer[9] = 0x01;
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206 | memcpy(buffer + 10, _dhcpMacAddr, 6);
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207 |
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208 | // OPT - host name
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209 | buffer[16] = hostName;
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210 | buffer[17] = strlen(HOST_NAME) + 6; // length of hostname + last 3 bytes of mac address
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211 | strcpy((char*)&(buffer[18]), HOST_NAME);
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212 |
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213 | printByte((char*)&(buffer[24]), _dhcpMacAddr[3]);
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214 | printByte((char*)&(buffer[26]), _dhcpMacAddr[4]);
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215 | printByte((char*)&(buffer[28]), _dhcpMacAddr[5]);
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216 |
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217 | //put data in w5500 transmit buffer
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218 | _dhcpUdpSocket.write(buffer, 30);
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219 |
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220 | if(messageType == DHCP_REQUEST)
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221 | {
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222 | buffer[0] = dhcpRequestedIPaddr;
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223 | buffer[1] = 0x04;
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224 | buffer[2] = _dhcpLocalIp[0];
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225 | buffer[3] = _dhcpLocalIp[1];
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226 | buffer[4] = _dhcpLocalIp[2];
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227 | buffer[5] = _dhcpLocalIp[3];
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228 |
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229 | buffer[6] = dhcpServerIdentifier;
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230 | buffer[7] = 0x04;
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231 | buffer[8] = _dhcpDhcpServerIp[0];
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232 | buffer[9] = _dhcpDhcpServerIp[1];
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233 | buffer[10] = _dhcpDhcpServerIp[2];
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234 | buffer[11] = _dhcpDhcpServerIp[3];
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235 |
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236 | //put data in w5500 transmit buffer
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237 | _dhcpUdpSocket.write(buffer, 12);
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238 | }
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239 |
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240 | buffer[0] = dhcpParamRequest;
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241 | buffer[1] = 0x06;
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242 | buffer[2] = subnetMask;
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243 | buffer[3] = routersOnSubnet;
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244 | buffer[4] = dns;
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245 | buffer[5] = domainName;
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246 | buffer[6] = dhcpT1value;
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247 | buffer[7] = dhcpT2value;
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248 | buffer[8] = endOption;
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249 |
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250 | //put data in w5500 transmit buffer
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251 | _dhcpUdpSocket.write(buffer, 9);
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252 |
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253 | _dhcpUdpSocket.endPacket();
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254 | }
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255 |
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256 | uint8_t DhcpClass::parseDHCPResponse(unsigned long responseTimeout, uint32_t& transactionId)
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257 | {
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258 | uint8_t type = 0;
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259 | uint8_t opt_len = 0;
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260 |
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261 | unsigned long startTime = millis();
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262 |
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263 |
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264 |
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265 | while(_dhcpUdpSocket.parsePacket() <= 0)
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266 | {
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267 | if((millis() - startTime) > responseTimeout)
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268 | {
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269 |
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270 | return 255;
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271 | }
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272 | delay(50);
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273 | }
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274 |
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275 | // start reading in the packet
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276 | RIP_MSG_FIXED fixedMsg;
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277 | _dhcpUdpSocket.read((uint8_t*)&fixedMsg, sizeof(RIP_MSG_FIXED));
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278 |
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279 | if(fixedMsg.op == DHCP_BOOTREPLY && _dhcpUdpSocket.remotePort() == DHCP_SERVER_PORT)
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280 | {
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281 | transactionId = ntohl(fixedMsg.xid);
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282 | if(memcmp(fixedMsg.chaddr, _dhcpMacAddr, 6) != 0 || (transactionId < _dhcpInitialTransactionId) || (transactionId > _dhcpTransactionId))
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283 | {
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284 | // Need to read the rest of the packet here regardless
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285 | _dhcpUdpSocket.flush();
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286 | return 0;
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287 | }
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288 |
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289 | memcpy(_dhcpLocalIp, fixedMsg.yiaddr, 4);
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290 |
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291 | // Skip to the option part
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292 | // Doing this a byte at a time so we don't have to put a big buffer
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293 | // on the stack (as we don't have lots of memory lying around)
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294 | for (int i =0; i < (240 - (int)sizeof(RIP_MSG_FIXED)); i++)
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295 | {
