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/dnsreply.cpp@57:e0fb648acf48, 2017-11-28 (annotated)
- Committer:
- andrewboyson
- Date:
- Tue Nov 28 17:05:46 2017 +0000
- Revision:
- 57:e0fb648acf48
- Parent:
- 50:492f2d2954e4
- Child:
- 58:d48c899e482f
Added TFTP
Who changed what in which revision?
User | Revision | Line number | New 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 "ip4.h" |
andrewboyson | 37:793b39683406 | 6 | #include "ip6.h" |
andrewboyson | 50:492f2d2954e4 | 7 | #include "nr4.h" |
andrewboyson | 50:492f2d2954e4 | 8 | #include "nr6.h" |
andrewboyson | 37:793b39683406 | 9 | #include "dns.h" |
andrewboyson | 37:793b39683406 | 10 | #include "dnshdr.h" |
andrewboyson | 37:793b39683406 | 11 | #include "dnsname.h" |
andrewboyson | 37:793b39683406 | 12 | #include "dhcp.h" |
andrewboyson | 13:9cd54f7db57a | 13 | |
andrewboyson | 37:793b39683406 | 14 | bool DnsReplyTrace = false; |
andrewboyson | 13:9cd54f7db57a | 15 | |
andrewboyson | 13:9cd54f7db57a | 16 | char DnsReplyRecordName[256]; |
andrewboyson | 13:9cd54f7db57a | 17 | uint32_t DnsReplyRecordNameAsIp4 = 0; |
andrewboyson | 13:9cd54f7db57a | 18 | char DnsReplyRecordNameAsIp6[16]; |
andrewboyson | 13:9cd54f7db57a | 19 | char DnsReplyName[64]; |
andrewboyson | 13:9cd54f7db57a | 20 | uint32_t DnsReplyIp4 = 0; |
andrewboyson | 13:9cd54f7db57a | 21 | char DnsReplyIp6[16]; |
andrewboyson | 13:9cd54f7db57a | 22 | |
andrewboyson | 13:9cd54f7db57a | 23 | static char *p; |
andrewboyson | 13:9cd54f7db57a | 24 | static int recordNameOffset; |
andrewboyson | 13:9cd54f7db57a | 25 | static int recordType; |
andrewboyson | 13:9cd54f7db57a | 26 | static int recordDataLength; |
andrewboyson | 13:9cd54f7db57a | 27 | static char* pRecordData; |
andrewboyson | 13:9cd54f7db57a | 28 | |
andrewboyson | 13:9cd54f7db57a | 29 | static int scanQuery() |
andrewboyson | 13:9cd54f7db57a | 30 | { |
andrewboyson | 13:9cd54f7db57a | 31 | int recordNameLength = DnsNameLength(p); |
andrewboyson | 43:bc028d5a6424 | 32 | if (!recordNameLength) return -1; //failure |
andrewboyson | 13:9cd54f7db57a | 33 | |
andrewboyson | 13:9cd54f7db57a | 34 | recordNameOffset = DnsNameIndexFromPointer(p); |
andrewboyson | 13:9cd54f7db57a | 35 | p += recordNameLength; |
andrewboyson | 13:9cd54f7db57a | 36 | |
andrewboyson | 13:9cd54f7db57a | 37 | p++ ; //skip the first byte of the type |
andrewboyson | 13:9cd54f7db57a | 38 | recordType = *p++; |
andrewboyson | 13:9cd54f7db57a | 39 | |
andrewboyson | 13:9cd54f7db57a | 40 | p += 2; //skip the class |
andrewboyson | 13:9cd54f7db57a | 41 | |
andrewboyson | 13:9cd54f7db57a | 42 | return 0; //success |
