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 #define NO_PLUGIN_VERBOSE_MACRO
  21
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <assert.h>
  25 #include <fcntl.h>
  26 #include <unistd.h>
  27 #include <errno.h>
  28 #include <endian.h>
  29 #include <netdb.h>
  30 #include <sys/types.h>
  31 #include <sys/socket.h>
  32 #include <sys/un.h>
  33 #include <pthread.h>
  34
  35 #include <json-c/json.h>
  36
  37 #include "afb-ws.h"
  38 #include "afb-msg-json.h"
  39 #include "afb-proto-ws.h"
  40 #include "jobs.h"
  41 #include "fdev.h"
  42
  43 struct afb_proto_ws;
  44
  45 /******** implementation of internal binder protocol per api **************/
  46 /*
  47
  48 This protocol is asymetric: there is a client and a server
  49
  50 The client can require the following actions:
  51
  52   - call a verb
  53
  54   - ask for description
  55
  56 The server must reply to the previous actions by
  57
  58   - answering success or failure of the call
  59
  60   - answering the required description
  61
  62 The server can also within the context of a call
  63
  64   - subscribe or unsubscribe an event
  65
  66 For the purpose of handling events the server can:
  67
  68   - create/destroy an event
  69
  70   - push or brodcast data as an event
  71
  72 */
  73 /************** constants for protocol definition *************************/
  74
  75 #define CHAR_FOR_CALL             'C'
  76 #define CHAR_FOR_REPLY            'Y'
  77 #define CHAR_FOR_EVT_BROADCAST    '*'
  78 #define CHAR_FOR_EVT_ADD          '+'
  79 #define CHAR_FOR_EVT_DEL          '-'
  80 #define CHAR_FOR_EVT_PUSH         '!'
  81 #define CHAR_FOR_EVT_SUBSCRIBE    'S'
  82 #define CHAR_FOR_EVT_UNSUBSCRIBE  'U'
  83 #define CHAR_FOR_DESCRIBE         'D'
  84 #define CHAR_FOR_DESCRIPTION      'd'
  85
  86 /******************* handling calls *****************************/
  87
  88 /*
  89  * structure for recording calls on client side
  90  */
  91 struct client_call {
  92         struct client_call *next;       /* the next call */
  93         struct afb_proto_ws *protows;   /* the proto_ws */
  94         void *request;
  95         uint32_t callid;                /* the message identifier */
  96 };
  97
  98 /*
  99  * structure for a ws request
 100  */
 101 struct afb_proto_ws_call {
 102         struct client_call *next;       /* the next call */
 103         struct afb_proto_ws *protows;   /* the client of the request */
 104         uint32_t refcount;              /* reference count */
 105         uint32_t callid;                /* the incoming request callid */
 106         char *buffer;                   /* the incoming buffer */
 107 };
 108
 109 /*
 110  * structure for recording describe requests
 111  */
 112 struct client_describe
 113 {
 114         struct client_describe *next;
 115         struct afb_proto_ws *protows;
 116         void (*callback)(void*, struct json_object*);
 117         void *closure;
 118         uint32_t descid;
 119 };
 120
 121 /*
 122  * structure for jobs of describing
 123  */
 124 struct afb_proto_ws_describe
 125 {
 126         struct afb_proto_ws *protows;
 127         uint32_t descid;
 128 };
 129
 130 /******************* proto description for client or servers ******************/
 131
 132 struct afb_proto_ws
 133 {
 134         /* count of references */
 135         int refcount;
 136
 137         /* file descriptor */
 138         struct fdev *fdev;
 139
 140         /* resource control */
 141         pthread_mutex_t mutex;
 142
 143         /* websocket */
 144         struct afb_ws *ws;
 145
 146         /* the client closure */
 147         void *closure;
 148
 149         /* the client side interface */
 150         const struct afb_proto_ws_client_itf *client_itf;
 151
 152         /* the server side interface */
 153         const struct afb_proto_ws_server_itf *server_itf;
 154
 155         /* emitted calls (client side) */
 156         struct client_call *calls;
 157
 158         /* pending description (client side) */
 159         struct client_describe *describes;
 160
 161         /* on hangup callback */
 162         void (*on_hangup)(void *closure);
 163 };
 164
 165 /******************* streaming objects **********************************/
 166
 167 #define WRITEBUF_COUNT_MAX  32
 168 struct writebuf
 169 {
 170         struct iovec iovec[WRITEBUF_COUNT_MAX];
 171         uint32_t uints[WRITEBUF_COUNT_MAX];
 172         int count;
 173 };
 174
 175 struct readbuf
 176 {
 177         char *base, *head, *end;
 178 };
 179
 180 struct binary
 181 {
 182         struct afb_proto_ws *protows;
