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