A stack which works with or without an Mbed os library. Provides IPv4 or IPv6 with a full 1500 byte buffer.
Dependents: oldheating gps motorhome heating
udp/dhcp.cpp@28:edc17eeb4142, 2017-07-24 (annotated)
- Committer:
- andrewboyson
- Date:
- Mon Jul 24 15:27:36 2017 +0000
- Revision:
- 28:edc17eeb4142
- Parent:
- 14:e75a59c1123d
- Child:
- 29:39277bf2003d
Added check of DHCP MAC address to prevent two systems picking up the same broadcast response.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
andrewboyson | 10:f0854784e960 | 1 | #include "mbed.h" |
andrewboyson | 10:f0854784e960 | 2 | #include "log.h" |
andrewboyson | 10:f0854784e960 | 3 | #include "net.h" |
andrewboyson | 14:e75a59c1123d | 4 | #include "eth.h" |
andrewboyson | 14:e75a59c1123d | 5 | #include "ip4.h" |
andrewboyson | 13:9cd54f7db57a | 6 | #include "mac.h" |
andrewboyson | 10:f0854784e960 | 7 | #include "udp.h" |
andrewboyson | 10:f0854784e960 | 8 | |
andrewboyson | 10:f0854784e960 | 9 | #define DEBUG false |
andrewboyson | 10:f0854784e960 | 10 | |
andrewboyson | 10:f0854784e960 | 11 | #define REQUEST 1 |
andrewboyson | 10:f0854784e960 | 12 | #define REPLY 2 |
andrewboyson | 10:f0854784e960 | 13 | |
andrewboyson | 10:f0854784e960 | 14 | #define DHCPDISCOVER 1 |
andrewboyson | 10:f0854784e960 | 15 | #define DHCPOFFER 2 |
andrewboyson | 10:f0854784e960 | 16 | #define DHCPREQUEST 3 |
andrewboyson | 10:f0854784e960 | 17 | #define DHCPDECLINE 4 |
andrewboyson | 10:f0854784e960 | 18 | #define DHCPACK 5 |
andrewboyson | 10:f0854784e960 | 19 | #define DHCPNAK 6 |
andrewboyson | 10:f0854784e960 | 20 | #define DHCPRELEASE 7 |
andrewboyson | 10:f0854784e960 | 21 | #define DHCPINFORM 8 |
andrewboyson | 10:f0854784e960 | 22 | |
andrewboyson | 10:f0854784e960 | 23 | #define ID 75648 |
andrewboyson | 10:f0854784e960 | 24 | #define COOKIE 0x63825363 |
andrewboyson | 10:f0854784e960 | 25 | #define HEADER_LENGTH 240 |
andrewboyson | 10:f0854784e960 | 26 | |
andrewboyson | 10:f0854784e960 | 27 | __packed struct header |
andrewboyson | 10:f0854784e960 | 28 | { |
andrewboyson | 10:f0854784e960 | 29 | uint8_t op; |
andrewboyson | 10:f0854784e960 | 30 | uint8_t htype; |
andrewboyson | 10:f0854784e960 | 31 | uint8_t hlen; |
andrewboyson | 10:f0854784e960 | 32 | uint8_t hops; |
andrewboyson | 10:f0854784e960 | 33 | |
andrewboyson | 10:f0854784e960 | 34 | uint32_t xid; |
andrewboyson | 10:f0854784e960 | 35 | |
andrewboyson | 10:f0854784e960 | 36 | uint16_t secs; |
andrewboyson | 10:f0854784e960 | 37 | uint16_t flags; |
andrewboyson | 10:f0854784e960 | 38 | |
andrewboyson | 10:f0854784e960 | 39 | uint32_t ciaddr; |
andrewboyson | 10:f0854784e960 | 40 | uint32_t yiaddr; |
andrewboyson | 10:f0854784e960 | 41 | uint32_t siaddr; |
andrewboyson | 10:f0854784e960 | 42 | uint32_t giaddr; |
andrewboyson | 10:f0854784e960 | 43 | |
