pintos-os.org Git - openvswitch/blob - 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 "simap.h"
  35 #include "stream.h"
  36 #include "table.h"
  37 #include "timeval.h"
  38 #include "transaction.h"
  39 #include "trigger.h"
  40 #include "vlog.h"
  41
  42 VLOG_DEFINE_THIS_MODULE(ovsdb_jsonrpc_server);
  43
  44 struct ovsdb_jsonrpc_remote;
  45 struct ovsdb_jsonrpc_session;
  46
  47 /* Message rate-limiting. */
  48 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
  49
  50 /* Sessions. */
  51 static struct ovsdb_jsonrpc_session *ovsdb_jsonrpc_session_create(
  52     struct ovsdb_jsonrpc_remote *, struct jsonrpc_session *);
  53 static void ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *);
  54 static void ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *);
  55 static void ovsdb_jsonrpc_session_get_memory_usage_all(
  56     const struct ovsdb_jsonrpc_remote *, struct simap *usage);
  57 static void ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *);
  58 static void ovsdb_jsonrpc_session_reconnect_all(struct ovsdb_jsonrpc_remote *);
  59 static void ovsdb_jsonrpc_session_set_all_options(
  60     struct ovsdb_jsonrpc_remote *, const struct ovsdb_jsonrpc_options *);
  61 static bool ovsdb_jsonrpc_session_get_status(
  62     const struct ovsdb_jsonrpc_remote *,
  63     struct ovsdb_jsonrpc_remote_status *);
  64 static void ovsdb_jsonrpc_session_unlock_all(struct ovsdb_jsonrpc_session *);
  65 static void ovsdb_jsonrpc_session_unlock__(struct ovsdb_lock_waiter *);
  66
  67 /* Triggers. */
  68 static void ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *,
  69                                          struct json *id, struct json *params);
  70 static struct ovsdb_jsonrpc_trigger *ovsdb_jsonrpc_trigger_find(
  71     struct ovsdb_jsonrpc_session *, const struct json *id, size_t hash);
  72 static void ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *);
  73 static void ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *);
  74 static void ovsdb_jsonrpc_trigger_complete_done(
  75     struct ovsdb_jsonrpc_session *);
  76
  77 /* Monitors. */
  78 static struct json *ovsdb_jsonrpc_monitor_create(
  79     struct ovsdb_jsonrpc_session *, struct json *params);
  80 static struct jsonrpc_msg *ovsdb_jsonrpc_monitor_cancel(
  81     struct ovsdb_jsonrpc_session *,
  82     struct json_array *params,
  83     const struct json *request_id);
  84 static void ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *);
  85 \f
  86 /* JSON-RPC database server. */
  87
  88 struct ovsdb_jsonrpc_server {
  89     struct ovsdb_server up;
  90     unsigned int n_sessions, max_sessions;
  91     struct shash remotes;      /* Contains "struct ovsdb_jsonrpc_remote *"s. */
  92 };
  93
  94 /* A configured remote.  This is either a passive stream listener plus a list
  95  * of the currently connected sessions, or a list of exactly one active
  96  * session. */
  97 struct ovsdb_jsonrpc_remote {
  98     struct ovsdb_jsonrpc_server *server;
  99     struct pstream *listener;   /* Listener, if passive. */
 100     struct list sessions;       /* List of "struct ovsdb_jsonrpc_session"s. */
 101 };
 102
 103 static struct ovsdb_jsonrpc_remote *ovsdb_jsonrpc_server_add_remote(
 104     struct ovsdb_jsonrpc_server *, const char *name,
 105     const struct ovsdb_jsonrpc_options *options
 106 );
 107 static void ovsdb_jsonrpc_server_del_remote(struct shash_node *);
 108
 109 struct ovsdb_jsonrpc_server *
 110 ovsdb_jsonrpc_server_create(struct ovsdb *db)
 111 {
 112     struct ovsdb_jsonrpc_server *server = xzalloc(sizeof *server);
 113     ovsdb_server_init(&server->up, db);
 114     server->max_sessions = 64;
 115     shash_init(&server->remotes);
 116     return server;
 117 }
 118
 119 void
 120 ovsdb_jsonrpc_server_destroy(struct ovsdb_jsonrpc_server *svr)
 121 {
 122     struct shash_node *node, *next;
 123
 124     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
 125         ovsdb_jsonrpc_server_del_remote(node);
 126     }
 127     shash_destroy(&svr->remotes);
 128     ovsdb_server_destroy(&svr->up);
 129     free(svr);
 130 }
 131
 132 struct ovsdb_jsonrpc_options *
 133 ovsdb_jsonrpc_default_options(const char *target)
 134 {
 135     struct ovsdb_jsonrpc_options *options = xzalloc(sizeof *options);
 136     options->max_backoff = RECONNECT_DEFAULT_MAX_BACKOFF;
 137     options->probe_interval = (stream_or_pstream_needs_probes(target)
 138                                ? RECONNECT_DEFAULT_PROBE_INTERVAL
 139                                : 0);
 140     return options;
 141 }
 142
 143 /* Sets 'svr''s current set of remotes to the names in 'new_remotes', with
 144  * options in the struct ovsdb_jsonrpc_options supplied as the data values.
 145  *
 146  * A remote is an active or passive stream connection method, e.g. "pssl:" or
 147  * "tcp:1.2.3.4". */
 148 void
 149 ovsdb_jsonrpc_server_set_remotes(struct ovsdb_jsonrpc_server *svr,
 150                                  const struct shash *new_remotes)
 151 {
 152     struct shash_node *node, *next;
 153
 154     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
 155         if (!shash_find(new_remotes, node->name)) {
 156             VLOG_INFO("%s: remote deconfigured", node->name);
 157             ovsdb_jsonrpc_server_del_remote(node);
 158         }
 159     }
 160     SHASH_FOR_EACH (node, new_remotes) {
 161         const struct ovsdb_jsonrpc_options *options = node->data;
 162         struct ovsdb_jsonrpc_remote *remote;
 163
 164         remote = shash_find_data(&svr->remotes, node->name);
 165         if (!remote) {
 166             remote = ovsdb_jsonrpc_server_add_remote(svr, node->name, options);
 167             if (!remote) {
 168                 continue;
 169             }
 170         }
 171
 172         ovsdb_jsonrpc_session_set_all_options(remote, options);
 173     }
 174 }
 175
 176 static struct ovsdb_jsonrpc_remote *
 177 ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *svr,
 178                                 const char *name,
 179                                 const struct ovsdb_jsonrpc_options *options)
 180 {
 181     struct ovsdb_jsonrpc_remote *remote;
 182     struct pstream *listener;
 183     int error;
 184
 185     error = jsonrpc_pstream_open(name, &listener, options->dscp);
 186     if (error && error != EAFNOSUPPORT) {
 187         VLOG_ERR_RL(&rl, "%s: listen failed: %s", name, strerror(error));
 188         return NULL;
 189     }
 190
 191     remote = xmalloc(sizeof *remote);
 192     remote->server = svr;
 193     remote->listener = listener;
 194     list_init(&remote->sessions);
 195     shash_add(&svr->remotes, name, remote);
 196
 197     if (!listener) {
 198         ovsdb_jsonrpc_session_create(remote, jsonrpc_session_open(name));
 199     }
 200     return remote;
 201 }
 202
 203 static void
 204 ovsdb_jsonrpc_server_del_remote(struct shash_node *node)
 205 {
 206     struct ovsdb_jsonrpc_remote *remote = node->data;
 207
 208     ovsdb_jsonrpc_session_close_all(remote);
 209     pstream_close(remote->listener);
 210     shash_delete(&remote->server->remotes, node);
 211     free(remote);
 212 }
 213
 214 /* Stores status information for the remote named 'target', which should have
 215  * been configured on 'svr' with a call to ovsdb_jsonrpc_server_set_remotes(),
 216  * into '*status'.  On success returns true, on failure (if 'svr' doesn't have
 217  * a remote named 'target' or if that remote is an inbound remote that has no
 218  * active connections) returns false.  On failure, 'status' will be zeroed.
