Imported Debian patch 1.1.1+rev1207-1debian/1.1.1+rev1207-1

1 files changed, 1296 insertions, 0 deletions

diff --git a/lib/libdvben50221/en50221_transport.c b/lib/libdvben50221/en50221_transport.c
new file mode 100644
index 0000000..f6f46db
--- /dev/null
+++ b/lib/libdvben50221/en50221_transport.c
@@ -0,0 +1,1296 @@
+/*
+    en50221 encoder An implementation for libdvb
+    an implementation for the en50221 transport layer
+
+    Copyright (C) 2004, 2005 Manu Abraham <abraham.manu@gmail.com>
+    Copyright (C) 2005 Julian Scheel (julian at jusst dot de)
+    Copyright (C) 2006 Andrew de Quincey (adq_dvb@lidskialf.net)
+
+    This library is free software; you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as
+    published by the Free Software Foundation; either version 2.1 of
+    the License, or (at your option) any later version.
+
+    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 Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+*/
+
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <pthread.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/poll.h>
+#include <time.h>
+#include <libdvbmisc/dvbmisc.h>
+#include <libdvbapi/dvbca.h>
+#include "en50221_errno.h"
+#include "en50221_transport.h"
+#include "asn_1.h"
+
+// these are the Transport Tags, like
+// described in EN50221, Annex A.4.1.13 (pg70)
+#define T_SB                0x80	// sb                           primitive   h<--m
+#define T_RCV               0x81	// receive                      primitive   h-->m
+#define T_CREATE_T_C        0x82	// create transport connection  primitive   h-->m
+#define T_C_T_C_REPLY       0x83	// ctc reply                    primitive   h<--m
+#define T_DELETE_T_C        0x84	// delete tc                    primitive   h<->m
+#define T_D_T_C_REPLY       0x85	// dtc reply                    primitive   h<->m
+#define T_REQUEST_T_C       0x86	// request transport connection primitive   h<--m
+#define T_NEW_T_C           0x87	// new tc / reply to t_request  primitive   h-->m
+#define T_T_C_ERROR         0x77	// error creating tc            primitive   h-->m
+#define T_DATA_LAST         0xA0	// convey data from higher      constructed h<->m
+				 // layers
+#define T_DATA_MORE         0xA1	// convey data from higher      constructed h<->m
+				 // layers
+
+struct en50221_message {
+	struct en50221_message *next;
+	uint32_t length;
+	uint8_t data[0];
+};
+
+struct en50221_connection {
+	uint32_t state;		// the current state: idle/in_delete/in_create/active
+	struct timeval tx_time;	// time last request was sent from host->module, or 0 if ok
+	struct timeval last_poll_time;	// time of last poll transmission
+	uint8_t *chain_buffer;	// used to save parts of chained packets
+	uint32_t buffer_length;
+
+	struct en50221_message *send_queue;
+	struct en50221_message *send_queue_tail;
+};
+
+struct en50221_slot {
+	int ca_hndl;
+	uint8_t slot;		// CAM slot
+	struct en50221_connection *connections;
+
+	pthread_mutex_t slot_lock;
+
+	uint32_t response_timeout;
+	uint32_t poll_delay;
+};
+
+struct en50221_transport_layer {
+	uint8_t max_slots;
+	uint8_t max_connections_per_slot;
+	struct en50221_slot *slots;
+	struct pollfd *slot_pollfds;
+	int slots_changed;
+
+	pthread_mutex_t global_lock;
+	pthread_mutex_t setcallback_lock;
+
+	int error;
+	int error_slot;
+
+	en50221_tl_callback callback;
+	void *callback_arg;
+};
+
+static int en50221_tl_process_data(struct en50221_transport_layer *tl,
+				   uint8_t slot_id, uint8_t * data,
+				   uint32_t data_length);
+static int en50221_tl_poll_tc(struct en50221_transport_layer *tl,
+			      uint8_t slot_id, uint8_t connection_id);
+static int en50221_tl_alloc_new_tc(struct en50221_transport_layer *tl,
+				   uint8_t slot_id);
+static void queue_message(struct en50221_transport_layer *tl,
+			  uint8_t slot_id, uint8_t connection_id,
+			  struct en50221_message *msg);
+static int en50221_tl_handle_create_tc_reply(struct en50221_transport_layer
+					     *tl, uint8_t slot_id,
+					     uint8_t connection_id);
+static int en50221_tl_handle_delete_tc(struct en50221_transport_layer *tl,
+				       uint8_t slot_id,
+				       uint8_t connection_id);
+static int en50221_tl_handle_delete_tc_reply(struct en50221_transport_layer
+					     *tl, uint8_t slot_id,
+					     uint8_t connection_id);
+static int en50221_tl_handle_request_tc(struct en50221_transport_layer *tl,
+					uint8_t slot_id,
+					uint8_t connection_id);
+static int en50221_tl_handle_data_more(struct en50221_transport_layer *tl,
+				       uint8_t slot_id,
+				       uint8_t connection_id,
+				       uint8_t * data,
+				       uint32_t data_length);
+static int en50221_tl_handle_data_last(struct en50221_transport_layer *tl,
+				       uint8_t slot_id,
+				       uint8_t connection_id,
+				       uint8_t * data,
+				       uint32_t data_length);
+static int en50221_tl_handle_sb(struct en50221_transport_layer *tl,
+				uint8_t slot_id, uint8_t connection_id,
