BIER API and load-balancing fixes

Change-Id: Ibda19d786070c942c75016ab568c8361de2f24af
Signed-off-by: Neale Ranns <nranns@cisco.com>

4 files changed, 159 insertions, 21 deletions

diff --git a/test/test_bier.py b/test/test_bier.py
index 0276f95c4fc..9a1967cc459 100644
--- a/test/test_bier.py
+++ b/test/test_bier.py
@@ -202,6 +202,100 @@ class TestBier(VppTestCase):
         """BIER midpoint BSL:64"""
         self.bier_midpoint(BIERLength.BIER_LEN_64, 8, 64)
 
+    def test_bier_load_balance(self):
+        """BIER load-balance"""
+
+        #
+        # Add a BIER table for sub-domain 0, set 0, and BSL 256
+        #
+        bti = VppBierTableID(0, 0, BIERLength.BIER_LEN_64)
+        bt = VppBierTable(self, bti, 77)
+        bt.add_vpp_config()
+
+        #
+        # packets with varying entropy
+        #
+        pkts = []
+        for ii in range(257):
+            pkts.append((Ether(dst=self.pg0.local_mac,
+                               src=self.pg0.remote_mac) /
+                         MPLS(label=77, ttl=255) /
+                         BIER(length=BIERLength.BIER_LEN_64,
+                              entropy=ii,
+                              BitString=chr(255)*16) /
+                         IPv6(src=self.pg0.remote_ip6,
+                              dst=self.pg0.remote_ip6) /
+                         UDP(sport=1234, dport=1234) /
+                         Raw()))
+
+        #
+        # 4 next hops
+        #
+        nhs = [{'ip': "10.0.0.1", 'label': 201},
+               {'ip': "10.0.0.2", 'label': 202},
+               {'ip': "10.0.0.3", 'label': 203},
+               {'ip': "10.0.0.4", 'label': 204}]
+
+        for nh in nhs:
+            ipr = VppIpRoute(
+                self, nh['ip'], 32,
+                [VppRoutePath(self.pg1.remote_ip4,
+                              self.pg1.sw_if_index,
+                              labels=[VppMplsLabel(nh['label'])])])
+            ipr.add_vpp_config()
+
+        bier_route = VppBierRoute(
+            self, bti, 1,
+            [VppRoutePath(nhs[0]['ip'], 0xffffffff,
+                          labels=[VppMplsLabel(101)]),
+             VppRoutePath(nhs[1]['ip'], 0xffffffff,
+                          labels=[VppMplsLabel(101)])])
+        bier_route.add_vpp_config()
+
+        rx = self.send_and_expect(self.pg0, pkts, self.pg1)
+
+        #
+        # we should have recieved a packet from each neighbor
+        #
+        for nh in nhs[:2]:
+            self.assertTrue(sum(p[MPLS].label == nh['label'] for p in rx))
+
+        #
+        # add the other paths
+        #
+        bier_route.update_paths(
+            [VppRoutePath(nhs[0]['ip'], 0xffffffff,
+                          labels=[VppMplsLabel(101)]),
+             VppRoutePath(nhs[1]['ip'], 0xffffffff,
+                          labels=[VppMplsLabel(101)]),
+             VppRoutePath(nhs[2]['ip'], 0xffffffff,
+                          labels=[VppMplsLabel(101)]),
+             VppRoutePath(nhs[3]['ip'], 0xffffffff,
+                          labels=[VppMplsLabel(101)])])
+
+        rx = self.send_and_expect(self.pg0, pkts, self.pg1)
+        for nh in nhs:
+            self.assertTrue(sum(p[MPLS].label == nh['label'] for p in rx))
+
+        #
+        # remove first two paths
+        #
+        bier_route.remove_path(VppRoutePath(nhs[0]['ip'], 0xffffffff,
+                                            labels=[VppMplsLabel(101)]))
+        bier_route.remove_path(VppRoutePath(nhs[1]['ip'], 0xffffffff,
+                                            labels=[VppMplsLabel(101)]))
+
+        rx = self.send_and_expect(self.pg0, pkts, self.pg1)
+        for nh in nhs[2:]:
+            self.assertTrue(sum(p[MPLS].label == nh['label'] for p in rx))
+
+        #
+        # remove the last of the paths, deleteing the entry
+        #
+        bier_route.remove_all_paths()
+
+        self.send_and_assert_no_replies(self.pg0, pkts)
+
     def test_bier_head(self):
         """BIER head"""
 
diff --git a/test/vpp_bier.py b/test/vpp_bier.py
index 88dd79ce3b7..f389ca1b979 100644
--- a/test/vpp_bier.py
+++ b/test/vpp_bier.py
@@ -120,28 +120,31 @@ class VppBierRoute(VppObject):
         self.bp = bp
         self.paths = paths
 
