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         DEBUG("searching event %s[%d]: %s", name, eventid, ev ? "found" : "not found");
 239         return ev;
 240 }
 241
 242 static struct afb_proto_ws *client_get_proto(struct afb_stub_ws *stubws)
 243 {
 244         struct fdev *fdev;
 245         struct afb_proto_ws *proto;
 246
 247         proto = stubws->proto;
 248         if (proto == NULL && stubws->robust.reopen) {
 249                 fdev = stubws->robust.reopen(stubws->robust.closure);
 250                 if (fdev != NULL)
 251                         proto = afb_stub_ws_create_proto(stubws, fdev, 0);
 252         }
 253         return proto;
 254 }
 255
 256 /* on call, propagate it to the ws service */
 257 static void client_api_call_cb(void * closure, struct afb_xreq *xreq)
 258 {
 259         int rc;
 260         struct afb_stub_ws *stubws = closure;
 261         struct afb_proto_ws *proto;
 262
 263         proto = client_get_proto(stubws);
 264         if (proto == NULL) {
 265                 afb_xreq_reply(xreq, NULL, "disconnected", "server hung up");
 266                 return;
 267         }
 268
 269         afb_xreq_unhooked_addref(xreq);
 270         rc = afb_proto_ws_client_call(
 271                         proto,
 272                         xreq->request.called_verb,
 273                         afb_xreq_json(xreq),
 274                         afb_session_uuid(xreq->context.session),
 275                         xreq,
 276                         xreq_on_behalf_cred_export(xreq));
 277         if (rc < 0) {
 278                 afb_xreq_reply(xreq, NULL, "internal", "can't send message");
 279                 afb_xreq_unhooked_unref(xreq);
 280         }
 281 }
 282
 283 static void client_on_description_cb(void *closure, struct json_object *data)
 284 {
 285         struct client_describe *desc = closure;
 286
 287         desc->result = data;
 288         jobs_leave(desc->jobloop);
 289 }
 290
 291 static void client_send_describe_cb(int signum, void *closure, struct jobloop *jobloop)
 292 {
 293         struct client_describe *desc = closure;
 294         struct afb_proto_ws *proto;
 295
 296         proto = client_get_proto(desc->stubws);
 297         if (signum || proto == NULL)
 298                 jobs_leave(jobloop);
 299         else {
 300                 desc->jobloop = jobloop;
 301                 afb_proto_ws_client_describe(proto, client_on_description_cb, desc);
 302         }
 303 }
 304
 305 /* get the description */
 306 static struct json_object *client_api_describe_cb(void * closure)
 307 {
 308         struct client_describe desc;
 309
 310         /* synchronous job: send the request and wait its result */
 311         desc.stubws = closure;
 312         desc.result = NULL;
 313         jobs_enter(NULL, 0, client_send_describe_cb, &desc);
 314         return desc.result;
 315 }
 316
 317 /******************* server part: manage events **********************************/
 318
 319 static void server_event_add_cb(void *closure, const char *event, int eventid)
 320 {
 321         struct afb_stub_ws *stubws = closure;
 322
 323         if (stubws->proto != NULL)
 324                 afb_proto_ws_server_event_create(stubws->proto, event, eventid);
 325 }
 326
 327 static void server_event_remove_cb(void *closure, const char *event, int eventid)
 328 {
 329         struct afb_stub_ws *stubws = closure;
 330
 331         if (stubws->proto != NULL)
 332                 afb_proto_ws_server_event_remove(stubws->proto, event, eventid);
 333 }
 334
 335 static void server_event_push_cb(void *closure, const char *event, int eventid, struct json_object *object)
 336 {
 337         struct afb_stub_ws *stubws = closure;
 338
 339         if (stubws->proto != NULL)
 340                 afb_proto_ws_server_event_push(stubws->proto, event, eventid, object);
 341         json_object_put(object);
 342 }
