ovsdb/jsonrpc-server.c

   1 /* Copyright (c) 2009, 2010 Nicira Networks
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include <config.h>
  17
  18 #include "jsonrpc-server.h"
  19
  20 #include <assert.h>
  21 #include <errno.h>
  22
  23 #include "bitmap.h"
  24 #include "column.h"
  25 #include "json.h"
  26 #include "jsonrpc.h"
  27 #include "ovsdb-error.h"
  28 #include "ovsdb-parser.h"
  29 #include "ovsdb.h"
  30 #include "reconnect.h"
  31 #include "row.h"
  32 #include "stream.h"
  33 #include "table.h"
  34 #include "timeval.h"
  35 #include "transaction.h"
  36 #include "trigger.h"
  37
  38 #define THIS_MODULE VLM_ovsdb_jsonrpc_server
  39 #include "vlog.h"
  40
  41 struct ovsdb_jsonrpc_remote;
  42 struct ovsdb_jsonrpc_session;
  43
  44 /* Message rate-limiting. */
  45 struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
  46
  47 /* Sessions. */
  48 static struct ovsdb_jsonrpc_session *ovsdb_jsonrpc_session_create(
  49     struct ovsdb_jsonrpc_remote *, struct jsonrpc_session *);
  50 static void ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *);
  51 static void ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *);
  52 static void ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *);
  53
  54 /* Triggers. */
  55 static void ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *,
  56                                          struct json *id, struct json *params);
  57 static struct ovsdb_jsonrpc_trigger *ovsdb_jsonrpc_trigger_find(
  58     struct ovsdb_jsonrpc_session *, const struct json *id, size_t hash);
  59 static void ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *);
  60 static void ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *);
  61 static void ovsdb_jsonrpc_trigger_complete_done(
  62     struct ovsdb_jsonrpc_session *);
  63
  64 /* Monitors. */
  65 static struct json *ovsdb_jsonrpc_monitor_create(
  66     struct ovsdb_jsonrpc_session *, struct json *params);
  67 static struct jsonrpc_msg *ovsdb_jsonrpc_monitor_cancel(
  68     struct ovsdb_jsonrpc_session *,
  69     struct json_array *params,
  70     const struct json *request_id);
  71 static void ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *);
  72 \f
  73 /* JSON-RPC database server. */
  74
  75 struct ovsdb_jsonrpc_server {
  76     struct ovsdb *db;
  77     unsigned int n_sessions, max_sessions;
  78     struct shash remotes;      /* Contains "struct ovsdb_jsonrpc_remote *"s. */
  79 };
  80
  81 /* A configured remote.  This is either a passive stream listener plus a list
  82  * of the currently connected sessions, or a list of exactly one active
  83  * session. */
  84 struct ovsdb_jsonrpc_remote {
  85     struct ovsdb_jsonrpc_server *server;
  86     struct pstream *listener;   /* Listener, if passive. */
  87     struct list sessions;       /* List of "struct ovsdb_jsonrpc_session"s. */
  88 };
  89
  90 static void ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *,
  91                                             const char *name);
  92 static void ovsdb_jsonrpc_server_del_remote(struct shash_node *);
  93
  94 struct ovsdb_jsonrpc_server *
  95 ovsdb_jsonrpc_server_create(struct ovsdb *db)
  96 {
  97     struct ovsdb_jsonrpc_server *server = xzalloc(sizeof *server);
  98     server->db = db;
  99     server->max_sessions = 64;
 100     shash_init(&server->remotes);
 101     return server;
 102 }
 103
 104 void
 105 ovsdb_jsonrpc_server_destroy(struct ovsdb_jsonrpc_server *svr)
 106 {
 107     struct shash_node *node, *next;
 108
 109     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
 110         ovsdb_jsonrpc_server_del_remote(node);
 111     }
 112     shash_destroy(&svr->remotes);
 113     free(svr);
 114 }
 115
 116 /* Sets 'svr''s current set of remotes to the names in 'new_remotes'.  The data
 117  * values in 'new_remotes' are ignored.