andrewboyson | 10:f0854784e960 | 44 | uint8_t chaddr[16]; |
andrewboyson | 10:f0854784e960 | 45 | |
andrewboyson | 10:f0854784e960 | 46 | char legacy[192]; |
andrewboyson | 10:f0854784e960 | 47 | |
andrewboyson | 10:f0854784e960 | 48 | uint32_t cookie; |
andrewboyson | 10:f0854784e960 | 49 | }; |
andrewboyson | 10:f0854784e960 | 50 | |
andrewboyson | 10:f0854784e960 | 51 | #define REPEAT_DELAY_TIME 60 |
andrewboyson | 10:f0854784e960 | 52 | static uint32_t delayTime = 10000000; //Reset whenever a message is sent and blocks another send until count exceeds REPEAT_DELAY_TIME |
andrewboyson | 10:f0854784e960 | 53 | static uint32_t elapsedTime = 0; //Reset whenever an IP address request has been acknowledged |
andrewboyson | 10:f0854784e960 | 54 | void DhcpTick() |
andrewboyson | 10:f0854784e960 | 55 | { |
andrewboyson | 10:f0854784e960 | 56 | elapsedTime++; |
andrewboyson | 10:f0854784e960 | 57 | delayTime++; |
andrewboyson | 10:f0854784e960 | 58 | } |
andrewboyson | 10:f0854784e960 | 59 | |
andrewboyson | 10:f0854784e960 | 60 | static uint8_t dhcpMessageType = 0; |
andrewboyson | 10:f0854784e960 | 61 | uint32_t DhcpLeaseTime = 0; |
andrewboyson | 10:f0854784e960 | 62 | uint32_t DhcpServer = 0; |
andrewboyson | 10:f0854784e960 | 63 | uint32_t DhcpRouter = 0; |
andrewboyson | 10:f0854784e960 | 64 | uint32_t DhcpSubnetMask = 0; |
andrewboyson | 10:f0854784e960 | 65 | uint32_t DhcpNtp = 0; |
andrewboyson | 10:f0854784e960 | 66 | uint32_t DhcpRenewalT1 = 0; |
andrewboyson | 10:f0854784e960 | 67 | uint32_t DhcpRenewalT2 = 0; |
andrewboyson | 10:f0854784e960 | 68 | uint32_t DhcpBroadcastIp = 0; |
andrewboyson | 10:f0854784e960 | 69 | uint32_t DhcpLocalIp = 0; |
andrewboyson | 10:f0854784e960 | 70 | uint32_t DhcpDnsServer = 0; |
andrewboyson | 10:f0854784e960 | 71 | char DhcpDomainName[20]; |
andrewboyson | 10:f0854784e960 | 72 | char DhcpHostName[20]; |
andrewboyson | 10:f0854784e960 | 73 | static uint32_t readOption32(char** pp) |
andrewboyson | 10:f0854784e960 | 74 | { |
andrewboyson | 10:f0854784e960 | 75 | uint32_t value = 0; |
andrewboyson | 10:f0854784e960 | 76 | char* p = *pp; |
andrewboyson | 10:f0854784e960 | 77 | int len = *++p; |
andrewboyson | 10:f0854784e960 | 78 | if (len >= 4) |
andrewboyson | 10:f0854784e960 | 79 | { |
andrewboyson | 10:f0854784e960 | 80 | value = *++p << 24; |
andrewboyson | 10:f0854784e960 | 81 | value |= *++p << 16; |
andrewboyson | 10:f0854784e960 | 82 | value |= *++p << 8; |
andrewboyson | 10:f0854784e960 | 83 | value |= *++p << 0; |
andrewboyson | 10:f0854784e960 | 84 | } |
andrewboyson | 10:f0854784e960 | 85 | *pp += len + 1; |
andrewboyson | 10:f0854784e960 | 86 | return value; |
andrewboyson | 10:f0854784e960 | 87 | } |
andrewboyson | 10:f0854784e960 | 88 | static uint32_t readIp(char** pp) |
andrewboyson | 10:f0854784e960 | 89 | { |
andrewboyson | 10:f0854784e960 | 90 | uint32_t value = 0; |
