src/modules/extra/m_mysql.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2010 InspIRCd Development Team
   6  * See: http://wiki.inspircd.org/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *          the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 /* Stop mysql wanting to use long long */
  15 #define NO_CLIENT_LONG_LONG
  16
  17 #include "inspircd.h"
  18 #include <mysql.h>
  19 #include "sql.h"
  20
  21 #ifdef WINDOWS
  22 #pragma comment(lib, "mysqlclient.lib")
  23 #endif
  24
  25 /* VERSION 3 API: With nonblocking (threaded) requests */
  26
  27 /* $ModDesc: SQL Service Provider module for all other m_sql* modules */
  28 /* $CompileFlags: exec("mysql_config --include") */
  29 /* $LinkerFlags: exec("mysql_config --libs_r") rpath("mysql_config --libs_r") */
  30 /* $ModDep: m_sqlv2.h */
  31
  32 /* THE NONBLOCKING MYSQL API!
  33  *
  34  * MySQL provides no nonblocking (asyncronous) API of its own, and its developers recommend
  35  * that instead, you should thread your program. This is what i've done here to allow for
  36  * asyncronous SQL requests via mysql. The way this works is as follows:
  37  *
  38  * The module spawns a thread via class Thread, and performs its mysql queries in this thread,
  39  * using a queue with priorities. There is a mutex on either end which prevents two threads
  40  * adjusting the queue at the same time, and crashing the ircd. Every 50 milliseconds, the
  41  * worker thread wakes up, and checks if there is a request at the head of its queue.
  42  * If there is, it processes this request, blocking the worker thread but leaving the ircd
  43  * thread to go about its business as usual. During this period, the ircd thread is able
  44  * to insert futher pending requests into the queue.
  45  *
  46  * Once the processing of a request is complete, it is removed from the incoming queue to
  47  * an outgoing queue, and initialized as a 'response'. The worker thread then signals the
  48  * ircd thread (via a loopback socket) of the fact a result is available, by sending the
  49  * connection ID through the connection.
  50  *
  51  * The ircd thread then mutexes the queue once more, reads the outbound response off the head
  52  * of the queue, and sends it on its way to the original calling module.
  53  *
  54  * XXX: You might be asking "why doesnt he just send the response from within the worker thread?"
  55  * The answer to this is simple. The majority of InspIRCd, and in fact most ircd's are not
  56  * threadsafe. This module is designed to be threadsafe and is careful with its use of threads,
  57  * however, if we were to call a module's OnRequest even from within a thread which was not the
  58  * one the module was originally instantiated upon, there is a chance of all hell breaking loose
  59  * if a module is ever put in a re-enterant state (stack corruption could occur, crashes, data
  60  * corruption, and worse, so DONT think about it until the day comes when InspIRCd is 100%
  61  * gauranteed threadsafe!)
  62  *
  63  * For a diagram of this system please see http://wiki.inspircd.org/Mysql2
  64  */
  65
  66 class SQLConnection;
  67 class MySQLresult;
  68 class DispatcherThread;
  69
  70 struct QQueueItem
  71 {
  72         SQLQuery* q;
  73         std::string query;
  74         SQLConnection* c;
  75         QQueueItem(SQLQuery* Q, const std::string& S, SQLConnection* C) : q(Q), query(S), c(C) {}
  76 };
  77
  78 struct RQueueItem
  79 {
  80         SQLQuery* q;
  81         MySQLresult* r;
  82         RQueueItem(SQLQuery* Q, MySQLresult* R) : q(Q), r(R) {}
  83 };
  84
  85 typedef std::map<std::string, SQLConnection*> ConnMap;
  86 typedef std::deque<QQueueItem> QueryQueue;
  87 typedef std::deque<RQueueItem> ResultQueue;
  88
  89 /** MySQL module
  90  *  */
  91 class ModuleSQL : public Module
  92 {
  93  public:
  94         DispatcherThread* Dispatcher;
  95         QueryQueue qq;       // MUST HOLD MUTEX
  96         ResultQueue rq;      // MUST HOLD MUTEX
  97         ConnMap connections; // main thread only
  98
  99         ModuleSQL();
 100         void init();
 101         ~ModuleSQL();
 102         void OnRehash(User* user);
 103         void OnUnloadModule(Module* mod);
 104         Version GetVersion();
 105 };
 106
 107 class DispatcherThread : public SocketThread
 108 {
 109  private:
 110         ModuleSQL* const Parent;
 111  public:
 112         DispatcherThread(ModuleSQL* CreatorModule) : Parent(CreatorModule) { }
 113         ~DispatcherThread() { }
 114         virtual void Run();
 115         virtual void OnNotify();
 116 };
 117
 118 #if !defined(MYSQL_VERSION_ID) || MYSQL_VERSION_ID<32224
 119 #define mysql_field_count mysql_num_fields
 120 #endif
 121
