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         /* resource control */
 136         pthread_mutex_t mutex;
 137
 138         /* websocket */
 139         struct afb_ws *ws;
 140
 141         /* the client closure */
 142         void *closure;
 143
 144         /* the client side interface */
 145         const struct afb_proto_ws_client_itf *client_itf;
 146
 147         /* the server side interface */
 148         const struct afb_proto_ws_server_itf *server_itf;
 149
 150         /* emitted calls (client side) */
 151         struct client_call *calls;
 152
 153         /* pending description (client side) */
 154         struct client_describe *describes;
 155
 156         /* on hangup callback */
 157         void (*on_hangup)(void *closure);
 158
 159         /* queuing facility for processing messages */
 160         int (*queuing)(struct afb_proto_ws *proto, void (*process)(int s, void *c), void *closure);
 161 };
 162
 163 /******************* streaming objects **********************************/
 164
 165 #define WRITEBUF_COUNT_MAX  32
 166 struct writebuf
 167 {
 168         struct iovec iovec[WRITEBUF_COUNT_MAX];
 169         uint32_t uints[WRITEBUF_COUNT_MAX];
 170         int count;
 171 };
 172
 173 struct readbuf
 174 {
 175         char *base, *head, *end;
 176 };
 177
 178 struct binary
 179 {
 180         struct afb_proto_ws *protows;
 181         struct readbuf rb;
 182 };
 183
 184 /******************* common useful tools **********************************/
 185
 186 /**
 187  * translate a pointer to some integer
 188  * @param ptr the pointer to translate
 189  * @return an integer
 190  */
 191 static inline uint32_t ptr2id(void *ptr)
 192 {
 193         return (uint32_t)(((intptr_t)ptr) >> 6);
 194 }
 195
 196 /******************* serialisation part **********************************/
 197
 198 static char *readbuf_get(struct readbuf *rb, uint32_t length)
 199 {
 200         char *before = rb->head;
 201         char *after = before + length;
 202         if (after > rb->end)
 203                 return 0;
 204         rb->head = after;
 205         return before;
 206 }
 207
 208 __attribute__((unused))
 209 static int readbuf_char(struct readbuf *rb, char *value)
 210 {
 211         if (rb->head >= rb->end)
 212                 return 0;
 213         *value = *rb->head++;
 214         return 1;
 215 }
 216
 217 static int readbuf_uint32(struct readbuf *rb, uint32_t *value)
 218 {
 219         char *after = rb->head + sizeof *value;
 220         if (after > rb->end)
 221                 return 0;
 222         memcpy(value, rb->head, sizeof *value);
 223         rb->head = after;
 224         *value = le32toh(*value);
 225         return 1;
 226 }
 227
 228 static int _readbuf_string_(struct readbuf *rb, const char **value, size_t *length, int nulok)
 229 {
 230         uint32_t len;
 231         if (!readbuf_uint32(rb, &len))
 232                 return 0;
 233         if (!len) {
 234                 if (!nulok)
 235                         return 0;
 236                 *value = NULL;
 237                 if (length)
 238                         *length = 0;
 239                 return 1;
 240         }
 241         if (length)
 242                 *length = (size_t)(len - 1);
 243         return (*value = readbuf_get(rb, len)) != NULL &&  rb->head[-1] == 0;
 244 }
 245
 246
 247 static int readbuf_string(struct readbuf *rb, const char **value, size_t *length)
 248 {
 249         return _readbuf_string_(rb, value, length, 0);
 250 }
 251
 252 static int readbuf_nullstring(struct readbuf *rb, const char **value, size_t *length)
 253 {
 254         return _readbuf_string_(rb, value, length, 1);
 255 }
 256
 257 static int readbuf_object(struct readbuf *rb, struct json_object **object)
 258 {
 259         const char *string;
 260         struct json_object *o;
 261         enum json_tokener_error jerr;
 262         int rc = readbuf_string(rb, &string, NULL);
 263         if (rc) {
 264                 o = json_tokener_parse_verbose(string, &jerr);
 265                 if (jerr != json_tokener_success)
 266                         o = json_object_new_string(string);
 267                 *object = o;
 268         }
 269         return rc;
 270 }
 271
 272 static int writebuf_put(struct writebuf *wb, const void *value, size_t length)
 273 {
 274         int i = wb->count;
 275         if (i == WRITEBUF_COUNT_MAX)