 219  */
 220 bool
 221 ovsdb_jsonrpc_server_get_remote_status(
 222     const struct ovsdb_jsonrpc_server *svr, const char *target,
 223     struct ovsdb_jsonrpc_remote_status *status)
 224 {
 225     const struct ovsdb_jsonrpc_remote *remote;
 226
 227     memset(status, 0, sizeof *status);
 228
 229     remote = shash_find_data(&svr->remotes, target);
 230     return remote && ovsdb_jsonrpc_session_get_status(remote, status);
 231 }
 232
 233 void
 234 ovsdb_jsonrpc_server_free_remote_status(
 235     struct ovsdb_jsonrpc_remote_status *status)
 236 {
 237     free(status->locks_held);
 238     free(status->locks_waiting);
 239     free(status->locks_lost);
 240 }
 241
 242 /* Forces all of the JSON-RPC sessions managed by 'svr' to disconnect and
 243  * reconnect. */
 244 void
 245 ovsdb_jsonrpc_server_reconnect(struct ovsdb_jsonrpc_server *svr)
 246 {
 247     struct shash_node *node;
 248
 249     SHASH_FOR_EACH (node, &svr->remotes) {
 250         struct ovsdb_jsonrpc_remote *remote = node->data;
 251
 252         ovsdb_jsonrpc_session_reconnect_all(remote);
 253     }
 254 }
 255
 256 void
 257 ovsdb_jsonrpc_server_run(struct ovsdb_jsonrpc_server *svr)
 258 {
 259     struct shash_node *node;
 260
 261     SHASH_FOR_EACH (node, &svr->remotes) {
 262         struct ovsdb_jsonrpc_remote *remote = node->data;
 263
 264         if (remote->listener && svr->n_sessions < svr->max_sessions) {
 265             struct stream *stream;
 266             int error;
 267
 268             error = pstream_accept(remote->listener, &stream);
 269             if (!error) {
 270                 struct jsonrpc_session *js;
 271                 js = jsonrpc_session_open_unreliably(jsonrpc_open(stream));
 272                 ovsdb_jsonrpc_session_create(remote, js);
 273             } else if (error != EAGAIN) {
 274                 VLOG_WARN_RL(&rl, "%s: accept failed: %s",
 275                              pstream_get_name(remote->listener),
 276                              strerror(error));
 277             }
 278         }
 279
 280         ovsdb_jsonrpc_session_run_all(remote);
 281     }
 282 }
 283
 284 void
 285 ovsdb_jsonrpc_server_wait(struct ovsdb_jsonrpc_server *svr)
 286 {
 287     struct shash_node *node;
 288
 289     SHASH_FOR_EACH (node, &svr->remotes) {
 290         struct ovsdb_jsonrpc_remote *remote = node->data;
 291
 292         if (remote->listener && svr->n_sessions < svr->max_sessions) {
 293             pstream_wait(remote->listener);
 294         }
 295
 296         ovsdb_jsonrpc_session_wait_all(remote);
 297     }
 298 }
 299
 300 /* Adds some memory usage statistics for 'svr' into 'usage', for use with
 301  * memory_report(). */
 302 void
 303 ovsdb_jsonrpc_server_get_memory_usage(const struct ovsdb_jsonrpc_server *svr,
 304                                       struct simap *usage)
 305 {
 306     struct shash_node *node;
 307
 308     simap_increase(usage, "sessions", svr->n_sessions);
 309     SHASH_FOR_EACH (node, &svr->remotes) {
 310         struct ovsdb_jsonrpc_remote *remote = node->data;
 311
 312         ovsdb_jsonrpc_session_get_memory_usage_all(remote, usage);
 313     }
 314 }
 315 \f
 316 /* JSON-RPC database server session. */
 317
 318 struct ovsdb_jsonrpc_session {
 319     struct list node;           /* Element in remote's sessions list. */
 320     struct ovsdb_session up;
 321     struct ovsdb_jsonrpc_remote *remote;
 322
 323     /* Triggers. */
 324     struct hmap triggers;       /* Hmap of "struct ovsdb_jsonrpc_trigger"s. */
 325
 326     /* Monitors. */
 327     struct hmap monitors;       /* Hmap of "struct ovsdb_jsonrpc_monitor"s. */
 328
 329     /* Network connectivity. */
 330     struct jsonrpc_session *js;  /* JSON-RPC session. */
 331     unsigned int js_seqno;       /* Last jsonrpc_session_get_seqno() value. */
 332 };
 333
 334 static void ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *);
 335 static int ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *);
 336 static void ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *);
 337 static void ovsdb_jsonrpc_session_get_memory_usage(
 338     const struct ovsdb_jsonrpc_session *, struct simap *usage);
 339 static void ovsdb_jsonrpc_session_set_options(
 340     struct ovsdb_jsonrpc_session *, const struct ovsdb_jsonrpc_options *);
 341 static void ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *,
 342                                              struct jsonrpc_msg *);
 343 static void ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *,
 344                                              struct jsonrpc_msg *);
 345
 346 static struct ovsdb_jsonrpc_session *
 347 ovsdb_jsonrpc_session_create(struct ovsdb_jsonrpc_remote *remote,
 348                              struct jsonrpc_session *js)
 349 {
 350     struct ovsdb_jsonrpc_session *s;
 351
 352     s = xzalloc(sizeof *s);
 353     ovsdb_session_init(&s->up, remote->server->up.db);
 354     s->remote = remote;
 355     list_push_back(&remote->sessions, &s->node);
 356     hmap_init(&s->triggers);
 357     hmap_init(&s->monitors);
 358     s->js = js;
 359     s->js_seqno = jsonrpc_session_get_seqno(js);
 360
 361     remote->server->n_sessions++;
 362
 363     return s;
 364 }
 365
 366 static void
 367 ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *s)
 368 {
 369     ovsdb_jsonrpc_monitor_remove_all(s);
 370     ovsdb_jsonrpc_session_unlock_all(s);
 371     jsonrpc_session_close(s->js);
 372     list_remove(&s->node);
 373     ovsdb_session_destroy(&s->up);
 374     s->remote->server->n_sessions--;
 375     ovsdb_session_destroy(&s->up);
 376     free(s);
 377 }
 378
 379 static int
 380 ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *s)
 381 {
 382     jsonrpc_session_run(s->js);
 383     if (s->js_seqno != jsonrpc_session_get_seqno(s->js)) {
 384         s->js_seqno = jsonrpc_session_get_seqno(s->js);
 385         ovsdb_jsonrpc_trigger_complete_all(s);
 386         ovsdb_jsonrpc_monitor_remove_all(s);
 387         ovsdb_jsonrpc_session_unlock_all(s);
 388     }
 389
 390     ovsdb_jsonrpc_trigger_complete_done(s);
 391
 392     if (!jsonrpc_session_get_backlog(s->js)) {
 393         struct jsonrpc_msg *msg = jsonrpc_session_recv(s->js);
 394         if (msg) {
 395             if (msg->type == JSONRPC_REQUEST) {
 396                 ovsdb_jsonrpc_session_got_request(s, msg);
 397             } else if (msg->type == JSONRPC_NOTIFY) {
