ircd/listener.c

   1 /*
   2  *  ircd-ratbox: A slightly useful ircd.
   3  *  listener.c: Listens on a port.
   4  *
   5  *  Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center
   6  *  Copyright (C) 1996-2002 Hybrid Development Team
   7  *  Copyright (C) 2002-2005 ircd-ratbox development team
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or
  12  *  (at your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program; if not, write to the Free Software
  21  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
  22  *  USA
  23  */
  24
  25 #include "stdinc.h"
  26 #include "setup.h"
  27 #include "listener.h"
  28 #include "client.h"
  29 #include "match.h"
  30 #include "ircd.h"
  31 #include "ircd_defs.h"
  32 #include "numeric.h"
  33 #include "s_conf.h"
  34 #include "s_newconf.h"
  35 #include "s_stats.h"
  36 #include "send.h"
  37 #include "authproc.h"
  38 #include "reject.h"
  39 #include "hostmask.h"
  40 #include "sslproc.h"
  41 #include "wsproc.h"
  42 #include "hash.h"
  43 #include "s_assert.h"
  44 #include "logger.h"
  45
  46 #if defined(NO_IN6ADDR_ANY) && defined(RB_IPV6)
  47 static const struct in6_addr in6addr_any =
  48 { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } } };
  49 #endif
  50
  51 static struct Listener *ListenerPollList = NULL;
  52 static int accept_precallback(rb_fde_t *F, struct sockaddr *addr, rb_socklen_t addrlen, void *data);
  53 static void accept_callback(rb_fde_t *F, int status, struct sockaddr *addr, rb_socklen_t addrlen, void *data);
  54 static SSL_OPEN_CB accept_sslcallback;
  55
  56 static struct Listener *
  57 make_listener(struct rb_sockaddr_storage *addr)
  58 {
  59         struct Listener *listener = (struct Listener *) rb_malloc(sizeof(struct Listener));
  60         s_assert(0 != listener);
  61         listener->name = me.name;
  62         listener->F = NULL;
  63
  64         memcpy(&listener->addr, addr, sizeof(struct rb_sockaddr_storage));
  65         listener->next = NULL;
  66         return listener;
  67 }
  68
  69 void
  70 free_listener(struct Listener *listener)
  71 {
  72         s_assert(NULL != listener);
  73         if(listener == NULL)
  74                 return;
  75         /*
  76          * remove from listener list
  77          */
  78         if(listener == ListenerPollList)
  79                 ListenerPollList = listener->next;
  80         else
  81         {
  82                 struct Listener *prev = ListenerPollList;
  83                 for (; prev; prev = prev->next)
  84                 {
  85                         if(listener == prev->next)
  86                         {
  87                                 prev->next = listener->next;
  88                                 break;
  89                         }
  90                 }
  91         }
  92
  93         /* free */
  94         rb_free(listener);
  95 }
  96
  97 #define PORTNAMELEN 6           /* ":31337" */
  98
  99 /*
 100  * get_listener_port - return displayable listener port
 101  */
 102 static uint16_t
 103 get_listener_port(const struct Listener *listener)
 104 {
 105         return ntohs(GET_SS_PORT(&listener->addr));
 106 }
 107
 108 /*
 109  * get_listener_name - return displayable listener name and port
 110  * returns "host.foo.org:6667" for a given listener
 111  */
 112 const char *
 113 get_listener_name(const struct Listener *listener)
 114 {
 115         static char buf[HOSTLEN + HOSTLEN + PORTNAMELEN + 4];
 116
 117         s_assert(NULL != listener);
 118         if(listener == NULL)
 119                 return NULL;
 120
 121         snprintf(buf, sizeof(buf), "%s[%s/%u]",
 122                         me.name, listener->name, get_listener_port(listener));
 123         return buf;
 124 }
 125
 126 /*
 127  * show_ports - send port listing to a client
 128  * inputs       - pointer to client to show ports to
 129  * output       - none
 130  * side effects - show ports
 131  */
 132 void
 133 show_ports(struct Client *source_p)
 134 {
 135         struct Listener *listener = 0;
 136
 137         for (listener = ListenerPollList; listener; listener = listener->next)
 138         {
 139                 sendto_one_numeric(source_p, RPL_STATSPLINE,
 140                            form_str(RPL_STATSPLINE), 'P',
 141                            get_listener_port(listener),
 142                            IsOperAdmin(source_p) ? listener->name : me.name,
 143                            listener->ref_count, (listener->active) ? "active" : "disabled",
 144                            listener->ssl ? " ssl" : "");
 145         }
 146 }
 147
 148 /*
 149  * inetport - create a listener socket in the AF_INET or AF_INET6 domain,
 150  * bind it to the port given in 'port' and listen to it
 151  * returns true (1) if successful false (0) on error.
