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         [UBUS_STATUS_CONNECTION_FAILED] = "Connection failed",
  42 };
  43
  44 static struct blob_buf b;
  45
  46 static const struct blob_attr_info ubus_policy[UBUS_ATTR_MAX] = {
  47         [UBUS_ATTR_STATUS] = { .type = BLOB_ATTR_INT32 },
  48         [UBUS_ATTR_OBJID] = { .type = BLOB_ATTR_INT32 },
  49         [UBUS_ATTR_OBJPATH] = { .type = BLOB_ATTR_STRING },
  50         [UBUS_ATTR_METHOD] = { .type = BLOB_ATTR_STRING },
  51 };
  52 static struct blob_attr *attrbuf[UBUS_ATTR_MAX];
  53
  54 struct ubus_pending_data {
  55         struct list_head list;
  56         int type;
  57         struct blob_attr data[];
  58 };
  59
  60 struct ubus_pending_invoke {
  61         struct list_head list;
  62         struct ubus_msghdr hdr;
  63 };
  64
  65 static void ubus_process_pending_invoke(struct ubus_context *ctx);
  66
  67 static int ubus_cmp_id(const void *k1, const void *k2, void *ptr)
  68 {
  69         const uint32_t *id1 = k1, *id2 = k2;
  70
  71         if (*id1 < *id2)
  72                 return -1;
  73         else
  74                 return *id1 > *id2;
  75 }
  76
  77 static struct blob_attr **ubus_parse_msg(struct blob_attr *msg)
  78 {
  79         blob_parse(msg, attrbuf, ubus_policy, UBUS_ATTR_MAX);
  80         return attrbuf;
  81 }
  82
  83 const char *ubus_strerror(int error)
  84 {
  85         static char err[32];
  86
  87         if (error < 0 || error >= __UBUS_STATUS_LAST)
  88                 goto out;
  89
  90         if (!__ubus_strerror[error])
  91                 goto out;
  92
  93         return __ubus_strerror[error];
  94
  95 out:
  96         sprintf(err, "Unknown error: %d", error);
  97         return err;
  98 }
  99
 100 static void wait_data(int fd, bool write)
 101 {
 102         struct pollfd pfd = { .fd = fd };
 103
 104         pfd.events = write ? POLLOUT : POLLIN;
 105         poll(&pfd, 1, 0);
 106 }
 107
 108 static int writev_retry(int fd, struct iovec *iov, int iov_len)
 109 {
 110         int len = 0;
 111
 112         do {
 113                 int cur_len = writev(fd, iov, iov_len);
 114                 if (cur_len < 0) {
 115                         switch(errno) {
 116                         case EAGAIN:
 117                                 wait_data(fd, true);
 118                                 break;
 119                         case EINTR:
 120                                 break;
 121                         default:
 122                                 return -1;
 123                         }
 124                         continue;
 125                 }
 126                 len += cur_len;
 127                 while (cur_len >= iov->iov_len) {
 128                         cur_len -= iov->iov_len;
 129                         iov_len--;
 130                         iov++;
 131                         if (!cur_len || !iov_len)
 132                                 return len;
 133                 }
 134                 iov->iov_len -= cur_len;
 135         } while (1);
 136 }
 137
 138 static int ubus_send_msg(struct ubus_context *ctx, uint32_t seq,
 139                          struct blob_attr *msg, int cmd, uint32_t peer)
 140 {
 141         struct ubus_msghdr hdr;
 142         struct iovec iov[2] = {
 143                 STATIC_IOV(hdr)
 144         };
 145
 146         hdr.version = 0;
 147         hdr.type = cmd;
 148         hdr.seq = seq;
 149         hdr.peer = peer;
 150
 151         if (!msg) {
 152                 blob_buf_init(&b, 0);
 153                 msg = b.head;
 154         }
 155
 156         iov[1].iov_base = (char *) msg;
 157         iov[1].iov_len = blob_raw_len(msg);
 158
 159         return writev_retry(ctx->sock.fd, iov, ARRAY_SIZE(iov));
 160 }
 161
 162 static int ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
 163                               struct blob_attr *msg, int cmd, uint32_t peer)
 164 {
 165         memset(req, 0, sizeof(*req));
 166
 167         if (msg && blob_pad_len(msg) > UBUS_MAX_MSGLEN)
 168                 return -1;