 118  *
 119  * A remote is an active or passive stream connection method, e.g. "pssl:" or
 120  * "tcp:1.2.3.4". */
 121 void
 122 ovsdb_jsonrpc_server_set_remotes(struct ovsdb_jsonrpc_server *svr,
 123                                  const struct shash *new_remotes)
 124 {
 125     struct shash_node *node, *next;
 126
 127     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
 128         if (!shash_find(new_remotes, node->name)) {
 129             ovsdb_jsonrpc_server_del_remote(node);
 130         }
 131     }
 132     SHASH_FOR_EACH (node, new_remotes) {
 133         if (!shash_find(&svr->remotes, node->name)) {
 134             ovsdb_jsonrpc_server_add_remote(svr, node->name);
 135         }
 136     }
 137 }
 138
 139 static void
 140 ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *svr,
 141                                 const char *name)
 142 {
 143     struct ovsdb_jsonrpc_remote *remote;
 144     struct pstream *listener;
 145     int error;
 146
 147     error = pstream_open(name, &listener);
 148     if (error && error != EAFNOSUPPORT) {
 149         VLOG_ERR_RL(&rl, "%s: listen failed: %s", name, strerror(error));
 150         return;
 151     }
 152
 153     remote = xmalloc(sizeof *remote);
 154     remote->server = svr;
 155     remote->listener = listener;
 156     list_init(&remote->sessions);
 157     shash_add(&svr->remotes, name, remote);
 158
 159     if (!listener) {
 160         ovsdb_jsonrpc_session_create(remote, jsonrpc_session_open(name));
 161     }
 162 }
 163
 164 static void
 165 ovsdb_jsonrpc_server_del_remote(struct shash_node *node)
 166 {
 167     struct ovsdb_jsonrpc_remote *remote = node->data;
 168
 169     ovsdb_jsonrpc_session_close_all(remote);
 170     pstream_close(remote->listener);
 171     shash_delete(&remote->server->remotes, node);
 172     free(remote);
 173 }
 174
 175 void
 176 ovsdb_jsonrpc_server_run(struct ovsdb_jsonrpc_server *svr)
 177 {
 178     struct shash_node *node;
 179
 180     SHASH_FOR_EACH (node, &svr->remotes) {
 181         struct ovsdb_jsonrpc_remote *remote = node->data;
 182
 183         if (remote->listener && svr->n_sessions < svr->max_sessions) {
 184             struct stream *stream;
 185             int error;
 186
 187             error = pstream_accept(remote->listener, &stream);
 188             if (!error) {
 189                 struct jsonrpc_session *js;
 190                 js = jsonrpc_session_open_unreliably(jsonrpc_open(stream));
 191                 ovsdb_jsonrpc_session_create(remote, js);
 192             } else if (error != EAGAIN) {
 193                 VLOG_WARN_RL(&rl, "%s: accept failed: %s",
 194                              pstream_get_name(remote->listener),
 195                              strerror(error));
 196             }
 197         }
 198
 199         ovsdb_jsonrpc_session_run_all(remote);
 200     }
 201 }
 202
 203 void
 204 ovsdb_jsonrpc_server_wait(struct ovsdb_jsonrpc_server *svr)
 205 {
 206     struct shash_node *node;
 207
 208     SHASH_FOR_EACH (node, &svr->remotes) {
 209         struct ovsdb_jsonrpc_remote *remote = node->data;
 210
 211         if (remote->listener && svr->n_sessions < svr->max_sessions) {
 212             pstream_wait(remote->listener);
 213         }
 214
 215         ovsdb_jsonrpc_session_wait_all(remote);
 216     }
 217 }
 218 \f
 219 /* JSON-RPC database server session. */
 220
 221 struct ovsdb_jsonrpc_session {
 222     struct ovsdb_jsonrpc_remote *remote;
 223     struct list node;           /* Element in remote's sessions list. */
 224
 225     /* Triggers. */
 226     struct hmap triggers;       /* Hmap of "struct ovsdb_jsonrpc_trigger"s. */
 227     struct list completions;    /* Completed triggers. */
 228
 229     /* Monitors. */
 230     struct hmap monitors;       /* Hmap of "struct ovsdb_jsonrpc_monitor"s. */
 231
 232     /* Network connectivity. */
 233     struct jsonrpc_session *js;  /* JSON-RPC session. */
 234     unsigned int js_seqno;       /* Last jsonrpc_session_get_seqno() value. */
 235 };
 236
 237 static void ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *);
 238 static int ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *);
