]>
Commit | Line | Data |
---|---|---|
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 | */ | |
e8c59f2d | 22 | #pragma once |
a0a276c2 BH |
23 | #include <string> |
24 | #include <vector> | |
bca6643b | 25 | #include <map> |
5a57d2ea | 26 | #include "dns.hh" |
4a51ff72 | 27 | #include "dnsname.hh" |
10f4eea8 | 28 | #include "namespaces.hh" |
f4352636 | 29 | #include "iputils.hh" |
1bc3ebb6 | 30 | #include <arpa/inet.h> |
802a93d0 | 31 | |
32 | ||
950cfe0f | 33 | /** this class can be used to write DNS packets. It knows about DNS in the sense that it makes |
a0a276c2 BH |
34 | the packet header and record headers. |
35 | ||
36 | The model is: | |
37 | ||
38 | packetheader (recordheader recordcontent)* | |
39 | ||
40 | The packetheader needs to be updated with the amount of packets of each kind (answer, auth, additional) | |
950cfe0f | 41 | |
a0a276c2 BH |
42 | Each recordheader contains the length of a dns record. |
43 | ||
44 | Calling convention: | |
45 | ||
46 | vector<uint8_t> content; | |
703761cc | 47 | DNSPacketWriter dpw(content, const string& qname, uint16_t qtype, uint16_t qclass=QClass:IN); // sets the question |
7738a23f | 48 | dpw.startrecord("this.is.an.ip.address.", ns_t_a); // does nothing, except store qname and qtype |
a0a276c2 | 49 | dpw.xfr32BitInt(0x01020304); // adds 4 bytes (0x01020304) to the record buffer |
7738a23f | 50 | 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 |
51 | // new qname and qtype are stored |
52 | dpw.xfr32BitInt(0x04030201); // adds 4 bytes (0x04030201) to the record buffer | |
53 | dpw.commit(); // writes out dnsrecord header containing qname and qtype and length 4, plus the recordbuffer | |
54 | ||
55 | // content now contains the ready packet, with 1 question and 2 answers | |
56 | ||
57 | */ | |
58 | ||
f3f4938f | 59 | class DNSPacketWriter : public boost::noncopyable |
a0a276c2 | 60 | { |
a2ce25e4 | 61 | |
a0a276c2 | 62 | public: |
bca6643b | 63 | //! Start a DNS Packet in the vector passed, with question qname, qtype and qclass |
c2f3be9d | 64 | DNSPacketWriter(vector<uint8_t>& content, const DNSName& qname, uint16_t qtype, uint16_t qclass=QClass::IN, uint8_t opcode=0); |
950cfe0f PD |
65 | |
66 | /** 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 | 67 | ANSWER, AUTHORITY, ADDITIONAL */ |
e693ff5a | 68 | 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 |
69 | |
70 | /** Shorthand way to add an Opt-record, for example for EDNS0 purposes */ | |
7f7b8d55 | 71 | typedef vector<pair<uint16_t,std::string> > optvect_t; |
d6c335ab | 72 | 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 | 73 | |
bca6643b BH |
74 | /** 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. |
75 | The content of the vector<> passed to the constructor is inconsistent until commit is called. | |
76 | */ | |
77 | void commit(); | |
78 | ||
dffbaa08 | 79 | uint32_t size(); // needs to be 32 bit because otherwise we don't see the wrap coming when it happened! |
10321a98 BH |
80 | |
81 | /** Should the packet have grown too big for the writer's liking, rollback removes the record currently being written */ | |
82 | void rollback(); | |
83 | ||
add935a2 PD |
84 | /** Discard all content except the question section */ |
85 | void truncate(); | |
86 | ||
341930bb | 87 | void xfr48BitInt(uint64_t val); |
a0a276c2 BH |
88 | void xfr32BitInt(uint32_t val); |
89 | void xfr16BitInt(uint16_t val); | |
8bf26468 BH |
90 | void xfrType(uint16_t val) |
91 | { | |
92 | xfr16BitInt(val); | |
93 | } | |
cbf0e7f3 BH |
94 | void xfrIP(const uint32_t& val) |
95 | { | |
ea634573 | 96 | xfr32BitInt(htonl(val)); |
cbf0e7f3 | 97 | } |
950cfe0f | 98 | void xfrIP6(const std::string& val) |
b9b28916 AT |
99 | { |
100 | xfrBlob(val,16); | |
101 | } | |
f4352636 PD |
102 | |
103 | void xfrCAWithoutPort(uint8_t version, ComboAddress &val) | |
104 | { | |
105 | if (version == 4) xfrIP(val.sin4.sin_addr.s_addr); | |
106 | else if (version == 6) { | |
107 | string blob; | |
108 | blob.assign((const char*)val.sin6.sin6_addr.s6_addr, 16); | |
109 | xfrBlob(blob, 16); | |
110 | } | |
111 | else throw runtime_error("invalid IP protocol"); | |
112 | } | |
113 | ||
114 | void xfrCAPort(ComboAddress &val) | |
115 | { | |
116 | uint16_t port; | |
117 | port = val.sin4.sin_port; | |
118 | xfr16BitInt(port); | |
119 | } | |
120 | ||
8bf26468 BH |
121 | void xfrTime(const uint32_t& val) |
122 | { | |
123 | xfr32BitInt(val); | |
124 | } | |
125 | ||
a0a276c2 BH |
126 | void xfr8BitInt(uint8_t val); |
127 | ||
f21fc0aa | 128 | void xfrName(const DNSName& label, bool compress=false, bool noDot=false); |
84e1142d | 129 | void xfrText(const string& text, bool multi=false, bool lenField=true); |
948a927f | 130 | void xfrUnquotedText(const string& text, bool lenField); |
06ffdc52 | 131 | void xfrBlob(const string& blob, int len=-1); |
2fe9d6f7 | 132 | void xfrBlobNoSpaces(const string& blob, int len=-1); |
e4090157 | 133 | void xfrHexBlob(const string& blob, bool keepReading=false); |
bca6643b | 134 | |
8e97e9a3 | 135 | dnsheader* getHeader(); |
e636cab2 | 136 | void getRecordPayload(string& records); // call __before commit__ |
ea634573 | 137 | |
950cfe0f | 138 | void setCanonic(bool val) |
f3f4938f BH |
139 | { |
140 | d_canonic=val; | |
141 | } | |
142 | ||
950cfe0f | 143 | void setLowercase(bool val) |
7f5bf0ba BH |
144 | { |
145 | d_lowerCase=val; | |
146 | } | |
3f45f34d BH |
147 | vector <uint8_t>& getContent() |
148 | { | |
149 | return d_content; | |
150 | } | |
d476d7fb | 151 | bool eof() { return true; } // we don't know how long the record should be |
7f5bf0ba | 152 | |
ddb79bca AT |
153 | const string getRemaining() const { |
154 | return ""; | |
155 | } | |
a0a276c2 | 156 | private: |
802a93d0 | 157 | uint16_t lookupName(const DNSName& name, uint16_t* matchlen); |
fea4599a | 158 | vector<uint16_t> d_namepositions; |
ef2ea4bf | 159 | // We declare 1 uint_16 in the public section, these 3 align on a 8-byte boundary |
78817f22 PL |
160 | uint16_t d_sor; |
161 | uint16_t d_rollbackmarker; // start of last complete packet, for rollback | |
162 | ||
57e5f5f7 | 163 | vector <uint8_t>& d_content; |
c2f3be9d | 164 | DNSName d_qname; |
78817f22 | 165 | |
add935a2 | 166 | uint16_t d_truncatemarker; // end of header, for truncate |
e693ff5a | 167 | DNSResourceRecord::Place d_recordplace; |
02e7763f | 168 | bool d_canonic, d_lowerCase, d_compress{false}; |
a0a276c2 | 169 | }; |
213f6de6 BH |
170 | |
171 | typedef vector<pair<string::size_type, string::size_type> > labelparts_t; | |
c2f3be9d | 172 | // bool labeltokUnescape(labelparts_t& parts, const DNSName& label); |
bac8f21b | 173 | std::vector<string> segmentDNSText(const string& text); // from dnslabeltext.rl |
e8c59f2d | 174 | std::deque<string> segmentDNSName(const string& input); // from dnslabeltext.rl |