Merge pull request #12322 from fdumontet6WIND/confed_num

bgp:  fix case where confederation id same as member-as

bgpd/bgp_aspath.c

@@ -1187,6 +1187,33 @@ int aspath_loop_check(struct aspath *aspath, as_t asno)
 	return count;
 }
 
+/* AS path loop check.  If aspath contains asno
+ * that is a confed id then return >= 1.
+ */
+int aspath_loop_check_confed(struct aspath *aspath, as_t asno)
+{
+	struct assegment *seg;
+	int count = 0;
+
+	if (aspath == NULL || aspath->segments == NULL)
+		return 0;
+
+	seg = aspath->segments;
+
+	while (seg) {
+		unsigned int i;
+
+		for (i = 0; i < seg->length; i++)
+			if (seg->type != AS_CONFED_SEQUENCE &&
+			    seg->type != AS_CONFED_SET && seg->as[i] == asno)
+				count++;
+
+		seg = seg->next;
+	}
+	return count;
+}
+
+
 /* When all of AS path is private AS return 1.  */
 bool aspath_private_as_check(struct aspath *aspath)
 {

bgpd/bgp_aspath.h

@@ -111,6 +111,7 @@ extern unsigned int aspath_key_make(const void *p);
 extern unsigned int aspath_get_first_as(struct aspath *aspath);
 extern unsigned int aspath_get_last_as(struct aspath *aspath);
 extern int aspath_loop_check(struct aspath *aspath, as_t asno);
+extern int aspath_loop_check_confed(struct aspath *aspath, as_t asno);
 extern bool aspath_private_as_check(struct aspath *aspath);
 extern struct aspath *aspath_replace_specific_asn(struct aspath *aspath,
 						  as_t target_asn,

bgpd/bgp_route.c

@@ -2197,7 +2197,7 @@ bool subgroup_announce_check(struct bgp_dest *dest, struct bgp_path_info *pi,
 
 	/* If we're a CONFED we need to loop check the CONFED ID too */
 	if (CHECK_FLAG(bgp->config, BGP_CONFIG_CONFEDERATION)) {
-		if (aspath_loop_check(piattr->aspath, bgp->confed_id)) {
+		if (aspath_loop_check_confed(piattr->aspath, bgp->confed_id)) {
 			if (bgp_debug_update(NULL, p, subgrp->update_group, 0))
 				zlog_debug(
 					"%pBP [Update:SEND] suppress announcement to peer AS %u is AS path.",
@@ -4114,16 +4114,23 @@ int bgp_update(struct peer *peer, const struct prefix *p, uint32_t addpath_id,
 
 	/* AS path loop check. */
 	if (do_loop_check) {
-		if (aspath_loop_check(attr->aspath, bgp->as) > allowas_in ||
+		if (aspath_loop_check(attr->aspath, bgp->as) >
-		    (CHECK_FLAG(bgp->config, BGP_CONFIG_CONFEDERATION) &&
+		    peer->allowas_in[afi][safi]) {
-		     (aspath_loop_check(attr->aspath, bgp->confed_id) >
-		      allowas_in))) {
 			peer->stat_pfx_aspath_loop++;
 			reason = "as-path contains our own AS;";
 			goto filtered;
 		}
 	}
 
+	/* If we're a CONFED we need to loop check the CONFED ID too */
+	if (CHECK_FLAG(bgp->config, BGP_CONFIG_CONFEDERATION) && do_loop_check)
+		if (aspath_loop_check_confed(attr->aspath, bgp->confed_id) >
+		    peer->allowas_in[afi][safi]) {
+			peer->stat_pfx_aspath_loop++;
+			reason = "as-path contains our own confed AS;";
+			goto filtered;
+		}
+
 	/* Route reflector originator ID check. If ACCEPT_OWN mechanism is
 	 * enabled, then take care of that too.
 	 */

bgpd/bgp_vty.c

@@ -1960,13 +1960,6 @@ DEFUN (bgp_confederation_peers,
 
 	for (i = idx_asn; i < argc; i++) {
 		as = strtoul(argv[i]->arg, NULL, 10);
-
-		if (bgp->as == as) {
-			vty_out(vty,
-				"%% Local member-AS not allowed in confed peer list\n");
-			continue;
-		}
-
 		bgp_confederation_peers_add(bgp, as);
 	}
 	return CMD_SUCCESS;

bgpd/bgpd.c

@@ -671,7 +671,7 @@ void bgp_confederation_peers_add(struct bgp *bgp, as_t as)
 	struct peer *peer;
 	struct listnode *node, *nnode;
 
