ovsdb/jsonrpc-server.c

   1 /* Copyright (c) 2009, 2010, 2011, 2012 Nicira, Inc.
   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 "server.h"
  34 #include "stream.h"
  35 #include "table.h"
  36 #include "timeval.h"
  37 #include "transaction.h"
  38 #include "trigger.h"
  39 #include "vlog.h"
  40
  41 VLOG_DEFINE_THIS_MODULE(ovsdb_jsonrpc_server);
  42
  43 struct ovsdb_jsonrpc_remote;
  44 struct ovsdb_jsonrpc_session;
  45
  46 /* Message rate-limiting. */
  47 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
  48
  49 /* Sessions. */
  50 static struct ovsdb_jsonrpc_session *ovsdb_jsonrpc_session_create(
  51     struct ovsdb_jsonrpc_remote *, struct jsonrpc_session *);
  52 static void ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *);
  53 static void ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *);
  54 static void ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *);
  55 static void ovsdb_jsonrpc_session_reconnect_all(struct ovsdb_jsonrpc_remote *);
  56 static void ovsdb_jsonrpc_session_set_all_options(
  57     struct ovsdb_jsonrpc_remote *, const struct ovsdb_jsonrpc_options *);
  58 static bool ovsdb_jsonrpc_session_get_status(
  59     const struct ovsdb_jsonrpc_remote *,
  60     struct ovsdb_jsonrpc_remote_status *);
  61 static void ovsdb_jsonrpc_session_unlock_all(struct ovsdb_jsonrpc_session *);
  62 static void ovsdb_jsonrpc_session_unlock__(struct ovsdb_lock_waiter *);
  63
  64 /* Triggers. */
  65 static void ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *,
  66                                          struct json *id, struct json *params);
  67 static struct ovsdb_jsonrpc_trigger *ovsdb_jsonrpc_trigger_find(
  68     struct ovsdb_jsonrpc_session *, const struct json *id, size_t hash);
  69 static void ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *);
  70 static void ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *);
  71 static void ovsdb_jsonrpc_trigger_complete_done(
  72     struct ovsdb_jsonrpc_session *);
  73
  74 /* Monitors. */
  75 static struct json *ovsdb_jsonrpc_monitor_create(
  76     struct ovsdb_jsonrpc_session *, struct json *params);
  77 static struct jsonrpc_msg *ovsdb_jsonrpc_monitor_cancel(
  78     struct ovsdb_jsonrpc_session *,
  79     struct json_array *params,
  80     const struct json *request_id);
  81 static void ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *);
  82 \f
  83 /* JSON-RPC database server. */
  84
  85 struct ovsdb_jsonrpc_server {
  86     struct ovsdb_server up;
  87     unsigned int n_sessions, max_sessions;
  88     struct shash remotes;      /* Contains "struct ovsdb_jsonrpc_remote *"s. */
  89 };
  90
  91 /* A configured remote.  This is either a passive stream listener plus a list
  92  * of the currently connected sessions, or a list of exactly one active
  93  * session. */
  94 struct ovsdb_jsonrpc_remote {
  95     struct ovsdb_jsonrpc_server *server;
  96     struct pstream *listener;   /* Listener, if passive. */
  97     struct list sessions;       /* List of "struct ovsdb_jsonrpc_session"s. */
  98 };
  99
 100 static struct ovsdb_jsonrpc_remote *ovsdb_jsonrpc_server_add_remote(
 101     struct ovsdb_jsonrpc_server *, const char *name,
 102     const struct ovsdb_jsonrpc_options *options
 103 );
 104 static void ovsdb_jsonrpc_server_del_remote(struct shash_node *);
 105
 106 struct ovsdb_jsonrpc_server *
 107 ovsdb_jsonrpc_server_create(struct ovsdb *db)
 108 {
 109     struct ovsdb_jsonrpc_server *server = xzalloc(sizeof *server);
 110     ovsdb_server_init(&server->up, db);
 111     server->max_sessions = 64;
 112     shash_init(&server->remotes);
 113     return server;
 114 }
 115
 116 void
 117 ovsdb_jsonrpc_server_destroy(struct ovsdb_jsonrpc_server *svr)
 118 {
 119     struct shash_node *node, *next;
 120
 121     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
 122         ovsdb_jsonrpc_server_del_remote(node);
 123     }
 124     shash_destroy(&svr->remotes);
 125     ovsdb_server_destroy(&svr->up);
 126     free(svr);
 127 }
 128
 129 struct ovsdb_jsonrpc_options *
 130 ovsdb_jsonrpc_default_options(const char *target)
 131 {
 132     struct ovsdb_jsonrpc_options *options = xzalloc(sizeof *options);
 133     options->max_backoff = RECONNECT_DEFAULT_MAX_BACKOFF;
 134     options->probe_interval = (stream_or_pstream_needs_probes(target)
 135                                ? RECONNECT_DEFAULT_PROBE_INTERVAL
 136                                : 0);
 137     return options;
 138 }
 139
 140 /* Sets 'svr''s current set of remotes to the names in 'new_remotes', with
 141  * options in the struct ovsdb_jsonrpc_options supplied as the data values.
 142  *
 143  * A remote is an active or passive stream connection method, e.g. "pssl:" or
 144  * "tcp:1.2.3.4". */
 145 void
 146 ovsdb_jsonrpc_server_set_remotes(struct ovsdb_jsonrpc_server *svr,
 147                                  const struct shash *new_remotes)
 148 {
 149     struct shash_node *node, *next;
 150
 151     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
 152         if (!shash_find(new_remotes, node->name)) {
 153             VLOG_INFO("%s: remote deconfigured", node->name);
 154             ovsdb_jsonrpc_server_del_remote(node);
 155         }
 156     }
 157     SHASH_FOR_EACH (node, new_remotes) {
 158         const struct ovsdb_jsonrpc_options *options = node->data;
 159         struct ovsdb_jsonrpc_remote *remote;
 160
 161         remote = shash_find_data(&svr->remotes, node->name);
 162         if (!remote) {
 163             remote = ovsdb_jsonrpc_server_add_remote(svr, node->name, options);
 164             if (!remote) {
 165                 continue;
 166             }
 167         }
 168
 169         ovsdb_jsonrpc_session_set_all_options(remote, options);
 170     }
 171 }
 172
 173 static struct ovsdb_jsonrpc_remote *
 174 ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *svr,
 175                                 const char *name,
 176                                 const struct ovsdb_jsonrpc_options *options)
 177 {
 178     struct ovsdb_jsonrpc_remote *remote;
 179     struct pstream *listener;
 180     int error;
 181
 182     error = jsonrpc_pstream_open(name, &listener, options->dscp);
 183     if (error && error != EAFNOSUPPORT) {
 184         VLOG_ERR_RL(&rl, "%s: listen failed: %s", name, strerror(error));
 185         return NULL;
 186     }
 187
 188     remote = xmalloc(sizeof *remote);
 189     remote->server = svr;
 190     remote->listener = listener;
 191     list_init(&remote->sessions);
 192     shash_add(&svr->remotes, name, remote);
 193
 194     if (!listener) {
 195         ovsdb_jsonrpc_session_create(remote, jsonrpc_session_open(name));
 196     }
 197     return remote;
 198 }
 199
 200 static void
 201 ovsdb_jsonrpc_server_del_remote(struct shash_node *node)
 202 {
 203     struct ovsdb_jsonrpc_remote *remote = node->data;
 204
 205     ovsdb_jsonrpc_session_close_all(remote);
 206     pstream_close(remote->listener);
 207     shash_delete(&remote->server->remotes, node);
 208     free(remote);
 209 }
 210
 211 /* Stores status information for the remote named 'target', which should have
 212  * been configured on 'svr' with a call to ovsdb_jsonrpc_server_set_remotes(),
 213  * into '*status'.  On success returns true, on failure (if 'svr' doesn't have
 214  * a remote named 'target' or if that remote is an inbound remote that has no
 215  * active connections) returns false.  On failure, 'status' will be zeroed.
