Pmsi tunnel v6 length

bgpd/bgp_attr.c

@@ -3773,7 +3773,8 @@ bgp_attr_pmsi_tunnel(struct bgp_attr_parser_args *args)
 					  args->total);
 	}
 	if (tnl_type == PMSI_TNLTYPE_INGR_REPL) {
-		if (length != 9) {
+		if (length != BGP_ATTR_PMSI_TUNNEL_V4_LENGTH &&
+		    length != BGP_ATTR_PMSI_TUNNEL_V6_LENGTH) {
 			flog_err(EC_BGP_ATTR_PMSI_LEN,
 				 "Bad PMSI tunnel attribute length %d for IR",
 				 length);
@@ -5654,13 +5655,22 @@ bgp_size_t bgp_packet_attribute(struct bgp *bgp, struct peer *peer, struct strea
 	if (bgp_attr_exists(attr, BGP_ATTR_PMSI_TUNNEL)) {
 		stream_putc(s, BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS);
 		stream_putc(s, BGP_ATTR_PMSI_TUNNEL);
-		stream_putc(s, 9); // Length
-		stream_putc(s, 0); // Flags
-		stream_putc(s, bgp_attr_get_pmsi_tnl_type(attr));
-		stream_put(s, &(attr->label),
-			   BGP_LABEL_BYTES); // MPLS Label / VXLAN VNI
-		stream_put_ipv4(s, attr->nexthop.s_addr);
-		// Unicast tunnel endpoint IP address
+		if (attr->nexthop.s_addr == INADDR_ANY &&
+		    (attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV6_GLOBAL ||
+		     attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL)) {
+			stream_putc(s, BGP_ATTR_PMSI_TUNNEL_V6_LENGTH);
+			stream_putc(s, 0);
+			stream_putc(s, bgp_attr_get_pmsi_tnl_type(attr));
+			stream_put(s, &attr->label, BGP_LABEL_BYTES);
+			stream_put(s, &attr->mp_nexthop_global, 16);
+		} else {
+			stream_putc(s, BGP_ATTR_PMSI_TUNNEL_V4_LENGTH); // Length
+			stream_putc(s, 0);				// Flags
+			stream_putc(s, bgp_attr_get_pmsi_tnl_type(attr));
+			stream_put(s, &(attr->label),
+				   BGP_LABEL_BYTES); // MPLS Label / VXLAN VNI
+			stream_put_ipv4(s, attr->nexthop.s_addr);
+		}
 	}
 
 	/* OTC */

bgpd/bgp_attr.h

@@ -108,6 +108,9 @@ enum pta_type {
 	PMSI_TNLTYPE_MAX = PMSI_TNLTYPE_MLDP_MP2MP
 };
 
+#define BGP_ATTR_PMSI_TUNNEL_V4_LENGTH 9
+#define BGP_ATTR_PMSI_TUNNEL_V6_LENGTH 21
+
 /*
  * Prefix-SID type-4
  * SRv6-VPN-SID-TLV

tests/topotests/bgp_evpn_v6_pmsi_tunnel/r1/evpn_type3.json

@@ -0,0 +1,9 @@
+{
+    "101": {
+        "type": "L2",
+        "numRemoteVteps": 1,
+        "remoteVteps": [
+            "fd00:100::2"
+        ]
+    }
+}

tests/topotests/bgp_evpn_v6_pmsi_tunnel/r1/frr.conf

@@ -0,0 +1,15 @@
+interface r1-eth0
+ ipv6 address fd00:100::1/64
+!
+router bgp 65000
+ bgp router-id 10.10.10.1
+ bgp log-neighbor-changes
+ no bgp default ipv4-unicast
+ neighbor fd00:100::2 remote-as 65000
+ neighbor fd00:100::2 capability extended-nexthop
+ !
+ address-family l2vpn evpn
+  neighbor fd00:100::2 activate
+  advertise-all-vni
+ exit-address-family
+!

tests/topotests/bgp_evpn_v6_pmsi_tunnel/r2/evpn_type3.json

@@ -0,0 +1,9 @@
+{
+    "101": {
+        "type": "L2",
+        "numRemoteVteps": 1,
+        "remoteVteps": [
+            "fd00:100::1"
+        ]
+    }
+}

tests/topotests/bgp_evpn_v6_pmsi_tunnel/r2/frr.conf

@@ -0,0 +1,15 @@
+interface r2-eth0
+ ipv6 address fd00:100::2/64
+!
+router bgp 65000
+ bgp router-id 10.10.10.2
+ bgp log-neighbor-changes
+ no bgp default ipv4-unicast
+ neighbor fd00:100::1 remote-as 65000
+ neighbor fd00:100::1 capability extended-nexthop
+ !
+ address-family l2vpn evpn
+  neighbor fd00:100::1 activate
+  advertise-all-vni
+ exit-address-family
+!

