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