src/modules/extra/m_mysql.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
   5  *   Copyright (C) 2006-2007, 2009 Dennis Friis <peavey@inspircd.org>
   6  *   Copyright (C) 2006-2009 Craig Edwards <craigedwards@brainbox.cc>
   7  *   Copyright (C) 2008 Robin Burchell <robin+git@viroteck.net>
   8  *
   9  * This file is part of InspIRCd.  InspIRCd is free software: you can
  10  * redistribute it and/or modify it under the terms of the GNU General Public
  11  * License as published by the Free Software Foundation, version 2.
  12  *
  13  * This program is distributed in the hope that it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  15  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22
  23 /* Stop mysql wanting to use long long */
  24 #define NO_CLIENT_LONG_LONG
  25
  26 #include "inspircd.h"
  27 #include <mysql.h>
  28 #include "modules/sql.h"
  29
  30 #ifdef _WIN32
  31 # pragma comment(lib, "libmysql.lib")
  32 #endif
  33
  34 /* VERSION 3 API: With nonblocking (threaded) requests */
  35
  36 /* $CompileFlags: exec("mysql_config --include") */
  37 /* $LinkerFlags: exec("mysql_config --libs_r") rpath("mysql_config --libs_r") */
  38
  39 /* THE NONBLOCKING MYSQL API!
  40  *
  41  * MySQL provides no nonblocking (asyncronous) API of its own, and its developers recommend
  42  * that instead, you should thread your program. This is what i've done here to allow for
  43  * asyncronous SQL requests via mysql. The way this works is as follows:
  44  *
  45  * The module spawns a thread via class Thread, and performs its mysql queries in this thread,
  46  * using a queue with priorities. There is a mutex on either end which prevents two threads
  47  * adjusting the queue at the same time, and crashing the ircd. Every 50 milliseconds, the
  48  * worker thread wakes up, and checks if there is a request at the head of its queue.
  49  * If there is, it processes this request, blocking the worker thread but leaving the ircd
  50  * thread to go about its business as usual. During this period, the ircd thread is able
  51  * to insert futher pending requests into the queue.
  52  *
  53  * Once the processing of a request is complete, it is removed from the incoming queue to
  54  * an outgoing queue, and initialized as a 'response'. The worker thread then signals the
  55  * ircd thread (via a loopback socket) of the fact a result is available, by sending the
  56  * connection ID through the connection.
  57  *
  58  * The ircd thread then mutexes the queue once more, reads the outbound response off the head
  59  * of the queue, and sends it on its way to the original calling module.
  60  *
  61  * XXX: You might be asking "why doesnt he just send the response from within the worker thread?"
  62  * The answer to this is simple. The majority of InspIRCd, and in fact most ircd's are not
  63  * threadsafe. This module is designed to be threadsafe and is careful with its use of threads,
  64  * however, if we were to call a module's OnRequest even from within a thread which was not the
  65  * one the module was originally instantiated upon, there is a chance of all hell breaking loose
  66  * if a module is ever put in a re-enterant state (stack corruption could occur, crashes, data
  67  * corruption, and worse, so DONT think about it until the day comes when InspIRCd is 100%
  68  * gauranteed threadsafe!)