andrewboyson | 10:f0854784e960 | 91 | char* p = *pp; |
andrewboyson | 10:f0854784e960 | 92 | int len = *++p; |
andrewboyson | 10:f0854784e960 | 93 | if (len >= 4) |
andrewboyson | 10:f0854784e960 | 94 | { |
andrewboyson | 10:f0854784e960 | 95 | value = *++p << 0; |
andrewboyson | 10:f0854784e960 | 96 | value |= *++p << 8; |
andrewboyson | 10:f0854784e960 | 97 | value |= *++p << 16; |
andrewboyson | 10:f0854784e960 | 98 | value |= *++p << 24; |
andrewboyson | 10:f0854784e960 | 99 | } |
andrewboyson | 10:f0854784e960 | 100 | *pp += len + 1; |
andrewboyson | 10:f0854784e960 | 101 | return value; |
andrewboyson | 10:f0854784e960 | 102 | } |
andrewboyson | 10:f0854784e960 | 103 | static void readString(char** pp, char* pText) |
andrewboyson | 10:f0854784e960 | 104 | { |
andrewboyson | 10:f0854784e960 | 105 | char* p = *pp; |
andrewboyson | 10:f0854784e960 | 106 | int len = *++p; |
andrewboyson | 10:f0854784e960 | 107 | for (int i = 0; i < len; i++) pText[i] = *++p; |
andrewboyson | 10:f0854784e960 | 108 | *pp += len + 1; |
andrewboyson | 10:f0854784e960 | 109 | } |
andrewboyson | 10:f0854784e960 | 110 | static void readOptions(int size, char * pOptions) |
andrewboyson | 10:f0854784e960 | 111 | { |
andrewboyson | 10:f0854784e960 | 112 | int len = 0; |
andrewboyson | 10:f0854784e960 | 113 | char* p = pOptions; |
andrewboyson | 10:f0854784e960 | 114 | char* pE = pOptions + size; |
andrewboyson | 10:f0854784e960 | 115 | while( p < pE) |
andrewboyson | 10:f0854784e960 | 116 | { |
andrewboyson | 10:f0854784e960 | 117 | switch (*p) |
andrewboyson | 10:f0854784e960 | 118 | { |
andrewboyson | 10:f0854784e960 | 119 | case 0: break; //NOP |
andrewboyson | 10:f0854784e960 | 120 | case 255: return; //End of options |
andrewboyson | 10:f0854784e960 | 121 | case 1: DhcpSubnetMask = readIp(&p); break; //Subnet Mask |
andrewboyson | 10:f0854784e960 | 122 | case 3: DhcpRouter = readIp(&p); break; //Router |
andrewboyson | 10:f0854784e960 | 123 | case 6: DhcpDnsServer = readIp(&p); break; //DNS server |
andrewboyson | 10:f0854784e960 | 124 | case 12: readString(&p, DhcpHostName); break; //Host name |
andrewboyson | 10:f0854784e960 | 125 | case 15: readString(&p, DhcpDomainName); break; //Domain name |
andrewboyson | 10:f0854784e960 | 126 | case 19: len = *++p; p+= len; break; //IP forwarding yes/no |
andrewboyson | 10:f0854784e960 | 127 | case 28: DhcpBroadcastIp = readIp(&p); break; //Broadcast IP |
andrewboyson | 10:f0854784e960 | 128 | case 42: DhcpNtp = readIp(&p); break; //NTP |
andrewboyson | 10:f0854784e960 | 129 | case 44: len = *++p; p+= len; break; //NetBIOS name server |
andrewboyson | 10:f0854784e960 | 130 | case 45: len = *++p; p+= len; break; //NetBIOS datagram server |
andrewboyson | 10:f0854784e960 | 131 | case 46: len = *++p; p+= len; break; //NetBIOS node type |
