src/afb-proto-ws.c

   1 /*
   2  * Copyright (C) 2015-2018 "IoT.bzh"
   3  * Author José Bollo <jose.bollo@iot.bzh>
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *   http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #define _GNU_SOURCE
  19
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <assert.h>
  23 #include <fcntl.h>
  24 #include <unistd.h>
  25 #include <errno.h>
  26 #include <endian.h>
  27 #include <netdb.h>
  28 #include <sys/types.h>
  29 #include <sys/socket.h>
  30 #include <sys/un.h>
  31 #include <pthread.h>
  32
  33 #include <json-c/json.h>
  34
  35 #include "afb-ws.h"
  36 #include "afb-msg-json.h"
  37 #include "afb-proto-ws.h"
  38 #include "fdev.h"
  39 #include "verbose.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   - subscribe or unsubscribe an event
  63
  64 For the purpose of handling events the server can:
  65
  66   - create/destroy an event
  67
  68   - push or brodcast data as an event
  69
  70 */
  71 /************** constants for protocol definition *************************/
  72
  73 #define CHAR_FOR_CALL             'C'
  74 #define CHAR_FOR_REPLY            'Y'
  75 #define CHAR_FOR_EVT_BROADCAST    '*'
  76 #define CHAR_FOR_EVT_ADD          '+'
  77 #define CHAR_FOR_EVT_DEL          '-'
  78 #define CHAR_FOR_EVT_PUSH         '!'
  79 #define CHAR_FOR_EVT_SUBSCRIBE    'S'
  80 #define CHAR_FOR_EVT_UNSUBSCRIBE  'U'
  81 #define CHAR_FOR_DESCRIBE         'D'
  82 #define CHAR_FOR_DESCRIPTION      'd'
  83
  84 /******************* handling calls *****************************/
  85
  86 /*
  87  * structure for recording calls on client side
  88  */
  89 struct client_call {
  90         struct client_call *next;       /* the next call */
  91         struct afb_proto_ws *protows;   /* the proto_ws */
  92         void *request;                  /* the request closure */
  93         uint32_t callid;                /* the message identifier */
  94 };
  95
  96 /*
  97  * structure for a ws request
  98  */
  99 struct afb_proto_ws_call {
 100         struct client_call *next;       /* the next call */
 101         struct afb_proto_ws *protows;   /* the client of the request */
 102         uint32_t refcount;              /* reference count */
 103         uint32_t callid;                /* the incoming request callid */
 104         char *buffer;                   /* the incoming buffer */
 105 };
 106
 107 /*
 108  * structure for recording describe requests
 109  */
 110 struct client_describe
 111 {
 112         struct client_describe *next;
 113         struct afb_proto_ws *protows;
 114         void (*callback)(void*, struct json_object*);
 115         void *closure;
 116         uint32_t descid;
 117 };
 118
 119 /*
 120  * structure for jobs of describing
 121  */
 122 struct afb_proto_ws_describe
 123 {
 124         struct afb_proto_ws *protows;
 125         uint32_t descid;
 126 };
 127
 128 /******************* proto description for client or servers ******************/
 129
 130 struct afb_proto_ws
 131 {
 132         /* count of references */
 133         int refcount;
 134
 135         /* file descriptor */
 136         struct fdev *fdev;
 137
 138         /* resource control */
 139         pthread_mutex_t mutex;
 140
 141         /* websocket */
 142         struct afb_ws *ws;
 143
 144         /* the client closure */
 145         void *closure;
 146
 147         /* the client side interface */
 148         const struct afb_proto_ws_client_itf *client_itf;
 149
 150         /* the server side interface */
 151         const struct afb_proto_ws_server_itf *server_itf;
 152
 153         /* emitted calls (client side) */
 154         struct client_call *calls;
 155
 156         /* pending description (client side) */
 157         struct client_describe *describes;
 158
 159         /* on hangup callback */
 160         void (*on_hangup)(void *closure);
 161
 162         /* queuing facility for processing messages */
 163         int (*queuing)(struct afb_proto_ws *proto, void (*process)(int s, void *c), void *closure);
 164 };
 165
 166 /******************* streaming objects **********************************/
 167
 168 #define WRITEBUF_COUNT_MAX  32
 169 struct writebuf
 170 {
 171         struct iovec iovec[WRITEBUF_COUNT_MAX];
 172         uint32_t uints[WRITEBUF_COUNT_MAX];
 173         int count;
 174 };
 175
 176 struct readbuf
 177 {
 178         char *base, *head, *end;
 179 };
 180
 181 struct binary
 182 {
 183         struct afb_proto_ws *protows;
 184         struct readbuf rb;
 185 };
 186
 187 /******************* common useful tools **********************************/
 188
 189 /**
 190  * translate a pointer to some integer
 191  * @param ptr the pointer to translate
 192  * @return an integer
 193  */
 194 static inline uint32_t ptr2id(void *ptr)
