zeek/src/analyzer/protocol/tcp/functions.bif
2020-04-07 16:08:34 -07:00

139 lines
4.5 KiB
C++

%%{
#include "File.h"
#include "Sessions.h"
#include "Reporter.h"
#include "analyzer/protocol/tcp/TCP.h"
%%}
## Get the originator sequence number of a TCP connection. Sequence numbers
## are absolute (i.e., they reflect the values seen directly in packet headers;
## they are not relative to the beginning of the connection).
##
## cid: The connection ID.
##
## Returns: The highest sequence number sent by a connection's originator, or 0
## if *cid* does not point to an active TCP connection.
##
## .. zeek:see:: get_resp_seq
function get_orig_seq%(cid: conn_id%): count
%{
Connection* c = sessions->FindConnection(cid);
if ( ! c )
return val_mgr->GetCount(0);
if ( c->ConnTransport() != TRANSPORT_TCP )
return val_mgr->GetCount(0);
analyzer::Analyzer* tc = c->FindAnalyzer("TCP");
if ( tc )
return val_mgr->GetCount(static_cast<analyzer::tcp::TCP_Analyzer*>(tc)->OrigSeq());
else
{
reporter->Error("connection does not have TCP analyzer");
return val_mgr->GetCount(0);
}
%}
## Get the responder sequence number of a TCP connection. Sequence numbers
## are absolute (i.e., they reflect the values seen directly in packet headers;
## they are not relative to the beginning of the connection).
##
## cid: The connection ID.
##
## Returns: The highest sequence number sent by a connection's responder, or 0
## if *cid* does not point to an active TCP connection.
##
## .. zeek:see:: get_orig_seq
function get_resp_seq%(cid: conn_id%): count
%{
Connection* c = sessions->FindConnection(cid);
if ( ! c )
return val_mgr->GetCount(0);
if ( c->ConnTransport() != TRANSPORT_TCP )
return val_mgr->GetCount(0);
analyzer::Analyzer* tc = c->FindAnalyzer("TCP");
if ( tc )
return val_mgr->GetCount(static_cast<analyzer::tcp::TCP_Analyzer*>(tc)->RespSeq());
else
{
reporter->Error("connection does not have TCP analyzer");
return val_mgr->GetCount(0);
}
%}
## Associates a file handle with a connection for writing TCP byte stream
## contents.
##
## cid: The connection ID.
##
## direction: Controls what sides of the connection to record. The argument can
## take one of the four values:
##
## - ``CONTENTS_NONE``: Stop recording the connection's content.
## - ``CONTENTS_ORIG``: Record the data sent by the connection
## originator (often the client).
## - ``CONTENTS_RESP``: Record the data sent by the connection
## responder (often the server).
## - ``CONTENTS_BOTH``: Record the data sent in both directions.
## Results in the two directions being intermixed in the file,
## in the order the data was seen by Zeek.
##
## f: The file handle of the file to write the contents to.
##
## Returns: Returns false if *cid* does not point to an active connection, and
## true otherwise.
##
## .. note::
##
## The data recorded to the file reflects the byte stream, not the
## contents of individual packets. Reordering and duplicates are
## removed. If any data is missing, the recording stops at the
## missing data; this can happen, e.g., due to an
## :zeek:id:`content_gap` event.
##
## .. zeek:see:: get_contents_file set_record_packets contents_file_write_failure
function set_contents_file%(cid: conn_id, direction: count, f: file%): bool
%{
Connection* c = sessions->FindConnection(cid);
if ( ! c )
return val_mgr->GetFalse();
c->GetRootAnalyzer()->SetContentsFile(direction, f);
return val_mgr->GetTrue();
%}
## Returns the file handle of the contents file of a connection.
##
## cid: The connection ID.
##
## direction: Controls what sides of the connection to record. See
## :zeek:id:`set_contents_file` for possible values.
##
## Returns: The :zeek:type:`file` handle for the contents file of the
## connection identified by *cid*. If the connection exists
## but there is no contents file for *direction*, then the function
## generates an error and returns a file handle to ``stderr``.
##
## .. zeek:see:: set_contents_file set_record_packets contents_file_write_failure
function get_contents_file%(cid: conn_id, direction: count%): file
%{
Connection* c = sessions->FindConnection(cid);
BroFile* f = c ? c->GetRootAnalyzer()->GetContentsFile(direction) : nullptr;
if ( f )
{
Ref(f);
return new Val(f);
}
// Return some sort of error value.
if ( ! c )
builtin_error("unknown connection id in get_contents_file()", cid);
else
builtin_error("no contents file for given direction");
return new Val(new BroFile(stderr, "-", "w"));
%}