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296 | _dhcpUdpSocket.read(); // we don't care about the returned byte
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297 | }
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298 |
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299 | while (_dhcpUdpSocket.available() > 0)
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300 | {
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301 | switch (_dhcpUdpSocket.read())
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302 | {
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303 | case endOption :
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304 |
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305 | break;
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306 |
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307 | case padOption :
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308 |
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309 | break;
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310 |
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311 | case dhcpMessageType :
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312 |
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313 | opt_len = _dhcpUdpSocket.read();
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314 | type = _dhcpUdpSocket.read();
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315 | break;
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316 |
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317 | case subnetMask :
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318 |
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319 | opt_len = _dhcpUdpSocket.read();
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320 | _dhcpUdpSocket.read(_dhcpSubnetMask, 4);
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321 | break;
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322 |
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323 | case routersOnSubnet :
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324 |
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325 | opt_len = _dhcpUdpSocket.read();
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326 | _dhcpUdpSocket.read(_dhcpGatewayIp, 4);
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327 | for (int i = 0; i < opt_len-4; i++)
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328 | {
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329 | _dhcpUdpSocket.read();
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330 | }
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331 | break;
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332 |
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333 | case dns :
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334 |
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335 | opt_len = _dhcpUdpSocket.read();
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336 | _dhcpUdpSocket.read(_dhcpDnsServerIp, 4);
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337 | for (int i = 0; i < opt_len-4; i++)
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338 | {
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339 | _dhcpUdpSocket.read();
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340 | }
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341 | break;
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342 |
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343 | case dhcpServerIdentifier :
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344 |
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345 | opt_len = _dhcpUdpSocket.read();
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346 | if(((_dhcpDhcpServerIp[0] == 0) && (_dhcpDhcpServerIp[1] == 0) && (_dhcpDhcpServerIp[2] == 0) && (_dhcpDhcpServerIp[3] == 0)) || (IPAddress(_dhcpDhcpServerIp) == _dhcpUdpSocket.remoteIP()))
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347 | {
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348 | _dhcpUdpSocket.read(_dhcpDhcpServerIp, sizeof(_dhcpDhcpServerIp));
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349 | }
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350 | else
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351 | {
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352 | // Skip over the rest of this option
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353 | while (opt_len--)
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354 | {
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355 | _dhcpUdpSocket.read();
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356 | }
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357 | }
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358 | break;
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359 |
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360 | case dhcpT1value :
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361 |
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362 | opt_len = _dhcpUdpSocket.read();
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363 | _dhcpUdpSocket.read((uint8_t*)&_dhcpT1, sizeof(_dhcpT1));
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364 | _dhcpT1 = ntohl(_dhcpT1);
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365 | break;
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366 |
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367 | case dhcpT2value :
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368 |
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369 | opt_len = _dhcpUdpSocket.read();
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370 | _dhcpUdpSocket.read((uint8_t*)&_dhcpT2, sizeof(_dhcpT2));
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371 | _dhcpT2 = ntohl(_dhcpT2);
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372 | break;
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373 |
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374 | case dhcpIPaddrLeaseTime :
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375 |
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376 | opt_len = _dhcpUdpSocket.read();
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377 | _dhcpUdpSocket.read((uint8_t*)&_dhcpLeaseTime, sizeof(_dhcpLeaseTime));
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378 | _dhcpLeaseTime = ntohl(_dhcpLeaseTime);
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379 | _renewInSec = _dhcpLeaseTime;
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380 | break;
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381 |
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382 | default :
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383 |
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384 | opt_len = _dhcpUdpSocket.read();
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385 | // Skip over the rest of this option
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386 | while (opt_len--)
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387 | {
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388 | _dhcpUdpSocket.read();
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389 | }
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390 | break;
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391 | }
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392 | }
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393 | }
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394 |
