src/afb-proto-ws.c

   1 /*
   2  * Copyright (C) 2015, 2016, 2017 "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 #include <systemd/sd-event.h>
  37
  38 #include "afb-common.h"
  39
  40 #include "afb-ws.h"
  41 #include "afb-msg-json.h"
  42 #include "afb-proto-ws.h"
  43 #include "verbose.h"
  44
  45 struct afb_proto_ws;
  46
  47 /******** implementation of internal binder protocol per api **************/
  48 /*
  49
  50 This protocol is asymetric: there is a client and a server
  51
  52 The client can require the following actions:
  53
  54   - call a verb
  55
  56   - ask for description
  57
  58 The server must reply to the previous actions by
  59
  60   - answering success or failure of the call
  61
  62   - answering the required description
  63
  64 The server can also within the context of a call
  65
  66   - make a subcall
  67
  68   - subscribe or unsubscribe an event
  69
  70 For the purpose of handling events the server can:
  71
  72   - create/destroy an event
  73
  74   - push or brodcast data as an event
  75
  76 */
  77 /************** constants for protocol definition *************************/
  78
  79 #define CHAR_FOR_CALL             'C'
  80 #define CHAR_FOR_ANSWER_SUCCESS   'T'
  81 #define CHAR_FOR_ANSWER_FAIL      'F'
  82 #define CHAR_FOR_EVT_BROADCAST    '*'
  83 #define CHAR_FOR_EVT_ADD          '+'
  84 #define CHAR_FOR_EVT_DEL          '-'
  85 #define CHAR_FOR_EVT_PUSH         '!'
  86 #define CHAR_FOR_EVT_SUBSCRIBE    'S'
  87 #define CHAR_FOR_EVT_UNSUBSCRIBE  'U'
  88 #define CHAR_FOR_SUBCALL_CALL     'B'
  89 #define CHAR_FOR_SUBCALL_REPLY    'R'
  90 #define CHAR_FOR_DESCRIBE         'D'
  91 #define CHAR_FOR_DESCRIPTION      'd'
  92
  93 /******************* handling subcalls *****************************/
  94
  95 /**
  96  * Structure on server side for recording pending
  97  * subcalls.
  98  */
  99 struct server_subcall
 100 {
 101         struct server_subcall *next;    /**< next subcall for the client */
 102         uint32_t subcallid;             /**< the subcallid */
 103         void (*callback)(void*, int, struct json_object*); /**< callback on completion */
 104         void *closure;                  /**< closure of the callback */
 105 };
 106
 107 /**
 108  * Structure for sending back replies on client side
 109  */
 110 struct afb_proto_ws_subcall
 111 {
 112         struct afb_proto_ws *protows;   /**< proto descriptor */
 113         void *buffer;
 114         uint32_t subcallid;             /**< subcallid for the reply */
 115 };
 116
 117 /*
 118  * structure for recording calls on client side
 119  */
 120 struct client_call {
 121         struct client_call *next;       /* the next call */
 122         struct afb_proto_ws *protows;   /* the proto_ws */
 123         void *request;
 124         uint32_t callid;                /* the message identifier */
 125 };
 126
 127 /*
 128  * structure for a ws request
 129  */
 130 struct afb_proto_ws_call {
 131         struct client_call *next;       /* the next call */
 132         struct afb_proto_ws *protows;   /* the client of the request */
 133         uint32_t refcount;              /* reference count */
 134         uint32_t callid;                /* the incoming request callid */
 135         char *buffer;                   /* the incoming buffer */
 136 };
 137
 138 /*
 139  * structure for recording describe requests
 140  */
 141 struct client_describe
 142 {
 143         struct client_describe *next;
 144         struct afb_proto_ws *protows;
 145         void (*callback)(void*, struct json_object*);
 146         void *closure;
 147         uint32_t descid;
 148 };
 149
 150 /*
 151  * structure for jobs of describing
 152  */
 153 struct afb_proto_ws_describe
 154 {
 155         struct afb_proto_ws *protows;
 156         uint32_t descid;
 157 };
 158
 159 /******************* proto description for client or servers ******************/
 160
 161 struct afb_proto_ws
 162 {
 163         /* count of references */
 164         int refcount;
 165
 166         /* file descriptor */
 167         int fd;
 168
 169         /* resource control */
 170         pthread_mutex_t mutex;
 171
 172         /* websocket */
 173         struct afb_ws *ws;
 174
 175         /* the client closure */
 176         void *closure;
 177
 178         /* the client side interface */
 179         const struct afb_proto_ws_client_itf *client_itf;
 180
 181         /* the server side interface */
 182         const struct afb_proto_ws_server_itf *server_itf;
 183
 184         /* emitted calls (client side) */
 185         struct client_call *calls;
 186
 187         /* pending subcalls (server side) */
 188         struct server_subcall *subcalls;
 189
 190         /* pending description (client side) */
 191         struct client_describe *describes;
 192
 193         /* on hangup callback */
 194         void (*on_hangup)(void *closure);
 195 };
 196
 197 /******************* common useful tools **********************************/
 198
 199 /**
 200  * translate a pointer to some integer
 201  * @param ptr the pointer to translate
 202  * @return an integer
 203  */
