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  *  $Id: listener.c 1675 2006-06-15 22:32:23Z jilles $
  25  */
  26
  27 #include "stdinc.h"
  28 #include "setup.h"
  29 #include "listener.h"
  30 #include "client.h"
  31 #include "irc_string.h"
  32 #include "sprintf_irc.h"
  33 #include "ircd.h"
  34 #include "ircd_defs.h"
  35 #include "numeric.h"
  36 #include "commio.h"
  37 #include "s_conf.h"
  38 #include "s_newconf.h"
  39 #include "s_stats.h"
  40 #include "send.h"
  41 #include "memory.h"
  42 #include "s_auth.h"
  43 #include "reject.h"
  44
  45 #ifndef INADDR_NONE
  46 #define INADDR_NONE ((unsigned int) 0xffffffff)
  47 #endif
  48
  49 #if defined(NO_IN6ADDR_ANY) && defined(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 PF accept_connection;
  55
  56 static listener_t *ListenerPollList = NULL;
  57
  58 static listener_t *
  59 make_listener(struct irc_sockaddr_storage *addr)
  60 {
  61         listener_t *listener = (listener_t *) MyMalloc(sizeof(listener_t));
  62         s_assert(0 != listener);
  63
  64         listener->name = me.name;
  65         listener->fd = -1;
  66         memcpy(&listener->addr, addr, sizeof(struct irc_sockaddr_storage));
  67         listener->next = NULL;
  68         return listener;
  69 }
  70
  71 void
  72 free_listener(listener_t *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                 listener_t *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         MyFree(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 listener_t *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 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         ircsnprintf(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         listener_t *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 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         }
 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  * If the operating system has a define for SOMAXCONN, use it, otherwise
 158  * use RATBOX_SOMAXCONN
 159  */
 160 #ifdef SOMAXCONN
 161 #undef RATBOX_SOMAXCONN
 162 #define RATBOX_SOMAXCONN SOMAXCONN
 163 #endif
 164
 165 static int
 166 inetport(listener_t *listener)
 167 {
 168         int fd;
 169         int opt = 1;
 170
 171         /*
 172          * At first, open a new socket
 173          */
 174
 175         fd = comm_socket(listener->addr.ss_family, SOCK_STREAM, 0, "Listener socket");
 176
 177 #ifdef IPV6
 178         if(listener->addr.ss_family == 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                         inetntop(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                         inetntop(AF_INET, &in->sin_addr, listener->vhost, sizeof(listener->vhost));
 193                         listener->name = listener->vhost;
 194                 }
 195         }
 196
 197
 198         if(fd == -1)
 199         {
 200                 report_error("opening listener socket %s:%s",
 201                              get_listener_name(listener),
 202                              get_listener_name(listener), errno);
 203                 return 0;
 204         }
 205         else if((HARD_FDLIMIT - 10) < fd)
 206         {
 207                 report_error("no more connections left for listener %s:%s",
 208                              get_listener_name(listener),
 209                              get_listener_name(listener), errno);
 210                 comm_close(fd);
 211                 return 0;
 212         }
 213         /*
 214          * XXX - we don't want to do all this crap for a listener
 215          * set_sock_opts(listener);
 216          */
 217         if(setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *) &opt, sizeof(opt)))
 218         {
 219                 report_error("setting SO_REUSEADDR for listener %s:%s",
 220                              get_listener_name(listener),
 221                              get_listener_name(listener), errno);
 222                 comm_close(fd);
 223                 return 0;
 224         }
 225
 226         /*
 227          * Bind a port to listen for new connections if port is non-null,
 228          * else assume it is already open and try get something from it.
