ovsdb: Report the number of connections for inbound Managers.
[sliver-openvswitch.git] / ovsdb / jsonrpc-server.c
1 /* Copyright (c) 2009, 2010, 2011 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 "dynamic-string.h"
26 #include "json.h"
27 #include "jsonrpc.h"
28 #include "ovsdb-error.h"
29 #include "ovsdb-parser.h"
30 #include "ovsdb.h"
31 #include "reconnect.h"
32 #include "row.h"
33 #include "stream.h"
34 #include "table.h"
35 #include "timeval.h"
36 #include "transaction.h"
37 #include "trigger.h"
38 #include "vlog.h"
39
40 VLOG_DEFINE_THIS_MODULE(ovsdb_jsonrpc_server);
41
42 struct ovsdb_jsonrpc_remote;
43 struct ovsdb_jsonrpc_session;
44
45 /* Message rate-limiting. */
46 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
47
48 /* Sessions. */
49 static struct ovsdb_jsonrpc_session *ovsdb_jsonrpc_session_create(
50     struct ovsdb_jsonrpc_remote *, struct jsonrpc_session *);
51 static void ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *);
52 static void ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *);
53 static void ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *);
54 static void ovsdb_jsonrpc_session_reconnect_all(struct ovsdb_jsonrpc_remote *);
55 static void ovsdb_jsonrpc_session_set_all_options(
56     struct ovsdb_jsonrpc_remote *, const struct ovsdb_jsonrpc_options *);
57 static bool ovsdb_jsonrpc_session_get_status(
58     const struct ovsdb_jsonrpc_remote *,
59     struct ovsdb_jsonrpc_remote_status *);
60
61 /* Triggers. */
62 static void ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *,
63                                          struct json *id, struct json *params);
64 static struct ovsdb_jsonrpc_trigger *ovsdb_jsonrpc_trigger_find(
65     struct ovsdb_jsonrpc_session *, const struct json *id, size_t hash);
66 static void ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *);
67 static void ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *);
68 static void ovsdb_jsonrpc_trigger_complete_done(
69     struct ovsdb_jsonrpc_session *);
70
71 /* Monitors. */
72 static struct json *ovsdb_jsonrpc_monitor_create(
73     struct ovsdb_jsonrpc_session *, struct json *params);
74 static struct jsonrpc_msg *ovsdb_jsonrpc_monitor_cancel(
75     struct ovsdb_jsonrpc_session *,
76     struct json_array *params,
77     const struct json *request_id);
78 static void ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *);
79 \f
80 /* JSON-RPC database server. */
81
82 struct ovsdb_jsonrpc_server {
83     struct ovsdb *db;
84     unsigned int n_sessions, max_sessions;
85     struct shash remotes;      /* Contains "struct ovsdb_jsonrpc_remote *"s. */
86 };
87
88 /* A configured remote.  This is either a passive stream listener plus a list
89  * of the currently connected sessions, or a list of exactly one active
90  * session. */
91 struct ovsdb_jsonrpc_remote {
92     struct ovsdb_jsonrpc_server *server;
93     struct pstream *listener;   /* Listener, if passive. */
94     struct list sessions;       /* List of "struct ovsdb_jsonrpc_session"s. */
95 };
96
97 static struct ovsdb_jsonrpc_remote *ovsdb_jsonrpc_server_add_remote(
98     struct ovsdb_jsonrpc_server *, const char *name);
99 static void ovsdb_jsonrpc_server_del_remote(struct shash_node *);
100
101 struct ovsdb_jsonrpc_server *
102 ovsdb_jsonrpc_server_create(struct ovsdb *db)
103 {
104     struct ovsdb_jsonrpc_server *server = xzalloc(sizeof *server);
105     server->db = db;
106     server->max_sessions = 64;
107     shash_init(&server->remotes);
108     return server;
109 }
110
111 void
112 ovsdb_jsonrpc_server_destroy(struct ovsdb_jsonrpc_server *svr)
113 {
114     struct shash_node *node, *next;
115
116     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
117         ovsdb_jsonrpc_server_del_remote(node);
118     }
119     shash_destroy(&svr->remotes);
120     free(svr);
121 }
122
123 struct ovsdb_jsonrpc_options *
124 ovsdb_jsonrpc_default_options(void)
125 {
126     struct ovsdb_jsonrpc_options *options = xzalloc(sizeof *options);
127     options->probe_interval = RECONNECT_DEFAULT_PROBE_INTERVAL;
128     options->max_backoff = RECONNECT_DEFAULT_MAX_BACKOFF;
129     return options;
130 }
131
132 /* Sets 'svr''s current set of remotes to the names in 'new_remotes', with
133  * options in the struct ovsdb_jsonrpc_options supplied as the data values.
