pdns/zoneparser-tng.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 "ascii.hh"
  26 #include "dnsparser.hh"
  27 #include "sstuff.hh"
  28 #include "misc.hh"
  29 #include "dnswriter.hh"
  30 #include "dnsrecords.hh"
  31 #include "misc.hh"
  32 #include <fstream>
  33 #include "dns.hh"
  34 #include "zoneparser-tng.hh"
  35 #include <deque>
  36 #include <boost/algorithm/string.hpp>
  37 #include <system_error>
  38
  39 static string g_INstr("IN");
  40
  41 ZoneParserTNG::ZoneParserTNG(const string& fname, const DNSName& zname, const string& reldir) : d_reldir(reldir),
  42                                                                                                d_zonename(zname), d_defaultttl(3600),
  43                                                                                                d_templatecounter(0), d_templatestop(0),
  44                                                                                                d_templatestep(0), d_havedollarttl(false){
  45   stackFile(fname);
  46 }
  47
  48 ZoneParserTNG::ZoneParserTNG(const vector<string> zonedata, const DNSName& zname):
  49   d_zonename(zname), d_zonedata(zonedata), d_defaultttl(3600),
  50   d_templatecounter(0), d_templatestop(0), d_templatestep(0),
  51   d_havedollarttl(false), d_fromfile(false)
  52 {
  53   d_zonedataline = d_zonedata.begin();
  54 }
  55
  56 void ZoneParserTNG::stackFile(const std::string& fname)
  57 {
  58   FILE *fp=fopen(fname.c_str(), "r");
  59   if(!fp) {
  60     std::error_code ec (errno,std::generic_category());
  61     throw std::system_error(ec, "Unable to open file '"+fname+"': "+stringerror());
  62   }
  63
  64   filestate fs(fp, fname);
  65   d_filestates.push(fs);
  66   d_fromfile = true;
  67 }
  68
  69 ZoneParserTNG::~ZoneParserTNG()
  70 {
  71   while(!d_filestates.empty()) {
  72     fclose(d_filestates.top().d_fp);
  73     d_filestates.pop();
  74   }
  75 }
  76
  77 static string makeString(const string& line, const pair<string::size_type, string::size_type>& range)
  78 {
  79   return string(line.c_str() + range.first, range.second - range.first);
  80 }
  81
  82 static bool isTimeSpec(const string& nextpart)
  83 {
  84   if(nextpart.empty())
  85     return false;
  86   for(string::const_iterator iter = nextpart.begin(); iter != nextpart.end(); ++iter) {
  87     if(isdigit(*iter))
  88       continue;
  89     if(iter+1 != nextpart.end())
  90       return false;
  91     char c=tolower(*iter);
  92     return (c=='s' || c=='m' || c=='h' || c=='d' || c=='w' || c=='y');
  93   }
  94   return true;
  95 }
  96
  97
  98 unsigned int ZoneParserTNG::makeTTLFromZone(const string& str)
  99 {
 100   if(str.empty())
 101     return 0;
 102
 103   unsigned int val;
 104   try {
 105     val=pdns_stou(str);
 106   }
 107   catch (const std::out_of_range& oor) {
 108     throw PDNSException("Unable to parse time specification '"+str+"' "+getLineOfFile());
 109   }
 110
 111   char lc=dns_tolower(str[str.length()-1]);
 112   if(!isdigit(lc))
 113     switch(lc) {
 114     case 's':
 115       break;
 116     case 'm':
 117       val*=60; // minutes, not months!
 118       break;
 119     case 'h':
 120       val*=3600;
 121       break;
 122     case 'd':
 123       val*=3600*24;
 124       break;
 125     case 'w':
 126       val*=3600*24*7;
 127       break;
 128     case 'y': // ? :-)
 129       val*=3600*24*365;
 130       break;
 131
 132     default:
 133       throw PDNSException("Unable to parse time specification '"+str+"' "+getLineOfFile());
 134     }
 135   return val;
 136 }
 137
 138 bool ZoneParserTNG::getTemplateLine()
 139 {
 140   if(d_templateparts.empty() || d_templatecounter > d_templatestop) // no template, or done with
 141     return false;
 142
 143   string retline;
 144   for(parts_t::const_iterator iter = d_templateparts.begin() ; iter != d_templateparts.end(); ++iter) {
 145     if(iter != d_templateparts.begin())
 146       retline+=" ";
 147
 148     string part=makeString(d_templateline, *iter);
 149
 150     /* a part can contain a 'naked' $, an escaped $ (\$), or ${offset,width,radix}, with width defaulting to 0,
 151        and radix being 'd', 'o', 'x' or 'X', defaulting to 'd'.
