src/afb-stub-ws.c

   1 /*
   2  * Copyright (C) 2015-2018 "IoT.bzh"
   3  * Author José Bollo <jose.bollo@iot.bzh>
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *   http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #define _GNU_SOURCE
  19
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <assert.h>
  23 #include <fcntl.h>
  24 #include <unistd.h>
  25 #include <errno.h>
  26 #include <endian.h>
  27 #include <netdb.h>
  28 #include <sys/types.h>
  29 #include <sys/socket.h>
  30 #include <sys/un.h>
  31 #include <pthread.h>
  32
  33 #include <json-c/json.h>
  34
  35 #include <afb/afb-event-x2.h>
  36
  37 #include "afb-session.h"
  38 #include "afb-cred.h"
  39 #include "afb-api.h"
  40 #include "afb-apiset.h"
  41 #include "afb-proto-ws.h"
  42 #include "afb-stub-ws.h"
  43 #include "afb-context.h"
  44 #include "afb-evt.h"
  45 #include "afb-xreq.h"
  46 #include "verbose.h"
  47 #include "fdev.h"
  48 #include "jobs.h"
  49
  50 struct afb_stub_ws;
  51
  52
  53 /**
  54  * structure for a ws request: requests on server side
  55  */
  56 struct server_req {
  57         struct afb_xreq xreq;           /**< the xreq */
  58         struct afb_stub_ws *stubws;     /**< the client of the request */
  59         struct afb_proto_ws_call *call; /**< the incoming call */
  60 };
  61
  62 /**
  63  * structure for recording events on client side
  64  */
  65 struct client_event
  66 {
  67         struct client_event *next;      /**< link to the next */
  68         struct afb_event_x2 *event;     /**< the local event */
  69         int id;                         /**< the identifier */
  70         int refcount;                   /**< a reference count */
  71 };
  72
  73 /**
  74  * structure for recording describe requests on the client side
  75  */
  76 struct client_describe
  77 {
  78         struct afb_stub_ws *stubws;     /**< the stub */
  79         struct jobloop *jobloop;        /**< the jobloop to leave */
  80         struct json_object *result;     /**< result */
  81 };
  82
  83 /**
  84  * structure for jobs of describing
  85  */
  86 struct server_describe
  87 {
  88         struct afb_stub_ws *stubws;
  89         struct afb_proto_ws_describe *describe;
  90 };
  91
  92 /**
  93  * structure for recording sessions
  94  */
  95 struct server_session
  96 {
  97         struct server_session *next;
  98         struct afb_session *session;
  99 };
 100
 101 /******************* stub description for client or servers ******************/
 102
 103 struct afb_stub_ws
 104 {
 105         /* protocol */
 106         struct afb_proto_ws *proto;
 107
 108         /* apiset */
 109         struct afb_apiset *apiset;
 110
 111         /* on hangup callback */
 112         void (*on_hangup)(struct afb_stub_ws *);
 113
 114         union {
 115                 /* server side */
 116                 struct {
 117                         /* listener for events */
 118                         struct afb_evt_listener *listener;
 119
 120                         /* sessions */
 121                         struct server_session *sessions;
 122
 123                         /* credentials of the client */
 124                         struct afb_cred *cred;
 125                 };
 126
 127                 /* client side */
 128                 struct {
 129                         /* event replica  */
 130                         struct client_event *events;
 131
 132                         /* robustify */
 133                         struct {
 134                                 struct fdev *(*reopen)(void*);
 135                                 void *closure;
 136                                 void (*release)(void*);
 137                         } robust;
 138                 };
 139         };
 140
 141         /* count of references */
