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
  61
  62 bool g_singleThreaded;
  63
  64 size_t writen2(int fd, const void *buf, size_t count)
  65 {
  66   const char *ptr = (char*)buf;
  67   const char *eptr = ptr + count;
  68
  69   ssize_t res;
  70   while(ptr != eptr) {
  71     res = ::write(fd, ptr, eptr - ptr);
  72     if(res < 0) {
  73       if (errno == EAGAIN)
  74         throw std::runtime_error("used writen2 on non-blocking socket, got EAGAIN");
  75       else
  76         unixDie("failed in writen2");
  77     }
  78     else if (res == 0)
  79       throw std::runtime_error("could not write all bytes, got eof in writen2");
  80
  81     ptr += (size_t) res;
  82   }
  83
  84   return count;
  85 }
  86
  87 size_t readn2(int fd, void* buffer, size_t len)
  88 {
  89   size_t pos=0;
  90   ssize_t res;
  91   for(;;) {
  92     res = read(fd, (char*)buffer + pos, len - pos);
  93     if(res == 0)
  94       throw runtime_error("EOF while reading message");
  95     if(res < 0) {
  96       if (errno == EAGAIN)
  97         throw std::runtime_error("used readn2 on non-blocking socket, got EAGAIN");
  98       else
  99         unixDie("failed in readn2");
 100     }
 101
 102     pos+=(size_t)res;
 103     if(pos == len)
 104       break;
 105   }
 106   return len;
 107 }
 108
 109 size_t readn2WithTimeout(int fd, void* buffer, size_t len, int timeout)
 110 {
 111   size_t pos = 0;
 112   do {
 113     ssize_t got = read(fd, (char *)buffer + pos, len - pos);
 114     if (got > 0) {
 115       pos += (size_t) got;
 116     }
 117     else if (got == 0) {
 118       throw runtime_error("EOF while reading message");
 119     }
 120     else {
 121       if (errno == EAGAIN) {
 122         int res = waitForData(fd, timeout);
 123         if (res > 0) {
 124           /* there is data available */
 125         }
 126         else if (res == 0) {
 127           throw runtime_error("Timeout while waiting for data to read");
 128         } else {
 129           throw runtime_error("Error while waiting for data to read");
 130         }
 131       }
 132       else {
 133         unixDie("failed in readn2WithTimeout");
 134       }
 135     }
 136   }
 137   while (pos < len);
 138
 139   return len;
 140 }
 141
 142 size_t writen2WithTimeout(int fd, const void * buffer, size_t len, int timeout)
 143 {
 144   size_t pos = 0;
 145   do {
 146     ssize_t written = write(fd, (char *)buffer + pos, len - pos);
 147
 148     if (written > 0) {
 149       pos += (size_t) written;
 150     }
 151     else if (written == 0)
 152       throw runtime_error("EOF while writing message");
 153     else {
 154       if (errno == EAGAIN) {
 155         int res = waitForRWData(fd, false, timeout, 0);
 156         if (res > 0) {
 157           /* there is room available */
 158         }
 159         else if (res == 0) {
 160           throw runtime_error("Timeout while waiting to write data");
 161         } else {
 162           throw runtime_error("Error while waiting for room to write data");
 163         }
 164       }
 165       else {
 166         unixDie("failed in write2WithTimeout");
 167       }
 168     }
 169   }
 170   while (pos < len);
 171
 172   return len;
 173 }
 174
 175 string nowTime()
 176 {
 177   time_t now = time(nullptr);
 178   struct tm* tm = localtime(&now);
 179   char buffer[30];
 180   // YYYY-mm-dd HH:MM:SS TZOFF
 181   strftime(buffer, sizeof(buffer), "%F %T %z", tm);
 182   buffer[sizeof(buffer)-1] = '\0';
 183   return buffer;
 184 }
 185
 186 uint16_t getShort(const unsigned char *p)
 187 {
 188   return p[0] * 256 + p[1];
 189 }
 190
 191
 192 uint16_t getShort(const char *p)
 193 {
 194   return getShort((const unsigned char *)p);
 195 }
 196
 197 uint32_t getLong(const unsigned char* p)
 198 {
 199   return (p[0]<<24) + (p[1]<<16) + (p[2]<<8) + p[3];
 200 }
 201
 202 uint32_t getLong(const char* p)
 203 {
 204   return getLong((unsigned char *)p);
 205 }
 206
 207 static bool ciEqual(const string& a, const string& b)
 208 {
 209   if(a.size()!=b.size())
 210     return false;
 211
 212   string::size_type pos=0, epos=a.size();
 213   for(;pos < epos; ++pos)
 214     if(dns_tolower(a[pos])!=dns_tolower(b[pos]))
 215       return false;
 216   return true;
 217 }
 218
 219 /** does domain end on suffix? Is smart about "wwwds9a.nl" "ds9a.nl" not matching */
 220 static bool endsOn(const string &domain, const string &suffix)
 221 {
 222   if( suffix.empty() || ciEqual(domain, suffix) )
 223     return true;
 224
 225   if(domain.size()<=suffix.size())
 226     return false;
 227
 228   string::size_type dpos=domain.size()-suffix.size()-1, spos=0;
 229
 230   if(domain[dpos++]!='.')
