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 "jobs.h"
  39 #include "fdev.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)(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(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 }
 519
 520 /* removes an event */
 521 static void client_on_event_remove(struct afb_proto_ws *protows, struct readbuf *rb)
 522 {
 523         const char *event_name;
 524         uint32_t event_id;
 525
 526         if (protows->client_itf->on_event_remove && client_msg_event_read(rb, &event_id, &event_name))
 527                 protows->client_itf->on_event_remove(protows->closure, event_name, (int)event_id);
 528 }
 529
 530 /* subscribes an event */
 531 static void client_on_event_subscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 532 {
 533         const char *event_name;
 534         uint32_t event_id;
 535         struct client_call *call;
 536
 537         if (protows->client_itf->on_event_subscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 538                 protows->client_itf->on_event_subscribe(protows->closure, call->request, event_name, (int)event_id);
 539 }
 540
 541 /* unsubscribes an event */
 542 static void client_on_event_unsubscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 543 {
 544         const char *event_name;
 545         uint32_t event_id;
 546         struct client_call *call;
 547
 548         if (protows->client_itf->on_event_unsubscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 549                 protows->client_itf->on_event_unsubscribe(protows->closure, call->request, event_name, (int)event_id);
 550 }
 551
 552 /* receives broadcasted events */
 553 static void client_on_event_broadcast(struct afb_proto_ws *protows, struct readbuf *rb)
 554 {
 555         const char *event_name;
 556         struct json_object *object;
 557
 558         if (protows->client_itf->on_event_broadcast && readbuf_string(rb, &event_name, NULL) && readbuf_object(rb, &object))
 559                 protows->client_itf->on_event_broadcast(protows->closure, event_name, object);
 560 }
 561
 562 /* pushs an event */
 563 static void client_on_event_push(struct afb_proto_ws *protows, struct readbuf *rb)
 564 {
 565         const char *event_name;
 566         uint32_t event_id;
 567         struct json_object *object;
 568
 569         if (protows->client_itf->on_event_push && client_msg_event_read(rb, &event_id, &event_name) && readbuf_object(rb, &object))
 570                 protows->client_itf->on_event_push(protows->closure, event_name, (int)event_id, object);
 571 }
 572
 573 static void client_on_reply(struct afb_proto_ws *protows, struct readbuf *rb)
 574 {
 575         struct client_call *call;
 576         struct json_object *object;
 577         const char *error, *info;
 578
 579         if (!client_msg_call_get(protows, rb, &call))
 580                 return;
 581
 582         if (readbuf_nullstring(rb, &error, NULL) && readbuf_nullstring(rb, &info, NULL) && readbuf_object(rb, &object)) {
 583                 protows->client_itf->on_reply(protows->closure, call->request, object, error, info);
 584         } else {
 585                 protows->client_itf->on_reply(protows->closure, call->request, NULL, "proto-error", "can't process success");
 586         }
 587         client_call_destroy(call);
 588 }
 589
 590 static void client_on_description(struct afb_proto_ws *protows, struct readbuf *rb)
 591 {
 592         uint32_t descid;
 593         struct client_describe *desc, **prv;
 594         struct json_object *object;
 595
 596         if (readbuf_uint32(rb, &descid)) {
 597                 pthread_mutex_lock(&protows->mutex);
 598                 prv = &protows->describes;
 599                 while ((desc = *prv) && desc->descid != descid)
 600                         prv = &desc->next;
 601                 if (!desc)
 602                         pthread_mutex_unlock(&protows->mutex);
 603                 else {
 604                         *prv = desc->next;
 605                         pthread_mutex_unlock(&protows->mutex);
 606                         if (!readbuf_object(rb, &object))
 607                                 object = NULL;
 608                         desc->callback(desc->closure, object);
