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
  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;
  68         struct afb_event_x2 *event;
  69         int id;
  70         int refcount;
  71 };
  72
  73 /*
  74  * structure for recording describe requests
  75  */
  76 struct client_describe
  77 {
  78         struct afb_stub_ws *stubws;
  79         struct jobloop *jobloop;
  80         struct json_object *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         /* count of references */
 106         int refcount;
 107
 108         /* resource control */
 109         pthread_mutex_t mutex;
 110
 111         /* protocol */
 112         struct afb_proto_ws *proto;
 113
 114         /* listener for events (server side) */
 115         struct afb_evt_listener *listener;
 116
 117         /* event replica (client side) */
 118         struct client_event *events;
 119
 120         /* credentials of the client (server side) */
 121         struct afb_cred *cred;
 122
 123         /* sessions (server side) */
 124         struct server_session *sessions;
 125
 126         /* apiset */
 127         struct afb_apiset *apiset;
 128
 129         /* on hangup callback */
 130         void (*on_hangup)(struct afb_stub_ws *);
 131
 132         /* the api name */
 133         char apiname[1];
 134 };
 135
 136 /******************* ws request part for server *****************/
 137
 138 /* decrement the reference count of the request and free/release it on falling to null */
 139 static void server_req_destroy_cb(struct afb_xreq *xreq)
 140 {
 141         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 142
 143         afb_context_disconnect(&wreq->xreq.context);
 144         afb_cred_unref(wreq->xreq.cred);
 145         json_object_put(wreq->xreq.json);
 146         afb_proto_ws_call_unref(wreq->call);
 147         afb_stub_ws_unref(wreq->stubws);
 148         free(wreq);
 149 }
 150
 151 static void server_req_reply_cb(struct afb_xreq *xreq, struct json_object *obj, const char *error, const char *info)
 152 {
 153         int rc;
 154         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 155
 156         rc = afb_proto_ws_call_reply(wreq->call, obj, error, info);
 157         if (rc < 0)
 158                 ERROR("error while sending reply");
 159         json_object_put(obj);
 160 }
 161
 162 static int server_req_subscribe_cb(struct afb_xreq *xreq, struct afb_event_x2 *event)
 163 {
 164         int rc;
 165         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 166
 167         rc = afb_evt_event_x2_add_watch(wreq->stubws->listener, event);
 168         if (rc >= 0)
 169                 rc = afb_proto_ws_call_subscribe(wreq->call,  afb_evt_event_x2_fullname(event), afb_evt_event_x2_id(event));
 170         if (rc < 0)
 171                 ERROR("error while subscribing event");
 172         return rc;
 173 }
 174
 175 static int server_req_unsubscribe_cb(struct afb_xreq *xreq, struct afb_event_x2 *event)
 176 {
 177         int rc, rc2;
 178         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 179
 180         rc = afb_proto_ws_call_unsubscribe(wreq->call,  afb_evt_event_x2_fullname(event), afb_evt_event_x2_id(event));
 181         rc2 = afb_evt_event_x2_remove_watch(wreq->stubws->listener, event);
 182         if (rc >= 0 && rc2 < 0)
 183                 rc = rc2;
 184         if (rc < 0)
 185                 ERROR("error while unsubscribing event");
 186         return rc;
 187 }
 188
 189 static const struct afb_xreq_query_itf server_req_xreq_itf = {
 190         .reply = server_req_reply_cb,
 191         .unref = server_req_destroy_cb,
 192         .subscribe = server_req_subscribe_cb,
 193         .unsubscribe = server_req_unsubscribe_cb
 194 };
 195
 196 /******************* client part **********************************/
 197
 198 /* search the event */
 199 static struct client_event *client_event_search(struct afb_stub_ws *stubws, uint32_t eventid, const char *name)
 200 {
 201         struct client_event *ev;
 202
 203         ev = stubws->events;
 204         while (ev != NULL && (ev->id != eventid || 0 != strcmp(afb_evt_event_x2_fullname(ev->event), name)))
 205                 ev = ev->next;
 206
 207         return ev;