 152
 153        The width is zero-padded, so if the counter is at 1, the offset is 15, with is 3, and the radix is 'x',
 154        output will be '010', from the input of ${15,3,x}
 155     */
 156
 157     string outpart;
 158     outpart.reserve(part.size()+5);
 159     bool inescape=false;
 160
 161     for(string::size_type pos = 0; pos < part.size() ; ++pos) {
 162       char c=part[pos];
 163       if(inescape) {
 164         outpart.append(1, c);
 165         inescape=false;
 166         continue;
 167       }
 168
 169       if(part[pos]=='\\') {
 170         inescape=true;
 171         continue;
 172       }
 173       if(c=='$') {
 174         if(pos + 1 == part.size() || part[pos+1]!='{') {  // a trailing $, or not followed by {
 175           outpart.append(std::to_string(d_templatecounter));
 176           continue;
 177         }
 178
 179         // need to deal with { case
 180
 181         pos+=2;
 182         string::size_type startPos=pos;
 183         for(; pos < part.size() && part[pos]!='}' ; ++pos)
 184           ;
 185
 186         if(pos == part.size()) // partial spec
 187           break;
 188
 189         // we are on the '}'
 190
 191         string spec(part.c_str() + startPos, part.c_str() + pos);
 192         int offset=0, width=0;
 193         char radix='d';
 194         sscanf(spec.c_str(), "%d,%d,%c", &offset, &width, &radix);  // parse format specifier
 195
 196         char sformat[12];
 197         snprintf(sformat, sizeof(sformat), "%%0%d%c", width, radix); // make into printf-style format
 198
 199         char tmp[80];
 200         snprintf(tmp, sizeof(tmp), sformat, d_templatecounter + offset); // and do the actual printing
 201         outpart+=tmp;
 202       }
 203       else
 204         outpart.append(1, c);
 205     }
 206     retline+=outpart;
 207   }
 208   d_templatecounter+=d_templatestep;
 209
 210   d_line = retline;
 211   return true;
 212 }
 213
 214 void chopComment(string& line)
 215 {
 216   if(line.find(';')==string::npos)
 217     return;
 218   string::size_type pos, len = line.length();
 219   bool inQuote=false;
 220   for(pos = 0 ; pos < len; ++pos) {
 221     if(line[pos]=='\\')
 222       pos++;
 223     else if(line[pos]=='"')
 224       inQuote=!inQuote;
 225     else if(line[pos]==';' && !inQuote)
 226       break;
 227   }
 228   if(pos != len)
 229     line.resize(pos);
 230 }
 231
 232 bool findAndElide(string& line, char c)
 233 {
 234   string::size_type pos, len = line.length();
 235   bool inQuote=false;
 236   for(pos = 0 ; pos < len; ++pos) {
 237     if(line[pos]=='\\')
 238       pos++;
 239     else if(line[pos]=='"')
 240       inQuote=!inQuote;
 241     else if(line[pos]==c && !inQuote)
 242       break;
 243   }
 244   if(pos != len) {
 245     line.erase(pos, 1);
 246     return true;
 247   }
 248   return false;
 249 }
 250
 251 DNSName ZoneParserTNG::getZoneName()
 252 {
 253   return d_zonename;
 254 }
 255
 256 string ZoneParserTNG::getLineOfFile()
 257 {
 258   if (d_zonedata.size() > 0)
 259     return "on line "+std::to_string(std::distance(d_zonedata.begin(), d_zonedataline))+" of given string";
 260
 261   if (d_filestates.empty())
 262     return "";
 263
 264   return "on line "+std::to_string(d_filestates.top().d_lineno)+" of file '"+d_filestates.top().d_filename+"'";
 265 }
 266
 267 pair<string,int> ZoneParserTNG::getLineNumAndFile()
 268 {
 269   if (d_filestates.empty())
 270     return {"", 0};
 271   else
 272     return {d_filestates.top().d_filename, d_filestates.top().d_lineno};
 273 }
 274
 275 bool ZoneParserTNG::get(DNSResourceRecord& rr, std::string* comment)
 276 {
 277  retry:;
 278   if(!getTemplateLine() && !getLine())
 279     return false;
 280
 281   boost::trim_right_if(d_line, is_any_of(" \t\r\n\x1a"));
 282   if(comment)
 283     comment->clear();
 284   if(comment && d_line.find(';') != string::npos)
 285     *comment = d_line.substr(d_line.find(';'));
 286   parts_t parts;
 287   vstringtok(parts, d_line);
 288
 289   if(parts.empty())
 290     goto retry;
 291
 292   if(parts[0].first != parts[0].second && d_line[parts[0].first]==';') // line consisting of nothing but comments
 293     goto retry;