 216  */
 217 bool
 218 ovsdb_jsonrpc_server_get_remote_status(
 219     const struct ovsdb_jsonrpc_server *svr, const char *target,
 220     struct ovsdb_jsonrpc_remote_status *status)
 221 {
 222     const struct ovsdb_jsonrpc_remote *remote;
 223
 224     memset(status, 0, sizeof *status);
 225
 226     remote = shash_find_data(&svr->remotes, target);
 227     return remote && ovsdb_jsonrpc_session_get_status(remote, status);
 228 }
 229
 230 void
 231 ovsdb_jsonrpc_server_free_remote_status(
 232     struct ovsdb_jsonrpc_remote_status *status)
 233 {
 234     free(status->locks_held);
 235     free(status->locks_waiting);
 236     free(status->locks_lost);
 237 }
 238
 239 /* Forces all of the JSON-RPC sessions managed by 'svr' to disconnect and
 240  * reconnect. */
 241 void
 242 ovsdb_jsonrpc_server_reconnect(struct ovsdb_jsonrpc_server *svr)
 243 {
 244     struct shash_node *node;
 245
 246     SHASH_FOR_EACH (node, &svr->remotes) {
 247         struct ovsdb_jsonrpc_remote *remote = node->data;
 248
 249         ovsdb_jsonrpc_session_reconnect_all(remote);
 250     }
 251 }
 252
 253 void
 254 ovsdb_jsonrpc_server_run(struct ovsdb_jsonrpc_server *svr)
 255 {
 256     struct shash_node *node;
 257
 258     SHASH_FOR_EACH (node, &svr->remotes) {
 259         struct ovsdb_jsonrpc_remote *remote = node->data;
 260
 261         if (remote->listener && svr->n_sessions < svr->max_sessions) {
 262             struct stream *stream;
 263             int error;
 264
 265             error = pstream_accept(remote->listener, &stream);
 266             if (!error) {
 267                 struct jsonrpc_session *js;
 268                 js = jsonrpc_session_open_unreliably(jsonrpc_open(stream));
 269                 ovsdb_jsonrpc_session_create(remote, js);
 270             } else if (error != EAGAIN) {
 271                 VLOG_WARN_RL(&rl, "%s: accept failed: %s",
 272                              pstream_get_name(remote->listener),
 273                              strerror(error));
 274             }
 275         }
 276
 277         ovsdb_jsonrpc_session_run_all(remote);
 278     }
 279 }
 280
 281 void
 282 ovsdb_jsonrpc_server_wait(struct ovsdb_jsonrpc_server *svr)
 283 {
 284     struct shash_node *node;
 285
 286     SHASH_FOR_EACH (node, &svr->remotes) {
 287         struct ovsdb_jsonrpc_remote *remote = node->data;
 288
 289         if (remote->listener && svr->n_sessions < svr->max_sessions) {
 290             pstream_wait(remote->listener);
 291         }
 292
 293         ovsdb_jsonrpc_session_wait_all(remote);
 294     }
 295 }
 296 \f
 297 /* JSON-RPC database server session. */
 298
 299 struct ovsdb_jsonrpc_session {
 300     struct list node;           /* Element in remote's sessions list. */
 301     struct ovsdb_session up;
 302     struct ovsdb_jsonrpc_remote *remote;
 303
 304     /* Triggers. */
 305     struct hmap triggers;       /* Hmap of "struct ovsdb_jsonrpc_trigger"s. */
 306
 307     /* Monitors. */
 308     struct hmap monitors;       /* Hmap of "struct ovsdb_jsonrpc_monitor"s. */
 309
 310     /* Network connectivity. */
 311     struct jsonrpc_session *js;  /* JSON-RPC session. */
 312     unsigned int js_seqno;       /* Last jsonrpc_session_get_seqno() value. */
 313 };
 314
 315 static void ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *);
 316 static int ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *);
 317 static void ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *);
 318 static void ovsdb_jsonrpc_session_set_options(
 319     struct ovsdb_jsonrpc_session *, const struct ovsdb_jsonrpc_options *);
 320 static void ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *,
 321                                              struct jsonrpc_msg *);
 322 static void ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *,
 323                                              struct jsonrpc_msg *);
 324
 325 static struct ovsdb_jsonrpc_session *
 326 ovsdb_jsonrpc_session_create(struct ovsdb_jsonrpc_remote *remote,
 327                              struct jsonrpc_session *js)
 328 {
 329     struct ovsdb_jsonrpc_session *s;
 330
 331     s = xzalloc(sizeof *s);
 332     ovsdb_session_init(&s->up, remote->server->up.db);
 333     s->remote = remote;
 334     list_push_back(&remote->sessions, &s->node);
 335     hmap_init(&s->triggers);
 336     hmap_init(&s->monitors);
 337     s->js = js;
 338     s->js_seqno = jsonrpc_session_get_seqno(js);
 339
 340     remote->server->n_sessions++;
 341
 342     return s;
 343 }
 344
 345 static void
 346 ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *s)
 347 {
 348     ovsdb_jsonrpc_monitor_remove_all(s);
 349     ovsdb_jsonrpc_session_unlock_all(s);
 350     jsonrpc_session_close(s->js);
 351     list_remove(&s->node);
 352     ovsdb_session_destroy(&s->up);
 353     s->remote->server->n_sessions--;
 354     ovsdb_session_destroy(&s->up);
 355     free(s);
 356 }
 357
 358 static int
 359 ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *s)
 360 {
 361     jsonrpc_session_run(s->js);
 362     if (s->js_seqno != jsonrpc_session_get_seqno(s->js)) {
 363         s->js_seqno = jsonrpc_session_get_seqno(s->js);
 364         ovsdb_jsonrpc_trigger_complete_all(s);
 365         ovsdb_jsonrpc_monitor_remove_all(s);
 366         ovsdb_jsonrpc_session_unlock_all(s);
 367     }
 368
 369     ovsdb_jsonrpc_trigger_complete_done(s);
 370
 371     if (!jsonrpc_session_get_backlog(s->js)) {
 372         struct jsonrpc_msg *msg = jsonrpc_session_recv(s->js);
 373         if (msg) {
 374             if (msg->type == JSONRPC_REQUEST) {
 375                 ovsdb_jsonrpc_session_got_request(s, msg);
 376             } else if (msg->type == JSONRPC_NOTIFY) {
 377                 ovsdb_jsonrpc_session_got_notify(s, msg);
 378             } else {
 379                 VLOG_WARN("%s: received unexpected %s message",
 380                           jsonrpc_session_get_name(s->js),
 381                           jsonrpc_msg_type_to_string(msg->type));
 382                 jsonrpc_session_force_reconnect(s->js);
 383                 jsonrpc_msg_destroy(msg);
 384             }
 385         }
 386     }
 387     return jsonrpc_session_is_alive(s->js) ? 0 : ETIMEDOUT;