andrewboyson | 10:f0854784e960 | 132 | case 47: len = *++p; p+= len; break; //NetBIOS scope |
andrewboyson | 10:f0854784e960 | 133 | case 53: len = *++p; dhcpMessageType = *++p; break; //DHCP message type |
andrewboyson | 10:f0854784e960 | 134 | case 51: DhcpLeaseTime = readOption32(&p); break; //Address lease time |
andrewboyson | 10:f0854784e960 | 135 | case 54: DhcpServer = readIp(&p); break; //DHCP server |
andrewboyson | 10:f0854784e960 | 136 | case 58: DhcpRenewalT1 = readOption32(&p); break; //T1 |
andrewboyson | 10:f0854784e960 | 137 | case 59: DhcpRenewalT2 = readOption32(&p); break; //T2 |
andrewboyson | 10:f0854784e960 | 138 | default: |
andrewboyson | 10:f0854784e960 | 139 | if (DEBUG) LogTimeF("Ignoring option %d\r\n", *p); |
andrewboyson | 10:f0854784e960 | 140 | len = *++p; |
andrewboyson | 10:f0854784e960 | 141 | p += len; |
andrewboyson | 10:f0854784e960 | 142 | return; |
andrewboyson | 10:f0854784e960 | 143 | } |
andrewboyson | 10:f0854784e960 | 144 | p++; |
andrewboyson | 10:f0854784e960 | 145 | } |
andrewboyson | 10:f0854784e960 | 146 | } |
andrewboyson | 10:f0854784e960 | 147 | static void writeIp(uint8_t code, uint32_t value, char** pp) |
andrewboyson | 10:f0854784e960 | 148 | { |
andrewboyson | 10:f0854784e960 | 149 | if (!value) return; |
andrewboyson | 10:f0854784e960 | 150 | |
andrewboyson | 10:f0854784e960 | 151 | char* p = *pp; |
andrewboyson | 10:f0854784e960 | 152 | |
andrewboyson | 10:f0854784e960 | 153 | *p++ = code; |
andrewboyson | 10:f0854784e960 | 154 | *p++ = 4; |
andrewboyson | 10:f0854784e960 | 155 | *p++ = (value & 0x000000FF) >> 0; |
andrewboyson | 10:f0854784e960 | 156 | *p++ = (value & 0x0000FF00) >> 8; |
andrewboyson | 10:f0854784e960 | 157 | *p++ = (value & 0x00FF0000) >> 16; |
andrewboyson | 10:f0854784e960 | 158 | *p++ = (value & 0xFF000000) >> 24; |
andrewboyson | 10:f0854784e960 | 159 | |
andrewboyson | 10:f0854784e960 | 160 | *pp += 6; |
andrewboyson | 10:f0854784e960 | 161 | } |
andrewboyson | 10:f0854784e960 | 162 | int sendRequest(void* pPacket, uint8_t code, uint32_t srvIp, uint32_t reqIp) |
andrewboyson | 10:f0854784e960 | 163 | { |
andrewboyson | 10:f0854784e960 | 164 | |
andrewboyson | 10:f0854784e960 | 165 | switch (code) |
andrewboyson | 10:f0854784e960 | 166 | { |
andrewboyson | 10:f0854784e960 | 167 | case DHCPDISCOVER: |
andrewboyson | 10:f0854784e960 | 168 | if (DEBUG) LogTimeF("DHCP -> discover"); |
andrewboyson | 10:f0854784e960 | 169 | break; |
andrewboyson | 10:f0854784e960 | 170 | case DHCPREQUEST: |
andrewboyson | 10:f0854784e960 | 171 | if (DEBUG) LogTimeF("DHCP -> request"); |
andrewboyson | 10:f0854784e960 | 172 | break; |
andrewboyson | 10:f0854784e960 | 173 | default: |
andrewboyson | 10:f0854784e960 | 174 | LogTimeF("DHCP -> unknown message %d", code); |
andrewboyson | 10:f0854784e960 | 175 | break; |
