snort: support multiple instances per interface

Implements load balancing between snort instances via flow hash.
New CLI commands have been made to support these changes:

snort attach instance <name1>
    [instance <name2> ... ] interface <ifname> [input|output|inout]
snort attach all-instances interface <ifname> [input|output|inout]
snort detach instance <name1> interface <ifname>
snort detach all-instances interface <ifname>

The output of "show snort interfaces" has an extra column to show the
direction of each attachment:

interface   instances   direction
Ethernet0:  snort1      inout
            snort2      inout
            snort3      inout
Ethernet1:  snort1      input
            snort3      output

To maintain backwards compatibility for the snort api, the
snort_interface_get api endpoint only returns one of the attached
instances and the snort_interface_detach endpoint detaches all
attached instances.

Type: improvement
Signed-off-by: Agathiyan Bragadeesh <agathiyan.bragadeesh2@arm.com>
Change-Id: I6b7c26c203496d6a1dba244620907f28c04bb478

1 files changed, 23 insertions, 15 deletions

diff --git a/test/test_snort.py b/test/test_snort.py
index 19401cb7b85..c25c0e65145 100644
--- a/test/test_snort.py
+++ b/test/test_snort.py
@@ -12,10 +12,10 @@ class TestSnort(VppTestCase):
     def setUpClass(cls):
         super(TestSnort, cls).setUpClass()
         try:
-            cls.create_pg_interfaces(range(2))
+            cls.create_pg_interfaces(range(4))
             for i in cls.pg_interfaces:
                 i.config_ip4().resolve_arp()
-                i.admin_up()
+                i.admin_down()
         except Exception:
             cls.tearDownClass()
             raise
@@ -24,7 +24,6 @@ class TestSnort(VppTestCase):
     def tearDownClass(cls):
         for i in cls.pg_interfaces:
             i.unconfig_ip4()
-            i.admin_down()
         super(TestSnort, cls).tearDownClass()
 
     def test_snort_cli(self):
@@ -36,14 +35,18 @@ class TestSnort(VppTestCase):
             "snort create-instance name snortTest2 queue-size 16 on-disconnect pass": "",
             "snort attach instance snortTest interface pg0 output": "",
             "snort attach instance snortTest2 interface pg1 input": "",
+            "snort attach all-instances interface pg2 inout": "",
+            "snort attach instance snortTest instance snortTest2 interface pg3 inout": "",
             "show snort instances": "snortTest",
             "show snort interfaces": "pg0",
             "show snort clients": "number of clients",
             "show snort mode": "input mode: interrupt",
             "snort mode polling": "",
             "snort mode interrupt": "",
-            "snort detach interface pg0": "",
-            "snort detach interface pg1": "",
+            "snort detach instance snortTest interface pg0": "",
+            "snort detach instance snortTest2 interface pg1": "",
+            "snort detach all-instances interface pg2": "",
+            "snort detach instance snortTest instance snortTest2 interface pg3": "",
             "snort delete instance snortTest": "",
         }
 
@@ -64,7 +67,7 @@ class TestSnortVapi(VppTestCase):
             for i in cls.pg_interfaces:
                 i.config_ip4()
                 i.resolve_arp()
-                i.admin_up()
+                i.admin_down()
         except Exception:
             cls.tearDownClass()
             raise
@@ -73,7 +76,6 @@ class TestSnortVapi(VppTestCase):
     def tearDownClass(cls):
         for i in cls.pg_interfaces:
             i.unconfig_ip4()
-            i.admin_down()
         super(TestSnortVapi, cls).tearDownClass()
 
     def test_snort_01_modes_set_interrupt(self):
@@ -109,20 +111,27 @@ class TestSnortVapi(VppTestCase):
         reply = self.vapi.snort_interface_attach(
             instance_index=0, sw_if_index=1, snort_dir=1
         )
+        reply = self.vapi.snort_interface_attach(
+            instance_index=0, sw_if_index=2, snort_dir=2
+        )
+        reply = self.vapi.snort_interface_attach(
+            instance_index=1, sw_if_index=2, snort_dir=3
+        )
+        reply = self.vapi.cli("show snort interfaces")
+        self.assertIn("snortTest0", reply)
+        self.assertIn("snortTest1", reply)
+        self.assertIn("input", reply)
+        self.assertIn("inout", reply)
+        self.assertIn("output", reply)
         try:
             reply = self.vapi.snort_interface_attach(
-                instance_index=1, sw_if_index=1, snort_dir=1
+                instance_index=1, sw_if_index=2, snort_dir=2
             )
         except:
             pass
         else:
             self.assertNotEqual(reply.retval, 0)
-
-        reply = self.vapi.snort_interface_attach(
-            instance_index=1, sw_if_index=2, snort_dir=3
-        )
         reply = self.vapi.cli("show snort interfaces")
-        self.assertIn("snortTest0", reply)
         self.assertIn("snortTest1", reply)
 
     def test_snort_05_delete_instance(self):
@@ -131,14 +140,13 @@ class TestSnortVapi(VppTestCase):
         reply = self.vapi.cli("show snort interfaces")
         self.assertNotIn("snortTest0", reply)
         self.assertIn("snortTest1", reply)
-        reply = self.vapi.cli("show snort interfaces")
         self.assertNotIn("pg0", reply)
         self.assertIn("pg1", reply)
 
     def test_snort_06_detach_if(self):
         """Interfaces can be detached"""
         try:
-            reply = self.vapi.snort_interface_detach(sw_if_index=1)
+            reply = self.vapi.snort_interface_detach(sw_if_index=3)
         except:
             pass
         else: