libubus.c

   1 /*
   2  * Copyright (C) 2011-2012 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/socket.h>
  16 #include <unistd.h>
  17
  18 #include <libubox/blob.h>
  19 #include <libubox/blobmsg.h>
  20
  21 #include "libubus.h"
  22 #include "libubus-internal.h"
  23 #include "ubusmsg.h"
  24
  25 const char *__ubus_strerror[__UBUS_STATUS_LAST] = {
  26         [UBUS_STATUS_OK] = "Success",
  27         [UBUS_STATUS_INVALID_COMMAND] = "Invalid command",
  28         [UBUS_STATUS_INVALID_ARGUMENT] = "Invalid argument",
  29         [UBUS_STATUS_METHOD_NOT_FOUND] = "Method not found",
  30         [UBUS_STATUS_NOT_FOUND] = "Not found",
  31         [UBUS_STATUS_NO_DATA] = "No response",
  32         [UBUS_STATUS_PERMISSION_DENIED] = "Permission denied",
  33         [UBUS_STATUS_TIMEOUT] = "Request timed out",
  34         [UBUS_STATUS_NOT_SUPPORTED] = "Operation not supported",
  35         [UBUS_STATUS_UNKNOWN_ERROR] = "Unknown error",
  36         [UBUS_STATUS_CONNECTION_FAILED] = "Connection failed",
  37 };
  38
  39 struct blob_buf b __hidden = {};
  40
  41 struct ubus_pending_data {
  42         struct list_head list;
  43         int type;
  44         struct blob_attr data[];
  45 };
  46
  47 struct ubus_pending_invoke {
  48         struct list_head list;
  49         struct ubus_msghdr hdr;
  50 };
  51
  52 static void ubus_process_pending_invoke(struct ubus_context *ctx);
  53
  54 static int ubus_cmp_id(const void *k1, const void *k2, void *ptr)
  55 {
  56         const uint32_t *id1 = k1, *id2 = k2;
  57
  58         if (*id1 < *id2)
  59                 return -1;
  60         else
  61                 return *id1 > *id2;
  62 }
  63
  64 const char *ubus_strerror(int error)
  65 {
  66         static char err[32];
  67
  68         if (error < 0 || error >= __UBUS_STATUS_LAST)
  69                 goto out;
  70
  71         if (!__ubus_strerror[error])
  72                 goto out;
  73
  74         return __ubus_strerror[error];
  75
  76 out:
  77         sprintf(err, "Unknown error: %d", error);
  78         return err;
  79 }
  80
  81 static bool ubus_get_status(struct ubus_msghdr *hdr, int *ret)
  82 {
  83         struct blob_attr **attrbuf = ubus_parse_msg(hdr->data);
  84
  85         if (!attrbuf[UBUS_ATTR_STATUS])
  86                 return false;
  87
  88         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
  89         return true;
  90 }
  91
  92 static void req_data_cb(struct ubus_request *req, int type, struct blob_attr *data)
  93 {
  94         struct blob_attr **attr;
  95
  96         if (req->raw_data_cb)
  97                 req->raw_data_cb(req, type, data);
  98
  99         if (!req->data_cb)
 100                 return;
 101
 102         attr = ubus_parse_msg(data);
 103         req->data_cb(req, type, attr[UBUS_ATTR_DATA]);
 104 }
 105
 106 static void ubus_process_req_data(struct ubus_request *req)
 107 {
 108         struct ubus_pending_data *data;
 109
 110         while (!list_empty(&req->pending)) {
 111                 data = list_first_entry(&req->pending,
 112                         struct ubus_pending_data, list);
 113                 list_del(&data->list);
 114                 if (!req->cancelled)
 115                         req_data_cb(req, data->type, data->data);
 116                 free(data);
 117         }
 118 }
 119
 120 static void ubus_req_complete_cb(struct ubus_request *req)
 121 {
 122         ubus_complete_handler_t cb = req->complete_cb;
 123
 124         if (!cb)
 125                 return;
 126
 127         req->complete_cb = NULL;
 128         cb(req, req->status_code);
 129 }
 130
 131 static int ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr *hdr)
 132 {
 133         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 134
 135         if (!list_empty(&req->list))
 136                 list_del_init(&req->list);
 137
 138         ubus_get_status(hdr, &ret);
 139         req->peer = hdr->peer;
 140         req->status_msg = true;
 141         req->status_code = ret;
 142         if (!req->blocked)
 143                 ubus_req_complete_cb(req);
 144
 145         return ret;
 146 }
 147
 148 static void ubus_req_data(struct ubus_request *req, struct ubus_msghdr *hdr)