 195 {
 196         return (uint32_t)(((intptr_t)ptr) >> 6);
 197 }
 198
 199 /******************* serialisation part **********************************/
 200
 201 static char *readbuf_get(struct readbuf *rb, uint32_t length)
 202 {
 203         char *before = rb->head;
 204         char *after = before + length;
 205         if (after > rb->end)
 206                 return 0;
 207         rb->head = after;
 208         return before;
 209 }
 210
 211 __attribute__((unused))
 212 static int readbuf_char(struct readbuf *rb, char *value)
 213 {
 214         if (rb->head >= rb->end)
 215                 return 0;
 216         *value = *rb->head++;
 217         return 1;
 218 }
 219
 220 static int readbuf_uint32(struct readbuf *rb, uint32_t *value)
 221 {
 222         char *after = rb->head + sizeof *value;
 223         if (after > rb->end)
 224                 return 0;
 225         memcpy(value, rb->head, sizeof *value);
 226         rb->head = after;
 227         *value = le32toh(*value);
 228         return 1;
 229 }
 230
 231 static int _readbuf_string_(struct readbuf *rb, const char **value, size_t *length, int nulok)
 232 {
 233         uint32_t len;
 234         if (!readbuf_uint32(rb, &len))
 235                 return 0;
 236         if (!len) {
 237                 if (!nulok)
 238                         return 0;
 239                 *value = NULL;
 240                 if (length)
 241                         *length = 0;
 242                 return 1;
 243         }
 244         if (length)
 245                 *length = (size_t)(len - 1);
 246         return (*value = readbuf_get(rb, len)) != NULL &&  rb->head[-1] == 0;
 247 }
 248
 249
 250 static int readbuf_string(struct readbuf *rb, const char **value, size_t *length)
 251 {
 252         return _readbuf_string_(rb, value, length, 0);
 253 }
 254
 255 static int readbuf_nullstring(struct readbuf *rb, const char **value, size_t *length)
 256 {
 257         return _readbuf_string_(rb, value, length, 1);
 258 }
 259
 260 static int readbuf_object(struct readbuf *rb, struct json_object **object)
 261 {
 262         const char *string;
 263         struct json_object *o;
 264         enum json_tokener_error jerr;
 265         int rc = readbuf_string(rb, &string, NULL);
 266         if (rc) {
 267                 o = json_tokener_parse_verbose(string, &jerr);
 268                 if (jerr != json_tokener_success)
 269                         o = json_object_new_string(string);
 270                 *object = o;
 271         }
 272         return rc;
 273 }
 274
 275 static int writebuf_put(struct writebuf *wb, const void *value, size_t length)
 276 {
 277         int i = wb->count;
 278         if (i == WRITEBUF_COUNT_MAX)
 279                 return 0;
 280         wb->iovec[i].iov_base = (void*)value;
 281         wb->iovec[i].iov_len = length;
 282         wb->count = i + 1;
 283         return 1;
 284 }
 285
 286 static int writebuf_char(struct writebuf *wb, char value)
 287 {
 288         int i = wb->count;
 289         if (i == WRITEBUF_COUNT_MAX)
 290                 return 0;
 291         *(char*)&wb->uints[i] = value;
 292         wb->iovec[i].iov_base = &wb->uints[i];
 293         wb->iovec[i].iov_len = 1;
 294         wb->count = i + 1;
 295         return 1;
 296 }
 297
 298 static int writebuf_uint32(struct writebuf *wb, uint32_t value)
 299 {
 300         int i = wb->count;
 301         if (i == WRITEBUF_COUNT_MAX)
 302                 return 0;
 303         wb->uints[i] = htole32(value);
 304         wb->iovec[i].iov_base = &wb->uints[i];
 305         wb->iovec[i].iov_len = sizeof wb->uints[i];
 306         wb->count = i + 1;
 307         return 1;
 308 }
 309
 310 static int writebuf_string_length(struct writebuf *wb, const char *value, size_t length)
 311 {
 312         uint32_t len = (uint32_t)++length;
 313         return (size_t)len == length && len && writebuf_uint32(wb, len) && writebuf_put(wb, value, length);
 314 }
 315
 316 static int writebuf_string(struct writebuf *wb, const char *value)
 317 {
 318         return writebuf_string_length(wb, value, strlen(value));
 319 }
 320
 321 static int writebuf_nullstring(struct writebuf *wb, const char *value)
 322 {
 323         return value ? writebuf_string_length(wb, value, strlen(value)) : writebuf_uint32(wb, 0);
 324 }
 325
 326 static int writebuf_object(struct writebuf *wb, struct json_object *object)
 327 {
 328         const char *string = json_object_to_json_string_ext(object, JSON_C_TO_STRING_PLAIN);
 329         return string != NULL && writebuf_string(wb, string);
 330 }
 331
 332 /******************* queuing of messages *****************/
 333
 334 /* queue the processing of the received message (except if size=0 cause it's not a valid message) */