+				uint8_t * data, uint32_t data_length);
+
+
+struct en50221_transport_layer *en50221_tl_create(uint8_t max_slots,
+						  uint8_t
+						  max_connections_per_slot)
+{
+	struct en50221_transport_layer *tl = NULL;
+	int i;
+	int j;
+
+	// setup structure
+	tl = (struct en50221_transport_layer *)
+		malloc(sizeof(struct en50221_transport_layer));
+	if (tl == NULL)
+		goto error_exit;
+	tl->max_slots = max_slots;
+	tl->max_connections_per_slot = max_connections_per_slot;
+	tl->slots = NULL;
+	tl->slot_pollfds = NULL;
+	tl->slots_changed = 1;
+	tl->callback = NULL;
+	tl->callback_arg = NULL;
+	tl->error_slot = 0;
+	tl->error = 0;
+	pthread_mutex_init(&tl->global_lock, NULL);
+	pthread_mutex_init(&tl->setcallback_lock, NULL);
+
+	// create the slots
+	tl->slots = malloc(sizeof(struct en50221_slot) * max_slots);
+	if (tl->slots == NULL)
+		goto error_exit;
+
+	// set them up
+	for (i = 0; i < max_slots; i++) {
+		tl->slots[i].ca_hndl = -1;
+
+		// create the connections for this slot
+		tl->slots[i].connections =
+		    malloc(sizeof(struct en50221_connection) * max_connections_per_slot);
+		if (tl->slots[i].connections == NULL)
+			goto error_exit;
+
+		// create a mutex for the slot
+		pthread_mutex_init(&tl->slots[i].slot_lock, NULL);
+
+		// set them up
+		for (j = 0; j < max_connections_per_slot; j++) {
+			tl->slots[i].connections[j].state = T_STATE_IDLE;
+			tl->slots[i].connections[j].tx_time.tv_sec = 0;
+			tl->slots[i].connections[j].last_poll_time.tv_sec = 0;
+			tl->slots[i].connections[j].last_poll_time.tv_usec = 0;
+			tl->slots[i].connections[j].chain_buffer = NULL;
+			tl->slots[i].connections[j].buffer_length = 0;
+			tl->slots[i].connections[j].send_queue = NULL;
+			tl->slots[i].connections[j].send_queue_tail = NULL;
+		}
+	}
+
+	// create the pollfds
+	tl->slot_pollfds = malloc(sizeof(struct pollfd) * max_slots);
+	if (tl->slot_pollfds == NULL) {
+		goto error_exit;
+	}
+	memset(tl->slot_pollfds, 0, sizeof(struct pollfd) * max_slots);
+
+	return tl;
+
+      error_exit:
+	en50221_tl_destroy(tl);
+	return NULL;
+}
+
+// Destroy an instance of the transport layer
+void en50221_tl_destroy(struct en50221_transport_layer *tl)
+{
+	int i, j;
+
+	if (tl) {
+		if (tl->slots) {
+			for (i = 0; i < tl->max_slots; i++) {
+				if (tl->slots[i].connections) {
+					for (j = 0; j < tl->max_connections_per_slot; j++) {
+						if (tl->slots[i].connections[j].chain_buffer) {
+							free(tl->slots[i].connections[j].chain_buffer);
+						}
+
+						struct en50221_message *cur_msg =
+							tl->slots[i].connections[j].send_queue;
+						while (cur_msg) {
+							struct en50221_message *next_msg = cur_msg->next;
+							free(cur_msg);
+							cur_msg = next_msg;
+						}
+						tl->slots[i].connections[j].send_queue = NULL;
+						tl->slots[i].connections[j].send_queue_tail = NULL;
+					}
+					free(tl->slots[i].connections);
+					pthread_mutex_destroy(&tl->slots[i].slot_lock);
+				}
+			}
+			free(tl->slots);
+		}
+		if (tl->slot_pollfds) {
+			free(tl->slot_pollfds);
+		}
+		pthread_mutex_destroy(&tl->setcallback_lock);
+		pthread_mutex_destroy(&tl->global_lock);
+		free(tl);
+	}
+}
+
+// this can be called from the user-space app to
+// register new slots that we should work with
+int en50221_tl_register_slot(struct en50221_transport_layer *tl,
+			     int ca_hndl, uint8_t slot,
+			     uint32_t response_timeout,
+			     uint32_t poll_delay)
+{
+	// lock
+	pthread_mutex_lock(&tl->global_lock);
+
+	// we browse through the array of slots
+	// to look for the first unused one
+	int i;
+	int16_t slot_id = -1;
+	for (i = 0; i < tl->max_slots; i++) {
+		if (tl->slots[i].ca_hndl == -1) {
+			slot_id = i;
+			break;
+		}
+	}
+	if (slot_id == -1) {
+		tl->error = EN50221ERR_OUTOFSLOTS;
+		pthread_mutex_unlock(&tl->global_lock);
+		return -1;
+	}
+	// set up the slot struct
+	pthread_mutex_lock(&tl->slots[slot_id].slot_lock);
+	tl->slots[slot_id].ca_hndl = ca_hndl;
+	tl->slots[slot_id].slot = slot;
+	tl->slots[slot_id].response_timeout = response_timeout;
+	tl->slots[slot_id].poll_delay = poll_delay;
+	pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+
+	tl->slots_changed = 1;
+	pthread_mutex_unlock(&tl->global_lock);
+	return slot_id;
+}
+
+void en50221_tl_destroy_slot(struct en50221_transport_layer *tl,
+			     uint8_t slot_id)
+{
+	int i;
+
+	if (slot_id >= tl->max_slots)
+		return;
+
+	// lock
+	pthread_mutex_lock(&tl->global_lock);
+
+	// clear the slot
+	pthread_mutex_lock(&tl->slots[slot_id].slot_lock);
+	tl->slots[slot_id].ca_hndl = -1;
+	for (i = 0; i < tl->max_connections_per_slot; i++) {
+		tl->slots[slot_id].connections[i].state = T_STATE_IDLE;
+		tl->slots[slot_id].connections[i].tx_time.tv_sec = 0;
+		tl->slots[slot_id].connections[i].last_poll_time.tv_sec = 0;
+		tl->slots[slot_id].connections[i].last_poll_time.tv_usec = 0;
+		if (tl->slots[slot_id].connections[i].chain_buffer) {
+			free(tl->slots[slot_id].connections[i].
