static int
dissect_bt_dht(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
col_set_str(pinfo->cinfo, COL_PROTOCOL, "BT-DHT");
col_clear(pinfo->cinfo, COL_INFO);
return dissect_bencoded_dict(tvb, pinfo, tree, 0, "BT-DHT Protocol" );
}
/* dissect a bencoded list from tvb, start at offset. it's like "lXXXe", "X" is any bencoded thing */
static int
dissect_bencoded_list(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint offset, char *label )
{
proto_item *ti;
proto_tree *sub_tree;
guint one_byte;
char *result;
ti = proto_tree_add_none_format( tree, hf_bencoded_list, tvb, offset, 0, "%s: list...", label );
sub_tree = proto_item_add_subtree( ti, ett_bencoded_list);
/* skip the 'l' */
offset += 1;
while( (one_byte=tvb_get_guint8(tvb,offset)) != 'e' )
{
switch( one_byte )
{
/* a integer */
case 'i':
offset = dissect_bencoded_int( tvb, pinfo, sub_tree, offset, &result, "Integer" );
break;
/* a sub-list */
case 'l':
offset = dissect_bencoded_list( tvb, pinfo, sub_tree, offset, "Sub-list" );
break;
/* a dictionary */
case 'd':
offset = dissect_bencoded_dict( tvb, pinfo, sub_tree, offset, "Sub-dict" );
break;
/* a string */
default:
offset = dissect_bencoded_string( tvb, pinfo, sub_tree, offset, &result, FALSE, "String" );
break;
}
}
offset += 1;
return offset;
}
static int
dissect_bencoded_dict_entry(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint offset )
{
proto_item *ti;
proto_tree *sub_tree;
gboolean tohex;
char *key, *val;
guint orig_offset = offset;
key = NULL;
val = NULL;
ti = proto_tree_add_item( tree, hf_bencoded_dict_entry, tvb, offset, 0, ENC_NA );
sub_tree = proto_item_add_subtree( ti, ett_bencoded_dict_entry);
/* dissect the key, it must be a string */
offset = dissect_bencoded_string( tvb, pinfo, sub_tree, offset, &key, FALSE, "Key" );
/* If it is a dict, then just do recursion */
switch( tvb_get_guint8(tvb,offset) )
{
case 'd':
offset = dissect_bencoded_dict( tvb, pinfo, sub_tree, offset, "Value" );
val = (char*)dict_str;
break;
case 'l':
if( strcmp(key,"e")==0 )
offset = dissect_bt_dht_error( tvb, pinfo, sub_tree, offset, &val, "Value" );
else if( strcmp(key,"values")==0 )
offset = dissect_bt_dht_values( tvb, pinfo, sub_tree, offset, &val, "Value" );
/* other unfamiliar lists */
else
{
offset = dissect_bencoded_list( tvb, pinfo, sub_tree, offset, "Value" );
val = (char*)list_str;
}
break;
case 'i':
offset = dissect_bencoded_int( tvb, pinfo, sub_tree, offset, &val, "Value" );
break;
/* it's a string */
default:
/* special process */
if( strcmp(key,"nodes")==0 )
offset = dissect_bt_dht_nodes( tvb, pinfo, sub_tree, offset, &val, "Value" );
/* some need to return hex string */
else
{
tohex = strcmp(key,"id")==0 || strcmp(key,"target")==0
|| strcmp(key,"info_hash")==0 || strcmp(key,"t")==0
|| strcmp(key,"v")==0;
offset = dissect_bencoded_string( tvb, pinfo, sub_tree, offset, &val, tohex, "Value" );
}
}
if( strlen(key)==1 )
key = (char*)val_to_str( key[0], short_key_name_value_string, key );
if( strlen(val)==1 )
val = (char*)val_to_str( val[0], short_val_name_value_string, val );
proto_item_set_text( ti, "%s: %s", key, val );
proto_item_set_len( ti, offset-orig_offset );
if( strcmp(key,"message_type")==0 || strcmp(key,"request_type")==0 )
col_append_fstr(pinfo->cinfo, COL_INFO, "%s=%s ", key, val);
return offset;
}
static int
dissect_bencoded_dict_entry(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint offset )
{
proto_item *ti;
proto_tree *sub_tree;
gboolean tohex;
const char *key;
const char *val;
guint orig_offset = offset;
key = NULL;
val = NULL;
ti = proto_tree_add_item( tree, hf_bencoded_dict_entry, tvb, offset, 0, ENC_NA );
sub_tree = proto_item_add_subtree( ti, ett_bencoded_dict_entry);
/* dissect the key, it must be a string */
offset = dissect_bencoded_string( tvb, pinfo, sub_tree, offset, &key, FALSE, "Key" );
/* If it is a dict, then just do recursion */
switch( tvb_get_guint8(tvb,offset) )
{
case 'd':
offset = dissect_bencoded_dict( tvb, pinfo, sub_tree, offset, "Value" );
val = dict_str;
break;
case 'l':
if( strcmp(key,"e")==0 )
offset = dissect_bt_dht_error( tvb, pinfo, sub_tree, offset, &val, "Value" );
else if( strcmp(key,"values")==0 )
offset = dissect_bt_dht_values( tvb, pinfo, sub_tree, offset, &val, "Value" );
/* other unfamiliar lists */
else
{
offset = dissect_bencoded_list( tvb, pinfo, sub_tree, offset, "Value" );
val = list_str;
}
break;
case 'i':
offset = dissect_bencoded_int( tvb, pinfo, sub_tree, offset, &val, "Value" );
break;
/* it's a string */
default:
/* special process */
if( strcmp(key,"nodes")==0 )
{
offset = dissect_bt_dht_nodes( tvb, pinfo, sub_tree, offset, &val, "Value" );
}
else if( strcmp(key,"ip")==0 )
{
/*
* Not found in BEP 0005 but explained by
* http://www.rasterbar.com/products/libtorrent/dht_sec.html
*/
int len, old_offset;
old_offset = offset;
len = bencoded_string_length(tvb, &offset);
if(len == 4) {
proto_tree_add_item(sub_tree, hf_ip, tvb, offset, len, ENC_BIG_ENDIAN);
val = tvb_ip_to_str(tvb, offset);
offset += len;
}
else {
offset = dissect_bencoded_string( tvb, pinfo, sub_tree, old_offset, &val, TRUE, "Value" );
}
}
else
{
/* some need to return hex string */
tohex = strcmp(key,"id")==0 || strcmp(key,"target")==0
|| strcmp(key,"info_hash")==0 || strcmp(key,"t")==0
|| strcmp(key,"v")==0 || strcmp(key,"token")==0;
offset = dissect_bencoded_string( tvb, pinfo, sub_tree, offset, &val, tohex, "Value" );
}
}
if( strlen(key)==1 )
key = val_to_str_const( key[0], short_key_name_value_string, key );
if( strlen(val)==1 )
val = val_to_str_const( val[0], short_val_name_value_string, val );
proto_item_set_text( ti, "%s: %s", key, val );
proto_item_set_len( ti, offset-orig_offset );
if( strcmp(key,"message_type")==0 || strcmp(key,"request_type")==0 )
col_append_fstr(pinfo->cinfo, COL_INFO, "%s=%s ", key, val);
return offset;
}
