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->sec_since_connect = rstats.msec_since_connect == UINT_MAX
 474         ? UINT_MAX : rstats.msec_since_connect / 1000;
 475     status->sec_since_disconnect = rstats.msec_since_disconnect == UINT_MAX
 476         ? UINT_MAX : rstats.msec_since_disconnect / 1000;
 477
 478     return;
 479 }
 480
 481 static const char *
 482 get_db_name(const struct ovsdb_jsonrpc_session *s)
 483 {
 484     return s->remote->server->db->schema->name;
 485 }
 486
 487 static struct jsonrpc_msg *
 488 ovsdb_jsonrpc_check_db_name(const struct ovsdb_jsonrpc_session *s,
 489                             const struct jsonrpc_msg *request)
 490 {
 491     struct json_array *params;
 492     const char *want_db_name;
 493     const char *have_db_name;
 494     struct ovsdb_error *error;
 495     struct jsonrpc_msg *reply;
 496
 497     params = json_array(request->params);
 498     if (!params->n || params->elems[0]->type != JSON_STRING) {
 499         error = ovsdb_syntax_error(
 500             request->params, NULL,
 501             "%s request params must begin with <db-name>", request->method);
 502         goto error;
 503     }
 504
 505     want_db_name = params->elems[0]->u.string;
 506     have_db_name = get_db_name(s);
 507     if (strcmp(want_db_name, have_db_name)) {
 508         error = ovsdb_syntax_error(
 509             request->params, "unknown database",
 510             "%s request specifies unknown database %s",
 511             request->method, want_db_name);
 512         goto error;
 513     }
 514
 515     return NULL;
 516
 517 error:
 518     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
 519     ovsdb_error_destroy(error);
 520     return reply;
 521 }
 522
 523 static struct jsonrpc_msg *
 524 execute_transaction(struct ovsdb_jsonrpc_session *s,
 525                     struct jsonrpc_msg *request)
 526 {
 527     ovsdb_jsonrpc_trigger_create(s, request->id, request->params);
 528     request->id = NULL;
 529     request->params = NULL;
 530     jsonrpc_msg_destroy(request);
 531     return NULL;
 532 }
 533
 534 static void
 535 ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *s,
 536                                   struct jsonrpc_msg *request)
 537 {
 538     struct jsonrpc_msg *reply;
 539
 540     if (!strcmp(request->method, "transact")) {
 541         reply = ovsdb_jsonrpc_check_db_name(s, request);
 542         if (!reply) {
 543             reply = execute_transaction(s, request);
 544         }
 545     } else if (!strcmp(request->method, "monitor")) {
 546         reply = ovsdb_jsonrpc_check_db_name(s, request);
 547         if (!reply) {
 548             reply = jsonrpc_create_reply(
 549                 ovsdb_jsonrpc_monitor_create(s, request->params), request->id);
 550         }
 551     } else if (!strcmp(request->method, "monitor_cancel")) {
 552         reply = ovsdb_jsonrpc_monitor_cancel(s, json_array(request->params),
 553                                              request->id);
 554     } else if (!strcmp(request->method, "get_schema")) {
 555         reply = ovsdb_jsonrpc_check_db_name(s, request);
 556         if (!reply) {
 557             reply = jsonrpc_create_reply(
 558                 ovsdb_schema_to_json(s->remote->server->db->schema),
 559                 request->id);
 560         }
 561     } else if (!strcmp(request->method, "list_dbs")) {
 562         reply = jsonrpc_create_reply(
 563             json_array_create_1(json_string_create(get_db_name(s))),
 564             request->id);
 565     } else if (!strcmp(request->method, "echo")) {
 566         reply = jsonrpc_create_reply(json_clone(request->params), request->id);
 567     } else {
 568         reply = jsonrpc_create_error(json_string_create("unknown method"),
 569                                      request->id);
 570     }
 571
 572     if (reply) {
 573         jsonrpc_msg_destroy(request);
 574         jsonrpc_session_send(s->js, reply);
 575     }
 576 }
 577
 578 static void
 579 execute_cancel(struct ovsdb_jsonrpc_session *s, struct jsonrpc_msg *request)
 580 {
 581     if (json_array(request->params)->n == 1) {
 582         struct ovsdb_jsonrpc_trigger *t;
 583         struct json *id;
 584
 585         id = request->params->u.array.elems[0];
 586         t = ovsdb_jsonrpc_trigger_find(s, id, json_hash(id, 0));
 587         if (t) {
 588             ovsdb_jsonrpc_trigger_complete(t);
 589         }
 590     }
 591 }
 592
 593 static void
 594 ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *s,
 595                                  struct jsonrpc_msg *request)
 596 {
 597     if (!strcmp(request->method, "cancel")) {
 598         execute_cancel(s, request);
 599     }
 600     jsonrpc_msg_destroy(request);
 601 }
 602 \f
 603 /* JSON-RPC database server triggers.