134  *
135  * A remote is an active or passive stream connection method, e.g. "pssl:" or
136  * "tcp:1.2.3.4". */
137 void
138 ovsdb_jsonrpc_server_set_remotes(struct ovsdb_jsonrpc_server *svr,
139                                  const struct shash *new_remotes)
140 {
141     struct shash_node *node, *next;
142
143     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
144         if (!shash_find(new_remotes, node->name)) {
145             VLOG_INFO("%s: remote deconfigured", node->name);
146             ovsdb_jsonrpc_server_del_remote(node);
147         }
148     }
149     SHASH_FOR_EACH (node, new_remotes) {
150         const struct ovsdb_jsonrpc_options *options = node->data;
151         struct ovsdb_jsonrpc_remote *remote;
152
153         remote = shash_find_data(&svr->remotes, node->name);
154         if (!remote) {
155             remote = ovsdb_jsonrpc_server_add_remote(svr, node->name);
156             if (!remote) {
157                 continue;
158             }
159         }
160
161         ovsdb_jsonrpc_session_set_all_options(remote, options);
162     }
163 }
164
165 static struct ovsdb_jsonrpc_remote *
166 ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *svr,
167                                 const char *name)
168 {
169     struct ovsdb_jsonrpc_remote *remote;
170     struct pstream *listener;
171     int error;
172
173     error = jsonrpc_pstream_open(name, &listener);
174     if (error && error != EAFNOSUPPORT) {
175         VLOG_ERR_RL(&rl, "%s: listen failed: %s", name, strerror(error));
176         return NULL;
177     }
178
179     remote = xmalloc(sizeof *remote);
180     remote->server = svr;
181     remote->listener = listener;
182     list_init(&remote->sessions);
183     shash_add(&svr->remotes, name, remote);
184
185     if (!listener) {
186         ovsdb_jsonrpc_session_create(remote, jsonrpc_session_open(name));
187     }
188     return remote;
189 }
190
191 static void
192 ovsdb_jsonrpc_server_del_remote(struct shash_node *node)
193 {
194     struct ovsdb_jsonrpc_remote *remote = node->data;
195
196     ovsdb_jsonrpc_session_close_all(remote);
197     pstream_close(remote->listener);
198     shash_delete(&remote->server->remotes, node);
199     free(remote);
200 }
201
202 /* Stores status information for the remote named 'target', which should have
203  * been configured on 'svr' with a call to ovsdb_jsonrpc_server_set_remotes(),
204  * into '*status'.  On success returns true, on failure (if 'svr' doesn't have
205  * a remote named 'target' or if that remote is an inbound remote that has no
206  * active connections) returns false.  On failure, 'status' will be zeroed.
207  */
208 bool
209 ovsdb_jsonrpc_server_get_remote_status(
210     const struct ovsdb_jsonrpc_server *svr, const char *target,
211     struct ovsdb_jsonrpc_remote_status *status)
212 {
213     const struct ovsdb_jsonrpc_remote *remote;
214
215     memset(status, 0, sizeof *status);
216
217     remote = shash_find_data(&svr->remotes, target);
218     return remote && ovsdb_jsonrpc_session_get_status(remote, status);
219 }
220
221 /* Forces all of the JSON-RPC sessions managed by 'svr' to disconnect and
222  * reconnect. */
223 void
224 ovsdb_jsonrpc_server_reconnect(struct ovsdb_jsonrpc_server *svr)
225 {
226     struct shash_node *node;
227
228     SHASH_FOR_EACH (node, &svr->remotes) {
229         struct ovsdb_jsonrpc_remote *remote = node->data;
230
231         ovsdb_jsonrpc_session_reconnect_all(remote);
232     }
233 }
234
235 void
236 ovsdb_jsonrpc_server_run(struct ovsdb_jsonrpc_server *svr)
237 {
238     struct shash_node *node;
239
240     SHASH_FOR_EACH (node, &svr->remotes) {
241         struct ovsdb_jsonrpc_remote *remote = node->data;
242
243         if (remote->listener && svr->n_sessions < svr->max_sessions) {
244             struct stream *stream;
245             int error;
246
247             error = pstream_accept(remote->listener, &stream);
248             if (!error) {
249                 struct jsonrpc_session *js;
250                 js = jsonrpc_session_open_unreliably(jsonrpc_open(stream));
251                 ovsdb_jsonrpc_session_create(remote, js);
252             } else if (error != EAGAIN) {
253                 VLOG_WARN_RL(&rl, "%s: accept failed: %s",
254                              pstream_get_name(remote->listener),
255                              strerror(error));
256             }
257         }
258
259         ovsdb_jsonrpc_session_run_all(remote);
260     }
261 }
262
263 void
264 ovsdb_jsonrpc_server_wait(struct ovsdb_jsonrpc_server *svr)
265 {
266     struct shash_node *node;
267
268     SHASH_FOR_EACH (node, &svr->remotes) {
269         struct ovsdb_jsonrpc_remote *remote = node->data;
270
271         if (remote->listener && svr->n_sessions < svr->max_sessions) {
272             pstream_wait(remote->listener);
273         }
274
275         ovsdb_jsonrpc_session_wait_all(remote);
276     }
277 }
278 \f
279 /* JSON-RPC database server session. */
280
281 struct ovsdb_jsonrpc_session {
282     struct ovsdb_jsonrpc_remote *remote;
283     struct list node;           /* Element in remote's sessions list. */
284
285     /* Triggers. */
286     struct hmap triggers;       /* Hmap of "struct ovsdb_jsonrpc_trigger"s. */
287     struct list completions;    /* Completed triggers. */
288
289     /* Monitors. */
290     struct hmap monitors;       /* Hmap of "struct ovsdb_jsonrpc_monitor"s. */
