This change adds a 'bgp-mirror' option to LRP that allows
mirroring of BGP control plane traffic to an arbitrary LSP
in its peer LS.
The option expects a string with a LSP name. When set,
any traffic entering LS that's destined for any of the
LRP's IP addresses (including IPv6 LLA) is redirected
to the LSP specified in the option's value.
This enables external BGP daemons to listen on an interface
bound to a LSP and effectively act as if they were listening
on (and speaking from) LRP's IP address.
Signed-off-by: Martin Kalcok <martin.kal...@canonical.com>
---
northd/northd.c | 87
+++++++++++++++++++++++++++++++++++++++++
northd/ovn-northd.8.xml | 23 +++++++++++
ovn-nb.xml | 14 +++++++
tests/ovn-northd.at | 45 +++++++++++++++++++++
tests/system-ovn.at | 86
++++++++++++++++++++++++++++++++++++++++
5 files changed, 255 insertions(+)
diff --git a/northd/northd.c b/northd/northd.c
index 4353df07d..e07bf68cc 100644
--- a/northd/northd.c
+++ b/northd/northd.c
@@ -13048,6 +13048,92 @@
build_arp_resolve_flows_for_lrp(struct
ovn_port *op,
}
}
+static void
+build_bgp_redirect_rule__(
+ const char *s_addr, const char *bgp_port_name, bool
is_ipv6,
+ struct ovn_port *ls_peer, struct lflow_table
*lflows,
+ struct ds *match, struct ds *actions)
+{
+ int ip_ver = is_ipv6 ? 6 : 4;
+ /* Redirect packets in the input pipeline destined for
LR's IP to
+ * the port specified in 'bgp-mirror' option.
+ */
+ ds_clear(match);
+ ds_clear(actions);
+ ds_put_format(match, "ip%d.dst == %s && tcp.dst == 179",
ip_ver,
s_addr);
+ ds_put_format(actions, "outport = \"%s\"; output;",
bgp_port_name);
+ ovn_lflow_add(lflows, ls_peer->od, S_SWITCH_IN_L2_LKUP,
100,
+ ds_cstr(match),
+ ds_cstr(actions),
+ ls_peer->lflow_ref);
+
+
+ /* Drop any traffic originating from 'bgp-mirror' port
that does
+ * not originate from BGP daemon port. This blocks
unnecessary
+ * traffic like ARP broadcasts or IPv6 router
solicitation packets
+ * from the dummy 'bgp-mirror' port.
+ */
+ ds_clear(match);
+ ds_put_format(match, "inport == \"%s\"", bgp_port_name);
+ ovn_lflow_add(lflows, ls_peer->od,
S_SWITCH_IN_CHECK_PORT_SEC, 80,
+ ds_cstr(match),
+ REGBIT_PORT_SEC_DROP " = 1; next;",
+ ls_peer->lflow_ref);
+
+ ds_put_format(match,
+ " && ip%d.src == %s && tcp.src == 179",
+ ip_ver,
+ s_addr);
+ ovn_lflow_add(lflows, ls_peer->od,
S_SWITCH_IN_CHECK_PORT_SEC, 81,
+ ds_cstr(match),
+ REGBIT_PORT_SEC_DROP " =
check_in_port_sec(); next;",
+ ls_peer->lflow_ref);
+}
+
+static void
+build_lrouter_bgp_redirect(
+ struct ovn_port *op, struct lflow_table *lflows,
+ struct ds *match, struct ds *actions)
+{
+ /* LRP has to have a peer.*/
+ if (op->peer == NULL) {
+ return;
+ }
+ /* LRP has to have NB record.*/
+ if (op->nbrp == NULL) {
+ return;
+ }
+
+ /* Proceed only for LRPs that have 'bgp-mirror' option
set.
Value of this
+ * option is the name of LSP to which a BGP traffic will
be
mirrored.
+ */
+ const char *bgp_port = smap_get(&op->nbrp->options,
"bgp-mirror");
+ if (bgp_port == NULL) {
+ return;
+ }
+
+ if (op->cr_port != NULL) {
+ static struct vlog_rate_limit rl =
VLOG_RATE_LIMIT_INIT(1, 5);
+ VLOG_WARN_RL(&rl, "Option 'bgp-mirror' is not
supported on"
+ " Distributed Gateway Port '%s'",
op->key);
+ return;
+ }
+
+ /* Mirror traffic destined for LRP's IPs and default BGP
port
+ * to the port defined in 'bgp-mirror' option.
