2 * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
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 ovs_be32 local_ip, remote_ip;
123 ovs_be16 remote_port;
126 /* Messages sent or received are copied to the monitor connections. */
127 #define MAX_MONITORS 8
128 struct vconn *monitors[8];
132 static unsigned int elapsed_in_this_state(const struct rconn *);
133 static unsigned int timeout(const struct rconn *);
134 static bool timed_out(const struct rconn *);
135 static void state_transition(struct rconn *, enum state);
136 static void rconn_set_target__(struct rconn *,
137 const char *target, const char *name);
138 static int try_send(struct rconn *);
139 static void reconnect(struct rconn *);
140 static void report_error(struct rconn *, int error);
141 static void disconnect(struct rconn *, int error);
142 static void flush_queue(struct rconn *);
143 static void copy_to_monitor(struct rconn *, const struct ofpbuf *);
144 static bool is_connected_state(enum state);
145 static bool is_admitted_msg(const struct ofpbuf *);
146 static bool rconn_logging_connection_attempts__(const struct rconn *);
148 /* Creates and returns a new rconn.
150 * 'probe_interval' is a number of seconds. If the interval passes once
151 * without an OpenFlow message being received from the peer, the rconn sends
152 * out an "echo request" message. If the interval passes again without a
153 * message being received, the rconn disconnects and re-connects to the peer.
154 * Setting 'probe_interval' to 0 disables this behavior.
156 * 'max_backoff' is the maximum number of seconds between attempts to connect
157 * to the peer. The actual interval starts at 1 second and doubles on each
158 * failure until it reaches 'max_backoff'. If 0 is specified, the default of
161 * The new rconn is initially unconnected. Use rconn_connect() or
162 * rconn_connect_unreliably() to connect it. */
164 rconn_create(int probe_interval, int max_backoff, uint8_t dscp)
166 struct rconn *rc = xzalloc(sizeof *rc);
169 rc->state_entered = time_now();
172 rc->name = xstrdup("void");
173 rc->target = xstrdup("void");
174 rc->reliable = false;
179 rc->max_backoff = max_backoff ? max_backoff : 8;
180 rc->backoff_deadline = TIME_MIN;
181 rc->last_received = time_now();
182 rc->last_connected = TIME_MIN;
183 rc->last_disconnected = TIME_MIN;
186 rc->packets_sent = 0;
188 rc->probably_admitted = false;
189 rc->last_admitted = time_now();
191 rc->packets_received = 0;
192 rc->n_attempted_connections = 0;
193 rc->n_successful_connections = 0;
194 rc->creation_time = time_now();
195 rc->total_time_connected = 0;
197 rconn_set_probe_interval(rc, probe_interval);
198 rconn_set_dscp(rc, dscp);
206 rconn_set_max_backoff(struct rconn *rc, int max_backoff)
208 rc->max_backoff = MAX(1, max_backoff);
209 if (rc->state == S_BACKOFF && rc->backoff > max_backoff) {
210 rc->backoff = max_backoff;
211 if (rc->backoff_deadline > time_now() + max_backoff) {
212 rc->backoff_deadline = time_now() + max_backoff;
218 rconn_get_max_backoff(const struct rconn *rc)
220 return rc->max_backoff;
224 rconn_set_dscp(struct rconn *rc, uint8_t dscp)
230 rconn_get_dscp(const struct rconn *rc)
236 rconn_set_probe_interval(struct rconn *rc, int probe_interval)
238 rc->probe_interval = probe_interval ? MAX(5, probe_interval) : 0;
242 rconn_get_probe_interval(const struct rconn *rc)
244 return rc->probe_interval;
247 /* Drops any existing connection on 'rc', then sets up 'rc' to connect to
248 * 'target' and reconnect as needed. 'target' should be a remote OpenFlow
249 * target in a form acceptable to vconn_open().
251 * If 'name' is nonnull, then it is used in log messages in place of 'target'.
