ovsdb/jsonrpc-server.c

   1 /* Copyright (c) 2009, 2010 Nicira Networks
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include <config.h>
  17
  18 #include "jsonrpc-server.h"
  19
  20 #include <assert.h>
  21 #include <errno.h>
  22
  23 #include "column.h"
  24 #include "json.h"
  25 #include "jsonrpc.h"
  26 #include "ovsdb-error.h"
  27 #include "ovsdb-parser.h"
  28 #include "ovsdb.h"
  29 #include "reconnect.h"
  30 #include "row.h"
  31 #include "stream.h"
  32 #include "table.h"
  33 #include "timeval.h"
  34 #include "transaction.h"
  35 #include "trigger.h"
  36
  37 #define THIS_MODULE VLM_ovsdb_jsonrpc_server
  38 #include "vlog.h"
  39
  40 struct ovsdb_jsonrpc_remote;
  41 struct ovsdb_jsonrpc_session;
  42
  43 /* Message rate-limiting. */
  44 struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
  45
  46 /* Sessions. */
  47 static struct ovsdb_jsonrpc_session *ovsdb_jsonrpc_session_create(
  48     struct ovsdb_jsonrpc_remote *, struct jsonrpc_session *);
  49 static void ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *);
  50 static void ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *);
  51 static void ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *);
  52
  53 /* Triggers. */
  54 static void ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *,
  55                                          struct json *id, struct json *params);
  56 static struct ovsdb_jsonrpc_trigger *ovsdb_jsonrpc_trigger_find(
  57     struct ovsdb_jsonrpc_session *, const struct json *id, size_t hash);
  58 static void ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *);
  59 static void ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *);
  60 static void ovsdb_jsonrpc_trigger_complete_done(
  61     struct ovsdb_jsonrpc_session *);
  62
  63 /* Monitors. */
  64 static struct json *ovsdb_jsonrpc_monitor_create(
  65     struct ovsdb_jsonrpc_session *, struct json *params);
  66 static struct jsonrpc_msg *ovsdb_jsonrpc_monitor_cancel(
  67     struct ovsdb_jsonrpc_session *,
  68     struct json_array *params,
  69     const struct json *request_id);
  70 static void ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *);
  71 \f
  72 /* JSON-RPC database server. */
  73
  74 struct ovsdb_jsonrpc_server {
  75     struct ovsdb *db;
  76     unsigned int n_sessions, max_sessions;
  77     struct shash remotes;      /* Contains "struct ovsdb_jsonrpc_remote *"s. */
  78 };
  79
  80 /* A configured remote.  This is either a passive stream listener plus a list
  81  * of the currently connected sessions, or a list of exactly one active
  82  * session. */
  83 struct ovsdb_jsonrpc_remote {
  84     struct ovsdb_jsonrpc_server *server;
  85     struct pstream *listener;   /* Listener, if passive. */
  86     struct list sessions;       /* List of "struct ovsdb_jsonrpc_session"s. */
  87 };
  88
  89 static void ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *,
  90                                             const char *name);
  91 static void ovsdb_jsonrpc_server_del_remote(struct shash_node *);
  92
  93 struct ovsdb_jsonrpc_server *
  94 ovsdb_jsonrpc_server_create(struct ovsdb *db)
  95 {
  96     struct ovsdb_jsonrpc_server *server = xzalloc(sizeof *server);
  97     server->db = db;
  98     server->max_sessions = 64;
  99     shash_init(&server->remotes);
 100     return server;
 101 }
 102
 103 /* Sets 'svr''s current set of remotes to the names in 'new_remotes'.  The data
 104  * values in 'new_remotes' are ignored.
