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1 : : /*
2 : : * Copyright (c) 2008, 2009, 2010, 2012, 2013 Nicira, Inc.
3 : : *
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:
7 : : *
8 : : * http://www.apache.org/licenses/LICENSE-2.0
9 : : *
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.
15 : : */
16 : :
17 : : #include <config.h>
18 : : #include "reconnect.h"
19 : :
20 : : #include <stdlib.h>
21 : :
22 : : #include "poll-loop.h"
23 : : #include "util.h"
24 : : #include "openvswitch/vlog.h"
25 : :
26 : 53956 : VLOG_DEFINE_THIS_MODULE(reconnect);
27 : :
28 : : #define STATES \
29 : : STATE(VOID, 1 << 0) \
30 : : STATE(BACKOFF, 1 << 1) \
31 : : STATE(CONNECTING, 1 << 3) \
32 : : STATE(ACTIVE, 1 << 4) \
33 : : STATE(IDLE, 1 << 5) \
34 : : STATE(RECONNECT, 1 << 6) \
35 : : STATE(LISTENING, 1 << 7)
36 : : enum state {
37 : : #define STATE(NAME, VALUE) S_##NAME = VALUE,
38 : : STATES
39 : : #undef STATE
40 : : };
41 : :
42 : : static bool
43 : 202985 : is_connected_state(enum state state)
44 : : {
45 : 202985 : return (state & (S_ACTIVE | S_IDLE)) != 0;
46 : : }
47 : :
48 : : struct reconnect {
49 : : /* Configuration. */
50 : : char *name;
51 : : int min_backoff;
52 : : int max_backoff;
53 : : int probe_interval;
54 : : bool passive;
55 : : enum vlog_level info; /* Used for informational messages. */
56 : :
57 : : /* State. */
58 : : enum state state;
59 : : long long int state_entered;
60 : : int backoff;
61 : : long long int last_activity;
62 : : long long int last_connected;
63 : : long long int last_disconnected;
64 : : unsigned int max_tries;
65 : :
66 : : /* These values are simply for statistics reporting, not otherwise used
67 : : * directly by anything internal. */
68 : : long long int creation_time;
69 : : unsigned int n_attempted_connections, n_successful_connections;
70 : : unsigned int total_connected_duration;
71 : : unsigned int seqno;
72 : : };
73 : :
74 : : static void reconnect_transition__(struct reconnect *, long long int now,
75 : : enum state state);
76 : : static long long int reconnect_deadline__(const struct reconnect *);
77 : : static bool reconnect_may_retry(struct reconnect *);
78 : :
79 : : static const char *
80 : 290 : reconnect_state_name__(enum state state)
81 : : {
82 [ + + + + : 290 : switch (state) {
+ - + - ]
83 : : #define STATE(NAME, VALUE) case S_##NAME: return #NAME;
84 : 290 : STATES
85 : : #undef STATE
86 : : }
87 : 0 : return "***ERROR***";
88 : : }
89 : :
90 : : /* Creates and returns a new reconnect FSM with default settings. The FSM is
91 : : * initially disabled. The caller will likely want to call reconnect_enable()
92 : : * and reconnect_set_name() on the returned object. */
93 : : struct reconnect *
94 : 15454 : reconnect_create(long long int now)
95 : : {
96 : 15454 : struct reconnect *fsm = xzalloc(sizeof *fsm);
97 : :
98 : 15454 : fsm->name = xstrdup("void");
99 : 15454 : fsm->min_backoff = RECONNECT_DEFAULT_MIN_BACKOFF;
100 : 15454 : fsm->max_backoff = RECONNECT_DEFAULT_MAX_BACKOFF;
101 : 15454 : fsm->probe_interval = RECONNECT_DEFAULT_PROBE_INTERVAL;
102 : 15454 : fsm->passive = false;
103 : 15454 : fsm->info = VLL_INFO;
104 : :
105 : 15454 : fsm->state = S_VOID;
106 : 15454 : fsm->state_entered = now;
107 : 15454 : fsm->backoff = 0;
108 : 15454 : fsm->last_activity = now;
109 : 15454 : fsm->last_connected = LLONG_MAX;
110 : 15454 : fsm->last_disconnected = LLONG_MAX;
111 : 15454 : fsm->max_tries = UINT_MAX;
112 : 15454 : fsm->creation_time = now;
113 : :
114 : 15454 : return fsm;
115 : : }
116 : :
117 : : /* Frees 'fsm'. */
118 : : void
119 : 15348 : reconnect_destroy(struct reconnect *fsm)
120 : : {
121 [ + - ]: 15348 : if (fsm) {
122 : 15348 : free(fsm->name);
123 : 15348 : free(fsm);
124 : : }
125 : 15348 : }
126 : :
127 : : /* If 'quiet' is true, 'fsm' will log informational messages at level VLL_DBG,
128 : : * by default keeping them out of log files. This is appropriate if the
129 : : * connection is one that is expected to be short-lived, so that the log
130 : : * messages are merely distracting.
