[ovs-dev] [PATCH] cfm: Support random VLAN tag for CCM PDUs.
Ethan Jackson
ethan at nicira.com
Sat Mar 17 01:05:21 UTC 2012
CCM PDUs may take a different path through the network depending on
the VLAN tag they carry. In order to exercise these paths, it
may be advantageous to use a random VLAN tag.
Signed-off-by: Ethan Jackson <ethan at nicira.com>
---
lib/cfm.c | 13 +++++++++----
lib/cfm.h | 3 ++-
vswitchd/bridge.c | 13 +++++++++++--
vswitchd/vswitch.xml | 3 ++-
4 files changed, 24 insertions(+), 8 deletions(-)
diff --git a/lib/cfm.c b/lib/cfm.c
index 8d90829..10a9428 100644
--- a/lib/cfm.c
+++ b/lib/cfm.c
@@ -30,6 +30,7 @@
#include "ofpbuf.h"
#include "packets.h"
#include "poll-loop.h"
+#include "random.h"
#include "timer.h"
#include "timeval.h"
#include "unixctl.h"
@@ -96,7 +97,7 @@ struct cfm {
uint32_t seq; /* The sequence number of our last CCM. */
uint8_t ccm_interval; /* The CCM transmission interval. */
int ccm_interval_ms; /* 'ccm_interval' in milliseconds. */
- uint16_t ccm_vlan; /* Vlan tag of CCM PDUs. */
+ uint16_t ccm_vlan; /* Vlan tag of CCM PDUs. UINT16_MAX if random. */
uint8_t ccm_pcp; /* Priority of CCM PDUs. */
uint8_t maid[CCM_MAID_LEN]; /* The MAID of this CFM. */
@@ -391,13 +392,17 @@ void
cfm_compose_ccm(struct cfm *cfm, struct ofpbuf *packet,
uint8_t eth_src[ETH_ADDR_LEN])
{
+ uint16_t ccm_vlan;
struct ccm *ccm;
timer_set_duration(&cfm->tx_timer, cfm->ccm_interval_ms);
eth_compose(packet, cfm_ccm_addr(cfm), eth_src, ETH_TYPE_CFM, sizeof *ccm);
- if (cfm->ccm_vlan || cfm->ccm_pcp) {
- uint16_t tci = cfm->ccm_vlan | (cfm->ccm_pcp << VLAN_PCP_SHIFT);
+ ccm_vlan = cfm->ccm_vlan != UINT16_MAX ? cfm->ccm_vlan : random_uint16();
+ ccm_vlan = ccm_vlan & VLAN_VID_MASK;
+
+ if (ccm_vlan || cfm->ccm_pcp) {
+ uint16_t tci = ccm_vlan | (cfm->ccm_pcp << VLAN_PCP_SHIFT);
eth_push_vlan(packet, htons(tci));
}
@@ -455,7 +460,7 @@ cfm_configure(struct cfm *cfm, const struct cfm_settings *s)
interval = ms_to_ccm_interval(s->interval);
interval_ms = ccm_interval_to_ms(interval);
- cfm->ccm_vlan = s->ccm_vlan & VLAN_VID_MASK;
+ cfm->ccm_vlan = s->ccm_vlan;
cfm->ccm_pcp = s->ccm_pcp & (VLAN_PCP_MASK >> VLAN_PCP_SHIFT);
if (cfm->extended && interval_ms != s->interval) {
interval = 0;
diff --git a/lib/cfm.h b/lib/cfm.h
index 6d23293..c706c70 100644
--- a/lib/cfm.h
+++ b/lib/cfm.h
@@ -51,7 +51,8 @@ struct cfm_settings {
int interval; /* The requested transmission interval. */
bool extended; /* Run in extended mode. */
bool opup; /* Operational State. */
- uint16_t ccm_vlan; /* CCM Vlan tag. Zero if none. */
+ uint16_t ccm_vlan; /* CCM Vlan tag. Zero if none.
+ UINT16_MAX if random. */
uint8_t ccm_pcp; /* CCM Priority. Zero if none. */
};
diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
index 4761cbf..64d7c4d 100644
--- a/vswitchd/bridge.c
+++ b/vswitchd/bridge.c
@@ -3226,6 +3226,7 @@ iface_configure_cfm(struct iface *iface)
{
const struct ovsrec_interface *cfg = iface->cfg;
const char *extended_str, *opstate_str;
+ const char *cfm_ccm_vlan;
struct cfm_settings s;
if (!cfg->n_cfm_mpid) {
@@ -3236,14 +3237,22 @@ iface_configure_cfm(struct iface *iface)
s.mpid = *cfg->cfm_mpid;
s.interval = atoi(get_interface_other_config(iface->cfg, "cfm_interval",
"0"));
- s.ccm_vlan = atoi(get_interface_other_config(iface->cfg, "cfm_ccm_vlan",
- "0"));
+ cfm_ccm_vlan = get_interface_other_config(iface->cfg, "cfm_ccm_vlan", "0");
s.ccm_pcp = atoi(get_interface_other_config(iface->cfg, "cfm_ccm_pcp",
"0"));
if (s.interval <= 0) {
s.interval = 1000;
}
+ if (!strcasecmp("random", cfm_ccm_vlan)) {
+ s.ccm_vlan = UINT16_MAX;
+ } else {
+ s.ccm_vlan = atoi(cfm_ccm_vlan);
+ if (s.ccm_vlan == UINT16_MAX) {
+ s.ccm_vlan = 0;
+ }
+ }
+
extended_str = get_interface_other_config(iface->cfg, "cfm_extended",
"false");
s.extended = !strcasecmp("true", extended_str);
diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
index 7739793..3ea6810 100644
--- a/vswitchd/vswitch.xml
+++ b/vswitchd/vswitch.xml
@@ -1768,7 +1768,8 @@
<column name="other_config" key="cfm_ccm_vlan"
type='{"type": "integer", "minInteger": 1, "maxInteger": 4095}'>
When set, the CFM module will apply a VLAN tag to all CCMs it generates
- with the given value.
+ with the given value. May be the string "random" in which case each
+ CCM will be tagged with a different randomly generated VLAN.
</column>
<column name="other_config" key="cfm_ccm_pcp"
--
1.7.9.2
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