libubus.c

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