 604  *
 605  * (Every transaction is treated as a trigger even if it doesn't actually have
 606  * any "wait" operations.) */
 607
 608 struct ovsdb_jsonrpc_trigger {
 609     struct ovsdb_trigger trigger;
 610     struct ovsdb_jsonrpc_session *session;
 611     struct hmap_node hmap_node; /* In session's "triggers" hmap. */
 612     struct json *id;
 613 };
 614
 615 static void
 616 ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *s,
 617                              struct json *id, struct json *params)
 618 {
 619     struct ovsdb_jsonrpc_trigger *t;
 620     size_t hash;
 621
 622     /* Check for duplicate ID. */
 623     hash = json_hash(id, 0);
 624     t = ovsdb_jsonrpc_trigger_find(s, id, hash);
 625     if (t) {
 626         struct jsonrpc_msg *msg;
 627
 628         msg = jsonrpc_create_error(json_string_create("duplicate request ID"),
 629                                    id);
 630         jsonrpc_session_send(s->js, msg);
 631         json_destroy(id);
 632         json_destroy(params);
 633         return;
 634     }
 635
 636     /* Insert into trigger table. */
 637     t = xmalloc(sizeof *t);
 638     ovsdb_trigger_init(s->remote->server->db,
 639                        &t->trigger, params, &s->completions,
 640                        time_msec());
 641     t->session = s;
 642     t->id = id;
 643     hmap_insert(&s->triggers, &t->hmap_node, hash);
 644
 645     /* Complete early if possible. */
 646     if (ovsdb_trigger_is_complete(&t->trigger)) {
 647         ovsdb_jsonrpc_trigger_complete(t);
 648     }
 649 }
 650
 651 static struct ovsdb_jsonrpc_trigger *
 652 ovsdb_jsonrpc_trigger_find(struct ovsdb_jsonrpc_session *s,
 653                            const struct json *id, size_t hash)
 654 {
 655     struct ovsdb_jsonrpc_trigger *t;
 656
 657     HMAP_FOR_EACH_WITH_HASH (t, hmap_node, hash, &s->triggers) {
 658         if (json_equal(t->id, id)) {
 659             return t;
 660         }
 661     }
 662
 663     return NULL;
 664 }
 665
 666 static void
 667 ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *t)
 668 {
 669     struct ovsdb_jsonrpc_session *s = t->session;
 670
 671     if (jsonrpc_session_is_connected(s->js)) {
 672         struct jsonrpc_msg *reply;
 673         struct json *result;
 674
 675         result = ovsdb_trigger_steal_result(&t->trigger);
 676         if (result) {
 677             reply = jsonrpc_create_reply(result, t->id);
 678         } else {
 679             reply = jsonrpc_create_error(json_string_create("canceled"),
 680                                          t->id);
 681         }
 682         jsonrpc_session_send(s->js, reply);
 683     }
 684
 685     json_destroy(t->id);
 686     ovsdb_trigger_destroy(&t->trigger);
 687     hmap_remove(&s->triggers, &t->hmap_node);
 688     free(t);
 689 }
 690
 691 static void
 692 ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *s)
 693 {
 694     struct ovsdb_jsonrpc_trigger *t, *next;
 695     HMAP_FOR_EACH_SAFE (t, next, hmap_node, &s->triggers) {
 696         ovsdb_jsonrpc_trigger_complete(t);
 697     }
 698 }
 699
 700 static void
 701 ovsdb_jsonrpc_trigger_complete_done(struct ovsdb_jsonrpc_session *s)
 702 {
 703     while (!list_is_empty(&s->completions)) {
 704         struct ovsdb_jsonrpc_trigger *t
 705             = CONTAINER_OF(s->completions.next,
 706                            struct ovsdb_jsonrpc_trigger, trigger.node);
 707         ovsdb_jsonrpc_trigger_complete(t);
 708     }
 709 }
 710 \f
 711 /* JSON-RPC database table monitors. */
 712
 713 enum ovsdb_jsonrpc_monitor_selection {
 714     OJMS_INITIAL = 1 << 0,      /* All rows when monitor is created. */
 715     OJMS_INSERT = 1 << 1,       /* New rows. */
 716     OJMS_DELETE = 1 << 2,       /* Deleted rows. */
 717     OJMS_MODIFY = 1 << 3        /* Modified rows. */
 718 };
 719
