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 #include "verbose.h"
  41
  42 struct afb_proto_ws;
  43
  44 /******** implementation of internal binder protocol per api **************/
  45 /*
  46
  47 This protocol is asymetric: there is a client and a server
  48
  49 The client can require the following actions:
  50
  51   - call a verb
  52
  53   - ask for description
  54
  55 The server must reply to the previous actions by
  56
  57   - answering success or failure of the call
  58
  59   - answering the required description
  60
  61 The server can also within the context of a call
  62
  63   - subscribe or unsubscribe an event
  64
  65 For the purpose of handling events the server can:
  66
  67   - create/destroy an event
  68
  69   - push or brodcast data as an event
  70
  71 */
  72 /************** constants for protocol definition *************************/
  73
  74 #define CHAR_FOR_CALL             'C'
  75 #define CHAR_FOR_REPLY            'Y'
  76 #define CHAR_FOR_EVT_BROADCAST    '*'
  77 #define CHAR_FOR_EVT_ADD          '+'
  78 #define CHAR_FOR_EVT_DEL          '-'
  79 #define CHAR_FOR_EVT_PUSH         '!'
  80 #define CHAR_FOR_EVT_SUBSCRIBE    'S'
  81 #define CHAR_FOR_EVT_UNSUBSCRIBE  'U'
  82 #define CHAR_FOR_DESCRIBE         'D'
  83 #define CHAR_FOR_DESCRIPTION      'd'
  84
  85 /******************* handling calls *****************************/
  86
  87 /*
  88  * structure for recording calls on client side
  89  */
  90 struct client_call {
  91         struct client_call *next;       /* the next call */
  92         struct afb_proto_ws *protows;   /* the proto_ws */
  93         void *request;                  /* the request closure */
  94         uint32_t callid;                /* the message identifier */
  95 };
  96
  97 /*
  98  * structure for a ws request
  99  */
 100 struct afb_proto_ws_call {
 101         struct client_call *next;       /* the next call */
 102         struct afb_proto_ws *protows;   /* the client of the request */
 103         uint32_t refcount;              /* reference count */
 104         uint32_t callid;                /* the incoming request callid */
 105         char *buffer;                   /* the incoming buffer */
 106 };
 107
 108 /*
 109  * structure for recording describe requests
 110  */
 111 struct client_describe
 112 {
 113         struct client_describe *next;
 114         struct afb_proto_ws *protows;
 115         void (*callback)(void*, struct json_object*);
 116         void *closure;
 117         uint32_t descid;
 118 };
 119
 120 /*
 121  * structure for jobs of describing
 122  */
 123 struct afb_proto_ws_describe
 124 {
 125         struct afb_proto_ws *protows;
 126         uint32_t descid;
 127 };
 128
 129 /******************* proto description for client or servers ******************/
 130
 131 struct afb_proto_ws
 132 {
 133         /* count of references */
 134         int refcount;
 135
 136         /* file descriptor */
 137         struct fdev *fdev;
 138
 139         /* resource control */
 140         pthread_mutex_t mutex;
 141
 142         /* websocket */
 143         struct afb_ws *ws;
 144
 145         /* the client closure */
 146         void *closure;
 147
 148         /* the client side interface */
 149         const struct afb_proto_ws_client_itf *client_itf;
 150
 151         /* the server side interface */
 152         const struct afb_proto_ws_server_itf *server_itf;
 153
 154         /* emitted calls (client side) */
 155         struct client_call *calls;
 156
 157         /* pending description (client side) */
 158         struct client_describe *describes;
 159
 160         /* on hangup callback */
 161         void (*on_hangup)(void *closure);
 162
 163         /* queuing facility for processing messages */
 164         int (*queuing)(void (*process)(int s, void *c), void *closure);
 165 };
 166
 167 /******************* streaming objects **********************************/
 168
 169 #define WRITEBUF_COUNT_MAX  32
 170 struct writebuf
 171 {
 172         struct iovec iovec[WRITEBUF_COUNT_MAX];
 173         uint32_t uints[WRITEBUF_COUNT_MAX];
 174         int count;
 175 };
 176
 177 struct readbuf
 178 {
 179         char *base, *head, *end;
 180 };
 181
 182 struct binary
 183 {
 184         struct afb_proto_ws *protows;
 185         struct readbuf rb;
 186 };
 187
 188 /******************* common useful tools **********************************/
 189
 190 /**
 191  * translate a pointer to some integer
 192  * @param ptr the pointer to translate
 193  * @return an integer
 194  */
 195 static inline uint32_t ptr2id(void *ptr)
 196 {
 197         return (uint32_t)(((intptr_t)ptr) >> 6);
 198 }
 199
