#include "flow.h"
#include "mac-learning.h"
#include "odp-util.h"
+#include "ofpbuf.h"
#include "ofproto.h"
+#include "pktbuf.h"
+#include "poll-loop.h"
#include "rconn.h"
#include "status.h"
#include "timeval.h"
+#include "vconn.h"
#define THIS_MODULE VLM_fail_open
#include "vlog.h"
+/*
+ * Fail-open mode.
+ *
+ * In fail-open mode, the switch detects when the controller cannot be
+ * contacted or when the controller is dropping switch connections because the
+ * switch does not pass its admission control policy. In those situations the
+ * switch sets up flows itself using the "normal" action.
+ *
+ * There is a little subtlety to implementation, to properly handle the case
+ * where the controller allows switch connections but drops them a few seconds
+ * later for admission control reasons. Because of this case, we don't want to
+ * just stop setting up flows when we connect to the controller: if we did,
+ * then new flow setup and existing flows would stop during the duration of
+ * connection to the controller, and thus the whole network would go down for
+ * that period of time.
+ *
+ * So, instead, we add some special caseswhen we are connected to a controller,
+ * but not yet sure that it has admitted us:
+ *
+ * - We set up flows immediately ourselves, but simultaneously send out an
+ * OFPT_PACKET_IN to the controller. We put a special bogus buffer-id in
+ * these OFPT_PACKET_IN messages so that duplicate packets don't get sent
+ * out to the network when the controller replies.
+ *
+ * - We also send out OFPT_PACKET_IN messages for totally bogus packets
+ * every so often, in case no real new flows are arriving in the network.
+ *
+ * - We don't flush the flow table at the time we connect, because this
+ * could cause network stuttering in a switch with lots of flows or very
+ * high-bandwidth flows by suddenly throwing lots of packets down to
+ * userspace.
+ */
+
struct fail_open {
struct ofproto *ofproto;
struct rconn *controller;
int trigger_duration;
int last_disconn_secs;
struct status_category *ss_cat;
+ long long int next_bogus_packet_in;
+ struct rconn_packet_counter *bogus_packet_counter;
};
-/* Causes the switch to enter or leave fail-open mode, if appropriate. */
-void
-fail_open_run(struct fail_open *fo)
+/* Returns true if 'fo' should be in fail-open mode, otherwise false. */
+static inline bool
+should_fail_open(const struct fail_open *fo)
{
- int disconn_secs = rconn_failure_duration(fo->controller);
- bool open = disconn_secs >= fo->trigger_duration;
- if (open != (fo->last_disconn_secs != 0)) {
- if (!open) {
- flow_t flow;
+ return rconn_failure_duration(fo->controller) >= fo->trigger_duration;
+}
+
+/* Returns true if 'fo' is currently in fail-open mode, otherwise false. */
+bool
+fail_open_is_active(const struct fail_open *fo)
+{
+ return fo->last_disconn_secs != 0;
+}
- VLOG_WARN("No longer in fail-open mode");
- fo->last_disconn_secs = 0;
+static void
+send_bogus_packet_in(struct fail_open *fo)
+{
+ uint8_t mac[ETH_ADDR_LEN];
+ struct ofpbuf *opi;
+ struct ofpbuf b;
- memset(&flow, 0, sizeof flow);
- ofproto_delete_flow(fo->ofproto, &flow, OFPFW_ALL, 70000);
- } else {
+ /* Compose ofp_packet_in. */
+ ofpbuf_init(&b, 128);
+ eth_addr_random(mac);
+ compose_benign_packet(&b, "Open vSwitch Controller Probe", 0xa033, mac);
+ opi = make_packet_in(pktbuf_get_null(), OFPP_LOCAL, OFPR_NO_MATCH, &b, 64);
+ ofpbuf_uninit(&b);
+
+ /* Send. */
+ rconn_send_with_limit(fo->controller, opi, fo->bogus_packet_counter, 1);
+}
+
+/* Enter fail-open mode if we should be in it. Handle reconnecting to a
+ * controller from fail-open mode. */
+void
+fail_open_run(struct fail_open *fo)
+{
+ /* Enter fail-open mode if 'fo' is not in it but should be. */
+ if (should_fail_open(fo)) {
+ int disconn_secs = rconn_failure_duration(fo->controller);
+ if (!fail_open_is_active(fo)) {
VLOG_WARN("Could not connect to controller (or switch failed "
"controller's post-connection admission control "
"policy) for %d seconds, failing open", disconn_secs);
* fail-open rule from fail_open_flushed() when
* ofproto_flush_flows() calls back to us. */
ofproto_flush_flows(fo->ofproto);
+ } else if (disconn_secs > fo->last_disconn_secs + 60) {
+ VLOG_INFO("Still in fail-open mode after %d seconds disconnected "
+ "from controller", disconn_secs);
+ fo->last_disconn_secs = disconn_secs;
}
- } else if (open && disconn_secs > fo->last_disconn_secs + 60) {
- VLOG_INFO("Still in fail-open mode after %d seconds disconnected "
- "from controller", disconn_secs);
- fo->last_disconn_secs = disconn_secs;
}
+
+ /* Schedule a bogus packet-in if we're connected and in fail-open. */
+ if (fail_open_is_active(fo)) {
+ if (rconn_is_connected(fo->controller)) {
+ bool expired = time_msec() >= fo->next_bogus_packet_in;
+ if (expired) {
+ send_bogus_packet_in(fo);
+ }
+ if (expired || fo->next_bogus_packet_in == LLONG_MAX) {
+ fo->next_bogus_packet_in = time_msec() + 2000;
+ }
+ } else {
+ fo->next_bogus_packet_in = LLONG_MAX;
+ }
+ }
+
}
+/* If 'fo' is currently in fail-open mode and its rconn has connected to the
+ * controller, exits fail open mode. */
void
-fail_open_wait(struct fail_open *fo UNUSED)
+fail_open_maybe_recover(struct fail_open *fo)
{
- /* Nothing to do. */
+ if (fail_open_is_active(fo) && rconn_is_admitted(fo->controller)) {
+ flow_t flow;
+
+ VLOG_WARN("No longer in fail-open mode");
+ fo->last_disconn_secs = 0;
+ fo->next_bogus_packet_in = LLONG_MAX;
+
+ memset(&flow, 0, sizeof flow);
+ ofproto_delete_flow(fo->ofproto, &flow, OFPFW_ALL, FAIL_OPEN_PRIORITY);
+ }
+}
+
+void
+fail_open_wait(struct fail_open *fo)
+{
+ if (fo->next_bogus_packet_in != LLONG_MAX) {
+ poll_timer_wait(fo->next_bogus_packet_in - time_msec());
+ }
}
void
action.output.len = htons(sizeof action);
action.output.port = htons(OFPP_NORMAL);
memset(&flow, 0, sizeof flow);
- ofproto_add_flow(fo->ofproto, &flow, OFPFW_ALL, 70000,
+ ofproto_add_flow(fo->ofproto, &flow, OFPFW_ALL, FAIL_OPEN_PRIORITY,
&action, 1, 0);
}
}
fo->last_disconn_secs = 0;
fo->ss_cat = switch_status_register(switch_status, "fail-open",
fail_open_status_cb, fo);
+ fo->next_bogus_packet_in = LLONG_MAX;
+ fo->bogus_packet_counter = rconn_packet_counter_create();
return fo;
}
if (fo) {
/* We don't own fo->controller. */
switch_status_unregister(fo->ss_cat);
+ rconn_packet_counter_destroy(fo->bogus_packet_counter);
free(fo);
}
}
git://git.onelab.eu / sliver-openvswitch.git / blobdiff