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 void ubus_complete_deferred_request(struct ubus_context *ctx, struct ubus_request_data *req, int ret)
 346 {
 347         blob_buf_init(&b, 0);
 348         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 349         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 350         ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_STATUS, req->peer);
 351 }
 352
 353 static void ubus_process_invoke(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 354 {
 355         struct ubus_request_data req;
 356         struct ubus_object *obj;
 357         int method;
 358         int ret = 0;
 359
 360         req.peer = hdr->peer;
 361         req.seq = hdr->seq;
 362         ubus_parse_msg(hdr->data);
 363
 364         if (!attrbuf[UBUS_ATTR_OBJID])
 365                 return;
 366
 367         req.object = blob_get_u32(attrbuf[UBUS_ATTR_OBJID]);
 368
 369         if (!attrbuf[UBUS_ATTR_METHOD]) {
 370                 ret = UBUS_STATUS_INVALID_ARGUMENT;
 371                 goto send;
 372         }
 373
 374         obj = avl_find_element(&ctx->objects, &req.object, obj, avl);
 375         if (!obj) {
 376                 ret = UBUS_STATUS_NOT_FOUND;
 377                 goto send;
 378         }
 379
 380         for (method = 0; method < obj->n_methods; method++)
 381                 if (!obj->methods[method].name ||
 382                     !strcmp(obj->methods[method].name,
 383                             blob_data(attrbuf[UBUS_ATTR_METHOD])))
 384                         goto found;
 385
 386         /* not found */
 387         ret = UBUS_STATUS_METHOD_NOT_FOUND;
 388         goto send;
 389
 390 found:
 391         ret = obj->methods[method].handler(ctx, obj, &req,
 392                                            blob_data(attrbuf[UBUS_ATTR_METHOD]),
 393                                            attrbuf[UBUS_ATTR_DATA]);
 394         if (req.deferred)
 395                 return;
 396
 397 send:
 398         ubus_complete_deferred_request(ctx, &req, ret);
 399 }
 400
 401 static void ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 402 {
 403         struct ubus_pending_invoke *pending;
 404         struct ubus_request *req;
 405
 406         switch(hdr->type) {
 407         case UBUS_MSG_STATUS:
 408                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 409                 if (!req)
 410                         break;
 411
 412                 ubus_process_req_status(req, hdr);
 413                 break;
 414
 415         case UBUS_MSG_DATA:
 416                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 417                 if (req && (req->data_cb || req->raw_data_cb))
 418                         ubus_req_data(req, hdr);
 419                 break;
 420
 421         case UBUS_MSG_INVOKE:
 422                 if (ctx->stack_depth > 2) {
 423                         pending = calloc(1, sizeof(*pending) +
 424                                 blob_raw_len(hdr->data));
 425
 426                         if (!pending)
 427                                 return;
 428
 429                         memcpy(&pending->hdr, hdr, sizeof(*hdr) +
 430                                 blob_raw_len(hdr->data));
 431                         list_add(&pending->list, &ctx->pending);
 432                 } else {
 433                         ubus_process_invoke(ctx, hdr);
 434                 }
 435                 break;
 436         }
 437 }
 438
 439 static void ubus_process_pending_invoke(struct ubus_context *ctx)
 440 {
 441         struct ubus_pending_invoke *pending, *tmp;
 442
 443         list_for_each_entry_safe(pending, tmp, &ctx->pending, list) {
 444                 list_del(&pending->list);
 445                 ubus_process_msg(ctx, &pending->hdr);
 446                 free(pending);
 447                 if (ctx->stack_depth > 2)
