/*
* OpenVPN -- An application to securely tunnel IP networks
* over a single TCP/UDP port, with support for SSL/TLS-based
* session authentication and key exchange,
* packet encryption, packet authentication, and
* packet compression.
*
* Copyright (C) 2002-2009 OpenVPN Technologies, Inc. <sales@openvpn.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* 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 (see the file COPYING included with this
* distribution); if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "syshead.h"
#include "forward.h"
#include "helper.h"
#include "pool.h"
#include "push.h"
#include "memdbg.h"
#if P2MP_SERVER
static const char *
print_netmask (int netbits, struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (128, gc);
const in_addr_t netmask = netbits_to_netmask (netbits);
buf_printf (&out, "%s (/%d)", print_in_addr_t (netmask, 0, gc), netbits);
return BSTR (&out);
}
static const char *
print_opt_route_gateway (const in_addr_t route_gateway, struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (128, gc);
ASSERT (route_gateway);
buf_printf (&out, "route-gateway %s", print_in_addr_t (route_gateway, 0, gc));
return BSTR (&out);
}
static const char *
print_opt_route_gateway_dhcp (struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (32, gc);
buf_printf (&out, "route-gateway dhcp");
return BSTR (&out);
}
static const char *
print_opt_route (const in_addr_t network, const in_addr_t netmask, struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (128, gc);
ASSERT (network);
if (netmask)
buf_printf (&out, "route %s %s",
print_in_addr_t (network, 0, gc),
print_in_addr_t (netmask, 0, gc));
else
buf_printf (&out, "route %s",
print_in_addr_t (network, 0, gc));
return BSTR (&out);
}
static const char *
print_opt_topology (const int topology, struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (128, gc);
buf_printf (&out, "topology %s", print_topology (topology));
return BSTR (&out);
}
static const char *
print_str_int (const char *str, const int i, struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (128, gc);
buf_printf (&out, "%s %d", str, i);
return BSTR (&out);
}
static const char *
print_str (const char *str, struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (128, gc);
buf_printf (&out, "%s", str);
return BSTR (&out);
}
static void
helper_add_route (const in_addr_t network, const in_addr_t netmask, struct options *o)
{
rol_check_alloc (o);
add_route_to_option_list (o->routes,
print_in_addr_t (network, 0, &o->gc),
print_in_addr_t (netmask, 0, &o->gc),
NULL,
NULL);
}
static void
verify_common_subnet (const char *opt, const in_addr_t a, const in_addr_t b, const in_addr_t subnet)
{
struct gc_arena gc = gc_new ();
if ((a & subnet) != (b & subnet))
msg (M_USAGE, "%s IP addresses %s and %s are not in the same %s subnet",
opt,
print_in_addr_t (a, 0, &gc),
print_in_addr_t (b, 0, &gc),
print_in_addr_t (subnet, 0, &gc));
gc_free (&gc);
}
#endif
/*
* Process server, server-bridge, and client helper
* directives after the parameters themselves have been
* parsed and placed in struct options.
*/
void
helper_client_server (struct options *o)
{
struct gc_arena gc = gc_new ();
#if P2MP
#if P2MP_SERVER
/*
*
* HELPER DIRECTIVE:
*
* server 10.8.0.0 255.255.255.0
*
* EXPANDS TO:
*
* mode server
* tls-server
* push "topology [topology]"
*
* if tun AND (topology == net30 OR topology == p2p):
* ifconfig 10.8.0.1 10.8.0.2
* if !nopool:
* ifconfig-pool 10.8.0.4 10.8.0.251
* route 10.8.0.0 255.255.255.0
* if client-to-client:
* push "route 10.8.0.0 255.255.255.0"
* else if topology == net30:
* push "route 10.8.0.1"
*
* if tap OR (tun AND topology == subnet):
* ifconfig 10.8.0.1 255.255.255.0
* if !nopool:
* ifconfig-pool 10.8.0.2 10.8.0.254 255.255.255.0
* push "route-gateway 10.8.0.1"
*/
/*
* Get tun/tap/null device type
*/
const int dev = dev_type_enum (o->dev, o->dev_type);
const int topology = o->topology;
if (o->server_defined)
{
int netbits = -2;
bool status = false;
