ovsdb/jsonrpc-server.c

   1 /* Copyright (c) 2009, 2010 Nicira Networks
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include <config.h>
  17
  18 #include "jsonrpc-server.h"
  19
  20 #include <assert.h>
  21 #include <errno.h>
  22
  23 #include "column.h"
  24 #include "json.h"
  25 #include "jsonrpc.h"
  26 #include "ovsdb-error.h"
  27 #include "ovsdb-parser.h"
  28 #include "ovsdb.h"
  29 #include "reconnect.h"
  30 #include "row.h"
  31 #include "stream.h"
  32 #include "table.h"
  33 #include "timeval.h"
  34 #include "transaction.h"
  35 #include "trigger.h"
  36
  37 #define THIS_MODULE VLM_ovsdb_jsonrpc_server
  38 #include "vlog.h"
  39
  40 struct ovsdb_jsonrpc_remote;
  41 struct ovsdb_jsonrpc_session;
  42
  43 /* Message rate-limiting. */
  44 struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
  45
  46 /* Sessions. */
  47 static struct ovsdb_jsonrpc_session *ovsdb_jsonrpc_session_create(
  48     struct ovsdb_jsonrpc_remote *, struct jsonrpc_session *);
  49 static void ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *);
  50 static void ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *);
  51 static void ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *);
  52
  53 /* Triggers. */
  54 static void ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *,
  55                                          struct json *id, struct json *params);
  56 static struct ovsdb_jsonrpc_trigger *ovsdb_jsonrpc_trigger_find(
  57     struct ovsdb_jsonrpc_session *, const struct json *id, size_t hash);
  58 static void ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *);
  59 static void ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *);
  60 static void ovsdb_jsonrpc_trigger_complete_done(
  61     struct ovsdb_jsonrpc_session *);
  62
  63 /* Monitors. */
  64 static struct json *ovsdb_jsonrpc_monitor_create(
  65     struct ovsdb_jsonrpc_session *, struct json *params);
  66 static struct jsonrpc_msg *ovsdb_jsonrpc_monitor_cancel(
  67     struct ovsdb_jsonrpc_session *,
  68     struct json_array *params,
  69     const struct json *request_id);
  70 static void ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *);
  71 \f
  72 /* JSON-RPC database server. */
  73
  74 struct ovsdb_jsonrpc_server {
  75     struct ovsdb *db;
  76     unsigned int n_sessions, max_sessions;
  77     struct shash remotes;      /* Contains "struct ovsdb_jsonrpc_remote *"s. */
  78 };
  79
  80 /* A configured remote.  This is either a passive stream listener plus a list
  81  * of the currently connected sessions, or a list of exactly one active
  82  * session. */
  83 struct ovsdb_jsonrpc_remote {
  84     struct ovsdb_jsonrpc_server *server;
  85     struct pstream *listener;   /* Listener, if passive. */
  86     struct list sessions;       /* List of "struct ovsdb_jsonrpc_session"s. */
  87 };
  88
  89 static void ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *,
  90                                             const char *name);
  91 static void ovsdb_jsonrpc_server_del_remote(struct shash_node *);
  92
  93 struct ovsdb_jsonrpc_server *
  94 ovsdb_jsonrpc_server_create(struct ovsdb *db)
  95 {
  96     struct ovsdb_jsonrpc_server *server = xzalloc(sizeof *server);
  97     server->db = db;
  98     server->max_sessions = 64;
  99     shash_init(&server->remotes);
 100     return server;
 101 }
 102
 103 void
 104 ovsdb_jsonrpc_server_destroy(struct ovsdb_jsonrpc_server *svr)
 105 {
 106     struct shash_node *node, *next;
 107
 108     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
 109         ovsdb_jsonrpc_server_del_remote(node);
 110     }
 111     shash_destroy(&svr->remotes);
 112     free(svr);
 113 }
 114
 115 /* Sets 'svr''s current set of remotes to the names in 'new_remotes'.  The data
 116  * values in 'new_remotes' are ignored.