 335 static void queue_message_processing(struct afb_proto_ws *protows, char *data, size_t size, void (*processing)(int,void*))
 336 {
 337         struct binary *binary;
 338
 339         if (size) {
 340                 binary = malloc(sizeof *binary);
 341                 if (!binary) {
 342                         /* TODO process the problem */
 343                         errno = ENOMEM;
 344                 } else {
 345                         binary->protows = protows;
 346                         binary->rb.base = data;
 347                         binary->rb.head = data;
 348                         binary->rb.end = data + size;
 349                         if (!protows->queuing
 350                          || protows->queuing(protows, processing, binary) < 0)
 351                                 processing(0, binary);
 352                         return;
 353                 }
 354         }
 355         free(data);
 356 }
 357
 358 /******************* ws request part for server *****************/
 359
 360 void afb_proto_ws_call_addref(struct afb_proto_ws_call *call)
 361 {
 362         __atomic_add_fetch(&call->refcount, 1, __ATOMIC_RELAXED);
 363 }
 364
 365 void afb_proto_ws_call_unref(struct afb_proto_ws_call *call)
 366 {
 367         if (__atomic_sub_fetch(&call->refcount, 1, __ATOMIC_RELAXED))
 368                 return;
 369
 370         afb_proto_ws_unref(call->protows);
 371         free(call->buffer);
 372         free(call);
 373 }
 374
 375 int afb_proto_ws_call_reply(struct afb_proto_ws_call *call, struct json_object *obj, const char *error, const char *info)
 376 {
 377         int rc = -1;
 378         struct writebuf wb = { .count = 0 };
 379         struct afb_proto_ws *protows = call->protows;
 380
 381         if (writebuf_char(&wb, CHAR_FOR_REPLY)
 382          && writebuf_uint32(&wb, call->callid)
 383          && writebuf_nullstring(&wb, error)
 384          && writebuf_nullstring(&wb, info)
 385          && writebuf_object(&wb, obj)) {
 386                 pthread_mutex_lock(&protows->mutex);
 387                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 388                 pthread_mutex_unlock(&protows->mutex);
 389                 if (rc >= 0) {
 390                         rc = 0;
 391                         goto success;
 392                 }
 393         }
 394 success:
 395         return rc;
 396 }
 397
 398 int afb_proto_ws_call_subscribe(struct afb_proto_ws_call *call, const char *event_name, int event_id)
 399 {
 400         int rc = -1;
 401         struct writebuf wb = { .count = 0 };
 402         struct afb_proto_ws *protows = call->protows;
 403
 404         if (writebuf_char(&wb, CHAR_FOR_EVT_SUBSCRIBE)
 405          && writebuf_uint32(&wb, call->callid)
 406          && writebuf_uint32(&wb, (uint32_t)event_id)
 407          && writebuf_string(&wb, event_name)) {
 408                 pthread_mutex_lock(&protows->mutex);
 409                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 410                 pthread_mutex_unlock(&protows->mutex);
 411                 if (rc >= 0) {
 412                         rc = 0;
 413                         goto success;
 414                 }
 415         }
 416 success:
 417         return rc;
 418 }
 419
 420 int afb_proto_ws_call_unsubscribe(struct afb_proto_ws_call *call, const char *event_name, int event_id)
 421 {
 422         int rc = -1;
 423         struct writebuf wb = { .count = 0 };
 424         struct afb_proto_ws *protows = call->protows;
 425
 426         if (writebuf_char(&wb, CHAR_FOR_EVT_UNSUBSCRIBE)
 427          && writebuf_uint32(&wb, call->callid)
 428          && writebuf_uint32(&wb, (uint32_t)event_id)
 429          && writebuf_string(&wb, event_name)) {
 430                 pthread_mutex_lock(&protows->mutex);
 431                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 432                 pthread_mutex_unlock(&protows->mutex);
 433                 if (rc >= 0) {
 434                         rc = 0;
 435                         goto success;
 436                 }
 437         }
 438 success:
 439         return rc;
 440 }
 441
 442 /******************* client part **********************************/
 443
 444 /* search a memorized call */
 445 static struct client_call *client_call_search_locked(struct afb_proto_ws *protows, uint32_t callid)
 446 {
 447         struct client_call *call;
 448
 449         call = protows->calls;
 450         while (call != NULL && call->callid != callid)
 451                 call = call->next;
 452
 453         return call;
 454 }
 455
 456 static struct client_call *client_call_search_unlocked(struct afb_proto_ws *protows, uint32_t callid)
 457 {
 458         struct client_call *result;
 459
 460         pthread_mutex_lock(&protows->mutex);
