ubusd_proto.c

   1 /*
   2  * Copyright (C) 2011-2014 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 <arpa/inet.h>
  15 #include <unistd.h>
  16
  17 #include "ubusd.h"
  18
  19 struct blob_buf b;
  20 static struct avl_tree clients;
  21
  22 static struct blob_attr *attrbuf[UBUS_ATTR_MAX];
  23
  24 typedef int (*ubus_cmd_cb)(struct ubus_client *cl, struct ubus_msg_buf *ub, struct blob_attr **attr);
  25
  26 static const struct blob_attr_info ubus_policy[UBUS_ATTR_MAX] = {
  27         [UBUS_ATTR_SIGNATURE] = { .type = BLOB_ATTR_NESTED },
  28         [UBUS_ATTR_OBJTYPE] = { .type = BLOB_ATTR_INT32 },
  29         [UBUS_ATTR_OBJPATH] = { .type = BLOB_ATTR_STRING },
  30         [UBUS_ATTR_OBJID] = { .type = BLOB_ATTR_INT32 },
  31         [UBUS_ATTR_STATUS] = { .type = BLOB_ATTR_INT32 },
  32         [UBUS_ATTR_METHOD] = { .type = BLOB_ATTR_STRING },
  33         [UBUS_ATTR_USER] = { .type = BLOB_ATTR_STRING },
  34         [UBUS_ATTR_GROUP] = { .type = BLOB_ATTR_STRING },
  35 };
  36
  37 struct blob_attr **ubus_parse_msg(struct blob_attr *msg, size_t len)
  38 {
  39         blob_parse_untrusted(msg, len, attrbuf, ubus_policy, UBUS_ATTR_MAX);
  40         return attrbuf;
  41 }
  42
  43 static void ubus_msg_close_fd(struct ubus_msg_buf *ub)
  44 {
  45         if (ub->fd < 0)
  46                 return;
  47
  48         close(ub->fd);
  49         ub->fd = -1;
  50 }
  51
  52 static void ubus_msg_init(struct ubus_msg_buf *ub, uint8_t type, uint16_t seq, uint32_t peer)
  53 {
  54         ub->hdr.version = 0;
  55         ub->hdr.type = type;
  56         ub->hdr.seq = seq;
  57         ub->hdr.peer = peer;
  58 }
  59
  60 static struct ubus_msg_buf *ubus_msg_from_blob(bool shared)
  61 {
  62         return ubus_msg_new(b.head, blob_raw_len(b.head), shared);
  63 }
  64
  65 static struct ubus_msg_buf *ubus_reply_from_blob(struct ubus_msg_buf *ub, bool shared)
  66 {
  67         struct ubus_msg_buf *new;
  68
  69         new = ubus_msg_from_blob(shared);
  70         if (!new)
  71                 return NULL;
  72
  73         ubus_msg_init(new, UBUS_MSG_DATA, ub->hdr.seq, ub->hdr.peer);
  74         return new;
  75 }
  76
  77 void
  78 ubus_proto_send_msg_from_blob(struct ubus_client *cl, struct ubus_msg_buf *ub,
  79                         uint8_t type)
  80 {
  81         /* keep the fd to be passed if it is UBUS_MSG_INVOKE */
  82         int fd = ub->fd;
  83         ub = ubus_reply_from_blob(ub, true);
  84         if (!ub)
  85                 return;
  86
  87         ub->hdr.type = type;
  88         ub->fd = fd;
  89
  90         ubus_msg_send(cl, ub);
  91         ubus_msg_free(ub);
  92 }
  93
  94 static bool ubusd_send_hello(struct ubus_client *cl)
  95 {
  96         struct ubus_msg_buf *ub;
  97
  98         blob_buf_init(&b, 0);
  99         ub = ubus_msg_from_blob(true);
 100         if (!ub)
 101                 return false;
 102
 103         ubus_msg_init(ub, UBUS_MSG_HELLO, 0, cl->id.id);
 104         ubus_msg_send(cl, ub);
 105         ubus_msg_free(ub);
 106         return true;
 107 }
 108
 109 static int ubusd_send_pong(struct ubus_client *cl, struct ubus_msg_buf *ub, struct blob_attr **attr)
 110 {
 111         ub->hdr.type = UBUS_MSG_DATA;
 112         ubus_msg_send(cl, ub);
 113         return 0;
