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 (!obj->methods[method].name ||
 311                     !strcmp(obj->methods[method].name,
 312                             blob_data(attrbuf[UBUS_ATTR_METHOD])))
 313                         goto found;
 314
 315         /* not found */
 316         ret = UBUS_STATUS_METHOD_NOT_FOUND;
 317         goto send;
 318
 319 found:
 320         req.object = objid;
 321         req.peer = hdr->peer;
 322         req.seq = hdr->seq;
 323         ret = obj->methods[method].handler(ctx, obj, &req,
 324                                            obj->methods[method].name,
 325                                            attrbuf[UBUS_ATTR_DATA]);
 326
 327 send:
 328         blob_buf_init(&b, 0);
 329         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 330         blob_put_int32(&b, UBUS_ATTR_OBJID, objid);
 331         ubus_send_msg(ctx, hdr->seq, b.head, UBUS_MSG_STATUS, hdr->peer);
 332 }
 333
 334 static void ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 335 {
 336         struct ubus_request *req;
 337
 338         switch(hdr->type) {
 339         case UBUS_MSG_STATUS:
 340                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 341                 if (!req)
 342                         break;
 343
 344                 ubus_process_req_status(req, hdr);
 345                 break;
 346
 347         case UBUS_MSG_DATA:
 348                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 349                 if (req && (req->data_cb || req->raw_data_cb))
 350                         ubus_req_data(req, hdr);
 351                 break;
 352
 353         case UBUS_MSG_INVOKE:
 354                 ubus_process_invoke(ctx, hdr);
 355                 break;
 356         default:
 357                 DPRINTF("unknown message type: %d\n", hdr->type);
 358                 break;
 359         }
 360 }
 361
 362 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
 363 {
 364         if (!list_empty(&req->list))
 365                 return;
 366
 367         req->cancelled = true;
 368         ubus_process_req_data(req);
 369         list_del(&req->list);
 370 }
 371
 372 void ubus_complete_request_async(struct ubus_context *ctx, struct ubus_request *req)
 373 {
 374         if (!list_empty(&req->list))
 375                 return;
 376
 377         list_add(&req->list, &ctx->requests);
 378 }
 379
 380 static void ubus_handle_data(struct uloop_fd *u, unsigned int events)
 381 {
 382         struct ubus_context *ctx = container_of(u, struct ubus_context, sock);
 383         struct ubus_msghdr *hdr = &ctx->msgbuf.hdr;
 384
 385         while (get_next_msg(ctx, false))
 386                 ubus_process_msg(ctx, hdr);
 387
 388         if (u->eof)
 389                 ctx->connection_lost(ctx);
 390 }
 391
 392 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req)
 393 {
 394         struct ubus_msghdr *hdr = &ctx->msgbuf.hdr;
 395
 396         if (!list_empty(&req->list))
 397                 list_del(&req->list);
 398
 399         while (1) {
 400                 if (req->status_msg)
 401                         return req->status_code;
 402
 403                 if (req->cancelled)
 404                         return UBUS_STATUS_NO_DATA;
 405
 406                 if (!get_next_msg(ctx, true))
 407                         return UBUS_STATUS_NO_DATA;
 408
 409                 if (hdr->seq != req->seq || hdr->peer != req->peer)
 410                         goto skip;
 411
 412                 switch(hdr->type) {
 413                 case UBUS_MSG_STATUS:
 414                         return ubus_process_req_status(req, hdr);
 415                 case UBUS_MSG_DATA:
 416                         if (req->data_cb || req->raw_data_cb)
 417                                 ubus_req_data(req, hdr);
 418                         continue;
 419                 default:
 420                         goto skip;
 421                 }
 422
 423 skip:
 424                 ubus_process_msg(ctx, hdr);
 425         }
 426 }
 427
 428 struct ubus_lookup_request {
 429         struct ubus_request req;
 430         ubus_lookup_handler_t cb;
 431 };
 432
 433 static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr *msg)
 434 {
 435         struct ubus_lookup_request *req;
 436         struct ubus_object_data obj;
 437         struct blob_attr **attr;
 438
 439         req = container_of(ureq, struct ubus_lookup_request, req);
 440         attr = ubus_parse_msg(msg);
 441
 442         if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_OBJPATH] ||
 443             !attr[UBUS_ATTR_OBJTYPE])
 444                 return;
 445
 446         memset(&obj, 0, sizeof(obj));
 447         obj.id = blob_get_int32(attr[UBUS_ATTR_OBJID]);
 448         obj.path = blob_data(attr[UBUS_ATTR_OBJPATH]);
 449         obj.type_id = blob_get_int32(attr[UBUS_ATTR_OBJTYPE]);
 450         obj.signature = attr[UBUS_ATTR_SIGNATURE];
 451         req->cb(ureq->ctx, &obj, ureq->priv);
 452 }
 453
 454 int ubus_lookup(struct ubus_context *ctx, const char *path,
 455                 ubus_lookup_handler_t cb, void *priv)
 456 {
 457         struct ubus_lookup_request lookup;
