ofproto: Resubmit Statistics.
[openvswitch] / ovsdb / jsonrpc-server.c
1 /* Copyright (c) 2009, 2010 Nicira Networks
2  *
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at:
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15
16 #include <config.h>
17
18 #include "jsonrpc-server.h"
19
20 #include <assert.h>
21 #include <errno.h>
22
23 #include "bitmap.h"
24 #include "column.h"
25 #include "json.h"
26 #include "jsonrpc.h"
27 #include "ovsdb-error.h"
28 #include "ovsdb-parser.h"
29 #include "ovsdb.h"
30 #include "reconnect.h"
31 #include "row.h"
32 #include "stream.h"
33 #include "table.h"
34 #include "timeval.h"
35 #include "transaction.h"
36 #include "trigger.h"
37 #include "vlog.h"
38
39 VLOG_DEFINE_THIS_MODULE(ovsdb_jsonrpc_server);
40
41 struct ovsdb_jsonrpc_remote;
42 struct ovsdb_jsonrpc_session;
43
44 /* Message rate-limiting. */
45 struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
46
47 /* Sessions. */
48 static struct ovsdb_jsonrpc_session *ovsdb_jsonrpc_session_create(
49     struct ovsdb_jsonrpc_remote *, struct jsonrpc_session *);
50 static void ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *);
51 static void ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *);
52 static void ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *);
53 static void ovsdb_jsonrpc_session_reconnect_all(struct ovsdb_jsonrpc_remote *);
54 static void ovsdb_jsonrpc_session_set_all_options(
55     struct ovsdb_jsonrpc_remote *, const struct ovsdb_jsonrpc_options *);
56 static void ovsdb_jsonrpc_session_get_status(
57     const struct ovsdb_jsonrpc_remote *,
58     struct shash *);
59
60 /* Triggers. */
61 static void ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *,
62                                          struct json *id, struct json *params);
63 static struct ovsdb_jsonrpc_trigger *ovsdb_jsonrpc_trigger_find(
64     struct ovsdb_jsonrpc_session *, const struct json *id, size_t hash);
65 static void ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *);
66 static void ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *);
67 static void ovsdb_jsonrpc_trigger_complete_done(
68     struct ovsdb_jsonrpc_session *);
69
70 /* Monitors. */
71 static struct json *ovsdb_jsonrpc_monitor_create(
72     struct ovsdb_jsonrpc_session *, struct json *params);
73 static struct jsonrpc_msg *ovsdb_jsonrpc_monitor_cancel(
74     struct ovsdb_jsonrpc_session *,
75     struct json_array *params,
76     const struct json *request_id);
77 static void ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *);
78 \f
79 /* JSON-RPC database server. */
80
81 struct ovsdb_jsonrpc_server {
82     struct ovsdb *db;
83     unsigned int n_sessions, max_sessions;
84     struct shash remotes;      /* Contains "struct ovsdb_jsonrpc_remote *"s. */
85 };
86
87 /* A configured remote.  This is either a passive stream listener plus a list
88  * of the currently connected sessions, or a list of exactly one active
89  * session. */
90 struct ovsdb_jsonrpc_remote {
91     struct ovsdb_jsonrpc_server *server;
92     struct pstream *listener;   /* Listener, if passive. */
93     struct list sessions;       /* List of "struct ovsdb_jsonrpc_session"s. */
94 };
95
96 static struct ovsdb_jsonrpc_remote *ovsdb_jsonrpc_server_add_remote(
97     struct ovsdb_jsonrpc_server *, const char *name);
98 static void ovsdb_jsonrpc_server_del_remote(struct shash_node *);
99
100 struct ovsdb_jsonrpc_server *
101 ovsdb_jsonrpc_server_create(struct ovsdb *db)
102 {
103     struct ovsdb_jsonrpc_server *server = xzalloc(sizeof *server);
104     server->db = db;
105     server->max_sessions = 64;
106     shash_init(&server->remotes);
107     return server;
108 }
109
110 void
111 ovsdb_jsonrpc_server_destroy(struct ovsdb_jsonrpc_server *svr)
112 {
113     struct shash_node *node, *next;
114
115     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
116         ovsdb_jsonrpc_server_del_remote(node);
117     }
118     shash_destroy(&svr->remotes);
119     free(svr);
120 }
121
122 struct ovsdb_jsonrpc_options *
123 ovsdb_jsonrpc_default_options(void)
124 {
125     struct ovsdb_jsonrpc_options *options = xzalloc(sizeof *options);
126     options->probe_interval = RECONNECT_DEFAULT_PROBE_INTERVAL;
127     options->max_backoff = RECONNECT_DEFAULT_MAX_BACKOFF;
128     return options;
129 }
130
131 /* Sets 'svr''s current set of remotes to the names in 'new_remotes', with
132  * options in the struct ovsdb_jsonrpc_options supplied as the data values.