+			     chain_buffer);
+		}
+		tl->slots[slot_id].connections[i].chain_buffer = NULL;
+		tl->slots[slot_id].connections[i].buffer_length = 0;
+
+		struct en50221_message *cur_msg =
+		    tl->slots[slot_id].connections[i].send_queue;
+		while (cur_msg) {
+			struct en50221_message *next_msg = cur_msg->next;
+			free(cur_msg);
+			cur_msg = next_msg;
+		}
+		tl->slots[slot_id].connections[i].send_queue = NULL;
+		tl->slots[slot_id].connections[i].send_queue_tail = NULL;
+	}
+	pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+
+	// tell upper layers
+	pthread_mutex_lock(&tl->setcallback_lock);
+	en50221_tl_callback cb = tl->callback;
+	void *cb_arg = tl->callback_arg;
+	pthread_mutex_unlock(&tl->setcallback_lock);
+	if (cb)
+		cb(cb_arg, T_CALLBACK_REASON_SLOTCLOSE, NULL, 0, slot_id, 0);
+
+	tl->slots_changed = 1;
+	pthread_mutex_unlock(&tl->global_lock);
+}
+
+int en50221_tl_poll(struct en50221_transport_layer *tl)
+{
+	uint8_t data[4096];
+	int slot_id;
+	int j;
+
+	// make up pollfds if the slots have changed
+	pthread_mutex_lock(&tl->global_lock);
+	if (tl->slots_changed) {
+		for (slot_id = 0; slot_id < tl->max_slots; slot_id++) {
+			if (tl->slots[slot_id].ca_hndl != -1) {
+				tl->slot_pollfds[slot_id].fd = tl->slots[slot_id].ca_hndl;
+				tl->slot_pollfds[slot_id].events = POLLIN | POLLPRI | POLLERR;
+				tl->slot_pollfds[slot_id].revents = 0;
+			} else {
+				tl->slot_pollfds[slot_id].fd = 0;
+				tl->slot_pollfds[slot_id].events = 0;
+				tl->slot_pollfds[slot_id].revents = 0;
+			}
+		}
+		tl->slots_changed = 0;
+	}
+	pthread_mutex_unlock(&tl->global_lock);
+
+	// anything happened?
+	if (poll(tl->slot_pollfds, tl->max_slots, 10) < 0) {
+		tl->error_slot = -1;
+		tl->error = EN50221ERR_CAREAD;
+		return -1;
+	}
+	// go through all slots (even though poll may not have reported any events
+	for (slot_id = 0; slot_id < tl->max_slots; slot_id++) {
+
+		// check if this slot is still used and get its handle
+		pthread_mutex_lock(&tl->slots[slot_id].slot_lock);
+		if (tl->slots[slot_id].ca_hndl == -1) {
+			pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+			continue;
+		}
+		int ca_hndl = tl->slots[slot_id].ca_hndl;
+
+		if (tl->slot_pollfds[slot_id].revents & (POLLPRI | POLLIN)) {
+			// read data
+			uint8_t r_slot_id;
+			uint8_t connection_id;
+			int readcnt = dvbca_link_read(ca_hndl, &r_slot_id,
+						      &connection_id,
+						      data, sizeof(data));
+			if (readcnt < 0) {
+				tl->error_slot = slot_id;
+				tl->error = EN50221ERR_CAREAD;
+				pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+				return -1;
+			}
+			// process it if we got some
+			if (readcnt > 0) {
+				if (tl->slots[slot_id].slot != r_slot_id) {
+					// this message is for an other CAM of the same CA
+					int new_slot_id;
+					for (new_slot_id = 0; new_slot_id < tl->max_slots; new_slot_id++) {
+						if ((tl->slots[new_slot_id].ca_hndl == ca_hndl) &&
+						    (tl->slots[new_slot_id].slot == r_slot_id))
+							break;
+					}
+					if (new_slot_id != tl->max_slots) {
+						// we found the requested CAM
+						pthread_mutex_lock(&tl->slots[new_slot_id].slot_lock);
+						if (en50221_tl_process_data(tl, new_slot_id, data, readcnt)) {
+							pthread_mutex_unlock(&tl->slots[new_slot_id].slot_lock);
+							pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+							return -1;
+						}
+						pthread_mutex_unlock(&tl->slots[new_slot_id].slot_lock);
+					} else {
+						tl->error = EN50221ERR_BADSLOTID;
+						pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+						return -1;
+					}
+				} else
+				    if (en50221_tl_process_data(tl, slot_id, data, readcnt)) {
+					pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+					return -1;
+				}
+			}
+		} else if (tl->slot_pollfds[slot_id].revents & POLLERR) {
+			// an error was reported
+			tl->error_slot = slot_id;
+			tl->error = EN50221ERR_CAREAD;
+			pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+			return -1;
+		}
+		// poll the connections on this slot + check for timeouts
+		for (j = 0; j < tl->max_connections_per_slot; j++) {
+			// ignore connection if idle
+			if (tl->slots[slot_id].connections[j].state == T_STATE_IDLE) {
+				continue;
+			}
+			// send queued data
+			if (tl->slots[slot_id].connections[j].state &
+				(T_STATE_IN_CREATION | T_STATE_ACTIVE | T_STATE_ACTIVE_DELETEQUEUED)) {
+				// send data if there is some to go and we're not waiting for a response already
+				if (tl->slots[slot_id].connections[j].send_queue &&
+				    (tl->slots[slot_id].connections[j].tx_time.tv_sec == 0)) {
+
+					// get the message
+					struct en50221_message *msg =
+						tl->slots[slot_id].connections[j].send_queue;
+					if (msg->next != NULL) {
+						tl->slots[slot_id].connections[j].send_queue = msg->next;
+					} else {
+						tl->slots[slot_id].connections[j].send_queue = NULL;
+						tl->slots[slot_id].connections[j].send_queue_tail = NULL;
+					}
+
+					// send the message
+					if (dvbca_link_write(tl->slots[slot_id].ca_hndl,
+					    		     tl->slots[slot_id].slot,
+							     j,
+							     msg->data, msg->length) < 0) {
+						free(msg);
