pdns/misc.cc

   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 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25 #include <sys/param.h>
  26 #include <sys/socket.h>
  27 #include <fcntl.h>
  28 #include <netdb.h>
  29 #include <sys/time.h>
  30 #include <time.h>
  31 #include <sys/resource.h>
  32 #include <netinet/in.h>
  33 #include <sys/un.h>
  34 #include <unistd.h>
  35 #include <fstream>
  36 #include "misc.hh"
  37 #include <vector>
  38 #include <sstream>
  39 #include <errno.h>
  40 #include <cstring>
  41 #include <iostream>
  42 #include <sys/types.h>
  43 #include <dirent.h>
  44 #include <algorithm>
  45 #include <boost/optional.hpp>
  46 #include <poll.h>
  47 #include <iomanip>
  48 #include <netinet/tcp.h>
  49 #include <string.h>
  50 #include <stdlib.h>
  51 #include <stdio.h>
  52 #include "pdnsexception.hh"
  53 #include <sys/types.h>
  54 #include <boost/algorithm/string.hpp>
  55 #include "iputils.hh"
  56 #include "dnsparser.hh"
  57 #include <sys/types.h>
  58 #include <pwd.h>
  59 #include <grp.h>
  60 #ifdef __FreeBSD__
  61 #  include <pthread_np.h>
  62 #endif
  63 #ifdef __NetBSD__
  64 #  include <pthread.h>
  65 #  include <sched.h>
  66 #endif
  67
  68 size_t writen2(int fd, const void *buf, size_t count)
  69 {
  70   const char *ptr = (char*)buf;
  71   const char *eptr = ptr + count;
  72
  73   ssize_t res;
  74   while(ptr != eptr) {
  75     res = ::write(fd, ptr, eptr - ptr);
  76     if(res < 0) {
  77       if (errno == EAGAIN)
  78         throw std::runtime_error("used writen2 on non-blocking socket, got EAGAIN");
  79       else
  80         unixDie("failed in writen2");
  81     }
  82     else if (res == 0)
  83       throw std::runtime_error("could not write all bytes, got eof in writen2");
  84
  85     ptr += (size_t) res;
  86   }
  87
  88   return count;
  89 }
  90
  91 size_t readn2(int fd, void* buffer, size_t len)
  92 {
  93   size_t pos=0;
  94   ssize_t res;
  95   for(;;) {
  96     res = read(fd, (char*)buffer + pos, len - pos);
  97     if(res == 0)
  98       throw runtime_error("EOF while reading message");
  99     if(res < 0) {
 100       if (errno == EAGAIN)
 101         throw std::runtime_error("used readn2 on non-blocking socket, got EAGAIN");
 102       else
 103         unixDie("failed in readn2");
 104     }
 105
 106     pos+=(size_t)res;
 107     if(pos == len)
 108       break;
 109   }
 110   return len;
 111 }
 112
 113 size_t readn2WithTimeout(int fd, void* buffer, size_t len, int idleTimeout, int totalTimeout)
 114 {
 115   size_t pos = 0;
 116   time_t start = 0;
 117   int remainingTime = totalTimeout;
 118   if (totalTimeout) {
 119     start = time(NULL);
 120   }
 121
 122   do {
 123     ssize_t got = read(fd, (char *)buffer + pos, len - pos);
 124     if (got > 0) {
 125       pos += (size_t) got;
 126     }
 127     else if (got == 0) {
 128       throw runtime_error("EOF while reading message");
 129     }
 130     else {
 131       if (errno == EAGAIN) {
 132         int res = waitForData(fd, (totalTimeout == 0 || idleTimeout <= remainingTime) ? idleTimeout : remainingTime);
 133         if (res > 0) {
 134           /* there is data available */
 135         }
 136         else if (res == 0) {
 137           throw runtime_error("Timeout while waiting for data to read");
 138         } else {
 139           throw runtime_error("Error while waiting for data to read");
 140         }
 141       }
 142       else {
 143         unixDie("failed in readn2WithTimeout");
 144       }
 145     }
 146
 147     if (totalTimeout) {
 148       time_t now = time(NULL);
 149       int elapsed = now - start;
 150       if (elapsed >= remainingTime) {
 151         throw runtime_error("Timeout while reading data");
 152       }
 153       start = now;
 154       remainingTime -= elapsed;
 155     }
 156   }
 157   while (pos < len);
 158
 159   return len;
 160 }
 161
 162 size_t writen2WithTimeout(int fd, const void * buffer, size_t len, int timeout)
 163 {
 164   size_t pos = 0;
 165   do {
 166     ssize_t written = write(fd, (char *)buffer + pos, len - pos);
 167
 168     if (written > 0) {
 169       pos += (size_t) written;
 170     }
 171     else if (written == 0)
 172       throw runtime_error("EOF while writing message");
 173     else {
 174       if (errno == EAGAIN) {
 175         int res = waitForRWData(fd, false, timeout, 0);
 176         if (res > 0) {
 177           /* there is room available */
 178         }
 179         else if (res == 0) {
 180           throw runtime_error("Timeout while waiting to write data");
 181         } else {
 182           throw runtime_error("Error while waiting for room to write data");
 183         }
 184       }
 185       else {
 186         unixDie("failed in write2WithTimeout");
 187       }
 188     }
 189   }
 190   while (pos < len);
 191
 192   return len;
 193 }
 194
 195 string nowTime()
 196 {
 197   time_t now = time(nullptr);
 198   struct tm tm;
 199   localtime_r(&now, &tm);
 200   char buffer[30];
 201   // YYYY-mm-dd HH:MM:SS TZOFF
 202   strftime(buffer, sizeof(buffer), "%F %T %z", &tm);
 203   buffer[sizeof(buffer)-1] = '\0';
 204   return string(buffer);
 205 }
 206
 207 uint16_t getShort(const unsigned char *p)
 208 {
 209   return p[0] * 256 + p[1];
 210 }
 211
 212
 213 uint16_t getShort(const char *p)
 214 {
 215   return getShort((const unsigned char *)p);
 216 }
 217
 218 uint32_t getLong(const unsigned char* p)
 219 {
 220   return (p[0]<<24) + (p[1]<<16) + (p[2]<<8) + p[3];
 221 }
 222
 223 uint32_t getLong(const char* p)
 224 {
 225   return getLong((unsigned char *)p);
 226 }
 227
 228 static bool ciEqual(const string& a, const string& b)
 229 {
 230   if(a.size()!=b.size())
 231     return false;
 232
 233   string::size_type pos=0, epos=a.size();
 234   for(;pos < epos; ++pos)
 235     if(dns_tolower(a[pos])!=dns_tolower(b[pos]))
 236       return false;
 237   return true;
 238 }
 239
 240 /** does domain end on suffix? Is smart about "wwwds9a.nl" "ds9a.nl" not matching */
 241 static bool endsOn(const string &domain, const string &suffix)
 242 {
 243   if( suffix.empty() || ciEqual(domain, suffix) )
 244     return true;
 245
 246   if(domain.size()<=suffix.size())
 247     return false;
 248
 249   string::size_type dpos=domain.size()-suffix.size()-1, spos=0;
 250
 251   if(domain[dpos++]!='.')