 142         unsigned refcount;
 143
 144         /* type of the stub: 0=server, 1=client */
 145         uint8_t is_client;
 146
 147         /* the api name */
 148         char apiname[1];
 149 };
 150
 151 static struct afb_proto_ws *afb_stub_ws_create_proto(struct afb_stub_ws *stubws, struct fdev *fdev, uint8_t server);
 152
 153 /******************* ws request part for server *****************/
 154
 155 /* decrement the reference count of the request and free/release it on falling to null */
 156 static void server_req_destroy_cb(struct afb_xreq *xreq)
 157 {
 158         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 159
 160         afb_context_disconnect(&wreq->xreq.context);
 161         afb_cred_unref(wreq->xreq.cred);
 162         json_object_put(wreq->xreq.json);
 163         afb_proto_ws_call_unref(wreq->call);
 164         afb_stub_ws_unref(wreq->stubws);
 165         free(wreq);
 166 }
 167
 168 static void server_req_reply_cb(struct afb_xreq *xreq, struct json_object *obj, const char *error, const char *info)
 169 {
 170         int rc;
 171         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 172
 173         rc = afb_proto_ws_call_reply(wreq->call, obj, error, info);
 174         if (rc < 0)
 175                 ERROR("error while sending reply");
 176         json_object_put(obj);
 177 }
 178
 179 static int server_req_subscribe_cb(struct afb_xreq *xreq, struct afb_event_x2 *event)
 180 {
 181         int rc;
 182         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 183
 184         rc = afb_evt_event_x2_add_watch(wreq->stubws->listener, event);
 185         if (rc >= 0)
 186                 rc = afb_proto_ws_call_subscribe(wreq->call,  afb_evt_event_x2_fullname(event), afb_evt_event_x2_id(event));
 187         if (rc < 0)
 188                 ERROR("error while subscribing event");
 189         return rc;
 190 }
 191
 192 static int server_req_unsubscribe_cb(struct afb_xreq *xreq, struct afb_event_x2 *event)
 193 {
 194         int rc, rc2;
 195         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 196
 197         rc = afb_proto_ws_call_unsubscribe(wreq->call,  afb_evt_event_x2_fullname(event), afb_evt_event_x2_id(event));
 198         rc2 = afb_evt_event_x2_remove_watch(wreq->stubws->listener, event);
 199         if (rc >= 0 && rc2 < 0)
 200                 rc = rc2;
 201         if (rc < 0)
 202                 ERROR("error while unsubscribing event");
 203         return rc;
 204 }
 205
 206 static const struct afb_xreq_query_itf server_req_xreq_itf = {
 207         .reply = server_req_reply_cb,
 208         .unref = server_req_destroy_cb,
 209         .subscribe = server_req_subscribe_cb,
 210         .unsubscribe = server_req_unsubscribe_cb
 211 };
 212
 213 /******************* client part **********************************/
 214
 215 /* destroy all events */
 216 static void client_drop_all_events(struct afb_stub_ws *stubws)
 217 {
 218         struct client_event *ev, *nxt;
 219
 220         nxt = __atomic_exchange_n(&stubws->events, NULL, __ATOMIC_RELAXED);
 221         while (nxt) {
 222                 ev = nxt;
 223                 nxt = ev->next;
 224                 afb_evt_event_x2_unref(ev->event);
 225                 free(ev);
 226         }
 227 }
 228
 229 /* search the event */
 230 static struct client_event *client_event_search(struct afb_stub_ws *stubws, uint32_t eventid, const char *name)
 231 {
 232         struct client_event *ev;
 233
 234         ev = stubws->events;
 235         while (ev != NULL && (ev->id != eventid || 0 != strcmp(afb_evt_event_x2_fullname(ev->event), name)))
 236                 ev = ev->next;
 237
 238         return ev;
 239 }
 240
 241 static struct afb_proto_ws *client_get_proto(struct afb_stub_ws *stubws)
 242 {
 243         struct fdev *fdev;
 244         struct afb_proto_ws *proto;
 245
