/* Copyright (c) 2008 The Board of Trustees of The Leland Stanford
* Junior University
- *
+ *
* We are making the OpenFlow specification and associated documentation
* (Software) available for public use and benefit with the expectation
* that others will use, modify and enhance the Software and contribute
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
- *
+ *
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
- *
+ *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
- *
+ *
* The name and trademarks of copyright holder(s) may NOT be used in
* advertising or publicity pertaining to the Software or any
* derivatives without specific, written prior permission.
*/
+#include <config.h>
#include "rconn.h"
#include <assert.h>
#include <errno.h>
+#include <limits.h>
#include <stdlib.h>
#include <string.h>
-#include "buffer.h"
+#include "ofpbuf.h"
+#include "openflow/openflow.h"
#include "poll-loop.h"
-#include "ofp-print.h"
+#include "sat-math.h"
+#include "timeval.h"
#include "util.h"
#include "vconn.h"
#define THIS_MODULE VLM_rconn
#include "vlog.h"
+#define STATES \
+ STATE(VOID, 1 << 0) \
+ STATE(BACKOFF, 1 << 1) \
+ STATE(CONNECTING, 1 << 2) \
+ STATE(ACTIVE, 1 << 3) \
+ STATE(IDLE, 1 << 4)
+enum state {
+#define STATE(NAME, VALUE) S_##NAME = VALUE,
+ STATES
+#undef STATE
+};
+
+static const char *
+state_name(enum state state)
+{
+ switch (state) {
+#define STATE(NAME, VALUE) case S_##NAME: return #NAME;
+ STATES
+#undef STATE
+ }
+ return "***ERROR***";
+}
+
/* A reliable connection to an OpenFlow switch or controller.
*
* See the large comment in rconn.h for more information. */
struct rconn {
- bool reliable;
- char *name;
+ enum state state;
+ time_t state_entered;
+
struct vconn *vconn;
- bool connected;
- struct queue txq;
- int txq_limit;
- time_t backoff_deadline;
+ char *name;
+ bool reliable;
+
+ struct ofp_queue txq;
+
int backoff;
int max_backoff;
+ time_t backoff_deadline;
+ time_t last_received;
time_t last_connected;
unsigned int packets_sent;
+ /* In S_ACTIVE and S_IDLE, probably_admitted reports whether we believe
+ * that the peer has made a (positive) admission control decision on our
+ * connection. If we have not yet been (probably) admitted, then the
+ * connection does not reset the timer used for deciding whether the switch
+ * should go into fail-open mode.
+ *
+ * last_admitted reports the last time we believe such a positive admission
+ * control decision was made. */
+ bool probably_admitted;
+ time_t last_admitted;
+
+ /* These values are simply for statistics reporting, not used directly by
+ * anything internal to the rconn (or the secchan for that matter). */
+ unsigned int packets_received;
+ unsigned int n_attempted_connections, n_successful_connections;
+ time_t creation_time;
+ unsigned long int total_time_connected;
+
+ /* If we can't connect to the peer, it could be for any number of reasons.
+ * Usually, one would assume it is because the peer is not running or
+ * because the network is partitioned. But it could also be because the
+ * network topology has changed, in which case the upper layer will need to
+ * reassess it (in particular, obtain a new IP address via DHCP and find
+ * the new location of the controller). We set this flag when we suspect
+ * that this could be the case. */
+ bool questionable_connectivity;
+ time_t last_questioned;
+
/* Throughout this file, "probe" is shorthand for "inactivity probe".
* When nothing has been received from the peer for a while, we send out
* an echo request as an inactivity probe packet. We should receive back
* a response. */
int probe_interval; /* Secs of inactivity before sending probe. */
- time_t probe_sent; /* Time at which last probe sent, or 0 if none
- * has been sent since 'last_connected'. */
+
+ /* Messages sent or received are copied to the monitor connections. */
+#define MAX_MONITORS 8
+ struct vconn *monitors[8];
+ size_t n_monitors;
};
-static struct rconn *create_rconn(const char *name, int txq_limit,
- int probe_interval, int max_backoff,
- struct vconn *);
+static unsigned int elapsed_in_this_state(const struct rconn *);
+static unsigned int timeout(const struct rconn *);
+static bool timed_out(const struct rconn *);
+static void state_transition(struct rconn *, enum state);
static int try_send(struct rconn *);
+static int reconnect(struct rconn *);
static void disconnect(struct rconn *, int error);
-static time_t probe_deadline(const struct rconn *);
+static void flush_queue(struct rconn *);
+static void question_connectivity(struct rconn *);
+static void copy_to_monitor(struct rconn *, const struct ofpbuf *);
+static bool is_connected_state(enum state);
+static bool is_admitted_msg(const struct ofpbuf *);
-/* Creates and returns a new rconn that connects (and re-connects as necessary)
- * to the vconn named 'name'.