 208 }
 209
 210 /* on call, propagate it to the ws service */
 211 static void client_call_cb(void * closure, struct afb_xreq *xreq)
 212 {
 213         struct afb_stub_ws *stubws = closure;
 214
 215         afb_proto_ws_client_call(
 216                         stubws->proto,
 217                         xreq->request.called_verb,
 218                         afb_xreq_json(xreq),
 219                         afb_session_uuid(xreq->context.session),
 220                         xreq,
 221                         xreq_on_behalf_cred_export(xreq));
 222         afb_xreq_unhooked_addref(xreq);
 223 }
 224
 225 static void client_on_description_cb(void *closure, struct json_object *data)
 226 {
 227         struct client_describe *desc = closure;
 228
 229         desc->result = data;
 230         jobs_leave(desc->jobloop);
 231 }
 232
 233 static void client_send_describe_cb(int signum, void *closure, struct jobloop *jobloop)
 234 {
 235         struct client_describe *desc = closure;
 236
 237         if (signum)
 238                 jobs_leave(jobloop);
 239         else {
 240                 desc->jobloop = jobloop;
 241                 afb_proto_ws_client_describe(desc->stubws->proto, client_on_description_cb, desc);
 242         }
 243 }
 244
 245 /* get the description */
 246 static struct json_object *client_describe_cb(void * closure)
 247 {
 248         struct client_describe desc;
 249
 250         /* synchronous job: send the request and wait its result */
 251         desc.stubws = closure;
 252         desc.result = NULL;
 253         jobs_enter(NULL, 0, client_send_describe_cb, &desc);
 254         return desc.result;
 255 }
 256
 257 /******************* server part: manage events **********************************/
 258
 259 static void server_event_add(void *closure, const char *event, int eventid)
 260 {
 261         struct afb_stub_ws *stubws = closure;
 262
 263         afb_proto_ws_server_event_create(stubws->proto, event, eventid);
 264 }
 265
 266 static void server_event_remove(void *closure, const char *event, int eventid)
 267 {
 268         struct afb_stub_ws *stubws = closure;
 269
 270         afb_proto_ws_server_event_remove(stubws->proto, event, eventid);
 271 }
 272
 273 static void server_event_push(void *closure, const char *event, int eventid, struct json_object *object)
 274 {
 275         struct afb_stub_ws *stubws = closure;
 276
 277         afb_proto_ws_server_event_push(stubws->proto, event, eventid, object);
 278         json_object_put(object);
 279 }
 280
 281 static void server_event_broadcast(void *closure, const char *event, int eventid, struct json_object *object)
 282 {
 283         struct afb_stub_ws *stubws = closure;
 284
 285         afb_proto_ws_server_event_broadcast(stubws->proto, event, object);
 286         json_object_put(object);
 287 }
 288
 289 /*****************************************************/
 290
 291 static void on_reply(void *closure, void *request, struct json_object *object, const char *error, const char *info)
 292 {
 293         struct afb_xreq *xreq = request;
 294
 295         afb_xreq_reply(xreq, object, error, info);
 296         afb_xreq_unhooked_unref(xreq);
 297 }
 298
 299 static void on_event_create(void *closure, const char *event_name, int event_id)
 300 {
 301         struct afb_stub_ws *stubws = closure;
 302         struct client_event *ev;
 303
 304         /* check conflicts */
 305         ev = client_event_search(stubws, event_id, event_name);
 306         if (ev != NULL) {
 307                 ev->refcount++;
 308                 return;
 309         }
 310
 311         /* no conflict, try to add it */
 312         ev = malloc(sizeof *ev);
 313         if (ev != NULL) {
 314                 ev->event = afb_evt_event_x2_create(event_name);
 315                 if (ev->event != NULL) {
 316                         ev->refcount = 1;
 317                         ev->id = event_id;
 318                         ev->next = stubws->events;
 319                         stubws->events = ev;
 320                         return;
 321                 }
 322                 free(ev);
 323         }
 324         ERROR("can't create event %s, out of memory", event_name);
 325 }
 326