252 * It should presumably give more information to a human reader than 'target',
253 * but it need not be acceptable to vconn_open(). */
255 rconn_connect(struct rconn *rc, const char *target, const char *name)
257 rconn_disconnect(rc);
258 rconn_set_target__(rc, target, name);
263 /* Drops any existing connection on 'rc', then configures 'rc' to use
264 * 'vconn'. If the connection on 'vconn' drops, 'rc' will not reconnect on it
267 * By default, the target obtained from vconn_get_name(vconn) is used in log
268 * messages. If 'name' is nonnull, then it is used instead. It should
269 * presumably give more information to a human reader than the target, but it
270 * need not be acceptable to vconn_open(). */
272 rconn_connect_unreliably(struct rconn *rc,
273 struct vconn *vconn, const char *name)
275 assert(vconn != NULL);
276 rconn_disconnect(rc);
277 rconn_set_target__(rc, vconn_get_name(vconn), name);
278 rc->reliable = false;
280 rc->last_connected = time_now();
281 state_transition(rc, S_ACTIVE);
284 /* If 'rc' is connected, forces it to drop the connection and reconnect. */
286 rconn_reconnect(struct rconn *rc)
288 if (rc->state & (S_ACTIVE | S_IDLE)) {
289 VLOG_INFO("%s: disconnecting", rc->name);
295 rconn_disconnect(struct rconn *rc)
297 if (rc->state != S_VOID) {
299 vconn_close(rc->vconn);
302 rconn_set_target__(rc, "void", NULL);
303 rc->reliable = false;
306 rc->backoff_deadline = TIME_MIN;
308 state_transition(rc, S_VOID);
312 /* Disconnects 'rc' and frees the underlying storage. */
314 rconn_destroy(struct rconn *rc)
321 vconn_close(rc->vconn);
323 ofpbuf_list_delete(&rc->txq);
324 for (i = 0; i < rc->n_monitors; i++) {
325 vconn_close(rc->monitors[i]);
332 timeout_VOID(const struct rconn *rc OVS_UNUSED)
338 run_VOID(struct rconn *rc OVS_UNUSED)
344 reconnect(struct rconn *rc)
348 if (rconn_logging_connection_attempts__(rc)) {
349 VLOG_INFO("%s: connecting...", rc->name);
351 rc->n_attempted_connections++;
352 retval = vconn_open(rc->target, OFP10_VERSION, &rc->vconn, rc->dscp);
354 rc->remote_ip = vconn_get_remote_ip(rc->vconn);
355 rc->local_ip = vconn_get_local_ip(rc->vconn);
356 rc->remote_port = vconn_get_remote_port(rc->vconn);
357 rc->backoff_deadline = time_now() + rc->backoff;
358 state_transition(rc, S_CONNECTING);
360 VLOG_WARN("%s: connection failed (%s)", rc->name, strerror(retval));
361 rc->backoff_deadline = TIME_MAX; /* Prevent resetting backoff. */
362 disconnect(rc, retval);
367 timeout_BACKOFF(const struct rconn *rc)
373 run_BACKOFF(struct rconn *rc)
381 timeout_CONNECTING(const struct rconn *rc)
383 return MAX(1, rc->backoff);
387 run_CONNECTING(struct rconn *rc)
389 int retval = vconn_connect(rc->vconn);
391 VLOG_INFO("%s: connected", rc->name);
392 rc->n_successful_connections++;
393 state_transition(rc, S_ACTIVE);
394 rc->last_connected = rc->state_entered;
395 } else if (retval != EAGAIN) {
396 if (rconn_logging_connection_attempts__(rc)) {
397 VLOG_INFO("%s: connection failed (%s)",
398 rc->name, strerror(retval));
400 disconnect(rc, retval);
401 } else if (timed_out(rc)) {
402 if (rconn_logging_connection_attempts__(rc)) {
403 VLOG_INFO("%s: connection timed out", rc->name);
405 rc->backoff_deadline = TIME_MAX; /* Prevent resetting backoff. */
406 disconnect(rc, ETIMEDOUT);