- *
- * 'txq_limit' is the maximum length of the send queue, in packets.
+/* Creates a new rconn, connects it (reliably) to 'name', and returns it. */
+struct rconn *
+rconn_new(const char *name, int inactivity_probe_interval, int max_backoff)
+{
+ struct rconn *rc = rconn_create(inactivity_probe_interval, max_backoff);
+ rconn_connect(rc, name);
+ return rc;
+}
+
+/* Creates a new rconn, connects it (unreliably) to 'vconn', and returns it. */
+struct rconn *
+rconn_new_from_vconn(const char *name, struct vconn *vconn)
+{
+ struct rconn *rc = rconn_create(60, 0);
+ rconn_connect_unreliably(rc, name, vconn);
+ return rc;
+}
+
+/* Creates and returns a new rconn.
*
* 'probe_interval' is a number of seconds. If the interval passes once
* without an OpenFlow message being received from the peer, the rconn sends
* failure until it reaches 'max_backoff'. If 0 is specified, the default of
* 60 seconds is used. */
struct rconn *
-rconn_new(const char *name, int txq_limit, int probe_interval, int max_backoff)
+rconn_create(int probe_interval, int max_backoff)
{
- return create_rconn(name, txq_limit, probe_interval, max_backoff, NULL);
+ struct rconn *rc = xcalloc(1, sizeof *rc);
+
+ rc->state = S_VOID;
+ rc->state_entered = time_now();
+
+ rc->vconn = NULL;
+ rc->name = xstrdup("void");
+ rc->reliable = false;
+
+ queue_init(&rc->txq);
+
+ rc->backoff = 0;
+ rc->max_backoff = max_backoff ? max_backoff : 60;
+ rc->backoff_deadline = TIME_MIN;
+ rc->last_received = time_now();
+ rc->last_connected = time_now();
+
+ rc->packets_sent = 0;
+
+ rc->probably_admitted = false;
+ rc->last_admitted = time_now();
+
+ rc->packets_received = 0;
+ rc->n_attempted_connections = 0;
+ rc->n_successful_connections = 0;
+ rc->creation_time = time_now();
+ rc->total_time_connected = 0;
+
+ rc->questionable_connectivity = false;
+ rc->last_questioned = time_now();
+
+ rc->probe_interval = probe_interval ? MAX(5, probe_interval) : 0;
+
+ rc->n_monitors = 0;
+
+ return rc;
}
-/* Creates and returns a new rconn that is initially connected to 'vconn' and
- * has the given 'name'. The rconn will not re-connect after the connection
- * drops.
- *
- * 'txq_limit' is the maximum length of the send queue, in packets. */
-struct rconn *
-rconn_new_from_vconn(const char *name, int txq_limit, struct vconn *vconn)
+int
+rconn_connect(struct rconn *rc, const char *name)
+{
+ rconn_disconnect(rc);
+ free(rc->name);
+ rc->name = xstrdup(name);
+ rc->reliable = true;
+ return reconnect(rc);
+}
+
+void
+rconn_connect_unreliably(struct rconn *rc,
+ const char *name, struct vconn *vconn)
{
assert(vconn != NULL);
- return create_rconn(name, txq_limit, 0, 0, vconn);
+ rconn_disconnect(rc);
+ free(rc->name);
+ rc->name = xstrdup(name);
+ rc->reliable = false;
+ rc->vconn = vconn;
+ rc->last_connected = time_now();
+ state_transition(rc, S_ACTIVE);
+}
+
+void
+rconn_disconnect(struct rconn *rc)
+{
+ if (rc->state != S_VOID) {
+ if (rc->vconn) {
+ vconn_close(rc->vconn);
+ rc->vconn = NULL;
+ }
+ free(rc->name);
+ rc->name = xstrdup("void");
+ rc->reliable = false;
+
+ rc->backoff = 0;
+ rc->backoff_deadline = TIME_MIN;
+
+ state_transition(rc, S_VOID);
+ }
}
/* Disconnects 'rc' and frees the underlying storage. */
rconn_destroy(struct rconn *rc)
{
if (rc) {
+ size_t i;
+
free(rc->name);
vconn_close(rc->vconn);
+ flush_queue(rc);
queue_destroy(&rc->txq);
+ for (i = 0; i < rc->n_monitors; i++) {
+ vconn_close(rc->monitors[i]);
+ }
free(rc);
}
}
+static unsigned int
+timeout_VOID(const struct rconn *rc)
+{
+ return UINT_MAX;
+}
+
+static void
