src/modules/extra/m_mysql.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
   5  *   Copyright (C) 2006-2007, 2009 Dennis Friis <peavey@inspircd.org>
   6  *   Copyright (C) 2006-2009 Craig Edwards <craigedwards@brainbox.cc>
   7  *   Copyright (C) 2008 Robin Burchell <robin+git@viroteck.net>
   8  *
   9  * This file is part of InspIRCd.  InspIRCd is free software: you can
  10  * redistribute it and/or modify it under the terms of the GNU General Public
  11  * License as published by the Free Software Foundation, version 2.
  12  *
  13  * This program is distributed in the hope that it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  15  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22
  23 /* Stop mysql wanting to use long long */
  24 #define NO_CLIENT_LONG_LONG
  25
  26 #include "inspircd.h"
  27 #include <mysql.h>
  28 #include "modules/sql.h"
  29
  30 #ifdef _WIN32
  31 # pragma comment(lib, "mysqlclient.lib")
  32 # pragma comment(lib, "advapi32.lib")
  33 # pragma comment(linker, "/NODEFAULTLIB:LIBCMT")
  34 #endif
  35
  36 /* VERSION 3 API: With nonblocking (threaded) requests */
  37
  38 /* $CompileFlags: exec("mysql_config --include") */
  39 /* $LinkerFlags: exec("mysql_config --libs_r") rpath("mysql_config --libs_r") */
  40
  41 /* THE NONBLOCKING MYSQL API!
  42  *
  43  * MySQL provides no nonblocking (asyncronous) API of its own, and its developers recommend
  44  * that instead, you should thread your program. This is what i've done here to allow for
  45  * asyncronous SQL requests via mysql. The way this works is as follows:
  46  *
  47  * The module spawns a thread via class Thread, and performs its mysql queries in this thread,
  48  * using a queue with priorities. There is a mutex on either end which prevents two threads
  49  * adjusting the queue at the same time, and crashing the ircd. Every 50 milliseconds, the
  50  * worker thread wakes up, and checks if there is a request at the head of its queue.
  51  * If there is, it processes this request, blocking the worker thread but leaving the ircd
  52  * thread to go about its business as usual. During this period, the ircd thread is able
  53  * to insert futher pending requests into the queue.
  54  *
  55  * Once the processing of a request is complete, it is removed from the incoming queue to
  56  * an outgoing queue, and initialized as a 'response'. The worker thread then signals the
  57  * ircd thread (via a loopback socket) of the fact a result is available, by sending the
  58  * connection ID through the connection.
  59  *
  60  * The ircd thread then mutexes the queue once more, reads the outbound response off the head
  61  * of the queue, and sends it on its way to the original calling module.
  62  *
  63  * XXX: You might be asking "why doesnt he just send the response from within the worker thread?"
  64  * The answer to this is simple. The majority of InspIRCd, and in fact most ircd's are not
  65  * threadsafe. This module is designed to be threadsafe and is careful with its use of threads,
  66  * however, if we were to call a module's OnRequest even from within a thread which was not the
  67  * one the module was originally instantiated upon, there is a chance of all hell breaking loose
  68  * if a module is ever put in a re-enterant state (stack corruption could occur, crashes, data
  69  * corruption, and worse, so DONT think about it until the day comes when InspIRCd is 100%
  70  * gauranteed threadsafe!)