291
292     /* Network connectivity. */
293     struct jsonrpc_session *js;  /* JSON-RPC session. */
294     unsigned int js_seqno;       /* Last jsonrpc_session_get_seqno() value. */
295 };
296
297 static void ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *);
298 static int ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *);
299 static void ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *);
300 static void ovsdb_jsonrpc_session_set_options(
301     struct ovsdb_jsonrpc_session *, const struct ovsdb_jsonrpc_options *);
302 static void ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *,
303                                              struct jsonrpc_msg *);
304 static void ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *,
305                                              struct jsonrpc_msg *);
306
307 static struct ovsdb_jsonrpc_session *
308 ovsdb_jsonrpc_session_create(struct ovsdb_jsonrpc_remote *remote,
309                              struct jsonrpc_session *js)
310 {
311     struct ovsdb_jsonrpc_session *s;
312
313     s = xzalloc(sizeof *s);
314     s->remote = remote;
315     list_push_back(&remote->sessions, &s->node);
316     hmap_init(&s->triggers);
317     hmap_init(&s->monitors);
318     list_init(&s->completions);
319     s->js = js;
320     s->js_seqno = jsonrpc_session_get_seqno(js);
321
322     remote->server->n_sessions++;
323
324     return s;
325 }
326
327 static void
328 ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *s)
329 {
330     ovsdb_jsonrpc_monitor_remove_all(s);
331     jsonrpc_session_close(s->js);
332     list_remove(&s->node);
333     s->remote->server->n_sessions--;
334     free(s);
335 }
336
337 static int
338 ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *s)
339 {
340     jsonrpc_session_run(s->js);
341     if (s->js_seqno != jsonrpc_session_get_seqno(s->js)) {
342         s->js_seqno = jsonrpc_session_get_seqno(s->js);
343         ovsdb_jsonrpc_trigger_complete_all(s);
344         ovsdb_jsonrpc_monitor_remove_all(s);
345     }
346
347     ovsdb_jsonrpc_trigger_complete_done(s);
348
349     if (!jsonrpc_session_get_backlog(s->js)) {
350         struct jsonrpc_msg *msg = jsonrpc_session_recv(s->js);
351         if (msg) {
352             if (msg->type == JSONRPC_REQUEST) {
353                 ovsdb_jsonrpc_session_got_request(s, msg);
354             } else if (msg->type == JSONRPC_NOTIFY) {
355                 ovsdb_jsonrpc_session_got_notify(s, msg);
356             } else {
357                 VLOG_WARN("%s: received unexpected %s message",
358                           jsonrpc_session_get_name(s->js),
359                           jsonrpc_msg_type_to_string(msg->type));
360                 jsonrpc_session_force_reconnect(s->js);
361                 jsonrpc_msg_destroy(msg);
362             }
363         }
364     }
365     return jsonrpc_session_is_alive(s->js) ? 0 : ETIMEDOUT;
366 }
367
368 static void
369 ovsdb_jsonrpc_session_set_options(struct ovsdb_jsonrpc_session *session,
370                                   const struct ovsdb_jsonrpc_options *options)
371 {
372     jsonrpc_session_set_max_backoff(session->js, options->max_backoff);
373     jsonrpc_session_set_probe_interval(session->js, options->probe_interval);
374 }
375
376 static void
377 ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *remote)
378 {
379     struct ovsdb_jsonrpc_session *s, *next;
380
381     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
382         int error = ovsdb_jsonrpc_session_run(s);
383         if (error) {
384             ovsdb_jsonrpc_session_close(s);
385         }
386     }
387 }
388
389 static void
390 ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *s)
391 {
392     jsonrpc_session_wait(s->js);
393     if (!jsonrpc_session_get_backlog(s->js)) {
394         jsonrpc_session_recv_wait(s->js);
395     }
396 }
397
398 static void
399 ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *remote)
400 {
401     struct ovsdb_jsonrpc_session *s;
402
403     LIST_FOR_EACH (s, node, &remote->sessions) {
404         ovsdb_jsonrpc_session_wait(s);
405     }
406 }
407
408 static void
409 ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *remote)
410 {
411     struct ovsdb_jsonrpc_session *s, *next;
412
413     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
414         ovsdb_jsonrpc_session_close(s);
415     }
416 }
417
418 /* Forces all of the JSON-RPC sessions managed by 'remote' to disconnect and
419  * reconnect. */
420 static void
421 ovsdb_jsonrpc_session_reconnect_all(struct ovsdb_jsonrpc_remote *remote)
422 {
423     struct ovsdb_jsonrpc_session *s, *next;
424
425     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
426         jsonrpc_session_force_reconnect(s->js);
427         if (!jsonrpc_session_is_alive(s->js)) {
428             ovsdb_jsonrpc_session_close(s);
429         }
430     }
431 }
432
433 /* Sets the options for all of the JSON-RPC sessions managed by 'remote' to
434  * 'options'. */
435 static void
436 ovsdb_jsonrpc_session_set_all_options(
437     struct ovsdb_jsonrpc_remote *remote,
438     const struct ovsdb_jsonrpc_options *options)
439 {
440     struct ovsdb_jsonrpc_session *s;
441
442     LIST_FOR_EACH (s, node, &remote->sessions) {
443         ovsdb_jsonrpc_session_set_options(s, options);
444     }
445 }
446
447 static bool
448 ovsdb_jsonrpc_session_get_status(const struct ovsdb_jsonrpc_remote *remote,
