src/afb-proto-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-ws.h"
  38 #include "afb-msg-json.h"
  39 #include "afb-proto-ws.h"
  40
  41 struct afb_proto_ws;
  42
  43 /******** implementation of internal binder protocol per api **************/
  44 /*
  45
  46 This protocol is asymetric: there is a client and a server
  47
  48 The client can require the following actions:
  49
  50   - call a verb
  51
  52   - ask for description
  53
  54 The server must reply to the previous actions by
  55
  56   - answering success or failure of the call
  57
  58   - answering the required description
  59
  60 The server can also within the context of a call
  61
  62   - make a subcall
  63
  64   - subscribe or unsubscribe an event
  65
  66 For the purpose of handling events the server can:
  67
  68   - create/destroy an event
  69
  70   - push or brodcast data as an event
  71
  72 */
  73 /************** constants for protocol definition *************************/
  74
  75 #define CHAR_FOR_CALL             'C'
  76 #define CHAR_FOR_ANSWER_SUCCESS   'T'
  77 #define CHAR_FOR_ANSWER_FAIL      'F'
  78 #define CHAR_FOR_EVT_BROADCAST    '*'
  79 #define CHAR_FOR_EVT_ADD          '+'
  80 #define CHAR_FOR_EVT_DEL          '-'
  81 #define CHAR_FOR_EVT_PUSH         '!'
  82 #define CHAR_FOR_EVT_SUBSCRIBE    'S'
  83 #define CHAR_FOR_EVT_UNSUBSCRIBE  'U'
  84 #define CHAR_FOR_SUBCALL_CALL     'B'
  85 #define CHAR_FOR_SUBCALL_REPLY    'R'
  86 #define CHAR_FOR_DESCRIBE         'D'
  87 #define CHAR_FOR_DESCRIPTION      'd'
  88
  89 /******************* handling subcalls *****************************/
  90
  91 /**
  92  * Structure on server side for recording pending
  93  * subcalls.
  94  */
  95 struct server_subcall
  96 {
  97         struct server_subcall *next;    /**< next subcall for the client */
  98         uint32_t subcallid;             /**< the subcallid */
  99         void (*callback)(void*, int, struct json_object*); /**< callback on completion */
 100         void *closure;                  /**< closure of the callback */
 101 };
 102
 103 /**
 104  * Structure for sending back replies on client side
 105  */
 106 struct afb_proto_ws_subcall
 107 {
 108         struct afb_proto_ws *protows;   /**< proto descriptor */
 109         void *buffer;
 110         uint32_t subcallid;             /**< subcallid for the reply */
 111 };
 112
 113 /*
 114  * structure for recording calls on client side
 115  */
 116 struct client_call {
 117         struct client_call *next;       /* the next call */
 118         struct afb_proto_ws *protows;   /* the proto_ws */
 119         void *request;
 120         uint32_t callid;                /* the message identifier */
 121 };
 122
 123 /*
 124  * structure for a ws request
 125  */
 126 struct afb_proto_ws_call {
 127         struct client_call *next;       /* the next call */
 128         struct afb_proto_ws *protows;   /* the client of the request */
 129         uint32_t refcount;              /* reference count */
 130         uint32_t callid;                /* the incoming request callid */
 131         char *buffer;                   /* the incoming buffer */
 132 };
 133
 134 /*
 135  * structure for recording describe requests
 136  */
 137 struct client_describe
 138 {
 139         struct client_describe *next;
 140         struct afb_proto_ws *protows;
 141         void (*callback)(void*, struct json_object*);
 142         void *closure;
 143         uint32_t descid;
 144 };
 145
 146 /*
 147  * structure for jobs of describing
 148  */
 149 struct afb_proto_ws_describe
 150 {
 151         struct afb_proto_ws *protows;
 152         uint32_t descid;
 153 };
 154
 155 /******************* proto description for client or servers ******************/
 156
 157 struct afb_proto_ws
 158 {
 159         /* count of references */
 160         int refcount;
 161
 162         /* file descriptor */
 163         int fd;
 164
 165         /* resource control */
 166         pthread_mutex_t mutex;
 167
 168         /* websocket */
 169         struct afb_ws *ws;
 170
 171         /* the client closure */
 172         void *closure;
 173
 174         /* the client side interface */
 175         const struct afb_proto_ws_client_itf *client_itf;
 176
 177         /* the server side interface */
 178         const struct afb_proto_ws_server_itf *server_itf;
 179
 180         /* emitted calls (client side) */
 181         struct client_call *calls;
 182
 183         /* pending subcalls (server side) */
 184         struct server_subcall *subcalls;
 185
 186         /* pending description (client side) */
 187         struct client_describe *describes;
 188
 189         /* on hangup callback */
 190         void (*on_hangup)(void *closure);
 191 };
 192
 193 /******************* common useful tools **********************************/
 194
 195 /**
 196  * translate a pointer to some integer
 197  * @param ptr the pointer to translate
 198  * @return an integer
 199  */
 200 static inline uint32_t ptr2id(void *ptr)
 201 {
 202         return (uint32_t)(((intptr_t)ptr) >> 6);
 203 }
 204
 205 /******************* serialisation part **********************************/
 206
 207 struct readbuf
 208 {
 209         char *base, *head, *end;
 210 };
 211
 212 #define WRITEBUF_COUNT_MAX  32
 213 struct writebuf
 214 {
 215         struct iovec iovec[WRITEBUF_COUNT_MAX];
