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 he 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         SQLQuery* q;
  88         std::string query;
  89         SQLConnection* c;
  90         QQueueItem(SQLQuery* Q, const std::string& S, SQLConnection* C) : q(Q), query(S), c(C) {}
  91 };
  92
  93 struct RQueueItem
  94 {
  95         SQLQuery* q;
  96         MySQLresult* r;
  97         RQueueItem(SQLQuery* 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 SQLResult
 140 {
 141  public:
 142         SQLerror err;
 143         int currentrow;
 144         int rows;
 145         std::vector<std::string> colnames;
 146         std::vector<SQLEntries> fieldlists;
 147
 148         MySQLresult(MYSQL_RES* res, int affected_rows) : err(SQL_NO_ERROR), 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(SQLEntry(row[field_count]));
 178                                                 else
 179                                                         fieldlists[n].push_back(SQLEntry());
 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(SQLerror& 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         SQLEntry GetValue(int row, int column)
 207         {
 208                 if ((row >= 0) && (row < rows) && (column >= 0) && (column < (int)fieldlists[row].size()))
 209                 {
 210                         return fieldlists[row][column];
 211                 }
 212                 return SQLEntry();
 213         }
 214
 215         bool GetRow(SQLEntries& result) CXX11_OVERRIDE
 216         {
 217                 if (currentrow < rows)
 218                 {
 219                         result.assign(fieldlists[currentrow].begin(), fieldlists[currentrow].end());
 220                         currentrow++;
 221                         return true;
 222                 }
 223                 else
 224                 {
 225                         result.clear();
 226                         return false;
 227                 }
 228         }
 229 };
 230
 231 /** Represents a connection to a mysql database
 232  */
 233 class SQLConnection : public SQLProvider
 234 {
 235  public:
 236         reference<ConfigTag> config;
 237         MYSQL *connection;
 238         Mutex lock;
 239
 240         // This constructor creates an SQLConnection object with the given credentials, but does not connect yet.
 241         SQLConnection(Module* p, ConfigTag* tag) : SQLProvider(p, "SQL/" + tag->getString("id")),
 242                 config(tag), connection(NULL)
 243         {
 244         }
 245
 246         ~SQLConnection()
 247         {
 248                 Close();
 249         }
 250
 251         // This method connects to the database using the credentials supplied to the constructor, and returns
 252         // true upon success.
 253         bool Connect()
 254         {
 255                 unsigned int timeout = 1;
 256                 connection = mysql_init(connection);
 257                 mysql_options(connection,MYSQL_OPT_CONNECT_TIMEOUT,(char*)&timeout);
 258                 std::string host = config->getString("host");
 259                 std::string user = config->getString("user");
 260                 std::string pass = config->getString("pass");
 261                 std::string dbname = config->getString("name");
 262                 int port = config->getInt("port");
 263                 bool rv = mysql_real_connect(connection, host.c_str(), user.c_str(), pass.c_str(), dbname.c_str(), port, NULL, 0);
 264                 if (!rv)
 265                         return rv;
 266
 267                 // Enable character set settings
 268                 std::string charset = config->getString("charset");
 269                 if ((!charset.empty()) && (mysql_set_character_set(connection, charset.c_str())))
 270                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "WARNING: Could not set character set to \"%s\"", charset.c_str());
 271
 272                 std::string initquery;
 273                 if (config->readString("initialquery", initquery))
 274                 {
 275                         mysql_query(connection,initquery.c_str());
 276                 }
 277                 return true;
 278         }
 279
 280         ModuleSQL* Parent()
 281         {
 282                 return (ModuleSQL*)(Module*)creator;
 283         }
 284
 285         MySQLresult* DoBlockingQuery(const std::string& query)
 286         {
 287
 288                 /* Parse the command string and dispatch it to mysql */
 289                 if (CheckConnection() && !mysql_real_query(connection, query.data(), query.length()))
 290                 {
 291                         /* Successfull query */
 292                         MYSQL_RES* res = mysql_use_result(connection);
 293                         unsigned long rows = mysql_affected_rows(connection);
 294                         return new MySQLresult(res, rows);
 295                 }
 296                 else
 297                 {
 298                         /* XXX: See /usr/include/mysql/mysqld_error.h for a list of
 299                          * possible error numbers and error messages */
 300                         SQLerror e(SQL_QREPLY_FAIL, ConvToStr(mysql_errno(connection)) + ": " + mysql_error(connection));
 301                         return new MySQLresult(e);
 302                 }
 303         }
 304
 305         bool CheckConnection()
 306         {
 307                 if (!connection || mysql_ping(connection) != 0)
 308                         return Connect();
 309                 return true;
 310         }
 311
 312         std::string GetError()
 313         {
 314                 return mysql_error(connection);
 315         }
 316
 317         void Close()
 318         {
 319                 mysql_close(connection);
 320         }
 321
 322         void submit(SQLQuery* q, const std::string& qs) CXX11_OVERRIDE
 323         {
 324                 Parent()->Dispatcher->LockQueue();
 325                 Parent()->qq.push_back(QQueueItem(q, qs, this));
 326                 Parent()->Dispatcher->UnlockQueueWakeup();
 327         }
 328
 329         void submit(SQLQuery* call, const std::string& q, const ParamL& p) CXX11_OVERRIDE
 330         {
 331                 std::string res;
 332                 unsigned int param = 0;
 333                 for(std::string::size_type i = 0; i < q.length(); i++)
 334                 {
 335                         if (q[i] != '?')
