ovsdb/jsonrpc-server.c

   1 /* Copyright (c) 2009, 2010 Nicira Networks
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include <config.h>
  17
  18 #include "jsonrpc-server.h"
  19
  20 #include <assert.h>
  21 #include <errno.h>
  22
  23 #include "bitmap.h"
  24 #include "column.h"
  25 #include "json.h"
  26 #include "jsonrpc.h"
  27 #include "ovsdb-error.h"
  28 #include "ovsdb-parser.h"
  29 #include "ovsdb.h"
  30 #include "reconnect.h"
  31 #include "row.h"
  32 #include "stream.h"
  33 #include "table.h"
  34 #include "timeval.h"
  35 #include "transaction.h"
  36 #include "trigger.h"
  37 #include "vlog.h"
  38
  39 VLOG_DEFINE_THIS_MODULE(ovsdb_jsonrpc_server)
  40
  41 struct ovsdb_jsonrpc_remote;
  42 struct ovsdb_jsonrpc_session;
  43
  44 /* Message rate-limiting. */
  45 struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
  46
  47 /* Sessions. */
  48 static struct ovsdb_jsonrpc_session *ovsdb_jsonrpc_session_create(
  49     struct ovsdb_jsonrpc_remote *, struct jsonrpc_session *);
  50 static void ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *);
  51 static void ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *);
  52 static void ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *);
  53 static void ovsdb_jsonrpc_session_reconnect_all(struct ovsdb_jsonrpc_remote *);
  54
  55 /* Triggers. */
  56 static void ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *,
  57                                          struct json *id, struct json *params);
  58 static struct ovsdb_jsonrpc_trigger *ovsdb_jsonrpc_trigger_find(
  59     struct ovsdb_jsonrpc_session *, const struct json *id, size_t hash);
  60 static void ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *);
  61 static void ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *);
  62 static void ovsdb_jsonrpc_trigger_complete_done(
  63     struct ovsdb_jsonrpc_session *);
  64
  65 /* Monitors. */
  66 static struct json *ovsdb_jsonrpc_monitor_create(
  67     struct ovsdb_jsonrpc_session *, struct json *params);
  68 static struct jsonrpc_msg *ovsdb_jsonrpc_monitor_cancel(
  69     struct ovsdb_jsonrpc_session *,
  70     struct json_array *params,
  71     const struct json *request_id);
  72 static void ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *);
  73 \f
  74 /* JSON-RPC database server. */
  75
  76 struct ovsdb_jsonrpc_server {
  77     struct ovsdb *db;
  78     unsigned int n_sessions, max_sessions;
  79     struct shash remotes;      /* Contains "struct ovsdb_jsonrpc_remote *"s. */
  80 };
  81
  82 /* A configured remote.  This is either a passive stream listener plus a list
  83  * of the currently connected sessions, or a list of exactly one active
  84  * session. */
  85 struct ovsdb_jsonrpc_remote {
  86     struct ovsdb_jsonrpc_server *server;
  87     struct pstream *listener;   /* Listener, if passive. */
  88     struct list sessions;       /* List of "struct ovsdb_jsonrpc_session"s. */
  89 };
  90
  91 static void ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *,
  92                                             const char *name);
  93 static void ovsdb_jsonrpc_server_del_remote(struct shash_node *);
  94
  95 struct ovsdb_jsonrpc_server *
  96 ovsdb_jsonrpc_server_create(struct ovsdb *db)
  97 {
  98     struct ovsdb_jsonrpc_server *server = xzalloc(sizeof *server);
  99     server->db = db;
 100     server->max_sessions = 64;
 101     shash_init(&server->remotes);
 102     return server;
 103 }
 104
 105 void
 106 ovsdb_jsonrpc_server_destroy(struct ovsdb_jsonrpc_server *svr)
 107 {
 108     struct shash_node *node, *next;
 109
 110     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
 111         ovsdb_jsonrpc_server_del_remote(node);
 112     }
 113     shash_destroy(&svr->remotes);
 114     free(svr);
 115 }
 116
 117 /* Sets 'svr''s current set of remotes to the names in 'new_remotes'.  The data
 118  * values in 'new_remotes' are ignored.