 169
 170         INIT_LIST_HEAD(&req->list);
 171         INIT_LIST_HEAD(&req->pending);
 172         req->ctx = ctx;
 173         req->peer = peer;
 174         req->seq = ++ctx->request_seq;
 175         return ubus_send_msg(ctx, req->seq, msg, cmd, peer);
 176 }
 177
 178 static bool recv_retry(int fd, struct iovec *iov, bool wait)
 179 {
 180         int bytes;
 181
 182         while (iov->iov_len > 0) {
 183                 if (wait)
 184                         wait_data(fd, false);
 185
 186                 bytes = read(fd, iov->iov_base, iov->iov_len);
 187                 if (bytes < 0) {
 188                         bytes = 0;
 189                         if (uloop_cancelled)
 190                                 return false;
 191                         if (errno == EINTR)
 192                                 continue;
 193
 194                         if (errno != EAGAIN)
 195                                 return false;
 196                 }
 197                 if (!wait && !bytes)
 198                         return false;
 199
 200                 wait = true;
 201                 iov->iov_len -= bytes;
 202                 iov->iov_base += bytes;
 203         }
 204
 205         return true;
 206 }
 207
 208 static bool ubus_validate_hdr(struct ubus_msghdr *hdr)
 209 {
 210         if (hdr->version != 0)
 211                 return false;
 212
 213         if (blob_raw_len(hdr->data) < sizeof(*hdr->data))
 214                 return false;
 215
 216         if (blob_pad_len(hdr->data) > UBUS_MAX_MSGLEN)
 217                 return false;
 218
 219         return true;
 220 }
 221
 222 static bool get_next_msg(struct ubus_context *ctx)
 223 {
 224         struct iovec iov = STATIC_IOV(ctx->msgbuf.hdr);
 225
 226         /* receive header + start attribute */
 227         iov.iov_len += sizeof(struct blob_attr);
 228         if (!recv_retry(ctx->sock.fd, &iov, false))
 229                 return false;
 230
 231         iov.iov_len = blob_len(ctx->msgbuf.hdr.data);
 232         if (iov.iov_len > 0 && !recv_retry(ctx->sock.fd, &iov, true))
 233                 return false;
 234
 235         return ubus_validate_hdr(&ctx->msgbuf.hdr);
 236 }
 237
 238 static bool ubus_get_status(struct ubus_msghdr *hdr, int *ret)
 239 {
 240         ubus_parse_msg(hdr->data);
 241
 242         if (!attrbuf[UBUS_ATTR_STATUS])
 243                 return false;
 244
 245         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 246         return true;
 247 }
 248
 249 static void req_data_cb(struct ubus_request *req, int type, struct blob_attr *data)
 250 {
 251         struct blob_attr **attr;
 252
 253         if (req->raw_data_cb)
 254                 req->raw_data_cb(req, type, data);
 255
 256         if (!req->data_cb)
 257                 return;
 258
 259         attr = ubus_parse_msg(data);
 260         req->data_cb(req, type, attr[UBUS_ATTR_DATA]);
 261 }
 262
 263 static void ubus_process_req_data(struct ubus_request *req)
 264 {
 265         struct ubus_pending_data *data;
 266
 267         while (!list_empty(&req->pending)) {
 268                 data = list_first_entry(&req->pending,
 269                         struct ubus_pending_data, list);
 270                 list_del(&data->list);
 271                 if (!req->cancelled)
 272                         req_data_cb(req, data->type, data->data);
 273                 free(data);
 274         }
 275 }
 276
 277 static void ubus_req_complete_cb(struct ubus_request *req)
 278 {
 279         ubus_complete_handler_t cb = req->complete_cb;
 280
 281         if (!cb)
 282                 return;
 283
 284         req->complete_cb = NULL;
 285         cb(req, req->status_code);
 286 }
 287
 288 static int ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr *hdr)
 289 {
 290         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 291
 292         if (!list_empty(&req->list))
 293                 list_del_init(&req->list);
 294
 295         ubus_get_status(hdr, &ret);
 296         req->peer = hdr->peer;
 297         req->status_msg = true;