 458
 459         blob_buf_init(&b, 0);
 460         if (path)
 461                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 462         ubus_start_request(ctx, &lookup.req, b.head, UBUS_MSG_LOOKUP, 0);
 463         lookup.req.raw_data_cb = ubus_lookup_cb;
 464         lookup.req.priv = priv;
 465         lookup.cb = cb;
 466         return ubus_complete_request(ctx, &lookup.req);
 467 }
 468
 469 static void ubus_lookup_id_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 470 {
 471         struct blob_attr **attr;
 472         uint32_t *id = req->priv;
 473
 474         attr = ubus_parse_msg(msg);
 475
 476         if (!attr[UBUS_ATTR_OBJID])
 477                 return;
 478
 479         *id = blob_get_int32(attr[UBUS_ATTR_OBJID]);
 480 }
 481
 482 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id)
 483 {
 484         struct ubus_request req;
 485
 486         blob_buf_init(&b, 0);
 487         if (path)
 488                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 489         ubus_start_request(ctx, &req, b.head, UBUS_MSG_LOOKUP, 0);
 490         req.raw_data_cb = ubus_lookup_id_cb;
 491         req.priv = id;
 492
 493         return ubus_complete_request(ctx, &req);
 494 }
 495
 496 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 497                     struct blob_attr *msg)
 498 {
 499         int ret;
 500
 501         blob_buf_init(&b, 0);
 502         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 503         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 504         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer);
 505         if (ret < 0)
 506                 return UBUS_STATUS_NO_DATA;
 507
 508         return 0;
 509 }
 510
 511 void ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 512                        struct blob_attr *msg, struct ubus_request *req)
 513 {
 514         blob_buf_init(&b, 0);
 515         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 516         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 517         if (msg)
 518                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 519
 520         ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj);
 521 }
 522
 523 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 524                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv)
 525 {
 526         struct ubus_request req;
 527
 528         ubus_invoke_async(ctx, obj, method, msg, &req);
 529         req.data_cb = cb;
 530         req.priv = priv;
 531         return ubus_complete_request(ctx, &req);
 532 }
 533
 534 static void ubus_publish_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 535 {
 536         struct ubus_object *obj = req->priv;
 537
 538         ubus_parse_msg(msg);
 539
 540         if (!attrbuf[UBUS_ATTR_OBJID])
 541                 return;
 542
 543         obj->id = blob_get_int32(attrbuf[UBUS_ATTR_OBJID]);
 544
 545         if (attrbuf[UBUS_ATTR_OBJTYPE])
 546                 obj->type->id = blob_get_int32(attrbuf[UBUS_ATTR_OBJTYPE]);
 547
 548         obj->avl.key = &obj->id;
 549         avl_insert(&req->ctx->objects, &obj->avl);
 550 }
 551
 552 static bool ubus_push_table_data(const struct ubus_signature **sig, int *rem, bool array)
 553 {
 554         const struct ubus_signature *cur;
 555         bool nest_type;
 556         void *nest;
 557
 558         while (rem) {
 559                 cur = (*sig)++;
 560                 (*rem)--;
 561                 switch(cur->type) {
 562                 case UBUS_SIGNATURE_END:
 563                         return !array;
 564                 case BLOBMSG_TYPE_INT32:
 565                 case BLOBMSG_TYPE_STRING:
 566                         blobmsg_add_u32(&b, cur->name, cur->type);
 567                         break;
 568                 case BLOBMSG_TYPE_TABLE:
 569                 case BLOBMSG_TYPE_ARRAY:
 570                         nest_type = cur->type == BLOBMSG_TYPE_ARRAY;
 571                         nest = blobmsg_open_nested(&b, cur->name, nest_type);
 572                         if (!ubus_push_table_data(sig, rem, nest_type))
 573                                 return false;
 574                         blobmsg_close_table(&b, nest);
 575                         break;
 576                 default:
 577                         return false;
 578                 }
 579                 if (array)
 580                         return true;
 581         }
 582         return false;
 583 }
 584
 585 static bool ubus_push_object_type(struct ubus_object_type *type)
 586 {
 587         void *s, *m;
 588         int rem = type->n_signature;
 589         const struct ubus_signature *sig = type->signature;
 590
 591         s = blob_nest_start(&b, UBUS_ATTR_SIGNATURE);
 592         while (rem) {
 593                 if (sig->type != UBUS_SIGNATURE_METHOD)
 594                         return false;
 595
 596                 m = blobmsg_open_table(&b, sig->name);
 597
 598                 sig++;
 599                 rem--;
 600                 if (!ubus_push_table_data(&sig, &rem, false))
 601                         return false;
 602
