Andrew Boyson / net

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@37:793b39683406, 2017-10-04 (annotated)

Committer:
andrewboyson
Date:
Wed Oct 04 07:51:02 2017 +0000
Revision:
37:793b39683406
Parent:
36:900e24b27bfb
Child:
43:bc028d5a6424
Added trace back and trace forward to log messages

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 37:793b39683406 1 #include "mbed.h"
andrewboyson 37:793b39683406 2 #include "log.h"
andrewboyson 37:793b39683406 3 #include "net.h"
andrewboyson 37:793b39683406 4 #include "action.h"
andrewboyson 37:793b39683406 5 #include "eth.h"
andrewboyson 37:793b39683406 6 #include "ip4.h"
andrewboyson 37:793b39683406 7 #include "mac.h"
andrewboyson 37:793b39683406 8 #include "udp.h"
andrewboyson 10:f0854784e960 9
andrewboyson 37:793b39683406 10 bool DhcpTrace = false;
andrewboyson 10:f0854784e960 11
andrewboyson 10:f0854784e960 12 #define REQUEST 1
andrewboyson 10:f0854784e960 13 #define REPLY 2
andrewboyson 10:f0854784e960 14
andrewboyson 10:f0854784e960 15 #define DHCPDISCOVER 1
andrewboyson 10:f0854784e960 16 #define DHCPOFFER 2
andrewboyson 10:f0854784e960 17 #define DHCPREQUEST 3
andrewboyson 10:f0854784e960 18 #define DHCPDECLINE 4
andrewboyson 10:f0854784e960 19 #define DHCPACK 5
andrewboyson 10:f0854784e960 20 #define DHCPNAK 6
andrewboyson 10:f0854784e960 21 #define DHCPRELEASE 7
andrewboyson 10:f0854784e960 22 #define DHCPINFORM 8
andrewboyson 10:f0854784e960 23
andrewboyson 10:f0854784e960 24 #define ID 75648
andrewboyson 10:f0854784e960 25 #define COOKIE 0x63825363
andrewboyson 10:f0854784e960 26 #define HEADER_LENGTH 240
andrewboyson 10:f0854784e960 27
andrewboyson 10:f0854784e960 28 __packed struct header
andrewboyson 10:f0854784e960 29 {
andrewboyson 10:f0854784e960 30 uint8_t op;
andrewboyson 10:f0854784e960 31 uint8_t htype;
andrewboyson 10:f0854784e960 32 uint8_t hlen;
andrewboyson 10:f0854784e960 33 uint8_t hops;
andrewboyson 10:f0854784e960 34
andrewboyson 10:f0854784e960 35 uint32_t xid;
andrewboyson 10:f0854784e960 36
andrewboyson 10:f0854784e960 37 uint16_t secs;
andrewboyson 10:f0854784e960 38 uint16_t flags;
andrewboyson 10:f0854784e960 39
andrewboyson 10:f0854784e960 40 uint32_t ciaddr;
andrewboyson 10:f0854784e960 41 uint32_t yiaddr;
andrewboyson 10:f0854784e960 42 uint32_t siaddr;
andrewboyson 10:f0854784e960 43 uint32_t giaddr;
andrewboyson 10:f0854784e960 44
andrewboyson 10:f0854784e960 45 uint8_t chaddr[16];
andrewboyson 10:f0854784e960 46
andrewboyson 10:f0854784e960 47 char legacy[192];
andrewboyson 10:f0854784e960 48
andrewboyson 10:f0854784e960 49 uint32_t cookie;
andrewboyson 10:f0854784e960 50 };
andrewboyson 10:f0854784e960 51
andrewboyson 10:f0854784e960 52 #define REPEAT_DELAY_TIME 60
andrewboyson 10:f0854784e960 53 static uint32_t delayTime = 10000000; //Reset whenever a message is sent and blocks another send until count exceeds REPEAT_DELAY_TIME