449                                  struct ovsdb_jsonrpc_remote_status *status)
450 {
451     const struct ovsdb_jsonrpc_session *s;
452     const struct jsonrpc_session *js;
453     struct reconnect_stats rstats;
454
455     if (list_is_empty(&remote->sessions)) {
456         return false;
457     }
458     s = CONTAINER_OF(remote->sessions.next, struct ovsdb_jsonrpc_session, node);
459     js = s->js;
460
461     status->is_connected = jsonrpc_session_is_connected(js);
462     status->last_error = jsonrpc_session_get_status(js);
463
464     jsonrpc_session_get_reconnect_stats(js, &rstats);
465     status->state = rstats.state;
466     status->sec_since_connect = rstats.msec_since_connect == UINT_MAX
467         ? UINT_MAX : rstats.msec_since_connect / 1000;
468     status->sec_since_disconnect = rstats.msec_since_disconnect == UINT_MAX
469         ? UINT_MAX : rstats.msec_since_disconnect / 1000;
470
471     status->n_connections = list_size(&remote->sessions);
472
473     return true;
474 }
475
476 static const char *
477 get_db_name(const struct ovsdb_jsonrpc_session *s)
478 {
479     return s->remote->server->db->schema->name;
480 }
481
482 static struct jsonrpc_msg *
483 ovsdb_jsonrpc_check_db_name(const struct ovsdb_jsonrpc_session *s,
484                             const struct jsonrpc_msg *request)
485 {
486     struct json_array *params;
487     const char *want_db_name;
488     const char *have_db_name;
489     struct ovsdb_error *error;
490     struct jsonrpc_msg *reply;
491
492     params = json_array(request->params);
493     if (!params->n || params->elems[0]->type != JSON_STRING) {
494         error = ovsdb_syntax_error(
495             request->params, NULL,
496             "%s request params must begin with <db-name>", request->method);
497         goto error;
498     }
499
500     want_db_name = params->elems[0]->u.string;
501     have_db_name = get_db_name(s);
502     if (strcmp(want_db_name, have_db_name)) {
503         error = ovsdb_syntax_error(
504             request->params, "unknown database",
505             "%s request specifies unknown database %s",
506             request->method, want_db_name);
507         goto error;
508     }
509
510     return NULL;
511
512 error:
513     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
514     ovsdb_error_destroy(error);
515     return reply;
516 }
517
518 static struct jsonrpc_msg *
519 execute_transaction(struct ovsdb_jsonrpc_session *s,
520                     struct jsonrpc_msg *request)
521 {
522     ovsdb_jsonrpc_trigger_create(s, request->id, request->params);
523     request->id = NULL;
524     request->params = NULL;
525     jsonrpc_msg_destroy(request);
526     return NULL;
527 }
528
529 static void
530 ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *s,
531                                   struct jsonrpc_msg *request)
532 {
533     struct jsonrpc_msg *reply;
534
535     if (!strcmp(request->method, "transact")) {
536         reply = ovsdb_jsonrpc_check_db_name(s, request);
537         if (!reply) {
538             reply = execute_transaction(s, request);
539         }
540     } else if (!strcmp(request->method, "monitor")) {
541         reply = ovsdb_jsonrpc_check_db_name(s, request);
542         if (!reply) {
543             reply = jsonrpc_create_reply(
544                 ovsdb_jsonrpc_monitor_create(s, request->params), request->id);
545         }
546     } else if (!strcmp(request->method, "monitor_cancel")) {
547         reply = ovsdb_jsonrpc_monitor_cancel(s, json_array(request->params),
548                                              request->id);
549     } else if (!strcmp(request->method, "get_schema")) {
550         reply = ovsdb_jsonrpc_check_db_name(s, request);
551         if (!reply) {
552             reply = jsonrpc_create_reply(
553                 ovsdb_schema_to_json(s->remote->server->db->schema),
554                 request->id);
555         }
556     } else if (!strcmp(request->method, "list_dbs")) {
557         reply = jsonrpc_create_reply(
558             json_array_create_1(json_string_create(get_db_name(s))),
559             request->id);
560     } else if (!strcmp(request->method, "echo")) {
561         reply = jsonrpc_create_reply(json_clone(request->params), request->id);
562     } else {
563         reply = jsonrpc_create_error(json_string_create("unknown method"),
564                                      request->id);
565     }
566
567     if (reply) {
568         jsonrpc_msg_destroy(request);
569         jsonrpc_session_send(s->js, reply);
570     }
571 }
572
573 static void
574 execute_cancel(struct ovsdb_jsonrpc_session *s, struct jsonrpc_msg *request)
575 {
576     if (json_array(request->params)->n == 1) {
577         struct ovsdb_jsonrpc_trigger *t;
578         struct json *id;
579
580         id = request->params->u.array.elems[0];
581         t = ovsdb_jsonrpc_trigger_find(s, id, json_hash(id, 0));
582         if (t) {
583             ovsdb_jsonrpc_trigger_complete(t);
584         }
585     }
586 }
587
588 static void
589 ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *s,
590                                  struct jsonrpc_msg *request)
591 {
592     if (!strcmp(request->method, "cancel")) {
593         execute_cancel(s, request);
594     }
595     jsonrpc_msg_destroy(request);
596 }
597 \f
598 /* JSON-RPC database server triggers.