 336                                 res.push_back(q[i]);
 337                         else
 338                         {
 339                                 if (param < p.size())
 340                                 {
 341                                         std::string parm = p[param++];
 342                                         // In the worst case, each character may need to be encoded as using two bytes,
 343                                         // and one byte is the terminating null
 344                                         std::vector<char> buffer(parm.length() * 2 + 1);
 345
 346                                         // The return value of mysql_escape_string() is the length of the encoded string,
 347                                         // not including the terminating null
 348                                         unsigned long escapedsize = mysql_escape_string(&buffer[0], parm.c_str(), parm.length());
 349 //                                      mysql_real_escape_string(connection, queryend, paramscopy[paramnum].c_str(), paramscopy[paramnum].length());
 350                                         res.append(&buffer[0], escapedsize);
 351                                 }
 352                         }
 353                 }
 354                 submit(call, res);
 355         }
 356
 357         void submit(SQLQuery* call, const std::string& q, const ParamM& p) CXX11_OVERRIDE
 358         {
 359                 std::string res;
 360                 for(std::string::size_type i = 0; i < q.length(); i++)
 361                 {
 362                         if (q[i] != '$')
 363                                 res.push_back(q[i]);
 364                         else
 365                         {
 366                                 std::string field;
 367                                 i++;
 368                                 while (i < q.length() && isalnum(q[i]))
 369                                         field.push_back(q[i++]);
 370                                 i--;
 371
 372                                 ParamM::const_iterator it = p.find(field);
 373                                 if (it != p.end())
 374                                 {
 375                                         std::string parm = it->second;
 376                                         // NOTE: See above
 377                                         std::vector<char> buffer(parm.length() * 2 + 1);
 378                                         unsigned long escapedsize = mysql_escape_string(&buffer[0], parm.c_str(), parm.length());
 379                                         res.append(&buffer[0], escapedsize);
 380                                 }
 381                         }
 382                 }
 383                 submit(call, res);
 384         }
 385 };
 386
 387 ModuleSQL::ModuleSQL()
 388 {
 389         Dispatcher = NULL;
 390 }
 391
 392 void ModuleSQL::init()
 393 {
 394         Dispatcher = new DispatcherThread(this);
 395         ServerInstance->Threads.Start(Dispatcher);
 396 }
 397
 398 ModuleSQL::~ModuleSQL()
 399 {
 400         if (Dispatcher)
 401         {
 402                 Dispatcher->join();
 403                 Dispatcher->OnNotify();
 404                 delete Dispatcher;
 405         }
 406         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 407         {
 408                 delete i->second;
 409         }
 410 }
 411
 412 void ModuleSQL::ReadConfig(ConfigStatus& status)
 413 {
 414         ConnMap conns;
 415         ConfigTagList tags = ServerInstance->Config->ConfTags("database");
 416         for(ConfigIter i = tags.first; i != tags.second; i++)
 417         {
 418                 if (i->second->getString("module", "mysql") != "mysql")
 419                         continue;
 420                 std::string id = i->second->getString("id");
 421                 ConnMap::iterator curr = connections.find(id);
 422                 if (curr == connections.end())
 423                 {
 424                         SQLConnection* conn = new SQLConnection(this, i->second);
 425                         conns.insert(std::make_pair(id, conn));
 426                         ServerInstance->Modules->AddService(*conn);
 427                 }
 428                 else
 429                 {
 430                         conns.insert(*curr);
 431                         connections.erase(curr);
 432                 }
 433         }
 434
 435         // now clean up the deleted databases
 436         Dispatcher->LockQueue();
 437         SQLerror err(SQL_BAD_DBID);
 438         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 439         {
