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