libubus.c

   1 /*
   2  * Copyright (C) 2011 Felix Fietkau <nbd@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU Lesser General Public License version 2.1
   6  * as published by the Free Software Foundation
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <sys/types.h>
  15 #include <sys/uio.h>
  16 #include <sys/socket.h>
  17 #include <fcntl.h>
  18 #include <unistd.h>
  19 #include <poll.h>
  20
  21 #include <libubox/blob.h>
  22 #include <libubox/blobmsg.h>
  23 #include <libubox/usock.h>
  24
  25 #include "libubus.h"
  26 #include "ubusmsg.h"
  27
  28 #define STATIC_IOV(_var) { .iov_base = (char *) &(_var), .iov_len = sizeof(_var) }
  29
  30 const char *__ubus_strerror[__UBUS_STATUS_LAST] = {
  31         [UBUS_STATUS_OK] = "Success",
  32         [UBUS_STATUS_INVALID_COMMAND] = "Invalid command",
  33         [UBUS_STATUS_INVALID_ARGUMENT] = "Invalid argument",
  34         [UBUS_STATUS_METHOD_NOT_FOUND] = "Method not found",
  35         [UBUS_STATUS_NOT_FOUND] = "Not found",
  36         [UBUS_STATUS_NO_DATA] = "No response",
  37         [UBUS_STATUS_PERMISSION_DENIED] = "Permission denied",
  38         [UBUS_STATUS_TIMEOUT] = "Request timed out",
  39         [UBUS_STATUS_NOT_SUPPORTED] = "Operation not supported",
  40         [UBUS_STATUS_UNKNOWN_ERROR] = "Unknown error",
  41 };
  42
  43 static struct blob_buf b;
  44
  45 static const struct blob_attr_info ubus_policy[UBUS_ATTR_MAX] = {
  46         [UBUS_ATTR_STATUS] = { .type = BLOB_ATTR_INT32 },
  47         [UBUS_ATTR_OBJID] = { .type = BLOB_ATTR_INT32 },
  48         [UBUS_ATTR_OBJPATH] = { .type = BLOB_ATTR_STRING },
  49         [UBUS_ATTR_METHOD] = { .type = BLOB_ATTR_STRING },
  50 };
  51 static struct blob_attr *attrbuf[UBUS_ATTR_MAX];
  52
  53 struct ubus_pending_data {
  54         struct list_head list;
  55         int type;
  56         struct blob_attr data[];
  57 };
  58
  59 static int ubus_cmp_id(const void *k1, const void *k2, void *ptr)
  60 {
  61         const uint32_t *id1 = k1, *id2 = k2;
  62
  63         if (*id1 < *id2)
  64                 return -1;
  65         else
  66                 return *id1 > *id2;
  67 }
  68
  69 static struct blob_attr **ubus_parse_msg(struct blob_attr *msg)
  70 {
  71         blob_parse(msg, attrbuf, ubus_policy, UBUS_ATTR_MAX);
  72         return attrbuf;
  73 }
  74
  75 const char *ubus_strerror(int error)
  76 {
  77         static char err[32];
  78
  79         if (error < 0 || error >= __UBUS_STATUS_LAST)
  80                 goto out;
  81
  82         if (!__ubus_strerror[error])
  83                 goto out;
  84
  85         return __ubus_strerror[error];
  86
  87 out:
  88         sprintf(err, "Unknown error: %d", error);
  89         return err;
  90 }
  91
  92 static void wait_data(int fd, bool write)
  93 {
  94         struct pollfd pfd = { .fd = fd };
  95
  96         pfd.events = write ? POLLOUT : POLLIN;
  97         poll(&pfd, 1, 0);
  98 }
  99
 100 static int writev_retry(int fd, struct iovec *iov, int iov_len)
 101 {
 102         int len = 0;
 103
 104         do {
 105                 int cur_len = writev(fd, iov, iov_len);
 106                 if (cur_len < 0) {
 107                         switch(errno) {
 108                         case EAGAIN:
 109                                 wait_data(fd, true);
 110                                 break;
 111                         case EINTR:
 112                                 break;
 113                         default:
 114                                 return -1;
 115                         }
 116                         continue;
 117                 }
 118                 len += cur_len;
 119                 while (cur_len >= iov->iov_len) {
 120                         cur_len -= iov->iov_len;
 121                         iov_len--;
 122                         iov++;
 123                         if (!cur_len || !iov_len)
 124                                 return len;
 125                 }
 126                 iov->iov_len -= cur_len;
 127         } while (1);
 128 }
 129