 114 }
 115
 116 static int ubusd_handle_remove_object(struct ubus_client *cl, struct ubus_msg_buf *ub, struct blob_attr **attr)
 117 {
 118         struct ubus_object *obj;
 119
 120         if (!attr[UBUS_ATTR_OBJID])
 121                 return UBUS_STATUS_INVALID_ARGUMENT;
 122
 123         obj = ubusd_find_object(blob_get_u32(attr[UBUS_ATTR_OBJID]));
 124         if (!obj)
 125                 return UBUS_STATUS_NOT_FOUND;
 126
 127         if (obj->client != cl)
 128                 return UBUS_STATUS_PERMISSION_DENIED;
 129
 130         blob_buf_init(&b, 0);
 131         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id.id);
 132
 133         /* check if we're removing the object type as well */
 134         if (obj->type && obj->type->refcount == 1)
 135                 blob_put_int32(&b, UBUS_ATTR_OBJTYPE, obj->type->id.id);
 136
 137         ubus_proto_send_msg_from_blob(cl, ub, UBUS_MSG_DATA);
 138         ubusd_free_object(obj);
 139
 140         return 0;
 141 }
 142
 143 static int ubusd_handle_add_object(struct ubus_client *cl, struct ubus_msg_buf *ub, struct blob_attr **attr)
 144 {
 145         struct ubus_object *obj;
 146
 147         obj = ubusd_create_object(cl, attr);
 148         if (!obj)
 149                 return UBUS_STATUS_INVALID_ARGUMENT;
 150
 151         blob_buf_init(&b, 0);
 152         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id.id);
 153         if (attr[UBUS_ATTR_SIGNATURE] && obj->type)
 154                 blob_put_int32(&b, UBUS_ATTR_OBJTYPE, obj->type->id.id);
 155
 156         ubus_proto_send_msg_from_blob(cl, ub, UBUS_MSG_DATA);
 157         return 0;
 158 }
 159
 160 static void ubusd_send_obj(struct ubus_client *cl, struct ubus_msg_buf *ub, struct ubus_object *obj)
 161 {
 162         struct ubus_method *m;
 163         int all_cnt = 0, cnt = 0;
 164         void *s;
 165
 166         if (!obj->type)
 167                 return;
 168
 169         blob_buf_init(&b, 0);
 170
 171         blob_put_string(&b, UBUS_ATTR_OBJPATH, obj->path.key);
 172         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id.id);
 173         blob_put_int32(&b, UBUS_ATTR_OBJTYPE, obj->type->id.id);
 174
 175         s = blob_nest_start(&b, UBUS_ATTR_SIGNATURE);
 176         list_for_each_entry(m, &obj->type->methods, list) {
 177                 all_cnt++;
 178                 if (!ubusd_acl_check(cl, obj->path.key, blobmsg_name(m->data), UBUS_ACL_ACCESS)) {
 179                         blobmsg_add_blob(&b, m->data);
 180                         cnt++;
 181                 }
 182         }
 183         blob_nest_end(&b, s);
 184
 185         if (cnt || !all_cnt)
 186                 ubus_proto_send_msg_from_blob(cl, ub, UBUS_MSG_DATA);
 187 }
 188
 189 static int ubusd_handle_lookup(struct ubus_client *cl, struct ubus_msg_buf *ub, struct blob_attr **attr)
 190 {
 191         struct ubus_object *obj;
 192         char *objpath;
 193         bool found = false;
 194         int len;
 195
 196         if (!attr[UBUS_ATTR_OBJPATH]) {
 197                 avl_for_each_element(&path, obj, path)
 198                         ubusd_send_obj(cl, ub, obj);
 199                 return 0;
 200         }
 201
 202         objpath = blob_data(attr[UBUS_ATTR_OBJPATH]);
 203         len = strlen(objpath);