 448                         break;
 449         }
 450 }
 451
 452 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
 453 {
 454         if (!list_empty(&req->list))
 455                 return;
 456
 457         req->cancelled = true;
 458         ubus_process_req_data(req);
 459         list_del_init(&req->list);
 460 }
 461
 462 void ubus_complete_request_async(struct ubus_context *ctx, struct ubus_request *req)
 463 {
 464         if (!list_empty(&req->list))
 465                 return;
 466
 467         list_add(&req->list, &ctx->requests);
 468 }
 469
 470 static void ubus_handle_data(struct uloop_fd *u, unsigned int events)
 471 {
 472         struct ubus_context *ctx = container_of(u, struct ubus_context, sock);
 473         struct ubus_msghdr *hdr = &ctx->msgbuf.hdr;
 474
 475         while (get_next_msg(ctx)) {
 476                 ubus_process_msg(ctx, hdr);
 477                 if (uloop_cancelled)
 478                         break;
 479         }
 480
 481         if (u->eof)
 482                 ctx->connection_lost(ctx);
 483 }
 484
 485 static void ubus_sync_req_cb(struct ubus_request *req, int ret)
 486 {
 487         req->status_msg = true;
 488         req->status_code = ret;
 489         uloop_end();
 490 }
 491
 492 struct ubus_sync_req_cb {
 493         struct uloop_timeout timeout;
 494         struct ubus_request *req;
 495 };
 496
 497 static void ubus_sync_req_timeout_cb(struct uloop_timeout *timeout)
 498 {
 499         struct ubus_sync_req_cb *cb;
 500
 501         cb = container_of(timeout, struct ubus_sync_req_cb, timeout);
 502         ubus_sync_req_cb(cb->req, UBUS_STATUS_TIMEOUT);
 503 }
 504
 505 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 506                           int timeout)
 507 {
 508         struct ubus_sync_req_cb cb;
 509         ubus_complete_handler_t complete_cb = req->complete_cb;
 510         bool registered = ctx->sock.registered;
 511         int status = UBUS_STATUS_NO_DATA;
 512
 513         if (!registered) {
 514                 uloop_init();
 515                 ubus_add_uloop(ctx);
 516         }
 517
 518         if (timeout) {
 519                 memset(&cb, 0, sizeof(cb));
 520                 cb.req = req;
 521                 cb.timeout.cb = ubus_sync_req_timeout_cb;
 522                 uloop_timeout_set(&cb.timeout, timeout);
 523         }
 524
 525         ubus_complete_request_async(ctx, req);
 526         req->complete_cb = ubus_sync_req_cb;
 527
 528         ctx->stack_depth++;
 529         while (!req->status_msg) {
 530                 bool cancelled = uloop_cancelled;
 531                 uloop_cancelled = false;
 532                 uloop_run();
 533                 uloop_cancelled = cancelled;
 534         }
 535         ctx->stack_depth--;
 536
 537         if (timeout)
 538                 uloop_timeout_cancel(&cb.timeout);
 539
 540         if (req->status_msg)
 541                 status = req->status_code;
 542
 543         req->complete_cb = complete_cb;
 544         if (req->complete_cb)
 545                 req->complete_cb(req, status);
 546
 547         if (!registered)
 548                 uloop_fd_delete(&ctx->sock);
 549
 550         if (!ctx->stack_depth)
 551                 ubus_process_pending_invoke(ctx);
 552
 553         return status;
 554 }
 555
 556 struct ubus_lookup_request {
 557         struct ubus_request req;
 558         ubus_lookup_handler_t cb;
 559 };
 560
 561 static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr *msg)
 562 {
 563         struct ubus_lookup_request *req;
 564         struct ubus_object_data obj;
 565         struct blob_attr **attr;
 566
 567         req = container_of(ureq, struct ubus_lookup_request, req);
 568         attr = ubus_parse_msg(msg);
 569
 570         if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_OBJPATH] ||