 204 static inline uint32_t ptr2id(void *ptr)
 205 {
 206         return (uint32_t)(((intptr_t)ptr) >> 6);
 207 }
 208
 209 /******************* serialisation part **********************************/
 210
 211 struct readbuf
 212 {
 213         char *base, *head, *end;
 214 };
 215
 216 #define WRITEBUF_COUNT_MAX  32
 217 struct writebuf
 218 {
 219         struct iovec iovec[WRITEBUF_COUNT_MAX];
 220         uint32_t uints[WRITEBUF_COUNT_MAX];
 221         int count;
 222 };
 223
 224 static char *readbuf_get(struct readbuf *rb, uint32_t length)
 225 {
 226         char *before = rb->head;
 227         char *after = before + length;
 228         if (after > rb->end)
 229                 return 0;
 230         rb->head = after;
 231         return before;
 232 }
 233
 234 static int readbuf_char(struct readbuf *rb, char *value)
 235 {
 236         if (rb->head >= rb->end)
 237                 return 0;
 238         *value = *rb->head++;
 239         return 1;
 240 }
 241
 242 static int readbuf_uint32(struct readbuf *rb, uint32_t *value)
 243 {
 244         char *after = rb->head + sizeof *value;
 245         if (after > rb->end)
 246                 return 0;
 247         memcpy(value, rb->head, sizeof *value);
 248         rb->head = after;
 249         *value = le32toh(*value);
 250         return 1;
 251 }
 252
 253 static int readbuf_string(struct readbuf *rb, const char **value, size_t *length)
 254 {
 255         uint32_t len;
 256         if (!readbuf_uint32(rb, &len) || !len)
 257                 return 0;
 258         if (length)
 259                 *length = (size_t)(len - 1);
 260         return (*value = readbuf_get(rb, len)) != NULL &&  rb->head[-1] == 0;
 261 }
 262
 263 static int readbuf_object(struct readbuf *rb, struct json_object **object)
 264 {
 265         const char *string;
 266         struct json_object *o;
 267         int rc = readbuf_string(rb, &string, NULL);
 268         if (rc) {
 269                 o = json_tokener_parse(string);
 270                 if (o == NULL && strcmp(string, "null"))
 271                         o = json_object_new_string(string);
 272                 *object = o;
 273         }
 274         return rc;
 275 }
 276
 277 static int writebuf_put(struct writebuf *wb, const void *value, size_t length)
 278 {
 279         int i = wb->count;
 280         if (i == WRITEBUF_COUNT_MAX)
 281                 return 0;
 282         wb->iovec[i].iov_base = (void*)value;
 283         wb->iovec[i].iov_len = length;
 284         wb->count = i + 1;
 285         return 1;
 286 }
 287
 288 static int writebuf_char(struct writebuf *wb, char value)
 289 {
 290         int i = wb->count;
 291         if (i == WRITEBUF_COUNT_MAX)
 292                 return 0;
 293         *(char*)&wb->uints[i] = value;
 294         wb->iovec[i].iov_base = &wb->uints[i];
 295         wb->iovec[i].iov_len = 1;
 296         wb->count = i + 1;
 297         return 1;
 298 }
 299
 300 static int writebuf_uint32(struct writebuf *wb, uint32_t value)
 301 {
 302         int i = wb->count;
 303         if (i == WRITEBUF_COUNT_MAX)
 304                 return 0;
 305         wb->uints[i] = htole32(value);
 306         wb->iovec[i].iov_base = &wb->uints[i];
 307         wb->iovec[i].iov_len = sizeof wb->uints[i];
 308         wb->count = i + 1;
 309         return 1;
 310 }
 311
 312 static int writebuf_string_length(struct writebuf *wb, const char *value, size_t length)
 313 {
 314         uint32_t len = (uint32_t)++length;
 315         return (size_t)len == length && len && writebuf_uint32(wb, len) && writebuf_put(wb, value, length);
 316 }
 317
 318 static int writebuf_string(struct writebuf *wb, const char *value)
 319 {
 320         return writebuf_string_length(wb, value, strlen(value));
 321 }
 322
 323 static int writebuf_object(struct writebuf *wb, struct json_object *object)
 324 {
 325         const char *string = json_object_to_json_string_ext(object, JSON_C_TO_STRING_PLAIN);
 326         return string != NULL && writebuf_string(wb, string);
 327 }
 328
 329 /******************* ws request part for server *****************/
 330
 331 void afb_proto_ws_call_addref(struct afb_proto_ws_call *call)
 332 {
 333         __atomic_add_fetch(&call->refcount, 1, __ATOMIC_RELAXED);
 334 }
 335
 336 void afb_proto_ws_call_unref(struct afb_proto_ws_call *call)
 337 {
 338         if (__atomic_sub_fetch(&call->refcount, 1, __ATOMIC_RELAXED))
 339                 return;
 340
 341         afb_proto_ws_unref(call->protows);
 342         free(call->buffer);
 343         free(call);
 344 }
 345
 346 int afb_proto_ws_call_success(struct afb_proto_ws_call *call, struct json_object *obj, const char *info)
 347 {
 348         int rc = -1;
 349         struct writebuf wb = { .count = 0 };
 350
 351         if (writebuf_char(&wb, CHAR_FOR_ANSWER_SUCCESS)
 352          && writebuf_uint32(&wb, call->callid)
 353          && writebuf_string(&wb, info ?: "")
 354          && writebuf_object(&wb, obj)) {
 355                 rc = afb_ws_binary_v(call->protows->ws, wb.iovec, wb.count);
 356                 if (rc >= 0) {
 357                         rc = 0;
 358                         goto success;
 359                 }