 200 /******************* serialisation part **********************************/
 201
 202 static char *readbuf_get(struct readbuf *rb, uint32_t length)
 203 {
 204         char *before = rb->head;
 205         char *after = before + length;
 206         if (after > rb->end)
 207                 return 0;
 208         rb->head = after;
 209         return before;
 210 }
 211
 212 __attribute__((unused))
 213 static int readbuf_char(struct readbuf *rb, char *value)
 214 {
 215         if (rb->head >= rb->end)
 216                 return 0;
 217         *value = *rb->head++;
 218         return 1;
 219 }
 220
 221 static int readbuf_uint32(struct readbuf *rb, uint32_t *value)
 222 {
 223         char *after = rb->head + sizeof *value;
 224         if (after > rb->end)
 225                 return 0;
 226         memcpy(value, rb->head, sizeof *value);
 227         rb->head = after;
 228         *value = le32toh(*value);
 229         return 1;
 230 }
 231
 232 static int _readbuf_string_(struct readbuf *rb, const char **value, size_t *length, int nulok)
 233 {
 234         uint32_t len;
 235         if (!readbuf_uint32(rb, &len))
 236                 return 0;
 237         if (!len) {
 238                 if (!nulok)
 239                         return 0;
 240                 *value = NULL;
 241                 if (length)
 242                         *length = 0;
 243                 return 1;
 244         }
 245         if (length)
 246                 *length = (size_t)(len - 1);
 247         return (*value = readbuf_get(rb, len)) != NULL &&  rb->head[-1] == 0;
 248 }
 249
 250
 251 static int readbuf_string(struct readbuf *rb, const char **value, size_t *length)
 252 {
 253         return _readbuf_string_(rb, value, length, 0);
 254 }
 255
 256 static int readbuf_nullstring(struct readbuf *rb, const char **value, size_t *length)
 257 {
 258         return _readbuf_string_(rb, value, length, 1);
 259 }
 260
 261 static int readbuf_object(struct readbuf *rb, struct json_object **object)
 262 {
 263         const char *string;
 264         struct json_object *o;
 265         enum json_tokener_error jerr;
 266         int rc = readbuf_string(rb, &string, NULL);
 267         if (rc) {
 268                 o = json_tokener_parse_verbose(string, &jerr);
 269                 if (jerr != json_tokener_success)
 270                         o = json_object_new_string(string);
 271                 *object = o;
 272         }
 273         return rc;
 274 }
 275
 276 static int writebuf_put(struct writebuf *wb, const void *value, size_t length)
 277 {
 278         int i = wb->count;
 279         if (i == WRITEBUF_COUNT_MAX)
 280                 return 0;
 281         wb->iovec[i].iov_base = (void*)value;
 282         wb->iovec[i].iov_len = length;
 283         wb->count = i + 1;
 284         return 1;
 285 }
 286
 287 static int writebuf_char(struct writebuf *wb, char value)
 288 {
 289         int i = wb->count;
 290         if (i == WRITEBUF_COUNT_MAX)
 291                 return 0;
 292         *(char*)&wb->uints[i] = value;
 293         wb->iovec[i].iov_base = &wb->uints[i];
 294         wb->iovec[i].iov_len = 1;
 295         wb->count = i + 1;
 296         return 1;
 297 }
 298
 299 static int writebuf_uint32(struct writebuf *wb, uint32_t value)
 300 {
 301         int i = wb->count;
 302         if (i == WRITEBUF_COUNT_MAX)
 303                 return 0;
 304         wb->uints[i] = htole32(value);
 305         wb->iovec[i].iov_base = &wb->uints[i];
 306         wb->iovec[i].iov_len = sizeof wb->uints[i];
 307         wb->count = i + 1;
 308         return 1;
 309 }
 310
 311 static int writebuf_string_length(struct writebuf *wb, const char *value, size_t length)
 312 {
 313         uint32_t len = (uint32_t)++length;
 314         return (size_t)len == length && len && writebuf_uint32(wb, len) && writebuf_put(wb, value, length);
 315 }
 316
 317 static int writebuf_string(struct writebuf *wb, const char *value)
 318 {
 319         return writebuf_string_length(wb, value, strlen(value));
 320 }
 321
 322 static int writebuf_nullstring(struct writebuf *wb, const char *value)
 323 {
 324         return value ? writebuf_string_length(wb, value, strlen(value)) : writebuf_uint32(wb, 0);
 325 }
 326
 327 static int writebuf_object(struct writebuf *wb, struct json_object *object)
 328 {
 329         const char *string = json_object_to_json_string_ext(object, JSON_C_TO_STRING_PLAIN);
 330         return string != NULL && writebuf_string(wb, string);
 331 }
 332
 333 /******************* queuing of messages *****************/
 334
 335 /* queue the processing of the received message (except if size=0 cause it's not a valid message) */
