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