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, node, &remote->sessions) {
 327         int error = ovsdb_jsonrpc_session_run(s);
 328         if (error) {
 329             ovsdb_jsonrpc_session_close(s);
 330         }
 331     }
 332 }
 333
 334 static void
 335 ovsdb_jsonrpc_session_wait(struct ovsdb_jsonrpc_session *s)
 336 {
 337     jsonrpc_session_wait(s->js);
 338     if (!jsonrpc_session_get_backlog(s->js)) {
 339         jsonrpc_session_recv_wait(s->js);
 340     }
 341 }
 342
 343 static void
 344 ovsdb_jsonrpc_session_wait_all(struct ovsdb_jsonrpc_remote *remote)
 345 {
 346     struct ovsdb_jsonrpc_session *s;
 347
 348     LIST_FOR_EACH (s, node, &remote->sessions) {
 349         ovsdb_jsonrpc_session_wait(s);
 350     }
 351 }
 352
 353 static void
 354 ovsdb_jsonrpc_session_close_all(struct ovsdb_jsonrpc_remote *remote)
 355 {
 356     struct ovsdb_jsonrpc_session *s, *next;
 357
 358     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
 359         ovsdb_jsonrpc_session_close(s);
 360     }
 361 }
 362
 363 /* Forces all of the JSON-RPC sessions managed by 'remote' to disconnect and
 364  * reconnect. */
 365 static void
 366 ovsdb_jsonrpc_session_reconnect_all(struct ovsdb_jsonrpc_remote *remote)
 367 {
 368     struct ovsdb_jsonrpc_session *s, *next;
 369
 370     LIST_FOR_EACH_SAFE (s, next, node, &remote->sessions) {
 371         jsonrpc_session_force_reconnect(s->js);
 372         if (!jsonrpc_session_is_alive(s->js)) {
 373             ovsdb_jsonrpc_session_close(s);
 374         }
 375     }
 376 }
 377
 378 static const char *
 379 get_db_name(const struct ovsdb_jsonrpc_session *s)
 380 {
 381     return s->remote->server->db->schema->name;
 382 }
 383
 384 static struct jsonrpc_msg *
 385 ovsdb_jsonrpc_check_db_name(const struct ovsdb_jsonrpc_session *s,
 386                             const struct jsonrpc_msg *request)
 387 {
 388     struct json_array *params;
 389     const char *want_db_name;
 390     const char *have_db_name;
 391     struct ovsdb_error *error;
 392     struct jsonrpc_msg *reply;
 393
 394     params = json_array(request->params);
 395     if (!params->n || params->elems[0]->type != JSON_STRING) {
 396         error = ovsdb_syntax_error(
 397             request->params, NULL,
 398             "%s request params must begin with <db-name>", request->method);
 399         goto error;
 400     }
 401
 402     want_db_name = params->elems[0]->u.string;
 403     have_db_name = get_db_name(s);
 404     if (strcmp(want_db_name, have_db_name)) {
 405         error = ovsdb_syntax_error(
 406             request->params, "unknown database",
 407             "%s request specifies unknown database %s",
 408             request->method, want_db_name);
 409         goto error;
 410     }
 411
 412     return NULL;
 413
 414 error:
 415     reply = jsonrpc_create_reply(ovsdb_error_to_json(error), request->id);
 416     ovsdb_error_destroy(error);
 417     return reply;
 418 }
 419
 420 static struct jsonrpc_msg *