 231     return false;
 232
 233   for(; dpos < domain.size(); ++dpos, ++spos)
 234     if(dns_tolower(domain[dpos]) != dns_tolower(suffix[spos]))
 235       return false;
 236
 237   return true;
 238 }
 239
 240 /** strips a domain suffix from a domain, returns true if it stripped */
 241 bool stripDomainSuffix(string *qname, const string &domain)
 242 {
 243   if(!endsOn(*qname, domain))
 244     return false;
 245
 246   if(toLower(*qname)==toLower(domain))
 247     *qname="@";
 248   else {
 249     if((*qname)[qname->size()-domain.size()-1]!='.')
 250       return false;
 251
 252     qname->resize(qname->size()-domain.size()-1);
 253   }
 254   return true;
 255 }
 256
 257 static void parseService4(const string &descr, ServiceTuple &st)
 258 {
 259   vector<string>parts;
 260   stringtok(parts,descr,":");
 261   if(parts.empty())
 262     throw PDNSException("Unable to parse '"+descr+"' as a service");
 263   st.host=parts[0];
 264   if(parts.size()>1)
 265     st.port=pdns_stou(parts[1]);
 266 }
 267
 268 static void parseService6(const string &descr, ServiceTuple &st)
 269 {
 270   string::size_type pos=descr.find(']');
 271   if(pos == string::npos)
 272     throw PDNSException("Unable to parse '"+descr+"' as an IPv6 service");
 273
 274   st.host=descr.substr(1, pos-1);
 275   if(pos + 2 < descr.length())
 276     st.port=pdns_stou(descr.substr(pos+2));
 277 }
 278
 279
 280 void parseService(const string &descr, ServiceTuple &st)
 281 {
 282   if(descr.empty())
 283     throw PDNSException("Unable to parse '"+descr+"' as a service");
 284
 285   vector<string> parts;
 286   stringtok(parts, descr, ":");
 287
 288   if(descr[0]=='[') {
 289     parseService6(descr, st);
 290   }
 291   else if(descr[0]==':' || parts.size() > 2 || descr.find("::") != string::npos) {
 292     st.host=descr;
 293   }
 294   else {
 295     parseService4(descr, st);
 296   }
 297 }
 298
 299 // returns -1 in case if error, 0 if no data is available, 1 if there is. In the first two cases, errno is set
 300 int waitForData(int fd, int seconds, int useconds)
 301 {
 302   return waitForRWData(fd, true, seconds, useconds);
 303 }
 304
 305 int waitForRWData(int fd, bool waitForRead, int seconds, int useconds, bool* error, bool* disconnected)
 306 {
 307   int ret;
 308
 309   struct pollfd pfd;
 310   memset(&pfd, 0, sizeof(pfd));
 311   pfd.fd = fd;
 312
 313   if(waitForRead)
 314     pfd.events=POLLIN;
 315   else
 316     pfd.events=POLLOUT;
 317
 318   ret = poll(&pfd, 1, seconds * 1000 + useconds/1000);
 319   if ( ret == -1 ) {
 320     errno = ETIMEDOUT; // ???
 321   }
 322   else if (ret > 0) {
 323     if (error && (pfd.revents & POLLERR)) {
 324       *error = true;
 325     }
 326     if (disconnected && (pfd.revents & POLLHUP)) {
 327       *disconnected = true;
 328     }
 329   }
 330
 331   return ret;
 332 }
 333
 334 // returns -1 in case of error, 0 if no data is available, 1 if there is. In the first two cases, errno is set
 335 int waitFor2Data(int fd1, int fd2, int seconds, int useconds, int*fd)
 336 {
 337   int ret;
 338
 339   struct pollfd pfds[2];
 340   memset(&pfds[0], 0, 2*sizeof(struct pollfd));
 341   pfds[0].fd = fd1;
 342   pfds[1].fd = fd2;
 343
 344   pfds[0].events= pfds[1].events = POLLIN;
 345
 346   int nsocks = 1 + (fd2 >= 0); // fd2 can optionally be -1
 347
 348   if(seconds >= 0)
 349     ret = poll(pfds, nsocks, seconds * 1000 + useconds/1000);
 350   else
 351     ret = poll(pfds, nsocks, -1);
 352   if(!ret || ret < 0)
 353     return ret;
 354
 355   if((pfds[0].revents & POLLIN) && !(pfds[1].revents & POLLIN))
 356     *fd = pfds[0].fd;
 357   else if((pfds[1].revents & POLLIN) && !(pfds[0].revents & POLLIN))
 358     *fd = pfds[1].fd;
 359   else if(ret == 2) {
 360     *fd = pfds[random()%2].fd;
 361   }
 362   else
 363     *fd = -1; // should never happen
 364
 365   return 1;
 366 }
 367
 368
 369 string humanDuration(time_t passed)
 370 {
 371   ostringstream ret;
 372   if(passed<60)
 373     ret<<passed<<" seconds";
 374   else if(passed<3600)
 375     ret<<std::setprecision(2)<<passed/60.0<<" minutes";
 376   else if(passed<86400)
 377     ret<<std::setprecision(3)<<passed/3600.0<<" hours";
 378   else if(passed<(86400*30.41))
 379     ret<<std::setprecision(3)<<passed/86400.0<<" days";
 380   else
 381     ret<<std::setprecision(3)<<passed/(86400*30.41)<<" months";
 382
 383   return ret.str();