 204         if (objpath[len - 1] != '*') {
 205                 obj = avl_find_element(&path, objpath, obj, path);
 206                 if (!obj)
 207                         return UBUS_STATUS_NOT_FOUND;
 208
 209                 ubusd_send_obj(cl, ub, obj);
 210                 return 0;
 211         }
 212
 213         objpath[--len] = 0;
 214
 215         obj = avl_find_ge_element(&path, objpath, obj, path);
 216         if (!obj)
 217                 return UBUS_STATUS_NOT_FOUND;
 218
 219         while (!strncmp(objpath, obj->path.key, len)) {
 220                 found = true;
 221                 ubusd_send_obj(cl, ub, obj);
 222                 if (obj == avl_last_element(&path, obj, path))
 223                         break;
 224                 obj = avl_next_element(obj, path);
 225         }
 226
 227         if (!found)
 228                 return UBUS_STATUS_NOT_FOUND;
 229
 230         return 0;
 231 }
 232
 233 static void
 234 ubusd_forward_invoke(struct ubus_client *cl, struct ubus_object *obj,
 235                      const char *method, struct ubus_msg_buf *ub,
 236                      struct blob_attr *data)
 237 {
 238         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id.id);
 239         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 240         if (cl->user)
 241                 blob_put_string(&b, UBUS_ATTR_USER, cl->user);
 242         if (cl->group)
 243                 blob_put_string(&b, UBUS_ATTR_GROUP, cl->group);
 244         if (data)
 245                 blob_put(&b, UBUS_ATTR_DATA, blob_data(data), blob_len(data));
 246
 247         ubus_proto_send_msg_from_blob(obj->client, ub, UBUS_MSG_INVOKE);
 248 }
 249
 250 static int ubusd_handle_invoke(struct ubus_client *cl, struct ubus_msg_buf *ub, struct blob_attr **attr)
 251 {
 252         struct ubus_object *obj = NULL;
 253         struct ubus_id *id;
 254         const char *method;
 255
 256         if (!attr[UBUS_ATTR_METHOD] || !attr[UBUS_ATTR_OBJID])
 257                 return UBUS_STATUS_INVALID_ARGUMENT;
 258
 259         id = ubus_find_id(&objects, blob_get_u32(attr[UBUS_ATTR_OBJID]));
 260         if (!id)
 261                 return UBUS_STATUS_NOT_FOUND;
 262
 263         obj = container_of(id, struct ubus_object, id);
 264
 265         method = blob_data(attr[UBUS_ATTR_METHOD]);
 266
 267         if (ubusd_acl_check(cl, obj->path.key, method, UBUS_ACL_ACCESS))
 268                 return UBUS_STATUS_PERMISSION_DENIED;
 269
 270         if (!obj->client)
 271                 return obj->recv_msg(cl, ub, method, attr[UBUS_ATTR_DATA]);
 272
 273         ub->hdr.peer = cl->id.id;
 274         blob_buf_init(&b, 0);
 275
 276         ubusd_forward_invoke(cl, obj, method, ub, attr[UBUS_ATTR_DATA]);
 277
 278         return -1;
 279 }
 280
 281 static int ubusd_handle_notify(struct ubus_client *cl, struct ubus_msg_buf *ub, struct blob_attr **attr)
 282 {
 283         struct ubus_object *obj = NULL;
 284         struct ubus_subscription *s;
 285         struct ubus_id *id;
 286         const char *method;
 287         bool no_reply = false;
 288         void *c;
 289
 290         if (!attr[UBUS_ATTR_METHOD] || !attr[UBUS_ATTR_OBJID])
 291                 return UBUS_STATUS_INVALID_ARGUMENT;
 292
 293         if (attr[UBUS_ATTR_NO_REPLY])
