src/modules/m_ident.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  Inspire 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 #include <stdio.h>
  18 #include <string>
  19 #include <stdlib.h>
  20 #include <time.h>
  21 #include <sys/types.h>
  22 #include <sys/socket.h>
  23 #include <sys/time.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26 #include <errno.h>
  27 #include <fcntl.h>
  28 #include <poll.h>
  29 #include "users.h"
  30 #include "channels.h"
  31 #include "modules.h"
  32 #include "inspircd.h"
  33
  34 /* $ModDesc: Provides support for RFC 1413 ident lookups */
  35
  36 Server *Srv;
  37
  38 // State engine constants. We have three states,
  39 // connecting, waiting for data, and finished.
  40
  41 #define IDENT_STATE_CONNECT     1
  42 #define IDENT_STATE_WAITDATA    2
  43 #define IDENT_STATE_DONE        3
  44
  45 // Ident lookups are done by attaching an RFC1413 class to the
  46 // userrec record using the Extensible system.
  47 // The RFC1413 class is written especially for this module but
  48 // it should be relatively standalone for anyone else who wishes
  49 // to have a nonblocking ident lookup in a program :)
  50 // the class operates on a simple state engine, each state of the
  51 // connection incrementing a state counter, leading through to
  52 // a concluding state which terminates the lookup.
  53
  54 class RFC1413
  55 {
  56  protected:
  57         int fd;                 // file descriptor
  58         userrec* u;             // user record that the lookup is associated with
  59         sockaddr_in addr;       // address we're connecting to
  60         in_addr addy;           // binary ip address
  61         int state;              // state (this class operates on a state engine)
  62         char ibuf[MAXBUF];      // input buffer
  63         sockaddr_in sock_us;    // our port number
  64         sockaddr_in sock_them;  // their port number
  65         socklen_t uslen;        // length of our port number
  66         socklen_t themlen;      // length of their port number
  67         int nrecv;              // how many bytes we've received
  68         time_t timeout_end;     // how long until the operation times out
  69         bool timeout;           // true if we've timed out and should bail
  70  public:
  71
  72         // establish an ident connection, maxtime is the time to spend trying
  73         // returns true if successful, false if something was catastrophically wrong.
  74         // note that failed connects are not reported here but detected in RFC1413::Poll()
  75         // as the socket is nonblocking
  76
  77         bool Connect(userrec* user, int maxtime)
  78         {
  79                 timeout_end = time(NULL)+maxtime;
  80                 timeout = false;
  81                 if ((this->fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
  82                 {
  83                         // theres been a boo-boo... no more fd's left for us, woe is me!
  84                         Srv->Log(DEBUG,"Ident: socket failed for: "+std::string(user->ip));
  85                         return false;
  86                 }
  87                 inet_aton(user->ip,&addy);
  88                 addr.sin_family = AF_INET;
  89                 addr.sin_addr = addy;
  90                 addr.sin_port = htons(113);
  91
  92                 int flags;
  93                 flags = fcntl(this->fd, F_GETFL, 0);
  94                 fcntl(this->fd, F_SETFL, flags | O_NONBLOCK);
  95
  96                 if(connect(this->fd, (sockaddr*)&this->addr,sizeof(this->addr)) == -1)
  97                 {
  98                         // theres been an error, but EINPROGRESS just means 'right, im on it, call me later'
  99                         if (errno != EINPROGRESS)
 100                         {
 101                                 // ... so that error isnt fatal, like the rest.
 102                                 Srv->Log(DEBUG,"Ident: connect failed for: "+std::string(user->ip));
 103                                 close(this->fd);
 104                                 shutdown(this->fd,2);
 105                                 return false;
 106                         }
 107                 }
 108                 Srv->Log(DEBUG,"Ident: successful connect associated with user "+std::string(user->nick));
 109                 this->u = user;
 110                 this->state = IDENT_STATE_CONNECT;
 111                 return true;
 112         }
 113
 114         // Poll the socket to see if we have an ident result, and if we do apply it to the user.
 115         // returns false if we cannot poll for some reason (e.g. timeout).
