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 /// $CompilerFlags: execute("mysql_config --include" "MYSQL_CXXFLAGS")
  23 /// $LinkerFlags: execute("mysql_config --libs_r" "MYSQL_LDFLAGS" "-lmysqlclient")
  24
  25 /// $PackageInfo: require_system("centos" "6.0" "6.99") mysql-devel
  26 /// $PackageInfo: require_system("centos" "7.0") mariadb-devel
  27 /// $PackageInfo: require_system("darwin") mysql-connector-c
  28 /// $PackageInfo: require_system("ubuntu") libmysqlclient-dev
  29
  30
  31 // Fix warnings about the use of `long long` on C++03.
  32 #if defined __clang__
  33 # pragma clang diagnostic ignored "-Wc++11-long-long"
  34 #elif defined __GNUC__
  35 # pragma GCC diagnostic ignored "-Wlong-long"
  36 #endif
  37
  38 #include "inspircd.h"
  39 #include <mysql.h>
  40 #include "modules/sql.h"
  41
  42 #ifdef _WIN32
  43 # pragma comment(lib, "libmysql.lib")
  44 #endif
  45
  46 /* VERSION 3 API: With nonblocking (threaded) requests */
  47
  48 /* THE NONBLOCKING MYSQL API!
  49  *
  50  * MySQL provides no nonblocking (asyncronous) API of its own, and its developers recommend
  51  * that instead, you should thread your program. This is what i've done here to allow for
  52  * asyncronous SQL requests via mysql. The way this works is as follows:
  53  *
  54  * The module spawns a thread via class Thread, and performs its mysql queries in this thread,
  55  * using a queue with priorities. There is a mutex on either end which prevents two threads
  56  * adjusting the queue at the same time, and crashing the ircd. Every 50 milliseconds, the
  57  * worker thread wakes up, and checks if there is a request at the head of its queue.
  58  * If there is, it processes this request, blocking the worker thread but leaving the ircd
  59  * thread to go about its business as usual. During this period, the ircd thread is able
  60  * to insert futher pending requests into the queue.
  61  *
  62  * Once the processing of a request is complete, it is removed from the incoming queue to
  63  * an outgoing queue, and initialized as a 'response'. The worker thread then signals the
  64  * ircd thread (via a loopback socket) of the fact a result is available, by sending the
  65  * connection ID through the connection.
  66  *
  67  * The ircd thread then mutexes the queue once more, reads the outbound response off the head
  68  * of the queue, and sends it on its way to the original calling module.
  69  *
  70  * XXX: You might be asking "why doesnt he just send the response from within the worker thread?"
  71  * The answer to this is simple. The majority of InspIRCd, and in fact most ircd's are not
  72  * threadsafe. This module is designed to be threadsafe and is careful with its use of threads,
  73  * however, if we were to call a module's OnRequest even from within a thread which was not the
  74  * one the module was originally instantiated upon, there is a chance of all hell breaking loose
  75  * if a module is ever put in a re-enterant state (stack corruption could occur, crashes, data
  76  * corruption, and worse, so DONT think about it until the day comes when InspIRCd is 100%
  77  * gauranteed threadsafe!)
