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@32:679654f2d023, 2017-08-17 (annotated)

Committer:
andrewboyson
Date:
Thu Aug 17 14:21:02 2017 +0000
Revision:
32:679654f2d023
Parent:
15:6ca6778168b1
Child:
33:714a0345e59b
Corrected issues with .local in llmnr and mdns

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 13:9cd54f7db57a 10 void DnsProtocolToString(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 13:9cd54f7db57a 21 void DnsRecordTypeToString(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 32:679654f2d023 33 int DnsGetNextProtocol(int protocol)
andrewboyson 32:679654f2d023 34 {
andrewboyson 32:679654f2d023 35 switch(protocol)
andrewboyson 32:679654f2d023 36 {
andrewboyson 32:679654f2d023 37 case DNS_PROTOCOL_NONE: return DNS_PROTOCOL_UDNS;
andrewboyson 32:679654f2d023 38 case DNS_PROTOCOL_UDNS: return DNS_PROTOCOL_MDNS;
andrewboyson 32:679654f2d023 39 case DNS_PROTOCOL_MDNS: return DNS_PROTOCOL_LLMNR;
andrewboyson 32:679654f2d023 40 case DNS_PROTOCOL_LLMNR: return DNS_PROTOCOL_NONE;
andrewboyson 32:679654f2d023 41 default: LogTimeF("DNS invalid protocol %d\r\n", protocol); return DNS_PROTOCOL_NONE;
andrewboyson 32:679654f2d023 42 }
andrewboyson 32:679654f2d023 43 }
andrewboyson 32:679654f2d023 44 int DnsMakeFullNameFromName(int protocol, char* p, int size, char* result)
andrewboyson 32:679654f2d023 45 {
andrewboyson 32:679654f2d023 46 int i = 0;
andrewboyson 32:679654f2d023 47 char c;
andrewboyson 32:679654f2d023 48
andrewboyson 32:679654f2d023 49 while (i < size - 1)
andrewboyson 32:679654f2d023 50 {
andrewboyson 32:679654f2d023 51 c = *p++;
andrewboyson 32:679654f2d023 52 if (!c) break;
andrewboyson 32:679654f2d023 53 *result++ = c;
andrewboyson 32:679654f2d023 54 i++;
andrewboyson 32:679654f2d023 55 }
andrewboyson 32:679654f2d023 56 if (protocol == DNS_PROTOCOL_MDNS)
andrewboyson 32:679654f2d023 57 {
andrewboyson 32:679654f2d023 58 p = ".local";
andrewboyson 32:679654f2d023 59 while (i < size - 1)
andrewboyson 32:679654f2d023 60 {
andrewboyson 32:679654f2d023 61 c = *p++;
andrewboyson 32:679654f2d023 62 if (!c) break;
andrewboyson 32:679654f2d023 63 *result++ = c;
andrewboyson 32:679654f2d023 64 i++;
andrewboyson 32:679654f2d023 65 }
andrewboyson 32:679654f2d023 66 }
andrewboyson 32:679654f2d023 67 if (protocol == DNS_PROTOCOL_UDNS && DhcpDomainName[0]) //Shouldn't do this in IPv6 as DHCP is IPv4 only
andrewboyson 32:679654f2d023 68 {
andrewboyson 32:679654f2d023 69 if (i < size - 1)
andrewboyson 32:679654f2d023 70 {
andrewboyson 32:679654f2d023 71 *result++ = '.';
andrewboyson 32:679654f2d023 72 i++;
andrewboyson 32:679654f2d023 73 }
andrewboyson 32:679654f2d023 74 p = DhcpDomainName;
andrewboyson 32:679654f2d023 75 while (i < size - 1)
andrewboyson 32:679654f2d023 76 {
andrewboyson 32:679654f2d023 77 c = *p++;
andrewboyson 32:679654f2d023 78 if (!c) break;
andrewboyson 32:679654f2d023 79 *result++ = c;
andrewboyson 32:679654f2d023 80 i++;
andrewboyson 32:679654f2d023 81 }
andrewboyson 32:679654f2d023 82 }
andrewboyson 32:679654f2d023 83 *result = 0; //Terminate the resulting string
andrewboyson 32:679654f2d023 84 return i;
andrewboyson 32:679654f2d023 85 }
andrewboyson 32:679654f2d023 86 int DnsStripNameFromFullName(int protocol, char* p, int size, char* result)
andrewboyson 32:679654f2d023 87 {
andrewboyson 32:679654f2d023 88 int i = 0;
andrewboyson 32:679654f2d023 89 char c;
andrewboyson 32:679654f2d023 90
andrewboyson 32:679654f2d023 91 while (i < size - 1)
andrewboyson 32:679654f2d023 92 {
andrewboyson 32:679654f2d023 93 c = *p++;
andrewboyson 32:679654f2d023 94 if (c >= 'A' && c <= 'Z') c |= 0x20; //Make lower case
andrewboyson 32:679654f2d023 95 if (c == 0) break; //End of the fqdn so stop
andrewboyson 32:679654f2d023 96 if (c == '.')
