ovsdb/jsonrpc-server.c

   1 /* Copyright (c) 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include <config.h>
  17
  18 #include "jsonrpc-server.h"
  19
  20 #include <errno.h>
  21
  22 #include "bitmap.h"
  23 #include "column.h"
  24 #include "dynamic-string.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 "server.h"
  33 #include "simap.h"
  34 #include "stream.h"
  35 #include "table.h"
  36 #include "timeval.h"
  37 #include "transaction.h"
  38 #include "trigger.h"
  39 #include "vlog.h"
  40
  41 VLOG_DEFINE_THIS_MODULE(ovsdb_jsonrpc_server);
  42
  43 struct ovsdb_jsonrpc_remote;
  44 struct ovsdb_jsonrpc_session;
  45
  46 /* Message rate-limiting. */
  47 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
  48
  49 /* Sessions. */
  50 static struct ovsdb_jsonrpc_session *ovsdb_jsonrpc_session_create(
  51     struct ovsdb_jsonrpc_remote *, struct jsonrpc_session *);
  52 static void ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *);
  53 static void ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *);
  54 static void ovsdb_jsonrpc_session_get_memory_usage_all(
  55     const struct ovsdb_jsonrpc_remote *, struct simap *usage);
  56 static void ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *);
  57 static void ovsdb_jsonrpc_session_reconnect_all(struct ovsdb_jsonrpc_remote *);
  58 static void ovsdb_jsonrpc_session_set_all_options(
  59     struct ovsdb_jsonrpc_remote *, const struct ovsdb_jsonrpc_options *);
  60 static bool ovsdb_jsonrpc_session_get_status(
  61     const struct ovsdb_jsonrpc_remote *,
  62     struct ovsdb_jsonrpc_remote_status *);
  63 static void ovsdb_jsonrpc_session_unlock_all(struct ovsdb_jsonrpc_session *);
  64 static void ovsdb_jsonrpc_session_unlock__(struct ovsdb_lock_waiter *);
  65
  66 /* Triggers. */
  67 static void ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *,
  68                                          struct ovsdb *,
  69                                          struct json *id, struct json *params);
  70 static struct ovsdb_jsonrpc_trigger *ovsdb_jsonrpc_trigger_find(
  71     struct ovsdb_jsonrpc_session *, const struct json *id, size_t hash);
  72 static void ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *);
  73 static void ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *);
  74 static void ovsdb_jsonrpc_trigger_complete_done(
  75     struct ovsdb_jsonrpc_session *);
  76
  77 /* Monitors. */
  78 static struct json *ovsdb_jsonrpc_monitor_create(
  79     struct ovsdb_jsonrpc_session *, struct ovsdb *, struct json *params);
  80 static struct jsonrpc_msg *ovsdb_jsonrpc_monitor_cancel(
  81     struct ovsdb_jsonrpc_session *,
  82     struct json_array *params,
  83     const struct json *request_id);
  84 static void ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *);
  85 static size_t ovsdb_jsonrpc_monitor_json_length_all(
  86     struct ovsdb_jsonrpc_session *);
  87 \f
  88 /* JSON-RPC database server. */
  89
  90 struct ovsdb_jsonrpc_server {
  91     struct ovsdb_server up;
  92     unsigned int n_sessions, max_sessions;
  93     struct shash remotes;      /* Contains "struct ovsdb_jsonrpc_remote *"s. */
  94 };
  95
  96 /* A configured remote.  This is either a passive stream listener plus a list
  97  * of the currently connected sessions, or a list of exactly one active
  98  * session. */
  99 struct ovsdb_jsonrpc_remote {
 100     struct ovsdb_jsonrpc_server *server;
 101     struct pstream *listener;   /* Listener, if passive. */
 102     struct list sessions;       /* List of "struct ovsdb_jsonrpc_session"s. */
 103     uint8_t dscp;
 104 };
 105
 106 static struct ovsdb_jsonrpc_remote *ovsdb_jsonrpc_server_add_remote(
 107     struct ovsdb_jsonrpc_server *, const char *name,
 108     const struct ovsdb_jsonrpc_options *options
 109 );
 110 static void ovsdb_jsonrpc_server_del_remote(struct shash_node *);
 111
 112 /* Creates and returns a new server to provide JSON-RPC access to an OVSDB.
 113  *
 114  * The caller must call ovsdb_jsonrpc_server_add_db() for each database to
 115  * which 'server' should provide access. */
 116 struct ovsdb_jsonrpc_server *
 117 ovsdb_jsonrpc_server_create(void)
 118 {
 119     struct ovsdb_jsonrpc_server *server = xzalloc(sizeof *server);
 120     ovsdb_server_init(&server->up);
 121     server->max_sessions = 64;
 122     shash_init(&server->remotes);
 123     return server;
 124 }
 125
 126 /* Adds 'db' to the set of databases served out by 'svr'.  Returns true if
 127  * successful, false if 'db''s name is the same as some database already in
 128  * 'server'. */
 129 bool
 130 ovsdb_jsonrpc_server_add_db(struct ovsdb_jsonrpc_server *svr, struct ovsdb *db)
 131 {
 132     /* The OVSDB protocol doesn't have a way to notify a client that a
 133      * database has been added.  If some client tried to use the database
 134      * that we're adding and failed, then forcing it to reconnect seems like
 135      * a reasonable way to make it try again.
 136      *
 137      * If this is too big of a hammer in practice, we could be more selective,
 138      * e.g. disconnect only connections that actually tried to use a database
 139      * with 'db''s name. */
 140     ovsdb_jsonrpc_server_reconnect(svr);
 141
 142     return ovsdb_server_add_db(&svr->up, db);
 143 }
 144
 145 /* Removes 'db' from the set of databases served out by 'svr'.  Returns
 146  * true if successful, false if there is no database associated with 'db'. */
 147 bool
 148 ovsdb_jsonrpc_server_remove_db(struct ovsdb_jsonrpc_server *svr,
 149                                struct ovsdb *db)
 150 {
 151     /* There might be pointers to 'db' from 'svr', such as monitors or
 152      * outstanding transactions.  Disconnect all JSON-RPC connections to avoid
 153      * accesses to freed memory.
 154      *
 155      * If this is too big of a hammer in practice, we could be more selective,
 156      * e.g. disconnect only connections that actually reference 'db'. */
 157     ovsdb_jsonrpc_server_reconnect(svr);
 158
 159     return ovsdb_server_remove_db(&svr->up, db);
 160 }
 161
 162 void
 163 ovsdb_jsonrpc_server_destroy(struct ovsdb_jsonrpc_server *svr)
 164 {
 165     struct shash_node *node, *next;
 166
 167     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
 168         ovsdb_jsonrpc_server_del_remote(node);
 169     }
 170     shash_destroy(&svr->remotes);
 171     ovsdb_server_destroy(&svr->up);
 172     free(svr);
 173 }
 174
 175 struct ovsdb_jsonrpc_options *
 176 ovsdb_jsonrpc_default_options(const char *target)
 177 {
 178     struct ovsdb_jsonrpc_options *options = xzalloc(sizeof *options);
 179     options->max_backoff = RECONNECT_DEFAULT_MAX_BACKOFF;
 180     options->probe_interval = (stream_or_pstream_needs_probes(target)
 181                                ? RECONNECT_DEFAULT_PROBE_INTERVAL
 182                                : 0);
 183     return options;
 184 }
 185
 186 /* Sets 'svr''s current set of remotes to the names in 'new_remotes', with
 187  * options in the struct ovsdb_jsonrpc_options supplied as the data values.