 360         }
 361         ERROR("error while sending success");
 362 success:
 363         return rc;
 364 }
 365
 366 int afb_proto_ws_call_fail(struct afb_proto_ws_call *call, const char *status, const char *info)
 367 {
 368         int rc = -1;
 369         struct writebuf wb = { .count = 0 };
 370
 371         if (writebuf_char(&wb, CHAR_FOR_ANSWER_FAIL)
 372          && writebuf_uint32(&wb, call->callid)
 373          && writebuf_string(&wb, status)
 374          && writebuf_string(&wb, info ? : "")) {
 375                 rc = afb_ws_binary_v(call->protows->ws, wb.iovec, wb.count);
 376                 if (rc >= 0) {
 377                         rc = 0;
 378                         goto success;
 379                 }
 380         }
 381         ERROR("error while sending fail");
 382 success:
 383         return rc;
 384 }
 385
 386 int afb_proto_ws_call_subcall(struct afb_proto_ws_call *call, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *cb_closure)
 387 {
 388         int rc = -1;
 389         struct writebuf wb = { .count = 0 };
 390         struct server_subcall *sc, *osc;
 391         struct afb_proto_ws *protows = call->protows;
 392
 393         sc = malloc(sizeof *sc);
 394         if (!sc)
 395                 errno = ENOMEM;
 396         else {
 397                 sc->callback = callback;
 398                 sc->closure = cb_closure;
 399
 400                 pthread_mutex_unlock(&protows->mutex);
 401                 sc->subcallid = ptr2id(sc);
 402                 do {
 403                         sc->subcallid++;
 404                         osc = protows->subcalls;
 405                         while(osc && osc->subcallid != sc->subcallid)
 406                                 osc = osc->next;
 407                 } while (osc);
 408                 sc->next = protows->subcalls;
 409                 protows->subcalls = sc;
 410                 pthread_mutex_unlock(&protows->mutex);
 411
 412                 if (writebuf_char(&wb, CHAR_FOR_SUBCALL_CALL)
 413                  && writebuf_uint32(&wb, sc->subcallid)
 414                  && writebuf_uint32(&wb, call->callid)
 415                  && writebuf_string(&wb, api)
 416                  && writebuf_string(&wb, verb)
 417                  && writebuf_object(&wb, args)) {
 418                         rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 419                         if (rc >= 0) {
 420                                 rc = 0;
 421                                 goto success;
 422                         }
 423                 }
 424         }
 425         ERROR("error while sending subcall");
 426 success:
 427         return rc;
 428 }
 429
 430 int afb_proto_ws_call_subscribe(struct afb_proto_ws_call *call, const char *event_name, int event_id)
 431 {
 432         int rc = -1;
 433         struct writebuf wb = { .count = 0 };
 434
 435         if (writebuf_char(&wb, CHAR_FOR_EVT_SUBSCRIBE)
 436          && writebuf_uint32(&wb, call->callid)
 437          && writebuf_uint32(&wb, (uint32_t)event_id)
 438          && writebuf_string(&wb, event_name)) {
 439                 rc = afb_ws_binary_v(call->protows->ws, wb.iovec, wb.count);
 440                 if (rc >= 0) {
 441                         rc = 0;
 442                         goto success;
 443                 }
 444         }
 445         ERROR("error while subscribing event");
 446 success:
 447         return rc;
 448 }
 449
 450 int afb_proto_ws_call_unsubscribe(struct afb_proto_ws_call *call, const char *event_name, int event_id)
 451 {
 452         int rc = -1;
 453         struct writebuf wb = { .count = 0 };
 454
 455         if (writebuf_char(&wb, CHAR_FOR_EVT_UNSUBSCRIBE)
 456          && writebuf_uint32(&wb, call->callid)
 457          && writebuf_uint32(&wb, (uint32_t)event_id)
 458          && writebuf_string(&wb, event_name)) {
 459                 rc = afb_ws_binary_v(call->protows->ws, wb.iovec, wb.count);
 460                 if (rc >= 0) {
 461                         rc = 0;
 462                         goto success;
 463                 }
 464         }
 465         ERROR("error while subscribing event");
 466 success:
 467         return rc;
 468 }
 469
 470 /******************* client part **********************************/
 471
 472 /* search a memorized call */
 473 static struct client_call *client_call_search(struct afb_proto_ws *protows, uint32_t callid)
 474 {
 475         struct client_call *call;
 476
 477         call = protows->calls;
 478         while (call != NULL && call->callid != callid)
 479                 call = call->next;
 480
 481         return call;
 482 }
 483
 484 /* free and release the memorizing call */
 485 static void client_call_destroy(struct client_call *call)
 486 {
 487         struct client_call **prv;
 488
 489         prv = &call->protows->calls;
 490         while (*prv != NULL) {
 491                 if (*prv == call) {
 492                         *prv = call->next;
 493                         break;
 494                 }
 495                 prv = &(*prv)->next;
 496         }
 497         free(call);
 498 }
 499
 500 /* get event data from the message */
