support of error_offset in PA-TNC INVALID PARAMETER error messages

src/libimcv/ietf/ietf_attr_pa_tnc_error.c

@@ -32,7 +32,7 @@ typedef struct private_ietf_attr_pa_tnc_error_t private_ietf_attr_pa_tnc_error_t
 /**
  * PA-TNC Error Attribute Type  (see section 4.2.8 of RFC 5792)
  *
- *                        1                   2                   3
+ *                       1                   2                   3
  *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  *
  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
@@ -50,7 +50,7 @@ typedef struct private_ietf_attr_pa_tnc_error_t private_ietf_attr_pa_tnc_error_t
 /**
  * All Error Types return the first 8 bytes of the erroneous PA-TNC message
  *
- *                        1                   2                   3
+ *                       1                   2                   3
  *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  *  |    Version    |            Copy of Reserved                   |
@@ -61,10 +61,19 @@ typedef struct private_ietf_attr_pa_tnc_error_t private_ietf_attr_pa_tnc_error_t
 
 #define PA_ERROR_MSG_INFO_SIZE		8
 
+/**
+ * "Invalid Parameter" Error Code
+ *                       1                   2                   3
+ *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |                             Offset                            |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+
 /**
  * "Version Not Supported" Error Code
  *
- *                        1                   2                   3
+ *                       1                   2                   3
  *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  *  |  Max Version  |  Min Version  |            Reserved           |
@@ -137,6 +146,11 @@ struct private_ietf_attr_pa_tnc_error_t {
 	 */
 	chunk_t attr_info;
 
+	/**
+	 * PA-TNC error offset
+	 */
+	u_int32_t error_offset;
+
 	/**
 	 * Reference count
 	 */
@@ -187,6 +201,7 @@ METHOD(pa_tnc_attr_t, build, void,
 	switch (this->error_code)
 	{
 		case PA_ERROR_INVALID_PARAMETER:
+			writer->write_uint32(writer, this->error_offset);
 			break;
 		case PA_ERROR_VERSION_NOT_SUPPORTED:
 			writer->write_uint8 (writer, PA_TNC_VERSION);
@@ -205,13 +220,16 @@ METHOD(pa_tnc_attr_t, build, void,
 }
 
 METHOD(pa_tnc_attr_t, process, status_t,
-	private_ietf_attr_pa_tnc_error_t *this)
+	private_ietf_attr_pa_tnc_error_t *this, u_int32_t *offset)
 {
 	bio_reader_t *reader;
 	u_int8_t reserved;
 
 	if (this->value.len < PA_ERROR_HEADER_SIZE + PA_ERROR_MSG_INFO_SIZE)
 	{
+		DBG1(DBG_TNC, "insufficient data for PA-TNC error header and "
+					  "error information");
+		*offset = 0;
 		return FAILED;
 	}
 	reader = bio_reader_create(this->value);
@@ -223,6 +241,15 @@ METHOD(pa_tnc_attr_t, process, status_t,
 
 	switch (this->error_code)
 	{
+		case PA_ERROR_INVALID_PARAMETER:
+			if (!reader->read_uint32(reader, &this->error_offset))
+			{
+				reader->destroy(reader);
+				DBG1(DBG_TNC, "insufficient data for error offset field");
+				*offset = PA_ERROR_HEADER_SIZE + PA_ERROR_MSG_INFO_SIZE;
+				return FAILED;
+			}
+			break;
 		case PA_ERROR_ATTR_TYPE_NOT_SUPPORTED:
 			if (!reader->read_data(reader, PA_ERROR_ATTR_INFO_SIZE,
 										   &this->attr_info))
@@ -230,6 +257,7 @@ METHOD(pa_tnc_attr_t, process, status_t,
 				reader->destroy(reader);
 				DBG1(DBG_TNC, "insufficient data for unsupported attribute "
 							  "information");
+				*offset = PA_ERROR_HEADER_SIZE + PA_ERROR_MSG_INFO_SIZE;
 				return FAILED;
 			}
 			this->attr_info = chunk_clone(this->attr_info);
@@ -291,6 +319,12 @@ METHOD(ietf_attr_pa_tnc_error_t, set_attr_info, void,
 	this->attr_info = chunk_clone(attr_info);
 }
 
