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 "modules/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                         res = NULL;
 184                 }
 185         }
 186
 187         MySQLresult(SQLerror& e) : err(e)
 188         {
 189
 190         }
 191
 192         virtual int Rows()
 193         {
 194                 return rows;
 195         }
 196
 197         virtual void GetCols(std::vector<std::string>& result)
 198         {
 199                 result.assign(colnames.begin(), colnames.end());
 200         }
 201
 202         virtual 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         virtual 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                 std::string initquery;
 263                 if (config->readString("initialquery", initquery))
 264                 {
 265                         mysql_query(connection,initquery.c_str());
 266                 }
 267                 return true;
 268         }
 269
 270         ModuleSQL* Parent()
 271         {
 272                 return (ModuleSQL*)(Module*)creator;
 273         }
 274
 275         MySQLresult* DoBlockingQuery(const std::string& query)
 276         {
 277
 278                 /* Parse the command string and dispatch it to mysql */
 279                 if (CheckConnection() && !mysql_real_query(connection, query.data(), query.length()))
 280                 {
 281                         /* Successfull query */
 282                         MYSQL_RES* res = mysql_use_result(connection);
 283                         unsigned long rows = mysql_affected_rows(connection);
 284                         return new MySQLresult(res, rows);
 285                 }
 286                 else
 287                 {
 288                         /* XXX: See /usr/include/mysql/mysqld_error.h for a list of
 289                          * possible error numbers and error messages */
 290                         SQLerror e(SQL_QREPLY_FAIL, ConvToStr(mysql_errno(connection)) + ": " + mysql_error(connection));
 291                         return new MySQLresult(e);
 292                 }
 293         }
 294
 295         bool CheckConnection()
 296         {
 297                 if (!connection || mysql_ping(connection) != 0)
 298                         return Connect();
 299                 return true;
 300         }
 301
 302         std::string GetError()
 303         {
 304                 return mysql_error(connection);
 305         }
 306
 307         void Close()
 308         {
 309                 mysql_close(connection);
 310         }
 311
 312         void submit(SQLQuery* q, const std::string& qs)
 313         {
 314                 Parent()->Dispatcher->LockQueue();
 315                 Parent()->qq.push_back(QQueueItem(q, qs, this));
 316                 Parent()->Dispatcher->UnlockQueueWakeup();
 317         }
 318
 319         void submit(SQLQuery* call, const std::string& q, const ParamL& p)
 320         {
 321                 std::string res;
 322                 unsigned int param = 0;
 323                 for(std::string::size_type i = 0; i < q.length(); i++)
 324                 {
 325                         if (q[i] != '?')
 326                                 res.push_back(q[i]);
 327                         else
 328                         {
 329                                 if (param < p.size())
 330                                 {
 331                                         std::string parm = p[param++];
 332                                         char buffer[MAXBUF];
 333                                         mysql_escape_string(buffer, parm.c_str(), parm.length());
 334 //                                      mysql_real_escape_string(connection, queryend, paramscopy[paramnum].c_str(), paramscopy[paramnum].length());
 335                                         res.append(buffer);
 336                                 }
 337                         }
 338                 }
 339                 submit(call, res);
 340         }
 341
 342         void submit(SQLQuery* call, const std::string& q, const ParamM& p)
 343         {
 344                 std::string res;
 345                 for(std::string::size_type i = 0; i < q.length(); i++)
 346                 {
 347                         if (q[i] != '$')
 348                                 res.push_back(q[i]);
 349                         else
 350                         {
 351                                 std::string field;
 352                                 i++;
 353                                 while (i < q.length() && isalnum(q[i]))
 354                                         field.push_back(q[i++]);
 355                                 i--;
 356
 357                                 ParamM::const_iterator it = p.find(field);
 358                                 if (it != p.end())
 359                                 {
 360                                         std::string parm = it->second;
 361                                         char buffer[MAXBUF];
 362                                         mysql_escape_string(buffer, parm.c_str(), parm.length());
 363                                         res.append(buffer);
 364                                 }
 365                         }
 366                 }
 367                 submit(call, res);
 368         }
 369 };
 370
 371 ModuleSQL::ModuleSQL()
 372 {
 373         Dispatcher = NULL;
 374 }
 375
 376 void ModuleSQL::init()
 377 {
 378         Dispatcher = new DispatcherThread(this);
 379         ServerInstance->Threads->Start(Dispatcher);
 380
 381         Implementation eventlist[] = { I_OnRehash, I_OnUnloadModule };
 382         ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 383
 384         OnRehash(NULL);
 385 }
 386
 387 ModuleSQL::~ModuleSQL()
 388 {
 389         if (Dispatcher)
 390         {
 391                 Dispatcher->join();
 392                 Dispatcher->OnNotify();
 393                 delete Dispatcher;