+						pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+						tl->error_slot = slot_id;
+						tl->error = EN50221ERR_CAWRITE;
+						print(LOG_LEVEL, ERROR, 1, "CAWrite failed");
+						return -1;
+					}
+					gettimeofday(&tl->slots[slot_id].connections[j].tx_time, 0);
+
+					// fixup connection state for T_DELETE_T_C
+					if (msg->length && (msg->data[0] == T_DELETE_T_C)) {
+						tl->slots[slot_id].connections[j].state = T_STATE_IN_DELETION;
+						if (tl->slots[slot_id].connections[j].chain_buffer) {
+							free(tl->slots[slot_id].connections[j].chain_buffer);
+						}
+						tl->slots[slot_id].connections[j].chain_buffer = NULL;
+						tl->slots[slot_id].connections[j].buffer_length = 0;
+					}
+
+					free(msg);
+				}
+			}
+			// poll it if we're not expecting a reponse and the poll time has elapsed
+			if (tl->slots[slot_id].connections[j].state & T_STATE_ACTIVE) {
+				if ((tl->slots[slot_id].connections[j].tx_time.tv_sec == 0) &&
+				    (time_after(tl->slots[slot_id].connections[j].last_poll_time,
+				     		tl->slots[slot_id].poll_delay))) {
+
+					gettimeofday(&tl->slots[slot_id].connections[j].last_poll_time, 0);
+					if (en50221_tl_poll_tc(tl, slot_id, j)) {
+						pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+						return -1;
+					}
+				}
+			}
+
+			// check for timeouts - in any state
+			if (tl->slots[slot_id].connections[j].tx_time.tv_sec &&
+			    (time_after(tl->slots[slot_id].connections[j].tx_time,
+			     		tl->slots[slot_id].response_timeout))) {
+
+				if (tl->slots[slot_id].connections[j].state &
+				    (T_STATE_IN_CREATION |T_STATE_IN_DELETION)) {
+					tl->slots[slot_id].connections[j].state = T_STATE_IDLE;
+				} else if (tl->slots[slot_id].connections[j].state &
+					   (T_STATE_ACTIVE | T_STATE_ACTIVE_DELETEQUEUED)) {
+					tl->error_slot = slot_id;
+					tl->error = EN50221ERR_TIMEOUT;
+					pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+					return -1;
+				}
+			}
+		}
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+	}
+
+	return 0;
+}
+
+void en50221_tl_register_callback(struct en50221_transport_layer *tl,
+				  en50221_tl_callback callback, void *arg)
+{
+	pthread_mutex_lock(&tl->setcallback_lock);
+	tl->callback = callback;
+	tl->callback_arg = arg;
+	pthread_mutex_unlock(&tl->setcallback_lock);
+}
+
+int en50221_tl_get_error_slot(struct en50221_transport_layer *tl)
+{
+	return tl->error_slot;
+}
+
+int en50221_tl_get_error(struct en50221_transport_layer *tl)
+{
+	return tl->error;
+}
+
+int en50221_tl_send_data(struct en50221_transport_layer *tl,
+			 uint8_t slot_id, uint8_t connection_id,
+			 uint8_t * data, uint32_t data_size)
+{
+#ifdef DEBUG_TXDATA
+	printf("[[[[[[[[[[[[[[[[[[[[\n");
+	uint32_t ii = 0;
+	for (ii = 0; ii < data_size; ii++) {
+		printf("%02x: %02x\n", ii, data[ii]);
+	}
+	printf("]]]]]]]]]]]]]]]]]]]]\n");
+#endif
+
+	if (slot_id >= tl->max_slots) {
+		tl->error = EN50221ERR_BADSLOTID;
+		return -1;
+	}
+
+	pthread_mutex_lock(&tl->slots[slot_id].slot_lock);
+	if (tl->slots[slot_id].ca_hndl == -1) {
+		tl->error = EN50221ERR_BADSLOTID;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	if (connection_id >= tl->max_connections_per_slot) {
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_BADCONNECTIONID;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	if (tl->slots[slot_id].connections[connection_id].state != T_STATE_ACTIVE) {
+		tl->error = EN50221ERR_BADCONNECTIONID;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	// allocate msg structure
+	struct en50221_message *msg =
+	    malloc(sizeof(struct en50221_message) + data_size + 10);
+	if (msg == NULL) {
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_OUTOFMEMORY;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	// make up data to send
+	int length_field_len;
+	msg->data[0] = T_DATA_LAST;
+	if ((length_field_len = asn_1_encode(data_size + 1, msg->data + 1, 3)) < 0) {
+		free(msg);
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_ASNENCODE;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	msg->data[1 + length_field_len] = connection_id;
+	memcpy(msg->data + 1 + length_field_len + 1, data, data_size);
+	msg->length = 1 + length_field_len + 1 + data_size;
+
+	// queue it for transmission
+	queue_message(tl, slot_id, connection_id, msg);
+
+	pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+	return 0;
+}
+
+int en50221_tl_send_datav(struct en50221_transport_layer *tl,
+			  uint8_t slot_id, uint8_t connection_id,
+			  struct iovec *vector, int iov_count)
+{
+#ifdef DEBUG_TXDATA
+	printf("[[[[[[[[[[[[[[[[[[[[\n");
+	uint32_t ii = 0;
+	uint32_t iipos = 0;
+	for (ii = 0; ii < (uint32_t) iov_count; ii++) {
+		uint32_t jj;
+		for (jj = 0; jj < vector[ii].iov_len; jj++) {
+			printf("%02x: %02x\n", jj + iipos,
+			       *((uint8_t *) (vector[ii].iov_base) + jj));
+		}
+		iipos += vector[ii].iov_len;
+	}
+	printf("]]]]]]]]]]]]]]]]]]]]\n");
+#endif
+
+	if (slot_id >= tl->max_slots) {
+		tl->error = EN50221ERR_BADSLOTID;
+		return -1;
+	}
+
+	pthread_mutex_lock(&tl->slots[slot_id].slot_lock);
+	if (tl->slots[slot_id].ca_hndl == -1) {