 421 execute_transaction(struct ovsdb_jsonrpc_session *s,
 422                     struct jsonrpc_msg *request)
 423 {
 424     ovsdb_jsonrpc_trigger_create(s, request->id, request->params);
 425     request->id = NULL;
 426     request->params = NULL;
 427     jsonrpc_msg_destroy(request);
 428     return NULL;
 429 }
 430
 431 static void
 432 ovsdb_jsonrpc_session_got_request(struct ovsdb_jsonrpc_session *s,
 433                                   struct jsonrpc_msg *request)
 434 {
 435     struct jsonrpc_msg *reply;
 436
 437     if (!strcmp(request->method, "transact")) {
 438         reply = ovsdb_jsonrpc_check_db_name(s, request);
 439         if (!reply) {
 440             reply = execute_transaction(s, request);
 441         }
 442     } else if (!strcmp(request->method, "monitor")) {
 443         reply = ovsdb_jsonrpc_check_db_name(s, request);
 444         if (!reply) {
 445             reply = jsonrpc_create_reply(
 446                 ovsdb_jsonrpc_monitor_create(s, request->params), request->id);
 447         }
 448     } else if (!strcmp(request->method, "monitor_cancel")) {
 449         reply = ovsdb_jsonrpc_monitor_cancel(s, json_array(request->params),
 450                                              request->id);
 451     } else if (!strcmp(request->method, "get_schema")) {
 452         reply = ovsdb_jsonrpc_check_db_name(s, request);
 453         if (!reply) {
 454             reply = jsonrpc_create_reply(
 455                 ovsdb_schema_to_json(s->remote->server->db->schema),
 456                 request->id);
 457         }
 458     } else if (!strcmp(request->method, "list_dbs")) {
 459         reply = jsonrpc_create_reply(
 460             json_array_create_1(json_string_create(get_db_name(s))),
 461             request->id);
 462     } else if (!strcmp(request->method, "echo")) {
 463         reply = jsonrpc_create_reply(json_clone(request->params), request->id);
 464     } else {
 465         reply = jsonrpc_create_error(json_string_create("unknown method"),
 466                                      request->id);
 467     }
 468
 469     if (reply) {
 470         jsonrpc_msg_destroy(request);
 471         jsonrpc_session_send(s->js, reply);
 472     }
 473 }
 474
 475 static void
 476 execute_cancel(struct ovsdb_jsonrpc_session *s, struct jsonrpc_msg *request)
 477 {
 478     if (json_array(request->params)->n == 1) {
 479         struct ovsdb_jsonrpc_trigger *t;
 480         struct json *id;
 481
 482         id = request->params->u.array.elems[0];
 483         t = ovsdb_jsonrpc_trigger_find(s, id, json_hash(id, 0));
 484         if (t) {
 485             ovsdb_jsonrpc_trigger_complete(t);
 486         }
 487     }
 488 }
 489
 490 static void
 491 ovsdb_jsonrpc_session_got_notify(struct ovsdb_jsonrpc_session *s,
 492                                  struct jsonrpc_msg *request)
 493 {
 494     if (!strcmp(request->method, "cancel")) {
 495         execute_cancel(s, request);
 496     }
 497     jsonrpc_msg_destroy(request);
 498 }
 499 \f
 500 /* JSON-RPC database server triggers.