 298         req->status_code = ret;
 299         if (!req->blocked)
 300                 ubus_req_complete_cb(req);
 301
 302         return ret;
 303 }
 304
 305 static void ubus_req_data(struct ubus_request *req, struct ubus_msghdr *hdr)
 306 {
 307         struct ubus_pending_data *data;
 308         int len;
 309
 310         if (!req->blocked) {
 311                 req->blocked = true;
 312                 req_data_cb(req, hdr->type, hdr->data);
 313                 ubus_process_req_data(req);
 314                 req->blocked = false;
 315
 316                 if (req->status_msg)
 317                         ubus_req_complete_cb(req);
 318
 319                 return;
 320         }
 321
 322         len = blob_raw_len(hdr->data);
 323         data = calloc(1, sizeof(*data) + len);
 324         if (!data)
 325                 return;
 326
 327         data->type = hdr->type;
 328         memcpy(data->data, hdr->data, len);
 329         list_add(&data->list, &req->pending);
 330 }
 331
 332 static struct ubus_request *ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer)
 333 {
 334         struct ubus_request *req;
 335
 336         list_for_each_entry(req, &ctx->requests, list) {
 337                 if (seq != req->seq || peer != req->peer)
 338                         continue;
 339
 340                 return req;
 341         }
 342         return NULL;
 343 }
 344
 345 static void ubus_process_invoke(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 346 {
 347         struct ubus_request_data req;
 348         struct ubus_object *obj;
 349         uint32_t objid = 0;
 350         int method;
 351         int ret = 0;
 352
 353         req.peer = hdr->peer;
 354         req.seq = hdr->seq;
 355         ubus_parse_msg(hdr->data);
 356
 357         if (!attrbuf[UBUS_ATTR_OBJID])
 358                 return;
 359
 360         objid = blob_get_u32(attrbuf[UBUS_ATTR_OBJID]);
 361
 362         if (!attrbuf[UBUS_ATTR_METHOD]) {
 363                 ret = UBUS_STATUS_INVALID_ARGUMENT;
 364                 goto send;
 365         }
 366
 367         obj = avl_find_element(&ctx->objects, &objid, obj, avl);
 368         if (!obj) {
 369                 ret = UBUS_STATUS_NOT_FOUND;
 370                 goto send;
 371         }
 372
 373         for (method = 0; method < obj->n_methods; method++)
 374                 if (!obj->methods[method].name ||
 375                     !strcmp(obj->methods[method].name,
 376                             blob_data(attrbuf[UBUS_ATTR_METHOD])))
 377                         goto found;
 378
 379         /* not found */
 380         ret = UBUS_STATUS_METHOD_NOT_FOUND;
 381         goto send;
 382
 383 found:
 384         req.object = objid;
 385         ret = obj->methods[method].handler(ctx, obj, &req,
 386                                            blob_data(attrbuf[UBUS_ATTR_METHOD]),
 387                                            attrbuf[UBUS_ATTR_DATA]);
 388
 389 send:
 390         blob_buf_init(&b, 0);
 391         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 392         blob_put_int32(&b, UBUS_ATTR_OBJID, objid);
 393         ubus_send_msg(ctx, req.seq, b.head, UBUS_MSG_STATUS, req.peer);
 394 }
 395
 396 static void ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 397 {
 398         struct ubus_pending_invoke *pending;
 399         struct ubus_request *req;
 400
 401         switch(hdr->type) {
 402         case UBUS_MSG_STATUS:
 403                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 404                 if (!req)
 405                         break;
 406
 407                 ubus_process_req_status(req, hdr);
 408                 break;
 409
 410         case UBUS_MSG_DATA:
 411                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 412                 if (req && (req->data_cb || req->raw_data_cb))
 413                         ubus_req_data(req, hdr);
 414                 break;
 415
 416         case UBUS_MSG_INVOKE:
 417                 if (ctx->stack_depth > 2) {