133  *
134  * A remote is an active or passive stream connection method, e.g. "pssl:" or
135  * "tcp:1.2.3.4". */
136 void
137 ovsdb_jsonrpc_server_set_remotes(struct ovsdb_jsonrpc_server *svr,
138                                  const struct shash *new_remotes)
139 {
140     struct shash_node *node, *next;
141
142     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
143         if (!shash_find(new_remotes, node->name)) {
144             ovsdb_jsonrpc_server_del_remote(node);
145         }
146     }
147     SHASH_FOR_EACH (node, new_remotes) {
148         const struct ovsdb_jsonrpc_options *options = node->data;
149         struct ovsdb_jsonrpc_remote *remote;
150
151         remote = shash_find_data(&svr->remotes, node->name);
152         if (!remote) {
153             remote = ovsdb_jsonrpc_server_add_remote(svr, node->name);
154             if (!remote) {
155                 continue;
156             }
157         }
158
159         ovsdb_jsonrpc_session_set_all_options(remote, options);
160     }
161 }
162
163 static struct ovsdb_jsonrpc_remote *
164 ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *svr,
165                                 const char *name)
166 {
167     struct ovsdb_jsonrpc_remote *remote;
168     struct pstream *listener;
169     int error;
170
171     error = jsonrpc_pstream_open(name, &listener);
172     if (error && error != EAFNOSUPPORT) {
173         VLOG_ERR_RL(&rl, "%s: listen failed: %s", name, strerror(error));
174         return NULL;
175     }
176
177     remote = xmalloc(sizeof *remote);
178     remote->server = svr;
179     remote->listener = listener;
180     list_init(&remote->sessions);
181     shash_add(&svr->remotes, name, remote);
182
183     if (!listener) {
184         ovsdb_jsonrpc_session_create(remote, jsonrpc_session_open(name));
185     }
186     return remote;
187 }
188
189 static void
190 ovsdb_jsonrpc_server_del_remote(struct shash_node *node)
191 {
192     struct ovsdb_jsonrpc_remote *remote = node->data;
193
194     ovsdb_jsonrpc_session_close_all(remote);
195     pstream_close(remote->listener);
196     shash_delete(&remote->server->remotes, node);
197     free(remote);
198 }
199
200 void
201 ovsdb_jsonrpc_server_get_remote_status(const struct ovsdb_jsonrpc_server *svr,
202                                        struct shash *statuses)
203 {
204     struct shash_node *node;
205
206     shash_init(statuses);
207
208     SHASH_FOR_EACH (node, &svr->remotes) {
209         const struct ovsdb_jsonrpc_remote *remote = node->data;
210
211         ovsdb_jsonrpc_session_get_status(remote, statuses);
212     }
213 }
214
215 /* Forces all of the JSON-RPC sessions managed by 'svr' to disconnect and
216  * reconnect. */
217 void
218 ovsdb_jsonrpc_server_reconnect(struct ovsdb_jsonrpc_server *svr)
219 {
220     struct shash_node *node;
221
222     SHASH_FOR_EACH (node, &svr->remotes) {
223         struct ovsdb_jsonrpc_remote *remote = node->data;
224
225         ovsdb_jsonrpc_session_reconnect_all(remote);
226     }
227 }
228
229 void
230 ovsdb_jsonrpc_server_run(struct ovsdb_jsonrpc_server *svr)
231 {
232     struct shash_node *node;
233
234     SHASH_FOR_EACH (node, &svr->remotes) {
235         struct ovsdb_jsonrpc_remote *remote = node->data;
236
237         if (remote->listener && svr->n_sessions < svr->max_sessions) {
238             struct stream *stream;
239             int error;
240
241             error = pstream_accept(remote->listener, &stream);
242             if (!error) {
243                 struct jsonrpc_session *js;
244                 js = jsonrpc_session_open_unreliably(jsonrpc_open(stream));
245                 ovsdb_jsonrpc_session_create(remote, js);
246             } else if (error != EAGAIN) {
247                 VLOG_WARN_RL(&rl, "%s: accept failed: %s",
248                              pstream_get_name(remote->listener),
249                              strerror(error));
250             }
251         }
252
253         ovsdb_jsonrpc_session_run_all(remote);
254     }
255 }
256
257 void
258 ovsdb_jsonrpc_server_wait(struct ovsdb_jsonrpc_server *svr)
259 {
260     struct shash_node *node;
261
262     SHASH_FOR_EACH (node, &svr->remotes) {
263         struct ovsdb_jsonrpc_remote *remote = node->data;
264
265         if (remote->listener && svr->n_sessions < svr->max_sessions) {
266             pstream_wait(remote->listener);
267         }
268
269         ovsdb_jsonrpc_session_wait_all(remote);
270     }
271 }
272 \f
273 /* JSON-RPC database server session. */
274
275 struct ovsdb_jsonrpc_session {
276     struct ovsdb_jsonrpc_remote *remote;
277     struct list node;           /* Element in remote's sessions list. */
278
279     /* Triggers. */
280     struct hmap triggers;       /* Hmap of "struct ovsdb_jsonrpc_trigger"s. */
281     struct list completions;    /* Completed triggers. */
282
283     /* Monitors. */
284     struct hmap monitors;       /* Hmap of "struct ovsdb_jsonrpc_monitor"s. */
285
286     /* Network connectivity. */
287     struct jsonrpc_session *js;  /* JSON-RPC session. */
288     unsigned int js_seqno;       /* Last jsonrpc_session_get_seqno() value. */
289 };
290
291 static void ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *);
292 static int ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *);
