src/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
  26 #include "stdinc.h"
  27 #include "setup.h"
  28 #include "listener.h"
  29 #include "client.h"
  30 #include "match.h"
  31 #include "ircd.h"
  32 #include "ircd_defs.h"
  33 #include "numeric.h"
  34 #include "s_conf.h"
  35 #include "s_newconf.h"
  36 #include "s_stats.h"
  37 #include "send.h"
  38 #include "s_auth.h"
  39 #include "reject.h"
  40 #include "s_conf.h"
  41 #include "hostmask.h"
  42 #include "sslproc.h"
  43 #include "hash.h"
  44
  45 #ifndef INADDR_NONE
  46 #define INADDR_NONE ((unsigned int) 0xffffffff)
  47 #endif
  48
  49 #if defined(NO_IN6ADDR_ANY) && defined(RB_IPV6)
  50 static const struct in6_addr in6addr_any =
  51 { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } } };
  52 #endif
  53
  54 static struct Listener *ListenerPollList = NULL;
  55 static int accept_precallback(rb_fde_t *F, struct sockaddr *addr, rb_socklen_t addrlen, void *data);
  56 static void accept_callback(rb_fde_t *F, int status, struct sockaddr *addr, rb_socklen_t addrlen, void *data);
  57
  58 static struct Listener *
  59 make_listener(struct rb_sockaddr_storage *addr)
  60 {
  61         struct Listener *listener = (struct Listener *) rb_malloc(sizeof(struct Listener));
  62         s_assert(0 != listener);
  63         listener->name = me.name;
  64         listener->F = NULL;
  65
  66         memcpy(&listener->addr, addr, sizeof(struct rb_sockaddr_storage));
  67         listener->next = NULL;
  68         return listener;
  69 }
  70
  71 void
  72 free_listener(struct Listener *listener)
  73 {
  74         s_assert(NULL != listener);
  75         if(listener == NULL)
  76                 return;
  77         /*
  78          * remove from listener list
  79          */
  80         if(listener == ListenerPollList)
  81                 ListenerPollList = listener->next;
  82         else
  83         {
  84                 struct Listener *prev = ListenerPollList;
  85                 for (; prev; prev = prev->next)
  86                 {
  87                         if(listener == prev->next)
  88                         {
  89                                 prev->next = listener->next;
  90                                 break;
  91                         }
  92                 }
  93         }
  94
  95         /* free */
  96         rb_free(listener);
  97 }
  98
  99 #define PORTNAMELEN 6           /* ":31337" */
 100
 101 /*
 102  * get_listener_name - return displayable listener name and port
 103  * returns "host.foo.org:6667" for a given listener
 104  */
 105 const char *
 106 get_listener_name(const struct Listener *listener)
 107 {
 108         static char buf[HOSTLEN + HOSTLEN + PORTNAMELEN + 4];
 109         int port = 0;
 110
 111         s_assert(NULL != listener);
 112         if(listener == NULL)
 113                 return NULL;
 114
 115 #ifdef RB_IPV6
 116         if(listener->addr.ss_family == AF_INET6)
 117                 port = ntohs(((const struct sockaddr_in6 *)&listener->addr)->sin6_port);
 118         else
 119 #endif
 120                 port = ntohs(((const struct sockaddr_in *)&listener->addr)->sin_port);
 121
 122         rb_snprintf(buf, sizeof(buf), "%s[%s/%u]", me.name, listener->name, port);
 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 #ifdef RB_IPV6
 142                            ntohs(listener->addr.ss_family == AF_INET ? ((struct sockaddr_in *)&listener->addr)->sin_port :
 143                                  ((struct sockaddr_in6 *)&listener->addr)->sin6_port),
 144 #else
 145                            ntohs(((struct sockaddr_in *)&listener->addr)->sin_port),
 146 #endif
 147                            IsOperAdmin(source_p) ? listener->name : me.name,
 148                            listener->ref_count, (listener->active) ? "active" : "disabled",
 149                            listener->ssl ? " ssl" : "");
 150         }
 151 }
 152
 153 /*
 154  * inetport - create a listener socket in the AF_INET or AF_INET6 domain,
 155  * bind it to the port given in 'port' and listen to it
 156  * returns true (1) if successful false (0) on error.