 239 static void ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *);
 240 static void ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *,
 241                                              struct jsonrpc_msg *);
 242 static void ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *,
 243                                              struct jsonrpc_msg *);
 244
 245 static struct ovsdb_jsonrpc_session *
 246 ovsdb_jsonrpc_session_create(struct ovsdb_jsonrpc_remote *remote,
 247                              struct jsonrpc_session *js)
 248 {
 249     struct ovsdb_jsonrpc_session *s;
 250
 251     s = xzalloc(sizeof *s);
 252     s->remote = remote;
 253     list_push_back(&remote->sessions, &s->node);
 254     hmap_init(&s->triggers);
 255     hmap_init(&s->monitors);
 256     list_init(&s->completions);
 257     s->js = js;
 258     s->js_seqno = jsonrpc_session_get_seqno(js);
 259
 260     remote->server->n_sessions++;
 261
 262     return s;
 263 }
 264
 265 static void
 266 ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *s)
 267 {
 268     ovsdb_jsonrpc_monitor_remove_all(s);
 269     jsonrpc_session_close(s->js);
 270     list_remove(&s->node);
 271     s->remote->server->n_sessions--;
 272     free(s);
 273 }
 274
 275 static int
 276 ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *s)
 277 {
 278     jsonrpc_session_run(s->js);
 279     if (s->js_seqno != jsonrpc_session_get_seqno(s->js)) {
 280         s->js_seqno = jsonrpc_session_get_seqno(s->js);
 281         ovsdb_jsonrpc_trigger_complete_all(s);
 282         ovsdb_jsonrpc_monitor_remove_all(s);
 283     }
 284
 285     ovsdb_jsonrpc_trigger_complete_done(s);
 286
 287     if (!jsonrpc_session_get_backlog(s->js)) {
 288         struct jsonrpc_msg *msg = jsonrpc_session_recv(s->js);
 289         if (msg) {
 290             if (msg->type == JSONRPC_REQUEST) {
 291                 ovsdb_jsonrpc_session_got_request(s, msg);
 292             } else if (msg->type == JSONRPC_NOTIFY) {
 293                 ovsdb_jsonrpc_session_got_notify(s, msg);
 294             } else {
 295                 VLOG_WARN("%s: received unexpected %s message",
 296                           jsonrpc_session_get_name(s->js),
 297                           jsonrpc_msg_type_to_string(msg->type));
 298                 jsonrpc_session_force_reconnect(s->js);
 299                 jsonrpc_msg_destroy(msg);
 300             }
 301         }
 302     }
 303     return jsonrpc_session_is_alive(s->js) ? 0 : ETIMEDOUT;
 304 }
 305
 306 static void
 307 ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *remote)
 308 {
 309     struct ovsdb_jsonrpc_session *s, *next;
 310
 311     LIST_FOR_EACH_SAFE (s, next, struct ovsdb_jsonrpc_session, node,
 312                         &remote->sessions) {
 313         int error = ovsdb_jsonrpc_session_run(s);
 314         if (error) {
 315             ovsdb_jsonrpc_session_close(s);
 316         }
 317     }
 318 }
 319
 320 static void
 321 ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *s)
 322 {
 323     jsonrpc_session_wait(s->js);
 324     if (!jsonrpc_session_get_backlog(s->js)) {
 325         jsonrpc_session_recv_wait(s->js);
 326     }
 327 }
 328
 329 static void
 330 ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *remote)
 331 {
 332     struct ovsdb_jsonrpc_session *s;
 333
 334     LIST_FOR_EACH (s, struct ovsdb_jsonrpc_session, node, &remote->sessions) {
 335         ovsdb_jsonrpc_session_wait(s);
 336     }
 337 }
 338
 339 static void
 340 ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *remote)
 341 {
 342     struct ovsdb_jsonrpc_session *s, *next;
 343
 344     LIST_FOR_EACH_SAFE (s, next, struct ovsdb_jsonrpc_session, node,
 345                         &remote->sessions) {
 346         ovsdb_jsonrpc_session_close(s);
 347     }
 348 }
 349
 350 static const char *
 351 get_db_name(const struct ovsdb_jsonrpc_session *s)
 352 {
 353     return s->remote->server->db->schema->name;
 354 }
 355
 356 static struct jsonrpc_msg *
 357 ovsdb_jsonrpc_check_db_name(const struct ovsdb_jsonrpc_session *s,
 358                             const struct jsonrpc_msg *request)
