pdns/webserver.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 "utility.hh"
  26 #include "webserver.hh"
  27 #include "misc.hh"
  28 #include <thread>
  29 #include "threadname.hh"
  30 #include <vector>
  31 #include "logger.hh"
  32 #include <stdio.h>
  33 #include "dns.hh"
  34 #include "base64.hh"
  35 #include "json.hh"
  36 #include "uuid-utils.hh"
  37 #include <yahttp/router.hpp>
  38
  39 json11::Json HttpRequest::json()
  40 {
  41   string err;
  42   if(this->body.empty()) {
  43     g_log<<Logger::Debug<<logprefix<<"JSON document expected in request body, but body was empty" << endl;
  44     throw HttpBadRequestException();
  45   }
  46   json11::Json doc = json11::Json::parse(this->body, err);
  47   if (doc.is_null()) {
  48     g_log<<Logger::Debug<<logprefix<<"parsing of JSON document failed:" << err << endl;
  49     throw HttpBadRequestException();
  50   }
  51   return doc;
  52 }
  53
  54 bool HttpRequest::compareAuthorization(const string &expected_password)
  55 {
  56   // validate password
  57   YaHTTP::strstr_map_t::iterator header = headers.find("authorization");
  58   bool auth_ok = false;
  59   if (header != headers.end() && toLower(header->second).find("basic ") == 0) {
  60     string cookie = header->second.substr(6);
  61
  62     string plain;
  63     B64Decode(cookie, plain);
  64
  65     vector<string> cparts;
  66     stringtok(cparts, plain, ":");
  67
  68     // this gets rid of terminating zeros
  69     auth_ok = (cparts.size()==2 && (0==strcmp(cparts[1].c_str(), expected_password.c_str())));
  70   }
  71   return auth_ok;
  72 }
  73
  74 bool HttpRequest::compareHeader(const string &header_name, const string &expected_value)
  75 {
  76   YaHTTP::strstr_map_t::iterator header = headers.find(header_name);
  77   if (header == headers.end())
  78     return false;
  79
  80   // this gets rid of terminating zeros
  81   return (0==strcmp(header->second.c_str(), expected_value.c_str()));
  82 }
  83
  84
  85 void HttpResponse::setBody(const json11::Json& document)
  86 {
  87   document.dump(this->body);
  88 }
  89
  90 void HttpResponse::setErrorResult(const std::string& message, const int status_)
  91 {
  92   setBody(json11::Json::object { { "error", message } });
  93   this->status = status_;
  94 }
  95
  96 void HttpResponse::setSuccessResult(const std::string& message, const int status_)
  97 {
  98   setBody(json11::Json::object { { "result", message } });
  99   this->status = status_;
 100 }
 101
 102 static void bareHandlerWrapper(WebServer::HandlerFunction handler, YaHTTP::Request* req, YaHTTP::Response* resp)
 103 {
 104   // wrapper to convert from YaHTTP::* to our subclasses
 105   handler(static_cast<HttpRequest*>(req), static_cast<HttpResponse*>(resp));
 106 }
 107
 108 void WebServer::registerBareHandler(const string& url, HandlerFunction handler)
 109 {
 110   YaHTTP::THandlerFunction f = boost::bind(&bareHandlerWrapper, handler, _1, _2);
 111   YaHTTP::Router::Any(url, f);
 112 }
 113
 114 static bool optionsHandler(HttpRequest* req, HttpResponse* resp) {
 115   if (req->method == "OPTIONS") {
 116     resp->headers["access-control-allow-origin"] = "*";
 117     resp->headers["access-control-allow-headers"] = "Content-Type, X-API-Key";
 118     resp->headers["access-control-allow-methods"] = "GET, POST, PUT, PATCH, DELETE, OPTIONS";
 119     resp->headers["access-control-max-age"] = "3600";
 120     resp->status = 200;
 121     resp->headers["content-type"]= "text/plain";
 122     resp->body = "";
 123     return true;
 124   }
 125   return false;
 126 }
 127
 128 static void apiWrapper(WebServer::HandlerFunction handler, HttpRequest* req, HttpResponse* resp, const string &apikey) {
 129   if (optionsHandler(req, resp)) return;
 130
 131   resp->headers["access-control-allow-origin"] = "*";
 132
 133   if (apikey.empty()) {
 134     g_log<<Logger::Error<<req->logprefix<<"HTTP API Request \"" << req->url.path << "\": Authentication failed, API Key missing in config" << endl;
 135     throw HttpUnauthorizedException("X-API-Key");
 136   }
 137   bool auth_ok = req->compareHeader("x-api-key", apikey) || req->getvars["api-key"] == apikey;
 138
 139   if (!auth_ok) {
 140     g_log<<Logger::Error<<req->logprefix<<"HTTP Request \"" << req->url.path << "\": Authentication by API Key failed" << endl;