 216         uint32_t uints[WRITEBUF_COUNT_MAX];
 217         int count;
 218 };
 219
 220 static char *readbuf_get(struct readbuf *rb, uint32_t length)
 221 {
 222         char *before = rb->head;
 223         char *after = before + length;
 224         if (after > rb->end)
 225                 return 0;
 226         rb->head = after;
 227         return before;
 228 }
 229
 230 static int readbuf_char(struct readbuf *rb, char *value)
 231 {
 232         if (rb->head >= rb->end)
 233                 return 0;
 234         *value = *rb->head++;
 235         return 1;
 236 }
 237
 238 static int readbuf_uint32(struct readbuf *rb, uint32_t *value)
 239 {
 240         char *after = rb->head + sizeof *value;
 241         if (after > rb->end)
 242                 return 0;
 243         memcpy(value, rb->head, sizeof *value);
 244         rb->head = after;
 245         *value = le32toh(*value);
 246         return 1;
 247 }
 248
 249 static int readbuf_string(struct readbuf *rb, const char **value, size_t *length)
 250 {
 251         uint32_t len;
 252         if (!readbuf_uint32(rb, &len) || !len)
 253                 return 0;
 254         if (length)
 255                 *length = (size_t)(len - 1);
 256         return (*value = readbuf_get(rb, len)) != NULL &&  rb->head[-1] == 0;
 257 }
 258
 259 static int readbuf_object(struct readbuf *rb, struct json_object **object)
 260 {
 261         const char *string;
 262         struct json_object *o;
 263         int rc = readbuf_string(rb, &string, NULL);
 264         if (rc) {
 265                 o = json_tokener_parse(string);
 266                 if (o == NULL && strcmp(string, "null"))
 267                         o = json_object_new_string(string);
 268                 *object = o;
 269         }
 270         return rc;
 271 }
 272
 273 static int writebuf_put(struct writebuf *wb, const void *value, size_t length)
 274 {
 275         int i = wb->count;
 276         if (i == WRITEBUF_COUNT_MAX)
 277                 return 0;
 278         wb->iovec[i].iov_base = (void*)value;
 279         wb->iovec[i].iov_len = length;
 280         wb->count = i + 1;
 281         return 1;
 282 }
 283
 284 static int writebuf_char(struct writebuf *wb, char value)
 285 {
 286         int i = wb->count;
 287         if (i == WRITEBUF_COUNT_MAX)
 288                 return 0;
 289         *(char*)&wb->uints[i] = value;
 290         wb->iovec[i].iov_base = &wb->uints[i];
 291         wb->iovec[i].iov_len = 1;
 292         wb->count = i + 1;
 293         return 1;
 294 }
 295
 296 static int writebuf_uint32(struct writebuf *wb, uint32_t value)
 297 {
 298         int i = wb->count;
 299         if (i == WRITEBUF_COUNT_MAX)
 300                 return 0;
 301         wb->uints[i] = htole32(value);
 302         wb->iovec[i].iov_base = &wb->uints[i];
 303         wb->iovec[i].iov_len = sizeof wb->uints[i];
 304         wb->count = i + 1;
 305         return 1;
 306 }
 307
 308 static int writebuf_string_length(struct writebuf *wb, const char *value, size_t length)
 309 {
 310         uint32_t len = (uint32_t)++length;
 311         return (size_t)len == length && len && writebuf_uint32(wb, len) && writebuf_put(wb, value, length);
 312 }
 313
 314 static int writebuf_string(struct writebuf *wb, const char *value)
 315 {
 316         return writebuf_string_length(wb, value, strlen(value));
 317 }
 318
 319 static int writebuf_object(struct writebuf *wb, struct json_object *object)
 320 {
 321         const char *string = json_object_to_json_string_ext(object, JSON_C_TO_STRING_PLAIN);
 322         return string != NULL && writebuf_string(wb, string);
 323 }
 324
 325 /******************* ws request part for server *****************/
 326
 327 void afb_proto_ws_call_addref(struct afb_proto_ws_call *call)
 328 {
 329         __atomic_add_fetch(&call->refcount, 1, __ATOMIC_RELAXED);
 330 }
 331
 332 void afb_proto_ws_call_unref(struct afb_proto_ws_call *call)
 333 {
 334         if (__atomic_sub_fetch(&call->refcount, 1, __ATOMIC_RELAXED))
 335                 return;
 336
 337         afb_proto_ws_unref(call->protows);
 338         free(call->buffer);
 339         free(call);
 340 }
 341
 342 int afb_proto_ws_call_success(struct afb_proto_ws_call *call, struct json_object *obj, const char *info)
 343 {
 344         int rc = -1;
 345         struct writebuf wb = { .count = 0 };
 346         struct afb_proto_ws *protows = call->protows;
 347
 348         if (writebuf_char(&wb, CHAR_FOR_ANSWER_SUCCESS)
 349          && writebuf_uint32(&wb, call->callid)
 350          && writebuf_string(&wb, info ?: "")
 351          && writebuf_object(&wb, obj)) {
 352                 pthread_mutex_lock(&protows->mutex);
 353                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 354                 pthread_mutex_unlock(&protows->mutex);
 355                 if (rc >= 0) {
 356                         rc = 0;
 357                         goto success;
 358                 }
 359         }
 360 success:
 361         return rc;
 362 }
 363
 364 int afb_proto_ws_call_fail(struct afb_proto_ws_call *call, const char *status, const char *info)
 365 {
 366         int rc = -1;
 367         struct writebuf wb = { .count = 0 };
 368         struct afb_proto_ws *protows = call->protows;
 369
 370         if (writebuf_char(&wb, CHAR_FOR_ANSWER_FAIL)
 371          && writebuf_uint32(&wb, call->callid)
