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 #include <systemd/sd-event.h>
  37
  38 #include <afb/afb-event-itf.h>
  39
  40 #include "afb-common.h"
  41
  42 #include "afb-session.h"
  43 #include "afb-cred.h"
  44 #include "afb-api.h"
  45 #include "afb-apiset.h"
  46 #include "afb-proto-ws.h"
  47 #include "afb-stub-ws.h"
  48 #include "afb-context.h"
  49 #include "afb-evt.h"
  50 #include "afb-xreq.h"
  51 #include "verbose.h"
  52 #include "jobs.h"
  53
  54 struct afb_stub_ws;
  55
  56
  57 /******************* handling subcalls *****************************/
  58
  59 /**
  60  * Structure on server side for recording pending
  61  * subcalls.
  62  */
  63 struct server_subcall
  64 {
  65         struct server_subcall *next;    /**< next subcall for the client */
  66         uint32_t subcallid;             /**< the subcallid */
  67         void (*callback)(void*, int, struct json_object*); /**< callback on completion */
  68         void *closure;                  /**< closure of the callback */
  69 };
  70
  71 /**
  72  * Structure for sending back replies on client side
  73  */
  74 struct client_subcall
  75 {
  76         struct afb_stub_ws *stubws;     /**< stub descriptor */
  77         uint32_t subcallid;             /**< subcallid for the reply */
  78 };
  79
  80 /*
  81  * structure for recording calls on client side
  82  */
  83 struct client_call {
  84         struct client_call *next;       /* the next call */
  85         struct afb_stub_ws *stubws;     /* the stub_ws */
  86         struct afb_xreq *xreq;          /* the request handle */
  87         uint32_t msgid;                 /* the message identifier */
  88 };
  89
  90 /*
  91  * structure for a ws request
  92  */
  93 struct server_req {
  94         struct afb_xreq xreq;           /* the xreq */
  95         struct afb_stub_ws *stubws;     /* the client of the request */
  96         struct afb_proto_ws_call *call; /* the incoming call */
  97 };
  98
  99 /*
 100  * structure for recording events on client side
 101  */
 102 struct client_event
 103 {
 104         struct client_event *next;
 105         struct afb_event event;
 106         int eventid;
 107         int refcount;
 108 };
 109
 110 /*
 111  * structure for recording describe requests
 112  */
 113 struct client_describe
 114 {
 115         struct afb_stub_ws *stubws;
 116         struct jobloop *jobloop;
 117         struct json_object *result;
 118 };
 119
 120 /*
 121  * structure for jobs of describing
 122  */
 123 struct server_describe
 124 {
 125         struct afb_stub_ws *stubws;
 126         struct afb_proto_ws_describe *describe;
 127 };
 128
 129 /******************* stub description for client or servers ******************/
 130
 131 struct afb_stub_ws
 132 {
 133         /* count of references */
 134         int refcount;
 135
 136         /* resource control */
 137         pthread_mutex_t mutex;
 138
 139         /* protocol */
 140         struct afb_proto_ws *proto;
 141
 142         /* listener for events (server side) */
 143         struct afb_evt_listener *listener;
 144
 145         /* event replica (client side) */
 146         struct client_event *events;
 147
 148         /* credentials (server side) */
 149         struct afb_cred *cred;
 150
 151         /* apiset */
 152         struct afb_apiset *apiset;
 153
 154         /* on hangup callback */
 155         void (*on_hangup)(struct afb_stub_ws *);
 156
 157         /* the api name */
 158         char apiname[1];
 159 };
 160
 161 /******************* ws request part for server *****************/
 162
 163 /* decrement the reference count of the request and free/release it on falling to null */
 164 static void server_req_destroy_cb(struct afb_xreq *xreq)
 165 {
 166         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 167
 168         afb_context_disconnect(&wreq->xreq.context);
 169         afb_cred_unref(wreq->xreq.cred);
 170         json_object_put(wreq->xreq.json);
 171         afb_proto_ws_call_unref(wreq->call);
 172         afb_stub_ws_unref(wreq->stubws);
 173         free(wreq);
 174 }
 175
 176 static void server_req_success_cb(struct afb_xreq *xreq, struct json_object *obj, const char *info)
 177 {
 178         int rc;
 179         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 180
 181         rc = afb_proto_ws_call_success(wreq->call, obj, info);
 182         if (rc < 0)
 183                 ERROR("error while sending success");
 184         json_object_put(obj);
 185 }
 186
 187 static void server_req_fail_cb(struct afb_xreq *xreq, const char *status, const char *info)
 188 {
 189         int rc;
 190         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 191
 192         rc = afb_proto_ws_call_fail(wreq->call, status, info);
 193         if (rc < 0)
 194                 ERROR("error while sending fail");
 195 }
 196
 197 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)
 198 {
 199         int rc;
 200         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 201
 202         rc = afb_proto_ws_call_subcall(wreq->call, api, verb, args, callback, cb_closure);
 203         if (rc < 0)
 204                 ERROR("error while sending subcall");
 205 }
 206