+run_VOID(struct rconn *rc)
+{
+ /* Nothing to do. */
+}
+
+static int
+reconnect(struct rconn *rc)
+{
+ int retval;
+
+ VLOG_WARN("%s: connecting...", rc->name);
+ rc->n_attempted_connections++;
+ retval = vconn_open(rc->name, OFP_VERSION, &rc->vconn);
+ if (!retval) {
+ rc->backoff_deadline = time_now() + rc->backoff;
+ state_transition(rc, S_CONNECTING);
+ } else {
+ VLOG_WARN("%s: connection failed (%s)", rc->name, strerror(retval));
+ rc->backoff_deadline = TIME_MAX; /* Prevent resetting backoff. */
+ disconnect(rc, 0);
+ }
+ return retval;
+}
+
+static unsigned int
+timeout_BACKOFF(const struct rconn *rc)
+{
+ return rc->backoff;
+}
+
+static void
+run_BACKOFF(struct rconn *rc)
+{
+ if (timed_out(rc)) {
+ reconnect(rc);
+ }
+}
+
+static unsigned int
+timeout_CONNECTING(const struct rconn *rc)
+{
+ return MAX(1, rc->backoff);
+}
+
+static void
+run_CONNECTING(struct rconn *rc)
+{
+ int retval = vconn_connect(rc->vconn);
+ if (!retval) {
+ VLOG_WARN("%s: connected", rc->name);
+ rc->n_successful_connections++;
+ state_transition(rc, S_ACTIVE);
+ rc->last_connected = rc->state_entered;
+ } else if (retval != EAGAIN) {
+ VLOG_WARN("%s: connection failed (%s)", rc->name, strerror(retval));
+ disconnect(rc, retval);
+ } else if (timed_out(rc)) {
+ VLOG_WARN("%s: connection timed out", rc->name);
+ rc->backoff_deadline = TIME_MAX; /* Prevent resetting backoff. */
+ disconnect(rc, 0);
+ }
+}
+
+static void
+do_tx_work(struct rconn *rc)
+{
+ if (!rc->txq.n) {
+ return;
+ }
+ while (rc->txq.n > 0) {
+ int error = try_send(rc);
+ if (error) {
+ break;
+ }
+ }
+ if (!rc->txq.n) {
+ poll_immediate_wake();
+ }
+}
+
+static unsigned int
+timeout_ACTIVE(const struct rconn *rc)
+{
+ if (rc->probe_interval) {
+ unsigned int base = MAX(rc->last_received, rc->state_entered);
+ unsigned int arg = base + rc->probe_interval - rc->state_entered;
+ return arg;
+ }
+ return UINT_MAX;
+}
+
+static void
+run_ACTIVE(struct rconn *rc)
+{
+ if (timed_out(rc)) {
+ unsigned int base = MAX(rc->last_received, rc->state_entered);
+ rconn_send(rc, make_echo_request(), NULL);
+ VLOG_DBG("%s: idle %u seconds, sending inactivity probe",
+ rc->name, (unsigned int) (time_now() - base));
+ state_transition(rc, S_IDLE);
+ return;
+ }
+
+ do_tx_work(rc);
+}
+
+static unsigned int
+timeout_IDLE(const struct rconn *rc)
+{
+ return rc->probe_interval;
+}
+
+static void
+run_IDLE(struct rconn *rc)
+{
+ if (timed_out(rc)) {
+ question_connectivity(rc);
+ VLOG_ERR("%s: no response to inactivity probe after %u "
+ "seconds, disconnecting",
+ rc->name, elapsed_in_this_state(rc));
+ disconnect(rc, 0);
+ } else {
+ do_tx_work(rc);
+ }
+}
+
/* Performs whatever activities are necessary to maintain 'rc': if 'rc' is
* disconnected, attempts to (re)connect, backing off as necessary; if 'rc' is
* connected, attempts to send packets in the send queue, if any. */
void
rconn_run(struct rconn *rc)
{
- if (!rc->vconn) {
- if (rc->reliable && time(0) >= rc->backoff_deadline) {
- int retval;
-
- retval = vconn_open(rc->name, &rc->vconn);
- if (!retval) {
- rc->backoff_deadline = time(0) + rc->backoff;
- rc->connected = false;
- } else {
- VLOG_WARN("%s: connection failed (%s)",
- rc->name, strerror(retval));
- disconnect(rc, 0);
- }
- }
- } else if (!rc->connected) {
- int error = vconn_connect(rc->vconn);
- if (!error) {
- VLOG_WARN("%s: connected", rc->name);
- if (vconn_is_passive(rc->vconn)) {
- fatal(0, "%s: passive vconn not supported in switch",
- rc->name);
- }
- rc->connected = true;
- } else if (error != EAGAIN) {