 246         proto = stubws->proto;
 247         if (proto == NULL && stubws->robust.reopen) {
 248                 fdev = stubws->robust.reopen(stubws->robust.closure);
 249                 if (fdev != NULL)
 250                         proto = afb_stub_ws_create_proto(stubws, fdev, 0);
 251         }
 252         return proto;
 253 }
 254
 255 /* on call, propagate it to the ws service */
 256 static void client_api_call_cb(void * closure, struct afb_xreq *xreq)
 257 {
 258         int rc;
 259         struct afb_stub_ws *stubws = closure;
 260         struct afb_proto_ws *proto;
 261
 262         proto = client_get_proto(stubws);
 263         if (proto == NULL) {
 264                 afb_xreq_reply(xreq, NULL, "disconnected", "server hung up");
 265                 return;
 266         }
 267
 268         rc = afb_proto_ws_client_call(
 269                         proto,
 270                         xreq->request.called_verb,
 271                         afb_xreq_json(xreq),
 272                         afb_session_uuid(xreq->context.session),
 273                         xreq,
 274                         xreq_on_behalf_cred_export(xreq));
 275         if (rc >= 0)
 276                 afb_xreq_unhooked_addref(xreq);
 277         else
 278                 afb_xreq_reply(xreq, NULL, "internal", "can't send message");
 279 }
 280
 281 static void client_on_description_cb(void *closure, struct json_object *data)
 282 {
 283         struct client_describe *desc = closure;
 284
 285         desc->result = data;
 286         jobs_leave(desc->jobloop);
 287 }
 288
 289 static void client_send_describe_cb(int signum, void *closure, struct jobloop *jobloop)
 290 {
 291         struct client_describe *desc = closure;
 292         struct afb_proto_ws *proto;
 293
 294         proto = client_get_proto(desc->stubws);
 295         if (signum || proto == NULL)
 296                 jobs_leave(jobloop);
 297         else {
 298                 desc->jobloop = jobloop;
 299                 afb_proto_ws_client_describe(proto, client_on_description_cb, desc);
 300         }
 301 }
 302
 303 /* get the description */
 304 static struct json_object *client_api_describe_cb(void * closure)
 305 {
 306         struct client_describe desc;
 307
 308         /* synchronous job: send the request and wait its result */
 309         desc.stubws = closure;
 310         desc.result = NULL;
 311         jobs_enter(NULL, 0, client_send_describe_cb, &desc);
 312         return desc.result;
 313 }
 314
 315 /******************* server part: manage events **********************************/
 316
 317 static void server_event_add_cb(void *closure, const char *event, int eventid)
 318 {
 319         struct afb_stub_ws *stubws = closure;
 320
 321         if (stubws->proto != NULL)
 322                 afb_proto_ws_server_event_create(stubws->proto, event, eventid);
 323 }
 324
 325 static void server_event_remove_cb(void *closure, const char *event, int eventid)
 326 {
 327         struct afb_stub_ws *stubws = closure;
 328
 329         if (stubws->proto != NULL)
 330                 afb_proto_ws_server_event_remove(stubws->proto, event, eventid);
 331 }
 332
 333 static void server_event_push_cb(void *closure, const char *event, int eventid, struct json_object *object)
 334 {
 335         struct afb_stub_ws *stubws = closure;
 336
 337         if (stubws->proto != NULL)
 338                 afb_proto_ws_server_event_push(stubws->proto, event, eventid, object);
 339         json_object_put(object);
 340 }
 341
 342 static void server_event_broadcast_cb(void *closure, const char *event, int eventid, struct json_object *object)
 343 {
 344         struct afb_stub_ws *stubws = closure;
 345
 346         if (stubws->proto != NULL)
 347                 afb_proto_ws_server_event_broadcast(stubws->proto, event, object);
