- Update to new upstream release.

2 files changed, 2309 insertions, 0 deletions

diff --git a/src/charon/kernel/kernel_interface.c b/src/charon/kernel/kernel_interface.c
new file mode 100644
index 000000000..d82783b03
--- /dev/null
+++ b/src/charon/kernel/kernel_interface.c
@@ -0,0 +1,1974 @@
+/**
+ * @file kernel_interface.c
+ *
+ * @brief Implementation of kernel_interface_t.
+ *
+ */
+
+/*
+ * Copyright (C) 2005-2007 Martin Willi
+ * Copyright (C) 2006-2007 Tobias Brunner
+ * Copyright (C) 2006-2007 Fabian Hartmann, Noah Heusser
+ * Copyright (C) 2006 Daniel Roethlisberger
+ * Copyright (C) 2005 Jan Hutter
+ * Hochschule fuer Technik Rapperswil
+ * Copyright (C) 2003 Herbert Xu.
+ * 
+ * Based on xfrm code from pluto.
+ *
+ * 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 <sys/types.h>
+#include <sys/socket.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <linux/xfrm.h>
+#include <linux/udp.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+
+#include "kernel_interface.h"
+
+#include <daemon.h>
+#include <utils/linked_list.h>
+#include <processing/jobs/delete_child_sa_job.h>
+#include <processing/jobs/rekey_child_sa_job.h>
+#include <processing/jobs/acquire_job.h>
+
+/** kernel level protocol identifiers */
+#define KERNEL_ESP 50
+#define KERNEL_AH 51
+
+/** default priority of installed policies */
+#define PRIO_LOW 3000
+#define PRIO_HIGH 2000
+
+#define BUFFER_SIZE 1024
+
+/**
+ * returns a pointer to the first rtattr following the nlmsghdr *nlh and the 
+ * 'usual' netlink data x like 'struct xfrm_usersa_info' 
+ */
+#define XFRM_RTA(nlh, x) ((struct rtattr*)(NLMSG_DATA(nlh) + NLMSG_ALIGN(sizeof(x))))
+/**
+ * returns a pointer to the next rtattr following rta.
+ * !!! do not use this to parse messages. use RTA_NEXT and RTA_OK instead !!!
+ */
+#define XFRM_RTA_NEXT(rta) ((struct rtattr*)(((char*)(rta)) + RTA_ALIGN((rta)->rta_len)))
+/**
+ * returns the total size of attached rta data 
+ * (after 'usual' netlink data x like 'struct xfrm_usersa_info') 
+ */
+#define XFRM_PAYLOAD(nlh, x) NLMSG_PAYLOAD(nlh, sizeof(x))
+
+typedef struct kernel_algorithm_t kernel_algorithm_t;
+
+/**
+ * Mapping from the algorithms defined in IKEv2 to
+ * kernel level algorithm names and their key length
+ */
+struct kernel_algorithm_t {
+	/**
+	 * Identifier specified in IKEv2
+	 */
+	int ikev2_id;
+	
+	/**
+	 * Name of the algorithm, as used as kernel identifier
+	 */
+	char *name;
+	
+	/**
+	 * Key length in bits, if fixed size
+	 */
+	u_int key_size;
+};
+#define END_OF_LIST -1
+
+/**
+ * Algorithms for encryption
+ */
+kernel_algorithm_t encryption_algs[] = {
+/*	{ENCR_DES_IV64, 	"***", 			0}, */
+	{ENCR_DES, 			"des", 			64},
+	{ENCR_3DES, 		"des3_ede",		192},
+/*	{ENCR_RC5, 			"***", 			0}, */
+/*	{ENCR_IDEA, 		"***",			0}, */
+	{ENCR_CAST, 		"cast128",		0},
+	{ENCR_BLOWFISH, 	"blowfish",		0},
+/*	{ENCR_3IDEA, 		"***",			0}, */
+/*	{ENCR_DES_IV32, 	"***",			0}, */
+	{ENCR_NULL, 		"cipher_null",	0},
+	{ENCR_AES_CBC, 		"aes",			0},
+/*	{ENCR_AES_CTR, 		"***",			0}, */
+	{END_OF_LIST, 		NULL,			0},
+};
+
+/**
+ * Algorithms for integrity protection
+ */
+kernel_algorithm_t integrity_algs[] = {
+	{AUTH_HMAC_MD5_96, 			"md5",			128},
+	{AUTH_HMAC_SHA1_96,			"sha1",			160},
+	{AUTH_HMAC_SHA2_256_128,	"sha256",		256},
+	{AUTH_HMAC_SHA2_384_192,	"sha384",		384},
+	{AUTH_HMAC_SHA2_512_256,	"sha512",		512},
+/*	{AUTH_DES_MAC,				"***",			0}, */
+/*	{AUTH_KPDK_MD5,				"***",			0}, */
+	{AUTH_AES_XCBC_96,			"xcbc(aes)",	128},
+	{END_OF_LIST, 				NULL,			0},
+};
+
+/**
+ * Look up a kernel algorithm name and its key size
+ */
+char* lookup_algorithm(kernel_algorithm_t *kernel_algo, 
+					   algorithm_t *ikev2_algo, u_int *key_size)
+{
+	while (kernel_algo->ikev2_id != END_OF_LIST)
+	{
+		if (ikev2_algo->algorithm == kernel_algo->ikev2_id)
+		{
+			/* match, evaluate key length */
+			if (ikev2_algo->key_size)
+			{	/* variable length */
+				*key_size = ikev2_algo->key_size;
+			}
+			else
+			{	/* fixed length */
+				*key_size = kernel_algo->key_size;
+			}
+			return kernel_algo->name;
+		}
+		kernel_algo++;
+	}
+	return NULL;	
+}
+
+typedef struct route_entry_t route_entry_t;
+
+/**
+ * installed routing entry
+ */
+struct route_entry_t {
+
+	/** Index of the interface the route is bound to */
+	int if_index;
+
+	/** Source ip of the route */
+	host_t *src_ip;
+	
+	/** gateway for this route */
+	host_t *gateway;
+
+	/** Destination net */
+	chunk_t dst_net;
+
+	/** Destination net prefixlen */
+	u_int8_t prefixlen;
+};
+
+/**
+ * destroy an route_entry_t object
+ */
+static void route_entry_destroy(route_entry_t *this)
+{
+	this->src_ip->destroy(this->src_ip);
+	this->gateway->destroy(this->gateway);
+	chunk_free(&this->dst_net);
+	free(this);
+}
+
+typedef struct policy_entry_t policy_entry_t;
+
+/**
+ * installed kernel policy.
+ */
+struct policy_entry_t {
+	
+	/** direction of this policy: in, out, forward */
+	u_int8_t direction;
+	
+	/** reqid of the policy */
+	u_int32_t reqid;
+	
+	/** parameters of installed policy */
+	struct xfrm_selector sel;
+	
+	/** associated route installed for this policy */
+	route_entry_t *route;
+	
+	/** by how many CHILD_SA's this policy is used */
+	u_int refcount;
+};
+
+typedef struct vip_entry_t vip_entry_t;
+
+/**
+ * Installed virtual ip
+ */
+struct vip_entry_t {
+	/** Index of the interface the ip is bound to */
+	u_int8_t if_index;
+	
+	/** The ip address */
+	host_t *ip;
+	
+	/** Number of times this IP is used */
+	u_int refcount;
+};
+
+/**
+ * destroy a vip_entry_t object
+ */
+static void vip_entry_destroy(vip_entry_t *this)
+{
+	this->ip->destroy(this->ip);
+	free(this);
+}
+
+typedef struct address_entry_t address_entry_t;
+
+/**
+ * an address found on the system, containg address and interface info 
+ */
+struct address_entry_t {
+
+	/** address of this entry */
+	host_t *host;
+	
+	/** interface index */
+	int ifindex;
+	
+	/** name of the index */
+	char ifname[IFNAMSIZ];
+};
+
+/**
+ * destroy an address entry
+ */
+static void address_entry_destroy(address_entry_t *this)
+{
+	this->host->destroy(this->host);
+	free(this);
+}
+
+typedef struct private_kernel_interface_t private_kernel_interface_t;
+
+/**
+ * Private variables and functions of kernel_interface class.
+ */
+struct private_kernel_interface_t {
+	/**
+	 * Public part of the kernel_interface_t object.
+	 */
+	kernel_interface_t public;
+	
+	/**
+	 * List of installed policies (kernel_entry_t)
+	 */
+	linked_list_t *policies;
+	
+	/**
+	 * Mutex locks access to policies
+	 */
+	pthread_mutex_t policies_mutex;
+	
+	/**
+	 * List of installed virtual IPs. (vip_entry_t)
+	 */
+	linked_list_t *vips;
+	
+	/**
+	 * Mutex to lock access to vips.
+	 */
+	pthread_mutex_t vips_mutex;
+	
+	/**
+	 * netlink xfrm socket to receive acquire and expire events
+	 */
+	int socket_xfrm_events;
+	
+	/**
+	 * Netlink xfrm socket (IPsec)
+	 */
+	int socket_xfrm;
+	
+	/**
+	 * Netlink rt socket (routing)
+	 */
+	int socket_rt;
+	
+	/**
+	 * Thread receiving events from kernel
+	 */
+	pthread_t event_thread;
+};
+
+/**
+ * convert a host_t to a struct xfrm_address
+ */
+static void host2xfrm(host_t *host, xfrm_address_t *xfrm)
+{
+	chunk_t chunk = host->get_address(host);
+	memcpy(xfrm, chunk.ptr, min(chunk.len, sizeof(xfrm_address_t)));	
+}
+
+/**
+ * convert a traffic selector address range to subnet and its mask.
+ */
+static void ts2subnet(traffic_selector_t* ts, 
+					  xfrm_address_t *net, u_int8_t *mask)
+{
+	/* there is no way to do this cleanly, as the address range may
+	 * be anything else but a subnet. We use from_addr as subnet 
+	 * and try to calculate a usable subnet mask.
+	 */
+	int byte, bit;
+	bool found = FALSE;
+	chunk_t from, to;
+	size_t size = (ts->get_type(ts) == TS_IPV4_ADDR_RANGE) ? 4 : 16;
+	
+	from = ts->get_from_address(ts);
+	to = ts->get_to_address(ts);
+	
+	*mask = (size * 8);
+	/* go trough all bits of the addresses, beginning in the front.