 116
 117         bool Poll()
 118         {
 119                 if (time(NULL) > timeout_end)
 120                 {
 121                         timeout = true;
 122                         Srv->SendServ(u->fd,"NOTICE "+std::string(u->nick)+" :*** Could not find your ident, using "+std::string(u->ident)+" instead.");
 123                         close(this->fd);
 124                         shutdown(this->fd,2);
 125                         return false;
 126                 }
 127                 pollfd polls;
 128                 polls.fd = this->fd;
 129                 if (state == IDENT_STATE_CONNECT)
 130                 {
 131                         // during state IDENT_STATE_CONNECT (leading up to the connect)
 132                         // we're watching for writeability
 133                         polls.events = POLLOUT;
 134                 }
 135                 else
 136                 {
 137                         // the rest of the time we're waiting for data
 138                         // back on the socket, or a socket close
 139                         polls.events = POLLIN;
 140                 }
 141                 int ret = poll(&polls,1,1);
 142
 143                 if (ret > 0)
 144                 {
 145                         switch (this->state)
 146                         {
 147                                 case IDENT_STATE_CONNECT:
 148                                         Srv->Log(DEBUG,"*** IDENT IN STATE 1");
 149                                         uslen = sizeof(sock_us);
 150                                         themlen = sizeof(sock_them);
 151                                         if ((getsockname(this->u->fd,(sockaddr*)&sock_us,&uslen) || getpeername(this->u->fd, (sockaddr*)&sock_them, &themlen)))
 152                                         {
 153                                                 Srv->Log(DEBUG,"Ident: failed to get socket names, bailing to state 3");
 154                                                 close(this->fd);
 155                                                 shutdown(this->fd,2);
 156                                                 state = IDENT_STATE_DONE;
 157                                         }
 158                                         else
 159                                         {
 160                                                 // send the request in the following format: theirsocket,oursocket
 161                                                 Write(this->fd,"%d,%d",ntohs(sock_them.sin_port),ntohs(sock_us.sin_port));
 162                                                 Srv->Log(DEBUG,"Sent ident request, moving to state 2");
 163                                                 state = IDENT_STATE_WAITDATA;
 164                                         }
 165                                 break;
 166                                 case IDENT_STATE_WAITDATA:
 167                                         Srv->Log(DEBUG,"*** IDENT IN STATE 2");
 168                                         nrecv = recv(this->fd,ibuf,sizeof(ibuf),0);
 169                                         if (nrecv > 0)
 170                                         {
 171                                                 // we have the response line in the following format:
 172                                                 // 6193, 23 : USERID : UNIX : stjohns
 173                                                 // 6195, 23 : ERROR : NO-USER
 174                                                 ibuf[nrecv] = '\0';
 175                                                 Srv->Log(DEBUG,"Received ident response: "+std::string(ibuf));
 176                                                 close(this->fd);
 177                                                 shutdown(this->fd,2);
 178                                                 char* savept;
 179                                                 char* section = strtok_r(ibuf,":",&savept);
 180                                                 while (section)
 181                                                 {
 182                                                         if (strstr(section,"USERID"))
 183                                                         {
 184                                                                 section = strtok_r(NULL,":",&savept);
 185                                                                 if (section)
 186                                                                 {
 187                                                                         // ID type, usually UNIX or OTHER... we dont want it, so read the next token
 188                                                                         section = strtok_r(NULL,":",&savept);
 189                                                                         if (section)
 190                                                                         {
 191                                                                                 while ((*section == ' ') && (strlen(section)>0)) section++; // strip leading spaces
 192                                                                                 int t = strlen(section);
 193                                                                                 for (int j = 0; j < t; j++)
 194                                                                                         if ((section[j] < 33) || (section[j]>126))
 195                                                                                                 section[j] = '\0'; // truncate at invalid chars
