src/modules/m_xline_db.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2008 Thomas Stagner <aquanight@inspircd.org>
   5  *   Copyright (C) 2008 Robin Burchell <robin+git@viroteck.net>
   6  *
   7  * This file is part of InspIRCd.  InspIRCd is free software: you can
   8  * redistribute it and/or modify it under the terms of the GNU General Public
   9  * License as published by the Free Software Foundation, version 2.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  13  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  14  * details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20
  21 #include "inspircd.h"
  22 #include "xline.h"
  23
  24 /* $ModConfig: <xlinedb filename="data/xline.db">
  25  *  Specify the filename for the xline database here*/
  26 /* $ModDesc: Keeps a dynamic log of all XLines created, and stores them in a seperate conf file (xline.db). */
  27
  28 class ModuleXLineDB : public Module
  29 {
  30         std::vector<XLine *> xlines;
  31         bool reading_db;                        // If this is true, addlines are as a result of db reading, so don't bother flushing the db to disk.
  32                                                 // DO REMEMBER TO SET IT, otherwise it's annoying :P
  33         std::string xlinedbpath;
  34  public:
  35         ModuleXLineDB()         {
  36                 Implementation eventlist[] = { I_OnAddLine, I_OnDelLine, I_OnExpireLine };
  37                 ServerInstance->Modules->Attach(eventlist, this, 3);
  38
  39                 /* Load the configuration
  40                  * Note:
  41                  *              this is on purpose not in the OnRehash() method. It would be non-trivial to change the database on-the-fly.
  42                  *              Imagine a scenario where the new file already exists. Merging the current XLines with the existing database is likely a bad idea
  43                  *              ...and so is discarding all current in-memory XLines for the ones in the database.
  44                  */
  45                 ConfigTag* Conf = ServerInstance->Config->ConfValue("xlinedb");
  46                 xlinedbpath = Conf->getString("filename", DATA_PATH "/xline.db");
  47
  48                 reading_db = true;
  49                 ReadDatabase();
  50                 reading_db = false;
  51         }
  52
  53         virtual ~ModuleXLineDB()
  54         {
  55         }
  56
  57         /** Called whenever an xline is added by a local user.
  58          * This method is triggered after the line is added.
  59          * @param source The sender of the line or NULL for local server
  60          * @param line The xline being added
  61          */
  62         void OnAddLine(User* source, XLine* line)
  63         {
  64                 ServerInstance->Logs->Log("m_xline_db",DEBUG, "xlinedb: Adding a line");
  65                 xlines.push_back(line);
  66
  67                 if (!reading_db)
  68                 {
  69                         WriteDatabase();
  70                 }
  71         }
  72
  73         /** Called whenever an xline is deleted.
  74          * This method is triggered after the line is deleted.
  75          * @param source The user removing the line or NULL for local server
  76          * @param line the line being deleted
  77          */
  78         void OnDelLine(User* source, XLine* line)
  79         {
  80                 RemoveLine(line);
  81         }
  82
  83         void OnExpireLine(XLine *line)
  84         {
  85                 RemoveLine(line);
  86         }
  87
  88         void RemoveLine(XLine *line)
  89         {
  90                 ServerInstance->Logs->Log("m_xline_db",DEBUG, "xlinedb: Removing a line");
  91                 for (std::vector<XLine *>::iterator i = xlines.begin(); i != xlines.end(); i++)
  92                 {
  93                         if ((*i) == line)
  94                         {
  95                                 xlines.erase(i);
  96                                 break;
  97                         }
  98                 }
  99
 100                 WriteDatabase();
 101         }
 102
 103         bool WriteDatabase()
 104         {
 105                 FILE *f;
 106
 107                 /*
 108                  * We need to perform an atomic write so as not to fuck things up.
 109                  * So, let's write to a temporary file, flush and sync the FD, then rename the file..
 110                  * Technically, that means that this can block, but I have *never* seen that.
 111                  *              -- w00t
 112                  */
 113                 ServerInstance->Logs->Log("m_xline_db",DEBUG, "xlinedb: Opening temporary database");
 114                 std::string xlinenewdbpath = xlinedbpath + ".new";
 115                 f = fopen(xlinenewdbpath.c_str(), "w");
 116                 if (!f)
 117                 {
 118                         ServerInstance->Logs->Log("m_xline_db",DEBUG, "xlinedb: Cannot create database! %s (%d)", strerror(errno), errno);
 119                         ServerInstance->SNO->WriteToSnoMask('a', "database: cannot create new db: %s (%d)", strerror(errno), errno);
 120                         return false;
 121                 }
 122
 123                 ServerInstance->Logs->Log("m_xline_db",DEBUG, "xlinedb: Opened. Writing..");
 124
 125                 /*
 126                  * Now, much as I hate writing semi-unportable formats, additional
 127                  * xline types may not have a conf tag, so let's just write them.
 128                  * In addition, let's use a file version, so we can maintain some
 129                  * semblance of backwards compatibility for reading on startup..
 130                  *              -- w00t
 131                  */
 132                 fprintf(f, "VERSION 1\n");
 133
 134                 // Now, let's write.