 384 }
 385
 386 DTime::DTime()
 387 {
 388 //  set(); // saves lots of gettimeofday calls
 389   d_set.tv_sec=d_set.tv_usec=0;
 390 }
 391
 392 DTime::DTime(const DTime &dt)
 393 {
 394   d_set=dt.d_set;
 395 }
 396
 397 time_t DTime::time()
 398 {
 399   return d_set.tv_sec;
 400 }
 401
 402 const string unquotify(const string &item)
 403 {
 404   if(item.size()<2)
 405     return item;
 406
 407   string::size_type bpos=0, epos=item.size();
 408
 409   if(item[0]=='"')
 410     bpos=1;
 411
 412   if(item[epos-1]=='"')
 413     epos-=1;
 414
 415   return item.substr(bpos,epos-bpos);
 416 }
 417
 418 void stripLine(string &line)
 419 {
 420   string::size_type pos=line.find_first_of("\r\n");
 421   if(pos!=string::npos) {
 422     line.resize(pos);
 423   }
 424 }
 425
 426 string urlEncode(const string &text)
 427 {
 428   string ret;
 429   for(string::const_iterator i=text.begin();i!=text.end();++i)
 430     if(*i==' ')ret.append("%20");
 431     else ret.append(1,*i);
 432   return ret;
 433 }
 434
 435 string getHostname()
 436 {
 437 #ifndef MAXHOSTNAMELEN
 438 #define MAXHOSTNAMELEN 255
 439 #endif
 440
 441   char tmp[MAXHOSTNAMELEN];
 442   if(gethostname(tmp, MAXHOSTNAMELEN))
 443     return "UNKNOWN";
 444
 445   return tmp;
 446 }
 447
 448 string itoa(int i)
 449 {
 450   ostringstream o;
 451   o<<i;
 452   return o.str();
 453 }
 454
 455 string uitoa(unsigned int i) // MSVC 6 doesn't grok overloading (un)signed
 456 {
 457   ostringstream o;
 458   o<<i;
 459   return o.str();
 460 }
 461
 462 string bitFlip(const string &str)
 463 {
 464   string::size_type pos=0, epos=str.size();
 465   string ret;
 466   ret.reserve(epos);
 467   for(;pos < epos; ++pos)
 468     ret.append(1, ~str[pos]);
 469   return ret;
 470 }
 471
 472 string stringerror()
 473 {
 474   return strerror(errno);
 475 }
 476
 477 string netstringerror()
 478 {
 479   return stringerror();
 480 }
 481
 482 void cleanSlashes(string &str)
 483 {
 484   string::const_iterator i;
 485   string out;
 486   for(i=str.begin();i!=str.end();++i) {
 487     if(*i=='/' && i!=str.begin() && *(i-1)=='/')
 488       continue;
 489     out.append(1,*i);
 490   }
 491   str=out;
 492 }
 493
 494
 495 bool IpToU32(const string &str, uint32_t *ip)
 496 {
 497   if(str.empty()) {
 498     *ip=0;
 499     return true;
 500   }
 501
 502   struct in_addr inp;
 503   if(inet_aton(str.c_str(), &inp)) {
 504     *ip=inp.s_addr;
 505     return true;
 506   }
 507   return false;
 508 }
 509
 510 string U32ToIP(uint32_t val)
 511 {
 512   char tmp[17];
 513   snprintf(tmp, sizeof(tmp)-1, "%u.%u.%u.%u",
 514            (val >> 24)&0xff,
 515            (val >> 16)&0xff,
 516            (val >>  8)&0xff,
 517            (val      )&0xff);
 518   return tmp;
 519 }
 520
 521
 522 string makeHexDump(const string& str)
 523 {
 524   char tmp[5];
 525   string ret;
 526   ret.reserve((int)(str.size()*2.2));
 527
 528   for(string::size_type n=0;n<str.size();++n) {
 529     sprintf(tmp,"%02x ", (unsigned char)str[n]);
 530     ret+=tmp;
 531   }
 532   return ret;
 533 }
 534
 535 // shuffle, maintaining some semblance of order
 536 void shuffle(vector<DNSZoneRecord>& rrs)
 537 {
 538   vector<DNSZoneRecord>::iterator first, second;
 539   for(first=rrs.begin();first!=rrs.end();++first)
 540     if(first->dr.d_place==DNSResourceRecord::ANSWER && first->dr.d_type != QType::CNAME) // CNAME must come first
 541       break;
 542   for(second=first;second!=rrs.end();++second)
 543     if(second->dr.d_place!=DNSResourceRecord::ANSWER)
 544       break;
 545
 546   if(second-first > 1)
 547     random_shuffle(first,second);
 548
 549   // now shuffle the additional records
 550   for(first=second;first!=rrs.end();++first)
 551     if(first->dr.d_place==DNSResourceRecord::ADDITIONAL && first->dr.d_type != QType::CNAME) // CNAME must come first
 552       break;
 553   for(second=first;second!=rrs.end();++second)
 554     if(second->dr.d_place!=DNSResourceRecord::ADDITIONAL)
 555       break;
 556
 557   if(second-first>1)
 558     random_shuffle(first,second);
 559
 560   // we don't shuffle the rest
 561 }
 562
 563
 564 // shuffle, maintaining some semblance of order
 565 void shuffle(vector<DNSRecord>& rrs)
 566 {
 567   vector<DNSRecord>::iterator first, second;
 568   for(first=rrs.begin();first!=rrs.end();++first)