 359 {
 360     struct json_array *params;
 361     const char *want_db_name;
 362     const char *have_db_name;
 363     struct ovsdb_error *error;
 364     struct jsonrpc_msg *reply;
 365
 366     params = json_array(request->params);
 367     if (!params->n || params->elems[0]->type != JSON_STRING) {
 368         error = ovsdb_syntax_error(
 369             request->params, NULL,
 370             "%s request params must begin with <db-name>", request->method);
 371         goto error;
 372     }
 373
 374     want_db_name = params->elems[0]->u.string;
 375     have_db_name = get_db_name(s);
 376     if (strcmp(want_db_name, have_db_name)) {
 377         error = ovsdb_syntax_error(
 378             request->params, "unknown database",
 379             "%s request specifies unknown database %s",
 380             request->method, want_db_name);
 381         goto error;
 382     }
 383
 384     return NULL;
 385
 386 error:
 387     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
 388     ovsdb_error_destroy(error);
 389     return reply;
 390 }
 391
 392 static struct jsonrpc_msg *
 393 execute_transaction(struct ovsdb_jsonrpc_session *s,
 394                     struct jsonrpc_msg *request)
 395 {
 396     ovsdb_jsonrpc_trigger_create(s, request->id, request->params);
 397     request->id = NULL;
 398     request->params = NULL;
 399     jsonrpc_msg_destroy(request);
 400     return NULL;
 401 }
 402
 403 static void
 404 ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *s,
 405                                   struct jsonrpc_msg *request)
 406 {
 407     struct jsonrpc_msg *reply;
 408
 409     if (!strcmp(request->method, "transact")) {
 410         reply = ovsdb_jsonrpc_check_db_name(s, request);
 411         if (!reply) {
 412             reply = execute_transaction(s, request);
 413         }
 414     } else if (!strcmp(request->method, "monitor")) {
 415         reply = ovsdb_jsonrpc_check_db_name(s, request);
 416         if (!reply) {
 417             reply = jsonrpc_create_reply(
 418                 ovsdb_jsonrpc_monitor_create(s, request->params), request->id);
 419         }
 420     } else if (!strcmp(request->method, "monitor_cancel")) {
 421         reply = ovsdb_jsonrpc_monitor_cancel(s, json_array(request->params),
 422                                              request->id);
 423     } else if (!strcmp(request->method, "get_schema")) {
 424         reply = ovsdb_jsonrpc_check_db_name(s, request);
 425         if (!reply) {
 426             reply = jsonrpc_create_reply(
 427                 ovsdb_schema_to_json(s->remote->server->db->schema),
 428                 request->id);
 429         }
 430     } else if (!strcmp(request->method, "list_dbs")) {
 431         reply = jsonrpc_create_reply(
 432             json_array_create_1(json_string_create(get_db_name(s))),
 433             request->id);
 434     } else if (!strcmp(request->method, "echo")) {
 435         reply = jsonrpc_create_reply(json_clone(request->params), request->id);
 436     } else {
 437         reply = jsonrpc_create_error(json_string_create("unknown method"),
 438                                      request->id);
 439     }
 440
 441     if (reply) {
 442         jsonrpc_msg_destroy(request);
 443         jsonrpc_session_send(s->js, reply);
 444     }
 445 }
 446
 447 static void
 448 execute_cancel(struct ovsdb_jsonrpc_session *s, struct jsonrpc_msg *request)
 449 {
 450     if (json_array(request->params)->n == 1) {
 451         struct ovsdb_jsonrpc_trigger *t;
 452         struct json *id;
 453
 454         id = request->params->u.array.elems[0];
 455         t = ovsdb_jsonrpc_trigger_find(s, id, json_hash(id, 0));
 456         if (t) {
 457             ovsdb_jsonrpc_trigger_complete(t);
 458         }
 459     }
 460 }
 461
 462 static void
 463 ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *s,
 464                                  struct jsonrpc_msg *request)
 465 {
 466     if (!strcmp(request->method, "cancel")) {
 467         execute_cancel(s, request);
 468     }
 469     jsonrpc_msg_destroy(request);
 470 }
 471 \f
 472 /* JSON-RPC database server triggers.