 398                 ovsdb_jsonrpc_session_got_notify(s, msg);
 399             } else {
 400                 VLOG_WARN("%s: received unexpected %s message",
 401                           jsonrpc_session_get_name(s->js),
 402                           jsonrpc_msg_type_to_string(msg->type));
 403                 jsonrpc_session_force_reconnect(s->js);
 404                 jsonrpc_msg_destroy(msg);
 405             }
 406         }
 407     }
 408     return jsonrpc_session_is_alive(s->js) ? 0 : ETIMEDOUT;
 409 }
 410
 411 static void
 412 ovsdb_jsonrpc_session_set_options(struct ovsdb_jsonrpc_session *session,
 413                                   const struct ovsdb_jsonrpc_options *options)
 414 {
 415     jsonrpc_session_set_max_backoff(session->js, options->max_backoff);
 416     jsonrpc_session_set_probe_interval(session->js, options->probe_interval);
 417     jsonrpc_session_set_dscp(session->js, options->dscp);
 418 }
 419
 420 static void
 421 ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *remote)
 422 {
 423     struct ovsdb_jsonrpc_session *s, *next;
 424
 425     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
 426         int error = ovsdb_jsonrpc_session_run(s);
 427         if (error) {
 428             ovsdb_jsonrpc_session_close(s);
 429         }
 430     }
 431 }
 432
 433 static void
 434 ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *s)
 435 {
 436     jsonrpc_session_wait(s->js);
 437     if (!jsonrpc_session_get_backlog(s->js)) {
 438         jsonrpc_session_recv_wait(s->js);
 439     }
 440 }
 441
 442 static void
 443 ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *remote)
 444 {
 445     struct ovsdb_jsonrpc_session *s;
 446
 447     LIST_FOR_EACH (s, node, &remote->sessions) {
 448         ovsdb_jsonrpc_session_wait(s);
 449     }
 450 }
 451
 452 static void
 453 ovsdb_jsonrpc_session_get_memory_usage(const struct ovsdb_jsonrpc_session *s,
 454                                        struct simap *usage)
 455 {
 456     simap_increase(usage, "triggers", hmap_count(&s->triggers));
 457     simap_increase(usage, "monitors", hmap_count(&s->monitors));
 458     simap_increase(usage, "backlog", jsonrpc_session_get_backlog(s->js));
 459 }
 460
 461 static void
 462 ovsdb_jsonrpc_session_get_memory_usage_all(
 463     const struct ovsdb_jsonrpc_remote *remote,
 464     struct simap *usage)
 465 {
 466     struct ovsdb_jsonrpc_session *s;
 467
 468     LIST_FOR_EACH (s, node, &remote->sessions) {
 469         ovsdb_jsonrpc_session_get_memory_usage(s, usage);
 470     }
 471 }
 472
 473 static void
 474 ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *remote)
 475 {
 476     struct ovsdb_jsonrpc_session *s, *next;
 477
 478     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
 479         ovsdb_jsonrpc_session_close(s);
 480     }
 481 }
 482
 483 /* Forces all of the JSON-RPC sessions managed by 'remote' to disconnect and
 484  * reconnect. */
 485 static void
 486 ovsdb_jsonrpc_session_reconnect_all(struct ovsdb_jsonrpc_remote *remote)
 487 {
 488     struct ovsdb_jsonrpc_session *s, *next;
 489
 490     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
 491         jsonrpc_session_force_reconnect(s->js);
 492         if (!jsonrpc_session_is_alive(s->js)) {
 493             ovsdb_jsonrpc_session_close(s);
 494         }
 495     }
 496 }
 497
 498 /* Sets the options for all of the JSON-RPC sessions managed by 'remote' to
 499  * 'options'. */
 500 static void
 501 ovsdb_jsonrpc_session_set_all_options(
 502     struct ovsdb_jsonrpc_remote *remote,
 503     const struct ovsdb_jsonrpc_options *options)
 504 {
 505     struct ovsdb_jsonrpc_session *s;
 506
 507     LIST_FOR_EACH (s, node, &remote->sessions) {
 508         ovsdb_jsonrpc_session_set_options(s, options);
 509     }
 510 }
 511
 512 static bool
 513 ovsdb_jsonrpc_session_get_status(const struct ovsdb_jsonrpc_remote *remote,
 514                                  struct ovsdb_jsonrpc_remote_status *status)
 515 {
 516     const struct ovsdb_jsonrpc_session *s;
 517     const struct jsonrpc_session *js;
 518     struct ovsdb_lock_waiter *waiter;
 519     struct reconnect_stats rstats;
 520     struct ds locks_held, locks_waiting, locks_lost;
 521
 522     if (list_is_empty(&remote->sessions)) {
 523         return false;
 524     }
 525     s = CONTAINER_OF(remote->sessions.next, struct ovsdb_jsonrpc_session, node);
 526     js = s->js;
 527
 528     status->is_connected = jsonrpc_session_is_connected(js);
 529     status->last_error = jsonrpc_session_get_status(js);
 530
 531     jsonrpc_session_get_reconnect_stats(js, &rstats);
 532     status->state = rstats.state;
 533     status->sec_since_connect = rstats.msec_since_connect == UINT_MAX
 534         ? UINT_MAX : rstats.msec_since_connect / 1000;
 535     status->sec_since_disconnect = rstats.msec_since_disconnect == UINT_MAX
 536         ? UINT_MAX : rstats.msec_since_disconnect / 1000;
 537
 538     ds_init(&locks_held);
 539     ds_init(&locks_waiting);
 540     ds_init(&locks_lost);
 541     HMAP_FOR_EACH (waiter, session_node, &s->up.waiters) {
 542         struct ds *string;
 543
 544         string = (ovsdb_lock_waiter_is_owner(waiter) ? &locks_held
 545                   : waiter->mode == OVSDB_LOCK_WAIT ? &locks_waiting
 546                   : &locks_lost);
 547         if (string->length) {
 548             ds_put_char(string, ' ');
 549         }
 550         ds_put_cstr(string, waiter->lock_name);
 551     }
 552     status->locks_held = ds_steal_cstr(&locks_held);
 553     status->locks_waiting = ds_steal_cstr(&locks_waiting);
 554     status->locks_lost = ds_steal_cstr(&locks_lost);
 555
 556     status->n_connections = list_size(&remote->sessions);
 557
 558     return true;
 559 }
 560
 561 static const char *
 562 get_db_name(const struct ovsdb_jsonrpc_session *s)
 563 {
 564     return s->remote->server->up.db->schema->name;
 565 }
 566
 567 static struct jsonrpc_msg *
 568 ovsdb_jsonrpc_check_db_name(const struct ovsdb_jsonrpc_session *s,
 569                             const struct jsonrpc_msg *request)
 570 {
 571     struct json_array *params;
 572     const char *want_db_name;
 573     const char *have_db_name;
 574     struct ovsdb_error *error;
 575     struct jsonrpc_msg *reply;
 576
 577     params = json_array(request->params);
 578     if (!params->n || params->elems[0]->type != JSON_STRING) {
 579         error = ovsdb_syntax_error(