 157  *
 158  * If the operating system has a define for SOMAXCONN, use it, otherwise
 159  * use RATBOX_SOMAXCONN
 160  */
 161 #ifdef SOMAXCONN
 162 #undef RATBOX_SOMAXCONN
 163 #define RATBOX_SOMAXCONN SOMAXCONN
 164 #endif
 165
 166 static int
 167 inetport(struct Listener *listener)
 168 {
 169         rb_fde_t *F;
 170         int opt = 1;
 171
 172         /*
 173          * At first, open a new socket
 174          */
 175
 176         F = rb_socket(GET_SS_FAMILY(&listener->addr), SOCK_STREAM, 0, "Listener socket");
 177
 178 #ifdef RB_IPV6
 179         if(listener->addr.ss_family == AF_INET6)
 180         {
 181                 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&listener->addr;
 182                 if(!IN6_ARE_ADDR_EQUAL(&in6->sin6_addr, &in6addr_any))
 183                 {
 184                         rb_inet_ntop(AF_INET6, &in6->sin6_addr, listener->vhost, sizeof(listener->vhost));
 185                         listener->name = listener->vhost;
 186                 }
 187         } else
 188 #endif
 189         {
 190                 struct sockaddr_in *in = (struct sockaddr_in *)&listener->addr;
 191                 if(in->sin_addr.s_addr != INADDR_ANY)
 192                 {
 193                         rb_inet_ntop(AF_INET, &in->sin_addr, listener->vhost, sizeof(listener->vhost));
 194                         listener->name = listener->vhost;
 195                 }
 196         }
 197
 198         if(F == NULL)
 199         {
 200                 ilog_error("opening listener socket");
 201                 return 0;
 202         }
 203         else if((maxconnections - 10) < rb_get_fd(F)) /* XXX this is kinda bogus*/
 204         {
 205                 ilog_error("no more connections left for listener");
 206                 rb_close(F);
 207                 return 0;
 208         }
 209
 210         /*
 211          * XXX - we don't want to do all this crap for a listener
 212          * set_sock_opts(listener);
 213          */
 214         if(setsockopt(rb_get_fd(F), SOL_SOCKET, SO_REUSEADDR, (char *) &opt, sizeof(opt)))
 215         {
 216                 ilog_error("setting SO_REUSEADDR for listener");
 217                 rb_close(F);
 218                 return 0;
 219         }
 220
 221         /*
 222          * Bind a port to listen for new connections if port is non-null,
 223          * else assume it is already open and try get something from it.
