/*
* Function for the PANA PDU dissector.
*/
static void
dissect_pana_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_tree *pana_tree = NULL;
guint16 flags;
guint16 msg_type;
guint32 msg_length;
guint32 avp_length;
guint32 seq_num;
conversation_t *conversation;
pana_conv_info_t *pana_info;
pana_transaction_t *pana_trans;
int offset = 0;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "PANA");
col_clear(pinfo->cinfo, COL_INFO);
/* Get message length, type and flags */
msg_length = tvb_get_ntohs(tvb, 2);
flags = tvb_get_ntohs(tvb, 4);
msg_type = tvb_get_ntohs(tvb, 6);
seq_num = tvb_get_ntohl(tvb, 12);
avp_length = msg_length - 16;
col_add_fstr(pinfo->cinfo, COL_INFO, "Type %s-%s",
val_to_str(msg_type, msg_type_names, "Unknown (%d)"),
val_to_str(flags & PANA_FLAG_R, msg_subtype_names, "Unknown (%d)"));
/* Make the protocol tree */
if (tree) {
proto_item *ti;
ti = proto_tree_add_item(tree, proto_pana, tvb, 0, -1, ENC_NA);
pana_tree = proto_item_add_subtree(ti, ett_pana);
}
/*
* We need to track some state for this protocol on a per conversation
* basis so we can do neat things like request/response tracking
*/
conversation = find_or_create_conversation(pinfo);
/*
* Do we already have a state structure for this conv
*/
pana_info = (pana_conv_info_t *)conversation_get_proto_data(conversation, proto_pana);
if (!pana_info) {
/* No. Attach that information to the conversation, and add
* it to the list of information structures.
*/
pana_info = wmem_new(wmem_file_scope(), pana_conv_info_t);
pana_info->pdus=wmem_map_new(wmem_file_scope(), g_direct_hash, g_direct_equal);
conversation_add_proto_data(conversation, proto_pana, pana_info);
}
if(!pinfo->fd->flags.visited){
if(flags&PANA_FLAG_R){
/* This is a request */
pana_trans=wmem_new(wmem_file_scope(), pana_transaction_t);
pana_trans->req_frame=pinfo->num;
pana_trans->rep_frame=0;
pana_trans->req_time=pinfo->abs_ts;
wmem_map_insert(pana_info->pdus, GUINT_TO_POINTER(seq_num), (void *)pana_trans);
} else {
pana_trans=(pana_transaction_t *)wmem_map_lookup(pana_info->pdus, GUINT_TO_POINTER(seq_num));
if(pana_trans){
pana_trans->rep_frame=pinfo->num;
}
}
} else {
pana_trans=(pana_transaction_t *)wmem_map_lookup(pana_info->pdus, GUINT_TO_POINTER(seq_num));
}
if(!pana_trans){
/* create a "fake" pana_trans structure */
pana_trans=wmem_new(wmem_packet_scope(), pana_transaction_t);
pana_trans->req_frame=0;
pana_trans->rep_frame=0;
pana_trans->req_time=pinfo->abs_ts;
}
/* print state tracking in the tree */
if(flags&PANA_FLAG_R){
/* This is a request */
if(pana_trans->rep_frame){
proto_item *it;
it=proto_tree_add_uint(pana_tree, hf_pana_response_in, tvb, 0, 0, pana_trans->rep_frame);
PROTO_ITEM_SET_GENERATED(it);
}
} else {
/* This is a reply */
if(pana_trans->req_frame){
proto_item *it;
nstime_t ns;
it=proto_tree_add_uint(pana_tree, hf_pana_response_to, tvb, 0, 0, pana_trans->req_frame);
PROTO_ITEM_SET_GENERATED(it);
nstime_delta(&ns, &pinfo->abs_ts, &pana_trans->req_time);
it=proto_tree_add_time(pana_tree, hf_pana_response_time, tvb, 0, 0, &ns);
PROTO_ITEM_SET_GENERATED(it);
}
}
/* Reserved field */
proto_tree_add_item(pana_tree, hf_pana_reserved_type, tvb, offset, 2, ENC_NA);
offset += 2;
/* Length */
proto_tree_add_item(pana_tree, hf_pana_length_type, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
/* Flags */
dissect_pana_flags(pana_tree, tvb, offset, flags);
offset += 2;
/* Message Type */
proto_tree_add_uint_format_value(pana_tree, hf_pana_msg_type, tvb,
offset, 2, msg_type, "%s-%s (%d)",
val_to_str(msg_type, msg_type_names, "Unknown (%d)"),
val_to_str(flags & PANA_FLAG_R, msg_subtype_names, "Unknown (%d)"),
msg_type);
offset += 2;
/* Session ID */
proto_tree_add_item(pana_tree, hf_pana_session_id, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
/* Sequence Number */
proto_tree_add_item(pana_tree, hf_pana_seqnumber, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
/* AVPs */
if(avp_length != 0){
tvbuff_t *avp_tvb;
proto_tree *avp_tree;
avp_tvb = tvb_new_subset_length(tvb, offset, avp_length);
avp_tree = proto_tree_add_subtree(pana_tree, tvb, offset, avp_length, ett_pana_avp, NULL, "Attribute Value Pairs");
dissect_avps(avp_tvb, pinfo, avp_tree);
}
}
/*
* Function for the PANA PDU dissector.