 501 static int client_msg_event_read(struct readbuf *rb, uint32_t *eventid, const char **name)
 502 {
 503         return readbuf_uint32(rb, eventid) && readbuf_string(rb, name, NULL);
 504 }
 505
 506 /* get event from the message */
 507 static int client_msg_call_get(struct afb_proto_ws *protows, struct readbuf *rb, struct client_call **call)
 508 {
 509         uint32_t callid;
 510
 511         /* get event data from the message */
 512         if (!readbuf_uint32(rb, &callid)) {
 513                 ERROR("Invalid message");
 514                 return 0;
 515         }
 516
 517         /* get the call */
 518         *call = client_call_search(protows, callid);
 519         if (*call == NULL) {
 520                 ERROR("message not found");
 521                 return 0;
 522         }
 523
 524         return 1;
 525 }
 526
 527 /* adds an event */
 528 static void client_on_event_create(struct afb_proto_ws *protows, struct readbuf *rb)
 529 {
 530         const char *event_name;
 531         uint32_t event_id;
 532
 533         if (protows->client_itf->on_event_create && client_msg_event_read(rb, &event_id, &event_name))
 534                 protows->client_itf->on_event_create(protows->closure, event_name, (int)event_id);
 535 }
 536
 537 /* removes an event */
 538 static void client_on_event_remove(struct afb_proto_ws *protows, struct readbuf *rb)
 539 {
 540         const char *event_name;
 541         uint32_t event_id;
 542
 543         if (protows->client_itf->on_event_remove && client_msg_event_read(rb, &event_id, &event_name))
 544                 protows->client_itf->on_event_remove(protows->closure, event_name, (int)event_id);
 545 }
 546
 547 /* subscribes an event */
 548 static void client_on_event_subscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 549 {
 550         const char *event_name;
 551         uint32_t event_id;
 552         struct client_call *call;
 553
 554         if (protows->client_itf->on_event_subscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 555                 protows->client_itf->on_event_subscribe(protows->closure, call->request, event_name, (int)event_id);
 556 }
 557
 558 /* unsubscribes an event */
 559 static void client_on_event_unsubscribe(struct afb_proto_ws *protows, struct readbuf *rb)
 560 {
 561         const char *event_name;
 562         uint32_t event_id;
 563         struct client_call *call;
 564
 565         if (protows->client_itf->on_event_unsubscribe && client_msg_call_get(protows, rb, &call) && client_msg_event_read(rb, &event_id, &event_name))
 566                 protows->client_itf->on_event_unsubscribe(protows->closure, call->request, event_name, (int)event_id);
 567 }
 568
 569 /* receives broadcasted events */
 570 static void client_on_event_broadcast(struct afb_proto_ws *protows, struct readbuf *rb)
 571 {
 572         const char *event_name;
 573         struct json_object *object;
 574
 575         if (protows->client_itf->on_event_broadcast && readbuf_string(rb, &event_name, NULL) && readbuf_object(rb, &object))
 576                 protows->client_itf->on_event_broadcast(protows->closure, event_name, object);
 577 }
 578
 579 /* pushs an event */
 580 static void client_on_event_push(struct afb_proto_ws *protows, struct readbuf *rb)
 581 {
 582         const char *event_name;
 583         uint32_t event_id;
 584         struct json_object *object;
 585
 586         if (protows->client_itf->on_event_push && client_msg_event_read(rb, &event_id, &event_name) && readbuf_object(rb, &object))
 587                 protows->client_itf->on_event_push(protows->closure, event_name, (int)event_id, object);
 588 }
 589
 590 static void client_on_reply_success(struct afb_proto_ws *protows, struct readbuf *rb)
 591 {
 592         struct client_call *call;
 593         struct json_object *object;
 594         const char *info;
 595
 596         if (!client_msg_call_get(protows, rb, &call))
 597                 return;
 598
 599         if (readbuf_string(rb, &info, NULL) && readbuf_object(rb, &object)) {
 600                 protows->client_itf->on_reply_success(protows->closure, call->request, object, info);
 601         } else {
 602                 protows->client_itf->on_reply_fail(protows->closure, call->request, "proto-error", "can't process success");
 603         }
 604         client_call_destroy(call);
 605 }
 606
 607 static void client_on_reply_fail(struct afb_proto_ws *protows, struct readbuf *rb)
 608 {
 609         struct client_call *call;
 610         const char *info, *status;
 611
 612         if (!client_msg_call_get(protows, rb, &call))
 613                 return;
 614
 615         if (readbuf_string(rb, &status, NULL) && readbuf_string(rb, &info, NULL)) {
 616                 protows->client_itf->on_reply_fail(protows->closure, call->request, status, info);
 617         } else {
 618                 protows->client_itf->on_reply_fail(protows->closure, call->request, "proto-error", "can't process fail");
 619         }
 620         client_call_destroy(call);
 621 }
 622
 623 /* send a subcall reply */
 624 static int client_send_subcall_reply(struct afb_proto_ws *protows, uint32_t subcallid, int status, json_object *object)