  69  *
  70  * For a diagram of this system please see http://wiki.inspircd.org/Mysql2
  71  */
  72
  73 class SQLConnection;
  74 class MySQLresult;
  75 class DispatcherThread;
  76
  77 struct QQueueItem
  78 {
  79         SQLQuery* q;
  80         std::string query;
  81         SQLConnection* c;
  82         QQueueItem(SQLQuery* Q, const std::string& S, SQLConnection* C) : q(Q), query(S), c(C) {}
  83 };
  84
  85 struct RQueueItem
  86 {
  87         SQLQuery* q;
  88         MySQLresult* r;
  89         RQueueItem(SQLQuery* Q, MySQLresult* R) : q(Q), r(R) {}
  90 };
  91
  92 typedef insp::flat_map<std::string, SQLConnection*> ConnMap;
  93 typedef std::deque<QQueueItem> QueryQueue;
  94 typedef std::deque<RQueueItem> ResultQueue;
  95
  96 /** MySQL module
  97  *  */
  98 class ModuleSQL : public Module
  99 {
 100  public:
 101         DispatcherThread* Dispatcher;
 102         QueryQueue qq;       // MUST HOLD MUTEX
 103         ResultQueue rq;      // MUST HOLD MUTEX
 104         ConnMap connections; // main thread only
 105
 106         ModuleSQL();
 107         void init() CXX11_OVERRIDE;
 108         ~ModuleSQL();
 109         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE;
 110         void OnUnloadModule(Module* mod) CXX11_OVERRIDE;
 111         Version GetVersion() CXX11_OVERRIDE;
 112 };
 113
 114 class DispatcherThread : public SocketThread
 115 {
 116  private:
 117         ModuleSQL* const Parent;
 118  public:
 119         DispatcherThread(ModuleSQL* CreatorModule) : Parent(CreatorModule) { }
 120         ~DispatcherThread() { }
 121         void Run();
 122         void OnNotify();
 123 };
 124
 125 #if !defined(MYSQL_VERSION_ID) || MYSQL_VERSION_ID<32224
 126 #define mysql_field_count mysql_num_fields
 127 #endif
 128
 129 /** Represents a mysql result set
 130  */
 131 class MySQLresult : public SQLResult
 132 {
 133  public:
 134         SQLerror err;
 135         int currentrow;
 136         int rows;
 137         std::vector<std::string> colnames;
 138         std::vector<SQLEntries> fieldlists;
 139
 140         MySQLresult(MYSQL_RES* res, int affected_rows) : err(SQL_NO_ERROR), currentrow(0), rows(0)
 141         {
 142                 if (affected_rows >= 1)
 143                 {
 144                         rows = affected_rows;
 145                         fieldlists.resize(rows);
 146                 }
 147                 unsigned int field_count = 0;
 148                 if (res)
 149                 {
 150                         MYSQL_ROW row;
 151                         int n = 0;
 152                         while ((row = mysql_fetch_row(res)))
 153                         {
 154                                 if (fieldlists.size() < (unsigned int)rows+1)
 155                                 {
 156                                         fieldlists.resize(fieldlists.size()+1);
 157                                 }
 158                                 field_count = 0;
 159                                 MYSQL_FIELD *fields = mysql_fetch_fields(res);
 160                                 if(mysql_num_fields(res) == 0)
 161                                         break;
 162                                 if (fields && mysql_num_fields(res))
 163                                 {
 164                                         colnames.clear();
 165                                         while (field_count < mysql_num_fields(res))
 166                                         {
 167                                                 std::string a = (fields[field_count].name ? fields[field_count].name : "");
 168                                                 if (row[field_count])
 169                                                         fieldlists[n].push_back(SQLEntry(row[field_count]));
 170                                                 else
 171                                                         fieldlists[n].push_back(SQLEntry());
 172                                                 colnames.push_back(a);
 173                                                 field_count++;
 174                                         }
 175                                         n++;
 176                                 }
 177                                 rows++;
 178                         }
 179                         mysql_free_result(res);
 180                 }
 181         }
 182
 183         MySQLresult(SQLerror& e) : err(e)
 184         {
 185
 186         }
 187
 188         int Rows()
 189         {
 190                 return rows;
 191         }
 192
 193         void GetCols(std::vector<std::string>& result)
 194         {
 195                 result.assign(colnames.begin(), colnames.end());
 196         }
 197
 198         SQLEntry GetValue(int row, int column)
 199         {
 200                 if ((row >= 0) && (row < rows) && (column >= 0) && (column < (int)fieldlists[row].size()))
 201                 {
 202                         return fieldlists[row][column];
 203                 }
 204                 return SQLEntry();
 205         }
 206
 207         bool GetRow(SQLEntries& result)
 208         {
 209                 if (currentrow < rows)
 210                 {
 211                         result.assign(fieldlists[currentrow].begin(), fieldlists[currentrow].end());
 212                         currentrow++;
 213                         return true;
 214                 }
 215                 else
 216                 {
 217                         result.clear();
 218                         return false;
 219                 }
 220         }
 221 };
 222
 223 /** Represents a connection to a mysql database
 224  */
 225 class SQLConnection : public SQLProvider
 226 {
 227  public:
 228         reference<ConfigTag> config;
 229         MYSQL *connection;
 230         Mutex lock;
 231
 232         // This constructor creates an SQLConnection object with the given credentials, but does not connect yet.