 183         struct readbuf rb;
 184 };
 185
 186 /******************* common useful tools **********************************/
 187
 188 /**
 189  * translate a pointer to some integer
 190  * @param ptr the pointer to translate
 191  * @return an integer
 192  */
 193 static inline uint32_t ptr2id(void *ptr)
 194 {
 195         return (uint32_t)(((intptr_t)ptr) >> 6);
 196 }
 197
 198 /******************* serialisation part **********************************/
 199
 200 static char *readbuf_get(struct readbuf *rb, uint32_t length)
 201 {
 202         char *before = rb->head;
 203         char *after = before + length;
 204         if (after > rb->end)
 205                 return 0;
 206         rb->head = after;
 207         return before;
 208 }
 209
 210 __attribute__((unused))
 211 static int readbuf_char(struct readbuf *rb, char *value)
 212 {
 213         if (rb->head >= rb->end)
 214                 return 0;
 215         *value = *rb->head++;
 216         return 1;
 217 }
 218
 219 static int readbuf_uint32(struct readbuf *rb, uint32_t *value)
 220 {
 221         char *after = rb->head + sizeof *value;
 222         if (after > rb->end)
 223                 return 0;
 224         memcpy(value, rb->head, sizeof *value);
 225         rb->head = after;
 226         *value = le32toh(*value);
 227         return 1;
 228 }
 229
 230 static int _readbuf_string_(struct readbuf *rb, const char **value, size_t *length, int nulok)
 231 {
 232         uint32_t len;
 233         if (!readbuf_uint32(rb, &len))
 234                 return 0;
 235         if (!len) {
 236                 if (!nulok)
 237                         return 0;
 238                 *value = NULL;
 239                 if (length)
 240                         *length = 0;
 241                 return 1;
 242         }
 243         if (length)
 244                 *length = (size_t)(len - 1);
 245         return (*value = readbuf_get(rb, len)) != NULL &&  rb->head[-1] == 0;
 246 }
 247
 248
 249 static int readbuf_string(struct readbuf *rb, const char **value, size_t *length)
 250 {
 251         return _readbuf_string_(rb, value, length, 0);
 252 }
 253
 254 static int readbuf_nullstring(struct readbuf *rb, const char **value, size_t *length)
 255 {
 256         return _readbuf_string_(rb, value, length, 1);
 257 }
 258
 259 static int readbuf_object(struct readbuf *rb, struct json_object **object)
 260 {
 261         const char *string;
 262         struct json_object *o;
 263         int rc = readbuf_string(rb, &string, NULL);
 264         if (rc) {
 265                 o = json_tokener_parse(string);
 266                 if (o == NULL && strcmp(string, "null"))
 267                         o = json_object_new_string(string);
 268                 *object = o;
 269         }
 270         return rc;
 271 }
 272
 273 static int writebuf_put(struct writebuf *wb, const void *value, size_t length)
 274 {
 275         int i = wb->count;
 276         if (i == WRITEBUF_COUNT_MAX)
 277                 return 0;
 278         wb->iovec[i].iov_base = (void*)value;
 279         wb->iovec[i].iov_len = length;
 280         wb->count = i + 1;
 281         return 1;
 282 }
 283
 284 static int writebuf_char(struct writebuf *wb, char value)
 285 {
 286         int i = wb->count;
 287         if (i == WRITEBUF_COUNT_MAX)
 288                 return 0;
 289         *(char*)&wb->uints[i] = value;
 290         wb->iovec[i].iov_base = &wb->uints[i];
 291         wb->iovec[i].iov_len = 1;
 292         wb->count = i + 1;
 293         return 1;
 294 }
 295
 296 static int writebuf_uint32(struct writebuf *wb, uint32_t value)
 297 {
 298         int i = wb->count;
 299         if (i == WRITEBUF_COUNT_MAX)
 300                 return 0;
 301         wb->uints[i] = htole32(value);
 302         wb->iovec[i].iov_base = &wb->uints[i];
 303         wb->iovec[i].iov_len = sizeof wb->uints[i];
 304         wb->count = i + 1;
 305         return 1;
 306 }
 307
 308 static int writebuf_string_length(struct writebuf *wb, const char *value, size_t length)
 309 {
 310         uint32_t len = (uint32_t)++length;
 311         return (size_t)len == length && len && writebuf_uint32(wb, len) && writebuf_put(wb, value, length);
 312 }
 313
 314 static int writebuf_string(struct writebuf *wb, const char *value)
 315 {
 316         return writebuf_string_length(wb, value, strlen(value));
 317 }
 318
 319 static int writebuf_nullstring(struct writebuf *wb, const char *value)
 320 {
 321         return value ? writebuf_string_length(wb, value, strlen(value)) : writebuf_uint32(wb, 0);
 322 }
 323
 324 static int writebuf_object(struct writebuf *wb, struct json_object *object)