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395 | // Need to skip to end of the packet regardless here
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396 | _dhcpUdpSocket.flush();
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397 |
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398 | return type;
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399 | }
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400 |
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401 |
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402 | /*
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403 | returns:
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404 | 0/DHCP_CHECK_NONE: nothing happened
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405 | 1/DHCP_CHECK_RENEW_FAIL: renew failed
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406 | 2/DHCP_CHECK_RENEW_OK: renew success
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407 | 3/DHCP_CHECK_REBIND_FAIL: rebind fail
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408 | 4/DHCP_CHECK_REBIND_OK: rebind success
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409 | */
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410 | int DhcpClass::checkLease(){
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411 | //this uses a signed / unsigned trick to deal with millis overflow
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412 | unsigned long now = millis();
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413 | signed long snow = (long)now;
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414 | int rc=DHCP_CHECK_NONE;
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415 | if (_lastCheck != 0){
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416 | signed long factor;
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417 | //calc how many ms past the timeout we are
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418 | factor = snow - (long)_secTimeout;
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419 | //if on or passed the timeout, reduce the counters
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420 | if ( factor >= 0 ){
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421 | //next timeout should be now plus 1000 ms minus parts of second in factor
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422 | _secTimeout = snow + 1000 - factor % 1000;
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423 | //how many seconds late are we, minimum 1
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424 | factor = factor / 1000 +1;
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425 |
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426 | //reduce the counters by that mouch
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427 | //if we can assume that the cycle time (factor) is fairly constant
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428 | //and if the remainder is less than cycle time * 2
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429 | //do it early instead of late
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430 | if(_renewInSec < factor*2 )
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431 | _renewInSec = 0;
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432 | else
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433 | _renewInSec -= factor;
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434 |
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435 | if(_rebindInSec < factor*2 )
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436 | _rebindInSec = 0;
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437 | else
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438 | _rebindInSec -= factor;
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439 | }
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440 |
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441 | //if we have a lease but should renew, do it
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442 | if (_dhcp_state == STATE_DHCP_LEASED && _renewInSec <=0){
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443 | _dhcp_state = STATE_DHCP_REREQUEST;
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444 | rc = 1 + request_DHCP_lease();
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445 | }
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446 |
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447 | //if we have a lease or is renewing but should bind, do it
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448 | if( (_dhcp_state == STATE_DHCP_LEASED || _dhcp_state == STATE_DHCP_START) && _rebindInSec <=0){
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449 | //this should basically restart completely
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450 | _dhcp_state = STATE_DHCP_START;
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451 | reset_DHCP_lease();
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452 | rc = 3 + request_DHCP_lease();
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453 | }
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454 | }
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455 | else{
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456 | _secTimeout = snow + 1000;
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457 | }
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458 |
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459 | _lastCheck = now;
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460 | return rc;
|
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461 | }
|
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462 |
|
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463 | IPAddress DhcpClass::getLocalIp()
|
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464 | {
|
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465 | return IPAddress(_dhcpLocalIp);
|
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466 | }
|
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467 |
|
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468 | IPAddress DhcpClass::getSubnetMask()
|
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469 | {
|
---|
470 | return IPAddress(_dhcpSubnetMask);
|
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471 | }
|
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472 |
|
---|
473 | IPAddress DhcpClass::getGatewayIp()
|
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474 | {
|
---|
475 | return IPAddress(_dhcpGatewayIp);
|
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476 | }
|
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477 |
|
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478 | IPAddress DhcpClass::getDhcpServerIp()
|
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479 | {
|
---|
480 | return IPAddress(_dhcpDhcpServerIp);
|
---|
481 | }
|
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482 |
|
---|
483 | IPAddress DhcpClass::getDnsServerIp()
|
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484 | {
|
---|
485 | return IPAddress(_dhcpDnsServerIp);
|
---|
486 | }
|
---|
487 |
|
---|
488 | void DhcpClass::printByte(char * buf, uint8_t n ) {
|
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489 | char *str = &buf[1];
|
---|
490 | buf[0]='0';
|
---|
491 | do {
|
---|
492 | unsigned long m = n;
|
---|
493 | n /= 16;
|
---|
494 | char c = m - 16 * n;
|
---|
495 | *str-- = c < 10 ? c + '0' : c + 'A' - 10;
|
---|
496 | } while(n);
|
---|
497 | }
|
---|