 117  *
 118  * A remote is an active or passive stream connection method, e.g. "pssl:" or
 119  * "tcp:1.2.3.4". */
 120 void
 121 ovsdb_jsonrpc_server_set_remotes(struct ovsdb_jsonrpc_server *svr,
 122                                  const struct shash *new_remotes)
 123 {
 124     struct shash_node *node, *next;
 125
 126     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
 127         if (!shash_find(new_remotes, node->name)) {
 128             ovsdb_jsonrpc_server_del_remote(node);
 129         }
 130     }
 131     SHASH_FOR_EACH (node, new_remotes) {
 132         if (!shash_find(&svr->remotes, node->name)) {
 133             ovsdb_jsonrpc_server_add_remote(svr, node->name);
 134         }
 135     }
 136 }
 137
 138 static void
 139 ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *svr,
 140                                 const char *name)
 141 {
 142     struct ovsdb_jsonrpc_remote *remote;
 143     struct pstream *listener;
 144     int error;
 145
 146     error = pstream_open(name, &listener);
 147     if (error && error != EAFNOSUPPORT) {
 148         VLOG_ERR_RL(&rl, "%s: listen failed: %s", name, strerror(error));
 149         return;
 150     }
 151
 152     remote = xmalloc(sizeof *remote);
 153     remote->server = svr;
 154     remote->listener = listener;
 155     list_init(&remote->sessions);
 156     shash_add(&svr->remotes, name, remote);
 157
 158     if (!listener) {
 159         ovsdb_jsonrpc_session_create(remote, jsonrpc_session_open(name));
 160     }
 161 }
 162
 163 static void
 164 ovsdb_jsonrpc_server_del_remote(struct shash_node *node)
 165 {
 166     struct ovsdb_jsonrpc_remote *remote = node->data;
 167
 168     ovsdb_jsonrpc_session_close_all(remote);
 169     pstream_close(remote->listener);
 170     shash_delete(&remote->server->remotes, node);
 171     free(remote);
 172 }
 173
 174 void
 175 ovsdb_jsonrpc_server_run(struct ovsdb_jsonrpc_server *svr)
 176 {
 177     struct shash_node *node;
 178
 179     SHASH_FOR_EACH (node, &svr->remotes) {
 180         struct ovsdb_jsonrpc_remote *remote = node->data;
 181
 182         if (remote->listener && svr->n_sessions < svr->max_sessions) {
 183             struct stream *stream;
 184             int error;
 185
 186             error = pstream_accept(remote->listener, &stream);
 187             if (!error) {
 188                 struct jsonrpc_session *js;
 189                 js = jsonrpc_session_open_unreliably(jsonrpc_open(stream));
 190                 ovsdb_jsonrpc_session_create(remote, js);
 191             } else if (error != EAGAIN) {
 192                 VLOG_WARN_RL(&rl, "%s: accept failed: %s",
 193                              pstream_get_name(remote->listener),
 194                              strerror(error));
 195             }
 196         }
 197
 198         ovsdb_jsonrpc_session_run_all(remote);
 199     }
 200 }
 201
 202 void
 203 ovsdb_jsonrpc_server_wait(struct ovsdb_jsonrpc_server *svr)
 204 {
 205     struct shash_node *node;
 206
 207     SHASH_FOR_EACH (node, &svr->remotes) {
 208         struct ovsdb_jsonrpc_remote *remote = node->data;
 209
 210         if (remote->listener && svr->n_sessions < svr->max_sessions) {
 211             pstream_wait(remote->listener);
 212         }
 213
 214         ovsdb_jsonrpc_session_wait_all(remote);
 215     }
 216 }
 217 \f
 218 /* JSON-RPC database server session. */
 219
 220 struct ovsdb_jsonrpc_session {
 221     struct ovsdb_jsonrpc_remote *remote;
 222     struct list node;           /* Element in remote's sessions list. */
 223
 224     /* Triggers. */
 225     struct hmap triggers;       /* Hmap of "struct ovsdb_jsonrpc_trigger"s. */
 226     struct list completions;    /* Completed triggers. */
 227
 228     /* Monitors. */
 229     struct hmap monitors;       /* Hmap of "struct ovsdb_jsonrpc_monitor"s. */
 230
 231     /* Network connectivity. */
 232     struct jsonrpc_session *js;  /* JSON-RPC session. */
 233     unsigned int js_seqno;       /* Last jsonrpc_session_get_seqno() value. */
 234 };
 235
 236 static void ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *);
 237 static int ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *);