tests/topotests/bgp_evpn_v6_pmsi_tunnel/test_bgp_evpn_v6_pmsi_tunnel.py

@@ -0,0 +1,147 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: ISC
+
+#
+# test_bgp_evpn_v6_pmsi_tunnel.py
+#
+# Copyright (c) 2025 Nvidia Inc.
+#                    Donald Sharp
+
+"""
+Test that EVPN with an IPv6-only underlay correctly encodes and parses
+the PMSI Tunnel attribute with an IPv6 tunnel identifier (length 21).
+
+Type-3 IMET routes carry the PMSI Tunnel attribute, so this test verifies
+that two FRR routers with IPv6-only EVPN peering and IPv6 VTEPs can
+exchange type-3 routes and install remote VTEPs.
+"""
+
+import json
+from functools import partial
+import os
+import sys
+import pytest
+import platform
+
+CWD = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(CWD, "../"))
+
+from lib import topotest
+from lib.topogen import Topogen, get_topogen
+from lib.topolog import logger
+
+pytestmark = [pytest.mark.bgpd]
+
+
+def build_topo(tgen):
+    tgen.add_router("r1")
+    tgen.add_router("r2")
+
+    switch = tgen.add_switch("s1")
+    switch.add_link(tgen.gears["r1"])
+    switch.add_link(tgen.gears["r2"])
+
+
+def setup_module(mod):
+    tgen = Topogen(build_topo, mod.__name__)
+    tgen.start_topology()
+
+    krel = platform.release()
+    if topotest.version_cmp(krel, "4.18") < 0:
+        logger.info(
+            'BGP EVPN v6 PMSI tests require kernel >= 4.18 (have "{}")'.format(krel)
+        )
+        return pytest.skip("Kernel too old for EVPN NETNS test")
+
+    cmds_vxlan = [
+        "ip link add name bridge-101 up type bridge stp_state 0",
+        "ip link set dev bridge-101 up",
+        "ip link add name vxlan-101 type vxlan id 101 dstport 4789 dev {0}-eth0 local {1}",
+        "ip link set dev vxlan-101 master bridge-101",
+        "ip link set vxlan-101 up type bridge_slave learning off flood off mcast_flood off",
+    ]
+
+    for rname, vtep_ip in [("r1", "fd00:100::1"), ("r2", "fd00:100::2")]:
+        router = tgen.gears[rname]
+        for cmd in cmds_vxlan:
+            formatted = cmd.format(rname, vtep_ip)
+            logger.info("cmd to {}: {}".format(rname, formatted))
+            output = router.cmd_raises(formatted)
+            logger.info("result: " + output)
+
+    for rname, router in tgen.routers().items():
+        logger.info("Loading router %s" % rname)
+        router.load_frr_config(os.path.join(CWD, "{}/frr.conf".format(rname)))
+
+    tgen.start_router()
+
+
+def teardown_module(_mod):
+    tgen = get_topogen()
+    tgen.stop_topology()
+
+
+def test_bgp_convergence():
+    """
+    Assert that BGP EVPN sessions come up between r1 and r2 over IPv6.
+    """
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    for rname in ("r1", "r2"):
+        router = tgen.gears[rname]
+
+        expected = {"peers": {}}
+        if rname == "r1":
+            expected["peers"]["fd00:100::2"] = {"state": "Established"}
+        else:
+            expected["peers"]["fd00:100::1"] = {"state": "Established"}
+
+        test_func = partial(
+            topotest.router_json_cmp,
+            router,
+            "show bgp l2vpn evpn summary json",
+            expected,
+        )
+        _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+        assert result is None, '"{}" BGP session did not establish'.format(rname)
+
+
+def test_evpn_type3_routes():
+    """
+    Verify EVPN type-3 IMET routes are received. These carry the PMSI Tunnel
+    attribute. With IPv6-only peering, the PMSI tunnel identifier must be
+    encoded as 21 bytes (IPv6). Without the fix, these routes would be
+    rejected as malformed.
+    """
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    for rname in ("r1", "r2"):
+        router = tgen.gears[rname]
+        json_file = "{}/{}/evpn_type3.json".format(CWD, rname)
+        expected = json.loads(open(json_file).read())
+
+        test_func = partial(
+            topotest.router_json_cmp,
+            router,
+            "show evpn vni json",
+            expected,
+        )
+        _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+        assert result is None, '"{}" EVPN type-3 route check failed'.format(rname)
+
+
+def test_memory_leak():
+    tgen = get_topogen()
+    if not tgen.is_memleak_enabled():
+        pytest.skip("Memory leak test/report is disabled")
+
+    tgen.report_memory_leaks()
+
+
+if __name__ == "__main__":
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))