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