adapted state_machine for retry batches
[strongswan.git] / src / libcharon / plugins / tnccs_20 / tnccs_20.c
index fcabc55..636f525 100644 (file)
  */
 
 #include "tnccs_20.h"
-#include "tnccs_20_types.h"
 #include "batch/pb_tnc_batch.h"
-#include "messages/pb_tnc_message.h"
-#include "messages/pb_pa_message.h"
-#include "messages/pb_error_message.h"
-#include "messages/pb_assessment_result_message.h"
-#include "messages/pb_access_recommendation_message.h"
-#include "messages/pb_reason_string_message.h"
-#include "messages/pb_language_preference_message.h"
+#include "messages/pb_tnc_msg.h"
+#include "messages/pb_pa_msg.h"
+#include "messages/pb_error_msg.h"
+#include "messages/pb_assessment_result_msg.h"
+#include "messages/pb_access_recommendation_msg.h"
+#include "messages/pb_remediation_parameters_msg.h"
+#include "messages/pb_reason_string_msg.h"
+#include "messages/pb_language_preference_msg.h"
 #include "state_machine/pb_tnc_state_machine.h"
 
 #include <debug.h>
 #include <daemon.h>
 #include <threading/mutex.h>
 #include <tnc/tncif.h>
-#include <tnc/tncifimv_names.h>
+#include <tnc/tncifimv.h>
 #include <tnc/tnccs/tnccs.h>
 
 typedef struct private_tnccs_20_t private_tnccs_20_t;
@@ -71,6 +71,11 @@ struct private_tnccs_20_t {
        mutex_t *mutex;
 
        /**
+        * Flag set while processing
+        */
+       bool fatal_error;
+
+       /**
         * Flag set by IMC/IMV RequestHandshakeRetry() function
         */
        bool request_handshake_retry;
@@ -81,21 +86,21 @@ struct private_tnccs_20_t {
        recommendations_t *recs;
 };
 
-METHOD(tnccs_t, send_message, void,
+METHOD(tnccs_t, send_msg, void,
        private_tnccs_20_t* this, TNC_IMCID imc_id, TNC_IMVID imv_id,
                                                          TNC_BufferReference msg,
                                                          TNC_UInt32 msg_len,
                                                          TNC_MessageType msg_type)
 {
-    TNC_MessageSubtype msg_sub_type;
-    TNC_VendorID msg_vendor_id;
-       pb_tnc_message_t *pb_tnc_msg;
+       TNC_MessageSubtype msg_sub_type;
+       TNC_VendorID msg_vendor_id;
+       pb_tnc_msg_t *pb_tnc_msg;
        pb_tnc_batch_type_t batch_type;
 
        msg_sub_type =   msg_type       & TNC_SUBTYPE_ANY;
        msg_vendor_id = (msg_type >> 8) & TNC_VENDORID_ANY;
 
-       pb_tnc_msg = pb_pa_message_create(msg_vendor_id, msg_sub_type, imc_id, imv_id,
+       pb_tnc_msg = pb_pa_msg_create(msg_vendor_id, msg_sub_type, imc_id, imv_id,
                                                                          chunk_create(msg, msg_len));
 
        /* adding PA message to SDATA or CDATA batch only */
@@ -107,7 +112,7 @@ METHOD(tnccs_t, send_message, void,
        }
        if (this->batch->get_type(this->batch) == batch_type)
        {
-               this->batch->add_message(this->batch, pb_tnc_msg);
+               this->batch->add_msg(this->batch, pb_tnc_msg);
        }
        else
        {
@@ -116,155 +121,189 @@ METHOD(tnccs_t, send_message, void,
        this->mutex->unlock(this->mutex);
 }
 
