src/afb-stub-ws.c

   1 /*
   2  * Copyright (C) 2015, 2016, 2017 "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.h>
  38
  39 #include "afb-common.h"
  40
  41 #include "afb-session.h"
  42 #include "afb-cred.h"
  43 #include "afb-api.h"
  44 #include "afb-apiset.h"
  45 #include "afb-proto-ws.h"
  46 #include "afb-stub-ws.h"
  47 #include "afb-context.h"
  48 #include "afb-evt.h"
  49 #include "afb-xreq.h"
  50 #include "verbose.h"
  51 #include "jobs.h"
  52
  53 struct afb_stub_ws;
  54
  55
  56 /******************* handling subcalls *****************************/
  57
  58 /**
  59  * Structure on server side for recording pending
  60  * subcalls.
  61  */
  62 struct server_subcall
  63 {
  64         struct server_subcall *next;    /**< next subcall for the client */
  65         uint32_t subcallid;             /**< the subcallid */
  66         void (*callback)(void*, int, struct json_object*); /**< callback on completion */
  67         void *closure;                  /**< closure of the callback */
  68 };
  69
  70 /**
  71  * Structure for sending back replies on client side
  72  */
  73 struct client_subcall
  74 {
  75         struct afb_stub_ws *stubws;     /**< stub descriptor */
  76         uint32_t subcallid;             /**< subcallid for the reply */
  77 };
  78
  79 /*
  80  * structure for recording calls on client side
  81  */
  82 struct client_call {
  83         struct client_call *next;       /* the next call */
  84         struct afb_stub_ws *stubws;     /* the stub_ws */
  85         struct afb_xreq *xreq;          /* the request handle */
  86         uint32_t msgid;                 /* the message identifier */
  87 };
  88
  89 /*
  90  * structure for a ws request
  91  */
  92 struct server_req {
  93         struct afb_xreq xreq;           /* the xreq */
  94         struct afb_stub_ws *stubws;     /* the client of the request */
  95         struct afb_proto_ws_call *call; /* the incoming call */
  96 };
  97
  98 /*
  99  * structure for recording events on client side
 100  */
 101 struct client_event
 102 {
 103         struct client_event *next;
 104         struct afb_eventid *eventid;
 105         int id;
 106         int refcount;
 107 };
 108
 109 /*
 110  * structure for recording describe requests
 111  */
 112 struct client_describe
 113 {
 114         struct afb_stub_ws *stubws;
 115         struct jobloop *jobloop;
 116         struct json_object *result;
 117 };
 118
 119 /*
 120  * structure for jobs of describing
 121  */
 122 struct server_describe
 123 {
 124         struct afb_stub_ws *stubws;
 125         struct afb_proto_ws_describe *describe;
 126 };
 127
 128 /******************* stub description for client or servers ******************/
 129
 130 struct afb_stub_ws
 131 {
 132         /* count of references */
 133         int refcount;
 134
 135         /* resource control */
 136         pthread_mutex_t mutex;
 137
 138         /* protocol */
 139         struct afb_proto_ws *proto;
 140
 141         /* listener for events (server side) */
 142         struct afb_evt_listener *listener;
 143
 144         /* event replica (client side) */
 145         struct client_event *events;
 146
 147         /* credentials (server side) */
 148         struct afb_cred *cred;
 149
 150         /* apiset */
 151         struct afb_apiset *apiset;
 152
 153         /* on hangup callback */
 154         void (*on_hangup)(struct afb_stub_ws *);
 155
 156         /* the api name */
 157         char apiname[1];
 158 };
 159
 160 /******************* ws request part for server *****************/
 161
 162 /* decrement the reference count of the request and free/release it on falling to null */
 163 static void server_req_destroy_cb(struct afb_xreq *xreq)
 164 {
 165         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 166
 167         afb_context_disconnect(&wreq->xreq.context);
 168         afb_cred_unref(wreq->xreq.cred);
 169         json_object_put(wreq->xreq.json);
 170         afb_proto_ws_call_unref(wreq->call);
 171         afb_stub_ws_unref(wreq->stubws);
 172         free(wreq);
 173 }
 174
 175 static void server_req_success_cb(struct afb_xreq *xreq, struct json_object *obj, const char *info)
 176 {
 177         int rc;
 178         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 179