 372          && writebuf_string(&wb, status)
 373          && writebuf_string(&wb, info ? : "")) {
 374                 pthread_mutex_lock(&protows->mutex);
 375                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 376                 pthread_mutex_unlock(&protows->mutex);
 377                 if (rc >= 0) {
 378                         rc = 0;
 379                         goto success;
 380                 }
 381         }
 382 success:
 383         return rc;
 384 }
 385
 386 int afb_proto_ws_call_subcall(struct afb_proto_ws_call *call, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *cb_closure)
 387 {
 388         int rc = -1;
 389         struct writebuf wb = { .count = 0 };
 390         struct server_subcall *sc, *osc;
 391         struct afb_proto_ws *protows = call->protows;
 392
 393         sc = malloc(sizeof *sc);
 394         if (!sc)
 395                 errno = ENOMEM;
 396         else {
 397                 sc->callback = callback;
 398                 sc->closure = cb_closure;
 399
 400                 pthread_mutex_lock(&protows->mutex);
 401                 sc->subcallid = ptr2id(sc);
 402                 do {
 403                         sc->subcallid++;
 404                         osc = protows->subcalls;
 405                         while(osc && osc->subcallid != sc->subcallid)
 406                                 osc = osc->next;
 407                 } while (osc);
 408                 sc->next = protows->subcalls;
 409                 protows->subcalls = sc;
 410                 pthread_mutex_unlock(&protows->mutex);
 411
 412                 if (writebuf_char(&wb, CHAR_FOR_SUBCALL_CALL)
 413                  && writebuf_uint32(&wb, sc->subcallid)
 414                  && writebuf_uint32(&wb, call->callid)
 415                  && writebuf_string(&wb, api)
 416                  && writebuf_string(&wb, verb)
 417                  && writebuf_object(&wb, args)) {
 418                         pthread_mutex_lock(&protows->mutex);
 419                         rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 420                         pthread_mutex_unlock(&protows->mutex);
 421                         if (rc >= 0) {
 422                                 rc = 0;
 423                                 goto success;
 424                         }
 425                 }
 426         }
 427 success:
 428         return rc;
 429 }
 430
 431 int afb_proto_ws_call_subscribe(struct afb_proto_ws_call *call, const char *event_name, int event_id)
 432 {
 433         int rc = -1;
 434         struct writebuf wb = { .count = 0 };
 435         struct afb_proto_ws *protows = call->protows;
 436
 437         if (writebuf_char(&wb, CHAR_FOR_EVT_SUBSCRIBE)
 438          && writebuf_uint32(&wb, call->callid)
 439          && writebuf_uint32(&wb, (uint32_t)event_id)
 440          && writebuf_string(&wb, event_name)) {
 441                 pthread_mutex_lock(&protows->mutex);
 442                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 443                 pthread_mutex_unlock(&protows->mutex);
 444                 if (rc >= 0) {
 445                         rc = 0;
 446                         goto success;
 447                 }
 448         }
 449 success:
 450         return rc;
 451 }
 452
 453 int afb_proto_ws_call_unsubscribe(struct afb_proto_ws_call *call, const char *event_name, int event_id)
 454 {
 455         int rc = -1;
 456         struct writebuf wb = { .count = 0 };
 457         struct afb_proto_ws *protows = call->protows;
 458
 459         if (writebuf_char(&wb, CHAR_FOR_EVT_UNSUBSCRIBE)
 460          && writebuf_uint32(&wb, call->callid)
 461          && writebuf_uint32(&wb, (uint32_t)event_id)
 462          && writebuf_string(&wb, event_name)) {
 463                 pthread_mutex_lock(&protows->mutex);
 464                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 465                 pthread_mutex_unlock(&protows->mutex);
 466                 if (rc >= 0) {
 467                         rc = 0;
 468                         goto success;
 469                 }
 470         }
 471 success:
 472         return rc;
 473 }
 474
 475 /******************* client part **********************************/
 476
 477 /* search a memorized call */
 478 static struct client_call *client_call_search_locked(struct afb_proto_ws *protows, uint32_t callid)
 479 {
 480         struct client_call *call;
 481
 482         call = protows->calls;
 483         while (call != NULL && call->callid != callid)
 484                 call = call->next;
 485
 486         return call;
 487 }
 488
 489 static struct client_call *client_call_search_unlocked(struct afb_proto_ws *protows, uint32_t callid)
 490 {
 491         struct client_call *result;
 492
 493         pthread_mutex_lock(&protows->mutex);
 494         result = client_call_search_locked(protows, callid);
 495         pthread_mutex_unlock(&protows->mutex);
 496         return result;
 497 }
 498
 499 /* free and release the memorizing call */
 500 static void client_call_destroy(struct client_call *call)
 501 {
 502         struct client_call **prv;
 503         struct afb_proto_ws *protows = call->protows;
 504
 505         pthread_mutex_lock(&protows->mutex);
 506         prv = &call->protows->calls;
 507         while (*prv != NULL) {
 508                 if (*prv == call) {
 509                         *prv = call->next;
