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/dns/dnshdr.c@187:122fc1996c86, 2021-01-18 (annotated)
- Committer:
- andrewboyson
- Date:
- Mon Jan 18 18:23:46 2021 +0000
- Revision:
- 187:122fc1996c86
- Parent:
- 172:9bc3c7b2cca1
Changed Ip4Address to Ip4Addr.; Moved Ip6AddrIsExternal from NdpNeedsToBeRouted.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
andrewboyson | 61:aad055f1b0d1 | 1 | #include <stdint.h> |
andrewboyson | 61:aad055f1b0d1 | 2 | #include <stdbool.h> |
andrewboyson | 61:aad055f1b0d1 | 3 | |
andrewboyson | 128:79052cb4a41c | 4 | #include "dns.h" |
andrewboyson | 128:79052cb4a41c | 5 | #include "net.h" |
andrewboyson | 128:79052cb4a41c | 6 | #include "log.h" |
andrewboyson | 128:79052cb4a41c | 7 | #include "net.h" |
andrewboyson | 128:79052cb4a41c | 8 | #include "eth.h" |
andrewboyson | 128:79052cb4a41c | 9 | #include "ip4addr.h" |
andrewboyson | 128:79052cb4a41c | 10 | #include "ip6addr.h" |
andrewboyson | 128:79052cb4a41c | 11 | #include "udp.h" |
andrewboyson | 128:79052cb4a41c | 12 | #include "dnsname.h" |
andrewboyson | 128:79052cb4a41c | 13 | #include "dnslabel.h" |
andrewboyson | 13:9cd54f7db57a | 14 | |
andrewboyson | 13:9cd54f7db57a | 15 | #define HEADER_LENGTH 12 |
andrewboyson | 13:9cd54f7db57a | 16 | |
andrewboyson | 13:9cd54f7db57a | 17 | uint16_t DnsHdrId; |
andrewboyson | 13:9cd54f7db57a | 18 | |
andrewboyson | 13:9cd54f7db57a | 19 | bool DnsHdrIsReply; |
andrewboyson | 13:9cd54f7db57a | 20 | bool DnsHdrIsAuthoritative; |
andrewboyson | 13:9cd54f7db57a | 21 | bool DnsHdrIsRecursiveQuery; |
andrewboyson | 13:9cd54f7db57a | 22 | |
andrewboyson | 13:9cd54f7db57a | 23 | uint16_t DnsHdrQdcount; |
andrewboyson | 13:9cd54f7db57a | 24 | uint16_t DnsHdrAncount; |
andrewboyson | 13:9cd54f7db57a | 25 | uint16_t DnsHdrNscount; |
andrewboyson | 13:9cd54f7db57a | 26 | uint16_t DnsHdrArcount; |
andrewboyson | 13:9cd54f7db57a | 27 | |
andrewboyson | 13:9cd54f7db57a | 28 | char* DnsHdrPacket; |
andrewboyson | 13:9cd54f7db57a | 29 | char* DnsHdrData; |
andrewboyson | 59:e0e556c8bd46 | 30 | int DnsHdrDataLength; |
andrewboyson | 13:9cd54f7db57a | 31 | |
andrewboyson | 59:e0e556c8bd46 | 32 | void DnsHdrSetup(void* pPacket, int lenPacket) |
andrewboyson | 13:9cd54f7db57a | 33 | { |
andrewboyson | 13:9cd54f7db57a | 34 | DnsHdrPacket = (char*)pPacket; |
andrewboyson | 136:8a65abb0dc63 | 35 | DnsHdrData = DnsHdrPacket + HEADER_LENGTH; |
andrewboyson | 136:8a65abb0dc63 | 36 | DnsHdrDataLength = lenPacket - HEADER_LENGTH; |
andrewboyson | 13:9cd54f7db57a | 37 | } |
andrewboyson | 13:9cd54f7db57a | 38 | |
andrewboyson | 13:9cd54f7db57a | 39 | void DnsHdrRead() |
andrewboyson | 13:9cd54f7db57a | 40 | { |
andrewboyson | 136:8a65abb0dc63 | 41 | NetInvert16(&DnsHdrId, DnsHdrPacket + 0); |
andrewboyson | 13:9cd54f7db57a | 42 | |