 325 {
 326         const char *string = json_object_to_json_string_ext(object, JSON_C_TO_STRING_PLAIN);
 327         return string != NULL && writebuf_string(wb, string);
 328 }
 329
 330 /******************* ws request part for server *****************/
 331
 332 void afb_proto_ws_call_addref(struct afb_proto_ws_call *call)
 333 {
 334         __atomic_add_fetch(&call->refcount, 1, __ATOMIC_RELAXED);
 335 }
 336
 337 void afb_proto_ws_call_unref(struct afb_proto_ws_call *call)
 338 {
 339         if (__atomic_sub_fetch(&call->refcount, 1, __ATOMIC_RELAXED))
 340                 return;
 341
 342         afb_proto_ws_unref(call->protows);
 343         free(call->buffer);
 344         free(call);
 345 }
 346
 347 int afb_proto_ws_call_reply(struct afb_proto_ws_call *call, struct json_object *obj, const char *error, const char *info)
 348 {
 349         int rc = -1;
 350         struct writebuf wb = { .count = 0 };
 351         struct afb_proto_ws *protows = call->protows;
 352
 353         if (writebuf_char(&wb, CHAR_FOR_REPLY)
 354          && writebuf_uint32(&wb, call->callid)
 355          && writebuf_nullstring(&wb, error)
 356          && writebuf_nullstring(&wb, info)
 357          && writebuf_object(&wb, obj)) {
 358                 pthread_mutex_lock(&protows->mutex);
 359                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 360                 pthread_mutex_unlock(&protows->mutex);
 361                 if (rc >= 0) {
 362                         rc = 0;
 363                         goto success;
 364                 }
 365         }
 366 success:
 367         return rc;
 368 }
 369
 370 int afb_proto_ws_call_subscribe(struct afb_proto_ws_call *call, const char *event_name, int event_id)
 371 {
 372         int rc = -1;
 373         struct writebuf wb = { .count = 0 };
 374         struct afb_proto_ws *protows = call->protows;
 375
 376         if (writebuf_char(&wb, CHAR_FOR_EVT_SUBSCRIBE)
 377          && writebuf_uint32(&wb, call->callid)
 378          && writebuf_uint32(&wb, (uint32_t)event_id)
 379          && writebuf_string(&wb, event_name)) {
 380                 pthread_mutex_lock(&protows->mutex);
 381                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 382                 pthread_mutex_unlock(&protows->mutex);
 383                 if (rc >= 0) {
 384                         rc = 0;
 385                         goto success;
 386                 }
 387         }
 388 success:
 389         return rc;
 390 }
 391
 392 int afb_proto_ws_call_unsubscribe(struct afb_proto_ws_call *call, const char *event_name, int event_id)
 393 {
 394         int rc = -1;
 395         struct writebuf wb = { .count = 0 };
 396         struct afb_proto_ws *protows = call->protows;
 397
 398         if (writebuf_char(&wb, CHAR_FOR_EVT_UNSUBSCRIBE)
 399          && writebuf_uint32(&wb, call->callid)
 400          && writebuf_uint32(&wb, (uint32_t)event_id)
 401          && writebuf_string(&wb, event_name)) {
 402                 pthread_mutex_lock(&protows->mutex);
 403                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 404                 pthread_mutex_unlock(&protows->mutex);
 405                 if (rc >= 0) {
 406                         rc = 0;
 407                         goto success;
 408                 }
 409         }
 410 success:
 411         return rc;
 412 }
 413
 414 /******************* client part **********************************/
 415
 416 /* search a memorized call */
 417 static struct client_call *client_call_search_locked(struct afb_proto_ws *protows, uint32_t callid)
 418 {
 419         struct client_call *call;
 420
 421         call = protows->calls;
 422         while (call != NULL && call->callid != callid)
 423                 call = call->next;
 424
 425         return call;
 426 }
 427
 428 static struct client_call *client_call_search_unlocked(struct afb_proto_ws *protows, uint32_t callid)
 429 {
 430         struct client_call *result;
 431
 432         pthread_mutex_lock(&protows->mutex);
 433         result = client_call_search_locked(protows, callid);
 434         pthread_mutex_unlock(&protows->mutex);
 435         return result;
 436 }
 437
 438 /* free and release the memorizing call */
 439 static void client_call_destroy(struct client_call *call)
 440 {
 441         struct client_call **prv;
 442         struct afb_proto_ws *protows = call->protows;
 443
 444         pthread_mutex_lock(&protows->mutex);
 445         prv = &call->protows->calls;
 446         while (*prv != NULL) {
 447                 if (*prv == call) {
 448                         *prv = call->next;