andrewboyson | 10:f0854784e960 | 176 | } |
andrewboyson | 10:f0854784e960 | 177 | if (DEBUG) |
andrewboyson | 10:f0854784e960 | 178 | { |
andrewboyson | 10:f0854784e960 | 179 | char text[20]; |
andrewboyson | 14:e75a59c1123d | 180 | Ip4AddressToString(srvIp, sizeof(text), text); |
andrewboyson | 10:f0854784e960 | 181 | LogF(" server=%s", text); |
andrewboyson | 14:e75a59c1123d | 182 | Ip4AddressToString(reqIp, sizeof(text), text); |
andrewboyson | 10:f0854784e960 | 183 | LogF(" request=%s", text); |
andrewboyson | 14:e75a59c1123d | 184 | Ip4AddressToString(DhcpLocalIp, sizeof(text), text); |
andrewboyson | 10:f0854784e960 | 185 | LogF(" local=%s\r\n", text); |
andrewboyson | 10:f0854784e960 | 186 | } |
andrewboyson | 10:f0854784e960 | 187 | |
andrewboyson | 10:f0854784e960 | 188 | bool broadcast = DhcpLocalIp == 0; |
andrewboyson | 10:f0854784e960 | 189 | uint16_t flags = 0; |
andrewboyson | 10:f0854784e960 | 190 | if (broadcast) flags |= 0x0080; //0x8000 on the net == 0x0080 in little endian |
andrewboyson | 10:f0854784e960 | 191 | struct header* pHeader = (header*)pPacket; |
andrewboyson | 10:f0854784e960 | 192 | pHeader->op = REQUEST; |
andrewboyson | 10:f0854784e960 | 193 | pHeader->htype = ETHERNET; |
andrewboyson | 10:f0854784e960 | 194 | pHeader->hlen = 6; |
andrewboyson | 10:f0854784e960 | 195 | pHeader->hops = 0; |
andrewboyson | 10:f0854784e960 | 196 | pHeader->xid = ID; //Randomly chosed transaction id used to associate messages to responses |
andrewboyson | 10:f0854784e960 | 197 | pHeader->secs = 0; //Seconds since started to boot |
andrewboyson | 10:f0854784e960 | 198 | pHeader->flags = flags; //Broadcast (1) Unicast (0) |
andrewboyson | 10:f0854784e960 | 199 | pHeader->ciaddr = DhcpLocalIp; //'Client' address set by client or 0 if don't know address |
andrewboyson | 10:f0854784e960 | 200 | pHeader->yiaddr = 0; //'Your' address returned by server |
andrewboyson | 10:f0854784e960 | 201 | pHeader->siaddr = srvIp; //'Server' address to use if required |
andrewboyson | 10:f0854784e960 | 202 | pHeader->giaddr = 0; //'Gateway' address |
andrewboyson | 13:9cd54f7db57a | 203 | memcpy(pHeader->chaddr, MacLocal, 6); //'Client hardware' address. 6 bytes for ethernet |
andrewboyson | 10:f0854784e960 | 204 | memset(pHeader->legacy, 0, 192); //BootP legacy fill with zeros |
andrewboyson | 10:f0854784e960 | 205 | pHeader->cookie = NetToHost32(COOKIE); //Magic cookie |
andrewboyson | 10:f0854784e960 | 206 | |
andrewboyson | 10:f0854784e960 | 207 | char* pOptions = (char*)pPacket + HEADER_LENGTH; |
andrewboyson | 10:f0854784e960 | 208 | char* p = pOptions; |
andrewboyson | 10:f0854784e960 | 209 | *p++ = 53; //Message code |
andrewboyson | 10:f0854784e960 | 210 | *p++ = 1; |
andrewboyson | 10:f0854784e960 | 211 | *p++ = code; |
andrewboyson | 10:f0854784e960 | 212 | |