*/
static void
dissect_pana_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_tree *pana_tree=NULL;
proto_tree *avp_tree=NULL;
proto_item *ti=NULL;
proto_item *avp_item=NULL;
tvbuff_t *avp_tvb;
guint16 flags = 0;
guint16 msg_type;
gint16 msg_length;
gint16 avp_length;
guint32 session_id;
guint32 seq_num;
conversation_t *conversation;
pana_conv_info_t *pana_info;
pana_transaction_t *pana_trans;
int offset = 0;
/* Get message length, type and flags */
msg_length = tvb_get_ntohs(tvb, 2);
flags = tvb_get_ntohs(tvb, 4);
msg_type = tvb_get_ntohs(tvb, 6);
session_id = tvb_get_ntohl(tvb, 8);
seq_num = tvb_get_ntohl(tvb, 12);
avp_length = msg_length-16;
/* Make entries in Protocol column and Info column on summary display */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "PANA");
if (check_col(pinfo->cinfo, COL_INFO)) {
col_clear(pinfo->cinfo, COL_INFO);
col_add_fstr(pinfo->cinfo, COL_INFO, "Type %s-%s",
val_to_str(msg_type, msg_type_names, "Unknown (%d)"),
val_to_str(flags & PANA_FLAG_R, msg_subtype_names, "Unknown (%d)"));
}
/* Make the protocol tree */
if (tree) {
ti = proto_tree_add_item(tree, proto_pana, tvb, 0, -1, FALSE);
pana_tree = proto_item_add_subtree(ti, ett_pana);
}
/*
* We need to track some state for this protocol on a per conversation
* basis so we can do neat things like request/response tracking
*/
/*
* Do we have a conversation for this connection?
*/
conversation = find_conversation(pinfo->fd->num,
&pinfo->src, &pinfo->dst,
pinfo->ptype,
pinfo->srcport, pinfo->destport, 0);
if (conversation == NULL) {
/* We don't yet have a conversation, so create one. */
conversation = conversation_new(pinfo->fd->num,
&pinfo->src, &pinfo->dst,
pinfo->ptype,
pinfo->srcport, pinfo->destport, 0);
}
/*
* Do we already have a state structure for this conv
*/
pana_info = conversation_get_proto_data(conversation, proto_pana);
if (!pana_info) {
/* No. Attach that information to the conversation, and add
* it to the list of information structures.
