Merge pull request #7748 from adrianomarto/bgp-listen-on-multiple-addresses

BGP daemon listen for connections on multiple addresses

bgpd/bgp_main.c

@@ -253,6 +253,7 @@ static __attribute__((__noreturn__)) void bgp_exit(int status)
 
 	bf_free(bm->rd_idspace);
 	list_delete(&bm->bgp);
+	list_delete(&bm->addresses);
 
 	bgp_lp_finish();
 
@@ -404,12 +405,16 @@ int main(int argc, char **argv)
 	int tmp_port;
 
 	int bgp_port = BGP_PORT_DEFAULT;
-	char *bgp_address = NULL;
+	struct list *addresses = list_new();
 	int no_fib_flag = 0;
 	int no_zebra_flag = 0;
 	int skip_runas = 0;
 	int instance = 0;
 	int buffer_size = BGP_SOCKET_SNDBUF_SIZE;
+	char *address;
+	struct listnode *node;
+
+	addresses->cmp = (int (*)(void *, void *))strcmp;
 
 	frr_preinit(&bgpd_di, argc, argv);
 	frr_opt_add(
@@ -463,7 +468,7 @@ int main(int argc, char **argv)
 			break;
 		}
 		case 'l':
-			bgp_address = optarg;
+			listnode_add_sort_nodup(addresses, optarg);
 		/* listenon implies -n */
 		/* fallthru */
 		case 'n':
@@ -493,11 +498,10 @@ int main(int argc, char **argv)
 		memset(&bgpd_privs, 0, sizeof(bgpd_privs));
 
 	/* BGP master init. */
-	bgp_master_init(frr_init(), buffer_size);
+	bgp_master_init(frr_init(), buffer_size, addresses);
 	bm->port = bgp_port;
 	if (bgp_port == 0)
 		bgp_option_set(BGP_OPT_NO_LISTEN);
-	bm->address = bgp_address;
 	if (no_fib_flag || no_zebra_flag)
 		bgp_option_set(BGP_OPT_NO_FIB);
 	if (no_zebra_flag)
@@ -513,8 +517,16 @@ int main(int argc, char **argv)
 	/* BGP related initialization.  */
 	bgp_init((unsigned short)instance);
 
-	snprintf(bgpd_di.startinfo, sizeof(bgpd_di.startinfo), ", bgp@%s:%d",
+	if (list_isempty(bm->addresses)) {
-		 (bm->address ? bm->address : "<all>"), bm->port);
+		snprintf(bgpd_di.startinfo, sizeof(bgpd_di.startinfo),
+			 ", bgp@<all>:%d", bm->port);
+	} else {
+		for (ALL_LIST_ELEMENTS_RO(bm->addresses, node, address))
+			snprintf(bgpd_di.startinfo + strlen(bgpd_di.startinfo),
+				 sizeof(bgpd_di.startinfo)
+					 - strlen(bgpd_di.startinfo),
+				 ", bgp@%s:%d", address, bm->port);
+	}
 
 	frr_config_fork();
 	/* must be called after fork() */

bgpd/bgpd.c

@@ -121,12 +121,20 @@ extern struct zclient *zclient;
 static int bgp_check_main_socket(bool create, struct bgp *bgp)
 {
 	static int bgp_server_main_created;
+	struct listnode *node;
+	char *address;
 
 	if (create) {
 		if (bgp_server_main_created)
 			return 0;
-		if (bgp_socket(bgp, bm->port, bm->address) < 0)
+		if (list_isempty(bm->addresses)) {
+			if (bgp_socket(bgp, bm->port, NULL) < 0)
 				return BGP_ERR_INVALID_VALUE;
+		} else {
+			for (ALL_LIST_ELEMENTS_RO(bm->addresses, node, address))
+				if (bgp_socket(bgp, bm->port, address) < 0)
+					return BGP_ERR_INVALID_VALUE;
+		}
 		bgp_server_main_created = 1;
 		return 0;
 	}
@@ -3288,7 +3296,8 @@ struct bgp *bgp_get_evpn(void)
 int bgp_handle_socket(struct bgp *bgp, struct vrf *vrf, vrf_id_t old_vrf_id,
 		      bool create)
 {
-	int ret = 0;
+	struct listnode *node;
+	char *address;
 
