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