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/dnsquery.cpp@36:900e24b27bfb, 2017-09-25 (annotated)

Committer:
andrewboyson
Date:
Mon Sep 25 07:09:32 2017 +0000
Revision:
36:900e24b27bfb
Parent:
35:93c39d260a83
Child:
37:793b39683406
Corrected DNS NameCompare to correctly compare a shortcut name

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 13:9cd54f7db57a 1 #include "mbed.h"
andrewboyson 13:9cd54f7db57a 2 #include "log.h"
andrewboyson 13:9cd54f7db57a 3 #include "net.h"
andrewboyson 14:e75a59c1123d 4 #include "ip4.h"
andrewboyson 14:e75a59c1123d 5 #include "ip6.h"
andrewboyson 13:9cd54f7db57a 6 #include "dhcp.h"
andrewboyson 13:9cd54f7db57a 7 #include "dns.h"
andrewboyson 13:9cd54f7db57a 8 #include "udp.h"
andrewboyson 13:9cd54f7db57a 9 #include "slaac.h"
andrewboyson 13:9cd54f7db57a 10 #include "dnshdr.h"
andrewboyson 13:9cd54f7db57a 11 #include "dnsname.h"
andrewboyson 13:9cd54f7db57a 12
andrewboyson 22:914b970356f0 13 #define DEBUG false
andrewboyson 13:9cd54f7db57a 14
andrewboyson 13:9cd54f7db57a 15 #define TIME_OUT_SENT 3
andrewboyson 13:9cd54f7db57a 16
andrewboyson 13:9cd54f7db57a 17 #define MDNS_UNICAST false
andrewboyson 13:9cd54f7db57a 18
andrewboyson 35:93c39d260a83 19 char DnsQueryName[DNS_MAX_LABEL_LENGTH+1];
andrewboyson 13:9cd54f7db57a 20 uint32_t DnsQueryIp4 = 0;
andrewboyson 13:9cd54f7db57a 21 char DnsQueryIp6[16];
andrewboyson 13:9cd54f7db57a 22
andrewboyson 30:e34173b7585c 23 char DnsQueryRecordType = DNS_RECORD_NONE;
andrewboyson 30:e34173b7585c 24 int DnsQueryProtocol = DNS_PROTOCOL_NONE;
andrewboyson 30:e34173b7585c 25 bool DnsQueryIsBusy = false;
andrewboyson 13:9cd54f7db57a 26
andrewboyson 13:9cd54f7db57a 27 static uint32_t started = 0;
andrewboyson 13:9cd54f7db57a 28 static uint32_t elapsed = 0;
andrewboyson 13:9cd54f7db57a 29 static void reap()
andrewboyson 13:9cd54f7db57a 30 {
andrewboyson 13:9cd54f7db57a 31 if (!DnsQueryIsBusy) return;
andrewboyson 13:9cd54f7db57a 32
andrewboyson 13:9cd54f7db57a 33 if (elapsed - started >= TIME_OUT_SENT)
andrewboyson 13:9cd54f7db57a 34 {
andrewboyson 13:9cd54f7db57a 35 char text[100];
andrewboyson 13:9cd54f7db57a 36 LogTimeF("DNS reaped ongoing request for ");
andrewboyson 13:9cd54f7db57a 37 if (DnsQueryName[0]) LogF("name %s", DnsQueryName);
andrewboyson 13:9cd54f7db57a 38 if (DnsQueryIp4)
andrewboyson 13:9cd54f7db57a 39 {
andrewboyson 14:e75a59c1123d 40 Ip4AddressToString(DnsQueryIp4, sizeof(text), text);
andrewboyson 13:9cd54f7db57a 41 LogF("ip4 %s", text);
andrewboyson 13:9cd54f7db57a 42 }
andrewboyson 13:9cd54f7db57a 43 if (DnsQueryIp6[0])
andrewboyson 13:9cd54f7db57a 44 {
andrewboyson 14:e75a59c1123d 45 Ip6AddressToString(DnsQueryIp6, sizeof(text), text);
andrewboyson 13:9cd54f7db57a 46 LogF("ip6 %s", text);
andrewboyson 13:9cd54f7db57a 47 }
andrewboyson 13:9cd54f7db57a 48 LogF("\r\n");
andrewboyson 13:9cd54f7db57a 49
andrewboyson 13:9cd54f7db57a 50 DnsQueryName[0] = 0;
andrewboyson 13:9cd54f7db57a 51 DnsQueryIp4 = 0;
andrewboyson 13:9cd54f7db57a 52 DnsQueryIp6[0] = 0;
andrewboyson 13:9cd54f7db57a 53 DnsQueryIsBusy = false;
andrewboyson 13:9cd54f7db57a 54 started = 0;
andrewboyson 13:9cd54f7db57a 55 DnsQueryProtocol = DNS_PROTOCOL_NONE;