andrewboyson | 13:9cd54f7db57a | 43 | } |
andrewboyson | 13:9cd54f7db57a | 44 | |
andrewboyson | 13:9cd54f7db57a | 45 | static int scanAnswer() |
andrewboyson | 13:9cd54f7db57a | 46 | { |
andrewboyson | 13:9cd54f7db57a | 47 | int recordNameLength = DnsNameLength(p); |
andrewboyson | 43:bc028d5a6424 | 48 | if (!recordNameLength) return -1; //failure |
andrewboyson | 13:9cd54f7db57a | 49 | |
andrewboyson | 13:9cd54f7db57a | 50 | recordNameOffset = DnsNameIndexFromPointer(p); |
andrewboyson | 13:9cd54f7db57a | 51 | p += recordNameLength; |
andrewboyson | 13:9cd54f7db57a | 52 | |
andrewboyson | 13:9cd54f7db57a | 53 | p++ ; //skip the first byte of the type |
andrewboyson | 13:9cd54f7db57a | 54 | recordType = *p++; |
andrewboyson | 13:9cd54f7db57a | 55 | |
andrewboyson | 13:9cd54f7db57a | 56 | p += 6; //skip the class, TTL |
andrewboyson | 13:9cd54f7db57a | 57 | recordDataLength = 0; |
andrewboyson | 13:9cd54f7db57a | 58 | recordDataLength |= *p++ << 8; |
andrewboyson | 13:9cd54f7db57a | 59 | recordDataLength |= *p++; |
andrewboyson | 13:9cd54f7db57a | 60 | |
andrewboyson | 13:9cd54f7db57a | 61 | pRecordData = p; //record the start of the data |
andrewboyson | 13:9cd54f7db57a | 62 | |
andrewboyson | 13:9cd54f7db57a | 63 | p += recordDataLength; //Move to the start of the next record |
andrewboyson | 13:9cd54f7db57a | 64 | |
andrewboyson | 13:9cd54f7db57a | 65 | return 0; //success |
andrewboyson | 13:9cd54f7db57a | 66 | } |
andrewboyson | 13:9cd54f7db57a | 67 | static void readAnswer() |
andrewboyson | 13:9cd54f7db57a | 68 | { |
andrewboyson | 13:9cd54f7db57a | 69 | DnsReplyRecordName[0] = 0; |
andrewboyson | 13:9cd54f7db57a | 70 | DnsReplyRecordNameAsIp4 = 0; |
andrewboyson | 13:9cd54f7db57a | 71 | DnsReplyRecordNameAsIp6[0] = 0; |
andrewboyson | 13:9cd54f7db57a | 72 | DnsReplyName[0] = 0; |
andrewboyson | 13:9cd54f7db57a | 73 | DnsReplyIp4 = 0; |
andrewboyson | 13:9cd54f7db57a | 74 | DnsReplyIp6[0] = 0; |
andrewboyson | 13:9cd54f7db57a | 75 | |
andrewboyson | 13:9cd54f7db57a | 76 | switch (recordType) |
andrewboyson | 13:9cd54f7db57a | 77 | { |
andrewboyson | 13:9cd54f7db57a | 78 | case DNS_RECORD_A: |
andrewboyson | 13:9cd54f7db57a | 79 | case DNS_RECORD_AAAA: |
andrewboyson | 13:9cd54f7db57a | 80 | case DNS_RECORD_PTR: |
andrewboyson | 15:6ca6778168b1 | 81 | case DNS_RECORD_SRV: |
andrewboyson | 15:6ca6778168b1 | 82 | case DNS_RECORD_TXT: |
andrewboyson | 13:9cd54f7db57a | 83 | break; |
andrewboyson | 43:bc028d5a6424 | 84 | default: |
andrewboyson | 15:6ca6778168b1 | 85 | return; |
andrewboyson | 15:6ca6778168b1 | 86 | } |
andrewboyson | 13:9cd54f7db57a | 87 | |