+		tl->error = EN50221ERR_BADSLOTID;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	if (connection_id >= tl->max_connections_per_slot) {
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_BADCONNECTIONID;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	if (tl->slots[slot_id].connections[connection_id].state != T_STATE_ACTIVE) {
+		tl->error = EN50221ERR_BADCONNECTIONID;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	// calculate the total length of the data to send
+	uint32_t data_size = 0;
+	int i;
+	for (i = 0; i < iov_count; i++) {
+		data_size += vector[i].iov_len;
+	}
+
+	// allocate msg structure
+	struct en50221_message *msg =
+	    malloc(sizeof(struct en50221_message) + data_size + 10);
+	if (msg == NULL) {
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_OUTOFMEMORY;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	// make up data to send
+	int length_field_len;
+	msg->data[0] = T_DATA_LAST;
+	if ((length_field_len = asn_1_encode(data_size + 1, msg->data + 1, 3)) < 0) {
+		free(msg);
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_ASNENCODE;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	msg->data[1 + length_field_len] = connection_id;
+	msg->length = 1 + length_field_len + 1 + data_size;
+	msg->next = NULL;
+
+	// merge the iovecs
+	uint32_t pos = 1 + length_field_len + 1;
+	for (i = 0; i < iov_count; i++) {
+		memcpy(msg->data + pos, vector[i].iov_base,
+		       vector[i].iov_len);
+		pos += vector[i].iov_len;
+	}
+
+	// queue it for transmission
+	queue_message(tl, slot_id, connection_id, msg);
+
+	pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+	return 0;
+}
+
+int en50221_tl_new_tc(struct en50221_transport_layer *tl, uint8_t slot_id)
+{
+	// check
+	if (slot_id >= tl->max_slots) {
+		tl->error = EN50221ERR_BADSLOTID;
+		return -1;
+	}
+
+	pthread_mutex_lock(&tl->slots[slot_id].slot_lock);
+	if (tl->slots[slot_id].ca_hndl == -1) {
+		tl->error = EN50221ERR_BADSLOTID;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	// allocate a new connection if possible
+	int conid = en50221_tl_alloc_new_tc(tl, slot_id);
+	if (conid == -1) {
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_OUTOFCONNECTIONS;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	// allocate msg structure
+	struct en50221_message *msg =
+	    malloc(sizeof(struct en50221_message) + 3);
+	if (msg == NULL) {
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_OUTOFMEMORY;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	// make up the data to send
+	msg->data[0] = T_CREATE_T_C;
+	msg->data[1] = 1;
+	msg->data[2] = conid;
+	msg->length = 3;
+	msg->next = NULL;
+
+	// queue it for transmission
+	queue_message(tl, slot_id, conid, msg);
+
+	// done
+	pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+	return conid;
+}
+
+int en50221_tl_del_tc(struct en50221_transport_layer *tl, uint8_t slot_id,
+		      uint8_t connection_id)
+{
+	// check
+	if (slot_id >= tl->max_slots) {
+		tl->error = EN50221ERR_BADSLOTID;
+		return -1;
+	}
+
+	pthread_mutex_lock(&tl->slots[slot_id].slot_lock);
+	if (tl->slots[slot_id].ca_hndl == -1) {
+		tl->error = EN50221ERR_BADSLOTID;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	if (connection_id >= tl->max_connections_per_slot) {
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_BADCONNECTIONID;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	if (!(tl->slots[slot_id].connections[connection_id].state &
+	      (T_STATE_ACTIVE | T_STATE_IN_DELETION))) {
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_BADSTATE;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	// allocate msg structure
+	struct en50221_message *msg =
+	    malloc(sizeof(struct en50221_message) + 3);
+	if (msg == NULL) {
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_OUTOFMEMORY;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	// make up the data to send
+	msg->data[0] = T_DELETE_T_C;
+	msg->data[1] = 1;
+	msg->data[2] = connection_id;
+	msg->length = 3;
+	msg->next = NULL;
+
+	// queue it for transmission
+	queue_message(tl, slot_id, connection_id, msg);
+	tl->slots[slot_id].connections[connection_id].state =
+	    T_STATE_ACTIVE_DELETEQUEUED;
+
+	pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+	return 0;
+}
+
+int en50221_tl_get_connection_state(struct en50221_transport_layer *tl,
+				    uint8_t slot_id, uint8_t connection_id)
+{
+	if (slot_id >= tl->max_slots) {
+		tl->error = EN50221ERR_BADSLOTID;
+		return -1;
+	}
+
+	pthread_mutex_lock(&tl->slots[slot_id].slot_lock);
+	if (tl->slots[slot_id].ca_hndl == -1) {
+		tl->error = EN50221ERR_BADSLOTID;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	if (connection_id >= tl->max_connections_per_slot) {
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_BADCONNECTIONID;
+		pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+		return -1;
+	}
+	int state = tl->slots[slot_id].connections[connection_id].state;
+	pthread_mutex_unlock(&tl->slots[slot_id].slot_lock);
+
+	return state;
+}
+
+
+
+
+// ask the module for new data
+static int en50221_tl_poll_tc(struct en50221_transport_layer *tl,
+			      uint8_t slot_id, uint8_t connection_id)
+{
+	gettimeofday(&tl->slots[slot_id].connections[connection_id].