131 : : *
132 : : * If 'quiet' is false, 'fsm' logs informational messages at level VLL_INFO.
133 : : * This is the default.
134 : : *
135 : : * This setting has no effect on the log level of debugging, warning, or error
136 : : * messages. */
137 : : void
138 : 8186 : reconnect_set_quiet(struct reconnect *fsm, bool quiet)
139 : : {
140 [ + - ]: 8186 : fsm->info = quiet ? VLL_DBG : VLL_INFO;
141 : 8186 : }
142 : :
143 : : /* Returns 'fsm''s name. */
144 : : const char *
145 : 7200 : reconnect_get_name(const struct reconnect *fsm)
146 : : {
147 : 7200 : return fsm->name;
148 : : }
149 : :
150 : : /* Sets 'fsm''s name to 'name'. If 'name' is null, then "void" is used
151 : : * instead.
152 : : *
153 : : * The name set for 'fsm' is used in log messages. */
154 : : void
155 : 15454 : reconnect_set_name(struct reconnect *fsm, const char *name)
156 : : {
157 : 15454 : free(fsm->name);
158 [ + - ]: 15454 : fsm->name = xstrdup(name ? name : "void");
159 : 15454 : }
160 : :
161 : : /* Return the minimum number of milliseconds to back off between consecutive
162 : : * connection attempts. The default is RECONNECT_DEFAULT_MIN_BACKOFF. */
163 : : int
164 : 0 : reconnect_get_min_backoff(const struct reconnect *fsm)
165 : : {
166 : 0 : return fsm->min_backoff;
167 : : }
168 : :
169 : : /* Return the maximum number of milliseconds to back off between consecutive
170 : : * connection attempts. The default is RECONNECT_DEFAULT_MAX_BACKOFF. */
171 : : int
172 : 0 : reconnect_get_max_backoff(const struct reconnect *fsm)
173 : : {
174 : 0 : return fsm->max_backoff;
175 : : }
176 : :
177 : : /* Returns the "probe interval" for 'fsm' in milliseconds. If this is zero, it
178 : : * disables the connection keepalive feature. If it is nonzero, then if the
179 : : * interval passes while 'fsm' is connected and without reconnect_activity()
180 : : * being called for 'fsm', reconnect_run() returns RECONNECT_PROBE. If the
181 : : * interval passes again without reconnect_activity() being called,
182 : : * reconnect_run() returns RECONNECT_DISCONNECT for 'fsm'. */
183 : : int
184 : 0 : reconnect_get_probe_interval(const struct reconnect *fsm)
185 : : {
186 : 0 : return fsm->probe_interval;
187 : : }
188 : :
189 : : /* Limits the maximum number of times that 'fsm' will ask the client to try to
190 : : * reconnect to 'max_tries'. UINT_MAX (the default) means an unlimited number
191 : : * of tries.
192 : : *
193 : : * After the number of tries has expired, the 'fsm' will disable itself
194 : : * instead of backing off and retrying. */
195 : : void
196 : 16690 : reconnect_set_max_tries(struct reconnect *fsm, unsigned int max_tries)
197 : : {
198 : 16690 : fsm->max_tries = max_tries;
199 : 16690 : }
200 : :
201 : : /* Returns the current remaining number of connection attempts, UINT_MAX if
202 : : * the number is unlimited. */
203 : : unsigned int
204 : 8444 : reconnect_get_max_tries(struct reconnect *fsm)
205 : : {
206 : 8444 : return fsm->max_tries;
207 : : }
208 : :
209 : : /* Configures the backoff parameters for 'fsm'. 'min_backoff' is the minimum
210 : : * number of milliseconds, and 'max_backoff' is the maximum, between connection
211 : : * attempts. The current backoff is also the duration that 'fsm' is willing to
212 : : * wait for a given connection to succeed or fail.
