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