 720 /* A particular column being monitored. */
 721 struct ovsdb_jsonrpc_monitor_column {
 722     const struct ovsdb_column *column;
 723     enum ovsdb_jsonrpc_monitor_selection select;
 724 };
 725
 726 /* A particular table being monitored. */
 727 struct ovsdb_jsonrpc_monitor_table {
 728     const struct ovsdb_table *table;
 729
 730     /* This is the union (bitwise-OR) of the 'select' values in all of the
 731      * members of 'columns' below. */
 732     enum ovsdb_jsonrpc_monitor_selection select;
 733
 734     /* Columns being monitored. */
 735     struct ovsdb_jsonrpc_monitor_column *columns;
 736     size_t n_columns;
 737 };
 738
 739 /* A collection of tables being monitored. */
 740 struct ovsdb_jsonrpc_monitor {
 741     struct ovsdb_replica replica;
 742     struct ovsdb_jsonrpc_session *session;
 743     struct hmap_node node;      /* In ovsdb_jsonrpc_session's "monitors". */
 744
 745     struct json *monitor_id;
 746     struct shash tables;     /* Holds "struct ovsdb_jsonrpc_monitor_table"s. */
 747 };
 748
 749 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class;
 750
 751 struct ovsdb_jsonrpc_monitor *ovsdb_jsonrpc_monitor_find(
 752     struct ovsdb_jsonrpc_session *, const struct json *monitor_id);
 753 static void ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *);
 754 static struct json *ovsdb_jsonrpc_monitor_get_initial(
 755     const struct ovsdb_jsonrpc_monitor *);
 756
 757 static bool
 758 parse_bool(struct ovsdb_parser *parser, const char *name, bool default_value)
 759 {
 760     const struct json *json;
 761
 762     json = ovsdb_parser_member(parser, name, OP_BOOLEAN | OP_OPTIONAL);
 763     return json ? json_boolean(json) : default_value;
 764 }
 765
 766 struct ovsdb_jsonrpc_monitor *
 767 ovsdb_jsonrpc_monitor_find(struct ovsdb_jsonrpc_session *s,
 768                            const struct json *monitor_id)
 769 {
 770     struct ovsdb_jsonrpc_monitor *m;
 771
 772     HMAP_FOR_EACH_WITH_HASH (m, node, json_hash(monitor_id, 0), &s->monitors) {
 773         if (json_equal(m->monitor_id, monitor_id)) {
 774             return m;
 775         }
 776     }
 777
 778     return NULL;
 779 }
 780
 781 static void
 782 ovsdb_jsonrpc_add_monitor_column(struct ovsdb_jsonrpc_monitor_table *mt,
 783                                  const struct ovsdb_column *column,
 784                                  enum ovsdb_jsonrpc_monitor_selection select,
 785                                  size_t *allocated_columns)
 786 {
 787     struct ovsdb_jsonrpc_monitor_column *c;
 788
 789     if (mt->n_columns >= *allocated_columns) {
 790         mt->columns = x2nrealloc(mt->columns, allocated_columns,
 791                                  sizeof *mt->columns);
 792     }
 793
 794     c = &mt->columns[mt->n_columns++];
 795     c->column = column;
 796     c->select = select;
 797 }
 798
 799 static int
 800 compare_ovsdb_jsonrpc_monitor_column(const void *a_, const void *b_)
 801 {
 802     const struct ovsdb_jsonrpc_monitor_column *a = a_;
 803     const struct ovsdb_jsonrpc_monitor_column *b = b_;
 804
 805     return a->column < b->column ? -1 : a->column > b->column;
 806 }
 807
 808 static struct ovsdb_error * WARN_UNUSED_RESULT
 809 ovsdb_jsonrpc_parse_monitor_request(struct ovsdb_jsonrpc_monitor_table *mt,
 810                                     const struct json *monitor_request,
 811                                     size_t *allocated_columns)
 812 {
 813     const struct ovsdb_table_schema *ts = mt->table->schema;
 814     enum ovsdb_jsonrpc_monitor_selection select;
 815     const struct json *columns, *select_json;
 816     struct ovsdb_parser parser;
 817     struct ovsdb_error *error;
 818
 819     ovsdb_parser_init(&parser, monitor_request, "table %s", ts->name);
 820     columns = ovsdb_parser_member(&parser, "columns", OP_ARRAY | OP_OPTIONAL);
 821     select_json = ovsdb_parser_member(&parser, "select",
 822                                       OP_OBJECT | OP_OPTIONAL);
 823     error = ovsdb_parser_finish(&parser);
 824     if (error) {
 825         return error;
 826     }
 827
 828     if (select_json) {
 829         select = 0;
 830         ovsdb_parser_init(&parser, select_json, "table %s select", ts->name);
 831         if (parse_bool(&parser, "initial", true)) {
 832             select |= OJMS_INITIAL;
 833         }
 834         if (parse_bool(&parser, "insert", true)) {
 835             select |= OJMS_INSERT;
 836         }
 837         if (parse_bool(&parser, "delete", true)) {
 838             select |= OJMS_DELETE;
 839         }
 840         if (parse_bool(&parser, "modify", true)) {
 841             select |= OJMS_MODIFY;
 842         }
 843         error = ovsdb_parser_finish(&parser);
 844         if (error) {
 845             return error;
 846         }
 847     } else {
 848         select = OJMS_INITIAL | OJMS_INSERT | OJMS_DELETE | OJMS_MODIFY;
 849     }
 850     mt->select |= select;
 851
 852     if (columns) {
 853         size_t i;
 854
 855         if (columns->type != JSON_ARRAY) {
 856             return ovsdb_syntax_error(columns, NULL,
 857                                       "array of column names expected");
 858         }
 859
 860         for (i = 0; i < columns->u.array.n; i++) {
 861             const struct ovsdb_column *column;
 862             const char *s;
 863
 864             if (columns->u.array.elems[i]->type != JSON_STRING) {
 865                 return ovsdb_syntax_error(columns, NULL,
 866                                           "array of column names expected");
 867             }
 868
 869             s = columns->u.array.elems[i]->u.string;
 870             column = shash_find_data(&mt->table->schema->columns, s);
 871             if (!column) {
 872                 return ovsdb_syntax_error(columns, NULL, "%s is not a valid "
 873                                           "column name", s);
 874             }
 875             ovsdb_jsonrpc_add_monitor_column(mt, column, select,
 876                                              allocated_columns);
 877         }
 878     } else {
 879         struct shash_node *node;
 880
 881         SHASH_FOR_EACH (node, &ts->columns) {
 882             const struct ovsdb_column *column = node->data;
 883             if (column->index != OVSDB_COL_UUID) {
 884                 ovsdb_jsonrpc_add_monitor_column(mt, column, select,
 885                                                  allocated_columns);
 886             }
 887         }
 888     }
 889
 890     return NULL;
 891 }
 892
 893 static struct json *
 894 ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s,
 895                              struct json *params)
 896 {
 897     struct ovsdb_jsonrpc_monitor *m = NULL;
 898     struct json *monitor_id, *monitor_requests;
 899     struct ovsdb_error *error = NULL;
 900     struct shash_node *node;
 901     struct json *json;
 902
 903     if (json_array(params)->n != 3) {
 904         error = ovsdb_syntax_error(params, NULL, "invalid parameters");
 905         goto error;
 906     }
 907     monitor_id = params->u.array.elems[1];
 908     monitor_requests = params->u.array.elems[2];
 909     if (monitor_requests->type != JSON_OBJECT) {
 910         error = ovsdb_syntax_error(monitor_requests, NULL,
 911                                    "monitor-requests must be object");
 912         goto error;
 913     }
 914
 915     if (ovsdb_jsonrpc_monitor_find(s, monitor_id)) {
 916         error = ovsdb_syntax_error(monitor_id, NULL, "duplicate monitor ID");
 917         goto error;
 918     }
 919
 920     m = xzalloc(sizeof *m);
 921     ovsdb_replica_init(&m->replica, &ovsdb_jsonrpc_replica_class);
 922     ovsdb_add_replica(s->remote->server->db, &m->replica);
