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
 347         if (writebuf_char(&wb, CHAR_FOR_ANSWER_SUCCESS)
 348          && writebuf_uint32(&wb, call->callid)
 349          && writebuf_string(&wb, info ?: "")
 350          && writebuf_object(&wb, obj)) {
 351                 rc = afb_ws_binary_v(call->protows->ws, wb.iovec, wb.count);
 352                 if (rc >= 0) {
 353                         rc = 0;
 354                         goto success;
 355                 }
 356         }
 357 success:
 358         return rc;
 359 }
 360
 361 int afb_proto_ws_call_fail(struct afb_proto_ws_call *call, const char *status, const char *info)
 362 {
 363         int rc = -1;
 364         struct writebuf wb = { .count = 0 };
 365
 366         if (writebuf_char(&wb, CHAR_FOR_ANSWER_FAIL)
 367          && writebuf_uint32(&wb, call->callid)
 368          && writebuf_string(&wb, status)
 369          && writebuf_string(&wb, info ? : "")) {
 370                 rc = afb_ws_binary_v(call->protows->ws, wb.iovec, wb.count);
 371                 if (rc >= 0) {
 372                         rc = 0;
 373                         goto success;
 374                 }
 375         }
 376 success:
 377         return rc;
 378 }
 379
 380 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)
 381 {
 382         int rc = -1;
 383         struct writebuf wb = { .count = 0 };
 384         struct server_subcall *sc, *osc;
 385         struct afb_proto_ws *protows = call->protows;
 386
 387         sc = malloc(sizeof *sc);
 388         if (!sc)
 389                 errno = ENOMEM;
 390         else {
 391                 sc->callback = callback;
 392                 sc->closure = cb_closure;
 393
 394                 pthread_mutex_unlock(&protows->mutex);
 395                 sc->subcallid = ptr2id(sc);
 396                 do {
 397                         sc->subcallid++;
 398                         osc = protows->subcalls;
 399                         while(osc && osc->subcallid != sc->subcallid)
 400                                 osc = osc->next;
 401                 } while (osc);
 402                 sc->next = protows->subcalls;
 403                 protows->subcalls = sc;
 404                 pthread_mutex_unlock(&protows->mutex);
 405
 406                 if (writebuf_char(&wb, CHAR_FOR_SUBCALL_CALL)
 407                  && writebuf_uint32(&wb, sc->subcallid)
 408                  && writebuf_uint32(&wb, call->callid)
 409                  && writebuf_string(&wb, api)
 410                  && writebuf_string(&wb, verb)
 411                  && writebuf_object(&wb, args)) {
 412                         rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 413                         if (rc >= 0) {
 414                                 rc = 0;
 415                                 goto success;
 416                         }
 417                 }
 418         }
 419 success:
 420         return rc;
 421 }
 422
 423 int afb_proto_ws_call_subscribe(struct afb_proto_ws_call *call, const char *event_name, int event_id)
 424 {
 425         int rc = -1;
 426         struct writebuf wb = { .count = 0 };
 427
 428         if (writebuf_char(&wb, CHAR_FOR_EVT_SUBSCRIBE)
 429          && writebuf_uint32(&wb, call->callid)
 430          && writebuf_uint32(&wb, (uint32_t)event_id)
 431          && writebuf_string(&wb, event_name)) {
 432                 rc = afb_ws_binary_v(call->protows->ws, wb.iovec, wb.count);
 433                 if (rc >= 0) {
 434                         rc = 0;
 435                         goto success;
 436                 }
 437         }
 438 success:
 439         return rc;
 440 }
 441
 442 int afb_proto_ws_call_unsubscribe(struct afb_proto_ws_call *call, const char *event_name, int event_id)
 443 {
 444         int rc = -1;
 445         struct writebuf wb = { .count = 0 };
 446
 447         if (writebuf_char(&wb, CHAR_FOR_EVT_UNSUBSCRIBE)
 448          && writebuf_uint32(&wb, call->callid)
 449          && writebuf_uint32(&wb, (uint32_t)event_id)
 450          && writebuf_string(&wb, event_name)) {
 451                 rc = afb_ws_binary_v(call->protows->ws, wb.iovec, wb.count);
 452                 if (rc >= 0) {
 453                         rc = 0;
 454                         goto success;
 455                 }
 456         }
 457 success:
 458         return rc;
 459 }
 460
 461 /******************* client part **********************************/