 152  */
 153
 154 static int
 155 inetport(struct Listener *listener)
 156 {
 157         rb_fde_t *F;
 158         int opt = 1;
 159         const char *errstr;
 160
 161         /*
 162          * At first, open a new socket
 163          */
 164
 165         F = rb_socket(GET_SS_FAMILY(&listener->addr), SOCK_STREAM, 0, "Listener socket");
 166
 167 #ifdef RB_IPV6
 168         if(GET_SS_FAMILY(&listener->addr) == AF_INET6)
 169         {
 170                 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&listener->addr;
 171                 if(!IN6_ARE_ADDR_EQUAL(&in6->sin6_addr, &in6addr_any))
 172                 {
 173                         rb_inet_ntop(AF_INET6, &in6->sin6_addr, listener->vhost, sizeof(listener->vhost));
 174                         listener->name = listener->vhost;
 175                 }
 176         } else
 177 #endif
 178         {
 179                 struct sockaddr_in *in = (struct sockaddr_in *)&listener->addr;
 180                 if(in->sin_addr.s_addr != INADDR_ANY)
 181                 {
 182                         rb_inet_ntop(AF_INET, &in->sin_addr, listener->vhost, sizeof(listener->vhost));
 183                         listener->name = listener->vhost;
 184                 }
 185         }
 186
 187         if(F == NULL)
 188         {
 189                 sendto_realops_snomask(SNO_GENERAL, L_ALL,
 190                                 "Cannot open socket for listener on port %d",
 191                                 get_listener_port(listener));
 192                 ilog(L_MAIN, "Cannot open socket for listener %s",
 193                                 get_listener_name(listener));
 194                 return 0;
 195         }
 196         else if((maxconnections - 10) < rb_get_fd(F)) /* XXX this is kinda bogus*/
 197         {
 198                 ilog_error("no more connections left for listener");
 199                 sendto_realops_snomask(SNO_GENERAL, L_ALL,
 200                                 "No more connections left for listener on port %d",
 201                                 get_listener_port(listener));
 202                 ilog(L_MAIN, "No more connections left for listener %s",
 203                                 get_listener_name(listener));
 204                 rb_close(F);
 205                 return 0;
 206         }
 207
 208         /*
 209          * XXX - we don't want to do all this crap for a listener
 210          * set_sock_opts(listener);
 211          *
 212          * FIXME - doesn't this belong in librb? --Elizafox
 213          */
 214         if(setsockopt(rb_get_fd(F), SOL_SOCKET, SO_REUSEADDR, (char *) &opt, sizeof(opt)))
 215         {
 216                 errstr = strerror(rb_get_sockerr(F));
 217                 sendto_realops_snomask(SNO_GENERAL, L_ALL,
 218                                 "Cannot set SO_REUSEADDR for listener on port %d: %s",
 219                                 get_listener_port(listener), errstr);
 220                 ilog(L_MAIN, "Cannot set SO_REUSEADDR for listener %s: %s",
 221                                 get_listener_name(listener), errstr);
 222                 rb_close(F);
 223                 return 0;
 224         }
 225
 226         /* FIXME - doesn't this belong in librb? --Elizafox */
 227         if(bind(rb_get_fd(F), (struct sockaddr *) &listener->addr, GET_SS_LEN(&listener->addr)))
 228         {
 229                 errstr = strerror(rb_get_sockerr(F));
 230                 sendto_realops_snomask(SNO_GENERAL, L_ALL,
 231                                 "Cannot bind for listener on port %d: %s",
 232                                 get_listener_port(listener), errstr);
 233                 ilog(L_MAIN, "Cannot bind for listener %s: %s",
 234                                 get_listener_name(listener), errstr);
 235                 rb_close(F);
 236                 return 0;
 237         }
 238
 239         if(rb_listen(F, SOMAXCONN, listener->defer_accept))
 240         {
 241                 errstr = strerror(rb_get_sockerr(F));
 242                 sendto_realops_snomask(SNO_GENERAL, L_ALL,
 243                                 "Cannot listen() for listener on port %d: %s",
 244                                 get_listener_port(listener), errstr);
 245                 ilog(L_MAIN, "Cannot listen() for listener %s: %s",
 246                                 get_listener_name(listener), errstr);
 247                 rb_close(F);
 248                 return 0;
 249         }
 250
 251         listener->F = F;
 252
 253         rb_accept_tcp(listener->F, accept_precallback, accept_callback, listener);
 254         return 1;
 255 }
 256
 257 static struct Listener *
 258 find_listener(struct rb_sockaddr_storage *addr)