 501  *
 502  * (Every transaction is treated as a trigger even if it doesn't actually have
 503  * any "wait" operations.) */
 504
 505 struct ovsdb_jsonrpc_trigger {
 506     struct ovsdb_trigger trigger;
 507     struct ovsdb_jsonrpc_session *session;
 508     struct hmap_node hmap_node; /* In session's "triggers" hmap. */
 509     struct json *id;
 510 };
 511
 512 static void
 513 ovsdb_jsonrpc_trigger_create(struct ovsdb_jsonrpc_session *s,
 514                              struct json *id, struct json *params)
 515 {
 516     struct ovsdb_jsonrpc_trigger *t;
 517     size_t hash;
 518
 519     /* Check for duplicate ID. */
 520     hash = json_hash(id, 0);
 521     t = ovsdb_jsonrpc_trigger_find(s, id, hash);
 522     if (t) {
 523         struct jsonrpc_msg *msg;
 524
 525         msg = jsonrpc_create_error(json_string_create("duplicate request ID"),
 526                                    id);
 527         jsonrpc_session_send(s->js, msg);
 528         json_destroy(id);
 529         json_destroy(params);
 530         return;
 531     }
 532
 533     /* Insert into trigger table. */
 534     t = xmalloc(sizeof *t);
 535     ovsdb_trigger_init(s->remote->server->db,
 536                        &t->trigger, params, &s->completions,
 537                        time_msec());
 538     t->session = s;
 539     t->id = id;
 540     hmap_insert(&s->triggers, &t->hmap_node, hash);
 541
 542     /* Complete early if possible. */
 543     if (ovsdb_trigger_is_complete(&t->trigger)) {
 544         ovsdb_jsonrpc_trigger_complete(t);
 545     }
 546 }
 547
 548 static struct ovsdb_jsonrpc_trigger *
 549 ovsdb_jsonrpc_trigger_find(struct ovsdb_jsonrpc_session *s,
 550                            const struct json *id, size_t hash)
 551 {
 552     struct ovsdb_jsonrpc_trigger *t;
 553
 554     HMAP_FOR_EACH_WITH_HASH (t, hmap_node, hash, &s->triggers) {
 555         if (json_equal(t->id, id)) {
 556             return t;
 557         }
 558     }
 559
 560     return NULL;
 561 }
 562
 563 static void
 564 ovsdb_jsonrpc_trigger_complete(struct ovsdb_jsonrpc_trigger *t)
 565 {
 566     struct ovsdb_jsonrpc_session *s = t->session;
 567
 568     if (jsonrpc_session_is_connected(s->js)) {
 569         struct jsonrpc_msg *reply;
 570         struct json *result;
 571
 572         result = ovsdb_trigger_steal_result(&t->trigger);
 573         if (result) {
 574             reply = jsonrpc_create_reply(result, t->id);
 575         } else {
 576             reply = jsonrpc_create_error(json_string_create("canceled"),
 577                                          t->id);
 578         }
 579         jsonrpc_session_send(s->js, reply);
 580     }
 581
 582     json_destroy(t->id);
 583     ovsdb_trigger_destroy(&t->trigger);
 584     hmap_remove(&s->triggers, &t->hmap_node);
 585     free(t);
 586 }
 587
 588 static void
 589 ovsdb_jsonrpc_trigger_complete_all(struct ovsdb_jsonrpc_session *s)
 590 {
 591     struct ovsdb_jsonrpc_trigger *t, *next;
 592     HMAP_FOR_EACH_SAFE (t, next, hmap_node, &s->triggers) {
 593         ovsdb_jsonrpc_trigger_complete(t);
 594     }
 595 }
 596
 597 static void
 598 ovsdb_jsonrpc_trigger_complete_done(struct ovsdb_jsonrpc_session *s)
 599 {
 600     while (!list_is_empty(&s->completions)) {
 601         struct ovsdb_jsonrpc_trigger *t
 602             = CONTAINER_OF(s->completions.next,
 603                            struct ovsdb_jsonrpc_trigger, trigger.node);
 604         ovsdb_jsonrpc_trigger_complete(t);
 605     }
 606 }
 607 \f
 608 /* JSON-RPC database table monitors. */
 609
 610 enum ovsdb_jsonrpc_monitor_selection {
 611     OJMS_INITIAL = 1 << 0,      /* All rows when monitor is created. */
 612     OJMS_INSERT = 1 << 1,       /* New rows. */
 613     OJMS_DELETE = 1 << 2,       /* Deleted rows. */
 614     OJMS_MODIFY = 1 << 3        /* Modified rows. */