- VLOG_WARN("%s: connection failed (%s)", rc->name, strerror(error));
- disconnect(rc, 0);
+ int old_state;
+ do {
+ old_state = rc->state;
+ switch (rc->state) {
+#define STATE(NAME, VALUE) case S_##NAME: run_##NAME(rc); break;
+ STATES
+#undef STATE
+ default:
+ NOT_REACHED();
}
- } else {
- if (rc->probe_interval) {
- time_t now = time(0);
- if (now >= probe_deadline(rc)) {
- if (!rc->probe_sent) {
- queue_push_tail(&rc->txq, make_echo_request());
- rc->probe_sent = now;
- VLOG_DBG("%s: idle %d seconds, sending inactivity probe",
- rc->name, (int) (now - rc->last_connected));
- } else {
- VLOG_ERR("%s: no response to inactivity probe after %d "
- "seconds, disconnecting",
- rc->name, (int) (now - rc->probe_sent));
- disconnect(rc, 0);
- }
- }
- }
- while (rc->txq.n > 0) {
- int error = try_send(rc);
- if (error == EAGAIN) {
- break;
- } else if (error) {
- disconnect(rc, error);
- return;
- }
- }
- }
+ } while (rc->state != old_state);
}
/* Causes the next call to poll_block() to wake up when rconn_run() should be
void
rconn_run_wait(struct rconn *rc)
{
- if (rc->vconn) {
- if (rc->txq.n) {
- vconn_wait(rc->vconn, WAIT_SEND);
- }
- if (rc->probe_interval) {
- poll_timer_wait((probe_deadline(rc) - time(0)) * 1000);
- }
- } else {
- poll_timer_wait((rc->backoff_deadline - time(0)) * 1000);
+ unsigned int timeo = timeout(rc);
+ if (timeo != UINT_MAX) {
+ unsigned int expires = sat_add(rc->state_entered, timeo);
+ unsigned int remaining = sat_sub(expires, time_now());
+ poll_timer_wait(sat_mul(remaining, 1000));
}
-}
-/* Returns the time at which, should nothing be received, we should send out an
- * inactivity probe (if none has yet been sent) or conclude that the connection
- * is dead (if a probe has already been sent). */
-static time_t
-probe_deadline(const struct rconn *rc)
-{
- assert(rc->probe_interval);
- return (rc->probe_interval
- + (rc->probe_sent ? rc->probe_sent : rc->last_connected));
+ if ((rc->state & (S_ACTIVE | S_IDLE)) && rc->txq.n) {
+ vconn_wait(rc->vconn, WAIT_SEND);
+ }
}
/* Attempts to receive a packet from 'rc'. If successful, returns the packet;
* otherwise, returns a null pointer. The caller is responsible for freeing
- * the packet (with buffer_delete()). */
-struct buffer *
+ * the packet (with ofpbuf_delete()). */
+struct ofpbuf *
rconn_recv(struct rconn *rc)
{
- if (rc->vconn && rc->connected) {
- struct buffer *buffer;
+ if (rc->state & (S_ACTIVE | S_IDLE)) {
+ struct ofpbuf *buffer;
int error = vconn_recv(rc->vconn, &buffer);
if (!error) {
- rc->last_connected = time(0);
- rc->probe_sent = 0;
+ copy_to_monitor(rc, buffer);
+ if (is_admitted_msg(buffer)
+ || time_now() - rc->last_connected >= 30) {
+ rc->probably_admitted = true;
+ rc->last_admitted = time_now();
+ }
+ rc->last_received = time_now();
+ rc->packets_received++;
+ if (rc->state == S_IDLE) {
+ state_transition(rc, S_ACTIVE);
+ }
return buffer;
} else if (error != EAGAIN) {
- disconnect(rc, error);
+ disconnect(rc, error);
}
}
return NULL;
/* Causes the next call to poll_block() to wake up when a packet may be ready
* to be received by vconn_recv() on 'rc'. */
void
-rconn_recv_wait(struct rconn *rc)
+rconn_recv_wait(struct rconn *rc)
{
if (rc->vconn) {
vconn_wait(rc->vconn, WAIT_RECV);
}
}
-/* Sends 'b' on 'rc'. Returns 0 if successful, EAGAIN if at least 'txq_limit'
- * packets are already queued, otherwise a positive errno value. */
+/* Sends 'b' on 'rc'. Returns 0 if successful (in which case 'b' is
+ * destroyed), or ENOTCONN if 'rc' is not currently connected (in which case
+ * the caller retains ownership of 'b').