 510                         break;
 511                 }
 512                 prv = &(*prv)->next;
 513         }
 514         pthread_mutex_unlock(&protows->mutex);
 515         free(call);
 516 }
 517
 518 /* get event data from the message */
 519 static int client_msg_event_read(struct readbuf *rb, uint32_t *eventid, const char **name)
 520 {
 521         return readbuf_uint32(rb, eventid) && readbuf_string(rb, name, NULL);
 522 }
 523
 524 /* get event from the message */
 525 static int client_msg_call_get(struct afb_proto_ws *protows, struct readbuf *rb, struct client_call **call)
 526 {
 527         uint32_t callid;
 528
 529         /* get event data from the message */
 530         if (!readbuf_uint32(rb, &callid)) {
 531                 return 0;
 532         }
 533
 534         /* get the call */
 535         *call = client_call_search_unlocked(protows, callid);
 536         if (*call == NULL) {
 537                 return 0;
 538         }
 539
 540         return 1;
 541 }
 542
 543 /* adds an event */
 544 static void client_on_event_create(struct afb_proto_ws *protows, struct readbuf *rb)
 545 {
 546         const char *event_name;
 547         uint32_t event_id;
 548
 549         if (protows->client_itf->on_event_create && client_msg_event_read(rb, &event_id, &event_name))
 550                 protows->client_itf->on_event_create(protows->closure, event_name, (int)event_id);
 551 }
 552
 553 /* removes an event */
 554 static void client_on_event_remove(struct afb_proto_ws *protows, struct readbuf *rb)
 555 {
 556         const char *event_name;
 557         uint32_t event_id;
 558
 559         if (protows->client_itf->on_event_remove && client_msg_event_read(rb, &event_id, &event_name))
 560                 protows->client_itf->on_event_remove(protows->closure, event_name, (int)event_id);
 561 }
 562
 563 /* subscribes an event */
 564 static void client_on_event_subscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 565 {
 566         const char *event_name;
 567         uint32_t event_id;
 568         struct client_call *call;
 569
 570         if (protows->client_itf->on_event_subscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 571                 protows->client_itf->on_event_subscribe(protows->closure, call->request, event_name, (int)event_id);
 572 }
 573
 574 /* unsubscribes an event */
 575 static void client_on_event_unsubscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 576 {
 577         const char *event_name;
 578         uint32_t event_id;
 579         struct client_call *call;
 580
 581         if (protows->client_itf->on_event_unsubscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 582                 protows->client_itf->on_event_unsubscribe(protows->closure, call->request, event_name, (int)event_id);
 583 }
 584
 585 /* receives broadcasted events */
 586 static void client_on_event_broadcast(struct afb_proto_ws *protows, struct readbuf *rb)
 587 {
 588         const char *event_name;
 589         struct json_object *object;
 590
 591         if (protows->client_itf->on_event_broadcast && readbuf_string(rb, &event_name, NULL) && readbuf_object(rb, &object))
 592                 protows->client_itf->on_event_broadcast(protows->closure, event_name, object);
 593 }
 594
 595 /* pushs an event */
 596 static void client_on_event_push(struct afb_proto_ws *protows, struct readbuf *rb)
 597 {
 598         const char *event_name;
 599         uint32_t event_id;
 600         struct json_object *object;
 601
 602         if (protows->client_itf->on_event_push && client_msg_event_read(rb, &event_id, &event_name) && readbuf_object(rb, &object))
 603                 protows->client_itf->on_event_push(protows->closure, event_name, (int)event_id, object);
 604 }
 605
 606 static void client_on_reply_success(struct afb_proto_ws *protows, struct readbuf *rb)
 607 {
 608         struct client_call *call;
 609         struct json_object *object;
 610         const char *info;
 611
 612         if (!client_msg_call_get(protows, rb, &call))
 613                 return;
 614
 615         if (readbuf_string(rb, &info, NULL) && readbuf_object(rb, &object)) {
 616                 protows->client_itf->on_reply_success(protows->closure, call->request, object, info);
 617         } else {
 618                 protows->client_itf->on_reply_fail(protows->closure, call->request, "proto-error", "can't process success");
 619         }
 620         client_call_destroy(call);
 621 }
 622
 623 static void client_on_reply_fail(struct afb_proto_ws *protows, struct readbuf *rb)
 624 {
 625         struct client_call *call;
 626         const char *info, *status;
 627
 628         if (!client_msg_call_get(protows, rb, &call))
 629                 return;
 630
 631
 632         if (readbuf_string(rb, &status, NULL) && readbuf_string(rb, &info, NULL)) {
 633                 protows->client_itf->on_reply_fail(protows->closure, call->request, status, info);
 634         } else {
 635                 protows->client_itf->on_reply_fail(protows->closure, call->request, "proto-error", "can't process fail");
 636         }
 637         client_call_destroy(call);
 638 }
 639
 640 /* send a subcall reply */
 641 static int client_send_subcall_reply(struct afb_proto_ws *protows, uint32_t subcallid, int status, json_object *object)
 642 {
 643         struct writebuf wb = { .count = 0 };
 644         char ie = status < 0;
