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