+	 * as long as they are equal, the subnet gets larger
+	 */
+	for (byte = 0; byte < size; byte++)
+	{
+		for (bit = 7; bit >= 0; bit--)
+		{
+			if ((1<<bit & from.ptr[byte]) != (1<<bit & to.ptr[byte]))
+			{
+				*mask = ((7 - bit) + (byte * 8));
+				found = TRUE;
+				break;
+			}
+		}
+		if (found)
+		{
+			break;
+		}
+	}
+	memcpy(net, from.ptr, from.len);
+	chunk_free(&from);
+	chunk_free(&to);
+}
+
+/**
+ * convert a traffic selector port range to port/portmask
+ */
+static void ts2ports(traffic_selector_t* ts, 
+					 u_int16_t *port, u_int16_t *mask)
+{
+	/* linux does not seem to accept complex portmasks. Only
+	 * any or a specific port is allowed. We set to any, if we have
+	 * a port range, or to a specific, if we have one port only.
+	 */
+	u_int16_t from, to;
+	
+	from = ts->get_from_port(ts);
+	to = ts->get_to_port(ts);
+	
+	if (from == to)
+	{
+		*port = htons(from);
+		*mask = ~0;
+	}
+	else
+	{
+		*port = 0;
+		*mask = 0;
+	}
+}
+
+/**
+ * convert a pair of traffic_selectors to a xfrm_selector
+ */
+static struct xfrm_selector ts2selector(traffic_selector_t *src, 
+										traffic_selector_t *dst)
+{
+	struct xfrm_selector sel;
+
+	memset(&sel, 0, sizeof(sel));
+	sel.family = src->get_type(src) == TS_IPV4_ADDR_RANGE ? AF_INET : AF_INET6;
+	/* src or dest proto may be "any" (0), use more restrictive one */
+	sel.proto = max(src->get_protocol(src), dst->get_protocol(dst));
+	ts2subnet(dst, &sel.daddr, &sel.prefixlen_d);
+	ts2subnet(src, &sel.saddr, &sel.prefixlen_s);
+	ts2ports(dst, &sel.dport, &sel.dport_mask);
+	ts2ports(src, &sel.sport, &sel.sport_mask);
+	sel.ifindex = 0;
+	sel.user = 0;
+	
+	return sel;
+}
+
+/**
+ * Creates an rtattr and adds it to the netlink message
+ */
+static void add_attribute(struct nlmsghdr *hdr, int rta_type, chunk_t data,
+						  size_t buflen)
+{
+	struct rtattr *rta;
+	
+	if (NLMSG_ALIGN(hdr->nlmsg_len) + RTA_ALIGN(data.len) > buflen)
+	{
+		DBG1(DBG_KNL, "unable to add attribute, buffer too small");
+		return;
+	}
+	
+	rta = (struct rtattr*)(((char*)hdr) + NLMSG_ALIGN(hdr->nlmsg_len));
+	rta->rta_type = rta_type;
+	rta->rta_len = RTA_LENGTH(data.len);
+	memcpy(RTA_DATA(rta), data.ptr, data.len);
+	hdr->nlmsg_len = NLMSG_ALIGN(hdr->nlmsg_len) + rta->rta_len;
+}
+
+/**
+ * Receives events from kernel
+ */
+static void receive_events(private_kernel_interface_t *this)
+{
+	charon->drop_capabilities(charon, TRUE);
+
+	while(TRUE) 
+	{
+		unsigned char response[512];
+		struct nlmsghdr *hdr;
+		struct sockaddr_nl addr;
+		socklen_t addr_len = sizeof(addr);
+		int len;
+		
+		hdr = (struct nlmsghdr*)response;
+		len = recvfrom(this->socket_xfrm_events, response, sizeof(response),
+					   0, (struct sockaddr*)&addr, &addr_len);
+		if (len < 0)
+		{
+			if (errno == EINTR)
+			{
+				/* interrupted, try again */
+				continue;
+			}
+			charon->kill(charon, "unable to receive netlink events");
+		}
+		
+		if (!NLMSG_OK(hdr, len))
+		{
+			/* bad netlink message */
+			continue;
+		}
+
+		if (addr.nl_pid != 0)
+		{
+			/* not from kernel. not interested, try another one */
+			continue;
+		}
+		
+		/* we handle ACQUIRE and EXPIRE messages directly */
+		if (hdr->nlmsg_type == XFRM_MSG_ACQUIRE)
+		{
+			u_int32_t reqid = 0;
+			job_t *job;
+			struct rtattr *rtattr = XFRM_RTA(hdr, struct xfrm_user_acquire);
+			size_t rtsize = XFRM_PAYLOAD(hdr, struct xfrm_user_tmpl);
+			if (RTA_OK(rtattr, rtsize))
+			{
+				if (rtattr->rta_type == XFRMA_TMPL)
+				{
+					struct xfrm_user_tmpl* tmpl = (struct xfrm_user_tmpl*)RTA_DATA(rtattr);
+					reqid = tmpl->reqid;
+				}
+			}
+			if (reqid == 0)
+			{
+				DBG1(DBG_KNL, "received a XFRM_MSG_ACQUIRE, but no reqid found");
+			}
+			else
+			{
+				DBG2(DBG_KNL, "received a XFRM_MSG_ACQUIRE");
+				DBG1(DBG_KNL, "creating acquire job for CHILD_SA with reqid %d",
+					 reqid);
+				job = (job_t*)acquire_job_create(reqid);
+				charon->job_queue->add(charon->job_queue, job);
+			}
+		}
+		else if (hdr->nlmsg_type == XFRM_MSG_EXPIRE)
+		{
+			job_t *job;
+			protocol_id_t protocol;
+			u_int32_t spi, reqid;
+			struct xfrm_user_expire *expire;
+			
+			expire = (struct xfrm_user_expire*)NLMSG_DATA(hdr);
+			protocol = expire->state.id.proto == KERNEL_ESP ?
+														PROTO_ESP : PROTO_AH;
+			spi = expire->state.id.spi;
+			reqid = expire->state.reqid;
+			
+			DBG2(DBG_KNL, "received a XFRM_MSG_EXPIRE");
+			DBG1(DBG_KNL, "creating %s job for %N CHILD_SA 0x%x (reqid %d)",
+				 expire->hard ? "delete" : "rekey",  protocol_id_names,
+				 protocol, ntohl(spi), reqid);
+			if (expire->hard)
+			{
+				job = (job_t*)delete_child_sa_job_create(reqid, protocol, spi);
+			}
+			else
+			{
+				job = (job_t*)rekey_child_sa_job_create(reqid, protocol, spi);
+			}
+			charon->job_queue->add(charon->job_queue, job);
+		}
+	}
+}
+
+/**
+ * send a netlink message and wait for a reply
+ */
+static status_t netlink_send(int socket, struct nlmsghdr *in,
+							 struct nlmsghdr **out, size_t *out_len)
+{
+	int len, addr_len;
+	struct sockaddr_nl addr;
+	chunk_t result = chunk_empty, tmp;
+	struct nlmsghdr *msg, peek;
+	
+	static int seq = 200;
+	static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+	
+	
+	pthread_mutex_lock(&mutex);
+	
+	in->nlmsg_seq = ++seq;
+	in->nlmsg_pid = getpid();
+	
+	memset(&addr, 0, sizeof(addr));
+	addr.nl_family = AF_NETLINK;
+	addr.nl_pid = 0;
+	addr.nl_groups = 0;
+
+	while (TRUE)
+	{
+		len = sendto(socket, in, in->nlmsg_len, 0, 
+					 (struct sockaddr*)&addr, sizeof(addr));
+		
+		if (len != in->nlmsg_len)
+		{	
+			if (errno == EINTR)
+			{
+				/* interrupted, try again */
+				continue;
+			}
+			pthread_mutex_unlock(&mutex);
+			DBG1(DBG_KNL, "error sending to netlink socket: %s", strerror(errno));
+			return FAILED;
+		}
+		break;
+	}
+	
+	while (TRUE)
+	{	
+		char buf[1024];
+		tmp.len = sizeof(buf);
+		tmp.ptr = buf;
+		msg = (struct nlmsghdr*)tmp.ptr;
+		
+		memset(&addr, 0, sizeof(addr));
+		addr.nl_family = AF_NETLINK;
+		addr.nl_pid = getpid();
+		addr.nl_groups = 0;
+		addr_len = sizeof(addr);
+		
+		len = recvfrom(socket, tmp.ptr, tmp.len, 0,
+					   (struct sockaddr*)&addr, &addr_len);
+		
+		if (len < 0)
+		{
+			if (errno == EINTR)
+			{
+				DBG1(DBG_IKE, "got interrupted");
+				/* interrupted, try again */
+				continue;
+			}
+			DBG1(DBG_IKE, "error reading from netlink socket: %s", strerror(errno));
+			pthread_mutex_unlock(&mutex);
+			return FAILED;
+		}
+		if (!NLMSG_OK(msg, len))
+		{
+			DBG1(DBG_IKE, "received corrupted netlink message");
+			pthread_mutex_unlock(&mutex);
+			return FAILED;
+		}
+		if (msg->nlmsg_seq != seq)
+		{
+			DBG1(DBG_IKE, "received invalid netlink sequence number");
+			if (msg->nlmsg_seq < seq)
+			{
+				continue;
+			}
+			pthread_mutex_unlock(&mutex);
+			return FAILED;
+		}
+		
+		tmp.len = len;
+		result = chunk_cata("cc", result, tmp);
+		
+		/* NLM_F_MULTI flag does not seem to be set correctly, we use sequence
+		 * numbers to detect multi header messages */
+		len = recvfrom(socket, &peek, sizeof(peek), MSG_PEEK | MSG_DONTWAIT,
+					   (struct sockaddr*)&addr, &addr_len);
+		
+		if (len == sizeof(peek) && peek.nlmsg_seq == seq)
+		{
+			/* seems to be multipart */
+			continue;
+		}
+		break;
+	}
+	
+	*out_len = result.len;
+	*out = (struct nlmsghdr*)clalloc(result.ptr, result.len);
+	
+	pthread_mutex_unlock(&mutex);
+	
+	return SUCCESS;
+}
+
+/**
+ * send a netlink message and wait for its acknowlegde
+ */
+static status_t netlink_send_ack(int socket, struct nlmsghdr *in)
+{
+	struct nlmsghdr *out, *hdr;
+	size_t len;
+
+	if (netlink_send(socket, in, &out, &len) != SUCCESS)
+	{
+		return FAILED;
+	}
+	hdr = out;
+	while (NLMSG_OK(hdr, len))
+	{
+		switch (hdr->nlmsg_type)
+		{
+			case NLMSG_ERROR:
+			{
+				struct nlmsgerr* err = (struct nlmsgerr*)NLMSG_DATA(hdr);
+				
+				if (err->error)
+				{
+					DBG1(DBG_KNL, "received netlink error: %s (%d)",
+						 strerror(-err->error), -err->error);
+					free(out);
+					return FAILED;
+				}
+				free(out);
+				return SUCCESS;
+			}
+			default:
+				hdr = NLMSG_NEXT(hdr, len);
+				continue;
+			case NLMSG_DONE:
+				break;
+		}
+		break;
+	}
+	DBG1(DBG_KNL, "netlink request not acknowlegded");
+	free(out);
+	return FAILED;
+}
+	
+/**
+ * Create a list of local addresses.
