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         // The destructor makes damn sure the socket is freed :)
  73
  74         ~RFC1413()
  75         {
  76                 if (this->fd != -1)
  77                 {
  78                         shutdown(this->fd,2);
  79                         close(this->fd);
  80                         this->fd = -1;
  81                 }
  82         }
  83
  84         // establish an ident connection, maxtime is the time to spend trying
  85         // returns true if successful, false if something was catastrophically wrong.
  86         // note that failed connects are not reported here but detected in RFC1413::Poll()
  87         // as the socket is nonblocking
  88
  89         bool Connect(userrec* user, int maxtime)
  90         {
  91                 timeout_end = time(NULL)+maxtime;
  92                 timeout = false;
  93                 if ((this->fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
  94                 {
  95                         // theres been a boo-boo... no more fd's left for us, woe is me!
  96                         Srv->Log(DEBUG,"Ident: socket failed for: "+std::string(user->ip));
  97                         return false;
  98                 }
  99                 inet_aton(user->ip,&addy);
 100                 addr.sin_family = AF_INET;
 101                 addr.sin_addr = addy;
 102                 addr.sin_port = htons(113);
 103
 104                 int flags;
 105                 flags = fcntl(this->fd, F_GETFL, 0);
 106                 fcntl(this->fd, F_SETFL, flags | O_NONBLOCK);
 107
 108                 if(connect(this->fd, (sockaddr*)&this->addr,sizeof(this->addr)) == -1)
 109                 {
 110                         // theres been an error, but EINPROGRESS just means 'right, im on it, call me later'
 111                         if (errno != EINPROGRESS)
 112                         {
 113                                 // ... so that error isnt fatal, like the rest.
 114                                 Srv->Log(DEBUG,"Ident: connect failed for: "+std::string(user->ip));
 115                                 shutdown(this->fd,2);
 116                                 close(this->fd);
 117                                 this->fd = -1;
 118                                 return false;
 119                         }
 120                 }
 121                 Srv->Log(DEBUG,"Ident: successful connect associated with user "+std::string(user->nick));
 122                 this->u = user;
 123                 this->state = IDENT_STATE_CONNECT;
 124                 return true;
 125         }
 126
 127         // Poll the socket to see if we have an ident result, and if we do apply it to the user.
 128         // returns false if we cannot poll for some reason (e.g. timeout).
 129
 130         bool Poll()
 131         {
 132                 if (time(NULL) > timeout_end)
 133                 {
 134                         timeout = true;
 135                         Srv->SendServ(u->fd,"NOTICE "+std::string(u->nick)+" :*** Could not find your ident, using "+std::string(u->ident)+" instead.");
 136                         shutdown(this->fd,2);
 137                         close(this->fd);
 138                         this->fd = -1;
 139                         return false;
 140                 }
 141                 pollfd polls;
 142                 polls.fd = this->fd;
 143                 if (state == IDENT_STATE_CONNECT)
 144                 {
 145                         // during state IDENT_STATE_CONNECT (leading up to the connect)
 146                         // we're watching for writeability
 147                         polls.events = POLLOUT;
 148                 }
 149                 else
 150                 {
 151                         // the rest of the time we're waiting for data
 152                         // back on the socket, or a socket close
 153                         polls.events = POLLIN;
 154                 }
 155                 int ret = poll(&polls,1,1);
 156
 157                 if (ret > 0)
 158                 {
 159                         switch (this->state)
 160                         {
 161                                 case IDENT_STATE_CONNECT:
 162                                         uslen = sizeof(sock_us);
 163                                         themlen = sizeof(sock_them);
 164                                         if ((getsockname(this->u->fd,(sockaddr*)&sock_us,&uslen) || getpeername(this->u->fd, (sockaddr*)&sock_them, &themlen)))
 165                                         {
 166                                                 Srv->Log(DEBUG,"Ident: failed to get socket names, bailing to state 3");
 167                                                 shutdown(this->fd,2);
 168                                                 close(this->fd);
 169                                                 this->fd = -1;
 170                                                 state = IDENT_STATE_DONE;
 171                                         }
 172                                         else
 173                                         {
 174                                                 // send the request in the following format: theirsocket,oursocket
 175                                                 Write(this->fd,"%d,%d",ntohs(sock_them.sin_port),ntohs(sock_us.sin_port));
 176                                                 Srv->Log(DEBUG,"Sent ident request, moving to state 2");
 177                                                 state = IDENT_STATE_WAITDATA;
 178                                         }
 179                                 break;
 180                                 case IDENT_STATE_WAITDATA:
 181                                         nrecv = recv(this->fd,ibuf,sizeof(ibuf),0);
 182                                         if (nrecv > 0)
 183                                         {
 184                                                 // we have the response line in the following format:
 185                                                 // 6193, 23 : USERID : UNIX : stjohns
 186                                                 // 6195, 23 : ERROR : NO-USER
 187                                                 ibuf[nrecv] = '\0';
 188                                                 Srv->Log(DEBUG,"Received ident response: "+std::string(ibuf));
 189                                                 shutdown(this->fd,2);
 190                                                 close(this->fd);
 191                                                 this->fd = -1;
 192                                                 char* savept;
 193                                                 char* section = strtok_r(ibuf,":",&savept);
 194                                                 while (section)
 195                                                 {
 196                                                         if (strstr(section,"USERID"))
 197                                                         {
 198                                                                 section = strtok_r(NULL,":",&savept);
 199                                                                 if (section)
 200                                                                 {