 462
 463 /* search a memorized call */
 464 static struct client_call *client_call_search(struct afb_proto_ws *protows, uint32_t callid)
 465 {
 466         struct client_call *call;
 467
 468         call = protows->calls;
 469         while (call != NULL && call->callid != callid)
 470                 call = call->next;
 471
 472         return call;
 473 }
 474
 475 /* free and release the memorizing call */
 476 static void client_call_destroy(struct client_call *call)
 477 {
 478         struct client_call **prv;
 479
 480         prv = &call->protows->calls;
 481         while (*prv != NULL) {
 482                 if (*prv == call) {
 483                         *prv = call->next;
 484                         break;
 485                 }
 486                 prv = &(*prv)->next;
 487         }
 488         free(call);
 489 }
 490
 491 /* get event data from the message */
 492 static int client_msg_event_read(struct readbuf *rb, uint32_t *eventid, const char **name)
 493 {
 494         return readbuf_uint32(rb, eventid) && readbuf_string(rb, name, NULL);
 495 }
 496
 497 /* get event from the message */
 498 static int client_msg_call_get(struct afb_proto_ws *protows, struct readbuf *rb, struct client_call **call)
 499 {
 500         uint32_t callid;
 501
 502         /* get event data from the message */
 503         if (!readbuf_uint32(rb, &callid)) {
 504                 return 0;
 505         }
 506
 507         /* get the call */
 508         *call = client_call_search(protows, callid);
 509         if (*call == NULL) {
 510                 return 0;
 511         }
 512
 513         return 1;
 514 }
 515
 516 /* adds an event */
 517 static void client_on_event_create(struct afb_proto_ws *protows, struct readbuf *rb)
 518 {
 519         const char *event_name;
 520         uint32_t event_id;
 521
 522         if (protows->client_itf->on_event_create && client_msg_event_read(rb, &event_id, &event_name))
 523                 protows->client_itf->on_event_create(protows->closure, event_name, (int)event_id);
 524 }
 525
 526 /* removes an event */
 527 static void client_on_event_remove(struct afb_proto_ws *protows, struct readbuf *rb)
 528 {
 529         const char *event_name;
 530         uint32_t event_id;
 531
 532         if (protows->client_itf->on_event_remove && client_msg_event_read(rb, &event_id, &event_name))
 533                 protows->client_itf->on_event_remove(protows->closure, event_name, (int)event_id);
 534 }
 535
 536 /* subscribes an event */
 537 static void client_on_event_subscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 538 {
 539         const char *event_name;
 540         uint32_t event_id;
 541         struct client_call *call;
 542
 543         if (protows->client_itf->on_event_subscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 544                 protows->client_itf->on_event_subscribe(protows->closure, call->request, event_name, (int)event_id);
 545 }
 546
 547 /* unsubscribes an event */
 548 static void client_on_event_unsubscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 549 {
 550         const char *event_name;
 551         uint32_t event_id;
 552         struct client_call *call;
 553
 554         if (protows->client_itf->on_event_unsubscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 555                 protows->client_itf->on_event_unsubscribe(protows->closure, call->request, event_name, (int)event_id);
 556 }
 557
 558 /* receives broadcasted events */
 559 static void client_on_event_broadcast(struct afb_proto_ws *protows, struct readbuf *rb)
 560 {
 561         const char *event_name;
 562         struct json_object *object;
 563
 564         if (protows->client_itf->on_event_broadcast && readbuf_string(rb, &event_name, NULL) && readbuf_object(rb, &object))
 565                 protows->client_itf->on_event_broadcast(protows->closure, event_name, object);
 566 }
 567
 568 /* pushs an event */
 569 static void client_on_event_push(struct afb_proto_ws *protows, struct readbuf *rb)
 570 {
 571         const char *event_name;
 572         uint32_t event_id;
 573         struct json_object *object;
 574
 575         if (protows->client_itf->on_event_push && client_msg_event_read(rb, &event_id, &event_name) && readbuf_object(rb, &object))
 576                 protows->client_itf->on_event_push(protows->closure, event_name, (int)event_id, object);