andrewboyson | 10:f0854784e960 | 213 | writeIp(50, reqIp, &p); //Requested IP |
andrewboyson | 10:f0854784e960 | 214 | writeIp(54, srvIp, &p); //Server ip |
andrewboyson | 10:f0854784e960 | 215 | |
andrewboyson | 10:f0854784e960 | 216 | *p++ = 255; //End of options |
andrewboyson | 10:f0854784e960 | 217 | |
andrewboyson | 10:f0854784e960 | 218 | delayTime = 0; |
andrewboyson | 10:f0854784e960 | 219 | return HEADER_LENGTH + p - pOptions; |
andrewboyson | 10:f0854784e960 | 220 | } |
andrewboyson | 10:f0854784e960 | 221 | int DhcpHandleResponse(int* pSize, void* pPacket) |
andrewboyson | 10:f0854784e960 | 222 | { |
andrewboyson | 10:f0854784e960 | 223 | struct header* pHeader = (header*)pPacket; |
andrewboyson | 10:f0854784e960 | 224 | |
andrewboyson | 10:f0854784e960 | 225 | uint8_t op = pHeader->op; |
andrewboyson | 10:f0854784e960 | 226 | uint8_t htype = pHeader->htype; |
andrewboyson | 10:f0854784e960 | 227 | uint8_t hlen = pHeader->hlen; |
andrewboyson | 10:f0854784e960 | 228 | |
andrewboyson | 10:f0854784e960 | 229 | uint32_t xid = pHeader->xid; //Randomly chosed transaction id used to associate messages to responses |
andrewboyson | 10:f0854784e960 | 230 | |
andrewboyson | 10:f0854784e960 | 231 | uint16_t secs = NetToHost16(pHeader->secs); |
andrewboyson | 10:f0854784e960 | 232 | uint16_t flags = NetToHost16(pHeader->flags); |
andrewboyson | 10:f0854784e960 | 233 | |
andrewboyson | 10:f0854784e960 | 234 | uint32_t yiaddr = pHeader->yiaddr; |
andrewboyson | 10:f0854784e960 | 235 | uint32_t siaddr = pHeader->siaddr; |
andrewboyson | 10:f0854784e960 | 236 | uint32_t cookie = NetToHost32(pHeader->cookie); |
andrewboyson | 10:f0854784e960 | 237 | |
andrewboyson | 28:edc17eeb4142 | 238 | if (op != REPLY) return DO_NOTHING; |
andrewboyson | 28:edc17eeb4142 | 239 | if (htype != ETHERNET) return DO_NOTHING; |
andrewboyson | 28:edc17eeb4142 | 240 | if (hlen != 6) return DO_NOTHING; |
andrewboyson | 28:edc17eeb4142 | 241 | if (memcmp(pHeader->chaddr, MacLocal, 6)) return DO_NOTHING; |
andrewboyson | 28:edc17eeb4142 | 242 | if (xid != ID) return DO_NOTHING; |
andrewboyson | 28:edc17eeb4142 | 243 | if (cookie != COOKIE) return DO_NOTHING; |
andrewboyson | 10:f0854784e960 | 244 | |
andrewboyson | 10:f0854784e960 | 245 | char* pOptions = (char*)pPacket + HEADER_LENGTH; |
andrewboyson | 10:f0854784e960 | 246 | readOptions(*pSize - HEADER_LENGTH, pOptions); |
andrewboyson | 10:f0854784e960 | 247 | |
andrewboyson | 10:f0854784e960 | 248 | char text[30]; |
andrewboyson | 10:f0854784e960 | 249 | switch (dhcpMessageType) |
andrewboyson | 10:f0854784e960 | 250 | { |
andrewboyson | 10:f0854784e960 | 251 | case DHCPOFFER: |
andrewboyson | 14:e75a59c1123d | 252 | Ip4AddressToString(yiaddr, sizeof(text), text); |
andrewboyson | 10:f0854784e960 | 253 | if (DEBUG) LogTimeF("DHCP <- offer ip %s\r\n", text); |