  78  *
  79  * For a diagram of this system please see http://wiki.inspircd.org/Mysql2
  80  */
  81
  82 class SQLConnection;
  83 class MySQLresult;
  84 class DispatcherThread;
  85
  86 struct QQueueItem
  87 {
  88         SQLQuery* q;
  89         std::string query;
  90         SQLConnection* c;
  91         QQueueItem(SQLQuery* Q, const std::string& S, SQLConnection* C) : q(Q), query(S), c(C) {}
  92 };
  93
  94 struct RQueueItem
  95 {
  96         SQLQuery* q;
  97         MySQLresult* r;
  98         RQueueItem(SQLQuery* Q, MySQLresult* R) : q(Q), r(R) {}
  99 };
 100
 101 typedef insp::flat_map<std::string, SQLConnection*> ConnMap;
 102 typedef std::deque<QQueueItem> QueryQueue;
 103 typedef std::deque<RQueueItem> ResultQueue;
 104
 105 /** MySQL module
 106  *  */
 107 class ModuleSQL : public Module
 108 {
 109  public:
 110         DispatcherThread* Dispatcher;
 111         QueryQueue qq;       // MUST HOLD MUTEX
 112         ResultQueue rq;      // MUST HOLD MUTEX
 113         ConnMap connections; // main thread only
 114
 115         ModuleSQL();
 116         void init() CXX11_OVERRIDE;
 117         ~ModuleSQL();
 118         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE;
 119         void OnUnloadModule(Module* mod) CXX11_OVERRIDE;
 120         Version GetVersion() CXX11_OVERRIDE;
 121 };
 122
 123 class DispatcherThread : public SocketThread
 124 {
 125  private:
 126         ModuleSQL* const Parent;
 127  public:
 128         DispatcherThread(ModuleSQL* CreatorModule) : Parent(CreatorModule) { }
 129         ~DispatcherThread() { }
 130         void Run();
 131         void OnNotify();
 132 };
 133
 134 #if !defined(MYSQL_VERSION_ID) || MYSQL_VERSION_ID<32224
 135 #define mysql_field_count mysql_num_fields
 136 #endif
 137
 138 /** Represents a mysql result set
 139  */
 140 class MySQLresult : public SQLResult
 141 {
 142  public:
 143         SQLerror err;
 144         int currentrow;
 145         int rows;
 146         std::vector<std::string> colnames;
 147         std::vector<SQLEntries> fieldlists;
 148
 149         MySQLresult(MYSQL_RES* res, int affected_rows) : err(SQL_NO_ERROR), currentrow(0), rows(0)
 150         {
 151                 if (affected_rows >= 1)
 152                 {
 153                         rows = affected_rows;
 154                         fieldlists.resize(rows);
 155                 }
 156                 unsigned int field_count = 0;
 157                 if (res)
 158                 {
 159                         MYSQL_ROW row;
 160                         int n = 0;
 161                         while ((row = mysql_fetch_row(res)))
 162                         {
 163                                 if (fieldlists.size() < (unsigned int)rows+1)
 164                                 {
 165                                         fieldlists.resize(fieldlists.size()+1);
 166                                 }
 167                                 field_count = 0;
 168                                 MYSQL_FIELD *fields = mysql_fetch_fields(res);
 169                                 if(mysql_num_fields(res) == 0)
 170                                         break;
 171                                 if (fields && mysql_num_fields(res))
 172                                 {
 173                                         colnames.clear();
 174                                         while (field_count < mysql_num_fields(res))
 175                                         {
 176                                                 std::string a = (fields[field_count].name ? fields[field_count].name : "");
 177                                                 if (row[field_count])
 178                                                         fieldlists[n].push_back(SQLEntry(row[field_count]));
 179                                                 else
 180                                                         fieldlists[n].push_back(SQLEntry());
 181                                                 colnames.push_back(a);
 182                                                 field_count++;
 183                                         }
 184                                         n++;
 185                                 }
 186                                 rows++;
 187                         }
 188                         mysql_free_result(res);
 189                 }
 190         }
 191
 192         MySQLresult(SQLerror& e) : err(e)
 193         {
 194
 195         }
 196
 197         int Rows()
 198         {
 199                 return rows;
 200         }
 201
 202         void GetCols(std::vector<std::string>& result)
 203         {
 204                 result.assign(colnames.begin(), colnames.end());
 205         }
 206
 207         SQLEntry GetValue(int row, int column)
 208         {
 209                 if ((row >= 0) && (row < rows) && (column >= 0) && (column < (int)fieldlists[row].size()))
 210                 {
 211                         return fieldlists[row][column];
 212                 }
 213                 return SQLEntry();
 214         }
 215
 216         bool GetRow(SQLEntries& result)
 217         {
 218                 if (currentrow < rows)
 219                 {
 220                         result.assign(fieldlists[currentrow].begin(), fieldlists[currentrow].end());
 221                         currentrow++;
 222                         return true;
 223                 }
 224                 else
 225                 {
 226                         result.clear();
 227                         return false;
 228                 }
 229         }
 230 };
 231
 232 /** Represents a connection to a mysql database
 233  */
 234 class SQLConnection : public SQLProvider
 235 {
 236  public:
 237         reference<ConfigTag> config;
 238         MYSQL *connection;
 239         Mutex lock;
 240
 241         // This constructor creates an SQLConnection object with the given credentials, but does not connect yet.