 577 }
 578
 579 static void client_on_reply_success(struct afb_proto_ws *protows, struct readbuf *rb)
 580 {
 581         struct client_call *call;
 582         struct json_object *object;
 583         const char *info;
 584
 585         if (!client_msg_call_get(protows, rb, &call))
 586                 return;
 587
 588         if (readbuf_string(rb, &info, NULL) && readbuf_object(rb, &object)) {
 589                 protows->client_itf->on_reply_success(protows->closure, call->request, object, info);
 590         } else {
 591                 protows->client_itf->on_reply_fail(protows->closure, call->request, "proto-error", "can't process success");
 592         }
 593         client_call_destroy(call);
 594 }
 595
 596 static void client_on_reply_fail(struct afb_proto_ws *protows, struct readbuf *rb)
 597 {
 598         struct client_call *call;
 599         const char *info, *status;
 600
 601         if (!client_msg_call_get(protows, rb, &call))
 602                 return;
 603
 604         if (readbuf_string(rb, &status, NULL) && readbuf_string(rb, &info, NULL)) {
 605                 protows->client_itf->on_reply_fail(protows->closure, call->request, status, info);
 606         } else {
 607                 protows->client_itf->on_reply_fail(protows->closure, call->request, "proto-error", "can't process fail");
 608         }
 609         client_call_destroy(call);
 610 }
 611
 612 /* send a subcall reply */
 613 static int client_send_subcall_reply(struct afb_proto_ws *protows, uint32_t subcallid, int status, json_object *object)
 614 {
 615         struct writebuf wb = { .count = 0 };
 616         char ie = status < 0;
 617
 618         return -!(writebuf_char(&wb, CHAR_FOR_SUBCALL_REPLY)
 619          && writebuf_uint32(&wb, subcallid)
 620          && writebuf_char(&wb, ie)
 621          && writebuf_object(&wb, object)
 622          && afb_ws_binary_v(protows->ws, wb.iovec, wb.count) >= 0);
 623 }
 624
 625 /* callback for subcall reply */
 626 int afb_proto_ws_subcall_reply(struct afb_proto_ws_subcall *subcall, int status, struct json_object *result)
 627 {
 628         int rc = client_send_subcall_reply(subcall->protows, subcall->subcallid, status, result);
 629         afb_proto_ws_unref(subcall->protows);
 630         free(subcall->buffer);
 631         free(subcall);
 632         return rc;
 633 }
 634
 635 /* received a subcall request */
 636 static void client_on_subcall(struct afb_proto_ws *protows, struct readbuf *rb)
 637 {
 638         struct afb_proto_ws_subcall *subcall;
 639         struct client_call *call;
 640         const char *api, *verb;
 641         uint32_t subcallid;
 642         struct json_object *object;
 643
 644         /* get the subcallid */
 645         if (!readbuf_uint32(rb, &subcallid))
 646                 return;
 647
 648         /* if not expected drop it */
 649         if (!protows->client_itf->on_subcall)
 650                 goto error;
 651
 652         /* retrieve the message data */
 653         if (!client_msg_call_get(protows, rb, &call))
 654                 goto error;
 655
 656         /* allocation of the subcall */
 657         subcall = malloc(sizeof *subcall);
 658         if (!subcall)
 659                 goto error;
 660
 661         /* make the call */
 662         if (readbuf_string(rb, &api, NULL)
 663          && readbuf_string(rb, &verb, NULL)
 664          && readbuf_object(rb, &object)) {
 665                 afb_proto_ws_addref(protows);
 666                 subcall->protows = protows;
 667                 subcall->subcallid = subcallid;
 668                 subcall->buffer = rb->base;
 669                 rb->base = NULL;
 670                 protows->client_itf->on_subcall(protows->closure, subcall, call->request, api, verb, object);
 671                 return;
 672         }
 673         free(subcall);
 674 error:
 675         client_send_subcall_reply(protows, subcallid, 1, NULL);
 676 }
 677
 678 static void client_on_description(struct afb_proto_ws *protows, struct readbuf *rb)
 679 {
 680         uint32_t descid;
 681         struct client_describe *desc, **prv;
 682         struct json_object *object;
 683
 684         if (readbuf_uint32(rb, &descid)) {
 685                 prv = &protows->describes;
 686                 while ((desc = *prv) && desc->descid != descid)
 687                         prv = &desc->next;
 688                 if (desc) {