 149 {
 150         struct ubus_pending_data *data;
 151         int len;
 152
 153         if (!req->blocked) {
 154                 req->blocked = true;
 155                 req_data_cb(req, hdr->type, hdr->data);
 156                 ubus_process_req_data(req);
 157                 req->blocked = false;
 158
 159                 if (req->status_msg)
 160                         ubus_req_complete_cb(req);
 161
 162                 return;
 163         }
 164
 165         len = blob_raw_len(hdr->data);
 166         data = calloc(1, sizeof(*data) + len);
 167         if (!data)
 168                 return;
 169
 170         data->type = hdr->type;
 171         memcpy(data->data, hdr->data, len);
 172         list_add(&data->list, &req->pending);
 173 }
 174
 175 static struct ubus_request *ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer)
 176 {
 177         struct ubus_request *req;
 178
 179         list_for_each_entry(req, &ctx->requests, list) {
 180                 if (seq != req->seq || peer != req->peer)
 181                         continue;
 182
 183                 return req;
 184         }
 185         return NULL;
 186 }
 187
 188 void ubus_complete_deferred_request(struct ubus_context *ctx, struct ubus_request_data *req, int ret)
 189 {
 190         blob_buf_init(&b, 0);
 191         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 192         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 193         ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_STATUS, req->peer);
 194 }
 195
 196 void __hidden ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 197 {
 198         struct ubus_pending_invoke *pending;
 199         struct ubus_request *req;
 200
 201         switch(hdr->type) {
 202         case UBUS_MSG_STATUS:
 203                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 204                 if (!req)
 205                         break;
 206
 207                 ubus_process_req_status(req, hdr);
 208                 break;
 209
 210         case UBUS_MSG_DATA:
 211                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 212                 if (req && (req->data_cb || req->raw_data_cb))
 213                         ubus_req_data(req, hdr);
 214                 break;
 215
 216         case UBUS_MSG_INVOKE:
 217                 if (ctx->stack_depth > 2) {
 218                         pending = calloc(1, sizeof(*pending) +
 219                                 blob_raw_len(hdr->data));
 220
 221                         if (!pending)
 222                                 return;
 223
 224                         memcpy(&pending->hdr, hdr, sizeof(*hdr) +
 225                                 blob_raw_len(hdr->data));
 226                         list_add(&pending->list, &ctx->pending);
 227                 } else {
 228                         ubus_process_invoke(ctx, hdr);
 229                 }
 230                 break;
 231         }
 232 }
 233
 234 static void ubus_process_pending_invoke(struct ubus_context *ctx)
 235 {
 236         struct ubus_pending_invoke *pending, *tmp;
 237
 238         list_for_each_entry_safe(pending, tmp, &ctx->pending, list) {
 239                 list_del(&pending->list);
 240                 ubus_process_msg(ctx, &pending->hdr);
 241                 free(pending);
 242                 if (ctx->stack_depth > 2)
 243                         break;
 244         }
 245 }
 246
 247 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
 248 {
 249         if (!list_empty(&req->list))
 250                 return;
 251
 252         req->cancelled = true;
 253         ubus_process_req_data(req);
 254         list_del_init(&req->list);
 255 }
 256
 257 void ubus_complete_request_async(struct ubus_context *ctx, struct ubus_request *req)
 258 {
 259         if (!list_empty(&req->list))
 260                 return;
 261
 262         list_add(&req->list, &ctx->requests);
 263 }
 264
 265 static void ubus_sync_req_cb(struct ubus_request *req, int ret)
 266 {
 267         req->status_msg = true;
 268         req->status_code = ret;
 269         uloop_end();
 270 }
 271
 272 struct ubus_sync_req_cb {
 273         struct uloop_timeout timeout;
 274         struct ubus_request *req;
