stats: fix state counter removal

Avoid using vec_del1() for directory vector to keep indexes valid all
the time.

There are state counters for each slave in LACP bond mode which can be
dynamically created and removed. Vector index is used to access these
counters. But also vec_del1() is used to remove counter from vector.
This function changes the index of the last element, so after this we
are unable to access ex-last element using old index.

As a result it is not possible to add-del-add two interfaces to the LACP
bond:

DBGvpp# create bond mode lacp
BondEthernet0
DBGvpp# create packet-generator interface pg1
DBGvpp# create packet-generator interface pg2
DBGvpp# bond add BondEthernet0 pg1
DBGvpp# bond add BondEthernet0 pg2
DBGvpp# bond del pg1
DBGvpp# bond del pg2
DBGvpp# bond add BondEthernet0 pg1
DBGvpp# bond add BondEthernet0 pg2
bond add: /if/lacp/1/3/partner-state is already register

Type: fix

Signed-off-by: Vladimir Isaev <visaev@netgate.com>
Change-Id: I2c86e13905eefdef6233369cd4ab5c1b53d123bd
(cherry picked from commit 72e31bc2d9b910147c09e1c329713fccc873a018)

1 files changed, 41 insertions, 40 deletions

diff --git a/test/test_bond.py b/test/test_bond.py
index d1ae77ad3f5..7cdbc71c201 100644
--- a/test/test_bond.py
+++ b/test/test_bond.py
@@ -171,50 +171,51 @@ class TestBondInterface(VppTestCase):
     def test_bond_enslave(self):
         """ Bond enslave/detach slave test """
 
-        # create interface (BondEthernet0)
+        # create interface (BondEthernet0) and set bond mode to LACP
         self.logger.info("create bond")
-        bond0 = VppBondInterface(self, mode=3)
+        bond0 = VppBondInterface(self, mode=5)
         bond0.add_vpp_config()
         bond0.admin_up()
 
-        # verify pg0 and pg1 not in BondEthernet0
-        if_dump = self.vapi.sw_interface_slave_dump(bond0.sw_if_index)
-        self.assertFalse(self.pg0.is_interface_config_in_dump(if_dump))
-        self.assertFalse(self.pg1.is_interface_config_in_dump(if_dump))
-
-        # enslave pg0 and pg1 to BondEthernet0
-        self.logger.info("bond enslave interface pg0 to BondEthernet0")
-        bond0.enslave_vpp_bond_interface(sw_if_index=self.pg0.sw_if_index,
-                                         is_passive=0,
-                                         is_long_timeout=0)
-
-        self.logger.info("bond enslave interface pg1 to BondEthernet0")
-        bond0.enslave_vpp_bond_interface(sw_if_index=self.pg1.sw_if_index,
-                                         is_passive=0,
-                                         is_long_timeout=0)
-
-        # verify both slaves in BondEthernet0
-        if_dump = self.vapi.sw_interface_slave_dump(bond0.sw_if_index)
-        self.assertTrue(self.pg0.is_interface_config_in_dump(if_dump))
-        self.assertTrue(self.pg1.is_interface_config_in_dump(if_dump))
-
-        # detach interface pg0
-        self.logger.info("detach interface pg0")
-        bond0.detach_vpp_bond_interface(sw_if_index=self.pg0.sw_if_index)
-
-        # verify pg0 is not in BondEthernet0, but pg1 is
-        if_dump = self.vapi.sw_interface_slave_dump(bond0.sw_if_index)
-        self.assertFalse(self.pg0.is_interface_config_in_dump(if_dump))
-        self.assertTrue(self.pg1.is_interface_config_in_dump(if_dump))
-
-        # detach interface pg1
-        self.logger.info("detach interface pg1")
-        bond0.detach_vpp_bond_interface(sw_if_index=self.pg1.sw_if_index)
-
-        # verify pg0 and pg1 not in BondEthernet0
-        if_dump = self.vapi.sw_interface_slave_dump(bond0.sw_if_index)
-        self.assertFalse(self.pg0.is_interface_config_in_dump(if_dump))
-        self.assertFalse(self.pg1.is_interface_config_in_dump(if_dump))
+        # verify that interfaces can be enslaved and detached two times
+        for i in range(2):
+            # verify pg0 and pg1 not in BondEthernet0
+            if_dump = self.vapi.sw_interface_slave_dump(bond0.sw_if_index)
+            self.assertFalse(self.pg0.is_interface_config_in_dump(if_dump))
+            self.assertFalse(self.pg1.is_interface_config_in_dump(if_dump))
+
+            # enslave pg0 and pg1 to BondEthernet0
+            self.logger.info("bond enslave interface pg0 to BondEthernet0")
+            bond0.enslave_vpp_bond_interface(sw_if_index=self.pg0.sw_if_index,
+                                             is_passive=0,
+                                             is_long_timeout=0)
+
+            self.logger.info("bond enslave interface pg1 to BondEthernet0")
+            bond0.enslave_vpp_bond_interface(sw_if_index=self.pg1.sw_if_index,
+                                             is_passive=0,
+                                             is_long_timeout=0)
+            # verify both slaves in BondEthernet0
+            if_dump = self.vapi.sw_interface_slave_dump(bond0.sw_if_index)
+            self.assertTrue(self.pg0.is_interface_config_in_dump(if_dump))
+            self.assertTrue(self.pg1.is_interface_config_in_dump(if_dump))
+
+            # detach interface pg0
+            self.logger.info("detach interface pg0")
+            bond0.detach_vpp_bond_interface(sw_if_index=self.pg0.sw_if_index)
+
+            # verify pg0 is not in BondEthernet0, but pg1 is
+            if_dump = self.vapi.sw_interface_slave_dump(bond0.sw_if_index)
+            self.assertFalse(self.pg0.is_interface_config_in_dump(if_dump))
+            self.assertTrue(self.pg1.is_interface_config_in_dump(if_dump))
+
+            # detach interface pg1
+            self.logger.info("detach interface pg1")
+            bond0.detach_vpp_bond_interface(sw_if_index=self.pg1.sw_if_index)
+
+            # verify pg0 and pg1 not in BondEthernet0
+            if_dump = self.vapi.sw_interface_slave_dump(bond0.sw_if_index)
+            self.assertFalse(self.pg0.is_interface_config_in_dump(if_dump))
+            self.assertFalse(self.pg1.is_interface_config_in_dump(if_dump))
 
         bond0.remove_vpp_config()