 233         SQLConnection(Module* p, ConfigTag* tag) : SQLProvider(p, "SQL/" + tag->getString("id")),
 234                 config(tag), connection(NULL)
 235         {
 236         }
 237
 238         ~SQLConnection()
 239         {
 240                 Close();
 241         }
 242
 243         // This method connects to the database using the credentials supplied to the constructor, and returns
 244         // true upon success.
 245         bool Connect()
 246         {
 247                 unsigned int timeout = 1;
 248                 connection = mysql_init(connection);
 249                 mysql_options(connection,MYSQL_OPT_CONNECT_TIMEOUT,(char*)&timeout);
 250                 std::string host = config->getString("host");
 251                 std::string user = config->getString("user");
 252                 std::string pass = config->getString("pass");
 253                 std::string dbname = config->getString("name");
 254                 int port = config->getInt("port");
 255                 bool rv = mysql_real_connect(connection, host.c_str(), user.c_str(), pass.c_str(), dbname.c_str(), port, NULL, 0);
 256                 if (!rv)
 257                         return rv;
 258                 std::string initquery;
 259                 if (config->readString("initialquery", initquery))
 260                 {
 261                         mysql_query(connection,initquery.c_str());
 262                 }
 263                 return true;
 264         }
 265
 266         ModuleSQL* Parent()
 267         {
 268                 return (ModuleSQL*)(Module*)creator;
 269         }
 270
 271         MySQLresult* DoBlockingQuery(const std::string& query)
 272         {
 273
 274                 /* Parse the command string and dispatch it to mysql */
 275                 if (CheckConnection() && !mysql_real_query(connection, query.data(), query.length()))
 276                 {
 277                         /* Successfull query */
 278                         MYSQL_RES* res = mysql_use_result(connection);
 279                         unsigned long rows = mysql_affected_rows(connection);
 280                         return new MySQLresult(res, rows);
 281                 }
 282                 else
 283                 {
 284                         /* XXX: See /usr/include/mysql/mysqld_error.h for a list of
 285                          * possible error numbers and error messages */
 286                         SQLerror e(SQL_QREPLY_FAIL, ConvToStr(mysql_errno(connection)) + ": " + mysql_error(connection));
 287                         return new MySQLresult(e);
 288                 }
 289         }
 290
 291         bool CheckConnection()
 292         {
 293                 if (!connection || mysql_ping(connection) != 0)
 294                         return Connect();
 295                 return true;
 296         }
 297
 298         std::string GetError()
 299         {
 300                 return mysql_error(connection);
 301         }
 302
 303         void Close()
 304         {
 305                 mysql_close(connection);
 306         }
 307
 308         void submit(SQLQuery* q, const std::string& qs)
 309         {
 310                 Parent()->Dispatcher->LockQueue();
 311                 Parent()->qq.push_back(QQueueItem(q, qs, this));
 312                 Parent()->Dispatcher->UnlockQueueWakeup();
 313         }
 314
 315         void submit(SQLQuery* call, const std::string& q, const ParamL& p)
 316         {
 317                 std::string res;
 318                 unsigned int param = 0;
 319                 for(std::string::size_type i = 0; i < q.length(); i++)
 320                 {
 321                         if (q[i] != '?')