 388 }
 389
 390 static void
 391 ovsdb_jsonrpc_session_set_options(struct ovsdb_jsonrpc_session *session,
 392                                   const struct ovsdb_jsonrpc_options *options)
 393 {
 394     jsonrpc_session_set_max_backoff(session->js, options->max_backoff);
 395     jsonrpc_session_set_probe_interval(session->js, options->probe_interval);
 396     jsonrpc_session_set_dscp(session->js, options->dscp);
 397 }
 398
 399 static void
 400 ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *remote)
 401 {
 402     struct ovsdb_jsonrpc_session *s, *next;
 403
 404     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
 405         int error = ovsdb_jsonrpc_session_run(s);
 406         if (error) {
 407             ovsdb_jsonrpc_session_close(s);
 408         }
 409     }
 410 }
 411
 412 static void
 413 ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *s)
 414 {
 415     jsonrpc_session_wait(s->js);
 416     if (!jsonrpc_session_get_backlog(s->js)) {
 417         jsonrpc_session_recv_wait(s->js);
 418     }
 419 }
 420
 421 static void
 422 ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *remote)
 423 {
 424     struct ovsdb_jsonrpc_session *s;
 425
 426     LIST_FOR_EACH (s, node, &remote->sessions) {
 427         ovsdb_jsonrpc_session_wait(s);
 428     }
 429 }
 430
 431 static void
 432 ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *remote)
 433 {
 434     struct ovsdb_jsonrpc_session *s, *next;
 435
 436     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
 437         ovsdb_jsonrpc_session_close(s);
 438     }
 439 }
 440
 441 /* Forces all of the JSON-RPC sessions managed by 'remote' to disconnect and
 442  * reconnect. */
 443 static void
 444 ovsdb_jsonrpc_session_reconnect_all(struct ovsdb_jsonrpc_remote *remote)
 445 {
 446     struct ovsdb_jsonrpc_session *s, *next;
 447
 448     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
 449         jsonrpc_session_force_reconnect(s->js);
 450         if (!jsonrpc_session_is_alive(s->js)) {
 451             ovsdb_jsonrpc_session_close(s);
 452         }
 453     }
 454 }
 455
 456 /* Sets the options for all of the JSON-RPC sessions managed by 'remote' to
 457  * 'options'. */
 458 static void
 459 ovsdb_jsonrpc_session_set_all_options(
 460     struct ovsdb_jsonrpc_remote *remote,
 461     const struct ovsdb_jsonrpc_options *options)
 462 {
 463     struct ovsdb_jsonrpc_session *s;
 464
 465     LIST_FOR_EACH (s, node, &remote->sessions) {
 466         ovsdb_jsonrpc_session_set_options(s, options);
 467     }
 468 }
 469
 470 static bool
 471 ovsdb_jsonrpc_session_get_status(const struct ovsdb_jsonrpc_remote *remote,
 472                                  struct ovsdb_jsonrpc_remote_status *status)
 473 {
 474     const struct ovsdb_jsonrpc_session *s;
 475     const struct jsonrpc_session *js;
 476     struct ovsdb_lock_waiter *waiter;
 477     struct reconnect_stats rstats;
 478     struct ds locks_held, locks_waiting, locks_lost;
 479
 480     if (list_is_empty(&remote->sessions)) {
 481         return false;
 482     }
 483     s = CONTAINER_OF(remote->sessions.next, struct ovsdb_jsonrpc_session, node);
 484     js = s->js;
 485
 486     status->is_connected = jsonrpc_session_is_connected(js);
 487     status->last_error = jsonrpc_session_get_status(js);
 488
 489     jsonrpc_session_get_reconnect_stats(js, &rstats);
 490     status->state = rstats.state;
 491     status->sec_since_connect = rstats.msec_since_connect == UINT_MAX
 492         ? UINT_MAX : rstats.msec_since_connect / 1000;
 493     status->sec_since_disconnect = rstats.msec_since_disconnect == UINT_MAX
 494         ? UINT_MAX : rstats.msec_since_disconnect / 1000;
 495
 496     ds_init(&locks_held);
 497     ds_init(&locks_waiting);
 498     ds_init(&locks_lost);
 499     HMAP_FOR_EACH (waiter, session_node, &s->up.waiters) {
 500         struct ds *string;
 501
 502         string = (ovsdb_lock_waiter_is_owner(waiter) ? &locks_held
 503                   : waiter->mode == OVSDB_LOCK_WAIT ? &locks_waiting
 504                   : &locks_lost);
 505         if (string->length) {
 506             ds_put_char(string, ' ');
 507         }
 508         ds_put_cstr(string, waiter->lock_name);
 509     }
 510     status->locks_held = ds_steal_cstr(&locks_held);
 511     status->locks_waiting = ds_steal_cstr(&locks_waiting);
 512     status->locks_lost = ds_steal_cstr(&locks_lost);
 513
 514     status->n_connections = list_size(&remote->sessions);
 515
 516     return true;
 517 }
 518
 519 static const char *
 520 get_db_name(const struct ovsdb_jsonrpc_session *s)
 521 {
 522     return s->remote->server->up.db->schema->name;
 523 }
 524
 525 static struct jsonrpc_msg *
 526 ovsdb_jsonrpc_check_db_name(const struct ovsdb_jsonrpc_session *s,
 527                             const struct jsonrpc_msg *request)
 528 {
 529     struct json_array *params;
 530     const char *want_db_name;
 531     const char *have_db_name;
 532     struct ovsdb_error *error;
 533     struct jsonrpc_msg *reply;
 534
 535     params = json_array(request->params);
 536     if (!params->n || params->elems[0]->type != JSON_STRING) {
 537         error = ovsdb_syntax_error(
 538             request->params, NULL,
 539             "%s request params must begin with <db-name>", request->method);
 540         goto error;
 541     }
 542
 543     want_db_name = params->elems[0]->u.string;
 544     have_db_name = get_db_name(s);
 545     if (strcmp(want_db_name, have_db_name)) {
 546         error = ovsdb_syntax_error(
 547             request->params, "unknown database",
 548             "%s request specifies unknown database %s",
 549             request->method, want_db_name);
 550         goto error;
 551     }
 552
 553     return NULL;
 554
 555 error:
 556     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
 557     ovsdb_error_destroy(error);
 558     return reply;
 559 }
 560
 561 static struct ovsdb_error *
 562 ovsdb_jsonrpc_session_parse_lock_name(const struct jsonrpc_msg *request,
 563                                       const char **lock_namep)
 564 {
 565     const struct json_array *params;
 566
 567     params = json_array(request->params);
