src/modules/extra/m_filter_pcre.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd is copyright (C) 2002-2004 ChatSpike-Dev.
   6  *                       E-mail:
   7  *                <brain@chatspike.net>
   8  *                <Craig@chatspike.net>
   9  *
  10  * Written by Craig Edwards, Craig McLure, and others.
  11  * This program is free but copyrighted software; see
  12  *            the file COPYING for details.
  13  *
  14  * ---------------------------------------------------
  15  */
  16
  17 using namespace std;
  18
  19 // Message and notice filtering using regex patterns
  20 // a module based on the original work done by Craig Edwards in 2003
  21 // for the chatspike network.
  22
  23 #include <stdio.h>
  24 #include <string>
  25 #include <pcre.h>
  26 #include "users.h"
  27 #include "channels.h"
  28 #include "modules.h"
  29 #include "helperfuncs.h"
  30
  31 class FilterPCREException : public ModuleException
  32 {
  33  public:
  34         virtual const char* GetReason()
  35         {
  36                 return "Could not find <filter file=\"\"> definition in your config file!";
  37         }
  38 };
  39
  40 /* $ModDesc: m_filter with regexps */
  41 /* $CompileFlags: -I/usr/local/include */
  42 /* $LinkerFlags: -L/usr/local/lib -lpcre */
  43
  44 class ModuleFilterPCRE : public Module
  45 {
  46         Server *Srv;
  47         ConfigReader *Conf, *MyConf;
  48         std::vector<pcre*> filters;
  49         pcre *re;
  50         const char *error;
  51         int erroffset;
  52
  53  public:
  54         ModuleFilterPCRE(Server* Me)
  55                 : Module::Module(Me)
  56         {
  57                 // read the configuration file on startup.
  58                 // it is perfectly valid to set <filter file> to the value of the
  59                 // main config file, then append your <keyword> tags to the bottom
  60                 // of the main config... but rather messy. That's why the capability
  61                 // of using a seperate config file is provided.
  62                 Srv = Me;
  63                 Conf = new ConfigReader;
  64                 std::string filterfile = Conf->ReadValue("filter","file",0);
  65                 MyConf = new ConfigReader(filterfile);
  66                 if ((filterfile == "") || (!MyConf->Verify()))
  67                 {
  68                         FilterPCREException e;
  69                         throw(e);
  70                 }
  71                 Srv->Log(DEFAULT,std::string("m_filter_pcre: read configuration from ")+filterfile);
  72
  73                 filters.clear();
  74                 for (int index = 0; index < MyConf->Enumerate("keyword"); index++)
  75                 {
  76                         std::string pattern = MyConf->ReadValue("keyword","pattern",index);
  77                         re = pcre_compile(pattern.c_str(),0,&error,&erroffset,NULL);
  78                         if (!re)
  79                         {
  80                                 log(DEFAULT,"Error in regular expression: %s at offset %d: %s\n", pattern.c_str(), erroffset, error);
  81                                 log(DEFAULT,"Regular expression %s not loaded.", pattern.c_str());
  82                         }
  83                         else
  84                         {
  85                                 filters.push_back(re);
  86                                 log(DEFAULT,"Regular expression %s loaded.", pattern.c_str());
  87                         }
  88                 }
  89
  90         }
  91
  92         virtual ~ModuleFilterPCRE()
  93         {
  94                 delete MyConf;
  95                 delete Conf;
  96         }
  97
  98         void Implements(char* List)
  99         {
 100                 List[I_OnUserPreMessage] = List[I_OnUserPreNotice] = List[I_OnRehash] = 1;
 101         }
 102
 103         // format of a config entry is <keyword pattern="^regexp$" reason="Some reason here" action="kill/block">
 104
 105         virtual int OnUserPreMessage(userrec* user,void* dest,int target_type, std::string &text, char status)
 106         {
 107                 return OnUserPreNotice(user,dest,target_type,text,status);
 108         }
 109
 110         virtual int OnUserPreNotice(userrec* user,void* dest,int target_type, std::string &text, char status)
 111         {
 112                 for (unsigned int index = 0; index < filters.size(); index++)
 113                 {
 114                         if (pcre_exec(filters[index],NULL,text.c_str(),text.length(),0,0,NULL,0) > -1)
 115                         {
 116                                 std::string target = "";
 117                                 std::string reason = MyConf->ReadValue("keyword","reason",index);
 118                                 std::string do_action = MyConf->ReadValue("keyword","action",index);
 119