 276                 return 0;
 277         wb->iovec[i].iov_base = (void*)value;
 278         wb->iovec[i].iov_len = length;
 279         wb->count = i + 1;
 280         return 1;
 281 }
 282
 283 static int writebuf_char(struct writebuf *wb, char value)
 284 {
 285         int i = wb->count;
 286         if (i == WRITEBUF_COUNT_MAX)
 287                 return 0;
 288         *(char*)&wb->uints[i] = value;
 289         wb->iovec[i].iov_base = &wb->uints[i];
 290         wb->iovec[i].iov_len = 1;
 291         wb->count = i + 1;
 292         return 1;
 293 }
 294
 295 static int writebuf_uint32(struct writebuf *wb, uint32_t value)
 296 {
 297         int i = wb->count;
 298         if (i == WRITEBUF_COUNT_MAX)
 299                 return 0;
 300         wb->uints[i] = htole32(value);
 301         wb->iovec[i].iov_base = &wb->uints[i];
 302         wb->iovec[i].iov_len = sizeof wb->uints[i];
 303         wb->count = i + 1;
 304         return 1;
 305 }
 306
 307 static int writebuf_string_length(struct writebuf *wb, const char *value, size_t length)
 308 {
 309         uint32_t len = (uint32_t)++length;
 310         return (size_t)len == length && len && writebuf_uint32(wb, len) && writebuf_put(wb, value, length);
 311 }
 312
 313 static int writebuf_string(struct writebuf *wb, const char *value)
 314 {
 315         return writebuf_string_length(wb, value, strlen(value));
 316 }
 317
 318 static int writebuf_nullstring(struct writebuf *wb, const char *value)
 319 {
 320         return value ? writebuf_string_length(wb, value, strlen(value)) : writebuf_uint32(wb, 0);
 321 }
 322
 323 static int writebuf_object(struct writebuf *wb, struct json_object *object)
 324 {
 325         const char *string = json_object_to_json_string_ext(object, JSON_C_TO_STRING_PLAIN);
 326         return string != NULL && writebuf_string(wb, string);
 327 }
 328
 329 /******************* queuing of messages *****************/
 330
 331 /* queue the processing of the received message (except if size=0 cause it's not a valid message) */
 332 static void queue_message_processing(struct afb_proto_ws *protows, char *data, size_t size, void (*processing)(int,void*))
 333 {
 334         struct binary *binary;
 335
 336         if (size) {
 337                 binary = malloc(sizeof *binary);
 338                 if (!binary) {
 339                         /* TODO process the problem */
 340                         errno = ENOMEM;
 341                 } else {
 342                         binary->protows = protows;
 343                         binary->rb.base = data;
 344                         binary->rb.head = data;
 345                         binary->rb.end = data + size;
 346                         if (!protows->queuing
 347                          || protows->queuing(protows, processing, binary) < 0)
 348                                 processing(0, binary);
 349                         return;
 350                 }
 351         }
 352         free(data);
 353 }
 354
 355 /******************* ws request part for server *****************/
 356
 357 void afb_proto_ws_call_addref(struct afb_proto_ws_call *call)
 358 {
 359         __atomic_add_fetch(&call->refcount, 1, __ATOMIC_RELAXED);
 360 }
 361
 362 void afb_proto_ws_call_unref(struct afb_proto_ws_call *call)
 363 {
 364         if (__atomic_sub_fetch(&call->refcount, 1, __ATOMIC_RELAXED))
 365                 return;
 366
 367         afb_proto_ws_unref(call->protows);
 368         free(call->buffer);
 369         free(call);
 370 }
 371
 372 int afb_proto_ws_call_reply(struct afb_proto_ws_call *call, struct json_object *obj, const char *error, const char *info)
 373 {
 374         int rc = -1;
 375         struct writebuf wb = { .count = 0 };
 376         struct afb_proto_ws *protows = call->protows;
 377
 378         if (writebuf_char(&wb, CHAR_FOR_REPLY)
 379          && writebuf_uint32(&wb, call->callid)
 380          && writebuf_nullstring(&wb, error)
 381          && writebuf_nullstring(&wb, info)
 382          && writebuf_object(&wb, obj)) {
 383                 pthread_mutex_lock(&protows->mutex);
 384                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 385                 pthread_mutex_unlock(&protows->mutex);
 386                 if (rc >= 0) {
 387                         rc = 0;
 388                         goto success;
 389                 }
 390         }
 391 success:
 392         return rc;
 393 }
 394
 395 int afb_proto_ws_call_subscribe(struct afb_proto_ws_call *call, const char *event_name, int event_id)
 396 {
 397         int rc = -1;
 398         struct writebuf wb = { .count = 0 };
 399         struct afb_proto_ws *protows = call->protows;
 400
 401         if (writebuf_char(&wb, CHAR_FOR_EVT_SUBSCRIBE)
 402          && writebuf_uint32(&wb, call->callid)
 403          && writebuf_uint32(&wb, (uint32_t)event_id)
 404          && writebuf_string(&wb, event_name)) {
 405                 pthread_mutex_lock(&protows->mutex);
 406                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 407                 pthread_mutex_unlock(&protows->mutex);
 408                 if (rc >= 0) {
 409                         rc = 0;
 410                         goto success;
 411                 }
 412         }
 413 success:
 414         return rc;
 415 }
 416
 417 int afb_proto_ws_call_unsubscribe(struct afb_proto_ws_call *call, const char *event_name, int event_id)
 418 {
 419         int rc = -1;
 420         struct writebuf wb = { .count = 0 };
 421         struct afb_proto_ws *protows = call->protows;
 422
 423         if (writebuf_char(&wb, CHAR_FOR_EVT_UNSUBSCRIBE)
 424          && writebuf_uint32(&wb, call->callid)
 425          && writebuf_uint32(&wb, (uint32_t)event_id)
 426          && writebuf_string(&wb, event_name)) {
 427                 pthread_mutex_lock(&protows->mutex);
 428                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 429                 pthread_mutex_unlock(&protows->mutex);
 430                 if (rc >= 0) {
 431                         rc = 0;
 432                         goto success;
 433                 }
 434         }
 435 success:
 436         return rc;
 437 }
 438
 439 /******************* client part **********************************/
 440
 441 /* search a memorized call */
 442 static struct client_call *client_call_search_locked(struct afb_proto_ws *protows, uint32_t callid)
 443 {
 444         struct client_call *call;
 445
 446         call = protows->calls;
 447         while (call != NULL && call->callid != callid)
 448                 call = call->next;
 449
 450         return call;
 451 }
 452
 453 static struct client_call *client_call_search_unlocked(struct afb_proto_ws *protows, uint32_t callid)
 454 {
 455         struct client_call *result;
 456
 457         pthread_mutex_lock(&protows->mutex);
 458         result = client_call_search_locked(protows, callid);
 459         pthread_mutex_unlock(&protows->mutex);
 460         return result;
 461 }
 462
 463 /* free and release the memorizing call */
 464 static void client_call_destroy(struct client_call *call)
 465 {
 466         struct client_call **prv;
 467         struct afb_proto_ws *protows = call->protows;
 468
 469         pthread_mutex_lock(&protows->mutex);
 470         prv = &call->protows->calls;
 471         while (*prv != NULL) {
 472                 if (*prv == call) {
 473                         *prv = call->next;
 474                         break;
 475                 }
 476                 prv = &(*prv)->next;
 477         }
 478         pthread_mutex_unlock(&protows->mutex);
 479         free(call);
 480 }
 481
 482 /* get event data from the message */
 483 static int client_msg_event_read(struct readbuf *rb, uint32_t *eventid, const char **name)
 484 {
 485         return readbuf_uint32(rb, eventid) && readbuf_string(rb, name, NULL);
 486 }
 487
 488 /* get event from the message */
 489 static int client_msg_call_get(struct afb_proto_ws *protows, struct readbuf *rb, struct client_call **call)
 490 {
 491         uint32_t callid;
 492
 493         /* get event data from the message */
 494         if (!readbuf_uint32(rb, &callid)) {
 495                 return 0;
 496         }
 497
 498         /* get the call */
 499         *call = client_call_search_unlocked(protows, callid);
 500         if (*call == NULL) {
 501                 return 0;
 502         }
 503
 504         return 1;
 505 }
 506
 507 /* adds an event */
 508 static void client_on_event_create(struct afb_proto_ws *protows, struct readbuf *rb)
 509 {
 510         const char *event_name;
 511         uint32_t event_id;
 512
 513         if (protows->client_itf->on_event_create && client_msg_event_read(rb, &event_id, &event_name))
 514                 protows->client_itf->on_event_create(protows->closure, event_name, (int)event_id);
