@@ -125,7 +125,7 @@ xlate_push_stats_entry(struct xc_entry *entry,
case XC_LEARN: {
enum ofperr error;
error = ofproto_flow_mod_learn(entry->learn.ofm, true,
- entry->learn.limit, NULL);
+ entry->learn.limit, NULL, stats->used);
if (error) {
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
VLOG_WARN_RL(&rl, "xcache LEARN action execution failed.");
@@ -5700,8 +5700,16 @@ xlate_learn_action(struct xlate_ctx *ctx, const struct ofpact_learn *learn)
if (!error) {
bool success = true;
if (ctx->xin->allow_side_effects) {
+ long long int last_used;
+
+ if (ctx->xin->resubmit_stats) {
+ last_used = ctx->xin->resubmit_stats->used;
+ } else {
+ last_used = time_msec();
+ }
error = ofproto_flow_mod_learn(ofm, ctx->xin->xcache != NULL,
- learn->limit, &success);
+ learn->limit, &success,
+ last_used);
} else if (learn->limit) {
if (!ofm->temp_rule
|| ofm->temp_rule->state != RULE_INSERTED) {
@@ -4880,7 +4880,7 @@ packet_xlate(struct ofproto *ofproto_, struct ofproto_packet_out *opo)
if (entry->type == XC_LEARN) {
struct ofproto_flow_mod *ofm = entry->learn.ofm;
- error = ofproto_flow_mod_learn_refresh(ofm);
+ error = ofproto_flow_mod_learn_refresh(ofm, time_msec());
if (error) {
goto error_out;
}
@@ -2027,9 +2027,11 @@ enum ofperr ofproto_flow_mod_init_for_learn(struct ofproto *,
struct ofproto_flow_mod *)
OVS_EXCLUDED(ofproto_mutex);
enum ofperr ofproto_flow_mod_learn(struct ofproto_flow_mod *, bool keep_ref,
- unsigned limit, bool *below_limit)
+ unsigned limit, bool *below_limit,
+ long long int last_used)
OVS_EXCLUDED(ofproto_mutex);
-enum ofperr ofproto_flow_mod_learn_refresh(struct ofproto_flow_mod *ofm);
+enum ofperr ofproto_flow_mod_learn_refresh(struct ofproto_flow_mod *ofm,
+ long long int last_used);
enum ofperr ofproto_flow_mod_learn_start(struct ofproto_flow_mod *ofm)
OVS_REQUIRES(ofproto_mutex);
void ofproto_flow_mod_learn_revert(struct ofproto_flow_mod *ofm)
@@ -5472,7 +5472,8 @@ ofproto_flow_mod_init_for_learn(struct ofproto *ofproto,
}
enum ofperr
-ofproto_flow_mod_learn_refresh(struct ofproto_flow_mod *ofm)
+ofproto_flow_mod_learn_refresh(struct ofproto_flow_mod *ofm,
+ long long int last_used)
{
enum ofperr error = 0;
@@ -5493,9 +5494,37 @@ ofproto_flow_mod_learn_refresh(struct ofproto_flow_mod *ofm)
* this function is executed the rule will be reinstated. */
if (rule->state == RULE_REMOVED) {
struct cls_rule cr;
+ struct oftable *table = &rule->ofproto->tables[rule->table_id];
+ ovs_version_t tables_version = rule->ofproto->tables_version;
+
+ if (!cls_rule_visible_in_version(&rule->cr, tables_version)) {
+ const struct cls_rule *curr_cls_rule;
+
+ /* Only check for matching classifier rules and their modified
+ * time, instead of also checking all rule metadata, with the goal
+ * of suppressing a learn action update that would replace a more
+ * recent rule in the classifier. */
+ curr_cls_rule = classifier_find_rule_exactly(&table->cls,
+ &rule->cr,
+ tables_version);
+ if (curr_cls_rule) {
+ struct rule *curr_rule = rule_from_cls_rule(curr_cls_rule);
+ long long int curr_last_used;
+
+ ovs_mutex_lock(&curr_rule->mutex);
+ curr_last_used = curr_rule->modified;
+ ovs_mutex_unlock(&curr_rule->mutex);
+
+ if (curr_last_used > last_used) {
+ /* In the case of a newer visible rule, don't recreate the
+ * current rule. */
+ return 0;
+ }
+ }
+ }
- cls_rule_clone(&cr, &rule->cr);
ovs_mutex_lock(&rule->mutex);
+ cls_rule_clone(&cr, &rule->cr);
error = ofproto_rule_create(rule->ofproto, &cr, rule->table_id,
rule->flow_cookie,
rule->idle_timeout,
@@ -5506,6 +5535,7 @@ ofproto_flow_mod_learn_refresh(struct ofproto_flow_mod *ofm)
rule->match_tlv_bitmap,
rule->ofpacts_tlv_bitmap,
&ofm->temp_rule);
+ ofm->temp_rule->modified = last_used;
ovs_mutex_unlock(&rule->mutex);
if (!error) {
ofproto_rule_unref(rule); /* Release old reference. */
@@ -5513,7 +5543,7 @@ ofproto_flow_mod_learn_refresh(struct ofproto_flow_mod *ofm)
} else {
/* Refresh the existing rule. */
ovs_mutex_lock(&rule->mutex);
- rule->modified = time_msec();
+ rule->modified = last_used;
ovs_mutex_unlock(&rule->mutex);
}
return error;
@@ -5565,10 +5595,16 @@ ofproto_flow_mod_learn_finish(struct ofproto_flow_mod *ofm,
/* Refresh 'ofm->temp_rule', for which the caller holds a reference, if already
* in the classifier, insert it otherwise. If the rule has already been
- * removed from the classifier, a new rule is created using 'ofm->temp_rule' as
- * a template and the reference to the old 'ofm->temp_rule' is freed. If
- * 'keep_ref' is true, then a reference to the current rule is held, otherwise
- * it is released and 'ofm->temp_rule' is set to NULL.
+ * removed from the classifier and replaced by another rule, the 'last_used'
+ * parameter is used to determine whether the newer rule is replaced or kept.
+ * If 'last_used' is greater than the last modified time of an identical rule
+ * in the classifier, then a new rule is created using 'ofm->temp_rule' as a
+ * template and the reference to the old 'ofm->temp_rule' is freed. If the
+ * rule has been removed but another identical rule doesn't exist in the
+ * classifier, then it will be recreated. If the rule hasn't been removed
+ * from the classifier, then 'last_used' is used to update the rules modified
+ * time. If 'keep_ref' is true, then a reference to the current rule is held,
+ * otherwise it is released and 'ofm->temp_rule' is set to NULL.
*
* If 'limit' != 0, insertion will fail if there are more than 'limit' rules
* in the same table with the same cookie. If insertion succeeds,
@@ -5579,10 +5615,11 @@ ofproto_flow_mod_learn_finish(struct ofproto_flow_mod *ofm,
* during the call. */
enum ofperr
ofproto_flow_mod_learn(struct ofproto_flow_mod *ofm, bool keep_ref,
- unsigned limit, bool *below_limitp)
+ unsigned limit, bool *below_limitp,
+ long long int last_used)
OVS_EXCLUDED(ofproto_mutex)
{
- enum ofperr error = ofproto_flow_mod_learn_refresh(ofm);
+ enum ofperr error = ofproto_flow_mod_learn_refresh(ofm, last_used);
struct rule *rule = ofm->temp_rule;
bool below_limit = true;
@@ -5615,6 +5652,11 @@ ofproto_flow_mod_learn(struct ofproto_flow_mod *ofm, bool keep_ref,
error = ofproto_flow_mod_learn_start(ofm);
if (!error) {
+ /* ofproto_flow_mod_learn_start may have overwritten
+ * modified with current time. */
+ ovs_mutex_lock(&ofm->temp_rule->mutex);
+ ofm->temp_rule->modified = last_used;
+ ovs_mutex_unlock(&ofm->temp_rule->mutex);
error = ofproto_flow_mod_learn_finish(ofm, NULL);
}
} else {
@@ -836,3 +836,63 @@ AT_CHECK([ovs-vsctl add-br br1 -- set b br1 datapath_type=dummy])
OVS_VSWITCHD_STOP
AT_CLEANUP
+
+AT_SETUP([learning action - flapping learn rule])
+OVS_VSWITCHD_START
+add_of_ports br0 1 2 3
+
+AT_CHECK([ovs-appctl time/stop], [0], [ignore])
+AT_CHECK([[ovs-ofctl add-flow br0 'table=0,priority=2,in_port=1,actions=resubmit(,2)']])
+AT_CHECK([[ovs-ofctl add-flow br0 'table=0,priority=2,in_port=2,actions=resubmit(,2)']])
+AT_CHECK([[ovs-ofctl add-flow br0 'table=2,actions=learn(table=0,hard_timeout=3,priority=1,cookie=0x123,NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],output:OXM_OF_IN_PORT[]),output:3']])
+
+packet="eth(src=50:54:00:00:00:06,dst=50:54:00:00:00:07),eth_type(0x0800),ipv4(src=192.168.0.1,dst=192.168.0.2,proto=6,tos=0,ttl=64,frag=no),tcp(src=8,dst=9)"
+
+dnl Run this test a few times in a loop to reduce the likelyhood that it passes by chance.