 130 static int ubus_send_msg(struct ubus_context *ctx, uint32_t seq,
 131                          struct blob_attr *msg, int cmd, uint32_t peer)
 132 {
 133         struct ubus_msghdr hdr;
 134         struct iovec iov[2] = {
 135                 STATIC_IOV(hdr)
 136         };
 137
 138         hdr.version = 0;
 139         hdr.type = cmd;
 140         hdr.seq = seq;
 141         hdr.peer = peer;
 142
 143         if (!msg) {
 144                 blob_buf_init(&b, 0);
 145                 msg = b.head;
 146         }
 147
 148         iov[1].iov_base = (char *) msg;
 149         iov[1].iov_len = blob_raw_len(msg);
 150
 151         return writev_retry(ctx->sock.fd, iov, ARRAY_SIZE(iov));
 152 }
 153
 154 static int ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
 155                               struct blob_attr *msg, int cmd, uint32_t peer)
 156 {
 157         memset(req, 0, sizeof(*req));
 158
 159         if (msg && blob_pad_len(msg) > UBUS_MAX_MSGLEN)
 160                 return -1;
 161
 162         INIT_LIST_HEAD(&req->list);
 163         INIT_LIST_HEAD(&req->pending);
 164         req->ctx = ctx;
 165         req->peer = peer;
 166         req->seq = ++ctx->request_seq;
 167         return ubus_send_msg(ctx, req->seq, msg, cmd, peer);
 168 }
 169
 170 static bool recv_retry(int fd, struct iovec *iov, bool wait)
 171 {
 172         int bytes;
 173
 174         while (iov->iov_len > 0) {
 175                 if (wait)
 176                         wait_data(fd, false);
 177
 178                 bytes = read(fd, iov->iov_base, iov->iov_len);
 179                 if (bytes < 0) {
 180                         bytes = 0;
 181                         if (uloop_cancelled)
 182                                 return false;
 183                         if (errno == EINTR)
 184                                 continue;
 185
 186                         if (errno != EAGAIN)
 187                                 return false;
 188                 }
 189                 if (!wait && !bytes)
 190                         return false;
 191
 192                 wait = true;
 193                 iov->iov_len -= bytes;
 194                 iov->iov_base += bytes;
 195         }
 196
 197         return true;
 198 }
 199
 200 static bool ubus_validate_hdr(struct ubus_msghdr *hdr)
 201 {
 202         if (hdr->version != 0)
 203                 return false;
 204
 205         if (blob_raw_len(hdr->data) < sizeof(*hdr->data))
 206                 return false;
 207
 208         if (blob_pad_len(hdr->data) > UBUS_MAX_MSGLEN)
 209                 return false;
 210
 211         return true;
 212 }
 213
 214 static bool get_next_msg(struct ubus_context *ctx)
 215 {
 216         struct iovec iov = STATIC_IOV(ctx->msgbuf.hdr);
 217
 218         /* receive header + start attribute */
 219         iov.iov_len += sizeof(struct blob_attr);
 220         if (!recv_retry(ctx->sock.fd, &iov, false))
 221                 return false;
 222
 223         iov.iov_len = blob_len(ctx->msgbuf.hdr.data);
 224         if (iov.iov_len > 0 && !recv_retry(ctx->sock.fd, &iov, true))
 225                 return false;
 226
 227         return ubus_validate_hdr(&ctx->msgbuf.hdr);
 228 }
 229
 230 static bool ubus_get_status(struct ubus_msghdr *hdr, int *ret)
 231 {
 232         ubus_parse_msg(hdr->data);
 233
 234         if (!attrbuf[UBUS_ATTR_STATUS])
 235                 return false;
 236
 237         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 238         return true;
 239 }
 240
 241 static void req_data_cb(struct ubus_request *req, int type, struct blob_attr *data)
 242 {
 243         struct blob_attr **attr;
 244
 245         if (req->raw_data_cb)
 246                 req->raw_data_cb(req, type, data);
 247
 248         if (!req->data_cb)
 249                 return;
 250
 251         attr = ubus_parse_msg(data);
 252         req->data_cb(req, type, attr[UBUS_ATTR_DATA]);
 253 }
 254
 255 static void ubus_process_req_data(struct ubus_request *req)
 256 {
 257         struct ubus_pending_data *data;
 258
 259         while (!list_empty(&req->pending)) {