  71  *
  72  * For a diagram of this system please see http://wiki.inspircd.org/Mysql2
  73  */
  74
  75 class SQLConnection;
  76 class MySQLresult;
  77 class DispatcherThread;
  78
  79 struct QQueueItem
  80 {
  81         SQLQuery* q;
  82         std::string query;
  83         SQLConnection* c;
  84         QQueueItem(SQLQuery* Q, const std::string& S, SQLConnection* C) : q(Q), query(S), c(C) {}
  85 };
  86
  87 struct RQueueItem
  88 {
  89         SQLQuery* q;
  90         MySQLresult* r;
  91         RQueueItem(SQLQuery* Q, MySQLresult* R) : q(Q), r(R) {}
  92 };
  93
  94 typedef std::map<std::string, SQLConnection*> ConnMap;
  95 typedef std::deque<QQueueItem> QueryQueue;
  96 typedef std::deque<RQueueItem> ResultQueue;
  97
  98 /** MySQL module
  99  *  */
 100 class ModuleSQL : public Module
 101 {
 102  public:
 103         DispatcherThread* Dispatcher;
 104         QueryQueue qq;       // MUST HOLD MUTEX
 105         ResultQueue rq;      // MUST HOLD MUTEX
 106         ConnMap connections; // main thread only
 107
 108         ModuleSQL();
 109         void init() CXX11_OVERRIDE;
 110         ~ModuleSQL();
 111         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE;
 112         void OnUnloadModule(Module* mod) CXX11_OVERRIDE;
 113         Version GetVersion() CXX11_OVERRIDE;
 114 };
 115
 116 class DispatcherThread : public SocketThread
 117 {
 118  private:
 119         ModuleSQL* const Parent;
 120  public:
 121         DispatcherThread(ModuleSQL* CreatorModule) : Parent(CreatorModule) { }
 122         ~DispatcherThread() { }
 123         void Run();
 124         void OnNotify();
 125 };
 126
 127 #if !defined(MYSQL_VERSION_ID) || MYSQL_VERSION_ID<32224
 128 #define mysql_field_count mysql_num_fields
 129 #endif
 130
 131 /** Represents a mysql result set
 132  */
 133 class MySQLresult : public SQLResult
 134 {
 135  public:
 136         SQLerror err;
 137         int currentrow;
 138         int rows;
 139         std::vector<std::string> colnames;
 140         std::vector<SQLEntries> fieldlists;
 141
 142         MySQLresult(MYSQL_RES* res, int affected_rows) : err(SQL_NO_ERROR), currentrow(0), rows(0)
 143         {
 144                 if (affected_rows >= 1)
 145                 {
 146                         rows = affected_rows;
 147                         fieldlists.resize(rows);
 148                 }
 149                 unsigned int field_count = 0;
 150                 if (res)
 151                 {
 152                         MYSQL_ROW row;
 153                         int n = 0;
 154                         while ((row = mysql_fetch_row(res)))
 155                         {
 156                                 if (fieldlists.size() < (unsigned int)rows+1)
 157                                 {
 158                                         fieldlists.resize(fieldlists.size()+1);
 159                                 }
 160                                 field_count = 0;
 161                                 MYSQL_FIELD *fields = mysql_fetch_fields(res);
 162                                 if(mysql_num_fields(res) == 0)
 163                                         break;
 164                                 if (fields && mysql_num_fields(res))
 165                                 {
 166                                         colnames.clear();
 167                                         while (field_count < mysql_num_fields(res))
 168                                         {
 169                                                 std::string a = (fields[field_count].name ? fields[field_count].name : "");
 170                                                 if (row[field_count])
 171                                                         fieldlists[n].push_back(SQLEntry(row[field_count]));
 172                                                 else
 173                                                         fieldlists[n].push_back(SQLEntry());
 174                                                 colnames.push_back(a);
 175                                                 field_count++;
 176                                         }
 177                                         n++;
 178                                 }
 179                                 rows++;
 180                         }
 181                         mysql_free_result(res);
 182                 }
 183         }
 184
 185         MySQLresult(SQLerror& e) : err(e)
 186         {
 187
 188         }
 189
 190         int Rows()
 191         {
 192                 return rows;
 193         }
 194
 195         void GetCols(std::vector<std::string>& result)
 196         {
 197                 result.assign(colnames.begin(), colnames.end());
 198         }
 199
 200         SQLEntry GetValue(int row, int column)
 201         {
 202                 if ((row >= 0) && (row < rows) && (column >= 0) && (column < (int)fieldlists[row].size()))
 203                 {
 204                         return fieldlists[row][column];
 205                 }
 206                 return SQLEntry();
 207         }
 208
 209         bool GetRow(SQLEntries& result)
 210         {
 211                 if (currentrow < rows)
 212                 {
 213                         result.assign(fieldlists[currentrow].begin(), fieldlists[currentrow].end());
 214                         currentrow++;
 215                         return true;
 216                 }
 217                 else
 218                 {
 219                         result.clear();
 220                         return false;
 221                 }
 222         }
 223 };
 224
 225 /** Represents a connection to a mysql database
 226  */
 227 class SQLConnection : public SQLProvider
 228 {
 229  public:
 230         reference<ConfigTag> config;
 231         MYSQL *connection;
 232         Mutex lock;
 233
 234         // This constructor creates an SQLConnection object with the given credentials, but does not connect yet.
