SR-MPLS: fixes and tests

- the FIB path takes a vector of type fib_mpls_label_t not u32 so the untype safe vec_add did not work
- write som eSR-MPLS tests
- allow an MPLS tunnel to resolve through a SR BSID

Change-Id: I2a18b9a9bf43584100ac269c4ebc286c9e3b3ea5
Signed-off-by: Neale Ranns <nranns@cisco.com>
(cherry picked from commit 7c922dc404c2c0a2d67d53ca05db1c1ae1598f44)

7 files changed, 316 insertions, 3 deletions

diff --git a/src/vnet/dpo/mpls_label_dpo.c b/src/vnet/dpo/mpls_label_dpo.c
index 0a7063cc99a..bee155b9035 100644
--- a/src/vnet/dpo/mpls_label_dpo.c
+++ b/src/vnet/dpo/mpls_label_dpo.c
@@ -205,7 +205,7 @@ format_mpls_label_dpo (u8 *s, va_list *args)
     }
 
     mld = mpls_label_dpo_get(index);
-    s = format(s, "mpls-label[%U%d]:",
+    s = format(s, "mpls-label[%U@%d]:",
                format_mpls_label_dpo_flags,
                (int) mld->mld_flags, index);
 
diff --git a/src/vnet/mpls/mpls.api b/src/vnet/mpls/mpls.api
index 6047d255aa7..7ab0f3750cc 100644
--- a/src/vnet/mpls/mpls.api
+++ b/src/vnet/mpls/mpls.api
@@ -54,6 +54,7 @@ define mpls_tunnel_add_del
   u8 mt_next_hop_preference;
   u8 mt_next_hop[16];
   u8 mt_next_hop_n_out_labels;
+  u32 mt_next_hop_via_label;
   u32 mt_next_hop_sw_if_index;
   u32 mt_next_hop_table_id;
   vl_api_fib_mpls_label_t mt_next_hop_out_label_stack[mt_next_hop_n_out_labels];
diff --git a/src/vnet/mpls/mpls_api.c b/src/vnet/mpls/mpls_api.c
index 9f5100a7f83..47a3408520e 100644
--- a/src/vnet/mpls/mpls_api.c
+++ b/src/vnet/mpls/mpls_api.c
@@ -306,6 +306,7 @@ vl_api_mpls_tunnel_add_del_t_handler (vl_api_mpls_tunnel_add_del_t * mp)
   u32 tunnel_sw_if_index;
   int ii;
   fib_route_path_t rpath, *rpaths = NULL;
+  u32 next_hop_via_label;
 
   memset (&rpath, 0, sizeof (rpath));
 
@@ -326,6 +327,14 @@ vl_api_mpls_tunnel_add_del_t_handler (vl_api_mpls_tunnel_add_del_t * mp)
   rpath.frp_sw_if_index = ntohl (mp->mt_next_hop_sw_if_index);
   rpath.frp_weight = 1;
 
+  next_hop_via_label = ntohl (mp->mt_next_hop_via_label);
+  if ((MPLS_LABEL_INVALID != next_hop_via_label) && (0 != next_hop_via_label))
+    {
+      rpath.frp_proto = DPO_PROTO_MPLS;
+      rpath.frp_local_label = next_hop_via_label;
+      rpath.frp_eos = MPLS_NON_EOS;
+    }
+
   if (mp->mt_is_add)
     {
       for (ii = 0; ii < mp->mt_next_hop_n_out_labels; ii++)
diff --git a/src/vnet/srmpls/sr_mpls_policy.c b/src/vnet/srmpls/sr_mpls_policy.c
index 5bb7fb2bff5..86cd169716a 100755
--- a/src/vnet/srmpls/sr_mpls_policy.c
+++ b/src/vnet/srmpls/sr_mpls_policy.c
@@ -61,6 +61,7 @@ create_sl (mpls_sr_policy_t * sr_policy, mpls_label_t * sl, u32 weight)
 {
   mpls_sr_main_t *sm = &sr_mpls_main;
   mpls_sr_sl_t *segment_list;
+  u32 ii;
 
   pool_get (sm->sid_lists, segment_list);
   memset (segment_list, 0, sizeof (*segment_list));
@@ -85,8 +86,24 @@ create_sl (mpls_sr_policy_t * sr_policy, mpls_label_t * sl, u32 weight)
       .frp_local_label = sl[0],
     };
 
