libubus.c

   1 #include <sys/types.h>
   2 #include <sys/uio.h>
   3 #include <sys/socket.h>
   4 #include <unistd.h>
   5
   6 #include <libubox/blob.h>
   7 #include <libubox/blobmsg.h>
   8 #include <libubox/usock.h>
   9
  10 #include "libubus.h"
  11 #include "ubusmsg.h"
  12
  13 #define DEBUG 1
  14
  15 #ifdef DEBUG
  16 #define DPRINTF(_format, ...) fprintf(stderr, "ubus: " _format, ## __VA_ARGS__)
  17 #else
  18 #define DPRINTF(...) do {} while(0)
  19 #endif
  20
  21 #define STATIC_IOV(_var) { .iov_base = (char *) &(_var), .iov_len = sizeof(_var) }
  22
  23 const char *__ubus_strerror[__UBUS_STATUS_LAST] = {
  24         [UBUS_STATUS_OK] = "Success",
  25         [UBUS_STATUS_INVALID_COMMAND] = "Invalid command",
  26         [UBUS_STATUS_INVALID_ARGUMENT] = "Invalid argument",
  27         [UBUS_STATUS_METHOD_NOT_FOUND] = "Method not found",
  28         [UBUS_STATUS_NOT_FOUND] = "Not found",
  29         [UBUS_STATUS_NO_DATA] = "No response",
  30         [UBUS_STATUS_PERMISSION_DENIED] = "Permission denied",
  31 };
  32
  33 static struct blob_buf b;
  34
  35 static const struct blob_attr_info ubus_policy[UBUS_ATTR_MAX] = {
  36         [UBUS_ATTR_STATUS] = { .type = BLOB_ATTR_INT32 },
  37         [UBUS_ATTR_OBJID] = { .type = BLOB_ATTR_INT32 },
  38         [UBUS_ATTR_OBJPATH] = { .type = BLOB_ATTR_STRING },
  39         [UBUS_ATTR_METHOD] = { .type = BLOB_ATTR_STRING },
  40 };
  41 static struct blob_attr *attrbuf[UBUS_ATTR_MAX];
  42
  43 struct ubus_pending_data {
  44         struct list_head list;
  45         int type;
  46         struct blob_attr data[];
  47 };
  48
  49 static int ubus_cmp_id(const void *k1, const void *k2, void *ptr)
  50 {
  51         const uint32_t *id1 = k1, *id2 = k2;
  52
  53         if (*id1 < *id2)
  54                 return -1;
  55         else
  56                 return *id1 > *id2;
  57 }
  58
  59 static struct blob_attr **ubus_parse_msg(struct blob_attr *msg)
  60 {
  61         blob_parse(msg, attrbuf, ubus_policy, UBUS_ATTR_MAX);
  62         return attrbuf;
  63 }
  64
  65 const char *ubus_strerror(int error)
  66 {
  67         static char err[32];
  68
  69         if (error < 0 || error >= __UBUS_STATUS_LAST)
  70                 goto out;
  71
  72         if (!__ubus_strerror[error])
  73                 goto out;
  74
  75         return __ubus_strerror[error];
  76
  77 out:
  78         sprintf(err, "Unknown error: %d", error);
  79         return err;
  80 }
  81
  82 static int ubus_send_msg(struct ubus_context *ctx, uint32_t seq,
  83                          struct blob_attr *msg, int cmd, uint32_t peer)
  84 {
  85         struct ubus_msghdr hdr;
  86         struct iovec iov[2] = {
  87                 STATIC_IOV(hdr)
  88         };
  89
  90         hdr.version = 0;
  91         hdr.type = cmd;
  92         hdr.seq = seq;
  93         hdr.peer = peer;
  94
  95         if (!msg) {
  96                 blob_buf_init(&b, 0);
  97                 msg = b.head;
  98         }
  99
 100         iov[1].iov_base = (char *) msg;
 101         iov[1].iov_len = blob_raw_len(msg);
 102
 103         return writev(ctx->sock.fd, iov, 2);
 104 }
 105
 106 static int ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
 107                               struct blob_attr *msg, int cmd, uint32_t peer)
 108 {
 109         memset(req, 0, sizeof(*req));
 110
 111         INIT_LIST_HEAD(&req->list);
 112         INIT_LIST_HEAD(&req->pending);
 113         req->ctx = ctx;
 114         req->peer = peer;
 115         req->seq = ++ctx->request_seq;
 116         return ubus_send_msg(ctx, req->seq, msg, cmd, peer);
 117 }
 118
 119 static bool recv_retry(int fd, struct iovec *iov, bool wait)
 120 {
 121         int bytes;
 122
 123         while (iov->iov_len > 0) {
 124                 bytes = read(fd, iov->iov_base, iov->iov_len);
 125                 if (bytes < 0) {
 126                         bytes = 0;
 127                         if (errno == EINTR)
 128                                 continue;
 129