 119  *
 120  * A remote is an active or passive stream connection method, e.g. "pssl:" or
 121  * "tcp:1.2.3.4". */
 122 void
 123 ovsdb_jsonrpc_server_set_remotes(struct ovsdb_jsonrpc_server *svr,
 124                                  const struct shash *new_remotes)
 125 {
 126     struct shash_node *node, *next;
 127
 128     SHASH_FOR_EACH_SAFE (node, next, &svr->remotes) {
 129         if (!shash_find(new_remotes, node->name)) {
 130             ovsdb_jsonrpc_server_del_remote(node);
 131         }
 132     }
 133     SHASH_FOR_EACH (node, new_remotes) {
 134         if (!shash_find(&svr->remotes, node->name)) {
 135             ovsdb_jsonrpc_server_add_remote(svr, node->name);
 136         }
 137     }
 138 }
 139
 140 static void
 141 ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *svr,
 142                                 const char *name)
 143 {
 144     struct ovsdb_jsonrpc_remote *remote;
 145     struct pstream *listener;
 146     int error;
 147
 148     error = jsonrpc_pstream_open(name, &listener);
 149     if (error && error != EAFNOSUPPORT) {
 150         VLOG_ERR_RL(&rl, "%s: listen failed: %s", name, strerror(error));
 151         return;
 152     }
 153
 154     remote = xmalloc(sizeof *remote);
 155     remote->server = svr;
 156     remote->listener = listener;
 157     list_init(&remote->sessions);
 158     shash_add(&svr->remotes, name, remote);
 159
 160     if (!listener) {
 161         ovsdb_jsonrpc_session_create(remote, jsonrpc_session_open(name));
 162     }
 163 }
 164
 165 static void
 166 ovsdb_jsonrpc_server_del_remote(struct shash_node *node)
 167 {
 168     struct ovsdb_jsonrpc_remote *remote = node->data;
 169
 170     ovsdb_jsonrpc_session_close_all(remote);
 171     pstream_close(remote->listener);
 172     shash_delete(&remote->server->remotes, node);
 173     free(remote);
 174 }
 175
 176 /* Forces all of the JSON-RPC sessions managed by 'svr' to disconnect and
 177  * reconnect. */
 178 void
 179 ovsdb_jsonrpc_server_reconnect(struct ovsdb_jsonrpc_server *svr)
 180 {
 181     struct shash_node *node;
 182
 183     SHASH_FOR_EACH (node, &svr->remotes) {
 184         struct ovsdb_jsonrpc_remote *remote = node->data;
 185
 186         ovsdb_jsonrpc_session_reconnect_all(remote);
 187     }
 188 }
 189
 190 void
 191 ovsdb_jsonrpc_server_run(struct ovsdb_jsonrpc_server *svr)
 192 {
 193     struct shash_node *node;
 194
 195     SHASH_FOR_EACH (node, &svr->remotes) {
 196         struct ovsdb_jsonrpc_remote *remote = node->data;
 197
 198         if (remote->listener && svr->n_sessions < svr->max_sessions) {
 199             struct stream *stream;
 200             int error;
 201
 202             error = pstream_accept(remote->listener, &stream);
 203             if (!error) {
 204                 struct jsonrpc_session *js;
 205                 js = jsonrpc_session_open_unreliably(jsonrpc_open(stream));
 206                 ovsdb_jsonrpc_session_create(remote, js);
 207             } else if (error != EAGAIN) {
 208                 VLOG_WARN_RL(&rl, "%s: accept failed: %s",
 209                              pstream_get_name(remote->listener),
 210                              strerror(error));
 211             }
 212         }
 213
 214         ovsdb_jsonrpc_session_run_all(remote);
 215     }
 216 }
 217
 218 void
 219 ovsdb_jsonrpc_server_wait(struct ovsdb_jsonrpc_server *svr)
 220 {
 221     struct shash_node *node;
 222
 223     SHASH_FOR_EACH (node, &svr->remotes) {
 224         struct ovsdb_jsonrpc_remote *remote = node->data;
 225
 226         if (remote->listener && svr->n_sessions < svr->max_sessions) {
 227             pstream_wait(remote->listener);
 228         }
 229
 230         ovsdb_jsonrpc_session_wait_all(remote);
 231     }
 232 }
 233 \f
 234 /* JSON-RPC database server session. */
 235
 236 struct ovsdb_jsonrpc_session {
 237     struct ovsdb_jsonrpc_remote *remote;
 238     struct list node;           /* Element in remote's sessions list. */
 239
 240     /* Triggers. */
 241     struct hmap triggers;       /* Hmap of "struct ovsdb_jsonrpc_trigger"s. */
 242     struct list completions;    /* Completed triggers. */
 243
 244     /* Monitors. */
 245     struct hmap monitors;       /* Hmap of "struct ovsdb_jsonrpc_monitor"s. */
 246
 247     /* Network connectivity. */
 248     struct jsonrpc_session *js;  /* JSON-RPC session. */
 249     unsigned int js_seqno;       /* Last jsonrpc_session_get_seqno() value. */
 250 };
 251
 252 static void ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *);
 253 static int ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *);
 254 static void ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *);
 255 static void ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *,
 256                                              struct jsonrpc_msg *);
 257 static void ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *,
 258                                              struct jsonrpc_msg *);
 259
 260 static struct ovsdb_jsonrpc_session *
 261 ovsdb_jsonrpc_session_create(struct ovsdb_jsonrpc_remote *remote,
 262                              struct jsonrpc_session *js)
 263 {
 264     struct ovsdb_jsonrpc_session *s;
 265
 266     s = xzalloc(sizeof *s);
