I took a look at Packet-sccp.c, however i'm still a bit confused.
/* Reasemble */
if (!sccp_xudt_desegment) { ******** how does sccp_xudt_desegment change?
proto_tree_add_text(sccp_tree, tvb, variable_pointer1,
tvb_get_guint8(tvb, variable_pointer1)+1,
"Segmented Data");
dissect_sccp_variable_parameter(tvb, pinfo, sccp_tree, tree,
PARAMETER_DATA, variable_pointer1);
******Does this just dissect an unknown message? where does it change that it should be reassembled? ******
} else {
save_fragmented = pinfo->fragmented;
pinfo->fragmented = TRUE; ***i thought this was a way to tell if it needs to be reassembled, not after you already know and are reassembling*****
frag_msg = fragment_add_seq_next(tvb, variable_pointer1 + 1, pinfo,
source_local_ref, /* ID for fragments belonging together */
sccp_xudt_msg_fragment_table, /* list of message fragments */
sccp_xudt_msg_reassembled_table, /* list of reassembled messages */
tvb_get_guint8(tvb,variable_pointer1),/* fragment length - to the end */
more); /* More fragments? */
new_tvb = process_reassembled_data(tvb, variable_pointer1 + 1, pinfo,
"Reassembled Message", frag_msg,
&sccp_xudt_msg_frag_items, NULL,
tree);
if (frag_msg && frag_msg->next) { /* Reassembled */ *****what is frag_msg-> next?*****
if (check_col(pinfo->cinfo, COL_INFO))
col_append_str(pinfo->cinfo, COL_INFO,
"(Message reassembled) ");
} else if (more) { /* Not last packet of reassembled message */
if (check_col(pinfo->cinfo, COL_INFO))
col_append_str(pinfo->cinfo, COL_INFO, "(Message fragment) ");
}
pinfo->fragmented = save_fragmented; ***why do we change this back? ***
if (new_tvb)
dissect_sccp_data_param(new_tvb, pinfo, tree);
}
/* End reassemble */
Among other things, i dont understand how you first know its fragmented since it seems to me the initial if( ) param doesnt get changed.
Greg