 418                         pending = calloc(1, sizeof(*pending) +
 419                                 blob_raw_len(hdr->data));
 420
 421                         if (!pending)
 422                                 return;
 423
 424                         memcpy(&pending->hdr, hdr, sizeof(*hdr) +
 425                                 blob_raw_len(hdr->data));
 426                         list_add(&pending->list, &ctx->pending);
 427                 } else {
 428                         ubus_process_invoke(ctx, hdr);
 429                 }
 430                 break;
 431         }
 432 }
 433
 434 static void ubus_process_pending_invoke(struct ubus_context *ctx)
 435 {
 436         struct ubus_pending_invoke *pending, *tmp;
 437
 438         list_for_each_entry_safe(pending, tmp, &ctx->pending, list) {
 439                 list_del(&pending->list);
 440                 ubus_process_msg(ctx, &pending->hdr);
 441                 free(pending);
 442                 if (ctx->stack_depth > 2)
 443                         break;
 444         }
 445 }
 446
 447 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
 448 {
 449         if (!list_empty(&req->list))
 450                 return;
 451
 452         req->cancelled = true;
 453         ubus_process_req_data(req);
 454         list_del_init(&req->list);
 455 }
 456
 457 void ubus_complete_request_async(struct ubus_context *ctx, struct ubus_request *req)
 458 {
 459         if (!list_empty(&req->list))
 460                 return;
 461
 462         list_add(&req->list, &ctx->requests);
 463 }
 464
 465 static void ubus_handle_data(struct uloop_fd *u, unsigned int events)
 466 {
 467         struct ubus_context *ctx = container_of(u, struct ubus_context, sock);
 468         struct ubus_msghdr *hdr = &ctx->msgbuf.hdr;
 469
 470         while (get_next_msg(ctx)) {
 471                 ubus_process_msg(ctx, hdr);
 472                 if (uloop_cancelled)
 473                         break;
 474         }
 475
 476         if (u->eof)
 477                 ctx->connection_lost(ctx);
 478 }
 479
 480 static void ubus_sync_req_cb(struct ubus_request *req, int ret)
 481 {
 482         req->status_msg = true;
 483         req->status_code = ret;
 484         uloop_end();
 485 }
 486
 487 struct ubus_sync_req_cb {
 488         struct uloop_timeout timeout;
 489         struct ubus_request *req;
 490 };
 491
 492 static void ubus_sync_req_timeout_cb(struct uloop_timeout *timeout)
 493 {
 494         struct ubus_sync_req_cb *cb;
 495
 496         cb = container_of(timeout, struct ubus_sync_req_cb, timeout);
 497         ubus_sync_req_cb(cb->req, UBUS_STATUS_TIMEOUT);
 498 }
 499
 500 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 501                           int timeout)
 502 {
 503         struct ubus_sync_req_cb cb;
 504         ubus_complete_handler_t complete_cb = req->complete_cb;
 505         bool registered = ctx->sock.registered;
 506         int status = UBUS_STATUS_NO_DATA;
 507
 508         if (!registered) {
 509                 uloop_init();
 510                 ubus_add_uloop(ctx);
 511         }
 512
 513         if (timeout) {
 514                 memset(&cb, 0, sizeof(cb));
 515                 cb.req = req;
 516                 cb.timeout.cb = ubus_sync_req_timeout_cb;
 517                 uloop_timeout_set(&cb.timeout, timeout);
 518         }
 519
 520         ubus_complete_request_async(ctx, req);
 521         req->complete_cb = ubus_sync_req_cb;
 522
 523         ctx->stack_depth++;
 524         while (!req->status_msg) {
 525                 bool cancelled = uloop_cancelled;
 526                 uloop_cancelled = false;
 527                 uloop_run();
 528                 uloop_cancelled = cancelled;
 529         }
 530         ctx->stack_depth--;
 531
 532         if (timeout)
 533                 uloop_timeout_cancel(&cb.timeout);
 534
 535         if (req->status_msg)
 536                 status = req->status_code;
 537
 538         req->complete_cb = complete_cb;
 539         if (req->complete_cb)
 540                 req->complete_cb(req, status);