 515         else
 516                 ERROR("Ignoring creation of event");
 517 }
 518
 519 /* removes an event */
 520 static void client_on_event_remove(struct afb_proto_ws *protows, struct readbuf *rb)
 521 {
 522         const char *event_name;
 523         uint32_t event_id;
 524
 525         if (protows->client_itf->on_event_remove && client_msg_event_read(rb, &event_id, &event_name))
 526                 protows->client_itf->on_event_remove(protows->closure, event_name, (int)event_id);
 527         else
 528                 ERROR("Ignoring deletion of event");
 529 }
 530
 531 /* subscribes an event */
 532 static void client_on_event_subscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 533 {
 534         const char *event_name;
 535         uint32_t event_id;
 536         struct client_call *call;
 537
 538         if (protows->client_itf->on_event_subscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 539                 protows->client_itf->on_event_subscribe(protows->closure, call->request, event_name, (int)event_id);
 540         else
 541                 ERROR("Ignoring subscription to event");
 542 }
 543
 544 /* unsubscribes an event */
 545 static void client_on_event_unsubscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 546 {
 547         const char *event_name;
 548         uint32_t event_id;
 549         struct client_call *call;
 550
 551         if (protows->client_itf->on_event_unsubscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 552                 protows->client_itf->on_event_unsubscribe(protows->closure, call->request, event_name, (int)event_id);
 553         else
 554                 ERROR("Ignoring unsubscription to event");
 555 }
 556
 557 /* receives broadcasted events */
 558 static void client_on_event_broadcast(struct afb_proto_ws *protows, struct readbuf *rb)
 559 {
 560         const char *event_name, *uuid;
 561         char hop;
 562         struct json_object *object;
 563
 564         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))
 565                 protows->client_itf->on_event_broadcast(protows->closure, event_name, object, (unsigned char*)uuid, (uint8_t)hop);
 566         else
 567                 ERROR("Ignoring broadcast of event");
 568 }
 569
 570 /* pushs an event */
 571 static void client_on_event_push(struct afb_proto_ws *protows, struct readbuf *rb)
 572 {
 573         const char *event_name;
 574         uint32_t event_id;
 575         struct json_object *object;
 576
 577         if (protows->client_itf->on_event_push && client_msg_event_read(rb, &event_id, &event_name) && readbuf_object(rb, &object))
 578                 protows->client_itf->on_event_push(protows->closure, event_name, (int)event_id, object);
 579         else
 580                 ERROR("Ignoring push of event");
 581 }
 582
 583 static void client_on_reply(struct afb_proto_ws *protows, struct readbuf *rb)
 584 {
 585         struct client_call *call;
 586         struct json_object *object;
 587         const char *error, *info;
 588
 589         if (!client_msg_call_get(protows, rb, &call))
 590                 return;
 591
 592         if (readbuf_nullstring(rb, &error, NULL) && readbuf_nullstring(rb, &info, NULL) && readbuf_object(rb, &object)) {
 593                 protows->client_itf->on_reply(protows->closure, call->request, object, error, info);
 594         } else {
 595                 protows->client_itf->on_reply(protows->closure, call->request, NULL, "proto-error", "can't process success");
 596         }
 597         client_call_destroy(call);
 598 }
 599
 600 static void client_on_description(struct afb_proto_ws *protows, struct readbuf *rb)
 601 {
 602         uint32_t descid;
 603         struct client_describe *desc, **prv;
 604         struct json_object *object;
 605
 606         if (readbuf_uint32(rb, &descid)) {
 607                 pthread_mutex_lock(&protows->mutex);
 608                 prv = &protows->describes;
 609                 while ((desc = *prv) && desc->descid != descid)
 610                         prv = &desc->next;
 611                 if (!desc)
 612                         pthread_mutex_unlock(&protows->mutex);
 613                 else {
 614                         *prv = desc->next;
 615                         pthread_mutex_unlock(&protows->mutex);
 616                         if (!readbuf_object(rb, &object))