 603                 blobmsg_close_table(&b, m);
 604         }
 605         blob_nest_end(&b, s);
 606
 607         return true;
 608 }
 609
 610 static int __ubus_publish(struct ubus_context *ctx, struct ubus_object *obj)
 611 {
 612         struct ubus_request req;
 613         int ret;
 614
 615         blob_buf_init(&b, 0);
 616
 617         if (obj->name && obj->type) {
 618                 blob_put_string(&b, UBUS_ATTR_OBJPATH, obj->name);
 619
 620                 if (obj->type->id)
 621                         blob_put_int32(&b, UBUS_ATTR_OBJTYPE, obj->type->id);
 622                 else if (!ubus_push_object_type(obj->type))
 623                         return UBUS_STATUS_INVALID_ARGUMENT;
 624         }
 625
 626         ubus_start_request(ctx, &req, b.head, UBUS_MSG_PUBLISH, 0);
 627         req.raw_data_cb = ubus_publish_cb;
 628         req.priv = obj;
 629         ret = ubus_complete_request(ctx, &req);
 630         if (ret)
 631                 return ret;
 632
 633         if (!obj->id)
 634                 return UBUS_STATUS_NO_DATA;
 635
 636         return 0;
 637 }
 638
 639 int ubus_publish(struct ubus_context *ctx, struct ubus_object *obj)
 640 {
 641         if (!obj->name || !obj->type)
 642                 return UBUS_STATUS_INVALID_ARGUMENT;
 643
 644         return __ubus_publish(ctx, obj);
 645 }
 646
 647 static int ubus_event_cb(struct ubus_context *ctx, struct ubus_object *obj,
 648                          struct ubus_request_data *req,
 649                          const char *method, struct blob_attr *msg)
 650 {
 651         struct ubus_event_handler *ev;
 652
 653         ev = container_of(obj, struct ubus_event_handler, obj);
 654         ev->cb(ctx, ev, method, msg);
 655         return 0;
 656 }
 657
 658 static const struct ubus_method event_method = {
 659         .name = NULL,
 660         .handler = ubus_event_cb,
 661 };
 662
 663 int ubus_register_event_handler(struct ubus_context *ctx,
 664                                 struct ubus_event_handler *ev,
 665                                 const char *pattern)
 666 {
 667         struct ubus_object *obj = &ev->obj;
 668         struct blob_buf b2;
 669         int ret;
 670
 671         if (!obj->id) {
 672                 obj->methods = &event_method;
 673                 obj->n_methods = 1;
 674
 675                 if (!!obj->name ^ !!obj->type)
 676                         return UBUS_STATUS_INVALID_ARGUMENT;
 677
 678                 ret = __ubus_publish(ctx, obj);
 679                 if (ret)
 680                         return ret;
 681         }
 682
 683         /* use a second buffer, ubus_invoke() overwrites the primary one */
 684         memset(&b2, 0, sizeof(b2));
 685         blob_buf_init(&b2, 0);
 686         blobmsg_add_u32(&b2, "object", obj->id);
 687         if (pattern)
 688                 blobmsg_add_string(&b2, "pattern", pattern);
 689
 690         ret = ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_EVENT, "register", b2.head,
 691                           NULL, NULL);
 692
 693         return 0;
 694 }
 695
 696
 697 void ubus_default_connection_lost(struct ubus_context *ctx)
 698 {
 699         if (ctx->sock.registered)
 700                 uloop_end();
 701 }
 702
 703 struct ubus_context *ubus_connect(const char *path)
 704 {
 705         struct ubus_context *ctx;
 706         struct {
 707                 struct ubus_msghdr hdr;
 708                 struct blob_attr data;
 709         } hdr;
 710         struct blob_attr *buf;
 711
 712         if (!path)
 713                 path = UBUS_UNIX_SOCKET;
 714
 715         ctx = calloc(1, sizeof(*ctx));
 716         if (!ctx)
 717                 goto error;
 718
 719         ctx->sock.fd = usock(USOCK_UNIX, path, NULL);
 720         if (ctx->sock.fd < 0)
 721                 goto error_free;
 722
 723         ctx->sock.cb = ubus_handle_data;
 724
 725         if (read(ctx->sock.fd, &hdr, sizeof(hdr)) != sizeof(hdr))
 726                 goto error_close;
 727
 728         if (!ubus_validate_hdr(&hdr.hdr))
 729                 goto error_close;
 730
 731         if (hdr.hdr.type != UBUS_MSG_HELLO)
 732                 goto error_close;
 733
 734         buf = calloc(1, blob_raw_len(&hdr.data));
 735         if (!buf)
 736                 goto error_close;
 737
 738         memcpy(buf, &hdr.data, sizeof(hdr.data));
 739         if (read(ctx->sock.fd, blob_data(buf), blob_len(buf)) != blob_len(buf))
 740                 goto error_free_buf;
 741
 742         ctx->local_id = hdr.hdr.peer;
 743         free(buf);
 744
 745         ctx->connection_lost = ubus_default_connection_lost;
 746
 747         INIT_LIST_HEAD(&ctx->requests);
 748         avl_init(&ctx->objects, ubus_cmp_id, false, NULL);
 749
 750         if (!ctx->local_id)
 751                 goto error_close;
 752
 753         return ctx;
 754
 755 error_free_buf:
 756         free(buf);
 757 error_close:
 758         close(ctx->sock.fd);
 759 error_free:
 760         free(ctx);
 761 error:
 762         return NULL;
 763 }
 764
 765 void ubus_free(struct ubus_context *ctx)
 766 {
 767         close(ctx->sock.fd);
 768         free(ctx);
 769 }