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