-	if (bgp->as == as)
+	if (!bgp)
 		return;
 
 	if (bgp_confederation_peers_check(bgp, as))
@@ -687,8 +687,8 @@ void bgp_confederation_peers_add(struct bgp *bgp, as_t as)
 	if (bgp_config_check(bgp, BGP_CONFIG_CONFEDERATION)) {
 		for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
 			if (peer->as == as) {
-				(void)peer_sort(peer);
 				peer->local_as = bgp->as;
+				(void)peer_sort(peer);
 				if (BGP_IS_VALID_STATE_FOR_NOTIF(
 					    peer->status)) {
 					peer->last_reset =
@@ -738,8 +738,8 @@ void bgp_confederation_peers_remove(struct bgp *bgp, as_t as)
 	if (bgp_config_check(bgp, BGP_CONFIG_CONFEDERATION)) {
 		for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
 			if (peer->as == as) {
-				(void)peer_sort(peer);
 				peer->local_as = bgp->confed_id;
+				(void)peer_sort(peer);
 				if (BGP_IS_VALID_STATE_FOR_NOTIF(
 					    peer->status)) {
 					peer->last_reset =

tests/topotests/bgp_confed1/r1/bgp_ipv4_unicast.json

@@ -0,0 +1,63 @@
+{
+ "vrfId":0,
+ "vrfName":"default",
+ "routerId":"203.0.113.1",
+ "defaultLocPrf":100,
+ "localAS":100,
+ "routes":{"203.0.113.0/28":[
+  {
+    "network":"203.0.113.0\/28",
+    "peerId":"(unspec)",
+    "path":"",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"0.0.0.0",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+],"203.0.113.16/28":[
+  {
+    "network":"203.0.113.16\/28",
+    "peerId":"192.0.2.2",
+    "path":"300",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"192.0.2.2",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+],"203.0.113.32/28":[
+  {
+    "network":"203.0.113.32\/28",
+    "peerId":"192.0.2.2",
+    "path":"300",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"192.0.2.2",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+],"203.0.113.48/28":[
+  {
+    "network":"203.0.113.48\/28",
+    "peerId":"192.0.2.2",
+    "path":"300 400",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"192.0.2.2",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+] }  }

tests/topotests/bgp_confed1/r1/bgp_summary.json

@@ -0,0 +1,13 @@
+{
+    "ipv4Unicast":{
+      "routerId":"203.0.113.1",
+      "as":100,
+      "peers":{
+        "192.0.2.2":{
+          "remoteAs": 300,
+          "state": "Established",
+          "peerState":"OK"  
+      }
+    }
+  }
+}

tests/topotests/bgp_confed1/r1/bgpd.conf

@@ -0,0 +1,13 @@
+debug bgp neighbor-events
+debug bgp nht
+debug bgp updates in
+debug bgp updates out
+!
+router bgp 100
+ no bgp ebgp-requires-policy
+!
+ neighbor 192.0.2.2 remote-as 300
+ address-family ipv4 unicast
+  network 203.0.113.0/28
+ exit-address-family
+!

tests/topotests/bgp_confed1/r1/zebra.conf

@@ -0,0 +1,6 @@
+interface r1-eth0
+ ip address 192.0.2.1/28
+!
+interface lo
+ ip address 203.0.113.1/28
+!