 105  *
 106  * A remote is an active or passive stream connection method, e.g. "pssl:" or
 107  * "tcp:1.2.3.4". */
 108 void
 109 ovsdb_jsonrpc_server_set_remotes(struct ovsdb_jsonrpc_server *svr,
 110                                  const struct shash *new_remotes)
 111 {
 112     struct shash_node *node, *next;
 113
 114     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
 115         if (!shash_find(new_remotes, node->name)) {
 116             ovsdb_jsonrpc_server_del_remote(node);
 117         }
 118     }
 119     SHASH_FOR_EACH (node, new_remotes) {
 120         if (!shash_find(&svr->remotes, node->name)) {
 121             ovsdb_jsonrpc_server_add_remote(svr, node->name);
 122         }
 123     }
 124 }
 125
 126 static void
 127 ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *svr,
 128                                 const char *name)
 129 {
 130     struct ovsdb_jsonrpc_remote *remote;
 131     struct pstream *listener;
 132     int error;
 133
 134     error = pstream_open(name, &listener);
 135     if (error && error != EAFNOSUPPORT) {
 136         VLOG_ERR_RL(&rl, "%s: listen failed: %s", name, strerror(error));
 137         return;
 138     }
 139
 140     remote = xmalloc(sizeof *remote);
 141     remote->server = svr;
 142     remote->listener = listener;
 143     list_init(&remote->sessions);
 144     shash_add(&svr->remotes, name, remote);
 145
 146     if (!listener) {
 147         ovsdb_jsonrpc_session_create(remote, jsonrpc_session_open(name));
 148     }
 149 }
 150
 151 static void
 152 ovsdb_jsonrpc_server_del_remote(struct shash_node *node)
 153 {
 154     struct ovsdb_jsonrpc_remote *remote = node->data;
 155
 156     ovsdb_jsonrpc_session_close_all(remote);
 157     pstream_close(remote->listener);
 158     shash_delete(&remote->server->remotes, node);
 159     free(remote);
 160 }
 161
 162 void
 163 ovsdb_jsonrpc_server_run(struct ovsdb_jsonrpc_server *svr)
 164 {
 165     struct shash_node *node;
 166
 167     SHASH_FOR_EACH (node, &svr->remotes) {
 168         struct ovsdb_jsonrpc_remote *remote = node->data;
 169
 170         if (remote->listener && svr->n_sessions < svr->max_sessions) {
 171             struct stream *stream;
 172             int error;
 173
 174             error = pstream_accept(remote->listener, &stream);
 175             if (!error) {
 176                 struct jsonrpc_session *js;
 177                 js = jsonrpc_session_open_unreliably(jsonrpc_open(stream));
 178                 ovsdb_jsonrpc_session_create(remote, js);
 179             } else if (error != EAGAIN) {
 180                 VLOG_WARN_RL(&rl, "%s: accept failed: %s",
 181                              pstream_get_name(remote->listener),
 182                              strerror(error));
 183             }
 184         }
 185
 186         ovsdb_jsonrpc_session_run_all(remote);
 187     }
 188 }
 189
 190 void
 191 ovsdb_jsonrpc_server_wait(struct ovsdb_jsonrpc_server *svr)
 192 {
 193     struct shash_node *node;
 194
 195     SHASH_FOR_EACH (node, &svr->remotes) {
 196         struct ovsdb_jsonrpc_remote *remote = node->data;
 197
 198         if (remote->listener && svr->n_sessions < svr->max_sessions) {
 199             pstream_wait(remote->listener);
 200         }
 201
 202         ovsdb_jsonrpc_session_wait_all(remote);
 203     }
 204 }
 205 \f
 206 /* JSON-RPC database server session. */
 207
 208 struct ovsdb_jsonrpc_session {
 209     struct ovsdb_jsonrpc_remote *remote;
 210     struct list node;           /* Element in remote's sessions list. */
 211
 212     /* Triggers. */
 213     struct hmap triggers;       /* Hmap of "struct ovsdb_jsonrpc_trigger"s. */
 214     struct list completions;    /* Completed triggers. */
 215
 216     /* Monitors. */
 217     struct hmap monitors;       /* Hmap of "struct ovsdb_jsonrpc_monitor"s. */
 218
 219     /* Network connectivity. */
 220     struct jsonrpc_session *js;  /* JSON-RPC session. */
 221     unsigned int js_seqno;       /* Last jsonrpc_session_get_seqno() value. */
 222 };
 223
 224 static void ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *);
 225 static int ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *);