andrewboyson 29:39277bf2003d 54 uint32_t DhcpElapsedTime = 0; //Reset whenever an IP address request has been acknowledged
andrewboyson 10:f0854784e960 55 void DhcpTick()
andrewboyson 10:f0854784e960 56 {
andrewboyson 29:39277bf2003d 57 DhcpElapsedTime++;
andrewboyson 29:39277bf2003d 58 delayTime++;
andrewboyson 10:f0854784e960 59 }
andrewboyson 10:f0854784e960 60
andrewboyson 10:f0854784e960 61 static uint8_t dhcpMessageType = 0;
andrewboyson 10:f0854784e960 62 uint32_t DhcpLeaseTime = 0;
andrewboyson 10:f0854784e960 63 uint32_t DhcpServer = 0;
andrewboyson 10:f0854784e960 64 uint32_t DhcpRouter = 0;
andrewboyson 10:f0854784e960 65 uint32_t DhcpSubnetMask = 0;
andrewboyson 10:f0854784e960 66 uint32_t DhcpNtp = 0;
andrewboyson 10:f0854784e960 67 uint32_t DhcpRenewalT1 = 0;
andrewboyson 10:f0854784e960 68 uint32_t DhcpRenewalT2 = 0;
andrewboyson 10:f0854784e960 69 uint32_t DhcpBroadcastIp = 0;
andrewboyson 10:f0854784e960 70 uint32_t DhcpLocalIp = 0;
andrewboyson 10:f0854784e960 71 uint32_t DhcpDnsServer = 0;
andrewboyson 10:f0854784e960 72 char DhcpDomainName[20];
andrewboyson 10:f0854784e960 73 char DhcpHostName[20];
andrewboyson 10:f0854784e960 74 static uint32_t readOption32(char** pp)
andrewboyson 10:f0854784e960 75 {
andrewboyson 10:f0854784e960 76 uint32_t value = 0;
andrewboyson 10:f0854784e960 77 char* p = *pp;
andrewboyson 10:f0854784e960 78 int len = *++p;
andrewboyson 10:f0854784e960 79 if (len >= 4)
andrewboyson 10:f0854784e960 80 {
andrewboyson 10:f0854784e960 81 value = *++p << 24;
andrewboyson 10:f0854784e960 82 value |= *++p << 16;
andrewboyson 10:f0854784e960 83 value |= *++p << 8;
andrewboyson 10:f0854784e960 84 value |= *++p << 0;
andrewboyson 10:f0854784e960 85 }
andrewboyson 10:f0854784e960 86 *pp += len + 1;
andrewboyson 10:f0854784e960 87 return value;
andrewboyson 10:f0854784e960 88 }
andrewboyson 10:f0854784e960 89 static uint32_t readIp(char** pp)
andrewboyson 10:f0854784e960 90 {
andrewboyson 10:f0854784e960 91 uint32_t value = 0;
andrewboyson 10:f0854784e960 92 char* p = *pp;
andrewboyson 10:f0854784e960 93 int len = *++p;
andrewboyson 10:f0854784e960 94 if (len >= 4)
andrewboyson 10:f0854784e960 95 {
andrewboyson 10:f0854784e960 96 value = *++p << 0;
andrewboyson 10:f0854784e960 97 value |= *++p << 8;
andrewboyson 10:f0854784e960 98 value |= *++p << 16;
andrewboyson 10:f0854784e960 99 value |= *++p << 24;
andrewboyson 10:f0854784e960 100 }
andrewboyson 10:f0854784e960 101 *pp += len + 1;
andrewboyson 10:f0854784e960 102 return value;
andrewboyson 10:f0854784e960 103 }
andrewboyson 10:f0854784e960 104 static void readString(char** pp, char* pText)
andrewboyson 10:f0854784e960 105 {
andrewboyson 10:f0854784e960 106 char* p = *pp;
andrewboyson 10:f0854784e960 107 int len = *++p;
andrewboyson 10:f0854784e960 108 for (int i = 0; i < len; i++) pText[i] = *++p;
andrewboyson 10:f0854784e960 109 *pp += len + 1;
andrewboyson 10:f0854784e960 110 }
andrewboyson 10:f0854784e960 111 static void readOptions(int size, char * pOptions)