 461         result = client_call_search_locked(protows, callid);
 462         pthread_mutex_unlock(&protows->mutex);
 463         return result;
 464 }
 465
 466 /* free and release the memorizing call */
 467 static void client_call_destroy(struct client_call *call)
 468 {
 469         struct client_call **prv;
 470         struct afb_proto_ws *protows = call->protows;
 471
 472         pthread_mutex_lock(&protows->mutex);
 473         prv = &call->protows->calls;
 474         while (*prv != NULL) {
 475                 if (*prv == call) {
 476                         *prv = call->next;
 477                         break;
 478                 }
 479                 prv = &(*prv)->next;
 480         }
 481         pthread_mutex_unlock(&protows->mutex);
 482         free(call);
 483 }
 484
 485 /* get event data from the message */
 486 static int client_msg_event_read(struct readbuf *rb, uint32_t *eventid, const char **name)
 487 {
 488         return readbuf_uint32(rb, eventid) && readbuf_string(rb, name, NULL);
 489 }
 490
 491 /* get event from the message */
 492 static int client_msg_call_get(struct afb_proto_ws *protows, struct readbuf *rb, struct client_call **call)
 493 {
 494         uint32_t callid;
 495
 496         /* get event data from the message */
 497         if (!readbuf_uint32(rb, &callid)) {
 498                 return 0;
 499         }
 500
 501         /* get the call */
 502         *call = client_call_search_unlocked(protows, callid);
 503         if (*call == NULL) {
 504                 return 0;
 505         }
 506
 507         return 1;
 508 }
 509
 510 /* adds an event */
 511 static void client_on_event_create(struct afb_proto_ws *protows, struct readbuf *rb)
 512 {
 513         const char *event_name;
 514         uint32_t event_id;
 515
 516         if (protows->client_itf->on_event_create && client_msg_event_read(rb, &event_id, &event_name))
 517                 protows->client_itf->on_event_create(protows->closure, event_name, (int)event_id);
 518         else
 519                 ERROR("Ignoring creation of event");
 520 }
 521
 522 /* removes an event */
 523 static void client_on_event_remove(struct afb_proto_ws *protows, struct readbuf *rb)
 524 {
 525         const char *event_name;
 526         uint32_t event_id;
 527
 528         if (protows->client_itf->on_event_remove && client_msg_event_read(rb, &event_id, &event_name))
 529                 protows->client_itf->on_event_remove(protows->closure, event_name, (int)event_id);
 530         else
 531                 ERROR("Ignoring deletion of event");
 532 }
 533
 534 /* subscribes an event */
 535 static void client_on_event_subscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 536 {
 537         const char *event_name;
 538         uint32_t event_id;
 539         struct client_call *call;
 540
 541         if (protows->client_itf->on_event_subscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 542                 protows->client_itf->on_event_subscribe(protows->closure, call->request, event_name, (int)event_id);
 543         else
 544                 ERROR("Ignoring subscription to event");
 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         else
 557                 ERROR("Ignoring unsubscription to event");
 558 }
 559
 560 /* receives broadcasted events */
 561 static void client_on_event_broadcast(struct afb_proto_ws *protows, struct readbuf *rb)
 562 {
 563         const char *event_name, *uuid;
 564         char hop;
 565         struct json_object *object;
 566
 567         if (protows->client_itf->on_event_broadcast && readbuf_string(rb, &event_name, NULL) && readbuf_object(rb, &object) && (uuid = readbuf_get(rb, 16)) && readbuf_char(rb, &hop))
 568                 protows->client_itf->on_event_broadcast(protows->closure, event_name, object, (unsigned char*)uuid, (uint8_t)hop);
 569         else
 570                 ERROR("Ignoring broadcast of event");
 571 }
 572
 573 /* pushs an event */
 574 static void client_on_event_push(struct afb_proto_ws *protows, struct readbuf *rb)
 575 {
 576         const char *event_name;
 577         uint32_t event_id;
 578         struct json_object *object;
 579
 580         if (protows->client_itf->on_event_push && client_msg_event_read(rb, &event_id, &event_name) && readbuf_object(rb, &object))
 581                 protows->client_itf->on_event_push(protows->closure, event_name, (int)event_id, object);
 582         else
 583                 ERROR("Ignoring push of event");
 584 }
 585
 586 static void client_on_reply(struct afb_proto_ws *protows, struct readbuf *rb)
 587 {
 588         struct client_call *call;
 589         struct json_object *object;
 590         const char *error, *info;
 591
 592         if (!client_msg_call_get(protows, rb, &call))
 593                 return;
 594