-    if (vec_len (sl) - 1)
-      vec_add (path.frp_label_stack, sl + 1, vec_len (sl) - 1);
+    if (vec_len (sl) > 1)
+      {
+	vec_validate (path.frp_label_stack, vec_len (sl) - 2);
+	for (ii = 1; ii < vec_len (sl); ii++)
+	  {
+	    path.frp_label_stack[ii - 1].fml_value = sl[ii];
+	  }
+      }
+    else
+      {
+	/*
+	 * add an impliciet NULL label to allow non-eos recursion
+	 */
+	fib_mpls_label_t lbl = {
+	  .fml_value = MPLS_IETF_IMPLICIT_NULL_LABEL,
+	};
+	vec_add1 (path.frp_label_stack, lbl);
+      }
 
     fib_route_path_t *paths = NULL;
     vec_add1 (paths, path);
diff --git a/test/test_srmpls.py b/test/test_srmpls.py
new file mode 100644
index 00000000000..ded4a71fa40
--- /dev/null
+++ b/test/test_srmpls.py
@@ -0,0 +1,271 @@
+#!/usr/bin/env python
+
+import unittest
+import socket
+
+from framework import VppTestCase, VppTestRunner
+from vpp_ip_route import VppIpRoute, VppRoutePath, VppMplsRoute, \
+    VppMplsIpBind, VppIpMRoute, VppMRoutePath, \
+    MRouteItfFlags, MRouteEntryFlags, DpoProto, VppIpTable, VppMplsTable, \
+    VppMplsLabel, MplsLspMode
+from vpp_mpls_tunnel_interface import VppMPLSTunnelInterface
+
+from scapy.packet import Raw
+from scapy.layers.l2 import Ether
+from scapy.layers.inet import IP, UDP, ICMP
+from scapy.layers.inet6 import IPv6, ICMPv6TimeExceeded
+from scapy.contrib.mpls import MPLS
+
+
+def verify_filter(capture, sent):
+    if not len(capture) == len(sent):
+        # filter out any IPv6 RAs from the capture
+        for p in capture:
+            if p.haslayer(IPv6):
+                capture.remove(p)
+    return capture
+
+
+def verify_mpls_stack(tst, rx, mpls_labels):
+    # the rx'd packet has the MPLS label popped
+    eth = rx[Ether]
+    tst.assertEqual(eth.type, 0x8847)
+
+    rx_mpls = rx[MPLS]
+
+    for ii in range(len(mpls_labels)):
+        tst.assertEqual(rx_mpls.label, mpls_labels[ii].value)
+        tst.assertEqual(rx_mpls.cos, mpls_labels[ii].exp)
+        tst.assertEqual(rx_mpls.ttl, mpls_labels[ii].ttl)
+
+        if ii == len(mpls_labels) - 1:
+            tst.assertEqual(rx_mpls.s, 1)
+        else:
+            # not end of stack
+            tst.assertEqual(rx_mpls.s, 0)
+            # pop the label to expose the next
+            rx_mpls = rx_mpls[MPLS].payload
+
+
+class TestSRMPLS(VppTestCase):
+    """ SR-MPLS Test Case """
+
+    def setUp(self):
+        super(TestSRMPLS, self).setUp()
+
+        # create 2 pg interfaces
+        self.create_pg_interfaces(range(4))
+
+        # setup both interfaces
+        # assign them different tables.
+        table_id = 0
+        self.tables = []
+
+        tbl = VppMplsTable(self, 0)
+        tbl.add_vpp_config()
+        self.tables.append(tbl)
+
+        for i in self.pg_interfaces:
+            i.admin_up()
+            i.config_ip4()
+            i.resolve_arp()
+            i.config_ip6()
+            i.resolve_ndp()
+            i.enable_mpls()
+
+    def tearDown(self):
+        for i in self.pg_interfaces:
+            i.unconfig_ip4()
+            i.unconfig_ip6()
+            i.ip6_disable()
+            i.disable_mpls()
+            i.admin_down()
+        super(TestSRMPLS, self).tearDown()
+
+    def create_stream_ip4(self, src_if, dst_ip, ip_ttl=64, ip_dscp=0):
+        self.reset_packet_infos()
+        pkts = []
+        for i in range(0, 257):
+            info = self.create_packet_info(src_if, src_if)
+            payload = self.info_to_payload(info)
+            p = (Ether(dst=src_if.local_mac, src=src_if.remote_mac) /
+                 IP(src=src_if.remote_ip4, dst=dst_ip,
+                    ttl=ip_ttl, tos=ip_dscp) /
+                 UDP(sport=1234, dport=1234) /
+                 Raw(payload))
+            info.data = p.copy()
+            pkts.append(p)
+        return pkts
+
+    def verify_capture_labelled_ip4(self, src_if, capture, sent,
+                                    mpls_labels, ip_ttl=None):
+        try:
+            capture = verify_filter(capture, sent)
+
+            self.assertEqual(len(capture), len(sent))
+
+            for i in range(len(capture)):
+                tx = sent[i]
+                rx = capture[i]
+                tx_ip = tx[IP]
+                rx_ip = rx[IP]
+
+                verify_mpls_stack(self, rx, mpls_labels)
+
+                self.assertEqual(rx_ip.src, tx_ip.src)