andrewboyson 32:679654f2d023 97 {
andrewboyson 32:679654f2d023 98 if (protocol == DNS_PROTOCOL_UDNS)
andrewboyson 32:679654f2d023 99 {
andrewboyson 32:679654f2d023 100 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 101 }
andrewboyson 32:679654f2d023 102 else
andrewboyson 32:679654f2d023 103 {
andrewboyson 32:679654f2d023 104 break; //Strip the domain from an LLMNR (there shouldn't be one) or MDNS (it should always be '.local') fqdn
andrewboyson 32:679654f2d023 105 }
andrewboyson 32:679654f2d023 106 }
andrewboyson 32:679654f2d023 107 *result++ = c;
andrewboyson 32:679654f2d023 108 i++;
andrewboyson 32:679654f2d023 109 }
andrewboyson 32:679654f2d023 110 *result = 0; //Terminate the copied string
andrewboyson 32:679654f2d023 111 return i;
andrewboyson 32:679654f2d023 112 }
andrewboyson 13:9cd54f7db57a 113
andrewboyson 13:9cd54f7db57a 114 void DnsTick()
andrewboyson 13:9cd54f7db57a 115 {
andrewboyson 13:9cd54f7db57a 116 DnsQueryTick();
andrewboyson 13:9cd54f7db57a 117 }
andrewboyson 13:9cd54f7db57a 118
andrewboyson 13:9cd54f7db57a 119 int DnsHandlePacketReceived(int dnsProtocol, int* pSize, void* pPacket)
andrewboyson 13:9cd54f7db57a 120 {
andrewboyson 13:9cd54f7db57a 121 DnsHdrSetup(pPacket);
andrewboyson 13:9cd54f7db57a 122 DnsHdrRead();
andrewboyson 13:9cd54f7db57a 123 int action;
andrewboyson 13:9cd54f7db57a 124 if (DnsHdrIsReply)
andrewboyson 13:9cd54f7db57a 125 {
andrewboyson 13:9cd54f7db57a 126 action = DnsReplyHandle(dnsProtocol, pSize);
andrewboyson 13:9cd54f7db57a 127 }
andrewboyson 13:9cd54f7db57a 128 else
andrewboyson 13:9cd54f7db57a 129 {
andrewboyson 13:9cd54f7db57a 130 action = DnsServerHandleQuery(dnsProtocol, pSize);
andrewboyson 13:9cd54f7db57a 131 }
andrewboyson 13:9cd54f7db57a 132 return action;
andrewboyson 13:9cd54f7db57a 133 }
andrewboyson 13:9cd54f7db57a 134
andrewboyson 13:9cd54f7db57a 135 int DnsPollForPacketToSend(void* pPacket, int* pSize)
andrewboyson 13:9cd54f7db57a 136 {
andrewboyson 13:9cd54f7db57a 137 DnsHdrSetup(pPacket);
andrewboyson 13:9cd54f7db57a 138 return DnsQueryPoll(pSize);
andrewboyson 13:9cd54f7db57a 139 }