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e14f094b BH |
1 | /* |
2 | PowerDNS Versatile Database Driven Nameserver | |
e125fc69 | 3 | Copyright (C) 2002 - 2014 PowerDNS.COM BV |
e14f094b BH |
4 | |
5 | This program is free software; you can redistribute it and/or modify | |
d0166f4a BH |
6 | it under the terms of the GNU General Public License version 2 as |
7 | published by the Free Software Foundation | |
e14f094b | 8 | |
f782fe38 MH |
9 | Additionally, the license of this program contains a special |
10 | exception which allows to distribute the program in binary form when | |
11 | it is linked against OpenSSL. | |
12 | ||
e14f094b BH |
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 | |
06bd9ccf | 20 | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
e14f094b | 21 | */ |
705f31ae BH |
22 | |
23 | ||
870a0fe4 AT |
24 | #ifdef HAVE_CONFIG_H |
25 | #include "config.h" | |
26 | #endif | |
36c5ee42 | 27 | #include "utility.hh" |
e14f094b | 28 | #include "lwres.hh" |
e14f094b | 29 | #include <iostream> |
81883dcc | 30 | #include "dnsrecords.hh" |
e14f094b BH |
31 | #include <errno.h> |
32 | #include "misc.hh" | |
33 | #include <algorithm> | |
34 | #include <sstream> | |
35 | #include <cstring> | |
36 | #include <string> | |
37 | #include <vector> | |
e14f094b BH |
38 | #include "dns.hh" |
39 | #include "qtype.hh" | |
5c409fa2 | 40 | #include "pdnsexception.hh" |
e14f094b | 41 | #include "arguments.hh" |
5c633640 BH |
42 | #include "sstuff.hh" |
43 | #include "syncres.hh" | |
ea634573 BH |
44 | #include "dnswriter.hh" |
45 | #include "dnsparser.hh" | |
aab4adb0 | 46 | #include "logger.hh" |
51e2144e | 47 | #include "dns_random.hh" |
263f6a5a | 48 | #include <boost/scoped_array.hpp> |
51e2144e BH |
49 | #include <boost/algorithm/string.hpp> |
50 | ||
81883dcc BH |
51 | //! returns -2 for OS limits error, -1 for permanent error that has to do with remote **transport**, 0 for timeout, 1 for success |
52 | /** lwr is only filled out in case 1 was returned, and even when returning 1 for 'success', lwr might contain DNS errors | |
53 | Never throws! | |
54 | */ | |
6893459d | 55 | int asyncresolve(const ComboAddress& ip, const string& domain, int type, bool doTCP, bool sendRDQuery, int EDNS0Level, struct timeval* now, LWResult *lwr) |
e14f094b | 56 | { |
263f6a5a BH |
57 | int len; |
58 | int bufsize=1500; | |
59 | scoped_array<unsigned char> buf(new unsigned char[bufsize]); | |
ea634573 | 60 | vector<uint8_t> vpacket; |
51e2144e | 61 | // string mapped0x20=dns0x20(domain); |
ea634573 BH |
62 | DNSPacketWriter pw(vpacket, domain, type); |
63 | ||
c1d73d94 | 64 | pw.getHeader()->rd=sendRDQuery; |
51e2144e | 65 | pw.getHeader()->id=dns_random(0xffff); |
81883dcc BH |
66 | |
67 | string ping; | |
68 | ||
81883dcc BH |
69 | if(EDNS0Level && !doTCP) { |
70 | DNSPacketWriter::optvect_t opts; | |
71 | if(EDNS0Level > 1) { | |
93d4a890 | 72 | uint32_t nonce=dns_random(0xffffffff); |
73 | ping.assign((char*) &nonce, 4); | |
74 | ||
81883dcc BH |