 348         json_object_put(object);
 349 }
 350
 351 /*****************************************************/
 352
 353 static void client_on_reply_cb(void *closure, void *request, struct json_object *object, const char *error, const char *info)
 354 {
 355         struct afb_xreq *xreq = request;
 356
 357         afb_xreq_reply(xreq, object, error, info);
 358         afb_xreq_unhooked_unref(xreq);
 359 }
 360
 361 static void client_on_event_create_cb(void *closure, const char *event_name, int event_id)
 362 {
 363         struct afb_stub_ws *stubws = closure;
 364         struct client_event *ev;
 365
 366         /* check conflicts */
 367         ev = client_event_search(stubws, event_id, event_name);
 368         if (ev != NULL) {
 369                 __atomic_add_fetch(&ev->refcount, 1, __ATOMIC_RELAXED);
 370                 return;
 371         }
 372
 373         /* no conflict, try to add it */
 374         ev = malloc(sizeof *ev);
 375         if (ev != NULL) {
 376                 ev->event = afb_evt_event_x2_create(event_name);
 377                 if (ev->event != NULL) {
 378                         ev->refcount = 1;
 379                         ev->id = event_id;
 380                         ev->next = stubws->events;
 381                         stubws->events = ev;
 382                         return;
 383                 }
 384                 free(ev);
 385         }
 386         ERROR("can't create event %s, out of memory", event_name);
 387 }
 388
 389 static void client_on_event_remove_cb(void *closure, const char *event_name, int event_id)
 390 {
 391         struct afb_stub_ws *stubws = closure;
 392         struct client_event *ev, **prv;
 393
 394         /* check conflicts */
 395         ev = client_event_search(stubws, event_id, event_name);
 396         if (ev == NULL)
 397                 return;
 398
 399         /* decrease the reference count */
 400
 401         if (__atomic_sub_fetch(&ev->refcount, 1, __ATOMIC_RELAXED))
 402                 return;
 403
 404         /* unlinks the event */
 405         prv = &stubws->events;
 406         while (*prv != ev)
 407                 prv = &(*prv)->next;
 408         *prv = ev->next;
 409
 410         /* destroys the event */
 411         afb_evt_event_x2_unref(ev->event);
 412         free(ev);
 413 }
 414
 415 static void client_on_event_subscribe_cb(void *closure, void *request, const char *event_name, int event_id)
 416 {
 417         struct afb_stub_ws *stubws = closure;
 418         struct afb_xreq *xreq = request;
 419         struct client_event *ev;
 420
 421         /* check conflicts */
 422         ev = client_event_search(stubws, event_id, event_name);
 423         if (ev == NULL)
 424                 return;
 425
 426         if (afb_xreq_subscribe(xreq, ev->event) < 0)
 427                 ERROR("can't subscribe: %m");
 428 }
 429
 430 static void client_on_event_unsubscribe_cb(void *closure, void *request, const char *event_name, int event_id)
 431 {
 432         struct afb_stub_ws *stubws = closure;
 433         struct afb_xreq *xreq = request;
 434         struct client_event *ev;
 435
 436         /* check conflicts */
 437         ev = client_event_search(stubws, event_id, event_name);
 438         if (ev == NULL)
 439                 return;
 440
 441         if (afb_xreq_unsubscribe(xreq, ev->event) < 0)
 442                 ERROR("can't unsubscribe: %m");
 443 }
 444
 445 static void client_on_event_push_cb(void *closure, const char *event_name, int event_id, struct json_object *data)
 446 {
 447         struct afb_stub_ws *stubws = closure;
 448         struct client_event *ev;
 449
 450         /* check conflicts */
 451         ev = client_event_search(stubws, event_id, event_name);
 452         if (ev)
 453                 afb_evt_event_x2_push(ev->event, data);
 454         else
