2 * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
27 #include "openflow/openflow.h"
28 #include "poll-loop.h"
35 VLOG_DEFINE_THIS_MODULE(rconn);
37 COVERAGE_DEFINE(rconn_discarded);
38 COVERAGE_DEFINE(rconn_overflow);
39 COVERAGE_DEFINE(rconn_queued);
40 COVERAGE_DEFINE(rconn_sent);
44 STATE(BACKOFF, 1 << 1) \
45 STATE(CONNECTING, 1 << 2) \
46 STATE(ACTIVE, 1 << 3) \
49 #define STATE(NAME, VALUE) S_##NAME = VALUE,
55 state_name(enum state state)
58 #define STATE(NAME, VALUE) case S_##NAME: return #NAME;
65 /* A reliable connection to an OpenFlow switch or controller.
67 * See the large comment in rconn.h for more information. */
73 char *name; /* Human-readable descriptive name. */
74 char *target; /* vconn name, passed to vconn_open(). */
77 struct list txq; /* Contains "struct ofpbuf"s. */
81 time_t backoff_deadline;
83 time_t last_connected;
84 time_t last_disconnected;
85 unsigned int packets_sent;
89 /* In S_ACTIVE and S_IDLE, probably_admitted reports whether we believe
90 * that the peer has made a (positive) admission control decision on our
91 * connection. If we have not yet been (probably) admitted, then the
92 * connection does not reset the timer used for deciding whether the switch
93 * should go into fail-open mode.
95 * last_admitted reports the last time we believe such a positive admission
96 * control decision was made. */
97 bool probably_admitted;
100 /* These values are simply for statistics reporting, not used directly by
101 * anything internal to the rconn (or ofproto for that matter). */
102 unsigned int packets_received;
103 unsigned int n_attempted_connections, n_successful_connections;
104 time_t creation_time;
105 unsigned long int total_time_connected;
107 /* Throughout this file, "probe" is shorthand for "inactivity probe".
108 * When nothing has been received from the peer for a while, we send out
109 * an echo request as an inactivity probe packet. We should receive back
111 int probe_interval; /* Secs of inactivity before sending probe. */
113 /* When we create a vconn we obtain these values, to save them past the end
114 * of the vconn's lifetime. Otherwise, in-band control will only allow
115 * traffic when a vconn is actually open, but it is nice to allow ARP to
116 * complete even between connection attempts, and it is also polite to
117 * allow traffic from other switches to go through to the controller
118 * whether or not we are connected.
120 * We don't cache the local port, because that changes from one connection
121 * attempt to the next. */
122 uint32_t local_ip, remote_ip;
123 uint16_t remote_port;
125 /* Messages sent or received are copied to the monitor connections. */
126 #define MAX_MONITORS 8
127 struct vconn *monitors[8];
131 static unsigned int elapsed_in_this_state(const struct rconn *);
132 static unsigned int timeout(const struct rconn *);
133 static bool timed_out(const struct rconn *);
134 static void state_transition(struct rconn *, enum state);
135 static void rconn_set_target__(struct rconn *,
136 const char *target, const char *name);
137 static int try_send(struct rconn *);
138 static void reconnect(struct rconn *);
139 static void report_error(struct rconn *, int error);
140 static void disconnect(struct rconn *, int error);
141 static void flush_queue(struct rconn *);
142 static void copy_to_monitor(struct rconn *, const struct ofpbuf *);
143 static bool is_connected_state(enum state);
144 static bool is_admitted_msg(const struct ofpbuf *);
145 static bool rconn_logging_connection_attempts__(const struct rconn *);
147 /* Creates and returns a new rconn.
149 * 'probe_interval' is a number of seconds. If the interval passes once
150 * without an OpenFlow message being received from the peer, the rconn sends
151 * out an "echo request" message. If the interval passes again without a
152 * message being received, the rconn disconnects and re-connects to the peer.
153 * Setting 'probe_interval' to 0 disables this behavior.