andrewboyson | 136:8a65abb0dc63 | 43 | uint8_t uflags = *(DnsHdrPacket + 2); |
andrewboyson | 13:9cd54f7db57a | 44 | DnsHdrIsReply = uflags & 0x80; |
andrewboyson | 13:9cd54f7db57a | 45 | DnsHdrIsAuthoritative = uflags & 0x04; |
andrewboyson | 33:714a0345e59b | 46 | DnsHdrIsRecursiveQuery = uflags & 0x01; |
andrewboyson | 13:9cd54f7db57a | 47 | |
andrewboyson | 136:8a65abb0dc63 | 48 | NetInvert16(&DnsHdrQdcount, DnsHdrPacket + 4); |
andrewboyson | 136:8a65abb0dc63 | 49 | NetInvert16(&DnsHdrAncount, DnsHdrPacket + 6); |
andrewboyson | 136:8a65abb0dc63 | 50 | NetInvert16(&DnsHdrNscount, DnsHdrPacket + 8); |
andrewboyson | 136:8a65abb0dc63 | 51 | NetInvert16(&DnsHdrArcount, DnsHdrPacket + 10); |
andrewboyson | 13:9cd54f7db57a | 52 | } |
andrewboyson | 13:9cd54f7db57a | 53 | void DnsHdrWrite() |
andrewboyson | 13:9cd54f7db57a | 54 | { |
andrewboyson | 136:8a65abb0dc63 | 55 | NetInvert16(DnsHdrPacket + 0, &DnsHdrId); |
andrewboyson | 13:9cd54f7db57a | 56 | |
andrewboyson | 13:9cd54f7db57a | 57 | uint8_t uflags = 0; |
andrewboyson | 13:9cd54f7db57a | 58 | uint8_t lflags = 0; |
andrewboyson | 13:9cd54f7db57a | 59 | if (DnsHdrIsReply) uflags |= 0x80; |
andrewboyson | 13:9cd54f7db57a | 60 | if (DnsHdrIsAuthoritative) uflags |= 0x04; |
andrewboyson | 13:9cd54f7db57a | 61 | if (DnsHdrIsRecursiveQuery) uflags |= 0x01; |
andrewboyson | 136:8a65abb0dc63 | 62 | *(DnsHdrPacket + 2) = uflags; |
andrewboyson | 136:8a65abb0dc63 | 63 | *(DnsHdrPacket + 3) = lflags; |
andrewboyson | 136:8a65abb0dc63 | 64 | |
andrewboyson | 136:8a65abb0dc63 | 65 | NetInvert16(DnsHdrPacket + 4, &DnsHdrQdcount); |
andrewboyson | 136:8a65abb0dc63 | 66 | NetInvert16(DnsHdrPacket + 6, &DnsHdrAncount); |
andrewboyson | 136:8a65abb0dc63 | 67 | NetInvert16(DnsHdrPacket + 8, &DnsHdrNscount); |
andrewboyson | 136:8a65abb0dc63 | 68 | NetInvert16(DnsHdrPacket + 10, &DnsHdrArcount); |
andrewboyson | 13:9cd54f7db57a | 69 | |
andrewboyson | 13:9cd54f7db57a | 70 | } |
andrewboyson | 58:d48c899e482f | 71 | static uint16_t decodeUint16(char* p) |
andrewboyson | 58:d48c899e482f | 72 | { |
andrewboyson | 58:d48c899e482f | 73 | uint16_t value = *p++; |
andrewboyson | 58:d48c899e482f | 74 | value <<= 8; value += *p++; |
andrewboyson | 58:d48c899e482f | 75 | return value; |
andrewboyson | 58:d48c899e482f | 76 | } |
andrewboyson | 58:d48c899e482f | 77 | static uint32_t decodeUint32(char* p) |
andrewboyson | 58:d48c899e482f | 78 | { |
andrewboyson | 58:d48c899e482f | 79 | uint32_t value = *p++; |
andrewboyson | 58:d48c899e482f | 80 | value <<= 8; value += *p++; |
andrewboyson | 58:d48c899e482f | 81 | value <<= 8; value += *p++; |
andrewboyson | 58:d48c899e482f | 82 | value <<= 8; value += *p++; |
andrewboyson | 58:d48c899e482f | 83 | return value; |
andrewboyson | 58:d48c899e482f | 84 | } |