+ */
+static linked_list_t *create_address_list(private_kernel_interface_t *this)
+{
+	char request[BUFFER_SIZE];
+	struct nlmsghdr *out, *hdr;
+	struct rtgenmsg *msg;
+	size_t len;
+	linked_list_t *list;
+	
+	DBG2(DBG_IKE, "getting local address list");
+	
+	list = linked_list_create();
+	
+	memset(&request, 0, sizeof(request));
+
+	hdr = (struct nlmsghdr*)&request;
+	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg));
+	hdr->nlmsg_type = RTM_GETADDR;
+	hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_MATCH | NLM_F_ROOT;
+	msg = (struct rtgenmsg*)NLMSG_DATA(hdr);
+	msg->rtgen_family = AF_UNSPEC;
+		
+	if (netlink_send(this->socket_rt, hdr, &out, &len) == SUCCESS)
+	{
+		hdr = out;
+		while (NLMSG_OK(hdr, len))
+		{
+			switch (hdr->nlmsg_type)
+			{
+				case RTM_NEWADDR:
+				{
+					struct ifaddrmsg* msg = (struct ifaddrmsg*)(NLMSG_DATA(hdr));
+	      			struct rtattr *rta = IFA_RTA(msg);
+	     			size_t rtasize = IFA_PAYLOAD (hdr);
+					host_t *host = NULL;
+					char *name = NULL;
+					chunk_t local = chunk_empty, address = chunk_empty;
+	     			
+					while(RTA_OK(rta, rtasize))
+					{
+						switch (rta->rta_type)
+						{
+							case IFA_LOCAL:
+								local.ptr = RTA_DATA(rta);
+								local.len = RTA_PAYLOAD(rta);
+								break;
+							case IFA_ADDRESS:
+								address.ptr = RTA_DATA(rta);
+								address.len = RTA_PAYLOAD(rta);
+								break;
+							case IFA_LABEL:
+								name = RTA_DATA(rta);
+								break;
+						}
+						rta = RTA_NEXT(rta, rtasize);
+					}
+					
+					/* For PPP interfaces, we need the IFA_LOCAL address,
+					 * IFA_ADDRESS is the peers address. But IFA_LOCAL is
+					 * not included in all cases, so fallback to IFA_ADDRESS. */
+					if (local.ptr)
+					{
+						host = host_create_from_chunk(msg->ifa_family, local, 0);
+					}
+					else if (address.ptr)
+					{
+						host = host_create_from_chunk(msg->ifa_family, address, 0);
+					}
+					
+					if (host)
+					{
+						address_entry_t *entry;
+						
+						entry = malloc_thing(address_entry_t);
+						entry->host = host;
+						entry->ifindex = msg->ifa_index;
+						if (name)
+						{
+							memcpy(entry->ifname, name, IFNAMSIZ);
+						}
+						else
+						{
+							strcpy(entry->ifname, "(unknown)");
+						}
+						list->insert_last(list, entry);
+					}
+					hdr = NLMSG_NEXT(hdr, len);
+					continue;
+				}
+				default:
+					hdr = NLMSG_NEXT(hdr, len);
+					continue;
+				case NLMSG_DONE:
+					break;
+			}
+			break;
+		}
+		free(out);
+	}
+	else
+	{
+		DBG1(DBG_IKE, "unable to get local address list");
+	}
+
+	return list;
+}
+
+/**
+ * Implements kernel_interface_t.create_address_list.
+ */
+static linked_list_t *create_address_list_public(private_kernel_interface_t *this)
+{
+	linked_list_t *result, *list;
+	address_entry_t *entry;
+	
+	result = linked_list_create();
+	list = create_address_list(this);
+	while (list->remove_last(list, (void**)&entry) == SUCCESS)
+	{
+		result->insert_last(result, entry->host);
+		free(entry);
+	}
+	list->destroy(list);
+	
+	return result;
+}
+
+/**
+ * implementation of kernel_interface_t.get_interface_name
+ */
+static char *get_interface_name(private_kernel_interface_t *this, host_t* ip)
+{
+	linked_list_t *list;
+	address_entry_t *entry;
+	char *name = NULL;
+	
+	DBG2(DBG_IKE, "getting interface name for %H", ip);
+	
+	list = create_address_list(this);
+	while (!name && list->remove_last(list, (void**)&entry) == SUCCESS)
+	{
+		if (ip->ip_equals(ip, entry->host))
+		{
+			name = strdup(entry->ifname);
+		}
+		address_entry_destroy(entry);
+	}
+	list->destroy_function(list, (void*)address_entry_destroy);
+	
+	if (name)
+	{
+		DBG2(DBG_IKE, "%H is on interface %s", ip, name);
+	}
+	else
+	{
+		DBG2(DBG_IKE, "%H is not a local address", ip);
+	}
+	return name;
+}
+
+/**
+ * Tries to find an ip address of a local interface that is included in the
+ * supplied traffic selector.
+ */
+static status_t get_address_by_ts(private_kernel_interface_t *this,
+								  traffic_selector_t *ts, host_t **ip)
+{
+	address_entry_t *entry;
+	host_t *host;
+	int family;
+	linked_list_t *list;
+	bool found = FALSE;
+	
+	DBG2(DBG_IKE, "getting a local address in traffic selector %R", ts);
+	
+	/* if we have a family which includes localhost, we do not
+	 * search for an IP, we use the default */
+	family = ts->get_type(ts) == TS_IPV4_ADDR_RANGE ? AF_INET : AF_INET6;
+	
+	if (family == AF_INET)
+	{
+		host = host_create_from_string("127.0.0.1", 0);
+	}
+	else
+	{
+		host = host_create_from_string("::1", 0);
+	}
+	
+	if (ts->includes(ts, host))
+	{
+		*ip = host_create_any(family);
+		host->destroy(host);
+		DBG2(DBG_IKE, "using host %H", *ip);
+		return SUCCESS;
+	}
+	host->destroy(host);
+	
+	list = create_address_list(this);
+	while (!found && list->remove_last(list, (void**)&entry) == SUCCESS)
+	{
+		if (ts->includes(ts, entry->host))
+		{
+			found = TRUE;
+			*ip = entry->host->clone(entry->host);
+		}
+		address_entry_destroy(entry);
+	}
+	list->destroy_function(list, (void*)address_entry_destroy);
+	
+	if (!found)
+	{
+		DBG1(DBG_IKE, "no local address found in traffic selector %R", ts);
+		return FAILED;
+	}
+	DBG2(DBG_IKE, "using host %H", *ip);
+	return SUCCESS;
+}
+
+/**
+ * get the interface of a local address
+ */
+static int get_interface_index(private_kernel_interface_t *this, host_t* ip)
+{
+	linked_list_t *list;
+	address_entry_t *entry;
+	int ifindex = 0;
+	
+	DBG2(DBG_IKE, "getting iface for %H", ip);
+	
+	list = create_address_list(this);
+	while (!ifindex && list->remove_last(list, (void**)&entry) == SUCCESS)
+	{
+		if (ip->ip_equals(ip, entry->host))
+		{
+			ifindex = entry->ifindex;
+		}
+		address_entry_destroy(entry);
+	}
+	list->destroy_function(list, (void*)address_entry_destroy);
+	
+	if (ifindex == 0)
+	{
+		DBG1(DBG_IKE, "unable to get interface for %H", ip);
+	}
+	return ifindex;
+}
+
+/**
+ * Manages the creation and deletion of ip addresses on an interface.
+ * By setting the appropriate nlmsg_type, the ip will be set or unset.
+ */
+static status_t manage_ipaddr(private_kernel_interface_t *this, int nlmsg_type,
+							  int flags, int if_index, host_t *ip)
+{
+	unsigned char request[BUFFER_SIZE];
+	struct nlmsghdr *hdr;
+	struct ifaddrmsg *msg;
+	chunk_t chunk;
+	
+	memset(&request, 0, sizeof(request));
+	
+	chunk = ip->get_address(ip);
+    
+    hdr = (struct nlmsghdr*)request;
+	hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags;
+	hdr->nlmsg_type = nlmsg_type; 
+	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
+	
+	msg = (struct ifaddrmsg*)NLMSG_DATA(hdr);
+    msg->ifa_family = ip->get_family(ip);
+    msg->ifa_flags = 0;
+    msg->ifa_prefixlen = 8 * chunk.len;
+    msg->ifa_scope = RT_SCOPE_UNIVERSE;
+    msg->ifa_index = if_index;
+	
+	add_attribute(hdr, IFA_LOCAL, chunk, sizeof(request));
+
+	return netlink_send_ack(this->socket_rt, hdr);
+}
+
+/**
+ * Manages source routes in the routing table.
+ * By setting the appropriate nlmsg_type, the route added or r.