andrewboyson 10:f0854784e960 112 {
andrewboyson 10:f0854784e960 113 int len = 0;
andrewboyson 10:f0854784e960 114 char* p = pOptions;
andrewboyson 10:f0854784e960 115 char* pE = pOptions + size;
andrewboyson 10:f0854784e960 116 while( p < pE)
andrewboyson 10:f0854784e960 117 {
andrewboyson 10:f0854784e960 118 switch (*p)
andrewboyson 10:f0854784e960 119 {
andrewboyson 10:f0854784e960 120 case 0: break; //NOP
andrewboyson 10:f0854784e960 121 case 255: return; //End of options
andrewboyson 10:f0854784e960 122 case 1: DhcpSubnetMask = readIp(&p); break; //Subnet Mask
andrewboyson 10:f0854784e960 123 case 3: DhcpRouter = readIp(&p); break; //Router
andrewboyson 10:f0854784e960 124 case 6: DhcpDnsServer = readIp(&p); break; //DNS server
andrewboyson 10:f0854784e960 125 case 12: readString(&p, DhcpHostName); break; //Host name
andrewboyson 10:f0854784e960 126 case 15: readString(&p, DhcpDomainName); break; //Domain name
andrewboyson 10:f0854784e960 127 case 19: len = *++p; p+= len; break; //IP forwarding yes/no
andrewboyson 10:f0854784e960 128 case 28: DhcpBroadcastIp = readIp(&p); break; //Broadcast IP
andrewboyson 10:f0854784e960 129 case 42: DhcpNtp = readIp(&p); break; //NTP
andrewboyson 10:f0854784e960 130 case 44: len = *++p; p+= len; break; //NetBIOS name server
andrewboyson 10:f0854784e960 131 case 45: len = *++p; p+= len; break; //NetBIOS datagram server
andrewboyson 10:f0854784e960 132 case 46: len = *++p; p+= len; break; //NetBIOS node type
andrewboyson 10:f0854784e960 133 case 47: len = *++p; p+= len; break; //NetBIOS scope
andrewboyson 10:f0854784e960 134 case 53: len = *++p; dhcpMessageType = *++p; break; //DHCP message type
andrewboyson 10:f0854784e960 135 case 51: DhcpLeaseTime = readOption32(&p); break; //Address lease time
andrewboyson 10:f0854784e960 136 case 54: DhcpServer = readIp(&p); break; //DHCP server
andrewboyson 10:f0854784e960 137 case 58: DhcpRenewalT1 = readOption32(&p); break; //T1
andrewboyson 10:f0854784e960 138 case 59: DhcpRenewalT2 = readOption32(&p); break; //T2
andrewboyson 10:f0854784e960 139 default:
andrewboyson 37:793b39683406 140 if (DhcpTrace) LogTimeF("Ignoring option %d\r\n", *p);
andrewboyson 10:f0854784e960 141 len = *++p;
andrewboyson 10:f0854784e960 142 p += len;
andrewboyson 10:f0854784e960 143 return;
andrewboyson 10:f0854784e960 144 }
andrewboyson 10:f0854784e960 145 p++;
andrewboyson 10:f0854784e960 146 }
andrewboyson 10:f0854784e960 147 }
andrewboyson 10:f0854784e960 148 static void writeIp(uint8_t code, uint32_t value, char** pp)
andrewboyson 10:f0854784e960 149 {
andrewboyson 10:f0854784e960 150 if (!value) return;
andrewboyson 10:f0854784e960 151
andrewboyson 10:f0854784e960 152 char* p = *pp;
andrewboyson 10:f0854784e960 153
andrewboyson 10:f0854784e960 154 *p++ = code;
andrewboyson 10:f0854784e960 155 *p++ = 4;
andrewboyson 10:f0854784e960 156 *p++ = (value & 0x000000FF) >> 0;