 449                         break;
 450                 }
 451                 prv = &(*prv)->next;
 452         }
 453         pthread_mutex_unlock(&protows->mutex);
 454         free(call);
 455 }
 456
 457 /* get event data from the message */
 458 static int client_msg_event_read(struct readbuf *rb, uint32_t *eventid, const char **name)
 459 {
 460         return readbuf_uint32(rb, eventid) && readbuf_string(rb, name, NULL);
 461 }
 462
 463 /* get event from the message */
 464 static int client_msg_call_get(struct afb_proto_ws *protows, struct readbuf *rb, struct client_call **call)
 465 {
 466         uint32_t callid;
 467
 468         /* get event data from the message */
 469         if (!readbuf_uint32(rb, &callid)) {
 470                 return 0;
 471         }
 472
 473         /* get the call */
 474         *call = client_call_search_unlocked(protows, callid);
 475         if (*call == NULL) {
 476                 return 0;
 477         }
 478
 479         return 1;
 480 }
 481
 482 /* adds an event */
 483 static void client_on_event_create(struct afb_proto_ws *protows, struct readbuf *rb)
 484 {
 485         const char *event_name;
 486         uint32_t event_id;
 487
 488         if (protows->client_itf->on_event_create && client_msg_event_read(rb, &event_id, &event_name))
 489                 protows->client_itf->on_event_create(protows->closure, event_name, (int)event_id);
 490 }
 491
 492 /* removes an event */
 493 static void client_on_event_remove(struct afb_proto_ws *protows, struct readbuf *rb)
 494 {
 495         const char *event_name;
 496         uint32_t event_id;
 497
 498         if (protows->client_itf->on_event_remove && client_msg_event_read(rb, &event_id, &event_name))
 499                 protows->client_itf->on_event_remove(protows->closure, event_name, (int)event_id);
 500 }
 501
 502 /* subscribes an event */
 503 static void client_on_event_subscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 504 {
 505         const char *event_name;
 506         uint32_t event_id;
 507         struct client_call *call;
 508
 509         if (protows->client_itf->on_event_subscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 510                 protows->client_itf->on_event_subscribe(protows->closure, call->request, event_name, (int)event_id);
 511 }
 512
 513 /* unsubscribes an event */
 514 static void client_on_event_unsubscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 515 {
 516         const char *event_name;
 517         uint32_t event_id;
 518         struct client_call *call;
 519
 520         if (protows->client_itf->on_event_unsubscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 521                 protows->client_itf->on_event_unsubscribe(protows->closure, call->request, event_name, (int)event_id);
 522 }
 523
 524 /* receives broadcasted events */
 525 static void client_on_event_broadcast(struct afb_proto_ws *protows, struct readbuf *rb)
 526 {
 527         const char *event_name;
 528         struct json_object *object;
 529
 530         if (protows->client_itf->on_event_broadcast && readbuf_string(rb, &event_name, NULL) && readbuf_object(rb, &object))
 531                 protows->client_itf->on_event_broadcast(protows->closure, event_name, object);
 532 }
 533
 534 /* pushs an event */
 535 static void client_on_event_push(struct afb_proto_ws *protows, struct readbuf *rb)
 536 {
 537         const char *event_name;
 538         uint32_t event_id;
 539         struct json_object *object;
 540
 541         if (protows->client_itf->on_event_push && client_msg_event_read(rb, &event_id, &event_name) && readbuf_object(rb, &object))
 542                 protows->client_itf->on_event_push(protows->closure, event_name, (int)event_id, object);
 543 }
 544
 545 static void client_on_reply(struct afb_proto_ws *protows, struct readbuf *rb)
 546 {
 547         struct client_call *call;
 548         struct json_object *object;
 549         const char *error, *info;
 550
 551         if (!client_msg_call_get(protows, rb, &call))
 552                 return;
 553
 554         if (readbuf_nullstring(rb, &error, NULL) && readbuf_nullstring(rb, &info, NULL) && readbuf_object(rb, &object)) {
 555                 protows->client_itf->on_reply(protows->closure, call->request, object, error, info);
 556         } else {
 557                 protows->client_itf->on_reply(protows->closure, call->request, NULL, "proto-error", "can't process success");
 558         }
 559         client_call_destroy(call);
 560 }
 561
 562 static void client_on_description(struct afb_proto_ws *protows, struct readbuf *rb)