 689                         *prv = desc->next;
 690                         if (!readbuf_object(rb, &object))
 691                                 object = NULL;
 692                         desc->callback(desc->closure, object);
 693                         free(desc);
 694                 }
 695         }
 696 }
 697
 698 /* callback when receiving binary data */
 699 static void client_on_binary(void *closure, char *data, size_t size)
 700 {
 701         struct afb_proto_ws *protows;
 702         struct readbuf rb;
 703
 704         rb.base = data;
 705         if (size > 0) {
 706                 rb.head = data;
 707                 rb.end = data + size;
 708                 protows = closure;
 709
 710                 pthread_mutex_lock(&protows->mutex);
 711                 switch (*rb.head++) {
 712                 case CHAR_FOR_ANSWER_SUCCESS: /* success */
 713                         client_on_reply_success(protows, &rb);
 714                         break;
 715                 case CHAR_FOR_ANSWER_FAIL: /* fail */
 716                         client_on_reply_fail(protows, &rb);
 717                         break;
 718                 case CHAR_FOR_EVT_BROADCAST: /* broadcast */
 719                         client_on_event_broadcast(protows, &rb);
 720                         break;
 721                 case CHAR_FOR_EVT_ADD: /* creates the event */
 722                         client_on_event_create(protows, &rb);
 723                         break;
 724                 case CHAR_FOR_EVT_DEL: /* removes the event */
 725                         client_on_event_remove(protows, &rb);
 726                         break;
 727                 case CHAR_FOR_EVT_PUSH: /* pushs the event */
 728                         client_on_event_push(protows, &rb);
 729                         break;
 730                 case CHAR_FOR_EVT_SUBSCRIBE: /* subscribe event for a request */
 731                         client_on_event_subscribe(protows, &rb);
 732                         break;
 733                 case CHAR_FOR_EVT_UNSUBSCRIBE: /* unsubscribe event for a request */
 734                         client_on_event_unsubscribe(protows, &rb);
 735                         break;
 736                 case CHAR_FOR_SUBCALL_CALL: /* subcall */
 737                         client_on_subcall(protows, &rb);
 738                         break;
 739                 case CHAR_FOR_DESCRIPTION: /* description */
 740                         client_on_description(protows, &rb);
 741                         break;
 742                 default: /* unexpected message */
 743                         /* TODO: close the connection */
 744                         break;
 745                 }
 746                 pthread_mutex_unlock(&protows->mutex);
 747         }
 748         free(rb.base);
 749 }
 750
 751 int afb_proto_ws_client_call(
 752                 struct afb_proto_ws *protows,
 753                 const char *verb,
 754                 struct json_object *args,
 755                 const char *sessionid,
 756                 void *request
 757 )
 758 {
 759         int rc = -1;
 760         struct client_call *call;
 761         struct writebuf wb = { .count = 0 };
 762
 763         /* allocate call data */
 764         call = malloc(sizeof *call);
 765         if (call == NULL) {
 766                 errno = ENOMEM;
 767                 return -1;
 768         }
 769         call->request = request;
 770
 771         /* init call data */
 772         pthread_mutex_lock(&protows->mutex);
 773         call->callid = ptr2id(call);
 774         while(client_call_search(protows, call->callid) != NULL)
 775                 call->callid++;
 776         call->protows = protows;
 777         call->next = protows->calls;
 778         protows->calls = call;
 779
 780         /* creates the call message */
 781         if (!writebuf_char(&wb, CHAR_FOR_CALL)
 782          || !writebuf_uint32(&wb, call->callid)
 783          || !writebuf_string(&wb, verb)
 784          || !writebuf_string(&wb, sessionid)
 785          || !writebuf_object(&wb, args)) {
 786                 errno = EINVAL;
 787                 goto clean;
 788         }
 789
 790         /* send */
 791         rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 792         if (rc >= 0) {
 793                 rc = 0;
 794                 goto end;
 795         }
 796
 797 clean:
 798         client_call_destroy(call);
 799 end:
 800         pthread_mutex_unlock(&protows->mutex);
 801         return rc;
 802 }
 803
 804 /* get the description */
 805 int afb_proto_ws_client_describe(struct afb_proto_ws *protows, void (*callback)(void*, struct json_object*), void *closure)
 806 {
 807         struct client_describe *desc, *d;
 808         struct writebuf wb = { .count = 0 };
 809
 810         desc = malloc(sizeof *desc);
 811         if (!desc) {
 812                 errno = ENOMEM;
 813                 goto error;
 814         }
 815
 816         /* fill in stack the description of the task */
 817         pthread_mutex_lock(&protows->mutex);
 818         desc->descid = ptr2id(desc);
 819         d = protows->describes;
 820         while (d) {
 821                 if (d->descid != desc->descid)
 822                         d = d->next;
 823                 else {
 824                         desc->descid++;
 825                         d = protows->describes;
 826                 }
 827         }
 828         desc->callback = callback;
 829         desc->closure = closure;
 830         desc->protows = protows;
 831         desc->next = protows->describes;
 832         protows->describes = desc;
 833         pthread_mutex_unlock(&protows->mutex);
 834
 835         /* send */
 836         if (writebuf_char(&wb, CHAR_FOR_DESCRIBE)
 837          && writebuf_uint32(&wb, desc->descid)
 838          && afb_ws_binary_v(protows->ws, wb.iovec, wb.count) >= 0)
 839                 return 0;
 840
 841         pthread_mutex_lock(&protows->mutex);
 842         d = protows->describes;
 843         if (d == desc)
 844                 protows->describes = desc->next;
 845         else {
 846                 while(d && d->next != desc)
 847                         d = d->next;
 848                 if (d)
 849                         d->next = desc->next;
 850         }
 851         free(desc);
 852         pthread_mutex_unlock(&protows->mutex);
 853 error:
 854         /* TODO? callback(closure, NULL); */
 855         return -1;
 856 }
 857
 858 /******************* client description part for server *****************************/
 859
 860 /* on call, propagate it to the ws service */
 861 static void server_on_call(struct afb_proto_ws *protows, struct readbuf *rb)
 862 {
 863         struct afb_proto_ws_call *call;
 864         const char *uuid, *verb;
 865         uint32_t callid;
 866         size_t lenverb;
 867         struct json_object *object;
 868
 869         afb_proto_ws_addref(protows);
 870
 871         /* reads the call message data */
 872         if (!readbuf_uint32(rb, &callid)
 873          || !readbuf_string(rb, &verb, &lenverb)
 874          || !readbuf_string(rb, &uuid, NULL)
 875          || !readbuf_object(rb, &object))
 876                 goto overflow;
 877
 878         /* create the request */
 879         call = malloc(sizeof *call);
 880         if (call == NULL)
 881                 goto out_of_memory;
 882
 883         call->protows = protows;
 884         call->callid = callid;
 885         call->refcount = 1;
 886         call->buffer = rb->base;
 887         rb->base = NULL; /* don't free the buffer */
 888
 889         protows->server_itf->on_call(protows->closure, call, verb, object, uuid);
 890         return;
 891
 892 out_of_memory:
 893         json_object_put(object);
 894
 895 overflow:
 896         afb_proto_ws_unref(protows);
 897 }
 898
 899 /* on subcall reply */
 900 static void server_on_subcall_reply(struct afb_proto_ws *protows, struct readbuf *rb)
 901 {
 902         char ie;
 903         uint32_t subcallid;
 904         struct json_object *object;
 905         struct server_subcall *sc, **psc;
 906
 907         /* reads the call message data */
 908         if (!readbuf_uint32(rb, &subcallid)
 909          || !readbuf_char(rb, &ie)
 910          || !readbuf_object(rb, &object)) {
 911                 /* TODO bad protocol */
 912                 return;
 913         }
 914
 915         /* search the subcall and unlink it */
 916         pthread_mutex_lock(&protows->mutex);
 917         psc = &protows->subcalls;
 918         while ((sc = *psc) && sc->subcallid != subcallid)
 919                 psc = &sc->next;
 920         if (!sc) {
 921                 pthread_mutex_unlock(&protows->mutex);
 922                 json_object_put(object);
 923                 /* TODO subcall not found */
