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

extras/packetforge/Edge.py

@@ -0,0 +1,92 @@
+# 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.
+
+from EdgeAction import *
+import json
+
+
+class Edge:
+    def __init__(self):
+        self.JSON = None
+        self.Start = None
+        self.End = None
+        self.actionList = []
+
+    def Create(jsonfile):
+        f = open(jsonfile, "r", encoding="utf-8")
+        token = json.load(f)
+
+        if token == None:
+            return None
+
+        if token["type"] != "edge":
+            return None
+
+        edgeList = []
+
+        startNodes = token["start"]
+        endNodes = token["end"]
+
+        if startNodes == None or endNodes == None:
+            return None
+
+        startTokens = startNodes.split(",")
+        endTokens = endNodes.split(",")
+
+        for start in startTokens:
+            for end in endTokens:
+
+                edge = Edge()
+
+                edge.Start = start
+                edge.End = end
+
+                if "actions" in token:
+                    for at in token["actions"]:
+                        action = EdgeAction.Create(at)
+                        if not action:
+                            return None
+
+                        edge.actionList.append(action)
+
+                edge.JSON = jsonfile
+                edgeList.append(edge)
+
+        return edgeList
+
+    def Apply(self, first, second):
+        exp = []
+
+        for i in range(len(self.actionList)):
+            act = self.actionList[i]
+
+            if act.FromStartObject == True:
+                exp.append(first.GetValue(act.FromExpression))
+            elif act.FromStartObject == False:
+                exp.append(second.GetValue(act.FromExpression))
+            else:
+                exp.append(act.FromExpression)
+
+        for i in range(len(exp)):
+            act = self.actionList[i]
+
+            if act.ToStartObject:
+                first.SetFieldAuto(act.ToExpression, exp[i])
+            else:
+                second.SetFieldAuto(act.ToExpression, exp[i])
+
+    def Actions(self):
+        return self.actionList
+
+    def Name(self):
+        return self.Start + "_" + self.End