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("debian") libmysqlclient-dev
  29 /// $PackageInfo: require_system("ubuntu") libmysqlclient-dev
  30
  31 #ifdef __GNUC__
  32 # pragma GCC diagnostic push
  33 #endif
  34
  35 // Fix warnings about the use of `long long` on C++03.
  36 #if defined __clang__
  37 # pragma clang diagnostic ignored "-Wc++11-long-long"
  38 #elif defined __GNUC__
  39 # pragma GCC diagnostic ignored "-Wlong-long"
  40 #endif
  41
  42 #include "inspircd.h"
  43 #include <mysql.h>
  44 #include "modules/sql.h"
  45
  46 #ifdef __GNUC__
  47 # pragma GCC diagnostic pop
  48 #endif
  49
  50 #ifdef _WIN32
  51 # pragma comment(lib, "libmysql.lib")
  52 #endif
  53
  54 /* VERSION 3 API: With nonblocking (threaded) requests */
  55
  56 /* THE NONBLOCKING MYSQL API!
  57  *
  58  * MySQL provides no nonblocking (asyncronous) API of its own, and its developers recommend
  59  * that instead, you should thread your program. This is what i've done here to allow for
  60  * asyncronous SQL requests via mysql. The way this works is as follows:
  61  *
  62  * The module spawns a thread via class Thread, and performs its mysql queries in this thread,
  63  * using a queue with priorities. There is a mutex on either end which prevents two threads
  64  * adjusting the queue at the same time, and crashing the ircd. Every 50 milliseconds, the
  65  * worker thread wakes up, and checks if there is a request at the head of its queue.
  66  * If there is, it processes this request, blocking the worker thread but leaving the ircd
  67  * thread to go about its business as usual. During this period, the ircd thread is able
  68  * to insert futher pending requests into the queue.
  69  *
  70  * Once the processing of a request is complete, it is removed from the incoming queue to
  71  * an outgoing queue, and initialized as a 'response'. The worker thread then signals the
  72  * ircd thread (via a loopback socket) of the fact a result is available, by sending the
  73  * connection ID through the connection.
  74  *
  75  * The ircd thread then mutexes the queue once more, reads the outbound response off the head
  76  * of the queue, and sends it on its way to the original calling module.
  77  *
  78  * XXX: You might be asking "why doesnt it just send the response from within the worker thread?"
  79  * The answer to this is simple. The majority of InspIRCd, and in fact most ircd's are not
  80  * threadsafe. This module is designed to be threadsafe and is careful with its use of threads,
  81  * however, if we were to call a module's OnRequest even from within a thread which was not the
  82  * one the module was originally instantiated upon, there is a chance of all hell breaking loose
  83  * if a module is ever put in a re-enterant state (stack corruption could occur, crashes, data
  84  * corruption, and worse, so DONT think about it until the day comes when InspIRCd is 100%
  85  * gauranteed threadsafe!)
