Add hello13_version_bitmap.raw parser.

trema · Apr 7, 2015 · f6c5533 · f6c5533
1 parent 9ecd4f1
commit f6c5533
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Showing 2 changed files with 64 additions and 11 deletions.
diff --git a/features/hello13_read.feature b/features/hello13_read.feature
@@ -4,11 +4,25 @@ Feature: Pio::Hello13.read
     When I try to parse the file with "Hello13" class
     Then it should finish successfully
     And the parsed data have the following field and value:
-      | field          |        value |
-      | class          | Pio::Hello13 |
-      | ofp_version    |            4 |
-      | message_type   |            0 |
-      | message_length |            8 |
-      | transaction_id |            0 |
-      | xid            |            0 |
-      | elements       |           [] |
+      | field              |        value |
+      | class              | Pio::Hello13 |
+      | ofp_version        |            4 |
+      | message_type       |            0 |
+      | message_length     |            8 |
+      | transaction_id     |            0 |
+      | xid                |            0 |
+      | supported_versions |           [] |
+
+  Scenario: hello13_version_bitmap.raw
+    Given a packet data file "hello13_version_bitmap.raw"
+    When I try to parse the file with "Hello13" class
+    Then it should finish successfully
+    And the parsed data have the following field and value:
+      | field              |                        value |
+      | class              |                 Pio::Hello13 |
+      | ofp_version        |                            4 |
+      | message_type       |                            0 |
+      | message_length     |                           16 |
+      | transaction_id     |                            0 |
+      | xid                |                            0 |
+      | supported_versions | [:open_flow10, :open_flow13] |
diff --git a/lib/pio/hello13.rb b/lib/pio/hello13.rb
@@ -1,8 +1,26 @@
 require 'bindata'
 
 module Pio
-  # OpenFlow 1.3 Hello Element
+  # ofp_hello_elem_header and value
   class HelloElement < BinData::Record
+    endian :big
+
+    uint16 :element_type
+    uint16 :element_length
+    choice :element_value, selection: :chooser do
+      string 'unknown', read_length: -> { element_length - 4 }
+      uint32 'version_bitmap'
+    end
+
+    def version_bitmap?
+      element_type == 1
+    end
+
+    private
+
+    def chooser
+      version_bitmap? ? 'version_bitmap' : 'unknown'
+    end
   end
 
   # OpenFlow 1.3 Hello message
@@ -11,14 +29,35 @@ class Hello13 < BinData::Record
 
     uint8 :ofp_version, initial_value: 4
     uint8 :message_type
-    uint16 :message_length, value: 8
+    uint16 :message_length, initial_value: 8
     uint32 :transaction_id
-    array :elements, type: :hello_element, length: 0
+    array :elements,
+          type: :hello_element,
+          read_until: :eof
 
     def xid
       transaction_id
     end
 
+    def supported_versions
+      supported_versions_list.map do |each|
+        "open_flow1#{each - 1}".to_sym
+      end
+    end
+
     alias_method :to_binary, :to_binary_s
+
+    private
+
+    def supported_versions_list
+      (1..32).each_with_object([]) do |each, result|
+        result << each if (version_bitmap >> each & 1) == 1
+      end
+    end
+
+    def version_bitmap
+      bitmap = elements.select(&:version_bitmap?).first
+      bitmap ? bitmap.element_value : 0
+    end
   end
 end