From da9544a4dba273d1cada460f3064d9e1ff21b44e Mon Sep 17 00:00:00 2001
From: Andreas Lindhé <andreas@lindhe.io>
Date: Wed, 11 Oct 2017 08:47:50 +0200
Subject: Move files from bro-script directory

---
 broccoli/script/README           |  9 ++++
 broccoli/script/pasad-parsed.bro | 96 ++++++++++++++++++++++++++++++++++++++++
 broccoli/script/pasad-simple.bro | 56 +++++++++++++++++++++++
 3 files changed, 161 insertions(+)
 create mode 100644 broccoli/script/README
 create mode 100644 broccoli/script/pasad-parsed.bro
 create mode 100644 broccoli/script/pasad-simple.bro

(limited to 'broccoli')

diff --git a/broccoli/script/README b/broccoli/script/README
new file mode 100644
index 0000000..15f121e
--- /dev/null
+++ b/broccoli/script/README
@@ -0,0 +1,9 @@
+This directory contains a baseline implementation of the package parser
+implemented as a Bro script.  A .bro file contains a script that can be
+executed on a Modbus pcap dump.  A .log file contains an example for an
+output file generated by this script.  By convention, the sample log file
+should contain the first 100 lines of a real log file obtained from running
+the script on packets_00014_20161128135616.cap.
+
+Currently, the scripts only handle the read_holding_registers event.  Other
+events can handled by simply copying and adapting the existing handlers.
diff --git a/broccoli/script/pasad-parsed.bro b/broccoli/script/pasad-parsed.bro
new file mode 100644
index 0000000..88b1be1
--- /dev/null
+++ b/broccoli/script/pasad-parsed.bro
@@ -0,0 +1,96 @@
+## Implementation that outputs the register identification and the register
+## value. The correct register count is not checked and might lead to indexing
+## errors.
+
+module Pasad;
+
+## DATA STRUCTURES
+
+export {
+	redef enum Log::ID += { LOG };
+
+	type Transaction: record {
+		start_address:	count;
+		quantity:	count;
+	};
+
+	type TransactionTable: table[count] of Transaction;
+
+	type Info: record {
+		transactions:	TransactionTable	&default=TransactionTable();
+	};
+
+	type Entry: record {
+		ip:		addr	&log;
+		uid:		count	&log;
+		regtype:	string	&log;
+		address:	count	&log;
+		register:	count	&log;
+	};
+}
+
+redef record connection += {
+	pasad: Info	&default=Info();
+};
+
+## CUSTOM EVENTS
+
+event pasad_entry(entry: Entry)
+	{
+	Log::write(Pasad::LOG, entry);
+	}
+
+event pasad_unmatched(tid: count)
+	{
+	print fmt("Unmatched response: tid=%d", tid);
+	}
+
+## CUSTOM FUNCTIONS
+
+function pasad_generate_events(transaction: Transaction, c: connection, headers: ModbusHeaders, registers: ModbusRegisters, regtype: string)
+	{
+	# TODO: check registers size
+	local i = 0;
+	while ( i < transaction$quantity )
+		{
+		local entry  = Entry(
+			$ip=c$id$orig_h,
+			$uid=headers$uid,
+			$regtype=regtype,
+			$address=transaction$start_address + i,
+			$register=registers[i]
+		);
+		event pasad_entry(entry);
+		++i;
+		}
+	}
+
+## EVENT HANDLERS
+
+event bro_init() &priority=5
+	{
+	Log::create_stream(Pasad::LOG, [$columns=Entry, $path="pasad-parsed"]);
+	}
+
+event modbus_read_holding_registers_request(c: connection, headers: ModbusHeaders, start_address: count, quantity: count)
+	{
+	local tid = headers$tid;
+	local transaction = Transaction(
+		$start_address=start_address,
+		$quantity=quantity
+	);
+	c$pasad$transactions[tid] = transaction;
+	}
+
+event modbus_read_holding_registers_response(c: connection, headers: ModbusHeaders, registers: ModbusRegisters)
+	{
+	local tid = headers$tid;
+	if ( tid !in c$pasad$transactions )
+		{
+		event pasad_unmatched(tid);
+		return;
+		}
+	local transaction = c$pasad$transactions[tid];
+	delete c$pasad$transactions[tid];
+	pasad_generate_events(transaction, c, headers, registers, "h");
+	}
diff --git a/broccoli/script/pasad-simple.bro b/broccoli/script/pasad-simple.bro
new file mode 100644
index 0000000..db3b4be
--- /dev/null
+++ b/broccoli/script/pasad-simple.bro
@@ -0,0 +1,56 @@
+## Simple implementation that outputs the raw request and response data 
+## to a log file.
+## Currently, this only handles the read_holding_registers event.  Other
+## events can be handled similarily.  This implementation assumes that
+## requests and responses are exchanged within the same connection.  I am not
+## sure whether this really holds.
+
+module Pasad;
+
+export {
+	redef enum Log::ID += { LOG };
+
+	type Info: record {
+		ts_request:	time	&log;
+		ts_response:	time	&log &optional;
+		rtype: 		string	&log;
+		tid_request:	count	&log;
+		tid_response:	count	&log &optional;
+		ip_orig:	addr	&log;
+		ip_resp:	addr	&log;
+		start_address:	count	&log;
+		quantity:	count	&log;
+		registers:	ModbusRegisters &log &optional;
+	};
+}
+
+redef record connection += {
+	pasad: Info &optional;
+};
+
+event bro_init() &priority=5
+	{
+	Log::create_stream(Pasad::LOG, [$columns=Info, $path="pasad-simple"]);
+	}
+
+event modbus_read_holding_registers_request(c: connection, headers: ModbusHeaders, start_address: count, quantity: count)
+	{
+	local rec: Info = [
+		$ts_request=network_time(),
+		$rtype="holding",
+		$tid_request=headers$tid,
+		$start_address=start_address,
+		$quantity=quantity,
+		$ip_orig=c$id$orig_h,
+		$ip_resp=c$id$resp_h
+	];
+	c$pasad = rec;
+	}
+
+event modbus_read_holding_registers_response(c: connection, headers: ModbusHeaders, registers: ModbusRegisters)
+	{
+		c$pasad$tid_response = headers$tid;
+		c$pasad$ts_response = network_time();
+		c$pasad$registers = registers;
+		Log::write(Pasad::LOG, c$pasad);
+	}
-- 
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