75 | opts.push_back(make_pair(5, ping)); |
76 | } | |
2188dcc3 | 77 | |
81883dcc | 78 | pw.addOpt(1200, 0, 0, opts); // 1200 bytes answer size |
2188dcc3 BH |
79 | pw.commit(); |
80 | } | |
81883dcc BH |
81 | lwr->d_rcode = 0; |
82 | lwr->d_pingCorrect = false; | |
83 | lwr->d_haveEDNS = false; | |
eefd15f9 BH |
84 | int ret; |
85 | ||
86 | DTime dt; | |
4c4765c1 | 87 | dt.set(); |
88 | *now=dt.getTimeval(); | |
263f6a5a | 89 | errno=0; |
5c633640 | 90 | if(!doTCP) { |
4ef015cd | 91 | int queryfd; |
996c89cc BH |
92 | if(ip.sin4.sin_family==AF_INET6) |
93 | g_stats.ipv6queries++; | |
94 | ||
787e5eab | 95 | if((ret=asendto((const char*)&*vpacket.begin(), (int)vpacket.size(), 0, ip, pw.getHeader()->id, |
232f0877 | 96 | domain, type, &queryfd)) < 0) { |
998a4334 | 97 | return ret; // passes back the -2 EMFILE |
5c633640 BH |
98 | } |
99 | ||
100 | // sleep until we see an answer to this, interface to mtasker | |
101 | ||
263f6a5a | 102 | ret=arecvfrom(reinterpret_cast<char *>(buf.get()), bufsize-1,0, ip, &len, pw.getHeader()->id, |
232f0877 | 103 | domain, type, queryfd, now); |
e14f094b | 104 | } |
5c633640 | 105 | else { |
998a4334 | 106 | try { |
93f4e5ce | 107 | Socket s(ip.sin4.sin_family, SOCK_STREAM); |
fdf05fd4 | 108 | |
998a4334 | 109 | s.setNonBlocking(); |
1652a63e | 110 | ComboAddress local = getQueryLocalAddress(ip.sin4.sin_family, 0); |
3ac2a2ab | 111 | |
5a38281c | 112 | s.bind(local); |
4957a608 | 113 | |
fdf05fd4 BH |
114 | ComboAddress remote = ip; |
115 | remote.sin4.sin_port = htons(53); | |
116 | s.connect(remote); | |
998a4334 | 117 | |
263f6a5a BH |
118 | uint16_t tlen=htons(vpacket.size()); |
119 | char *lenP=(char*)&tlen; | |
998a4334 BH |
120 | const char *msgP=(const char*)&*vpacket.begin(); |
121 | string packet=string(lenP, lenP+2)+string(msgP, msgP+vpacket.size()); | |
122 | ||
123 | ret=asendtcp(packet, &s); | |
124 | if(!(ret>0)) | |
4957a608 | 125 | return ret; |
998a4334 BH |
126 | |
127 | packet.clear(); | |
825fa717 | 128 | ret=arecvtcp(packet, 2, &s, false); |
998a4334 | 129 | if(!(ret > 0)) |
4957a608 | 130 | return ret; |
998a4334 | 131 | |
263f6a5a BH |
132 | memcpy(&tlen, packet.c_str(), 2); |
133 | len=ntohs(tlen); // switch to the 'len' shared with the rest of the function | |
998a4334 | 134 | |
825fa717 | 135 | ret=arecvtcp(packet, len, &s, false); |
998a4334 | 136 | if(!(ret > 0)) |
4957a608 | 137 | return ret; |
998a4334 | 138 | |
263f6a5a | 139 | if(len > bufsize) { |
4957a608 BH |
140 | bufsize=len; |
141 | scoped_array<unsigned char> narray(new unsigned char[bufsize]); | |
142 | buf.swap(narray); | |
998a4334 | 143 | } |
263f6a5a BH |
144 | memcpy(buf.get(), packet.c_str(), len); |
145 | ||
998a4334 BH |
146 | ret=1; |
147 | } | |
148 | catch(NetworkError& ne) { | |
149 | ret = -2; // OS limits error | |
66ab6a63 | 150 | } |
5c633640 | 151 | } |
998a4334 | 152 | |
81883dcc | 153 | |
26de3092 BH |
154 | lwr->d_usec=dt.udiff(); |
155 | *now=dt.getTimeval(); | |
156 | ||
263f6a5a BH |
157 | if(ret <= 0) // includes 'timeout' |