 580             request->params, NULL,
 581             "%s request params must begin with <db-name>", request->method);
 582         goto error;
 583     }
 584
 585     want_db_name = params->elems[0]->u.string;
 586     have_db_name = get_db_name(s);
 587     if (strcmp(want_db_name, have_db_name)) {
 588         error = ovsdb_syntax_error(
 589             request->params, "unknown database",
 590             "%s request specifies unknown database %s",
 591             request->method, want_db_name);
 592         goto error;
 593     }
 594
 595     return NULL;
 596
 597 error:
 598     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
 599     ovsdb_error_destroy(error);
 600     return reply;
 601 }
 602
 603 static struct ovsdb_error *
 604 ovsdb_jsonrpc_session_parse_lock_name(const struct jsonrpc_msg *request,
 605                                       const char **lock_namep)
 606 {
 607     const struct json_array *params;
 608
 609     params = json_array(request->params);
 610     if (params->n != 1 || params->elems[0]->type != JSON_STRING ||
 611         !ovsdb_parser_is_id(json_string(params->elems[0]))) {
 612         *lock_namep = NULL;
 613         return ovsdb_syntax_error(request->params, NULL,
 614                                   "%s request params must be <id>",
 615                                   request->method);
 616     }
 617
 618     *lock_namep = json_string(params->elems[0]);
 619     return NULL;
 620 }
 621
 622 static void
 623 ovsdb_jsonrpc_session_notify(struct ovsdb_session *session,
 624                              const char *lock_name,
 625                              const char *method)
 626 {
 627     struct ovsdb_jsonrpc_session *s;
 628     struct json *params;
 629
 630     s = CONTAINER_OF(session, struct ovsdb_jsonrpc_session, up);
 631     params = json_array_create_1(json_string_create(lock_name));
 632     jsonrpc_session_send(s->js, jsonrpc_create_notify(method, params));
 633 }
 634
 635 static struct jsonrpc_msg *
 636 ovsdb_jsonrpc_session_lock(struct ovsdb_jsonrpc_session *s,
 637                            struct jsonrpc_msg *request,
 638                            enum ovsdb_lock_mode mode)
 639 {
 640     struct ovsdb_lock_waiter *waiter;
 641     struct jsonrpc_msg *reply;
 642     struct ovsdb_error *error;
 643     struct ovsdb_session *victim;
 644     const char *lock_name;
 645     struct json *result;
 646
 647     error = ovsdb_jsonrpc_session_parse_lock_name(request, &lock_name);
 648     if (error) {
 649         goto error;
 650     }
 651
 652     /* Report error if this session has issued a "lock" or "steal" without a
 653      * matching "unlock" for this lock. */
 654     waiter = ovsdb_session_get_lock_waiter(&s->up, lock_name);
 655     if (waiter) {
 656         error = ovsdb_syntax_error(
 657             request->params, NULL,
 658             "must issue \"unlock\" before new \"%s\"", request->method);
 659         goto error;
 660     }
 661
 662     /* Get the lock, add us as a waiter. */
 663     waiter = ovsdb_server_lock(&s->remote->server->up, &s->up, lock_name, mode,
 664                                &victim);
 665     if (victim) {
 666         ovsdb_jsonrpc_session_notify(victim, lock_name, "stolen");
 667     }
 668
 669     result = json_object_create();
 670     json_object_put(result, "locked",
 671                     json_boolean_create(ovsdb_lock_waiter_is_owner(waiter)));
 672
 673     return jsonrpc_create_reply(result, request->id);
 674
 675 error:
 676     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
 677     ovsdb_error_destroy(error);
 678     return reply;
 679 }
 680
 681 static void
 682 ovsdb_jsonrpc_session_unlock_all(struct ovsdb_jsonrpc_session *s)
 683 {
 684     struct ovsdb_lock_waiter *waiter, *next;
 685
 686     HMAP_FOR_EACH_SAFE (waiter, next, session_node, &s->up.waiters) {
 687         ovsdb_jsonrpc_session_unlock__(waiter);
 688     }
 689 }
 690
 691 static void
 692 ovsdb_jsonrpc_session_unlock__(struct ovsdb_lock_waiter *waiter)
 693 {
 694     struct ovsdb_lock *lock = waiter->lock;
 695
 696     if (lock) {
 697         struct ovsdb_session *new_owner = ovsdb_lock_waiter_remove(waiter);
 698         if (new_owner) {
 699             ovsdb_jsonrpc_session_notify(new_owner, lock->name, "locked");
 700         } else {
 701             /* ovsdb_server_lock() might have freed 'lock'. */
 702         }
 703     }
 704
 705     ovsdb_lock_waiter_destroy(waiter);
 706 }
 707
 708 static struct jsonrpc_msg *
 709 ovsdb_jsonrpc_session_unlock(struct ovsdb_jsonrpc_session *s,
 710                              struct jsonrpc_msg *request)
 711 {
 712     struct ovsdb_lock_waiter *waiter;
 713     struct jsonrpc_msg *reply;
 714     struct ovsdb_error *error;
 715     const char *lock_name;
 716
 717     error = ovsdb_jsonrpc_session_parse_lock_name(request, &lock_name);
 718     if (error) {
 719         goto error;
 720     }
 721
 722     /* Report error if this session has not issued a "lock" or "steal" for this
 723      * lock. */
 724     waiter = ovsdb_session_get_lock_waiter(&s->up, lock_name);
 725     if (!waiter) {
 726         error = ovsdb_syntax_error(
 727             request->params, NULL, "\"unlock\" without \"lock\" or \"steal\"");
 728         goto error;
 729     }
 730
 731     ovsdb_jsonrpc_session_unlock__(waiter);
 732
 733     return jsonrpc_create_reply(json_object_create(), request->id);
 734
 735 error:
 736     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
 737     ovsdb_error_destroy(error);
 738     return reply;
 739 }
 740
 741 static struct jsonrpc_msg *
 742 execute_transaction(struct ovsdb_jsonrpc_session *s,
 743                     struct jsonrpc_msg *request)
 744 {
 745     ovsdb_jsonrpc_trigger_create(s, request->id, request->params);
 746     request->id = NULL;
 747     request->params = NULL;
 748     jsonrpc_msg_destroy(request);
 749     return NULL;
 750 }
 751
 752 static void
 753 ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *s,
 754                                   struct jsonrpc_msg *request)
 755 {
 756     struct jsonrpc_msg *reply;
 757
 758     if (!strcmp(request->method, "transact")) {
 759         reply = ovsdb_jsonrpc_check_db_name(s, request);
 760         if (!reply) {
 761             reply = execute_transaction(s, request);
 762         }
 763     } else if (!strcmp(request->method, "monitor")) {