 440                 ServerInstance->Modules->DelService(*i->second);
 441                 // it might be running a query on this database. Wait for that to complete
 442                 i->second->lock.Lock();
 443                 i->second->lock.Unlock();
 444                 // now remove all active queries to this DB
 445                 for (size_t j = qq.size(); j > 0; j--)
 446                 {
 447                         size_t k = j - 1;
 448                         if (qq[k].c == i->second)
 449                         {
 450                                 qq[k].q->OnError(err);
 451                                 delete qq[k].q;
 452                                 qq.erase(qq.begin() + k);
 453                         }
 454                 }
 455                 // finally, nuke the connection
 456                 delete i->second;
 457         }
 458         Dispatcher->UnlockQueue();
 459         connections.swap(conns);
 460 }
 461
 462 void ModuleSQL::OnUnloadModule(Module* mod)
 463 {
 464         SQLerror err(SQL_BAD_DBID);
 465         Dispatcher->LockQueue();
 466         unsigned int i = qq.size();
 467         while (i > 0)
 468         {
 469                 i--;
 470                 if (qq[i].q->creator == mod)
 471                 {
 472                         if (i == 0)
 473                         {
 474                                 // need to wait until the query is done
 475                                 // (the result will be discarded)
 476                                 qq[i].c->lock.Lock();
 477                                 qq[i].c->lock.Unlock();
 478                         }
 479                         qq[i].q->OnError(err);
 480                         delete qq[i].q;
 481                         qq.erase(qq.begin() + i);
 482                 }
 483         }
 484         Dispatcher->UnlockQueue();
 485         // clean up any result queue entries
 486         Dispatcher->OnNotify();
 487 }
 488
 489 Version ModuleSQL::GetVersion()
 490 {
 491         return Version("MySQL support", VF_VENDOR);
 492 }
 493
 494 void DispatcherThread::Run()
 495 {
 496         this->LockQueue();
 497         while (!this->GetExitFlag())
 498         {
 499                 if (!Parent->qq.empty())
 500                 {
 501                         QQueueItem i = Parent->qq.front();
 502                         i.c->lock.Lock();
 503                         this->UnlockQueue();
 504                         MySQLresult* res = i.c->DoBlockingQuery(i.query);
 505                         i.c->lock.Unlock();
 506
 507                         /*
 508                          * At this point, the main thread could be working on:
 509                          *  Rehash - delete i.c out from under us. We don't care about that.
 510                          *  UnloadModule - delete i.q and the qq item. Need to avoid reporting results.
 511                          */
 512
 513                         this->LockQueue();
 514                         if (!Parent->qq.empty() && Parent->qq.front().q == i.q)
 515                         {
 516                                 Parent->qq.pop_front();
 517                                 Parent->rq.push_back(RQueueItem(i.q, res));
 518                                 NotifyParent();
 519                         }
 520                         else
 521                         {
 522                                 // UnloadModule ate the query
 523                                 delete res;
 524                         }
 525                 }
 526                 else
 527                 {
 528                         /* We know the queue is empty, we can safely hang this thread until
 529                          * something happens
 530                          */
 531                         this->WaitForQueue();
 532                 }
 533         }
 534         this->UnlockQueue();
 535 }
 536
 537 void DispatcherThread::OnNotify()
 538 {
 539         // this could unlock during the dispatch, but OnResult isn't expected to take that long
 540         this->LockQueue();
 541         for(ResultQueue::iterator i = Parent->rq.begin(); i != Parent->rq.end(); i++)
 542         {
 543                 MySQLresult* res = i->r;
 544                 if (res->err.id == SQL_NO_ERROR)
 545                         i->q->OnResult(*res);
 546                 else
 547                         i->q->OnError(res->err);
 548                 delete i->q;
 549                 delete i->r;
 550         }
 551         Parent->rq.clear();
 552         this->UnlockQueue();
 553 }
 554
 555 MODULE_INIT(ModuleSQL)