 568     if (params->n != 1 || params->elems[0]->type != JSON_STRING ||
 569         !ovsdb_parser_is_id(json_string(params->elems[0]))) {
 570         *lock_namep = NULL;
 571         return ovsdb_syntax_error(request->params, NULL,
 572                                   "%s request params must be <id>",
 573                                   request->method);
 574     }
 575
 576     *lock_namep = json_string(params->elems[0]);
 577     return NULL;
 578 }
 579
 580 static void
 581 ovsdb_jsonrpc_session_notify(struct ovsdb_session *session,
 582                              const char *lock_name,
 583                              const char *method)
 584 {
 585     struct ovsdb_jsonrpc_session *s;
 586     struct json *params;
 587
 588     s = CONTAINER_OF(session, struct ovsdb_jsonrpc_session, up);
 589     params = json_array_create_1(json_string_create(lock_name));
 590     jsonrpc_session_send(s->js, jsonrpc_create_notify(method, params));
 591 }
 592
 593 static struct jsonrpc_msg *
 594 ovsdb_jsonrpc_session_lock(struct ovsdb_jsonrpc_session *s,
 595                            struct jsonrpc_msg *request,
 596                            enum ovsdb_lock_mode mode)
 597 {
 598     struct ovsdb_lock_waiter *waiter;
 599     struct jsonrpc_msg *reply;
 600     struct ovsdb_error *error;
 601     struct ovsdb_session *victim;
 602     const char *lock_name;
 603     struct json *result;
 604
 605     error = ovsdb_jsonrpc_session_parse_lock_name(request, &lock_name);
 606     if (error) {
 607         goto error;
 608     }
 609
 610     /* Report error if this session has issued a "lock" or "steal" without a
 611      * matching "unlock" for this lock. */
 612     waiter = ovsdb_session_get_lock_waiter(&s->up, lock_name);
 613     if (waiter) {
 614         error = ovsdb_syntax_error(
 615             request->params, NULL,
 616             "must issue \"unlock\" before new \"%s\"", request->method);
 617         goto error;
 618     }
 619
 620     /* Get the lock, add us as a waiter. */
 621     waiter = ovsdb_server_lock(&s->remote->server->up, &s->up, lock_name, mode,
 622                                &victim);
 623     if (victim) {
 624         ovsdb_jsonrpc_session_notify(victim, lock_name, "stolen");
 625     }
 626
 627     result = json_object_create();
 628     json_object_put(result, "locked",
 629                     json_boolean_create(ovsdb_lock_waiter_is_owner(waiter)));
 630
 631     return jsonrpc_create_reply(result, request->id);
 632
 633 error:
 634     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
 635     ovsdb_error_destroy(error);
 636     return reply;
 637 }
 638
 639 static void
 640 ovsdb_jsonrpc_session_unlock_all(struct ovsdb_jsonrpc_session *s)
 641 {
 642     struct ovsdb_lock_waiter *waiter, *next;
 643
 644     HMAP_FOR_EACH_SAFE (waiter, next, session_node, &s->up.waiters) {
 645         ovsdb_jsonrpc_session_unlock__(waiter);
 646     }
 647 }
 648
 649 static void
 650 ovsdb_jsonrpc_session_unlock__(struct ovsdb_lock_waiter *waiter)
 651 {
 652     struct ovsdb_lock *lock = waiter->lock;
 653
 654     if (lock) {
 655         struct ovsdb_session *new_owner = ovsdb_lock_waiter_remove(waiter);
 656         if (new_owner) {
 657             ovsdb_jsonrpc_session_notify(new_owner, lock->name, "locked");
 658         } else {
 659             /* ovsdb_server_lock() might have freed 'lock'. */
 660         }
 661     }
 662
 663     ovsdb_lock_waiter_destroy(waiter);
 664 }
 665
 666 static struct jsonrpc_msg *
 667 ovsdb_jsonrpc_session_unlock(struct ovsdb_jsonrpc_session *s,
 668                              struct jsonrpc_msg *request)
 669 {
 670     struct ovsdb_lock_waiter *waiter;
 671     struct jsonrpc_msg *reply;
 672     struct ovsdb_error *error;
 673     const char *lock_name;
 674
 675     error = ovsdb_jsonrpc_session_parse_lock_name(request, &lock_name);
 676     if (error) {
 677         goto error;
 678     }
 679
 680     /* Report error if this session has not issued a "lock" or "steal" for this
 681      * lock. */
 682     waiter = ovsdb_session_get_lock_waiter(&s->up, lock_name);
 683     if (!waiter) {
 684         error = ovsdb_syntax_error(
 685             request->params, NULL, "\"unlock\" without \"lock\" or \"steal\"");
 686         goto error;
 687     }
 688
 689     ovsdb_jsonrpc_session_unlock__(waiter);
 690
 691     return jsonrpc_create_reply(json_object_create(), request->id);
 692
 693 error:
 694     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
 695     ovsdb_error_destroy(error);
 696     return reply;
 697 }
 698
 699 static struct jsonrpc_msg *
 700 execute_transaction(struct ovsdb_jsonrpc_session *s,
 701                     struct jsonrpc_msg *request)
 702 {
 703     ovsdb_jsonrpc_trigger_create(s, request->id, request->params);
 704     request->id = NULL;
 705     request->params = NULL;
 706     jsonrpc_msg_destroy(request);
 707     return NULL;
 708 }
 709
 710 static void
 711 ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *s,
 712                                   struct jsonrpc_msg *request)
 713 {
 714     struct jsonrpc_msg *reply;
 715
 716     if (!strcmp(request->method, "transact")) {
 717         reply = ovsdb_jsonrpc_check_db_name(s, request);
 718         if (!reply) {
 719             reply = execute_transaction(s, request);
 720         }
 721     } else if (!strcmp(request->method, "monitor")) {
 722         reply = ovsdb_jsonrpc_check_db_name(s, request);
 723         if (!reply) {
 724             reply = jsonrpc_create_reply(
 725                 ovsdb_jsonrpc_monitor_create(s, request->params), request->id);
 726         }
 727     } else if (!strcmp(request->method, "monitor_cancel")) {
 728         reply = ovsdb_jsonrpc_monitor_cancel(s, json_array(request->params),
 729                                              request->id);
 730     } else if (!strcmp(request->method, "get_schema")) {
 731         reply = ovsdb_jsonrpc_check_db_name(s, request);
 732         if (!reply) {
 733             reply = jsonrpc_create_reply(
 734                 ovsdb_schema_to_json(s->remote->server->up.db->schema),
 735                 request->id);
 736         }
 737     } else if (!strcmp(request->method, "list_dbs")) {