 595         if (readbuf_nullstring(rb, &error, NULL) && readbuf_nullstring(rb, &info, NULL) && readbuf_object(rb, &object)) {
 596                 protows->client_itf->on_reply(protows->closure, call->request, object, error, info);
 597         } else {
 598                 protows->client_itf->on_reply(protows->closure, call->request, NULL, "proto-error", "can't process success");
 599         }
 600         client_call_destroy(call);
 601 }
 602
 603 static void client_on_description(struct afb_proto_ws *protows, struct readbuf *rb)
 604 {
 605         uint32_t descid;
 606         struct client_describe *desc, **prv;
 607         struct json_object *object;
 608
 609         if (readbuf_uint32(rb, &descid)) {
 610                 pthread_mutex_lock(&protows->mutex);
 611                 prv = &protows->describes;
 612                 while ((desc = *prv) && desc->descid != descid)
 613                         prv = &desc->next;
 614                 if (!desc)
 615                         pthread_mutex_unlock(&protows->mutex);
 616                 else {
 617                         *prv = desc->next;
 618                         pthread_mutex_unlock(&protows->mutex);
 619                         if (!readbuf_object(rb, &object))
 620                                 object = NULL;
 621                         desc->callback(desc->closure, object);
 622                         free(desc);
 623                 }
 624         }
 625 }
 626
 627 /* callback when receiving binary data */
 628 static void client_on_binary_job(int sig, void *closure)
 629 {
 630         struct binary *binary = closure;
 631
 632         if (!sig) {
 633                 switch (*binary->rb.head++) {
 634                 case CHAR_FOR_REPLY: /* reply */
 635                         client_on_reply(binary->protows, &binary->rb);
 636                         break;
 637                 case CHAR_FOR_EVT_BROADCAST: /* broadcast */
 638                         client_on_event_broadcast(binary->protows, &binary->rb);
 639                         break;
 640                 case CHAR_FOR_EVT_ADD: /* creates the event */
 641                         client_on_event_create(binary->protows, &binary->rb);
 642                         break;
 643                 case CHAR_FOR_EVT_DEL: /* removes the event */
 644                         client_on_event_remove(binary->protows, &binary->rb);
 645                         break;
 646                 case CHAR_FOR_EVT_PUSH: /* pushs the event */
 647                         client_on_event_push(binary->protows, &binary->rb);
 648                         break;
 649                 case CHAR_FOR_EVT_SUBSCRIBE: /* subscribe event for a request */
 650                         client_on_event_subscribe(binary->protows, &binary->rb);
 651                         break;
 652                 case CHAR_FOR_EVT_UNSUBSCRIBE: /* unsubscribe event for a request */
 653                         client_on_event_unsubscribe(binary->protows, &binary->rb);
 654                         break;
 655                 case CHAR_FOR_DESCRIPTION: /* description */
 656                         client_on_description(binary->protows, &binary->rb);
 657                         break;
 658                 default: /* unexpected message */
 659                         /* TODO: close the connection */
 660                         break;
 661                 }
 662         }
 663         free(binary->rb.base);
 664         free(binary);
 665 }
 666
 667 /* callback when receiving binary data */
 668 static void client_on_binary(void *closure, char *data, size_t size)
 669 {
 670         struct afb_proto_ws *protows = closure;
 671
 672         queue_message_processing(protows, data, size, client_on_binary_job);
 673 }
 674
 675 int afb_proto_ws_client_call(
 676                 struct afb_proto_ws *protows,
 677                 const char *verb,
 678                 struct json_object *args,
 679                 const char *sessionid,
 680                 void *request,
 681                 const char *user_creds
 682 )
 683 {
 684         int rc = -1;
 685         struct client_call *call;
 686         struct writebuf wb = { .count = 0 };
 687
 688         /* allocate call data */
 689         call = malloc(sizeof *call);
 690         if (call == NULL) {
 691                 errno = ENOMEM;
 692                 return -1;
 693         }
 694         call->request = request;
 695
 696         /* init call data */
 697         pthread_mutex_lock(&protows->mutex);
 698         call->callid = ptr2id(call);
 699         while(client_call_search_locked(protows, call->callid) != NULL)
 700                 call->callid++;
 701         call->protows = protows;
 702         call->next = protows->calls;
 703         protows->calls = call;
 704         pthread_mutex_unlock(&protows->mutex);