if (o->client)
msg (M_USAGE, "--server and --client cannot be used together");
if (o->server_bridge_defined || o->server_bridge_proxy_dhcp)
msg (M_USAGE, "--server and --server-bridge cannot be used together");
if (o->shared_secret_file)
msg (M_USAGE, "--server and --secret cannot be used together (you must use SSL/TLS keys)");
if (!(o->server_flags & SF_NOPOOL) && o->ifconfig_pool_defined)
msg (M_USAGE, "--server already defines an ifconfig-pool, so you can't also specify --ifconfig-pool explicitly");
if (!(dev == DEV_TYPE_TAP || dev == DEV_TYPE_TUN))
msg (M_USAGE, "--server directive only makes sense with --dev tun or --dev tap");
status = netmask_to_netbits (o->server_network, o->server_netmask, &netbits);
if (!status)
msg (M_USAGE, "--server directive network/netmask combination is invalid");
if (netbits < 0)
msg (M_USAGE, "--server directive netmask is invalid");
if (netbits < IFCONFIG_POOL_MIN_NETBITS)
msg (M_USAGE, "--server directive netmask allows for too many host addresses (subnet must be %s or higher)",
print_netmask (IFCONFIG_POOL_MIN_NETBITS, &gc));
if (dev == DEV_TYPE_TUN)
{
int pool_end_reserve = 4;
if (netbits > 29)
msg (M_USAGE, "--server directive when used with --dev tun must define a subnet of %s or lower",
print_netmask (29, &gc));
if (netbits == 29)
pool_end_reserve = 0;
o->mode = MODE_SERVER;
o->tls_server = true;
if (topology == TOP_NET30 || topology == TOP_P2P)
{
o->ifconfig_local = print_in_addr_t (o->server_network + 1, 0, &o->gc);
o->ifconfig_remote_netmask = print_in_addr_t (o->server_network + 2, 0, &o->gc);
if (!(o->server_flags & SF_NOPOOL))
{
o->ifconfig_pool_defined = true;
o->ifconfig_pool_start = o->server_network + 4;
o->ifconfig_pool_end = (o->server_network | ~o->server_netmask) - pool_end_reserve;
ifconfig_pool_verify_range (M_USAGE, o->ifconfig_pool_start, o->ifconfig_pool_end);
}
helper_add_route (o->server_network, o->server_netmask, o);
if (o->enable_c2c)
push_option (o, print_opt_route (o->server_network, o->server_netmask, &o->gc), M_USAGE);
else if (topology == TOP_NET30)
push_option (o, print_opt_route (o->server_network + 1, 0, &o->gc), M_USAGE);
}
else if (topology == TOP_SUBNET)
{
o->ifconfig_local = print_in_addr_t (o->server_network + 1, 0, &o->gc);
o->ifconfig_remote_netmask = print_in_addr_t (o->server_netmask, 0, &o->gc);
if (!(o->server_flags & SF_NOPOOL))
{
o->ifconfig_pool_defined = true;
o->ifconfig_pool_start = o->server_network + 2;
o->ifconfig_pool_end = (o->server_network | ~o->server_netmask) - 2;
ifconfig_pool_verify_range (M_USAGE, o->ifconfig_pool_start, o->ifconfig_pool_end);
}
o->ifconfig_pool_netmask = o->server_netmask;
push_option (o, print_opt_route_gateway (o->server_network + 1, &o->gc), M_USAGE);
}
else
ASSERT (0);
push_option (o, print_opt_topology (topology, &o->gc), M_USAGE);
}
else if (dev == DEV_TYPE_TAP)
{
if (netbits > 30)
msg (M_USAGE, "--server directive when used with --dev tap must define a subnet of %s or lower",
print_netmask (30, &gc));
o->mode = MODE_SERVER;
o->tls_server = true;
o->ifconfig_local = print_in_addr_t (o->server_network + 1, 0, &o->gc);
o->ifconfig_remote_netmask = print_in_addr_t (o->server_netmask, 0, &o->gc);
if (!(o->server_flags & SF_NOPOOL))
{
o->ifconfig_pool_defined = true;
o->ifconfig_pool_start = o->server_network + 2;
o->ifconfig_pool_end = (o->server_network | ~o->server_netmask) - 1;
ifconfig_pool_verify_range (M_USAGE, o->ifconfig_pool_start, o->ifconfig_pool_end);
}
o->ifconfig_pool_netmask = o->server_netmask;
push_option (o, print_opt_route_gateway (o->server_network + 1, &o->gc), M_USAGE);
}
else
{
ASSERT (0);
}
/* set push-ifconfig-constraint directive */
if ((dev == DEV_TYPE_TAP || topology == TOP_SUBNET))
{
o->push_ifconfig_constraint_defined = true;
o->push_ifconfig_constraint_network = o->server_network;
o->push_ifconfig_constraint_netmask = o->server_netmask;
}
}
/*
* HELPER DIRECTIVE:
*
* server-bridge 10.8.0.4 255.255.255.0 10.8.0.128 10.8.0.254
*
* EXPANDS TO:
*
* mode server