 207 static int server_req_subscribe_cb(struct afb_xreq *xreq, struct afb_event event)
 208 {
 209         int rc;
 210         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 211
 212         rc = afb_evt_add_watch(wreq->stubws->listener, event);
 213         if (rc >= 0)
 214                 rc = afb_proto_ws_call_subscribe(wreq->call,  afb_evt_event_name(event), afb_evt_event_id(event));
 215         if (rc < 0)
 216                 ERROR("error while subscribing event");
 217         return rc;
 218 }
 219
 220 static int server_req_unsubscribe_cb(struct afb_xreq *xreq, struct afb_event event)
 221 {
 222         int rc, rc2;
 223         struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
 224
 225         rc = afb_proto_ws_call_unsubscribe(wreq->call,  afb_evt_event_name(event), afb_evt_event_id(event));
 226         rc2 = afb_evt_remove_watch(wreq->stubws->listener, event);
 227         if (rc >= 0 && rc2 < 0)
 228                 rc = rc2;
 229         if (rc < 0)
 230                 ERROR("error while unsubscribing event");
 231         return rc;
 232 }
 233
 234 static const struct afb_xreq_query_itf server_req_xreq_itf = {
 235         .success = server_req_success_cb,
 236         .fail = server_req_fail_cb,
 237         .unref = server_req_destroy_cb,
 238         .subcall = server_req_subcall_cb,
 239         .subscribe = server_req_subscribe_cb,
 240         .unsubscribe = server_req_unsubscribe_cb
 241 };
 242
 243 /******************* client part **********************************/
 244
 245 /* search the event */
 246 static struct client_event *client_event_search(struct afb_stub_ws *stubws, uint32_t eventid, const char *name)
 247 {
 248         struct client_event *ev;
 249
 250         ev = stubws->events;
 251         while (ev != NULL && (ev->eventid != eventid || 0 != strcmp(afb_evt_event_name(ev->event), name)))
 252                 ev = ev->next;
 253
 254         return ev;
 255 }
 256
 257 /* on call, propagate it to the ws service */
 258 static void client_call_cb(void * closure, struct afb_xreq *xreq)
 259 {
 260         struct afb_stub_ws *stubws = closure;
 261
 262         afb_proto_ws_client_call(stubws->proto, xreq->verb, afb_xreq_json(xreq), afb_session_uuid(xreq->context.session), xreq);
 263         afb_xreq_addref(xreq);
 264 }
 265
 266 static void client_on_description_cb(void *closure, struct json_object *data)
 267 {
 268         struct client_describe *desc = closure;
 269
 270         desc->result = data;
 271         jobs_leave(desc->jobloop);
 272 }
 273
 274 static void client_send_describe_cb(int signum, void *closure, struct jobloop *jobloop)
 275 {
 276         struct client_describe *desc = closure;
 277
 278         if (signum)
 279                 jobs_leave(jobloop);
 280         else {
 281                 desc->jobloop = jobloop;
 282                 afb_proto_ws_client_describe(desc->stubws->proto, client_on_description_cb, desc);
 283         }
 284 }
 285
 286 /* get the description */
 287 static struct json_object *client_describe_cb(void * closure)
 288 {
 289         struct client_describe desc;
 290
 291         /* synchronous job: send the request and wait its result */
 292         desc.stubws = closure;
 293         desc.result = NULL;
 294         jobs_enter(NULL, 0, client_send_describe_cb, &desc);
 295         return desc.result;
 296 }
 297
 298 /******************* server part: manage events **********************************/
 299
 300 static void server_event_add(void *closure, const char *event, int eventid)
 301 {
 302         struct afb_stub_ws *stubws = closure;
 303
 304         afb_proto_ws_server_event_create(stubws->proto, event, eventid);
 305 }
 306
 307 static void server_event_remove(void *closure, const char *event, int eventid)
 308 {
 309         struct afb_stub_ws *stubws = closure;
 310
 311         afb_proto_ws_server_event_remove(stubws->proto, event, eventid);
 312 }
 313
 314 static void server_event_push(void *closure, const char *event, int eventid, struct json_object *object)
 315 {
 316         struct afb_stub_ws *stubws = closure;
 317
 318         afb_proto_ws_server_event_push(stubws->proto, event, eventid, object);
 319         json_object_put(object);
 320 }
 321
 322 static void server_event_broadcast(void *closure, const char *event, int eventid, struct json_object *object)
 323 {
 324         struct afb_stub_ws *stubws = closure;
 325
 326         afb_proto_ws_server_event_broadcast(stubws->proto, event, object);
 327         json_object_put(object);
 328 }
 329
 330 /*****************************************************/
 331
 332 static void on_reply_success(void *closure, void *request, struct json_object *result, const char *info)
 333 {
 334         struct afb_xreq *xreq = request;
 335
 336         afb_xreq_success(xreq, result, *info ? info : NULL);
 337         afb_xreq_unref(xreq);
 338 }
 339
 340 static void on_reply_fail(void *closure, void *request, const char *status, const char *info)
 341 {
 342         struct afb_xreq *xreq = request;
 343
 344         afb_xreq_fail(xreq, status, *info ? info : NULL);
 345         afb_xreq_unref(xreq);
 346 }
 347
 348 static void on_event_create(void *closure, const char *event_name, int event_id)
 349 {
 350         struct afb_stub_ws *stubws = closure;
