support gre key in ikev1tteras

this implements gre key negotiation in ikev1 similarly to the
ipsec-tools patch in alpine.

the from/to port pair is internally used as gre key for gre
protocol traffic selectors. since from/to pairs 0/0xffff and
0xffff/0 have special meaning, the gre keys 0xffff and 0xffff0000
will not work.

this is not standard compliant, and should probably not be upstreamed
or used widely, but it is applied for interoperability with alpine
racoon for the time being.

9 files changed, 171 insertions, 39 deletions

diff --git a/src/libcharon/encoding/payloads/id_payload.c b/src/libcharon/encoding/payloads/id_payload.c
index ae0b19a9d..43f28fc20 100644
--- a/src/libcharon/encoding/payloads/id_payload.c
+++ b/src/libcharon/encoding/payloads/id_payload.c
@@ -245,18 +245,20 @@ METHOD(id_payload_t, get_identification, identification_t*,
  * Create a traffic selector from an range ID
  */
 static traffic_selector_t *get_ts_from_range(private_id_payload_t *this,
-											 ts_type_t type)
+											 ts_type_t type,
+											 uint16_t from_port, uint16_t to_port)
 {
 	return traffic_selector_create_from_bytes(this->protocol_id, type,
-		chunk_create(this->id_data.ptr, this->id_data.len / 2), this->port,
-		chunk_skip(this->id_data, this->id_data.len / 2), this->port ?: 65535);
+		chunk_create(this->id_data.ptr, this->id_data.len / 2), from_port,
+		chunk_skip(this->id_data, this->id_data.len / 2), to_port);
 }
 
 /**
  * Create a traffic selector from an subnet ID
  */
 static traffic_selector_t *get_ts_from_subnet(private_id_payload_t *this,
-											  ts_type_t type)
+											  ts_type_t type,
+											  uint16_t from_port, uint16_t to_port)
 {
 	traffic_selector_t *ts;
 	chunk_t net, netmask;
@@ -269,7 +271,7 @@ static traffic_selector_t *get_ts_from_subnet(private_id_payload_t *this,
 		netmask.ptr[i] = (netmask.ptr[i] ^ 0xFF) | net.ptr[i];
 	}
 	ts = traffic_selector_create_from_bytes(this->protocol_id, type,
-								net, this->port, netmask, this->port ?: 65535);
+								net, from_port, netmask, to_port);
 	chunk_free(&netmask);
 	return ts;
 }
@@ -278,51 +280,76 @@ static traffic_selector_t *get_ts_from_subnet(private_id_payload_t *this,
  * Create a traffic selector from an IP ID
  */
 static traffic_selector_t *get_ts_from_ip(private_id_payload_t *this,
-										  ts_type_t type)
+										  ts_type_t type,
+										  uint16_t from_port, uint16_t to_port)
 {
 	return traffic_selector_create_from_bytes(this->protocol_id, type,
-				this->id_data, this->port, this->id_data, this->port ?: 65535);
+				this->id_data, from_port, this->id_data, to_port);
 }
 