andrewboyson | 58:d48c899e482f | 85 | static void logRecordA(int len, char* p) |
andrewboyson | 58:d48c899e482f | 86 | { |
andrewboyson | 187:122fc1996c86 | 87 | if (len == 4) Ip4AddrLog(*(uint32_t*)p); |
andrewboyson | 58:d48c899e482f | 88 | else LogF("expected 4 bytes but had %d", len); |
andrewboyson | 58:d48c899e482f | 89 | } |
andrewboyson | 58:d48c899e482f | 90 | static void logRecordAAAA(int len, char* p) |
andrewboyson | 58:d48c899e482f | 91 | { |
andrewboyson | 172:9bc3c7b2cca1 | 92 | if (len == 16) Ip6AddrLog(p); |
andrewboyson | 58:d48c899e482f | 93 | else LogF("expected 16 bytes but had %d", len); |
andrewboyson | 58:d48c899e482f | 94 | } |
andrewboyson | 58:d48c899e482f | 95 | static void logRecordPTR(int len, char* p) |
andrewboyson | 58:d48c899e482f | 96 | { |
andrewboyson | 58:d48c899e482f | 97 | if (len <= DNS_MAX_LABEL_LENGTH) DnsNameLogPtr(p); |
andrewboyson | 58:d48c899e482f | 98 | else LogF("length %d is greater than max DNS label length of %d\r\n", len, DNS_MAX_LABEL_LENGTH); |
andrewboyson | 58:d48c899e482f | 99 | } |
andrewboyson | 58:d48c899e482f | 100 | static void logRecordSRV(int len, char* p) |
andrewboyson | 58:d48c899e482f | 101 | { |
andrewboyson | 58:d48c899e482f | 102 | LogF("pri=%d " , decodeUint16(p)); p += 2; |
andrewboyson | 58:d48c899e482f | 103 | LogF("wei=%d " , decodeUint16(p)); p += 2; |
andrewboyson | 58:d48c899e482f | 104 | LogF("port=%d ", decodeUint16(p)); p += 2; |
andrewboyson | 58:d48c899e482f | 105 | DnsNameLogPtr(p); |
andrewboyson | 58:d48c899e482f | 106 | } |
andrewboyson | 58:d48c899e482f | 107 | static void logRecordTXT(int len, char* p) |
andrewboyson | 58:d48c899e482f | 108 | { |
andrewboyson | 58:d48c899e482f | 109 | char* pEnd = p + len; |
andrewboyson | 58:d48c899e482f | 110 | while (p < pEnd) |
andrewboyson | 58:d48c899e482f | 111 | { |
andrewboyson | 58:d48c899e482f | 112 | Log("\r\n "); |
andrewboyson | 58:d48c899e482f | 113 | int fieldLen = *p++; |
andrewboyson | 121:bc048b65a630 | 114 | for (int i = 0; i < fieldLen; i++) LogChar(*p++); |
andrewboyson | 58:d48c899e482f | 115 | } |
andrewboyson | 58:d48c899e482f | 116 | } |
andrewboyson | 37:793b39683406 | 117 | static void logContent() |
andrewboyson | 37:793b39683406 | 118 | { |
andrewboyson | 58:d48c899e482f | 119 | char* p = DnsHdrData; |
andrewboyson | 37:793b39683406 | 120 | |
andrewboyson | 37:793b39683406 | 121 | //Get the questions |
andrewboyson | 37:793b39683406 | 122 | for (int q = 0; q < DnsHdrQdcount; q++) |
andrewboyson | 37:793b39683406 | 123 | { |
andrewboyson | 59:e0e556c8bd46 | 124 | if (p >= DnsHdrData + DnsHdrDataLength) |
andrewboyson | 37:793b39683406 | 125 | { |
andrewboyson | 58:d48c899e482f | 126 | Log(" Questions have overrun the buffer\r\n"); |
andrewboyson | 37:793b39683406 | 127 | return; |