tests/topotests/bgp_confed1/r2/bgp_ipv4_unicast.json

@@ -0,0 +1,63 @@
+{
+ "vrfId":0,
+ "vrfName":"default",
+ "routerId":"203.0.113.17",
+ "defaultLocPrf":100,
+ "localAS":200,
+ "routes":{"203.0.113.0/28": [
+  {
+    "network":"203.0.113.0\/28",
+    "peerId":"192.0.2.1",
+    "path":"100",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"192.0.2.1",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+],"203.0.113.16/28":[
+  {
+    "network":"203.0.113.16\/28",
+    "peerId":"(unspec)",
+    "path":"",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"0.0.0.0",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+],"203.0.113.32/28":[
+  {
+    "network":"203.0.113.32\/28",
+    "peerId":"192.0.2.18",
+    "path":"(300)",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"192.0.2.18",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+],"203.0.113.48/28":[
+  {
+    "network":"203.0.113.48\/28",
+    "peerId":"192.0.2.18",
+    "path":"(300) 400",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"192.0.2.50",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+] } }

tests/topotests/bgp_confed1/r2/bgp_summary.json

@@ -0,0 +1,18 @@
+{
+    "ipv4Unicast":{
+    "routerId":"203.0.113.17",
+    "as":200,
+    "peers":{
+      "192.0.2.1":{
+        "remoteAs":100,
+         "state":"Established",
+         "peerState":"OK"
+      },
+      "192.0.2.18":{
+        "remoteAs":300,
+         "state":"Established",
+         "peerState":"OK"
+      }
+    }
+  }
+}

tests/topotests/bgp_confed1/r2/bgpd.conf

@@ -0,0 +1,18 @@
+debug bgp neighbor-events
+debug bgp nht
+debug bgp updates in
+debug bgp updates out
+!
+router bgp 200
+ no bgp ebgp-requires-policy
+ bgp confederation identifier 300
+ bgp confederation peers 300
+ neighbor 192.0.2.1 remote-as 100
+ neighbor 192.0.2.18 remote-as 300
+ !
+ address-family ipv4 unicast
+  network 203.0.113.16/28
+  neighbor 192.0.2.18 default-originate
+ exit-address-family
+!
+

tests/topotests/bgp_confed1/r2/isisd.conf

@@ -0,0 +1,8 @@
+interface r2-eth1
+ ip router isis 1
+ isis circuit-type level-2-only
+
+router isis 1
+ is-type level-2-only
+ net 49.0001.0002.0002.0002.00
+ redistribute ipv4 connected level-2

tests/topotests/bgp_confed1/r2/zebra.conf

@@ -0,0 +1,9 @@
+interface r2-eth0
+ ip address 192.0.2.2/28
+!
+interface r2-eth1
+ ip address 192.0.2.17/28
+!
+interface lo
+ ip address 203.0.113.17/28
+!

tests/topotests/bgp_confed1/r3/bgp_ipv4_unicast.json

@@ -0,0 +1,77 @@
+{
+ "vrfId":0,
+ "vrfName":"default",
+ "routerId":"203.0.113.33",
+ "defaultLocPrf":100,
+ "localAS":300,
+ "routes":{"0.0.0.0/0":[
+  {
+    "network":"0.0.0.0\/0",
+    "peerId":"192.0.2.17",
+    "path":"(200)",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"192.0.2.17",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+],"203.0.113.0/28":[
+  {
+    "network":"203.0.113.0\/28",
+    "peerId":"192.0.2.17",
+    "path":"(200) 100",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"192.0.2.1",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+],"203.0.113.16/28":[
+  {
+    "network":"203.0.113.16\/28",
+    "peerId":"192.0.2.17",
+    "path":"(200)",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"192.0.2.17",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+],"203.0.113.32/28":[
+  {
+    "network":"203.0.113.32\/28",
+    "peerId":"(unspec)",
+    "path":"",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"0.0.0.0",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+],"203.0.113.48/28":[
+  {
+    "network":"203.0.113.48\/28",
+    "peerId":"192.0.2.50",
+    "path":"400",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"192.0.2.50",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+] } }

