[ovs-dev] [PATCH 2/2] bfd: Require bfd control packet received in forwarding_if_rx mode.
Alex Wang
alexw at nicira.com
Mon Apr 28 06:03:54 UTC 2014
This commit adds a new configuration option "demand_rx_bfd" for bfd
which is equivalent to the 'demand_rx_ccm' of cfm and is to be used
in forwarding_if_rx mode.
Signed-off-by: Alex Wang <alexw at nicira.com>
---
lib/bfd.c | 43 ++++++++++++++++++++-----
tests/bfd.at | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++
vswitchd/vswitch.xml | 23 ++++++++++++++
3 files changed, 143 insertions(+), 8 deletions(-)
diff --git a/lib/bfd.c b/lib/bfd.c
index e3e3ae5..4966506 100644
--- a/lib/bfd.c
+++ b/lib/bfd.c
@@ -203,6 +203,14 @@ struct bfd {
bool forwarding_if_rx;
long long int forwarding_if_rx_detect_time;
+ /* When 'bfd->forwarding_if_rx' is set, users can specify the
+ * 'demand_rx_bfd' interval. If bfd control packet is not received
+ * within this interval, even if data packets are received, the
+ * bfd->forwarding will be false. The configured value should be at
+ * least 20 * bfd->cfg_min_rx. */
+ int demand_rx_bfd;
+ long long int demand_rx_bfd_time;
+
/* BFD decay related variables. */
bool in_decay; /* True when bfd is in decay. */
int decay_min_rx; /* min_rx is set to decay_min_rx when */
@@ -331,7 +339,7 @@ bfd_configure(struct bfd *bfd, const char *name, const struct smap *cfg,
static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
static atomic_uint16_t udp_src = ATOMIC_VAR_INIT(0);
- int decay_min_rx;
+ int decay_min_rx, demand_rx_bfd;
long long int min_tx, min_rx;
bool need_poll = false;
bool cfg_min_rx_changed = false;
@@ -464,6 +472,17 @@ bfd_configure(struct bfd *bfd, const char *name, const struct smap *cfg,
}
}
+ demand_rx_bfd = smap_get_int(cfg, "demand_rx_bfd", 0);
+ if (bfd->forwarding_if_rx) {
+ bfd->demand_rx_bfd = demand_rx_bfd ? MAX(demand_rx_bfd,
+ 20 * bfd->cfg_min_rx) : 0;
+ if (bfd->last_forwarding && bfd->demand_rx_bfd) {
+ bfd->demand_rx_bfd_time = time_msec() + bfd->demand_rx_bfd;
+ } else {
+ bfd->demand_rx_bfd_time = LLONG_MIN;
+ }
+ }
+
if (need_poll) {
bfd_poll(bfd);
}
@@ -841,6 +860,10 @@ bfd_process_packet(struct bfd *bfd, const struct flow *flow,
}
/* XXX: RFC 5880 Section 6.8.6 Demand mode related calculations here. */
+ if (bfd->forwarding_if_rx && bfd->demand_rx_bfd) {
+ bfd->demand_rx_bfd_time = time_msec() + bfd->demand_rx_bfd;
+ }
+
out:
bfd_forwarding__(bfd);
ovs_mutex_unlock(&mutex);
@@ -876,19 +899,23 @@ bfd_set_netdev(struct bfd *bfd, const struct netdev *netdev)
static bool
bfd_forwarding__(struct bfd *bfd) OVS_REQUIRES(mutex)
{
- long long int time;
+ long long int now = time_msec();
+ bool forwarding_if_rx;
bool last_forwarding = bfd->last_forwarding;
if (bfd->forwarding_override != -1) {
return bfd->forwarding_override == 1;
}
- time = bfd->forwarding_if_rx_detect_time;
- bfd->last_forwarding = (bfd->state == STATE_UP
- || (bfd->forwarding_if_rx && time > time_msec()))
- && bfd->rmt_diag != DIAG_PATH_DOWN
- && bfd->rmt_diag != DIAG_CPATH_DOWN
- && bfd->rmt_diag != DIAG_RCPATH_DOWN;
+ forwarding_if_rx = bfd->forwarding_if_rx
+ && bfd->forwarding_if_rx_detect_time > now
+ && (!bfd->demand_rx_bfd
+ || bfd->demand_rx_bfd_time > now);
+
+ bfd->last_forwarding = (bfd->state == STATE_UP || forwarding_if_rx)
+ && bfd->rmt_diag != DIAG_PATH_DOWN
+ && bfd->rmt_diag != DIAG_CPATH_DOWN
+ && bfd->rmt_diag != DIAG_RCPATH_DOWN;
if (bfd->last_forwarding != last_forwarding) {
bfd->flap_count++;
bfd_status_changed(bfd);
diff --git a/tests/bfd.at b/tests/bfd.at
index 3723d60..0065397 100644
--- a/tests/bfd.at
+++ b/tests/bfd.at
@@ -605,6 +605,91 @@ BFD_CHECK_RX([p0], [1000ms], [1000ms], [300ms])
AT_CHECK([ovs-vsctl del-br br1], [0], [ignore])
AT_CLEANUP
+# forwarding_if_rx Test4
+# Test4 is for testing the demand_rx_bfd feature.
+# bfd is enabled on both ends of the link.
