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 recording calls on client side
  55  */
  56 struct client_call {
  57         struct client_call *next;       /* the next call */
  58         struct afb_stub_ws *stubws;     /* the stub_ws */
  59         struct afb_xreq *xreq;          /* the request handle */
  60         uint32_t msgid;                 /* the message identifier */
  61 };
  62
  63 /*
  64  * structure for a ws request
  65  */
  66 struct server_req {
  67         struct afb_xreq xreq;           /* the xreq */
  68         struct afb_stub_ws *stubws;     /* the client of the request */
  69         struct afb_proto_ws_call *call; /* the incoming call */
  70 };
  71
  72 /*
  73  * structure for recording events on client side
  74  */
  75 struct client_event
  76 {
  77         struct client_event *next;
  78         struct afb_event_x2 *event;
  79         int id;
  80         int refcount;
  81 };
  82
  83 /*
  84  * structure for recording describe requests
  85  */
  86 struct client_describe
  87 {
  88         struct afb_stub_ws *stubws;
  89         struct jobloop *jobloop;
  90         struct json_object *result;
  91 };
  92
  93 /*
  94  * structure for jobs of describing
  95  */
  96 struct server_describe
  97 {
  98         struct afb_stub_ws *stubws;
  99         struct afb_proto_ws_describe *describe;
 100 };
 101
 102 /*
 103  * structure for recording sessions
 104  */
 105 struct server_session
 106 {
 107         struct server_session *next;
 108         struct afb_session *session;
 109 };
 110
 111 /******************* stub description for client or servers ******************/
 112
 113 struct afb_stub_ws
 114 {
 115         /* count of references */
 116         int refcount;
 117
 118         /* resource control */
 119         pthread_mutex_t mutex;
 120
 121         /* protocol */
 122         struct afb_proto_ws *proto;
 123
 124         /* listener for events (server side) */
 125         struct afb_evt_listener *listener;
 126
 127         /* event replica (client side) */
 128         struct client_event *events;
 129
 130         /* credentials of the client (server side) */
 131         struct afb_cred *cred;
 132
 133         /* sessions (server side) */
 134         struct server_session *sessions;
 135
 136         /* apiset */
 137         struct afb_apiset *apiset;
 138
 139         /* on hangup callback */
 140         void (*on_hangup)(struct afb_stub_ws *);
 141
 142         /* the api name */
 143         char apiname[1];
 144 };
 145
 146 /******************* ws request part for server *****************/
 147
 148 /* decrement the reference count of the request and free/release it on falling to null */
 149 static void server_req_destroy_cb(struct afb_xreq *xreq)
 150 {
 151         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 152
 153         afb_context_disconnect(&wreq->xreq.context);
 154         afb_cred_unref(wreq->xreq.cred);
 155         json_object_put(wreq->xreq.json);
 156         afb_proto_ws_call_unref(wreq->call);
 157         afb_stub_ws_unref(wreq->stubws);
 158         free(wreq);
 159 }
 160
 161 static void server_req_reply_cb(struct afb_xreq *xreq, struct json_object *obj, const char *error, const char *info)
 162 {
 163         int rc;
 164         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 165
 166         rc = afb_proto_ws_call_reply(wreq->call, obj, error, info);
 167         if (rc < 0)
 168                 ERROR("error while sending reply");
 169         json_object_put(obj);
 170 }
 171
 172 static int server_req_subscribe_cb(struct afb_xreq *xreq, struct afb_event_x2 *event)
 173 {
 174         int rc;
 175         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 176
 177         rc = afb_evt_event_x2_add_watch(wreq->stubws->listener, event);
 178         if (rc >= 0)
 179                 rc = afb_proto_ws_call_subscribe(wreq->call,  afb_evt_event_x2_fullname(event), afb_evt_event_x2_id(event));
 180         if (rc < 0)
 181                 ERROR("error while subscribing event");
 182         return rc;
 183 }
 184
 185 static int server_req_unsubscribe_cb(struct afb_xreq *xreq, struct afb_event_x2 *event)
 186 {
 187         int rc, rc2;
 188         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 189
 190         rc = afb_proto_ws_call_unsubscribe(wreq->call,  afb_evt_event_x2_fullname(event), afb_evt_event_x2_id(event));