 224          */
 225
 226         if(bind(rb_get_fd(F), (struct sockaddr *) &listener->addr, GET_SS_LEN(&listener->addr)))
 227         {
 228                 ilog_error("binding listener socket");
 229                 rb_close(F);
 230                 return 0;
 231         }
 232
 233         if(rb_listen(F, RATBOX_SOMAXCONN))
 234         {
 235                 ilog_error("listen()");
 236                 rb_close(F);
 237                 return 0;
 238         }
 239
 240         listener->F = F;
 241
 242         rb_accept_tcp(listener->F, accept_precallback, accept_callback, listener);
 243         return 1;
 244 }
 245
 246 static struct Listener *
 247 find_listener(struct rb_sockaddr_storage *addr)
 248 {
 249         struct Listener *listener = NULL;
 250         struct Listener *last_closed = NULL;
 251
 252         for (listener = ListenerPollList; listener; listener = listener->next)
 253         {
 254                 if(addr->ss_family != listener->addr.ss_family)
 255                         continue;
 256
 257                 switch(addr->ss_family)
 258                 {
 259                         case AF_INET:
 260                         {
 261                                 struct sockaddr_in *in4 = (struct sockaddr_in *)addr;
 262                                 struct sockaddr_in *lin4 = (struct sockaddr_in *)&listener->addr;
 263                                 if(in4->sin_addr.s_addr == lin4->sin_addr.s_addr &&
 264                                         in4->sin_port == lin4->sin_port )
 265                                 {
 266                                         if(listener->F == NULL)
 267                                                 last_closed = listener;
 268                                         else
 269                                                 return(listener);
 270                                 }
 271                                 break;
 272                         }
 273 #ifdef RB_IPV6
 274                         case AF_INET6:
 275                         {
 276                                 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)addr;
 277                                 struct sockaddr_in6 *lin6 =(struct sockaddr_in6 *)&listener->addr;
 278                                 if(IN6_ARE_ADDR_EQUAL(&in6->sin6_addr, &lin6->sin6_addr) &&
 279                                   in6->sin6_port == lin6->sin6_port)
 280                                 {
 281                                         if(listener->F == NULL)
 282                                                 last_closed = listener;
 283                                         else
 284                                                 return(listener);
 285                                 }
 286                                 break;
 287
 288                         }
 289 #endif
 290
 291                         default:
 292                                 break;
 293                 }
 294         }
 295         return last_closed;
 296 }
 297
 298
 299 /*
 300  * add_listener- create a new listener
 301  * port - the port number to listen on
 302  * vhost_ip - if non-null must contain a valid IP address string in
 303  * the format "255.255.255.255"
 304  */
 305 void
 306 add_listener(int port, const char *vhost_ip, int family, int ssl)
 307 {
 308         struct Listener *listener;
 309         struct rb_sockaddr_storage vaddr;
 310
 311         /*
 312          * if no port in conf line, don't bother
 313          */
 314         if(port == 0)
 315                 return;
 316         memset(&vaddr, 0, sizeof(vaddr));
 317         vaddr.ss_family = family;
 318
 319         if(vhost_ip != NULL)
 320         {
 321                 if(family == AF_INET)
 322                 {
 323                         if(rb_inet_pton(family, vhost_ip, &((struct sockaddr_in *)&vaddr)->sin_addr) <= 0)
 324                                 return;
 325                 }
 326 #ifdef RB_IPV6
 327                 else
 328                 {
 329                         if(rb_inet_pton(family, vhost_ip, &((struct sockaddr_in6 *)&vaddr)->sin6_addr) <= 0)
 330                                 return;
 331
 332                 }
 333 #endif
 334         } else
 335         {
 336                 switch(family)
 337                 {
 338                         case AF_INET:
 339                                 ((struct sockaddr_in *)&vaddr)->sin_addr.s_addr = INADDR_ANY;