 923     m->session = s;
 924     hmap_insert(&s->monitors, &m->node, json_hash(monitor_id, 0));
 925     m->monitor_id = json_clone(monitor_id);
 926     shash_init(&m->tables);
 927
 928     SHASH_FOR_EACH (node, json_object(monitor_requests)) {
 929         const struct ovsdb_table *table;
 930         struct ovsdb_jsonrpc_monitor_table *mt;
 931         size_t allocated_columns;
 932         const struct json *mr_value;
 933         size_t i;
 934
 935         table = ovsdb_get_table(s->remote->server->db, node->name);
 936         if (!table) {
 937             error = ovsdb_syntax_error(NULL, NULL,
 938                                        "no table named %s", node->name);
 939             goto error;
 940         }
 941
 942         mt = xzalloc(sizeof *mt);
 943         mt->table = table;
 944         shash_add(&m->tables, table->schema->name, mt);
 945
 946         /* Parse columns. */
 947         mr_value = node->data;
 948         allocated_columns = 0;
 949         if (mr_value->type == JSON_ARRAY) {
 950             const struct json_array *array = &mr_value->u.array;
 951
 952             for (i = 0; i < array->n; i++) {
 953                 error = ovsdb_jsonrpc_parse_monitor_request(
 954                     mt, array->elems[i], &allocated_columns);
 955                 if (error) {
 956                     goto error;
 957                 }
 958             }
 959         } else {
 960             error = ovsdb_jsonrpc_parse_monitor_request(
 961                 mt, mr_value, &allocated_columns);
 962             if (error) {
 963                 goto error;
 964             }
 965         }
 966
 967         /* Check for duplicate columns. */
 968         qsort(mt->columns, mt->n_columns, sizeof *mt->columns,
 969               compare_ovsdb_jsonrpc_monitor_column);
 970         for (i = 1; i < mt->n_columns; i++) {
 971             if (mt->columns[i].column == mt->columns[i - 1].column) {
 972                 error = ovsdb_syntax_error(mr_value, NULL, "column %s "
 973                                            "mentioned more than once",
 974                                            mt->columns[i].column->name);
 975                 goto error;
 976             }
 977         }
 978     }
 979
 980     return ovsdb_jsonrpc_monitor_get_initial(m);
 981
 982 error:
 983     if (m) {
 984         ovsdb_remove_replica(s->remote->server->db, &m->replica);
 985     }
 986
 987     json = ovsdb_error_to_json(error);
 988     ovsdb_error_destroy(error);
 989     return json;
 990 }
 991
 992 static struct jsonrpc_msg *
 993 ovsdb_jsonrpc_monitor_cancel(struct ovsdb_jsonrpc_session *s,
 994                              struct json_array *params,
 995                              const struct json *request_id)
 996 {
 997     if (params->n != 1) {
 998         return jsonrpc_create_error(json_string_create("invalid parameters"),
 999                                     request_id);
1000     } else {
1001         struct ovsdb_jsonrpc_monitor *m;
1002
1003         m = ovsdb_jsonrpc_monitor_find(s, params->elems[0]);
1004         if (!m) {
1005             return jsonrpc_create_error(json_string_create("unknown monitor"),
1006                                         request_id);
1007         } else {
1008             ovsdb_remove_replica(s->remote->server->db, &m->replica);
1009             return jsonrpc_create_reply(json_object_create(), request_id);
1010         }
1011     }
1012 }
1013
1014 static void
1015 ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *s)
1016 {
1017     struct ovsdb_jsonrpc_monitor *m, *next;
1018
1019     HMAP_FOR_EACH_SAFE (m, next, node, &s->monitors) {
1020         ovsdb_remove_replica(s->remote->server->db, &m->replica);
1021     }
1022 }
1023
1024 static struct ovsdb_jsonrpc_monitor *
1025 ovsdb_jsonrpc_monitor_cast(struct ovsdb_replica *replica)