411 do_tx_work(struct rconn *rc)
413 if (list_is_empty(&rc->txq)) {
416 while (!list_is_empty(&rc->txq)) {
417 int error = try_send(rc);
422 if (list_is_empty(&rc->txq)) {
423 poll_immediate_wake();
428 timeout_ACTIVE(const struct rconn *rc)
430 if (rc->probe_interval) {
431 unsigned int base = MAX(rc->last_received, rc->state_entered);
432 unsigned int arg = base + rc->probe_interval - rc->state_entered;
439 run_ACTIVE(struct rconn *rc)
442 unsigned int base = MAX(rc->last_received, rc->state_entered);
443 VLOG_DBG("%s: idle %u seconds, sending inactivity probe",
444 rc->name, (unsigned int) (time_now() - base));
446 /* Ordering is important here: rconn_send() can transition to BACKOFF,
447 * and we don't want to transition back to IDLE if so, because then we
448 * can end up queuing a packet with vconn == NULL and then *boom*. */
449 state_transition(rc, S_IDLE);
450 rconn_send(rc, make_echo_request(), NULL);
458 timeout_IDLE(const struct rconn *rc)
460 return rc->probe_interval;
464 run_IDLE(struct rconn *rc)
467 VLOG_ERR("%s: no response to inactivity probe after %u "
468 "seconds, disconnecting",
469 rc->name, elapsed_in_this_state(rc));
470 disconnect(rc, ETIMEDOUT);
476 /* Performs whatever activities are necessary to maintain 'rc': if 'rc' is
477 * disconnected, attempts to (re)connect, backing off as necessary; if 'rc' is
478 * connected, attempts to send packets in the send queue, if any. */
480 rconn_run(struct rconn *rc)
486 vconn_run(rc->vconn);
488 for (i = 0; i < rc->n_monitors; i++) {
489 vconn_run(rc->monitors[i]);
493 old_state = rc->state;
495 #define STATE(NAME, VALUE) case S_##NAME: run_##NAME(rc); break;
501 } while (rc->state != old_state);
504 /* Causes the next call to poll_block() to wake up when rconn_run() should be
507 rconn_run_wait(struct rconn *rc)
513 vconn_run_wait(rc->vconn);
514 if ((rc->state & (S_ACTIVE | S_IDLE)) && !list_is_empty(&rc->txq)) {
515 vconn_wait(rc->vconn, WAIT_SEND);
518 for (i = 0; i < rc->n_monitors; i++) {
519 vconn_run_wait(rc->monitors[i]);
523 if (timeo != UINT_MAX) {
524 long long int expires = sat_add(rc->state_entered, timeo);
525 poll_timer_wait_until(expires * 1000);
529 /* Attempts to receive a packet from 'rc'. If successful, returns the packet;
530 * otherwise, returns a null pointer. The caller is responsible for freeing
531 * the packet (with ofpbuf_delete()). */
533 rconn_recv(struct rconn *rc)
535 if (rc->state & (S_ACTIVE | S_IDLE)) {
536 struct ofpbuf *buffer;
537 int error = vconn_recv(rc->vconn, &buffer);
539 copy_to_monitor(rc, buffer);
540 if (rc->probably_admitted || is_admitted_msg(buffer)
541 || time_now() - rc->last_connected >= 30) {
542 rc->probably_admitted = true;
543 rc->last_admitted = time_now();
545 rc->last_received = time_now();
546 rc->packets_received++;
547 if (rc->state == S_IDLE) {
548 state_transition(rc, S_ACTIVE);
551 } else if (error != EAGAIN) {
552 report_error(rc, error);
553 disconnect(rc, error);
559 /* Causes the next call to poll_block() to wake up when a packet may be ready
560 * to be received by vconn_recv() on 'rc'. */
562 rconn_recv_wait(struct rconn *rc)
565 vconn_wait(rc->vconn, WAIT_RECV);
569 /* Sends 'b' on 'rc'. Returns 0 if successful, or ENOTCONN if 'rc' is not
570 * currently connected. Takes ownership of 'b'.
