libubus.c

   1 #include <sys/types.h>
   2 #include <sys/uio.h>
   3 #include <sys/socket.h>
   4 #include <fcntl.h>
   5 #include <unistd.h>
   6
   7 #include <libubox/blob.h>
   8 #include <libubox/blobmsg.h>
   9 #include <libubox/usock.h>
  10
  11 #include "libubus.h"
  12 #include "ubusmsg.h"
  13
  14 #define STATIC_IOV(_var) { .iov_base = (char *) &(_var), .iov_len = sizeof(_var) }
  15
  16 const char *__ubus_strerror[__UBUS_STATUS_LAST] = {
  17         [UBUS_STATUS_OK] = "Success",
  18         [UBUS_STATUS_INVALID_COMMAND] = "Invalid command",
  19         [UBUS_STATUS_INVALID_ARGUMENT] = "Invalid argument",
  20         [UBUS_STATUS_METHOD_NOT_FOUND] = "Method not found",
  21         [UBUS_STATUS_NOT_FOUND] = "Not found",
  22         [UBUS_STATUS_NO_DATA] = "No response",
  23         [UBUS_STATUS_PERMISSION_DENIED] = "Permission denied",
  24         [UBUS_STATUS_TIMEOUT] = "Request timed out",
  25 };
  26
  27 static struct blob_buf b;
  28
  29 static const struct blob_attr_info ubus_policy[UBUS_ATTR_MAX] = {
  30         [UBUS_ATTR_STATUS] = { .type = BLOB_ATTR_INT32 },
  31         [UBUS_ATTR_OBJID] = { .type = BLOB_ATTR_INT32 },
  32         [UBUS_ATTR_OBJPATH] = { .type = BLOB_ATTR_STRING },
  33         [UBUS_ATTR_METHOD] = { .type = BLOB_ATTR_STRING },
  34 };
  35 static struct blob_attr *attrbuf[UBUS_ATTR_MAX];
  36
  37 struct ubus_pending_data {
  38         struct list_head list;
  39         int type;
  40         struct blob_attr data[];
  41 };
  42
  43 static int ubus_cmp_id(const void *k1, const void *k2, void *ptr)
  44 {
  45         const uint32_t *id1 = k1, *id2 = k2;
  46
  47         if (*id1 < *id2)
  48                 return -1;
  49         else
  50                 return *id1 > *id2;
  51 }
  52
  53 static struct blob_attr **ubus_parse_msg(struct blob_attr *msg)
  54 {
  55         blob_parse(msg, attrbuf, ubus_policy, UBUS_ATTR_MAX);
  56         return attrbuf;
  57 }
  58
  59 const char *ubus_strerror(int error)
  60 {
  61         static char err[32];
  62
  63         if (error < 0 || error >= __UBUS_STATUS_LAST)
  64                 goto out;
  65
  66         if (!__ubus_strerror[error])
  67                 goto out;
  68
  69         return __ubus_strerror[error];
  70
  71 out:
  72         sprintf(err, "Unknown error: %d", error);
  73         return err;
  74 }
  75
  76 static int writev_retry(int fd, struct iovec *iov, int iov_len)
  77 {
  78         int len = 0;
  79
  80         do {
  81                 int cur_len = writev(fd, iov, iov_len);
  82                 if (cur_len < 0) {
  83                         switch(errno) {
  84                         case EAGAIN:
  85                                 /* turn off non-blocking mode */
  86                                 fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) &
  87                                       ~O_NONBLOCK);
  88                                 break;
  89                         case EINTR:
  90                                 break;
  91                         default:
  92                                 return -1;
  93                         }
  94                         continue;
  95                 }
  96                 len += cur_len;
  97                 while (cur_len >= iov->iov_len) {
  98                         cur_len -= iov->iov_len;
  99                         iov_len--;
 100                         iov++;
 101                         if (!cur_len || !iov_len)
 102                                 return len;
 103                 }
 104                 iov->iov_len -= cur_len;
 105         } while (1);
 106 }
 107
 108 static int ubus_send_msg(struct ubus_context *ctx, uint32_t seq,
 109                          struct blob_attr *msg, int cmd, uint32_t peer)
 110 {
 111         struct ubus_msghdr hdr;
 112         struct iovec iov[2] = {
 113                 STATIC_IOV(hdr)
 114         };
 115
 116         hdr.version = 0;
 117         hdr.type = cmd;
 118         hdr.seq = seq;
 119         hdr.peer = peer;
 120
 121         if (!msg) {
 122                 blob_buf_init(&b, 0);
 123                 msg = b.head;
 124         }
 125
 126         iov[1].iov_base = (char *) msg;