andrewboyson | 37:793b39683406 | 128 | } |
andrewboyson | 58:d48c899e482f | 129 | char* pEncodedName = p; |
andrewboyson | 37:793b39683406 | 130 | int nameLength = DnsNameLength(p); |
andrewboyson | 58:d48c899e482f | 131 | if (!nameLength) { LogTimeF(" Questions namelength is zero\r\n"); return; } |
andrewboyson | 37:793b39683406 | 132 | p += nameLength; //Skip past the name |
andrewboyson | 37:793b39683406 | 133 | p++ ; //skip the first byte of the type |
andrewboyson | 37:793b39683406 | 134 | char recordType = *p++; //read the record type |
andrewboyson | 37:793b39683406 | 135 | p += 2; //skip the class |
andrewboyson | 37:793b39683406 | 136 | |
andrewboyson | 47:73af5c0b0dc2 | 137 | LogF(" Query "); |
andrewboyson | 47:73af5c0b0dc2 | 138 | DnsRecordTypeLog(recordType); |
andrewboyson | 47:73af5c0b0dc2 | 139 | Log(" type record of "); |
andrewboyson | 58:d48c899e482f | 140 | DnsNameLogPtr(pEncodedName); |
andrewboyson | 47:73af5c0b0dc2 | 141 | Log("\r\n"); |
andrewboyson | 37:793b39683406 | 142 | } |
andrewboyson | 37:793b39683406 | 143 | |
andrewboyson | 37:793b39683406 | 144 | //Get the answers |
andrewboyson | 37:793b39683406 | 145 | for (int a = 0; a < DnsHdrAncount; a++) |
andrewboyson | 37:793b39683406 | 146 | { |
andrewboyson | 59:e0e556c8bd46 | 147 | if (p >= DnsHdrData + DnsHdrDataLength) { Log(" Answers have overrun the buffer\r\n"); return; } |
andrewboyson | 37:793b39683406 | 148 | |
andrewboyson | 58:d48c899e482f | 149 | char* pEncodedName = p; |
andrewboyson | 37:793b39683406 | 150 | int nameLength = DnsNameLength(p); |
andrewboyson | 43:bc028d5a6424 | 151 | if (!nameLength) { Log(" Answer name length is zero\r\n"); return; } |
andrewboyson | 37:793b39683406 | 152 | p += nameLength; //Skip past the name |
andrewboyson | 37:793b39683406 | 153 | |
andrewboyson | 37:793b39683406 | 154 | p++; //Skip the high byte of the record type |
andrewboyson | 37:793b39683406 | 155 | int recordType = *p++; //Record type |
andrewboyson | 37:793b39683406 | 156 | |
andrewboyson | 37:793b39683406 | 157 | p++; //Skip the high byte of the class type |
andrewboyson | 37:793b39683406 | 158 | int classType = *p++; //Class type |
andrewboyson | 37:793b39683406 | 159 | |
andrewboyson | 58:d48c899e482f | 160 | int ttl = decodeUint32(p); p += 4; //32bit TTL |
andrewboyson | 37:793b39683406 | 161 | |
andrewboyson | 58:d48c899e482f | 162 | int len = decodeUint16(p); p += 2; //16bit length |
andrewboyson | 37:793b39683406 | 163 | |
andrewboyson | 43:bc028d5a6424 | 164 | Log(" Answer "); |
andrewboyson | 47:73af5c0b0dc2 | 165 | DnsRecordTypeLog(recordType); |
andrewboyson | 43:bc028d5a6424 | 166 | Log(" type record of "); |
andrewboyson | 58:d48c899e482f | 167 | DnsNameLogPtr(pEncodedName); |
andrewboyson | 43:bc028d5a6424 | 168 | Log(" ==> "); |