 226 static void ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *);
 227 static void ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *,
 228                                              struct jsonrpc_msg *);
 229 static void ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *,
 230                                              struct jsonrpc_msg *);
 231
 232 static struct ovsdb_jsonrpc_session *
 233 ovsdb_jsonrpc_session_create(struct ovsdb_jsonrpc_remote *remote,
 234                              struct jsonrpc_session *js)
 235 {
 236     struct ovsdb_jsonrpc_session *s;
 237
 238     s = xzalloc(sizeof *s);
 239     s->remote = remote;
 240     list_push_back(&remote->sessions, &s->node);
 241     hmap_init(&s->triggers);
 242     hmap_init(&s->monitors);
 243     list_init(&s->completions);
 244     s->js = js;
 245     s->js_seqno = jsonrpc_session_get_seqno(js);
 246
 247     remote->server->n_sessions++;
 248
 249     return s;
 250 }
 251
 252 static void
 253 ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *s)
 254 {
 255     jsonrpc_session_close(s->js);
 256     list_remove(&s->node);
 257     s->remote->server->n_sessions--;
 258 }
 259
 260 static int
 261 ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *s)
 262 {
 263     jsonrpc_session_run(s->js);
 264     if (s->js_seqno != jsonrpc_session_get_seqno(s->js)) {
 265         s->js_seqno = jsonrpc_session_get_seqno(s->js);
 266         ovsdb_jsonrpc_trigger_complete_all(s);
 267         ovsdb_jsonrpc_monitor_remove_all(s);
 268     }
 269
 270     ovsdb_jsonrpc_trigger_complete_done(s);
 271
 272     if (!jsonrpc_session_get_backlog(s->js)) {
 273         struct jsonrpc_msg *msg = jsonrpc_session_recv(s->js);
 274         if (msg) {
 275             if (msg->type == JSONRPC_REQUEST) {
 276                 ovsdb_jsonrpc_session_got_request(s, msg);
 277             } else if (msg->type == JSONRPC_NOTIFY) {
 278                 ovsdb_jsonrpc_session_got_notify(s, msg);
 279             } else {
 280                 VLOG_WARN("%s: received unexpected %s message",
 281                           jsonrpc_session_get_name(s->js),
 282                           jsonrpc_msg_type_to_string(msg->type));
 283                 jsonrpc_session_force_reconnect(s->js);
 284                 jsonrpc_msg_destroy(msg);
 285             }
 286         }
 287     }
 288     return jsonrpc_session_is_alive(s->js) ? 0 : ETIMEDOUT;
 289 }
 290
 291 static void
 292 ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *remote)
 293 {
 294     struct ovsdb_jsonrpc_session *s, *next;
 295
 296     LIST_FOR_EACH_SAFE (s, next, struct ovsdb_jsonrpc_session, node,
 297                         &remote->sessions) {
 298         int error = ovsdb_jsonrpc_session_run(s);
 299         if (error) {
 300             ovsdb_jsonrpc_session_close(s);
 301         }
 302     }
 303 }
 304
 305 static void
 306 ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *s)
 307 {
 308     jsonrpc_session_wait(s->js);
 309     if (!jsonrpc_session_get_backlog(s->js)) {
 310         jsonrpc_session_recv_wait(s->js);
 311     }
 312 }
 313
 314 static void
 315 ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *remote)
 316 {
 317     struct ovsdb_jsonrpc_session *s;
 318
 319     LIST_FOR_EACH (s, struct ovsdb_jsonrpc_session, node, &remote->sessions) {
 320         ovsdb_jsonrpc_session_wait(s);
 321     }
 322 }
 323
 324 static void
 325 ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *remote)
 326 {
 327     struct ovsdb_jsonrpc_session *s, *next;
 328
 329     LIST_FOR_EACH_SAFE (s, next, struct ovsdb_jsonrpc_session, node,
 330                         &remote->sessions) {
 331         ovsdb_jsonrpc_session_close(s);
 332     }
 333 }
 334
 335 static struct jsonrpc_msg *
 336 execute_transaction(struct ovsdb_jsonrpc_session *s,
 337                     struct jsonrpc_msg *request)
 338 {
 339     ovsdb_jsonrpc_trigger_create(s, request->id, request->params);
 340     request->id = NULL;
 341     request->params = NULL;
 342     return NULL;
 343 }
 344
 345 static void
 346 ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *s,
