/* * ircd-ratbox: A slightly useful ircd. * listener.c: Listens on a port. * * Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center * Copyright (C) 1996-2002 Hybrid Development Team * Copyright (C) 2002-2005 ircd-ratbox development team * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 * USA * * $Id: listener.c 3460 2007-05-18 20:31:33Z jilles $ */ #include "stdinc.h" #include "setup.h" #include "listener.h" #include "client.h" #include "irc_string.h" #include "sprintf_irc.h" #include "ircd.h" #include "ircd_defs.h" #include "numeric.h" #include "s_conf.h" #include "s_newconf.h" #include "s_stats.h" #include "send.h" #include "s_auth.h" #include "reject.h" #include "s_conf.h" #include "hostmask.h" #ifndef INADDR_NONE #define INADDR_NONE ((unsigned int) 0xffffffff) #endif #if defined(NO_IN6ADDR_ANY) && defined(IPV6) static const struct in6_addr in6addr_any = { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } } }; #endif static PF accept_connection; static listener_t *ListenerPollList = NULL; static listener_t * make_listener(struct irc_sockaddr_storage *addr) { listener_t *listener = (listener_t *) rb_malloc(sizeof(listener_t)); s_assert(0 != listener); listener->name = me.name; listener->fd = -1; memcpy(&listener->addr, addr, sizeof(struct irc_sockaddr_storage)); listener->next = NULL; return listener; } void free_listener(listener_t *listener) { s_assert(NULL != listener); if(listener == NULL) return; /* * remove from listener list */ if(listener == ListenerPollList) ListenerPollList = listener->next; else { listener_t *prev = ListenerPollList; for (; prev; prev = prev->next) { if(listener == prev->next) { prev->next = listener->next; break; } } } /* free */ rb_free(listener); } #define PORTNAMELEN 6 /* ":31337" */ /* * get_listener_name - return displayable listener name and port * returns "host.foo.org:6667" for a given listener */ const char * get_listener_name(const listener_t *listener) { static char buf[HOSTLEN + HOSTLEN + PORTNAMELEN + 4]; int port = 0; s_assert(NULL != listener); if(listener == NULL) return NULL; #ifdef IPV6 if(listener->addr.ss_family == AF_INET6) port = ntohs(((const struct sockaddr_in6 *)&listener->addr)->sin6_port); else #endif port = ntohs(((const struct sockaddr_in *)&listener->addr)->sin_port); rb_snprintf(buf, sizeof(buf), "%s[%s/%u]", me.name, listener->name, port); return buf; } /* * show_ports - send port listing to a client * inputs - pointer to client to show ports to * output - none * side effects - show ports */ void show_ports(struct Client *source_p) { listener_t *listener = 0; for (listener = ListenerPollList; listener; listener = listener->next) { sendto_one_numeric(source_p, RPL_STATSPLINE, form_str(RPL_STATSPLINE), 'P', #ifdef IPV6 ntohs(listener->addr.ss_family == AF_INET ? ((struct sockaddr_in *)&listener->addr)->sin_port : ((struct sockaddr_in6 *)&listener->addr)->sin6_port), #else ntohs(((struct sockaddr_in *)&listener->addr)->sin_port), #endif IsOperAdmin(source_p) ? listener->name : me.name, listener->ref_count, (listener->active) ? "active" : "disabled"); } } /* * inetport - create a listener socket in the AF_INET or AF_INET6 domain, * bind it to the port given in 'port' and listen to it * returns true (1) if successful false (0) on error. * * If the operating system has a define for SOMAXCONN, use it, otherwise * use RATBOX_SOMAXCONN */ #ifdef SOMAXCONN #undef RATBOX_SOMAXCONN #define RATBOX_SOMAXCONN SOMAXCONN #endif static int inetport(listener_t *listener) { int fd; int opt = 1; /* * At first, open a new socket */ fd = rb_socket(listener->addr.ss_family, SOCK_STREAM, 0, "Listener socket"); #ifdef IPV6 if(listener->addr.ss_family == AF_INET6) { struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&listener->addr; if(!IN6_ARE_ADDR_EQUAL(&in6->sin6_addr, &in6addr_any)) { inetntop(AF_INET6, &in6->sin6_addr, listener->vhost, sizeof(listener->vhost)); listener->name = listener->vhost; } } else #endif { struct sockaddr_in *in = (struct sockaddr_in *)&listener->addr; if(in->sin_addr.s_addr != INADDR_ANY) { inetntop(AF_INET, &in->sin_addr, listener->vhost, sizeof(listener->vhost)); listener->name = listener->vhost; } } /* * At