andrewboyson 30:e34173b7585c 56 DnsQueryRecordType = DNS_RECORD_NONE;
andrewboyson 13:9cd54f7db57a 57 }
andrewboyson 13:9cd54f7db57a 58 }
andrewboyson 13:9cd54f7db57a 59 void DnsQueryTick()
andrewboyson 13:9cd54f7db57a 60 {
andrewboyson 13:9cd54f7db57a 61 elapsed++;
andrewboyson 13:9cd54f7db57a 62 reap();
andrewboyson 13:9cd54f7db57a 63 }
andrewboyson 13:9cd54f7db57a 64 void DnsQueryIp4FromName(char * name, int protocol)
andrewboyson 13:9cd54f7db57a 65 {
andrewboyson 32:679654f2d023 66 DnsMakeFullNameFromName(protocol, name, sizeof(DnsQueryName), DnsQueryName);
andrewboyson 13:9cd54f7db57a 67 DnsQueryIp4 = 0;
andrewboyson 13:9cd54f7db57a 68 DnsQueryIp6[0] = 0;
andrewboyson 13:9cd54f7db57a 69 DnsQueryIsBusy = true;
andrewboyson 13:9cd54f7db57a 70 started = elapsed;
andrewboyson 13:9cd54f7db57a 71 DnsQueryProtocol = protocol;
andrewboyson 30:e34173b7585c 72 DnsQueryRecordType = DNS_RECORD_A;
andrewboyson 13:9cd54f7db57a 73 }
andrewboyson 13:9cd54f7db57a 74 void DnsQueryIp6FromName(char * name, int protocol)
andrewboyson 13:9cd54f7db57a 75 {
andrewboyson 32:679654f2d023 76 DnsMakeFullNameFromName(protocol, name, sizeof(DnsQueryName), DnsQueryName);
andrewboyson 13:9cd54f7db57a 77 DnsQueryIp4 = 0;
andrewboyson 13:9cd54f7db57a 78 DnsQueryIp6[0] = 0;
andrewboyson 13:9cd54f7db57a 79 DnsQueryIsBusy = true;
andrewboyson 13:9cd54f7db57a 80 started = elapsed;
andrewboyson 13:9cd54f7db57a 81 DnsQueryProtocol = protocol;
andrewboyson 30:e34173b7585c 82 DnsQueryRecordType = DNS_RECORD_AAAA;
andrewboyson 13:9cd54f7db57a 83 }
andrewboyson 13:9cd54f7db57a 84 void DnsQueryNameFromIp4(uint32_t ip, int protocol)
andrewboyson 13:9cd54f7db57a 85 {
andrewboyson 13:9cd54f7db57a 86 DnsQueryName[0] = 0;
andrewboyson 13:9cd54f7db57a 87 DnsQueryIp4 = ip;
andrewboyson 13:9cd54f7db57a 88 DnsQueryIp6[0] = 0;
andrewboyson 13:9cd54f7db57a 89 DnsQueryIsBusy = true;
andrewboyson 13:9cd54f7db57a 90 started = elapsed;
andrewboyson 13:9cd54f7db57a 91 DnsQueryProtocol = protocol;
andrewboyson 30:e34173b7585c 92 DnsQueryRecordType = DNS_RECORD_PTR;
andrewboyson 13:9cd54f7db57a 93 }
andrewboyson 13:9cd54f7db57a 94 void DnsQueryNameFromIp6(char* ip, int protocol)
andrewboyson 13:9cd54f7db57a 95 {
andrewboyson 13:9cd54f7db57a 96 DnsQueryName[0] = 0;
andrewboyson 13:9cd54f7db57a 97 DnsQueryIp4 = 0;
andrewboyson 36:900e24b27bfb 98 Ip6Copy(DnsQueryIp6, ip);
andrewboyson 13:9cd54f7db57a 99 DnsQueryIsBusy = true;
andrewboyson 13:9cd54f7db57a 100 started = elapsed;
andrewboyson 13:9cd54f7db57a 101 DnsQueryProtocol = protocol;
andrewboyson 30:e34173b7585c 102 DnsQueryRecordType = DNS_RECORD_PTR;
andrewboyson 30:e34173b7585c 103 }
andrewboyson 30:e34173b7585c 104 static void logQuery()
andrewboyson 30:e34173b7585c 105 {
andrewboyson 30:e34173b7585c 106 char text[60];
andrewboyson 30:e34173b7585c 107 DnsProtocolToString(DnsQueryProtocol, sizeof(text), text);
andrewboyson 32:679654f2d023 108 LogTimeF("DnsQuery sent %s request for ", text);
andrewboyson 30:e34173b7585c 109 DnsRecordTypeToString(DnsQueryRecordType, sizeof(text), text);
andrewboyson 30:e34173b7585c 110 LogF("%s ", text);
andrewboyson 30:e34173b7585c 111 if (DnsQueryIp4) //Reverse
andrewboyson 30:e34173b7585c 112 {