155 * 'max_backoff' is the maximum number of seconds between attempts to connect
156 * to the peer. The actual interval starts at 1 second and doubles on each
157 * failure until it reaches 'max_backoff'. If 0 is specified, the default of
160 * The new rconn is initially unconnected. Use rconn_connect() or
161 * rconn_connect_unreliably() to connect it. */
163 rconn_create(int probe_interval, int max_backoff)
165 struct rconn *rc = xzalloc(sizeof *rc);
168 rc->state_entered = time_now();
171 rc->name = xstrdup("void");
172 rc->target = xstrdup("void");
173 rc->reliable = false;
178 rc->max_backoff = max_backoff ? max_backoff : 8;
179 rc->backoff_deadline = TIME_MIN;
180 rc->last_received = time_now();
181 rc->last_connected = TIME_MIN;
182 rc->last_disconnected = TIME_MIN;
185 rc->packets_sent = 0;
187 rc->probably_admitted = false;
188 rc->last_admitted = time_now();
190 rc->packets_received = 0;
191 rc->n_attempted_connections = 0;
192 rc->n_successful_connections = 0;
193 rc->creation_time = time_now();
194 rc->total_time_connected = 0;
196 rconn_set_probe_interval(rc, probe_interval);
204 rconn_set_max_backoff(struct rconn *rc, int max_backoff)
206 rc->max_backoff = MAX(1, max_backoff);
207 if (rc->state == S_BACKOFF && rc->backoff > max_backoff) {
208 rc->backoff = max_backoff;
209 if (rc->backoff_deadline > time_now() + max_backoff) {
210 rc->backoff_deadline = time_now() + max_backoff;
216 rconn_get_max_backoff(const struct rconn *rc)
218 return rc->max_backoff;
222 rconn_set_probe_interval(struct rconn *rc, int probe_interval)
224 rc->probe_interval = probe_interval ? MAX(5, probe_interval) : 0;
228 rconn_get_probe_interval(const struct rconn *rc)
230 return rc->probe_interval;
233 /* Drops any existing connection on 'rc', then sets up 'rc' to connect to
234 * 'target' and reconnect as needed. 'target' should be a remote OpenFlow
235 * target in a form acceptable to vconn_open().
237 * If 'name' is nonnull, then it is used in log messages in place of 'target'.
238 * It should presumably give more information to a human reader than 'target',
239 * but it need not be acceptable to vconn_open(). */
241 rconn_connect(struct rconn *rc, const char *target, const char *name)
243 rconn_disconnect(rc);
244 rconn_set_target__(rc, target, name);
249 /* Drops any existing connection on 'rc', then configures 'rc' to use
250 * 'vconn'. If the connection on 'vconn' drops, 'rc' will not reconnect on it
253 * By default, the target obtained from vconn_get_name(vconn) is used in log
254 * messages. If 'name' is nonnull, then it is used instead. It should
255 * presumably give more information to a human reader than the target, but it
256 * need not be acceptable to vconn_open(). */
258 rconn_connect_unreliably(struct rconn *rc,
259 struct vconn *vconn, const char *name)
261 assert(vconn != NULL);
262 rconn_disconnect(rc);
263 rconn_set_target__(rc, vconn_get_name(vconn), name);
264 rc->reliable = false;
266 rc->last_connected = time_now();
267 state_transition(rc, S_ACTIVE);
270 /* If 'rc' is connected, forces it to drop the connection and reconnect. */
272 rconn_reconnect(struct rconn *rc)
274 if (rc->state & (S_ACTIVE | S_IDLE)) {
275 VLOG_INFO("%s: disconnecting", rc->name);
281 rconn_disconnect(struct rconn *rc)
283 if (rc->state != S_VOID) {
285 vconn_close(rc->vconn);
288 rconn_set_target__(rc, "void", NULL);
289 rc->reliable = false;
292 rc->backoff_deadline = TIME_MIN;