 340                                 break;
 341 #ifdef RB_IPV6
 342                         case AF_INET6:
 343                                 memcpy(&((struct sockaddr_in6 *)&vaddr)->sin6_addr, &in6addr_any, sizeof(struct in6_addr));
 344                                 break;
 345                         default:
 346                                 return;
 347 #endif
 348                 }
 349         }
 350         switch(family)
 351         {
 352                 case AF_INET:
 353                         SET_SS_LEN(&vaddr, sizeof(struct sockaddr_in));
 354                         ((struct sockaddr_in *)&vaddr)->sin_port = htons(port);
 355                         break;
 356 #ifdef RB_IPV6
 357                 case AF_INET6:
 358                         SET_SS_LEN(&vaddr, sizeof(struct sockaddr_in6));
 359                         ((struct sockaddr_in6 *)&vaddr)->sin6_port = htons(port);
 360                         break;
 361 #endif
 362                 default:
 363                         break;
 364         }
 365         if((listener = find_listener(&vaddr)))
 366         {
 367                 if(listener->F != NULL)
 368                         return;
 369         }
 370         else
 371         {
 372                 listener = make_listener(&vaddr);
 373                 listener->next = ListenerPollList;
 374                 ListenerPollList = listener;
 375         }
 376
 377         listener->F = NULL;
 378         listener->ssl = ssl;
 379
 380         if(inetport(listener))
 381                 listener->active = 1;
 382         else
 383                 close_listener(listener);
 384 }
 385
 386 /*
 387  * close_listener - close a single listener
 388  */
 389 void
 390 close_listener(struct Listener *listener)
 391 {
 392         s_assert(listener != NULL);
 393         if(listener == NULL)
 394                 return;
 395         if(listener->F != NULL)
 396         {
 397                 rb_close(listener->F);
 398                 listener->F = NULL;
 399         }
 400
 401         listener->active = 0;
 402
 403         if(listener->ref_count)
 404                 return;
 405
 406         free_listener(listener);
 407 }
 408
 409 /*
 410  * close_listeners - close and free all listeners that are not being used
 411  */
 412 void
 413 close_listeners()
 414 {
 415         struct Listener *listener;
 416         struct Listener *listener_next = 0;
 417         /*
 418          * close all 'extra' listening ports we have
 419          */
 420         for (listener = ListenerPollList; listener; listener = listener_next)
 421         {
 422                 listener_next = listener->next;
 423                 close_listener(listener);
 424         }
 425 }
 426
 427 #define DLINE_WARNING "ERROR :You have been D-lined.\r\n"
 428
 429 /*
 430  * add_connection - creates a client which has just connected to us on
 431  * the given fd. The sockhost field is initialized with the ip# of the host.
 432  * The client is sent to the auth module for verification, and not put in
 433  * any client list yet.
 434  */
 435 static void
 436 add_connection(struct Listener *listener, rb_fde_t *F, struct sockaddr *sai, struct sockaddr *lai, void *ssl_ctl)
 437 {
 438         struct Client *new_client;
 439         s_assert(NULL != listener);
 440
 441         /*
 442          * get the client socket name from the socket
 443          * the client has already been checked out in accept_connection
 444          */
 445         new_client = make_client(NULL);
 446
 447         memcpy(&new_client->localClient->ip, sai, sizeof(struct rb_sockaddr_storage));
 448         memcpy(&new_client->preClient->lip, lai, sizeof(struct rb_sockaddr_storage));
 449
 450         /*
 451          * copy address to 'sockhost' as a string, copy it to host too
 452          * so we have something valid to put into error messages...
 453          */
 454         rb_inet_ntop_sock((struct sockaddr *)&new_client->localClient->ip, new_client->sockhost,
 455                 sizeof(new_client->sockhost));
 456
 457
 458         rb_strlcpy(new_client->host, new_client->sockhost, sizeof(new_client->host));
 459
 460         new_client->localClient->F = F;
 461         add_to_cli_fd_hash(new_client);
 462         new_client->localClient->listener = listener;
 463         new_client->localClient->ssl_ctl = ssl_ctl;
 464         if(ssl_ctl != NULL || rb_fd_ssl(F))
 465                 SetSSL(new_client);
 466
 467         ++listener->ref_count;