213 : : *
214 : : * 'min_backoff' must be at least 1000, and 'max_backoff' must be greater than
215 : : * or equal to 'min_backoff'.
216 : : *
217 : : * Pass 0 for 'min_backoff' or 'max_backoff' or both to use the defaults. */
218 : : void
219 : 95492 : reconnect_set_backoff(struct reconnect *fsm, int min_backoff, int max_backoff)
220 : : {
221 : 95492 : fsm->min_backoff = MAX(min_backoff, 1000);
222 : 95492 : fsm->max_backoff = (max_backoff
223 : : ? MAX(max_backoff, 1000)
224 [ + - ]: 95492 : : RECONNECT_DEFAULT_MAX_BACKOFF);
225 [ - + ]: 95492 : if (fsm->min_backoff > fsm->max_backoff) {
226 : 0 : fsm->max_backoff = fsm->min_backoff;
227 : : }
228 : :
229 [ + + ][ - + ]: 95492 : if (fsm->state == S_BACKOFF && fsm->backoff > max_backoff) {
230 : 0 : fsm->backoff = max_backoff;
231 : : }
232 : 95492 : }
233 : :
234 : : /* Sets the "probe interval" for 'fsm' to 'probe_interval', in milliseconds.
235 : : * If this is zero, it disables the connection keepalive feature. If it is
236 : : * nonzero, then if the interval passes while 'fsm' is connected and without
237 : : * reconnect_activity() being called for 'fsm', reconnect_run() returns
238 : : * RECONNECT_PROBE. If the interval passes again without reconnect_activity()
239 : : * being called, reconnect_run() returns RECONNECT_DISCONNECT for 'fsm'.
240 : : *
241 : : * If 'probe_interval' is nonzero, then it will be forced to a value of at
242 : : * least 1000 ms. */
243 : : void
244 : 97345 : reconnect_set_probe_interval(struct reconnect *fsm, int probe_interval)
245 : : {
246 [ + + ]: 97345 : fsm->probe_interval = probe_interval ? MAX(1000, probe_interval) : 0;
247 : 97345 : }
248 : :
249 : : /* Returns true if 'fsm' is in passive mode, false if 'fsm' is in active mode
250 : : * (the default). */
251 : : bool
252 : 7200 : reconnect_is_passive(const struct reconnect *fsm)
253 : : {
254 : 7200 : return fsm->passive;
255 : : }
256 : :
257 : : /* Configures 'fsm' for active or passive mode. In active mode (the default),
258 : : * the FSM is attempting to connect to a remote host. In passive mode, the FSM
259 : : * is listening for connections from a remote host. */
260 : : void
261 : 61 : reconnect_set_passive(struct reconnect *fsm, bool passive, long long int now)
262 : : {
263 [ + + ]: 61 : if (fsm->passive != passive) {
264 : 1 : fsm->passive = passive;
265 : :
266 [ + - ][ - + ]: 1 : if (passive
267 : 1 : ? fsm->state & (S_CONNECTING | S_RECONNECT)
268 [ # # ][ # # ]: 0 : : fsm->state == S_LISTENING && reconnect_may_retry(fsm)) {
269 : 0 : reconnect_transition__(fsm, now, S_BACKOFF);
270 : 0 : fsm->backoff = 0;
271 : : }
272 : : }
273 : 61 : }
274 : :
275 : : /* Returns true if 'fsm' has been enabled with reconnect_enable(). Calling
276 : : * another function that indicates a change in connection state, such as
277 : : * reconnect_disconnected() or reconnect_force_reconnect(), will also enable
278 : : * a reconnect FSM. */
279 : : bool
280 : 0 : reconnect_is_enabled(const struct reconnect *fsm)
281 : : {
282 : 0 : return fsm->state != S_VOID;
283 : : }
284 : :
285 : : /* If 'fsm' is disabled (the default for newly created FSMs), enables it, so
286 : : * that the next call to reconnect_run() for 'fsm' will return
287 : : * RECONNECT_CONNECT.
