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 // Fix warnings about the use of `long long` on C++03.
  24 #if defined __clang__
  25 # pragma clang diagnostic ignored "-Wc++11-long-long"
  26 #elif defined __GNUC__
  27 # pragma GCC diagnostic ignored "-Wlong-long"
  28 #endif
  29
  30 #include "inspircd.h"
  31 #include <mysql.h>
  32 #include "modules/sql.h"
  33
  34 #ifdef _WIN32
  35 # pragma comment(lib, "libmysql.lib")
  36 #endif
  37
  38 /* VERSION 3 API: With nonblocking (threaded) requests */
  39
  40 /* $CompileFlags: exec("mysql_config --include") */
  41 /* $LinkerFlags: exec("mysql_config --libs_r") rpath("mysql_config --libs_r") */
  42
  43 /* THE NONBLOCKING MYSQL API!
  44  *
  45  * MySQL provides no nonblocking (asyncronous) API of its own, and its developers recommend
  46  * that instead, you should thread your program. This is what i've done here to allow for
  47  * asyncronous SQL requests via mysql. The way this works is as follows:
  48  *
  49  * The module spawns a thread via class Thread, and performs its mysql queries in this thread,
  50  * using a queue with priorities. There is a mutex on either end which prevents two threads
  51  * adjusting the queue at the same time, and crashing the ircd. Every 50 milliseconds, the
  52  * worker thread wakes up, and checks if there is a request at the head of its queue.
  53  * If there is, it processes this request, blocking the worker thread but leaving the ircd
  54  * thread to go about its business as usual. During this period, the ircd thread is able
  55  * to insert futher pending requests into the queue.
  56  *
  57  * Once the processing of a request is complete, it is removed from the incoming queue to
  58  * an outgoing queue, and initialized as a 'response'. The worker thread then signals the
  59  * ircd thread (via a loopback socket) of the fact a result is available, by sending the
  60  * connection ID through the connection.
  61  *
  62  * The ircd thread then mutexes the queue once more, reads the outbound response off the head
  63  * of the queue, and sends it on its way to the original calling module.
  64  *
  65  * XXX: You might be asking "why doesnt he just send the response from within the worker thread?"
  66  * The answer to this is simple. The majority of InspIRCd, and in fact most ircd's are not
  67  * threadsafe. This module is designed to be threadsafe and is careful with its use of threads,
  68  * however, if we were to call a module's OnRequest even from within a thread which was not the
  69  * one the module was originally instantiated upon, there is a chance of all hell breaking loose
  70  * if a module is ever put in a re-enterant state (stack corruption could occur, crashes, data
  71  * corruption, and worse, so DONT think about it until the day comes when InspIRCd is 100%
  72  * gauranteed threadsafe!)
  73  *
  74  * For a diagram of this system please see http://wiki.inspircd.org/Mysql2
  75  */
  76
  77 class SQLConnection;
  78 class MySQLresult;
  79 class DispatcherThread;
  80
  81 struct QQueueItem
  82 {
  83         SQLQuery* q;
  84         std::string query;
  85         SQLConnection* c;
  86         QQueueItem(SQLQuery* Q, const std::string& S, SQLConnection* C) : q(Q), query(S), c(C) {}
  87 };
  88
  89 struct RQueueItem
  90 {
  91         SQLQuery* q;
  92         MySQLresult* r;
  93         RQueueItem(SQLQuery* Q, MySQLresult* R) : q(Q), r(R) {}
  94 };
  95
  96 typedef insp::flat_map<std::string, SQLConnection*> ConnMap;
  97 typedef std::deque<QQueueItem> QueryQueue;
  98 typedef std::deque<RQueueItem> ResultQueue;
  99
 100 /** MySQL module
 101  *  */
 102 class ModuleSQL : public Module
 103 {
 104  public:
 105         DispatcherThread* Dispatcher;
 106         QueryQueue qq;       // MUST HOLD MUTEX
 107         ResultQueue rq;      // MUST HOLD MUTEX
 108         ConnMap connections; // main thread only
 109
 110         ModuleSQL();
 111         void init() CXX11_OVERRIDE;
 112         ~ModuleSQL();
 113         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE;
 114         void OnUnloadModule(Module* mod) CXX11_OVERRIDE;
 115         Version GetVersion() CXX11_OVERRIDE;
 116 };
 117
 118 class DispatcherThread : public SocketThread
 119 {
 120  private:
 121         ModuleSQL* const Parent;
 122  public:
 123         DispatcherThread(ModuleSQL* CreatorModule) : Parent(CreatorModule) { }
 124         ~DispatcherThread() { }
 125         void Run();
 126         void OnNotify();
 127 };
 128
 129 #if !defined(MYSQL_VERSION_ID) || MYSQL_VERSION_ID<32224
 130 #define mysql_field_count mysql_num_fields
