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         int rc;
 214         struct afb_stub_ws *stubws = closure;
 215
 216         rc = afb_proto_ws_client_call(
 217                         stubws->proto,
 218                         xreq->request.called_verb,
 219                         afb_xreq_json(xreq),
 220                         afb_session_uuid(xreq->context.session),
 221                         xreq,
 222                         xreq_on_behalf_cred_export(xreq));
 223         if (rc >= 0)
 224                 afb_xreq_unhooked_addref(xreq);
 225         else
 226                 afb_xreq_reply(xreq, NULL, "internal", "can't send message");
 227 }
 228
 229 static void client_on_description_cb(void *closure, struct json_object *data)
 230 {
 231         struct client_describe *desc = closure;
 232
 233         desc->result = data;
 234         jobs_leave(desc->jobloop);
 235 }
 236
 237 static void client_send_describe_cb(int signum, void *closure, struct jobloop *jobloop)
 238 {
 239         struct client_describe *desc = closure;
 240
 241         if (signum)
 242                 jobs_leave(jobloop);
 243         else {
 244                 desc->jobloop = jobloop;
 245                 afb_proto_ws_client_describe(desc->stubws->proto, client_on_description_cb, desc);
 246         }
 247 }
 248
 249 /* get the description */
 250 static struct json_object *client_describe_cb(void * closure)
 251 {
 252         struct client_describe desc;
 253
 254         /* synchronous job: send the request and wait its result */
 255         desc.stubws = closure;
 256         desc.result = NULL;
 257         jobs_enter(NULL, 0, client_send_describe_cb, &desc);
 258         return desc.result;
 259 }
 260
 261 /******************* server part: manage events **********************************/
 262
 263 static void server_event_add(void *closure, const char *event, int eventid)
 264 {
 265         struct afb_stub_ws *stubws = closure;
 266
 267         afb_proto_ws_server_event_create(stubws->proto, event, eventid);
 268 }
 269
 270 static void server_event_remove(void *closure, const char *event, int eventid)
 271 {
 272         struct afb_stub_ws *stubws = closure;
 273
 274         afb_proto_ws_server_event_remove(stubws->proto, event, eventid);
 275 }
 276
 277 static void server_event_push(void *closure, const char *event, int eventid, struct json_object *object)
 278 {
 279         struct afb_stub_ws *stubws = closure;
 280
 281         afb_proto_ws_server_event_push(stubws->proto, event, eventid, object);
 282         json_object_put(object);
 283 }
 284
 285 static void server_event_broadcast(void *closure, const char *event, int eventid, struct json_object *object)
 286 {
 287         struct afb_stub_ws *stubws = closure;
 288
 289         afb_proto_ws_server_event_broadcast(stubws->proto, event, object);
 290         json_object_put(object);
 291 }
 292
 293 /*****************************************************/
 294
 295 static void on_reply(void *closure, void *request, struct json_object *object, const char *error, const char *info)
 296 {
 297         struct afb_xreq *xreq = request;
 298
 299         afb_xreq_reply(xreq, object, error, info);
 300         afb_xreq_unhooked_unref(xreq);
 301 }
 302
 303 static void on_event_create(void *closure, const char *event_name, int event_id)
 304 {
 305         struct afb_stub_ws *stubws = closure;
 306         struct client_event *ev;
 307
 308         /* check conflicts */
 309         ev = client_event_search(stubws, event_id, event_name);
 310         if (ev != NULL) {
 311                 ev->refcount++;
 312                 return;
 313         }
 314
 315         /* no conflict, try to add it */
 316         ev = malloc(sizeof *ev);
 317         if (ev != NULL) {
 318                 ev->event = afb_evt_event_x2_create(event_name);
 319                 if (ev->event != NULL) {
 320                         ev->refcount = 1;
 321                         ev->id = event_id;
 322                         ev->next = stubws->events;
 323                         stubws->events = ev;
 324                         return;
 325                 }
 326                 free(ev);
 327         }
