Andrew Boyson / net

A stack which works with or without an Mbed os library. Provides IPv4 or IPv6 with a full 1500 byte buffer.

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udp/dns/dns.cpp@47:73af5c0b0dc2, 2017-10-26 (annotated)

Committer:
andrewboyson
Date:
Thu Oct 26 14:50:24 2017 +0000
Revision:
47:73af5c0b0dc2
Parent:
43:bc028d5a6424
Child:
59:e0e556c8bd46
Replaced a number of temporary buffers with direct writes to the Log or HTTP.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 13:9cd54f7db57a 1 #include "dns.h"
andrewboyson 13:9cd54f7db57a 2 #include "dnshdr.h"
andrewboyson 13:9cd54f7db57a 3 #include "dnsquery.h"
andrewboyson 13:9cd54f7db57a 4 #include "dnsreply.h"
andrewboyson 13:9cd54f7db57a 5 #include "dnsserver.h"
andrewboyson 13:9cd54f7db57a 6 #include "io.h"
andrewboyson 32:679654f2d023 7 #include "log.h"
andrewboyson 32:679654f2d023 8 #include "dhcp.h"
andrewboyson 13:9cd54f7db57a 9
andrewboyson 47:73af5c0b0dc2 10 void DnsProtocolString(uint8_t protocol, int size, char* text)
andrewboyson 13:9cd54f7db57a 11 {
andrewboyson 13:9cd54f7db57a 12 switch (protocol)
andrewboyson 13:9cd54f7db57a 13 {
andrewboyson 13:9cd54f7db57a 14 case DNS_PROTOCOL_UDNS: strncpy (text, "DNS", size); break;
andrewboyson 13:9cd54f7db57a 15 case DNS_PROTOCOL_MDNS: strncpy (text, "MDNS", size); break;
andrewboyson 13:9cd54f7db57a 16 case DNS_PROTOCOL_LLMNR: strncpy (text, "LLMNR", size); break;
andrewboyson 13:9cd54f7db57a 17 default: snprintf(text, size, "%d", protocol); break;
andrewboyson 13:9cd54f7db57a 18 }
andrewboyson 13:9cd54f7db57a 19 }
andrewboyson 13:9cd54f7db57a 20
andrewboyson 47:73af5c0b0dc2 21 void DnsRecordTypeString(uint8_t recordtype, int size, char* text)
andrewboyson 13:9cd54f7db57a 22 {
andrewboyson 13:9cd54f7db57a 23 switch (recordtype)
andrewboyson 13:9cd54f7db57a 24 {
andrewboyson 13:9cd54f7db57a 25 case DNS_RECORD_A: strncpy (text, "A", size); break;
andrewboyson 13:9cd54f7db57a 26 case DNS_RECORD_AAAA: strncpy (text, "AAAA", size); break;
andrewboyson 13:9cd54f7db57a 27 case DNS_RECORD_PTR: strncpy (text, "PTR", size); break;
andrewboyson 15:6ca6778168b1 28 case DNS_RECORD_TXT: strncpy (text, "TXT", size); break;
andrewboyson 15:6ca6778168b1 29 case DNS_RECORD_SRV: strncpy (text, "SRV", size); break;
andrewboyson 13:9cd54f7db57a 30 default: snprintf(text, size, "%d", recordtype); break;
andrewboyson 13:9cd54f7db57a 31 }
andrewboyson 13:9cd54f7db57a 32 }
andrewboyson 47:73af5c0b0dc2 33 void DnsProtocolLog(uint8_t protocol)
andrewboyson 47:73af5c0b0dc2 34 {
andrewboyson 47:73af5c0b0dc2 35 switch (protocol)
andrewboyson 47:73af5c0b0dc2 36 {
andrewboyson 47:73af5c0b0dc2 37 case DNS_PROTOCOL_UDNS: Log ("DNS "); break;
andrewboyson 47:73af5c0b0dc2 38 case DNS_PROTOCOL_MDNS: Log ("MDNS "); break;
andrewboyson 47:73af5c0b0dc2 39 case DNS_PROTOCOL_LLMNR: Log ("LLMNR"); break;
andrewboyson 47:73af5c0b0dc2 40 default: LogF("%d", protocol); break;