 473  *
 474  * (Every transaction is treated as a trigger even if it doesn't actually have
 475  * any "wait" operations.) */
 476
 477 struct ovsdb_jsonrpc_trigger {
 478     struct ovsdb_trigger trigger;
 479     struct ovsdb_jsonrpc_session *session;
 480     struct hmap_node hmap_node; /* In session's "triggers" hmap. */
 481     struct json *id;
 482 };
 483
 484 static void
 485 ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *s,
 486                              struct json *id, struct json *params)
 487 {
 488     struct ovsdb_jsonrpc_trigger *t;
 489     size_t hash;
 490
 491     /* Check for duplicate ID. */
 492     hash = json_hash(id, 0);
 493     t = ovsdb_jsonrpc_trigger_find(s, id, hash);
 494     if (t) {
 495         struct jsonrpc_msg *msg;
 496
 497         msg = jsonrpc_create_error(json_string_create("duplicate request ID"),
 498                                    id);
 499         jsonrpc_session_send(s->js, msg);
 500         json_destroy(id);
 501         json_destroy(params);
 502         return;
 503     }
 504
 505     /* Insert into trigger table. */
 506     t = xmalloc(sizeof *t);
 507     ovsdb_trigger_init(s->remote->server->db,
 508                        &t->trigger, params, &s->completions,
 509                        time_msec());
 510     t->session = s;
 511     t->id = id;
 512     hmap_insert(&s->triggers, &t->hmap_node, hash);
 513
 514     /* Complete early if possible. */
 515     if (ovsdb_trigger_is_complete(&t->trigger)) {
 516         ovsdb_jsonrpc_trigger_complete(t);
 517     }
 518 }
 519
 520 static struct ovsdb_jsonrpc_trigger *
 521 ovsdb_jsonrpc_trigger_find(struct ovsdb_jsonrpc_session *s,
 522                            const struct json *id, size_t hash)
 523 {
 524     struct ovsdb_jsonrpc_trigger *t;
 525
 526     HMAP_FOR_EACH_WITH_HASH (t, struct ovsdb_jsonrpc_trigger, hmap_node, hash,
 527                              &s->triggers) {
 528         if (json_equal(t->id, id)) {
 529             return t;
 530         }
 531     }
 532
 533     return NULL;
 534 }
 535
 536 static void
 537 ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *t)
 538 {
 539     struct ovsdb_jsonrpc_session *s = t->session;
 540
 541     if (jsonrpc_session_is_connected(s->js)) {
 542         struct jsonrpc_msg *reply;
 543         struct json *result;
 544
 545         result = ovsdb_trigger_steal_result(&t->trigger);
 546         if (result) {
 547             reply = jsonrpc_create_reply(result, t->id);
 548         } else {
 549             reply = jsonrpc_create_error(json_string_create("canceled"),
 550                                          t->id);
 551         }
 552         jsonrpc_session_send(s->js, reply);
 553     }
 554
 555     json_destroy(t->id);
 556     ovsdb_trigger_destroy(&t->trigger);
 557     hmap_remove(&s->triggers, &t->hmap_node);
 558     free(t);
 559 }
 560
 561 static void
 562 ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *s)
 563 {
 564     struct ovsdb_jsonrpc_trigger *t, *next;
 565     HMAP_FOR_EACH_SAFE (t, next, struct ovsdb_jsonrpc_trigger, hmap_node,
 566                         &s->triggers) {
 567         ovsdb_jsonrpc_trigger_complete(t);
 568     }
 569 }
 570
 571 static void
 572 ovsdb_jsonrpc_trigger_complete_done(struct ovsdb_jsonrpc_session *s)
 573 {
 574     while (!list_is_empty(&s->completions)) {
 575         struct ovsdb_jsonrpc_trigger *t
 576             = CONTAINER_OF(s->completions.next,
 577                            struct ovsdb_jsonrpc_trigger, trigger.node);
 578         ovsdb_jsonrpc_trigger_complete(t);
 579     }
 580 }
 581 \f
 582 /* JSON-RPC database table monitors. */
 583
 584 enum ovsdb_jsonrpc_monitor_selection {
 585     OJMS_INITIAL = 1 << 0,      /* All rows when monitor is created. */
 586     OJMS_INSERT = 1 << 1,       /* New rows. */
 587     OJMS_DELETE = 1 << 2,       /* Deleted rows. */
 588     OJMS_MODIFY = 1 << 3        /* Modified rows. */
 589 };
 590
 591 struct ovsdb_jsonrpc_monitor_table {
 592     const struct ovsdb_table *table;
 593     enum ovsdb_jsonrpc_monitor_selection select;
 594     struct ovsdb_column_set columns;
 595 };
 596
 597 struct ovsdb_jsonrpc_monitor {
 598     struct ovsdb_replica replica;
 599     struct ovsdb_jsonrpc_session *session;
 600     struct hmap_node node;      /* In ovsdb_jsonrpc_session's "monitors". */
 601
 602     struct json *monitor_id;
 603     struct shash tables;     /* Holds "struct ovsdb_jsonrpc_monitor_table"s. */
 604 };
 605
 606 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class;
 607
 608 struct ovsdb_jsonrpc_monitor *ovsdb_jsonrpc_monitor_find(
 609     struct ovsdb_jsonrpc_session *, const struct json *monitor_id);