 METHOD(id_payload_t, get_ts, traffic_selector_t*,
-	private_id_payload_t *this)
+	private_id_payload_t *this, id_payload_t *other_, bool initiator)
 {
+	private_id_payload_t *other = (private_id_payload_t *) other_;
+	uint16_t from_port, to_port;
+
+	if (other && this->protocol_id == IPPROTO_GRE && other->protocol_id == IPPROTO_GRE)
+	{
+		if (initiator)
+		{
+			from_port = this->port;
+			to_port = other->port;
+		}
+		else
+		{
+			from_port = other->port;
+			to_port = this->port;
+		}
+		if (from_port == 0 && to_port == 0)
+			to_port = 0xffff;
+	}
+	else
+	{
+		from_port = this->port;
+		to_port = this->port ?: 0xffff;
+	}
+
 	switch (this->id_type)
 	{
 		case ID_IPV4_ADDR_SUBNET:
 			if (this->id_data.len == 8)
 			{
-				return get_ts_from_subnet(this, TS_IPV4_ADDR_RANGE);
+				return get_ts_from_subnet(this, TS_IPV4_ADDR_RANGE, from_port, to_port);
 			}
 			break;
 		case ID_IPV6_ADDR_SUBNET:
 			if (this->id_data.len == 32)
 			{
-				return get_ts_from_subnet(this, TS_IPV6_ADDR_RANGE);
+				return get_ts_from_subnet(this, TS_IPV6_ADDR_RANGE, from_port, to_port);
 			}
 			break;
 		case ID_IPV4_ADDR_RANGE:
 			if (this->id_data.len == 8)
 			{
-				return get_ts_from_range(this, TS_IPV4_ADDR_RANGE);
+				return get_ts_from_range(this, TS_IPV4_ADDR_RANGE, from_port, to_port);
 			}
 			break;
 		case ID_IPV6_ADDR_RANGE:
 			if (this->id_data.len == 32)
 			{
-				return get_ts_from_range(this, TS_IPV6_ADDR_RANGE);
+				return get_ts_from_range(this, TS_IPV6_ADDR_RANGE, from_port, to_port);
 			}
 			break;
 		case ID_IPV4_ADDR:
 			if (this->id_data.len == 4)
 			{
-				return get_ts_from_ip(this, TS_IPV4_ADDR_RANGE);
+				return get_ts_from_ip(this, TS_IPV4_ADDR_RANGE, from_port, to_port);
 			}
 			break;
 		case ID_IPV6_ADDR:
 			if (this->id_data.len == 16)
 			{
-				return get_ts_from_ip(this, TS_IPV6_ADDR_RANGE);
+				return get_ts_from_ip(this, TS_IPV6_ADDR_RANGE, from_port, to_port);
 			}
 			break;
 		default:
@@ -397,7 +424,7 @@ id_payload_t *id_payload_create_from_identification(payload_type_t type,
 /*
  * Described in header.
  */
-id_payload_t *id_payload_create_from_ts(traffic_selector_t *ts)
+id_payload_t *id_payload_create_from_ts(traffic_selector_t *ts, bool initiator)
 {
 	private_id_payload_t *this;
 	uint8_t mask;
@@ -460,8 +487,17 @@ id_payload_t *id_payload_create_from_ts(traffic_selector_t *ts)
 							ts->get_from_address(ts), ts->get_to_address(ts));
 		net->destroy(net);
 	}
-	this->port = ts->get_from_port(ts);
 	this->protocol_id = ts->get_protocol(ts);
+	if (initiator || this->protocol_id != IPPROTO_GRE)
+	{
+		this->port = ts->get_from_port(ts);
+	}
+	else
+	{
+		this->port = ts->get_to_port(ts);
+		if (this->port == 0xffff && ts->get_from_port(ts) == 0)
+			this->port = 0;
+	}
 	this->payload_length += this->id_data.len;
 
 	return &this->public;
diff --git a/src/libcharon/encoding/payloads/id_payload.h b/src/libcharon/encoding/payloads/id_payload.h
index df1d07553..7558e91f2 100644
--- a/src/libcharon/encoding/payloads/id_payload.h
+++ b/src/libcharon/encoding/payloads/id_payload.h
@@ -48,11 +48,11 @@ struct id_payload_t {
 	identification_t *(*get_identification) (id_payload_t *this);
 
 	/**
-	 * Creates a traffic selector form a ID_ADDR_SUBNET/RANGE identity.
+	 * Creates a traffic selector form a ID_ADDR_SUBNET/RANGE identity pair.
 	 *
 	 * @return				traffic selector, NULL on failure
 	 */
-	traffic_selector_t* (*get_ts)(id_payload_t *this);
+	traffic_selector_t* (*get_ts)(id_payload_t *this, id_payload_t *other, bool initiator);
 
 	/**
 	 * Get encoded payload without fixed payload header (used for IKEv1).
@@ -91,6 +91,6 @@ id_payload_t *id_payload_create_from_identification(payload_type_t type,
  * @param ts		traffic selector
  * @return			PLV1_ID id_paylad_t object.
  */
-id_payload_t *id_payload_create_from_ts(traffic_selector_t *ts);
+id_payload_t *id_payload_create_from_ts(traffic_selector_t *ts, bool initiator);
 