andrewboyson 10:f0854784e960 157 *p++ = (value & 0x0000FF00) >> 8;
andrewboyson 10:f0854784e960 158 *p++ = (value & 0x00FF0000) >> 16;
andrewboyson 10:f0854784e960 159 *p++ = (value & 0xFF000000) >> 24;
andrewboyson 10:f0854784e960 160
andrewboyson 10:f0854784e960 161 *pp += 6;
andrewboyson 10:f0854784e960 162 }
andrewboyson 10:f0854784e960 163 int sendRequest(void* pPacket, uint8_t code, uint32_t srvIp, uint32_t reqIp)
andrewboyson 10:f0854784e960 164 {
andrewboyson 10:f0854784e960 165
andrewboyson 10:f0854784e960 166 switch (code)
andrewboyson 10:f0854784e960 167 {
andrewboyson 10:f0854784e960 168 case DHCPDISCOVER:
andrewboyson 37:793b39683406 169 if (DhcpTrace) LogTimeF("DHCP -> discover");
andrewboyson 10:f0854784e960 170 break;
andrewboyson 10:f0854784e960 171 case DHCPREQUEST:
andrewboyson 37:793b39683406 172 if (DhcpTrace) LogTimeF("DHCP -> request");
andrewboyson 10:f0854784e960 173 break;
andrewboyson 10:f0854784e960 174 default:
andrewboyson 10:f0854784e960 175 LogTimeF("DHCP -> unknown message %d", code);
andrewboyson 10:f0854784e960 176 break;
andrewboyson 10:f0854784e960 177 }
andrewboyson 37:793b39683406 178 if (DhcpTrace)
andrewboyson 10:f0854784e960 179 {
andrewboyson 10:f0854784e960 180 char text[20];
andrewboyson 14:e75a59c1123d 181 Ip4AddressToString(srvIp, sizeof(text), text);
andrewboyson 10:f0854784e960 182 LogF(" server=%s", text);
andrewboyson 14:e75a59c1123d 183 Ip4AddressToString(reqIp, sizeof(text), text);
andrewboyson 10:f0854784e960 184 LogF(" request=%s", text);
andrewboyson 14:e75a59c1123d 185 Ip4AddressToString(DhcpLocalIp, sizeof(text), text);
andrewboyson 10:f0854784e960 186 LogF(" local=%s\r\n", text);
andrewboyson 10:f0854784e960 187 }
andrewboyson 10:f0854784e960 188
andrewboyson 10:f0854784e960 189 bool broadcast = DhcpLocalIp == 0;
andrewboyson 10:f0854784e960 190 uint16_t flags = 0;
andrewboyson 10:f0854784e960 191 if (broadcast) flags |= 0x0080; //0x8000 on the net == 0x0080 in little endian
andrewboyson 10:f0854784e960 192 struct header* pHeader = (header*)pPacket;
andrewboyson 10:f0854784e960 193 pHeader->op = REQUEST;
andrewboyson 10:f0854784e960 194 pHeader->htype = ETHERNET;
andrewboyson 10:f0854784e960 195 pHeader->hlen = 6;
andrewboyson 10:f0854784e960 196 pHeader->hops = 0;
andrewboyson 10:f0854784e960 197 pHeader->xid = ID; //Randomly chosed transaction id used to associate messages to responses
andrewboyson 10:f0854784e960 198 pHeader->secs = 0; //Seconds since started to boot
andrewboyson 10:f0854784e960 199 pHeader->flags = flags; //Broadcast (1) Unicast (0)
andrewboyson 10:f0854784e960 200 pHeader->ciaddr = DhcpLocalIp; //'Client' address set by client or 0 if don't know address
andrewboyson 10:f0854784e960 201 pHeader->yiaddr = 0; //'Your' address returned by server
andrewboyson 10:f0854784e960 202 pHeader->siaddr = srvIp; //'Server' address to use if required
andrewboyson 10:f0854784e960 203 pHeader->giaddr = 0; //'Gateway' address