+ *
+ * If 'n_queued' is non-null, then '*n_queued' will be incremented while the
+ * packet is in flight, then decremented when it has been sent (or discarded
+ * due to disconnection). Because 'b' may be sent (or discarded) before this
+ * function returns, the caller may not be able to observe any change in
+ * '*n_queued'.
+ *
+ * There is no rconn_send_wait() function: an rconn has a send queue that it
+ * takes care of sending if you call rconn_run(), which will have the side
+ * effect of waking up poll_block(). */
int
-do_send(struct rconn *rc, struct buffer *b, int txq_limit)
+rconn_send(struct rconn *rc, struct ofpbuf *b, int *n_queued)
{
- if (rc->vconn) {
- if (rc->txq.n < txq_limit) {
- queue_push_tail(&rc->txq, b);
- if (rc->txq.n == 1) {
- try_send(rc);
- }
- return 0;
- } else {
- return EAGAIN;
+ if (rconn_is_connected(rc)) {
+ copy_to_monitor(rc, b);
+ b->private = n_queued;
+ if (n_queued) {
+ ++*n_queued;
}
+ queue_push_tail(&rc->txq, b);
+ if (rc->txq.n == 1) {
+ try_send(rc);
+ }
+ return 0;
} else {
return ENOTCONN;
}
}
-/* Sends 'b' on 'rc'. Returns 0 if successful, EAGAIN if the send queue is
- * full, or ENOTCONN if 'rc' is not currently connected.
+/* Sends 'b' on 'rc'. Increments '*n_queued' while the packet is in flight; it
+ * will be decremented when it has been sent (or discarded due to
+ * disconnection). Returns 0 if successful, EAGAIN if '*n_queued' is already
+ * at least as large as 'queue_limit', or ENOTCONN if 'rc' is not currently
+ * connected. Regardless of return value, 'b' is destroyed.
+ *
+ * Because 'b' may be sent (or discarded) before this function returns, the
+ * caller may not be able to observe any change in '*n_queued'.
*
* There is no rconn_send_wait() function: an rconn has a send queue that it
* takes care of sending if you call rconn_run(), which will have the side
* effect of waking up poll_block(). */
int
-rconn_send(struct rconn *rc, struct buffer *b)
+rconn_send_with_limit(struct rconn *rc, struct ofpbuf *b,
+ int *n_queued, int queue_limit)
{
- return do_send(rc, b, rc->txq_limit);
-}
-
-/* Sends 'b' on 'rc'. Returns 0 if successful, EAGAIN if the send queue is
- * full, otherwise a positive errno value.