 260                 data = list_first_entry(&req->pending,
 261                         struct ubus_pending_data, list);
 262                 list_del(&data->list);
 263                 if (!req->cancelled)
 264                         req_data_cb(req, data->type, data->data);
 265                 free(data);
 266         }
 267 }
 268
 269 static void ubus_req_complete_cb(struct ubus_request *req)
 270 {
 271         ubus_complete_handler_t cb = req->complete_cb;
 272
 273         if (!cb)
 274                 return;
 275
 276         req->complete_cb = NULL;
 277         cb(req, req->status_code);
 278 }
 279
 280 static int ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr *hdr)
 281 {
 282         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 283
 284         if (!list_empty(&req->list))
 285                 list_del(&req->list);
 286
 287         ubus_get_status(hdr, &ret);
 288         req->peer = hdr->peer;
 289         req->status_msg = true;
 290         req->status_code = ret;
 291         if (!req->blocked)
 292                 ubus_req_complete_cb(req);
 293
 294         return ret;
 295 }
 296
 297 static void ubus_req_data(struct ubus_request *req, struct ubus_msghdr *hdr)
 298 {
 299         struct ubus_pending_data *data;
 300         int len;
 301
 302         if (!req->blocked) {
 303                 req->blocked = true;
 304                 req_data_cb(req, hdr->type, hdr->data);
 305                 ubus_process_req_data(req);
 306                 req->blocked = false;
 307
 308                 if (req->status_msg)
 309                         ubus_req_complete_cb(req);
 310
 311                 return;
 312         }
 313
 314         len = blob_raw_len(hdr->data);
 315         data = calloc(1, sizeof(*data) + len);
 316         if (!data)
 317                 return;
 318
 319         data->type = hdr->type;
 320         memcpy(data->data, hdr->data, len);
 321         list_add(&data->list, &req->pending);
 322 }
 323
 324 static struct ubus_request *ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer)
 325 {
 326         struct ubus_request *req;
 327
 328         list_for_each_entry(req, &ctx->requests, list) {
 329                 if (seq != req->seq || peer != req->peer)
 330                         continue;
 331
 332                 return req;
 333         }
 334         return NULL;
 335 }
 336
 337 static void ubus_process_invoke(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 338 {
 339         struct ubus_request_data req;
 340         struct ubus_object *obj;
 341         uint32_t objid = 0;
 342         int method;
 343         int ret = 0;
 344
 345         ubus_parse_msg(hdr->data);
 346
 347         if (!attrbuf[UBUS_ATTR_OBJID])
 348                 return;
 349
 350         objid = blob_get_u32(attrbuf[UBUS_ATTR_OBJID]);
 351
 352         if (!attrbuf[UBUS_ATTR_METHOD]) {
 353                 ret = UBUS_STATUS_INVALID_ARGUMENT;
 354                 goto send;
 355         }
 356
 357         obj = avl_find_element(&ctx->objects, &objid, obj, avl);
 358         if (!obj) {
 359                 ret = UBUS_STATUS_NOT_FOUND;
 360                 goto send;
 361         }
 362
 363         for (method = 0; method < obj->n_methods; method++)
 364                 if (!obj->methods[method].name ||
 365                     !strcmp(obj->methods[method].name,
 366                             blob_data(attrbuf[UBUS_ATTR_METHOD])))
 367                         goto found;
 368
 369         /* not found */
 370         ret = UBUS_STATUS_METHOD_NOT_FOUND;
 371         goto send;
 372
 373 found:
 374         req.object = objid;
 375         req.peer = hdr->peer;
 376         req.seq = hdr->seq;
 377         ret = obj->methods[method].handler(ctx, obj, &req,
 378                                            blob_data(attrbuf[UBUS_ATTR_METHOD]),
 379                                            attrbuf[UBUS_ATTR_DATA]);
 380
 381 send:
 382         blob_buf_init(&b, 0);
 383         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 384         blob_put_int32(&b, UBUS_ATTR_OBJID, objid);
