static int
dissect_bfcp_attributes(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offset, int bfcp_payload_length)
{
proto_item *ti, *item;
proto_tree *bfcp_attr_tree = NULL;
gint attr_start_offset;
gint length;
guint8 attribute_type;
gint read_attr = 0;
guint8 first_byte, pad_len;
while ((tvb_reported_length_remaining(tvb, offset) >= 2) &&
((bfcp_payload_length - read_attr) >= 2))
{
attr_start_offset = offset;
first_byte = tvb_get_guint8(tvb, offset);
/* Padding so continue to next attribute */
if (first_byte == 0){
read_attr++;
continue;
}
ti = proto_tree_add_item(tree, hf_bfcp_attribute_types, tvb, offset, 1, ENC_BIG_ENDIAN);
bfcp_attr_tree = proto_item_add_subtree(ti, ett_bfcp_attr);
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_attribute_types_m_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
attribute_type = (first_byte & 0xFE) >> 1;
offset++;
/* Length: This 8-bit field contains the length of the attribute in
* octets, excluding any padding defined for specific attributes. The
* length of attributes that are not grouped includes the Type, 'M' bit,
* and Length fields. The Length in grouped attributes is the length of
* the grouped attribute itself (including Type, 'M' bit, and Length
* fields) plus the total length (including padding) of all the included
* attributes.
*/
item = proto_tree_add_item(bfcp_attr_tree, hf_bfcp_attribute_length, tvb, offset, 1, ENC_BIG_ENDIAN);
length = tvb_get_guint8(tvb, offset);
offset++;
pad_len = 0; /* Default to no padding*/
switch(attribute_type){
case 1: /* Beneficiary ID */
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_beneficiary_id, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
break;
case 2: /* FLOOR-ID */
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_floor_id, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
break;
case 3: /* FLOOR-REQUEST-ID */
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_floor_request_id, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
break;
case 4: /* PRIORITY */
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_priority, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
break;
case 5: /* REQUEST-STATUS */
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_request_status, tvb, offset,1, ENC_BIG_ENDIAN);
offset++;
/* Queue Position */
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_queue_pos, tvb, offset,1, ENC_BIG_ENDIAN);
offset++;
break;
case 6: /* ERROR-CODE */
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_error_code, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
if(length>3){
/* We have Error Specific Details */
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_error_specific_details, tvb, offset, length-3, ENC_NA);
}
offset = offset + length-3;
pad_len = length & 0x03;
if(pad_len != 0){
pad_len = 4 - pad_len;
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_padding, tvb, offset, pad_len, ENC_NA);
}
offset = offset + pad_len;
break;
case 7: /* ERROR-INFO */
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_error_info_text, tvb, offset, length-3, ENC_ASCII|ENC_NA);
offset = offset + length-3;
pad_len = length & 0x03;
if(pad_len != 0){
pad_len = 4 - pad_len;
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_padding, tvb, offset, pad_len, ENC_NA);
}
offset = offset + pad_len;
break;
case 8: /* PARTICIPANT-PROVIDED-INFO */
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_part_prov_info_text, tvb, offset, length-3, ENC_ASCII|ENC_NA);
offset = offset + length-3;
pad_len = length & 0x03;
if(pad_len != 0){
pad_len = 4 - pad_len;
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_padding, tvb, offset, pad_len, ENC_NA);
}
offset = offset + pad_len;
break;
case 9: /* STATUS-INFO */
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_status_info_text, tvb, offset, length-3, ENC_ASCII|ENC_NA);
offset = offset + length-3;
pad_len = length & 0x03;
if(pad_len != 0){
pad_len = 4 - pad_len;
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_padding, tvb, offset, pad_len, ENC_NA);
}
offset = offset + pad_len;
break;
case 10: /* SUPPORTED-ATTRIBUTES */
while(offset < (attr_start_offset+length)){
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_supp_attr, tvb, offset, 1, ENC_BIG_ENDIAN);
offset+=1;
}
pad_len = length & 0x03;
if(pad_len != 0){
pad_len = 4 - pad_len;
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_padding, tvb, offset, pad_len, ENC_NA);
}
offset = offset + pad_len;
break;
case 11: /* SUPPORTED-PRIMITIVES */
while(offset < (attr_start_offset+length)){
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_supp_prim, tvb, offset, 1, ENC_BIG_ENDIAN);
offset+=1;
}
pad_len = length & 0x03;
if(pad_len != 0){
pad_len = 4 - pad_len;
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_padding, tvb, offset, pad_len, ENC_NA);
}
offset = offset + pad_len;
break;
case 12: /* USER-DISPLAY-NAME */
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_user_disp_name, tvb, offset, length-3, ENC_ASCII|ENC_NA);
offset = offset + length-3;
pad_len = length & 0x03;
if(pad_len != 0){
pad_len = 4 - pad_len;
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_padding, tvb, offset, pad_len, ENC_NA);
}
offset = offset + pad_len;
break;
case 13: /* USER-URI */
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_user_uri, tvb, offset, length-3, ENC_ASCII|ENC_NA);
offset = offset + length-3;
pad_len = length & 0x03;
if(pad_len != 0){
pad_len = 4 - pad_len;
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_padding, tvb, offset, pad_len, ENC_NA);
}
offset = offset + pad_len;
break;
case 14: /* BENEFICIARY-INFORMATION */
/* The BENEFICIARY-INFORMATION attribute is a grouped attribute that
* consists of a header, which is referred to as BENEFICIARY-
* INFORMATION-HEADER, followed by a sequence of attributes.