572 * If 'counter' is non-null, then 'counter' will be incremented while the
573 * packet is in flight, then decremented when it has been sent (or discarded
574 * due to disconnection). Because 'b' may be sent (or discarded) before this
575 * function returns, the caller may not be able to observe any change in
578 * There is no rconn_send_wait() function: an rconn has a send queue that it
579 * takes care of sending if you call rconn_run(), which will have the side
580 * effect of waking up poll_block(). */
582 rconn_send(struct rconn *rc, struct ofpbuf *b,
583 struct rconn_packet_counter *counter)
585 if (rconn_is_connected(rc)) {
586 COVERAGE_INC(rconn_queued);
587 copy_to_monitor(rc, b);
588 b->private_p = counter;
590 rconn_packet_counter_inc(counter);
592 list_push_back(&rc->txq, &b->list_node);
594 /* If the queue was empty before we added 'b', try to send some
595 * packets. (But if the queue had packets in it, it's because the
596 * vconn is backlogged and there's no point in stuffing more into it
597 * now. We'll get back to that in rconn_run().) */
598 if (rc->txq.next == &b->list_node) {
608 /* Sends 'b' on 'rc'. Increments 'counter' while the packet is in flight; it
609 * will be decremented when it has been sent (or discarded due to
610 * disconnection). Returns 0 if successful, EAGAIN if 'counter->n' is already
611 * at least as large as 'queue_limit', or ENOTCONN if 'rc' is not currently
612 * connected. Regardless of return value, 'b' is destroyed.
614 * Because 'b' may be sent (or discarded) before this function returns, the
615 * caller may not be able to observe any change in 'counter'.
617 * There is no rconn_send_wait() function: an rconn has a send queue that it
618 * takes care of sending if you call rconn_run(), which will have the side
619 * effect of waking up poll_block(). */
621 rconn_send_with_limit(struct rconn *rc, struct ofpbuf *b,
622 struct rconn_packet_counter *counter, int queue_limit)
625 retval = counter->n >= queue_limit ? EAGAIN : rconn_send(rc, b, counter);
627 COVERAGE_INC(rconn_overflow);
632 /* Returns the total number of packets successfully sent on the underlying
633 * vconn. A packet is not counted as sent while it is still queued in the
634 * rconn, only when it has been successfuly passed to the vconn. */
636 rconn_packets_sent(const struct rconn *rc)
638 return rc->packets_sent;
641 /* Adds 'vconn' to 'rc' as a monitoring connection, to which all messages sent
642 * and received on 'rconn' will be copied. 'rc' takes ownership of 'vconn'. */
644 rconn_add_monitor(struct rconn *rc, struct vconn *vconn)
646 if (rc->n_monitors < ARRAY_SIZE(rc->monitors)) {
647 VLOG_INFO("new monitor connection from %s", vconn_get_name(vconn));
648 rc->monitors[rc->n_monitors++] = vconn;
650 VLOG_DBG("too many monitor connections, discarding %s",
651 vconn_get_name(vconn));
656 /* Returns 'rc''s name. This is a name for human consumption, appropriate for
657 * use in log messages. It is not necessarily a name that may be passed
658 * directly to, e.g., vconn_open(). */
660 rconn_get_name(const struct rconn *rc)
665 /* Sets 'rc''s name to 'new_name'. */
667 rconn_set_name(struct rconn *rc, const char *new_name)
670 rc->name = xstrdup(new_name);
673 /* Returns 'rc''s target. This is intended to be a string that may be passed
674 * directly to, e.g., vconn_open(). */
676 rconn_get_target(const struct rconn *rc)
681 /* Returns true if 'rconn' is connected or in the process of reconnecting,
682 * false if 'rconn' is disconnected and will not reconnect on its own. */
684 rconn_is_alive(const struct rconn *rconn)
686 return rconn->state != S_VOID;
689 /* Returns true if 'rconn' is connected, false otherwise. */
691 rconn_is_connected(const struct rconn *rconn)
693 return is_connected_state(rconn->state);
696 /* Returns true if 'rconn' is connected and thought to have been accepted by
697 * the peer's admission-control policy. */
699 rconn_is_admitted(const struct rconn *rconn)
701 return (rconn_is_connected(rconn)
702 && rconn->last_admitted >= rconn->last_connected);