 267     s->remote = remote;
 268     list_push_back(&remote->sessions, &s->node);
 269     hmap_init(&s->triggers);
 270     hmap_init(&s->monitors);
 271     list_init(&s->completions);
 272     s->js = js;
 273     s->js_seqno = jsonrpc_session_get_seqno(js);
 274
 275     remote->server->n_sessions++;
 276
 277     return s;
 278 }
 279
 280 static void
 281 ovsdb_jsonrpc_session_close(struct ovsdb_jsonrpc_session *s)
 282 {
 283     ovsdb_jsonrpc_monitor_remove_all(s);
 284     jsonrpc_session_close(s->js);
 285     list_remove(&s->node);
 286     s->remote->server->n_sessions--;
 287     free(s);
 288 }
 289
 290 static int
 291 ovsdb_jsonrpc_session_run(struct ovsdb_jsonrpc_session *s)
 292 {
 293     jsonrpc_session_run(s->js);
 294     if (s->js_seqno != jsonrpc_session_get_seqno(s->js)) {
 295         s->js_seqno = jsonrpc_session_get_seqno(s->js);
 296         ovsdb_jsonrpc_trigger_complete_all(s);
 297         ovsdb_jsonrpc_monitor_remove_all(s);
 298     }
 299
 300     ovsdb_jsonrpc_trigger_complete_done(s);
 301
 302     if (!jsonrpc_session_get_backlog(s->js)) {
 303         struct jsonrpc_msg *msg = jsonrpc_session_recv(s->js);
 304         if (msg) {
 305             if (msg->type == JSONRPC_REQUEST) {
 306                 ovsdb_jsonrpc_session_got_request(s, msg);
 307             } else if (msg->type == JSONRPC_NOTIFY) {
 308                 ovsdb_jsonrpc_session_got_notify(s, msg);
 309             } else {
 310                 VLOG_WARN("%s: received unexpected %s message",
 311                           jsonrpc_session_get_name(s->js),
 312                           jsonrpc_msg_type_to_string(msg->type));
 313                 jsonrpc_session_force_reconnect(s->js);
 314                 jsonrpc_msg_destroy(msg);
 315             }
 316         }
 317     }
 318     return jsonrpc_session_is_alive(s->js) ? 0 : ETIMEDOUT;
 319 }
 320
 321 static void
 322 ovsdb_jsonrpc_session_run_all(struct ovsdb_jsonrpc_remote *remote)
 323 {
 324     struct ovsdb_jsonrpc_session *s, *next;
 325
 326     LIST_FOR_EACH_SAFE (s, next, struct ovsdb_jsonrpc_session, node,
 327                         &remote->sessions) {
 328         int error = ovsdb_jsonrpc_session_run(s);
 329         if (error) {
 330             ovsdb_jsonrpc_session_close(s);
 331         }
 332     }
 333 }
 334
 335 static void
 336 ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *s)
 337 {
 338     jsonrpc_session_wait(s->js);
 339     if (!jsonrpc_session_get_backlog(s->js)) {
 340         jsonrpc_session_recv_wait(s->js);
 341     }
 342 }
 343
 344 static void
 345 ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *remote)
 346 {
 347     struct ovsdb_jsonrpc_session *s;
 348
 349     LIST_FOR_EACH (s, struct ovsdb_jsonrpc_session, node, &remote->sessions) {
 350         ovsdb_jsonrpc_session_wait(s);
 351     }
 352 }
 353
 354 static void
 355 ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *remote)
 356 {
 357     struct ovsdb_jsonrpc_session *s, *next;
 358
 359     LIST_FOR_EACH_SAFE (s, next, struct ovsdb_jsonrpc_session, node,
 360                         &remote->sessions) {
 361         ovsdb_jsonrpc_session_close(s);
 362     }
 363 }
 364
 365 /* Forces all of the JSON-RPC sessions managed by 'remote' to disconnect and
 366  * reconnect. */
 367 static void
 368 ovsdb_jsonrpc_session_reconnect_all(struct ovsdb_jsonrpc_remote *remote)
 369 {
 370     struct ovsdb_jsonrpc_session *s, *next;
 371
 372     LIST_FOR_EACH_SAFE (s, next, struct ovsdb_jsonrpc_session, node,
 373                         &remote->sessions) {
 374         jsonrpc_session_force_reconnect(s->js);
 375         if (!jsonrpc_session_is_alive(s->js)) {
 376             ovsdb_jsonrpc_session_close(s);
 377         }
 378     }
 379 }
 380
 381 static const char *
 382 get_db_name(const struct ovsdb_jsonrpc_session *s)
 383 {
 384     return s->remote->server->db->schema->name;
 385 }
 386
 387 static struct jsonrpc_msg *
 388 ovsdb_jsonrpc_check_db_name(const struct ovsdb_jsonrpc_session *s,
 389                             const struct jsonrpc_msg *request)
 390 {
 391     struct json_array *params;
 392     const char *want_db_name;
 393     const char *have_db_name;
 394     struct ovsdb_error *error;
 395     struct jsonrpc_msg *reply;
 396
 397     params = json_array(request->params);
 398     if (!params->n || params->elems[0]->type != JSON_STRING) {
 399         error = ovsdb_syntax_error(
 400             request->params, NULL,
 401             "%s request params must begin with <db-name>", request->method);
 402         goto error;
 403     }
 404
 405     want_db_name = params->elems[0]->u.string;
 406     have_db_name = get_db_name(s);
 407     if (strcmp(want_db_name, have_db_name)) {
 408         error = ovsdb_syntax_error(
 409             request->params, "unknown database",
 410             "%s request specifies unknown database %s",
 411             request->method, want_db_name);
 412         goto error;
 413     }
 414
 415     return NULL;
 416
 417 error:
 418     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
 419     ovsdb_error_destroy(error);
 420     return reply;
 421 }
 422
 423 static struct jsonrpc_msg *
 424 execute_transaction(struct ovsdb_jsonrpc_session *s,