 242         SQLConnection(Module* p, ConfigTag* tag) : SQLProvider(p, "SQL/" + tag->getString("id")),
 243                 config(tag), connection(NULL)
 244         {
 245         }
 246
 247         ~SQLConnection()
 248         {
 249                 Close();
 250         }
 251
 252         // This method connects to the database using the credentials supplied to the constructor, and returns
 253         // true upon success.
 254         bool Connect()
 255         {
 256                 unsigned int timeout = 1;
 257                 connection = mysql_init(connection);
 258                 mysql_options(connection,MYSQL_OPT_CONNECT_TIMEOUT,(char*)&timeout);
 259                 std::string host = config->getString("host");
 260                 std::string user = config->getString("user");
 261                 std::string pass = config->getString("pass");
 262                 std::string dbname = config->getString("name");
 263                 int port = config->getInt("port");
 264                 bool rv = mysql_real_connect(connection, host.c_str(), user.c_str(), pass.c_str(), dbname.c_str(), port, NULL, 0);
 265                 if (!rv)
 266                         return rv;
 267
 268                 // Enable character set settings
 269                 std::string charset = config->getString("charset");
 270                 if ((!charset.empty()) && (mysql_set_character_set(connection, charset.c_str())))
 271                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "WARNING: Could not set character set to \"%s\"", charset.c_str());
 272
 273                 std::string initquery;
 274                 if (config->readString("initialquery", initquery))
 275                 {
 276                         mysql_query(connection,initquery.c_str());
 277                 }
 278                 return true;
 279         }
 280
 281         ModuleSQL* Parent()
 282         {
 283                 return (ModuleSQL*)(Module*)creator;
 284         }
 285
 286         MySQLresult* DoBlockingQuery(const std::string& query)
 287         {
 288
 289                 /* Parse the command string and dispatch it to mysql */
 290                 if (CheckConnection() && !mysql_real_query(connection, query.data(), query.length()))
 291                 {
 292                         /* Successfull query */
 293                         MYSQL_RES* res = mysql_use_result(connection);
 294                         unsigned long rows = mysql_affected_rows(connection);
 295                         return new MySQLresult(res, rows);
 296                 }
 297                 else
 298                 {
 299                         /* XXX: See /usr/include/mysql/mysqld_error.h for a list of
 300                          * possible error numbers and error messages */
 301                         SQLerror e(SQL_QREPLY_FAIL, ConvToStr(mysql_errno(connection)) + ": " + mysql_error(connection));
 302                         return new MySQLresult(e);
 303                 }
 304         }
 305
 306         bool CheckConnection()
 307         {
 308                 if (!connection || mysql_ping(connection) != 0)
 309                         return Connect();
 310                 return true;
 311         }
 312
 313         std::string GetError()
 314         {
 315                 return mysql_error(connection);
 316         }
 317
 318         void Close()
 319         {
 320                 mysql_close(connection);
 321         }
 322
 323         void submit(SQLQuery* q, const std::string& qs)
 324         {
 325                 Parent()->Dispatcher->LockQueue();
 326                 Parent()->qq.push_back(QQueueItem(q, qs, this));
 327                 Parent()->Dispatcher->UnlockQueueWakeup();
 328         }
 329
 330         void submit(SQLQuery* call, const std::string& q, const ParamL& p)
 331         {
 332                 std::string res;
 333                 unsigned int param = 0;
 334                 for(std::string::size_type i = 0; i < q.length(); i++)
 335                 {
 336                         if (q[i] != '?')