705 /* Returns 0 if 'rconn' is currently connected and considered to have been
706 * accepted by the peer's admission-control policy, otherwise the number of
707 * seconds since 'rconn' was last in such a state. */
709 rconn_failure_duration(const struct rconn *rconn)
711 return rconn_is_admitted(rconn) ? 0 : time_now() - rconn->last_admitted;
714 /* Returns the IP address of the peer, or 0 if the peer's IP address is not
717 rconn_get_remote_ip(const struct rconn *rconn)
719 return rconn->remote_ip;
722 /* Returns the transport port of the peer, or 0 if the peer's port is not
725 rconn_get_remote_port(const struct rconn *rconn)
727 return rconn->remote_port;
730 /* Returns the IP address used to connect to the peer, or 0 if the
731 * connection is not an IP-based protocol or if its IP address is not
734 rconn_get_local_ip(const struct rconn *rconn)
736 return rconn->local_ip;
739 /* Returns the transport port used to connect to the peer, or 0 if the
740 * connection does not contain a port or if the port is not known. */
742 rconn_get_local_port(const struct rconn *rconn)
744 return rconn->vconn ? vconn_get_local_port(rconn->vconn) : 0;
747 /* Returns the OpenFlow version negotiated with the peer, or -1 if there is
748 * currently no connection or if version negotiation is not yet complete. */
750 rconn_get_version(const struct rconn *rconn)
752 return rconn->vconn ? vconn_get_version(rconn->vconn) : -1;
755 /* Returns the total number of packets successfully received by the underlying
758 rconn_packets_received(const struct rconn *rc)
760 return rc->packets_received;
763 /* Returns a string representing the internal state of 'rc'. The caller must
764 * not modify or free the string. */
766 rconn_get_state(const struct rconn *rc)
768 return state_name(rc->state);
771 /* Returns the number of connection attempts made by 'rc', including any
772 * ongoing attempt that has not yet succeeded or failed. */
774 rconn_get_attempted_connections(const struct rconn *rc)
776 return rc->n_attempted_connections;
779 /* Returns the number of successful connection attempts made by 'rc'. */
781 rconn_get_successful_connections(const struct rconn *rc)
783 return rc->n_successful_connections;
786 /* Returns the time at which the last successful connection was made by
787 * 'rc'. Returns TIME_MIN if never connected. */
789 rconn_get_last_connection(const struct rconn *rc)
791 return rc->last_connected;
794 /* Returns the time at which 'rc' was last disconnected. Returns TIME_MIN
795 * if never disconnected. */
797 rconn_get_last_disconnect(const struct rconn *rc)
799 return rc->last_disconnected;
802 /* Returns the time at which the last OpenFlow message was received by 'rc'.
803 * If no packets have been received on 'rc', returns the time at which 'rc'
806 rconn_get_last_received(const struct rconn *rc)
808 return rc->last_received;
811 /* Returns the time at which 'rc' was created. */
813 rconn_get_creation_time(const struct rconn *rc)
815 return rc->creation_time;
818 /* Returns the approximate number of seconds that 'rc' has been connected. */
820 rconn_get_total_time_connected(const struct rconn *rc)
822 return (rc->total_time_connected
823 + (rconn_is_connected(rc) ? elapsed_in_this_state(rc) : 0));
826 /* Returns the current amount of backoff, in seconds. This is the amount of
827 * time after which the rconn will transition from BACKOFF to CONNECTING. */
829 rconn_get_backoff(const struct rconn *rc)
834 /* Returns the number of seconds spent in this state so far. */
836 rconn_get_state_elapsed(const struct rconn *rc)
838 return elapsed_in_this_state(rc);
841 /* Returns 'rc''s current connection sequence number, a number that changes
842 * every time that 'rconn' connects or disconnects. */
844 rconn_get_connection_seqno(const struct rconn *rc)
849 /* Returns a value that explains why 'rc' last disconnected:
851 * - 0 means that the last disconnection was caused by a call to
852 * rconn_disconnect(), or that 'rc' is new and has not yet completed its
853 * initial connection or connection attempt.