 275 };
 276
 277 static void ubus_sync_req_timeout_cb(struct uloop_timeout *timeout)
 278 {
 279         struct ubus_sync_req_cb *cb;
 280
 281         cb = container_of(timeout, struct ubus_sync_req_cb, timeout);
 282         ubus_sync_req_cb(cb->req, UBUS_STATUS_TIMEOUT);
 283 }
 284
 285 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 286                           int timeout)
 287 {
 288         struct ubus_sync_req_cb cb;
 289         ubus_complete_handler_t complete_cb = req->complete_cb;
 290         bool registered = ctx->sock.registered;
 291         int status = UBUS_STATUS_NO_DATA;
 292
 293         if (!registered) {
 294                 uloop_init();
 295                 ubus_add_uloop(ctx);
 296         }
 297
 298         if (timeout) {
 299                 memset(&cb, 0, sizeof(cb));
 300                 cb.req = req;
 301                 cb.timeout.cb = ubus_sync_req_timeout_cb;
 302                 uloop_timeout_set(&cb.timeout, timeout);
 303         }
 304
 305         ubus_complete_request_async(ctx, req);
 306         req->complete_cb = ubus_sync_req_cb;
 307
 308         ctx->stack_depth++;
 309         while (!req->status_msg) {
 310                 bool cancelled = uloop_cancelled;
 311                 uloop_cancelled = false;
 312                 uloop_run();
 313                 uloop_cancelled = cancelled;
 314         }
 315         ctx->stack_depth--;
 316
 317         if (timeout)
 318                 uloop_timeout_cancel(&cb.timeout);
 319
 320         if (req->status_msg)
 321                 status = req->status_code;
 322
 323         req->complete_cb = complete_cb;
 324         if (req->complete_cb)
 325                 req->complete_cb(req, status);
 326
 327         if (!registered)
 328                 uloop_fd_delete(&ctx->sock);
 329
 330         if (!ctx->stack_depth)
 331                 ubus_process_pending_invoke(ctx);
 332
 333         return status;
 334 }
 335
 336 struct ubus_lookup_request {
 337         struct ubus_request req;
 338         ubus_lookup_handler_t cb;
 339 };
 340
 341 static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr *msg)
 342 {
 343         struct ubus_lookup_request *req;
 344         struct ubus_object_data obj;
 345         struct blob_attr **attr;
 346
 347         req = container_of(ureq, struct ubus_lookup_request, req);
 348         attr = ubus_parse_msg(msg);
 349
 350         if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_OBJPATH] ||
 351             !attr[UBUS_ATTR_OBJTYPE])
 352                 return;
 353
 354         memset(&obj, 0, sizeof(obj));
 355         obj.id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 356         obj.path = blob_data(attr[UBUS_ATTR_OBJPATH]);
 357         obj.type_id = blob_get_u32(attr[UBUS_ATTR_OBJTYPE]);
 358         obj.signature = attr[UBUS_ATTR_SIGNATURE];
 359         req->cb(ureq->ctx, &obj, ureq->priv);
 360 }
 361
 362 int __hidden ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
 363                                 struct blob_attr *msg, int cmd, uint32_t peer)
 364 {
 365         memset(req, 0, sizeof(*req));
 366
 367         if (msg && blob_pad_len(msg) > UBUS_MAX_MSGLEN)
 368                 return -1;
 369
 370         INIT_LIST_HEAD(&req->list);
 371         INIT_LIST_HEAD(&req->pending);
 372         req->ctx = ctx;
 373         req->peer = peer;
 374         req->seq = ++ctx->request_seq;
 375         return ubus_send_msg(ctx, req->seq, msg, cmd, peer);
 376 }
 377
 378 int ubus_lookup(struct ubus_context *ctx, const char *path,
 379                 ubus_lookup_handler_t cb, void *priv)
 380 {
 381         struct ubus_lookup_request lookup;
 382
 383         blob_buf_init(&b, 0);
 384         if (path)
 385                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 386
 387         if (ubus_start_request(ctx, &lookup.req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 388                 return UBUS_STATUS_INVALID_ARGUMENT;
 389
 390         lookup.req.raw_data_cb = ubus_lookup_cb;
 391         lookup.req.priv = priv;
 392         lookup.cb = cb;
 393         return ubus_complete_request(ctx, &lookup.req, 0);
 394 }
 395
 396 static void ubus_lookup_id_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 397 {