 336 static void queue_message_processing(struct afb_proto_ws *protows, char *data, size_t size, void (*processing)(int,void*))
 337 {
 338         struct binary *binary;
 339
 340         if (size) {
 341                 binary = malloc(sizeof *binary);
 342                 if (!binary) {
 343                         /* TODO process the problem */
 344                         errno = ENOMEM;
 345                 } else {
 346                         binary->protows = protows;
 347                         binary->rb.base = data;
 348                         binary->rb.head = data;
 349                         binary->rb.end = data + size;
 350                         if (!protows->queuing
 351                          || protows->queuing(processing, binary) < 0)
 352                                 processing(0, binary);
 353                         return;
 354                 }
 355         }
 356         free(data);
 357 }
 358
 359 /******************* ws request part for server *****************/
 360
 361 void afb_proto_ws_call_addref(struct afb_proto_ws_call *call)
 362 {
 363         __atomic_add_fetch(&call->refcount, 1, __ATOMIC_RELAXED);
 364 }
 365
 366 void afb_proto_ws_call_unref(struct afb_proto_ws_call *call)
 367 {
 368         if (__atomic_sub_fetch(&call->refcount, 1, __ATOMIC_RELAXED))
 369                 return;
 370
 371         afb_proto_ws_unref(call->protows);
 372         free(call->buffer);
 373         free(call);
 374 }
 375
 376 int afb_proto_ws_call_reply(struct afb_proto_ws_call *call, struct json_object *obj, const char *error, const char *info)
 377 {
 378         int rc = -1;
 379         struct writebuf wb = { .count = 0 };
 380         struct afb_proto_ws *protows = call->protows;
 381
 382         if (writebuf_char(&wb, CHAR_FOR_REPLY)
 383          && writebuf_uint32(&wb, call->callid)
 384          && writebuf_nullstring(&wb, error)
 385          && writebuf_nullstring(&wb, info)
 386          && writebuf_object(&wb, obj)) {
 387                 pthread_mutex_lock(&protows->mutex);
 388                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 389                 pthread_mutex_unlock(&protows->mutex);
 390                 if (rc >= 0) {
 391                         rc = 0;
 392                         goto success;
 393                 }
 394         }
 395 success:
 396         return rc;
 397 }
 398
 399 int afb_proto_ws_call_subscribe(struct afb_proto_ws_call *call, const char *event_name, int event_id)
 400 {
 401         int rc = -1;
 402         struct writebuf wb = { .count = 0 };
 403         struct afb_proto_ws *protows = call->protows;
 404
 405         if (writebuf_char(&wb, CHAR_FOR_EVT_SUBSCRIBE)
 406          && writebuf_uint32(&wb, call->callid)
 407          && writebuf_uint32(&wb, (uint32_t)event_id)
 408          && writebuf_string(&wb, event_name)) {
 409                 pthread_mutex_lock(&protows->mutex);
 410                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 411                 pthread_mutex_unlock(&protows->mutex);
 412                 if (rc >= 0) {
 413                         rc = 0;
 414                         goto success;
 415                 }
 416         }
 417 success:
 418         return rc;
 419 }
 420
 421 int afb_proto_ws_call_unsubscribe(struct afb_proto_ws_call *call, const char *event_name, int event_id)
 422 {
 423         int rc = -1;
 424         struct writebuf wb = { .count = 0 };
 425         struct afb_proto_ws *protows = call->protows;
 426
 427         if (writebuf_char(&wb, CHAR_FOR_EVT_UNSUBSCRIBE)
 428          && writebuf_uint32(&wb, call->callid)
 429          && writebuf_uint32(&wb, (uint32_t)event_id)
 430          && writebuf_string(&wb, event_name)) {
 431                 pthread_mutex_lock(&protows->mutex);
 432                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 433                 pthread_mutex_unlock(&protows->mutex);
 434                 if (rc >= 0) {
 435                         rc = 0;
 436                         goto success;
 437                 }
 438         }
 439 success:
 440         return rc;
 441 }
 442
 443 /******************* client part **********************************/
 444
 445 /* search a memorized call */
 446 static struct client_call *client_call_search_locked(struct afb_proto_ws *protows, uint32_t callid)
 447 {
 448         struct client_call *call;
 449
 450         call = protows->calls;
 451         while (call != NULL && call->callid != callid)
 452                 call = call->next;
 453
 454         return call;
 455 }
 456
 457 static struct client_call *client_call_search_unlocked(struct afb_proto_ws *protows, uint32_t callid)
 458 {
 459         struct client_call *result;
 460
 461         pthread_mutex_lock(&protows->mutex);