 764         reply = ovsdb_jsonrpc_check_db_name(s, request);
 765         if (!reply) {
 766             reply = jsonrpc_create_reply(
 767                 ovsdb_jsonrpc_monitor_create(s, request->params), request->id);
 768         }
 769     } else if (!strcmp(request->method, "monitor_cancel")) {
 770         reply = ovsdb_jsonrpc_monitor_cancel(s, json_array(request->params),
 771                                              request->id);
 772     } else if (!strcmp(request->method, "get_schema")) {
 773         reply = ovsdb_jsonrpc_check_db_name(s, request);
 774         if (!reply) {
 775             reply = jsonrpc_create_reply(
 776                 ovsdb_schema_to_json(s->remote->server->up.db->schema),
 777                 request->id);
 778         }
 779     } else if (!strcmp(request->method, "list_dbs")) {
 780         reply = jsonrpc_create_reply(
 781             json_array_create_1(json_string_create(get_db_name(s))),
 782             request->id);
 783     } else if (!strcmp(request->method, "lock")) {
 784         reply = ovsdb_jsonrpc_session_lock(s, request, OVSDB_LOCK_WAIT);
 785     } else if (!strcmp(request->method, "steal")) {
 786         reply = ovsdb_jsonrpc_session_lock(s, request, OVSDB_LOCK_STEAL);
 787     } else if (!strcmp(request->method, "unlock")) {
 788         reply = ovsdb_jsonrpc_session_unlock(s, request);
 789     } else if (!strcmp(request->method, "echo")) {
 790         reply = jsonrpc_create_reply(json_clone(request->params), request->id);
 791     } else {
 792         reply = jsonrpc_create_error(json_string_create("unknown method"),
 793                                      request->id);
 794     }
 795
 796     if (reply) {
 797         jsonrpc_msg_destroy(request);
 798         jsonrpc_session_send(s->js, reply);
 799     }
 800 }
 801
 802 static void
 803 execute_cancel(struct ovsdb_jsonrpc_session *s, struct jsonrpc_msg *request)
 804 {
 805     if (json_array(request->params)->n == 1) {
 806         struct ovsdb_jsonrpc_trigger *t;
 807         struct json *id;
 808
 809         id = request->params->u.array.elems[0];
 810         t = ovsdb_jsonrpc_trigger_find(s, id, json_hash(id, 0));
 811         if (t) {
 812             ovsdb_jsonrpc_trigger_complete(t);
 813         }
 814     }
 815 }
 816
 817 static void
 818 ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *s,
 819                                  struct jsonrpc_msg *request)
 820 {
 821     if (!strcmp(request->method, "cancel")) {
 822         execute_cancel(s, request);
 823     }
 824     jsonrpc_msg_destroy(request);
 825 }
 826 \f
 827 /* JSON-RPC database server triggers.
 828  *
 829  * (Every transaction is treated as a trigger even if it doesn't actually have
 830  * any "wait" operations.) */
 831
 832 struct ovsdb_jsonrpc_trigger {
 833     struct ovsdb_trigger trigger;
 834     struct hmap_node hmap_node; /* In session's "triggers" hmap. */
 835     struct json *id;
 836 };
 837
 838 static void
 839 ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *s,
 840                              struct json *id, struct json *params)
 841 {
 842     struct ovsdb_jsonrpc_trigger *t;
 843     size_t hash;
 844
 845     /* Check for duplicate ID. */
 846     hash = json_hash(id, 0);
 847     t = ovsdb_jsonrpc_trigger_find(s, id, hash);
 848     if (t) {
 849         struct jsonrpc_msg *msg;
 850
 851         msg = jsonrpc_create_error(json_string_create("duplicate request ID"),
 852                                    id);
 853         jsonrpc_session_send(s->js, msg);
 854         json_destroy(id);
 855         json_destroy(params);
 856         return;
 857     }
 858
 859     /* Insert into trigger table. */
 860     t = xmalloc(sizeof *t);
 861     ovsdb_trigger_init(&s->up, &t->trigger, params, time_msec());
 862     t->id = id;
 863     hmap_insert(&s->triggers, &t->hmap_node, hash);
 864
 865     /* Complete early if possible. */
 866     if (ovsdb_trigger_is_complete(&t->trigger)) {
 867         ovsdb_jsonrpc_trigger_complete(t);
 868     }
 869 }
 870
 871 static struct ovsdb_jsonrpc_trigger *
 872 ovsdb_jsonrpc_trigger_find(struct ovsdb_jsonrpc_session *s,
 873                            const struct json *id, size_t hash)
 874 {
 875     struct ovsdb_jsonrpc_trigger *t;
 876
 877     HMAP_FOR_EACH_WITH_HASH (t, hmap_node, hash, &s->triggers) {
 878         if (json_equal(t->id, id)) {
 879             return t;
 880         }
 881     }
 882
 883     return NULL;
 884 }
 885
 886 static void
 887 ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *t)
 888 {
 889     struct ovsdb_jsonrpc_session *s;
 890
 891     s = CONTAINER_OF(t->trigger.session, struct ovsdb_jsonrpc_session, up);
 892
 893     if (jsonrpc_session_is_connected(s->js)) {
 894         struct jsonrpc_msg *reply;
 895         struct json *result;
 896
 897         result = ovsdb_trigger_steal_result(&t->trigger);
 898         if (result) {
 899             reply = jsonrpc_create_reply(result, t->id);
 900         } else {
 901             reply = jsonrpc_create_error(json_string_create("canceled"),
 902                                          t->id);
 903         }
 904         jsonrpc_session_send(s->js, reply);
 905     }
 906
 907     json_destroy(t->id);
 908     ovsdb_trigger_destroy(&t->trigger);
 909     hmap_remove(&s->triggers, &t->hmap_node);
 910     free(t);
 911 }
 912
 913 static void
 914 ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *s)
 915 {
 916     struct ovsdb_jsonrpc_trigger *t, *next;
 917     HMAP_FOR_EACH_SAFE (t, next, hmap_node, &s->triggers) {
 918         ovsdb_jsonrpc_trigger_complete(t);
 919     }
 920 }
 921
 922 static void
 923 ovsdb_jsonrpc_trigger_complete_done(struct ovsdb_jsonrpc_session *s)
 924 {
 925     while (!list_is_empty(&s->up.completions)) {
 926         struct ovsdb_jsonrpc_trigger *t
 927             = CONTAINER_OF(s->up.completions.next,
 928                            struct ovsdb_jsonrpc_trigger, trigger.node);
 929         ovsdb_jsonrpc_trigger_complete(t);
 930     }
 931 }
 932 \f
 933 /* JSON-RPC database table monitors. */
 934
 935 enum ovsdb_jsonrpc_monitor_selection {
 936     OJMS_INITIAL = 1 << 0,      /* All rows when monitor is created. */
 937     OJMS_INSERT = 1 << 1,       /* New rows. */
 938     OJMS_DELETE = 1 << 2,       /* Deleted rows. */
 939     OJMS_MODIFY = 1 << 3        /* Modified rows. */
 940 };
 941
 942 /* A particular column being monitored. */