 351         struct client_event *ev;
 352
 353         /* check conflicts */
 354         ev = client_event_search(stubws, event_id, event_name);
 355         if (ev != NULL) {
 356                 ev->refcount++;
 357                 return;
 358         }
 359
 360         /* no conflict, try to add it */
 361         ev = malloc(sizeof *ev);
 362         if (ev != NULL) {
 363                 ev->event = afb_evt_create_event(event_name);
 364                 if (ev->event.closure != NULL) {
 365                         ev->refcount = 1;
 366                         ev->eventid = event_id;
 367                         ev->next = stubws->events;
 368                         stubws->events = ev;
 369                         return;
 370                 }
 371                 free(ev);
 372         }
 373         ERROR("can't create event %s, out of memory", event_name);
 374 }
 375
 376 static void on_event_remove(void *closure, const char *event_name, int event_id)
 377 {
 378         struct afb_stub_ws *stubws = closure;
 379         struct client_event *ev, **prv;
 380
 381         /* check conflicts */
 382         ev = client_event_search(stubws, event_id, event_name);
 383         if (ev == NULL)
 384                 return;
 385
 386         /* decrease the reference count */
 387         if (--ev->refcount)
 388                 return;
 389
 390         /* unlinks the event */
 391         prv = &stubws->events;
 392         while (*prv != ev)
 393                 prv = &(*prv)->next;
 394         *prv = ev->next;
 395
 396         /* destroys the event */
 397         afb_event_drop(ev->event);
 398         free(ev);
 399 }
 400
 401 static void on_event_subscribe(void *closure, void *request, const char *event_name, int event_id)
 402 {
 403         struct afb_stub_ws *stubws = closure;
 404         struct afb_xreq *xreq = request;
 405         struct client_event *ev;
 406
 407         /* check conflicts */
 408         ev = client_event_search(stubws, event_id, event_name);
 409         if (ev == NULL)
 410                 return;
 411
 412         if (afb_xreq_subscribe(xreq, ev->event) < 0)
 413                 ERROR("can't subscribe: %m");
 414 }
 415
 416 static void on_event_unsubscribe(void *closure, void *request, const char *event_name, int event_id)
 417 {
 418         struct afb_stub_ws *stubws = closure;
 419         struct afb_xreq *xreq = request;
 420         struct client_event *ev;
 421
 422         /* check conflicts */
 423         ev = client_event_search(stubws, event_id, event_name);
 424         if (ev == NULL)
 425                 return;
 426
 427         if (afb_xreq_unsubscribe(xreq, ev->event) < 0)
 428                 ERROR("can't unsubscribe: %m");
 429 }
 430
 431 static void on_event_push(void *closure, const char *event_name, int event_id, struct json_object *data)
 432 {
 433         struct afb_stub_ws *stubws = closure;
 434         struct client_event *ev;
 435
 436         /* check conflicts */
 437         ev = client_event_search(stubws, event_id, event_name);
 438         if (ev)
 439                 afb_event_push(ev->event, data);
 440         else
 441                 ERROR("unreadable push event");
 442 }
 443
 444 static void on_event_broadcast(void *closure, const char *event_name, struct json_object *data)
 445 {
 446         afb_evt_broadcast(event_name, data);
 447 }
 448
 449 static void client_subcall_reply_cb(void *closure, int status, json_object *object)
 450 {
 451         struct afb_proto_ws_subcall *subcall = closure;
 452         afb_proto_ws_subcall_reply(subcall, status, object);
 453 }
 454
 455 static void on_subcall(void *closure, struct afb_proto_ws_subcall *subcall, void *request, const char *api, const char *verb, struct json_object *args)
 456 {
 457         struct afb_xreq *xreq = request;
 458
 459         afb_xreq_subcall(xreq, api, verb, args, client_subcall_reply_cb, subcall);
 460 }
 461
 462 /*****************************************************/
 463
 464 static void on_call(void *closure, struct afb_proto_ws_call *call, const char *verb, struct json_object *args, const char *sessionid)
 465 {
 466         struct afb_stub_ws *stubws = closure;
 467         struct server_req *wreq;
 468
 469         afb_stub_ws_addref(stubws);
 470
 471         /* create the request */
 472         wreq = malloc(sizeof *wreq);
 473         if (wreq == NULL)
 474                 goto out_of_memory;
 475
 476         afb_xreq_init(&wreq->xreq, &server_req_xreq_itf);
 477         wreq->stubws = stubws;
 478         wreq->call = call;
 479
 480         /* init the context */
 481         if (afb_context_connect(&wreq->xreq.context, sessionid, NULL) < 0)
 482                 goto unconnected;
 483
 484         /* makes the call */
 485         wreq->xreq.cred = afb_cred_addref(stubws->cred);
 486         wreq->xreq.api = stubws->apiname;
 487         wreq->xreq.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_event_drop(ev->event);
 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(fd, &client_itf, stubws);
 615                 else
 616                         stubws->proto = afb_proto_ws_create_server(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.noconcurrency = 0;
 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