 337                                 res.push_back(q[i]);
 338                         else
 339                         {
 340                                 if (param < p.size())
 341                                 {
 342                                         std::string parm = p[param++];
 343                                         // In the worst case, each character may need to be encoded as using two bytes,
 344                                         // and one byte is the terminating null
 345                                         std::vector<char> buffer(parm.length() * 2 + 1);
 346
 347                                         // The return value of mysql_escape_string() is the length of the encoded string,
 348                                         // not including the terminating null
 349                                         unsigned long escapedsize = mysql_escape_string(&buffer[0], parm.c_str(), parm.length());
 350 //                                      mysql_real_escape_string(connection, queryend, paramscopy[paramnum].c_str(), paramscopy[paramnum].length());
 351                                         res.append(&buffer[0], escapedsize);
 352                                 }
 353                         }
 354                 }
 355                 submit(call, res);
 356         }
 357
 358         void submit(SQLQuery* call, const std::string& q, const ParamM& p)
 359         {
 360                 std::string res;
 361                 for(std::string::size_type i = 0; i < q.length(); i++)
 362                 {
 363                         if (q[i] != '$')
 364                                 res.push_back(q[i]);
 365                         else
 366                         {
 367                                 std::string field;
 368                                 i++;
 369                                 while (i < q.length() && isalnum(q[i]))
 370                                         field.push_back(q[i++]);
 371                                 i--;
 372
 373                                 ParamM::const_iterator it = p.find(field);
 374                                 if (it != p.end())
 375                                 {
 376                                         std::string parm = it->second;
 377                                         // NOTE: See above
 378                                         std::vector<char> buffer(parm.length() * 2 + 1);
 379                                         unsigned long escapedsize = mysql_escape_string(&buffer[0], parm.c_str(), parm.length());
 380                                         res.append(&buffer[0], escapedsize);
 381                                 }
 382                         }
 383                 }
 384                 submit(call, res);
 385         }
 386 };
 387
 388 ModuleSQL::ModuleSQL()
 389 {
 390         Dispatcher = NULL;
 391 }
 392
 393 void ModuleSQL::init()
 394 {
 395         Dispatcher = new DispatcherThread(this);
 396         ServerInstance->Threads.Start(Dispatcher);
 397 }
 398
 399 ModuleSQL::~ModuleSQL()
 400 {
 401         if (Dispatcher)
 402         {
 403                 Dispatcher->join();
 404                 Dispatcher->OnNotify();
 405                 delete Dispatcher;
 406         }
 407         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 408         {
 409                 delete i->second;
 410         }
 411 }
 412
 413 void ModuleSQL::ReadConfig(ConfigStatus& status)
 414 {
 415         ConnMap conns;
 416         ConfigTagList tags = ServerInstance->Config->ConfTags("database");
 417         for(ConfigIter i = tags.first; i != tags.second; i++)
 418         {
 419                 if (i->second->getString("module", "mysql") != "mysql")
 420                         continue;
 421                 std::string id = i->second->getString("id");
 422                 ConnMap::iterator curr = connections.find(id);
 423                 if (curr == connections.end())
 424                 {
 425                         SQLConnection* conn = new SQLConnection(this, i->second);
 426                         conns.insert(std::make_pair(id, conn));
 427                         ServerInstance->Modules->AddService(*conn);
 428                 }
 429                 else
 430                 {
 431                         conns.insert(*curr);
 432                         connections.erase(curr);
 433                 }
 434         }
 435
 436         // now clean up the deleted databases
 437         Dispatcher->LockQueue();
 438         SQLerror err(SQL_BAD_DBID);
 439         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 440         {
