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