session: add Source Deny List

With this feature, session enable is now modified to have 3 modes of operation
session enable -- only enable session
session enable rt-backend sdl -- enable session with sdl
session enable rt-backend rule-table -- enable session with rule-table

session rule tables are now created on demand, upon adding first rule
to the rule table.

refactor session table to remove depenency from sesssion rules table. Now
session rules table APIs take srtg_handle and transport
proto instead of srt pointer.

Type: feature

Change-Id: Idde6a9b2f46b29bb931f9039636562575572aa14
Signed-off-by: Steven Luong <sluong@cisco.com>
diff --git a/test/asf/vpp_session_sdl.py b/test/asf/vpp_session_sdl.py
new file mode 100644
index 0000000..b10c11d
--- /dev/null
+++ b/test/asf/vpp_session_sdl.py
@@ -0,0 +1,75 @@
+from ipaddress import IPv4Network
+
+from vpp_object import VppObject
+from vpp_papi import VppEnum
+from vpp_ip import INVALID_INDEX
+from vpp_papi_provider import UnexpectedApiReturnValueError
+
+
+class SessionSdl:
+    """Session SDL"""
+
+    def __init__(
+        self,
+        lcl,
+        action_index,
+        tag,
+    ):
+
+        self.action_index = action_index
+        self.lcl = lcl
+        self.tag = tag
+
+    def encode(self):
+        return {
+            "lcl": self.lcl,
+            "action_index": self.action_index,
+            "tag": self.tag,
+        }
+
+
+class VppSessionSdl(VppObject):
+    """VPP Session SDL"""
+
+    def __init__(self, test, rules, is_add, appns_index):
+        self._test = test
+        self._rules = rules
+        self.is_add = is_add
+        self.appns_index = appns_index
+
+    @property
+    def rules(self):
+        return self._rules
+
+    @property
+    def count(self):
+        return len(self._rules)
+
+    def encode_rules(self):
+        rules = []
+        for rule in self._rules:
+            rules.append(rule.encode())
+        return rules
+
+    def add_vpp_config(self, expect_error=False):
+        try:
+            reply = self._test.vapi.session_sdl_add_del(
+                is_add=self.is_add,
+                appns_index=self.appns_index,
+                count=self.count,
+                r=self.encode_rules(),
+            )
+            self._test.registry.register(self, self._test.logger)
+            if expect_error:
+                self._test.fail("Unexpected api reply")
+            return self
+        except UnexpectedApiReturnValueError:
+            if not expect_error:
+                self._test.fail("Unexpected api reply")
+        return None
+
+    def query_vpp_config(self):
+        pass
+
+    def remove_vpp_config(self, expect_error=False):
+        pass