 569     if(first->d_place==DNSResourceRecord::ANSWER && first->d_type != QType::CNAME) // CNAME must come first
 570       break;
 571   for(second=first;second!=rrs.end();++second)
 572     if(second->d_place!=DNSResourceRecord::ANSWER || second->d_type == QType::RRSIG) // leave RRSIGs at the end
 573       break;
 574
 575   if(second-first>1)
 576     random_shuffle(first,second);
 577
 578   // now shuffle the additional records
 579   for(first=second;first!=rrs.end();++first)
 580     if(first->d_place==DNSResourceRecord::ADDITIONAL && first->d_type != QType::CNAME) // CNAME must come first
 581       break;
 582   for(second=first; second!=rrs.end(); ++second)
 583     if(second->d_place!=DNSResourceRecord::ADDITIONAL)
 584       break;
 585
 586   if(second-first>1)
 587     random_shuffle(first,second);
 588
 589   // we don't shuffle the rest
 590 }
 591
 592 static uint16_t mapTypesToOrder(uint16_t type)
 593 {
 594   if(type == QType::CNAME)
 595     return 0;
 596   if(type == QType::RRSIG)
 597     return 65535;
 598   else
 599     return 1;
 600 }
 601
 602 // make sure rrs is sorted in d_place order to avoid surprises later
 603 // then shuffle the parts that desire shuffling
 604 void orderAndShuffle(vector<DNSRecord>& rrs)
 605 {
 606   std::stable_sort(rrs.begin(), rrs.end(), [](const DNSRecord&a, const DNSRecord& b) {
 607       return std::make_tuple(a.d_place, mapTypesToOrder(a.d_type)) < std::make_tuple(b.d_place, mapTypesToOrder(b.d_type));
 608     });
 609   shuffle(rrs);
 610 }
 611
 612 void normalizeTV(struct timeval& tv)
 613 {
 614   if(tv.tv_usec > 1000000) {
 615     ++tv.tv_sec;
 616     tv.tv_usec-=1000000;
 617   }
 618   else if(tv.tv_usec < 0) {
 619     --tv.tv_sec;
 620     tv.tv_usec+=1000000;
 621   }
 622 }
 623
 624 const struct timeval operator+(const struct timeval& lhs, const struct timeval& rhs)
 625 {
 626   struct timeval ret;
 627   ret.tv_sec=lhs.tv_sec + rhs.tv_sec;
 628   ret.tv_usec=lhs.tv_usec + rhs.tv_usec;
 629   normalizeTV(ret);
 630   return ret;
 631 }
 632
 633 const struct timeval operator-(const struct timeval& lhs, const struct timeval& rhs)
 634 {
 635   struct timeval ret;
 636   ret.tv_sec=lhs.tv_sec - rhs.tv_sec;
 637   ret.tv_usec=lhs.tv_usec - rhs.tv_usec;
 638   normalizeTV(ret);
 639   return ret;
 640 }
 641
 642 pair<string, string> splitField(const string& inp, char sepa)
 643 {
 644   pair<string, string> ret;
 645   string::size_type cpos=inp.find(sepa);
 646   if(cpos==string::npos)
 647     ret.first=inp;
 648   else {
 649     ret.first=inp.substr(0, cpos);
 650     ret.second=inp.substr(cpos+1);
 651   }
 652   return ret;
 653 }
 654
 655 int logFacilityToLOG(unsigned int facility)
 656 {
 657   switch(facility) {
 658   case 0:
 659     return LOG_LOCAL0;
 660   case 1:
 661     return(LOG_LOCAL1);
 662   case 2:
 663     return(LOG_LOCAL2);
 664   case 3:
 665     return(LOG_LOCAL3);
 666   case 4:
 667     return(LOG_LOCAL4);
 668   case 5:
 669     return(LOG_LOCAL5);
 670   case 6:
 671     return(LOG_LOCAL6);
 672   case 7:
 673     return(LOG_LOCAL7);
 674   default:
 675     return -1;
 676   }
 677 }
 678
 679 string stripDot(const string& dom)
 680 {
 681   if(dom.empty())
 682     return dom;
 683
 684   if(dom[dom.size()-1]!='.')
 685     return dom;
 686
 687   return dom.substr(0,dom.size()-1);
 688 }
 689
 690
 691
 692 int makeIPv6sockaddr(const std::string& addr, struct sockaddr_in6* ret)
 693 {
 694   if(addr.empty())
 695     return -1;
 696   string ourAddr(addr);
 697   int port = -1;
 698   if(addr[0]=='[') { // [::]:53 style address
 699     string::size_type pos = addr.find(']');
 700     if(pos == string::npos || pos + 2 > addr.size() || addr[pos+1]!=':')
 701       return -1;
 702     ourAddr.assign(addr.c_str() + 1, pos-1);
 703     try {
 704       port = pdns_stou(addr.substr(pos+2));
 705     }
 706     catch(std::out_of_range) {
 707       return -1;
 708     }
 709   }
 710   ret->sin6_scope_id=0;
 711   ret->sin6_family=AF_INET6;
 712
 713   if(inet_pton(AF_INET6, ourAddr.c_str(), (void*)&ret->sin6_addr) != 1) {
 714     struct addrinfo* res;
 715     struct addrinfo hints;
 716     memset(&hints, 0, sizeof(hints));
 717
 718     hints.ai_family = AF_INET6;
 719     hints.ai_flags = AI_NUMERICHOST;
 720
 721     int error;
 722     if((error=getaddrinfo(ourAddr.c_str(), 0, &hints, &res))) { // this is correct
 723       return -1;
 724     }
 725