andrewboyson 47:73af5c0b0dc2 41 }
andrewboyson 47:73af5c0b0dc2 42 }
andrewboyson 47:73af5c0b0dc2 43
andrewboyson 47:73af5c0b0dc2 44 void DnsRecordTypeLog(uint8_t recordtype)
andrewboyson 47:73af5c0b0dc2 45 {
andrewboyson 47:73af5c0b0dc2 46 switch (recordtype)
andrewboyson 47:73af5c0b0dc2 47 {
andrewboyson 47:73af5c0b0dc2 48 case DNS_RECORD_A: Log ("A" ); break;
andrewboyson 47:73af5c0b0dc2 49 case DNS_RECORD_AAAA: Log ("AAAA"); break;
andrewboyson 47:73af5c0b0dc2 50 case DNS_RECORD_PTR: Log ("PTR" ); break;
andrewboyson 47:73af5c0b0dc2 51 case DNS_RECORD_TXT: Log ("TXT" ); break;
andrewboyson 47:73af5c0b0dc2 52 case DNS_RECORD_SRV: Log ("SRV" ); break;
andrewboyson 47:73af5c0b0dc2 53 default: LogF("%d", recordtype); break;
andrewboyson 47:73af5c0b0dc2 54 }
andrewboyson 47:73af5c0b0dc2 55 }
andrewboyson 41:db727df5f98b 56 int DnsGetNextProtocol4(int protocol)
andrewboyson 32:679654f2d023 57 {
andrewboyson 32:679654f2d023 58 switch(protocol)
andrewboyson 32:679654f2d023 59 {
andrewboyson 32:679654f2d023 60 case DNS_PROTOCOL_NONE: return DNS_PROTOCOL_UDNS;
andrewboyson 32:679654f2d023 61 case DNS_PROTOCOL_UDNS: return DNS_PROTOCOL_MDNS;
andrewboyson 32:679654f2d023 62 case DNS_PROTOCOL_MDNS: return DNS_PROTOCOL_LLMNR;
andrewboyson 32:679654f2d023 63 case DNS_PROTOCOL_LLMNR: return DNS_PROTOCOL_NONE;
andrewboyson 32:679654f2d023 64 default: LogTimeF("DNS invalid protocol %d\r\n", protocol); return DNS_PROTOCOL_NONE;
andrewboyson 32:679654f2d023 65 }
andrewboyson 32:679654f2d023 66 }
andrewboyson 41:db727df5f98b 67 int DnsGetNextProtocol6(int protocol)
andrewboyson 41:db727df5f98b 68 {
andrewboyson 41:db727df5f98b 69 switch(protocol)
andrewboyson 41:db727df5f98b 70 {
andrewboyson 41:db727df5f98b 71 case DNS_PROTOCOL_NONE: return DNS_PROTOCOL_MDNS;
andrewboyson 41:db727df5f98b 72 case DNS_PROTOCOL_MDNS: return DNS_PROTOCOL_LLMNR;
andrewboyson 41:db727df5f98b 73 case DNS_PROTOCOL_LLMNR: return DNS_PROTOCOL_UDNS;
andrewboyson 41:db727df5f98b 74 case DNS_PROTOCOL_UDNS: return DNS_PROTOCOL_NONE;
andrewboyson 41:db727df5f98b 75 default: LogTimeF("DNS invalid protocol %d\r\n", protocol); return DNS_PROTOCOL_NONE;
andrewboyson 41:db727df5f98b 76 }
andrewboyson 41:db727df5f98b 77 }
andrewboyson 33:714a0345e59b 78 bool DnsHostNamesEquate(char* pA, char* pB)
andrewboyson 33:714a0345e59b 79 {
andrewboyson 33:714a0345e59b 80 while(true)
andrewboyson 33:714a0345e59b 81 {
andrewboyson 33:714a0345e59b 82 char a = *pA++;
andrewboyson 33:714a0345e59b 83 char b = *pB++;
andrewboyson 33:714a0345e59b 84 if (a >= 'A' && a <= 'Z') a |= 0x20; //Make lower case
andrewboyson 33:714a0345e59b 85 if (b >= 'A' && b <= 'Z') b |= 0x20; //Make lower case
andrewboyson 33:714a0345e59b 86 if (a != b) return false; //If different then stop and return the fact
andrewboyson 33:714a0345e59b 87 if (!a) break; //No need to check 'b' too as it will necessarily be equal to 'a' at this point.