 127         iov[1].iov_len = blob_raw_len(msg);
 128
 129         return writev_retry(ctx->sock.fd, iov, ARRAY_SIZE(iov));
 130 }
 131
 132 static int ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
 133                               struct blob_attr *msg, int cmd, uint32_t peer)
 134 {
 135         memset(req, 0, sizeof(*req));
 136
 137         if (msg && blob_pad_len(msg) > UBUS_MAX_MSGLEN)
 138                 return -1;
 139
 140         INIT_LIST_HEAD(&req->list);
 141         INIT_LIST_HEAD(&req->pending);
 142         req->ctx = ctx;
 143         req->peer = peer;
 144         req->seq = ++ctx->request_seq;
 145         return ubus_send_msg(ctx, req->seq, msg, cmd, peer);
 146 }
 147
 148 static bool recv_retry(int fd, struct iovec *iov, bool wait)
 149 {
 150         int bytes;
 151
 152         while (iov->iov_len > 0) {
 153                 bytes = read(fd, iov->iov_base, iov->iov_len);
 154                 if (bytes < 0) {
 155                         bytes = 0;
 156                         if (uloop_cancelled)
 157                                 return false;
 158                         if (errno == EINTR)
 159                                 continue;
 160
 161                         if (errno != EAGAIN)
 162                                 return false;
 163                 }
 164                 if (!wait && !bytes)
 165                         return false;
 166
 167                 wait = true;
 168                 iov->iov_len -= bytes;
 169                 iov->iov_base += bytes;
 170         }
 171
 172         return true;
 173 }
 174
 175 static bool ubus_validate_hdr(struct ubus_msghdr *hdr)
 176 {
 177         if (hdr->version != 0)
 178                 return false;
 179
 180         if (blob_raw_len(hdr->data) < sizeof(*hdr->data))
 181                 return false;
 182
 183         if (blob_pad_len(hdr->data) > UBUS_MAX_MSGLEN)
 184                 return false;
 185
 186         return true;
 187 }
 188
 189 static bool get_next_msg(struct ubus_context *ctx)
 190 {
 191         struct iovec iov = STATIC_IOV(ctx->msgbuf.hdr);
 192
 193         /* receive header + start attribute */
 194         iov.iov_len += sizeof(struct blob_attr);
 195         if (!recv_retry(ctx->sock.fd, &iov, false))
 196                 return false;
 197
 198         iov.iov_len = blob_len(ctx->msgbuf.hdr.data);
 199         if (iov.iov_len > 0 && !recv_retry(ctx->sock.fd, &iov, true))
 200                 return false;
 201
 202         return ubus_validate_hdr(&ctx->msgbuf.hdr);
 203 }
 204
 205 static bool ubus_get_status(struct ubus_msghdr *hdr, int *ret)
 206 {
 207         ubus_parse_msg(hdr->data);
 208
 209         if (!attrbuf[UBUS_ATTR_STATUS])
 210                 return false;
 211
 212         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 213         return true;
 214 }
 215
 216 static void req_data_cb(struct ubus_request *req, int type, struct blob_attr *data)
 217 {
 218         struct blob_attr **attr;
 219
 220         if (req->raw_data_cb)
 221                 req->raw_data_cb(req, type, data);
 222
 223         if (!req->data_cb)
 224                 return;
 225
 226         attr = ubus_parse_msg(data);
 227         req->data_cb(req, type, attr[UBUS_ATTR_DATA]);
 228 }
 229
 230 static void ubus_process_req_data(struct ubus_request *req)
 231 {
 232         struct ubus_pending_data *data;
 233
 234         while (!list_empty(&req->pending)) {
 235                 data = list_first_entry(&req->pending,
 236                         struct ubus_pending_data, list);
 237                 list_del(&data->list);
 238                 if (!req->cancelled)
 239                         req_data_cb(req, data->type, data->data);
 240                 free(data);
 241         }
 242 }
 243
 244 static void ubus_req_complete_cb(struct ubus_request *req)
 245 {
 246         ubus_complete_handler_t cb = req->complete_cb;
 247
 248         if (!cb)
 249                 return;
 250
 251         req->complete_cb = NULL;
 252         cb(req, req->status_code);
 253 }
 254
 255 static int ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr *hdr)
 256 {
 257         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 258