 294
 295   if(d_line[0]=='$') {
 296     string command=makeString(d_line, parts[0]);
 297     if(pdns_iequals(command,"$TTL") && parts.size() > 1) {
 298       d_defaultttl=makeTTLFromZone(trim_right_copy_if(makeString(d_line, parts[1]), is_any_of(";")));
 299       d_havedollarttl=true;
 300     }
 301     else if(pdns_iequals(command,"$INCLUDE") && parts.size() > 1 && d_fromfile) {
 302       string fname=unquotify(makeString(d_line, parts[1]));
 303       if(!fname.empty() && fname[0]!='/' && !d_reldir.empty())
 304         fname=d_reldir+"/"+fname;
 305       stackFile(fname);
 306     }
 307     else if(pdns_iequals(command, "$ORIGIN") && parts.size() > 1) {
 308       d_zonename = DNSName(makeString(d_line, parts[1]));
 309     }
 310     else if(pdns_iequals(command, "$GENERATE") && parts.size() > 2) {
 311       // $GENERATE 1-127 $ CNAME $.0
 312       string range=makeString(d_line, parts[1]);
 313       d_templatestep=1;
 314       d_templatestop=0;
 315       sscanf(range.c_str(),"%u-%u/%u", &d_templatecounter, &d_templatestop, &d_templatestep);
 316       d_templateline=d_line;
 317       parts.pop_front();
 318       parts.pop_front();
 319
 320       d_templateparts=parts;
 321       goto retry;
 322     }
 323     else
 324       throw exception("Can't parse zone line '"+d_line+"' "+getLineOfFile());
 325     goto retry;
 326   }
 327
 328   bool prevqname=false;
 329   string qname = makeString(d_line, parts[0]); // Don't use DNSName here!
 330   if(dns_isspace(d_line[0])) {
 331     rr.qname=d_prevqname;
 332     prevqname=true;
 333   }else {
 334     rr.qname=DNSName(qname);
 335     parts.pop_front();
 336     if(qname.empty() || qname[0]==';')
 337       goto retry;
 338   }
 339   if(qname=="@")
 340     rr.qname=d_zonename;
 341   else if(!prevqname && !isCanonical(qname))
 342     rr.qname += d_zonename;
 343   d_prevqname=rr.qname;
 344
 345   if(parts.empty())
 346     throw exception("Line with too little parts "+getLineOfFile());
 347
 348   string nextpart;
 349
 350   rr.ttl=d_defaultttl;
 351   bool haveTTL=0, haveQTYPE=0;
 352   pair<string::size_type, string::size_type> range;
 353
 354   while(!parts.empty()) {
 355     range=parts.front();
 356     parts.pop_front();
 357     nextpart=makeString(d_line, range);
 358     if(nextpart.empty())
 359       break;
 360
 361     if(nextpart.find(';')!=string::npos) {
 362       break;
 363     }
 364
 365     // cout<<"Next part: '"<<nextpart<<"'"<<endl;
 366
 367     if(pdns_iequals(nextpart, g_INstr)) {
 368       // cout<<"Ignoring 'IN'\n";
 369       continue;
 370     }
 371     if(!haveTTL && !haveQTYPE && isTimeSpec(nextpart)) {
 372       rr.ttl=makeTTLFromZone(nextpart);
 373       if(!d_havedollarttl)
 374         d_defaultttl = rr.ttl;
 375       haveTTL=true;
 376       // cout<<"ttl is probably: "<<rr.ttl<<endl;
 377       continue;
 378     }
 379     if(haveQTYPE)
 380       break;
 381
 382     try {
 383       rr.qtype=DNSRecordContent::TypeToNumber(nextpart);
 384       // cout<<"Got qtype ("<<rr.qtype.getCode()<<")\n";
 385       haveQTYPE=1;
 386       continue;
 387     }
 388     catch(...) {
 389       throw runtime_error("Parsing zone content "+getLineOfFile()+
 390                           ": '"+nextpart+
 391                           "' doesn't look like a qtype, stopping loop");
 392     }
 393   }
 394   if(!haveQTYPE)
 395     throw exception("Malformed line "+getLineOfFile()+": '"+d_line+"'");
 396
 397   //  rr.content=d_line.substr(range.first);
 398   rr.content.assign(d_line, range.first, string::npos);
 399   chopComment(rr.content);
 400   trim_if(rr.content, is_any_of(" \r\n\t\x1a"));
 401
 402   if(rr.content.size()==1 && rr.content[0]=='@')
 403     rr.content=d_zonename.toString();
 404
 405   if(findAndElide(rr.content, '(')) {      // have found a ( and elided it
 406     if(!findAndElide(rr.content, ')')) {
 407       while(getLine()) {
 408         trim_right(d_line);
 409         chopComment(d_line);
 410         trim(d_line);
 411
 412         bool ended = findAndElide(d_line, ')');
 413         rr.content+=" "+d_line;
 414         if(ended)
 415           break;
 416       }
 417     }
