--- /dev/null
+/************************************************************************
+ * IRC - Internet Relay Chat, src/listener.c
+ * Copyright (C) 1999 Thomas Helvey <tomh@inxpress.net>
+ *
+ * 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 1, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+/** @file
+ * @brief Implementation for handling listening sockets.
+ * @version $Id$
+ */
+#include "config.h"
+
+#include "listener.h"
+#include "client.h"
+#include "ircd.h"
+#include "ircd_alloc.h"
+#include "ircd_events.h"
+#include "ircd_features.h"
+#include "ircd_log.h"
+#include "ircd_osdep.h"
+#include "ircd_reply.h"
+#include "ircd_snprintf.h"
+#include "ircd_string.h"
+#include "match.h"
+#include "numeric.h"
+#include "s_bsd.h"
+#include "s_conf.h"
+#include "s_misc.h"
+#include "s_stats.h"
+#include "send.h"
+#include "sys.h" /* MAXCLIENTS */
+
+/* #include <assert.h> -- Now using assert in ircd_log.h */
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <netdb.h>
+#include <sys/socket.h>
+
+/** List of listening sockets. */
+struct Listener* ListenerPollList = 0;
+
+static void accept_connection(struct Event* ev);
+
+/** Allocate and initialize a new Listener structure for a particular
+ * socket address.
+ * @param[in] port Port number to listen on.
+ * @param[in] addr Local address to listen on.
+ * @return Newly allocated and initialized Listener.
+ */
+static struct Listener* make_listener(int port, const struct irc_in_addr *addr)
+{
+ struct Listener* listener =
+ (struct Listener*) MyMalloc(sizeof(struct Listener));
+ assert(0 != listener);
+
+ memset(listener, 0, sizeof(struct Listener));
+
+ listener->fd_v4 = -1;
+ listener->fd_v6 = -1;
+ listener->addr.port = port;
+ memcpy(&listener->addr.addr, addr, sizeof(listener->addr.addr));
+
+#ifdef NULL_POINTER_NOT_ZERO
+ listener->next = NULL;
+ listener->conf = NULL;
+#endif
+ return listener;
+}
+
+/** Deallocate a Listener structure.
+ * @param[in] listener Listener to be freed.
+ */
+static void free_listener(struct Listener* listener)
+{
+ assert(0 != listener);
+ MyFree(listener);
+}
+
+/** Maximum length for a port number. */
+#define PORTNAMELEN 10 /* ":31337" */
+
+/** Return displayable listener name and port.
+ * @param[in] listener %Listener to format as a text string.
+ * @return Pointer to a static buffer that contains "server.name:6667".
+ */
+const char* get_listener_name(const struct Listener* listener)
+{
+ static char buf[HOSTLEN + PORTNAMELEN + 4];
+ assert(0 != listener);
+ ircd_snprintf(0, buf, sizeof(buf), "%s:%u", cli_name(&me), listener->addr.port);
+ return buf;
+}
+
+/** Count allocated listeners and the memory they use.
+ * @param[out] count_out Receives number of allocated listeners.
+ * @param[out] size_out Receives bytes used by listeners.
+ */
+void count_listener_memory(int* count_out, size_t* size_out)
+{
+ struct Listener* l;
+ int count = 0;
+ assert(0 != count_out);
+ assert(0 != size_out);
+ for (l = ListenerPollList; l; l = l->next)
+ ++count;
+ *count_out = count;
+ *size_out = count * sizeof(struct Listener);
+}
+
+/** Report listening ports to a client.
+ * @param[in] sptr Client requesting statistics.
+ * @param[in] sd Stats descriptor for request (ignored).
+ * @param[in] param Extra parameter from user (port number to search for).