-static status_t handle_messages(private_tnccs_20_t *this, pb_tnc_batch_t *batch)
+/**
+ * Handle a single PB-TNC message according to its type
+ */
+static void handle_message(private_tnccs_20_t *this, pb_tnc_msg_t *msg)
 {
-       enumerator_t *enumerator;
-       pb_tnc_message_t *msg;
-
-       enumerator = batch->create_msg_enumerator(batch);
-       while (enumerator->enumerate(enumerator, &msg))
+       switch (msg->get_type(msg))
        {
-               switch (msg->get_type(msg))
+               case PB_MSG_EXPERIMENTAL:
+                       /* nothing to do */
+                       break;
+               case PB_MSG_PA:
                {
-                       case PB_MSG_EXPERIMENTAL:
-                               /* for experiments */
-                               break;
-                       case PB_MSG_PA:
-                       {
-                               pb_pa_message_t *pa_msg;
-                               TNC_MessageType msg_type;
-                               u_int32_t vendor_id, subtype;
-                               chunk_t msg_body;
+                       pb_pa_msg_t *pa_msg;
+                       TNC_MessageType msg_type;
+                       u_int32_t vendor_id, subtype;
+                       chunk_t msg_body;
 
-                               pa_msg = (pb_pa_message_t*)msg;
-                               vendor_id = pa_msg->get_vendor_id(pa_msg, &subtype);
-                               msg_type = (vendor_id << 8) | (subtype & 0xff);
-                               msg_body = pa_msg->get_body(pa_msg);
+                       pa_msg = (pb_pa_msg_t*)msg;
+                       vendor_id = pa_msg->get_vendor_id(pa_msg, &subtype);
+                       msg_type = (vendor_id << 8) | (subtype & 0xff);
+                       msg_body = pa_msg->get_body(pa_msg);
 
-                               DBG2(DBG_TNC, "handling message type 0x%08x", msg_type);
+                       DBG2(DBG_TNC, "handling PB-PA message type 0x%08x", msg_type);
 
-                               if (this->is_server)
-                               {
-                                       charon->imvs->receive_message(charon->imvs,
-                                       this->connection_id, msg_body.ptr, msg_body.len, msg_type);
-                               }
-                               else
-                               {
-                                       charon->imcs->receive_message(charon->imcs,
-                                       this->connection_id, msg_body.ptr, msg_body.len,msg_type);
-                               }
-                               break;
-                       }
-                       case PB_MSG_ASSESSMENT_RESULT:
+                       if (this->is_server)
                        {
-                               pb_assessment_result_message_t *assess_msg;
-                               u_int32_t result;
-
-                               assess_msg = (pb_assessment_result_message_t*)msg;
-                               result = assess_msg->get_assessment_result(assess_msg);
-                               DBG1(DBG_TNC, "assessment result is '%N'",
-                                                          evaluation_result_names, result);
-                               break;
+                               charon->imvs->receive_message(charon->imvs,
+                               this->connection_id, msg_body.ptr, msg_body.len, msg_type);
                        }
-                       case PB_MSG_ACCESS_RECOMMENDATION:
+                       else
                        {
-                               pb_access_recommendation_message_t *rec_msg;
-                               u_int16_t rec;
-
-                               rec_msg = (pb_access_recommendation_message_t*)msg;
-                               rec = rec_msg->get_access_recommendation(rec_msg);
-                               DBG1(DBG_TNC, "access_recommendation is '%N'",
-                                                          action_recommendation_names, rec);
-                               break;
+                               charon->imcs->receive_message(charon->imcs,
+                               this->connection_id, msg_body.ptr, msg_body.len,msg_type);
                        }
-                       case PB_MSG_REMEDIATION_PARAMETERS:
+                       break;
+               }
+               case PB_MSG_ASSESSMENT_RESULT:
+               {
+                       pb_assessment_result_msg_t *assess_msg;
+                       u_int32_t result;
+
+                       assess_msg = (pb_assessment_result_msg_t*)msg;
+                       result = assess_msg->get_assessment_result(assess_msg);
+                       DBG1(DBG_TNC, "PB-TNC assessment result is '%N'",
+                                TNC_IMV_Evaluation_Result_names, result);
+                       break;
+               }
+               case PB_MSG_ACCESS_RECOMMENDATION:
+               {
+                       pb_access_recommendation_msg_t *rec_msg;
+                       pb_access_recommendation_code_t rec;
+                       TNC_ConnectionState state = TNC_CONNECTION_STATE_ACCESS_NONE;
+
+                       rec_msg = (pb_access_recommendation_msg_t*)msg;
+                       rec = rec_msg->get_access_recommendation(rec_msg);
+                       DBG1(DBG_TNC, "PB-TNC access recommendation is '%N'",
+                                                  pb_access_recommendation_code_names, rec);
+                       switch (rec)
                        {
-                               /* TODO : Remediation parameters message processing */
-                               break;
+                               case PB_REC_ACCESS_ALLOWED:
+                                       state = TNC_CONNECTION_STATE_ACCESS_ALLOWED;
+                                       break;
+                               case PB_REC_ACCESS_DENIED:
+                                       state = TNC_CONNECTION_STATE_ACCESS_NONE;
+                                       break;
+                               case PB_REC_QUARANTINED:
+                                       state = TNC_CONNECTION_STATE_ACCESS_ISOLATED;
                        }
-                       case PB_MSG_ERROR:
-                       {
-                               pb_error_message_t *err_msg;
-                               bool fatal;
-                               u_int32_t vendor_id;
-                               u_int16_t error_code;
+                       charon->imcs->notify_connection_change(charon->imcs,
+                                                                                                  this->connection_id, state);
+                       break;
+               }
+               case PB_MSG_REMEDIATION_PARAMETERS:
+               {
+                       /* TODO : Remediation parameters message processing */
+                       break;
+               }
+               case PB_MSG_ERROR:
+               {
+                       pb_error_msg_t *err_msg;
+                       bool fatal;
+                       u_int32_t vendor_id;
+                       u_int16_t error_code;
 