 441                 ServerInstance->Modules->DelService(*i->second);
 442                 // it might be running a query on this database. Wait for that to complete
 443                 i->second->lock.Lock();
 444                 i->second->lock.Unlock();
 445                 // now remove all active queries to this DB
 446                 for (size_t j = qq.size(); j > 0; j--)
 447                 {
 448                         size_t k = j - 1;
 449                         if (qq[k].c == i->second)
 450                         {
 451                                 qq[k].q->OnError(err);
 452                                 delete qq[k].q;
 453                                 qq.erase(qq.begin() + k);
 454                         }
 455                 }
 456                 // finally, nuke the connection
 457                 delete i->second;
 458         }
 459         Dispatcher->UnlockQueue();
 460         connections.swap(conns);
 461 }
 462
 463 void ModuleSQL::OnUnloadModule(Module* mod)
 464 {
 465         SQLerror err(SQL_BAD_DBID);
 466         Dispatcher->LockQueue();
 467         unsigned int i = qq.size();
 468         while (i > 0)
 469         {
 470                 i--;
 471                 if (qq[i].q->creator == mod)
 472                 {
 473                         if (i == 0)
 474                         {
 475                                 // need to wait until the query is done
 476                                 // (the result will be discarded)
 477                                 qq[i].c->lock.Lock();
 478                                 qq[i].c->lock.Unlock();
 479                         }
 480                         qq[i].q->OnError(err);
 481                         delete qq[i].q;
 482                         qq.erase(qq.begin() + i);
 483                 }
 484         }
 485         Dispatcher->UnlockQueue();
 486         // clean up any result queue entries
 487         Dispatcher->OnNotify();
 488 }
 489
 490 Version ModuleSQL::GetVersion()
 491 {
 492         return Version("MySQL support", VF_VENDOR);
 493 }
 494
 495 void DispatcherThread::Run()
 496 {
 497         this->LockQueue();
 498         while (!this->GetExitFlag())
 499         {
 500                 if (!Parent->qq.empty())
 501                 {
 502                         QQueueItem i = Parent->qq.front();
 503                         i.c->lock.Lock();
 504                         this->UnlockQueue();
 505                         MySQLresult* res = i.c->DoBlockingQuery(i.query);
 506                         i.c->lock.Unlock();
 507
 508                         /*
 509                          * At this point, the main thread could be working on:
 510                          *  Rehash - delete i.c out from under us. We don't care about that.
 511                          *  UnloadModule - delete i.q and the qq item. Need to avoid reporting results.
 512                          */
 513
 514                         this->LockQueue();
 515                         if (!Parent->qq.empty() && Parent->qq.front().q == i.q)
 516                         {
 517                                 Parent->qq.pop_front();
 518                                 Parent->rq.push_back(RQueueItem(i.q, res));
 519                                 NotifyParent();
 520                         }
 521                         else
 522                         {
 523                                 // UnloadModule ate the query
 524                                 delete res;
 525                         }
 526                 }
 527                 else
 528                 {
 529                         /* We know the queue is empty, we can safely hang this thread until
 530                          * something happens
 531                          */
 532                         this->WaitForQueue();
 533                 }
 534         }
 535         this->UnlockQueue();
 536 }
 537
 538 void DispatcherThread::OnNotify()
 539 {
 540         // this could unlock during the dispatch, but OnResult isn't expected to take that long
 541         this->LockQueue();
 542         for(ResultQueue::iterator i = Parent->rq.begin(); i != Parent->rq.end(); i++)
 543         {
 544                 MySQLresult* res = i->r;
 545                 if (res->err.id == SQL_NO_ERROR)
 546                         i->q->OnResult(*res);
 547                 else
 548                         i->q->OnError(res->err);
 549                 delete i->q;
 550                 delete i->r;
 551         }
 552         Parent->rq.clear();
 553         this->UnlockQueue();
 554 }
 555
 556 MODULE_INIT(ModuleSQL)