 120                                 if (do_action == "")
 121                                         do_action = "none";
 122
 123                                 if (target_type == TYPE_USER)
 124                                 {
 125                                         userrec* t = (userrec*)dest;
 126                                         target = std::string(t->nick);
 127                                 }
 128                                 else if (target_type == TYPE_CHANNEL)
 129                                 {
 130                                         chanrec* t = (chanrec*)dest;
 131                                         target = std::string(t->name);
 132                                 }
 133                                 if (do_action == "block")
 134                                 {
 135                                         Srv->SendOpers(std::string("Filter: ")+std::string(user->nick)+
 136                                                         std::string(" had their notice filtered, target was ")+
 137                                                         target+": "+reason);
 138                                         Srv->SendTo(NULL,user,"NOTICE "+std::string(user->nick)+
 139                                                         " :Your notice has been filtered and opers notified: "+reason);
 140                                 }
 141                                 Srv->Log(DEFAULT,std::string("Filter: ")+std::string(user->nick)+
 142                                                 std::string(" had their notice filtered, target was ")+
 143                                                 target+": "+reason+" Action: "+do_action);
 144
 145                                 if (do_action == "kill")
 146                                 {
 147                                         Srv->QuitUser(user,reason);
 148                                 }
 149                                 return 1;
 150                         }
 151                 }
 152                 return 0;
 153         }
 154
 155         virtual void OnRehash(const std::string &parameter)
 156         {
 157                 // reload our config file on rehash - we must destroy and re-allocate the classes
 158                 // to call the constructor again and re-read our data.
 159                 delete Conf;
 160                 delete MyConf;
 161                 Conf = new ConfigReader;
 162                 std::string filterfile = Conf->ReadValue("filter","file",0);
 163                 // this automatically re-reads the configuration file into the class
 164                 MyConf = new ConfigReader(filterfile);
 165                 if ((filterfile == "") || (!MyConf->Verify()))
 166                 {
 167                         FilterPCREException e;
 168                         // bail if the user forgot to create a config file
 169                         throw(e);
 170                 }
 171                 Srv->Log(DEFAULT,std::string("m_filter_pcre: read configuration from ")+filterfile);
 172
 173                 filters.clear();
 174                 for (int index = 0; index < MyConf->Enumerate("keyword"); index++)
 175                 {
 176                         std::string pattern = MyConf->ReadValue("keyword","pattern",index);
 177                         re = pcre_compile(pattern.c_str(),0,&error,&erroffset,NULL);
 178                         if (!re)
 179                         {
 180                                 log(DEFAULT,"Error in regular expression: %s at offset %d: %s\n", pattern.c_str(), erroffset, error);
 181                                 log(DEFAULT,"Regular expression %s not loaded.", pattern.c_str());
 182                         }
 183                         else
 184                         {
 185                                 filters.push_back(re);
 186                                 log(DEFAULT,"Regular expression %s loaded.", pattern.c_str());
 187                         }
 188                 }
 189
 190         }
 191
 192         virtual Version GetVersion()
 193         {
 194                 // This is version 2 because version 1.x is the unreleased unrealircd module
 195                 return Version(3,0,0,0,VF_VENDOR);
 196         }
 197
 198 };
 199
 200 // stuff down here is the module-factory stuff. For basic modules you can ignore this.
 201
 202 class ModuleFilterPCREFactory : public ModuleFactory
 203 {
 204  public:
 205         ModuleFilterPCREFactory()
 206         {
 207         }
 208
 209         ~ModuleFilterPCREFactory()
 210         {
 211         }
 212
 213         virtual Module * CreateModule(Server* Me)
 214         {
 215                 return new ModuleFilterPCRE(Me);
 216         }
 217
 218 };
 219
 220
 221 extern "C" void * init_module( void )
 222 {
 223         return new ModuleFilterPCREFactory;
 224 }
 225