+ */
+static status_t manage_srcroute(private_kernel_interface_t *this, int nlmsg_type,
+								int flags, route_entry_t *route)
+{
+	unsigned char request[BUFFER_SIZE];
+	struct nlmsghdr *hdr;
+	struct rtmsg *msg;
+	chunk_t chunk;
+	
+	/* if route is 0.0.0.0/0, we can't install it, as it would
+	 * overwrite the default route. Instead, we add two routes:
+	 * 0.0.0.0/1 and 128.0.0.0/1 
+	 * TODO: use metrics instead */
+	if (route->prefixlen == 0)
+	{
+		route_entry_t half;
+		status_t status;
+		
+		half.dst_net = chunk_alloca(route->dst_net.len);
+		memset(half.dst_net.ptr, 0, half.dst_net.len);
+		half.src_ip = route->src_ip;
+		half.gateway = route->gateway;
+		half.if_index = route->if_index;
+		half.prefixlen = 1;
+		
+		status = manage_srcroute(this, nlmsg_type, flags, &half);
+		half.dst_net.ptr[0] |= 0x80;
+		status = manage_srcroute(this, nlmsg_type, flags, &half);
+		return status;
+	}
+	
+	memset(&request, 0, sizeof(request));
+
+	hdr = (struct nlmsghdr*)request;
+	hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags;
+	hdr->nlmsg_type = nlmsg_type;
+	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
+
+	msg = (struct rtmsg*)NLMSG_DATA(hdr);
+	msg->rtm_family = route->src_ip->get_family(route->src_ip);
+	msg->rtm_dst_len = route->prefixlen;
+	msg->rtm_table = RT_TABLE_MAIN;
+	msg->rtm_protocol = RTPROT_STATIC;
+	msg->rtm_type = RTN_UNICAST;
+	msg->rtm_scope = RT_SCOPE_UNIVERSE;
+	
+	add_attribute(hdr, RTA_DST, route->dst_net, sizeof(request));
+	chunk = route->src_ip->get_address(route->src_ip);
+	add_attribute(hdr, RTA_PREFSRC, chunk, sizeof(request));
+	chunk = route->gateway->get_address(route->gateway);
+	add_attribute(hdr, RTA_GATEWAY, chunk, sizeof(request));
+	chunk.ptr = (char*)&route->if_index;
+	chunk.len = sizeof(route->if_index);
+	add_attribute(hdr, RTA_OIF, chunk, sizeof(request));
+
+	return netlink_send_ack(this->socket_rt, hdr);
+}
+
+
+/**
+ * Implementation of kernel_interface_t.add_ip.
+ */
+static status_t add_ip(private_kernel_interface_t *this, 
+						host_t *virtual_ip, host_t *iface_ip)
+{
+	int targetif;
+	vip_entry_t *listed;
+	iterator_t *iterator;
+
+	DBG2(DBG_KNL, "adding virtual IP %H", virtual_ip);
+
+	targetif = get_interface_index(this, iface_ip);
+	if (targetif == 0)
+	{
+		DBG1(DBG_KNL, "unable to add virtual IP %H, no iface found for %H",
+			 virtual_ip, iface_ip);
+		return FAILED;
+	}
+
+	/* beware of deadlocks (e.g. send/receive packets while holding the lock) */
+	iterator = this->vips->create_iterator_locked(this->vips, &(this->vips_mutex));
+	while (iterator->iterate(iterator, (void**)&listed))
+	{
+		if (listed->if_index == targetif &&
+			virtual_ip->ip_equals(virtual_ip, listed->ip))
+		{
+			listed->refcount++;
+			iterator->destroy(iterator);
+			DBG2(DBG_KNL, "virtual IP %H already added to iface %d reusing it",
+				 virtual_ip, targetif);
+			return SUCCESS;
+		}
+	}
+	iterator->destroy(iterator);
+
+	if (manage_ipaddr(this, RTM_NEWADDR, NLM_F_CREATE | NLM_F_EXCL,
+					  targetif, virtual_ip) == SUCCESS)
+	{
+		listed = malloc_thing(vip_entry_t);
+		listed->ip = virtual_ip->clone(virtual_ip);
+		listed->if_index = targetif;
+		listed->refcount = 1;
+		this->vips->insert_last(this->vips, listed);
+		DBG2(DBG_KNL, "virtual IP %H added to iface %d",
+				 virtual_ip, targetif);
+		return SUCCESS;
+	}
+	
+	DBG2(DBG_KNL, "unable to add virtual IP %H to iface %d",
+		 virtual_ip, targetif);
+	return FAILED;
+}
+
+/**
+ * Implementation of kernel_interface_t.del_ip.
+ */
+static status_t del_ip(private_kernel_interface_t *this,
+						host_t *virtual_ip, host_t *iface_ip)
+{
+	int targetif;
+	vip_entry_t *listed;
+	iterator_t *iterator;
+
+	DBG2(DBG_KNL, "deleting virtual IP %H", virtual_ip);
+
+	targetif = get_interface_index(this, iface_ip);
+	if (targetif == 0)
+	{
+		DBG1(DBG_KNL, "unable to delete virtual IP %H, no iface found for %H",
+			 virtual_ip, iface_ip);
+		return FAILED;
+	}
+
+	/* beware of deadlocks (e.g. send/receive packets while holding the lock) */
+	iterator = this->vips->create_iterator_locked(this->vips, &(this->vips_mutex));
+	while (iterator->iterate(iterator, (void**)&listed))
+	{
+		if (listed->if_index == targetif &&
+			virtual_ip->ip_equals(virtual_ip, listed->ip))
+		{
+			listed->refcount--;
+			if (listed->refcount == 0)
+			{
+				iterator->remove(iterator);
+				vip_entry_destroy(listed);
+				iterator->destroy(iterator);
+				return manage_ipaddr(this, RTM_DELADDR, 0, targetif, virtual_ip);
+			}
+			iterator->destroy(iterator);
+			DBG2(DBG_KNL, "virtual IP %H used by other SAs, not deleting",
+		 		 virtual_ip);
+			return SUCCESS;
+		}
+	}
+	iterator->destroy(iterator);
+ 
+	DBG2(DBG_KNL, "virtual IP %H not cached, unable to delete", virtual_ip);
+	return FAILED;
+}
+
+/**
+ * Implementation of kernel_interface_t.get_spi.
+ */
+static status_t get_spi(private_kernel_interface_t *this, 
+						host_t *src, host_t *dst, 
+						protocol_id_t protocol, u_int32_t reqid,
+						u_int32_t *spi)
+{
+	unsigned char request[BUFFER_SIZE];
+	struct nlmsghdr *hdr, *out;
+	struct xfrm_userspi_info *userspi;
+	u_int32_t received_spi = 0;
+	size_t len;
+	
+	memset(&request, 0, sizeof(request));
+	
+	DBG2(DBG_KNL, "getting SPI for reqid %d", reqid);
+	
+	hdr = (struct nlmsghdr*)request;
+	hdr->nlmsg_flags = NLM_F_REQUEST;
+	hdr->nlmsg_type = XFRM_MSG_ALLOCSPI;
+	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_userspi_info));
+
+	userspi = (struct xfrm_userspi_info*)NLMSG_DATA(hdr);
+	host2xfrm(src, &userspi->info.saddr);
+	host2xfrm(dst, &userspi->info.id.daddr);
+	userspi->info.id.proto = (protocol == PROTO_ESP) ? KERNEL_ESP : KERNEL_AH;
+	userspi->info.mode = TRUE; /* tunnel mode */
+	userspi->info.reqid = reqid;
+	userspi->info.family = src->get_family(src);
+	userspi->min = 0xc0000000;
+	userspi->max = 0xcFFFFFFF;
+	
+	if (netlink_send(this->socket_xfrm, hdr, &out, &len) == SUCCESS)
+	{
+		hdr = out;
+		while (NLMSG_OK(hdr, len))
+		{
+			switch (hdr->nlmsg_type)
+			{
+				case XFRM_MSG_NEWSA:
+				{
+					struct xfrm_usersa_info* usersa = NLMSG_DATA(hdr);
+					received_spi = usersa->id.spi;
+					break;
+				}
+				case NLMSG_ERROR:
+				{
+					struct nlmsgerr *err = NLMSG_DATA(hdr);
+					
+					DBG1(DBG_KNL, "allocating SPI failed: %s (%d)",
+						 strerror(-err->error), -err->error);
+					break;
+				}
+				default:
+					hdr = NLMSG_NEXT(hdr, len);
+					continue;
+				case NLMSG_DONE:
+					break;
+			}
+			break;
+		}
+		free(out);
+	}
+	
+	if (received_spi == 0)
+	{
+		DBG1(DBG_KNL, "unable to get SPI for reqid %d", reqid);
+		return FAILED;
+	}
+	
+	DBG2(DBG_KNL, "got SPI 0x%x for reqid %d", received_spi, reqid);
+	
+	*spi = received_spi;
+	return SUCCESS;
+}
+
+/**
+ * Implementation of kernel_interface_t.add_sa.