1026 {
1027     assert(replica->class == &ovsdb_jsonrpc_replica_class);
1028     return CONTAINER_OF(replica, struct ovsdb_jsonrpc_monitor, replica);
1029 }
1030
1031 struct ovsdb_jsonrpc_monitor_aux {
1032     bool initial;               /* Sending initial contents of table? */
1033     const struct ovsdb_jsonrpc_monitor *monitor;
1034     struct json *json;          /* JSON for the whole transaction. */
1035
1036     /* Current table.  */
1037     struct ovsdb_jsonrpc_monitor_table *mt;
1038     struct json *table_json;    /* JSON for table's transaction. */
1039 };
1040
1041 static bool
1042 any_reportable_change(const struct ovsdb_jsonrpc_monitor_table *mt,
1043                       const unsigned long int *changed)
1044 {
1045     size_t i;
1046
1047     for (i = 0; i < mt->n_columns; i++) {
1048         const struct ovsdb_jsonrpc_monitor_column *c = &mt->columns[i];
1049         unsigned int idx = c->column->index;
1050
1051         if (c->select & OJMS_MODIFY && bitmap_is_set(changed, idx)) {
1052             return true;
1053         }
1054     }
1055
1056     return false;
1057 }
1058
1059 static bool
1060 ovsdb_jsonrpc_monitor_change_cb(const struct ovsdb_row *old,
1061                                 const struct ovsdb_row *new,
1062                                 const unsigned long int *changed,
1063                                 void *aux_)
1064 {
1065     struct ovsdb_jsonrpc_monitor_aux *aux = aux_;
1066     const struct ovsdb_jsonrpc_monitor *m = aux->monitor;
1067     struct ovsdb_table *table = new ? new->table : old->table;
1068     enum ovsdb_jsonrpc_monitor_selection type;
1069     struct json *old_json, *new_json;
1070     struct json *row_json;
1071     char uuid[UUID_LEN + 1];
1072     size_t i;
1073
1074     if (!aux->mt || table != aux->mt->table) {
1075         aux->mt = shash_find_data(&m->tables, table->schema->name);
1076         aux->table_json = NULL;
1077         if (!aux->mt) {
1078             /* We don't care about rows in this table at all.  Tell the caller
1079              * to skip it.  */
1080             return false;
1081         }
1082     }
1083
1084     type = (aux->initial ? OJMS_INITIAL
1085             : !old ? OJMS_INSERT
1086             : !new ? OJMS_DELETE
1087             : OJMS_MODIFY);
1088     if (!(aux->mt->select & type)) {
1089         /* We don't care about this type of change (but do want to be called
1090          * back for changes to other rows in the same table). */
1091         return true;
1092     }
1093
1094     if (type == OJMS_MODIFY && !any_reportable_change(aux->mt, changed)) {
1095         /* Nothing of interest changed. */
1096         return true;
1097     }
1098
1099     old_json = new_json = NULL;
1100     if (type & (OJMS_DELETE | OJMS_MODIFY)) {
1101         old_json = json_object_create();
1102     }
1103     if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
1104         new_json = json_object_create();
1105     }
1106     for (i = 0; i < aux->mt->n_columns; i++) {
1107         const struct ovsdb_jsonrpc_monitor_column *c = &aux->mt->columns[i];
1108         const struct ovsdb_column *column = c->column;
1109         unsigned int idx = c->column->index;
1110
1111         if (!(type & c->select)) {
1112             /* We don't care about this type of change for this particular
1113              * column (but we will care about it for some other column). */
1114             continue;
1115         }
1116
1117         if ((type == OJMS_MODIFY && bitmap_is_set(changed, idx))
1118             || type == OJMS_DELETE) {
1119             json_object_put(old_json, column->name,
1120                             ovsdb_datum_to_json(&old->fields[idx],
1121                                                 &column->type));
1122         }
1123         if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