andrewboyson 33:714a0345e59b 88 }
andrewboyson 33:714a0345e59b 89 return true; //If we get here the strings must equate.
andrewboyson 33:714a0345e59b 90 }
andrewboyson 33:714a0345e59b 91
andrewboyson 32:679654f2d023 92 int DnsMakeFullNameFromName(int protocol, char* p, int size, char* result)
andrewboyson 32:679654f2d023 93 {
andrewboyson 32:679654f2d023 94 int i = 0;
andrewboyson 32:679654f2d023 95 char c;
andrewboyson 32:679654f2d023 96
andrewboyson 32:679654f2d023 97 while (i < size - 1)
andrewboyson 32:679654f2d023 98 {
andrewboyson 32:679654f2d023 99 c = *p++;
andrewboyson 32:679654f2d023 100 if (!c) break;
andrewboyson 32:679654f2d023 101 *result++ = c;
andrewboyson 32:679654f2d023 102 i++;
andrewboyson 32:679654f2d023 103 }
andrewboyson 32:679654f2d023 104 if (protocol == DNS_PROTOCOL_MDNS)
andrewboyson 32:679654f2d023 105 {
andrewboyson 32:679654f2d023 106 p = ".local";
andrewboyson 32:679654f2d023 107 while (i < size - 1)
andrewboyson 32:679654f2d023 108 {
andrewboyson 32:679654f2d023 109 c = *p++;
andrewboyson 32:679654f2d023 110 if (!c) break;
andrewboyson 32:679654f2d023 111 *result++ = c;
andrewboyson 32:679654f2d023 112 i++;
andrewboyson 32:679654f2d023 113 }
andrewboyson 32:679654f2d023 114 }
andrewboyson 32:679654f2d023 115 if (protocol == DNS_PROTOCOL_UDNS && DhcpDomainName[0]) //Shouldn't do this in IPv6 as DHCP is IPv4 only
andrewboyson 32:679654f2d023 116 {
andrewboyson 32:679654f2d023 117 if (i < size - 1)
andrewboyson 32:679654f2d023 118 {
andrewboyson 32:679654f2d023 119 *result++ = '.';
andrewboyson 32:679654f2d023 120 i++;
andrewboyson 32:679654f2d023 121 }
andrewboyson 32:679654f2d023 122 p = DhcpDomainName;
andrewboyson 32:679654f2d023 123 while (i < size - 1)
andrewboyson 32:679654f2d023 124 {
andrewboyson 32:679654f2d023 125 c = *p++;
andrewboyson 32:679654f2d023 126 if (!c) break;
andrewboyson 32:679654f2d023 127 *result++ = c;
andrewboyson 32:679654f2d023 128 i++;
andrewboyson 32:679654f2d023 129 }
andrewboyson 32:679654f2d023 130 }
andrewboyson 32:679654f2d023 131 *result = 0; //Terminate the resulting string
andrewboyson 32:679654f2d023 132 return i;
andrewboyson 32:679654f2d023 133 }
andrewboyson 32:679654f2d023 134 int DnsStripNameFromFullName(int protocol, char* p, int size, char* result)
andrewboyson 32:679654f2d023 135 {
andrewboyson 32:679654f2d023 136 int i = 0;
andrewboyson 32:679654f2d023 137 char c;
andrewboyson 32:679654f2d023 138
andrewboyson 32:679654f2d023 139 while (i < size - 1)
andrewboyson 32:679654f2d023 140 {
andrewboyson 32:679654f2d023 141 c = *p++;
andrewboyson 32:679654f2d023 142 if (c == 0) break; //End of the fqdn so stop
andrewboyson 32:679654f2d023 143 if (c == '.')