  86  */
  87
  88 class SQLConnection;
  89 class MySQLresult;
  90 class DispatcherThread;
  91
  92 struct QQueueItem
  93 {
  94         SQL::Query* q;
  95         std::string query;
  96         SQLConnection* c;
  97         QQueueItem(SQL::Query* Q, const std::string& S, SQLConnection* C) : q(Q), query(S), c(C) {}
  98 };
  99
 100 struct RQueueItem
 101 {
 102         SQL::Query* q;
 103         MySQLresult* r;
 104         RQueueItem(SQL::Query* Q, MySQLresult* R) : q(Q), r(R) {}
 105 };
 106
 107 typedef insp::flat_map<std::string, SQLConnection*> ConnMap;
 108 typedef std::deque<QQueueItem> QueryQueue;
 109 typedef std::deque<RQueueItem> ResultQueue;
 110
 111 /** MySQL module
 112  *  */
 113 class ModuleSQL : public Module
 114 {
 115  public:
 116         DispatcherThread* Dispatcher;
 117         QueryQueue qq;       // MUST HOLD MUTEX
 118         ResultQueue rq;      // MUST HOLD MUTEX
 119         ConnMap connections; // main thread only
 120
 121         ModuleSQL();
 122         void init() CXX11_OVERRIDE;
 123         ~ModuleSQL();
 124         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE;
 125         void OnUnloadModule(Module* mod) CXX11_OVERRIDE;
 126         Version GetVersion() CXX11_OVERRIDE;
 127 };
 128
 129 class DispatcherThread : public SocketThread
 130 {
 131  private:
 132         ModuleSQL* const Parent;
 133  public:
 134         DispatcherThread(ModuleSQL* CreatorModule) : Parent(CreatorModule) { }
 135         ~DispatcherThread() { }
 136         void Run() CXX11_OVERRIDE;
 137         void OnNotify() CXX11_OVERRIDE;
 138 };
 139
 140 #if !defined(MYSQL_VERSION_ID) || MYSQL_VERSION_ID<32224
 141 #define mysql_field_count mysql_num_fields
 142 #endif
 143
 144 /** Represents a mysql result set
 145  */
 146 class MySQLresult : public SQL::Result
 147 {
 148  public:
 149         SQL::Error err;
 150         int currentrow;
 151         int rows;
 152         std::vector<std::string> colnames;
 153         std::vector<SQL::Row> fieldlists;
 154
 155         MySQLresult(MYSQL_RES* res, int affected_rows) : err(SQL::SUCCESS), currentrow(0), rows(0)
 156         {
 157                 if (affected_rows >= 1)
 158                 {
 159                         rows = affected_rows;
 160                         fieldlists.resize(rows);
 161                 }
 162                 unsigned int field_count = 0;
 163                 if (res)
 164                 {
 165                         MYSQL_ROW row;
 166                         int n = 0;
 167                         while ((row = mysql_fetch_row(res)))
 168                         {
 169                                 if (fieldlists.size() < (unsigned int)rows+1)
 170                                 {
 171                                         fieldlists.resize(fieldlists.size()+1);
 172                                 }
 173                                 field_count = 0;
 174                                 MYSQL_FIELD *fields = mysql_fetch_fields(res);
 175                                 if(mysql_num_fields(res) == 0)
 176                                         break;
 177                                 if (fields && mysql_num_fields(res))
 178                                 {
 179                                         colnames.clear();
 180                                         while (field_count < mysql_num_fields(res))
 181                                         {
 182                                                 std::string a = (fields[field_count].name ? fields[field_count].name : "");
 183                                                 if (row[field_count])
 184                                                         fieldlists[n].push_back(SQL::Field(row[field_count]));
 185                                                 else
 186                                                         fieldlists[n].push_back(SQL::Field());
 187                                                 colnames.push_back(a);
 188                                                 field_count++;
 189                                         }
 190                                         n++;
 191                                 }
 192                                 rows++;
 193                         }
 194                         mysql_free_result(res);
 195                 }
 196         }
 197
 198         MySQLresult(SQL::Error& e) : err(e)
 199         {
 200
 201         }
 202
 203         int Rows() CXX11_OVERRIDE
 204         {
 205                 return rows;
 206         }
 207
 208         void GetCols(std::vector<std::string>& result) CXX11_OVERRIDE
 209         {
 210                 result.assign(colnames.begin(), colnames.end());
 211         }
 212
 213         bool HasColumn(const std::string& column, size_t& index) CXX11_OVERRIDE
 214         {
 215                 for (size_t i = 0; i < colnames.size(); ++i)
 216                 {
 217                         if (colnames[i] == column)
 218                         {
 219                                 index = i;
 220                                 return true;
 221                         }
 222                 }
 223                 return false;
 224         }
 225
 226         SQL::Field GetValue(int row, int column)
 227         {
 228                 if ((row >= 0) && (row < rows) && (column >= 0) && (column < (int)fieldlists[row].size()))
 229                 {
 230                         return fieldlists[row][column];
 231                 }
 232                 return SQL::Field();
 233         }
 234
 235         bool GetRow(SQL::Row& result) CXX11_OVERRIDE
 236         {
 237                 if (currentrow < rows)
 238                 {
 239                         result.assign(fieldlists[currentrow].begin(), fieldlists[currentrow].end());
 240                         currentrow++;
 241                         return true;
 242                 }
 243                 else
 244                 {
 245                         result.clear();
 246                         return false;
 247                 }
 248         }
 249 };
 250
 251 /** Represents a connection to a mysql database
 252  */
 253 class SQLConnection : public SQL::Provider
 254 {
 255  public:
 256         reference<ConfigTag> config;
 257         MYSQL *connection;
 258         Mutex lock;
 259
 260         // This constructor creates an SQLConnection object with the given credentials, but does not connect yet.