 563 {
 564         uint32_t descid;
 565         struct client_describe *desc, **prv;
 566         struct json_object *object;
 567
 568         if (readbuf_uint32(rb, &descid)) {
 569                 pthread_mutex_lock(&protows->mutex);
 570                 prv = &protows->describes;
 571                 while ((desc = *prv) && desc->descid != descid)
 572                         prv = &desc->next;
 573                 if (!desc)
 574                         pthread_mutex_unlock(&protows->mutex);
 575                 else {
 576                         *prv = desc->next;
 577                         pthread_mutex_unlock(&protows->mutex);
 578                         if (!readbuf_object(rb, &object))
 579                                 object = NULL;
 580                         desc->callback(desc->closure, object);
 581                         free(desc);
 582                 }
 583         }
 584 }
 585
 586 /* callback when receiving binary data */
 587 static void client_on_binary_job(int sig, void *closure)
 588 {
 589         struct binary *binary = closure;
 590
 591         if (!sig) {
 592                 switch (*binary->rb.head++) {
 593                 case CHAR_FOR_REPLY: /* reply */
 594                         client_on_reply(binary->protows, &binary->rb);
 595                         break;
 596                 case CHAR_FOR_EVT_BROADCAST: /* broadcast */
 597                         client_on_event_broadcast(binary->protows, &binary->rb);
 598                         break;
 599                 case CHAR_FOR_EVT_ADD: /* creates the event */
 600                         client_on_event_create(binary->protows, &binary->rb);
 601                         break;
 602                 case CHAR_FOR_EVT_DEL: /* removes the event */
 603                         client_on_event_remove(binary->protows, &binary->rb);
 604                         break;
 605                 case CHAR_FOR_EVT_PUSH: /* pushs the event */
 606                         client_on_event_push(binary->protows, &binary->rb);
 607                         break;
 608                 case CHAR_FOR_EVT_SUBSCRIBE: /* subscribe event for a request */
 609                         client_on_event_subscribe(binary->protows, &binary->rb);
 610                         break;
 611                 case CHAR_FOR_EVT_UNSUBSCRIBE: /* unsubscribe event for a request */
 612                         client_on_event_unsubscribe(binary->protows, &binary->rb);
 613                         break;
 614                 case CHAR_FOR_DESCRIPTION: /* description */
 615                         client_on_description(binary->protows, &binary->rb);
 616                         break;
 617                 default: /* unexpected message */
 618                         /* TODO: close the connection */
 619                         break;
 620                 }
 621         }
 622         free(binary->rb.base);
 623         free(binary);
 624 }
 625
 626 /* callback when receiving binary data */
 627 static void client_on_binary(void *closure, char *data, size_t size)
 628 {
 629         int rc;
 630         struct binary *binary;
 631
 632         if (size) {
 633                 binary = malloc(sizeof *binary);
 634                 if (!binary) {
 635                         errno = ENOMEM;
 636                 } else {
 637                         binary->protows = closure;
 638                         binary->rb.base = data;
 639                         binary->rb.head = data;
 640                         binary->rb.end = data + size;
 641                         rc = jobs_queue(NULL, 0, client_on_binary_job, binary);
 642                         if (rc >= 0)
 643                                 return;
 644                         free(binary);
 645                 }
 646         }
 647         free(data);
 648 }
 649
 650 int afb_proto_ws_client_call(
 651                 struct afb_proto_ws *protows,
 652                 const char *verb,
 653                 struct json_object *args,
 654                 const char *sessionid,
 655                 void *request,
 656                 const char *user_creds
 657 )
 658 {
 659         int rc = -1;
 660         struct client_call *call;
 661         struct writebuf wb = { .count = 0 };
 662
 663         /* allocate call data */
 664         call = malloc(sizeof *call);
 665         if (call == NULL) {
 666                 errno = ENOMEM;
 667                 return -1;
 668         }
 669         call->request = request;
 670
 671         /* init call data */
 672         pthread_mutex_lock(&protows->mutex);
 673         call->callid = ptr2id(call);