 122 /** Represents a mysql result set
 123  */
 124 class MySQLresult : public SQLResult
 125 {
 126  public:
 127         SQLerror err;
 128         int currentrow;
 129         int rows;
 130         std::vector<std::string> colnames;
 131         std::vector<SQLEntries> fieldlists;
 132
 133         MySQLresult(MYSQL_RES* res, int affected_rows) : err(SQL_NO_ERROR), currentrow(0), rows(0)
 134         {
 135                 if (affected_rows >= 1)
 136                 {
 137                         rows = affected_rows;
 138                         fieldlists.resize(rows);
 139                 }
 140                 unsigned int field_count = 0;
 141                 if (res)
 142                 {
 143                         MYSQL_ROW row;
 144                         int n = 0;
 145                         while ((row = mysql_fetch_row(res)))
 146                         {
 147                                 if (fieldlists.size() < (unsigned int)rows+1)
 148                                 {
 149                                         fieldlists.resize(fieldlists.size()+1);
 150                                 }
 151                                 field_count = 0;
 152                                 MYSQL_FIELD *fields = mysql_fetch_fields(res);
 153                                 if(mysql_num_fields(res) == 0)
 154                                         break;
 155                                 if (fields && mysql_num_fields(res))
 156                                 {
 157                                         colnames.clear();
 158                                         while (field_count < mysql_num_fields(res))
 159                                         {
 160                                                 std::string a = (fields[field_count].name ? fields[field_count].name : "");
 161                                                 if (row[field_count])
 162                                                         fieldlists[n].push_back(SQLEntry(row[field_count]));
 163                                                 else
 164                                                         fieldlists[n].push_back(SQLEntry());
 165                                                 colnames.push_back(a);
 166                                                 field_count++;
 167                                         }
 168                                         n++;
 169                                 }
 170                                 rows++;
 171                         }
 172                         mysql_free_result(res);
 173                         res = NULL;
 174                 }
 175         }
 176
 177         MySQLresult(SQLerror& e) : err(e)
 178         {
 179
 180         }
 181
 182         ~MySQLresult()
 183         {
 184         }
 185
 186         virtual int Rows()
 187         {
 188                 return rows;
 189         }
 190
 191         virtual void GetCols(std::vector<std::string>& result)
 192         {
 193                 result.assign(colnames.begin(), colnames.end());
 194         }
 195
 196         virtual SQLEntry GetValue(int row, int column)
 197         {
 198                 if ((row >= 0) && (row < rows) && (column >= 0) && (column < (int)fieldlists[row].size()))
 199                 {
 200                         return fieldlists[row][column];
 201                 }
 202                 return SQLEntry();
 203         }
 204
 205         virtual bool GetRow(SQLEntries& result)
 206         {
 207                 if (currentrow < rows)
 208                 {
 209                         result.assign(fieldlists[currentrow].begin(), fieldlists[currentrow].end());
 210                         currentrow++;
 211                         return true;
 212                 }
 213                 else
 214                 {
 215                         result.clear();
 216                         return false;
 217                 }
 218         }
 219 };
 220
 221 /** Represents a connection to a mysql database
 222  */
 223 class SQLConnection : public SQLProvider
 224 {
 225  public:
 226         reference<ConfigTag> config;
 227         MYSQL *connection;
 228         Mutex lock;
 229
 230         // This constructor creates an SQLConnection object with the given credentials, but does not connect yet.
 231         SQLConnection(Module* p, ConfigTag* tag) : SQLProvider(p, "SQL/" + tag->getString("id")),
 232                 config(tag), connection(NULL)
 233         {
 234         }
 235
 236         ~SQLConnection()
 237         {
 238                 Close();
 239         }
 240
 241         // This method connects to the database using the credentials supplied to the constructor, and returns
 242         // true upon success.