+METHOD(ietf_attr_pa_tnc_error_t, get_offset, u_int32_t,
+	private_ietf_attr_pa_tnc_error_t *this)
+{
+	return this->error_offset;
+}
+
 /**
  * Described in header.
  */
@@ -321,6 +355,7 @@ pa_tnc_attr_t *ietf_attr_pa_tnc_error_create(pen_t vendor_id,
 			.get_msg_info = _get_msg_info,
 			.get_attr_info = _get_attr_info,
 			.set_attr_info = _set_attr_info,
+			.get_offset = _get_offset,
 		},
 		.vendor_id = PEN_IETF,
 		.type = IETF_ATTR_PA_TNC_ERROR,
@@ -333,6 +368,51 @@ pa_tnc_attr_t *ietf_attr_pa_tnc_error_create(pen_t vendor_id,
 	return &this->public.pa_tnc_attribute;
 }
 
+/**
+ * Described in header.
+ */
+pa_tnc_attr_t *ietf_attr_pa_tnc_error_create_with_offset(pen_t vendor_id,
+														 u_int32_t error_code,
+														 chunk_t msg_info,
+														 u_int32_t error_offset)
+{
+	private_ietf_attr_pa_tnc_error_t *this;
+
+	/* the first 8 bytes of the erroneous PA-TNC message are sent back */
+	msg_info.len = PA_ERROR_MSG_INFO_SIZE;
+
+	INIT(this,
+		.public = {
+			.pa_tnc_attribute = {
+				.get_vendor_id = _get_vendor_id,
+				.get_type = _get_type,
+				.get_value = _get_value,
+				.get_noskip_flag = _get_noskip_flag,
+				.set_noskip_flag = _set_noskip_flag,
+				.build = _build,
+				.process = _process,
+				.get_ref = _get_ref,
+				.destroy = _destroy,
+			},
+			.get_vendor_id = _get_error_vendor_id,
+			.get_error_code = _get_error_code,
+			.get_msg_info = _get_msg_info,
+			.get_attr_info = _get_attr_info,
+			.set_attr_info = _set_attr_info,
+			.get_offset = _get_offset,
+		},
+		.vendor_id = PEN_IETF,
+		.type = IETF_ATTR_PA_TNC_ERROR,
+		.error_vendor_id = vendor_id,
+		.error_code = error_code,
+		.msg_info = chunk_clone(msg_info),
+		.error_offset = error_offset,
+		.ref = 1,
+	);
+
+	return &this->public.pa_tnc_attribute;
+}
+
 /**
  * Described in header.
  */
@@ -356,6 +436,7 @@ pa_tnc_attr_t *ietf_attr_pa_tnc_error_create_from_data(chunk_t data)
 			.get_msg_info = _get_msg_info,
 			.get_attr_info = _get_attr_info,
 			.set_attr_info = _set_attr_info,
+			.get_offset = _get_offset,
 		},
 		.vendor_id = PEN_IETF,
 		.type = IETF_ATTR_PA_TNC_ERROR,

src/libimcv/ietf/ietf_attr_pa_tnc_error.h

@@ -88,6 +88,14 @@ struct ietf_attr_pa_tnc_error_t {
 	 * @param attr_info		PA-TNC message info
 	 */
 	void (*set_attr_info)(ietf_attr_pa_tnc_error_t *this, chunk_t attr_info);
+
+	/**
+	 * Get the PA-TNC error offset
+	 *
+	 * @return				PA-TNC error offset
+	 */
+	u_int32_t (*get_offset)(ietf_attr_pa_tnc_error_t *this);
+
 };
 