 674         while(client_call_search_locked(protows, call->callid) != NULL)
 675                 call->callid++;
 676         call->protows = protows;
 677         call->next = protows->calls;
 678         protows->calls = call;
 679         pthread_mutex_unlock(&protows->mutex);
 680
 681         /* creates the call message */
 682         if (!writebuf_char(&wb, CHAR_FOR_CALL)
 683          || !writebuf_uint32(&wb, call->callid)
 684          || !writebuf_string(&wb, verb)
 685          || !writebuf_string(&wb, sessionid)
 686          || !writebuf_object(&wb, args)
 687          || !writebuf_nullstring(&wb, user_creds)) {
 688                 errno = EINVAL;
 689                 goto clean;
 690         }
 691
 692         /* send */
 693         pthread_mutex_lock(&protows->mutex);
 694         rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 695         pthread_mutex_unlock(&protows->mutex);
 696         if (rc >= 0) {
 697                 rc = 0;
 698                 goto end;
 699         }
 700
 701 clean:
 702         client_call_destroy(call);
 703 end:
 704         return rc;
 705 }
 706
 707 /* get the description */
 708 int afb_proto_ws_client_describe(struct afb_proto_ws *protows, void (*callback)(void*, struct json_object*), void *closure)
 709 {
 710         struct client_describe *desc, *d;
 711         struct writebuf wb = { .count = 0 };
 712
 713         desc = malloc(sizeof *desc);
 714         if (!desc) {
 715                 errno = ENOMEM;
 716                 goto error;
 717         }
 718
 719         /* fill in stack the description of the task */
 720         pthread_mutex_lock(&protows->mutex);
 721         desc->descid = ptr2id(desc);
 722         d = protows->describes;
 723         while (d) {
 724                 if (d->descid != desc->descid)
 725                         d = d->next;
 726                 else {
 727                         desc->descid++;
 728                         d = protows->describes;
 729                 }
 730         }
 731         desc->callback = callback;
 732         desc->closure = closure;
 733         desc->protows = protows;
 734         desc->next = protows->describes;
 735         protows->describes = desc;
 736
 737         /* send */
 738         if (writebuf_char(&wb, CHAR_FOR_DESCRIBE)
 739          && writebuf_uint32(&wb, desc->descid)
 740          && afb_ws_binary_v(protows->ws, wb.iovec, wb.count) >= 0) {
 741                 pthread_mutex_unlock(&protows->mutex);
 742                 return 0;
 743         }
 744
 745         d = protows->describes;
 746         if (d == desc)
 747                 protows->describes = desc->next;
 748         else {
 749                 while(d && d->next != desc)
 750                         d = d->next;
 751                 if (d)
 752                         d->next = desc->next;
 753         }
 754         pthread_mutex_unlock(&protows->mutex);
 755         free(desc);
 756 error:
 757         /* TODO? callback(closure, NULL); */
 758         return -1;
 759 }
 760
 761 /******************* client description part for server *****************************/
 762
 763 /* on call, propagate it to the ws service */
 764 static void server_on_call(struct afb_proto_ws *protows, struct readbuf *rb)
 765 {
 766         struct afb_proto_ws_call *call;
 767         const char *uuid, *verb, *user_creds;
 768         uint32_t callid;
 769         size_t lenverb;
 770         struct json_object *object;
 771
 772         afb_proto_ws_addref(protows);
 773
 774         /* reads the call message data */
 775         if (!readbuf_uint32(rb, &callid)
 776          || !readbuf_string(rb, &verb, &lenverb)
 777          || !readbuf_string(rb, &uuid, NULL)
 778          || !readbuf_object(rb, &object)
 779          || !readbuf_nullstring(rb, &user_creds, NULL))
 780                 goto overflow;
 781
 782         /* create the request */
 783         call = malloc(sizeof *call);
 784         if (call == NULL)
 785                 goto out_of_memory;
 786
 787         call->protows = protows;
 788         call->callid = callid;
 789         call->refcount = 1;
 790         call->buffer = rb->base;
 791         rb->base = NULL; /* don't free the buffer */
 792
 793         protows->server_itf->on_call(protows->closure, call, verb, object, uuid, user_creds);
 794         return;
 795
 796 out_of_memory:
 797         json_object_put(object);
 798
 799 overflow:
 800         afb_proto_ws_unref(protows);
 801 }
 802
 803 static int server_send_description(struct afb_proto_ws *protows, uint32_t descid, struct json_object *descobj)
 804 {
 805         int rc;