- *
- * Compared to rconn_send(), this function relaxes the queue limit, allowing
- * more packets than usual to be queued. */
-int
-rconn_force_send(struct rconn *rc, struct buffer *b)
-{
- return do_send(rc, b, 2 * rc->txq_limit);
-}
-
-/* Returns true if 'rc''s send buffer is full,
- * false if it has room for at least one more packet. */
-bool
-rconn_is_full(const struct rconn *rc)
-{
- return rc->txq.n >= rc->txq_limit;
+ int retval;
+ retval = *n_queued >= queue_limit ? EAGAIN : rconn_send(rc, b, n_queued);
+ if (retval) {
+ ofpbuf_delete(b);
+ }
+ return retval;
}
/* Returns the total number of packets successfully sent on the underlying
* vconn. A packet is not counted as sent while it is still queued in the
* rconn, only when it has been successfuly passed to the vconn. */
unsigned int
-rconn_packets_sent(const struct rconn *rc)
+rconn_packets_sent(const struct rconn *rc)
{
return rc->packets_sent;
}
+/* Adds 'vconn' to 'rc' as a monitoring connection, to which all messages sent
+ * and received on 'rconn' will be copied. 'rc' takes ownership of 'vconn'. */
+void
+rconn_add_monitor(struct rconn *rc, struct vconn *vconn)
+{
+ if (rc->n_monitors < ARRAY_SIZE(rc->monitors)) {
+ VLOG_WARN("new monitor connection from %s", vconn_get_name(vconn));
+ rc->monitors[rc->n_monitors++] = vconn;
+ } else {
+ VLOG_DBG("too many monitor connections, discarding %s",
+ vconn_get_name(vconn));
+ vconn_close(vconn);
+ }
+}
+
/* Returns 'rc''s name (the 'name' argument passed to rconn_new()). */
const char *
-rconn_get_name(const struct rconn *rc)
+rconn_get_name(const struct rconn *rc)
{
return rc->name;
}
/* Returns true if 'rconn' is connected or in the process of reconnecting,
- * false if 'rconn' is disconnected and will not be reconnected. */
+ * false if 'rconn' is disconnected and will not reconnect on its own. */
bool
-rconn_is_alive(const struct rconn *rconn)
+rconn_is_alive(const struct rconn *rconn)
{
- return rconn->reliable || rconn->vconn;
+ return rconn->state != S_VOID;
}
/* Returns true if 'rconn' is connected, false otherwise. */
bool
rconn_is_connected(const struct rconn *rconn)
{
- return rconn->vconn && !vconn_connect(rconn->vconn);
+ return is_connected_state(rconn->state);
}
-/* Returns 0 if 'rconn' is connected, otherwise the number of seconds that it
- * has been disconnected. */
+/* Returns 0 if 'rconn' is connected. Otherwise, if 'rconn' is in a "failure
+ * mode" (that is, it is not connected), returns the number of seconds that it
+ * has been in failure mode, ignoring any times that it connected but the
+ * controller's admission control policy caused it to be quickly
+ * disconnected. */
int
-rconn_disconnected_duration(const struct rconn *rconn)
+rconn_failure_duration(const struct rconn *rconn)
{
- return rconn_is_connected(rconn) ? 0 : time(0) - rconn->last_connected;
+ return rconn_is_connected(rconn) ? 0 : time_now() - rconn->last_admitted;
}
/* Returns the IP address of the peer, or 0 if the peer is not connected over
{
return rconn->vconn ? vconn_get_ip(rconn->vconn) : 0;
}
-\f
-static struct rconn *
-create_rconn(const char *name, int txq_limit, int probe_interval,
- int max_backoff, struct vconn *vconn)
-{
- struct rconn *rc = xmalloc(sizeof *rc);
- assert(txq_limit > 0);
- rc->reliable = vconn == NULL;
- rc->connected = vconn != NULL;
- rc->name = xstrdup(name);
- rc->vconn = vconn;
- queue_init(&rc->txq);
- rc->txq_limit = txq_limit;
- rc->backoff_deadline = time(0);
- rc->backoff = 0;
- rc->max_backoff = max_backoff ? max_backoff : 60;
- rc->last_connected = time(0);
- rc->probe_interval = (probe_interval
- ? MAX(5, probe_interval) : 0);
- rc->probe_sent = 0;
- rc->packets_sent = 0;
- return rc;
+
+/* If 'rconn' can't connect to the peer, it could be for any number of reasons.