+ */
+ for (size_t i = 0; i < op->lrp_networks.n_ipv4_addrs;
i++) {
+ const char *ip_s = op-
lrp_networks.ipv4_addrs[i].addr_s;
+ build_bgp_redirect_rule__(ip_s, bgp_port, false, op-
peer,
lflows,
+ match, actions);
+ }
+ for (size_t i = 0; i < op->lrp_networks.n_ipv6_addrs;
i++) {
+ const char *ip_s = op-
lrp_networks.ipv6_addrs[i].addr_s;
+ build_bgp_redirect_rule__(ip_s, bgp_port, true, op-
peer,
lflows,
+ match, actions);
+ }
+}
+
/* This function adds ARP resolve flows related to a LSP.
*/
static void
build_arp_resolve_flows_for_lsp(
@@ -16003,6 +16089,7 @@
build_lswitch_and_lrouter_iterate_by_lrp(struct ovn_port *op,
lsi->meter_groups, op-
lflow_ref);
build_lrouter_icmp_packet_toobig_admin_flows(op, lsi-
lflows,
&lsi->match,
&lsi->actions, op->lflow_ref);
+ build_lrouter_bgp_redirect(op, lsi->lflows, &lsi->match,
&lsi->actions);
}
static void *
diff --git a/northd/ovn-northd.8.xml b/northd/ovn-
northd.8.xml
index b06b09ac5..1bf9d2dc0 100644
--- a/northd/ovn-northd.8.xml
+++ b/northd/ovn-northd.8.xml
@@ -284,6 +284,21 @@
dropped in the next stage.
</li>
+ <li>
+ For each logical port that's defined as a target of
BGP
mirroring (via
+ <code>bgp-mirror</code> option set on Logical Router
Port),
a filter is
+ set in place that disallows any traffic entering
this port
that does
+ not originate from Logical Router Port's IPs and
default BGP
port (
+ TCP 179). This filtering is achieved by two rules.
First
rule has
+ priority 81, it matches on <code>inport ==
<var>BGP_MIRROR_PORT</var>
+ && ip.src == <var>LRP_IP</var> &&
tcp.src ==
179</code>
+ and allows traffic further with
<code>REGBIT_PORT_SEC_DROP" =
+ check_in_port_sec(); next;</code>. Second rule with
priority
80 matches
+ the rest of the traffic from that port and sets
+ <code>REGBIT_PORT_SEC_DROP" = 1; next;"</code> so
that the
packets are
+ dropped in the next stage.
+ </li>
+
<li>
For each (enabled) vtep logical port, a priority
70 flow is
added which
matches on all packets and applies the action
@@ -1949,6 +1964,14 @@ output;
on the logical switch.
</li>
+ <li>
+ For any logical port that's defined as a target of
BGP
mirroring (via
+ <code>bgp-mirror</code> option set on Logical Router
Port), a
+ priority-100 flow is added that redirects traffic
for
Logical Router
+ Port IPs (including IPv6 LLA) and TCP port 179, to
the targeted
+ logical port.
+ </li>
+
<li>
Priority-90 flows for transit switches that
forward registered
IP multicast traffic to their corresponding
multicast group
, which
diff --git a/ovn-nb.xml b/ovn-nb.xml
index 9552534f6..44d3591db 100644
--- a/ovn-nb.xml
+++ b/ovn-nb.xml
@@ -3440,6 +3440,20 @@ or
</p>
</column>
+ <column name="options" key="bgp-mirror"
type='{"type":
"string"}'>
+ <p>
+ This option expects a name of a Logical Switch
Port that's
present
+ in the peer's Logical Switch. If set, it causes
any traffic
+ that's destined for Logical Router Port's IP
addresses
(including
+ its IPv6 LLA) and the default BGP port (TCP 179),
to be
mirrored
+ to the specified Logical Switch Port.
+
+ This allows external BGP daemon to be bound to a
port in
OVN's
+ Logical Switch and act as if it was listening on
Logical
Router
+ Port's IP address.