 398         struct blob_attr **attr;
 399         uint32_t *id = req->priv;
 400
 401         attr = ubus_parse_msg(msg);
 402
 403         if (!attr[UBUS_ATTR_OBJID])
 404                 return;
 405
 406         *id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 407 }
 408
 409 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id)
 410 {
 411         struct ubus_request req;
 412
 413         blob_buf_init(&b, 0);
 414         if (path)
 415                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 416
 417         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 418                 return UBUS_STATUS_INVALID_ARGUMENT;
 419
 420         req.raw_data_cb = ubus_lookup_id_cb;
 421         req.priv = id;
 422
 423         return ubus_complete_request(ctx, &req, 0);
 424 }
 425
 426 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 427                     struct blob_attr *msg)
 428 {
 429         int ret;
 430
 431         blob_buf_init(&b, 0);
 432         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 433         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 434         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer);
 435         if (ret < 0)
 436                 return UBUS_STATUS_NO_DATA;
 437
 438         return 0;
 439 }
 440
 441 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 442                        struct blob_attr *msg, struct ubus_request *req)
 443 {
 444         blob_buf_init(&b, 0);
 445         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 446         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 447         if (msg)
 448                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 449
 450         if (ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 451                 return UBUS_STATUS_INVALID_ARGUMENT;
 452
 453         return 0;
 454 }
 455
 456 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 457                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 458                 int timeout)
 459 {
 460         struct ubus_request req;
 461
 462         ubus_invoke_async(ctx, obj, method, msg, &req);
 463         req.data_cb = cb;
 464         req.priv = priv;
 465         return ubus_complete_request(ctx, &req, timeout);
 466 }
 467
 468
 469
 470 static int ubus_event_cb(struct ubus_context *ctx, struct ubus_object *obj,
 471                          struct ubus_request_data *req,
 472                          const char *method, struct blob_attr *msg)
 473 {
 474         struct ubus_event_handler *ev;
 475
 476         ev = container_of(obj, struct ubus_event_handler, obj);
 477         ev->cb(ctx, ev, method, msg);
 478         return 0;
 479 }
 480
 481 static const struct ubus_method event_method = {
 482         .name = NULL,
 483         .handler = ubus_event_cb,
 484 };
 485
 486 int ubus_register_event_handler(struct ubus_context *ctx,
 487                                 struct ubus_event_handler *ev,
 488                                 const char *pattern)
 489 {
 490         struct ubus_object *obj = &ev->obj;
 491         struct blob_buf b2;
 492         int ret;
 493
 494         if (!obj->id) {
 495                 obj->methods = &event_method;
 496                 obj->n_methods = 1;
 497
 498                 if (!!obj->name ^ !!obj->type)
 499                         return UBUS_STATUS_INVALID_ARGUMENT;
 500
 501                 ret = ubus_add_object(ctx, obj);
 502                 if (ret)
 503                         return ret;
 504         }
 505
 506         /* use a second buffer, ubus_invoke() overwrites the primary one */
 507         memset(&b2, 0, sizeof(b2));
 508         blob_buf_init(&b2, 0);
 509         blobmsg_add_u32(&b2, "object", obj->id);
 510         if (pattern)
 511                 blobmsg_add_string(&b2, "pattern", pattern);
 512
 513         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_EVENT, "register", b2.head,
 514                           NULL, NULL, 0);
 515 }
 516
 517 enum {
 518         WATCH_ID,
 519         WATCH_NOTIFY,
 520         __WATCH_MAX
 521 };
 522
 523 static const struct blobmsg_policy watch_policy[] = {