 259 {
 260         struct Listener *listener = NULL;
 261         struct Listener *last_closed = NULL;
 262
 263         for (listener = ListenerPollList; listener; listener = listener->next)
 264         {
 265                 if(GET_SS_FAMILY(addr) != GET_SS_FAMILY(&listener->addr))
 266                         continue;
 267
 268                 switch(GET_SS_FAMILY(addr))
 269                 {
 270                         case AF_INET:
 271                         {
 272                                 struct sockaddr_in *in4 = (struct sockaddr_in *)addr;
 273                                 struct sockaddr_in *lin4 = (struct sockaddr_in *)&listener->addr;
 274                                 if(in4->sin_addr.s_addr == lin4->sin_addr.s_addr &&
 275                                         in4->sin_port == lin4->sin_port )
 276                                 {
 277                                         if(listener->F == NULL)
 278                                                 last_closed = listener;
 279                                         else
 280                                                 return(listener);
 281                                 }
 282                                 break;
 283                         }
 284 #ifdef RB_IPV6
 285                         case AF_INET6:
 286                         {
 287                                 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)addr;
 288                                 struct sockaddr_in6 *lin6 =(struct sockaddr_in6 *)&listener->addr;
 289                                 if(IN6_ARE_ADDR_EQUAL(&in6->sin6_addr, &lin6->sin6_addr) &&
 290                                   in6->sin6_port == lin6->sin6_port)
 291                                 {
 292                                         if(listener->F == NULL)
 293                                                 last_closed = listener;
 294                                         else
 295                                                 return(listener);
 296                                 }
 297                                 break;
 298
 299                         }
 300 #endif
 301
 302                         default:
 303                                 break;
 304                 }
 305         }
 306         return last_closed;
 307 }
 308
 309
 310 /*
 311  * add_listener- create a new listener
 312  * port - the port number to listen on
 313  * vhost_ip - if non-null must contain a valid IP address string in
 314  * the format "255.255.255.255"
 315  */
 316 void
 317 add_listener(int port, const char *vhost_ip, int family, int ssl, int defer_accept, int wsock)
 318 {
 319         struct Listener *listener;
 320         struct rb_sockaddr_storage vaddr;
 321
 322         /*
 323          * if no port in conf line, don't bother
 324          */
 325         if(port == 0)
 326                 return;
 327         memset(&vaddr, 0, sizeof(vaddr));
 328         SET_SS_FAMILY(&vaddr, family);
 329
 330         if(vhost_ip != NULL)
 331         {
 332                 if(family == AF_INET)
 333                 {
 334                         if(rb_inet_pton(family, vhost_ip, &((struct sockaddr_in *)&vaddr)->sin_addr) <= 0)
 335                                 return;
 336                 }
 337 #ifdef RB_IPV6
 338                 else
 339                 {
 340                         if(rb_inet_pton(family, vhost_ip, &((struct sockaddr_in6 *)&vaddr)->sin6_addr) <= 0)
 341                                 return;
 342
 343                 }
 344 #endif
 345         } else
 346         {
 347                 switch(family)
 348                 {
 349                         case AF_INET:
 350                                 ((struct sockaddr_in *)&vaddr)->sin_addr.s_addr = INADDR_ANY;
 351                                 break;
 352 #ifdef RB_IPV6
 353                         case AF_INET6:
 354                                 memcpy(&((struct sockaddr_in6 *)&vaddr)->sin6_addr, &in6addr_any, sizeof(struct in6_addr));
 355                                 break;
 356                         default:
 357                                 return;
 358 #endif
 359                 }
 360         }
 361         switch(family)
 362         {
 363                 case AF_INET:
 364                         SET_SS_LEN(&vaddr, sizeof(struct sockaddr_in));
 365                         SET_SS_FAMILY(&vaddr, AF_INET);
 366                         SET_SS_PORT(&vaddr, htons(port));
 367                         break;
 368 #ifdef RB_IPV6
 369                 case AF_INET6:
 370                         SET_SS_LEN(&vaddr, sizeof(struct sockaddr_in6));
 371                         SET_SS_FAMILY(&vaddr, AF_INET6);