 259         if (!list_empty(&req->list))
 260                 list_del(&req->list);
 261
 262         ubus_get_status(hdr, &ret);
 263         req->peer = hdr->peer;
 264         req->status_msg = true;
 265         req->status_code = ret;
 266         if (!req->blocked)
 267                 ubus_req_complete_cb(req);
 268
 269         return ret;
 270 }
 271
 272 static void ubus_req_data(struct ubus_request *req, struct ubus_msghdr *hdr)
 273 {
 274         struct ubus_pending_data *data;
 275         int len;
 276
 277         if (!req->blocked) {
 278                 req->blocked = true;
 279                 req_data_cb(req, hdr->type, hdr->data);
 280                 ubus_process_req_data(req);
 281                 req->blocked = false;
 282
 283                 if (req->status_msg)
 284                         ubus_req_complete_cb(req);
 285
 286                 return;
 287         }
 288
 289         len = blob_raw_len(hdr->data);
 290         data = calloc(1, sizeof(*data) + len);
 291         if (!data)
 292                 return;
 293
 294         data->type = hdr->type;
 295         memcpy(data->data, hdr->data, len);
 296         list_add(&data->list, &req->pending);
 297 }
 298
 299 static struct ubus_request *ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer)
 300 {
 301         struct ubus_request *req;
 302
 303         list_for_each_entry(req, &ctx->requests, list) {
 304                 if (seq != req->seq || peer != req->peer)
 305                         continue;
 306
 307                 return req;
 308         }
 309         return NULL;
 310 }
 311
 312 static void ubus_process_invoke(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 313 {
 314         struct ubus_request_data req;
 315         struct ubus_object *obj;
 316         uint32_t objid = 0;
 317         int method;
 318         int ret = 0;
 319
 320         ubus_parse_msg(hdr->data);
 321
 322         if (!attrbuf[UBUS_ATTR_OBJID])
 323                 return;
 324
 325         objid = blob_get_u32(attrbuf[UBUS_ATTR_OBJID]);
 326
 327         if (!attrbuf[UBUS_ATTR_METHOD]) {
 328                 ret = UBUS_STATUS_INVALID_ARGUMENT;
 329                 goto send;
 330         }
 331
 332         obj = avl_find_element(&ctx->objects, &objid, obj, avl);
 333         if (!obj) {
 334                 ret = UBUS_STATUS_NOT_FOUND;
 335                 goto send;
 336         }
 337
 338         for (method = 0; method < obj->n_methods; method++)
 339                 if (!obj->methods[method].name ||
 340                     !strcmp(obj->methods[method].name,
 341                             blob_data(attrbuf[UBUS_ATTR_METHOD])))
 342                         goto found;
 343
 344         /* not found */
 345         ret = UBUS_STATUS_METHOD_NOT_FOUND;
 346         goto send;
 347
 348 found:
 349         req.object = objid;
 350         req.peer = hdr->peer;
 351         req.seq = hdr->seq;
 352         ret = obj->methods[method].handler(ctx, obj, &req,
 353                                            blob_data(attrbuf[UBUS_ATTR_METHOD]),
 354                                            attrbuf[UBUS_ATTR_DATA]);
 355
 356 send:
 357         blob_buf_init(&b, 0);
 358         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 359         blob_put_int32(&b, UBUS_ATTR_OBJID, objid);
 360         ubus_send_msg(ctx, hdr->seq, b.head, UBUS_MSG_STATUS, hdr->peer);
 361 }
 362
 363 static void ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 364 {
 365         struct ubus_request *req;
 366
 367         switch(hdr->type) {
 368         case UBUS_MSG_STATUS:
 369                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 370                 if (!req)
 371                         break;
 372
 373                 ubus_process_req_status(req, hdr);
 374                 break;
 375
 376         case UBUS_MSG_DATA:
 377                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 378                 if (req && (req->data_cb || req->raw_data_cb))
 379                         ubus_req_data(req, hdr);
 380                 break;
 381
 382         case UBUS_MSG_INVOKE:
 383                 ubus_process_invoke(ctx, hdr);