293 static void ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *);
294 static void ovsdb_jsonrpc_session_set_options(
295     struct ovsdb_jsonrpc_session *, const struct ovsdb_jsonrpc_options *);
296 static void ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *,
297                                              struct jsonrpc_msg *);
298 static void ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *,
299                                              struct jsonrpc_msg *);
300
301 static struct ovsdb_jsonrpc_session *
302 ovsdb_jsonrpc_session_create(struct ovsdb_jsonrpc_remote *remote,
303                              struct jsonrpc_session *js)
304 {
305     struct ovsdb_jsonrpc_session *s;
306
307     s = xzalloc(sizeof *s);
308     s->remote = remote;
309     list_push_back(&remote->sessions, &s->node);
310     hmap_init(&s->triggers);
311     hmap_init(&s->monitors);
312     list_init(&s->completions);
313     s->js = js;
314     s->js_seqno = jsonrpc_session_get_seqno(js);
315
316     remote->server->n_sessions++;
317
318     return s;
319 }
320
321 static void
322 ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *s)
323 {
324     ovsdb_jsonrpc_monitor_remove_all(s);
325     jsonrpc_session_close(s->js);
326     list_remove(&s->node);
327     s->remote->server->n_sessions--;
328     free(s);
329 }
330
331 static int
332 ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *s)
333 {
334     jsonrpc_session_run(s->js);
335     if (s->js_seqno != jsonrpc_session_get_seqno(s->js)) {
336         s->js_seqno = jsonrpc_session_get_seqno(s->js);
337         ovsdb_jsonrpc_trigger_complete_all(s);
338         ovsdb_jsonrpc_monitor_remove_all(s);
339     }
340
341     ovsdb_jsonrpc_trigger_complete_done(s);
342
343     if (!jsonrpc_session_get_backlog(s->js)) {
344         struct jsonrpc_msg *msg = jsonrpc_session_recv(s->js);
345         if (msg) {
346             if (msg->type == JSONRPC_REQUEST) {
347                 ovsdb_jsonrpc_session_got_request(s, msg);
348             } else if (msg->type == JSONRPC_NOTIFY) {
349                 ovsdb_jsonrpc_session_got_notify(s, msg);
350             } else {
351                 VLOG_WARN("%s: received unexpected %s message",
352                           jsonrpc_session_get_name(s->js),
353                           jsonrpc_msg_type_to_string(msg->type));
354                 jsonrpc_session_force_reconnect(s->js);
355                 jsonrpc_msg_destroy(msg);
356             }
357         }
358     }
359     return jsonrpc_session_is_alive(s->js) ? 0 : ETIMEDOUT;
360 }
361
362 static void
363 ovsdb_jsonrpc_session_set_options(struct ovsdb_jsonrpc_session *session,
364                                   const struct ovsdb_jsonrpc_options *options)
365 {
366     jsonrpc_session_set_max_backoff(session->js, options->max_backoff);
367     jsonrpc_session_set_probe_interval(session->js, options->probe_interval);
368 }
369
370 static void
371 ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *remote)
372 {
373     struct ovsdb_jsonrpc_session *s, *next;
374
375     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
376         int error = ovsdb_jsonrpc_session_run(s);
377         if (error) {
378             ovsdb_jsonrpc_session_close(s);
379         }
380     }
381 }
382
383 static void
384 ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *s)
385 {
386     jsonrpc_session_wait(s->js);
387     if (!jsonrpc_session_get_backlog(s->js)) {
388         jsonrpc_session_recv_wait(s->js);
389     }
390 }
391
392 static void
393 ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *remote)
394 {
395     struct ovsdb_jsonrpc_session *s;
396
397     LIST_FOR_EACH (s, node, &remote->sessions) {
398         ovsdb_jsonrpc_session_wait(s);
399     }
400 }
401
402 static void
403 ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *remote)
404 {
405     struct ovsdb_jsonrpc_session *s, *next;
406
407     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
408         ovsdb_jsonrpc_session_close(s);
409     }
410 }
411
412 /* Forces all of the JSON-RPC sessions managed by 'remote' to disconnect and
413  * reconnect. */
414 static void
415 ovsdb_jsonrpc_session_reconnect_all(struct ovsdb_jsonrpc_remote *remote)
416 {
417     struct ovsdb_jsonrpc_session *s, *next;
418
419     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
420         jsonrpc_session_force_reconnect(s->js);
421         if (!jsonrpc_session_is_alive(s->js)) {
422             ovsdb_jsonrpc_session_close(s);
423         }
424     }
425 }
426
427 /* Sets the options for all of the JSON-RPC sessions managed by 'remote' to
428  * 'options'. */
429 static void
430 ovsdb_jsonrpc_session_set_all_options(
431     struct ovsdb_jsonrpc_remote *remote,
432     const struct ovsdb_jsonrpc_options *options)
433 {
434     struct ovsdb_jsonrpc_session *s;
435
436     LIST_FOR_EACH (s, node, &remote->sessions) {
437         ovsdb_jsonrpc_session_set_options(s, options);
438     }
439 }
440
441 static void
442 ovsdb_jsonrpc_session_get_status(const struct ovsdb_jsonrpc_remote *remote,
443                                  struct shash *shash)
444 {
445     const struct ovsdb_jsonrpc_session *s;
446     const struct jsonrpc_session *js;
447     const char *name;
448     struct ovsdb_jsonrpc_remote_status *status;
449     struct reconnect_stats rstats;
450
