kernel-pfkey: Added IPComp support

- get_cpi function was implemented to retrieve a CPI from the kernel.
- add_sa/update_sa/del_sa were updated to accommodate for IPComp SA.
- Updated add_policy_internal to update the SPD to support IPComp.

1 files changed, 138 insertions, 19 deletions

diff --git a/src/libhydra/plugins/kernel_pfkey/kernel_pfkey_ipsec.c b/src/libhydra/plugins/kernel_pfkey/kernel_pfkey_ipsec.c
index 4704d419f..d82d6720d 100644
--- a/src/libhydra/plugins/kernel_pfkey/kernel_pfkey_ipsec.c
+++ b/src/libhydra/plugins/kernel_pfkey/kernel_pfkey_ipsec.c
@@ -13,6 +13,27 @@
  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * for more details.
  */
+/*
+ * Copyright (C) 2014 Nanoteq Pty Ltd
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
 
 #include <sys/types.h>
 #include <sys/socket.h>
@@ -825,18 +846,20 @@ static kernel_algorithm_t integrity_algs[] = {
 	{END_OF_LIST,				0,							},
 };
 
-#if 0
 /**
  * Algorithms for IPComp, unused yet
  */
 static kernel_algorithm_t compression_algs[] = {
 /*	{IPCOMP_OUI,				0							}, */
 	{IPCOMP_DEFLATE,			SADB_X_CALG_DEFLATE			},
+#ifdef SADB_X_CALG_LZS
 	{IPCOMP_LZS,				SADB_X_CALG_LZS				},
+#endif
+#ifdef SADB_X_CALG_LZJH
 	{IPCOMP_LZJH,				SADB_X_CALG_LZJH			},
+#endif
 	{END_OF_LIST,				0							},
 };
-#endif
 
 /**
  * Look up a kernel algorithm ID and its key size
@@ -854,6 +877,9 @@ static int lookup_algorithm(transform_type_t type, int ikev2)
 		case INTEGRITY_ALGORITHM:
 			list = integrity_algs;
 			break;
+		case COMPRESSION_ALGORITHM:
+			list = compression_algs;
+			break;
 		default:
 			return 0;
 	}
@@ -1483,9 +1509,13 @@ static bool receive_events(private_kernel_pfkey_ipsec_t *this, int fd,
 	return TRUE;
 }
 
-METHOD(kernel_ipsec_t, get_spi, status_t,
-	private_kernel_pfkey_ipsec_t *this, host_t *src, host_t *dst,
-	u_int8_t protocol, u_int32_t reqid, u_int32_t *spi)
+/**
+ * Get an SPI for a specific protocol from the kernel.
+ */
+
+static status_t get_spi_internal(private_kernel_pfkey_ipsec_t *this,
+	host_t *src, host_t *dst, u_int8_t proto, u_int32_t min, u_int32_t max,
+	u_int32_t reqid, u_int32_t *spi)
 {
 	unsigned char request[PFKEY_BUFFER_SIZE];
 	struct sadb_msg *msg, *out;
@@ -1500,7 +1530,7 @@ METHOD(kernel_ipsec_t, get_spi, status_t,
 	msg = (struct sadb_msg*)request;
 	msg->sadb_msg_version = PF_KEY_V2;
 	msg->sadb_msg_type = SADB_GETSPI;
-	msg->sadb_msg_satype = proto2satype(protocol);
+	msg->sadb_msg_satype = proto2satype(proto);
 	msg->sadb_msg_len = PFKEY_LEN(sizeof(struct sadb_msg));
 
 	sa2 = (struct sadb_x_sa2*)PFKEY_EXT_ADD_NEXT(msg);
@@ -1515,8 +1545,8 @@ METHOD(kernel_ipsec_t, get_spi, status_t,
 	range = (struct sadb_spirange*)PFKEY_EXT_ADD_NEXT(msg);
 	range->sadb_spirange_exttype = SADB_EXT_SPIRANGE;
 	range->sadb_spirange_len = PFKEY_LEN(sizeof(struct sadb_spirange));
-	range->sadb_spirange_min = 0xc0000000;
-	range->sadb_spirange_max = 0xcFFFFFFF;
+	range->sadb_spirange_min = min;
+	range->sadb_spirange_max = max;
 	PFKEY_EXT_ADD(msg, range);
 
 	if (pfkey_send(this, msg, &out, &len) == SUCCESS)
@@ -1542,11 +1572,42 @@ METHOD(kernel_ipsec_t, get_spi, status_t,
 	return SUCCESS;
 }
 