 455                 ERROR("unreadable push event");
 456 }
 457
 458 static void client_on_event_broadcast_cb(void *closure, const char *event_name, struct json_object *data)
 459 {
 460         afb_evt_broadcast(event_name, data);
 461 }
 462
 463 /*****************************************************/
 464
 465 static void server_record_session(struct afb_stub_ws *stubws, struct afb_session *session)
 466 {
 467         struct server_session *s, **prv;
 468
 469         /* search */
 470         prv = &stubws->sessions;
 471         while ((s = *prv)) {
 472                 if (s->session == session)
 473                         return;
 474                 if (afb_session_is_closed(s->session)) {
 475                         *prv = s->next;
 476                         afb_session_unref(s->session);
 477                         free(s);
 478                 }
 479                 else
 480                         prv = &s->next;
 481         }
 482
 483         /* create */
 484         s = malloc(sizeof *s);
 485         if (s) {
 486                 s->session = afb_session_addref(session);
 487                 s->next = stubws->sessions;
 488                 stubws->sessions = s;
 489         }
 490 }
 491
 492 static void server_release_all_sessions(struct afb_stub_ws *stubws)
 493 {
 494         struct server_session *ses, *nses;
 495
 496         nses = __atomic_exchange_n(&stubws->sessions, NULL, __ATOMIC_RELAXED);
 497         while(nses) {
 498                 ses = nses;
 499                 nses = ses->next;
 500                 afb_session_unref(ses->session);
 501                 free(ses);
 502         }
 503 }
 504
 505 /*****************************************************/
 506
 507 static void server_on_call_cb(void *closure, struct afb_proto_ws_call *call, const char *verb, struct json_object *args, const char *sessionid, const char *user_creds)
 508 {
 509         struct afb_stub_ws *stubws = closure;
 510         struct server_req *wreq;
 511
 512         afb_stub_ws_addref(stubws);
 513
 514         /* create the request */
 515         wreq = malloc(sizeof *wreq);
 516         if (wreq == NULL)
 517                 goto out_of_memory;
 518
 519         afb_xreq_init(&wreq->xreq, &server_req_xreq_itf);
 520         wreq->stubws = stubws;
 521         wreq->call = call;
 522
 523         /* init the context */
 524         if (afb_context_connect(&wreq->xreq.context, sessionid, NULL) < 0)
 525                 goto unconnected;
 526         wreq->xreq.context.validated = 1;
 527         server_record_session(stubws, wreq->xreq.context.session);
 528         if (wreq->xreq.context.created)
 529                 afb_session_set_autoclose(wreq->xreq.context.session, 1);
 530
 531         /* makes the call */
 532         wreq->xreq.cred = afb_cred_mixed_on_behalf_import(stubws->cred, sessionid, user_creds);
 533         wreq->xreq.request.called_api = stubws->apiname;
 534         wreq->xreq.request.called_verb = verb;
 535         wreq->xreq.json = args;
 536         afb_xreq_process(&wreq->xreq, stubws->apiset);
 537         return;
 538
 539 unconnected:
 540         free(wreq);
 541 out_of_memory:
 542         json_object_put(args);
 543         afb_stub_ws_unref(stubws);
 544         afb_proto_ws_call_reply(call, NULL, "internal-error", NULL);
 545         afb_proto_ws_call_unref(call);
 546 }
 547
 548 static void server_describe_cb(int signum, void *closure)
 549 {
 550         struct json_object *obj;
 551         struct server_describe *desc = closure;
 552
 553         /* get the description if possible */
 554         obj = !signum ? afb_apiset_describe(desc->stubws->apiset, desc->stubws->apiname) : NULL;
 555
 556         /* send it */
 557         afb_proto_ws_describe_put(desc->describe, obj);
 558         json_object_put(obj);
 559         afb_stub_ws_unref(desc->stubws);