 238 static void ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *);
 239 static void ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *,
 240                                              struct jsonrpc_msg *);
 241 static void ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *,
 242                                              struct jsonrpc_msg *);
 243
 244 static struct ovsdb_jsonrpc_session *
 245 ovsdb_jsonrpc_session_create(struct ovsdb_jsonrpc_remote *remote,
 246                              struct jsonrpc_session *js)
 247 {
 248     struct ovsdb_jsonrpc_session *s;
 249
 250     s = xzalloc(sizeof *s);
 251     s->remote = remote;
 252     list_push_back(&remote->sessions, &s->node);
 253     hmap_init(&s->triggers);
 254     hmap_init(&s->monitors);
 255     list_init(&s->completions);
 256     s->js = js;
 257     s->js_seqno = jsonrpc_session_get_seqno(js);
 258
 259     remote->server->n_sessions++;
 260
 261     return s;
 262 }
 263
 264 static void
 265 ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *s)
 266 {
 267     ovsdb_jsonrpc_monitor_remove_all(s);
 268     jsonrpc_session_close(s->js);
 269     list_remove(&s->node);
 270     s->remote->server->n_sessions--;
 271     free(s);
 272 }
 273
 274 static int
 275 ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *s)
 276 {
 277     jsonrpc_session_run(s->js);
 278     if (s->js_seqno != jsonrpc_session_get_seqno(s->js)) {
 279         s->js_seqno = jsonrpc_session_get_seqno(s->js);
 280         ovsdb_jsonrpc_trigger_complete_all(s);
 281         ovsdb_jsonrpc_monitor_remove_all(s);
 282     }
 283
 284     ovsdb_jsonrpc_trigger_complete_done(s);
 285
 286     if (!jsonrpc_session_get_backlog(s->js)) {
 287         struct jsonrpc_msg *msg = jsonrpc_session_recv(s->js);
 288         if (msg) {
 289             if (msg->type == JSONRPC_REQUEST) {
 290                 ovsdb_jsonrpc_session_got_request(s, msg);
 291             } else if (msg->type == JSONRPC_NOTIFY) {
 292                 ovsdb_jsonrpc_session_got_notify(s, msg);
 293             } else {
 294                 VLOG_WARN("%s: received unexpected %s message",
 295                           jsonrpc_session_get_name(s->js),
 296                           jsonrpc_msg_type_to_string(msg->type));
 297                 jsonrpc_session_force_reconnect(s->js);
 298                 jsonrpc_msg_destroy(msg);
 299             }
 300         }
 301     }
 302     return jsonrpc_session_is_alive(s->js) ? 0 : ETIMEDOUT;
 303 }
 304
 305 static void
 306 ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *remote)
 307 {
 308     struct ovsdb_jsonrpc_session *s, *next;
 309
 310     LIST_FOR_EACH_SAFE (s, next, struct ovsdb_jsonrpc_session, node,
 311                         &remote->sessions) {
 312         int error = ovsdb_jsonrpc_session_run(s);
 313         if (error) {
 314             ovsdb_jsonrpc_session_close(s);
 315         }
 316     }
 317 }
 318
 319 static void
 320 ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *s)
 321 {
 322     jsonrpc_session_wait(s->js);
 323     if (!jsonrpc_session_get_backlog(s->js)) {
 324         jsonrpc_session_recv_wait(s->js);
 325     }
 326 }
 327
 328 static void
 329 ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *remote)
 330 {
 331     struct ovsdb_jsonrpc_session *s;
 332
 333     LIST_FOR_EACH (s, struct ovsdb_jsonrpc_session, node, &remote->sessions) {
 334         ovsdb_jsonrpc_session_wait(s);
 335     }
 336 }
 337
 338 static void
 339 ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *remote)
 340 {
 341     struct ovsdb_jsonrpc_session *s, *next;
 342
 343     LIST_FOR_EACH_SAFE (s, next, struct ovsdb_jsonrpc_session, node,
 344                         &remote->sessions) {
 345         ovsdb_jsonrpc_session_close(s);
 346     }
 347 }
 348
 349 static const char *
 350 get_db_name(const struct ovsdb_jsonrpc_session *s)
 351 {
 352     return s->remote->server->db->schema->name;
 353 }
 354
 355 static struct jsonrpc_msg *
 356 ovsdb_jsonrpc_check_db_name(const struct ovsdb_jsonrpc_session *s,
 357                             const struct jsonrpc_msg *request)