 	/* Create BGP server socket, if listen mode not disabled */
 	if (!bgp || bgp_option_check(BGP_OPT_NO_LISTEN))
@@ -3317,9 +3326,14 @@ int bgp_handle_socket(struct bgp *bgp, struct vrf *vrf, vrf_id_t old_vrf_id,
 		 */
 		if (vrf->vrf_id == VRF_UNKNOWN)
 			return 0;
-		ret = bgp_socket(bgp, bm->port, bm->address);
+		if (list_isempty(bm->addresses)) {
-		if (ret < 0)
+			if (bgp_socket(bgp, bm->port, NULL) < 0)
 				return BGP_ERR_INVALID_VALUE;
+		} else {
+			for (ALL_LIST_ELEMENTS_RO(bm->addresses, node, address))
+				if (bgp_socket(bgp, bm->port, address) < 0)
+					return BGP_ERR_INVALID_VALUE;
+		}
 		return 0;
 	} else
 		return bgp_check_main_socket(create, bgp);
@@ -7445,7 +7459,8 @@ char *peer_uptime(time_t uptime2, char *buf, size_t len, bool use_json,
 	return buf;
 }
 
-void bgp_master_init(struct thread_master *master, const int buffer_size)
+void bgp_master_init(struct thread_master *master, const int buffer_size,
+		     struct list *addresses)
 {
 	qobj_init();
 
@@ -7455,6 +7470,7 @@ void bgp_master_init(struct thread_master *master, const int buffer_size)
 	bm->bgp = list_new();
 	bm->listen_sockets = list_new();
 	bm->port = BGP_PORT_DEFAULT;
+	bm->addresses = addresses;
 	bm->master = master;
 	bm->start_time = bgp_clock();
 	bm->t_rmap_update = NULL;

bgpd/bgpd.h

@@ -125,8 +125,8 @@ struct bgp_master {
 	/* BGP port number.  */
 	uint16_t port;
 
-	/* Listener address */
+	/* Listener addresses */
-	char *address;
+	struct list *addresses;
 
 	/* The Mac table */
 	struct hash *self_mac_hash;
@@ -1872,8 +1872,8 @@ extern char *peer_uptime(time_t uptime2, char *buf, size_t len, bool use_json,
 
 extern int bgp_config_write(struct vty *);
 
-extern void bgp_master_init(struct thread_master *master,
+extern void bgp_master_init(struct thread_master *master, const int buffer_size,
-			    const int buffer_size);
+			    struct list *addresses);
 
 extern void bgp_init(unsigned short instance);
 extern void bgp_pthreads_run(void);

doc/user/bgp.rst

@@ -31,12 +31,23 @@ be specified (:ref:`common-invocation-options`).
 
 .. option:: -l, --listenon
 
-   Specify a specific IP address for bgpd to listen on, rather than its default
+   Specify specific IP addresses for bgpd to listen on, rather than its default
    of ``0.0.0.0`` / ``::``. This can be useful to constrain bgpd to an internal
-   address, or to run multiple bgpd processes on one host.
+   address, or to run multiple bgpd processes on one host. Multiple addresses
+   can be specified.
+
+   In the following example, bgpd is started listening for connections on the
+   addresses 100.0.1.2 and fd00::2:2. The options -d (runs in daemon mode) and
+   -f (uses specific configuration file) are also used in this example as we
+   are likely to run multiple bgpd instances, each one with different
+   configurations, when using -l option.
 
    Note that this option implies the --no_kernel option, and no learned routes will be installed into the linux kernel.
 