* tls-server
*
* ifconfig-pool 10.8.0.128 10.8.0.254 255.255.255.0
* push "route-gateway 10.8.0.4"
*
* OR
*
* server-bridge
*
* EXPANDS TO:
*
* mode server
* tls-server
*
* if !nogw:
* push "route-gateway dhcp"
*/
else if (o->server_bridge_defined | o->server_bridge_proxy_dhcp)
{
if (o->client)
msg (M_USAGE, "--server-bridge and --client cannot be used together");
if (!(o->server_flags & SF_NOPOOL) && o->ifconfig_pool_defined)
msg (M_USAGE, "--server-bridge already defines an ifconfig-pool, so you can't also specify --ifconfig-pool explicitly");
if (o->shared_secret_file)
msg (M_USAGE, "--server-bridge and --secret cannot be used together (you must use SSL/TLS keys)");
if (dev != DEV_TYPE_TAP)
msg (M_USAGE, "--server-bridge directive only makes sense with --dev tap");
if (o->server_bridge_defined)
{
verify_common_subnet ("--server-bridge", o->server_bridge_ip, o->server_bridge_pool_start, o->server_bridge_netmask);
verify_common_subnet ("--server-bridge", o->server_bridge_pool_start, o->server_bridge_pool_end, o->server_bridge_netmask);
verify_common_subnet ("--server-bridge", o->server_bridge_ip, o->server_bridge_pool_end, o->server_bridge_netmask);
}
o->mode = MODE_SERVER;
o->tls_server = true;
if (o->server_bridge_defined)
{
o->ifconfig_pool_defined = true;
o->ifconfig_pool_start = o->server_bridge_pool_start;
o->ifconfig_pool_end = o->server_bridge_pool_end;
ifconfig_pool_verify_range (M_USAGE, o->ifconfig_pool_start, o->ifconfig_pool_end);
o->ifconfig_pool_netmask = o->server_bridge_netmask;
push_option (o, print_opt_route_gateway (o->server_bridge_ip, &o->gc), M_USAGE);
}
else if (o->server_bridge_proxy_dhcp && !(o->server_flags & SF_NO_PUSH_ROUTE_GATEWAY))
{
push_option (o, print_opt_route_gateway_dhcp (&o->gc), M_USAGE);
}
}
else
#endif /* P2MP_SERVER */
/*
* HELPER DIRECTIVE:
*
* client
*
* EXPANDS TO:
*
* pull
* tls-client
*/
if (o->client)
{
if (o->key_method != 2)
msg (M_USAGE, "--client requires --key-method 2");
o->pull = true;
o->tls_client = true;
}
#endif /* P2MP */
gc_free (&gc);
}
/*
*
* HELPER DIRECTIVE:
*
* keepalive 10 60
*
* EXPANDS TO:
*
* if mode server:
* ping 10
* ping-restart 120
* push "ping 10"
* push "ping-restart 60"
* else
* ping 10
* ping-restart 60
*/
void
helper_keepalive (struct options *o)
{
if (o->keepalive_ping || o->keepalive_timeout)
{
/*
* Sanity checks.
*/
if (o->keepalive_ping <= 0 || o->keepalive_timeout <= 0)
msg (M_USAGE, "--keepalive parameters must be > 0");
if (o->keepalive_ping * 2 > o->keepalive_timeout)
msg (M_USAGE, "the second parameter to --keepalive (restart timeout=%d) must be at least twice the value of the first parameter (ping interval=%d). A ratio of 1:5 or 1:6 would be even better. Recommended setting is --keepalive 10 60.",
o->keepalive_timeout,
o->keepalive_ping);
if (o->ping_send_timeout || o->ping_rec_timeout)
msg (M_USAGE, "--keepalive conflicts with --ping, --ping-exit, or --ping-restart. If you use --keepalive, you don't need any of the other --ping directives.");
/*
* Expand.
*/
if (o->mode == MODE_POINT_TO_POINT)
{
o->ping_rec_timeout_action = PING_RESTART;
o->ping_send_timeout = o->keepalive_ping;
o->ping_rec_timeout = o->keepalive_timeout;
}
#if P2MP_SERVER
else if (o->mode == MODE_SERVER)
{
o->ping_rec_timeout_action = PING_RESTART;
o->ping_send_timeout = o->keepalive_ping;
o->ping_rec_timeout = o->keepalive_timeout * 2;
push_option (o, print_str_int ("ping", o->keepalive_ping, &o->gc), M_USAGE);
push_option (o, print_str_int ("ping-restart", o->keepalive_timeout, &o->gc), M_USAGE);
}
#endif
else
{
ASSERT (0);
}
}
}
/*
*
* HELPER DIRECTIVE:
*
* tcp-nodelay
*
* EXPANDS TO:
*
* if mode server:
* socket-flags TCP_NODELAY
* push "socket-flags TCP_NODELAY"
*/
void
helper_tcp_nodelay (struct options *o)
{
#if P2MP_SERVER
if (o->server_flags & SF_TCP_NODELAY_HELPER)
{
if (o->mode == MODE_SERVER)
{
o->sockflags |= SF_TCP_NODELAY;
push_option (o, print_str ("socket-flags TCP_NODELAY", &o->gc), M_USAGE);
}
else
{
ASSERT (0);
}
}
#endif
}