 #endif /** ID_PAYLOAD_H_ @}*/
diff --git a/src/libcharon/plugins/kernel_netlink/kernel_netlink_ipsec.c b/src/libcharon/plugins/kernel_netlink/kernel_netlink_ipsec.c
index 4e79dfced..27ea824ee 100644
--- a/src/libcharon/plugins/kernel_netlink/kernel_netlink_ipsec.c
+++ b/src/libcharon/plugins/kernel_netlink/kernel_netlink_ipsec.c
@@ -824,7 +824,18 @@ static struct xfrm_selector ts2selector(traffic_selector_t *src,
 	ts2subnet(src, &sel.saddr, &sel.prefixlen_s);
 	ts2ports(dst, &sel.dport, &sel.dport_mask);
 	ts2ports(src, &sel.sport, &sel.sport_mask);
-	if ((sel.proto == IPPROTO_ICMP || sel.proto == IPPROTO_ICMPV6) &&
+	if (sel.proto == IPPROTO_GRE)
+	{
+		sel.sport = htons(src->get_from_port(src));
+		sel.dport = htons(src->get_to_port(src));
+		sel.sport_mask = ~0;
+		sel.dport_mask = ~0;
+		if (sel.sport == htons(0) && sel.dport == htons(0xffff))
+		{
+			sel.sport = sel.dport = sel.sport_mask = sel.dport_mask = 0;
+		}
+	}
+	else if ((sel.proto == IPPROTO_ICMP || sel.proto == IPPROTO_ICMPV6) &&
 		(sel.dport || sel.sport))
 	{
 		/* the kernel expects the ICMP type and code in the source and
@@ -848,7 +859,7 @@ static traffic_selector_t* selector2ts(struct xfrm_selector *sel, bool src)
 {
 	u_char *addr;
 	uint8_t prefixlen;
-	uint16_t port = 0;
+	uint16_t from_port = 0, to_port = 65535;
 	host_t *host = NULL;
 
 	if (src)
@@ -857,7 +868,7 @@ static traffic_selector_t* selector2ts(struct xfrm_selector *sel, bool src)
 		prefixlen = sel->prefixlen_s;
 		if (sel->sport_mask)
 		{
-			port = ntohs(sel->sport);
+			from_port = to_port = ntohs(sel->sport);
 		}
 	}
 	else
@@ -866,14 +877,27 @@ static traffic_selector_t* selector2ts(struct xfrm_selector *sel, bool src)
 		prefixlen = sel->prefixlen_d;
 		if (sel->dport_mask)
 		{
-			port = ntohs(sel->dport);
+			from_port = to_port = ntohs(sel->dport);
+		}
+	}
+	if (sel->proto == IPPROTO_GRE)
+	{
+		if (sel->sport_mask)
+		{
+			from_port = ntohs(sel->sport);
+			to_port = ntohs(sel->dport);
+		}
+		else
+		{
+			from_port = 0;
+			to_port = 0xffff;
 		}
 	}
-	if (sel->proto == IPPROTO_ICMP || sel->proto == IPPROTO_ICMPV6)
+	else if (sel->proto == IPPROTO_ICMP || sel->proto == IPPROTO_ICMPV6)
 	{	/* convert ICMP[v6] message type and code as supplied by the kernel in
 		 * source and destination ports (both in network order) */
-		port = (sel->sport >> 8) | (sel->dport & 0xff00);
-		port = ntohs(port);
+		from_port = (sel->sport >> 8) | (sel->dport & 0xff00);
+		from_port = to_port = ntohs(from_port);
 	}
 	/* The Linux 2.6 kernel does not set the selector's family field,
 	 * so as a kludge we additionally test the prefix length.
@@ -890,7 +914,7 @@ static traffic_selector_t* selector2ts(struct xfrm_selector *sel, bool src)
 	if (host)
 	{
 		return traffic_selector_create_from_subnet(host, prefixlen,
-											sel->proto, port, port ?: 65535);
+											sel->proto, from_port, to_port);
 	}
 	return NULL;
 }
diff --git a/src/libcharon/plugins/stroke/stroke_config.c b/src/libcharon/plugins/stroke/stroke_config.c
index ac0129210..b2060e2eb 100644
--- a/src/libcharon/plugins/stroke/stroke_config.c
+++ b/src/libcharon/plugins/stroke/stroke_config.c
@@ -936,6 +936,11 @@ static bool parse_protoport(char *token, uint16_t *from_port,
 		*from_port = 0xffff;
 		*to_port = 0;
 	}
+	else if (*port && *protocol == IPPROTO_GRE)
+	{
+		p = strtol(port, &endptr, 0);
+		traffic_selector_split_grekey(p, from_port, to_port);
+	}
 	else if (*port)
 	{
 		svc = getservbyname(port, NULL);
diff --git a/src/libcharon/plugins/unity/unity_narrow.c b/src/libcharon/plugins/unity/unity_narrow.c
index 227d24be8..7749d8c2c 100644
--- a/src/libcharon/plugins/unity/unity_narrow.c
+++ b/src/libcharon/plugins/unity/unity_narrow.c
@@ -247,7 +247,7 @@ METHOD(listener_t, message, bool,
 			if (!first)
 			{
 				id_payload = (id_payload_t*)payload;
-				tsr = id_payload->get_ts(id_payload);
+				tsr = id_payload->get_ts(id_payload, NULL, FALSE);
 				break;
 			}
 			first = FALSE;
diff --git a/src/libcharon/plugins/vici/vici_config.c b/src/libcharon/plugins/vici/vici_config.c
index b3e835f59..710b57994 100644
--- a/src/libcharon/plugins/vici/vici_config.c
+++ b/src/libcharon/plugins/vici/vici_config.c
@@ -680,8 +680,13 @@ CALLBACK(parse_ts, bool,
 		}
 		else if (*port && !streq(port, "any"))
 		{
-			svc = getservbyname(port, NULL);
-			if (svc)
+			if (proto == IPPROTO_GRE)
+			{
+				p = strtol(port, &end, 0);
+				if (*end) return FALSE;
+				traffic_selector_split_grekey(p, &from, &to);
+			}
+			else if ((svc = getservbyname(port, NULL)) != NULL)
 			{
 				from = to = ntohs(svc->s_port);
 			}
diff --git a/src/libcharon/sa/ikev1/tasks/quick_mode.c b/src/libcharon/sa/ikev1/tasks/quick_mode.c
index 49b476ad8..315a29abe 100644
--- a/src/libcharon/sa/ikev1/tasks/quick_mode.c
+++ b/src/libcharon/sa/ikev1/tasks/quick_mode.c
@@ -567,9 +567,9 @@ static void add_ts(private_quick_mode_t *this, message_t *message)
 {
 	id_payload_t *id_payload;
 