andrewboyson 13:9cd54f7db57a 204 memcpy(pHeader->chaddr, MacLocal, 6); //'Client hardware' address. 6 bytes for ethernet
andrewboyson 10:f0854784e960 205 memset(pHeader->legacy, 0, 192); //BootP legacy fill with zeros
andrewboyson 10:f0854784e960 206 pHeader->cookie = NetToHost32(COOKIE); //Magic cookie
andrewboyson 10:f0854784e960 207
andrewboyson 10:f0854784e960 208 char* pOptions = (char*)pPacket + HEADER_LENGTH;
andrewboyson 10:f0854784e960 209 char* p = pOptions;
andrewboyson 10:f0854784e960 210 *p++ = 53; //Message code
andrewboyson 10:f0854784e960 211 *p++ = 1;
andrewboyson 10:f0854784e960 212 *p++ = code;
andrewboyson 10:f0854784e960 213
andrewboyson 10:f0854784e960 214 writeIp(50, reqIp, &p); //Requested IP
andrewboyson 10:f0854784e960 215 writeIp(54, srvIp, &p); //Server ip
andrewboyson 10:f0854784e960 216
andrewboyson 10:f0854784e960 217 *p++ = 255; //End of options
andrewboyson 10:f0854784e960 218
andrewboyson 10:f0854784e960 219 delayTime = 0;
andrewboyson 10:f0854784e960 220 return HEADER_LENGTH + p - pOptions;
andrewboyson 10:f0854784e960 221 }
andrewboyson 37:793b39683406 222 int DhcpHandleResponse(void (*traceback)(void), int* pSize, void* pPacket)
andrewboyson 10:f0854784e960 223 {
andrewboyson 10:f0854784e960 224 struct header* pHeader = (header*)pPacket;
andrewboyson 10:f0854784e960 225
andrewboyson 10:f0854784e960 226 uint8_t op = pHeader->op;
andrewboyson 10:f0854784e960 227 uint8_t htype = pHeader->htype;
andrewboyson 10:f0854784e960 228 uint8_t hlen = pHeader->hlen;
andrewboyson 10:f0854784e960 229
andrewboyson 36:900e24b27bfb 230 uint32_t xid = pHeader->xid; //Randomly chosen transaction id used to associate messages to responses
andrewboyson 10:f0854784e960 231
andrewboyson 10:f0854784e960 232 uint16_t secs = NetToHost16(pHeader->secs);
andrewboyson 10:f0854784e960 233 uint16_t flags = NetToHost16(pHeader->flags);
andrewboyson 10:f0854784e960 234
andrewboyson 10:f0854784e960 235 uint32_t yiaddr = pHeader->yiaddr;
andrewboyson 10:f0854784e960 236 uint32_t siaddr = pHeader->siaddr;
andrewboyson 10:f0854784e960 237 uint32_t cookie = NetToHost32(pHeader->cookie);
andrewboyson 10:f0854784e960 238
andrewboyson 28:edc17eeb4142 239 if (op != REPLY) return DO_NOTHING;
andrewboyson 28:edc17eeb4142 240 if (htype != ETHERNET) return DO_NOTHING;
andrewboyson 28:edc17eeb4142 241 if (hlen != 6) return DO_NOTHING;
andrewboyson 28:edc17eeb4142 242 if (memcmp(pHeader->chaddr, MacLocal, 6)) return DO_NOTHING;
andrewboyson 28:edc17eeb4142 243 if (xid != ID) return DO_NOTHING;
andrewboyson 28:edc17eeb4142 244 if (cookie != COOKIE) return DO_NOTHING;
andrewboyson 10:f0854784e960 245
andrewboyson 10:f0854784e960 246 char* pOptions = (char*)pPacket + HEADER_LENGTH;
andrewboyson 10:f0854784e960 247 readOptions(*pSize - HEADER_LENGTH, pOptions);
andrewboyson 10:f0854784e960 248
andrewboyson 10:f0854784e960 249 char text[30];
andrewboyson 10:f0854784e960 250 switch (dhcpMessageType)