 188  *
 189  * A remote is an active or passive stream connection method, e.g. "pssl:" or
 190  * "tcp:1.2.3.4". */
 191 void
 192 ovsdb_jsonrpc_server_set_remotes(struct ovsdb_jsonrpc_server *svr,
 193                                  const struct shash *new_remotes)
 194 {
 195     struct shash_node *node, *next;
 196
 197     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
 198         if (!shash_find(new_remotes, node->name)) {
 199             VLOG_INFO("%s: remote deconfigured", node->name);
 200             ovsdb_jsonrpc_server_del_remote(node);
 201         }
 202     }
 203     SHASH_FOR_EACH (node, new_remotes) {
 204         const struct ovsdb_jsonrpc_options *options = node->data;
 205         struct ovsdb_jsonrpc_remote *remote;
 206
 207         remote = shash_find_data(&svr->remotes, node->name);
 208         if (!remote) {
 209             remote = ovsdb_jsonrpc_server_add_remote(svr, node->name, options);
 210             if (!remote) {
 211                 continue;
 212             }
 213         }
 214
 215         ovsdb_jsonrpc_session_set_all_options(remote, options);
 216     }
 217 }
 218
 219 static struct ovsdb_jsonrpc_remote *
 220 ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *svr,
 221                                 const char *name,
 222                                 const struct ovsdb_jsonrpc_options *options)
 223 {
 224     struct ovsdb_jsonrpc_remote *remote;
 225     struct pstream *listener;
 226     int error;
 227
 228     error = jsonrpc_pstream_open(name, &listener, options->dscp);
 229     if (error && error != EAFNOSUPPORT) {
 230         VLOG_ERR_RL(&rl, "%s: listen failed: %s", name, strerror(error));
 231         return NULL;
 232     }
 233
 234     remote = xmalloc(sizeof *remote);
 235     remote->server = svr;
 236     remote->listener = listener;
 237     list_init(&remote->sessions);
 238     remote->dscp = options->dscp;
 239     shash_add(&svr->remotes, name, remote);
 240
 241     if (!listener) {
 242         ovsdb_jsonrpc_session_create(remote, jsonrpc_session_open(name, true));
 243     }
 244     return remote;
 245 }
 246
 247 static void
 248 ovsdb_jsonrpc_server_del_remote(struct shash_node *node)
 249 {
 250     struct ovsdb_jsonrpc_remote *remote = node->data;
 251
 252     ovsdb_jsonrpc_session_close_all(remote);
 253     pstream_close(remote->listener);
 254     shash_delete(&remote->server->remotes, node);
 255     free(remote);
 256 }
 257
 258 /* Stores status information for the remote named 'target', which should have
 259  * been configured on 'svr' with a call to ovsdb_jsonrpc_server_set_remotes(),
 260  * into '*status'.  On success returns true, on failure (if 'svr' doesn't have
 261  * a remote named 'target' or if that remote is an inbound remote that has no
 262  * active connections) returns false.  On failure, 'status' will be zeroed.
 263  */
 264 bool
 265 ovsdb_jsonrpc_server_get_remote_status(
 266     const struct ovsdb_jsonrpc_server *svr, const char *target,
 267     struct ovsdb_jsonrpc_remote_status *status)
 268 {
 269     const struct ovsdb_jsonrpc_remote *remote;
 270
 271     memset(status, 0, sizeof *status);
 272
 273     remote = shash_find_data(&svr->remotes, target);
 274     return remote && ovsdb_jsonrpc_session_get_status(remote, status);
 275 }
 276
 277 void
 278 ovsdb_jsonrpc_server_free_remote_status(
 279     struct ovsdb_jsonrpc_remote_status *status)
 280 {
 281     free(status->locks_held);
 282     free(status->locks_waiting);
 283     free(status->locks_lost);
 284 }
 285
 286 /* Forces all of the JSON-RPC sessions managed by 'svr' to disconnect and
 287  * reconnect. */
 288 void
 289 ovsdb_jsonrpc_server_reconnect(struct ovsdb_jsonrpc_server *svr)
 290 {
 291     struct shash_node *node;
 292
 293     SHASH_FOR_EACH (node, &svr->remotes) {
 294         struct ovsdb_jsonrpc_remote *remote = node->data;
 295
 296         ovsdb_jsonrpc_session_reconnect_all(remote);
 297     }
 298 }
 299
 300 void
 301 ovsdb_jsonrpc_server_run(struct ovsdb_jsonrpc_server *svr)
 302 {
 303     struct shash_node *node;
 304
 305     SHASH_FOR_EACH (node, &svr->remotes) {
 306         struct ovsdb_jsonrpc_remote *remote = node->data;
 307
 308         if (remote->listener && svr->n_sessions < svr->max_sessions) {
 309             struct stream *stream;
 310             int error;
 311
 312             error = pstream_accept(remote->listener, &stream);
 313             if (!error) {
 314                 struct jsonrpc_session *js;
 315                 js = jsonrpc_session_open_unreliably(jsonrpc_open(stream),
 316                                                      remote->dscp);
 317                 ovsdb_jsonrpc_session_create(remote, js);
 318             } else if (error != EAGAIN) {
 319                 VLOG_WARN_RL(&rl, "%s: accept failed: %s",
 320                              pstream_get_name(remote->listener),
 321                              strerror(error));
 322             }
 323         }
 324
 325         ovsdb_jsonrpc_session_run_all(remote);
 326     }
 327 }
 328
 329 void
 330 ovsdb_jsonrpc_server_wait(struct ovsdb_jsonrpc_server *svr)
 331 {
 332     struct shash_node *node;
 333
 334     SHASH_FOR_EACH (node, &svr->remotes) {
 335         struct ovsdb_jsonrpc_remote *remote = node->data;
 336
 337         if (remote->listener && svr->n_sessions < svr->max_sessions) {
 338             pstream_wait(remote->listener);
 339         }
 340
 341         ovsdb_jsonrpc_session_wait_all(remote);
 342     }
 343 }
 344
 345 /* Adds some memory usage statistics for 'svr' into 'usage', for use with
 346  * memory_report(). */
 347 void
 348 ovsdb_jsonrpc_server_get_memory_usage(const struct ovsdb_jsonrpc_server *svr,
 349                                       struct simap *usage)
 350 {
 351     struct shash_node *node;
 352
 353     simap_increase(usage, "sessions", svr->n_sessions);
 354     SHASH_FOR_EACH (node, &svr->remotes) {
 355         struct ovsdb_jsonrpc_remote *remote = node->data;
 356
 357         ovsdb_jsonrpc_session_get_memory_usage_all(remote, usage);
 358     }
 359 }
 360 \f
 361 /* JSON-RPC database server session. */
 362
 363 struct ovsdb_jsonrpc_session {
 364     struct list node;           /* Element in remote's sessions list. */
 365     struct ovsdb_session up;
 366     struct ovsdb_jsonrpc_remote *remote;
 367     size_t backlog_threshold;   /* See ovsdb_jsonrpc_session_run(). */
 368     size_t reply_backlog;
 369
 370     /* Triggers. */
 371     struct hmap triggers;       /* Hmap of "struct ovsdb_jsonrpc_trigger"s. */
 372
 373     /* Monitors. */
 374     struct hmap monitors;       /* Hmap of "struct ovsdb_jsonrpc_monitor"s. */
 375
 376     /* Network connectivity. */
 377     struct jsonrpc_session *js;  /* JSON-RPC session. */
 378     unsigned int js_seqno;       /* Last jsonrpc_session_get_seqno() value. */
 379 };
 380
 381 static void ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *);
 382 static int ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *);
 383 static void ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *);
 384 static void ovsdb_jsonrpc_session_get_memory_usage(
 385     const struct ovsdb_jsonrpc_session *, struct simap *usage);
 386 static void ovsdb_jsonrpc_session_set_options(
 387     struct ovsdb_jsonrpc_session *, const struct ovsdb_jsonrpc_options *);
 388 static void ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *,
 389                                              struct jsonrpc_msg *);
 390 static void ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *,
 391                                              struct jsonrpc_msg *);
 392
 393 static struct ovsdb_jsonrpc_session *
 394 ovsdb_jsonrpc_session_create(struct ovsdb_jsonrpc_remote *remote,
 395                              struct jsonrpc_session *js)
 396 {
 397     struct ovsdb_jsonrpc_session *s;
 398
 399     s = xzalloc(sizeof *s);
 400     ovsdb_session_init(&s->up, &remote->server->up);
 401     s->remote = remote;