+AT_SETUP([bfd - bfd forwarding_if_rx - demand_rx_bfd])
+OVS_VSWITCHD_START([add-br br1 -- set bridge br1 datapath-type=dummy -- \
+ add-port br1 p1 -- set Interface p1 type=patch \
+ options:peer=p0 ofport_request=2 -- \
+ add-port br0 p0 -- set Interface p0 type=patch \
+ options:peer=p1 ofport_request=1 -- \
+ set Interface p0 bfd:enable=true bfd:min_tx=300 bfd:min_rx=300 -- \
+ set Interface p1 bfd:enable=true bfd:min_tx=500 bfd:min_rx=500])
+
+ovs-appctl time/stop
+# advance the clock, to stablize the states.
+for i in `seq 0 19`; do ovs-appctl time/warp 500; done
+BFD_CHECK([p0], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
+BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [No Diagnostic])
+BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
+
+# enable forwarding_if_rx.
+AT_CHECK([ovs-vsctl set Interface p0 bfd:forwarding_if_rx=true], [0])
+# disable the bfd on p1.
+AT_CHECK([ovs-vsctl set Interface p1 bfd:enable=false], [0])
+
+# advance clock by 4000ms, while receiving packets.
+# the STATE should go DOWN, due to Control Detection Time Expired.
+# but forwarding flag should be still true.
+for i in `seq 0 7`
+do
+ ovs-appctl time/warp 500
+ AT_CHECK([ovs-ofctl packet-out br1 3 2 "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
+ [0], [stdout], [])
+done
+BFD_CHECK([p0], [true], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
+
+# now set the demand_rx_bfd to a 6000 (20 * bfd->cfg_min_rx) of p0.
+AT_CHECK([ovs-vsctl set Interface p0 bfd:demand_rx_bfd=6000])
+# advance clock by 8000ms, while receiving packets.
+# forwarding flag should go down since there is no bfd control packet
+# received during the demand_rx_bfd.
+for i in `seq 0 15`
+do
+ ovs-appctl time/warp 500
+ AT_CHECK([ovs-ofctl packet-out br1 3 2 "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
+ [0], [stdout], [])
+done
+BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
+
+# now enable the bfd on p1 again.
+AT_CHECK([ovs-vsctl set Interface p1 bfd:enable=true], [0])
+# advance clock by 5000ms. and p1 and p0 should be all up.
+for i in `seq 0 9`; do ovs-appctl time/warp 500; done
+BFD_CHECK([p0], [true], [false], [none], [up], [Control Detection Time Expired], [none], [up], [No Diagnostic])
+BFD_CHECK([p1], [true], [false], [none], [up], [No Diagnostic], [none], [up], [Control Detection Time Expired])
+BFD_CHECK_TX([p0], [500ms], [300ms], [500ms])
+
+# disable the bfd on p1 again.
+AT_CHECK([ovs-vsctl set Interface p1 bfd:enable=false], [0])
+# advance clock by 8000ms, while receiving packets.
+# forwarding flag should go down since there is no bfd control packet
+# received during the demand_rx_bfd.
+for i in `seq 0 15`
+do
+ ovs-appctl time/warp 500
+ AT_CHECK([ovs-ofctl packet-out br1 3 2 "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
+ [0], [stdout], [])
+done
+BFD_CHECK([p0], [false], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
+
+# now reset the demand_rx_bfd.
+AT_CHECK([ovs-vsctl remove Interface p0 bfd demand_rx_bfd=6000])
+# advance clock by 4000ms, while receiving packets.
+# the STATE should go DOWN, due to Control Detection Time Expired.
+# but forwarding flag should be still true.
+for i in `seq 0 7`
+do
+ ovs-appctl time/warp 500
+ AT_CHECK([ovs-ofctl packet-out br1 3 2 "90e2ba01475000101856b2e80806000108000604000100101856b2e80202020300000000000002020202"],
+ [0], [stdout], [])
+done
+BFD_CHECK([p0], [true], [false], [none], [down], [Control Detection Time Expired], [none], [down], [No Diagnostic])
+
+AT_CHECK([ovs-vsctl del-br br1], [0], [ignore])
+AT_CLEANUP
+
# test bfd:flap_count.
# This test contains three part:
# part 1. tests the flap_count on normal bfd monitored link.
diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
index 78ccd24..d20eceb 100644
--- a/vswitchd/vswitch.xml
+++ b/vswitchd/vswitch.xml
@@ -1974,6 +1974,29 @@
to be lost from marking the interface down.
</column>
+ <column name="bfd" key="demand_rx_bfd" type='{"type": "integer"}'>
+ <p>
+ A time interval in milliseconds. When set, must be greater than
+ twenty time of <ref column="bfd" key="min_rx"/>.
+ </p>
+
+ <p>
+ When configured and <ref column="bfd" key="forwarding_if_rx"/>
+ is true, the BFD session is required to receive at least one BFD
+ control packet during this interval. Otherwise, the
+ <ref column="bfd" key="forwarding"/> flag will be false even
+ though data packet is received from the monitored interface.
+ </p>
+
+ <p>
+ Since the datapath flow is not purged when the userspace Open Vswitch
+ crashes, data packet can still be forwarded through the tunnel and
+ fool the remote BFD session in <code>forwarding_if_rx</code> mode.
+ Thus, this option can prevent the remote BFD session from falsely
+ declaring tunnel liveness in this situation.
+ </p>
+ </column>
+
<column name="bfd" key="cpath_down" type='{"type": "boolean"}'>
Set to true to notify the remote endpoint that traffic should not be
forwarded to this system for some reason other than a connectivty
--
1.7.9.5
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