 462         result = client_call_search_locked(protows, callid);
 463         pthread_mutex_unlock(&protows->mutex);
 464         return result;
 465 }
 466
 467 /* free and release the memorizing call */
 468 static void client_call_destroy(struct client_call *call)
 469 {
 470         struct client_call **prv;
 471         struct afb_proto_ws *protows = call->protows;
 472
 473         pthread_mutex_lock(&protows->mutex);
 474         prv = &call->protows->calls;
 475         while (*prv != NULL) {
 476                 if (*prv == call) {
 477                         *prv = call->next;
 478                         break;
 479                 }
 480                 prv = &(*prv)->next;
 481         }
 482         pthread_mutex_unlock(&protows->mutex);
 483         free(call);
 484 }
 485
 486 /* get event data from the message */
 487 static int client_msg_event_read(struct readbuf *rb, uint32_t *eventid, const char **name)
 488 {
 489         return readbuf_uint32(rb, eventid) && readbuf_string(rb, name, NULL);
 490 }
 491
 492 /* get event from the message */
 493 static int client_msg_call_get(struct afb_proto_ws *protows, struct readbuf *rb, struct client_call **call)
 494 {
 495         uint32_t callid;
 496
 497         /* get event data from the message */
 498         if (!readbuf_uint32(rb, &callid)) {
 499                 return 0;
 500         }
 501
 502         /* get the call */
 503         *call = client_call_search_unlocked(protows, callid);
 504         if (*call == NULL) {
 505                 return 0;
 506         }
 507
 508         return 1;
 509 }
 510
 511 /* adds an event */
 512 static void client_on_event_create(struct afb_proto_ws *protows, struct readbuf *rb)
 513 {
 514         const char *event_name;
 515         uint32_t event_id;
 516
 517         if (protows->client_itf->on_event_create && client_msg_event_read(rb, &event_id, &event_name))
 518                 protows->client_itf->on_event_create(protows->closure, event_name, (int)event_id);
 519         else
 520                 ERROR("Ignoring creation of event");
 521 }
 522
 523 /* removes an event */
 524 static void client_on_event_remove(struct afb_proto_ws *protows, struct readbuf *rb)
 525 {
 526         const char *event_name;
 527         uint32_t event_id;
 528
 529         if (protows->client_itf->on_event_remove && client_msg_event_read(rb, &event_id, &event_name))
 530                 protows->client_itf->on_event_remove(protows->closure, event_name, (int)event_id);
 531         else
 532                 ERROR("Ignoring deletion of event");
 533 }
 534
 535 /* subscribes an event */
 536 static void client_on_event_subscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 537 {
 538         const char *event_name;
 539         uint32_t event_id;
 540         struct client_call *call;
 541
 542         if (protows->client_itf->on_event_subscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 543                 protows->client_itf->on_event_subscribe(protows->closure, call->request, event_name, (int)event_id);
 544         else
 545                 ERROR("Ignoring subscription to event");
 546 }
 547
 548 /* unsubscribes an event */
 549 static void client_on_event_unsubscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 550 {
 551         const char *event_name;
 552         uint32_t event_id;
 553         struct client_call *call;
 554
 555         if (protows->client_itf->on_event_unsubscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 556                 protows->client_itf->on_event_unsubscribe(protows->closure, call->request, event_name, (int)event_id);
 557         else
 558                 ERROR("Ignoring unsubscription to event");
 559 }
 560
 561 /* receives broadcasted events */
 562 static void client_on_event_broadcast(struct afb_proto_ws *protows, struct readbuf *rb)
 563 {
 564         const char *event_name;
 565         struct json_object *object;
 566
 567         if (protows->client_itf->on_event_broadcast && readbuf_string(rb, &event_name, NULL) && readbuf_object(rb, &object))
 568                 protows->client_itf->on_event_broadcast(protows->closure, event_name, object);
 569         else
 570                 ERROR("Ignoring broadcast of event");
 571 }
 572
 573 /* pushs an event */
 574 static void client_on_event_push(struct afb_proto_ws *protows, struct readbuf *rb)
 575 {
 576         const char *event_name;
 577         uint32_t event_id;
 578         struct json_object *object;
 579
 580         if (protows->client_itf->on_event_push && client_msg_event_read(rb, &event_id, &event_name) && readbuf_object(rb, &object))
 581                 protows->client_itf->on_event_push(protows->closure, event_name, (int)event_id, object);