 201                                                                         // ID type, usually UNIX or OTHER... we dont want it, so read the next token
 202                                                                         section = strtok_r(NULL,":",&savept);
 203                                                                         if (section)
 204                                                                         {
 205                                                                                 while ((*section == ' ') && (strlen(section)>0)) section++; // strip leading spaces
 206                                                                                 int t = strlen(section);
 207                                                                                 for (int j = 0; j < t; j++)
 208                                                                                         if ((section[j] < 33) || (section[j]>126))
 209                                                                                                 section[j] = '\0'; // truncate at invalid chars
 210                                                                                 if (strlen(section))
 211                                                                                 {
 212                                                                                         strlcpy(u->ident,section,IDENTMAX);
 213                                                                                         Srv->Log(DEBUG,"IDENT SET: "+std::string(u->ident));
 214                                                                                         Srv->SendServ(u->fd,"NOTICE "+std::string(u->nick)+" :*** Found your ident: "+std::string(u->ident));
 215                                                                                 }
 216                                                                                 break;
 217                                                                         }
 218                                                                 }
 219                                                         }
 220                                                         section = strtok_r(NULL,":",&savept);
 221                                                 }
 222                                                 state = IDENT_STATE_DONE;
 223                                         }
 224                                 break;
 225                                 case IDENT_STATE_DONE:
 226                                         shutdown(this->fd,2);
 227                                         close(this->fd);
 228                                         this->fd = -1;
 229                                         Srv->Log(DEBUG,"Ident lookup is complete!");
 230                                 break;
 231                                 default:
 232                                         Srv->Log(DEBUG,"Ident: invalid ident state!!!");
 233                                 break;
 234                         }
 235                 }
 236         }
 237
 238         // returns true if the operation is completed,
 239         // either due to complete request, or a timeout
 240
 241         bool Done()
 242         {
 243                 return ((state == IDENT_STATE_DONE) || (timeout == true));
 244         }
 245 };
 246
 247 class ModuleIdent : public Module
 248 {
 249
 250         ConfigReader* Conf;
 251         int IdentTimeout;
 252
 253  public:
 254         void ReadSettings()
 255         {
 256                 Conf = new ConfigReader;
 257                 IdentTimeout = Conf->ReadInteger("ident","timeout",0,true);
 258                 delete Conf;
 259         }
 260
 261         ModuleIdent()
 262         {
 263                 Srv = new Server;
 264                 ReadSettings();
 265         }
 266
 267         virtual void OnRehash()
 268         {
 269                 ReadSettings();
 270         }
 271
 272         virtual void OnUserRegister(userrec* user)
 273         {
 274                 // when the new user connects, before they authenticate with USER/NICK/PASS, we do
 275                 // their ident lookup.
 276
 277                 RFC1413* ident = new RFC1413;
 278                 Srv->SendServ(user->fd,"NOTICE "+std::string(user->nick)+" :*** Looking up your ident...");
 279                 if (ident->Connect(user,IdentTimeout))
 280                 {
 281                         // attach the object to the user record
 282                         user->Extend("ident_data",(char*)ident);
 283                         // start it off polling (always good to have a head start)
 284                         // because usually connect has completed by now
 285                         ident->Poll();
 286                 }
 287                 else
 288                 {
 289                         // something went wrong, call an irc-ambulance!
 290                         Srv->SendServ(user->fd,"NOTICE "+std::string(user->nick)+" :*** Could not look up your ident.");
 291                         delete ident;
 292                 }
 293         }
 294
 295         virtual bool OnCheckReady(userrec* user)
 296         {
 297                 RFC1413* ident = (RFC1413*)user->GetExt("ident_data");
 298                 if (ident)
 299                 {
 300                         // this user has a pending ident lookup, poll it
 301                         ident->Poll();
 302                         // is it done?
 303                         if (ident->Done())
 304                         {
 305                                 // their ident is done, zap the structures
 306                                 Srv->Log(DEBUG,"Ident: removing ident gubbins");
 307                                 user->Shrink("ident_data");
 308                                 delete ident;
 309                                 // ...and send them on their way
 310                                 return true;
 311                         }
 312                         // nope, we hold them in this state, they dont go anywhere
 313                         return false;
 314                 }
 315                 return true;
 316         }
 317
 318         virtual void OnUserDisconnect(userrec* user)
 319         {
 320                 // when the user quits tidy up any ident lookup they have pending to keep things tidy
 321                 // and to prevent a memory and FD leaks
 322                 RFC1413* ident = (RFC1413*)user->GetExt("ident_data");
 323                 if (ident)
 324                 {
 325                         delete ident;
 326                         user->Shrink("ident_data");
 327                 }
 328         }
 329
 330         virtual ~ModuleIdent()
 331         {
 332                 delete Srv;
 333         }
 334
 335         virtual Version GetVersion()
 336         {
 337                 return Version(1,0,0,1,VF_VENDOR);
 338         }
 339
 340 };
 341
 342 class ModuleIdentFactory : public ModuleFactory
 343 {
 344  public:
 345         ModuleIdentFactory()
 346         {
 347         }
 348
 349         ~ModuleIdentFactory()
 350         {
 351         }
 352
 353         virtual Module * CreateModule()
 354         {
 355                 return new ModuleIdent;
 356         }
 357
 358 };
 359
 360
 361 extern "C" void * init_module( void )
 362 {
 363         return new ModuleIdentFactory;
 364 }
 365