 191         rc2 = afb_evt_event_x2_remove_watch(wreq->stubws->listener, event);
 192         if (rc >= 0 && rc2 < 0)
 193                 rc = rc2;
 194         if (rc < 0)
 195                 ERROR("error while unsubscribing event");
 196         return rc;
 197 }
 198
 199 static const struct afb_xreq_query_itf server_req_xreq_itf = {
 200         .reply = server_req_reply_cb,
 201         .unref = server_req_destroy_cb,
 202         .subscribe = server_req_subscribe_cb,
 203         .unsubscribe = server_req_unsubscribe_cb
 204 };
 205
 206 /******************* client part **********************************/
 207
 208 /* search the event */
 209 static struct client_event *client_event_search(struct afb_stub_ws *stubws, uint32_t eventid, const char *name)
 210 {
 211         struct client_event *ev;
 212
 213         ev = stubws->events;
 214         while (ev != NULL && (ev->id != eventid || 0 != strcmp(afb_evt_event_x2_fullname(ev->event), name)))
 215                 ev = ev->next;
 216
 217         return ev;
 218 }
 219
 220 /* on call, propagate it to the ws service */
 221 static void client_call_cb(void * closure, struct afb_xreq *xreq)
 222 {
 223         struct afb_stub_ws *stubws = closure;
 224
 225         afb_proto_ws_client_call(
 226                         stubws->proto,
 227                         xreq->request.called_verb,
 228                         afb_xreq_json(xreq),
 229                         afb_session_uuid(xreq->context.session),
 230                         xreq,
 231                         xreq_on_behalf_cred_export(xreq));
 232         afb_xreq_unhooked_addref(xreq);
 233 }
 234
 235 static void client_on_description_cb(void *closure, struct json_object *data)
 236 {
 237         struct client_describe *desc = closure;
 238
 239         desc->result = data;
 240         jobs_leave(desc->jobloop);
 241 }
 242
 243 static void client_send_describe_cb(int signum, void *closure, struct jobloop *jobloop)
 244 {
 245         struct client_describe *desc = closure;
 246
 247         if (signum)
 248                 jobs_leave(jobloop);
 249         else {
 250                 desc->jobloop = jobloop;
 251                 afb_proto_ws_client_describe(desc->stubws->proto, client_on_description_cb, desc);
 252         }
 253 }
 254
 255 /* get the description */
 256 static struct json_object *client_describe_cb(void * closure)
 257 {
 258         struct client_describe desc;
 259
 260         /* synchronous job: send the request and wait its result */
 261         desc.stubws = closure;
 262         desc.result = NULL;
 263         jobs_enter(NULL, 0, client_send_describe_cb, &desc);
 264         return desc.result;
 265 }
 266
 267 /******************* server part: manage events **********************************/
 268
 269 static void server_event_add(void *closure, const char *event, int eventid)
 270 {
 271         struct afb_stub_ws *stubws = closure;
 272
 273         afb_proto_ws_server_event_create(stubws->proto, event, eventid);
 274 }
 275
 276 static void server_event_remove(void *closure, const char *event, int eventid)
 277 {
 278         struct afb_stub_ws *stubws = closure;
 279
 280         afb_proto_ws_server_event_remove(stubws->proto, event, eventid);
 281 }
 282
 283 static void server_event_push(void *closure, const char *event, int eventid, struct json_object *object)
 284 {
 285         struct afb_stub_ws *stubws = closure;
 286
 287         afb_proto_ws_server_event_push(stubws->proto, event, eventid, object);
 288         json_object_put(object);
 289 }
 290
 291 static void server_event_broadcast(void *closure, const char *event, int eventid, struct json_object *object)
 292 {
 293         struct afb_stub_ws *stubws = closure;
 294
 295         afb_proto_ws_server_event_broadcast(stubws->proto, event, object);
 296         json_object_put(object);
 297 }
 298
 299 /*****************************************************/
 300
 301 static void on_reply(void *closure, void *request, struct json_object *object, const char *error, const char *info)
 302 {
 303         struct afb_xreq *xreq = request;
 304
 305         afb_xreq_reply(xreq, object, error, info);
 306         afb_xreq_unhooked_unref(xreq);
 307 }
 308
 309 static void on_event_create(void *closure, const char *event_name, int event_id)
 310 {
 311         struct afb_stub_ws *stubws = closure;
 312         struct client_event *ev;
 313
 314         /* check conflicts */
 315         ev = client_event_search(stubws, event_id, event_name);
