Merge branch 'forecast'

Implement a forecast plugin that supports forwarding of multi- and broadcast
messages between a LAN and clients or between connected clients. It uses
IPsec policy marks to send packets over multiple identical multi- and broadcast
policies.

NEWS

@@ -12,6 +12,13 @@
   same NAT device for client-initiated flows. A common use case is to protect
   L2TP/IPsec, as supported by some systems.
 
+- The forecast plugin can forward broadcast and multicast messages between
+  connected clients and a LAN. For CHILD_SA using unique marks, it sets up
+  the required Netfilter rules and uses a multicast/broadcast listener that
+  forwards such messages to all connected clients. This plugin is designed for
+  Windows 7 IKEv2 clients, which announces its services over the tunnel if the
+  negotiated IPsec policy allows it.
+
 
 strongswan-5.2.2
 ----------------

conf/Makefile.am

@@ -46,6 +46,7 @@ plugins = \
 	plugins/eap-ttls.opt \
 	plugins/error-notify.opt \
 	plugins/ext-auth.opt \
+	plugins/forecast.opt \
 	plugins/gcrypt.opt \
 	plugins/ha.opt \
 	plugins/imc-attestation.opt \

conf/plugins/forecast.opt

@@ -0,0 +1,29 @@
+charon.plugins.forecast.interface =
+	Local interface to listen for broadcasts to forward.
+
+	Name of the local interface to listen for broadcasts messages to forward.
+	If no interface is configured, the first usable interface is used, which
+	is usually just fine for single-homed hosts. If your host has multiple
+	interfaces, set this option to the local LAN interface you want to forward
+	broadcasts from/to.
+
+charon.plugins.forecast.reinject =
+	CHILD_SA configurations names to perform multi/broadcast reinjection.
+
+	Comma separated list of CHILD_SA configuration names for which to perform
+	multi/broadcast reinjection. For clients connecting over such a
+	configuration, any multi/broadcast received over the tunnel gets reinjected
+	to all active tunnels. This makes the broadcasts visible to other peers,
+	and for examples allows clients to see others shares. If disabled,
+	multi/broadcast messages received over a tunnel are injected to the local
+	network only, but not to other IPsec clients.
+
+charon.plugins.forecast.groups = 224.0.0.1,224.0.0.22,224.0.0.251,224.0.0.252,239.255.255.250
+	Multicast groups to join locally, allowing forwarding of them.
+
+	Comma separated list of multicast groups to join locally. The local host
+	receives and forwards packets in the local LAN for joined multicast groups
+	only. Packets matching the list of multicast groups get forwarded to
+	connected clients. The default group includes host multicasts, IGMP, mDNS,
+	LLMNR and SSDP/WS-Discovery, and is usually a good choice for Windows
+	clients.

configure.ac

@@ -247,6 +247,7 @@ ARG_ENABL_SET([tnccs-dynamic],  [enable dynamic TNCCS protocol discovery module.
 ARG_ENABL_SET([android-log],    [enable Android specific logger plugin.])
 ARG_ENABL_SET([certexpire],     [enable CSV export of expiration dates of used certificates.])
 ARG_ENABL_SET([connmark],       [enable connmark plugin using conntrack based marks to select return path SA.])
+ARG_ENABL_SET([forecast],       [enable forecast plugin forwarding broadcast/multicast messages.])
 ARG_ENABL_SET([duplicheck],     [advanced duplicate checking plugin using liveness checks.])
 ARG_ENABL_SET([error-notify],   [enable error notification plugin.])
 ARG_ENABL_SET([farp],           [enable ARP faking plugin that responds to ARP requests to peers virtual IP])
@@ -1270,6 +1271,7 @@ ADD_PLUGIN([socket-default],       [c charon nm cmd])
 ADD_PLUGIN([socket-dynamic],       [c charon cmd])
 ADD_PLUGIN([socket-win],           [c charon])
 ADD_PLUGIN([connmark],             [c charon])
+ADD_PLUGIN([forecast],             [c charon])
 ADD_PLUGIN([farp],                 [c charon])
 ADD_PLUGIN([stroke],               [c charon])
 ADD_PLUGIN([vici],                 [c charon])
@@ -1478,6 +1480,7 @@ AM_CONDITIONAL(USE_SOCKET_DEFAULT, test x$socket_default = xtrue)
 AM_CONDITIONAL(USE_SOCKET_DYNAMIC, test x$socket_dynamic = xtrue)
 AM_CONDITIONAL(USE_SOCKET_WIN, test x$socket_win = xtrue)
 AM_CONDITIONAL(USE_CONNMARK, test x$connmark = xtrue)
+AM_CONDITIONAL(USE_FORECAST, test x$forecast = xtrue)
 AM_CONDITIONAL(USE_FARP, test x$farp = xtrue)
 AM_CONDITIONAL(USE_ADDRBLOCK, test x$addrblock = xtrue)
 AM_CONDITIONAL(USE_UNITY, test x$unity = xtrue)
@@ -1713,6 +1716,7 @@ AC_CONFIG_FILES([
 	src/libcharon/plugins/socket_dynamic/Makefile
 	src/libcharon/plugins/socket_win/Makefile
 	src/libcharon/plugins/connmark/Makefile
+	src/libcharon/plugins/forecast/Makefile
 	src/libcharon/plugins/farp/Makefile
 	src/libcharon/plugins/smp/Makefile
 	src/libcharon/plugins/sql/Makefile

src/libcharon/Makefile.am

@@ -216,6 +216,13 @@ if MONOLITHIC
 endif
 endif
 
+if USE_FORECAST
+  SUBDIRS += plugins/forecast
+if MONOLITHIC
+  libcharon_la_LIBADD += plugins/forecast/libstrongswan-forecast.la
+endif
+endif
+
 if USE_FARP
   SUBDIRS += plugins/farp
 if MONOLITHIC

src/libcharon/plugins/forecast/Makefile.am

@@ -0,0 +1,21 @@
+AM_CPPFLAGS = \
+	-I$(top_srcdir)/src/libstrongswan \
+	-I$(top_srcdir)/src/libhydra \
+	-I$(top_srcdir)/src/libcharon
+
+AM_CFLAGS = \
+	$(PLUGIN_CFLAGS)
+
+if MONOLITHIC
+noinst_LTLIBRARIES = libstrongswan-forecast.la
+else
+plugin_LTLIBRARIES = libstrongswan-forecast.la
+endif
+
+libstrongswan_forecast_la_SOURCES = \
+	forecast_listener.h forecast_listener.c \
+	forecast_forwarder.h forecast_forwarder.c \
+	forecast_plugin.h forecast_plugin.c
+
+libstrongswan_forecast_la_LDFLAGS = -module -avoid-version
+libstrongswan_forecast_la_LIBADD  = -lip4tc