-                               err_msg = (pb_error_message_t*)msg;
-                               fatal = err_msg->get_fatal_flag(err_msg);
-                               vendor_id = err_msg->get_vendor_id(err_msg);
-                               error_code = err_msg->get_error_code(err_msg);
+                       err_msg = (pb_error_msg_t*)msg;
+                       fatal = err_msg->get_fatal_flag(err_msg);
+                       vendor_id = err_msg->get_vendor_id(err_msg);
+                       error_code = err_msg->get_error_code(err_msg);
 
-                               if (vendor_id == IETF_VENDOR_ID)
-                               {
-                                       switch (error_code)
-                                       {
-                                               case PB_ERROR_INVALID_PARAMETER:
-                                               case PB_ERROR_UNSUPPORTED_MANDATORY_MESSAGE:
-                                                       DBG1(DBG_TNC, "received %s PB-TNC Error '%N' "
-                                                                                 "(offset %u bytes)",
-                                                                                 fatal ? "fatal" : "non-fatal",
-                                                                                 pb_tnc_error_code_names, error_code,
-                                                                                 err_msg->get_offset(err_msg));
-                                                       break;
-                                               case PB_ERROR_VERSION_NOT_SUPPORTED:
-                                                       DBG1(DBG_TNC, "received %s PB-TNC Error '%N' "
-                                                                                 "caused by bad version 0x%02x",
-                                                                                 fatal ? "fatal" : "non-fatal",
-                                                                                 pb_tnc_error_code_names, error_code,
-                                                                                 err_msg->get_bad_version(err_msg));
-                                                       break;
-                                               case PB_ERROR_UNEXPECTED_BATCH_TYPE:
-                                               case PB_ERROR_LOCAL_ERROR:
-                                               default:
-                                                       DBG1(DBG_TNC, "received %s PB-TNC Error '%N'",
-                                                                                 fatal ? "fatal" : "non-fatal",
-                                                                                 pb_tnc_error_code_names, error_code);
-                                                       break;
-                                       }
-                               }
-                               else
+                       if (fatal)
+                       {
+                               this->fatal_error = TRUE;
+                       }
+
+                       if (vendor_id == IETF_VENDOR_ID)
+                       {
+                               switch (error_code)
                                {
-                                       DBG1(DBG_TNC, "received %s PB-TNC Error (%u) "
-                                                                 "with Vendor ID 0x%06x",
-                                                                 fatal ? "fatal" : "non-fatal",
-                                                                 error_code, vendor_id);
+                                       case PB_ERROR_INVALID_PARAMETER:
+                                       case PB_ERROR_UNSUPPORTED_MANDATORY_MSG:
+                                               DBG1(DBG_TNC, "received %s PB-TNC error '%N' "
+                                                                         "(offset %u bytes)",
+                                                                         fatal ? "fatal" : "non-fatal",
+                                                                         pb_tnc_error_code_names, error_code,
+                                                                         err_msg->get_offset(err_msg));
+                                               break;
+                                       case PB_ERROR_VERSION_NOT_SUPPORTED:
+                                               DBG1(DBG_TNC, "received %s PB-TNC error '%N' "
+                                                                         "caused by bad version 0x%02x",
+                                                                         fatal ? "fatal" : "non-fatal",
+                                                                         pb_tnc_error_code_names, error_code,
+                                                                         err_msg->get_bad_version(err_msg));
+                                               break;
+                                       case PB_ERROR_UNEXPECTED_BATCH_TYPE:
+                                       case PB_ERROR_LOCAL_ERROR:
+                                       default:
+                                               DBG1(DBG_TNC, "received %s PB-TNC error '%N'",
+                                                                         fatal ? "fatal" : "non-fatal",
+                                                                         pb_tnc_error_code_names, error_code);
+                                               break;
                                }
-                               break;
                        }
-                       case PB_MSG_LANGUAGE_PREFERENCE:
+                       else
                        {
-                               pb_language_preference_message_t *lang_msg;
-                               chunk_t lang;
+                               DBG1(DBG_TNC, "received %s PB-TNC error (%u) "
+                                                         "with Vendor ID 0x%06x",
+                                                         fatal ? "fatal" : "non-fatal",
+                                                         error_code, vendor_id);
+                       }
+                       break;
+               }
+               case PB_MSG_LANGUAGE_PREFERENCE:
+               {
+                       pb_language_preference_msg_t *lang_msg;
+                       chunk_t lang;
 