 402     list_push_back(&remote->sessions, &s->node);
 403     hmap_init(&s->triggers);
 404     hmap_init(&s->monitors);
 405     s->reply_backlog = 0;
 406     s->backlog_threshold = 1024 * 1024;
 407     s->js = js;
 408     s->js_seqno = jsonrpc_session_get_seqno(js);
 409
 410     remote->server->n_sessions++;
 411
 412     return s;
 413 }
 414
 415 static void
 416 ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *s)
 417 {
 418     ovsdb_jsonrpc_monitor_remove_all(s);
 419     ovsdb_jsonrpc_session_unlock_all(s);
 420     ovsdb_jsonrpc_trigger_complete_all(s);
 421
 422     hmap_destroy(&s->monitors);
 423     hmap_destroy(&s->triggers);
 424
 425     jsonrpc_session_close(s->js);
 426     list_remove(&s->node);
 427     s->remote->server->n_sessions--;
 428     ovsdb_session_destroy(&s->up);
 429     free(s);
 430 }
 431
 432 static int
 433 ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *s)
 434 {
 435     size_t backlog;
 436
 437     jsonrpc_session_run(s->js);
 438     if (s->js_seqno != jsonrpc_session_get_seqno(s->js)) {
 439         s->js_seqno = jsonrpc_session_get_seqno(s->js);
 440         ovsdb_jsonrpc_trigger_complete_all(s);
 441         ovsdb_jsonrpc_monitor_remove_all(s);
 442         ovsdb_jsonrpc_session_unlock_all(s);
 443     }
 444
 445     ovsdb_jsonrpc_trigger_complete_done(s);
 446
 447     backlog = jsonrpc_session_get_backlog(s->js);
 448     if (!backlog) {
 449         struct jsonrpc_msg *msg = jsonrpc_session_recv(s->js);
 450         if (msg) {
 451             if (msg->type == JSONRPC_REQUEST) {
 452                 ovsdb_jsonrpc_session_got_request(s, msg);
 453             } else if (msg->type == JSONRPC_NOTIFY) {
 454                 ovsdb_jsonrpc_session_got_notify(s, msg);
 455             } else {
 456                 VLOG_WARN("%s: received unexpected %s message",
 457                           jsonrpc_session_get_name(s->js),
 458                           jsonrpc_msg_type_to_string(msg->type));
 459                 jsonrpc_session_force_reconnect(s->js);
 460                 jsonrpc_msg_destroy(msg);
 461             }
 462         }
 463         s->reply_backlog = jsonrpc_session_get_backlog(s->js);
 464     } else if (backlog > s->reply_backlog + s->backlog_threshold) {
 465         /* We have a lot of data queued to send to the client.  The data is
 466          * likely to be mostly monitor updates.  It is unlikely that the
 467          * monitor updates are due to transactions by 's', because we will not
 468          * let 's' make any more transactions until it drains its backlog to 0
 469          * (see previous 'if' case).  So the monitor updates are probably due
 470          * to transactions made by database clients other than 's'.  We can't
 471          * fix that by preventing 's' from executing more transactions.  We
 472          * could fix it by preventing every client from executing transactions,
 473          * but then one slow or hung client could prevent other clients from
 474          * doing useful work.
 475          *
 476          * Our solution is to cap the maximum backlog to O(1) in the amount of
 477          * data in the database.  If the backlog exceeds that amount, then we
 478          * disconnect the client.  When it reconnects, it can fetch the entire
 479          * contents of the database using less data than was previously
 480          * backlogged. */
 481         size_t monitor_length;
 482
 483         monitor_length = ovsdb_jsonrpc_monitor_json_length_all(s);
 484         if (backlog > s->reply_backlog + monitor_length * 2) {
 485             VLOG_INFO("%s: %zu bytes backlogged but a complete replica "
 486                       "would only take %zu bytes, disconnecting",
 487                       jsonrpc_session_get_name(s->js),
 488                       backlog - s->reply_backlog, monitor_length);
 489             jsonrpc_session_force_reconnect(s->js);
 490         } else {
 491             /* The backlog is not unreasonably big.  Only check again after it
 492              * becomes much bigger. */
 493             s->backlog_threshold = 2 * MAX(s->backlog_threshold * 2,
 494                                            monitor_length);
 495         }
 496     }
 497     return jsonrpc_session_is_alive(s->js) ? 0 : ETIMEDOUT;
 498 }
 499
 500 static void
 501 ovsdb_jsonrpc_session_set_options(struct ovsdb_jsonrpc_session *session,
 502                                   const struct ovsdb_jsonrpc_options *options)
 503 {
 504     jsonrpc_session_set_max_backoff(session->js, options->max_backoff);
 505     jsonrpc_session_set_probe_interval(session->js, options->probe_interval);
 506     jsonrpc_session_set_dscp(session->js, options->dscp);
 507 }
 508
 509 static void
 510 ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *remote)
 511 {
 512     struct ovsdb_jsonrpc_session *s, *next;
 513
 514     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
 515         int error = ovsdb_jsonrpc_session_run(s);
 516         if (error) {
 517             ovsdb_jsonrpc_session_close(s);
 518         }
 519     }
 520 }
 521
 522 static void
 523 ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *s)
 524 {
 525     jsonrpc_session_wait(s->js);
 526     if (!jsonrpc_session_get_backlog(s->js)) {
 527         jsonrpc_session_recv_wait(s->js);
 528     }
 529 }
 530
 531 static void
 532 ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *remote)
 533 {
 534     struct ovsdb_jsonrpc_session *s;
 535
 536     LIST_FOR_EACH (s, node, &remote->sessions) {
 537         ovsdb_jsonrpc_session_wait(s);
 538     }
 539 }
 540
 541 static void
 542 ovsdb_jsonrpc_session_get_memory_usage(const struct ovsdb_jsonrpc_session *s,
 543                                        struct simap *usage)
 544 {
 545     simap_increase(usage, "triggers", hmap_count(&s->triggers));
 546     simap_increase(usage, "monitors", hmap_count(&s->monitors));
 547     simap_increase(usage, "backlog", jsonrpc_session_get_backlog(s->js));
 548 }
 549
 550 static void
 551 ovsdb_jsonrpc_session_get_memory_usage_all(
 552     const struct ovsdb_jsonrpc_remote *remote,
 553     struct simap *usage)
 554 {
 555     struct ovsdb_jsonrpc_session *s;
 556
 557     LIST_FOR_EACH (s, node, &remote->sessions) {
 558         ovsdb_jsonrpc_session_get_memory_usage(s, usage);
 559     }
 560 }
 561
 562 static void
 563 ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *remote)
 564 {
 565     struct ovsdb_jsonrpc_session *s, *next;
 566
 567     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
 568         ovsdb_jsonrpc_session_close(s);
 569     }
 570 }
 571
 572 /* Forces all of the JSON-RPC sessions managed by 'remote' to disconnect and
 573  * reconnect. */
 574 static void
 575 ovsdb_jsonrpc_session_reconnect_all(struct ovsdb_jsonrpc_remote *remote)
 576 {
 577     struct ovsdb_jsonrpc_session *s, *next;
 578
 579     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
 580         jsonrpc_session_force_reconnect(s->js);
 581         if (!jsonrpc_session_is_alive(s->js)) {
 582             ovsdb_jsonrpc_session_close(s);
 583         }
 584     }
 585 }
 586
 587 /* Sets the options for all of the JSON-RPC sessions managed by 'remote' to
 588  * 'options'. */
 589 static void
 590 ovsdb_jsonrpc_session_set_all_options(
 591     struct ovsdb_jsonrpc_remote *remote,
 592     const struct ovsdb_jsonrpc_options *options)
 593 {
 594     struct ovsdb_jsonrpc_session *s;
 595
 596     if (remote->listener) {
 597         int error;
 598
 599         error = pstream_set_dscp(remote->listener, options->dscp);
 600         if (error) {
 601             VLOG_ERR("%s: set_dscp failed %s",
 602                      pstream_get_name(remote->listener), strerror(error));
 603         } else {
 604             remote->dscp = options->dscp;
 605         }
 606         /*
 607          * XXX race window between setting dscp to listening socket
 608          * and accepting socket. Accepted socket may have old dscp value.