 131 #endif
 132
 133 /** Represents a mysql result set
 134  */
 135 class MySQLresult : public SQLResult
 136 {
 137  public:
 138         SQLerror err;
 139         int currentrow;
 140         int rows;
 141         std::vector<std::string> colnames;
 142         std::vector<SQLEntries> fieldlists;
 143
 144         MySQLresult(MYSQL_RES* res, int affected_rows) : err(SQL_NO_ERROR), currentrow(0), rows(0)
 145         {
 146                 if (affected_rows >= 1)
 147                 {
 148                         rows = affected_rows;
 149                         fieldlists.resize(rows);
 150                 }
 151                 unsigned int field_count = 0;
 152                 if (res)
 153                 {
 154                         MYSQL_ROW row;
 155                         int n = 0;
 156                         while ((row = mysql_fetch_row(res)))
 157                         {
 158                                 if (fieldlists.size() < (unsigned int)rows+1)
 159                                 {
 160                                         fieldlists.resize(fieldlists.size()+1);
 161                                 }
 162                                 field_count = 0;
 163                                 MYSQL_FIELD *fields = mysql_fetch_fields(res);
 164                                 if(mysql_num_fields(res) == 0)
 165                                         break;
 166                                 if (fields && mysql_num_fields(res))
 167                                 {
 168                                         colnames.clear();
 169                                         while (field_count < mysql_num_fields(res))
 170                                         {
 171                                                 std::string a = (fields[field_count].name ? fields[field_count].name : "");
 172                                                 if (row[field_count])
 173                                                         fieldlists[n].push_back(SQLEntry(row[field_count]));
 174                                                 else
 175                                                         fieldlists[n].push_back(SQLEntry());
 176                                                 colnames.push_back(a);
 177                                                 field_count++;
 178                                         }
 179                                         n++;
 180                                 }
 181                                 rows++;
 182                         }
 183                         mysql_free_result(res);
 184                 }
 185         }
 186
 187         MySQLresult(SQLerror& e) : err(e)
 188         {
 189
 190         }
 191
 192         int Rows()
 193         {
 194                 return rows;
 195         }
 196
 197         void GetCols(std::vector<std::string>& result)
 198         {
 199                 result.assign(colnames.begin(), colnames.end());
 200         }
 201
 202         SQLEntry GetValue(int row, int column)
 203         {
 204                 if ((row >= 0) && (row < rows) && (column >= 0) && (column < (int)fieldlists[row].size()))
 205                 {
 206                         return fieldlists[row][column];
 207                 }
 208                 return SQLEntry();
 209         }
 210
 211         bool GetRow(SQLEntries& result)
 212         {
 213                 if (currentrow < rows)
 214                 {
 215                         result.assign(fieldlists[currentrow].begin(), fieldlists[currentrow].end());
 216                         currentrow++;
 217                         return true;
 218                 }
 219                 else
 220                 {
 221                         result.clear();
 222                         return false;
 223                 }
 224         }
 225 };
 226
 227 /** Represents a connection to a mysql database
 228  */
 229 class SQLConnection : public SQLProvider
 230 {
 231  public:
 232         reference<ConfigTag> config;
 233         MYSQL *connection;
 234         Mutex lock;
 235
 236         // This constructor creates an SQLConnection object with the given credentials, but does not connect yet.
 237         SQLConnection(Module* p, ConfigTag* tag) : SQLProvider(p, "SQL/" + tag->getString("id")),
 238                 config(tag), connection(NULL)
 239         {
 240         }
 241
 242         ~SQLConnection()
 243         {
 244                 Close();
 245         }
 246
 247         // This method connects to the database using the credentials supplied to the constructor, and returns
 248         // true upon success.