andrewboyson 10:f0854784e960 251 {
andrewboyson 10:f0854784e960 252 case DHCPOFFER:
andrewboyson 14:e75a59c1123d 253 Ip4AddressToString(yiaddr, sizeof(text), text);
andrewboyson 37:793b39683406 254 if (DhcpTrace) LogTimeF("DHCP <- offer ip %s\r\n", text);
andrewboyson 10:f0854784e960 255 *pSize =sendRequest(pPacket, DHCPREQUEST, siaddr, yiaddr);
andrewboyson 10:f0854784e960 256 return BROADCAST;
andrewboyson 10:f0854784e960 257 case DHCPACK:
andrewboyson 14:e75a59c1123d 258 Ip4AddressToString(yiaddr, sizeof(text), text);
andrewboyson 37:793b39683406 259 if (DhcpTrace) LogTimeF("DHCP <- ack ip %s\r\n", text);
andrewboyson 10:f0854784e960 260 DhcpLocalIp = yiaddr;
andrewboyson 29:39277bf2003d 261 DhcpElapsedTime = 0;
andrewboyson 10:f0854784e960 262 break;
andrewboyson 10:f0854784e960 263 case DHCPNAK:
andrewboyson 14:e75a59c1123d 264 Ip4AddressToString(yiaddr, sizeof(text), text);
andrewboyson 37:793b39683406 265 if (DhcpTrace) LogTimeF("DHCP <- nack ip %s\r\n", text);
andrewboyson 10:f0854784e960 266 break;
andrewboyson 10:f0854784e960 267 default:
andrewboyson 10:f0854784e960 268 LogTimeF("DHCP <- unknown message %d\r\n", dhcpMessageType);
andrewboyson 10:f0854784e960 269 break;
andrewboyson 10:f0854784e960 270 }
andrewboyson 10:f0854784e960 271 return DO_NOTHING;
andrewboyson 10:f0854784e960 272 }
andrewboyson 10:f0854784e960 273
andrewboyson 10:f0854784e960 274 int DhcpPollForRequestToSend(void* pPacket, int* pSize)
andrewboyson 10:f0854784e960 275 {
andrewboyson 10:f0854784e960 276 if (delayTime < REPEAT_DELAY_TIME) return DO_NOTHING; //Don't retry within the delay time
andrewboyson 10:f0854784e960 277
andrewboyson 29:39277bf2003d 278 if (DhcpLocalIp && DhcpElapsedTime < (DhcpLeaseTime >> 1)) return 0; //Do nothing if have address and within T1
andrewboyson 10:f0854784e960 279
andrewboyson 10:f0854784e960 280 *pSize = 0;
andrewboyson 37:793b39683406 281 int dest = DO_NOTHING;
andrewboyson 29:39277bf2003d 282 if (DhcpLocalIp && DhcpElapsedTime < DhcpLeaseTime)
andrewboyson 10:f0854784e960 283 {
andrewboyson 10:f0854784e960 284 *pSize = sendRequest(pPacket, DHCPREQUEST, DhcpServer, DhcpLocalIp); //if within T2 then send request to the server - not broadcast
andrewboyson 37:793b39683406 285 dest = UNICAST_DHCP;
andrewboyson 10:f0854784e960 286 }
andrewboyson 10:f0854784e960 287 else
andrewboyson 10:f0854784e960 288 {
andrewboyson 37:793b39683406 289 if (DhcpTrace) LogTimeF("DHCP lease has expired\r\n");
andrewboyson 10:f0854784e960 290 DhcpLocalIp = 0;
andrewboyson 10:f0854784e960 291 DhcpServer = 0;
andrewboyson 10:f0854784e960 292 *pSize = sendRequest(pPacket, DHCPDISCOVER, 0, 0); //If outside T2 then start from scratch to do a full DHCP
andrewboyson 37:793b39683406 293 dest = BROADCAST;
andrewboyson 10:f0854784e960 294 }
andrewboyson 37:793b39683406 295 return ActionMakeFromDestAndTrace(dest, DhcpTrace);
andrewboyson 10:f0854784e960 296 }