 615 };
 616
 617 /* A particular column being monitored. */
 618 struct ovsdb_jsonrpc_monitor_column {
 619     const struct ovsdb_column *column;
 620     enum ovsdb_jsonrpc_monitor_selection select;
 621 };
 622
 623 /* A particular table being monitored. */
 624 struct ovsdb_jsonrpc_monitor_table {
 625     const struct ovsdb_table *table;
 626
 627     /* This is the union (bitwise-OR) of the 'select' values in all of the
 628      * members of 'columns' below. */
 629     enum ovsdb_jsonrpc_monitor_selection select;
 630
 631     /* Columns being monitored. */
 632     struct ovsdb_jsonrpc_monitor_column *columns;
 633     size_t n_columns;
 634 };
 635
 636 /* A collection of tables being monitored. */
 637 struct ovsdb_jsonrpc_monitor {
 638     struct ovsdb_replica replica;
 639     struct ovsdb_jsonrpc_session *session;
 640     struct hmap_node node;      /* In ovsdb_jsonrpc_session's "monitors". */
 641
 642     struct json *monitor_id;
 643     struct shash tables;     /* Holds "struct ovsdb_jsonrpc_monitor_table"s. */
 644 };
 645
 646 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class;
 647
 648 struct ovsdb_jsonrpc_monitor *ovsdb_jsonrpc_monitor_find(
 649     struct ovsdb_jsonrpc_session *, const struct json *monitor_id);
 650 static void ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *);
 651 static struct json *ovsdb_jsonrpc_monitor_get_initial(
 652     const struct ovsdb_jsonrpc_monitor *);
 653
 654 static bool
 655 parse_bool(struct ovsdb_parser *parser, const char *name, bool default_value)
 656 {
 657     const struct json *json;
 658
 659     json = ovsdb_parser_member(parser, name, OP_BOOLEAN | OP_OPTIONAL);
 660     return json ? json_boolean(json) : default_value;
 661 }
 662
 663 struct ovsdb_jsonrpc_monitor *
 664 ovsdb_jsonrpc_monitor_find(struct ovsdb_jsonrpc_session *s,
 665                            const struct json *monitor_id)
 666 {
 667     struct ovsdb_jsonrpc_monitor *m;
 668
 669     HMAP_FOR_EACH_WITH_HASH (m, node, json_hash(monitor_id, 0), &s->monitors) {
 670         if (json_equal(m->monitor_id, monitor_id)) {
 671             return m;
 672         }
 673     }
 674
 675     return NULL;
 676 }
 677
 678 static void
 679 ovsdb_jsonrpc_add_monitor_column(struct ovsdb_jsonrpc_monitor_table *mt,
 680                                  const struct ovsdb_column *column,
 681                                  enum ovsdb_jsonrpc_monitor_selection select,
 682                                  size_t *allocated_columns)
 683 {
 684     struct ovsdb_jsonrpc_monitor_column *c;
 685
 686     if (mt->n_columns >= *allocated_columns) {
 687         mt->columns = x2nrealloc(mt->columns, allocated_columns,
 688                                  sizeof *mt->columns);
 689     }
 690
 691     c = &mt->columns[mt->n_columns++];
 692     c->column = column;
 693     c->select = select;
 694 }
 695
 696 static int
 697 compare_ovsdb_jsonrpc_monitor_column(const void *a_, const void *b_)
 698 {
 699     const struct ovsdb_jsonrpc_monitor_column *a = a_;
 700     const struct ovsdb_jsonrpc_monitor_column *b = b_;
 701
 702     return a->column < b->column ? -1 : a->column > b->column;
 703 }
 704
 705 static struct ovsdb_error * WARN_UNUSED_RESULT
 706 ovsdb_jsonrpc_parse_monitor_request(struct ovsdb_jsonrpc_monitor_table *mt,
 707                                     const struct json *monitor_request,
 708                                     size_t *allocated_columns)
 709 {
 710     const struct ovsdb_table_schema *ts = mt->table->schema;
 711     enum ovsdb_jsonrpc_monitor_selection select;
 712     const struct json *columns, *select_json;
 713     struct ovsdb_parser parser;
 714     struct ovsdb_error *error;
 715
 716     ovsdb_parser_init(&parser, monitor_request, "table %s", ts->name);