 235         SQLConnection(Module* p, ConfigTag* tag) : SQLProvider(p, "SQL/" + tag->getString("id")),
 236                 config(tag), connection(NULL)
 237         {
 238         }
 239
 240         ~SQLConnection()
 241         {
 242                 Close();
 243         }
 244
 245         // This method connects to the database using the credentials supplied to the constructor, and returns
 246         // true upon success.
 247         bool Connect()
 248         {
 249                 unsigned int timeout = 1;
 250                 connection = mysql_init(connection);
 251                 mysql_options(connection,MYSQL_OPT_CONNECT_TIMEOUT,(char*)&timeout);
 252                 std::string host = config->getString("host");
 253                 std::string user = config->getString("user");
 254                 std::string pass = config->getString("pass");
 255                 std::string dbname = config->getString("name");
 256                 int port = config->getInt("port");
 257                 bool rv = mysql_real_connect(connection, host.c_str(), user.c_str(), pass.c_str(), dbname.c_str(), port, NULL, 0);
 258                 if (!rv)
 259                         return rv;
 260                 std::string initquery;
 261                 if (config->readString("initialquery", initquery))
 262                 {
 263                         mysql_query(connection,initquery.c_str());
 264                 }
 265                 return true;
 266         }
 267
 268         ModuleSQL* Parent()
 269         {
 270                 return (ModuleSQL*)(Module*)creator;
 271         }
 272
 273         MySQLresult* DoBlockingQuery(const std::string& query)
 274         {
 275
 276                 /* Parse the command string and dispatch it to mysql */
 277                 if (CheckConnection() && !mysql_real_query(connection, query.data(), query.length()))
 278                 {
 279                         /* Successfull query */
 280                         MYSQL_RES* res = mysql_use_result(connection);
 281                         unsigned long rows = mysql_affected_rows(connection);
 282                         return new MySQLresult(res, rows);
 283                 }
 284                 else
 285                 {
 286                         /* XXX: See /usr/include/mysql/mysqld_error.h for a list of
 287                          * possible error numbers and error messages */
 288                         SQLerror e(SQL_QREPLY_FAIL, ConvToStr(mysql_errno(connection)) + ": " + mysql_error(connection));
 289                         return new MySQLresult(e);
 290                 }
 291         }
 292
 293         bool CheckConnection()
 294         {
 295                 if (!connection || mysql_ping(connection) != 0)
 296                         return Connect();
 297                 return true;
 298         }
 299
 300         std::string GetError()
 301         {
 302                 return mysql_error(connection);
 303         }
 304
 305         void Close()
 306         {
 307                 mysql_close(connection);
 308         }
 309
 310         void submit(SQLQuery* q, const std::string& qs)
 311         {
 312                 Parent()->Dispatcher->LockQueue();
 313                 Parent()->qq.push_back(QQueueItem(q, qs, this));
 314                 Parent()->Dispatcher->UnlockQueueWakeup();
 315         }
 316
 317         void submit(SQLQuery* call, const std::string& q, const ParamL& p)
 318         {
 319                 std::string res;
 320                 unsigned int param = 0;
 321                 for(std::string::size_type i = 0; i < q.length(); i++)
 322                 {
 323                         if (q[i] != '?')