 385         ubus_send_msg(ctx, hdr->seq, b.head, UBUS_MSG_STATUS, hdr->peer);
 386 }
 387
 388 static void ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 389 {
 390         struct ubus_request *req;
 391
 392         switch(hdr->type) {
 393         case UBUS_MSG_STATUS:
 394                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 395                 if (!req)
 396                         break;
 397
 398                 ubus_process_req_status(req, hdr);
 399                 break;
 400
 401         case UBUS_MSG_DATA:
 402                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 403                 if (req && (req->data_cb || req->raw_data_cb))
 404                         ubus_req_data(req, hdr);
 405                 break;
 406
 407         case UBUS_MSG_INVOKE:
 408                 ubus_process_invoke(ctx, hdr);
 409                 break;
 410         }
 411 }
 412
 413 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
 414 {
 415         if (!list_empty(&req->list))
 416                 return;
 417
 418         req->cancelled = true;
 419         ubus_process_req_data(req);
 420         list_del(&req->list);
 421 }
 422
 423 void ubus_complete_request_async(struct ubus_context *ctx, struct ubus_request *req)
 424 {
 425         if (!list_empty(&req->list))
 426                 return;
 427
 428         list_add(&req->list, &ctx->requests);
 429 }
 430
 431 static void ubus_handle_data(struct uloop_fd *u, unsigned int events)
 432 {
 433         struct ubus_context *ctx = container_of(u, struct ubus_context, sock);
 434         struct ubus_msghdr *hdr = &ctx->msgbuf.hdr;
 435
 436         while (get_next_msg(ctx)) {
 437                 ubus_process_msg(ctx, hdr);
 438                 if (uloop_cancelled)
 439                         break;
 440         }
 441
 442         if (u->eof)
 443                 ctx->connection_lost(ctx);
 444 }
 445
 446 static void ubus_sync_req_cb(struct ubus_request *req, int ret)
 447 {
 448         req->status_msg = true;
 449         req->status_code = ret;
 450         uloop_end();
 451 }
 452
 453 struct ubus_sync_req_cb {
 454         struct uloop_timeout timeout;
 455         struct ubus_request *req;
 456 };
 457
 458 static void ubus_sync_req_timeout_cb(struct uloop_timeout *timeout)
 459 {
 460         struct ubus_sync_req_cb *cb;
 461
 462         cb = container_of(timeout, struct ubus_sync_req_cb, timeout);
 463         ubus_sync_req_cb(cb->req, UBUS_STATUS_TIMEOUT);
 464 }
 465
 466 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 467                           int timeout)
 468 {
 469         struct ubus_sync_req_cb cb;
 470         ubus_complete_handler_t complete_cb = req->complete_cb;
 471         bool registered = ctx->sock.registered;
 472         bool cancelled = uloop_cancelled;
 473         int status = UBUS_STATUS_NO_DATA;
 474
 475         if (!registered) {
 476                 uloop_init();
 477                 ubus_add_uloop(ctx);
 478         }
 479
 480         if (timeout) {
 481                 memset(&cb, 0, sizeof(cb));
 482                 cb.req = req;
 483                 cb.timeout.cb = ubus_sync_req_timeout_cb;
 484                 uloop_timeout_set(&cb.timeout, timeout);
 485         }
 486
 487         ubus_complete_request_async(ctx, req);
 488         req->complete_cb = ubus_sync_req_cb;
 489
 490         uloop_run();
 491
 492         if (timeout)
 493                 uloop_timeout_cancel(&cb.timeout);
 494
 495         if (req->status_msg)
 496                 status = req->status_code;
 497
 498         req->complete_cb = complete_cb;
 499         if (req->complete_cb)
 500                 req->complete_cb(req, status);
 501
 502         uloop_cancelled = cancelled;
 503         if (!registered)
 504                 uloop_fd_delete(&ctx->sock);
 505
 506         return status;
 507 }
 508
 509 struct ubus_lookup_request {
 510         struct ubus_request req;
 511         ubus_lookup_handler_t cb;
 512 };
 513
 514 static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr *msg)
 515 {
 516         struct ubus_lookup_request *req;