 609          * Ignore this race window for now.
 610          */
 611     }
 612     LIST_FOR_EACH (s, node, &remote->sessions) {
 613         ovsdb_jsonrpc_session_set_options(s, options);
 614     }
 615 }
 616
 617 static bool
 618 ovsdb_jsonrpc_session_get_status(const struct ovsdb_jsonrpc_remote *remote,
 619                                  struct ovsdb_jsonrpc_remote_status *status)
 620 {
 621     const struct ovsdb_jsonrpc_session *s;
 622     const struct jsonrpc_session *js;
 623     struct ovsdb_lock_waiter *waiter;
 624     struct reconnect_stats rstats;
 625     struct ds locks_held, locks_waiting, locks_lost;
 626
 627     status->bound_port = (remote->listener
 628                           ? pstream_get_bound_port(remote->listener)
 629                           : htons(0));
 630
 631     if (list_is_empty(&remote->sessions)) {
 632         return false;
 633     }
 634     s = CONTAINER_OF(remote->sessions.next, struct ovsdb_jsonrpc_session, node);
 635     js = s->js;
 636
 637     status->is_connected = jsonrpc_session_is_connected(js);
 638     status->last_error = jsonrpc_session_get_status(js);
 639
 640     jsonrpc_session_get_reconnect_stats(js, &rstats);
 641     status->state = rstats.state;
 642     status->sec_since_connect = rstats.msec_since_connect == UINT_MAX
 643         ? UINT_MAX : rstats.msec_since_connect / 1000;
 644     status->sec_since_disconnect = rstats.msec_since_disconnect == UINT_MAX
 645         ? UINT_MAX : rstats.msec_since_disconnect / 1000;
 646
 647     ds_init(&locks_held);
 648     ds_init(&locks_waiting);
 649     ds_init(&locks_lost);
 650     HMAP_FOR_EACH (waiter, session_node, &s->up.waiters) {
 651         struct ds *string;
 652
 653         string = (ovsdb_lock_waiter_is_owner(waiter) ? &locks_held
 654                   : waiter->mode == OVSDB_LOCK_WAIT ? &locks_waiting
 655                   : &locks_lost);
 656         if (string->length) {
 657             ds_put_char(string, ' ');
 658         }
 659         ds_put_cstr(string, waiter->lock_name);
 660     }
 661     status->locks_held = ds_steal_cstr(&locks_held);
 662     status->locks_waiting = ds_steal_cstr(&locks_waiting);
 663     status->locks_lost = ds_steal_cstr(&locks_lost);
 664
 665     status->n_connections = list_size(&remote->sessions);
 666
 667     return true;
 668 }
 669
 670 /* Examines 'request' to determine the database to which it relates, and then
 671  * searches 's' to find that database:
 672  *
 673  *    - If successful, returns the database and sets '*replyp' to NULL.
 674  *
 675  *    - If no such database exists, returns NULL and sets '*replyp' to an
 676  *      appropriate JSON-RPC error reply, owned by the caller. */
 677 static struct ovsdb *
 678 ovsdb_jsonrpc_lookup_db(const struct ovsdb_jsonrpc_session *s,
 679                         const struct jsonrpc_msg *request,
 680                         struct jsonrpc_msg **replyp)
 681 {
 682     struct json_array *params;
 683     struct ovsdb_error *error;
 684     const char *db_name;
 685     struct ovsdb *db;
 686
 687     params = json_array(request->params);
 688     if (!params->n || params->elems[0]->type != JSON_STRING) {
 689         error = ovsdb_syntax_error(
 690             request->params, NULL,
 691             "%s request params must begin with <db-name>", request->method);
 692         goto error;
 693     }
 694
 695     db_name = params->elems[0]->u.string;
 696     db = shash_find_data(&s->up.server->dbs, db_name);
 697     if (!db) {
 698         error = ovsdb_syntax_error(
 699             request->params, "unknown database",
 700             "%s request specifies unknown database %s",
 701             request->method, db_name);
 702         goto error;
 703     }
 704
 705     *replyp = NULL;
 706     return db;
 707
 708 error:
 709     *replyp = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
 710     ovsdb_error_destroy(error);
 711     return NULL;
 712 }
 713
 714 static struct ovsdb_error *
 715 ovsdb_jsonrpc_session_parse_lock_name(const struct jsonrpc_msg *request,
 716                                       const char **lock_namep)
 717 {
 718     const struct json_array *params;
 719
 720     params = json_array(request->params);
 721     if (params->n != 1 || params->elems[0]->type != JSON_STRING ||
 722         !ovsdb_parser_is_id(json_string(params->elems[0]))) {
 723         *lock_namep = NULL;
 724         return ovsdb_syntax_error(request->params, NULL,
 725                                   "%s request params must be <id>",
 726                                   request->method);
 727     }
 728
 729     *lock_namep = json_string(params->elems[0]);
 730     return NULL;
 731 }
 732
 733 static void
 734 ovsdb_jsonrpc_session_notify(struct ovsdb_session *session,
 735                              const char *lock_name,
 736                              const char *method)
 737 {
 738     struct ovsdb_jsonrpc_session *s;
 739     struct json *params;
 740
 741     s = CONTAINER_OF(session, struct ovsdb_jsonrpc_session, up);
 742     params = json_array_create_1(json_string_create(lock_name));
 743     jsonrpc_session_send(s->js, jsonrpc_create_notify(method, params));
 744 }
 745
 746 static struct jsonrpc_msg *
 747 ovsdb_jsonrpc_session_lock(struct ovsdb_jsonrpc_session *s,
 748                            struct jsonrpc_msg *request,
 749                            enum ovsdb_lock_mode mode)
 750 {
 751     struct ovsdb_lock_waiter *waiter;
 752     struct jsonrpc_msg *reply;
 753     struct ovsdb_error *error;
 754     struct ovsdb_session *victim;
 755     const char *lock_name;
 756     struct json *result;
 757
 758     error = ovsdb_jsonrpc_session_parse_lock_name(request, &lock_name);
 759     if (error) {
 760         goto error;
 761     }
 762
 763     /* Report error if this session has issued a "lock" or "steal" without a
 764      * matching "unlock" for this lock. */
 765     waiter = ovsdb_session_get_lock_waiter(&s->up, lock_name);
 766     if (waiter) {
 767         error = ovsdb_syntax_error(
 768             request->params, NULL,
 769             "must issue \"unlock\" before new \"%s\"", request->method);
 770         goto error;
 771     }
 772
 773     /* Get the lock, add us as a waiter. */
 774     waiter = ovsdb_server_lock(&s->remote->server->up, &s->up, lock_name, mode,
 775                                &victim);
 776     if (victim) {
 777         ovsdb_jsonrpc_session_notify(victim, lock_name, "stolen");
 778     }
 779
 780     result = json_object_create();
 781     json_object_put(result, "locked",
 782                     json_boolean_create(ovsdb_lock_waiter_is_owner(waiter)));
 783
 784     return jsonrpc_create_reply(result, request->id);
 785
 786 error:
 787     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
 788     ovsdb_error_destroy(error);
 789     return reply;
 790 }
 791
 792 static void
 793 ovsdb_jsonrpc_session_unlock_all(struct ovsdb_jsonrpc_session *s)
 794 {
 795     struct ovsdb_lock_waiter *waiter, *next;
 796
 797     HMAP_FOR_EACH_SAFE (waiter, next, session_node, &s->up.waiters) {
 798         ovsdb_jsonrpc_session_unlock__(waiter);
 799     }
 800 }
 801
 802 static void
 803 ovsdb_jsonrpc_session_unlock__(struct ovsdb_lock_waiter *waiter)
 804 {
 805     struct ovsdb_lock *lock = waiter->lock;
 806
 807     if (lock) {
 808         struct ovsdb_session *new_owner = ovsdb_lock_waiter_remove(waiter);
 809         if (new_owner) {
 810             ovsdb_jsonrpc_session_notify(new_owner, lock->name, "locked");
 811         } else {
 812             /* ovsdb_server_lock() might have freed 'lock'. */
 813         }