 243         bool Connect()
 244         {
 245                 unsigned int timeout = 1;
 246                 connection = mysql_init(connection);
 247                 mysql_options(connection,MYSQL_OPT_CONNECT_TIMEOUT,(char*)&timeout);
 248                 std::string host = config->getString("host");
 249                 std::string user = config->getString("user");
 250                 std::string pass = config->getString("pass");
 251                 std::string dbname = config->getString("name");
 252                 int port = config->getInt("port");
 253                 bool rv = mysql_real_connect(connection, host.c_str(), user.c_str(), pass.c_str(), dbname.c_str(), port, NULL, 0);
 254                 if (!rv)
 255                         return rv;
 256                 std::string initquery;
 257                 if (config->readString("initialquery", initquery))
 258                 {
 259                         mysql_query(connection,initquery.c_str());
 260                 }
 261                 return true;
 262         }
 263
 264         ModuleSQL* Parent()
 265         {
 266                 return (ModuleSQL*)(Module*)creator;
 267         }
 268
 269         MySQLresult* DoBlockingQuery(const std::string& query)
 270         {
 271
 272                 /* Parse the command string and dispatch it to mysql */
 273                 if (CheckConnection() && !mysql_real_query(connection, query.data(), query.length()))
 274                 {
 275                         /* Successfull query */
 276                         MYSQL_RES* res = mysql_use_result(connection);
 277                         unsigned long rows = mysql_affected_rows(connection);
 278                         return new MySQLresult(res, rows);
 279                 }
 280                 else
 281                 {
 282                         /* XXX: See /usr/include/mysql/mysqld_error.h for a list of
 283                          * possible error numbers and error messages */
 284                         SQLerror e(SQL_QREPLY_FAIL, ConvToStr(mysql_errno(connection)) + std::string(": ") + mysql_error(connection));
 285                         return new MySQLresult(e);
 286                 }
 287         }
 288
 289         bool CheckConnection()
 290         {
 291                 if (!connection || mysql_ping(connection) != 0)
 292                         return Connect();
 293                 return true;
 294         }
 295
 296         std::string GetError()
 297         {
 298                 return mysql_error(connection);
 299         }
 300
 301         void Close()
 302         {
 303                 mysql_close(connection);
 304         }
 305
 306         void submit(SQLQuery* q, const std::string& qs)
 307         {
 308                 Parent()->Dispatcher->LockQueue();
 309                 Parent()->qq.push_back(QQueueItem(q, qs, this));
 310                 Parent()->Dispatcher->UnlockQueueWakeup();
 311         }
 312
 313         void submit(SQLQuery* call, const std::string& q, const ParamL& p)
 314         {
 315                 std::string res;
 316                 unsigned int param = 0;
 317                 for(std::string::size_type i = 0; i < q.length(); i++)
 318                 {
 319                         if (q[i] != '?')
 320                                 res.push_back(q[i]);
 321                         else
 322                         {
 323                                 if (param < p.size())
 324                                 {
 325                                         std::string parm = p[param++];
 326                                         char buffer[MAXBUF];
 327                                         mysql_escape_string(buffer, parm.c_str(), parm.length());
 328 //                                      mysql_real_escape_string(connection, queryend, paramscopy[paramnum].c_str(), paramscopy[paramnum].length());
 329                                         res.append(buffer);
 330                                 }
 331                         }
 332                 }
 333                 submit(call, res);
 334         }
 335
 336         void submit(SQLQuery* call, const std::string& q, const ParamM& p)
 337         {
 338                 std::string res;
 339                 for(std::string::size_type i = 0; i < q.length(); i++)
 340                 {
 341                         if (q[i] != '$')
 342                                 res.push_back(q[i]);
 343                         else
 344                         {
 345                                 std::string field;
 346                                 i++;
 347                                 while (i < q.length() && isalpha(q[i]))
 348                                         field.push_back(q[i++]);
 349                                 i--;
 350
 351                                 ParamM::const_iterator it = p.find(field);
 352                                 if (it != p.end())
 353                                 {
 354                                         std::string parm = it->second;
 355                                         char buffer[MAXBUF];
 356                                         mysql_escape_string(buffer, parm.c_str(), parm.length());
 357                                         res.append(buffer);
 358                                 }
 359                         }
 360                 }
 361                 submit(call, res);
 362         }
 363 };
 364
 365 ModuleSQL::ModuleSQL()
 366 {
 367         Dispatcher = NULL;
 368 }
 369
 370 void ModuleSQL::init()
 371 {
 372         Dispatcher = new DispatcherThread(this);
 373         ServerInstance->Threads->Start(Dispatcher);
 374
 375         Implementation eventlist[] = { I_OnRehash, I_OnUnloadModule };
 376         ServerInstance->Modules->Attach(eventlist, this, 2);
 377
 378         OnRehash(NULL);
 379 }
 380
 381 ModuleSQL::~ModuleSQL()
 382 {
 383         if (Dispatcher)
 384         {
 385                 Dispatcher->join();