+    def encode_path(self, p):
+        lstack = []
+        for l in p.nh_labels:
+            if type(l) == VppMplsLabel:
+                lstack.append(l.encode())
+            else:
+                lstack.append({'label': l, 'ttl': 255})
+        n_labels = len(lstack)
+        while (len(lstack) < 16):
+            lstack.append({})
+        return {'next_hop': p.nh_addr,
+                'weight': 1,
+                'afi': p.proto,
+                'sw_if_index': 0xffffffff,
+                'preference': 0,
+                'table_id': p.nh_table_id,
+                'next_hop_id': p.next_hop_id,
+                'is_udp_encap': p.is_udp_encap,
+                'n_labels': n_labels,
+                'label_stack': lstack}
+
     def encode_paths(self):
         br_paths = []
         for p in self.paths:
-            lstack = []
-            for l in p.nh_labels:
-                if type(l) == VppMplsLabel:
-                    lstack.append(l.encode())
-                else:
-                    lstack.append({'label': l, 'ttl': 255})
-            n_labels = len(lstack)
-            while (len(lstack) < 16):
-                lstack.append({})
-            br_paths.append({'next_hop': p.nh_addr,
-                             'weight': 1,
-                             'afi': p.proto,
-                             'sw_if_index': 0xffffffff,
-                             'preference': 0,
-                             'table_id': p.nh_table_id,
-                             'next_hop_id': p.next_hop_id,
-                             'is_udp_encap': p.is_udp_encap,
-                             'n_labels': n_labels,
-                             'label_stack': lstack})
+            br_paths.append(self.encode_path(p))
         return br_paths
 
     def add_vpp_config(self):
@@ -159,6 +162,42 @@ class VppBierRoute(VppObject):
             self.encode_paths(),
             is_add=0)
 
+    def update_paths(self, paths):
+        self.paths = paths
+        self._test.vapi.bier_route_add_del(
+            self.tbl_id,
+            self.bp,
+            self.encode_paths(),
+            is_replace=1)
+
+    def add_path(self, path):
+        self._test.vapi.bier_route_add_del(
+            self.tbl_id,
+            self.bp,
+            [self.encode_path(path)],
+            is_add=1,
+            is_replace=0)
+        self.paths.append(path)
+        self._test.registry.register(self, self._test.logger)
+
+    def remove_path(self, path):
+        self._test.vapi.bier_route_add_del(
+            self.tbl_id,
+            self.bp,
+            [self.encode_path(path)],
+            is_add=0,
+            is_replace=0)
+        self.paths.remove(path)
+
+    def remove_all_paths(self):
+        self._test.vapi.bier_route_add_del(
+            self.tbl_id,
+            self.bp,
+            [],
+            is_add=0,
+            is_replace=1)
+        self.paths = []
+
     def __str__(self):
         return self.object_id()
 
diff --git a/test/vpp_ip_route.py b/test/vpp_ip_route.py
index 9d6bfb77d93..18c27ffa942 100644
--- a/test/vpp_ip_route.py
+++ b/test/vpp_ip_route.py
@@ -192,6 +192,9 @@ class VppRoutePath(object):
                 'n_labels': len(self.nh_labels),
                 'label_stack': self.encode_labels()}
 
+    def __eq__(self, other):
+        return self.nh_addr == other.nh_addr
+
 
 class VppMRoutePath(VppRoutePath):
 
diff --git a/test/vpp_papi_provider.py b/test/vpp_papi_provider.py
index 61d80b21fb5..5ff7db990c0 100644
--- a/test/vpp_papi_provider.py
+++ b/test/vpp_papi_provider.py
@@ -3147,7 +3147,8 @@ class VppPapiProvider(object):
                            bti,
                            bp,
                            paths,
-                           is_add=1):
+                           is_add=1,
+                           is_replace=0):
         """ BIER Route add/del """
         return self.api(
             self.papi.bier_route_add_del,
@@ -3157,7 +3158,8 @@ class VppPapiProvider(object):
              'br_bp': bp,
              'br_n_paths': len(paths),
              'br_paths': paths,
-             'br_is_add': is_add})
+             'br_is_add': is_add,
+             'br_is_replace': is_replace})
 
     def bier_route_dump(self, bti):
         return self.api(