 347                                   struct jsonrpc_msg *request)
 348 {
 349     struct jsonrpc_msg *reply;
 350
 351     if (!strcmp(request->method, "transact")) {
 352         reply = execute_transaction(s, request);
 353     } else if (!strcmp(request->method, "monitor")) {
 354         reply = jsonrpc_create_reply(
 355             ovsdb_jsonrpc_monitor_create(s, request->params), request->id);
 356     } else if (!strcmp(request->method, "monitor_cancel")) {
 357         reply = ovsdb_jsonrpc_monitor_cancel(s, json_array(request->params),
 358                                              request->id);
 359     } else if (!strcmp(request->method, "get_schema")) {
 360         reply = jsonrpc_create_reply(
 361             ovsdb_schema_to_json(s->remote->server->db->schema), request->id);
 362     } else if (!strcmp(request->method, "echo")) {
 363         reply = jsonrpc_create_reply(json_clone(request->params), request->id);
 364     } else {
 365         reply = jsonrpc_create_error(json_string_create("unknown method"),
 366                                      request->id);
 367     }
 368
 369     if (reply) {
 370         jsonrpc_msg_destroy(request);
 371         jsonrpc_session_send(s->js, reply);
 372     }
 373 }
 374
 375 static void
 376 execute_cancel(struct ovsdb_jsonrpc_session *s, struct jsonrpc_msg *request)
 377 {
 378     if (json_array(request->params)->n == 1) {
 379         struct ovsdb_jsonrpc_trigger *t;
 380         struct json *id;
 381
 382         id = request->params->u.array.elems[0];
 383         t = ovsdb_jsonrpc_trigger_find(s, id, json_hash(id, 0));
 384         if (t) {
 385             ovsdb_jsonrpc_trigger_complete(t);
 386         }
 387     }
 388 }
 389
 390 static void
 391 ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *s,
 392                                  struct jsonrpc_msg *request)
 393 {
 394     if (!strcmp(request->method, "cancel")) {
 395         execute_cancel(s, request);
 396     }
 397     jsonrpc_msg_destroy(request);
 398 }
 399 \f
 400 /* JSON-RPC database server triggers.
 401  *
 402  * (Every transaction is treated as a trigger even if it doesn't actually have
 403  * any "wait" operations.) */
 404
 405 struct ovsdb_jsonrpc_trigger {
 406     struct ovsdb_trigger trigger;
 407     struct ovsdb_jsonrpc_session *session;
 408     struct hmap_node hmap_node; /* In session's "triggers" hmap. */
 409     struct json *id;
 410 };
 411
 412 static void
 413 ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *s,
 414                              struct json *id, struct json *params)
 415 {
 416     struct ovsdb_jsonrpc_trigger *t;
 417     size_t hash;
 418
 419     /* Check for duplicate ID. */
 420     hash = json_hash(id, 0);
 421     t = ovsdb_jsonrpc_trigger_find(s, id, hash);
 422     if (t) {
 423         struct jsonrpc_msg *msg;
 424
 425         msg = jsonrpc_create_error(json_string_create("duplicate request ID"),
 426                                    id);
 427         jsonrpc_session_send(s->js, msg);
 428         json_destroy(id);
 429         json_destroy(params);
 430         return;
 431     }
 432
 433     /* Insert into trigger table. */
 434     t = xmalloc(sizeof *t);
 435     ovsdb_trigger_init(s->remote->server->db,
 436                        &t->trigger, params, &s->completions,
 437                        time_msec());
 438     t->session = s;
 439     t->id = id;
 440     hmap_insert(&s->triggers, &t->hmap_node, hash);
 441
 442     /* Complete early if possible. */
 443     if (ovsdb_trigger_is_complete(&t->trigger)) {
 444         ovsdb_jsonrpc_trigger_complete(t);
 445     }
 446 }
 447
 448 static struct ovsdb_jsonrpc_trigger *
 449 ovsdb_jsonrpc_trigger_find(struct ovsdb_jsonrpc_session *s,
 450                            const struct json *id, size_t hash)
 451 {
 452     struct ovsdb_jsonrpc_trigger *t;
 453
 454     HMAP_FOR_EACH_WITH_HASH (t, struct ovsdb_jsonrpc_trigger, hmap_node, hash,
 455                              &s->triggers) {
 456         if (json_equal(t->id, id)) {
 457             return t;
 458         }
 459     }
 460
 461     return NULL;
 462 }
 463
 464 static void