 261         SQLConnection(Module* p, ConfigTag* tag) : SQL::Provider(p, "SQL/" + tag->getString("id")),
 262                 config(tag), connection(NULL)
 263         {
 264         }
 265
 266         ~SQLConnection()
 267         {
 268                 Close();
 269         }
 270
 271         // This method connects to the database using the credentials supplied to the constructor, and returns
 272         // true upon success.
 273         bool Connect()
 274         {
 275                 unsigned int timeout = 1;
 276                 connection = mysql_init(connection);
 277                 mysql_options(connection,MYSQL_OPT_CONNECT_TIMEOUT,(char*)&timeout);
 278                 std::string host = config->getString("host");
 279                 std::string user = config->getString("user");
 280                 std::string pass = config->getString("pass");
 281                 std::string dbname = config->getString("name");
 282                 unsigned int port = config->getUInt("port", 3306);
 283                 bool rv = mysql_real_connect(connection, host.c_str(), user.c_str(), pass.c_str(), dbname.c_str(), port, NULL, 0);
 284                 if (!rv)
 285                         return rv;
 286
 287                 // Enable character set settings
 288                 std::string charset = config->getString("charset");
 289                 if ((!charset.empty()) && (mysql_set_character_set(connection, charset.c_str())))
 290                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "WARNING: Could not set character set to \"%s\"", charset.c_str());
 291
 292                 std::string initquery;
 293                 if (config->readString("initialquery", initquery))
 294                 {
 295                         mysql_query(connection,initquery.c_str());
 296                 }
 297                 return true;
 298         }
 299
 300         ModuleSQL* Parent()
 301         {
 302                 return (ModuleSQL*)(Module*)creator;
 303         }
 304
 305         MySQLresult* DoBlockingQuery(const std::string& query)
 306         {
 307
 308                 /* Parse the command string and dispatch it to mysql */
 309                 if (CheckConnection() && !mysql_real_query(connection, query.data(), query.length()))
 310                 {
 311                         /* Successfull query */
 312                         MYSQL_RES* res = mysql_use_result(connection);
 313                         unsigned long rows = mysql_affected_rows(connection);
 314                         return new MySQLresult(res, rows);
 315                 }
 316                 else
 317                 {
 318                         /* XXX: See /usr/include/mysql/mysqld_error.h for a list of
 319                          * possible error numbers and error messages */
 320                         SQL::Error e(SQL::QREPLY_FAIL, InspIRCd::Format("%u: %s", mysql_errno(connection), mysql_error(connection)));
 321                         return new MySQLresult(e);
 322                 }
 323         }
 324
 325         bool CheckConnection()
 326         {
 327                 if (!connection || mysql_ping(connection) != 0)
 328                         return Connect();
 329                 return true;
 330         }
 331
 332         std::string GetError()
 333         {
 334                 return mysql_error(connection);
 335         }
 336
 337         void Close()
 338         {
 339                 mysql_close(connection);
 340         }
 341
 342         void Submit(SQL::Query* q, const std::string& qs) CXX11_OVERRIDE
 343         {
 344                 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Executing MySQL query: " + qs);
 345                 Parent()->Dispatcher->LockQueue();
 346                 Parent()->qq.push_back(QQueueItem(q, qs, this));
 347                 Parent()->Dispatcher->UnlockQueueWakeup();
 348         }
 349
 350         void Submit(SQL::Query* call, const std::string& q, const SQL::ParamList& p) CXX11_OVERRIDE
 351         {
 352                 std::string res;
 353                 unsigned int param = 0;
 354                 for(std::string::size_type i = 0; i < q.length(); i++)
 355                 {
 356                         if (q[i] != '?')