 645         int rc;
 646
 647         if (writebuf_char(&wb, CHAR_FOR_SUBCALL_REPLY)
 648          && writebuf_uint32(&wb, subcallid)
 649          && writebuf_char(&wb, ie)
 650          && writebuf_object(&wb, object)) {
 651                 pthread_mutex_lock(&protows->mutex);
 652                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 653                 pthread_mutex_unlock(&protows->mutex);
 654                 if (rc >= 0)
 655                         return 0;
 656         }
 657         return -1;
 658 }
 659
 660 /* callback for subcall reply */
 661 int afb_proto_ws_subcall_reply(struct afb_proto_ws_subcall *subcall, int status, struct json_object *result)
 662 {
 663         int rc = client_send_subcall_reply(subcall->protows, subcall->subcallid, status, result);
 664         afb_proto_ws_unref(subcall->protows);
 665         free(subcall->buffer);
 666         free(subcall);
 667         return rc;
 668 }
 669
 670 /* received a subcall request */
 671 static void client_on_subcall(struct afb_proto_ws *protows, struct readbuf *rb)
 672 {
 673         struct afb_proto_ws_subcall *subcall;
 674         struct client_call *call;
 675         const char *api, *verb;
 676         uint32_t subcallid;
 677         struct json_object *object;
 678
 679         /* get the subcallid */
 680         if (!readbuf_uint32(rb, &subcallid))
 681                 return;
 682
 683         /* if not expected drop it */
 684         if (!protows->client_itf->on_subcall)
 685                 goto error;
 686
 687         /* retrieve the message data */
 688         if (!client_msg_call_get(protows, rb, &call))
 689                 goto error;
 690
 691         /* allocation of the subcall */
 692         subcall = malloc(sizeof *subcall);
 693         if (!subcall)
 694                 goto error;
 695
 696         /* make the call */
 697         if (readbuf_string(rb, &api, NULL)
 698          && readbuf_string(rb, &verb, NULL)
 699          && readbuf_object(rb, &object)) {
 700                 afb_proto_ws_addref(protows);
 701                 subcall->protows = protows;
 702                 subcall->subcallid = subcallid;
 703                 subcall->buffer = rb->base;
 704                 rb->base = NULL;
 705                 protows->client_itf->on_subcall(protows->closure, subcall, call->request, api, verb, object);
 706                 return;
 707         }
 708         free(subcall);
 709 error:
 710         client_send_subcall_reply(protows, subcallid, 1, NULL);
 711 }
 712
 713 static void client_on_description(struct afb_proto_ws *protows, struct readbuf *rb)
 714 {
 715         uint32_t descid;
 716         struct client_describe *desc, **prv;
 717         struct json_object *object;
 718
 719         if (readbuf_uint32(rb, &descid)) {
 720                 pthread_mutex_lock(&protows->mutex);
 721                 prv = &protows->describes;
 722                 while ((desc = *prv) && desc->descid != descid)
 723                         prv = &desc->next;
 724                 if (!desc)
 725                         pthread_mutex_unlock(&protows->mutex);
 726                 else {
 727                         *prv = desc->next;
 728                         pthread_mutex_unlock(&protows->mutex);
 729                         if (!readbuf_object(rb, &object))
 730                                 object = NULL;
 731                         desc->callback(desc->closure, object);
 732                         free(desc);
 733                 }
 734         }
 735 }
 736
 737 /* callback when receiving binary data */
 738 static void client_on_binary(void *closure, char *data, size_t size)
 739 {
 740         struct afb_proto_ws *protows;
 741         struct readbuf rb;
 742
 743         rb.base = data;
 744         if (size > 0) {
 745                 rb.head = data;
 746                 rb.end = data + size;
 747                 protows = closure;
 748
 749                 switch (*rb.head++) {
 750                 case CHAR_FOR_ANSWER_SUCCESS: /* success */
 751                         client_on_reply_success(protows, &rb);
 752                         break;
 753                 case CHAR_FOR_ANSWER_FAIL: /* fail */
 754                         client_on_reply_fail(protows, &rb);
 755                         break;
 756                 case CHAR_FOR_EVT_BROADCAST: /* broadcast */
 757                         client_on_event_broadcast(protows, &rb);
 758                         break;
 759                 case CHAR_FOR_EVT_ADD: /* creates the event */
 760                         client_on_event_create(protows, &rb);
 761                         break;
 762                 case CHAR_FOR_EVT_DEL: /* removes the event */
 763                         client_on_event_remove(protows, &rb);
 764                         break;
 765                 case CHAR_FOR_EVT_PUSH: /* pushs the event */
 766                         client_on_event_push(protows, &rb);
 767                         break;
 768                 case CHAR_FOR_EVT_SUBSCRIBE: /* subscribe event for a request */
 769                         client_on_event_subscribe(protows, &rb);
 770                         break;
 771                 case CHAR_FOR_EVT_UNSUBSCRIBE: /* unsubscribe event for a request */
 772                         client_on_event_unsubscribe(protows, &rb);
 773                         break;
 774                 case CHAR_FOR_SUBCALL_CALL: /* subcall */