one point, we enforced a strange arbitrary limit here. * We no longer do this, and just check if the fd is valid or not. * -nenolod */ if(fd == -1) { report_error("opening listener socket %s:%s", get_listener_name(listener), get_listener_name(listener), errno); return 0; } /* * XXX - we don't want to do all this crap for a listener * set_sock_opts(listener); */ if(setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *) &opt, sizeof(opt))) { report_error("setting SO_REUSEADDR for listener %s:%s", get_listener_name(listener), get_listener_name(listener), errno); rb_close(fd); return 0; } /* * Bind a port to listen for new connections if port is non-null, * else assume it is already open and try get something from it. */ if(bind(fd, (struct sockaddr *) &listener->addr, GET_SS_LEN(listener->addr))) { report_error("binding listener socket %s:%s", get_listener_name(listener), get_listener_name(listener), errno); rb_close(fd); return 0; } if(listen(fd, RATBOX_SOMAXCONN)) { report_error("listen failed for %s:%s", get_listener_name(listener), get_listener_name(listener), errno); rb_close(fd); return 0; } listener->fd = fd; /* Listen completion events are READ events .. */ accept_connection(fd, listener); return 1; } static listener_t * find_listener(struct irc_sockaddr_storage *addr) { listener_t *listener = NULL; listener_t *last_closed = NULL; for (listener = ListenerPollList; listener; listener = listener->next) { if(addr->ss_family != listener->addr.ss_family) continue; switch(addr->ss_family) { case AF_INET: { struct sockaddr_in *in4 = (struct sockaddr_in *)addr; struct sockaddr_in *lin4 = (struct sockaddr_in *)&listener->addr; if(in4->sin_addr.s_addr == lin4->sin_addr.s_addr && in4->sin_port == lin4->sin_port ) { if(listener->fd == -1) last_closed = listener; else return(listener); } break; } #ifdef IPV6 case AF_INET6: { struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)addr; struct sockaddr_in6 *lin6 =(struct sockaddr_in6 *)&listener->addr; if(IN6_ARE_ADDR_EQUAL(&in6->sin6_addr, &lin6->sin6_addr) && in6->sin6_port == lin6->sin6_port) { if(listener->fd == -1) last_closed = listener; else return(listener); } break; } #endif default: break; } } return last_closed; } /* * add_listener- create a new listener * port - the port number to listen on * vhost_ip - if non-null must contain a valid IP address string in * the format "255.255.255.255" */ void add_listener(int port, const char *vhost_ip, int family) { listener_t *listener; struct irc_sockaddr_storage vaddr; /* * if no port in conf line, don't bother */ if(port == 0) return; memset(&vaddr, 0, sizeof(vaddr)); vaddr.ss_family = family; if(vhost_ip != NULL) { if(family == AF_INET) { if(inetpton(family, vhost_ip, &((struct sockaddr_in *)&vaddr)->sin_addr) <= 0) return; } #ifdef IPV6 else { if(inetpton(family, vhost_ip, &((struct sockaddr_in6 *)&vaddr)->sin6_addr) <= 0) return; } #endif } else { switch(family) { case AF_INET: ((struct sockaddr_in *)&vaddr)->sin_addr.s_addr = INADDR_ANY; break; #ifdef IPV6 case AF_INET6: memcpy(&((struct sockaddr_in6 *)&vaddr)->sin6_addr, &in6addr_any, sizeof(struct in6_addr)); break; default: return; #endif } } switch(family) { case AF_INET: SET_SS_LEN(vaddr, sizeof(struct sockaddr_in)); ((struct sockaddr_in *)&vaddr)->sin_port = htons(port); break; #ifdef IPV6 case AF_INET6: SET_SS_LEN(vaddr, sizeof(struct sockaddr_in6)); ((struct sockaddr_in6 *)&vaddr)->sin6_port = htons(port); break; #endif default: break; } if((listener = find_listener(&vaddr))) { if(listener->fd > -1) return; } else { listener = make_listener(&vaddr); listener->next = ListenerPollList; ListenerPollList = listener; } listener->fd = -1; if(inetport(listener)) listener->active = 1; else close_listener(listener); } /* * close_listener - close a single listener */ void close_listener(listener_t *listener) { s_assert(listener != NULL); if(listener == NULL) return; if(listener->fd >= 0) { rb_close(listener->fd); listener->fd = -1; } listener->active = 0; if(listener->ref_count) return; free_listener(listener); } /* * close_listeners - close and free all listeners that are not being used */ void close_listeners() { listener_t *listener; listener_t *listener_next = 0; /* * close all 'extra' listening ports we have */ for (listener = ListenerPollList; listener; listener = listener_next) { listener_next = listener->next; close_listener(listener); } } #define DLINE_WARNING "ERROR :You have been D-lined.