 425                     struct jsonrpc_msg *request)
 426 {
 427     ovsdb_jsonrpc_trigger_create(s, request->id, request->params);
 428     request->id = NULL;
 429     request->params = NULL;
 430     jsonrpc_msg_destroy(request);
 431     return NULL;
 432 }
 433
 434 static void
 435 ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *s,
 436                                   struct jsonrpc_msg *request)
 437 {
 438     struct jsonrpc_msg *reply;
 439
 440     if (!strcmp(request->method, "transact")) {
 441         reply = ovsdb_jsonrpc_check_db_name(s, request);
 442         if (!reply) {
 443             reply = execute_transaction(s, request);
 444         }
 445     } else if (!strcmp(request->method, "monitor")) {
 446         reply = ovsdb_jsonrpc_check_db_name(s, request);
 447         if (!reply) {
 448             reply = jsonrpc_create_reply(
 449                 ovsdb_jsonrpc_monitor_create(s, request->params), request->id);
 450         }
 451     } else if (!strcmp(request->method, "monitor_cancel")) {
 452         reply = ovsdb_jsonrpc_monitor_cancel(s, json_array(request->params),
 453                                              request->id);
 454     } else if (!strcmp(request->method, "get_schema")) {
 455         reply = ovsdb_jsonrpc_check_db_name(s, request);
 456         if (!reply) {
 457             reply = jsonrpc_create_reply(
 458                 ovsdb_schema_to_json(s->remote->server->db->schema),
 459                 request->id);
 460         }
 461     } else if (!strcmp(request->method, "list_dbs")) {
 462         reply = jsonrpc_create_reply(
 463             json_array_create_1(json_string_create(get_db_name(s))),
 464             request->id);
 465     } else if (!strcmp(request->method, "echo")) {
 466         reply = jsonrpc_create_reply(json_clone(request->params), request->id);
 467     } else {
 468         reply = jsonrpc_create_error(json_string_create("unknown method"),
 469                                      request->id);
 470     }
 471
 472     if (reply) {
 473         jsonrpc_msg_destroy(request);
 474         jsonrpc_session_send(s->js, reply);
 475     }
 476 }
 477
 478 static void
 479 execute_cancel(struct ovsdb_jsonrpc_session *s, struct jsonrpc_msg *request)
 480 {
 481     if (json_array(request->params)->n == 1) {
 482         struct ovsdb_jsonrpc_trigger *t;
 483         struct json *id;
 484
 485         id = request->params->u.array.elems[0];
 486         t = ovsdb_jsonrpc_trigger_find(s, id, json_hash(id, 0));
 487         if (t) {
 488             ovsdb_jsonrpc_trigger_complete(t);
 489         }
 490     }
 491 }
 492
 493 static void
 494 ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *s,
 495                                  struct jsonrpc_msg *request)
 496 {
 497     if (!strcmp(request->method, "cancel")) {
 498         execute_cancel(s, request);
 499     }
 500     jsonrpc_msg_destroy(request);
 501 }
 502 \f
 503 /* JSON-RPC database server triggers.
 504  *
 505  * (Every transaction is treated as a trigger even if it doesn't actually have
 506  * any "wait" operations.) */
 507
 508 struct ovsdb_jsonrpc_trigger {
 509     struct ovsdb_trigger trigger;
 510     struct ovsdb_jsonrpc_session *session;
 511     struct hmap_node hmap_node; /* In session's "triggers" hmap. */
 512     struct json *id;
 513 };
 514
 515 static void
 516 ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *s,
 517                              struct json *id, struct json *params)
 518 {
 519     struct ovsdb_jsonrpc_trigger *t;
 520     size_t hash;
 521
 522     /* Check for duplicate ID. */
 523     hash = json_hash(id, 0);
 524     t = ovsdb_jsonrpc_trigger_find(s, id, hash);
 525     if (t) {
 526         struct jsonrpc_msg *msg;
 527
 528         msg = jsonrpc_create_error(json_string_create("duplicate request ID"),
 529                                    id);
 530         jsonrpc_session_send(s->js, msg);
 531         json_destroy(id);
 532         json_destroy(params);
 533         return;
 534     }
 535
 536     /* Insert into trigger table. */
 537     t = xmalloc(sizeof *t);
 538     ovsdb_trigger_init(s->remote->server->db,
 539                        &t->trigger, params, &s->completions,
 540                        time_msec());
 541     t->session = s;
 542     t->id = id;
 543     hmap_insert(&s->triggers, &t->hmap_node, hash);
 544
 545     /* Complete early if possible. */
 546     if (ovsdb_trigger_is_complete(&t->trigger)) {
 547         ovsdb_jsonrpc_trigger_complete(t);
 548     }
 549 }
 550
 551 static struct ovsdb_jsonrpc_trigger *
 552 ovsdb_jsonrpc_trigger_find(struct ovsdb_jsonrpc_session *s,
 553                            const struct json *id, size_t hash)
 554 {
 555     struct ovsdb_jsonrpc_trigger *t;
 556
 557     HMAP_FOR_EACH_WITH_HASH (t, struct ovsdb_jsonrpc_trigger, hmap_node, hash,
 558                              &s->triggers) {
 559         if (json_equal(t->id, id)) {
 560             return t;
 561         }
 562     }
 563
 564     return NULL;
 565 }
 566
 567 static void
 568 ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *t)
 569 {
 570     struct ovsdb_jsonrpc_session *s = t->session;
 571