 252     return false;
 253
 254   for(; dpos < domain.size(); ++dpos, ++spos)
 255     if(dns_tolower(domain[dpos]) != dns_tolower(suffix[spos]))
 256       return false;
 257
 258   return true;
 259 }
 260
 261 /** strips a domain suffix from a domain, returns true if it stripped */
 262 bool stripDomainSuffix(string *qname, const string &domain)
 263 {
 264   if(!endsOn(*qname, domain))
 265     return false;
 266
 267   if(toLower(*qname)==toLower(domain))
 268     *qname="@";
 269   else {
 270     if((*qname)[qname->size()-domain.size()-1]!='.')
 271       return false;
 272
 273     qname->resize(qname->size()-domain.size()-1);
 274   }
 275   return true;
 276 }
 277
 278 static void parseService4(const string &descr, ServiceTuple &st)
 279 {
 280   vector<string>parts;
 281   stringtok(parts,descr,":");
 282   if(parts.empty())
 283     throw PDNSException("Unable to parse '"+descr+"' as a service");
 284   st.host=parts[0];
 285   if(parts.size()>1)
 286     st.port=pdns_stou(parts[1]);
 287 }
 288
 289 static void parseService6(const string &descr, ServiceTuple &st)
 290 {
 291   string::size_type pos=descr.find(']');
 292   if(pos == string::npos)
 293     throw PDNSException("Unable to parse '"+descr+"' as an IPv6 service");
 294
 295   st.host=descr.substr(1, pos-1);
 296   if(pos + 2 < descr.length())
 297     st.port=pdns_stou(descr.substr(pos+2));
 298 }
 299
 300
 301 void parseService(const string &descr, ServiceTuple &st)
 302 {
 303   if(descr.empty())
 304     throw PDNSException("Unable to parse '"+descr+"' as a service");
 305
 306   vector<string> parts;
 307   stringtok(parts, descr, ":");
 308
 309   if(descr[0]=='[') {
 310     parseService6(descr, st);
 311   }
 312   else if(descr[0]==':' || parts.size() > 2 || descr.find("::") != string::npos) {
 313     st.host=descr;
 314   }
 315   else {
 316     parseService4(descr, st);
 317   }
 318 }
 319
 320 // returns -1 in case if error, 0 if no data is available, 1 if there is. In the first two cases, errno is set
 321 int waitForData(int fd, int seconds, int useconds)
 322 {
 323   return waitForRWData(fd, true, seconds, useconds);
 324 }
 325
 326 int waitForRWData(int fd, bool waitForRead, int seconds, int useconds, bool* error, bool* disconnected)
 327 {
 328   int ret;
 329
 330   struct pollfd pfd;
 331   memset(&pfd, 0, sizeof(pfd));
 332   pfd.fd = fd;
 333
 334   if(waitForRead)
 335     pfd.events=POLLIN;
 336   else
 337     pfd.events=POLLOUT;
 338
 339   ret = poll(&pfd, 1, seconds * 1000 + useconds/1000);
 340   if (ret > 0) {
 341     if (error && (pfd.revents & POLLERR)) {
 342       *error = true;
 343     }
 344     if (disconnected && (pfd.revents & POLLHUP)) {
 345       *disconnected = true;
 346     }
 347   }
 348
 349   return ret;
 350 }
 351
 352 // returns -1 in case of error, 0 if no data is available, 1 if there is. In the first two cases, errno is set
 353 int waitForMultiData(const set<int>& fds, const int seconds, const int useconds, int* fdOut) {
 354   set<int> realFDs;
 355   for (const auto& fd : fds) {
 356     if (fd >= 0 && realFDs.count(fd) == 0) {
 357       realFDs.insert(fd);
 358     }
 359   }
 360
 361   std::vector<struct pollfd> pfds(realFDs.size());
 362   memset(pfds.data(), 0, realFDs.size()*sizeof(struct pollfd));
 363   int ctr = 0;
 364   for (const auto& fd : realFDs) {
 365     pfds[ctr].fd = fd;
 366     pfds[ctr].events = POLLIN;
 367     ctr++;
 368   }
 369
 370   int ret;
 371   if(seconds >= 0)
 372     ret = poll(pfds.data(), realFDs.size(), seconds * 1000 + useconds/1000);
 373   else
 374     ret = poll(pfds.data(), realFDs.size(), -1);
 375   if(ret <= 0)
 376     return ret;
 377
 378   set<int> pollinFDs;
 379   for (const auto& pfd : pfds) {
 380     if (pfd.revents & POLLIN) {
 381       pollinFDs.insert(pfd.fd);
 382     }
 383   }
 384   set<int>::const_iterator it(pollinFDs.begin());
 385   advance(it, random() % pollinFDs.size());
 386   *fdOut = *it;
 387   return 1;
 388 }
 389
 390 // returns -1 in case of error, 0 if no data is available, 1 if there is. In the first two cases, errno is set
 391 int waitFor2Data(int fd1, int fd2, int seconds, int useconds, int*fd)
 392 {
 393   int ret;
 394
 395   struct pollfd pfds[2];
 396   memset(&pfds[0], 0, 2*sizeof(struct pollfd));
 397   pfds[0].fd = fd1;
 398   pfds[1].fd = fd2;
 399
 400   pfds[0].events= pfds[1].events = POLLIN;
 401
 402   int nsocks = 1 + (fd2 >= 0); // fd2 can optionally be -1
 403
 404   if(seconds >= 0)
 405     ret = poll(pfds, nsocks, seconds * 1000 + useconds/1000);
 406   else
 407     ret = poll(pfds, nsocks, -1);
 408   if(!ret || ret < 0)
 409     return ret;
 410
 411   if((pfds[0].revents & POLLIN) && !(pfds[1].revents & POLLIN))
 412     *fd = pfds[0].fd;
 413   else if((pfds[1].revents & POLLIN) && !(pfds[0].revents & POLLIN))
 414     *fd = pfds[1].fd;
 415   else if(ret == 2) {
 416     *fd = pfds[random()%2].fd;
 417   }
 418   else
 419     *fd = -1; // should never happen
 420
 421   return 1;
 422 }
 423
 424
 425 string humanDuration(time_t passed)
 426 {
 427   ostringstream ret;
 428   if(passed<60)
 429     ret<<passed<<" seconds";