 814     }
 815
 816     ovsdb_lock_waiter_destroy(waiter);
 817 }
 818
 819 static struct jsonrpc_msg *
 820 ovsdb_jsonrpc_session_unlock(struct ovsdb_jsonrpc_session *s,
 821                              struct jsonrpc_msg *request)
 822 {
 823     struct ovsdb_lock_waiter *waiter;
 824     struct jsonrpc_msg *reply;
 825     struct ovsdb_error *error;
 826     const char *lock_name;
 827
 828     error = ovsdb_jsonrpc_session_parse_lock_name(request, &lock_name);
 829     if (error) {
 830         goto error;
 831     }
 832
 833     /* Report error if this session has not issued a "lock" or "steal" for this
 834      * lock. */
 835     waiter = ovsdb_session_get_lock_waiter(&s->up, lock_name);
 836     if (!waiter) {
 837         error = ovsdb_syntax_error(
 838             request->params, NULL, "\"unlock\" without \"lock\" or \"steal\"");
 839         goto error;
 840     }
 841
 842     ovsdb_jsonrpc_session_unlock__(waiter);
 843
 844     return jsonrpc_create_reply(json_object_create(), request->id);
 845
 846 error:
 847     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
 848     ovsdb_error_destroy(error);
 849     return reply;
 850 }
 851
 852 static struct jsonrpc_msg *
 853 execute_transaction(struct ovsdb_jsonrpc_session *s, struct ovsdb *db,
 854                     struct jsonrpc_msg *request)
 855 {
 856     ovsdb_jsonrpc_trigger_create(s, db, request->id, request->params);
 857     request->id = NULL;
 858     request->params = NULL;
 859     jsonrpc_msg_destroy(request);
 860     return NULL;
 861 }
 862
 863 static void
 864 ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *s,
 865                                   struct jsonrpc_msg *request)
 866 {
 867     struct jsonrpc_msg *reply;
 868
 869     if (!strcmp(request->method, "transact")) {
 870         struct ovsdb *db = ovsdb_jsonrpc_lookup_db(s, request, &reply);
 871         if (!reply) {
 872             reply = execute_transaction(s, db, request);
 873         }
 874     } else if (!strcmp(request->method, "monitor")) {
 875         struct ovsdb *db = ovsdb_jsonrpc_lookup_db(s, request, &reply);
 876         if (!reply) {
 877             reply = jsonrpc_create_reply(
 878                 ovsdb_jsonrpc_monitor_create(s, db, request->params),
 879                 request->id);
 880         }
 881     } else if (!strcmp(request->method, "monitor_cancel")) {
 882         reply = ovsdb_jsonrpc_monitor_cancel(s, json_array(request->params),
 883                                              request->id);
 884     } else if (!strcmp(request->method, "get_schema")) {
 885         struct ovsdb *db = ovsdb_jsonrpc_lookup_db(s, request, &reply);
 886         if (!reply) {
 887             reply = jsonrpc_create_reply(ovsdb_schema_to_json(db->schema),
 888                                          request->id);
 889         }
 890     } else if (!strcmp(request->method, "list_dbs")) {
 891         size_t n_dbs = shash_count(&s->up.server->dbs);
 892         struct shash_node *node;
 893         struct json **dbs;
 894         size_t i;
 895
 896         dbs = xmalloc(n_dbs * sizeof *dbs);
 897         i = 0;
 898         SHASH_FOR_EACH (node, &s->up.server->dbs) {
 899             dbs[i++] = json_string_create(node->name);
 900         }
 901         reply = jsonrpc_create_reply(json_array_create(dbs, n_dbs),
 902                                      request->id);
 903     } else if (!strcmp(request->method, "lock")) {
 904         reply = ovsdb_jsonrpc_session_lock(s, request, OVSDB_LOCK_WAIT);
 905     } else if (!strcmp(request->method, "steal")) {
 906         reply = ovsdb_jsonrpc_session_lock(s, request, OVSDB_LOCK_STEAL);
 907     } else if (!strcmp(request->method, "unlock")) {
 908         reply = ovsdb_jsonrpc_session_unlock(s, request);
 909     } else if (!strcmp(request->method, "echo")) {
 910         reply = jsonrpc_create_reply(json_clone(request->params), request->id);
 911     } else {
 912         reply = jsonrpc_create_error(json_string_create("unknown method"),
 913                                      request->id);
 914     }
 915
 916     if (reply) {
 917         jsonrpc_msg_destroy(request);
 918         jsonrpc_session_send(s->js, reply);
 919     }
 920 }
 921
 922 static void
 923 execute_cancel(struct ovsdb_jsonrpc_session *s, struct jsonrpc_msg *request)
 924 {
 925     if (json_array(request->params)->n == 1) {
 926         struct ovsdb_jsonrpc_trigger *t;
 927         struct json *id;
 928
 929         id = request->params->u.array.elems[0];
 930         t = ovsdb_jsonrpc_trigger_find(s, id, json_hash(id, 0));
 931         if (t) {
 932             ovsdb_jsonrpc_trigger_complete(t);
 933         }
 934     }
 935 }
 936
 937 static void
 938 ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *s,
 939                                  struct jsonrpc_msg *request)
 940 {
 941     if (!strcmp(request->method, "cancel")) {
 942         execute_cancel(s, request);
 943     }
 944     jsonrpc_msg_destroy(request);
 945 }
 946 \f
 947 /* JSON-RPC database server triggers.
 948  *
 949  * (Every transaction is treated as a trigger even if it doesn't actually have
 950  * any "wait" operations.) */
 951
 952 struct ovsdb_jsonrpc_trigger {
 953     struct ovsdb_trigger trigger;
 954     struct hmap_node hmap_node; /* In session's "triggers" hmap. */
 955     struct json *id;
 956 };
 957
 958 static void
 959 ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *s, struct ovsdb *db,
 960                              struct json *id, struct json *params)
 961 {
 962     struct ovsdb_jsonrpc_trigger *t;
 963     size_t hash;
 964
 965     /* Check for duplicate ID. */
 966     hash = json_hash(id, 0);
 967     t = ovsdb_jsonrpc_trigger_find(s, id, hash);
 968     if (t) {
 969         struct jsonrpc_msg *msg;
 970
 971         msg = jsonrpc_create_error(json_string_create("duplicate request ID"),
 972                                    id);
 973         jsonrpc_session_send(s->js, msg);
 974         json_destroy(id);
 975         json_destroy(params);
 976         return;
 977     }
 978
 979     /* Insert into trigger table. */
 980     t = xmalloc(sizeof *t);
 981     ovsdb_trigger_init(&s->up, db, &t->trigger, params, time_msec());
 982     t->id = id;
 983     hmap_insert(&s->triggers, &t->hmap_node, hash);
 984
 985     /* Complete early if possible. */
 986     if (ovsdb_trigger_is_complete(&t->trigger)) {
 987         ovsdb_jsonrpc_trigger_complete(t);
 988     }
 989 }
 990
 991 static struct ovsdb_jsonrpc_trigger *
 992 ovsdb_jsonrpc_trigger_find(struct ovsdb_jsonrpc_session *s,
 993                            const struct json *id, size_t hash)
 994 {
 995     struct ovsdb_jsonrpc_trigger *t;
 996
 997     HMAP_FOR_EACH_WITH_HASH (t, hmap_node, hash, &s->triggers) {
 998         if (json_equal(t->id, id)) {
 999             return t;
1000         }
1001     }
1002
1003     return NULL;
1004 }
1005
1006 static void
1007 ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *t)
1008 {
1009     struct ovsdb_jsonrpc_session *s;
1010
1011     s = CONTAINER_OF(t->trigger.session, struct ovsdb_jsonrpc_session, up);
1012
1013     if (jsonrpc_session_is_connected(s->js)) {
1014         struct jsonrpc_msg *reply;
1015         struct json *result;
1016
1017         result = ovsdb_trigger_steal_result(&t->trigger);
1018         if (result) {
1019             reply = jsonrpc_create_reply(result, t->id);
1020         } else {
1021             reply = jsonrpc_create_error(json_string_create("canceled"),
1022                                          t->id);
1023         }
1024         jsonrpc_session_send(s->js, reply);
1025     }
1026