-	id_payload = id_payload_create_from_ts(this->tsi);
+	id_payload = id_payload_create_from_ts(this->tsi, TRUE);
 	message->add_payload(message, &id_payload->payload_interface);
-	id_payload = id_payload_create_from_ts(this->tsr);
+	id_payload = id_payload_create_from_ts(this->tsr, FALSE);
 	message->add_payload(message, &id_payload->payload_interface);
 }
 
@@ -580,7 +580,7 @@ static bool get_ts(private_quick_mode_t *this, message_t *message)
 {
 	traffic_selector_t *tsi = NULL, *tsr = NULL;
 	enumerator_t *enumerator;
-	id_payload_t *id_payload;
+	id_payload_t *idi = NULL, *idr = NULL;
 	payload_t *payload;
 	host_t *hsi, *hsr;
 	bool first = TRUE;
@@ -590,20 +590,22 @@ static bool get_ts(private_quick_mode_t *this, message_t *message)
 	{
 		if (payload->get_type(payload) == PLV1_ID)
 		{
-			id_payload = (id_payload_t*)payload;
-
 			if (first)
 			{
-				tsi = id_payload->get_ts(id_payload);
+				idi = (id_payload_t*)payload;
 				first = FALSE;
 			}
 			else
 			{
-				tsr = id_payload->get_ts(id_payload);
+				idr = (id_payload_t*)payload;
 				break;
 			}
 		}
 	}
+	if (idi && idr) {
+		tsi = idi->get_ts(idi, idr, TRUE);
+		tsr = idr->get_ts(idr, idi, FALSE);
+	}
 	enumerator->destroy(enumerator);
 
 	/* create host2host selectors if ID payloads missing */
diff --git a/src/libstrongswan/selectors/traffic_selector.c b/src/libstrongswan/selectors/traffic_selector.c
index 12f160224..00c78a91b 100644
--- a/src/libstrongswan/selectors/traffic_selector.c
+++ b/src/libstrongswan/selectors/traffic_selector.c
@@ -199,6 +199,14 @@ static int print_icmp(printf_hook_data_t *data, uint16_t port)
 }
 