 775                         client_on_subcall(protows, &rb);
 776                         break;
 777                 case CHAR_FOR_DESCRIPTION: /* description */
 778                         client_on_description(protows, &rb);
 779                         break;
 780                 default: /* unexpected message */
 781                         /* TODO: close the connection */
 782                         break;
 783                 }
 784         }
 785         free(rb.base);
 786 }
 787
 788 int afb_proto_ws_client_call(
 789                 struct afb_proto_ws *protows,
 790                 const char *verb,
 791                 struct json_object *args,
 792                 const char *sessionid,
 793                 void *request
 794 )
 795 {
 796         int rc = -1;
 797         struct client_call *call;
 798         struct writebuf wb = { .count = 0 };
 799
 800         /* allocate call data */
 801         call = malloc(sizeof *call);
 802         if (call == NULL) {
 803                 errno = ENOMEM;
 804                 return -1;
 805         }
 806         call->request = request;
 807
 808         /* init call data */
 809         pthread_mutex_lock(&protows->mutex);
 810         call->callid = ptr2id(call);
 811         while(client_call_search_locked(protows, call->callid) != NULL)
 812                 call->callid++;
 813         call->protows = protows;
 814         call->next = protows->calls;
 815         protows->calls = call;
 816         pthread_mutex_unlock(&protows->mutex);
 817
 818         /* creates the call message */
 819         if (!writebuf_char(&wb, CHAR_FOR_CALL)
 820          || !writebuf_uint32(&wb, call->callid)
 821          || !writebuf_string(&wb, verb)
 822          || !writebuf_string(&wb, sessionid)
 823          || !writebuf_object(&wb, args)) {
 824                 errno = EINVAL;
 825                 goto clean;
 826         }
 827
 828         /* send */
 829         pthread_mutex_lock(&protows->mutex);
 830         rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 831         pthread_mutex_unlock(&protows->mutex);
 832         if (rc >= 0) {
 833                 rc = 0;
 834                 goto end;
 835         }
 836
 837 clean:
 838         client_call_destroy(call);
 839 end:
 840         return rc;
 841 }
 842
 843 /* get the description */
 844 int afb_proto_ws_client_describe(struct afb_proto_ws *protows, void (*callback)(void*, struct json_object*), void *closure)
 845 {
 846         struct client_describe *desc, *d;
 847         struct writebuf wb = { .count = 0 };
 848
 849         desc = malloc(sizeof *desc);
 850         if (!desc) {
 851                 errno = ENOMEM;
 852                 goto error;
 853         }
 854
 855         /* fill in stack the description of the task */
 856         pthread_mutex_lock(&protows->mutex);
 857         desc->descid = ptr2id(desc);
 858         d = protows->describes;
 859         while (d) {
 860                 if (d->descid != desc->descid)
 861                         d = d->next;
 862                 else {
 863                         desc->descid++;
 864                         d = protows->describes;
 865                 }
 866         }
 867         desc->callback = callback;
 868         desc->closure = closure;
 869         desc->protows = protows;
 870         desc->next = protows->describes;
 871         protows->describes = desc;
 872
 873         /* send */
 874         if (writebuf_char(&wb, CHAR_FOR_DESCRIBE)
 875          && writebuf_uint32(&wb, desc->descid)
 876          && afb_ws_binary_v(protows->ws, wb.iovec, wb.count) >= 0) {
 877                 pthread_mutex_unlock(&protows->mutex);
 878                 return 0;
 879         }
 880
 881         d = protows->describes;
 882         if (d == desc)
 883                 protows->describes = desc->next;
 884         else {
 885                 while(d && d->next != desc)
 886                         d = d->next;
 887                 if (d)
 888                         d->next = desc->next;
 889         }
 890         pthread_mutex_unlock(&protows->mutex);
 891         free(desc);
 892 error:
 893         /* TODO? callback(closure, NULL); */
 894         return -1;
 895 }
 896
 897 /******************* client description part for server *****************************/
 898
 899 /* on call, propagate it to the ws service */
 900 static void server_on_call(struct afb_proto_ws *protows, struct readbuf *rb)
 901 {
 902         struct afb_proto_ws_call *call;
 903         const char *uuid, *verb;
 904         uint32_t callid;
 905         size_t lenverb;
 906         struct json_object *object;
 907
 908         afb_proto_ws_addref(protows);
 909
 910         /* reads the call message data */
 911         if (!readbuf_uint32(rb, &callid)
 912          || !readbuf_string(rb, &verb, &lenverb)
 913          || !readbuf_string(rb, &uuid, NULL)
 914          || !readbuf_object(rb, &object))
 915                 goto overflow;
 916
 917         /* create the request */
 918         call = malloc(sizeof *call);
 919         if (call == NULL)
 920                 goto out_of_memory;
 921
 922         call->protows = protows;
 923         call->callid = callid;
 924         call->refcount = 1;
 925         call->buffer = rb->base;
 926         rb->base = NULL; /* don't free the buffer */
 927