 610 static void ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *);
 611 static struct json *ovsdb_jsonrpc_monitor_get_initial(
 612     const struct ovsdb_jsonrpc_monitor *);
 613
 614 static bool
 615 parse_bool(struct ovsdb_parser *parser, const char *name, bool default_value)
 616 {
 617     const struct json *json;
 618
 619     json = ovsdb_parser_member(parser, name, OP_BOOLEAN | OP_OPTIONAL);
 620     return json ? json_boolean(json) : default_value;
 621 }
 622
 623 struct ovsdb_jsonrpc_monitor *
 624 ovsdb_jsonrpc_monitor_find(struct ovsdb_jsonrpc_session *s,
 625                            const struct json *monitor_id)
 626 {
 627     struct ovsdb_jsonrpc_monitor *m;
 628
 629     HMAP_FOR_EACH_WITH_HASH (m, struct ovsdb_jsonrpc_monitor, node,
 630                              json_hash(monitor_id, 0), &s->monitors) {
 631         if (json_equal(m->monitor_id, monitor_id)) {
 632             return m;
 633         }
 634     }
 635
 636     return NULL;
 637 }
 638
 639 static struct json *
 640 ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s,
 641                              struct json *params)
 642 {
 643     struct ovsdb_jsonrpc_monitor *m = NULL;
 644     struct json *monitor_id, *monitor_requests;
 645     struct ovsdb_error *error = NULL;
 646     struct shash_node *node;
 647     struct json *json;
 648
 649     if (json_array(params)->n != 3) {
 650         error = ovsdb_syntax_error(params, NULL, "invalid parameters");
 651         goto error;
 652     }
 653     monitor_id = params->u.array.elems[1];
 654     monitor_requests = params->u.array.elems[2];
 655     if (monitor_requests->type != JSON_OBJECT) {
 656         error = ovsdb_syntax_error(monitor_requests, NULL,
 657                                    "monitor-requests must be object");
 658         goto error;
 659     }
 660
 661     if (ovsdb_jsonrpc_monitor_find(s, monitor_id)) {
 662         error = ovsdb_syntax_error(monitor_id, NULL, "duplicate monitor ID");
 663         goto error;
 664     }
 665
 666     m = xzalloc(sizeof *m);
 667     ovsdb_replica_init(&m->replica, &ovsdb_jsonrpc_replica_class);
 668     ovsdb_add_replica(s->remote->server->db, &m->replica);
 669     m->session = s;
 670     hmap_insert(&s->monitors, &m->node, json_hash(monitor_id, 0));
 671     m->monitor_id = json_clone(monitor_id);
 672     shash_init(&m->tables);
 673
 674     SHASH_FOR_EACH (node, json_object(monitor_requests)) {
 675         const struct ovsdb_table *table;
 676         struct ovsdb_jsonrpc_monitor_table *mt;
 677         const struct json *columns_json, *select_json;
 678         struct ovsdb_parser parser;
 679
 680         table = ovsdb_get_table(s->remote->server->db, node->name);
 681         if (!table) {
 682             error = ovsdb_syntax_error(NULL, NULL,
 683                                        "no table named %s", node->name);
 684             goto error;
 685         }
 686
 687         mt = xzalloc(sizeof *mt);
 688         mt->table = table;
 689         mt->select = OJMS_INITIAL | OJMS_INSERT | OJMS_DELETE | OJMS_MODIFY;
 690         ovsdb_column_set_init(&mt->columns);
 691         shash_add(&m->tables, table->schema->name, mt);
 692
 693         ovsdb_parser_init(&parser, node->data, "table %s", node->name);
 694         columns_json = ovsdb_parser_member(&parser, "columns",
 695                                            OP_ARRAY | OP_OPTIONAL);
 696         select_json = ovsdb_parser_member(&parser, "select",
 697                                           OP_OBJECT | OP_OPTIONAL);
 698         error = ovsdb_parser_finish(&parser);
 699         if (error) {
 700             goto error;
 701         }
 702
 703         if (columns_json) {
 704             error = ovsdb_column_set_from_json(columns_json, table,
 705                                                &mt->columns);
 706             if (error) {
 707                 goto error;
 708             }
 709         } else {
 710             struct shash_node *node;
 711
 712             SHASH_FOR_EACH (node, &table->schema->columns) {
 713                 const struct ovsdb_column *column = node->data;
 714                 if (column->index != OVSDB_COL_UUID) {
 715                     ovsdb_column_set_add(&mt->columns, column);
 716                 }
 717             }
 718         }
 719
 720         if (select_json) {
 721             mt->select = 0;
 722             ovsdb_parser_init(&parser, select_json, "table %s select",
 723                               table->schema->name);
 724             if (parse_bool(&parser, "initial", true)) {
 725                 mt->select |= OJMS_INITIAL;
 726             }