andrewboyson | 37:793b39683406 | 88 | DnsNameDecodePtr(recordNameOffset, sizeof(DnsReplyRecordName), DnsReplyRecordName); |
andrewboyson | 13:9cd54f7db57a | 89 | DnsNameDecodeIp4(recordNameOffset, &DnsReplyRecordNameAsIp4); |
andrewboyson | 13:9cd54f7db57a | 90 | DnsNameDecodeIp6(recordNameOffset, DnsReplyRecordNameAsIp6); |
andrewboyson | 15:6ca6778168b1 | 91 | |
andrewboyson | 13:9cd54f7db57a | 92 | switch (recordType) |
andrewboyson | 13:9cd54f7db57a | 93 | { |
andrewboyson | 13:9cd54f7db57a | 94 | case DNS_RECORD_A: |
andrewboyson | 43:bc028d5a6424 | 95 | if (recordDataLength != 4) return; |
andrewboyson | 13:9cd54f7db57a | 96 | memcpy(&DnsReplyIp4, pRecordData, 4); |
andrewboyson | 13:9cd54f7db57a | 97 | break; |
andrewboyson | 13:9cd54f7db57a | 98 | case DNS_RECORD_AAAA: |
andrewboyson | 43:bc028d5a6424 | 99 | if (recordDataLength != 16) return; |
andrewboyson | 13:9cd54f7db57a | 100 | memcpy(DnsReplyIp6, pRecordData, 16); |
andrewboyson | 13:9cd54f7db57a | 101 | break; |
andrewboyson | 13:9cd54f7db57a | 102 | case DNS_RECORD_PTR: |
andrewboyson | 43:bc028d5a6424 | 103 | if (recordDataLength > DNS_MAX_LABEL_LENGTH) return; |
andrewboyson | 37:793b39683406 | 104 | DnsNameDecodePtr(DnsNameIndexFromPointer(pRecordData), sizeof(DnsReplyName), DnsReplyName); |
andrewboyson | 13:9cd54f7db57a | 105 | break; |
andrewboyson | 13:9cd54f7db57a | 106 | } |
andrewboyson | 13:9cd54f7db57a | 107 | } |
andrewboyson | 13:9cd54f7db57a | 108 | |
andrewboyson | 32:679654f2d023 | 109 | static void sendToDnsCache(int dnsProtocol) |
andrewboyson | 30:e34173b7585c | 110 | { |
andrewboyson | 32:679654f2d023 | 111 | char strippedName[100]; |
andrewboyson | 32:679654f2d023 | 112 | if (DnsReplyRecordName[0]) DnsStripNameFromFullName(dnsProtocol, DnsReplyRecordName, sizeof(strippedName), strippedName); |
andrewboyson | 32:679654f2d023 | 113 | if (DnsReplyName[0] ) DnsStripNameFromFullName(dnsProtocol, DnsReplyName , sizeof(strippedName), strippedName); |
andrewboyson | 32:679654f2d023 | 114 | |
andrewboyson | 50:492f2d2954e4 | 115 | if (DnsReplyIp4 && DnsReplyRecordName[0]) Nr4AddIpRecord(DnsReplyIp4, strippedName, dnsProtocol); |
andrewboyson | 50:492f2d2954e4 | 116 | if (DnsReplyIp6[0] && DnsReplyRecordName[0]) Nr6AddIpRecord(DnsReplyIp6, strippedName, dnsProtocol); |
andrewboyson | 50:492f2d2954e4 | 117 | if (DnsReplyRecordNameAsIp4 && DnsReplyName[0] ) Nr4AddIpRecord(DnsReplyRecordNameAsIp4, strippedName, dnsProtocol); |
andrewboyson | 50:492f2d2954e4 | 118 | if (DnsReplyRecordNameAsIp6[0] && DnsReplyName[0] ) Nr6AddIpRecord(DnsReplyRecordNameAsIp6, strippedName, dnsProtocol); |