 135                 XLine *line;
 136                 for (std::vector<XLine *>::iterator i = xlines.begin(); i != xlines.end(); i++)
 137                 {
 138                         line = (*i);
 139                         fprintf(f, "LINE %s %s %s %lu %lu :%s\n", line->type.c_str(), line->Displayable(),
 140                                 ServerInstance->Config->ServerName.c_str(), (unsigned long)line->set_time, (unsigned long)line->duration, line->reason.c_str());
 141                 }
 142
 143                 ServerInstance->Logs->Log("m_xline_db",DEBUG, "xlinedb: Finished writing XLines. Checking for error..");
 144
 145                 int write_error = 0;
 146                 write_error = ferror(f);
 147                 write_error |= fclose(f);
 148                 if (write_error)
 149                 {
 150                         ServerInstance->Logs->Log("m_xline_db",DEBUG, "xlinedb: Cannot write to new database! %s (%d)", strerror(errno), errno);
 151                         ServerInstance->SNO->WriteToSnoMask('a', "database: cannot write to new db: %s (%d)", strerror(errno), errno);
 152                         return false;
 153                 }
 154
 155                 // Use rename to move temporary to new db - this is guarenteed not to fuck up, even in case of a crash.
 156                 if (rename(xlinenewdbpath.c_str(), xlinedbpath.c_str()) < 0)
 157                 {
 158                         ServerInstance->Logs->Log("m_xline_db",DEBUG, "xlinedb: Cannot move new to old database! %s (%d)", strerror(errno), errno);
 159                         ServerInstance->SNO->WriteToSnoMask('a', "database: cannot replace old with new db: %s (%d)", strerror(errno), errno);
 160                         return false;
 161                 }
 162
 163                 return true;
 164         }
 165
 166         bool ReadDatabase()
 167         {
 168                 FILE *f;
 169                 char linebuf[MAXBUF];
 170                 unsigned int lineno = 0;
 171
 172                 f = fopen(xlinedbpath.c_str(), "r");
 173                 if (!f)
 174                 {
 175                         if (errno == ENOENT)
 176                         {
 177                                 /* xline.db doesn't exist, fake good return value (we don't care about this) */
 178                                 return true;
 179                         }
 180                         else
 181                         {
 182                                 /* this might be slightly more problematic. */
 183                                 ServerInstance->Logs->Log("m_xline_db",DEBUG, "xlinedb: Cannot read database! %s (%d)", strerror(errno), errno);
 184                                 ServerInstance->SNO->WriteToSnoMask('a', "database: cannot read db: %s (%d)", strerror(errno), errno);
 185                                 return false;
 186                         }
 187                 }
 188
 189                 while (fgets(linebuf, MAXBUF, f))
 190                 {
 191                         char *c = linebuf;
 192
 193                         while (c && *c)
 194                         {
 195                                 if (*c == '\n')
 196                                 {
 197                                         *c = '\0';
 198                                 }
 199
 200                                 c++;
 201                         }
 202                         // Smart man might think of initing to 1, and moving this to the bottom. Don't. We use continue in this loop.
 203                         lineno++;
 204
 205                         // Inspired by the command parser. :)
 206                         irc::tokenstream tokens(linebuf);
 207                         int items = 0;
 208                         std::string command_p[MAXPARAMETERS];
 209                         std::string tmp;
 210
 211                         while (tokens.GetToken(tmp) && (items < MAXPARAMETERS))
 212                         {
 213                                 command_p[items] = tmp;
 214                                 items++;
 215                         }
 216
 217                         ServerInstance->Logs->Log("m_xline_db",DEBUG, "xlinedb: Processing %s", linebuf);
 218
 219                         if (command_p[0] == "VERSION")
 220                         {
 221                                 if (command_p[1] == "1")
 222                                 {
 223                                         ServerInstance->Logs->Log("m_xline_db",DEBUG, "xlinedb: Reading db version %s", command_p[1].c_str());
 224                                 }
 225                                 else
 226                                 {
 227                                         fclose(f);
 228                                         ServerInstance->Logs->Log("m_xline_db",DEBUG, "xlinedb: I got database version %s - I don't understand it", command_p[1].c_str());
 229                                         ServerInstance->SNO->WriteToSnoMask('a', "database: I got a database version (%s) I don't understand", command_p[1].c_str());
 230                                         return false;
 231                                 }
 232                         }
 233                         else if (command_p[0] == "LINE")
 234                         {
 235                                 // Mercilessly stolen from spanningtree
 236                                 XLineFactory* xlf = ServerInstance->XLines->GetFactory(command_p[1]);
 237
 238                                 if (!xlf)
 239                                 {
 240                                         ServerInstance->SNO->WriteToSnoMask('a', "database: Unknown line type (%s).", command_p[1].c_str());
 241                                         continue;
 242                                 }
 243
 244                                 XLine* xl = xlf->Generate(ServerInstance->Time(), atoi(command_p[5].c_str()), command_p[3], command_p[6], command_p[2]);
 245                                 xl->SetCreateTime(atoi(command_p[4].c_str()));
 246
 247                                 if (ServerInstance->XLines->AddLine(xl, NULL))
 248                                 {
 249                                         ServerInstance->SNO->WriteToSnoMask('x', "database: Added a line of type %s", command_p[1].c_str());
 250                                 }
 251                                 else
 252                                         delete xl;
 253                         }
 254                 }
 255
 256                 fclose(f);
 257                 return true;
 258         }
 259
 260
 261
 262         virtual Version GetVersion()
 263         {
 264                 return Version("Keeps a dynamic log of all XLines created, and stores them in a separate conf file (xline.db).", VF_VENDOR);
 265         }
 266 };
 267
 268 MODULE_INIT(ModuleXLineDB)
 269