 294                 no_reply = blob_get_int8(attr[UBUS_ATTR_NO_REPLY]);
 295
 296         id = ubus_find_id(&objects, blob_get_u32(attr[UBUS_ATTR_OBJID]));
 297         if (!id)
 298                 return UBUS_STATUS_NOT_FOUND;
 299
 300         obj = container_of(id, struct ubus_object, id);
 301         if (obj->client != cl)
 302                 return UBUS_STATUS_PERMISSION_DENIED;
 303
 304         if (!no_reply) {
 305                 blob_buf_init(&b, 0);
 306                 blob_put_int32(&b, UBUS_ATTR_OBJID, id->id);
 307                 c = blob_nest_start(&b, UBUS_ATTR_SUBSCRIBERS);
 308                 list_for_each_entry(s, &obj->subscribers, list) {
 309                         blob_put_int32(&b, 0, s->subscriber->id.id);
 310                 }
 311                 blob_nest_end(&b, c);
 312                 blob_put_int32(&b, UBUS_ATTR_STATUS, 0);
 313                 ubus_proto_send_msg_from_blob(cl, ub, UBUS_MSG_STATUS);
 314         }
 315
 316         ub->hdr.peer = cl->id.id;
 317         method = blob_data(attr[UBUS_ATTR_METHOD]);
 318         list_for_each_entry(s, &obj->subscribers, list) {
 319                 blob_buf_init(&b, 0);
 320                 if (no_reply)
 321                         blob_put_int8(&b, UBUS_ATTR_NO_REPLY, 1);
 322                 ubusd_forward_invoke(cl, s->subscriber, method, ub, attr[UBUS_ATTR_DATA]);
 323         }
 324
 325         return -1;
 326 }
 327
 328 static struct ubus_client *ubusd_get_client_by_id(uint32_t id)
 329 {
 330         struct ubus_id *clid;
 331
 332         clid = ubus_find_id(&clients, id);
 333         if (!clid)
 334                 return NULL;
 335
 336         return container_of(clid, struct ubus_client, id);
 337 }
 338
 339 static int ubusd_handle_response(struct ubus_client *cl, struct ubus_msg_buf *ub, struct blob_attr **attr)
 340 {
 341         struct ubus_object *obj;
 342
 343         if (!attr[UBUS_ATTR_OBJID] ||
 344             (ub->hdr.type == UBUS_MSG_STATUS && !attr[UBUS_ATTR_STATUS]) ||
 345             (ub->hdr.type == UBUS_MSG_DATA && !attr[UBUS_ATTR_DATA]))
 346                 goto out;
 347
 348         obj = ubusd_find_object(blob_get_u32(attr[UBUS_ATTR_OBJID]));
 349         if (!obj)
 350                 goto out;
 351
 352         if (cl != obj->client)
 353                 goto out;
 354
 355         cl = ubusd_get_client_by_id(ub->hdr.peer);
 356         if (!cl)
 357                 goto out;
 358
 359         ub->hdr.peer = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 360         ubus_msg_send(cl, ub);
 361 out:
 362         return -1;
 363 }
 364
 365 static int ubusd_handle_add_watch(struct ubus_client *cl, struct ubus_msg_buf *ub, struct blob_attr **attr)
 366 {
 367         struct ubus_object *obj, *target;
 368
 369         if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_TARGET])
 370                 return UBUS_STATUS_INVALID_ARGUMENT;
 371
 372         obj = ubusd_find_object(blob_get_u32(attr[UBUS_ATTR_OBJID]));
 373         if (!obj)
 374                 return UBUS_STATUS_NOT_FOUND;
 375
 376         if (cl != obj->client)
 377                 return UBUS_STATUS_INVALID_ARGUMENT;
 378
 379         target = ubusd_find_object(blob_get_u32(attr[UBUS_ATTR_TARGET]));
 380         if (!target || !target->client)