 726     memcpy(ret, res->ai_addr, res->ai_addrlen);
 727     freeaddrinfo(res);
 728   }
 729
 730   if(port > 65535)
 731     // negative ports are found with the pdns_stou above
 732     return -1;
 733
 734   if(port >= 0)
 735     ret->sin6_port = htons(port);
 736
 737   return 0;
 738 }
 739
 740 int makeIPv4sockaddr(const std::string& str, struct sockaddr_in* ret)
 741 {
 742   if(str.empty()) {
 743     return -1;
 744   }
 745   struct in_addr inp;
 746
 747   string::size_type pos = str.find(':');
 748   if(pos == string::npos) { // no port specified, not touching the port
 749     if(inet_aton(str.c_str(), &inp)) {
 750       ret->sin_addr.s_addr=inp.s_addr;
 751       return 0;
 752     }
 753     return -1;
 754   }
 755   if(!*(str.c_str() + pos + 1)) // trailing :
 756     return -1;
 757
 758   char *eptr = (char*)str.c_str() + str.size();
 759   int port = strtol(str.c_str() + pos + 1, &eptr, 10);
 760   if (port < 0 || port > 65535)
 761     return -1;
 762
 763   if(*eptr)
 764     return -1;
 765
 766   ret->sin_port = htons(port);
 767   if(inet_aton(str.substr(0, pos).c_str(), &inp)) {
 768     ret->sin_addr.s_addr=inp.s_addr;
 769     return 0;
 770   }
 771   return -1;
 772 }
 773
 774 int makeUNsockaddr(const std::string& path, struct sockaddr_un* ret)
 775 {
 776   if (path.empty())
 777     return -1;
 778
 779   memset(ret, 0, sizeof(struct sockaddr_un));
 780   ret->sun_family = AF_UNIX;
 781   if (path.length() >= sizeof(ret->sun_path))
 782     return -1;
 783
 784   path.copy(ret->sun_path, sizeof(ret->sun_path), 0);
 785   return 0;
 786 }
 787
 788 //! read a line of text from a FILE* to a std::string, returns false on 'no data'
 789 bool stringfgets(FILE* fp, std::string& line)
 790 {
 791   char buffer[1024];
 792   line.clear();
 793
 794   do {
 795     if(!fgets(buffer, sizeof(buffer), fp))
 796       return !line.empty();
 797
 798     line.append(buffer);
 799   } while(!strchr(buffer, '\n'));
 800   return true;
 801 }
 802
 803 bool readFileIfThere(const char* fname, std::string* line)
 804 {
 805   line->clear();
 806   FILE* fp = fopen(fname, "r");
 807   if(!fp)
 808     return false;
 809   stringfgets(fp, *line);
 810   fclose(fp);
 811   return true;
 812 }
 813
 814 Regex::Regex(const string &expr)
 815 {
 816   if(regcomp(&d_preg, expr.c_str(), REG_ICASE|REG_NOSUB|REG_EXTENDED))
 817     throw PDNSException("Regular expression did not compile");
 818 }
 819
 820 // if you end up here because valgrind told you were are doing something wrong
 821 // with msgh->msg_controllen, please refer to https://github.com/PowerDNS/pdns/pull/3962
 822 // first.
 823 void addCMsgSrcAddr(struct msghdr* msgh, void* cmsgbuf, const ComboAddress* source, int itfIndex)
 824 {
 825   struct cmsghdr *cmsg = NULL;
 826
 827   if(source->sin4.sin_family == AF_INET6) {
 828     struct in6_pktinfo *pkt;
 829
 830     msgh->msg_control = cmsgbuf;
 831     msgh->msg_controllen = CMSG_SPACE(sizeof(*pkt));
 832
 833     cmsg = CMSG_FIRSTHDR(msgh);
 834     cmsg->cmsg_level = IPPROTO_IPV6;
 835     cmsg->cmsg_type = IPV6_PKTINFO;
 836     cmsg->cmsg_len = CMSG_LEN(sizeof(*pkt));
 837
 838     pkt = (struct in6_pktinfo *) CMSG_DATA(cmsg);
 839     memset(pkt, 0, sizeof(*pkt));
 840     pkt->ipi6_addr = source->sin6.sin6_addr;
 841     pkt->ipi6_ifindex = itfIndex;
 842   }
 843   else {
 844 #ifdef IP_PKTINFO
 845     struct in_pktinfo *pkt;
 846
 847     msgh->msg_control = cmsgbuf;
 848     msgh->msg_controllen = CMSG_SPACE(sizeof(*pkt));
 849
 850     cmsg = CMSG_FIRSTHDR(msgh);
 851     cmsg->cmsg_level = IPPROTO_IP;
 852     cmsg->cmsg_type = IP_PKTINFO;
 853     cmsg->cmsg_len = CMSG_LEN(sizeof(*pkt));
 854
 855     pkt = (struct in_pktinfo *) CMSG_DATA(cmsg);
 856     memset(pkt, 0, sizeof(*pkt));
 857     pkt->ipi_spec_dst = source->sin4.sin_addr;
 858     pkt->ipi_ifindex = itfIndex;
 859 #endif
 860 #ifdef IP_SENDSRCADDR
 861     struct in_addr *in;
 862
 863     msgh->msg_control = cmsgbuf;
 864     msgh->msg_controllen = CMSG_SPACE(sizeof(*in));
 865
 866     cmsg = CMSG_FIRSTHDR(msgh);
 867     cmsg->cmsg_level = IPPROTO_IP;
 868     cmsg->cmsg_type = IP_SENDSRCADDR;
 869     cmsg->cmsg_len = CMSG_LEN(sizeof(*in));
 870
 871     in = (struct in_addr *) CMSG_DATA(cmsg);
 872     *in = source->sin4.sin_addr;
 873 #endif
 874   }
 875 }
 876
 877 unsigned int getFilenumLimit(bool hardOrSoft)
 878 {
 879   struct rlimit rlim;