src/libcharon/plugins/forecast/forecast_forwarder.c

@@ -0,0 +1,496 @@
+/*
+ * Copyright (C) 2010-2014 Martin Willi
+ * Copyright (C) 2010-2014 revosec AG
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#include "forecast_forwarder.h"
+
+#include <errno.h>
+#include <unistd.h>
+#include <netinet/ip.h>
+#include <netinet/udp.h>
+#include <linux/socket.h>
+#include <netinet/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/filter.h>
+#include <sys/ioctl.h>
+#include <ifaddrs.h>
+#include <net/if.h>
+
+#include <hydra.h>
+#include <daemon.h>
+#include <threading/thread.h>
+#include <processing/jobs/callback_job.h>
+
+#define BOOTP_SERVER_PORT 67
+#define BOOTP_CLIENT_PORT 68
+
+typedef struct private_forecast_forwarder_t private_forecast_forwarder_t;
+typedef struct private_kernel_listener_t private_kernel_listener_t;
+
+/**
+ * Private data of registered kernel listener
+ */
+struct private_kernel_listener_t {
+
+	/**
+	 * Implements kernel_listener_t
+	 */
+	kernel_listener_t listener;
+
+	/**
+	 * Listener that knows active addresses
+	 */
+	forecast_listener_t *fc;
+
+	/**
+	 * current broadcast address of internal network
+	 */
+	u_int32_t broadcast;
+
+	/**
+	 * LAN interface index
+	 */
+	int ifindex;
+
+	/**
+	 * Packet socket
+	 */
+	int pkt;
+
+	/**
+	 * RAW socket
+	 */
+	int raw;
+};
+
+/**
+ * Private data of an forecast_forwarder_t object.
+ */
+struct private_forecast_forwarder_t {
+
+	/**
+	 * Public forecast_forwarder_t interface.
+	 */
+	forecast_forwarder_t public;
+
+	/**
+	 * Public kernel_listener_t interface.
+	 */
+	private_kernel_listener_t kernel;
+};
+
+/**
+ * Send a broadcast/multicast packet to a network
+ */
+static void send_net(private_forecast_forwarder_t *this,
+					 struct sockaddr_ll *addr, void *buf, size_t len)
+{
+	if (sendto(this->kernel.pkt, buf, len, 0,
+			   (struct sockaddr*)addr, sizeof(*addr)) != len)
+	{
+		DBG1(DBG_NET, "forecast send_net() failed: %s", strerror(errno));
+	}
+}
+
+/**
+ * Send a broadcast/multicast packet to a peer
+ */
+static void send_peer(private_forecast_forwarder_t *this, u_int32_t dst,
+					  void *buf, size_t len, int mark)
+{
+	struct sockaddr_in addr = {
+		.sin_family = AF_INET,
+		.sin_addr.s_addr = dst,
+	};
+
+	if (setsockopt(this->kernel.raw, SOL_SOCKET, SO_MARK,
+				   &mark, sizeof(mark)) != 0)
+	{
+		DBG1(DBG_NET, "forecast setting SO_MARK failed: %s", strerror(errno));
+	}
+	if (sendto(this->kernel.raw, buf, len, 0,
+			   (struct sockaddr*)&addr, sizeof(addr)) != len)
+	{
+		DBG1(DBG_NET, "forecast send_peer() failed: %s", strerror(errno));
+	}
+}
+
+/**
+ * Check if an IP packet is BOOTP/DHCP
+ */
+static bool is_bootp(void *buf, size_t len)
+{
+	struct __attribute__((__packed__)) {
+		struct iphdr ip;
+		struct udphdr udp;
+	} *pkt = buf;
+
+	if (len > sizeof(*pkt))
+	{
+		if (ntohs(pkt->udp.source) == BOOTP_CLIENT_PORT &&
+			ntohs(pkt->udp.dest) == BOOTP_SERVER_PORT)
+		{
+			return TRUE;
+		}
+		if (ntohs(pkt->udp.source) == BOOTP_SERVER_PORT &&
+			ntohs(pkt->udp.dest) == BOOTP_CLIENT_PORT)
+		{
+			return TRUE;
+		}
+	}
+	return FALSE;
+}
+
+/**
+ * Broadcast/Multicast receiver
+ */
+static bool receive_casts(private_forecast_forwarder_t *this)
+{
+	struct __attribute__((packed)) {
+		struct iphdr hdr;
+		char data[2048];
+	} buf;
+	char *type;
+	ssize_t len;
+	u_int mark, origin = 0;
+	host_t *src, *dst;
+	traffic_selector_t *ts;
+	enumerator_t *enumerator;
+	struct sockaddr_ll addr;
+	socklen_t alen = sizeof(addr);
+	bool reinject;
+
+	len = recvfrom(this->kernel.pkt, &buf, sizeof(buf), MSG_DONTWAIT,
+				   (struct sockaddr*)&addr, &alen);
+	if (len < 0)
+	{
+		if (errno != EAGAIN && errno != EWOULDBLOCK)
+		{
+			DBG1(DBG_NET, "receiving from forecast socket failed: %s",
+				 strerror(errno));
+		}
+		return TRUE;
+	}
+	else if (len < sizeof(struct iphdr))
+	{
+		DBG1(DBG_NET, "received short forecast packet: %zd bytes", len);
+		return TRUE;
+	}
+	if (is_bootp(&buf, len))
+	{	/* don't forward DHCP broadcasts */
+		return TRUE;
+	}
+
+	src = host_create_from_chunk(AF_INET, chunk_from_thing(buf.hdr.saddr), 0);
+	dst = host_create_from_chunk(AF_INET, chunk_from_thing(buf.hdr.daddr), 0);
+
+	/* create valid broadcast/multicast MAC to send out */
+	if (IN_MULTICAST(ntohl(buf.hdr.daddr)))
+	{
+		type = "multi";
+		ETHER_MAP_IP_MULTICAST(&buf.hdr.daddr, addr.sll_addr);
+	}
+	else
+	{
+		type = "broad";
+		memset(&addr.sll_addr, 0xFF, sizeof(addr.sll_addr));
+	}
+	DBG2(DBG_NET, "forecast intercepted packet: %H to %H", src, dst);
+
+	/* find mark of originating tunnel */
+	enumerator = this->kernel.fc->create_enumerator(this->kernel.fc, FALSE);
+	while (enumerator->enumerate(enumerator, &ts, &mark, &reinject))
+	{
+		if (ts->includes(ts, src))
+		{
+			origin = mark;
+			break;
+		}
+	}
+	enumerator->destroy(enumerator);
+
+	/* send packet over all tunnels, but not the packets origin */
+	enumerator = this->kernel.fc->create_enumerator(this->kernel.fc, FALSE);
+	while (enumerator->enumerate(enumerator, &ts, &mark, &reinject))
+	{
+		if (ts->includes(ts, dst))
+		{
+			if ((reinject && origin != mark) || origin == 0)
+			{
+				DBG2(DBG_NET, "forwarding a %H %scast from %H to peer %R (%u)",
+					 dst, type, src, ts, mark);
+				send_peer(this, buf.hdr.daddr, &buf, len, mark);
+			}
+		}
+	}
+	enumerator->destroy(enumerator);
+
+	if (origin)
+	{
+		/* forward broadcast/multicast from client to network */
+		DBG2(DBG_NET, "forwarding a %H %scast from peer %H to internal network",
+			 dst, type, src);
+		addr.sll_ifindex = this->kernel.ifindex;
+		send_net(this, &addr, &buf, len);
+	}
+
+	dst->destroy(dst);
+	src->destroy(src);
+
+	return TRUE;
+}
+
+/**
+ * Join a multicast group
+ */
+static void join_group(private_kernel_listener_t *this, char *group,
+					   struct sockaddr *addr)
+{
+	struct sockaddr_in *in;
+	struct ip_mreqn mreq;
+	host_t *host;
+
+	host = host_create_from_string(group, 0);
+	if (host)
+	{
+		memset(&mreq, 0, sizeof(mreq));