 571             !attr[UBUS_ATTR_OBJTYPE])
 572                 return;
 573
 574         memset(&obj, 0, sizeof(obj));
 575         obj.id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 576         obj.path = blob_data(attr[UBUS_ATTR_OBJPATH]);
 577         obj.type_id = blob_get_u32(attr[UBUS_ATTR_OBJTYPE]);
 578         obj.signature = attr[UBUS_ATTR_SIGNATURE];
 579         req->cb(ureq->ctx, &obj, ureq->priv);
 580 }
 581
 582 int ubus_lookup(struct ubus_context *ctx, const char *path,
 583                 ubus_lookup_handler_t cb, void *priv)
 584 {
 585         struct ubus_lookup_request lookup;
 586
 587         blob_buf_init(&b, 0);
 588         if (path)
 589                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 590
 591         if (ubus_start_request(ctx, &lookup.req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 592                 return UBUS_STATUS_INVALID_ARGUMENT;
 593
 594         lookup.req.raw_data_cb = ubus_lookup_cb;
 595         lookup.req.priv = priv;
 596         lookup.cb = cb;
 597         return ubus_complete_request(ctx, &lookup.req, 0);
 598 }
 599
 600 static void ubus_lookup_id_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 601 {
 602         struct blob_attr **attr;
 603         uint32_t *id = req->priv;
 604
 605         attr = ubus_parse_msg(msg);
 606
 607         if (!attr[UBUS_ATTR_OBJID])
 608                 return;
 609
 610         *id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 611 }
 612
 613 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id)
 614 {
 615         struct ubus_request req;
 616
 617         blob_buf_init(&b, 0);
 618         if (path)
 619                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 620
 621         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 622                 return UBUS_STATUS_INVALID_ARGUMENT;
 623
 624         req.raw_data_cb = ubus_lookup_id_cb;
 625         req.priv = id;
 626
 627         return ubus_complete_request(ctx, &req, 0);
 628 }
 629
 630 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 631                     struct blob_attr *msg)
 632 {
 633         int ret;
 634
 635         blob_buf_init(&b, 0);
 636         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 637         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 638         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer);
 639         if (ret < 0)
 640                 return UBUS_STATUS_NO_DATA;
 641
 642         return 0;
 643 }
 644
 645 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 646                        struct blob_attr *msg, struct ubus_request *req)
 647 {
 648         blob_buf_init(&b, 0);
 649         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 650         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 651         if (msg)
 652                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 653
 654         if (ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 655                 return UBUS_STATUS_INVALID_ARGUMENT;
 656
 657         return 0;
 658 }
 659
 660 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 661                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 662                 int timeout)
 663 {
 664         struct ubus_request req;
 665
 666         ubus_invoke_async(ctx, obj, method, msg, &req);
 667         req.data_cb = cb;
 668         req.priv = priv;
 669         return ubus_complete_request(ctx, &req, timeout);
 670 }
 671
 672 static void ubus_add_object_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 673 {
 674         struct ubus_object *obj = req->priv;
 675
 676         ubus_parse_msg(msg);
 677
 678         if (!attrbuf[UBUS_ATTR_OBJID])
 679                 return;
 680
 681         obj->id = blob_get_u32(attrbuf[UBUS_ATTR_OBJID]);
 682
 683         if (attrbuf[UBUS_ATTR_OBJTYPE])