 806         struct writebuf wb = { .count = 0 };
 807
 808         if (writebuf_char(&wb, CHAR_FOR_DESCRIPTION)
 809          && writebuf_uint32(&wb, descid)
 810          && writebuf_object(&wb, descobj)) {
 811                 pthread_mutex_lock(&protows->mutex);
 812                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 813                 pthread_mutex_unlock(&protows->mutex);
 814                 if (rc >= 0)
 815                         return 0;
 816         }
 817         return -1;
 818 }
 819
 820 int afb_proto_ws_describe_put(struct afb_proto_ws_describe *describe, struct json_object *description)
 821 {
 822         int rc = server_send_description(describe->protows, describe->descid, description);
 823         afb_proto_ws_unref(describe->protows);
 824         free(describe);
 825         return rc;
 826 }
 827
 828 /* on describe, propagate it to the ws service */
 829 static void server_on_describe(struct afb_proto_ws *protows, struct readbuf *rb)
 830 {
 831         uint32_t descid;
 832         struct afb_proto_ws_describe *desc;
 833
 834         /* reads the descid */
 835         if (readbuf_uint32(rb, &descid)) {
 836                 if (protows->server_itf->on_describe) {
 837                         /* create asynchronous job */
 838                         desc = malloc(sizeof *desc);
 839                         if (desc) {
 840                                 desc->descid = descid;
 841                                 desc->protows = protows;
 842                                 afb_proto_ws_addref(protows);
 843                                 protows->server_itf->on_describe(protows->closure, desc);
 844                                 return;
 845                         }
 846                 }
 847                 server_send_description(protows, descid, NULL);
 848         }
 849 }
 850
 851 /* callback when receiving binary data */
 852 static void server_on_binary_job(int sig, void *closure)
 853 {
 854         struct binary *binary = closure;
 855
 856         if (!sig) {
 857                 switch (*binary->rb.head++) {
 858                 case CHAR_FOR_CALL:
 859                         server_on_call(binary->protows, &binary->rb);
 860                         break;
 861                 case CHAR_FOR_DESCRIBE:
 862                         server_on_describe(binary->protows, &binary->rb);
 863                         break;
 864                 default: /* unexpected message */
 865                         /* TODO: close the connection */
 866                         break;
 867                 }
 868         }
 869         free(binary->rb.base);
 870         free(binary);
 871 }
 872
 873 static void server_on_binary(void *closure, char *data, size_t size)
 874 {
 875         int rc;
 876         struct binary *binary;
 877
 878         if (size) {
 879                 binary = malloc(sizeof *binary);
 880                 if (!binary) {
 881                         errno = ENOMEM;
 882                 } else {
 883                         binary->protows = closure;
 884                         binary->rb.base = data;
 885                         binary->rb.head = data;
 886                         binary->rb.end = data + size;
 887                         rc = jobs_queue(NULL, 0, server_on_binary_job, binary);
 888                         if (rc >= 0)
 889                                 return;
 890                         free(binary);
 891                 }
 892         }
 893         free(data);
 894 }
 895
 896 /******************* server part: manage events **********************************/
 897
 898 static int server_event_send(struct afb_proto_ws *protows, char order, const char *event_name, int event_id, struct json_object *data)
 899 {
 900         struct writebuf wb = { .count = 0 };
 901         int rc;
 902
 903         if (writebuf_char(&wb, order)
 904          && (order == CHAR_FOR_EVT_BROADCAST || writebuf_uint32(&wb, event_id))
 905          && writebuf_string(&wb, event_name)
 906          && (order == CHAR_FOR_EVT_ADD || order == CHAR_FOR_EVT_DEL || writebuf_object(&wb, data))) {
 907                 pthread_mutex_lock(&protows->mutex);
 908                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 909                 pthread_mutex_unlock(&protows->mutex);
 910                 if (rc >= 0)
 911                         return 0;
 912         }
 913         return -1;
 914 }
 915
 916 int afb_proto_ws_server_event_create(struct afb_proto_ws *protows, const char *event_name, int event_id)
 917 {
 918         return server_event_send(protows, CHAR_FOR_EVT_ADD, event_name, event_id, NULL);