 141     throw HttpUnauthorizedException("X-API-Key");
 142   }
 143
 144   resp->headers["Content-Type"] = "application/json";
 145
 146   // security headers
 147   resp->headers["X-Content-Type-Options"] = "nosniff";
 148   resp->headers["X-Frame-Options"] = "deny";
 149   resp->headers["X-Permitted-Cross-Domain-Policies"] = "none";
 150   resp->headers["X-XSS-Protection"] = "1; mode=block";
 151   resp->headers["Content-Security-Policy"] = "default-src 'self'; style-src 'self' 'unsafe-inline'";
 152
 153   req->getvars.erase("_"); // jQuery cache buster
 154
 155   try {
 156     resp->status = 200;
 157     handler(req, resp);
 158   } catch (ApiException &e) {
 159     resp->setErrorResult(e.what(), 422);
 160     return;
 161   } catch (JsonException &e) {
 162     resp->setErrorResult(e.what(), 422);
 163     return;
 164   }
 165
 166   if (resp->status == 204) {
 167     // No Content -> no Content-Type.
 168     resp->headers.erase("Content-Type");
 169   }
 170 }
 171
 172 void WebServer::registerApiHandler(const string& url, HandlerFunction handler) {
 173   HandlerFunction f = boost::bind(&apiWrapper, handler, _1, _2, d_apikey);
 174   registerBareHandler(url, f);
 175   d_registerApiHandlerCalled = true;
 176 }
 177
 178 static void webWrapper(WebServer::HandlerFunction handler, HttpRequest* req, HttpResponse* resp, const string &password) {
 179   if (!password.empty()) {
 180     bool auth_ok = req->compareAuthorization(password);
 181     if (!auth_ok) {
 182       g_log<<Logger::Debug<<req->logprefix<<"HTTP Request \"" << req->url.path << "\": Web Authentication failed" << endl;
 183       throw HttpUnauthorizedException("Basic");
 184     }
 185   }
 186
 187   handler(req, resp);
 188 }
 189
 190 void WebServer::registerWebHandler(const string& url, HandlerFunction handler) {
 191   HandlerFunction f = boost::bind(&webWrapper, handler, _1, _2, d_webserverPassword);
 192   registerBareHandler(url, f);
 193 }
 194
 195 static void *WebServerConnectionThreadStart(const WebServer* webServer, std::shared_ptr<Socket> client) {
 196   setThreadName("pdns-r/webhndlr");
 197   webServer->serveConnection(client);
 198   return nullptr;
 199 }
 200
 201 void WebServer::handleRequest(HttpRequest& req, HttpResponse& resp) const
 202 {
 203   // set default headers
 204   resp.headers["Content-Type"] = "text/html; charset=utf-8";
 205
 206   try {
 207     if (!req.complete) {
 208       g_log<<Logger::Debug<<req.logprefix<<"Incomplete request" << endl;
 209       throw HttpBadRequestException();
 210     }
 211
 212     g_log<<Logger::Debug<<req.logprefix<<"Handling request \"" << req.url.path << "\"" << endl;
 213
 214     YaHTTP::strstr_map_t::iterator header;
 215
 216     if ((header = req.headers.find("accept")) != req.headers.end()) {
 217       // json wins over html
 218       if (header->second.find("application/json") != std::string::npos) {
 219         req.accept_json = true;
 220       } else if (header->second.find("text/html") != std::string::npos) {
 221         req.accept_html = true;
 222       }
 223     }
 224
 225     YaHTTP::THandlerFunction handler;
 226     if (!YaHTTP::Router::Route(&req, handler)) {
 227       g_log<<Logger::Debug<<req.logprefix<<"No route found for \"" << req.url.path << "\"" << endl;
 228       throw HttpNotFoundException();
 229     }
 230
 231     try {
 232       handler(&req, &resp);
 233       g_log<<Logger::Debug<<req.logprefix<<"Result for \"" << req.url.path << "\": " << resp.status << ", body length: " << resp.body.size() << endl;
 234     }
 235     catch(HttpException&) {
 236       throw;
 237     }
 238     catch(PDNSException &e) {
 239       g_log<<Logger::Error<<req.logprefix<<"HTTP ISE for \""<< req.url.path << "\": Exception: " << e.reason << endl;
 240       throw HttpInternalServerErrorException();
 241     }
 242     catch(std::exception &e) {
 243       g_log<<Logger::Error<<req.logprefix<<"HTTP ISE for \""<< req.url.path << "\": STL Exception: " << e.what() << endl;
 244       throw HttpInternalServerErrorException();
 245     }
 246     catch(...) {
 247       g_log<<Logger::Error<<req.logprefix<<"HTTP ISE for \""<< req.url.path << "\": Unknown Exception" << endl;
 248       throw HttpInternalServerErrorException();
 249     }
 250   }
 251   catch(HttpException &e) {
 252     resp = e.response();
 253     // TODO rm this logline?