 130                         if (errno != EAGAIN) {
 131                                 perror("read");
 132                                 return false;
 133                         }
 134                 }
 135                 if (!wait && !bytes)
 136                         return false;
 137
 138                 wait = true;
 139                 iov->iov_len -= bytes;
 140                 iov->iov_base += bytes;
 141         }
 142
 143         return true;
 144 }
 145
 146 static bool ubus_validate_hdr(struct ubus_msghdr *hdr)
 147 {
 148         if (hdr->version != 0)
 149                 return false;
 150
 151         if (blob_raw_len(hdr->data) < sizeof(*hdr->data))
 152                 return false;
 153
 154         if (blob_raw_len(hdr->data) + sizeof(*hdr) > UBUS_MAX_MSGLEN)
 155                 return false;
 156
 157         return true;
 158 }
 159
 160 static bool get_next_msg(struct ubus_context *ctx, bool wait)
 161 {
 162         struct iovec iov = STATIC_IOV(ctx->msgbuf.hdr);
 163
 164         /* receive header + start attribute */
 165         iov.iov_len += sizeof(struct blob_attr);
 166         if (!recv_retry(ctx->sock.fd, &iov, wait))
 167                 return false;
 168
 169         iov.iov_len = blob_len(ctx->msgbuf.hdr.data);
 170         if (iov.iov_len > 0 && !recv_retry(ctx->sock.fd, &iov, true))
 171                 return false;
 172
 173         return ubus_validate_hdr(&ctx->msgbuf.hdr);
 174 }
 175
 176 static bool ubus_get_status(struct ubus_msghdr *hdr, int *ret)
 177 {
 178         ubus_parse_msg(hdr->data);
 179
 180         if (!attrbuf[UBUS_ATTR_STATUS])
 181                 return false;
 182
 183         *ret = blob_get_int32(attrbuf[UBUS_ATTR_STATUS]);
 184         return true;
 185 }
 186
 187 static void req_data_cb(struct ubus_request *req, int type, struct blob_attr *data)
 188 {
 189         struct blob_attr **attr;
 190
 191         if (req->raw_data_cb)
 192                 req->raw_data_cb(req, type, data);
 193
 194         if (!req->data_cb)
 195                 return;
 196
 197         attr = ubus_parse_msg(data);
 198         req->data_cb(req, type, attr[UBUS_ATTR_DATA]);
 199 }
 200
 201 static void ubus_process_req_data(struct ubus_request *req)
 202 {
 203         struct ubus_pending_data *data;
 204
 205         while (!list_empty(&req->pending)) {
 206                 data = list_first_entry(&req->pending,
 207                         struct ubus_pending_data, list);
 208                 list_del(&data->list);
 209                 if (!req->cancelled)
 210                         req_data_cb(req, data->type, data->data);
 211                 free(data);
 212         }
 213 }
 214
 215 static void ubus_req_complete_cb(struct ubus_request *req)
 216 {
 217         ubus_complete_handler_t cb = req->complete_cb;
 218
 219         if (!cb)
 220                 return;
 221
 222         req->complete_cb = NULL;
 223         cb(req, req->status_code);
 224 }
 225
 226 static int ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr *hdr)
 227 {
 228         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 229
 230         if (!list_empty(&req->list))
 231                 list_del(&req->list);
 232
 233         ubus_get_status(hdr, &ret);
 234         req->peer = hdr->peer;
 235         req->status_msg = true;
 236         req->status_code = ret;
 237         if (!req->blocked)
 238                 ubus_req_complete_cb(req);
 239
 240         return ret;
 241 }
 242
 243 static void ubus_req_data(struct ubus_request *req, struct ubus_msghdr *hdr)
 244 {
 245         struct ubus_pending_data *data;
 246         int len;
 247
 248         if (!req->blocked) {
 249                 req->blocked = true;
 250                 req_data_cb(req, hdr->type, hdr->data);
 251                 ubus_process_req_data(req);
 252                 req->blocked = false;
 253
 254                 if (req->status_msg)
 255                         ubus_req_complete_cb(req);
 256
 257                 return;
 258         }
 259
 260         len = blob_raw_len(hdr->data);