 343
 344 static void server_event_broadcast_cb(void *closure, const char *event, int eventid, struct json_object *object)
 345 {
 346         struct afb_stub_ws *stubws = closure;
 347
 348         if (stubws->proto != NULL)
 349                 afb_proto_ws_server_event_broadcast(stubws->proto, event, object);
 350         json_object_put(object);
 351 }
 352
 353 /*****************************************************/
 354
 355 static void client_on_reply_cb(void *closure, void *request, struct json_object *object, const char *error, const char *info)
 356 {
 357         struct afb_xreq *xreq = request;
 358
 359         afb_xreq_reply(xreq, object, error, info);
 360         afb_xreq_unhooked_unref(xreq);
 361 }
 362
 363 static void client_on_event_create_cb(void *closure, const char *event_name, int event_id)
 364 {
 365         struct afb_stub_ws *stubws = closure;
 366         struct client_event *ev;
 367
 368         /* check conflicts */
 369         ev = client_event_search(stubws, event_id, event_name);
 370         if (ev != NULL) {
 371                 __atomic_add_fetch(&ev->refcount, 1, __ATOMIC_RELAXED);
 372                 return;
 373         }
 374
 375         /* no conflict, try to add it */
 376         ev = malloc(sizeof *ev);
 377         if (ev != NULL) {
 378                 ev->event = afb_evt_event_x2_create(event_name);
 379                 if (ev->event != NULL) {
 380                         ev->refcount = 1;
 381                         ev->id = event_id;
 382                         ev->next = stubws->events;
 383                         stubws->events = ev;
 384                         return;
 385                 }
 386                 free(ev);
 387         }
 388         ERROR("can't create event %s, out of memory", event_name);
 389 }
 390
 391 static void client_on_event_remove_cb(void *closure, const char *event_name, int event_id)
 392 {
 393         struct afb_stub_ws *stubws = closure;
 394         struct client_event *ev, **prv;
 395
 396         /* check conflicts */
 397         ev = client_event_search(stubws, event_id, event_name);
 398         if (ev == NULL)
 399                 return;
 400
 401         /* decrease the reference count */
 402
 403         if (__atomic_sub_fetch(&ev->refcount, 1, __ATOMIC_RELAXED))
 404                 return;
 405
 406         /* unlinks the event */
 407         prv = &stubws->events;
 408         while (*prv != ev)
 409                 prv = &(*prv)->next;
 410         *prv = ev->next;
 411
 412         /* destroys the event */
 413         afb_evt_event_x2_unref(ev->event);
 414         free(ev);
 415 }
 416
 417 static void client_on_event_subscribe_cb(void *closure, void *request, const char *event_name, int event_id)
 418 {
 419         struct afb_stub_ws *stubws = closure;
 420         struct afb_xreq *xreq = request;
 421         struct client_event *ev;
 422
 423         /* check conflicts */
 424         ev = client_event_search(stubws, event_id, event_name);
 425         if (ev == NULL)
 426                 return;
 427
 428         if (afb_xreq_subscribe(xreq, ev->event) < 0)
 429                 ERROR("can't subscribe: %m");
 430 }
 431
 432 static void client_on_event_unsubscribe_cb(void *closure, void *request, const char *event_name, int event_id)
 433 {
 434         struct afb_stub_ws *stubws = closure;
 435         struct afb_xreq *xreq = request;
 436         struct client_event *ev;
 437
 438         /* check conflicts */
 439         ev = client_event_search(stubws, event_id, event_name);
 440         if (ev == NULL)
 441                 return;
 442
 443         if (afb_xreq_unsubscribe(xreq, ev->event) < 0)
 444                 ERROR("can't unsubscribe: %m");
 445 }
 446
 447 static void client_on_event_push_cb(void *closure, const char *event_name, int event_id, struct json_object *data)
 448 {
 449         struct afb_stub_ws *stubws = closure;