+ */
+static status_t add_sa(private_kernel_interface_t *this,
+					   host_t *src, host_t *dst, u_int32_t spi,
+					   protocol_id_t protocol, u_int32_t reqid,
+					   u_int64_t expire_soft, u_int64_t expire_hard,
+					   algorithm_t *enc_alg, algorithm_t *int_alg,
+					   prf_plus_t *prf_plus, natt_conf_t *natt, mode_t mode,
+					   bool replace)
+{
+	unsigned char request[BUFFER_SIZE];
+	char *alg_name;
+	u_int key_size;
+	struct nlmsghdr *hdr;
+	struct xfrm_usersa_info *sa;
+	
+	memset(&request, 0, sizeof(request));
+	
+	DBG2(DBG_KNL, "adding SAD entry with SPI 0x%x", spi);
+
+	hdr = (struct nlmsghdr*)request;
+	hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
+	hdr->nlmsg_type = replace ? XFRM_MSG_UPDSA : XFRM_MSG_NEWSA;
+	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_usersa_info));
+	
+	sa = (struct xfrm_usersa_info*)NLMSG_DATA(hdr);
+	host2xfrm(src, &sa->saddr);
+	host2xfrm(dst, &sa->id.daddr);
+	sa->id.spi = spi;
+	sa->id.proto = (protocol == PROTO_ESP) ? KERNEL_ESP : KERNEL_AH;
+	sa->family = src->get_family(src);
+	sa->mode = mode;
+	sa->replay_window = 32;
+	sa->reqid = reqid;
+	/* we currently do not expire SAs by volume/packet count */
+	sa->lft.soft_byte_limit = XFRM_INF;
+	sa->lft.hard_byte_limit = XFRM_INF;
+	sa->lft.soft_packet_limit = XFRM_INF;
+	sa->lft.hard_packet_limit = XFRM_INF;
+	/* we use lifetimes since added, not since used */
+	sa->lft.soft_add_expires_seconds = expire_soft;
+	sa->lft.hard_add_expires_seconds = expire_hard;
+	sa->lft.soft_use_expires_seconds = 0;
+	sa->lft.hard_use_expires_seconds = 0;
+	
+	struct rtattr *rthdr = XFRM_RTA(hdr, struct xfrm_usersa_info);
+	
+	if (enc_alg->algorithm != ENCR_UNDEFINED)
+	{
+		rthdr->rta_type = XFRMA_ALG_CRYPT;
+		alg_name = lookup_algorithm(encryption_algs, enc_alg, &key_size);
+		if (alg_name == NULL)
+		{
+			DBG1(DBG_KNL, "algorithm %N not supported by kernel!",
+				 encryption_algorithm_names, enc_alg->algorithm);
+			return FAILED;
+		}
+		DBG2(DBG_KNL, "  using encryption algorithm %N with key size %d",
+			 encryption_algorithm_names, enc_alg->algorithm, key_size);
+		
+		rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_algo) + key_size);
+		hdr->nlmsg_len += rthdr->rta_len;
+		if (hdr->nlmsg_len > sizeof(request))
+		{
+			return FAILED;
+		}
+		
+		struct xfrm_algo* algo = (struct xfrm_algo*)RTA_DATA(rthdr);
+		algo->alg_key_len = key_size;
+		strcpy(algo->alg_name, alg_name);
+		prf_plus->get_bytes(prf_plus, key_size / 8, algo->alg_key);
+		
+		rthdr = XFRM_RTA_NEXT(rthdr);
+	}
+	
+	if (int_alg->algorithm  != AUTH_UNDEFINED)
+	{
+		rthdr->rta_type = XFRMA_ALG_AUTH;
+		alg_name = lookup_algorithm(integrity_algs, int_alg, &key_size);
+		if (alg_name == NULL)
+		{
+			DBG1(DBG_KNL, "algorithm %N not supported by kernel!", 
+				 integrity_algorithm_names, int_alg->algorithm);
+			return FAILED;
+		}
+		DBG2(DBG_KNL, "  using integrity algorithm %N with key size %d",
+			 integrity_algorithm_names, int_alg->algorithm, key_size);
+		
+		rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_algo) + key_size);
+		hdr->nlmsg_len += rthdr->rta_len;
+		if (hdr->nlmsg_len > sizeof(request))
+		{
+			return FAILED;
+		}
+		
+		struct xfrm_algo* algo = (struct xfrm_algo*)RTA_DATA(rthdr);
+		algo->alg_key_len = key_size;
+		strcpy(algo->alg_name, alg_name);
+		prf_plus->get_bytes(prf_plus, key_size / 8, algo->alg_key);
+		
+		rthdr = XFRM_RTA_NEXT(rthdr);
+	}
+	
+	/* TODO: add IPComp here */
+	
+	if (natt)
+	{
+		rthdr->rta_type = XFRMA_ENCAP;
+		rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_encap_tmpl));
+
+		hdr->nlmsg_len += rthdr->rta_len;
+		if (hdr->nlmsg_len > sizeof(request))
+		{
+			return FAILED;
+		}
+
+		struct xfrm_encap_tmpl* encap = (struct xfrm_encap_tmpl*)RTA_DATA(rthdr);
+		encap->encap_type = UDP_ENCAP_ESPINUDP;
+		encap->encap_sport = htons(natt->sport);
+		encap->encap_dport = htons(natt->dport);
+		memset(&encap->encap_oa, 0, sizeof (xfrm_address_t));
+		/* encap_oa could probably be derived from the 
+		 * traffic selectors [rfc4306, p39]. In the netlink kernel implementation 
+		 * pluto does the same as we do here but it uses encap_oa in the 
+		 * pfkey implementation. BUT as /usr/src/linux/net/key/af_key.c indicates 
+		 * the kernel ignores it anyway
+		 *   -> does that mean that NAT-T encap doesn't work in transport mode?
+		 * No. The reason the kernel ignores NAT-OA is that it recomputes 
+		 * (or, rather, just ignores) the checksum. If packets pass
+		 * the IPsec checks it marks them "checksum ok" so OA isn't needed. */
+		rthdr = XFRM_RTA_NEXT(rthdr);
+	}
+	
+	if (netlink_send_ack(this->socket_xfrm, hdr) != SUCCESS)
+	{
+		DBG1(DBG_KNL, "unalbe to add SAD entry with SPI 0x%x", spi);
+		return FAILED;
+	}
+	return SUCCESS;
+}
+
+/**
+ * Implementation of kernel_interface_t.update_sa.
+ */
+static status_t update_sa(private_kernel_interface_t *this,
+						  host_t *src, host_t *dst, 
+						  host_t *new_src, host_t *new_dst, 
+						  host_diff_t src_changes, host_diff_t dst_changes,
+						  u_int32_t spi, protocol_id_t protocol)
+{
+	unsigned char request[BUFFER_SIZE];
+	struct nlmsghdr *hdr, *out = NULL;
+	struct xfrm_usersa_id *sa_id;
+	struct xfrm_usersa_info *sa = NULL;
+	size_t len;
+	
+	memset(&request, 0, sizeof(request));
+	
+	DBG2(DBG_KNL, "querying SAD entry with SPI 0x%x", spi);
+
+	hdr = (struct nlmsghdr*)request;
+	hdr->nlmsg_flags = NLM_F_REQUEST;
+	hdr->nlmsg_type = XFRM_MSG_GETSA;
+	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_usersa_id));
+
+	sa_id = (struct xfrm_usersa_id*)NLMSG_DATA(hdr);
+	host2xfrm(dst, &sa_id->daddr);
+	sa_id->spi = spi;
+	sa_id->proto = (protocol == PROTO_ESP) ? KERNEL_ESP : KERNEL_AH;
+	sa_id->family = dst->get_family(dst);
+	
+	if (netlink_send(this->socket_xfrm, hdr, &out, &len) == SUCCESS)
+	{
+		hdr = out;
+		while (NLMSG_OK(hdr, len))
+		{
+			switch (hdr->nlmsg_type)
+			{
+				case XFRM_MSG_NEWSA:
+				{
+					sa = NLMSG_DATA(hdr);
+					break;
+				}
+				case NLMSG_ERROR:
+				{
+					struct nlmsgerr *err = NLMSG_DATA(hdr);
+					DBG1(DBG_KNL, "querying SAD entry failed: %s (%d)",
+						 strerror(-err->error), -err->error);
+					break;
+				}
+				default:
+					hdr = NLMSG_NEXT(hdr, len);
+					continue;
+				case NLMSG_DONE:
+					break;
+			}
+			break;
+		}
+	}
+	if (sa == NULL)
+	{
+		DBG1(DBG_KNL, "unable to update SAD entry with SPI 0x%x", spi);
+		free(out);
+		return FAILED;
+	}
+	
+	DBG2(DBG_KNL, "updating SAD entry with SPI 0x%x", spi);
+	
+	hdr = out;
+	hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;	
+	hdr->nlmsg_type = XFRM_MSG_UPDSA;
+	
+	if (src_changes & HOST_DIFF_ADDR)
+	{
+		host2xfrm(new_src, &sa->saddr);
+	}
+
+	if (dst_changes & HOST_DIFF_ADDR)
+	{
+		hdr->nlmsg_type = XFRM_MSG_NEWSA;
+		host2xfrm(new_dst, &sa->id.daddr);
+	}
+	
+	if (src_changes & HOST_DIFF_PORT || dst_changes & HOST_DIFF_PORT)
+	{
+		struct rtattr *rtattr = XFRM_RTA(hdr, struct xfrm_usersa_info);
+		size_t rtsize = XFRM_PAYLOAD(hdr, struct xfrm_usersa_info);
+		while (RTA_OK(rtattr, rtsize))
+		{
+			if (rtattr->rta_type == XFRMA_ENCAP)
+			{
+				struct xfrm_encap_tmpl* encap;
+				encap = (struct xfrm_encap_tmpl*)RTA_DATA(rtattr);
+				encap->encap_sport = ntohs(new_src->get_port(new_src));
+				encap->encap_dport = ntohs(new_dst->get_port(new_dst));
+				break;
+			}
+			rtattr = RTA_NEXT(rtattr, rtsize);
+		}
+	}
+	if (netlink_send_ack(this->socket_xfrm, hdr) != SUCCESS)
+	{
+		DBG1(DBG_KNL, "unalbe to update SAD entry with SPI 0x%x", spi);
+		free(out);
+		return FAILED;
+	}
+	free(out);
+	
+	if (dst_changes & HOST_DIFF_ADDR)
+	{
+		return this->public.del_sa(&this->public, dst, spi, protocol);
+	}
+	return SUCCESS;
+}
+
+/**
+ * Implementation of kernel_interface_t.query_sa.
+ */
+static status_t query_sa(private_kernel_interface_t *this, host_t *dst,
+						 u_int32_t spi, protocol_id_t protocol,
+						 u_int32_t *use_time)
+{
+	unsigned char request[BUFFER_SIZE];
+	struct nlmsghdr *out = NULL, *hdr;
+	struct xfrm_usersa_id *sa_id;
+	struct xfrm_usersa_info *sa = NULL;
+	size_t len;
+	
+	DBG2(DBG_KNL, "querying SAD entry with SPI 0x%x", spi);
+	memset(&request, 0, sizeof(request));
+	
+	hdr = (struct nlmsghdr*)request;
+	hdr->nlmsg_flags = NLM_F_REQUEST;
+	hdr->nlmsg_type = XFRM_MSG_GETSA;
+	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_usersa_info));
+
+	sa_id = (struct xfrm_usersa_id*)NLMSG_DATA(hdr);
+	host2xfrm(dst, &sa_id->daddr);
+	sa_id->spi = spi;
+	sa_id->proto = (protocol == PROTO_ESP) ? KERNEL_ESP : KERNEL_AH;
+	sa_id->family = dst->get_family(dst);
+	
+	if (netlink_send(this->socket_xfrm, hdr, &out, &len) == SUCCESS)
+	{
+		hdr = out;
+		while (NLMSG_OK(hdr, len))
+		{
+			switch (hdr->nlmsg_type)
+			{
+				case XFRM_MSG_NEWSA:
+				{
+					sa = NLMSG_DATA(hdr);
+					break;
+				}
+				case NLMSG_ERROR:
+				{
+					struct nlmsgerr *err = NLMSG_DATA(hdr);
+					DBG1(DBG_KNL, "querying SAD entry failed: %s (%d)",
+						 strerror(-err->error), -err->error);
+					break;
+				}
+				default:
+					hdr = NLMSG_NEXT(hdr, len);
+					continue;
+				case NLMSG_DONE:
+					break;
+			}
+			break;
+		}
+	}
+	
+	if (sa == NULL)
+	{
+		DBG1(DBG_KNL, "unable to query SAD entry with SPI 0x%x", spi);
+		free(out);
+		return FAILED;
+	}
+	
+	*use_time = sa->curlft.use_time;
+	free (out);
+	return SUCCESS;
+}
+
+/**
+ * Implementation of kernel_interface_t.del_sa.