294 state_transition(rc, S_VOID);
298 /* Disconnects 'rc' and frees the underlying storage. */
300 rconn_destroy(struct rconn *rc)
307 vconn_close(rc->vconn);
309 ofpbuf_list_delete(&rc->txq);
310 for (i = 0; i < rc->n_monitors; i++) {
311 vconn_close(rc->monitors[i]);
318 timeout_VOID(const struct rconn *rc OVS_UNUSED)
324 run_VOID(struct rconn *rc OVS_UNUSED)
330 reconnect(struct rconn *rc)
334 if (rconn_logging_connection_attempts__(rc)) {
335 VLOG_INFO("%s: connecting...", rc->name);
337 rc->n_attempted_connections++;
338 retval = vconn_open(rc->target, OFP_VERSION, &rc->vconn);
340 rc->remote_ip = vconn_get_remote_ip(rc->vconn);
341 rc->local_ip = vconn_get_local_ip(rc->vconn);
342 rc->remote_port = vconn_get_remote_port(rc->vconn);
343 rc->backoff_deadline = time_now() + rc->backoff;
344 state_transition(rc, S_CONNECTING);
346 VLOG_WARN("%s: connection failed (%s)", rc->name, strerror(retval));
347 rc->backoff_deadline = TIME_MAX; /* Prevent resetting backoff. */
348 disconnect(rc, retval);
353 timeout_BACKOFF(const struct rconn *rc)
359 run_BACKOFF(struct rconn *rc)
367 timeout_CONNECTING(const struct rconn *rc)
369 return MAX(1, rc->backoff);
373 run_CONNECTING(struct rconn *rc)
375 int retval = vconn_connect(rc->vconn);
377 VLOG_INFO("%s: connected", rc->name);
378 rc->n_successful_connections++;
379 state_transition(rc, S_ACTIVE);
380 rc->last_connected = rc->state_entered;
381 } else if (retval != EAGAIN) {
382 if (rconn_logging_connection_attempts__(rc)) {
383 VLOG_INFO("%s: connection failed (%s)",
384 rc->name, strerror(retval));
386 disconnect(rc, retval);
387 } else if (timed_out(rc)) {
388 if (rconn_logging_connection_attempts__(rc)) {
389 VLOG_INFO("%s: connection timed out", rc->name);
391 rc->backoff_deadline = TIME_MAX; /* Prevent resetting backoff. */
392 disconnect(rc, ETIMEDOUT);
397 do_tx_work(struct rconn *rc)
399 if (list_is_empty(&rc->txq)) {
402 while (!list_is_empty(&rc->txq)) {
403 int error = try_send(rc);
408 if (list_is_empty(&rc->txq)) {
409 poll_immediate_wake();
414 timeout_ACTIVE(const struct rconn *rc)
416 if (rc->probe_interval) {
417 unsigned int base = MAX(rc->last_received, rc->state_entered);
418 unsigned int arg = base + rc->probe_interval - rc->state_entered;
425 run_ACTIVE(struct rconn *rc)
428 unsigned int base = MAX(rc->last_received, rc->state_entered);
429 VLOG_DBG("%s: idle %u seconds, sending inactivity probe",
430 rc->name, (unsigned int) (time_now() - base));
432 /* Ordering is important here: rconn_send() can transition to BACKOFF,
433 * and we don't want to transition back to IDLE if so, because then we
434 * can end up queuing a packet with vconn == NULL and then *boom*. */
435 state_transition(rc, S_IDLE);
436 rconn_send(rc, make_echo_request(), NULL);
444 timeout_IDLE(const struct rconn *rc)
446 return rc->probe_interval;
450 run_IDLE(struct rconn *rc)
453 VLOG_ERR("%s: no response to inactivity probe after %u "
454 "seconds, disconnecting",
455 rc->name, elapsed_in_this_state(rc));
456 disconnect(rc, ETIMEDOUT);
462 /* Performs whatever activities are necessary to maintain 'rc': if 'rc' is
463 * disconnected, attempts to (re)connect, backing off as necessary; if 'rc' is
464 * connected, attempts to send packets in the send queue, if any. */
466 rconn_run(struct rconn *rc)
472 vconn_run(rc->vconn);
474 for (i = 0; i < rc->n_monitors; i++) {
475 vconn_run(rc->monitors[i]);
479 old_state = rc->state;