 180         rc = afb_proto_ws_call_success(wreq->call, obj, info);
 181         if (rc < 0)
 182                 ERROR("error while sending success");
 183         json_object_put(obj);
 184 }
 185
 186 static void server_req_fail_cb(struct afb_xreq *xreq, const char *status, const char *info)
 187 {
 188         int rc;
 189         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 190
 191         rc = afb_proto_ws_call_fail(wreq->call, status, info);
 192         if (rc < 0)
 193                 ERROR("error while sending fail");
 194 }
 195
 196 static void server_req_subcall_cb(struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *cb_closure)
 197 {
 198         int rc;
 199         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 200
 201         rc = afb_proto_ws_call_subcall(wreq->call, api, verb, args, callback, cb_closure);
 202         if (rc < 0)
 203                 ERROR("error while sending subcall");
 204 }
 205
 206 static int server_req_subscribe_cb(struct afb_xreq *xreq, struct afb_eventid *event)
 207 {
 208         int rc;
 209         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 210
 211         rc = afb_evt_eventid_add_watch(wreq->stubws->listener, event);
 212         if (rc >= 0)
 213                 rc = afb_proto_ws_call_subscribe(wreq->call,  afb_evt_eventid_fullname(event), afb_evt_eventid_id(event));
 214         if (rc < 0)
 215                 ERROR("error while subscribing event");
 216         return rc;
 217 }
 218
 219 static int server_req_unsubscribe_cb(struct afb_xreq *xreq, struct afb_eventid *event)
 220 {
 221         int rc, rc2;
 222         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 223
 224         rc = afb_proto_ws_call_unsubscribe(wreq->call,  afb_evt_eventid_fullname(event), afb_evt_eventid_id(event));
 225         rc2 = afb_evt_eventid_remove_watch(wreq->stubws->listener, event);
 226         if (rc >= 0 && rc2 < 0)
 227                 rc = rc2;
 228         if (rc < 0)
 229                 ERROR("error while unsubscribing event");
 230         return rc;
 231 }
 232
 233 static const struct afb_xreq_query_itf server_req_xreq_itf = {
 234         .success = server_req_success_cb,
 235         .fail = server_req_fail_cb,
 236         .unref = server_req_destroy_cb,
 237         .subcall = server_req_subcall_cb,
 238         .subscribe = server_req_subscribe_cb,
 239         .unsubscribe = server_req_unsubscribe_cb
 240 };
 241
 242 /******************* client part **********************************/
 243
 244 /* search the event */
 245 static struct client_event *client_event_search(struct afb_stub_ws *stubws, uint32_t eventid, const char *name)
 246 {
 247         struct client_event *ev;
 248
 249         ev = stubws->events;
 250         while (ev != NULL && (ev->id != eventid || 0 != strcmp(afb_evt_eventid_fullname(ev->eventid), name)))
 251                 ev = ev->next;
 252
 253         return ev;
 254 }
 255
 256 /* on call, propagate it to the ws service */
 257 static void client_call_cb(void * closure, struct afb_xreq *xreq)
 258 {
 259         struct afb_stub_ws *stubws = closure;
 260
 261         afb_proto_ws_client_call(stubws->proto, xreq->request.verb, afb_xreq_json(xreq), afb_session_uuid(xreq->context.session), xreq);
 262         afb_xreq_unhooked_addref(xreq);
 263 }
 264
 265 static void client_on_description_cb(void *closure, struct json_object *data)
 266 {
 267         struct client_describe *desc = closure;
 268
 269         desc->result = data;
 270         jobs_leave(desc->jobloop);
 271 }
 272
 273 static void client_send_describe_cb(int signum, void *closure, struct jobloop *jobloop)
 274 {
 275         struct client_describe *desc = closure;
 276
 277         if (signum)
 278                 jobs_leave(jobloop);
 279         else {
 280                 desc->jobloop = jobloop;
 281                 afb_proto_ws_client_describe(desc->stubws->proto, client_on_description_cb, desc);
 282         }
 283 }
 284
 285 /* get the description */
 286 static struct json_object *client_describe_cb(void * closure)
 287 {
 288         struct client_describe desc;
 289
 290         /* synchronous job: send the request and wait its result */
 291         desc.stubws = closure;
 292         desc.result = NULL;