-                               lang_msg = (pb_language_preference_message_t*)msg;
-                               lang = lang_msg->get_language_preference(lang_msg);
+                       lang_msg = (pb_language_preference_msg_t*)msg;
+                       lang = lang_msg->get_language_preference(lang_msg);
 
-                               DBG2(DBG_TNC, "setting language preference '%.*s'",
-                                                          lang.len, lang.ptr);
-                               this->recs->set_preferred_language(this->recs, lang);
-                               break;
-                       }
-                       case PB_MSG_REASON_STRING:
-                       {
-                               pb_reason_string_message_t *reason_msg;
-                               chunk_t reason_string, language_code;
-
-                               reason_msg = (pb_reason_string_message_t*)msg;
-                               reason_string = reason_msg->get_reason_string(reason_msg);
-                               language_code = reason_msg->get_language_code(reason_msg);
-                               DBG2(DBG_TNC, "reason string: '%.*s", reason_string.len,
-                                                                                                         reason_string.ptr);
-                               DBG2(DBG_TNC, "language code: '%.*s", language_code.len,
-                                                                                                         language_code.ptr);
-                               break;
-                       }
-                       default:
-                               break;
+                       DBG2(DBG_TNC, "setting language preference to '%.*s'",
+                                                  lang.len, lang.ptr);
+                       this->recs->set_preferred_language(this->recs, lang);
+                       break;
+               }
+               case PB_MSG_REASON_STRING:
+               {
+                       pb_reason_string_msg_t *reason_msg;
+                       chunk_t reason_string, language_code;
+
+                       reason_msg = (pb_reason_string_msg_t*)msg;
+                       reason_string = reason_msg->get_reason_string(reason_msg);
+                       language_code = reason_msg->get_language_code(reason_msg);
+                       DBG2(DBG_TNC, "reason string is '%.*s", reason_string.len,
+                                                                                                       reason_string.ptr);
+                       DBG2(DBG_TNC, "language code is '%.*s", language_code.len,
+                                                                                                       language_code.ptr);
+                       break;
                }
+               default:
+                       break;
        }
-       enumerator->destroy(enumerator);
+}
 
-       return SUCCESS;
+/**
+ *  Build a CRETRY or SRETRY batch
+ */
+static void build_retry_batch(private_tnccs_20_t *this)
+{
+       pb_tnc_batch_type_t batch_retry_type;
+
+       batch_retry_type = this->is_server ? PB_BATCH_SRETRY : PB_BATCH_CRETRY;
+       if (this->batch)
+       {
+               if (this->batch->get_type(this->batch) == batch_retry_type)
+               {
+                       /* retry batch has already been created */
+                       return;
+               }
+               DBG1(DBG_TNC, "cancelling PB-TNC %N batch",
+                       pb_tnc_batch_type_names, this->batch->get_type(this->batch));
+               this->batch->destroy(this->batch);
+        }
+       this->batch = pb_tnc_batch_create(this->is_server, batch_retry_type);
 }
 