 880   if(getrlimit(RLIMIT_NOFILE, &rlim) < 0)
 881     unixDie("Requesting number of available file descriptors");
 882   return hardOrSoft ? rlim.rlim_max : rlim.rlim_cur;
 883 }
 884
 885 void setFilenumLimit(unsigned int lim)
 886 {
 887   struct rlimit rlim;
 888
 889   if(getrlimit(RLIMIT_NOFILE, &rlim) < 0)
 890     unixDie("Requesting number of available file descriptors");
 891   rlim.rlim_cur=lim;
 892   if(setrlimit(RLIMIT_NOFILE, &rlim) < 0)
 893     unixDie("Setting number of available file descriptors");
 894 }
 895
 896 #define burtlemix(a,b,c) \
 897 { \
 898   a -= b; a -= c; a ^= (c>>13); \
 899   b -= c; b -= a; b ^= (a<<8); \
 900   c -= a; c -= b; c ^= (b>>13); \
 901   a -= b; a -= c; a ^= (c>>12);  \
 902   b -= c; b -= a; b ^= (a<<16); \
 903   c -= a; c -= b; c ^= (b>>5); \
 904   a -= b; a -= c; a ^= (c>>3);  \
 905   b -= c; b -= a; b ^= (a<<10); \
 906   c -= a; c -= b; c ^= (b>>15); \
 907 }
 908
 909 uint32_t burtle(const unsigned char* k, uint32_t length, uint32_t initval)
 910 {
 911   uint32_t a,b,c,len;
 912
 913    /* Set up the internal state */
 914   len = length;
 915   a = b = 0x9e3779b9;  /* the golden ratio; an arbitrary value */
 916   c = initval;         /* the previous hash value */
 917
 918   /*---------------------------------------- handle most of the key */
 919   while (len >= 12) {
 920     a += (k[0] +((uint32_t)k[1]<<8) +((uint32_t)k[2]<<16) +((uint32_t)k[3]<<24));
 921     b += (k[4] +((uint32_t)k[5]<<8) +((uint32_t)k[6]<<16) +((uint32_t)k[7]<<24));
 922     c += (k[8] +((uint32_t)k[9]<<8) +((uint32_t)k[10]<<16)+((uint32_t)k[11]<<24));
 923     burtlemix(a,b,c);
 924     k += 12; len -= 12;
 925   }
 926
 927   /*------------------------------------- handle the last 11 bytes */
 928   c += length;
 929   switch(len) {             /* all the case statements fall through */
 930   case 11: c+=((uint32_t)k[10]<<24);
 931   case 10: c+=((uint32_t)k[9]<<16);
 932   case 9 : c+=((uint32_t)k[8]<<8);
 933     /* the first byte of c is reserved for the length */
 934   case 8 : b+=((uint32_t)k[7]<<24);
 935   case 7 : b+=((uint32_t)k[6]<<16);
 936   case 6 : b+=((uint32_t)k[5]<<8);
 937   case 5 : b+=k[4];
 938   case 4 : a+=((uint32_t)k[3]<<24);
 939   case 3 : a+=((uint32_t)k[2]<<16);
 940   case 2 : a+=((uint32_t)k[1]<<8);
 941   case 1 : a+=k[0];
 942     /* case 0: nothing left to add */
 943   }
 944   burtlemix(a,b,c);
 945   /*-------------------------------------------- report the result */
 946   return c;
 947 }
 948
 949 uint32_t burtleCI(const unsigned char* k, uint32_t length, uint32_t initval)
 950 {
 951   uint32_t a,b,c,len;
 952
 953    /* Set up the internal state */
 954   len = length;
 955   a = b = 0x9e3779b9;  /* the golden ratio; an arbitrary value */
 956   c = initval;         /* the previous hash value */
 957
 958   /*---------------------------------------- handle most of the key */
 959   while (len >= 12) {
 960     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));
 961     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));
 962     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));
 963     burtlemix(a,b,c);
 964     k += 12; len -= 12;
 965   }
 966
 967   /*------------------------------------- handle the last 11 bytes */
 968   c += length;
 969   switch(len) {             /* all the case statements fall through */
 970   case 11: c+=((uint32_t)dns_tolower(k[10])<<24);
 971   case 10: c+=((uint32_t)dns_tolower(k[9])<<16);
 972   case 9 : c+=((uint32_t)dns_tolower(k[8])<<8);
 973     /* the first byte of c is reserved for the length */
 974   case 8 : b+=((uint32_t)dns_tolower(k[7])<<24);
 975   case 7 : b+=((uint32_t)dns_tolower(k[6])<<16);
 976   case 6 : b+=((uint32_t)dns_tolower(k[5])<<8);
 977   case 5 : b+=dns_tolower(k[4]);
 978   case 4 : a+=((uint32_t)dns_tolower(k[3])<<24);
 979   case 3 : a+=((uint32_t)dns_tolower(k[2])<<16);
 980   case 2 : a+=((uint32_t)dns_tolower(k[1])<<8);
 981   case 1 : a+=dns_tolower(k[0]);
 982     /* case 0: nothing left to add */
 983   }
 984   burtlemix(a,b,c);
 985   /*-------------------------------------------- report the result */
 986   return c;
 987 }
 988
 989
 990 bool setSocketTimestamps(int fd)
 991 {
 992 #ifdef SO_TIMESTAMP
 993   int on=1;
 994   return setsockopt(fd, SOL_SOCKET, SO_TIMESTAMP, (char*)&on, sizeof(on)) == 0;
 995 #endif
 996   return true; // we pretend this happened.