 293         jobs_enter(NULL, 0, client_send_describe_cb, &desc);
 294         return desc.result;
 295 }
 296
 297 /******************* server part: manage events **********************************/
 298
 299 static void server_event_add(void *closure, const char *event, int eventid)
 300 {
 301         struct afb_stub_ws *stubws = closure;
 302
 303         afb_proto_ws_server_event_create(stubws->proto, event, eventid);
 304 }
 305
 306 static void server_event_remove(void *closure, const char *event, int eventid)
 307 {
 308         struct afb_stub_ws *stubws = closure;
 309
 310         afb_proto_ws_server_event_remove(stubws->proto, event, eventid);
 311 }
 312
 313 static void server_event_push(void *closure, const char *event, int eventid, struct json_object *object)
 314 {
 315         struct afb_stub_ws *stubws = closure;
 316
 317         afb_proto_ws_server_event_push(stubws->proto, event, eventid, object);
 318         json_object_put(object);
 319 }
 320
 321 static void server_event_broadcast(void *closure, const char *event, int eventid, struct json_object *object)
 322 {
 323         struct afb_stub_ws *stubws = closure;
 324
 325         afb_proto_ws_server_event_broadcast(stubws->proto, event, object);
 326         json_object_put(object);
 327 }
 328
 329 /*****************************************************/
 330
 331 static void on_reply_success(void *closure, void *request, struct json_object *result, const char *info)
 332 {
 333         struct afb_xreq *xreq = request;
 334
 335         afb_xreq_success(xreq, result, *info ? info : NULL);
 336         afb_xreq_unhooked_unref(xreq);
 337 }
 338
 339 static void on_reply_fail(void *closure, void *request, const char *status, const char *info)
 340 {
 341         struct afb_xreq *xreq = request;
 342
 343         afb_xreq_fail(xreq, status, *info ? info : NULL);
 344         afb_xreq_unhooked_unref(xreq);
 345 }
 346
 347 static void on_event_create(void *closure, const char *event_name, int event_id)
 348 {
 349         struct afb_stub_ws *stubws = closure;
 350         struct client_event *ev;
 351
 352         /* check conflicts */
 353         ev = client_event_search(stubws, event_id, event_name);
 354         if (ev != NULL) {
 355                 ev->refcount++;
 356                 return;
 357         }
 358
 359         /* no conflict, try to add it */
 360         ev = malloc(sizeof *ev);
 361         if (ev != NULL) {
 362                 ev->eventid = afb_evt_eventid_create(event_name);
 363                 if (ev->eventid != NULL) {
 364                         ev->refcount = 1;
 365                         ev->id = event_id;
 366                         ev->next = stubws->events;
 367                         stubws->events = ev;
 368                         return;
 369                 }
 370                 free(ev);
 371         }
 372         ERROR("can't create event %s, out of memory", event_name);
 373 }
 374
 375 static void on_event_remove(void *closure, const char *event_name, int event_id)
 376 {
 377         struct afb_stub_ws *stubws = closure;
 378         struct client_event *ev, **prv;
 379
 380         /* check conflicts */
 381         ev = client_event_search(stubws, event_id, event_name);
 382         if (ev == NULL)
 383                 return;
 384
 385         /* decrease the reference count */
 386         if (--ev->refcount)
 387                 return;
 388
 389         /* unlinks the event */
 390         prv = &stubws->events;
 391         while (*prv != ev)
 392                 prv = &(*prv)->next;
 393         *prv = ev->next;
 394
 395         /* destroys the event */
 396         afb_evt_eventid_unref(ev->eventid);
 397         free(ev);
 398 }
 399
 400 static void on_event_subscribe(void *closure, void *request, const char *event_name, int event_id)
 401 {
 402         struct afb_stub_ws *stubws = closure;
 403         struct afb_xreq *xreq = request;
 404         struct client_event *ev;
 405
 406         /* check conflicts */
 407         ev = client_event_search(stubws, event_id, event_name);
 408         if (ev == NULL)
 409                 return;
 410
 411         if (afb_xreq_subscribe(xreq, ev->eventid) < 0)
 412                 ERROR("can't subscribe: %m");
 413 }
 414
 415 static void on_event_unsubscribe(void *closure, void *request, const char *event_name, int event_id)