 625 {
 626         struct writebuf wb = { .count = 0 };
 627         char ie = status < 0;
 628
 629         return -!(writebuf_char(&wb, CHAR_FOR_SUBCALL_REPLY)
 630          && writebuf_uint32(&wb, subcallid)
 631          && writebuf_char(&wb, ie)
 632          && writebuf_object(&wb, object)
 633          && afb_ws_binary_v(protows->ws, wb.iovec, wb.count) >= 0);
 634 }
 635
 636 /* callback for subcall reply */
 637 int afb_proto_ws_subcall_reply(struct afb_proto_ws_subcall *subcall, int status, struct json_object *result)
 638 {
 639         int rc = client_send_subcall_reply(subcall->protows, subcall->subcallid, status, result);
 640         afb_proto_ws_unref(subcall->protows);
 641         free(subcall->buffer);
 642         free(subcall);
 643         return rc;
 644 }
 645
 646 /* received a subcall request */
 647 static void client_on_subcall(struct afb_proto_ws *protows, struct readbuf *rb)
 648 {
 649         struct afb_proto_ws_subcall *subcall;
 650         struct client_call *call;
 651         const char *api, *verb;
 652         uint32_t subcallid;
 653         struct json_object *object;
 654
 655         /* get the subcallid */
 656         if (!readbuf_uint32(rb, &subcallid))
 657                 return;
 658
 659         /* if not expected drop it */
 660         if (!protows->client_itf->on_subcall)
 661                 goto error;
 662
 663         /* retrieve the message data */
 664         if (!client_msg_call_get(protows, rb, &call))
 665                 goto error;
 666
 667         /* allocation of the subcall */
 668         subcall = malloc(sizeof *subcall);
 669         if (!subcall)
 670                 goto error;
 671
 672         /* make the call */
 673         if (readbuf_string(rb, &api, NULL)
 674          && readbuf_string(rb, &verb, NULL)
 675          && readbuf_object(rb, &object)) {
 676                 afb_proto_ws_addref(protows);
 677                 subcall->protows = protows;
 678                 subcall->subcallid = subcallid;
 679                 subcall->buffer = rb->base;
 680                 rb->base = NULL;
 681                 protows->client_itf->on_subcall(protows->closure, subcall, call->request, api, verb, object);
 682                 return;
 683         }
 684         free(subcall);
 685 error:
 686         client_send_subcall_reply(protows, subcallid, 1, NULL);
 687 }
 688
 689 static void client_on_description(struct afb_proto_ws *protows, struct readbuf *rb)
 690 {
 691         uint32_t descid;
 692         struct client_describe *desc, **prv;
 693         struct json_object *object;
 694
 695         if (readbuf_uint32(rb, &descid)) {
 696                 prv = &protows->describes;
 697                 while ((desc = *prv) && desc->descid != descid)
 698                         prv = &desc->next;
 699                 if (desc) {
 700                         *prv = desc->next;
 701                         if (!readbuf_object(rb, &object))
 702                                 object = NULL;
 703                         desc->callback(desc->closure, object);
 704                         free(desc);
 705                 }
 706         }
 707 }
 708
 709 /* callback when receiving binary data */
 710 static void client_on_binary(void *closure, char *data, size_t size)
 711 {
 712         struct afb_proto_ws *protows;
 713         struct readbuf rb;
 714
 715         rb.base = data;
 716         if (size > 0) {
 717                 rb.head = data;
 718                 rb.end = data + size;
 719                 protows = closure;
 720
 721                 pthread_mutex_lock(&protows->mutex);
 722                 switch (*rb.head++) {
 723                 case CHAR_FOR_ANSWER_SUCCESS: /* success */
 724                         client_on_reply_success(protows, &rb);
 725                         break;
 726                 case CHAR_FOR_ANSWER_FAIL: /* fail */
 727                         client_on_reply_fail(protows, &rb);
 728                         break;
 729                 case CHAR_FOR_EVT_BROADCAST: /* broadcast */
 730                         client_on_event_broadcast(protows, &rb);
 731                         break;
 732                 case CHAR_FOR_EVT_ADD: /* creates the event */
 733                         client_on_event_create(protows, &rb);
 734                         break;
 735                 case CHAR_FOR_EVT_DEL: /* removes the event */
 736                         client_on_event_remove(protows, &rb);
 737                         break;
 738                 case CHAR_FOR_EVT_PUSH: /* pushs the event */
 739                         client_on_event_push(protows, &rb);
 740                         break;
 741                 case CHAR_FOR_EVT_SUBSCRIBE: /* subscribe event for a request */
 742                         client_on_event_subscribe(protows, &rb);
 743                         break;
 744                 case CHAR_FOR_EVT_UNSUBSCRIBE: /* unsubscribe event for a request */
 745                         client_on_event_unsubscribe(protows, &rb);
 746                         break;
 747                 case CHAR_FOR_SUBCALL_CALL: /* subcall */
 748                         client_on_subcall(protows, &rb);