 617                                 object = NULL;
 618                         desc->callback(desc->closure, object);
 619                         free(desc);
 620                 }
 621         }
 622 }
 623
 624 /* callback when receiving binary data */
 625 static void client_on_binary_job(int sig, void *closure)
 626 {
 627         struct binary *binary = closure;
 628
 629         if (!sig) {
 630                 switch (*binary->rb.head++) {
 631                 case CHAR_FOR_REPLY: /* reply */
 632                         client_on_reply(binary->protows, &binary->rb);
 633                         break;
 634                 case CHAR_FOR_EVT_BROADCAST: /* broadcast */
 635                         client_on_event_broadcast(binary->protows, &binary->rb);
 636                         break;
 637                 case CHAR_FOR_EVT_ADD: /* creates the event */
 638                         client_on_event_create(binary->protows, &binary->rb);
 639                         break;
 640                 case CHAR_FOR_EVT_DEL: /* removes the event */
 641                         client_on_event_remove(binary->protows, &binary->rb);
 642                         break;
 643                 case CHAR_FOR_EVT_PUSH: /* pushs the event */
 644                         client_on_event_push(binary->protows, &binary->rb);
 645                         break;
 646                 case CHAR_FOR_EVT_SUBSCRIBE: /* subscribe event for a request */
 647                         client_on_event_subscribe(binary->protows, &binary->rb);
 648                         break;
 649                 case CHAR_FOR_EVT_UNSUBSCRIBE: /* unsubscribe event for a request */
 650                         client_on_event_unsubscribe(binary->protows, &binary->rb);
 651                         break;
 652                 case CHAR_FOR_DESCRIPTION: /* description */
 653                         client_on_description(binary->protows, &binary->rb);
 654                         break;
 655                 default: /* unexpected message */
 656                         /* TODO: close the connection */
 657                         break;
 658                 }
 659         }
 660         free(binary->rb.base);
 661         free(binary);
 662 }
 663
 664 /* callback when receiving binary data */
 665 static void client_on_binary(void *closure, char *data, size_t size)
 666 {
 667         struct afb_proto_ws *protows = closure;
 668
 669         queue_message_processing(protows, data, size, client_on_binary_job);
 670 }
 671
 672 int afb_proto_ws_client_call(
 673                 struct afb_proto_ws *protows,
 674                 const char *verb,
 675                 struct json_object *args,
 676                 const char *sessionid,
 677                 void *request,
 678                 const char *user_creds
 679 )
 680 {
 681         int rc = -1;
 682         struct client_call *call;
 683         struct writebuf wb = { .count = 0 };
 684
 685         /* allocate call data */
 686         call = malloc(sizeof *call);
 687         if (call == NULL) {
 688                 errno = ENOMEM;
 689                 return -1;
 690         }
 691         call->request = request;
 692
 693         /* init call data */
 694         pthread_mutex_lock(&protows->mutex);
 695         call->callid = ptr2id(call);
 696         while(client_call_search_locked(protows, call->callid) != NULL)
 697                 call->callid++;
 698         call->protows = protows;
 699         call->next = protows->calls;
 700         protows->calls = call;
 701         pthread_mutex_unlock(&protows->mutex);
 702
 703         /* creates the call message */
 704         if (!writebuf_char(&wb, CHAR_FOR_CALL)
 705          || !writebuf_uint32(&wb, call->callid)
 706          || !writebuf_string(&wb, verb)
 707          || !writebuf_string(&wb, sessionid)
 708          || !writebuf_object(&wb, args)
 709          || !writebuf_nullstring(&wb, user_creds)) {
 710                 errno = EINVAL;
 711                 goto clean;
 712         }
 713
 714         /* send */
 715         pthread_mutex_lock(&protows->mutex);
 716         rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 717         pthread_mutex_unlock(&protows->mutex);
 718         if (rc >= 0) {
 719                 rc = 0;
 720                 goto end;
 721         }
 722
 723 clean:
 724         client_call_destroy(call);
 725 end:
 726         return rc;
 727 }
