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12471842 PL |
1 | /* |
2 | * This file is part of PowerDNS or dnsdist. | |
3 | * Copyright -- PowerDNS.COM B.V. and its contributors | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of version 2 of the GNU General Public License as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * In addition, for the avoidance of any doubt, permission is granted to | |
10 | * link this program with OpenSSL and to (re)distribute the binaries | |
11 | * produced as the result of such linking. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
21 | */ | |
a0a276c2 BH |
22 | #ifndef PDNS_DNSWRITER_HH |
23 | #define PDNS_DNSWRITER_HH | |
24 | ||
25 | #include <string> | |
26 | #include <vector> | |
bca6643b | 27 | #include <map> |
5a57d2ea | 28 | #include "dns.hh" |
4a51ff72 | 29 | #include "dnsname.hh" |
10f4eea8 | 30 | #include "namespaces.hh" |
f4352636 | 31 | #include "iputils.hh" |
1bc3ebb6 | 32 | #include <arpa/inet.h> |
802a93d0 | 33 | |
34 | ||
950cfe0f | 35 | /** this class can be used to write DNS packets. It knows about DNS in the sense that it makes |
a0a276c2 BH |
36 | the packet header and record headers. |
37 | ||
38 | The model is: | |
39 | ||
40 | packetheader (recordheader recordcontent)* | |
41 | ||
42 | The packetheader needs to be updated with the amount of packets of each kind (answer, auth, additional) | |
950cfe0f | 43 | |
a0a276c2 BH |
44 | Each recordheader contains the length of a dns record. |
45 | ||
46 | Calling convention: | |
47 | ||
48 | vector<uint8_t> content; | |
703761cc | 49 | DNSPacketWriter dpw(content, const string& qname, uint16_t qtype, uint16_t qclass=QClass:IN); // sets the question |
7738a23f | 50 | dpw.startrecord("this.is.an.ip.address.", ns_t_a); // does nothing, except store qname and qtype |
a0a276c2 | 51 | dpw.xfr32BitInt(0x01020304); // adds 4 bytes (0x01020304) to the record buffer |
7738a23f | 52 | dpw.startrecord("this.is.an.ip.address.", ns_t_a); // aha! writes out dnsrecord header containing qname and qtype and length 4, plus the recordbuffer, which gets emptied |
a0a276c2 BH |
53 | // new qname and qtype are stored |
54 | dpw.xfr32BitInt(0x04030201); // adds 4 bytes (0x04030201) to the record buffer | |
55 | dpw.commit(); // writes out dnsrecord header containing qname and qtype and length 4, plus the recordbuffer | |
56 | ||
57 | // content now contains the ready packet, with 1 question and 2 answers | |
58 | ||
59 | */ | |
60 | ||
f3f4938f | 61 | class DNSPacketWriter : public boost::noncopyable |
a0a276c2 | 62 | { |
a2ce25e4 | 63 | |
a0a276c2 | 64 | public: |
bca6643b | 65 | //! Start a DNS Packet in the vector passed, with question qname, qtype and qclass |
c2f3be9d | 66 | DNSPacketWriter(vector<uint8_t>& content, const DNSName& qname, uint16_t qtype, uint16_t qclass=QClass::IN, uint8_t opcode=0); |
950cfe0f PD |
67 | |
68 | /** Start a new DNS record within this packet for namq, qtype, ttl, class and in the requested place. Note that packets can only be written in natural order - | |
bca6643b | 69 | ANSWER, AUTHORITY, ADDITIONAL */ |
e693ff5a | 70 | void startRecord(const DNSName& name, uint16_t qtype, uint32_t ttl=3600, uint16_t qclass=QClass::IN, DNSResourceRecord::Place place=DNSResourceRecord::ANSWER, bool compress=true); |
bca6643b BH |
71 | |
72 | /** Shorthand way to add an Opt-record, for example for EDNS0 purposes */ | |
7f7b8d55 | 73 | typedef vector<pair<uint16_t,std::string> > optvect_t; |
d6c335ab | 74 | void addOpt(const uint16_t udpsize, const uint16_t extRCode, const uint16_t ednsFlags, const optvect_t& options=optvect_t(), const uint8_t version=0); |
a0a276c2 | 75 | |
bca6643b BH |
76 | /** needs to be called after the last record is added, but can be called again and again later on. Is called internally by startRecord too. |
77 | The content of the vector<> passed to the constructor is inconsistent until commit is called. | |
78 | */ | |
79 | void commit(); | |