 705
 706         /* creates the call message */
 707         if (!writebuf_char(&wb, CHAR_FOR_CALL)
 708          || !writebuf_uint32(&wb, call->callid)
 709          || !writebuf_string(&wb, verb)
 710          || !writebuf_string(&wb, sessionid)
 711          || !writebuf_object(&wb, args)
 712          || !writebuf_nullstring(&wb, user_creds)) {
 713                 errno = EINVAL;
 714                 goto clean;
 715         }
 716
 717         /* send */
 718         pthread_mutex_lock(&protows->mutex);
 719         rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 720         pthread_mutex_unlock(&protows->mutex);
 721         if (rc >= 0) {
 722                 rc = 0;
 723                 goto end;
 724         }
 725
 726 clean:
 727         client_call_destroy(call);
 728 end:
 729         return rc;
 730 }
 731
 732 /* get the description */
 733 int afb_proto_ws_client_describe(struct afb_proto_ws *protows, void (*callback)(void*, struct json_object*), void *closure)
 734 {
 735         struct client_describe *desc, *d;
 736         struct writebuf wb = { .count = 0 };
 737
 738         desc = malloc(sizeof *desc);
 739         if (!desc) {
 740                 errno = ENOMEM;
 741                 goto error;
 742         }
 743
 744         /* fill in stack the description of the task */
 745         pthread_mutex_lock(&protows->mutex);
 746         desc->descid = ptr2id(desc);
 747         d = protows->describes;
 748         while (d) {
 749                 if (d->descid != desc->descid)
 750                         d = d->next;
 751                 else {
 752                         desc->descid++;
 753                         d = protows->describes;
 754                 }
 755         }
 756         desc->callback = callback;
 757         desc->closure = closure;
 758         desc->protows = protows;
 759         desc->next = protows->describes;
 760         protows->describes = desc;
 761
 762         /* send */
 763         if (writebuf_char(&wb, CHAR_FOR_DESCRIBE)
 764          && writebuf_uint32(&wb, desc->descid)
 765          && afb_ws_binary_v(protows->ws, wb.iovec, wb.count) >= 0) {
 766                 pthread_mutex_unlock(&protows->mutex);
 767                 return 0;
 768         }
 769
 770         d = protows->describes;
 771         if (d == desc)
 772                 protows->describes = desc->next;
 773         else {
 774                 while(d && d->next != desc)
 775                         d = d->next;
 776                 if (d)
 777                         d->next = desc->next;
 778         }
 779         pthread_mutex_unlock(&protows->mutex);
 780         free(desc);
 781 error:
 782         /* TODO? callback(closure, NULL); */
 783         return -1;
 784 }
 785
 786 /******************* client description part for server *****************************/
 787
 788 /* on call, propagate it to the ws service */
 789 static void server_on_call(struct afb_proto_ws *protows, struct readbuf *rb)
 790 {
 791         struct afb_proto_ws_call *call;
 792         const char *uuid, *verb, *user_creds;
 793         uint32_t callid;
 794         size_t lenverb;
 795         struct json_object *object;
 796
 797         afb_proto_ws_addref(protows);
 798
 799         /* reads the call message data */
 800         if (!readbuf_uint32(rb, &callid)
 801          || !readbuf_string(rb, &verb, &lenverb)
 802          || !readbuf_string(rb, &uuid, NULL)
 803          || !readbuf_object(rb, &object)
 804          || !readbuf_nullstring(rb, &user_creds, NULL))
 805                 goto overflow;
 806
 807         /* create the request */
 808         call = malloc(sizeof *call);
 809         if (call == NULL)
 810                 goto out_of_memory;
 811
 812         call->protows = protows;
 813         call->callid = callid;
 814         call->refcount = 1;
 815         call->buffer = rb->base;
 816         rb->base = NULL; /* don't free the buffer */
 817
 818         protows->server_itf->on_call(protows->closure, call, verb, object, uuid, user_creds);
 819         return;
 820
 821 out_of_memory:
 822         json_object_put(object);
 823
 824 overflow:
 825         afb_proto_ws_unref(protows);
 826 }
 827
 828 static int server_send_description(struct afb_proto_ws *protows, uint32_t descid, struct json_object *descobj)
 829 {
 830         int rc;
 831         struct writebuf wb = { .count = 0 };
 832
 833         if (writebuf_char(&wb, CHAR_FOR_DESCRIPTION)
 834          && writebuf_uint32(&wb, descid)
 835          && writebuf_object(&wb, descobj)) {
 836                 pthread_mutex_lock(&protows->mutex);
 837                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 838                 pthread_mutex_unlock(&protows->mutex);
 839                 if (rc >= 0)