 749                         break;
 750                 case CHAR_FOR_DESCRIPTION: /* description */
 751                         client_on_description(protows, &rb);
 752                         break;
 753                 default: /* unexpected message */
 754                         /* TODO: close the connection */
 755                         break;
 756                 }
 757                 pthread_mutex_unlock(&protows->mutex);
 758         }
 759         free(rb.base);
 760 }
 761
 762 int afb_proto_ws_client_call(
 763                 struct afb_proto_ws *protows,
 764                 const char *verb,
 765                 struct json_object *args,
 766                 const char *sessionid,
 767                 void *request
 768 )
 769 {
 770         int rc = -1;
 771         struct client_call *call;
 772         struct writebuf wb = { .count = 0 };
 773
 774         /* allocate call data */
 775         call = malloc(sizeof *call);
 776         if (call == NULL) {
 777                 errno = ENOMEM;
 778                 return -1;
 779         }
 780         call->request = request;
 781
 782         /* init call data */
 783         pthread_mutex_lock(&protows->mutex);
 784         call->callid = ptr2id(call);
 785         while(client_call_search(protows, call->callid) != NULL)
 786                 call->callid++;
 787         call->protows = protows;
 788         call->next = protows->calls;
 789         protows->calls = call;
 790
 791         /* creates the call message */
 792         if (!writebuf_char(&wb, CHAR_FOR_CALL)
 793          || !writebuf_uint32(&wb, call->callid)
 794          || !writebuf_string(&wb, verb)
 795          || !writebuf_string(&wb, sessionid)
 796          || !writebuf_object(&wb, args)) {
 797                 errno = EINVAL;
 798                 goto clean;
 799         }
 800
 801         /* send */
 802         rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count);
 803         if (rc >= 0) {
 804                 rc = 0;
 805                 goto end;
 806         }
 807
 808 clean:
 809         client_call_destroy(call);
 810 end:
 811         pthread_mutex_unlock(&protows->mutex);
 812         return rc;
 813 }
 814
 815 /* get the description */
 816 int afb_proto_ws_client_describe(struct afb_proto_ws *protows, void (*callback)(void*, struct json_object*), void *closure)
 817 {
 818         struct client_describe *desc, *d;
 819         struct writebuf wb = { .count = 0 };
 820
 821         desc = malloc(sizeof *desc);
 822         if (!desc) {
 823                 errno = ENOMEM;
 824                 goto error;
 825         }
 826
 827         /* fill in stack the description of the task */
 828         pthread_mutex_lock(&protows->mutex);
 829         desc->descid = ptr2id(desc);
 830         d = protows->describes;
 831         while (d) {
 832                 if (d->descid != desc->descid)
 833                         d = d->next;
 834                 else {
 835                         desc->descid++;
 836                         d = protows->describes;
 837                 }
 838         }
 839         desc->callback = callback;
 840         desc->closure = closure;
 841         desc->protows = protows;
 842         desc->next = protows->describes;
 843         protows->describes = desc;
 844         pthread_mutex_unlock(&protows->mutex);
 845
 846         /* send */
 847         if (writebuf_char(&wb, CHAR_FOR_DESCRIBE)
 848          && writebuf_uint32(&wb, desc->descid)
 849          && afb_ws_binary_v(protows->ws, wb.iovec, wb.count) >= 0)
 850                 return 0;
 851
 852         pthread_mutex_lock(&protows->mutex);
 853         d = protows->describes;
 854         if (d == desc)
 855                 protows->describes = desc->next;
 856         else {
 857                 while(d && d->next != desc)
 858                         d = d->next;
 859                 if (d)
 860                         d->next = desc->next;
 861         }
 862         free(desc);
 863         pthread_mutex_unlock(&protows->mutex);
 864 error:
 865         /* TODO? callback(closure, NULL); */
 866         return -1;
 867 }
 868
 869 /******************* client description part for server *****************************/
 870
 871 /* on call, propagate it to the ws service */
 872 static void server_on_call(struct afb_proto_ws *protows, struct readbuf *rb)
 873 {
 874         struct afb_proto_ws_call *call;
 875         const char *uuid, *verb;
 876         uint32_t callid;
 877         size_t lenverb;
 878         struct json_object *object;
 879
 880         afb_proto_ws_addref(protows);
 881
 882         /* reads the call message data */
 883         if (!readbuf_uint32(rb, &callid)
 884          || !readbuf_string(rb, &verb, &lenverb)
 885          || !readbuf_string(rb, &uuid, NULL)
 886          || !readbuf_object(rb, &object))
 887                 goto overflow;
 888
 889         /* create the request */
 890         call = malloc(sizeof *call);
 891         if (call == NULL)
 892                 goto out_of_memory;
 893
 894         call->protows = protows;
 895         call->callid = callid;
 896         call->refcount = 1;