 384                 break;
 385         }
 386 }
 387
 388 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
 389 {
 390         if (!list_empty(&req->list))
 391                 return;
 392
 393         req->cancelled = true;
 394         ubus_process_req_data(req);
 395         list_del(&req->list);
 396 }
 397
 398 void ubus_complete_request_async(struct ubus_context *ctx, struct ubus_request *req)
 399 {
 400         if (!list_empty(&req->list))
 401                 return;
 402
 403         list_add(&req->list, &ctx->requests);
 404 }
 405
 406 static void ubus_handle_data(struct uloop_fd *u, unsigned int events)
 407 {
 408         struct ubus_context *ctx = container_of(u, struct ubus_context, sock);
 409         struct ubus_msghdr *hdr = &ctx->msgbuf.hdr;
 410
 411         while (get_next_msg(ctx)) {
 412                 ubus_process_msg(ctx, hdr);
 413                 if (uloop_cancelled)
 414                         break;
 415         }
 416
 417         if (u->eof)
 418                 ctx->connection_lost(ctx);
 419 }
 420
 421 static void ubus_sync_req_cb(struct ubus_request *req, int ret)
 422 {
 423         req->status_msg = true;
 424         req->status_code = ret;
 425         uloop_end();
 426 }
 427
 428 struct ubus_sync_req_cb {
 429         struct uloop_timeout timeout;
 430         struct ubus_request *req;
 431 };
 432
 433 static void ubus_sync_req_timeout_cb(struct uloop_timeout *timeout)
 434 {
 435         struct ubus_sync_req_cb *cb;
 436
 437         cb = container_of(timeout, struct ubus_sync_req_cb, timeout);
 438         ubus_sync_req_cb(cb->req, UBUS_STATUS_TIMEOUT);
 439 }
 440
 441 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 442                           int timeout)
 443 {
 444         struct ubus_sync_req_cb cb;
 445         ubus_complete_handler_t complete_cb = req->complete_cb;
 446         bool registered = ctx->sock.registered;
 447         bool cancelled = uloop_cancelled;
 448         int status = UBUS_STATUS_NO_DATA;
 449
 450         if (!registered) {
 451                 uloop_init();
 452                 ubus_add_uloop(ctx);
 453         }
 454
 455         if (timeout) {
 456                 memset(&cb, 0, sizeof(cb));
 457                 cb.req = req;
 458                 cb.timeout.cb = ubus_sync_req_timeout_cb;
 459                 uloop_timeout_set(&cb.timeout, timeout);
 460         }
 461
 462         ubus_complete_request_async(ctx, req);
 463         req->complete_cb = ubus_sync_req_cb;
 464
 465         uloop_run();
 466
 467         if (timeout)
 468                 uloop_timeout_cancel(&cb.timeout);
 469
 470         if (req->status_msg)
 471                 status = req->status_code;
 472
 473         req->complete_cb = complete_cb;
 474         if (req->complete_cb)
 475                 req->complete_cb(req, status);
 476
 477         uloop_cancelled = cancelled;
 478         if (!registered)
 479                 uloop_fd_delete(&ctx->sock);
 480
 481         return status;
 482 }
 483
 484 struct ubus_lookup_request {
 485         struct ubus_request req;
 486         ubus_lookup_handler_t cb;
 487 };
 488
 489 static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr *msg)
 490 {
 491         struct ubus_lookup_request *req;
 492         struct ubus_object_data obj;
 493         struct blob_attr **attr;
 494
 495         req = container_of(ureq, struct ubus_lookup_request, req);
 496         attr = ubus_parse_msg(msg);
 497
 498         if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_OBJPATH] ||
 499             !attr[UBUS_ATTR_OBJTYPE])
 500                 return;
 501
 502         memset(&obj, 0, sizeof(obj));
 503         obj.id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 504         obj.path = blob_data(attr[UBUS_ATTR_OBJPATH]);
 505         obj.type_id = blob_get_u32(attr[UBUS_ATTR_OBJTYPE]);
 506         obj.signature = attr[UBUS_ATTR_SIGNATURE];
 507         req->cb(ureq->ctx, &obj, ureq->priv);
 508 }
 509
 510 int ubus_lookup(struct ubus_context *ctx, const char *path,
 511                 ubus_lookup_handler_t cb, void *priv)
 512 {
 513         struct ubus_lookup_request lookup;
 514
 515         blob_buf_init(&b, 0);
