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