+ */
+static status_t del_sa(private_kernel_interface_t *this, host_t *dst,
+					   u_int32_t spi, protocol_id_t protocol)
+{
+	unsigned char request[BUFFER_SIZE];
+	struct nlmsghdr *hdr;
+	struct xfrm_usersa_id *sa_id;
+	
+	memset(&request, 0, sizeof(request));
+	
+	DBG2(DBG_KNL, "deleting SAD entry with SPI 0x%x", spi);
+	
+	hdr = (struct nlmsghdr*)request;
+	hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
+	hdr->nlmsg_type = XFRM_MSG_DELSA;
+	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_usersa_id));
+	
+	sa_id = (struct xfrm_usersa_id*)NLMSG_DATA(hdr);
+	host2xfrm(dst, &sa_id->daddr);
+	sa_id->spi = spi;
+	sa_id->proto = (protocol == PROTO_ESP) ? KERNEL_ESP : KERNEL_AH;
+	sa_id->family = dst->get_family(dst);
+	
+	if (netlink_send_ack(this->socket_xfrm, hdr) != SUCCESS)
+	{
+		DBG1(DBG_KNL, "unalbe to delete SAD entry with SPI 0x%x", spi);
+		return FAILED;
+	}
+	DBG2(DBG_KNL, "deleted SAD entry with SPI 0x%x", spi);
+	return SUCCESS;
+}
+
+/**
+ * Implementation of kernel_interface_t.add_policy.
+ */
+static status_t add_policy(private_kernel_interface_t *this, 
+						   host_t *src, host_t *dst,
+						   traffic_selector_t *src_ts,
+						   traffic_selector_t *dst_ts,
+						   policy_dir_t direction, protocol_id_t protocol,
+						   u_int32_t reqid, bool high_prio, mode_t mode,
+						   bool update)
+{
+	iterator_t *iterator;
+	policy_entry_t *current, *policy;
+	bool found = FALSE;
+	unsigned char request[BUFFER_SIZE];
+	struct xfrm_userpolicy_info *policy_info;
+	struct nlmsghdr *hdr;
+	
+	/* create a policy */
+	policy = malloc_thing(policy_entry_t);
+	memset(policy, 0, sizeof(policy_entry_t));
+	policy->sel = ts2selector(src_ts, dst_ts);
+	policy->direction = direction;
+	
+	/* find the policy, which matches EXACTLY */
+	pthread_mutex_lock(&this->policies_mutex);
+	iterator = this->policies->create_iterator(this->policies, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (memcmp(&current->sel, &policy->sel, sizeof(struct xfrm_selector)) == 0 &&
+			policy->direction == current->direction)
+		{
+			/* use existing policy */
+			if (!update)
+			{
+				current->refcount++;
+				DBG2(DBG_KNL, "policy %R===%R already exists, increasing ",
+					 "refcount", src_ts, dst_ts);
+			}
+			free(policy);
+			policy = current;
+			found = TRUE;
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+	if (!found)
+	{	/* apply the new one, if we have no such policy */
+		this->policies->insert_last(this->policies, policy);
+		policy->refcount = 1;
+	}
+	
+	DBG2(DBG_KNL, "adding policy %R===%R", src_ts, dst_ts);
+	
+	memset(&request, 0, sizeof(request));
+	hdr = (struct nlmsghdr*)request;
+	hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
+	hdr->nlmsg_type = XFRM_MSG_UPDPOLICY;
+	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_userpolicy_info));
+
+	policy_info = (struct xfrm_userpolicy_info*)NLMSG_DATA(hdr);
+	policy_info->sel = policy->sel;
+	policy_info->dir = policy->direction;
+	/* calculate priority based on source selector size, small size = high prio */
+	policy_info->priority = high_prio ? PRIO_HIGH : PRIO_LOW;
+	policy_info->priority -= policy->sel.prefixlen_s * 10;
+	policy_info->priority -= policy->sel.proto ? 2 : 0;
+	policy_info->priority -= policy->sel.sport_mask ? 1 : 0;
+	policy_info->action = XFRM_POLICY_ALLOW;
+	policy_info->share = XFRM_SHARE_ANY;
+	pthread_mutex_unlock(&this->policies_mutex);
+	
+	/* policies don't expire */
+	policy_info->lft.soft_byte_limit = XFRM_INF;
+	policy_info->lft.soft_packet_limit = XFRM_INF;
+	policy_info->lft.hard_byte_limit = XFRM_INF;
+	policy_info->lft.hard_packet_limit = XFRM_INF;
+	policy_info->lft.soft_add_expires_seconds = 0;
+	policy_info->lft.hard_add_expires_seconds = 0;
+	policy_info->lft.soft_use_expires_seconds = 0;
+	policy_info->lft.hard_use_expires_seconds = 0;
+	
+	struct rtattr *rthdr = XFRM_RTA(hdr, struct xfrm_userpolicy_info);
+	rthdr->rta_type = XFRMA_TMPL;
+
+	rthdr->rta_len = sizeof(struct xfrm_user_tmpl);
+	rthdr->rta_len = RTA_LENGTH(rthdr->rta_len);
+
+	hdr->nlmsg_len += rthdr->rta_len;
+	if (hdr->nlmsg_len > sizeof(request))
+	{
+		return FAILED;
+	}
+	
+	struct xfrm_user_tmpl *tmpl = (struct xfrm_user_tmpl*)RTA_DATA(rthdr);
+	tmpl->reqid = reqid;
+	tmpl->id.proto = (protocol == PROTO_AH) ? KERNEL_AH : KERNEL_ESP;
+	tmpl->aalgos = tmpl->ealgos = tmpl->calgos = ~0;
+	tmpl->mode = mode;
+	tmpl->family = src->get_family(src);
+	
+	host2xfrm(src, &tmpl->saddr);
+	host2xfrm(dst, &tmpl->id.daddr);
+	
+	if (netlink_send_ack(this->socket_xfrm, hdr) != SUCCESS)
+	{
+		DBG1(DBG_KNL, "unable to add policy %R===%R", src_ts, dst_ts);
+		return FAILED;
+	}
+	
+	/* install a route, if:
+	 * - we are NOT updating a policy
+	 * - this is a forward policy (to just get one for each child)
+	 * - we are in tunnel mode
+	 * - we are not using IPv6 (does not work correctly yet!)
+	 */
+	if (policy->route == NULL && direction == POLICY_FWD &&
+		mode != MODE_TRANSPORT && src->get_family(src) != AF_INET6)
+	{
+		policy->route = malloc_thing(route_entry_t);
+		if (get_address_by_ts(this, dst_ts, &policy->route->src_ip) == SUCCESS)
+		{
+			policy->route->gateway = dst->clone(dst);
+			policy->route->if_index = get_interface_index(this, dst);
+			policy->route->dst_net = chunk_alloc(policy->sel.family == AF_INET ? 4 : 16);
+			memcpy(policy->route->dst_net.ptr, &policy->sel.saddr, policy->route->dst_net.len);
+			policy->route->prefixlen = policy->sel.prefixlen_s;
+			
+			if (manage_srcroute(this, RTM_NEWROUTE, NLM_F_CREATE | NLM_F_EXCL,
+								policy->route) != SUCCESS)
+			{
+				DBG1(DBG_KNL, "unable to install source route for %H",
+					 policy->route->src_ip);
+				route_entry_destroy(policy->route);
+				policy->route = NULL;
+			}
+		}
+		else
+		{
+			free(policy->route);
+			policy->route = NULL;
+		}
+	}
+
+	return SUCCESS;
+}
+
+/**
+ * Implementation of kernel_interface_t.query_policy.
+ */
+static status_t query_policy(private_kernel_interface_t *this,
+							 traffic_selector_t *src_ts, 
+							 traffic_selector_t *dst_ts,
+							 policy_dir_t direction, u_int32_t *use_time)
+{
+	unsigned char request[BUFFER_SIZE];
+	struct nlmsghdr *out = NULL, *hdr;
+	struct xfrm_userpolicy_id *policy_id;
+	struct xfrm_userpolicy_info *policy = NULL;
+	size_t len;
+	
+	memset(&request, 0, sizeof(request));
+	
+	DBG2(DBG_KNL, "querying policy %R===%R", src_ts, dst_ts);
+
+	hdr = (struct nlmsghdr*)request;
+	hdr->nlmsg_flags = NLM_F_REQUEST;
+	hdr->nlmsg_type = XFRM_MSG_GETPOLICY;
+	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_userpolicy_id));
+
+	policy_id = (struct xfrm_userpolicy_id*)NLMSG_DATA(hdr);
+	policy_id->sel = ts2selector(src_ts, dst_ts);
+	policy_id->dir = direction;
+	
+	if (netlink_send(this->socket_xfrm, hdr, &out, &len) == SUCCESS)
+	{
+		hdr = out;
+		while (NLMSG_OK(hdr, len))
+		{
+			switch (hdr->nlmsg_type)
+			{
+				case XFRM_MSG_NEWPOLICY:
+				{
+					policy = (struct xfrm_userpolicy_info*)NLMSG_DATA(hdr);
+					break;
+				}
+				case NLMSG_ERROR:
+				{
+					struct nlmsgerr *err = NLMSG_DATA(hdr);
+					DBG1(DBG_KNL, "querying policy failed: %s (%d)",
+						 strerror(-err->error), -err->error);
+					break;
+				}
+				default:
+					hdr = NLMSG_NEXT(hdr, len);
+					continue;
+				case NLMSG_DONE:
+					break;
+			}
+			break;
+		}
+	}
+	
+	if (policy == NULL)
+	{
+		DBG2(DBG_KNL, "unable to query policy %R===%R", src_ts, dst_ts);
+		free(out);
+		return FAILED;
+	}
+	*use_time = (time_t)policy->curlft.use_time;
+	
+	free(out);
+	return SUCCESS;
+}
+
+/**
+ * Implementation of kernel_interface_t.del_policy.