 386                 Dispatcher->OnNotify();
 387                 delete Dispatcher;
 388         }
 389         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 390         {
 391                 delete i->second;
 392         }
 393 }
 394
 395 void ModuleSQL::OnRehash(User* user)
 396 {
 397         ConnMap conns;
 398         ConfigTagList tags = ServerInstance->Config->ConfTags("database");
 399         for(ConfigIter i = tags.first; i != tags.second; i++)
 400         {
 401                 if (i->second->getString("module", "mysql") != "mysql")
 402                         continue;
 403                 std::string id = i->second->getString("id");
 404                 ConnMap::iterator curr = connections.find(id);
 405                 if (curr == connections.end())
 406                 {
 407                         SQLConnection* conn = new SQLConnection(this, i->second);
 408                         conns.insert(std::make_pair(id, conn));
 409                         ServerInstance->Modules->AddService(*conn);
 410                 }
 411                 else
 412                 {
 413                         conns.insert(*curr);
 414                         connections.erase(curr);
 415                 }
 416         }
 417
 418         // now clean up the deleted databases
 419         Dispatcher->LockQueue();
 420         SQLerror err(SQL_BAD_DBID);
 421         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 422         {
 423                 ServerInstance->Modules->DelService(*i->second);
 424                 // it might be running a query on this database. Wait for that to complete
 425                 i->second->lock.Lock();
 426                 i->second->lock.Unlock();
 427                 // now remove all active queries to this DB
 428                 for(unsigned int j = qq.size() - 1; j >= 0; j--)
 429                 {
 430                         if (qq[j].c == i->second)
 431                         {
 432                                 qq[j].q->OnError(err);
 433                                 delete qq[j].q;
 434                                 qq.erase(qq.begin() + j);
 435                         }
 436                 }
 437                 // finally, nuke the connection
 438                 delete i->second;
 439         }
 440         Dispatcher->UnlockQueue();
 441         connections.swap(conns);
 442 }
 443
 444 void ModuleSQL::OnUnloadModule(Module* mod)
 445 {
 446         SQLerror err(SQL_BAD_DBID);
 447         Dispatcher->LockQueue();
 448         unsigned int i = qq.size();
 449         while (i > 0)
 450         {
 451                 i--;
 452                 if (qq[i].q->creator == mod)
 453                 {
 454                         if (i == 0)
 455                         {
 456                                 // need to wait until the query is done
 457                                 // (the result will be discarded)
 458                                 qq[i].c->lock.Lock();
 459                                 qq[i].c->lock.Unlock();
 460                         }
 461                         qq[i].q->OnError(err);
 462                         delete qq[i].q;
 463                         qq.erase(qq.begin() + i);
 464                 }
 465         }
 466         Dispatcher->UnlockQueue();
 467         // clean up any result queue entries
 468         Dispatcher->OnNotify();
 469 }
 470
 471 Version ModuleSQL::GetVersion()
 472 {
 473         return Version("MySQL support", VF_VENDOR);
 474 }
 475
 476 void DispatcherThread::Run()
 477 {
 478         this->LockQueue();
 479         while (!this->GetExitFlag())
 480         {
 481                 if (!Parent->qq.empty())
 482                 {
 483                         QQueueItem i = Parent->qq.front();
 484                         i.c->lock.Lock();
 485                         this->UnlockQueue();
 486                         MySQLresult* res = i.c->DoBlockingQuery(i.query);
 487                         i.c->lock.Unlock();
 488
 489                         /*
 490                          * At this point, the main thread could be working on:
 491                          *  Rehash - delete i.c out from under us. We don't care about that.
 492                          *  UnloadModule - delete i.q and the qq item. Need to avoid reporting results.
 493                          */
 494
 495                         this->LockQueue();
 496                         if (Parent->qq.front().q == i.q)
 497                         {
 498                                 Parent->qq.pop_front();
 499                                 Parent->rq.push_back(RQueueItem(i.q, res));
 500                                 NotifyParent();
 501                         }
 502                         else
 503                         {
 504                                 // UnloadModule ate the query
 505                                 delete res;
 506                         }
 507                 }
 508                 else
 509                 {
 510                         /* We know the queue is empty, we can safely hang this thread until
 511                          * something happens
 512                          */
 513                         this->WaitForQueue();
 514                 }
 515         }
 516         this->UnlockQueue();
 517 }
 518
 519 void DispatcherThread::OnNotify()
 520 {
 521         // this could unlock during the dispatch, but OnResult isn't expected to take that long
 522         this->LockQueue();
 523         for(ResultQueue::iterator i = Parent->rq.begin(); i != Parent->rq.end(); i++)
 524         {
 525                 MySQLresult* res = i->r;
 526                 if (res->err.id == SQL_NO_ERROR)
 527                         i->q->OnResult(*res);
 528                 else
 529                         i->q->OnError(res->err);
 530                 delete i->q;
 531                 delete i->r;
 532         }
 533         Parent->rq.clear();
 534         this->UnlockQueue();
 535 }
 536
 537 MODULE_INIT(ModuleSQL)