599  *
600  * (Every transaction is treated as a trigger even if it doesn't actually have
601  * any "wait" operations.) */
602
603 struct ovsdb_jsonrpc_trigger {
604     struct ovsdb_trigger trigger;
605     struct ovsdb_jsonrpc_session *session;
606     struct hmap_node hmap_node; /* In session's "triggers" hmap. */
607     struct json *id;
608 };
609
610 static void
611 ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *s,
612                              struct json *id, struct json *params)
613 {
614     struct ovsdb_jsonrpc_trigger *t;
615     size_t hash;
616
617     /* Check for duplicate ID. */
618     hash = json_hash(id, 0);
619     t = ovsdb_jsonrpc_trigger_find(s, id, hash);
620     if (t) {
621         struct jsonrpc_msg *msg;
622
623         msg = jsonrpc_create_error(json_string_create("duplicate request ID"),
624                                    id);
625         jsonrpc_session_send(s->js, msg);
626         json_destroy(id);
627         json_destroy(params);
628         return;
629     }
630
631     /* Insert into trigger table. */
632     t = xmalloc(sizeof *t);
633     ovsdb_trigger_init(s->remote->server->db,
634                        &t->trigger, params, &s->completions,
635                        time_msec());
636     t->session = s;
637     t->id = id;
638     hmap_insert(&s->triggers, &t->hmap_node, hash);
639
640     /* Complete early if possible. */
641     if (ovsdb_trigger_is_complete(&t->trigger)) {
642         ovsdb_jsonrpc_trigger_complete(t);
643     }
644 }
645
646 static struct ovsdb_jsonrpc_trigger *
647 ovsdb_jsonrpc_trigger_find(struct ovsdb_jsonrpc_session *s,
648                            const struct json *id, size_t hash)
649 {
650     struct ovsdb_jsonrpc_trigger *t;
651
652     HMAP_FOR_EACH_WITH_HASH (t, hmap_node, hash, &s->triggers) {
653         if (json_equal(t->id, id)) {
654             return t;
655         }
656     }
657
658     return NULL;
659 }
660
661 static void
662 ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *t)
663 {
664     struct ovsdb_jsonrpc_session *s = t->session;
665
666     if (jsonrpc_session_is_connected(s->js)) {
667         struct jsonrpc_msg *reply;
668         struct json *result;
669
670         result = ovsdb_trigger_steal_result(&t->trigger);
671         if (result) {
672             reply = jsonrpc_create_reply(result, t->id);
673         } else {
674             reply = jsonrpc_create_error(json_string_create("canceled"),
675                                          t->id);
676         }
677         jsonrpc_session_send(s->js, reply);
678     }
679
680     json_destroy(t->id);
681     ovsdb_trigger_destroy(&t->trigger);
682     hmap_remove(&s->triggers, &t->hmap_node);
683     free(t);
684 }
685
686 static void
687 ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *s)
688 {
689     struct ovsdb_jsonrpc_trigger *t, *next;
690     HMAP_FOR_EACH_SAFE (t, next, hmap_node, &s->triggers) {
691         ovsdb_jsonrpc_trigger_complete(t);
692     }
693 }
694
695 static void
696 ovsdb_jsonrpc_trigger_complete_done(struct ovsdb_jsonrpc_session *s)
697 {
698     while (!list_is_empty(&s->completions)) {
699         struct ovsdb_jsonrpc_trigger *t
700             = CONTAINER_OF(s->completions.next,
701                            struct ovsdb_jsonrpc_trigger, trigger.node);
702         ovsdb_jsonrpc_trigger_complete(t);
703     }
704 }
705 \f
706 /* JSON-RPC database table monitors. */
707
708 enum ovsdb_jsonrpc_monitor_selection {
709     OJMS_INITIAL = 1 << 0,      /* All rows when monitor is created. */
710     OJMS_INSERT = 1 << 1,       /* New rows. */
711     OJMS_DELETE = 1 << 2,       /* Deleted rows. */
712     OJMS_MODIFY = 1 << 3        /* Modified rows. */
713 };
714
715 /* A particular column being monitored. */
716 struct ovsdb_jsonrpc_monitor_column {
717     const struct ovsdb_column *column;
718     enum ovsdb_jsonrpc_monitor_selection select;
719 };
720
721 /* A particular table being monitored. */
722 struct ovsdb_jsonrpc_monitor_table {
723     const struct ovsdb_table *table;
724
725     /* This is the union (bitwise-OR) of the 'select' values in all of the
726      * members of 'columns' below. */
727     enum ovsdb_jsonrpc_monitor_selection select;
728
729     /* Columns being monitored. */
730     struct ovsdb_jsonrpc_monitor_column *columns;
731     size_t n_columns;
732 };
733
734 /* A collection of tables being monitored. */
735 struct ovsdb_jsonrpc_monitor {
736     struct ovsdb_replica replica;
737     struct ovsdb_jsonrpc_session *session;
738     struct hmap_node node;      /* In ovsdb_jsonrpc_session's "monitors". */
739
740     struct json *monitor_id;
741     struct shash tables;     /* Holds "struct ovsdb_jsonrpc_monitor_table"s. */
742 };
743
744 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class;
745
746 struct ovsdb_jsonrpc_monitor *ovsdb_jsonrpc_monitor_find(
747     struct ovsdb_jsonrpc_session *, const struct json *monitor_id);
748 static void ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *);
749 static struct json *ovsdb_jsonrpc_monitor_get_initial(
750     const struct ovsdb_jsonrpc_monitor *);
751
752 static bool
753 parse_bool(struct ovsdb_parser *parser, const char *name, bool default_value)
754 {
755     const struct json *json;
756
757     json = ovsdb_parser_member(parser, name, OP_BOOLEAN | OP_OPTIONAL);
758     return json ? json_boolean(json) : default_value;
759 }
760
761 struct ovsdb_jsonrpc_monitor *
762 ovsdb_jsonrpc_monitor_find(struct ovsdb_jsonrpc_session *s,
763                            const struct json *monitor_id)
764 {
765     struct ovsdb_jsonrpc_monitor *m;
766
767     HMAP_FOR_EACH_WITH_HASH (m, node, json_hash(monitor_id, 0), &s->monitors) {