 358 {
 359     struct json_array *params;
 360     const char *want_db_name;
 361     const char *have_db_name;
 362     struct ovsdb_error *error;
 363     struct jsonrpc_msg *reply;
 364
 365     params = json_array(request->params);
 366     if (!params->n || params->elems[0]->type != JSON_STRING) {
 367         error = ovsdb_syntax_error(
 368             request->params, NULL,
 369             "%s request params must begin with <db-name>", request->method);
 370         goto error;
 371     }
 372
 373     want_db_name = params->elems[0]->u.string;
 374     have_db_name = get_db_name(s);
 375     if (strcmp(want_db_name, have_db_name)) {
 376         error = ovsdb_syntax_error(
 377             request->params, "unknown database",
 378             "%s request specifies unknown database %s",
 379             request->method, want_db_name);
 380         goto error;
 381     }
 382
 383     return NULL;
 384
 385 error:
 386     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
 387     ovsdb_error_destroy(error);
 388     return reply;
 389 }
 390
 391 static struct jsonrpc_msg *
 392 execute_transaction(struct ovsdb_jsonrpc_session *s,
 393                     struct jsonrpc_msg *request)
 394 {
 395     ovsdb_jsonrpc_trigger_create(s, request->id, request->params);
 396     request->id = NULL;
 397     request->params = NULL;
 398     jsonrpc_msg_destroy(request);
 399     return NULL;
 400 }
 401
 402 static void
 403 ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *s,
 404                                   struct jsonrpc_msg *request)
 405 {
 406     struct jsonrpc_msg *reply;
 407
 408     if (!strcmp(request->method, "transact")) {
 409         reply = ovsdb_jsonrpc_check_db_name(s, request);
 410         if (!reply) {
 411             reply = execute_transaction(s, request);
 412         }
 413     } else if (!strcmp(request->method, "monitor")) {
 414         reply = ovsdb_jsonrpc_check_db_name(s, request);
 415         if (!reply) {
 416             reply = jsonrpc_create_reply(
 417                 ovsdb_jsonrpc_monitor_create(s, request->params), request->id);
 418         }
 419     } else if (!strcmp(request->method, "monitor_cancel")) {
 420         reply = ovsdb_jsonrpc_monitor_cancel(s, json_array(request->params),
 421                                              request->id);
 422     } else if (!strcmp(request->method, "get_schema")) {
 423         reply = ovsdb_jsonrpc_check_db_name(s, request);
 424         if (!reply) {
 425             reply = jsonrpc_create_reply(
 426                 ovsdb_schema_to_json(s->remote->server->db->schema),
 427                 request->id);
 428         }
 429     } else if (!strcmp(request->method, "list_dbs")) {
 430         reply = jsonrpc_create_reply(
 431             json_array_create_1(json_string_create(get_db_name(s))),
 432             request->id);
 433     } else if (!strcmp(request->method, "echo")) {
 434         reply = jsonrpc_create_reply(json_clone(request->params), request->id);
 435     } else {
 436         reply = jsonrpc_create_error(json_string_create("unknown method"),
 437                                      request->id);
 438     }
 439
 440     if (reply) {
 441         jsonrpc_msg_destroy(request);
 442         jsonrpc_session_send(s->js, reply);
 443     }
 444 }
 445
 446 static void
 447 execute_cancel(struct ovsdb_jsonrpc_session *s, struct jsonrpc_msg *request)
 448 {
 449     if (json_array(request->params)->n == 1) {
 450         struct ovsdb_jsonrpc_trigger *t;
 451         struct json *id;
 452
 453         id = request->params->u.array.elems[0];
 454         t = ovsdb_jsonrpc_trigger_find(s, id, json_hash(id, 0));
 455         if (t) {
 456             ovsdb_jsonrpc_trigger_complete(t);
 457         }
 458     }
 459 }
 460
 461 static void
 462 ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *s,
 463                                  struct jsonrpc_msg *request)
 464 {
 465     if (!strcmp(request->method, "cancel")) {
 466         execute_cancel(s, request);
 467     }
 468     jsonrpc_msg_destroy(request);
 469 }
 470 \f
 471 /* JSON-RPC database server triggers.