451     /* We only look at the first session in the list. There should be only one
452      * node in the list for outbound connections. We don't track status for
453      * each individual inbound connection if someone configures the DB that
454      * way. Since outbound connections are the norm, this is fine. */
455     if (list_is_empty(&remote->sessions)) {
456         return;
457     }
458     s = CONTAINER_OF(remote->sessions.next, struct ovsdb_jsonrpc_session, node);
459     js = s->js;
460     if (!js) {
461         return;
462     }
463     name = jsonrpc_session_get_name(js);
464
465     status = xzalloc(sizeof *status);
466     shash_add(shash, name, status);
467
468     status->is_connected = jsonrpc_session_is_connected(js);
469     status->last_error = jsonrpc_session_get_status(js);
470
471     jsonrpc_session_get_reconnect_stats(js, &rstats);
472     status->state = rstats.state;
473     status->state_elapsed = rstats.state_elapsed;
474
475     return;
476 }
477
478 static const char *
479 get_db_name(const struct ovsdb_jsonrpc_session *s)
480 {
481     return s->remote->server->db->schema->name;
482 }
483
484 static struct jsonrpc_msg *
485 ovsdb_jsonrpc_check_db_name(const struct ovsdb_jsonrpc_session *s,
486                             const struct jsonrpc_msg *request)
487 {
488     struct json_array *params;
489     const char *want_db_name;
490     const char *have_db_name;
491     struct ovsdb_error *error;
492     struct jsonrpc_msg *reply;
493
494     params = json_array(request->params);
495     if (!params->n || params->elems[0]->type != JSON_STRING) {
496         error = ovsdb_syntax_error(
497             request->params, NULL,
498             "%s request params must begin with <db-name>", request->method);
499         goto error;
500     }
501
502     want_db_name = params->elems[0]->u.string;
503     have_db_name = get_db_name(s);
504     if (strcmp(want_db_name, have_db_name)) {
505         error = ovsdb_syntax_error(
506             request->params, "unknown database",
507             "%s request specifies unknown database %s",
508             request->method, want_db_name);
509         goto error;
510     }
511
512     return NULL;
513
514 error:
515     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
516     ovsdb_error_destroy(error);
517     return reply;
518 }
519
520 static struct jsonrpc_msg *
521 execute_transaction(struct ovsdb_jsonrpc_session *s,
522                     struct jsonrpc_msg *request)
523 {
524     ovsdb_jsonrpc_trigger_create(s, request->id, request->params);
525     request->id = NULL;
526     request->params = NULL;
527     jsonrpc_msg_destroy(request);
528     return NULL;
529 }
530
531 static void
532 ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *s,
533                                   struct jsonrpc_msg *request)
534 {
535     struct jsonrpc_msg *reply;
536
537     if (!strcmp(request->method, "transact")) {
538         reply = ovsdb_jsonrpc_check_db_name(s, request);
539         if (!reply) {
540             reply = execute_transaction(s, request);
541         }
542     } else if (!strcmp(request->method, "monitor")) {
543         reply = ovsdb_jsonrpc_check_db_name(s, request);
544         if (!reply) {
545             reply = jsonrpc_create_reply(
546                 ovsdb_jsonrpc_monitor_create(s, request->params), request->id);
547         }
548     } else if (!strcmp(request->method, "monitor_cancel")) {
549         reply = ovsdb_jsonrpc_monitor_cancel(s, json_array(request->params),
550                                              request->id);
551     } else if (!strcmp(request->method, "get_schema")) {
552         reply = ovsdb_jsonrpc_check_db_name(s, request);
553         if (!reply) {
554             reply = jsonrpc_create_reply(
555                 ovsdb_schema_to_json(s->remote->server->db->schema),
556                 request->id);
557         }
558     } else if (!strcmp(request->method, "list_dbs")) {
559         reply = jsonrpc_create_reply(
560             json_array_create_1(json_string_create(get_db_name(s))),
561             request->id);
562     } else if (!strcmp(request->method, "echo")) {
563         reply = jsonrpc_create_reply(json_clone(request->params), request->id);
564     } else {
565         reply = jsonrpc_create_error(json_string_create("unknown method"),
566                                      request->id);
567     }
568
569     if (reply) {
570         jsonrpc_msg_destroy(request);
571         jsonrpc_session_send(s->js, reply);
572     }
573 }
574
575 static void
576 execute_cancel(struct ovsdb_jsonrpc_session *s, struct jsonrpc_msg *request)
577 {
578     if (json_array(request->params)->n == 1) {
579         struct ovsdb_jsonrpc_trigger *t;
580         struct json *id;
581
582         id = request->params->u.array.elems[0];
583         t = ovsdb_jsonrpc_trigger_find(s, id, json_hash(id, 0));
584         if (t) {
585             ovsdb_jsonrpc_trigger_complete(t);
586         }
587     }
588 }
589
590 static void
591 ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *s,
592                                  struct jsonrpc_msg *request)
593 {
594     if (!strcmp(request->method, "cancel")) {
595         execute_cancel(s, request);
596     }
597     jsonrpc_msg_destroy(request);
598 }
599 \f
600 /* JSON-RPC database server triggers.