+		memcpy(&mreq.imr_multiaddr.s_addr, host->get_address(host).ptr, 4);
+		if (addr->sa_family == AF_INET)
+		{
+			in = (struct sockaddr_in*)addr;
+			memcpy(&mreq.imr_address, &in->sin_addr.s_addr,
+				   sizeof(in->sin_addr.s_addr));
+		}
+		mreq.imr_ifindex = this->ifindex;
+		if (setsockopt(this->raw, IPPROTO_IP, IP_ADD_MEMBERSHIP,
+					   &mreq, sizeof(mreq)) == -1)
+		{
+			if (errno != EADDRINUSE)
+			{
+				DBG1(DBG_NET, "forecast multicast join to %s failed: %s",
+					 group, strerror(errno));
+			}
+		}
+		else
+		{
+			DBG2(DBG_NET, "forwarding multicast group %s", group);
+		}
+		host->destroy(host);
+	}
+}
+
+/**
+ * (Re-)Join all multicast groups we want to forward
+ */
+static void join_groups(private_kernel_listener_t *this, struct sockaddr *addr)
+{
+	enumerator_t *enumerator;
+	char *groups, *group;
+	static char *def =
+		"224.0.0.1,"		/* host multicast */
+		"224.0.0.22,"		/* IGMP */
+		"224.0.0.251,"		/* mDNS */
+		"224.0.0.252,"		/* LLMNR */
+		"239.255.255.250";	/* SSDP/WS-discovery */
+
+	groups = lib->settings->get_str(lib->settings,
+									"%s.plugins.forecast.groups", def, lib->ns);
+	DBG1(DBG_CFG, "joining forecast multicast groups: %s", groups);
+	enumerator = enumerator_create_token(groups, ",", " ");
+	while (enumerator->enumerate(enumerator, &group))
+	{
+		join_group(this, group, addr);
+	}
+	enumerator->destroy(enumerator);
+}
+
+/**
+ * Attach the socket filter to the socket
+ */
+static bool attach_filter(int fd, u_int32_t broadcast)
+{
+	struct sock_filter filter_code[] = {
+		/* destination address: is ... */
+		BPF_STMT(BPF_LD+BPF_W+BPF_ABS, offsetof(struct iphdr, daddr)),
+		/* broadcast, as received from the local network */
+		BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, ntohl(broadcast), 4, 0),
+		/* broadcast, as Win7 sends them */
+		BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, 0xFFFFFFFF, 3, 0),
+		/* any multicast, 224.0.0.0/4 */
+		BPF_STMT(BPF_ALU+BPF_AND+BPF_K, 0xF0000000),
+		BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, 0xE0000000, 1, 0),
+		BPF_STMT(BPF_RET+BPF_K, 0),
+		BPF_STMT(BPF_LD+BPF_W+BPF_LEN, 0),
+		BPF_STMT(BPF_RET+BPF_A, 0),
+	};
+	struct sock_fprog filter = {
+		sizeof(filter_code) / sizeof(struct sock_filter),
+		filter_code,
+	};
+
+	if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER,
+				   &filter, sizeof(filter)) < 0)
+	{
+		DBG1(DBG_NET, "installing forecast PACKET socket filter failed: %s",
+			 strerror(errno));
+		return FALSE;
+	}
+	return TRUE;
+}
+
+/**
+ * Get the interface index of an interface name
+ */
+static int get_ifindex(private_kernel_listener_t *this, char *ifname)
+{
+	struct ifreq ifr = {};
+
+	strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
+	if (ioctl(this->raw, SIOCGIFINDEX, &ifr) == 0)
+	{
+		return ifr.ifr_ifindex;
+	}
+	return 0;
+}
+
+/**
+ * Set up the interface for broad/multicast forwarding
+ */
+static void setup_interface(private_kernel_listener_t *this)
+{
+	struct ifaddrs *addrs, *current;
+	struct sockaddr_in *in;
+	host_t *host;
+	char *name;
+
+	name = lib->settings->get_str(lib->settings,
+							"%s.plugins.forecast.interface", NULL, lib->ns);
+	if (getifaddrs(&addrs) == 0)
+	{
+		for (current = addrs; current; current = current->ifa_next)
+		{
+			if (name && !streq(name, current->ifa_name))
+			{
+				continue;
+			}
+			if (current->ifa_flags & IFF_BROADCAST &&
+				current->ifa_broadaddr &&
+				current->ifa_broadaddr->sa_family == AF_INET)
+			{
+				DBG1(DBG_NET, "using forecast interface %s", current->ifa_name);
+				this->ifindex = get_ifindex(this, current->ifa_name);
+				in = (struct sockaddr_in*)current->ifa_broadaddr;
+				attach_filter(this->pkt, in->sin_addr.s_addr);
+				join_groups(this, current->ifa_addr);
+				host = host_create_from_sockaddr(current->ifa_broadaddr);
+				if (host)
+				{
+					this->fc->set_broadcast(this->fc, host);
+					host->destroy(host);
+				}
+				break;
+			}
+		}
+	}
+	freeifaddrs(addrs);
+}
+
+METHOD(kernel_listener_t, roam, bool,
+	private_kernel_listener_t *this, bool address)
+{
+	if (address)
+	{
+		setup_interface(this);
+	}
+	return TRUE;
+}
+
+METHOD(forecast_forwarder_t, destroy, void,
+	private_forecast_forwarder_t *this)
+{
+	if (this->kernel.raw != -1)
+	{
+		close(this->kernel.raw);
+	}
+	if (this->kernel.pkt != -1)
+	{
+		lib->watcher->remove(lib->watcher, this->kernel.pkt);
+		close(this->kernel.pkt);
+	}
+	hydra->kernel_interface->remove_listener(hydra->kernel_interface,
+											 &this->kernel.listener);
+	free(this);
+}
+
+/**
+ * See header
+ */
+forecast_forwarder_t *forecast_forwarder_create(forecast_listener_t *listener)
+{
+	private_forecast_forwarder_t *this;
+	int on = 1;
+
+	INIT(this,
+		.public = {
+			.destroy = _destroy,
+		},
+		.kernel = {
+			.listener = {
+				.roam = _roam,
+			},
+			.raw = -1,
+			.pkt = -1,
+			.fc = listener,
+		},
+	);
+
+	this->kernel.pkt = socket(AF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
+	if (this->kernel.pkt == -1)
+	{
+		DBG1(DBG_NET, "opening PACKET socket failed: %s", strerror(errno));
+		destroy(this);
+		return NULL;
+	}
+	this->kernel.raw = socket(AF_INET, SOCK_RAW, IPPROTO_UDP);
+	if (this->kernel.raw == -1)
+	{
+		DBG1(DBG_NET, "opening RAW socket failed: %s", strerror(errno));
+		destroy(this);
+		return NULL;
+	}
+	if (setsockopt(this->kernel.raw, IPPROTO_IP, IP_HDRINCL,
+				   &on, sizeof(on)) == -1)
+	{
+		DBG1(DBG_NET, "forecast socket HDRINCL failed: %s", strerror(errno));
+		destroy(this);
+		return NULL;
+	}
+	if (setsockopt(this->kernel.raw, SOL_SOCKET, SO_BROADCAST,
+				   &on, sizeof(on)) == -1)
+	{
+		DBG1(DBG_NET, "forecast socket BROADCAST failed: %s", strerror(errno));
+		destroy(this);
+		return NULL;
+	}
+
+	setup_interface(&this->kernel);
+
+	hydra->kernel_interface->add_listener(hydra->kernel_interface,
+										  &this->kernel.listener);
+
+	lib->watcher->add(lib->watcher, this->kernel.pkt, WATCHER_READ,
+					  (watcher_cb_t)receive_casts, this);
+
+	return &this->public;
+}