 738         reply = jsonrpc_create_reply(
 739             json_array_create_1(json_string_create(get_db_name(s))),
 740             request->id);
 741     } else if (!strcmp(request->method, "lock")) {
 742         reply = ovsdb_jsonrpc_session_lock(s, request, OVSDB_LOCK_WAIT);
 743     } else if (!strcmp(request->method, "steal")) {
 744         reply = ovsdb_jsonrpc_session_lock(s, request, OVSDB_LOCK_STEAL);
 745     } else if (!strcmp(request->method, "unlock")) {
 746         reply = ovsdb_jsonrpc_session_unlock(s, request);
 747     } else if (!strcmp(request->method, "echo")) {
 748         reply = jsonrpc_create_reply(json_clone(request->params), request->id);
 749     } else {
 750         reply = jsonrpc_create_error(json_string_create("unknown method"),
 751                                      request->id);
 752     }
 753
 754     if (reply) {
 755         jsonrpc_msg_destroy(request);
 756         jsonrpc_session_send(s->js, reply);
 757     }
 758 }
 759
 760 static void
 761 execute_cancel(struct ovsdb_jsonrpc_session *s, struct jsonrpc_msg *request)
 762 {
 763     if (json_array(request->params)->n == 1) {
 764         struct ovsdb_jsonrpc_trigger *t;
 765         struct json *id;
 766
 767         id = request->params->u.array.elems[0];
 768         t = ovsdb_jsonrpc_trigger_find(s, id, json_hash(id, 0));
 769         if (t) {
 770             ovsdb_jsonrpc_trigger_complete(t);
 771         }
 772     }
 773 }
 774
 775 static void
 776 ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *s,
 777                                  struct jsonrpc_msg *request)
 778 {
 779     if (!strcmp(request->method, "cancel")) {
 780         execute_cancel(s, request);
 781     }
 782     jsonrpc_msg_destroy(request);
 783 }
 784 \f
 785 /* JSON-RPC database server triggers.
 786  *
 787  * (Every transaction is treated as a trigger even if it doesn't actually have
 788  * any "wait" operations.) */
 789
 790 struct ovsdb_jsonrpc_trigger {
 791     struct ovsdb_trigger trigger;
 792     struct hmap_node hmap_node; /* In session's "triggers" hmap. */
 793     struct json *id;
 794 };
 795
 796 static void
 797 ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *s,
 798                              struct json *id, struct json *params)
 799 {
 800     struct ovsdb_jsonrpc_trigger *t;
 801     size_t hash;
 802
 803     /* Check for duplicate ID. */
 804     hash = json_hash(id, 0);
 805     t = ovsdb_jsonrpc_trigger_find(s, id, hash);
 806     if (t) {
 807         struct jsonrpc_msg *msg;
 808
 809         msg = jsonrpc_create_error(json_string_create("duplicate request ID"),
 810                                    id);
 811         jsonrpc_session_send(s->js, msg);
 812         json_destroy(id);
 813         json_destroy(params);
 814         return;
 815     }
 816
 817     /* Insert into trigger table. */
 818     t = xmalloc(sizeof *t);
 819     ovsdb_trigger_init(&s->up, &t->trigger, params, time_msec());
 820     t->id = id;
 821     hmap_insert(&s->triggers, &t->hmap_node, hash);
 822
 823     /* Complete early if possible. */
 824     if (ovsdb_trigger_is_complete(&t->trigger)) {
 825         ovsdb_jsonrpc_trigger_complete(t);
 826     }
 827 }
 828
 829 static struct ovsdb_jsonrpc_trigger *
 830 ovsdb_jsonrpc_trigger_find(struct ovsdb_jsonrpc_session *s,
 831                            const struct json *id, size_t hash)
 832 {
 833     struct ovsdb_jsonrpc_trigger *t;
 834
 835     HMAP_FOR_EACH_WITH_HASH (t, hmap_node, hash, &s->triggers) {
 836         if (json_equal(t->id, id)) {
 837             return t;
 838         }
 839     }
 840
 841     return NULL;
 842 }
 843
 844 static void
 845 ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *t)
 846 {
 847     struct ovsdb_jsonrpc_session *s;
 848
 849     s = CONTAINER_OF(t->trigger.session, struct ovsdb_jsonrpc_session, up);
 850
 851     if (jsonrpc_session_is_connected(s->js)) {
 852         struct jsonrpc_msg *reply;
 853         struct json *result;
 854
 855         result = ovsdb_trigger_steal_result(&t->trigger);
 856         if (result) {
 857             reply = jsonrpc_create_reply(result, t->id);
 858         } else {
 859             reply = jsonrpc_create_error(json_string_create("canceled"),
 860                                          t->id);
 861         }
 862         jsonrpc_session_send(s->js, reply);
 863     }
 864
 865     json_destroy(t->id);
 866     ovsdb_trigger_destroy(&t->trigger);
 867     hmap_remove(&s->triggers, &t->hmap_node);
 868     free(t);
 869 }
 870
 871 static void
 872 ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *s)
 873 {
 874     struct ovsdb_jsonrpc_trigger *t, *next;
 875     HMAP_FOR_EACH_SAFE (t, next, hmap_node, &s->triggers) {
 876         ovsdb_jsonrpc_trigger_complete(t);
 877     }
 878 }
 879
 880 static void
 881 ovsdb_jsonrpc_trigger_complete_done(struct ovsdb_jsonrpc_session *s)
 882 {
 883     while (!list_is_empty(&s->up.completions)) {
 884         struct ovsdb_jsonrpc_trigger *t
 885             = CONTAINER_OF(s->up.completions.next,
 886                            struct ovsdb_jsonrpc_trigger, trigger.node);
 887         ovsdb_jsonrpc_trigger_complete(t);
 888     }
 889 }
 890 \f
 891 /* JSON-RPC database table monitors. */
 892
 893 enum ovsdb_jsonrpc_monitor_selection {
 894     OJMS_INITIAL = 1 << 0,      /* All rows when monitor is created. */
 895     OJMS_INSERT = 1 << 1,       /* New rows. */
 896     OJMS_DELETE = 1 << 2,       /* Deleted rows. */
 897     OJMS_MODIFY = 1 << 3        /* Modified rows. */
 898 };
 899
 900 /* A particular column being monitored. */
 901 struct ovsdb_jsonrpc_monitor_column {
 902     const struct ovsdb_column *column;
 903     enum ovsdb_jsonrpc_monitor_selection select;
 904 };
 905
 906 /* A particular table being monitored. */
 907 struct ovsdb_jsonrpc_monitor_table {
 908     const struct ovsdb_table *table;
 909
 910     /* This is the union (bitwise-OR) of the 'select' values in all of the
 911      * members of 'columns' below. */
 912     enum ovsdb_jsonrpc_monitor_selection select;
 913
 914     /* Columns being monitored. */
 915     struct ovsdb_jsonrpc_monitor_column *columns;
 916     size_t n_columns;
 917 };
 918