 997 }
 998
 999 bool setTCPNoDelay(int sock)
1000 {
1001   int flag = 1;
1002   return setsockopt(sock,            /* socket affected */
1003                     IPPROTO_TCP,     /* set option at TCP level */
1004                     TCP_NODELAY,     /* name of option */
1005                     (char *) &flag,  /* the cast is historical cruft */
1006                     sizeof(flag)) == 0;    /* length of option value */
1007 }
1008
1009
1010 bool setNonBlocking(int sock)
1011 {
1012   int flags=fcntl(sock,F_GETFL,0);
1013   if(flags<0 || fcntl(sock, F_SETFL,flags|O_NONBLOCK) <0)
1014     return false;
1015   return true;
1016 }
1017
1018 bool setBlocking(int sock)
1019 {
1020   int flags=fcntl(sock,F_GETFL,0);
1021   if(flags<0 || fcntl(sock, F_SETFL,flags&(~O_NONBLOCK)) <0)
1022     return false;
1023   return true;
1024 }
1025
1026 bool isNonBlocking(int sock)
1027 {
1028   int flags=fcntl(sock,F_GETFL,0);
1029   return flags & O_NONBLOCK;
1030 }
1031
1032 // Closes a socket.
1033 int closesocket( int socket )
1034 {
1035   int ret=::close(socket);
1036   if(ret < 0 && errno == ECONNRESET) // see ticket 192, odd BSD behaviour
1037     return 0;
1038   if(ret < 0)
1039     throw PDNSException("Error closing socket: "+stringerror());
1040   return ret;
1041 }
1042
1043 bool setCloseOnExec(int sock)
1044 {
1045   int flags=fcntl(sock,F_GETFD,0);
1046   if(flags<0 || fcntl(sock, F_SETFD,flags|FD_CLOEXEC) <0)
1047     return false;
1048   return true;
1049 }
1050
1051 string getMACAddress(const ComboAddress& ca)
1052 {
1053   string ret;
1054 #ifdef __linux__
1055   ifstream ifs("/proc/net/arp");
1056   if(!ifs)
1057     return ret;
1058   string line;
1059   string match=ca.toString()+' ';
1060   while(getline(ifs, line)) {
1061     if(boost::starts_with(line, match)) {
1062       vector<string> parts;
1063       stringtok(parts, line, " \n\t\r");
1064       if(parts.size() < 4)
1065         return ret;
1066       unsigned int tmp[6];
1067       sscanf(parts[3].c_str(), "%02x:%02x:%02x:%02x:%02x:%02x", tmp, tmp+1, tmp+2, tmp+3, tmp+4, tmp+5);
1068       for(int i = 0 ; i< 6 ; ++i)
1069         ret.append(1, (char)tmp[i]);
1070       return ret;
1071     }
1072   }
1073 #endif
1074   return ret;
1075 }
1076
1077 uint64_t udpErrorStats(const std::string& str)
1078 {
1079 #ifdef __linux__
1080   ifstream ifs("/proc/net/snmp");
1081   if(!ifs)
1082     return 0;
1083   string line;
1084   vector<string> parts;
1085   while(getline(ifs,line)) {
1086     if(boost::starts_with(line, "Udp: ") && isdigit(line[5])) {
1087       stringtok(parts, line, " \n\t\r");
1088       if(parts.size() < 7)
1089         break;
1090       if(str=="udp-rcvbuf-errors")
1091         return std::stoull(parts[5]);
1092       else if(str=="udp-sndbuf-errors")
1093         return std::stoull(parts[6]);
1094       else if(str=="udp-noport-errors")
1095         return std::stoull(parts[2]);
1096       else if(str=="udp-in-errors")
1097         return std::stoull(parts[3]);
1098       else
1099         return 0;
1100     }
1101   }
1102 #endif
1103   return 0;
1104 }
1105
1106 bool getTSIGHashEnum(const DNSName& algoName, TSIGHashEnum& algoEnum)
1107 {
1108   if (algoName == DNSName("hmac-md5.sig-alg.reg.int") || algoName == DNSName("hmac-md5"))
1109     algoEnum = TSIG_MD5;
1110   else if (algoName == DNSName("hmac-sha1"))
1111     algoEnum = TSIG_SHA1;
1112   else if (algoName == DNSName("hmac-sha224"))
1113     algoEnum = TSIG_SHA224;
1114   else if (algoName == DNSName("hmac-sha256"))
1115     algoEnum = TSIG_SHA256;
1116   else if (algoName == DNSName("hmac-sha384"))
1117     algoEnum = TSIG_SHA384;
1118   else if (algoName == DNSName("hmac-sha512"))
1119     algoEnum = TSIG_SHA512;
1120   else if (algoName == DNSName("gss-tsig"))
1121     algoEnum = TSIG_GSS;
1122   else {
1123      return false;
1124   }
1125   return true;
1126 }
1127
1128 DNSName getTSIGAlgoName(TSIGHashEnum& algoEnum)
1129 {
1130   switch(algoEnum) {
1131   case TSIG_MD5: return DNSName("hmac-md5.sig-alg.reg.int.");
1132   case TSIG_SHA1: return DNSName("hmac-sha1.");
1133   case TSIG_SHA224: return DNSName("hmac-sha224.");
1134   case TSIG_SHA256: return DNSName("hmac-sha256.");
1135   case TSIG_SHA384: return DNSName("hmac-sha384.");
1136   case TSIG_SHA512: return DNSName("hmac-sha512.");
1137   case TSIG_GSS: return DNSName("gss-tsig.");
1138   }
1139   throw PDNSException("getTSIGAlgoName does not understand given algorithm, please fix!");
1140 }
1141
1142 uint64_t getOpenFileDescriptors(const std::string&)
1143 {
1144 #ifdef __linux__
1145   DIR* dirhdl=opendir(("/proc/"+std::to_string(getpid())+"/fd/").c_str());
1146   if(!dirhdl)
1147     return 0;
1148
1149   struct dirent *entry;
1150   int ret=0;
1151   while((entry = readdir(dirhdl))) {
1152     uint32_t num;
1153     try {
1154       num = pdns_stou(entry->d_name);
1155     } catch (...) {
1156       continue; // was not a number.