+ */
+void show_ports(struct Client* sptr, const struct StatDesc* sd,
+ char* param)
+{
+ struct Listener *listener = 0;
+ char flags[8];
+ int show_hidden = IsOper(sptr);
+ int count = (IsOper(sptr) || MyUser(sptr)) ? 100 : 8;
+ int port = 0;
+ int len;
+
+ assert(0 != sptr);
+
+ if (param)
+ port = atoi(param);
+
+ for (listener = ListenerPollList; listener; listener = listener->next) {
+ if (port && port != listener->addr.port)
+ continue;
+ len = 0;
+ flags[len++] = listener_server(listener) ? 'S' : 'C';
+ if (FlagHas(&listener->flags, LISTEN_HIDDEN))
+ {
+ if (!show_hidden)
+ continue;
+ flags[len++] = 'H';
+ }
+ if (FlagHas(&listener->flags, LISTEN_IPV4))
+ {
+ flags[len++] = '4';
+ if (listener->fd_v4 < 0)
+ flags[len++] = '-';
+ }
+ if (FlagHas(&listener->flags, LISTEN_IPV6))
+ {
+ flags[len++] = '6';
+ if (listener->fd_v6 < 0)
+ flags[len++] = '-';
+ }
+ flags[len] = '\0';
+
+ send_reply(sptr, RPL_STATSPLINE, listener->addr.port, listener->ref_count,
+ flags, listener_active(listener) ? "active" : "disabled");
+ if (--count == 0)
+ break;
+ }
+}
+
+/*
+ * inetport - create a listener socket in the AF_INET 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 HYBRID_SOMAXCONN -Dianora
+ * NOTE: Do this in os_xxxx.c files
+ */
+#ifdef SOMAXCONN
+#define HYBRID_SOMAXCONN SOMAXCONN
+#else
+/** Maximum length of socket connection backlog. */
+#define HYBRID_SOMAXCONN 64
+#endif
+
+/** Set or update socket options for \a listener.
+ * @param[in] listener Listener to determine socket option values.
+ * @param[in] fd File descriptor being updated.
+ * @return Non-zero on success, zero on failure.
+ */
+static int set_listener_options(struct Listener *listener, int fd)
+{
+ int is_server;
+
+ is_server = listener_server(listener);
+ /*
+ * Set the buffer sizes for the listener. Accepted connections
+ * inherit the accepting sockets settings for SO_RCVBUF S_SNDBUF
+ * The window size is set during the SYN ACK so setting it anywhere
+ * else has no effect whatsoever on the connection.
+ * NOTE: this must be set before listen is called
+ */
+ if (!os_set_sockbufs(fd,
+ is_server ? feature_int(FEAT_SOCKSENDBUF) : CLIENT_TCP_WINDOW,
+ is_server ? feature_int(FEAT_SOCKRECVBUF) : CLIENT_TCP_WINDOW)) {
+ report_error(SETBUFS_ERROR_MSG, get_listener_name(listener), errno);
+ close(fd);
+ return 0;
+ }
+
+ /*
+ * Set the TOS bits - this is nonfatal if it doesn't stick.
+ */
+ if (!os_set_tos(fd,feature_int(is_server ? FEAT_TOS_SERVER : FEAT_TOS_CLIENT))) {
+ report_error(TOS_ERROR_MSG, get_listener_name(listener), errno);
+ }
+
+ return 1;
+}
+
+/** Open listening socket for \a listener.
+ * @param[in,out] listener Listener to make a socket for.
+ * @param[in] family Socket address family to use.
+ * @return Negative on failure, file descriptor on success.
+ */
+static int inetport(struct Listener* listener, int family)
+{
+ struct Socket *sock;
+ int fd;
+
+ /*
+ * At first, open a new socket
+ */
+ fd = os_socket(&listener->addr, SOCK_STREAM, get_listener_name(listener), family);
+ if (fd < 0)
+ return -1;
+ if (!os_set_listen(fd, HYBRID_SOMAXCONN)) {
+ report_error(LISTEN_ERROR_MSG, get_listener_name(listener), errno);
+ close(fd);
+ return -1;
+ }
+ if (!set_listener_options(listener, fd))
+ return -1;
+ sock = (family == AF_INET) ? &listener->socket_v4 : &listener->socket_v6;
+ if (!socket_add(sock, accept_connection, (void*) listener,
+ SS_LISTENING, 0, fd)) {
+ /* Error should already have been reported to the logs */
+ close(fd);
+ return -1;
+ }
+
+ return fd;
+}
+
+/** Find the listener (if any) for a particular port and address.
+ * @param[in] port Port number to search for.
+ * @param[in] addr Local address to search for.
+ * @return Listener that matches (or NULL if none match).
