pdns/webserver.cc

   1 /*
   2     PowerDNS Versatile Database Driven Nameserver
   3     Copyright (C) 2002  PowerDNS.COM BV
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18 */
  19 #include "utility.hh"
  20 #include "webserver.hh"
  21 #include "session.hh"
  22 #include "misc.hh"
  23 #include <vector>
  24 #include "logger.hh"
  25 #include <stdio.h>
  26 #include "dns.hh"
  27
  28
  29 map<string,WebServer::HandlerFunction *>WebServer::d_functions;
  30 void *WebServer::d_that;
  31 string WebServer::d_password;
  32
  33 char WebServer::B64Decode1(char cInChar)
  34 {
  35   // The incoming character will be A-Z, a-z, 0-9, +, /, or =.
  36   // The idea is to quickly determine which grouping the
  37   // letter belongs to and return the associated value
  38   // without having to search the global encoding string
  39   // (the value we're looking for would be the resulting
  40   // index into that string).
  41   //
  42   // To do that, we'll play some tricks...
  43   unsigned char iIndex = '\0';
  44   switch ( cInChar ) {
  45   case '+':
  46     iIndex = 62;
  47     break;
  48
  49   case '/':
  50     iIndex = 63;
  51     break;
  52
  53   case '=':
  54     iIndex = 0;
  55     break;
  56
  57   default:
  58     // Must be 'A'-'Z', 'a'-'z', '0'-'9', or an error...
  59     //
  60     // Numerically, small letters are "greater" in value than
  61     // capital letters and numerals (ASCII value), and capital
  62     // letters are "greater" than numerals (again, ASCII value),
  63     // so we check for numerals first, then capital letters,
  64     // and finally small letters.
  65     iIndex = '9' - cInChar;
  66     if ( iIndex > 0x3F ) {
  67       // Not from '0' to '9'...
  68       iIndex = 'Z' - cInChar;
  69       if ( iIndex > 0x3F ) {
  70         // Not from 'A' to 'Z'...
  71         iIndex = 'z' - cInChar;
  72         if ( iIndex > 0x3F ) {
  73           // Invalid character...cannot
  74           // decode!
  75           iIndex = 0x80; // set the high bit
  76         } // if
  77         else {
  78           // From 'a' to 'z'
  79           iIndex = (('z' - iIndex) - 'a') + 26;
  80         } // else
  81       } // if
  82       else {
  83         // From 'A' to 'Z'
  84         iIndex = ('Z' - iIndex) - 'A';
  85       } // else
  86     } // if
  87     else {
  88       // Adjust the index...
  89       iIndex = (('9' - iIndex) - '0') + 52;
  90     } // else
  91     break;
  92
  93   } // switch
  94
  95   return iIndex;
  96 }
  97
  98 int WebServer::B64Decode(const std::string& strInput, std::string& strOutput)
  99 {
 100   // Set up a decoding buffer
 101   long cBuf = 0;
 102   char* pBuf = (char*)&cBuf;
 103
 104   // Decoding management...
 105   short iBitGroup = 0, iInNum = 0;
 106
 107   // While there are characters to process...
 108   //
 109   // We'll decode characters in blocks of 4, as
 110   // there are 4 groups of 6 bits in 3 bytes. The
 111   // incoming Base64 character is first decoded, and
 112   // then it is inserted into the decode buffer
 113   // (with any relevant shifting, as required).
 114   // Later, after all 3 bytes have been reconsituted,
 115   // we assign them to the output string, ultimately
 116   // to be returned as the original message.
 117   int iInSize = strInput.size();
 118   unsigned char cChar = '\0';
 119   while ( iInNum < iInSize ) {
 120     // Fill the decode buffer with 4 groups of 6 bits
 121     cBuf = 0; // clear
 122     for ( iBitGroup = 0; iBitGroup < 4; ++iBitGroup ) {
 123       if ( iInNum < iInSize ) {
 124         // Decode a character
 125         cChar = B64Decode1(strInput.at(iInNum++));
 126       } // if
 127       else {
 128         // Decode a padded zero
 129         cChar = '\0';
 130       } // else
 131
 132       // Check for valid decode
 133       if ( cChar > 0x7F )
 134         return -1;
 135
 136       // Adjust the bits
 137       switch ( iBitGroup ) {
 138       case 0:
 139         // The first group is copied into
 140         // the least significant 6 bits of
 141         // the decode buffer...these 6 bits
 142         // will eventually shift over to be
 143         // the most significant bits of the
 144         // third byte.
 145         cBuf = cBuf | cChar;
 146         break;
 147
 148       default:
 149         // For groupings 1-3, simply shift
 150         // the bits in the decode buffer over
 151         // by 6 and insert the 6 from the
 152         // current decode character.
 153         cBuf = (cBuf << 6) | cChar;
 154         break;
 155
 156       } // switch
 157     } // for
 158
 159     // Interpret the resulting 3 bytes...note there
 160     // may have been padding, so those padded bytes
 161     // are actually ignored.
