elemental-ircd/src/listener.c

588 lines
14 KiB
C

/*
* 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 "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 "s_auth.h"
#include "reject.h"
#include "s_conf.h"
#include "hostmask.h"
#include "sslproc.h"
#include "hash.h"
#ifndef INADDR_NONE
#define INADDR_NONE ((unsigned int) 0xffffffff)
#endif
#if defined(NO_IN6ADDR_ANY) && defined(RB_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 struct Listener *ListenerPollList = NULL;
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 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(struct rb_sockaddr_storage));
listener->next = NULL;
return listener;
}
void
free_listener(struct Listener *listener)
{
s_assert(NULL != listener);
if(listener == NULL)
return;
/*
* 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;
}
}
}
/* 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 struct Listener *listener)
{
static char buf[HOSTLEN + HOSTLEN + PORTNAMELEN + 4];
int port = 0;
s_assert(NULL != listener);
if(listener == NULL)
return NULL;
#ifdef RB_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)
{
struct Listener *listener = 0;
for (listener = ListenerPollList; listener; listener = listener->next)
{
sendto_one_numeric(source_p, RPL_STATSPLINE,
form_str(RPL_STATSPLINE), 'P',
#ifdef RB_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",
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.
*
* 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(struct Listener *listener)
{
rb_fde_t *F;
int ret;
int opt = 1;
/*
* At first, open a new socket
*/
F = rb_socket(GET_SS_FAMILY(&listener->addr), SOCK_STREAM, 0, "Listener socket");
#ifdef RB_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))
{
rb_inet_ntop(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)
{
rb_inet_ntop(AF_INET, &in->sin_addr, listener->vhost, sizeof(listener->vhost));
listener->name = listener->vhost;
}
}
if(F == NULL)
{
ilog_error("opening listener socket");
return 0;
}
else if((maxconnections - 10) < rb_get_fd(F)) /* XXX this is kinda bogus*/
{
ilog_error("no more connections left for listener");
rb_close(F);
return 0;
}
/*
* XXX - we don't want to do all this crap for a listener
* set_sock_opts(listener);
*/
if(setsockopt(rb_get_fd(F), SOL_SOCKET, SO_REUSEADDR, (char *) &opt, sizeof(opt)))
{
ilog_error("setting SO_REUSEADDR for listener");
rb_close(F);
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(rb_get_fd(F), (struct sockaddr *) &listener->addr, GET_SS_LEN(&listener->addr)))
{
ilog_error("binding listener socket");
rb_close(F);
return 0;
}
if((ret = rb_listen(F, RATBOX_SOMAXCONN)))
{
ilog_error("listen()");
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)
{
struct Listener *listener = NULL;
struct Listener *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->F == NULL)
last_closed = listener;
else
return(listener);
}
break;
}
#ifdef RB_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->F == NULL)
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, int ssl)
{
struct Listener *listener;
struct rb_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(rb_inet_pton(family, vhost_ip, &((struct sockaddr_in *)&vaddr)->sin_addr) <= 0)
return;
}
#ifdef RB_IPV6
else
{
if(rb_inet_pton(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 RB_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 RB_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->F != NULL)
return;
}
else
{
listener = make_listener(&vaddr);
listener->next = ListenerPollList;
ListenerPollList = listener;
}
listener->F = NULL;
listener->ssl = ssl;
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()
{
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;
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(struct Listener *listener, rb_fde_t *F, struct sockaddr *sai, struct sockaddr *lai, void *ssl_ctl)
{
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 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));
new_client->localClient->F = F;
add_to_cli_fd_hash(new_client);
new_client->localClient->listener = listener;
new_client->localClient->ssl_ctl = ssl_ctl;
if(ssl_ctl != NULL || rb_fd_ssl(F))
SetSSL(new_client);
++listener->ref_count;
start_auth(new_client);
}
static const char *toofast = "ERROR :Reconnecting too fast, throttled.\r\n";
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;
if(listener->ssl && (!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_ALL,
"All connections in use. (%s)",
get_listener_name(listener));
last_oper_notice = rb_current_time();
}
rb_write(F, "ERROR :All connections in use\r\n", 32);
rb_close(F);
/* Re-register a new IO request for the next accept .. */
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(ConfigFileEntry.dline_with_reason)
{
len = rb_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';
}
}
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))
return 0;
if(throttle_add(addr))
{
rb_write(F, toofast, strlen(toofast));
rb_close(F);
return 0;
}
return 1;
}
static void
accept_ssld(rb_fde_t *F, struct sockaddr *addr, struct sockaddr *laddr, struct Listener *listener)
{
ssl_ctl_t *ctl;
rb_fde_t *xF[2];
if(rb_socketpair(AF_UNIX, SOCK_STREAM, 0, &xF[0], &xF[1], "Incoming ssld Connection") == -1)
{
ilog_error("creating SSL/TLS socket pairs");
rb_close(F);
return;
}
ctl = start_ssld_accept(F, xF[1], rb_get_fd(xF[0])); /* this will close F for us */
add_connection(listener, xF[0], addr, laddr, ctl);
}
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;
}
if(listener->ssl)
accept_ssld(F, addr, (struct sockaddr *)&lip, listener);
else
add_connection(listener, F, addr, (struct sockaddr *)&lip, NULL);
}