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 "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 /* $ModDesc: SQL Service Provider module for all other m_sql* modules */
  39 /* $CompileFlags: exec("mysql_config --include") */
  40 /* $LinkerFlags: exec("mysql_config --libs_r") rpath("mysql_config --libs_r") */
  41
  42 /* THE NONBLOCKING MYSQL API!
  43  *
  44  * MySQL provides no nonblocking (asyncronous) API of its own, and its developers recommend
  45  * that instead, you should thread your program. This is what i've done here to allow for
  46  * asyncronous SQL requests via mysql. The way this works is as follows:
  47  *
  48  * The module spawns a thread via class Thread, and performs its mysql queries in this thread,
  49  * using a queue with priorities. There is a mutex on either end which prevents two threads
  50  * adjusting the queue at the same time, and crashing the ircd. Every 50 milliseconds, the
  51  * worker thread wakes up, and checks if there is a request at the head of its queue.
  52  * If there is, it processes this request, blocking the worker thread but leaving the ircd
  53  * thread to go about its business as usual. During this period, the ircd thread is able
  54  * to insert futher pending requests into the queue.
  55  *
  56  * Once the processing of a request is complete, it is removed from the incoming queue to
  57  * an outgoing queue, and initialized as a 'response'. The worker thread then signals the
  58  * ircd thread (via a loopback socket) of the fact a result is available, by sending the
  59  * connection ID through the connection.
  60  *
  61  * The ircd thread then mutexes the queue once more, reads the outbound response off the head
  62  * of the queue, and sends it on its way to the original calling module.
  63  *
  64  * XXX: You might be asking "why doesnt he just send the response from within the worker thread?"
  65  * The answer to this is simple. The majority of InspIRCd, and in fact most ircd's are not
  66  * threadsafe. This module is designed to be threadsafe and is careful with its use of threads,
  67  * however, if we were to call a module's OnRequest even from within a thread which was not the
  68  * one the module was originally instantiated upon, there is a chance of all hell breaking loose
  69  * if a module is ever put in a re-enterant state (stack corruption could occur, crashes, data
  70  * corruption, and worse, so DONT think about it until the day comes when InspIRCd is 100%
  71  * gauranteed threadsafe!)
  72  *
  73  * For a diagram of this system please see http://wiki.inspircd.org/Mysql2
  74  */
  75
  76 class SQLConnection;
  77 class MySQLresult;
  78 class DispatcherThread;
  79
  80 struct QQueueItem
  81 {
  82         SQLQuery* q;
  83         std::string query;
  84         SQLConnection* c;
  85         QQueueItem(SQLQuery* Q, const std::string& S, SQLConnection* C) : q(Q), query(S), c(C) {}
  86 };
  87
  88 struct RQueueItem
  89 {
  90         SQLQuery* q;
  91         MySQLresult* r;
  92         RQueueItem(SQLQuery* Q, MySQLresult* R) : q(Q), r(R) {}
  93 };
  94
  95 typedef std::map<std::string, SQLConnection*> ConnMap;
  96 typedef std::deque<QQueueItem> QueryQueue;
  97 typedef std::deque<RQueueItem> ResultQueue;
  98
  99 /** MySQL module
 100  *  */
 101 class ModuleSQL : public Module
 102 {
 103  public:
 104         DispatcherThread* Dispatcher;
 105         QueryQueue qq;       // MUST HOLD MUTEX
 106         ResultQueue rq;      // MUST HOLD MUTEX
 107         ConnMap connections; // main thread only
 108
 109         ModuleSQL();
 110         void init();
 111         ~ModuleSQL();
 112         void OnRehash(User* user);
 113         void OnUnloadModule(Module* mod);
 114         Version GetVersion();
 115 };
 116
 117 class DispatcherThread : public SocketThread
 118 {
 119  private:
 120         ModuleSQL* const Parent;
 121  public:
 122         DispatcherThread(ModuleSQL* CreatorModule) : Parent(CreatorModule) { }
 123         ~DispatcherThread() { }
 124         virtual void Run();
 125         virtual void OnNotify();
 126 };
 127
 128 #if !defined(MYSQL_VERSION_ID) || MYSQL_VERSION_ID<32224
 129 #define mysql_field_count mysql_num_fields
 130 #endif
 131
 132 /** Represents a mysql result set
 133  */
 134 class MySQLresult : public SQLResult
 135 {
 136  public:
 137         SQLerror err;
 138         int currentrow;
 139         int rows;
 140         std::vector<std::string> colnames;