601  *
602  * (Every transaction is treated as a trigger even if it doesn't actually have
603  * any "wait" operations.) */
604
605 struct ovsdb_jsonrpc_trigger {
606     struct ovsdb_trigger trigger;
607     struct ovsdb_jsonrpc_session *session;
608     struct hmap_node hmap_node; /* In session's "triggers" hmap. */
609     struct json *id;
610 };
611
612 static void
613 ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *s,
614                              struct json *id, struct json *params)
615 {
616     struct ovsdb_jsonrpc_trigger *t;
617     size_t hash;
618
619     /* Check for duplicate ID. */
620     hash = json_hash(id, 0);
621     t = ovsdb_jsonrpc_trigger_find(s, id, hash);
622     if (t) {
623         struct jsonrpc_msg *msg;
624
625         msg = jsonrpc_create_error(json_string_create("duplicate request ID"),
626                                    id);
627         jsonrpc_session_send(s->js, msg);
628         json_destroy(id);
629         json_destroy(params);
630         return;
631     }
632
633     /* Insert into trigger table. */
634     t = xmalloc(sizeof *t);
635     ovsdb_trigger_init(s->remote->server->db,
636                        &t->trigger, params, &s->completions,
637                        time_msec());
638     t->session = s;
639     t->id = id;
640     hmap_insert(&s->triggers, &t->hmap_node, hash);
641
642     /* Complete early if possible. */
643     if (ovsdb_trigger_is_complete(&t->trigger)) {
644         ovsdb_jsonrpc_trigger_complete(t);
645     }
646 }
647
648 static struct ovsdb_jsonrpc_trigger *
649 ovsdb_jsonrpc_trigger_find(struct ovsdb_jsonrpc_session *s,
650                            const struct json *id, size_t hash)
651 {
652     struct ovsdb_jsonrpc_trigger *t;
653
654     HMAP_FOR_EACH_WITH_HASH (t, hmap_node, hash, &s->triggers) {
655         if (json_equal(t->id, id)) {
656             return t;
657         }
658     }
659
660     return NULL;
661 }
662
663 static void
664 ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *t)
665 {
666     struct ovsdb_jsonrpc_session *s = t->session;
667
668     if (jsonrpc_session_is_connected(s->js)) {
669         struct jsonrpc_msg *reply;
670         struct json *result;
671
672         result = ovsdb_trigger_steal_result(&t->trigger);
673         if (result) {
674             reply = jsonrpc_create_reply(result, t->id);
675         } else {
676             reply = jsonrpc_create_error(json_string_create("canceled"),
677                                          t->id);
678         }
679         jsonrpc_session_send(s->js, reply);
680     }
681
682     json_destroy(t->id);
683     ovsdb_trigger_destroy(&t->trigger);
684     hmap_remove(&s->triggers, &t->hmap_node);
685     free(t);
686 }
687
688 static void
689 ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *s)
690 {
691     struct ovsdb_jsonrpc_trigger *t, *next;
692     HMAP_FOR_EACH_SAFE (t, next, hmap_node, &s->triggers) {
693         ovsdb_jsonrpc_trigger_complete(t);
694     }
695 }
696
697 static void
698 ovsdb_jsonrpc_trigger_complete_done(struct ovsdb_jsonrpc_session *s)
699 {
700     while (!list_is_empty(&s->completions)) {
701         struct ovsdb_jsonrpc_trigger *t
702             = CONTAINER_OF(s->completions.next,
703                            struct ovsdb_jsonrpc_trigger, trigger.node);
704         ovsdb_jsonrpc_trigger_complete(t);
705     }
706 }
707 \f
708 /* JSON-RPC database table monitors. */
709
710 enum ovsdb_jsonrpc_monitor_selection {
711     OJMS_INITIAL = 1 << 0,      /* All rows when monitor is created. */
712     OJMS_INSERT = 1 << 1,       /* New rows. */
713     OJMS_DELETE = 1 << 2,       /* Deleted rows. */
714     OJMS_MODIFY = 1 << 3        /* Modified rows. */
715 };
716
717 /* A particular column being monitored. */
718 struct ovsdb_jsonrpc_monitor_column {
719     const struct ovsdb_column *column;
720     enum ovsdb_jsonrpc_monitor_selection select;
721 };
722
723 /* A particular table being monitored. */
724 struct ovsdb_jsonrpc_monitor_table {
725     const struct ovsdb_table *table;
726
727     /* This is the union (bitwise-OR) of the 'select' values in all of the
728      * members of 'columns' below. */
729     enum ovsdb_jsonrpc_monitor_selection select;
730
731     /* Columns being monitored. */
732     struct ovsdb_jsonrpc_monitor_column *columns;
733     size_t n_columns;
734 };
735
736 /* A collection of tables being monitored. */
737 struct ovsdb_jsonrpc_monitor {
738     struct ovsdb_replica replica;
739     struct ovsdb_jsonrpc_session *session;
740     struct hmap_node node;      /* In ovsdb_jsonrpc_session's "monitors". */
741
742     struct json *monitor_id;
743     struct shash tables;     /* Holds "struct ovsdb_jsonrpc_monitor_table"s. */
744 };
745
746 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class;
747
748 struct ovsdb_jsonrpc_monitor *ovsdb_jsonrpc_monitor_find(
749     struct ovsdb_jsonrpc_session *, const struct json *monitor_id);
750 static void ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *);
751 static struct json *ovsdb_jsonrpc_monitor_get_initial(
752     const struct ovsdb_jsonrpc_monitor *);
753
754 static bool
755 parse_bool(struct ovsdb_parser *parser, const char *name, bool default_value)
756 {
757     const struct json *json;
758
759     json = ovsdb_parser_member(parser, name, OP_BOOLEAN | OP_OPTIONAL);
760     return json ? json_boolean(json) : default_value;
761 }
762
763 struct ovsdb_jsonrpc_monitor *
764 ovsdb_jsonrpc_monitor_find(struct ovsdb_jsonrpc_session *s,
765                            const struct json *monitor_id)
766 {
767     struct ovsdb_jsonrpc_monitor *m;
768
769     HMAP_FOR_EACH_WITH_HASH (m, node, json_hash(monitor_id, 0), &s->monitors) {