 541
 542         if (!registered)
 543                 uloop_fd_delete(&ctx->sock);
 544
 545         if (!ctx->stack_depth)
 546                 ubus_process_pending_invoke(ctx);
 547
 548         return status;
 549 }
 550
 551 struct ubus_lookup_request {
 552         struct ubus_request req;
 553         ubus_lookup_handler_t cb;
 554 };
 555
 556 static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr *msg)
 557 {
 558         struct ubus_lookup_request *req;
 559         struct ubus_object_data obj;
 560         struct blob_attr **attr;
 561
 562         req = container_of(ureq, struct ubus_lookup_request, req);
 563         attr = ubus_parse_msg(msg);
 564
 565         if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_OBJPATH] ||
 566             !attr[UBUS_ATTR_OBJTYPE])
 567                 return;
 568
 569         memset(&obj, 0, sizeof(obj));
 570         obj.id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 571         obj.path = blob_data(attr[UBUS_ATTR_OBJPATH]);
 572         obj.type_id = blob_get_u32(attr[UBUS_ATTR_OBJTYPE]);
 573         obj.signature = attr[UBUS_ATTR_SIGNATURE];
 574         req->cb(ureq->ctx, &obj, ureq->priv);
 575 }
 576
 577 int ubus_lookup(struct ubus_context *ctx, const char *path,
 578                 ubus_lookup_handler_t cb, void *priv)
 579 {
 580         struct ubus_lookup_request lookup;
 581
 582         blob_buf_init(&b, 0);
 583         if (path)
 584                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 585
 586         if (ubus_start_request(ctx, &lookup.req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 587                 return UBUS_STATUS_INVALID_ARGUMENT;
 588
 589         lookup.req.raw_data_cb = ubus_lookup_cb;
 590         lookup.req.priv = priv;
 591         lookup.cb = cb;
 592         return ubus_complete_request(ctx, &lookup.req, 0);
 593 }
 594
 595 static void ubus_lookup_id_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 596 {
 597         struct blob_attr **attr;
 598         uint32_t *id = req->priv;
 599
 600         attr = ubus_parse_msg(msg);
 601
 602         if (!attr[UBUS_ATTR_OBJID])
 603                 return;
 604
 605         *id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 606 }
 607
 608 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id)
 609 {
 610         struct ubus_request req;
 611
 612         blob_buf_init(&b, 0);
 613         if (path)
 614                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 615
 616         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 617                 return UBUS_STATUS_INVALID_ARGUMENT;
 618
 619         req.raw_data_cb = ubus_lookup_id_cb;
 620         req.priv = id;
 621
 622         return ubus_complete_request(ctx, &req, 0);
 623 }
 624
 625 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 626                     struct blob_attr *msg)
 627 {
 628         int ret;
 629
 630         blob_buf_init(&b, 0);
 631         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 632         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 633         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer);
 634         if (ret < 0)
 635                 return UBUS_STATUS_NO_DATA;
 636
 637         return 0;
 638 }
 639
 640 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 641                        struct blob_attr *msg, struct ubus_request *req)
 642 {
 643         blob_buf_init(&b, 0);
 644         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 645         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 646         if (msg)
 647                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 648
 649         if (ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 650                 return UBUS_STATUS_INVALID_ARGUMENT;
 651
 652         return 0;
 653 }
 654
 655 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 656                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 657                 int timeout)
 658 {
 659         struct ubus_request req;
 660