 928         protows->server_itf->on_call(protows->closure, call, verb, object, uuid);
 929         return;
 930
 931 out_of_memory:
 932         json_object_put(object);
 933
 934 overflow:
 935         afb_proto_ws_unref(protows);
 936 }
 937
 938 /* on subcall reply */
 939 static void server_on_subcall_reply(struct afb_proto_ws *protows, struct readbuf *rb)
 940 {
 941         char ie;
 942         uint32_t subcallid;
 943         struct json_object *object;
 944         struct server_subcall *sc, **psc;
 945
 946         /* reads the call message data */
 947         if (!readbuf_uint32(rb, &subcallid)
 948          || !readbuf_char(rb, &ie)
 949          || !readbuf_object(rb, &object)) {
 950                 /* TODO bad protocol */
 951                 return;
 952         }
 953
 954         /* search the subcall and unlink it */
 955         pthread_mutex_lock(&protows->mutex);
 956         psc = &protows->subcalls;
 957         while ((sc = *psc) && sc->subcallid != subcallid)
 958                 psc = &sc->next;
 959         if (!sc) {
 960                 pthread_mutex_unlock(&protows->mutex);
 961                 json_object_put(object);
 962                 /* TODO subcall not found */
 963         } else {
 964                 *psc = sc->next;
 965                 pthread_mutex_unlock(&protows->mutex);
 966                 sc->callback(sc->closure, -(int)ie, object);
 967                 free(sc);
 968         }
 969 }
 970
 971 static int server_send_description(struct afb_proto_ws *protows, uint32_t descid, struct json_object *descobj)
 972 {
 973         int rc;
 974         struct writebuf wb = { .count = 0 };
 975
 976         if (writebuf_char(&wb, CHAR_FOR_DESCRIPTION)
 977          && writebuf_uint32(&wb, descid)
 978          && writebuf_object(&wb, descobj)) {
 979                 pthread_mutex_lock(&protows->mutex);
 980                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 981                 pthread_mutex_unlock(&protows->mutex);
 982                 if (rc >= 0)
 983                         return 0;
 984         }
 985         return -1;
 986 }
 987
 988 int afb_proto_ws_describe_put(struct afb_proto_ws_describe *describe, struct json_object *description)
 989 {
 990         int rc = server_send_description(describe->protows, describe->descid, description);
 991         afb_proto_ws_unref(describe->protows);
 992         free(describe);
 993         return rc;
 994 }
 995
 996 /* on describe, propagate it to the ws service */
 997 static void server_on_describe(struct afb_proto_ws *protows, struct readbuf *rb)
 998 {
 999         uint32_t descid;
1000         struct afb_proto_ws_describe *desc;
1001
1002         /* reads the descid */
1003         if (readbuf_uint32(rb, &descid)) {
1004                 if (protows->server_itf->on_describe) {
1005                         /* create asynchronous job */
1006                         desc = malloc(sizeof *desc);
1007                         if (desc) {
1008                                 desc->descid = descid;
1009                                 desc->protows = protows;
1010                                 afb_proto_ws_addref(protows);
1011                                 protows->server_itf->on_describe(protows->closure, desc);
1012                                 return;
1013                         }
1014                 }
1015                 server_send_description(protows, descid, NULL);
1016         }
1017 }
1018
1019 /* callback when receiving binary data */
1020 static void server_on_binary(void *closure, char *data, size_t size)
1021 {
1022         struct afb_proto_ws *protows;
1023         struct readbuf rb;
1024
1025         rb.base = data;
1026         if (size > 0) {
1027                 rb.head = data;
1028                 rb.end = data + size;
1029                 protows = closure;
1030
1031                 switch (*rb.head++) {
1032                 case CHAR_FOR_CALL:
1033                         server_on_call(protows, &rb);
1034                         break;
1035                 case CHAR_FOR_SUBCALL_REPLY:
1036                         server_on_subcall_reply(protows, &rb);
1037                         break;
1038                 case CHAR_FOR_DESCRIBE:
1039                         server_on_describe(protows, &rb);
1040                         break;
1041                 default: /* unexpected message */
1042                         /* TODO: close the connection */
1043                         break;
1044                 }
1045         }
1046         free(rb.base);
1047 }
1048
1049 /******************* server part: manage events **********************************/
1050
1051 static int server_event_send(struct afb_proto_ws *protows, char order, const char *event_name, int event_id, struct json_object *data)
1052 {
1053         struct writebuf wb = { .count = 0 };
1054         int rc;
1055
1056         if (writebuf_char(&wb, order)
1057          && (order == CHAR_FOR_EVT_BROADCAST || writebuf_uint32(&wb, event_id))
1058          && writebuf_string(&wb, event_name)
1059          && (order == CHAR_FOR_EVT_ADD || order == CHAR_FOR_EVT_DEL || writebuf_object(&wb, data))) {
1060                 pthread_mutex_lock(&protows->mutex);
1061                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
1062                 pthread_mutex_unlock(&protows->mutex);
1063                 if (rc >= 0)
1064                         return 0;