 560 }
 561
 562 static void server_describe_job(int signum, void *closure)
 563 {
 564         server_describe_cb(signum, closure);
 565         free(closure);
 566 }
 567
 568 static void server_on_describe_cb(void *closure, struct afb_proto_ws_describe *describe)
 569 {
 570         struct server_describe *desc, sdesc;
 571         struct afb_stub_ws *stubws = closure;
 572
 573         /* allocate (if possible) and init */
 574         desc = malloc(sizeof *desc);
 575         if (desc == NULL)
 576                 desc = &sdesc;
 577         desc->stubws = stubws;
 578         desc->describe = describe;
 579         afb_stub_ws_addref(stubws);
 580
 581         /* process */
 582         if (desc == &sdesc || jobs_queue(NULL, 0, server_describe_job, desc) < 0)
 583                 jobs_call(NULL, 0, server_describe_cb, desc);
 584 }
 585
 586 /*****************************************************/
 587
 588 static const struct afb_proto_ws_client_itf client_itf =
 589 {
 590         .on_reply = client_on_reply_cb,
 591         .on_event_create = client_on_event_create_cb,
 592         .on_event_remove = client_on_event_remove_cb,
 593         .on_event_subscribe = client_on_event_subscribe_cb,
 594         .on_event_unsubscribe = client_on_event_unsubscribe_cb,
 595         .on_event_push = client_on_event_push_cb,
 596         .on_event_broadcast = client_on_event_broadcast_cb,
 597 };
 598
 599 static struct afb_api_itf client_api_itf = {
 600         .call = client_api_call_cb,
 601         .describe = client_api_describe_cb
 602 };
 603
 604 static const struct afb_proto_ws_server_itf server_itf =
 605 {
 606         .on_call = server_on_call_cb,
 607         .on_describe = server_on_describe_cb
 608 };
 609
 610 /* the interface for events pushing */
 611 static const struct afb_evt_itf server_event_itf = {
 612         .broadcast = server_event_broadcast_cb,
 613         .push = server_event_push_cb,
 614         .add = server_event_add_cb,
 615         .remove = server_event_remove_cb
 616 };
 617
 618 /*****************************************************/
 619
 620 /* disconnect */
 621 static void disconnect(struct afb_stub_ws *stubws)
 622 {
 623         afb_proto_ws_unref(__atomic_exchange_n(&stubws->proto, NULL, __ATOMIC_RELAXED));
 624         if (stubws->is_client)
 625                 client_drop_all_events(stubws);
 626         else {
 627                 afb_evt_listener_unref(__atomic_exchange_n(&stubws->listener, NULL, __ATOMIC_RELAXED));
 628                 afb_cred_unref(__atomic_exchange_n(&stubws->cred, NULL, __ATOMIC_RELAXED));
 629                 server_release_all_sessions(stubws);
 630         }
 631 }
 632
 633
 634 /* callback when receiving a hangup */
 635 static void on_hangup(void *closure)
 636 {
 637         struct afb_stub_ws *stubws = closure;
 638
 639         if (stubws->proto) {
 640                 afb_stub_ws_addref(stubws);
 641                 disconnect(stubws);
 642                 if (stubws->on_hangup)
 643                         stubws->on_hangup(stubws);
 644                 afb_stub_ws_unref(stubws);
 645         }
 646 }
 647
 648 static int enqueue_processing(void (*callback)(int signum, void* arg), void *arg)
 649 {
 650         return jobs_queue(NULL, 0, callback, arg);
 651 }
 652
 653 /*****************************************************/
 654
 655 static struct afb_proto_ws *afb_stub_ws_create_proto(struct afb_stub_ws *stubws, struct fdev *fdev, uint8_t is_client)
 656 {
 657         struct afb_proto_ws *proto;
 658
 659         stubws->proto = proto = is_client
 660                   ? afb_proto_ws_create_client(fdev, &client_itf, stubws)
 661                   : afb_proto_ws_create_server(fdev, &server_itf, stubws);
 662         if (proto) {
 663                 afb_proto_ws_on_hangup(proto, on_hangup);