 249         bool Connect()
 250         {
 251                 unsigned int timeout = 1;
 252                 connection = mysql_init(connection);
 253                 mysql_options(connection,MYSQL_OPT_CONNECT_TIMEOUT,(char*)&timeout);
 254                 std::string host = config->getString("host");
 255                 std::string user = config->getString("user");
 256                 std::string pass = config->getString("pass");
 257                 std::string dbname = config->getString("name");
 258                 int port = config->getInt("port");
 259                 bool rv = mysql_real_connect(connection, host.c_str(), user.c_str(), pass.c_str(), dbname.c_str(), port, NULL, 0);
 260                 if (!rv)
 261                         return rv;
 262
 263                 // Enable character set settings
 264                 std::string charset = config->getString("charset");
 265                 if ((!charset.empty()) && (mysql_set_character_set(connection, charset.c_str())))
 266                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "WARNING: Could not set character set to \"%s\"", charset.c_str());
 267
 268                 std::string initquery;
 269                 if (config->readString("initialquery", initquery))
 270                 {
 271                         mysql_query(connection,initquery.c_str());
 272                 }
 273                 return true;
 274         }
 275
 276         ModuleSQL* Parent()
 277         {
 278                 return (ModuleSQL*)(Module*)creator;
 279         }
 280
 281         MySQLresult* DoBlockingQuery(const std::string& query)
 282         {
 283
 284                 /* Parse the command string and dispatch it to mysql */
 285                 if (CheckConnection() && !mysql_real_query(connection, query.data(), query.length()))
 286                 {
 287                         /* Successfull query */
 288                         MYSQL_RES* res = mysql_use_result(connection);
 289                         unsigned long rows = mysql_affected_rows(connection);
 290                         return new MySQLresult(res, rows);
 291                 }
 292                 else
 293                 {
 294                         /* XXX: See /usr/include/mysql/mysqld_error.h for a list of
 295                          * possible error numbers and error messages */
 296                         SQLerror e(SQL_QREPLY_FAIL, ConvToStr(mysql_errno(connection)) + ": " + mysql_error(connection));
 297                         return new MySQLresult(e);
 298                 }
 299         }
 300
 301         bool CheckConnection()
 302         {
 303                 if (!connection || mysql_ping(connection) != 0)
 304                         return Connect();
 305                 return true;
 306         }
 307
 308         std::string GetError()
 309         {
 310                 return mysql_error(connection);
 311         }
 312
 313         void Close()
 314         {
 315                 mysql_close(connection);
 316         }
 317
 318         void submit(SQLQuery* q, const std::string& qs)
 319         {
 320                 Parent()->Dispatcher->LockQueue();
 321                 Parent()->qq.push_back(QQueueItem(q, qs, this));
 322                 Parent()->Dispatcher->UnlockQueueWakeup();
 323         }
 324
 325         void submit(SQLQuery* call, const std::string& q, const ParamL& p)
 326         {
 327                 std::string res;
 328                 unsigned int param = 0;
 329                 for(std::string::size_type i = 0; i < q.length(); i++)
 330                 {
 331                         if (q[i] != '?')
 332                                 res.push_back(q[i]);
 333                         else
 334                         {
 335                                 if (param < p.size())
 336                                 {
 337                                         std::string parm = p[param++];
 338                                         // In the worst case, each character may need to be encoded as using two bytes,
 339                                         // and one byte is the terminating null
 340                                         std::vector<char> buffer(parm.length() * 2 + 1);
 341
 342                                         // The return value of mysql_escape_string() is the length of the encoded string,
 343                                         // not including the terminating null
 344                                         unsigned long escapedsize = mysql_escape_string(&buffer[0], parm.c_str(), parm.length());
 345 //                                      mysql_real_escape_string(connection, queryend, paramscopy[paramnum].c_str(), paramscopy[paramnum].length());
 346                                         res.append(&buffer[0], escapedsize);
 347                                 }
 348                         }
 349                 }
 350                 submit(call, res);
 351         }
 352
 353         void submit(SQLQuery* call, const std::string& q, const ParamM& p)
 354         {
 355                 std::string res;
 356                 for(std::string::size_type i = 0; i < q.length(); i++)
 357                 {
 358                         if (q[i] != '$')
 359                                 res.push_back(q[i]);
 360                         else
 361                         {
 362                                 std::string field;
 363                                 i++;
 364                                 while (i < q.length() && isalnum(q[i]))
 365                                         field.push_back(q[i++]);
 366                                 i--;
 367
 368                                 ParamM::const_iterator it = p.find(field);
 369                                 if (it != p.end())
 370                                 {
 371                                         std::string parm = it->second;
 372                                         // NOTE: See above
 373                                         std::vector<char> buffer(parm.length() * 2 + 1);
 374                                         unsigned long escapedsize = mysql_escape_string(&buffer[0], parm.c_str(), parm.length());
 375                                         res.append(&buffer[0], escapedsize);
 376                                 }
 377                         }
 378                 }
 379                 submit(call, res);
 380         }
 381 };
 382