481 #define STATE(NAME, VALUE) case S_##NAME: run_##NAME(rc); break;
487 } while (rc->state != old_state);
490 /* Causes the next call to poll_block() to wake up when rconn_run() should be
493 rconn_run_wait(struct rconn *rc)
499 vconn_run_wait(rc->vconn);
500 if ((rc->state & (S_ACTIVE | S_IDLE)) && !list_is_empty(&rc->txq)) {
501 vconn_wait(rc->vconn, WAIT_SEND);
504 for (i = 0; i < rc->n_monitors; i++) {
505 vconn_run_wait(rc->monitors[i]);
509 if (timeo != UINT_MAX) {
510 long long int expires = sat_add(rc->state_entered, timeo);
511 poll_timer_wait_until(expires * 1000);
515 /* Attempts to receive a packet from 'rc'. If successful, returns the packet;
516 * otherwise, returns a null pointer. The caller is responsible for freeing
517 * the packet (with ofpbuf_delete()). */
519 rconn_recv(struct rconn *rc)
521 if (rc->state & (S_ACTIVE | S_IDLE)) {
522 struct ofpbuf *buffer;
523 int error = vconn_recv(rc->vconn, &buffer);
525 copy_to_monitor(rc, buffer);
526 if (rc->probably_admitted || is_admitted_msg(buffer)
527 || time_now() - rc->last_connected >= 30) {
528 rc->probably_admitted = true;
529 rc->last_admitted = time_now();
531 rc->last_received = time_now();
532 rc->packets_received++;
533 if (rc->state == S_IDLE) {
534 state_transition(rc, S_ACTIVE);
537 } else if (error != EAGAIN) {
538 report_error(rc, error);
539 disconnect(rc, error);
545 /* Causes the next call to poll_block() to wake up when a packet may be ready
546 * to be received by vconn_recv() on 'rc'. */
548 rconn_recv_wait(struct rconn *rc)
551 vconn_wait(rc->vconn, WAIT_RECV);
555 /* Sends 'b' on 'rc'. Returns 0 if successful (in which case 'b' is
556 * destroyed), or ENOTCONN if 'rc' is not currently connected (in which case
557 * the caller retains ownership of 'b').
559 * If 'counter' is non-null, then 'counter' will be incremented while the
560 * packet is in flight, then decremented when it has been sent (or discarded
561 * due to disconnection). Because 'b' may be sent (or discarded) before this
562 * function returns, the caller may not be able to observe any change in
565 * There is no rconn_send_wait() function: an rconn has a send queue that it
566 * takes care of sending if you call rconn_run(), which will have the side
567 * effect of waking up poll_block(). */
569 rconn_send(struct rconn *rc, struct ofpbuf *b,
570 struct rconn_packet_counter *counter)
572 if (rconn_is_connected(rc)) {
573 COVERAGE_INC(rconn_queued);
574 copy_to_monitor(rc, b);
575 b->private_p = counter;
577 rconn_packet_counter_inc(counter);
579 list_push_back(&rc->txq, &b->list_node);
581 /* If the queue was empty before we added 'b', try to send some
582 * packets. (But if the queue had packets in it, it's because the
583 * vconn is backlogged and there's no point in stuffing more into it
584 * now. We'll get back to that in rconn_run().) */
585 if (rc->txq.next == &b->list_node) {
594 /* Sends 'b' on 'rc'. Increments 'counter' while the packet is in flight; it
595 * will be decremented when it has been sent (or discarded due to
596 * disconnection). Returns 0 if successful, EAGAIN if 'counter->n' is already
597 * at least as large as 'queue_limit', or ENOTCONN if 'rc' is not currently
598 * connected. Regardless of return value, 'b' is destroyed.
600 * Because 'b' may be sent (or discarded) before this function returns, the
601 * caller may not be able to observe any change in 'counter'.