288 : : *
289 : : * If 'fsm' is not disabled, this function has no effect. */
290 : : void
291 : 7267 : reconnect_enable(struct reconnect *fsm, long long int now)
292 : : {
293 [ + - ][ + + ]: 7267 : if (fsm->state == S_VOID && reconnect_may_retry(fsm)) {
294 : 7266 : reconnect_transition__(fsm, now, S_BACKOFF);
295 : 7266 : fsm->backoff = 0;
296 : : }
297 : 7267 : }
298 : :
299 : : /* Disables 'fsm'. Until 'fsm' is enabled again, reconnect_run() will always
300 : : * return 0. */
301 : : void
302 : 0 : reconnect_disable(struct reconnect *fsm, long long int now)
303 : : {
304 [ # # ]: 0 : if (fsm->state != S_VOID) {
305 : 0 : reconnect_transition__(fsm, now, S_VOID);
306 : : }
307 : 0 : }
308 : :
309 : : /* If 'fsm' is enabled and currently connected (or attempting to connect),
310 : : * forces reconnect_run() for 'fsm' to return RECONNECT_DISCONNECT the next
311 : : * time it is called, which should cause the client to drop the connection (or
312 : : * attempt), back off, and then reconnect. */
313 : : void
314 : 4 : reconnect_force_reconnect(struct reconnect *fsm, long long int now)
315 : : {
316 [ + - ]: 4 : if (fsm->state & (S_CONNECTING | S_ACTIVE | S_IDLE)) {
317 : 4 : reconnect_transition__(fsm, now, S_RECONNECT);
318 : : }
319 : 4 : }
320 : :
321 : : /* Tell 'fsm' that the connection dropped or that a connection attempt failed.
322 : : * 'error' specifies the reason: a positive value represents an errno value,
323 : : * EOF indicates that the connection was closed by the peer (e.g. read()
324 : : * returned 0), and 0 indicates no specific error.
325 : : *
326 : : * The FSM will back off, then reconnect. */
327 : : void
328 : 8197 : reconnect_disconnected(struct reconnect *fsm, long long int now, int error)
329 : : {
330 [ + - ]: 8197 : if (!(fsm->state & (S_BACKOFF | S_VOID))) {
331 : : /* Report what happened. */
332 [ + + ]: 8197 : if (fsm->state & (S_ACTIVE | S_IDLE)) {
333 [ + + ]: 8166 : if (error > 0) {
334 [ + - ]: 58 : VLOG_WARN("%s: connection dropped (%s)",
335 : : fsm->name, ovs_strerror(error));
336 [ + + ]: 8108 : } else if (error == EOF) {
337 [ + + ]: 8098 : VLOG(fsm->info, "%s: connection closed by peer", fsm->name);
338 : : } else {
339 [ - + ]: 8166 : VLOG(fsm->info, "%s: connection dropped", fsm->name);
340 : : }
341 [ + + ]: 31 : } else if (fsm->state == S_LISTENING) {
342 [ - + ]: 1 : if (error > 0) {
343 [ # # ]: 0 : VLOG_WARN("%s: error listening for connections (%s)",
344 : : fsm->name, ovs_strerror(error));
345 : : } else {
346 [ - + ]: 1 : VLOG(fsm->info, "%s: error listening for connections",
347 : : fsm->name);
348 : : }
349 : : } else {
350 [ - + ]: 30 : const char *type = fsm->passive ? "listen" : "connection";
351 [ + + ]: 30 : if (error > 0) {
352 [ + + ]: 14 : VLOG_INFO("%s: %s attempt failed (%s)",
353 : : fsm->name, type, ovs_strerror(error));
354 : : } else {
355 [ + + ]: 16 : VLOG(fsm->info, "%s: %s attempt timed out", fsm->name, type);
356 : : }
357 : : }
358 : :
359 [ + + ]: 8197 : if (fsm->state & (S_ACTIVE | S_IDLE)) {
360 : 8166 : fsm->last_disconnected = now;
361 : : }
362 : : /* Back off. */
363 [ + + ]: 8197 : if (fsm->state & (S_ACTIVE | S_IDLE)
364 [ + + ]: 8166 : && (fsm->last_activity - fsm->last_connected >= fsm->backoff
365 [ - + ]: 6 : || fsm->passive)) {
366 [ + + ]: 8160 : fsm->backoff = fsm->passive ? 0 : fsm->min_backoff;