 357                                 res.push_back(q[i]);
 358                         else
 359                         {
 360                                 if (param < p.size())
 361                                 {
 362                                         std::string parm = p[param++];
 363                                         // In the worst case, each character may need to be encoded as using two bytes,
 364                                         // and one byte is the terminating null
 365                                         std::vector<char> buffer(parm.length() * 2 + 1);
 366
 367                                         // The return value of mysql_real_escape_string() is the length of the encoded string,
 368                                         // not including the terminating null
 369                                         unsigned long escapedsize = mysql_real_escape_string(connection, &buffer[0], parm.c_str(), parm.length());
 370                                         res.append(&buffer[0], escapedsize);
 371                                 }
 372                         }
 373                 }
 374                 Submit(call, res);
 375         }
 376
 377         void Submit(SQL::Query* call, const std::string& q, const SQL::ParamMap& p) CXX11_OVERRIDE
 378         {
 379                 std::string res;
 380                 for(std::string::size_type i = 0; i < q.length(); i++)
 381                 {
 382                         if (q[i] != '$')
 383                                 res.push_back(q[i]);
 384                         else
 385                         {
 386                                 std::string field;
 387                                 i++;
 388                                 while (i < q.length() && isalnum(q[i]))
 389                                         field.push_back(q[i++]);
 390                                 i--;
 391
 392                                 SQL::ParamMap::const_iterator it = p.find(field);
 393                                 if (it != p.end())
 394                                 {
 395                                         std::string parm = it->second;
 396                                         // NOTE: See above
 397                                         std::vector<char> buffer(parm.length() * 2 + 1);
 398                                         unsigned long escapedsize = mysql_escape_string(&buffer[0], parm.c_str(), parm.length());
 399                                         res.append(&buffer[0], escapedsize);
 400                                 }
 401                         }
 402                 }
 403                 Submit(call, res);
 404         }
 405 };
 406
 407 ModuleSQL::ModuleSQL()
 408 {
 409         Dispatcher = NULL;
 410 }
 411
 412 void ModuleSQL::init()
 413 {
 414         Dispatcher = new DispatcherThread(this);
 415         ServerInstance->Threads.Start(Dispatcher);
 416 }
 417
 418 ModuleSQL::~ModuleSQL()
 419 {
 420         if (Dispatcher)
 421         {
 422                 Dispatcher->join();
 423                 Dispatcher->OnNotify();
 424                 delete Dispatcher;
 425         }
 426         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 427         {
 428                 delete i->second;
 429         }
 430 }
 431
 432 void ModuleSQL::ReadConfig(ConfigStatus& status)
 433 {
 434         ConnMap conns;
 435         ConfigTagList tags = ServerInstance->Config->ConfTags("database");
 436         for(ConfigIter i = tags.first; i != tags.second; i++)
 437         {
 438                 if (!stdalgo::string::equalsci(i->second->getString("module"), "mysql"))
 439                         continue;
 440                 std::string id = i->second->getString("id");
 441                 ConnMap::iterator curr = connections.find(id);
 442                 if (curr == connections.end())
 443                 {
 444                         SQLConnection* conn = new SQLConnection(this, i->second);
 445                         conns.insert(std::make_pair(id, conn));
 446                         ServerInstance->Modules->AddService(*conn);
 447                 }
 448                 else
 449                 {
 450                         conns.insert(*curr);
 451                         connections.erase(curr);
 452                 }
 453         }
 454
 455         // now clean up the deleted databases
 456         Dispatcher->LockQueue();
 457         SQL::Error err(SQL::BAD_DBID);
 458         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 459         {
 460                 ServerInstance->Modules->DelService(*i->second);