 METHOD(tls_t, process, status_t,
@@ -272,14 +311,14 @@ METHOD(tls_t, process, status_t,
 {
        chunk_t data;
        pb_tnc_batch_t *batch;
-       pb_tnc_message_t *msg;
+       pb_tnc_msg_t *msg;
        enumerator_t *enumerator;
        status_t status;
 
        if (this->is_server && !this->connection_id)
        {
                this->connection_id = charon->tnccs->create_connection(charon->tnccs,
-                                                               (tnccs_t*)this, _send_message,
+                                                               (tnccs_t*)this, _send_msg,
                                                                &this->request_handshake_retry, &this->recs);
                if (!this->connection_id)
                {
@@ -287,48 +326,100 @@ METHOD(tls_t, process, status_t,
                }
                charon->imvs->notify_connection_change(charon->imvs,
                                                        this->connection_id, TNC_CONNECTION_STATE_CREATE);
+               charon->imvs->notify_connection_change(charon->imvs,
+                                                       this->connection_id, TNC_CONNECTION_STATE_HANDSHAKE);
        }
 
        data = chunk_create(buf, buflen);
-       DBG1(DBG_TNC, "received TNCCS Batch (%u bytes) for Connection ID %u",
+       DBG1(DBG_TNC, "received TNCCS batch (%u bytes) for Connection ID %u",
                                   data.len, this->connection_id);
-       DBG3(DBG_TNC, "%B", &data);  
+       DBG3(DBG_TNC, "%B", &data);
        batch = pb_tnc_batch_create_from_data(this->is_server, data);
        status = batch->process(batch, this->state_machine);
 
-       switch (status)
+       if (status != FAILED)
        {
-               case SUCCESS:
-                       handle_messages(this, batch);
-                       if (this->is_server)
+               enumerator_t *enumerator;
+               pb_tnc_msg_t *msg;
+               pb_tnc_batch_type_t batch_type;
+               bool empty = TRUE;
+
+               batch_type = batch->get_type(batch);
+
+               if (batch_type == PB_BATCH_CRETRY)
+               {
+                       /* Send an SRETRY batch in response */
+                       this->mutex->lock(this->mutex);
+                       build_retry_batch(this);
+                       this->mutex->unlock(this->mutex);
+               }
+               else if (batch_type == PB_BATCH_SRETRY)
+               {
+                       /* Restart the measurements */
+                       charon->imcs->notify_connection_change(charon->imcs,
+                       this->connection_id, TNC_CONNECTION_STATE_HANDSHAKE);
+                       charon->imcs->begin_handshake(charon->imcs, this->connection_id);
+               }
+
+               enumerator = batch->create_msg_enumerator(batch);
+               while (enumerator->enumerate(enumerator, &msg))
+               {
+                       handle_message(this, msg);
+                       empty = FALSE;
+               }
+               enumerator->destroy(enumerator);
+
+               /* received an empty CLOSE batch from PB-TNC client */
+               if (this->is_server && batch_type == PB_BATCH_CLOSE && empty)
+               {
+                       batch->destroy(batch);
+                       if (this->fatal_error)
                        {
-                               charon->imvs->batch_ending(charon->imvs, this->connection_id);
+                               DBG1(DBG_TNC, "a fatal PB-TNC error occurred, "
+                                                         "terminating connection");
+                               return FAILED;
                        }
                        else
                        {
-                               charon->imcs->batch_ending(charon->imcs, this->connection_id);
+                               return SUCCESS;
                        }
-                       break;
+               }
+
+               if (this->is_server)
+               {
+                       charon->imvs->batch_ending(charon->imvs, this->connection_id);
+               }
+               else
+               {
+                       charon->imcs->batch_ending(charon->imcs, this->connection_id);
+               }
+       }
+
+       switch (status)
+       {
                case FAILED:
+                       this->fatal_error = TRUE;
                        this->mutex->lock(this->mutex);
                        if (this->batch)
                        {
-                               DBG1(DBG_TNC, "cancelling PB-TNC %N Batch",
+                               DBG1(DBG_TNC, "cancelling PB-TNC %N batch",
                                        pb_tnc_batch_type_names, this->batch->get_type(this->batch));
                                this->batch->destroy(this->batch);
                         }
                        this->batch = pb_tnc_batch_create(this->is_server, PB_BATCH_CLOSE);
                        this->mutex->unlock(this->mutex);
-                       /* fall through */
+                       /* fall through to add error messages to outbound batch */
                case VERIFY_ERROR:
                        enumerator = batch->create_error_enumerator(batch);
                        while (enumerator->enumerate(enumerator, &msg))
                        {
                                this->mutex->lock(this->mutex);
-                               this->batch->add_message(this->batch, msg->get_ref(msg));
+                               this->batch->add_msg(this->batch, msg->get_ref(msg));
                                this->mutex->unlock(this->mutex);
                        }
                        enumerator->destroy(enumerator);
+                       break;
+               case SUCCESS:
                default:
                        break;
        }
@@ -337,29 +428,73 @@ METHOD(tls_t, process, status_t,
        return NEED_MORE;
 }
 