 717     columns = ovsdb_parser_member(&parser, "columns", OP_ARRAY | OP_OPTIONAL);
 718     select_json = ovsdb_parser_member(&parser, "select",
 719                                       OP_OBJECT | OP_OPTIONAL);
 720     error = ovsdb_parser_finish(&parser);
 721     if (error) {
 722         return error;
 723     }
 724
 725     if (select_json) {
 726         select = 0;
 727         ovsdb_parser_init(&parser, select_json, "table %s select", ts->name);
 728         if (parse_bool(&parser, "initial", true)) {
 729             select |= OJMS_INITIAL;
 730         }
 731         if (parse_bool(&parser, "insert", true)) {
 732             select |= OJMS_INSERT;
 733         }
 734         if (parse_bool(&parser, "delete", true)) {
 735             select |= OJMS_DELETE;
 736         }
 737         if (parse_bool(&parser, "modify", true)) {
 738             select |= OJMS_MODIFY;
 739         }
 740         error = ovsdb_parser_finish(&parser);
 741         if (error) {
 742             return error;
 743         }
 744     } else {
 745         select = OJMS_INITIAL | OJMS_INSERT | OJMS_DELETE | OJMS_MODIFY;
 746     }
 747     mt->select |= select;
 748
 749     if (columns) {
 750         size_t i;
 751
 752         if (columns->type != JSON_ARRAY) {
 753             return ovsdb_syntax_error(columns, NULL,
 754                                       "array of column names expected");
 755         }
 756
 757         for (i = 0; i < columns->u.array.n; i++) {
 758             const struct ovsdb_column *column;
 759             const char *s;
 760
 761             if (columns->u.array.elems[i]->type != JSON_STRING) {
 762                 return ovsdb_syntax_error(columns, NULL,
 763                                           "array of column names expected");
 764             }
 765
 766             s = columns->u.array.elems[i]->u.string;
 767             column = shash_find_data(&mt->table->schema->columns, s);
 768             if (!column) {
 769                 return ovsdb_syntax_error(columns, NULL, "%s is not a valid "
 770                                           "column name", s);
 771             }
 772             ovsdb_jsonrpc_add_monitor_column(mt, column, select,
 773                                              allocated_columns);
 774         }
 775     } else {
 776         struct shash_node *node;
 777
 778         SHASH_FOR_EACH (node, &ts->columns) {
 779             const struct ovsdb_column *column = node->data;
 780             if (column->index != OVSDB_COL_UUID) {
 781                 ovsdb_jsonrpc_add_monitor_column(mt, column, select,
 782                                                  allocated_columns);
 783             }
 784         }
 785     }
 786
 787     return NULL;
 788 }
 789
 790 static struct json *
 791 ovsdb_jsonrpc_monitor_create(struct ovsdb_jsonrpc_session *s,
 792                              struct json *params)
 793 {
 794     struct ovsdb_jsonrpc_monitor *m = NULL;
 795     struct json *monitor_id, *monitor_requests;
 796     struct ovsdb_error *error = NULL;
 797     struct shash_node *node;
 798     struct json *json;
 799
 800     if (json_array(params)->n != 3) {
 801         error = ovsdb_syntax_error(params, NULL, "invalid parameters");
 802         goto error;
 803     }
 804     monitor_id = params->u.array.elems[1];
 805     monitor_requests = params->u.array.elems[2];
 806     if (monitor_requests->type != JSON_OBJECT) {
 807         error = ovsdb_syntax_error(monitor_requests, NULL,
 808                                    "monitor-requests must be object");
 809         goto error;
 810     }
 811
 812     if (ovsdb_jsonrpc_monitor_find(s, monitor_id)) {
 813         error = ovsdb_syntax_error(monitor_id, NULL, "duplicate monitor ID");
 814         goto error;
 815     }
 816
 817     m = xzalloc(sizeof *m);