 416 {
 417         struct afb_stub_ws *stubws = closure;
 418         struct afb_xreq *xreq = request;
 419         struct client_event *ev;
 420
 421         /* check conflicts */
 422         ev = client_event_search(stubws, event_id, event_name);
 423         if (ev == NULL)
 424                 return;
 425
 426         if (afb_xreq_unsubscribe(xreq, ev->eventid) < 0)
 427                 ERROR("can't unsubscribe: %m");
 428 }
 429
 430 static void on_event_push(void *closure, const char *event_name, int event_id, struct json_object *data)
 431 {
 432         struct afb_stub_ws *stubws = closure;
 433         struct client_event *ev;
 434
 435         /* check conflicts */
 436         ev = client_event_search(stubws, event_id, event_name);
 437         if (ev)
 438                 afb_evt_eventid_push(ev->eventid, data);
 439         else
 440                 ERROR("unreadable push event");
 441 }
 442
 443 static void on_event_broadcast(void *closure, const char *event_name, struct json_object *data)
 444 {
 445         afb_evt_broadcast(event_name, data);
 446 }
 447
 448 static void client_subcall_reply_cb(void *closure, int status, json_object *object, struct afb_request *request)
 449 {
 450         struct afb_proto_ws_subcall *subcall = closure;
 451         afb_proto_ws_subcall_reply(subcall, status, object);
 452 }
 453
 454 static void on_subcall(void *closure, struct afb_proto_ws_subcall *subcall, void *request, const char *api, const char *verb, struct json_object *args)
 455 {
 456         struct afb_xreq *xreq = request;
 457
 458         afb_xreq_subcall(xreq, api, verb, args, client_subcall_reply_cb, subcall);
 459 }
 460
 461 /*****************************************************/
 462
 463 static void on_call(void *closure, struct afb_proto_ws_call *call, const char *verb, struct json_object *args, const char *sessionid)
 464 {
 465         struct afb_stub_ws *stubws = closure;
 466         struct server_req *wreq;
 467
 468         afb_stub_ws_addref(stubws);
 469
 470         /* create the request */
 471         wreq = malloc(sizeof *wreq);
 472         if (wreq == NULL)
 473                 goto out_of_memory;
 474
 475         afb_xreq_init(&wreq->xreq, &server_req_xreq_itf);
 476         wreq->stubws = stubws;
 477         wreq->call = call;
 478
 479         /* init the context */
 480         if (afb_context_connect(&wreq->xreq.context, sessionid, NULL) < 0)
 481                 goto unconnected;
 482         wreq->xreq.context.validated = 1;
 483
 484         /* makes the call */
 485         wreq->xreq.cred = afb_cred_addref(stubws->cred);
 486         wreq->xreq.request.api = stubws->apiname;
 487         wreq->xreq.request.verb = verb;
 488         wreq->xreq.json = args;
 489         afb_xreq_process(&wreq->xreq, stubws->apiset);
 490         return;
 491
 492 unconnected:
 493         free(wreq);
 494 out_of_memory:
 495         json_object_put(args);
 496         afb_stub_ws_unref(stubws);
 497         afb_proto_ws_call_fail(call, "internal-error", NULL);
 498         afb_proto_ws_call_unref(call);
 499 }
 500
 501 static void server_describe_sjob(int signum, void *closure)
 502 {
 503         struct json_object *obj;
 504         struct server_describe *desc = closure;
 505
 506         /* get the description if possible */
 507         obj = !signum ? afb_apiset_describe(desc->stubws->apiset, desc->stubws->apiname) : NULL;
 508
 509         /* send it */
 510         afb_proto_ws_describe_put(desc->describe, obj);
 511         json_object_put(obj);
 512         afb_stub_ws_unref(desc->stubws);
 513 }
 514
 515 static void server_describe_job(int signum, void *closure)
 516 {
 517         server_describe_sjob(signum, closure);
 518         free(closure);
 519 }
 520
 521 static void on_describe(void *closure, struct afb_proto_ws_describe *describe)
 522 {
 523         struct server_describe *desc, sdesc;
 524         struct afb_stub_ws *stubws = closure;
 525
 526         /* allocate (if possible) and init */
 527         desc = malloc(sizeof *desc);
 528         if (desc == NULL)
 529                 desc = &sdesc;
 530         desc->stubws = stubws;
 531         desc->describe = describe;
 532         afb_stub_ws_addref(stubws);
 533
 534         /* process */
