/* * 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 * Copyright (C) 2021 Ariadne Conill * * 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 */ #include "stdinc.h" #include "setup.h" #include "listener.h" #include "client.h" #include "match.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 "authproc.h" #include "reject.h" #include "hostmask.h" #include "sslproc.h" #include "wsproc.h" #include "hash.h" #include "s_assert.h" #include "logger.h" static rb_dlink_list listener_list = {}; static int accept_precallback(rb_fde_t *F, struct sockaddr *addr, rb_socklen_t addrlen, void *data); static void accept_callback(rb_fde_t *F, int status, struct sockaddr *addr, rb_socklen_t addrlen, void *data); static SSL_OPEN_CB accept_sslcallback; static struct Listener * make_listener(struct rb_sockaddr_storage *addr) { struct Listener *listener = (struct Listener *) rb_malloc(sizeof(struct Listener)); s_assert(0 != listener); listener->name = me.name; listener->F = NULL; memcpy(&listener->addr, addr, sizeof(listener->addr)); return listener; } void free_listener(struct Listener *listener) { s_assert(NULL != listener); if(listener == NULL) return; rb_dlinkDelete(&listener->lnode, &listener_list); rb_free(listener); } #define PORTNAMELEN 6 /* ":31337" */ /* * get_listener_port - return displayable listener port */ static uint16_t get_listener_port(const struct Listener *listener) { return ntohs(GET_SS_PORT(&listener->addr[0])); } /* * get_listener_name - return displayable listener name and port */ const char * get_listener_name(const struct Listener *listener) { static char buf[BUFSIZE]; snprintf(buf, sizeof(buf), "%s[%s/%u]", me.name, listener->name, get_listener_port(listener)); 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) { rb_dlink_node *n; RB_DLINK_FOREACH(n, listener_list.head) { struct Listener *listener = n->data; sendto_one_numeric(source_p, RPL_STATSPLINE, form_str(RPL_STATSPLINE), 'P', get_listener_port(listener), IsOperAdmin(source_p) ? listener->name : me.name, listener->ref_count, (listener->active) ? "active" : "disabled", listener->sctp ? " sctp" : " tcp", listener->ssl ? " ssl" : ""); } } /* * 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. */ static int inetport(struct Listener *listener) { rb_fde_t *F; const char *errstr; int ret; if (listener->sctp) { #ifdef HAVE_LIBSCTP /* only AF_INET6 sockets can have both AF_INET and AF_INET6 addresses */ F = rb_socket(AF_INET6, SOCK_STREAM, IPPROTO_SCTP, "Listener socket"); #else F = NULL; #endif } else { F = rb_socket(GET_SS_FAMILY(&listener->addr[0]), SOCK_STREAM, IPPROTO_TCP, "Listener socket"); } memset(listener->vhost, 0, sizeof(listener->vhost)); if (GET_SS_FAMILY(&listener->addr[0]) == AF_INET6) { struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&listener->addr[0]; rb_inet_ntop(AF_INET6, &in6->sin6_addr, listener->vhost, sizeof(listener->vhost)); } else if (GET_SS_FAMILY(&listener->addr[0]) == AF_INET) { struct sockaddr_in *in = (struct sockaddr_in *)&listener->addr[0]; rb_inet_ntop(AF_INET, &in->sin_addr, listener->vhost, sizeof(listener->vhost)); } if (GET_SS_FAMILY(&listener->addr[1]) == AF_INET6) { struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&listener->addr[1]; strncat(listener->vhost, "&", sizeof(listener->vhost)); rb_inet_ntop(AF_INET6, &in6->sin6_addr, &listener->vhost[strlen(listener->vhost)], sizeof(listener->vhost) - strlen(listener->vhost)); } else if (GET_SS_FAMILY(&listener->addr[1]) == AF_INET) { struct sockaddr_in *in = (struct sockaddr_in *)&listener->addr[1]; strncat(listener->vhost, "&", sizeof(listener->vhost)); rb_inet_ntop(AF_INET, &in->sin_addr, &listener->vhost[strlen(listener->vhost)], sizeof(listener->vhost) - strlen(listener->vhost)); } if (listener->vhost[0] != '\0') { listener->name = listener->vhost; } if (F == NULL) { sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, "Cannot