src/libcharon/plugins/forecast/forecast_forwarder.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2010-2014 Martin Willi
+ * Copyright (C) 2010-2014 revosec AG
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+/**
+ * @defgroup forecast_forwarder forecast_forwarder
+ * @{ @ingroup forecast
+ */
+
+#ifndef FORECAST_FORWARDER_H_
+#define FORECAST_FORWARDER_H_
+
+#include "forecast_listener.h"
+
+typedef struct forecast_forwarder_t forecast_forwarder_t;
+
+/**
+ * Broadcast/Multicast sniffer and forwarder.
+ */
+struct forecast_forwarder_t {
+
+	/**
+	 * Destroy a forecast_forwarder_t.
+	 */
+	void (*destroy)(forecast_forwarder_t *this);
+};
+
+/**
+ * Create a forecast_forwarder instance.
+ *
+ * @param listener		listener to check for addresses to forward to
+ * @return				forwarder instance
+ */
+forecast_forwarder_t *forecast_forwarder_create(forecast_listener_t *listener);
+
+#endif /** FORECAST_FORWARDER_H_ @}*/

src/libcharon/plugins/forecast/forecast_listener.c

@@ -0,0 +1,680 @@
+/*
+ * Copyright (C) 2010-2014 Martin Willi
+ * Copyright (C) 2010-2014 revosec AG
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#include "forecast_listener.h"
+
+#include <errno.h>
+#include <libiptc/libiptc.h>
+#include <linux/netfilter/xt_MARK.h>
+#include <linux/netfilter/xt_esp.h>
+
+#include <daemon.h>
+#include <collections/array.h>
+#include <collections/hashtable.h>
+#include <threading/rwlock.h>
+
+typedef struct private_forecast_listener_t private_forecast_listener_t;
+
+/**
+ * Private data of an forecast_listener_t object.
+ */
+struct private_forecast_listener_t {
+
+	/**
+	 * Public forecast_listener_t interface.
+	 */
+	forecast_listener_t public;
+
+	/**
+	 * List of entries
+	 */
+	linked_list_t *entries;
+
+	/**
+	 * RWlock for IP list
+	 */
+	rwlock_t *lock;
+
+	/**
+	 * Configs we do reinjection
+	 */
+	char *reinject_configs;
+
+	/**
+	 * Broadcast address on LAN interface, network order
+	 */
+	u_int32_t broadcast;
+};
+
+/**
+ * Hashtable entry
+ */
+typedef struct {
+	/** local traffic selectors */
+	array_t *lts;
+	/** remote traffic selectors */
+	array_t *rts;
+	/** firewall mark used by CHILD_SA */
+	u_int mark;
+	/** local IKE_SA endpoint */
+	host_t *lhost;
+	/** remote IKE_SA endpoint */
+	host_t *rhost;
+	/** inbound SPI */
+	u_int32_t spi;
+	/** use UDP encapsulation */
+	bool encap;
+	/** wheter we should allow reencapsulation of IPsec received forecasts */
+	bool reinject;
+	/** broadcast address used for that entry */
+	u_int32_t broadcast;
+} entry_t;
+
+/**
+ * Destroy an entry
+ */
+static void entry_destroy(entry_t *entry)
+{
+	if (entry)
+	{
+		entry->lhost->destroy(entry->lhost);
+		entry->rhost->destroy(entry->rhost);
+		array_destroy_offset(entry->lts, offsetof(traffic_selector_t, destroy));
+		array_destroy_offset(entry->rts, offsetof(traffic_selector_t, destroy));
+		free(entry);
+	}
+}
+
+/**
+ * Convert an (IPv4) traffic selector to an address and mask
+ */
+static bool ts2in(traffic_selector_t *ts,
+				  struct in_addr *addr, struct in_addr *mask)
+{
+	u_int8_t bits;
+	host_t *net;
+
+	if (ts->get_type(ts) == TS_IPV4_ADDR_RANGE &&
+		ts->to_subnet(ts, &net, &bits))
+	{
+		memcpy(&addr->s_addr, net->get_address(net).ptr, 4);
+		net->destroy(net);
+		mask->s_addr = htonl(0xffffffffU << (32 - bits));
+		return TRUE;
+	}
+	return FALSE;
+}
+
+/**
+ * Convert an (IPv4) host to an address with mask
+ */
+static bool host2in(host_t *host, struct in_addr *addr, struct in_addr *mask)
+{
+	if (host->get_family(host) == AF_INET)
+	{
+		memcpy(&addr->s_addr, host->get_address(host).ptr, 4);
+		mask->s_addr = ~0;
+		return TRUE;
+	}
+	return FALSE;
+}
+
+/**
+ * Add or remove a rule to/from the specified chain
+ */
+static bool manage_rule(struct iptc_handle *ipth, const char *chain,
+						bool add, struct ipt_entry *e)
+{
+	if (add)
+	{
+		if (!iptc_insert_entry(chain, e, 0, ipth))
+		{
+			DBG1(DBG_CFG, "appending %s rule failed: %s",
+				 chain, iptc_strerror(errno));
+			return FALSE;
+		}
+	}
+	else
+	{
+		if (!iptc_delete_entry(chain, e, "", ipth))
+		{
+			DBG1(DBG_CFG, "deleting %s rule failed: %s",
+				 chain, iptc_strerror(errno));
+			return FALSE;
+		}
+	}
+	return TRUE;
+}
+
+/**
+ * Add rule marking UDP-encapsulated ESP packets to match the correct policy
+ */
+static bool manage_pre_esp_in_udp(struct iptc_handle *ipth,
+								  entry_t *entry, bool add)
+{
+	struct {
+		struct ipt_entry e;
+		struct ipt_entry_match m;
+		struct xt_udp udp;
+		struct ipt_entry_target t;
+		struct xt_mark_tginfo2 tm;
+	} ipt = {
+		.e  = {
+			.target_offset = XT_ALIGN(sizeof(ipt.e) + sizeof(ipt.m) +
+									  sizeof(ipt.udp)),
+			.next_offset = sizeof(ipt),
+			.ip = {
+				.proto = IPPROTO_UDP,
+			},
+		},
+		.m = {
+			.u = {
+				.user = {
+					.match_size = XT_ALIGN(sizeof(ipt.m) + sizeof(ipt.udp)),
+					.name = "udp",
+				},
+			},
+		},
+		.udp = {
+			.spts = {
+				entry->rhost->get_port(entry->rhost),
+				entry->rhost->get_port(entry->lhost)
+			},
+			.dpts = {
+				entry->lhost->get_port(entry->lhost),
+				entry->lhost->get_port(entry->lhost)
+			},
+		},
+		.t = {
+			.u = {
+				.user = {
+					.target_size = XT_ALIGN(sizeof(ipt.t) + sizeof(ipt.tm)),
+					.name = "MARK",
+					.revision = 2,
+				},
+			},
+		},
+		.tm = {
+			.mark = entry->mark,
+			.mask = ~0,
+		},
+	};
+
+	if (!host2in(entry->lhost, &ipt.e.ip.dst, &ipt.e.ip.dmsk) ||