 254     g_log<<Logger::Debug<<req.logprefix<<"Error result for \"" << req.url.path << "\": " << resp.status << endl;
 255     string what = YaHTTP::Utility::status2text(resp.status);
 256     if(req.accept_html) {
 257       resp.headers["Content-Type"] = "text/html; charset=utf-8";
 258       resp.body = "<!html><title>" + what + "</title><h1>" + what + "</h1>";
 259     } else if (req.accept_json) {
 260       resp.headers["Content-Type"] = "application/json";
 261       if (resp.body.empty()) {
 262         resp.setErrorResult(what, resp.status);
 263       }
 264     } else {
 265       resp.headers["Content-Type"] = "text/plain; charset=utf-8";
 266       resp.body = what;
 267     }
 268   }
 269
 270   // always set these headers
 271   resp.headers["Server"] = "PowerDNS/" VERSION;
 272   resp.headers["Connection"] = "close";
 273
 274   if (req.method == "HEAD") {
 275     resp.body = "";
 276   } else {
 277     resp.headers["Content-Length"] = std::to_string(resp.body.size());
 278   }
 279 }
 280
 281 void WebServer::serveConnection(std::shared_ptr<Socket> client) const {
 282   const string logprefix = d_logprefix + "<" + to_string(getUniqueID()) + "> ";
 283
 284   HttpRequest req(logprefix);
 285   HttpResponse resp;
 286   ComboAddress remote;
 287   string reply;
 288
 289   try {
 290     YaHTTP::AsyncRequestLoader yarl;
 291     yarl.initialize(&req);
 292     int timeout = 5;
 293     client->setNonBlocking();
 294
 295     try {
 296       while(!req.complete) {
 297         int bytes;
 298         char buf[1024];
 299         bytes = client->readWithTimeout(buf, sizeof(buf), timeout);
 300         if (bytes > 0) {
 301           string data = string(buf, bytes);
 302           req.complete = yarl.feed(data);
 303         } else {
 304           // read error OR EOF
 305           break;
 306         }
 307       }
 308       yarl.finalize();
 309     } catch (YaHTTP::ParseError &e) {
 310       // request stays incomplete
 311     }
 312
 313     if (d_loglevel >= WebServer::LogLevel::None) {
 314       client->getRemote(remote);
 315     }
 316
 317     if (d_loglevel >= WebServer::LogLevel::Detailed) {
 318       g_log<<Logger::Info<<logprefix<<"Request Details:"<<endl;
 319
 320       bool first = true;
 321       for (const auto& r : req.getvars) {
 322         if (first) {
 323           first = false;
 324           g_log<<Logger::Info<<logprefix<<" GET params:"<<endl;
 325         }
 326         g_log<<Logger::Info<<logprefix<<"  "<<r.first<<": "<<r.second<<endl;
 327       }
 328
 329       first = true;
 330       for (const auto& r : req.postvars) {
 331         if (first) {
 332           first = false;
 333           g_log<<Logger::Info<<logprefix<<" POST params:"<<endl;
 334         }
 335         g_log<<Logger::Info<<logprefix<<"  "<<r.first<<": "<<r.second<<endl;
 336       }
 337       first = true;
 338
 339       for (const auto& h : req.headers) {
 340         if (first) {
 341           first = false;
 342           g_log<<Logger::Info<<logprefix<<" Headers:"<<endl;
 343         }
 344         g_log<<Logger::Info<<logprefix<<"  "<<h.first<<": "<<h.second<<endl;
 345       }
 346
 347       if (req.body.empty()) {
 348         g_log<<Logger::Info<<logprefix<<" No body"<<endl;
 349       } else {
 350         g_log<<Logger::Info<<logprefix<<" Full body: "<<endl;
 351         g_log<<Logger::Info<<logprefix<<"  "<<req.body<<endl;
 352       }
 353     }
 354
 355     WebServer::handleRequest(req, resp);
 356     ostringstream ss;
 357     resp.write(ss);
 358     reply = ss.str();
 359
 360     if (d_loglevel >= WebServer::LogLevel::Detailed) {