+ </p>
+ </column>
+
<column name="options" key="gateway_mtu_bypass">
<p>
When configured, represents a match expression,
in the same
diff --git a/tests/ovn-northd.at b/tests/ovn-northd.at
index a389d1988..0c58066f6 100644
--- a/tests/ovn-northd.at
+++ b/tests/ovn-northd.at
@@ -12721,3 +12721,48 @@ AT_CHECK([ovn-sbctl dump-flows lr |
grep
lr_in_dnat | ovn_strip_lflows], [0], [d
AT_CLEANUP
])
+
+OVN_FOR_EACH_NORTHD_NO_HV([
+AT_SETUP([BGP control plane mirroring])
+ovn_start
+
+check ovn-sbctl chassis-add hv1 geneve 127.0.0.1
+
+check ovn-nbctl lr-add lr -- \
+ lrp-add lr lr-ls 02:ac:10:01:00:01 172.16.1.1/24
+check ovn-nbctl --wait=sb set logical_router lr
options:chassis=hv1
+
+check ovn-nbctl ls-add ls -- \
+ lsp-add ls ls-lr -- \
+ lsp-set-type ls-lr router -- \
+ lsp-set-addresses ls-lr router -- \
+ lsp-set-options ls-lr router-port=lr-ls
+
+check ovn-nbctl lsp-add ls lsp-bgp -- \
+ lsp-set-addresses lsp-bgp unknown
+
+# By default, no rules related to BGP mirroring are present
+AT_CHECK([ovn-sbctl dump-flows ls | grep ls_in_l2_lkup |
grep
"tcp.dst == 179" | wc -l], [0], [0
+])
+
+AT_CHECK([ovn-sbctl dump-flows ls | grep
ls_in_check_port_sec | grep
-E "priority=80|priority=81" | wc -l], [0], [0
+])
+
+# Set "lsp-bgp" port as target of BGP control plane mirrored
traffic
+check ovn-nbctl --wait=sb set logical_router_port lr-ls
options:bgp-mirror=lsp-bgp
+
+# Check that BGP control plane traffic is redirected to
"lsp-bgp"
+AT_CHECK([ovn-sbctl dump-flows ls | grep ls_in_l2_lkup |
grep
"tcp.dst == 179" | ovn_strip_lflows], [0], [dnl
+ table=??(ls_in_l2_lkup ), priority=100 ,
match=(ip4.dst ==
172.16.1.1 && tcp.dst == 179), action=(outport = "lsp-bgp";
output;)
+ table=??(ls_in_l2_lkup ), priority=100 ,
match=(ip6.dst ==
fe80::ac:10ff:fe01:1 && tcp.dst == 179), action=(outport =
"lsp-bgp";
output;)
+])
+
+# Check that only BGP-related traffic is accepted on "lsp-
bgp" port
+AT_CHECK([ovn-sbctl dump-flows ls | grep
ls_in_check_port_sec | grep
-E "priority=80|priority=81" | ovn_strip_lflows], [0], [dnl
+ table=??(ls_in_check_port_sec), priority=80 ,
match=(inport ==
"lsp-bgp"), action=(reg0[[15]] = 1; next;)
+ table=??(ls_in_check_port_sec), priority=81 ,
match=(inport ==
"lsp-bgp" && ip4.src == 172.16.1.1 && tcp.src == 179),
action=(reg0[[15]] = check_in_port_sec(); next;)
+ table=??(ls_in_check_port_sec), priority=81 ,
match=(inport ==
"lsp-bgp" && ip6.src == fe80::ac:10ff:fe01:1 && tcp.src ==
179),
action=(reg0[[15]] = check_in_port_sec(); next;)
+])
+
+AT_CLEANUP
+])
diff --git a/tests/system-ovn.at b/tests/system-ovn.at
index c24ede7c5..fbcb05e59 100644
--- a/tests/system-ovn.at
+++ b/tests/system-ovn.at
@@ -13027,3 +13027,89 @@ OVS_TRAFFIC_VSWITCHD_STOP(["/failed
to query
port patch-.*/d
/connection dropped.*/d"])
AT_CLEANUP
])
+
+OVN_FOR_EACH_NORTHD([
+AT_SETUP([BGP control plane mirroring])
+ovn_start
+OVS_TRAFFIC_VSWITCHD_START()
+
+ADD_BR([br-int])
+ADD_BR([br-ext])
+
+ovs-ofctl add-flow br-ext action=normal
+# Set external-ids in br-int needed for ovn-controller
+ovs-vsctl \
+ -- set Open_vSwitch . external-ids:system-id=hv1 \
+ -- set Open_vSwitch .