 229          */
 230
 231         if(bind(fd, (struct sockaddr *) &listener->addr, GET_SS_LEN(listener->addr)))
 232         {
 233                 report_error("binding listener socket %s:%s",
 234                              get_listener_name(listener),
 235                              get_listener_name(listener), errno);
 236                 comm_close(fd);
 237                 return 0;
 238         }
 239
 240         if(listen(fd, RATBOX_SOMAXCONN))
 241         {
 242                 report_error("listen failed for %s:%s",
 243                              get_listener_name(listener),
 244                              get_listener_name(listener), errno);
 245                 comm_close(fd);
 246                 return 0;
 247         }
 248
 249         listener->fd = fd;
 250
 251         /* Listen completion events are READ events .. */
 252
 253         accept_connection(fd, listener);
 254         return 1;
 255 }
 256
 257 static listener_t *
 258 find_listener(struct irc_sockaddr_storage *addr)
 259 {
 260         listener_t *listener = NULL;
 261         listener_t *last_closed = NULL;
 262
 263         for (listener = ListenerPollList; listener; listener = listener->next)
 264         {
 265                 if(addr->ss_family != listener->addr.ss_family)
 266                         continue;
 267
 268                 switch(addr->ss_family)
 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->fd == -1)
 278                                                 last_closed = listener;
 279                                         else
 280                                                 return(listener);
 281                                 }
 282                                 break;
 283                         }
 284 #ifdef 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->fd == -1)
 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)
 318 {
 319         listener_t *listener;
 320         struct irc_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         vaddr.ss_family = family;
 329
 330         if(vhost_ip != NULL)
 331         {
 332                 if(family == AF_INET)
 333                 {
 334                         if(inetpton(family, vhost_ip, &((struct sockaddr_in *)&vaddr)->sin_addr) <= 0)
 335                                 return;
 336                 }
 337 #ifdef IPV6
 338                 else
 339                 {
 340                         if(inetpton(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 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                         ((struct sockaddr_in *)&vaddr)->sin_port = htons(port);
 366                         break;
 367 #ifdef IPV6
 368                 case AF_INET6:
 369                         SET_SS_LEN(vaddr, sizeof(struct sockaddr_in6));
 370                         ((struct sockaddr_in6 *)&vaddr)->sin6_port = htons(port);
 371                         break;
 372 #endif
 373                 default:
 374                         break;
 375         }
 376         if((listener = find_listener(&vaddr)))
 377         {
 378                 if(listener->fd > -1)
 379                         return;
 380         }
 381         else
 382         {
 383                 listener = make_listener(&vaddr);
 384                 listener->next = ListenerPollList;
 385                 ListenerPollList = listener;
 386         }
 387
 388         listener->fd = -1;
 389
 390         if(inetport(listener))
 391                 listener->active = 1;
 392         else
 393                 close_listener(listener);
 394 }
 395
 396 /*
 397  * close_listener - close a single listener
 398  */
 399 void
 400 close_listener(listener_t *listener)
 401 {
 402         s_assert(listener != NULL);
 403         if(listener == NULL)
 404                 return;
 405         if(listener->fd >= 0)
 406         {
 407                 comm_close(listener->fd);
 408                 listener->fd = -1;
 409         }
 410
 411         listener->active = 0;
 412
 413         if(listener->ref_count)
 414                 return;
 415
 416         free_listener(listener);
 417 }
 418
 419 /*
 420  * close_listeners - close and free all listeners that are not being used
 421  */
 422 void
 423 close_listeners()
 424 {
 425         listener_t *listener;
 426         listener_t *listener_next = 0;
 427         /*
 428          * close all 'extra' listening ports we have
 429          */
 430         for (listener = ListenerPollList; listener; listener = listener_next)
 431         {
 432                 listener_next = listener->next;
 433                 close_listener(listener);
 434         }
 435 }
 436
 437 #define DLINE_WARNING "ERROR :You have been D-lined.\r\n"
 438
 439 /*
 440  * add_connection - creates a client which has just connected to us on
 441  * the given fd. The sockhost field is initialized with the ip# of the host.
 442  * The client is sent to the auth module for verification, and not put in
 443  * any client list yet.
 444  */
 445 static void
 446 add_connection(listener_t *listener, int fd, struct sockaddr *sai)
 447 {
 448         struct Client *new_client;
 449         s_assert(NULL != listener);
 450
 451         /*
 452          * get the client socket name from the socket
 453          * the client has already been checked out in accept_connection
 454          */
 455         new_client = make_client(NULL);
 456
 457         memcpy(&new_client->localClient->ip, sai, sizeof(struct irc_sockaddr_storage));
 458
 459         /*
 460          * copy address to 'sockhost' as a string, copy it to host too
 461          * so we have something valid to put into error messages...