80 | ||
dffbaa08 | 81 | uint32_t size(); // needs to be 32 bit because otherwise we don't see the wrap coming when it happened! |
10321a98 BH |
82 | |
83 | /** Should the packet have grown too big for the writer's liking, rollback removes the record currently being written */ | |
84 | void rollback(); | |
85 | ||
add935a2 PD |
86 | /** Discard all content except the question section */ |
87 | void truncate(); | |
88 | ||
341930bb | 89 | void xfr48BitInt(uint64_t val); |
a0a276c2 BH |
90 | void xfr32BitInt(uint32_t val); |
91 | void xfr16BitInt(uint16_t val); | |
8bf26468 BH |
92 | void xfrType(uint16_t val) |
93 | { | |
94 | xfr16BitInt(val); | |
95 | } | |
cbf0e7f3 BH |
96 | void xfrIP(const uint32_t& val) |
97 | { | |
ea634573 | 98 | xfr32BitInt(htonl(val)); |
cbf0e7f3 | 99 | } |
950cfe0f | 100 | void xfrIP6(const std::string& val) |
b9b28916 AT |
101 | { |
102 | xfrBlob(val,16); | |
103 | } | |
f4352636 PD |
104 | |
105 | void xfrCAWithoutPort(uint8_t version, ComboAddress &val) | |
106 | { | |
107 | if (version == 4) xfrIP(val.sin4.sin_addr.s_addr); | |
108 | else if (version == 6) { | |
109 | string blob; | |
110 | blob.assign((const char*)val.sin6.sin6_addr.s6_addr, 16); | |
111 | xfrBlob(blob, 16); | |
112 | } | |
113 | else throw runtime_error("invalid IP protocol"); | |
114 | } | |
115 | ||
116 | void xfrCAPort(ComboAddress &val) | |
117 | { | |
118 | uint16_t port; | |
119 | port = val.sin4.sin_port; | |
120 | xfr16BitInt(port); | |
121 | } | |
122 | ||
8bf26468 BH |
123 | void xfrTime(const uint32_t& val) |
124 | { | |
125 | xfr32BitInt(val); | |
126 | } | |
127 | ||
a0a276c2 BH |
128 | void xfr8BitInt(uint8_t val); |
129 | ||
f21fc0aa | 130 | void xfrName(const DNSName& label, bool compress=false, bool noDot=false); |
84e1142d | 131 | void xfrText(const string& text, bool multi=false, bool lenField=true); |
948a927f | 132 | void xfrUnquotedText(const string& text, bool lenField); |
06ffdc52 | 133 | void xfrBlob(const string& blob, int len=-1); |
2fe9d6f7 | 134 | void xfrBlobNoSpaces(const string& blob, int len=-1); |
e4090157 | 135 | void xfrHexBlob(const string& blob, bool keepReading=false); |
bca6643b | 136 | |
8e97e9a3 | 137 | dnsheader* getHeader(); |
e636cab2 | 138 | void getRecordPayload(string& records); // call __before commit__ |
ea634573 | 139 | |
950cfe0f | 140 | void setCanonic(bool val) |
f3f4938f BH |
141 | { |
142 | d_canonic=val; | |
143 | } | |
144 | ||
950cfe0f | 145 | void setLowercase(bool val) |
7f5bf0ba BH |
146 | { |
147 | d_lowerCase=val; | |
148 | } | |
3f45f34d BH |
149 | vector <uint8_t>& getContent() |
150 | { | |
151 | return d_content; | |
152 | } | |
d476d7fb | 153 | bool eof() { return true; } // we don't know how long the record should be |
7f5bf0ba | 154 | |
ddb79bca AT |
155 | const string getRemaining() const { |
156 | return ""; | |
157 | } | |
a0a276c2 | 158 | private: |
802a93d0 | 159 | uint16_t lookupName(const DNSName& name, uint16_t* matchlen); |
fea4599a | 160 | vector<uint16_t> d_namepositions; |
78817f22 | 161 | // We declare 1 uint_16 in the public section, these 3 align on a 8-byte boundry |
78817f22 PL |
162 | uint16_t d_sor; |
163 | uint16_t d_rollbackmarker; // start of last complete packet, for rollback | |
164 | ||
57e5f5f7 | 165 | vector <uint8_t>& d_content; |
c2f3be9d | 166 | DNSName d_qname; |
78817f22 | 167 | |
add935a2 | 168 | uint16_t d_truncatemarker; // end of header, for truncate |
e693ff5a | 169 | DNSResourceRecord::Place d_recordplace; |
7f5bf0ba | 170 | bool d_canonic, d_lowerCase; |
a0a276c2 | 171 | }; |
213f6de6 BH |
172 | |
173 | typedef vector<pair<string::size_type, string::size_type> > labelparts_t; | |
c2f3be9d | 174 | // bool labeltokUnescape(labelparts_t& parts, const DNSName& label); |
bac8f21b | 175 | std::vector<string> segmentDNSText(const string& text); // from dnslabeltext.rl |
be6fbc68 | 176 | std::deque<string> segmentDNSName(const string& input ); // from dnslabeltext.rl |
a0a276c2 | 177 | #endif |