 /**
@@ -102,6 +110,20 @@ pa_tnc_attr_t* ietf_attr_pa_tnc_error_create(pen_t vendor_id,
 											 u_int32_t error_code,
 											 chunk_t header);
 
+/**
+ * Creates an ietf_attr_pa_tnc_error_t object from an error code with offset
+ *
+ * @param vendor_id			PA-TNC error code vendor ID
+ * @param error_code		PA-TNC error code
+ * @param header			PA-TNC message header (first 8 bytes)
+ * @param error_offset		PA-TNC error offset in bytes
+ * 
+ */
+pa_tnc_attr_t* ietf_attr_pa_tnc_error_create_with_offset(pen_t vendor_id,
+														 u_int32_t error_code,
+														 chunk_t header,
+														 u_int32_t error_offset);
+
 /**
  * Creates an ietf_attr_pa_tnc_error_t object from received data
  *

src/libimcv/ietf/ietf_attr_port_filter.c

@@ -137,7 +137,7 @@ METHOD(pa_tnc_attr_t, build, void,
 }
 
 METHOD(pa_tnc_attr_t, process, status_t,
-	private_ietf_attr_port_filter_t *this)
+	private_ietf_attr_port_filter_t *this, u_int32_t *offset)
 {
 	bio_reader_t *reader;
 	port_entry_t *entry;
@@ -145,6 +145,9 @@ METHOD(pa_tnc_attr_t, process, status_t,
 
 	if (this->value.len % PORT_FILTER_ENTRY_SIZE)
 	{
+		DBG1(DBG_TNC, "ietf port filter attribute value is not a multiple of %d",
+			 PORT_FILTER_ENTRY_SIZE);
+		*offset = 0;
 		return FAILED;
 	}
 	reader = bio_reader_create(this->value);

src/libimcv/ita/ita_attr_command.c

@@ -99,7 +99,7 @@ METHOD(pa_tnc_attr_t, build, void,
 }
 
 METHOD(pa_tnc_attr_t, process, status_t,
-	private_ita_attr_command_t *this)
+	private_ita_attr_command_t *this, u_int32_t *offset)
 {
 	this->command = malloc(this->value.len + 1);
 	memcpy(this->command, this->value.ptr, this->value.len);

src/libimcv/pa_tnc/pa_tnc_attr.h

@@ -75,9 +75,10 @@ struct pa_tnc_attr_t {
 	/**
 	 * Process the value of an PA-TNC attribute to extract its parameters
 	 *
+	 * @param					relative error offset within attribute body
 	 * @return					result status
 	 */
-	status_t (*process)(pa_tnc_attr_t *this);
+	status_t (*process)(pa_tnc_attr_t *this, u_int32_t *offset);
 
 	/**
 	 * Get a new reference to the PA-TNC attribute

src/libimcv/pa_tnc/pa_tnc_msg.c

@@ -173,7 +173,7 @@ METHOD(pa_tnc_msg_t, process, status_t,
 	bio_reader_t *reader;
 	pa_tnc_attr_t *error;
 	u_int8_t version;
-	u_int32_t reserved;
+	u_int32_t reserved, offset, attr_offset;
 
 	/* process message header */
 	if (this->encoding.len < PA_TNC_HEADER_SIZE)
@@ -196,6 +196,9 @@ METHOD(pa_tnc_msg_t, process, status_t,
 		goto err;
 	}
 	