 465 ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *t)
 466 {
 467     struct ovsdb_jsonrpc_session *s = t->session;
 468
 469     if (jsonrpc_session_is_connected(s->js)) {
 470         struct jsonrpc_msg *reply;
 471         struct json *result;
 472
 473         result = ovsdb_trigger_steal_result(&t->trigger);
 474         if (result) {
 475             reply = jsonrpc_create_reply(result, t->id);
 476         } else {
 477             reply = jsonrpc_create_error(json_string_create("canceled"),
 478                                          t->id);
 479         }
 480         jsonrpc_session_send(s->js, reply);
 481     }
 482
 483     json_destroy(t->id);
 484     ovsdb_trigger_destroy(&t->trigger);
 485     hmap_remove(&s->triggers, &t->hmap_node);
 486     free(t);
 487 }
 488
 489 static void
 490 ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *s)
 491 {
 492     struct ovsdb_jsonrpc_trigger *t, *next;
 493     HMAP_FOR_EACH_SAFE (t, next, struct ovsdb_jsonrpc_trigger, hmap_node,
 494                         &s->triggers) {
 495         ovsdb_jsonrpc_trigger_complete(t);
 496     }
 497 }
 498
 499 static void
 500 ovsdb_jsonrpc_trigger_complete_done(struct ovsdb_jsonrpc_session *s)
 501 {
 502     while (!list_is_empty(&s->completions)) {
 503         struct ovsdb_jsonrpc_trigger *t
 504             = CONTAINER_OF(s->completions.next,
 505                            struct ovsdb_jsonrpc_trigger, trigger.node);
 506         ovsdb_jsonrpc_trigger_complete(t);
 507     }
 508 }
 509 \f
 510 /* JSON-RPC database table monitors. */
 511
 512 enum ovsdb_jsonrpc_monitor_selection {
 513     OJMS_INITIAL = 1 << 0,      /* All rows when monitor is created. */
 514     OJMS_INSERT = 1 << 1,       /* New rows. */
 515     OJMS_DELETE = 1 << 2,       /* Deleted rows. */
 516     OJMS_MODIFY = 1 << 3        /* Modified rows. */
 517 };
 518
 519 struct ovsdb_jsonrpc_monitor_table {
 520     const struct ovsdb_table *table;
 521     enum ovsdb_jsonrpc_monitor_selection select;
 522     struct ovsdb_column_set columns;
 523 };
 524
 525 struct ovsdb_jsonrpc_monitor {
 526     struct ovsdb_replica replica;
 527     struct ovsdb_jsonrpc_session *session;
 528     struct hmap_node node;      /* In ovsdb_jsonrpc_session's "monitors". */
 529
 530     struct json *monitor_id;
 531     struct shash tables;     /* Holds "struct ovsdb_jsonrpc_monitor_table"s. */
 532 };
 533
 534 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class;
 535
 536 struct ovsdb_jsonrpc_monitor *ovsdb_jsonrpc_monitor_find(
 537     struct ovsdb_jsonrpc_session *, const struct json *monitor_id);
 538 static void ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *);
 539 static struct json *ovsdb_jsonrpc_monitor_get_initial(
 540     const struct ovsdb_jsonrpc_monitor *);
 541
 542 static bool
 543 parse_bool(struct ovsdb_parser *parser, const char *name, bool default_value)
 544 {
 545     const struct json *json;
 546
 547     json = ovsdb_parser_member(parser, name, OP_BOOLEAN | OP_OPTIONAL);
 548     return json ? json_boolean(json) : default_value;
 549 }
 550
 551 struct ovsdb_jsonrpc_monitor *
 552 ovsdb_jsonrpc_monitor_find(struct ovsdb_jsonrpc_session *s,
 553                            const struct json *monitor_id)
 554 {
 555     struct ovsdb_jsonrpc_monitor *m;
 556
 557     HMAP_FOR_EACH_WITH_HASH (m, struct ovsdb_jsonrpc_monitor, node,
 558                              json_hash(monitor_id, 0), &s->monitors) {
 559         if (json_equal(m->monitor_id, monitor_id)) {
 560             return m;
 561         }
 562     }
 563
 564     return NULL;
 565 }
 566
 567 static struct json *
 568 ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s,
 569                              struct json *params)
 570 {
 571     struct ovsdb_jsonrpc_monitor *m = NULL;
 572     struct json *monitor_id, *monitor_requests;
 573     struct ovsdb_error *error = NULL;
 574     struct shash_node *node;
 575     struct json *json;
 576
 577     if (json_array(params)->n != 2) {
 578         error = ovsdb_syntax_error(params, NULL, "invalid parameters");
 579         goto error;
 580     }
 581     monitor_id = params->u.array.elems[0];