tests/topotests/bgp_confed1/r3/bgp_summary.json

@@ -0,0 +1,18 @@
+{
+    "ipv4Unicast":{
+    "routerId":"203.0.113.33",
+    "as":300,
+    "peers":{
+      "192.0.2.17":{
+        "remoteAs":200,
+         "state":"Established",
+         "peerState":"OK"
+      },
+      "192.0.2.50":{
+        "remoteAs":400,
+         "state":"Established",
+         "peerState":"OK"
+      }
+    }
+  }
+}

tests/topotests/bgp_confed1/r3/bgpd.conf

@@ -0,0 +1,17 @@
+debug bgp neighbor-events
+debug bgp nht
+debug bgp updates in
+debug bgp updates out
+!
+router bgp 300
+ no bgp ebgp-requires-policy
+ bgp confederation identifier 300
+ bgp confederation peers 200
+ neighbor 192.0.2.17 remote-as 200
+ neighbor 192.0.2.50 remote-as 400
+!
+ address-family ipv4 unicast
+  network 203.0.113.32/28
+ exit-address-family
+!
+

tests/topotests/bgp_confed1/r3/isisd.conf

@@ -0,0 +1,8 @@
+interface r3-eth1
+ ip router isis 1
+ isis circuit-type level-2-only
+
+router isis 1
+ is-type level-2-only
+ net 49.0001.0003.0003.0003.00
+ redistribute ipv4 connected level-2

tests/topotests/bgp_confed1/r3/zebra.conf

@@ -0,0 +1,10 @@
+!
+interface r3-eth0
+ ip address 192.0.2.49/28
+!
+interface r3-eth1
+ ip address 192.0.2.18/28
+!
+interface lo
+ ip address 203.0.113.33/28
+!

tests/topotests/bgp_confed1/r4/bgp_ipv4_unicast.json

@@ -0,0 +1,77 @@
+{
+ "vrfId":0,
+ "vrfName":"default",
+ "routerId":"203.0.113.49",
+ "defaultLocPrf":100,
+ "localAS":400,
+ "routes":{"0.0.0.0/0":[
+  {
+    "network":"0.0.0.0\/0",
+    "peerId":"192.0.2.49",
+    "path":"300",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"192.0.2.49",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+],"203.0.113.0/28":[
+  {
+    "network":"203.0.113.0\/28",
+    "peerId":"192.0.2.49",
+    "path":"300 100",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"192.0.2.49",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+],"203.0.113.16/28":[
+  {
+    "network":"203.0.113.16\/28",
+    "peerId":"192.0.2.49",
+    "path":"300",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"192.0.2.49",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+],"203.0.113.32/28":[
+  {
+    "network":"203.0.113.32\/28",
+    "peerId":"192.0.2.49",
+    "path":"300",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"192.0.2.49",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+],"203.0.113.48/28":[
+  {
+    "network":"203.0.113.48\/28",
+    "peerId":"(unspec)",
+    "path":"",
+    "origin":"IGP",
+    "nexthops":[
+      {
+        "ip":"0.0.0.0",
+        "afi":"ipv4",
+        "used":true
+      }
+    ]
+  }
+] } }

tests/topotests/bgp_confed1/r4/bgp_summary.json

@@ -0,0 +1,13 @@
+{
+    "ipv4Unicast":{
+    "routerId":"203.0.113.49",	
+    "as":400,
+    "peers":{
+      "192.0.2.49":{
+        "remoteAs":300,
+         "state":"Established",
+         "peerState":"OK"
+      }
+    }
+  }
+}

tests/topotests/bgp_confed1/r4/bgpd.conf

@@ -0,0 +1,14 @@
+debug bgp neighbor-events
+debug bgp nht
+debug bgp updates in
+debug bgp updates out
+!
+router bgp 400
+ no bgp ebgp-requires-policy
+ bgp disable-ebgp-connected-route-check
+!
+ neighbor 192.0.2.49 remote-as 300
+ address-family ipv4 unicast
+  network 203.0.113.48/28
+ exit-address-family
+!