 924         } else {
 925                 *psc = sc->next;
 926                 pthread_mutex_unlock(&protows->mutex);
 927                 sc->callback(sc->closure, -(int)ie, object);
 928                 free(sc);
 929         }
 930 }
 931
 932 static int server_send_description(struct afb_proto_ws *protows, uint32_t descid, struct json_object *descobj)
 933 {
 934         struct writebuf wb = { .count = 0 };
 935
 936         return -!(writebuf_char(&wb, CHAR_FOR_DESCRIPTION)
 937                  && writebuf_uint32(&wb, descid)
 938                  && writebuf_object(&wb, descobj)
 939                  && afb_ws_binary_v(protows->ws, wb.iovec, wb.count) >= 0);
 940 }
 941
 942 int afb_proto_ws_describe_put(struct afb_proto_ws_describe *describe, struct json_object *description)
 943 {
 944         int rc = server_send_description(describe->protows, describe->descid, description);
 945         afb_proto_ws_addref(describe->protows);
 946         free(describe);
 947         return rc;
 948 }
 949
 950 /* on describe, propagate it to the ws service */
 951 static void server_on_describe(struct afb_proto_ws *protows, struct readbuf *rb)
 952 {
 953         uint32_t descid;
 954         struct afb_proto_ws_describe *desc;
 955
 956         /* reads the descid */
 957         if (readbuf_uint32(rb, &descid)) {
 958                 if (protows->server_itf->on_describe) {
 959                         /* create asynchronous job */
 960                         desc = malloc(sizeof *desc);
 961                         if (desc) {
 962                                 desc->descid = descid;
 963                                 desc->protows = protows;
 964                                 afb_proto_ws_addref(protows);
 965                                 protows->server_itf->on_describe(protows->closure, desc);
 966                                 return;
 967                         }
 968                 }
 969                 server_send_description(protows, descid, NULL);
 970         }
 971 }
 972
 973 /* callback when receiving binary data */
 974 static void server_on_binary(void *closure, char *data, size_t size)
 975 {
 976         struct afb_proto_ws *protows;
 977         struct readbuf rb;
 978
 979         rb.base = data;
 980         if (size > 0) {
 981                 rb.head = data;
 982                 rb.end = data + size;
 983                 protows = closure;
 984
 985                 switch (*rb.head++) {
 986                 case CHAR_FOR_CALL:
 987                         server_on_call(protows, &rb);
 988                         break;
 989                 case CHAR_FOR_SUBCALL_REPLY:
 990                         server_on_subcall_reply(protows, &rb);
 991                         break;
 992                 case CHAR_FOR_DESCRIBE:
 993                         server_on_describe(protows, &rb);
 994                         break;
 995                 default: /* unexpected message */
 996                         /* TODO: close the connection */
 997                         break;
 998                 }
 999         }
1000         free(rb.base);
1001 }
1002
1003 /******************* server part: manage events **********************************/
1004
1005 static int server_event_send(struct afb_proto_ws *protows, char order, const char *event_name, int event_id, struct json_object *data)
1006 {
1007         struct writebuf wb = { .count = 0 };
1008
1009         return -!(writebuf_char(&wb, order)
1010                  && (order == CHAR_FOR_EVT_BROADCAST || writebuf_uint32(&wb, event_id))
1011                  && writebuf_string(&wb, event_name)
1012                  && (order == CHAR_FOR_EVT_ADD || order == CHAR_FOR_EVT_DEL || writebuf_object(&wb, data))
1013                  && afb_ws_binary_v(protows->ws, wb.iovec, wb.count) >= 0);
1014 }
1015
1016 int afb_proto_ws_server_event_create(struct afb_proto_ws *protows, const char *event_name, int event_id)
1017 {
1018         return server_event_send(protows, CHAR_FOR_EVT_ADD, event_name, event_id, NULL);
1019 }
1020
1021 int afb_proto_ws_server_event_remove(struct afb_proto_ws *protows, const char *event_name, int event_id)
1022 {
1023         return server_event_send(protows, CHAR_FOR_EVT_DEL, event_name, event_id, NULL);
1024 }
1025
1026 int afb_proto_ws_server_event_push(struct afb_proto_ws *protows, const char *event_name, int event_id, struct json_object *data)