+ * Usually, one would assume it is because the peer is not running or because
+ * the network is partitioned. But it could also be because the network
+ * topology has changed, in which case the upper layer will need to reassess it
+ * (in particular, obtain a new IP address via DHCP and find the new location
+ * of the controller). When this appears that this might be the case, this
+ * function returns true. It also clears the questionability flag and prevents
+ * it from being set again for some time. */
+bool
+rconn_is_connectivity_questionable(struct rconn *rconn)
+{
+ bool questionable = rconn->questionable_connectivity;
+ rconn->questionable_connectivity = false;
+ return questionable;
+}
+
+/* Returns the total number of packets successfully received by the underlying
+ * vconn. */
+unsigned int
+rconn_packets_received(const struct rconn *rc)
+{
+ return rc->packets_received;
}
+/* Returns a string representing the internal state of 'rc'. The caller must
+ * not modify or free the string. */
+const char *
+rconn_get_state(const struct rconn *rc)
+{
+ return state_name(rc->state);
+}
+
+/* Returns the number of connection attempts made by 'rc', including any
+ * ongoing attempt that has not yet succeeded or failed. */
+unsigned int
+rconn_get_attempted_connections(const struct rconn *rc)
+{
+ return rc->n_attempted_connections;
+}
+
+/* Returns the number of successful connection attempts made by 'rc'. */
+unsigned int
+rconn_get_successful_connections(const struct rconn *rc)
+{
+ return rc->n_successful_connections;
+}
+
+/* Returns the time at which the last successful connection was made by
+ * 'rc'. */
+time_t
+rconn_get_last_connection(const struct rconn *rc)
+{
+ return rc->last_connected;
+}
+
+/* Returns the time at which 'rc' was created. */
+time_t
+rconn_get_creation_time(const struct rconn *rc)
+{
+ return rc->creation_time;
+}
+
+/* Returns the approximate number of seconds that 'rc' has been connected. */
+unsigned long int
+rconn_get_total_time_connected(const struct rconn *rc)
+{
+ return (rc->total_time_connected
+ + (rconn_is_connected(rc) ? elapsed_in_this_state(rc) : 0));
+}
+
+/* Returns the current amount of backoff, in seconds. This is the amount of
+ * time after which the rconn will transition from BACKOFF to CONNECTING. */
+int
+rconn_get_backoff(const struct rconn *rc)
+{
+ return rc->backoff;
+}
+
+/* Returns the number of seconds spent in this state so far. */
+unsigned int
+rconn_get_state_elapsed(const struct rconn *rc)
+{
+ return elapsed_in_this_state(rc);
+}
+\f
/* Tries to send a packet from 'rc''s send buffer. Returns 0 if successful,
* otherwise a positive errno value. */
static int
try_send(struct rconn *rc)
{
int retval = 0;
- struct buffer *next = rc->txq.head->next;
+ struct ofpbuf *next = rc->txq.head->next;
+ int *n_queued = rc->txq.head->private;
retval = vconn_send(rc->vconn, rc->txq.head);
if (retval) {
+ if (retval != EAGAIN) {
+ disconnect(rc, retval);
+ }
return retval;
}
rc->packets_sent++;
+ if (n_queued) {
+ --*n_queued;
+ }
queue_advance_head(&rc->txq, next);
return 0;
}
* nonzero, then it should be EOF to indicate the connection was closed by the
* peer in a normal fashion or a positive errno value. */
static void
-disconnect(struct rconn *rc, int error)
+disconnect(struct rconn *rc, int error)
{
- time_t now = time(0);
-
- if (rc->vconn) {
- if (error > 0) {
- VLOG_WARN("%s: connection dropped (%s)",
- rc->name, strerror(error));
- } else if (error == EOF) {
- if (rc->reliable) {
- VLOG_WARN("%s: connection closed", rc->name);
+ if (rc->reliable) {
+ time_t now = time_now();
+
+ if (rc->state & (S_CONNECTING | S_ACTIVE | S_IDLE)) {
+ if (error > 0) {