*/
pana_info = se_alloc(sizeof(pana_conv_info_t));
pana_info->pdus=se_tree_create_non_persistent(EMEM_TREE_TYPE_RED_BLACK, "pana_pdus");
conversation_add_proto_data(conversation, proto_pana, pana_info);
}
if(!pinfo->fd->flags.visited){
if(flags&PANA_FLAG_R){
/* This is a request */
pana_trans=se_alloc(sizeof(pana_transaction_t));
pana_trans->req_frame=pinfo->fd->num;
pana_trans->rep_frame=0;
pana_trans->req_time=pinfo->fd->abs_ts;
se_tree_insert32(pana_info->pdus, seq_num, (void *)pana_trans);
} else {
pana_trans=se_tree_lookup32(pana_info->pdus, seq_num);
if(pana_trans){
pana_trans->rep_frame=pinfo->fd->num;
}
}
} else {
pana_trans=se_tree_lookup32(pana_info->pdus, seq_num);
}
if(!pana_trans){
/* create a "fake" pana_trans structure */
pana_trans=ep_alloc(sizeof(pana_transaction_t));
pana_trans->req_frame=0;
pana_trans->rep_frame=0;
pana_trans->req_time=pinfo->fd->abs_ts;
}
/* print state tracking in the tree */
if(flags&PANA_FLAG_R){
/* This is a request */
if(pana_trans->rep_frame){
proto_item *it;
it=proto_tree_add_uint(pana_tree, hf_pana_response_in, tvb, 0, 0, pana_trans->rep_frame);
PROTO_ITEM_SET_GENERATED(it);
}
} else {
/* This is a reply */
if(pana_trans->req_frame){
proto_item *it;
nstime_t ns;
it=proto_tree_add_uint(pana_tree, hf_pana_response_to, tvb, 0, 0, pana_trans->req_frame);
PROTO_ITEM_SET_GENERATED(it);
nstime_delta(&ns, &pinfo->fd->abs_ts, &pana_trans->req_time);
it=proto_tree_add_time(pana_tree, hf_pana_time, tvb, 0, 0, &ns);
PROTO_ITEM_SET_GENERATED(it);
}
}
/* Reserved field */
proto_tree_add_item(pana_tree, hf_pana_reserved_type, tvb, offset, 2, FALSE);
offset += 2;
/* Length */
proto_tree_add_item(pana_tree, hf_pana_length_type, tvb, offset, 2, FALSE);
offset += 2;
/* Flags */
dissect_pana_flags(pana_tree, tvb, offset, flags);
offset += 2;
/* Message Type */
proto_tree_add_uint_format_value(pana_tree, hf_pana_msg_type, tvb,
offset, 2, msg_type, "%s-%s (%d)",
val_to_str(msg_type, msg_type_names, "Unknown (%d)"),
val_to_str(flags & PANA_FLAG_R, msg_subtype_names, "Unknown (%d)"),
msg_type);
offset += 2;
/* Session ID */
proto_tree_add_item(pana_tree, hf_pana_session_id, tvb, offset, 4, FALSE);
offset += 4;
/* Sequence Number */
proto_tree_add_item(pana_tree, hf_pana_seqnumber, tvb, offset, 4, FALSE);
offset += 4;
/* AVPs */
if(avp_length>0){
avp_tvb = tvb_new_subset(tvb, offset, avp_length, avp_length);
avp_item = proto_tree_add_text(pana_tree, tvb, offset, avp_length, "Attribute Value Pairs");
avp_tree = proto_item_add_subtree(avp_item, ett_pana_avp);
if (avp_tree != NULL) {
dissect_avps(avp_tvb, pinfo, avp_tree);
}
}
}
/*
* Function for AVP dissector.
