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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 | */ | |
22 | ||
23 | #include "nod.hh" | |
24 | #include <fstream> | |
25 | #include "pdnsexception.hh" | |
26 | #include <iostream> | |
27 | #include <iomanip> | |
28 | #include <ctime> | |
29 | #include <thread> | |
519f5484 | 30 | #include "threadname.hh" |
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31 | #include <unistd.h> |
32 | #include <boost/filesystem.hpp> | |
33 | #include "logger.hh" | |
34 | #include "misc.hh" | |
35 | ||
36 | using namespace nod; | |
37 | using namespace boost::filesystem; | |
38 | ||
343ae951 NC |
39 | // PersistentSBF Implementation |
40 | ||
41 | std::mutex PersistentSBF::d_cachedir_mutex; | |
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42 | |
43 | // This looks for an old (per-thread) snapshot. The first one it finds, | |
44 | // it restores from that. Then immediately snapshots with the current thread id,// before removing the old snapshot | |
45 | // In this way, we can have per-thread SBFs, but still snapshot and restore. | |
46 | // The mutex has to be static because we can't have multiple (i.e. per-thread) | |
47 | // instances iterating and writing to the cache dir at the same time | |
343ae951 | 48 | bool PersistentSBF::init(bool ignore_pid) { |
af1377b7 NC |
49 | if (d_init) |
50 | return false; | |
51 | ||
343ae951 | 52 | std::lock_guard<std::mutex> lock(d_cachedir_mutex); |
af1377b7 NC |
53 | if (d_cachedir.length()) { |
54 | path p(d_cachedir); | |
55 | try { | |
56 | if (exists(p) && is_directory(p)) { | |
57 | path newest_file; | |
58 | std::time_t newest_time=time(nullptr); | |
343ae951 | 59 | Regex file_regex(d_prefix + ".*\\." + bf_suffix + "$"); |
af1377b7 NC |
60 | for (directory_iterator i(p); i!=directory_iterator(); ++i) { |
61 | if (is_regular_file(i->path()) && | |
62 | file_regex.match(i->path().filename().string())) { | |
63 | if (ignore_pid || | |
64 | (i->path().filename().string().find(std::to_string(getpid())) == std::string::npos)) { | |
65 | // look for the newest file matching the regex | |
66 | if ((last_write_time(i->path()) < newest_time) || | |
67 | newest_file.empty()) { | |
68 | newest_time = last_write_time(i->path()); | |
69 | newest_file = i->path(); | |
70 | } | |
71 | } | |
72 | } | |
73 | } | |
74 | if (exists(newest_file)) { | |
75 | std::string filename = newest_file.string(); | |
76 | std::ifstream infile; | |
77 | try { | |
78 | infile.open(filename, std::ios::in | std::ios::binary); | |
79 | g_log << Logger::Warning << "Found SBF file " << filename << endl; | |
80 | // read the file into the sbf | |
81 | d_sbf.restore(infile); | |
82 | infile.close(); | |
83 | // now dump it out again with new thread id & process id | |
343ae951 | 84 | snapshotCurrent(std::this_thread::get_id()); |
af1377b7 NC |
85 | // Remove the old file we just read to stop proliferation |
86 | remove(newest_file); | |
87 | } | |
88 | catch (const std::runtime_error& e) { | |
89 | g_log<<Logger::Warning<<"NODDB init: Cannot parse file: " << filename << endl; | |
90 | } | |
91 | } | |
92 | } | |
93 | } | |
94 | catch (const filesystem_error& e) { | |
95 | g_log<<Logger::Warning<<"NODDB init failed:: " << e.what() << endl; | |
96 | return false; | |
97 | } | |
98 | } | |
99 | d_init = true; | |
100 | return true; | |
101 | } | |
102 | ||
343ae951 | 103 | void PersistentSBF::setCacheDir(const std::string& cachedir) |
af1377b7 NC |
104 | { |
105 | if (!d_init) { | |
106 | path p(cachedir); | |
107 | if (!exists(p)) | |
108 | throw PDNSException("NODDB setCacheDir specified non-existent directory: " + cachedir); | |
109 | else if (!is_directory(p)) | |
110 | throw PDNSException("NODDB setCacheDir specified a file not a directory: " + cachedir); | |
111 | d_cachedir = cachedir; | |
112 | } | |
113 | } | |
114 | ||
343ae951 NC |
115 | // Dump the SBF to a file |
116 | // To spend the least amount of time inside the mutex, we dump to an | |