 818     ovsdb_replica_init(&m->replica, &ovsdb_jsonrpc_replica_class);
 819     ovsdb_add_replica(s->remote->server->db, &m->replica);
 820     m->session = s;
 821     hmap_insert(&s->monitors, &m->node, json_hash(monitor_id, 0));
 822     m->monitor_id = json_clone(monitor_id);
 823     shash_init(&m->tables);
 824
 825     SHASH_FOR_EACH (node, json_object(monitor_requests)) {
 826         const struct ovsdb_table *table;
 827         struct ovsdb_jsonrpc_monitor_table *mt;
 828         size_t allocated_columns;
 829         const struct json *mr_value;
 830         size_t i;
 831
 832         table = ovsdb_get_table(s->remote->server->db, node->name);
 833         if (!table) {
 834             error = ovsdb_syntax_error(NULL, NULL,
 835                                        "no table named %s", node->name);
 836             goto error;
 837         }
 838
 839         mt = xzalloc(sizeof *mt);
 840         mt->table = table;
 841         shash_add(&m->tables, table->schema->name, mt);
 842
 843         /* Parse columns. */
 844         mr_value = node->data;
 845         allocated_columns = 0;
 846         if (mr_value->type == JSON_ARRAY) {
 847             const struct json_array *array = &mr_value->u.array;
 848
 849             for (i = 0; i < array->n; i++) {
 850                 error = ovsdb_jsonrpc_parse_monitor_request(
 851                     mt, array->elems[i], &allocated_columns);
 852                 if (error) {
 853                     goto error;
 854                 }
 855             }
 856         } else {
 857             error = ovsdb_jsonrpc_parse_monitor_request(
 858                 mt, mr_value, &allocated_columns);
 859             if (error) {
 860                 goto error;
 861             }
 862         }
 863
 864         /* Check for duplicate columns. */
 865         qsort(mt->columns, mt->n_columns, sizeof *mt->columns,
 866               compare_ovsdb_jsonrpc_monitor_column);
 867         for (i = 1; i < mt->n_columns; i++) {
 868             if (mt->columns[i].column == mt->columns[i - 1].column) {
 869                 error = ovsdb_syntax_error(mr_value, NULL, "column %s "
 870                                            "mentioned more than once",
 871                                            mt->columns[i].column->name);
 872                 goto error;
 873             }
 874         }
 875     }
 876
 877     return ovsdb_jsonrpc_monitor_get_initial(m);
 878
 879 error:
 880     if (m) {
 881         ovsdb_remove_replica(s->remote->server->db, &m->replica);
 882     }
 883
 884     json = ovsdb_error_to_json(error);
 885     ovsdb_error_destroy(error);
 886     return json;
 887 }
 888
 889 static struct jsonrpc_msg *
 890 ovsdb_jsonrpc_monitor_cancel(struct ovsdb_jsonrpc_session *s,
 891                              struct json_array *params,
 892                              const struct json *request_id)
 893 {
 894     if (params->n != 1) {
 895         return jsonrpc_create_error(json_string_create("invalid parameters"),
 896                                     request_id);
 897     } else {
 898         struct ovsdb_jsonrpc_monitor *m;
 899
 900         m = ovsdb_jsonrpc_monitor_find(s, params->elems[0]);
 901         if (!m) {
 902             return jsonrpc_create_error(json_string_create("unknown monitor"),
 903                                         request_id);
 904         } else {
 905             ovsdb_remove_replica(s->remote->server->db, &m->replica);
 906             return jsonrpc_create_reply(json_object_create(), request_id);
 907         }
 908     }
 909 }
 910
 911 static void
 912 ovsdb_jsonrpc_monitor_remove_all(struct ovsdb_jsonrpc_session *s)
 913 {
 914     struct ovsdb_jsonrpc_monitor *m, *next;
 915
 916     HMAP_FOR_EACH_SAFE (m, next, node, &s->monitors) {