 327 static void on_event_remove(void *closure, const char *event_name, int event_id)
 328 {
 329         struct afb_stub_ws *stubws = closure;
 330         struct client_event *ev, **prv;
 331
 332         /* check conflicts */
 333         ev = client_event_search(stubws, event_id, event_name);
 334         if (ev == NULL)
 335                 return;
 336
 337         /* decrease the reference count */
 338         if (--ev->refcount)
 339                 return;
 340
 341         /* unlinks the event */
 342         prv = &stubws->events;
 343         while (*prv != ev)
 344                 prv = &(*prv)->next;
 345         *prv = ev->next;
 346
 347         /* destroys the event */
 348         afb_evt_event_x2_unref(ev->event);
 349         free(ev);
 350 }
 351
 352 static void on_event_subscribe(void *closure, void *request, const char *event_name, int event_id)
 353 {
 354         struct afb_stub_ws *stubws = closure;
 355         struct afb_xreq *xreq = request;
 356         struct client_event *ev;
 357
 358         /* check conflicts */
 359         ev = client_event_search(stubws, event_id, event_name);
 360         if (ev == NULL)
 361                 return;
 362
 363         if (afb_xreq_subscribe(xreq, ev->event) < 0)
 364                 ERROR("can't subscribe: %m");
 365 }
 366
 367 static void on_event_unsubscribe(void *closure, void *request, const char *event_name, int event_id)
 368 {
 369         struct afb_stub_ws *stubws = closure;
 370         struct afb_xreq *xreq = request;
 371         struct client_event *ev;
 372
 373         /* check conflicts */
 374         ev = client_event_search(stubws, event_id, event_name);
 375         if (ev == NULL)
 376                 return;
 377
 378         if (afb_xreq_unsubscribe(xreq, ev->event) < 0)
 379                 ERROR("can't unsubscribe: %m");
 380 }
 381
 382 static void on_event_push(void *closure, const char *event_name, int event_id, struct json_object *data)
 383 {
 384         struct afb_stub_ws *stubws = closure;
 385         struct client_event *ev;
 386
 387         /* check conflicts */
 388         ev = client_event_search(stubws, event_id, event_name);
 389         if (ev)
 390                 afb_evt_event_x2_push(ev->event, data);
 391         else
 392                 ERROR("unreadable push event");
 393 }
 394
 395 static void on_event_broadcast(void *closure, const char *event_name, struct json_object *data)
 396 {
 397         afb_evt_broadcast(event_name, data);
 398 }
 399
 400 /*****************************************************/
 401
 402 static void record_session(struct afb_stub_ws *stubws, struct afb_session *session)
 403 {
 404         struct server_session *s, **prv;
 405
 406         /* search */
 407         prv = &stubws->sessions;
 408         while ((s = *prv)) {
 409                 if (s->session == session)
 410                         return;
 411                 if (afb_session_is_closed(s->session)) {
 412                         *prv = s->next;
 413                         afb_session_unref(s->session);
 414                         free(s);
 415                 }
 416                 else
 417                         prv = &s->next;
 418         }
 419
 420         /* create */
 421         s = malloc(sizeof *s);
 422         if (s) {
 423                 s->session = afb_session_addref(session);
 424                 s->next = stubws->sessions;
 425                 stubws->sessions = s;
 426         }
 427 }
 428
 429 static void release_all_sessions(struct afb_stub_ws *stubws)
 430 {
 431         struct server_session *s, *n;
 432
 433         s = stubws->sessions;
 434         stubws->sessions = NULL;
 435         while(s) {
 436                 n = s->next;
 437                 afb_session_unref(s->session);
 438                 free(s);
 439                 s = n;
 440         }
 441 }
 442
 443 /*****************************************************/
 444
 445 static void on_call(void *closure, struct afb_proto_ws_call *call, const char *verb, struct json_object *args, const char *sessionid, const char *user_creds)
 446 {
 447         struct afb_stub_ws *stubws = closure;
 448         struct server_req *wreq;
 449
 450         afb_stub_ws_addref(stubws);