 516         if (path)
 517                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 518
 519         if (ubus_start_request(ctx, &lookup.req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 520                 return UBUS_STATUS_INVALID_ARGUMENT;
 521
 522         lookup.req.raw_data_cb = ubus_lookup_cb;
 523         lookup.req.priv = priv;
 524         lookup.cb = cb;
 525         return ubus_complete_request(ctx, &lookup.req, 0);
 526 }
 527
 528 static void ubus_lookup_id_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 529 {
 530         struct blob_attr **attr;
 531         uint32_t *id = req->priv;
 532
 533         attr = ubus_parse_msg(msg);
 534
 535         if (!attr[UBUS_ATTR_OBJID])
 536                 return;
 537
 538         *id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 539 }
 540
 541 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id)
 542 {
 543         struct ubus_request req;
 544
 545         blob_buf_init(&b, 0);
 546         if (path)
 547                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 548
 549         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 550                 return UBUS_STATUS_INVALID_ARGUMENT;
 551
 552         req.raw_data_cb = ubus_lookup_id_cb;
 553         req.priv = id;
 554
 555         return ubus_complete_request(ctx, &req, 0);
 556 }
 557
 558 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 559                     struct blob_attr *msg)
 560 {
 561         int ret;
 562
 563         blob_buf_init(&b, 0);
 564         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 565         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 566         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer);
 567         if (ret < 0)
 568                 return UBUS_STATUS_NO_DATA;
 569
 570         return 0;
 571 }
 572
 573 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 574                        struct blob_attr *msg, struct ubus_request *req)
 575 {
 576         blob_buf_init(&b, 0);
 577         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 578         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 579         if (msg)
 580                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 581
 582         if (ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 583                 return UBUS_STATUS_INVALID_ARGUMENT;
 584
 585         return 0;
 586 }
 587
 588 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 589                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 590                 int timeout)
 591 {
 592         struct ubus_request req;
 593
 594         ubus_invoke_async(ctx, obj, method, msg, &req);
 595         req.data_cb = cb;
 596         req.priv = priv;
 597         return ubus_complete_request(ctx, &req, timeout);
 598 }
 599
 600 static void ubus_add_object_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 601 {
 602         struct ubus_object *obj = req->priv;
 603
 604         ubus_parse_msg(msg);
 605
 606         if (!attrbuf[UBUS_ATTR_OBJID])
 607                 return;
 608
 609         obj->id = blob_get_u32(attrbuf[UBUS_ATTR_OBJID]);
 610
 611         if (attrbuf[UBUS_ATTR_OBJTYPE])
 612                 obj->type->id = blob_get_u32(attrbuf[UBUS_ATTR_OBJTYPE]);
 613
 614         obj->avl.key = &obj->id;
 615         avl_insert(&req->ctx->objects, &obj->avl);
 616 }
 617
 618 static bool ubus_push_table_data(const struct ubus_signature **sig, int *rem, bool array)
 619 {
 620         const struct ubus_signature *cur;
 621         bool nest_type;
 622         void *nest;
 623
 624         while (rem) {
 625                 cur = (*sig)++;
 626                 (*rem)--;
 627                 switch(cur->type) {
 628                 case UBUS_SIGNATURE_END:
 629                         return !array;
 630                 case BLOBMSG_TYPE_INT32:
 631                 case BLOBMSG_TYPE_STRING:
 632                         blobmsg_add_u32(&b, cur->name, cur->type);
 633                         break;
 634                 case BLOBMSG_TYPE_TABLE:
 635                 case BLOBMSG_TYPE_ARRAY:
 636                         nest_type = cur->type == BLOBMSG_TYPE_ARRAY;