 728
 729 /* get the description */
 730 int afb_proto_ws_client_describe(struct afb_proto_ws *protows, void (*callback)(void*, struct json_object*), void *closure)
 731 {
 732         struct client_describe *desc, *d;
 733         struct writebuf wb = { .count = 0 };
 734
 735         desc = malloc(sizeof *desc);
 736         if (!desc) {
 737                 errno = ENOMEM;
 738                 goto error;
 739         }
 740
 741         /* fill in stack the description of the task */
 742         pthread_mutex_lock(&protows->mutex);
 743         desc->descid = ptr2id(desc);
 744         d = protows->describes;
 745         while (d) {
 746                 if (d->descid != desc->descid)
 747                         d = d->next;
 748                 else {
 749                         desc->descid++;
 750                         d = protows->describes;
 751                 }
 752         }
 753         desc->callback = callback;
 754         desc->closure = closure;
 755         desc->protows = protows;
 756         desc->next = protows->describes;
 757         protows->describes = desc;
 758
 759         /* send */
 760         if (writebuf_char(&wb, CHAR_FOR_DESCRIBE)
 761          && writebuf_uint32(&wb, desc->descid)
 762          && afb_ws_binary_v(protows->ws, wb.iovec, wb.count) >= 0) {
 763                 pthread_mutex_unlock(&protows->mutex);
 764                 return 0;
 765         }
 766
 767         d = protows->describes;
 768         if (d == desc)
 769                 protows->describes = desc->next;
 770         else {
 771                 while(d && d->next != desc)
 772                         d = d->next;
 773                 if (d)
 774                         d->next = desc->next;
 775         }
 776         pthread_mutex_unlock(&protows->mutex);
 777         free(desc);
 778 error:
 779         /* TODO? callback(closure, NULL); */
 780         return -1;
 781 }
 782
 783 /******************* client description part for server *****************************/
 784
 785 /* on call, propagate it to the ws service */
 786 static void server_on_call(struct afb_proto_ws *protows, struct readbuf *rb)
 787 {
 788         struct afb_proto_ws_call *call;
 789         const char *uuid, *verb, *user_creds;
 790         uint32_t callid;
 791         size_t lenverb;
 792         struct json_object *object;
 793
 794         afb_proto_ws_addref(protows);
 795
 796         /* reads the call message data */
 797         if (!readbuf_uint32(rb, &callid)
 798          || !readbuf_string(rb, &verb, &lenverb)
 799          || !readbuf_string(rb, &uuid, NULL)
 800          || !readbuf_object(rb, &object)
 801          || !readbuf_nullstring(rb, &user_creds, NULL))
 802                 goto overflow;
 803
 804         /* create the request */
 805         call = malloc(sizeof *call);
 806         if (call == NULL)
 807                 goto out_of_memory;
 808
 809         call->protows = protows;
 810         call->callid = callid;
 811         call->refcount = 1;
 812         call->buffer = rb->base;
 813         rb->base = NULL; /* don't free the buffer */
 814
 815         protows->server_itf->on_call(protows->closure, call, verb, object, uuid, user_creds);
 816         return;
 817
 818 out_of_memory:
 819         json_object_put(object);
 820
 821 overflow:
 822         afb_proto_ws_unref(protows);
 823 }
 824
 825 static int server_send_description(struct afb_proto_ws *protows, uint32_t descid, struct json_object *descobj)
 826 {
 827         int rc;
 828         struct writebuf wb = { .count = 0 };
 829
 830         if (writebuf_char(&wb, CHAR_FOR_DESCRIPTION)
 831          && writebuf_uint32(&wb, descid)
 832          && writebuf_object(&wb, descobj)) {
 833                 pthread_mutex_lock(&protows->mutex);
 834                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 835                 pthread_mutex_unlock(&protows->mutex);
 836                 if (rc >= 0)
 837                         return 0;
 838         }
 839         return -1;
 840 }
 841
 842 int afb_proto_ws_describe_put(struct afb_proto_ws_describe *describe, struct json_object *description)
 843 {
 844         int rc = server_send_description(describe->protows, describe->descid, description);
 845         afb_proto_ws_unref(describe->protows);
 846         free(describe);
 847         return rc;
 848 }
 849
 850 /* on describe, propagate it to the ws service */