+ */
+static status_t del_policy(private_kernel_interface_t *this,
+						   traffic_selector_t *src_ts, 
+						   traffic_selector_t *dst_ts,
+						   policy_dir_t direction)
+{
+	policy_entry_t *current, policy, *to_delete = NULL;
+	route_entry_t *route;
+	unsigned char request[BUFFER_SIZE];
+	struct nlmsghdr *hdr;
+	struct xfrm_userpolicy_id *policy_id;
+	iterator_t *iterator;
+	
+	DBG2(DBG_KNL, "deleting policy %R===%R", src_ts, dst_ts);
+	
+	/* create a policy */
+	memset(&policy, 0, sizeof(policy_entry_t));
+	policy.sel = ts2selector(src_ts, dst_ts);
+	policy.direction = direction;
+	
+	/* find the policy */
+	pthread_mutex_lock(&this->policies_mutex);
+	iterator = this->policies->create_iterator(this->policies, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (memcmp(&current->sel, &policy.sel, sizeof(struct xfrm_selector)) == 0 &&
+			policy.direction == current->direction)
+		{
+			to_delete = current;
+			if (--to_delete->refcount > 0)
+			{
+				/* is used by more SAs, keep in kernel */
+				DBG2(DBG_KNL, "policy still used by another CHILD_SA, not removed");
+				iterator->destroy(iterator);
+				pthread_mutex_unlock(&this->policies_mutex);
+				return SUCCESS;
+			}
+			/* remove if last reference */
+			iterator->remove(iterator);
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+	pthread_mutex_unlock(&this->policies_mutex);
+	if (!to_delete)
+	{
+		DBG1(DBG_KNL, "deleting policy %R===%R failed, not found", src_ts, dst_ts);
+		return NOT_FOUND;
+	}
+	
+	memset(&request, 0, sizeof(request));
+	
+	hdr = (struct nlmsghdr*)request;
+	hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
+	hdr->nlmsg_type = XFRM_MSG_DELPOLICY;
+	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_userpolicy_id));
+
+	policy_id = (struct xfrm_userpolicy_id*)NLMSG_DATA(hdr);
+	policy_id->sel = to_delete->sel;
+	policy_id->dir = direction;
+	
+	route = to_delete->route;
+	free(to_delete);
+	
+	if (netlink_send_ack(this->socket_xfrm, hdr) != SUCCESS)
+	{
+		DBG1(DBG_KNL, "unable to delete policy %R===%R", src_ts, dst_ts);
+		return FAILED;
+	}
+
+	if (route)
+	{
+		if (manage_srcroute(this, RTM_DELROUTE, 0, route) != SUCCESS)
+		{
+			DBG1(DBG_KNL, "error uninstalling route installed with "
+				 "policy %R===%R", src_ts, dst_ts);
+		}		
+		route_entry_destroy(route);
+	}
+	return SUCCESS;
+}
+
+/**
+ * Implementation of kernel_interface_t.destroy.
+ */
+static void destroy(private_kernel_interface_t *this)
+{
+	pthread_cancel(this->event_thread);
+	pthread_join(this->event_thread, NULL);
+	close(this->socket_xfrm_events);
+	close(this->socket_xfrm);
+	close(this->socket_rt);
+	this->vips->destroy(this->vips);
+	this->policies->destroy(this->policies);
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+kernel_interface_t *kernel_interface_create()
+{
+	private_kernel_interface_t *this = malloc_thing(private_kernel_interface_t);
+	struct sockaddr_nl addr;
+	
+	/* public functions */
+	this->public.get_spi = (status_t(*)(kernel_interface_t*,host_t*,host_t*,protocol_id_t,u_int32_t,u_int32_t*))get_spi;
+	this->public.add_sa  = (status_t(*)(kernel_interface_t *,host_t*,host_t*,u_int32_t,protocol_id_t,u_int32_t,u_int64_t,u_int64_t,algorithm_t*,algorithm_t*,prf_plus_t*,natt_conf_t*,mode_t,bool))add_sa;
+	this->public.update_sa = (status_t(*)(kernel_interface_t*,host_t*,u_int32_t,protocol_id_t,host_t*,host_t*,host_diff_t,host_diff_t))update_sa;
+	this->public.query_sa = (status_t(*)(kernel_interface_t*,host_t*,u_int32_t,protocol_id_t,u_int32_t*))query_sa;
+	this->public.del_sa = (status_t(*)(kernel_interface_t*,host_t*,u_int32_t,protocol_id_t))del_sa;
+	this->public.add_policy = (status_t(*)(kernel_interface_t*,host_t*,host_t*,traffic_selector_t*,traffic_selector_t*,policy_dir_t,protocol_id_t,u_int32_t,bool,mode_t,bool))add_policy;
+	this->public.query_policy = (status_t(*)(kernel_interface_t*,traffic_selector_t*,traffic_selector_t*,policy_dir_t,u_int32_t*))query_policy;
+	this->public.del_policy = (status_t(*)(kernel_interface_t*,traffic_selector_t*,traffic_selector_t*,policy_dir_t))del_policy;
+
+	this->public.get_interface = (char*(*)(kernel_interface_t*,host_t*))get_interface_name;
+	this->public.create_address_list = (linked_list_t*(*)(kernel_interface_t*))create_address_list_public;
+	this->public.add_ip = (status_t(*)(kernel_interface_t*,host_t*,host_t*)) add_ip;
+	this->public.del_ip = (status_t(*)(kernel_interface_t*,host_t*,host_t*)) del_ip;
+	this->public.destroy = (void(*)(kernel_interface_t*)) destroy;
+
+	/* private members */
+	this->vips = linked_list_create();
+	this->policies = linked_list_create();
+	pthread_mutex_init(&this->policies_mutex,NULL);
+	pthread_mutex_init(&this->vips_mutex,NULL);
+	
+	addr.nl_family = AF_NETLINK;
+	addr.nl_pid = 0;
+	addr.nl_groups = 0;
+	
+	/* create and bind XFRM socket */
+	this->socket_xfrm = socket(AF_NETLINK, SOCK_RAW, NETLINK_XFRM);
+	if (this->socket_xfrm <= 0)
+	{
+		charon->kill(charon, "unable to create XFRM netlink socket");
+	}
+	
+	if (bind(this->socket_xfrm, (struct sockaddr*)&addr, sizeof(addr)))
+	{
+		charon->kill(charon, "unable to bind XFRM netlink socket");
+	}
+	
+	/* create and bind RT socket */
+	this->socket_rt = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+	if (this->socket_rt <= 0)
+	{
+		charon->kill(charon, "unable to create RT netlink socket");
+	}
+	
+	if (bind(this->socket_rt, (struct sockaddr*)&addr, sizeof(addr)))
+	{
+		charon->kill(charon, "unable to bind RT netlink socket");
+	}
+	
+	/* create and bind XFRM socket for ACQUIRE & EXPIRE */
+	addr.nl_groups = XFRMGRP_ACQUIRE | XFRMGRP_EXPIRE;
+	this->socket_xfrm_events = socket(AF_NETLINK, SOCK_RAW, NETLINK_XFRM);
+	if (this->socket_xfrm_events <= 0)
+	{
+		charon->kill(charon, "unable to create XFRM event socket");
+	}
+	
+	if (bind(this->socket_xfrm_events, (struct sockaddr*)&addr, sizeof(addr)))
+	{
+		charon->kill(charon, "unable to bind XFRM event socket");
+	}
+	
+	/* create a thread receiving ACQUIRE & EXPIRE events */
+	if (pthread_create(&this->event_thread, NULL,
+					   (void*(*)(void*))receive_events, this))
+	{
+		charon->kill(charon, "unable to create xfrm event dispatcher thread");
+	}
+	
+	return &this->public;
+}
+
+/* vim: set ts=4 sw=4 noet: */
diff --git a/src/charon/kernel/kernel_interface.h b/src/charon/kernel/kernel_interface.h
new file mode 100644
index 000000000..2a3eaff7a
--- /dev/null
+++ b/src/charon/kernel/kernel_interface.h
@@ -0,0 +1,335 @@
+/**
+ * @file kernel_interface.h
+ *
+ * @brief Interface of kernel_interface_t.
+ *
+ */
+
+/*
+ * Copyright (C) 2006 Tobias Brunner, Daniel Roethlisberger
+ * Copyright (C) 2005-2006 Martin Willi
+ * Copyright (C) 2005 Jan Hutter
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.
+ */
+
+#ifndef KERNEL_INTERFACE_H_
+#define KERNEL_INTERFACE_H_
+
+typedef struct natt_conf_t natt_conf_t;
+typedef enum policy_dir_t policy_dir_t;
+typedef struct kernel_interface_t kernel_interface_t;
+
+#include <utils/host.h>
+#include <crypto/prf_plus.h>
+#include <encoding/payloads/proposal_substructure.h>
+
+/**
+ * Configuration for NAT-T
+ *
+ * @ingroup kernel
+ */
+struct natt_conf_t {
+	/** source port to use for UDP-encapsulated packets */
+	u_int16_t sport;
+	/** dest port to use for UDP-encapsulated packets */
+	u_int16_t dport;
+};
+
+/**
+ * Direction of a policy. These are equal to those
+ * defined in xfrm.h, but we want to stay implementation
+ * neutral here.
+ *
+ * @ingroup kernel
+ */
+enum policy_dir_t {
+	/** Policy for inbound traffic */
+	POLICY_IN = 0,
+	/** Policy for outbound traffic */
+	POLICY_OUT = 1,
+	/** Policy for forwarded traffic */
+	POLICY_FWD = 2,
+};
+
+/**
+ * @brief Interface to the kernel.
+ * 
+ * The kernel interface handles the communication with the kernel
+ * for SA and policy management. It allows setup of these, and provides 
+ * further the handling of kernel events.
+ * Policy information are cached in the interface. This is necessary to do
+ * reference counting. The Linux kernel does not allow the same policy
+ * installed twice, but we need this as CHILD_SA exist multiple times
+ * when rekeying. Thats why we do reference counting of policies.