 727             if (parse_bool(&parser, "insert", true)) {
 728                 mt->select |= OJMS_INSERT;
 729             }
 730             if (parse_bool(&parser, "delete", true)) {
 731                 mt->select |= OJMS_DELETE;
 732             }
 733             if (parse_bool(&parser, "modify", true)) {
 734                 mt->select |= OJMS_MODIFY;
 735             }
 736             error = ovsdb_parser_finish(&parser);
 737             if (error) {
 738                 goto error;
 739             }
 740         }
 741     }
 742
 743     return ovsdb_jsonrpc_monitor_get_initial(m);
 744
 745 error:
 746     if (m) {
 747         ovsdb_remove_replica(s->remote->server->db, &m->replica);
 748     }
 749
 750     json = ovsdb_error_to_json(error);
 751     ovsdb_error_destroy(error);
 752     return json;
 753 }
 754
 755 static struct jsonrpc_msg *
 756 ovsdb_jsonrpc_monitor_cancel(struct ovsdb_jsonrpc_session *s,
 757                              struct json_array *params,
 758                              const struct json *request_id)
 759 {
 760     if (params->n != 1) {
 761         return jsonrpc_create_error(json_string_create("invalid parameters"),
 762                                     request_id);
 763     } else {
 764         struct ovsdb_jsonrpc_monitor *m;
 765
 766         m = ovsdb_jsonrpc_monitor_find(s, params->elems[0]);
 767         if (!m) {
 768             return jsonrpc_create_error(json_string_create("unknown monitor"),
 769                                         request_id);
 770         } else {
 771             ovsdb_remove_replica(s->remote->server->db, &m->replica);
 772             return jsonrpc_create_reply(json_object_create(), request_id);
 773         }
 774     }
 775 }
 776
 777 static void
 778 ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *s)
 779 {
 780     struct ovsdb_jsonrpc_monitor *m, *next;
 781
 782     HMAP_FOR_EACH_SAFE (m, next,
 783                         struct ovsdb_jsonrpc_monitor, node, &s->monitors) {
 784         ovsdb_remove_replica(s->remote->server->db, &m->replica);
 785     }
 786 }
 787
 788 static struct ovsdb_jsonrpc_monitor *
 789 ovsdb_jsonrpc_monitor_cast(struct ovsdb_replica *replica)
 790 {
 791     assert(replica->class == &ovsdb_jsonrpc_replica_class);
 792     return CONTAINER_OF(replica, struct ovsdb_jsonrpc_monitor, replica);
 793 }
 794
 795 struct ovsdb_jsonrpc_monitor_aux {
 796     bool initial;               /* Sending initial contents of table? */
 797     const struct ovsdb_jsonrpc_monitor *monitor;
 798     struct json *json;          /* JSON for the whole transaction. */
 799
 800     /* Current table.  */
 801     struct ovsdb_jsonrpc_monitor_table *mt;
 802     struct json *table_json;    /* JSON for table's transaction. */
 803 };
 804
 805 static bool
 806 ovsdb_jsonrpc_monitor_change_cb(const struct ovsdb_row *old,
 807                                 const struct ovsdb_row *new,
 808                                 const unsigned long int *changed,
 809                                 void *aux_)
 810 {
 811     struct ovsdb_jsonrpc_monitor_aux *aux = aux_;
 812     const struct ovsdb_jsonrpc_monitor *m = aux->monitor;
 813     struct ovsdb_table *table = new ? new->table : old->table;
 814     enum ovsdb_jsonrpc_monitor_selection type;
 815     struct json *old_json, *new_json;
 816     struct json *row_json;
 817     char uuid[UUID_LEN + 1];
 818     int n_changed;
 819     size_t i;
 820
 821     if (!aux->mt || table != aux->mt->table) {
 822         aux->mt = shash_find_data(&m->tables, table->schema->name);
 823         aux->table_json = NULL;
 824         if (!aux->mt) {
 825             /* We don't care about rows in this table at all.  Tell the caller
 826              * to skip it.  */
 827             return false;
 828         }
 829     }
 830
 831     type = (aux->initial ? OJMS_INITIAL
 832             : !old ? OJMS_INSERT
 833             : !new ? OJMS_DELETE
 834             : OJMS_MODIFY);
 835     if (!(aux->mt->select & type)) {
 836         /* We don't care about this type of change (but do want to be called
 837          * back for changes to other rows in the same table). */
 838         return true;
 839     }
 840
 841     old_json = new_json = NULL;
 842     n_changed = 0;
 843     for (i = 0; i < aux->mt->columns.n_columns; i++) {
 844         const struct ovsdb_column *column = aux->mt->columns.columns[i];
 845         unsigned int idx = column->index;
 846         bool column_changed = false;
 847
 848         if (type == OJMS_MODIFY) {
 849             column_changed = bitmap_is_set(changed, idx);
 850             n_changed += column_changed;
 851         }
 852         if (column_changed || type == OJMS_DELETE) {