 430   else if(passed<3600)
 431     ret<<std::setprecision(2)<<passed/60.0<<" minutes";
 432   else if(passed<86400)
 433     ret<<std::setprecision(3)<<passed/3600.0<<" hours";
 434   else if(passed<(86400*30.41))
 435     ret<<std::setprecision(3)<<passed/86400.0<<" days";
 436   else
 437     ret<<std::setprecision(3)<<passed/(86400*30.41)<<" months";
 438
 439   return ret.str();
 440 }
 441
 442 DTime::DTime()
 443 {
 444 //  set(); // saves lots of gettimeofday calls
 445   d_set.tv_sec=d_set.tv_usec=0;
 446 }
 447
 448 time_t DTime::time()
 449 {
 450   return d_set.tv_sec;
 451 }
 452
 453 const string unquotify(const string &item)
 454 {
 455   if(item.size()<2)
 456     return item;
 457
 458   string::size_type bpos=0, epos=item.size();
 459
 460   if(item[0]=='"')
 461     bpos=1;
 462
 463   if(item[epos-1]=='"')
 464     epos-=1;
 465
 466   return item.substr(bpos,epos-bpos);
 467 }
 468
 469 void stripLine(string &line)
 470 {
 471   string::size_type pos=line.find_first_of("\r\n");
 472   if(pos!=string::npos) {
 473     line.resize(pos);
 474   }
 475 }
 476
 477 string urlEncode(const string &text)
 478 {
 479   string ret;
 480   for(string::const_iterator i=text.begin();i!=text.end();++i)
 481     if(*i==' ')ret.append("%20");
 482     else ret.append(1,*i);
 483   return ret;
 484 }
 485
 486 string getHostname()
 487 {
 488 #ifndef MAXHOSTNAMELEN
 489 #define MAXHOSTNAMELEN 255
 490 #endif
 491
 492   char tmp[MAXHOSTNAMELEN];
 493   if(gethostname(tmp, MAXHOSTNAMELEN))
 494     return "UNKNOWN";
 495
 496   return string(tmp);
 497 }
 498
 499 string itoa(int i)
 500 {
 501   ostringstream o;
 502   o<<i;
 503   return o.str();
 504 }
 505
 506 string uitoa(unsigned int i) // MSVC 6 doesn't grok overloading (un)signed
 507 {
 508   ostringstream o;
 509   o<<i;
 510   return o.str();
 511 }
 512
 513 string bitFlip(const string &str)
 514 {
 515   string::size_type pos=0, epos=str.size();
 516   string ret;
 517   ret.reserve(epos);
 518   for(;pos < epos; ++pos)
 519     ret.append(1, ~str[pos]);
 520   return ret;
 521 }
 522
 523 string stringerror(int err)
 524 {
 525   return strerror(err);
 526 }
 527
 528 string stringerror()
 529 {
 530   return strerror(errno);
 531 }
 532
 533 void cleanSlashes(string &str)
 534 {
 535   string::const_iterator i;
 536   string out;
 537   for(i=str.begin();i!=str.end();++i) {
 538     if(*i=='/' && i!=str.begin() && *(i-1)=='/')
 539       continue;
 540     out.append(1,*i);
 541   }
 542   str=out;
 543 }
 544
 545
 546 bool IpToU32(const string &str, uint32_t *ip)
 547 {
 548   if(str.empty()) {
 549     *ip=0;
 550     return true;
 551   }
 552
 553   struct in_addr inp;
 554   if(inet_aton(str.c_str(), &inp)) {
 555     *ip=inp.s_addr;
 556     return true;
 557   }
 558   return false;
 559 }
 560
 561 string U32ToIP(uint32_t val)
 562 {
 563   char tmp[17];
 564   snprintf(tmp, sizeof(tmp), "%u.%u.%u.%u",
 565            (val >> 24)&0xff,
 566            (val >> 16)&0xff,
 567            (val >>  8)&0xff,
 568            (val      )&0xff);
 569   return string(tmp);
 570 }
 571
 572
 573 string makeHexDump(const string& str)
 574 {
 575   char tmp[5];
 576   string ret;
 577   ret.reserve((int)(str.size()*2.2));
 578
 579   for(string::size_type n=0;n<str.size();++n) {
 580     snprintf(tmp, sizeof(tmp), "%02x ", (unsigned char)str[n]);
 581     ret+=tmp;
 582   }
 583   return ret;
 584 }
 585
 586 void normalizeTV(struct timeval& tv)
 587 {
 588   if(tv.tv_usec > 1000000) {
 589     ++tv.tv_sec;
 590     tv.tv_usec-=1000000;
 591   }
 592   else if(tv.tv_usec < 0) {
 593     --tv.tv_sec;
 594     tv.tv_usec+=1000000;
 595   }
 596 }
 597
 598 const struct timeval operator+(const struct timeval& lhs, const struct timeval& rhs)
 599 {
 600   struct timeval ret;
 601   ret.tv_sec=lhs.tv_sec + rhs.tv_sec;
 602   ret.tv_usec=lhs.tv_usec + rhs.tv_usec;
 603   normalizeTV(ret);
 604   return ret;
 605 }
 606
 607 const struct timeval operator-(const struct timeval& lhs, const struct timeval& rhs)
 608 {
 609   struct timeval ret;
 610   ret.tv_sec=lhs.tv_sec - rhs.tv_sec;
 611   ret.tv_usec=lhs.tv_usec - rhs.tv_usec;
 612   normalizeTV(ret);
 613   return ret;
 614 }
 615
 616 pair<string, string> splitField(const string& inp, char sepa)
 617 {
 618   pair<string, string> ret;
 619   string::size_type cpos=inp.find(sepa);
 620   if(cpos==string::npos)
 621     ret.first=inp;
 622   else {
 623     ret.first=inp.substr(0, cpos);
 624     ret.second=inp.substr(cpos+1);
 625   }
 626   return ret;
 627 }
 628
 629 int logFacilityToLOG(unsigned int facility)
 630 {
 631   switch(facility) {
 632   case 0:
 633     return LOG_LOCAL0;
 634   case 1:
 635     return(LOG_LOCAL1);
 636   case 2:
 637     return(LOG_LOCAL2);
 638   case 3:
 639     return(LOG_LOCAL3);
 640   case 4:
 641     return(LOG_LOCAL4);
 642   case 5:
 643     return(LOG_LOCAL5);
 644   case 6:
 645     return(LOG_LOCAL6);
 646   case 7:
 647     return(LOG_LOCAL7);
 648   default:
 649     return -1;
 650   }
 651 }
 652
 653 string stripDot(const string& dom)
 654 {
 655   if(dom.empty())
 656     return dom;
 657
 658   if(dom[dom.size()-1]!='.')