tests/topotests/bgp_confed1/r4/zebra.conf

@@ -0,0 +1,6 @@
+interface r4-eth0
+ ip address 192.0.2.50/28
+!
+interface lo
+ ip address 203.0.113.49/28
+!

tests/topotests/bgp_confed1/test_bgp_confed1.py

@@ -0,0 +1,129 @@
+#!/usr/bin/env python
+
+#
+# test_bgp_confed1.py
+#
+# Copyright 2022 6WIND S.A.
+#
+# Permission to use, copy, modify, and/or distribute this software
+# for any purpose with or without fee is hereby granted, provided
+# that the above copyright notice and this permission notice appear
+# in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND 6WIND DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL 6WIND BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY
+# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+# OF THIS SOFTWARE.
+#
+
+"""
+test_bgp_confed1.py: Test the FRR BGP confederations with AS member
+same as confederation Id, verify BGP prefixes and path distribution  
+"""
+
+import os
+import sys
+import json
+from functools import partial
+import pytest
+
+# Save the Current Working Directory to find configuration files.
+CWD = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(CWD, "../"))
+
+# pylint: disable=C0413
+# Import topogen and topotest helpers
+from lib import topotest
+from lib.topogen import Topogen, TopoRouter, get_topogen
+from lib.topolog import logger
+
+pytestmark = [pytest.mark.bgpd]
+
+
+def build_topo(tgen):
+    for routern in range(1, 5):  
+        tgen.add_router("r{}".format(routern))
+
+    switch = tgen.add_switch("s1")
+    switch.add_link(tgen.gears["r1"])
+    switch.add_link(tgen.gears["r2"])
+
+    switch = tgen.add_switch("s3")
+    switch.add_link(tgen.gears["r3"])
+    switch.add_link(tgen.gears["r4"])
+
+    switch = tgen.add_switch("s2")
+    switch.add_link(tgen.gears["r2"])
+    switch.add_link(tgen.gears["r3"])
+
+def setup_module(mod):
+
+    tgen = Topogen(build_topo, mod.__name__)
+    tgen.start_topology()
+
+    router_list = tgen.routers()
+    for rname, router in router_list.items():
+        router.load_config(
+            TopoRouter.RD_ZEBRA, os.path.join(CWD, "{}/zebra.conf".format(rname))
+        )
+        router.load_config(
+            TopoRouter.RD_ISIS, os.path.join(CWD, "{}/isisd.conf".format(rname))
+        )
+        router.load_config(
+            TopoRouter.RD_BGP, os.path.join(CWD, "{}/bgpd.conf".format(rname))
+        )
+
+    # Initialize all routers.
+    tgen.start_router()
+
+def teardown_module(_mod):
+    "Teardown the pytest environment"
+    tgen = get_topogen()
+    tgen.stop_topology()
+
+
+def test_bgp_convergence():
+    "Assert that BGP is converging."
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info("waiting for bgp peers to go up")
+
+    for router in tgen.routers().values():
+        ref_file = "{}/{}/bgp_summary.json".format(CWD, router.name)
+        expected = json.loads(open(ref_file).read())
+        test_func = partial(
+            topotest.router_json_cmp, router, "show ip bgp summary json", expected
+        )
+        _, res = topotest.run_and_expect(test_func, None, count=125, wait=2.0)
+        assertmsg = "{}: bgp did not converge".format(router.name)
+        assert res is None, assertmsg
+
+
+def test_bgp_confed_ipv4_unicast():
+    "Assert that BGP is exchanging BGP route."
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info("waiting for bgp peers exchanging UPDATES")
+
+    for router in tgen.routers().values():
+        ref_file = "{}/{}/bgp_ipv4_unicast.json".format(CWD, router.name)
+        expected = json.loads(open(ref_file).read())
+        test_func = partial(
+            topotest.router_json_cmp, router, "show bgp ipv4 unicast json", expected
+        )
+        _, res = topotest.run_and_expect(test_func, None, count=40, wait=2.5)
+        assertmsg = "{}: BGP UPDATE exchange failure".format(router.name)
+        assert res is None, assertmsg
+
+
+if __name__ == "__main__":
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))