+		!host2in(entry->rhost, &ipt.e.ip.src, &ipt.e.ip.smsk))
+	{
+		return FALSE;
+	}
+	return manage_rule(ipth, "PREROUTING", add, &ipt.e);
+}
+
+/**
+ * Add rule marking non-encapsulated ESP packets to match the correct policy
+ */
+static bool manage_pre_esp(struct iptc_handle *ipth, entry_t *entry, bool add)
+{
+	struct {
+		struct ipt_entry e;
+		struct ipt_entry_match m;
+		struct xt_esp esp;
+		struct ipt_entry_target t;
+		struct xt_mark_tginfo2 tm;
+	} ipt = {
+		.e  = {
+			.target_offset = XT_ALIGN(sizeof(ipt.e) + sizeof(ipt.m) +
+									  sizeof(ipt.esp)),
+			.next_offset = sizeof(ipt),
+			.ip = {
+				.proto = IPPROTO_ESP,
+			},
+		},
+		.m = {
+			.u = {
+				.user = {
+					.match_size = XT_ALIGN(sizeof(ipt.m) + sizeof(ipt.esp)),
+					.name = "esp",
+				},
+			},
+		},
+		.esp = {
+			.spis = { htonl(entry->spi), htonl(entry->spi) },
+		},
+		.t = {
+			.u = {
+				.user = {
+					.target_size = XT_ALIGN(sizeof(ipt.t) + sizeof(ipt.tm)),
+					.name = "MARK",
+					.revision = 2,
+				},
+			},
+		},
+		.tm = {
+			.mark = entry->mark,
+			.mask = ~0,
+		},
+	};
+
+	if (!host2in(entry->lhost, &ipt.e.ip.dst, &ipt.e.ip.dmsk) ||
+		!host2in(entry->rhost, &ipt.e.ip.src, &ipt.e.ip.smsk))
+	{
+		return FALSE;
+	}
+	return manage_rule(ipth, "PREROUTING", add, &ipt.e);
+}
+
+/**
+ * Add rule marking ESP packets to match the correct policy
+ */
+static bool manage_pre(struct iptc_handle *ipth, entry_t *entry, bool add)
+{
+	if (entry->encap)
+	{
+		return manage_pre_esp_in_udp(ipth, entry, add);
+	}
+	return manage_pre_esp(ipth, entry, add);
+}
+
+/**
+ * Add rule handling outbound traffic to use correct mark
+ */
+static bool manage_out(struct iptc_handle *ipth, entry_t *entry, bool add)
+{
+	struct {
+		struct ipt_entry e;
+		struct ipt_entry_target t;
+		struct xt_mark_tginfo2 m;
+	} ipt = {
+		.e  = {
+			.target_offset = XT_ALIGN(sizeof(ipt.e)),
+			.next_offset = sizeof(ipt),
+		},
+		.t = {
+			.u.user.target_size = XT_ALIGN(sizeof(ipt.t) + sizeof(ipt.m)),
+			.u.user.name = "MARK",
+			.u.user.revision = 2,
+		},
+		.m = {
+			.mark = entry->mark,
+			.mask = ~0,
+		},
+	};
+	enumerator_t *enumerator;
+	traffic_selector_t *ts;
+
+	enumerator = array_create_enumerator(entry->rts);
+	while (enumerator->enumerate(enumerator, &ts))
+	{
+		if (!ts2in(ts, &ipt.e.ip.dst, &ipt.e.ip.dmsk))
+		{
+			continue;
+		}
+		if (ipt.e.ip.dst.s_addr == 0xffffffff ||
+			ipt.e.ip.dst.s_addr == entry->broadcast ||
+			memeq(&ipt.e.ip.dst.s_addr, "\xe0", 1))
+		{
+			/* skip broadcast/multicast selectors, they are shared and the mark
+			 * is set by the socket we use for reinjection */
+			continue;
+		}
+		if (!manage_rule(ipth, "PREROUTING", add, &ipt.e) ||
+			!manage_rule(ipth, "OUTPUT", add, &ipt.e))
+		{
+			enumerator->destroy(enumerator);
+			return FALSE;
+		}
+	}
+	enumerator->destroy(enumerator);
+
+	return TRUE;
+}
+
+/**
+ * Check if config is whitelisted to reinject traffic
+ */
+static bool is_reinject_config(private_forecast_listener_t *this, char *name)
+{
+	enumerator_t *enumerator;
+	bool reinject = FALSE;
+	char *token;
+
+	enumerator = enumerator_create_token(this->reinject_configs, ",", " ");
+	while (enumerator->enumerate(enumerator, &token))
+	{
+		if (streq(token, name))
+		{
+			reinject = TRUE;
+			break;
+		}
+	}
+	enumerator->destroy(enumerator);
+
+	return reinject;
+}
+
+/**
+ * Add rules and entry for given CHILD_SA
+ */
+static bool add_entry(private_forecast_listener_t *this,
+					  struct iptc_handle *ipth, host_t *lhost, host_t *rhost,
+					  child_sa_t *child_sa, bool encap)
+{
+	enumerator_t *enumerator;
+	traffic_selector_t *ts;
+	entry_t *entry;
+
+	INIT(entry,
+		.lts = array_create(0, 0),
+		.rts = array_create(0, 0),
+		.lhost = lhost->clone(lhost),
+		.rhost = rhost->clone(rhost),
+		.spi = child_sa->get_spi(child_sa, TRUE),
+		.encap = encap,
+		.mark = child_sa->get_mark(child_sa, TRUE).value,
+		.reinject = is_reinject_config(this, child_sa->get_name(child_sa)),
+		.broadcast = this->broadcast,
+	);
+
+	enumerator = child_sa->create_ts_enumerator(child_sa, TRUE);
+	while (enumerator->enumerate(enumerator, &ts))
+	{
+		array_insert(entry->lts, ARRAY_TAIL, ts->clone(ts));
+	}
+	enumerator->destroy(enumerator);
+
+	enumerator = child_sa->create_ts_enumerator(child_sa, FALSE);
+	while (enumerator->enumerate(enumerator, &ts))
+	{
+		array_insert(entry->rts, ARRAY_TAIL, ts->clone(ts));
+	}
+	enumerator->destroy(enumerator);
+
+	if (manage_pre(ipth, entry, TRUE) &&
+		manage_out(ipth, entry, TRUE))
+	{
+		this->lock->write_lock(this->lock);
+		this->entries->insert_last(this->entries, entry);
+		this->lock->unlock(this->lock);
+		return TRUE;
+	}
+	entry_destroy(entry);
+	return FALSE;
+}
+
+/**
+ * Remove an entry and rules for a given mark
+ */
+static bool remove_entry(private_forecast_listener_t *this,
+						 struct iptc_handle *ipth, child_sa_t *child_sa)
+{
+	enumerator_t *enumerator;
+	entry_t *entry;
+	bool done = FALSE;
+
+	this->lock->write_lock(this->lock);
+	enumerator = this->entries->create_enumerator(this->entries);
+	while (enumerator->enumerate(enumerator, &entry))
+	{
+		if (entry->mark == child_sa->get_mark(child_sa, TRUE).value)
+		{
+			this->entries->remove_at(this->entries, enumerator);
+			if (manage_pre(ipth, entry, FALSE) &&
+				manage_out(ipth, entry, FALSE))
+			{
+				done = TRUE;