andrewboyson 30:e34173b7585c 113 Ip4AddressToString(DnsQueryIp4, sizeof(text), text);
andrewboyson 30:e34173b7585c 114 LogF("%s\r\n", text);
andrewboyson 30:e34173b7585c 115 }
andrewboyson 30:e34173b7585c 116 else if (DnsQueryIp6[0])
andrewboyson 30:e34173b7585c 117 {
andrewboyson 30:e34173b7585c 118 Ip6AddressToString(DnsQueryIp6, sizeof(text), text);
andrewboyson 30:e34173b7585c 119 LogF("%s\r\n", text);
andrewboyson 30:e34173b7585c 120 }
andrewboyson 30:e34173b7585c 121 else //Forward
andrewboyson 30:e34173b7585c 122 {
andrewboyson 30:e34173b7585c 123 LogF("%s\r\n", DnsQueryName);
andrewboyson 30:e34173b7585c 124 }
andrewboyson 13:9cd54f7db57a 125 }
andrewboyson 13:9cd54f7db57a 126 int DnsQueryPoll(int* pSize)
andrewboyson 13:9cd54f7db57a 127 {
andrewboyson 13:9cd54f7db57a 128 if (!DnsQueryIsBusy) return DO_NOTHING;
andrewboyson 13:9cd54f7db57a 129 if (DnsQueryProtocol == DNS_PROTOCOL_UDNS && DhcpLocalIp == 0) return DO_NOTHING;
andrewboyson 13:9cd54f7db57a 130
andrewboyson 32:679654f2d023 131 if (DEBUG) logQuery();
andrewboyson 30:e34173b7585c 132
andrewboyson 13:9cd54f7db57a 133 static uint16_t id = 0;
andrewboyson 13:9cd54f7db57a 134 DnsHdrId = ++id;
andrewboyson 13:9cd54f7db57a 135 DnsHdrIsReply = false;
andrewboyson 13:9cd54f7db57a 136 DnsHdrIsRecursiveQuery = false;
andrewboyson 13:9cd54f7db57a 137
andrewboyson 13:9cd54f7db57a 138 DnsHdrQdcount = 1;
andrewboyson 13:9cd54f7db57a 139 DnsHdrAncount = 0;
andrewboyson 13:9cd54f7db57a 140 DnsHdrNscount = 0;
andrewboyson 13:9cd54f7db57a 141 DnsHdrArcount = 0;
andrewboyson 13:9cd54f7db57a 142
andrewboyson 13:9cd54f7db57a 143 DnsHdrWrite();
andrewboyson 13:9cd54f7db57a 144 char* p = DnsHdrData;
andrewboyson 13:9cd54f7db57a 145
andrewboyson 30:e34173b7585c 146 if (DnsQueryIp4 ) DnsNameEncodeIp4(DnsQueryIp4, &p);
andrewboyson 30:e34173b7585c 147 else if (DnsQueryIp6[0]) DnsNameEncodeIp6(DnsQueryIp6, &p);
andrewboyson 30:e34173b7585c 148 else DnsNameEncode (DnsQueryName, &p);
andrewboyson 30:e34173b7585c 149
andrewboyson 30:e34173b7585c 150 *p++ = 0;
andrewboyson 30:e34173b7585c 151 *p++ = DnsQueryRecordType;
andrewboyson 13:9cd54f7db57a 152 *p++ = DnsQueryProtocol == DNS_PROTOCOL_MDNS && MDNS_UNICAST ? 0x80 : 0; //Set the 15th bit (UNICAST_RESPONSE) to 1 if MDNS
andrewboyson 13:9cd54f7db57a 153 *p++ = 1; //QCLASS_IN = 1 - internet
andrewboyson 13:9cd54f7db57a 154
andrewboyson 13:9cd54f7db57a 155 *pSize = p - DnsHdrPacket;
andrewboyson 13:9cd54f7db57a 156
andrewboyson 13:9cd54f7db57a 157 DnsQueryIsBusy = false;
andrewboyson 13:9cd54f7db57a 158
andrewboyson 13:9cd54f7db57a 159 switch (DnsQueryProtocol)
andrewboyson 13:9cd54f7db57a 160 {
andrewboyson 13:9cd54f7db57a 161 case DNS_PROTOCOL_UDNS: return UNICAST_DNS; //IPv6 ==> NdpDnsServer; IPv4 ==> DhcpDnsServer
andrewboyson 13:9cd54f7db57a 162 case DNS_PROTOCOL_MDNS: return MULTICAST_MDNS;
andrewboyson 13:9cd54f7db57a 163 case DNS_PROTOCOL_LLMNR: return MULTICAST_LLMNR;
andrewboyson 13:9cd54f7db57a 164 default:
andrewboyson 13:9cd54f7db57a 165 LogTimeF("DNS unknown query protocol %d\r\n", DnsQueryProtocol);
andrewboyson 13:9cd54f7db57a 166 return DO_NOTHING;
andrewboyson 13:9cd54f7db57a 167 }
andrewboyson 13:9cd54f7db57a 168 }