 582         else
 583                 ERROR("Ignoring push of event");
 584 }
 585
 586 static void client_on_reply(struct afb_proto_ws *protows, struct readbuf *rb)
 587 {
 588         struct client_call *call;
 589         struct json_object *object;
 590         const char *error, *info;
 591
 592         if (!client_msg_call_get(protows, rb, &call))
 593                 return;
 594
 595         if (readbuf_nullstring(rb, &error, NULL) && readbuf_nullstring(rb, &info, NULL) && readbuf_object(rb, &object)) {
 596                 protows->client_itf->on_reply(protows->closure, call->request, object, error, info);
 597         } else {
 598                 protows->client_itf->on_reply(protows->closure, call->request, NULL, "proto-error", "can't process success");
 599         }
 600         client_call_destroy(call);
 601 }
 602
 603 static void client_on_description(struct afb_proto_ws *protows, struct readbuf *rb)
 604 {
 605         uint32_t descid;
 606         struct client_describe *desc, **prv;
 607         struct json_object *object;
 608
 609         if (readbuf_uint32(rb, &descid)) {
 610                 pthread_mutex_lock(&protows->mutex);
 611                 prv = &protows->describes;
 612                 while ((desc = *prv) && desc->descid != descid)
 613                         prv = &desc->next;
 614                 if (!desc)
 615                         pthread_mutex_unlock(&protows->mutex);
 616                 else {
 617                         *prv = desc->next;
 618                         pthread_mutex_unlock(&protows->mutex);
 619                         if (!readbuf_object(rb, &object))
 620                                 object = NULL;
 621                         desc->callback(desc->closure, object);
 622                         free(desc);
 623                 }
 624         }
 625 }
 626
 627 /* callback when receiving binary data */
 628 static void client_on_binary_job(int sig, void *closure)
 629 {
 630         struct binary *binary = closure;
 631
 632         if (!sig) {
 633                 switch (*binary->rb.head++) {
 634                 case CHAR_FOR_REPLY: /* reply */
 635                         client_on_reply(binary->protows, &binary->rb);
 636                         break;
 637                 case CHAR_FOR_EVT_BROADCAST: /* broadcast */
 638                         client_on_event_broadcast(binary->protows, &binary->rb);
 639                         break;
 640                 case CHAR_FOR_EVT_ADD: /* creates the event */
 641                         client_on_event_create(binary->protows, &binary->rb);
 642                         break;
 643                 case CHAR_FOR_EVT_DEL: /* removes the event */
 644                         client_on_event_remove(binary->protows, &binary->rb);
 645                         break;
 646                 case CHAR_FOR_EVT_PUSH: /* pushs the event */
 647                         client_on_event_push(binary->protows, &binary->rb);
 648                         break;
 649                 case CHAR_FOR_EVT_SUBSCRIBE: /* subscribe event for a request */
 650                         client_on_event_subscribe(binary->protows, &binary->rb);
 651                         break;
 652                 case CHAR_FOR_EVT_UNSUBSCRIBE: /* unsubscribe event for a request */
 653                         client_on_event_unsubscribe(binary->protows, &binary->rb);
 654                         break;
 655                 case CHAR_FOR_DESCRIPTION: /* description */
 656                         client_on_description(binary->protows, &binary->rb);
 657                         break;
 658                 default: /* unexpected message */
 659                         /* TODO: close the connection */
 660                         break;
 661                 }
 662         }
 663         free(binary->rb.base);
 664         free(binary);
 665 }
 666
 667 /* callback when receiving binary data */
 668 static void client_on_binary(void *closure, char *data, size_t size)
 669 {
 670         struct afb_proto_ws *protows = closure;
 671
 672         queue_message_processing(protows, data, size, client_on_binary_job);
 673 }
 674
 675 int afb_proto_ws_client_call(
 676                 struct afb_proto_ws *protows,
 677                 const char *verb,
 678                 struct json_object *args,
 679                 const char *sessionid,
 680                 void *request,
 681                 const char *user_creds
 682 )
 683 {
 684         int rc = -1;
 685         struct client_call *call;
 686         struct writebuf wb = { .count = 0 };
 687
 688         /* allocate call data */
 689         call = malloc(sizeof *call);
 690         if (call == NULL) {