 609                         free(desc);
 610                 }
 611         }
 612 }
 613
 614 /* callback when receiving binary data */
 615 static void client_on_binary_job(int sig, void *closure)
 616 {
 617         struct binary *binary = closure;
 618
 619         if (!sig) {
 620                 switch (*binary->rb.head++) {
 621                 case CHAR_FOR_REPLY: /* reply */
 622                         client_on_reply(binary->protows, &binary->rb);
 623                         break;
 624                 case CHAR_FOR_EVT_BROADCAST: /* broadcast */
 625                         client_on_event_broadcast(binary->protows, &binary->rb);
 626                         break;
 627                 case CHAR_FOR_EVT_ADD: /* creates the event */
 628                         client_on_event_create(binary->protows, &binary->rb);
 629                         break;
 630                 case CHAR_FOR_EVT_DEL: /* removes the event */
 631                         client_on_event_remove(binary->protows, &binary->rb);
 632                         break;
 633                 case CHAR_FOR_EVT_PUSH: /* pushs the event */
 634                         client_on_event_push(binary->protows, &binary->rb);
 635                         break;
 636                 case CHAR_FOR_EVT_SUBSCRIBE: /* subscribe event for a request */
 637                         client_on_event_subscribe(binary->protows, &binary->rb);
 638                         break;
 639                 case CHAR_FOR_EVT_UNSUBSCRIBE: /* unsubscribe event for a request */
 640                         client_on_event_unsubscribe(binary->protows, &binary->rb);
 641                         break;
 642                 case CHAR_FOR_DESCRIPTION: /* description */
 643                         client_on_description(binary->protows, &binary->rb);
 644                         break;
 645                 default: /* unexpected message */
 646                         /* TODO: close the connection */
 647                         break;
 648                 }
 649         }
 650         free(binary->rb.base);
 651         free(binary);
 652 }
 653
 654 /* callback when receiving binary data */
 655 static void client_on_binary(void *closure, char *data, size_t size)
 656 {
 657         struct afb_proto_ws *protows = closure;
 658
 659         queue_message_processing(protows, data, size, client_on_binary_job);
 660 }
 661
 662 int afb_proto_ws_client_call(
 663                 struct afb_proto_ws *protows,
 664                 const char *verb,
 665                 struct json_object *args,
 666                 const char *sessionid,
 667                 void *request,
 668                 const char *user_creds
 669 )
 670 {
 671         int rc = -1;
 672         struct client_call *call;
 673         struct writebuf wb = { .count = 0 };
 674
 675         /* allocate call data */
 676         call = malloc(sizeof *call);
 677         if (call == NULL) {
 678                 errno = ENOMEM;
 679                 return -1;
 680         }
 681         call->request = request;
 682
 683         /* init call data */
 684         pthread_mutex_lock(&protows->mutex);
 685         call->callid = ptr2id(call);
 686         while(client_call_search_locked(protows, call->callid) != NULL)
 687                 call->callid++;
 688         call->protows = protows;
 689         call->next = protows->calls;
 690         protows->calls = call;
 691         pthread_mutex_unlock(&protows->mutex);
 692
 693         /* creates the call message */
 694         if (!writebuf_char(&wb, CHAR_FOR_CALL)
 695          || !writebuf_uint32(&wb, call->callid)
 696          || !writebuf_string(&wb, verb)
 697          || !writebuf_string(&wb, sessionid)
 698          || !writebuf_object(&wb, args)
 699          || !writebuf_nullstring(&wb, user_creds)) {
 700                 errno = EINVAL;
 701                 goto clean;
 702         }
 703
 704         /* send */
 705         pthread_mutex_lock(&protows->mutex);
 706         rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 707         pthread_mutex_unlock(&protows->mutex);
 708         if (rc >= 0) {
 709                 rc = 0;
 710                 goto end;
 711         }
 712
 713 clean:
 714         client_call_destroy(call);
 715 end:
 716         return rc;
 717 }
 718
 719 /* get the description */
 720 int afb_proto_ws_client_describe(struct afb_proto_ws *protows, void (*callback)(void*, struct json_object*), void *closure)
 721 {
 722         struct client_describe *desc, *d;
 723         struct writebuf wb = { .count = 0 };
 724
 725         desc = malloc(sizeof *desc);
 726         if (!desc) {
 727                 errno = ENOMEM;
 728                 goto error;
 729         }
 730
 731         /* fill in stack the description of the task */
 732         pthread_mutex_lock(&protows->mutex);
 733         desc->descid = ptr2id(desc);
 734         d = protows->describes;
 735         while (d) {
 736                 if (d->descid != desc->descid)
 737                         d = d->next;
 738                 else {
 739                         desc->descid++;
 740                         d = protows->describes;
 741                 }
 742         }
 743         desc->callback = callback;
 744         desc->closure = closure;
 745         desc->protows = protows;
 746         desc->next = protows->describes;
 747         protows->describes = desc;
 748
 749         /* send */
 750         if (writebuf_char(&wb, CHAR_FOR_DESCRIBE)
 751          && writebuf_uint32(&wb, desc->descid)
 752          && afb_ws_binary_v(protows->ws, wb.iovec, wb.count) >= 0) {
 753                 pthread_mutex_unlock(&protows->mutex);
 754                 return 0;
 755         }
 756
 757         d = protows->describes;
 758         if (d == desc)
 759                 protows->describes = desc->next;
 760         else {
 761                 while(d && d->next != desc)
 762                         d = d->next;
 763                 if (d)
 764                         d->next = desc->next;
 765         }
 766         pthread_mutex_unlock(&protows->mutex);
 767         free(desc);
 768 error:
 769         /* TODO? callback(closure, NULL); */
 770         return -1;
 771 }
 772
 773 /******************* client description part for server *****************************/
 774
 775 /* on call, propagate it to the ws service */
 776 static void server_on_call(struct afb_proto_ws *protows, struct readbuf *rb)
 777 {
 778         struct afb_proto_ws_call *call;
 779         const char *uuid, *verb, *user_creds;
 780         uint32_t callid;
 781         size_t lenverb;
 782         struct json_object *object;
 783
 784         afb_proto_ws_addref(protows);
 785
 786         /* reads the call message data */
 787         if (!readbuf_uint32(rb, &callid)
 788          || !readbuf_string(rb, &verb, &lenverb)
 789          || !readbuf_string(rb, &uuid, NULL)
 790          || !readbuf_object(rb, &object)
 791          || !readbuf_nullstring(rb, &user_creds, NULL))
 792                 goto overflow;
 793
 794         /* create the request */
 795         call = malloc(sizeof *call);
 796         if (call == NULL)
 797                 goto out_of_memory;
 798
 799         call->protows = protows;
 800         call->callid = callid;
 801         call->refcount = 1;
 802         call->buffer = rb->base;
 803         rb->base = NULL; /* don't free the buffer */
 804
 805         protows->server_itf->on_call(protows->closure, call, verb, object, uuid, user_creds);
 806         return;
 807
 808 out_of_memory:
 809         json_object_put(object);
 810
 811 overflow:
 812         afb_proto_ws_unref(protows);
 813 }
 814
 815 static int server_send_description(struct afb_proto_ws *protows, uint32_t descid, struct json_object *descobj)
 816 {
 817         int rc;
 818         struct writebuf wb = { .count = 0 };
 819
 820         if (writebuf_char(&wb, CHAR_FOR_DESCRIPTION)
 821          && writebuf_uint32(&wb, descid)
 822          && writebuf_object(&wb, descobj)) {
 823                 pthread_mutex_lock(&protows->mutex);
 824                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 825                 pthread_mutex_unlock(&protows->mutex);
 826                 if (rc >= 0)
 827                         return 0;
 828         }
 829         return -1;
 830 }
 831
 832 int afb_proto_ws_describe_put(struct afb_proto_ws_describe *describe, struct json_object *description)
 833 {
 834         int rc = server_send_description(describe->protows, describe->descid, description);