+                self.assertEqual(rx_ip.dst, tx_ip.dst)
+                if not ip_ttl:
+                    # IP processing post pop has decremented the TTL
+                    self.assertEqual(rx_ip.ttl + 1, tx_ip.ttl)
+                else:
+                    self.assertEqual(rx_ip.ttl, ip_ttl)
+
+        except:
+            raise
+
+    def verify_capture_tunneled_ip4(self, src_if, capture, sent, mpls_labels):
+        try:
+            capture = verify_filter(capture, sent)
+
+            self.assertEqual(len(capture), len(sent))
+
+            for i in range(len(capture)):
+                tx = sent[i]
+                rx = capture[i]
+                tx_ip = tx[IP]
+                rx_ip = rx[IP]
+
+                verify_mpls_stack(self, rx, mpls_labels)
+
+                self.assertEqual(rx_ip.src, tx_ip.src)
+                self.assertEqual(rx_ip.dst, tx_ip.dst)
+                # IP processing post pop has decremented the TTL
+                self.assertEqual(rx_ip.ttl + 1, tx_ip.ttl)
+
+        except:
+            raise
+
+    def test_sr_mpls(self):
+        """ SR MPLS """
+
+        #
+        # A simple MPLS xconnect - neos label in label out
+        #
+        route_32_eos = VppMplsRoute(self, 32, 0,
+                                    [VppRoutePath(self.pg0.remote_ip4,
+                                                  self.pg0.sw_if_index,
+                                                  labels=[VppMplsLabel(32)])])
+        route_32_eos.add_vpp_config()
+
+        #
+        # A binding SID with only one label
+        #
+        self.vapi.sr_mpls_policy_add(999, 1, 0, [32])
+
+        #
+        # A labeled IP route that resolves thru the binding SID
+        #
+        ip_10_0_0_1 = VppIpRoute(self, "10.0.0.1", 32,
+                                 [VppRoutePath("0.0.0.0",
+                                               0xffffffff,
+                                               nh_via_label=999,
+                                               labels=[VppMplsLabel(55)])])
+        ip_10_0_0_1.add_vpp_config()
+
+        tx = self.create_stream_ip4(self.pg1, "10.0.0.1")
+        rx = self.send_and_expect(self.pg1, tx, self.pg0)
+        self.verify_capture_labelled_ip4(self.pg0, rx, tx,
+                                         [VppMplsLabel(32),
+                                          VppMplsLabel(55)])
+
+        #
+        # An unlabeled IP route that resolves thru the binding SID
+        #
+        ip_10_0_0_1 = VppIpRoute(self, "10.0.0.2", 32,
+                                 [VppRoutePath("0.0.0.0",
+                                               0xffffffff,
+                                               nh_via_label=999)])
+        ip_10_0_0_1.add_vpp_config()
+
+        tx = self.create_stream_ip4(self.pg1, "10.0.0.2")
+        rx = self.send_and_expect(self.pg1, tx, self.pg0)
+        self.verify_capture_labelled_ip4(self.pg0, rx, tx,
+                                         [VppMplsLabel(32)])
+
+        self.vapi.sr_mpls_policy_del(999)
+
+        #
+        # this time the SID has many labels pushed
+        #
+        self.vapi.sr_mpls_policy_add(999, 1, 0, [32, 33, 34])
+
+        tx = self.create_stream_ip4(self.pg1, "10.0.0.1")
+        rx = self.send_and_expect(self.pg1, tx, self.pg0)
+        self.verify_capture_labelled_ip4(self.pg0, rx, tx,
+                                         [VppMplsLabel(32),
+                                          VppMplsLabel(33),
+                                          VppMplsLabel(34),
+                                          VppMplsLabel(55)])
+        tx = self.create_stream_ip4(self.pg1, "10.0.0.2")
+        rx = self.send_and_expect(self.pg1, tx, self.pg0)
+        self.verify_capture_labelled_ip4(self.pg0, rx, tx,
+                                         [VppMplsLabel(32),
+                                          VppMplsLabel(33),
+                                          VppMplsLabel(34)])
+
+        #
+        # Resolve an MPLS tunnel via the SID
+        #
+        mpls_tun = VppMPLSTunnelInterface(
+            self,
+            [VppRoutePath("0.0.0.0",
+                          0xffffffff,
+                          nh_via_label=999,
+                          labels=[VppMplsLabel(44),
+                                  VppMplsLabel(46)])])
