From b5d2ac8df7680ff37232a639d2ffa8f6e42bc0d7 Mon Sep 17 00:00:00 2001
From: SUGYO <sugyo@pb.jp.nec.com>
Date: Thu, 18 Jul 2013 15:34:45 +0900
Subject: [PATCH] correct ExactMatch (issue #53)

---
 ruby/trema/exact-match.rb |  2 +-
 ruby/trema/match.c        | 61 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/ruby/trema/exact-match.rb b/ruby/trema/exact-match.rb
index fbc172f4..72844410 100644
--- a/ruby/trema/exact-match.rb
+++ b/ruby/trema/exact-match.rb
@@ -21,7 +21,7 @@
 module Trema
   class ExactMatch
     def self.from message
-      message.match
+      Match.from message
     end
   end
 end
diff --git a/ruby/trema/match.c b/ruby/trema/match.c
index f033205d..806d5f5a 100644
--- a/ruby/trema/match.c
+++ b/ruby/trema/match.c
@@ -25,10 +25,71 @@ extern VALUE mTrema;
 VALUE cMatch;
 
 
+/*
+ * Creates a {Match} instance from packet_in's data.
+ *
+ * @overload match_from(message)
+ *
+ *   @example
+ *     def packet_in datapath_id, message
+ *       send_flow_mod(
+ *         datapath_id,
+ *         :match => Match.from( message ),
+ *         :actions => Trema::ActionOutput.new( 2 )
+ *       )
+ *     end
+ *
+ *   @param [PacketIn] message
+ *     the {PacketIn}'s message content.
+ *
+ * @return [Match] self
+ *   the match from packet_in's data.
+ */
+static VALUE
+match_from( VALUE self, VALUE message ) {
+  uint32_t in_port = OFPP_CONTROLLER;
+  VALUE r_match = rb_iv_get( message, "@match" );
+  if ( !NIL_P( r_match ) ) {
+    VALUE r_in_port = rb_iv_get( r_match, "@in_port" );
+    if ( !NIL_P( r_in_port ) ) {
+      in_port = NUM2UINT( r_in_port );
+      if ( in_port == 0 ) {
+        rb_raise( rb_eArgError, "The in_port value must be greater than 0." );
+      }
+      if ( in_port > OFPP_MAX ) {
+        if ( in_port != OFPP_CONTROLLER && in_port != OFPP_LOCAL ) {
+          rb_raise( rb_eArgError, "The in_port value must be less than or equal to OFPP_MAX." );
+        }
+      }
+    }
+  }
+
+  VALUE r_data = rb_iv_get( message, "@data" );
+  if ( NIL_P( r_data ) ) {
+    rb_raise( rb_eArgError, "The data is a mandatory option" );
+  }
+  buffer *data = r_array_to_buffer( r_data );
+  bool ret = parse_packet( data );
+  if ( !ret ) {
+    rb_raise( rb_eArgError, "The data must be a Ethernet frame." );
+  }
+
+  oxm_matches *matches = create_oxm_matches();
+  set_match_from_packet( matches, in_port, NULL, data );
+  VALUE r_new = oxm_match_to_r_match( matches );
+  delete_oxm_matches( matches );
+
+  free_buffer( data );
+
+  return r_new;
+}
+
+
 void
 Init_match( void ) {
   cMatch = rb_define_class_under( mTrema, "Match", rb_eval_string( "Trema::Message" ) );
   rb_require( "trema/match" );
+  rb_define_singleton_method( cMatch, "from", match_from, 1 );
 }