 572     if (jsonrpc_session_is_connected(s->js)) {
 573         struct jsonrpc_msg *reply;
 574         struct json *result;
 575
 576         result = ovsdb_trigger_steal_result(&t->trigger);
 577         if (result) {
 578             reply = jsonrpc_create_reply(result, t->id);
 579         } else {
 580             reply = jsonrpc_create_error(json_string_create("canceled"),
 581                                          t->id);
 582         }
 583         jsonrpc_session_send(s->js, reply);
 584     }
 585
 586     json_destroy(t->id);
 587     ovsdb_trigger_destroy(&t->trigger);
 588     hmap_remove(&s->triggers, &t->hmap_node);
 589     free(t);
 590 }
 591
 592 static void
 593 ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *s)
 594 {
 595     struct ovsdb_jsonrpc_trigger *t, *next;
 596     HMAP_FOR_EACH_SAFE (t, next, struct ovsdb_jsonrpc_trigger, hmap_node,
 597                         &s->triggers) {
 598         ovsdb_jsonrpc_trigger_complete(t);
 599     }
 600 }
 601
 602 static void
 603 ovsdb_jsonrpc_trigger_complete_done(struct ovsdb_jsonrpc_session *s)
 604 {
 605     while (!list_is_empty(&s->completions)) {
 606         struct ovsdb_jsonrpc_trigger *t
 607             = CONTAINER_OF(s->completions.next,
 608                            struct ovsdb_jsonrpc_trigger, trigger.node);
 609         ovsdb_jsonrpc_trigger_complete(t);
 610     }
 611 }
 612 \f
 613 /* JSON-RPC database table monitors. */
 614
 615 enum ovsdb_jsonrpc_monitor_selection {
 616     OJMS_INITIAL = 1 << 0,      /* All rows when monitor is created. */
 617     OJMS_INSERT = 1 << 1,       /* New rows. */
 618     OJMS_DELETE = 1 << 2,       /* Deleted rows. */
 619     OJMS_MODIFY = 1 << 3        /* Modified rows. */
 620 };
 621
 622 /* A particular column being monitored. */
 623 struct ovsdb_jsonrpc_monitor_column {
 624     const struct ovsdb_column *column;
 625     enum ovsdb_jsonrpc_monitor_selection select;
 626 };
 627
 628 /* A particular table being monitored. */
 629 struct ovsdb_jsonrpc_monitor_table {
 630     const struct ovsdb_table *table;
 631
 632     /* This is the union (bitwise-OR) of the 'select' values in all of the
 633      * members of 'columns' below. */
 634     enum ovsdb_jsonrpc_monitor_selection select;
 635
 636     /* Columns being monitored. */
 637     struct ovsdb_jsonrpc_monitor_column *columns;
 638     size_t n_columns;
 639 };
 640
 641 /* A collection of tables being monitored. */
 642 struct ovsdb_jsonrpc_monitor {
 643     struct ovsdb_replica replica;
 644     struct ovsdb_jsonrpc_session *session;
 645     struct hmap_node node;      /* In ovsdb_jsonrpc_session's "monitors". */
 646
 647     struct json *monitor_id;
 648     struct shash tables;     /* Holds "struct ovsdb_jsonrpc_monitor_table"s. */
 649 };
 650
 651 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class;
 652
 653 struct ovsdb_jsonrpc_monitor *ovsdb_jsonrpc_monitor_find(
 654     struct ovsdb_jsonrpc_session *, const struct json *monitor_id);
 655 static void ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *);
 656 static struct json *ovsdb_jsonrpc_monitor_get_initial(
 657     const struct ovsdb_jsonrpc_monitor *);
 658
 659 static bool
 660 parse_bool(struct ovsdb_parser *parser, const char *name, bool default_value)
 661 {
 662     const struct json *json;
 663
 664     json = ovsdb_parser_member(parser, name, OP_BOOLEAN | OP_OPTIONAL);
 665     return json ? json_boolean(json) : default_value;
 666 }
 667
 668 struct ovsdb_jsonrpc_monitor *
 669 ovsdb_jsonrpc_monitor_find(struct ovsdb_jsonrpc_session *s,
 670                            const struct json *monitor_id)
 671 {
 672     struct ovsdb_jsonrpc_monitor *m;
 673
 674     HMAP_FOR_EACH_WITH_HASH (m, struct ovsdb_jsonrpc_monitor, node,
 675                              json_hash(monitor_id, 0), &s->monitors) {
 676         if (json_equal(m->monitor_id, monitor_id)) {
 677             return m;
 678         }
 679     }
 680
 681     return NULL;
 682 }
 683
 684 static void
 685 ovsdb_jsonrpc_add_monitor_column(struct ovsdb_jsonrpc_monitor_table *mt,
 686                                  const struct ovsdb_column *column,
 687                                  enum ovsdb_jsonrpc_monitor_selection select,
 688                                  size_t *allocated_columns)
 689 {
 690     struct ovsdb_jsonrpc_monitor_column *c;
 691
 692     if (mt->n_columns >= *allocated_columns) {
 693         mt->columns = x2nrealloc(mt->columns, allocated_columns,
 694                                  sizeof *mt->columns);
 695     }
 696
 697     c = &mt->columns[mt->n_columns++];
 698     c->column = column;
 699     c->select = select;
 700 }
 701
 702 static int
 703 compare_ovsdb_jsonrpc_monitor_column(const void *a_, const void *b_)
 704 {
 705     const struct ovsdb_jsonrpc_monitor_column *a = a_;
 706     const struct ovsdb_jsonrpc_monitor_column *b = b_;
 707
 708     return a->column < b->column ? -1 : a->column > b->column;
 709 }
 710
 711 static struct ovsdb_error * WARN_UNUSED_RESULT
 712 ovsdb_jsonrpc_parse_monitor_request(struct ovsdb_jsonrpc_monitor_table *mt,
 713                                     const struct json *monitor_request,
 714                                     size_t *allocated_columns)