 840                         return 0;
 841         }
 842         return -1;
 843 }
 844
 845 int afb_proto_ws_describe_put(struct afb_proto_ws_describe *describe, struct json_object *description)
 846 {
 847         int rc = server_send_description(describe->protows, describe->descid, description);
 848         afb_proto_ws_unref(describe->protows);
 849         free(describe);
 850         return rc;
 851 }
 852
 853 /* on describe, propagate it to the ws service */
 854 static void server_on_describe(struct afb_proto_ws *protows, struct readbuf *rb)
 855 {
 856         uint32_t descid;
 857         struct afb_proto_ws_describe *desc;
 858
 859         /* reads the descid */
 860         if (readbuf_uint32(rb, &descid)) {
 861                 if (protows->server_itf->on_describe) {
 862                         /* create asynchronous job */
 863                         desc = malloc(sizeof *desc);
 864                         if (desc) {
 865                                 desc->descid = descid;
 866                                 desc->protows = protows;
 867                                 afb_proto_ws_addref(protows);
 868                                 protows->server_itf->on_describe(protows->closure, desc);
 869                                 return;
 870                         }
 871                 }
 872                 server_send_description(protows, descid, NULL);
 873         }
 874 }
 875
 876 /* callback when receiving binary data */
 877 static void server_on_binary_job(int sig, void *closure)
 878 {
 879         struct binary *binary = closure;
 880
 881         if (!sig) {
 882                 switch (*binary->rb.head++) {
 883                 case CHAR_FOR_CALL:
 884                         server_on_call(binary->protows, &binary->rb);
 885                         break;
 886                 case CHAR_FOR_DESCRIBE:
 887                         server_on_describe(binary->protows, &binary->rb);
 888                         break;
 889                 default: /* unexpected message */
 890                         /* TODO: close the connection */
 891                         break;
 892                 }
 893         }
 894         free(binary->rb.base);
 895         free(binary);
 896 }
 897
 898 static void server_on_binary(void *closure, char *data, size_t size)
 899 {
 900         struct afb_proto_ws *protows = closure;
 901
 902         queue_message_processing(protows, data, size, server_on_binary_job);
 903 }
 904
 905 /******************* server part: manage events **********************************/
 906
 907 static int server_event_send(struct afb_proto_ws *protows, char order, const char *event_name, int event_id, struct json_object *data)
 908 {
 909         struct writebuf wb = { .count = 0 };
 910         int rc;
 911
 912         if (writebuf_char(&wb, order)
 913          && writebuf_uint32(&wb, event_id)
 914          && writebuf_string(&wb, event_name)
 915          && (order != CHAR_FOR_EVT_PUSH || writebuf_object(&wb, data))) {
 916                 pthread_mutex_lock(&protows->mutex);
 917                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 918                 pthread_mutex_unlock(&protows->mutex);
 919                 if (rc >= 0)
 920                         return 0;
 921         }
 922         return -1;
 923 }
 924
 925 int afb_proto_ws_server_event_create(struct afb_proto_ws *protows, const char *event_name, int event_id)
 926 {
 927         return server_event_send(protows, CHAR_FOR_EVT_ADD, event_name, event_id, NULL);
 928 }
 929
 930 int afb_proto_ws_server_event_remove(struct afb_proto_ws *protows, const char *event_name, int event_id)
 931 {
 932         return server_event_send(protows, CHAR_FOR_EVT_DEL, event_name, event_id, NULL);
 933 }
 934
 935 int afb_proto_ws_server_event_push(struct afb_proto_ws *protows, const char *event_name, int event_id, struct json_object *data)
 936 {
 937         return server_event_send(protows, CHAR_FOR_EVT_PUSH, event_name, event_id, data);
 938 }
 939
 940 int afb_proto_ws_server_event_broadcast(struct afb_proto_ws *protows, const char *event_name, struct json_object *data, const unsigned char uuid[16], uint8_t hop)
 941 {
 942         struct writebuf wb = { .count = 0 };
 943         int rc;
 944
 945         if (!hop--)
 946                 return 0;
 947
 948         if (writebuf_char(&wb, CHAR_FOR_EVT_BROADCAST)
 949          && writebuf_string(&wb, event_name)
 950          && writebuf_object(&wb, data)
 951          && writebuf_put(&wb, uuid, 16)
 952          && writebuf_char(&wb, (char)hop)) {
 953                 pthread_mutex_lock(&protows->mutex);
 954                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 955                 pthread_mutex_unlock(&protows->mutex);
 956                 if (rc >= 0)