andrewboyson 32:679654f2d023 144 {
andrewboyson 32:679654f2d023 145 if (protocol == DNS_PROTOCOL_UDNS)
andrewboyson 32:679654f2d023 146 {
andrewboyson 32:679654f2d023 147 if (strcmp(p, DhcpDomainName) == 0) break; //Strip the domain from a UDNS fqdn if, and only if, it matches the domain given in DHCP. IPv4 only.
andrewboyson 32:679654f2d023 148 }
andrewboyson 32:679654f2d023 149 else
andrewboyson 32:679654f2d023 150 {
andrewboyson 32:679654f2d023 151 break; //Strip the domain from an LLMNR (there shouldn't be one) or MDNS (it should always be '.local') fqdn
andrewboyson 32:679654f2d023 152 }
andrewboyson 32:679654f2d023 153 }
andrewboyson 32:679654f2d023 154 *result++ = c;
andrewboyson 32:679654f2d023 155 i++;
andrewboyson 32:679654f2d023 156 }
andrewboyson 32:679654f2d023 157 *result = 0; //Terminate the copied string
andrewboyson 32:679654f2d023 158 return i;
andrewboyson 32:679654f2d023 159 }
andrewboyson 13:9cd54f7db57a 160
andrewboyson 43:bc028d5a6424 161 void DnsMain()
andrewboyson 13:9cd54f7db57a 162 {
andrewboyson 43:bc028d5a6424 163 DnsQueryMain();
andrewboyson 13:9cd54f7db57a 164 }
andrewboyson 13:9cd54f7db57a 165
andrewboyson 37:793b39683406 166 int DnsHandlePacketReceived(void (*traceback)(void), int dnsProtocol, int* pSize, void* pPacket)
andrewboyson 13:9cd54f7db57a 167 {
andrewboyson 13:9cd54f7db57a 168 DnsHdrSetup(pPacket);
andrewboyson 13:9cd54f7db57a 169 DnsHdrRead();
andrewboyson 13:9cd54f7db57a 170 int action;
andrewboyson 13:9cd54f7db57a 171 if (DnsHdrIsReply)
andrewboyson 13:9cd54f7db57a 172 {
andrewboyson 37:793b39683406 173 action = DnsReplyHandle(traceback, dnsProtocol, pSize);
andrewboyson 13:9cd54f7db57a 174 }
andrewboyson 13:9cd54f7db57a 175 else
andrewboyson 13:9cd54f7db57a 176 {
andrewboyson 37:793b39683406 177 action = DnsServerHandleQuery(traceback, dnsProtocol, pSize);
andrewboyson 13:9cd54f7db57a 178 }
andrewboyson 13:9cd54f7db57a 179 return action;
andrewboyson 13:9cd54f7db57a 180 }
andrewboyson 13:9cd54f7db57a 181
andrewboyson 13:9cd54f7db57a 182 int DnsPollForPacketToSend(void* pPacket, int* pSize)
andrewboyson 13:9cd54f7db57a 183 {
andrewboyson 13:9cd54f7db57a 184 DnsHdrSetup(pPacket);
andrewboyson 13:9cd54f7db57a 185 return DnsQueryPoll(pSize);
andrewboyson 13:9cd54f7db57a 186 }