 /**
+ * Print GRE key
+ */
+static int print_grekey(printf_hook_data_t *data, uint16_t from_port, uint16_t to_port)
+{
+	return print_in_hook(data, "%d", traffic_selector_grekey(from_port, to_port));
+}
+
+/**
  * Described in header.
  */
 int traffic_selector_printf_hook(printf_hook_data_t *data,
@@ -302,7 +310,11 @@ int traffic_selector_printf_hook(printf_hook_data_t *data,
 	/* build port string */
 	if (has_ports)
 	{
-		if (this->from_port == this->to_port)
+		if (this->protocol == IPPROTO_GRE)
+		{
+			written += print_grekey(data, this->from_port, this->to_port);
+		}
+		else if (this->from_port == this->to_port)
 		{
 			struct servent *serv;
 
@@ -376,7 +388,24 @@ METHOD(traffic_selector_t, get_subset, traffic_selector_t*,
 	/* select protocol, which is not zero */
 	protocol = max(this->protocol, other->protocol);
 
-	if ((is_opaque(this) && is_opaque(other)) ||
+	if (this->protocol == IPPROTO_GRE)
+	{
+		if (is_any(this))
+		{
+			from_port = other->from_port;
+			to_port = other->to_port;
+		}
+		else if (is_any(other) ||
+			 (this->from_port == other->from_port &&
+			  this->to_port == other->to_port))
+		{
+			from_port = this->from_port;
+			to_port = this->to_port;
+		}
+		else
+			return NULL;
+	}
+	else if ((is_opaque(this) && is_opaque(other)) ||
 		(is_opaque(this) && is_any(other)) ||
 		(is_opaque(other) && is_any(this)))
 	{
diff --git a/src/libstrongswan/selectors/traffic_selector.h b/src/libstrongswan/selectors/traffic_selector.h
index a9f78303c..5b08e708c 100644
--- a/src/libstrongswan/selectors/traffic_selector.h
+++ b/src/libstrongswan/selectors/traffic_selector.h
@@ -120,6 +120,9 @@ struct traffic_selector_t {
 	 * 8 bits and the code in the least significant 8 bits.  Use the utility
 	 * functions to extract them.
 	 *
+	 * If the protocol is GRE, the high 16-bits of the 32-bit GRE key is stored
+	 * in the from port. Use the utility function to merge and split them.
+	 *
 	 * @return			port
 	 */
 	uint16_t (*get_from_port)(traffic_selector_t *this);
@@ -134,6 +137,9 @@ struct traffic_selector_t {
 	 * 8 bits and the code in the least significant 8 bits.  Use the utility
 	 * functions to extract them.
 	 *
+	 * If the protocol is GRE, the low 16-bits of the 32-bit GRE key is stored
+	 * in the to port. Use the utility function to merge and split them.
+	 *
 	 * @return			port
 	 */
 	uint16_t (*get_to_port)(traffic_selector_t *this);
@@ -278,6 +284,31 @@ int traffic_selector_cmp(traffic_selector_t *a, traffic_selector_t *b,
 						 void *opts);
 
 /**
+ * Reconstruct the 32-bit GRE KEY in host order from a from/to ports.
+ *
+ * @param from_port			port number in host order
+ * @param to_port			port number in host order
+ * @return				GRE KEY in host order
+ */
+static inline uint32_t traffic_selector_grekey(uint16_t from_port, uint16_t to_port)
+{
+	return (from_port << 16) | to_port;
+}
+
+/**
+ * Split 32-bit GRE KEY in host order to from/to ports.
+ *
+ * @param grekey			grekey in host order
+ * @param from_port			from port in host order
+ * @param to_port			to port in host order
+ */
+static inline void traffic_selector_split_grekey(uint32_t grekey, uint16_t *from_port, uint16_t *to_port)
+{
+	*from_port = grekey >> 16;
+	*to_port = grekey & 0xffff;
+}
+
+/**
  * Create a new traffic selector using human readable params.
  *
  * If protocol is ICMP or ICMPv6 the ports are interpreted as follows:  If they