 684                 obj->type->id = blob_get_u32(attrbuf[UBUS_ATTR_OBJTYPE]);
 685
 686         obj->avl.key = &obj->id;
 687         avl_insert(&req->ctx->objects, &obj->avl);
 688 }
 689
 690 static void ubus_push_method_data(const struct ubus_method *m)
 691 {
 692         void *mtbl;
 693         int i;
 694
 695         mtbl = blobmsg_open_table(&b, m->name);
 696
 697         for (i = 0; i < m->n_policy; i++)
 698                 blobmsg_add_u32(&b, m->policy[i].name, m->policy[i].type);
 699
 700         blobmsg_close_table(&b, mtbl);
 701 }
 702
 703 static bool ubus_push_object_type(const struct ubus_object_type *type)
 704 {
 705         void *s;
 706         int i;
 707
 708         s = blob_nest_start(&b, UBUS_ATTR_SIGNATURE);
 709
 710         for (i = 0; i < type->n_methods; i++)
 711                 ubus_push_method_data(&type->methods[i]);
 712
 713         blob_nest_end(&b, s);
 714
 715         return true;
 716 }
 717
 718 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj)
 719 {
 720         struct ubus_request req;
 721         int ret;
 722
 723         blob_buf_init(&b, 0);
 724
 725         if (obj->name && obj->type) {
 726                 blob_put_string(&b, UBUS_ATTR_OBJPATH, obj->name);
 727
 728                 if (obj->type->id)
 729                         blob_put_int32(&b, UBUS_ATTR_OBJTYPE, obj->type->id);
 730                 else if (!ubus_push_object_type(obj->type))
 731                         return UBUS_STATUS_INVALID_ARGUMENT;
 732         }
 733
 734         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_ADD_OBJECT, 0) < 0)
 735                 return UBUS_STATUS_INVALID_ARGUMENT;
 736
 737         req.raw_data_cb = ubus_add_object_cb;
 738         req.priv = obj;
 739         ret = ubus_complete_request(ctx, &req, 0);
 740         if (ret)
 741                 return ret;
 742
 743         if (!obj->id)
 744                 return UBUS_STATUS_NO_DATA;
 745
 746         return 0;
 747 }
 748
 749 static void ubus_remove_object_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 750 {
 751         struct ubus_object *obj = req->priv;
 752
 753         ubus_parse_msg(msg);
 754
 755         if (!attrbuf[UBUS_ATTR_OBJID])
 756                 return;
 757
 758         obj->id = 0;
 759
 760         if (attrbuf[UBUS_ATTR_OBJTYPE] && obj->type)
 761                 obj->type->id = 0;
 762
 763         avl_delete(&req->ctx->objects, &obj->avl);
 764 }
 765
 766 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj)
 767 {
 768         struct ubus_request req;
 769         int ret;
 770
 771         blob_buf_init(&b, 0);
 772         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 773
 774         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_REMOVE_OBJECT, 0) < 0)
 775                 return UBUS_STATUS_INVALID_ARGUMENT;
 776
 777         req.raw_data_cb = ubus_remove_object_cb;
 778         req.priv = obj;
 779         ret = ubus_complete_request(ctx, &req, 0);
 780         if (ret)
 781                 return ret;
 782
 783         if (obj->id)
 784                 return UBUS_STATUS_NO_DATA;
 785
 786         return 0;
 787 }
 788
 789 static int ubus_event_cb(struct ubus_context *ctx, struct ubus_object *obj,
 790                          struct ubus_request_data *req,
 791                          const char *method, struct blob_attr *msg)
 792 {
 793         struct ubus_event_handler *ev;
 794
 795         ev = container_of(obj, struct ubus_event_handler, obj);
 796         ev->cb(ctx, ev, method, msg);
 797         return 0;
 798 }
 799
 800 static const struct ubus_method event_method = {
 801         .name = NULL,
 802         .handler = ubus_event_cb,
 803 };
 804
 805 int ubus_register_event_handler(struct ubus_context *ctx,
 806                                 struct ubus_event_handler *ev,
 807                                 const char *pattern)