367 : : } else {
368 [ + + ]: 37 : if (fsm->backoff < fsm->min_backoff) {
369 : 18 : fsm->backoff = fsm->min_backoff;
370 [ + + ]: 19 : } else if (fsm->backoff >= fsm->max_backoff / 2) {
371 : 4 : fsm->backoff = fsm->max_backoff;
372 : : } else {
373 : 15 : fsm->backoff *= 2;
374 : : }
375 [ + + ]: 37 : if (fsm->passive) {
376 [ - + ]: 1 : VLOG(fsm->info, "%s: waiting %.3g seconds before trying to "
377 : : "listen again", fsm->name, fsm->backoff / 1000.0);
378 : : } else {
379 [ + + ]: 36 : VLOG(fsm->info, "%s: waiting %.3g seconds before reconnect",
380 : : fsm->name, fsm->backoff / 1000.0);
381 : : }
382 : : }
383 : :
384 [ + + ]: 8197 : reconnect_transition__(fsm, now,
385 : 8197 : reconnect_may_retry(fsm) ? S_BACKOFF : S_VOID);
386 : : }
387 : 8197 : }
388 : :
389 : : /* Tell 'fsm' that a connection or listening attempt is in progress.
390 : : *
391 : : * The FSM will start a timer, after which the connection or listening attempt
392 : : * will be aborted (by returning RECONNECT_DISCONNECT from
393 : : * reconnect_run()). */
394 : : void
395 : 22677 : reconnect_connecting(struct reconnect *fsm, long long int now)
396 : : {
397 [ + + ]: 22677 : if (fsm->state != S_CONNECTING) {
398 [ + + ]: 15470 : if (fsm->passive) {
399 [ - + ]: 1 : VLOG(fsm->info, "%s: listening...", fsm->name);
400 : : } else {
401 [ + + ]: 15469 : VLOG(fsm->info, "%s: connecting...", fsm->name);
402 : : }
403 : 15470 : reconnect_transition__(fsm, now, S_CONNECTING);
404 : : }
405 : 22677 : }
406 : :
407 : : /* Tell 'fsm' that the client is listening for connection attempts. This state
408 : : * last indefinitely until the client reports some change.
409 : : *
410 : : * The natural progression from this state is for the client to report that a
411 : : * connection has been accepted or is in progress of being accepted, by calling
412 : : * reconnect_connecting() or reconnect_connected().
413 : : *
414 : : * The client may also report that listening failed (e.g. accept() returned an
415 : : * unexpected error such as ENOMEM) by calling reconnect_listen_error(), in
416 : : * which case the FSM will back off and eventually return RECONNECT_CONNECT
417 : : * from reconnect_run() to tell the client to try listening again. */
418 : : void
419 : 3 : reconnect_listening(struct reconnect *fsm, long long int now)
420 : : {
421 [ + - ]: 3 : if (fsm->state != S_LISTENING) {
422 [ - + ]: 3 : VLOG(fsm->info, "%s: listening...", fsm->name);
423 : 3 : reconnect_transition__(fsm, now, S_LISTENING);
424 : : }
425 : 3 : }
426 : :
427 : : /* Tell 'fsm' that the client's attempt to accept a connection failed
428 : : * (e.g. accept() returned an unexpected error such as ENOMEM).
429 : : *
430 : : * If the FSM is currently listening (reconnect_listening() was called), it
431 : : * will back off and eventually return RECONNECT_CONNECT from reconnect_run()
432 : : * to tell the client to try listening again. If there is an active
433 : : * connection, this will be delayed until that connection drops. */
434 : : void
435 : 1 : reconnect_listen_error(struct reconnect *fsm, long long int now, int error)
436 : : {
437 [ + - ]: 1 : if (fsm->state == S_LISTENING) {
438 : 1 : reconnect_disconnected(fsm, now, error);
439 : : }
440 : 1 : }
441 : :
442 : : /* Tell 'fsm' that the connection was successful.