 383 ModuleSQL::ModuleSQL()
 384 {
 385         Dispatcher = NULL;
 386 }
 387
 388 void ModuleSQL::init()
 389 {
 390         Dispatcher = new DispatcherThread(this);
 391         ServerInstance->Threads.Start(Dispatcher);
 392 }
 393
 394 ModuleSQL::~ModuleSQL()
 395 {
 396         if (Dispatcher)
 397         {
 398                 Dispatcher->join();
 399                 Dispatcher->OnNotify();
 400                 delete Dispatcher;
 401         }
 402         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 403         {
 404                 delete i->second;
 405         }
 406 }
 407
 408 void ModuleSQL::ReadConfig(ConfigStatus& status)
 409 {
 410         ConnMap conns;
 411         ConfigTagList tags = ServerInstance->Config->ConfTags("database");
 412         for(ConfigIter i = tags.first; i != tags.second; i++)
 413         {
 414                 if (i->second->getString("module", "mysql") != "mysql")
 415                         continue;
 416                 std::string id = i->second->getString("id");
 417                 ConnMap::iterator curr = connections.find(id);
 418                 if (curr == connections.end())
 419                 {
 420                         SQLConnection* conn = new SQLConnection(this, i->second);
 421                         conns.insert(std::make_pair(id, conn));
 422                         ServerInstance->Modules->AddService(*conn);
 423                 }
 424                 else
 425                 {
 426                         conns.insert(*curr);
 427                         connections.erase(curr);
 428                 }
 429         }
 430
 431         // now clean up the deleted databases
 432         Dispatcher->LockQueue();
 433         SQLerror err(SQL_BAD_DBID);
 434         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 435         {
 436                 ServerInstance->Modules->DelService(*i->second);
 437                 // it might be running a query on this database. Wait for that to complete
 438                 i->second->lock.Lock();
 439                 i->second->lock.Unlock();
 440                 // now remove all active queries to this DB
 441                 for (size_t j = qq.size(); j > 0; j--)
 442                 {
 443                         size_t k = j - 1;
 444                         if (qq[k].c == i->second)
 445                         {
 446                                 qq[k].q->OnError(err);
 447                                 delete qq[k].q;
 448                                 qq.erase(qq.begin() + k);
 449                         }
 450                 }
 451                 // finally, nuke the connection
 452                 delete i->second;
 453         }
 454         Dispatcher->UnlockQueue();
 455         connections.swap(conns);
 456 }
 457
 458 void ModuleSQL::OnUnloadModule(Module* mod)
 459 {
 460         SQLerror err(SQL_BAD_DBID);
 461         Dispatcher->LockQueue();
 462         unsigned int i = qq.size();
 463         while (i > 0)
 464         {
 465                 i--;
 466                 if (qq[i].q->creator == mod)
 467                 {
 468                         if (i == 0)
 469                         {
 470                                 // need to wait until the query is done
 471                                 // (the result will be discarded)
 472                                 qq[i].c->lock.Lock();
 473                                 qq[i].c->lock.Unlock();
 474                         }
 475                         qq[i].q->OnError(err);
 476                         delete qq[i].q;
 477                         qq.erase(qq.begin() + i);
 478                 }
 479         }
 480         Dispatcher->UnlockQueue();
 481         // clean up any result queue entries
 482         Dispatcher->OnNotify();
 483 }
 484
 485 Version ModuleSQL::GetVersion()
 486 {
 487         return Version("MySQL support", VF_VENDOR);
 488 }
 489
 490 void DispatcherThread::Run()
 491 {
 492         this->LockQueue();
 493         while (!this->GetExitFlag())
 494         {
 495                 if (!Parent->qq.empty())
 496                 {
 497                         QQueueItem i = Parent->qq.front();
 498                         i.c->lock.Lock();
 499                         this->UnlockQueue();
 500                         MySQLresult* res = i.c->DoBlockingQuery(i.query);
 501                         i.c->lock.Unlock();
 502
 503                         /*
 504                          * At this point, the main thread could be working on:
 505                          *  Rehash - delete i.c out from under us. We don't care about that.
 506                          *  UnloadModule - delete i.q and the qq item. Need to avoid reporting results.
 507                          */
 508
 509                         this->LockQueue();
 510                         if (!Parent->qq.empty() && Parent->qq.front().q == i.q)
 511                         {
 512                                 Parent->qq.pop_front();
 513                                 Parent->rq.push_back(RQueueItem(i.q, res));
 514                                 NotifyParent();
 515                         }
 516                         else
 517                         {
 518                                 // UnloadModule ate the query
 519                                 delete res;
 520                         }
 521                 }
 522                 else
 523                 {
 524                         /* We know the queue is empty, we can safely hang this thread until
 525                          * something happens
 526                          */
 527                         this->WaitForQueue();
 528                 }
 529         }
 530         this->UnlockQueue();
 531 }
 532
 533 void DispatcherThread::OnNotify()
 534 {
 535         // this could unlock during the dispatch, but OnResult isn't expected to take that long
 536         this->LockQueue();
 537         for(ResultQueue::iterator i = Parent->rq.begin(); i != Parent->rq.end(); i++)
 538         {
 539                 MySQLresult* res = i->r;
 540                 if (res->err.id == SQL_NO_ERROR)
 541                         i->q->OnResult(*res);
 542                 else
 543                         i->q->OnError(res->err);
 544                 delete i->q;
 545                 delete i->r;
 546         }
 547         Parent->rq.clear();
 548         this->UnlockQueue();
 549 }
 550
 551 MODULE_INIT(ModuleSQL)