768         if (json_equal(m->monitor_id, monitor_id)) {
769             return m;
770         }
771     }
772
773     return NULL;
774 }
775
776 static void
777 ovsdb_jsonrpc_add_monitor_column(struct ovsdb_jsonrpc_monitor_table *mt,
778                                  const struct ovsdb_column *column,
779                                  enum ovsdb_jsonrpc_monitor_selection select,
780                                  size_t *allocated_columns)
781 {
782     struct ovsdb_jsonrpc_monitor_column *c;
783
784     if (mt->n_columns >= *allocated_columns) {
785         mt->columns = x2nrealloc(mt->columns, allocated_columns,
786                                  sizeof *mt->columns);
787     }
788
789     c = &mt->columns[mt->n_columns++];
790     c->column = column;
791     c->select = select;
792 }
793
794 static int
795 compare_ovsdb_jsonrpc_monitor_column(const void *a_, const void *b_)
796 {
797     const struct ovsdb_jsonrpc_monitor_column *a = a_;
798     const struct ovsdb_jsonrpc_monitor_column *b = b_;
799
800     return a->column < b->column ? -1 : a->column > b->column;
801 }
802
803 static struct ovsdb_error * WARN_UNUSED_RESULT
804 ovsdb_jsonrpc_parse_monitor_request(struct ovsdb_jsonrpc_monitor_table *mt,
805                                     const struct json *monitor_request,
806                                     size_t *allocated_columns)
807 {
808     const struct ovsdb_table_schema *ts = mt->table->schema;
809     enum ovsdb_jsonrpc_monitor_selection select;
810     const struct json *columns, *select_json;
811     struct ovsdb_parser parser;
812     struct ovsdb_error *error;
813
814     ovsdb_parser_init(&parser, monitor_request, "table %s", ts->name);
815     columns = ovsdb_parser_member(&parser, "columns", OP_ARRAY | OP_OPTIONAL);
816     select_json = ovsdb_parser_member(&parser, "select",
817                                       OP_OBJECT | OP_OPTIONAL);
818     error = ovsdb_parser_finish(&parser);
819     if (error) {
820         return error;
821     }
822
823     if (select_json) {
824         select = 0;
825         ovsdb_parser_init(&parser, select_json, "table %s select", ts->name);
826         if (parse_bool(&parser, "initial", true)) {
827             select |= OJMS_INITIAL;
828         }
829         if (parse_bool(&parser, "insert", true)) {
830             select |= OJMS_INSERT;
831         }
832         if (parse_bool(&parser, "delete", true)) {
833             select |= OJMS_DELETE;
834         }
835         if (parse_bool(&parser, "modify", true)) {
836             select |= OJMS_MODIFY;
837         }
838         error = ovsdb_parser_finish(&parser);
839         if (error) {
840             return error;
841         }
842     } else {
843         select = OJMS_INITIAL | OJMS_INSERT | OJMS_DELETE | OJMS_MODIFY;
844     }
845     mt->select |= select;
846
847     if (columns) {
848         size_t i;
849
850         if (columns->type != JSON_ARRAY) {
851             return ovsdb_syntax_error(columns, NULL,
852                                       "array of column names expected");
853         }
854
855         for (i = 0; i < columns->u.array.n; i++) {
856             const struct ovsdb_column *column;
857             const char *s;
858
859             if (columns->u.array.elems[i]->type != JSON_STRING) {
860                 return ovsdb_syntax_error(columns, NULL,
861                                           "array of column names expected");
862             }
863
864             s = columns->u.array.elems[i]->u.string;
865             column = shash_find_data(&mt->table->schema->columns, s);
866             if (!column) {
867                 return ovsdb_syntax_error(columns, NULL, "%s is not a valid "
868                                           "column name", s);
869             }
870             ovsdb_jsonrpc_add_monitor_column(mt, column, select,
871                                              allocated_columns);
872         }
873     } else {
874         struct shash_node *node;
875
876         SHASH_FOR_EACH (node, &ts->columns) {
877             const struct ovsdb_column *column = node->data;
878             if (column->index != OVSDB_COL_UUID) {
879                 ovsdb_jsonrpc_add_monitor_column(mt, column, select,
880                                                  allocated_columns);
881             }
882         }
883     }
884
885     return NULL;
886 }
887
888 static struct json *
889 ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s,
890                              struct json *params)
891 {
892     struct ovsdb_jsonrpc_monitor *m = NULL;
893     struct json *monitor_id, *monitor_requests;
894     struct ovsdb_error *error = NULL;
895     struct shash_node *node;
896     struct json *json;
897
898     if (json_array(params)->n != 3) {
899         error = ovsdb_syntax_error(params, NULL, "invalid parameters");
900         goto error;
901     }
902     monitor_id = params->u.array.elems[1];
903     monitor_requests = params->u.array.elems[2];
904     if (monitor_requests->type != JSON_OBJECT) {
905         error = ovsdb_syntax_error(monitor_requests, NULL,
906                                    "monitor-requests must be object");
907         goto error;
908     }
909
910     if (ovsdb_jsonrpc_monitor_find(s, monitor_id)) {
911         error = ovsdb_syntax_error(monitor_id, NULL, "duplicate monitor ID");
912         goto error;
913     }
914
915     m = xzalloc(sizeof *m);
916     ovsdb_replica_init(&m->replica, &ovsdb_jsonrpc_replica_class);
917     ovsdb_add_replica(s->remote->server->db, &m->replica);
918     m->session = s;
919     hmap_insert(&s->monitors, &m->node, json_hash(monitor_id, 0));