 451
 452         /* create the request */
 453         wreq = malloc(sizeof *wreq);
 454         if (wreq == NULL)
 455                 goto out_of_memory;
 456
 457         afb_xreq_init(&wreq->xreq, &server_req_xreq_itf);
 458         wreq->stubws = stubws;
 459         wreq->call = call;
 460
 461         /* init the context */
 462         if (afb_context_connect(&wreq->xreq.context, sessionid, NULL) < 0)
 463                 goto unconnected;
 464         wreq->xreq.context.validated = 1;
 465         record_session(stubws, wreq->xreq.context.session);
 466         if (wreq->xreq.context.created)
 467                 afb_session_set_autoclose(wreq->xreq.context.session, 1);
 468
 469         /* makes the call */
 470         wreq->xreq.cred = afb_cred_mixed_on_behalf_import(stubws->cred, sessionid, user_creds);
 471         wreq->xreq.request.called_api = stubws->apiname;
 472         wreq->xreq.request.called_verb = verb;
 473         wreq->xreq.json = args;
 474         afb_xreq_process(&wreq->xreq, stubws->apiset);
 475         return;
 476
 477 unconnected:
 478         free(wreq);
 479 out_of_memory:
 480         json_object_put(args);
 481         afb_stub_ws_unref(stubws);
 482         afb_proto_ws_call_reply(call, NULL, "internal-error", NULL);
 483         afb_proto_ws_call_unref(call);
 484 }
 485
 486 static void server_describe_sjob(int signum, void *closure)
 487 {
 488         struct json_object *obj;
 489         struct server_describe *desc = closure;
 490
 491         /* get the description if possible */
 492         obj = !signum ? afb_apiset_describe(desc->stubws->apiset, desc->stubws->apiname) : NULL;
 493
 494         /* send it */
 495         afb_proto_ws_describe_put(desc->describe, obj);
 496         json_object_put(obj);
 497         afb_stub_ws_unref(desc->stubws);
 498 }
 499
 500 static void server_describe_job(int signum, void *closure)
 501 {
 502         server_describe_sjob(signum, closure);
 503         free(closure);
 504 }
 505
 506 static void on_describe(void *closure, struct afb_proto_ws_describe *describe)
 507 {
 508         struct server_describe *desc, sdesc;
 509         struct afb_stub_ws *stubws = closure;
 510
 511         /* allocate (if possible) and init */
 512         desc = malloc(sizeof *desc);
 513         if (desc == NULL)
 514                 desc = &sdesc;
 515         desc->stubws = stubws;
 516         desc->describe = describe;
 517         afb_stub_ws_addref(stubws);
 518
 519         /* process */
 520         if (desc == &sdesc)
 521                 jobs_call(NULL, 0, server_describe_sjob, desc);
 522         else {
 523                 if (jobs_queue(NULL, 0, server_describe_job, desc) < 0)
 524                         jobs_call(NULL, 0, server_describe_job, desc);
 525         }
 526 }
 527
 528 /*****************************************************/
 529
 530 static const struct afb_proto_ws_client_itf client_itf =
 531 {
 532         .on_reply = on_reply,
 533         .on_event_create = on_event_create,
 534         .on_event_remove = on_event_remove,
 535         .on_event_subscribe = on_event_subscribe,
 536         .on_event_unsubscribe = on_event_unsubscribe,
 537         .on_event_push = on_event_push,
 538         .on_event_broadcast = on_event_broadcast,
 539 };
 540
 541 static const struct afb_proto_ws_server_itf server_itf =
 542 {
 543         .on_call = on_call,
 544         .on_describe = on_describe
 545 };
 546
 547 static struct afb_api_itf ws_api_itf = {
 548         .call = client_call_cb,
 549         .describe = client_describe_cb
 550 };
 551
 552 /* the interface for events pushing */
 553 static const struct afb_evt_itf server_evt_itf = {
 554         .broadcast = server_event_broadcast,
 555         .push = server_event_push,
 556         .add = server_event_add,
 557         .remove = server_event_remove
 558 };
 559
 560 /*****************************************************/
 561
 562 static void drop_all_events(struct afb_stub_ws *stubws)
 563 {
 564         struct client_event *ev, *nxt;
 565
 566         ev = stubws->events;
 567         stubws->events = NULL;
 568
 569         while (ev) {
 570                 nxt = ev->next;
 571                 afb_evt_event_x2_unref(ev->event);