+ VLOG_WARN("%s: connection dropped (%s)",
+ rc->name, strerror(error));
+ } else if (error == EOF) {
+ if (rc->reliable) {
+ VLOG_WARN("%s: connection closed by peer", rc->name);
+ }
+ } else {
+ VLOG_WARN("%s: connection dropped", rc->name);
}
+ vconn_close(rc->vconn);
+ rc->vconn = NULL;
+ flush_queue(rc);
+ }
+
+ if (now >= rc->backoff_deadline) {
+ rc->backoff = 1;
} else {
- VLOG_WARN("%s: connection dropped", rc->name);
+ rc->backoff = MIN(rc->max_backoff, MAX(1, 2 * rc->backoff));
+ VLOG_WARN("%s: waiting %d seconds before reconnect\n",
+ rc->name, rc->backoff);
}
- vconn_close(rc->vconn);
- rc->vconn = NULL;
- queue_clear(&rc->txq);
+ rc->backoff_deadline = now + rc->backoff;
+ state_transition(rc, S_BACKOFF);
+ if (now - rc->last_connected > 60) {
+ question_connectivity(rc);
+ }
+ } else {
+ rconn_disconnect(rc);
}
+}
- if (now >= rc->backoff_deadline) {
- rc->backoff = 1;
- } else {
- rc->backoff = MIN(rc->max_backoff, MAX(1, 2 * rc->backoff));
- VLOG_WARN("%s: waiting %d seconds before reconnect\n",
- rc->name, rc->backoff);
+/* Drops all the packets from 'rc''s send queue and decrements their queue
+ * counts. */
+static void
+flush_queue(struct rconn *rc)
+{
+ if (!rc->txq.n) {
+ return;
+ }
+ while (rc->txq.n > 0) {
+ struct ofpbuf *b = queue_pop_head(&rc->txq);
+ int *n_queued = b->private;
+ if (n_queued) {
+ --*n_queued;
+ }
+ ofpbuf_delete(b);
+ }
+ poll_immediate_wake();
+}
+
+static unsigned int
+elapsed_in_this_state(const struct rconn *rc)
+{
+ return time_now() - rc->state_entered;
+}
+
+static unsigned int
+timeout(const struct rconn *rc)
+{
+ switch (rc->state) {
+#define STATE(NAME, VALUE) case S_##NAME: return timeout_##NAME(rc);
+ STATES
+#undef STATE
+ default:
+ NOT_REACHED();
+ }
+}
+
+static bool
+timed_out(const struct rconn *rc)
+{
+ return time_now() >= sat_add(rc->state_entered, timeout(rc));
+}
+
+static void
+state_transition(struct rconn *rc, enum state state)
+{
+ if (is_connected_state(state) && !is_connected_state(rc->state)) {
+ rc->probably_admitted = false;
+ }
+ if (rconn_is_connected(rc)) {
+ rc->total_time_connected += elapsed_in_this_state(rc);
+ }
+ VLOG_DBG("%s: entering %s", rc->name, state_name(state));
+ rc->state = state;
+ rc->state_entered = time_now();
+}
+
+static void
+question_connectivity(struct rconn *rc)
+{
+ time_t now = time_now();
+ if (now - rc->last_questioned > 60) {
+ rc->questionable_connectivity = true;
+ rc->last_questioned = now;
}
- rc->backoff_deadline = now + rc->backoff;
- rc->probe_sent = 0;
+}
+
+static void
+copy_to_monitor(struct rconn *rc, const struct ofpbuf *b)
+{
+ struct ofpbuf *clone = NULL;
+ int retval;
+ size_t i;
+
+ for (i = 0; i < rc->n_monitors; ) {
+ struct vconn *vconn = rc->monitors[i];
+
+ if (!clone) {
+ clone = ofpbuf_clone(b);
+ }
+ retval = vconn_send(vconn, clone);
+ if (!retval) {
+ clone = NULL;
+ } else if (retval != EAGAIN) {
+ VLOG_DBG("%s: closing monitor connection to %s: %s",
+ rconn_get_name(rc), vconn_get_name(vconn),
+ strerror(retval));
+ rc->monitors[i] = rc->monitors[--rc->n_monitors];
+ continue;
+ }
+ i++;
+ }
+ ofpbuf_delete(clone);
+}
+
+static bool
+is_connected_state(enum state state)
+{
+ return (state & (S_ACTIVE | S_IDLE)) != 0;
+}
+
+static bool
+is_admitted_msg(const struct ofpbuf *b)
+{
+ struct ofp_header *oh = b->data;
+ uint8_t type = oh->type;
+ return !(type < 32
+ && (1u << type) & ((1u << OFPT_HELLO) |
+ (1u << OFPT_ERROR) |
+ (1u << OFPT_ECHO_REQUEST) |
+ (1u << OFPT_ECHO_REPLY) |
+ (1u << OFPT_VENDOR) |
+ (1u << OFPT_FEATURES_REQUEST) |
+ (1u << OFPT_FEATURES_REPLY) |
+ (1u << OFPT_GET_CONFIG_REQUEST) |
+ (1u << OFPT_GET_CONFIG_REPLY) |
+ (1u << OFPT_SET_CONFIG)));
}