1124             json_object_put(new_json, column->name,
1125                             ovsdb_datum_to_json(&new->fields[idx],
1126                                                 &column->type));
1127         }
1128     }
1129
1130     /* Create JSON object for transaction overall. */
1131     if (!aux->json) {
1132         aux->json = json_object_create();
1133     }
1134
1135     /* Create JSON object for transaction on this table. */
1136     if (!aux->table_json) {
1137         aux->table_json = json_object_create();
1138         json_object_put(aux->json, aux->mt->table->schema->name,
1139                         aux->table_json);
1140     }
1141
1142     /* Create JSON object for transaction on this row. */
1143     row_json = json_object_create();
1144     if (old_json) {
1145         json_object_put(row_json, "old", old_json);
1146     }
1147     if (new_json) {
1148         json_object_put(row_json, "new", new_json);
1149     }
1150
1151     /* Add JSON row to JSON table. */
1152     snprintf(uuid, sizeof uuid,
1153              UUID_FMT, UUID_ARGS(ovsdb_row_get_uuid(new ? new : old)));
1154     json_object_put(aux->table_json, uuid, row_json);
1155
1156     return true;
1157 }
1158
1159 static void
1160 ovsdb_jsonrpc_monitor_init_aux(struct ovsdb_jsonrpc_monitor_aux *aux,
1161                                const struct ovsdb_jsonrpc_monitor *m,
1162                                bool initial)
1163 {
1164     aux->initial = initial;
1165     aux->monitor = m;
1166     aux->json = NULL;
1167     aux->mt = NULL;
1168     aux->table_json = NULL;
1169 }
1170
1171 static struct ovsdb_error *
1172 ovsdb_jsonrpc_monitor_commit(struct ovsdb_replica *replica,
1173                              const struct ovsdb_txn *txn,
1174                              bool durable OVS_UNUSED)
1175 {
1176     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1177     struct ovsdb_jsonrpc_monitor_aux aux;
1178
1179     ovsdb_jsonrpc_monitor_init_aux(&aux, m, false);
1180     ovsdb_txn_for_each_change(txn, ovsdb_jsonrpc_monitor_change_cb, &aux);
1181     if (aux.json) {
1182         struct jsonrpc_msg *msg;
1183         struct json *params;
1184
1185         params = json_array_create_2(json_clone(aux.monitor->monitor_id),
1186                                      aux.json);
1187         msg = jsonrpc_create_notify("update", params);
1188         jsonrpc_session_send(aux.monitor->session->js, msg);
1189     }
1190
1191     return NULL;
1192 }
1193
1194 static struct json *
1195 ovsdb_jsonrpc_monitor_get_initial(const struct ovsdb_jsonrpc_monitor *m)
1196 {
1197     struct ovsdb_jsonrpc_monitor_aux aux;
1198     struct shash_node *node;
1199
1200     ovsdb_jsonrpc_monitor_init_aux(&aux, m, true);
1201     SHASH_FOR_EACH (node, &m->tables) {
1202         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1203
1204         if (mt->select & OJMS_INITIAL) {
1205             struct ovsdb_row *row;
1206
1207             HMAP_FOR_EACH (row, hmap_node, &mt->table->rows) {
1208                 ovsdb_jsonrpc_monitor_change_cb(NULL, row, NULL, &aux);
1209             }
1210         }
1211     }
1212     return aux.json ? aux.json : json_object_create();
1213 }
1214
1215 static void
1216 ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *replica)
1217 {
1218     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1219     struct shash_node *node;
1220
1221     json_destroy(m->monitor_id);
1222     SHASH_FOR_EACH (node, &m->tables) {
1223         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1224         free(mt->columns);
1225         free(mt);
1226     }
1227     shash_destroy(&m->tables);
1228     hmap_remove(&m->session->monitors, &m->node);
1229     free(m);
1230 }
1231
1232 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class = {
1233     ovsdb_jsonrpc_monitor_commit,
1234     ovsdb_jsonrpc_monitor_destroy
1235 };