 461                 // it might be running a query on this database. Wait for that to complete
 462                 i->second->lock.Lock();
 463                 i->second->lock.Unlock();
 464                 // now remove all active queries to this DB
 465                 for (size_t j = qq.size(); j > 0; j--)
 466                 {
 467                         size_t k = j - 1;
 468                         if (qq[k].c == i->second)
 469                         {
 470                                 qq[k].q->OnError(err);
 471                                 delete qq[k].q;
 472                                 qq.erase(qq.begin() + k);
 473                         }
 474                 }
 475                 // finally, nuke the connection
 476                 delete i->second;
 477         }
 478         Dispatcher->UnlockQueue();
 479         connections.swap(conns);
 480 }
 481
 482 void ModuleSQL::OnUnloadModule(Module* mod)
 483 {
 484         SQL::Error err(SQL::BAD_DBID);
 485         Dispatcher->LockQueue();
 486         unsigned int i = qq.size();
 487         while (i > 0)
 488         {
 489                 i--;
 490                 if (qq[i].q->creator == mod)
 491                 {
 492                         if (i == 0)
 493                         {
 494                                 // need to wait until the query is done
 495                                 // (the result will be discarded)
 496                                 qq[i].c->lock.Lock();
 497                                 qq[i].c->lock.Unlock();
 498                         }
 499                         qq[i].q->OnError(err);
 500                         delete qq[i].q;
 501                         qq.erase(qq.begin() + i);
 502                 }
 503         }
 504         Dispatcher->UnlockQueue();
 505         // clean up any result queue entries
 506         Dispatcher->OnNotify();
 507 }
 508
 509 Version ModuleSQL::GetVersion()
 510 {
 511         return Version("Provides MySQL support", VF_VENDOR);
 512 }
 513
 514 void DispatcherThread::Run()
 515 {
 516         this->LockQueue();
 517         while (!this->GetExitFlag())
 518         {
 519                 if (!Parent->qq.empty())
 520                 {
 521                         QQueueItem i = Parent->qq.front();
 522                         i.c->lock.Lock();
 523                         this->UnlockQueue();
 524                         MySQLresult* res = i.c->DoBlockingQuery(i.query);
 525                         i.c->lock.Unlock();
 526
 527                         /*
 528                          * At this point, the main thread could be working on:
 529                          *  Rehash - delete i.c out from under us. We don't care about that.
 530                          *  UnloadModule - delete i.q and the qq item. Need to avoid reporting results.
 531                          */
 532
 533                         this->LockQueue();
 534                         if (!Parent->qq.empty() && Parent->qq.front().q == i.q)
 535                         {
 536                                 Parent->qq.pop_front();
 537                                 Parent->rq.push_back(RQueueItem(i.q, res));
 538                                 NotifyParent();
 539                         }
 540                         else
 541                         {
 542                                 // UnloadModule ate the query
 543                                 delete res;
 544                         }
 545                 }
 546                 else
 547                 {
 548                         /* We know the queue is empty, we can safely hang this thread until
 549                          * something happens
 550                          */
 551                         this->WaitForQueue();
 552                 }
 553         }
 554         this->UnlockQueue();
 555 }
 556
 557 void DispatcherThread::OnNotify()
 558 {
 559         // this could unlock during the dispatch, but OnResult isn't expected to take that long
 560         this->LockQueue();
 561         for(ResultQueue::iterator i = Parent->rq.begin(); i != Parent->rq.end(); i++)
 562         {
 563                 MySQLresult* res = i->r;
 564                 if (res->err.code == SQL::SUCCESS)
 565                         i->q->OnResult(*res);
 566                 else
 567                         i->q->OnError(res->err);
 568                 delete i->q;
 569                 delete i->r;
 570         }
 571         Parent->rq.clear();
 572         this->UnlockQueue();
 573 }
 574
 575 MODULE_INIT(ModuleSQL)