 691                 errno = ENOMEM;
 692                 return -1;
 693         }
 694         call->request = request;
 695
 696         /* init call data */
 697         pthread_mutex_lock(&protows->mutex);
 698         call->callid = ptr2id(call);
 699         while(client_call_search_locked(protows, call->callid) != NULL)
 700                 call->callid++;
 701         call->protows = protows;
 702         call->next = protows->calls;
 703         protows->calls = call;
 704         pthread_mutex_unlock(&protows->mutex);
 705
 706         /* creates the call message */
 707         if (!writebuf_char(&wb, CHAR_FOR_CALL)
 708          || !writebuf_uint32(&wb, call->callid)
 709          || !writebuf_string(&wb, verb)
 710          || !writebuf_string(&wb, sessionid)
 711          || !writebuf_object(&wb, args)
 712          || !writebuf_nullstring(&wb, user_creds)) {
 713                 errno = EINVAL;
 714                 goto clean;
 715         }
 716
 717         /* send */
 718         pthread_mutex_lock(&protows->mutex);
 719         rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 720         pthread_mutex_unlock(&protows->mutex);
 721         if (rc >= 0) {
 722                 rc = 0;
 723                 goto end;
 724         }
 725
 726 clean:
 727         client_call_destroy(call);
 728 end:
 729         return rc;
 730 }
 731
 732 /* get the description */
 733 int afb_proto_ws_client_describe(struct afb_proto_ws *protows, void (*callback)(void*, struct json_object*), void *closure)
 734 {
 735         struct client_describe *desc, *d;
 736         struct writebuf wb = { .count = 0 };
 737
 738         desc = malloc(sizeof *desc);
 739         if (!desc) {
 740                 errno = ENOMEM;
 741                 goto error;
 742         }
 743
 744         /* fill in stack the description of the task */
 745         pthread_mutex_lock(&protows->mutex);
 746         desc->descid = ptr2id(desc);
 747         d = protows->describes;
 748         while (d) {
 749                 if (d->descid != desc->descid)
 750                         d = d->next;
 751                 else {
 752                         desc->descid++;
 753                         d = protows->describes;
 754                 }
 755         }
 756         desc->callback = callback;
 757         desc->closure = closure;
 758         desc->protows = protows;
 759         desc->next = protows->describes;
 760         protows->describes = desc;
 761
 762         /* send */
 763         if (writebuf_char(&wb, CHAR_FOR_DESCRIBE)
 764          && writebuf_uint32(&wb, desc->descid)
 765          && afb_ws_binary_v(protows->ws, wb.iovec, wb.count) >= 0) {
 766                 pthread_mutex_unlock(&protows->mutex);
 767                 return 0;
 768         }
 769
 770         d = protows->describes;
 771         if (d == desc)
 772                 protows->describes = desc->next;
 773         else {
 774                 while(d && d->next != desc)
 775                         d = d->next;
 776                 if (d)
 777                         d->next = desc->next;
 778         }
 779         pthread_mutex_unlock(&protows->mutex);
 780         free(desc);
 781 error:
 782         /* TODO? callback(closure, NULL); */
 783         return -1;
 784 }
 785
 786 /******************* client description part for server *****************************/
 787
 788 /* on call, propagate it to the ws service */
 789 static void server_on_call(struct afb_proto_ws *protows, struct readbuf *rb)
 790 {
 791         struct afb_proto_ws_call *call;
 792         const char *uuid, *verb, *user_creds;
 793         uint32_t callid;
 794         size_t lenverb;
 795         struct json_object *object;
 796
 797         afb_proto_ws_addref(protows);
 798
 799         /* reads the call message data */
 800         if (!readbuf_uint32(rb, &callid)
 801          || !readbuf_string(rb, &verb, &lenverb)
 802          || !readbuf_string(rb, &uuid, NULL)
 803          || !readbuf_object(rb, &object)
 804          || !readbuf_nullstring(rb, &user_creds, NULL))
 805                 goto overflow;
 806
 807         /* create the request */
 808         call = malloc(sizeof *call);
 809         if (call == NULL)
 810                 goto out_of_memory;
 811
 812         call->protows = protows;
 813         call->callid = callid;
 814         call->refcount = 1;
 815         call->buffer = rb->base;
 816         rb->base = NULL; /* don't free the buffer */
 817
 818         protows->server_itf->on_call(protows->closure, call, verb, object, uuid, user_creds);
 819         return;
 820
 821 out_of_memory:
 822         json_object_put(object);
 823
 824 overflow:
 825         afb_proto_ws_unref(protows);
 826 }
 827