 659     return dom;
 660
 661   return dom.substr(0,dom.size()-1);
 662 }
 663
 664
 665
 666 int makeIPv6sockaddr(const std::string& addr, struct sockaddr_in6* ret)
 667 {
 668   if(addr.empty())
 669     return -1;
 670   string ourAddr(addr);
 671   bool portSet = false;
 672   unsigned int port;
 673   if(addr[0]=='[') { // [::]:53 style address
 674     string::size_type pos = addr.find(']');
 675     if(pos == string::npos)
 676       return -1;
 677     ourAddr.assign(addr.c_str() + 1, pos-1);
 678     if (pos + 1 != addr.size()) { // complete after ], no port specified
 679       if (pos + 2 > addr.size() || addr[pos+1]!=':')
 680         return -1;
 681       try {
 682         port = pdns_stou(addr.substr(pos+2));
 683         portSet = true;
 684       }
 685       catch(const std::out_of_range&) {
 686         return -1;
 687       }
 688     }
 689   }
 690   ret->sin6_scope_id=0;
 691   ret->sin6_family=AF_INET6;
 692
 693   if(inet_pton(AF_INET6, ourAddr.c_str(), (void*)&ret->sin6_addr) != 1) {
 694     struct addrinfo* res;
 695     struct addrinfo hints;
 696     memset(&hints, 0, sizeof(hints));
 697
 698     hints.ai_family = AF_INET6;
 699     hints.ai_flags = AI_NUMERICHOST;
 700
 701     // getaddrinfo has anomalous return codes, anything nonzero is an error, positive or negative
 702     if (getaddrinfo(ourAddr.c_str(), 0, &hints, &res) != 0) {
 703       return -1;
 704     }
 705
 706     memcpy(ret, res->ai_addr, res->ai_addrlen);
 707     freeaddrinfo(res);
 708   }
 709
 710   if(portSet) {
 711     if(port > 65535)
 712       return -1;
 713
 714     ret->sin6_port = htons(port);
 715   }
 716
 717   return 0;
 718 }
 719
 720 int makeIPv4sockaddr(const std::string& str, struct sockaddr_in* ret)
 721 {
 722   if(str.empty()) {
 723     return -1;
 724   }
 725   struct in_addr inp;
 726
 727   string::size_type pos = str.find(':');
 728   if(pos == string::npos) { // no port specified, not touching the port
 729     if(inet_aton(str.c_str(), &inp)) {
 730       ret->sin_addr.s_addr=inp.s_addr;
 731       return 0;
 732     }
 733     return -1;
 734   }
 735   if(!*(str.c_str() + pos + 1)) // trailing :
 736     return -1;
 737
 738   char *eptr = (char*)str.c_str() + str.size();
 739   int port = strtol(str.c_str() + pos + 1, &eptr, 10);
 740   if (port < 0 || port > 65535)
 741     return -1;
 742
 743   if(*eptr)
 744     return -1;
 745
 746   ret->sin_port = htons(port);
 747   if(inet_aton(str.substr(0, pos).c_str(), &inp)) {
 748     ret->sin_addr.s_addr=inp.s_addr;
 749     return 0;
 750   }
 751   return -1;
 752 }
 753
 754 int makeUNsockaddr(const std::string& path, struct sockaddr_un* ret)
 755 {
 756   if (path.empty())
 757     return -1;
 758
 759   memset(ret, 0, sizeof(struct sockaddr_un));
 760   ret->sun_family = AF_UNIX;
 761   if (path.length() >= sizeof(ret->sun_path))
 762     return -1;
 763
 764   path.copy(ret->sun_path, sizeof(ret->sun_path), 0);
 765   return 0;
 766 }
 767
 768 //! read a line of text from a FILE* to a std::string, returns false on 'no data'
 769 bool stringfgets(FILE* fp, std::string& line)
 770 {
 771   char buffer[1024];
 772   line.clear();
 773
 774   do {
 775     if(!fgets(buffer, sizeof(buffer), fp))
 776       return !line.empty();
 777
 778     line.append(buffer);
 779   } while(!strchr(buffer, '\n'));
 780   return true;
 781 }
 782
 783 bool readFileIfThere(const char* fname, std::string* line)
 784 {
 785   line->clear();
 786   auto fp = std::unique_ptr<FILE, int(*)(FILE*)>(fopen(fname, "r"), fclose);
 787   if(!fp)
 788     return false;
 789   stringfgets(fp.get(), *line);
 790   fp.reset();
 791
 792   return true;
 793 }
 794
 795 Regex::Regex(const string &expr)
 796 {
 797   if(regcomp(&d_preg, expr.c_str(), REG_ICASE|REG_NOSUB|REG_EXTENDED))
 798     throw PDNSException("Regular expression did not compile");
 799 }
 800
 801 // if you end up here because valgrind told you were are doing something wrong
 802 // with msgh->msg_controllen, please refer to https://github.com/PowerDNS/pdns/pull/3962
 803 // first.
 804 // Note that cmsgbuf should be aligned the same as a struct cmsghdr
 805 void addCMsgSrcAddr(struct msghdr* msgh, cmsgbuf_aligned* cmsgbuf, const ComboAddress* source, int itfIndex)
 806 {
 807   struct cmsghdr *cmsg = NULL;
 808
 809   if(source->sin4.sin_family == AF_INET6) {
 810     struct in6_pktinfo *pkt;
 811
 812     msgh->msg_control = cmsgbuf;
 813 #if !defined( __APPLE__ )
 814     /* CMSG_SPACE is not a constexpr on macOS */
 815     static_assert(CMSG_SPACE(sizeof(*pkt)) <= sizeof(*cmsgbuf), "Buffer is too small for in6_pktinfo");
 816 #else /* __APPLE__ */
 817     if (CMSG_SPACE(sizeof(*pkt)) > sizeof(*cmsgbuf)) {
 818       throw std::runtime_error("Buffer is too small for in6_pktinfo");
 819     }
 820 #endif /* __APPLE__ */
 821     msgh->msg_controllen = CMSG_SPACE(sizeof(*pkt));
 822
 823     cmsg = CMSG_FIRSTHDR(msgh);
 824     cmsg->cmsg_level = IPPROTO_IPV6;
 825     cmsg->cmsg_type = IPV6_PKTINFO;
 826     cmsg->cmsg_len = CMSG_LEN(sizeof(*pkt));
 827
 828     pkt = (struct in6_pktinfo *) CMSG_DATA(cmsg);
 829     // Include the padding to stop valgrind complaining about passing uninitialized data
 830     memset(pkt, 0, CMSG_SPACE(sizeof(*pkt)));
 831     pkt->ipi6_addr = source->sin6.sin6_addr;
 832     pkt->ipi6_ifindex = itfIndex;
 833   }
 834   else {
 835 #if defined(IP_PKTINFO)
 836     struct in_pktinfo *pkt;
 837
 838     msgh->msg_control = cmsgbuf;
 839 #if !defined( __APPLE__ )
 840     /* CMSG_SPACE is not a constexpr on macOS */
 841     static_assert(CMSG_SPACE(sizeof(*pkt)) <= sizeof(*cmsgbuf), "Buffer is too small for in_pktinfo");
 842 #else /* __APPLE__ */
 843     if (CMSG_SPACE(sizeof(*pkt)) > sizeof(*cmsgbuf)) {
 844       throw std::runtime_error("Buffer is too small for in_pktinfo");
 845     }
 846 #endif /* __APPLE__ */
 847     msgh->msg_controllen = CMSG_SPACE(sizeof(*pkt));
 848
 849     cmsg = CMSG_FIRSTHDR(msgh);
 850     cmsg->cmsg_level = IPPROTO_IP;
 851     cmsg->cmsg_type = IP_PKTINFO;
 852     cmsg->cmsg_len = CMSG_LEN(sizeof(*pkt));
 853
 854     pkt = (struct in_pktinfo *) CMSG_DATA(cmsg);
 855     // Include the padding to stop valgrind complaining about passing uninitialized data
 856     memset(pkt, 0, CMSG_SPACE(sizeof(*pkt)));