 450         struct client_event *ev;
 451
 452         /* check conflicts */
 453         ev = client_event_search(stubws, event_id, event_name);
 454         if (ev)
 455                 afb_evt_event_x2_push(ev->event, data);
 456         else
 457                 ERROR("unreadable push event");
 458 }
 459
 460 static void client_on_event_broadcast_cb(void *closure, const char *event_name, struct json_object *data)
 461 {
 462         afb_evt_broadcast(event_name, data);
 463 }
 464
 465 /*****************************************************/
 466
 467 static void server_record_session(struct afb_stub_ws *stubws, struct afb_session *session)
 468 {
 469         struct server_session *s, **prv;
 470
 471         /* search */
 472         prv = &stubws->sessions;
 473         while ((s = *prv)) {
 474                 if (s->session == session)
 475                         return;
 476                 if (afb_session_is_closed(s->session)) {
 477                         *prv = s->next;
 478                         afb_session_unref(s->session);
 479                         free(s);
 480                 }
 481                 else
 482                         prv = &s->next;
 483         }
 484
 485         /* create */
 486         s = malloc(sizeof *s);
 487         if (s) {
 488                 s->session = afb_session_addref(session);
 489                 s->next = stubws->sessions;
 490                 stubws->sessions = s;
 491         }
 492 }
 493
 494 static void server_release_all_sessions(struct afb_stub_ws *stubws)
 495 {
 496         struct server_session *ses, *nses;
 497
 498         nses = __atomic_exchange_n(&stubws->sessions, NULL, __ATOMIC_RELAXED);
 499         while(nses) {
 500                 ses = nses;
 501                 nses = ses->next;
 502                 afb_session_unref(ses->session);
 503                 free(ses);
 504         }
 505 }
 506
 507 /*****************************************************/
 508
 509 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)
 510 {
 511         struct afb_stub_ws *stubws = closure;
 512         struct server_req *wreq;
 513
 514         afb_stub_ws_addref(stubws);
 515
 516         /* create the request */
 517         wreq = malloc(sizeof *wreq);
 518         if (wreq == NULL)
 519                 goto out_of_memory;
 520
 521         afb_xreq_init(&wreq->xreq, &server_req_xreq_itf);
 522         wreq->stubws = stubws;
 523         wreq->call = call;
 524
 525         /* init the context */
 526         if (afb_context_connect(&wreq->xreq.context, sessionid, NULL) < 0)
 527                 goto unconnected;
 528         wreq->xreq.context.validated = 1;
 529         server_record_session(stubws, wreq->xreq.context.session);
 530         if (wreq->xreq.context.created)
 531                 afb_session_set_autoclose(wreq->xreq.context.session, 1);
 532
 533         /* makes the call */
 534         wreq->xreq.cred = afb_cred_mixed_on_behalf_import(stubws->cred, sessionid, user_creds);
 535         wreq->xreq.request.called_api = stubws->apiname;
 536         wreq->xreq.request.called_verb = verb;
 537         wreq->xreq.json = args;
 538         afb_xreq_process(&wreq->xreq, stubws->apiset);
 539         return;
 540
 541 unconnected:
 542         free(wreq);
 543 out_of_memory:
 544         json_object_put(args);
 545         afb_stub_ws_unref(stubws);
 546         afb_proto_ws_call_reply(call, NULL, "internal-error", NULL);
 547         afb_proto_ws_call_unref(call);
 548 }
 549
 550 static void server_describe_cb(int signum, void *closure)
 551 {
 552         struct json_object *obj;
 553         struct server_describe *desc = closure;
 554
 555         /* get the description if possible */
 556         obj = !signum ? afb_apiset_describe(desc->stubws->apiset, desc->stubws->apiname) : NULL;
 557
 558         /* send it */
 559         afb_proto_ws_describe_put(desc->describe, obj);