 316         if (ev != NULL) {
 317                 ev->refcount++;
 318                 return;
 319         }
 320
 321         /* no conflict, try to add it */
 322         ev = malloc(sizeof *ev);
 323         if (ev != NULL) {
 324                 ev->event = afb_evt_event_x2_create(event_name);
 325                 if (ev->event != NULL) {
 326                         ev->refcount = 1;
 327                         ev->id = event_id;
 328                         ev->next = stubws->events;
 329                         stubws->events = ev;
 330                         return;
 331                 }
 332                 free(ev);
 333         }
 334         ERROR("can't create event %s, out of memory", event_name);
 335 }
 336
 337 static void on_event_remove(void *closure, const char *event_name, int event_id)
 338 {
 339         struct afb_stub_ws *stubws = closure;
 340         struct client_event *ev, **prv;
 341
 342         /* check conflicts */
 343         ev = client_event_search(stubws, event_id, event_name);
 344         if (ev == NULL)
 345                 return;
 346
 347         /* decrease the reference count */
 348         if (--ev->refcount)
 349                 return;
 350
 351         /* unlinks the event */
 352         prv = &stubws->events;
 353         while (*prv != ev)
 354                 prv = &(*prv)->next;
 355         *prv = ev->next;
 356
 357         /* destroys the event */
 358         afb_evt_event_x2_unref(ev->event);
 359         free(ev);
 360 }
 361
 362 static void on_event_subscribe(void *closure, void *request, const char *event_name, int event_id)
 363 {
 364         struct afb_stub_ws *stubws = closure;
 365         struct afb_xreq *xreq = request;
 366         struct client_event *ev;
 367
 368         /* check conflicts */
 369         ev = client_event_search(stubws, event_id, event_name);
 370         if (ev == NULL)
 371                 return;
 372
 373         if (afb_xreq_subscribe(xreq, ev->event) < 0)
 374                 ERROR("can't subscribe: %m");
 375 }
 376
 377 static void on_event_unsubscribe(void *closure, void *request, const char *event_name, int event_id)
 378 {
 379         struct afb_stub_ws *stubws = closure;
 380         struct afb_xreq *xreq = request;
 381         struct client_event *ev;
 382
 383         /* check conflicts */
 384         ev = client_event_search(stubws, event_id, event_name);
 385         if (ev == NULL)
 386                 return;
 387
 388         if (afb_xreq_unsubscribe(xreq, ev->event) < 0)
 389                 ERROR("can't unsubscribe: %m");
 390 }
 391
 392 static void on_event_push(void *closure, const char *event_name, int event_id, struct json_object *data)
 393 {
 394         struct afb_stub_ws *stubws = closure;
 395         struct client_event *ev;
 396
 397         /* check conflicts */
 398         ev = client_event_search(stubws, event_id, event_name);
 399         if (ev)
 400                 afb_evt_event_x2_push(ev->event, data);
 401         else
 402                 ERROR("unreadable push event");
 403 }
 404
 405 static void on_event_broadcast(void *closure, const char *event_name, struct json_object *data)
 406 {
 407         afb_evt_broadcast(event_name, data);
 408 }
 409
 410 /*****************************************************/
 411
 412 static void record_session(struct afb_stub_ws *stubws, struct afb_session *session)
 413 {
 414         struct server_session *s, **prv;
 415
 416         /* search */
 417         prv = &stubws->sessions;
 418         while ((s = *prv)) {
 419                 if (s->session == session)
 420                         return;
 421                 if (afb_session_is_closed(s->session)) {
 422                         *prv = s->next;
 423                         afb_session_unref(s->session);
 424                         free(s);
 425                 }
 426                 else
 427                         prv = &s->next;
 428         }
 429
 430         /* create */
 431         s = malloc(sizeof *s);
 432         if (s) {
 433                 s->session = afb_session_addref(session);
 434                 s->next = stubws->sessions;
 435                 stubws->sessions = s;
 436         }
 437 }
 438
 439 static void release_all_sessions(struct afb_stub_ws *stubws)
 440 {
 441         struct server_session *s, *n;
 442
 443         s = stubws->sessions;
 444         stubws->sessions = NULL;