 851 static void server_on_describe(struct afb_proto_ws *protows, struct readbuf *rb)
 852 {
 853         uint32_t descid;
 854         struct afb_proto_ws_describe *desc;
 855
 856         /* reads the descid */
 857         if (readbuf_uint32(rb, &descid)) {
 858                 if (protows->server_itf->on_describe) {
 859                         /* create asynchronous job */
 860                         desc = malloc(sizeof *desc);
 861                         if (desc) {
 862                                 desc->descid = descid;
 863                                 desc->protows = protows;
 864                                 afb_proto_ws_addref(protows);
 865                                 protows->server_itf->on_describe(protows->closure, desc);
 866                                 return;
 867                         }
 868                 }
 869                 server_send_description(protows, descid, NULL);
 870         }
 871 }
 872
 873 /* callback when receiving binary data */
 874 static void server_on_binary_job(int sig, void *closure)
 875 {
 876         struct binary *binary = closure;
 877
 878         if (!sig) {
 879                 switch (*binary->rb.head++) {
 880                 case CHAR_FOR_CALL:
 881                         server_on_call(binary->protows, &binary->rb);
 882                         break;
 883                 case CHAR_FOR_DESCRIBE:
 884                         server_on_describe(binary->protows, &binary->rb);
 885                         break;
 886                 default: /* unexpected message */
 887                         /* TODO: close the connection */
 888                         break;
 889                 }
 890         }
 891         free(binary->rb.base);
 892         free(binary);
 893 }
 894
 895 static void server_on_binary(void *closure, char *data, size_t size)
 896 {
 897         struct afb_proto_ws *protows = closure;
 898
 899         queue_message_processing(protows, data, size, server_on_binary_job);
 900 }
 901
 902 /******************* server part: manage events **********************************/
 903
 904 static int server_event_send(struct afb_proto_ws *protows, char order, const char *event_name, int event_id, struct json_object *data)
 905 {
 906         struct writebuf wb = { .count = 0 };
 907         int rc;
 908
 909         if (writebuf_char(&wb, order)
 910          && writebuf_uint32(&wb, event_id)
 911          && writebuf_string(&wb, event_name)
 912          && (order != CHAR_FOR_EVT_PUSH || writebuf_object(&wb, data))) {
 913                 pthread_mutex_lock(&protows->mutex);
 914                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 915                 pthread_mutex_unlock(&protows->mutex);
 916                 if (rc >= 0)
 917                         return 0;
 918         }
 919         return -1;
 920 }
 921
 922 int afb_proto_ws_server_event_create(struct afb_proto_ws *protows, const char *event_name, int event_id)
 923 {
 924         return server_event_send(protows, CHAR_FOR_EVT_ADD, event_name, event_id, NULL);
 925 }
 926
 927 int afb_proto_ws_server_event_remove(struct afb_proto_ws *protows, const char *event_name, int event_id)
 928 {
 929         return server_event_send(protows, CHAR_FOR_EVT_DEL, event_name, event_id, NULL);
 930 }
 931
 932 int afb_proto_ws_server_event_push(struct afb_proto_ws *protows, const char *event_name, int event_id, struct json_object *data)
 933 {
 934         return server_event_send(protows, CHAR_FOR_EVT_PUSH, event_name, event_id, data);
 935 }
 936
 937 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)
 938 {
 939         struct writebuf wb = { .count = 0 };
 940         int rc;
 941
 942         if (!hop--)
 943                 return 0;
 944
 945         if (writebuf_char(&wb, CHAR_FOR_EVT_BROADCAST)
 946          && writebuf_string(&wb, event_name)
 947          && writebuf_object(&wb, data)
 948          && writebuf_put(&wb, uuid, 16)
 949          && writebuf_char(&wb, (char)hop)) {
 950                 pthread_mutex_lock(&protows->mutex);
 951                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 952                 pthread_mutex_unlock(&protows->mutex);
 953                 if (rc >= 0)
 954                         return 0;
 955         }
 956         return -1;
 957 }
 958
 959 /*****************************************************/
 960
 961 /* callback when receiving a hangup */