 560         json_object_put(obj);
 561         afb_stub_ws_unref(desc->stubws);
 562 }
 563
 564 static void server_describe_job(int signum, void *closure)
 565 {
 566         server_describe_cb(signum, closure);
 567         free(closure);
 568 }
 569
 570 static void server_on_describe_cb(void *closure, struct afb_proto_ws_describe *describe)
 571 {
 572         struct server_describe *desc, sdesc;
 573         struct afb_stub_ws *stubws = closure;
 574
 575         /* allocate (if possible) and init */
 576         desc = malloc(sizeof *desc);
 577         if (desc == NULL)
 578                 desc = &sdesc;
 579         desc->stubws = stubws;
 580         desc->describe = describe;
 581         afb_stub_ws_addref(stubws);
 582
 583         /* process */
 584         if (desc == &sdesc || jobs_queue(NULL, 0, server_describe_job, desc) < 0)
 585                 jobs_call(NULL, 0, server_describe_cb, desc);
 586 }
 587
 588 /*****************************************************/
 589
 590 static const struct afb_proto_ws_client_itf client_itf =
 591 {
 592         .on_reply = client_on_reply_cb,
 593         .on_event_create = client_on_event_create_cb,
 594         .on_event_remove = client_on_event_remove_cb,
 595         .on_event_subscribe = client_on_event_subscribe_cb,
 596         .on_event_unsubscribe = client_on_event_unsubscribe_cb,
 597         .on_event_push = client_on_event_push_cb,
 598         .on_event_broadcast = client_on_event_broadcast_cb,
 599 };
 600
 601 static struct afb_api_itf client_api_itf = {
 602         .call = client_api_call_cb,
 603         .describe = client_api_describe_cb
 604 };
 605
 606 static const struct afb_proto_ws_server_itf server_itf =
 607 {
 608         .on_call = server_on_call_cb,
 609         .on_describe = server_on_describe_cb
 610 };
 611
 612 /* the interface for events pushing */
 613 static const struct afb_evt_itf server_event_itf = {
 614         .broadcast = server_event_broadcast_cb,
 615         .push = server_event_push_cb,
 616         .add = server_event_add_cb,
 617         .remove = server_event_remove_cb
 618 };
 619
 620 /*****************************************************/
 621
 622 /* disconnect */
 623 static void disconnect(struct afb_stub_ws *stubws)
 624 {
 625         afb_proto_ws_unref(__atomic_exchange_n(&stubws->proto, NULL, __ATOMIC_RELAXED));
 626         if (stubws->is_client)
 627                 client_drop_all_events(stubws);
 628         else {
 629                 afb_evt_listener_unref(__atomic_exchange_n(&stubws->listener, NULL, __ATOMIC_RELAXED));
 630                 afb_cred_unref(__atomic_exchange_n(&stubws->cred, NULL, __ATOMIC_RELAXED));
 631                 server_release_all_sessions(stubws);
 632         }
 633 }
 634
 635
 636 /* callback when receiving a hangup */
 637 static void on_hangup(void *closure)
 638 {
 639         struct afb_stub_ws *stubws = closure;
 640
 641         if (stubws->proto) {
 642                 afb_stub_ws_addref(stubws);
 643                 disconnect(stubws);
 644                 if (stubws->on_hangup)
 645                         stubws->on_hangup(stubws);
 646                 afb_stub_ws_unref(stubws);
 647         }
 648 }
 649
 650 static int enqueue_processing(struct afb_proto_ws *proto, void (*callback)(int signum, void* arg), void *arg)
 651 {
 652         return jobs_queue(proto, 0, callback, arg);
 653 }
 654
 655 /*****************************************************/
 656
 657 static struct afb_proto_ws *afb_stub_ws_create_proto(struct afb_stub_ws *stubws, struct fdev *fdev, uint8_t is_client)
 658 {
 659         struct afb_proto_ws *proto;
 660
 661         stubws->proto = proto = is_client
 662                   ? afb_proto_ws_create_client(fdev, &client_itf, stubws)
 663                   : afb_proto_ws_create_server(fdev, &server_itf, stubws);
 664         if (proto) {