603 * There is no rconn_send_wait() function: an rconn has a send queue that it
604 * takes care of sending if you call rconn_run(), which will have the side
605 * effect of waking up poll_block(). */
607 rconn_send_with_limit(struct rconn *rc, struct ofpbuf *b,
608 struct rconn_packet_counter *counter, int queue_limit)
611 retval = counter->n >= queue_limit ? EAGAIN : rconn_send(rc, b, counter);
613 COVERAGE_INC(rconn_overflow);
619 /* Returns the total number of packets successfully sent on the underlying
620 * vconn. A packet is not counted as sent while it is still queued in the
621 * rconn, only when it has been successfuly passed to the vconn. */
623 rconn_packets_sent(const struct rconn *rc)
625 return rc->packets_sent;
628 /* Adds 'vconn' to 'rc' as a monitoring connection, to which all messages sent
629 * and received on 'rconn' will be copied. 'rc' takes ownership of 'vconn'. */
631 rconn_add_monitor(struct rconn *rc, struct vconn *vconn)
633 if (rc->n_monitors < ARRAY_SIZE(rc->monitors)) {
634 VLOG_INFO("new monitor connection from %s", vconn_get_name(vconn));
635 rc->monitors[rc->n_monitors++] = vconn;
637 VLOG_DBG("too many monitor connections, discarding %s",
638 vconn_get_name(vconn));
643 /* Returns 'rc''s name. This is a name for human consumption, appropriate for
644 * use in log messages. It is not necessarily a name that may be passed
645 * directly to, e.g., vconn_open(). */
647 rconn_get_name(const struct rconn *rc)
652 /* Sets 'rc''s name to 'new_name'. */
654 rconn_set_name(struct rconn *rc, const char *new_name)
657 rc->name = xstrdup(new_name);
660 /* Returns 'rc''s target. This is intended to be a string that may be passed
661 * directly to, e.g., vconn_open(). */
663 rconn_get_target(const struct rconn *rc)
668 /* Returns true if 'rconn' is connected or in the process of reconnecting,
669 * false if 'rconn' is disconnected and will not reconnect on its own. */
671 rconn_is_alive(const struct rconn *rconn)
673 return rconn->state != S_VOID;
676 /* Returns true if 'rconn' is connected, false otherwise. */
678 rconn_is_connected(const struct rconn *rconn)
680 return is_connected_state(rconn->state);
683 /* Returns true if 'rconn' is connected and thought to have been accepted by
684 * the peer's admission-control policy. */
686 rconn_is_admitted(const struct rconn *rconn)
688 return (rconn_is_connected(rconn)
689 && rconn->last_admitted >= rconn->last_connected);
692 /* Returns 0 if 'rconn' is currently connected and considered to have been
693 * accepted by the peer's admission-control policy, otherwise the number of
694 * seconds since 'rconn' was last in such a state. */
696 rconn_failure_duration(const struct rconn *rconn)
698 return rconn_is_admitted(rconn) ? 0 : time_now() - rconn->last_admitted;
701 /* Returns the IP address of the peer, or 0 if the peer's IP address is not
704 rconn_get_remote_ip(const struct rconn *rconn)
706 return rconn->remote_ip;
709 /* Returns the transport port of the peer, or 0 if the peer's port is not
712 rconn_get_remote_port(const struct rconn *rconn)
714 return rconn->remote_port;
717 /* Returns the IP address used to connect to the peer, or 0 if the
718 * connection is not an IP-based protocol or if its IP address is not
721 rconn_get_local_ip(const struct rconn *rconn)
723 return rconn->local_ip;
726 /* Returns the transport port used to connect to the peer, or 0 if the
727 * connection does not contain a port or if the port is not known. */
729 rconn_get_local_port(const struct rconn *rconn)
731 return rconn->vconn ? vconn_get_local_port(rconn->vconn) : 0;
734 /* Returns the total number of packets successfully received by the underlying
737 rconn_packets_received(const struct rconn *rc)
739 return rc->packets_received;
742 /* Returns a string representing the internal state of 'rc'. The caller must
743 * not modify or free the string. */
745 rconn_get_state(const struct rconn *rc)
747 return state_name(rc->state);
750 /* Returns the number of connection attempts made by 'rc', including any
751 * ongoing attempt that has not yet succeeded or failed. */
753 rconn_get_attempted_connections(const struct rconn *rc)
755 return rc->n_attempted_connections;
758 /* Returns the number of successful connection attempts made by 'rc'. */
760 rconn_get_successful_connections(const struct rconn *rc)
762 return rc->n_successful_connections;
765 /* Returns the time at which the last successful connection was made by
766 * 'rc'. Returns TIME_MIN if never connected. */
768 rconn_get_last_connection(const struct rconn *rc)
770 return rc->last_connected;
773 /* Returns the time at which 'rc' was last disconnected. Returns TIME_MIN
774 * if never disconnected. */
776 rconn_get_last_disconnect(const struct rconn *rc)
778 return rc->last_disconnected;
781 /* Returns the time at which the last OpenFlow message was received by 'rc'.