 572                 free(ev);
 573                 ev = nxt;
 574         }
 575 }
 576
 577 /* callback when receiving a hangup */
 578 static void on_hangup(void *closure)
 579 {
 580         struct afb_stub_ws *stubws = closure;
 581
 582         afb_stub_ws_addref(stubws);
 583         if (stubws->on_hangup)
 584                 stubws->on_hangup(stubws);
 585
 586         release_all_sessions(stubws);
 587         afb_stub_ws_unref(stubws);
 588 }
 589
 590 static int enqueue_processing(void (*callback)(int signum, void* arg), void *arg)
 591 {
 592         return jobs_queue(NULL, 0, callback, arg);
 593 }
 594
 595 /*****************************************************/
 596
 597 static struct afb_stub_ws *afb_stub_ws_create(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset, int client)
 598 {
 599         struct afb_stub_ws *stubws;
 600
 601         stubws = calloc(1, sizeof *stubws + strlen(apiname));
 602         if (stubws == NULL)
 603                 errno = ENOMEM;
 604         else {
 605                 if (client)
 606                         stubws->proto = afb_proto_ws_create_client(fdev, &client_itf, stubws);
 607                 else
 608                         stubws->proto = afb_proto_ws_create_server(fdev, &server_itf, stubws);
 609
 610                 if (stubws->proto) {
 611                         strcpy(stubws->apiname, apiname);
 612                         stubws->apiset = afb_apiset_addref(apiset);
 613                         stubws->refcount = 1;
 614                         afb_proto_ws_on_hangup(stubws->proto, on_hangup);
 615                         afb_proto_ws_set_queuing(stubws->proto, enqueue_processing);
 616                         return stubws;
 617                 }
 618                 free(stubws);
 619         }
 620         fdev_unref(fdev);
 621         return NULL;
 622 }
 623
 624 struct afb_stub_ws *afb_stub_ws_create_client(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset)
 625 {
 626         return afb_stub_ws_create(fdev, apiname, apiset, 1);
 627 }
 628
 629 struct afb_stub_ws *afb_stub_ws_create_server(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset)
 630 {
 631         struct afb_stub_ws *stubws;
 632
 633         stubws = afb_stub_ws_create(fdev, apiname, apiset, 0);
 634         if (stubws) {
 635                 stubws->cred = afb_cred_create_for_socket(fdev_fd(fdev));
 636                 stubws->listener = afb_evt_listener_create(&server_evt_itf, stubws);
 637                 if (stubws->listener != NULL)
 638                         return stubws;
 639                 afb_stub_ws_unref(stubws);
 640         }
 641         return NULL;
 642 }
 643
 644 void afb_stub_ws_unref(struct afb_stub_ws *stubws)
 645 {
 646         if (!__atomic_sub_fetch(&stubws->refcount, 1, __ATOMIC_RELAXED)) {
 647                 drop_all_events(stubws);
 648                 if (stubws->listener)
 649                         afb_evt_listener_unref(stubws->listener);
 650                 release_all_sessions(stubws);
 651                 afb_proto_ws_unref(stubws->proto);
 652                 afb_cred_unref(stubws->cred);
 653                 afb_apiset_unref(stubws->apiset);
 654                 free(stubws);
 655         }
 656 }
 657
 658 void afb_stub_ws_addref(struct afb_stub_ws *stubws)
 659 {
 660         __atomic_add_fetch(&stubws->refcount, 1, __ATOMIC_RELAXED);
 661 }
 662
 663 void afb_stub_ws_set_on_hangup(struct afb_stub_ws *stubws, void (*on_hangup)(struct afb_stub_ws*))
 664 {
 665         stubws->on_hangup = on_hangup;
 666 }
 667
 668 const char *afb_stub_ws_name(struct afb_stub_ws *stubws)
 669 {
 670         return stubws->apiname;
 671 }
 672
 673 struct afb_api_item afb_stub_ws_client_api(struct afb_stub_ws *stubws)
 674 {
 675         struct afb_api_item api;
 676
 677         assert(!stubws->listener); /* check client */
 678         api.closure = stubws;
 679         api.itf = &ws_api_itf;
 680         api.group = NULL;
 681         return api;
 682 }
 683
 684 int afb_stub_ws_client_add(struct afb_stub_ws *stubws, struct afb_apiset *apiset)
 685 {
 686         return afb_apiset_add(apiset, stubws->apiname, afb_stub_ws_client_api(stubws));
 687 }
 688