1027     json_destroy(t->id);
1028     ovsdb_trigger_destroy(&t->trigger);
1029     hmap_remove(&s->triggers, &t->hmap_node);
1030     free(t);
1031 }
1032
1033 static void
1034 ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *s)
1035 {
1036     struct ovsdb_jsonrpc_trigger *t, *next;
1037     HMAP_FOR_EACH_SAFE (t, next, hmap_node, &s->triggers) {
1038         ovsdb_jsonrpc_trigger_complete(t);
1039     }
1040 }
1041
1042 static void
1043 ovsdb_jsonrpc_trigger_complete_done(struct ovsdb_jsonrpc_session *s)
1044 {
1045     while (!list_is_empty(&s->up.completions)) {
1046         struct ovsdb_jsonrpc_trigger *t
1047             = CONTAINER_OF(s->up.completions.next,
1048                            struct ovsdb_jsonrpc_trigger, trigger.node);
1049         ovsdb_jsonrpc_trigger_complete(t);
1050     }
1051 }
1052 \f
1053 /* JSON-RPC database table monitors. */
1054
1055 enum ovsdb_jsonrpc_monitor_selection {
1056     OJMS_INITIAL = 1 << 0,      /* All rows when monitor is created. */
1057     OJMS_INSERT = 1 << 1,       /* New rows. */
1058     OJMS_DELETE = 1 << 2,       /* Deleted rows. */
1059     OJMS_MODIFY = 1 << 3        /* Modified rows. */
1060 };
1061
1062 /* A particular column being monitored. */
1063 struct ovsdb_jsonrpc_monitor_column {
1064     const struct ovsdb_column *column;
1065     enum ovsdb_jsonrpc_monitor_selection select;
1066 };
1067
1068 /* A particular table being monitored. */
1069 struct ovsdb_jsonrpc_monitor_table {
1070     const struct ovsdb_table *table;
1071
1072     /* This is the union (bitwise-OR) of the 'select' values in all of the
1073      * members of 'columns' below. */
1074     enum ovsdb_jsonrpc_monitor_selection select;
1075
1076     /* Columns being monitored. */
1077     struct ovsdb_jsonrpc_monitor_column *columns;
1078     size_t n_columns;
1079 };
1080
1081 /* A collection of tables being monitored. */
1082 struct ovsdb_jsonrpc_monitor {
1083     struct ovsdb_replica replica;
1084     struct ovsdb_jsonrpc_session *session;
1085     struct ovsdb *db;
1086     struct hmap_node node;      /* In ovsdb_jsonrpc_session's "monitors". */
1087
1088     struct json *monitor_id;
1089     struct shash tables;     /* Holds "struct ovsdb_jsonrpc_monitor_table"s. */
1090 };
1091
1092 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class;
1093
1094 struct ovsdb_jsonrpc_monitor *ovsdb_jsonrpc_monitor_find(
1095     struct ovsdb_jsonrpc_session *, const struct json *monitor_id);
1096 static void ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *);
1097 static struct json *ovsdb_jsonrpc_monitor_get_initial(
1098     const struct ovsdb_jsonrpc_monitor *);
1099 static size_t ovsdb_jsonrpc_monitor_json_length(
1100     const struct ovsdb_jsonrpc_monitor *);
1101
1102 static bool
1103 parse_bool(struct ovsdb_parser *parser, const char *name, bool default_value)
1104 {
1105     const struct json *json;
1106
1107     json = ovsdb_parser_member(parser, name, OP_BOOLEAN | OP_OPTIONAL);
1108     return json ? json_boolean(json) : default_value;
1109 }
1110
1111 struct ovsdb_jsonrpc_monitor *
1112 ovsdb_jsonrpc_monitor_find(struct ovsdb_jsonrpc_session *s,
1113                            const struct json *monitor_id)
1114 {
1115     struct ovsdb_jsonrpc_monitor *m;
1116
1117     HMAP_FOR_EACH_WITH_HASH (m, node, json_hash(monitor_id, 0), &s->monitors) {
1118         if (json_equal(m->monitor_id, monitor_id)) {
1119             return m;
1120         }
1121     }
1122
1123     return NULL;
1124 }
1125
1126 static void
1127 ovsdb_jsonrpc_add_monitor_column(struct ovsdb_jsonrpc_monitor_table *mt,
1128                                  const struct ovsdb_column *column,
1129                                  enum ovsdb_jsonrpc_monitor_selection select,
1130                                  size_t *allocated_columns)
1131 {
1132     struct ovsdb_jsonrpc_monitor_column *c;
1133
1134     if (mt->n_columns >= *allocated_columns) {
1135         mt->columns = x2nrealloc(mt->columns, allocated_columns,
1136                                  sizeof *mt->columns);
1137     }
1138
1139     c = &mt->columns[mt->n_columns++];
1140     c->column = column;
1141     c->select = select;
1142 }
1143
1144 static int
1145 compare_ovsdb_jsonrpc_monitor_column(const void *a_, const void *b_)
1146 {
1147     const struct ovsdb_jsonrpc_monitor_column *a = a_;
1148     const struct ovsdb_jsonrpc_monitor_column *b = b_;
1149
1150     return a->column < b->column ? -1 : a->column > b->column;
1151 }
1152
1153 static struct ovsdb_error * WARN_UNUSED_RESULT
1154 ovsdb_jsonrpc_parse_monitor_request(struct ovsdb_jsonrpc_monitor_table *mt,
1155                                     const struct json *monitor_request,
1156                                     size_t *allocated_columns)
1157 {
1158     const struct ovsdb_table_schema *ts = mt->table->schema;
1159     enum ovsdb_jsonrpc_monitor_selection select;
1160     const struct json *columns, *select_json;
1161     struct ovsdb_parser parser;
1162     struct ovsdb_error *error;
1163
1164     ovsdb_parser_init(&parser, monitor_request, "table %s", ts->name);
1165     columns = ovsdb_parser_member(&parser, "columns", OP_ARRAY | OP_OPTIONAL);
1166     select_json = ovsdb_parser_member(&parser, "select",
1167                                       OP_OBJECT | OP_OPTIONAL);
1168     error = ovsdb_parser_finish(&parser);
1169     if (error) {
1170         return error;
1171     }
1172
1173     if (select_json) {
1174         select = 0;
1175         ovsdb_parser_init(&parser, select_json, "table %s select", ts->name);
1176         if (parse_bool(&parser, "initial", true)) {
1177             select |= OJMS_INITIAL;
1178         }
1179         if (parse_bool(&parser, "insert", true)) {
1180             select |= OJMS_INSERT;
1181         }
1182         if (parse_bool(&parser, "delete", true)) {
1183             select |= OJMS_DELETE;
1184         }
1185         if (parse_bool(&parser, "modify", true)) {
1186             select |= OJMS_MODIFY;
1187         }
1188         error = ovsdb_parser_finish(&parser);
1189         if (error) {
1190             return error;
1191         }
1192     } else {
1193         select = OJMS_INITIAL | OJMS_INSERT | OJMS_DELETE | OJMS_MODIFY;
1194     }
1195     mt->select |= select;
1196
1197     if (columns) {
1198         size_t i;
1199
1200         if (columns->type != JSON_ARRAY) {
1201             return ovsdb_syntax_error(columns, NULL,
1202                                       "array of column names expected");
1203         }
1204
1205         for (i = 0; i < columns->u.array.n; i++) {
1206             const struct ovsdb_column *column;
1207             const char *s;
1208
1209             if (columns->u.array.elems[i]->type != JSON_STRING) {
1210                 return ovsdb_syntax_error(columns, NULL,
1211                                           "array of column names expected");
1212             }
1213
1214             s = columns->u.array.elems[i]->u.string;
1215             column = shash_find_data(&mt->table->schema->columns, s);
1216             if (!column) {
1217                 return ovsdb_syntax_error(columns, NULL, "%s is not a valid "
1218                                           "column name", s);
1219             }
1220             ovsdb_jsonrpc_add_monitor_column(mt, column, select,
1221                                              allocated_columns);
1222         }
1223     } else {
1224         struct shash_node *node;
1225
1226         SHASH_FOR_EACH (node, &ts->columns) {
1227             const struct ovsdb_column *column = node->data;
1228             if (column->index != OVSDB_COL_UUID) {
1229                 ovsdb_jsonrpc_add_monitor_column(mt, column, select,