782 * If no packets have been received on 'rc', returns the time at which 'rc'
785 rconn_get_last_received(const struct rconn *rc)
787 return rc->last_received;
790 /* Returns the time at which 'rc' was created. */
792 rconn_get_creation_time(const struct rconn *rc)
794 return rc->creation_time;
797 /* Returns the approximate number of seconds that 'rc' has been connected. */
799 rconn_get_total_time_connected(const struct rconn *rc)
801 return (rc->total_time_connected
802 + (rconn_is_connected(rc) ? elapsed_in_this_state(rc) : 0));
805 /* Returns the current amount of backoff, in seconds. This is the amount of
806 * time after which the rconn will transition from BACKOFF to CONNECTING. */
808 rconn_get_backoff(const struct rconn *rc)
813 /* Returns the number of seconds spent in this state so far. */
815 rconn_get_state_elapsed(const struct rconn *rc)
817 return elapsed_in_this_state(rc);
820 /* Returns 'rc''s current connection sequence number, a number that changes
821 * every time that 'rconn' connects or disconnects. */
823 rconn_get_connection_seqno(const struct rconn *rc)
828 /* Returns a value that explains why 'rc' last disconnected:
830 * - 0 means that the last disconnection was caused by a call to
831 * rconn_disconnect(), or that 'rc' is new and has not yet completed its
832 * initial connection or connection attempt.
834 * - EOF means that the connection was closed in the normal way by the peer.
836 * - A positive integer is an errno value that represents the error.
839 rconn_get_last_error(const struct rconn *rc)
841 return rc->last_error;
844 struct rconn_packet_counter *
845 rconn_packet_counter_create(void)
847 struct rconn_packet_counter *c = xmalloc(sizeof *c);
854 rconn_packet_counter_destroy(struct rconn_packet_counter *c)
857 assert(c->ref_cnt > 0);
858 if (!--c->ref_cnt && !c->n) {
865 rconn_packet_counter_inc(struct rconn_packet_counter *c)
871 rconn_packet_counter_dec(struct rconn_packet_counter *c)
874 if (!--c->n && !c->ref_cnt) {
879 /* Set rc->target and rc->name to 'target' and 'name', respectively. If 'name'
880 * is null, 'target' is used.
882 * Also, clear out the cached IP address and port information, since changing
883 * the target also likely changes these values. */
885 rconn_set_target__(struct rconn *rc, const char *target, const char *name)
888 rc->name = xstrdup(name ? name : target);
890 rc->target = xstrdup(target);
896 /* Tries to send a packet from 'rc''s send buffer. Returns 0 if successful,
897 * otherwise a positive errno value. */
899 try_send(struct rconn *rc)
901 struct ofpbuf *msg = ofpbuf_from_list(rc->txq.next);
902 struct rconn_packet_counter *counter = msg->private_p;
905 /* Eagerly remove 'msg' from the txq. We can't remove it from the list
906 * after sending, if sending is successful, because it is then owned by the
907 * vconn, which might have freed it already. */
908 list_remove(&msg->list_node);
910 retval = vconn_send(rc->vconn, msg);
912 list_push_front(&rc->txq, &msg->list_node);
913 if (retval != EAGAIN) {
914 report_error(rc, retval);
915 disconnect(rc, retval);
919 COVERAGE_INC(rconn_sent);
922 rconn_packet_counter_dec(counter);
927 /* Reports that 'error' caused 'rc' to disconnect. 'error' may be a positive
928 * errno value, or it may be EOF to indicate that the connection was closed
931 report_error(struct rconn *rc, int error)
934 /* If 'rc' isn't reliable, then we don't really expect this connection
935 * to last forever anyway (probably it's a connection that we received
936 * via accept()), so use DBG level to avoid cluttering the logs. */
937 enum vlog_level level = rc->reliable ? VLL_INFO : VLL_DBG;
938 VLOG(level, "%s: connection closed by peer", rc->name);
940 VLOG_WARN("%s: connection dropped (%s)", rc->name, strerror(error));
944 /* Disconnects 'rc' and records 'error' as the error that caused 'rc''s last
947 * - 0 means that this disconnection is due to a request by 'rc''s client,
948 * not due to any kind of network error.
950 * - EOF means that the connection was closed in the normal way by the peer.
952 * - A positive integer is an errno value that represents the error.
