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