 957                         return 0;
 958         }
 959         return -1;
 960 }
 961
 962 /*****************************************************/
 963
 964 /* callback when receiving a hangup */
 965 static void on_hangup(void *closure)
 966 {
 967         struct afb_proto_ws *protows = closure;
 968         struct client_describe *cd, *ncd;
 969         struct client_call *call, *ncall;
 970
 971         ncd = __atomic_exchange_n(&protows->describes, NULL, __ATOMIC_RELAXED);
 972         ncall = __atomic_exchange_n(&protows->calls, NULL, __ATOMIC_RELAXED);
 973
 974         while (ncall) {
 975                 call= ncall;
 976                 ncall = call->next;
 977                 protows->client_itf->on_reply(protows->closure, call->request, NULL, "disconnected", "server hung up");
 978                 free(call);
 979         }
 980
 981         while (ncd) {
 982                 cd= ncd;
 983                 ncd = cd->next;
 984                 cd->callback(cd->closure, NULL);
 985                 free(cd);
 986         }
 987
 988         if (protows->fdev) {
 989                 fdev_unref(protows->fdev);
 990                 protows->fdev = 0;
 991                 if (protows->on_hangup)
 992                         protows->on_hangup(protows->closure);
 993         }
 994 }
 995
 996 /*****************************************************/
 997
 998 static const struct afb_ws_itf proto_ws_client_ws_itf =
 999 {
1000         .on_close = NULL,
1001         .on_text = NULL,
1002         .on_binary = client_on_binary,
1003         .on_error = NULL,
1004         .on_hangup = on_hangup
1005 };
1006
1007 static const struct afb_ws_itf server_ws_itf =
1008 {
1009         .on_close = NULL,
1010         .on_text = NULL,
1011         .on_binary = server_on_binary,
1012         .on_error = NULL,
1013         .on_hangup = on_hangup
1014 };
1015
1016 /*****************************************************/
1017
1018 static struct afb_proto_ws *afb_proto_ws_create(struct fdev *fdev, const struct afb_proto_ws_server_itf *itfs, const struct afb_proto_ws_client_itf *itfc, void *closure, const struct afb_ws_itf *itf)
1019 {
1020         struct afb_proto_ws *protows;
1021
1022         protows = calloc(1, sizeof *protows);
1023         if (protows == NULL)
1024                 errno = ENOMEM;
1025         else {
1026                 fcntl(fdev_fd(fdev), F_SETFD, FD_CLOEXEC);
1027                 fcntl(fdev_fd(fdev), F_SETFL, O_NONBLOCK);
1028                 protows->ws = afb_ws_create(fdev, itf, protows);
1029                 if (protows->ws != NULL) {
1030                         protows->fdev = fdev;
1031                         protows->refcount = 1;
1032                         protows->closure = closure;
1033                         protows->server_itf = itfs;
1034                         protows->client_itf = itfc;
1035                         pthread_mutex_init(&protows->mutex, NULL);
1036                         return protows;
1037                 }
1038                 free(protows);
1039         }
1040         return NULL;
1041 }
1042
1043 struct afb_proto_ws *afb_proto_ws_create_client(struct fdev *fdev, const struct afb_proto_ws_client_itf *itf, void *closure)
1044 {
1045         return afb_proto_ws_create(fdev, NULL, itf, closure, &proto_ws_client_ws_itf);
1046 }
1047
1048 struct afb_proto_ws *afb_proto_ws_create_server(struct fdev *fdev, const struct afb_proto_ws_server_itf *itf, void *closure)
1049 {
1050         return afb_proto_ws_create(fdev, itf, NULL, closure, &server_ws_itf);
1051 }
1052
1053 void afb_proto_ws_unref(struct afb_proto_ws *protows)
1054 {
1055         if (protows && !__atomic_sub_fetch(&protows->refcount, 1, __ATOMIC_RELAXED)) {
1056                 afb_proto_ws_hangup(protows);
1057                 afb_ws_destroy(protows->ws);
1058                 pthread_mutex_destroy(&protows->mutex);
1059                 free(protows);
1060         }
1061 }
1062
1063 void afb_proto_ws_addref(struct afb_proto_ws *protows)
1064 {
1065         __atomic_add_fetch(&protows->refcount, 1, __ATOMIC_RELAXED);
1066 }
1067
1068 int afb_proto_ws_is_client(struct afb_proto_ws *protows)
1069 {
1070         return !!protows->client_itf;
1071 }
1072
1073 int afb_proto_ws_is_server(struct afb_proto_ws *protows)
1074 {
1075         return !!protows->server_itf;
1076 }
1077
1078 void afb_proto_ws_hangup(struct afb_proto_ws *protows)
1079 {
1080         afb_ws_hangup(protows->ws);
1081 }
1082
1083 void afb_proto_ws_on_hangup(struct afb_proto_ws *protows, void (*on_hangup)(void *closure))
1084 {
1085         protows->on_hangup = on_hangup;
1086 }
1087
1088 void afb_proto_ws_set_queuing(struct afb_proto_ws *protows, int (*queuing)(struct afb_proto_ws*, void (*)(int,void*), void*))
1089 {
1090         protows->queuing = queuing;
1091 }