 322                                 res.push_back(q[i]);
 323                         else
 324                         {
 325                                 if (param < p.size())
 326                                 {
 327                                         std::string parm = p[param++];
 328                                         // In the worst case, each character may need to be encoded as using two bytes,
 329                                         // and one byte is the terminating null
 330                                         std::vector<char> buffer(parm.length() * 2 + 1);
 331
 332                                         // The return value of mysql_escape_string() is the length of the encoded string,
 333                                         // not including the terminating null
 334                                         unsigned long escapedsize = mysql_escape_string(&buffer[0], parm.c_str(), parm.length());
 335 //                                      mysql_real_escape_string(connection, queryend, paramscopy[paramnum].c_str(), paramscopy[paramnum].length());
 336                                         res.append(&buffer[0], escapedsize);
 337                                 }
 338                         }
 339                 }
 340                 submit(call, res);
 341         }
 342
 343         void submit(SQLQuery* call, const std::string& q, const ParamM& p)
 344         {
 345                 std::string res;
 346                 for(std::string::size_type i = 0; i < q.length(); i++)
 347                 {
 348                         if (q[i] != '$')
 349                                 res.push_back(q[i]);
 350                         else
 351                         {
 352                                 std::string field;
 353                                 i++;
 354                                 while (i < q.length() && isalnum(q[i]))
 355                                         field.push_back(q[i++]);
 356                                 i--;
 357
 358                                 ParamM::const_iterator it = p.find(field);
 359                                 if (it != p.end())
 360                                 {
 361                                         std::string parm = it->second;
 362                                         // NOTE: See above
 363                                         std::vector<char> buffer(parm.length() * 2 + 1);
 364                                         unsigned long escapedsize = mysql_escape_string(&buffer[0], parm.c_str(), parm.length());
 365                                         res.append(&buffer[0], escapedsize);
 366                                 }
 367                         }
 368                 }
 369                 submit(call, res);
 370         }
 371 };
 372
 373 ModuleSQL::ModuleSQL()
 374 {
 375         Dispatcher = NULL;
 376 }
 377
 378 void ModuleSQL::init()
 379 {
 380         Dispatcher = new DispatcherThread(this);
 381         ServerInstance->Threads.Start(Dispatcher);
 382 }
 383
 384 ModuleSQL::~ModuleSQL()
 385 {
 386         if (Dispatcher)
 387         {
 388                 Dispatcher->join();
 389                 Dispatcher->OnNotify();
 390                 delete Dispatcher;
 391         }
 392         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 393         {
 394                 delete i->second;
 395         }
 396 }
 397
 398 void ModuleSQL::ReadConfig(ConfigStatus& status)
 399 {
 400         ConnMap conns;
 401         ConfigTagList tags = ServerInstance->Config->ConfTags("database");
 402         for(ConfigIter i = tags.first; i != tags.second; i++)
 403         {
 404                 if (i->second->getString("module", "mysql") != "mysql")
 405                         continue;
 406                 std::string id = i->second->getString("id");
 407                 ConnMap::iterator curr = connections.find(id);
 408                 if (curr == connections.end())
 409                 {
 410                         SQLConnection* conn = new SQLConnection(this, i->second);
 411                         conns.insert(std::make_pair(id, conn));
 412                         ServerInstance->Modules->AddService(*conn);
 413                 }
 414                 else
 415                 {
 416                         conns.insert(*curr);
 417                         connections.erase(curr);
 418                 }
 419         }
 420
 421         // now clean up the deleted databases
 422         Dispatcher->LockQueue();
 423         SQLerror err(SQL_BAD_DBID);
 424         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 425         {