 808 {
 809         struct ubus_object *obj = &ev->obj;
 810         struct blob_buf b2;
 811         int ret;
 812
 813         if (!obj->id) {
 814                 obj->methods = &event_method;
 815                 obj->n_methods = 1;
 816
 817                 if (!!obj->name ^ !!obj->type)
 818                         return UBUS_STATUS_INVALID_ARGUMENT;
 819
 820                 ret = ubus_add_object(ctx, obj);
 821                 if (ret)
 822                         return ret;
 823         }
 824
 825         /* use a second buffer, ubus_invoke() overwrites the primary one */
 826         memset(&b2, 0, sizeof(b2));
 827         blob_buf_init(&b2, 0);
 828         blobmsg_add_u32(&b2, "object", obj->id);
 829         if (pattern)
 830                 blobmsg_add_string(&b2, "pattern", pattern);
 831
 832         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_EVENT, "register", b2.head,
 833                           NULL, NULL, 0);
 834 }
 835
 836 enum {
 837         WATCH_ID,
 838         WATCH_NOTIFY,
 839         __WATCH_MAX
 840 };
 841
 842 static const struct blobmsg_policy watch_policy[] = {
 843         [WATCH_ID] = { .name = "id", .type = BLOBMSG_TYPE_INT32 },
 844         [WATCH_NOTIFY] = { .name = "notify", .type = BLOBMSG_TYPE_STRING },
 845 };
 846
 847
 848 static int ubus_watch_cb(struct ubus_context *ctx, struct ubus_object *obj,
 849                          struct ubus_request_data *req,
 850                          const char *method, struct blob_attr *msg)
 851 {
 852         struct ubus_watch_object *w;
 853         struct blob_attr *tb[__WATCH_MAX];
 854
 855         blobmsg_parse(watch_policy, ARRAY_SIZE(watch_policy), tb, blob_data(msg), blob_len(msg));
 856
 857         if (!tb[WATCH_ID] || !tb[WATCH_NOTIFY])
 858                 return UBUS_STATUS_INVALID_ARGUMENT;
 859
 860         if (req->peer)
 861                 return UBUS_STATUS_INVALID_ARGUMENT;
 862
 863         w = container_of(obj, struct ubus_watch_object, obj);
 864         w->cb(ctx, w, blobmsg_get_u32(tb[WATCH_ID]));
 865         return 0;
 866 }
 867
 868 static const struct ubus_method watch_method = {
 869         .name = NULL,
 870         .handler = ubus_watch_cb,
 871 };
 872
 873 int ubus_register_watch_object(struct ubus_context *ctx, struct ubus_watch_object *w_obj)
 874 {
 875         struct ubus_object *obj = &w_obj->obj;
 876
 877         obj->methods = &watch_method;
 878         obj->n_methods = 1;
 879
 880         return ubus_add_object(ctx, obj);
 881 }
 882
 883 static int
 884 __ubus_watch_request(struct ubus_context *ctx, struct ubus_object *obj, uint32_t id, const char *method, int type)
 885 {
 886         struct ubus_request req;
 887
 888         blob_buf_init(&b, 0);
 889         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 890         blob_put_int32(&b, UBUS_ATTR_TARGET, id);
 891         if (method)
 892                 blob_put_string(&b, UBUS_ATTR_METHOD, method);
 893
 894         if (ubus_start_request(ctx, &req, b.head, type, 0) < 0)
 895                 return UBUS_STATUS_INVALID_ARGUMENT;
 896
 897         return ubus_complete_request(ctx, &req, 0);
 898
 899 }
 900
 901 int ubus_watch_object_add(struct ubus_context *ctx, struct ubus_watch_object *obj, uint32_t id)
 902 {
 903         return __ubus_watch_request(ctx, &obj->obj, id, "event", UBUS_MSG_ADD_WATCH);
 904 }
 905
 906 int ubus_watch_object_remove(struct ubus_context *ctx, struct ubus_watch_object *obj, uint32_t id)
 907 {
 908         return __ubus_watch_request(ctx, &obj->obj, id, NULL, UBUS_MSG_REMOVE_WATCH);
 909 }
 910
 911 int ubus_send_event(struct ubus_context *ctx, const char *id,
 912                     struct blob_attr *data)
 913 {
 914         struct ubus_request req;
 915         void *s;
 916
 917         blob_buf_init(&b, 0);
 918         blob_put_int32(&b, UBUS_ATTR_OBJID, UBUS_SYSTEM_OBJECT_EVENT);