 715 {
 716     const struct ovsdb_table_schema *ts = mt->table->schema;
 717     enum ovsdb_jsonrpc_monitor_selection select;
 718     const struct json *columns, *select_json;
 719     struct ovsdb_parser parser;
 720     struct ovsdb_error *error;
 721
 722     ovsdb_parser_init(&parser, monitor_request, "table %s", ts->name);
 723     columns = ovsdb_parser_member(&parser, "columns", OP_ARRAY | OP_OPTIONAL);
 724     select_json = ovsdb_parser_member(&parser, "select",
 725                                       OP_OBJECT | OP_OPTIONAL);
 726     error = ovsdb_parser_finish(&parser);
 727     if (error) {
 728         return error;
 729     }
 730
 731     if (select_json) {
 732         select = 0;
 733         ovsdb_parser_init(&parser, select_json, "table %s select", ts->name);
 734         if (parse_bool(&parser, "initial", true)) {
 735             select |= OJMS_INITIAL;
 736         }
 737         if (parse_bool(&parser, "insert", true)) {
 738             select |= OJMS_INSERT;
 739         }
 740         if (parse_bool(&parser, "delete", true)) {
 741             select |= OJMS_DELETE;
 742         }
 743         if (parse_bool(&parser, "modify", true)) {
 744             select |= OJMS_MODIFY;
 745         }
 746         error = ovsdb_parser_finish(&parser);
 747         if (error) {
 748             return error;
 749         }
 750     } else {
 751         select = OJMS_INITIAL | OJMS_INSERT | OJMS_DELETE | OJMS_MODIFY;
 752     }
 753     mt->select |= select;
 754
 755     if (columns) {
 756         size_t i;
 757
 758         if (columns->type != JSON_ARRAY) {
 759             return ovsdb_syntax_error(columns, NULL,
 760                                       "array of column names expected");
 761         }
 762
 763         for (i = 0; i < columns->u.array.n; i++) {
 764             const struct ovsdb_column *column;
 765             const char *s;
 766
 767             if (columns->u.array.elems[i]->type != JSON_STRING) {
 768                 return ovsdb_syntax_error(columns, NULL,
 769                                           "array of column names expected");
 770             }
 771
 772             s = columns->u.array.elems[i]->u.string;
 773             column = shash_find_data(&mt->table->schema->columns, s);
 774             if (!column) {
 775                 return ovsdb_syntax_error(columns, NULL, "%s is not a valid "
 776                                           "column name", s);
 777             }
 778             ovsdb_jsonrpc_add_monitor_column(mt, column, select,
 779                                              allocated_columns);
 780         }
 781     } else {
 782         struct shash_node *node;
 783
 784         SHASH_FOR_EACH (node, &ts->columns) {
 785             const struct ovsdb_column *column = node->data;
 786             if (column->index != OVSDB_COL_UUID) {
 787                 ovsdb_jsonrpc_add_monitor_column(mt, column, select,
 788                                                  allocated_columns);
 789             }
 790         }
 791     }
 792
 793     return NULL;
 794 }
 795
 796 static struct json *
 797 ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s,
 798                              struct json *params)
 799 {
 800     struct ovsdb_jsonrpc_monitor *m = NULL;
 801     struct json *monitor_id, *monitor_requests;
 802     struct ovsdb_error *error = NULL;
 803     struct shash_node *node;
 804     struct json *json;
 805
 806     if (json_array(params)->n != 3) {
 807         error = ovsdb_syntax_error(params, NULL, "invalid parameters");
 808         goto error;
 809     }
 810     monitor_id = params->u.array.elems[1];
 811     monitor_requests = params->u.array.elems[2];
 812     if (monitor_requests->type != JSON_OBJECT) {
 813         error = ovsdb_syntax_error(monitor_requests, NULL,
 814                                    "monitor-requests must be object");
 815         goto error;
 816     }
 817
 818     if (ovsdb_jsonrpc_monitor_find(s, monitor_id)) {
 819         error = ovsdb_syntax_error(monitor_id, NULL, "duplicate monitor ID");
 820         goto error;
 821     }
 822
 823     m = xzalloc(sizeof *m);
 824     ovsdb_replica_init(&m->replica, &ovsdb_jsonrpc_replica_class);
 825     ovsdb_add_replica(s->remote->server->db, &m->replica);
 826     m->session = s;
 827     hmap_insert(&s->monitors, &m->node, json_hash(monitor_id, 0));
 828     m->monitor_id = json_clone(monitor_id);
 829     shash_init(&m->tables);
 830
 831     SHASH_FOR_EACH (node, json_object(monitor_requests)) {
 832         const struct ovsdb_table *table;
 833         struct ovsdb_jsonrpc_monitor_table *mt;
 834         size_t allocated_columns;
 835         const struct json *mr_value;
 836         size_t i;
 837
 838         table = ovsdb_get_table(s->remote->server->db, node->name);
 839         if (!table) {
 840             error = ovsdb_syntax_error(NULL, NULL,
 841                                        "no table named %s", node->name);
 842             goto error;
 843         }
 844
 845         mt = xzalloc(sizeof *mt);
 846         mt->table = table;
 847         shash_add(&m->tables, table->schema->name, mt);
 848
 849         /* Parse columns. */
 850         mr_value = node->data;