+.. code-block:: shell
+
+   # /usr/lib/frr/bgpd -d -f /some-folder/bgpd.conf -l 100.0.1.2 -l fd00::2:2
+
 .. option:: -n, --no_kernel
 
    Do not install learned routes into the linux kernel.  This option is useful

tests/bgpd/test_aspath.c

@@ -1265,7 +1265,8 @@ int main(void)
 {
 	int i = 0;
 	qobj_init();
-	bgp_master_init(thread_master_create(NULL), BGP_SOCKET_SNDBUF_SIZE);
+	bgp_master_init(thread_master_create(NULL), BGP_SOCKET_SNDBUF_SIZE,
+			list_new());
 	master = bm->master;
 	bgp_option_set(BGP_OPT_NO_LISTEN);
 	bgp_attr_init();

tests/bgpd/test_capability.c

@@ -912,7 +912,7 @@ int main(void)
 
 	qobj_init();
 	master = thread_master_create(NULL);
-	bgp_master_init(master, BGP_SOCKET_SNDBUF_SIZE);
+	bgp_master_init(master, BGP_SOCKET_SNDBUF_SIZE, list_new());
 	vrf_init(NULL, NULL, NULL, NULL, NULL);
 	bgp_option_set(BGP_OPT_NO_LISTEN);
 

tests/bgpd/test_mp_attr.c

@@ -1086,7 +1086,7 @@ int main(void)
 	cmd_init(0);
 	bgp_vty_init();
 	master = thread_master_create("test mp attr");
-	bgp_master_init(master, BGP_SOCKET_SNDBUF_SIZE);
+	bgp_master_init(master, BGP_SOCKET_SNDBUF_SIZE, list_new());
 	vrf_init(NULL, NULL, NULL, NULL, NULL);
 	bgp_option_set(BGP_OPT_NO_LISTEN);
 	bgp_attr_init();

tests/bgpd/test_mpath.c

@@ -393,7 +393,7 @@ static int global_test_init(void)
 	qobj_init();
 	master = thread_master_create(NULL);
 	zclient = zclient_new(master, &zclient_options_default);
-	bgp_master_init(master, BGP_SOCKET_SNDBUF_SIZE);
+	bgp_master_init(master, BGP_SOCKET_SNDBUF_SIZE, list_new());
 	vrf_init(NULL, NULL, NULL, NULL, NULL);
 	bgp_option_set(BGP_OPT_NO_LISTEN);
 

tests/bgpd/test_packet.c

@@ -59,7 +59,7 @@ int main(int argc, char *argv[])
 	qobj_init();
 	bgp_attr_init();
 	master = thread_master_create(NULL);
-	bgp_master_init(master, BGP_SOCKET_SNDBUF_SIZE);
+	bgp_master_init(master, BGP_SOCKET_SNDBUF_SIZE, list_new());
 	vrf_init(NULL, NULL, NULL, NULL, NULL);
 	bgp_option_set(BGP_OPT_NO_LISTEN);
 

tests/bgpd/test_peer_attr.c

@@ -1399,7 +1399,7 @@ static void bgp_startup(void)
 	master = thread_master_create(NULL);
 	yang_init(true);
 	nb_init(master, bgpd_yang_modules, array_size(bgpd_yang_modules), false);
-	bgp_master_init(master, BGP_SOCKET_SNDBUF_SIZE);
+	bgp_master_init(master, BGP_SOCKET_SNDBUF_SIZE, list_new());
 	bgp_option_set(BGP_OPT_NO_LISTEN);
 	vrf_init(NULL, NULL, NULL, NULL, NULL);
 	frr_pthread_init();

tests/topotests/bgp_listen_on_multiple_addresses/bgp_listen_on_multiple_addresses.json