 394         }
 395         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 396         {
 397                 delete i->second;
 398         }
 399 }
 400
 401 void ModuleSQL::OnRehash(User* user)
 402 {
 403         ConnMap conns;
 404         ConfigTagList tags = ServerInstance->Config->ConfTags("database");
 405         for(ConfigIter i = tags.first; i != tags.second; i++)
 406         {
 407                 if (i->second->getString("module", "mysql") != "mysql")
 408                         continue;
 409                 std::string id = i->second->getString("id");
 410                 ConnMap::iterator curr = connections.find(id);
 411                 if (curr == connections.end())
 412                 {
 413                         SQLConnection* conn = new SQLConnection(this, i->second);
 414                         conns.insert(std::make_pair(id, conn));
 415                         ServerInstance->Modules->AddService(*conn);
 416                 }
 417                 else
 418                 {
 419                         conns.insert(*curr);
 420                         connections.erase(curr);
 421                 }
 422         }
 423
 424         // now clean up the deleted databases
 425         Dispatcher->LockQueue();
 426         SQLerror err(SQL_BAD_DBID);
 427         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 428         {
 429                 ServerInstance->Modules->DelService(*i->second);
 430                 // it might be running a query on this database. Wait for that to complete
 431                 i->second->lock.Lock();
 432                 i->second->lock.Unlock();
 433                 // now remove all active queries to this DB
 434                 for(unsigned int j = qq.size() - 1; j >= 0; j--)
 435                 {
 436                         if (qq[j].c == i->second)
 437                         {
 438                                 qq[j].q->OnError(err);
 439                                 delete qq[j].q;
 440                                 qq.erase(qq.begin() + j);
 441                         }
 442                 }
 443                 // finally, nuke the connection
 444                 delete i->second;
 445         }
 446         Dispatcher->UnlockQueue();
 447         connections.swap(conns);
 448 }
 449
 450 void ModuleSQL::OnUnloadModule(Module* mod)
 451 {
 452         SQLerror err(SQL_BAD_DBID);
 453         Dispatcher->LockQueue();
 454         unsigned int i = qq.size();
 455         while (i > 0)
 456         {
 457                 i--;
 458                 if (qq[i].q->creator == mod)
 459                 {
 460                         if (i == 0)
 461                         {
 462                                 // need to wait until the query is done
 463                                 // (the result will be discarded)
 464                                 qq[i].c->lock.Lock();
 465                                 qq[i].c->lock.Unlock();
 466                         }
 467                         qq[i].q->OnError(err);
 468                         delete qq[i].q;
 469                         qq.erase(qq.begin() + i);
 470                 }
 471         }
 472         Dispatcher->UnlockQueue();
 473         // clean up any result queue entries
 474         Dispatcher->OnNotify();
 475 }
 476
 477 Version ModuleSQL::GetVersion()
 478 {
 479         return Version("MySQL support", VF_VENDOR);
 480 }
 481
 482 void DispatcherThread::Run()
 483 {
 484         this->LockQueue();
 485         while (!this->GetExitFlag())
 486         {
 487                 if (!Parent->qq.empty())
 488                 {
 489                         QQueueItem i = Parent->qq.front();
 490                         i.c->lock.Lock();
 491                         this->UnlockQueue();
 492                         MySQLresult* res = i.c->DoBlockingQuery(i.query);
 493                         i.c->lock.Unlock();
 494
 495                         /*
 496                          * At this point, the main thread could be working on:
 497                          *  Rehash - delete i.c out from under us. We don't care about that.
 498                          *  UnloadModule - delete i.q and the qq item. Need to avoid reporting results.
 499                          */
 500
 501                         this->LockQueue();
 502                         if (!Parent->qq.empty() && Parent->qq.front().q == i.q)
 503                         {
 504                                 Parent->qq.pop_front();
 505                                 Parent->rq.push_back(RQueueItem(i.q, res));
 506                                 NotifyParent();
 507                         }
 508                         else
 509                         {
 510                                 // UnloadModule ate the query
 511                                 delete res;
 512                         }
 513                 }
 514                 else
 515                 {
 516                         /* We know the queue is empty, we can safely hang this thread until
 517                          * something happens
 518                          */
 519                         this->WaitForQueue();
 520                 }
 521         }
 522         this->UnlockQueue();
 523 }
 524
 525 void DispatcherThread::OnNotify()
 526 {
 527         // this could unlock during the dispatch, but OnResult isn't expected to take that long
 528         this->LockQueue();
 529         for(ResultQueue::iterator i = Parent->rq.begin(); i != Parent->rq.end(); i++)
 530         {
 531                 MySQLresult* res = i->r;
 532                 if (res->err.id == SQL_NO_ERROR)
 533                         i->q->OnResult(*res);
 534                 else
 535                         i->q->OnError(res->err);
 536                 delete i->q;
 537                 delete i->r;
 538         }
 539         Parent->rq.clear();
 540         this->UnlockQueue();
 541 }
 542
 543 MODULE_INIT(ModuleSQL)