 372                         SET_SS_PORT(&vaddr, htons(port));
 373                         break;
 374 #endif
 375                 default:
 376                         break;
 377         }
 378         if((listener = find_listener(&vaddr)))
 379         {
 380                 if(listener->F != NULL)
 381                         return;
 382         }
 383         else
 384         {
 385                 listener = make_listener(&vaddr);
 386                 listener->next = ListenerPollList;
 387                 ListenerPollList = listener;
 388         }
 389
 390         listener->F = NULL;
 391         listener->ssl = ssl;
 392         listener->defer_accept = defer_accept;
 393         listener->wsock = wsock;
 394
 395         if(inetport(listener))
 396                 listener->active = 1;
 397         else
 398                 close_listener(listener);
 399 }
 400
 401 /*
 402  * close_listener - close a single listener
 403  */
 404 void
 405 close_listener(struct Listener *listener)
 406 {
 407         s_assert(listener != NULL);
 408         if(listener == NULL)
 409                 return;
 410         if(listener->F != NULL)
 411         {
 412                 rb_close(listener->F);
 413                 listener->F = NULL;
 414         }
 415
 416         listener->active = 0;
 417
 418         if(listener->ref_count)
 419                 return;
 420
 421         free_listener(listener);
 422 }
 423
 424 /*
 425  * close_listeners - close and free all listeners that are not being used
 426  */
 427 void
 428 close_listeners()
 429 {
 430         struct Listener *listener;
 431         struct Listener *listener_next = 0;
 432         /*
 433          * close all 'extra' listening ports we have
 434          */
 435         for (listener = ListenerPollList; listener; listener = listener_next)
 436         {
 437                 listener_next = listener->next;
 438                 close_listener(listener);
 439         }
 440 }
 441
 442 /*
 443  * add_connection - creates a client which has just connected to us on
 444  * the given fd. The sockhost field is initialized with the ip# of the host.
 445  * The client is sent to the auth module for verification, and not put in
 446  * any client list yet.
 447  */
 448 static void
 449 add_connection(struct Listener *listener, rb_fde_t *F, struct sockaddr *sai, struct sockaddr *lai)
 450 {
 451         struct Client *new_client;
 452         bool defer = false;
 453         s_assert(NULL != listener);
 454
 455         /*
 456          * get the client socket name from the socket
 457          * the client has already been checked out in accept_connection
 458          */
 459         new_client = make_client(NULL);
 460
 461         if (listener->ssl)
 462         {
 463                 rb_fde_t *xF[2];
 464                 if(rb_socketpair(AF_UNIX, SOCK_STREAM, 0, &xF[0], &xF[1], "Incoming ssld Connection") == -1)
 465                 {
 466                         free_client(new_client);
 467                         return;
 468                 }
 469                 new_client->localClient->ssl_callback = accept_sslcallback;
 470                 defer = true;
 471                 new_client->localClient->ssl_ctl = start_ssld_accept(F, xF[1], connid_get(new_client));        /* this will close F for us */
 472                 if(new_client->localClient->ssl_ctl == NULL)
 473                 {
 474                         free_client(new_client);
 475                         return;
 476                 }
 477                 F = xF[0];
 478                 SetSSL(new_client);
 479         }
 480
 481         if (listener->wsock)
 482         {
 483                 rb_fde_t *xF[2];
 484                 if(rb_socketpair(AF_UNIX, SOCK_STREAM, 0, &xF[0], &xF[1], "Incoming wsockd Connection") == -1)
 485                 {
 486                         free_client(new_client);
 487                         return;
 488                 }
 489                 new_client->localClient->ws_ctl = start_wsockd_accept(F, xF[1], connid_get(new_client));        /* this will close F for us */
 490                 if(new_client->localClient->ws_ctl == NULL)
 491                 {
 492                         free_client(new_client);
 493                         return;
 494                 }
 495                 F = xF[0];
 496         }
 497
 498         memcpy(&new_client->localClient->ip, sai, sizeof(struct rb_sockaddr_storage));
 499         memcpy(&new_client->preClient->lip, lai, sizeof(struct rb_sockaddr_storage));
 500
 501         /*
 502          * copy address to 'sockhost' as a string, copy it to host too
 503          * so we have something valid to put into error messages...