 857     pkt->ipi_spec_dst = source->sin4.sin_addr;
 858     pkt->ipi_ifindex = itfIndex;
 859 #elif defined(IP_SENDSRCADDR)
 860     struct in_addr *in;
 861
 862     msgh->msg_control = cmsgbuf;
 863 #if !defined( __APPLE__ )
 864     static_assert(CMSG_SPACE(sizeof(*in)) <= sizeof(*cmsgbuf), "Buffer is too small for in_addr");
 865 #else /* __APPLE__ */
 866     if (CMSG_SPACE(sizeof(*in)) > sizeof(*cmsgbuf)) {
 867       throw std::runtime_error("Buffer is too small for in_addr");
 868     }
 869 #endif /* __APPLE__ */
 870     msgh->msg_controllen = CMSG_SPACE(sizeof(*in));
 871
 872     cmsg = CMSG_FIRSTHDR(msgh);
 873     cmsg->cmsg_level = IPPROTO_IP;
 874     cmsg->cmsg_type = IP_SENDSRCADDR;
 875     cmsg->cmsg_len = CMSG_LEN(sizeof(*in));
 876
 877     // Include the padding to stop valgrind complaining about passing uninitialized data
 878     in = (struct in_addr *) CMSG_DATA(cmsg);
 879     memset(in, 0, CMSG_SPACE(sizeof(*in)));
 880     *in = source->sin4.sin_addr;
 881 #endif
 882   }
 883 }
 884
 885 unsigned int getFilenumLimit(bool hardOrSoft)
 886 {
 887   struct rlimit rlim;
 888   if(getrlimit(RLIMIT_NOFILE, &rlim) < 0)
 889     unixDie("Requesting number of available file descriptors");
 890   return hardOrSoft ? rlim.rlim_max : rlim.rlim_cur;
 891 }
 892
 893 void setFilenumLimit(unsigned int lim)
 894 {
 895   struct rlimit rlim;
 896
 897   if(getrlimit(RLIMIT_NOFILE, &rlim) < 0)
 898     unixDie("Requesting number of available file descriptors");
 899   rlim.rlim_cur=lim;
 900   if(setrlimit(RLIMIT_NOFILE, &rlim) < 0)
 901     unixDie("Setting number of available file descriptors");
 902 }
 903
 904 #define burtlemix(a,b,c) \
 905 { \
 906   a -= b; a -= c; a ^= (c>>13); \
 907   b -= c; b -= a; b ^= (a<<8); \
 908   c -= a; c -= b; c ^= (b>>13); \
 909   a -= b; a -= c; a ^= (c>>12);  \
 910   b -= c; b -= a; b ^= (a<<16); \
 911   c -= a; c -= b; c ^= (b>>5); \
 912   a -= b; a -= c; a ^= (c>>3);  \
 913   b -= c; b -= a; b ^= (a<<10); \
 914   c -= a; c -= b; c ^= (b>>15); \
 915 }
 916
 917 uint32_t burtle(const unsigned char* k, uint32_t length, uint32_t initval)
 918 {
 919   uint32_t a,b,c,len;
 920
 921    /* Set up the internal state */
 922   len = length;
 923   a = b = 0x9e3779b9;  /* the golden ratio; an arbitrary value */
 924   c = initval;         /* the previous hash value */
 925
 926   /*---------------------------------------- handle most of the key */
 927   while (len >= 12) {
 928     a += (k[0] +((uint32_t)k[1]<<8) +((uint32_t)k[2]<<16) +((uint32_t)k[3]<<24));
 929     b += (k[4] +((uint32_t)k[5]<<8) +((uint32_t)k[6]<<16) +((uint32_t)k[7]<<24));
 930     c += (k[8] +((uint32_t)k[9]<<8) +((uint32_t)k[10]<<16)+((uint32_t)k[11]<<24));
 931     burtlemix(a,b,c);
 932     k += 12; len -= 12;
 933   }
 934
 935   /*------------------------------------- handle the last 11 bytes */
 936   c += length;
 937   switch(len) {             /* all the case statements fall through */
 938   case 11: c+=((uint32_t)k[10]<<24);
 939     /* fall-through */
 940   case 10: c+=((uint32_t)k[9]<<16);
 941     /* fall-through */
 942   case 9 : c+=((uint32_t)k[8]<<8);
 943     /* the first byte of c is reserved for the length */
 944     /* fall-through */
 945   case 8 : b+=((uint32_t)k[7]<<24);
 946     /* fall-through */
 947   case 7 : b+=((uint32_t)k[6]<<16);
 948     /* fall-through */
 949   case 6 : b+=((uint32_t)k[5]<<8);
 950     /* fall-through */
 951   case 5 : b+=k[4];
 952     /* fall-through */
 953   case 4 : a+=((uint32_t)k[3]<<24);
 954     /* fall-through */
 955   case 3 : a+=((uint32_t)k[2]<<16);
 956     /* fall-through */
 957   case 2 : a+=((uint32_t)k[1]<<8);
 958     /* fall-through */
 959   case 1 : a+=k[0];
 960     /* case 0: nothing left to add */
 961   }
 962   burtlemix(a,b,c);
 963   /*-------------------------------------------- report the result */
 964   return c;
 965 }
 966
 967 uint32_t burtleCI(const unsigned char* k, uint32_t length, uint32_t initval)
 968 {
 969   uint32_t a,b,c,len;
 970
 971    /* Set up the internal state */
 972   len = length;
 973   a = b = 0x9e3779b9;  /* the golden ratio; an arbitrary value */
 974   c = initval;         /* the previous hash value */
 975
 976   /*---------------------------------------- handle most of the key */
 977   while (len >= 12) {
 978     a += (dns_tolower(k[0]) +((uint32_t)dns_tolower(k[1])<<8) +((uint32_t)dns_tolower(k[2])<<16) +((uint32_t)dns_tolower(k[3])<<24));
 979     b += (dns_tolower(k[4]) +((uint32_t)dns_tolower(k[5])<<8) +((uint32_t)dns_tolower(k[6])<<16) +((uint32_t)dns_tolower(k[7])<<24));
 980     c += (dns_tolower(k[8]) +((uint32_t)dns_tolower(k[9])<<8) +((uint32_t)dns_tolower(k[10])<<16)+((uint32_t)dns_tolower(k[11])<<24));
 981     burtlemix(a,b,c);
 982     k += 12; len -= 12;
 983   }
 984
 985   /*------------------------------------- handle the last 11 bytes */
 986   c += length;
 987   switch(len) {             /* all the case statements fall through */
 988   case 11: c+=((uint32_t)dns_tolower(k[10])<<24);
 989     /* fall-through */
 990   case 10: c+=((uint32_t)dns_tolower(k[9])<<16);
 991     /* fall-through */
 992   case 9 : c+=((uint32_t)dns_tolower(k[8])<<8);
 993     /* the first byte of c is reserved for the length */
 994     /* fall-through */
 995   case 8 : b+=((uint32_t)dns_tolower(k[7])<<24);
 996     /* fall-through */
 997   case 7 : b+=((uint32_t)dns_tolower(k[6])<<16);
 998     /* fall-through */
 999   case 6 : b+=((uint32_t)dns_tolower(k[5])<<8);
1000     /* fall-through */
1001   case 5 : b+=dns_tolower(k[4]);
1002     /* fall-through */
1003   case 4 : a+=((uint32_t)dns_tolower(k[3])<<24);
1004     /* fall-through */
1005   case 3 : a+=((uint32_t)dns_tolower(k[2])<<16);
1006     /* fall-through */
1007   case 2 : a+=((uint32_t)dns_tolower(k[1])<<8);
1008     /* fall-through */
1009   case 1 : a+=dns_tolower(k[0]);
1010     /* case 0: nothing left to add */
1011   }
1012   burtlemix(a,b,c);
1013   /*-------------------------------------------- report the result */
1014   return c;
1015 }
1016
1017
1018 bool setSocketTimestamps(int fd)
1019 {
1020 #ifdef SO_TIMESTAMP
1021   int on=1;
1022   return setsockopt(fd, SOL_SOCKET, SO_TIMESTAMP, (char*)&on, sizeof(on)) == 0;
1023 #else
1024   return true; // we pretend this happened.