+			}
+			entry_destroy(entry);
+			break;
+		}
+	}
+	enumerator->destroy(enumerator);
+	this->lock->unlock(this->lock);
+
+	return done;
+}
+
+/**
+ * Initialize iptables handle, log error
+ */
+static struct iptc_handle* init_handle()
+{
+	struct iptc_handle *ipth;
+
+	ipth = iptc_init("mangle");
+	if (ipth)
+	{
+		return ipth;
+	}
+	DBG1(DBG_CFG, "initializing iptables failed: %s", iptc_strerror(errno));
+	return NULL;
+}
+
+/**
+ * Commit iptables rules, log error
+ */
+static bool commit_handle(struct iptc_handle *ipth)
+{
+	if (iptc_commit(ipth))
+	{
+		return TRUE;
+	}
+	DBG1(DBG_CFG, "forecast iptables commit failed: %s", iptc_strerror(errno));
+	return FALSE;
+}
+
+/**
+ * Check if we should handle the given CHILD_SA
+ */
+static bool handle_sa(child_sa_t *child_sa)
+{
+	return child_sa->get_mark(child_sa, TRUE).value &&
+		   child_sa->get_mark(child_sa, FALSE).value;
+}
+
+METHOD(listener_t, child_updown, bool,
+	private_forecast_listener_t *this, ike_sa_t *ike_sa, child_sa_t *child_sa,
+	bool up)
+{
+	struct iptc_handle *ipth;
+	host_t *lhost, *rhost;
+	bool encap;
+
+	lhost = ike_sa->get_my_host(ike_sa);
+	rhost = ike_sa->get_other_host(ike_sa);
+	encap = child_sa->has_encap(child_sa);
+
+	if (handle_sa(child_sa))
+	{
+		ipth = init_handle();
+		if (ipth)
+		{
+			if (up)
+			{
+				if (add_entry(this, ipth, lhost, rhost, child_sa, encap))
+				{
+					commit_handle(ipth);
+				}
+			}
+			else
+			{
+				if (remove_entry(this, ipth, child_sa))
+				{
+					commit_handle(ipth);
+				}
+			}
+			iptc_free(ipth);
+		}
+	}
+	return TRUE;
+}
+
+METHOD(listener_t, child_rekey, bool,
+	private_forecast_listener_t *this, ike_sa_t *ike_sa,
+	child_sa_t *old, child_sa_t *new)
+{
+	struct iptc_handle *ipth;;
+	host_t *lhost, *rhost;
+
+	lhost = ike_sa->get_my_host(ike_sa);
+	rhost = ike_sa->get_other_host(ike_sa);
+
+	if (handle_sa(old))
+	{
+		ipth = init_handle();
+		if (ipth)
+		{
+			if (remove_entry(this, ipth, old) &&
+				add_entry(this, ipth, lhost, rhost, new, new->has_encap(new)))
+			{
+				commit_handle(ipth);
+			}
+			iptc_free(ipth);
+		}
+	}
+	return TRUE;
+}
+
+METHOD(listener_t, ike_update, bool,
+	private_forecast_listener_t *this, ike_sa_t *ike_sa,
+	bool local, host_t *new)
+{
+	struct iptc_handle *ipth;
+	enumerator_t *enumerator;
+	child_sa_t *child_sa;
+	host_t *lhost, *rhost;
+	bool encap;
+
+	if (local)
+	{
+		lhost = new;
+		rhost = ike_sa->get_other_host(ike_sa);
+	}
+	else
+	{
+		lhost = ike_sa->get_my_host(ike_sa);
+		rhost = new;
+	}
+	/* during ike_update(), has_encap() on the CHILD_SA has not yet been
+	 * updated, but shows the old state. */
+	encap = ike_sa->has_condition(ike_sa, COND_NAT_ANY);
+
+	enumerator = ike_sa->create_child_sa_enumerator(ike_sa);
+	while (enumerator->enumerate(enumerator, &child_sa))
+	{
+		if (handle_sa(child_sa))
+		{
+			ipth = init_handle();
+			if (ipth)
+			{
+				if (remove_entry(this, ipth, child_sa) &&
+					add_entry(this, ipth, lhost, rhost, child_sa, encap))
+				{
+					commit_handle(ipth);
+				}
+				iptc_free(ipth);
+			}
+		}
+	}
+	enumerator->destroy(enumerator);
+
+	return TRUE;
+}
+
+/**
+ * Filter to map entries to ts/mark
+ */
+static bool ts_filter(entry_t *entry, traffic_selector_t **ts,
+					  traffic_selector_t **out, void *dummy, u_int32_t *mark,
+					  void *dummy2, bool *reinject)
+{
+	*out = *ts;
+	*mark = entry->mark;
+	*reinject = entry->reinject;
+	return TRUE;
+}
+
+/**
+ * Create inner enumerator over local traffic selectors
+ */
+static enumerator_t* create_inner_local(entry_t *entry, rwlock_t *lock)
+{
+	return enumerator_create_filter(array_create_enumerator(entry->lts),
+									(void*)ts_filter, entry, NULL);
+}
+
+/**
+ * Create inner enumerator over remote traffic selectors
+ */
+static enumerator_t* create_inner_remote(entry_t *entry, rwlock_t *lock)
+{
+	return enumerator_create_filter(array_create_enumerator(entry->rts),
+									(void*)ts_filter, entry, NULL);
+}
+
+METHOD(forecast_listener_t, create_enumerator, enumerator_t*,
+	private_forecast_listener_t *this, bool local)
+{
+	this->lock->read_lock(this->lock);
+	return enumerator_create_nested(
+					this->entries->create_enumerator(this->entries),
+					(void*)(local ? create_inner_local : create_inner_remote),
+					this->lock, (void*)this->lock->unlock);
+}
+
+METHOD(forecast_listener_t, set_broadcast, void,
+	private_forecast_listener_t *this, host_t *bcast)
+{
+	if (bcast->get_family(bcast) == AF_INET)
+	{
+		struct sockaddr_in *in;
+
+		in = bcast->get_sockaddr(bcast);
+		this->broadcast = in->sin_addr.s_addr;
+	}
+}
+
+METHOD(forecast_listener_t, destroy, void,
+	private_forecast_listener_t *this)
+{
+	this->entries->destroy(this->entries);
+	this->lock->destroy(this->lock);
+	free(this);
+}
+
+/**
+ * See header
+ */
+forecast_listener_t *forecast_listener_create()
+{
+	private_forecast_listener_t *this;
+
+	INIT(this,
+		.public = {
+			.listener = {
+				.ike_update = _ike_update,
+				.child_updown = _child_updown,
+				.child_rekey = _child_rekey,
+			},
+			.create_enumerator = _create_enumerator,
+			.set_broadcast = _set_broadcast,
+			.destroy = _destroy,
+		},
+		.entries = linked_list_create(),
+		.lock = rwlock_create(RWLOCK_TYPE_DEFAULT),
+		.reinject_configs = lib->settings->get_str(lib->settings,
+								"%s.plugins.forecast.reinject", "", lib->ns),
+	);
+
+	return &this->public;
+}