+/**
+ *  Build a RESULT batch if a final recommendation is available
+ */
+static void check_and_build_recommendation(private_tnccs_20_t *this)
+{
+       TNC_IMV_Action_Recommendation rec;
+       TNC_IMV_Evaluation_Result eval;
+       TNC_IMVID id;
+       chunk_t reason, language;
+       enumerator_t *enumerator;
+       pb_tnc_msg_t *msg;
+
+       if (!this->recs->have_recommendation(this->recs, &rec, &eval))
+       {
+               charon->imvs->solicit_recommendation(charon->imvs, this->connection_id);
+       }
+       if (this->recs->have_recommendation(this->recs, &rec, &eval))
+       {
+               this->batch = pb_tnc_batch_create(this->is_server, PB_BATCH_RESULT);
+
+               msg = pb_assessment_result_msg_create(eval);
+               this->batch->add_msg(this->batch, msg);
+
+               /**
+                * IMV Action Recommendation and PB Access Recommendation codes
+                * are shifted by one.
+                */
+               msg = pb_access_recommendation_msg_create(rec + 1);
+               this->batch->add_msg(this->batch, msg);
+
+               enumerator = this->recs->create_reason_enumerator(this->recs);
+               while (enumerator->enumerate(enumerator, &id, &reason, &language))
+               {
+                       msg = pb_reason_string_msg_create(reason, language);
+                       this->batch->add_msg(this->batch, msg);
+               }
+               enumerator->destroy(enumerator);
+       }
+}
+
 METHOD(tls_t, build, status_t,
        private_tnccs_20_t *this, void *buf, size_t *buflen, size_t *msglen)
 {
+       status_t status;
+       pb_tnc_state_t state;
+
+       /* Initialize the connection */
        if (!this->is_server && !this->connection_id)
        {
-               pb_tnc_message_t *msg;
+               pb_tnc_msg_t *msg;
                char *pref_lang;
 
                this->connection_id = charon->tnccs->create_connection(charon->tnccs,
-                                                                               (tnccs_t*)this, _send_message,
+                                                                               (tnccs_t*)this, _send_msg,
                                                                                &this->request_handshake_retry, NULL);
                if (!this->connection_id)
                {
                        return FAILED;
                }
 
-               /* Create PB-TNC Language Preference Message */
+               /* Create PB-TNC Language Preference message */
                pref_lang = charon->imcs->get_preferred_language(charon->imcs);
-               msg = pb_language_preference_message_create(chunk_create(pref_lang,
+               msg = pb_language_preference_msg_create(chunk_create(pref_lang,
                                                                                                        strlen(pref_lang)));
                this->mutex->lock(this->mutex);
                this->batch = pb_tnc_batch_create(this->is_server, PB_BATCH_CDATA);
-               this->batch->add_message(this->batch, msg);
+               this->batch->add_msg(this->batch, msg);
                this->mutex->unlock(this->mutex);
 
                charon->imcs->notify_connection_change(charon->imcs,
@@ -369,47 +504,97 @@ METHOD(tls_t, build, status_t,
                charon->imcs->begin_handshake(charon->imcs, this->connection_id);
        }
 