 141         std::vector<SQLEntries> fieldlists;
 142
 143         MySQLresult(MYSQL_RES* res, int affected_rows) : err(SQL_NO_ERROR), currentrow(0), rows(0)
 144         {
 145                 if (affected_rows >= 1)
 146                 {
 147                         rows = affected_rows;
 148                         fieldlists.resize(rows);
 149                 }
 150                 unsigned int field_count = 0;
 151                 if (res)
 152                 {
 153                         MYSQL_ROW row;
 154                         int n = 0;
 155                         while ((row = mysql_fetch_row(res)))
 156                         {
 157                                 if (fieldlists.size() < (unsigned int)rows+1)
 158                                 {
 159                                         fieldlists.resize(fieldlists.size()+1);
 160                                 }
 161                                 field_count = 0;
 162                                 MYSQL_FIELD *fields = mysql_fetch_fields(res);
 163                                 if(mysql_num_fields(res) == 0)
 164                                         break;
 165                                 if (fields && mysql_num_fields(res))
 166                                 {
 167                                         colnames.clear();
 168                                         while (field_count < mysql_num_fields(res))
 169                                         {
 170                                                 std::string a = (fields[field_count].name ? fields[field_count].name : "");
 171                                                 if (row[field_count])
 172                                                         fieldlists[n].push_back(SQLEntry(row[field_count]));
 173                                                 else
 174                                                         fieldlists[n].push_back(SQLEntry());
 175                                                 colnames.push_back(a);
 176                                                 field_count++;
 177                                         }
 178                                         n++;
 179                                 }
 180                                 rows++;
 181                         }
 182                         mysql_free_result(res);
 183                 }
 184         }
 185
 186         MySQLresult(SQLerror& e) : err(e)
 187         {
 188
 189         }
 190
 191         ~MySQLresult()
 192         {
 193         }
 194
 195         virtual int Rows()
 196         {
 197                 return rows;
 198         }
 199
 200         virtual void GetCols(std::vector<std::string>& result)
 201         {
 202                 result.assign(colnames.begin(), colnames.end());
 203         }
 204
 205         virtual SQLEntry GetValue(int row, int column)
 206         {
 207                 if ((row >= 0) && (row < rows) && (column >= 0) && (column < (int)fieldlists[row].size()))
 208                 {
 209                         return fieldlists[row][column];
 210                 }
 211                 return SQLEntry();
 212         }
 213
 214         virtual bool GetRow(SQLEntries& result)
 215         {
 216                 if (currentrow < rows)
 217                 {
 218                         result.assign(fieldlists[currentrow].begin(), fieldlists[currentrow].end());
 219                         currentrow++;
 220                         return true;
 221                 }
 222                 else
 223                 {
 224                         result.clear();
 225                         return false;
 226                 }
 227         }
 228 };
 229
 230 /** Represents a connection to a mysql database
 231  */
 232 class SQLConnection : public SQLProvider
 233 {
 234  public:
 235         reference<ConfigTag> config;
 236         MYSQL *connection;
 237         Mutex lock;
 238
 239         // This constructor creates an SQLConnection object with the given credentials, but does not connect yet.
 240         SQLConnection(Module* p, ConfigTag* tag) : SQLProvider(p, "SQL/" + tag->getString("id")),
 241                 config(tag), connection(NULL)
 242         {
 243         }
 244
 245         ~SQLConnection()
 246         {
 247                 Close();
 248         }
 249
 250         // This method connects to the database using the credentials supplied to the constructor, and returns
 251         // true upon success.