 853             if (!old_json) {
 854                 old_json = json_object_create();
 855             }
 856             json_object_put(old_json, column->name,
 857                             ovsdb_datum_to_json(&old->fields[idx],
 858                                                 &column->type));
 859         }
 860         if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
 861             if (!new_json) {
 862                 new_json = json_object_create();
 863             }
 864             json_object_put(new_json, column->name,
 865                             ovsdb_datum_to_json(&new->fields[idx],
 866                                                 &column->type));
 867         }
 868     }
 869     if ((type == OJMS_MODIFY && !n_changed) || (!old_json && !new_json)) {
 870         /* No reportable changes. */
 871         json_destroy(old_json);
 872         json_destroy(new_json);
 873         return true;
 874     }
 875
 876     /* Create JSON object for transaction overall. */
 877     if (!aux->json) {
 878         aux->json = json_object_create();
 879     }
 880
 881     /* Create JSON object for transaction on this table. */
 882     if (!aux->table_json) {
 883         aux->table_json = json_object_create();
 884         json_object_put(aux->json, aux->mt->table->schema->name,
 885                         aux->table_json);
 886     }
 887
 888     /* Create JSON object for transaction on this row. */
 889     row_json = json_object_create();
 890     if (old_json) {
 891         json_object_put(row_json, "old", old_json);
 892     }
 893     if (new_json) {
 894         json_object_put(row_json, "new", new_json);
 895     }
 896
 897     /* Add JSON row to JSON table. */
 898     snprintf(uuid, sizeof uuid,
 899              UUID_FMT, UUID_ARGS(ovsdb_row_get_uuid(new ? new : old)));
 900     json_object_put(aux->table_json, uuid, row_json);
 901
 902     return true;
 903 }
 904
 905 static void
 906 ovsdb_jsonrpc_monitor_init_aux(struct ovsdb_jsonrpc_monitor_aux *aux,
 907                                const struct ovsdb_jsonrpc_monitor *m,
 908                                bool initial)
 909 {
 910     aux->initial = initial;
 911     aux->monitor = m;
 912     aux->json = NULL;
 913     aux->mt = NULL;
 914     aux->table_json = NULL;
 915 }
 916
 917 static struct ovsdb_error *
 918 ovsdb_jsonrpc_monitor_commit(struct ovsdb_replica *replica,
 919                              const struct ovsdb_txn *txn,
 920                              bool durable OVS_UNUSED)
 921 {
 922     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
 923     struct ovsdb_jsonrpc_monitor_aux aux;
 924
 925     ovsdb_jsonrpc_monitor_init_aux(&aux, m, false);
 926     ovsdb_txn_for_each_change(txn, ovsdb_jsonrpc_monitor_change_cb, &aux);
 927     if (aux.json) {
 928         struct jsonrpc_msg *msg;
 929         struct json *params;
 930
 931         params = json_array_create_2(json_clone(aux.monitor->monitor_id),
 932                                      aux.json);
 933         msg = jsonrpc_create_notify("update", params);
 934         jsonrpc_session_send(aux.monitor->session->js, msg);
 935     }
 936
 937     return NULL;
 938 }
 939
 940 static struct json *
 941 ovsdb_jsonrpc_monitor_get_initial(const struct ovsdb_jsonrpc_monitor *m)
 942 {
 943     struct ovsdb_jsonrpc_monitor_aux aux;
 944     struct shash_node *node;
 945
 946     ovsdb_jsonrpc_monitor_init_aux(&aux, m, true);
 947     SHASH_FOR_EACH (node, &m->tables) {
 948         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
 949
 950         if (mt->select & OJMS_INITIAL) {
 951             struct ovsdb_row *row;
 952
 953             HMAP_FOR_EACH (row, struct ovsdb_row, hmap_node,
 954                            &mt->table->rows) {
 955                 ovsdb_jsonrpc_monitor_change_cb(NULL, row, NULL, &aux);
 956             }
 957         }
 958     }
 959     return aux.json ? aux.json : json_object_create();
 960 }
 961
 962 static void
 963 ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *replica)
 964 {
 965     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
 966     struct shash_node *node;
 967
 968     json_destroy(m->monitor_id);
 969     SHASH_FOR_EACH (node, &m->tables) {
 970         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
 971         ovsdb_column_set_destroy(&mt->columns);
 972         free(mt);
 973     }
 974     shash_destroy(&m->tables);
 975     hmap_remove(&m->session->monitors, &m->node);
 976     free(m);
 977 }
 978
 979 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class = {
 980     ovsdb_jsonrpc_monitor_commit,
 981     ovsdb_jsonrpc_monitor_destroy
 982 };