open socket for listener on %s port %d", listener->sctp ? "SCTP" : "TCP", get_listener_port(listener)); ilog(L_MAIN, "Cannot open socket for %s listener %s", listener->sctp ? "SCTP" : "TCP", get_listener_name(listener)); return 0; } if (listener->sctp) { ret = rb_sctp_bindx(F, listener->addr, ARRAY_SIZE(listener->addr)); } else { ret = rb_bind(F, (struct sockaddr *)&listener->addr[0]); } if (ret) { errstr = strerror(rb_get_sockerr(F)); sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, "Cannot bind for listener on %s port %d: %s", listener->sctp ? "SCTP" : "TCP", get_listener_port(listener), errstr); ilog(L_MAIN, "Cannot bind for %s listener %s: %s", listener->sctp ? "SCTP" : "TCP", get_listener_name(listener), errstr); rb_close(F); return 0; } if(rb_listen(F, SOMAXCONN, listener->defer_accept)) { errstr = strerror(rb_get_sockerr(F)); sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, "Cannot listen() for listener on %s port %d: %s", listener->sctp ? "SCTP" : "TCP", get_listener_port(listener), errstr); ilog(L_MAIN, "Cannot listen() for %s listener %s: %s", listener->sctp ? "SCTP" : "TCP", get_listener_name(listener), errstr); rb_close(F); return 0; } listener->F = F; rb_accept_tcp(listener->F, accept_precallback, accept_callback, listener); return 1; } static struct Listener * find_listener(struct rb_sockaddr_storage *addr, int sctp) { rb_dlink_node *n; struct Listener *last_closed = NULL; RB_DLINK_FOREACH(n, listener_list.head) { struct Listener *listener = n->data; if (listener->sctp != sctp) continue; for (int i = 0; i < ARRAY_SIZE(listener->addr); i++) { if (GET_SS_FAMILY(&addr[i]) != GET_SS_FAMILY(&listener->addr[i])) goto next; switch (GET_SS_FAMILY(&addr[i])) { case AF_INET: { struct sockaddr_in *in4 = (struct sockaddr_in *)&addr[i]; struct sockaddr_in *lin4 = (struct sockaddr_in *)&listener->addr[i]; if(in4->sin_addr.s_addr != lin4->sin_addr.s_addr || in4->sin_port != lin4->sin_port) { goto next; } break; } case AF_INET6: { struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&addr[i]; struct sockaddr_in6 *lin6 =(struct sockaddr_in6 *)&listener->addr[i]; if (!IN6_ARE_ADDR_EQUAL(&in6->sin6_addr, &lin6->sin6_addr) || in6->sin6_port != lin6->sin6_port) { goto next; } break; } default: break; } } if (listener->F == NULL) { last_closed = listener; } else { return listener; } next: continue; } return last_closed; } /* * add_tcp_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_tcp_listener(int port, const char *vhost_ip, int family, int ssl, int defer_accept, int wsock) { struct Listener *listener; struct rb_sockaddr_storage vaddr[ARRAY_SIZE(listener->addr)]; /* * if no port in conf line, don't bother */ if (port == 0) return; memset(&vaddr, 0, sizeof(vaddr)); SET_SS_FAMILY(&vaddr[0], AF_UNSPEC); SET_SS_LEN(&vaddr[0], sizeof(struct sockaddr_storage)); SET_SS_FAMILY(&vaddr[1], AF_UNSPEC); SET_SS_LEN(&vaddr[1], sizeof(struct sockaddr_storage)); if (vhost_ip != NULL) { if (family == AF_INET) { if (rb_inet_pton(family, vhost_ip, &((struct sockaddr_in *)&vaddr[0])->sin_addr) <= 0) return; } else { if (rb_inet_pton(family, vhost_ip, &((struct sockaddr_in6 *)&vaddr[0])->sin6_addr) <= 0) return; } } else { switch(family) { case AF_INET: ((struct sockaddr_in *)&vaddr[0])->sin_addr.s_addr = INADDR_ANY; break; case AF_INET6: memcpy(&((struct sockaddr_in6 *)&vaddr[0])->sin6_addr, &in6addr_any, sizeof(struct in6_addr)); break; default: return; } } switch(family) { case AF_INET: SET_SS_LEN(&vaddr[0], sizeof(struct sockaddr_in)); SET_SS_FAMILY(&vaddr[0], AF_INET); SET_SS_PORT(&vaddr[0], htons(port)); break; case AF_INET6: SET_SS_LEN(&vaddr[0], sizeof(struct sockaddr_in6)); SET_SS_FAMILY(&vaddr[0], AF_INET6); SET_SS_PORT(&vaddr[0], htons(port)); break; default: break; } if ((listener = find_listener(vaddr, 0))) { if (listener->F != NULL) return; } else { listener = make_listener(vaddr); rb_dlinkAdd(listener, &listener->lnode, &listener_list); } listener->F = NULL; listener->ssl = ssl; listener->defer_accept = defer_accept; listener->sctp = 0; listener->wsock = wsock; if (inetport(listener)) { listener->active = 1; } else { close_listener(listener); } } /* * add_sctp_listener- create a new listener * port - the port number to listen on * vhost_ip1/2 - if non-null must contain a valid IP address string */ void add_sctp_listener(int port, const char *vhost_ip1, const char *vhost_ip2, int ssl, int wsock) { struct Listener *listener; struct rb_sockaddr_storage vaddr[ARRAY_SIZE(listener->addr)]; /* * if no port in conf line, don't bother */ if (port == 0) return; memset(&vaddr, 0, sizeof(vaddr)); if (vhost_ip1 != NULL) { if (rb_inet_pton_sock(vhost_ip1, &vaddr[0]) <= 0) return; if (vhost_ip2 != NULL) { if (rb_inet_pton_sock(vhost_ip2, &vaddr[1]) <= 0) return; } else { SET_SS_FAMILY(&vaddr[1], AF_UNSPEC); SET_SS_LEN(&vaddr[1], sizeof(struct sockaddr_storage)); } if (GET_SS_FAMILY(&vaddr[0]) == AF_INET && GET_SS_FAMILY(&vaddr[1]) == AF_INET6) { /* always put INET6 first */ struct rb_sockaddr_storage tmp; tmp = vaddr[0]; vaddr[0] = vaddr[1]; vaddr[1] = tmp; } } else { memcpy(&((struct sockaddr_in6 *)&vaddr[0])->sin6_addr, &in6addr_any, sizeof(struct in6_addr)); SET_SS_FAMILY(&vaddr[0], AF_INET6); SET_SS_LEN(&vaddr[0], sizeof(struct sockaddr_in6)); SET_SS_FAMILY(&vaddr[1], AF_UNSPEC); SET_SS_LEN(&vaddr[1], sizeof(struct sockaddr_storage)); } SET_SS_PORT(&vaddr[0], htons(port)); SET_SS_PORT(&vaddr[1], htons(port)); if ((listener = find_listener(vaddr, 1))) { if(listener->F != NULL) return; } else { listener = make_listener(vaddr); rb_dlinkAdd(listener, &listener->lnode, &listener_list); } listener->F = NULL; listener->ssl = ssl; listener->defer_accept = 0; listener->sctp = 1; listener->wsock = wsock; if (inetport(listener)) { listener->active = 1; } else { close_listener(listener); } } /* * close_listener - close a single listener */ void close_listener(struct Listener *listener) { s_assert(listener != NULL); if(listener == NULL) return; if(listener->F != NULL) { rb_close(listener->F); listener->F = NULL; } 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(void) { rb_dlink_node *n, *tn; /* * close all 'extra' listening ports we have */ RB_DLINK_FOREACH_SAFE(n, tn, listener_list.head) { struct Listener *listener = n->data; close_listener(listener); } rb_close_pending_fds(); } /* * 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(struct Listener *listener, rb_fde_t *F, struct sockaddr *sai, struct sockaddr *lai) { struct Client *new_client; bool defer = false; 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); new_client->localClient->F = F; memcpy(&new_client->localClient->ip, sai, sizeof(struct rb_sockaddr_storage)); memcpy(&new_client->preClient->lip, lai, sizeof(struct rb_sockaddr_storage)); /* * copy address to 'sockhost' as a string, copy it to host too * so we have something valid to put into error messages... */ rb_inet_ntop_sock((struct sockaddr *)&new_client->localClient->ip, new_client->sockhost, sizeof(new_client->sockhost)); rb_strlcpy(new_client->host, new_client->sockhost, sizeof(new_client->host)); if (listener->sctp) { SetSCTP(new_client); } if (listener->ssl) { rb_fde_t *xF[2]; if(rb_socketpair(AF_UNIX, SOCK_STREAM, 0, &xF[0], &xF[1], "Incoming ssld Connection") == -1) { SetIOError(new_client); exit_client(new_client, new_client, new_client, "Fatal Error"); return; } new_client->localClient->ssl_callback = accept_sslcallback; defer = true; new_client->localClient->ssl_ctl = start_ssld_accept(F, xF[1], connid_get(new_client)); /* this will close F for us */ if(new_client->localClient->ssl_ctl == NULL) { SetIOError(new_client); exit_client(new_client, new_client, new_client, "Service Unavailable"); return; } F = xF[0]; new_client->localClient->F = F; SetSSL(new_client); SetSecure(new_client); } else { struct ConfItem *aconf; aconf = find_conf_by_address(NULL, NULL, NULL, sai, CONF_SECURE | 1, sai->sa_family, NULL, NULL); if (aconf != NULL) SetSecure(new_client); } if (listener->wsock) { rb_fde_t *xF[2]; if(rb_socketpair(AF_UNIX, SOCK_STREAM, 0, &xF[0], &xF[1], "Incoming wsockd Connection") == -1) { SetIOError(new_client); exit_client(new_client, new_client, new_client, "Fatal Error"); return; } new_client->localClient->ws_ctl = start_wsockd_accept(F, xF[1], connid_get(new_client)); /* this will close F for us */ if(new_client->localClient->ws_ctl == NULL) { SetIOError(new_client); exit_client(new_client, new_client, new_client, "Service Unavailable"); return; } F = xF[0]; new_client->localClient->F = F; } new_client->localClient->listener = listener; ++listener->ref_count; authd_initiate_client(new_client, defer); } static int accept_sslcallback(struct Client *client_p, int status) { authd_deferred_client(client_p); return 0; /* use default handler if status != RB_OK */ } static int accept_precallback(rb_fde_t *F, struct sockaddr *addr, rb_socklen_t addrlen, void *data) { struct Listener *listener = (struct Listener *)data; char buf[BUFSIZE]; struct ConfItem *aconf; static time_t last_oper_notice = 0; int len; static const char *allinuse = "ERROR :All connections in use\r\n"; static const char *toofast = "ERROR :Reconnecting too fast, throttled.\r\n"; static const unsigned char ssldeniederrcode[] = { // SSLv3.0 Fatal Alert: Access Denied 0x15, 0x03, 0x00, 0x00, 0x02, 0x02, 0x31 }; static const unsigned char sslinternalerrcode[] = { // SSLv3.0 Fatal Alert: Internal Error 0x15, 0x03, 0x00, 0x00, 0x02, 0x02, 0x50 }; if(listener->ssl && (!ircd_ssl_ok || !get_ssld_count())) { rb_close(F); return 0; } if((maxconnections - 10) < rb_get_fd(F)) /* XXX this is kinda bogus */ { ++ServerStats.is_ref; /* * slow down the whining to opers bit */ if((last_oper_notice + 20) <= rb_current_time()) { sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, "All connections in use. (%s)", get_listener_name(listener)); last_oper_notice = rb_current_time(); } if(listener->ssl) rb_write(F, sslinternalerrcode, sizeof(sslinternalerrcode)); else rb_write(F, allinuse, strlen(allinuse)); rb_close(F); return 0; } aconf = find_dline(addr, addr->sa_family); if(aconf != NULL && (aconf->status & CONF_EXEMPTDLINE)) return 1; /* Do an initial check we aren't connecting too fast or with too many * from this IP... */ if(aconf != NULL) { ServerStats.is_ref++; if(listener->ssl) { rb_write(F, ssldeniederrcode, sizeof(ssldeniederrcode)); } else if(ConfigFileEntry.dline_with_reason) { len = snprintf(buf, sizeof(buf), "ERROR :*** Banned: %s\r\n", get_user_ban_reason(aconf)); if (len >= (int)(sizeof(buf)-1)) { buf[sizeof(buf) - 3] = '\r'; buf[sizeof(buf) - 2] = '\n'; buf[sizeof(buf) - 1] = '\0'; } rb_write(F, buf, strlen(buf)); } else { strcpy(buf, "ERROR :You have been D-lined.\r\n"); rb_write(F, buf, strlen(buf)); } rb_close(F); return 0; } if(check_reject(F, addr, listener->ssl)) { /* Reject the connection without closing the socket * because it is now on the delay_exit list. */ return 0; } if(throttle_add(addr)) { if(listener->ssl) rb_write(F, ssldeniederrcode, sizeof(ssldeniederrcode)); else rb_write(F, toofast, strlen(toofast)); rb_close(F); return 0; } return 1; } static void accept_callback(rb_fde_t *F, int status, struct sockaddr *addr, rb_socklen_t addrlen, void *data) { struct Listener *listener = data; struct rb_sockaddr_storage lip; unsigned int locallen = sizeof(struct rb_sockaddr_storage); ServerStats.is_ac++; if(getsockname(rb_get_fd(F), (struct sockaddr *) &lip, &locallen) < 0) { /* this can fail if the connection disappeared in the meantime */ rb_close(F); return; } add_connection(listener, F, addr, (struct sockaddr *)&lip); }