src/libcharon/plugins/forecast/forecast_listener.h

@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2010-2014 Martin Willi
+ * Copyright (C) 2010-2014 revosec AG
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+/**
+ * @defgroup forecast_listener forecast_listener
+ * @{ @ingroup forecast
+ */
+
+#ifndef FORECAST_LISTENER_H_
+#define FORECAST_LISTENER_H_
+
+#include <bus/listeners/listener.h>
+
+typedef struct forecast_listener_t forecast_listener_t;
+
+/**
+ * Listener to register the set of IPs we forward received multi/broadcasts to.
+ */
+struct forecast_listener_t {
+
+	/**
+	 * Implements listener_t interface.
+	 */
+	listener_t listener;
+
+	/**
+	 * Create an enumerator over active tunnels.
+	 *
+	 * The enumerator enumerates over local or remote traffic selectors,
+	 * associated firewall marks and if decasulated packets should get
+	 * reinjected into other tunnels.
+	 *
+	 * @param local		TRUE to enumerate local, FALSE to enumerate remote TS
+	 * @return			enumerator over (traffic_selector_t*, u_int, bool)
+	 */
+	enumerator_t* (*create_enumerator)(forecast_listener_t *this, bool local);
+
+	/**
+	 * Set the broadcast address of the LAN interface.
+	 *
+	 * @param bcast		broadcast address
+	 */
+	void (*set_broadcast)(forecast_listener_t *this, host_t *bcast);
+
+	/**
+	 * Destroy a forecast_listener_t.
+	 */
+	void (*destroy)(forecast_listener_t *this);
+};
+
+/**
+ * Create a forecast_listener instance.
+ */
+forecast_listener_t *forecast_listener_create();
+
+#endif /** FORECAST_LISTENER_H_ @}*/

src/libcharon/plugins/forecast/forecast_plugin.c

@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2010-2014 Martin Willi
+ * Copyright (C) 2010-2014 revosec AG
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#include "forecast_plugin.h"
+#include "forecast_listener.h"
+#include "forecast_forwarder.h"
+
+#include <daemon.h>
+
+typedef struct private_forecast_plugin_t private_forecast_plugin_t;
+
+/**
+ * Private data of forecast plugin
+ */
+struct private_forecast_plugin_t {
+
+	/**
+	 * implements plugin interface
+	 */
+	forecast_plugin_t public;
+
+	/**
+	 * Listener registering active tunnels
+	 */
+	forecast_listener_t *listener;
+
+	/**
+	 * Broadcast/Multicast sniffer and forwarder
+	 */
+	forecast_forwarder_t *forwarder;
+};
+
+METHOD(plugin_t, get_name, char*,
+	private_forecast_plugin_t *this)
+{
+	return "forecast";
+}
+
+/**
+ * Register plugin features
+ */
+static bool register_forecast(private_forecast_plugin_t *this,
+							  plugin_feature_t *feature, bool reg, void *data)
+{
+	if (reg)
+	{
+		this->forwarder = forecast_forwarder_create(this->listener);
+		if (!this->forwarder)
+		{
+			return FALSE;
+		}
+		charon->bus->add_listener(charon->bus, &this->listener->listener);
+	}
+	else
+	{
+		charon->bus->remove_listener(charon->bus, &this->listener->listener);
+		this->forwarder->destroy(this->forwarder);
+	}
+	return TRUE;
+}
+
+METHOD(plugin_t, get_features, int,
+	private_forecast_plugin_t *this, plugin_feature_t *features[])
+{
+	static plugin_feature_t f[] = {
+		PLUGIN_CALLBACK((plugin_feature_callback_t)register_forecast, NULL),
+			PLUGIN_PROVIDE(CUSTOM, "forecast"),
+	};
+	*features = f;
+	return countof(f);
+}
+
+METHOD(plugin_t, destroy, void,
+	private_forecast_plugin_t *this)
+{
+	this->listener->destroy(this->listener);
+	free(this);
+}
+
+/**
+ * Plugin constructor
+ */
+plugin_t *forecast_plugin_create()
+{
+	private_forecast_plugin_t *this;
+
+	if (!lib->caps->keep(lib->caps, CAP_NET_RAW))
+	{
+		DBG1(DBG_NET, "forecast plugin requires CAP_NET_RAW capability");
+		return NULL;
+	}
+
+	INIT(this,
+		.public = {
+			.plugin = {
+				.get_name = _get_name,
+				.get_features = _get_features,
+				.reload = (void*)return_false,
+				.destroy = _destroy,
+			},
+		},
+		.listener = forecast_listener_create(),
+	);
+
+	return &this->public.plugin;
+}

src/libcharon/plugins/forecast/forecast_plugin.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2010-2014 Martin Willi
+ * Copyright (C) 2010-2014 revosec AG
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+/**
+ * @defgroup forecast forecast
+ * @ingroup cplugins
+ *
+ * @defgroup forecast_plugin forecast_plugin
+ * @{ @ingroup forecast
+ */
+
+#ifndef FORECAST_PLUGIN_H_
+#define FORECAST_PLUGIN_H_
+
+#include <plugins/plugin.h>
+
+typedef struct forecast_plugin_t forecast_plugin_t;
+
+/**
+ * Broadcast/Multicast forwarding plugin.
+ */
+struct forecast_plugin_t {
+
+	/**
+	 * Implements plugin interface.
+	 */
+	plugin_t plugin;
+};
+
+#endif /** FORECAST_PLUGIN_H_ @}*/

testing/scripts/recipes/013_strongswan.mk

@@ -71,6 +71,7 @@ CONFIG_OPTS = \
 	--enable-dhcp \
 	--enable-farp \
 	--enable-connmark \
+	--enable-forecast \
 	--enable-addrblock \
 	--enable-ctr \
 	--enable-ccm \

testing/tests/ikev2/forecast/description.txt

@@ -0,0 +1,8 @@
+The roadwarriors <b>carol</b> and <b>dave</b> set up a connection each to
+gateway <b>moon</b> and request a <b>virtual IP</b>. <b>moon</b> negotiates
+broadcast and multicast traffic selectors with the clients, and uses
+<i>%unique</i> marks to avoid any policy conflicts. The enabled <i>forecast</i>
+plugin on <b>moon</b> installs the required Netfilter rules to make use of these
+policies, and additionally starts forwarding broadcast and multicast packets
+between the clients.<br/>
+To test forwarding, the hosts send multicast and broadcast ping messages.