 261         data = calloc(1, sizeof(*data) + len);
 262         if (!data)
 263                 return;
 264
 265         data->type = hdr->type;
 266         memcpy(data->data, hdr->data, len);
 267         list_add(&data->list, &req->pending);
 268 }
 269
 270 static struct ubus_request *ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer)
 271 {
 272         struct ubus_request *req;
 273
 274         list_for_each_entry(req, &ctx->requests, list) {
 275                 if (seq != req->seq || peer != req->peer)
 276                         continue;
 277
 278                 return req;
 279         }
 280         return NULL;
 281 }
 282
 283 static void ubus_process_invoke(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 284 {
 285         struct ubus_request_data req;
 286         struct ubus_object *obj;
 287         uint32_t objid = 0;
 288         int method;
 289         int ret = 0;
 290
 291         ubus_parse_msg(hdr->data);
 292
 293         if (!attrbuf[UBUS_ATTR_OBJID])
 294                 return;
 295
 296         objid = blob_get_int32(attrbuf[UBUS_ATTR_OBJID]);
 297
 298         if (!attrbuf[UBUS_ATTR_METHOD]) {
 299                 ret = UBUS_STATUS_INVALID_ARGUMENT;
 300                 goto send;
 301         }
 302
 303         obj = avl_find_element(&ctx->objects, &objid, obj, avl);
 304         if (!obj) {
 305                 ret = UBUS_STATUS_NOT_FOUND;
 306                 goto send;
 307         }
 308
 309         for (method = 0; method < obj->n_methods; method++)
 310                 if (!strcmp(obj->methods[method].name,
 311                             blob_data(attrbuf[UBUS_ATTR_METHOD])))
 312                         goto found;
 313
 314         /* not found */
 315         ret = UBUS_STATUS_METHOD_NOT_FOUND;
 316         goto send;
 317
 318 found:
 319         req.object = objid;
 320         req.peer = hdr->peer;
 321         req.seq = hdr->seq;
 322         ret = obj->methods[method].handler(ctx, obj, &req,
 323                                            obj->methods[method].name,
 324                                            attrbuf[UBUS_ATTR_DATA]);
 325
 326 send:
 327         blob_buf_init(&b, 0);
 328         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 329         blob_put_int32(&b, UBUS_ATTR_OBJID, objid);
 330         ubus_send_msg(ctx, hdr->seq, b.head, UBUS_MSG_STATUS, hdr->peer);
 331 }
 332
 333 static void ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 334 {
 335         struct ubus_request *req;
 336
 337         switch(hdr->type) {
 338         case UBUS_MSG_STATUS:
 339                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 340                 if (!req)
 341                         break;
 342
 343                 ubus_process_req_status(req, hdr);
 344                 break;
 345
 346         case UBUS_MSG_DATA:
 347                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 348                 if (req && (req->data_cb || req->raw_data_cb))
 349                         ubus_req_data(req, hdr);
 350                 break;
 351
 352         case UBUS_MSG_INVOKE:
 353                 ubus_process_invoke(ctx, hdr);
 354                 break;
 355         default:
 356                 DPRINTF("unknown message type: %d\n", hdr->type);
 357                 break;
 358         }
 359 }
 360
 361 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
 362 {
 363         if (!list_empty(&req->list))
 364                 return;
 365
 366         req->cancelled = true;
 367         ubus_process_req_data(req);
 368         list_del(&req->list);
 369 }
 370
 371 void ubus_complete_request_async(struct ubus_context *ctx, struct ubus_request *req)
 372 {
 373         if (!list_empty(&req->list))
 374                 return;
 375
 376         list_add(&req->list, &ctx->requests);
 377 }
 378
 379 static void ubus_handle_data(struct uloop_fd *u, unsigned int events)
 380 {
 381         struct ubus_context *ctx = container_of(u, struct ubus_context, sock);