+	/* offset of the first PA-TNC attribute in the PA-TNC message */
+	offset = PA_TNC_HEADER_SIZE;
+
 	/* pre-process PA-TNC attributes */
 	while (reader->remaining(reader) >= PA_TNC_ATTR_HEADER_SIZE)
 	{
@@ -229,17 +232,18 @@ METHOD(pa_tnc_msg_t, process, status_t,
 		{
 			DBG1(DBG_TNC, "%u bytes too small for PA-TNC attribute length",
 						   length);
-			error = ietf_attr_pa_tnc_error_create(PEN_IETF,
+			error = ietf_attr_pa_tnc_error_create_with_offset(PEN_IETF,
-						PA_ERROR_INVALID_PARAMETER, this->encoding);
+						PA_ERROR_INVALID_PARAMETER, this->encoding,
+						offset + PA_TNC_ATTR_INFO_SIZE);
 			goto err;
 		}
-		length -= PA_TNC_ATTR_HEADER_SIZE;
 
-		if (!reader->read_data(reader, length , &value))
+		if (!reader->read_data(reader, length - PA_TNC_ATTR_HEADER_SIZE, &value))
 		{
 			DBG1(DBG_TNC, "insufficient bytes for PA-TNC attribute value");
-			error = ietf_attr_pa_tnc_error_create(PEN_IETF,
+			error = ietf_attr_pa_tnc_error_create_with_offset(PEN_IETF,
-						PA_ERROR_INVALID_PARAMETER, this->encoding);
+						PA_ERROR_INVALID_PARAMETER, this->encoding,
+						offset + PA_TNC_ATTR_INFO_SIZE);
 			goto err; 
 		} 
 		DBG3(DBG_TNC, "%B", &value);
@@ -259,17 +263,27 @@ METHOD(pa_tnc_msg_t, process, status_t,
 			else
 			{
 				DBG1(DBG_TNC, "skipping unsupported PA-TNC attribute");
+				offset += length;
+				continue;
 			}
 		}
 
-		if (attr->process(attr) != SUCCESS)
+		if (attr->process(attr, &attr_offset) != SUCCESS)
 		{
 			attr->destroy(attr);
-			error = ietf_attr_pa_tnc_error_create(PEN_IETF,
+			if (vendor_id == PEN_IETF && type == IETF_ATTR_PA_TNC_ERROR)
-						PA_ERROR_INVALID_PARAMETER, this->encoding);
+			{
+				/* error while processing a PA-TNC error attribute - abort */
+				reader->destroy(reader);
+				return FAILED;
+			}
+			error = ietf_attr_pa_tnc_error_create_with_offset(PEN_IETF,
+						PA_ERROR_INVALID_PARAMETER, this->encoding,
+						offset + PA_TNC_ATTR_HEADER_SIZE + attr_offset);
 			goto err;
 		}
 		add_attribute(this, attr);
+		offset += length;
 	}
 
 	if (reader->remaining(reader) == 0)
@@ -277,6 +291,9 @@ METHOD(pa_tnc_msg_t, process, status_t,
 		reader->destroy(reader);
 		return SUCCESS;
 	}
+	DBG1(DBG_TNC, "insufficient bytes for PA-TNC attribute header");
+	error = ietf_attr_pa_tnc_error_create_with_offset(PEN_IETF,
+				PA_ERROR_INVALID_PARAMETER, this->encoding, offset);
 
 err:
 	reader->destroy(reader);

src/libimcv/plugins/imc_scanner/imc_scanner.c

@@ -297,6 +297,7 @@ TNC_Result TNC_IMC_ReceiveMessage(TNC_IMCID imc_id,
 		ietf_attr_pa_tnc_error_t *error_attr;
 		pa_tnc_error_code_t error_code;
 		chunk_t msg_info, attr_info;
+		u_int32_t offset;
 
 		if (attr->get_vendor_id(attr) != PEN_IETF &&
 			attr->get_type(attr) != IETF_ATTR_PA_TNC_ERROR)
@@ -312,6 +313,10 @@ TNC_Result TNC_IMC_ReceiveMessage(TNC_IMCID imc_id,
 