external-ids:ovn-remote=unix:$ovs_base/ovn-sb/ovn-sb.sock \
+ -- set Open_vSwitch . external-ids:ovn-encap-
type=geneve \
+ -- set Open_vSwitch . external-ids:ovn-encap-
ip=169.0.0.1 \
+ -- set bridge br-int fail-mode=secure
other-config:disable-in-band=true
+
+# Start ovn-controller
+start_daemon ovn-controller
+
+ovn-nbctl lr-add R1 \
+ -- set Logical_Router R1 options:chassis=hv1
+
+ovn-nbctl ls-add public
+
+ovn-nbctl lrp-add R1 rp-public 00:00:02:01:02:03
172.16.1.1/24
+
+ovn-nbctl lsp-add public public-rp -- set
Logical_Switch_Port
public-rp \
+ type=router options:router-port=rp-public \
+ -- lsp-set-addresses public-rp router
+
+ovn-nbctl lsp-add public bgp-daemon \
+ -- lsp-set-addresses bgp-daemon unknown
+
+AT_CHECK([ovs-vsctl set Open_vSwitch .
external-ids:ovn-bridge-mappings=phynet:br-ext])
+ovn-nbctl lsp-add public public1 \
+ -- lsp-set-addresses public1 unknown \
+ -- lsp-set-type public1 localnet \
+ -- lsp-set-options public1 network_name=phynet
+
+ovn-nbctl --wait=hv sync
+
+# Set option that redirects BGP control plane traffic to a
LSP
"bgp-daemon"
+ovn-nbctl --wait=sb set logical_router_port rp-public
options:bgp-mirror=bgp-daemon
+
+# Create "bgp-daemon" interface in a namespace with IP and
MAC
matching LRP "rp-public"
+ADD_NAMESPACES(bgp-daemon)
+ADD_VETH(bgp-daemon, bgp-daemon, br-int, "172.16.1.1/24",
"00:00:02:01:02:03")
+
+ADD_NAMESPACES(ext-foo)
+ADD_VETH(ext-foo, ext-foo, br-ext, "172.16.1.100/24",
"00:10:10:01:02:13", \
+ "172.16.1.1")
+
+# Flip the interface down/up to get proper IPv6 LLA
+NS_EXEC([bgp-daemon], [ip link set down bgp-daemon])
+NS_EXEC([bgp-daemon], [ip link set up bgp-daemon])
+
+# Wait until IPv6 LLA loses the "tentative" flag otherwise
it can't
be bound to.
+OVS_WAIT_UNTIL([NS_EXEC([bgp-daemon], [ip a show dev bgp-
daemon |
grep "fe80::" | grep -v tentative])])
+OVS_WAIT_UNTIL([NS_EXEC([ext-foo], [ip a show dev ext-foo |
grep
"fe80::" | grep -v tentative])])
+
+# Verify that BGP control plane traffic is delivered to the
"bgp-daemon"
+# interface on both IPv4 and IPv6 LLA addresses
+NETNS_DAEMONIZE([bgp-daemon], [nc -l -k 172.16.1.1 179],
[bgp_v4.pid])
+NS_CHECK_EXEC([ext-foo], [echo "TCP test" | nc --send-only
172.16.1.1 179])
+
+NETNS_DAEMONIZE([bgp-daemon], [nc -l -6 -k
fe80::200:2ff:fe01:203%bgp-daemon 179], [bgp_v6.pid])
+NS_CHECK_EXEC([ext-foo], [echo "TCP test" | nc --send-only -
6
fe80::200:2ff:fe01:203%ext-foo 179])
+
+OVS_APP_EXIT_AND_WAIT([ovn-controller])
+
+as ovn-sb
+OVS_APP_EXIT_AND_WAIT([ovsdb-server])
+
+as ovn-nb
+OVS_APP_EXIT_AND_WAIT([ovsdb-server])
+
+as northd
+OVS_APP_EXIT_AND_WAIT([ovn-northd])
+
+as
+OVS_TRAFFIC_VSWITCHD_STOP(["/.*error receiving.*/d
+/.*terminating with signal 15.*/d"])
+AT_CLEANUP
+])