*/
static void
dissect_avps(tvbuff_t *tvb, packet_info *pinfo, proto_tree *avp_tree)
{
gint offset;
guint16 avp_code;
guint16 avp_flags;
guint32 avp_length;
guint16 avp_type;
guint32 vendor_id;
guint32 avp_hdr_length;
guint32 avp_data_length, result_code;
guint32 padding;
gint32 buffer_length;
tvbuff_t *group_tvb;
tvbuff_t *eap_tvb;
tvbuff_t *encap_tvb;
proto_tree *single_avp_tree;
proto_tree *avp_eap_tree;
proto_tree *avp_encap_tree;
offset = 0;
buffer_length = tvb_reported_length(tvb);
/* Go through all AVPs */
while (buffer_length > 0) {
avp_code = tvb_get_ntohs(tvb, offset);
avp_flags = tvb_get_ntohs(tvb, offset + 2);
avp_data_length = tvb_get_ntohs(tvb, offset + 4);
/* Check AVP flags for vendor specific AVP */
if (avp_flags & PANA_AVP_FLAG_V) {
vendor_id = tvb_get_ntohl(tvb, 8);
avp_hdr_length = 12;
} else {
vendor_id = 0;
avp_hdr_length = 8;
}
avp_length = avp_hdr_length + avp_data_length;
/* Check AVP type */
avp_type = pana_avp_get_type(avp_code, vendor_id);
/* Check padding */
padding = (4 - (avp_length % 4)) % 4;
single_avp_tree = proto_tree_add_subtree_format(avp_tree, tvb, offset, avp_length + padding,
ett_pana_avp_info, NULL, "%s (%s) length: %d bytes (%d padded bytes)",
val_to_str(avp_code, avp_code_names, "Unknown (%d)"),
val_to_str(avp_type, avp_type_names, "Unknown (%d)"),
avp_length,
avp_length + padding);
/* AVP Code */
proto_tree_add_uint_format_value(single_avp_tree, hf_pana_avp_code, tvb,
offset, 2, avp_code, "%s (%u)",
val_to_str(avp_code, avp_code_names, "Unknown (%d)"),
avp_code);
offset += 2;
/* AVP Flags */
dissect_pana_avp_flags(single_avp_tree, tvb, offset, avp_flags);
offset += 2;
/* AVP Length */
proto_tree_add_item(single_avp_tree, hf_pana_avp_data_length, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
/* Reserved */
proto_tree_add_item(single_avp_tree, hf_pana_avp_reserved, tvb, offset, 2, ENC_NA);
offset += 2;
if (avp_flags & PANA_AVP_FLAG_V) {
/* Vendor ID */
proto_tree_add_item(single_avp_tree, hf_pana_avp_vendorid, tvb, offset, 4, ENC_BIG_ENDIAN);
offset += 4;
}
if (! (avp_flags & PANA_AVP_FLAG_V)) {
/* AVP Value */
switch(avp_type) {
case PANA_GROUPED: {
proto_tree *avp_group_tree;
avp_group_tree = proto_tree_add_subtree(single_avp_tree,
tvb, offset, avp_data_length,
ett_pana_avp, NULL, "Grouped AVP");
group_tvb = tvb_new_subset(tvb, offset,
MIN(avp_data_length, tvb_reported_length(tvb)-offset),
avp_data_length);
dissect_avps(group_tvb, pinfo, avp_group_tree);
break;
}
case PANA_UTF8STRING: {
proto_tree_add_item(single_avp_tree, hf_pana_avp_data_string, tvb,
offset, avp_data_length, ENC_UTF_8|ENC_NA);
break;
}
case PANA_OCTET_STRING: {
proto_tree_add_item(single_avp_tree, hf_pana_avp_data_bytes, tvb,
offset, avp_data_length, ENC_NA);
break;
}
case PANA_INTEGER32: {
proto_tree_add_item(single_avp_tree, hf_pana_avp_data_int32, tvb,
offset, 4, ENC_BIG_ENDIAN);
break;
}
case PANA_UNSIGNED32: {
proto_tree_add_item(single_avp_tree, hf_pana_avp_data_uint32, tvb,
offset, 4, ENC_BIG_ENDIAN);
break;
}
case PANA_INTEGER64: {
proto_tree_add_item(single_avp_tree, hf_pana_avp_data_int64, tvb,
offset, 8, ENC_BIG_ENDIAN);
break;
}
case PANA_UNSIGNED64: {
proto_tree_add_item(single_avp_tree, hf_pana_avp_data_uint64, tvb,
offset, 8, ENC_BIG_ENDIAN);
break;
}
case PANA_ENUMERATED: {
proto_tree_add_item(single_avp_tree, hf_pana_avp_data_enumerated, tvb,
offset, 4, ENC_BIG_ENDIAN);
break;
}
case PANA_RESULT_CODE: {
result_code = tvb_get_ntohl(tvb, offset);
proto_tree_add_uint_format(single_avp_tree, hf_pana_avp_code, tvb, offset, avp_data_length,
result_code, "Value: %d (%s)",
result_code,
val_to_str(result_code, avp_code_names, "Unknown (%d)"));
break;
}
case PANA_EAP: {
avp_eap_tree = proto_tree_add_subtree(single_avp_tree,
tvb, offset, avp_data_length,
ett_pana_avp, NULL, "AVP Value (EAP packet)");
eap_tvb = tvb_new_subset_length(tvb, offset, avp_data_length);
DISSECTOR_ASSERT_HINT(eap_handle, "EAP Dissector not available");
call_dissector(eap_handle, eap_tvb, pinfo, avp_eap_tree);
break;
}
case PANA_ENCAPSULATED: {
avp_encap_tree = proto_tree_add_subtree(single_avp_tree,
tvb, offset, avp_data_length,
ett_pana_avp, NULL, "AVP Value (PANA packet)");
encap_tvb = tvb_new_subset_length(tvb, offset, avp_data_length);
dissect_pana_pdu(encap_tvb, pinfo, avp_encap_tree);
break;
}
}
}
offset += avp_data_length + padding;
/* Update the buffer length */
buffer_length -= avp_length + padding;
}
}
/*
* Function for AVP dissector.