 835         afb_proto_ws_unref(describe->protows);
 836         free(describe);
 837         return rc;
 838 }
 839
 840 /* on describe, propagate it to the ws service */
 841 static void server_on_describe(struct afb_proto_ws *protows, struct readbuf *rb)
 842 {
 843         uint32_t descid;
 844         struct afb_proto_ws_describe *desc;
 845
 846         /* reads the descid */
 847         if (readbuf_uint32(rb, &descid)) {
 848                 if (protows->server_itf->on_describe) {
 849                         /* create asynchronous job */
 850                         desc = malloc(sizeof *desc);
 851                         if (desc) {
 852                                 desc->descid = descid;
 853                                 desc->protows = protows;
 854                                 afb_proto_ws_addref(protows);
 855                                 protows->server_itf->on_describe(protows->closure, desc);
 856                                 return;
 857                         }
 858                 }
 859                 server_send_description(protows, descid, NULL);
 860         }
 861 }
 862
 863 /* callback when receiving binary data */
 864 static void server_on_binary_job(int sig, void *closure)
 865 {
 866         struct binary *binary = closure;
 867
 868         if (!sig) {
 869                 switch (*binary->rb.head++) {
 870                 case CHAR_FOR_CALL:
 871                         server_on_call(binary->protows, &binary->rb);
 872                         break;
 873                 case CHAR_FOR_DESCRIBE:
 874                         server_on_describe(binary->protows, &binary->rb);
 875                         break;
 876                 default: /* unexpected message */
 877                         /* TODO: close the connection */
 878                         break;
 879                 }
 880         }
 881         free(binary->rb.base);
 882         free(binary);
 883 }
 884
 885 static void server_on_binary(void *closure, char *data, size_t size)
 886 {
 887         struct afb_proto_ws *protows = closure;
 888
 889         queue_message_processing(protows, data, size, server_on_binary_job);
 890 }
 891
 892 /******************* server part: manage events **********************************/
 893
 894 static int server_event_send(struct afb_proto_ws *protows, char order, const char *event_name, int event_id, struct json_object *data)
 895 {
 896         struct writebuf wb = { .count = 0 };
 897         int rc;
 898
 899         if (writebuf_char(&wb, order)
 900          && (order == CHAR_FOR_EVT_BROADCAST || writebuf_uint32(&wb, event_id))
 901          && writebuf_string(&wb, event_name)
 902          && (order == CHAR_FOR_EVT_ADD || order == CHAR_FOR_EVT_DEL || writebuf_object(&wb, data))) {
 903                 pthread_mutex_lock(&protows->mutex);
 904                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 905                 pthread_mutex_unlock(&protows->mutex);
 906                 if (rc >= 0)
 907                         return 0;
 908         }
 909         return -1;
 910 }
 911
 912 int afb_proto_ws_server_event_create(struct afb_proto_ws *protows, const char *event_name, int event_id)
 913 {
 914         return server_event_send(protows, CHAR_FOR_EVT_ADD, event_name, event_id, NULL);
 915 }
 916
 917 int afb_proto_ws_server_event_remove(struct afb_proto_ws *protows, const char *event_name, int event_id)
 918 {
 919         return server_event_send(protows, CHAR_FOR_EVT_DEL, event_name, event_id, NULL);
 920 }
 921
 922 int afb_proto_ws_server_event_push(struct afb_proto_ws *protows, const char *event_name, int event_id, struct json_object *data)
 923 {
 924         return server_event_send(protows, CHAR_FOR_EVT_PUSH, event_name, event_id, data);
 925 }
 926
 927 int afb_proto_ws_server_event_broadcast(struct afb_proto_ws *protows, const char *event_name, struct json_object *data)
 928 {
 929         return server_event_send(protows, CHAR_FOR_EVT_BROADCAST, event_name, 0, data);
 930 }
 931
 932 /*****************************************************/
 933
 934 /* callback when receiving a hangup */
 935 static void on_hangup(void *closure)
 936 {
 937         struct afb_proto_ws *protows = closure;
 938         struct client_describe *cd, *ncd;