 426                 ServerInstance->Modules->DelService(*i->second);
 427                 // it might be running a query on this database. Wait for that to complete
 428                 i->second->lock.Lock();
 429                 i->second->lock.Unlock();
 430                 // now remove all active queries to this DB
 431                 for (size_t j = qq.size(); j > 0; j--)
 432                 {
 433                         size_t k = j - 1;
 434                         if (qq[k].c == i->second)
 435                         {
 436                                 qq[k].q->OnError(err);
 437                                 delete qq[k].q;
 438                                 qq.erase(qq.begin() + k);
 439                         }
 440                 }
 441                 // finally, nuke the connection
 442                 delete i->second;
 443         }
 444         Dispatcher->UnlockQueue();
 445         connections.swap(conns);
 446 }
 447
 448 void ModuleSQL::OnUnloadModule(Module* mod)
 449 {
 450         SQLerror err(SQL_BAD_DBID);
 451         Dispatcher->LockQueue();
 452         unsigned int i = qq.size();
 453         while (i > 0)
 454         {
 455                 i--;
 456                 if (qq[i].q->creator == mod)
 457                 {
 458                         if (i == 0)
 459                         {
 460                                 // need to wait until the query is done
 461                                 // (the result will be discarded)
 462                                 qq[i].c->lock.Lock();
 463                                 qq[i].c->lock.Unlock();
 464                         }
 465                         qq[i].q->OnError(err);
 466                         delete qq[i].q;
 467                         qq.erase(qq.begin() + i);
 468                 }
 469         }
 470         Dispatcher->UnlockQueue();
 471         // clean up any result queue entries
 472         Dispatcher->OnNotify();
 473 }
 474
 475 Version ModuleSQL::GetVersion()
 476 {
 477         return Version("MySQL support", VF_VENDOR);
 478 }
 479
 480 void DispatcherThread::Run()
 481 {
 482         this->LockQueue();
 483         while (!this->GetExitFlag())
 484         {
 485                 if (!Parent->qq.empty())
 486                 {
 487                         QQueueItem i = Parent->qq.front();
 488                         i.c->lock.Lock();
 489                         this->UnlockQueue();
 490                         MySQLresult* res = i.c->DoBlockingQuery(i.query);
 491                         i.c->lock.Unlock();
 492
 493                         /*
 494                          * At this point, the main thread could be working on:
 495                          *  Rehash - delete i.c out from under us. We don't care about that.
 496                          *  UnloadModule - delete i.q and the qq item. Need to avoid reporting results.
 497                          */
 498
 499                         this->LockQueue();
 500                         if (!Parent->qq.empty() && Parent->qq.front().q == i.q)
 501                         {
 502                                 Parent->qq.pop_front();
 503                                 Parent->rq.push_back(RQueueItem(i.q, res));
 504                                 NotifyParent();
 505                         }
 506                         else
 507                         {
 508                                 // UnloadModule ate the query
 509                                 delete res;
 510                         }
 511                 }
 512                 else
 513                 {
 514                         /* We know the queue is empty, we can safely hang this thread until
 515                          * something happens
 516                          */
 517                         this->WaitForQueue();
 518                 }
 519         }
 520         this->UnlockQueue();
 521 }
 522
 523 void DispatcherThread::OnNotify()
 524 {
 525         // this could unlock during the dispatch, but OnResult isn't expected to take that long
 526         this->LockQueue();
 527         for(ResultQueue::iterator i = Parent->rq.begin(); i != Parent->rq.end(); i++)
 528         {
 529                 MySQLresult* res = i->r;
 530                 if (res->err.id == SQL_NO_ERROR)
 531                         i->q->OnResult(*res);
 532                 else
 533                         i->q->OnError(res->err);
 534                 delete i->q;
 535                 delete i->r;
 536         }
 537         Parent->rq.clear();
 538         this->UnlockQueue();
 539 }
 540
 541 MODULE_INIT(ModuleSQL)