1025 #endif
1026 }
1027
1028 bool setTCPNoDelay(int sock)
1029 {
1030   int flag = 1;
1031   return setsockopt(sock,            /* socket affected */
1032                     IPPROTO_TCP,     /* set option at TCP level */
1033                     TCP_NODELAY,     /* name of option */
1034                     (char *) &flag,  /* the cast is historical cruft */
1035                     sizeof(flag)) == 0;    /* length of option value */
1036 }
1037
1038
1039 bool setNonBlocking(int sock)
1040 {
1041   int flags=fcntl(sock,F_GETFL,0);
1042   if(flags<0 || fcntl(sock, F_SETFL,flags|O_NONBLOCK) <0)
1043     return false;
1044   return true;
1045 }
1046
1047 bool setBlocking(int sock)
1048 {
1049   int flags=fcntl(sock,F_GETFL,0);
1050   if(flags<0 || fcntl(sock, F_SETFL,flags&(~O_NONBLOCK)) <0)
1051     return false;
1052   return true;
1053 }
1054
1055 bool setReuseAddr(int sock)
1056 {
1057   int tmp = 1;
1058   if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char*)&tmp, static_cast<unsigned>(sizeof tmp))<0)
1059     throw PDNSException(string("Setsockopt failed: ")+stringerror());
1060   return true;
1061 }
1062
1063 bool isNonBlocking(int sock)
1064 {
1065   int flags=fcntl(sock,F_GETFL,0);
1066   return flags & O_NONBLOCK;
1067 }
1068
1069 bool setReceiveSocketErrors(int sock, int af)
1070 {
1071 #ifdef __linux__
1072   int tmp = 1, ret;
1073   if (af == AF_INET) {
1074     ret = setsockopt(sock, IPPROTO_IP, IP_RECVERR, &tmp, sizeof(tmp));
1075   } else {
1076     ret = setsockopt(sock, IPPROTO_IPV6, IPV6_RECVERR, &tmp, sizeof(tmp));
1077   }
1078   if (ret < 0) {
1079     throw PDNSException(string("Setsockopt failed: ") + stringerror());
1080   }
1081 #endif
1082   return true;
1083 }
1084
1085 // Closes a socket.
1086 int closesocket( int socket )
1087 {
1088   int ret=::close(socket);
1089   if(ret < 0 && errno == ECONNRESET) // see ticket 192, odd BSD behaviour
1090     return 0;
1091   if(ret < 0)
1092     throw PDNSException("Error closing socket: "+stringerror());
1093   return ret;
1094 }
1095
1096 bool setCloseOnExec(int sock)
1097 {
1098   int flags=fcntl(sock,F_GETFD,0);
1099   if(flags<0 || fcntl(sock, F_SETFD,flags|FD_CLOEXEC) <0)
1100     return false;
1101   return true;
1102 }
1103
1104 string getMACAddress(const ComboAddress& ca)
1105 {
1106   string ret;
1107 #ifdef __linux__
1108   ifstream ifs("/proc/net/arp");
1109   if(!ifs)
1110     return ret;
1111   string line;
1112   string match=ca.toString()+' ';
1113   while(getline(ifs, line)) {
1114     if(boost::starts_with(line, match)) {
1115       vector<string> parts;
1116       stringtok(parts, line, " \n\t\r");
1117       if(parts.size() < 4)
1118         return ret;
1119       unsigned int tmp[6];
1120       sscanf(parts[3].c_str(), "%02x:%02x:%02x:%02x:%02x:%02x", tmp, tmp+1, tmp+2, tmp+3, tmp+4, tmp+5);
1121       for(int i = 0 ; i< 6 ; ++i)
1122         ret.append(1, (char)tmp[i]);
1123       return ret;
1124     }
1125   }
1126 #endif
1127   return ret;
1128 }
1129
1130 uint64_t udpErrorStats(const std::string& str)
1131 {
1132 #ifdef __linux__
1133   ifstream ifs("/proc/net/snmp");
1134   if(!ifs)
1135     return 0;
1136   string line;
1137   vector<string> parts;
1138   while(getline(ifs,line)) {
1139     if(boost::starts_with(line, "Udp: ") && isdigit(line[5])) {
1140       stringtok(parts, line, " \n\t\r");
1141       if(parts.size() < 7)
1142         break;
1143       if(str=="udp-rcvbuf-errors")
1144         return std::stoull(parts[5]);
1145       else if(str=="udp-sndbuf-errors")
1146         return std::stoull(parts[6]);
1147       else if(str=="udp-noport-errors")
1148         return std::stoull(parts[2]);
1149       else if(str=="udp-in-errors")
1150         return std::stoull(parts[3]);
1151       else
1152         return 0;
1153     }
1154   }
1155 #endif
1156   return 0;
1157 }
1158
1159 uint64_t getCPUIOWait(const std::string& str)
1160 {
1161 #ifdef __linux__
1162   ifstream ifs("/proc/stat");
1163   if (!ifs) {
1164     return 0;
1165   }
1166
1167   string line;
1168   vector<string> parts;
1169   while (getline(ifs, line)) {
1170     if (boost::starts_with(line, "cpu ")) {
1171       stringtok(parts, line, " \n\t\r");
1172
1173       if (parts.size() < 6) {
1174         break;
1175       }
1176
1177       return std::stoull(parts[5]);
1178     }
1179   }
1180 #endif
1181   return 0;
1182 }
1183
1184 uint64_t getCPUSteal(const std::string& str)
1185 {
1186 #ifdef __linux__
1187   ifstream ifs("/proc/stat");
1188   if (!ifs) {
1189     return 0;
1190   }
1191
1192   string line;
1193   vector<string> parts;
1194   while (getline(ifs, line)) {
1195     if (boost::starts_with(line, "cpu ")) {
1196       stringtok(parts, line, " \n\t\r");
1197
1198       if (parts.size() < 9) {
1199         break;
1200       }
1201
1202       return std::stoull(parts[8]);
1203     }
1204   }
1205 #endif
1206   return 0;
1207 }
1208
1209 bool getTSIGHashEnum(const DNSName& algoName, TSIGHashEnum& algoEnum)
1210 {
1211   if (algoName == DNSName("hmac-md5.sig-alg.reg.int") || algoName == DNSName("hmac-md5"))
1212     algoEnum = TSIG_MD5;
