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