1230                                                  allocated_columns);
1231             }
1232         }
1233     }
1234
1235     return NULL;
1236 }
1237
1238 static struct json *
1239 ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s, struct ovsdb *db,
1240                              struct json *params)
1241 {
1242     struct ovsdb_jsonrpc_monitor *m = NULL;
1243     struct json *monitor_id, *monitor_requests;
1244     struct ovsdb_error *error = NULL;
1245     struct shash_node *node;
1246     struct json *json;
1247
1248     if (json_array(params)->n != 3) {
1249         error = ovsdb_syntax_error(params, NULL, "invalid parameters");
1250         goto error;
1251     }
1252     monitor_id = params->u.array.elems[1];
1253     monitor_requests = params->u.array.elems[2];
1254     if (monitor_requests->type != JSON_OBJECT) {
1255         error = ovsdb_syntax_error(monitor_requests, NULL,
1256                                    "monitor-requests must be object");
1257         goto error;
1258     }
1259
1260     if (ovsdb_jsonrpc_monitor_find(s, monitor_id)) {
1261         error = ovsdb_syntax_error(monitor_id, NULL, "duplicate monitor ID");
1262         goto error;
1263     }
1264
1265     m = xzalloc(sizeof *m);
1266     ovsdb_replica_init(&m->replica, &ovsdb_jsonrpc_replica_class);
1267     ovsdb_add_replica(db, &m->replica);
1268     m->session = s;
1269     m->db = db;
1270     hmap_insert(&s->monitors, &m->node, json_hash(monitor_id, 0));
1271     m->monitor_id = json_clone(monitor_id);
1272     shash_init(&m->tables);
1273
1274     SHASH_FOR_EACH (node, json_object(monitor_requests)) {
1275         const struct ovsdb_table *table;
1276         struct ovsdb_jsonrpc_monitor_table *mt;
1277         size_t allocated_columns;
1278         const struct json *mr_value;
1279         size_t i;
1280
1281         table = ovsdb_get_table(m->db, node->name);
1282         if (!table) {
1283             error = ovsdb_syntax_error(NULL, NULL,
1284                                        "no table named %s", node->name);
1285             goto error;
1286         }
1287
1288         mt = xzalloc(sizeof *mt);
1289         mt->table = table;
1290         shash_add(&m->tables, table->schema->name, mt);
1291
1292         /* Parse columns. */
1293         mr_value = node->data;
1294         allocated_columns = 0;
1295         if (mr_value->type == JSON_ARRAY) {
1296             const struct json_array *array = &mr_value->u.array;
1297
1298             for (i = 0; i < array->n; i++) {
1299                 error = ovsdb_jsonrpc_parse_monitor_request(
1300                     mt, array->elems[i], &allocated_columns);
1301                 if (error) {
1302                     goto error;
1303                 }
1304             }
1305         } else {
1306             error = ovsdb_jsonrpc_parse_monitor_request(
1307                 mt, mr_value, &allocated_columns);
1308             if (error) {
1309                 goto error;
1310             }
1311         }
1312
1313         /* Check for duplicate columns. */
1314         qsort(mt->columns, mt->n_columns, sizeof *mt->columns,
1315               compare_ovsdb_jsonrpc_monitor_column);
1316         for (i = 1; i < mt->n_columns; i++) {
1317             if (mt->columns[i].column == mt->columns[i - 1].column) {
1318                 error = ovsdb_syntax_error(mr_value, NULL, "column %s "
1319                                            "mentioned more than once",
1320                                            mt->columns[i].column->name);
1321                 goto error;
1322             }
1323         }
1324     }
1325
1326     return ovsdb_jsonrpc_monitor_get_initial(m);
1327
1328 error:
1329     if (m) {
1330         ovsdb_remove_replica(m->db, &m->replica);
1331     }
1332
1333     json = ovsdb_error_to_json(error);
1334     ovsdb_error_destroy(error);
1335     return json;
1336 }
1337
1338 static struct jsonrpc_msg *
1339 ovsdb_jsonrpc_monitor_cancel(struct ovsdb_jsonrpc_session *s,
1340                              struct json_array *params,
1341                              const struct json *request_id)
1342 {
1343     if (params->n != 1) {
1344         return jsonrpc_create_error(json_string_create("invalid parameters"),
1345                                     request_id);
1346     } else {
1347         struct ovsdb_jsonrpc_monitor *m;
1348
1349         m = ovsdb_jsonrpc_monitor_find(s, params->elems[0]);
1350         if (!m) {
1351             return jsonrpc_create_error(json_string_create("unknown monitor"),
1352                                         request_id);
1353         } else {
1354             ovsdb_remove_replica(m->db, &m->replica);
1355             return jsonrpc_create_reply(json_object_create(), request_id);
1356         }
1357     }
1358 }
1359
1360 static void
1361 ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *s)
1362 {
1363     struct ovsdb_jsonrpc_monitor *m, *next;
1364
1365     HMAP_FOR_EACH_SAFE (m, next, node, &s->monitors) {
1366         ovsdb_remove_replica(m->db, &m->replica);
1367     }
1368 }
1369
1370 /* Returns an overestimate of the number of bytes of JSON data required to
1371  * report the current contents of the database over all the monitors currently
1372  * configured in 's'.  */
1373 static size_t
1374 ovsdb_jsonrpc_monitor_json_length_all(struct ovsdb_jsonrpc_session *s)
1375 {
1376     struct ovsdb_jsonrpc_monitor *m;
1377     size_t length;
1378
1379     length = 0;
1380     HMAP_FOR_EACH (m, node, &s->monitors) {
1381         length += ovsdb_jsonrpc_monitor_json_length(m);
1382     }
1383     return length;
1384 }
1385
1386 static struct ovsdb_jsonrpc_monitor *
1387 ovsdb_jsonrpc_monitor_cast(struct ovsdb_replica *replica)
1388 {
1389     ovs_assert(replica->class == &ovsdb_jsonrpc_replica_class);
1390     return CONTAINER_OF(replica, struct ovsdb_jsonrpc_monitor, replica);
1391 }
1392
1393 struct ovsdb_jsonrpc_monitor_aux {
1394     bool initial;               /* Sending initial contents of table? */
1395     const struct ovsdb_jsonrpc_monitor *monitor;
1396     struct json *json;          /* JSON for the whole transaction. */
1397
1398     /* Current table.  */
1399     struct ovsdb_jsonrpc_monitor_table *mt;
1400     struct json *table_json;    /* JSON for table's transaction. */
1401 };
1402
1403 static bool
1404 any_reportable_change(const struct ovsdb_jsonrpc_monitor_table *mt,
1405                       const unsigned long int *changed)
1406 {
1407     size_t i;
1408
1409     for (i = 0; i < mt->n_columns; i++) {
1410         const struct ovsdb_jsonrpc_monitor_column *c = &mt->columns[i];
1411         unsigned int idx = c->column->index;
1412
1413         if (c->select & OJMS_MODIFY && bitmap_is_set(changed, idx)) {
1414             return true;
1415         }
1416     }
1417
1418     return false;
1419 }
1420
1421 static bool
1422 ovsdb_jsonrpc_monitor_change_cb(const struct ovsdb_row *old,
1423                                 const struct ovsdb_row *new,
1424                                 const unsigned long int *changed,
1425                                 void *aux_)
1426 {
1427     struct ovsdb_jsonrpc_monitor_aux *aux = aux_;
1428     const struct ovsdb_jsonrpc_monitor *m = aux->monitor;
1429     struct ovsdb_table *table = new ? new->table : old->table;
1430     enum ovsdb_jsonrpc_monitor_selection type;
1431     struct json *old_json, *new_json;
1432     struct json *row_json;
1433     char uuid[UUID_LEN + 1];
1434     size_t i;
1435
1436     if (!aux->mt || table != aux->mt->table) {
1437         aux->mt = shash_find_data(&m->tables, table->schema->name);