 472  *
 473  * (Every transaction is treated as a trigger even if it doesn't actually have
 474  * any "wait" operations.) */
 475
 476 struct ovsdb_jsonrpc_trigger {
 477     struct ovsdb_trigger trigger;
 478     struct ovsdb_jsonrpc_session *session;
 479     struct hmap_node hmap_node; /* In session's "triggers" hmap. */
 480     struct json *id;
 481 };
 482
 483 static void
 484 ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *s,
 485                              struct json *id, struct json *params)
 486 {
 487     struct ovsdb_jsonrpc_trigger *t;
 488     size_t hash;
 489
 490     /* Check for duplicate ID. */
 491     hash = json_hash(id, 0);
 492     t = ovsdb_jsonrpc_trigger_find(s, id, hash);
 493     if (t) {
 494         struct jsonrpc_msg *msg;
 495
 496         msg = jsonrpc_create_error(json_string_create("duplicate request ID"),
 497                                    id);
 498         jsonrpc_session_send(s->js, msg);
 499         json_destroy(id);
 500         json_destroy(params);
 501         return;
 502     }
 503
 504     /* Insert into trigger table. */
 505     t = xmalloc(sizeof *t);
 506     ovsdb_trigger_init(s->remote->server->db,
 507                        &t->trigger, params, &s->completions,
 508                        time_msec());
 509     t->session = s;
 510     t->id = id;
 511     hmap_insert(&s->triggers, &t->hmap_node, hash);
 512
 513     /* Complete early if possible. */
 514     if (ovsdb_trigger_is_complete(&t->trigger)) {
 515         ovsdb_jsonrpc_trigger_complete(t);
 516     }
 517 }
 518
 519 static struct ovsdb_jsonrpc_trigger *
 520 ovsdb_jsonrpc_trigger_find(struct ovsdb_jsonrpc_session *s,
 521                            const struct json *id, size_t hash)
 522 {
 523     struct ovsdb_jsonrpc_trigger *t;
 524
 525     HMAP_FOR_EACH_WITH_HASH (t, struct ovsdb_jsonrpc_trigger, hmap_node, hash,
 526                              &s->triggers) {
 527         if (json_equal(t->id, id)) {
 528             return t;
 529         }
 530     }
 531
 532     return NULL;
 533 }
 534
 535 static void
 536 ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *t)
 537 {
 538     struct ovsdb_jsonrpc_session *s = t->session;
 539
 540     if (jsonrpc_session_is_connected(s->js)) {
 541         struct jsonrpc_msg *reply;
 542         struct json *result;
 543
 544         result = ovsdb_trigger_steal_result(&t->trigger);
 545         if (result) {
 546             reply = jsonrpc_create_reply(result, t->id);
 547         } else {
 548             reply = jsonrpc_create_error(json_string_create("canceled"),
 549                                          t->id);
 550         }
 551         jsonrpc_session_send(s->js, reply);
 552     }
 553
 554     json_destroy(t->id);
 555     ovsdb_trigger_destroy(&t->trigger);
 556     hmap_remove(&s->triggers, &t->hmap_node);
 557     free(t);
 558 }
 559
 560 static void
 561 ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *s)
 562 {
 563     struct ovsdb_jsonrpc_trigger *t, *next;
 564     HMAP_FOR_EACH_SAFE (t, next, struct ovsdb_jsonrpc_trigger, hmap_node,
 565                         &s->triggers) {
 566         ovsdb_jsonrpc_trigger_complete(t);
 567     }
 568 }
 569
 570 static void
 571 ovsdb_jsonrpc_trigger_complete_done(struct ovsdb_jsonrpc_session *s)
 572 {
 573     while (!list_is_empty(&s->completions)) {
 574         struct ovsdb_jsonrpc_trigger *t
 575             = CONTAINER_OF(s->completions.next,
 576                            struct ovsdb_jsonrpc_trigger, trigger.node);
 577         ovsdb_jsonrpc_trigger_complete(t);
 578     }
 579 }
 580 \f
 581 /* JSON-RPC database table monitors. */
 582
 583 enum ovsdb_jsonrpc_monitor_selection {
 584     OJMS_INITIAL = 1 << 0,      /* All rows when monitor is created. */
 585     OJMS_INSERT = 1 << 1,       /* New rows. */
 586     OJMS_DELETE = 1 << 2,       /* Deleted rows. */
 587     OJMS_MODIFY = 1 << 3        /* Modified rows. */
 588 };
 589
 590 struct ovsdb_jsonrpc_monitor_table {
 591     const struct ovsdb_table *table;
 592     enum ovsdb_jsonrpc_monitor_selection select;
 593     struct ovsdb_column_set columns;
 594 };
 595
 596 struct ovsdb_jsonrpc_monitor {
 597     struct ovsdb_replica replica;
 598     struct ovsdb_jsonrpc_session *session;
 599     struct hmap_node node;      /* In ovsdb_jsonrpc_session's "monitors". */
 600
 601     struct json *monitor_id;
 602     struct shash tables;     /* Holds "struct ovsdb_jsonrpc_monitor_table"s. */
 603 };
 604
 605 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class;
 606
 607 struct ovsdb_jsonrpc_monitor *ovsdb_jsonrpc_monitor_find(
 608     struct ovsdb_jsonrpc_session *, const struct json *monitor_id);