 919 /* A collection of tables being monitored. */
 920 struct ovsdb_jsonrpc_monitor {
 921     struct ovsdb_replica replica;
 922     struct ovsdb_jsonrpc_session *session;
 923     struct hmap_node node;      /* In ovsdb_jsonrpc_session's "monitors". */
 924
 925     struct json *monitor_id;
 926     struct shash tables;     /* Holds "struct ovsdb_jsonrpc_monitor_table"s. */
 927 };
 928
 929 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class;
 930
 931 struct ovsdb_jsonrpc_monitor *ovsdb_jsonrpc_monitor_find(
 932     struct ovsdb_jsonrpc_session *, const struct json *monitor_id);
 933 static void ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *);
 934 static struct json *ovsdb_jsonrpc_monitor_get_initial(
 935     const struct ovsdb_jsonrpc_monitor *);
 936
 937 static bool
 938 parse_bool(struct ovsdb_parser *parser, const char *name, bool default_value)
 939 {
 940     const struct json *json;
 941
 942     json = ovsdb_parser_member(parser, name, OP_BOOLEAN | OP_OPTIONAL);
 943     return json ? json_boolean(json) : default_value;
 944 }
 945
 946 struct ovsdb_jsonrpc_monitor *
 947 ovsdb_jsonrpc_monitor_find(struct ovsdb_jsonrpc_session *s,
 948                            const struct json *monitor_id)
 949 {
 950     struct ovsdb_jsonrpc_monitor *m;
 951
 952     HMAP_FOR_EACH_WITH_HASH (m, node, json_hash(monitor_id, 0), &s->monitors) {
 953         if (json_equal(m->monitor_id, monitor_id)) {
 954             return m;
 955         }
 956     }
 957
 958     return NULL;
 959 }
 960
 961 static void
 962 ovsdb_jsonrpc_add_monitor_column(struct ovsdb_jsonrpc_monitor_table *mt,
 963                                  const struct ovsdb_column *column,
 964                                  enum ovsdb_jsonrpc_monitor_selection select,
 965                                  size_t *allocated_columns)
 966 {
 967     struct ovsdb_jsonrpc_monitor_column *c;
 968
 969     if (mt->n_columns >= *allocated_columns) {
 970         mt->columns = x2nrealloc(mt->columns, allocated_columns,
 971                                  sizeof *mt->columns);
 972     }
 973
 974     c = &mt->columns[mt->n_columns++];
 975     c->column = column;
 976     c->select = select;
 977 }
 978
 979 static int
 980 compare_ovsdb_jsonrpc_monitor_column(const void *a_, const void *b_)
 981 {
 982     const struct ovsdb_jsonrpc_monitor_column *a = a_;
 983     const struct ovsdb_jsonrpc_monitor_column *b = b_;
 984
 985     return a->column < b->column ? -1 : a->column > b->column;
 986 }
 987
 988 static struct ovsdb_error * WARN_UNUSED_RESULT
 989 ovsdb_jsonrpc_parse_monitor_request(struct ovsdb_jsonrpc_monitor_table *mt,
 990                                     const struct json *monitor_request,
 991                                     size_t *allocated_columns)
 992 {
 993     const struct ovsdb_table_schema *ts = mt->table->schema;
 994     enum ovsdb_jsonrpc_monitor_selection select;
 995     const struct json *columns, *select_json;
 996     struct ovsdb_parser parser;
 997     struct ovsdb_error *error;
 998
 999     ovsdb_parser_init(&parser, monitor_request, "table %s", ts->name);
1000     columns = ovsdb_parser_member(&parser, "columns", OP_ARRAY | OP_OPTIONAL);
1001     select_json = ovsdb_parser_member(&parser, "select",
1002                                       OP_OBJECT | OP_OPTIONAL);
1003     error = ovsdb_parser_finish(&parser);
1004     if (error) {
1005         return error;
1006     }
1007
1008     if (select_json) {
1009         select = 0;
1010         ovsdb_parser_init(&parser, select_json, "table %s select", ts->name);
1011         if (parse_bool(&parser, "initial", true)) {
1012             select |= OJMS_INITIAL;
1013         }
1014         if (parse_bool(&parser, "insert", true)) {
1015             select |= OJMS_INSERT;
1016         }
1017         if (parse_bool(&parser, "delete", true)) {
1018             select |= OJMS_DELETE;
1019         }
1020         if (parse_bool(&parser, "modify", true)) {
1021             select |= OJMS_MODIFY;
1022         }
1023         error = ovsdb_parser_finish(&parser);
1024         if (error) {
1025             return error;
1026         }
1027     } else {
1028         select = OJMS_INITIAL | OJMS_INSERT | OJMS_DELETE | OJMS_MODIFY;
1029     }
1030     mt->select |= select;
1031
1032     if (columns) {
1033         size_t i;
1034
1035         if (columns->type != JSON_ARRAY) {
1036             return ovsdb_syntax_error(columns, NULL,
1037                                       "array of column names expected");
1038         }
1039
1040         for (i = 0; i < columns->u.array.n; i++) {
1041             const struct ovsdb_column *column;
1042             const char *s;
1043
1044             if (columns->u.array.elems[i]->type != JSON_STRING) {
1045                 return ovsdb_syntax_error(columns, NULL,
1046                                           "array of column names expected");
1047             }
1048
1049             s = columns->u.array.elems[i]->u.string;
1050             column = shash_find_data(&mt->table->schema->columns, s);
1051             if (!column) {
1052                 return ovsdb_syntax_error(columns, NULL, "%s is not a valid "
1053                                           "column name", s);
1054             }
1055             ovsdb_jsonrpc_add_monitor_column(mt, column, select,
1056                                              allocated_columns);
1057         }
1058     } else {
1059         struct shash_node *node;
1060
1061         SHASH_FOR_EACH (node, &ts->columns) {
1062             const struct ovsdb_column *column = node->data;
1063             if (column->index != OVSDB_COL_UUID) {
1064                 ovsdb_jsonrpc_add_monitor_column(mt, column, select,
1065                                                  allocated_columns);
1066             }
1067         }
1068     }
1069
1070     return NULL;
1071 }
1072
1073 static struct json *
1074 ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s,
1075                              struct json *params)
1076 {
1077     struct ovsdb_jsonrpc_monitor *m = NULL;
1078     struct json *monitor_id, *monitor_requests;
1079     struct ovsdb_error *error = NULL;
1080     struct shash_node *node;
1081     struct json *json;
