From a831a2a80b54d428031e64c37321003c7157bd56 Mon Sep 17 00:00:00 2001
From: Harald Welte <laforge@gnumonks.org>
Date: Fri, 9 Jul 2010 09:20:42 +0200
Subject: [PATCH] initial commit of tool to generate ladder diagrams

---
 Makefile      |  16 ++++++
 gen_ladder.pl | 156 ++++++++++++++++++++++++++++++++++++++++++++++++++
 test.lad      |  19 ++++++
 3 files changed, 191 insertions(+)
 create mode 100644 Makefile
 create mode 100755 gen_ladder.pl
 create mode 100644 test.lad

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..a02d73a
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,16 @@
+GL=./gen_ladder.pl
+DOT=dot
+
+default:
+
+%.dot:	%.lad
+	$(GL) $^ > $@
+
+%.ps:	%.dot
+	$(DOT) -Tps < $^ > $@
+
+%.svg:	%.dot
+	$(DOT) -Tsvg < $^ > $@
+
+clean:
+	rm *.dot *.ps *.svg
diff --git a/gen_ladder.pl b/gen_ladder.pl
new file mode 100755
index 0000000..d36b9e8
--- /dev/null
+++ b/gen_ladder.pl
@@ -0,0 +1,156 @@
+#!/usr/bin/perl -w
+use strict;
+
+# Script to generate Graphviz (.dot) based ladder diagrams for network
+# protocols
+#
+# (C) 2010 by Harald Welte <laforge@gnumonks.org>
+
+my $cfg_parse_state;
+my $cfg_parse_section;
+
+my %cfg_entities;
+my @cfg_entity_arr;
+my $cfg_nr_entities = 0;
+my @cfg_messages;
+
+# parse a line of the config file
+sub parse_cfg_line($)
+{
+	my $line = shift;
+
+	if ($line =~ /^\#/ ||
+	    $line =~ /^\s*$/) {
+		return;
+	}
+
+	#printf("sec=%s\n", $cfg_parse_section);
+	if ($line =~ /^\[/) {
+		($cfg_parse_section) = $line =~ /^\[(.*)\]/;
+		return;
+	}
+	if ($cfg_parse_section eq 'entities') {
+		my ($entity) = $line =~ /^(\w+)/;
+		$cfg_entities{$entity} = $cfg_nr_entities++;
+		push(@cfg_entity_arr, $entity);
+	} elsif ($cfg_parse_section eq 'messages') {
+		my ($src, $dst, $label, $flags) =
+				$line =~ /(\w+)\s+(\w+)\s+"(.*)"(.*)/;
+		my %msg;
+		$msg{'src'} = $src;
+		$msg{'dst'} = $dst;
+		$msg{'label'} = $label;
+		$msg{'flags'} = $flags;
+		# store a reference to the new hash on the global pile of
+		# message hash references
+		#print("$src $dst $label $flags\n");
+		push(@cfg_messages, \%msg);
+	}
+}
+
+# parse a line of the config file
+sub parse_cfg_file($)
+{
+	my $fname = shift;
+	open(INFILE, "<$fname");
+	while (my $line = <INFILE>) {
+		#print($line);
+		chomp($line);
+		parse_cfg_line($line);
+	}
+	close(INFILE);
+}
+
+# generate the nodes between which we will transfer messages
+sub gen_nodes()
+{
+	my $num_msgs = @cfg_messages;
+
+	foreach my $m (@cfg_entity_arr) {
+		printf("  %s [shape=none]\n", $m);
+	}
+	print("\n");
+
+	foreach my $m (@cfg_entity_arr) {
+		my $first = 0;
+		my $count;
+
+		# initial edge between header entity and the chain
+		printf("  %s -> %s0 [style=invis]\n", $m, $m);
+
+		# chain of edges between the individual nodes of one entity
+		for ($count = 0; $count < $num_msgs+1; $count++) {
+			my $name = sprintf("%s%u", $m, $count);
+			if ($first == 0) {
+				printf("  %s ", $name);
+			} else {
+				printf("-> %s ", $name);
+			}
+			$first = 1;
+		}
+		print(" [weight=1000]\n");
+	}
+	print("\n");
+
+	# invisible chain of edges between all entities
+	my $first = 1;
+	print("  { rank=same;\n    edge[style=invis]\n");
+	foreach my $e (@cfg_entity_arr) {
+		if ($first) {
+			printf("    %s0 ", $e);
+			$first = 0;
+		} else {
+			printf("-> %s0 ", $e);
+		}
+	}
+	print("\n  }\n");
+	print("\n");
+}
+
+sub entity_left_of($$)
+{
+	my $l = shift;
+	my $r = shift;
+	if ($cfg_entities{$l} < $cfg_entities{$r}) {
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
+# generate edges for the individual messages
+sub gen_edges()
+{
+	my $count = 1;
+	my $l; my $r; my $dir;
+
+	foreach my $m (@cfg_messages) {
+		if (entity_left_of($$m{'src'}, $$m{'dst'})) {
+			$l = $$m{'src'};
+			$r = $$m{'dst'};
+			$dir = 'forward';
+		} else {
+			$l = $$m{'dst'};
+			$r = $$m{'src'};
+			$dir = 'back';
+		}
+		print("  { rank=same;\n");
+		printf("    %s%u -> %s%u [dir=%s label=\"%s\"]\n  }\n",
+			$l, $count, $r, $count, $dir, $$m{'label'});
+		$count++;
+	}
+}
+
+parse_cfg_file($ARGV[0]);
+
+# print static header
+print("digraph ladder {\n");
+print("  node [shape=point]\n");
+print("  edge [dir=none]\n");
+
+# generate and print dynamic content
+gen_nodes();
+gen_edges();
+
+# print footer
+print("}\n");
diff --git a/test.lad b/test.lad
new file mode 100644
index 0000000..360b091
--- /dev/null
+++ b/test.lad
@@ -0,0 +1,19 @@
+[entities]
+# define the entities in the system (in order)
+ms
+bts
+bsc
+msc
+hlr
+
+[messages]
+# define the protocol messages in-order
+ms	bts	"L1 RACH burst"
+bts	bsc	"RSL CHAN RQD"
+bsc	bts	"RSL CHAN ACT REQ"
+bts	bsc	"RSL CHAN ACT ACK"
+bsc	bts	"RSL IMM ASS CMD"
+bts	ms	"IMMEDIATE ASSIGN"
+ms	bsc	"CM SERVICE REQUEST"
+bsc	msc	"COMPL L3 INFO (CM SERV REQ)"
+ms	msc	"Dedicated Channel" both dashed