855 * - EOF means that the connection was closed in the normal way by the peer.
857 * - A positive integer is an errno value that represents the error.
860 rconn_get_last_error(const struct rconn *rc)
862 return rc->last_error;
865 /* Returns the number of messages queued for transmission on 'rc'. */
867 rconn_count_txqlen(const struct rconn *rc)
869 return list_size(&rc->txq);
872 struct rconn_packet_counter *
873 rconn_packet_counter_create(void)
875 struct rconn_packet_counter *c = xmalloc(sizeof *c);
882 rconn_packet_counter_destroy(struct rconn_packet_counter *c)
885 assert(c->ref_cnt > 0);
886 if (!--c->ref_cnt && !c->n) {
893 rconn_packet_counter_inc(struct rconn_packet_counter *c)
899 rconn_packet_counter_dec(struct rconn_packet_counter *c)
902 if (!--c->n && !c->ref_cnt) {
907 /* Set rc->target and rc->name to 'target' and 'name', respectively. If 'name'
908 * is null, 'target' is used.
910 * Also, clear out the cached IP address and port information, since changing
911 * the target also likely changes these values. */
913 rconn_set_target__(struct rconn *rc, const char *target, const char *name)
916 rc->name = xstrdup(name ? name : target);
918 rc->target = xstrdup(target);
924 /* Tries to send a packet from 'rc''s send buffer. Returns 0 if successful,
925 * otherwise a positive errno value. */
927 try_send(struct rconn *rc)
929 struct ofpbuf *msg = ofpbuf_from_list(rc->txq.next);
930 struct rconn_packet_counter *counter = msg->private_p;
933 /* Eagerly remove 'msg' from the txq. We can't remove it from the list
934 * after sending, if sending is successful, because it is then owned by the
935 * vconn, which might have freed it already. */
936 list_remove(&msg->list_node);
938 retval = vconn_send(rc->vconn, msg);
940 list_push_front(&rc->txq, &msg->list_node);
941 if (retval != EAGAIN) {
942 report_error(rc, retval);
943 disconnect(rc, retval);
947 COVERAGE_INC(rconn_sent);
950 rconn_packet_counter_dec(counter);
955 /* Reports that 'error' caused 'rc' to disconnect. 'error' may be a positive
956 * errno value, or it may be EOF to indicate that the connection was closed
959 report_error(struct rconn *rc, int error)
962 /* If 'rc' isn't reliable, then we don't really expect this connection
963 * to last forever anyway (probably it's a connection that we received
964 * via accept()), so use DBG level to avoid cluttering the logs. */
965 enum vlog_level level = rc->reliable ? VLL_INFO : VLL_DBG;
966 VLOG(level, "%s: connection closed by peer", rc->name);
968 VLOG_WARN("%s: connection dropped (%s)", rc->name, strerror(error));
972 /* Disconnects 'rc' and records 'error' as the error that caused 'rc''s last
975 * - 0 means that this disconnection is due to a request by 'rc''s client,
976 * not due to any kind of network error.
978 * - EOF means that the connection was closed in the normal way by the peer.
980 * - A positive integer is an errno value that represents the error.