 851         allocated_columns = 0;
 852         if (mr_value->type == JSON_ARRAY) {
 853             const struct json_array *array = &mr_value->u.array;
 854
 855             for (i = 0; i < array->n; i++) {
 856                 error = ovsdb_jsonrpc_parse_monitor_request(
 857                     mt, array->elems[i], &allocated_columns);
 858                 if (error) {
 859                     goto error;
 860                 }
 861             }
 862         } else {
 863             error = ovsdb_jsonrpc_parse_monitor_request(
 864                 mt, mr_value, &allocated_columns);
 865             if (error) {
 866                 goto error;
 867             }
 868         }
 869
 870         /* Check for duplicate columns. */
 871         qsort(mt->columns, mt->n_columns, sizeof *mt->columns,
 872               compare_ovsdb_jsonrpc_monitor_column);
 873         for (i = 1; i < mt->n_columns; i++) {
 874             if (mt->columns[i].column == mt->columns[i - 1].column) {
 875                 error = ovsdb_syntax_error(mr_value, NULL, "column %s "
 876                                            "mentioned more than once",
 877                                            mt->columns[i].column->name);
 878                 goto error;
 879             }
 880         }
 881     }
 882
 883     return ovsdb_jsonrpc_monitor_get_initial(m);
 884
 885 error:
 886     if (m) {
 887         ovsdb_remove_replica(s->remote->server->db, &m->replica);
 888     }
 889
 890     json = ovsdb_error_to_json(error);
 891     ovsdb_error_destroy(error);
 892     return json;
 893 }
 894
 895 static struct jsonrpc_msg *
 896 ovsdb_jsonrpc_monitor_cancel(struct ovsdb_jsonrpc_session *s,
 897                              struct json_array *params,
 898                              const struct json *request_id)
 899 {
 900     if (params->n != 1) {
 901         return jsonrpc_create_error(json_string_create("invalid parameters"),
 902                                     request_id);
 903     } else {
 904         struct ovsdb_jsonrpc_monitor *m;
 905
 906         m = ovsdb_jsonrpc_monitor_find(s, params->elems[0]);
 907         if (!m) {
 908             return jsonrpc_create_error(json_string_create("unknown monitor"),
 909                                         request_id);
 910         } else {
 911             ovsdb_remove_replica(s->remote->server->db, &m->replica);
 912             return jsonrpc_create_reply(json_object_create(), request_id);
 913         }
 914     }
 915 }
 916
 917 static void
 918 ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *s)
 919 {
 920     struct ovsdb_jsonrpc_monitor *m, *next;
 921
 922     HMAP_FOR_EACH_SAFE (m, next,
 923                         struct ovsdb_jsonrpc_monitor, node, &s->monitors) {
 924         ovsdb_remove_replica(s->remote->server->db, &m->replica);
 925     }
 926 }
 927
 928 static struct ovsdb_jsonrpc_monitor *
 929 ovsdb_jsonrpc_monitor_cast(struct ovsdb_replica *replica)
 930 {
 931     assert(replica->class == &ovsdb_jsonrpc_replica_class);
 932     return CONTAINER_OF(replica, struct ovsdb_jsonrpc_monitor, replica);
 933 }
 934
 935 struct ovsdb_jsonrpc_monitor_aux {
 936     bool initial;               /* Sending initial contents of table? */
 937     const struct ovsdb_jsonrpc_monitor *monitor;
 938     struct json *json;          /* JSON for the whole transaction. */
 939
 940     /* Current table.  */
 941     struct ovsdb_jsonrpc_monitor_table *mt;
 942     struct json *table_json;    /* JSON for table's transaction. */
 943 };
 944
 945 static bool
 946 ovsdb_jsonrpc_monitor_change_cb(const struct ovsdb_row *old,
 947                                 const struct ovsdb_row *new,
 948                                 const unsigned long int *changed,
 949                                 void *aux_)
 950 {
 951     struct ovsdb_jsonrpc_monitor_aux *aux = aux_;
 952     const struct ovsdb_jsonrpc_monitor *m = aux->monitor;
 953     struct ovsdb_table *table = new ? new->table : old->table;
 954     enum ovsdb_jsonrpc_monitor_selection type;
 955     struct json *old_json, *new_json;
 956     struct json *row_json;
 957     char uuid[UUID_LEN + 1];
 958     int n_changed;
 959     size_t i;
 960
 961     if (!aux->mt || table != aux->mt->table) {
 962         aux->mt = shash_find_data(&m->tables, table->schema->name);
 963         aux->table_json = NULL;
 964         if (!aux->mt) {
 965             /* We don't care about rows in this table at all.  Tell the caller
 966              * to skip it.  */
 967             return false;
 968         }
 969     }
 970
 971     type = (aux->initial ? OJMS_INITIAL
 972             : !old ? OJMS_INSERT
 973             : !new ? OJMS_DELETE
 974             : OJMS_MODIFY);
 975     if (!(aux->mt->select & type)) {
 976         /* We don't care about this type of change (but do want to be called
 977          * back for changes to other rows in the same table). */
 978         return true;
 979     }
 980
 981     old_json = new_json = NULL;
 982     n_changed = 0;
 983     for (i = 0; i < aux->mt->n_columns; i++) {
 984         const struct ovsdb_jsonrpc_monitor_column *c = &aux->mt->columns[i];
 985         const struct ovsdb_column *column = c->column;