 582     monitor_requests = params->u.array.elems[1];
 583     if (monitor_requests->type != JSON_OBJECT) {
 584         error = ovsdb_syntax_error(monitor_requests, NULL,
 585                                    "monitor-requests must be object");
 586         goto error;
 587     }
 588
 589     if (ovsdb_jsonrpc_monitor_find(s, monitor_id)) {
 590         error = ovsdb_syntax_error(monitor_id, NULL, "duplicate monitor ID");
 591         goto error;
 592     }
 593
 594     m = xzalloc(sizeof *m);
 595     ovsdb_replica_init(&m->replica, &ovsdb_jsonrpc_replica_class);
 596     ovsdb_add_replica(s->remote->server->db, &m->replica);
 597     m->session = s;
 598     hmap_insert(&s->monitors, &m->node, json_hash(monitor_id, 0));
 599     m->monitor_id = json_clone(monitor_id);
 600     shash_init(&m->tables);
 601
 602     SHASH_FOR_EACH (node, json_object(monitor_requests)) {
 603         const struct ovsdb_table *table;
 604         struct ovsdb_jsonrpc_monitor_table *mt;
 605         const struct json *columns_json, *select_json;
 606         struct ovsdb_parser parser;
 607
 608         table = ovsdb_get_table(s->remote->server->db, node->name);
 609         if (!table) {
 610             error = ovsdb_syntax_error(NULL, NULL,
 611                                        "no table named %s", node->name);
 612             goto error;
 613         }
 614
 615         mt = xzalloc(sizeof *mt);
 616         mt->table = table;
 617         mt->select = OJMS_INITIAL | OJMS_INSERT | OJMS_DELETE | OJMS_MODIFY;
 618         ovsdb_column_set_init(&mt->columns);
 619         shash_add(&m->tables, table->schema->name, mt);
 620
 621         ovsdb_parser_init(&parser, node->data, "table %s", node->name);
 622         columns_json = ovsdb_parser_member(&parser, "columns",
 623                                            OP_ARRAY | OP_OPTIONAL);
 624         select_json = ovsdb_parser_member(&parser, "select",
 625                                           OP_OBJECT | OP_OPTIONAL);
 626         error = ovsdb_parser_finish(&parser);
 627         if (error) {
 628             goto error;
 629         }
 630
 631         if (columns_json) {
 632             error = ovsdb_column_set_from_json(columns_json, table,
 633                                                &mt->columns);
 634             if (error) {
 635                 goto error;
 636             }
 637         } else {
 638             struct shash_node *node;
 639
 640             SHASH_FOR_EACH (node, &table->schema->columns) {
 641                 const struct ovsdb_column *column = node->data;
 642                 if (column->index != OVSDB_COL_UUID) {
 643                     ovsdb_column_set_add(&mt->columns, column);
 644                 }
 645             }
 646         }
 647
 648         if (select_json) {
 649             mt->select = 0;
 650             ovsdb_parser_init(&parser, select_json, "table %s select",
 651                               table->schema->name);
 652             if (parse_bool(&parser, "initial", true)) {
 653                 mt->select |= OJMS_INITIAL;
 654             }
 655             if (parse_bool(&parser, "insert", true)) {
 656                 mt->select |= OJMS_INSERT;
 657             }
 658             if (parse_bool(&parser, "delete", true)) {
 659                 mt->select |= OJMS_DELETE;
 660             }
 661             if (parse_bool(&parser, "modify", true)) {
 662                 mt->select |= OJMS_MODIFY;
 663             }
 664             error = ovsdb_parser_finish(&parser);
 665             if (error) {
 666                 goto error;
 667             }
 668         }
 669     }
 670
 671     return ovsdb_jsonrpc_monitor_get_initial(m);
 672
 673 error:
 674     if (m) {
 675         ovsdb_remove_replica(s->remote->server->db, &m->replica);
 676     }
 677
 678     json = ovsdb_error_to_json(error);
 679     ovsdb_error_destroy(error);
 680     return json;
 681 }
 682
 683 static struct jsonrpc_msg *
 684 ovsdb_jsonrpc_monitor_cancel(struct ovsdb_jsonrpc_session *s,
 685                              struct json_array *params,
 686                              const struct json *request_id)