 664                 afb_proto_ws_set_queuing(proto, enqueue_processing);
 665         }
 666
 667         return proto;
 668 }
 669
 670 static struct afb_stub_ws *afb_stub_ws_create(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset, uint8_t is_client)
 671 {
 672         struct afb_stub_ws *stubws;
 673
 674         stubws = calloc(1, sizeof *stubws + strlen(apiname));
 675         if (stubws == NULL)
 676                 errno = ENOMEM;
 677         else {
 678                 if (afb_stub_ws_create_proto(stubws, fdev, is_client)) {
 679                         stubws->refcount = 1;
 680                         stubws->is_client = is_client;
 681                         strcpy(stubws->apiname, apiname);
 682                         stubws->apiset = afb_apiset_addref(apiset);
 683                         return stubws;
 684                 }
 685                 free(stubws);
 686         }
 687         fdev_unref(fdev);
 688         return NULL;
 689 }
 690
 691 struct afb_stub_ws *afb_stub_ws_create_client(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset)
 692 {
 693         return afb_stub_ws_create(fdev, apiname, apiset, 1);
 694 }
 695
 696 struct afb_stub_ws *afb_stub_ws_create_server(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset)
 697 {
 698         struct afb_stub_ws *stubws;
 699
 700         stubws = afb_stub_ws_create(fdev, apiname, apiset, 0);
 701         if (stubws) {
 702                 stubws->cred = afb_cred_create_for_socket(fdev_fd(fdev));
 703                 stubws->listener = afb_evt_listener_create(&server_event_itf, stubws);
 704                 if (stubws->listener != NULL)
 705                         return stubws;
 706                 afb_stub_ws_unref(stubws);
 707         }
 708         return NULL;
 709 }
 710
 711 void afb_stub_ws_unref(struct afb_stub_ws *stubws)
 712 {
 713         if (stubws && !__atomic_sub_fetch(&stubws->refcount, 1, __ATOMIC_RELAXED)) {
 714
 715                 if (stubws->is_client) {
 716                         stubws->robust.reopen = NULL;
 717                         if (stubws->robust.release)
 718                                 stubws->robust.release(stubws->robust.closure);
 719                 }
 720
 721                 disconnect(stubws);
 722                 afb_apiset_unref(stubws->apiset);
 723                 free(stubws);
 724         }
 725 }
 726
 727 void afb_stub_ws_addref(struct afb_stub_ws *stubws)
 728 {
 729         __atomic_add_fetch(&stubws->refcount, 1, __ATOMIC_RELAXED);
 730 }
 731
 732 void afb_stub_ws_set_on_hangup(struct afb_stub_ws *stubws, void (*on_hangup)(struct afb_stub_ws*))
 733 {
 734         stubws->on_hangup = on_hangup;
 735 }
 736
 737 const char *afb_stub_ws_name(struct afb_stub_ws *stubws)
 738 {
 739         return stubws->apiname;
 740 }
 741
 742 struct afb_api_item afb_stub_ws_client_api(struct afb_stub_ws *stubws)
 743 {
 744         struct afb_api_item api;
 745
 746         assert(stubws->is_client); /* check client */
 747         api.closure = stubws;
 748         api.itf = &client_api_itf;
 749         api.group = stubws; /* serialize for reconnections */
 750         return api;
 751 }
 752
 753 int afb_stub_ws_client_add(struct afb_stub_ws *stubws, struct afb_apiset *apiset)
 754 {
 755         return afb_apiset_add(apiset, stubws->apiname, afb_stub_ws_client_api(stubws));
 756 }
 757
 758 void afb_stub_ws_client_robustify(struct afb_stub_ws *stubws, struct fdev *(*reopen)(void*), void *closure, void (*release)(void*))
 759 {
 760         assert(stubws->is_client); /* check client */
 761
 762         if (stubws->robust.release)
 763                 stubws->robust.release(stubws->robust.closure);
 764
 765         stubws->robust.reopen = reopen;
 766         stubws->robust.closure = closure;
 767         stubws->robust.release = release;
 768 }