+for i in 1 2 3; do
+ AT_CHECK([ovs-appctl revalidator/pause], [0])
+ AT_CHECK([ovs-appctl netdev-dummy/receive p2 $packet], [0])
+ AT_CHECK([ovs-appctl time/warp 75], [0], [ignore])
+ AT_CHECK([ovs-appctl netdev-dummy/receive p1 $packet], [0])
+ AT_CHECK([ovs-appctl time/warp 75], [0], [ignore])
+ AT_CHECK([ovs-appctl netdev-dummy/receive p2 $packet], [0])
+ AT_CHECK([ovs-appctl time/warp 75], [0], [ignore])
+ AT_CHECK([ovs-appctl netdev-dummy/receive p1 $packet], [0])
+ AT_CHECK([ovs-appctl time/warp 75], [0], [ignore])
+
+ AT_CHECK([ovs-appctl revalidator/resume], [0])
+ AT_CHECK([ovs-appctl revalidator/wait], [0])
+
+ AT_CHECK([ovs-ofctl --no-stats dump-flows br0 | ofctl_strip | sort | grep 0x123], [0], [dnl
+ cookie=0x123, hard_timeout=3, priority=1,dl_dst=50:54:00:00:00:06 actions=output:1
+ table=2, actions=learn(table=0,hard_timeout=3,priority=1,cookie=0x123,NXM_OF_ETH_DST[[]]=NXM_OF_ETH_SRC[[]],output:OXM_OF_IN_PORT[[]]),output:3
+])
+
+ AT_CHECK([ovs-appctl revalidator/pause], [0])
+ AT_CHECK([ovs-appctl netdev-dummy/receive p1 $packet], [0])
+ AT_CHECK([ovs-appctl time/warp 75], [0], [ignore])
+ AT_CHECK([ovs-appctl netdev-dummy/receive p2 $packet], [0])
+ AT_CHECK([ovs-appctl time/warp 75], [0], [ignore])
+ AT_CHECK([ovs-appctl netdev-dummy/receive p1 $packet], [0])
+ AT_CHECK([ovs-appctl time/warp 75], [0], [ignore])
+ AT_CHECK([ovs-appctl netdev-dummy/receive p2 $packet], [0])
+ AT_CHECK([ovs-appctl time/warp 75], [0], [ignore])
+
+ AT_CHECK([ovs-appctl revalidator/resume], [0])
+ AT_CHECK([ovs-appctl revalidator/wait], [0])
+
+ AT_CHECK([ovs-ofctl --no-stats dump-flows br0 | ofctl_strip | sort | grep 0x123], [0], [dnl
+ cookie=0x123, hard_timeout=3, priority=1,dl_dst=50:54:00:00:00:06 actions=output:2
+ table=2, actions=learn(table=0,hard_timeout=3,priority=1,cookie=0x123,NXM_OF_ETH_DST[[]]=NXM_OF_ETH_SRC[[]],output:OXM_OF_IN_PORT[[]]),output:3
+])
+done
+
+dnl Wait and check for learned rule eviction due to hard timeout.
+AT_CHECK([ovs-appctl time/warp 3200], [0], [ignore])
+
+AT_CHECK([ovs-ofctl --no-stats dump-flows br0 | ofctl_strip | grep 0x123], [0], [dnl
+ table=2, actions=learn(table=0,hard_timeout=3,priority=1,cookie=0x123,NXM_OF_ETH_DST[[]]=NXM_OF_ETH_SRC[[]],output:OXM_OF_IN_PORT[[]]),output:3
+])
+
+OVS_VSWITCHD_STOP
+AT_CLEANUP
When the a revalidator thread is updating statistics for an XC_LEARN xcache entry in xlate_push_stats_entry it uses ofproto_flow_mod_learn. The revalidator will update stats for rules even if they are in a removed state or marked as invisible. However, ofproto_flow_mod_learn will detect if a flow has been removed and re-add it in that case. This can result in an old learn action replacing the new learn action that had replaced it in the first place. This change adds a new last_used parameter to ofproto_flow_mod_learn allowing the caller to provide a timestamp that will be fed into the learned rule's modified time. The provided timestamp should be the time of the last packet activity. If last_used is not set then the current time is used, as is the current behaviour. This change also adds a check when replacing a learned rule to favour the newest rule. Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=2213892 Signed-off-by: Mike Pattrick <mkp@redhat.com> --- v2: Added additional checks if rule is removed v3: v2 patch was corrupted in transit v4: Added check against dpif flow stats v5: Fixed typos, updated commit message Changed timestamps to use datapath timestamp more consistently v6: Added a unit test, changed some variable names and comments, zero is no longer an acceptable value v7: Simplified unit test, updated comments. v8: Removed debug test that was included with v7 by accident. Updated tests and comments per feedback --- ofproto/ofproto-dpif-xlate-cache.c | 2 +- ofproto/ofproto-dpif-xlate.c | 10 ++++- ofproto/ofproto-dpif.c | 2 +- ofproto/ofproto-provider.h | 6 ++- ofproto/ofproto.c | 60 +++++++++++++++++++++++++----- tests/learn.at | 60 ++++++++++++++++++++++++++++++ 6 files changed, 126 insertions(+), 14 deletions(-) -- 2.39.3