770         if (json_equal(m->monitor_id, monitor_id)) {
771             return m;
772         }
773     }
774
775     return NULL;
776 }
777
778 static void
779 ovsdb_jsonrpc_add_monitor_column(struct ovsdb_jsonrpc_monitor_table *mt,
780                                  const struct ovsdb_column *column,
781                                  enum ovsdb_jsonrpc_monitor_selection select,
782                                  size_t *allocated_columns)
783 {
784     struct ovsdb_jsonrpc_monitor_column *c;
785
786     if (mt->n_columns >= *allocated_columns) {
787         mt->columns = x2nrealloc(mt->columns, allocated_columns,
788                                  sizeof *mt->columns);
789     }
790
791     c = &mt->columns[mt->n_columns++];
792     c->column = column;
793     c->select = select;
794 }
795
796 static int
797 compare_ovsdb_jsonrpc_monitor_column(const void *a_, const void *b_)
798 {
799     const struct ovsdb_jsonrpc_monitor_column *a = a_;
800     const struct ovsdb_jsonrpc_monitor_column *b = b_;
801
802     return a->column < b->column ? -1 : a->column > b->column;
803 }
804
805 static struct ovsdb_error * WARN_UNUSED_RESULT
806 ovsdb_jsonrpc_parse_monitor_request(struct ovsdb_jsonrpc_monitor_table *mt,
807                                     const struct json *monitor_request,
808                                     size_t *allocated_columns)
809 {
810     const struct ovsdb_table_schema *ts = mt->table->schema;
811     enum ovsdb_jsonrpc_monitor_selection select;
812     const struct json *columns, *select_json;
813     struct ovsdb_parser parser;
814     struct ovsdb_error *error;
815
816     ovsdb_parser_init(&parser, monitor_request, "table %s", ts->name);
817     columns = ovsdb_parser_member(&parser, "columns", OP_ARRAY | OP_OPTIONAL);
818     select_json = ovsdb_parser_member(&parser, "select",
819                                       OP_OBJECT | OP_OPTIONAL);
820     error = ovsdb_parser_finish(&parser);
821     if (error) {
822         return error;
823     }
824
825     if (select_json) {
826         select = 0;
827         ovsdb_parser_init(&parser, select_json, "table %s select", ts->name);
828         if (parse_bool(&parser, "initial", true)) {
829             select |= OJMS_INITIAL;
830         }
831         if (parse_bool(&parser, "insert", true)) {
832             select |= OJMS_INSERT;
833         }
834         if (parse_bool(&parser, "delete", true)) {
835             select |= OJMS_DELETE;
836         }
837         if (parse_bool(&parser, "modify", true)) {
838             select |= OJMS_MODIFY;
839         }
840         error = ovsdb_parser_finish(&parser);
841         if (error) {
842             return error;
843         }
844     } else {
845         select = OJMS_INITIAL | OJMS_INSERT | OJMS_DELETE | OJMS_MODIFY;
846     }
847     mt->select |= select;
848
849     if (columns) {
850         size_t i;
851
852         if (columns->type != JSON_ARRAY) {
853             return ovsdb_syntax_error(columns, NULL,
854                                       "array of column names expected");
855         }
856
857         for (i = 0; i < columns->u.array.n; i++) {
858             const struct ovsdb_column *column;
859             const char *s;
860
861             if (columns->u.array.elems[i]->type != JSON_STRING) {
862                 return ovsdb_syntax_error(columns, NULL,
863                                           "array of column names expected");
864             }
865
866             s = columns->u.array.elems[i]->u.string;
867             column = shash_find_data(&mt->table->schema->columns, s);
868             if (!column) {
869                 return ovsdb_syntax_error(columns, NULL, "%s is not a valid "
870                                           "column name", s);
871             }
872             ovsdb_jsonrpc_add_monitor_column(mt, column, select,
873                                              allocated_columns);
874         }
875     } else {
876         struct shash_node *node;
877
878         SHASH_FOR_EACH (node, &ts->columns) {
879             const struct ovsdb_column *column = node->data;
880             if (column->index != OVSDB_COL_UUID) {
881                 ovsdb_jsonrpc_add_monitor_column(mt, column, select,
882                                                  allocated_columns);
883             }
884         }
885     }
886
887     return NULL;
888 }
889
890 static struct json *
891 ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s,
892                              struct json *params)
893 {
894     struct ovsdb_jsonrpc_monitor *m = NULL;
895     struct json *monitor_id, *monitor_requests;
896     struct ovsdb_error *error = NULL;
897     struct shash_node *node;
898     struct json *json;
899
900     if (json_array(params)->n != 3) {
901         error = ovsdb_syntax_error(params, NULL, "invalid parameters");
902         goto error;
903     }
904     monitor_id = params->u.array.elems[1];
905     monitor_requests = params->u.array.elems[2];
906     if (monitor_requests->type != JSON_OBJECT) {
907         error = ovsdb_syntax_error(monitor_requests, NULL,
908                                    "monitor-requests must be object");
909         goto error;
910     }
911
912     if (ovsdb_jsonrpc_monitor_find(s, monitor_id)) {
913         error = ovsdb_syntax_error(monitor_id, NULL, "duplicate monitor ID");
914         goto error;
915     }
916
917     m = xzalloc(sizeof *m);
918     ovsdb_replica_init(&m->replica, &ovsdb_jsonrpc_replica_class);
919     ovsdb_add_replica(s->remote->server->db, &m->replica);
920     m->session = s;
921     hmap_insert(&s->monitors, &m->node, json_hash(monitor_id, 0));