+ *
+ * @b Constructors:
+ *  - kernel_interface_create()
+ *
+ * @ingroup kernel
+ */
+struct kernel_interface_t {
+
+	/**
+	 * @brief Get a SPI from the kernel.
+	 *
+	 * @warning get_spi() implicitely creates an SA with
+	 * the allocated SPI, therefore the replace flag
+	 * in add_sa() must be set when installing this SA.
+	 * 
+	 * @param this		calling object
+	 * @param src		source address of SA
+	 * @param dst		destination address of SA
+	 * @param protocol	protocol for SA (ESP/AH)
+	 * @param reqid		unique ID for this SA
+	 * @param[out] spi	allocated spi
+	 * @return
+	 * 					- SUCCESS
+	 * 					- FAILED if kernel comm failed
+	 */
+	status_t (*get_spi)(kernel_interface_t *this, host_t *src, host_t *dst, 
+						protocol_id_t protocol, u_int32_t reqid, u_int32_t *spi);
+	
+	/**
+	 * @brief Add an SA to the SAD.
+	 * 
+	 * add_sa() may update an already allocated
+	 * SPI (via get_spi). In this case, the replace
+	 * flag must be set.
+	 * This function does install a single SA for a
+	 * single protocol in one direction. The kernel-interface
+	 * gets the keys itself from the PRF, as we don't know
+	 * his algorithms and key sizes.
+	 * 
+	 * @param this			calling object
+	 * @param src			source address for this SA
+	 * @param dst			destination address for this SA
+	 * @param spi			SPI allocated by us or remote peer
+	 * @param protocol		protocol for this SA (ESP/AH)
+	 * @param reqid			unique ID for this SA
+	 * @param expire_soft	lifetime in seconds before rekeying
+	 * @param expire_hard	lieftime in seconds before delete
+	 * @param enc_alg		Algorithm to use for encryption (ESP only)
+	 * @param int_alg		Algorithm to use for integrity protection
+	 * @param prf_plus		PRF to derive keys from
+	 * @param natt			NAT-T Configuration, or NULL of no NAT-T used
+	 * @param mode			mode of the SA (tunnel, transport)
+	 * @param replace		Should an already installed SA be updated?
+	 * @return
+	 * 						- SUCCESS
+	 * 						- FAILED if kernel comm failed
+	 */
+	status_t (*add_sa) (kernel_interface_t *this,
+						host_t *src, host_t *dst, u_int32_t spi,
+						protocol_id_t protocol, u_int32_t reqid,
+						u_int64_t expire_soft, u_int64_t expire_hard,
+						algorithm_t *enc_alg, algorithm_t *int_alg,
+						prf_plus_t *prf_plus, natt_conf_t *natt,
+						mode_t mode, bool update);
+	
+	/**
+	 * @brief Update the hosts on an installed SA.
+	 *
+	 * We cannot directly update the destination address as the kernel
+	 * requires the spi, the protocol AND the destination address (and family)
+	 * to identify SAs. Therefore if the destination address changed we
+	 * create a new SA and delete the old one.
+	 *
+	 * @param this			calling object
+	 * @param dst			destination address for this SA
+	 * @param spi			SPI of the SA
+	 * @param protocol		protocol for this SA (ESP/AH)
+	 * @param new_src		new source address for this SA
+	 * @param new_dst		new destination address for this SA
+	 * @param src_changes	changes in src
+	 * @param dst_changes	changes in dst
+	 * @return
+	 * 						- SUCCESS
+	 * 						- FAILED if kernel comm failed
+	 */
+	status_t (*update_sa)(kernel_interface_t *this, host_t *dst, u_int32_t spi,
+						  protocol_id_t protocol,
+						  host_t *new_src, host_t *new_dst,
+						  host_diff_t src_changes, host_diff_t dst_changes);
+	
+	/**
+	 * @brief Query the use time of an SA.
+	 *
+	 * The use time of an SA is not the time of the last usage, but 
+	 * the time of the first usage of the SA.
+	 * 
+	 * @param this			calling object
+	 * @param dst			destination address for this SA
+	 * @param spi			SPI allocated by us or remote peer
+	 * @param protocol		protocol for this SA (ESP/AH)
+	 * @param[out] use_time	the time of this SA's last use
+	 * @return
+	 * 						- SUCCESS
+	 * 						- FAILED if kernel comm failed
+	 */
+	status_t (*query_sa) (kernel_interface_t *this, host_t *dst, u_int32_t spi, 
+						  protocol_id_t protocol, u_int32_t *use_time);
+	
+	/**
+	 * @brief Delete a previusly installed SA from the SAD.
+	 * 
+	 * @param this			calling object
+	 * @param dst			destination address for this SA
+	 * @param spi			SPI allocated by us or remote peer
+	 * @param protocol		protocol for this SA (ESP/AH)
+	 * @return
+	 * 						- SUCCESS
+	 * 						- FAILED if kernel comm failed
+	 */
+	status_t (*del_sa) (kernel_interface_t *this, host_t *dst, u_int32_t spi,
+						protocol_id_t protocol);
+	
+	/**
+	 * @brief Add a policy to the SPD.
+	 * 
+	 * A policy is always associated to an SA. Traffic which matches a
+	 * policy is handled by the SA with the same reqid.
+	 * If the update flag is set, the policy is updated with the new
+	 * src/dst addresses.
+	 * If the update flag is not set, but a such policy is already in the
+	 * kernel, the reference count to this policy is increased.
+	 * 
+	 * @param this			calling object
+	 * @param src			source address of SA
+	 * @param dst			dest address of SA
+	 * @param src_ts		traffic selector to match traffic source
+	 * @param dst_ts		traffic selector to match traffic dest
+	 * @param direction		direction of traffic, POLICY_IN, POLICY_OUT, POLICY_FWD
+	 * @param protocol		protocol to use to protect traffic (AH/ESP)
+	 * @param reqid			uniqe ID of an SA to use to enforce policy
+	 * @param high_prio		if TRUE, uses a higher priority than any with FALSE
+	 * @param mode			mode of SA (tunnel, transport)
+	 * @param update		update an existing policy, if TRUE
+	 * @return
+	 * 						- SUCCESS
+	 * 						- FAILED if kernel comm failed
+	 */
+	status_t (*add_policy) (kernel_interface_t *this,
+							host_t *src, host_t *dst,
+							traffic_selector_t *src_ts,
+							traffic_selector_t *dst_ts,
+							policy_dir_t direction, protocol_id_t protocol,
+							u_int32_t reqid, bool high_prio, 
+							mode_t mode, bool update);
+	
+	/**
+	 * @brief Query the use time of a policy.
+	 *
+	 * The use time of a policy is the time the policy was used
+	 * for the last time.
+	 * 
+	 * @param this			calling object
+	 * @param src_ts		traffic selector to match traffic source
+	 * @param dst_ts		traffic selector to match traffic dest
+	 * @param direction		direction of traffic, POLICY_IN, POLICY_OUT, POLICY_FWD
+	 * @param[out] use_time	the time of this SA's last use
+	 * @return
+	 * 						- SUCCESS
+	 * 						- FAILED if kernel comm failed
+	 */
+	status_t (*query_policy) (kernel_interface_t *this,
+							  traffic_selector_t *src_ts, 
+							  traffic_selector_t *dst_ts,
+							  policy_dir_t direction, u_int32_t *use_time);
+	
+	/**
+	 * @brief Remove a policy from the SPD.
+	 *
+	 * The kernel interface implements reference counting for policies.
+	 * If the same policy is installed multiple times (in the case of rekeying),
+	 * the reference counter is increased. del_policy() decreases the ref counter
+	 * and removes the policy only when no more references are available.
+	 *
+	 * @param this			calling object
+	 * @param src_ts		traffic selector to match traffic source
+	 * @param dst_ts		traffic selector to match traffic dest
+	 * @param direction		direction of traffic, POLICY_IN, POLICY_OUT, POLICY_FWD
+	 * @return
+	 * 						- SUCCESS
+	 * 						- FAILED if kernel comm failed
+	 */
+	status_t (*del_policy) (kernel_interface_t *this,
+							traffic_selector_t *src_ts, 
+							traffic_selector_t *dst_ts,
+							policy_dir_t direction);
+	
+	/**
+	 * @brief Get the interface name of a local address.
+	 *
+	 * @param this			calling object
+	 * @param host			address to get interface name from
+	 * @return 				allocated interface name, or NULL if not found
+	 */
+	char* (*get_interface) (kernel_interface_t *this, host_t *host);
+	
+	/**
+	 * @brief Creates a list of all local addresses.
+	 *
+	 * @param this			calling object
+	 * @return 				allocated list with host_t objects
+	 */
+	linked_list_t *(*create_address_list) (kernel_interface_t *this);
+	
+	/**
+	 * @brief Add a virtual IP to an interface.
+	 *
+	 * Virtual IPs are attached to an interface. If an IP is added multiple
+	 * times, the IP is refcounted and not removed until del_ip() was called
+	 * as many times as add_ip().
+	 * The virtual IP is attached to the interface where the iface_ip is found.
+	 *
+	 * @param this			calling object
+	 * @param virtual_ip	virtual ip address to assign
+	 * @param iface_ip		IP of an interface to attach virtual IP
+	 * @return
+	 * 						- SUCCESS
+	 * 						- FAILED if kernel comm failed
+	 */
+	status_t (*add_ip) (kernel_interface_t *this, host_t *virtual_ip,
+						host_t *iface_ip);
+	
+	/**
+	 * @brief Remove a virtual IP from an interface.
+	 *
+	 * The kernel interface uses refcounting, see add_ip().
+	 *
+	 * @param this			calling object
+	 * @param virtual_ip	virtual ip address to assign
+	 * @param iface_ip		IP of an interface to remove virtual IP from
+	 * @return
+	 * 						- SUCCESS
+	 * 						- FAILED if kernel comm failed
+	 */
+	status_t (*del_ip) (kernel_interface_t *this, host_t *virtual_ip,
+						host_t *iface_ip);
+	
+	/**
+	 * @brief Destroys a kernel_interface object.
+	 *
+	 * @param kernel_interface_t 	calling object
+	 */
+	void (*destroy) (kernel_interface_t *kernel_interface);
+};
+
+/**
+ * @brief Creates an object of type kernel_interface_t.
+ * 
+ * @ingroup kernel
+ */
+kernel_interface_t *kernel_interface_create(void);
+
+#endif /*KERNEL_INTERFACE_H_*/