*/
static void
dissect_avps(tvbuff_t *tvb, packet_info *pinfo, proto_tree *avp_tree)
{
gint offset;
guint16 avp_code;
guint16 avp_flags;
guint16 avp_length;
guint16 avp_type;
guint32 vendor_id;
guint16 avp_hdr_length;
guint16 avp_data_length;
guint16 padding;
guint16 buffer_length;
int bad_avp = FALSE;
tvbuff_t *group_tvb;
tvbuff_t *eap_tvb;
proto_item *single_avp_item;
proto_tree *single_avp_tree;
proto_item *avp_group_item;
proto_tree *avp_group_tree;
proto_item *avp_eap_item;
proto_tree *avp_eap_tree;
offset = 0;
buffer_length = tvb_reported_length(tvb);
/* Go through all AVPs */
while (buffer_length > 0) {
avp_code = tvb_get_ntohs(tvb, offset);
avp_flags = tvb_get_ntohs(tvb, offset + 2);
avp_length = tvb_get_ntohs(tvb, offset + 4);
/* Check AVP flags for vendor specific AVP */
if (avp_flags & PANA_AVP_FLAG_V) {
vendor_id = tvb_get_ntohl(tvb, 8);
avp_hdr_length = 12;
} else {
vendor_id = 0;
avp_hdr_length = 8;
}
/* Check AVP type */
avp_type = pana_avp_get_type(avp_code, vendor_id);
/* Check AVP length */
if (avp_length < avp_hdr_length) {
single_avp_item = proto_tree_add_text(avp_tree, tvb, offset, avp_length,
"%s (%s) length: %d bytes (shorter than header length %d)",
val_to_str(avp_code, avp_code_names, "Unknown (%d)"),
val_to_str(avp_type, avp_type_names, "Unknown (%d)"),
avp_length,
avp_hdr_length);
single_avp_tree = proto_item_add_subtree(single_avp_item, ett_pana_avp_info);
if (single_avp_tree != NULL) {
/* AVP Code */
proto_tree_add_uint_format_value(single_avp_tree, hf_pana_avp_code, tvb,
offset, 2, avp_code, "%s (%u)",
val_to_str(avp_code, avp_code_names, "Unknown (%d)"),
avp_code);
offset += 2;
/* AVP Flags */
dissect_pana_avp_flags(single_avp_tree, tvb, offset, avp_flags);
offset += 2;
/* AVP Length */
proto_tree_add_item(single_avp_tree, hf_pana_avp_length, tvb, offset, 2, FALSE);
offset += 2;
}
return;
}
/* Check AVP flags */
if (avp_flags & PANA_AVP_FLAG_RES) bad_avp = TRUE;
/* Check padding */
padding = (4 - (avp_length % 4)) % 4;
single_avp_item = proto_tree_add_text(avp_tree, tvb, offset, avp_length + padding,
"%s (%s) length: %d bytes (%d padded bytes)",
val_to_str(avp_code, avp_code_names, "Unknown (%d)"),
val_to_str(avp_type, avp_type_names, "Unknown (%d)"),
avp_length,
avp_length + padding);
single_avp_tree = proto_item_add_subtree(single_avp_item, ett_pana_avp_info);
/* AVP data length */
avp_data_length = avp_length - avp_hdr_length;
if (single_avp_tree != NULL) {
/* AVP Code */
proto_tree_add_uint_format_value(single_avp_tree, hf_pana_avp_code, tvb,
offset, 2, avp_code, "%s (%u)",
val_to_str(avp_code, avp_code_names, "Unknown (%d)"),
avp_code);
}
offset += 2;
if (single_avp_tree != NULL) {
/* AVP Flags */
dissect_pana_avp_flags(single_avp_tree, tvb, offset, avp_flags);