 468
 469         start_auth(new_client);
 470 }
 471
 472 static const char *toofast = "ERROR :Reconnecting too fast, throttled.\r\n";
 473
 474 static int
 475 accept_precallback(rb_fde_t *F, struct sockaddr *addr, rb_socklen_t addrlen, void *data)
 476 {
 477         struct Listener *listener = (struct Listener *)data;
 478         char buf[BUFSIZE];
 479         struct ConfItem *aconf;
 480         static time_t last_oper_notice = 0;
 481         int len;
 482
 483         if(listener->ssl && (!ssl_ok || !get_ssld_count()))
 484         {
 485                 rb_close(F);
 486                 return 0;
 487         }
 488
 489         if((maxconnections - 10) < rb_get_fd(F)) /* XXX this is kinda bogus */
 490         {
 491                 ++ServerStats.is_ref;
 492                 /*
 493                  * slow down the whining to opers bit
 494                  */
 495                 if((last_oper_notice + 20) <= rb_current_time())
 496                 {
 497                         sendto_realops_snomask(SNO_GENERAL, L_ALL,
 498                                              "All connections in use. (%s)",
 499                                              get_listener_name(listener));
 500                         last_oper_notice = rb_current_time();
 501                 }
 502
 503                 rb_write(F, "ERROR :All connections in use\r\n", 32);
 504                 rb_close(F);
 505                 /* Re-register a new IO request for the next accept .. */
 506                 return 0;
 507         }
 508
 509         aconf = find_dline(addr, addr->sa_family);
 510         if(aconf != NULL && (aconf->status & CONF_EXEMPTDLINE))
 511                 return 1;
 512
 513         /* Do an initial check we aren't connecting too fast or with too many
 514          * from this IP... */
 515         if(aconf != NULL)
 516         {
 517                 ServerStats.is_ref++;
 518
 519                 if(ConfigFileEntry.dline_with_reason)
 520                 {
 521                         len = rb_snprintf(buf, sizeof(buf), "ERROR :*** Banned: %s\r\n", get_user_ban_reason(aconf));
 522                         if (len >= (int)(sizeof(buf)-1))
 523                         {
 524                                 buf[sizeof(buf) - 3] = '\r';
 525                                 buf[sizeof(buf) - 2] = '\n';
 526                                 buf[sizeof(buf) - 1] = '\0';
 527                         }
 528                 }
 529                 else
 530                         strcpy(buf, "ERROR :You have been D-lined.\r\n");
 531
 532                 rb_write(F, buf, strlen(buf));
 533                 rb_close(F);
 534                 return 0;
 535         }
 536
 537         if(check_reject(F, addr))
 538                 return 0;
 539
 540         if(throttle_add(addr))
 541         {
 542                 rb_write(F, toofast, strlen(toofast));
 543                 rb_close(F);
 544                 return 0;
 545         }
 546
 547         return 1;
 548 }
 549
 550 static void
 551 accept_ssld(rb_fde_t *F, struct sockaddr *addr, struct sockaddr *laddr, struct Listener *listener)
 552 {
 553         ssl_ctl_t *ctl;
 554         rb_fde_t *xF[2];
 555         if(rb_socketpair(AF_UNIX, SOCK_STREAM, 0, &xF[0], &xF[1], "Incoming ssld Connection") == -1)
 556         {
 557                 ilog_error("creating SSL/TLS socket pairs");
 558                 rb_close(F);
 559                 return;
 560         }
 561         ctl = start_ssld_accept(F, xF[1], rb_get_fd(xF[0])); /* this will close F for us */
 562         add_connection(listener, xF[0], addr, laddr, ctl);
 563 }
 564
 565 static void
 566 accept_callback(rb_fde_t *F, int status, struct sockaddr *addr, rb_socklen_t addrlen, void *data)
 567 {
 568         struct Listener *listener = data;
 569         struct rb_sockaddr_storage lip;
 570         unsigned int locallen = sizeof(struct rb_sockaddr_storage);
 571
 572         ServerStats.is_ac++;
 573
 574         if(getsockname(rb_get_fd(F), (struct sockaddr *) &lip, &locallen) < 0)
 575         {
 576                 /* this can fail if the connection disappeared in the meantime */
 577                 rb_close(F);
 578                 return;
 579         }
 580
 581         if(listener->ssl)
 582                 accept_ssld(F, addr, (struct sockaddr *)&lip, listener);
 583         else
 584                 add_connection(listener, F, addr, (struct sockaddr *)&lip, NULL);
 585 }