955 disconnect(struct rconn *rc, int error)
957 rc->last_error = error;
959 time_t now = time_now();
961 if (rc->state & (S_CONNECTING | S_ACTIVE | S_IDLE)) {
962 rc->last_disconnected = now;
963 vconn_close(rc->vconn);
968 if (now >= rc->backoff_deadline) {
970 } else if (rc->backoff < rc->max_backoff / 2) {
971 rc->backoff = MAX(1, 2 * rc->backoff);
972 VLOG_INFO("%s: waiting %d seconds before reconnect",
973 rc->name, rc->backoff);
975 if (rconn_logging_connection_attempts__(rc)) {
976 VLOG_INFO("%s: continuing to retry connections in the "
977 "background but suppressing further logging",
980 rc->backoff = rc->max_backoff;
982 rc->backoff_deadline = now + rc->backoff;
983 state_transition(rc, S_BACKOFF);
985 rc->last_disconnected = time_now();
986 rconn_disconnect(rc);
990 /* Drops all the packets from 'rc''s send queue and decrements their queue
993 flush_queue(struct rconn *rc)
995 if (list_is_empty(&rc->txq)) {
998 while (!list_is_empty(&rc->txq)) {
999 struct ofpbuf *b = ofpbuf_from_list(list_pop_front(&rc->txq));
1000 struct rconn_packet_counter *counter = b->private_p;
1002 rconn_packet_counter_dec(counter);
1004 COVERAGE_INC(rconn_discarded);
1007 poll_immediate_wake();
1011 elapsed_in_this_state(const struct rconn *rc)
1013 return time_now() - rc->state_entered;
1017 timeout(const struct rconn *rc)
1019 switch (rc->state) {
1020 #define STATE(NAME, VALUE) case S_##NAME: return timeout_##NAME(rc);
1029 timed_out(const struct rconn *rc)
1031 return time_now() >= sat_add(rc->state_entered, timeout(rc));
1035 state_transition(struct rconn *rc, enum state state)
1037 rc->seqno += (rc->state == S_ACTIVE) != (state == S_ACTIVE);
1038 if (is_connected_state(state) && !is_connected_state(rc->state)) {
1039 rc->probably_admitted = false;
1041 if (rconn_is_connected(rc)) {
1042 rc->total_time_connected += elapsed_in_this_state(rc);
1044 VLOG_DBG("%s: entering %s", rc->name, state_name(state));
1046 rc->state_entered = time_now();
1050 copy_to_monitor(struct rconn *rc, const struct ofpbuf *b)
1052 struct ofpbuf *clone = NULL;
1056 for (i = 0; i < rc->n_monitors; ) {
1057 struct vconn *vconn = rc->monitors[i];
1060 clone = ofpbuf_clone(b);
1062 retval = vconn_send(vconn, clone);
1065 } else if (retval != EAGAIN) {
1066 VLOG_DBG("%s: closing monitor connection to %s: %s",
1067 rconn_get_name(rc), vconn_get_name(vconn),
1069 rc->monitors[i] = rc->monitors[--rc->n_monitors];
1074 ofpbuf_delete(clone);
1078 is_connected_state(enum state state)
1080 return (state & (S_ACTIVE | S_IDLE)) != 0;
1084 is_admitted_msg(const struct ofpbuf *b)
1086 struct ofp_header *oh = b->data;
1087 uint8_t type = oh->type;
1089 && (1u << type) & ((1u << OFPT_HELLO) |
1090 (1u << OFPT_ERROR) |
1091 (1u << OFPT_ECHO_REQUEST) |
1092 (1u << OFPT_ECHO_REPLY) |
1093 (1u << OFPT_VENDOR) |
1094 (1u << OFPT_FEATURES_REQUEST) |
1095 (1u << OFPT_FEATURES_REPLY) |
1096 (1u << OFPT_GET_CONFIG_REQUEST) |
1097 (1u << OFPT_GET_CONFIG_REPLY) |
1098 (1u << OFPT_SET_CONFIG)));
1101 /* Returns true if 'rc' is currently logging information about connection
1102 * attempts, false if logging should be suppressed because 'rc' hasn't
1103 * successuflly connected in too long. */
1105 rconn_logging_connection_attempts__(const struct rconn *rc)
1107 return rc->backoff < rc->max_backoff;