 919 }
 920
 921 int afb_proto_ws_server_event_remove(struct afb_proto_ws *protows, const char *event_name, int event_id)
 922 {
 923         return server_event_send(protows, CHAR_FOR_EVT_DEL, event_name, event_id, NULL);
 924 }
 925
 926 int afb_proto_ws_server_event_push(struct afb_proto_ws *protows, const char *event_name, int event_id, struct json_object *data)
 927 {
 928         return server_event_send(protows, CHAR_FOR_EVT_PUSH, event_name, event_id, data);
 929 }
 930
 931 int afb_proto_ws_server_event_broadcast(struct afb_proto_ws *protows, const char *event_name, struct json_object *data)
 932 {
 933         return server_event_send(protows, CHAR_FOR_EVT_BROADCAST, event_name, 0, data);
 934 }
 935
 936 /*****************************************************/
 937
 938 /* callback when receiving a hangup */
 939 static void on_hangup(void *closure)
 940 {
 941         struct afb_proto_ws *protows = closure;
 942         struct client_describe *cd, *ncd;
 943
 944         ncd = protows->describes;
 945         while (ncd) {
 946                 cd= ncd;
 947                 ncd = cd->next;
 948                 cd->callback(cd->closure, NULL);
 949                 free(cd);
 950         }
 951
 952         if (protows->fdev) {
 953                 fdev_unref(protows->fdev);
 954                 protows->fdev = 0;
 955                 if (protows->on_hangup)
 956                         protows->on_hangup(protows->closure);
 957         }
 958 }
 959
 960 /*****************************************************/
 961
 962 static const struct afb_ws_itf proto_ws_client_ws_itf =
 963 {
 964         .on_close = NULL,
 965         .on_text = NULL,
 966         .on_binary = client_on_binary,
 967         .on_error = NULL,
 968         .on_hangup = on_hangup
 969 };
 970
 971 static const struct afb_ws_itf server_ws_itf =
 972 {
 973         .on_close = NULL,
 974         .on_text = NULL,
 975         .on_binary = server_on_binary,
 976         .on_error = NULL,
 977         .on_hangup = on_hangup
 978 };
 979
 980 /*****************************************************/
 981
 982 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)
 983 {
 984         struct afb_proto_ws *protows;
 985
 986         protows = calloc(1, sizeof *protows);
 987         if (protows == NULL)
 988                 errno = ENOMEM;
 989         else {
 990                 fcntl(fdev_fd(fdev), F_SETFD, FD_CLOEXEC);
 991                 fcntl(fdev_fd(fdev), F_SETFL, O_NONBLOCK);
 992                 protows->ws = afb_ws_create(fdev, itf, protows);
 993                 if (protows->ws != NULL) {
 994                         protows->fdev = fdev;
 995                         protows->refcount = 1;
 996                         protows->closure = closure;
 997                         protows->server_itf = itfs;
 998                         protows->client_itf = itfc;
 999                         pthread_mutex_init(&protows->mutex, NULL);
1000                         return protows;
1001                 }
1002                 free(protows);
1003         }
1004         return NULL;
1005 }
1006
1007 struct afb_proto_ws *afb_proto_ws_create_client(struct fdev *fdev, const struct afb_proto_ws_client_itf *itf, void *closure)
1008 {
1009         return afb_proto_ws_create(fdev, NULL, itf, closure, &proto_ws_client_ws_itf);
1010 }
1011
1012 struct afb_proto_ws *afb_proto_ws_create_server(struct fdev *fdev, const struct afb_proto_ws_server_itf *itf, void *closure)
1013 {
1014         return afb_proto_ws_create(fdev, itf, NULL, closure, &server_ws_itf);
1015 }
1016
1017 void afb_proto_ws_unref(struct afb_proto_ws *protows)
1018 {
1019         if (!__atomic_sub_fetch(&protows->refcount, 1, __ATOMIC_RELAXED)) {
1020                 afb_proto_ws_hangup(protows);
1021                 afb_ws_destroy(protows->ws);
1022                 pthread_mutex_destroy(&protows->mutex);
1023                 free(protows);
1024         }
1025 }
1026
1027 void afb_proto_ws_addref(struct afb_proto_ws *protows)
1028 {
1029         __atomic_add_fetch(&protows->refcount, 1, __ATOMIC_RELAXED);
1030 }
1031
1032 int afb_proto_ws_is_client(struct afb_proto_ws *protows)
1033 {
1034         return !!protows->client_itf;
1035 }
1036
1037 int afb_proto_ws_is_server(struct afb_proto_ws *protows)
1038 {
1039         return !!protows->server_itf;
1040 }
1041
1042 void afb_proto_ws_hangup(struct afb_proto_ws *protows)
1043 {
1044         afb_ws_hangup(protows->ws);
1045 }
1046
1047 void afb_proto_ws_on_hangup(struct afb_proto_ws *protows, void (*on_hangup)(void *closure))
1048 {
1049         protows->on_hangup = on_hangup;
1050 }
1051