/*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include "flow.h"
#include "mac-learning.h"
#include "odp-util.h"
+#include "ofp-util.h"
+#include "ofpbuf.h"
#include "ofproto.h"
+#include "pktbuf.h"
+#include "poll-loop.h"
#include "rconn.h"
#include "status.h"
#include "timeval.h"
-
-#define THIS_MODULE VLM_fail_open
+#include "vconn.h"
#include "vlog.h"
+VLOG_DEFINE_THIS_MODULE(fail_open);
+
+/*
+ * 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 cases when 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;
+ struct rconn **controllers;
+ size_t n_controllers;
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. */
+static void fail_open_recover(struct fail_open *);
+
+/* Returns the number of seconds of disconnection after which fail-open mode
+ * should activate. */
+static int
+trigger_duration(const struct fail_open *fo)
+{
+ if (!fo->n_controllers) {
+ /* Shouldn't ever arrive here, but if we do, never fail open. */
+ return INT_MAX;
+ } else {
+ /* Otherwise, every controller must have a chance to send an
+ * inactivity probe and reconnect before we fail open, so take the
+ * maximum probe interval and multiply by 3:
+ *
+ * - The first interval is the idle time before sending an inactivity
+ * probe.
+ *
+ * - The second interval is the time allowed for a response to the
+ * inactivity probe.
+ *
+ * - The third interval is the time allowed to reconnect after no
+ * response is received.
+ */
+ int max_probe_interval;
+ size_t i;
+
+ max_probe_interval = 0;
+ for (i = 0; i < fo->n_controllers; i++) {
+ int probe_interval = rconn_get_probe_interval(fo->controllers[i]);
+ max_probe_interval = MAX(max_probe_interval, probe_interval);
+ }
+ return max_probe_interval * 3;
+ }
+}
+
+/* Returns the number of seconds for which all controllers have been
+ * disconnected. */
+static int
+failure_duration(const struct fail_open *fo)
+{
+ int min_failure_duration;
+ size_t i;
+
+ if (!fo->n_controllers) {
+ return 0;
+ }
+
+ min_failure_duration = INT_MAX;
+ for (i = 0; i < fo->n_controllers; i++) {
+ int failure_duration = rconn_failure_duration(fo->controllers[i]);
+ min_failure_duration = MIN(min_failure_duration, failure_duration);
+ }
+ return min_failure_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;
+}
+
+/* Returns true if at least one controller is connected (regardless of whether
+ * those controllers are believed to have authenticated and accepted this
+ * switch), false if none of them are connected. */
+static bool
+any_controller_is_connected(const struct fail_open *fo)
+{
+ size_t i;
+
+ for (i = 0; i < fo->n_controllers; i++) {
+ if (rconn_is_connected(fo->controllers[i])) {
+ return true;
+ }
+ }
+ return false;
+}
+
+/* Returns true if at least one controller is believed to have authenticated
+ * and accepted this switch, false otherwise. */
+static bool
+any_controller_is_admitted(const struct fail_open *fo)
+{
+ size_t i;
+
+ for (i = 0; i < fo->n_controllers; i++) {
+ if (rconn_is_admitted(fo->controllers[i])) {
+ return true;
+ }
+ }
+ return false;
+}
+
+static void
+send_bogus_packet_in(struct fail_open *fo, struct rconn *rconn)
+{
+ uint8_t mac[ETH_ADDR_LEN];
+ struct ofpbuf *opi;
+ struct ofpbuf b;
+
+ /* Compose ofp_packet_in. */
+ ofpbuf_init(&b, 128);
+ eth_addr_nicira_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(rconn, opi, fo->bogus_packet_counter, 1);
+}
+
+static void
+send_bogus_packet_ins(struct fail_open *fo)
+{
+ size_t i;
+
+ for (i = 0; i < fo->n_controllers; i++) {
+ if (rconn_is_connected(fo->controllers[i])) {
+ send_bogus_packet_in(fo, fo->controllers[i]);
+ }
+ }
+}
+
+/* Enter fail-open mode if we should be in it. */
void
fail_open_run(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;
-
- VLOG_WARN("No longer in fail-open mode");
- fo->last_disconn_secs = 0;
+ int disconn_secs = failure_duration(fo);
- memset(&flow, 0, sizeof flow);
- ofproto_delete_flow(fo->ofproto, &flow, OFPFW_ALL, 70000);