+METHOD(kernel_ipsec_t, get_spi, status_t,
+	private_kernel_pfkey_ipsec_t *this, host_t *src, host_t *dst,
+	u_int8_t protocol, u_int32_t reqid, u_int32_t *spi)
+{
+	DBG2(DBG_KNL, "getting SPI for reqid {%u}", reqid);
+
+	if (get_spi_internal(this, src, dst, protocol,
+						 0xc0000000, 0xcFFFFFFF, reqid, spi) != SUCCESS)
+	{
+		DBG1(DBG_KNL, "unable to get SPI for reqid {%u}", reqid);
+		return FAILED;
+	}
+
+	DBG2(DBG_KNL, "got SPI %.8x for reqid {%u}", ntohl(*spi), reqid);
+	return SUCCESS;
+}
+
 METHOD(kernel_ipsec_t, get_cpi, status_t,
 	private_kernel_pfkey_ipsec_t *this, host_t *src, host_t *dst,
 	u_int32_t reqid, u_int16_t *cpi)
 {
-	return FAILED;
+	u_int32_t received_spi = 0;
+
+	DBG2(DBG_KNL, "getting CPI for reqid {%u}", reqid);
+
+	if (get_spi_internal(this, src, dst, IPPROTO_COMP,
+						 0x100, 0xEFFF, reqid, &received_spi) != SUCCESS)
+	{
+		DBG1(DBG_KNL, "unable to get CPI for reqid {%u}", reqid);
+		return FAILED;
+	}
+
+	*cpi = htons((u_int16_t)ntohl(received_spi));
+
+	DBG2(DBG_KNL, "got CPI %.4x for reqid {%u}", ntohs(*cpi), reqid);
+	return SUCCESS;
 }
 
 METHOD(kernel_ipsec_t, add_sa, status_t,
@@ -1565,6 +1626,20 @@ METHOD(kernel_ipsec_t, add_sa, status_t,
 	struct sadb_key *key;
 	size_t len;
 
+	/* if IPComp is used, we install an additional IPComp SA. if the cpi is 0
+	 * we are in the recursive call below */
+	if (ipcomp != IPCOMP_NONE && cpi != 0)
+	{
+		lifetime_cfg_t lft = {{0,0,0},{0,0,0},{0,0,0}};
+		add_sa(this, src, dst, htonl(ntohs(cpi)), IPPROTO_COMP, reqid, mark,
+			   tfc, &lft, ENCR_UNDEFINED, chunk_empty, AUTH_UNDEFINED,
+			   chunk_empty, mode, ipcomp, 0, FALSE, FALSE, FALSE, inbound,
+			   NULL, NULL);
+		ipcomp = IPCOMP_NONE;
+		/* use transport mode ESP SA, IPComp uses tunnel mode */
+		mode = MODE_TRANSPORT;
+	}
+
 	memset(&request, 0, sizeof(request));
 
 	DBG2(DBG_KNL, "adding SAD entry with SPI %.8x and reqid {%u}",
@@ -1595,9 +1670,16 @@ METHOD(kernel_ipsec_t, add_sa, status_t,
 	sa->sadb_sa_exttype = SADB_EXT_SA;
 	sa->sadb_sa_len = PFKEY_LEN(len);
 	sa->sadb_sa_spi = spi;
-	sa->sadb_sa_replay = (protocol == IPPROTO_COMP) ? 0 : 32;
-	sa->sadb_sa_auth = lookup_algorithm(INTEGRITY_ALGORITHM, int_alg);
-	sa->sadb_sa_encrypt = lookup_algorithm(ENCRYPTION_ALGORITHM, enc_alg);
+	if (protocol == IPPROTO_COMP)
+	{
+		sa->sadb_sa_encrypt = lookup_algorithm(COMPRESSION_ALGORITHM, ipcomp);
+	}
+	else
+	{
+		sa->sadb_sa_replay = 32;
+		sa->sadb_sa_auth = lookup_algorithm(INTEGRITY_ALGORITHM, int_alg);
+		sa->sadb_sa_encrypt = lookup_algorithm(ENCRYPTION_ALGORITHM, enc_alg);
+	}
 	PFKEY_EXT_ADD(msg, sa);
 
 	sa2 = (struct sadb_x_sa2*)PFKEY_EXT_ADD_NEXT(msg);
@@ -1668,11 +1750,6 @@ METHOD(kernel_ipsec_t, add_sa, status_t,
 		PFKEY_EXT_ADD(msg, key);
 	}
 