 637                         nest = blobmsg_open_nested(&b, cur->name, nest_type);
 638                         if (!ubus_push_table_data(sig, rem, nest_type))
 639                                 return false;
 640                         blobmsg_close_table(&b, nest);
 641                         break;
 642                 default:
 643                         return false;
 644                 }
 645                 if (array)
 646                         return true;
 647         }
 648         return false;
 649 }
 650
 651 static bool ubus_push_object_type(struct ubus_object_type *type)
 652 {
 653         void *s, *m;
 654         int rem = type->n_signature;
 655         const struct ubus_signature *sig = type->signature;
 656
 657         s = blob_nest_start(&b, UBUS_ATTR_SIGNATURE);
 658         while (rem) {
 659                 if (sig->type != UBUS_SIGNATURE_METHOD)
 660                         return false;
 661
 662                 m = blobmsg_open_table(&b, sig->name);
 663
 664                 sig++;
 665                 rem--;
 666                 if (!ubus_push_table_data(&sig, &rem, false))
 667                         return false;
 668
 669                 blobmsg_close_table(&b, m);
 670         }
 671         blob_nest_end(&b, s);
 672
 673         return true;
 674 }
 675
 676 static int __ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj)
 677 {
 678         struct ubus_request req;
 679         int ret;
 680
 681         blob_buf_init(&b, 0);
 682
 683         if (obj->name && obj->type) {
 684                 blob_put_string(&b, UBUS_ATTR_OBJPATH, obj->name);
 685
 686                 if (obj->type->id)
 687                         blob_put_int32(&b, UBUS_ATTR_OBJTYPE, obj->type->id);
 688                 else if (!ubus_push_object_type(obj->type))
 689                         return UBUS_STATUS_INVALID_ARGUMENT;
 690         }
 691
 692         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_ADD_OBJECT, 0) < 0)
 693                 return UBUS_STATUS_INVALID_ARGUMENT;
 694
 695         req.raw_data_cb = ubus_add_object_cb;
 696         req.priv = obj;
 697         ret = ubus_complete_request(ctx, &req, 0);
 698         if (ret)
 699                 return ret;
 700
 701         if (!obj->id)
 702                 return UBUS_STATUS_NO_DATA;
 703
 704         return 0;
 705 }
 706
 707 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj)
 708 {
 709         if (!obj->name || !obj->type)
 710                 return UBUS_STATUS_INVALID_ARGUMENT;
 711
 712         return __ubus_add_object(ctx, obj);
 713 }
 714
 715 static void ubus_remove_object_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 716 {
 717         struct ubus_object *obj = req->priv;
 718
 719         ubus_parse_msg(msg);
 720
 721         if (!attrbuf[UBUS_ATTR_OBJID])
 722                 return;
 723
 724         obj->id = 0;
 725
 726         if (attrbuf[UBUS_ATTR_OBJTYPE] && obj->type)
 727                 obj->type->id = 0;
 728
 729         avl_delete(&req->ctx->objects, &obj->avl);
 730 }
 731
 732 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj)
 733 {
 734         struct ubus_request req;
 735         int ret;
 736
 737         blob_buf_init(&b, 0);
 738         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 739
 740         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_REMOVE_OBJECT, 0) < 0)
 741                 return UBUS_STATUS_INVALID_ARGUMENT;
 742
 743         req.raw_data_cb = ubus_remove_object_cb;
 744         req.priv = obj;
 745         ret = ubus_complete_request(ctx, &req, 0);
 746         if (ret)
 747                 return ret;
 748
 749         if (obj->id)
 750                 return UBUS_STATUS_NO_DATA;
 751
 752         return 0;
 753 }
 754
 755 static int ubus_event_cb(struct ubus_context *ctx, struct ubus_object *obj,
 756                          struct ubus_request_data *req,
 757                          const char *method, struct blob_attr *msg)
 758 {
 759         struct ubus_event_handler *ev;
 760
 761         ev = container_of(obj, struct ubus_event_handler, obj);
 762         ev->cb(ctx, ev, method, msg);
 763         return 0;
 764 }
 765