922     m->monitor_id = json_clone(monitor_id);
923     shash_init(&m->tables);
924
925     SHASH_FOR_EACH (node, json_object(monitor_requests)) {
926         const struct ovsdb_table *table;
927         struct ovsdb_jsonrpc_monitor_table *mt;
928         size_t allocated_columns;
929         const struct json *mr_value;
930         size_t i;
931
932         table = ovsdb_get_table(s->remote->server->db, node->name);
933         if (!table) {
934             error = ovsdb_syntax_error(NULL, NULL,
935                                        "no table named %s", node->name);
936             goto error;
937         }
938
939         mt = xzalloc(sizeof *mt);
940         mt->table = table;
941         shash_add(&m->tables, table->schema->name, mt);
942
943         /* Parse columns. */
944         mr_value = node->data;
945         allocated_columns = 0;
946         if (mr_value->type == JSON_ARRAY) {
947             const struct json_array *array = &mr_value->u.array;
948
949             for (i = 0; i < array->n; i++) {
950                 error = ovsdb_jsonrpc_parse_monitor_request(
951                     mt, array->elems[i], &allocated_columns);
952                 if (error) {
953                     goto error;
954                 }
955             }
956         } else {
957             error = ovsdb_jsonrpc_parse_monitor_request(
958                 mt, mr_value, &allocated_columns);
959             if (error) {
960                 goto error;
961             }
962         }
963
964         /* Check for duplicate columns. */
965         qsort(mt->columns, mt->n_columns, sizeof *mt->columns,
966               compare_ovsdb_jsonrpc_monitor_column);
967         for (i = 1; i < mt->n_columns; i++) {
968             if (mt->columns[i].column == mt->columns[i - 1].column) {
969                 error = ovsdb_syntax_error(mr_value, NULL, "column %s "
970                                            "mentioned more than once",
971                                            mt->columns[i].column->name);
972                 goto error;
973             }
974         }
975     }
976
977     return ovsdb_jsonrpc_monitor_get_initial(m);
978
979 error:
980     if (m) {
981         ovsdb_remove_replica(s->remote->server->db, &m->replica);
982     }
983
984     json = ovsdb_error_to_json(error);
985     ovsdb_error_destroy(error);
986     return json;
987 }
988
989 static struct jsonrpc_msg *
990 ovsdb_jsonrpc_monitor_cancel(struct ovsdb_jsonrpc_session *s,
991                              struct json_array *params,
992                              const struct json *request_id)
993 {
994     if (params->n != 1) {
995         return jsonrpc_create_error(json_string_create("invalid parameters"),
996                                     request_id);
997     } else {
998         struct ovsdb_jsonrpc_monitor *m;
999
1000         m = ovsdb_jsonrpc_monitor_find(s, params->elems[0]);
1001         if (!m) {
1002             return jsonrpc_create_error(json_string_create("unknown monitor"),
1003                                         request_id);
1004         } else {
1005             ovsdb_remove_replica(s->remote->server->db, &m->replica);
1006             return jsonrpc_create_reply(json_object_create(), request_id);
1007         }
1008     }
1009 }
1010
1011 static void
1012 ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *s)
1013 {
1014     struct ovsdb_jsonrpc_monitor *m, *next;
1015
1016     HMAP_FOR_EACH_SAFE (m, next, node, &s->monitors) {
1017         ovsdb_remove_replica(s->remote->server->db, &m->replica);
1018     }
1019 }
1020
1021 static struct ovsdb_jsonrpc_monitor *
1022 ovsdb_jsonrpc_monitor_cast(struct ovsdb_replica *replica)
1023 {
1024     assert(replica->class == &ovsdb_jsonrpc_replica_class);
1025     return CONTAINER_OF(replica, struct ovsdb_jsonrpc_monitor, replica);
1026 }
1027
1028 struct ovsdb_jsonrpc_monitor_aux {
1029     bool initial;               /* Sending initial contents of table? */
1030     const struct ovsdb_jsonrpc_monitor *monitor;
1031     struct json *json;          /* JSON for the whole transaction. */
1032
1033     /* Current table.  */
1034     struct ovsdb_jsonrpc_monitor_table *mt;
1035     struct json *table_json;    /* JSON for table's transaction. */
1036 };
1037
1038 static bool
1039 any_reportable_change(const struct ovsdb_jsonrpc_monitor_table *mt,
1040                       const unsigned long int *changed)
1041 {
1042     size_t i;
1043
1044     for (i = 0; i < mt->n_columns; i++) {
1045         const struct ovsdb_jsonrpc_monitor_column *c = &mt->columns[i];
1046         unsigned int idx = c->column->index;
1047
1048         if (c->select & OJMS_MODIFY && bitmap_is_set(changed, idx)) {
1049             return true;
1050         }
1051     }
1052
1053     return false;
1054 }
1055
1056 static bool
1057 ovsdb_jsonrpc_monitor_change_cb(const struct ovsdb_row *old,
1058                                 const struct ovsdb_row *new,
1059                                 const unsigned long int *changed,
1060                                 void *aux_)
1061 {
1062     struct ovsdb_jsonrpc_monitor_aux *aux = aux_;
1063     const struct ovsdb_jsonrpc_monitor *m = aux->monitor;
1064     struct ovsdb_table *table = new ? new->table : old->table;
1065     enum ovsdb_jsonrpc_monitor_selection type;
1066     struct json *old_json, *new_json;
1067     struct json *row_json;
1068     char uuid[UUID_LEN + 1];
1069     size_t i;
1070
1071     if (!aux->mt || table != aux->mt->table) {
1072         aux->mt = shash_find_data(&m->tables, table->schema->name);
1073         aux->table_json = NULL;
1074         if (!aux->mt) {
1075             /* We don't care about rows in this table at all.  Tell the caller