1213   else if (algoName == DNSName("hmac-sha1"))
1214     algoEnum = TSIG_SHA1;
1215   else if (algoName == DNSName("hmac-sha224"))
1216     algoEnum = TSIG_SHA224;
1217   else if (algoName == DNSName("hmac-sha256"))
1218     algoEnum = TSIG_SHA256;
1219   else if (algoName == DNSName("hmac-sha384"))
1220     algoEnum = TSIG_SHA384;
1221   else if (algoName == DNSName("hmac-sha512"))
1222     algoEnum = TSIG_SHA512;
1223   else if (algoName == DNSName("gss-tsig"))
1224     algoEnum = TSIG_GSS;
1225   else {
1226      return false;
1227   }
1228   return true;
1229 }
1230
1231 DNSName getTSIGAlgoName(TSIGHashEnum& algoEnum)
1232 {
1233   switch(algoEnum) {
1234   case TSIG_MD5: return DNSName("hmac-md5.sig-alg.reg.int.");
1235   case TSIG_SHA1: return DNSName("hmac-sha1.");
1236   case TSIG_SHA224: return DNSName("hmac-sha224.");
1237   case TSIG_SHA256: return DNSName("hmac-sha256.");
1238   case TSIG_SHA384: return DNSName("hmac-sha384.");
1239   case TSIG_SHA512: return DNSName("hmac-sha512.");
1240   case TSIG_GSS: return DNSName("gss-tsig.");
1241   }
1242   throw PDNSException("getTSIGAlgoName does not understand given algorithm, please fix!");
1243 }
1244
1245 uint64_t getOpenFileDescriptors(const std::string&)
1246 {
1247 #ifdef __linux__
1248   DIR* dirhdl=opendir(("/proc/"+std::to_string(getpid())+"/fd/").c_str());
1249   if(!dirhdl)
1250     return 0;
1251
1252   struct dirent *entry;
1253   int ret=0;
1254   while((entry = readdir(dirhdl))) {
1255     uint32_t num;
1256     try {
1257       num = pdns_stou(entry->d_name);
1258     } catch (...) {
1259       continue; // was not a number.
1260     }
1261     if(std::to_string(num) == entry->d_name)
1262       ret++;
1263   }
1264   closedir(dirhdl);
1265   return ret;
1266
1267 #else
1268   return 0;
1269 #endif
1270 }
1271
1272 uint64_t getRealMemoryUsage(const std::string&)
1273 {
1274 #ifdef __linux__
1275   ifstream ifs("/proc/self/statm");
1276   if(!ifs)
1277     return 0;
1278
1279   uint64_t size, resident, shared, text, lib, data;
1280   ifs >> size >> resident >> shared >> text >> lib >> data;
1281
1282   return data * getpagesize();
1283 #else
1284   struct rusage ru;
1285   if (getrusage(RUSAGE_SELF, &ru) != 0)
1286     return 0;
1287   return ru.ru_maxrss * 1024;
1288 #endif
1289 }
1290
1291
1292 uint64_t getSpecialMemoryUsage(const std::string&)
1293 {
1294 #ifdef __linux__
1295   ifstream ifs("/proc/self/smaps");
1296   if(!ifs)
1297     return 0;
1298   string line;
1299   uint64_t bytes=0;
1300   string header("Private_Dirty:");
1301   while(getline(ifs, line)) {
1302     if(boost::starts_with(line, header)) {
1303       bytes += std::stoull(line.substr(header.length() + 1))*1024;
1304     }
1305   }
1306   return bytes;
1307 #else
1308   return 0;
1309 #endif
1310 }
1311
1312 uint64_t getCPUTimeUser(const std::string&)
1313 {
1314   struct rusage ru;
1315   getrusage(RUSAGE_SELF, &ru);
1316   return (ru.ru_utime.tv_sec*1000ULL + ru.ru_utime.tv_usec/1000);
1317 }
1318
1319 uint64_t getCPUTimeSystem(const std::string&)
1320 {
1321   struct rusage ru;
1322   getrusage(RUSAGE_SELF, &ru);
1323   return (ru.ru_stime.tv_sec*1000ULL + ru.ru_stime.tv_usec/1000);
1324 }
1325
1326 double DiffTime(const struct timespec& first, const struct timespec& second)
1327 {
1328   int seconds=second.tv_sec - first.tv_sec;
1329   int nseconds=second.tv_nsec - first.tv_nsec;
1330
1331   if(nseconds < 0) {
1332     seconds-=1;
1333     nseconds+=1000000000;
1334   }
1335   return seconds + nseconds/1000000000.0;
1336 }
1337
1338 double DiffTime(const struct timeval& first, const struct timeval& second)
1339 {
1340   int seconds=second.tv_sec - first.tv_sec;
1341   int useconds=second.tv_usec - first.tv_usec;
1342
1343   if(useconds < 0) {
1344     seconds-=1;
1345     useconds+=1000000;
1346   }
1347   return seconds + useconds/1000000.0;
1348 }
1349
1350 uid_t strToUID(const string &str)
1351 {
1352   uid_t result = 0;
1353   const char * cstr = str.c_str();
1354   struct passwd * pwd = getpwnam(cstr);
1355
1356   if (pwd == NULL) {
1357     long long val;
1358
1359     try {
1360       val = stoll(str);
1361     }
1362     catch(std::exception& e) {
1363       throw runtime_error((boost::format("Error: Unable to parse user ID %s") % cstr).str() );
1364     }
1365
1366     if (val < std::numeric_limits<uid_t>::min() || val > std::numeric_limits<uid_t>::max()) {
1367       throw runtime_error((boost::format("Error: Unable to parse user ID %s") % cstr).str() );
1368     }
1369
1370     result = static_cast<uid_t>(val);
1371   }
1372   else {
1373     result = pwd->pw_uid;
1374   }
1375
1376   return result;
1377 }
1378
1379 gid_t strToGID(const string &str)
1380 {
1381   gid_t result = 0;
1382   const char * cstr = str.c_str();
1383   struct group * grp = getgrnam(cstr);
1384
1385   if (grp == NULL) {
1386     long long val;
1387
1388     try {
1389       val = stoll(str);
1390     }
1391     catch(std::exception& e) {
1392       throw runtime_error((boost::format("Error: Unable to parse group ID %s") % cstr).str() );
1393     }
1394