920     m->monitor_id = json_clone(monitor_id);
921     shash_init(&m->tables);
922
923     SHASH_FOR_EACH (node, json_object(monitor_requests)) {
924         const struct ovsdb_table *table;
925         struct ovsdb_jsonrpc_monitor_table *mt;
926         size_t allocated_columns;
927         const struct json *mr_value;
928         size_t i;
929
930         table = ovsdb_get_table(s->remote->server->db, node->name);
931         if (!table) {
932             error = ovsdb_syntax_error(NULL, NULL,
933                                        "no table named %s", node->name);
934             goto error;
935         }
936
937         mt = xzalloc(sizeof *mt);
938         mt->table = table;
939         shash_add(&m->tables, table->schema->name, mt);
940
941         /* Parse columns. */
942         mr_value = node->data;
943         allocated_columns = 0;
944         if (mr_value->type == JSON_ARRAY) {
945             const struct json_array *array = &mr_value->u.array;
946
947             for (i = 0; i < array->n; i++) {
948                 error = ovsdb_jsonrpc_parse_monitor_request(
949                     mt, array->elems[i], &allocated_columns);
950                 if (error) {
951                     goto error;
952                 }
953             }
954         } else {
955             error = ovsdb_jsonrpc_parse_monitor_request(
956                 mt, mr_value, &allocated_columns);
957             if (error) {
958                 goto error;
959             }
960         }
961
962         /* Check for duplicate columns. */
963         qsort(mt->columns, mt->n_columns, sizeof *mt->columns,
964               compare_ovsdb_jsonrpc_monitor_column);
965         for (i = 1; i < mt->n_columns; i++) {
966             if (mt->columns[i].column == mt->columns[i - 1].column) {
967                 error = ovsdb_syntax_error(mr_value, NULL, "column %s "
968                                            "mentioned more than once",
969                                            mt->columns[i].column->name);
970                 goto error;
971             }
972         }
973     }
974
975     return ovsdb_jsonrpc_monitor_get_initial(m);
976
977 error:
978     if (m) {
979         ovsdb_remove_replica(s->remote->server->db, &m->replica);
980     }
981
982     json = ovsdb_error_to_json(error);
983     ovsdb_error_destroy(error);
984     return json;
985 }
986
987 static struct jsonrpc_msg *
988 ovsdb_jsonrpc_monitor_cancel(struct ovsdb_jsonrpc_session *s,
989                              struct json_array *params,
990                              const struct json *request_id)
991 {
992     if (params->n != 1) {
993         return jsonrpc_create_error(json_string_create("invalid parameters"),
994                                     request_id);
995     } else {
996         struct ovsdb_jsonrpc_monitor *m;
997
998         m = ovsdb_jsonrpc_monitor_find(s, params->elems[0]);
999         if (!m) {
1000             return jsonrpc_create_error(json_string_create("unknown monitor"),
1001                                         request_id);
1002         } else {
1003             ovsdb_remove_replica(s->remote->server->db, &m->replica);
1004             return jsonrpc_create_reply(json_object_create(), request_id);
1005         }
1006     }
1007 }
1008
1009 static void
1010 ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *s)
1011 {
1012     struct ovsdb_jsonrpc_monitor *m, *next;
1013
1014     HMAP_FOR_EACH_SAFE (m, next, node, &s->monitors) {
1015         ovsdb_remove_replica(s->remote->server->db, &m->replica);
1016     }
1017 }
1018
1019 static struct ovsdb_jsonrpc_monitor *
1020 ovsdb_jsonrpc_monitor_cast(struct ovsdb_replica *replica)
1021 {
1022     assert(replica->class == &ovsdb_jsonrpc_replica_class);
1023     return CONTAINER_OF(replica, struct ovsdb_jsonrpc_monitor, replica);
1024 }
1025
1026 struct ovsdb_jsonrpc_monitor_aux {
1027     bool initial;               /* Sending initial contents of table? */
1028     const struct ovsdb_jsonrpc_monitor *monitor;
1029     struct json *json;          /* JSON for the whole transaction. */
1030
1031     /* Current table.  */
1032     struct ovsdb_jsonrpc_monitor_table *mt;
1033     struct json *table_json;    /* JSON for table's transaction. */
1034 };
1035
1036 static bool
1037 any_reportable_change(const struct ovsdb_jsonrpc_monitor_table *mt,
1038                       const unsigned long int *changed)
1039 {
1040     size_t i;
1041
1042     for (i = 0; i < mt->n_columns; i++) {
1043         const struct ovsdb_jsonrpc_monitor_column *c = &mt->columns[i];
1044         unsigned int idx = c->column->index;
1045
1046         if (c->select & OJMS_MODIFY && bitmap_is_set(changed, idx)) {
1047             return true;
1048         }
1049     }
1050
1051     return false;
1052 }
1053
1054 static bool
1055 ovsdb_jsonrpc_monitor_change_cb(const struct ovsdb_row *old,
1056                                 const struct ovsdb_row *new,
1057                                 const unsigned long int *changed,
1058                                 void *aux_)
1059 {
1060     struct ovsdb_jsonrpc_monitor_aux *aux = aux_;
1061     const struct ovsdb_jsonrpc_monitor *m = aux->monitor;
1062     struct ovsdb_table *table = new ? new->table : old->table;
1063     enum ovsdb_jsonrpc_monitor_selection type;
1064     struct json *old_json, *new_json;
1065     struct json *row_json;
1066     char uuid[UUID_LEN + 1];
1067     size_t i;
1068
1069     if (!aux->mt || table != aux->mt->table) {
1070         aux->mt = shash_find_data(&m->tables, table->schema->name);
1071         aux->table_json = NULL;
1072         if (!aux->mt) {
1073             /* We don't care about rows in this table at all.  Tell the caller