 504          */
 505         rb_inet_ntop_sock((struct sockaddr *)&new_client->localClient->ip, new_client->sockhost,
 506                 sizeof(new_client->sockhost));
 507
 508
 509         rb_strlcpy(new_client->host, new_client->sockhost, sizeof(new_client->host));
 510
 511         new_client->localClient->F = F;
 512         new_client->localClient->listener = listener;
 513
 514         ++listener->ref_count;
 515
 516         authd_initiate_client(new_client, defer);
 517 }
 518
 519 static int
 520 accept_sslcallback(struct Client *client_p, int status)
 521 {
 522         authd_deferred_client(client_p);
 523         return 0; /* use default handler if status != RB_OK */
 524 }
 525
 526 static const char *toofast = "ERROR :Reconnecting too fast, throttled.\r\n";
 527
 528 static int
 529 accept_precallback(rb_fde_t *F, struct sockaddr *addr, rb_socklen_t addrlen, void *data)
 530 {
 531         struct Listener *listener = (struct Listener *)data;
 532         char buf[BUFSIZE];
 533         struct ConfItem *aconf;
 534         static time_t last_oper_notice = 0;
 535         int len;
 536
 537         if(listener->ssl && (!ircd_ssl_ok || !get_ssld_count()))
 538         {
 539                 rb_close(F);
 540                 return 0;
 541         }
 542
 543         if((maxconnections - 10) < rb_get_fd(F)) /* XXX this is kinda bogus */
 544         {
 545                 ++ServerStats.is_ref;
 546                 /*
 547                  * slow down the whining to opers bit
 548                  */
 549                 if((last_oper_notice + 20) <= rb_current_time())
 550                 {
 551                         sendto_realops_snomask(SNO_GENERAL, L_ALL,
 552                                              "All connections in use. (%s)",
 553                                              get_listener_name(listener));
 554                         last_oper_notice = rb_current_time();
 555                 }
 556
 557                 rb_write(F, "ERROR :All connections in use\r\n", 31);
 558                 rb_close(F);
 559                 return 0;
 560         }
 561
 562         aconf = find_dline(addr, addr->sa_family);
 563         if(aconf != NULL && (aconf->status & CONF_EXEMPTDLINE))
 564                 return 1;
 565
 566         /* Do an initial check we aren't connecting too fast or with too many
 567          * from this IP... */
 568         if(aconf != NULL)
 569         {
 570                 ServerStats.is_ref++;
 571
 572                 if(ConfigFileEntry.dline_with_reason)
 573                 {
 574                         len = snprintf(buf, sizeof(buf), "ERROR :*** Banned: %s\r\n", get_user_ban_reason(aconf));
 575                         if (len >= (int)(sizeof(buf)-1))
 576                         {
 577                                 buf[sizeof(buf) - 3] = '\r';
 578                                 buf[sizeof(buf) - 2] = '\n';
 579                                 buf[sizeof(buf) - 1] = '\0';
 580                         }
 581                 }
 582                 else
 583                         strcpy(buf, "ERROR :You have been D-lined.\r\n");
 584
 585                 rb_write(F, buf, strlen(buf));
 586                 rb_close(F);
 587                 return 0;
 588         }
 589
 590         if(check_reject(F, addr))
 591                 return 0;
 592
 593         if(throttle_add(addr))
 594         {
 595                 rb_write(F, toofast, strlen(toofast));
 596                 rb_close(F);
 597                 return 0;
 598         }
 599
 600         return 1;
 601 }
 602
 603 static void
 604 accept_callback(rb_fde_t *F, int status, struct sockaddr *addr, rb_socklen_t addrlen, void *data)
 605 {
 606         struct Listener *listener = data;
 607         struct rb_sockaddr_storage lip;
 608         unsigned int locallen = sizeof(struct rb_sockaddr_storage);
 609
 610         ServerStats.is_ac++;
 611
 612         if(getsockname(rb_get_fd(F), (struct sockaddr *) &lip, &locallen) < 0)
 613         {
 614                 /* this can fail if the connection disappeared in the meantime */
 615                 rb_close(F);
 616                 return;
 617         }
 618
 619         add_connection(listener, F, addr, (struct sockaddr *)&lip);
 620 }