 445         while(s) {
 446                 n = s->next;
 447                 afb_session_unref(s->session);
 448                 free(s);
 449                 s = n;
 450         }
 451 }
 452
 453 /*****************************************************/
 454
 455 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)
 456 {
 457         struct afb_stub_ws *stubws = closure;
 458         struct server_req *wreq;
 459
 460         afb_stub_ws_addref(stubws);
 461
 462         /* create the request */
 463         wreq = malloc(sizeof *wreq);
 464         if (wreq == NULL)
 465                 goto out_of_memory;
 466
 467         afb_xreq_init(&wreq->xreq, &server_req_xreq_itf);
 468         wreq->stubws = stubws;
 469         wreq->call = call;
 470
 471         /* init the context */
 472         if (afb_context_connect(&wreq->xreq.context, sessionid, NULL) < 0)
 473                 goto unconnected;
 474         wreq->xreq.context.validated = 1;
 475         record_session(stubws, wreq->xreq.context.session);
 476         if (wreq->xreq.context.created)
 477                 afb_session_set_autoclose(wreq->xreq.context.session, 1);
 478
 479         /* makes the call */
 480         wreq->xreq.cred = afb_cred_mixed_on_behalf_import(stubws->cred, sessionid, user_creds);
 481         wreq->xreq.request.called_api = stubws->apiname;
 482         wreq->xreq.request.called_verb = verb;
 483         wreq->xreq.json = args;
 484         afb_xreq_process(&wreq->xreq, stubws->apiset);
 485         return;
 486
 487 unconnected:
 488         free(wreq);
 489 out_of_memory:
 490         json_object_put(args);
 491         afb_stub_ws_unref(stubws);
 492         afb_proto_ws_call_reply(call, NULL, "internal-error", NULL);
 493         afb_proto_ws_call_unref(call);
 494 }
 495
 496 static void server_describe_sjob(int signum, void *closure)
 497 {
 498         struct json_object *obj;
 499         struct server_describe *desc = closure;
 500
 501         /* get the description if possible */
 502         obj = !signum ? afb_apiset_describe(desc->stubws->apiset, desc->stubws->apiname) : NULL;
 503
 504         /* send it */
 505         afb_proto_ws_describe_put(desc->describe, obj);
 506         json_object_put(obj);
 507         afb_stub_ws_unref(desc->stubws);
 508 }
 509
 510 static void server_describe_job(int signum, void *closure)
 511 {
 512         server_describe_sjob(signum, closure);
 513         free(closure);
 514 }
 515
 516 static void on_describe(void *closure, struct afb_proto_ws_describe *describe)
 517 {
 518         struct server_describe *desc, sdesc;
 519         struct afb_stub_ws *stubws = closure;
 520
 521         /* allocate (if possible) and init */
 522         desc = malloc(sizeof *desc);
 523         if (desc == NULL)
 524                 desc = &sdesc;
 525         desc->stubws = stubws;
 526         desc->describe = describe;
 527         afb_stub_ws_addref(stubws);
 528
 529         /* process */
 530         if (desc == &sdesc)
 531                 jobs_call(NULL, 0, server_describe_sjob, desc);
 532         else {
 533                 if (jobs_queue(NULL, 0, server_describe_job, desc) < 0)
 534                         jobs_call(NULL, 0, server_describe_job, desc);
 535         }
 536 }
 537
 538 /*****************************************************/
 539
 540 static const struct afb_proto_ws_client_itf client_itf =
 541 {
 542         .on_reply = on_reply,
 543         .on_event_create = on_event_create,
 544         .on_event_remove = on_event_remove,
 545         .on_event_subscribe = on_event_subscribe,
 546         .on_event_unsubscribe = on_event_unsubscribe,
 547         .on_event_push = on_event_push,
 548         .on_event_broadcast = on_event_broadcast,
 549 };
 550
 551 static const struct afb_proto_ws_server_itf server_itf =
 552 {
 553         .on_call = on_call,
 554         .on_describe = on_describe
 555 };
 556
 557 static struct afb_api_itf ws_api_itf = {
 558         .call = client_call_cb,
 559         .describe = client_describe_cb
 560 };
 561
 562 /* the interface for events pushing */
 563 static const struct afb_evt_itf server_evt_itf = {
 564         .broadcast = server_event_broadcast,
 565         .push = server_event_push,
 566         .add = server_event_add,
 567         .remove = server_event_remove
 568 };
 569
 570 /*****************************************************/
 571
 572 static void drop_all_events(struct afb_stub_ws *stubws)