1438         aux->table_json = NULL;
1439         if (!aux->mt) {
1440             /* We don't care about rows in this table at all.  Tell the caller
1441              * to skip it.  */
1442             return false;
1443         }
1444     }
1445
1446     type = (aux->initial ? OJMS_INITIAL
1447             : !old ? OJMS_INSERT
1448             : !new ? OJMS_DELETE
1449             : OJMS_MODIFY);
1450     if (!(aux->mt->select & type)) {
1451         /* We don't care about this type of change (but do want to be called
1452          * back for changes to other rows in the same table). */
1453         return true;
1454     }
1455
1456     if (type == OJMS_MODIFY && !any_reportable_change(aux->mt, changed)) {
1457         /* Nothing of interest changed. */
1458         return true;
1459     }
1460
1461     old_json = new_json = NULL;
1462     if (type & (OJMS_DELETE | OJMS_MODIFY)) {
1463         old_json = json_object_create();
1464     }
1465     if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
1466         new_json = json_object_create();
1467     }
1468     for (i = 0; i < aux->mt->n_columns; i++) {
1469         const struct ovsdb_jsonrpc_monitor_column *c = &aux->mt->columns[i];
1470         const struct ovsdb_column *column = c->column;
1471         unsigned int idx = c->column->index;
1472
1473         if (!(type & c->select)) {
1474             /* We don't care about this type of change for this particular
1475              * column (but we will care about it for some other column). */
1476             continue;
1477         }
1478
1479         if ((type == OJMS_MODIFY && bitmap_is_set(changed, idx))
1480             || type == OJMS_DELETE) {
1481             json_object_put(old_json, column->name,
1482                             ovsdb_datum_to_json(&old->fields[idx],
1483                                                 &column->type));
1484         }
1485         if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
1486             json_object_put(new_json, column->name,
1487                             ovsdb_datum_to_json(&new->fields[idx],
1488                                                 &column->type));
1489         }
1490     }
1491
1492     /* Create JSON object for transaction overall. */
1493     if (!aux->json) {
1494         aux->json = json_object_create();
1495     }
1496
1497     /* Create JSON object for transaction on this table. */
1498     if (!aux->table_json) {
1499         aux->table_json = json_object_create();
1500         json_object_put(aux->json, aux->mt->table->schema->name,
1501                         aux->table_json);
1502     }
1503
1504     /* Create JSON object for transaction on this row. */
1505     row_json = json_object_create();
1506     if (old_json) {
1507         json_object_put(row_json, "old", old_json);
1508     }
1509     if (new_json) {
1510         json_object_put(row_json, "new", new_json);
1511     }
1512
1513     /* Add JSON row to JSON table. */
1514     snprintf(uuid, sizeof uuid,
1515              UUID_FMT, UUID_ARGS(ovsdb_row_get_uuid(new ? new : old)));
1516     json_object_put(aux->table_json, uuid, row_json);
1517
1518     return true;
1519 }
1520
1521 /* Returns an overestimate of the number of bytes of JSON data required to
1522  * report the current contents of the database over monitor 'm'. */
1523 static size_t
1524 ovsdb_jsonrpc_monitor_json_length(const struct ovsdb_jsonrpc_monitor *m)
1525 {
1526     const struct shash_node *node;
1527     size_t length;
1528
1529     /* Top-level overhead of monitor JSON. */
1530     length = 256;
1531
1532     SHASH_FOR_EACH (node, &m->tables) {
1533         const struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1534         const struct ovsdb_table *table = mt->table;
1535         const struct ovsdb_row *row;
1536         size_t i;
1537
1538         /* Per-table JSON overhead: "<table>":{...}. */
1539         length += strlen(table->schema->name) + 32;
1540
1541         /* Per-row JSON overhead: ,"<uuid>":{"old":{...},"new":{...}} */
1542         length += hmap_count(&table->rows) * (UUID_LEN + 32);
1543
1544         /* Per-row, per-column JSON overhead: ,"<column>": */
1545         for (i = 0; i < mt->n_columns; i++) {
1546             const struct ovsdb_jsonrpc_monitor_column *c = &mt->columns[i];
1547             const struct ovsdb_column *column = c->column;
1548
1549             length += hmap_count(&table->rows) * (8 + strlen(column->name));
1550         }
1551
1552         /* Data. */
1553         HMAP_FOR_EACH (row, hmap_node, &table->rows) {
1554             for (i = 0; i < mt->n_columns; i++) {
1555                 const struct ovsdb_jsonrpc_monitor_column *c = &mt->columns[i];
1556                 const struct ovsdb_column *column = c->column;
1557
1558                 length += ovsdb_datum_json_length(&row->fields[column->index],
1559                                                   &column->type);
1560             }
1561         }
1562     }
1563
1564     return length;
1565 }
1566
1567 static void
1568 ovsdb_jsonrpc_monitor_init_aux(struct ovsdb_jsonrpc_monitor_aux *aux,
1569                                const struct ovsdb_jsonrpc_monitor *m,
1570                                bool initial)
1571 {
1572     aux->initial = initial;
1573     aux->monitor = m;
1574     aux->json = NULL;
1575     aux->mt = NULL;
1576     aux->table_json = NULL;
1577 }
1578
1579 static struct ovsdb_error *
1580 ovsdb_jsonrpc_monitor_commit(struct ovsdb_replica *replica,
1581                              const struct ovsdb_txn *txn,
1582                              bool durable OVS_UNUSED)
1583 {
1584     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1585     struct ovsdb_jsonrpc_monitor_aux aux;
1586
1587     ovsdb_jsonrpc_monitor_init_aux(&aux, m, false);
1588     ovsdb_txn_for_each_change(txn, ovsdb_jsonrpc_monitor_change_cb, &aux);
1589     if (aux.json) {
1590         struct jsonrpc_msg *msg;
1591         struct json *params;
1592
1593         params = json_array_create_2(json_clone(aux.monitor->monitor_id),
1594                                      aux.json);
1595         msg = jsonrpc_create_notify("update", params);
1596         jsonrpc_session_send(aux.monitor->session->js, msg);
1597     }
1598
1599     return NULL;
1600 }
1601
1602 static struct json *
1603 ovsdb_jsonrpc_monitor_get_initial(const struct ovsdb_jsonrpc_monitor *m)
1604 {
1605     struct ovsdb_jsonrpc_monitor_aux aux;
1606     struct shash_node *node;
1607
1608     ovsdb_jsonrpc_monitor_init_aux(&aux, m, true);
1609     SHASH_FOR_EACH (node, &m->tables) {
1610         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1611
1612         if (mt->select & OJMS_INITIAL) {
1613             struct ovsdb_row *row;
1614
1615             HMAP_FOR_EACH (row, hmap_node, &mt->table->rows) {
1616                 ovsdb_jsonrpc_monitor_change_cb(NULL, row, NULL, &aux);
1617             }
1618         }
1619     }
1620     return aux.json ? aux.json : json_object_create();
1621 }
1622
1623 static void
1624 ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *replica)
1625 {
1626     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1627     struct shash_node *node;
1628
1629     json_destroy(m->monitor_id);
1630     SHASH_FOR_EACH (node, &m->tables) {
1631         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1632         free(mt->columns);
1633         free(mt);
1634     }
1635     shash_destroy(&m->tables);
1636     hmap_remove(&m->session->monitors, &m->node);
1637     free(m);
1638 }
1639
1640 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class = {
1641     ovsdb_jsonrpc_monitor_commit,
1642     ovsdb_jsonrpc_monitor_destroy
1643 };