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         char ident_request[128]; // buffer used to make up the request string
  71  public:
  72
  73         // The destructor makes damn sure the socket is freed :)
  74
  75         ~RFC1413()
  76         {
  77                 if (this->fd != -1)
  78                 {
  79                         shutdown(this->fd,2);
  80                         close(this->fd);
  81                         this->fd = -1;
  82                 }
  83         }
  84
  85         // establish an ident connection, maxtime is the time to spend trying
  86         // returns true if successful, false if something was catastrophically wrong.
  87         // note that failed connects are not reported here but detected in RFC1413::Poll()
  88         // as the socket is nonblocking
  89
  90         bool Connect(userrec* user, int maxtime)
  91         {
  92                 timeout_end = time(NULL)+maxtime;
  93                 timeout = false;
  94                 if ((this->fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
  95                 {
  96                         // theres been a boo-boo... no more fd's left for us, woe is me!
  97                         Srv->Log(DEBUG,"Ident: socket failed for: "+std::string(user->ip));
  98                         return false;
  99                 }
 100                 inet_aton(user->ip,&addy);
 101                 addr.sin_family = AF_INET;
 102                 addr.sin_addr = addy;
 103                 addr.sin_port = htons(113);
 104
 105                 int flags;
 106                 flags = fcntl(this->fd, F_GETFL, 0);
 107                 fcntl(this->fd, F_SETFL, flags | O_NONBLOCK);
 108
 109                 if(connect(this->fd, (sockaddr*)&this->addr,sizeof(this->addr)) == -1)
 110                 {
 111                         // theres been an error, but EINPROGRESS just means 'right, im on it, call me later'
 112                         if (errno != EINPROGRESS)
 113                         {
 114                                 // ... so that error isnt fatal, like the rest.
 115                                 Srv->Log(DEBUG,"Ident: connect failed for: "+std::string(user->ip));
 116                                 shutdown(this->fd,2);
 117                                 close(this->fd);
 118                                 this->fd = -1;
 119                                 return false;
 120                         }
 121                 }
 122                 Srv->Log(DEBUG,"Ident: successful connect associated with user "+std::string(user->nick));
 123                 this->u = user;
 124                 this->state = IDENT_STATE_CONNECT;
 125                 return true;
 126         }
 127
 128         // Poll the socket to see if we have an ident result, and if we do apply it to the user.
 129         // returns false if we cannot poll for some reason (e.g. timeout).
 130
 131         bool Poll()
 132         {
 133                 if (time(NULL) > timeout_end)
 134                 {
 135                         timeout = true;
 136                         Srv->SendServ(u->fd,"NOTICE "+std::string(u->nick)+" :*** Could not find your ident, using "+std::string(u->ident)+" instead.");
 137                         shutdown(this->fd,2);
 138                         close(this->fd);
 139                         this->fd = -1;
 140                         return false;
 141                 }
 142                 pollfd polls;
 143                 polls.fd = this->fd;
 144                 if (state == IDENT_STATE_CONNECT)
 145                 {
 146                         // during state IDENT_STATE_CONNECT (leading up to the connect)
 147                         // we're watching for writeability
 148                         polls.events = POLLOUT;
 149                 }
 150                 else
 151                 {
 152                         // the rest of the time we're waiting for data
 153                         // back on the socket, or a socket close
 154                         polls.events = POLLIN;
 155                 }
 156                 int ret = poll(&polls,1,1);
 157
 158                 if (ret > 0)
 159                 {
 160                         switch (this->state)
 161                         {
 162                                 case IDENT_STATE_CONNECT:
 163                                         uslen = sizeof(sock_us);
 164                                         themlen = sizeof(sock_them);
 165                                         if ((getsockname(this->u->fd,(sockaddr*)&sock_us,&uslen) || getpeername(this->u->fd, (sockaddr*)&sock_them, &themlen)))
 166                                         {
 167                                                 Srv->Log(DEBUG,"Ident: failed to get socket names, bailing to state 3");
 168                                                 shutdown(this->fd,2);
 169                                                 close(this->fd);
 170                                                 this->fd = -1;
 171                                                 state = IDENT_STATE_DONE;
 172                                         }
 173                                         else
 174                                         {
 175                                                 // send the request in the following format: theirsocket,oursocket
 176                                                 snprintf(ident_request,127,"%d,%d\r\n",ntohs(sock_them.sin_port),ntohs(sock_us.sin_port));
 177                                                 send(this->fd,ident_request,strlen(ident_request),0);
 178                                                 Srv->Log(DEBUG,"Sent ident request, moving to state 2");
 179                                                 state = IDENT_STATE_WAITDATA;
 180                                         }
 181                                 break;
 182                                 case IDENT_STATE_WAITDATA:
 183                                         nrecv = recv(this->fd,ibuf,sizeof(ibuf),0);
 184                                         if (nrecv > 0)
 185                                         {
 186                                                 // we have the response line in the following format:
 187                                                 // 6193, 23 : USERID : UNIX : stjohns
 188                                                 // 6195, 23 : ERROR : NO-USER
 189                                                 ibuf[nrecv] = '\0';
 190                                                 Srv->Log(DEBUG,"Received ident response: "+std::string(ibuf));
 191                                                 shutdown(this->fd,2);
 192                                                 close(this->fd);
 193                                                 this->fd = -1;
 194                                                 char* savept;
 195                                                 char* section = strtok_r(ibuf,":",&savept);
 196                                                 while (section)
 197                                                 {
 198                                                         if (strstr(section,"USERID"))
 199                                                         {
 200                                                                 section = strtok_r(NULL,":",&savept);
 201                                                                 if (section)