 328         ERROR("can't create event %s, out of memory", event_name);
 329 }
 330
 331 static void on_event_remove(void *closure, const char *event_name, int event_id)
 332 {
 333         struct afb_stub_ws *stubws = closure;
 334         struct client_event *ev, **prv;
 335
 336         /* check conflicts */
 337         ev = client_event_search(stubws, event_id, event_name);
 338         if (ev == NULL)
 339                 return;
 340
 341         /* decrease the reference count */
 342         if (--ev->refcount)
 343                 return;
 344
 345         /* unlinks the event */
 346         prv = &stubws->events;
 347         while (*prv != ev)
 348                 prv = &(*prv)->next;
 349         *prv = ev->next;
 350
 351         /* destroys the event */
 352         afb_evt_event_x2_unref(ev->event);
 353         free(ev);
 354 }
 355
 356 static void on_event_subscribe(void *closure, void *request, const char *event_name, int event_id)
 357 {
 358         struct afb_stub_ws *stubws = closure;
 359         struct afb_xreq *xreq = request;
 360         struct client_event *ev;
 361
 362         /* check conflicts */
 363         ev = client_event_search(stubws, event_id, event_name);
 364         if (ev == NULL)
 365                 return;
 366
 367         if (afb_xreq_subscribe(xreq, ev->event) < 0)
 368                 ERROR("can't subscribe: %m");
 369 }
 370
 371 static void on_event_unsubscribe(void *closure, void *request, const char *event_name, int event_id)
 372 {
 373         struct afb_stub_ws *stubws = closure;
 374         struct afb_xreq *xreq = request;
 375         struct client_event *ev;
 376
 377         /* check conflicts */
 378         ev = client_event_search(stubws, event_id, event_name);
 379         if (ev == NULL)
 380                 return;
 381
 382         if (afb_xreq_unsubscribe(xreq, ev->event) < 0)
 383                 ERROR("can't unsubscribe: %m");
 384 }
 385
 386 static void on_event_push(void *closure, const char *event_name, int event_id, struct json_object *data)
 387 {
 388         struct afb_stub_ws *stubws = closure;
 389         struct client_event *ev;
 390
 391         /* check conflicts */
 392         ev = client_event_search(stubws, event_id, event_name);
 393         if (ev)
 394                 afb_evt_event_x2_push(ev->event, data);
 395         else
 396                 ERROR("unreadable push event");
 397 }
 398
 399 static void on_event_broadcast(void *closure, const char *event_name, struct json_object *data)
 400 {
 401         afb_evt_broadcast(event_name, data);
 402 }
 403
 404 /*****************************************************/
 405
 406 static void record_session(struct afb_stub_ws *stubws, struct afb_session *session)
 407 {
 408         struct server_session *s, **prv;
 409
 410         /* search */
 411         prv = &stubws->sessions;
 412         while ((s = *prv)) {
 413                 if (s->session == session)
 414                         return;
 415                 if (afb_session_is_closed(s->session)) {
 416                         *prv = s->next;
 417                         afb_session_unref(s->session);
 418                         free(s);
 419                 }
 420                 else
 421                         prv = &s->next;
 422         }
 423
 424         /* create */
 425         s = malloc(sizeof *s);
 426         if (s) {
 427                 s->session = afb_session_addref(session);
 428                 s->next = stubws->sessions;
 429                 stubws->sessions = s;
 430         }
 431 }
 432
 433 static void release_all_sessions(struct afb_stub_ws *stubws)
 434 {
 435         struct server_session *s, *n;
 436
 437         s = __atomic_exchange_n(&stubws->sessions, NULL, __ATOMIC_RELAXED);
 438         while(s) {
 439                 n = s->next;
 440                 afb_session_unref(s->session);
 441                 free(s);
 442                 s = n;
 443         }
 444 }
 445
 446 /*****************************************************/
 447
 448 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)
 449 {
 450         struct afb_stub_ws *stubws = closure;
 451         struct server_req *wreq;
 452
 453         afb_stub_ws_addref(stubws);
 454