 661         ubus_invoke_async(ctx, obj, method, msg, &req);
 662         req.data_cb = cb;
 663         req.priv = priv;
 664         return ubus_complete_request(ctx, &req, timeout);
 665 }
 666
 667 static void ubus_add_object_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 668 {
 669         struct ubus_object *obj = req->priv;
 670
 671         ubus_parse_msg(msg);
 672
 673         if (!attrbuf[UBUS_ATTR_OBJID])
 674                 return;
 675
 676         obj->id = blob_get_u32(attrbuf[UBUS_ATTR_OBJID]);
 677
 678         if (attrbuf[UBUS_ATTR_OBJTYPE])
 679                 obj->type->id = blob_get_u32(attrbuf[UBUS_ATTR_OBJTYPE]);
 680
 681         obj->avl.key = &obj->id;
 682         avl_insert(&req->ctx->objects, &obj->avl);
 683 }
 684
 685 static void ubus_push_method_data(const struct ubus_method *m)
 686 {
 687         void *mtbl;
 688         int i;
 689
 690         mtbl = blobmsg_open_table(&b, m->name);
 691
 692         for (i = 0; i < m->n_policy; i++)
 693                 blobmsg_add_u32(&b, m->policy[i].name, m->policy[i].type);
 694
 695         blobmsg_close_table(&b, mtbl);
 696 }
 697
 698 static bool ubus_push_object_type(const struct ubus_object_type *type)
 699 {
 700         void *s;
 701         int i;
 702
 703         s = blob_nest_start(&b, UBUS_ATTR_SIGNATURE);
 704
 705         for (i = 0; i < type->n_methods; i++)
 706                 ubus_push_method_data(&type->methods[i]);
 707
 708         blob_nest_end(&b, s);
 709
 710         return true;
 711 }
 712
 713 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj)
 714 {
 715         struct ubus_request req;
 716         int ret;
 717
 718         blob_buf_init(&b, 0);
 719
 720         if (obj->name && obj->type) {
 721                 blob_put_string(&b, UBUS_ATTR_OBJPATH, obj->name);
 722
 723                 if (obj->type->id)
 724                         blob_put_int32(&b, UBUS_ATTR_OBJTYPE, obj->type->id);
 725                 else if (!ubus_push_object_type(obj->type))
 726                         return UBUS_STATUS_INVALID_ARGUMENT;
 727         }
 728
 729         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_ADD_OBJECT, 0) < 0)
 730                 return UBUS_STATUS_INVALID_ARGUMENT;
 731
 732         req.raw_data_cb = ubus_add_object_cb;
 733         req.priv = obj;
 734         ret = ubus_complete_request(ctx, &req, 0);
 735         if (ret)
 736                 return ret;
 737
 738         if (!obj->id)
 739                 return UBUS_STATUS_NO_DATA;
 740
 741         return 0;
 742 }
 743
 744 static void ubus_remove_object_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 745 {
 746         struct ubus_object *obj = req->priv;
 747
 748         ubus_parse_msg(msg);
 749
 750         if (!attrbuf[UBUS_ATTR_OBJID])
 751                 return;
 752
 753         obj->id = 0;
 754
 755         if (attrbuf[UBUS_ATTR_OBJTYPE] && obj->type)
 756                 obj->type->id = 0;
 757
 758         avl_delete(&req->ctx->objects, &obj->avl);
 759 }
 760
 761 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj)
 762 {
 763         struct ubus_request req;
 764         int ret;
 765
 766         blob_buf_init(&b, 0);
 767         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 768
 769         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_REMOVE_OBJECT, 0) < 0)
 770                 return UBUS_STATUS_INVALID_ARGUMENT;
 771
 772         req.raw_data_cb = ubus_remove_object_cb;
 773         req.priv = obj;
 774         ret = ubus_complete_request(ctx, &req, 0);
 775         if (ret)
 776                 return ret;
 777
 778         if (obj->id)
 779                 return UBUS_STATUS_NO_DATA;
 780
 781         return 0;
 782 }
 783
 784 static int ubus_event_cb(struct ubus_context *ctx, struct ubus_object *obj,
 785                          struct ubus_request_data *req,
 786                          const char *method, struct blob_attr *msg)
 787 {
 788         struct ubus_event_handler *ev;
 789
 790         ev = container_of(obj, struct ubus_event_handler, obj);