 517         struct ubus_object_data obj;
 518         struct blob_attr **attr;
 519
 520         req = container_of(ureq, struct ubus_lookup_request, req);
 521         attr = ubus_parse_msg(msg);
 522
 523         if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_OBJPATH] ||
 524             !attr[UBUS_ATTR_OBJTYPE])
 525                 return;
 526
 527         memset(&obj, 0, sizeof(obj));
 528         obj.id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 529         obj.path = blob_data(attr[UBUS_ATTR_OBJPATH]);
 530         obj.type_id = blob_get_u32(attr[UBUS_ATTR_OBJTYPE]);
 531         obj.signature = attr[UBUS_ATTR_SIGNATURE];
 532         req->cb(ureq->ctx, &obj, ureq->priv);
 533 }
 534
 535 int ubus_lookup(struct ubus_context *ctx, const char *path,
 536                 ubus_lookup_handler_t cb, void *priv)
 537 {
 538         struct ubus_lookup_request lookup;
 539
 540         blob_buf_init(&b, 0);
 541         if (path)
 542                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 543
 544         if (ubus_start_request(ctx, &lookup.req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 545                 return UBUS_STATUS_INVALID_ARGUMENT;
 546
 547         lookup.req.raw_data_cb = ubus_lookup_cb;
 548         lookup.req.priv = priv;
 549         lookup.cb = cb;
 550         return ubus_complete_request(ctx, &lookup.req, 0);
 551 }
 552
 553 static void ubus_lookup_id_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 554 {
 555         struct blob_attr **attr;
 556         uint32_t *id = req->priv;
 557
 558         attr = ubus_parse_msg(msg);
 559
 560         if (!attr[UBUS_ATTR_OBJID])
 561                 return;
 562
 563         *id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 564 }
 565
 566 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id)
 567 {
 568         struct ubus_request req;
 569
 570         blob_buf_init(&b, 0);
 571         if (path)
 572                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 573
 574         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 575                 return UBUS_STATUS_INVALID_ARGUMENT;
 576
 577         req.raw_data_cb = ubus_lookup_id_cb;
 578         req.priv = id;
 579
 580         return ubus_complete_request(ctx, &req, 0);
 581 }
 582
 583 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 584                     struct blob_attr *msg)
 585 {
 586         int ret;
 587
 588         blob_buf_init(&b, 0);
 589         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 590         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 591         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer);
 592         if (ret < 0)
 593                 return UBUS_STATUS_NO_DATA;
 594
 595         return 0;
 596 }
 597
 598 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 599                        struct blob_attr *msg, struct ubus_request *req)
 600 {
 601         blob_buf_init(&b, 0);
 602         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 603         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 604         if (msg)
 605                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 606
 607         if (ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 608                 return UBUS_STATUS_INVALID_ARGUMENT;
 609
 610         return 0;
 611 }
 612
 613 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 614                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 615                 int timeout)
 616 {
 617         struct ubus_request req;
 618
 619         ubus_invoke_async(ctx, obj, method, msg, &req);
 620         req.data_cb = cb;
 621         req.priv = priv;
 622         return ubus_complete_request(ctx, &req, timeout);
 623 }
 624
 625 static void ubus_add_object_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 626 {
 627         struct ubus_object *obj = req->priv;
 628
 629         ubus_parse_msg(msg);
 630
 631         if (!attrbuf[UBUS_ATTR_OBJID])
 632                 return;
 633
 634         obj->id = blob_get_u32(attrbuf[UBUS_ATTR_OBJID]);