testing/tests/ikev2/forecast/evaltest.dat

@@ -0,0 +1,20 @@
+carol::ipsec status 2> /dev/null::home.*ESTABLISHED.*[email protected].*moon.strongswan.org::YES
+carol::ipsec status 2> /dev/null::home.*INSTALLED, TUNNEL::YES
+dave:: ipsec status 2> /dev/null::home.*ESTABLISHED.*[email protected].*moon.strongswan.org::YES
+dave:: ipsec status 2> /dev/null::home.*INSTALLED, TUNNEL::YES
+moon:: ipsec status 2> /dev/null::rw.*ESTABLISHED.*moon.strongswan.org.*[email protected]::YES
+moon:: ipsec status 2> /dev/null::rw.*ESTABLISHED.*moon.strongswan.org.*[email protected]::YES
+moon:: ipsec status 2> /dev/null::rw.*INSTALLED, TUNNEL, reqid 1::YES
+moon:: ipsec status 2> /dev/null::rw.*INSTALLED, TUNNEL, reqid 2::YES
+alice::ping -W 1 -c 1 239.0.0.1 2>&1> /dev/null
+carol::ping -W 1 -c 1 239.0.0.2 2>&1> /dev/null
+dave::ping -W 1 -c 1 239.0.0.3 2>&1> /dev/null
+carol::ping -W 1 -c 1 -b 10.1.255.255 2>&1> /dev/null
+dave::ping -W 1 -c 1 -b 10.1.255.255 2>&1> /dev/null
+moon::iptables -t mangle -L -n -v
+carol::tcpdump::IP alice.strongswan.org > 239.0.0.1: ICMP echo request::YES
+dave::tcpdump::IP alice.strongswan.org > 239.0.0.1: ICMP echo request::YES
+carol::tcpdump::IP 10.1.0.130 > 239.0.0.3: ICMP echo request::YES
+dave::tcpdump::IP 10.1.0.129 > 239.0.0.2: ICMP echo request::YES
+carol::tcpdump::IP 10.1.0.130 > 10.1.255.255: ICMP echo request::YES
+dave::tcpdump::IP 10.1.0.129 > 10.1.255.255: ICMP echo request::YES

testing/tests/ikev2/forecast/hosts/carol/etc/ipsec.conf

@@ -0,0 +1,21 @@
+# /etc/ipsec.conf - strongSwan IPsec configuration file
+
+config setup
+
+conn %default
+	ikelifetime=60m
+	keylife=20m
+	rekeymargin=3m
+	keyingtries=1
+	keyexchange=ikev2
+
+conn home
+	left=PH_IP_CAROL
+	leftsourceip=%config
+	leftsubnet=0.0.0.0/0
+	leftcert=carolCert.pem
+	[email protected]
+	right=PH_IP_MOON
+	rightsubnet=0.0.0.0/0
+	[email protected]
+	auto=add

testing/tests/ikev2/forecast/hosts/carol/etc/strongswan.conf

@@ -0,0 +1,5 @@
+# /etc/strongswan.conf - strongSwan configuration file
+
+charon {
+  load = aes des sha1 sha2 md5 pem pkcs1 gmp random nonce x509 curl revocation hmac xcbc stroke kernel-netlink socket-default updown resolve
+}

testing/tests/ikev2/forecast/hosts/dave/etc/ipsec.conf

@@ -0,0 +1,21 @@
+# /etc/ipsec.conf - strongSwan IPsec configuration file
+
+config setup
+
+conn %default
+	ikelifetime=60m
+	keylife=20m
+	rekeymargin=3m
+	keyingtries=1
+	keyexchange=ikev2
+
+conn home
+	left=PH_IP_DAVE
+	leftsourceip=%config
+	leftsubnet=0.0.0.0/0
+	leftcert=daveCert.pem
+	[email protected]
+	right=PH_IP_MOON
+	rightsubnet=0.0.0.0/0
+	[email protected]
+	auto=add

testing/tests/ikev2/forecast/hosts/dave/etc/strongswan.conf

@@ -0,0 +1,5 @@
+# /etc/strongswan.conf - strongSwan configuration file
+
+charon {
+  load = aes des sha1 sha2 md5 pem pkcs1 gmp random nonce x509 curl revocation hmac xcbc stroke kernel-netlink socket-default updown resolve
+}

testing/tests/ikev2/forecast/hosts/moon/etc/ipsec.conf

@@ -0,0 +1,22 @@
+# /etc/ipsec.conf - strongSwan IPsec configuration file
+
+config setup
+
+conn %default
+	ikelifetime=60m
+	keylife=20m
+	rekeymargin=3m
+	keyingtries=1
+	keyexchange=ikev2
+
+conn rw
+	left=PH_IP_MOON
+	leftcert=moonCert.pem
+	[email protected]
+	leftsubnet=10.1.0.0/16,224.0.0.0/4
+	right=%any
+	rightid=*@strongswan.org
+	rightsourceip=10.1.0.128/26
+	rightsubnet=%dynamic,224.0.0.0/4,10.1.255.255
+	mark=%unique
+	auto=add

testing/tests/ikev2/forecast/hosts/moon/etc/strongswan.conf

@@ -0,0 +1,16 @@
+# /etc/strongswan.conf - strongSwan configuration file
+
+charon {
+  load = aes des sha1 sha2 md5 pem pkcs1 gmp random nonce x509 curl revocation hmac xcbc stroke kernel-netlink socket-default updown attr forecast
+  syslog {
+    daemon {
+      net = 2
+    }
+  }
+  plugins {
+    forecast {
+      interface = eth1
+      reinject = rw
+    }
+  }
+}

testing/tests/ikev2/forecast/posttest.dat

@@ -0,0 +1,6 @@
+moon::ipsec stop
+carol::ipsec stop
+dave::ipsec stop
+moon::iptables-restore < /etc/iptables.flush
+carol::iptables-restore < /etc/iptables.flush
+dave::iptables-restore < /etc/iptables.flush

testing/tests/ikev2/forecast/pretest.dat

@@ -0,0 +1,7 @@
+carol::ipsec start
+dave::ipsec start
+moon::ipsec start
+carol::sleep 2
+carol::ipsec up home
+dave::ipsec up home
+carol::sleep 1

testing/tests/ikev2/forecast/test.conf

@@ -0,0 +1,21 @@
+#!/bin/bash
+#
+# This configuration file provides information on the
+# guest instances used for this test
+
+# All guest instances that are required for this test
+#
+VIRTHOSTS="alice moon carol winnetou dave"
+
+# Corresponding block diagram
+#
+DIAGRAM="a-m-c-w-d.png"
+
+# Guest instances on which tcpdump is to be started
+#
+TCPDUMPHOSTS="moon carol dave"
+
+# Guest instances on which IPsec is started
+# Used for IPsec logging purposes
+#
+IPSECHOSTS="moon carol dave"