 828 static int server_send_description(struct afb_proto_ws *protows, uint32_t descid, struct json_object *descobj)
 829 {
 830         int rc;
 831         struct writebuf wb = { .count = 0 };
 832
 833         if (writebuf_char(&wb, CHAR_FOR_DESCRIPTION)
 834          && writebuf_uint32(&wb, descid)
 835          && writebuf_object(&wb, descobj)) {
 836                 pthread_mutex_lock(&protows->mutex);
 837                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 838                 pthread_mutex_unlock(&protows->mutex);
 839                 if (rc >= 0)
 840                         return 0;
 841         }
 842         return -1;
 843 }
 844
 845 int afb_proto_ws_describe_put(struct afb_proto_ws_describe *describe, struct json_object *description)
 846 {
 847         int rc = server_send_description(describe->protows, describe->descid, description);
 848         afb_proto_ws_unref(describe->protows);
 849         free(describe);
 850         return rc;
 851 }
 852
 853 /* on describe, propagate it to the ws service */
 854 static void server_on_describe(struct afb_proto_ws *protows, struct readbuf *rb)
 855 {
 856         uint32_t descid;
 857         struct afb_proto_ws_describe *desc;
 858
 859         /* reads the descid */
 860         if (readbuf_uint32(rb, &descid)) {
 861                 if (protows->server_itf->on_describe) {
 862                         /* create asynchronous job */
 863                         desc = malloc(sizeof *desc);
 864                         if (desc) {
 865                                 desc->descid = descid;
 866                                 desc->protows = protows;
 867                                 afb_proto_ws_addref(protows);
 868                                 protows->server_itf->on_describe(protows->closure, desc);
 869                                 return;
 870                         }
 871                 }
 872                 server_send_description(protows, descid, NULL);
 873         }
 874 }
 875
 876 /* callback when receiving binary data */
 877 static void server_on_binary_job(int sig, void *closure)
 878 {
 879         struct binary *binary = closure;
 880
 881         if (!sig) {
 882                 switch (*binary->rb.head++) {
 883                 case CHAR_FOR_CALL:
 884                         server_on_call(binary->protows, &binary->rb);
 885                         break;
 886                 case CHAR_FOR_DESCRIBE:
 887                         server_on_describe(binary->protows, &binary->rb);
 888                         break;
 889                 default: /* unexpected message */
 890                         /* TODO: close the connection */
 891                         break;
 892                 }
 893         }
 894         free(binary->rb.base);
 895         free(binary);
 896 }
 897
 898 static void server_on_binary(void *closure, char *data, size_t size)
 899 {
 900         struct afb_proto_ws *protows = closure;
 901
 902         queue_message_processing(protows, data, size, server_on_binary_job);
 903 }
 904
 905 /******************* server part: manage events **********************************/
 906
 907 static int server_event_send(struct afb_proto_ws *protows, char order, const char *event_name, int event_id, struct json_object *data)
 908 {
 909         struct writebuf wb = { .count = 0 };
 910         int rc;
 911
 912         if (writebuf_char(&wb, order)
 913          && (order == CHAR_FOR_EVT_BROADCAST || writebuf_uint32(&wb, event_id))
 914          && writebuf_string(&wb, event_name)
 915          && (order == CHAR_FOR_EVT_ADD || order == CHAR_FOR_EVT_DEL || writebuf_object(&wb, data))) {
 916                 pthread_mutex_lock(&protows->mutex);
 917                 rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 918                 pthread_mutex_unlock(&protows->mutex);
 919                 if (rc >= 0)
 920                         return 0;
 921         }
 922         return -1;
 923 }
 924
 925 int afb_proto_ws_server_event_create(struct afb_proto_ws *protows, const char *event_name, int event_id)
 926 {
 927         return server_event_send(protows, CHAR_FOR_EVT_ADD, event_name, event_id, NULL);
 928 }
 929
 930 int afb_proto_ws_server_event_remove(struct afb_proto_ws *protows, const char *event_name, int event_id)
 931 {
 932         return server_event_send(protows, CHAR_FOR_EVT_DEL, event_name, event_id, NULL);
 933 }
 934
 935 int afb_proto_ws_server_event_push(struct afb_proto_ws *protows, const char *event_name, int event_id, struct json_object *data)
 936 {
 937         return server_event_send(protows, CHAR_FOR_EVT_PUSH, event_name, event_id, data);
 938 }
 939