 635
 636         if (attrbuf[UBUS_ATTR_OBJTYPE])
 637                 obj->type->id = blob_get_u32(attrbuf[UBUS_ATTR_OBJTYPE]);
 638
 639         obj->avl.key = &obj->id;
 640         avl_insert(&req->ctx->objects, &obj->avl);
 641 }
 642
 643 static void ubus_push_method_data(const struct ubus_method *m)
 644 {
 645         void *mtbl;
 646         int i;
 647
 648         mtbl = blobmsg_open_table(&b, m->name);
 649
 650         for (i = 0; i < m->n_policy; i++)
 651                 blobmsg_add_u32(&b, m->policy[i].name, m->policy[i].type);
 652
 653         blobmsg_close_table(&b, mtbl);
 654 }
 655
 656 static bool ubus_push_object_type(const struct ubus_object_type *type)
 657 {
 658         void *s;
 659         int i;
 660
 661         s = blob_nest_start(&b, UBUS_ATTR_SIGNATURE);
 662
 663         for (i = 0; i < type->n_methods; i++)
 664                 ubus_push_method_data(&type->methods[i]);
 665
 666         blob_nest_end(&b, s);
 667
 668         return true;
 669 }
 670
 671 static int __ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj)
 672 {
 673         struct ubus_request req;
 674         int ret;
 675
 676         blob_buf_init(&b, 0);
 677
 678         if (obj->name && obj->type) {
 679                 blob_put_string(&b, UBUS_ATTR_OBJPATH, obj->name);
 680
 681                 if (obj->type->id)
 682                         blob_put_int32(&b, UBUS_ATTR_OBJTYPE, obj->type->id);
 683                 else if (!ubus_push_object_type(obj->type))
 684                         return UBUS_STATUS_INVALID_ARGUMENT;
 685         }
 686
 687         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_ADD_OBJECT, 0) < 0)
 688                 return UBUS_STATUS_INVALID_ARGUMENT;
 689
 690         req.raw_data_cb = ubus_add_object_cb;
 691         req.priv = obj;
 692         ret = ubus_complete_request(ctx, &req, 0);
 693         if (ret)
 694                 return ret;
 695
 696         if (!obj->id)
 697                 return UBUS_STATUS_NO_DATA;
 698
 699         return 0;
 700 }
 701
 702 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj)
 703 {
 704         if (!obj->name || !obj->type)
 705                 return UBUS_STATUS_INVALID_ARGUMENT;
 706
 707         return __ubus_add_object(ctx, obj);
 708 }
 709
 710 static void ubus_remove_object_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 711 {
 712         struct ubus_object *obj = req->priv;
 713
 714         ubus_parse_msg(msg);
 715
 716         if (!attrbuf[UBUS_ATTR_OBJID])
 717                 return;
 718
 719         obj->id = 0;
 720
 721         if (attrbuf[UBUS_ATTR_OBJTYPE] && obj->type)
 722                 obj->type->id = 0;
 723
 724         avl_delete(&req->ctx->objects, &obj->avl);
 725 }
 726
 727 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj)
 728 {
 729         struct ubus_request req;
 730         int ret;
 731
 732         blob_buf_init(&b, 0);
 733         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 734
 735         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_REMOVE_OBJECT, 0) < 0)
 736                 return UBUS_STATUS_INVALID_ARGUMENT;
 737
 738         req.raw_data_cb = ubus_remove_object_cb;
 739         req.priv = obj;
 740         ret = ubus_complete_request(ctx, &req, 0);
 741         if (ret)
 742                 return ret;
 743
 744         if (obj->id)
 745                 return UBUS_STATUS_NO_DATA;
 746
 747         return 0;
 748 }
 749
 750 static int ubus_event_cb(struct ubus_context *ctx, struct ubus_object *obj,
 751                          struct ubus_request_data *req,
 752                          const char *method, struct blob_attr *msg)
 753 {
 754         struct ubus_event_handler *ev;
 755
 756         ev = container_of(obj, struct ubus_event_handler, obj);
 757         ev->cb(ctx, ev, method, msg);
 758         return 0;
 759 }
 760
 761 static const struct ubus_method event_method = {
 762         .name = NULL,
 763         .handler = ubus_event_cb,
 764 };
 765
 766 int ubus_register_event_handler(struct ubus_context *ctx,