+ */
+static struct Listener* find_listener(int port, const struct irc_in_addr *addr)
+{
+ struct Listener* listener;
+ for (listener = ListenerPollList; listener; listener = listener->next) {
+ if (port == listener->addr.port && !memcmp(addr, &listener->addr.addr, sizeof(*addr)))
+ return listener;
+ }
+ return 0;
+}
+
+/** Make sure we have a listener for \a port on \a vhost_ip.
+ * If one does not exist, create it. Then mark it as active and set
+ * the peer mask, server, and hidden flags according to the other
+ * arguments.
+ * @param[in] port Port number to listen on.
+ * @param[in] vhost_ip Local address to listen on.
+ * @param[in] mask Address mask to accept connections from.
+ * @param[in] flags Flags describing listener options.
+ */
+void add_listener(int port, const char* vhost_ip, const char* mask,
+ const struct ListenerFlags *flags)
+{
+ struct Listener* listener;
+ struct irc_in_addr vaddr;
+ int okay = 0;
+ int new_listener = 0;
+ int fd;
+
+ /*
+ * if no port in conf line, don't bother
+ */
+ if (0 == port)
+ return;
+
+ memset(&vaddr, 0, sizeof(vaddr));
+
+ if (!EmptyString(vhost_ip)
+ && strcmp(vhost_ip, "*")
+ && !ircd_aton(&vaddr, vhost_ip))
+ return;
+
+ listener = find_listener(port, &vaddr);
+ if (!listener)
+ {
+ new_listener = 1;
+ listener = make_listener(port, &vaddr);
+ }
+ memcpy(&listener->flags, flags, sizeof(listener->flags));
+ FlagSet(&listener->flags, LISTEN_ACTIVE);
+ if (mask)
+ ipmask_parse(mask, &listener->mask, &listener->mask_bits);
+ else
+ listener->mask_bits = 0;
+
+#ifdef IPV6
+ if (FlagHas(&listener->flags, LISTEN_IPV6)
+ && (irc_in_addr_unspec(&vaddr) || !irc_in_addr_is_ipv4(&vaddr))) {
+ if (listener->fd_v6 >= 0) {
+ set_listener_options(listener, listener->fd_v6);
+ okay = 1;
+ } else if ((fd = inetport(listener, AF_INET6)) >= 0) {
+ listener->fd_v6 = fd;
+ okay = 1;
+ }
+ } else if (-1 < listener->fd_v6) {
+ close(listener->fd_v6);
+ socket_del(&listener->socket_v6);
+ listener->fd_v6 = -1;
+ }
+#endif
+
+ if (FlagHas(&listener->flags, LISTEN_IPV4)
+ && (irc_in_addr_unspec(&vaddr) || irc_in_addr_is_ipv4(&vaddr))) {
+ if (listener->fd_v4 >= 0) {
+ set_listener_options(listener, listener->fd_v4);
+ okay = 1;
+ } else if ((fd = inetport(listener, AF_INET)) >= 0) {
+ listener->fd_v4 = fd;
+ okay = 1;
+ }
+ } else if (-1 < listener->fd_v4) {
+ close(listener->fd_v4);
+ socket_del(&listener->socket_v4);
+ listener->fd_v4 = -1;
+ }
+
+ if (!okay)
+ free_listener(listener);
+ else if (new_listener) {
+ listener->next = ListenerPollList;
+ ListenerPollList = listener;
+ }
+}
+
+/** Mark all listeners as closing (inactive).
+ * This is done so unused listeners are closed after a rehash.
+ */
+void mark_listeners_closing(void)
+{
+ struct Listener* listener;
+ for (listener = ListenerPollList; listener; listener = listener->next)
+ FlagClr(&listener->flags, LISTEN_ACTIVE);
+}
+
+/** Close a single listener.
+ * @param[in] listener Listener to close.