 943 struct ovsdb_jsonrpc_monitor_column {
 944     const struct ovsdb_column *column;
 945     enum ovsdb_jsonrpc_monitor_selection select;
 946 };
 947
 948 /* A particular table being monitored. */
 949 struct ovsdb_jsonrpc_monitor_table {
 950     const struct ovsdb_table *table;
 951
 952     /* This is the union (bitwise-OR) of the 'select' values in all of the
 953      * members of 'columns' below. */
 954     enum ovsdb_jsonrpc_monitor_selection select;
 955
 956     /* Columns being monitored. */
 957     struct ovsdb_jsonrpc_monitor_column *columns;
 958     size_t n_columns;
 959 };
 960
 961 /* A collection of tables being monitored. */
 962 struct ovsdb_jsonrpc_monitor {
 963     struct ovsdb_replica replica;
 964     struct ovsdb_jsonrpc_session *session;
 965     struct hmap_node node;      /* In ovsdb_jsonrpc_session's "monitors". */
 966
 967     struct json *monitor_id;
 968     struct shash tables;     /* Holds "struct ovsdb_jsonrpc_monitor_table"s. */
 969 };
 970
 971 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class;
 972
 973 struct ovsdb_jsonrpc_monitor *ovsdb_jsonrpc_monitor_find(
 974     struct ovsdb_jsonrpc_session *, const struct json *monitor_id);
 975 static void ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *);
 976 static struct json *ovsdb_jsonrpc_monitor_get_initial(
 977     const struct ovsdb_jsonrpc_monitor *);
 978
 979 static bool
 980 parse_bool(struct ovsdb_parser *parser, const char *name, bool default_value)
 981 {
 982     const struct json *json;
 983
 984     json = ovsdb_parser_member(parser, name, OP_BOOLEAN | OP_OPTIONAL);
 985     return json ? json_boolean(json) : default_value;
 986 }
 987
 988 struct ovsdb_jsonrpc_monitor *
 989 ovsdb_jsonrpc_monitor_find(struct ovsdb_jsonrpc_session *s,
 990                            const struct json *monitor_id)
 991 {
 992     struct ovsdb_jsonrpc_monitor *m;
 993
 994     HMAP_FOR_EACH_WITH_HASH (m, node, json_hash(monitor_id, 0), &s->monitors) {
 995         if (json_equal(m->monitor_id, monitor_id)) {
 996             return m;
 997         }
 998     }
 999
1000     return NULL;
1001 }
1002
1003 static void
1004 ovsdb_jsonrpc_add_monitor_column(struct ovsdb_jsonrpc_monitor_table *mt,
1005                                  const struct ovsdb_column *column,
1006                                  enum ovsdb_jsonrpc_monitor_selection select,
1007                                  size_t *allocated_columns)
1008 {
1009     struct ovsdb_jsonrpc_monitor_column *c;
1010
1011     if (mt->n_columns >= *allocated_columns) {
1012         mt->columns = x2nrealloc(mt->columns, allocated_columns,
1013                                  sizeof *mt->columns);
1014     }
1015
1016     c = &mt->columns[mt->n_columns++];
1017     c->column = column;
1018     c->select = select;
1019 }
1020
1021 static int
1022 compare_ovsdb_jsonrpc_monitor_column(const void *a_, const void *b_)
1023 {
1024     const struct ovsdb_jsonrpc_monitor_column *a = a_;
1025     const struct ovsdb_jsonrpc_monitor_column *b = b_;
1026
1027     return a->column < b->column ? -1 : a->column > b->column;
1028 }
1029
1030 static struct ovsdb_error * WARN_UNUSED_RESULT
1031 ovsdb_jsonrpc_parse_monitor_request(struct ovsdb_jsonrpc_monitor_table *mt,
1032                                     const struct json *monitor_request,
1033                                     size_t *allocated_columns)
1034 {
1035     const struct ovsdb_table_schema *ts = mt->table->schema;
1036     enum ovsdb_jsonrpc_monitor_selection select;
1037     const struct json *columns, *select_json;
1038     struct ovsdb_parser parser;
1039     struct ovsdb_error *error;
1040
1041     ovsdb_parser_init(&parser, monitor_request, "table %s", ts->name);
1042     columns = ovsdb_parser_member(&parser, "columns", OP_ARRAY | OP_OPTIONAL);
1043     select_json = ovsdb_parser_member(&parser, "select",
1044                                       OP_OBJECT | OP_OPTIONAL);
1045     error = ovsdb_parser_finish(&parser);
1046     if (error) {
1047         return error;
1048     }
1049
1050     if (select_json) {
1051         select = 0;
1052         ovsdb_parser_init(&parser, select_json, "table %s select", ts->name);
1053         if (parse_bool(&parser, "initial", true)) {
1054             select |= OJMS_INITIAL;
1055         }
1056         if (parse_bool(&parser, "insert", true)) {
1057             select |= OJMS_INSERT;
1058         }
1059         if (parse_bool(&parser, "delete", true)) {
1060             select |= OJMS_DELETE;
1061         }
1062         if (parse_bool(&parser, "modify", true)) {
1063             select |= OJMS_MODIFY;
1064         }
1065         error = ovsdb_parser_finish(&parser);
1066         if (error) {
1067             return error;
1068         }
1069     } else {
1070         select = OJMS_INITIAL | OJMS_INSERT | OJMS_DELETE | OJMS_MODIFY;
1071     }
1072     mt->select |= select;
1073
1074     if (columns) {
1075         size_t i;
1076
1077         if (columns->type != JSON_ARRAY) {
1078             return ovsdb_syntax_error(columns, NULL,
1079                                       "array of column names expected");
1080         }
1081
1082         for (i = 0; i < columns->u.array.n; i++) {
1083             const struct ovsdb_column *column;
1084             const char *s;
1085
1086             if (columns->u.array.elems[i]->type != JSON_STRING) {
1087                 return ovsdb_syntax_error(columns, NULL,
1088                                           "array of column names expected");
1089             }
1090
1091             s = columns->u.array.elems[i]->u.string;
1092             column = shash_find_data(&mt->table->schema->columns, s);
1093             if (!column) {
1094                 return ovsdb_syntax_error(columns, NULL, "%s is not a valid "
1095                                           "column name", s);
1096             }
1097             ovsdb_jsonrpc_add_monitor_column(mt, column, select,
1098                                              allocated_columns);
1099         }
1100     } else {
1101         struct shash_node *node;
1102
1103         SHASH_FOR_EACH (node, &ts->columns) {
1104             const struct ovsdb_column *column = node->data;
1105             if (column->index != OVSDB_COL_UUID) {
1106                 ovsdb_jsonrpc_add_monitor_column(mt, column, select,
1107                                                  allocated_columns);
1108             }