- } else {
+ /* Enter fail-open mode if 'fo' is not in it but should be. */
+ if (disconn_secs >= trigger_duration(fo)) {
+ 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;
+ }
+ }
+
+ /* Schedule a bogus packet-in if we're connected and in fail-open. */
+ if (fail_open_is_active(fo)) {
+ if (any_controller_is_connected(fo)) {
+ bool expired = time_msec() >= fo->next_bogus_packet_in;
+ if (expired) {
+ send_bogus_packet_ins(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;
}
- } 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;
}
+
}
+/* 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 (any_controller_is_admitted(fo)) {
+ fail_open_recover(fo);
+ }
+}
+
+static void
+fail_open_recover(struct fail_open *fo)
+{
+ if (fail_open_is_active(fo)) {
+ struct flow 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, OVSFW_ALL, FAIL_OPEN_PRIORITY);
+ }
+}
+
+void
+fail_open_wait(struct fail_open *fo)
+{
+ if (fo->next_bogus_packet_in != LLONG_MAX) {
+ poll_timer_wait_until(fo->next_bogus_packet_in);
+ }
}
void
fail_open_flushed(struct fail_open *fo)
{
- int disconn_secs = rconn_failure_duration(fo->controller);
- bool open = disconn_secs >= fo->trigger_duration;
+ int disconn_secs = failure_duration(fo);
+ bool open = disconn_secs >= trigger_duration(fo);
if (open) {
union ofp_action action;
- flow_t flow;
+ struct flow flow;
/* Set up a flow that matches every packet and directs them to
* OFPP_NORMAL. */
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, OVSFW_ALL, FAIL_OPEN_PRIORITY,
&action, 1, 0);
}
}
fail_open_status_cb(struct status_reply *sr, void *fo_)
{
struct fail_open *fo = fo_;
- int cur_duration = rconn_failure_duration(fo->controller);
+ int cur_duration = failure_duration(fo);
+ int trigger = trigger_duration(fo);
- status_reply_put(sr, "trigger-duration=%d", fo->trigger_duration);
+ status_reply_put(sr, "trigger-duration=%d", trigger);
status_reply_put(sr, "current-duration=%d", cur_duration);
status_reply_put(sr, "triggered=%s",
- cur_duration >= fo->trigger_duration ? "true" : "false");
+ cur_duration >= trigger ? "true" : "false");
}
+/* Creates and returns a new struct fail_open for 'ofproto', registering switch
+ * status with 'switch_status'.
+ *
+ * The caller should register its set of controllers with
+ * fail_open_set_controllers(). (There should be at least one controller,
+ * otherwise there isn't any point in having the struct fail_open around.) */
struct fail_open *
-fail_open_create(struct ofproto *ofproto,
- int trigger_duration, struct switch_status *switch_status,
- struct rconn *controller)
+fail_open_create(struct ofproto *ofproto, struct switch_status *switch_status)
{
struct fail_open *fo = xmalloc(sizeof *fo);
fo->ofproto = ofproto;
- fo->controller = controller;
- fo->trigger_duration = trigger_duration;
+ fo->controllers = NULL;
+ fo->n_controllers = 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;
}
+/* Registers the 'n' rconns in 'rconns' as connections to the controller for
+ * 'fo'. The caller must ensure that all of the rconns remain valid until 'fo'
+ * is destroyed or a new set is registered in a subsequent call.
+ *
+ * Takes ownership of the 'rconns' array, but not of the rconns that it points
+ * to (of which the caller retains ownership). */
void
-fail_open_set_trigger_duration(struct fail_open *fo, int trigger_duration)
+fail_open_set_controllers(struct fail_open *fo,
+ struct rconn **rconns, size_t n)
{
- fo->trigger_duration = trigger_duration;
+ free(fo->controllers);
+ fo->controllers = rconns;
+ fo->n_controllers = n;
}
+/* Destroys 'fo'. */
void
fail_open_destroy(struct fail_open *fo)
{
if (fo) {
- /* We don't own fo->controller. */
+ fail_open_recover(fo);
+ free(fo->controllers);
+ /* We don't own the rconns behind fo->controllers. */
switch_status_unregister(fo->ss_cat);
+ rconn_packet_counter_destroy(fo->bogus_packet_counter);
free(fo);
}
}
git://git.onelab.eu / sliver-openvswitch.git / blobdiff