 		switch (error_code)
 		{
+			case PA_ERROR_INVALID_PARAMETER:
+				offset = error_attr->get_offset(error_attr);
+				DBG1(DBG_IMC, "  occurred at offset of %u bytes", offset);
+				break;
 			case PA_ERROR_ATTR_TYPE_NOT_SUPPORTED:
 				attr_info = error_attr->get_attr_info(error_attr);
 				DBG1(DBG_IMC, "  unsupported attribute %#B", &attr_info);

src/libimcv/plugins/imc_test/imc_test.c

@@ -219,6 +219,7 @@ TNC_Result TNC_IMC_ReceiveMessage(TNC_IMCID imc_id,
 			ietf_attr_pa_tnc_error_t *error_attr;
 			pa_tnc_error_code_t error_code;
 			chunk_t msg_info, attr_info;
+			u_int32_t offset;
 
 			error_attr = (ietf_attr_pa_tnc_error_t*)attr;
 			error_code = error_attr->get_error_code(error_attr);
@@ -228,6 +229,10 @@ TNC_Result TNC_IMC_ReceiveMessage(TNC_IMCID imc_id,
 				 pa_tnc_error_code_names, error_code, &msg_info);
 			switch (error_code)
 			{
+				case PA_ERROR_INVALID_PARAMETER:
+					offset = error_attr->get_offset(error_attr);
+					DBG1(DBG_IMC, "  occurred at offset of %u bytes", offset);
+					break;
 				case PA_ERROR_ATTR_TYPE_NOT_SUPPORTED:
 					attr_info = error_attr->get_attr_info(error_attr);
 					DBG1(DBG_IMC, "  unsupported attribute %#B", &attr_info);

src/libimcv/plugins/imv_scanner/imv_scanner.c

@@ -228,6 +228,7 @@ TNC_Result TNC_IMV_ReceiveMessage(TNC_IMVID imv_id,
 			ietf_attr_pa_tnc_error_t *error_attr;
 			pa_tnc_error_code_t error_code;
 			chunk_t msg_info, attr_info;
+			u_int32_t offset;
 
 			error_attr = (ietf_attr_pa_tnc_error_t*)attr;
 			error_code = error_attr->get_error_code(error_attr);
@@ -237,6 +238,10 @@ TNC_Result TNC_IMV_ReceiveMessage(TNC_IMVID imv_id,
 
 			switch (error_code)
 			{
+				case PA_ERROR_INVALID_PARAMETER:
+					offset = error_attr->get_offset(error_attr);
+					DBG1(DBG_IMV, "  occurred at offset of %u bytes", offset);
+					break;
 				case PA_ERROR_ATTR_TYPE_NOT_SUPPORTED:
 					attr_info = error_attr->get_attr_info(error_attr);
 					DBG1(DBG_IMV, "  unsupported attribute %#B", &attr_info);

src/libimcv/plugins/imv_test/imv_test.c

@@ -174,6 +174,7 @@ TNC_Result TNC_IMV_ReceiveMessage(TNC_IMVID imv_id,
 			ietf_attr_pa_tnc_error_t *error_attr;
 			pa_tnc_error_code_t error_code;
 			chunk_t msg_info, attr_info;
+			u_int32_t offset;
 
 			error_attr = (ietf_attr_pa_tnc_error_t*)attr;
 			error_code = error_attr->get_error_code(error_attr);
@@ -183,6 +184,10 @@ TNC_Result TNC_IMV_ReceiveMessage(TNC_IMVID imv_id,
 				 pa_tnc_error_code_names, error_code, &msg_info);
 			switch (error_code)
 			{
+				case PA_ERROR_INVALID_PARAMETER:
+					offset = error_attr->get_offset(error_attr);
+					DBG1(DBG_IMV, "  occurred at offset of %u bytes", offset);
+					break;
 				case PA_ERROR_ATTR_TYPE_NOT_SUPPORTED:
 					attr_info = error_attr->get_attr_info(error_attr);
 					DBG1(DBG_IMV, "  unsupported attribute %#B", &attr_info);