 382         struct ubus_msghdr *hdr = &ctx->msgbuf.hdr;
 383
 384         while (get_next_msg(ctx, false))
 385                 ubus_process_msg(ctx, hdr);
 386
 387         if (u->eof)
 388                 ctx->connection_lost(ctx);
 389 }
 390
 391 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req)
 392 {
 393         struct ubus_msghdr *hdr = &ctx->msgbuf.hdr;
 394
 395         if (!list_empty(&req->list))
 396                 list_del(&req->list);
 397
 398         while (1) {
 399                 if (req->status_msg)
 400                         return req->status_code;
 401
 402                 if (req->cancelled)
 403                         return UBUS_STATUS_NO_DATA;
 404
 405                 if (!get_next_msg(ctx, true))
 406                         return UBUS_STATUS_NO_DATA;
 407
 408                 if (hdr->seq != req->seq || hdr->peer != req->peer)
 409                         goto skip;
 410
 411                 switch(hdr->type) {
 412                 case UBUS_MSG_STATUS:
 413                         return ubus_process_req_status(req, hdr);
 414                 case UBUS_MSG_DATA:
 415                         if (req->data_cb || req->raw_data_cb)
 416                                 ubus_req_data(req, hdr);
 417                         continue;
 418                 default:
 419                         goto skip;
 420                 }
 421
 422 skip:
 423                 ubus_process_msg(ctx, hdr);
 424         }
 425 }
 426
 427 struct ubus_lookup_request {
 428         struct ubus_request req;
 429         ubus_lookup_handler_t cb;
 430 };
 431
 432 static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr *msg)
 433 {
 434         struct ubus_lookup_request *req;
 435         struct ubus_object_data obj;
 436         struct blob_attr **attr;
 437
 438         req = container_of(ureq, struct ubus_lookup_request, req);
 439         attr = ubus_parse_msg(msg);
 440
 441         if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_OBJPATH] ||
 442             !attr[UBUS_ATTR_OBJTYPE])
 443                 return;
 444
 445         memset(&obj, 0, sizeof(obj));
 446         obj.id = blob_get_int32(attr[UBUS_ATTR_OBJID]);
 447         obj.path = blob_data(attr[UBUS_ATTR_OBJPATH]);
 448         obj.type_id = blob_get_int32(attr[UBUS_ATTR_OBJTYPE]);
 449         obj.signature = attr[UBUS_ATTR_SIGNATURE];
 450         req->cb(ureq->ctx, &obj, ureq->priv);
 451 }
 452
 453 int ubus_lookup(struct ubus_context *ctx, const char *path,
 454                 ubus_lookup_handler_t cb, void *priv)
 455 {
 456         struct ubus_lookup_request lookup;
 457
 458         blob_buf_init(&b, 0);
 459         if (path)
 460                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 461         ubus_start_request(ctx, &lookup.req, b.head, UBUS_MSG_LOOKUP, 0);
 462         lookup.req.raw_data_cb = ubus_lookup_cb;
 463         lookup.req.priv = priv;
 464         lookup.cb = cb;
 465         return ubus_complete_request(ctx, &lookup.req);
 466 }
 467
 468 static void ubus_lookup_id_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 469 {
 470         struct blob_attr **attr;
 471         uint32_t *id = req->priv;
 472
 473         attr = ubus_parse_msg(msg);
 474
 475         if (!attr[UBUS_ATTR_OBJID])
 476                 return;
 477
 478         *id = blob_get_int32(attr[UBUS_ATTR_OBJID]);
 479 }
 480
 481 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id)
 482 {
 483         struct ubus_request req;
 484
 485         blob_buf_init(&b, 0);
 486         if (path)
 487                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 488         ubus_start_request(ctx, &req, b.head, UBUS_MSG_LOOKUP, 0);
 489         req.raw_data_cb = ubus_lookup_id_cb;
 490         req.priv = id;
 491
 492         return ubus_complete_request(ctx, &req);
 493 }
 494
 495 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 496                     struct blob_attr *msg)
 497 {
 498         int ret;
 499
 500         blob_buf_init(&b, 0);