 535         if (desc == &sdesc)
 536                 jobs_call(NULL, 0, server_describe_sjob, desc);
 537         else {
 538                 if (jobs_queue(NULL, 0, server_describe_job, desc) < 0)
 539                         jobs_call(NULL, 0, server_describe_job, desc);
 540         }
 541 }
 542
 543 /*****************************************************/
 544
 545 static const struct afb_proto_ws_client_itf client_itf =
 546 {
 547         .on_reply_success = on_reply_success,
 548         .on_reply_fail = on_reply_fail,
 549         .on_event_create = on_event_create,
 550         .on_event_remove = on_event_remove,
 551         .on_event_subscribe = on_event_subscribe,
 552         .on_event_unsubscribe = on_event_unsubscribe,
 553         .on_event_push = on_event_push,
 554         .on_event_broadcast = on_event_broadcast,
 555         .on_subcall = on_subcall
 556 };
 557
 558 static const struct afb_proto_ws_server_itf server_itf =
 559 {
 560         .on_call = on_call,
 561         .on_describe = on_describe
 562 };
 563
 564 static struct afb_api_itf ws_api_itf = {
 565         .call = client_call_cb,
 566         .describe = client_describe_cb
 567 };
 568
 569 /* the interface for events pushing */
 570 static const struct afb_evt_itf server_evt_itf = {
 571         .broadcast = server_event_broadcast,
 572         .push = server_event_push,
 573         .add = server_event_add,
 574         .remove = server_event_remove
 575 };
 576
 577 /*****************************************************/
 578
 579 static void drop_all_events(struct afb_stub_ws *stubws)
 580 {
 581         struct client_event *ev, *nxt;
 582
 583         ev = stubws->events;
 584         stubws->events = NULL;
 585
 586         while (ev) {
 587                 nxt = ev->next;
 588                 afb_evt_eventid_unref(ev->eventid);
 589                 free(ev);
 590                 ev = nxt;
 591         }
 592 }
 593
 594 /* callback when receiving a hangup */
 595 static void on_hangup(void *closure)
 596 {
 597         struct afb_stub_ws *stubws = closure;
 598
 599         if (stubws->on_hangup)
 600                 stubws->on_hangup(stubws);
 601 }
 602
 603 /*****************************************************/
 604
 605 static struct afb_stub_ws *afb_stub_ws_create(int fd, const char *apiname, struct afb_apiset *apiset, int client)
 606 {
 607         struct afb_stub_ws *stubws;
 608
 609         stubws = calloc(1, sizeof *stubws + strlen(apiname));
 610         if (stubws == NULL)
 611                 errno = ENOMEM;
 612         else {
 613                 if (client)
 614                         stubws->proto = afb_proto_ws_create_client(afb_common_get_event_loop(), fd, &client_itf, stubws);
 615                 else
 616                         stubws->proto = afb_proto_ws_create_server(afb_common_get_event_loop(), fd, &server_itf, stubws);
 617                 if (stubws->proto != NULL) {
 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         return NULL;
 627 }
 628
 629 struct afb_stub_ws *afb_stub_ws_create_client(int fd, const char *apiname, struct afb_apiset *apiset)
 630 {
 631         return afb_stub_ws_create(fd, apiname, apiset, 1);
 632 }
 633
 634 struct afb_stub_ws *afb_stub_ws_create_server(int fd, const char *apiname, struct afb_apiset *apiset)
 635 {
 636         struct afb_stub_ws *stubws;
 637
 638         stubws = afb_stub_ws_create(fd, apiname, apiset, 0);
 639         if (stubws) {
 640                 stubws->cred = afb_cred_create_for_socket(fd);
 641                 stubws->listener = afb_evt_listener_create(&server_evt_itf, stubws);
 642                 if (stubws->listener != NULL)
 643                         return stubws;
 644                 afb_stub_ws_unref(stubws);
 645         }
 646         return NULL;
 647 }
 648
 649 void afb_stub_ws_unref(struct afb_stub_ws *stubws)
 650 {
 651         if (!__atomic_sub_fetch(&stubws->refcount, 1, __ATOMIC_RELAXED)) {
 652                 drop_all_events(stubws);
 653                 afb_evt_listener_unref(stubws->listener);
 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_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 afb_stub_ws_client_api(struct afb_stub_ws *stubws)
 677 {
 678         struct afb_api 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