 573 {
 574         struct client_event *ev, *nxt;
 575
 576         ev = stubws->events;
 577         stubws->events = NULL;
 578
 579         while (ev) {
 580                 nxt = ev->next;
 581                 afb_evt_event_x2_unref(ev->event);
 582                 free(ev);
 583                 ev = nxt;
 584         }
 585 }
 586
 587 /* callback when receiving a hangup */
 588 static void on_hangup(void *closure)
 589 {
 590         struct afb_stub_ws *stubws = closure;
 591
 592         afb_stub_ws_addref(stubws);
 593         if (stubws->on_hangup)
 594                 stubws->on_hangup(stubws);
 595
 596         release_all_sessions(stubws);
 597         afb_stub_ws_unref(stubws);
 598 }
 599
 600 static int enqueue_processing(void (*callback)(int signum, void* arg), void *arg)
 601 {
 602         return jobs_queue(NULL, 0, callback, arg);
 603 }
 604
 605 /*****************************************************/
 606
 607 static struct afb_stub_ws *afb_stub_ws_create(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset, int client)
 608 {
 609         struct afb_stub_ws *stubws;
 610
 611         stubws = calloc(1, sizeof *stubws + strlen(apiname));
 612         if (stubws == NULL)
 613                 errno = ENOMEM;
 614         else {
 615                 if (client)
 616                         stubws->proto = afb_proto_ws_create_client(fdev, &client_itf, stubws);
 617                 else
 618                         stubws->proto = afb_proto_ws_create_server(fdev, &server_itf, stubws);
 619
 620                 if (stubws->proto) {
 621                         strcpy(stubws->apiname, apiname);
 622                         stubws->apiset = afb_apiset_addref(apiset);
 623                         stubws->refcount = 1;
 624                         afb_proto_ws_on_hangup(stubws->proto, on_hangup);
 625                         afb_proto_ws_set_queuing(stubws->proto, enqueue_processing);
 626                         return stubws;
 627                 }
 628                 free(stubws);
 629         }
 630         fdev_unref(fdev);
 631         return NULL;
 632 }
 633
 634 struct afb_stub_ws *afb_stub_ws_create_client(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset)
 635 {
 636         return afb_stub_ws_create(fdev, apiname, apiset, 1);
 637 }
 638
 639 struct afb_stub_ws *afb_stub_ws_create_server(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset)
 640 {
 641         struct afb_stub_ws *stubws;
 642
 643         stubws = afb_stub_ws_create(fdev, apiname, apiset, 0);
 644         if (stubws) {
 645                 stubws->cred = afb_cred_create_for_socket(fdev_fd(fdev));
 646                 stubws->listener = afb_evt_listener_create(&server_evt_itf, stubws);
 647                 if (stubws->listener != NULL)
 648                         return stubws;
 649                 afb_stub_ws_unref(stubws);
 650         }
 651         return NULL;
 652 }
 653
 654 void afb_stub_ws_unref(struct afb_stub_ws *stubws)
 655 {
 656         if (!__atomic_sub_fetch(&stubws->refcount, 1, __ATOMIC_RELAXED)) {
 657                 drop_all_events(stubws);
 658                 if (stubws->listener)
 659                         afb_evt_listener_unref(stubws->listener);
 660                 release_all_sessions(stubws);
 661                 afb_proto_ws_unref(stubws->proto);
 662                 afb_cred_unref(stubws->cred);
 663                 afb_apiset_unref(stubws->apiset);
 664                 free(stubws);
 665         }
 666 }
 667
 668 void afb_stub_ws_addref(struct afb_stub_ws *stubws)
 669 {
 670         __atomic_add_fetch(&stubws->refcount, 1, __ATOMIC_RELAXED);
 671 }
 672
 673 void afb_stub_ws_on_hangup(struct afb_stub_ws *stubws, void (*on_hangup)(struct afb_stub_ws*))
 674 {
 675         stubws->on_hangup = on_hangup;
 676 }
 677
 678 const char *afb_stub_ws_name(struct afb_stub_ws *stubws)
 679 {
 680         return stubws->apiname;
 681 }
 682
 683 struct afb_api_item afb_stub_ws_client_api(struct afb_stub_ws *stubws)
 684 {
 685         struct afb_api_item api;
 686
 687         assert(!stubws->listener); /* check client */
 688         api.closure = stubws;
 689         api.itf = &ws_api_itf;
 690         api.group = NULL;
 691         return api;
 692 }
 693
 694 int afb_stub_ws_client_add(struct afb_stub_ws *stubws, struct afb_apiset *apiset)
 695 {
 696         return afb_apiset_add(apiset, stubws->apiname, afb_stub_ws_client_api(stubws));
 697 }
 698