 609 static void ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *);
 610 static struct json *ovsdb_jsonrpc_monitor_get_initial(
 611     const struct ovsdb_jsonrpc_monitor *);
 612
 613 static bool
 614 parse_bool(struct ovsdb_parser *parser, const char *name, bool default_value)
 615 {
 616     const struct json *json;
 617
 618     json = ovsdb_parser_member(parser, name, OP_BOOLEAN | OP_OPTIONAL);
 619     return json ? json_boolean(json) : default_value;
 620 }
 621
 622 struct ovsdb_jsonrpc_monitor *
 623 ovsdb_jsonrpc_monitor_find(struct ovsdb_jsonrpc_session *s,
 624                            const struct json *monitor_id)
 625 {
 626     struct ovsdb_jsonrpc_monitor *m;
 627
 628     HMAP_FOR_EACH_WITH_HASH (m, struct ovsdb_jsonrpc_monitor, node,
 629                              json_hash(monitor_id, 0), &s->monitors) {
 630         if (json_equal(m->monitor_id, monitor_id)) {
 631             return m;
 632         }
 633     }
 634
 635     return NULL;
 636 }
 637
 638 static struct json *
 639 ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s,
 640                              struct json *params)
 641 {
 642     struct ovsdb_jsonrpc_monitor *m = NULL;
 643     struct json *monitor_id, *monitor_requests;
 644     struct ovsdb_error *error = NULL;
 645     struct shash_node *node;
 646     struct json *json;
 647
 648     if (json_array(params)->n != 3) {
 649         error = ovsdb_syntax_error(params, NULL, "invalid parameters");
 650         goto error;
 651     }
 652     monitor_id = params->u.array.elems[1];
 653     monitor_requests = params->u.array.elems[2];
 654     if (monitor_requests->type != JSON_OBJECT) {
 655         error = ovsdb_syntax_error(monitor_requests, NULL,
 656                                    "monitor-requests must be object");
 657         goto error;
 658     }
 659
 660     if (ovsdb_jsonrpc_monitor_find(s, monitor_id)) {
 661         error = ovsdb_syntax_error(monitor_id, NULL, "duplicate monitor ID");
 662         goto error;
 663     }
 664
 665     m = xzalloc(sizeof *m);
 666     ovsdb_replica_init(&m->replica, &ovsdb_jsonrpc_replica_class);
 667     ovsdb_add_replica(s->remote->server->db, &m->replica);
 668     m->session = s;
 669     hmap_insert(&s->monitors, &m->node, json_hash(monitor_id, 0));
 670     m->monitor_id = json_clone(monitor_id);
 671     shash_init(&m->tables);
 672
 673     SHASH_FOR_EACH (node, json_object(monitor_requests)) {
 674         const struct ovsdb_table *table;
 675         struct ovsdb_jsonrpc_monitor_table *mt;
 676         const struct json *columns_json, *select_json;
 677         struct ovsdb_parser parser;
 678
 679         table = ovsdb_get_table(s->remote->server->db, node->name);
 680         if (!table) {
 681             error = ovsdb_syntax_error(NULL, NULL,
 682                                        "no table named %s", node->name);
 683             goto error;
 684         }
 685
 686         mt = xzalloc(sizeof *mt);
 687         mt->table = table;
 688         mt->select = OJMS_INITIAL | OJMS_INSERT | OJMS_DELETE | OJMS_MODIFY;
 689         ovsdb_column_set_init(&mt->columns);
 690         shash_add(&m->tables, table->schema->name, mt);
 691
 692         ovsdb_parser_init(&parser, node->data, "table %s", node->name);
 693         columns_json = ovsdb_parser_member(&parser, "columns",
 694                                            OP_ARRAY | OP_OPTIONAL);
 695         select_json = ovsdb_parser_member(&parser, "select",
 696                                           OP_OBJECT | OP_OPTIONAL);
 697         error = ovsdb_parser_finish(&parser);
 698         if (error) {
 699             goto error;
 700         }
 701
 702         if (columns_json) {
 703             error = ovsdb_column_set_from_json(columns_json, table,
 704                                                &mt->columns);
 705             if (error) {
 706                 goto error;
 707             }
 708         } else {
 709             struct shash_node *node;
 710
 711             SHASH_FOR_EACH (node, &table->schema->columns) {
 712                 const struct ovsdb_column *column = node->data;
 713                 if (column->index != OVSDB_COL_UUID) {
 714                     ovsdb_column_set_add(&mt->columns, column);
 715                 }
 716             }
 717         }
 718
 719         if (select_json) {
 720             mt->select = 0;
 721             ovsdb_parser_init(&parser, select_json, "table %s select",
 722                               table->schema->name);
 723             if (parse_bool(&parser, "initial", true)) {
 724                 mt->select |= OJMS_INITIAL;
 725             }