1027 {
1028         return server_event_send(protows, CHAR_FOR_EVT_PUSH, event_name, event_id, data);
1029 }
1030
1031 int afb_proto_ws_server_event_broadcast(struct afb_proto_ws *protows, const char *event_name, struct json_object *data)
1032 {
1033         return server_event_send(protows, CHAR_FOR_EVT_BROADCAST, event_name, 0, data);
1034 }
1035
1036 /*****************************************************/
1037
1038 /* callback when receiving a hangup */
1039 static void on_hangup(void *closure)
1040 {
1041         struct afb_proto_ws *protows = closure;
1042         struct server_subcall *sc, *nsc;
1043         struct client_describe *cd, *ncd;
1044
1045         nsc = protows->subcalls;
1046         while (nsc) {
1047                 sc= nsc;
1048                 nsc = sc->next;
1049                 sc->callback(sc->closure, 1, NULL);
1050                 free(sc);
1051         }
1052
1053         ncd = protows->describes;
1054         while (ncd) {
1055                 cd= ncd;
1056                 ncd = cd->next;
1057                 cd->callback(cd->closure, NULL);
1058                 free(cd);
1059         }
1060
1061         if (protows->fd >= 0) {
1062                 protows->fd = -1;
1063                 if (protows->on_hangup)
1064                         protows->on_hangup(protows->closure);
1065         }
1066 }
1067
1068 /*****************************************************/
1069
1070 static const struct afb_ws_itf proto_ws_client_ws_itf =
1071 {
1072         .on_close = NULL,
1073         .on_text = NULL,
1074         .on_binary = client_on_binary,
1075         .on_error = NULL,
1076         .on_hangup = on_hangup
1077 };
1078
1079 static const struct afb_ws_itf server_ws_itf =
1080 {
1081         .on_close = NULL,
1082         .on_text = NULL,
1083         .on_binary = server_on_binary,
1084         .on_error = NULL,
1085         .on_hangup = on_hangup
1086 };
1087
1088 /*****************************************************/
1089
1090 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)
1091 {
1092         struct afb_proto_ws *protows;
1093
1094         protows = calloc(1, sizeof *protows);
1095         if (protows == NULL)
1096                 errno = ENOMEM;
1097         else {
1098                 fcntl(fd, F_SETFD, FD_CLOEXEC);
1099                 fcntl(fd, F_SETFL, O_NONBLOCK);
1100                 protows->ws = afb_ws_create(eloop, fd, itf, protows);
1101                 if (protows->ws != NULL) {
1102                         protows->fd = fd;
1103                         protows->refcount = 1;
1104                         protows->subcalls = NULL;
1105                         protows->closure = closure;
1106                         protows->server_itf = itfs;
1107                         protows->client_itf = itfc;
1108                         pthread_mutex_init(&protows->mutex, NULL);
1109                         return protows;
1110                 }
1111                 free(protows);
1112         }
1113         return NULL;
1114 }
1115
1116 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)
1117 {
1118         return afb_proto_ws_create(eloop, fd, NULL, itf, closure, &proto_ws_client_ws_itf);
1119 }
1120
1121 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)
1122 {
1123         return afb_proto_ws_create(eloop, fd, itf, NULL, closure, &server_ws_itf);
1124 }
1125
1126 void afb_proto_ws_unref(struct afb_proto_ws *protows)
1127 {
1128         if (!__atomic_sub_fetch(&protows->refcount, 1, __ATOMIC_RELAXED)) {
1129                 afb_proto_ws_hangup(protows);
1130                 afb_ws_destroy(protows->ws);
1131                 pthread_mutex_destroy(&protows->mutex);
1132                 free(protows);
1133         }
1134 }
1135
1136 void afb_proto_ws_addref(struct afb_proto_ws *protows)
1137 {
1138         __atomic_add_fetch(&protows->refcount, 1, __ATOMIC_RELAXED);
1139 }
1140
1141 int afb_proto_ws_is_client(struct afb_proto_ws *protows)
1142 {
1143         return !!protows->client_itf;
1144 }
1145
1146 int afb_proto_ws_is_server(struct afb_proto_ws *protows)
1147 {
1148         return !!protows->server_itf;
1149 }
1150
1151 void afb_proto_ws_hangup(struct afb_proto_ws *protows)
1152 {
1153         afb_ws_hangup(protows->ws);
1154 }
1155
1156 void afb_proto_ws_on_hangup(struct afb_proto_ws *protows, void (*on_hangup)(void *closure))
1157 {
1158         protows->on_hangup = on_hangup;
1159 }
1160