 766 static const struct ubus_method event_method = {
 767         .name = NULL,
 768         .handler = ubus_event_cb,
 769 };
 770
 771 int ubus_register_event_handler(struct ubus_context *ctx,
 772                                 struct ubus_event_handler *ev,
 773                                 const char *pattern)
 774 {
 775         struct ubus_object *obj = &ev->obj;
 776         struct blob_buf b2;
 777         int ret;
 778
 779         if (!obj->id) {
 780                 obj->methods = &event_method;
 781                 obj->n_methods = 1;
 782
 783                 if (!!obj->name ^ !!obj->type)
 784                         return UBUS_STATUS_INVALID_ARGUMENT;
 785
 786                 ret = __ubus_add_object(ctx, obj);
 787                 if (ret)
 788                         return ret;
 789         }
 790
 791         /* use a second buffer, ubus_invoke() overwrites the primary one */
 792         memset(&b2, 0, sizeof(b2));
 793         blob_buf_init(&b2, 0);
 794         blobmsg_add_u32(&b2, "object", obj->id);
 795         if (pattern)
 796                 blobmsg_add_string(&b2, "pattern", pattern);
 797
 798         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_EVENT, "register", b2.head,
 799                           NULL, NULL, 0);
 800 }
 801
 802 int ubus_send_event(struct ubus_context *ctx, const char *id,
 803                     struct blob_attr *data)
 804 {
 805         struct ubus_request req;
 806         void *s;
 807
 808         blob_buf_init(&b, 0);
 809         blob_put_int32(&b, UBUS_ATTR_OBJID, UBUS_SYSTEM_OBJECT_EVENT);
 810         blob_put_string(&b, UBUS_ATTR_METHOD, "send");
 811         s = blob_nest_start(&b, UBUS_ATTR_DATA);
 812         blobmsg_add_string(&b, "id", id);
 813         blobmsg_add_field(&b, BLOBMSG_TYPE_TABLE, "data", blob_data(data), blob_len(data));
 814         blob_nest_end(&b, s);
 815
 816         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_INVOKE, UBUS_SYSTEM_OBJECT_EVENT) < 0)
 817                 return UBUS_STATUS_INVALID_ARGUMENT;
 818
 819         return ubus_complete_request(ctx, &req, 0);
 820 }
 821
 822 static void ubus_default_connection_lost(struct ubus_context *ctx)
 823 {
 824         if (ctx->sock.registered)
 825                 uloop_end();
 826 }
 827
 828 struct ubus_context *ubus_connect(const char *path)
 829 {
 830         struct ubus_context *ctx;
 831         struct {
 832                 struct ubus_msghdr hdr;
 833                 struct blob_attr data;
 834         } hdr;
 835         struct blob_attr *buf;
 836
 837         if (!path)
 838                 path = UBUS_UNIX_SOCKET;
 839
 840         ctx = calloc(1, sizeof(*ctx));
 841         if (!ctx)
 842                 goto error;
 843
 844         ctx->sock.fd = usock(USOCK_UNIX, path, NULL);
 845         if (ctx->sock.fd < 0)
 846                 goto error_free;
 847
 848         ctx->sock.cb = ubus_handle_data;
 849
 850         if (read(ctx->sock.fd, &hdr, sizeof(hdr)) != sizeof(hdr))
 851                 goto error_close;
 852
 853         if (!ubus_validate_hdr(&hdr.hdr))
 854                 goto error_close;
 855
 856         if (hdr.hdr.type != UBUS_MSG_HELLO)
 857                 goto error_close;
 858
 859         buf = calloc(1, blob_raw_len(&hdr.data));
 860         if (!buf)
 861                 goto error_close;
 862
 863         memcpy(buf, &hdr.data, sizeof(hdr.data));
 864         if (read(ctx->sock.fd, blob_data(buf), blob_len(buf)) != blob_len(buf))
 865                 goto error_free_buf;
 866
 867         ctx->local_id = hdr.hdr.peer;
 868         free(buf);
 869
 870         ctx->connection_lost = ubus_default_connection_lost;
 871
 872         INIT_LIST_HEAD(&ctx->requests);
 873         avl_init(&ctx->objects, ubus_cmp_id, false, NULL);
 874
 875         if (!ctx->local_id)
 876                 goto error_close;
 877
 878         return ctx;
 879
 880 error_free_buf:
 881         free(buf);
 882 error_close:
 883         close(ctx->sock.fd);
 884 error_free:
 885         free(ctx);
 886 error:
 887         return NULL;
 888 }
 889
 890 void ubus_free(struct ubus_context *ctx)
 891 {
 892         close(ctx->sock.fd);
 893         free(ctx);
 894 }