 252         bool Connect()
 253         {
 254                 unsigned int timeout = 1;
 255                 connection = mysql_init(connection);
 256                 mysql_options(connection,MYSQL_OPT_CONNECT_TIMEOUT,(char*)&timeout);
 257                 std::string host = config->getString("host");
 258                 std::string user = config->getString("user");
 259                 std::string pass = config->getString("pass");
 260                 std::string dbname = config->getString("name");
 261                 int port = config->getInt("port");
 262                 bool rv = mysql_real_connect(connection, host.c_str(), user.c_str(), pass.c_str(), dbname.c_str(), port, NULL, 0);
 263                 if (!rv)
 264                         return rv;
 265                 std::string initquery;
 266                 if (config->readString("initialquery", initquery))
 267                 {
 268                         mysql_query(connection,initquery.c_str());
 269                 }
 270                 return true;
 271         }
 272
 273         ModuleSQL* Parent()
 274         {
 275                 return (ModuleSQL*)(Module*)creator;
 276         }
 277
 278         MySQLresult* DoBlockingQuery(const std::string& query)
 279         {
 280
 281                 /* Parse the command string and dispatch it to mysql */
 282                 if (CheckConnection() && !mysql_real_query(connection, query.data(), query.length()))
 283                 {
 284                         /* Successfull query */
 285                         MYSQL_RES* res = mysql_use_result(connection);
 286                         unsigned long rows = mysql_affected_rows(connection);
 287                         return new MySQLresult(res, rows);
 288                 }
 289                 else
 290                 {
 291                         /* XXX: See /usr/include/mysql/mysqld_error.h for a list of
 292                          * possible error numbers and error messages */
 293                         SQLerror e(SQL_QREPLY_FAIL, ConvToStr(mysql_errno(connection)) + ": " + mysql_error(connection));
 294                         return new MySQLresult(e);
 295                 }
 296         }
 297
 298         bool CheckConnection()
 299         {
 300                 if (!connection || mysql_ping(connection) != 0)
 301                         return Connect();
 302                 return true;
 303         }
 304
 305         std::string GetError()
 306         {
 307                 return mysql_error(connection);
 308         }
 309
 310         void Close()
 311         {
 312                 mysql_close(connection);
 313         }
 314
 315         void submit(SQLQuery* q, const std::string& qs)
 316         {
 317                 Parent()->Dispatcher->LockQueue();
 318                 Parent()->qq.push_back(QQueueItem(q, qs, this));
 319                 Parent()->Dispatcher->UnlockQueueWakeup();
 320         }
 321
 322         void submit(SQLQuery* call, const std::string& q, const ParamL& p)
 323         {
 324                 std::string res;
 325                 unsigned int param = 0;
 326                 for(std::string::size_type i = 0; i < q.length(); i++)
 327                 {
 328                         if (q[i] != '?')
 329                                 res.push_back(q[i]);
 330                         else
 331                         {
 332                                 if (param < p.size())
 333                                 {
 334                                         std::string parm = p[param++];
 335                                         // In the worst case, each character may need to be encoded as using two bytes,
 336                                         // and one byte is the terminating null
 337                                         std::vector<char> buffer(parm.length() * 2 + 1);
 338
 339                                         // The return value of mysql_escape_string() is the length of the encoded string,
 340                                         // not including the terminating null
 341                                         unsigned long escapedsize = mysql_escape_string(&buffer[0], parm.c_str(), parm.length());
 342 //                                      mysql_real_escape_string(connection, queryend, paramscopy[paramnum].c_str(), paramscopy[paramnum].length());
 343                                         res.append(&buffer[0], escapedsize);
 344                                 }
 345                         }
 346                 }
 347                 submit(call, res);
 348         }
 349
 350         void submit(SQLQuery* call, const std::string& q, const ParamM& p)
 351         {
 352                 std::string res;
 353                 for(std::string::size_type i = 0; i < q.length(); i++)
 354                 {
 355                         if (q[i] != '$')
 356                                 res.push_back(q[i]);
 357                         else
 358                         {
 359                                 std::string field;
 360                                 i++;
 361                                 while (i < q.length() && isalnum(q[i]))
 362                                         field.push_back(q[i++]);
 363                                 i--;
 364
 365                                 ParamM::const_iterator it = p.find(field);
 366                                 if (it != p.end())
 367                                 {
 368                                         std::string parm = it->second;
 369                                         // NOTE: See above
 370                                         std::vector<char> buffer(parm.length() * 2 + 1);
 371                                         unsigned long escapedsize = mysql_escape_string(&buffer[0], parm.c_str(), parm.length());
 372                                         res.append(&buffer[0], escapedsize);
 373                                 }
 374                         }
 375                 }
 376                 submit(call, res);
 377         }
 378 };
 379
 380 ModuleSQL::ModuleSQL()
 381 {
 382         Dispatcher = NULL;
 383 }
 384
 385 void ModuleSQL::init()
 386 {
 387         Dispatcher = new DispatcherThread(this);
 388         ServerInstance->Threads->Start(Dispatcher);
 389
 390         Implementation eventlist[] = { I_OnRehash, I_OnUnloadModule };