1109         }
1110     }
1111
1112     return NULL;
1113 }
1114
1115 static struct json *
1116 ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s,
1117                              struct json *params)
1118 {
1119     struct ovsdb_jsonrpc_monitor *m = NULL;
1120     struct json *monitor_id, *monitor_requests;
1121     struct ovsdb_error *error = NULL;
1122     struct shash_node *node;
1123     struct json *json;
1124
1125     if (json_array(params)->n != 3) {
1126         error = ovsdb_syntax_error(params, NULL, "invalid parameters");
1127         goto error;
1128     }
1129     monitor_id = params->u.array.elems[1];
1130     monitor_requests = params->u.array.elems[2];
1131     if (monitor_requests->type != JSON_OBJECT) {
1132         error = ovsdb_syntax_error(monitor_requests, NULL,
1133                                    "monitor-requests must be object");
1134         goto error;
1135     }
1136
1137     if (ovsdb_jsonrpc_monitor_find(s, monitor_id)) {
1138         error = ovsdb_syntax_error(monitor_id, NULL, "duplicate monitor ID");
1139         goto error;
1140     }
1141
1142     m = xzalloc(sizeof *m);
1143     ovsdb_replica_init(&m->replica, &ovsdb_jsonrpc_replica_class);
1144     ovsdb_add_replica(s->remote->server->up.db, &m->replica);
1145     m->session = s;
1146     hmap_insert(&s->monitors, &m->node, json_hash(monitor_id, 0));
1147     m->monitor_id = json_clone(monitor_id);
1148     shash_init(&m->tables);
1149
1150     SHASH_FOR_EACH (node, json_object(monitor_requests)) {
1151         const struct ovsdb_table *table;
1152         struct ovsdb_jsonrpc_monitor_table *mt;
1153         size_t allocated_columns;
1154         const struct json *mr_value;
1155         size_t i;
1156
1157         table = ovsdb_get_table(s->remote->server->up.db, node->name);
1158         if (!table) {
1159             error = ovsdb_syntax_error(NULL, NULL,
1160                                        "no table named %s", node->name);
1161             goto error;
1162         }
1163
1164         mt = xzalloc(sizeof *mt);
1165         mt->table = table;
1166         shash_add(&m->tables, table->schema->name, mt);
1167
1168         /* Parse columns. */
1169         mr_value = node->data;
1170         allocated_columns = 0;
1171         if (mr_value->type == JSON_ARRAY) {
1172             const struct json_array *array = &mr_value->u.array;
1173
1174             for (i = 0; i < array->n; i++) {
1175                 error = ovsdb_jsonrpc_parse_monitor_request(
1176                     mt, array->elems[i], &allocated_columns);
1177                 if (error) {
1178                     goto error;
1179                 }
1180             }
1181         } else {
1182             error = ovsdb_jsonrpc_parse_monitor_request(
1183                 mt, mr_value, &allocated_columns);
1184             if (error) {
1185                 goto error;
1186             }
1187         }
1188
1189         /* Check for duplicate columns. */
1190         qsort(mt->columns, mt->n_columns, sizeof *mt->columns,
1191               compare_ovsdb_jsonrpc_monitor_column);
1192         for (i = 1; i < mt->n_columns; i++) {
1193             if (mt->columns[i].column == mt->columns[i - 1].column) {
1194                 error = ovsdb_syntax_error(mr_value, NULL, "column %s "
1195                                            "mentioned more than once",
1196                                            mt->columns[i].column->name);
1197                 goto error;
1198             }
1199         }
1200     }
1201
1202     return ovsdb_jsonrpc_monitor_get_initial(m);
1203
1204 error:
1205     if (m) {
1206         ovsdb_remove_replica(s->remote->server->up.db, &m->replica);
1207     }
1208
1209     json = ovsdb_error_to_json(error);
1210     ovsdb_error_destroy(error);
1211     return json;
1212 }
1213
1214 static struct jsonrpc_msg *
1215 ovsdb_jsonrpc_monitor_cancel(struct ovsdb_jsonrpc_session *s,
1216                              struct json_array *params,
1217                              const struct json *request_id)
1218 {
1219     if (params->n != 1) {
1220         return jsonrpc_create_error(json_string_create("invalid parameters"),
1221                                     request_id);
1222     } else {
1223         struct ovsdb_jsonrpc_monitor *m;
1224
1225         m = ovsdb_jsonrpc_monitor_find(s, params->elems[0]);
1226         if (!m) {
1227             return jsonrpc_create_error(json_string_create("unknown monitor"),
1228                                         request_id);
1229         } else {
1230             ovsdb_remove_replica(s->remote->server->up.db, &m->replica);
1231             return jsonrpc_create_reply(json_object_create(), request_id);
1232         }
1233     }
1234 }
1235
1236 static void
1237 ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *s)
1238 {
1239     struct ovsdb_jsonrpc_monitor *m, *next;
1240
1241     HMAP_FOR_EACH_SAFE (m, next, node, &s->monitors) {
1242         ovsdb_remove_replica(s->remote->server->up.db, &m->replica);
1243     }
1244 }
1245
1246 static struct ovsdb_jsonrpc_monitor *
1247 ovsdb_jsonrpc_monitor_cast(struct ovsdb_replica *replica)
1248 {
1249     assert(replica->class == &ovsdb_jsonrpc_replica_class);
1250     return CONTAINER_OF(replica, struct ovsdb_jsonrpc_monitor, replica);
1251 }
1252
1253 struct ovsdb_jsonrpc_monitor_aux {
1254     bool initial;               /* Sending initial contents of table? */
1255     const struct ovsdb_jsonrpc_monitor *monitor;
1256     struct json *json;          /* JSON for the whole transaction. */
1257
1258     /* Current table.  */
1259     struct ovsdb_jsonrpc_monitor_table *mt;
1260     struct json *table_json;    /* JSON for table's transaction. */
1261 };
1262
1263 static bool
1264 any_reportable_change(const struct ovsdb_jsonrpc_monitor_table *mt,
1265                       const unsigned long int *changed)
1266 {
1267     size_t i;
1268
1269     for (i = 0; i < mt->n_columns; i++) {
1270         const struct ovsdb_jsonrpc_monitor_column *c = &mt->columns[i];
1271         unsigned int idx = c->column->index;
1272
1273         if (c->select & OJMS_MODIFY && bitmap_is_set(changed, idx)) {
1274             return true;
1275         }
1276     }
1277
1278     return false;
1279 }
1280
1281 static bool
1282 ovsdb_jsonrpc_monitor_change_cb(const struct ovsdb_row *old,
1283                                 const struct ovsdb_row *new,