 897         call->buffer = rb->base;
 898         rb->base = NULL; /* don't free the buffer */
 899
 900         protows->server_itf->on_call(protows->closure, call, verb, object, uuid);
 901         return;
 902
 903 out_of_memory:
 904         json_object_put(object);
 905
 906 overflow:
 907         afb_proto_ws_unref(protows);
 908 }
 909
 910 /* on subcall reply */
 911 static void server_on_subcall_reply(struct afb_proto_ws *protows, struct readbuf *rb)
 912 {
 913         char ie;
 914         uint32_t subcallid;
 915         struct json_object *object;
 916         struct server_subcall *sc, **psc;
 917
 918         /* reads the call message data */
 919         if (!readbuf_uint32(rb, &subcallid)
 920          || !readbuf_char(rb, &ie)
 921          || !readbuf_object(rb, &object)) {
 922                 /* TODO bad protocol */
 923                 return;
 924         }
 925
 926         /* search the subcall and unlink it */
 927         pthread_mutex_lock(&protows->mutex);
 928         psc = &protows->subcalls;
 929         while ((sc = *psc) && sc->subcallid != subcallid)
 930                 psc = &sc->next;
 931         if (!sc) {
 932                 pthread_mutex_unlock(&protows->mutex);
 933                 json_object_put(object);
 934                 /* TODO subcall not found */
 935         } else {
 936                 *psc = sc->next;
 937                 pthread_mutex_unlock(&protows->mutex);
 938                 sc->callback(sc->closure, -(int)ie, object);
 939                 free(sc);
 940         }
 941 }
 942
 943 static int server_send_description(struct afb_proto_ws *protows, uint32_t descid, struct json_object *descobj)
 944 {
 945         struct writebuf wb = { .count = 0 };
 946
 947         return -!(writebuf_char(&wb, CHAR_FOR_DESCRIPTION)
 948                  && writebuf_uint32(&wb, descid)
 949                  && writebuf_object(&wb, descobj)
 950                  && afb_ws_binary_v(protows->ws, wb.iovec, wb.count) >= 0);
 951 }
 952
 953 int afb_proto_ws_describe_put(struct afb_proto_ws_describe *describe, struct json_object *description)
 954 {
 955         int rc = server_send_description(describe->protows, describe->descid, description);
 956         afb_proto_ws_addref(describe->protows);
 957         free(describe);
 958         return rc;
 959 }
 960
 961 /* on describe, propagate it to the ws service */
 962 static void server_on_describe(struct afb_proto_ws *protows, struct readbuf *rb)
 963 {
 964         uint32_t descid;
 965         struct afb_proto_ws_describe *desc;
 966
 967         /* reads the descid */
 968         if (readbuf_uint32(rb, &descid)) {
 969                 if (protows->server_itf->on_describe) {
 970                         /* create asynchronous job */
 971                         desc = malloc(sizeof *desc);
 972                         if (desc) {
 973                                 desc->descid = descid;
 974                                 desc->protows = protows;
 975                                 afb_proto_ws_addref(protows);
 976                                 protows->server_itf->on_describe(protows->closure, desc);
 977                                 return;
 978                         }
 979                 }
 980                 server_send_description(protows, descid, NULL);
 981         }
 982 }
 983
 984 /* callback when receiving binary data */
 985 static void server_on_binary(void *closure, char *data, size_t size)
 986 {
 987         struct afb_proto_ws *protows;
 988         struct readbuf rb;
 989
 990         rb.base = data;
 991         if (size > 0) {
 992                 rb.head = data;
 993                 rb.end = data + size;
 994                 protows = closure;
 995
 996                 switch (*rb.head++) {
 997                 case CHAR_FOR_CALL:
 998                         server_on_call(protows, &rb);
 999                         break;
1000                 case CHAR_FOR_SUBCALL_REPLY:
1001                         server_on_subcall_reply(protows, &rb);
1002                         break;
1003                 case CHAR_FOR_DESCRIBE:
1004                         server_on_describe(protows, &rb);
1005                         break;
1006                 default: /* unexpected message */
1007                         /* TODO: close the connection */
1008                         break;
1009                 }
1010         }
1011         free(rb.base);
1012 }
1013
1014 /******************* server part: manage events **********************************/
1015
1016 static int server_event_send(struct afb_proto_ws *protows, char order, const char *event_name, int event_id, struct json_object *data)
1017 {
1018         struct writebuf wb = { .count = 0 };
1019
1020         return -!(writebuf_char(&wb, order)
1021                  && (order == CHAR_FOR_EVT_BROADCAST || writebuf_uint32(&wb, event_id))
1022                  && writebuf_string(&wb, event_name)
1023                  && (order == CHAR_FOR_EVT_ADD || order == CHAR_FOR_EVT_DEL || writebuf_object(&wb, data))
1024                  && afb_ws_binary_v(protows->ws, wb.iovec, wb.count) >= 0);
1025 }
1026
1027 int afb_proto_ws_server_event_create(struct afb_proto_ws *protows, const char *event_name, int event_id)