*/
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_beneficiary_id, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
offset = dissect_bfcp_attributes(tvb, pinfo, bfcp_attr_tree, offset, length -4);
break;
case 15: /* FLOOR-REQUEST-INFORMATION */
/* The FLOOR-REQUEST-INFORMATION attribute is a grouped attribute that
* consists of a header, which is referred to as FLOOR-REQUEST-
* INFORMATION-HEADER, followed by a sequence of attributes.
*/
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_floor_request_id, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
offset = dissect_bfcp_attributes(tvb, pinfo, bfcp_attr_tree, offset, length -4);
break;
case 16: /* REQUESTED-BY-INFORMATION */
/* The REQUESTED-BY-INFORMATION attribute is a grouped attribute that
* consists of a header, which is referred to as FLOOR-REQUEST-STATUS-
* -HEADER, followed by a sequence of attributes.
*/
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_req_by_id, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
offset = dissect_bfcp_attributes(tvb, pinfo, bfcp_attr_tree, offset, length -4);
break;
case 17: /* FLOOR-REQUEST-STATUS */
/* The FLOOR-REQUEST-STATUS attribute is a grouped attribute that
* consists of a header, which is referred to as OVERALL-REQUEST-STATUS-
* -HEADER, followed by a sequence of attributes.
*/
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_floor_id, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
offset = dissect_bfcp_attributes(tvb, pinfo, bfcp_attr_tree, offset, length -4);
break;
case 18: /* OVERALL-REQUEST-STATUS */
/* The OVERALL-REQUEST-STATUS attribute is a grouped attribute that
* consists of a header, which is referred to as FLOOR-REQUEST-
* INFORMATION-HEADER, followed by a sequence of attributes.
*/
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_floor_request_id, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
offset = dissect_bfcp_attributes(tvb, pinfo, bfcp_attr_tree, offset, length -4);
break;
default:
proto_tree_add_item(bfcp_attr_tree, hf_bfcp_payload, tvb, offset, length-2, ENC_NA);
offset = offset + length - 2;
break;
}
if ((length+pad_len) < (offset - attr_start_offset)){
expert_add_info_format(pinfo, item, &ei_bfcp_attribute_length_too_small,
"Attribute length is too small (%d bytes)", length);
break;
}
read_attr = read_attr + length;
}
return offset;
}
/* Code to actually dissect BFCP packets */
static void
dissect_bfcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
int offset = 0;
guint8 primitive;
const gchar *str;
gint bfcp_payload_length;
proto_tree *bfcp_tree = NULL;
primitive = tvb_get_guint8(tvb, 1);
str = try_val_to_str(primitive, map_bfcp_primitive);
/* Make entries in Protocol column and Info column on summary display*/
col_set_str(pinfo->cinfo, COL_PROTOCOL, "BFCP");
col_add_str(pinfo->cinfo, COL_INFO, str);
if (tree) {
proto_item *ti;
ti = proto_tree_add_item(tree, proto_bfcp, tvb, 0, -1, ENC_NA);
bfcp_tree = proto_item_add_subtree(ti, ett_bfcp);
/*
The following is the format of the common header.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ver |R|F| Res | Primitive | Payload Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Conference ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction ID | User ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Fragment Offset (if F is set) | Fragment Length (if F is set) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
/* Add items to BFCP tree */
proto_tree_add_item(bfcp_tree, hf_bfcp_version, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(bfcp_tree, hf_bfcp_hdr_r_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(bfcp_tree, hf_bfcp_hdr_f_bit, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
proto_tree_add_item(bfcp_tree, hf_bfcp_primitive, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
proto_tree_add_item(bfcp_tree, hf_bfcp_payload_length, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
proto_tree_add_item(bfcp_tree, hf_bfcp_conference_id, tvb, offset, 4, ENC_BIG_ENDIAN);
offset+=4;
proto_tree_add_item(bfcp_tree, hf_bfcp_transaction_id, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
proto_tree_add_item(bfcp_tree, hf_bfcp_user_id, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
bfcp_payload_length = tvb_get_ntohs(tvb,
BFCP_OFFSET_PAYLOAD_LENGTH) * 4;
/*offset = */dissect_bfcp_attributes(tvb, pinfo, bfcp_tree, offset, bfcp_payload_length);
} /* if(tree) */
}