 455         /* create the request */
 456         wreq = malloc(sizeof *wreq);
 457         if (wreq == NULL)
 458                 goto out_of_memory;
 459
 460         afb_xreq_init(&wreq->xreq, &server_req_xreq_itf);
 461         wreq->stubws = stubws;
 462         wreq->call = call;
 463
 464         /* init the context */
 465         if (afb_context_connect(&wreq->xreq.context, sessionid, NULL) < 0)
 466                 goto unconnected;
 467         wreq->xreq.context.validated = 1;
 468         record_session(stubws, wreq->xreq.context.session);
 469         if (wreq->xreq.context.created)
 470                 afb_session_set_autoclose(wreq->xreq.context.session, 1);
 471
 472         /* makes the call */
 473         wreq->xreq.cred = afb_cred_mixed_on_behalf_import(stubws->cred, sessionid, user_creds);
 474         wreq->xreq.request.called_api = stubws->apiname;
 475         wreq->xreq.request.called_verb = verb;
 476         wreq->xreq.json = args;
 477         afb_xreq_process(&wreq->xreq, stubws->apiset);
 478         return;
 479
 480 unconnected:
 481         free(wreq);
 482 out_of_memory:
 483         json_object_put(args);
 484         afb_stub_ws_unref(stubws);
 485         afb_proto_ws_call_reply(call, NULL, "internal-error", NULL);
 486         afb_proto_ws_call_unref(call);
 487 }
 488
 489 static void server_describe_sjob(int signum, void *closure)
 490 {
 491         struct json_object *obj;
 492         struct server_describe *desc = closure;
 493
 494         /* get the description if possible */
 495         obj = !signum ? afb_apiset_describe(desc->stubws->apiset, desc->stubws->apiname) : NULL;
 496
 497         /* send it */
 498         afb_proto_ws_describe_put(desc->describe, obj);
 499         json_object_put(obj);
 500         afb_stub_ws_unref(desc->stubws);
 501 }
 502
 503 static void server_describe_job(int signum, void *closure)
 504 {
 505         server_describe_sjob(signum, closure);
 506         free(closure);
 507 }
 508
 509 static void on_describe(void *closure, struct afb_proto_ws_describe *describe)
 510 {
 511         struct server_describe *desc, sdesc;
 512         struct afb_stub_ws *stubws = closure;
 513
 514         /* allocate (if possible) and init */
 515         desc = malloc(sizeof *desc);
 516         if (desc == NULL)
 517                 desc = &sdesc;
 518         desc->stubws = stubws;
 519         desc->describe = describe;
 520         afb_stub_ws_addref(stubws);
 521
 522         /* process */
 523         if (desc == &sdesc)
 524                 jobs_call(NULL, 0, server_describe_sjob, desc);
 525         else {
 526                 if (jobs_queue(NULL, 0, server_describe_job, desc) < 0)
 527                         jobs_call(NULL, 0, server_describe_job, desc);
 528         }
 529 }
 530
 531 /*****************************************************/
 532
 533 static const struct afb_proto_ws_client_itf client_itf =
 534 {
 535         .on_reply = on_reply,
 536         .on_event_create = on_event_create,
 537         .on_event_remove = on_event_remove,
 538         .on_event_subscribe = on_event_subscribe,
 539         .on_event_unsubscribe = on_event_unsubscribe,
 540         .on_event_push = on_event_push,
 541         .on_event_broadcast = on_event_broadcast,
 542 };
 543
 544 static const struct afb_proto_ws_server_itf server_itf =
 545 {
 546         .on_call = on_call,
 547         .on_describe = on_describe
 548 };
 549
 550 static struct afb_api_itf ws_api_itf = {
 551         .call = client_call_cb,
 552         .describe = client_describe_cb
 553 };
 554
 555 /* the interface for events pushing */
 556 static const struct afb_evt_itf server_evt_itf = {
 557         .broadcast = server_event_broadcast,
 558         .push = server_event_push,
 559         .add = server_event_add,
 560         .remove = server_event_remove
 561 };
 562
 563 /*****************************************************/
 564
 565 static void drop_all_events(struct afb_stub_ws *stubws)
 566 {
 567         struct client_event *ev, *nxt;
 568
 569         ev = stubws->events;
 570         stubws->events = NULL;
 571
 572         while (ev) {
 573                 nxt = ev->next;
 574                 afb_evt_event_x2_unref(ev->event);