 917         ovsdb_remove_replica(s->remote->server->db, &m->replica);
 918     }
 919 }
 920
 921 static struct ovsdb_jsonrpc_monitor *
 922 ovsdb_jsonrpc_monitor_cast(struct ovsdb_replica *replica)
 923 {
 924     assert(replica->class == &ovsdb_jsonrpc_replica_class);
 925     return CONTAINER_OF(replica, struct ovsdb_jsonrpc_monitor, replica);
 926 }
 927
 928 struct ovsdb_jsonrpc_monitor_aux {
 929     bool initial;               /* Sending initial contents of table? */
 930     const struct ovsdb_jsonrpc_monitor *monitor;
 931     struct json *json;          /* JSON for the whole transaction. */
 932
 933     /* Current table.  */
 934     struct ovsdb_jsonrpc_monitor_table *mt;
 935     struct json *table_json;    /* JSON for table's transaction. */
 936 };
 937
 938 static bool
 939 ovsdb_jsonrpc_monitor_change_cb(const struct ovsdb_row *old,
 940                                 const struct ovsdb_row *new,
 941                                 const unsigned long int *changed,
 942                                 void *aux_)
 943 {
 944     struct ovsdb_jsonrpc_monitor_aux *aux = aux_;
 945     const struct ovsdb_jsonrpc_monitor *m = aux->monitor;
 946     struct ovsdb_table *table = new ? new->table : old->table;
 947     enum ovsdb_jsonrpc_monitor_selection type;
 948     struct json *old_json, *new_json;
 949     struct json *row_json;
 950     char uuid[UUID_LEN + 1];
 951     int n_changed;
 952     size_t i;
 953
 954     if (!aux->mt || table != aux->mt->table) {
 955         aux->mt = shash_find_data(&m->tables, table->schema->name);
 956         aux->table_json = NULL;
 957         if (!aux->mt) {
 958             /* We don't care about rows in this table at all.  Tell the caller
 959              * to skip it.  */
 960             return false;
 961         }
 962     }
 963
 964     type = (aux->initial ? OJMS_INITIAL
 965             : !old ? OJMS_INSERT
 966             : !new ? OJMS_DELETE
 967             : OJMS_MODIFY);
 968     if (!(aux->mt->select & type)) {
 969         /* We don't care about this type of change (but do want to be called
 970          * back for changes to other rows in the same table). */
 971         return true;
 972     }
 973
 974     old_json = new_json = NULL;
 975     n_changed = 0;
 976     for (i = 0; i < aux->mt->n_columns; i++) {
 977         const struct ovsdb_jsonrpc_monitor_column *c = &aux->mt->columns[i];
 978         const struct ovsdb_column *column = c->column;
 979         unsigned int idx = c->column->index;
 980         bool column_changed = false;
 981
 982         if (!(type & c->select)) {
 983             /* We don't care about this type of change for this particular
 984              * column (but we will care about it for some other column). */
 985             continue;
 986         }
 987
 988         if (type == OJMS_MODIFY) {
 989             column_changed = bitmap_is_set(changed, idx);
 990             n_changed += column_changed;
 991         }
 992         if (column_changed || type == OJMS_DELETE) {
 993             if (!old_json) {
 994                 old_json = json_object_create();
 995             }
 996             json_object_put(old_json, column->name,
 997                             ovsdb_datum_to_json(&old->fields[idx],
 998                                                 &column->type));
 999         }
1000         if (type & (OJMS_INITIAL | OJMS_INSERT | OJMS_MODIFY)) {
1001             if (!new_json) {
1002                 new_json = json_object_create();
1003             }
1004             json_object_put(new_json, column->name,
1005                             ovsdb_datum_to_json(&new->fields[idx],
1006                                                 &column->type));
1007         }
1008     }
1009     if ((type == OJMS_MODIFY && !n_changed) || (!old_json && !new_json)) {