1028 {
1029         return server_event_send(protows, CHAR_FOR_EVT_ADD, event_name, event_id, NULL);
1030 }
1031
1032 int afb_proto_ws_server_event_remove(struct afb_proto_ws *protows, const char *event_name, int event_id)
1033 {
1034         return server_event_send(protows, CHAR_FOR_EVT_DEL, event_name, event_id, NULL);
1035 }
1036
1037 int afb_proto_ws_server_event_push(struct afb_proto_ws *protows, const char *event_name, int event_id, struct json_object *data)
1038 {
1039         return server_event_send(protows, CHAR_FOR_EVT_PUSH, event_name, event_id, data);
1040 }
1041
1042 int afb_proto_ws_server_event_broadcast(struct afb_proto_ws *protows, const char *event_name, struct json_object *data)
1043 {
1044         return server_event_send(protows, CHAR_FOR_EVT_BROADCAST, event_name, 0, data);
1045 }
1046
1047 /*****************************************************/
1048
1049 /* callback when receiving a hangup */
1050 static void on_hangup(void *closure)
1051 {
1052         struct afb_proto_ws *protows = closure;
1053         struct server_subcall *sc, *nsc;
1054         struct client_describe *cd, *ncd;
1055
1056         nsc = protows->subcalls;
1057         while (nsc) {
1058                 sc= nsc;
1059                 nsc = sc->next;
1060                 sc->callback(sc->closure, 1, NULL);
1061                 free(sc);
1062         }
1063
1064         ncd = protows->describes;
1065         while (ncd) {
1066                 cd= ncd;
1067                 ncd = cd->next;
1068                 cd->callback(cd->closure, NULL);
1069                 free(cd);
1070         }
1071
1072         if (protows->fd >= 0) {
1073                 protows->fd = -1;
1074                 if (protows->on_hangup)
1075                         protows->on_hangup(protows->closure);
1076         }
1077 }
1078
1079 /*****************************************************/
1080
1081 static const struct afb_ws_itf proto_ws_client_ws_itf =
1082 {
1083         .on_close = NULL,
1084         .on_text = NULL,
1085         .on_binary = client_on_binary,
1086         .on_error = NULL,
1087         .on_hangup = on_hangup
1088 };
1089
1090 static const struct afb_ws_itf server_ws_itf =
1091 {
1092         .on_close = NULL,
1093         .on_text = NULL,
1094         .on_binary = server_on_binary,
1095         .on_error = NULL,
1096         .on_hangup = on_hangup
1097 };
1098
1099 /*****************************************************/
1100
1101 static struct afb_proto_ws *afb_proto_ws_create(int fd, const struct afb_proto_ws_server_itf *itfs, const struct afb_proto_ws_client_itf *itfc, void *closure, const struct afb_ws_itf *itf)
1102 {
1103         struct afb_proto_ws *protows;
1104
1105         protows = calloc(1, sizeof *protows);
1106         if (protows == NULL)
1107                 errno = ENOMEM;
1108         else {
1109                 fcntl(fd, F_SETFD, FD_CLOEXEC);
1110                 fcntl(fd, F_SETFL, O_NONBLOCK);
1111                 protows->ws = afb_ws_create(afb_common_get_event_loop(), fd, itf, protows);
1112                 if (protows->ws != NULL) {
1113                         protows->fd = fd;
1114                         protows->refcount = 1;
1115                         protows->subcalls = NULL;
1116                         protows->closure = closure;
1117                         protows->server_itf = itfs;
1118                         protows->client_itf = itfc;
1119                         pthread_mutex_init(&protows->mutex, NULL);
1120                         return protows;
1121                 }
1122                 free(protows);
1123         }
1124         return NULL;
1125 }
1126
1127 struct afb_proto_ws *afb_proto_ws_create_client(int fd, const struct afb_proto_ws_client_itf *itf, void *closure)
1128 {
1129         return afb_proto_ws_create(fd, NULL, itf, closure, &proto_ws_client_ws_itf);
1130 }
1131
1132 struct afb_proto_ws *afb_proto_ws_create_server(int fd, const struct afb_proto_ws_server_itf *itf, void *closure)
1133 {
1134         return afb_proto_ws_create(fd, itf, NULL, closure, &server_ws_itf);
1135 }
1136
1137 void afb_proto_ws_unref(struct afb_proto_ws *protows)
1138 {
1139         if (!__atomic_sub_fetch(&protows->refcount, 1, __ATOMIC_RELAXED)) {
1140                 afb_proto_ws_hangup(protows);
1141                 afb_ws_destroy(protows->ws);
1142                 pthread_mutex_destroy(&protows->mutex);
1143                 free(protows);
1144         }
1145 }
1146
1147 void afb_proto_ws_addref(struct afb_proto_ws *protows)
1148 {
1149         __atomic_add_fetch(&protows->refcount, 1, __ATOMIC_RELAXED);
1150 }
1151
1152 int afb_proto_ws_is_client(struct afb_proto_ws *protows)
1153 {
1154         return !!protows->client_itf;
1155 }
1156
1157 int afb_proto_ws_is_server(struct afb_proto_ws *protows)
1158 {
1159         return !!protows->server_itf;
1160 }
1161
1162 void afb_proto_ws_hangup(struct afb_proto_ws *protows)
1163 {
1164         afb_ws_hangup(protows->ws);
1165 }
1166
1167 void afb_proto_ws_on_hangup(struct afb_proto_ws *protows, void (*on_hangup)(void *closure))
1168 {
1169         protows->on_hangup = on_hangup;
1170 }
1171