 501         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 502         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 503         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer);
 504         if (ret < 0)
 505                 return UBUS_STATUS_NO_DATA;
 506
 507         return 0;
 508 }
 509
 510 void ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 511                        struct blob_attr *msg, struct ubus_request *req)
 512 {
 513         blob_buf_init(&b, 0);
 514         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 515         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 516         if (msg)
 517                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 518
 519         ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj);
 520 }
 521
 522 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 523                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv)
 524 {
 525         struct ubus_request req;
 526
 527         ubus_invoke_async(ctx, obj, method, msg, &req);
 528         req.data_cb = cb;
 529         req.priv = priv;
 530         return ubus_complete_request(ctx, &req);
 531 }
 532
 533 static void ubus_publish_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 534 {
 535         struct ubus_object *obj = req->priv;
 536
 537         ubus_parse_msg(msg);
 538
 539         if (!attrbuf[UBUS_ATTR_OBJID])
 540                 return;
 541
 542         obj->id = blob_get_int32(attrbuf[UBUS_ATTR_OBJID]);
 543
 544         if (attrbuf[UBUS_ATTR_OBJTYPE])
 545                 obj->type->id = blob_get_int32(attrbuf[UBUS_ATTR_OBJTYPE]);
 546
 547         obj->avl.key = &obj->id;
 548         avl_insert(&req->ctx->objects, &obj->avl);
 549 }
 550
 551 static bool ubus_push_table_data(const struct ubus_signature **sig, int *rem, bool array)
 552 {
 553         const struct ubus_signature *cur;
 554         bool nest_type;
 555         void *nest;
 556
 557         while (rem) {
 558                 cur = (*sig)++;
 559                 (*rem)--;
 560                 switch(cur->type) {
 561                 case UBUS_SIGNATURE_END:
 562                         return !array;
 563                 case BLOBMSG_TYPE_INT32:
 564                 case BLOBMSG_TYPE_STRING:
 565                         blobmsg_add_u32(&b, cur->name, cur->type);
 566                         break;
 567                 case BLOBMSG_TYPE_TABLE:
 568                 case BLOBMSG_TYPE_ARRAY:
 569                         nest_type = cur->type == BLOBMSG_TYPE_ARRAY;
 570                         nest = blobmsg_open_nested(&b, cur->name, nest_type);
 571                         if (!ubus_push_table_data(sig, rem, nest_type))
 572                                 return false;
 573                         blobmsg_close_table(&b, nest);
 574                         break;
 575                 default:
 576                         return false;
 577                 }
 578                 if (array)
 579                         return true;
 580         }
 581         return false;
 582 }
 583
 584 static bool ubus_push_object_type(struct ubus_object_type *type)
 585 {
 586         void *s, *m;
 587         int rem = type->n_signature;
 588         const struct ubus_signature *sig = type->signature;
 589
 590         s = blob_nest_start(&b, UBUS_ATTR_SIGNATURE);
 591         while (rem) {
 592                 if (sig->type != UBUS_SIGNATURE_METHOD)
 593                         return false;
 594
 595                 m = blobmsg_open_table(&b, sig->name);
 596
 597                 sig++;
 598                 rem--;
 599                 if (!ubus_push_table_data(&sig, &rem, false))
 600                         return false;
 601
 602                 blobmsg_close_table(&b, m);
 603         }
 604         blob_nest_end(&b, s);
 605
 606         return true;
 607 }
 608
 609 static int __ubus_publish(struct ubus_context *ctx, struct ubus_object *obj)
 610 {
 611         struct ubus_request req;
 612         int ret;
 613
 614         blob_buf_init(&b, 0);
 615
 616         if (obj->name && obj->type) {