 462          */
 463         inetntop_sock((struct sockaddr *)&new_client->localClient->ip, new_client->sockhost,
 464                 sizeof(new_client->sockhost));
 465
 466
 467         strlcpy(new_client->host, new_client->sockhost, sizeof(new_client->host));
 468
 469 #ifdef IPV6
 470         if(new_client->localClient->ip.ss_family == AF_INET6 && ConfigFileEntry.dot_in_ip6_addr == 1)
 471         {
 472                 strlcat(new_client->host, ".", sizeof(new_client->host));
 473         }
 474 #endif
 475
 476         new_client->localClient->fd = fd;
 477
 478         new_client->localClient->listener = listener;
 479         ++listener->ref_count;
 480
 481         if(check_reject(new_client))
 482                 return;
 483         start_auth(new_client);
 484 }
 485
 486
 487 static void
 488 accept_connection(int pfd, void *data)
 489 {
 490         static time_t last_oper_notice = 0;
 491
 492         struct irc_sockaddr_storage sai;
 493         socklen_t addrlen = sizeof(sai);
 494         int fd;
 495         listener_t *listener = data;
 496     struct ConfItem *aconf;
 497     char buf[BUFSIZE];
 498
 499         s_assert(listener != NULL);
 500         if(listener == NULL)
 501                 return;
 502         /*
 503          * There may be many reasons for error return, but
 504          * in otherwise correctly working environment the
 505          * probable cause is running out of file descriptors
 506          * (EMFILE, ENFILE or others?). The man pages for
 507          * accept don't seem to list these as possible,
 508          * although it's obvious that it may happen here.
 509          * Thus no specific errors are tested at this
 510          * point, just assume that connections cannot
 511          * be accepted until some old is closed first.
 512          */
 513
 514         fd = comm_accept(listener->fd, (struct sockaddr *)&sai, &addrlen);
 515         if(fd < 0)
 516         {
 517                 /* Re-register a new IO request for the next accept .. */
 518                 comm_setselect(listener->fd, FDLIST_SERVICE,
 519                                COMM_SELECT_READ, accept_connection, listener, 0);
 520                 return;
 521         }
 522
 523         /* This needs to be done here, otherwise we break dlines */
 524         mangle_mapped_sockaddr((struct sockaddr *)&sai);
 525
 526         /*
 527          * check for connection limit
 528          */
 529         if((MAXCONNECTIONS - 10) < fd)
 530         {
 531                 ++ServerStats->is_ref;
 532                 /*
 533                  * slow down the whining to opers bit
 534                  */
 535                 if((last_oper_notice + 20) <= CurrentTime)
 536                 {
 537                         sendto_realops_snomask(SNO_GENERAL, L_ALL,
 538                                              "All connections in use. (%s)",
 539                                              get_listener_name(listener));
 540                         last_oper_notice = CurrentTime;
 541                 }
 542
 543                 write(fd, "ERROR :All connections in use\r\n", 32);
 544                 comm_close(fd);
 545                 /* Re-register a new IO request for the next accept .. */
 546                 comm_setselect(listener->fd, FDLIST_SERVICE,
 547                                COMM_SELECT_READ, accept_connection, listener, 0);
 548                 return;
 549         }
 550
 551         /* Do an initial check we aren't connecting too fast or with too many
 552          * from this IP... */
 553         if((aconf = conf_connect_allowed((struct sockaddr *)&sai, sai.ss_family)) != NULL)
 554         {
 555                 ServerStats->is_ref++;
 556
 557         if(ConfigFileEntry.dline_with_reason)
 558         {
 559             if (ircsnprintf(buf, sizeof(buf), "ERROR :*** Banned: %s\r\n", aconf->passwd) >= (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            ircsprintf(buf, "ERROR :You have been D-lined.\r\n");
 568
 569         write(fd, buf, strlen(buf));
 570                 comm_close(fd);
 571
 572                 /* Re-register a new IO request for the next accept .. */
 573                 comm_setselect(listener->fd, FDLIST_SERVICE,
 574                                COMM_SELECT_READ, accept_connection, listener, 0);
 575                 return;
 576         }
 577
 578         ServerStats->is_ac++;
 579         add_connection(listener, fd, (struct sockaddr *)&sai);
 580
 581         /* Re-register a new IO request for the next accept .. */
 582         comm_setselect(listener->fd, FDLIST_SERVICE, COMM_SELECT_READ,
 583                        accept_connection, listener, 0);
 584 }