 687 {
 688     if (params->n != 1) {
 689         return jsonrpc_create_error(json_string_create("invalid parameters"),
 690                                     request_id);
 691     } else {
 692         struct ovsdb_jsonrpc_monitor *m;
 693
 694         m = ovsdb_jsonrpc_monitor_find(s, params->elems[0]);
 695         if (!m) {
 696             return jsonrpc_create_error(json_string_create("unknown monitor"),
 697                                         request_id);
 698         } else {
 699             ovsdb_remove_replica(s->remote->server->db, &m->replica);
 700             return jsonrpc_create_reply(json_object_create(), request_id);
 701         }
 702     }
 703 }
 704
 705 static void
 706 ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *s)
 707 {
 708     struct ovsdb_jsonrpc_monitor *m, *next;
 709
 710     HMAP_FOR_EACH_SAFE (m, next,
 711                         struct ovsdb_jsonrpc_monitor, node, &s->monitors) {
 712         ovsdb_remove_replica(s->remote->server->db, &m->replica);
 713     }
 714 }
 715
 716 static struct ovsdb_jsonrpc_monitor *
 717 ovsdb_jsonrpc_monitor_cast(struct ovsdb_replica *replica)
 718 {
 719     assert(replica->class == &ovsdb_jsonrpc_replica_class);
 720     return CONTAINER_OF(replica, struct ovsdb_jsonrpc_monitor, replica);
 721 }
 722
 723 struct ovsdb_jsonrpc_monitor_aux {
 724     bool initial;               /* Sending initial contents of table? */
 725     const struct ovsdb_jsonrpc_monitor *monitor;
 726     struct json *json;          /* JSON for the whole transaction. */
 727
 728     /* Current table.  */
 729     struct ovsdb_jsonrpc_monitor_table *mt;
 730     struct json *table_json;    /* JSON for table's transaction. */
 731 };
 732
 733 static bool
 734 ovsdb_jsonrpc_monitor_change_cb(const struct ovsdb_row *old,
 735                                 const struct ovsdb_row *new,
 736                                 void *aux_)
 737 {
 738     struct ovsdb_jsonrpc_monitor_aux *aux = aux_;
 739     const struct ovsdb_jsonrpc_monitor *m = aux->monitor;
 740     struct ovsdb_table *table = new ? new->table : old->table;
 741     enum ovsdb_jsonrpc_monitor_selection type;
 742     struct json *old_json, *new_json;
 743     struct json *row_json;
 744     char uuid[UUID_LEN + 1];
 745     int n_changed;
 746     size_t i;
 747
 748     if (!aux->mt || table != aux->mt->table) {
 749         aux->mt = shash_find_data(&m->tables, table->schema->name);
 750         aux->table_json = NULL;
 751         if (!aux->mt) {
 752             /* We don't care about rows in this table at all.  Tell the caller
 753              * to skip it.  */
 754             return false;
 755         }
 756     }
 757
 758     type = (aux->initial ? OJMS_INITIAL
 759             : !old ? OJMS_INSERT
 760             : !new ? OJMS_DELETE
 761             : OJMS_MODIFY);
 762     if (!(aux->mt->select & type)) {
 763         /* We don't care about this type of change (but do want to be called
 764          * back for changes to other rows in the same table). */
 765         return true;
 766     }
 767
 768     old_json = new_json = NULL;
 769     n_changed = 0;
 770     for (i = 0; i < aux->mt->columns.n_columns; i++) {
 771         const struct ovsdb_column *column = aux->mt->columns.columns[i];
 772         unsigned int idx = column->index;
 773         bool changed = false;
 774
 775         if (type == OJMS_MODIFY) {
 776             changed = !ovsdb_datum_equals(&old->fields[idx],
 777                                           &new->fields[idx], &column->type);
 778             n_changed += changed;
 779         }
 780         if (changed || type == OJMS_DELETE) {
 781             if (!old_json) {
 782                 old_json = json_object_create();
 783             }
 784             json_object_put(old_json, column->name,
 785                             ovsdb_datum_to_json(&old->fields[idx],
 786                                                 &column->type));
 787         }
 788         if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
 789             if (!new_json) {
 790                 new_json = json_object_create();