1082
1083     if (json_array(params)->n != 3) {
1084         error = ovsdb_syntax_error(params, NULL, "invalid parameters");
1085         goto error;
1086     }
1087     monitor_id = params->u.array.elems[1];
1088     monitor_requests = params->u.array.elems[2];
1089     if (monitor_requests->type != JSON_OBJECT) {
1090         error = ovsdb_syntax_error(monitor_requests, NULL,
1091                                    "monitor-requests must be object");
1092         goto error;
1093     }
1094
1095     if (ovsdb_jsonrpc_monitor_find(s, monitor_id)) {
1096         error = ovsdb_syntax_error(monitor_id, NULL, "duplicate monitor ID");
1097         goto error;
1098     }
1099
1100     m = xzalloc(sizeof *m);
1101     ovsdb_replica_init(&m->replica, &ovsdb_jsonrpc_replica_class);
1102     ovsdb_add_replica(s->remote->server->up.db, &m->replica);
1103     m->session = s;
1104     hmap_insert(&s->monitors, &m->node, json_hash(monitor_id, 0));
1105     m->monitor_id = json_clone(monitor_id);
1106     shash_init(&m->tables);
1107
1108     SHASH_FOR_EACH (node, json_object(monitor_requests)) {
1109         const struct ovsdb_table *table;
1110         struct ovsdb_jsonrpc_monitor_table *mt;
1111         size_t allocated_columns;
1112         const struct json *mr_value;
1113         size_t i;
1114
1115         table = ovsdb_get_table(s->remote->server->up.db, node->name);
1116         if (!table) {
1117             error = ovsdb_syntax_error(NULL, NULL,
1118                                        "no table named %s", node->name);
1119             goto error;
1120         }
1121
1122         mt = xzalloc(sizeof *mt);
1123         mt->table = table;
1124         shash_add(&m->tables, table->schema->name, mt);
1125
1126         /* Parse columns. */
1127         mr_value = node->data;
1128         allocated_columns = 0;
1129         if (mr_value->type == JSON_ARRAY) {
1130             const struct json_array *array = &mr_value->u.array;
1131
1132             for (i = 0; i < array->n; i++) {
1133                 error = ovsdb_jsonrpc_parse_monitor_request(
1134                     mt, array->elems[i], &allocated_columns);
1135                 if (error) {
1136                     goto error;
1137                 }
1138             }
1139         } else {
1140             error = ovsdb_jsonrpc_parse_monitor_request(
1141                 mt, mr_value, &allocated_columns);
1142             if (error) {
1143                 goto error;
1144             }
1145         }
1146
1147         /* Check for duplicate columns. */
1148         qsort(mt->columns, mt->n_columns, sizeof *mt->columns,
1149               compare_ovsdb_jsonrpc_monitor_column);
1150         for (i = 1; i < mt->n_columns; i++) {
1151             if (mt->columns[i].column == mt->columns[i - 1].column) {
1152                 error = ovsdb_syntax_error(mr_value, NULL, "column %s "
1153                                            "mentioned more than once",
1154                                            mt->columns[i].column->name);
1155                 goto error;
1156             }
1157         }
1158     }
1159
1160     return ovsdb_jsonrpc_monitor_get_initial(m);
1161
1162 error:
1163     if (m) {
1164         ovsdb_remove_replica(s->remote->server->up.db, &m->replica);
1165     }
1166
1167     json = ovsdb_error_to_json(error);
1168     ovsdb_error_destroy(error);
1169     return json;
1170 }
1171
1172 static struct jsonrpc_msg *
1173 ovsdb_jsonrpc_monitor_cancel(struct ovsdb_jsonrpc_session *s,
1174                              struct json_array *params,
1175                              const struct json *request_id)
1176 {
1177     if (params->n != 1) {
1178         return jsonrpc_create_error(json_string_create("invalid parameters"),
1179                                     request_id);
1180     } else {
1181         struct ovsdb_jsonrpc_monitor *m;
1182
1183         m = ovsdb_jsonrpc_monitor_find(s, params->elems[0]);
1184         if (!m) {
1185             return jsonrpc_create_error(json_string_create("unknown monitor"),
1186                                         request_id);
1187         } else {
1188             ovsdb_remove_replica(s->remote->server->up.db, &m->replica);
1189             return jsonrpc_create_reply(json_object_create(), request_id);
1190         }
1191     }
1192 }
1193
1194 static void
1195 ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *s)
1196 {
1197     struct ovsdb_jsonrpc_monitor *m, *next;
1198
1199     HMAP_FOR_EACH_SAFE (m, next, node, &s->monitors) {
1200         ovsdb_remove_replica(s->remote->server->up.db, &m->replica);
1201     }
1202 }
1203
1204 static struct ovsdb_jsonrpc_monitor *
1205 ovsdb_jsonrpc_monitor_cast(struct ovsdb_replica *replica)
1206 {
1207     assert(replica->class == &ovsdb_jsonrpc_replica_class);
1208     return CONTAINER_OF(replica, struct ovsdb_jsonrpc_monitor, replica);
1209 }
1210
1211 struct ovsdb_jsonrpc_monitor_aux {
1212     bool initial;               /* Sending initial contents of table? */
1213     const struct ovsdb_jsonrpc_monitor *monitor;
1214     struct json *json;          /* JSON for the whole transaction. */
1215
1216     /* Current table.  */
1217     struct ovsdb_jsonrpc_monitor_table *mt;
1218     struct json *table_json;    /* JSON for table's transaction. */
1219 };
1220
1221 static bool
1222 any_reportable_change(const struct ovsdb_jsonrpc_monitor_table *mt,
1223                       const unsigned long int *changed)
1224 {
1225     size_t i;
1226
1227     for (i = 0; i < mt->n_columns; i++) {
1228         const struct ovsdb_jsonrpc_monitor_column *c = &mt->columns[i];
1229         unsigned int idx = c->column->index;
1230
1231         if (c->select & OJMS_MODIFY && bitmap_is_set(changed, idx)) {
1232             return true;
1233         }
1234     }
1235
1236     return false;
1237 }
1238
1239 static bool
1240 ovsdb_jsonrpc_monitor_change_cb(const struct ovsdb_row *old,
1241                                 const struct ovsdb_row *new,
1242                                 const unsigned long int *changed,
1243                                 void *aux_)
1244 {
1245     struct ovsdb_jsonrpc_monitor_aux *aux = aux_;
1246     const struct ovsdb_jsonrpc_monitor *m = aux->monitor;