 202                                                                 {
 203                                                                         // ID type, usually UNIX or OTHER... we dont want it, so read the next token
 204                                                                         section = strtok_r(NULL,":",&savept);
 205                                                                         if (section)
 206                                                                         {
 207                                                                                 while ((*section == ' ') && (strlen(section)>0)) section++; // strip leading spaces
 208                                                                                 int t = strlen(section);
 209                                                                                 for (int j = 0; j < t; j++)
 210                                                                                         if ((section[j] < 33) || (section[j]>126))
 211                                                                                                 section[j] = '\0'; // truncate at invalid chars
 212                                                                                 if (strlen(section))
 213                                                                                 {
 214                                                                                         strlcpy(u->ident,section,IDENTMAX);
 215                                                                                         Srv->Log(DEBUG,"IDENT SET: "+std::string(u->ident));
 216                                                                                         Srv->SendServ(u->fd,"NOTICE "+std::string(u->nick)+" :*** Found your ident: "+std::string(u->ident));
 217                                                                                 }
 218                                                                                 break;
 219                                                                         }
 220                                                                 }
 221                                                         }
 222                                                         section = strtok_r(NULL,":",&savept);
 223                                                 }
 224                                                 state = IDENT_STATE_DONE;
 225                                         }
 226                                 break;
 227                                 case IDENT_STATE_DONE:
 228                                         shutdown(this->fd,2);
 229                                         close(this->fd);
 230                                         this->fd = -1;
 231                                         Srv->Log(DEBUG,"Ident lookup is complete!");
 232                                 break;
 233                                 default:
 234                                         Srv->Log(DEBUG,"Ident: invalid ident state!!!");
 235                                 break;
 236                         }
 237                 }
 238         }
 239
 240         // returns true if the operation is completed,
 241         // either due to complete request, or a timeout
 242
 243         bool Done()
 244         {
 245                 return ((state == IDENT_STATE_DONE) || (timeout == true));
 246         }
 247 };
 248
 249 class ModuleIdent : public Module
 250 {
 251
 252         ConfigReader* Conf;
 253         int IdentTimeout;
 254
 255  public:
 256         void ReadSettings()
 257         {
 258                 Conf = new ConfigReader;
 259                 IdentTimeout = Conf->ReadInteger("ident","timeout",0,true);
 260                 delete Conf;
 261         }
 262
 263         ModuleIdent()
 264         {
 265                 Srv = new Server;
 266                 ReadSettings();
 267         }
 268
 269         virtual void OnRehash()
 270         {
 271                 ReadSettings();
 272         }
 273
 274         virtual void OnUserRegister(userrec* user)
 275         {
 276                 // when the new user connects, before they authenticate with USER/NICK/PASS, we do
 277                 // their ident lookup.
 278
 279                 RFC1413* ident = new RFC1413;
 280                 Srv->SendServ(user->fd,"NOTICE "+std::string(user->nick)+" :*** Looking up your ident...");
 281                 if (ident->Connect(user,IdentTimeout))
 282                 {
 283                         // attach the object to the user record
 284                         user->Extend("ident_data",(char*)ident);
 285                         // start it off polling (always good to have a head start)
 286                         // because usually connect has completed by now
 287                         ident->Poll();
 288                 }
 289                 else
 290                 {
 291                         // something went wrong, call an irc-ambulance!
 292                         Srv->SendServ(user->fd,"NOTICE "+std::string(user->nick)+" :*** Could not look up your ident.");
 293                         delete ident;
 294                 }
 295         }
 296
 297         virtual bool OnCheckReady(userrec* user)
 298         {
 299                 RFC1413* ident = (RFC1413*)user->GetExt("ident_data");
 300                 if (ident)
 301                 {
 302                         // this user has a pending ident lookup, poll it
 303                         ident->Poll();
 304                         // is it done?
 305                         if (ident->Done())
 306                         {
 307                                 // their ident is done, zap the structures
 308                                 Srv->Log(DEBUG,"Ident: removing ident gubbins");
 309                                 user->Shrink("ident_data");
 310                                 delete ident;
 311                                 // ...and send them on their way
 312                                 return true;
 313                         }
 314                         // nope, we hold them in this state, they dont go anywhere
 315                         return false;
 316                 }
 317                 return true;
 318         }
 319
 320         virtual void OnUserDisconnect(userrec* user)
 321         {
 322                 // when the user quits tidy up any ident lookup they have pending to keep things tidy
 323                 // and to prevent a memory and FD leaks
 324                 RFC1413* ident = (RFC1413*)user->GetExt("ident_data");
 325                 if (ident)
 326                 {
 327                         delete ident;
 328                         user->Shrink("ident_data");
 329                 }
 330         }
 331
 332         virtual ~ModuleIdent()
 333         {
 334                 delete Srv;
 335         }
 336
 337         virtual Version GetVersion()
 338         {
 339                 return Version(1,0,0,1,VF_VENDOR);
 340         }
 341
 342 };
 343
 344 class ModuleIdentFactory : public ModuleFactory
 345 {
 346  public:
 347         ModuleIdentFactory()
 348         {
 349         }
 350
 351         ~ModuleIdentFactory()
 352         {
 353         }
 354
 355         virtual Module * CreateModule()
 356         {
 357                 return new ModuleIdent;
 358         }
 359
 360 };
 361
 362
 363 extern "C" void * init_module( void )
 364 {
 365         return new ModuleIdentFactory;
 366 }
 367