@@ -0,0 +1,154 @@
+{
+    "ipv4base": "10.0.0.0",
+    "ipv4mask": 24,
+    "ipv6base": "fd00::",
+    "ipv6mask": 64,
+    "link_ip_start": {
+        "ipv4": "10.0.0.0",
+        "v4mask": 24,
+        "ipv6": "fd00::",
+        "v6mask": 64
+    },
+    "lo_prefix": {
+        "ipv4": "1.0.",
+        "v4mask": 32,
+        "ipv6": "2001:DB8:F::",
+        "v6mask": 128
+    },
+    "routers": {
+        "r1": {
+            "links": {
+                "lo": {
+                    "ipv4": "auto",
+                    "ipv6": "auto",
+                    "type": "loopback"
+                },
+                "r2": {
+                    "ipv4": "auto",
+                    "ipv6": "auto"
+                }
+            },
+            "bgp": {
+	                "local_as": "1000",
+	                "address_family": {
+	                    "ipv4": {
+	                        "unicast": {
+	                            "neighbor": {
+	                                "r2": {
+	                                    "dest_link": {
+	                                        "r1": {}
+	                                    }
+	                                }
+	                            }
+	                        }
+	                    }
+	                }
+	            }
+        },
+        "r2": {
+            "links": {
+                "lo": {
+                    "ipv4": "auto",
+                    "ipv6": "auto",
+                    "type": "loopback"
+                },
+                "r1": {
+                    "ipv4": "auto",
+                    "ipv6": "auto"
+                },
+                "r3": {
+                    "ipv4": "auto",
+                    "ipv6": "auto"
+                }
+            },
+            "bgp": {
+                "local_as": "2000",
+                "address_family": {
+                    "ipv4": {
+                        "unicast": {
+                            "neighbor": {
+                                "r1": {
+                                    "dest_link": {
+                                        "r2": {}
+                                    }
+                                },
+                                "r3": {
+                                    "dest_link": {
+                                        "r2": {}
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+	    },
+        "r3": {
+            "links": {
+                "lo": {
+                    "ipv4": "auto",
+                    "ipv6": "auto",
+                    "type": "loopback"
+                },
+                "r2": {
+                    "ipv4": "auto",
+                    "ipv6": "auto"
+                },
+                "r4": {
+                    "ipv4": "auto",
+                    "ipv6": "auto"
+                }
+            },
+            "bgp": {
+                "local_as": "2000",
+                "address_family": {
+                    "ipv4": {
+                        "unicast": {
+                            "neighbor": {
+                                "r2": {
+                                    "dest_link": {
+                                        "r3": {}
+                                    }
+                                },
+                                "r4": {
+                                    "dest_link": {
+                                        "r3": {}
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        },
+        "r4": {
+            "links": {
+                "lo": {
+                    "ipv4": "auto",
+                    "ipv6": "auto",
+                    "type": "loopback"
+                },
+                "r3": {
+                    "ipv4": "auto",
+                    "ipv6": "auto"
+                }
+            },
+            "bgp": {
+                "local_as": "3000",
+                "address_family": {
+                    "ipv4": {
+                        "unicast": {
+                            "neighbor": {
+                                "r3": {
+                                    "dest_link": {
+                                        "r4": {}
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

tests/topotests/bgp_listen_on_multiple_addresses/test_bgp_listen_on_multiple_addresses.py