1074              * to skip it.  */
1075             return false;
1076         }
1077     }
1078
1079     type = (aux->initial ? OJMS_INITIAL
1080             : !old ? OJMS_INSERT
1081             : !new ? OJMS_DELETE
1082             : OJMS_MODIFY);
1083     if (!(aux->mt->select & type)) {
1084         /* We don't care about this type of change (but do want to be called
1085          * back for changes to other rows in the same table). */
1086         return true;
1087     }
1088
1089     if (type == OJMS_MODIFY && !any_reportable_change(aux->mt, changed)) {
1090         /* Nothing of interest changed. */
1091         return true;
1092     }
1093
1094     old_json = new_json = NULL;
1095     if (type & (OJMS_DELETE | OJMS_MODIFY)) {
1096         old_json = json_object_create();
1097     }
1098     if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
1099         new_json = json_object_create();
1100     }
1101     for (i = 0; i < aux->mt->n_columns; i++) {
1102         const struct ovsdb_jsonrpc_monitor_column *c = &aux->mt->columns[i];
1103         const struct ovsdb_column *column = c->column;
1104         unsigned int idx = c->column->index;
1105
1106         if (!(type & c->select)) {
1107             /* We don't care about this type of change for this particular
1108              * column (but we will care about it for some other column). */
1109             continue;
1110         }
1111
1112         if ((type == OJMS_MODIFY && bitmap_is_set(changed, idx))
1113             || type == OJMS_DELETE) {
1114             json_object_put(old_json, column->name,
1115                             ovsdb_datum_to_json(&old->fields[idx],
1116                                                 &column->type));
1117         }
1118         if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
1119             json_object_put(new_json, column->name,
1120                             ovsdb_datum_to_json(&new->fields[idx],
1121                                                 &column->type));
1122         }
1123     }
1124
1125     /* Create JSON object for transaction overall. */
1126     if (!aux->json) {
1127         aux->json = json_object_create();
1128     }
1129
1130     /* Create JSON object for transaction on this table. */
1131     if (!aux->table_json) {
1132         aux->table_json = json_object_create();
1133         json_object_put(aux->json, aux->mt->table->schema->name,
1134                         aux->table_json);
1135     }
1136
1137     /* Create JSON object for transaction on this row. */
1138     row_json = json_object_create();
1139     if (old_json) {
1140         json_object_put(row_json, "old", old_json);
1141     }
1142     if (new_json) {
1143         json_object_put(row_json, "new", new_json);
1144     }
1145
1146     /* Add JSON row to JSON table. */
1147     snprintf(uuid, sizeof uuid,
1148              UUID_FMT, UUID_ARGS(ovsdb_row_get_uuid(new ? new : old)));
1149     json_object_put(aux->table_json, uuid, row_json);
1150
1151     return true;
1152 }
1153
1154 static void
1155 ovsdb_jsonrpc_monitor_init_aux(struct ovsdb_jsonrpc_monitor_aux *aux,
1156                                const struct ovsdb_jsonrpc_monitor *m,
1157                                bool initial)
1158 {
1159     aux->initial = initial;
1160     aux->monitor = m;
1161     aux->json = NULL;
1162     aux->mt = NULL;
1163     aux->table_json = NULL;
1164 }
1165
1166 static struct ovsdb_error *
1167 ovsdb_jsonrpc_monitor_commit(struct ovsdb_replica *replica,
1168                              const struct ovsdb_txn *txn,
1169                              bool durable OVS_UNUSED)
1170 {
1171     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1172     struct ovsdb_jsonrpc_monitor_aux aux;
1173
1174     ovsdb_jsonrpc_monitor_init_aux(&aux, m, false);
1175     ovsdb_txn_for_each_change(txn, ovsdb_jsonrpc_monitor_change_cb, &aux);
1176     if (aux.json) {
1177         struct jsonrpc_msg *msg;
1178         struct json *params;
1179
1180         params = json_array_create_2(json_clone(aux.monitor->monitor_id),
1181                                      aux.json);
1182         msg = jsonrpc_create_notify("update", params);
1183         jsonrpc_session_send(aux.monitor->session->js, msg);
1184     }
1185
1186     return NULL;
1187 }
1188
1189 static struct json *
1190 ovsdb_jsonrpc_monitor_get_initial(const struct ovsdb_jsonrpc_monitor *m)
1191 {
1192     struct ovsdb_jsonrpc_monitor_aux aux;
1193     struct shash_node *node;
1194
1195     ovsdb_jsonrpc_monitor_init_aux(&aux, m, true);
1196     SHASH_FOR_EACH (node, &m->tables) {
1197         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1198
1199         if (mt->select & OJMS_INITIAL) {
1200             struct ovsdb_row *row;
1201
1202             HMAP_FOR_EACH (row, hmap_node, &mt->table->rows) {
1203                 ovsdb_jsonrpc_monitor_change_cb(NULL, row, NULL, &aux);
1204             }
1205         }
1206     }
1207     return aux.json ? aux.json : json_object_create();
1208 }
1209
1210 static void
1211 ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *replica)
1212 {
1213     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1214     struct shash_node *node;
1215
1216     json_destroy(m->monitor_id);
1217     SHASH_FOR_EACH (node, &m->tables) {
1218         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1219         free(mt->columns);
1220         free(mt);
1221     }
1222     shash_destroy(&m->tables);
1223     hmap_remove(&m->session->monitors, &m->node);
1224     free(m);
1225 }
1226
1227 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class = {
1228     ovsdb_jsonrpc_monitor_commit,
1229     ovsdb_jsonrpc_monitor_destroy
1230 };