1065         }
1066         return -1;
1067 }
1068
1069 int afb_proto_ws_server_event_create(struct afb_proto_ws *protows, const char *event_name, int event_id)
1070 {
1071         return server_event_send(protows, CHAR_FOR_EVT_ADD, event_name, event_id, NULL);
1072 }
1073
1074 int afb_proto_ws_server_event_remove(struct afb_proto_ws *protows, const char *event_name, int event_id)
1075 {
1076         return server_event_send(protows, CHAR_FOR_EVT_DEL, event_name, event_id, NULL);
1077 }
1078
1079 int afb_proto_ws_server_event_push(struct afb_proto_ws *protows, const char *event_name, int event_id, struct json_object *data)
1080 {
1081         return server_event_send(protows, CHAR_FOR_EVT_PUSH, event_name, event_id, data);
1082 }
1083
1084 int afb_proto_ws_server_event_broadcast(struct afb_proto_ws *protows, const char *event_name, struct json_object *data)
1085 {
1086         return server_event_send(protows, CHAR_FOR_EVT_BROADCAST, event_name, 0, data);
1087 }
1088
1089 /*****************************************************/
1090
1091 /* callback when receiving a hangup */
1092 static void on_hangup(void *closure)
1093 {
1094         struct afb_proto_ws *protows = closure;
1095         struct server_subcall *sc, *nsc;
1096         struct client_describe *cd, *ncd;
1097
1098         nsc = protows->subcalls;
1099         while (nsc) {
1100                 sc= nsc;
1101                 nsc = sc->next;
1102                 sc->callback(sc->closure, 1, NULL);
1103                 free(sc);
1104         }
1105
1106         ncd = protows->describes;
1107         while (ncd) {
1108                 cd= ncd;
1109                 ncd = cd->next;
1110                 cd->callback(cd->closure, NULL);
1111                 free(cd);
1112         }
1113
1114         if (protows->fd >= 0) {
1115                 close(protows->fd);
1116                 protows->fd = -1;
1117                 if (protows->on_hangup)
1118                         protows->on_hangup(protows->closure);
1119         }
1120 }
1121
1122 /*****************************************************/
1123
1124 static const struct afb_ws_itf proto_ws_client_ws_itf =
1125 {
1126         .on_close = NULL,
1127         .on_text = NULL,
1128         .on_binary = client_on_binary,
1129         .on_error = NULL,
1130         .on_hangup = on_hangup
1131 };
1132
1133 static const struct afb_ws_itf server_ws_itf =
1134 {
1135         .on_close = NULL,
1136         .on_text = NULL,
1137         .on_binary = server_on_binary,
1138         .on_error = NULL,
1139         .on_hangup = on_hangup
1140 };
1141
1142 /*****************************************************/
1143
1144 static struct afb_proto_ws *afb_proto_ws_create(struct sd_event *eloop, int fd, const struct afb_proto_ws_server_itf *itfs, const struct afb_proto_ws_client_itf *itfc, void *closure, const struct afb_ws_itf *itf)
1145 {
1146         struct afb_proto_ws *protows;
1147
1148         protows = calloc(1, sizeof *protows);
1149         if (protows == NULL)
1150                 errno = ENOMEM;
1151         else {
1152                 fcntl(fd, F_SETFD, FD_CLOEXEC);
1153                 fcntl(fd, F_SETFL, O_NONBLOCK);
1154                 protows->ws = afb_ws_create(eloop, fd, itf, protows);
1155                 if (protows->ws != NULL) {
1156                         protows->fd = fd;
1157                         protows->refcount = 1;
1158                         protows->subcalls = NULL;
1159                         protows->closure = closure;
1160                         protows->server_itf = itfs;
1161                         protows->client_itf = itfc;
1162                         pthread_mutex_init(&protows->mutex, NULL);
1163                         return protows;
1164                 }
1165                 free(protows);
1166         }
1167         return NULL;
1168 }
1169
1170 struct afb_proto_ws *afb_proto_ws_create_client(struct sd_event *eloop, int fd, const struct afb_proto_ws_client_itf *itf, void *closure)
1171 {
1172         return afb_proto_ws_create(eloop, fd, NULL, itf, closure, &proto_ws_client_ws_itf);
1173 }
1174
1175 struct afb_proto_ws *afb_proto_ws_create_server(struct sd_event *eloop, int fd, const struct afb_proto_ws_server_itf *itf, void *closure)
1176 {
1177         return afb_proto_ws_create(eloop, fd, itf, NULL, closure, &server_ws_itf);
1178 }
1179
1180 void afb_proto_ws_unref(struct afb_proto_ws *protows)
1181 {
1182         if (!__atomic_sub_fetch(&protows->refcount, 1, __ATOMIC_RELAXED)) {
1183                 afb_proto_ws_hangup(protows);
1184                 afb_ws_destroy(protows->ws);
1185                 pthread_mutex_destroy(&protows->mutex);
1186                 free(protows);
1187         }
1188 }
1189
1190 void afb_proto_ws_addref(struct afb_proto_ws *protows)
1191 {
1192         __atomic_add_fetch(&protows->refcount, 1, __ATOMIC_RELAXED);
1193 }
1194
1195 int afb_proto_ws_is_client(struct afb_proto_ws *protows)
1196 {
1197         return !!protows->client_itf;
1198 }
1199
1200 int afb_proto_ws_is_server(struct afb_proto_ws *protows)
1201 {
1202         return !!protows->server_itf;
1203 }
1204
1205 void afb_proto_ws_hangup(struct afb_proto_ws *protows)
1206 {
1207         afb_ws_hangup(protows->ws);
1208 }
1209
1210 void afb_proto_ws_on_hangup(struct afb_proto_ws *protows, void (*on_hangup)(void *closure))
1211 {
1212         protows->on_hangup = on_hangup;
1213 }
1214