 791             }
 792             json_object_put(new_json, column->name,
 793                             ovsdb_datum_to_json(&new->fields[idx],
 794                                                 &column->type));
 795         }
 796     }
 797     if ((type == OJMS_MODIFY && !n_changed) || (!old_json && !new_json)) {
 798         /* No reportable changes. */
 799         json_destroy(old_json);
 800         json_destroy(new_json);
 801         return true;
 802     }
 803
 804     /* Create JSON object for transaction overall. */
 805     if (!aux->json) {
 806         aux->json = json_object_create();
 807     }
 808
 809     /* Create JSON object for transaction on this table. */
 810     if (!aux->table_json) {
 811         aux->table_json = json_object_create();
 812         json_object_put(aux->json, aux->mt->table->schema->name,
 813                         aux->table_json);
 814     }
 815
 816     /* Create JSON object for transaction on this row. */
 817     row_json = json_object_create();
 818     if (old_json) {
 819         json_object_put(row_json, "old", old_json);
 820     }
 821     if (new_json) {
 822         json_object_put(row_json, "new", new_json);
 823     }
 824
 825     /* Add JSON row to JSON table. */
 826     snprintf(uuid, sizeof uuid,
 827              UUID_FMT, UUID_ARGS(ovsdb_row_get_uuid(new ? new : old)));
 828     json_object_put(aux->table_json, uuid, row_json);
 829
 830     return true;
 831 }
 832
 833 static void
 834 ovsdb_jsonrpc_monitor_init_aux(struct ovsdb_jsonrpc_monitor_aux *aux,
 835                                const struct ovsdb_jsonrpc_monitor *m,
 836                                bool initial)
 837 {
 838     aux->initial = initial;
 839     aux->monitor = m;
 840     aux->json = NULL;
 841     aux->mt = NULL;
 842     aux->table_json = NULL;
 843 }
 844
 845 static struct ovsdb_error *
 846 ovsdb_jsonrpc_monitor_commit(struct ovsdb_replica *replica,
 847                              const struct ovsdb_txn *txn, bool durable UNUSED)
 848 {
 849     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
 850     struct ovsdb_jsonrpc_monitor_aux aux;
 851
 852     ovsdb_jsonrpc_monitor_init_aux(&aux, m, false);
 853     ovsdb_txn_for_each_change(txn, ovsdb_jsonrpc_monitor_change_cb, &aux);
 854     if (aux.json) {
 855         struct jsonrpc_msg *msg;
 856         struct json *params;
 857
 858         params = json_array_create_2(json_clone(aux.monitor->monitor_id),
 859                                      aux.json);
 860         msg = jsonrpc_create_notify("update", params);
 861         jsonrpc_session_send(aux.monitor->session->js, msg);
 862     }
 863
 864     return NULL;
 865 }
 866
 867 static struct json *
 868 ovsdb_jsonrpc_monitor_get_initial(const struct ovsdb_jsonrpc_monitor *m)
 869 {
 870     struct ovsdb_jsonrpc_monitor_aux aux;
 871     struct shash_node *node;
 872
 873     ovsdb_jsonrpc_monitor_init_aux(&aux, m, true);
 874     SHASH_FOR_EACH (node, &m->tables) {
 875         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
 876
 877         if (mt->select & OJMS_INITIAL) {
 878             struct ovsdb_row *row;
 879
 880             HMAP_FOR_EACH (row, struct ovsdb_row, hmap_node,
 881                            &mt->table->rows) {
 882                 ovsdb_jsonrpc_monitor_change_cb(NULL, row, &aux);
 883             }
 884         }
 885     }
 886     return aux.json ? aux.json : json_object_create();
 887 }
 888
 889 static void
 890 ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *replica)
 891 {
 892     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
 893     struct shash_node *node;
 894
 895     json_destroy(m->monitor_id);
 896     SHASH_FOR_EACH (node, &m->tables) {
 897         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
 898         ovsdb_column_set_destroy(&mt->columns);
 899         free(mt);
 900     }
 901     shash_destroy(&m->tables);
 902     hmap_remove(&m->session->monitors, &m->node);
 903     free(m);
 904 }
 905
 906 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class = {
 907     ovsdb_jsonrpc_monitor_commit,
 908     ovsdb_jsonrpc_monitor_destroy
 909 };