117 | // intermediate stringstream, otherwise the lock would be waiting for | |
118 | // file IO to complete | |
119 | bool PersistentSBF::snapshotCurrent(std::thread::id tid) | |
120 | { | |
121 | if (d_cachedir.length()) { | |
122 | path p(d_cachedir); | |
123 | path f(d_cachedir); | |
124 | std::stringstream ss; | |
125 | ss << d_prefix << "_" << tid; | |
126 | f /= ss.str() + "_" + std::to_string(getpid()) + "." + bf_suffix; | |
127 | if (exists(p) && is_directory(p)) { | |
128 | try { | |
129 | std::ofstream ofile; | |
130 | std::stringstream ss; | |
131 | ofile.open(f.string(), std::ios::out | std::ios::binary); | |
132 | { | |
133 | // only lock while dumping to a stringstream | |
134 | std::lock_guard<std::mutex> lock(d_sbf_mutex); | |
135 | d_sbf.dump(ss); | |
136 | } | |
137 | // Now write it out to the file | |
138 | ofile << ss.str(); | |
139 | ||
140 | if (ofile.fail()) | |
141 | throw std::runtime_error("Failed to write to file:" + f.string()); | |
142 | return true; | |
143 | } | |
144 | catch (const std::runtime_error& e) { | |
145 | g_log<<Logger::Warning<<"NODDB snapshot: Cannot write file: " << e.what() << endl; | |
146 | } | |
147 | } | |
148 | else { | |
149 | g_log<<Logger::Warning<<"NODDB snapshot: Cannot write file: " << f.string() << endl; | |
150 | } | |
151 | } | |
152 | return false; | |
153 | } | |
154 | ||
155 | // NODDB Implementation | |
156 | ||
157 | void NODDB::housekeepingThread(std::thread::id tid) | |
158 | { | |
159 | setThreadName("pdns-r/NOD-hk"); | |
160 | for (;;) { | |
161 | sleep(d_snapshot_interval); | |
162 | { | |
163 | snapshotCurrent(tid); | |
164 | } | |
165 | } | |
166 | } | |
167 | ||
af1377b7 NC |
168 | bool NODDB::isNewDomain(const std::string& domain) |
169 | { | |
170 | DNSName dname(domain); | |
171 | return isNewDomain(dname); | |
172 | } | |
173 | ||
174 | bool NODDB::isNewDomain(const DNSName& dname) | |
175 | { | |
176 | std::string dname_lc = dname.toDNSStringLC(); | |
177 | // The only time this should block is when snapshotting from the | |
178 | // housekeeping thread | |
af1377b7 | 179 | // the result is always the inverse of what is returned by the SBF |
343ae951 | 180 | return !d_psbf.testAndAdd(dname_lc); |
af1377b7 NC |
181 | } |
182 | ||
183 | bool NODDB::isNewDomainWithParent(const std::string& domain, std::string& observed) | |
184 | { | |
185 | DNSName dname(domain); | |
186 | return isNewDomainWithParent(dname, observed); | |
187 | } | |
188 | ||
189 | bool NODDB::isNewDomainWithParent(const DNSName& dname, std::string& observed) | |
190 | { | |
191 | bool ret = isNewDomain(dname); | |
192 | if (ret == true) { | |
193 | DNSName mdname = dname; | |
194 | while (mdname.chopOff()) { | |
195 | if (!isNewDomain(mdname)) { | |
196 | observed = mdname.toString(); | |
197 | break; | |
198 | } | |
199 | } | |
200 | } | |
201 | return ret; | |
202 | } | |
203 | ||
204 | void NODDB::addDomain(const DNSName& dname) | |
205 | { | |
af1377b7 | 206 | std::string native_domain = dname.toDNSStringLC(); |
343ae951 | 207 | d_psbf.add(native_domain); |
af1377b7 NC |
208 | } |
209 | ||
210 | void NODDB::addDomain(const std::string& domain) | |
211 | { | |
212 | DNSName dname(domain); | |
213 | addDomain(dname); | |
214 | } | |
215 | ||
343ae951 NC |
216 | // UniqueResponseDB Implementation |
217 | bool UniqueResponseDB::isUniqueResponse(const std::string& response) | |
af1377b7 | 218 | { |
343ae951 NC |
219 | return !d_psbf.testAndAdd(response); |
220 | } | |
af1377b7 | 221 | |
343ae951 NC |
222 | void UniqueResponseDB::addResponse(const std::string& response) |
223 | { | |
224 | d_psbf.add(response); | |
225 | } | |
226 | ||
227 | void UniqueResponseDB::housekeepingThread(std::thread::id tid) | |
228 | { | |
229 | setThreadName("pdns-r/UDR-hk"); | |
230 | for (;;) { | |
231 | sleep(d_snapshot_interval); | |
232 | { | |
233 | snapshotCurrent(tid); | |
af1377b7 NC |
234 | } |
235 | } | |
af1377b7 | 236 | } |