1247     struct ovsdb_table *table = new ? new->table : old->table;
1248     enum ovsdb_jsonrpc_monitor_selection type;
1249     struct json *old_json, *new_json;
1250     struct json *row_json;
1251     char uuid[UUID_LEN + 1];
1252     size_t i;
1253
1254     if (!aux->mt || table != aux->mt->table) {
1255         aux->mt = shash_find_data(&m->tables, table->schema->name);
1256         aux->table_json = NULL;
1257         if (!aux->mt) {
1258             /* We don't care about rows in this table at all.  Tell the caller
1259              * to skip it.  */
1260             return false;
1261         }
1262     }
1263
1264     type = (aux->initial ? OJMS_INITIAL
1265             : !old ? OJMS_INSERT
1266             : !new ? OJMS_DELETE
1267             : OJMS_MODIFY);
1268     if (!(aux->mt->select & type)) {
1269         /* We don't care about this type of change (but do want to be called
1270          * back for changes to other rows in the same table). */
1271         return true;
1272     }
1273
1274     if (type == OJMS_MODIFY && !any_reportable_change(aux->mt, changed)) {
1275         /* Nothing of interest changed. */
1276         return true;
1277     }
1278
1279     old_json = new_json = NULL;
1280     if (type & (OJMS_DELETE | OJMS_MODIFY)) {
1281         old_json = json_object_create();
1282     }
1283     if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
1284         new_json = json_object_create();
1285     }
1286     for (i = 0; i < aux->mt->n_columns; i++) {
1287         const struct ovsdb_jsonrpc_monitor_column *c = &aux->mt->columns[i];
1288         const struct ovsdb_column *column = c->column;
1289         unsigned int idx = c->column->index;
1290
1291         if (!(type & c->select)) {
1292             /* We don't care about this type of change for this particular
1293              * column (but we will care about it for some other column). */
1294             continue;
1295         }
1296
1297         if ((type == OJMS_MODIFY && bitmap_is_set(changed, idx))
1298             || type == OJMS_DELETE) {
1299             json_object_put(old_json, column->name,
1300                             ovsdb_datum_to_json(&old->fields[idx],
1301                                                 &column->type));
1302         }
1303         if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
1304             json_object_put(new_json, column->name,
1305                             ovsdb_datum_to_json(&new->fields[idx],
1306                                                 &column->type));
1307         }
1308     }
1309
1310     /* Create JSON object for transaction overall. */
1311     if (!aux->json) {
1312         aux->json = json_object_create();
1313     }
1314
1315     /* Create JSON object for transaction on this table. */
1316     if (!aux->table_json) {
1317         aux->table_json = json_object_create();
1318         json_object_put(aux->json, aux->mt->table->schema->name,
1319                         aux->table_json);
1320     }
1321
1322     /* Create JSON object for transaction on this row. */
1323     row_json = json_object_create();
1324     if (old_json) {
1325         json_object_put(row_json, "old", old_json);
1326     }
1327     if (new_json) {
1328         json_object_put(row_json, "new", new_json);
1329     }
1330
1331     /* Add JSON row to JSON table. */
1332     snprintf(uuid, sizeof uuid,
1333              UUID_FMT, UUID_ARGS(ovsdb_row_get_uuid(new ? new : old)));
1334     json_object_put(aux->table_json, uuid, row_json);
1335
1336     return true;
1337 }
1338
1339 static void
1340 ovsdb_jsonrpc_monitor_init_aux(struct ovsdb_jsonrpc_monitor_aux *aux,
1341                                const struct ovsdb_jsonrpc_monitor *m,
1342                                bool initial)
1343 {
1344     aux->initial = initial;
1345     aux->monitor = m;
1346     aux->json = NULL;
1347     aux->mt = NULL;
1348     aux->table_json = NULL;
1349 }
1350
1351 static struct ovsdb_error *
1352 ovsdb_jsonrpc_monitor_commit(struct ovsdb_replica *replica,
1353                              const struct ovsdb_txn *txn,
1354                              bool durable OVS_UNUSED)
1355 {
1356     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1357     struct ovsdb_jsonrpc_monitor_aux aux;
1358
1359     ovsdb_jsonrpc_monitor_init_aux(&aux, m, false);
1360     ovsdb_txn_for_each_change(txn, ovsdb_jsonrpc_monitor_change_cb, &aux);
1361     if (aux.json) {
1362         struct jsonrpc_msg *msg;
1363         struct json *params;
1364
1365         params = json_array_create_2(json_clone(aux.monitor->monitor_id),
1366                                      aux.json);
1367         msg = jsonrpc_create_notify("update", params);
1368         jsonrpc_session_send(aux.monitor->session->js, msg);
1369     }
1370
1371     return NULL;
1372 }
1373
1374 static struct json *
1375 ovsdb_jsonrpc_monitor_get_initial(const struct ovsdb_jsonrpc_monitor *m)
1376 {
1377     struct ovsdb_jsonrpc_monitor_aux aux;
1378     struct shash_node *node;
1379
1380     ovsdb_jsonrpc_monitor_init_aux(&aux, m, true);
1381     SHASH_FOR_EACH (node, &m->tables) {
1382         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1383
1384         if (mt->select & OJMS_INITIAL) {
1385             struct ovsdb_row *row;
1386
1387             HMAP_FOR_EACH (row, hmap_node, &mt->table->rows) {
1388                 ovsdb_jsonrpc_monitor_change_cb(NULL, row, NULL, &aux);
1389             }
1390         }
1391     }
1392     return aux.json ? aux.json : json_object_create();
1393 }
1394
1395 static void
1396 ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *replica)
1397 {
1398     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1399     struct shash_node *node;
1400
1401     json_destroy(m->monitor_id);
1402     SHASH_FOR_EACH (node, &m->tables) {
1403         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1404         free(mt->columns);
1405         free(mt);
1406     }
1407     shash_destroy(&m->tables);
1408     hmap_remove(&m->session->monitors, &m->node);
1409     free(m);
1410 }
1411
1412 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class = {
1413     ovsdb_jsonrpc_monitor_commit,
1414     ovsdb_jsonrpc_monitor_destroy
1415 };