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 #include "inspircd.h"
  31
  32 extern InspIRCd* ServerInstance;
  33
  34 class FilterPCREException : public ModuleException
  35 {
  36  public:
  37         virtual const char* GetReason()
  38         {
  39                 return "Could not find <filter file=\"\"> definition in your config file!";
  40         }
  41 };
  42
  43 /* $ModDesc: m_filter with regexps */
  44 /* $CompileFlags: -I/usr/local/include */
  45 /* $LinkerFlags: -L/usr/local/lib -lpcre */
  46
  47 class ModuleFilterPCRE : public Module
  48 {
  49         Server *Srv;
  50         ConfigReader *Conf, *MyConf;
  51         std::vector<pcre*> filters;
  52         pcre *re;
  53         const char *error;
  54         int erroffset;
  55
  56  public:
  57         ModuleFilterPCRE(InspIRCd* Me)
  58                 : Module::Module(Me)
  59         {
  60                 // read the configuration file on startup.
  61                 // it is perfectly valid to set <filter file> to the value of the
  62                 // main config file, then append your <keyword> tags to the bottom
  63                 // of the main config... but rather messy. That's why the capability
  64                 // of using a seperate config file is provided.
  65
  66                 Conf = new ConfigReader;
  67                 std::string filterfile = Conf->ReadValue("filter","file",0);
  68                 MyConf = new ConfigReader(filterfile);
  69                 if ((filterfile == "") || (!MyConf->Verify()))
  70                 {
  71                         FilterPCREException e;
  72                         throw(e);
  73                 }
  74                 log(DEFAULT,"m_filter_pcre: read configuration from "+filterfile);
  75
  76                 filters.clear();
  77                 for (int index = 0; index < MyConf->Enumerate("keyword"); index++)
  78                 {
  79                         std::string pattern = MyConf->ReadValue("keyword","pattern",index);
  80                         re = pcre_compile(pattern.c_str(),0,&error,&erroffset,NULL);
  81                         if (!re)
  82                         {
  83                                 log(DEFAULT,"Error in regular expression: %s at offset %d: %s\n", pattern.c_str(), erroffset, error);
  84                                 log(DEFAULT,"Regular expression %s not loaded.", pattern.c_str());
  85                         }
  86                         else
  87                         {
  88                                 filters.push_back(re);
  89                                 log(DEFAULT,"Regular expression %s loaded.", pattern.c_str());
  90                         }
  91                 }
  92
  93         }
  94
  95         virtual ~ModuleFilterPCRE()
  96         {
  97                 DELETE(MyConf);
  98                 DELETE(Conf);
  99         }
 100
 101         void Implements(char* List)
 102         {
 103                 List[I_OnUserPreMessage] = List[I_OnUserPreNotice] = List[I_OnRehash] = 1;
 104         }
 105
 106         // format of a config entry is <keyword pattern="^regexp$" reason="Some reason here" action="kill/block">
 107
 108         virtual int OnUserPreMessage(userrec* user,void* dest,int target_type, std::string &text, char status)
 109         {
 110                 return OnUserPreNotice(user,dest,target_type,text,status);
 111         }
 112
 113         virtual int OnUserPreNotice(userrec* user,void* dest,int target_type, std::string &text, char status)
 114         {
 115                 for (unsigned int index = 0; index < filters.size(); index++)
 116                 {
 117                         if (pcre_exec(filters[index],NULL,text.c_str(),text.length(),0,0,NULL,0) > -1)
 118                         {
 119                                 const char* target;
 120                                 std::string reason = MyConf->ReadValue("keyword","reason",index);
 121                                 std::string do_action = MyConf->ReadValue("keyword","action",index);
 122
 123                                 if (do_action == "")
 124                                         do_action = "none";
 125
 126                                 if (target_type == TYPE_USER)
 127                                 {
 128                                         userrec* t = (userrec*)dest;
 129                                         target = t->nick;
 130                                 }
 131                                 else if (target_type == TYPE_CHANNEL)
 132                                 {
 133                                         chanrec* t = (chanrec*)dest;
 134                                         target = t->name;
 135                                 }
 136                                 else
 137                                 {
 138                                         target = "";
 139                                 }
 140
 141                                 if (do_action == "block")
 142                                 {
 143                                         ServerInstance->WriteOpers("Filter: %s had their notice filtered, target was %s: %s", user->nick, target, reason.c_str());
 144                                         user->WriteServ("NOTICE "+std::string(user->nick)+" :Your notice has been filtered and opers notified: "+reason);
 145                         }
 146
 147                                 log(DEFAULT, "Filter: %s had their notice filtered, target was %s: %s Action: %s", user->nick, target, reason.c_str(), do_action.c_str());
 148
 149                                 if (do_action == "kill")
 150                                 {
 151                                         userrec::QuitUser(ServerInstance,user,reason);
 152                                 }
 153                                 return 1;
 154                         }
 155                 }
 156                 return 0;
 157         }
 158
 159         virtual void OnRehash(const std::string &parameter)
 160         {
 161                 // reload our config file on rehash - we must destroy and re-allocate the classes
 162                 // to call the constructor again and re-read our data.
 163                 DELETE(Conf);
 164                 DELETE(MyConf);
 165                 Conf = new ConfigReader;
 166                 std::string filterfile = Conf->ReadValue("filter","file",0);
 167                 // this automatically re-reads the configuration file into the class
 168                 MyConf = new ConfigReader(filterfile);
 169                 if ((filterfile == "") || (!MyConf->Verify()))
 170                 {
 171                         FilterPCREException e;
 172                         // bail if the user forgot to create a config file
 173                         throw(e);
 174                 }
 175                 log(DEFAULT,"m_filter_pcre: read configuration from "+filterfile);
 176
 177                 filters.clear();
 178                 for (int index = 0; index < MyConf->Enumerate("keyword"); index++)
 179                 {
 180                         std::string pattern = MyConf->ReadValue("keyword","pattern",index);
 181                         re = pcre_compile(pattern.c_str(),0,&error,&erroffset,NULL);
 182                         if (!re)
 183                         {
 184                                 log(DEFAULT,"Error in regular expression: %s at offset %d: %s\n", pattern.c_str(), erroffset, error);
 185                                 log(DEFAULT,"Regular expression %s not loaded.", pattern.c_str());
 186                         }
 187                         else
 188                         {
 189                                 filters.push_back(re);
 190                                 log(DEFAULT,"Regular expression %s loaded.", pattern.c_str());
 191                         }
 192                 }
 193
 194         }
 195
 196         virtual Version GetVersion()
 197         {
 198                 // This is version 2 because version 1.x is the unreleased unrealircd module
 199                 return Version(3,0,0,0,VF_VENDOR);
 200         }
 201
 202 };
 203
 204 // stuff down here is the module-factory stuff. For basic modules you can ignore this.
 205
 206 class ModuleFilterPCREFactory : public ModuleFactory
 207 {
 208  public:
 209         ModuleFilterPCREFactory()
 210         {
 211         }
 212
 213         ~ModuleFilterPCREFactory()
 214         {
 215         }
 216
 217         virtual Module * CreateModule(InspIRCd* Me)
 218         {
 219                 return new ModuleFilterPCRE(Me);
 220         }
 221
 222 };
 223
 224
 225 extern "C" void * init_module( void )
 226 {
 227         return new ModuleFilterPCREFactory;
 228 }