@@ -0,0 +1,160 @@
+#!/usr/bin/env python
+
+#
+# test_bgp_listen_on_multiple_addresses.py
+# Part of NetDEF Topology Tests
+#
+# Copyright (c) 2021 by Boeing Defence Australia
+# Adriano Marto Reis
+#
+# 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 NETDEF DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NETDEF 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_listen_on_multiple_addresses.py: Test BGP daemon listening for
+connections on multiple addresses.
+
+    +------+        +------+        +------+        +------+
+    |      |        |      |        |      |        |      |
+    |  r1  |--------|  r2  |--------|  r3  |--------|  r4  |
+    |      |        |      |        |      |        |      |
+    +------+        +------+        +------+        +------+
+
+  |            |                                |             |
+  |  AS 1000   |            AS 2000             |   AS 3000   |
+  |            |                                |             |
+  +------------+--------------------------------+-------------+
+"""
+
+import os
+import sys
+import json
+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, "../"))
+
+from lib.topogen import Topogen, get_topogen
+from lib.topojson import build_topo_from_json, build_config_from_json
+from lib.common_config import start_topology
+from lib.topotest import router_json_cmp, run_and_expect
+from mininet.topo import Topo
+from functools import partial
+
+
+LISTEN_ADDRESSES = {
+    "r1": ["10.0.0.1"],
+    "r2": ["10.0.0.2", "10.0.1.1"],
+    "r3": ["10.0.1.2", "10.0.2.1"],
+    "r4": ["10.0.2.2"],
+}
+
+
+# Reads data from JSON File for topology and configuration creation.
+jsonFile = "{}/bgp_listen_on_multiple_addresses.json".format(CWD)
+try:
+    with open(jsonFile, "r") as topoJson:
+        topo = json.load(topoJson)
+except IOError:
+    assert False, "Could not read file {}".format(jsonFile)
+
+
+class TemplateTopo(Topo):
+    "Topology builder."
+
+    def build(self, *_args, **_opts):
+        "Defines the allocation and relationship between routers and switches."
+        tgen = get_topogen(self)
+        build_topo_from_json(tgen, topo)
+
+
+def setup_module(mod):
+    "Sets up the test environment."
+    tgen = Topogen(TemplateTopo, mod.__name__)
+
+    # Adds extra parameters to bgpd so they listen for connections on specific
+    # multiple addresses.
+    for router_name in tgen.routers().keys():
+        tgen.net[router_name].daemons_options["bgpd"] = "-l " + " -l ".join(
+            LISTEN_ADDRESSES[router_name]
+        )
+
+    start_topology(tgen)
+    build_config_from_json(tgen, topo)
+
+
+def teardown_module(_mod):
+    "Tears-down the test environment."
+    tgen = get_topogen()
+    tgen.stop_topology()
+
+
+def test_peering():
+    "Checks if the routers peer-up."
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    _bgp_converge_initial("r1", "10.0.0.2")
+    _bgp_converge_initial("r2", "10.0.0.1")
+    _bgp_converge_initial("r2", "10.0.1.2")
+    _bgp_converge_initial("r3", "10.0.1.1")
+    _bgp_converge_initial("r3", "10.0.2.2")
+    _bgp_converge_initial("r4", "10.0.2.1")
+
+
+def test_listening_address():
+    """
+    Checks if bgpd is only listening on the specified IP addresses.
+    """
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    for router in tgen.routers().values():
+        # bgpd must not be listening on the default address.
+        output = router.run("netstat -nlt4 | grep 0.0.0.0:179")
+        assert output == "", "{}: bpgd is listening on 0.0.0.0:179".format(router.name)
+
+        # bgpd must be listening on the specified addresses.
+        for address in LISTEN_ADDRESSES[router.name]:
+            output = router.run("netstat -nlt4 | grep {}:179".format(address))
+            assert output != "", "{}: bpgd is not listening on {}:179".format(
+                router.name, address
+            )
+
+
+def _bgp_converge_initial(router_name, peer_address, timeout=180):
+    """
+    Waits for the BGP connection between a given router and a given peer
+    (specified by its IP address) to be established. If the connection is
+    not established within a given timeout, then an exception is raised. 
+    """
+    tgen = get_topogen()
+    router = tgen.routers()[router_name]
+    expected = {"ipv4Unicast": {"peers": {peer_address: {"state": "Established"}}}}
+
+    test_func = partial(router_json_cmp, router, "show ip bgp summary json", expected)
+    _, result = run_and_expect(test_func, None, count=timeout, wait=1)
+    assert result is None, "{}: Failed to establish connection with {}".format(
+        router_name, peer_address
+    )
+
+
+if __name__ == "__main__":
+    args = ["-s"] + sys.argv[1:]
+    sys.exit(pytest.main(args))