+		     tx_time, 0);
+
+	// send command
+	uint8_t hdr[3];
+	hdr[0] = T_DATA_LAST;
+	hdr[1] = 1;
+	hdr[2] = connection_id;
+	if (dvbca_link_write(tl->slots[slot_id].ca_hndl,
+	    		     tl->slots[slot_id].slot,
+			     connection_id, hdr, 3) < 0) {
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_CAWRITE;
+		return -1;
+	}
+	return 0;
+}
+
+// handle incoming data
+static int en50221_tl_process_data(struct en50221_transport_layer *tl,
+				   uint8_t slot_id, uint8_t * data,
+				   uint32_t data_length)
+{
+	int result;
+
+#ifdef DEBUG_RXDATA
+	printf("-------------------\n");
+	uint32_t ii = 0;
+	for (ii = 0; ii < data_length; ii++) {
+		printf("%02x: %02x\n", ii, data[ii]);
+	}
+	printf("+++++++++++++++++++\n");
+#endif
+
+	// process the received data
+	while (data_length) {
+		// parse the header
+		uint8_t tpdu_tag = data[0];
+		uint16_t asn_data_length;
+		int length_field_len;
+		if ((length_field_len = asn_1_decode(&asn_data_length, data + 1, data_length - 1)) < 0) {
+			print(LOG_LEVEL, ERROR, 1,
+			      "Received data with invalid asn from module on slot %02x\n",
+			      slot_id);
+			tl->error_slot = slot_id;
+			tl->error = EN50221ERR_BADCAMDATA;
+			return -1;
+		}
+		if ((asn_data_length < 1) ||
+		    (asn_data_length > (data_length - (1 + length_field_len)))) {
+			print(LOG_LEVEL, ERROR, 1,
+			      "Received data with invalid length from module on slot %02x\n",
+			      slot_id);
+			tl->error_slot = slot_id;
+			tl->error = EN50221ERR_BADCAMDATA;
+			return -1;
+		}
+		uint8_t connection_id = data[1 + length_field_len];
+		data += 1 + length_field_len + 1;
+		data_length -= (1 + length_field_len + 1);
+		asn_data_length--;
+
+		// check the connection_id
+		if (connection_id >= tl->max_connections_per_slot) {
+			print(LOG_LEVEL, ERROR, 1,
+			      "Received bad connection id %02x from module on slot %02x\n",
+			      connection_id, slot_id);
+			tl->error_slot = slot_id;
+			tl->error = EN50221ERR_BADCONNECTIONID;
+			return -1;
+		}
+		// process the TPDUs
+		switch (tpdu_tag) {
+		case T_C_T_C_REPLY:
+			if ((result = en50221_tl_handle_create_tc_reply(tl, slot_id, connection_id)) < 0) {
+				return -1;
+			}
+			break;
+		case T_DELETE_T_C:
+			if ((result = en50221_tl_handle_delete_tc(tl, slot_id, connection_id)) < 0) {
+				return -1;
+			}
+			break;
+		case T_D_T_C_REPLY:
+			if ((result = en50221_tl_handle_delete_tc_reply(tl, slot_id, connection_id)) < 0) {
+				return -1;
+			}
+			break;
+		case T_REQUEST_T_C:
+			if ((result = en50221_tl_handle_request_tc(tl, slot_id, connection_id)) < 0) {
+				return -1;
+			}
+			break;
+		case T_DATA_MORE:
+			if ((result = en50221_tl_handle_data_more(tl, slot_id,
+			     					  connection_id,
+								  data,
+								  asn_data_length)) < 0) {
+				return -1;
+			}
+			break;
+		case T_DATA_LAST:
+			if ((result = en50221_tl_handle_data_last(tl, slot_id,
+			     					  connection_id,
+								  data,
+								  asn_data_length)) < 0) {
+				return -1;
+			}
+			break;
+		case T_SB:
+			if ((result = en50221_tl_handle_sb(tl, slot_id,
+			     				   connection_id,
+							   data,
+							   asn_data_length)) < 0) {
+				return -1;
+			}
+			break;
+		default:
+			print(LOG_LEVEL, ERROR, 1,
+			      "Recieved unexpected TPDU tag %02x from module on slot %02x\n",
+			      tpdu_tag, slot_id);
+			tl->error_slot = slot_id;
+			tl->error = EN50221ERR_BADCAMDATA;
+			return -1;
+		}
+
+		// skip over the consumed data
+		data += asn_data_length;
+		data_length -= asn_data_length;
+	}
+
+	return 0;
+}
+
+static int en50221_tl_handle_create_tc_reply(struct en50221_transport_layer
+					     *tl, uint8_t slot_id,
+					     uint8_t connection_id)
+{
+	// set this connection to state active
+	if (tl->slots[slot_id].connections[connection_id].state == T_STATE_IN_CREATION) {
+		tl->slots[slot_id].connections[connection_id].state = T_STATE_ACTIVE;
+		tl->slots[slot_id].connections[connection_id].tx_time.tv_sec = 0;
+
+		// tell upper layers
+		pthread_mutex_lock(&tl->setcallback_lock);
+		en50221_tl_callback cb = tl->callback;
+		void *cb_arg = tl->callback_arg;
+		pthread_mutex_unlock(&tl->setcallback_lock);
+		if (cb)
+			cb(cb_arg, T_CALLBACK_REASON_CONNECTIONOPEN, NULL, 0, slot_id, connection_id);
+	} else {
+		print(LOG_LEVEL, ERROR, 1,
+		      "Received T_C_T_C_REPLY for connection not in "
+		      "T_STATE_IN_CREATION from module on slot %02x\n",
+		      slot_id);
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_BADCAMDATA;
+		return -1;
+	}
+
+	return 0;
+}
+
+static int en50221_tl_handle_delete_tc(struct en50221_transport_layer *tl,
+				       uint8_t slot_id,
+				       uint8_t connection_id)
+{
+	// immediately delete this connection and send D_T_C_REPLY
+	if (tl->slots[slot_id].connections[connection_id].state &
+	    (T_STATE_ACTIVE | T_STATE_IN_DELETION)) {
+		// clear down the slot
+		tl->slots[slot_id].connections[connection_id].state = T_STATE_IDLE;
+		if (tl->slots[slot_id].connections[connection_id].chain_buffer) {
+			free(tl->slots[slot_id].connections[connection_id].chain_buffer);
+		}
+		tl->slots[slot_id].connections[connection_id].chain_buffer = NULL;