1157     }
1158     if(std::to_string(num) == entry->d_name)
1159       ret++;
1160   }
1161   closedir(dirhdl);
1162   return ret;
1163
1164 #else
1165   return 0;
1166 #endif
1167 }
1168
1169 uint64_t getRealMemoryUsage(const std::string&)
1170 {
1171 #ifdef __linux__
1172   ifstream ifs("/proc/"+std::to_string(getpid())+"/smaps");
1173   if(!ifs)
1174     return 0;
1175   string line;
1176   uint64_t bytes=0;
1177   string header("Private_Dirty:");
1178   while(getline(ifs, line)) {
1179     if(boost::starts_with(line, header)) {
1180       bytes += std::stoull(line.substr(header.length() + 1))*1024;
1181     }
1182   }
1183   return bytes;
1184 #else
1185   return 0;
1186 #endif
1187 }
1188
1189 uint64_t getCPUTimeUser(const std::string&)
1190 {
1191   struct rusage ru;
1192   getrusage(RUSAGE_SELF, &ru);
1193   return (ru.ru_utime.tv_sec*1000ULL + ru.ru_utime.tv_usec/1000);
1194 }
1195
1196 uint64_t getCPUTimeSystem(const std::string&)
1197 {
1198   struct rusage ru;
1199   getrusage(RUSAGE_SELF, &ru);
1200   return (ru.ru_stime.tv_sec*1000ULL + ru.ru_stime.tv_usec/1000);
1201 }
1202
1203 double DiffTime(const struct timespec& first, const struct timespec& second)
1204 {
1205   int seconds=second.tv_sec - first.tv_sec;
1206   int nseconds=second.tv_nsec - first.tv_nsec;
1207
1208   if(nseconds < 0) {
1209     seconds-=1;
1210     nseconds+=1000000000;
1211   }
1212   return seconds + nseconds/1000000000.0;
1213 }
1214
1215 double DiffTime(const struct timeval& first, const struct timeval& second)
1216 {
1217   int seconds=second.tv_sec - first.tv_sec;
1218   int useconds=second.tv_usec - first.tv_usec;
1219
1220   if(useconds < 0) {
1221     seconds-=1;
1222     useconds+=1000000;
1223   }
1224   return seconds + useconds/1000000.0;
1225 }
1226
1227 uid_t strToUID(const string &str)
1228 {
1229   uid_t result = 0;
1230   const char * cstr = str.c_str();
1231   struct passwd * pwd = getpwnam(cstr);
1232
1233   if (pwd == NULL) {
1234     long long val;
1235
1236     try {
1237       val = stoll(str);
1238     }
1239     catch(std::exception& e) {
1240       throw runtime_error((boost::format("Error: Unable to parse user ID %s") % cstr).str() );
1241     }
1242
1243     if (val < std::numeric_limits<uid_t>::min() || val > std::numeric_limits<uid_t>::max()) {
1244       throw runtime_error((boost::format("Error: Unable to parse user ID %s") % cstr).str() );
1245     }
1246
1247     result = static_cast<uid_t>(val);
1248   }
1249   else {
1250     result = pwd->pw_uid;
1251   }
1252
1253   return result;
1254 }
1255
1256 gid_t strToGID(const string &str)
1257 {
1258   gid_t result = 0;
1259   const char * cstr = str.c_str();
1260   struct group * grp = getgrnam(cstr);
1261
1262   if (grp == NULL) {
1263     long long val;
1264
1265     try {
1266       val = stoll(str);
1267     }
1268     catch(std::exception& e) {
1269       throw runtime_error((boost::format("Error: Unable to parse group ID %s") % cstr).str() );
1270     }
1271
1272     if (val < std::numeric_limits<gid_t>::min() || val > std::numeric_limits<gid_t>::max()) {
1273       throw runtime_error((boost::format("Error: Unable to parse group ID %s") % cstr).str() );
1274     }
1275
1276     result = static_cast<gid_t>(val);
1277   }
1278   else {
1279     result = grp->gr_gid;
1280   }
1281
1282   return result;
1283 }
1284
1285 unsigned int pdns_stou(const std::string& str, size_t * idx, int base)
1286 {
1287   if (str.empty()) return 0; // compability
1288   unsigned long result = std::stoul(str, idx, base);
1289   if (result > std::numeric_limits<unsigned int>::max()) {
1290     throw std::out_of_range("stou");
1291   }
1292   return static_cast<unsigned int>(result);
1293 }
1294