1284                                 const unsigned long int *changed,
1285                                 void *aux_)
1286 {
1287     struct ovsdb_jsonrpc_monitor_aux *aux = aux_;
1288     const struct ovsdb_jsonrpc_monitor *m = aux->monitor;
1289     struct ovsdb_table *table = new ? new->table : old->table;
1290     enum ovsdb_jsonrpc_monitor_selection type;
1291     struct json *old_json, *new_json;
1292     struct json *row_json;
1293     char uuid[UUID_LEN + 1];
1294     size_t i;
1295
1296     if (!aux->mt || table != aux->mt->table) {
1297         aux->mt = shash_find_data(&m->tables, table->schema->name);
1298         aux->table_json = NULL;
1299         if (!aux->mt) {
1300             /* We don't care about rows in this table at all.  Tell the caller
1301              * to skip it.  */
1302             return false;
1303         }
1304     }
1305
1306     type = (aux->initial ? OJMS_INITIAL
1307             : !old ? OJMS_INSERT
1308             : !new ? OJMS_DELETE
1309             : OJMS_MODIFY);
1310     if (!(aux->mt->select & type)) {
1311         /* We don't care about this type of change (but do want to be called
1312          * back for changes to other rows in the same table). */
1313         return true;
1314     }
1315
1316     if (type == OJMS_MODIFY && !any_reportable_change(aux->mt, changed)) {
1317         /* Nothing of interest changed. */
1318         return true;
1319     }
1320
1321     old_json = new_json = NULL;
1322     if (type & (OJMS_DELETE | OJMS_MODIFY)) {
1323         old_json = json_object_create();
1324     }
1325     if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
1326         new_json = json_object_create();
1327     }
1328     for (i = 0; i < aux->mt->n_columns; i++) {
1329         const struct ovsdb_jsonrpc_monitor_column *c = &aux->mt->columns[i];
1330         const struct ovsdb_column *column = c->column;
1331         unsigned int idx = c->column->index;
1332
1333         if (!(type & c->select)) {
1334             /* We don't care about this type of change for this particular
1335              * column (but we will care about it for some other column). */
1336             continue;
1337         }
1338
1339         if ((type == OJMS_MODIFY && bitmap_is_set(changed, idx))
1340             || type == OJMS_DELETE) {
1341             json_object_put(old_json, column->name,
1342                             ovsdb_datum_to_json(&old->fields[idx],
1343                                                 &column->type));
1344         }
1345         if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
1346             json_object_put(new_json, column->name,
1347                             ovsdb_datum_to_json(&new->fields[idx],
1348                                                 &column->type));
1349         }
1350     }
1351
1352     /* Create JSON object for transaction overall. */
1353     if (!aux->json) {
1354         aux->json = json_object_create();
1355     }
1356
1357     /* Create JSON object for transaction on this table. */
1358     if (!aux->table_json) {
1359         aux->table_json = json_object_create();
1360         json_object_put(aux->json, aux->mt->table->schema->name,
1361                         aux->table_json);
1362     }
1363
1364     /* Create JSON object for transaction on this row. */
1365     row_json = json_object_create();
1366     if (old_json) {
1367         json_object_put(row_json, "old", old_json);
1368     }
1369     if (new_json) {
1370         json_object_put(row_json, "new", new_json);
1371     }
1372
1373     /* Add JSON row to JSON table. */
1374     snprintf(uuid, sizeof uuid,
1375              UUID_FMT, UUID_ARGS(ovsdb_row_get_uuid(new ? new : old)));
1376     json_object_put(aux->table_json, uuid, row_json);
1377
1378     return true;
1379 }
1380
1381 static void
1382 ovsdb_jsonrpc_monitor_init_aux(struct ovsdb_jsonrpc_monitor_aux *aux,
1383                                const struct ovsdb_jsonrpc_monitor *m,
1384                                bool initial)
1385 {
1386     aux->initial = initial;
1387     aux->monitor = m;
1388     aux->json = NULL;
1389     aux->mt = NULL;
1390     aux->table_json = NULL;
1391 }
1392
1393 static struct ovsdb_error *
1394 ovsdb_jsonrpc_monitor_commit(struct ovsdb_replica *replica,
1395                              const struct ovsdb_txn *txn,
1396                              bool durable OVS_UNUSED)
1397 {
1398     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1399     struct ovsdb_jsonrpc_monitor_aux aux;
1400
1401     ovsdb_jsonrpc_monitor_init_aux(&aux, m, false);
1402     ovsdb_txn_for_each_change(txn, ovsdb_jsonrpc_monitor_change_cb, &aux);
1403     if (aux.json) {
1404         struct jsonrpc_msg *msg;
1405         struct json *params;
1406
1407         params = json_array_create_2(json_clone(aux.monitor->monitor_id),
1408                                      aux.json);
1409         msg = jsonrpc_create_notify("update", params);
1410         jsonrpc_session_send(aux.monitor->session->js, msg);
1411     }
1412
1413     return NULL;
1414 }
1415
1416 static struct json *
1417 ovsdb_jsonrpc_monitor_get_initial(const struct ovsdb_jsonrpc_monitor *m)
1418 {
1419     struct ovsdb_jsonrpc_monitor_aux aux;
1420     struct shash_node *node;
1421
1422     ovsdb_jsonrpc_monitor_init_aux(&aux, m, true);
1423     SHASH_FOR_EACH (node, &m->tables) {
1424         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1425
1426         if (mt->select & OJMS_INITIAL) {
1427             struct ovsdb_row *row;
1428
1429             HMAP_FOR_EACH (row, hmap_node, &mt->table->rows) {
1430                 ovsdb_jsonrpc_monitor_change_cb(NULL, row, NULL, &aux);
1431             }
1432         }
1433     }
1434     return aux.json ? aux.json : json_object_create();
1435 }
1436
1437 static void
1438 ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *replica)
1439 {
1440     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1441     struct shash_node *node;
1442
1443     json_destroy(m->monitor_id);
1444     SHASH_FOR_EACH (node, &m->tables) {
1445         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1446         free(mt->columns);
1447         free(mt);
1448     }
1449     shash_destroy(&m->tables);
1450     hmap_remove(&m->session->monitors, &m->node);
1451     free(m);
1452 }
1453
1454 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class = {
1455     ovsdb_jsonrpc_monitor_commit,
1456     ovsdb_jsonrpc_monitor_destroy
1457 };