 791         ev->cb(ctx, ev, method, msg);
 792         return 0;
 793 }
 794
 795 static const struct ubus_method event_method = {
 796         .name = NULL,
 797         .handler = ubus_event_cb,
 798 };
 799
 800 int ubus_register_event_handler(struct ubus_context *ctx,
 801                                 struct ubus_event_handler *ev,
 802                                 const char *pattern)
 803 {
 804         struct ubus_object *obj = &ev->obj;
 805         struct blob_buf b2;
 806         int ret;
 807
 808         if (!obj->id) {
 809                 obj->methods = &event_method;
 810                 obj->n_methods = 1;
 811
 812                 if (!!obj->name ^ !!obj->type)
 813                         return UBUS_STATUS_INVALID_ARGUMENT;
 814
 815                 ret = ubus_add_object(ctx, obj);
 816                 if (ret)
 817                         return ret;
 818         }
 819
 820         /* use a second buffer, ubus_invoke() overwrites the primary one */
 821         memset(&b2, 0, sizeof(b2));
 822         blob_buf_init(&b2, 0);
 823         blobmsg_add_u32(&b2, "object", obj->id);
 824         if (pattern)
 825                 blobmsg_add_string(&b2, "pattern", pattern);
 826
 827         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_EVENT, "register", b2.head,
 828                           NULL, NULL, 0);
 829 }
 830
 831 enum {
 832         WATCH_ID,
 833         WATCH_NOTIFY,
 834         __WATCH_MAX
 835 };
 836
 837 static const struct blobmsg_policy watch_policy[] = {
 838         [WATCH_ID] = { .name = "id", .type = BLOBMSG_TYPE_INT32 },
 839         [WATCH_NOTIFY] = { .name = "notify", .type = BLOBMSG_TYPE_STRING },
 840 };
 841
 842
 843 static int ubus_watch_cb(struct ubus_context *ctx, struct ubus_object *obj,
 844                          struct ubus_request_data *req,
 845                          const char *method, struct blob_attr *msg)
 846 {
 847         struct ubus_watch_object *w;
 848         struct blob_attr *tb[__WATCH_MAX];
 849
 850         blobmsg_parse(watch_policy, ARRAY_SIZE(watch_policy), tb, blob_data(msg), blob_len(msg));
 851
 852         if (!tb[WATCH_ID] || !tb[WATCH_NOTIFY])
 853                 return UBUS_STATUS_INVALID_ARGUMENT;
 854
 855         if (req->peer)
 856                 return UBUS_STATUS_INVALID_ARGUMENT;
 857
 858         w = container_of(obj, struct ubus_watch_object, obj);
 859         w->cb(ctx, w, blobmsg_get_u32(tb[WATCH_ID]));
 860         return 0;
 861 }
 862
 863 static const struct ubus_method watch_method = {
 864         .name = NULL,
 865         .handler = ubus_watch_cb,
 866 };
 867
 868 int ubus_register_watch_object(struct ubus_context *ctx, struct ubus_watch_object *w_obj)
 869 {
 870         struct ubus_object *obj = &w_obj->obj;
 871
 872         obj->methods = &watch_method;
 873         obj->n_methods = 1;
 874
 875         return ubus_add_object(ctx, obj);
 876 }
 877
 878 static int
 879 __ubus_watch_request(struct ubus_context *ctx, struct ubus_object *obj, uint32_t id, const char *method, int type)
 880 {
 881         struct ubus_request req;
 882
 883         blob_buf_init(&b, 0);
 884         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 885         blob_put_int32(&b, UBUS_ATTR_TARGET, id);
 886         if (method)
 887                 blob_put_string(&b, UBUS_ATTR_METHOD, method);
 888
 889         if (ubus_start_request(ctx, &req, b.head, type, 0) < 0)
 890                 return UBUS_STATUS_INVALID_ARGUMENT;
 891
 892         return ubus_complete_request(ctx, &req, 0);
 893
 894 }
 895
 896 int ubus_watch_object_add(struct ubus_context *ctx, struct ubus_watch_object *obj, uint32_t id)
 897 {
 898         return __ubus_watch_request(ctx, &obj->obj, id, "event", UBUS_MSG_ADD_WATCH);
 899 }
 900
 901 int ubus_watch_object_remove(struct ubus_context *ctx, struct ubus_watch_object *obj, uint32_t id)
 902 {
 903         return __ubus_watch_request(ctx, &obj->obj, id, NULL, UBUS_MSG_REMOVE_WATCH);
 904 }
 905
 906 int ubus_send_event(struct ubus_context *ctx, const char *id,