+        mpls_tun.add_vpp_config()
+        mpls_tun.admin_up()
+
+        #
+        # add an unlabelled route through the new tunnel
+        #
+        route_10_0_0_3 = VppIpRoute(self, "10.0.0.3", 32,
+                                    [VppRoutePath("0.0.0.0",
+                                                  mpls_tun._sw_if_index)])
+        route_10_0_0_3.add_vpp_config()
+        self.logger.info(self.vapi.cli("sh mpls tun 0"))
+        self.logger.info(self.vapi.cli("sh adj 21"))
+
+        tx = self.create_stream_ip4(self.pg1, "10.0.0.3")
+        rx = self.send_and_expect(self.pg1, tx, self.pg0)
+        self.verify_capture_tunneled_ip4(self.pg0, rx, tx,
+                                         [VppMplsLabel(32),
+                                          VppMplsLabel(33),
+                                          VppMplsLabel(34),
+                                          VppMplsLabel(44),
+                                          VppMplsLabel(46)])
+
+        #
+        # add a labelled route through the new tunnel
+        #
+        route_10_0_0_3 = VppIpRoute(self, "10.0.0.4", 32,
+                                    [VppRoutePath("0.0.0.0",
+                                                  mpls_tun._sw_if_index,
+                                                  labels=[VppMplsLabel(55)])])
+        route_10_0_0_3.add_vpp_config()
+
+        tx = self.create_stream_ip4(self.pg1, "10.0.0.4")
+        rx = self.send_and_expect(self.pg1, tx, self.pg0)
+        self.verify_capture_tunneled_ip4(self.pg0, rx, tx,
+                                         [VppMplsLabel(32),
+                                          VppMplsLabel(33),
+                                          VppMplsLabel(34),
+                                          VppMplsLabel(44),
+                                          VppMplsLabel(46),
+                                          VppMplsLabel(55)])
+
+        self.vapi.sr_mpls_policy_del(999)
+
+
+if __name__ == '__main__':
+    unittest.main(testRunner=VppTestRunner)
diff --git a/test/vpp_mpls_tunnel_interface.py b/test/vpp_mpls_tunnel_interface.py
index 995ffb7dd54..b125f3c7277 100644
--- a/test/vpp_mpls_tunnel_interface.py
+++ b/test/vpp_mpls_tunnel_interface.py
@@ -26,6 +26,7 @@ class VppMPLSTunnelInterface(VppInterface):
                 path.nh_itf,
                 path.nh_table_id,
                 path.weight,
+                next_hop_via_label=path.nh_via_label,
                 next_hop_out_label_stack=lstack,
                 next_hop_n_out_labels=len(lstack),
                 is_multicast=self.is_multicast,
@@ -42,6 +43,7 @@ class VppMPLSTunnelInterface(VppInterface):
                 path.nh_itf,
                 path.nh_table_id,
                 path.weight,
+                next_hop_via_label=path.nh_via_label,
                 next_hop_out_label_stack=path.nh_labels,
                 next_hop_n_out_labels=len(path.nh_labels),
                 is_add=0)
diff --git a/test/vpp_papi_provider.py b/test/vpp_papi_provider.py
index 8bfc18e5a5c..30777d3d495 100644
--- a/test/vpp_papi_provider.py
+++ b/test/vpp_papi_provider.py
@@ -1329,6 +1329,7 @@ class VppPapiProvider(object):
              'mt_next_hop_n_out_labels': next_hop_n_out_labels,
              'mt_next_hop_sw_if_index': next_hop_sw_if_index,
              'mt_next_hop_table_id': next_hop_table_id,
+             'mt_next_hop_via_label': next_hop_via_label,
              'mt_next_hop_out_label_stack': next_hop_out_label_stack})
 
     def nat44_interface_add_del_feature(
@@ -2695,6 +2696,18 @@ class VppPapiProvider(object):
                          'decap_vrf_id': decap_vrf_id,
                          'client_mac': client_mac})
 
+    def sr_mpls_policy_add(self, bsid, weight, type, segments):
+        return self.api(self.papi.sr_mpls_policy_add,
+                        {'bsid': bsid,
+                         'weight': weight,
+                         'type': type,
+                         'n_segments': len(segments),
+                         'segments': segments})
+
+    def sr_mpls_policy_del(self, bsid):
+        return self.api(self.papi.sr_mpls_policy_del,
+                        {'bsid': bsid})
+
     def sr_localsid_add_del(self,
                             localsid,
                             behavior,