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