 324                                 res.push_back(q[i]);
 325                         else
 326                         {
 327                                 if (param < p.size())
 328                                 {
 329                                         std::string parm = p[param++];
 330                                         // In the worst case, each character may need to be encoded as using two bytes,
 331                                         // and one byte is the terminating null
 332                                         std::vector<char> buffer(parm.length() * 2 + 1);
 333
 334                                         // The return value of mysql_escape_string() is the length of the encoded string,
 335                                         // not including the terminating null
 336                                         unsigned long escapedsize = mysql_escape_string(&buffer[0], parm.c_str(), parm.length());
 337 //                                      mysql_real_escape_string(connection, queryend, paramscopy[paramnum].c_str(), paramscopy[paramnum].length());
 338                                         res.append(&buffer[0], escapedsize);
 339                                 }
 340                         }
 341                 }
 342                 submit(call, res);
 343         }
 344
 345         void submit(SQLQuery* call, const std::string& q, const ParamM& p)
 346         {
 347                 std::string res;
 348                 for(std::string::size_type i = 0; i < q.length(); i++)
 349                 {
 350                         if (q[i] != '$')
 351                                 res.push_back(q[i]);
 352                         else
 353                         {
 354                                 std::string field;
 355                                 i++;
 356                                 while (i < q.length() && isalnum(q[i]))
 357                                         field.push_back(q[i++]);
 358                                 i--;
 359
 360                                 ParamM::const_iterator it = p.find(field);
 361                                 if (it != p.end())
 362                                 {
 363                                         std::string parm = it->second;
 364                                         // NOTE: See above
 365                                         std::vector<char> buffer(parm.length() * 2 + 1);
 366                                         unsigned long escapedsize = mysql_escape_string(&buffer[0], parm.c_str(), parm.length());
 367                                         res.append(&buffer[0], escapedsize);
 368                                 }
 369                         }
 370                 }
 371                 submit(call, res);
 372         }
 373 };
 374
 375 ModuleSQL::ModuleSQL()
 376 {
 377         Dispatcher = NULL;
 378 }
 379
 380 void ModuleSQL::init()
 381 {
 382         Dispatcher = new DispatcherThread(this);
 383         ServerInstance->Threads.Start(Dispatcher);
 384 }
 385
 386 ModuleSQL::~ModuleSQL()
 387 {
 388         if (Dispatcher)
 389         {
 390                 Dispatcher->join();
 391                 Dispatcher->OnNotify();
 392                 delete Dispatcher;
 393         }
 394         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 395         {
 396                 delete i->second;
 397         }
 398 }
 399
 400 void ModuleSQL::ReadConfig(ConfigStatus& status)
 401 {
 402         ConnMap conns;
 403         ConfigTagList tags = ServerInstance->Config->ConfTags("database");
 404         for(ConfigIter i = tags.first; i != tags.second; i++)
 405         {
 406                 if (i->second->getString("module", "mysql") != "mysql")
 407                         continue;
 408                 std::string id = i->second->getString("id");
 409                 ConnMap::iterator curr = connections.find(id);
 410                 if (curr == connections.end())
 411                 {
 412                         SQLConnection* conn = new SQLConnection(this, i->second);
 413                         conns.insert(std::make_pair(id, conn));
 414                         ServerInstance->Modules->AddService(*conn);
 415                 }
 416                 else
 417                 {
 418                         conns.insert(*curr);
 419                         connections.erase(curr);
 420                 }
 421         }
 422
 423         // now clean up the deleted databases
 424         Dispatcher->LockQueue();
 425         SQLerror err(SQL_BAD_DBID);
 426         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 427         {