+       state = this->state_machine->get_state(this->state_machine);
+
+       if (this->is_server && this->fatal_error && state == PB_STATE_END)
+       {
+               DBG1(DBG_TNC, "a fatal PB-TNC error occurred, terminating connection");
+               return FAILED;
+       }
+
+       /* Do not allow any asynchronous IMCs or IMVs to add additional messages */
+       this->mutex->lock(this->mutex);
+
+       if (this->request_handshake_retry)
+       {
+               if (state != PB_STATE_INIT)
+               {
+                       build_retry_batch(this);
+               }
+
+               /* Reset the flag for the next handshake retry request */
+               this->request_handshake_retry = FALSE;
+       }
+
+       if (!this->batch)
+       {
+               if (this->is_server)
+               {
+                       if (state == PB_STATE_SERVER_WORKING)
+                       {
+                               check_and_build_recommendation(this);
+                       }
+               }
+               else
+               {
+                       /**
+                        * if the DECIDED state has been reached and no CRETRY is under way
+                        * or if a CLOSE batch with error messages has been received,
+                        * a PB-TNC client replies with an empty CLOSE batch.
+                        */
+                       if (state == PB_STATE_DECIDED || state == PB_STATE_END)
+                       {
+                               this->batch = pb_tnc_batch_create(this->is_server, PB_BATCH_CLOSE);
+                       }
+               }
+       }
+
        if (this->batch)
        {
                pb_tnc_batch_type_t batch_type;
-               status_t status;
-               chunk_t data;
+               chunk_t data;
 
-               this->mutex->lock(this->mutex);
                batch_type = this->batch->get_type(this->batch);
 
                if (this->state_machine->send_batch(this->state_machine, batch_type))
                {
                        this->batch->build(this->batch);
                        data = this->batch->get_encoding(this->batch);
-                       DBG1(DBG_TNC, "sending PB-TNC %N Batch (%d bytes) for Connection ID %u",
+                       DBG1(DBG_TNC, "sending PB-TNC %N batch (%d bytes) for Connection ID %u",
                                                   pb_tnc_batch_type_names, batch_type, data.len,
                                                   this->connection_id);
                        DBG3(DBG_TNC, "%B", &data);
-
                        *msglen = data.len;
-                       *buflen = data.len;
-                       memcpy(buf, data.ptr, data.len);
+
+                       if (data.len > *buflen)
+                       {
+                               DBG1(DBG_TNC, "fragmentation of PB-TNC batch not supported yet");
+                       }
+                       else
+                       {
+                               *buflen = data.len;
+                       }
+                       memcpy(buf, data.ptr, *buflen);
                        status = ALREADY_DONE;
                }
                else
                {
-                       DBG1(DBG_TNC, "cancelling unexpected PB-TNC Batch Type: %N",
+                       DBG1(DBG_TNC, "cancelling unexpected PB-TNC batch type: %N",
                                 pb_tnc_batch_type_names, batch_type);
                        status = INVALID_STATE;
                }
 
                this->batch->destroy(this->batch);
                this->batch = NULL;
-               this->mutex->unlock(this->mutex);
-
-               return status;
        }
        else
        {
-               DBG1(DBG_TNC, "no TNCCS Batch to send");
-               return INVALID_STATE;
+               DBG1(DBG_TNC, "no PB-TNC batch to send");
+               status = INVALID_STATE;
        }
+       this->mutex->unlock(this->mutex);
+
+       return status;
 }
 
 METHOD(tls_t, is_server, bool,
@@ -432,10 +617,7 @@ METHOD(tls_t, is_complete, bool,
 
        if (this->recs && this->recs->have_recommendation(this->recs, &rec, &eval))
        {
-               DBG2(DBG_TNC, "Final recommendation '%N' and evaluation '%N'",
-                        action_recommendation_names, rec, evaluation_result_names, eval);
-
-               return charon->imvs->enforce_recommendation(charon->imvs, rec);
+               return charon->imvs->enforce_recommendation(charon->imvs, rec, eval);
        }
        else
        {
@@ -452,7 +634,8 @@ METHOD(tls_t, get_eap_msk, chunk_t,
 METHOD(tls_t, destroy, void,
        private_tnccs_20_t *this)
 {
-       charon->tnccs->remove_connection(charon->tnccs, this->connection_id);
+       charon->tnccs->remove_connection(charon->tnccs, this->connection_id,
+                                                                                                       this->is_server);
        this->state_machine->destroy(this->state_machine);
        this->mutex->destroy(this->mutex);
        DESTROY_IF(this->batch);