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