 381                 return UBUS_STATUS_NOT_FOUND;
 382
 383         if (cl == target->client)
 384                 return UBUS_STATUS_INVALID_ARGUMENT;
 385
 386         if (!target->path.key) {
 387                 if (strcmp(target->client->user, cl->user) && strcmp(target->client->group, cl->group))
 388                         return UBUS_STATUS_NOT_FOUND;
 389         } else if (ubusd_acl_check(cl, target->path.key, NULL, UBUS_ACL_SUBSCRIBE)) {
 390                 return UBUS_STATUS_NOT_FOUND;
 391         }
 392
 393         ubus_subscribe(obj, target);
 394         return 0;
 395 }
 396
 397 static int ubusd_handle_remove_watch(struct ubus_client *cl, struct ubus_msg_buf *ub, struct blob_attr **attr)
 398 {
 399         struct ubus_object *obj;
 400         struct ubus_subscription *s;
 401         uint32_t id;
 402
 403         if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_TARGET])
 404                 return UBUS_STATUS_INVALID_ARGUMENT;
 405
 406         obj = ubusd_find_object(blob_get_u32(attr[UBUS_ATTR_OBJID]));
 407         if (!obj)
 408                 return UBUS_STATUS_NOT_FOUND;
 409
 410         if (cl != obj->client)
 411                 return UBUS_STATUS_INVALID_ARGUMENT;
 412
 413         id = blob_get_u32(attr[UBUS_ATTR_TARGET]);
 414         list_for_each_entry(s, &obj->target_list, target_list) {
 415                 if (s->target->id.id != id)
 416                         continue;
 417
 418                 ubus_unsubscribe(s);
 419                 return 0;
 420         }
 421
 422         return UBUS_STATUS_NOT_FOUND;
 423 }
 424
 425 static const ubus_cmd_cb handlers[__UBUS_MSG_LAST] = {
 426         [UBUS_MSG_PING] = ubusd_send_pong,
 427         [UBUS_MSG_ADD_OBJECT] = ubusd_handle_add_object,
 428         [UBUS_MSG_REMOVE_OBJECT] = ubusd_handle_remove_object,
 429         [UBUS_MSG_LOOKUP] = ubusd_handle_lookup,
 430         [UBUS_MSG_INVOKE] = ubusd_handle_invoke,
 431         [UBUS_MSG_STATUS] = ubusd_handle_response,
 432         [UBUS_MSG_DATA] = ubusd_handle_response,
 433         [UBUS_MSG_SUBSCRIBE] = ubusd_handle_add_watch,
 434         [UBUS_MSG_UNSUBSCRIBE] = ubusd_handle_remove_watch,
 435         [UBUS_MSG_NOTIFY] = ubusd_handle_notify,
 436 };
 437
 438 void ubusd_proto_receive_message(struct ubus_client *cl, struct ubus_msg_buf *ub)
 439 {
 440         ubus_cmd_cb cb = NULL;
 441         int ret;
 442         struct ubus_msg_buf *retmsg = cl->retmsg;
 443         int *retmsg_data = blob_data(blob_data(retmsg->data));
 444
 445         retmsg->hdr.seq = ub->hdr.seq;
 446         retmsg->hdr.peer = ub->hdr.peer;
 447
 448         if (ub->hdr.type < __UBUS_MSG_LAST)
 449                 cb = handlers[ub->hdr.type];
 450
 451         if (ub->hdr.type != UBUS_MSG_STATUS && ub->hdr.type != UBUS_MSG_INVOKE)
 452                 ubus_msg_close_fd(ub);
 453
 454         /* Note: no callback should free the `ub` buffer
 455                  that's always done right after the callback finishes */
 456         if (cb)
 457                 ret = cb(cl, ub, ubus_parse_msg(ub->data, blob_raw_len(ub->data)));
 458         else
 459                 ret = UBUS_STATUS_INVALID_COMMAND;
 460
 461         ubus_msg_free(ub);
 462
 463         if (ret == -1)
 464                 return;
 465
 466         *retmsg_data = htonl(ret);