+ */
+void close_listener(struct Listener* listener)
+{
+ assert(0 != listener);
+ /*
+ * remove from listener list
+ */
+ if (listener == ListenerPollList)
+ ListenerPollList = listener->next;
+ else {
+ struct Listener* prev = ListenerPollList;
+ for ( ; prev; prev = prev->next) {
+ if (listener == prev->next) {
+ prev->next = listener->next;
+ break;
+ }
+ }
+ }
+ if (-1 < listener->fd_v4) {
+ close(listener->fd_v4);
+ socket_del(&listener->socket_v4);
+ listener->fd_v4 = -1;
+ }
+ if (-1 < listener->fd_v6) {
+ close(listener->fd_v6);
+ socket_del(&listener->socket_v6);
+ listener->fd_v6 = -1;
+ }
+ free_listener(listener);
+}
+
+/** Close all inactive listeners. */
+void close_listeners(void)
+{
+ struct Listener* listener;
+ struct Listener* listener_next = 0;
+ /*
+ * close all 'extra' listening ports we have
+ */
+ for (listener = ListenerPollList; listener; listener = listener_next) {
+ listener_next = listener->next;
+ if (!listener_active(listener) && 0 == listener->ref_count)
+ close_listener(listener);
+ }
+}
+
+/** Dereference the listener previously associated with a client.
+ * @param[in] listener Listener to dereference.
+ */
+void release_listener(struct Listener* listener)
+{
+ assert(0 != listener);
+ assert(0 < listener->ref_count);
+ if (0 == --listener->ref_count && !listener_active(listener))
+ close_listener(listener);
+}
+
+/** Accept a connection on a listener.
+ * @param[in] ev Socket callback structure.
+ */
+static void accept_connection(struct Event* ev)
+{
+ struct Listener* listener;
+ struct irc_sockaddr addr;
+ int fd;
+
+ assert(0 != ev_socket(ev));
+ assert(0 != s_data(ev_socket(ev)));
+
+ listener = (struct Listener*) s_data(ev_socket(ev));
+
+ if (ev_type(ev) == ET_DESTROY) /* being destroyed */
+ return;
+ else {
+ assert(ev_type(ev) == ET_ACCEPT || ev_type(ev) == ET_ERROR);
+
+ listener->last_accept = CurrentTime;
+ /*
+ * 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.
+ *
+ * This piece of code implements multi-accept, based
+ * on the idea that poll/select can only be efficient,
+ * if we succeed in handling all available events,
+ * i.e. accept all pending connections.
+ *
+ * http://www.hpl.hp.com/techreports/2000/HPL-2000-174.html
+ */
+ while (1)
+ {
+ if ((fd = os_accept(s_fd(ev_socket(ev)), &addr)) == -1)
+ {
+ if (errno == EAGAIN ||
+#ifdef EWOULDBLOCK
+ errno == EWOULDBLOCK)
+#endif
+ return;
+ /* Lotsa admins seem to have problems with not giving enough file
+ * descriptors to their server so we'll add a generic warning mechanism
+ * here. If it turns out too many messages are generated for
+ * meaningless reasons we can filter them back.
+ */
+ sendto_opmask_butone(0, SNO_TCPCOMMON,
+ "Unable to accept connection: %m");
+ return;
+ }
+ /*
+ * check for connection limit. If this fd exceeds the limit,
+ * all further accept()ed connections will also exceed it.
+ * Enable the server to clear out other connections before
+ * continuing to accept() new connections.
+ */
+ if (fd > MAXCLIENTS - 1)
+ {
+ ++ServerStats->is_ref;
+ send(fd, "ERROR :All connections in use\r\n", 32, 0);
+ close(fd);
+ return;
+ }
+ /*
+ * check to see if listener is shutting down. Continue
+ * to accept(), because it makes sense to clear our the
+ * socket's queue as fast as possible.
+ */
+ if (!listener_active(listener))
+ {
+ ++ServerStats->is_ref;
+ send(fd, "ERROR :Use another port\r\n", 25, 0);
+ close(fd);
+ continue;
+ }
+ /*
+ * check to see if connection is allowed for this address mask
+ */
+ if (!ipmask_check(&addr.addr, &listener->mask, listener->mask_bits))
+ {
+ ++ServerStats->is_ref;
+ send(fd, "ERROR :Use another port\r\n", 25, 0);
+ close(fd);
+ continue;
+ }
+ ++ServerStats->is_ac;
+ /* nextping = CurrentTime; */
+ add_connection(listener, fd);
+ }
+ }
+}
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