\r\n" /* * add_connection - creates a client which has just connected to us on * the given fd. The sockhost field is initialized with the ip# of the host. * The client is sent to the auth module for verification, and not put in * any client list yet. */ static void add_connection(listener_t *listener, int fd, struct sockaddr *sai, int exempt) { struct Client *new_client; s_assert(NULL != listener); /* * get the client socket name from the socket * the client has already been checked out in accept_connection */ new_client = make_client(NULL); memcpy(&new_client->localClient->ip, sai, sizeof(struct irc_sockaddr_storage)); /* * copy address to 'sockhost' as a string, copy it to host too * so we have something valid to put into error messages... */ inetntop_sock((struct sockaddr *)&new_client->localClient->ip, new_client->sockhost, sizeof(new_client->sockhost)); strlcpy(new_client->host, new_client->sockhost, sizeof(new_client->host)); new_client->localClient->F = rb_add_fd(fd); new_client->localClient->listener = listener; ++listener->ref_count; if(!exempt) { if(check_reject(new_client)) return; if(add_unknown_ip(new_client)) return; } start_auth(new_client); } static void accept_connection(int pfd, void *data) { static time_t last_oper_notice = 0; struct irc_sockaddr_storage sai; socklen_t addrlen = sizeof(sai); int fd; listener_t *listener = data; struct ConfItem *aconf; char buf[BUFSIZE]; s_assert(listener != NULL); if(listener == NULL) return; /* * There may be many reasons for error return, but * in otherwise correctly working environment the * probable cause is running out of file descriptors * (EMFILE, ENFILE or others?). The man pages for * accept don't seem to list these as possible, * although it's obvious that it may happen here. * Thus no specific errors are tested at this * point, just assume that connections cannot * be accepted until some old is closed first. */ fd = rb_accept(listener->fd, (struct sockaddr *)&sai, &addrlen); if(fd < 0) { /* Re-register a new IO request for the next accept .. */ rb_setselect(listener->fd, FDLIST_SERVICE, COMM_SELECT_READ, accept_connection, listener, 0); return; } /* This needs to be done here, otherwise we break dlines */ mangle_mapped_sockaddr((struct sockaddr *)&sai); /* * check for connection limit * TBD: this is stupid... either we have a socket or we don't. -nenolod */ if((rb_get_maxconnections() - 10) < fd) { ++ServerStats->is_ref; /* * slow down the whining to opers bit */ if((last_oper_notice + 20) <= rb_current_time()) { sendto_realops_snomask(SNO_GENERAL, L_ALL, "All connections in use. (%s)", get_listener_name(listener)); last_oper_notice = rb_current_time(); } write(fd, "ERROR :All connections in use\r\n", 32); rb_close(fd); /* Re-register a new IO request for the next accept .. */ rb_setselect(listener->fd, FDLIST_SERVICE, COMM_SELECT_READ, accept_connection, listener, 0); return; } /* Do an initial check we aren't connecting too fast or with too many * from this IP... */ aconf = find_dline((struct sockaddr *) &sai, sai.ss_family); /* check it wasn't an exempt */ if (aconf != NULL && (aconf->status & CONF_EXEMPTDLINE) == 0) { ServerStats->is_ref++; if(ConfigFileEntry.dline_with_reason) { if (rb_snprintf(buf, sizeof(buf), "ERROR :*** Banned: %s\r\n", aconf->passwd) >= (sizeof(buf)-1)) { buf[sizeof(buf) - 3] = '\r'; buf[sizeof(buf) - 2] = '\n'; buf[sizeof(buf) - 1] = '\0'; } } else rb_sprintf(buf, "ERROR :You have been D-lined.\r\n"); write(fd, buf, strlen(buf)); rb_close(fd); /* Re-register a new IO request for the next accept .. */ rb_setselect(listener->fd, FDLIST_SERVICE, COMM_SELECT_READ, accept_connection, listener, 0); return; } ServerStats->is_ac++; add_connection(listener, fd, (struct sockaddr *)&sai, aconf ? 1 : 0); /* Re-register a new IO request for the next accept .. */ rb_setselect(listener->fd, FDLIST_SERVICE, COMM_SELECT_READ, accept_connection, listener, 0); }