 962 static void on_hangup(void *closure)
 963 {
 964         struct afb_proto_ws *protows = closure;
 965         struct client_describe *cd, *ncd;
 966         struct client_call *call, *ncall;
 967
 968         ncd = __atomic_exchange_n(&protows->describes, NULL, __ATOMIC_RELAXED);
 969         ncall = __atomic_exchange_n(&protows->calls, NULL, __ATOMIC_RELAXED);
 970
 971         while (ncall) {
 972                 call= ncall;
 973                 ncall = call->next;
 974                 protows->client_itf->on_reply(protows->closure, call->request, NULL, "disconnected", "server hung up");
 975                 free(call);
 976         }
 977
 978         while (ncd) {
 979                 cd= ncd;
 980                 ncd = cd->next;
 981                 cd->callback(cd->closure, NULL);
 982                 free(cd);
 983         }
 984
 985         if (protows->ws) {
 986                 afb_ws_destroy(protows->ws);
 987                 protows->ws = 0;
 988                 if (protows->on_hangup)
 989                         protows->on_hangup(protows->closure);
 990         }
 991 }
 992
 993 /*****************************************************/
 994
 995 static const struct afb_ws_itf proto_ws_client_ws_itf =
 996 {
 997         .on_close = NULL,
 998         .on_text = NULL,
 999         .on_binary = client_on_binary,
1000         .on_error = NULL,
1001         .on_hangup = on_hangup
1002 };
1003
1004 static const struct afb_ws_itf server_ws_itf =
1005 {
1006         .on_close = NULL,
1007         .on_text = NULL,
1008         .on_binary = server_on_binary,
1009         .on_error = NULL,
1010         .on_hangup = on_hangup
1011 };
1012
1013 /*****************************************************/
1014
1015 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)
1016 {
1017         struct afb_proto_ws *protows;
1018
1019         protows = calloc(1, sizeof *protows);
1020         if (protows == NULL)
1021                 errno = ENOMEM;
1022         else {
1023                 fcntl(fdev_fd(fdev), F_SETFD, FD_CLOEXEC);
1024                 fcntl(fdev_fd(fdev), F_SETFL, O_NONBLOCK);
1025                 protows->ws = afb_ws_create(fdev, itf, protows);
1026                 if (protows->ws != NULL) {
1027                         protows->refcount = 1;
1028                         protows->closure = closure;
1029                         protows->server_itf = itfs;
1030                         protows->client_itf = itfc;
1031                         pthread_mutex_init(&protows->mutex, NULL);
1032                         return protows;
1033                 }
1034                 free(protows);
1035         }
1036         return NULL;
1037 }
1038
1039 struct afb_proto_ws *afb_proto_ws_create_client(struct fdev *fdev, const struct afb_proto_ws_client_itf *itf, void *closure)
1040 {
1041         return afb_proto_ws_create(fdev, NULL, itf, closure, &proto_ws_client_ws_itf);
1042 }
1043
1044 struct afb_proto_ws *afb_proto_ws_create_server(struct fdev *fdev, const struct afb_proto_ws_server_itf *itf, void *closure)
1045 {
1046         return afb_proto_ws_create(fdev, itf, NULL, closure, &server_ws_itf);
1047 }
1048
1049 void afb_proto_ws_unref(struct afb_proto_ws *protows)
1050 {
1051         if (protows && !__atomic_sub_fetch(&protows->refcount, 1, __ATOMIC_RELAXED)) {
1052                 afb_proto_ws_hangup(protows);
1053                 pthread_mutex_destroy(&protows->mutex);
1054                 free(protows);
1055         }
1056 }
1057
1058 void afb_proto_ws_addref(struct afb_proto_ws *protows)
1059 {
1060         __atomic_add_fetch(&protows->refcount, 1, __ATOMIC_RELAXED);
1061 }
1062
1063 int afb_proto_ws_is_client(struct afb_proto_ws *protows)
1064 {
1065         return !!protows->client_itf;
1066 }
1067
1068 int afb_proto_ws_is_server(struct afb_proto_ws *protows)
1069 {
1070         return !!protows->server_itf;
1071 }
1072
1073 void afb_proto_ws_hangup(struct afb_proto_ws *protows)
1074 {
1075         if (protows->ws)
1076                 afb_ws_hangup(protows->ws);
1077 }
1078
1079 void afb_proto_ws_on_hangup(struct afb_proto_ws *protows, void (*on_hangup)(void *closure))
1080 {
1081         protows->on_hangup = on_hangup;
1082 }
1083
1084 void afb_proto_ws_set_queuing(struct afb_proto_ws *protows, int (*queuing)(struct afb_proto_ws*, void (*)(int,void*), void*))
1085 {
1086         protows->queuing = queuing;
1087 }