 196                                                                                 if (strlen(section))
 197                                                                                 {
 198                                                                                         strlcpy(u->ident,section,IDENTMAX);
 199                                                                                         Srv->Log(DEBUG,"IDENT SET: "+std::string(u->ident));
 200                                                                                         Srv->SendServ(u->fd,"NOTICE "+std::string(u->nick)+" :*** Found your ident: "+std::string(u->ident));
 201                                                                                 }
 202                                                                                 break;
 203                                                                         }
 204                                                                 }
 205                                                         }
 206                                                         section = strtok_r(NULL,":",&savept);
 207                                                 }
 208                                                 state = IDENT_STATE_DONE;
 209                                         }
 210                                 break;
 211                                 case IDENT_STATE_DONE:
 212                                         Srv->Log(DEBUG,"Ident lookup is complete!");
 213                                 break;
 214                                 default:
 215                                         Srv->Log(DEBUG,"Ident: invalid ident state!!!");
 216                                 break;
 217                         }
 218                 }
 219         }
 220
 221         // returns true if the operation is completed,
 222         // either due to complete request, or a timeout
 223
 224         bool Done()
 225         {
 226                 return ((state == 3) || (timeout == true));
 227         }
 228 };
 229
 230 class ModuleIdent : public Module
 231 {
 232
 233         ConfigReader* Conf;
 234         int IdentTimeout;
 235
 236  public:
 237         void ReadSettings()
 238         {
 239                 Conf = new ConfigReader;
 240                 IdentTimeout = Conf->ReadInteger("ident","timeout",0,true);
 241                 delete Conf;
 242         }
 243
 244         ModuleIdent()
 245         {
 246                 Srv = new Server;
 247                 ReadSettings();
 248         }
 249
 250         virtual void OnRehash()
 251         {
 252                 ReadSettings();
 253         }
 254
 255         virtual void OnUserRegister(userrec* user)
 256         {
 257                 // when the new user connects, before they authenticate with USER/NICK/PASS, we do
 258                 // their ident lookup.
 259
 260                 RFC1413* ident = new RFC1413;
 261                 Srv->SendServ(user->fd,"NOTICE "+std::string(user->nick)+" :*** Looking up your ident...");
 262                 if (ident->Connect(user,IdentTimeout))
 263                 {
 264                         // attach the object to the user record
 265                         user->Extend("ident_data",(char*)ident);
 266                         // start it off polling (always good to have a head start)
 267                         // because usually connect has completed by now
 268                         ident->Poll();
 269                 }
 270                 else
 271                 {
 272                         // something went wrong, call an irc-ambulance!
 273                         Srv->SendServ(user->fd,"NOTICE "+std::string(user->nick)+" :*** Could not look up your ident.");
 274                         delete ident;
 275                 }
 276         }
 277
 278         virtual bool OnCheckReady(userrec* user)
 279         {
 280                 RFC1413* ident = (RFC1413*)user->GetExt("ident_data");
 281                 if (ident)
 282                 {
 283                         // this user has a pending ident lookup, poll it
 284                         ident->Poll();
 285                         // is it done?
 286                         if (ident->Done())
 287                         {
 288                                 // their ident is done, zap the structures
 289                                 Srv->Log(DEBUG,"Ident: removing ident gubbins");
 290                                 user->Shrink("ident_data");
 291                                 delete ident;
 292                                 // ...and send them on their way
 293                                 return true;
 294                         }
 295                         // nope, we hold them in this state, they dont go anywhere
 296                         return false;
 297                 }
 298                 return true;
 299         }
 300
 301         virtual ~ModuleIdent()
 302         {
 303                 delete Srv;
 304         }
 305
 306         virtual Version GetVersion()
 307         {
 308                 return Version(1,0,0,1,VF_VENDOR);
 309         }
 310
 311 };
 312
 313 class ModuleIdentFactory : public ModuleFactory
 314 {
 315  public:
 316         ModuleIdentFactory()
 317         {
 318         }
 319
 320         ~ModuleIdentFactory()
 321         {
 322         }
 323
 324         virtual Module * CreateModule()
 325         {
 326                 return new ModuleIdent;
 327         }
 328
 329 };
 330
 331
 332 extern "C" void * init_module( void )
 333 {
 334         return new ModuleIdentFactory;
 335 }
 336