 391         ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 392
 393         OnRehash(NULL);
 394 }
 395
 396 ModuleSQL::~ModuleSQL()
 397 {
 398         if (Dispatcher)
 399         {
 400                 Dispatcher->join();
 401                 Dispatcher->OnNotify();
 402                 delete Dispatcher;
 403         }
 404         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 405         {
 406                 delete i->second;
 407         }
 408 }
 409
 410 void ModuleSQL::OnRehash(User* user)
 411 {
 412         ConnMap conns;
 413         ConfigTagList tags = ServerInstance->Config->ConfTags("database");
 414         for(ConfigIter i = tags.first; i != tags.second; i++)
 415         {
 416                 if (i->second->getString("module", "mysql") != "mysql")
 417                         continue;
 418                 std::string id = i->second->getString("id");
 419                 ConnMap::iterator curr = connections.find(id);
 420                 if (curr == connections.end())
 421                 {
 422                         SQLConnection* conn = new SQLConnection(this, i->second);
 423                         conns.insert(std::make_pair(id, conn));
 424                         ServerInstance->Modules->AddService(*conn);
 425                 }
 426                 else
 427                 {
 428                         conns.insert(*curr);
 429                         connections.erase(curr);
 430                 }
 431         }
 432
 433         // now clean up the deleted databases
 434         Dispatcher->LockQueue();
 435         SQLerror err(SQL_BAD_DBID);
 436         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 437         {
 438                 ServerInstance->Modules->DelService(*i->second);
 439                 // it might be running a query on this database. Wait for that to complete
 440                 i->second->lock.Lock();
 441                 i->second->lock.Unlock();
 442                 // now remove all active queries to this DB
 443                 for (size_t j = qq.size(); j > 0; j--)
 444                 {
 445                         size_t k = j - 1;
 446                         if (qq[k].c == i->second)
 447                         {
 448                                 qq[k].q->OnError(err);
 449                                 delete qq[k].q;
 450                                 qq.erase(qq.begin() + k);
 451                         }
 452                 }
 453                 // finally, nuke the connection
 454                 delete i->second;
 455         }
 456         Dispatcher->UnlockQueue();
 457         connections.swap(conns);
 458 }
 459
 460 void ModuleSQL::OnUnloadModule(Module* mod)
 461 {
 462         SQLerror err(SQL_BAD_DBID);
 463         Dispatcher->LockQueue();
 464         unsigned int i = qq.size();
 465         while (i > 0)
 466         {
 467                 i--;
 468                 if (qq[i].q->creator == mod)
 469                 {
 470                         if (i == 0)
 471                         {
 472                                 // need to wait until the query is done
 473                                 // (the result will be discarded)
 474                                 qq[i].c->lock.Lock();
 475                                 qq[i].c->lock.Unlock();
 476                         }
 477                         qq[i].q->OnError(err);
 478                         delete qq[i].q;
 479                         qq.erase(qq.begin() + i);
 480                 }
 481         }
 482         Dispatcher->UnlockQueue();
 483         // clean up any result queue entries
 484         Dispatcher->OnNotify();
 485 }
 486
 487 Version ModuleSQL::GetVersion()
 488 {
 489         return Version("MySQL support", VF_VENDOR);
 490 }
 491
 492 void DispatcherThread::Run()
 493 {
 494         this->LockQueue();
 495         while (!this->GetExitFlag())
 496         {
 497                 if (!Parent->qq.empty())
 498                 {
 499                         QQueueItem i = Parent->qq.front();
 500                         i.c->lock.Lock();
 501                         this->UnlockQueue();
 502                         MySQLresult* res = i.c->DoBlockingQuery(i.query);
 503                         i.c->lock.Unlock();
 504
 505                         /*
 506                          * At this point, the main thread could be working on:
 507                          *  Rehash - delete i.c out from under us. We don't care about that.
 508                          *  UnloadModule - delete i.q and the qq item. Need to avoid reporting results.
 509                          */
 510
 511                         this->LockQueue();
 512                         if (!Parent->qq.empty() && Parent->qq.front().q == i.q)
 513                         {
 514                                 Parent->qq.pop_front();
 515                                 Parent->rq.push_back(RQueueItem(i.q, res));
 516                                 NotifyParent();
 517                         }
 518                         else
 519                         {
 520                                 // UnloadModule ate the query
 521                                 delete res;
 522                         }
 523                 }
 524                 else
 525                 {
 526                         /* We know the queue is empty, we can safely hang this thread until
 527                          * something happens
 528                          */
 529                         this->WaitForQueue();
 530                 }
 531         }
 532         this->UnlockQueue();
 533 }
 534
 535 void DispatcherThread::OnNotify()
 536 {
 537         // this could unlock during the dispatch, but OnResult isn't expected to take that long
 538         this->LockQueue();
 539         for(ResultQueue::iterator i = Parent->rq.begin(); i != Parent->rq.end(); i++)
 540         {
 541                 MySQLresult* res = i->r;
 542                 if (res->err.id == SQL_NO_ERROR)
 543                         i->q->OnResult(*res);
 544                 else
 545                         i->q->OnError(res->err);
 546                 delete i->q;
 547                 delete i->r;
 548         }
 549         Parent->rq.clear();
 550         this->UnlockQueue();
 551 }
 552
 553 MODULE_INIT(ModuleSQL)