 361       g_log<<Logger::Info<<logprefix<<"Response details:"<<endl;
 362       bool first = true;
 363       for (const auto& h : resp.headers) {
 364         if (first) {
 365           first = false;
 366           g_log<<Logger::Info<<logprefix<<" Headers:"<<endl;
 367         }
 368         g_log<<Logger::Info<<logprefix<<"  "<<h.first<<": "<<h.second<<endl;
 369       }
 370       if (resp.body.empty()) {
 371         g_log<<Logger::Info<<logprefix<<" No body"<<endl;
 372       } else {
 373         g_log<<Logger::Info<<logprefix<<" Full body: "<<endl;
 374         g_log<<Logger::Info<<logprefix<<"  "<<resp.body<<endl;
 375       }
 376     }
 377
 378     client->writenWithTimeout(reply.c_str(), reply.size(), timeout);
 379   }
 380   catch(PDNSException &e) {
 381     g_log<<Logger::Error<<logprefix<<"HTTP Exception: "<<e.reason<<endl;
 382   }
 383   catch(std::exception &e) {
 384     if(strstr(e.what(), "timeout")==0)
 385       g_log<<Logger::Error<<logprefix<<"HTTP STL Exception: "<<e.what()<<endl;
 386   }
 387   catch(...) {
 388     g_log<<Logger::Error<<logprefix<<"Unknown exception"<<endl;
 389   }
 390
 391   if (d_loglevel >= WebServer::LogLevel::Normal) {
 392     g_log<<Logger::Info<<logprefix<<remote<<" \""<<req.method<<" "<<req.url.path<<" HTTP/"<<req.versionStr(req.version)<<"\" "<<resp.status<<" "<<reply.size()<<endl;
 393   }
 394 }
 395
 396 WebServer::WebServer(const string &listenaddress, int port) :
 397   d_listenaddress(listenaddress),
 398   d_port(port),
 399   d_server(nullptr)
 400 {
 401 }
 402
 403 void WebServer::bind()
 404 {
 405   try {
 406     d_server = createServer();
 407     g_log<<Logger::Warning<<d_logprefix<<"Listening for HTTP requests on "<<d_server->d_local.toStringWithPort()<<endl;
 408   }
 409   catch(NetworkError &e) {
 410     g_log<<Logger::Error<<d_logprefix<<"Listening on HTTP socket failed: "<<e.what()<<endl;
 411     d_server = nullptr;
 412   }
 413 }
 414
 415 void WebServer::go()
 416 {
 417   if(!d_server)
 418     return;
 419   try {
 420     while(true) {
 421       try {
 422         auto client = d_server->accept();
 423         if (!client) {
 424           continue;
 425         }
 426         if (client->acl(d_acl)) {
 427           std::thread webHandler(WebServerConnectionThreadStart, this, client);
 428           webHandler.detach();
 429         } else {
 430           ComboAddress remote;
 431           if (client->getRemote(remote))
 432             g_log<<Logger::Error<<d_logprefix<<"Webserver closing socket: remote ("<< remote.toString() <<") does not match the set ACL("<<d_acl.toString()<<")"<<endl;
 433         }
 434       }
 435       catch(PDNSException &e) {
 436         g_log<<Logger::Error<<d_logprefix<<"PDNSException while accepting a connection in main webserver thread: "<<e.reason<<endl;
 437       }
 438       catch(std::exception &e) {
 439         g_log<<Logger::Error<<d_logprefix<<"STL Exception while accepting a connection in main webserver thread: "<<e.what()<<endl;
 440       }
 441       catch(...) {
 442         g_log<<Logger::Error<<d_logprefix<<"Unknown exception while accepting a connection in main webserver thread"<<endl;
 443       }
 444     }
 445   }
 446   catch(PDNSException &e) {
 447     g_log<<Logger::Error<<d_logprefix<<"PDNSException in main webserver thread: "<<e.reason<<endl;
 448   }
 449   catch(std::exception &e) {
 450     g_log<<Logger::Error<<d_logprefix<<"STL Exception in main webserver thread: "<<e.what()<<endl;
 451   }
 452   catch(...) {
 453     g_log<<Logger::Error<<d_logprefix<<"Unknown exception in main webserver thread"<<endl;
 454   }
 455   _exit(1);
 456 }