-	if (ipcomp != IPCOMP_NONE)
-	{
-		/*TODO*/
-	}
-
 #ifdef HAVE_NATT
 	if (encap)
 	{
@@ -1719,6 +1796,13 @@ METHOD(kernel_ipsec_t, update_sa, status_t,
 		return NOT_SUPPORTED;
 	}
 
+	/* if IPComp is used, we first update the IPComp SA */
+	if (cpi)
+	{
+		update_sa(this, htonl(ntohs(cpi)), IPPROTO_COMP, 0,
+				  src, dst, new_src, new_dst, FALSE, FALSE, mark);
+	}
+
 	memset(&request, 0, sizeof(request));
 
 	DBG2(DBG_KNL, "querying SAD entry with SPI %.8x", ntohl(spi));
@@ -1919,6 +2003,12 @@ METHOD(kernel_ipsec_t, del_sa, status_t,
 	struct sadb_sa *sa;
 	size_t len;
 
+	/* if IPComp was used, we first delete the additional IPComp SA */
+	if (cpi)
+	{
+		del_sa(this, src, dst, htonl(ntohs(cpi)), IPPROTO_COMP, 0, mark);
+	}
+
 	memset(&request, 0, sizeof(request));
 
 	DBG2(DBG_KNL, "deleting SAD entry with SPI %.8x", ntohl(spi));
@@ -2230,6 +2320,7 @@ static status_t add_policy_internal(private_kernel_pfkey_ipsec_t *this,
 	ipsec_sa_t *ipsec = mapping->sa;
 	pfkey_msg_t response;
 	size_t len;
+	ipsec_mode_t proto_mode;
 
 	memset(&request, 0, sizeof(request));
 
@@ -2251,15 +2342,43 @@ static status_t add_policy_internal(private_kernel_pfkey_ipsec_t *this,
 
 	/* one or more sadb_x_ipsecrequest extensions are added to the
 	 * sadb_x_policy extension */
+	proto_mode = ipsec->cfg.mode;
+
 	req = (struct sadb_x_ipsecrequest*)(pol + 1);
+
+	if (ipsec->cfg.ipcomp.transform != IPCOMP_NONE)
+	{
+		req->sadb_x_ipsecrequest_proto = IPPROTO_COMP;
+
+		/* !!! the length here MUST be in octets instead of 64 bit words */
+		req->sadb_x_ipsecrequest_len = sizeof(struct sadb_x_ipsecrequest);
+		req->sadb_x_ipsecrequest_mode = mode2kernel(ipsec->cfg.mode);
+		req->sadb_x_ipsecrequest_reqid = ipsec->cfg.reqid;
+		req->sadb_x_ipsecrequest_level = (policy->direction == POLICY_OUT) ?
+										  IPSEC_LEVEL_UNIQUE : IPSEC_LEVEL_USE;
+		if (ipsec->cfg.mode == MODE_TUNNEL)
+		{
+			len = hostcpy(req + 1, ipsec->src, FALSE);
+			req->sadb_x_ipsecrequest_len += len;
+			len = hostcpy((char*)(req + 1) + len, ipsec->dst, FALSE);
+			req->sadb_x_ipsecrequest_len += len;
+			/* use transport mode for other SAs */
+			proto_mode = MODE_TRANSPORT;
+		}
+
+		pol->sadb_x_policy_len += PFKEY_LEN(req->sadb_x_ipsecrequest_len);
+		req = (struct sadb_x_ipsecrequest*)((char*)(req) +
+											req->sadb_x_ipsecrequest_len);
+	}
+
 	req->sadb_x_ipsecrequest_proto = ipsec->cfg.esp.use ? IPPROTO_ESP
 														: IPPROTO_AH;
 	/* !!! the length here MUST be in octets instead of 64 bit words */
 	req->sadb_x_ipsecrequest_len = sizeof(struct sadb_x_ipsecrequest);
-	req->sadb_x_ipsecrequest_mode = mode2kernel(ipsec->cfg.mode);
+	req->sadb_x_ipsecrequest_mode = mode2kernel(proto_mode);
 	req->sadb_x_ipsecrequest_reqid = ipsec->cfg.reqid;
 	req->sadb_x_ipsecrequest_level = IPSEC_LEVEL_UNIQUE;
-	if (ipsec->cfg.mode == MODE_TUNNEL)
+	if (proto_mode == MODE_TUNNEL)
 	{
 		len = hostcpy(req + 1, ipsec->src, FALSE);
 		req->sadb_x_ipsecrequest_len += len;