 767                                 struct ubus_event_handler *ev,
 768                                 const char *pattern)
 769 {
 770         struct ubus_object *obj = &ev->obj;
 771         struct blob_buf b2;
 772         int ret;
 773
 774         if (!obj->id) {
 775                 obj->methods = &event_method;
 776                 obj->n_methods = 1;
 777
 778                 if (!!obj->name ^ !!obj->type)
 779                         return UBUS_STATUS_INVALID_ARGUMENT;
 780
 781                 ret = __ubus_add_object(ctx, obj);
 782                 if (ret)
 783                         return ret;
 784         }
 785
 786         /* use a second buffer, ubus_invoke() overwrites the primary one */
 787         memset(&b2, 0, sizeof(b2));
 788         blob_buf_init(&b2, 0);
 789         blobmsg_add_u32(&b2, "object", obj->id);
 790         if (pattern)
 791                 blobmsg_add_string(&b2, "pattern", pattern);
 792
 793         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_EVENT, "register", b2.head,
 794                           NULL, NULL, 0);
 795 }
 796
 797 int ubus_send_event(struct ubus_context *ctx, const char *id,
 798                     struct blob_attr *data)
 799 {
 800         struct ubus_request req;
 801         void *s;
 802
 803         blob_buf_init(&b, 0);
 804         blob_put_int32(&b, UBUS_ATTR_OBJID, UBUS_SYSTEM_OBJECT_EVENT);
 805         blob_put_string(&b, UBUS_ATTR_METHOD, "send");
 806         s = blob_nest_start(&b, UBUS_ATTR_DATA);
 807         blobmsg_add_string(&b, "id", id);
 808         blobmsg_add_field(&b, BLOBMSG_TYPE_TABLE, "data", blob_data(data), blob_len(data));
 809         blob_nest_end(&b, s);
 810
 811         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_INVOKE, UBUS_SYSTEM_OBJECT_EVENT) < 0)
 812                 return UBUS_STATUS_INVALID_ARGUMENT;
 813
 814         return ubus_complete_request(ctx, &req, 0);
 815 }
 816
 817 static void ubus_default_connection_lost(struct ubus_context *ctx)
 818 {
 819         if (ctx->sock.registered)
 820                 uloop_end();
 821 }
 822
 823 struct ubus_context *ubus_connect(const char *path)
 824 {
 825         struct ubus_context *ctx;
 826         struct {
 827                 struct ubus_msghdr hdr;
 828                 struct blob_attr data;
 829         } hdr;
 830         struct blob_attr *buf;
 831
 832         if (!path)
 833                 path = UBUS_UNIX_SOCKET;
 834
 835         ctx = calloc(1, sizeof(*ctx));
 836         if (!ctx)
 837                 goto error;
 838
 839         ctx->sock.fd = usock(USOCK_UNIX, path, NULL);
 840         if (ctx->sock.fd < 0)
 841                 goto error_free;
 842
 843         ctx->sock.cb = ubus_handle_data;
 844
 845         if (read(ctx->sock.fd, &hdr, sizeof(hdr)) != sizeof(hdr))
 846                 goto error_close;
 847
 848         if (!ubus_validate_hdr(&hdr.hdr))
 849                 goto error_close;
 850
 851         if (hdr.hdr.type != UBUS_MSG_HELLO)
 852                 goto error_close;
 853
 854         buf = calloc(1, blob_raw_len(&hdr.data));
 855         if (!buf)
 856                 goto error_close;
 857
 858         memcpy(buf, &hdr.data, sizeof(hdr.data));
 859         if (read(ctx->sock.fd, blob_data(buf), blob_len(buf)) != blob_len(buf))
 860                 goto error_free_buf;
 861
 862         ctx->local_id = hdr.hdr.peer;
 863         free(buf);
 864
 865         ctx->connection_lost = ubus_default_connection_lost;
 866
 867         INIT_LIST_HEAD(&ctx->requests);
 868         avl_init(&ctx->objects, ubus_cmp_id, false, NULL);
 869
 870         if (!ctx->local_id)
 871                 goto error_close;
 872
 873         fcntl(ctx->sock.fd, F_SETFL, fcntl(ctx->sock.fd, F_GETFL) | O_NONBLOCK);
 874
 875         return ctx;
 876
 877 error_free_buf:
 878         free(buf);
 879 error_close:
 880         close(ctx->sock.fd);
 881 error_free:
 882         free(ctx);
 883 error:
 884         return NULL;
 885 }
 886
 887 void ubus_free(struct ubus_context *ctx)
 888 {
 889         close(ctx->sock.fd);
 890         free(ctx);
 891 }