+		tl->slots[slot_id].connections[connection_id].buffer_length = 0;
+
+		// send the reply
+		uint8_t hdr[3];
+		hdr[0] = T_D_T_C_REPLY;
+		hdr[1] = 1;
+		hdr[2] = connection_id;
+		if (dvbca_link_write(tl->slots[slot_id].ca_hndl,
+		    		     tl->slots[slot_id].slot,
+				     connection_id, hdr, 3) < 0) {
+			tl->error_slot = slot_id;
+			tl->error = EN50221ERR_CAWRITE;
+			return -1;
+		}
+		// tell upper layers
+		pthread_mutex_lock(&tl->setcallback_lock);
+		en50221_tl_callback cb = tl->callback;
+		void *cb_arg = tl->callback_arg;
+		pthread_mutex_unlock(&tl->setcallback_lock);
+		if (cb)
+			cb(cb_arg, T_CALLBACK_REASON_CONNECTIONCLOSE, NULL, 0, slot_id, connection_id);
+	} else {
+		print(LOG_LEVEL, ERROR, 1,
+		      "Received T_DELETE_T_C for inactive connection from module on slot %02x\n",
+		      slot_id);
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_BADCAMDATA;
+		return -1;
+	}
+
+	return 0;
+}
+
+static int en50221_tl_handle_delete_tc_reply(struct en50221_transport_layer
+					     *tl, uint8_t slot_id,
+					     uint8_t connection_id)
+{
+	// delete this connection, should be in T_STATE_IN_DELETION already
+	if (tl->slots[slot_id].connections[connection_id].state == T_STATE_IN_DELETION) {
+		tl->slots[slot_id].connections[connection_id].state = T_STATE_IDLE;
+	} else {
+		print(LOG_LEVEL, ERROR, 1,
+		      "Received T_D_T_C_REPLY received for connection not in "
+		      "T_STATE_IN_DELETION from module on slot %02x\n",
+		      slot_id);
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_BADCAMDATA;
+		return -1;
+	}
+
+	return 0;
+}
+
+static int en50221_tl_handle_request_tc(struct en50221_transport_layer *tl,
+					uint8_t slot_id,
+					uint8_t connection_id)
+{
+	// allocate a new connection if possible
+	int conid = en50221_tl_alloc_new_tc(tl, slot_id);
+	int ca_hndl = tl->slots[slot_id].ca_hndl;
+	if (conid == -1) {
+		print(LOG_LEVEL, ERROR, 1,
+		      "Too many connections requested by module on slot %02x\n",
+		      slot_id);
+
+		// send the error
+		uint8_t hdr[4];
+		hdr[0] = T_T_C_ERROR;
+		hdr[1] = 2;
+		hdr[2] = connection_id;
+		hdr[3] = 1;
+		if (dvbca_link_write(ca_hndl, tl->slots[slot_id].slot, connection_id, hdr, 4) < 0) {
+			tl->error_slot = slot_id;
+			tl->error = EN50221ERR_CAWRITE;
+			return -1;
+		}
+		tl->slots[slot_id].connections[connection_id].tx_time.
+		    tv_sec = 0;
+	} else {
+		// send the NEW_T_C on the connection we received it on
+		uint8_t hdr[4];
+		hdr[0] = T_NEW_T_C;
+		hdr[1] = 2;
+		hdr[2] = connection_id;
+		hdr[3] = conid;
+		if (dvbca_link_write(ca_hndl, tl->slots[slot_id].slot, connection_id, hdr, 4) < 0) {
+			tl->slots[slot_id].connections[conid].state = T_STATE_IDLE;
+			tl->error_slot = slot_id;
+			tl->error = EN50221ERR_CAWRITE;
+			return -1;
+		}
+		tl->slots[slot_id].connections[connection_id].tx_time.tv_sec = 0;
+
+		// send the CREATE_T_C on the new connnection
+		hdr[0] = T_CREATE_T_C;
+		hdr[1] = 1;
+		hdr[2] = conid;
+		if (dvbca_link_write(ca_hndl, tl->slots[slot_id].slot, conid, hdr, 3) < 0) {
+			tl->slots[slot_id].connections[conid].state = T_STATE_IDLE;
+			tl->error_slot = slot_id;
+			tl->error = EN50221ERR_CAWRITE;
+			return -1;
+		}
+		gettimeofday(&tl->slots[slot_id].connections[conid].tx_time, 0);
+
+		// tell upper layers
+		pthread_mutex_lock(&tl->setcallback_lock);
+		en50221_tl_callback cb = tl->callback;
+		void *cb_arg = tl->callback_arg;
+		pthread_mutex_unlock(&tl->setcallback_lock);
+		if (cb)
+			cb(cb_arg, T_CALLBACK_REASON_CAMCONNECTIONOPEN, NULL, 0, slot_id, conid);
+	}
+
+	return 0;
+}
+
+static int en50221_tl_handle_data_more(struct en50221_transport_layer *tl,
+				       uint8_t slot_id,
+				       uint8_t connection_id,
+				       uint8_t * data,
+				       uint32_t data_length)
+{
+	// connection in correct state?
+	if (tl->slots[slot_id].connections[connection_id].state != T_STATE_ACTIVE) {
+		print(LOG_LEVEL, ERROR, 1,
+		      "Received T_DATA_MORE for connection not in "
+		      "T_STATE_ACTIVE from module on slot %02x\n",
+		      slot_id);
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_BADCAMDATA;
+		return -1;
+	}
+	// a chained data packet is coming in, save
+	// it to the buffer and wait for more
+	tl->slots[slot_id].connections[connection_id].tx_time.tv_sec = 0;
+	int new_data_length =
+	    tl->slots[slot_id].connections[connection_id].buffer_length + data_length;
+	uint8_t *new_data_buffer =
+	    realloc(tl->slots[slot_id].connections[connection_id].chain_buffer, new_data_length);
+	if (new_data_buffer == NULL) {
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_OUTOFMEMORY;
+		return -1;
+	}
+	tl->slots[slot_id].connections[connection_id].chain_buffer = new_data_buffer;
+
+	memcpy(tl->slots[slot_id].connections[connection_id].chain_buffer +
+	       tl->slots[slot_id].connections[connection_id].buffer_length,
+	       data, data_length);
+	tl->slots[slot_id].connections[connection_id].buffer_length = new_data_length;
+
+	return 0;
+}
+
+static int en50221_tl_handle_data_last(struct en50221_transport_layer *tl,
+				       uint8_t slot_id,
+				       uint8_t connection_id,
+				       uint8_t * data,
+				       uint32_t data_length)
+{
+	// connection in correct state?