 940 int afb_proto_ws_server_event_broadcast(struct afb_proto_ws *protows, const char *event_name, struct json_object *data)
 941 {
 942         return server_event_send(protows, CHAR_FOR_EVT_BROADCAST, event_name, 0, data);
 943 }
 944
 945 /*****************************************************/
 946
 947 /* callback when receiving a hangup */
 948 static void on_hangup(void *closure)
 949 {
 950         struct afb_proto_ws *protows = closure;
 951         struct client_describe *cd, *ncd;
 952         struct client_call *call, *ncall;
 953
 954         ncd = __atomic_exchange_n(&protows->describes, NULL, __ATOMIC_RELAXED);
 955         ncall = __atomic_exchange_n(&protows->calls, NULL, __ATOMIC_RELAXED);
 956
 957         while (ncall) {
 958                 call= ncall;
 959                 ncall = call->next;
 960                 protows->client_itf->on_reply(protows->closure, call->request, NULL, "disconnected", "server hung up");
 961                 free(call);
 962         }
 963
 964         while (ncd) {
 965                 cd= ncd;
 966                 ncd = cd->next;
 967                 cd->callback(cd->closure, NULL);
 968                 free(cd);
 969         }
 970
 971         if (protows->fdev) {
 972                 fdev_unref(protows->fdev);
 973                 protows->fdev = 0;
 974                 if (protows->on_hangup)
 975                         protows->on_hangup(protows->closure);
 976         }
 977 }
 978
 979 /*****************************************************/
 980
 981 static const struct afb_ws_itf proto_ws_client_ws_itf =
 982 {
 983         .on_close = NULL,
 984         .on_text = NULL,
 985         .on_binary = client_on_binary,
 986         .on_error = NULL,
 987         .on_hangup = on_hangup
 988 };
 989
 990 static const struct afb_ws_itf server_ws_itf =
 991 {
 992         .on_close = NULL,
 993         .on_text = NULL,
 994         .on_binary = server_on_binary,
 995         .on_error = NULL,
 996         .on_hangup = on_hangup
 997 };
 998
 999 /*****************************************************/
1000
1001 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)
1002 {
1003         struct afb_proto_ws *protows;
1004
1005         protows = calloc(1, sizeof *protows);
1006         if (protows == NULL)
1007                 errno = ENOMEM;
1008         else {
1009                 fcntl(fdev_fd(fdev), F_SETFD, FD_CLOEXEC);
1010                 fcntl(fdev_fd(fdev), F_SETFL, O_NONBLOCK);
1011                 protows->ws = afb_ws_create(fdev, itf, protows);
1012                 if (protows->ws != NULL) {
1013                         protows->fdev = fdev;
1014                         protows->refcount = 1;
1015                         protows->closure = closure;
1016                         protows->server_itf = itfs;
1017                         protows->client_itf = itfc;
1018                         pthread_mutex_init(&protows->mutex, NULL);
1019                         return protows;
1020                 }
1021                 free(protows);
1022         }
1023         return NULL;
1024 }
1025
1026 struct afb_proto_ws *afb_proto_ws_create_client(struct fdev *fdev, const struct afb_proto_ws_client_itf *itf, void *closure)
1027 {
1028         return afb_proto_ws_create(fdev, NULL, itf, closure, &proto_ws_client_ws_itf);
1029 }
1030
1031 struct afb_proto_ws *afb_proto_ws_create_server(struct fdev *fdev, const struct afb_proto_ws_server_itf *itf, void *closure)
1032 {
1033         return afb_proto_ws_create(fdev, itf, NULL, closure, &server_ws_itf);
1034 }
1035
1036 void afb_proto_ws_unref(struct afb_proto_ws *protows)
1037 {
1038         if (protows && !__atomic_sub_fetch(&protows->refcount, 1, __ATOMIC_RELAXED)) {
1039                 afb_proto_ws_hangup(protows);
1040                 afb_ws_destroy(protows->ws);
1041                 pthread_mutex_destroy(&protows->mutex);
1042                 free(protows);
1043         }
1044 }
1045
1046 void afb_proto_ws_addref(struct afb_proto_ws *protows)
1047 {
1048         __atomic_add_fetch(&protows->refcount, 1, __ATOMIC_RELAXED);
1049 }
1050
1051 int afb_proto_ws_is_client(struct afb_proto_ws *protows)
1052 {
1053         return !!protows->client_itf;
1054 }
1055
1056 int afb_proto_ws_is_server(struct afb_proto_ws *protows)
1057 {
1058         return !!protows->server_itf;
1059 }
1060
1061 void afb_proto_ws_hangup(struct afb_proto_ws *protows)
1062 {
1063         afb_ws_hangup(protows->ws);
1064 }
1065
1066 void afb_proto_ws_on_hangup(struct afb_proto_ws *protows, void (*on_hangup)(void *closure))
1067 {
1068         protows->on_hangup = on_hangup;
1069 }
1070
1071 void afb_proto_ws_set_queuing(struct afb_proto_ws *protows, int (*queuing)(void (*)(int,void*), void*))
1072 {
1073         protows->queuing = queuing;
1074 }