983 disconnect(struct rconn *rc, int error)
985 rc->last_error = error;
987 time_t now = time_now();
989 if (rc->state & (S_CONNECTING | S_ACTIVE | S_IDLE)) {
990 rc->last_disconnected = now;
991 vconn_close(rc->vconn);
996 if (now >= rc->backoff_deadline) {
998 } else if (rc->backoff < rc->max_backoff / 2) {
999 rc->backoff = MAX(1, 2 * rc->backoff);
1000 VLOG_INFO("%s: waiting %d seconds before reconnect",
1001 rc->name, rc->backoff);
1003 if (rconn_logging_connection_attempts__(rc)) {
1004 VLOG_INFO("%s: continuing to retry connections in the "
1005 "background but suppressing further logging",
1008 rc->backoff = rc->max_backoff;
1010 rc->backoff_deadline = now + rc->backoff;
1011 state_transition(rc, S_BACKOFF);
1013 rc->last_disconnected = time_now();
1014 rconn_disconnect(rc);
1018 /* Drops all the packets from 'rc''s send queue and decrements their queue
1021 flush_queue(struct rconn *rc)
1023 if (list_is_empty(&rc->txq)) {
1026 while (!list_is_empty(&rc->txq)) {
1027 struct ofpbuf *b = ofpbuf_from_list(list_pop_front(&rc->txq));
1028 struct rconn_packet_counter *counter = b->private_p;
1030 rconn_packet_counter_dec(counter);
1032 COVERAGE_INC(rconn_discarded);
1035 poll_immediate_wake();
1039 elapsed_in_this_state(const struct rconn *rc)
1041 return time_now() - rc->state_entered;
1045 timeout(const struct rconn *rc)
1047 switch (rc->state) {
1048 #define STATE(NAME, VALUE) case S_##NAME: return timeout_##NAME(rc);
1057 timed_out(const struct rconn *rc)
1059 return time_now() >= sat_add(rc->state_entered, timeout(rc));
1063 state_transition(struct rconn *rc, enum state state)
1065 rc->seqno += (rc->state == S_ACTIVE) != (state == S_ACTIVE);
1066 if (is_connected_state(state) && !is_connected_state(rc->state)) {
1067 rc->probably_admitted = false;
1069 if (rconn_is_connected(rc)) {
1070 rc->total_time_connected += elapsed_in_this_state(rc);
1072 VLOG_DBG("%s: entering %s", rc->name, state_name(state));
1074 rc->state_entered = time_now();
1078 copy_to_monitor(struct rconn *rc, const struct ofpbuf *b)
1080 struct ofpbuf *clone = NULL;
1084 for (i = 0; i < rc->n_monitors; ) {
1085 struct vconn *vconn = rc->monitors[i];
1088 clone = ofpbuf_clone(b);
1090 retval = vconn_send(vconn, clone);
1093 } else if (retval != EAGAIN) {
1094 VLOG_DBG("%s: closing monitor connection to %s: %s",
1095 rconn_get_name(rc), vconn_get_name(vconn),
1097 rc->monitors[i] = rc->monitors[--rc->n_monitors];
1102 ofpbuf_delete(clone);
1106 is_connected_state(enum state state)
1108 return (state & (S_ACTIVE | S_IDLE)) != 0;
1112 is_admitted_msg(const struct ofpbuf *b)
1114 struct ofp_header *oh = b->data;
1115 uint8_t type = oh->type;
1117 && (1u << type) & ((1u << OFPT_HELLO) |
1118 (1u << OFPT_ERROR) |
1119 (1u << OFPT_ECHO_REQUEST) |
1120 (1u << OFPT_ECHO_REPLY) |
1121 (1u << OFPT_VENDOR) |
1122 (1u << OFPT_FEATURES_REQUEST) |
1123 (1u << OFPT_FEATURES_REPLY) |
1124 (1u << OFPT_GET_CONFIG_REQUEST) |
1125 (1u << OFPT_GET_CONFIG_REPLY) |
1126 (1u << OFPT_SET_CONFIG)));
1129 /* Returns true if 'rc' is currently logging information about connection
1130 * attempts, false if logging should be suppressed because 'rc' hasn't
1131 * successuflly connected in too long. */
1133 rconn_logging_connection_attempts__(const struct rconn *rc)
1135 return rc->backoff < rc->max_backoff;