 428                 ServerInstance->Modules->DelService(*i->second);
 429                 // it might be running a query on this database. Wait for that to complete
 430                 i->second->lock.Lock();
 431                 i->second->lock.Unlock();
 432                 // now remove all active queries to this DB
 433                 for (size_t j = qq.size(); j > 0; j--)
 434                 {
 435                         size_t k = j - 1;
 436                         if (qq[k].c == i->second)
 437                         {
 438                                 qq[k].q->OnError(err);
 439                                 delete qq[k].q;
 440                                 qq.erase(qq.begin() + k);
 441                         }
 442                 }
 443                 // finally, nuke the connection
 444                 delete i->second;
 445         }
 446         Dispatcher->UnlockQueue();
 447         connections.swap(conns);
 448 }
 449
 450 void ModuleSQL::OnUnloadModule(Module* mod)
 451 {
 452         SQLerror err(SQL_BAD_DBID);
 453         Dispatcher->LockQueue();
 454         unsigned int i = qq.size();
 455         while (i > 0)
 456         {
 457                 i--;
 458                 if (qq[i].q->creator == mod)
 459                 {
 460                         if (i == 0)
 461                         {
 462                                 // need to wait until the query is done
 463                                 // (the result will be discarded)
 464                                 qq[i].c->lock.Lock();
 465                                 qq[i].c->lock.Unlock();
 466                         }
 467                         qq[i].q->OnError(err);
 468                         delete qq[i].q;
 469                         qq.erase(qq.begin() + i);
 470                 }
 471         }
 472         Dispatcher->UnlockQueue();
 473         // clean up any result queue entries
 474         Dispatcher->OnNotify();
 475 }
 476
 477 Version ModuleSQL::GetVersion()
 478 {
 479         return Version("MySQL support", VF_VENDOR);
 480 }
 481
 482 void DispatcherThread::Run()
 483 {
 484         this->LockQueue();
 485         while (!this->GetExitFlag())
 486         {
 487                 if (!Parent->qq.empty())
 488                 {
 489                         QQueueItem i = Parent->qq.front();
 490                         i.c->lock.Lock();
 491                         this->UnlockQueue();
 492                         MySQLresult* res = i.c->DoBlockingQuery(i.query);
 493                         i.c->lock.Unlock();
 494
 495                         /*
 496                          * At this point, the main thread could be working on:
 497                          *  Rehash - delete i.c out from under us. We don't care about that.
 498                          *  UnloadModule - delete i.q and the qq item. Need to avoid reporting results.
 499                          */
 500
 501                         this->LockQueue();
 502                         if (!Parent->qq.empty() && Parent->qq.front().q == i.q)
 503                         {
 504                                 Parent->qq.pop_front();
 505                                 Parent->rq.push_back(RQueueItem(i.q, res));
 506                                 NotifyParent();
 507                         }
 508                         else
 509                         {
 510                                 // UnloadModule ate the query
 511                                 delete res;
 512                         }
 513                 }
 514                 else
 515                 {
 516                         /* We know the queue is empty, we can safely hang this thread until
 517                          * something happens
 518                          */
 519                         this->WaitForQueue();
 520                 }
 521         }
 522         this->UnlockQueue();
 523 }
 524
 525 void DispatcherThread::OnNotify()
 526 {
 527         // this could unlock during the dispatch, but OnResult isn't expected to take that long
 528         this->LockQueue();
 529         for(ResultQueue::iterator i = Parent->rq.begin(); i != Parent->rq.end(); i++)
 530         {
 531                 MySQLresult* res = i->r;
 532                 if (res->err.id == SQL_NO_ERROR)
 533                         i->q->OnResult(*res);
 534                 else
 535                         i->q->OnError(res->err);
 536                 delete i->q;
 537                 delete i->r;
 538         }
 539         Parent->rq.clear();
 540         this->UnlockQueue();
 541 }
 542
 543 MODULE_INIT(ModuleSQL)