andrewboyson | 37:793b39683406 | 169 | |
andrewboyson | 37:793b39683406 | 170 | switch (recordType) //Log the payload if its type is known |
andrewboyson | 37:793b39683406 | 171 | { |
andrewboyson | 58:d48c899e482f | 172 | case DNS_RECORD_A: logRecordA (len, p); break; |
andrewboyson | 58:d48c899e482f | 173 | case DNS_RECORD_AAAA: logRecordAAAA(len, p); break; |
andrewboyson | 58:d48c899e482f | 174 | case DNS_RECORD_PTR: logRecordPTR (len, p); break; |
andrewboyson | 58:d48c899e482f | 175 | case DNS_RECORD_SRV: logRecordSRV (len, p); break; |
andrewboyson | 58:d48c899e482f | 176 | case DNS_RECORD_TXT: logRecordTXT (len, p); break; |
andrewboyson | 58:d48c899e482f | 177 | default: LogF("%d characters", len); break; |
andrewboyson | 37:793b39683406 | 178 | } |
andrewboyson | 43:bc028d5a6424 | 179 | Log("\r\n"); |
andrewboyson | 37:793b39683406 | 180 | p += len; //Adjust the pointer to the next character after the payload |
andrewboyson | 37:793b39683406 | 181 | } |
andrewboyson | 37:793b39683406 | 182 | } |
andrewboyson | 37:793b39683406 | 183 | |
andrewboyson | 37:793b39683406 | 184 | void DnsHdrLog(int protocol) |
andrewboyson | 13:9cd54f7db57a | 185 | { |
andrewboyson | 43:bc028d5a6424 | 186 | if (NetTraceVerbose) |
andrewboyson | 15:6ca6778168b1 | 187 | { |
andrewboyson | 47:73af5c0b0dc2 | 188 | DnsProtocolLog(protocol); |
andrewboyson | 47:73af5c0b0dc2 | 189 | Log(" header\r\n"); |
andrewboyson | 43:bc028d5a6424 | 190 | LogF(" Ident %hd\r\n", DnsHdrId); |
andrewboyson | 43:bc028d5a6424 | 191 | if (DnsHdrIsReply) |
andrewboyson | 43:bc028d5a6424 | 192 | { |
andrewboyson | 43:bc028d5a6424 | 193 | if (DnsHdrIsAuthoritative) LogF(" Authoritative reply\r\n"); |
andrewboyson | 43:bc028d5a6424 | 194 | else LogF(" Non authoritative reply\r\n"); |
andrewboyson | 43:bc028d5a6424 | 195 | } |
andrewboyson | 43:bc028d5a6424 | 196 | else |
andrewboyson | 43:bc028d5a6424 | 197 | { |
andrewboyson | 43:bc028d5a6424 | 198 | if (DnsHdrIsRecursiveQuery) LogF(" Recursive query\r\n"); |
andrewboyson | 43:bc028d5a6424 | 199 | else LogF(" Non recursive query\r\n"); |
andrewboyson | 43:bc028d5a6424 | 200 | } |
andrewboyson | 43:bc028d5a6424 | 201 | LogF(" qd, an, ns, ar %hu, %hu, %hu, %hu\r\n", DnsHdrQdcount, DnsHdrAncount, DnsHdrNscount, DnsHdrArcount); |
andrewboyson | 15:6ca6778168b1 | 202 | } |
andrewboyson | 15:6ca6778168b1 | 203 | else |
andrewboyson | 15:6ca6778168b1 | 204 | { |
andrewboyson | 47:73af5c0b0dc2 | 205 | DnsProtocolLog(protocol); |
andrewboyson | 47:73af5c0b0dc2 | 206 | LogF(" header qd, an, ns, ar %hu, %hu, %hu, %hu\r\n", DnsHdrQdcount, DnsHdrAncount, DnsHdrNscount, DnsHdrArcount); |
andrewboyson | 15:6ca6778168b1 | 207 | } |
andrewboyson | 37:793b39683406 | 208 | logContent(); |
andrewboyson | 13:9cd54f7db57a | 209 | } |
andrewboyson | 13:9cd54f7db57a | 210 |