}
offset += 2;
if (single_avp_tree != NULL) {
/* AVP Length */
proto_tree_add_item(single_avp_tree, hf_pana_avp_length, tvb, offset, 2, FALSE);
}
offset += 2;
if (single_avp_tree != NULL) {
/* Reserved */
proto_tree_add_item(single_avp_tree, hf_pana_avp_reserved, tvb, offset, 2, FALSE);
}
offset += 2;
if (avp_flags & PANA_AVP_FLAG_V) {
if (single_avp_tree != NULL) {
/* Vendor ID */
proto_tree_add_item(single_avp_tree, hf_pana_avp_vendorid, tvb, offset, 4, FALSE);
}
offset += 4;
}
if (avp_flags & PANA_AVP_FLAG_V) {
/* AVP Value */
switch(avp_type) {
case PANA_GROUPED: {
avp_group_item = proto_tree_add_text(single_avp_tree,
tvb, offset, avp_data_length,
"Grouped AVP");
avp_group_tree = proto_item_add_subtree(avp_group_item, ett_pana_avp);
group_tvb = tvb_new_subset(tvb, offset,
MIN(avp_data_length, tvb_length(tvb)-offset), avp_data_length);
if (avp_group_tree != NULL) {
dissect_avps(group_tvb, pinfo, avp_group_tree);
}
break;
}
case PANA_UTF8STRING: {
const guint8 *data;
data = tvb_get_ptr(tvb, offset, avp_data_length);
proto_tree_add_string_format(single_avp_tree, hf_pana_avp_data_string, tvb,
offset, avp_data_length, data,
"UTF8String: %*.*s",
avp_data_length, avp_data_length, data);
break;
}
case PANA_OCTET_STRING: {
proto_tree_add_bytes_format(single_avp_tree, hf_pana_avp_data_bytes, tvb,
offset, avp_data_length,
tvb_get_ptr(tvb, offset, avp_data_length),
"Hex Data Highlighted Below");
break;
}
case PANA_INTEGER32: {
proto_tree_add_item(single_avp_tree, hf_pana_avp_data_int32, tvb,
offset, 4, FALSE);
break;
}
case PANA_UNSIGNED32: {
proto_tree_add_item(single_avp_tree, hf_pana_avp_data_uint32, tvb,
offset, 4, FALSE);
break;
}
case PANA_INTEGER64: {
proto_tree_add_item(single_avp_tree, hf_pana_avp_data_int64, tvb,
offset, 8, FALSE);
break;
}
case PANA_UNSIGNED64: {
proto_tree_add_item(single_avp_tree, hf_pana_avp_data_uint64, tvb,
offset, 8, FALSE);
break;
}
case PANA_ENUMERATED: {
proto_tree_add_item(single_avp_tree, hf_pana_avp_data_enumerated, tvb,
offset, 4, FALSE);
break;
}
case PANA_RESULT_CODE: {
proto_tree_add_text(single_avp_tree, tvb, offset, avp_data_length,
"Value: %d (%s)",
tvb_get_ntohl(tvb, offset),
val_to_str(tvb_get_ntohs(tvb, offset), avp_code_names, "Unknown (%d)"));
break;
}
case PANA_EAP: {
avp_eap_item = proto_tree_add_text(single_avp_tree,
tvb, offset, avp_data_length,
"AVP Value (EAP packet)");
avp_eap_tree = proto_item_add_subtree(avp_eap_item, ett_pana_avp);
eap_tvb = tvb_new_subset(tvb, offset, avp_data_length, avp_data_length);
if (eap_handle != NULL) {
call_dissector(eap_handle, eap_tvb, pinfo, avp_eap_tree);
}
break;
}
}
}
offset += avp_data_length + padding;
/* Update the buffer length */
buffer_length -= avp_length + padding;
}
}