 665                 afb_proto_ws_on_hangup(proto, on_hangup);
 666                 afb_proto_ws_set_queuing(proto, enqueue_processing);
 667         }
 668
 669         return proto;
 670 }
 671
 672 static struct afb_stub_ws *afb_stub_ws_create(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset, uint8_t is_client)
 673 {
 674         struct afb_stub_ws *stubws;
 675
 676         stubws = calloc(1, sizeof *stubws + strlen(apiname));
 677         if (stubws == NULL)
 678                 errno = ENOMEM;
 679         else {
 680                 if (afb_stub_ws_create_proto(stubws, fdev, is_client)) {
 681                         stubws->refcount = 1;
 682                         stubws->is_client = is_client;
 683                         strcpy(stubws->apiname, apiname);
 684                         stubws->apiset = afb_apiset_addref(apiset);
 685                         return stubws;
 686                 }
 687                 free(stubws);
 688         }
 689         fdev_unref(fdev);
 690         return NULL;
 691 }
 692
 693 struct afb_stub_ws *afb_stub_ws_create_client(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset)
 694 {
 695         return afb_stub_ws_create(fdev, apiname, apiset, 1);
 696 }
 697
 698 struct afb_stub_ws *afb_stub_ws_create_server(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset)
 699 {
 700         struct afb_stub_ws *stubws;
 701
 702         stubws = afb_stub_ws_create(fdev, apiname, apiset, 0);
 703         if (stubws) {
 704                 stubws->cred = afb_cred_create_for_socket(fdev_fd(fdev));
 705                 stubws->listener = afb_evt_listener_create(&server_event_itf, stubws);
 706                 if (stubws->listener != NULL)
 707                         return stubws;
 708                 afb_stub_ws_unref(stubws);
 709         }
 710         return NULL;
 711 }
 712
 713 void afb_stub_ws_unref(struct afb_stub_ws *stubws)
 714 {
 715         if (stubws && !__atomic_sub_fetch(&stubws->refcount, 1, __ATOMIC_RELAXED)) {
 716
 717                 if (stubws->is_client) {
 718                         stubws->robust.reopen = NULL;
 719                         if (stubws->robust.release)
 720                                 stubws->robust.release(stubws->robust.closure);
 721                 }
 722
 723                 disconnect(stubws);
 724                 afb_apiset_unref(stubws->apiset);
 725                 free(stubws);
 726         }
 727 }
 728
 729 void afb_stub_ws_addref(struct afb_stub_ws *stubws)
 730 {
 731         __atomic_add_fetch(&stubws->refcount, 1, __ATOMIC_RELAXED);
 732 }
 733
 734 void afb_stub_ws_set_on_hangup(struct afb_stub_ws *stubws, void (*on_hangup)(struct afb_stub_ws*))
 735 {
 736         stubws->on_hangup = on_hangup;
 737 }
 738
 739 const char *afb_stub_ws_name(struct afb_stub_ws *stubws)
 740 {
 741         return stubws->apiname;
 742 }
 743
 744 struct afb_api_item afb_stub_ws_client_api(struct afb_stub_ws *stubws)
 745 {
 746         struct afb_api_item api;
 747
 748         assert(stubws->is_client); /* check client */
 749         api.closure = stubws;
 750         api.itf = &client_api_itf;
 751         api.group = stubws; /* serialize for reconnections */
 752         return api;
 753 }
 754
 755 int afb_stub_ws_client_add(struct afb_stub_ws *stubws, struct afb_apiset *apiset)
 756 {
 757         return afb_apiset_add(apiset, stubws->apiname, afb_stub_ws_client_api(stubws));
 758 }
 759
 760 void afb_stub_ws_client_robustify(struct afb_stub_ws *stubws, struct fdev *(*reopen)(void*), void *closure, void (*release)(void*))
 761 {
 762         assert(stubws->is_client); /* check client */
 763
 764         if (stubws->robust.release)
 765                 stubws->robust.release(stubws->robust.closure);
 766
 767         stubws->robust.reopen = reopen;
 768         stubws->robust.closure = closure;
 769         stubws->robust.release = release;
 770 }