andrewboyson | 30:e34173b7585c | 119 | } |
andrewboyson | 37:793b39683406 | 120 | int DnsReplyHandle(void (*traceback)(void), int dnsProtocol, int *pSize) |
andrewboyson | 57:e0fb648acf48 | 121 | { |
andrewboyson | 57:e0fb648acf48 | 122 | bool ok = true; |
andrewboyson | 57:e0fb648acf48 | 123 | if (!DnsHdrAncount) ok = false; |
andrewboyson | 57:e0fb648acf48 | 124 | |
andrewboyson | 57:e0fb648acf48 | 125 | p = DnsHdrData; |
andrewboyson | 57:e0fb648acf48 | 126 | |
andrewboyson | 57:e0fb648acf48 | 127 | if (ok) |
andrewboyson | 57:e0fb648acf48 | 128 | { |
andrewboyson | 57:e0fb648acf48 | 129 | for (int q = 0; q < DnsHdrQdcount; q++) |
andrewboyson | 57:e0fb648acf48 | 130 | { |
andrewboyson | 57:e0fb648acf48 | 131 | if (scanQuery()) |
andrewboyson | 57:e0fb648acf48 | 132 | { |
andrewboyson | 57:e0fb648acf48 | 133 | ok = false; |
andrewboyson | 57:e0fb648acf48 | 134 | break; |
andrewboyson | 57:e0fb648acf48 | 135 | } |
andrewboyson | 57:e0fb648acf48 | 136 | } |
andrewboyson | 57:e0fb648acf48 | 137 | } |
andrewboyson | 57:e0fb648acf48 | 138 | if (ok) |
andrewboyson | 57:e0fb648acf48 | 139 | { |
andrewboyson | 57:e0fb648acf48 | 140 | for (int a = 0; a < DnsHdrAncount; a++) |
andrewboyson | 57:e0fb648acf48 | 141 | { |
andrewboyson | 57:e0fb648acf48 | 142 | if (scanAnswer()) |
andrewboyson | 57:e0fb648acf48 | 143 | { |
andrewboyson | 57:e0fb648acf48 | 144 | ok = false; |
andrewboyson | 57:e0fb648acf48 | 145 | break; |
andrewboyson | 57:e0fb648acf48 | 146 | } |
andrewboyson | 57:e0fb648acf48 | 147 | readAnswer(); |
andrewboyson | 57:e0fb648acf48 | 148 | sendToDnsCache(dnsProtocol); |
andrewboyson | 57:e0fb648acf48 | 149 | } |
andrewboyson | 57:e0fb648acf48 | 150 | } |
andrewboyson | 57:e0fb648acf48 | 151 | |
andrewboyson | 57:e0fb648acf48 | 152 | NetTraceHostCheckIp6(DnsReplyIp6); |
andrewboyson | 57:e0fb648acf48 | 153 | NetTraceHostCheckIp6(DnsReplyRecordNameAsIp6); |
andrewboyson | 57:e0fb648acf48 | 154 | |
andrewboyson | 57:e0fb648acf48 | 155 | if (DnsReplyTrace || NetTraceHostGetMatched()) |
andrewboyson | 37:793b39683406 | 156 | { |
andrewboyson | 43:bc028d5a6424 | 157 | if (NetTraceNewLine) Log("\r\n"); |
andrewboyson | 43:bc028d5a6424 | 158 | LogTimeF("DnsReply received\r\n"); |
andrewboyson | 43:bc028d5a6424 | 159 | if (NetTraceStack) traceback(); |
andrewboyson | 37:793b39683406 | 160 | DnsHdrLog(dnsProtocol); |
andrewboyson | 37:793b39683406 | 161 | } |
andrewboyson | 13:9cd54f7db57a | 162 | |
andrewboyson | 13:9cd54f7db57a | 163 | |
andrewboyson | 13:9cd54f7db57a | 164 | return DO_NOTHING; |
andrewboyson | 13:9cd54f7db57a | 165 | } |