 524         [WATCH_ID] = { .name = "id", .type = BLOBMSG_TYPE_INT32 },
 525         [WATCH_NOTIFY] = { .name = "notify", .type = BLOBMSG_TYPE_STRING },
 526 };
 527
 528
 529 static int ubus_watch_cb(struct ubus_context *ctx, struct ubus_object *obj,
 530                          struct ubus_request_data *req,
 531                          const char *method, struct blob_attr *msg)
 532 {
 533         struct ubus_watch_object *w;
 534         struct blob_attr *tb[__WATCH_MAX];
 535
 536         blobmsg_parse(watch_policy, ARRAY_SIZE(watch_policy), tb, blob_data(msg), blob_len(msg));
 537
 538         if (!tb[WATCH_ID] || !tb[WATCH_NOTIFY])
 539                 return UBUS_STATUS_INVALID_ARGUMENT;
 540
 541         if (req->peer)
 542                 return UBUS_STATUS_INVALID_ARGUMENT;
 543
 544         w = container_of(obj, struct ubus_watch_object, obj);
 545         w->cb(ctx, w, blobmsg_get_u32(tb[WATCH_ID]));
 546         return 0;
 547 }
 548
 549 static const struct ubus_method watch_method = {
 550         .name = NULL,
 551         .handler = ubus_watch_cb,
 552 };
 553
 554 int ubus_register_watch_object(struct ubus_context *ctx, struct ubus_watch_object *w_obj)
 555 {
 556         struct ubus_object *obj = &w_obj->obj;
 557
 558         obj->methods = &watch_method;
 559         obj->n_methods = 1;
 560
 561         return ubus_add_object(ctx, obj);
 562 }
 563
 564 static int
 565 __ubus_watch_request(struct ubus_context *ctx, struct ubus_object *obj, uint32_t id, const char *method, int type)
 566 {
 567         struct ubus_request req;
 568
 569         blob_buf_init(&b, 0);
 570         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 571         blob_put_int32(&b, UBUS_ATTR_TARGET, id);
 572         if (method)
 573                 blob_put_string(&b, UBUS_ATTR_METHOD, method);
 574
 575         if (ubus_start_request(ctx, &req, b.head, type, 0) < 0)
 576                 return UBUS_STATUS_INVALID_ARGUMENT;
 577
 578         return ubus_complete_request(ctx, &req, 0);
 579
 580 }
 581
 582 int ubus_watch_object_add(struct ubus_context *ctx, struct ubus_watch_object *obj, uint32_t id)
 583 {
 584         return __ubus_watch_request(ctx, &obj->obj, id, "event", UBUS_MSG_ADD_WATCH);
 585 }
 586
 587 int ubus_watch_object_remove(struct ubus_context *ctx, struct ubus_watch_object *obj, uint32_t id)
 588 {
 589         return __ubus_watch_request(ctx, &obj->obj, id, NULL, UBUS_MSG_REMOVE_WATCH);
 590 }
 591
 592 int ubus_send_event(struct ubus_context *ctx, const char *id,
 593                     struct blob_attr *data)
 594 {
 595         struct ubus_request req;
 596         void *s;
 597
 598         blob_buf_init(&b, 0);
 599         blob_put_int32(&b, UBUS_ATTR_OBJID, UBUS_SYSTEM_OBJECT_EVENT);
 600         blob_put_string(&b, UBUS_ATTR_METHOD, "send");
 601         s = blob_nest_start(&b, UBUS_ATTR_DATA);
 602         blobmsg_add_string(&b, "id", id);
 603         blobmsg_add_field(&b, BLOBMSG_TYPE_TABLE, "data", blob_data(data), blob_len(data));
 604         blob_nest_end(&b, s);
 605
 606         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_INVOKE, UBUS_SYSTEM_OBJECT_EVENT) < 0)
 607                 return UBUS_STATUS_INVALID_ARGUMENT;
 608
 609         return ubus_complete_request(ctx, &req, 0);
 610 }
 611
 612 static void ubus_default_connection_lost(struct ubus_context *ctx)
 613 {
 614         if (ctx->sock.registered)
 615                 uloop_end();
 616 }
 617
 618 struct ubus_context *ubus_connect(const char *path)
 619 {
 620         struct ubus_context *ctx;
 621
 622         ctx = calloc(1, sizeof(*ctx));
 623         if (!ctx)
 624                 return NULL;
 625
 626         ctx->sock.fd = -1;
 627         ctx->sock.cb = ubus_handle_data;
 628         ctx->connection_lost = ubus_default_connection_lost;
 629
 630         INIT_LIST_HEAD(&ctx->requests);
 631         INIT_LIST_HEAD(&ctx->pending);
 632         avl_init(&ctx->objects, ubus_cmp_id, false, NULL);
 633         if (ubus_reconnect(ctx, path)) {
 634                 free(ctx);
 635                 ctx = NULL;
 636         }
 637
 638         return ctx;
 639 }
 640
 641 void ubus_free(struct ubus_context *ctx)
 642 {
 643         close(ctx->sock.fd);
 644         free(ctx);
 645 }