 726             if (parse_bool(&parser, "insert", true)) {
 727                 mt->select |= OJMS_INSERT;
 728             }
 729             if (parse_bool(&parser, "delete", true)) {
 730                 mt->select |= OJMS_DELETE;
 731             }
 732             if (parse_bool(&parser, "modify", true)) {
 733                 mt->select |= OJMS_MODIFY;
 734             }
 735             error = ovsdb_parser_finish(&parser);
 736             if (error) {
 737                 goto error;
 738             }
 739         }
 740     }
 741
 742     return ovsdb_jsonrpc_monitor_get_initial(m);
 743
 744 error:
 745     if (m) {
 746         ovsdb_remove_replica(s->remote->server->db, &m->replica);
 747     }
 748
 749     json = ovsdb_error_to_json(error);
 750     ovsdb_error_destroy(error);
 751     return json;
 752 }
 753
 754 static struct jsonrpc_msg *
 755 ovsdb_jsonrpc_monitor_cancel(struct ovsdb_jsonrpc_session *s,
 756                              struct json_array *params,
 757                              const struct json *request_id)
 758 {
 759     if (params->n != 1) {
 760         return jsonrpc_create_error(json_string_create("invalid parameters"),
 761                                     request_id);
 762     } else {
 763         struct ovsdb_jsonrpc_monitor *m;
 764
 765         m = ovsdb_jsonrpc_monitor_find(s, params->elems[0]);
 766         if (!m) {
 767             return jsonrpc_create_error(json_string_create("unknown monitor"),
 768                                         request_id);
 769         } else {
 770             ovsdb_remove_replica(s->remote->server->db, &m->replica);
 771             return jsonrpc_create_reply(json_object_create(), request_id);
 772         }
 773     }
 774 }
 775
 776 static void
 777 ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *s)
 778 {
 779     struct ovsdb_jsonrpc_monitor *m, *next;
 780
 781     HMAP_FOR_EACH_SAFE (m, next,
 782                         struct ovsdb_jsonrpc_monitor, node, &s->monitors) {
 783         ovsdb_remove_replica(s->remote->server->db, &m->replica);
 784     }
 785 }
 786
 787 static struct ovsdb_jsonrpc_monitor *
 788 ovsdb_jsonrpc_monitor_cast(struct ovsdb_replica *replica)
 789 {
 790     assert(replica->class == &ovsdb_jsonrpc_replica_class);
 791     return CONTAINER_OF(replica, struct ovsdb_jsonrpc_monitor, replica);
 792 }
 793
 794 struct ovsdb_jsonrpc_monitor_aux {
 795     bool initial;               /* Sending initial contents of table? */
 796     const struct ovsdb_jsonrpc_monitor *monitor;
 797     struct json *json;          /* JSON for the whole transaction. */
 798
 799     /* Current table.  */
 800     struct ovsdb_jsonrpc_monitor_table *mt;
 801     struct json *table_json;    /* JSON for table's transaction. */
 802 };
 803
 804 static bool
 805 ovsdb_jsonrpc_monitor_change_cb(const struct ovsdb_row *old,
 806                                 const struct ovsdb_row *new,
 807                                 void *aux_)
 808 {
 809     struct ovsdb_jsonrpc_monitor_aux *aux = aux_;
 810     const struct ovsdb_jsonrpc_monitor *m = aux->monitor;
 811     struct ovsdb_table *table = new ? new->table : old->table;
 812     enum ovsdb_jsonrpc_monitor_selection type;
 813     struct json *old_json, *new_json;
 814     struct json *row_json;
 815     char uuid[UUID_LEN + 1];
 816     int n_changed;
 817     size_t i;
 818
 819     if (!aux->mt || table != aux->mt->table) {
 820         aux->mt = shash_find_data(&m->tables, table->schema->name);
 821         aux->table_json = NULL;
 822         if (!aux->mt) {
 823             /* We don't care about rows in this table at all.  Tell the caller
 824              * to skip it.  */
 825             return false;
 826         }
 827     }
 828
 829     type = (aux->initial ? OJMS_INITIAL
 830             : !old ? OJMS_INSERT
 831             : !new ? OJMS_DELETE
 832             : OJMS_MODIFY);
 833     if (!(aux->mt->select & type)) {
 834         /* We don't care about this type of change (but do want to be called
 835          * back for changes to other rows in the same table). */
 836         return true;
 837     }
 838
 839     old_json = new_json = NULL;
 840     n_changed = 0;
 841     for (i = 0; i < aux->mt->columns.n_columns; i++) {
 842         const struct ovsdb_column *column = aux->mt->columns.columns[i];
 843         unsigned int idx = column->index;
 844         bool changed = false;
 845
 846         if (type == OJMS_MODIFY) {
 847             changed = !ovsdb_datum_equals(&old->fields[idx],
 848                                           &new->fields[idx], &column->type);
 849             n_changed += changed;
 850         }