 467         ubus_msg_send(cl, retmsg);
 468 }
 469
 470 static int ubusd_proto_init_retmsg(struct ubus_client *cl)
 471 {
 472         struct blob_buf *b = &cl->b;
 473
 474         blob_buf_init(&cl->b, 0);
 475         blob_put_int32(&cl->b, UBUS_ATTR_STATUS, 0);
 476
 477         /* we make the 'retmsg' buffer shared with the blob_buf b, to reduce mem duplication */
 478         cl->retmsg = ubus_msg_new(b->head, blob_raw_len(b->head), true);
 479         if (!cl->retmsg)
 480                 return -1;
 481
 482         cl->retmsg->hdr.type = UBUS_MSG_STATUS;
 483         return 0;
 484 }
 485
 486 struct ubus_client *ubusd_proto_new_client(int fd, uloop_fd_handler cb)
 487 {
 488         struct ubus_client *cl;
 489
 490         cl = calloc(1, sizeof(*cl));
 491         if (!cl)
 492                 return NULL;
 493
 494         if (ubusd_acl_init_client(cl, fd))
 495                 goto free;
 496
 497         INIT_LIST_HEAD(&cl->objects);
 498         INIT_LIST_HEAD(&cl->tx_queue);
 499         cl->sock.fd = fd;
 500         cl->sock.cb = cb;
 501         cl->pending_msg_fd = -1;
 502
 503         if (!ubus_alloc_id(&clients, &cl->id, 0))
 504                 goto free;
 505
 506         if (ubusd_proto_init_retmsg(cl))
 507                 goto free;
 508
 509         if (!ubusd_send_hello(cl))
 510                 goto delete;
 511
 512         return cl;
 513
 514 delete:
 515         ubus_free_id(&clients, &cl->id);
 516 free:
 517         free(cl);
 518         return NULL;
 519 }
 520
 521 void ubusd_proto_free_client(struct ubus_client *cl)
 522 {
 523         struct ubus_object *obj, *tmp;
 524
 525         list_for_each_entry_safe(obj, tmp, &cl->objects, list) {
 526                 ubusd_free_object(obj);
 527         }
 528
 529         ubus_msg_free(cl->retmsg);
 530         blob_buf_free(&cl->b);
 531
 532         ubusd_acl_free_client(cl);
 533         ubus_free_id(&clients, &cl->id);
 534 }
 535
 536 void ubus_notify_subscription(struct ubus_object *obj)
 537 {
 538         bool active = !list_empty(&obj->subscribers);
 539         struct ubus_msg_buf *ub;
 540
 541         blob_buf_init(&b, 0);
 542         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id.id);
 543         blob_put_int8(&b, UBUS_ATTR_ACTIVE, active);
 544
 545         ub = ubus_msg_from_blob(false);
 546         if (!ub)
 547                 return;
 548
 549         ubus_msg_init(ub, UBUS_MSG_NOTIFY, ++obj->invoke_seq, 0);
 550         ubus_msg_send(obj->client, ub);
 551         ubus_msg_free(ub);
 552 }
 553
 554 void ubus_notify_unsubscribe(struct ubus_subscription *s)
 555 {
 556         struct ubus_msg_buf *ub;
 557
 558         blob_buf_init(&b, 0);
 559         blob_put_int32(&b, UBUS_ATTR_OBJID, s->subscriber->id.id);
 560         blob_put_int32(&b, UBUS_ATTR_TARGET, s->target->id.id);
 561
 562         ub = ubus_msg_from_blob(false);
 563         if (ub != NULL) {
 564                 ubus_msg_init(ub, UBUS_MSG_UNSUBSCRIBE, ++s->subscriber->invoke_seq, 0);
 565                 ubus_msg_send(s->subscriber->client, ub);
 566                 ubus_msg_free(ub);
 567         }
 568
 569         ubus_unsubscribe(s);
 570 }
 571
 572 static void __constructor ubusd_proto_init(void)
 573 {
 574         ubus_init_id_tree(&clients);
 575 }