 418   }
 419   trim_if(rr.content, is_any_of(" \r\n\t\x1a"));
 420
 421   vector<string> recparts;
 422   switch(rr.qtype.getCode()) {
 423   case QType::MX:
 424     stringtok(recparts, rr.content);
 425     if(recparts.size()==2) {
 426       if (recparts[1]!=".") {
 427         try {
 428           recparts[1] = toCanonic(d_zonename, recparts[1]).toStringRootDot();
 429         } catch (std::exception &e) {
 430           throw PDNSException("Error in record '" + rr.qname.toLogString() + " " + rr.qtype.getName() + "': " + e.what());
 431         }
 432       }
 433       rr.content=recparts[0]+" "+recparts[1];
 434     }
 435     break;
 436
 437   case QType::RP:
 438     stringtok(recparts, rr.content);
 439     if(recparts.size()==2) {
 440       recparts[0] = toCanonic(d_zonename, recparts[0]).toStringRootDot();
 441       recparts[1] = toCanonic(d_zonename, recparts[1]).toStringRootDot();
 442       rr.content=recparts[0]+" "+recparts[1];
 443     }
 444     break;
 445
 446   case QType::SRV:
 447     stringtok(recparts, rr.content);
 448     if(recparts.size()==4) {
 449       if(recparts[3]!=".") {
 450         try {
 451           recparts[3] = toCanonic(d_zonename, recparts[3]).toStringRootDot();
 452         } catch (std::exception &e) {
 453           throw PDNSException("Error in record '" + rr.qname.toLogString() + " " + rr.qtype.getName() + "': " + e.what());
 454         }
 455       }
 456       rr.content=recparts[0]+" "+recparts[1]+" "+recparts[2]+" "+recparts[3];
 457     }
 458     break;
 459
 460
 461   case QType::NS:
 462   case QType::CNAME:
 463   case QType::DNAME:
 464   case QType::PTR:
 465     try {
 466       rr.content = toCanonic(d_zonename, rr.content).toStringRootDot();
 467     } catch (std::exception &e) {
 468       throw PDNSException("Error in record '" + rr.qname.toLogString() + " " + rr.qtype.getName() + "': " + e.what());
 469     }
 470     break;
 471   case QType::AFSDB:
 472     stringtok(recparts, rr.content);
 473     if(recparts.size() == 2) {
 474       try {
 475         recparts[1]=toCanonic(d_zonename, recparts[1]).toStringRootDot();
 476       } catch (std::exception &e) {
 477         throw PDNSException("Error in record '" + rr.qname.toLogString() + " " + rr.qtype.getName() + "': " + e.what());
 478       }
 479     } else {
 480       throw PDNSException("AFSDB record for "+rr.qname.toLogString()+" invalid");
 481     }
 482     rr.content.clear();
 483     for(string::size_type n = 0; n < recparts.size(); ++n) {
 484       if(n)
 485         rr.content.append(1,' ');
 486
 487       rr.content+=recparts[n];
 488     }
 489     break;
 490   case QType::SOA:
 491     stringtok(recparts, rr.content);
 492     if(recparts.size() > 7)
 493       throw PDNSException("SOA record contents for "+rr.qname.toLogString()+" contains too many parts");
 494     if(recparts.size() > 1) {
 495       try {
 496         recparts[0]=toCanonic(d_zonename, recparts[0]).toStringRootDot();
 497         recparts[1]=toCanonic(d_zonename, recparts[1]).toStringRootDot();
 498       } catch (std::exception &e) {
 499         throw PDNSException("Error in record '" + rr.qname.toLogString() + " " + rr.qtype.getName() + "': " + e.what());
 500       }
 501     }
 502     rr.content.clear();
 503     for(string::size_type n = 0; n < recparts.size(); ++n) {
 504       if(n)
 505         rr.content.append(1,' ');
 506
 507       if(n > 1)
 508         rr.content+=std::to_string(makeTTLFromZone(recparts[n]));
 509       else
 510         rr.content+=recparts[n];
 511     }
 512     break;
 513   default:;
 514   }
 515   return true;
 516 }
 517
 518
 519 bool ZoneParserTNG::getLine()
 520 {
 521   if (d_zonedata.size() > 0) {
 522     if (d_zonedataline != d_zonedata.end()) {
 523       d_line = *d_zonedataline;
 524       ++d_zonedataline;
 525       return true;
 526     }
 527     return false;
 528   }
 529   while(!d_filestates.empty()) {
 530     if(stringfgets(d_filestates.top().d_fp, d_line)) {
 531       d_filestates.top().d_lineno++;
 532       return true;
 533     }
 534     fclose(d_filestates.top().d_fp);
 535     d_filestates.pop();
 536   }
 537   return false;
 538 }