 617                 blob_put_string(&b, UBUS_ATTR_OBJPATH, obj->name);
 618
 619                 if (obj->type->id)
 620                         blob_put_int32(&b, UBUS_ATTR_OBJTYPE, obj->type->id);
 621                 else if (!ubus_push_object_type(obj->type))
 622                         return UBUS_STATUS_INVALID_ARGUMENT;
 623         }
 624
 625         ubus_start_request(ctx, &req, b.head, UBUS_MSG_PUBLISH, 0);
 626         req.raw_data_cb = ubus_publish_cb;
 627         req.priv = obj;
 628         ret = ubus_complete_request(ctx, &req);
 629         if (ret)
 630                 return ret;
 631
 632         if (!obj->id)
 633                 return UBUS_STATUS_NO_DATA;
 634
 635         return 0;
 636 }
 637
 638 int ubus_publish(struct ubus_context *ctx, struct ubus_object *obj)
 639 {
 640         if (!obj->name || !obj->type)
 641                 return UBUS_STATUS_INVALID_ARGUMENT;
 642
 643         return __ubus_publish(ctx, obj);
 644 }
 645
 646 int ubus_register_event_handler(struct ubus_context *ctx, struct ubus_object *obj,
 647                                 const char *pattern)
 648 {
 649         struct blob_buf b2;
 650         int ret;
 651
 652         if (!obj->id) {
 653                 if (!!obj->name ^ !!obj->type)
 654                         return UBUS_STATUS_INVALID_ARGUMENT;
 655
 656                 ret = __ubus_publish(ctx, obj);
 657                 if (ret)
 658                         return ret;
 659         }
 660
 661         /* use a second buffer, ubus_invoke() overwrites the primary one */
 662         memset(&b2, 0, sizeof(b2));
 663         blob_buf_init(&b2, 0);
 664         blobmsg_add_u32(&b2, "object", obj->id);
 665         if (pattern)
 666                 blobmsg_add_string(&b2, "pattern", pattern);
 667
 668         ret = ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_EVENT, "register", b2.head,
 669                           NULL, NULL);
 670
 671         return 0;
 672 }
 673
 674
 675 void ubus_default_connection_lost(struct ubus_context *ctx)
 676 {
 677         if (ctx->sock.registered)
 678                 uloop_end();
 679 }
 680
 681 struct ubus_context *ubus_connect(const char *path)
 682 {
 683         struct ubus_context *ctx;
 684         struct {
 685                 struct ubus_msghdr hdr;
 686                 struct blob_attr data;
 687         } hdr;
 688         struct blob_attr *buf;
 689
 690         if (!path)
 691                 path = UBUS_UNIX_SOCKET;
 692
 693         ctx = calloc(1, sizeof(*ctx));
 694         if (!ctx)
 695                 goto error;
 696
 697         ctx->sock.fd = usock(USOCK_UNIX, path, NULL);
 698         if (ctx->sock.fd < 0)
 699                 goto error_free;
 700
 701         ctx->sock.cb = ubus_handle_data;
 702
 703         if (read(ctx->sock.fd, &hdr, sizeof(hdr)) != sizeof(hdr))
 704                 goto error_close;
 705
 706         if (!ubus_validate_hdr(&hdr.hdr))
 707                 goto error_close;
 708
 709         if (hdr.hdr.type != UBUS_MSG_HELLO)
 710                 goto error_close;
 711
 712         buf = calloc(1, blob_raw_len(&hdr.data));
 713         if (!buf)
 714                 goto error_close;
 715
 716         memcpy(buf, &hdr.data, sizeof(hdr.data));
 717         if (read(ctx->sock.fd, blob_data(buf), blob_len(buf)) != blob_len(buf))
 718                 goto error_free_buf;
 719
 720         ctx->local_id = hdr.hdr.peer;
 721         free(buf);
 722
 723         ctx->connection_lost = ubus_default_connection_lost;
 724
 725         INIT_LIST_HEAD(&ctx->requests);
 726         avl_init(&ctx->objects, ubus_cmp_id, false, NULL);
 727
 728         if (!ctx->local_id)
 729                 goto error_close;
 730
 731         return ctx;
 732
 733 error_free_buf:
 734         free(buf);
 735 error_close:
 736         close(ctx->sock.fd);
 737 error_free:
 738         free(ctx);
 739 error:
 740         return NULL;
 741 }
 742
 743 void ubus_free(struct ubus_context *ctx)
 744 {
 745         close(ctx->sock.fd);
 746         free(ctx);
 747 }