andrewboyson | 10:f0854784e960 | 254 | *pSize =sendRequest(pPacket, DHCPREQUEST, siaddr, yiaddr); |
andrewboyson | 10:f0854784e960 | 255 | return BROADCAST; |
andrewboyson | 10:f0854784e960 | 256 | case DHCPACK: |
andrewboyson | 14:e75a59c1123d | 257 | Ip4AddressToString(yiaddr, sizeof(text), text); |
andrewboyson | 10:f0854784e960 | 258 | if (DEBUG) LogTimeF("DHCP <- ack ip %s\r\n", text); |
andrewboyson | 10:f0854784e960 | 259 | DhcpLocalIp = yiaddr; |
andrewboyson | 10:f0854784e960 | 260 | elapsedTime = 0; |
andrewboyson | 10:f0854784e960 | 261 | break; |
andrewboyson | 10:f0854784e960 | 262 | case DHCPNAK: |
andrewboyson | 14:e75a59c1123d | 263 | Ip4AddressToString(yiaddr, sizeof(text), text); |
andrewboyson | 10:f0854784e960 | 264 | if (DEBUG) LogTimeF("DHCP <- nack ip %s\r\n", text); |
andrewboyson | 10:f0854784e960 | 265 | break; |
andrewboyson | 10:f0854784e960 | 266 | default: |
andrewboyson | 10:f0854784e960 | 267 | LogTimeF("DHCP <- unknown message %d\r\n", dhcpMessageType); |
andrewboyson | 10:f0854784e960 | 268 | break; |
andrewboyson | 10:f0854784e960 | 269 | } |
andrewboyson | 10:f0854784e960 | 270 | return DO_NOTHING; |
andrewboyson | 10:f0854784e960 | 271 | } |
andrewboyson | 10:f0854784e960 | 272 | |
andrewboyson | 10:f0854784e960 | 273 | int DhcpPollForRequestToSend(void* pPacket, int* pSize) |
andrewboyson | 10:f0854784e960 | 274 | { |
andrewboyson | 10:f0854784e960 | 275 | if (delayTime < REPEAT_DELAY_TIME) return DO_NOTHING; //Don't retry within the delay time |
andrewboyson | 10:f0854784e960 | 276 | |
andrewboyson | 10:f0854784e960 | 277 | if (DhcpLocalIp && elapsedTime < (DhcpLeaseTime >> 1)) return 0; //Do nothing if have address and within T1 |
andrewboyson | 10:f0854784e960 | 278 | |
andrewboyson | 10:f0854784e960 | 279 | *pSize = 0; |
andrewboyson | 10:f0854784e960 | 280 | |
andrewboyson | 10:f0854784e960 | 281 | if (DhcpLocalIp && elapsedTime < DhcpLeaseTime) |
andrewboyson | 10:f0854784e960 | 282 | { |
andrewboyson | 10:f0854784e960 | 283 | *pSize = sendRequest(pPacket, DHCPREQUEST, DhcpServer, DhcpLocalIp); //if within T2 then send request to the server - not broadcast |
andrewboyson | 10:f0854784e960 | 284 | return UNICAST_DHCP; |
andrewboyson | 10:f0854784e960 | 285 | } |
andrewboyson | 10:f0854784e960 | 286 | else |
andrewboyson | 10:f0854784e960 | 287 | { |
andrewboyson | 10:f0854784e960 | 288 | if (DEBUG) LogTimeF("DHCP lease has expired\r\n"); |
andrewboyson | 10:f0854784e960 | 289 | DhcpLocalIp = 0; |
andrewboyson | 10:f0854784e960 | 290 | DhcpServer = 0; |
andrewboyson | 10:f0854784e960 | 291 | *pSize = sendRequest(pPacket, DHCPDISCOVER, 0, 0); //If outside T2 then start from scratch to do a full DHCP |
andrewboyson | 10:f0854784e960 | 292 | return BROADCAST; |
andrewboyson | 10:f0854784e960 | 293 | } |
andrewboyson | 10:f0854784e960 | 294 | |
andrewboyson | 10:f0854784e960 | 295 | } |