443 : : *
444 : : * The FSM will start the probe interval timer, which is reset by
445 : : * reconnect_activity(). If the timer expires, a probe will be sent (by
446 : : * returning RECONNECT_PROBE from reconnect_run()). If the timer expires
447 : : * again without being reset, the connection will be aborted (by returning
448 : : * RECONNECT_DISCONNECT from reconnect_run()). */
449 : : void
450 : 15444 : reconnect_connected(struct reconnect *fsm, long long int now)
451 : : {
452 [ + - ]: 15444 : if (!is_connected_state(fsm->state)) {
453 : 15444 : reconnect_connecting(fsm, now);
454 : :
455 [ + + ]: 15444 : VLOG(fsm->info, "%s: connected", fsm->name);
456 : 15444 : reconnect_transition__(fsm, now, S_ACTIVE);
457 : 15444 : fsm->last_connected = now;
458 : : }
459 : 15444 : }
460 : :
461 : : /* Tell 'fsm' that the connection attempt failed.
462 : : *
463 : : * The FSM will back off and attempt to reconnect. */
464 : : void
465 : 26 : reconnect_connect_failed(struct reconnect *fsm, long long int now, int error)
466 : : {
467 : 26 : reconnect_connecting(fsm, now);
468 : 26 : reconnect_disconnected(fsm, now, error);
469 : 26 : }
470 : :
471 : : /* Tell 'fsm' that some activity has occurred on the connection. This resets
472 : : * the probe interval timer, so that the connection is known not to be idle. */
473 : : void
474 : 60833 : reconnect_activity(struct reconnect *fsm, long long int now)
475 : : {
476 [ + + ]: 60833 : if (fsm->state != S_ACTIVE) {
477 : 103 : reconnect_transition__(fsm, now, S_ACTIVE);
478 : : }
479 : 60833 : fsm->last_activity = now;
480 : 60833 : }
481 : :
482 : : static void
483 : 46597 : reconnect_transition__(struct reconnect *fsm, long long int now,
484 : : enum state state)
485 : : {
486 [ + + ]: 46597 : if (fsm->state == S_CONNECTING) {
487 : 15470 : fsm->n_attempted_connections++;
488 [ + + ]: 15470 : if (state == S_ACTIVE) {
489 : 15444 : fsm->n_successful_connections++;
490 : : }
491 : : }
492 [ + + ]: 46597 : if (is_connected_state(fsm->state) != is_connected_state(state)) {
493 [ + + ]: 23614 : if (is_connected_state(fsm->state)) {
494 : 8170 : fsm->total_connected_duration += now - fsm->last_connected;
495 : : }
496 : 23614 : fsm->seqno++;
497 : : }
498 : :
499 [ - + ]: 46597 : VLOG_DBG("%s: entering %s", fsm->name, reconnect_state_name__(state));
500 : 46597 : fsm->state = state;
501 : 46597 : fsm->state_entered = now;
502 : 46597 : }
503 : :
504 : : static long long int
505 : 501366 : reconnect_deadline__(const struct reconnect *fsm)
506 : : {
507 [ - + ]: 501366 : ovs_assert(fsm->state_entered != LLONG_MIN);
508 [ + + + + : 501366 : switch (fsm->state) {
+ + - ]
509 : : case S_VOID:
510 : : case S_LISTENING:
511 : 8059 : return LLONG_MAX;
512 : :
513 : : case S_BACKOFF:
514 : 7915 : return fsm->state_entered + fsm->backoff;
515 : :
516 : : case S_CONNECTING:
517 : 7229 : return fsm->state_entered + MAX(1000, fsm->backoff);
518 : :
519 : : case S_ACTIVE:
520 [ + + ]: 477947 : if (fsm->probe_interval) {
521 : 26106 : long long int base = MAX(fsm->last_activity, fsm->state_entered);
522 : 26106 : return base + fsm->probe_interval;
523 : : }
524 : 451841 : return LLONG_MAX;
525 : :
526 : : case S_IDLE:
527 [ + - ]: 212 : if (fsm->probe_interval) {
528 : 212 : return fsm->state_entered + fsm->probe_interval;
529 : : }
530 : 0 : return LLONG_MAX;
531 : :
532 : : case S_RECONNECT:
533 : 4 : return fsm->state_entered;
534 : : }
535 : :
536 : 0 : OVS_NOT_REACHED();
537 : : }
538 : :
539 : : /* Assesses whether any action should be taken on 'fsm'. The return value is
540 : : * one of:
541 : : *
542 : : * - 0: The client need not take any action.