 162     strOutput += pBuf[2];
 163     strOutput += pBuf[1];
 164     strOutput += pBuf[0];
 165   } // while
 166
 167   return 1;
 168 }
 169
 170
 171
 172
 173 void WebServer::registerHandler(const string&s, HandlerFunction *ptr)
 174 {
 175   d_functions[s]=ptr;
 176 }
 177
 178 void WebServer::setCaller(void *that)
 179 {
 180   d_that=that;
 181 }
 182
 183 void *WebServer::serveConnection(void *p)
 184 {
 185   Session *client=static_cast<Session *>(p);
 186   try {
 187     string line;
 188     client->getLine(line);
 189     stripLine(line);
 190     //    L<<"page: "<<line<<endl;
 191
 192     vector<string> parts;
 193     stringtok(parts,line);
 194
 195     string uri;
 196     if(parts.size()>1)
 197       uri=parts[1];
 198
 199     vector<string>variables;
 200
 201     parts.clear();
 202     stringtok(parts,uri,"?");
 203
 204     //    L<<"baseUrl: '"<<parts[0]<<"'"<<endl;
 205
 206     vector<string>urlParts;
 207     stringtok(urlParts,parts[0],"/");
 208     string baseUrl;
 209     if(urlParts.empty())
 210       baseUrl="";
 211     else
 212       baseUrl=urlParts[0];
 213
 214     //    L<<"baseUrl real: '"<<baseUrl<<"'"<<endl;
 215
 216     if(parts.size()>1) {
 217       stringtok(variables,parts[1],"&");
 218     }
 219
 220     map<string,string>varmap;
 221
 222     for(vector<string>::const_iterator i=variables.begin();
 223         i!=variables.end();++i) {
 224
 225       parts.clear();
 226       stringtok(parts,*i,"=");
 227       if(parts.size()>1)
 228         varmap[parts[0]]=parts[1];
 229       else
 230         varmap[parts[0]]="";
 231
 232       L<<"'"<<parts[0]<<"' = '"<<varmap[parts[0]]<<"'"<<endl;
 233     }
 234
 235     bool authOK=0;
 236
 237     // read & ignore other lines
 238     do {
 239       client->getLine(line);
 240       stripLine(line);
 241
 242       if(!line.find("Authorization: Basic ")) {
 243         string cookie=line.substr(21);
 244         string plain;
 245
 246         B64Decode(cookie,plain);
 247         vector<string>cparts;
 248         stringtok(cparts,plain,":");
 249
 250         if(cparts.size()==2 && !strcmp(cparts[1].c_str(),d_password.c_str())) { // this gets rid of terminating zeros
 251           authOK=1;
 252         }
 253       }
 254     }while(!line.empty());
 255
 256
 257     if(!d_password.empty() && !authOK) {
 258       client->putLine("HTTP/1.1 401 OK\n");
 259       client->putLine("WWW-Authenticate: Basic realm=\"PowerDNS\"\n");
 260
 261       client->putLine("Connection: close\n");
 262       client->putLine("Content-type: text/html\n\n");
 263       client->putLine("Please enter a valid password!\n");
 264       client->close();
 265       delete client;
 266       return 0;
 267     }
 268
 269     HandlerFunction *fptr;
 270     if((fptr=d_functions[baseUrl])) {
 271
 272       bool custom;
 273       string ret=(*fptr)(varmap, d_that, &custom);
 274
 275       if(!custom) {
 276         client->putLine("HTTP/1.1 200 OK\n");
 277         client->putLine("Connection: close\n");
 278         client->putLine("Content-type: text/html\n\n");
 279       }
 280       client->putLine(ret);
 281     }
 282     else {
 283       client->putLine("HTTP/1.1 404 Not found\n");
 284       client->putLine("Connection: close\n");
 285       client->putLine("Content-type: text/html\n\n");
 286       // FIXME: CSS problem?
 287       client->putLine("<html><body><h1>Did not find file '"+baseUrl+"'</body></html>\n");
 288     }
 289
 290     client->close();
 291     delete client;
 292     client=0;
 293     return 0;
 294
 295   }
 296   catch(SessionTimeoutException &e) {
 297     L<<Logger::Error<<"Timeout in webserver"<<endl;
 298   }
 299   catch(SessionException &e) {
 300     L<<Logger::Error<<"Fatal error in webserver: "<<e.reason<<endl;
 301   }
 302   catch(Exception &e) {
 303     L<<Logger::Error<<"Exception in webserver: "<<e.reason<<endl;
 304   }
 305   catch(exception &e) {
 306     L<<Logger::Error<<"STL Exception in webserver: "<<e.what()<<endl;
 307   }
 308   catch(...) {
 309     L<<Logger::Error<<"Unknown exception in webserver"<<endl;
 310   }
 311   if(client) {
 312     client->close();
 313     delete client;
 314     client=0;
 315   }
 316   return 0;
 317 }
 318
 319 WebServer::WebServer(const string &listenaddress, int port, const string &password)
 320 {
 321   d_listenaddress=listenaddress;
 322   d_port=port;
 323   d_password=password;
 324 }
 325
 326 void WebServer::go()
 327 {
 328   try {
 329     Server *s=new Server(d_port, d_listenaddress);
 330
 331     Session *client;
 332     pthread_t tid;
 333
 334     L<<Logger::Error<<"Launched webserver on "<<d_listenaddress<<":"<<d_port<<endl;
 335
 336     while((client=s->accept())) {
 337       pthread_create(&tid, 0 , &serveConnection, (void *)client);
 338     }
 339   }
 340   catch(SessionTimeoutException &e) {
 341     L<<Logger::Error<<"Timeout in webserver"<<endl;
 342   }
 343   catch(SessionException &e) {
 344     L<<Logger::Error<<"Fatal error in webserver: "<<e.reason<<endl;
 345   }
 346   catch(Exception &e) {
 347     L<<Logger::Error<<"Fatal error in main webserver thread: "<<e.reason<<endl;
 348   }
 349   catch(exception &e) {
 350     L<<Logger::Error<<"STL Exception in main webserver thread: "<<e.what()<<endl;
 351   }
 352   catch(...) {
 353     L<<Logger::Error<<"Unknown exception in main webserver thread"<<endl;
 354   }
 355   exit(1);
 356
 357 }