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-rw-r--r--src/openvpn/helper.c537
1 files changed, 537 insertions, 0 deletions
diff --git a/src/openvpn/helper.c b/src/openvpn/helper.c
new file mode 100644
index 0000000..d9eef03
--- /dev/null
+++ b/src/openvpn/helper.c
@@ -0,0 +1,537 @@
+/*
+ * 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) 2002-2010 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
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#elif defined(_MSC_VER)
+#include "config-msvc.h"
+#endif
+
+#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
+
+/*
+ * Get tun/tap/null device type
+ */
+ const int dev = dev_type_enum (o->dev, o->dev_type);
+ const int topology = o->topology;
+
+ /*
+ *
+ * HELPER DIRECTIVE for IPv6
+ *
+ * server-ipv6 2001:db8::/64
+ *
+ * EXPANDS TO:
+ *
+ * tun-ipv6
+ * push "tun-ipv6"
+ * ifconfig-ipv6 2001:db8::1 2001:db8::2
+ * if !nopool:
+ * ifconfig-ipv6-pool 2001:db8::1:0/64
+ *
+ */
+ if ( o->server_ipv6_defined )
+ {
+ if ( ! o->server_defined )
+ {
+ msg (M_USAGE, "--server-ipv6 must be used together with --server");
+ }
+ if ( o->server_flags & SF_NOPOOL )
+ {
+ msg( M_USAGE, "--server-ipv6 is incompatible with 'nopool' option" );
+ }
+ if ( o->ifconfig_ipv6_pool_defined )
+ {
+ msg( M_USAGE, "--server-ipv6 already defines an ifconfig-ipv6-pool, so you can't also specify --ifconfig-pool explicitly");
+ }
+
+ /* local ifconfig is "base address + 1" and "+2" */
+ o->ifconfig_ipv6_local =
+ print_in6_addr( add_in6_addr( o->server_network_ipv6, 1), 0, &o->gc );
+ o->ifconfig_ipv6_remote =
+ print_in6_addr( add_in6_addr( o->server_network_ipv6, 2), 0, &o->gc );
+ o->ifconfig_ipv6_netbits = o->server_netbits_ipv6;
+
+ /* pool starts at "base address + 0x1000" - leave enough room */
+ ASSERT( o->server_netbits_ipv6 <= 112 ); /* want 16 bits */
+
+ o->ifconfig_ipv6_pool_defined = true;
+ o->ifconfig_ipv6_pool_base =
+ add_in6_addr( o->server_network_ipv6, 0x1000 );
+ o->ifconfig_ipv6_pool_netbits = o->server_netbits_ipv6;
+
+ o->tun_ipv6 = true;
+
+ push_option( o, "tun-ipv6", M_USAGE );
+ }
+
+ /*
+ *
+ * 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"
+ */
+
+ 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
+}
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