1076              * to skip it.  */
1077             return false;
1078         }
1079     }
1080
1081     type = (aux->initial ? OJMS_INITIAL
1082             : !old ? OJMS_INSERT
1083             : !new ? OJMS_DELETE
1084             : OJMS_MODIFY);
1085     if (!(aux->mt->select & type)) {
1086         /* We don't care about this type of change (but do want to be called
1087          * back for changes to other rows in the same table). */
1088         return true;
1089     }
1090
1091     if (type == OJMS_MODIFY && !any_reportable_change(aux->mt, changed)) {
1092         /* Nothing of interest changed. */
1093         return true;
1094     }
1095
1096     old_json = new_json = NULL;
1097     if (type & (OJMS_DELETE | OJMS_MODIFY)) {
1098         old_json = json_object_create();
1099     }
1100     if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
1101         new_json = json_object_create();
1102     }
1103     for (i = 0; i < aux->mt->n_columns; i++) {
1104         const struct ovsdb_jsonrpc_monitor_column *c = &aux->mt->columns[i];
1105         const struct ovsdb_column *column = c->column;
1106         unsigned int idx = c->column->index;
1107
1108         if (!(type & c->select)) {
1109             /* We don't care about this type of change for this particular
1110              * column (but we will care about it for some other column). */
1111             continue;
1112         }
1113
1114         if ((type == OJMS_MODIFY && bitmap_is_set(changed, idx))
1115             || type == OJMS_DELETE) {
1116             json_object_put(old_json, column->name,
1117                             ovsdb_datum_to_json(&old->fields[idx],
1118                                                 &column->type));
1119         }
1120         if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
1121             json_object_put(new_json, column->name,
1122                             ovsdb_datum_to_json(&new->fields[idx],
1123                                                 &column->type));
1124         }
1125     }
1126
1127     /* Create JSON object for transaction overall. */
1128     if (!aux->json) {
1129         aux->json = json_object_create();
1130     }
1131
1132     /* Create JSON object for transaction on this table. */
1133     if (!aux->table_json) {
1134         aux->table_json = json_object_create();
1135         json_object_put(aux->json, aux->mt->table->schema->name,
1136                         aux->table_json);
1137     }
1138
1139     /* Create JSON object for transaction on this row. */
1140     row_json = json_object_create();
1141     if (old_json) {
1142         json_object_put(row_json, "old", old_json);
1143     }
1144     if (new_json) {
1145         json_object_put(row_json, "new", new_json);
1146     }
1147
1148     /* Add JSON row to JSON table. */
1149     snprintf(uuid, sizeof uuid,
1150              UUID_FMT, UUID_ARGS(ovsdb_row_get_uuid(new ? new : old)));
1151     json_object_put(aux->table_json, uuid, row_json);
1152
1153     return true;
1154 }
1155
1156 static void
1157 ovsdb_jsonrpc_monitor_init_aux(struct ovsdb_jsonrpc_monitor_aux *aux,
1158                                const struct ovsdb_jsonrpc_monitor *m,
1159                                bool initial)
1160 {
1161     aux->initial = initial;
1162     aux->monitor = m;
1163     aux->json = NULL;
1164     aux->mt = NULL;
1165     aux->table_json = NULL;
1166 }
1167
1168 static struct ovsdb_error *
1169 ovsdb_jsonrpc_monitor_commit(struct ovsdb_replica *replica,
1170                              const struct ovsdb_txn *txn,
1171                              bool durable OVS_UNUSED)
1172 {
1173     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1174     struct ovsdb_jsonrpc_monitor_aux aux;
1175
1176     ovsdb_jsonrpc_monitor_init_aux(&aux, m, false);
1177     ovsdb_txn_for_each_change(txn, ovsdb_jsonrpc_monitor_change_cb, &aux);
1178     if (aux.json) {
1179         struct jsonrpc_msg *msg;
1180         struct json *params;
1181
1182         params = json_array_create_2(json_clone(aux.monitor->monitor_id),
1183                                      aux.json);
1184         msg = jsonrpc_create_notify("update", params);
1185         jsonrpc_session_send(aux.monitor->session->js, msg);
1186     }
1187
1188     return NULL;
1189 }
1190
1191 static struct json *
1192 ovsdb_jsonrpc_monitor_get_initial(const struct ovsdb_jsonrpc_monitor *m)
1193 {
1194     struct ovsdb_jsonrpc_monitor_aux aux;
1195     struct shash_node *node;
1196
1197     ovsdb_jsonrpc_monitor_init_aux(&aux, m, true);
1198     SHASH_FOR_EACH (node, &m->tables) {
1199         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1200
1201         if (mt->select & OJMS_INITIAL) {
1202             struct ovsdb_row *row;
1203
1204             HMAP_FOR_EACH (row, hmap_node, &mt->table->rows) {
1205                 ovsdb_jsonrpc_monitor_change_cb(NULL, row, NULL, &aux);
1206             }
1207         }
1208     }
1209     return aux.json ? aux.json : json_object_create();
1210 }
1211
1212 static void
1213 ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *replica)
1214 {
1215     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1216     struct shash_node *node;
1217
1218     json_destroy(m->monitor_id);
1219     SHASH_FOR_EACH (node, &m->tables) {
1220         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1221         free(mt->columns);
1222         free(mt);
1223     }
1224     shash_destroy(&m->tables);
1225     hmap_remove(&m->session->monitors, &m->node);
1226     free(m);
1227 }
1228
1229 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class = {
1230     ovsdb_jsonrpc_monitor_commit,
1231     ovsdb_jsonrpc_monitor_destroy
1232 };