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