543 : : *
544 : : * - Active client, RECONNECT_CONNECT: The client should start a connection
545 : : * attempt and indicate this by calling reconnect_connecting(). If the
546 : : * connection attempt has definitely succeeded, it should call
547 : : * reconnect_connected(). If the connection attempt has definitely
548 : : * failed, it should call reconnect_connect_failed().
549 : : *
550 : : * The FSM is smart enough to back off correctly after successful
551 : : * connections that quickly abort, so it is OK to call
552 : : * reconnect_connected() after a low-level successful connection
553 : : * (e.g. connect()) even if the connection might soon abort due to a
554 : : * failure at a high-level (e.g. SSL negotiation failure).
555 : : *
556 : : * - Passive client, RECONNECT_CONNECT: The client should try to listen for
557 : : * a connection, if it is not already listening. It should call
558 : : * reconnect_listening() if successful, otherwise reconnect_connecting()
559 : : * or reconnected_connect_failed() if the attempt is in progress or
560 : : * definitely failed, respectively.
561 : : *
562 : : * A listening passive client should constantly attempt to accept a new
563 : : * connection and report an accepted connection with
564 : : * reconnect_connected().
565 : : *
566 : : * - RECONNECT_DISCONNECT: The client should abort the current connection
567 : : * or connection attempt or listen attempt and call
568 : : * reconnect_disconnected() or reconnect_connect_failed() to indicate it.
569 : : *
570 : : * - RECONNECT_PROBE: The client should send some kind of request to the
571 : : * peer that will elicit a response, to ensure that the connection is
572 : : * indeed in working order. (This will only be returned if the "probe
573 : : * interval" is nonzero--see reconnect_set_probe_interval()).
574 : : */
575 : : enum reconnect_action
576 : 277677 : reconnect_run(struct reconnect *fsm, long long int now)
577 : : {
578 [ + + ]: 277677 : if (now >= reconnect_deadline__(fsm)) {
579 [ - + + + : 7364 : switch (fsm->state) {
+ + - - ]
580 : : case S_VOID:
581 : 0 : return 0;
582 : :
583 : : case S_BACKOFF:
584 : 7231 : return RECONNECT_CONNECT;
585 : :
586 : : case S_CONNECTING:
587 : 12 : return RECONNECT_DISCONNECT;
588 : :
589 : : case S_ACTIVE:
590 [ - + ]: 110 : VLOG_DBG("%s: idle %lld ms, sending inactivity probe", fsm->name,
591 : : now - MAX(fsm->last_activity, fsm->state_entered));
592 : 110 : reconnect_transition__(fsm, now, S_IDLE);
593 : 110 : return RECONNECT_PROBE;
594 : :
595 : : case S_IDLE:
596 [ - + ]: 7 : VLOG_ERR("%s: no response to inactivity probe after %.3g "
597 : : "seconds, disconnecting",
598 : : fsm->name, (now - fsm->state_entered) / 1000.0);
599 : 7 : return RECONNECT_DISCONNECT;
600 : :
601 : : case S_RECONNECT:
602 : 4 : return RECONNECT_DISCONNECT;
603 : :
604 : : case S_LISTENING:
605 : 0 : return 0;
606 : : }
607 : :
608 : 0 : OVS_NOT_REACHED();
609 : : } else {
610 : 270313 : return 0;
611 : : }
612 : : }
613 : :
614 : : /* Causes the next call to poll_block() to wake up when reconnect_run() should
615 : : * be called on 'fsm'. */
616 : : void
617 : 223638 : reconnect_wait(struct reconnect *fsm, long long int now)
618 : : {
619 : 223638 : int timeout = reconnect_timeout(fsm, now);
620 [ + + ]: 223638 : if (timeout >= 0) {
621 : 20686 : poll_timer_wait(timeout);
622 : : }
623 : 223638 : }
624 : :
625 : : /* Returns the number of milliseconds after which reconnect_run() should be
