packetforge: add packetforge for generic flow to extras

Add a new tool packetforge to extras. This tool is to support generic flow.
Packetforge is a library to translate naming or json profile format flow
pattern to the required input of generic flow, i.e. spec and mask. Using
python script flow_create.py, it can add and enable a new flow rule for
an interface via flow VAPI, and can delete an existed flow rule as well.
Command examples are shown below. Json profile examples can be found in
./parsegraph/samples.

Naming format input:
python flow_create.py --add -p "mac()/ipv4(src=1.1.1.1,dst=2.2.2.2)/udp()"
-a "redirect-to-queue 3" -i 1
python flow_create.py --del -i 1 -I 0

Json profile format input:
python flow_create.py -f "./flow_rule_examples/mac_ipv4.json" -i 1

With this command, flow rule can be added or deleted, and the flow
entry can be listed with "show flow entry" command in VPP CLI.

Packetforge is based on a parsegraph. The parsegraph can be built by
users. A Spec can be found in ./parsegraph as guidance. More details
about packetforge are in README file.

Type: feature

Signed-off-by: Ting Xu <ting.xu@intel.com>
Change-Id: Ia9f539741c5dca27ff236f2bcc493c5dd48c0df1

1 files changed, 48 insertions, 0 deletions

diff --git a/extras/packetforge/ProtocolHeaderField.py b/extras/packetforge/ProtocolHeaderField.py
new file mode 100644
index 00000000000..bcb88214931
--- /dev/null
+++ b/extras/packetforge/ProtocolHeaderField.py
@@ -0,0 +1,48 @@
+# Copyright (c) 2022 Intel and/or its affiliates.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import ExpressionConverter
+
+
+class ProtocolHeaderField:
+    def __init__(self, Size, Value, Mask, Field):
+        self.Size = Size
+        self.Value = Value
+        self.Mask = Mask
+        self.Field = Field
+
+    def UpdateValue(self, expression, auto):
+        if self.Field.IsReadonly and not auto:
+            return False
+
+        if expression != None:
+            ret, _ = ExpressionConverter.Verify(self.Field.Format, expression)
+            if not ret:
+                return False
+
+        self.Value = expression
+        return True
+
+    def UpdateMask(self, expression):
+        if expression != None:
+            ret, _ = ExpressionConverter.Verify(self.Field.Format, expression)
+            if not ret:
+                return False
+
+        self.Mask = expression
+        return True
+
+    def UpdateSize(self):
+        if self.Size:
+            return
+        self.Size = self.Field.Size