 919         blob_put_string(&b, UBUS_ATTR_METHOD, "send");
 920         s = blob_nest_start(&b, UBUS_ATTR_DATA);
 921         blobmsg_add_string(&b, "id", id);
 922         blobmsg_add_field(&b, BLOBMSG_TYPE_TABLE, "data", blob_data(data), blob_len(data));
 923         blob_nest_end(&b, s);
 924
 925         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_INVOKE, UBUS_SYSTEM_OBJECT_EVENT) < 0)
 926                 return UBUS_STATUS_INVALID_ARGUMENT;
 927
 928         return ubus_complete_request(ctx, &req, 0);
 929 }
 930
 931 static void
 932 ubus_refresh_state(struct ubus_context *ctx)
 933 {
 934         struct ubus_object *obj, *tmp;
 935
 936         /* clear all type IDs, they need to be registered again */
 937         avl_for_each_element(&ctx->objects, obj, avl)
 938                 obj->type->id = 0;
 939
 940         /* push out all objects again */
 941         avl_for_each_element_safe(&ctx->objects, obj, avl, tmp) {
 942                 obj->id = 0;
 943                 avl_delete(&ctx->objects, &obj->avl);
 944                 ubus_add_object(ctx, obj);
 945         }
 946 }
 947
 948 int ubus_reconnect(struct ubus_context *ctx, const char *path)
 949 {
 950         struct {
 951                 struct ubus_msghdr hdr;
 952                 struct blob_attr data;
 953         } hdr;
 954         struct blob_attr *buf;
 955         int ret = UBUS_STATUS_UNKNOWN_ERROR;
 956
 957         if (!path)
 958                 path = UBUS_UNIX_SOCKET;
 959
 960         if (ctx->sock.fd >= 0) {
 961                 if (ctx->sock.registered)
 962                         uloop_fd_delete(&ctx->sock);
 963
 964                 close(ctx->sock.fd);
 965         }
 966
 967         ctx->sock.fd = usock(USOCK_UNIX, path, NULL);
 968         if (ctx->sock.fd < 0)
 969                 return UBUS_STATUS_CONNECTION_FAILED;
 970
 971         if (read(ctx->sock.fd, &hdr, sizeof(hdr)) != sizeof(hdr))
 972                 goto out_close;
 973
 974         if (!ubus_validate_hdr(&hdr.hdr))
 975                 goto out_close;
 976
 977         if (hdr.hdr.type != UBUS_MSG_HELLO)
 978                 goto out_close;
 979
 980         buf = calloc(1, blob_raw_len(&hdr.data));
 981         if (!buf)
 982                 goto out_close;
 983
 984         memcpy(buf, &hdr.data, sizeof(hdr.data));
 985         if (read(ctx->sock.fd, blob_data(buf), blob_len(buf)) != blob_len(buf))
 986                 goto out_free;
 987
 988         ctx->local_id = hdr.hdr.peer;
 989         if (!ctx->local_id)
 990                 goto out_free;
 991
 992         ret = UBUS_STATUS_OK;
 993         fcntl(ctx->sock.fd, F_SETFL, fcntl(ctx->sock.fd, F_GETFL) | O_NONBLOCK);
 994
 995         ubus_refresh_state(ctx);
 996
 997 out_free:
 998         free(buf);
 999 out_close:
1000         if (ret)
1001                 close(ctx->sock.fd);
1002
1003         return ret;
1004 }
1005
1006 static void ubus_default_connection_lost(struct ubus_context *ctx)
1007 {
1008         if (ctx->sock.registered)
1009                 uloop_end();
1010 }
1011
1012 struct ubus_context *ubus_connect(const char *path)
1013 {
1014         struct ubus_context *ctx;
1015
1016         ctx = calloc(1, sizeof(*ctx));
1017         if (!ctx)
1018                 return NULL;
1019
1020         ctx->sock.fd = -1;
1021         ctx->sock.cb = ubus_handle_data;
1022         ctx->connection_lost = ubus_default_connection_lost;
1023
1024         INIT_LIST_HEAD(&ctx->requests);
1025         INIT_LIST_HEAD(&ctx->pending);
1026         avl_init(&ctx->objects, ubus_cmp_id, false, NULL);
1027         if (ubus_reconnect(ctx, path)) {
1028                 free(ctx);
1029                 ctx = NULL;
1030         }
1031
1032         return ctx;
1033 }
1034
1035 void ubus_free(struct ubus_context *ctx)
1036 {
1037         close(ctx->sock.fd);
1038         free(ctx);
1039 }