626 : : * called on 'fsm' if nothing else notable happens in the meantime, or a
627 : : * negative number if this is currently unnecessary. */
628 : : int
629 : 223689 : reconnect_timeout(struct reconnect *fsm, long long int now)
630 : : {
631 : 223689 : long long int deadline = reconnect_deadline__(fsm);
632 [ + + ]: 223689 : if (deadline != LLONG_MAX) {
633 : 20734 : long long int remaining = deadline - now;
634 [ + + ][ + + ]: 20734 : return MAX(0, MIN(INT_MAX, remaining));
635 : : }
636 : 202955 : return -1;
637 : : }
638 : :
639 : : /* Returns true if 'fsm' is currently believed to be connected, that is, if
640 : : * reconnect_connected() was called more recently than any call to
641 : : * reconnect_connect_failed() or reconnect_disconnected() or
642 : : * reconnect_disable(), and false otherwise. */
643 : : bool
644 : 70443 : reconnect_is_connected(const struct reconnect *fsm)
645 : : {
646 : 70443 : return is_connected_state(fsm->state);
647 : : }
648 : :
649 : : /* Returns the number of milliseconds since 'fsm' last successfully connected
650 : : * to its peer (even if it has since disconnected). Returns UINT_MAX if never
651 : : * connected. */
652 : : unsigned int
653 : 362 : reconnect_get_last_connect_elapsed(const struct reconnect *fsm,
654 : : long long int now)
655 : : {
656 [ + + ]: 362 : return fsm->last_connected == LLONG_MAX ? UINT_MAX
657 : 182 : : now - fsm->last_connected;
658 : : }
659 : :
660 : : /* Returns the number of milliseconds since 'fsm' last disconnected
661 : : * from its peer (even if it has since reconnected). Returns UINT_MAX if never
662 : : * disconnected. */
663 : : unsigned int
664 : 290 : reconnect_get_last_disconnect_elapsed(const struct reconnect *fsm,
665 : : long long int now)
666 : : {
667 [ + + ]: 290 : return fsm->last_disconnected == LLONG_MAX ? UINT_MAX
668 : 48 : : now - fsm->last_disconnected;
669 : : }
670 : :
671 : : /* Copies various statistics for 'fsm' into '*stats'. */
672 : : void
673 : 290 : reconnect_get_stats(const struct reconnect *fsm, long long int now,
674 : : struct reconnect_stats *stats)
675 : : {
676 : 290 : stats->creation_time = fsm->creation_time;
677 : 290 : stats->last_activity = fsm->last_activity;
678 : 290 : stats->last_connected = fsm->last_connected;
679 : 290 : stats->last_disconnected = fsm->last_disconnected;
680 : 290 : stats->backoff = fsm->backoff;
681 : 290 : stats->seqno = fsm->seqno;
682 : 290 : stats->is_connected = reconnect_is_connected(fsm);
683 : : stats->msec_since_connect
684 : 290 : = reconnect_get_last_connect_elapsed(fsm, now);
685 : : stats->msec_since_disconnect
686 : 290 : = reconnect_get_last_disconnect_elapsed(fsm, now);
687 : 580 : stats->total_connected_duration = fsm->total_connected_duration
688 : 290 : + (is_connected_state(fsm->state)
689 [ + + ]: 290 : ? reconnect_get_last_connect_elapsed(fsm, now) : 0);
690 : 290 : stats->n_attempted_connections = fsm->n_attempted_connections;
691 : 290 : stats->n_successful_connections = fsm->n_successful_connections;
692 : 290 : stats->state = reconnect_state_name__(fsm->state);
693 : 290 : stats->state_elapsed = now - fsm->state_entered;
694 : 290 : }
695 : :
696 : : static bool
697 : 15464 : reconnect_may_retry(struct reconnect *fsm)
698 : : {
699 : 15464 : bool may_retry = fsm->max_tries > 0;
700 [ + + ][ + + ]: 15464 : if (may_retry && fsm->max_tries != UINT_MAX) {
701 : 6 : fsm->max_tries--;
702 : : }
703 : 15464 : return may_retry;
704 : : }
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