1010         /* No reportable changes. */
1011         json_destroy(old_json);
1012         json_destroy(new_json);
1013         return true;
1014     }
1015
1016     /* Create JSON object for transaction overall. */
1017     if (!aux->json) {
1018         aux->json = json_object_create();
1019     }
1020
1021     /* Create JSON object for transaction on this table. */
1022     if (!aux->table_json) {
1023         aux->table_json = json_object_create();
1024         json_object_put(aux->json, aux->mt->table->schema->name,
1025                         aux->table_json);
1026     }
1027
1028     /* Create JSON object for transaction on this row. */
1029     row_json = json_object_create();
1030     if (old_json) {
1031         json_object_put(row_json, "old", old_json);
1032     }
1033     if (new_json) {
1034         json_object_put(row_json, "new", new_json);
1035     }
1036
1037     /* Add JSON row to JSON table. */
1038     snprintf(uuid, sizeof uuid,
1039              UUID_FMT, UUID_ARGS(ovsdb_row_get_uuid(new ? new : old)));
1040     json_object_put(aux->table_json, uuid, row_json);
1041
1042     return true;
1043 }
1044
1045 static void
1046 ovsdb_jsonrpc_monitor_init_aux(struct ovsdb_jsonrpc_monitor_aux *aux,
1047                                const struct ovsdb_jsonrpc_monitor *m,
1048                                bool initial)
1049 {
1050     aux->initial = initial;
1051     aux->monitor = m;
1052     aux->json = NULL;
1053     aux->mt = NULL;
1054     aux->table_json = NULL;
1055 }
1056
1057 static struct ovsdb_error *
1058 ovsdb_jsonrpc_monitor_commit(struct ovsdb_replica *replica,
1059                              const struct ovsdb_txn *txn,
1060                              bool durable OVS_UNUSED)
1061 {
1062     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1063     struct ovsdb_jsonrpc_monitor_aux aux;
1064
1065     ovsdb_jsonrpc_monitor_init_aux(&aux, m, false);
1066     ovsdb_txn_for_each_change(txn, ovsdb_jsonrpc_monitor_change_cb, &aux);
1067     if (aux.json) {
1068         struct jsonrpc_msg *msg;
1069         struct json *params;
1070
1071         params = json_array_create_2(json_clone(aux.monitor->monitor_id),
1072                                      aux.json);
1073         msg = jsonrpc_create_notify("update", params);
1074         jsonrpc_session_send(aux.monitor->session->js, msg);
1075     }
1076
1077     return NULL;
1078 }
1079
1080 static struct json *
1081 ovsdb_jsonrpc_monitor_get_initial(const struct ovsdb_jsonrpc_monitor *m)
1082 {
1083     struct ovsdb_jsonrpc_monitor_aux aux;
1084     struct shash_node *node;
1085
1086     ovsdb_jsonrpc_monitor_init_aux(&aux, m, true);
1087     SHASH_FOR_EACH (node, &m->tables) {
1088         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1089
1090         if (mt->select & OJMS_INITIAL) {
1091             struct ovsdb_row *row;
1092
1093             HMAP_FOR_EACH (row, hmap_node, &mt->table->rows) {
1094                 ovsdb_jsonrpc_monitor_change_cb(NULL, row, NULL, &aux);
1095             }
1096         }
1097     }
1098     return aux.json ? aux.json : json_object_create();
1099 }
1100
1101 static void
1102 ovsdb_jsonrpc_monitor_destroy(struct ovsdb_replica *replica)
1103 {
1104     struct ovsdb_jsonrpc_monitor *m = ovsdb_jsonrpc_monitor_cast(replica);
1105     struct shash_node *node;
1106
1107     json_destroy(m->monitor_id);
1108     SHASH_FOR_EACH (node, &m->tables) {
1109         struct ovsdb_jsonrpc_monitor_table *mt = node->data;
1110         free(mt->columns);
1111         free(mt);
1112     }
1113     shash_destroy(&m->tables);
1114     hmap_remove(&m->session->monitors, &m->node);
1115     free(m);
1116 }
1117
1118 static const struct ovsdb_replica_class ovsdb_jsonrpc_replica_class = {
1119     ovsdb_jsonrpc_monitor_commit,
1120     ovsdb_jsonrpc_monitor_destroy
1121 };