+	if (tl->slots[slot_id].connections[connection_id].state != T_STATE_ACTIVE) {
+		print(LOG_LEVEL, ERROR, 1,
+		      "Received T_DATA_LAST received for connection not in "
+		      "T_STATE_ACTIVE from module on slot %02x\n",
+		      slot_id);
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_BADCAMDATA;
+		return -1;
+	}
+	// last package of a chain or single package comes in
+	tl->slots[slot_id].connections[connection_id].tx_time.tv_sec = 0;
+	if (tl->slots[slot_id].connections[connection_id].chain_buffer == NULL) {
+		// single package => dispatch immediately
+		pthread_mutex_lock(&tl->setcallback_lock);
+		en50221_tl_callback cb = tl->callback;
+		void *cb_arg = tl->callback_arg;
+		pthread_mutex_unlock(&tl->setcallback_lock);
+
+		if (cb && data_length) {
+			pthread_mutex_unlock(&tl->slots[slot_id].
+					     slot_lock);
+			cb(cb_arg, T_CALLBACK_REASON_DATA, data, data_length, slot_id, connection_id);
+			pthread_mutex_lock(&tl->slots[slot_id].slot_lock);
+		}
+	} else {
+		int new_data_length =
+		    tl->slots[slot_id].connections[connection_id].buffer_length + data_length;
+		uint8_t *new_data_buffer =
+		    realloc(tl->slots[slot_id].connections[connection_id].chain_buffer, new_data_length);
+		if (new_data_buffer == NULL) {
+			tl->error_slot = slot_id;
+			tl->error = EN50221ERR_OUTOFMEMORY;
+			return -1;
+		}
+
+		memcpy(new_data_buffer +
+		       tl->slots[slot_id].connections[connection_id].
+		       buffer_length, data, data_length);
+
+		// clean the buffer position
+		tl->slots[slot_id].connections[connection_id].chain_buffer = NULL;
+		tl->slots[slot_id].connections[connection_id].buffer_length = 0;
+
+		// tell the upper layers
+		pthread_mutex_lock(&tl->setcallback_lock);
+		en50221_tl_callback cb = tl->callback;
+		void *cb_arg = tl->callback_arg;
+		pthread_mutex_unlock(&tl->setcallback_lock);
+		if (cb && data_length) {
+			pthread_mutex_unlock(&tl->slots[slot_id].
+					     slot_lock);
+			cb(cb_arg, T_CALLBACK_REASON_DATA, new_data_buffer,
+			   new_data_length, slot_id, connection_id);
+			pthread_mutex_lock(&tl->slots[slot_id].slot_lock);
+		}
+
+		free(new_data_buffer);
+	}
+
+	return 0;
+}
+
+static int en50221_tl_handle_sb(struct en50221_transport_layer *tl,
+				uint8_t slot_id, uint8_t connection_id,
+				uint8_t * data, uint32_t data_length)
+{
+	// is the connection id ok?
+	if (tl->slots[slot_id].connections[connection_id].state != T_STATE_ACTIVE) {
+		print(LOG_LEVEL, ERROR, 1,
+		      "Received T_SB for connection not in T_STATE_ACTIVE from module on slot %02x\n",
+		      slot_id);
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_BADCAMDATA;
+		return -1;
+	}
+	// did we get enough data in the T_SB?
+	if (data_length != 1) {
+		print(LOG_LEVEL, ERROR, 1,
+		      "Recieved T_SB with invalid length from module on slot %02x\n",
+		      slot_id);
+		tl->error_slot = slot_id;
+		tl->error = EN50221ERR_BADCAMDATA;
+		return -1;
+	}
+	// tell it to send the data if it says there is some
+	if (data[0] & 0x80) {
+		int ca_hndl = tl->slots[slot_id].ca_hndl;
+
+		// send the RCV
+		uint8_t hdr[3];
+		hdr[0] = T_RCV;
+		hdr[1] = 1;
+		hdr[2] = connection_id;
+		if (dvbca_link_write(ca_hndl, tl->slots[slot_id].slot, connection_id, hdr, 3) < 0) {
+			tl->error_slot = slot_id;
+			tl->error = EN50221ERR_CAWRITE;
+			return -1;
+		}
+		gettimeofday(&tl->slots[slot_id].connections[connection_id].tx_time, 0);
+
+	} else {
+		// no data - indicate not waiting for anything now
+		tl->slots[slot_id].connections[connection_id].tx_time.tv_sec = 0;
+	}
+
+	return 0;
+}
+
+static int en50221_tl_alloc_new_tc(struct en50221_transport_layer *tl,
+				   uint8_t slot_id)
+{
+	// we browse through the array of connection
+	// types, to look for the first unused one
+	int i, conid = -1;
+	for (i = 1; i < tl->max_connections_per_slot; i++) {
+		if (tl->slots[slot_id].connections[i].state == T_STATE_IDLE) {
+			conid = i;
+			break;
+		}
+	}
+	if (conid == -1) {
+		print(LOG_LEVEL, ERROR, 1,
+		      "CREATE_T_C failed: no more connections available\n");
+		return -1;
+	}
+	// set up the connection struct
+	tl->slots[slot_id].connections[conid].state = T_STATE_IN_CREATION;
+	tl->slots[slot_id].connections[conid].chain_buffer = NULL;
+	tl->slots[slot_id].connections[conid].buffer_length = 0;
+
+	return conid;
+}
+
+static void queue_message(struct en50221_transport_layer *tl,
+			  uint8_t slot_id, uint8_t connection_id,
+			  struct en50221_message *msg)
+{
+	msg->next = NULL;
+	if (tl->slots[slot_id].connections[connection_id].send_queue_tail) {
+		tl->slots[slot_id].connections[connection_id].send_queue_tail->next = msg;
+		tl->slots[slot_id].connections[connection_id].send_queue_tail = msg;
+	} else {
+		tl->slots[slot_id].connections[connection_id].send_queue = msg;
+		tl->slots[slot_id].connections[connection_id].send_queue_tail = msg;
+	}
+}