1395     if (val < std::numeric_limits<gid_t>::min() || val > std::numeric_limits<gid_t>::max()) {
1396       throw runtime_error((boost::format("Error: Unable to parse group ID %s") % cstr).str() );
1397     }
1398
1399     result = static_cast<gid_t>(val);
1400   }
1401   else {
1402     result = grp->gr_gid;
1403   }
1404
1405   return result;
1406 }
1407
1408 unsigned int pdns_stou(const std::string& str, size_t * idx, int base)
1409 {
1410   if (str.empty()) return 0; // compatibility
1411   unsigned long result;
1412   try {
1413     result = std::stoul(str, idx, base);
1414   }
1415   catch(std::invalid_argument& e) {
1416     throw std::invalid_argument(string(e.what()) + "; (invalid argument during std::stoul); data was \""+str+"\"");
1417   }
1418   catch(std::out_of_range& e) {
1419     throw std::out_of_range(string(e.what()) + "; (out of range during std::stoul); data was \""+str+"\"");
1420   }
1421   if (result > std::numeric_limits<unsigned int>::max()) {
1422     throw std::out_of_range("stoul returned result out of unsigned int range; data was \""+str+"\"");
1423   }
1424   return static_cast<unsigned int>(result);
1425 }
1426
1427 bool isSettingThreadCPUAffinitySupported()
1428 {
1429 #ifdef HAVE_PTHREAD_SETAFFINITY_NP
1430   return true;
1431 #else
1432   return false;
1433 #endif
1434 }
1435
1436 int mapThreadToCPUList(pthread_t tid, const std::set<int>& cpus)
1437 {
1438 #ifdef HAVE_PTHREAD_SETAFFINITY_NP
1439 #  ifdef __NetBSD__
1440   cpuset_t *cpuset;
1441   cpuset = cpuset_create();
1442   for (const auto cpuID : cpus) {
1443     cpuset_set(cpuID, cpuset);
1444   }
1445
1446   return pthread_setaffinity_np(tid,
1447                                 cpuset_size(cpuset),
1448                                 cpuset);
1449 #  else
1450 #    ifdef __FreeBSD__
1451 #      define cpu_set_t cpuset_t
1452 #    endif
1453   cpu_set_t cpuset;
1454   CPU_ZERO(&cpuset);
1455   for (const auto cpuID : cpus) {
1456     CPU_SET(cpuID, &cpuset);
1457   }
1458
1459   return pthread_setaffinity_np(tid,
1460                                 sizeof(cpuset),
1461                                 &cpuset);
1462 #  endif
1463 #else
1464   return ENOSYS;
1465 #endif /* HAVE_PTHREAD_SETAFFINITY_NP */
1466 }
1467
1468 std::vector<ComboAddress> getResolvers(const std::string& resolvConfPath)
1469 {
1470   std::vector<ComboAddress> results;
1471
1472   ifstream ifs(resolvConfPath);
1473   if (!ifs) {
1474     return results;
1475   }
1476
1477   string line;
1478   while(std::getline(ifs, line)) {
1479     boost::trim_right_if(line, is_any_of(" \r\n\x1a"));
1480     boost::trim_left(line); // leading spaces, let's be nice
1481
1482     string::size_type tpos = line.find_first_of(";#");
1483     if (tpos != string::npos) {
1484       line.resize(tpos);
1485     }
1486
1487     if (boost::starts_with(line, "nameserver ") || boost::starts_with(line, "nameserver\t")) {
1488       vector<string> parts;
1489       stringtok(parts, line, " \t,"); // be REALLY nice
1490       for(vector<string>::const_iterator iter = parts.begin() + 1; iter != parts.end(); ++iter) {
1491         try {
1492           results.emplace_back(*iter, 53);
1493         }
1494         catch(...)
1495         {
1496         }
1497       }
1498     }
1499   }
1500
1501   return results;
1502 }
1503
1504 size_t getPipeBufferSize(int fd)
1505 {
1506 #ifdef F_GETPIPE_SZ
1507   int res = fcntl(fd, F_GETPIPE_SZ);
1508   if (res == -1) {
1509     return 0;
1510   }
1511   return res;
1512 #else
1513   errno = ENOSYS;
1514   return 0;
1515 #endif /* F_GETPIPE_SZ */
1516 }
1517
1518 bool setPipeBufferSize(int fd, size_t size)
1519 {
1520 #ifdef F_SETPIPE_SZ
1521   if (size > std::numeric_limits<int>::max()) {
1522     errno = EINVAL;
1523     return false;
1524   }
1525   int newSize = static_cast<int>(size);
1526   int res = fcntl(fd, F_SETPIPE_SZ, newSize);
1527   if (res == -1) {
1528     return false;
1529   }
1530   return true;
1531 #else
1532   errno = ENOSYS;
1533   return false;
1534 #endif /* F_SETPIPE_SZ */
1535 }
1536
1537 DNSName reverseNameFromIP(const ComboAddress& ip)
1538 {
1539   if (ip.isIPv4()) {
1540     std::string result("in-addr.arpa.");
1541     auto ptr = reinterpret_cast<const uint8_t*>(&ip.sin4.sin_addr.s_addr);
1542     for (size_t idx = 0; idx < sizeof(ip.sin4.sin_addr.s_addr); idx++) {
1543       result = std::to_string(ptr[idx]) + "." + result;
1544     }
1545     return DNSName(result);
1546   }
1547   else if (ip.isIPv6()) {
1548     std::string result("ip6.arpa.");
1549     auto ptr = reinterpret_cast<const uint8_t*>(&ip.sin6.sin6_addr.s6_addr[0]);
1550     for (size_t idx = 0; idx < sizeof(ip.sin6.sin6_addr.s6_addr); idx++) {
1551       std::stringstream stream;
1552       stream << std::hex << (ptr[idx] & 0x0F);
1553       stream << '.';
1554       stream << std::hex << (((ptr[idx]) >> 4) & 0x0F);
1555       stream << '.';
1556       result = stream.str() + result;
1557     }
1558     return DNSName(result);
1559   }
1560
1561   throw std::runtime_error("Calling reverseNameFromIP() for an address which is neither an IPv4 nor an IPv6");
1562 }