 939         struct client_call *call, *ncall;
 940
 941         ncd = __atomic_exchange_n(&protows->describes, NULL, __ATOMIC_RELAXED);
 942         ncall = __atomic_exchange_n(&protows->calls, NULL, __ATOMIC_RELAXED);
 943
 944         while (ncall) {
 945                 call= ncall;
 946                 ncall = call->next;
 947                 protows->client_itf->on_reply(protows->closure, call->request, NULL, "disconnected", "server hung up");
 948                 free(call);
 949         }
 950
 951         while (ncd) {
 952                 cd= ncd;
 953                 ncd = cd->next;
 954                 cd->callback(cd->closure, NULL);
 955                 free(cd);
 956         }
 957
 958         if (protows->fdev) {
 959                 fdev_unref(protows->fdev);
 960                 protows->fdev = 0;
 961                 if (protows->on_hangup)
 962                         protows->on_hangup(protows->closure);
 963         }
 964 }
 965
 966 /*****************************************************/
 967
 968 static const struct afb_ws_itf proto_ws_client_ws_itf =
 969 {
 970         .on_close = NULL,
 971         .on_text = NULL,
 972         .on_binary = client_on_binary,
 973         .on_error = NULL,
 974         .on_hangup = on_hangup
 975 };
 976
 977 static const struct afb_ws_itf server_ws_itf =
 978 {
 979         .on_close = NULL,
 980         .on_text = NULL,
 981         .on_binary = server_on_binary,
 982         .on_error = NULL,
 983         .on_hangup = on_hangup
 984 };
 985
 986 /*****************************************************/
 987
 988 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)
 989 {
 990         struct afb_proto_ws *protows;
 991
 992         protows = calloc(1, sizeof *protows);
 993         if (protows == NULL)
 994                 errno = ENOMEM;
 995         else {
 996                 fcntl(fdev_fd(fdev), F_SETFD, FD_CLOEXEC);
 997                 fcntl(fdev_fd(fdev), F_SETFL, O_NONBLOCK);
 998                 protows->ws = afb_ws_create(fdev, itf, protows);
 999                 if (protows->ws != NULL) {
1000                         protows->fdev = fdev;
1001                         protows->refcount = 1;
1002                         protows->closure = closure;
1003                         protows->server_itf = itfs;
1004                         protows->client_itf = itfc;
1005                         pthread_mutex_init(&protows->mutex, NULL);
1006                         return protows;
1007                 }
1008                 free(protows);
1009         }
1010         return NULL;
1011 }
1012
1013 struct afb_proto_ws *afb_proto_ws_create_client(struct fdev *fdev, const struct afb_proto_ws_client_itf *itf, void *closure)
1014 {
1015         return afb_proto_ws_create(fdev, NULL, itf, closure, &proto_ws_client_ws_itf);
1016 }
1017
1018 struct afb_proto_ws *afb_proto_ws_create_server(struct fdev *fdev, const struct afb_proto_ws_server_itf *itf, void *closure)
1019 {
1020         return afb_proto_ws_create(fdev, itf, NULL, closure, &server_ws_itf);
1021 }
1022
1023 void afb_proto_ws_unref(struct afb_proto_ws *protows)
1024 {
1025         if (!__atomic_sub_fetch(&protows->refcount, 1, __ATOMIC_RELAXED)) {
1026                 afb_proto_ws_hangup(protows);
1027                 afb_ws_destroy(protows->ws);
1028                 pthread_mutex_destroy(&protows->mutex);
1029                 free(protows);
1030         }
1031 }
1032
1033 void afb_proto_ws_addref(struct afb_proto_ws *protows)
1034 {
1035         __atomic_add_fetch(&protows->refcount, 1, __ATOMIC_RELAXED);
1036 }
1037
1038 int afb_proto_ws_is_client(struct afb_proto_ws *protows)
1039 {
1040         return !!protows->client_itf;
1041 }
1042
1043 int afb_proto_ws_is_server(struct afb_proto_ws *protows)
1044 {
1045         return !!protows->server_itf;
1046 }
1047
1048 void afb_proto_ws_hangup(struct afb_proto_ws *protows)
1049 {
1050         afb_ws_hangup(protows->ws);
1051 }
1052
1053 void afb_proto_ws_on_hangup(struct afb_proto_ws *protows, void (*on_hangup)(void *closure))
1054 {
1055         protows->on_hangup = on_hangup;
1056 }
1057
1058 void afb_proto_ws_set_queuing(struct afb_proto_ws *protows, int (*queuing)(void (*)(int,void*), void*))
1059 {
1060         protows->queuing = queuing;
1061 }