158 | return ret; | |
e14f094b | 159 | |
263f6a5a | 160 | lwr->d_result.clear(); |
c836dc19 | 161 | try { |
f1f85f12 | 162 | lwr->d_tcbit=0; |
263f6a5a BH |
163 | MOADNSParser mdp((const char*)buf.get(), len); |
164 | lwr->d_aabit=mdp.d_header.aa; | |
165 | lwr->d_tcbit=mdp.d_header.tc; | |
166 | lwr->d_rcode=mdp.d_header.rcode; | |
167 | ||
81883dcc BH |
168 | if(mdp.d_header.rcode == RCode::FormErr && mdp.d_qname.empty() && mdp.d_qtype == 0 && mdp.d_qclass == 0) { |
169 | return 1; // this is "success", the error is set in lwr->d_rcode | |
170 | } | |
171 | ||
ec6480f3 | 172 | if(!pdns_iequals(domain, mdp.d_qname)) { |
673c5f31 | 173 | if(!mdp.d_qname.empty() && domain.find((char)0) == string::npos) {// embedded nulls are too noisy, plus empty domains are too |
4957a608 | 174 | L<<Logger::Notice<<"Packet purporting to come from remote server "<<ip.toString()<<" contained wrong answer: '" << domain << "' != '" << mdp.d_qname << "'" << endl; |
01608dca | 175 | } |
284aa5c2 | 176 | // unexpected count has already been done @ pdns_recursor.cc |
2353fffa BH |
177 | goto out; |
178 | } | |
51e2144e | 179 | |
ea634573 | 180 | for(MOADNSParser::answers_t::const_iterator i=mdp.d_answers.begin(); i!=mdp.d_answers.end(); ++i) { |
ea634573 BH |
181 | DNSResourceRecord rr; |
182 | rr.qtype=i->first.d_type; | |
183 | rr.qname=i->first.d_label; | |
184 | rr.ttl=i->first.d_ttl; | |
185 | rr.content=i->first.d_content->getZoneRepresentation(); // this should be the serialised form | |
ea634573 | 186 | rr.d_place=(DNSResourceRecord::Place) i->first.d_place; |
263f6a5a | 187 | lwr->d_result.push_back(rr); |
ea634573 | 188 | } |
81883dcc BH |
189 | |
190 | EDNSOpts edo; | |
191 | if(EDNS0Level > 1 && getEDNSOpts(mdp, &edo)) { | |
192 | lwr->d_haveEDNS = true; | |
193 | for(vector<pair<uint16_t, string> >::const_iterator iter = edo.d_options.begin(); | |
4957a608 BH |
194 | iter != edo.d_options.end(); |
195 | ++iter) { | |
196 | if(iter->first == 5 || iter->first == 4) {// 'EDNS PING' | |
197 | if(iter->second == ping) { | |
198 | lwr->d_pingCorrect = true; | |
199 | } | |
200 | } | |
81883dcc BH |
201 | } |
202 | } | |
203 | ||
263f6a5a | 204 | return 1; |
c836dc19 | 205 | } |
fdbf35ac | 206 | catch(std::exception &mde) { |
aab4adb0 | 207 | if(::arg().mustDo("log-common-errors")) |
263f6a5a | 208 | L<<Logger::Notice<<"Unable to parse packet from remote server "<<ip.toString()<<": "<<mde.what()<<endl; |
81883dcc BH |
209 | lwr->d_rcode = RCode::FormErr; |
210 | g_stats.serverParseError++; | |
211 | return 1; // success - oddly enough | |
aab4adb0 | 212 | } |
c836dc19 | 213 | catch(...) { |
ad1bb608 | 214 | L<<Logger::Notice<<"Unknown error parsing packet from remote server"<<endl; |
c836dc19 | 215 | } |
263f6a5a | 216 | |
aab4adb0 | 217 | g_stats.serverParseError++; |
263f6a5a | 218 | |
2353fffa | 219 | out: |
81883dcc BH |
220 | if(!lwr->d_rcode) |
221 | lwr->d_rcode=RCode::ServFail; | |
263f6a5a BH |
222 | |
223 | return -1; | |
e14f094b BH |
224 | } |
225 | ||
263f6a5a | 226 |