 851         if (changed || type == OJMS_DELETE) {
 852             if (!old_json) {
 853                 old_json = json_object_create();
 854             }
 855             json_object_put(old_json, column->name,
 856                             ovsdb_datum_to_json(&old->fields[idx],
 857                                                 &column->type));
 858         }
 859         if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
 860             if (!new_json) {
 861                 new_json = json_object_create();
 862             }
 863             json_object_put(new_json, column->name,
 864                             ovsdb_datum_to_json(&new->fields[idx],
 865                                                 &column->type));
 866         }
 867     }
 868     if ((type == OJMS_MODIFY && !n_changed) || (!old_json && !new_json)) {
 869         /* No reportable changes. */
 870         json_destroy(old_json);
 871         json_destroy(new_json);
 872         return true;
 873     }
 874
 875     /* Create JSON object for transaction overall. */
 876     if (!aux->json) {
 877         aux->json = json_object_create();
 878     }
 879
 880     /* Create JSON object for transaction on this table. */
 881     if (!aux->table_json) {
 882         aux->table_json = json_object_create();
 883         json_object_put(aux->json, aux->mt->table->schema->name,
 884                         aux->table_json);
 885     }
 886
 887     /* Create JSON object for transaction on this row. */
 888     row_json = json_object_create();
 889     if (old_json) {
 890         json_object_put(row_json, "old", old_json);
 891     }
 892     if (new_json) {
 893         json_object_put(row_json, "new", new_json);
 894     }
 895
 896     /* Add JSON row to JSON table. */
 897     snprintf(uuid, sizeof uuid,
 898              UUID_FMT, UUID_ARGS(ovsdb_row_get_uuid(new ? new : old)));
 899     json_object_put(aux->table_json, uuid, row_json);
 900
 901     return true;
 902 }
 903
 904 static void
 905 ovsdb_jsonrpc_monitor_init_aux(struct ovsdb_jsonrpc_monitor_aux *aux,
 906                                const struct ovsdb_jsonrpc_monitor *m,
 907                                bool initial)
 908 {
 909     aux->initial = initial;
 910     aux->monitor = m;
 911     aux->json = NULL;
 912     aux->mt = NULL;
 913     aux->table_json = NULL;
 914 }
 915
 916 static struct ovsdb_error *
 917 ovsdb_jsonrpc_monitor_commit(struct ovsdb_replica *replica,
 918                              const struct ovsdb_txn *txn, bool durable UNUSED)
 919 {
 920     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
 921     struct ovsdb_jsonrpc_monitor_aux aux;
 922
 923     ovsdb_jsonrpc_monitor_init_aux(&aux, m, false);
 924     ovsdb_txn_for_each_change(txn, ovsdb_jsonrpc_monitor_change_cb, &aux);
 925     if (aux.json) {
 926         struct jsonrpc_msg *msg;
 927         struct json *params;
 928
 929         params = json_array_create_2(json_clone(aux.monitor->monitor_id),
 930                                      aux.json);
 931         msg = jsonrpc_create_notify("update", params);
 932         jsonrpc_session_send(aux.monitor->session->js, msg);
 933     }
 934
 935     return NULL;
 936 }
 937
 938 static struct json *
 939 ovsdb_jsonrpc_monitor_get_initial(const struct ovsdb_jsonrpc_monitor *m)
 940 {
 941     struct ovsdb_jsonrpc_monitor_aux aux;
 942     struct shash_node *node;
 943
 944     ovsdb_jsonrpc_monitor_init_aux(&aux, m, true);
 945     SHASH_FOR_EACH (node, &m->tables) {
 946         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
 947
 948         if (mt->select & OJMS_INITIAL) {
 949             struct ovsdb_row *row;
 950
 951             HMAP_FOR_EACH (row, struct ovsdb_row, hmap_node,
 952                            &mt->table->rows) {
 953                 ovsdb_jsonrpc_monitor_change_cb(NULL, row, &aux);
 954             }
 955         }
 956     }
 957     return aux.json ? aux.json : json_object_create();
 958 }
 959
 960 static void
 961 ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *replica)
 962 {
 963     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
 964     struct shash_node *node;
 965
 966     json_destroy(m->monitor_id);
 967     SHASH_FOR_EACH (node, &m->tables) {
 968         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
 969         ovsdb_column_set_destroy(&mt->columns);
 970         free(mt);
 971     }
 972     shash_destroy(&m->tables);
 973     hmap_remove(&m->session->monitors, &m->node);
 974     free(m);
 975 }
 976
 977 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class = {
 978     ovsdb_jsonrpc_monitor_commit,
 979     ovsdb_jsonrpc_monitor_destroy
 980 };