 575                 free(ev);
 576                 ev = nxt;
 577         }
 578 }
 579
 580 /* callback when receiving a hangup */
 581 static void on_hangup(void *closure)
 582 {
 583         struct afb_stub_ws *stubws = closure;
 584
 585         afb_stub_ws_addref(stubws);
 586         if (stubws->on_hangup)
 587                 stubws->on_hangup(stubws);
 588
 589         release_all_sessions(stubws);
 590         afb_stub_ws_unref(stubws);
 591 }
 592
 593 static int enqueue_processing(void (*callback)(int signum, void* arg), void *arg)
 594 {
 595         return jobs_queue(NULL, 0, callback, arg);
 596 }
 597
 598 /*****************************************************/
 599
 600 static struct afb_stub_ws *afb_stub_ws_create(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset, int client)
 601 {
 602         struct afb_stub_ws *stubws;
 603
 604         stubws = calloc(1, sizeof *stubws + strlen(apiname));
 605         if (stubws == NULL)
 606                 errno = ENOMEM;
 607         else {
 608                 if (client)
 609                         stubws->proto = afb_proto_ws_create_client(fdev, &client_itf, stubws);
 610                 else
 611                         stubws->proto = afb_proto_ws_create_server(fdev, &server_itf, stubws);
 612
 613                 if (stubws->proto) {
 614                         strcpy(stubws->apiname, apiname);
 615                         stubws->apiset = afb_apiset_addref(apiset);
 616                         stubws->refcount = 1;
 617                         afb_proto_ws_on_hangup(stubws->proto, on_hangup);
 618                         afb_proto_ws_set_queuing(stubws->proto, enqueue_processing);
 619                         return stubws;
 620                 }
 621                 free(stubws);
 622         }
 623         fdev_unref(fdev);
 624         return NULL;
 625 }
 626
 627 struct afb_stub_ws *afb_stub_ws_create_client(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset)
 628 {
 629         return afb_stub_ws_create(fdev, apiname, apiset, 1);
 630 }
 631
 632 struct afb_stub_ws *afb_stub_ws_create_server(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset)
 633 {
 634         struct afb_stub_ws *stubws;
 635
 636         stubws = afb_stub_ws_create(fdev, apiname, apiset, 0);
 637         if (stubws) {
 638                 stubws->cred = afb_cred_create_for_socket(fdev_fd(fdev));
 639                 stubws->listener = afb_evt_listener_create(&server_evt_itf, stubws);
 640                 if (stubws->listener != NULL)
 641                         return stubws;
 642                 afb_stub_ws_unref(stubws);
 643         }
 644         return NULL;
 645 }
 646
 647 void afb_stub_ws_unref(struct afb_stub_ws *stubws)
 648 {
 649         if (!__atomic_sub_fetch(&stubws->refcount, 1, __ATOMIC_RELAXED)) {
 650                 drop_all_events(stubws);
 651                 if (stubws->listener)
 652                         afb_evt_listener_unref(stubws->listener);
 653                 release_all_sessions(stubws);
 654                 afb_proto_ws_unref(stubws->proto);
 655                 afb_cred_unref(stubws->cred);
 656                 afb_apiset_unref(stubws->apiset);
 657                 free(stubws);
 658         }
 659 }
 660
 661 void afb_stub_ws_addref(struct afb_stub_ws *stubws)
 662 {
 663         __atomic_add_fetch(&stubws->refcount, 1, __ATOMIC_RELAXED);
 664 }
 665
 666 void afb_stub_ws_set_on_hangup(struct afb_stub_ws *stubws, void (*on_hangup)(struct afb_stub_ws*))
 667 {
 668         stubws->on_hangup = on_hangup;
 669 }
 670
 671 const char *afb_stub_ws_name(struct afb_stub_ws *stubws)
 672 {
 673         return stubws->apiname;
 674 }
 675
 676 struct afb_api_item afb_stub_ws_client_api(struct afb_stub_ws *stubws)
 677 {
 678         struct afb_api_item api;
 679
 680         assert(!stubws->listener); /* check client */
 681         api.closure = stubws;
 682         api.itf = &ws_api_itf;
 683         api.group = NULL;
 684         return api;
 685 }
 686
 687 int afb_stub_ws_client_add(struct afb_stub_ws *stubws, struct afb_apiset *apiset)
 688 {
 689         return afb_apiset_add(apiset, stubws->apiname, afb_stub_ws_client_api(stubws));
 690 }
 691