 986         unsigned int idx = c->column->index;
 987         bool column_changed = false;
 988
 989         if (!(type & c->select)) {
 990             /* We don't care about this type of change for this particular
 991              * column (but we will care about it for some other column). */
 992             continue;
 993         }
 994
 995         if (type == OJMS_MODIFY) {
 996             column_changed = bitmap_is_set(changed, idx);
 997             n_changed += column_changed;
 998         }
 999         if (column_changed || type == OJMS_DELETE) {
1000             if (!old_json) {
1001                 old_json = json_object_create();
1002             }
1003             json_object_put(old_json, column->name,
1004                             ovsdb_datum_to_json(&old->fields[idx],
1005                                                 &column->type));
1006         }
1007         if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
1008             if (!new_json) {
1009                 new_json = json_object_create();
1010             }
1011             json_object_put(new_json, column->name,
1012                             ovsdb_datum_to_json(&new->fields[idx],
1013                                                 &column->type));
1014         }
1015     }
1016     if ((type == OJMS_MODIFY && !n_changed) || (!old_json && !new_json)) {
1017         /* No reportable changes. */
1018         json_destroy(old_json);
1019         json_destroy(new_json);
1020         return true;
1021     }
1022
1023     /* Create JSON object for transaction overall. */
1024     if (!aux->json) {
1025         aux->json = json_object_create();
1026     }
1027
1028     /* Create JSON object for transaction on this table. */
1029     if (!aux->table_json) {
1030         aux->table_json = json_object_create();
1031         json_object_put(aux->json, aux->mt->table->schema->name,
1032                         aux->table_json);
1033     }
1034
1035     /* Create JSON object for transaction on this row. */
1036     row_json = json_object_create();
1037     if (old_json) {
1038         json_object_put(row_json, "old", old_json);
1039     }
1040     if (new_json) {
1041         json_object_put(row_json, "new", new_json);
1042     }
1043
1044     /* Add JSON row to JSON table. */
1045     snprintf(uuid, sizeof uuid,
1046              UUID_FMT, UUID_ARGS(ovsdb_row_get_uuid(new ? new : old)));
1047     json_object_put(aux->table_json, uuid, row_json);
1048
1049     return true;
1050 }
1051
1052 static void
1053 ovsdb_jsonrpc_monitor_init_aux(struct ovsdb_jsonrpc_monitor_aux *aux,
1054                                const struct ovsdb_jsonrpc_monitor *m,
1055                                bool initial)
1056 {
1057     aux->initial = initial;
1058     aux->monitor = m;
1059     aux->json = NULL;
1060     aux->mt = NULL;
1061     aux->table_json = NULL;
1062 }
1063
1064 static struct ovsdb_error *
1065 ovsdb_jsonrpc_monitor_commit(struct ovsdb_replica *replica,
1066                              const struct ovsdb_txn *txn,
1067                              bool durable OVS_UNUSED)
1068 {
1069     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1070     struct ovsdb_jsonrpc_monitor_aux aux;
1071
1072     ovsdb_jsonrpc_monitor_init_aux(&aux, m, false);
1073     ovsdb_txn_for_each_change(txn, ovsdb_jsonrpc_monitor_change_cb, &aux);
1074     if (aux.json) {
1075         struct jsonrpc_msg *msg;
1076         struct json *params;
1077
1078         params = json_array_create_2(json_clone(aux.monitor->monitor_id),
1079                                      aux.json);
1080         msg = jsonrpc_create_notify("update", params);
1081         jsonrpc_session_send(aux.monitor->session->js, msg);
1082     }
1083
1084     return NULL;
1085 }
1086
1087 static struct json *
1088 ovsdb_jsonrpc_monitor_get_initial(const struct ovsdb_jsonrpc_monitor *m)
1089 {
1090     struct ovsdb_jsonrpc_monitor_aux aux;
1091     struct shash_node *node;
1092
1093     ovsdb_jsonrpc_monitor_init_aux(&aux, m, true);
1094     SHASH_FOR_EACH (node, &m->tables) {
1095         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1096
1097         if (mt->select & OJMS_INITIAL) {
1098             struct ovsdb_row *row;
1099
1100             HMAP_FOR_EACH (row, struct ovsdb_row, hmap_node,
1101                            &mt->table->rows) {
1102                 ovsdb_jsonrpc_monitor_change_cb(NULL, row, NULL, &aux);
1103             }
1104         }
1105     }
1106     return aux.json ? aux.json : json_object_create();
1107 }
1108
1109 static void
1110 ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *replica)
1111 {
1112     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1113     struct shash_node *node;
1114
1115     json_destroy(m->monitor_id);
1116     SHASH_FOR_EACH (node, &m->tables) {
1117         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1118         free(mt->columns);
1119         free(mt);
1120     }
1121     shash_destroy(&m->tables);
1122     hmap_remove(&m->session->monitors, &m->node);
1123     free(m);
1124 }
1125
1126 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class = {
1127     ovsdb_jsonrpc_monitor_commit,
1128     ovsdb_jsonrpc_monitor_destroy
1129 };