 907                     struct blob_attr *data)
 908 {
 909         struct ubus_request req;
 910         void *s;
 911
 912         blob_buf_init(&b, 0);
 913         blob_put_int32(&b, UBUS_ATTR_OBJID, UBUS_SYSTEM_OBJECT_EVENT);
 914         blob_put_string(&b, UBUS_ATTR_METHOD, "send");
 915         s = blob_nest_start(&b, UBUS_ATTR_DATA);
 916         blobmsg_add_string(&b, "id", id);
 917         blobmsg_add_field(&b, BLOBMSG_TYPE_TABLE, "data", blob_data(data), blob_len(data));
 918         blob_nest_end(&b, s);
 919
 920         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_INVOKE, UBUS_SYSTEM_OBJECT_EVENT) < 0)
 921                 return UBUS_STATUS_INVALID_ARGUMENT;
 922
 923         return ubus_complete_request(ctx, &req, 0);
 924 }
 925
 926 static void
 927 ubus_refresh_state(struct ubus_context *ctx)
 928 {
 929         struct ubus_object *obj, *tmp;
 930
 931         /* clear all type IDs, they need to be registered again */
 932         avl_for_each_element(&ctx->objects, obj, avl)
 933                 obj->type->id = 0;
 934
 935         /* push out all objects again */
 936         avl_for_each_element_safe(&ctx->objects, obj, avl, tmp) {
 937                 obj->id = 0;
 938                 avl_delete(&ctx->objects, &obj->avl);
 939                 ubus_add_object(ctx, obj);
 940         }
 941 }
 942
 943 int ubus_reconnect(struct ubus_context *ctx, const char *path)
 944 {
 945         struct {
 946                 struct ubus_msghdr hdr;
 947                 struct blob_attr data;
 948         } hdr;
 949         struct blob_attr *buf;
 950         int ret = UBUS_STATUS_UNKNOWN_ERROR;
 951
 952         if (!path)
 953                 path = UBUS_UNIX_SOCKET;
 954
 955         if (ctx->sock.fd >= 0) {
 956                 if (ctx->sock.registered)
 957                         uloop_fd_delete(&ctx->sock);
 958
 959                 close(ctx->sock.fd);
 960         }
 961
 962         ctx->sock.fd = usock(USOCK_UNIX, path, NULL);
 963         if (ctx->sock.fd < 0)
 964                 return UBUS_STATUS_CONNECTION_FAILED;
 965
 966         if (read(ctx->sock.fd, &hdr, sizeof(hdr)) != sizeof(hdr))
 967                 goto out_close;
 968
 969         if (!ubus_validate_hdr(&hdr.hdr))
 970                 goto out_close;
 971
 972         if (hdr.hdr.type != UBUS_MSG_HELLO)
 973                 goto out_close;
 974
 975         buf = calloc(1, blob_raw_len(&hdr.data));
 976         if (!buf)
 977                 goto out_close;
 978
 979         memcpy(buf, &hdr.data, sizeof(hdr.data));
 980         if (read(ctx->sock.fd, blob_data(buf), blob_len(buf)) != blob_len(buf))
 981                 goto out_free;
 982
 983         ctx->local_id = hdr.hdr.peer;
 984         if (!ctx->local_id)
 985                 goto out_free;
 986
 987         ret = UBUS_STATUS_OK;
 988         fcntl(ctx->sock.fd, F_SETFL, fcntl(ctx->sock.fd, F_GETFL) | O_NONBLOCK);
 989
 990         ubus_refresh_state(ctx);
 991
 992 out_free:
 993         free(buf);
 994 out_close:
 995         if (ret)
 996                 close(ctx->sock.fd);
 997
 998         return ret;
 999 }
1000
1001 static void ubus_default_connection_lost(struct ubus_context *ctx)
1002 {
1003         if (ctx->sock.registered)
1004                 uloop_end();
1005 }
1006
1007 struct ubus_context *ubus_connect(const char *path)
1008 {
1009         struct ubus_context *ctx;
1010
1011         ctx = calloc(1, sizeof(*ctx));
1012         if (!ctx)
1013                 return NULL;
1014
1015         ctx->sock.fd = -1;
1016         ctx->sock.cb = ubus_handle_data;
1017         ctx->connection_lost = ubus_default_connection_lost;
1018
1019         INIT_LIST_HEAD(&ctx->requests);
1020         INIT_LIST_HEAD(&ctx->pending);
1021         avl_init(&ctx->objects, ubus_cmp_id, false, NULL);
1022         if (ubus_reconnect(ctx, path)) {
1023                 free(ctx);
1024                 ctx = NULL;
1025         }
1026
1027         return ctx;
1028 }
1029
1030 void ubus_free(struct ubus_context *ctx)
1031 {
1032         close(ctx->sock.fd);
1033         free(ctx);
1034 }